2007 July 31 Tuesday
Gene Increases Emotional Memory Recall

A genetic variant of a neuron adrenergic receptor that binds neurotransmitter noradrenaline boosts recall of emotionally intense memories.

People with a particular gene variant are better at remembering emotionally laden memories than people with the more common version of the gene, research shows. The gene, called ADRA2B, is involved in detecting brain chemicals related to emotional arousal.

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The research highlighted the effect of the gene in stark terms: survivors of the 1994 Rwandan genocide were more likely to harbour persistent memories of the conflict if they had the variant version of the gene. The variant is present in 12% of people of African ancestry and in 30% of Causasians.

The researchers showed Swiss and Rwandan experimental subjects pictures with neutral, emotionally negative, and emotionally positive content. Later they had the subjects write down memories of what they saw in the pictures. The Rwandans were refugees living in Uganda who had seen some terrible things in the intertribal kill-fests in Rwanda.

While more Europeans carry the genetic variant that enhances emotionally laden memory recall the Rwandans who had that genetic variant had better recall of negative emotional events.

The researchers found that, in both groups, people carrying the ADRA2B gene variant were "substantially more likely" to remember both positive and negative pictures than people with other forms of the gene. Neutral images were recalled to the same degree by people with and without the variant.

However, Rwandans with the variant had far higher recall of negative emotional events than the Europeans who carried it – and this was unrelated to whether or not they suffered from post traumatic stress disorder.

The Rwandans might have some other genetic variants that work synergistically with ADRB2B to enhance negative memory recall.

Think about the implications. Groups differ in their average tendency to remember bad memories. Does that make some groups and some individuals more likely to hold grudges, seek revenge, and dwell on past events? Do people who better remember bad and good events try harder to set themselves up for repeats of great past events and to avoid repeats of terrible past events? Does this create different cultures in different parts of the world?

As gene testing costs go down by orders of magnitude we are going to see a flood of reports of genetic variations that influence cognitive function in a large variety of ways. The amount of human behavior ascribed to free will is going to shrink. The amount ascribed to current environmental influences will shrink as well.

By Randall Parker 2007 July 31 05:32 PM  Brain Genetics
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2007 July 30 Monday
Hot Earth Keeps American Cities Above Sea Level

Think you stand on solid ground? Not so. Cooling down in Earth's core would sink most American cities under water.

A University of Utah study shows how various regions of North America are kept afloat by heat within Earth’s rocky crust, and how much of the continent would sink beneath sea level if not for heat that makes rock buoyant.

Of coastal cities, New York City would sit 1,427 feet under the Atlantic, Boston would be 1,823 feet deep, Miami would reside 2,410 feet undersea, New Orleans would be 2,416 underwater and Los Angeles would rest 3,756 feet beneath the Pacific.

Mile-high Denver’s elevation would be 727 feet below sea level and Salt Lake City, now about 4,220 feet, would sit beneath 1,293 feet of water. But high-elevation areas of the Rocky Mountains between Salt Lake and Denver would remain dry land.

“If you subtracted the heat that keeps North American elevations high, most of the continent would be below sea level, except the high Rocky Mountains, the Sierra Nevada and the Pacific Northwest west of the Cascade Range,” says study co-author Derrick Hasterok, a University of Utah doctoral student in geology and geophysics.

“We have shown for the first time that temperature differences within the Earth’s crust and upper mantle explain about half of the elevation of any given place in North America,” with most of the rest due to differences in what the rocks are made of, says the other co-author, David Chapman, a professor of geology and geophysics, and dean of the University of Utah Graduate School.

Will cooling of the Earth's core progress enough to some day sink lots of cities before the Sun expands and cooks away the oceans?

By Randall Parker 2007 July 30 11:14 PM  Trends Geology
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2007 July 29 Sunday
Humanitarians Do Not Like Slackers Either

Christina Fong at Carnegie Mellon University finds that people who have stronger humanitarian impulses are just as reluctant to donate to the lazy poor as are those who score lower on humanitarianism.

The study by Christina Fong, a research scientist in the Department of Social and Decision Sciences at Carnegie Mellon, supports previous findings that people are more likely to give money to the poor when they believe that poverty is a result of misfortune rather than laziness. What's surprising is that this effect is largest among people who claim to have more humanitarian or egalitarian beliefs. In fact, humanitarians give no more than others when recipients are deemed to be poor because of laziness.

Nobody likes slackers (except for mutual protection slacker leagues I have run into in work places). So why do opinions about the welfare state vary? I can think of a few reasons:

  • People differ in their judgments on whether most poor people are poor due to laziness or factors not under their control.
  • People differ in how much empathy they feel for perceived suffering of others. When I say "empathy" read that as "pain". Attempts to help others are, to some extent, an attempt to relieve the pain one feels at the sight of their suffering.
  • Not everyone will look at the same living conditions and agree on which circumstances constitute actual suffering.
  • People differ in how much moral hazard (in terms of less responsible behavior on the part of those helped) they think comes from helping others. The risk of reducing incentives to avoid and emerge from poverty cause many to see some degree of suffering as necessary to motivate both actual and potential poor people. Judgments differ both on how much such motivation is necessary and about which conditions constitute enough motivation to avoid the moral hazard side effects that come from helping poor people.
  • Some see helping others as beneficial also as a universally needed expression of love.

A welfare state can only work well if the overwhelming majority feel strongly motivated to work and to avoid risks. Otherwise the accumulating moral hazard side effects become an unfair burden on those who are more productive and social pathologies grow in frequency. More from this study's press release:

Fong conducted an experiment in which subjects were given $10 and asked to decide how much, if any, to give to a real-life welfare recipient. A few days prior to the experiment, participants completed surveys about their values and beliefs, including beliefs about whether lack of effort or bad luck cause poverty. The survey also included questions designed to measure whether participants considered themselves to be humanitarians.

During the experiment, donors were randomly matched with three different welfare recipients with varying work histories and desires for full-time work. This information, combined with the participants' individual beliefs about the causes of poverty, had a major impact on giving. People who believed that their recipient was poor because of bad luck gave six and a half times as much as people who believed that their recipient was poor because of laziness.

Those who scored high on the humanitarian measure gave more money to recipients judged to be victims of bad luck than those who scored low - but the two groups made the same offers to welfare recipients judged to be lazy. Fong terms this desire to help people on the condition that they appear to deserve it "empathetic responsiveness."

Will advances in scientific understanding of human brains cause people to become more or less supportive of the welfare state? I see several factors to consider in attempting to answer this question:

  • We will be able to identify health impairments much more accurately. Got chronic fatigue syndrome? Eventually we'll have much better ways to ascertain that a person really does have CFS or chronic pain or some other claimed ailment or injury.
  • Intellectual abilities will be easier to measure. Is a person really too dumb to be productive enough to earn a decent wage? Does someone have some other mental impairment? We will know.
  • People with organically caused motivational problems will be easier to separate out from those who just want to be parasites.
  • Under which environmental conditions do people with a given type of mental limitation or disability cease to be able to cope and economically support themselves?
  • Will we be able to predict from genetic profiles who will produce children who can't cope with modern society?

But the use of more accurate scientific knowledge does not lead automatically to correct answers. Take, for example, obsessive compulsive and addictive behaviors. Even if we can know that a particular person feels a huge compulsion to gamble that does not mean we should necessarily subsidize them. The size of the compulsion might even argue for forcing them to endure greater suffering so that the size of the pain becomes large enough to outweigh the urge to gamble.

We aren't just going to gain greater knowledge of how the brain works and why people act the way they do. Suppose we can discover why, say, some people have behavioral problems that get them fired from jobs or prevent them from looking for work. Then suppose scientists come up with effective treatments to change that group of mentally dysfunctional people to make them capable of supporting themselves. Once those treatments become available would you be willing to tell some group of welfare recipients that they can get treatments (e.g. neural stem cells or neural gene therapy) for their conditions at taxpayer expense but can't get welfare payments any more?

By Randall Parker 2007 July 29 07:57 PM  Brain Economics
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HCCI Improves Gasoline Engine Efficiency

MIT researchers are figuring out how to allow conventional 4 stroke gasoline engines to shift into a sparkless mode similar to diesel engine operation.

Many researchers are studying a new way of operating an internal combustion engine known as "homogeneous charge compression ignition" (HCCI). Switching a spark-ignition (SI) engine to HCCI mode pushes up its fuel efficiency.

In an HCCI engine, fuel and air are mixed together and injected into the cylinder. The piston compresses the mixture until spontaneous combustion occurs. The engine thus combines fuel-and-air premixing (as in an SI engine) with spontaneous ignition (as in a diesel engine). The result is the HCCI's distinctive feature: combustion occurs simultaneously at many locations throughout the combustion chamber.

One of HCCI's big advantages over diesel is the ability to avoid oxidation of nitrogen.

That behavior has advantages. In both SI and diesel engines, the fuel must burn hot to ensure that the flame spreads rapidly through the combustion chamber before a new "charge" enters. In an HCCI engine, there is no need for a quickly spreading flame because combustion occurs throughout the combustion chamber. As a result, combustion temperatures can be lower, so emissions of nitrogen pollutants are negligible. The fuel is spread in low concentrations throughout the cylinder, so the soot emissions from fuel-rich regions in diesels are not present.

Perhaps most important, the HCCI engine is not locked into having just enough air to burn the available fuel, as is the SI engine. When the fuel coming into an SI engine is reduced to cut power, the incoming air must also be constrained--a major source of wasted energy.

This design would boost fuel efficiency by a few miles per gallon.

The researchers estimate that the increase in fuel efficiency would be a few miles per gallon. "That may not seem like an impressive improvement," said Green. "But if all the cars in the US today improved that much, it might be worth a million barrels of oil per day--and that's a lot."

The HCCI mode might eventually provide a bigger fuel efficiency boost. Engines can only run in HCCI mode in a midrange of RPMs. At first glance that limits the efficiency gain possible from HCCI. However, marrying an HCCI-capable engine to hybrid electric components might provide a way to allow an engine to work in HCCI mode more of the time that it is running. At what would otherwise be lower RPM operation periods a car could get propelled by electric motors powered by the battery. Then the engine could get started up and put directly into HCCI mode to provide power to the car at higher speed and to charge the batteries. A car with sufficiently powerful batteries and electric motors could use the gasoline engine only to charge the batteries and to supply power to the electric motors. That could allow the engine to run at a constant and HCCI-capable RPM.

Ford is funding this research just as it is funding other MIT research on ethanol turbo injection to boost gasoline engine efficiency.

This research was supported by Ford Motor Company and the Ford-MIT Alliance, with additional support from BP.

Ford's executives think they can achieve near-diesel efficiency with gasoline engines and do so more cheaply. So Ford is not following the German makers in embracing diesel for passenger cars. My guess is that the Ford folks are correct.

We need all the efficiency improvements that can get squeezed out of internal combustion engines to complement advances made in battery technology. Out of the two I'm more worried about the speed of advance of the battery technology.

Update: A couple of months ago AutoblogGreen interviewed Dr. Gary Smyth, director of powertrain research at GM, about GM's research on engines and Smyth provided a look at why HCCI is better and what problems must be solved to make HCCI workable.

GS: Well, first of all it's a homogeneous charge compression ignition. So what it really is what I would call the next generation combustion process. So it's not a technology, it's really the process, it's the combustion process that we're developing and it really is, think of it as clean, efficient combustion. Like the two-stroke, the two-stroke by the way ran very lean and by the way we could run HCCI on the old two-strokes, we're not doing the same with the four-stroke where we are running the engine extremely lean and we're not using a spark plug, it's the whole combustion process is what we call kinetically controlled. It depends on the air fuel mixture in the cylinder. So, we're now controlling the combustion without a spark plug. We're running extremely lean and we need a number of enabling technologies to help us control the combustion. One is direct injection. The other is very wide-authority cam phasing. The other is very precise control. Another one is significant residuals or exhaust recirculation gases that we would take into the cylinder. So, much more complex from an engine perspective but allows us to really get the upper bound fuel economy potential of the four-stroke engine and do that with very low emissions.

The interviewer and Smyth both know engine technologies. The whole interview is very interested and delves into other approaches for boosting internal combustion engine efficiency.

By Randall Parker 2007 July 29 02:39 PM  Energy Transportation
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Gestures Improve Memory Retention

Gesticulate to learn more.

Kids asked to physically gesture at math problems are nearly three times more likely than non-gesturers to remember what they’ve learned. In today’s issue of the journal Cognition, a University of Rochester scientist suggests it’s possible to help children learn difficult concepts by providing gestures as an additional and potent avenue for taking in information.

“We’ve known for a while that we use gestures to add information to a conversation even when we’re not entirely clear how that information relates to what we’re saying,” says Susan Wagner Cook, lead author and postdoctoral fellow at the University. “We asked if the reverse could be true; if actively employing gestures when learning helps retain new information.”

It turned out to have a more dramatic effect than Cook expected. In her study, 90 percent of students who had learned algebraic concepts using gestures remembered them three weeks later. Only 33 percent of speech-only students who had learned the concept during instruction later retained the lesson. And perhaps most astonishing of all, 90 percent of students who had learned by gesture alone—no speech at all—recalled what they’d been taught.

I find that both saying what I learn and writing what I learn helps to retain the concepts and information better. Also, getting questioned about recently learned information increases retention.

By Randall Parker 2007 July 29 11:24 AM  Brain Performance
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Thin Nanosheet Strong As Plexiglass

Fun with nanotechnology.

Tightly packed molecules lend unexpected strength to nanothin sheet of material

Scientists at the University of Chicago and Argonne National Laboratory have discovered the surprising strength of a sheet of nanoparticles that measures just 50 atoms in thickness.

“It’s an amazing little marvel,” said Heinrich Jaeger, Professor in Physics at the University of Chicago. “This is not a very fragile layer, but rather a robust, resilient membrane.”

Even when suspended over a tiny hole and poked with an ultrafine tip, the membrane boasts the equivalent strength of an ultrathin sheet of plexiglass that maintains its structural integrity at relatively high temperatures.

“When we first realized that they can be suspended freely in air, it truly surprised all of us,” said Xiao-Min Lin, a physicist at Argonne’s Center for Nanoscale Materials.

They used gold particles separated by organic (probably meaning carbon-based) nanoparticles.

The experimental material consisted of gold particles separated by organic “bumpers” to keep them from coming into direct contact. The research team suspended this array of nanoparticles in a solution, then spread the solution across a small chip of silicon, a popular semiconductor material. When the solution dried, it left behind a blanket of nanoparticles that drape themselves over holes in the chip, each hole measuring hundreds of nanoparticles in diameter. Then the researchers probed the strength of the freely suspended nanoparticle layer by poking it with the tip of an atomic force microscope.

...

The research team also found that the material held together when heated until reaching temperatures of 210 degrees and beyond.

What I wonder: Will nanomaterials made from more plentiful elements perform just as well at many tasks as rarer elements which we will run out of? How much will nanotech allow us to develop substitutes for rarer elements? Once we develop renewable substitutes for fossil fuels will we suffer shortages of anything besides land?

By Randall Parker 2007 July 29 08:33 AM  Nanotech Materials
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2007 July 28 Saturday
Diesel Particulates Plus Cholesterol Equals Inflammation

Diesel particulate pollution works synergistically with cholesterol to increase gene expression for genes involved in inflammation.

Got high cholesterol? You might want to stay away from air pollution.

That's the message of a new UCLA study linking diesel exhaust to atherosclerosis, or hardening of the arteries, which significantly increases one's risk for heart attack and stroke. Published in the July 26 edition of the online journal Genome Biology, the findings are the first to explain how fine particles in air pollution conspire with artery-clogging fats to switch on the genes that cause blood vessel inflammation and lead to cardiovascular disease.

"When you add one plus one, it normally totals two," said principal investigator Dr. André Nel, chief of nanomedicine at the David Geffen School of Medicine at UCLA and a researcher at UCLA's California NanoSystems Institute. "But we found that adding diesel particles to cholesterol fats equals three. Their combination creates a dangerous synergy that wreaks cardiovascular havoc far beyond what's caused by the diesel or cholesterol alone."

At the moment a battle is raging in Sacramento about a regulatory change to require construction companies and other operators of off-road diesel equipment to gradually upgrade or retire diesels that emit lots of particulates and other pollutants. The emissions restrictions for diesel cars are much tougher than the restrictions for off-road equipment. Well, diesel pollutants really are bad for human health and the polluters have been allowed to pollute for far too long.

Cells from human blood vessels were exposed to diesel particulates and

"Diesel particles are coated in chemicals containing free radicals, and the fatty acids in LDL cholesterol generate free radicals during metabolism in the cells," said first author Ke Wei Gong, a UCLA cardiology researcher. "We wanted to measure what happens when these two sources of oxidation come into contact."

The scientists combined the pollutants and oxidized fats and cultured them with cells from the inner lining of human blood vessels. A few hours later, the team extracted DNA from the cells for genetic analysis.

