2008 September 30 Tuesday
Antisocial Kids Have Less Cortisol In Stressful Situations

The juvenile delinquent kids going down the wrong path maybe act bad due to endocrine system deficiencies in cortisol production.

A link between reduced levels of the 'stress hormone' cortisol and antisocial behaviour in male adolescents has been discovered by a research team at the University of Cambridge.

Levels of cortisol in the body usually increase when people undergo a stressful experience, such as public speaking, sitting an exam, or having surgery. It enhances memory formation and is thought to make people behave more cautiously and to help them regulate their emotions, particularly their temper and violent impulses.

So suppose we could come up with a nanosensor that measured when some violent guy was about to act aggressively. Imagine combining that with some nanocomputer and a little nanotube network tied to some cells that can be stimulated to excrete cortisol. Implant all that into the body of someone with violent impulses and it should be possible to cut back on their violent outbursts. What do you think? Want safer streets via tech that controls people? We are maybe about 10 years away from being able to do this sort of thing.

I'd like to know which sorts of antisocial kids don't produce as much cortisol. Do some of them lack the ability to see a situation as stressful?

The new research, funded by the Wellcome Trust, shows that adolescents with severe antisocial behaviour do not exhibit the same increase in cortisol levels when under stress as those without antisocial behaviour. These findings suggest that antisocial behaviour, at least in some cases, may be seen as a form of mental illness that is linked to physiological symptoms (involving a chemical imbalance of cortisol in the brain and body).

The scientists, led by Dr Graeme Fairchild and Professor Ian Goodyer, recruited participants for the study from schools, pupil referral units, and the Youth Offending Service. Samples of saliva were collected over several days from the subjects in a non-stressful environment to measure levels of the hormone under resting conditions. The young men then took part in a stressful experiment that was designed to induce frustration. Samples of saliva were taken immediately before, during and after the experiment to track how cortisol changed during stress.

The differences between participants with severe antisocial behaviour and those without were most marked under stressful conditions. While the average adolescents showed large increases in the amount of cortisol during the frustrating situation, cortisol levels actually went down in those with severe antisocial behaviour.

So are these kids this way because of genetic reasons, responses to experiences, or some combination thereof? Maybe the bad kids have become desensitized to stress? Or maybe their ability to get violent in stressful situation was an adaptive advantage for their ancestors and contributing genes got selected for.

Some kids go bad with depressed cortisol levels at age 5. Pity the parents - unless they too have depressed cortisol levels and are terrors.

One other surprise was that the cortisol drops were about the same across all the delinquents, whether they originally became disruptive during childhood or during adolescence.

Although it's already accepted that there is a strong biological component to "early-onset" conduct disorder, which develops around the age of five, the current thinking is that when delinquency develops in teenagers, it's mainly a result of malevolent peer pressure, perhaps combined with lack of supervision at home.

The new research challenges this picture by showing that in both groups, cortisol levels fell – a biological rather than peer-led response.

Implanted devices that release cortisol would be like an artificial endocrine system that makes up for underactive adrenal glands.

By Randall Parker 2008 September 30 11:15 PM  Brain Violence
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2008 September 29 Monday
Low Cost Atmospheric Carbon Dioxide Removal Looks Possible

If carbon dioxide build-up starts causing unacceptable climate change then a cheap way to remove CO2 from the atmosphere might become an option.

University of Calgary climate change scientist David Keith and his team are working to efficiently capture the greenhouse gas carbon dioxide directly from the air, using near-commercial technology.

In research conducted at the U of C, Keith and a team of researchers showed it is possible to reduce carbon dioxide (CO2) – the main greenhouse gas that contributes to global warming – using a relatively simple machine that can capture the trace amount of CO2 present in the air at any place on the planet.

...Keith and his team showed they could capture CO2 directly from the air with less than 100 kilowatt-hours of electricity per tonne of carbon dioxide. Their custom-built tower was able to capture the equivalent of about 20 tonnes per year of CO2 on a single square metre of scrubbing material – the average amount of emissions that one person produces each year in the North American-wide economy.

That 100 kwh per removed tonne of CO2 would be pretty good in terms of energy cost. If the electricity cost only 10 cents per kwh then the cost per tonne would be only $10. Some proposed carbon tax regimes are at $30 per tonne and up. This could be done with photovoltaics once PV becomes cheap enough. The fact that the sun doesn't shine all the time won't matter. Just run the process when the power is available. No need for transmission lines or even expensive circuitry to convert the electricity into AC power. Though materials costs and piping the CO2 somewhere might add substantial costs.

"This means that if you used electricity from a coal-fired power plant, for every unit of electricity you used to operate the capture machine, you'd be capturing 10 times as much CO2 as the power plant emitted making that much electricity," Keith says.

The U of C team has devised a new way to apply a chemical process derived from the pulp and paper industry cut the energy cost of air capture in half, and has filed two provisional patents on their end-to-end air capture system.

The technology is still in its early stage, Keith stresses. "It now looks like we could capture CO2 from the air with an energy demand comparable to that needed for CO2 capture from conventional power plants, although costs will certainly be higher and there are many pitfalls along the path to commercialization."

What I'd like to see: Use sunlight to drive an artificial photosynthesis process that will fix hydrogen from water to CO2 from the atmosphere. The output would be hydrocarbons usable to power cars and for other purposes. All this will come with time.

Update: See the comment by Bruce Dunn. Looks like the energy for the initial CO2 capture is a small fraction of the total amount of energy needed for this method. So this looks like a bad idea.

By Randall Parker 2008 September 29 10:36 PM  Energy Solar
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No Joint Benefit From Glucosamine Or Chondroitin

If glucosamine and chondroitin provide any relief from osteoarthritis 572 study participants weren't enough to prove it.

The dietary supplements glucosamine and chondroitin sulfate, together or alone, appeared to fare no better than placebo in slowing loss of cartilage in osteoarthritis of the knee, researchers from the Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) team report in the October issue of Arthritis & Rheumatism.[1] Interpreting the study results is complicated, however, because participants taking placebo had a smaller loss of cartilage, or joint space width, than predicted. Loss of cartilage, the slippery material that cushions the joints, is a hallmark of osteoarthritis and its loss is typically measured as a reduction in joint space width—the distance between the ends of bones in a joint as seen on an X-ray.

Rather than slowing down the decay we really need ways to stop and reverse it. Some sort of stem cell therapy is the best bet. Gene therapy might end up helping but I expect benefits from stem cells sooner. Further out nanobots will do joint repair. I hope at least one of these becomes available before any of my joints start to ache.

Glucosamine might provide a small benefit. But if glucosamine does provide a benefit it is not so large that it shouts out.

Rheumatologist Allen D. Sawitzke, M.D., associate professor of internal medicine at the University of Utah School of Medicine, was lead investigator. "At two years, no treatment achieved what was predefined to be a clinically important reduction in joint space width loss," Sawitzke said. "While we found a trend toward improvement among those with moderate osteoarthritis of the knee in those taking glucosamine, we were not able to draw any definitive conclusions."

A whole lot of people suffer pain from osteoarthritis. How many do you know that live with constant osteoarthritic pain?

More than 21 million Americans have osteoarthritis, with many taking glucosamine and chondroitin sulfate, separately or in combination, to relieve pain.

By Randall Parker 2008 September 29 10:05 PM  Aging Diet Bone Studies
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Higher Testosterone Men Greater Financial Risk Takers

In the future will genetically engineered male offspring have higher testosterone and greater risk taking tendencies? Will we see more financial disasters as a result but also a higher rate of innovation? Higher testosterone correlates with more risk taking behavior with money.

CAMBRIDGE, Mass., September 29, 2008 – Higher levels of testosterone are correlated with financial risk-taking behavior, according to a new study in which men's testosterone levels were assessed before participation in an investment game. The findings help to shed light on the evolutionary function and biological origins of risk taking.

The study was jointly led by Anna Dreber, of the Program in Evolutionary Dynamics at Harvard University and the Stockholm School of Economics, and Coren Apicella, of Harvard's Department of Anthropology. The results are available online in Evolution and Human Behavior.

This is an unsurprising result for anyone who doesn't buy the idea that environment programs all of our sexual differences in behavior.

These were Harvard students. What I'd like to know: How do testosterone levels vary as a function of degree of exclusivity of a college? Does State U have lower or higher testosterone guys than Harvard or Yale? Also, do MIT and CalTech have lower or higher testosterone males than the Ivy League? What about the females? I'm betting female English students have lower testosterone than female engineering students.

In the study, saliva samples were taken from 98 males, ages 18 to 23, who were mostly Harvard students. The samples were taken before participation in the investment game, so the researchers were certain that testosterone levels were not elevated as a result of the game. The researchers also assessed facial masculinity, associated with testosterone levels at puberty.

All of the participants were given $250, and were asked to choose an amount between $0 and $250 to invest. The participants kept the money that was not invested. A coin toss determined the investment's outcome, and if the participant lost the coin toss, the money allocated to the investment was lost. However, if the coin toss was won, the participant would receive two and a half times the amount of their investment. At the end of the study, one person was selected by lottery to receive the cash amount of their investment, which created a monetary incentive for the participants.

The researchers found that a man whose testosterone levels were more than one standard deviation above the mean invested 12 percent more than the average man into the risky investment. A man with a facial masculinity score of one standard deviation higher than the mean invested 6 percent more than the average man.

Do investment bankers and hedge fund operators have higher testosterone than commercial bank executives? Do the former CEOs of failed banks have higher or lower testosterone than CEOs of successful banks?

Men take risks in order to raise their wealth and appeal in the eyes of women.

"Financial risk might be comparable to other risky male behaviors associated with reproduction," says Apicella. "Men may be more willing to take financial risks because the payoffs, in terms of attracting mates, could be higher for them. This is because women value wealth more than men when choosing for a mate."

So then if men cause financial disasters women made them do it.

Here is the abstract. You can find the full article at that link. Note the 2D:4D probably refers to fingers whose lengths differ based on fetal testosterone exposure.

Many human behaviors, from mating to food acquisition and aggressiveness, entail some degree of risk. Testosterone, a steroid hormone, has been implicated in a wide range of such behaviors in men. However, little is known about the specific relationship between testosterone and risk preferences. In this article, we explore the relationship between prenatal and pubertal testosterone exposure, current testosterone, and financial risk preferences in men. Using a sample of 98 men, we find that risk-taking in an investment game with potential for real monetary payoffs correlates positively with salivary testosterone levels and facial masculinity, with the latter being a proxy of pubertal hormone exposure. 2D:4D, which has been proposed as a proxy for prenatal hormone exposure, did not correlate significantly with risk preferences. Although this is a study of association, the results may shed light on biological determinants of risk preferences.

By Randall Parker 2008 September 29 01:36 PM  Brain Economics
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2008 September 28 Sunday
US Car Companies Commit To Pluggable Hybrids

Tony Posawatz, Chevrolet's vehicle line director for the Volt, sounds optimistic on the Chevy Volt hitting the market in 2010.

"We definitely feel that we're on schedule, that we will be able to deliver the Volt before the end of 2010," Posawatz said. "We're working closely with our battery developers, and based on their progress, we're definitely on track to hit that 2010 date."

Eighteen months ago, many in the industry thought that the internally-mandated 2010 date was just too much to expect, given all of the technology and cost implications.

"Well, it is definitely a compressed time frame," Posawatz conceded. "It is unusual to develop a new vehicle and a new propulsion system at the same time. But the analogy that Mr. Lutz used was when he compared it to President Kennedy saying that we were going to send a man to the moon by the end of the decade, not 'whenever we feel like it.'

GM is not alone among the US automakers in terms of a PHEV commitment. Though GM sounds like they are in the lead.Chrysler expects to get one of four electric vehicles to market by 2010.

Chrysler showed four new electric vehicles: two extended-range electric vehicles that have gas-fed generators to feed electricity to the car when a 40-mile-range battery wears down; an all-electric sports car with a range of 150-200 miles; and a four-door neighborhood-electric-vehicle, which can be used in retirement and closed communities and on streets with speed limits of 25 mph or less.

Most likely the first will probably be a sports car that competes with the Tesla. Chrysler has recently released a couple of full-sized hybrid SUVs.

Ford has committed to a plug-in (PHEV) version of their Escape hybrid. Given the coming Fusion Hybrid on the same drivetrain as the Escape Hybrid it seems reasonable to expect a PHEV Fusion as well. Ford hasn't committed to a date yet. Ford sees pure electric vehicles as the ultimate destination.

By Randall Parker 2008 September 28 11:05 PM  Energy Electric Cars
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Mediterranean Diet Dying Out In Mediterranean

Why have Americans been more overweight than other Westerners? We were ahead of them in a trend. Europeans are porking out. This porking trend has extended down into the part of Europe which has been celebrated for the success of its diet: the Mediterranean. Greeks, Italians, and Spaniards are abandoning the Mediterranean diet with unhealthful consequences.

Small towns like this one in western Crete, considered the birthplace of the famously healthful Mediterranean diet — emphasizing olive oil, fresh produce and fish — are now overflowing with chocolate shops, pizza places, ice cream parlors, soda machines and fast-food joints.

The fact is that the Mediterranean diet, which has been associated with longer life spans and lower rates of heart disease and cancer, is in retreat in its home region. Today it is more likely to be found in the upscale restaurants of London and New York than among the young generation in places like Greece, where two-thirds of children are now overweight and the health effects are mounting, health officials say.

We are not designed to handle the fast food diet. Better that the Greeks return to their traditional dishes. Greece now has the worst obesity rate in Europe. Wow.

This spring, a majority of children who were tested at the elementary school of this sleepy port town of 3,000, also known as Kissamos, were found to have high cholesterol. “It was the talk of the school,” said Stella Kazazakou, 44. “Instead of grades, the moms were comparing cholesterol levels.”

In Greece, three-quarters of the adult population is overweight or obese, the worst rate in Europe “by far,” according to the United Nations. The rates of overweight 12-year-old boys rose more than 200 percent from 1982 to 2002 and have been rising even faster since.

Italy and Spain are not far behind, with more than 50 percent of adults overweight. That compares with about 45 percent in France and the Netherlands.

Fresh produce and olive oil can't compete with hamburgers and fries. We need to either genetically engineer ourselves to dislike junk food or we need to genetically engineer our metabolisms to handle junk food without harmful effects.

By Randall Parker 2008 September 28 07:36 PM  Aging Diet Studies
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Blood Vessel Stem Cell Source Found

Pericytes can become blood vessels, bone, muscles, and cartilage.

In a promising finding for the field of regenerative medicine, stem cell researchers at Children's Hospital of Pittsburgh of UPMC have identified a source of adult stem cells found on the walls of blood vessels with the unlimited potential to differentiate into human tissues such as bone, cartilage and muscle.

The scientists, led by Bruno Péault, PhD, deputy director of the Stem Cell Research Center at Children's Hospital, identified cells known as pericytes that are multipotent, meaning they have broad developmental potential. Pericytes are found on the walls of small blood vessels such as capillaries and microvessels throughout the body and have the potential to be extracted and grown into many types of tissues, according to the study.

Sources of adult stem cells have obvious applications for the creation of therapies. But a discovery such as this one has other benefits which are less immediately obvious. Notably, we need to know all the cell types in our bodies and their distribution and function in order to know all the cell types we need to target with rejuvenation therapies. Obviously, if a discovery such as this one is possible to make in 2008 we do not know all the cell types we have or all the places these cell types are found.

The ability to isolate all the stem cells and progenitor cells from human bodies makes it easier to study key cell types to measure how much they've aged. For example, we need to know whether stem cell aging plays a big role in artery clogging with atherosclerotic plaques. If we could grow large numbers of youthful pericytes outside of the body would injecting these cells into the body cut the risks of stroke and heart attack? Or are the existing pericytes getting suppressed by chemicals that build up in the blood as we age?

Since pericytes are found in so many tissue types they will be easy to extract.

"This finding marks the first direct evidence of the source of multipotent adult stem cells known as mesenchymal stem cells. We believe pericytes represent one of the most promising sources of multipotent stem cells that scientists have been searching for in the quest to make regenerative medicine possible," Dr. Péault said. "The encouraging aspect of this source is that blood vessels are the one structure that all tissues in the human body have in common. These cells can be extracted easily and painlessly from convenient sources such as fat tissue, dental pulp, umbilical cord and placental tissue, then grown in culture to large numbers and, possibly, re-injected into the patient to heal a broken bone, a failing joint or an injured muscle."

Results of the study are published in the September issue of the journal Cell Stem Cell.

Could pericytes or cells grown from pericytes be injected into joints to repair worn cartilage? We are all wearing out. Many of us will some day start feeling pains from cartilage wearing (and some of you already feel such pains). So the ability to manipulate pericytes to get them to do our bidding will probably some day help us avoid a lot of suffering.

Update: Some Stanford researchers also just discovered a muscle stem cell that exists among muscle satellite cells.

A single cell can repopulate damaged skeletal muscle in mice, say medical school scientists who devised a way to track the cell's fate in living animals. The research is the first to confirm that the so-called satellite cells, which encircle muscle fibers, harbor an elusive muscle stem cell.

Identifying and isolating such a cell in humans would have therapeutic implications for disorders such as muscular dystrophy, muscle injury and muscle wasting due to aging, disuse or disease.

