2007 May 31 Thursday
Coal Industry Wants Big Subsidies For Transportation

The coal industry wants government subsidies to start producing liquid fuels for transportation.

WASHINGTON, May 28 — Even as Congressional leaders draft legislation to reduce greenhouse gases linked to global warming, a powerful roster of Democrats and Republicans is pushing to subsidize coal as the king of alternative fuels.

Prodded by intense lobbying from the coal industry, lawmakers from coal states are proposing that taxpayers guarantee billions of dollars in construction loans for coal-to-liquid production plants, guarantee minimum prices for the new fuel, and guarantee big government purchases for the next 25 years.

The United States has 27% of the world's coal. Russia has 17% and China 13%. Coal can get turned into gaseous and liquid fuels. Tim Appenzeller, a writer for the National Geographic, says if we burned all the world's coal we'd increase atmospheric CO2 by a full order of magnitude.

Coal already generates about half of US electricity and that percentage might rise in coming decades. The coal industry wants big money to encourage greater use of coal for transportation as well. That would almost double CO2 emissions per mile driven.

Among the proposed inducements winding through House and Senate committees: loan guarantees for six to 10 major coal-to-liquid plants, each likely to cost at least $3 billion; a tax credit of 51 cents for every gallon of coal-based fuel sold through 2020; automatic subsidies if oil prices drop below $40 a barrel; and permission for the Air Force to sign 25-year contracts for almost a billion gallons a year of coal-based jet fuel.

I would rather spend the same amount of money on photovoltaic, nuclear, and battery research. Cheap polluting coal is the temptation we need to find ways to avoid. We shouldn't spend tax dollars to embrace it.

If we hit "Peak Oil" 5 years from now will CO2 emissions rise more or less rapidly? That depends on what we replace the oil with. If we shift toward coal-to-liquid then CO2 emissions would skyrocket.

For electricity coal use is growing more rapidly in China than in the US. China's coal use might double in the next 20 to 25 years while US use goes up only 50%. But a shift toward coal use for transportation would make coal use go up even more rapidly.

We need cheaper nuclear and solar photovoltaic power. Add in much cheaper and higher energy density batteries and we could shift transportation away from fossil fuels. That's the future I'd like to see.

By Randall Parker 2007 May 31 08:38 PM  Energy Policy
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2007 May 29 Tuesday
Epicatechin And Exercise As Memory Boosters?

Epicatechin and exercise boost memory in mice.

WASHINGTON, DC May 29, 2007 – A natural compound found in blueberries, tea, grapes, and cocoa enhances memory in mice, according to newly published research. This effect increased further when mice also exercised regularly.

"This finding is an important advance because it identifies a single natural chemical with memory-enhancing effects, suggesting that it may be possible to optimize brain function by combining exercise and dietary supplementation," says Mark Mattson, PhD, at the National Institute on Aging.

The compound, epicatechin, is one of a group of chemicals known as flavonols and has been shown previously to improve cardiovascular function in people and increase blood flow in the brain. Flavonols are found in some chocolate. Henriette van Praag, PhD, of the Salk Institute, and colleagues there and at Mars, Inc., showed that the combination of exercise and a diet with epicatechin also promoted structural and functional changes in the dentate gyrus, a part of the brain involved in the formation of learning and memory. The findings, published in the May 30 issue of The Journal of Neuroscience, suggest that a diet rich in flavonols may help reduce the incidence or severity of neurodegenerative disease or cognitive disorders related to aging.

You can also get epicatechin from fruits and tea. Anyone know a good table listing the epicatechin content of many foods?

By Randall Parker 2007 May 29 11:09 PM  Aging Diet Brain Studies
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Computers Beat Humans At Facial Recognition

Computers now outperform humans in recognizing faces.

For scientists and engineers involved with face-recognition technology,the recently released results of the Face Recognition Grand Challenge--more fully, the Face Recognition Vendor Test (FRVT) 2006 and the Iris Challenge Evaluation (ICE) 2006--have been a quiet triumph. Sponsored by the National Institute of Standards and Technology (NIST), the match up of face-recognition algorithms showed that machine recognition of human individuals has improved tenfold since 2002 and a hundredfold since 1995. Indeed, the best face-recognition algorithms now perform more accurately than most humans can manage.

I expect artificial intelligence to come about as a result of advances made to solve many practical computing problems. Computer face recognition, like computer voice recognition, has many useful applications. Attempts to meet market needs will push development of algorithms to solve an increasing variety of the problems that human minds can solve. Artificial intelligence will become easy to create once we reach a critical mass of accumulated algorithms that replace humans for performing many tasks.

By Randall Parker 2007 May 29 10:13 PM  Artificial Intelligence
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2007 May 28 Monday
Exercise Partially Restores Aged Muscle Gene Profiles

A research report published in Plos One (open source - you can read it) finds that 6 months of resistance training exercise changes gene expression patterns in aged muscle to look more like youthful muscle.

Human aging is associated with skeletal muscle atrophy and functional impairment (sarcopenia). Multiple lines of evidence suggest that mitochondrial dysfunction is a major contributor to sarcopenia. We evaluated whether healthy aging was associated with a transcriptional profile reflecting mitochondrial impairment and whether resistance exercise could reverse this signature to that approximating a younger physiological age. Skeletal muscle biopsies from healthy older (N = 25) and younger (N = 26) adult men and women were compared using gene expression profiling, and a subset of these were related to measurements of muscle strength. 14 of the older adults had muscle samples taken before and after a six-month resistance exercise-training program. Before exercise training, older adults were 59% weaker than younger, but after six months of training in older adults, strength improved significantly (P<0.001) such that they were only 38% lower than young adults. As a consequence of age, we found 596 genes differentially expressed using a false discovery rate cut-off of 5%. Prior to the exercise training, the transcriptome profile showed a dramatic enrichment of genes associated with mitochondrial function with age. However, following exercise training the transcriptional signature of aging was markedly reversed back to that of younger levels for most genes that were affected by both age and exercise. We conclude that healthy older adults show evidence of mitochondrial impairment and muscle weakness, but that this can be partially reversed at the phenotypic level, and substantially reversed at the transcriptome level, following six months of resistance exercise training.

The reversal isn't complete. Aged muscles are still weaker and their gene expression patterns are still different than youthful patterns.

We need to know why the aged muscles do not fully regain youthful strength when exercised. Perhaps losses of muscle cells through cell death leaves too few muscle cells to regain youthful strength. Or maybe limitations in aged vasculature prevents enough oxygen and nutrients from getting through.

The resistance training exercise does not simply substitute for a lower level of exercise in the elderly. Younger control subjects who did not exercise much had youthful gene expression profiles even though they didn't exercise much.

It is possible that our observation of a reversal of the mitochondrial based aging signatures could indicate that the response to exercise training was solely due to lower habitual exercise in the older adults. Arguing against this is the fact that the current study was specifically designed to avoid this confounder by selecting healthy, active, disease-free older adults and comparing them to similarly active younger adults (relatively inactive for age). In the future, it will be important to determine whether long-term or life-long exercise in humans can attenuate the transcriptome signature of aging using cross-sectional sampling in Masters athletes.

We need a gene therapy delivery mechanism that can deliver replacement mitochondrial DNA (mtDNA) into muscle tissues. Such a therapy would help us answer the question of whether accumulated mtDNA damage is a substantial cause of muscle aging. I hope the answer is "yes" because methods to replace mtDNA will be much easier to develop than methods to replace nuclear DNA (i.e. the DNA in chromosomes in the nucleus of cells). Why the difference in difficulty? The nucleus contains over 2.9 billion base pairs of DNA whereas the mtDNA contains about 15,000 base pairs. So development of methods to deliver replacement mtDNA should be a relatively simpler task.

By Randall Parker 2007 May 28 10:43 PM  Aging Exercise Studies
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Moral Reasoning Done To Justify Intuitions?

People reach moral judgments intuitively and then create rationalizations to explain their subconscious conclusions.

In a review to be published in the May 18 issue of the journal Science, Jonathan Haidt, associate professor of psychology at the University of Virginia, discusses a new consensus scientists are reaching on the origins and mechanisms of morality. Haidt shows how evolutionary, neurological and social-psychological insights are being synthesized in support of three principles:

1) Intuitive primacy, which says that human emotions and gut feelings generally drive our moral judgments;

I see a lot of moral rationalizing where people try to come up with rational arguments to justify moral judgments they made for other reasons. How can I tell? When presented with flaws in logical reasoning about morality most people try to restructure their logic to keep the same conclusion rather than change to a different conclusion.

It perhaps says something about the lingering effects of the Enlightenment period in the West that most people feel a need to construct rational-sounding arguments to justify their moral beliefs. Or maybe the rationalizing serves the primary purpose of building arguments to persuade others?

2) Moral thinking if for social doing, which says that we engage in moral reasoning not to figure out the truth, but to persuade other people of our virtue or to influence them to support us; and

I agree with this point:

3) Morality binds and builds, which says that morality and gossip were crucial for the evolution of human ultrasociality, which allows humans - but no other primates - to live in large and highly cooperative groups.

It is worth noting in this context that people who join political parties choose most of their political positions after they join their party. They find out from other members what position they should take on a variety of issues. My interpretation: Political parties are like tribes and people behave in them in ways similar to how earlier humans behaved in tribes. People choose a political party which seems to share some values and styles of cognition. Then they demonstrate loyalty to their political tribe by subscribing to its myths.

"Putting these three principles together forces us to re-evaluate many of our most cherished notions about ourselves," says Haidt, whose own research demonstrates that people generally follow their gut feelings and make up moral reasons afterwards.

Well, it only forces some of us to re-evaluate. Others are happy to ignore anything that challenges the myths they want to believe.

