Study identifies energy efficiency as reason for evolution of upright walkingA new study provides support for the hypothesis that walking on two legs, or bipedalism,

evolved because it used less energy than quadrupedal knucklewalking.David Raichlen, an assistant professor of anthropology at The University of Arizona, conducted

the study with Michael Sockol from the University of California, Davis, who was the lead author of the paper, and Herman Pontzer from Washington University in St. Louis.

Raichlen and his colleagues will publish the article, "Chimpanzee locomotor energetics and the origin of human bipedalism” in the online early edition of the Proceedings of the National Academy of Sciences (PNAS) during the week of July 16. The print issue will be published on July 24.

Bipedalism marks a critical divergence between humans and other apes and is considered a defining characteristic of hu-man ancestors. It has been hypothesized that the reduced en-ergy cost of walking upright would have provided evolutionary advantages by de-creasing the cost of foraging.

Ground reaction force (GRF) vectors for humans and chimpanzees. © Cary Wolinsky. Michael D. Sockol, David A. Raichlen, Harman Pontzer

"For decades now researchers have debated the role of energetics and the evolution of bipedalism,” said Raichlen. "The big problem in the study of bipedalism was that there was little data out there.”

The researches collected metabolic, kinematic and kenetic data from five chimpanzees and four adult humans walking on a treadmill. The chimpanzees were trained to walk quadrupedally and bipedally on the treadmill.

Humans walking on two legs only used one-quarter of the energy that chimpanzees who knuckle-walked on four legs did. On average, the chimpanzees used the same amount of energy using two legs as they did when they used four legs. However, there was variability among chim-panzees in how much energy they used, and this difference corresponded to their different gaits and anatomy.

"We were able to tie the energetic cost in chimps to their anatomy,” said Raichlen. "We were able to show exactly why certain individuals were able to walk bipedally more cheaply than oth-ers, and we did that with biomechanical modeling.”

The biomechanical modeling revealed that more energy is used with shorter steps or more ac-tive muscle mass. Indeed, the chimpanzee with the longest stride was the most efficient walking upright.

"What those results allowed us to do was to look at the fossil record and see whether fossil ho-minins show adaptations that would have reduced bipedal energy expenditures,” said Raichlen. "We and many others have found these adaptations [such as slight increases in hindlimb exten-sion or length] in early hominins, which tells us that energetics played a pretty large role in the evolution of bipedalism.”

Study shows no change in sense of taste after tonsil removalIn a small study of patients undergoing tonsillectomy, or removal of the tonsils, none reported

an ongoing dysfunction in their sense of taste following the procedure, according to a report in the July issue of Archives of Otolaryngology–Head & Neck Surgery, one of the JAMA/Archives jour-nals.

Together with the sense of smell and nerve impulses in the mouth, "the sense of taste contrib-utes considerably to flavor perception during eating and drinking and thus plays a major role in the enjoyment of foods and beverages,” according to background information in the article. The sense of taste shows little deterioration during aging but can be weakened by disease or medica-tions. Accidental nerve damage during some medical procedures, including radiation treatment, middle ear surgery, dental or oral surgery or tonsillectomy, also can cause taste dysfunction.

Christian A. Mueller, M.D., of the University of Vienna, Austria, and colleagues asked 65 tonsil-lectomy patients (42 females, 23 males; average age 28) to rate their own sense of smell and

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taste before surgery on a scale of zero to 100, where zero is no sense of taste or smell and 100 is an excellent sense of taste and smell. Taste function and sensitivity also was assessed one day before surgery with gustatory testing, during which taste strips for four concentrations of sweet, sour, salty and bitter were applied to both sides of the front and back areas of the tongue. Between 64 and 173 days after surgery, patients were asked to report any changes to their sense of taste or smell and again asked to rate them from zero to 100. Gustatory testing was performed again on 32 patients.

On average, patients’ ratings of their sense of taste and smell decreased following surgery—the average score was 62.3 before surgery and 51.1 after surgery. However, there were no sig-nificant changes in gustatory test scores following surgery. In addition, none of the patients re-ported ongoing dysfunction in their sense of taste or smell at the follow-up questioning.

"This raises the question of whether taste ratings also depend on attentional factors,” the au-thors write. "Thus, it may be hypothesized that the patients’ ratings of taste function were influ-enced by the presence of postoperative pain, oral discomfort or wound healing during the first days and weeks after tonsillectomy.”

"A number of case reports and a few systematic investigations of patients experiencing taste disorders after tonsillectomy have been published,” they conclude. "However, based on the present results, taste loss after tonsillectomy seems to be a rare complication.”

Scientists isolate chemical in curry that may help immune system clear plaques found in Alzheimer's

Study also identified key genes involved in processFINDINGS: Researchers isolated bisdemethoxycurcumin, the active ingredient of curcuminoids – a natural substance found in turmeric root – that may help boost the immune system in clearing amyloid beta, a peptide that forms the plaques found in Alzheimer’s disease. Using blood sam-ples from Alzheimer’s disease patients, researchers found that bisdemethoxycurcumin boosted immune cells called macrophages to clear amyloid beta. In addition, researchers identified the immune genes associated with this activity.IMPACT: The study provides more insight into the role of the immune system in Alzheimer’s dis-ease and points to a new treatment approach. Researchers say that it may be possible to test a patient’s immune response with a blood sample in order to individualize treatment. The genes involved in the process, called MGAT III and Toll-like receptors, are also responsible for a number of other key functions in the immune system. The results also suggest a new drug development approach for the disease that differs from the amyloid-beta vaccine. The new approach relies on the innate immune system, which is present at birth rather than on antibodies produced by B cells, which is a later developed part of the active immune system.

Clues to future evolution of HIV come from African green monkeysMonkey viruses related to HIV may have swept across Africa more recently than previously

thought, according to new research from The University of Arizona in Tucson.A new family tree for African green monkeys shows that an HIV-like virus, simian immunodefi-

ciency virus, or SIV, first infected those monkeys after the lineage split into four species. The new research reveals the split happened about 3 million years ago.

Previously, scientists thought SIV infected an ancestor of green monkeys before the lineage split, much longer ago.

"Studying SIV helps us learn more about HIV," said the paper's first author Joel Wertheim, a doctoral candidate in the UA department of ecology and evolutionary biology. "This finding sheds light on the future direction of HIV evo-lution."

All SIVs and HIVs have a common ancestor, added se-nior author Michael Worobey, a UA assistant professor of ecology and evolutionary biology.

The new work suggests African green monkeys' SIVs, or SIVagm, may have lost their virulence more recently than the millions of years previously thought. Green monkeys almost never get sick from SIVagm. If SIVagm was once a monkey killer, the change in its virulence may shed light on the future course and timing of the evolution of HIV.

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The new research also challenges the idea that one ancient SIV was transmitted vertically, down through time, and evolved into many SIVs as its original host diverged into many different species.

The arrows on this map of Africa illustrates the UA researchers' hypothesis that SIV first infected the westernmost species of African green monkey and then moved east across

the continent. Joel Wertheim and Michael Worobey, courtesy of PLoS Pathogens.Wertheim and Worobey suggest various SIVs arose because SIVs were transmitted horizon-

tally, between primate species, and evolved into a new host-specific form only after transmis-sion.

HIV arose from chimpanzee SIV that was transmitted to humans, probably when people had contact with chimpanzee blood from hunting and butchering the animals, Worobey said.

The team's research article, "A Challenge to the Ancient Origin of SIVagm Based on African Green Monkey Mitochondrial Genomes," is in the July issue of PLoS Pathogens and can be found at http://www.plospathogens.org. The National Science Foundation and National Institutes of Health funded the research.

Previous research had sketched out the family trees, or phylogenies, of the four species of African green monkeys and their accompanying SIVagm, but Wertheim wanted to know more.

"I wasn't convinced by the evidence out there that these monkeys were infected before they speciated," Wertheim said. "So I set out to perform a rigorous test of that hypothesis."

He extensively sequenced the mitochondrial DNA genes of the four species of African green monkeys. Mitochondrial DNA is passed from mother to child.

The four green monkeys he studied are the sabaeus monkey, Chlorocebus sabaeus, which lives in western Africa; the tantalus monkey, Chlorocebus tantalus, which is found in central Africa; the vervet monkey, Chlorocebus pygerythrus, which lives in eastern and southern Africa; and the grivet monkey, Chlorocebus aethiops, which lives in northeast Africa.

The scientists used the genetic sequences to sort out the ancestral relationships among the different species of monkeys. Other researchers had already constructed phylogenies for the four different SIVagm that showed their relationships.

"We put together, for the first time, a really solid phy-logeny for African green monkeys, which we didn't have be-fore," Worobey said.

If the monkeys' ancestor had been infected with an an-cient SIV, the SIV family tree should match that of the four monkey species.

The trees didn't match."The monkey tree was significantly different from the virus

tree," Wertheim said.The researchers then looked at the geographic distribution

of the four African green monkey species. The relative ages and information on which pairs of SIVagm were most closely related revealed the probable transmission route of SIV.

The researchers hypothesize that the infection started in the westernmost species, sabaeus monkeys, moved east into neighboring tantalus monkeys, and then took one of two paths: southeast into vervets and then north into grivets or northeast into grivets and then south into vervets.

Wertheim said, "I was surprised that the geography could explain the virus phylogenetic tree, how well it fit. You just look and -- there it is!"A vervet monkey, Chlorocebus pygerythrus, taken in Serengeti National Park in Tanzania.

Photo by Joel Wertheim, courtesy of PLoS Pathogens.The UA researchers suggest that in the border zones where two African green monkey

species' ranges come in contact, transmission probably happened during interspecies sexual en-counters or fights. Wertheim pointed out that hybrid monkeys have been seen in the wild in the border zones.

Worobey said, "Some of the trends we see give new evidence on how quickly or slowly these changes take place."

Citing some laboratory research that suggests HIVs from the late 1980s are more virulent than HIVs from the 2000s, Worobey added, "For HIV, the really cool thing is that these changes can take place on a more rapid timeline that previously thought."

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Wertheim adds, "Understanding how emerging infectious diseases evolve in their natural host organism helps us understand the disease's possible trajectory."

The team's next steps are figuring out exactly when SIV infected African green monkeys and studying SIVs in other species of monkeys.

Combating counterfeit Rx from ChinaAgencies worldwide are cracking down on counterfeit pharmaceuticals, and much of the focus

has been on China, where an official was recently executed for approving fake medicines. While most of these drugs reach consumers through online or illegal suppliers, there’s a growing threat to outlets considered more safe, like the neighborhood pharmacy, said Temple University phar-macoeconomist, Albert Wertheimer, Ph.D., who will talk about combating counterfeit pharma-ceuticals coming out of China at a U.S. Patent and Trademark Office (USPTO) seminar on July 23 and 24 in Philadelphia.

Internet pharmacies, which are extremely difficult to monitor and regulate, pose the biggest threat, but counterfeits could soon make their way into mainstream channels via sophisticated fakery and old-fashioned bribery.

"Counterfeiters have gotten very good at replicating labels and packaging,” said Wertheimer, who will focus on techniques used in other fields to identify fake goods, as well as the impor-tance of detecting counterfeits early in the supply chain.

"Governments and industry must realize that when the danger actually becomes visible, pa-tients may already have suffered harm,” he said.

Global efforts are underway to develop an international database that documents all counter-feit drug activity. Experts also urge greater coordination with the pharmaceutical industry.

Additionally, officials are looking at effective strategies used in other fields to fight counterfeit-ing including a pedigree system, which would record the path of ownership and location of a drug shipment. Each purchaser along the supply chain would add information and verify authen-ticity. Another technique uses sensors, inert substances that can be added to a liquid or pill, that would verify authenticity. Officials could also borrow a strategy from the retail industry – ra-diofrequency identification, whereby drugs would be tagged similar to clothing items.

"Still, technology cannot be a permanent, foolproof solution, and only by improving importa-tion and regulation policy can counterfeiting be contained further. The Food and Drug Adminis-tration's Counterfeit Drug Task Force believes that attacking the problem through multiple routes will be the most effective way to combat drug counterfeiting,” Wertheimer said.

In general, counterfeit means that a drug can lack an important ingredient, contain a harmful ingredient or be mislabeled. Some of the most commonly counterfeited drugs include those for erectile dysfunction, depression, anxiety and infection. In a recent study, the World Health Orga-nization determined global sales of counterfeit drugs to be $32 billion in 2003 – 10 percent of all medicines sold worldwide.

"Drug counterfeiting is a threat that every nation faces and the activity is very difficult to iden-tify, trace, and combat. The growth of online drug sales, counterfeiters' increasing technologic skill, and a false sense of security in countries with stringent regulatory measures are among the factors that are enabling the spread of this criminal activity,” Wertheimer said.

U.S. and Chinese speakers at the USPTO event will be drawn from the academic and govern-mental fields as well as industry. Conference attendees will include businesses and companies doing or contemplating doing business with or in China, as well as those who want to protect themselves against counterfeiting and piracy from China.

Diet very high in fruit, vegetables does not appear to reduce risk of breast cancer recurrence

Women with early stage breast cancer who adopted a diet very high in vegetables, fruit and fiber and low in fat did not have a lower risk of breast cancer recurrence compared to women who followed a diet of five or more servings a day of fruit and vegetables (the "5-A-Day” diet), according to a study in the July 18 issue of JAMA.

"Considerable evidence from preclinical studies indicates that plant-derived foods contain an-ticarcinogens. A comprehensive review of the literature found that a diet high in vegetables and fruit probably decreases breast cancer risk and that a diet high in total fat possibly increases risk. However, evidence of an association between a diet high in vegetables and fruit and low in total fat and prevention of cancer progression has been mixed in epidemiological studies,” the authors write.

John P. Pierce, Ph.D., of the University of California, San Diego, La Jolla, Calif., and colleagues conducted the Women’s Healthy Eating and Living (WHEL) Study to assess whether a dietary pattern very high in vegetables, fruit, and fiber and low in fat reduces the risks of recurrent and

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new primary breast cancer and all-cause death among women with previously treated early stage breast cancer. The randomized controlled trial included 3,088 women who were previously treated for early stage breast cancer (18 to 70 years old at diagnosis). Women were enrolled be-tween 1995 and 2000 and followed up through June 2006.

The intervention group (n = 1,537) was randomly assigned to receive a telephone counseling program supplemented with cooking classes and newsletters that promoted daily targets of five vegetable servings plus 16 oz. of vegetable juice; three fruit servings; 30 grams of fiber; and 15 percent to 20 percent of energy intake from fat. The comparison group (n = 1,551) was provided with print materials describing the "5-A-Day” dietary guidelines.

From comparable dietary patterns at baseline, the intervention group achieved and main-tained the following statistically significant differences vs. the comparison group through four years: servings of vegetables, +65 percent; fruit, +25 percent; fiber, +30 percent, and energy intake from fat, -13 percent. Throughout the study, women in both groups received similar clini-cal care.

During the study, 518 participants had a breast cancer event, including 256 participants (16.7 percent) in the intervention group and 262 participants (16.9 percent) in the comparison group. There were 315 deaths reported within the study period, with 155 (10.1 percent) in the interven-tion group and 160 (10.3 percent) in the comparison group. More than 80 percent of all deaths were due to breast cancer. No significant benefit in preventing breast cancer recurrence was ob-served overall among population subgroups characterized by demographic characteristics, base-line diet, or type of initial tumor or breast cancer treatment.

