2008 October 31 Friday
Grapes Slow Development Of High Blood Pressure In Rats

Rats genetically engineered to develop high blood pressure developed it more slowly when grapes were added to their feed.

The researchers studied the effect of regular table grapes (a blend of green, red, and black grapes) that were mixed into the rat diet in a powdered form, as part of either a high- or low-salt diet. They performed many comparisons between the rats consuming the test diet and the control rats receiving no grape powder — including some that received a mild dose of a common blood-pressure drug. All the rats were from a research breed that develops high blood pressure when fed a salty diet.

In all, after 18 weeks, the rats that received the grape-enriched diet powder had lower blood pressure, better heart function, reduced inflammation throughout their bodies, and fewer signs of heart muscle damage than the rats that ate the same salty diet but didn't receive grapes. The rats that received the blood-pressure medicine, hydrazine, along with a salty diet also had lower blood pressure, but their hearts were not protected from damage as they were in the grape-fed group.

Says Mitchell Seymour, M.S., who led the research as part of his doctoral work in nutrition science at Michigan State University, "These findings support our theory that something within the grapes themselves has a direct impact on cardiovascular risk, beyond the simple blood pressure-lowering impact that we already know can come from a diet rich in fruits and vegetables." Seymour manages the U-M Cardioprotection Research Laboratory, which is headed by U-M heart surgeon Steven Bolling, M.D.

The researchers think flavanoids in grapes might be providing the heart protection.

"Although there are many natural compounds in the grape powder itself that may have an effect, the things that we think are having an effect against the hypertension may be the flavanoids – either by direct antioxidant effects, by indirect effects on cell function, or both. These flavanoids are rich in all parts of the grape - skin, flesh and seed, all of which were in our powder." Bolling explains.

You can get flavanoids from berries and cherries as well. The amount of grapes used is equivalent to a human eating 9 servings of grapes per day.

He notes that the popular DASH diet, which is low in salt and high in fruits and vegetables, has been proven to reduce mild high blood pressure without medication. The dose of whole table grape powder that was consumed in the study was roughly equivalent to a person eating nine human-sized servings of grapes a day. Currently, five to nine servings of fruits and vegetables are recommended as part of the DASH diet.

Other measures of heart function were better in the grape-fed group.

The researchers also measured the distortion of the heart size, weight and function that occurred over time – characteristics of heart failure – and found that the high-salt grape group had less of a change than the high-salt hydrazine group. Parameters related to the diastolic blood pressure – an important factor in human heart failure — and to the heart's relaxation during the diastolic phase also changed in just the high-salt grape group. Finally, the grape-fed rats had improved cardiac output, or more blood pumped per unit of time.

The researchers also looked for signs of inflammation, oxidative damage and other molecular indicators of cardiac stress. Again, the rats that received the high-salt grape diet had lower levels of these markers than rats that received the high-salt diet with hydrazine – and even the low-salt grape-eating rats had lower levels than the rats that received a low-salt diet alone.

Eat more fruits and vegetables or die before your time.

Update: A recent survey of grape health benefit research finds grapes provide health benefit in humans too.

So far, most of the evidence on grape polyphenols comes from laboratory experiments and animal studies. However, a few studies support the disease-preventing benefits of grapes in humans. Studies in patients treated with grape seed extracts have shown improvements in blood flow and cholesterol levels. In other studies, drinking Concord grape juice has improved measures of blood flow in patients with coronary artery disease and lowered blood pressure in patients with hypertension.

By Randall Parker 2008 October 31 05:30 AM  Aging Diet Heart Studies
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Might Resveratrol Cut Hereditary Breast Cancer Risk?

Resveratrol (which is sold over-the-counter at least in some countries) might work against breast cancer that is caused by hereditary mutation of the BRCA1 gene.

Dr. Deng and colleagues were interested in investigating the relationship among BRCA1, SIRT1 and Survivin. SIRT1 is a protein and histone deacetylase involved in numerous critical cell processes including metabolism, DNA repair and programmed cell death, known as apoptosis. Although SIRT1 has been implicated in tumorigenesis, no concrete role in cancer initiation or progression has been identified. Survivin is an apoptosis inhibitor that is dramatically elevated in many types of tumors. Research has suggested that Survivin may serve to maintain the tumor and promote growth.

The researchers found that BRCA1 functioned as a tumor suppressor by maintaining SIRT1 expression, which in turn inhibited Survivin expression. When BRCA1 was not functioning properly, SIRT levels decreased and Survivin levels increased, allowing BRCA1-deficient cells to overcome apoptosis and undergo malignant transformation.

They went on to show that the compound resveratrol strongly inhibited BRCA1-mutant tumor growth in cultured cells and animal models. Resveratrol is an important constituent of traditional Japanese and Chinese medicine that has recently been shown to inhibit some types of cancer by inducing apoptosis with very little associated toxicity. In the current paper, resveratrol enhanced SIRT1 activity, this leading to reduced Survivin expression and subsequent apoptosis of BRCA1 deficient cancer cells.

These findings identify SIRT1 and Survivin as downstream mediators of BRCA1-regulated tumor suppression and identify resveratrol as a potent inhibitor of BRCA1-mutant cancer cells. "Resveratrol may serve as an excellent compound for targeted therapy for BRCA1 associated breast cancers," says Dr. Deng.

If resveratrol really works in the way described there is a substantial chance that resveratrol might decrease the odds of getting breast cancer in the first place - especially among women who have the BRCA1 mutation that increases the odds of getting breast cancer. Resveratrol appears to substitute for properly formed BRCA1 and enhance SIRT1 which lowers the expression of Survivin. Survivin helps keep cells alive. So less Survivin causes more cancer cells to commit suicide.

Here is the abstract.

Germline mutations of BRCA1 predispose women to breast and ovarian cancers. However, the downstream mediators of BRCA1 function in tumor suppression remain elusive. We found that human BRCA1-associated breast cancers have lower levels of SIRT1 than their normal controls. We further demonstrated that mammary tumors from Brca1 mutant mice have low levels of Sirt1 and high levels of Survivin, which is reversed by induced expression of Brca1. BRCA1 binds to the SIRT1 promoter and increases SIRT1 expression, which in turn inhibits Survivin by changing the epigenetic modification of histone H3. Absence of SIRT1 blocks the regulation of Survivin by BRCA1. Furthermore, we demonstrated that activation of Sirt1 and inhibition of Survivin expression by resveratrol elicit a more profound inhibitory effect on Brca1 mutant cancer cells than on Brca1-wild-type cancer cells both in vitro and in vivo. These findings suggest that resveratrol treatment serves as an excellent strategy for targeted therapy for BRCA1-associated breast cancer.

I periodically mull over the possibility of taking resveratrol for its various reported benefits. Still haven't crossed over to taking it yet. I expect I'll take it when I get older and my risk of cancer goes up.

By Randall Parker 2008 October 31 04:42 AM  Aging Diet Resveratrol
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2008 October 29 Wednesday
Men Detect Infidelities Better Than Women

He's going to figure out your cheating heart.

UNFAITHFUL women beware. Chances are your male partner is on your case. In fact, he is likely to suspect infidelities even when you have kept to the straight and narrow. The flip side is that to counter this constant vigilance, women may be better than men at concealing illicit liaisons.

Paul Andrews at Virginia Commonwealth University in Richmond and colleagues gave 203 young heterosexual couples confidential questionnaires asking them whether they had ever strayed, and whether they suspected or knew their partner had strayed. In this, 29 per cent of men said they had cheated, compared with 18.5 per cent of women.

The men were better than women at judging fidelity. "Eighty per cent of women's inferences about fidelity or infidelity were correct, but men were even better, accurate 94 per cent of the time," says Andrews. They were also more likely to catch out a cheating partner, detecting 75 per cent of the reported infidelities compared with 41 per cent discovered by women (Human Nature, vol 19, p 347). However, men were also more likely to suspect infidelity when there was none.

Andrews says this makes evolutionary sense because unlike women, men can never be certain a baby is theirs. "Men have far more at stake," he says. "When a female partner is unfaithful, a man may himself lose the opportunity to reproduce, and find himself investing his resources in raising the offspring of another man."

The next step in this evolutionary arms race? People will genetically test their prospective partners in order to avoid those who have genes that make them more likely to stray. Though men with high status yet with genetic variants that cause a cheating heart will still be able to get women who would rather have a high status cheating mate than a low status faithful mate.

Also, cheaters will look for genetic profiles of prospective mates who either have genetically caused weaknesses in ability to detect cheating or who have genetic profiles that suggest a willingness to look the other way. So maybe the net result will be more happiness and more cheating.

By Randall Parker 2008 October 29 09:13 PM  Brain Sexuality
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Brain Scans Of Reactions To Faces Predict Election Winners

You might believe you have very sophisticated reasons for favoring one political candidate or the other. And that might even be true. But did those sophisticated reasons precede or follow your brain's reaction to the faces of the candidates? Brain scans of people viewing photos unknown politicians (and even their stated reactions to the pictures) can predict election outcomes.

PASADENA, Calif.-- Brain-imaging studies reveal that voting decisions are more associated with the brain's response to negative aspects of a politician's appearance than to positive ones, says a team of researchers from the California Institute of Technology (Caltech), Scripps College, Princeton University, and the University of Iowa. This appears to be particularly true when voters have little or no information about a politician aside from their physical appearance.

The research was published online in the journal Social Cognitive and Affective Neuroscience (http://scan.oxfordjournals.org) on October 28.

In general elections some vote the straight party ticket. So their assessments of faces do not matter. But even the consistent partisan voters evaluate ideologically similar candidates in primaries (at least in electoral systems that have primaries). In those primaries the partisans probably vote on appearances just as the middle-of-the-roaders do in general elections.

You do not even need brain scans to predict election outcomes. Just show people pictures for a tenth of a second. We do not need to suffer thru listening to political commentators babbling for months. We can get the same results in seconds.

Using a functional magnetic resonance imaging (fMRI) scanner at the Caltech Brain Imaging Center, the researchers obtained high-resolution images of brain activation as volunteers made decisions about politicians based solely on their pictures.

The researchers conducted two independent studies using different groups of volunteers viewing the images of different politicians. Volunteers were shown pairs of photos, each with a politician coupled with their opponent in a real election in 2002, 2004, or 2006. Importantly, none of the study subjects were familiar with the politicians whose images they viewed.

In some experiments, the volunteers had to make character-trait judgments about the politicians--for example, which of the two politicians in the pair looked more competent to hold congressional office, or which looked more likely to physically threaten the volunteer. In other experiments, volunteers were asked to cast their vote for one politician in the pair; once again, their decisions were based only on the politicians' appearances.

The results correlated with actual election outcomes. For example, politicians who were thought to look the most physically threatening in the experiment were more likely to have actually lost their elections in real life. The correlation held true even when volunteers saw the politicians' pictures for less than one tenth of a second.

Importantly, the pictures of politicians who lost elections, both in the lab and in the real world, were associated with greater activation in key brain areas known to be important for processing emotion. This was true when volunteers simply voted and also when they closely examined the politicians' pictures for character traits. The studies suggest that negative evaluations based only on a politician's appearance have some effect on real election outcomes--and, specifically, may influence which candidate will lose an election. This influence appears to be more uniform than the influence exerted by positive evaluations based on appearance.

But we'll keep on having elections because most people don't want to admit they are using appearances to choose leaders.

My question: How accurate are people at reading character in faces? Do the politicians with more threatening faces really govern worse once in office? Do they have different personality types compared to those with less threatening faces?

By Randall Parker 2008 October 29 09:08 PM  Brain Society
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Vitamin E And Selenium Fail To Cut Prostate Cancer Risk

A big trial fails to find confirmation for earlier reports of a reduced prostate cancer risk from selenium and vitamin E.

Initial, independent review of study data from the Selenium and Vitamin E Cancer Prevention Trial (SELECT), funded by the National Cancer Institute (NCI) and other institutes that comprise the National Institutes of Health shows that selenium and vitamin E supplements, taken either alone or together, did not prevent prostate cancer. The data also showed two concerning trends: a small but not statistically significant increase in the number of prostate cancer cases among the over 35,000 men age 50 and older in the trial taking only vitamin E and a small, but not statistically significant increase in the number of cases of adult onset diabetes in men taking only selenium. Because this is an early analysis of the data from the study, neither of these findings proves an increased risk from the supplements and both may be due to chance.

Other dietary changes to cut prostate cancer risk look more promising. Eat more fruits and vegetables and omega 3 fatty acids. Eat less saturated fats from meat.

By Randall Parker 2008 October 29 07:52 PM  Aging Diet Cancer Studies
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Immune System Changes Emotional Reactions

Hello again puppets. Add immune system mast cells to our list of puppeteers. Anyone still think we have free will?

In the first study ever to genetically link the immune system to normal behavior, scientists at Rockefeller and Columbia universities show that mast cells, known as the pharmacologic bombshells of the immune system, directly influence how mice respond to stressful situations. The work, to appear this week in The Proceedings of The National Academy of Sciences and to be highlighted in Science, chips away at the increasingly stale idea that the two most complex systems in the body have entirely separate modes of operation.

Eight years ago, scientists from Columbia University discovered that mast cells travel to the brain from other organs early on in development. “We now knew that mast cells resided in the brain but we didn’t know their function,” says Rockefeller University’s Donald Pfaff, head of the Laboratory of Neurobiology and Behavior. “But we know that they synthesize a large number of important chemical mediators that could potentially have severe neurophysiological effects.”

Since the immune system ages and becomes less vigorous that suggests that aging of the immune system alters our emotional reactions.

If aging people could get their immune systems rejuvenated they might become more adventurous.

In their work, Pfaff and postdoc Ana Ribeiro, and the Columbia team, led by senior author Rae Silver and graduate student Kate Nautiyal, bred mice that lacked mast cells and compared their behavior in stressful situations to the behavior of mice that had a full or a moderate arsenal of mast cells. The researchers observed how willing the mice were to navigate open and lit environments and high spaces, which mice find anxiety-producing. In the wild, if a mouse is down in its own burrow, it’s not visible to predation. But if it’s bold, that is, if it has low anxiety, it will go out where it can potentially be seen by predators and hunted.

The results were striking. When the researchers placed the mice in an elevated maze with four long arms -- two simulated a canyon and the other two a cliff -- mice that lacked mast cells preferred to stay in the canyons, entering and investigating the doors to the cliffs significantly fewer times than mice with mast cells. When placed in a square box, mast cell-deficient mice preferred to scuttle against the walls, and were more hesitant to venture out to the center of the box than mice with mast cells. They also defecated more, a physiological sign of anxiety. However, the genetically different mice did not show differences in overall arousal or locomotion, suggesting that their behavioral changes were specific to their anxious state.

So an unhealthy immune system can increase anxiety. Do anxious people get colds and flus more often?

By Randall Parker 2008 October 29 08:00 AM  Brain Emotions
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Brain Scans Of People Full Of Hate Show Unique Hate Signature

Coming from Professor Semir Zeki and John Romaya of the Wellcome Laboratory of Neurobiology at the University College London, a new research paper in Plos One on how hatred activates and deactivates areas of the brain shows hate creates a unique pattern of brain activates which includes some overlap with brain areas activated by love.

In this work, we address an important but unexplored topic, namely the neural correlates of hate. In a block-design fMRI study, we scanned 17 normal human subjects while they viewed the face of a person they hated and also faces of acquaintances for whom they had neutral feelings. A hate score was obtained for the object of hate for each subject and this was used as a covariate in a between-subject random effects analysis. Viewing a hated face resulted in increased activity in the medial frontal gyrus, right putamen, bilaterally in premotor cortex, in the frontal pole and bilaterally in the medial insula. We also found three areas where activation correlated linearly with the declared level of hatred, the right insula, right premotor cortex and the right fronto-medial gyrus. One area of deactivation was found in the right superior frontal gyrus. The study thus shows that there is a unique pattern of activity in the brain in the context of hate. Though distinct from the pattern of activity that correlates with romantic love, this pattern nevertheless shares two areas with the latter, namely the putamen and the insula.