Conservatives have more subsystems in their moral processing brain centers.

Haidt argues that human morality is a cultural construction built on top of - and constrained by - a small set of evolved psychological systems. He presents evidence that political liberals rely primarily on two of these systems, involving emotional sensitivities to harm and fairness. Conservatives, however, construct their moral understandings on those two systems plus three others, which involve emotional sensitivities to in-group boundaries, authority and spiritual purity.

When offspring genetic engineering becomes possible I expect parental choices to produce bigger differences in how people morally reason. Conservative-leaning people will make their children morally reason even more strongly in the conservative style. The liberals will do likewise. So the size of the center will shrink. This will lead to deeper political divisions and perhaps civil war in some countries and wars between countries.

I also expect offspring genetic engineering to produce more other styles of moral reasoning including ones that are rare today and others that do not exist at all today. Who knows, maybe genetic engineering will move libertarianism up in the ranks of moral reasoning styles.

By Randall Parker 2007 May 28 04:19 PM  Brain Ethics Law
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Anti-Pain Gene Therapy Reduces Osteoarthritic Damage

To the surprise of researchers a gene therapy designed to reduce pain signal transmission from arthritic joints also reduced the accumulation of damage in the joints.

Early-stage research has found that a new gene therapy can nearly eliminate arthritis pain, and significantly reduce long-term damage to the affected joints, according to a study published today in the journal Arthritis and Rheumatism. While the study was done in mice, they are the first genetically engineered to develop osteoarthritis like humans, with the same genetic predisposition that makes some more likely to develop the disease, the authors said.


In the current study, researchers found that one injection of a newly designed gene therapy relieved 100 percent of osteoarthritic pain in the study model. In addition, researchers were surprised to find that the therapy also brought about a nearly 35 percent reduction in permanent structural to joints caused by round and after round of osteoarthritic inflammation.

Yet more evidence for the damage caused by chronic inflammation. Anti-inflammatory effects of foods should be considered when trying to choose an optimal diet. Also, the results illustrate how the deterioration of an aging body feeds on itself in a vicious cycle. Damage initiates processes which cause yet more damage which initiates still more damage-producing reactions.

All they did was to increase the number of opioid receptors on nerve cells. This was done so that arthritic joints wouldn't cause pain signals to get sent to the brain.

On nerve cells for instance, certain receptors are shaped to accept naturally occurring painkillers called opioids, which when they dock, prevent the sending of pain messages along nerve pathways.

In the current study, researchers used gene therapy to increase by about one thousand times the number of opioid receptors expressed on the surfaces of nerve cells that carry pain messages back and forth between an osteoarthritic jaw joint and the spinal cord. Thus, nerve cells involved in pain transmission, with so many more receptors on their surfaces, became drastically more responsive to the naturally occurring painkiller, researchers found.

The researchers hypothesize that the chronic pain signals from a bad joint trigger an inflammation response in other parts of the body causing more joints to become arthritic. They also suspect the chronic pain might contribute to the development of brain diseases such as Alzheimer's and Multiple Sclerosis.

This result strongly suggests that better methods to control pain will slow aging. It also draws attention to the importance of inflammation in disease development (and probably argues for eating more fish more omega 3 fatty acids in order to reduce inflammation). This result also demonstrates how scientific experimentation will sometimes turn up useful results that are unexpected. Direction of scientific research does not work well with too much central planning since results are so often unforeseeable. Individual scientists deserve considerable latitude in choice of experiments.

By Randall Parker 2007 May 28 12:43 PM  Biotech Gene Therapy
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2007 May 27 Sunday
China Wiping Out SE Asian Species

A boat discovered off of China draws attention to Chinese demand for endangered species.

Endangered, hunted, smuggled and now abandoned, 5,000 of the world's rarest animals have been found drifting in a deserted boat near the coast of China.

The boat had lots of rare species.

According to the local media, the cargo included 31 pangolins, 44 leatherback turtles, 2,720 monitor lizards, 1,130 Brazilian turtles as well as the bear paws. Photographs showed other animals, including an Asian giant turtle.

All of these south-east Asian species are critically endangered, banned from international trade and yet openly sold in restaurants and markets in China's southern province of Guangdong, which is famous for its exotic cuisine.

The accidental discovery highlights the negative impact that the growing power of Chinese consumption is having on global conservation efforts.

Growing Chinese demand is wiping out species in a growing list of countries.

As a result of demand, the pangolin populations of China, Vietnam, Laos and Cambodia have been wiped out. With traders moving further and further south, the animal is declining even in its last habitats in Java, Sumatra and the Malaysian peninsula. It is a similar story for many species of turtle, tortoise, frog and snake.

As the buying power of Chinese consumers continues to grow rapidly this problem will only get worse. Brian Wang thinks China might surpass the United States in GDP terms by 2020. Brian also believes the rate of urbanization in China is faster than generally believed.

The United States went through industrialization with a much smaller population than it has now and a far smaller population than China has now. Mass Chinese demand for environmental protections will not happen until Chinese per capita GDP rises to some multiple of what it is today. That means Chinese economic growth will cause far larger amounts of environmental damage than US economic growth did when the US passed through the same stages of development. Hence the wiping out of many species in southeast Asia.

Global warming gets all the press. But if you want to look at it from the standpoint of the many endangered species why care about global warming? These species will go extinct and therefore won't still be around to experience global warming.

Industrialization and population growth pose huge problems for remaining shrinking habitats. They pose far larger problems than the possibility of global warming. Western intellectuals who have worked themselves up into a tizzy about global warming are ignoring problems that should be treated as much higher priority.

By Randall Parker 2007 May 27 01:35 PM  Trends Extinction
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2007 May 23 Wednesday
New Material Lowers Fire Risk Of Lithium Batteries

A new material may help make lithium batteries more feasible for constructing hybrid electric vehicles.

Researchers at Tonen Chemical, an affiliate of ExxonMobil Chemical based in Tokyo, Japan, have developed a new separator that plays an active role in keeping batteries from overheating. The material could make it possible to slow the reactions, allowing the battery to cool off rather than bursting into flame, says Peter Roth, program manager for advanced technology development at Sandia National Laboratories, in Albuquerque, NM. Sandia is now testing the safety features of the new separator.

Better battery technology will eventually cause electricity rather than liquid hydrocarbons to power most vehicle movement. Liquid fuel will get used mostly for longer trips. Batteries will power most shorter trips.

By Randall Parker 2007 May 23 10:58 PM  Energy Batteries
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Sixth Of European Mammal Species Face Extinction

I wish species extinctions got one tenth the attention that global warming gets. Many European mammalian species are at risk of extinction.

One-sixth of Europe's mammal species are threatened with extinction, according to a comprehensive survey by the World Conservation Union (IUCN). Unless the trend is reversed, conservationists fear that the European Union will not be able to meet its self-imposed target of halting biodiversity loss by 2010.

Of the roughly 250 mammal species that live in Europe and western Russia, some 15% are classed as 'vulnerable' or worse, according to the IUCN's criteria. This means that they face a "high risk of extinction in the wild" if action is not taken.

The Europeans could reduce the pressure on species by stopping immigration. Fewer people means more room for animals.

The world as a whole has even bigger problems.

OSLO -- Human activities are wiping out three animal or plant species every hour and the world must do more to slow the worst spate of extinctions since the dinosaurs by 2010, the United Nations said Tuesday.

Scientists and environmentalists issued reports about threats to creatures and plants including right whales, Iberian lynxes, wild potatoes and peanuts on May 22, the International Day for Biological Diversity.

The UN calculates its estimates based on the loss of habitats rather than based on specific species previously known that can't be found. But lots of species haven't been cataloged and for some species no one is going out to check.

Some people think the world's population growth is no longer a problem due to a projected peaking at 9 billion. But the next 3 billion humans are going to wipe out a lot of habitats before the problem stops getting worse. Also, biotechnological advances will increase human life expectancy and human fertility. Natural selection for higher fertility (especially for a stronger desire to have kids) will also exert effects that could make the current growth projection excessively optimistic.

The embrace of biomass energy by political elites is also going to contribute to species extinction since land used to grow biomass energy crops is land that ceases to support assorted plant and animal species.

By Randall Parker 2007 May 23 10:52 PM  Trends Extinction
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Newest Brain Neurons Learn More Easily

New neurons continually formed in the brain from neural stem cells are more plastic and probably enhance learning abilities.

The steady formation of new brain cells in adults may represent more than merely a patching up of aging brains, a new study has shown. The new adult brain cells may serve to give the adult brain the same kind of learning ability that young brains have while still allowing the existing, mature circuitry to maintain stability.

These results are good news for the future of rejuvenation therapies. The development of replacement youthful neural stem cells to replace aging neural stem cells will likely boost learning ability in aging minds.

The brain is going to be the hardest organ to rejuvenation because most of it will need to be repaired rather than replaced. Replacement using stem cells will become possible before repair using gene therapy and nano repair robots.

Newly formed nerve cells behave in a more youthful manner than cells that have been neurons for longer periods of time.

Hongjun Song and colleagues reported their findings in the May 24, 2007 issue of the journal Neuron, published by Cell Press.

In their experiments, they used a virus to selectively label new brain cells with a fluorescent protein in the hippocampus, a major brain center for learning and memory, of adult mice.

The researchers then analyzed the electrophysiological properties of the new neurons at different times after their formation. This analysis enabled them to measure how adaptable, or "plastic," the brain cells were.

The researchers found that the new adult neurons showed a pattern of changing plasticity very similar to that seen in brain cells in newborn animals. That is, the new adult brain cells showed a "critical period" in which they were highly plastic before they settled into the less plastic properties of mature brain cells. In newborn animals, such a critical period enables an important, early burst of wiring of new brain circuitry with experience.