"In conclusion, during [an average] 7.3-year follow-up, we found no evidence that adoption of a dietary pattern very high in vegetables, fruit, and fiber and low in fat vs. a 5-a-day fruit and vegetable diet prevents breast cancer recurrence or death among women with previously treated early stage breast cancer,” the authors write. (JAMA. 2007;298(3):289-298. Available pre-embargo to the media at www.jamamedia.org)

Vitamin C offers little protection against coldsUnless you run marathons, you probably won’t get much protection from common colds by

taking a daily supplemental dose of vitamin C, according to an updated review of 30 studies.Conducted over several decades and including more than 11,000 people who took daily doses

of at least 200 milligrams, the review also shows that vitamin C (ascorbic acid) does little to re-duce the length or severity of a cold, according to the researchers at the Australian National Uni-versity and the University of Helsinki.

However, they found that people exposed to periods of high stress — such as marathon run-ners, skiers and soldiers on sub-arctic exercises — were 50 percent less likely to catch a cold if they took a daily dose of vitamin C.

For most people, the benefit of the popular remedy is so slight when it comes to colds that it is not worth the effort or expense, the authors say. "It doesn’t make sense to take vitamin C 365 days a year to lessen the chance of catching a cold,” said co-author Harri Hemilä, a professor in the Department of Public Health at University of Helsinki in Finland.

The review appears in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

Since the discovery of vitamin C in the 1930s, controversy regarding its efficacy in treating ail-ments from lung infections to colds has surrounded it. In the 1970s, Nobel Prize-winning chemist Linus Pauling popularized its regular use. His book, "Vitamin C and the Common Cold,” encour-aged people to take 1,000 milligrams of the vitamin daily.

The current recommended daily allowance of vitamin C is 60 milligrams. An eight-ounce glass of orange juice has about 97 milligrams of vitamin C.

Despite early mixed results and later evidence against its efficacy, charismatic Pauling be-came the world’s vitamin C champion. "Pauling never recanted and never backed down,” said Wallace Sampson, founding editor of the Scientific Review of Alternative Medicine and emeritus professor of medicine at Stanford University.

Regardless of the evidence against it, vitamin C remains popular because many people —in-cluding those funding studies — want to believe that it works, said Sampson, who debated Paul-ing on the radio and in letters.

These days, there is less interest in studying vitamin C and the common cold, said Hemilä, who has studied the vitamin for more than 25 years. The Cochrane Review was originally pub-lished in 1998 and updated in 2004 and this year. The latest update includes a single new study on the Vitamin C-cold connection.

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However, researchers continue to examine vitamin C alone and in combination with other vi-tamins and substances, such as Echinacea, for its efficacy in preventing and treating diseases and conditions, including cancer. This is not necessarily a good thing, Sampson said. "It’s broad-side quackery.”

Hemilä said he sees little use in further study for colds for adults. However, he would like to see more studies on vitamin C and colds in children and vitamin C and pneumonia. Vitamin C is not a panacea, but it is not useless either, Hemilä said. "Pauling was overly optimistic, but he wasn’t completely wrong.”

Universal flu vaccine being tested on humansGhent, Belgium -- A universal influenza vaccine that has been pioneered by researchers from VIB and Ghent University is being tested for the first time on humans by the British-American biotech company Acambis. This vaccine is intended to provide protection against all ‘A’ strains of the virus that causes human influenza, including pandemic strains.Flu

Influenza is an acute infection of the bronchial tubes and is caused by the influenza virus. Flu is probably one of the most underestimated diseases: it is highly contagious and causes people to feel deathly ill. An average of 5% of the world’s population is annually infected with this virus. This leads to 3 to 5 million hospitalizations and 250,000 to 500,000 deaths per year. In Belgium, an average of 1500 people die of flu each year. A ‘more severe flu year’ - such as the winter of 1989-1990 - claimed in our country 4500 victims. Besides the annual flu epidemics, there is the possibility of a pandemic, which occurs every 10 to 30 years and causes more severe disease symptoms and a higher mortality rate. During the pandemic caused by the Spanish flu in 1918-1919, the number of deaths worldwide even rose to over 50 million.Why an annual vaccine?

Today’s flu vaccines need to be adapted every year and, consequently, they must also be ad-ministered again every year. The external structure of the flu virus mutates regularly, giving rise to new strains of flu. Due to these frequent mutations, the virus is able to elude the antibodies that have been built up during a previous infection or vaccination. This is why we run the risk of catching the flu each year and also why a new flu vaccine must be developed each year. A uni-versal flu vaccine that provides broad and lifelong protection - like the vaccines we have for po-lio, hepatitis B or measles - is not yet available.Universal flu vaccine

In the 1990s, VIB researchers connected to Ghent University, under the direction of Prof. Emeritus Walter Fiers, invented a universal flu vaccine. One protein on the surface of the in-fluenza virus, the so-called M2 protein, remains unchanged in all human flu viruses known, in-cluding the strains that caused the pandemics in the last century. On the basis of the M2-protein they developed a vaccine and successfully tested it on mice and other laboratory animals: the M2 vaccine provided total protection against ‘A’ strains of flu, without side effects. Furthermore, this universal influenza vaccine is the first example of a vaccine inducing a protective immune response that normally does not occur in nature, for example following infection by a virus or a bacterium.Clinical trials on humans

Acambis - a biotech company that specializes in the development of vaccines - has been ex-clusively licensed rights to VIB’s flu vaccine patent portfolio and has entered into a collaboration with VIB for further development work. At the moment, Phase I clinical trials on humans are un-derway - that is, the candidate vaccine is being administered to a small group of healthy people in order to verify the safety of the product and to provide an initial insight into the vaccine’s ef-fect on the human immune system.Promising outlook

Xavier Saelens, Prof. Emeritus Willy Min Jou, and Prof. Emeritus Walter Fiers are leading the fundamental research forward with respect to protection against influenza epidemics and pan-demics. This involves, amongst other, supporting research required for the planned Phase II and III clinical trials. Through their collaboration with Acambis, they hope that annual flu vaccines can ultimately be replaced by the new, universal flu vaccine. The goal for this vaccine is that two in-oculations would suffice to protect people against all ‘A’ strains of flu.Disease-free mosquito bred to disease-carrier can have all disease-free prog-

enyBlacksburg, Va. -- A decade ago, scientists announced the ability to introduce foreign genes into the mosquito genome. A year ago, scientists announced the successful use of an artificial gene that prevented a virus from replicating within mosquitoes. But how does one apply what can be done

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with a small number of mosquitoes in a lab to the tens of millions of mosquitoes that spread dis-ease worldwide"

Researchers from Virginia Tech and the University of California Irvine have demonstrated the ability to express a foreign gene exclusively in the female mosquito germline, a necessary pre-requisite to future genetic control strategies in mosquitoes where all progeny of lab and wild mosquitoes will have the gene that blocks virus replication – or whatever trait has been intro-duced into the lab mosquitoes.

Until now, if lab-grown mosquitoes that are unable to support virus replication were to mate with wild, disease-vector mosquitoes, only half of their off-spring would have the anti-virus gene. Researchers have been working on how to skew the outcome so that all off-spring lack the ability to spread disease. However, these experiments have been hampered by the inability to express foreign genes in the mosquito germ cells.

"We needed to gain access to the cells in the reproductive germline to change the way traits are inherited,” said Zach Adelman, assistant professor of entomology and a member of the Vec-tor-Borne Infectious Disease Research Group at Virginia Tech (www.vectorborne.ibphs.vt.edu).

Adelman will discuss what the research breakthrough means for the future control of diseases spread by mosquitoes in his talk, "Dengue Viruses and Mosquitoes, Scourge of the Developing World: Can Genetic Control Make a Difference"” to be presented Thursday morning, July 19, at the 2007 Biotechnology Education Conference at the Inn at Virginia Tech, hosted by the Fralin Biotechnology Center at Virginia Tech.

The research appeared in the June 12, 2007, Proceedings of the National Academy of Sciences (PNAS www.pnas.org/cgi/content/abstract/104/24/9970), in the article, "Nanos gene control DNA mediates developmentally-regulated transposition in the yellow fever mosquito Aedes aegypti," by Adelman, assistant professor of entomology at Virginia Tech, and UC Irvine colleagues Nijole Jasinskiene, Sedef Onal, Jennifer Juhn, Aurora Ashikyan, Michael Salampessy, Todd MacCauley, and Anthony A. James.

Working with Aedes aegypti, the mosquito that carries yellow fever and dengue fever viruses, the researchers are working to create a "gene-drive system” by using instructions copied from the nanos (nos) gene, which is essential for germline formation. "Think of the nanos instructions as a key to a room,” Adelman said.

Using the nanos "key,” the researcher team successfully achieved germline-specific expres-sion of Mos1, an enzyme isolated from the housefly that is a transposable element (TE) -- a piece of genetic material that moves around. Mos1 can also move anything attached to it and can du-plicate itself and whatever is attached to it, such as a gene that directs the dengue virus to stop replication.

"The research reported in PNAS shows that we can access the female germline and we can perform experiments in the germline,” said Adelman. "The nanos control sequences show prom-ise as a part of a TE-based gene drive system,” he said.

Adelman was also a member of the team that genetically modified Aedes aegypti so that it was resistant to dengue virus type 2 and showed that the virus was unable to replicate. That re-search, reported in PNAS on March 14, 2006, also took advantage of the Mos1 transformation system. The anti-viral gene was activated in the mosquito gut following a blood meal. The re-search was a collaboration of researchers at Colorado State University and UC Irvine, lead by Alexander W.E. Franz at Colorado State. Adelman, who joined the Virginia Tech faculty two years ago, was previously at UC Irvine.

Species detectives track unseen evolutionNew species are evading detection using a foolproof disguise – their own unchanged appear-

ance. Research published in the online open access journal, BMC Evolutionary Biology, suggests that the phenomenon of different animal species not being visually distinct despite other signifi-cant genetic differences is widespread in the animal kingdom. DNA profiles and distinct mating groups are the only way to spot an evolutionary splinter group from their look-alike cousins, in-troducing uncertainty to biodiversity estimates globally.

Markus Pfenninger and Klaus Schwenk searched the Zoological Record database (1978-2006) to pinpoint reports of hidden (cryptic) species both biogeographically and taxonomically, and found 2207 examples. Pfenninger and Schwenk, who are from Germany based at J.W. Goethe-Universität in Frankfurt found evidence for cryptic species evenly spread among all major branches of the animal kingdom. They also found that cryptic species were just as likely to be found in all biogeographical regions.

The findings go against received wisdom that the insect or reptile branches of the animal kingdom are more likely to harbour cryptic species, and that these are more likely to be found in

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the tropics than in temperate regions. Zoologists should therefore consider factoring in a degree of cryptic diversity as a random error in all biodiversity assessments.

A cryptic species complex is a group of species that is reproductively isolated from each other - but lacking conspicuous differences in outward appearance. Researchers using techniques such as polymerase chain reaction (PCR) and DNA sequencing have increasingly discovered - often unexpectedly - that similar-looking animals within a presumed species are in fact genetically di-vergent. As well as highlighting hidden biodiversity among creatures zoologists have already cat-alogued, the findings have implications for conservation efforts. Another possibility is that pathogens, parasites and invasive species disguised as their relatives may yet remain unde-tected, representing a potential human health threat.

Nanoparticles make cancer cells magnetic* 16 July 2007

* NewScientist.com news service* Paula Gould

Turning cancer cells into mini magnets by using nanoparticles could make biopsies so sensi-tive and efficient that there will be no need to repeat these invasive tests.

Biopsy results can be ambiguous: sometimes they can be negative simply because there are too few malignant cells in the sample to be detected - not because all trace of disease has gone. Now researchers from the University of New Mexico and the company Senior Scientific, both in Albuquerque, have come up with a solution that harnesses the power of magnetic attraction.

The idea is to use magnetic iron oxide nanoparticles encased in a biocompatible material. These in turn can be coated with antibodies that bind to chemicals found only in cancerous cells. When injected into the body, thousands of the particles stick to cancer cells, turning them into miniature magnets. The cells can then be drawn towards magnets encased in the tip of a biopsy needle (Physics in Medicine and Biology, vol 52, p 4009).

A mathematical model of the system confirmed that significant numbers of cancer cells, laden with nanoparticles, could be attracted to a needle within two or three minutes. In the lab, the re-searchers showed that a magnetised needle could attract leukaemia cells surrounded by nanoparticles and suspended in blood or other synthetic materials designed to mimic bodily flu-ids. Nanoparticles have been used before to destroy diseased cells but this is the first time they have actually retrieved cells.

The technique could benefit people with leukaemia, who must undergo regular bone marrow biopsies to check for signs of lingering disease. "Quite often, for example, in young children, doc-tors have to do several biopsies to get enough bone marrow," says Ed Flynn, president of Senior Scientific. It might also be possible to detect cells from breast, prostate, and ovarian cancers that have spread to other parts of the body in amounts too tiny to sample with an ordinary nee-dle. The researchers are now seeking approval to test the method on human volunteers.

Bruce Morland, a paediatric oncologist at Birmingham Children's Hospital in the UK says that the idea would have to compete with techniques that have recently made it easier to detect tiny amounts of leukaemia cells in biopsies. "I am tempted to think that this technique will not be any more sensitive," he says. It might be used, however, to detect low levels of cancer that have spread "silently" into the bone marrow, he adds.

Invention: biological nanobattery* 11:34 16 July 2007

* NewScientist.com news service* Justin Mullins

Bio-nanobatteryNobody has yet worked out how to make a good nanobattery, so nanoscale devices are typi-

cally driven by power sources many times their own size.A key problem is how to assemble a battery on such a tiny scale, and a number of research

groups have been working on exploiting the way biological molecules self-assemble for this task.NASA says one promising avenue is exploiting the ability of the iron-containing protein ferritin

to carry either a positive or negative charge.Ferritin also self-assembles relatively easily into a uniform nanolayer. So, the agency says, it

is straightforward to create a layer of ferritin and then cover it with another layer of the opposite charge. The result is a capacitor just a few nanometres thick that can store charge between its layers - in other words a battery.

Adding more layers of alternately charged ferritin increases the capacitance of this bio-nanobattery. NASA reckons its battery is not only stable and robust, but can be produced easily and quickly too. Read the full bio-nanobattery patent application.Blood-flow imaging

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Magnetic resonance imaging (MRI) produces detailed images of the inner body. Now David Al-sop, a professor of radiology at the Beth Israel Deaconess Medical Center in Boston, US, has come up with a way of using MRI to create images of fluid flow inside the body as well.

MRI works by aligning the nuclei of atoms using a powerful magnetic field, and then zapping them with radio waves. The way the nuclei re-emit radio waves can reveal all kinds clues about their environment - its chemical composition, for instance.

Alsop says it is also possible to work out how a sample of nuclei is moving, say, within a fluid. This is done by zapping them with a focused sequence of radio pulses, which distinguishes them from similar nuclei nearby, and then waiting to see how the nuclei have moved when they re-emit.

He says the technique could be particularly useful for studying the detailed pattern of blood flow within the brain. Read the full blood flow imaging patent applicationUltrasonic dish dryer

With an eye to improving the environmental footprint of its dishwashers, the German engi-neering company Bosch has devised a new way to dry dishes

The conventional method is to heat the dishes while they are being washed. The dishes retain thermal energy, which heats any leftover water so that it evaporates quickly once the wash is over.