Hatred does not activate the amygdala which is activated by fear.

It is important to note that the pattern revealed is distinct from that of other, closely related, emotions such as fear, anger, aggression and danger, even though it shares common areas with these other sentiments. Thus, the amygdala which is strongly activated by fear (Noesselt et al. 2005 [9], Morris et al. 2002 [10], Hadjikhani et al. 2008 [11]) and by aggression (Beaver et al., 2008 [12]) was not activated in our study. Nor were the anterior cingulate, hippocampus, medial temporal regions, and orbitofrontal cortex, apparently conspicuous in anger and threat (Denson et al. 2008 [13]; Bufkin and Luttrell 2007 [14]; McClure et al. 2004 [15]), evident in our study. It would thus seem that, though these sentiments may constitute part of the behaviour that results from hatred, the neural pathways for hate are distinct.

Parts of the brain involved in motor function get activated - perhaps so one can move in and attack the object of one's hate?

The 'hate circuit' includes structures in the cortex and in the sub-cortex and has components that are important in generating aggressive behaviour, and translating this into action through motor planning, as if the brain becomes mobilised to take some action. It also involves a part of the frontal cortex that has been considered critical in predicting the actions of others, probably an important feature when one is confronted by a hated person.

The subcortical activity involves two distinct structures, the putamen and insula. The former, which has been implicated in the perception of contempt and disgust, may also be part of the motor system that is mobilised to take action, since it is known to contain nerve cells that are active in phases preparatory to making a move.

Professor Zeki added: "Significantly, the putamen and insula are also both activated by romantic love. This is not surprising. The putamen could also be involved in the preparation of aggressive acts in a romantic context, as in situations when a rival presents a danger. Previous studies have suggested that the insula may be involved in responses to distressing stimuli, and the viewing of both a loved and a hated face may constitute such a distressing signal.

While love shuts down areas of the brain associated with judgment and reasoning by contrast those consumed with hate have very active reasoning facilities. It takes logic to figure out how to attack your enemy. So that makes sense. Only those in love think they can afford to let their guard down, become zombies, and feel bliss around the object of their affection.

"A marked difference in the cortical pattern produced by these two sentiments of love and hate is that, whereas with love large parts of the cerebral cortex associated with judgment and reasoning become de-activated, with hate only a small zone, located in the frontal cortex, becomes de-activated. This may seem surprising since hate can also be an all-consuming passion, just like love. But whereas in romantic love, the lover is often less critical and judgmental regarding the loved person, it is more likely that in the context of hate the hater may want to exercise judgment in calculating moves to harm, injure or otherwise extract revenge.

In countries where suspected criminals have no right to privacy or right to keep silent brain scans could be used to determine whether a suspected killer hated his victim and by how much.

"Interestingly, the activity in some of these structures in response to viewing a hated face is proportional in strength to the declared intensity of hate, thus allowing the subjective state of hate to be objectively quantified. This finding may have legal implications in criminal cases, for example."

One could imagine a police state in which opponents of the regime get tested with brain scans and pictures of dictators to identify enemies of the state. With more time it will become possible for governments to turn hatred into love. Then all enemies of the state will get turned into supporters of it. Of course, individuals will try to do this on a smaller scale as well.

Contrast these results with the research into love. See my previous posts Love Deactivates Brain Areas For Fear, Planning, Critical Social Assessment, Love Like Addiction In Brain Scans, What Brain Scans Of People Falling In Love Tell Us, Romantic Love Seen As Motivation Or Drive Rather Than Emotional State, and Love Is Blind: Couples In Love Can't Identify Who Else Is In Love.

By Randall Parker 2008 October 29 12:09 AM  Brain Emotions
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2008 October 28 Tuesday
Interrupts Cut Into Work Productivity

A New York Times article looks at work interrupts as enemies of productivity.

A 2005 study, “No Task Left Behind? Examining the Nature of Fragmented Work,” found that people were interrupted and moved from one project to another about every 11 minutes. And each time, it took about 25 minutes to circle back to that same project.

Interestingly, a study published last April, “The Cost of Interrupted Work: More Speed and Stress,” found that “people actually worked faster in conditions where they were interrupted, but they produced less,” said Gloria Mark, a professor of informatics at the University of California at Irvine and a co-author of both studies. And she also found that people were as likely to self-interrupt as to be interrupted by someone else.

“As observers, we’ll watch, and then after every 12 minutes or so, for no apparent reasons, someone working on a document will turn and call someone or e-mail,” she said. As I read that, I realized how often I was switching between writing this article and checking my e-mail.

Professor Mark said further research needed to be done to know why people work in these patterns, but our increasingly shorter attention spans probably have something to do with it.

What I wonder: Do we interrupt ourselves because it is in our nature to periodically look around and pay attention to other things in our environment? Do modern working conditions create demands upon us that clash with the mind's own instincts? Do we need to somehow suppress our instinctive tendencies in order to maximize our productivity?

Her study found that after only 20 minutes of interrupted performance, people reported significantly higher stress, frustration, workload, effort and pressure.

So then how much of our stress and frustration stems from inflicting ourselves with interrupts of checking mail, checking web sites, sending text messages, and answering cell phone calls? I am amazed at how many times certain co-workers let themselves get interrupted by cell phone calls. I get interrupted enough by people in front of me without the need to get still more interrupts from people in other locations.

Also see my previous posts Brain Limits Ability To Multitask Interruptions, Work Distractions Lower Effective IQ, and Brain Scans Indicate When Best To Multitask.

By Randall Parker 2008 October 28 11:10 PM  Brain Performance
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2008 October 27 Monday
Face Masks And Hand Sanitizers Slash Flu Risks

If a deadly flu pandemic breaks out make sure you have plenty of face masks and hand cleansers to cut your risks.

ANN ARBOR, Mich.---Wearing masks and using alcohol-based hand sanitizers may prevent the spread of flu symptoms by as much as 50 percent, a landmark new study suggests.

In a first-of-its-kind look at the efficacy of non-pharmaceutical interventions in controlling the spread of the flu virus in a community setting, researchers at the University of Michigan School of Public Health studied more than 1,000 student subjects from seven U-M residence halls during last year's flu season.

"The first-year results (2006-2007) indicate that mask use and alcohol-based hand sanitizer help reduce influenza- like illness rates, ranging from 10 to 50 percent over the study period," said Allison Aiello, co-principal investigator and assistant professor of epidemiology at the U-M SPH. Dr. Arnold Monto, professor of epidemiology, is also a principal investigator of the study.

Aiello stressed the first year of the two-year project, called M-Flu, was a very mild flu season and only a few cases were positive for flu, so results should be interpreted cautiously. Ongoing studies will test for other viruses that may be responsible for the influenza-like illness symptoms observed, she said.

"Nevertheless, these initial results are encouraging since masks and hand hygiene may be effective for preventing a range of respiratory illnesses," Aiello said.

If the pandemic is sufficiently lethal I would advise more radical measures such as working at home and taking other steps to hugely decrease your exposure to others. The masks and hand washing help those who go into public places in close contact with others. But staying away from people is the best protection. Wait for a vaccine to get developed before putting your life at risk. One way to keep the economy going and your income flowing during a pandemic is workplace cocooning. Groups of people could live and work together in quarantine zones.

By Randall Parker 2008 October 27 11:23 PM  Pandemic Prepare Personal
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Hormones Predict Menopause Years In Advance

Hey ladies. Those ticking biological clocks are getting easier to hear with hormone tests.

"In the end, this information can change the way we do business," said MaryFran Sowers, professor in the U-M School of Public Health Department of Epidemiology. "The information provides a roadmap as to how fast women are progressing through the different elements of their reproductive life."

A research team headed by Sowers examined the naturally occurring changes in three different biomarkers over the reproductive life of more than 600 women: follicle-stimulating hormone (FSH), anti-Mullerian hormone (AMH) and inhibin B.

Researchers found that the biomarker AMH declined to a very low or non-measurable level five years prior to the final menstrual period. This decline pinpoints a critical juncture in which a woman probably has so few follicles (eggs) that her fertility becomes increasingly questionable, Sowers said. They found that the changes in AMH and inhibin B concentrations were predictive of the time to menopause.

The research team also measured and reported the rates of change in FSH and used the information to identify different reproductive stages. Based on a woman's age and the level of FSH in the blood, researchers were able to describe four different stages that occur for women from their late reproductive period to the time of their final menstrual period.

It would be a lot more helpful if the predictions could be done for longer periods of time before infertility. This would allow better planning and ladies could decide when to settle for Mr. Close Enough.

By Randall Parker 2008 October 27 11:20 PM  Aging Mechanisms
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Whole Grains Cut Heart Risks

Don't eat that white bread.

October 27, 2008, St. Louis, MO – - About 5 million people in the United States suffer from heart failure (HF). While some reports indicate that changes to diet can reduce HF risk, few large, prospective studies have been conducted. In a new study researchers observed over 14,000 participants for more than 13 years and found that whole grain consumption lowered HF risk, while egg and high-fat dairy consumption raised risk. Other food groups did not directly affect HF risk. The results are published in the November 2008 issue of the Journal of the American Dietetic Association.

Diet is among the prominent lifestyle factors that influence major HF risk factors: coronary artery disease, obesity, diabetes and insulin resistance and hypertension. Using data from the Atherosclerosis Risk in Communities (ARIC) study, researchers from the Division of Epidemiology and Community Health, University of Minnesota and the Department of Epidemiology and Cardiovascular Diseases Program, University of North Carolina, analyzed the results of baseline exams of more than 14,000 White and African American adults conducted in 1987-89, with follow-up exams completed during 1990-92, 1993-95, and 1996-98. Four field centers participated in the study: Forsyth County, NC; Jackson, MS; northwest Minneapolis suburbs, MN; and Washington County, MD. The study also collected demographic characteristics and lifestyle factors, as well as other medical conditions such as cardiovascular disease, diabetes and hypertension.

Beware of eggs. Avoid milk fat.

Writing in the article, Jennifer A. Nettleton, Ph.D., states, "Although risk estimates were modest (7% lower risk per 1-serving increase in whole grain intake; 8% greater risk per 1-serving increase in high-fat dairy intake; 23% greater risk per 1-serving increase in egg intake), the totality of literature in this area suggests it would be prudent to recommend that those at high risk of HF increase their intake of whole grains and reduce intake of high-fat dairy and eggs, along with following other healthful dietary practices consistent with those recommended by the American Heart Association."

One of the reasons some potentially beneficial dietary factors tend not to show up in big dietary studies is that some potentially healthy foods aren't eaten much. How many people eat nuts or berries every day? I happen to eat berries every day. But I'm a statistical outlier.

If we are going to go to the trouble of genetically engineering foods to have more healthful compounds in them then we need to know which compounds would be best to engineer into foods. Are anthocyanins really the ticket?

In this study the scientists expressed two genes from snapdragon that induce the production of anthocyanins in snapdragon flowers. The genes were turned on in tomato fruit. Anthocyanins accumulated in tomatoes at higher levels than anything previously reported for metabolic engineering in both the peel and flesh of the fruit. The fruit are an intense purple colour.

The scientists tested whether these elevated levels actually had an effect on health. In a pilot test, the lifespan of cancer-susceptible mice was significantly extended when their diet was supplemented with the purple tomatoes compared to supplementation with normal red tomatoes.

It'll be easier to eat healthily 20 years from now both because we'll know better what helps and also because food will be genetically engineered to contain what helps and not to contain what hurts.

By Randall Parker 2008 October 27 11:12 PM  Aging Diet Heart Studies
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Color Red Makes Men Hot For Women

Hi puppets. How are you all doing today? Geppetto says the color red makes men hot for women. When the men see red they charge for the flag.

A groundbreaking study by two University of Rochester psychologists to be published online Oct. 28 by the Journal of Personality and Social Psychology adds color—literally and figuratively—to the age-old question of what attracts men to women.

Through five psychological experiments, Andrew Elliot, professor of psychology, and Daniela Niesta, post-doctoral researcher, demonstrate that the color red makes men feel more amorous toward women. And men are unaware of the role the color plays in their attraction.

The research provides the first empirical support for society's enduring love affair with red. From the red ochre used in ancient rituals to today's red-light districts and red hearts on Valentine's Day, the rosy hue has been tied to carnal passions and romantic love across cultures and millennia. But this study, said Elliot, is the only work to scientifically document the effects of color on behavior in the context of relationships.

Did red hair get selected for because it made women look more hot to men?

Men who think they respond to women in a thoughtful and sophisticated manner are deluding themselves.

Although this aphrodisiacal effect of red may be a product of societal conditioning alone, the authors argue that men's response to red more likely stems from deeper biological roots. Research has shown that nonhuman male primates are particularly attracted to females displaying red. Female baboons and chimpanzees, for example, redden conspicuously when nearing ovulation, sending a clear sexual signal designed to attract males.

"Our research demonstrates a parallel in the way that human and nonhuman male primates respond to red," concluded the authors. "In doing so, our findings confirm what many women have long suspected and claimed – that men act like animals in the sexual realm. As much as men might like to think that they respond to women in a thoughtful, sophisticated manner, it appears that at least to some degree, their preferences and predilections are, in a word, primitive."

We are just smart monkeys.

Women don't get turned on by red in men. Red didn't make women seem any more intelligent or kind.

In the final study, the shirt of the woman in the photograph, instead of the background, was digitally colored red or blue. In this experiment, men were queried not only about their attraction to the woman, but their intentions regarding dating. One question asked: "Imagine that you are going on a date with this person and have $100 in your wallet. How much money would you be willing to spend on your date?"

Under all of the conditions, the women shown framed by or wearing red were rated significantly more attractive and sexually desirable by men than the exact same women shown with other colors. When wearing red, the woman was also more likely to score an invitation to the prom and to be treated to a more expensive outing.

The red effect extends only to males and only to perceptions of attractiveness. Red did not increase attractiveness ratings for females rating other females and red did not change how men rated the women in the photographs in terms of likability, intelligence or kindness.

What color makes men more attractive?

By Randall Parker 2008 October 27 11:03 PM  Brain Sexuality
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2008 October 26 Sunday
Assay Tools Watch Gene Expression During Common Cold Infection

Here's an example of scientific questions biologists can now ask due to advances in assaying tools. Scientists can watch the effects of a rhinovirus (one of the several families of viruses that cause the common cold) on human gene expression in the nasal passages. This will help guide development of treatments to reduce the symptoms and spread of viruses that cause the common cold.

"Advances in genomics technology now allow us to analyze tens of thousands of genes in the same amount of time required to analyze just a handful of genes just a decade ago," said Jay Tiesman, P&G Genomics Group Leader and study author.

Forty-eight hours after inoculation, the expression of 6,530 genes in infected volunteers were significantly either up-regulated or down-regulated compared to the same genes in the control group. In other words, rhinovirus infection triggered a massive immune response in the nasal mucosa. Because rhinovirus is not as destructive as other more serious viral infections, this response appears to be disproportionate to the threat.

Gene expression testing and gene sequencing tools have become so powerful so quickly that we aren't yet seeing the results at the clinical level of treatments. Advanced assaying tools are enabling the asking and answering of questions which couldn't be approached a decade ago. Because of the continuing big increases in ability to measure gene expression I expect many heretofore incurable diseases to finally become curable. Even the common cold will meet its defeat.

The cold causes an excess of inflammation.

The researchers classified the active genes according to function, and found many involved in a process known as chemotaxis, which recruits various immune cells to the site of infection. These particular genes have been correlated with symptoms such as inflammation, congestion and runny nose. Other groups of active genes have also been classified; among them are genes which make antiviral compounds thought to help thwart infections.

"This study shows that after rhinovirus infection, cold symptoms develop because parts of our immune system are in overdrive," said Lynn Jump, Principal Researcher at P&G and study author. "The findings are important because they provide us a blueprint for developing the ideal cold treatment: one that maintains the body's natural antiviral response while normalizing the inflammatory response."

I would say the ideal cold treatment would be a vaccine that vaccinates against a large variety of cold viruses.