"We were able to show at the single-cell level that these cells are true, multipotent stem cells," said Helen Blau, PhD, the Donald E. and Delia B. Baxter Professor of Pharmacology. "They fit the classic definition: they can both self-renew and give rise to specialized progeny." Blau is the senior author of the study, published Sept. 17 in the online issue of Nature.

Alessandra Sacco, PhD, senior research scientist in Blau's laboratory and the article's first author, added, "It's been known that these satellite cells are crucial for the regeneration of muscle tissue, but this is the first demonstration of self-renewal of a single cell."

The transplanted individual cells went on to replicate into thousands and even tens of thousands of cells. But these researchers were not able to tell which satellite cells are really stem cells. So they have more work to do in order to know when a particular cell is really a stem cell.

I am especially interested to learn whether these stem cells, satellite cells, and other progenitor cells show signs of serious aging. Or do muscles, blood vessels, and other tissue decay because the signaling gets lost or muffled that should tell the stem cells to produce replacement repair cells?

By Randall Parker 2008 September 28 01:43 PM  Biotech Stem Cells
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2008 September 26 Friday
Only Low Doses Of Chocolate Reduce Inflammation Marker

Less than a full candy bar of dark chocolate appears to be the ideal dose for inflammation reduction.

Maybe gourmands are not jumping for joy. Probably they would have preferred bigger amounts to sup-port their passion. Though the news is still good for them: 6.7 grams of chocolate per day represent the ideal amount for a protective effect against inflammation and subsequent cardiovascular disease. A new effect, demonstrated for the first time in a population study by the Research Laboratories of the Catholic University in Campobasso, in collaboration with the National Cancer Institute of Milan.

That 6.7 grams per day is only 47 grams per week or about 1.7 ounces. We aren't even talking a full candy bar.

The scientists looked for benefits from chocolate by measuring the level of inflammation by checking C-reactive protein (CRP) in the blood. Whether lowering CRP with chocolate really will provide a long term health benefit remains unproven.

"We started from the hypothesis", says Romina di Giuseppe, 33, lead author of the study, "that high amounts of antioxidants contained in the cocoa seeds, in particular flavonoids and other kinds of polyphenols, might have beneficial effects on the inflammatory state. Our results have been absolutely encouraging: people having moderate amounts of dark chocolate regularly have significantly lower levels of C-reactive protein in their blood. In other words, their inflammatory state is considerably reduced." The 17% average reduction observed may appear quite small, but it is enough to decrease the risk of cardiovascular disease for one third in women and one fourth in men." It is undoubtedly a remarkable outcome".

Chocolate amounts are critical. "We are talking of a moderate consumption. The best effect is obtained by consuming an average amount of 6.7 grams of chocolate per day, corresponding to a small square of chocolate twice or three times a week. Beyond these amounts the beneficial effect tends to disappear".

The researchers didn't bother studying the effects of milk chocolate since they expected the milk to interference with absorption of polyphenols.

From a practical point of view, as the common chocolate bar is 100 grams, the study states that less than half a bar of dark chocolate consumed during the week may become a healthy habit. What about the milk chocolate? "Previous studies", the young investigator continues, "have demonstrated that milk interferes with the absorption of polyphenols. That is why our study considered just the dark chocolate".

I wonder whether interference with polyphenol absorption is one of the reasons why some studies find harmful effects from milk products consumption.

From the paper's abstract: If you ate about 3/4ths of an ounce of dark chocolate every third day you'd get the optimal benefit.

A J-shaped relationship between dark chocolate consumption and serum CRP was observed; consumers of up to 1 serving (20 g) of dark chocolate every 3 d had serum CRP concentrations that were significantly lower than nonconsumers or higher consumers. Our findings suggest that regular consumption of small doses of dark chocolate may reduce inflammation.

So perhaps eat small amounts of dark chocolate a couple of times a week. But why do higher doses of dark chocolate fail to provide a benefit? Is it really the size of the dose or the frequency of the dose that makes consumption of larger amounts of chocolate fail to lower CRP? Maybe more frequent consumption of dark chocolate up-regulates enzymes that break down polyphenols.

By Randall Parker 2008 September 26 11:46 PM  Aging Diet Heart Studies
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Pistachios Improve Blood Cholesterol

Pistachios are good for your heart and arteries.

The participants began the study by eating a typical American diet consisting of 35 percent total fat and 11 percent saturated fat for two weeks. They then tested three diets for four weeks each with about a two-week break between each diet. All three diets were variations on the Step I Diet, a cholesterol-lowering diet in general use. The diets included, as a control, a Step I Diet with no pistachios and about 25 percent total fat and 8 percent saturated fat. The pistachio enhanced diets were Step I Diets with 10 and 20 percent of the energy supplied by pistachio nuts, respectively. The 10 percent pistachio diet had 30 percent total fat and 8 percent saturated fat and the 20 percent pistachio diet had 34 percent total fat and 8 percent saturated fat.

The pistachios change cholesterol metabolism.

The participants ate half their pistachios as a snack and the rest incorporated into meals.

The researchers report in the most recent issue of the American Journal of Clinical Nutrition that "Inclusion of pistachios in a healthy diet beneficially affects cardiovascular disease risk factors in a dose-dependent manner, which may reflect effects on Stearoyl CoA Desaturase (SCD). " The researchers used the ratio of two fatty acids, 16:1 and 16:0 in plasma as a marker for SCD, an enzyme that is involved in the body's synthesis of fatty acids.

"SCD is an important enzyme involved in cholesterol metabolism," says Gebauer.

They found the ratio of 16:1/16:0 was significantly lower, suggesting a decrease in SCD activity, after eating the 20 percent energy pistachio diet compared to the control diet which had no pistachios. Also, the change in the 16:1/16:0 ratio was correlated with the change in cholesterol, suggesting that SCD activity may contribute to the lipid-lowering effects of pistachios. That, accompanied by the dose-dependent effects of the pistachios, begins to unravel the way in which pistachios improve cardiovascular health.

So pistachios contain some to-be-discovered compound(s) that help improve your blood lipids. Foods are pharmaceuticals, mostly by accident.

Note that the pistachio fats did not displace the other fats in the diet. They added to total dietary fat but in a way that improved blood lipids.

Compared to the control diet, the 20 percent pistachio diet lowered LDL cholesterol -- bad cholesterol -- about 12 percent and the 10 percent energy pistachio diet lowered LDL cholesterol by 9 percent that suggests a 9 to 12 percent decrease in coronary heart disease risk. The relationships of total cholesterol to HDL cholesterol and LDL cholesterol to HDL cholesterol may be more powerful predictors of cardiovascular risk. The effects of the 10 and 20 percent energy diets showed a dose dependent effect on these ratios.

Phytosterols in pistachios might be behind the protective effect.

However, the researchers note that the reduction in LDL cholesterol observed was seven times greater than would be expected from only the fatty acid profile of pistachios. They suggest that the lipid lowering effects not only reflect the fatty acid profile of the diet, but also are the result of other bioactive substances in pistachios, perhaps phytosterols and fiber.

I'd like to see this experiment repeated with other kinds of nuts to see the relative potencies of different nuts.

By Randall Parker 2008 September 26 11:05 PM  Aging Diet Heart Studies
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2008 September 25 Thursday
Adult Cell To Stem Cell Conversion Made Safer

Harvard researchers have improved a technique for converting adult cells into induced pluripotent stem (iPS) cells. Pluripotent stem cells can become all other cell types in the body.

Now researchers led by Konrad Hochedlinger of the Massachusetts General Hospital, Boston, have used the same four genes to create iPS cells, but carried instead by adenoviruses. These don't normally integrate into the genome of cells that they infect and therefore present little risk of cancer.

Many gene therapy techniques boost the risk of cancer. The initial method used to introduce genes to reprogram adult cells into stem cells ran the risk of creating cancerous cells. This newer technique lowers that risk substantially.

This method for creating pluripotent stem cells has a few advantages over using embryos. Most obviously, the political ethical opposition to human embryo destruction is avoided. Second, the stem cells can be produced from one's own body and so they are more likely to be immunologically compatible. Third, the cost might go lower.

This improvement in technique comes less than a year after the original paper that showed how to change adult cells into iPS cells.

"This is certainly a major stem cell milestone," said Advanced Cell Technologies chief scientific officer Bob Lanza, who was not involved in the research. "It’s the first ray of light that iPS cells could soon be used to treat patients."

These iPS cells -- short for induced pluripotent stem cell -- debuted less than a year ago: By using viruses to insert key developmental genes, researchers coaxed human skin cells into an embryonic state, capable of growing into almost any other type of tissue.

This moves us a lot closer toward having useful stem cell therapies. We need those therapies in order to reverse the aging process and rejuvenate our bodies.

By Randall Parker 2008 September 25 11:49 PM  Biotech Stem Cells
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8 Year Olds Learn Little From Negative Feedback

By age of 12 children show adult patterns of brain response to negative feedback.

Eight-year-old children have a radically different learning strategy from twelve-year-olds and adults. Eight-year-olds learn primarily from positive feedback ('Well done!'), whereas negative feedback ('Got it wrong this time') scarcely causes any alarm bells to ring. Twelve-year-olds are better able to process negative feedback, and use it to learn from their mistakes. Adults do the same, but more efficiently.

The switch in learning strategy has been demonstrated in behavioural research, which shows that eight-year-olds respond disproportionately inaccurately to negative feedback. But the switch can also be seen in the brain, as developmental psychologist Dr Eveline Crone and her colleagues from the Leiden Brain and Cognition Lab discovered using fMRI research. The difference can be observed particularly in the areas of the brain responsible for cognitive control. These areas are located in the cerebral cortex.

In children of eight and nine, these areas of the brain react strongly to positive feedback and scarcely respond at all to negative feedback. But in children of 12 and 13, and also in adults, the opposite is the case. Their 'control centres' in the brain are more strongly activated by negative feedback and much less by positive feedback.

What I wonder: Do some people fail to make the transition toward reacting more to negative feedback? Are some adults neurologically not wired up to learn from negative feedback? Likely the extent of the shift differs from person to person as they grow up and the timing of the shift differs as well.

By Randall Parker 2008 September 25 11:20 PM  Brain Development
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Calorie Restriction Not As Life Extending As In Mice?

A scientist at Washington University in St. Louis worked with Calorie Restriction Society members (known as CRONies - Calorie Restriction with Optimal Nutrition) to see whether calorie restriction (CR) would extend life as well in humans as it does in rats and mice. Well, among the CRONies calorie restriction did not lower the level of a growth factor called IGF-1 as well as CR does in mice. This suggests that human calorie restriction might not extend life as much as it does in mice.

St. Louis, Sept. 24, 2008 — Calorie restriction, a diet that is low in calories and high in nutrition, may not be as effective at extending life in people as it is in rodents, according to scientists at Washington University School of Medicine in St. Louis.

Previous research had shown that laboratory animals given 30 percent to 50 percent less food can live up to 50 percent longer. Because of those findings, some people have adopted calorie restriction in the hope that they can lengthen their lives. But the new research suggests the diet may not have the desired effect unless people on calorie restriction also pay attention to their protein intake.

Biogerontology theorist Aubrey de Grey already does not expect CR to extend human life by double digit percentages like it does in rodents. Aubrey argues that CR might extend human life by a year or two as a way to help people live longer to reproduce after a couple of bad growing seasons. The selective pressure on humans about how their metabolism should respond to CR probably didn't produce a capacity for human metabolism to reduce the rate of aging by such a large amount. Besides, we already have many life-extending mutations that mice do not have as we live much longer than they do.

In an article published online this month in the journal Aging Cell, investigators point to a discrepancy between humans and animals on calorie restriction. In the majority of the animal models of longevity, extended lifespan involves pathways related to a growth factor called IGF-1 (insulin-like growth factor-1), which is produced primarily in the liver. Production is stimulated by growth hormone and can be reduced by fasting or by insensitivity to growth hormone. In calorie-restricted animals, levels of circulating IGF-1 decline between 30 percent and 40 percent.

"We looked at IGF-1 in humans doing calorie restriction," says first author Luigi Fontana, M.D., Ph.D., assistant professor of medicine at Washington University and an investigator at the Istituto Superiore di Sanità in Rome, Italy. "For years, we have been following a cohort of people from the CR Society who have been on long-term calorie restriction. We found no difference in IGF-1 levels between people on calorie restriction and those who are not."

Fontana decided that since vegans have much lower IGF-1 levels that perhaps lowering protein intake in CRONies would work to lower IGF-1. Well, yes, it did. So here's the bottom line: maybe reducing protein consumption will allow us to live longer.

Again, Fontana had a ready-made study group. His team has been following a population of strict vegans for several years. They tend to eat less protein than the CRONies from the CR Society, so he compared IGF-1 levels between the two groups.

"The vegans had significantly less circulating IGF-1, even if they were heavier and had more body fat than CRONies," he says. "Protein in the diet seemed to correlate with the lower levels of IGF-1. The strict vegans took in about 10 percent of their total calories from protein, whereas those on calorie restriction tended to get about 23 or 24 percent of calories from protein."

The investigators wanted to take one more look at the relationship between dietary protein and IGF-1, so Fontana asked a group of CRONies to eat less protein for a few weeks. He says it was not easy to cut protein because those on calorie restriction have to do a lot of calculating and juggling to ensure they take in very few calories and still get adequate nutrition. Increasing dietary protein is one way many CRONies guard against becoming malnourished.

"But six of them agreed to lower their protein intake," Fontana explains, "and after three weeks their circulating IGF-1 declined dramatically."

Cutting back on your protein consumption is easier than cutting back on your calories.

By Randall Parker 2008 September 25 12:13 AM  Aging Diet Studies
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2008 September 23 Tuesday
Cheaper Method Achieves High Efficiency Solar Cells

Move over cheap but lower efficiency thin film photovoltaic cells. A company called Suniva claims a cheaper way to make photovoltaic cells with high conversion efficiency.

A cheap new way to attach mirrors to silicon yields very efficient solar cells that don't cost much to manufacture. The technique could lead to solar panels that produce electricity for the average price of electricity in the United States.

Suniva, a startup based in Atlanta, has made solar cells that convert about 20 percent of the energy in the sunlight that falls on them into electricity. That's up from 17 percent for its previous solar cells and close to the efficiency of the best solar cells on the market. But unlike other high-efficiency silicon solar cells, says Ajeet Rohatgi, the company's founder and chief technology officer, Suniva's are made using low-cost methods. One such method is screen printing, a relatively cheap process much like the silk-screen process used to print T-shirts.

The company thinks it can achieve a further cost reduction by using thinner wafers while still maintaining a high conversion efficiency. But that goal lies in the future. If they can achieve it then they expect their solar cells to become competitive with some of the much cheaper existing non-solar ways to generate electricity.

By Randall Parker 2008 September 23 11:31 PM  Energy Solar
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Lower Cost Catalyst Converts Cellulose To Ethylene Glycol

For biomass energy technology I watch two areas: algae biodiesel and cellulosic technology. The latter is of interest because it makes trees and other non-food plant matter useful as an energy source. Some researchers in China and Delaware have developed a catalyst that converts cellulose into ethylene glycol.

Alternatives to fossil fuels and natural gas as carbon sources and fuel are in demand. Biomass could play a more significant part in the future. Researchers in the USA and China have now developed a new catalyst that directly converts cellulose, the most common form of biomass, into ethylene glycol, an important intermediate product for chemical industry. As reported in the journal Angewandte Chemie, the catalyst is made of tungsten carbide and nickel on a carbon support.

You might think that producing ethylene glycol doesn't help much to power an engine. True enough. But oil gets used for many chemical feedstock purposes. A method of replacing oil for the chemical industry will free up more oil for powering transportation. Plus, car radiators contain ethylene glycol.

A team led by Tao Zhang at the Dalian Institute of Chemical Physics (China) and Jingguang G. Chen at the University of Delaware (Newark, USA) has now developed just such a system. The catalyst is made of tungsten carbide deposited on a carbon support. Small amounts of nickel improve the efficiency and selectivity of the catalyst system: a synergetic effect between the nickel and tungsten carbide not only allows 100 % conversion of cellulose, but also increases the proportion of ethylene glycol in the resulting mixture of polyalcohols to an amazing 61 %. Ethylene glycol is an important intermediate in the chemical industry. For example, in the plastics industry it is needed for the production of polyester fibers and resins, and in the automobile industry it is used as antifreeze.

I'm still reserving my biggest biomass energy hope for advances in growing algae to produce liquid hydrocarbons burnable in vehicles. Will genetic engineering be required to make algae more useful?

Update: Technology Review reports that another research group claims a newer and cheaper process for converting biomass into useful chemical energy.

Researchers at the University of Wisconsin-Madison have developed a simple, two-step chemical process to convert plant sugars into hydrocarbon fuels. The compounds created during the process could also be used to make other industrial chemicals and plastics.

...

The Wisconsin researchers, led by chemical- and biological-engineering professor James Dumesic, employ chemical reactions instead of microbial fermentation. They use catalysts at high temperatures to convert glucose into hydrocarbon biofuels. The process works thousands of times faster than microbes do because of the higher temperatures, so it requires smaller, cheaper reactors, Dumesic says.

We are in a race between the approaching global decline in oil production and technological advances to provide us with substitutes. The longer we can go before the oil production decline starts the more technology we will have to help us adjust to it. It is still not clear to me how disruptive this decline will be.