Bosch says that zapping the dishes with ultrasound instead could be a far more energy effi-cient way of drying them off.

The sound waves make surface water vibrate, causing it to break up into droplets. The waves also reduce the cohesion of the droplets so they roll off dishes more quickly. Sound alone is un-likely to dry your dishes completely but Bosch hopes that combining the technique with minimal heating or fan drying will make dishwashers far more energy efficient. Read the full ultrasonic dish dryer patent application.

Spite is a uniquely human emotion* 22:00 16 July 2007

* NewScientist.com news service* Colin Barras

It used to be easy to separate man from beast. Then we realised animals, too, can experience sophisticated emotions and communicate through language. But there is one thing that is be-yond even our closest relatives, chimpanzees. And that is the ability to be spiteful.

Keith Jensen and his team at the Max Planck Institute for Evolutionary Anthropology at Leipzig, Germany, conducted experiments in which they placed a food-laden table in front of a caged chimp.

Attached to the table was a string the chimp could pull to collapse the table. The chimp re-sisted the urge to pull the string as long as the food was within its reach. But when the re-searchers moved the food to the opposite side of the table, the frustrated chimp collapsed the table in 30% of the trials.

In a second experiment, the researchers placed a second chimp in a cage at the opposite side of the table. Moving the food across the table now benefited the second chimp at the cost of the first. If the first chimp wanted to be spiteful, it could simply collapse the table and prevent its ri-val from feeding. But the chimps tested merely showed the same level of frustration as before, collapsing the table 30% of the time.

But if the second chimp attempted to move the food closer to itself, by pulling a string of its own, the first chimp reacted angrily, collapsing the table 50% of the time.Point of view

Spite is a common human reaction, says Jensen. "Imagine you're a kid at a birthday party. The mother gives you cake, then takes it away and gives it to another kid. It's not his fault, but you'll still be annoyed with him because of his good fortune. But chimps don't care who's got the cake, just who took it from them," he explains. In other words, chimps fail to see things from another's point of view.

And if a chimp's lack of empathy leaves it unable to feel spite, it may also fail to behave altru-istically, says behavioural ecologist Rufus Johnstone of the University of Cambridge in the UK. "There have been experiments that gave chimps the chance to be nice to another at no cost to themselves, but they weren't interested. They didn't have a human propensity to be nice," he says.

"This is where things get tricky," admits Jensen. "Other papers coming out of our research group show chimps are altruistic. One interpretation is that one set of researchers isn't doing their job properly, but we don't like that one! Maybe altruistic tendencies operate in a narrow range in chimps, and a broader range in humans."

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In showing that chimps lack spite, the researchers may actually have shown that a set of con-nected emotions remains unique to humans. "Many differences obviously remain," says Jensen. "Humans actually care about outcomes affecting others. The good side of that is altruism. Spite is the evil twin that can't be separated from it." Journal reference: Proceedings of the National Acad-emy of Sciences (DOI: 10.1073/pnas.0705555104)

Taking drugs with food may take a bite out of costs* 23:00 16 July 2007

* NewScientist.com news service* Roxanne Khamsi

Taking an expensive breast cancer drug on a full stomach – as opposed to an empty one as prescribed – could save a patient or their health authority $1700 (£835) a month or more, ac-cording to an analysis of data from clinical trials.

The approach, which might also work for other drugs, is based on the fact that certain foods can delay the breakdown of medications in the body. Doctors stress, however, that people should not yet attempt this cost-cutting method until studies demonstrate its safety.

In general, taking pills with food against the label's advice can lead to an overdose. For exam-ple, drinking grapefruit juice can interfere with the body's ability to handle cholesterol-lowering statin drugs.

For this reason, pharmaceutical companies must provide the US Food and Drug Administration (FDA) with information on how eating a meal can influence the absorption of their products.

This was the case when GlaxoSmithKline sought approval for its anticancer drug lapatinib (known as Tykerb in the US and Tycerb in Europe).Higher blood levels

Pharmaceutical companies generally tell patients in early drug trials to take the medication on an empty stomach, as this helps reduce the variables between patients.

In this instance, when researchers later conducted the food-interaction experiments involving lapatinib, they found that taking it at mealtime raised blood levels of the drug far above those shown as safe in previous trials. This meant that the drug label would have to advise patients to take the pill on an empty stomach.

The FDA approved lapatinib in March 2007 to treat breast cancers that have not responded to other medications. Specifically, the drug fights breast cancers that contain an excess of a protein called "human epidermal growth factor receptor 2" (HER2), and have spread through the body.

This subtype of breast cancer claims the lives about 8000 to 10,000 US women each year, ac-cording to the American Cancer Society. But this help does not come cheap. Lapatinib costs a patient roughly $2900 a month, a large sum, particularly for those who lack health insurance.

Ezra Cohen and Mark Ratain at the University of Chicago, Illinois, US wondered if taking ad-vantage of changes in lapatinib absorption after eating could reduce this cost.

Based on clinical trial data submitted to the FDA, they calculated that taking the medication with a low-fat meal or high-fat meal could increase the amount of lapatinib circulating in the blood by 1.7 and 3.3 times, respectively. Adding grapefruit juice to the mix would reduce costs further still.

"We expect that one 250 milligram lapatinib pill accompanied by food and washed down with a glass of grapefruit juice may yield plasma concentrations comparable to five 250 milligram pills on an empty stomach," Ratain says.

People who pop a pill with a meal, but no grapefruit juice, are calculated to get the equivalent effect of three pills, and would save around $1700 a month.Experiment warning

"It's kind of akin to pill splitting," says Steven Pearson, of Harvard Medical School in Boston, Massachusetts US. But he thinks the approach is unlikely to be the first choice strategy for mak-ing medicines more affordable. Pearson is working to develop a review board that would exam-ine ways to improve cost-effectiveness of drugs in the US.

Pearson says that more sweeping changes – such as providing universal health insurance and reaching a consensus on how much patients should have to pay for meds in the first place – should take top priority.

Pharmaceutical companies argue that high drug prices result from the huge investment re-quired in research and development. But patient advocacy groups have countered that much of the extra money goes into the pockets of shareholders, rather than into such research. They say that there is lots of room for price cutting.

While this debate continues, Cohen urges people not to experiment with taking lapatinib with meals until more research demonstrates the safety of doing so. "This is not something that we

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suggest people try at home. This is something that should be studied," says Cohen, adding that an overdose of lapatinib could perhaps cause a heart attack.

He says that these types of trials will only happen if the public demands them: "In part it has to come from patient advocacy groups who say this needs to be studied."

Cohen adds that he and his colleagues are looking at whether taking other medications, such as the immune suppressant rapamycin, with food could possibly lower drug costs. Journal refer-ence: Journal of Clinical Oncology (DOI: 10.1200/JCO.2007.12.0758)

Why Did Rome Fall? It's Time for New AnswersBy Peter Heather

Mr. Heather is professor at Worcester College, University of Oxford, and the author of The Fall of the Roman Empire: A New History of Rome and the Barbarians (Oxford University

Press).The Roman Empire stretched from Hadrian’s Wall to northern Iraq, and from the mouth of the

Rhine to the Atlas Mountains of North Africa. It was the largest state that western Eurasia has ever seen. It was also extremely long-lived. Roman power prevailed over most of these domains for five hundred years -- and all this in a period where the speed of bureaucratic functioning and of military response rattled along at 45 kilometres a day, something like one tenth of modern counterparts. Measured in terms of how long it took real people to get places, the Roman Empire was arguably ten times as big as it appears from the map.

The epic scale of the Empire’s existence has always sharpened interest in its collapse, particu-larly that of the west, which ceased to exist on the deposition of Romulus Augustulus in 476. Since Gibbon -- while some role has always been allocated to outside invaders -- explanation has tended to focus on a range of internal transformations and problems as the prime movers in the processes of Roman imperial collapse. By the mid-twentieth century, causation commonly con-centrated upon preceding economic collapse.

This entire vision of late Roman economic collapse was based, however, on assorted refer-ences to hyper-inflation in the third century and to various problems associated with the raising of taxation in the fourth. It has been overturned since the 1970s, when archaeologists devel-oped, for the first time, a method for sampling general levels of rural productivity. Modern ploughing bites deep into long-submerged stratigraphic layers, bringing to the surface much an-cient pottery. Long-term regional survey projects spent long summers collecting every fragment in the target zones, and every winter analyzing the results. Once Roman pottery sequences be-came so well-known that many pots could be dated to within ten to twenty years, and excava-tions established what surface density of pottery was likely to reflect the existence of a settle-ment underneath, two things became possible. Dense pottery assemblages made it possible to estimate the number of Roman settlements in any region, and the dating patterns of those as-semblages then made it possible to know when precisely any particular settlement had been oc-cupied. Against all expectation, the fourth century – immediately prior to fifth century collapse - has emerged as the period of maximum agricultural activity, not the minimum as the old views supposed, for the vast majority of the Empire. Total rural output, and hence total GIP – gross im-perial product – was clearly higher in the later Roman period, than ever before. It is now no longer possible to explain fifth-century political collapse in terms of preceding economic crisis.

What the hyper-inflation was all about, in fact, was minting enough silver coins to pay an army which was increasing in size out of all proportion to the metalwork stock of silver available. And this, straightforwardly, was the product of exogenous shock. From the 230s onwards, the Sassa-nian dynasty reorganized a huge region of the Near East - Iraq and Iran in modern terms - to cre-ate a superpower rival to the Roman Empire. The new power announced itself with three mas-sive victories over different Roman Emperors, the last of whom, Valerian, was first captured, then skinned and tanned after his death. The Persian threat was eventually countered by the end of the third century, but it took fifty years of military and fiscal adjustment to mobilize the necessary resources. This narrower vision of third-century crisis makes much more sense of the overwhelming archaeological evidence for fourth-century prosperity, and, of the brute fact that, even after the fall of the west in the fifth century, the eastern half of the Empire – operating with the same institutions – carried on successfully for centuries. It also poses Gibbon’s question again. If there is no sign of major dislocation within the late Roman imperial system of the fourth century, why did its western half collapse in the fifth?

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Early in the third century, the traditional cast of small, largely Germanic groupings which had long confronted Ro-man power across its European frontiers was replaced by a smaller number of larger entities. This refashioning pre-vailed all along Rome’s European frontiers, from the new Frankish coalition at the mouth of the Rhine, to the Black Sea where Goths emerged as the new power in the land. As another large body of archaeological evidence has now shown, much more was afoot here than mere changes of name. In the course of the Roman period – broadly the first four centuries AD – central and northern Europe saw its own economic revolution. There was a massive increase in agricultural production, fuelled by an intensification of farming regimes, accompanied by unmistakable signs of increasing differentials in wealth and status between differ-ent sections of society, with an ever greater prominence being assumed by a militarized segment of the male popu-lation. It is these broader transformations which underlay the appearance of the new names on the other side of Rome’s frontiers, and most had been stimulated by eco-nomic, political and even cultural interactions with the Ro-man Empire. These new entities proved much more formi-dable than those they replaced, operating as only semi-subdued clients of the Empire. They did contribute to impe-rial armies on occasion, but also required regular Roman military campaigning and targeted foreign aid to willing kings to keep them in line. The balance of power in its favor, which had allowed the Roman Empire to come into existence, was being eroded not just by the Sassanians, but also by the new structures of non-Roman Europe.

Some important contingent sequences of events also contributed to the fall of the western Empire. From c.370, the nomadic Huns suddenly exploded to prominence on the eastern fringes of Europe, generating two major pulses of migration into the Roman world, one 376-80, the other 405-8. By 440, their different original components – more than half a dozen in total - had coa-lesced into two major groupings, each much larger than any of the groups which had existed be-yond the frontier in the fourth century: the Visigoths in southern Gaul, the Vandals in North Africa, both representing amalgamations of three separate immigrant groups of 10,000 warriors plus. The immigrants had in the process inflicted great damage on west Roman state structures, by first mincing its armies and then preventing their proper replacement either by ravaging or annexing key areas of its tax base. This in turn allowed Anglo-Saxons and Franks to take over former Roman territories in Britain and north-eastern Gaul, weakening the state still further. The immigrants also acted as alternative sources of political magnetism for local Roman elites. Given that Roman elites were all landowners, and could not therefore move their assets to more desir-able locales, they were faced with little choice but to come to terms with immigrants as they be-came locally dominant, or risk losing their wealth. In this way, the west Roman state eventually withered to extinction, if not without vigorous martial efforts to restore its fortunes, as its rev-enues fell away and it could no longer put effective forces in the field.

Without the contingent impact of the Huns, the two main pulses of migration would never have occurred in short enough order to prevent the Roman authorities from dealing with the mi-grants, which had each group arrived separately, they certainly could. The important contribu-tion of internal Roman limitations is also clear, not least in the state’s inability to increase agri-cultural production still further beyond fourth-century levels as crisis began to bite after 400. The ability of the immigrants to detach Roman landowners politically from their allegiance also re-flects the naturally loose levels of control exercised locally by such a geographically vast state encumbered with such primitive modes of communication. But even giving these points their due weight, external factors – in the persons of the immigrants of 376-80 and 405-8 – were the prime mover behind western imperial collapse. The Empire’s internal limitations only came into play because the immigrants put pressure on its structures, and there is no sign that, by them-selves, these limitations – none of them new - would have been enough to bring the Empire down, any more than they had been over the preceding half a millennium.

The more contingent aspects of the crisis could not have had the same cumulative effect, like-wise, without the preceding transformation of Germanic society. Had the Huns arrived in the sec-ond century, the Germanic groups that might then have been set on the march would not have

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been large enough to survive their initial brush with Roman power. By the same token, the pro-cesses of political amalgamation required to generate warrior groupings of a few tens of thou-sands, on the scale of the fifth-century Visigoths or Vandals, would have been so complex, in-volving so many small contingents, that they could not have been completed successfully before the individual groups were destroyed by a Roman Empire, which prior to the rise of Persia, still had plenty of fiscal/military slack in its systems. There is a strong sense, therefore, in which im-perial Roman power and wealth created its own nemesis, by generating opposing forces which were powerful enough to match its military might. And here, if nowhere else, the fall of Rome might still have lessons which modern Empires would do well to ponder.

Exercise, exercise, rest, repeat -- how a break can help your workoutRepeated sessions of exercise burn more fat than a single, long session

Bethesda, Md. (July 18, 2007) — Taking a break in the middle of your workout may metabolize more fat than exercising without stopping, according to a recent study in Japan. Researchers conducted the first known study to compare these two exercise methods—exercising continually in one long bout versus breaking up the same workout with a rest period. The findings could change the way we approach exercise. Who wouldn’t want to take a breather for that"

"Many people believe prolonged exercise will be optimal in order to reduce body fat, but our study has shown that repetitions of shorter exercise may cause enhancements of fat mobiliza-tion and utilization during and after the exercise. These findings will be informative about the de-sign of [future] exercise regimens,” said lead researcher Kazushige Goto, Ph.D. "Most people are reluctant to perform a single bout of prolonged exercise. The repeated exercise with shorter bouts of exercise will be a great help [in keeping up with fitness].”