What’s more, the researchers’ molecular analysis showed that the plasticity of new adult neurons depended on the function of one of the same types of receptors that is associated with learning-related processes in newborn animals. Such receptors are the receiving stations for chemical signals called neurotransmitters, launched from neighboring neurons to trigger a nerve impulse in the receiving neurons. Subtle alterations in receptor populations are the means by which the brain wires the preferred pathways in the process of learning and memory.

Part of the loss of plasticity is probably due to age. But some of the loss of plasticity might be by program. Once a neuron has been around for a while it has probably found some purpose and there's probably a bias in the brain's design against letting a neuron too easily get reprogrammed for other purposes.

By Randall Parker 2007 May 23 10:37 PM  Brain Memory
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2007 May 22 Tuesday
Technological Assists To Accelerate Evolution?

Some scientists at Arizona State University in Tempe are experimenting around with faster ways to find better gene and protein designs.

Nature, through the trial and error of evolution, has discovered a vast diversity of life from what can only presumed to have been a primordial pool of building blocks. Inspired by this success, a new Biodesign Institute research team, led by John Chaput, is now trying to mimic the process of Darwinian evolution in the laboratory by evolving new proteins from scratch. Using new tricks of molecular biology, Chaput and co-workers have evolved several new proteins in a fraction of the 3 billion years it took nature.

Their most recent results, published in the May 23rd edition of the journal PLoS ONE, have led to some surprisingly new lessons on how to optimize proteins which have never existed in nature before, in a process they call ‘synthetic evolution.’

I expect technological methods for creating new variations will some day allow scientists and bioengineers to search large solution spaces to come up with protein design improvements that will allow us to introduce huge improvements in human body designs. We'll not just take out the harmful mutations that we carry. We'll also replace beneficial mutations with even more beneficial mutations.

Natural selection is slow at selecting better designs because species have to go through many generations of reproduction in order to select for small improvements. Faster ways to find better designs will come in the future with testing of large numbers of gene and protein changes in microfluidic devices.

The scientists generated random mutations and tested them for the desired qualities.

Chaput’s group decided to speed up protein evolution once again by randomly mutating the parental sequence with a selection specially designed to improve protein stability. The team upped the ante and added increasing amounts of a salt, guanidine hydrochloride, making it harder for the protein fragment to bind its target (only the top 10 percent of strongest ATP binders remained). After subjecting the protein fragments to several rounds of this selective environmental pressure, only the ‘survival of the fittest’ ATP binding protein fragments remained.

The remaining fragments were identified and amino acid sequences compared with one another. Surprisingly, Chaput had bested nature’s designs, as the test tube derived protein was not only stable, but could bind ATP twice as tight as anything nature had come up with before.

To understand how this information is encoded in a protein sequence, Chaput and colleagues solved the 3-D crystal structures for their evolutionary optimized protein, termed DX, and the parent sequence.

In a surprising result, just two amino acids changes in the protein sequence were found to enhance the binding, solubility and heat stability. "We were shocked, because when we compared the crystal structures of the parent sequence to the DX sequence, we didn’t see any significant changes," said Chaput. "Yet no one could have predicted that these two amino acids changes would improve the function of the DX protein compared to the parent.

My guess is that the search for useful variations could be accelerated by introducing mutations that are not random. Rules could be developed based on a growing body of knowledge about amino acid sequences and protein functionality in order to come up with genetic variations that are more likely to improve a protein for some purpose. Also, as computers become more powerful we'll reach a point where testing of variations will become possible in computer models rather than by creating real proteins.

We are going to optimize our genomes just as computer programmers optimize and improve computer code. New types of flaws will get introduced in the process. But many more existing flaws will get fixed.

You can read the full paper for free: Structural Insights into the Evolution of a Non-Biological Protein: Importance of Surface Residues in Protein Fold Optimization.

By Randall Parker 2007 May 22 11:26 PM  Evolution Acceleration
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2007 May 20 Sunday
Average Egg Donor Price Over Four Thousand Dollars

An article in the New York Times reports on the prices in the egg donor market in the United States.

A survey published this month in the journal Fertility and Sterility, “What Is Happening to the Price of Eggs?” found that the national average compensation for donors was $4,217. At least one center told the authors of the paper that it paid $15,000. Many centers did not respond.

Though laws prohibit the sale of transplant organs, sperm donors have always received small payments, and prospective parents in the United States are allowed to compensate women for their far greater expenditure of time and energy. (Many countries, including Canada and Britain, do prohibit payments to egg donors.)

I am disappointed that the average payment is so low. Why? Because if the buyers were chiefly going for the highest IQ egg donors (e.g. Ivy League, CalTech, MIT, and Stanford undergrads) then the average payment would be in the tens of thousands. Prospective parents will get smarter kids with much greater earning potential and lower risks of crime and other problems if they pay the extra money it takes to use smarter donors. The money spent up front will pay itself back many times over in the long run.

Interesting facts about regional variations come out in the abstract of this article "What is happening to the price of eggs?".

Over half SART clinics (53%, 207 out of 394) responded to the survey, with 191 (92%, 191 out of 207) having a donor oocyte program. The national average for standard donor compensation was $4,217, with a maximum payment average of $4,576. Geographic location affected compensation rates, with highest reported standard mean compensation in the East/Northeast ($5,018) and West regions ($4,890), and lowest in the Northwest ($2,900).

Why is the Northwest of the United States such a bargain would the buyers? Are more women in the Northwest willing to donate for free? Or are the Northeast and West buyers more discriminating and going for relatively smarter (and therefore more expensive) donors at higher frequencies?

Countries that prohibit payments to donors aren't taking a moral high road. The women who donate are taking health risks and might even be aging their ovaries more rapidly due to the effects of the hormones used to stimulate egg release. Plus, the lack of a market means the higher IQ women are going to be less available for donation and hence the average IQ quality and other quality of egg donors will be lower. Why contribute to lower intellectual quality of future generations by prohibiting a market in donor eggs?

Now for a repeat of predictions I've made in the past: The development of cheap DNA testing techniques will increase the desirability of using egg donors. The ability to identify women whose genes possess the best genetic alleles for one's preferences will make the use of donor eggs into a way to produce babies with more desired qualities. Testing will lower risks and at the same time improve quality of outcome.

Cheap full genome genetic testing will also cause a much greater spread in donor egg prices. Women who are now contenting themselves with $2000 or $3000 eggs will, in the future, know how much they are giving up by going with cheaper eggs. I expect a drop in demand for lower quality eggs and an even larger boost in demand for highest quality eggs.

Some of you may wish to quibble with my use of terms like "lower quality" and "highest quality" in reference to donor eggs. Granted, there is no single accepted standard on what constitutes genetic quality. But that does not matter. Each buyer will bring their own personal values and preferences to their decision-making processes and they will choose among genetic features based on their own judgments on what constitutes high quality. In other words, the market will define quality and will do so in each potential transaction.

Since people have no shortage of preferences in what they like and dislike in other people and in what they'd like their offspring to become (or not become - e.g. afflicted with diseases and disorders, criminal, crazy) I expect that given the ability to choose among donors based on detailed genetic information people will find many reasons to discriminate between the genetic profiles of lists of potential egg donors.

Cheap genetic testing is not the only forthcoming technological advance that will cause an increase the use of high priced donor eggs. In the comments of a previous post David Friedman noted that science fiction novelist Robert Heinlein described in his novel Beyond This Horizon a way to avoid the uncertainty of not knowing which of each chromosome pair will get passed down to offspring. Start with a cell that has the full genome of a donor. Under controlled conditions induce it to turn into two eggs. Then genetically test one of the eggs. From the test results and from a genetic sequencing of the entire genome one can deduce which of each chromosome pair is in the undestroyed egg of the two egg pair.

With automation of microfluidic devices this process could get repeated hundreds or thousands of times until an egg with the desired chromosomes was found. That egg could then be fertilized. The same process could be performed to create the sperm used to do the fertilization. This will enable prospective parents to get the better genetic variations from donors and hence increase the odds that use of donors will produce much higher quality results in offspring. That will increase the attractiveness of using donor cells.

By Randall Parker 2007 May 20 01:47 PM  Bioethics Reproduction
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Best Weight Loss Diet Depends On Insulin Secretion

Different studies produce conflicting results on the question of which diet is best for weight loss. A recent study that looked insulin response to sugar consumption found that for people whose bodies produce more insulin in response to an oral glucose tolerance test the best diet is one that lowers glycemic index.

Overweight individuals who secrete insulin at a higher level may experience greater weight loss by selecting a low-glycemic load diet, compared to a low-fat diet, according to a study in the May 16 issue of JAMA. The researchers also found a low-glycemic load diet to have beneficial effects on HDL cholesterol and triglyceride concentrations.

"With prevalence approaching one-third of the population, obesity is among the most important medical problems in the United States and identification of effective dietary treatment has become a major public health priority. Three popular diets—low fat, low carbohydrate, and low glycemic load—have recently received much attention. However, clinical trials have produced inconsistent findings, with some suggesting that one diet is superior for weight loss and others indicating no difference between diets," the authors write. They add that one explanation for the inconsistent findings could relate to the inherent physiological differences among study participants. "One physiological mechanism that might relate weight loss to dietary composition is individual differences in insulin secretion."

A low glycemic index diet is one which contains carbohydrates in forms that break down slowly in the intestine.

A low glycemic index diet works best for people whose bodies secrete more insulin in response to consuming glucose.