By Randall Parker 2008 October 26 11:20 PM  Biotech Assay Tools
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Alemtuzumab Stops Multiple Sclerosis?

We might be looking at a cure for a major auto-immune disorder and the treatment might eventually work for other auto-immune diseases. Monoclonal antibody drug Alemtuzumab prevents M.S. recurrence in a substantial portion of patients.

A drug which was developed in Cambridge and initially designed to treat a form of leukaemia has also proven effective against combating the debilitating neurological disease multiple sclerosis (MS).

The study, led by researchers from the University of Cambridge, has found that alemtuzumab not only stops MS from advancing in patients with early stage active relapsing-remitting multiple sclerosis (RRMS) but may also restore lost function caused by the disease. The findings were published today in the New England Journal of Medicine.

Alemtuzumab has a long connection with Cambridge, England. In 1984, Cambridge scientist Cesar Milstein was awarded the Nobel Prize for Physiology or Medicine, jointly with George Kohler, for inventing the technology to make large quantities of a desired type of monoclonal antibody. Further work in Cambridge, by Herman Waldmann and Greg Winter, led to the production of the first humanised monoclonal antibody for use as a medicine, Campath-1H, now known as alemtuzumab. It has been licensed for the treatment of chronic lymphocytic leukaemia, and has also been tested in several diseases where the immune system is overactive, such as multiple sclerosis.

The new study, which was funded by Genzyme and Bayer Schering Pharma AG, Germany , found that alemtuzumab reduces the number of attacks experienced by people with relapsing-remitting multiple sclerosis by 74 per cent over and above that achieved with interferon beta-1a, one of the most effective licensed therapies for similar cases of MS. More importantly, alemtuzumab also reduced the risk of sustained accumulation of disability by 71 per cent compared to interferon beta-1a.

Additionally, the investigators showed that many individuals in the trial who received alemtuzumab recovered some of their lost functions and so were less disabled after three years than at the beginning of the study, in contrast to worsening disability in the interferon beta-1a treated patients. These findings suggest that alemtuzumab may allow damaged brain tissue to repair, enabling the recovery of neurologic functions lost following poor recovery from previous MS attacks.

One patient died from a complication (idiopathic thrombocytopenic purpura (ITP)) of the treatment. But now that the complication is known the hope is that it can be recognized sooner and better managed.

The drug works by wiping out lymphocytes. This has to cause problems with greater risk from infectious diseases. It is a rather broad wiping out since the drug doesn't have specificity for just those immune cells that are attacking the brain.

The treatment works by destroying all the patients' lymphocytes, the T-and B-cells that normally fight infections, but which mistakenly attack nerves and brain tissue in MS patients.

Following the treatment, the immune system grows back, but without the cells that cause MS. "It's as though you've re-booted the immune system, so it's better behaved," Coles says.

The whole process takes about three to four years, adds Coles, who is hopeful that the drug might also be able to help patients with other auto-immune diseases such as diabetes and lupus.

The Phase III trial for this therapy is currently recruiting patients.

A more ideal auto-immune disease treatment would target only those immune cells attacking the body. But that's a much harder problem to solve than the problem of wiping out all T and B cells.

By Randall Parker 2008 October 26 07:27 PM  Biotech Therapies
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People Can Estimate Male Strength From Face Pictures

Our brains can estimate upper body strength for fighting just from facial pictures. The idea here is that our ancestors needed to know when to fight or back off. So we have this innate ability.

(Santa Barbara, Calif.) –– For our ancestors, misjudging the physical strength of a would-be opponent might have resulted in painful –– and potentially deadly –– defeat.

Now, a study conducted by a team of scientists at the University of California, Santa Barbara has found that a mechanism exists within the human brain that enables people to determine with uncanny accuracy the fighting ability of men around them by honing in on their upper body strength. What's more, that assessment can be made even when everything but the men's faces are obscured from view. A paper highlighting the researchers' findings appears in the current issue of the Proceedings of the Royal Society.

"Assessing fighting ability was important for our ancestors, and the characteristic that the mind implicitly equates with fighting ability is upper body strength," said Aaron Sell, a postdoctoral fellow at UCSB's Center for Evolutionary Psychology and the paper's lead author. "That's the component of strength that's most relevant to premodern combat. The visual assessment of fighting ability is almost perfectly correlated with the perception of strength, and both closely track actual upper body strength. What is a bit spooky is that upper body strength can even be read on a person's face.

Maybe facial muscles get built up along with upper chest and arm muscles? Or necks become thicker? Or testosterone levels determine average muscularity as well as extent of masculine features in faces such as thick bone above the eyes.

Some major names in evolutionary psychology (Cosmides and Tooby at UCSB) were involved in this work.

Sell conducted the study with Leda Cosmides, a professor of psychology and co-director of the Center for Evolutionary Psychology; John Tooby, a professor of anthropology and also co-director of the Center for Evolutionary Psychology; Michael Gurven, an associate professor of anthropology; and graduate students Daniel Sznycer and Christopher von Rueden.

Perception of fighting ability as guessed from facial pictures correlated with measured upper body weight lifting capacity.

When the photographs depicted men whose strength had been measured precisely on weight-lifting machines, the researchers found an almost perfect correlation between perceptions of fighting ability and perceptions of strength. "When you see that kind of correlation it's telling you you're measuring the same underlying variable," said Tooby.

They also found that perceptions of strength and fighting ability reflected the target's actual strength, as measured on weight-lifting machines at the gym. In other sections of the study, the researchers showed that this result extended far beyond the gym. Both men and women accurately judge men's strength, whether those men are drawn from a general campus population, a hunter-horticulturalist group in Bolivia, or a group of herder-horticulturalists living in the Argentinian Andes.

Imagine future humans whose upper body strength and facial features become basically disconnected from each other (that can already happen with steroid usage). Innate ability to generalize from facial features won't always work. But there's not an obvious genetic fix to do for future offspring since the current rules that our brain uses will still work for some people and any genetic change in how we analyze facial features will just change which humans we make the errors about. Maybe future humans will just remove that capability in their offspring.

By Randall Parker 2008 October 26 06:56 PM  Brain Innate
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Nicotine Addicts Have Genetically Lower Taste Sensitivity

Genetically determined sense of taste influences one's risk to become a nicotine addict.

CHARLOTTESVILLE, Va., October 13, 2008 - Could an aversion to bitter substances or an overall heightened sense of taste help protect some people from becoming addicted to nicotine? That's what researchers at UVA have found using an innovative new method they've developed to analyze the interactions of multiple genetic and environmental factors.  Their findings one day may be key in identifying people at risk for nicotine dependence.

In a study published in the October 10, 2008 issue of The American Journal of Human Genetics, University of Virginia Health System researchers report that two interacting genes related to bitter taste sensitivity, TAS2R16 and TAS2R38, play an important role in a person's development of nicotine dependence and smoking behavior.  Researchers found that people with higher taste sensitivity aren't as likely to become dependant on nicotine as people with decreased taste sensitivity.

Greater taste sensitivity might discourage cigarette smoking by making tobacco smoke taste more bitter.

It's long been known that a person's ability to taste bitter substances plays a crucial role in the rejection of potentially toxic foods, but taste sensitivity varies widely among individuals and between ethnic groups.

This is yet another way in which genes control human behavior without our being aware of it.

By Randall Parker 2008 October 26 05:21 PM  Brain Addiction
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2008 October 25 Saturday
Sleep Deprivation Enhances False Memory Retrieval

In a Plos One paper some Swiss and German researchers report in a paper entitled Sleep Loss Produces False Memories that sleep deprivation at time of retrieval enhanced false memories. Don't trust your memories when you are tired. Caffeine prevents the inaccurate retrievals.

People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a) as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b) as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., “night”, “dark”, “coal”,…), lacking the strongest common associate or theme word (here: “black”). Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss.

Researchers at the Washington University Memory Lab have shown that to optimize learning it is better to be tested on material than to study material a second time. Retrieval enhances memory consolidation. Also, there are optimal intervals for retesting. Well, my guess is that if you try to get tested when you are tired you'll not just recall less correctly then but also reduce the accuracy of future attempts to recall the same material. So sleep well before getting tested.

By Randall Parker 2008 October 25 10:11 PM  Brain Memory
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2008 October 23 Thursday
More Methylation In Suicide Brain Genomes

Methyl groups placed on the DNA backbone of our genomes regulate gene expression. People who commit suicide have more methylation on a gene that produces a receptor for a neurotransmitter. Maybe a reduction in the amount of that neurotransmitter receptor causes depression and suicide.

There are an increasing variety of epigenetic mechanisms that have been described, including the regulation of gene function via the methylation or demethylation of DNA. The study by Drs. Michael Poulter and Hymie Anisman and colleagues in the October 15th issue of Biological Psychiatry illustrates one exciting new example in this area of research, an epigenetic study of depression/suicide. The researchers compared the brain tissues of those who had major depressive disorder and committed suicide to those from a control group who died suddenly, from heart attacks and other causes.

They found the genome in people who have committed suicide as a result of major depression was being chemically modified by a process that is normally involved in regulating cell development. As Poulter explains, "We have about 40,000 genes in every cell and the only reason a skin cell becomes a skin cell as opposed to a heart cell is because only a fraction of the genes are being expressed, and the other genes not being expressed are shut down by this genetic process of DNA methylation." The rate of methylation in the suicide brains was found to be nearly ten times that of the control group, and the gene being shut down was a neurotransmitter receptor that plays a major role in regulating behavior. John H. Krystal, M.D., Editor of Biological Psychiatry and affiliated with both Yale University School of Medicine and the VA Connecticut Healthcare System, comments, "This is exciting new evidence that genetic and environmental factors may interact to produce specific and long-lasting modifications in brain circuits. Further, these modifications may shape the course of one's life in extremely important ways, including increasing the risk for major depressive disorder and perhaps suicide."

So if people in the future build a time machine, go back to 1991, and demethylate Kurt Cobain's DNA then suddenly we'll have more Nirvana albums. If you notice a change in the number of Nirvana albums you can attribute the change to time travelers.

By Randall Parker 2008 October 23 10:19 PM  Brain Depression
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Cherries Reduce Body Fat In Rats

Eat tart cherries to help keep off excess weight?

CHICAGO, IL, October 26 – New research continues to link tart cherries, one of today's hottest "Super Fruits," to lowering risk factors for heart disease. In addition to lowering cholesterol and reducing inflammation, the study being presented by University of Michigan researchers at next week's American Dietetic Association annual meeting, found that a cherry-enriched diet lowered body weight and fat – major risk factors for heart disease.

Maybe the inflammation reduction causes a change in signaling that reduces body weight.

In the study, at-risk, obese rats that were fed a cherry-enriched diet saw significant decreases in body weight and fat (especially the important "belly" fat with known risk for heart disease) while maintaining lean muscle mass. After twelve weeks, the cherry-fed rats had 14 percent lower body fat compared to the other rats who did not consume cherries (cherry-fed rats were approximately 54% body fat; rats eating the Western diet alone were 63% body fat). The researchers suggested cherry consumption could have an effect on important fat genes and genetic expression. According to the American Heart Association, being overweight or obese, in particular when the weight is concentrated in the middle, is a major risk factor for heart disease . Nearly two out of three Americans are overweight.

The animals were fed a "Western diet," characterized by high fat and moderate carbohydrate – in line with the typical American diet – with or without added whole tart cherry powder, as 1 percent of the diet. The study was funded by the Cherry Marketing Institute, which provided an unrestricted grant to the University of Michigan to conduct the research and was not directly involved in the design, conduct or analysis of the project.

Would blueberries or cranberries deliver the same benefit? Would this work in humans?

By Randall Parker 2008 October 23 10:14 PM  Brain Appetite
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Temperature Of Held Objects Influences Behavior

Free will is an illusion. Even a cup of coffee manipulates you in ways you can't tell. Even a cold or hot cup of coffee temporarily held in a person's hands can act like a puppeteer manipulating human emotions and behavior.

In the first study, Williams and John A. Bargh, a psychology professor at Yale University, found that holding a hot cup of coffee leads people to judge a stranger to be a warmer person, in terms of such traits as generosity and kindness, compared with a group of people who held a cup of iced coffee.

In a second study, they had people hold either a warm or cold object (therapeutic hot or cold pads), and then gave them a choice of reward for participating in the study: either a gift for a friend, or a reward for themselves.

"We found that people who held the hot pad were more likely to choose the gift for a friend, and people who held the cold pack were more likely to choose the reward for themselves," Williams said. "Both of these effects occurred without people's awareness of the possible effects of temperature."

Hand a friend something hot to hold before you ask for a favor.

"We found that people who held the hot pad were more likely to choose the gift for a friend, and people who held the cold pack were more likely to choose the reward for themselves," Williams said. "Both of these effects occurred without people's awareness of the possible effects of temperature."

People are incredibly sensitive to cues in their physical environments, Williams said. "The metaphorical relationship between physical temperatures and interpersonal warm or cold feelings is not haphazard or accidental, but reveals something interesting about the way the mind works, in that a cue from the physical domain can have such a meaningful impact on psychological outcomes," he said.

Never mind that old saying "cold hands, warm heart". The truth of the matter is "cold hands, cold heart".

In a similar study, Williams repeated the same experiment using not coffee, but hot and cold compress pads. To eliminate any inadvertent influence on the experiment by the confederate, the study subjects were asked to retrieve either a hot or cold pad and to evaluate it under the guise of a product test.

After rating the effectiveness of the pads, the study subjects were given a choice of reward for participating in the study: either a Snapple beverage or a $1 gift certificate to a local ice cream shop. In some cases the reward offer was framed as a gift to "treat a friend" and in others as a personal reward. Regardless of which gift was offered, those primed with coldness were more likely to choose a gift for themselves, while those primed with warmth were more likely to choose the gift for a friend.

"Experiences of physical temperature per se affect one's impressions of and pro-social behavior toward other people, without one's awareness of such influences," said Williams. "At a board meeting, for instance, being willing to reach out and touch another human being, to shake their hand, those experiences do matter although we may not always be aware of them. In a restaurant, it's been shown that wait staff who touch customers usually get a better tip. It's a nice gesture, but it also has a warming effect."

Williams said the research could have marketing implications because it shows just how strong the bond is between the physical and the psychological world.

"In a point-of-service or communications interaction, paying attention to the fact that customers are tied to the physical world in which buying behavior occurs is important," said Williams. "If you are running a promotion outdoors on a cold day, maybe giving away a warm cookie will help you make connections with consumers. It gives marketers and managers more tools to work with."

Scientists will find many more ways that environmental cues can alter human behavior.

By Randall Parker 2008 October 23 09:43 PM  Brain Economics
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Selective Memory Loss Possible With Protein In Mice

At least in mice overexpression of protein αCaMKII while recalling a memory causes the extinction of that memory.

Dr. Tsien's research team, in collaboration with scientists at East China Normal University in Shanghai, were able to eliminate new and old memories alike by over-expressing a protein critical to brain cell communication just as the memory was recalled, according to research featured on the cover of the Oct. 23 issue of Neuron.

Dr. Tsien had already created a mouse that couldn't form memories by eliminating the NMDA receptor, which receives messages from other neurons. He then garnered international acclaim by making "Doogie," a smart mouse in which a subunit of the NMDA receptor is over-expressed. Younger brains have higher amounts of this NR2B subunit which leaves communication channels between brain cells open longer. That is why young people can learn faster than older adults.

This time he was examining downstream cascades of the NMDA receptor to learn more about memory formation. An abundant protein found only in the brain, called αCaMKII, was a logical place to look because it's a major signaling molecule for the NMDA receptor. He found that when he over-expressed αCaMKII while a memory was being recalled, that single memory was eliminated.

While some might want to suppress traumatic haunting memories consider the mischief possible by suppressing memories. A government that no longer trusts a secret agent might want to suppress the memories of that agent before firing him. This brings to mind Tommy Lee Jones' character retiring to a post office without his memories. All those people in Men In Black who had their memories suppressed with a neuralizer might some day have real world equivalents.