"We saw that the diesel particles and oxidized fats had worked in tandem to activate the genes that promote cellular inflammation — a major risk factor for atherosclerosis," said Dr. Jesus Araujo, UCLA assistant professor of medicine and director of environmental cardiology at the Geffen School of Medicine.

"The interaction left a genetic footprint that reveals how interaction between the particles and cholesterol accelerates the narrowing and blockage of the blood vessels," Araujo noted.

Now you might be saying that cell culture studies often do not reflect what happens in whole organisms. True enough. But these scientists saw similar gene expression changes when they repeated the experiment with live mice.

To duplicate these findings in living cells, the UCLA team exposed mice with high cholesterol to the diesel particles and saw activation of some of the same gene groups in the animals' tissue.

Do not live near highways. Do not live in areas with high levels of air pollution. If you must then consider installing a particulate air filter.

By Randall Parker 2007 July 28 09:30 PM  Health Pollution Harm
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Heroic Wolves Save Glorious Aspens From Evil Elks

No, I'm not talking about the people and buildings in Aspen Colorado. Aspen Colorado's roads and buildings exist instead of trees after all. I'm talking about how wolves play a more clearly beneficial role than the Smokey the Bear cartoon in allowing forests to grow. (by "more clearly" I'm referring to how the US Forest Service prevents smaller fires and therefore causes bigger fires that are far more damaging to trees)

CORVALLIS, Ore. – The wolves are back, and for the first time in more than 50 years, young aspen trees are growing again in the northern range of Yellowstone National Park.

The wolves serve as a deterrent force based on fear who protect the Aspens from the ravenous tree eaters.

The findings of a new study, just published in Biological Conservation, show that a process called “the ecology of fear” is at work, a balance has been restored to an important natural ecosystem, and aspen trees are surviving elk browsing for the first time in decades.

The research, done by forestry researchers at Oregon State University, supports theories about “trophic cascades” of ecological damage that can be caused when key predators – in this case, wolves – are removed from an ecosystem, and show that recovery is possible when the predators are returned. The results are especially encouraging for the health of America’s first national park, but may also have implications for other areas of the West and other important predators.

After an absence of 70 years, wolves were re-introduced to Yellowstone Park in 1995, and elk populations began a steady decline, cut in half over the past decade. Also, the presence of a natural predator appears to have altered the behavior of the remaining elk, which in their fear of wolves tend to avoid browsing in certain areas where they feel most vulnerable. The two factors together have caused a significant reduction in elk browsing on young aspen shoots, allowing them to survive to heights where some are now above the animal browsing level.

I'm thinking any gains the Aspen trees make in Yellowstone thanks to the wolves will be eventually swamped by the development of cellulosic technology that turns trees into edible food for ravenous SUVs, motorhomes, and other vehicles. The vehicles will eat into the tree population on a far larger scale than the elks can manage to do.

So here's this relative of the dog, not as smart and as sentient as humans, who does far more for the environment than any ten thousand sentient humans. Plus, this species puts out a pretty cool night time howl that few if any humans can beat.

Evil plant eaters kill off saplings years before they have a chance to reach their full potential. Great meat-eating wolves create the ecological room that trees need to establish themselves. Morally virtuous carnivores stop the evil vegetarians from damaging the environment.

“This is really exciting, and it’s great news for Yellowstone,” said William Ripple, a professor in the OSU College of Forestry. “We’ve seen some recovery of willows and cottonwood, but this is the first time we can document significant aspen growth, a tree species in decline all over the West. We’ve waited a long time to see this, but now we’re optimistic that things may be on the right track.”

The study found significant numbers of aspen, especially in streamside “riparian” zones, that have grown from tiny shoots in the past decade to heights of more than seven feet – a key point in their long-term survival, placing their crowns above the height easily browsed by elk and other animals. Tree growth in some stands has been particularly apparent just in the past 4-5 years.

What I wonder: what ecological changes have we unknowingly caused by cutting the population of grizzly bears down by two orders of magnitude in the lower 48 states?

In the early 1800s, 50,000 to 100,000 grizzly bears ranged over North America west of the Mississippi River. By 1900, only small, scattered populations remained. The U.S. Fish and Wildlife Service listed the grizzly as a threatened species in 1975, estimating that fewer than 1,000 bears remained in a few pockets of Yellowstone National Park and along the Canadian border.

As human populations continue to grow our ability to create suitable habitats for many big animal species will continue to dwindle.

What I also wonder: Will genetic engineering eventually lead to the emergence of highly intelligent post-human species which will rebalance the world's ecology by serving as predators of the currently reining smartest species? Will the new post-humans serve as cunning Hannibal Lecters who enjoy hunting and killing homo sapiens? After all, lions and tigers feel no remorse for their killings. Surely the development of post-humans who enjoy hunting sentient beings will become technologically feasible.

By Randall Parker 2007 July 28 01:25 PM  Trends Ecology
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2007 July 27 Friday
Better Connected Brains More Resistant To Peer Pressure?

Is susceptibility to peer pressure identifiable in adolescents using brain scans? ("but mom, my weak brain connections made it impossible for me to say no")

WASHINGTON, DC July 26, 2007 – Brain regions that regulate different aspects of behavior are more interconnected in children with high resistance to peer influence than those with low resistance, according to a new study published in the July 25 issue of The Journal of Neuroscience.

"These findings may help develop more effective strategies to prevent the development of lifestyles of violence and crime,” says John Sweeney, PhD, Director of the Center for Cognitive Medicine at the University of Illinois at Chicago. Sweeney was not involved in this study.

In the new study, Tomas Paus, MD, PhD, at the University of Nottingham, and his colleagues used functional neuroimaging to scan adolescents while they watched video clips of neutral or angry hand and face movements. Previous research has shown that anger is the most easily recognized emotion.

Paus and his team observed 35 10-year-olds with high and low resistance to peer influence, as determined by a questionnaire. The researchers then showed the children video clips of angry hand movements and angry faces and measured their brain activity. They found that the brains of all children showed activity in regions important for planning and extracting information about social cues from movement, but the connectivity between these regions was stronger in children who were marked as less vulnerable to peer influence. These children were also found to have more activity in the prefrontal cortex, an area important for decision making and inhibition of socially inappropriate behavior.

Do stronger connections between these brain regions form as these children with weaker connections get older? Or perhaps do they remain more susceptible to peer pressure?

By Randall Parker 2007 July 27 12:03 AM  Brain Development
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2007 July 26 Thursday
Marijuana Users At Greater Risk Of Psychotic Problems

A meta-analysis of 35 longitudinal studies finds more schizophrenia and other psychotic illnesses among past and current users of reefer. (making the term "reefer madness" prophetic)

Cannabis users are 40% more likely than non-users to suffer a psychotic illness such as schizophrenia, say UK experts.

Writing in the Lancet, a team led by Dr Stanley Zammit from Bristol and Cardiff Universities said young people needed to be made aware of the dangers.

Beware the demon weed. Or as Mr. Mackey would say, "Mari-joowanna is bad, mmmkay?".

More frequent users had a higher incidence of problems.

Zammit and his colleagues combined data from 35 longitudinal trials, in which populations are observed over time. They found that, even after allowing for other factors, such as other substance use and intelligence, people who have taken cannabis are 41% more likely to develop schizophrenia or other psychotic problems than those who have never used it. Those who used cannabis most frequently were more than twice as likely to suffer problems.

It was less clear whether cannabis use was also linked to depression, suicidal thoughts or anxiety.

What I want to know: Are tokers fatter than the average person?

By Randall Parker 2007 July 26 11:56 PM  Brain Addiction
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Fish Oils Reduce Inflaming Compounds

The presence of fish oils reduces the conversion of vegetable oils into inflammation-causing prostanoids.

Scientists have provided new evidence that using more fish oil than vegetable oil in the diet decreases the formation of chemicals called prostanoids, which, when produced in excess, increase inflammation in various tissues and organs. The results, by William L. Smith, Professor and Chair of Biological Chemistry at the University of Michigan, Ann Arbor, and colleagues, may help in designing new anti-inflammatory drugs with fewer side effects than the ones currently available.

“Prostanoids help control blood pressure, fight allergies, and modulate inflammation, but too much of them – especially those made from vegetable oils – can also lead to increased pain, swelling, and redness in various tissues,” Smith says. “Our study shows that prostanoids made from fish oil are less effective at causing pain and swelling than those made from vegetable oil and that adding fish oil to the diet decreases the amount of prostanoids made from vegetable oil.”

Increased expression of genes involved in inflammation is one of the characteristics of aging tissues. Reducing the extent of this age-related inflammation will probably yield health dividends.

The experiments were done with cell cultures.

Smith and colleagues looked at the mutual effects of both oils by changing their respective amounts in cultured cells. As expected, a relative increase in fish oil lowered the amount of prostanoids from vegetable oil, although not always in the expected proportions.

Both fish and vegetable oils are converted into prostanoids through chemical reactions that are aided by enzymes called cyclo-oxygenases (COX), two types of which – COX-1 and COX-2 – are involved in the reactions. The scientists showed that, in reactions involving COX-1, when more fish oil is present, it preferentially binds to COX-1, thus limiting vegetable oil’s access to this enzyme. But in reactions involving COX-2, increasing the amount of fish oil did not change the way it binds to COX-2, so a significant portion of vegetable oil was still converted to prostanoids.

Eat more fish oils to get more omega 3 fatty acids. Also, eat less corn oil and other oils which have more omega 6 fatty acids.

By Randall Parker 2007 July 26 11:29 PM  Aging Diet Studies
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Robert Rapier: Our Future Should Be Electric

Over at The Oil Drum Robert Rapier argues biomass energy has a very limited role to play as compared to solar photovoltaics.

The fundamental problem here is that photosynthesis is not very efficient. Consider the rapeseed oil yield above. Gilgamesh made a table that is basically the solar capture/conversion to oil from various crops. The gist is that only a few hundredths of a percent of the incoming solar energy gets converted into liquid fuels. Of course some did get converted into other biomass, which could be otherwise used for energy, but generally we get a very low capture of the sun's energy for use as liquid fuels. (This exercise can still be proven by assuming the theoretical limit for photosynthesis. One must just make more assumptions and it is not as easy to follow for a general audience).

Consider instead direct solar capture. Let's not even consider the record 40+% efficiency that Spectrolab announced last year. Let's not consider any of the more exotic technologies that are pushing the envelope on direct solar capture efficiency. BP's run of the mill silicon solar cells operate with an efficiency of 15%. That's about 250 times better than the solar to rapeseed oil route. Or, to put it a different way, you can produce the same amount of energy with direct solar capture in a 13 ft. by 13 ft. area that you can by photosynthesis in 1 acre of rapeseed. And odds are that you have a roof with an area that size, which could be used to capture energy without the need to use arable land.

Rapier has reached the same conclusion I've preached for years: We need to develop the technology we need to shift to electric power for transportation.

Of course the disadvantages are 1). The costs for solar are still relatively high; and 2). We have a liquid fuel infrastructure. But in the long run, I don't see that we have any chance of maintaining that infrastructure. If we are to embark on a Manhattan Project to get off of our petroleum dependence, we should direct our efforts toward an eventual electric transportation infrastructure.

Biomass energy will eat up too much land and agriculture will generate too much pollution with a poor ratio of Energy Return On Energy Invested (EROEI). Synthetically created photovoltaic materials will convert sunlight to energy far more efficiently than plants can manage. This fact might one day enable nanobots to outcompete DNA-based life. But for the foreseeable future the use of photovoltaics instead of biomass energy will protect nature.

Airplanes probably aren't going escape their use of liquid fuels when cars shift to electric power. So the relative cost of air transportation will rise vis a vis ground transportation. But overall the cost of transportation will fall once we can power vehicles off of electricity.

By Randall Parker 2007 July 26 10:50 PM  Energy Electric Generators
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James Hansen Fears Runaway Ice Sheet Melting

Space scientist James Hansen, head of NASA's Goddard Institute for Space Studies, fears a runaway glacier melting scenario where sea levels will rise 5 meters.

The current rate of sea level change is not without consequences. However, the primary issue is whether global warming will reach a level such that ice sheets begin to disintegrate in a rapid, non-linear fashion on West Antarctica, Greenland or both. Once well under way, such a collapse might be impossible to stop, because there are multiple positive feedbacks. In that event, a sea level rise of several metres at least would be expected.

As an example, let us say that ice sheet melting adds 1 centimetre to sea level for the decade 2005 to 2015, and that this doubles each decade until the West Antarctic ice sheet is largely depleted. This would yield a rise in sea level of more than 5 metres by 2095.

Of course, I cannot prove that my choice of a 10-year doubling time is accurate but I'd bet $1000 to a doughnut that it provides a far better estimate of the ice sheet's contribution to sea level rise than a linear response. In my opinion, if the world warms by 2 °C to 3 °C, such massive sea level rise is inevitable, and a substantial fraction of the rise would occur within a century. Business-as-usual global warming would almost surely send the planet beyond a tipping point, guaranteeing a disastrous degree of sea level rise.

I see this outcome as unlikely for a few reasons:

  • We will run out of fossil fuels before we can increase atmospheric carbon dioxide up to levels where we could cause a massive melting. Global warming models of future CO2 emissions are unrealistic because they take the OPEC official oil and natural gas reserves at face value.
  • We will find much cheaper ways to produce non-fossil fuels energy sources and this will make fossil fuels much less appealing. People will find it easier to reject fossil fuels when the cost in living standards and lifestyles goes down due to technological advances. Growing opposition to coal electric plants illustrates where public attitudes are headed.
  • We will be able to cheaply engineer the climate to reverse a big warming. We could cool the planet for $100 million per year.

I'm not worried about global warming. I am worried about Peak Oil. Our future must be driven by electric power (and we can generate that electric with nukes, solar panels or wind turbines). But we aren't far enough along in the development of the batteries we need to replace most liquid fuel used in transportation. The transition period off of fossil fuels could therefore feature some really deep wrenching global recessions as economies reorder to deal with declining oil production. At the risk of boring long time readers, batteries are the key technology of our energy future.

Update: For more on climate engineering see here and here and here.

By Randall Parker 2007 July 26 10:30 PM  Climate Trends
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2007 July 25 Wednesday
Dog Muscle Mutation Useful For Humans?

If this mutation gets inserted into some human muscle cells would it make the human recipients more muscular?

Double muscling is a trait previously described in several mammalian species including cattle and sheep and is caused by mutations in the myostatin (MSTN) gene (previously referred to as GDF8). Here we describe a new mutation in MSTN found in the whippet dog breed that results in a double-muscled phenotype known as the “bully” whippet. Individuals with this phenotype carry two copies of a two-base-pair deletion in the third exon of MSTN leading to a premature stop codon at amino acid 313. Individuals carrying only one copy of the mutation are, on average, more muscular than wild-type individuals (p = 7.43 × 10−6; Kruskal-Wallis Test) and are significantly faster than individuals carrying the wild-type genotype in competitive racing events (Kendall's nonparametric measure, τ = 0.3619; p ≈ 0.00028). These results highlight the utility of performance-enhancing polymorphisms, marking the first time a mutation in MSTN has been quantitatively linked to increased athletic performance.

What I thought as I read about this dog muscle gene deletion mutation: Future genetic engineers looking to enhance human function will search through animal genetic variations and choose ones that provide desired enhancements. Take this myostatin mutation for example. Humans also have myostatin genes. A similar mutation introduced into human myostatin might yield the same enhancement to human musculature.

Other species of mammals are adapted to a large variety of conditions and ecological niches. They have many of the same genes but in different variations. We are going to find variations such as the one above that does something special for other species. These variations and their functional purposes are going to serve as a grab bag of pre-tested genetic variations that can allow humans to endow themselves with a large variety of special abilities that humans now lack.

By Randall Parker 2007 July 25 11:55 PM  Bodies Perfected Athletics
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Psychological Problems On Polar Teams Problematic For Space Exploration

A substantial portion of the people who spend long periods of time at the poles suffer serious psychological problems.

While some people on polar expeditions savor a gratifying sense of achievement, the researchers said, 40 to 60 percent of them may suffer negative effects like depression, sleep disruption, anger, irritability and conflict with co-workers.

About 5 percent of these people endure psychological disturbances severe enough to merit treatment with medication or therapy, the researchers said.

"Polar madness can take a variety of shapes," Lawrence Palinkas, a University of Southern California anthropologist who wrote the paper in the Lancet medical journal along with Peter Suedfeld of the University of British Columbia in Canada, said in a telephone interview.

I'm thinking that genetic screening could serve a useful purpose in selecting crews for moon and Mars bases. Suggestion for NASA and the US National Science Foundation: Collect DNA samples from everyone who goes to spend years down in Antarctica and record how each person does. Then look for genetic variations that predispose people to do well or poorly in isolated and extreme conditions.

The US Navy could conduct a similar research effort on the genetics and psychological adjustment of submarine crews. Also, functional magnetic resonance imaging and other measures of cognition could provide patterns to look for that distinguish those who will do well or poorly in isolated conditions.

By Randall Parker 2007 July 25 10:00 PM  Space Exploration
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New Solar Photovoltaic Cell Efficiency Record: 42.8%

A consortium of research teams has achieved a new record in photovoltaic cell efficiency.