This finding is part of a study entitled Enhancement of fat metabolism by repeated bouts of moderate endurance exercise, found in the June 2007 edition of the Journal of Applied Physiol-ogy, which is published by the American Physiological Society. It was conducted by Kazushige Goto, of both the Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Tokyo, Japan and the Institute of Sports Medicine, Bispebjerg Hospital, Copen-hagen, Denmark; Naokata Ishii, of the Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Tokyo, Japan; and Ayuko Mizuno and Kaoru Takamatsu, both of the Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.Summary of Methodology

The researchers used seven healthy (avg. body mass: 66.1, percentage fat: 17.6) men with an average age of 25 who were physically active and familiar with exercise and had them perform three separate trials:

* one single bout of 60-min exercise followed with a 60-min recovery period (Single)* two bouts of 30-min exercise with a 20-min rest after the first 30-min bout, along with a 60-

min recovery period at the end (Repeated)* one 60-min rest period (Control)The men performed each trial at the same time of day after fasting overnight. They exercised

on a single ergometer (cycling machine) at the commonly recommended exercise prescription of 60% maximum oxygen intake. The recovery and rest periods were conducted while the subjects sat in chairs. Blood samples were taken every 15 minutes during the exercise and every 30 min-utes during the recovery period. Their respiratory gas and heart rates were monitored continu-ously throughout the trial.Summary of Results

The Repeated trial showed a greater amount of lipolysis (fat breakdown) than did the Single trial. This Repeated trial also had a pronounced increase in free fatty acids and glycerol (chemi-cal compounds that are released when stored fat is used) concentrations in the final 15 minutes of exercise, whereas these concentrations only progressively increased throughout the Single trial. Also, the second half of the Repeated trial showed a significantly greater epinephrine re-sponse while also having a rapid decrease in insulin concentration as a result of lower plasma glucose. This combination of high epinephrine and low insulin concentration may have also in-creased the lipolysis. There was also enhanced fat oxidation in the recovery period of the Re-peated trial than in the Single trial, but this result may be because the free fatty acids concen-tration was already high before the recovery period.Conclusions

The American College of Sports Medicine recommends moderate exercise for the duration of 45 to 60 minutes to ensure a sufficient amount of energy is depleted in obese individuals. This has caused a greater focus on extending exercise sessions in order to burn more fat. However, this study shows that this method may not be the most effective way to enhance fat metabo-

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lism, as splitting up a long bout of exercise with a rest period burns more fat than a continuous bout of exercise. This study could help with the practical application of implementing new exer-cise methods in order to better manage and control weight in individuals in the future. However, Goto and his team of researchers plan on conducting further studies in order to explore the re-sults in a variety of exercise durations as well as in different types of individuals.

Vital SignsPatterns: An Allergic Reaction May Be Tied to Geography

By ERIC NAGOURNEYAmericans who live in the South may be less susceptible to the life-threatening allergic reac-

tion known as anaphylaxis, a new study finds.Researchers have had a hard time pinning down a good number for how many people experi-

ence the reaction, which can be caused by bee stings or food allergies, among other things.So for this study, which appears in The Journal of Allergy and Clinical Immunology, they looked

at prescription patterns for EpiPens, small devices carried by many people with allergies that provide a shot of adrenalin to keep them breathing.

"The key point is the surprisingly large difference we found between the northern and south-ern U.S.A.,” said the lead author, Dr. Carlos A. Camargo Jr. of Harvard. "Why?”

One explanation may lie in the increased vitamin D people in the South get because of their sunnier location.

Many Americans, especially those in the Northeast, do not get enough vitamin D, the study said. Some research has found that higher levels of the vitamin may reduce childhood wheezing.

Still, the relationship is unclear. Alaska, they noted, did not have the high rate of EpiPen pre-scriptions. And there also appears to be a higher rate in the East than the West.

Personal HealthAvoiding the Dangers Down in the Garden

By JANE E. BRODY"Leaves of three, let them be.” No doubt you’ve heard this warning

about poison ivy, a weedy plant that each year causes more than 350,000 reported cases of human contact dermatitis, and probably many thousands more unreported cases.

Anecdotes from doctor’s offices indicate that this year is shaping up as a particularly nasty one for poison ivy, or Toxicodendron radi-cans, and evidence suggests that increased concentrations of carbon dioxide in the air have contributed to bumper crops with a more po-tent toxin.

But the rising risk of developing an extremely itchy, blistering rash from poison ivy is only one of the recent changes in human exposures to toxic or harmful plants.

Many homes and gardens play host to an increasing number of haz-ardous plants, and children are most often at risk. In 2003, according to an authoritative new book, poison control centers nationwide re-ceived more than 57,000 calls relating to exposure to potentially harmful plants, and 85 percent of them involved children under age 6. Most, however, were considered simply exposures; either no toxin was ingested or the amount consumed was too small to be harmful.

Stuart BradfordThe book, "Handbook of Poisonous and Injurious Plants” by Dr. Lewis S. Nelson, Dr. Richard D.

Shih and Michael J. Balick, was produced under the auspices of the New York Botanical Garden, where Dr. Balick is director of the Institute of Economic Botany. While its primary mission is to help health care professionals identify and treat plant-caused injuries, this lavishly illustrated book can be a helpful guide to ordinary people. It highlights hundreds of troublesome plants, providing photographs and written descriptions, common names, geographic distributions, toxic parts and toxins, effects on the body and information on medical management.

I was stunned to realize just how many of these potentially dangerous plants were in my own home and garden, including aloe, elephant’s ear, jade, peace lily (Spathiphyllum), philodendron and dumbcane (Dieffenbacchia), as well as foxglove (Digitalis purpurea), hellebore, vinca, rhodo-dendron and chrysanthemum. I count my blessings that none of my children or grandchildren tried to chomp on one of them.

Of course, plant-based poisons have an important role to play, especially in discouraging predators. And through the ages and into modern times, many have served important medicinal

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roles. Vinca, for example, was the original source of the anticancer drug vincristine, and foxglove gave us the valuable heart stimulant digitalis.

Deer, which have become a horrific horticultural nuisance in the Northeast, somehow know to avoid dining on several of the toxic plants, like vinca and foxglove, enabling gardeners to plant them in unfenced areas. If only our children were equally knowledgeable.Common Risks

Dr. Nelson, of New York University School of Medicine and the New York City Poison Control Center, said the problem often began with the fact that many toxic plants are beautiful and col-orful, prompting people to pick them to adorn their homes and gardens. But their very attractive-ness is what creates a hazard for small children, who may be tempted to put toxic berries, flow-ers or foliage in their mouths.

A second risk involves adults, who pick what they think are edible or medicinal plants but mis-takenly choose a toxic look-alike. In a recent incident cited by Dr. Nelson, a group of people picked what they thought were wild leeks, or ramps, cooked and ate them. What they really con-sumed was the cardiac toxin from young false hellebore. Fortunately, they survived the resulting heart rhythm disturbance.

Other cases have involved people who picked foxglove before it flowered, thinking it was a helpful herb that could be made into a medicinal tea. And sometimes herbal teas that should be safe are not because they were accidentally contaminated by a toxic plant. Thus, it is best to stick to well-known commercial brands packaged in the United States.

While ingested plant poisons are the most common hazard for small children, for adults and older children the usual sources of misery are plants that create problems on physical contact, like poison ivy. I asked Dr. Nelson what people do wrong after coming into contact with poison ivy, and the answer was simple: "They don’t wash their hands quickly and thoroughly enough. If you wash off the toxin with soap and water within 10 or 15 minutes, it’s unlikely to cause a reac-tion.”

This can be a particular problem for outdoor sports enthusiasts, landscapers and other out-door workers who may not notice their contact with the plant or may not have a means of quickly washing away the toxin, called urushiol. Even those who do wash may fail to scrub off the urushiol that gets under fingernails and then spread it to other parts of the body, Dr. Nelson said.

Over the course of hours or days, urushiol causes a slowly developing rash characterized by pain, itchiness, redness, swelling and blisters. Contrary to what many people think, the rash it-self does not spread. Rather, people spread the toxin around their bodies through scratching and contact with contaminated clothing.Other Problem Plants

Poison ivy is hardly the only source of urushiol, a class of toxins with varying potencies. It is also found in the skin of mangoes, as I sadly learned after eating a mango off the rind. It was still winter when I called my dermatologist and said, "If I didn’t know better, I’d say I had poison ivy of the mouth.” His immediate response: "You’ve been eating mangoes.”

Why, I wondered, had this not happened years ago? The answer was that after repeated expo-sures to urushiol that caused no reaction, I had become sensitized to the allergen and thereafter any contact with it could cause the same miserable reaction. Dr. Nelson said 85 percent of the population has the potential to develop sensitivity to urushiol. So if you think you can safely traipse through poison ivy, think again. Sooner or later you are likely to suffer as I did.

Treatment of a poison ivy rash typically involves relieving the itch with calamine lotion and taking an oral antihistamine or, in more serious cases, a corticosteroid.

Another common source of contact dermatitis involves the stinging nettle, a weedy plant that also seems to be thriving in our carbon dioxide-enriched environment, Dr. Balick said. These plants are a source of mechanical irritants. They have fragile hypodermic-like tubules containing a mixture of irritant chemicals that are injected when bare skin brushes against the plant and stinging hairs from the stems and leaves break the skin. Unlike poison ivy, the burning, itchy rash caused by stinging nettles is short-lived.

Still other problem plants contain chemical irritants, like capsaicin from chili peppers. This chemical is a mucous membrane irritant that causes the release of a substance that stimulates pain fibers and inflammation. This is especially painful when contaminated fingers transfer the chemical to the eyes or genitalia. To relieve the discomfort, it takes thorough and repeated washing, an analgesic to relieve the pain and, in some cases, anti-inflammatory medication.

Some plants, including agave, snow-on-the-mountain, crown-of-thorns, marsh marigold and buttercup, contain an irritant sap or latex, which can cause a chemical burn on the skin.

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Finally, there are plants that contain phototoxins — substances that increase the sensitivity of the skin to ultraviolet light and can result in a blistering sunburn. Among these are yarrow, rue and Queen Anne’s lace.

Study Finds Dietary Link to Risk of Eye DisorderBy NICHOLAS BAKALAR

Certain kinds of carbohydrates may play a role in the development of age-related macular de-generation, an incurable degenerative eye disease that is a leading cause of blindness in older adults. A new study has found that eating carbohydrate-rich food with a high glycemic index — a measure of a food’s potential to raise blood glucose levels — is associated with the development of the disorder.

The glycemic index is a measure of how fast carbohydrates are metabolized — the faster they are broken down into glucose, the higher the glycemic index. Simple carbohydrates, like those in cakes and cookies, cheese pizza, white bread or other foods sweetened with sugar or corn syrup, are quickly metabolized by the cells, while the complex carbohydrates in brown rice, barley and many other vegetables are broken down more slowly.

Heavy consumption of foods with a high glycemic index has been implicated in the develop-ment of diabetes, cardiovascular disease and some cancers, according to background informa-tion in the paper, which appears in the July issue of The American Journal of Clinical Nutrition.

The researchers examined 4,099 people ages 55 to 80 enrolled in a larger long-term study of eye health. Each participant had 20/32 vision in at least one eye, and the lens of the eye had to be clear enough to allow good photographs that could be used to diagnose macular degenera-tion.

None of the participants had diabetes. Using these criteria, the scientists had 8,125 eyes to analyze. They graded the severity of macular degeneration on a scale of one to five, adminis-tered food frequency questionnaires and calculated the dietary glycemic index, a number indi-cating the quantity of high-glycemic foods consumed, for each participant.

After controlling for age, sex, education level, body mass index, alcohol consumption and other variables, they found that the higher the dietary glycemic index, the more likely a person was to have macular degeneration. Those in the highest one-fifth of the dietary glycemic index had more than a 40 percent increased risk of significant macular degeneration than those in the lowest one-fifth. The amount of carbohydrate consumed was not correlated with disease, sug-gesting that it is only carbohydrates with a high glycemic index that cause the effect.

"Sugar is fuel for the cells, but too much is destructive,” said Allen Taylor, the senior author of the paper and chief of the Laboratory for Nutrition and Vision Research at Tufts University. "It is known from laboratory and animal studies that carbohydrates can damage the proteins in cells and affect their function. The sugars actually modify things, modify the proteins, and it’s the ac-cumulation of this modified stuff that is poisonous to cells.”

While the exact mechanism is unknown, the authors suggest that high glucose concentrations are harmful to the retina and the capillaries that supply the eyes, and that a diet of high glycemic index foods causes oxidative stress that increases inflammation.

It may also be that the sharp temporary increase in blood lipid levels that can follow consump-tion of simple carbohydrates plays a role in damaging the blood vessels.

Still, the researchers say, older age, lower education level and smoking are all more signifi-cant risk factors for age-related macular degeneration than diet. They also say that the study does not prove a cause-and-effect relationship between a high glycemic diet and macular degen-eration, that the study is based on observations made at a single point in time, and that long-term prospective studies will be needed before any firm conclusions can be drawn about the pre-cise relationship between diet and macular degeneration.

Dr. Taylor does not advocate a carbohydrate-free diet."I’m not an advocate of any extreme diet,” he said. "But self-control and limiting exposure to

simple sugars is not a bad idea.”He added: "People are eating more simple sugar than they used to, and reverting to a diet

that is more fruits and vegetables and less sweetened food would help. It doesn’t take a lot of change.”

Champion at Checkers That Cannot Lose to PeopleBy KENNETH CHANG

Checkers has been solved.16

A computer program named Chinook vanquished its human competitors at tournaments more than a decade ago. But now, in an article published Thursday on the Web site of the journal Sci-ence, the scientists at the University of Alberta who developed the program report that they have rigorously proved that Chinook, in a slightly improved version, cannot ever lose. Any oppo-nent, human or computer, no matter how skilled, can at best achieve a draw.

In essence, that reduces checkers to the level of tic-tac-toe, for which the ideal game-playing strategy has been codified into an immutable strategy. But checkers — or draughts, as it is known in Britain — is the most complex game that has been solved to date, with some 500 bil-lion billion possible board positions, compared with the 765 possibilities in tic-tac-toe.

Even with the advances in computers over the past two decades, it is still impossible, in prac-tical terms, to compute moves for all 500 billion billion board positions. So, the researchers took the usual starting position and looked only at the positions that occurred during play.

"It’s a computational proof,” said Jonathan Schaeffer, a professor of computer science at the University of Alberta who led the effort. "It’s certainly not a formal mathematical proof.” That means it is impossible for anyone to check every calculation the computer has performed.

Because of the vast calculations, the researchers had to keep painstaking track of the data. Miscopying a single bit — a glitch that did occur every few months — could render their result in-correct if not caught and corrected. When an error was caught, calculations had to be restarted from that point. A checkers hobbyist has independently verified major components of the proof with another computer program.

Dr. Schaeffer began his quest in 1989, aiming to write software that could compete with top checkers players in the world. In April, 18 years later, he and his colleagues finished their com-putations.

"From my point of view, thank God it’s over,” Dr. Schaeffer said.For an exercise in futility, anyone can play a game against the perfect Chinook at http://

www.cs.ualberta.ca/~chinook/play/. (It is limited to 24 games at a time.)The earlier incarnation of Chinook, relying on artificial intelligence techniques and the com-

bined computing power of many computers, placed second in the 1990 United States champi-onship behind Marion Tinsley, the world champion, who had won every tournament he had played in since 1950.