By Randall Parker 2008 October 23 12:37 AM  Brain Memory
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Stem Cells Detect Cancer Signals And Stop Growth

Stem cells need to guard against going cancerous.

ANN ARBOR, Mich.---Like a sentry guarding the castle walls, a molecular messenger inside adult stem cells sounds the alarm when it senses hazards that could allow the invasion of an insidious enemy: Cancer.

The alarm bell halts the process of cell division in its tracks, preventing an error that could lead to runaway cell division and eventually, tumor formation.

"Our work suggests that to be able to prevent abnormal cell proliferation, which could lead to cancer, stem cells developed this self-checking system, what we're calling a checkpoint," said Yukiko Yamashita of the University of Michigan's Life Sciences Institute.

"And if it looks like the cell is going to divide in the wrong way, the checkpoint senses there's a problem and sends the signal: 'Don't divide! Don't divide!'" said Yamashita, a research assistant professor of life sciences and an assistant professor of cell and developmental biology at the U-M Medical School.

The mechanisms which the body has for protecting against cancers are problematic for the development of stem cell therapies. Our stem cells become less able to divide as they age. Research done in mice shows that blood in the aged contains compounds that suppress stem cells. Maybe some of the factors that stop the cell division mentioned above are coming from the blood or surrounding tissues. We need to understand in detail each of the mechanisms by which stem cells become less able to divide with age.

Stem cells can be genetically engineered to ignore some of the factors that suppress stem cell replication. But this approach seems problematic. Aging isn't the only cause of the body's production of compounds that suppress growth. Stem cells that ignore growth suppression signals might cause problems similar to those caused by cancers.

By Randall Parker 2008 October 23 12:31 AM  Biotech Stem Cells
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2008 October 21 Tuesday
Amphibian Losses Cut Ecosystem Productivity

Some wonder whether loss of species diversity has costs. Here's an example such a cost. The loss of frogs to the global spread of a killer fungus causes streams to produce less biomass.

Athens, Ga. – Streams that once sang with the croaks, chirps and ribbits of dozens of frog species have gone silent. They’re victims of a fungus that’s decimating amphibian populations worldwide.

Such catastrophic declines have been documented for more than a decade, but until recently scientists knew little about how the loss of frogs alters the larger ecosystem. A University of Georgia study that is the first to comprehensively examine an ecosystem before and after an amphibian population decline has found that tadpoles play a key role keeping the algae at the base of the food chain productive.

“Many things that live in the stream depend on algae as a base food resource,” said lead author Scott Connelly, a doctoral student who will graduate in December from the UGA Odum School of Ecology. “And we found that the system was more productive when the tadpoles were there.

The results, which appear in the early online edition of the journal Ecosystems, demonstrate how the grazing activities of tadpoles help keep a stream healthy. The researchers found that while the amount of algae in the stream was more than 250 percent greater after the amphibian population decline, the algae were less productive at turning sunlight and nutrients into food for other members of the ecosystem. Without tadpoles swimming along the streambed and stirring up the bottom, the amount of sediment in the stream increased by nearly 150 percent, blocking out sunlight that algae need to grow.

Which species losses due to human activity will cut into the amount of biomass produced by ecosystems? We are going to find out.

By Randall Parker 2008 October 21 09:32 PM  Trends Extinction
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Sexual Bonobos Kill Other Primates

The 1960s dream of "make love, not war" does not work for Bonobos. Even though bonobo societies are characterized by promiscuity and a lack of male dominance the males still hunt and kill other primate species.

Unlike the male-dominated societies of their chimpanzee relatives, bonobo society—in which females enjoy a higher social status than males—has a "make-love-not-war" kind of image. While chimpanzee males frequently band together to hunt and kill monkeys, the more peaceful bonobos were believed to restrict what meat they do eat to forest antelopes, squirrels, and rodents.

Not so, according to a study, reported in the October 14th issue of Current Biology, a Cell Press publication, that offers the first direct evidence of wild bonobos hunting and eating the young of other primate species.

Competition among primates is unavoidable since resources are limited. Short of genetic engineering I doubt that will change. Even without male dominance in bonobo societies they still go killing other primates.

"These findings are particularly relevant for the discussion about male dominance and bonding, aggression and hunting—a domain that was thought to separate chimpanzees and bonobos," said Gottfried Hohmann of the Max-Planck-Institute for Evolutionary Anthropology. "In chimpanzees, male-dominance is associated with physical violence, hunting, and meat consumption. By inference, the lack of male dominance and physical violence is often used to explain the relative absence of hunting and meat eating in bonobos. Our observations suggest that, in contrast to previous assumptions, these behaviors may persist in societies with different social relations."

Bonobos live only in the lowland forest south of the river Congo, and, along with chimpanzees, they are humans' closest relatives. Bonobos are perhaps best known for their promiscuity: sexual acts both within and between the sexes are a common means of greeting, resolving conflicts, or reconciling after conflicts.

The researchers made the discovery that these free-loving primates also hunt and kill other primates while they were studying a bonobo population living in LuiKotale, Salonga National Park, in the Democratic Republic of Congo. They had been observing the bonobos there for the last five years, which is what made the new observations possible.

By Randall Parker 2008 October 21 08:54 PM  Evolution Primates
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2008 October 20 Monday
High Fruit And Vegetable Diet Cuts Heart Risk 30%

The news is the same all around the world: Eat a lot more fruits and vegetables.

DALLAS, Oct. 21, 2008 — The typical Western diet — fried foods, salty snacks and meat — accounts for about 30 percent of heart attack risk across the world, according to a study of dietary patterns in 52 countries reported in Circulation: Journal of the American Heart Association.

Researchers identified three dietary patterns in the world:
• Oriental: higher intake of tofu, soy and other sauces;
• Prudent: higher intake of fruits and vegetables; and
• Western: higher intake of fried foods, salty snacks, eggs and meat.

The Prudent diet was associated with a lower heart attack risk than the Oriental, researchers said.

“The objective of this study was to understand the modifiable risk factors of heart attacks at a global level,” said Salim Yusuf, D.Phil., the study’s senior author.

Previous studies have reached similar conclusions about the Prudent and Western diet in the United States and Europe. This study broadens those findings and identifies a unique dietary pattern that researchers labeled “Oriental” (because of a higher content of food items typical of an Oriental diet.) The dietary pattern recommended by the American Heart Association is similar to the Prudent diet described in this study.

Eat more fruits and vegetables. Never mind that in other posts I delve into the concentrations of flavanols or pectin or other antioxidants in different fruits and vegetables. The main thing is to get more fruits and vegetables and less of everything else (with the possible exception of nuts and high omega 3 fish).

After adjusting for known risk factors, researchers found:
• People who consumed the Prudent diet of more fruits and vegetables had a 30 percent lower risk of heart attack compared to people who ate little or no fruits and vegetables.
• People who consumed the Western diet had a 35 percent greater risk of having a heart attack compared to people who consumed little or no fried foods and meat.
• The Oriental pattern showed no relationship with heart attack risk.

Researchers said that while some components of the Oriental pattern may be protective, others such as the higher sodium content of soy sauces, may increase cardiovascular risk, neutralizing any relationship.

You know what you need to do. But can you manage to make yourself do it? Most people who know better still do not act on the information. French fries and burgers just taste too good because your ancestors generally died of calorie malnutrition and its complications before getting a chance to die of a heart attack. So appetite-regulating genes were selected by natural selection to make us go for fats and meats and sweets.

By Randall Parker 2008 October 20 11:06 PM  Aging Diet Heart Studies
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Species With No Close Relatives Worst To Lose

We are in the early stages of a massive human-caused mass extinction. Some biologists at UC Santa Barbara ask an important question: since most of the threatened species can't be saved is there some way to identify which species are the worst to lose? Their answer: loss species with no evolutionary close relatives in their ecosystem will cause the biggest impact and most deserve saving.

(Santa Barbara, Calif.) –– The Earth is in the midst of the sixth mass extinction of both plants and animals, with nearly 50 percent of all species disappearing, scientists say.

Because of the current crisis, biologists at UC Santa Barbara are working day and night to determine which species must be saved. Their international study of grassland ecosystems, with flowering plants, is published this week in the Proceedings of the National Academy of Sciences.

"The current extinction event is due to human activity, paving the planet, creating pollution, many of the things that we are doing today," said co-author Bradley J. Cardinale, assistant professor of ecology, evolution and marine biology (EEMB) at UC Santa Barbara. "The Earth might well lose half of its species in our lifetime. We want to know which ones deserve the highest priority for conservation."

Think of this as development of rules for triage. Technology combined with the human instinct for reproduction is going to wipe out a large fraction of other species. For those few of us who believe that such species loss is a really bad thing what types of species conservation should we support? It is an important question.

Recent studies show that ecological systems with fewer species generally produce less biomass than those with more species. Less plant biomass means that less carbon dioxide is absorbed from the atmosphere and less oxygen is produced. So, as the biomass of plants plummets around the globe, the composition of gasses in the atmosphere that support life could be profoundly affected. Additionally, there are fewer plants for herbivorous animals to eat. Entire food chains can be disrupted, which can impact the production of crops and fisheries.

The loss of species that are not closely related to other species in the ecosystem reduces productivity more than the loss of species with close relatives. And the more genetically distinct a species is, the more impact it has on the amount of biomass in an ecosystem.

"Losing a very unique species may be worse than losing one with a close relative in the community," said Oakley. "The more evolutionary history that is represented in a plant community, the more productive it is."

Cadotte explained that the buttercup is a very unique species, evolutionarily. Losing the buttercup, where it occurs in grasslands, would have a much bigger impact on the system than losing a daisy or a sunflower, for example. The latter species are closely related. Each could therefore help fill the niche of the other, if one were to be lost. The daisy and sunflower also have a more similar genetic make-up.

"These 40 studies are showing the same thing for all plants around the world," said Cardinale. "It is not a willy-nilly conclusion. This study is very robust. It includes studies of plants that are found throughout the U.S., Europe, and Asia. We can have a high degree of confidence in the results. And the results show that genetic diversity predicts whether or not species matter."

Cheap DNA sequencing will tell us more about species relatedness. But even if we can find out which species are most important to save will we even be able to protect enough ecosystems to keep the important species around? I'm skeptical. 9 billion people are going to cause massive habitat destruction.

By Randall Parker 2008 October 20 10:36 PM  Trends Extinction
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Flavonols In Cocoa Powder And Other Foods

Scientifically and health minded chocolate and cocoa eaters take note. Processing of cocoa powder to make it less bitter removes substantial amounts of antioxidants.

Over the past ten years, dark chocolate and cocoa have become recognized through numerous studies for flavanol antioxidant benefits. In a study published this month in the Journal of Agricultural and Food Chemistry, scientists from The Hershey Company and Brunswick Laboratories of Norton, MA report on the levels of antioxidants in selected cocoa powders and the effect of processing on the antioxidant levels. The study, which analyzed Hershey's Natural Cocoa Powder and nineteen other cocoa powders, reported that natural cocoa powders have the highest levels of antioxidants. Natural cocoa powders contained an average of 34.6 mg of flavanols per gram of cocoa powder, or about 3.5% of total flavanols by weight. This places cocoa powder among the foods highest in these types of antioxidants.

The study went on to look at a variety of Dutched (alkaline processed) cocoa powders, which are commonly used by the food industry. New findings showed that the Dutched cocoa powders, especially the light- and medium-Dutched cocoa powders, retained significant amounts of cocoa flavanol antioxidants. In fact, despite the losses created by light to medium Dutch processing, these cocoa powders still were in the top 10% of flavanol-containing foods when results were compared to foods listed in the USDA Procyanidin Database.

This is why Mars sells their Cocoavia line of chocolates that have more retained antioxidants. But it is not clear to me how high the concentration of antioxidants is in Cocoavia versus lightly processed or even heavily processed cocoa powders.

When buying cocoa powders what we need to know is just how heavily processed they have been. The difference between 40% and 10% retention of flavanols is a factor of 4.

In this study, the degree of cocoa alkalization caused a progressive, but not complete loss, of flavanol antioxidants, with about 40% retained in lightly dutched cocoas, 25% retained in medium dutched cocoas, and 10% retained in heavily dutched cocoas.

That USDA Procyanidin Database makes for interesting reading (at least to me). Raw pinto beans are up there with unsweetened chocolate in terms of procyanidin antioxidants and you can eat a lot more pinto beans than chocolate. But cooked pinto beans have about 2 orders of magnitude less of the good stuff. Is that accurate? Blueberries and cranberries are excellent sources. Ditto hazelnuts, pecans, and pistachios. Sorghum is highly excellent. I had no idea. But that's typically cooked. Whereas you can eat the berries and nuts raw. My advice: eat the berries and nuts.

Update: Chocolate contains resveratrol.

In the study, top selling retail products from six categories were tested for the level of resveratrol and its sister compound, piceid. The six product categories included cocoa powder, baking chocolate, dark chocolate, semi-sweet baking chips, milk chocolate and chocolate syrup. Gram for gram, cocoa powder had the highest average amount of resveratrol and piceid, followed by baking chocolates, dark chocolates, semi-sweet chips, milk chocolate and then chocolate syrup. In the products studied, the level of piceid was 3 to 6 times the level of resveratrol.

When the cocoa and chocolate levels were compared to published values for a serving of red wine, roasted peanuts and peanut butter, resveratrol levels of cocoa powders, baking chocolates and dark chocolate all exceeded the levels for roasted peanuts and peanut butter per serving, but were less than California red wine.

My guess: If you want to get a regular substantial dose of resveratrol then best to take pills.

By Randall Parker 2008 October 20 08:27 PM  Aging Diet Resveratrol
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2008 October 19 Sunday
Low Antioxidants Create Eye Disease Risk

Get more antioxidants from food in order to slow your eye aging due to sun exposure.

A European study suggests that the combination of low plasma levels of antioxidants and blue light exposure from the sun is associated with certain forms of the eye disease age-related macular degeneration (AMD), according to a report in the October issue of Archives of Ophthalmology, one of the JAMA/Archives journals.

"The retina is vulnerable to the damaging effects of light," the authors write as background information in the article. "While wavelengths in the UV radiation range are largely absorbed by the cornea and lens, the retina is exposed to visible light, including blue light." Animal and laboratory studies suggest blue light may damage the retina and contribute to the development of AMD, which occurs when the area of the retina (macula) responsible for sharp vision deteriorates.

Antioxidant enzymes—including vitamins C and E, the carotenoids (lutein and zeaxanthin) and zinc—may protect against the harmful effects of blue light on the retina. Astrid E. Fletcher, Ph.D., of the London School of Hygiene & Tropical Medicine, and colleagues measured levels of these nutrients in the blood of 4,753 older adults (average age 73.2) who were part of the European Eye Study. Participants also were interviewed about their lifetime sunlight exposure and had photographs taken of their retinas to detect AMD.

Of the 4,400 participants with complete information available, 2,117 did not have AMD, 101 had neovascular (advanced, involving the formation of new blood vessels) AMD and 2,182 had early-stage AMD. Overall, there was no association between blue light exposure and neovascular or early AMD. However, blue light exposure was associated with neovascular AMD in the one-fourth of individuals with lowest antioxidant levels. "In particular, the combination of blue light exposure in the presence of low levels of zeaxanthin, alpha-tocopherol [vitamin E] and vitamin C was associated with a nearly four-fold odds ratio of neovascular AMD," the authors write.

The zeaxanthin comes from kale, collard greens, and other green leafy vegetables. Those same veggies are good sources of vitamin K which might slow brain aging due to myelin decay. Vegetables are good for you. But you already knew that. What would it take to get you to eat more vegetables?

By Randall Parker 2008 October 19 10:43 PM  Aging Diet Eye Studies
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Ovulation Raises Pitch Of Women's Voices

Women have higher pitched voices around ovulation.

A woman's voice tends to rise in pitch the closer she is to ovulation according to research published today in the Royal Society Journal Biology Letters. Researchers believe this is because a higher pitch is more attractive and more feminine, thus signalling fertility to potential partners.