By Randall Parker 2008 September 23 10:58 PM  Energy Biomass
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Aged Brain Has Less Capacity To Feel Rewards?

A paper published in the US Proceedings of the National Academy of Sciences finds that reduced dopamine metabolism in the brain suggests that as we age we experience a reduced capacity to feel rewarded.

Here, by using 6-[18F]FluoroDOPA (FDOPA) positron emission tomography (PET) and event-related 3T functional magnetic resonance imaging (fMRI) in the same subjects, we directly demonstrate a link between midbrain dopamine synthesis and reward-related prefrontal activity in humans, show that healthy aging induces functional alterations in the reward system, and identify an age-related change in the direction of the relationship (from a positive to a negative correlation) between midbrain dopamine synthesis and prefrontal activity. These results indicate an age-dependent dopaminergic tuning mechanism for cortical reward processing and provide system-level information about alteration of a key neural circuit in healthy aging. Taken together, our findings provide an important characterization of the interactions between midbrain dopamine function and the reward system in healthy young humans and older subjects, and identify the changes in this regulatory circuit that accompany aging.

This seems like a big loss to me. We need stem cell therapies, gene therapies, and nanobot therapies that can go into our brains and repair the accumulated damage and restore youthful function.

By Randall Parker 2008 September 23 12:06 AM  Brain Aging
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2008 September 22 Monday
Drug Prevents Vascular Plaques In Pigs

When it isn't the mice getting all the hot new drug treatments before humans do it is the pigs that get the latest that science has to offer. A drug blocks formation of atherosclerotic plaques.

PHILADELPHIA – Using the drug darapladib, researchers at the University of Pennsylvania School of Medicine and colleagues have inhibited a cholesterol-and immune system-associated protein, thereby reducing the development of heart-disease plaques that may cause death, heart attacks, and strokes in a pig model of atherosclerosis and diabetes. The study appeared online this week in Nature Medicine.

Though to be fair the drug was recently tested in human trials in Europe. So the message here is that European humans and American pigs rank above American humans in getting the new drugs. We can't eat the Europeans but we can certainly get even with the pigs by eating ham. Though the ham will probably cause clogged arteries. No wonder the pigs are hogging this drug for themselves. They obviously want us to die and leave them alone.

This drug blocks an enzyme which is involved with LDL cholesterol.

A molecule called lipoprotein-associated phospholipase A2 (Lp-PLA2) is connected with LDLs circulating in the blood. Elevated levels of Lp-PLA2 in the blood predict an increased risk of heart disease events and are related to the development of the necrotic core of plaques. Darapladib specifically inhibits Lp-PLA2.

“The results are exciting,” says Wilensky. “First, darapladib reduced the overall amount and size of plaques that block the coronary arteries of animals in the study. More importantly, it reduced the number and size of the type of advanced plaques that cause heart attacks and strokes. “

Artery clogging looks set to become preventable years before we can cure cancer.

By Randall Parker 2008 September 22 11:46 PM  Aging Cardiovascular Studies
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Aging Vascular System Increases Weight Gain?

Endothelial cells in blood vessels prevent stem cells from becoming fat cells.

INDIANAPOLIS — The cells lining blood vessels are known to be important for maintaining health, but researchers at the Indiana University School of Medicine believe these cells may perform an unsuspected task – controlling the development of fat cells. Their findings are reported in the September issue of the journal Stem Cells.

The researchers found that precursor or stem cells have a markedly reduced tendency to develop into fat cells when placed in direct contact with healthy endothelial cells, which are the cells that line blood vessels.

"The key to this discovery was our recent observation that these cells, also known as adipose stromal cells, in fat tissue are in very close contact with endothelial cells in small blood vessels and capillaries," said Keith L. March, M.D., Ph.D., co-principal investigator of the study and director of the Indiana Center for Vascular Biology and Medicine (ICVBM).

Maybe (this is just a hypothesis) aging blood vessel endothelial cells cease to tell stem cells to not become fat cells. Then more fat cells get made and we become fatter.

"What we don't know yet is how the formation of fat cells influences the blood vessel lining cells. Our current hypothesis is that endothelial dysfunction promotes fat cell development, accompanied by new blood vessel growth. We hope to soon be able to interrupt this cycle," said Dr. Clauss.

So maybe stem cell therapies that we already need to reverse vascular aging will also reduce the amount of obesity in older people? The body is an elaborate machine with very complex interconnections between all its parts. When some parts start to fail their decay can cause many different side effects aside from the most obvious. So an aging vascular system could not just increase the risk of stroke and heart attack and not just lower athletic performance. It could cause many other less obvious and harmful changes.

By Randall Parker 2008 September 22 11:01 PM  Aging Cardiovascular Studies
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Traditionalist Men Make More Money

Old fashioned guys bring home more cash.

WASHINGTON – When it comes to sex roles in society, what you think may affect what you earn. A new study has found that men who believe in traditional roles for women earn more money than men who don't, and women with more egalitarian views don't make much more than women with a more traditional outlook.

I can see a few reasons for this result. First off, traditionally minded guys might have more testosterone and basically be more driven than modern egalitarian guys. Second, a traditionally minded guy is going to think his job is bread-winning. He'll work longer at work and less at home because he feels a stronger obligation to bring home the bacon. Even if the wife works he's going to see that as more optional.

Of course, the obligation to be the breadwinner might itself be at least partially biologically caused.

There's another possibility: guys who didn't feel confident at being successful embraced the equal partnership idea between husband and wife in order to lessen their feeling of being unable to fulfill their work obligations. Guys who can't make the grade might be more inclined to rationalize that the grade isn't worth making.

Of course, none of my speculations are politically correct explanations since they don't involve sexual discrimination. But what I see around me in the men and women I meet through work are men and women juggling home and work obligations with the men tending to feel far more often than the women that they've got to come down on the side of giving their all to work. I know men who don't feel that obligation and women who do. But on average I see more work mania in men than women.

Timothy Judge, PhD, and Beth Livingston from the University of Florida, analyzed data from a nationally representative study of men and women who were interviewed four times between 1979 and 2005. A total of 12,686 people, ages 14 to 22 at the beginning of the study, participated; there was a 60 percent retention rate over the course of the study. Results were published in the September issue of the Journal of Applied Psychology, published by the American Psychological Association.

At each of the four interviews, participants were asked about their views on gender roles in the work force and at home. They answered questions such as whether they believed a woman's place is in the home, whether employing wives leads to more juvenile delinquency, if a man should be the achiever outside the home and if the woman should take care of the home and family. Participants were also asked about their earnings, religious upbringing, education, whether they worked outside the home and their marital status, in addition to other topics. Prior studies have shown that men tend to hold more traditional gender roles than do women, though this gap has narrowed over time.

The researchers looked specifically at gender role views as a predictor of a person's earnings. They controlled for job complexity, number of hours worked and education. Their analyses showed that men in the study who said they had more traditional gender role attitudes made an average of about $8,500 more annually than those who had less traditional attitudes.

Marriage and children both increase the odds that male scientists will advance in their careers. Got the wife and kids to support. Gotta work harder. Women are more likely than men to take off from work when a child is sick. Does anyone find that the least bit surprising? Warren Farrell says women who make more work decisions like men make more money. Farrell also says a larger percentage of men than women say that money is their primary motivator at work.

What I want to know: what instincts cause this difference? Are men more driven to compete or more driven to fulfill obligations? Are both instincts responsible for the longer hours worked by men and by the choices that drive them more toward job choices that have higher pay? Are still other drives the cause? The greater male desire for performance-related pay suggests testosterone is the biggest cause.

By Randall Parker 2008 September 22 10:18 PM  Brain Economics
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2008 September 21 Sunday
Battery Packaging Still Unproven On Chevy Volt

General Motors engineers think the individual cells in the candidate battery for the Chevrolet pluggable hybrid Volt design perform well. But the packaging of the batteries presents many problems which do not yet have verified solutions.

Even a few defective cells or connections can dramatically lower the performance of the pack. What's more, the pack includes complex electronic controls for charging each cell, delivering power, and capturing energy from braking to improve vehicle efficiency. And maximizing the battery's life requires a good cooling system. To make matters worse, methods for testing whether a battery pack will last for the life of the car are only now being developed.

"There's only so much known about how to accelerate the testing of batteries," says Greg Cesiel, GM's program director for the E-Flex Vehicle Team, which is developing the Volt and related electric vehicles. Questions remain about how to simulate driving the car and charging the pack, and how to confirm that the pack will survive vibrations and exposure to hot and cold temperatures over the life of a vehicle.

GM still might make their late 2010 release date. But the initial production will be low. My guess is uncertainty about the battery pack longevity is one of the reasons for the initial low production rate. If they end up having to do expensive recalls to fix battery problems better to have few of the cars out on the road. The initial buyers will definitely be extended range testers.

If you have your heart set on buying a Volt and find the battery story worrisome stop and ask yourself whether you can afford the price. GM is initially expected to sell the Volt for $40k and lose money at that price.

Come late 2010 world oil production might be starting down its final decline path. So even at $40k the Volt might seem quite attractive to some drivers. Anyone who can afford $50,000 for an SUV can afford $40,000 for a pluggable hybrid car.

I'm less concerned about getting a pluggable hybrid for myself than seeing that we have the technology to keep industrial society running when world oil production starts its rapid decline.

By Randall Parker 2008 September 21 10:01 PM  Energy Electric Cars
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Old Folks Should Exercise When Losing Weight

Exercise with dieting reduces loss of muscle in old folks.

A group of sedentary and overweight older people placed on a four-month exercise program not only became more fit, but burned off more fat, compared to older sedentary people who were placed on a diet but did not exercise.

The new study also showed that when older people diet without exercising, they lose more lean muscle compared to those who exercise, said senior researcher Bret H. Goodpaster. When they combined weight loss with exercise, it nearly completely prevented the loss of lean muscle mass. The results are important because older people tend to lose muscle mass as they age and too much muscle loss may interfere with activities of daily living.

The study, “Separate and combined effects of exercise training and weight loss on exercise efficiency and substrate oxidation,” appears in the current issue of the Journal of Applied Physiology, published by The American Physiological Society. Francesca Amati, John J. Dube, Chris Shay and Goodpaster, all of the University of Pittsburgh, carried out the study.

Exercise while losing weight is probably good advice at any age. However, the elderly in particular have a problem with a loss of muscle mass called sarcopenia. While some see it mainly as a consequence of decreased exercise with age a number of age-related changes might contribute to sarcopenia.

Thus, in humans between 20 and 80 years of age, muscle mass decreases about 40%, with negative effects on mobility, strength production, metabolic rate and respiratory function. A continuous reparative process is also present in skeletal muscle due to the presence of quiescent adult stem cells, called satellite cells, which are able to change their phenotype when appropriate conditions are present. Sarcopenia is considered an event with a multifactorial etiology: (1) mitochondrial deletion, i.e., replication errors in mitochondrial DNA that lead to an energetic deficit and fiber atrophy; (2) protein synthesis alterations, with an imbalance between protein degradation and the ability of the fibers to synthesize protein; (3) loss of repair ability of the satellite cells, caused by an alteration in the proteic growth factors (mainly IGF–1, mIGF–1, HGF) and hormones (growth hormone, testosterone and estrogens), or by an imbalance of the antioxidant system.

We need stem cell therapies and gene therapies to do repairs on aged muscle tissues. But while we wait for those therapies we should get lots of exercise to minimize the muscle mass loss.

By Randall Parker 2008 September 21 07:40 PM  Aging Diet Weight Studies
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2008 September 20 Saturday
Handheld DNA Testers On Horizon

Microfluidic lab-on-a-chip technology brings within sight hand-held field deployable DNA testers.

September 18, 2008 — Using new "lab on a chip" technology, James Landers hopes to create a hand-held device that may eventually allow physicians, crime scene investigators, pharmacists, even the general public, to quickly and inexpensively conduct DNA tests from almost anywhere, without need for a complex and expensive central laboratory.

"We are simplifying and miniaturizing the analytical processes so we can do this work in the field, away from traditional laboratories, with very fast analysis times, and at a greatly reduced cost," said Landers, a University of Virginia professor of chemistry and mechanical engineering and associate professor of pathology.

Crime scene testing has obvious value. But that won't be the biggest application. Guess what will be? Bar and club testing of prospective mates. Qualify prospective mates for likely personality characteristics. Looking for good material for a longer term relationship? Check their genetic profile. I figure women will find this especially useful. Guys who are looking for one night stands won't care as much.

This group does not have a chip ready for field deployment. But Landers says something important here: the micro-chip field has matured to the point where such a field-deployable handheld DNA tester is now within technological reach.

"This area of research has matured enough during the last five years to allow us to seriously consider future possibilities for devices that would allow sample-in, answer-out capabilities from almost anywhere," he said.

Landers and a team of researchers at U.Va., including mechanical and electrical engineers, with input from pathologists and physicians, are designing a hand-held device — based on a unit the size of a microscope slide — that houses many of the analytical tools of an entire laboratory, in extreme miniature. The unit can test, for example, a pin-prick-size droplet of blood, and within an hour provide a DNA analysis.

A device that can work from saliva or skin flakes will allow more surreptitious testing.

Women determined to have a kid but who have given up on finding a guy to help raise a child (or who simply don't want a guy around) will find this technology useful. A woman who has decided to get pregnant from a one night stand (and I know a woman who did this) could use a handheld DNA tester to decide whether a candidate in a bar has the right stuff to contribute to her baby's DNA.

European researchers think they can develop credit card sized disposable microfluidic testers for less than 50 euros.

Researchers in the European SEMOFS (Surface Enhanced Micro Optical Fluidic Systems) team knew that, to reach their goal of disposable cartridges capable of performing complex medical diagnostic tests quickly and at low cost, they would have to push existing technology to the limit.

“We are targeting state-of-the-art sensitivities or better,” says Jerôme Gavillet, the dissemination coordinator of SEMOFS, “in a system that could be available anywhere for less than €50.”

The team’s goal is a polymer-based device the size of a credit card that would incorporate sophisticated technologies to control the movement of biological fluids, detect the presence of specific proteins, for example early signs of cancer, and analyse the results.

“For each patient, a physician would open the package, put some blood or serum on the card, let it work, and then connect it to a card reader,” says Gavillet.

The relatively inexpensive card reader would display and record what the card had measured.

DNA testing in club and bar scenes wouldn't even have to be surreptitious in many cases. So a woman goes to a club. Some guy hits on her and tries to get her to go home with him. She demands a DNA sample. What's he going to do? Say no? He doesn't have much downside from saying yes. She pulls out a card. Scraps some skin off his inner cheek. Puts sample material into the end of the card. It processes. Then she pulls out a PDA which has a slot to insert the card. She slides in the card and the PDA runs an analysis program she previously downloaded. It tells her the red and green flags based on an ideal profile she previously chose. To get to her desired profile she might have hired a genetic counselor a few months before that bar encounter.

Now, if she likes his qualities but he's short of ideal maybe she takes a pill to prevent pregnancy but goes home with him anyhow.

By Randall Parker 2008 September 20 10:21 PM  Biotech Assay Tools
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2008 September 18 Thursday
Political Orientation Tied To Biological Reaction To Threats

John R. Hibbing of the University of Nebraska Lincoln and John R. Alford of Rice University have made a name for themselves studying twins and political beliefs. They've found evidence of a genetic component for political leanings. In a new paper in Science working with several collaborators they find that those rightward leaning folks who favor a strong national defense react more strongly to threatening visual and sound stimuli. This is additional evidence for very innate cognitive differences as causes of political views.

Although political views have been thought to arise largely from individuals' experiences, recent research suggests that they may have a biological basis. We present evidence that variations in political attitudes correlate with physiological traits. In a group of 46 adult participants with strong political beliefs, individuals with measurably lower physical sensitivities to sudden noises and threatening visual images were more likely to support foreign aid, liberal immigration policies, pacifism, and gun control, whereas individuals displaying measurably higher physiological reactions to those same stimuli were more likely to favor defense spending, capital punishment, patriotism, and the Iraq War. Thus, the degree to which individuals are physiologically responsive to threat appears to indicate the degree to which they advocate policies that protect the existing social structure from both external (outgroup) and internal (norm-violator) threats.

Just watching how much someone blinks in reaction to threatening stimuli will help you figure out their hidden political beliefs. All my professional interrogator readers please take note.

This study involved a group of 46 people who admitted to caring about political issues. Researchers showed participants threatening visual images -- pictures of a very large spider on a person's face, a dazed person with a bloody face and an open wound with maggots in it -- and their skin was monitored for electrical conductivity. Hibbing said skin conductance tests indicate emotion, arousal and attention. By using the skin conductance tests, the researchers are able to track a person's reactions to the threatening stimuli.

In another physiological measure, scientists tested the "orbicularis oculi startle blink response" to record the amplitude or intensity of blinks. They surprised subjects with a sudden, jarring noise and measured how hard they blinked in response to being startled.

In the comments of previous postings I've done on this general area some have argued that once we understand the genetic causes of political differences we'll become more tolerant of opposing viewpoints. I expect the opposite reaction. When people come to understand that it is not possible to persuade their opponents on many topics I expect people will become less tolerant of opposing views. There'll be a reduction in feelings of shared membership in a common identity. Each side will say its views make sense but that the opposing side has a genetic burden that prevents them from understanding the truth.