5:14 p.m., July 23, 2007-- Using a novel technology that adds multiple innovations to a very high-performance crystalline silicon solar cell platform, a consortium led by the University of Delaware has achieved a record-breaking combined solar cell efficiency of 42.8 percent from sunlight at standard terrestrial conditions.

That number is a significant advance from the current record of 40.7 percent announced in December and demonstrates an important milestone on the path to the 50 percent efficiency goal set by the Defense Advanced Research Projects Agency (DARPA). In November 2005, the UD-led consortium received approximately $13 million in funding for the initial phases of the DARPA Very High Efficiency Solar Cell (VHESC) program to develop affordable portable solar cell battery chargers.

Combined with the demonstrated efficiency performance of the very high efficiency solar cells' spectral splitting optics, which is more than 93 percent, these recent results put the pieces in place for a solar cell module with a net efficiency 30 percent greater than any previous module efficiency and twice the efficiency of state-of-the-art silicon solar cell modules.

What I want to know: Are these materials inherently more or less expensive to manufacture for unit area than existing silicon photovoltaics? Do these materials lend themselves to greater cost reductions?

Big money is going to go into creation of a manufacturing prototype.

As a result of the consortium's technical performance, DARPA is initiating the next phase of the program by funding the newly formed DuPont-University of Delaware VHESC Consortium to transition the lab-scale work to an engineering and manufacturing prototype model. This three-year effort could be worth as much as $100 million, including industry cost-share.

The professors leading this effort are aiming for 50% efficiency.

The ground-breaking research was led by Allen Barnett, principal investigator and UD professor of electrical and computer engineering, and Christiana Honsberg, co-principal investigator and associate professor of electrical and computer engineering. The two direct the University's High Performance Solar Power Program and will continue working to achieve 50 percent efficiency, a benchmark that when reached would mean a doubling of the efficiency of terrestrial solar cells based around a silicon platform within a 50-month span.

Some are skeptical over whether solar electric energy will ever amount to much after decades of failing to become cost competitive. But my view is that many breakthroughs took decades to achieve. The fact that researchers have been searching for cheaper photovoltaic materials for decades isn't an argument against the feasibility of this quest. Rather, the number of first class minds pursuing this quest strongly suggests the ultimate goal of cheap and high efficiency photovoltaics is achievable.

By Randall Parker 2007 July 25 09:40 PM  Energy Solar
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Obesity Socially Contagious?

Using over 12,000 people studied over 32 years as part of the Framingham Heart Study Harvard and UCSD researchers find that people are more likely to become obese if people they are close to become obese.

Are your friends making you fat? Or keeping you slender? According to new research from Harvard and the University of California, San Diego, the short answer on both counts is “yes.”

Appearing in the July 26 issue of the New England Journal of Medicine, a study coauthored by Nicholas Christakis of Harvard Medical School and James Fowler of UC San Diego suggests that obesity is “socially contagious,” spreading from person to person in a social network.

The study – the first to examine this phenomenon – finds that if one person becomes obese, those closely connected to them have a greater chance of becoming obese themselves. Surprisingly, the greatest effect is seen not among people sharing the same genes or the same household but among friends.

If a person you consider a friend becomes obese, the researchers found, your own chances of becoming obese go up 57 percent. Among mutual friends, the effect is even stronger, with chances increasing 171 percent.

Christakis and Fowler also looked at the influence of siblings, spouses and neighbors. Among siblings, if one becomes obese, the likelihood for the other to become obese increases 40 percent; among spouses, 37 percent. There was no effect among neighbors, unless they were also friends.

Nicholas Christakis at Harvard thinks the evidence is strong enough to demonstrate a causal relationship.

“What we see here is that one person’s obesity can influence numerous others to whom he or she is connected both directly and indirectly,” says Nicholas Christakis, MD, PhD, a professor in Harvard Medical School’s Department of Health Care Policy. “In other words, it’s not that obese or non-obese people simply find other similar people to hang out with. Rather, there is a direct, causal relationship.”

Over the last 25 years, the incidence of obesity among U.S. adults has more than doubled, shooting from 15 to 32 percent. In addition, roughly 66 percent of U.S. adults are considered overweight.

In a way this makes sense. You do not feel as strong a need to maintain some form of appearance if the people around you let go.

The guys are less likely to follow their fat friends into fatness than the gals are.

Gender played an important role in how these statistics broke down. In same-sex friendships, individuals experienced a 71 percent increased risk if a friend of theirs became obese. This pattern was also observed in siblings. Here, if a man’s brother became obese, his chances of becoming obese increased by 44 percent. Among sisters, the risk was 67 percent. Friends and siblings of opposite genders showed no increased risk. While the researchers note that correlations among siblings provide evidence for a biological, and possibly even a genetic, component to obesity, patterns seen among friends indicate that there’s more than biology at work.

So if you are going to have fat friends make sure they are of opposite sex.

What to do with this information if it is true? Maybe virtual reality will help. See all your friends as skinny in virtual reality and you'll become more likely to keep off the pounds. Any other ideas?

Do people who are obsessed with skinny celebrities stay skinnier than those who do not suffer such obessions?

By Randall Parker 2007 July 25 07:59 PM  Brain Appetite
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2007 July 24 Tuesday
Renewable Energy Seen As Harmful To Environment

Jesse Ausubel , Director of the Program for the Human Environment at Rockefeller University, says that renewable energy sources are bad for the environment.

Renewable does not mean green. That is the claim of Jesse Ausubel of the Rockefeller University in New York. Writing in Inderscience's International Journal of Nuclear Governance, Economy and Ecology, Ausubel explains that building enough wind farms, damming enough rivers, and growing enough biomass to meet global energy demands will wreck the environment.

Ausubel argues that nuclear energy uses the smallest land footprint by far.

Ausubel has analyzed the amount of energy that each so-called renewable source can produce in terms of Watts of power output per square meter of land disturbed. He also compares the destruction of nature by renewables with the demand for space of nuclear power. "Nuclear energy is green," he claims, "Considered in Watts per square meter, nuclear has astronomical advantages over its competitors."

Ausubel sees the need for large amounts of land as the flaw with renewables.

On this basis, he argues that technologies succeed when economies of scale form part of their evolution. No economies of scale benefit renewables. More renewable kilowatts require more land in a constant or even worsening ratio, because land good for wind, hydropower, biomass, or solar power may get used first.

I gotta pick some nits here. First off, wind has economies of scale where the towers capture more energy the taller they get. Also, photovoltaics can be improved for conversion efficiency.

Hydro requires a lot of land.

A consideration of each so-called renewable in turn, paints a grim picture of the environmental impact of renewables. Hypothetically flooding the entire province of Ontario, Canada, about 900,000 square km, with its entire 680,000 billion liters of rainfall, and storing it behind a 60 meter dam would only generate 80% of the total power output of Canada's 25 nuclear power stations, he explains. Put another way, each square kilometer of dammed land would provide the electricity for just 12 Canadians.

Well, the steeper the drop the less land is required. The problem we have with hydro is we do not have enough steep drops and even if we did we'd be restricting the natural flow of huge quantities of river water and fish.

Ausubel sees biomass energy as terrible and I agree.

Biomass energy is also horribly inefficient and destructive of nature. To power a large proportion of the USA, vast areas would need to be shaved or harvested annually. To obtain the same electricity from biomass as from a single nuclear power plant would require 2500 square kilometers of prime Iowa land. "Increased use of biomass fuel in any form is criminal," remarks Ausubel. "Humans must spare land for nature. Every automobile would require a pasture of 1-2 hectares."

Some biomass wastes such as plant cuttings collected as part of trash collection could be used with little or no harm. But most biomass use competes with other species and basically takes food and habitat away from other species.

Again, Ausubel sees problems with wind. But can't wind towers be built on farm fields so that the same lands produce crops and energy simultaneously?

Turning to wind Ausubel points out that while wind farms are between three to ten times more compact than a biomass farm, a 770 square kilometer area is needed to produce as much energy as one 1000 Megawatt electric (MWe) nuclear plant. To meet 2005 US electricity demand and assuming round-the-clock wind at the right speed, an area the size of Texas, approximately 780,000 square kilometers, would need to be covered with structures to extract, store, and transport the energy.

At least wind towers would leave most of the ground area still available for wild plants and animals. Also, wind towers built off coast beyond visibility from land could leave land habitats undisturbed.

Ausubel finds fault with solar due to land area usage. But if photovoltaics were restricted for use only on existing structures (e.g. on houses, commercial buildings, and even on bridges) then the amount of additional land used could be minimized. The amount of area we'd need for solar power is two Ohios for enough solar power for the entire world. Though that's based on current world energy consumption and 10% efficient photovoltaics. We could create 50% efficient photovoltaics and then only put photovoltaics on human structures and get enough energy.

Update: For electric power currently our practical choices are coal (ugh), natural gas (dwinding in supply), wind (variable supply and not available everywhere), and nuclear. Solar is still too expensive. Though that will change. If you want to oppose some of these sources to the point of banning them or at least ceasing new construction then you've got to explain what else you'd want to use instead and how much more you are wiling to make us all pay to use your preferred alternative(s).

By Randall Parker 2007 July 24 11:20 PM  Energy Policy
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Gene Expression Shows Stem Cell Aging In Mice

Your stem cells grow old.

Stuart Chambers, Margaret Goodell, and their colleagues investigated the molecular mechanisms underlying aging of stem cells by looking at the gene expression profiles of aging hematopoietic stem cells (HSCs), the precursors of blood cells. They found that genes involved in the inflammatory and stress response became more active with age, while genes important for regulating gene expression and genomic integrity became less active. These results lend strong support to the notion that HSCs succumb to the wear and tear of aging, just like other cells, and shed light on the mechanisms of aging.

To study HSCs’ regenerative capacity over time, Chambers et al. isolated HSCs from young (aged 2 months) and old (aged 21 months) mice and then transplanted either young or old cells into mice whose bone marrow cells had been destroyed by radiation. The young and old HSCs gave rise to new marrow cells at roughly the same pace 4 weeks after transplantation. But at 8 and 16 weeks after transplantation, the old HSCs’ contributions had dropped considerably, suggesting that aging HSCs lose their repopulating capacity. Yet, because HSCs increased in number, overall blood production from HSCs remained stable.

This is good news. Our stem cells grow old. Youthful stem cells perform better than older stem cells in the same sorts of organisms. The development of techniques to create youthful stem cells will yield cells that make great rejuvenation therapies. Youthful stem cells probably will not create as much inflammation in the body.

The finding that genes involved in the inflammatory response are expressed more (called up-regulation) as HSCs age fits with evidence linking inflammation and aging in the kidney, brain, and arteries. It may also help explain why HSCs lose function. One of the up-regulated genes, P-selectin, encodes a cell surface adhesion molecule. Because transplanted HSCs depend on cell adhesion to colonize bone marrow properly, the researchers explain, inappropriate up-regulation of genes encoding P-selectin may interfere with this process.

This result illustrates why Aubrey de Grey calls for development of youthful stem cell therapies to replace aged reservoirs of stem cells in our bodies with younger stem cells. Our aging stem cells gradually malfunction in more and more ways. We'd feel and function at a much higher level if we had younger stem cells that could repair lots of aged tissues all over the body.

The full Plos Biology article is available online. About 3000 genes undergo changes in their levels of expression as a result of aging.

Age-related defects in stem cells can limit proper tissue maintenance and hence contribute to a shortened lifespan. Using highly purified hematopoietic stem cells from mice aged 2 to 21 mo, we demonstrate a deficit in function yet an increase in stem cell number with advancing age. Expression analysis of more than 14,000 genes identified 1,500 that were age-induced and 1,600 that were age-repressed. Genes associated with the stress response, inflammation, and protein aggregation dominated the up-regulated expression profile, while the down-regulated profile was marked by genes involved in the preservation of genomic integrity and chromatin remodeling. Many chromosomal regions showed coordinate loss of transcriptional regulation; an overall increase in transcriptional activity with age and inappropriate expression of genes normally regulated by epigenetic mechanisms was also observed. Hematopoietic stem cells from early-aging mice expressing a mutant p53 allele reveal that aging of stem cells can be uncoupled from aging at an organismal level. These studies show that hematopoietic stem cells are not protected from aging. Instead, loss of epigenetic regulation at the chromatin level may drive both functional attenuation of cells, as well as other manifestations of aging, including the increased propensity for neoplastic transformation.

I am very curious to know which genes or regulatory regions in chromosomes accumulate the most damage with age. If the number of key damaged areas is not too great then gene therapies could some day go in and repair those locations in the genome which accumulate damage.

By Randall Parker 2007 July 24 12:06 AM  Aging Mechanisms
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2007 July 23 Monday
Low Cholesterol From Statins Slightly Boosts Cancer Risks?

I hear Joe Jackson singing:

Everything
Everything gives you cancer
Everything
Everything gives you cancer
Theres no cure, theres no answer
Everything gives you cancer

You want benefits without costs? Keep looking. Cholesterol-lowering statin drugs probably cause a small boost in the risk of cancer.

Millions of Americans take statins to lower their cholesterol, but how low should you go" Many scientific studies support the benefits of lowering low-density lipoprotein (LDL) cholesterol, and achieving low LDL cholesterol levels is one of the most important steps in preventing heart disease. New research, however, provides evidence for an association between low LDL levels and cancer risk.

The authors of the study, published in the July 31, 2007, issue of the Journal of the American College of Cardiology (JACC), set out to understand how and why statins cause side effects, particularly damage to the liver and muscle cells. The study findings support taking multiple medications rather than high-dose statins to minimize those side effects. The researchers did not expect to find the increased cancer risk (one additional incident per 1,000 patients) from low LDL levels, and additional studies have already begun to investigate this potential risk further. A key component in future studies will be to confirm the risk and to identify whether the risk may be a side effect of statins or just low LDL.

“This analysis doesn’t implicate the statin in increasing the risk of cancer,” said lead author Richard H. Karas, M.D., F.A.C.C., professor of medicine at Tufts University School of Medicine. “The demonstrated benefits of statins in lowering the risk of heart disease remain clear; however, certain aspects of lowering LDL with statins remain controversial and merit further research.”

The researchers found one additional incident of cancer per 1,000 patients with low LDL levels when compared to patients with higher LDL levels. In their evaluation of randomized controlled statin trials published before November 2005, the researchers looked at 13 treatment arms consisting of 41,173 patients.

Do the statins directly cause damage to cells that leads to cancer? Or does the lowering of cholesterol somehow remove some brakes on cancer cell growth?

Keep in mind that statins lower risk of death from heart disease more than they increase the risk from cancer. Plus, the statin simvastatin appears to lower the risk of Parkinson's and Alzheimer's diseases.

If you want to lower your cholesterol without taking statins then try the ape diet.

By Randall Parker 2007 July 23 11:46 PM  Aging Treatment Studies
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2007 July 22 Sunday
High Glycemic Index Diet Linked To Blindness

One cause of blindness in old age happens more often in people who eat high glycemic index diets.

BOSTON -- Age-related macular degeneration (AMD) and its associated vision loss may be connected to the quality of carbohydrates an individual consumes. In a study published in the July issue of the American Journal of Clinical Nutrition, Allen Taylor, PhD, director of the Laboratory for Nutrition and Vision Research at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University, and colleagues confirmed earlier findings linking dietary glycemic index with the risk of developing AMD.

"Men and women who consumed diets with a higher glycemic index than average for their gender and age-group were at greater risk of developing advanced AMD," corresponding author Taylor says. "The severity of AMD increased with increasing dietary glycemic index."

The carbohydrates in lower glycemic index foods break down more slowly into simple sugars in the digestive tract. Therefore the sugar enters the bloodstream more slowly and blood sugar levels do not spike as high. It is those high blood sugar level spikes that cause damage to eyes and to other parts of the body. For this reason diabetics age more rapidly and suffer from blindness, loss of circulation in the extremities, and other problems. We can probably expect a lower glycemic index diet to reduce the incidence of some of the diseases that plague diabetics.

It is worth noting that people who eat lower glycemic index diets are typically eating more vegetables and whole grains that contain assorted beneficial compounds. So I don't think we can be certain whether the benefit reported here is totally due to the lower glycemic. However, it doesn't matter in one sense. If you eat the vegetables that lower dietary glycemic index you'll get the benefits regardless of the mechanisms of action.

Glycemic index is a scale applied to foods based on how quickly the carbohydrates in foods are converted to blood sugar, or glucose. Foods like white rice, pasta and bread are examples of foods with a high-glycemic-index, meaning that these foods are associated with a faster rise and subsequent drop in blood sugar. Whole wheat versions of rice, pasta and bread are examples of foods that have a low-glycemic-index. These foods are often considered higher quality carbohydrates because they are associated with a slower and less dramatic rise and fall of blood sugar.

Rices come in a large range of glycemic indexes. The sticky rice found in Chinese restaurants has one of the high glycemic indexes. Basmati rice is much lower and Uncle Ben's Converted Rice lower still. But grains including rice are generally higher in glycemic than beans and vegetables. If you want to eat a low glycemic index diet best to cut way back on grains and eat more beans, vegetables, and fruits.