Scientists at the University of California recorded the voices of 69 women to examine whether they raise their voice pitch during ovulation. Using hormone tests the women were recorded at two phases of their ovulatory cycle, once when fertility was low and once near ovulation. Results showed that the closer women were to ovulation, the more they raised their pitch.

Interestingly, this difference was apparent only when women spoke a simple introductory sentence such as 'hi, I'm a student at UCLA' - and not for simple vowel sounds. According to the researchers this shows that women change their voice in relation to fertility and possibly only in social communication contexts.

The findings follow other recent studies which have documented several detectable ovulatory cues in humans, including midcycle increases in body scent attractiveness, flirtation and attention to style of dress.

A 2006 report also finds that women are slaves to their hormones. Just like men.

Thirty-eight normally cycling women provided daily reports of sexual interests and feelings for 35 days. Near ovulation, both pair-bonded and single women reported feeling more physically attractive and having greater interest in attending social gatherings where they might meet men. Pair-bonded women who were near ovulation reported greater extra-pair flirtation and greater mate guarding by their primary partner. As predicted, however, these effects were exhibited primarily by women who perceived their partners to be low on hypothesized good genes indicators (low in sexual attractiveness relative to investment attractiveness). Ovulation-contingent increases in partner mate guarding were also moderated by female physical attractiveness; midcycle increases in mate guarding were experienced primarily by less attractive women, whereas more attractive women experienced relatively high levels of mate guarding throughout their cycle. These findings demonstrate ovulation-contingent shifts in desires and behaviors that are sensitive to varying fitness payoffs, and they provide support for the good genes hypothesis of human female extra-pair mating.

So guys, if you want a girlfriend who gets jealous over you then go for a less attractive woman.

What I want to know: Since the birth control pill prevents ovulation does it reduce the desire of women to dress up? Also, does it lower the average pitch of women's voices?

Once we gain the ability to manipulate the mental switches that cause mating behavior will women choose to put themselves perpetually in the mental state they normally feel just around ovulation? Or will they put themselves in other mental states less oriented toward mating? I'm wondering whether we'll still have lots of sexy dressing women 50 years from now.

By Randall Parker 2008 October 19 02:52 PM  Brain Sexuality
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2008 October 18 Saturday
Myelin And Finger Tapping Speed Peak At Age 39

Have you mentally peaked yet? If we could reverse the decay of neuron insulation in our brains we'd probably maintain fast coordination and better thinking ability for decades longer.

Reporting in the online version of the journal Neurobiology of Aging, Dr. George Bartzokis, professor of psychiatry at the UCLA Semel Institute for Neuroscience and Human Behavior at UCLA, and his colleagues compared how quickly a group of males ranging in age from 23 to 80 could perform a motor task and then correlated their performances to their brains' myelin integrity. The researchers found a striking correlation between the speed of the task and the integrity of myelination over the range of ages. Put another way, after middle age, we start to lose the battle to repair the myelin in our brain, and our motor and cognitive functions begin a long, slow downhill slide.

The myelination of brain circuits follows an inverted U-shaped trajectory, peaking in middle age. Bartzokis and others have long argued that brain aging may be primarily related to the process of myelin breakdown.

"Studies have shown us that as we age, myelin breakdown and repair is continually occurring over the brain's entire 'neural network,'" said Bartzokis, who is also a member of UCLA's Ahmanson–Lovelace Brain Mapping Center and the UCLA Laboratory of Neuro Imaging. "But in older age, we begin losing the repair battle. That means the average performance of the networks gradually declines with age at an accelerating rate."

As the years go by other things are going wrong in the brain as well. But just preventing demyelination would make a big difference.

Myelin is a phospholipid (fat) insulation layer around the axon sections of neurons. It speeds the transmission of electrical impulses down nerves.

Your finger tapping speed and myelin insulation both peak at about age 39. After that it is all downhill until the development of rejuvenation therapies that will remyelinate the brain.

In the study, each of the 72 participants had a magnetic resonance imaging (MRI) scan that measured the myelin integrity in the vulnerable wiring of their brain's frontal lobes. The maximum finger-tapping speed (the number of taps over a period of 10 seconds) was measured just before the MRI measure was obtained.

The results supported what the researcher had suspected, that finger-tapping speed and myelin integrity measurements were correlated and "had lifespan trajectories that were virtually indistinguishable," according to Bartzokis. And yes, they both peaked at 39 years of age and declined with an accelerating trajectory thereafter.

Bartzokis said these observations are consistent with the hypothesis that "maximum motor speeds depend upon high frequency AP bursts that, in turn, depend on the myelin integrity of the neural networks involved in the task."

"Beginning in middle age," he said, "the process of age-related myelin breakdown slowly erodes myelin's ability to support the very highest frequency AP bursts. That may well be why, besides achy joints and arthritis, even the fittest athletes retire and all older people move slower than they did when they were younger."

So what might a rejuvenating myelin repair therapy look like? In the brain we might need youthful oligodendrocyte glial cells that can replace old glial cells that can no longer do as much myelination. In the peripheral nervous system we'll need rejuvenated Schwann cells that serve a similar function.

Another approach might involve development of drugs or gene therapies that will regulate existing glial cells to turn on their myelination activity. Scientists are studying the genetic regulatory mechanisms of how myelination is controlled with research into genes like LINGO-1, connexin29 and connexin32, WAVE1, and the Quaking gene Qk1 among many others. The many scientists trying to figure out myelin formation and glial cell differentiation are doing valuable work that will help at least some of us avoid the cognitive decay characteristic of aging.

Several myelin-related degenerative disorders such as multiple sclerosis and leukodystrophy provide most of the impetus behind myelin research. In fact, myelination problems might underlie some childhood development disorders and addictive disorders. At this point the idea of manipulating glial cells to reverse general brain aging still seems too unorthodox in the mainstream. But fortunately the need to cure diseases that strike at younger ages provides a compelling rationale for developing therapies which will also help to reverse aging. However, if the desirability and attainability of the goal to reverse aging could become mainstream the amount of resources going into brain rejuvenation therapies would soar and we'd get useful treatments sooner.

By Randall Parker 2008 October 18 09:17 AM  Brain Aging
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2008 October 16 Thursday
Obese People Get Less Pleasure From Chocolate Milkshakes

Not only are fat people cursed with less physical attractiveness, greater health risks, and greater difficulty in getting around. Obese people get less pleasure out of eating food.

AUSTIN, Texas—Obese individuals may overeat because they experience less satisfaction from eating food due to a reduced response in their brains' reward circuitry, according to a new study by Eric Stice, psychology researcher at The University of Texas at Austin.

While eating, the body releases dopamine, a neurotransmitter in the reward centers of the brain, but Stice found obese people show less activation in the striatum relative to lean people. He also found individuals with a blunted response were more likely to show unhealthy weight gain, particularly if they had a gene associated with compromised dopamine signaling in the brain's reward circuitry.

Stice and a team of researchers have published their findings in the Science article, "Relation Between Obesity and Blunted Striatal Response to Food is Moderated by TaqIA A1 Allele."

A genetic variation that lowers the number of dopamine neurotransmitter receptors reduces one's ability to enjoy a chocolate milkshake. Nature is cruel. Some people have a handicapped ability to excite their brain's dorsal striatum.

Using Functional Magnetic Resonance Imaging (fMRI), Stice's team measured how the dorsal striatum was activated in response to the taste of a chocolate milkshake (versus a tasteless solution). The researchers also tested participants for the presence of a genetic variation linked to a lower number of dopamine D2 receptors, the Taq1A1 allele.

So if you are skinny you probably can better enjoy food than fat people can.

So the overweight aren't overweight because they've enjoyed food more. They are overweight because they need more stimulation to feel pleasure from food.

The results, drawn from two studies using functional magnetic resonance imaging (fMRI) at the University of Oregon's Lewis Center for Neuroimaging, appear in the Oct. 17 issue of the journal Science. The first-of-its-kind approach unveiled blunted activation in the brain's dorsal stratium when subjects were given milkshakes, which may reflect less-than-normal dopamine output.

"Although recent findings suggested that obese individuals may experience less pleasure when eating, and therefore eat more to compensate, this is the first prospective evidence for this relationship," said Eric Stice, lead author and senior researcher at the Oregon Research Institute (ORI) in Eugene. "The evidence of temporal precedence suggests it is a true vulnerability factor that predates obesity onset. In addition, the evidence that this relation is even stronger for individuals at genetic risk for compromised signaling in these brain regions points to an important biological factor that appears to increase risk for obesity onset."

Women are especially likely to gain weight if they have the genetic variation that reduces capacity for pleasure.

The researchers focused on a variant of the TaqlA1 gene, which is associated with increased body mass as well as a reduction of dopamine signaling in the dorsal striatum. The blunted response to tasty food was particularly pronounced in women with the variant. In addition, women with the variant were much more likely to gain weight after a year.

Prior work had shown that obese people tend to have fewer dopamine receptors in the brain and suggested that they overeat to compensate for this reward deficit. The current findings are consistent with the theory that the blunted response to food represents a vulnerability factor for obesity but it does not conclusively rule out the possibility that the finding reflects an adaptation to over-eating, Small cautioned.

How wide ranging is this genetically caused diminished capacity for pleasure? Does it reduce pleasure from most aspects of life?

Beware a hypofunctioning reward circuit.

Using Functional Magnetic Resonance Imaging (fMRI), Stice’s team measured the extent to which a certain area of the brain (the dorsal striatum) was activated in response to the individual’s receipt of a taste of chocolate milkshake (versus a tasteless solution). Participants in the studies were also tested for the presence of a genetic variation linked to a lower number of dopamine D2 receptors, the Taq1A1 allele. Researchers tracked participants’ changes in body mass index (BMI) over a 1-year follow up. Results showed that those participants with decreased striatal activation in response to milkshake receipt and those with the A1 allele were more likely to gain weight over time.

“These results suggest that individuals with hypofunctioning reward circuitry are at increased risk for unhealthy weight gain,” said Stice. “Thus, it is possible that behavioral or pharmacological interventions that correct this reward deficit may help prevent and treat obesity – an avenue we are currently pursuing in our research.”

This puts a whole new spin on the idea of "appetite for life". You'll be healthier if you can get more enjoyment from less experience.

Imagine a future treatment for obesity: Gene therapy or stem cell therapy that increases your concentration of dopamine D2 receptors in the dorsal striatum of the brain. Such a therapy would alter how a person experiences life.

By Randall Parker 2008 October 16 10:39 PM  Brain Appetite
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Faster Brain Aging In High Altitude Climbers?

Might want to give up that fantasy of climbing Everest or K2. Very high altitude climbers appear to lose some brain mass as a result of their hobby.

A study of professional mountain climbers has shown that high-altitude exposure can cause subtle white and grey matter changes to the area of the brain involved in motor activity, according to the October issue of the European Journal of Neurology.

Italian researchers took MRI scans of nine world-class mountain climbers, who had been climbing for at least 10 years, before and after expeditions to Mount Everest (8,848 metres) and K2 (8,611 metres) without an oxygen supply. They compared their MRI brain scans with 19 age and sex matched healthy control subjects.

Both the climbers and controls were carefully checked to exclude the presence of any major systemic, psychiatric or neurological illnesses. None of the control group subjects had any history of high-altitude exposure over 3,000 metres.

The results demonstrated that the climbers showed a reduction in both the density and volume of white matter in the left pyramidal tract, near the primary and supplementary motor cortex, when their baseline measurements were compared with the control group.

And when the researchers compared the before and after scans for the climbers, they also found a reduction in the density and volume of grey matter in the left angular gyrus.

There can be costs to pushing your body beyond its limits. Oxygen starvation during high altitude ascents might inflict a cost as lost brain cells.

Climbers need a portable energy source that could concentrate oxygen from the atmosphere. People familiar with Robert Freitas's proposed artificial red blood cells called respirocytes might expect these nanodevices to some day make a walk up Everest fairly easy. But a 4 hour oxygen storage capacity for respirocytes won't take you through even one day of the hike up.

But one of the potential benefits of nanomedical devices is their ability to extend natural human capabilities. Suppose you wanted to permanently maximize the oxygen-carrying capacity of your blood by infusing the largest possible number of respirocytes. The maximum safe augmentation dosage is probably about 1 liter of 50% respirocyte suspension, which puts 954 trillion devices into your bloodstream. You could then hold your breath for 3.8 hours, at the normal resting metabolic rate. At the maximum human metabolic rate, something like a continuous Olympic-class 50-meter dash exertion level, you could go for a full 12 minutes without taking a breath. Afterwards, your entire capacity is recharged by hyperventilating for just 8 minutes - then you're ready to go again.

Maybe a nanomaterial clothing could integrate with the respirocyte system so that most of your external surface area could be harnessed for oxygen collection. Nanotech will enable more extreme sports. Picture a group of people walking across the Hudson River on the bottom of the river. Or how about a group of people walking under the length of the Golden Gate Bridge on the bottom of the inlet to the bay? Combine respirocytes with an active system for pulling oxygen out of water and humans could do a lot of underwater hiking. Long life batteries would be needed for seeing though.

By Randall Parker 2008 October 16 09:45 PM  Aging Studies
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2008 October 15 Wednesday
Resveratrol Reduces Liver Fat Accumulation

The resveratrol in red wine might reduce the liver fat accumulation that can result from alcohol abuse.

BETHESDA, Md. (Oct. 14, 2008) − The accumulation of fat in the liver as a result of chronic alcohol consumption could be prevented by consuming resveratrol, according to a new study with mice. The research found that resveratrol reduced the amount of fat produced in the liver of mice fed alcohol and, at the same time, increased the rate at which fat within the liver is broken down.

Chronic alcohol consumption causes fat to accumulate and can lead to liver diseases, including cirrhosis and fibrosis of the liver. It can also result in liver failure. The study points to resveratrol as a possible treatment for alcoholic fatty liver disease, and as a way to prevent the disease in those who are at risk, but have not developed it.

Resveratrol is present in grapes, peanuts, berries and in red wine. Other research with mice has suggested resveratrol may have anti-cancer and anti-inflammatory properties. There is also evidence that it has cardiovascular benefits. However, these findings have not been extended to humans.

I'm still waiting for the definitive study on whether resveratrol will lower all-cause mortality. There's a decent chance it will. But at this point I'm still not sure whether resveratrol pills are worth taking.

By Randall Parker 2008 October 15 11:51 PM  Aging Diet Resveratrol
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Electric Wire Bypasses Peripheral Nerves To Control Muscles

Monkeys trained to stimulate neurons which have embedded electrodes could control wrist muscle contractions using a sort of primitive "fly-by-wire" system.

Researchers in a study funded by the National Institutes of Health (NIH) have demonstrated for the first time that a direct artificial connection from the brain to muscles can restore voluntary movement in monkeys whose arms have been temporarily anesthetized. The results may have promising implications for the quarter of a million Americans affected by spinal cord injuries and thousands of others with paralyzing neurological diseases, although clinical applications are years away.

This isn't just useful for people who have spinal cord injuries. Direct neural interfaces that can control one's own muscles could also control heavy equipment such as airplanes. Also, the ability to control one's own muscles via an artificial route that bypasses spinal nerve pathways could allow one to control one's extremities much more quickly. The wave of depolarization that transmits a pulse down a nerve's membranes is pretty slow compared to the speed of electrons in a wire.

"This study demonstrates a novel approach to restoring movement through neuroprosthetic devices, one that would link a person's brain to the activation of individual muscles in a paralyzed limb to produce natural control and movements," said Joseph Pancrazio, Ph.D., a program director at the National Institute of Neurological Disorders and Stroke (NINDS).

The research was conducted by Eberhard E. Fetz, Ph.D., professor of physiology and biophysics at the University of Washington in Seattle and an NINDS Javits awardee; Chet T. Moritz, Ph.D., a post-doctoral fellow funded by NINDS; and Steve I. Perlmutter, Ph.D., research associate professor. The results appear in the online Oct. 15 issue of Nature. The study was performed at the Washington National Primate Research Center, which is funded by NIH's National Center for Research Resources.