Hibbing at least holds out the possibility that greater knowledge about the biological causes of political differences will increase tolerance for those who differ. That's probably just his genes talking.

"And if political beliefs do run as deep as we suggest, it becomes easier to understand why political conflict is so persistent. It's not that those who disagree with us politically are being intentionally stubborn but rather that the world seems very different to them. Perhaps recognition of the deep physical nature of these differences will increase political tolerance and understanding," Hibbing concluded.

But Hibbing admits that even with these research results each side can rationalize why their side is right and the other side is wrong.

"Liberals will probably say conservatives are scaredy cats," while conservatives might call liberals naive, he says. "The more important point is that people differ".

Conservatives react more strongly to spiders than liberals?

"Those with the strongest eye or skin reactions to unexpected noises or threatening pictures such as a spider on a person's eyeball tended to endorse political positions that were interpreted as protective of social groups," said John Hibbing, professor of political science at UNL.

Some day a totalitarian government might strap its subjects into chairs, hook up sensors to their skin, and then show them frightening and disgusting pictures. Anyone who does not react correctly will be weeded out from the gene pool by sterilization or death.

When prospective parents (or state birthing units) start choosing genes for their kids will they choose genes that make them more or less likely to recognize threats in their environments? Will offspring genetic engineering make people more conservative or more left-leaning? Or what?

Update: Reacting to this paper Razib pictures a future where adoptive parents screen babies for compatible political leanings.

So it's complicated. But it's comprehensible. Does this matter for you? The physiological responses above are interesting, because it seems like you might be able to test at a very young age for them. If you are an adoptive parent perhaps you might want to screen your potential children for political compatibility. A few weeks ago I listened to a documentary about a woman in Argentina who had been kidnapped as an infant and adopted by a different family. In her particular circumstances here biological parents were left-wing activists killed by a military junta. Her adoptive family were associated with the right-wing junta. She did not find out about her origins until she was 18, but, she observed that she had always had political differences with the family in which she was raised and was active in left-wing politics as a teenager. Remember she was adopted as an infant!

Why stop with adoptions? The bigger screening will get done on embryos by parents conceiving via in vitro fertilization (IVF). In fact, the ability to screen for political compatibility will be one of the reasons why many more parents in the future opt for IVF and pre-implantation genetic diagnosis.

The ability to screen embryos for political leanings will make babies more like their parents and therefore make families more internally consistent. This will increase the mutual incomprehensibility between political factions. A liberal parent won't become more tolerant of conservatives in general as a result of the experience of raising a conservative son. Or a conservative father won't become more tolerant of liberals as a result of raising a surprisingly very radical daughter. There'll be fewer people in the political middle and fewer people with close friends and family members of opposing views. I see a politically more balkanized future.

Update II: John Hawks takes a very critical look at this paper. My reaction: Yes, the paper doesn't prove anything. But compelling evidence exists from twins studies for genetic influences on political views. That these differences might manifest in reactions to threats seems plausible given the very different reaction that conservatives have toward issues related to security and dangers.

By Randall Parker 2008 September 18 11:38 PM  Brain Society
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Single British Women Use Sperm Donors To Conceive

There is a trend for younger British women in their early 30s to use sperm donors to start pregnancies.

So-called "single motherhood by choice" has always existed: around 250 of the 1,100-strong membership of the UK's Donor Conception Network (DCN) are single mothers. Usually this is a decision women come to in their late 30s or early 40s. Not any more. Olivia Montuschi, a spokeswoman for the DCN, reports that the organisation has been approached recently by a several women in their early 30s already considering donor insemination: "It's increasingly an option. They're more likely to conceive [at this age], of course. But the idea that women are giving up on finding a man at 33 or 34 does seem a bit sad."

I see a certain element of brutal honesty involved. For a woman to admit at age 30 that her odds of finding Mr. Right are small is a tough thing to do. Yet some heterosexual women manage to admit this to themselves.

Seeking artificial insemination in your 20s or 30s is not unusual among lesbians (who have no reason to delay), but heterosexual women typically wait to see if they can find a partner first. Using a sperm donor has always been a last resort. Now the process is becoming a first resort.

I expect this option to become much more popular as a result of falling costs of DNA sequencing. Once we know the locations of many of the genetic alleles that contribute to hair color, eye color, facial shape, body shape, intelligence, personality, and other attributes the average woman who chooses to use a sperm donor will be able to get more desired genetic attributes for their child than they would from settling with the best guy they can find for a relationship. Women who use sperm donors will speed up the evolution of the human race.

By Randall Parker 2008 September 18 12:12 AM  Bioethics Reproduction
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2008 September 16 Tuesday
Ghrelin Hunger Hormone Lowered In Pigs

Destruction of a blood vessel that feeds the top part of the stomach cuts ghrelin hunger hormone production. The expectation is that ghrelin reduction via this technique can reduce hunger and obesity.

Johns Hopkins scientists report success in significantly suppressing levels of the "hunger hormone" ghrelin in pigs using a minimally invasive means of chemically vaporizing the main vessel carrying blood to the top section, or fundus, of the stomach. An estimated 90 percent of the body's ghrelin originates in the fundus, which can't make the hormone without a good blood supply.

"With gastric artery chemical embolization, called GACE, there's no major surgery," says Aravind Arepally, M.D., clinical director of the Center for Bioengineering Innovation and Design and associate professor of radiology and surgery at the John Hopkins University School of Medicine. "In our study in pigs, this procedure produced an effect similar to bariatric surgery by suppressing ghrelin levels and subsequently lowering appetite."

The problem with this approach is that it is not easily reversible or tunable. Suppose your appetite gets cut too far. Well, you could end up like an anorexic.

Using X-ray for guidance, members of the research team threaded a thin tube up through a large blood vessel near the pigs' groins and then into the gastric arteries supplying blood to the stomachs. There, they administered one-time injections of saline in the left gastric arteries of five control pigs, and in the other five, one-time injections of sodium morrhuate, a chemical that destroys the blood vessels.

The team then sampled the pigs' blood for one month to monitor ghrelin values. The levels of the hormone in GACE-treated pigs were suppressed up to 60 percent from baseline.

We need researchers to do appetite studies to show that pigs treated with this procedure experience the expected reduction in appetite.

We need dynamic finer granularity ways to control appetite. But for someone who is morbidly obese this procedure could potentially deliver substantial benefits.

By Randall Parker 2008 September 16 10:47 PM  Brain Appetite
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2008 September 15 Monday
Palm Oil For Food And Energy Threatens More Rainforests

Biomass energy with conventional tropical crops is a bad idea because rainforests get destroyed to make room for more palm plantations resulting in habitat loss.

The continued expansion of oil palm plantations will worsen the dual environmental crises of climate change and biodiversity loss, unless rainforests are better protected, warn scientists in the most comprehensive review of the subject to date.

Lead author, Emily Fitzherbert from the Zoological Society of London and University of East Anglia said: "There has been much debate over the role of palm oil production in tropical deforestation and its impacts on biodiversity. We wanted to put the discussion on a firm scientific footing."

Palm oil, used in food, cosmetics, biofuels and other products, is now the world's leading vegetable oil. It is derived from the fruit of the oil palm, grown on more than 50,000-square miles of moist, tropical lowland areas, mostly in Malaysia and Indonesia. These areas, once covered in tropical rainforest, the globe's richest wildlife habitat on land, are also home to some of the most threatened species on earth.

The review, published today in the journal Trends in Ecology and Evolution, singles out deforestation associated with plantation development as by far the biggest ecological impact, but finds that the links between the two are often much more complex than portrayed in the popular press.

Growing palm oil demand threatens to wipe out yet more of the dwindling rainforests.

Within countries, oil palm is usually grown in a few productive areas, but it looks set to spread further. Demand is increasing rapidly and 'its potential as a future agent of deforestation is enormous', the study says.

Most of the suitable land left is within the last remaining large areas of tropical rainforest in Central Africa, Latin America and Southeast Asia. Where oil palm has replaced tropical forest the impact on wildlife depends on what species survive in the new oil palm habitat.

The study confirmed that oil palm is a poor substitute habitat for the majority of tropical forest species, particularly forest specialists and those of conservation concern.

The coming of Peak Oil will boost the demand for biomass energy and speed the destruction of rainforests and other habitats. We need more environmentally friendly energy sources to replace dwindling fossil fuels.

By Randall Parker 2008 September 15 11:09 PM  Energy Biomass
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Slicing Method Cuts Cost of Germanium Solar Cells

A new cutting method for processing germanium photovoltaic (PV) solar cells will cut their cost.

SALT LAKE CITY – University of Utah engineers devised a new way to slice thin wafers of the chemical element germanium for use in the most efficient type of solar power cells. They say the new method should lower the cost of such cells by reducing the waste and breakage of the brittle semiconductor.

The expensive solar cells now are used mainly on spacecraft, but with the improved wafer-slicing method, "the idea is to make germanium-based, high-efficiency solar cells for uses where cost now is a factor," particularly for solar power on Earth, says Eberhard "Ebbe" Bamberg, an assistant professor of mechanical engineering. "You want to do it on your roof.

Higher efficiency of germanium PV will allow a roof to collect a larger fraction of all power used in a home. But cost is a problem because germanium is so expensive.

Germanium serves as the bottom layer of the most efficient existing type of solar cell, but is used primarily on NASA, military and commercial satellites because of the high expense – raw germanium costs about $680 per pound. Four-inch-wide wafers used in solar cells cost $80 to $100 each, and the new cutting method may reduce the cost by more than 10 percent, says Grant Fines, chief technology officer for germanium wafer-maker Sylarus Technologies in St. George, Utah.

On orbital satellites and other space applications where weight is such a huge cost the higher cost of germanium solar cells is justified by their higher efficiency.

Silicon-based solar cells on Earth have maximum efficiency of 20 percent, Fines says. In space, germanium solar cells typically convert 28 percent of sunlight into electricity, but on Earth where solar concentrators are used, they can convert more than 40 percent of sunlight into electricity, and their efficiency theoretically exceeds 50 percent, he adds.

The ability to slice these wafers thinner will both cut production costs and reduce weight which is so critical for space applications.

By Randall Parker 2008 September 15 10:58 PM  Energy Solar
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Topical Estradiol Boosts Skin Collagen Production

You could smear your skin with the hormone estradiol to roll back some of the visible decay from aging.

Laure Rittié, Ph.D., and colleagues at the University of Michigan Medical School, Ann Arbor, recruited 70 healthy volunteers (40 postmenopausal women and 30 men, average age 75 years) with photodamaged skin. For two weeks, volunteers were treated with estradiol three times every other day both on sun-protected areas near the hip and photodamaged skin on the forearm; a 4-millimeter biopsy (tissue sample) was taken from each treatment area 24 hours after the last treatment. Participants also applied estradiol, incorporated into moisturizing cream, to their faces twice per day during the two weeks. A 2-millimeter biopsy was taken from the crow's-foot area near the eye before and 24 hours after the last treatment.

But this treatment does not work on skin suffering from sun damage.

After the two-week treatment period, applying estradiol to the sun-protected hip skin increased levels of collagen and other compounds that promote its production in the women and, to a lesser extent, in the men. "Surprisingly, no significant changes in production were observed in women or men after two-week estradiol treatment of photo-aged forearm or face skin, despite similar expression of estrogen receptors [protein molecules to which estrogen binds] in aged and photo-aged skin," the authors write.

"These findings suggest that menopause-associated estrogen decline is involved in reduced collagen production in sun-protected skin," the authors write. "Because photo-aging is superimposed on natural aging in sun-exposed areas of the skin, our results suggest that alterations induced by long-term sun exposure hinder the ability of topical estradiol to stimulate collagen production in aged human skin in vivo."

This seems doable pretty much immediately. Estradiol is already available. At least in the United States doctors have broad authority to use approved drugs for unapproved reasons. So a willing doctor could write a prescription for estradiol mixed into a cream carrier.

Sun damage leaves a lasting toll.

"Frankly, we were very surprised to find that stimulation of collagen production by topical estrogen treatment was restricted to skin not chronically exposed to sunlight. These results suggest that sun exposure alters the ability of skin to respond to topical estrogen, and point out how difficult it is to repair photoaged skin," Rittie says. The study appears in the new issue of the Archives of Dermatology.

I wonder whether transfer of skin cells from a more shaded part of the body to the face would lead to facial skin that is more responsive to estradiol.

By Randall Parker 2008 September 15 10:06 PM  Aging Appearances
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2008 September 14 Sunday
Companies Sell Photovoltaic Roof Shingles

The idea of building solar photovoltaic shingles has been dreamed about for a long time. Installation of the roof would amount to installation of the PV with little added effort. But attempts to achieve commercial success in this endeavor haven't succeeded commercially so far. Now a couple of companies have teamed up to sell thin film photovoltaic shingles.

In an effort to promote the adoption of solar technology, United Solar Ovonic of Auburn Hills, MI, has teamed with a major roofing company to create a metal roof system that generates electricity from sunlight. The partnership offers seven different prefabricated systems, ranging in capacity from 3 to 120 kilowatts. Tests show that the solar roof panels are rugged and can withstand winds in excess of 160 miles per hour.

The article does not mention cost as compared to other approaches. But in theory this approach ought to be able to hit lower price points since it reduces materials needs and simplifies installation.

They claim the pay-back can be as low as 10 years. That's probably in California which has both high electric power prices and lots of sun. In Washington state with cheap hydro power and a whole lot less sun the economics are probably pretty abysmal.

Centria designs and assembles the solar roof systems using United Solar's adhesive thin films, which can simply be peeled off of their backings and stuck to the roofing materials. The company then distributes the final product through small metal-roofing manufacturers that do the installations for building owners and architects. EnergyPeak comes with a 20-year warranty and, depending on the state in which the solar roof is installed, could pay for itself in less than 10 years, Centria says.

The trend in solar has been toward large PV and concentrating solar power facilities out in deserts. Home PV doesn't capture economies of scale that the big facilities can achieve. But some day PV shingles will become cheap enough that they'll become standard on most new housing construction.

By Randall Parker 2008 September 14 08:06 PM  Energy Solar
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Delaware Offshore Wind Farm Pattern For Future?

A New York Times article on the politics of wind power looks at the long fight for political approval for an offshore wind power project off the coast of Delaware. The Mid-Atlantic Bight region has large quantities of fairly stable wind power.

The amount of power Dhanju was describing, Mandelstam knew from Kempton, was but a small fraction of an even larger resource along what’s known as the Mid-Atlantic Bight. This coastal region running from Massachusetts to North Carolina contained up to 330,000 megawatts of average electrical capacity. This was, in other words, an amount of guaranteed, bankable power that was larger, in terms of energy equivalence, than the entire mid-Atlantic coast’s total energy demand — not just for electricity but for heating, for gasoline, for diesel and for natural gas. Indeed the wind off the mid-Atlantic represented a full third of the Department of Energy’s estimate of the total American offshore resource of 900,000 megawatts.

Wind projects do not usually operate at nameplate (i.e. max) capacity for most of the time. An onshore wind project might average one third of max output. But wind offshore blows more consistently. I would like to know what average capacity utilization is expected for this Delaware project. I would also like to know how vulnerable a project like this is to a category 3 or 4 hurricane.

Wind still accounts for a pretty small amount of total electric generation capacity. The construction of new projects is subsidized by a production tax credit of about 2 cents per kwh. However, in defense of this subsidy coal generates half of the electric power used in the US and coal plants produce a lot of pollution (particulates, mercury, etc) that wind farms do not produce.

Last year, onshore wind power added more than 5,200 megawatts of new electrical capacity to the grid — or nearly a third of America’s new generating capacity, surpassing all other forms of new generation except natural gas and amounting to enough electric capacity to power one and a half million homes.

Was that 5,200 megawatts peak capacity or average capacity? Frequently news reports exaggerate the size of new wind and solar installations by quoting their capacity when the wind blows the hardest and sun shines the brightest. Whereas the average output is usually third or less of the peak for wind and an even lower average output for solar power.

Wind offshore costs more than onshore because the onshore facilities require less capital and are easier to construct and maintain. Some saw the 10 cents/kwh cost of offshore wind electric as too high.

Within Delaware itself, opponents of Bluewater focused on the economics of the project. One report financed by Delmarva Power argued that Bluewater would raise the average electric bill by $20 or more a month. If natural-gas prices flattened or decreased, the company could pass those savings on to its customers — but not if it were stuck in a long-term contract at the Bluewater price of 10 cents per kilowatt hour for the next 25 years.

That's with the production tax credit. So the real cost is probably around 12 cents/kwh. But to put that 10 cents/kwh wholesale electric cost in perspective in April 2008 Delaware residential customers were paying an average of 12.92 cents per kwh as a retail price with the costs of distribution included. That 10 cents for wind does not include distribution costs and billing costs. Plus, intermittent wind requires backup natural gas-fired electric power generation stations that further add to the average cost of electricity. So it seems fair to say that this deal will raise the price of electricity in Delaware in the short term. But in the long term as natural gas and coal prices rise the Bluewater project puts a partial ceiling on electric power costs and probably will reduce long term electric cost inflation in Delaware.