That achievement should have earned Chinook the right to challenge Dr. Tinsley, a professor of mathematics at Florida A&M University, for the world championship, but the American Check-ers Federation and the English Draughts Association refused to sanction a match. After much wrangling in the checkers world, Dr. Tinsley and Chinook battled for the man-versus-machine checkers title in 1992.

Dr. Tinsley won, 4 to 2 with 33 draws. Chinook’s two wins were only the sixth and seventh losses for Dr. Tinsley since 1950. In a rematch two years later, Dr. Tinsley withdrew after six draws, citing health reasons. Cancer was diagnosed, and Dr. Tinsley died seven months later.

Chinook easily triumphed over other human challengers, but the unfinished match against Dr. Tinsley left lingering doubt whether Chinook could claim to be the best of all time.

The new research proves that Chinook is invincible in traditional checkers. In most tournament play, however, a match now starts with three moves chosen at random. In solving the traditional game, the researchers have also solved 21 of the 156 three-move openings, leaving some hope for humans.

Alexander Moiseyev, the current world champion in what is known as three-move checkers, has never faced Chinook. He said he used computers to study and analyze games but did not play against them, and he readily conceded that people were no longer worthy competitors for computers.

"This time is over today,” he said. "It doesn’t bother me.” The next game Dr. Schaeffer hopes to conquer is poker, which is harder to solve, because players do not have complete knowledge of their opponents’ positions. Next week, his program, Polaris, will take on two professional poker players in Texas Hold ’Em for the $50,000 man-versus-machine world championship.

Soon, computers may not just be winning games, but taking people’s money, too.In the Trenches The Hospital Chaplain

Offering Comfort to the Sick and Blessings to Their HealersBy JAN HOFFMAN

At 1 p.m. on a weekday, the emergency department at St. Luke’s-Roosevelt Hospital in Upper Manhattan is in full cry, with bays crowded, patients on stretchers lining the hallways, and paramedics bringing in more sick people. Time for the Rev. Margaret A. Muncie to work the floor.

Not shy, this pastor with the clerical collar, the Ann Taylor blazer and the cheerful insistence of one whose own mother called her a steamroller. Among the first women ordained an Episco-

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pal priest and a self-described "Caucasian minority,” she’s an odd bird among the ethnically di-verse staff and especially the patients, most of them black or Latino. But she keeps pecking her head behind curtains, parting gatherings of worried family members, impervious to startled looks of suspicion.

"Hi, I’m Peggy Muncie, a hospital chaplain,” she says. "Would you like a visit?”She’s not there to thump. Deftly, she asks people how they’re feeling, then lets them vent

their pain and fear, their anxiety and frustration. She nods, a little pushy with her probing. She flags a nurse. "Can you direct a doctor toward that patient?” she whispers.

And always, at the end of a visit: "Would it be all right if I prayed with you?” The health care chaplain will touch a forehead, hold a hand and quietly pray worries to the Divine, speaking with inflections that, as needed, may be Pentecostal, Roman Catholic, Hindu, Jewish, Muslim. For the Baptist woman in Bed 7 whose anxieties are making her chest pain worse, the chaplain prays for calm to allow the medicine to work. Gradually, the patient’s breathing slows.

"My job is to be present to patients without judgment,” Chaplain Muncie says as she pumps a hand sanitizer, "and to help them find out what is meaningful to guide them through the stress of illness.”

Most health care facilities around the country work with clergy members. But their involve-ment varies widely. Some hospitals merely have a list of on-call pastors; others retain profes-sionally trained, board-certified health care chaplains, like Ms. Muncie, who is the only full-time cleric at St. Luke’s. (The hospital also has a rabbi and an imam part-time, and a supervisory pro-gram for theological students.)

These varying levels of commitment have less to do with differing philosophies about spiritual-ity and healing than with the bottom line. Insurance carriers do not reimburse for a chaplain’s salary.

"We’re a non-revenue-producing service, and in the economics of modern health care, that’s not a good place to be,” said the Rev. George F. Handzo, a vice president at the HealthCare Chaplaincy, a New York City organization that trains and places many chaplains.

"But there is a lot of indirect contribution to the mission of a hospital,” he added, "as well as to its margin: customer satisfaction, customer retention and goodwill in the community. From a revenue standpoint, that’s crucial.”

The chaplain is also expected to minister to the hospital staff. As Chaplain Muncie, 59, makes her way throughout St. Luke’s with a painstaking limp, she chats easily with doctors and nurses. She has sat with an intern who sobbed uncontrollably after pronouncing her first death and prayed with a ward clerk whose mother was in intensive care.

Every year, the chaplain performs a "Blessing of the Hands.” She wheels a cart adorned with a tablecloth, flowers, a bowl and an MP3 player. Surgeons, nurses, aides crowd around as she dips their hands in water, blessing their healing work.

Although intercessory praying for the sick has existed since the time of ancient shamans, the chaplain’s role now reflects the impact of modern technology on medicine. In her nearly five years at St. Luke’s, Ms. Muncie has helped mediate "do not resuscitate” decisions, organ dona-tions and bioethics disputes. After a visit, she puts the details in a patient’s chart.

Now she’s off to the intensive care unit, where many patients are intubated or comatose. Un-deterred, Chaplain Muncie goes room by room, soul-searching. From one bed, eyes watch drowsily but intently; from another, a gurgle: "Ahhh,” then, faintly, "mennnn.”

"They say the last sense to leave is a person’s hearing,” she says. "Well, I was a cheerleader and I can belt it out as loud as anyone.”

Spotting the chaplain, a woman jumps up from a bedside and embraces her. "Her husband is semicomatose,” Ms. Muncie explains later. "She is going to be a widow soon and she knows it. She trusts me now, so I can begin to ask the difficult questions: ‘Have you started to plan for your future?’ ”

One of Chaplain Muncie’s signature responsibilities is to stand with a patient’s family in the bleak early hours of death. The St. Luke’s chaplains are paged when a child or a staff member dies; if a death is traumatic; or in the event of a calamity like a fire. But though raw, savage grief has no vocabulary, Chaplain Muncie must give it voice, in a multitude of languages.

Recently, a woman from Mexico who spoke no English had to be told that her eldest son, 16, had been stabbed, and died just after surgery. As Chaplain Muncie helped deliver the news, she realized that the shocked woman was Pentecostal. So the chaplain held her, praying in the name of Jesus that Jesus would take her son to Heaven, that Jesus would give her strength to bear this.

A few weeks ago, the chaplain had to prepare a Jewish family for a morgue viewing of their fa-ther. "I know that in Judaism, you don’t say that the deceased goes to heaven,” she says now. "You talk about memory and legacy. This family was having a hard time getting closure. So I

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said: ‘What would your father be saying to help you get through this? What memory will you hold of him?’ And their mood changed.”

Her core belief about healing, says Chaplain Muncie, is animated by Psalm 121: "My help cometh from the Lord, who made heaven and earth” — spirit and body; faith and medicine. In 1996, doctors found a benign tumor in her brain the size of a tennis ball. The day after it was re-moved, she had a stroke. Her right side became paralyzed.

"I was frightened and mad,” she says, over a hasty salad. "But mostly I worried about my hus-band and daughters: What about them?”

So many people prayed for her. She was not allowed to abandon hope, not through the years of pain and physical therapy that reduced the paralysis to a lurching limp, thanks to a device she was recently fitted for — "an electronic doohickey, my own little miracle.”

She hitches up a pants-leg to show off the gadget, a neurostimulator. "I walk faster now,” she says. "I’m the kick-butt chaplain.” The experience deeply informs her ministry. "In Scripture it says, ‘Get up from your bed and walk, your faith has made you well,’ ” she continues.

" ‘Well’ doesn’t mean perfect. But wholeness and healing can happen, even when there is still brokenness on the outside,” she adds, tears spilling. "I’m more whole now than 12 years ago. But I still walk a little funny.”

After lunch she visits the acute-care floor, sitting at the bedside of an 87-year-old glaucoma patient.

"The hospital can be a busy, lonely place,” Chaplain Muncie says. "Who is there to walk this journey with you?”

The patient doesn’t hold back. Brittle-thin, blind, she lives in public housing with her grandson, 19. But he’s in serious trouble with the law. If she doesn’t kick him out in three days, she says, she’ll be evicted. The grandmother is heartsick about ejecting her grandson, yet terrified by looming homelessness.

The chaplain promises to alert a social worker. Immediately.The patient pleads: "Would you call my grandson and ask him to visit? He hasn’t been by.”The chaplain agrees. She gently mentions the parable of the Prodigal Son, of letting a profli-

gate young man go so that he may one day return, mature and penitent.Hands clasped, the women pray.Chaplain Muncie stands to leave. "Oh, you lifted my spirit!” the patient calls out. "Will you visit

me again?”Hormone spray could banish shyness

It was hailed as the "trust" hormone, then the "mind-reading" hormone. Now it seems oxy-tocin may also help people with social phobia to interact.

Markus Heinrichs at the University of Zurich, Switzerland, and colleagues are studying 70 peo-ple with generalised social phobia, characterised by overwhelming anxiety and self-conscious-ness in social situations.

Half an hour before undergoing standard cognitive behavioural therapy, which is designed to alter negative thoughts and behaviour, the patients were given a dose of oxytocin by nasal spray.

Preliminary results suggest oxytocin improved their readiness to interact in role-playing and their confidence in tackling social challenges outside the sessions, says Heinrichs, who will present his results at the World Congress of Neuroscience in Melbourne, Australia, this week.

In a separate study, Heinrichs and colleagues report that oxytocin reduces the response of the amygdala - a brain region involved in the fear response - to pictures of fearful, happy or angry faces (Biological Psychiatry, DOI: 10.1016/j.biopsych.2007.03.025). This may explain why patients are more ready to engage in social situations, Heinrichs believes.

Corn biofuel 'dangerously oversold' as green energy* 17:00 18 July 2007

* NewScientist.com news service* Phil McKenna

Ethanol fuel made from corn may be being "dangerously oversold" as a green energy solution according to a new review of biofuels.

The report concludes that the rapidly growing and heavily subsidised corn ethanol industry in the US will cause significant environmental damage without significantly reducing the country's dependence on fossil fuels.

"There are smarter solutions than rushing straight to corn-based ethanol," says Scott Cullen of the Network for New Energy Choices (NNEC) and a co-author of the study. "It's just one piece of a more complex puzzle."

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The report analyses hundreds of previous studies, and was compiled by the environmental ad-vocacy groups Food and Water Watch, NNEC and the Vermont Law School Institute for Energy and the Environment. The study was released as the US Congress debates key agriculture and energy laws that will determine biofuel policy for years to come.Rapid growth

Of the country's entire corn crop for 2007, 27% is earmarked for biofuels. That figure is up from 20% in 2006 and is beginning to put a squeeze on corn for food production.

Yet, even if all corn grown in the US was used for fuel, it would only offset 15% of the coun-try's gasoline use, according to the study. The same reduction could be achieved by a 3.5-mile-per-gallon increase in fuel efficiency standards for all cars and light trucks, according a federal figures cited in the report.

And using corn-derived ethanol does not necessarily even reduce greenhouse gas emissions. A number of recent studies have attempted to assess the total carbon footprint – from the field to the tailpipe – of the biofuel. Conclusions vary widely from being worse than gasoline to being about the same.

The report includes a recent study by the US Department of Energy (PDF), concluding that corn ethanol could reduce greenhouse gas emissions by 18% to 28%.

The same study, however, also notes that cellulosic ethanol could reduce emissions by 87% compared to gasoline. Cellulosic ethanol produces fuel from non-food sources such as prairie grasses and woody plants, but production is still under development.'Dead zones'

Further concerns are contained in a recent study from the World Resources Institute (PDF), cited in the report. It says the development of a corn-based ethanol market would only exacer-bate problems already associated with large-scale corn production.

Such problems include groundwater depletion, soil erosion, algae blooms, and the formation of "dead zones" in waterways inundated with pesticide and fertilizer runoff.

"Corn-based ethanol hasn't been pursued because this is the best solution, it's been because this has been what's been pushed the hardest," Cullen says. The recent survey notes that Archer Daniels Midland, the largest US ethanol producer, received $10 billion in federal subsidies be-tween 1980 and 1997.

But Brian Jennings, of the trade group, the American Coalition for Ethanol, disagrees. "We can release papers until we are blue in the face about what is theoretically going to be the best alter-native to reduce our dependence on fossil fuels and to reduce carbon emissions," he says. "But, from a practical standpoint, we have to start somewhere, and corn-based ethanol is the most vi-able alternative fuel on the planet today."

The current Farm Bill, which provides $16.5 billion in federal agricultural subsidies each year, will expire in September 2007. Proposals for a new Farm Bill are likely to include significant sub-sidies for the continued development of both corn-based ethanol and cellulosic ethanol.

The end of barroom brawlsStudy shows alcohol can reduce aggression

The link between alcohol and aggression is well known. What’s not so clear is just why drunks get belligerent. What is it about the brain-on-alcohol that makes fighting seem like a good idea" And do all intoxicated people get more aggressive" Or does it depend on the circumstances"

University of Kentucky psychologist Peter Giancola and his student Michelle Corman decided to explore these questions in the laboratory. One theory about alcohol and aggression is that drinking impairs the part of the brain involved in allocating our limited mental resources—specifi-cally attention and working memory. When we can only focus on a fraction of what’s going on around us, the theory holds, drunks narrow their social vision, concentrating myopically on provocative cues and ignoring things that might have a calming or inhibiting effect.

The scientists tested this idea on a group of young Kentucky men. Some of the men drank three to four screwdrivers before the experiment, while others stayed sober. Then they had them all compete against another person in a somewhat stressful game that required very quick responses. Every time they lost a round, they received a shock varying in intensity. Likewise, when they won a round they gave their opponent a shock. The idea was to see how alcohol af-fected the men’s belligerence, as measured by the kinds of shocks they chose to hand out.

But there was more to it. Giancola and Corman also deliberately manipulated some of the vol-unteers’ cognitive powers. They required them—some drinkers, some not—to simultaneously perform a difficult memory task. The idea was to see if they could distract those who were "un-der the influence” from their "hostile” situation. If they could tax their limited powers of concen-tration, perhaps they wouldn’t process the fact that someone was zapping them with electricity.

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And that’s exactly what happened. As reported in the July issue of Psychological Science, the drunks who had nothing to distract them were predictably mean, exhibiting aggression towards their adversaries. However, the drunks whose attention was focused elsewhere were actually less aggressive than the sober non-drinkers. This seems counterintuitive at first, but it’s really not: The sober men were cognitively intact, so they would naturally attend to both provocations and distractions in the room, resulting in some low level of aggression.

It appears that alcohol has the potential to both increase and decrease aggression, depending on where’s one’s attention is focused. The psychologists speculate that working memory is cru-cial not only to barroom behavior, but to all social behavior, because it provides the capacity for self-reflection and strategic planning. Activating working memory with salient, non-hostile, and health-promoting thoughts, in effect reduces the "cognitive space” available for inclinations to-wards violence.

Dam-busting 'megaflood' made Britain an island* 18:00 18 July 2007

* NewScientist.com news service* Paul Marks

When engineers digging the Channel Tunnel finally hacked through the chalk and shook hands in December 1990, it was the first time Britain and mainland Europe had been linked for hun-dreds of millennia. Now we know what separated those land masses in the first place: a megaflood.

Half a million years ago, Britain was connected to mainland Europe by a broad chalk ridge that spanned what we now call the Dover Strait. But somehow that ridge was destroyed, forever sep-arating England and France.

