Domain: pnas.org
Stories and comments across the archive that link to pnas.org.
Stories · 206
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Stanford Bioengineers Create Rewritable Digital Data Storage In DNA
An anonymous reader writes "You don't hear too much about biological computing but in research published this week in the Proceedings of the National Academy of Sciences, scientists reveal they have devised the genetic equivalent of a binary digit (full article, freely available) — a 'bit' in data parlance. 'It took us three years and 750 tries to make it work, but we finally did it,' according to Jerome Bonnet, of research which describes, a method for repeatedly encoding, storing and erasing digital data within the DNA of living cells." -
Exposure to Wide Variety of Microbes May Reduce Allergies
sciencehabit writes "A new study reveals that people who grow up in more rural environments are less likely to develop allergies. The reason may be that environments rich with species harbor more friendly microbes, which colonize our bodies and protect against inflammatory disorders." From the article: "To test whether or not biodiversity does indeed create a shield against such conditions, the team investigated the microbial diversity of 118 teenagers. The study participants, who had lived in the same houses their whole lives, were chosen at random from a 100-by-150-kilometer block in eastern Finland. Some kids lived on rural, isolated farms, while others lived in larger towns. ... surveyed all of the types of plants growing around the adolescents' homes. The participants were part of a separate long-term allergy study, so the researchers took advantage of that data to investigate the connection between biodiversity and allergies. ... Whether there is just something special about Finland's native plants or whether this finding can be applied around the world is still an open question, Hanski says. 'Many research groups worldwide could easily attain these data from their study populations, and then we'd know how general these results might be.'" -
Diamonds Used To Increase Density, Performance of Phase-Change Memory
Lucas123 writes "Researchers at Johns Hopkins University have shown they can increase the density, performance and the durability of phase-change memory (PSM) by using diamonds to change the base alloy material. Instead of using the more typical method of applying heat to the alloy to change its state from amorphous to crystalline, thereby laying down bits in the material, the researchers used pressure from diamond-tipped tools. Using pressure versus heat allowed them to slow down the change in order to produce many varying states allowing more data to be stored on the alloy. 'This phase-change memory is more stable than the material used in current flash drives. It works 100 times faster and is rewritable millions of times,' said the study's lead author, Ming Xu, a doctoral student at the Whiting School of Engineering at Johns Hopkins University. 'Within about five years, it could also be used to replace hard drives in computers and give them more memory.'" -
Is Humanity Still Evolving?
sciencehabit writes "In a world where we've tamed our environment and largely protected ourselves from the vagaries of nature, we may think we're immune to the forces of natural selection. But a new study finds that the process that drives evolution was still shaping us as recently as the 19th century (abstract). 'The finding comes from an analysis of the birth, death, and marital records of 5923 people born between 1760 and 1849 in four farming or fishing villages in Finland. ... Natural selection was alive and well in all of the villages the researchers surveyed." -
Drug Turns Immune System Against All Tumor Types
sciencehabit writes, quoting an article in Science: "A single drug can shrink or cure human breast, ovary, colon, bladder, brain, liver, and prostate tumors that have been transplanted into mice, researchers have found. The treatment, an antibody that blocks a 'do not eat' signal normally displayed on tumor cells, coaxes the immune system to destroy the cancer cells." The abstract and full paper are freely available. It seems fairly promising: "In mice given human bladder cancer tumors, for example, 10 of 10 untreated mice had cancer that spread to their lymph nodes. Only one of 10 mice treated with anti-CD47 had a lymph node with signs of cancer. Moreover, the implanted tumor often got smaller after treatment — colon cancers transplanted into the mice shrank to less than one-third of their original size, on average. And in five mice with breast cancer tumors, anti-CD47 eliminated all signs of the cancer cells, and the animals remained cancer-free 4 months after the treatment stopped." -