Given the recent increases in electric power prices that April 2008 price table for US state-level electric power costs understates current near future residential electric prices. The Atlantic Bight offshore wind is probably a better deal further north along the US Atlantic coast where as of April 2008 New Jersey residential customers were paying 14.16 cents/kwh while New Yorkers were paying 17.19 cents/kwh, and Connecticut residents were paying 18.56. But the US Middle Atlantic and New England states pay high prices for electricity as compared to most of the rest of the US. Heavy coal burning Kentucky paid only 7.19 cents/kwh and another big coal user Wyoming paid only 7.58 cents/kwh with the US average at 10.44 cents/kwh. Note that higher coal prices have pushed up electric prices since April and effectively coal's cost advantage is shrinking. California is listed at 13.92 cents/kwh. But that is going up substantially.

Key to the Delaware project's approval has been the recent pattern of rapid electric utility rate increases. The Tennessee Valley Authority is boosting electric rates 20%.

News came late last week that Tennessee Valley Authority’s electric rates are going up a total of 20 percent across the Tennessee Valley area, and, according to Fayetteville Public Utilities management, this is the largest total rate hike in nearly 30 years.

...

From December 2007 until July 2008, fuel prices climbed 50 percent for crude oil, 66 percent for natural gas and 128 percent for coal.

Pennsylvanians might be hit by as much as 34% higher electric bills by 2010.

THE ISSUE: Statewide, caps on electric rates have been expiring for the last few years, with PPL Corp. customers facing rate spikes of as much 34 percent in 2010.

Tampa Bay Florida area residents will pay 31% more.

While utilities push to raise electric rates 31 percent on both sides of Tampa Bay, millions of South Florida residents will see their bills increase by only 7 percent.

Virginia and Ohio will also see double digit percentage electric rate increases.

In West Virginia, the state’s largest natural gas utility is asking for a 42 percent rate increase. In Virginia, millions of Dominion Virginia Power customers are seeing their bills rise an average of 18 percent, the largest one-time rate hike there in three decades. And Ohio’s largest electric utility is seeking a 15 percent rate increase annually for the next three years because of high coal prices and a new state environmental law governing emissions that will cost the company money, a spokesman says.

These price increases are narrowing the price gap between wind and existing electric power sources. But this is happening in a way that suggests our medium term prices for electric power will be higher than what we are paying now. But I see a bright side to this. As world oil production declines and the push to substitute natural gas and coal for oil intensifies the ability to use wind electric power will put ceilings on future electric power prices that will leave electric power cheap enough to run modern industrial economies.

Electric power can partially substitute for liquid hydrocarbon fuels in many ways. For example, train lines can be electrified and pluggable hybrid cars can be (and will be) built. Also, electricity can power air-based and ground-based heat pumps for winter heating. So when oil production plummets we will be able to use electric power to keep many elements of our current lifestyles, albeit with considerable transition costs.

Update: In the comments be sure to read the comments by Willett Kempton, a UDel prof who did much of the research on the relative cost competitiveness of the offshore wind choice. He answers questions I raised above and provides additional information as well as links to more details on the study.

By Randall Parker 2008 September 14 02:39 PM  Energy Wind
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Nanodevices Carry Anti-Cancer Agents To Tumors

Researchers are developing small carrier packages that can help focus anti-cancer agents on tumors.

Scientists have developed nanometer-sized ‘cargo ships’ that can sail throughout the body via the bloodstream without immediate detection from the body’s immune radar system and ferry their cargo of anti-cancer drugs and markers into tumors that might otherwise go untreated or undetected.

This delivery system is in an early stage of development, so far tested only on mice.

In a forthcoming issue of the Germany-based chemistry journal Angewandte Chemie, scientists at UC San Diego, UC Santa Barbara and MIT report that their nano-cargo-ship system integrates therapeutic and diagnostic functions into a single device that avoids rapid removal by the body’s natural immune system. Their paper is now accessible in an early online version here.

“The idea involves encapsulating imaging agents and drugs into a protective ‘mother ship’ that evades the natural processes that normally would remove these payloads if they were unprotected,” said Michael Sailor, a professor of chemistry and biochemistry at UCSD who headed the team of chemists, biologists and engineers that turned the fanciful concept into reality. “These mother ships are only 50 nanometers in diameter, or 1,000 times smaller than the diameter of a human hair, and are equipped with an array of molecules on their surfaces that enable them to find and penetrate tumor cells in the body.”

Just because they can put molecules on the surface of these nanodevices does not mean they know which molecules to attach in order to maximize selective targeting of only cancer cells. That's a whole other problem which we really need excellent solutions for. But assuming a solution to that latter problem then these nanodevices could carry chemotherapy toxins into cancer cells to selectively kill only cancer cells.

These microscopic cargo ships could one day provide the means to more effectively deliver toxic anti-cancer drugs to tumors in high concentrations without negatively impacting other parts of the body.

They tested imaging enhancement payloads in mice. But this mechanism could also be used to deliver toxic chemotherapy to tumours.

The researchers loaded their ships with three payloads before injecting them in the mice. Two types of nanoparticles, superparamagnetic iron oxide and fluorescent quantum dots, were placed in the ship’s cargo hold, along with the anti-cancer drug doxorubicin. The iron oxide nanoparticles allow the ships to show up in a Magnetic Resonance Imaging, or MRI, scan, while the quantum dots can be seen with another type of imaging tool, a fluorescence scanner.

Their bigger problem is probably going to be how to get highly selective on just which cells these packages will enter.

The researchers are now working on developing ways to chemically treat the exteriors of the nano ships with specific chemical “zip codes,” that will allow them to be delivered to specific tumors, organs and other sites in the body.

Can this approach cure cancer? The question will depend in part on whether the surfaces of cancer cells look different enough from normal to provide highly selective delivery into cancer cells.

But this approach could be enhanced with smart payloads. Imagine a payload that includes a genetic sequence. It could get activated only in cells which internally look like cancer cells. So the package might make it into cancerous and non-cancerous cells but only do real damage in cancer cells. But that would probably be a bigger payload than a chemotherapy agent. So that makes packaging harder to do.

Once we can cure cancer and repair our internal organs with stem cells and replacement organs our big problem is going to be brain aging. Alzheimer's, Parkinson's, strokes, and other causes of dementia and brain decay will all need solutions. Alzheimer's might be solved even before cancer. But the other diseases of aging brains will be tougher problems to solve.

By Randall Parker 2008 September 14 12:24 AM  Nanotech for Biotech
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2008 September 13 Saturday
IAEA Sees Nuclear Power Growth To 2030

The UN International Atomic Energy Agency expects more growth in nuclear power to 2030.

The IAEA has revised upwards its nuclear power generation projections to 2030, while at the same time it reported that nuclear´s share of global electricity generation dropped another percentage point in 2007 to 14%. This compares to the nearly steady share of 16% to 17% that nuclear power maintained for almost two decades, from 1986 through 2005.

Part of the drop in nuclear power's electric generation marketshare comes from an earthquake in Japan that took several nuclear power plants off-line. But I suspect very rapid coal electric power plant construction in China played a role as well. The Chinese are cranking out the coal plants. If they switched to cranking out nuclear power plants instead the air of the world would be a lot cleaner.

The IAEA thinks the number of nuclear power plants will go up in the next 20 or so years. But they aren't sure by how much. But even their high case isn't enough to make much of a dent in the enormous growth in coal electric power plant construction.

In its 2008 edition of Energy, Electricity and Nuclear Power Estimates for the Period to 2030, the IAEA expects global nuclear power capacity in 2030 to range from a low case scenario of 473GW(e), some 27% higher than today´s 372 GW(e), to a high case scenario of 748 GW(e), i.e., double today´s capacity.

In the US alone coal produces about two and a half times more electricity than nuclear. In China coal accounts for 4/5ths of total electric power generation and in July 2008 electric power generation was up by 8.1% over a year earlier. That's coal growth and shows how far nuclear power is from displacing coal. Still, at least projections for future nuclear power growth are up.

"Over the last five years projections have gone up for several reasons," said Hans-Holger Rogner, Head of the IAEA´s Nuclear Energy Planning and Economic Studies Section.

"Performance has improved greatly since the 1980s, and the safety record of the types of reactors on the market today is excellent. In addition, the average load factor of the global reactor fleet has increased from 67% in 1990 to more than 80% since early 2000. Rising costs of the dominant alternatives, particularly natural gas and coal, energy supply security and environmental constraints are also factors that are contributing to nuclear´s appeal."

The report´s projections reflect major expansion plans that are under way in key countries like China and India, and new policies and interest in nuclear power that are emerging in countries like the UK and USA.

But while projections for nuclear power´s future rose, its share of the world´s electricity generation today dropped from 15% in 2006 to 14% in 2007.

"The reason is that while total global electricity generation rose 4.8% from 2007 to 2008, nuclear electricity actually dropped slightly," Rogner commented.

I expect an increase in interest in nuclear power in Europe due to Russia's conflict with Georgia. Europe suffers from a compact geography and northern location that place limits on how big a role solar power can play. The compact geography and dense population also place limits on wind's potential. So nuclear seems especially necessary in Europe.

Brazil is embracing a nuclear future.

SÃO PAULO, 9/12/08 - The Brazilian Mines and Energy minister, Edison Lobão, said today in Angra dos Reis (state of Rio de Janeiro) that Brazil has already decided to give priority to the resumption of the country's nuclear program. Some 60 nuclear power plants should be built in the next 50 years. Each unit should have generation capacity for 1,000 megawatts.

Will the cost of coal get bid up so high that nuclear power becomes more competitive? Coal supplies probably will have the biggest effect on the future of nuclear power. Once world oil production starts declining the demand for coal for use in coal-to-liquid processing to make liquid fuels for transportation might drive up the price of coal high enough to make nuclear power more cost competitive. Also, political pressures to lower carbon dioxide emissions might help nuclear power.

By Randall Parker 2008 September 13 10:30 PM  Energy Nuclear
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2008 September 12 Friday
US Congress Looks Set To Allow Offshore Drilling

The Democrats feel under so much pressure in an election year from voters unhappy with high gasoline prices that House Democrats are ready to allow limited offshore drilling. The 50 to 100 mile limit still will place some oil fields off-limits. But $5 gasoline in a few years will melt those limits as well.

Even more surprising, the turnabout is led by the House speaker, Nancy Pelosi, who has a history of fighting oil drilling going back to the early days of her career in California.

Under a measure being assembled for a vote in the House next week, oil rigs could go up 50 miles from the shores of states that welcome drilling and 100 miles off any section of the United States coast — a stark reversal on an issue that has been a Democratic environmental touchstone since the 1980s.

“It shows what $4 a gallon gas will do,” said Daniel J. Weiss, a senior fellow on energy and climate issues at the Center for American Progress Action Fund, an advocacy group.

By the time gasoline hits $6 per gallon the ban on drilling in the Arctic National Wildlife Refuge (ANWR) will get lifted as well. The environmentalists in the Democratic party didn't intend this. But they've preserved the oil for use after the world hits Peak Oil. So that ANWR will will get sold for $200+ per barrel.

Offshore drilling is a local issue in California coastal areas. The Santa Barbara County Board of Supervisors voted in support of offshore drilling.

A divided Santa Barbara County Board of Supervisors voted Tuesday in support of offshore drilling, after an impassioned daylong hearing in which this year's record gas prices trumped the memory of a disastrous oil spill.

By a 3-2 vote that broke along geographic lines, supervisors agreed to send a letter to Gov. Arnold Schwarzenegger urging him to change state policy and "allow expanded oil exploration and extraction" off the county's coast.

My guess is Arnie won't try to lift the drilling ban until Californians feel in a crisis from $6 or $7 gasoline. But California will flip on this issue too as the economy sinks with Peak Oil.

Santa Barbara City voted 5-1 for a resolution against new drilling.

Looking to spitshine the South Coast’s recently tarnished environmental legacy, the Santa Barbara City Council took on the issue of offshore oil drilling this week, declaring unequivocally in an official resolution to all who might listen that they are against any new oil and gas leases in the waters off our shores.

I'm not telling you to support or oppose offshore drilling. I'm just saying that once world oil production comes off its plateau and starts declining people will become desperate for more energy supplies. Opposition to drilling, opposition to nuclear power, and other forms of opposition to energy will evaporate.

By Randall Parker 2008 September 12 12:03 AM  Energy Policy
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2008 September 11 Thursday
Embryonic Stem Cells Repair Heart Failure In Mice

At least in mice heart repair with embryonic stem cells works.

ROCHESTER, Minn. -- Mayo Clinic investigators have demonstrated that stem cells can be used to regenerate heart tissue to treat dilated cardiomyopathy, a congenital defect. Publication of the discovery was expedited by the editors of Stem Cells and appeared online in the "express" section of the journal's Web site at http://stemcells.alphamedpress.org/.

And yet people do not complain that mice get all the great medical treatments first. Why is that? My theory: the mice have somehow brainwashed us. PETA (People for the Ethical Treatment of Animals) are really a secret organization of people who are immune to mouse brainwashing. They pose as animal rights activists. But in reality they are human rights activists trying to move humans ahead of mice in priority for treatment development. If the mice find out that I've told you this then I'll probably have to get some cats as bodyguards.

The key here is that the scientists used embryonic stem cells. This seems pretty straightforward to try in humans except for the regulatory obstacles that stand in the way.

The team reproduced prominent features of human malignant heart failure in a series of genetically altered mice. Specifically, the "knockout" of a critical heart-protective protein known as the KATP channel compromised heart contractions and caused ventricular dilation or heart enlargement. The condition, including poor survival, is typical of patients with heritable dilated cardiomyopathy.

Researchers transplanted 200,000 embryonic stem cells into the wall of the left ventricle of the knockout mice. After one month the treatment improved heart performance, synchronized electrical impulses and stopped heart deterioration, ultimately saving the animal's life. Stem cells had grafted into the heart and formed new cardiac tissue. Additionally, the stem cell transplantation restarted cell cycle activity and halved the fibrosis that had been developing after the initial damage. Stem cell therapy also increased stamina and removed fluid buildup in the body, so characteristic in heart failure.

Embryonic stem cells are pluripotent. That means they can become all other cell types. Another way to create pluripotent stem cells without using an embryo will eventually make it possible to create pluripotent stem cells that do not raise big ethical opposition.

The use of stem cells to do repairs will be easier for some organs than others. I'm hopeful from reports like the one above that most heart problems will be among the easier problems to solve.

Looking ahead 20 years I'm most worried about cancer and brain aging. I would be surprised if organ failures will still kill a lot of people in industrialized countries 20 years from now. Will cancer become easily curable in 20 years? Maybe. But brain aging is going to be the hardest problem to solve.

By Randall Parker 2008 September 11 11:13 PM  Biotech Heart Cardiovascular
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Mediterranean Diet Seen Boosting Longevity

Cut back on meats and dairy products if you want to live longer.

Sticking to a full Mediterranean diet provides substantial protection against major chronic diseases including heart disease, cancer and Parkinson's and Alzheimer's disease, according to a study published on bmj.com today.

A 'score' based on adherence to the Mediterranean diet could be used as an effective preventive tool for reducing the risk of premature death in the general population, say the authors.

The Mediterranean diet from populations bordering the Mediterranean Sea has a reputation for being a model of healthy eating and contributing to better health and quality of life. It is rich in olive oil, grains, fruits, nuts, vegetables, and fish, but low in meat, dairy products and alcohol.

Make the grains whole grains and go light on them. Better to get your carbos from beans and other lower glycemic index foods.

People who stuck closest to the diet were healthier.

A team of researchers from the University of Florence assessed 12 international studies, which collectively included more than 1.5 million participants whose dietary habits and health were tracked for follow-up periods ranging from three to 18 years.

All the studies examined the concept of using a numerical score to estimate how much people stuck to the diet, called an 'adherence score'.

The researchers found that people who stuck strictly to a Mediterranean diet had significant improvements in their health, including a 9% drop in overall mortality, a 9% drop in mortality from cardiovascular disease, a 13% reduction in incidence of Parkinson and Alzheimer's disease, and a 6% reduction in cancer.

What vices do you have that pull you away from an ideal diet? Or do you find an ideal diet inconvenient due to work schedule and travel?

By Randall Parker 2008 September 11 05:59 PM  Aging Diet Studies
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2008 September 10 Wednesday
Knee Surgery No Help For Osteoarthritis

Knee surgery for osteoarthritis is big business but worthless. The lesson here is that we need stem cell therapies and other rejuvenating therapies. We need to reverse the processes of aging.

Running from 1999 to 2007, the study treated 178 London-area men and women with an average age of 60. All study participants received physical therapy as well as medications such as ibuprofen or acetaminophen, but 86 of the patients also received surgery consisting of lavage and arthroscopic debridement at LHSC. At several time intervals post-treatment, the researchers found both patient groups experienced comparable improvements in joint pain, stiffness, and function, but surgery provided no additional benefit.

Orthopedic surgeon and study co-author Dr. Bob Litchfield emphasizes this study addresses only arthritis-related knee problems. "Although this study did not show a significant therapeutic benefit of arthroscopic debridement in this patient population, knee arthroscopy is still beneficial in many other conditions affecting the knee, such as meniscal repair and resection, and ligament reconstruction." Litchfield is the Medical Director of the Fowler Kennedy Sport Medicine Clinic. He's also a professor In the Department of Surgery at Western's Schulich School of Medicine & Dentistry and a scientist with the Lawson Health Research Institute. "As surgeons, we need to know when things are working and when they're not. If this particular technique is not working for this subgroup of patients, we better come up with something else that does."