Eating a lower glycemic index diet could probably cut your AMD risk by 20% and maybe more.

"Although carbohydrate quality was not the main focus in the AREDS, we were fortunate that the investigators had collected the dietary carbohydrate information we needed to do our analyses," says Taylor, who is also a professor at the Friedman School of Nutrition Science and Policy at Tufts and the Tufts University School of Medicine. "Our findings suggest that 20 percent of the cases of advanced AMD might have been prevented if those individuals had consumed a diet with a glycemic index below the average for their age and gender," notes Taylor.

The mechanism by which high glycemic index foods boost your risk of blindness also probably does damage in other parts of your body. So lowering your diet's average glycemic index will deliver other benefits. Plus, if you lower your glycemic index by eating more vegetables you'll benefit from vitamins and assorted other beneficial nutrients found in vegetables.

Check out David Mendosa's chart of glycemic index and glycemic load for hundreds of foods.

Update: Another way to reduce the risk of AMD: genetically engineer yourself to have genes that lower your risk of AMD.

They found that a variant in the complement C3 gene influenced the risk of developing AMD. For the 30% of the population who carry one copy of the so-called ‘fast’ variant the risk of AMD was increased by 70%, and for the 4% of people with two copies of the ‘fast’ variant the risk of AMD was more than doubled.

AMD can take two forms called ‘wet’ (also called choroidal neovascularisation or CNV) and ‘dry’ (also called geographic atrophy or GA). The ‘fast’ variant in the C3 gene increases the risk of both forms of the disease.

The complement C3 gene has a central role in the immune system. The results of this research provide strong evidence that inflammation is an important part of the disease process in AMD.

I think we are going to find that the diseases in our ancestral past selected for humans who have over-enthusiastic immune systems that cause damaging inflammation.

By Randall Parker 2007 July 22 08:56 PM  Aging Diet Eye Studies
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Electric Motorcycles Coming To Market

Due to Peak Oil (world oil production peaking and declining) we might be less than 5 years away from almost $200 per barrel oil (though I think inelasticity of oil demand is not high enough to make that possible). So then are we all going to start walking around with shotguns fighthing over dwindling food supplies in a post-oil apocalyptic society? Of course not - at least not in industrialized countries. What then? Electric motorcycles.

The Vectrix scooter ($11,000) uses nickel metal hydride batteries--the same type used now in the popular Toyota Prius hybrid. This type of battery is lighter than lead-acid batteries and more durable: Vectrix claims it has a 10-year lifetime. Lithium-ion batteries, in turn, are lighter than nickel metal hydride, and new chemistries have made them durable as well, lasting as long as or longer than nickel metal hydride batteries. The Vectrix scooter weighs about 200 kilograms, while the lithium-ion-powered Enertia ($12,000), made by Brammo Motorsports of Ashland, OR, weighs just 125 kilograms.

Curiously, the two lithium ion (Li ion) bikes have shorter ranges than the nickel metal hydride (NiMH) bike.

The Zero motorcycle is now available with a 40-mile-range battery, and it will have an optional 80-mile pack, Saiki says. The Vectrix scooter can go up to 60 miles on a charge, while the Enertia can go up to 45 miles.

That might reflect high costs for the Li ion batteries at this point. Brammo is using A123 Systems batteries in their Zero. If A123 wins a production contract from GM and scales up production for cars I'm expecting substantial price drops for their batteries. If another competitor wins a GM production contract then that competitor will start selling for much cheaper. Either way, the price will come down as Li ion batteries move into production for cars and trucks.

Enertia is claiming a fuel efficiency of 2.42 kilometers (km) per megajoule (MJ). What does that mean? First off, 1 kilowatt-hour of electricity is 3.6 MJ. So then 1 kwh (which costs about 10 cents/kwh on average in the United States) can move the motorcycle 2.42 km (1.5 miles) times 3.6 for 8.7 kilometers (5.4 miles). That's less than 2 cents per mile. If you were to ride it 10,000 miles it would cost you $200. If you live in the highest electric cost state of Hawaii (22 cents/kwh) then it'll cost you $440. For California (14.32 cents/kwh) it would cost you $286. That is why Peak Oil won't cause a total collapse of civilization. The world is going to shift to electricity for transportation: electric cars, electric trains, electric motorcycles, and the Segway. We can generate the electricity with nuclear, wind, and eventually solar power.

Update: The Enertia uses .185 kwh/mile (1/5.4). In the comments of an earlier post Nick pointed me to a US Department of Energy Pacific Northwest National Laboratory report on the feasibility of pluggable hybrid electric vehicles (i.e. hybrids that can get recharged at home and run off cheaper wall socket electricity for part of the time). Table 1 on page 9 has an interesting table of kwh/mile for 4 sizes of vehicles:

Vehicle ClassSpecific Energy Requirements
[kWh/mile]
Size of Battery for PHEV33
[kWh]
Compact sedan0.268.6
Mid-size sedan0.309.9
Mid-size SUV0.3812.5
Full-size SUV0.4615.2

This chart is problematic for those who hope that the end of the fossil fuels era will spell the death of the large SUV. With sufficiently advanced battery technology you could take 2 round trips across the United States of 12,000 miles total and if you charge up at the average rate of about 10 cents/kwh then you'll only spend $552 in fuel costs. If you charge up late at night using off-peak pricing then you might be able to cut your cost down to a third or less.

That rosy scenario for cheap SUV travel requires a few elements. First, it requires batteries that can store a lot of energy per weight. The batteries would have to be fairly cheap and last through many charges. Plus, the batteries would need to charge quickly so that you could stop for lunch and recharge while you eat.

To get down to super cheap prices for travel would require government regulatory agencies to allow dynamic pricing based on level of demand so that late night electric power could cost much less than daytime power. I think that once electric cars take off the interests of the electric car owners will create pressure for such reforms.

Even before we get batteries suitable for long trips we'll get batteries suitable for shorter commuting hops. The third column in the table above describes how much battery capacity is needed for a car to travel 33 miles on a single charge. That would encompass most commuting round trips and other daily round trips.

By Randall Parker 2007 July 22 03:34 PM  Energy Electric Cars
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2007 July 21 Saturday
Carbon Nanotubes And Fullerenes Make Paintable Photovoltaics

Some day we'll be able to paint outside surfaces in order to turn them into solar photovoltaic electric power generators.

Researchers at New Jersey Institute of Technology (NJIT) have developed an inexpensive solar cell that can be painted or printed on flexible plastic sheets. “The process is simple,” said lead researcher and author Somenath Mitra, PhD, professor and acting chair of NJIT’s Department of Chemistry and Environmental Sciences. “Someday homeowners will even be able to print sheets of these solar cells with inexpensive home-based inkjet printers. Consumers can then slap the finished product on a wall, roof or billboard to create their own power stations.”

“Fullerene single wall carbon nanotube complex for polymer bulk heterojunction photovoltaic cells,” featured as the June 21, 2007 cover story of the Journal of Materials Chemistry published by the Royal Society of Chemistry, details the process. The Society, based at Oxford University, is the British equivalent of the American Chemical Society.

These solar cells are built out of carbon nanotubes and carbon fullerenes.

The solar cell developed at NJIT uses a carbon nanotubes complex, which by the way, is a molecular configuration of carbon in a cylindrical shape. The name is derived from the tube’s miniscule size. Scientists estimate nanotubes to be 50,000 times smaller than a human hair. Nevertheless, just one nanotube can conduct current better than any conventional electrical wire. “Actually, nanotubes are significantly better conductors than copper,” Mitra added.

Mitra and his research team took the carbon nanotubes and combined them with tiny carbon Buckyballs (known as fullerenes) to form snake-like structures. Buckyballs trap electrons, although they can’t make electrons flow. Add sunlight to excite the polymers, and the buckyballs will grab the electrons. Nanotubes, behaving like copper wires, will then be able to make the electrons or current flow.

Does Mitra argue this approach is cheap because it is cheap already? Or does his approach depend on the eventual development of much cheaper ways to produce nanotubes or buckyballs? Does anyone know what the state of the play is for creation of carbon nanomaterials on an industrial scale?

If this stuff becomes cheap enough then it would not matter that the carbon bonds gradually break down due to UV light hitting them. One could just repaint surfaces every 7 or 10 years. Note that car and house paint can last that long and longer.

Cheap photovoltaics will make mid day electricity much cheaper than late afternoon and evening electricity. We need dynamic electric pricing in order to use photovoltaic electricity efficiently. We have plenty of ways to shift our demand around in a 24 period or even between seasons in some cases. Cheap photovoltaics might lead electric intensive industries such as aluminum to shift the bulk of their processing to spring and summer and into areas such as Arizona which have the most sunlight.

By Randall Parker 2007 July 21 10:31 PM  Energy Solar
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Newer Drugs Increase Longevity

Get on the cutting edge. States where people take the latest drugs have longer life expectancies.

It is no surprise that Americans are living longer today than in previous generations. A typical baby born in 1900 was expected to live to about age 45. Today, life expectancy at birth is about 78. Less well known, however, is the fact that the gains in life expectancy have not been uniform across the country. In his new study—the first of its kind—Columbia University researcher Frank Lichtenberg set out to find out which states are the leaders, which ones are the laggards, and why.

Lichtenberg began by constructing life-expectancy estimates of residents in all fifty states using data from the National Center for Health Statistics. He found that in 2004, on average, residents of Hawaii (81.3 years) and Minnesota (80.3 years) lived six or seven years longer than residents of Mississippi and Louisiana (74.2 years).

In addition, he found that while nationwide life expectancy increased by 2.33 years from 1991 to 2004, the increase varied greatly among the states. Certain states—New York (4.3 years), California (3.4 years), and New Jersey (3.3 years)—led the way, while others–Oklahoma (0.3 years), Tennessee (0.8 years), and Utah (0.9 years) trailed the national average by significant margins.

See the full article for a list of life expectancies by state. But since there are differences in life expectancy due to genetic effects of race and ethnicity and also due to regional dietary differences and other causes you can't assume that moving to a state with higher average life expectancy will increase your own life expectancy. Better to adopt life extending practices right where you are.

The newer the average age of used drugs the greater the increase in longevity. This argues against use of generic drugs (though they can be best of breed in some cases).

Lichtenberg then set out to examine why this “longevity increase gap” exists by measuring the impact of several factors that researchers agree could affect life expectancy. He found that, although some obvious suspects—obesity, smoking, and the incidence of HIV/AIDS—played a role, the most important factor was “medical innovation.”

Specifically, Lichtenberg found that longevity increased the most in those states where access to newer drugs—measured by mean “vintage” (FDA approval year)—in Medicaid and Medicare programs has increased the most. In fact, about two-thirds of the potential increase in longevity—the longevity increase that would have occurred if obesity, income, and other factors had not changed—is attributable to the use of newer drugs. According to his calculations, for every year increase in drug vintage there is about a two-month gain in life expectancy. These represent important findings given the fact that the costs of prescription drugs continue to receive a great deal of attention in the ongoing debate over health-care policy, while their benefits are often overlooked.

Attempts to regulate and reduce drug prices will slow the growth rate in longevity by reducing the economic incentive to develop new drugs. We need more new drug development. More new chemical compound drugs can raise life expectancy even further. But we need to move to new types of medical treatments in order to achieve a really big burst in medical treatment efficacy. In particular, stem cells, gene therapies, and nanodevices will some day stop aging altogether and even reverse the aging process.

Economists who favor ever increasing income growth need to come up with an answer to Lichtenberg's claim that rising incomes work against growth in life expectancy.

• Growth in obesity and, interestingly, growth in income were both inversely related to (and presumably reduced) the growth in life expectancy.

If obesity and income had not increased, life expectancy at birth would have increased by 3.88 years from 1991 to 2004, instead of the actual 2.33-year increase. Thus, 3.88 years is the “potential increase in life expectancy at birth.”

• Of the 3.88-year potential increase in life expectancy at birth, medical innovation (i.e., the increase in Medicaid and Medicare drug vintage) accounted for 2.43 years (63%). The declines in AIDS incidence and smoking accounted for 0.23 and 0.12 years (6% and 3%), respectively. About 1.1 years (28%) of the potential increase in life expectancy at birth is unexplained.

• If obesity and income had not increased, life expectancy at age 65 would have increased by 2.15 years from 1991 to 2004, instead of the actual 1.29-year increase. Thus, 2.15 years is the “potential increase in life expectancy at age 65.”

• Of the 2.15-year potential increase in life expectancy at age 65, medical innovation (i.e., the increase in Medicaid and Medicare drug vintage) accounted for 1.19 years (55%). The declines in AIDS incidence and smoking accounted for 0.07 and 0.12 years (3% and 5%), respectively. About 0.8 years (36%) of the potential increase in life expectancy at age 65 is unexplained.

Did the income growth come as a result of harder worker and more daily stress? Or does the income effect come because people who do less physical work earn more money on average but get less daily exercise?

I see the effects of rising incomes as a mixed bag. On the positive side (and probably more important in the long run), people with higher incomes can afford to pay more for health care directly and through taxes. Their high incomes provide the incentives for medical centers and drug companies to develop new treatments. Rising affluence makes more money available for medical care and for research.

Rising affluence also allows more people to do science and technology because a declining portion of the population needs to grow food and do other basic activities needed for short term survival. The general advance in science and technology produces technologies from other industries which greatly speed up work in biomedical research laboratories.

When gene therapies, stem cell therapies, replacement organ growth techniques, and nano repair devices become usable in medical treatment we are going to witness an increase in life expectancy measured in decades and centuries. What we are seeing now with our latest drugs is a small harbinger of what will come.

By Randall Parker 2007 July 21 09:45 AM  Aging Treatment Studies
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Orange Juice Compounds Prevent Free Radical Generation

Free radicals and other types of reactive oxygen species (ROS) will accelerate aging if present in higher than optimal concentrations. Flavonoids in orange juice quench reactive oxygen species (ROS)

BUFFALO, N.Y. -- Orange juice, despite its high caloric load of sugars, appears to be a healthy food for diabetics due to its mother lode of flavonoids, a study by endocrinologists at the University at Buffalo has shown.

But some reactive oxygen species (ROS) are needed to carry out basic metabolic functions. So would consumption of too much flavonoids make one lethargic?

Consumption of glucose sugar boosts blood ROS. That spike in ROS is probably harmful and best avoided. So one should probably prefer foods that one can eat without getting the ROS spike.

"Many major diseases are associated with oxidative stress and inflammation in the arterial wall, so the search for foods that are least likely to cause these conditions must be pursued," said Paresh Dandona, M.D., Ph.D., head of the Diabetes-Endocrinology Center of Western New York and senior author on the study.

"Our previous work has shown that 300 calories of glucose induces ROS and other proinflammatory responses," said Dandona, who is Distinguished Professor of Medicine in the UB School of Medicine and Biomedical Sciences.

Orange juice did not boost blood ROS. But plain fructose without any flavonoids didn't boost blood ROS either.

The resulting study involved 32 healthy participants between the ages of 20 and 40, who were of normal weight, with a body mass index of 20-25 kg/m2. Participants were assigned randomly and evenly into four groups, who would drink the equivalent of 300 calories-worth of glucose, fructose, orange juice or saccharin-sweetened water.

Fasting blood samples were taken before the test and at 1, 2 and 3 hours after a 10-minute period to consume the drinks.

Results showed a significant increase in ROS within 2 hours in samples from the glucose group but not in those from the fructose, orange juice or water group.

However, two flavonoids found in orange juice inhibit ROS generation.

An additional round of test on the samples showed that neither fructose nor vitamin C suppressed the oxygen free radicals. However the two types of flavonoids in orange juice -- hesperetin and naringenin -- inhibited ROS generation by 52 percent and 77 percent, respectively.

We need orange juice that contains less fructose and more flavonoids.

More generally: We need better availability of fruits that haven't been bred to be very sweet. I always look for apple varieties that taste less sweet but which have tangier taste. Red Delicious is too sweet for my taste. I try to avoid calories while getting more beneficial compounds which have no calorie content.

By Randall Parker 2007 July 21 08:49 AM  Aging Diet Studies
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Low Glycemic Index Diets Better For Weight Loss

A Cochrane Review meta-analysis of high and low glycemic index diets found that weight loss is greater and easier on low glycemic index diets.

Put aside the white bread and pick up an apple. A diet of foods less likely to spike blood sugar levels helps dieters lose more weight, according to a new systematic review from Australia.

“Losing weight is very difficult and many people are unable to sustain a weight-loss diet. The low glycemic index diet is satisfying and has proven benefits,” said review co-author Elizabeth Elliott, Ph.D., professor at the University of Sydney, The Children’s Hospital at Westmead.

It is disappointing that they could find only 6 suitable trials with a total of 202 adults.

Researchers evaluated randomized controlled trials that compared weight loss in people eating foods low on the glycemic index to weight loss in people on higher GI diets or other types of weight loss plans.