The researchers found that change in body weight and body fat percentage did not differ between the diet groups overall. However, for those with insulin concentration at 30 minutes above the median (midpoint), the low–glycemic load diet produced a greater decrease in weight (12.8 lbs. vs. 2.6 lbs.) and body fat percentage (–2.6 percent vs. –0.9 percent) than the low-fat diet at 18 months. There were no significant differences in these end points between diet groups for those with insulin concentration at 30 minutes below the median level. Among all the participants in the study, high-density lipoprotein cholesterol (the "good" cholesterol) and triglyceride concentrations improved more on the low–glycemic load diet, whereas low-density lipoprotein cholesterol (the "bad" cholesterol) concentration improved more on the low-fat diet.

"The main finding of our study is that a simple measure of insulin secretion predicted weight and body fat loss on low–glycemic load and low-fat diets," the authors write. "For obese individuals with high insulin concentration at 30 minutes during an oral glucose tolerance test, a low–glycemic load diet may promote more weight and body fat loss than a low-fat diet. Regardless of insulin secretion, a low–glycemic load diet has beneficial effects on concentrations of HDL cholesterol and triglycerides but not on LDL cholesterol. Additional research is needed to examine these effects in other populations and to explore the mechanistic basis for the observed diet-phenotype interaction."

The big insulin response could cause more weight gain by a couple of mechanisms. First off, the greater amount of insulin causes the sugar to get cleared from the blood more rapidly. Therefore blood sugar drops and the more rapid return to a state of lower blood pressure probably brings with it hunger pangs. Second, some of the sugar that gets moved out of the blood gets converted into fat for storage. If the sugar came into the blood and exited the blood more slowly the body could probably burn more of it before it gets converted to fat.

A diet that does not much stimulate the islets of Langerhans. on your pancreas to pump out a lot of insulin in response to what you eat is probably a better diet regardless of whether you are trying to lose weight. Big blood sugar spikes cause sugar to bind in places harmful to your health and that accelerates aging. That is why diabetics have much shorter life expectancies.

If you want to lower the glycemic index of your diet then choose among foods that have low glycemic index. Here is the glycemic index for hundreds of foods. Also see David Mendosa's satiety index for foods.

Here is the research paper: Effects of a Low–Glycemic Load vs Low-Fat Diet in Obese Young Adults.

By Randall Parker 2007 May 20 11:52 AM  Aging Diet Studies
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2007 May 19 Saturday
Dysgenic California Legislation Against Non-Pure Bred Dogs

Friends of Fido, Rover, and Lassie unite against a bad idea for dogs.

Assembly Bill 1634, which requires dogs over four months of age to be spayed or neutered, passed the Assembly Business and Professions Committee on April 24 by a vote of 7 to 3. The bill, sponsored by Lloyd Levine, D-Van Nuys, requires dog owners to have their dogs spayed or neutered at their own expense. Registered, purebred dogs are exempt from the requirement. The bill has been re-referred to the Committee on Appropriations.

The goal of this California state legislation is likely to reduce the number of dogs euthanized in dog pounds and shelters. So Levine wants to reduce the killing of dogs. A laudable goal. But he hasn't thought through the consequences.

First off, he doesn't just restrict breeding to purebreds. He restricts breeding to registered purebreds. Now, the registered purebred societies have generated monster dogs in search of stupid ideal breed designs. Look at the flattening of the bull dog face. That's sadistic. So is the current bull dog body shape. From an engineering standpoint it is stupid. Or look at the short hind quarters of German Shepherds. Or how about the unnaturally much more narrow snout of today's rough collies? Lassie's descendants are probably dumber as a consquence of the skull shrink caused by the pursuit of a narrower snout. How about thinking of the quality of life of dogs before creating freak show animals and calling them normal?

When I first read that Australian Shepherds (note to Australian readers: they are an American breed that probably started out with Aussie herding dogs that were brought to California during the gold rush) were going to become an AKC registered breed I was angry. Oh no, those upper middle class ladies who like to parade highly primped dogs around at dog shows are going to ruin yet another excellent breed developed for herding (including herding of yours truly). I think the esthetic breeder types have a lot to answer for. Their in-breeding and pursuit of breed standards that can only be described as Frankensteinish should not be encouraged with state legislation.

My late great Australian Shepherd Oakley never got registered (and when I say great I'm describing the consensus of a lot of people who were more objective about him than I was). Under Lloyd Levine's law Oakley, as a non-registered dog, would be barred from breeding in the state of California. Instead, show dogs would breed and anyone who wanted to buy a dog would be required to choose among dogs that upper class dog show ladies find suitable. I do not want to live in that sort of world.

Among the consequences of Levine's proposal: New breeds could not be created. Any mixed breed dog that was the first attempt at creating a new breed would get neutered. Also, any breeds that exist today without recognition by the AKC or similar breed association would become an evolutionary dead end that would go extinct after the current living generation.

Levine's proposal fits a larger pattern where the big organizations called governments force more behavior to take place within the context of controls and rules of other big organizations. Want to breed a dog? Gotta get that dog registered and you can only register dogs that fit the arbitrary breed guidelines of existing associations. So the proposal pushes us toward a more bureaucratic society and a more dysgenic one to boot. Tell your elected officials to find another way to reduce dog over-population.

By Randall Parker 2007 May 19 01:11 PM  Evolution Animals Helpers
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2007 May 16 Wednesday
Boiling Vegetables Reduces Anti-Cancer Benefits

Steaming, microwaving, and stir-frying are all much better than boiling.

The researchers, Prof Paul Thornalley from Warwick Medical School at the University of Warwick and Dr Lijiang Song from the University of Warwick’s Department of Chemistry bought Brassica vegetables, (broccoli, Brussel sprouts, cauliflower and green cabbage) from a local store and transported them to the laboratory within 30 minutes of purchasing. The effect of cooking on the glucosinolate content of vegetables was then studied by investigating the effects of cooking by boiling, steaming, microwave cooking and stir-fry.

Boiling appeared to have a serious impact on the retention of those important glucosinolate within the vegetables. The loss of total glucosinolate content after boiling for 30 minutes was: broccoli 77%, Brussel sprouts 58%, cauliflower 75% and green cabbage 65%.

The effects of other cooking methods were investigated: steaming for 0–20 min, microwave cooking for 0–3 min and stir-fry cooking for 0–5 min. All three methods gave no significant loss of total glucosinolate analyte contents over these cooking periods.

I'm big on eating raw cabbage as cole slaw. Stir-frying seems like the most attractive way to prepare the other Brassica (aka cruciferous) vegetables.

By Randall Parker 2007 May 16 10:52 PM  Aging Diet Cancer Studies
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Ethanol Demand Decreases Corn For Animal Feed

Regular readers know that I think biomass energy is a bad idea that shows just how ignorant or morally corrupt our elites can be. Please excuse me if I'm boring you with repetition. But repetition doesn't just breed acceptance of lies. Repetition also breeds the acceptance of the truth. US government subsidies of biomass energy are decreasing the amount of corn available to feed livestock.

The surging biofuel industry will use 27% of this year's American corn crop, challenging farmers' ability to meet food demands, the US government says.

How to think about this? We are feeding over a quarter of our corn to our cars. Our cars are becoming corn hogs. Imagine we all rode horses and fed them corn. What we are doing is like that. But we ride mechanical horses (hence the term "horsepower") and with car computers that provide driving assists (e.g. anti-lock braking, traction control, and electronic stabilization control) those mechanical horses are well on their way toward becoming robotic horses. Cars are robotic horses that consume a lot more energy and hence more land.

Even with the projected, record 12.46 billion-bushel crop this year, the US Department of Agriculture (USDA) says national corn stockpiles will run low going into the next crop year, when voracious ethanol demand will rise again.

In its first projections of this year's crops, the USDA says ethanol is already boosting crop prices, and will reduce the amount the amount of corn used to feed livestock in the coming year by 3%.

Note that the US population is growing, not shrinking. So the demand for meat will rise even as the amount of corn available to feed livestock shrinks.

The Grocery Manufacturers Association (GMA) sees many harms from the rapid increase in use of corn as an energy source.

"Consumers have already seen an increase in the cost of food, as corn traditionally used for livestock feed and processed food is increasingly used for fuel.

In fact, the price of corn has nearly doubled in the last nine months.

"In addition to its inflationary impact, there are many unintended, but nonetheless important, consequences of an ambitious corn ethanol strategy.

"For example, a 35 billion gallon ethanol mandate will require a substantial increase in the use of fossil fuels for corn and ethanol processing and transportation, as well as an additional fifteen million acres devoted to corn crops, which will encroach on agriculturally-marginal and environmentally- sensitive land.

Some people are under the mistaken impression that the United States has such huge amounts of unused space that a massive ramping up of agriculture to produce biomass energy won't impose substantial environmental costs. But the amount of land available for farming shrinks as the population grows and suburbs around cities expand outward.

How about world hunger?

"An aggressive ethanol mandate will also require the U.S. to significantly reduce its corn exports to ensure an adequate supply of corn for food and fuel.

"Such a reduction will result in a decrease in the amount of food available overseas, which in turn will have a negative affect on world hunger.

But biomass ethanol is green. Hunger? Encroachment on wildlife areas? Okay, but corn plants have a green color. End of argument. Shut down your neocortex. Suppress any thoughts that begin with "But". Corn stalks are plants that sop up the goodness of solar energy They aren't humans. How can the grocery companies oppose something that politicians running in primaries in Iowa find to be the best thing since Mazola corn oil spread on sliced bread?

The GMA wants an end to the US government subsidy for ethanol. I agree (my neocortex refuses to shut down).

"In addition, GMA supports a broad-based approach to alternative fuels that includes the increased use of cellulosic ethanol, the elimination of the fifty-four cents per gallon tariff on ethanol imports and the expiration of the taxpayer-funded fifty-one cents per gallon ethanol subsidy.