The cause was revealed by an ultrahigh-resolution sonar survey of a large chunk of the chan-nel's bedrock. It shows the Weald-Artois Ridge, as it is called, was breached and toppled by a monumental torrent that gushed from an overfilling glacial lake that the ridge had been damming on its northern side.

All that is left visible of the chalky ridge on the British side are the Seven Sisters and the white cliffs of Dover.

Sanjeev Gupta and Jenny Collier at Imperial College London, UK, say the sonar imagery shows deep valleys gouged into the channel's bedrock that could only have been made by vast vol-umes of fast-flowing water. "All the bedrock landforms we see are characteristic of a megaflood," Gupta says.'Overflowing bath'

The features they saw strongly resemble the "Channeled Scablands" – an area near Spokane in Washington State, US, where a megaflood spilled by a glacial lake called Lake Missoula is thought to have carved up the surface landscape 15,000 years ago.

So just how big was the ridge-busting tor-rent in the Channel? The Imperial team cal-culates that 1 million cubic metres of water per second flowed for several months to carve the seafloor valleys, some of which are up to 10 kilometres wide and 50 metres deep. The flow rate was 100 times the aver-age of the Mississippi river today, and 1000 times that of the Rhine, Gupta says.

The megaflood cut a 10-km-wide valley (Pink = shallow; Blue = deep), leaving the floor lined by erosional gouges cut into rock, as well as islands (Image: Nature)

According to the researchers, the flood took place sometime between 200,000 and 450,000 years ago. While the water of the megaflood would have flowed out to the Atlantic, later sea level rises in the interglacial period 125,000 years ago would have filled the valleys gouged by the flood to leave Britain an island.

The source of the megaflood was a vast glacial lake that occupied most of what is now the southern North Sea. Corralled by glaciers to the north and the ridge in the south, the lake was also being constantly fed by the Rhine and the Thames. "There was so much water coming in from the rivers and the glacial meltwater that it eventually had no place to go," says Gupta. "So it breached a hole in the ridge."

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"That lake was like a bath with the taps running," agrees Philip Gibbard, a geologist at the Uni-versity of Cambridge in the UK, who agrees with the analysis of the Imperial team. "The package of bedrock features they describe is very convincing."Sackcloth and ashes

However, Gupta and Collier are not the first to propose that a megaflood was responsible for making Britain an island. In 1985, marine geolo-gist Alec Smith of Bedford College in London used a lower resolution sonar survey to draw similar conclusions (Marine Geology, vol 64, p 65).

But the earlier sonar survey was only accurate to 10-metre resolution, leaving marine geologists sceptical because the depths of features gouged in the bedrock could not be reliably assessed. In addition, in the days before GPS, the positions of sonar soundings were only accurate to within 100 metres or so, further clouding the picture.

By contrast, the 2007 sonar survey was accu-rate to 10 centimetres, with differential GPS posi-tioning systems accurate to 5 metres. It was con-ducted by the UK Hydrographic Office to make safety-critical sub-sea digital maps for shipping.A large lake existed in the southern North Sea until about 450,000 years ago, dammed to

the south by the Weald-Artois rock ridge (Image: Nature)As a result, the valleys and gouged channels carved by the megaflood are clear to see, so the

theory was right all along, says Gupta. Gibbard admits he was one of the skeptics: "I have al-ready ordered my sackcloth and ashes." Journal reference: Nature (vol 448, p 342)

The BasicsJust a Bike Race, You Say? Think Again

By GINA KOLATAHow hard is the Tour de France?Ask Andy Hampsten, who rode the tour eight times and finished fourth twice. He says it was

the hardest thing he ever did as a cyclist, so hard that it is difficult for him to convey the stress and utter bone-tiredness that sets in during the three weeks of competition. At night, the cyclists could barely move.

"It hurt to walk, it hurt to lie in bed and do nothing,” Mr. Hampsten said. "When we were not racing, we were sitting down or lying down if we could. It’s funny to see these 20- and 30-year-old superathletes never standing up. Even when we would sit on the edge of a bed, we would slump down to a horizontal position as quickly as possible.”

This year’s tour, which began on July 7, will cover 2,205 miles over 23 days, including six days in the Alps and Pyrenees, before ending next Sunday in Paris. Only two days are set aside for rest.

Today, the race enters perhaps its toughest week, beginning with a 122-mile stage through the Pyrenees that includes two extremely steep climbs — a 10.5-mile ascent with an average gradient of 7.2 percent, and another 10-mile climb with an average incline of 7.9 percent.

Then the riders still in the race — 21 of the original 189 had dropped out as of Friday — will spend two more days climbing the steep slopes of the Pyrenees, ride three relatively flat stages and compete in a 34-mile individual time-trial.

Compare that with, say, running a marathon at an average pace of less than five minutes a mile. Elite runners have their own war stories and their races sound impossibly hard, too.

Hendrick Ramaala of South Africa, winner of New York City Marathon in 2004, spoke last year to mensracing.com about what it takes to win.

"The thing with the marathon is the distance,” he said. "It’s a long, long distance. I’ve learned about the marathon the hard way. I’ve experienced its pain. When the going gets hard, you still have to run hard. You have to give it everything. It took me a while to learn the pain of the marathon.”

Marathon running is so hard that elite runners often recuperate by taking two or three weeks off after a race with no running at all. And they only race in marathons twice a year.

Tour riders, by contrast, typically are racing again a month after the Tour and race as many as 100 times a year.

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But the question of which is harder — the Tour or a marathon — depends, scientists say, on what you mean by hard.

"Running is less of a test of pure cardiovascular strength and muscle strength,” says Robert Wolfe, a physiologist at the University of Arkansas for Medical Sciences. "Other factors come into play. In particular, the physical pounding of the legs on the road brings a kind of fatigue and muscle damage that lasts and persists.”

For pure energy expenditure, it is hard to match the Tour de France, whose riders consume as much as 8,000 to 9,000 calories a day.

By studying four racers as they rode in the 1985 Tour, Klaas Westerterp of Maastricht Univer-sity in the Netherlands concluded that their metabolic rates increased 4.3- to 5.3-fold. That sort of increase in metabolic rate, he added, is what birds reach when they fly and is thought to be a physiological limit.

David Gordon Wilson, an emeritus professor of mechanical engineering at the Massachusetts Institute of Technology and author of "Bicycling Science” (MIT Press, 2004), calculated that Tour riders generate 400 watts of power when they are riding up mountains or trying to break away from the pack. An average person riding a bicycle and working as hard as possible puts out 150 to 200 watts, he said.

There are no comparable wattage values for runners, Dr. Wilson said, because the two sports are so different. Cyclists use nearly all their energy to propel themselves forward. Runners, he said, "spend a lot of energy bouncing up and down.”

In any event, Dr. Wilson said, no ordinary human being could even dream of matching these top athletes.

"The difference between people who think they’re good athletes and really good athletes is fantastic,” he said.

Edward Coyle, director of the Human Performance Laboratory at the University of Texas at Austin, offered another perspective on the comparison between elite cyclists and elite runners.

"In the end, performance is where you give it your all and you are suffering as much as you can,” he said. "From the suffering point of view, cycling and running are about the same.”

Sailors may have cruised the Med 14,000 years agoBy Michele Kambas

NICOSIA (Reuters Life!) - Archaeologists in Cyprus have discovered what they believe could be the oldest evidence yet that organized groups of ancient mariners were plying the east Mediter-ranean, possibly as far back as 14,000 years ago.

The find, archaeologists told Reuters on Wednesday, could also suggest the island of Cyprus, tucked in the northeast corner of the Mediterranean and about 30 miles away from the closest land mass, may have been gradually populated about that time, and up to 2,000 years earlier than previously thought.

"This is a major breakthrough in terms of the study of early Cyprus archaeology and the ori-gins of seafaring in the Mediterranean," Pavlos Flourentzos, director of Cyprus's Department of Antiquities, told Reuters.

The discovery at a coastal site on the island's northwest has revealed chipped tools sub-merged in the sea and made with local stone which could be the earliest trace yet of human ac-tivity in Cyprus.

U.S. and Cypriot archaeologists conducting the research have known since 2004 that Cyprus was used by small groups of voyagers on hunting expeditions for pygmy elephants.

But the newly discovered expanse of the Aspros dig in the Akamas peninsula, which stretches into the sea, suggests the site held larger numbers of people, possibly for months.

"It shows that activity is much more organized than some isolated visit," said Tom Davis, di-rector of the Cyprus American Archaeological Research Institute (CAARI) in Nicosia.

Flourentzos and Davis said the new find told archaeologists nomads knew the island well enough to find tool material, suggesting they were repeat visitors.

Archaeologists say the first human settlements in Cyprus date from 10,000 BC and are lo-cated inland. Logically, the coastal settlements should be older, and in Aspros dig case where a good deal of it is now in the sea, possibly up to 2,000 years older.

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"We are trying to verify through carbon dating on bones in the area that this find is more an-cient, possibly another 2,000 years," said Flourentzos, who co-directed the research project with Albert J Ammerman, an archaeologist at Colgate University in Hamilton, New York.

Virtually nothing is known about Mediterranean mariners of the era. There is a widely held be-lief they never ventured into open seas because of limited navigational abilities.

"We are looking at repeated activity here, it is more than a handful of people. For the first time in the east Mediterranean we are talking about serious sea-voyaging," said Davis.

"This was not a case of one guy, or a family blown off course. This is a number of persons coming to Cyprus, these were conscious, repeated visits," Davis said.

Creeping oil might propel synthetic life* 18:01 19 July 2007

* NewScientist.com news service* Kurt Kleiner

Droplets of oil that propel themselves through water could someday allow so-called "artificial cells" to move around independently.

Italian and Japanese researchers created the self-propelled globules after examining a curious interaction between specially formulated droplets of oil and water, which resulted in the droplets slowly creeping in one direction.

A number of researchers around the world are trying to create artificial cells – simple cell-like structures that can carry hereditary information and pass it on to their offspring. (See Count-down to a synthentic lifeform.

The new research suggests that artificial cells might also be given the ability to move on their own. In principle, this might allow them to find nutrients and escape their own waste. The work was carried out by scientists at a company called ProtoLife in Venice, Italy, and at the University of Tokyo, where both teams are working towards creating an artificial cell.Surface tensions

Precisely how the oil droplets move across water is not entirely clear, but they seemed to be using a variant of the Marangoni effect, meaning differences in surface tension cause the droplet to move.

To test this theory, the researchers created droplets 1 millimetre in diameter by dropping ni-trobenzene oil containing oleic anhydride into alkaline water treated with a surfactant.

The oil droplets quickly developed small internal structures resembling bubbles, which fol-lowed an internal convection current. A chemical reaction causes the difference surface tension on each droplet, as oleic anhydride reacting with water forms oleic acid.

Each droplet has lower surface tension at one end. The bubbles move along the outer edge of a droplet towards this end, and then move through the centre to the other end. This process causes the droplet to move in the same direction as the bubbles moving through the centre of the bubbles (see video (Windows Media Player required).

It is not currently possible to control the direction of a droplet's movement. However, the re-searchers believe that altering the acidity on one side could help control the process.Engineering movement

"I certainly got excited when I first saw it," says Steen Rasmussen, a physicist at Los Alamos National Laboratory who also works on artificial cells. "I can imagine all kinds of things you could do with that. I'm sure many people like myself are pondering on how this could be utilised."

Jack Szostak, a molecular biologist at Harvard University, adds that the discovery might turn into a practical way to engineer motion into artificial cells.

"I think that the real significance of this work is that it should open up our thinking about new ways of doing just that," he told New Scientist. "After all, there may be many other unexpected solutions to the problem of cellular movement." Journal reference: Journal of the American Chemical Society (DOI: 10.1021/ja0706955)

Rise of dinosaurs in Late Triassic more gradual than once thoughtBerkeley -- Fossils discovered in the oft-painted arroyos of northern New Mexico show for the first time that dinosaurs and their non-dinosaur ancestors lived side by side for tens of millions of years, disproving the notion that dinosaurs rapidly replaced their supposedly outmoded prede-cessors.

The fossils were excavated from the Hayden Quarry at Ghost Ranch, an area made famous through the paintings of Georgia O'Keefe, by a team of paleontologists from the University of California, Berkeley, the American Museum of Natural History and The Field Museum. The finds, including fossil bones of a new dinosaur predecessor the researchers have named Dromomeron romeri, are described in a cover story in the July 20 issue of Science.

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"Up to now, paleontologists have thought that dinosaur precursors disappeared long before the dinosaurs appeared, that their ancestors probably were out-competed and replaced by di-nosaurs and didn't survive," said co-author Kevin Padian, professor of integrative biology at UC Berkeley and a curator in the campus's Museum of Paleontology. "Now, the evidence shows that they may have coexisted for 15 or 20 million years or more."

According to primary authors Randall Irmis and Sterling Nesbitt, graduate students, respec-tively, at UC Berkeley and at New York's American Museum, the new bones provide anatomical information that tells paleontologists about the evolution of dinosaur precursors, their transition into true dinosaurs and how dinosaurs diversified.

"Finding dinosaur precursors, or basal dinosauromorphs, together with dinosaurs tells us something about the pace of changeover," Irmis said. "If there was any competition between the precursors and dinosaurs, then it was a very prolonged competition."

An alternative hypothesis held that the sudden extinction of many animals in the Late Triassic period allowed dinosaurs to diversify and eventually populate the globe. Based on the new find-ings, however, "quite a few of the groups proposed to go extinct survived well into the Late Tri-assic," Irmis said.

Dinosaurs and many other animals, including mammals, lizards, crocodiles, turtles and frogs, arose in the Late Triassic, between 235 and 200 million years ago, but it was only in the Jurassic period 200-120 million years ago that dinosaurs dominated the planet and all their predecessors vanished. Fossils of Late Triassic dinosaurs are thus rare, and until 2003, when a creature called Silesaurus (SIGH leh SOAR us) was discovered in Poland, no dinosaur precursors had been found from the Late Triassic either.

At the Hayden Quarry, Irmis and Nesbitt found both early dinosaurs and dinosaur precursors, not to mention bones of crocodile ancestors, fish and amphibians, all dating between 220 and 210 million years ago. The Science re-port also details their discovery of the leg bones (femurs) of the car-nivorous Chindesaurus bryansmalli (SHIN dee SOAR us) and a close relative of the carnivorous Coelophysis (SEE low FIE sis), a well-known Triassic dinosaur. Both walked on two legs, reminiscent of the much later Velociraptor depicted in the 1993 film "Jurassic Park" as a cunning pack hunter.

The first dinosaur precursor found at the site was Dromomeron romeri (Dro MOE mer on RO mer eye), a creature related to a 235 million-year-old Argentinian middle Triassic precursor called Lager-peton (LAG err peh TON). Dromomeron was between three and five feet long, and possibly bipedal, the authors concluded. The other precursor was an unnamed, quadrupedal, beaked grazer about three times the size of Dromo-meron and similar to Silesaurus.

This scene depicts four dinosaurs and dinosaur precursors from the Hayden Quarry of northern New Mexico. Their coexistence indicates that the rise of dinosaurs was pro-

longed rather than sudden (Image: Donna Braginetz/Science)"Everyone thought that all the dinosaur precursors were little carnivorous, bipedal animals,"

Irmis said. "This Silesaurus-like creature still has the gestalt of a dinosaur, but to find a quadrapedal, herbivorous one was kind of unexpected."