Flatworms Defy Aging Through Cell Division Tricks
An anonymous reader writes "Researchers from The University of Nottingham have demonstrated how a species of flatworm overcomes the aging process to be potentially immortal. The discovery, published (abstract; full text PDF) in the Proceedings of the National Academy of Sciences, is part of a project funded by the Biotechnology and Biological Sciences Research Council and Medical Research Council and may shed light on the possibilities of alleviating aging and age-related characteristics in human cells." After finding the gene for telomerase synthesis in the worms, the researchers were able to observe that the worms "...dramatically increase the activity of this gene when they regenerate, allowing stem cells to maintain their telomeres as they divide to replace missing tissues." -
Flatworms Defy Aging Through Cell Division Tricks
An anonymous reader writes "Researchers from The University of Nottingham have demonstrated how a species of flatworm overcomes the aging process to be potentially immortal. The discovery, published (abstract; full text PDF) in the Proceedings of the National Academy of Sciences, is part of a project funded by the Biotechnology and Biological Sciences Research Council and Medical Research Council and may shed light on the possibilities of alleviating aging and age-related characteristics in human cells." After finding the gene for telomerase synthesis in the worms, the researchers were able to observe that the worms "...dramatically increase the activity of this gene when they regenerate, allowing stem cells to maintain their telomeres as they divide to replace missing tissues." -
Are Rich People Less Moral?
sciencehabit writes "New research suggests that the upper classes are more likely to behave dishonorably than those lower on the economic spectrum. The rich are more likely to cheat, steal, and even disobey traffic laws than those with less money and power (abstract). Curiously, in one experiment, Prius drivers also behaved badly, regardless of their wealth." -
Too Many Connections Weaken Networks
itwbennett writes "Conventional wisdom holds that more connections make networks more resilient, but a team of mathematicians at UC Davis have found that that is only true up to a point. The team built a model to determine the ideal number of cross-network connections. 'There are some benefits to opening connections to another network. When your network is under stress, the neighboring network can help you out. But in some cases, the neighboring network can be volatile and make your problems worse. There is a trade-off,' said researcher Charles Brummit. 'We are trying to measure this trade-off and find what amount of interdependence among different networks would minimize the risk of large, spreading failures.' Brummitt's team published its work (PDF) in the Proceedings of The National Academies of Science." -
Did Life Emerge In Ponds Rather Than Ocean Vents?
ananyo writes "The prevailing scientific view holds that life began in hydrothermal vents in the deep sea. But a controversial study (abstract) suggests that inland pools of condensed and cooled geothermal vapor have the ideal characteristics for the origin of life. The study hinges on the observation that the composition of the cytoplasm of modern cells is very different to that of seawater. On the other hand, the mix of metal ions in cytoplasm is (almost exclusively) found where where hot hydrothermal fluid brings the ions to the surface — places such as geysers and mud pots. There are a number of problems with the study, however — for instance, a lack of land 4 billion years ago would have made it difficult for life to start in such pools." -
Did Life Emerge In Ponds Rather Than Ocean Vents?
ananyo writes "The prevailing scientific view holds that life began in hydrothermal vents in the deep sea. But a controversial study (abstract) suggests that inland pools of condensed and cooled geothermal vapor have the ideal characteristics for the origin of life. The study hinges on the observation that the composition of the cytoplasm of modern cells is very different to that of seawater. On the other hand, the mix of metal ions in cytoplasm is (almost exclusively) found where where hot hydrothermal fluid brings the ions to the surface — places such as geysers and mud pots. There are a number of problems with the study, however — for instance, a lack of land 4 billion years ago would have made it difficult for life to start in such pools." -
Is Agriculture Sucking Fresh Water Dry?