But elimination of the ethanol tariff will just speed the deforestation of the Amazon. I wonder what greenies are thinking when I see some of them interviewed on TV extolling Brazil's production of ethanol as an example of morally virtuous behavior. What about the rain forests?

In a 12 month period ending August 2004 Brazil's rainforests shrunk by an area the size of Massachusetts.

Government officials acknowledge that loggers, ranchers and farmers gobbled up 10,088 square miles of Amazon rain forest in the 12-month period ending last August, an area about the size of Massachusetts.

Strains of soy developed for Brazil are enhancing the attractiveness of soy as a crop for Brazilian farmers. So is the increased use of soy to make biodiesel. What's the result? Destruction of Amazon rainforests.

But, to the horror of environmental activists, soybeans are claiming increasingly bigger swaths of rainforest to make way for plantations, adding to the inroads by ranching. The Amazon lost some 10,000 square miles of forest cover last year alone -- 40 percent more than the year before.

In Querencia, cowboy-hatted ranchers recently transplanted from Brazil's prosperous south rub shoulders with Amazon Indians as streams of tractor-trailers kick up dust hauling fertilizer in and huge tree trunks out. Nowhere is the doubled-edge thrust of soybeans more apparent than in this dusty boom town on the rainforest's southern edge.

"The farmers are cutting down everything to make way for soy and that's good business for me," said Ivo de Lima, a lumber man who moved here recently.

The shift of US acreage way from soy toward corn for ethanol increases demand for soy from Brazil which increases the destruction of the Amazon rain forests. So the US corn ethanol subsidy increases the rate of destruction of the world's rainforests.

By Randall Parker 2007 May 16 10:39 PM  Energy Biomass
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2007 May 15 Tuesday
Large DNA Structural Variations Target Of Study

Single DNA letter differences have garnered most of the popular and scientific attention for the study of human genetic differences. But larger genetic differences such as large copy variations (where people differ in how many copies they have of genes and sections of genes) have come under greater scrutiny as researchers have developed techniques to measure these differences. Studies of large DNA structural variations have begun to bear fruit.

A major new effort to uncover the medium- and large-scale genetic differences between humans may soon reveal DNA sequences that contribute to a wide range of diseases, according to a paper by Howard Hughes Medical Institute investigator Evan Eichler and 17 colleagues published in the May 10, 2007, Nature. The undertaking will help researchers identify structural variations in DNA sequences, which Eichler says amount to as much as five to ten percent of the human genome.

Past studies of human genetic differences usually have focused on the individual “letters” or bases of a DNA sequence. But the genetic differences between humans amount to more than simple spelling errors. “Structural changes — insertions, duplications, deletions, and inversions of DNA — are extremely common in the human population,” says Eichler. “In fact, more bases are involved in structural changes in the genome than are involved in single-base-pair changes.”

Efforts to estimate the amount of genetic difference between people and groups have produced underestimates of the real differences. The newer studies of genetic differences which measure large copy variations (e.g. differences in the number of copies of genes or sections of genes) are finding much larger differences between humans. I suspect these differences show how much local selective pressure humans experiences in each local environmental niche they moved into. We are not as alike as the politically correct would have us believe.

Eichler and colleagues are searching for large copy variations in DNA taken from 62 people.

Using DNA from 62 people who were studied as part of the International HapMap Project, they are creating bacterial “libraries” of DNA segments for each person. The ends of the segments are then sequenced to uncover evidence of structural variation. Whenever such evidence is found, the entire DNA segment is sequenced to catalog all of the genetic differences between the segment and the reference sequence.

The result, says Eichler, will be a tool that geneticists can use to associate structural variation with particular diseases. “It might be that if I have an extra copy of gene A, my threshold for disease X may be higher or lower.” Geneticists will then be able to test, or genotype, large numbers of individuals who have a particular disease to look for structural variants that they have in common. If a given variant is contributing to a disease, it will occur at a higher frequency in people with the disease.

Their use of DNA from people studied in the International HapMap Project creates synergies between the databases generatd by each effort. The International HapMap Project involves measuring single letter differences. Some of the single letter differences correlated with variations in structures such as deletion mutations and in number of copies of each gene.

We live in the twilight of the era of when little has been known about how genetic variations create human variations in health, appearances, intelligence, personality and other human qualities. 20 years from now we are going to know in enormous detail which genetic variations matter and how they matter. Continued declines in the cost of DNA testing will provide scientists with orders of magnitude more genetic data than they have now.

Once we know what most of the genetic variations mean I expect many changes in how we live our lives. For example, I expect those involved in romantic courtships to either surreptitiously get DNA samples from potential mates or demand DNA testing info as a prelude to serious courting.

By Randall Parker 2007 May 15 09:38 PM  Biotech Advance Rates
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2007 May 13 Sunday
Silicon Valley Investing In Clean Energy Companies

"Get 'er done" kinds of people are investing in cleaner energy technologies.

Most of Silicon Valley's current emphasis is on clean energy. Entrepreneurs here are aiming to transform solar, fuel-cell, and biofuel projects into viable industries with huge potential. Already, the market amounts to $55 billion – more than the entire Internet advertising market dominated by the high-tech region's current darling, Google. In 10 years, the clean-energy market by one estimate could quadruple. In the past year, for the first time, more silicon in the US has gone toward making solar panels than computer chips. More important, venture capitalists are pouring money into clean technology, thanks to a confluence of events.

We aren't going to go into a long economic depression due to Peak Oil. Nor are we just going to keep using fossil fuels as our biggest sources of energy. Solar photovoltaics, wind, nuclear, and other non-fossil fuels energy sources are going to displace fossil fuels.

The venture capitalists are placing many energy bets.

Silicon Valley is buzzing with optimism. Venture capital funding jumped sixfold to $300 million from the first to the third quarter last year.

Over a 25 year period the cost of photovoltaics fell by almost an order of magnitude.

The price for a watt of solar power, adjusted for inflation, went from $21.83 in 1980 to $2.70 in 2005, according to Applied Materials.

Within five years, a SunPower spokesperson predicts, the price of solar power will rival – without any subsidies – the price of conventional power.

Can the cost of photovoltaics fall much more rapidly in the future? What we've witnessed for decades were improvements in making photovolatics from silicon crystals. A shift to other types of materials using completely different fabrication methods (e.g. TiO2 nanotubes) will eventually lower costs by orders of magnitude. I can't say this will happen in the next 5 or 10 years. Maybe. But it will happen some day. Photovoltaics will not always come at too high prices.

By Randall Parker 2007 May 13 06:59 PM  Energy Policy
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Solar Concentrators To Lower Home Solar Energy Costs

Kevin Bullis of MIT's Technology Review reports on a new solar photovoltaic technology developed by Pasadena California start-up Soliant Energy which lowers the cost of photovoltaic power by use of a compact roof-mountable solar concentrator design.

Soliant has designed a solar concentrator that tracks the sun throughout the day but is lighter and not pole-mounted. The system fits in a rectangular frame and is mounted to the roof with the same hardware that's used for conventional flat solar panels. Yet the devices will likely cost half as much as a conventional solar panel, says Hines. A second-generation design, which concentrates light more and uses better photovoltaics, could cost a quarter as much. He says that a more advanced design should be ready by 2010.

The Soliant design combines both lenses and mirrors to create a more compact system. Each module is made of rows of aluminum troughs, each about the width and depth of a gutter. These troughs are mounted inside a rectangular frame and can tilt in unison from side to side to follow the sun.

Existing solar concentrators are too large and complicated to mount on residential roofs.

Due to my expectation that we'll see truly disruptive technologies come to market, I've long been skeptical of 50 and 100 year projections of carbon dioxide emissions from fossil fuels consumption. There's no way we are going to get out 30 years from where we are now without the development of a variety of technologies that make solar photovoltaics, wind, batteries, nuclear, and other non-polluting power sources much cheaper.

This report above provides an example of how we can expect disruptive technologies to come out of entrepreneurial start-ups. The higher the price of oil gets the more energy technology innovation we are going to witness.

We could speed up the rate of innovation by taxing fossil fuels or by government funding of more energy research. I prefer the latter approach over the former because I think it would require less cash shifted through government hands. Better a $10 billion a year research budget than several hundreds of billions per year of green taxes.

By Randall Parker 2007 May 13 01:50 PM  Energy Solar
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2007 May 10 Thursday
Alzheimers Disease Caused By Nerve Demyelination?

A UCLA prof thinks decay of a nerve insulating material called myelin might be a key step that leads to Alzheimer's Disease.

Wisdom comes with age (doesn't it?), but not without a process that takes place in the brain called myelination. Myelin is the fatty sheath that coats the axons of the nerves, allowing for efficient conduction of nerve impulses. It is key to the fast processing speeds that underlie our higher cognitive functioning, including, yes, wisdom.

Myelination continues sheathing axons until we reach the age of about 50, but in these later stages, the myelin becomes more and more susceptible to damage. Now, in a report in the April issue of the journal Alzheimer's & Dementia, Dr. George Bartzokis, UCLA professor of neurology, suggests that it is the breakdown of this late-stage myelin that promotes the buildup of toxic amyloid-beta fibrils that eventually deposit in the brain and become the plaques which have long been associated with Alzheimer's disease.

These amyloid products in turn destroy more and more myelin, according to Bartzokis, disrupting brain signaling and leading to cell death and the classic clinical signs of Alzheimer's. If correct, the research suggests a broader approach to therapeutic interventions for the disease.

If myelin breakdown is behind Alzheimer's then that strongly suggests to me that brain rejuvenation therapies that repair and replace myelin would be most effective at preventing and stopping Alzheimer's.

Late stage added myelin is thinner and breaks down more easily.