In the study, the researchers trained monkeys to control the activity of single nerve cells in the motor cortex, an area of the brain that controls voluntary movements. Neuronal activity was detected using a type of brain-computer interface. In this case, electrodes implanted in the motor cortex were connected via external circuitry to a computer. The neural activity led to movements of a cursor, as monkeys played a target practice game.

Of course, if electrodes get implanted into a person's muscles this creates the possibility of remote control of a person's muscles. A guy could get kidnapped and given secret surgery to implant a radio receiver and wiring to some of his peripheral muscles. The first time he finds out about what his kidnappers did is when he grabs a gun from a security agent and finds himself powerless to stop from shooting a top political leader. Other possibilities come to mind with husbands who get tired of hearing their wives gossip.

After each monkey mastered control of the cursor, the researchers temporarily paralyzed the monkey's wrist muscles using a local anesthetic to block nerve conduction. Next, the researchers converted the activity in the monkey's brain to electrical stimulation delivered to the paralyzed wrist muscles. The monkeys continued to play the target practice game—only now cursor movements were driven by actual wrist movements—demonstrating that they had regained the ability to control the otherwise paralyzed wrist.

Picture mini-electrodes in your brain tied to a transmitter. You could send messages to many devices in your environment including a garage door, a car ignition, or the thermostat in a house. I expect human-machine interfaces will become far more powerful in the future.

By Randall Parker 2008 October 15 11:41 PM  Cyborg Tech
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Cigarette Smoking Accelerates Aging By 10 Years

You already know that cigarettes are toxic cancer sticks and increase risks of a large number of diseases. Some smokers think their habit just increases their risk of dying from one disease or another and that perhaps they'll beat the odds. But smoking speeds the aging process and makes the whole body about an additional 10 years older after years of heaving smoking.

CHICAGO—Health-related quality of life appears to deteriorate as the number of cigarettes smoked per day increases, even in individuals who subsequently quit smoking, according to a report in the October 13 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

>Smoking has been shown to shorten men’s lives between seven and 10 years, according to background information in the article. It also has been linked to factors that may reduce quality of life, including poor nutrition and lower socioeconomic status.

Arto Y. Strandberg, M.D., of the University of Helsinki, and colleagues followed 1,658 white men born between 1919 and 1934 who were healthy at their first assessment, conducted in 1974. Participants were mailed follow-up questionnaires in 2000 that assessed their current smoking status, health and quality of life. Deaths were tracked through Finnish national registers.

During the 26-year follow-up period, 372 (22.4 percent) of the men died. Those who had never smoked lived an average of 10 years longer than heavy smokers (more than 20 cigarettes per day). Non-smokers also had the best scores on all health-related quality of life measures, especially those associated with physical functioning. Physical health deteriorated at an increasing rate as the number of cigarettes smoked per day increased, with heavy smokers experiencing a decline equivalent to 10 years of aging.

"Although many smokers had quit smoking between the baseline investigation in 1974 and the follow-up examination in 2000, the effect of baseline smoking status on mortality and the quality of life in old age remained strong," the authors write. "In all, the results presented here are troubling for those who were smoking more than 20 cigarettes daily 26 years earlier; in spite of the 68.9 percent cessation rate during follow-up, 44.1 percent of the originally heavy smokers had died, and those who survived to the mean [average] age of 73 years had a significantly lower physical health-related quality of life than never-smokers."

Smokers should not fool themselves. They are going down a faster slope into old age with weakening and infirmities hitting sooner.

By Randall Parker 2008 October 15 10:55 PM  Aging Studies
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2008 October 14 Tuesday
Even Moderate Alcohol Seems To Shrink Brain

Using 1,839 subjects in the Framingham Offspring Study examined with functional magnetic resonance imagining (fMRI) researchers find that even lower levels of alcohol drinking are associated with more rapid brain shrinkage with age.

Increasing alcohol intake was associated with loss in total brain volume greater than expected from age alone (P<0.001), reported Carol Ann Paul, of Wellesley College, and colleagues in the October issue of the Archives of Neurology.

In the cross-sectional study, women were affected more strongly than men by moderate alcohol intake averaging one to two drinks a day (eight to 14 per week).

Do you drink two drinks a day? If so, you are probably getting dumber faster than you need to.

The hope was that cardiovascular benefits of moderate alcohol consumption would keep the brain better fed with blood and slow brain aging. But that hope seems unrealistic now.

The cardiovascular benefits of low to moderate alcohol intake are thought to result from increasing blood flow rates, which would have been expected to benefit the brain also, Paul said.

But rather than preventing normal age-related volume reductions, the effects of moderate drinking were closer to those of heavy drinking, which has been linked to brain atrophy and cognitive decline, the researchers noted.

Your brain is shrinking anyway but alcohol makes it worse.

"Decline in brain volume -- estimated at 2 percent per decade -- is a natural part of aging," says Carol Ann Paul, who conducted the study when she was at the Boston University School of Public Health. She had hoped to find that alcohol might protect against such brain shrinkage.

"However, we did not find the protective effect," says Paul, who is now an instructor in the neuroscience program at Wellesley College. "In fact, any level of alcohol consumption resulted in a decline in brain volume."

Brain rejuvenation is going to be the hardest challenge in rejuvenation. Don't make it any worse by shrinking your brain any faster than unavoidable.

On the bright side, all the hours I spend every day searching for content for blog posts might be stimulating and exercising my brain. Web searching seems to stimulate the frontal, temporal and cingulate areas of your brain. So is all that web surfing really just a prudent anti-aging therapy? Does brain exercise slow brain aging?

For the study, the UCLA team worked with 24 neurologically normal research volunteers between the ages of 55 and 76. Half of the study participants had experience searching the Internet, while the other half had no experience. Age, educational level and gender were similar between the two groups.

Study participants performed Web searches and book-reading tasks while undergoing functional magnetic resonance imaging (fMRI) scans, which recorded the subtle brain-circuitry changes experienced during these activities. This type of scan tracks the intensity of cell responses in the brain by measuring the level of cerebral blood flow during cognitive tasks.

All study participants showed significant brain activity during the book-reading task, demonstrating use of the regions controlling language, reading, memory and visual abilities, which are located in the temporal, parietal, occipital and other areas of the brain.

Internet searches revealed a major difference between the two groups. While all participants demonstrated the same brain activity that was seen during the book-reading task, the Web-savvy group also registered activity in the frontal, temporal and cingulate areas of the brain, which control decision-making and complex reasoning.

"Our most striking finding was that Internet searching appears to engage a greater extent of neural circuitry that is not activated during reading — but only in those with prior Internet experience," said Small, who is also the director of UCLA's Memory and Aging Research Center.

In fact, researchers found that during Web searching, volunteers with prior experience registered a twofold increase in brain activation when compared with those with little Internet experience. The tiniest measurable unit of brain activity registered by the fMRI is called a voxel. Scientists discovered that during Internet searching, those with prior experience sparked 21,782 voxels, compared with only 8,646 voxels for those with less experience.

By Randall Parker 2008 October 14 11:20 PM  Brain Aging
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Pectin Binds To Protein Involved In Cancer Progression

Pectin, a carbohydrate found in many fruits and vegetables, might contribute to the anti-cancer effect of fruits and vegetables

Scientists have found a new possible explanation for why people who eat more fruit and vegetables may gain protection against the spread of cancers.

They have shown that a fragment released from pectin, found in all fruits and vegetables, binds to and is believed to inhibit galectin 3 (Gal3), a protein that plays a role in all stages of cancer progression.

"Most claims for the anticancer effects of foods are based on population studies," says Professor Vic Morris from the Institute of Food Research. "For this research we tested a molecular mechanism and showed that it is viable."

Population studies such as EPIC, the European Prospective Investigation of Cancer, identified a strong link between eating lots of fibre and a lower risk of cancers of the gastrointestinal tract. But exactly how fibre exerts a protective effect is unknown.

Pectin is better known for its jam-setting qualities and as being a component of dietary fibre. The present study supports a more exciting and subtle role.

Some readers ask me to write up the complete definitive scientific diet. I keep telling them that they already know what they ought to do but that they do not find the best diet appealing. Very few eat 10 servings of fruits and vegetables per day. Well, that's what you need to do. Just doing that will displace lots of junk out of your diet. But vegetables aren't much fun. Well, there's still fruits.

By Randall Parker 2008 October 14 12:21 AM  Aging Diet Cancer Studies
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2008 October 13 Monday
Low Vitamin D Link With Parkinson's Disease

Hey, been too long since I told you all to try to get more vitamin D in your diet. Here's another reason: People with Parkinson's Disease have lower blood vitamin D.

A majority of Parkinson's disease patients had insufficient levels of vitamin D in a new study from Emory University School of Medicine.

The fraction of Parkinson's patients with vitamin D insufficiency, 55 percent, was significantly more than patients with Alzheimer's disease (41 percent) or healthy elderly people (36 percent).

The results are published in the October issue of Archives of Neurology.

The finding adds to evidence that low vitamin D is associated with Parkinson's, says first author Marian Evatt, MD, assistant professor of neurology at Emory.

Evatt is assistant director of the Movement Disorders Program at Wesley Woods Hospital. The senior author is endocrinologist Vin Tangpricha, MD, assistant professor of medicine at Emory and director of the Endocrine Clinical Research Unit.

Evatt says her team compared Parkinson's patients to Alzheimer's patients because they wanted to evaluate the possibility that neurodegenerative diseases in general lead to vitamin D insufficiency.

One could argue that Parkinson's sufferers are less likely to get outside than the normal healthy. But look at the difference as compared to Alzheimer's sufferers. Granted this result does not prove a direction for cause and effect. But it is suggestive.

The other thing noteworthy about this result is that even in the US Southeast, a warmer climate, 36% of the healthy elderly lack sufficient vitamin D.

She says her team saw their results as striking because their study group came from the Southeast, not a region with long gloomy winters, where vitamin D insufficiency is thought to be more of a problem.

In addition, the study found that the fraction of patients with the lowest levels of vitamin D, described as vitamin D deficiency, was higher (23 percent) in the Parkinson's group than the Alzheimer's group (16 percent) or the healthy group (10 percent).

By Randall Parker 2008 October 13 11:53 PM  Aging Diet Brain Studies
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Chimp Numbers In Ivory Coast Fall Another Order Of Magnitude

Looks like chimp numbers in Côte d'Ivoire (Ivory Coast - and why not call it that?) have dropped two orders of magnitude since the 1960s.

In a population survey of West African chimpanzees living in Côte d'Ivoire, researchers estimate that this endangered subspecies has dropped in numbers by a whopping 90 percent since the last survey was conducted 18 years ago. The few remaining chimpanzees are now highly fragmented, with only one viable population living in Taï National Park, according to a report in the October 14th issue of Current Biology, a Cell Press publication.

Maybe in 50 years the human population of Africa will stop growing. Then again, maybe not. But long before that happens lots of primate species, cat species, and other species in Africa are going to be toast. Time to start doing massive DNA sample collection so that perhaps a couple of centuries from now these species can be reintroduced into the wild.

This alarming decline in a country that had been considered one of the final strongholds for West African chimps suggests that their status should be raised to critically endangered, said Geneviève Campbell of the Max Planck Institute for Evolutionary Anthropology.

The booming human population in Côte d'Ivoire is probably responsible for the chimpanzees' demise.

"The human population in Cote d'Ivoire has increased nearly 50 percent over the last 18 years," said Christophe Boesch, also of the Max Planck Institute for Evolutionary Anthropology. "Since most threats to chimpanzee populations are derived from human activities such as hunting and deforestation, this has contributed to the dramatic decline in chimpanzee populations. Furthermore, the situation has deteriorated even more with the start of the civil war in 2002, since all surveillance ceased in the protected areas."

Back in the late 80s the chimps in Ivory Coast were half the remaining chimps. Maybe they still are if the chimps in the rest of Africa are fairing just as poorly.

In the 1960s, the population of chimpanzees in Côte d'Ivoire was estimated at about 100,000 individuals. At the end of the 1980s, when the first and last nationwide chimpanzee survey was carried out, the total population of chimpanzees was estimated at 8,000 to 12,000 individuals. While that already represented a drastic decrease from the expected numbers, it nonetheless meant that Côte d'Ivoire harbored about half of the world's remaining West African chimpanzee populations.

In the new study, Campbell and Boesch's team conducted another nationwide survey, revealing a 90 percent drop in the chimpanzee nest encounter rate since the time of the last survey. That catastrophic decline in chimpanzees is especially strong in forest areas with low protection status, where the researchers saw no sign of the chimps. Even in protected areas like Marahoué National Park, chimpanzees have clearly suffered since surveillance and external funding support were disrupted by civil unrest in 2002.

Ivory Coast women are producing more than 4 babies per woman. While it has a population of 20.1 million today you can pay a visit to the US Census Bureau's web site's international database and do a query for population projections for 2050 and find that they expect a population of over 37 million. Even with the current population there's probably enough people in Ivory Coast to wipe out all the chimps. I doubt the chimps stand a chance with 37 million. So bye bye wild chimps. You can visit them in some zoos.

To my commenters who do not believe massive species extinctions are in store: Where are those chimps hiding?

By Randall Parker 2008 October 13 10:45 PM  Trends Extinction
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2008 October 12 Sunday
Scientist Sees Resource Constrained Future

Robert Criss says the big problem is exponential population growth.

Oct. 7, 2008 -- It's a 500-pound gorilla that Robert Criss, Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, sees standing on the speaker's dais at political rallies, debates and campaigns. Its name is population growth.

"Population growth is driving all of our resource problems, including water and energy. The three are intertwined," Criss says. "The United States has over 305 million people of the 6.7 billion on the planet. We are dividing a finite resource pie among a growing number of people on Earth. We cannot expect to sustain exponential population growth matched by increased per capita use of water and energy. It's troubling. But politicians and religious leaders totally ignore the topic."

Some argue that since disaster was predicted in the past and did not happen that pessimistic views of resource depletion should be dismissed. I'm reminded of the boy that cried wolf. The wolf eventually came.

A substantial portion of the American population are using non-renewable sources of ground water.

The United States is experiencing rapid population growth — at a rate higher than almost any other developed country — along with increased food production, Criss says. In many areas, especially the West, the practice of "mining" ground water to irrigate arid or semiarid land, which won't work in the long run, is becoming commonplace. "Energy and water use are intimately related," he says. "As water tables decline, you have to use more energy to lift the water out of the ground. That's what a pump has to do in places like Arizona where water levels have dropped many hundreds of feet. More people, more water use, more food, more energy. It's not sustainable."

Criss says approximately 150 million Americans use ground water, most of which is nonrenewable.

Market pricing of water can keep demand and supply in balance. But as water tables decline in Arizona will the price of water get so high as to make people migrate out of the state?

Some people do not see a resource-constrained future. They point to the big decline in oil prices as a sign that oil shortages are a thing of the past. But they aren't looking closely at the cause of the declining oil prices: US oil imports fell almost 10% in a single month. Fast and big dips in demand will lower prices.

The monthly trade report contains data on the price of imported oil. Friday's report said the average price per barrel in August fell to $119.99 from $124.66. Even with a price drop, U.S. crude import volumes eased to 308.38 million barrels from 342.02 million, amid a faltering economy.

Recessions and financial crises aren't what I want to count on to lower oil prices.

If we are headed into a economic Depression (and I have no idea) then oil demand will drop far enough that lower prices can be sustained for a while. But if we are (hopefully) not headed into a Depression then I would expect this oil price dip to be temporary. Economic growth in Asia will eventually boost Asian demand by more than enough to displace lost US demand. If one wants to be optimistic about future oil supplies one either has to point to large discoveries (and by large I mean each year discovering more than we used that year) or signs of a rapid scaling up of oil replacements.

Nanotechnology will eventually change the resource scarcity picture. In particular, energy limitations are solvable in the longer term. With nanotech assemblers photovoltaics will some day be very cheap and wind will become cheaper as well. With a lot of energy lots of materials become substitutable for each other. But I'm not expecting that sort of drop in fabrication costs in the next 10 years.