sciencehabit writes "The average American uses enough water each year to fill an Olympic-sized swimming pool, and global agriculture consumes a whopping 92% of all fresh water used annually. Those are the conclusions of the most comprehensive analysis to date of global water use, which also finds that one-fifth of humankind's water consumption flows across international borders as 'virtual water' — the water needed to produce a commodity, such as meat or electronics, if the ultimate consumers were to make it themselves rather than outsource its growth or manufacture." -
Genetically Modifying Silk Worms For Super Silk
New submitter davidshenba sends this quote from the BBC: "U.S. researchers have created silkworms that are genetically modified to spin much stronger silk (abstract). In weight-for-weight terms, spider silk is stronger than steel. ... Researchers have been trying to reproduce such silk for decades. But it is unfeasible to 'farm' spiders for the commercial production of their silk because the arachnids don't produce enough of it — coupled with their proclivity for eating each other. Silk worms, however, are easy to farm and produce vast amounts of silk — but the material is fragile. Researchers have tried for years to get the best of both worlds — super-strong silk in industrial quantities — by transplanting genes from spiders into worms. But the resulting genetically modified worms have not produced enough spider silk until now. GM worms produced by a team led by Professor Don Jarvis of Wyoming University seem to be producing a composite of worm and spider silk in large amounts — which the researchers say is just as tough as spider silk." -
You Really Are What You Know
jd writes "There has been research for some time showing that London cab driver brains differ from other people's, with considerable enlargement of those areas dealing with spacial relationships and navigation. Follow-up work showed it wasn't simply a product of driving a lot (PDF). However, up until now it has been disputed as to whether the brain structure led people to become London cabbies or whether the brain structure changed as a result of their intensive training (which requires rote memorization of essentially the entire street map of one of the largest and least-organized cities in the world). Well, this latest study answers that. MRI scans before and after the training show that the regions of the brain substantially grow as a result of the training, and they're quite normal beforehand. The practical upshot of this research is that — even for adult brains, which aren't supposed to change much — what you learn structurally changes your brain. Significantly." -
Vaccine Developed Against Ebola
New submitter Lurching writes "Scientists have developed a vaccine that protects mice against a deadly form of the Ebola virus. First identified in 1976, Ebola fever kills more than 90% of the people it infects. The researchers say that this is the first Ebola vaccine to remain viable long-term and can therefore be successfully stockpiled. The results are reported in the journal Proceedings of National Academy of Sciences (abstract)." -
New 'Rubber Robot' Crawls Through Small Spaces With Inflatable Limbs
JoeRobe writes "Researchers at Harvard have developed a pneumatically-controlled rubber robot that combines undulation and quadrupedal 'crawling,' allowing it to maintain a low profile while moving. In a paper published in PNAS (abstract), they describe it as a 'soft robot, composed exclusively of soft materials (elastomeric polymers), which is inspired by animals (e.g., squid, starfish, worms) that do not have hard internal skeletons.' The robot is solely powered by relatively low pressure (10 psi), and controlled by 5 pneumatic actuators. The research was funded by DARPA." The paper is also available (not paywalled) from the researchers' project site (PDF), complete with more creepy images of the squidbot. -
Spotted Horses May Have Roamed Europe 25,000 Years Ago
sciencehabit writes with an excerpt from Science: "About 25,000 years ago, humans began painting a curious creature on the walls of European caves. Among the rhinos, wild cattle, and other animals, they sketched a white horse with black spots. Although such horses are popular breeds today, scientists didn't think they existed before humans domesticated the species about 5000 years ago. Now, a new study of prehistoric horse DNA concludes that spotted horses did indeed roam ancient Europe, suggesting that early artists may have been reproducing what they saw rather than creating imaginary creatures." -
Climate Change Driving War?