"Myelination of the brain follows an inverted U-shaped trajectory, growing strongly until middle age. Then it begins to breakdown," Bartzokis said. "Before the advent of modern medicine, very few persons lived beyond age 50 and therefore, as a species, we evolved to continue myelinating over our entire natural life span."

As a result, the volume of myelinated white matter increases to a peak at about age 50, then slowly begins to reverse and decline in volume as we continue to age. The myelin that is deposited in adulthood ensheaths increasing numbers of axons with smaller axon diameters, and so spreads itself thinner and thinner, he said. As a result, it becomes more susceptible to the ravages of age in the form of environmental and genetic insults and slowly begins to break down.

Your myelin slowly breaks down after age 50. That, by itself, is thoroughly disgusting even before we consider the threat from Alzheimer's. The brain is our most powerful tool. Our brains become less powerful. In the process of its decay and aging we become less capable and lose parts of who we are. Shouldn't we try much harder with research funding to find ways to stop and reverse brain aging?

Dr. Bartzokis found that the areas of the brain with the latest myelin formation are the areas where amyloid plaques form.

Oligodendrocytes and myelin have the highest levels of iron of any brain cells, Bartzokis said, and circumstantial evidence supports the possibility that brain iron levels might be a risk factor for age-related neurodegenerative diseases like Alzheimer's. In the study, he suggests that myelin breakdown in the late-myelinating regions releases iron, which promotes the development of the toxic amyloid oligomers and plaques, which in turn destroy more myelin.

Bartzokis tested his hypothesis by examining published images of amyloid deposition acquired in living individuals; the images were made using radiolabeled ligands molecules that bind to amyloid plaques in the brains of Alzheimer's patients. Next, he compared the physical location of these plaques to much earlier work published in a the Lancet in 1901 that mapped the locations in the brain where late-stage myelination occurs. The two matched up perfectly.

Stem cells and gene therapy are both strong contenders to some day serve treatments to re-myelinate aging brains. We need faster rates of research into both approaches.

Treatments that stop and reverse nerve demyelination will some day boost worker productivity and increase the rate of economic growth. We should try 10 times harder to develop those treatments.

By Randall Parker 2007 May 10 10:58 PM  Brain Alzheimers Disease
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2007 May 09 Wednesday
Embryo Eugenics Finds New Uses

When using in vitro fertilization (IVF) to start a pregnancy in a lab dish it is possible to genetically test each embryo to avoid undesirable genetic variations or to choose desired genetic variations. William Saletan reports the list of reasons people use pre-implantation genetic diagnosis (PGD) for embryo selection is growing.

In its early days, PGD targeted fatal childhood diseases such as Tay-Sachs. But a new survey of U.S. fertility clinics, scheduled for release this week by the Genetics and Public Policy Center, suggests the line is moving. Among clinics that offer PGD, 28 percent have used it to target genes whose associated diseases don't strike until adulthood. The list includes Alzheimer's, which afflicts some people in their 30s but usually arrives much later. According to next month's Journal of Clinical Oncology, PGD has also been used to wipe out colon cancers that don't develop until age 45 to 55 and are treatable, if detected early, with survival rates of 90 percent.

For some of these adult-onset genes, the risk of illness is less than 50 percent. But it feels mean, even arbitrary, to quibble about probabilities. American clinics target these genes anyway, to prevent "cancer predisposition syndromes," if not cancer itself. Even if your child never gets sick, just knowing he has the gene can cause anxiety, as British regulators noted four months ago when they approved PGD for colon cancer.

The use of PGD has now spread beyond just avoidance of severe diseases. Some prospective parents choose to avoid genetic variations that give fairly low probabilities of diseases such as colon cancer. I see this as a waste of time for some diseases. A baby born today will not face serious risk of colon cancer until the 2050s. Well, by the 2050s I expect cancer will be easily curable or avoidable.

The other reason to refrain from selecting against genetic variations that create low risk of some diseases is that these variations might provide benefits as well. Functionally significant genetic variations found in substantial portions of the human population probably got selected for. Many genetic variations that cause specific disease risks also probably deliver some as yet undiscovered benefit.

Scientists are going to discover the costs and benefits of hundreds of thousand and possibly millions of genetic variations. As the significance of hundreds of thousands of genetic variations becomes known the advantages of using IVF with PGD will grow enormously. I expect at some point in industrialized countries natural conception will become less used than IVF. This transition point probably will happen in the next 30 years because we'll know what most of the genetic variations mean within 30 years.

Once we know a lot about hundreds of thousands of genetic variations then genetic testing of a dozen or so embryos is going to be viewed as too confining and constricting. IVF and PGD only let you choose among those combinations of parental DNA that actually happen in the half dozen or dozen embryos which will result from basically random arrangement of DNA from two parents. People will start pining for the ability to select which of each pair of chromosomes to give to junior.

The development of biotechnologies that enable selection between chromosomes will enable even greater control over which genetic variations parents will give to their offspring. Beyond that capability the next step will be gene therapy to create offspring that have genetic variations in combinations that could not occur as a result of normal sexual reproduction. Once that becomes possible the rate of human genetic change will skyrocket.

In the United States I am not expecting many restrictions on the use of IVF and PGD to select for desired genetic features beyond disease avoidance. As each new capability hits the market potential parents will demand the freedom to choose genetic features for many reasons. Looks and intelligence will be two big motivators for use of PGD and, further into the future, use of chromosome selection and gene therapy.

The ability to select genetic variations for offspring will make reproduction more appealing. This capability will allow lowering of many risks (e.g. of retardation, autism, attention deficit, and tendencies toward anger and criminality) The ability to reduce risks will greatly increase the likelihood that offspring will meet parental hopes. So kids will be born who are better looking, smarter, and better behaved. I expect an increase in fertility due to the increased likelihood that prospective parents will get children who will have desired features.

Thanks to Ivan Kirigin for the heads-up.

By Randall Parker 2007 May 09 10:46 PM  Bioethics Reproduction
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Pesticides Make Dumber Summer-Conceived Babies?

Do babies conceived during summer perform worse at cognitive tasks?

INDIANAPOLIS — Does the time of year in which a child is conceived influence future academic achievement? Yes, according to research by neonatologist Paul Winchester, M.D., Indiana University School of Medicine professor of clinical pediatrics. Dr. Winchester, who studied 1,667,391 Indiana students, presents his finding on May 7 at the Pediatric Academic Societies' annual meeting.

Dr. Winchester and colleagues linked the scores of the students in grades 3 through 10 who took the Indiana Statewide Testing for Educational Progress (ISTEP) examination with the month in which each student had been conceived. The researchers found that ISTEP scores for math and language were distinctly seasonal with the lowest scores received by children who had been conceived in June through August.

Why might children conceived in June through August have the lowest ISTEP scores? "The fetal brain begins developing soon after conception. The pesticides we use to control pests in fields and our homes and the nitrates we use to fertilize crops and even our lawns are at their highest level in the summer," said Dr. Winchester, who also directs Newborn Intensive Care Services at St. Francis Hospital in Indianapolis.

"Exposure to pesticides and nitrates can alter the hormonal milieu of the pregnant mother and the developing fetal brain," said Dr. Winchester. "While our findings do not represent absolute proof that pesticides and nitrates contribute to lower ISTEP scores, they strongly support such a hypothesis."

I can think of many other potential explanations. For example, maybe the babies conceived in the summer do not get enough vitamin D in the winter and this lack of vitamin D causes their brains to develop poorly when their brains are developing most rapidly. Maybe nutritional status matters more during later months of pregnancy.

Pesticides might also be upping the rate of premature births.

INDIANAPOLIS — The growing premature birth rate in the United States appears to be strongly associated with increased use of pesticides and nitrates, according to work conducted by Paul Winchester, M.D., professor of clinical pediatrics at the Indiana University School of Medicine. He reports his findings May 7 at the Pediatric Academic Societies' annual meeting, a combined gathering of the American Pediatric Society, the Society for Pediatric Research, the Ambulatory Pediatric Association and the American Academy of Pediatrics.

Dr. Winchester and colleagues found that preterm birth rates peaked when pesticides and nitrates measurements in surface water were highest (April-July) and were lowest when nitrates and pesticides were lowest (Aug.-Sept.).

A repeat of this experiment in other regions could control for the pesticide effect since not all areas of the United States have much agriculture. Also, growing season start dates and lengths differ by region. The effect of pesticides would start later and end earlier in Maine than in Missouri for example. We could also see a difference depending on the source of water supply. Water supplies probably vary considerably in their pesticide concentrations.

By Randall Parker 2007 May 09 12:26 AM  Brain Development
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2007 May 07 Monday
Chip Speeds Molecule Receptor Binding Affinity Search

Here's another example of the trend toward massive parallelism and micro-miniature devices for manipulating biological systems. A chip can monitor the binding affinity of 12,000 molecules at a time.

May 1, 2007 -- A chemist at Washington University in St. Louis is making molecules the new-fashioned way — selectively harnessing thousands of minuscule electrodes on a tiny computer chip that do chemical reactions and yield molecules that bind to receptor sites. Kevin Moeller, Ph.D., Washington University professor of chemistry in Arts & Sciences, is doing this so that the electrodes on the chip can be used to monitor the biological behavior of up to 12,000 molecules at the same time.

Moeller thinks he can automate the production of a variety of molecules and the testing of their affinity to receptors.

But, with an electrochemically addressable computer chip, provided in great abundance by one of his sponsor's, CombiMatrix in Seattle, Moeller saw a way of probing the binding of a library with a receptor without the need for washing by putting each member of the molecular library by an electrode that can then be used to monitor its behavior.

The electrochemically addressable chips being used represent a new environment for synthetic organic chemistry, changing the way chemists and biomedical researchers make molecules, build molecular libraries and understand the mechanisms by which molecules bind to receptor sites.