Six trials, involving 202 adults from Australia, France, South Africa, Denmark and the United States were included in the review. The diets lasted from five weeks to six months.

While the average low glycemic index dieter lost 2.2 pounds more the weight loss was even greater for obese dieters.

The review found that dieters focused on eating low GI foods dropped significantly more weight — about 2.2 pounds more — than participants on other diets. Low GI dieters also experienced greater decreases in body fat measurements and body mass index.

None of the studies reported adverse effects associated with consuming a low glycemic index diet.

“Compared to other diets, the low GI diet is more satisfying — people are less inclined to feel hungry. One advantage of this type of diet is that it is more likely to be maintained than other strict diets on which people feel hungry,” Elliott said.

Low glycemic diets appear to be effective even in obese people who need to lose considerable amounts of weight, the authors said.

In the two studies that evaluated only obese participants, low GI dieters lost about 9.2 pounds, compared with about 2.2 pounds shed by other dieters.

These results are not surprising. The higher blood sugar spikes after a meal the more insulin that pancreatic cells will release into the blood to bring it down. The insulin will make the blood sugar go down and all the food will get absorbed pretty quickly. Then you'll feel the need for more food.

High blood sugar spikes cause bad blood lipid profiles. So again it is not surprising that the lower glycemic index diets yield better blood cholesterol levels.

In the three studies that measured cardiovascular risk factors, people eating low GI foods experienced greater improvements in total blood cholesterol and low-density lipoprotein (LDL) — sometimes called “bad” cholesterol. High levels of total cholesterol and LDL cholesterol increase the risks for heart disease.

A professor at John Hopkins' public health school notes the paucity of good research on the weight effects of low glycemic index diets.

After reviewing the findings, Lawrence Cheskin, M.D. said, “There’s surprisingly little in the way of studies to draw any hard and fast conclusions.” Cheskin is director of the Johns Hopkins Weight Management Center and associate professor at Johns Hopkins Bloomberg School of Public Health in Baltimore. He was not involved with the review.

Most vegetables are very low glycemic index foods. But most people do not want to eat large quantities of vegetables every day.

Low glycemic index diets can be effective for weight management, Cheskin said, but the success of low glycemic diets lies with an individual’s willingness to comply with its nutritional principles.

“There aren’t many people who need to lose weight who are willing to eat lots of vegetables and whole grains. If they did, they wouldn’t have a weight problem in the first place,” Cheskin said.

A lot of people want to know what constitutes the ideal diet. The problem is that they've heard many times about the benefits of vegetables and filtered out that information as basically an unacceptable answer. They don't want to hear that the ideal diet involves eating 5 or 10 servings of vegetables each day. There aren't a few super high nutrient yummy foods that can substitute for low glycemic index vegetables. You have to eat more veggies.

By Randall Parker 2007 July 21 08:20 AM  Brain Appetite
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2007 July 19 Thursday
Do We Need More Babies Or Higher Producing Babies?

Writing in the Times of London Melanie McDonaghon argues that Europe needs more babies to pay for the retirement of older generations.

Europe needs more babies – the average continental family has a mere 1.37 children. Cutting back non-EU immigration to limit pressure on housing stock would help. So would state cash handouts. In Portugal, where the birthrate has fallen to 1.7 children per couple, the Government has considered giving tax breaks to people who have more than two children and levying higher taxes on those who have fewer. Germany is similarly concerned – it could lose the equivalent of the population of the former East Germany within 50 years. Russia’s population is contracting at the rate of three quarters of a million a year: the resourceful Mr Putin is paying mothers to have a second child.

Let us leave aside, for the moment, the eventual development of rejuvenation therapies which will make restrictions on reproduction necessary (unless you like the idea of covering the world with structures of gradually increasing heights). Suppose that industrialized countries really need babies. What kind of babies (dare I ask?) do industrialized countries really need? Wealth creators and large net taxpayers. Babies that will grow up to produce lots of goods and services and pay lots of taxes. Babies that earn high incomes on which lots of taxes can be extracted. In a nutshell: quality over quantity.

The approach of commentators who argue for more babies tends to be a game of playing averages. If women have more babies some small subset of those babies will grow up to become the highly skilled and high producing workers. Those workers and not the majority create the wealth and provide the services needed to take care of older generations. Well, suppose we could just create those workers rather than create a much larger set out of which the high producers emerge.

Smarter people have, on average, greater capacities to produce wealth. But not all very high IQ people choose to accumulate lots of wealth. In fact quite a few very smart people choose occupations that they find intellectually entertaining and not too demanding. Some get tenure in colleges and universities that do not expect much research output. Others get jobs where they are the smartest in their corporate or government department. In such jobs they can coast along and produce about as much as others without need for hard work.

The problem of smart underachieving low producers is solvable. Some people are workaholics. Some are smart. Some are accumulators and investors. Surely genetic factors play a role in all three of these characteristics. The coming era of extremely cheap DNA testing will allow us to identify all the genetic variations that influence how smart, hard working, wealth creating, and wealth accumulating humans become. Then genetic engineering techniques applied to reproduction will provide a way to create smart miser workaholic babies.

Once offspring genetic engineering becomes technologically possible the question arises as to what governments will tolerate or require for people who want to genetically engineer their babies. I'm about to propose something that might not become politically doable by Western countries (though the more pragmatic Chinese might pick up on it): Restrict reproduction to allow only the creation of wealth creators. I'm not saying restrict reproduction to those who own their own high tech companies and those who write lots of patents. Couples determined to reproduce in the face of legal requirements for the creation of big net assets offspring could use genetic engineering techniques to insert some genetic variations that will bring their babies up to legal standards.

If anyone is tempted to get all morally indignant on me: I do not recognize a basic right to reproduce. How can an act that creates huge external costs be a right? Second, eugenics is not an evil word. People practice eugenics on pets quite routinely. People practice human eugenics when they choose mates.

The main question to decide on eugenics isn't whether to do it. We will do it more and more as we develop more powerful tools for choosing offspring genetic characteristics. The main questions on eugenics revolve around which genetic choices produce costs and benefits for all of us and how big of costs come from each choice.

The general public isn't yet ready to seriously debate what our goals should be in the use of eugenic practices because we still lack the technology which will enable us to make eugenic choices. But the era of offspring genetic engineering is fast approaching and we need to start thinking about these questions.

By Randall Parker 2007 July 19 11:01 PM  Trends Demographic
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2007 July 18 Wednesday
Simvastatin Cuts Alzheimers And Parkinsons By Half

Cholesterol lowering statin drug simvastatin appears to cut the risk of degenerative neurological disorders Alzheimer's Disease and Parkinson's Disease by nearly half.

Boston, MA -- Researchers from Boston University School of Medicine (BUSM) have found that the statin, simvastatin, reduces the incidence of Alzheimer’s disease and Parkinson’s disease by almost 50 percent. This is the first study to suggest that statins might reduce the incidence of Parkinson’s disease. These findings, will be published in the July online open access journal BioMed Central (BMC) Medicine.

Alzheimer’s disease or dementia is one of the major public health threats that individuals face as they age. Statins are a class of medications that reduce cholesterol by inhibiting HMG-CoA reductase.

The researchers examined data from the Decision Support System database of the United States Veterans Affairs Medical System, a database of medical centers throughout the United States which contains diagnostic, pharmaceutical and demographic information on approximately 4.5 millions people.

Using three different models for analysis, the researchers examined the effects of three different statins (atorvastatin, lovastatin and simvastatin) and found that simvastatin showed a strong reduction in the incidence of Alzheimer’s disease in each of the models. The data also showed the same statin was associated with a reduced incidence of Parkinson’s disease.

The researchers speculate that the selective benefit observed with simvastatin might be due to the combination of high potency and the ability to enter the brain.

Might the disease risk reduction come as a side effect of lowering cholesterol? That mechanism of action would tend to slow the accumulation of plaque in arteries in the brain. But the other statins did not yield as big a benefit. This suggests that even those of us with low cholesterol might derive benefit from taking simvastatin.

If you are taking Zocor, Lipex, or a generic equivalent then you are taking simvastatin. Mevacor and Altocor are simvastatin brand names. Also, Lipitor and Torvast are atorvastatin brand names. My guess is that they didn't study Crestor because it is relatively newer and without as many long term users.

A much larger number of simvastatin users was used in this study.

An international team led by Benjamin Wolozin, MD, at Boston University School of Medicine used data from the US Veterans Affairs Database, which contains diagnostic, medication and demographic information on 4.5 million subjects. The researchers used statistical models to compare different statins, looking at data on over 700,000 simvastatin users and more than 50,000 atorvastatin users. The team targeted those aged 65 or over with no prior diagnosis of Alzheimer’s disease, who had been taking statins for at least seven months.

The researchers found that for subjects aged 65 and over, simvastatin was linked with a significantly reduced number of cases of dementia and Parkinson's disease". The researchers also made the surprising finding that not all statins are equal when it comes to dementia or Parkinson’s disease. A small reduction in dementia cases was seen among those who regularly take atorvastatin, which did not reach a level of statistical significance. Lovastatin was not found to have any significant effect on dementia, and neither atorvastatin nor lovastatin were associated with a reduction in the number of cases of Parkinson’s disease.

Statins might reduce Alzheimer's and Parkinson's risks by anti-inflammatory effects. Statins might change the rate of cellular beta amyloid synthesis or secretion. Though the evidence is not clear.

Since brain aging is the hardest part of aging to reverse any treatments that slow down the rate of brain aging and degeneration have great value. We need to keep our brains alive while waiting for the gene therapies, cell therapies, and nanodevice therapies that will allow us to turn back the biological clock on brain aging processes.

By Randall Parker 2007 July 18 11:22 PM  Brain Aging
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2007 July 17 Tuesday
Learned Fear Response Reversible In Mice

Identification of a molecular mechanism involved in learned fear response suggests that chronic disabling fears might be extinguishable.

CAMBRIDGE, Mass.--Researchers from MIT's Picower Institute for Learning and Memory have uncovered a molecular mechanism that governs the formation of fears stemming from traumatic events. The work could lead to the first drug to treat the millions of adults who suffer each year from persistent, debilitating fears - including hundreds of soldiers returning from conflict in Iraq and Afghanistan.

A treatment for post traumatic stress disorder and other learned fears would help a lot of people.

Kinase enzymes attach phosphate groups onto proteins and this gets used in cells to regulate many aspects of cellular activity. Inhibition of a kinase called Cdk5 undoes a learned fear response.

Li-Huei Tsai, Picower Professor of Neuroscience in the Department of Brain and Cognitive Sciences, and colleagues show that inhibiting a kinase (kinases are enzymes that change proteins) called Cdk5 facilitates the extinction of fear learned in a particular context. Conversely, the learned fear persisted when the kinase's activity was increased in the hippocampus, the brain's center for storing memories.

Cdk5, paired with the protein p35, helps new brain cells, or neurons, form and migrate to their correct positions during early brain development. In the current work, the MIT researchers looked at how Cdk5 affects the ability to form and eliminate fear-related memories.

"Remarkably, inhibiting Cdk5 facilitated extinction of learned fear in mice. This data points to a promising therapeutic avenue to treat emotional disorders and raises hope for patients suffering from post-traumatic stress disorder or phobia," Tsai said.

I wonder if the Cdk5 inhibitor just extinguishes the fear response to the original memory or does it wipe out the original memory?

By Randall Parker 2007 July 17 10:33 PM  Brain Emotion Alteration
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2007 July 16 Monday
Old Folks Lose Ability To Detect Jokes

Some oppose the development of therapies to reverse aging because they argue that aging is a beautiful and dignified natural process. In this Panglossian view of aging the silver in one's hair is akin to a measure of accumulated wealth of wisdom and understanding. But the reality is a much uglier accumulation of losses - most notably including cognitive losses. For example, older people experience a declining ability to comprehend humor.

July 11, 2007 -- It's no laughing matter that older adults have a tougher time understanding basic jokes than do younger adults.

It's partially due to a cognitive decline associated with age, according to Washington University in St. Louis researchers Wingyun Mak, a graduate student in psychology in Arts & Sciences, and Brian Carpenter, Ph.D., Washington University associate professor of psychology.

Humor comprehension in older adults functions in a different fashion than humor comprehension in younger adults. The researchers studied older adults from a university subject pool as well as undergraduate students. The subjects participated in tests that indicated their ability to complete jokes accurately as well as tests that indicated their cognitive capabilities in areas of abstract reasoning, short-term memory, and cognitive flexibility. Overall, older adults demonstrated lower performance on both tests of cognitive ability as well as tests of humor comprehension than did younger adults.

Aging is an accumulation of damage and losses. We should defeat aging. The breakdown and decay of our metabolisms is a bad thing. We need rejuvenation therapies. Such therapies are on the horizon but we should push harder to pull that prospect closer in our future.

By Randall Parker 2007 July 16 10:53 PM  Brain Aging
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2007 July 15 Sunday
Automated Tailgating Would Save Fuel

I've previously argued that any automated car safety technology that reduces deaths will become required by governments including eventually robotic driving once it becomes safer than human driving. Well, let me add some more reasons why governments will mandate robotic driving: Automatic control of groups of cars going down a freeway will increase fuel efficiency and reduce traffic jams.

An automated way of allowing cars to drive much closer to each other in heavy moving traffic, so-called platooning, could cut congestion, save fuel and cut greenhouse gas emissions, according to research published today in Inderscience's International Journal of the Environment and Pollution.

Don't you just hate it when in heavy traffic one guy hits his breaks and then cars behind hit theirs even harder as they see brake lights and suddenly a lump of cars has slowed way down? If a long line of cars ran under computer coordination this cause of traffic slow-downs could be greatly reduced.

As populations grow and the number of vehicles on the roads in cities and motorways across Europe, North America and the developing world, rises, traditional ways of tackling the problem, such as simply building more roads or improving public transport are becoming less and less effective. "Automated highway systems are one of the many approaches that have been suggested to tackle the problems," says Mitra.

Traffic is a growing problem across the globe with the number of vehicles on the on the roads in Britain alone having risen from 26 million to almost 33 million in the last decade and that number set to rise by 25% over the next ten years. The problem is burgeoning in areas of enormous economic growth, such as China and India where countless new vehicles are pulling out and entering the traffic flow on newly built roads. With all that new traffic, of course, comes more pollution, and the need for ever more innovative approaches to tackling it.

Technologies that are a step in this direction already have reached the market under the title of autonomous (or active or adaptive or intelligent) cruise control where a laser or radar on the front of a car detects other cars in front driving at lower speeds and the cruise control slows the car to run at the same speed as the car in front of it. This is still an expensive luxury option.

Computers that communicate between cars to coordinate acceleration could do a much better job of avoiding the need for any car to hit the brakes in the first place. Cars could run more closely together if they were far less likely to do unpredictable things.

IBM and other companies are trying to develop algorithms for processing and displaying sensor data to drivers and to make decisions for drivers.

IBM calls the research initiative collaborative driving, and the company says it's designed to prevent accidents and reduce traffic congestion. The work will be spearheaded by the IBM lab in Haifa, Israel. "More than a million people die on the roads every year around the world, and people waste a lot of time and money sitting in traffic jams," says IBM researcher Oleg Goldshmidt. "You would like to help with both problems in any way possible."

Humans are too error-prone behind the wheel. Slowly but surely driving is getting automated.

By Randall Parker 2007 July 15 09:32 PM  Robotics Cars
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Selenium Risk Factor For Type 2 Diabetes

Vitamins and minerals supplements aren't automatic sure wins on the health front. Too much selenium might boost the risk for the form of diabetes that makes cells resistant to the effects of insulin.

PHILADELPHIA -- A new analysis of data from a large national study found that people who took a 200 microgram selenium supplement each day for almost eight years had an increased risk of developing type 2 diabetes than those who took a placebo or dummy pill.

The data came from the Nutritional Prevention of Cancer Trial (NPC), a large randomized, multi-center, clinical trial from the eastern United States, designed to evaluate whether selenium supplements prevent skin cancer. In the study being published, researchers selected 1,202 participants who did not have diabetes when they were enrolled in the NPC Trial. Half received a 200 microgram selenium supplement and half received a placebo pill for an average of 7.7 years.

Saverio Stranges, MD, PhD, lead author of the study, says that the findings from this study suggest that selenium supplements do not prevent diabetes and that they might be harmful. “At this time, the evidence that people should take selenium supplements is extremely limited. We have observed an increased risk for diabetes over the long term in the group of participants who took selenium supplements.”

Overweight people did not experience a boost in type 2 diabetes risk from taking selenium.

In the current study, 58 out of 600 participants in the selenium group and 39 out of 602 participants in the placebo group developed type 2 diabetes. After 7.7 years of follow-up, the relative risk rate was approximately 50 percent higher among those randomly selected for the selenium group than among those randomly placed in the placebo group.

The results consistently showed higher risks of disease among participants receiving selenium across subgroups of baseline age, gender, and smoking status. However, the selenium supplements had no impact on the most overweight participants. The risk of developing diabetes tended to be higher in people who had higher blood selenium levels at the start of the study.