By Randall Parker 2008 October 12 06:08 PM  Trends Resource Depletion
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2008 October 10 Friday
Humans Evolved Egalitarianism In Pleistocene Era

The Pleistocene era that ended 10000 years ago saw the development of human societies less hierarchical than other ape societies. How did this happen? A mathematical model of human social structures suggests that the development of egalitarian human societies came about in a small number of generations.

Although anthropologists and evolutionary biologists are still debating this question, a new study, published in the open-access journal PLoS ONE, supports the view that the first egalitarian societies may have appeared tens of thousands of years before the French Revolution, Marx, and Lenin. These societies emerged rapidly through intense power struggle and their origin had dramatic implications for humanity. In many mammals living in groups, including hyenas, meerkats, and dolphins, group members form coalitions and alliances that allow them to increase their dominance status and their access to mates and other resources. Alliances are especially common in great apes, some of whom have very intense social life, where they are constantly engaged in a political maneuvering as vividly described in Frans de Waal's "Chimpanzee politics".

In spite of this, the great apes' societies are very hierarchical with each animal occupying a particular place in the existing dominance hierarchy. A major function of coalitions in apes is to maintain or change the dominance ranking. When an alpha male is well established, he usually can intimidate any hostile coalition or the entire community.

Note that humans still place great importance in status and power. A substantial portion of human behavior is aimed at achieving and demonstrating higher status. The human shift toward a more egalitarian model has been only partial. We still have plenty of genetic influences on our brains that make us desire higher status and power. Possibly human populations differ in their frequencies of alleles for egalitarian preferences versus hierarchical tendencies based on different selective pressures in different parts of the world.

In sharp contrast, most known hunter-gatherer societies are egalitarian. Their weak leaders merely assist a consensus-seeking process when the group needs to make decisions, but otherwise all main political actors behave as equal. Some anthropologists argue that in egalitarian societies the pyramid of power is turned upside down with potential subordinates being able to express dominance over potential alpha-individuals by creating large, group-wide political alliance.

What were the reasons for such a drastic change in the group's social organization during the origin of our own "uniquely unique" species? Some evolutionary biologists theorize that at some point in the Pleistocene, humans reached a level of ecological dominance that dramatically transformed the natural selection landscape. Instead of traditional "hostile forces of nature", the competitive interactions among members of the same group became the most dominant evolutionary factor. According to this still controversial view, known as the "social brain" or "Machiavellian intelligence" hypothesis, more intelligent individuals were able to take advantage of other members of their group, achieve higher social status, and leave more offspring who inherited their parent's genes for larger brain size and intelligence. As a result of this runaway process, the average brain size and intelligence were increasing across the whole human lineage.

I like this "Machiavellian intelligence" hypothesis. But we also evolved higher intelligence in order to better manipulate tools and our physical environment. Our spatial reasoning was probably not selected for in order to better engage in Machiavellian intrigue.

As people became smarter they became more able to form alliances against dominant alpha males. So intelligence increased the bargaining power of betas? Did the rise in human intelligence then cause a selection for personality traits characteristic of betas?

Also increasing were the abilities to keep track of within-group social interactions, to remember friends and their allies and enemies, and to attract and use allies. At some point, physically weaker members of the group started forming successful and stable large coalitions against strong individuals who otherwise would achieve alpha-status and usurp the majority of the crucial resources. Eventually, an egalitarian society was established. Although some of its components are well supported by data, this scenario remains highly controversial. One reason is its complexity which makes it difficult to interpret the data and to intuit the consequences of interactions between multiple evolutionary, ecological, behavioral, and social factors acting simultaneously. It is also tricky to evaluate relevant time-scales and figure out possible evolutionary dynamics.

A paper published in PLoS ONE today makes steps towards answering these challenges. The paper is co-authored by Sergey Gavrilets, a theoretical evolutionary biologist, and two computer scientists, Edgar Duenez-Guzman and Michael Vose, all from the University of Tennessee, Knoxville.

They developed a computer model to reach their conclusions. Keep in mind that two different computer models might produce the same result (greater sharing of resources in alliances) with different assumptions and mechanisms. We can't tell whether ideas in the minds of Pleistocene humans or genes that coded for alliance-oriented behavior were the bigger driving forces. One can easily imagine these two influences feeding on each other though.

Ideas in the head of one "cave man" (or should I say "savannah man"?) could have caused that guy to look at all the other people in his group and seek out those whose personalities were most amenable to alliance formation. Any genetic alleles that favored alliances could have been there for other reasons but the thoughts in one mind could have caused one guy to reach out to those with compatible genetic alleles and get them all to behave in ways (e.g. fighting as a group and splitting spoils evenly) that promoted the spread of those alleles.

To develop egalitarian societies larger scale conflicts are needed. This puts a much more positive spin on war, doesn't it? Having external enemies to focus on helps keep alliances together.

The model also highlights the importance of the presence of outsiders (or "scapegoats") for stability of small alliances. The researchers suggest that the establishment of a stable group-wide egalitarian alliance should create conditions promoting the origin of conscience, moralistic aggression, altruism, and other cultural norms favoring group interests over those of individuals. Increasing within-group cohesion should also promote the group efficiency in between-group conflicts and intensify cultural group selection.

A better organized group is going to wipe out less organized groups. Once group-level organization gets a foothold any genetic variants that helped favor it would get selected for and spread. Higher intelligence might have catalyzed the spread of alleles for higher intelligence and alleles for greater egalitarian behavior.

Is communism not possible because the spread of egalitarian alleles hasn't gone far enough? Too many of the old hierarchical alleles are still around? I suspect another explanation: The egalitarian alleles were selected for to enable groups to compete with other groups. Humans competed for resources and for the vast bulk of human history resource limitations made hunger widespread and the competition for resources fierce. Egalitarianism and competitive urges are key elements of human nature and egalitarianism's development came about to help people compete more effectively.

See also Cochran And Harpending See Human Evolution Acceleration and Cochran And Hawks Detect Human Evolution Acceleration.

By Randall Parker 2008 October 10 12:15 PM  Evolution Human Nature
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2008 October 09 Thursday
Risk Appetite Measurable With Brain Scans

Imagine employers scanning people's brains to choose more or less risk averse depending on job needs. Functional magnetic resonance imaging allows identification of more and less risk tolerant people.

That familiar pull between the promise of victory and the dread of defeat – whether in money, love or sport – is rooted in the brain's architecture, according to a new imaging study.

Neuroscientists at the USC Brain and Creativity Institute have identified distinct brain regions with competing responses to risk.

Both regions are located in the prefrontal cortex, an area behind the forehead involved in analysis and planning.

By giving volunteers a task that measures risk tolerance and observing their reactions with functional magnetic resonance imaging (fMRI), the researchers found that activity in one region identified risk-averse volunteers, while activity in a different region was greater in those with an appetite for risk.

The study appeared online Oct. 8 in the journal Cerebral Cortex.

"We can see risk as a battle between two forces," said Antoine Bechara, professor of psychology at USC. "There is always a lure of reward. There's always a fear of failure. These are the two forces that are always battling each other."

What will be even more interesting: A way to dial one's risk aversion up or down. Of course, if someone dialed their own risk enjoyment way way down they'd probably keep it low due to the risk aversion that would accompany the low setting on the knob. Some types of brain engineering will cause people to strongly prefer some states of mind. So brain engineering will tend to push populations toward the personality types that will most resist change.

By Randall Parker 2008 October 09 11:30 PM  Brain Economics
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2008 October 08 Wednesday
Nearly Quarter Of Mammals Threatened With Extinction

This looks like a sign of human over population to me.

Barcelona, Spain, 6 October, 2008 (IUCN) – The most comprehensive assessment of the world’s mammals has confirmed an extinction crisis, with almost one in four at risk of disappearing forever, according to The IUCN Red List of Threatened Species™, revealed at the IUCN World Conservation Congress in Barcelona.

Some claim to believe that every additional human life is an asset to us all. But if all the people in countries with rapidly growing populations had fewer babies I think we'd be better off.

I expect this problem to get worse because the human population looks set to increase by at least a couple billion more people.

The new study to assess the world’s mammals shows at least 1,141 of the 5,487 mammals on Earth are known to be threatened with extinction. At least 76 mammals have become extinct since 1500. But the results also show conservation can bring species back from the brink of extinction, with five percent of currently threatened mammals showing signs of recovery in the wild.

“Within our lifetime hundreds of species could be lost as a result of our own actions, a frightening sign of what is happening to the ecosystems where they live,” says Julia Marton-Lefèvre, IUCN Director General. “We must now set clear targets for the future to reverse this trend to ensure that our enduring legacy is not to wipe out many of our closest relatives.”

The real situation could be much worse as 836 mammals are listed as Data Deficient. With better information more species may well prove to be in danger of extinction.

“The reality is that the number of threatened mammals could be as high as 36 percent,” says Jan Schipper, of Conservation International and lead author in a forthcoming article in Science. “This indicates that conservation action backed by research is a clear priority for the future, not only to improve the data so that we can evaluate threats to these poorly known species, but to investigate means to recover threatened species and populations.”

Asian industrialization adds to the demand for timber and food crops. This results in more habitat loss. World demand growth for energy pulls more land into biomass crop production and further reduces habitat for wild animals. Plus, population growth pushes humans into more areas which previously were wild. The human footprint has become too large.

Less visibly, the oceans were once far more full of fish and other marine creatures. Now they show more signs of plastic waste and fewer signs of fish. While privately owned fisheries might help some for the oceans I do not see how private ownership of land is going to save many land species.

By Randall Parker 2008 October 08 11:08 PM  Trends Extinction
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2008 October 07 Tuesday
Oleic Acid Decreases Appetite In Rats

Over half of olive oil is a fatty acid called oleic acid, which at least in rats boosts production of a hormone that decreases hunger.

A fatty acid found in abundance in olive oil and other "healthy" unsaturated fats has yet another benefit: it helps keep the body satisfied to prolong the time between meals.

A new study in the October Cell Metabolism, a publication of Cell Press, reveals that once this type of fat, known as oleic acid, reaches the intestine, it is converted into a lipid hormone (oleoylethanolamide, or OEA) that wards off the next round of hunger pangs. The researchers said it may be the first description of an ingredient in food that directly provides the raw materials for a hormone's production.

The findings in rats may yield insight into the precise dietary makeup of fat and protein for optimal hunger control, the researchers said. (Protein plays in important role in limiting hunger as well, but by different means.) The newly discovered signaling pathway might also be tapped into with drugs designed to control appetite by supplementing OEA levels or blocking its breakdown. Similarly, in conditions where people don't eat enough, the researchers speculate that treatments targeting this system might improve the appetite.

Importantly, diets high in processed foods that are riddled with saturated fats might throw a wrench into this system of metabolic control, the researchers said.

Olive oil also contains phenolic compounds which are suspected of providing additional health benefits.

By Randall Parker 2008 October 07 11:50 PM  Brain Appetite
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Narcissists Natural Leaders?

People are willing to take orders from the self-absorbed.

COLUMBUS, Ohio – When a group is without a leader, you can often count on a narcissist to take charge, a new study suggests.

Researchers found that people who score high in narcissism tend to take control of leaderless groups. Narcissism is a trait in which people are self-centered, exaggerate their talents and abilities, and lack empathy for others.

“Not only did narcissists rate themselves as leaders, which you would expect, but other group members also saw them as the people who really run the group,” said Amy Brunell, lead author of the study and assistant professor of psychology at Ohio State University at Newark.

What I wonder: Did narcissism evolve as a leadership trait? Do groups do better with a leader? Therefore did genes for narcissism get selected for to occur at low frequency so that groups will have some but not too many leaders?

Narcissists with a desire for power were more likely to become leaders of groups.

The first study involved 432 undergraduate students. They all completed assessments which measured various personality traits, including narcissism. They were then put in groups of four, and told to assume they were a committee of senior officers of the student union, and their task was to elect next year’s director. Each person in a group was given a profile of a different candidate for the position, and each was to argue for their particular candidate.

Following the discussion, they voted on the director, and then completed a questionnaire evaluating the leadership of themselves and the other group members.

Results showed that students who scored higher on one dimension of narcissism – the desire for power - were more likely to say they wanted to lead the group, were more likely to say they did lead the group discussion, and were more likely to be viewed as leaders by the other group members.

The other dimension of narcissism – the desire for attention – was not as strongly related to leadership roles in the groups.

So will future parents choose to give their offspring genes that code for desire for power and narcissism? Will future generations compete harder for leadership positions?

But do narcissists really make better leaders? Student groups were asked to imagine themselves shipwrecked on an uninhabited island with the ability to choose among items needed for survival. The groups led by narcissists did not make any better decisions.

This study went further, though, by seeing how well the narcissists performed as leaders. Researchers looked at the lists, prepared by each individual and group, of the 15 items that they thought would help them survive. They compared their lists to one prepared by an expert who has taught survival skills to the U.S military.

Results showed that narcissists did no better than others on selecting the items that would best help them survive. In addition, groups that overall scored highest on narcissism did no better than other groups on the task.

We need ways to select reluctant but talented people for leadership positions.

Update: My question: Are members of the US Congress, the British and Australian Parliaments, and other major elected figures more or less narcissistic on average than CEOs of large corporations? Does selection for business leaders do a better job of filtering out narcissists than elections do?

By Randall Parker 2008 October 07 11:40 PM  Brain Society
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2008 October 06 Monday
$5000 Complete Gene Sequencing In 2Q 2009

Our biotechnological future is coming even faster than I expected. A Mountain View California biotech start-up, Complete Genomics, operating in stealth mode since a 2006 founding, has announced availability of personal complete DNA sequencing for $5000 in 2Q 2009. If they pull this off it is an amazing achievement.

The cost of determining a person’s complete genetic blueprint is about to plummet again — to $5,000.

That is the price that a start-up company called Complete Genomics says it will start charging next year for determining the sequence of the genetic code that makes up the DNA in one set of human chromosomes. The company is set to announce its plans on Monday.

Cheap! Starting to feel tempted yet?

Some scientists associated with this start-up are heavy hitters.

"I have great confidence that it's right," said Lawrence Berkeley National Lab geneticist Michael Eisen. "I don't know exactly what the underlying method is, but George Church isn't a kidder."

George Church is a Harvard University geneticist who helped found the Human Genome Project and was responsible for the first commercial genome sequence. He's also an adviser to the Mountain View, California-based Complete Genomics, provider of the $5,000 genome — and joining Church is Illumina co-founder Mark Chee, Institute for Systems Biology president Leroy Hood and Massachusetts Institute of Technology bioengineer Douglas Lauffenburger

But Complete Genomics is going to start out aiming at institutional customers. You might have to wait for individual customer access.

Based in Mountain View, Calif., Complete Genomics has raised $46 million in three rounds of financing since its incorporation in 2006. Unlike its commercial next-gen sequencing rivals – Roche/454, Illumina, Applied Biosystems (ABI) and Helicos – Complete Genomics will not be selling individual instruments, but rather offer a service aimed initially at big pharma and major genome institutes.

Complete Genomics is building what Reid calls “the world’s largest complete human genome sequencing center so we can sequence thousands of complete human genomes, so that researchers can conduct clinical trial-sized studies.” If all goes according to plan, that 32,000-square-feet facility will deliver 1,000 human genomes in 2009 and an eye-popping 20,000 genomes in 2010.

At $5000 per genome I think they'll easily sell out their capacity for the first 1000 genomes in 2009.

With materials costs of only $1000 per genome they think they'll sequence 1 million genomes in the next 5 years.

The company also said it intends to open additional genome sequencing centers across the U.S. and abroad. Over the next five years, the company projects that 10 such centers will be able to sequence 1 million complete human genomes.

Our problem becomes how to make sense of all this DNA sequencing data? That data needs to be matched with lots of physical measurements, medical histories, psychometric tests, exercise tests, and other data gathering to allow correlation of all the DNA sequencing differences with various human characteristics.