A 2002 study demonstrating similar results to this study was broadly dismissed by the medical community, and arthroscopic surgery of the knee remains a common treatment for joint pain and stiffness. But in this latest study the researchers conclude "based on the available evidence, we believe that the resources currently allocated towards arthroscopic surgery for osteoarthritis would be better directed elsewhere."

If you have parts that are worn out the solution is to make those parts young again. Surgery by itself can't do that. So surgery does not help.

By Randall Parker 2008 September 10 11:04 PM  Aging Treatment Studies
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2008 September 09 Tuesday
Fish Consumption And Breast Feeding Boost Infant Brain Development

Eating fish during pregnancy and longer periods of breast feeding boost brain development.

BOSTON, Mass. (Sept. 9, 2008) — Both higher fish consumption and longer breastfeeding are linked to better physical and cognitive development in infants, according to a study of mothers and infants from Denmark. Maternal fish consumption and longer breastfeeding were independently beneficial.

"These results, together with findings from other studies of women in the U.S. and the United Kingdom, provide additional evidence that moderate maternal fish intake during pregnancy does not harm child development and may on balance be beneficial," said Assistant Professor Emily Oken, lead author of the study.

The study, which appeared in the September issue of the American Journal of Clinical Nutrition, was conducted by researchers from the Department of Ambulatory Care and Prevention of Harvard Medical School and Harvard Pilgrim Health Care and the Maternal Nutrition Group from the Department of Epidemiology at Statens Serum Institut in Copenhagen, Denmark. These findings provide further evidence that the omega-3 fatty acids found in fish and compounds in breast milk are beneficial to infant development.

The study team looked at 25,446 children born to mothers participating in the Danish Birth Cohort, a study that includes pregnant women enrolled from 1997-2002. Mothers were interviewed about child development markers at 6 and 18 months postpartum and asked about their breastfeeding at 6 months postpartum. Prenatal diet, including amounts and types of fish consumed weekly, was assessed by a detailed food frequency questionnaire administered when they were six months pregnant.

During the interviews mothers were asked about specific physical and cognitive developmental milestones such as whether the child at six months could hold up his/her head, sit with a straight back, sit unsupported, respond to sound or voices, imitate sounds, or crawl. At 18 months, they were asked about more advanced milestones such as whether the child could climb stairs, remove his/her socks, drink from a cup, write or draw, use word-like sounds and put words together, and whether they could walk unassisted.

The children whose mothers ate the most fish during pregnancy were more likely to have better motor and cognitive skills. For example, among mothers who ate the least fish, 5.7% of their children had the lowest developmental scores at 18 months, compared with only 3.7% of children whose mothers had the highest fish intake. Compared with women who ate the least fish, women with the highest fish intake (about 60 grams - 2 ounces - per day on average) had children 25% more likely to have higher developmental scores at 6 months and almost 30% more likely to have higher scores at 18 months.

Longer duration of breastfeeding was also associated with better infant development, especially at 18 months. Breastmilk also contains omega-3 fatty acids. The benefit of fish consumption was similar among infants breastfed for shorter or longer durations.

Ladies, select fish that are low in mercury. Or take fish oil pills.

So then if fish consumption causes greater development of the anterior prefrontal cortex will the kids raised with more omega 3 fatty acids exercise more self control? Do fish boost free will?

Other ways to optimize brain development exist. Higher calcium consumption during pregnancy might reduce fetal lead exposure.

ANN ARBOR, Mich.---Pregnant women who take high levels of daily calcium supplements show a marked reduction in lead levels in their blood, suggesting calcium could play a critical role in reducing fetal and infant exposure.

A new study at the University of Michigan shows that women who take 1,200 milligrams of calcium daily have up to a 31 percent reduction in lead levels.

Women who used lead-glazed ceramics and those with high bone lead levels showed the largest reductions; the average reduction was about 11 percent, said Howard Hu, chair of the Department of Environmental Health Sciences at the School of Public Health.

By Randall Parker 2008 September 09 11:14 PM  Brain Development
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Same Brain Region For IQ And Financial Self Control

The anterior prefrontal cortex is key to both intelligence and the ability to delay gratification in order to get more.

If you had a choice between receiving $1,000 right now or $4,000 ten years from now, which would you pick? Psychologists use the term “delay discounting” to describe our inability to resist the temptation of a smaller immediate reward in lieu of receiving a larger reward at a later date. Discounting future rewards too much is a form of impulsivity, and an important way in which we can neglect to exert self-control.

Previous research suggests that higher intelligence is related to better self-control, but the reasons for this link are unknown. Psychologists Noah A. Shamosh and Jeremy R. Gray, from Yale University, and their colleagues, were interested in testing the idea that certain brain regions supporting short-term memory play a critical role in this relationship.

"It has been known for some time that intelligence and self-control are related, but we didn't know why. Our study implicates the function of a specific brain structure, the anterior prefrontal cortex, which is one of the last brain structures to fully mature,” said Dr. Shamosh.

In this study, 103 healthy adults were presented with a delay discounting task to assess self-control: a series of hypothetical choices where they had to choose between two financial rewards, a smaller one which they would receive immediately or another, larger reward which would be received at a later time. The participants then underwent a variety of tests of intelligence and short term memory. On another day, subjects’ brain activity was measured using fMRI, while they performed additional short-term memory tasks.

The results show that participants with the greatest activation in the brain region known as the anterior prefrontal cortex also scored the highest on intelligence tests and exhibited the best self-control during the financial reward test. This was the only brain region to show this relation. The results appear in the September issue of Psychological Science, a journal of the Association for Psychological Science.

Previous studies have shown that the anterior prefrontal cortex plays a role in integrating a variety of information. The authors suggest that greater activity in the anterior prefrontal cortex helps people not only to manage complex problems, resulting in higher intelligence, but also aids in dealing with simultaneous goals, leading to better self-control.

A smarter society is a society where people will have more self control and pursue longer term goals. The declining cost of DNA sequencing will soon bring us many of the genetic alleles that cause different levels of capability in the anterior prefrontal cortex. Then individuals will start considering genetic profiles and likely offspring intelligence when choosing mates. Also, in vitro fertilization (IVF) with pre-implantation genetic diagnosis (PIGD or PGD) will become popular among those who recognize the importance of making their offspring as smart as possible.

If a smarter person has a more powerful anterior prefrontal cortex which allows the person to control their impulse to act on immediate desires then does a smarter person have more free will?

By Randall Parker 2008 September 09 11:07 PM  Brain Economics
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Almost 40% Of North American Fish Species Threatened

The world is overpopulated by humans. Isn't 6 billion enough? Human encroachments are cutting back on the numbers of fish.

Nearly 40 percent of fish species in North American streams, rivers and lakes are now in jeopardy, according to the most detailed evaluation of the conservation status of freshwater fishes in the last 20 years.

The 700 fishes now listed represent a staggering 92 percent increase over the 364 listed as "imperiled" in the previous 1989 study published by the American Fisheries Society. Researchers classified each of the 700 fishes listed as either vulnerable (230), threatened (190), or endangered (280). In addition, 61 fishes are presumed extinct.

The new report, published in Fisheries, was conducted by a U.S. Geological Survey-led team of scientists from the United States, Canada and Mexico, who examined the status of continental freshwater and diadromous (those that migrate between rivers and oceans) fish.

"Freshwater fish have continued to decline since the late 1970s, with the primary causes being habitat loss, dwindling range and introduction of non-native species," said Mark Myers, director of the USGS. "In addition, climate change may further affect these fish."

If immigration continues unabated the United States alone will have 450 million people by the middle of the century. Habitats will shrink further and we'll lose lots of these species of fish along with other types of species.

Lots of types of fish are threatened.

The groups of fish most at risk are the highly valuable salmon and trout of the Pacific Coast and western mountain regions; minnows, suckers and catfishes throughout the continent; darters in the Southeastern United States; and pupfish, livebearers, and goodeids, a large, native fish family in Mexico and the Southwestern United States. 

Nearly half of the carp and minnow family and the Percidae (family of darters, perches and their relatives) are in jeopardy. Fish families important for sport or commercial fisheries also had many populations at risk. More than 60 percent of the salmon and trout had at least one population or subspecies in trouble, while 22 percent of sunfishes — which includes the well-known species such as black bass, bluegill and rock bass — were listed. Even one of the most popular game species in the United States, striped bass, has populations on the list.

This problem is going to get worse. Population growth and economic growth along with depleting fossil fuels all push more land into human uses.

By Randall Parker 2008 September 09 10:00 PM  Trends Extinction
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Stephen Colbert Commits Space Fraud With His DNA

Stephen Colbert is pretending to save his DNA for use by aliens who might show up once humanity is extinct. This is fraud!

NEW YORK, September 8, 2008 -- Stephen Colbert continues to make late-night television space history. On “The Colbert Report” in May, he was the first host in late-night to interview an astronaut, Garrett Reisman, in space. Now, Colbert plans to save humanity when he has his DNA digitized and sent to the International Space Station (ISS) with famed game designer Richard Garriott.

“I am thrilled to have my DNA shot into space, as this brings me one step closer to my life-long dream of being the baby at the end of 2001," said Colbert.

“In the unlikely event that Earth and humanity are destroyed, mankind can be resurrected with Stephen Colbert’s DNA,” said Garriott. “Is there a better person for us to turn to for this high-level responsibility?”

In October, Garriott will travel to the ISS and deposit the “Immortality Drive,” a time capsule which will include human DNA and records of humanity’s greatest accomplishments. This collection of data including Colbert’s DNA and accomplishments, along with personal messages left by visitors at www.OperationImmortality.com, will serve as a remote offsite backup of the human race.

A recent news report on the need to move the ISS to avoid Russian satellite junk shows why the report above is a fraud perpetrated on a naive and unsuspecting pseudo-news watching public: The space station decays in orbit by 100 to 300 feet per day and once the human race goes extinct (and probably well before then) the space station will reenter Earth's atmosphere and burn up. Colbert's DNA sequence will burn up looking like a comet across the night sky.

In a status report, NASA said the course change was required because the space debris was predicted to come within about a mile (1.627 kilometers) of the station — bringing the risk of a collision above the threshold for a "debris avoidance maneuver."

Normally, such maneuvers involve raising the station's altitude, to compensate for the orbit's inexorable decay from air drag. Such decay lowers the orbit by 100 to 300 feet per day, and requires periodic engine firings by docked spacecraft or rockets installed on the station itself.

The ISS is in too low an orbit to stay up in space until space alien archaeologists show up to pick over the wreckage of our vanquished civilization. To preserve DNA sequences for eventual recreation of humans in an alien zoo would require use of either a geosynchronous high orbit or perhaps a pod on the Moon.

Update: If Colbert was serious he'd get his DNA sequence placed on a space probe. Failing that there's something he can do with his DNA information: Put it in the Yucca Mountain facility designed for storing nuclear waste. The place was chosen to be geographically very stable and to last a long time. The radiation signs outside will alert aliens that the facility is something special. They'll dispatch robots to investigate. The robots can recreate his DNA in an artificially constructed embryo using microfluidic devices, put the embryo in an artificial womb, and then Colbert Jr. can be born in the arms of a loving alien robo-mom.

By Randall Parker 2008 September 09 09:33 AM  Space Exploration
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2008 September 08 Monday
Low Vitamin B-12 Seems To Cause Faster Brain Shrinkage

Keep up your vitamin B-12 levels so that your brain doesn't shrink any faster than it has to. Oh, and we really need gene therapies, stem cell therapies, and some nanobot therapies to repair and rejuvenate aging brains so that they do not shrink at all.

Older people with lower than average vitamin B12 levels were more than six times more likely to experience brain shrinkage, researchers concluded.

The University of Oxford study, published in the journal Neurology, tested the 107 apparently healthy volunteers over a five-year period.

So now the question is whether supplements could slow brain shrinkage and keep us smarter longer. Aging of the digestive tract will prevent at least some elderly from absorbing enough B-12 however and for them periodic B-12 injections are needed.

Professor David Smith, who directs the Oxford Project to Investigate Memory and Ageing, said he now planned a trial of B vitamins in the elderly to see if taking them could slow brain shrinkage.

This makes eating fish a two-fer. You get B-12 plus omega 3 fatty acids. Both help the brain. Omega 3 fatty acids reduce occurrence of brain lesions.

Oh, and like so many things these days, there's a genetic angle. The FUT2 gene

Boston, MA - Researchers at the Harvard School of Public Health (HSPH) and their collaborators at Tufts University and the National Cancer Institute (NCI) have identified a common genetic influence on B12 vitamin levels in the blood, suggesting a new way to approach the biological connections between an important biochemical variable and deficiency-related diseases.

"The news here is the discovery of a robust genetic predictor of vitamin B12 levels," said David Hunter, the Vincent L. Gregory Professor of Cancer Prevention and director of the Program in Molecular and Genetic Epidemiology at HSPH and senior author of the study. "This is an example of the way we're going to understand more about how levels of vitamins and other nutrients in the body are partially determined by genetic factors as well as by what we eat."

But the FUT2 gene only accounted for a small portion of the variation of blood plasma B12 levels. But that could be important.

In the study, the FUT2 genetic variant accounted for about three percent of the variation in B12 plasma levels, Hazra said.

6 or 7 years from now most of us will know our personal genetic profiles and we'll know which nutrients we need to make special efforts to get more or less of. Nutrigenomics is coming to the mainstream soon.

By Randall Parker 2008 September 08 08:17 PM  Aging Diet Brain Studies
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Gene Causes Obesity At Low Exercise Level

You might want to calculate your calories burned per mile walking at different speeds if you are having trouble fighting your weight. If you've got the wrong copy of a gene called FTO one solution is to become an Amish farmer to get the exercise you need to control your weight.

High levels of physical activity can help to counteract a gene that normally causes people to gain weight, according to a new study by researchers at the University of Maryland School of Medicine. They analyzed gene variants and activity levels of the Old Order Amish in Lancaster County, Pa., and found that the obesity-related FTO gene had no effect on individuals who were the most physically active.

"Our results strongly suggest that the increased risk of obesity due to genetic susceptibility can be blunted through physical activity," the authors conclude. "These findings emphasize the important role of physical activity in public health efforts to combat obesity, particularly in genetically susceptible individuals." The results of the study are being published in the Sept. 8, 2008, issue of the Archives of Internal Medicine.

Soren Snitker, M.D., Ph.D., the senior author and an assistant professor of medicine and pediatrics at the University of Maryland School of Medicine, says, "Our study shows that a high level of physical activity can 'level the playing field,' equalizing the risk of obesity between those who have copies of the FTO gene variant and those who don't."

The FTO gene recently has been linked to obesity and increased body mass index, or BMI, in several large-scale studies. More than half of all people of European descent have one or two copies of a variation of this gene, British scientists reported last year. Individuals with two copies of the gene variant are on average 7 pounds heavier and 67 percent more likely to be obese than those who don't have it.

We are not adapted to industrialized environments. Though not everyone does equally poorly in low exercise lifestyles. Therefore it is not surprising that scientists can find specific genetic variations that make some more or less adapted to less physical activity.

The more active among the Amish are known to burn a lot more calories than the vast majority of people who live in industrialized countries. Though they are not all intensely physically active since they do not all work in the same occupation. Even different kinds of farming introduce different levels of physical activity.

University of Maryland researchers found this same link between variations of the FTO gene and increased risk of obesity in their study of 704 Amish men and women. But, in examining the gene in this unique group of people with a similar genetic background and active lifestyle, the researchers also found that high levels of physical activity helped to counteract the gene's effects. "Having multiple copies of FTO gene variants had no effect on body weight for people who were the most physically active, regardless of whether they were men or women. But in less active people, the association between the gene and increased BMI was significant," says Evadnie Rampersaud, Ph.D., the lead author and a former postdoctoral fellow at the University of Maryland School of Medicine who is now at the University of Miami Institute for Human Genomics. "This provides evidence that the negative effects of the FTO variants on increasing body weight can be moderated by physical activity."

You have to burn an extra 900 kilocalories per day in order to fully control for the effects of the weight-boosting FTO variant.

Participants were classified as having "high activity" or "low activity" levels. The more active people used 900 more kilocalories, or units of energy, a day, which translates into three to four hours of moderately intensive activity, such as brisk walking, housecleaning or gardening.

This isn't to say that a lower level of exercise wouldn't help. In fact, jogging 30 miles per week lowers the rate of weight gain but does not stop it entirely. Those 30 miles probably amount to about 120 kcal per mile or 3600 kcal per week. That falls short of the extra 7 times 900 kcal per day for these Amish or 6300 kcal per week. So maybe if you ran 52.5 miles per week that'd prevent weight gain. Um, I'm not up for doing that. If you want to save time running at 10 mph burns over 1000 calories per hour.

In another study a group of Old Order Amish in southern Ontario were found to walk about 5 times further per day than the average American. They had a very low rate of obesity too.

But burn calories they surely do, as his study in the January edition of Medicine and Science in Sports and Exercise demonstrates.

The 98 Amish adults Bassett surveyed wore pedometers for a week. The men averaged 18,000 steps a day. The women took an average of 14,000 steps.

The men spent about 10 hours a week doing heavy work like plowing, shoeing horses, tossing hay bales, and digging. The women spent about 3.5 hours a week at heavy chores. Men spent 55 hours a week in moderate activity; women reported 45 hours a week of moderate chores like gardening and doing laundry.