New submitter Stirling Newberry writes "You may have heard of The Great Moderation (PDF), which argues that business cycles have become less volatile over time, and the Green Revolution, a set of initiatives that led to increased global food production. These, it has been argued, have led to a marked decrease in war across the world. But not so fast, says a study in Science. It may well be that periods of war, past and present, can be linked to changes in climate: 'The most direct way in which extreme climate shifts influence human society is through agriculture, Zhang says; a falling supply of crops will drive up the price of gold and cause inflation. Similarly, epidemics can be exacerbated by famine. And when people are miserable, they are likely to become angry with their governments and each other, resulting in war. But golden ages rise out of these dark periods, the team argues. For instance, a 100-year cold period beginning in 1560 caused shortened crop growing seasons. The researchers found a causal linkage with a decline in average human height by nearly an inch during this period, and the century was rife with disease and conflict. But the world began to warm in 1650; when Charles II was crowned king of England in 1660, the coronation sparked the Enlightenment era in Europe.'" -
Self-Powered Microbial Fuel Cell Produces Hydrogen
donberryman writes "Researchers from Penn State have shown how microbial fuel cells can produce hydrogen without the need for an external source of electricity to power the process. It uses reverse-electrodialysis to capture energy from the difference in salinity between salt water and freshwater (abstract). Study co-author Bruce Logan explained the significance of the work: 'The breakthrough here is that we do not need to use an electrical power source anymore to provide a little energy into the system. All we need to do is add some fresh water and some salt water and some membranes, and the electrical potential that is there can provide that power.'" -
Gut Bacteria Exert Mind Control
sciencehabit writes "Hundreds of species of bacteria call the human gut their home. This gut 'microbiome' influences our physiology and health in ways that scientists are only beginning to understand. Now, a new study suggests that gut bacteria can even mess with the mind, altering brain chemistry and changing mood and behavior (abstract)." -
Transparent Lithium-Ion Battery Created
Med-trump writes "Stanford researchers say they have developed a transparent battery. Transparent futuristic gadgets have been a topic of science fiction and dream of engineers. The paper "Transparent lithium-ion batteries" was published in the July 25 edition of the journal Proceedings of the National Academy of Sciences. They used a grid-structured electrode, which is fabricated by a microfluidics-assisted method, such that the feature dimension in the electrode is below the resolution limit of human eyes, and, thus, the electrode appears transparent." -
Caltech Scientists Measure Dinosaur Body Temp
damn_registrars writes "Using rare isotope ratios, a geology team at CalTech has determined body temperatures of sauropod dinosaurs. Their work finds temperatures that are roughly in line with modern mammals for body temperature. However, as the authors point out, this does not on its own confirm dinosaurs to be entirely warm-blooded, as they may have kept these temperatures by sheer mass. The peer-reviewed paper is available online in PNAS. You can also get the article free through pubmed." -
Physical Pain and Emotional Pain Use Same Brain Networks
Antipater writes "To the brain, heartbreak and emotional torment are no different from having hot coffee spilled on your hand, reports CNN. They cite a recent study from Proceedings of the National Academy of Sciences in which 40 recently-dumped men and women underwent fMRI scans while having their arm burned or being shown a picture of their ex. The stimuli produced nearly identical brain reactions." -
Social Influence and the Wisdom of Crowd Effect
formfeed writes "A lot has been written lately on the crowd effect and the wisdom of crowds. But for those of us who are doubtful, the Proceedings of the National Academy of Science has published a study showing how masses can become dumber: social influence. While previous studies show how groups of people can come up with remarkably accurate results, it seems 'even mild social influence can undermine the wisdom of crowd effect in simple estimation tasks.' Social influence 'diminishes the diversity of the crowd without improvements of its collective error.' In short, crowd intelligence only works in cases where the opinion of others is hidden." -
High-Tech Gas Drilling Is Fouling Drinking Water