"We believe we can move most of modern synthetic organic chemistry to this electrochemically addressable chip. In this way, a wide variety of molecules can be generated and then probed for their biological behavior in real-time," said Moeller. "It's a tool, still being developed, to map receptors. We're right at the cusp of things."

Cells are covered with and contain a large variety of receptors. The ability to automate the production and screening of compounds that might bind at each kind of receptor can accelerate the search for new drugs and other biomedically useful compounds.

Biochips controllable by computers open up the prospect of highly automated science. Rather than mess around with test tubes, beakers, and the like scientists will run software that'll create and automatically test millions of chemicals looking for desired interactions.

By Randall Parker 2007 May 07 11:22 PM  Biotech Advance Rates
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Magnetic Pulse Induces Slow Wave Sleep State

A University of Wisconsin scientist has found a way to induce the slow wave sleep state of the brain.

Now, Giulio Tononi, a professor of psychiatry at the University of Wisconsin-Madison School of Medicine and Public Health, has discovered how to stimulate brain waves that characterize the deepest stage of sleep. The discovery could open a new window into the role of sleep in keeping humans healthy, happy and able to learn.

Tononi figured out how to use transcranial magnetic stimulation above a particular spot to induce the slow wave state of sleeping.

During slow wave activity, which occupies about 80 percent of sleeping hours, waves of electrical activity wash across the brain, roughly once a second, 1,000 times a night. In a paper being published this week in the Early Edition of the scientific journal PNAS, Tononi and colleagues, including Marcello Massimini, also of the UW-Madison School of Medicine and Public Health, described the use of transcranial magnetic stimulation (TMS) to initiate slow waves in sleeping volunteers. The researchers recorded brain electrical activity with an electroencephalograph (EEG).

A TMS instrument sends a harmless magnetic signal through the scalp and skull and into the brain, where it activates electrical impulses. In response to each burst of magnetism, the subjects' brains immediately produced slow waves typical of deep sleep, Tononi says. "With a single pulse, we were able to induce a wave that looks identical to the waves the brain makes normally during sleep."

The researchers have learned to locate the TMS device above a specific part of the brain, where it causes slow waves that travel throughout the brain. "We don't know why, but this is a very good place to evoke big waves that clearly travel through every part of the brain," Tononi says.

Tononi is going to use this capability to investigate his hypothesis that the slow wave state allows the brain to weaken connections that formed from events experienced during the day. He sees sleep as something that weakens many unimportant memories so that our brains do not become burdened with too many memories.

By Randall Parker 2007 May 07 11:10 PM  Brain Sleep
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2007 May 06 Sunday
Should Older Obese People Diet?

A research team at Wake Forest University Baptist Medical Center found obese old women who diet and lose weight maintain or increase their mobility.

Her study evaluated 23 obese, postmenopausal, sedentary women with a mean age of 58 who participated in the DEMO study. For five months, their meals and snacks were provided by the study and contained 400 fewer calories than they needed to maintain their weight.

Participants’ body composition and physical function were measured before and after the five-month period. Tests of physical function measured knee strength, hand-grip strength, walking speed, aerobic fitness and ability to quickly rise from a chair without using their arms. The women lost an average of 25 pounds, with muscle representing about 35 percent of the total loss.

“Despite the large amount of muscle loss, their aerobic fitness and their ability to rise from a chair showed a trend toward improvement,” said Demons. “Their strength and walking speed did not change. This suggests that their weight loss through dieting wouldn’t be expected to lead to increased disability.”

So far, so good. But the overwhelming majority of people who lose weight regain it. Well, they regained proportionately less muscle than they lost.

Lyles’ project evaluated 30 women from the DEMO study to determine body composition when weight was regained. Body composition was measured before and after the five-month period of calorie restriction. A third measurement was taken 12 months later.

The women lost an average of 25 pounds – about 32 percent of the lost weight was muscle and 68 percent was fat. The women regained an average of 11 pounds. About 27 percent of the regained weight was muscle and 73 percent was fat.

35% of their loss was muscle. But only 27% of their gain was muscle. That's not good. Some of that could be due to aging. But it seems too large a change to attribute only to aging.

I'm skeptical of the benefit of dieting for these women. Almost all of them are going to regain most or all the lost weight. Dieting might be worse than not dieting. Exercise to build up muscle mass might provide a clearer benefit. I'm skeptical that people can defeat the appetite regulation mechanism in the brain which starts telling them to eat more when they get their weight down. We need drugs that reduce appetite or for most people weight loss diets are going to do more harm than good.

By Randall Parker 2007 May 06 11:01 PM  Aging Diet Studies
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Woman Gives Birth To Her Grandsons

You know how much parents want their kids to make them into grandparents? A woman on the Greek island of Crete used biotechnology to turn herself into a grandmother. A Greek woman unable to carry a pregnancy turned to her mother to do the job with embryos created with in vitro fertilization (IVF).

A 52-year-old woman gave birth to her daughters’ twins on Crete thanks to the technique of in vitro fertilization (IVF), doctors at a private clinic in Hania said yesterday.

Other parts of the article quote the age as 54. The baby boys were born 2.5 lbs each. The premature delivery was not surprising given the grandmother's age. The aging of ovaries is not the only reason older women lose the ability to start viable pregnancies. The reproductive tract and the entire body decline with age as well.

Fast forward 20 or 30 years and picture a future when new ovaries and other female reproductive organs can be grown from scratch and implanted as replacements. More women will make babies in their 40s and 50s. Add in full body rejuvenation (sure to follow) and women will reproduce in their 60s and beyond.

Full body rejuvenation using Strategies for Engineered Negligible Senescence (SENS) will inevitably cause a big uptick in fertility. The instinctive desire to reproduce and baby fever will combine with rejuvenation therapies to drive human populations up into the tens of billions unless governments restrict reproduction.

Some people argue we should die to make room for the babies that people instinctively want to create. Some people argue (really, I'm not making this up) that we humans do not have any instinctive desire to reproduce and that we can all get taught to prefer dogs and cats to human babies. That naive Blank Slate thinking belongs in the 20th century along with lots of other foolish 20th century ideas. If we are going to reason about the future in a realistic fashion we need to come to grips with human nature as it exists, not as social engineers would like it to be.

By Randall Parker 2007 May 06 05:34 PM  Bioethics Reproduction
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2007 May 05 Saturday
Exercise Slows Weight Gain With Age

If you don't mind running 30 miles per week for years on end you can slow your weight gain.

The study, conducted by Paul Williams of the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), followed 6,119 men and 2,221 women who maintained their weekly running mileage (to within three miles per week) over a seven-year period. On average, the men and women who ran over 30 miles per week gained half the weight of those who ran less than 15 miles per week.

"To my knowledge, this is the only study of its type," says Williams, a staff scientist in Berkeley Lab's Life Sciences Division. "Other studies have tracked exercise over time, but the majority of people will have changed their exercise habits considerably."

The research is the latest report from the National Runners' Health Study, a 20-year research initiative started by Williams that includes more than 120,000 runners. It appears in the May 3 issue of the journal Medicine and Science in Sports and Exercise.

Guys, even if you run more than 30 miles a week (not gonna do it) you'll still gain more than half a pound annually. Over 40 years that adds up to 32 pounds. Ugh.

Specifically, between the time subjects entered the study and when they were re-contacted seven years later, 25-to-34-year-old men gained 1.4 pounds annually if they ran less than 15 miles per week. In addition, male runners gained 0.8 pounds annually if they ran between 15 and 30 miles per week, and 0.6 pounds annually if they ran more than 30 miles per week.

Is there a level of exercise at which people do not gain weight as they age? If so, what is that level?

Women who ran more than 30 miles a week gained more weight than men who did.

This trend is mirrored in women. Women between the ages of 18 and 25 gained about two pounds annually if they ran less than 15 miles per week, 1.4 pounds annually if they ran 15 to 30 miles per week, and slightly more than three-quarters of a pound annually if they ran more than 30 miles per week. Other benefits to running more miles each week included fewer inches gained around the waist in both men and women, and fewer added inches to the hips in women.

A chart on calories burned in various forms of exercise (also see here and here) suggests these joggers are burning up perhaps 100-120 calories per mile (the possible range is larger depending on weight and other factors). So the 30 mile per week runners might be burning 3000 calories per week or 150,000 calories per year. They burn about 150,000 calories to keep off maybe a pound per year? Maybe only 1% or 2% of the additional calories burned translate into a reduction in fat accumulation. Note I'm doing really rough calculations ignoring body size and other factors. We'd need to see numbers on weight gain of non-runners to make an exact calculation. But the amount of calories one needs to burn is pretty large if the goal is weight control.

The calories burnt running are only part of the story though. The runners probably have more muscle than non-exercisers. So they burn more calories when they are sitting still (muscles use energy even when not doing work). The exercise must increase their appetites almost as much as it increases their calorie burning.

Do the Amish farmers gain weight as they grow old? Or do any other higher exercise groups keep off the weight as they grow older?

Update: Is there some way using less exercise to shift the body into a state where it is less likely to accumulate fat? Maybe. Short high intensity interval training increases the amount of fat burnt in all exercise.

Researchers at McMaster University in Hamilton, Ontario, had the exercisers sprint for 30 seconds, then either stop or pedal gently for four minutes.

Such a stark improvement in endurance after 15 minutes of intense cycling spread over two weeks was all the more surprising because the volunteers were already reasonably fit. They jogged, biked or did aerobic exercise two to three times a week.

Doing bursts of hard exercise not only improves cardiovascular fitness but also the body’s ability to burn fat, even during low- or moderate-intensity workouts, according to a study published this month, also in the Journal of Applied Physiology. Eight women in their early 20s cycled for 10 sets of four minutes of hard riding, followed by two minutes of rest. Over two weeks, they completed seven interval workouts.