Irmis noted that during the Late Triassic, the world's continents were a single supercontinent called Pangea, and the New Mexico site was then near the equator. Argentinian dinosaur precur-sors, on the other hand, come from a middle latitude site in Pangea. This could indicate a geo-graphic variation in survival of dinosaur precursors, or merely reflect the paucity of fossil finds, he said.

Ghost Ranch, near the town of Abiquiu, where artist O'Keefe lived, is known for its Triassic fos-sils excavated from the Chinle Formation. Many of them are kept in the Ruth Hall Museum of Pa-leontology at the headquarters of the ranch, which is operated as a retreat and conference cen-ter by the Presbyterian Church. UC Berkeley and American Museum scientists have visited the site at various times over the past 80 years, and collectors working for famed paleontologist Ed-ward Drinker Cope discovered the first Coelophysis dinosaur fossil there in 1881.

Hayden Quarry, however, is a relatively new excavation site started after a hiker discovered fossils there in 2002. After Ghost Ranch paleontologist Alex Downs showed some of these fossils to Irmis and Nesbitt in 2005, the two graduate students arranged to excavate at the site in the summer of 2006 and again earlier this summer, with assistance from members of the public en-rolled in a week-long summer paleontology seminar.

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"In the summer of 2005, we spent a day at the quarry and found half a dozen dinosaur bones, which is unheard of for Triassic deposits," Irmis said. "I have spent summers doing field work at the Petrified Forest National Park, which has rocks of the same age, and we were lucky to find half a dozen dinosaur bones in an entire season. So, we knew this was a really special site."

Altogether, they found 1,300 fossil specimens, including several complete bones. None of the remains described in the paper formed a complete skeleton. Most came from a 20- by 10-foot site. The research team continues to excavate at three sites in the quarry and is sifting through the debris for smaller fossils of mammals, lizards and fish.

"Randy and Sterling were clever to find all this stuff; these guys have just done terrific work," Padian said. Noting that Nesbitt obtained his B.S. in integrative biology from UC Berkeley, Padian added, "They are continuing the UC Berkeley tradition of discoveries from the Triassic, at the be-ginning of the dinosaurs."

New clue into how diet and exercise enhance longevityThe traditional prescriptions for a healthy life—sensible diet, exercise and weight control—ex-

tend life by reducing signaling through a specific pathway in the brain, according to Howard Hughes Medical Institute researchers who discovered the connection while studying long-lived mice.

They said their findings underscore the importance of maintaining a healthy lifestyle and may also offer promising research directions for understanding and treating diabetes and Alzheimer’s disease.

Howard Hughes Medical Institute investigator Morris F. White and his colleagues published their findings in the July 20, 2007, issue of the journal Science. Akiko Taguchi and Lynn Wartschow in White’s laboratory in the Division of Endocrinology at Children’s Hospital Boston and Harvard Medical School were co-authors of the research article.

In their experiments, the researchers sought to understand the role of the insulin-like signal-ing pathway in extending lifespan. This pathway governs growth and metabolic processes in cells throughout the body. The pathway is activated when insulin and insulin-like growth factor-1 switch on proteins inside the cell called insulin receptor substrates (Irs).

Other researchers had shown that reducing the activity of the pathway in roundworms and fruitflies extends lifespan. Despite those tantalizing clues, White said, "The idea that insulin re-duces lifespan is difficult to reconcile with decades of clinical practice and scientific investigation to treat diabetes.”

"In fact, based on our work on one of the insulin receptor substrates, Irs2, in liver and pancre-atic beta cells, we thought more Irs2 would be good for you,” said White. "It reduces the amount of insulin needed in the body to control blood glucose, and it promotes growth, survival and in-sulin secretion from pancreatic beta cells.

In earlier work, the researchers had found that knocking out both copies of the Irs2 gene in mice reduces brain growth and produces diabetes due to pancreatic beta cell failure. However, in the new study, when the researchers knocked out only one copy of the gene, they found the mice lived 18 percent longer than normal mice.

Because reducing insulin-like signaling in the neurons of roundworms and fruitflies extends their lifespan, the researchers decided to examine what would happen when they knocked out one or both copies of the Irs2 gene only in the brains of mice.

Mice lacking one copy of the Irs2 gene in brain cells also showed an 18 percent longer life-span, and the near complete deletion of brain Irs2 had a similar effect. "What’s more, the ani-mals lived longer, even though they had characteristics that should shorten their lives—such as being overweight and having higher insulin levels in the blood,” said White.

However, both sets of Irs2 knockout mice exhibited other characteristics that marked them as healthier, said White. They were more active as they aged, and their glucose metabolism resem-bled that of younger mice. The researchers also found that after eating, their brains showed higher levels of superoxide dismutase, an antioxidant enzyme that protects cells from damage by highly reactive chemicals called free radicals.

"Our findings put a mechanism behind what your mother told when you were growing up—eat a good diet and exercise, and it will keep you healthy,” said White. "Diet, exercise and lower weight keep your peripheral tissues sensitive to insulin. That reduces the amount and duration of insulin secretion needed to keep your glucose under control when you eat. Therefore, the brain is exposed to less insulin. Since insulin turns on Irs2 in the brain, that means lower Irs2 activity, which we’ve linked to longer lifespan in the mouse.”

White and his colleagues are planning their next studies to better understand how healthy ag-ing and lifespan are coordinated by Irs2 signaling pathways in the body and the brain. White

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speculated that the insulin-like signaling pathway in the brain might promote age-related brain diseases.

"We are beginning to appreciate that obesity, insulin resistance, and high blood insulin levels are connected to Alzheimer’s disease, Huntington’s disease, and dementias in general,” he said. "It might be that, in people who are genetically predisposed to these diseases, too much insulin overactivates Irs2 in the brain and accelerates disease progression. Thus, insulin resistance and higher insulin levels might be the environmental influences that promote these diseases,” he said.

New DepthsA Godsend for Darfur, or a Curse?

By LYDIA POLGREENDAKAR, Senegal

THE announcement by researchers at Boston University last week that a vast underground lake the size of Lake Erie had been discovered beneath the barren soil of northern Darfur, a blood-soaked but otherwise parched land racked by war for the past four years, was greeted by rapturous hopes. Could this, at last, bring deliverance from a cataclysmic conflict that has killed at least 200,000 people and pushed more than 2.5 million from their homes?

That hope is built upon an argu-ment, advanced by a United Na-tions report released last month and an opinion article in The Wash-ington Post by Ban Ki-moon, the United Nations secretary general, that environmental degradation and the symptoms of a warming planet are at the root of the Darfur crisis.

"There is a very strong link be-tween land degradation, desertifi-cation and conflict in Darfur,” said the United Nations Environmental Program report, which noted that rainfall in northern Darfur has decreased by a third over the last 80 years. "Exponential population growth and related environmental stress have created the conditions for conflicts to be triggered and sustained by political, tribal or ethnic differences,” the report said, adding that Darfur "can be considered a tragic example of the social breakdown that can result from ecological collapse.”

The idea that more water — unearthed through a thousand wells sunk into the underground lake — could neatly defuse the crisis is seductive. Messy African conflicts, from Congo to Liberia, from northern Uganda to Angola, have a way of defying all efforts to solve them. Instead, they seem to become hopelessly more complex as they drag on, year after agonizing year. A scien-tific explanation for the problem (environmental degradation) along with a tidy technological so-lution (irrigation) gratifies the modern humanitarian impulse.

But the history of Sudan, a grim chronicle of civil war, famine, coups and despotism, gives am-ple reason to be skeptical.

"Like all resources water can be used for good or ill,” said Alex de Waal, a scholar who has studied the impact of climate variation in Sudan and who witnessed the 1984-85 famine that is often cited as the beginning of the ecological crisis gripping Darfur. "It can be a blessing or also a curse. If the government acts true to form and tries to create some sort of oasis in the desert and control who settles there, that would simply be an extension of the crisis, not a solution.”

The droughts that gripped Sudan in the 1980s, and the migrations and other social changes they forced, have doubtless played a role in the conflict by increasing competition for water and land between farmers, who tend to be non-Arab, and herders, many of whom are Arabs. But an environmental catastrophe cannot become a violent cataclysm without a powerful human hand to guide it in that direction.

"These wider environmental factors don’t have impact in and of themselves” in terms of fo-menting conflict, Mr. de Waal said. "The question is how they are managed.”

In fact, while different regions and social groups suffer severely, Sudan as a whole has riches to spare, in oil, fertile soil, and even water. Indeed, history suggests that this newly discovered lake is just as likely to become a source of conflict as a solution to the bloodshed.

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Successive Sudanese governments and their colonial precursors have adopted agricultural policies that have almost inevitably led to conflict. They have favored large mechanized farms and complex irrigation schemes, controlled by the government and its allies, over the small, rain-fed farms that are the backbone of the rural economy in much of Sudan.

In eastern Sudan, where a rebellion has been brewing for years, the Beja people have nursed grievances since Britain and Egypt ruled Sudan jointly during the first half of the 20th century. Under their rule, irrigation programs for commercial farming deprived the Beja of their prime grazing land.

Post-colonial governments, which in the early years had the blessing of the World Bank and the International Monetary Fund, took vast tracts of land in the name of agricultural develop-ment, turning farmers who worked their own land into wage laborers for the state and its allies.

Some Sudanese have even been pushed off their land entirely. In the early 1990s the Nuba people were forced into "peace villages,” where they provided a steady supply of cheap, captive labor to mechanized farms. In other areas, including parts of Darfur, intensive mechanized farm-ing by the government and investors who were heedless to the need to protect the fertility of the land left large tracts barren.

A vast new agricultural scheme in a largely uninhabited swath of northern Darfur is more likely to fit into this destructive pattern than not, said John Prendergast, a founder of the Enough Project, an initiative of the Center for American Progress and the International Crisis Group to abolish genocide and mass atrocities.

"Climate change and the lack of rain are much less important than the land-use patterns pro-moted by the government of Sudan and the development policies of World Bank and I.M.F., which were focused on intensive agricultural expansion that really mined the soils and left a lot of land unusable,” said Mr. Prendergast, who has been studying Sudan for 20 years. "That was probably the principal impetus for a lot of intra-Darfur migration in the decades leading up to the conflict in Darfur.”

During those years, the government exploited tensions over water and land to achieve its own aims, putting down a rebellion among the non-Arab tribes, who rose up because they wanted a greater share of Sudan’s wealth and power. It armed tribal militias to fight the rebels, and these militias unleashed a tide of violence that ultimately would become, according to the Bush admin-istration and many others, the 21st century’s first genocide.

A report released last year by the Coalition for International Justice on the role that oil and mechanized farming have played in human rights abuses in Sudan concluded: "The predominant root of conflict in Sudan is the instability that results from the systemic abuse of the rural (and recently urbanized) poor at the hands of the economic and political elites of central Sudan.”

In this analysis, the heart of the Darfur conflict, as in all conflicts in Sudan, is the battle for control of resources and riches, but not between farmers and herders, northerners and southern-ers, Christians and Muslims, or Arabs and non-Arabs.

It is a conflict between those at the center of the country, the elites who have controlled Su-dan and its wealth for the past century and a half, and the desperately poor people who beg for scraps from the periphery.

Until that equation changes, many analysts argue, nothing else will.Mathematical model identifies genes which battle hepatitis C

Joint research by Dr. Leonid Brodsky, of the Institute of Evolution of the University of Haifa, and Dr. Milton Taylor, of Indiana University, led to the discovery of a mathematical method which can identify which genes in our bodies conduct the battle against the various viruses that attack us. In their research, they identified 37 genes out of 22,000 possible genes which fight the hep-atitis C virus.

"When we know which genes are responsible for fighting the viruses which attack our liver, we will be able to look for the medications which will activate these genes most favorably," said Dr. Brodsky. The team conducted clinical trials, supported by the Health National Institute of Dia-betes and Digestive and Kidney Diseases (NIDDK) of the US National Institutes of Health (NIH), which included 400 patients at eight different centers in the United States. The results will be published in the prestigious journal PLOS ONE.

The hepatitis C virus, found mostly among many patients who have had a blood transfusion or who share needles, attacks the liver and in extreme cases can cause cancer of the liver. At present, there is one well know medication, interferon, used to treat the virus; however, while some patients respond to the treatment with interferon, others do not. In this research, the clini-cal study was combined with the mathematical model developed by Dr. Brodsky. The study iden-tified 37 genes which are key for patient response to treatment.

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"In the specific case of hepatitis C, we have now isolated the genes that show which patients will respond to treatment. Until now, all patients received treatment for an extended period of time without knowing whether or not they would respond. In the future, we hope to find other medications that will be more effective in activating all of the 37 genes." summarized Dr. Brod-sky.

He further explained that this mathematical model is not limited to identifying the genes which fight viruses that attack the liver. It can also be applied further in the fields of medicine, biology and agriculture.Multi-gigabit wireless research could soon make wired computers and peripherals

obsoleteUntangling the office

New research at the Georgia Institute of Technology could soon make that tangle of wires un-der desks and in data centers a thing of the past.

Scientists at the Georgia Electronic Design Center (GEDC) at Georgia Tech are investigating the use of extremely high radio frequencies (RF) to achieve broad bandwidth and high data transmission rates over short distances.

Within three years, this "multi-gigabit wireless” approach could result in a bevy of personal area network (PAN) applications, including next generation home multimedia and wireless data connections able to transfer an entire DVD in seconds.

The research focuses on RF frequencies around 60 gigahertz (GHz), which are currently unli-censed -- free for anyone to use -- in the United States. GEDC researchers have already achieved wireless data-transfer rates of 15 gigabits per second (Gbps) at a distance of 1 meter, 10 Gbps at 2 meters and 5 Gbps at 5 meters.

"The goal here is to maximize data throughput to make possible a host of new wireless appli-cations for home and office connectivity,” said Prof. Joy Laskar, GEDC director and lead re-searcher on the project along with Stephane Pinel.

GEDC’s multi-gigabit wireless research is expected to lend itself to two major types of applica-tions, data and video, said Pinel, a GEDC research scientist.

Very high speed, peer-to-peer data connections could be just around the corner, he believes – available potentially in less than two years.

Devices such as external hard drives, laptop computers, MP-3 players, cell phones, commer-cial kiosks and others could transfer huge amounts of data in seconds. And data centers could install racks of servers without the customary jumble of wires.

"Our work represents a huge leap in available throughput,” Pinel said. "At 10 Gbps, you could download a DVD from a kiosk to your cell phone in five seconds, or you could quickly synchro-nize two laptops or two iPods.”

The input-output (I/O) system of current devices cannot approach such speeds.Moreover, Pinel said, users of multi-gigabit technology could wirelessly connect to any device

that currently uses Firewire or USB.Wireless high-definition video could also be a major application of this technology. Users could

keep a DVD player by their side while transmitting wirelessly to a screen 5 or 10 meters away.Currently, Pinel said, the biggest challenge is to further increase data rates and decrease the

already-low power consumption, with a goal to double current transmission rates by next year. The Georgia Tech team is seeking to preserve backward compatibility with the WiFi standard used in most wireless LANs today.

GEDC researchers are pursuing this goal by modifying the system architecture to increase in-telligence and effectiveness in the CMOS RF integrated circuits that transmit the data. The re-searchers are using advanced computer-aided design tools and testbed equipment to recalibrate system models and achieve the desired improvements in speed and functionality.