Whether a selenium supplement would help or hurt you probably depends on how much selenium you have in your body from your diet. People who eat Brazil nuts already are getting lots of selenium and shouldn't take a supplement.

The lack of increased risk from selenium for those who are overweight suggests that selenium works to boost type 2 diabetes by the same mechanism which fat cells boost that risk. Maybe the fat cells already flip some molecular switches to the same position selenium causes the switches to get set to and therefore when selenium comes along it can't flip the switches.

We need implanted sensors that'll tell us when we are getting too much or two little of each nutrient. We also need nutritional genomics: genetic tests that will tell us what levels of nutrients are ideal for our individual bodies.

By Randall Parker 2007 July 15 02:40 PM  Aging Diet Studies
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Web Site Readers Most Knowledgeable About Politics

It could be that more knowledgeable people are more likely to read the web. But I say down with TV and up with link-rich news sites.

As candidates and pundits look to the Internet in the 2008 presidential campaign, a University of Wisconsin-Madison study shows that Web users during the last election cycle had a more thorough understanding of presidential politics than users of other media.

"We did not find significant links between television news use and factual knowledge, but we did find significant links from both print and online use to factual knowledge in 2004," says the study by graduate student Kajsa Dalrymple and Dietram Scheufele, a UW-Madison journalism professor.

More importantly, however, online newspapers were the only medium that had significant effects on integrated knowledge - the ability of readers to "connect the dots" by combining bits and pieces of knowledge into a meaningful understanding of politics.

Writing web logs and connecting up the dots from newer posts back to older posts and to other sites has changed my mental model of many subjects very substantially. Reading 3 different dead tree newspapers a day would not have done that. I've discarded many incorrect opinions and moved on to better ones. I've been able to get answers to many questions I've had for years (and thanks to those readers who posted some of the answers in comments). So I'm mighty inclined to agree with the conclusions of this report.

Also, TV worthless for news? You bet. TV is there for the Sci Fi channel, the Comedy Channel, and the occasional good show or old movie on other channels. Don't try to treat TV seriously as a news source. You are likely to hurt your brain trying to do that.

People who are engaged in building web logs or cruising through news sites, web logs, policy analysis sites, and other web sources of information are able to find out answers and connect up the dots in ways that readers of the dead tree formats just can't do. The quality and quantity of data on the web keeps improving. Plus, the web provides a way for many specialists to tell us how to think through subjects that otherwise would be hard to navigate. Great voices that would never make it into the public square in the dead tree era find places to reach us on the internet. This is great.

The electronic access to data on web pages is a stepping stone. I treat my blog posts as an extended external memory bank. This extended memory bank makes me think that some day people will sign up to get cybernetic implants of nanodevice memory devices and network connections. The implants will provide people with instant access to large volumes of reference data and analytical tools for chomping through and formatting the data for viewing in their minds.

If we get implants that contain memory then we'll probably put different globs of data into our memory implants depending on what job we are doing. Change jobs or change work tasks at a job and suddenly it becomes time to update the contents of one's memory implant.

By Randall Parker 2007 July 15 01:07 PM  Comm Tech Society
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2007 July 14 Saturday
People With Lots Of Moles Age More Slowly?

Wear your moles proudly, knowing you enjoy a biochemical advantage over your less moley brethren.

People with large numbers of moles may age slower than expected, according to a study from King's. Researchers studied the skin and telomere length (a marker of biological ageing found on all cells in the body) of more than 1800 twins and found that people with a high number of moles had longer telomeres.

The 10 year study from the Twin Research Unit was funded by the Wellcome Trust and is published in the July edition of Cancer Epidemiology Biomarkers & Prevention.

...

The researchers compared telomere length measurements in white cells with the number of moles in more than 1800 female twins (900 pairs of twins) aged between 18 and 79 years. They found that those with high numbers of moles (greater than 100) had longer telomeres than those with very few moles (fewer than 25). The difference between the two mole groups was equivalent to six to seven years of normal ageing (estimated by looking at the average rate of telomere length loss per year in the whole group). This was not affected by other factors such as age, weight or smoking.

These results suggest those with higher numbers of moles may have a delayed ageing as they have longer telomeres and appear to keep their moles for longer. In contrast, people with shorter telomeres have lower numbers of moles and appear to lose them quicker with age - which may be a marker of accelerated ageing.

Lead researcher Dr Veronique Bataille says: ‘The results of this study are very exciting as they show, for the first time, that moley people who have a slightly increased risk of melanoma may, on the other hand, have the benefit of a reduced rate of ageing. This could imply susceptibility to fewer age-related diseases such as heart disease or osteoporosis, for example. Further studies are needed to confirm these findings.'

We need follow-up population studies to measure life expectancy for those who have more and fewer moles. But telomere is a pretty good proxy for rate of aging. On that score see my posts Chronic Stress Accelerates Aging As Measured By Telomere Length and Telomere Length Indicates Mortality Risk.

If the melanin content of moles slows down general body aging why is that? After all, most of the body is not moles. Even most of the skin is not moles. So how could the presence of moles confer much protective effect? Are the moles a proxy for more melanin inside the body?

Could we slow the rate of aging by inducing most of our cells to produce more melanin?

By Randall Parker 2007 July 14 09:02 PM  Aging Studies
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2007 July 12 Thursday
Manhattan To Get Massive Camera Surveillance System

What, me worry? Just think of Manhattan as a massive reality TV show.

New York - The speed with which London's ubiquitous surveillance cameras helped identify would-be bombers has prompted calls for extensive closed-circuit television networks in the US.

In the first such public effort in the US, New York is planning to begin the installation of a similar, permanent system for lower Manhattan by year's end.

In the struggle against terrorism at home, its backers say CCTV is both a forensic tool and a deterrent to all but the most dedicated suicide bombers. Sophisticated imaging technology allows cameras to alert police to unattended packages, zoom in on objects hundreds of feet away, identify license plates, and "mine" archived footage for specific data.

Opponents contend that this very technology is overly intrusive and open to abuse, raising serious constitutional questions. They also note that surveillance cameras not only are helpless against suicide bombings, but also that perpetrators may use video records to try to glorify their acts.

Science fiction writer David Brin argued in his book The Transparent Society that we do not have the option of protecting privacy. We only have a choice over who gets to watch the cameras. Do only employees of government agencies get to watch the video feeds? Or do all people get to watch each other through neighborhood surveillance cameras?

Extremely miniaturized cameras will some day let people plant bugs in offices, cars, houses, and on clothing. People will be able to find out what others say and do when they think no one else is around to observe them. As Mick Jagger put it "These days its all secrecy, no privacy".

By Randall Parker 2007 July 12 11:13 PM  Surveillance Cameras
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New Record In Organic Photovoltaic Efficiency

Only six and half percent efficient in converting sunlight to electricity but the materials used raise the specter of photovoltaics manufacturable from cheap materials.

Using plastics to harvest the energy of the sun just got a significant boost in efficiency thanks to a discovery made at the Center for Polymers and Organic Solids at the University of California, Santa Barbara.

Nobel laureate Alan Heeger, professor of physics at UC Santa Barbara, worked with Kwanghee Lee of Korea and a team of other scientists to create a new "tandem" organic solar cell with increased efficiency. The discovery, explained in the July 13 issue of the journal Science, marks a step forward in materials science.

Tandem cells are comprised of two multilayered parts that work together to gather a wider range of the spectrum of solar radiation -- at both shorter and longer wavelengths. "The result is six and a half percent efficiency," said Heeger. "This is the highest level achieved for solar cells made from organic materials. I am confident that we can make additional improvements that will yield efficiencies sufficiently high for commercial products." He expects this technology to be on the market in about three years.

Heeger co-founded Konarka Technologies a few years ago to commercialize his solar cells research. The press release isn't specific on this point but Konarka might be the company to watch on the subject of commercializing the technology.

If Heeger's team can substantially raise the conversion efficiency and also cheaply manufacture solar cells with this design then solar photovoltaics could finally take off. Solar initially will cut into peak demand. But solar could also provide energy for transportation once cheap high capacity batteries for cars become available.

By Randall Parker 2007 July 12 10:54 PM  Energy Solar
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Americans Against Gas Tax Increases

Over a period of years I've repeatedly argued that fossil fuels will not get phased out by putting high taxes on them. The reason is simple: In countries where voting publics have a lot of influence over their rulers the elected officials will get scared out of enacting more fuel taxes. Scott Rasmussen of polling firm Rasmussen Reports found in a recent poll that an overwhelming majority of Americans oppose higher gasoline taxes.

Eighty-six percent (86%) of Americans oppose a proposal to increase gasoline taxes by 50 cents a gallon. A Rasmussen Reports national telephone survey found that just 8% favor such a tax hike.

Just 17% of Americans believe that such a gasoline tax hike would have a positive impact on the economy. Seventy-nine percent (79%) believe it would have a negative impact, including 64% who believe the impact would be Very Negative.

Some people who fear global warming think fossil fuels taxes are absolutely necessary in order to save the world. But they need to go back to the drawing more and consider other policy options. Higher prices on petroleum products are pretty much a non-starter. For feasible options look at policies that will lead to cheaper competing non-fossil fuels energy sources. Think carrots, not sticks.

The lower classes already are feeling the pinch from the rises in fuel and food prices. They devote larger percentages of their incomes to fuel and food than do those with high incomes and high net worths.

One reason hiking the gas tax generates such strong opposition is that consumers would react to higher gas prices by cutting back on entertainment expenses, vacations, and major purchases. An earlier survey found that half would cut back on groceries if the price of gas jumps a dollar a gallon.

Since the year 1998 gasoline prices in the United States have already more than doubled in inflation-adjusted terms. That's far more than higher gas tax advocates can hope to accomplish in the United States or in most of the other countries with lower gasoline prices.

By Randall Parker 2007 July 12 10:44 PM  Energy Policy
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Gene Therapy Promising Against Pancreatic Cancer

Cancer-causing genetic mutations are best fixed with new genetic programming.

A molecularly engineered therapy selectively embeds a gene in pancreatic cancer that shrinks or eradicates tumors, inhibits metastasis, and prolongs survival with virtually no toxicity, researchers from The University of Texas M. D. Anderson Cancer Center report in the July 9 edition of Cancer Cell.

"This vehicle, or vector, is so targeted and robust in its cancer-specific expression that it can be used for therapy and perhaps for imaging," notes senior author Mien-Chie Hung, Ph.D., professor and chair of M. D. Anderson's Department of Molecular and Cellular Oncology.

The researchers call the system a versatile expression vector - nicknamed VISA. It includes a targeting agent, also called a promoter, two components that boost gene expression in the target tissue, and a payload - in this case a gene known to kill cancer cells. It's all packaged in a fatty ball called a liposome and delivered intravenously.

Researchers are working with M. D. Anderson clinicians to move the system, developed and tested in mouse models of pancreatic cancer, to a Phase I clinical trial.

Future gene therapies will become much more complex and sophisticated. We will likely witness the development of multi-gene gene therapies that are akin to complex computer programs. When injected into each cell the genes and their protein products will sense whether the cell is cancerous and only kill or reprogram cancer cells.

Currently pancreatic cancer is highly lethal.

About 37,000 cases of pancreatic cancer are diagnosed annually in the United States. Early diagnosis is extremely difficult, so the disease is often discovered at a late stage after it already has spread, or metastasized. Fewer than 4 percent of pancreatic cancer patients survive five years after diagnosis, one of the lowest cancer survival rates.

Those horrible odds show why pancreatic cancer patients ought to have the right to try experimental gene therapies without waiting for government approval for therapies. Given a diagnosis of pancreatic cancer I'd want to try any sort of experimental gene therapy or other experimental therapy. With so little time left to live the downsides would be small.

By Randall Parker 2007 July 12 06:42 PM  Biotech Cancer
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2007 July 11 Wednesday
Muscular Men Get More Sex

Here's one big reason why I expect men will eagerly embrace the use of biotechnology to alter body shape.

Frederick and Haselton lead a team that photographed 99 male undergraduates. A panel of independent judges rated the young men on a nine-point scale, with "1" being much less muscular than average and "9" being much more muscular than average. The researchers then asked the men about their sexual histories.

When compared with their less-muscular peers, young men who were more muscular than average were twice as likely to have had more than three sex partners in their lives.

In another study, Frederick and Haselton asked 120 undergraduate males to rate their own physiques on the same scale and then asked them about their sexual histories.

The self-identified muscular men had not only had more sexual partners than their less burly peers, but they were twice as likely to have had brief flings or one-night stands with women. The difference in the number of sexual partners reported by the men who were more muscular than average was also notable: They reported having had an average of four partners, compared with an average of 1.5 partners for men who reported average or below-average muscularity.

In a similar study, Frederick and Haselton asked 60 undergraduate males an additional question: How many affairs had they had with women who already had a boyfriend at the time of the affair? Muscularity mattered here as well. The more muscular individuals were twice as likely as their less well-built peers to have hooked up with someone else's sweetheart.

Women know the muscular men have different personalities and behaviors as compared to the skinnier guys.

Interestingly, women in the study seemed to be on to muscular men. When presented with six standardized silhouettes of men ranging from brawny to slender, 141 undergraduate women consistently identified the most muscular ones as not only less likely to commit but also more volatile and domineering. In the study, the women rated "toned" guys - the physical type two notches down from "brawny" - as the most sexually attractive.

"Moderate muscularity demonstrates that men are in good condition, but they're not so overloaded with testosterone that they are volatile, aggressive and dominant," Frederick said. "Just based on their experiences, women seem to be able to weigh good and bad male traits."

Still, in a study by Frederick and Haselton of 82 college coeds, most women reported that their short-term partners were more muscular than their long-term ones. They characterized their long-term - and presumably less muscular - partners as more trustworthy and romantic than their one-night stands or brief affairs.

I vaguely recall earlier studies that purported to show that upper class women prefer men with less muscles than lower class women.

Will men adjust their body shapes when they change their minds about how long term they want their relationships to be? Time to get married and therefore time to slim down the muscles somewhat in order to appear more caring?

We can expect by using biotechnology future males will have more muscles, less body fat, less gray hair, and less receding hairlines.

By Randall Parker 2007 July 11 12:03 AM  Brain Sexuality
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2007 July 10 Tuesday
Ford To Start Pluggable Hybrid Vehicle Test

At an event to announce a deal with Southern California Edison to field test some plug-in hybrid electric vehicles (PHEVs) Ford CEO Alan Mulally said Ford expects to start selling PHEVs in 5 to 10 years.

"Within five to 10 years we will start to see this technology in our hands," Mr Mulally said on the sidelines of a press event to announce an alliance between Ford and utility Southern California Edison to test 20 rechargeable electric vehicles.

When asked if that meant plug-in hybrids would be available on showroom floors, Mr Mulally said, "Yes. Sure."

5 years puts us in 2012 when the world's demand for oil will have so outpaced production growth that people will be clamoring for a way to escape from our liquid fuels dependency. 10 years is way too late. Why does Mulally think it will take that long to get viable batteries for PHEV use?

By contrast, General Motors Vice Chairman Bob Lutz claimed in March 2007 that GM might manage to get its Volt PHEV into production by 2010.

"We have set an internal target of production in 2010. Whether we can make that or not, this is still kind of an unpredictable program for us," Lutz told reporters on the sidelines of the Geneva auto show.

He added: "We're sort of outside our comfort zone."

Production in 2010 might mean it is for the 2011 model year. GM says the needed lithium ion batteries might not be available till 2012. They aren't sure yet. Even once available that's only one model. But if the price of gasoline keeps going up it could be a very popular model.

GM is initially aiming for a 40 mile range on batteries. For people who have 20 mile commutes you'd have to plug the car in every night to recharge it. That would get tiresome. Depending on where you live plugging in a car at home might be problematic or even impossible. Apartment building residents with a shared lot or street parking probably couldn't plug in their car every night. Electric cars work better for people with driveways and garages.

When will we see batteries that can power cars for 120 or even 200 miles?

By Randall Parker 2007 July 10 11:24 PM  Energy Electric Cars
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2007 July 09 Monday
IEA: Oil Supply Crunch After 2010

Peak Oil anyone? The latest Medium-Term Oil Market Report from the International Energy Agency (IEA) paints a moderately bleak picture on oil availability in the next 5 years.

World oil demand will rise faster than expected to 2012 while production lags, leading to a supply crunch, the International Energy Agency said on Monday.

...

"Despite four years of high oil prices, this report sees increasing market tightness beyond 2010," the IEA said.

"It is possible that the supply crunch could be deferred -- but not by much."

Why is this picture only moderately bleak? They aren't yet predicting a decline in production. But the growing ranks of those affluent enough to buy gasoline and other petroleum products are creating market conditions similar to those we'd expect to see once oil production peaks. The price keeps going up.

Prices will keep rising until demand stops growing. How high will prices have go to go stop oil demand growth? $100 per barrel? $120 per barrel? We are going to find out.

The IEA expects assorted messed up places to stay messed up.

The report assumes no net expansion of capacity from Iran, Iraq and Venezuela and that 500,000 barrels a day of Nigerian oil - shut for a year - will not reopen in the next five.