The obesity rate among the participants was 4 percent, as determined by body mass index, or BMI. The current obesity rate among the adult American population is a whopping 31 percent.

By contrast the average American takes about 3000 steps per day. A 200 lb person walking 3 mph can burn 70 extra kcals per mile as compared to sitting still. So you'd need to walk over 12 miles per day to equal the extra calories burned by a heavily active Old Order Amish farmer. You could walk at a brisk pace and cut your time down from 4 hours though or even jog. You could also weight train to build up your muscles in order to boost your rate of calorie burn while sitting still.

By Randall Parker 2008 September 08 05:42 PM  Aging Diet Weight Studies
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Adult To Pluripotent Stem Cells Were Possible 5 Years Sooner

Jane Gitschier, with the UCSF Departments of Medicine and Pediatrics, interviewed U Wisc stem cell researcher Jamie Thomson for PLoS Genetics. Thomson was the first person to derive a human embryonic stem cell line and has other firsts to his credit. The whole interview is worth a read. But the most interesting point to me related to how Thomson's lab first figured out how to create human pluripotent stem cells (capable of becoming all cell types) without using embryonic cells as a starting point. Thomson could have made the induced pluripotent stem cell breakthrough 5 years sooner but the problem seemed it must be really hard to solve and so he didn't immediately try the easiest ways to make this happen.

Gitschier: And now, you've developed a new technology that may obviate some of these political and funding issues: Induced pluripotent stem [IPS] cells. Set the stage for that for me.

Thomson: The stage was Dolly really—that changed the mindset of developmental biologists in a big way, including mine. About 5 years ago, I hired the post-doc [Junying Yu] who was the first author on our paper [published in 2007]. My conversation with her at the time was that we have to try this, even though it probably isn't going to work. And it's probably like a 20-year problem, because the thought back then was that it has just got to be really complicated. All those little factors, and how can you manipulate all of those? It didn't really seem sensible.

I thought by doing such a combinatorial screen, we might get PARTIAL reprogramming in some way.

Gitschier: Describe what you mean by combinatorial screen.

Thomson: I'll tell you what we did, and it was very similar to what Yamanaka did in the mouse. We were doing it at the same time, but he got ahead of us because mouse work is actually much faster than human work, although we actually had a partially defined system with a more complicated set of factors prior to publication of his mouse work.

Back in the '70s, it was found that if you fuse blood cells with embryonic carcinoma [EC] cells—ES cells hadn't been derived yet—that within that heterokaryon, the dominant phenotype could either be the blood cell or the EC cell, but it was often the EC cell. So that was early evidence for reprogramming.

We started to do similar experiments several years ago, in which we took ES cell–derived blood cells. We had a well-defined, cloned, expandable hematopoietic cell type that we used in cell fusions for a model for reprogramming, and we showed that the dominant phenotype was the ES cell.

We did gene expression analysis of both those cell types and started to clone genes that were specifically enriched in ES cells. So Junying cloned between 100 and 200 genes, and she started taking pools of them to test for reprogramming ability and we used a knock-in human ES cell line that turns green and gets drug resistant when it reprograms to an ES cell state. Last summer, Junying kept paring it down until there were four factors, and we repeated it in different cell types.

It was kind of a dumb thing to do—it worked and that is nice. If you look at the factors we found, OCT4, SOX2, and NANOG—they're everybody's favorite genes already—these are key pluripotency genes. But we had this mindset, which was so strong, that it HAD to be complicated, we just never tested them! It would have been a lot easier to just test them 5 years ago and gotten it done in a month or two!

Gitschier: These IPS cells won't be restricted in terms of federal funding?

Thomson: No. That changes everything.

This breakthrough speeds up progress toward the development of useful stem cell therapies because it opens up the funding floodgates for working with human pluripotent stem cells by producing them in a way that doesn't involve use of a human fetus. But the gene twiddling involved in this technique might not produce cells safe enough for injection into humans. More refined ways to manipulate adult cells to revert them into an embryonic state might be necessary to produce cells that won't go cancerous.

By Randall Parker 2008 September 08 02:36 PM  Biotech Stem Cells
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2008 September 07 Sunday
13 Genetic Letters Make Mice More Human

In our future we will create new species out of genetic pieces of existing species. Some of these species might some day challenge us for dominion over planet Earth. Scientists have discovered a very small piece of human DNA which causes a big change in embryonic development of limbs in mice.

WALNUT CREEK, Calif.— Subtle genetic changes that confer an evolutionary advantage upon a species, such as the dexterity characteristic of the human hand, while difficult to detect and even harder to reproduce in a model system, have nevertheless generated keen interest amongst evolutionary biologists. In findings published online in the September 5 edition of the journal Science, researchers from the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and their collaborators, have uncovered a specifically human 13-nucelotide change concealed in the vast three-billion-letter landscape of the human genome. Their experiments reveal this stretch of DNA to be a recently evolved regulator of gene expression that, when introduced into a mouse embryo system, influence the molecular machinery to yield human limb and thumb development patterns.

Some argue that genetic differences between humans are inconsequential because these differences make up such a small percentage of our total genome. But that a mere 13 genetic letters could cause mouse embryonic development to go down a pathway more like human limbs testifies to the power of small genetic sequences and small genetic differences. Also, that a group of scientists could fish this 13 letter sequence out of 2.9 billion letters in an entire human genome speaks to the power modern genetic analysis informed by an understanding of evolutionary theory.

The study reinforces the conclusion that certain regions of genomes—those which are conserved across many species over evolutionary time and do not encode genes—can have a powerful regulatory influence on gene expression or the production of proteins.

These scientists are looking for the genome differences that drove the split between primates and non-primates as well as the genetic differences that make humans unique from other primates in various ways. All these differences become candidates to stick into a transgenic dog or cat of course.

"The study points to how human nucleotide substitutions can alter the regulation of genes in humans distinct from that of non-human primates, such as chimps," said one of the study's corresponding/senior authors Eddy Rubin, Director of Berkeley Lab's Genomics Division and the U.S. Department of Energy Joint Genome Institute. "This highlights a strategy that could be applied across the genome to understand at a molecular level what leads to differences between humans and non-human primates."

These big comparisons between many species are made possible by the rapid decline in DNA sequencing costs. That decline is only going to continue. So the flood of data that makes cross-species comparisons possible will only increase as will the sophistication and power of the software and computers that do the comparisons. Therefore this discovery is just the opening of a flood gate. We will see many more such discoveries in the coming months and years.

Previously published work from the Rubin lab by co-authors Shyam Prabhakar (now at the Genome Institute of Singapore), James Noonan (now at the Yale University School of Medicine), and postdoctoral fellows describes a global survey they conducted of genomes—human, chimpanzee, rhesus macaque, mouse, rat, and dog. They screened across these species to find the most conserved regions, but where humans had many more changes relative to the others. By comparing the occurrence of these features, they were seeking to home in on evidence of positive selection—sequence changes that evolve more rapidly since the human and chimp paths split six million years ago.

The ability to do comparisons across species will also turn up genetic sequences in other species that give them features and capabilities that some humans will find appealing. Look at the people who go in for heavy plastic surgery, tattooing, and drug-enhanced muscle building. Imagine what those people will do once they can put genes into themselves from other species so that they can see better at night or hear better at high frequencies. If Fido and Rover can hear a dog whistle then why can't I?

Caveat: These results are preliminary. These scientists haven't proven that this short sequence really serves a role in humans similar to what it appears to do in mice.

Using mouse embryos, Noonan and his collaborators examined how HACNS1 and its related sequences in chimpanzee and rhesus monkey regulated gene expression during development. The human sequence activated genes in the developing mouse limbs, in contrast to the chimpanzee and rhesus sequences. Most intriguing for human evolution, the human sequence drove expression at the base of the primordial thumb in the forelimb and the great toe in the hind limb. The results provided tantalizing, but researchers say preliminary, evidence that the functional changes in HACNS1 may have contributed to adaptations in the human ankle, foot, thumb and wrist-- critical advantages that underlie the evolutionary success of our species.

By Randall Parker 2008 September 07 11:44 AM  Evolutionary History
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2008 September 06 Saturday
MIT Solar Concentrator 3 Years To Market?

Technology Review takes a look at the work of MIT researcher Marc Baldo whose team has developed a way to use glass sheets to concentrate light onto the edge of the glass. This can focusing light from a larger area onto a smaller (and therefore cheaper) amount of photovoltaics material.

Unlike the mirrors and lenses in conventional solar concentrators, Baldo's glass sheets act as waveguides, channeling light in the same way that fiber-optic cables transmit optical signals over long distances. The dyes coating the surfaces of the glass absorb sunlight; different dyes can be used to absorb different wavelengths of light. Then the dyes reëmit the light into the glass, which channels it to the edges. Solar-cell strips attached to the edges absorb the light and generate electricity. The larger the surface of the glass compared with the thickness of the edges, the more the light is concentrated and, to a point, the less the power costs.

Baldo, an associate professor of electrical engineering, published his findings recently in Science. On their basis, he projects that his solar concentrators could be made big enough for the electricity they help generate to compete with electricity from fossil fuels. Indeed, says Baldo, panels equipped with the concentrators "could be the cheapest solar technology."

An earlier announcement about this research from July reports this technology might hit the market in as little as 3 years.

The researchers coated glass panels with layers of two or more light-capturing dyes. The dyes absorbed incoming light and then re-emitted the energy into the glass, which served as a conduit to channel the light to solar cells along the panels' edges. The dyes can vary from bright colors to chemicals that are mostly transparent to visible light.

Because the edges of the glass panels are so thin, far less semiconductor material is needed to collect the light energy and convert that energy into electricity.

"Solar cells generate at least ten times more power when attached to the concentrator," added Baldo.

Because the starting materials are affordable, relatively easy to scale up beyond a laboratory setting, and easy to retrofit to existing solar panels, the researchers believe the technology could find its way to the marketplace within three years.

A few of the researchers are starting a company to commercialize this technology.

Mapel, Currie and Goffri are starting a company, Covalent Solar, to develop and commercialize the new technology. Earlier this year Covalent Solar won two prizes in the MIT $100K Entrepreneurship Competition. The company placed first in the Energy category ($20,000) and won the Audience Judging Award ($10,000), voted on by all who attended the awards.

A cheap way to turn light into electricity will not immediately solve our problem with dwindling oil reserves. But add in advances to cut the costs of lithium batteries for cars and the transition away from fossil fuels will become much easier.

By Randall Parker 2008 September 06 10:20 PM  Energy Solar
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MicroRNAs In Blood Show Patterns For Cancer And Pregnancy

A group of researchers in Nanjing China have demonstrated that each type of cancer shows a unique fingerprint of types of microRNA in the blood. This opens up the possibility of cheap screening for cancer detection.

Serum microRNAs (miRNAs) can serve as biomarkers for the detection of diseases including cancer and diabetes, according to research published online this week in Cell Research. The findings pave the way for a revolutionary non-invasive diagnostic tool.

“Nowadays, almost all of the routinely used serum markers are proteins and the conventional methodologies used to measure them remain labor-intensive. No serum-based test is currently suitable for widespread use in diseases diagnosis, particularly in early tumor detection,” said Chen-Yu Zhang of School of Life Sciences, Nanjing University. “Our goal therefore was to discover a novel class of serum biomarkers for clinic uses, even for drug screening and personalized medicine.”

miRNAs are a class of naturally occurring small non-coding RNAs that have been linked with cancer development. Recent studies reporting individual miRNAs as diagnostic biomarkers of specific cancers were unable to rule out the possibility that these miRNAs appeared as a result of contamination.

Chen-Yu Zhang and colleagues are the first to comprehensively characterize entire blood miRNA profiles of healthy subjects and patients with lung cancer, colorectal cancer and diabetes, ruling out contamination. They propose that the specific serum miRNA expression profiles they identified constitute ‘fingerprints’ for cancer and disease.

But will diagnosis using microRNAs lead to cancer cures? Detection at early stage is key. Longitudinal studies that watch the same subjects from healthy starting points until disease diagnosis are probably needed in order determine whether microRNAs will allow early detection of cancer. Early stages of these studies could probably be conducted first in mice and other species with shorter lives where the time between healthy to cancerous is shorter.

Separately an Israeli group has just published a paper in Plos One where they demonstrate that circulating microRNA show distinct patterns between pregnant and non-pregnant women.

Finally, as a proof of concept, we investigated whether circulating microRNAs can be used to identify clinical conditions. It has been established that circulating maternal RNA contains placental embryonic RNA [2]. Therefore, we chose to compare the serum microRNA abundance profiles of non pregnant versus pregnant women, the latter in either their first or third trimester. We measured the serum levels of 28 microRNAs, including microRNAs reported to be placenta-specific [10], [20] as well as broadly expressed microRNAs. Box plots show relative microRNA levels in the sera of 10 non pregnant women, 10 women in the first trimester and 10 women in the third trimester (Figure 4A). The median fold changes in microRNA levels comparing third trimester pregnant women to non pregnant women are detailed in Table 1. MicroRNAs expressed equivalently across all samples were used for normalization. All of the placental microRNAs are found at higher levels in the sera from pregnant women, their levels rising with gestational age, and the levels of 12 microRNAs increased by more than 5-fold. Specifically, amounts of hsa-miR-526a and hsa-miR-527 are dramatically higher in the sera of third trimester pregnant women (elevated by more than 600 fold). Indeed, we found that the levels of three placental microRNAs (hsa-miR-526a, hsa-miR-527 and hsa-miR-520d-5p) could be used to accurately distinguish pregnant from non pregnant women (Figure 5).

This seems like a technology that could be commercialized pretty quickly. If microRNAs can detect cancers at early stages then going to the doctor a few times a year for periodic microRNA tests might replace many uses of colonoscopy, mammography, pap smears, and other early stage cancer tests.

I expect that microRNA expression patterns change with age and at different rates for different people. This might lead to more accurate ways to predict life expectancy. But will that allow extension of life expectancies? Or will it just give people a better idea of how much to save for retirement?

By Randall Parker 2008 September 06 08:14 PM  Biotech Assay Tools
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2008 September 04 Thursday
Thinking Hard Causes Overeating?

Thinking makes you hungry. So if you want to lose weight become vacuous and shallow? "Sorry I was so inconsiderate and thoughtless dear. You know my diet requires it."

Quebec City, September 4, 2008—A Université Laval research team has demonstrated that intellectual work induces a substantial increase in calorie intake. The details of this discovery, which could go some way to explaining the current obesity epidemic, are published in the most recent issue of Psychosomatic Medicine.

The research team, supervised by Dr. Angelo Tremblay, measured the spontaneous food intake of 14 students after each of three tasks: relaxing in a sitting position, reading and summarizing a text, and completing a series of memory, attention, and vigilance tests on the computer. After 45 minutes at each activity, participants were invited to eat as much as they wanted from a buffet.

The researchers had already shown that each session of intellectual work requires only three calories more than the rest period. However, despite the low energy cost of mental work, the students spontaneously consumed 203 more calories after summarizing a text and 253 more calories after the computer tests. This represents a 23.6% and 29.4 % increase, respectively, compared with the rest period.

Blood samples taken before, during, and after each session revealed that intellectual work causes much bigger fluctuations in glucose and insulin levels than rest periods. "These fluctuations may be caused by the stress of intellectual work, or also reflect a biological adaptation during glucose combustion," hypothesized Jean-Philippe Chaput, the study's main author. The body could be reacting to these fluctuations by spurring food intake in order to restore its glucose balance, the only fuel used by the brain.

"Caloric overcompensation following intellectual work, combined with the fact that we are less physically active when doing intellectual tasks, could contribute to the obesity epidemic currently observed in industrialized countries," said Mr. Chaput. "This is a factor that should not be ignored, considering that more and more people hold jobs of an intellectual nature," the researcher concluded.

Maybe the mental work uses up glucose in the brain and causes the brain cells that control appetite to sense this and drive up appetite to compensate?

By Randall Parker 2008 September 04 10:41 PM  Brain Appetite
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Orgasmic Women Walk Differently

A woman's ability to enjoy sex shows up in her gait.

Paisley, Scotland – September 04, 2008 - A new study found that trained sexologists could infer a woman's history of vaginal orgasm by observing the way she walks. The study is published in the September 2008 issue of The Journal of Sexual Medicine, the official journal of the International Society for Sexual Medicine and the International Society for the Study of Women's Sexual Health.

Led by Stuart Brody of the University of the West of Scotland in collaboration with colleagues in Belgium, the study involved 16 female Belgian university students. Subjects completed a questionnaire on their sexual behavior and were then videotaped from a distance while walking in a public place. The videotapes were rated by two professors of sexology and two research assistants trained in the functional-sexological approach to sexology, who were not aware of the women's orgasmic history.

The results showed that the appropriately trained sexologists were able to correctly infer vaginal orgasm through watching the way the women walked over 80 percent of the time. Further analysis revealed that the sum of stride length and vertebral rotation was greater for the vaginally orgasmic women. "This could reflect the free, unblocked energetic flow from the legs through the pelvis to the spine," the authors note.