The approach uses DNA nanoballs. These things are called concatamers which probably refers to concatenation.

The first step is to prepare a gridded array of up to a billion DNA nanoballs, or DNBs. These DNBs are concatamers of 80-basepair (bp) mate-paired fragments of genomic DNA, punctuated with synthetic DNA adapters. The 80-bp fragments are derived from a pair of roughly 40-bp fragments that reside a known distance apart (say 500 bases or 10,000 bases). “We insert an adapter to break the 40 bases into 20 bases or 25 bases,” which acts like “a zip code or address into the DNA,” says Drmanac.

The sample preparation amplifies the DNA templates in solution rather than an emulsion or on a platform. It produces about 10 billion DNBs – each about 290 nm in diameter – in just 1 ml solution. “We spent lots of energy to make them small and sticky to the surface,” says Drmanac. The DNBs are spread onto a surface gridded with 300-nm diameter wells (prepared using photolithography) spaced just 1 micron apart. The DNBs settle into the wells like so many balls dropping into the pockets of a roulette wheel.

One promising use of cheap DNA sequencing data is in the study of cancer cells. Sequencing of tens of thousands or even hundreds of thousands of cancers will lead to much better identification of how DNA mutations contribute to cancer development.

So how cheap would DNA sequencing have to get before you'd pony up to get yourself sequenced? Once the price gets down to a few thousand dollars I'll be waiting more for useful information the sequencing data can provide than for a further price reduction. We are going to have to wait a few more years before we know enough about genetic differences for personal sequencing to provide useful information to most of us.

By Randall Parker 2008 October 06 10:16 PM  Biotech Advance Rates
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2008 October 05 Sunday
Thin Rollable Photovoltaics Developed

Imagine installing photovoltaics almost as easily as carpet.

Researchers led by John Rogers, a professor of materials science and engineering at the University of Illinois in Urbana-Champagne, used a combination of etching and transfer printing to create arrays of silicon cells that are one-tenth the thickness of conventional cells. They demonstrated multiple possible designs for solar panels incorporating the microcells, including dense arrays flexible enough to bend around a pencil. "You could roll them up like a carpet, transport them in a van, and unfurl them onto a rooftop," Rogers says.

The thinness ought to lower costs as compared to conventional silicon photovoltaics (PV).

A thin layer on architectural glass is lightweight enough to allow vertical installation.

"We can make it thin enough that we can put it on plastic to make a rollable system. You can make it gray in the form of a film that could be added to architectural glass," said John Rogers of the University of Illinois at Urbana-Champaign, who led the research.

"It opens up spaces on the fronts of buildings as opportunities for solar energy," Rogers said in a telephone interview.

After waiting for decades for PV to become cost efficient and flexible to use I think the 2010s will be when PV finally takes off on a massive scale and becomes ubiquitous.

By Randall Parker 2008 October 05 10:56 PM  Energy Solar
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Offshore Wind Developments For Rhode Island And New Jersey

In the wake of a decision for a Delaware offshore wind farm two more wind farm projects in the US Northeast reach initial agreements for their development. 15% of Rhode Island electric power will come from an offshore wind project.

Governor Donald L. Carcieri today announced that Deepwater Wind was chosen as the successful developer to construct a wind energy project off the shores of Rhode Island that will provide 1.3 million megawatt hours per year of renewable energy – 15 percent of all electricity used in the state. It is expected that the project will cost in excess of $1 billion to construct – all from private investment sources. A team of experts assembled by Governor Carcieri spent several months evaluating the detailed proposals submitted by seven development groups.

Deepwater Wind was established to develop utility-scale offshore wind projects in the northeastern part of the United States. The company’s major investors are FirstWind, a major developer of on-shore wind projects in the United States, D.E. Shaw & Co., a capital investment firm with deep experience in the energy sector, and Ospraie Management, a leading asset management firm with a focus on alternative energy markets.

The supporters of this project expect the wind electric costs to be not greatly above other sources.

Deepwater and the state are now set to enter into a 90-day negotiation period, during which details of the agreement for the wind farm will be hammered out. Andrew C. Dzykewicz, the governor’s chief energy adviser and the commissioner of the R.I. Office of Energy Resources, said he expects the Deepwater wind farm to be generating electricity at a cost of 7 to 9 cents per kilowatt-hour by 2012 if the regulatory process stays on track. (National Grid’s current rate base calls for a 12.5-cent rate.)

The deal is driven by a state law requiring more energy from renewables. Many states have passed such mandates.

Deepwater is proposing to build about 100 turbines, which could provide 385 megawatts of electricity – meeting Carcieri’s goal of obtain 15 percent of the state’s electricity energy from renewable sources. A state law mandates that the state must be getting 16 percent of its energy from renewables by 2019.

The NJ utility regulatory agency has chosen a team to develop another offshore wind farm.

The New Jersey Board of Public Utilities (NJ BPU) today announced that it has chosen Garden State Offshore Energy (GSOE), a joint venture of PSEG Renewable Generation and Deepwater Wind, as the preferred developer of a 350-megawatt wind farm off the coast of New Jersey. As the preferred developer, GSOE will proceed with evaluation of the project's environmental impacts and wind resources quality as well as begin the permitting process at both the state and federal levels.

GSOE's proposal calls for 96 wind turbines arranged in a rectangular grid 16 to 20 miles off the coast of Cape May and Atlantic counties (for map showing location in relation to N.J. coast, go to www.gardenstatewind.com). At this distance, the wind farm would be barely visible from shore, addressing one of the major concerns of beach communities. The wind farm could begin generating energy in 2012 with the entire project operational in 2013.

The New Jersey Energy Master Plan (EMP) calls for 20 percent of the state's New Jersey's energy to come from renewable sources by 2020, a major portion of which is envisioned to be from offshore wind. This decision marks the state's ongoing commitment to aggressively encourage the expansion and creation of clean energy solutions to meet the state's energy needs.

We will find out from the Delaware, New Jersey, and Rhode Island projects whether the considerable wind resources of the Mid-Atlantic Bight can be tapped in an affordable way. If these projects succeed that will bode well for our post-oil future. Throw in a success with getting the costs down on the Chevy Volt and we'll be able to keep moving when oil production goes into sharp decline.

New York might be next.

A year after nixing an offshore wind farm near Jones Beach, the Long Island Power Authority will explore a new, larger proposal with Con Edison for a field of up to 100 turbines off the coast of Queens.

LIPA chief executive Kevin Law today is expected to announce the formation of a working group with Con Ed to study the feasibility of a "significant" wind farm, possibly 10 miles off the Rockaways. If the two utilities can agree on a plan, they will draw up a request for proposals, perhaps early next year.

By Randall Parker 2008 October 05 08:25 PM  Energy Wind
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Polymer Hydrogel Improves Knee Surgery Outcomes

A new biomaterial boosts success rates when using the microfracture technique to restore knee cartilage.

A new biomaterial developed by Cartilix, a biotech startup based in Foster City, CA, could dramatically improve the success rate of knee-cartilage repair surgery, making the procedure more accessible to patients with bad knees. The new material, called ChonDux, consists of a polymer hydrogel that, when injected into the knee during surgery, guides the regeneration of cartilage by stimulating repair cells in the body.

So far the technique has been tested on animals and on a small human group in Europe. So you can't get this treatment unless you can get yourself enrolled in a coming US clinical trial.

This hydrogel enhances an existing knee surgery repair technique called microfracture. The microfracture approach involves drilling lots of small holes in bone where the cartilage is missing. A blood clot formed in that area signals stem cells to rush in and do repair. This new enhancement of that approach reduces the amount of scar tissue that forms and increases cartilage formation.

ChonDux consists of a hydrogel made of polyethylene glycol--a polymer commonly used in a variety of medical products--and a bioadhesive to keep the hydrogel in place after injection. First, the surgeon coats the inside of the cavity where the cartilage is missing with the bioadhesive and then, as in microfracture, drills tiny holes into the bone next to the cavity. Then the surgeon fills the empty space with the hydrogel and shines UVA light on the material, which causes the polymer to harden from a viscous liquid into a gel.The blood clot that forms from the microfracture then gets trapped in the hydrogel.

The bioadhesive in this case is chondroitin sulfate which many people take as a supplement to reduce joint pain.

One of the biggest problems with transplanting biomaterials is getting the mostly aqueous material to stick in a very slippery space, says Jennifer Elisseeff, a biomedical engineer at Johns Hopkins University, who developed ChonDux and cofounded Cartilix. The adhesive in this case consists of chondroitin sulfate--a natural component of cartilage that is chemically modified to bind to the healthy cartilage surrounding the defect, as well as to the hydrogel. "It acts like a primer that helps paint stick to the wall," Elisseeff said at a panel at the recent EmTech conference in Cambridge, MA. The adhesive prevents scar formation between the new and old cartilage.

This approach is fairly low tech. The researchers didn't grow up stem cells for injection into the knee. They also didn't use gene therapy to instruct cells to do repair. Yet those higher tech methods are needed. The existing microfracture technique has a much lower success rate in older people - probably because their stem cells are less vigorous. Younger stem cells or stem cells primed up to do repair could boost success rates.

The drilling of holes in bone as a way to stimulate repair seems crude. We need ways to coat a surface with repair stimulating materials without causing damage. Simulate the damage biochemically rather than cause real damage. Those techniques will come as the compounds that stimulate repair become better understood and more manipulable.

By Randall Parker 2008 October 05 02:53 PM  Biotech Tissue Engineering
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2008 October 04 Saturday
Painting Rooftops White Would Delay Global Warming

White paint can cool the Earth.

It turns out that a 1,000 square foot area of rooftop painted white has about the same one-time impact on global warming as cutting 10 tons of carbon dioxide emissions, he and his colleagues write in a new study soon to be published in the journal “Climatic Change.”

As sunlight pours down into Earth’s atmosphere, some of the energy is filtered out or bounces off clouds. About half the energy shines through as visible light and some of that hits the tops of houses. If a roof is white, most sunlight reflects back into space and doesn’t heat the earth. But if a roof is a dark color, the sunlight converts to heat rather than bouncing off as light. That thermal energy then radiates off the roof back toward space, where it is trapped by CO2 in the atmosphere, and then absorbed by this greenhouse gas. As a result, the world’s thermometer reads just a little higher than it did before.

If the estimated 360,000 square miles (less than 1 percent of the world’s land surface) covered by urban rooftops and pavement were a white or light color, enough sunlight would be reflected back into space to delay climate change by about 11 years, the study shows.

Put another way, boosting how much urban rooftops reflect, called albedo (al-BEE-doh) in scientific terms, would be a one-time carbon-offset equivalent to preventing 44 billion tons of CO2 from entering the atmosphere, Akbari says. It’s about the same as taking all the earth’s automobiles off the road for 11 years, the study’s authors say.

So if global warming becomes a problem we've got a cheap low tech thing we can do to delay the effects. The cooler buildings in tropical and temperate zones will cost less to air condition as well.

On the other hand, our clean energy sun is absolutely spotless. If it stays spotless then we'll need to paint everything black instead.

Sept. 30, 2008: Astronomers who count sunspots have announced that 2008 is now the "blankest year" of the Space Age.

As of Sept. 27, 2008, the sun had been blank, i.e., had no visible sunspots, on 200 days of the year. To find a year with more blank suns, you have to go back to 1954, three years before the launch of Sputnik, when the sun was blank 241 times.

"Sunspot counts are at a 50-year low," says solar physicist David Hathaway of the NASA Marshall Space Flight Center. "We're experiencing a deep minimum of the solar cycle."

But if photovoltaics become really cheap in the next 10 years (and I expect they will) then people will put PV on their rooftops and the PV material will absorb more light than white-painted roofing. What will be the net climate effect of massive PV installation? The PV electricity will displace some usage of fossil fuels. But the PV might lower the Earth's albedo (i.e. lower the amount of light reflected into space).

Planting trees also lowers the Earth's albedo because trees are often darker than the surface without trees. But trees gather solar energy and can be burned in place of fossil fuels as well.

Use of whiter materials for laying pavement offers another way to raise the Earth's albedo that won't compete with PV for the Earth's surface.

By Randall Parker 2008 October 04 11:05 PM  Climate Engineering
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2008 October 02 Thursday
Brain Scan Predicts Ketamine Anti-Depressant Effect

Depressed people whose brains respond more in their anterior cingulate cortex (ACC) when shown scary faces also experience the greatest improvement in mood in response to anti-depressant ketamine.

Two years ago, Zarate and colleagues reported that ketamine, which targets the brain chemical glutamate, can lift depressions in just hours, instead of the weeks it takes conventional antidepressants, which work through the brain chemical serotonin. Evidence suggests that glutamate likely acts closer to the source of the depression than serotonin, and is not dependant on slower mechanisms, such as the synthesis of new neurons.

Earlier imaging studies with conventional antidepressants had hinted that increased activity of the mood-regulating hub, called the anterior cingulate cortex (ACC), signals a better response.

To find out if ACC activity might also forecast response to glutamate-targeting medications, the NIMH researchers imaged the brain activity of 11 depressed patients and 11 healthy participants, using magnetoencephalography (MEG). This imaging technology can non-invasively detect brain electromagnetic activity lasting only milliseconds – the speed of communications in neural circuits – whereas other functional brain imaging techniques can only capture activity that last seconds or minutes, and some involve radiation exposure.

This precise timing enabled the MEG scanner to capture the brain's split-second responses to rapidly flashing pictures of fearful faces, a task known to activate the ACC. While healthy participants' ACC activity dropped off as they quickly habituated to the faces, patients' ACC activity showed an opposite trend. The more robust this increase, the more symptoms improved just four hours after a patient received a single infusion of ketamine.

"The ACC may be slow to respond, but not completely impaired, in patients who respond to ketamine," explained Cornwell.

While ketamine can lift depression very rapidly for some people ketamine does have side effects, especially at higher doses. Don't use it recklessly.

By Randall Parker 2008 October 02 11:08 PM  Brain Depression
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Solar Power Faces Environmentalist Opposition

Not everyone sees solar power as environmentally compatible.What is waste land to one person is a pristine ecosystem to another person.

Solar companies proposing large power plants in the Mojave Desert are facing opposition from conservationists. They say a rush to build solar here threatens to tear up large tracts of desert habitat and open space.

But where do the defenders of an unmolested Mojave come down on the question of nuclear power? It has the smallest footprint of any of the fossil fuels replacements.

The squabble is likely to intensify now that Congress this week moved forward on a long-term extension of the solar tax credit. Two other proposed bills would fast-track solar power projects looking to build on federal lands. State mandates on utilities to provide more renewable energy has created an enormous market for solar, an energy that requires two things the Mojave has in spades – acreage and sunshine. But the desert’s defenders argue that solar panels should be located on city rooftops rather than pristine lands.

One reason we are seeing more large scale solar power projects around Southern California is a state mandate for utilities to get more of their power from renewable sources of energy. This favors large scale solar power over rooftop solar. The rooftop solar also runs into zoning restrictions aimed at beautifying towns. I know people who've had trouble getting approval to put photovoltaics on their roof for example.

I expect the local rooftop zoning restrictions to lessen as prices fall and a larger fraction of homeowners (and voters) want to put PV on their own roofs. But opposition to covering deserts with PV might grow rather than shrink. If PV ever starts paying more per acre than crops (and can it?) then PV won't hit such obstacles in farm country where land has long been thought of as a productive resource.

Some analysts were predicting a double digit decline in PV prices in 2009. But initial indications are for a smaller price decline.

On Aug. 20, Zhengrong Shi, chief executive of Suntech Power Holdings, (STP) said early prices for 2009 are flat to 5% down compared with 2008. Suntech is one of the world's 10 largest solar module makers.

That same week Andrew Klump, Trina Solar's (TSL) vice president of business development, said on the quarterly conference call that the company sees price declines of just 3% to 5% in 2009.

The credit crunch and the question of US solar tax credit extension both are big question marks on 2009 PV demand.

By Randall Parker 2008 October 02 07:25 AM  Energy Solar
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