sciencehabit writes "Drilling for natural gas locked deep in a shale formation — a process known as fracking — has seriously contaminated shallow groundwater supplies beneath far northeastern Pennsylvania with flammable methane. That's the conclusion of a new study, published yesterday in the Proceedings of the National Academy of Sciences. The analysis gives few clues, however, to how pervasive such contamination might be across the wide areas of the Northeast United States, Texas, and other states where drilling for shale gas has taken off in recent years." -
Study of MMOG Proves Human Interaction Theory
An anonymous reader writes "A new study analyzing interactions among 300,000+ players in an online game universe, called Pardus, has for the first time provided large-scale evidence to prove an 80-year-old psychological theory called Structural Balance Theory. The research, published in PNAS, shows that individuals tend to avoid stress-causing relationships when they develop a society, resulting in more stable social networks." -
Scientists' Mouse Fight Club
An anonymous reader writes "To study how aggression, fighting, and winning change the brain, scientists set up a tournament of mice fights. They watched as the lab rodents took a break from their hum-drum existence and battled it out (however, the researchers broke the first rule of Fight Club by publishing a paper about their findings [abstract]). They found clear evidence of the 'winner effect,' in which a mouse that has just won a fight maintains elevated levels of testosterone and aggression, and is therefore more likely to win the next bout. Interestingly, the winner effect was strongest in mice that were fighting in their own cages — i.e., those that had home-field advantage." -
New Fossil Sheds Light On Lucy's Family Tree
I_am_sci_guy writes "A new fossil of an older, and presumably male, specimen of the same species as the famed Lucy indicates that A. afarensis may have walked and moved more like humans than was currently believed. The features of the unusually complete skeleton 'denote a nearly humanlike gait and ground-based lifestyle,' according to anthropologist Yohannes Haile-Selassie and his team, who found the specimen they call 'Big Man' and published preliminary results online today at PNAS (abstract; full text requires subscription). The article includes plenty of viewpoints dissenting from the conclusion that A. afarensis walked, and possibly ran, like modern humans do." -
Gene Therapy Restores Sight To Blind
An anonymous reader writes "Looks like we have found a cure for genetic blindness (clinical trial — abstract — paper [PDF] — ABC News video). This gene therapy treatment increases both cone and rod photoreceptor-based vision. These engineered viruses are implanted to do our bidding to restore vision. Clinical trials on 6 children and young people proved the therapy and didn't find any notable side effects." Any blind person, especially any adapted and competent one, who wants to gain the sense of sight would be well advised to study Oliver Sachs's classic piece "To See and Not See." -
Gene Therapy Restores Sight To Blind
An anonymous reader writes "Looks like we have found a cure for genetic blindness (clinical trial — abstract — paper [PDF] — ABC News video). This gene therapy treatment increases both cone and rod photoreceptor-based vision. These engineered viruses are implanted to do our bidding to restore vision. Clinical trials on 6 children and young people proved the therapy and didn't find any notable side effects." Any blind person, especially any adapted and competent one, who wants to gain the sense of sight would be well advised to study Oliver Sachs's classic piece "To See and Not See." -
Scientists Demonstrate Mammalian Tissue Regeneration
telomerewhythere writes "A quest that began over a decade ago with a chance observation has reached a milestone: the identification of a gene that may regulate regeneration in mammals. The absence of this single gene, called p21, confers a healing potential in mice long thought to have been lost through evolution and reserved for creatures like flatworms, sponges, and some species of salamander. 'Unlike typical mammals, which heal wounds by forming a scar, these mice begin by forming a blastema, a structure associated with rapid cell growth and de-differentiation as seen in amphibians. According to the Wistar researchers, the loss of p21 causes the cells of these mice to behave more like embryonic stem cells than adult mammalian cells, and their findings provide solid evidence to link tissue regeneration to the control of cell division. "Much like a newt that has lost a limb, these mice will replace missing or damaged tissue with healthy tissue that lacks any sign of scarring," said the project's lead scientist.' Here is the academic paper for those with PNAS access." -
Earliest "Writing" On 60,000-Year-Old Eggshells