After interval training, the amount of fat burned in an hour of continuous moderate cycling increased by 36 percent, said Jason L. Talanian, the lead author of the study and an exercise scientist at the University of Guelph in Ontario. Cardiovascular fitness — the ability of the heart and lungs to supply oxygen to working muscles — improved by 13 percent.

But this research is too small in scale and in time interval to tell us anything about the long term effects of high intensity exercise for short periods of time. Will such a pattern of exercise reduce weight gain with age?

Update II: If exercise seems like too much trouble consumption of soy might turn up your metabolism and reduce weight.

To compare soy peptides with leptin, de Mejia’s graduate student Nerissa Vaughn, with the help of associate professor Lee Beverly, implanted cannulas in the brains of lab rats; they then injected leptin as a positive control. When the scientists could see their model was working, they injected two formulations of hydrolyzed soy protein and soy peptides so the scientists could monitor the effects of each on food intake and weight loss.

Injections were given three times a week for two weeks; during that time, the animals had unlimited access to food and water. Food intake was measured 3, 6, 12, 24, and 48 hours after injection, and the rats were weighed 24 and 48 hours after injection. All rats received the same amount of exercise, and all rats lost weight.

But, after the third injection, de Mejia and Vaughn noticed a significant weight loss in the group of animals that had received one of the soy hydrolysates, even though the animals hadn’t changed their eating habits. In this instance, soy protein appeared to have caused weight loss not by reducing food intake but by altering the rats’ metabolism.

The experiment not only showed that soy peptides could interact with receptors in the brain, it also demonstrated that eating less isn’t always the reason for weight loss, the researcher said.

While these scientists used injection the press release claims that other research has shown that increased soy consumption is correlated with reduced weight. I've not read that claim before. Does that ring a bell with anyone else? If you are familiar with that research please post a comment.

Update III: A friend who suffers from arthritis says that the long term costs of joint wear from running have to be considered when deciding how to keep off the weight. Many of those who already have bad knees, hips and backs can't go running 30 miles a week without suffering intense pain. But what about the younger ones with still good joints? Do they put themselves at greater risk of knee and hip arthritis if they run 30 miles a week?

Stem cell therapies to replenish aging joint stem cells will some day allow people to avoid osteoarthritis and other joint problems that come with age. If we already had the needed cell therapies then the long term advantage of running would be clearer cut. But in the mean time aerobic exercise in ways that reduce joint impact (e.g. swimming and perhaps exercise cycles?) might make more sense as a way to get the exercise with less wear and tear on the joints.

By Randall Parker 2007 May 05 06:17 PM  Aging Exercise Studies
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2007 May 03 Thursday
Noise Degrades Messages In Brain

Ever find a thought somehow gets lost in the noise? Our neurons suffer from noise effects when transmitting data.

Addressing a current issue in neuroscience, Aldo Faisal and Simon Laughlin from Cambridge University investigate the reliability of thin axons for transmitting information. They show that noise effects in ion channels in the brain are much larger than previously assumed – meaning the fidelity of transmission is compromised.

Neurons in the cerebral cortex of the brain can have a wiring density of up to 4km per mm3 by using incredibly thin axons as wires, with an average diameter of 0.3 micrometers (1ìm is one millionth of a meter). Although, as in computer chips, this miniaturization economizes on space and energy, it increases the noise introduced by thermodynamic fluctuations in a neuron's voltage-gated ion channels. Axons use action potential (AP) to transmit information fast and reliably to synapses, but the reliability of transmissions down fibers of less than 0.5 ìm in diameter was unknown until this paper.

The human brain is a pretty flawed instrument. Those who claim that human bodies must be the product of an intelligent designer obviously aren't looking at the human body from an engineering perspective. The deficiencies of the structure and function of the human body seem obvious though.

Looking forward a future generation of transhumans will gain many advantages over humans. Those advantages will come from intelligent design done by humans to improve our brains with better designs of brain components.

You can read the full article.

By Randall Parker 2007 May 03 10:54 PM  Brain Performance
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2007 May 01 Tuesday
$10 Device Synthesizes DNA

Polymerase chain reactions (PCRs) are widely used to synthesize DNA as part of DNA sequencing work. Dr. Victor Ugaz at Texas A&M University has found a way to speed up the PCR DNA copying process at very low cost.

A pocket-sized device that runs on two AA batteries and copies DNA as accurately as expensive lab equipment has been developed by researchers in the US.

The device has no moving parts and costs just $10 to make. It runs polymerase chain reactions (PCRs), to generate billions of identical copies of a DNA strand, in as little as 20 minutes. This is much faster than the machines currently in use, which take several hours.

The development of cheap miniature devices is the future of biotechnology and is going to do to biotechnology what miniaturization has done to computer technology. Therefore we should expect a huge acceleration of the rate at which biological science advances and the development of very cheap methods of repair of aged bodies.

Dr. Ugaz uses convection to move the PCR process through a series of steps.

Currently, PCR faces a time issue, as it is typically ran in a thermocycler, averaging between one and three hours. Using a convective flow system, the process runs faster and more efficient, using natural convection and buoyancy forces to create the required temperature cycles.

The abstract for Dr. Ugaz's grant application for this research from 2004 shows he's been working on this problem for a few years:

By eliminating the need for dynamic external temperature control, a convective flow-based system is capable of achieving performance equal to or exceeding that of conventional thermocyclers in a greatly simplified format, This level of simplicity is a significant departure from previous attempts to construct novel thermocycling equipment, where added complexities often far outweigh any potential performance gains, We propose a research effort targeted at developing a new generation of thermocycling equipment offering improved performance at a significantly lower cost, thereby making PCR practical for use in a wider array of settings.

Researchers like Dr. Ugaz who work on methods to speed up and miniaturize technology used to manipulate biological materials are going catalyze a revolution in biomedical science and biotechnology.

Thanks to Brock McCusick for the tip.

By Randall Parker 2007 May 01 10:38 PM  Biotech Advance Rates
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Pistachios Improve Blood Flow And Sugar

Pistachio consumption lowered blood pressure and improved vascular performance.

The diets included a Step I Diet – a standard heart healthy diet with 25 percent fat and 8 percent saturated fat, a diet containing 1.5 ounces of pistachios that was a Step I Diet with 30 percent total fat and 8 percent saturated fat and a diet containing 3 ounces of pistachios that was a Step I Diet containing 34 percent fat and 8 percent saturated fat. At the end of each four-week diet regime, the researchers measured blood pressure and total peripheral vascular resistance at rest and during two stress tests.

The two tests consisted of a physical test and a psychological test. The physical test consists of putting one foot in a bucket of ice water for 2.5 minutes. The psychological test asks participants to listen to two numbers, add them in their head and say the answer. Then they hear another number and they must add it to the second number they heard, not the sum they spoke.

Note these results go against the simple rule that more fats are bad. Nuts are a more complicated story in part because their fats are less saturated.

Pistachios reduced the effects of stress on blood pressure. Stressful conditions did not increase blood pressure as much in people who were on diets that included pistachios. Pistachios caused artery relaxation.

The researchers found that both pistachio containing diets reduced the stress effects on blood pressure, but that the 1.5 ounce pistachio diet reduced systolic blood pressure by 4.8 millimeters of mercury while the 3-ounce pistachio diet only reduced systolic blood pressure by 2.4 millimeters of mercury. The diets had no effect on normal, resting blood pressure.

"When we only look at blood pressure, these results are confusing," says West. "If it is the pistachios, why is it not dose related?"

When the researchers looked at total peripheral vascular resistance, it was clear that the 3-ounce diet caused greater relaxation of arteries. Because the body tightly regulates blood pressure, rather than allowing blood pressure to drop further, the heart compensated by pumping more forcefully.

The artery benefits might come from the high concentrations of arginine found in pistachios and some other nuts. Pistachios have two and a half grams of arginine in a cup. The arginine helps boost nitric acid which relaxes arteries.

This same study found that pistachios lower the bad forms of cholesterol.

The multi-week study, which received funding from the California Pistachio Commission , concluded that three ounces of pistachios a day reduced LDL levels by 11.6 percent, total cholesterol levels by 8.4 percent, and non-high density lipoproteins (non-HDL) by 11.2 percent.

Lower cholesterol, less reaction to stress, lower blood pressure. Does the arginine story get any better? A different study by the University of Toronto’s Dr. Cyril Kendall and Dr. David Jenkins (he who developed his "ape diet" to lower cholesterol in humans) finds that pistachios reduce blood sugar rise after high carbohydrate meals.

Drs. Jenkins and Kendall and their research colleagues studied 10 healthy individuals who participated in a number of acute dietary studies over the course of two months. After an overnight fast, participants were given a one-, two- or three-ounce serving of pistachios alone or served with a slice of white bread and blood sugar levels were measured over a two-hour period. The findings suggest that consumption of pistachios with a carbohydrate-rich meal significantly lowered the d blood glucose response. As consumption of pistachios increased, the blood sugar lowering response was enhanced. In addition, when pistachios were consumed alone, the rise in blood glucose was minimal.

The researchers also monitored the effect of pistachios consumed with different common carbohydrate foods on postprandial glycemia, or blood sugar levels after eating. The addition of pistachios to a number of other commonly consumed carbohydrate-rich foods – such as mashed potatoes, pasta and rice – also resulted in significant reductions in the blood sugar response, compared to when these foods were eaten alone.

These results are consistent with a larger body of research showing health benefits from consumption of nuts. Curiously, pistachios have more carbohydrates than a lot of other nuts. Yet they provided blood sugar benefits.

By Randall Parker 2007 May 01 09:16 PM  Aging Diet Studies
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