Iran's own internal demand growth is going to cause Iranian oil exports to decline. So even if Nigeria's government puts down insurgencies an increase there will probably get cancelled out by a decline in Iranian exports. The civil war in Iraq still has some legs too. Though a US pull-out might accelerate the civil war and bring stability sooner.

The IEA projects declining oil extraction from OPEC countries by 2009.

But with forecasts of world economic growth of 4.5pc a year, the report argued that oil demand was likely to soar to 95.8m barrels a day in 2012 from 81.6m barrels this year.

At the same time it predicted production from the international oil cartel Opec would fall, slipping by 2m barrels a day in 2009, and it also cut supply forecasts for non-Opec countries by 800,000 barrels.

I am skeptical of claims that OPEC will substantially increase production. Probably most OPEC members prefer higher prices to higher production. Plus, the ranks of post-peak nations keeps growing. Pemex in Mexico can no longer keep up Mexican oil production.

Petroleos Mexicanos, the state-owned oil monopoly, said crude production fell 6.6 percent in May from a year earlier and dropped to its lowest this year as the company struggles with declining output from its Cantarell field.

We are not lacking in energy so much as we are lacking in energy storage for the types of energy which we can afford to create more of. We can build more nuclear power plants or wind towers to get lots of affordable electricity. But we do not have good enough means to store that electricity for use in transportation.

We need pluggable hybrid electric vehicles (PHEVs) and pure electric cars too. The energy cost per mile of electrically powered travel is much lower than the cost of gasoline to travel the same distance. But for electric vehicles to work out we need much better batteries. Some battery makers (most notably A123Systems) claim they have figured out how to make long lasting and affordable lithium batteries for cars. We are going to find out in 2 or 3 years whether this is the case. Those batteries are going to come not a moment too soon.

Short of PHEVs we have plenty of other ways to adjust: Get cars with smaller engines, diesel engines, or conventional hybrids. Also, live closer to work and take fewer car trips. Also, if you use oil or natural gas for heating then make your house much more energy efficient.

By Randall Parker 2007 July 09 10:55 PM  Energy Fossil Fuels
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2007 July 08 Sunday
Yawning Cools Brain?

Yawning is not contagious for those with cooler brains.

Fifty per cent of people told to breathe normally or through their mouths yawned while watching other people yawn, while none of those told to breathe through their noses yawned. The researchers also found that subjects who held a cold pack to their forehead did not catch yawns from the film, while those who held a warm or room-temperature pack yawned normally (Evolutionary Psychology, vol 5, p 92).

Breathing through your nose cools blood flowing to the brain. Would breathing in through the nose and out through the mouth do a better job of cooling the brain by venting the warmer air from the lungs away from the nose and brain?

Yawning supposedly increases group vigilance. Our hunter ancestors either on stake-out or perhaps manning defense perimeters around camps might have needed to yawn in unison to keep their minds alert to prey or predators. Cooling overheated brains increases their efficiency and hence the yawns.

ALBANY, N.Y. (June 29, 2007) -- The next time you "catch a yawn" from someone across the room, you're not copying their sleepiness, you're participating in an ancient, hardwired ritual that might have evolved to help groups stay alert as a means of detecting danger. That's the conclusion of University at Albany researchers Andrew C. Gallup and Gordon G. Gallup Jr. in a study outlined in the May 2007 issue of Evolutionary Psychology (Volume 5.1., 2007).

The psychologists, who studied yawning in college students, concluded that people do not yawn because they need oxygen, since experiments show that raising or lowering oxygen and carbon dioxide in the blood fails to produce the reaction. Rather, yawning acts as a brain-cooling mechanism. The brain burns up to a third of the calories we consume, and as a consequence generates heat.  According to Gallup and Gallup, our brains, not unlike computers, operate more efficiently when cool, and yawning enhances the brain's functioning by increasing blood flow and drawing in cooler air.

Has the need to dissipate heat slowed the evolution of human intelligence just as heat dissipation problems are slowing the rate of advance of modern computer microprocessor speeds?

These results suggest easy practical ways to boost mental performance:

  1. Turn down office thermostats in summer and winter so that people wear sweaters to keep their torsos warm while keeping their brains cool. Higher mental performance might more than pay back the higher cost of air conditioning in summers. During winters the lower thermostats will save money too.
  2. A cold pack worn on your forehead might boost your mental performance when you are lagging. But how cold is optimal?
  3. When you feel like yawning do not suppress it. In fact, when you feel the slightest desire to yawn you might want to take steps to cool your brain.
  4. Got a cold drink in your hand and your brain lagging? Put the drink up against your forehead.
By Randall Parker 2007 July 08 05:31 PM  Brain Enhancement
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NaS Batteries Used For Large Scale Storage

Sodium-sulfur (NaS) batteries have begun to enter service for large scale stationary electric power storage.

An NaS battery, by contrast, uses a far more durable porcelain-like material to bridge the electrodes, giving it a life span of about 15 years, Mears says. It also takes up about a fifth of the space. Ford Motor pioneered the battery in the 1960s to power early-model electric cars; NGK and Tokyo Electric refined it for the power grid.

Since the 1990s, Japanese businesses have installed enough NaS batteries to light the equivalent of about 155,000 homes, says Brad Roberts, head of the Electricity Storage Association. In the USA, AEP is using the 30-foot-wide by 15-foot-high battery to supply 10% of the electricity needs of 2,600 customers in north Charleston, says Ali Nourai, AEP manager of distributed energy. The battery, which cost about $2.5 million, is charged by generators from the grid at night, when demand and prices are low, and discharged during the day when power usage peaks.

That $2.5 million cost seems high for 10% of the power for 2,600 customers. That's about $960 per customer for something that lasts 15 years. Plus, there's the cost of the electricity lost when it is stored since no battery stores and retrieves electricity with 100% efficiency..

The biggest drawback is price. The battery costs about $2,500 per kilowatt, about 10% more than a new coal-fired plant. That discourages independent wind farm developers from embracing the battery on fears it will drive the wholesale electricity prices they charge utilities above competing rates, says Christine Real de Azua, spokeswoman for the American Wind Energy Association.

It is worth noting that sodium and sulfur are very cheap with sulfur in the tens of dollars per long ton (which is 1016 kg). Sulfur prices dropped a lot in the 1990s and most marketed sulfur come from removal of sulfur from oil and other fossil fuels in refineries. Due to US regulations which went into effect in 2006 to lower sulfur content of diesel fuel refinery sulfur production is up. In a nutshell, there's plenty of cheap sulfur available for making NaS batteries.

Can the prices for large industrial NaS batteries fall? Does anyone understand the processes involved in making NaS batteries and where the big costs come from?

If ways can be found to make NaS batteries cheaply then that would tend to help nuclear, solar, and wind power. Cheap ways to store nuclear electricity would allow nuclear power generated at night to supply peak power needs during the day. This could greatly reduce the demand for peak power generated from dwindling supplies of natural gas. Batteries would also enable solar and wind power to provide electricity when the sun does not shine and the wind does not blow.

Our main problem with limited remaining supplies of fossil fuels is not a simple energy shortage. Rather, our biggest problem is an energy storage shortage. That distinction is of enormous importance.

Oil produces gasoline and diesel fuels which store compactly in cars. Natural gas can get stored in tanks for use by electric utilities to generate electricity at times of peak electricity demand. Coal can get cheaply stored in big containers and carried around in train box cars for use when heat power is needed by steel mills, electric generator plants, and industrial heaters.

We have affordable alternative sources of energy but they do not store well. While photovoltaics are still too expensive nuclear and wind power are affordable without huge changes in lifestyles. Photovoltaics will eventually become affordable as well.

Solar photovoltaics, wind, and nuclear power all produce electricity that is not easily stored for use where and when it is needed. We can switch away from dwindling and increasingly expensive fossil fuels only when we can find ways to store nuclear, wind, and solar power. Therefore the development of better, cheaper, and longer lasting batteries is essential for the migration away from fossil fuels.

By Randall Parker 2007 July 08 11:39 AM  Energy Batteries
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2007 July 07 Saturday
Biomass Energy To Drive Up Food Prices In Next 10 Years

Big food price increases are coming in the next 10 years.

The study predicts prices will rise by between 20% and 50% by 2016.

"Growing use of cereals, sugar, oilseeds and vegetable oils to satisfy the needs of a rapidly increasing biofuel industry is one of the main drivers in the outlook," said the report, which was co-written by the UN Food and Agriculture Organisation (FAO).

The OECD-FAO report sees the use of agricultural products to make fossil fuel substitutes as the biggest long term cause of increased food prices.

The OECD-FAO Agricultural Outlook 2007-2016 says temporary factors such as droughts in wheat-growing regions and low stocks explain in large measure the recent hikes in farm commodity prices.  But when the focus turns to the longer term, structural changes are underway which could well maintain relatively high nominal prices for many agricultural products over the coming decade.

Reduced crop surpluses and a decline in export subsidies are also contributing to these long-term changes in markets. But more important is the growing use of cereals, sugar, oilseed and vegetable oils to produce the fossil fuel substitutes, ethanol and bio-diesel. This is underpinning crop prices and, indirectly through higher animal feed costs, also the prices for livestock products.

My guess is this report probably understates the scale of the problem because they are probably still assuming that oil production can keep up with growing demand.

Peter Brabeck, chairman of Nestle, which is the world's largest food company, told the Financial Times that he sees an extended period of high food prices due to the industrialization of India and China, world population growth, and the use of agriculture to make biomass energy.

Peter Brabeck, chairman of the world’s largest food company, said rises in food prices reflected not only temporary factors but also long-term and structural changes in supply and demand.

“They will have a long-lasting impact on food prices,” he told the Financial Times during a visit to China.

The US. Bureau of Labor Statistics also sees rising food prices.

"We are going to see grocery store prices show one of the most rapid increases in the last 15 years or so," said Patrick Jackman, an economist at the U.S. Bureau of Labor Statistics.

....

The Economic Research Service of the U.S. Department of Agriculture expects food prices to go up another 4 percent this year. The average increase over the past decade has been 2.5 percent.

The US Bureau of Labor Statistics says food prices are going up 50% faster than the overall rate of inflation.

The Consumer Price Index for all food has increased 3.9 percent — about 50 percent more than the 2.6 percent rate of inflation — since a year ago, according to the Bureau of Labor Statistics. Egg prices have taken the greatest jump, and have increased 2.9 percent in May and 29.6 percent since May 2006. Milk prices are 7.5 percent above levels a year ago and have jumped 2.2 percent in May. Overall, dairy prices have increased 3.5 percent in the past year and increased 0.8 percent between April and May. Poultry prices are up 0.8 percent in May and 5.7 percent for the year. Pork prices jumped 3.2 percent in May, and 3.9 percent in a year. Beef prices are up 5.8 percent over last year

If you think you've seen big increases in food prices in the last 3 months you are correct.

Retail food prices jumped 5% over the past three months. Tom Thieding with the Wisconsin Farm Bureau Federation says the 20 items in their monthly Market Basket Survey cost $50.33 at the end of June compared to $47.85 at the end of March.

The more developed countries could do themselves and the Third World a big favor if they made a much bigger effort to get birth control tools into the hands of the poor people all over the world. A more rapid rate of decrease of Third World fertility would reduce the demand for food and fuel and also reduce the strain on habitats and other species.

We could reduce ecological footprints of developed country populations by a number of methods and in the process lower food and fuel prices. First off, make bigger efforts to systematically implement measures that increase fuel efficiency. See the McKinsey & Company study from May 2007: Curbing Global Energy Demand Growth: The Energy Productivity Opportunity.

Second, we could accelerate the development of battery technologies that will enable a shift away from liquid fuels for transportation. Reduce the demand and justification for bioethanol and biodiesel by powering cars with electricity from nuclear, wind, and solar power.

Third, adopt policies that will accelerate the technological development of nuclear and solar power to lower their costs and enable them to displace fossil fuels and biomass fuels.

By Randall Parker 2007 July 07 04:02 PM  Energy Biomass
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Humans Use Nearly A Quarter Of World Biomass?

A recent research report published in the Proceedings of National Academy of Sciences USA by a group of German and Austrian researchers find that humans are already using a quarter of the world's biomass.

Human appropriation of net primary production (HANPP), the aggregate impact of land use on biomass available each year in ecosystems, is a prominent measure of the human domination of the biosphere. We present a comprehensive assessment of global HANPP based on vegetation modeling, agricultural and forestry statistics, and geographical information systems data on land use, land cover, and soil degradation that localizes human impact on ecosystems. We found an aggregate global HANPP value of 15.6 Pg C/yr or 23.8% of potential net primary productivity, of which 53% was contributed by harvest, 40% by land-use-induced productivity changes, and 7% by human-induced fires. This is a remarkable impact on the biosphere caused by just one species. We present maps quantifying human-induced changes in trophic energy flows in ecosystems that illustrate spatial patterns in the human domination of ecosystems, thus emphasizing land use as a pervasive factor of global importance. Land use transforms earth's terrestrial surface, resulting in changes in biogeochemical cycles and in the ability of ecosystems to deliver services critical to human well being. The results suggest that large-scale schemes to substitute biomass for fossil fuels should be viewed cautiously because massive additional pressures on ecosystems might result from increased biomass harvest.

One could dispute this result. How one measures biomass usage will affect how high a figure will be assigned to human usage. But consider for example the world's fisheries. We are cutting back on the sizes of the world's fisheries. One could argue that since we are using such a large fraction of all the fish we are effectively using all the algae and other microorganisms in the food chains of those fish which we eat.

If we plant lawns and fruit trees in our yards then are we appropriating that biomass for our use? Seems like it. If we didn't plant those lawns other plants would grow there and other species would make use of those plants in ways that we currently prevent (e.g. we battle to keep out gophers).

This result illustrates why I think biomass energy is a bad idea. We do not have large amounts of land as yet unused. We should avoid development of yet more ways to make land useful. Even without the development of biomass energy I expect both human population growth and human industrialization to increase human land use to an extent that wipes out lots of species. Human continue to greatly shrink the wilds with no end to that shrinkage in sight.

Industrialization will continue to raise the demand for timber. That will shift more lands from their natural state into forest monocultures. Industrialization will continue to increase the size of dwellings and of lawn areas around houses. This will decrease the amount of land available for nature. Rising living standards will increase the buying power of people who like meat. This will cause a shift of more lands toward agriculture to raise grain crops and for grazing.

The human population is about 6.6 billion people and the US Census Bureau projects it might reach 9.4 billion by 2050. If the Chinese government loses the ability to enforce its "One Child" policy then the world's population could go much higher. Also, the development of cures for major diseaes and rejuvenation therapies will drastically cut the death rate in industrialized countries.

Nanotech replications will make solar power and goods production extremely cheap. Therefore hundreds of millions or even billions of humans will gain the ability to use huge amounts of land just for massive mansions.

The full paper (PDF) is available with open access.

By Randall Parker 2007 July 07 09:17 AM  Trends Habitat Loss
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2007 July 06 Friday
Prius Appeals As Personal Statement

The other hybrids do not sell as well because they do not shout "I'm a hybrid".

In fact, more than half of the Prius buyers surveyed this spring by CNW Marketing Research of Bandon, Ore., said the main reason they purchased their car was that “it makes a statement about me.”

Only a third of Prius owners cited that reason just three years ago, according to CNW, which tracks consumer buying trends.

“I really want people to know that I care about the environment,” said Joy Feasley of Philadelphia, owner of a green 2006 Prius. “I like that people stop and ask me how I like my car.”

This is why better home insulation does not get the money spent on it that hybrids get. Your neighbors can't see that you spent thousands of dollars on R-60 walls and R-90 attics. Also, your house probably doesn't get seen by nearly as many people as see your car tooling down busy roads and highways.

This presents a business challenge: What sort of service would allow people to upgrade their houses to extreme levels of fuel efficiency in such a way that the huge reduction in heating and air conditioning energy usage would be highly visible? Solar panels on the roof are visible. But the most cost effective ways to decrease energy involve changes inside walls and attics and doors and windows.

By Randall Parker 2007 July 06 12:11 AM  Energy Transportation
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2007 July 05 Thursday
Greenland Warmer Half Million Or So Years Ago

DNA samples found under a Greenland ice sheet suggest that Greenland was much warmer more recently than previously believed.

A team of international researchers has collected the oldest ever recovered DNA samples and used them to show that Greenland was much warmer at some point during the last Ice Age than most people have believed.

The ancient DNA was discovered at the bottom of a two kilometer thick ice sheet and came from the trees, plants and insects of a boreal forest estimated to be between 450,000 and 900,000 years-old. Previously, the youngest evidence of a boreal forest in Greenland was from 2.4 million years ago.

Natural trends will some day make Greenland much warmer than it is today.

Southern Greenland used to really be green.

The DNA samples suggest the temperature of the southern Greenland boreal forests 450,000 to 900,000 years-ago was probably between 10C in summer and -17C in winter. Also, the reduced glacier cover in that region means the global ocean was probably between one and two metres higher during that time compared to current levels.