Investigators are placing special emphasis on implementing an RF concept called single-input-single-output (SISO) / multiple-input-multiple-output (MIMO), which enables ultra-high data throughput. At the same time, they seek to preserve backward compatibility with WLAN 802.11, the WiFi standard used in most wireless LANs today.

"We are pursuing a combination of system design and circuit design, employing both analog and digital techniques,” Pinel said. "It's definitely a very exciting mixed-signal problem that you have to solve.”

Even when sitting on a user’s desk, Pinel stresses, a multi-gigabit wireless system would present no health concerns. For one thing, the transmitted power is extremely low, in the vicinity of 10 milliwatts or less. For another, the 60 GHz frequency is stopped by human skin and cannot penetrate the body.

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The fact that multi-gigabit transmission is easily stopped enhances its practicality in an office or apartment setting, he adds. The signals will be blocked by any wall, preventing interference with neighbors’ wireless networks.

Currently there are no world standards in this bandwidth, explains GEDC Director Laskar. To address the situation, representatives of the ECMA International computer-standards organiza-tion met at GEDC in February to discuss a new international 60 GHz standard. The three-day gathering included representatives from the Electronics and Telecommunications Research Insti-tute of Korea, GEDC, Intel Corp., IBM Corp., Matsushita Electric Industrial Co. Ltd. (Panasonic), Newlans, Philips Semiconductors, Samsung Electronics Co. Ltd and Samsung Electro-Mechanics Co. Ltd. The ECMA International organization will meet again at GEDC in October to finalize the technical decisions.

The IEEE, the top international association of electrical engineers, is also weighing a 60 GHz standard, to be called 802.15.3C.

Laskar believes that additional applications will emerge as multi-gigabit technology becomes standardized and gains maturity.

"The promise of multi-gigabit wireless is tremendous,” he said. "The combination of short-range functionality and enormous bandwidth makes possible a whole range of consumer and business applications that promise great utility.”

Genetic variation may lower HIV load by 90%* 19:00 19 July 2007

* NewScientist.com news service* Roxanne Khamsi

A small genetic mutation in the section of human DNA that codes for immune proteins ap-pears able to reduce the amount of HIV in the body by an average of 90%, new research sug-gests. Scientists say the finding points to new ways in which vaccines might one day help boost immune protection against the virus.

Jacques Fellay at Duke University in Durham, North Carolina, US, and his teammates reviewed data collected from 30,000 HIV-infected individuals of European descent over a three-year pe-riod.

Within this group, the team identified almost 500 individuals who had a known date of infec-tion and a stable amount of HIV in their system – a measure known as 'viral load'.

Working with the molecular biologist David Goldstein, Fellay sought to understand how ge-netic differences among these 500 people could influence how well their bodies kept HIV under control.

Using DNA sequences determined from patient blood samples, the team worked to link spe-cific genetic mutations with differences in viral load. Their analysis revealed that one particular variant, in a part of the code that produces an immune protein called HLA-C, seems have a big impact on virus levels in the body.

People with this tiny sequence variation, dubbed rs9264942, appear to have up to 90% less virus in their systems than those who carry other polymorphisms.Better prognosis

Fellay says viral load is known to be the most important predictor for how quickly a person's infection will develop into full-blown AIDS. A patient whose virus levels initially settle at a lower number has a much better prognosis than someone whose infection stabilises at a higher amount, he explains.

The rs9264942mutation appears to help fight HIV infection by increasing the amount of HLA-C protein produced in the body. The protein helps alert the immune system to foreign particles, such as viruses, within cells. While HIV can disable similar proteins, known as HLA-A and HLA-B, it appears unable to do the same to HLA-C.

About 10% of Europeans appear to carry two copies of rs9264942, which leads to an average 90% viral load reduction. About 50% of Europeans carry one copy, which gives a 60% reduction. By comparison, less than 40% of people of African descent appear to carry a single copy of the polymorphism.

Fellay says that the new results from the study suggest that a vaccine to stimulate the action of HLA-C could help fight HIV.

Previous studies have found that certain genetic mutations, such the rare CCR5 mutation, can offer protection against the virus, but the new report is the first to show the impact of a variant affecting HLA-C.Journal reference: Science (DOI: 10.1126/science.1143767)U of M study identifies medication that helps people with obsessive-compulsive disorder

Next steps include investigating drug’s effect on smokers who want to quit30

MINNEAPOLIS / ST. PAUL (July 19, 2007) – Researchers at the University of Minnesota have found that a drug originally developed to fight tuberculosis may help people with obsessive-compulsive disor-der make more progress in therapy sessions.

Now they want to see if this drug could have a similar effect on people who want to quit smok-ing.

The research, led by Matt Kushner, Ph.D., was published in the online edition of Biological Psy-chiatry, and will appear in an upcoming print edition. Kushner’s collaborators include Suck Won Kim, M.D., and Christopher Donahue, Ph.D.

The drug, D-Cycloserine, is believed to help accelerate "extinction learning.” On a basic level, people associate positive or negative feelings with various cues from the external world. Behav-ioral therapy attempts to help the person disassociate problematic reactions that are either posi-tive (e.g., craving to use an addictive substance) or negative (e.g., fear of some catastrophic out-come) from the cues that trigger these feelings.

"This offers another therapeutic approach where we can attempt to manipulate the memory process and the brain’s reward/punishment system so people can learn healthier responses to various cues,” Kushner said.

For example, a person with OCD may have negative feelings before or after touching a door-knob. In psychotherapy, the person would work on disassociating the negative feeling with the external cue of seeing or touching a doorknob.

In this research project, investigators separated the people with OCD into two groups. One group received the drug and another received a placebo several hours before psychotherapy.

Kushner found that those who took the drug made progress in therapy more quickly and were less likely to quit therapy compared with the placebo group. The research subjects who took the drug reported feeling less distress or anxiety due to their obsessions or compulsions. The drug seemed to be most effective in the first few therapy sessions.

Over time, people in the placebo group could catch up in terms of therapy goals, but more study participants in the placebo group dropped out of therapy. "The dropout rate decreased dramatically,” Kushner said. "Typically about 20 to 30 percent of people with OCD drop out of therapy. Only 7 percent of people who took the D-Cycloserine dropped out.”

Kushner said that the drug will not work by itself; it must be done in conjunction with therapy to be effective.

Kushner and his team are now studying how the drug will effect smokers’ who want to quit, and they are seeking smokers to participate in a research study. "People who smoke have posi-tive feelings from the drug effects of nicotine associated with exposure to cues of smoking, such as seeing a pack of cigarettes, lighting up, or actually smoking,” Kushner said. "This research project investigates whether or not we will see a similar extinction learning effect in people who smoke.”

Study participants will be given nicotine-extracted cigarettes to smoke, and similar to the pre-vious study, one group will receive the drug, another the placebo, prior to therapy sessions. Par-ticipants will attend sessions once per week for four weeks, and they will be asked to smoke only the nicotine-extracted cigarettes in between the sessions.

Ice Age survivors in IcelandIce Age glaciers apparently didn't exterminate all life beneath them as previously thought

Many scientists believe that the ice ages exterminated all life on land and in freshwater in large parts of the Northern Hemisphere, especially on ocean islands such as Iceland. Scientists at Holar University College and the University of Iceland have challenged that belief, at least when looking at groundwater animals. They have discovered two species of groundwater am-phipods in Iceland that are the only animals species found solely in Iceland. "These finding can only be explained by these animals surviving glaciations in some kind of refugium under the glaciers,” says Bjarni K. Kristjánsson, the scientist who found the species.

In an article in the August issue of The American Natu-ralist, they put forward strong support for their theory. "Groundwater amphipods are poor at dispersal, and can not be transported with birds or humans,” says Jörundur Svavarsson. One of these new species falls within a new family of amphipods, which indicates that the species has been a long time in Iceland. "The time since the end of the last glaciation is not enough for a family to evolve,” says Svavarsson. Kristjansson and Svavarsson find it likely that the amphipod came to Iceland as early as 30-40 million

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years ago, when the volcanic island was being formed. "If our theory is right, we have discovered the oldest inhabitants of Iceland, and that can help us further understand how Iceland was formed,” says Kristjansson.Crymostygius thingvallensis, the only species in a recently described family of groundwa-

ter amphipods Crymostygidae. (photograph by Thorkell Heidarsson)Man with tiny brain shocks doctors

* 12:17 20 July 2007* NewScientist.com news service* New Scientist and Reuters

A man with an unusually tiny brain manages to live an entirely normal life despite his condi-tion, which was caused by a fluid build-up in his skull.

Scans of the 44-year-old man's brain showed that a huge fluid-filled chamber called a ventri-cle took up most of the room in his skull, leaving little more than a thin sheet of actual brain tis-sue (see image, right).

“It is hard for me [to say] exactly the percentage of reduction of the brain, since we did not use software to measure its volume. But visually, it is more than a 50% to 75% reduction,” says Lionel Feuillet, a neurologist at the Mediterranean University in Marseille, France.

Feuillet and his colleagues describe the case of this patient in The Lancet. He is a married fa-ther of two children, and works as a civil servant.Not retarded

The man went to a hospital after he had mild weakness in his left leg. When Feuillet's staff took his medical history, they learned that, as an infant, he had had a shunt inserted into his head to drain away hydrocephalus – water on the brain.

The shunt was removed when he was 14. But the researchers decided to check the condition of his brain using computed tomography (CT) scanning technology and another type of scan called magnetic resonance imaging (MRI). They were as-tonished to see "massive en-largement" of the lateral ven-tricles – usually tiny chambers that hold the cerebrospinal fluid that cushions the brain.

Intelligence tests showed the man had an IQ of 75, be-low the average score of 100 but not considered mentally retarded or disabled.

"The whole brain was re-duced – frontal, parietal, tem-poral and occipital lobes – on both left and right sides. These regions control motion, sensibility, language, vision, audition, and emotional and cognitive functions," Feuillet told New Scientist. The large black space shows the fluid that replaced much of the patient’s brain (left). For comparison, the images (right) show a typical brain with-

out any abnormalities (Images: Feuillet et al./The Lancet)Brain adaptation

The findings reveal "the brain is very plastic and can adapt to some brain damage occurring in the pre- and postnatal period when treated appropriately," he says.

"What I find amazing to this day is how the brain can deal with something which you think should not be compatible with life," comments Max Muenke, a paediatric brain defect specialist at the National Human Genome Research Institute in Bethesda, Maryland, US.

"If something happens very slowly over quite some time, maybe over decades, the different parts of the brain take up functions that would normally be done by the part that is pushed to the side," adds Muenke, who was not involved in the case. Journal reference: The Lancet (vol 370, p 262)

Hubble Space Telescope maps minerals on the moon32

Geologists have used the Hubble Space Telescope to study minerals on the moon. It might be one small step for them, but it's a giant leap towards building a lunar outpost.

Space scientists are keen to map the concentration of the titanium-dioxide-rich mineral ilmenite on the moon's surface, says Jim Garvin of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Oxygen production from TiO2-enhanced lunar soils could potentially make breathable oxygen and even oxidiser for rocket fuel."

UV images of the lunar surface show patterns that correlate with the concentration of TiO2 mea-sured in lunar samples collected by the Apollo missions, and so a map of the UV variations can be used to create a map of TiO2 abundance. However, Earth's atmosphere interferes with UV readings, so the team used Hubble to take UV images of a small area of the lunar surface that in-cluded the landing sites of the Apollo 15 and 17 spacecraft.

When the team compared the UV data with the TiO2 levels from the Apollo sampled, they found that low-lying basaltic soil has 6 to 8 per cent TiO2 by weight, while the highland soils contain only 2 per cent (Geophysical Research Letters, vol 34, p L13203). "Our well-calibrated UV images will act as a pathfinder for mapping by NASA's 2008 Lunar Reconnaissance Orbiter," says Garvin.

Taking the fossil out of fossil fuel20 July 2007 NewScientist.com news service

In the rolling farm country of central New York state, the cicadas buzz, the barn swallows swoop and the natural gas hisses. Covered from head to toe in a baggy blue safety suit, Jennifer McIntosh, a geochemist from the University of Arizona in Tucson, leans over a rusty wellhead as she extracts a sample. A moment later the hissing stops and a small silver canister, now full of gas, is unfastened and packed away, ready for the lab.

Over 1.5 billion cubic metres of natural gas were extracted in New York state last year, yet there remains a certain element of mystery about the stuff's origins. Conventional natural gas deposits are thermogenic, meaning they formed under intense heat and pressure hundreds of millions of years ago. McIntosh (pictured at work, below) is looking to see if the gas at this loca-tion is "biogenic", created during the past 18,000 years by methane-making microbes, or methanogens.

"Ultimately, the goal is to understand how microbes make methane and how to speed up that process," says McIntosh. "Biogenic gas is a huge energy resource that could potentially be re-newable on a human timescale."

Biogenic gas is a familiar by-product of methanogens that break down organic material in wet-lands, landfills and the human digestive system, among other places. What McIntosh is looking for is natural gas that made by methanogens devouring carbon locked in deposits of black shale. Normally, the briny groundwater often associated with this type of shale would inhibit methanogens. However, studies suggest the vast release of fresh water at the end of last ice age may have diluted the groundwater in some deposits enough for methanogens to gain a foothold.

In 1993, researchers with the United States Geological Survey (USGS) reported pockets of bio-genic gas across the US and predicted that 20 per cent of all known natural gas deposits world-wide were formed by microbes. Outside the US, deposits are now being tapped in Siberia, Aus-tralia, India and China, with additional accumulations believed to blanket continental shelves worldwide. "The distribution occurs from polar regions to the tropics, from sedimentary basins on land to offshore," says Peter Warwick, a USGS researcher.

This summer, McIntosh is sampling gas and water from wells across New York, Pennsylvania, Ohio, Kentucky and the Canadian province of Ontario to learn the full extent of biogenic gas de-posits in these areas. This in turn will provide a better sense of what environments methanogens can live in and aid the search for new gas deposits, as well as for potential sites where carbon dioxide can be sequestered after natural gas has been extracted. McIntosh also hopes to learn how the methanogens reach the shale in the first place, and whether they can be deliberately in-troduced into deposits that are not currently producing gas.

"Methane-producing bacteria could be deliberately introduced into deposits that aren't cur-rently producing gas""In the future we might be able to use large beds of coal and shale as nurs-eries for biogenic gas," says Warwick.

LUCA Technologies, based in Golden, Colorado, is already working on this idea and has close to a dozen related patents pending. Researchers at LUCA are currently testing ways to speed up methane production both in the laboratory and in naturally occurring "geobioreactors" deep un-

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derground. They are also developing strains of microbes to inject into shale, or spent coal and oil deposits to produce clean-burning natural gas.

"We're talking about gas formation over weeks or months instead of hundreds or thousands of years," says Mark Finkelstein, vice-president of biosciences at the company.

The idea has obvious appeal. Compared with burning coal, natural gas produces 44 per cent less carbon dioxide per unit of heat generated and far fewer toxic pollutants. Despite this, McIn-tosh acknowledges that the consumption of natural gas is a significant source of greenhouse emissions. "We need to be looking to alternative energy, but it's not going to happen overnight," she says. "It's still important to explore the potential of renewable natural gas." From issue 2613 of New Scientist magazine, 20 July 2007, page 17

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