New Scientist reports on research published in PNAS (abstract here) about what may be the earliest writing yet discovered, on eggshells dated to 60,000 years ago. "Since 1999, Pierre-Jean Texier of the University of Bordeaux, France, and his colleagues have uncovered 270 fragments of shell at the Diepkloof Rock Shelter in the Western Cape, South Africa. They show the same symbols are used over and over again, and the team say there are signs that the symbols evolved over 5,000 years. This long-term repetition is a hallmark of symbolic communication and a sign of modern human thinking, say the team. [Another researcher is quoted:] 'Judging from what we know about the evolution of art all over the world, there may have been many [written language] traditions that were born, lasted for some time, and then vanished. This may be one of them, most probably not the first and certainly not the last.'" -
Humans Nearly Went Extinct 1.2M Years Ago
Hugh Pickens writes "Scientific American has a story on researchers from the University of Utah who have calculated that 1.2 million years ago, at a time when our ancestors Homo erectus, H. ergaster, and archaic H. sapiens were spreading through Africa, Europe, and Asia, there were probably only about 18,500 individuals capable of breeding in all these species together (PNAS paper here). Pre-humans were an endangered species with a smaller population than today's gorillas and chimpanzees. Researchers scanned two completely sequenced modern human genomes for a type of mobile element called Alu sequences, then compared the nucleotides in these old regions with the overall diversity in the two genomes to estimate differences in effective population size, and thus genetic diversity between modern and early humans. Human geneticist Lynn Jorde says that the diminished genetic diversity one million years ago suggests human ancestors experienced a catastrophic event at that time as devastating as the Toba super-volcano in Indonesia that triggered a nuclear winter and is thought to have nearly annihilated humans 70,000 years ago." -
Fully Functional Bioengineered Tooth Grown In a Mouse
A couple of weeks back the Wall Street Journal reported on the first organ grown in vivo from stem cells — a tooth in the mouth of a mouse. Reader cdrpsab spotted the news on the MedGadget blog; the research had been reported earlier in the PNAS. From the WSJ: "The researchers at the Tokyo University of Science created a set of cells that contained genetic instructions to build a tooth, and then implanted this 'tooth germ' into the mouse's empty tooth socket. The tooth grew out of the socket and through the gums, as a natural tooth would. Once the engineered tooth matured, after 11 weeks, it had a similar shape, hardness and response to pain or stress as a natural tooth, and worked equally well for chewing. The researchers suggested that using similar techniques in humans could restore function to patients with organ failure." -
Daydreaming Is Really Complex Problem-Solving
beefsprocket writes "ScienceDaily reports that 'A new University of British Columbia study finds that our brains are much more active when we daydream than previously thought. The study, published in the Proceedings of the National Academy of Sciences (abstract), finds that activity in numerous brain regions increases when our minds wander. It also finds that brain areas associated with complex problem-solving — previously thought to go dormant when we daydream — are in fact highly active during these episodes. "Mind wandering is typically associated with negative things like laziness or inattentiveness," says lead author, Prof. Kalina Christoff, UBC Dept. of Psychology. "But this study shows our brains are very active when we daydream — much more active than when we focus on routine tasks."'" -
'Lab On a Chip' Made From Paper and Tape
An anonymous reader writes "Researchers at Harvard University have developed a microfluidic device using ordinary paper and tape. Squares of paper are layered and connected with adhesive tape, channeling liquid horizontally and vertically in a very small area. Each square of paper has been treated with photoresist material, which creates channels that funnel liquid into tiny wells containing certain proteins or antibodies. The fluid interacts with that area of the paper and turns the well a certain color. It can, for example, detect varying concentrations of glucose. Lead researcher George Whitesides says such paper 'lab on a chip' tests may lead to a cost-effective, portable, and accurate method for diagnosing diseases in countries lacking reliable health care. The research appears in the current issue of the Proceedings of the National Academies of Science." -
Couch Potato Gene Identified In Fruit Flies