One wonders whether the ability to recover such old DNA will enable the recreation of long lost species.

Researchers analysed ice cores from a number of locations in Greenland, including Dye 3 in the south of the country. From the base of the 2km deep Dye 3 core, they were able to extract what they believe is likely to be the oldest authenticated DNA obtained to date.

By analysing these DNA samples, the researchers identified a surprising variety of plant and insect life, including species of trees such as alder, spruce, pine and members of the yew family, as well as invertebrates related to beetles, flies, spiders, butterflies and moths. The researchers believe that the samples date back to between 450,000 and 800,000 years ago.

Suppose humanity still exists the next time natural trends cause a major warming of the planet. Should humans seek to prevent the natural warming? Suppose the natural warming will be greater than the human-caused warming that some climate models predict as a result of human burning of fossil fuels. Should we intervene to stop a natural trend that will cause rising ocean levels and expansion and contraction of many ecological niches? Should we seek to save the polar bear from extinction due to natural climate change?

By Randall Parker 2007 July 05 11:36 PM  Climate Trends
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Organic Tomatoes Contain More Flavonoids

An unsurprising result:

According to the new findings, levels of the flavonoids quercetin and kaempferol were found to be on average 79 and 97 per cent higher, respectively, in organic tomatoes. Flavonoids such as these are known antioxidants and have been linked to reduced rates of cardiovascular disease, some forms of cancer and dementia, says Alyson Mitchell, a food chemist who led the research at the University of California, Davis.

The quality of tomatoes varies enormously from pale unmoist tomatoes sold in supermarkets in the winter to the best stuff from sandy acidic soil picked fully ripe in summer. Of course this stuff varies greatly in how much flavonoids it contains.

But the effect of organic farming might not apply to all organically farmed tomatoes.

That meant growers didn't need to use as much compost to keep nitrogen levels high. And without that extra boost of growth-promoting nitrogen, plants seemed to devote more energy to producing flavonoids.

The findings don't necessarily mean that all organic tomatoes would contain more flavonoids, Mitchell stressed, because soils and growing methods on different farms could vary tremendously.

My own experience with garden-grown versus farmed tomatoes is that home grown tomatoes taste much better and look more colorful than most tomatoes sold in stores.. Either soil conditions or types of tomatoes used or the ability to let the tomatoes fully ripen on the vine in gardens might account for the difference. My guess is that the tangier and more colorful tomatoes have more beneficial chemicals.

By Randall Parker 2007 July 05 11:26 PM  Aging Diet Studies
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2007 July 04 Wednesday
Stress Activates Weight Gain In Mice

If you want to stay skinny avoid getting too stressed out.

Washington, D.C. − In what they call a “stunning research advance,” investigators at Georgetown University Medical Center have been able to use simple, non-toxic chemical injections to add and remove fat in targeted areas on the bodies of laboratory animals. They say the discovery, published online in Nature Medicine on July 1, could revolutionize human cosmetic and reconstructive plastic surgery and treatment of diseases associated with human obesity.

While the ability to lose fat has obvious value for everyone fighting a bulging wasteline the ability to gain fat in specific locations has cosmetic value for women especially.

Investigators say these findings may also, over the long-term, lead to better control of metabolic syndrome, which is a collection of risk factors that increase a patient’s chances of developing heart disease, stroke, and diabetes. Sixty million Americans were estimated to be affected by metabolic syndrome in 2000, according to a study funded by the Centers for Disease Control in 2004.

In the paper, the Georgetown researchers describe a mechanism they found by which stress activates weight gain in mice, and they say this pathway − which they were able to manipulate − may explain why people who are chronically stressed gain more weight than they should based on the calories they consume.

This pathway involves two players − a neurotransmitter (neuropeptide Y, or NPY) and the receptor (neuropeptide Y2 receptor, or Y2R) it activates in two types of cells in the fat tissue: endothelial cells lining blood vessels and fat cells themselves. In order to add fat selectively to the mice they tested, researchers injected NPY into a specific area. The researchers found that both NPY and Y2R are activated during stress, leading to apple-shape obesity and metabolic syndrome. Both the weight gain and metabolic syndrome, however, were prevented by administration of Y2R blocker into the abdominal fat.

In the future most body sculpting will not require plastic surgery. Injections of hormones, gene therapies, and bioengineered cells will become the biosculpting equivalents of a sculpting artist's drills and saws. Cells will get ordered to divide or kill themselves or change the color of pigment they produce. Gene therapies will deliver genes to make enzymes that repair aged cells. The therapies will make you look younger and will also make your body parts operate at a more youthful level of performance.

By Randall Parker 2007 July 04 10:38 PM  Brain Appetite
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Telomerase Elimination For Rejuvenation Problematic

In order to limit the number of times that cancer cells can divide biogerontologist Aubrey de Grey has proposed elimination of the gene for telomerase in stem cells introduced into aged bodies. He calls this Whole-body Interdiction of Lengthening of Telomeres (WILT). Well, with a new report about telomerase enzyme published in the Proceedings of the National Academies of Sciences USA that proposal seems problematic. According to this new result telomerase does not just lengthen the caps on the ends of chromosomes.

Telomerase is a cellular reverse transcriptase that extends one strand (the G-strand) of the telomere terminal repeats. Aside from this role in telomere length maintenance, telomerase has been proposed to serve a protective function at chromosome ends, although this is not well understood mechanistically. Earlier analysis suggests that, in the pathogenic yeast Candida albicans, the catalytic reverse transcriptase subunit of telomerase (TERT/EST2) can protect telomeres against nucleolytic degradation. In this report we demonstrate that the RNA component (TER1) has a similar function; in addition to complete loss of telomerase activity and progressive telomere attrition, the ter1-ΔΔ strains manifested a dramatic increase in the amount of G-strand overhangs, consistent with aberrant degradation of the complementary C-strand. We also demonstrate that a catalytically incompetent EST2 protein can suppress such overhang accumulation in the est2ΔΔ mutant to the same extent as the wild-type protein. Altogether, our data support the notion that the Candida telomerase core components mediate a protective function through a mechanism that is independent of its catalytic activity.

If telomerase is keeping chromosomes stable then taking away telomerase could cause more things to go wrong sooner. I've never been enthusiastic about WILT because we need a cure for cancer for all our cells that do not already have telomerase knocked out in them. We have lots of cells all over our bodies that are getting older and at greater risk of becoming cancerous. Short of replacing our entire bodies WILT will not eliminate the risk of death from cancer.

Fortunately, I expect cancers will become very curable. We'll develop immuno-therapies, gene therapies, cell therapies, and even nanobots that will seek out and selectively kill cancer cells. Falling costs and greater sensitivity of genetic tests and cellular tests will allow us to understand in great detail all the myriad ways in which cancer cells differ from normal cells. We will develop much more powerful tools for targeting cells based on these differences. Cancer is curable.

By Randall Parker 2007 July 04 05:43 PM  Rejuvenation Cancer
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2007 July 03 Tuesday
Dark Chocolate Lowers Blood Pressure

Every time I write a post about the health benefits of chocolate I eat some chocolate while writing the post. This time was no exception. How often does science tell you to do exactly what you want to do? (usually science tells you to eat vegetables you aren't excited to eat)

Eating about 30 calories a day of dark chocolate was associated with a lowering of blood pressure, without weight gain or other adverse effects, according to a study in the July 4 issue of JAMA.

Previous research has indicated that consumption of high amounts of cocoa-containing foods can lower blood pressure (BP), believed to be due to the action of the cocoa polyphenols (a group of chemical substances found in plants, some of which, such as the flavanols, are believed to be beneficial to health). “A particular concern is that the potential BP reduction contributed by the flavanols could be offset by the high sugar, fat and calorie intake with the cocoa products,” the authors write. The effect of low cocoa intake on BP is unclear.

Dirk Taubert, M.D., Ph.D., of University Hospital of Cologne, Germany, and colleagues assessed the effects of low regular amounts of cocoa on BP. The trial, conducted between January 2005 and December 2006, included 44 adults (age 56 through 73 years; 24 women, 20 men) with untreated upper-range prehypertension (BP 130/85 – 139/89) or stage 1 hypertension (BP 140/90 – 160/100). Participants were randomly assigned to receive for 18 weeks either 6.3 g (30 calories) per day of dark chocolate containing 30 mg polyphenols or matching polyphenol-free white chocolate.

That 6.3 grams of dark chocolate is about one and a third teaspoon or almost half a tablespoon of chocolate.

The researchers found that from baseline to 18 weeks, dark chocolate intake reduced average systolic BP by −2.9 (1.6) mm Hg and diastolic BP by −1.9 (1.0) mm Hg without changes in body weight, plasma levels of lipids or glucose. Hypertension prevalence declined from 86 percent to 68 percent.

The white chocolate didn't help any. You have to eat the dark stuff, the darker and less sweet the better.

By Randall Parker 2007 July 03 10:57 PM  Aging Diet Studies
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2007 July 01 Sunday
Sun No Guarantee Of Adequate Blood Vitamin D

A population of adults in Hawaii who averaged about 29 hours a week of sun exposure still mostly did not have an optimal amount of vitamin D in their blood.

Participants: The study population consisted of 93 adults (30 women and 63 men) with a mean (SEM) age and body mass index of 24.0 yr (0.7) and 23.6 kg/m2 (0.4), respectively. Their self-reported sun exposure was 28.9 (1.5) h/wk, yielding a calculated sun exposure index of 11.1 (0.7).

Main Outcome Measures: Serum 25(OH)D concentration was measured using a precise HPLC assay. Low vitamin D status was defined as a circulating 25(OH)D concentration less than 30 ng/ml.

Results: Mean serum 25(OH)D concentration was 31.6 ng/ml. Using a cutpoint of 30 ng/ml, 51% of this population had low vitamin D status. The highest 25(OH)D concentration was 62 ng/ml.

I wonder what their racial and age breakdown was. First off, darker skinned people will make less vitamin D from a given amount of sun exposure. Second, as skin ages it very likely becomes less efficient at harnessing sun to make vitamin D.

Another report on this study says only about 22 of those hours were without sunscreen on average. But 22 hours a week is a lot more than people get in colder climates except maybe during the summer times.

Another recent study by Paul Lips and colleagues using subjects from the Longitudinal Aging Study Amsterdam found that blood vitamin D below 20 ng/ml was associated with a more rapid decline in physical performance among the elderly.

Conclusions: Serum 25-OHD concentrations below 20 ng/ml are associated with poorer physical performance and a greater decline in physical performance in older men and women. Because almost 50% of the population had serum 25-OHD below 20 ng/ml, public health strategies should be aimed at this group.

This doesn't prove a cause and effect. It could be that sicker people get out into the sun less. Or people who get out more exercise more and therefore do a better job of maintaining muscle mass as they age.

Another study from 2005 found that even women receiving anti-osteoporosis therapy do not have enough vitamin D.

Conclusions: More than half of North American women receiving therapy to treat or prevent osteoporosis have vitamin D inadequacy, underscoring the need for improved physician and public education regarding optimization of vitamin D status in this population.

Think about what this says about doctors. These women have crumbling bones. Did the doctors prescribe vitamin D to boost their deficient blood vitamin D levels? Probably not. Yet vitamin D is essential for good bone health.

By Randall Parker 2007 July 01 05:49 PM  Aging Diet Studies
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Nuclear Rocket Proposed For Moon Return

Steven Howe, director of Idaho National Laboratory's Center for Space Nuclear Research, says a nuclear upper stage rocket could carry cargo from Earth's orbit to the moon more cheaply than a chemical rocket.

Howe envisions using a nuclear engine similar to one designed and tested in the 1960s called Nuclear Engine for Rocket Vehicle Application (NERVA). In the NASA-funded NERVA design, hydrogen gas is heated by nuclear reactions in a uranium reactor and expelled to produce thrust.

The higher efficiency of such an engine means almost 29 tonnes of cargo could be delivered to the Moon in a single Ares V launch, compared to 21 tonnes with the non-nuclear version. This would allow a 250-tonne lunar base to be constructed with only nine rather than 12 Ares V launches, Howe says..

Howe estimates that even with the added costs of developing the nuclear rocket that the total cost savings would be $1.5 to $2 billion. Of course, once the rocket gets designed and built and pays back its cost on the initial moon trips the cost savings would be even greater for additional trips to the moon or elsewhere.

Chemical rockets are a dead end. The chemicals weigh too much for the amount of energy they contain. To lower space travel costs we need to move beyond chemical rockets. Nuclear designs could work outside of Earth's atmosphere. If the US government wants to seriously pursue space exploration then nuclear designs warrant serious consideration.

By Randall Parker 2007 July 01 03:24 PM  Space Exploration
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High Oil Prices Drive Shift To Trains

Trains use a lot less energy than trucks to move goods the same distance.

As the price of oil climbed 37 percent in five months from Jan. 18, shares of Union Pacific, based in Omaha, Neb., the biggest U.S. railroad company, gained 24 percent. Shares of CSX, based in Jacksonville, Fla., the third-largest, rose 26 percent.

"Railroads typically are about three times more fuel-efficient than trucks," said Jason Seidl, a New York-based analyst at Credit Suisse. Higher fuel prices "will drive up the differential."

...

While trucks offer a cost advantage on most short hauls and can reach places not accessible by rail, they consume about four times as much fuel to move a shipment as a train does, according to U.S. Energy Department data. Shipping rates are about five times higher for trucks than trains, said Amin of TCI, which is the fifth-largest shareholder of CSX, according to Bloomberg data.

Warren Buffett's Berkshire Hathaway now owns 11% of Burlington Northern. My interpretation: The smart money has begun to bet on Peak Oil happening sooner rather than later.

The energy advantage of trains leaves me with a question: Once oil production peaks how much of freight shipments will shift from trucks to trains? I live in a town that has a rail line passing through it that runs up and down the West Coast. But the train does not unload or load here. The containers just pass on through. How high would the price of oil have to get before it would make sense to build container box loaders and unloaders in towns with 100,000 or 200,000 populations? How does the cost in time, equipment, and labor for moving the containers onto tractor trailers compare to the cost saved on running truck engines to move cargo, say, 100 miles?

What I also wonder: Will we see a population shift toward train lines because the difference in cost of shipping will be substantial enough to make life near container unloader facilities cheap enough to influence moving decisions? Anyone have real cost numbers to plug into a consideration of this question?

I'm trying to figure out how soon world oil production will peak, how rapidly oil production will decline, and how high oil prices will rise as a consequence. The price peak of oil once oil production starts declining is the most interesting question. Some will argue for $150 and $200 per barrel oil. But I expect oil substitutes and conservation measures to put upper limits in prices that make $200 oil out of the question.

I could be wrong on the upper limits on oil prices for one reason that really bothers me: The US dollar could decline so much against other currencies that they'll see much smaller oil price rises that they'll be able to bid up the price of oil much higher in dollar terms.

T. Boone Pickens thinks world oil production has already peaked.

Q: Energy seems to be on everyone's mind these days, and you're an acknowledged expert. What do you see happening with oil and gasoline prices?

BOONE PICKENS: I think you'll see $80 oil before the end of the year. There's no question in my mind that oil has peaked. If you've already peaked, you'll start to decline. Can you replace it? Probably not. What happens then? The supply goes down, demand goes up, and price goes up. It will be a case of, how much does the consumer want to pay to get gasoline?

You could argue that we haven't hit Peak Oil yet. I'm not certain on this point. But a continued rise in energy prices due to growth in the world economy combined with rising costs of oil extraction make continued price rises likely. ConocoPhillips chairman and CEO James J. Mulva told the New York Times that he expects to see energy prices continue to rise.

Q. Drivers are concerned about rising gas prices. What can American drivers expect to pay at the pump in the short term, medium term and long term?

A. I would like to see gasoline prices decline. However, I believe that is somewhat unrealistic. Energy costs are going to continue to escalate as a result of the cost it takes to add new resources of energy.

Higher oil prices will make people buy smaller cars, take fewer trips, drive scooters, live closer to jobs, take jobs closer to home, and take other steps to cut their oil usage. How rapidly will the adjustments take place?

Existing fields are in decline. Mulva says to meet future demand with oil will require bringing more oil into production than is currently being produced.

June 12, 2007 -- To meet a projected 40% growth in demand for oil in just over two decade, ConocoPhillips said June 11 that "vast new areas" will have to be opened. Its CEO James Mulva said: "By 2030 we would have to bring on line 105 million barrels a day of new production. To meet this challenge, vast new areas will need to be opened and explored."

That will not happen. We need a massive effort to build nuclear power plants, better battery technology to enable nuclear to power vehicles, and much cheaper solar power.

Once big money becomes convinced that high oil prices (north of $50 per barrel) are a permanent fixture I expect a huge rush to invest in coal-to-liquid (CTL) plants. The CTL plants will put a lid on diesel fuel prices. But they'll do so at an environmental cost. If we scale up nukes faster then we can shift more of the economy away from fossil fuels and reduce the size of the coal surge.

By Randall Parker 2007 July 01 02:42 PM  Energy Transportation
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