There are several plausible explanations for the results shown by this study. One possibility is that a woman's anatomical features may predispose her to greater or lesser tendency to experience vaginal orgasm. According to Brody, "Blocked pelvic muscles, which might be associated with psychosexual impairments, could both impair vaginal orgasmic response and gait." In addition, vaginally orgasmic women may feel more confident about their sexuality, which might be reflected in their gait. "Such confidence might also be related to the relationship(s) that a woman has had, given the finding that specifically penile-vaginal orgasm is associated with indices of better relationship quality," the authors state. Research has linked vaginal orgasm to better mental health.

The study provides some support for assumptions of a link between muscle blocks and sexual function, according to the authors. They conclude that it may lend credibility to the idea of incorporating training in movement, breathing and muscle patterns into the treatment of sexual dysfunction.

Will training a woman in how to walk increase her sexual pleasure? Or does the different walk flow from differences in muscle and bone structure or perhaps differences in their nervous system that sexual responses? I'm going to guess that there's a big genetic component to how men and women walk.

Update: Razib uses this story to show a picture of Israeli model Bar Rafaeli. (but I'm totally turned off because she smokes - what a waste). His commenters bring up the question of the direction of flow of causality. Does having a vaginal orgasm cause a woman to walk differently? Or does the same underlying neuro-muscular system cause both the different walk and the greater ease of having vaginal orgasms? I'm guessing the latter and I'm guessing an underlying genetic cause. Ease of orgasm is probably genetically inherited.

By Randall Parker 2008 September 04 10:29 PM  Brain Sexuality
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Neighborhood Electric Vehicles Grow In Popularity

US state governments are changing regulations to allow “neighborhood ­electric vehicles” (NEVs) onto many roads.

At least 40 states have now passed laws to permit NEVs to operate on many state roads with more working on new regulations. Meanwhile, some 40,000 NEVs are operating nationwide, says the Electric-Drive Transportation Association. Kentucky and Massachusetts are considering regulations to permit low-speed vehicles (LSVs) on state roads. LSV is a federal designation that includes NEVs, and also some gas-powered vehicles.

Federal standards established for LSVs in 1998 set equipment requirements and operating standards. What separates NEVs from golf carts, for instance, includes minimum vehicle speed of 20 miles per hour and a top speed of 25 m.p.h. They must have windshield wipers, headlights, taillights, and turn signals, to name just a few differences.

State laws vary. In New Jersey, Pringle successfully lobbied the state to allow LSVs in 2004. Rhode Island and West Virginia permit them on roads posted at 25 miles per hour. Kansas allows them on roads up to 40 m.p.h. and Montana up to 45.

Some people expect the coming decline in world oil production to cause a collapse of civilization. I do not see it because I see so many ways we can cut back on energy usage while still maintaining civilized lifestyles. Scooters and small electric vehicles are two ways we can still get around while using far less energy. They aren't as comfortable or as safe as full sized cars. But they will keep us moving around.

By Randall Parker 2008 September 04 10:25 PM  Energy Transportation
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2008 September 03 Wednesday
Your Odds Of Arthritis Are Pretty High

Your odds of eventually suffering from osteoarthritis are pretty high.

ATLANTA, September 3, 2008– A landmark government study suggests nearly one in two people (46%) will develop painful knee osteoarthritis over their lifetime, with the highest risk among those who are obese. According to the Arthritis Foundation, the study underscores the immediate need for the public to understand what they can do to reduce the tremendous pain, disability and cost associated with arthritis.

Arthritis is exploding in an aging population of U.S. baby boomers. Nearly one in five U.S. adults (46 million people) has arthritis and an estimated 67 million people will be affected by 2030. Osteoarthritis, the most common type of arthritis, currently affects more than 27 million people in the U.S.

Add in rheumatoid arthritis, decaying spinal disks, and other joint problems and your odds of eventually living in pain from skeletal pains become quite high. If you aren't living in pain now you probably will eventually - barring big advances in biomedical science and biotechnology.

For these and other reasons we need rejuvenation therapies. We need stem cell therapies, gene therapies, repair nanobots, better drugs, and other therapies that will undo the damage accumulating in all our bodies.

By Randall Parker 2008 September 03 11:08 PM  Aging Studies
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Natural Selection Caused Human Male Belligerency

Just punched someone? Blame it on natural selection. What to join the Marines and go into combat? Your genes are your puppeteer. Dream of shooting down enemies? Your genetic alleles for violence are expressing themselves in your brain. We want to beat up on other people because our genes tell us to. These results come from an unverified mathematical model. But surely natural selection has made men violent. Just the mechanism of exactly how needs to get filled in.

The mathematical analysis of the evolution war by Laurent Lehmann and Prof Marc Feldman of Stanford University focused on small-scale, pre-state societies, for instance hunter-gatherers societies.

In the Proceedings of the Royal Society, Biological Sciences, the study shows that the "selective pressure" on genes linked with belligerence and bravery can be substantial even in groups of large size, so that evolution has smiled on the most aggressive and audacious group.

What I want to know: Is belligerency getting selected for or against? Does the answer to the question differ between societies?

Some guys might die in wars with the next village while still promoting their genes through their surviving relatives.

Some men who carry genetic variants that promote bravery might perish because of them, but the ones who survive may win more battles through their greater daring. The resulting opportunities for rape and pillage can create a net evolutionary benefit.

By having sex with their vanquished enemies’ wives and children, and by taking land on which their own womenfolk could grow or gather more food, particularly courageous and successful warriors would have more offspring who share their genes. “This has consequences for our understanding of the evolution of intertribal interactions, as hunter-gatherer societies are well known to have frequently raided neighbouring groups from whom they appropriated territory, goods and women,” the scientists said.

Really large scale societies that have been settled and centrally controlled for a long time (e.g. China) might have experienced long periods of selection against belligerency as the belligerent men ran afoul of central rule and got imprisoned or killed. So we might expect to find some groups to have lower frequencies of the genetic variants which cause male aggression.

Here is the abstract of the paper (PDF) and the full paper is at that link.

Tribal war occurs when a coalition of individuals use force to seize reproduction-enhancing resources, and it may have affected human evolution. Here, we develop a population-genetic model for the coevolution of costly male belligerence and bravery when war occurs between groups of individuals in a spatially subdivided population. Belligerence is assumed to increase an actor’s group probability of trying to conquer another group. An actor’s bravery is assumed to increase his group’s ability to conquer an attacked group.We show that the selective pressure on these two traits can be substantial even in groups of large size, and that they may be driven by two independent reproduction-enhancing resources: additional mates for males and additional territory (or material resources) for females. This has consequences for our understanding of the evolution of intertribal interactions, as hunter-gatherer societies are well known to have frequently raided neighbouring groups from whom they appropriated territory, goods and women.

Confirmation for genetic theorizing of this sort will not be long in coming. The costs of genetic testing have fallen by orders of magnitude in the last 10 years and the costs keep dropping. So the quantity of genetic testing is soaring. This enables large scale comparison of people for genetic and behavioral differences.

Once the genetic sources of violence become well characterized do you think the genetically most violence-prone people should be allowed to pass along their violence-causing genetic alleles to offspring?

By Randall Parker 2008 September 03 09:53 PM  Brain Evolution
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2008 September 02 Tuesday
Brain Scans Indicate When Best To Multitask

If only you could sit under an fMRI brain scanner all day the machine operator could tell you when it best to juggle lots of interrupts.

While having the study participants multitask, Leber and his colleagues at Yale University monitored their brain activity using functional magnetic resonance imaging (fMRI). The research confirmed that multitasking is, on average, inefficient. However, the brain scans allowed the researchers to predict when people would be poor multitaskers and optimal multitaskers.

There's another way to spin this result: If we could find ways to up the level of activity in certain areas of hte brain then we could multitask better.

Most dramatically, the changes in performance were preceded by changes in the participants' brain activity patterns. Higher levels of activity in brain regions such as the basal ganglia, anterior cingulate cortex, prefrontal cortex, and parietal cortex corresponded to better multitasking performance.

"What is so striking about this result is that brain activity predicted multitasking performance before participants even knew whether they would be asked to switch or repeat tasks," Leber said.

Being able to predict when people are in optimal multitasking states raises tantalizing prospects for maximizing productivity in our daily lives, according to Leber. Ideally, we should reserve task juggling for known periods of optimal multitasking while doing repetitive tasks during known periods of poor multitasking.

I would like to know what sorts of environmental influences put us in states where we are more able to multitask. Also, what do we lose in such states? Are we less able to think through a single task when in a state where our multitasking ability is improved? That is what I perceive. I get into states where I think I'm better off handling yet more interrupts once I've started getting interrupted. Getting back to the single minded focus on a single task can be hard once one starts juggling lots of things.

If you get interrupted a lot and find it hard to get back into a focused mental state then meditation might help.

Experienced Zen meditators can clear their minds of distractions more quickly than novices, according to a new brain imaging study.

After being interrupted by a word-recognition task, experienced meditators' brains returned faster to their pre-interruption condition, researchers at Emory University School of Medicine found.

The results will be published online by the journal Public Library of Science One (PLoS ONE). http://dx.plos.org/10.1371/journal.pone.0003083

By Randall Parker 2008 September 02 11:27 PM  Brain Performance
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Ruthless Gene Test For Marital Happiness.

The gene AVPR1a codes for the arginine vasopressin receptor 1A which influences altruism, monogamy, and other behaviors. Genesis Biolabs wants you to test your prospective spouse for versions of AVPR1a to discover if he or she will be altruistic toward you. But what if a woman wants a man who will be ruthless in his pursuit of higher positions in a corporation?

Screening for the "ruthlessness" gene is likely an indicator of marital happiness. Marriages born out of mutual respect and mutual interest rather than self-interest are much more likely to succeed and probably less likely to end in divorce. Is your fiancé just after your money? Those with the "ruthlessness" gene may very well be. Those with the altruistic version of AVPR1a probably aren't. Ruthless people will lie, cheat and steal to get what they want. Genetics may not be a guaranteed indicator of human behavior and motivation [genetics is only one half of the nature vs. nurture debate] but genes don't lie. Before you make a lifetime commitment, have your fiancé tested.

What if an ambitious high status man wants a woman who will give his offspring genes that will make his kids hard chargers and ruthlessly ambitious? People could easily use this test for reasons opposite of the marketing pitch for it.

The research that led to this test came out only 9 months ago. In a few years we'll know of dozens of genes that influence fidelity, ruthlessness, and assorted other characteristics relevant to

Jerusalem, December 6, 2007 – Are those inclined towards generosity genetically programmed to behave that way? A team of researchers, including Dr. Ariel Knafo of the Psychology Department at the Hebrew University of Jerusalem, believes that this could very well be the case.

Through an online task involving making a choice whether or not to give away money, the researchers found that those who chose to give away some or all of their money differed genetically from those involved in the exercise who chose not to give their money away.

The scientists conducted the experiment with 203 online "players". Each player could choose to keep the equivalent of $12 he was allocated, or to give all or part of it to an anonymous other player.

Those involved also provided DNA samples which were analyzed and compared to their reactions. It was found that those who had certain variants of a gene called AVPR1a gave on average nearly 50 percent more money than those not displaying that variant. The results of the study were published online recently in the research journal Genes, Brain and Behavior.

Do you want your wife giving all your hard-earned money away to charity? Do you want your husband to be an easy mark when his loser brother comes begging for money? I expect scientists will find genetic variations that contribute toward selective altruism for offspring and other genetically very close relatives. Maybe a woman will prefer a husband who is genetically more inclined to sacrifice for the kids and not for strangers.

New research from the Karolinska Institutet in Sweden suggests AVPR1a influences stability of human relationships.

Hasse Walum and his colleagues made use of data from The Twin and Offspring Study in Sweden, which includes over 550 twins and their partners or spouses. The gene under study codes for one of the receptors for vasopressin, a hormone found in the brains of most mammals. The team found that men who carry one or two copies of a variant of this gene -- allele 334 -- often behave differently in relationships than men who lack this gene variant.

The incidence of allele 334 was statistically linked to how strong a bond a man felt he had with his partner. Men who had two copies of allele 334 were also twice as likely to have had a marital or relational crisis in the past year than those who lacked the gene variant. There was also a correlation between the mens gene variant and what their respective partners thought about their relationship.

Among the tested Swedish males 40% had at least one copy of the genetic variant that seems to decrease relationship stability.

Might such a simple switch be found in humans? A team led by Hasse Walum of the Karolinska Institute in Stockholm, Sweden, sequenced the AVPR1a gene in about 500 pairs of adult same-sex Swedish twins, all of them married or cohabiting for at least 5 years, and their partners. One variation of the gene was particularly common; about 40% of males had either one or two copies of a version--or allele--of the gene known as "334."

These results are not surprising. A previous twins study found a genetic influence on the rate of female infidelity. Also, another twins study found evidence of a genetic contribution to psychopathy. We are going to see a big stream of discoveries which will make romantically motivated genetically testing become desirable. Genetic tests will yield such valuable insights into future behavor that I expect genetic privacy to become indefensible. People will surreptitiously take genetic samples and get tests done on the genes of their dates and lovers.

All this genetic testing will change who manages to get a mate and reproduce. Even among those who reproduce the testing will change who will reproduce with who. I expect we will see more mating of like with like. The most monogamously inclined will seek out others of their kind for marriage and babies. So societies will divide more deeply between those with stable marriages and those who engage in serial monogamy and promiscuity.

Update: More details on the study about avpr1a gene connection with marital happiness.

"A study by Erica Spotts, National Institute on Aging, using this sample was one of the first to show genetic influences on marital relationships, but did not reveal which genes were involved," says Neiderhiser. "The work on pair bonding in voles was very exciting because it suggested to us a specific gene to examine."

Neiderhiser, Paul Lichtenstein, the Karolinska Institute in Sweden, and colleagues interviewed 2,186 adults taking part in the Twin and Offspring Study in Sweden (TOSS). The TOSS study collected detailed information from pairs of twins and their partners or spouses about their marital relationships, personality and mental health, as well as genetic data.

They report in this week's on-line issue of the Proceedings of the National Academy of Sciences that, in men, having allele 334 was inversely linked to measures of the strength of a person's bond to their mate. They also report that men who carried two copies of allele 334 were more than twice as likely to report serious marital or relationship problems, such as facing threat of divorce, as men who had did not carry it. These men also were almost twice as likely to be unmarried as men with no copies, despite having a long-term relationship with their mate.

Women married to men with one or two copies of allele 334 reported lower scores on measures of marital quality than women married to men not carrying this allele.

Allele 334 is also associated with increased activity in the amygdala, a brain region involved in regulating emotions.

By Randall Parker 2008 September 02 09:55 PM  Bioethics Reproduction
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2008 September 01 Monday
Fish Oil Better Than Statin For Chronic Heart Failure

Omega 3 fatty acids work better than a popular statin to extend life of those already diagnosed with an enlarged failing heart.

In the group of patients taking the fish oil pills, 1,981 died of heart failure or were admitted to the hospital with the problem. In the patients on placebo pills, 2,053 died or were admitted to the hospital for heart failure.

In a parallel study, the same team of Italian doctors gave 2,285 patients the drug rosuvastatin, also known as Crestor, and gave placebo pills to 2,289 people. Patients were then tracked for about four years. The doctors found little difference in heart failure rates between the two groups.

This is not an argument against taking statins to lower cholesterol. A cholesterol lowering drug can prevent artery clogging that will eventually cause cardiovascular failure. But once the damage has already reached a critical phase statins basically come too late to make much difference.

I see this result as more evidence that the type of fat you eat is probably more important than the amount of fat you eat.

Heart disease is not the only degenerative disease whose progress you can slow or stop once you have it. A vitamin supplement formula including omega 3 fatty acids appears to slow or stop the progress of atrophic (dry) age-related macular degeneration (AMD). Other diseases such as insulin resistant diabetes can be made less bad by diet. But better to improve the diet decades before you become old enough to be at risk for these degenerative diseases of old age.

Update: A new study finds that higher dietary omega 3 fatty acids the most likely cause of lower heart disease risk in Japan.

If you're fishing for ways to reduce the risk of heart disease, you might start with the seafood-rich diet typically served up in Japan. According to new research, a lifetime of eating tuna, sardines, salmon and other fish appears to protect Japanese men against clogged arteries, despite other cardiovascular risk factors.

The research, published in the August 5, 2008, issue of Journal of the American College of Cardiology (JACC), suggests that the protection comes from omega-3 fatty acids found in abundance in oily fish. In the first international study of its kind, researchers found that compared to middle-aged white men or Japanese-American men living in the United States, Japanese men living in Japan had twice the blood levels of omega-3 fatty acids—a finding that was independently linked to low levels of atherosclerosis.

"The death rate from coronary heart disease in Japan has always been puzzlingly low," said Akira Sekikawa, M.D., Ph.D, an assistant professor of epidemiology at the University of Pittsburgh, PA, and an adjunct associate professor at Shiga University of Medical Science, Otsu, Japan. "Our study suggests that the very low rates of coronary heart disease among Japanese living in Japan may be due to their lifelong high consumption of fish."

Click thru to read all the details of how the researchers came to this conclusion. Or just start eating fish or taking DHA/EPA capsules.

Update: Still not ready to change your diet? Also remember my recent post Fish Reduce Aging Brain Lesions.

Update II: If you want to be hungry like a wolf then eat salmon.

Wolves are not quite the red-blooded hunters we thought they were. It appears they prefer to dine on a nice piece of salmon rather than deer.

By Randall Parker 2008 September 01 07:22 PM  Aging Diet Heart Studies
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