Pickens writes "University of Pennsylvania biologists have discovered a mutation in fruit flies aptly named the 'couch potato' gene that allows them to simply chill out — entering a mild state of quasi-hibernation known as diapause, when winter arrives. 'It's not like they're bears sleeping in a cave,' says Paul Schmidt. 'They just look like they're a little bit more sluggish.' The couch potato gene, first discovered in the early 1990s, got its nickname because flies with mutations in the gene became really sluggish and behaved abnormally. Little is known about the underlying evolutionary genetic architecture, but in diapause, the slacking off is far less severe. The flies' bodily functions slow down, and they are better able to tolerate stress. The fruit fly gene may have implications for human health, as it can help biologists study the function of the nervous system and diseases such as epilepsy, refuting a recent statement by a political candidate that fruit fly research has 'little or nothing to do with the public good.'" -
Predicting Human Errors From Brain Activity
Hugh Pickens writes "Researchers report that brain activity can be used to predict the likelihood of someone making an error about six seconds in advance, with gradual changes starting as much as 30 seconds ahead of time. The team used an imaging machine to scan the brains of a group of volunteers who performed a task in the presence of distracting information. When performing correctly the volunteers' brains showed increased levels of activity in those parts associated with cognitive effort, as would be expected. However, these areas gradually became less active before errors were made and at the same time another set of regions in the brain became more active. These regions are part of a so-called "default mode network" and show increased use when people are resting or asleep [PDF]. While imaging machines are far too big and complex to be used in workplaces to monitor the brain activity of people engaged in important tasks, the team hopes to correlate errors to changes in electrical activity in the brain with electroencephalography (EEG), using electrodes placed on the scalp. If EEG features can be found that correspond to the change in brain activity, then a hat that gives warning of an imminent mistake might one day become reality. We've previously discussed similar studies of brain activity." -
Nanotube-Excreting Bacteria Allow Mass Production
Invisible Pink Unicorn writes "Engineers at the University of California, Riverside have found semiconducting nanotubes produced by living bacteria — a discovery that could help in the creation of a new generation of nanoelectronic devices. This is the first time nanotubes have been shown to be produced by biological rather than chemical means. In a process that is not yet fully understood, the bacterium secretes polysacarides that seem to produce the template for the arsenic-sulfide nanotubes. These nanotubes behave as metals with electrical and photoconductive properties useful in nanoelectronics. The article abstract is available from the Proceedings of the National Academy of Sciences." -
Fish Poison Makes Hot Feel Cold and Vice Versa
SoyChemist writes "Ciguatoxin causes bizarre neurological symptoms including temperature reversal, a burning sensation, and an imaginary feeling of loose teeth. It is produced by algae and accumulates in the fatty flesh of tropical fish. While traveling to the tropics, a man from England ate some bad seafood that contained the unusual poison. His story, and the tale of some unfortunate sailors of an earlier age who suffered the same affliction, appeared in the current issue of Practical Neurology and was summarized on the Wired Science Blog. Both the Wired blog and the peer-reviewed journal neglected to mention that the potent neurotoxin has been made from scratch by organic chemists." -
Pitch Perception Skewed By Modern Tuning
The feed deliverers us news of research suggesting that the use of A as the universal tuning frequency has made our ears less discerning of the notes immediately around it. Here's the abstract from PNAS describing research with people possessing the rare quality of "absolute pitch." -
New 'Stellarator' Design for Fusion Reactors
eldavojohn writes "The holy grail of fusion reactors has always seemed 'just a few years off' for many decades. But a recent design enhancement termed a 'Stellarator' may change all that. The point at which a fusion reactor crashes is when particles begin escaping due to disruptions in the plasma. A NYU team has discovered that coiling specific wires to form a magnetic field may contain the plasma. This may be a a viable way to create a plasma body with axial symmetry, and a far better chance of remaining stable. Like other forms of containment this does require energy itself, but could bring us closer to a stable fusion reactor. It may not be cold fusion or 'table top' fusion but it certainly is a step forward. The paper is up for peer review in the Proceedings of the National Academy of Sciences." -
Viking Mars Mission Might Have Missed Life
Johan Louwers writes "The Viking mars mission in 1976 might have missed signs of life due to not completely working analysis equipment. GC-MS on the Viking 1976 Mars missions did not detect organic molecules on the Martian surface, even those expected from meteorite bombardment. This result suggested that the Martian regolith might hold a potent oxidant that converts all organic molecules to carbon dioxide rapidly relative to the rate at which they arrive. This conclusion is influencing the design of Mars missions. We reexamine this conclusion in light of what is known about the oxidation of organic compounds generally and the nature of organics likely to come to Mars via meteorite." -
The World's Strongest Glue
missing_myself writes "Yahoo news reports the world's strongest glue is made by bacteria. "The adhesive can withstand an enormous amount of stress, equal to the force felt by a quarter with more than three cars piled on top of it." Time to get rid of the duct tape? " -
Words Affect Our Reality - On The Right
The Whorf hypothesis claims that one's native language influences perception and thought. Researchers at UC-Berkeley and U-Chicago reasoned that, since language is predominantly processed in the left hemisphere of the brain, any effect on perception should have an effect predominantly on the right visual field, which is also processed on the left. After comparing reaction times for hues of blue-green -- colors with distinct names in one language but not another -- they concluded, in a just-published paper, that the Whorf hypothesis holds for the right visual field, but not the left. -
Looking at Birds in a Whole New Spectrum
Shipud writes "Historically, bird species are classified using may different indicators, including plumage colors. Also, plumage variation has figured heavily in description of similarity between species. In a recent article in PNAS, Robert Bleiweiss shows that if we look in the ultra violet spectrum, birds species which seem similar, or are even considered related based on plumage colors, appear quite different. Quite a few theories regarding supposedly sympatric (sibling) species would have to be re-checked now. And yes, birds can see in the near UV spectrum, which is invisible to humans." -
Megafauna Extinction Due to Climate
jvchamary writes "Most biologists believe that Earth is currently undergoing its sixth mass extinction. The cause? Human activity, either directly (e.g. the Dodo) or indirectly (e.g. the Amazon rainforests). The disappearance 30,000-45,000 years ago of the Australian megafauna, large animals such as the marsupial lion, is often attributed to hunting by Aboriginal settlers. However, recent research in Proceedings of the National Academy of Sciences suggests that it was more likely a shift in climate, rather than hunting, that caused the over-sized organisms to die-out (via Nature and the BBC)." -
Using Computers To Weed Out Art Fakes
jackelfish writes "Reminiscent of handwriting analysis software used in the television series CSI, computers are now being used to evaluate the authenticity of works of art without an expert ever setting eyes on it. The technique identifies the artist by analyzing their characteristic brush or pen strokes from high resolution scans of previously authenticated works. Much like a fingerprint, these characteristics can then be compared to a work in question. The method, to be published in an upcoming issue of the Proceedings of the National Academy of Sciences promises to reduce the subjectivity of art assessments made by human experts." -
Gene Therapy Turns Slackers Into Workaholics
DrLudicrous writes "According to a recent Reuters article, scientists have been able to cause monkeys to stop procrastinating by blocking the development of a dopamine receptor in the brain. The net result- the monkeys turned into workaholics. An article has appeared in the online version of Nature. Apparently, monkeys, just like human beings, tend to slack off on tasks until the very last minute. They become quite adept at judging how long they have till they absolutely must complete these tasks. The original article appears in the Proceedings of the National Academy of Sciences of the United States of America. An additional blurb appears here courtesty of Science Blog." NIH has a press release. -
Gene Therapy Turns Slackers Into Workaholics
DrLudicrous writes "According to a recent Reuters article, scientists have been able to cause monkeys to stop procrastinating by blocking the development of a dopamine receptor in the brain. The net result- the monkeys turned into workaholics. An article has appeared in the online version of Nature. Apparently, monkeys, just like human beings, tend to slack off on tasks until the very last minute. They become quite adept at judging how long they have till they absolutely must complete these tasks. The original article appears in the Proceedings of the National Academy of Sciences of the United States of America. An additional blurb appears here courtesty of Science Blog." NIH has a press release.