Our brains are more like birds' than we thought - 0 views
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For more than a century, neuroscientists believed that the brains of humans and other mammals differed from the brains of other animals, such as birds (and so were presumably better). Researchers have now found that a comparable region in the brains of chickens concerned with analyzing auditory inputs is constructed similarly to that of mammals.
Dogs: Kids in Fur Coats? -- ScienceNOW - 0 views
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Dog owners often compare their pets to toddlers; many even treat their pooches like kids. It's easy to label such comparisons sentimental. But a new study suggests that the owners are right. A team of scientists has discovered that dogs behave surprisingly like 10-month-old infants on a classic psychological test--though there is one important difference.
Making an optical switch by drawing lines in gold - 0 views
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"Basically, any computing device (or switch, or router) that is based on light requires a nonlinear interaction between different light beams, but light doesn't like to do nonlinear stuff. With current technology, you can get efficient nonlinear optical interactions, but the hardware is kind of bulky or very delicate. Not the sort of thing you want to put in a billion devices. What my friends in Barcelona have demonstrated is that it's possible to create a relatively efficient optical nonlinear interaction in a nano-structured metallic surface. "
Tally of Antarctic Sealife Sheds Light on Changing Climate - 0 views
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More than 6,000 different species living on the sea-floor have been identified so far and more than half of these are unique to the icy continent. A combination of long-term monitoring studies, newly gathered information on the marine life distribution and global ocean warming models, enable the scientists to identify Antarctica's marine "biodiversity hotspots". Researcher Griffiths describes how krill populations (the shrimp-like invertebrates eaten by penguins, whales and seals) are reducing as a result of a decrease in sea-ice cover. A much smaller crustacean (copepods) is dominating the area once occupied by them. This shifts the balance of the food web to favour predators, like jellyfish, that are not eaten by penguins and other Southern Ocean higher predators. Sea-ice reduction is also affecting penguins that breed on the ice.
We're so good at medical studies that most of them are wrong - 0 views
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Statistical validation of results, as Shaffer described it, simply involves testing the null hypothesis: that the pattern you detect in your data occurs at random. If you can reject the null hypothesis—and science and medicine have settled on rejecting it when there's only a five percent or less chance that it occurred at random—then you accept that your actual finding is significant. The problem now is that we're rapidly expanding our ability to do tests. Various speakers pointed to data sources as diverse as gene expression chips and the Sloan Digital Sky Survey, which provide tens of thousands of individual data points to analyze. At the same time, the growth of computing power has meant that we can ask many questions of these large data sets at once, and each one of these tests increases the prospects than an error will occur in a study; as Shaffer put it, "every decision increases your error prospects." She pointed out that dividing data into subgroups, which can often identify susceptible subpopulations, is also a decision, and increases the chances of a spurious error. Smaller populations are also more prone to random associations. In the end, Young noted, by the time you reach 61 tests, there's a 95 percent chance that you'll get a significant result at random. And, let's face it—researchers want to see a significant result, so there's a strong, unintentional bias towards trying different tests until something pops out. Young went on to describe a study, published in JAMA, that was a multiple testing train wreck: exposures to 275 chemicals were considered, 32 health outcomes were tracked, and 10 demographic variables were used as controls. That was about 8,800 different tests, and as many as 9 million ways of looking at the data once the demographics were considered.
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It's possible to get the mental equivalent of whiplash from the latest medical findings, as risk factors are identified one year and exonerated the next. According to a panel at the American Association for the Advancement of Science, this isn't a failure of medical research; it's a failure of statistics, and one that is becoming more common in fields ranging from genomics to astronomy. The problem is that our statistical tools for evaluating the probability of error haven't kept pace with our own successes, in the form of our ability to obtain massive data sets and perform multiple tests on them. Even given a low tolerance for error, the sheer number of tests performed ensures that some of them will produce erroneous results at random.
Naps May Improve Performance Later In The Day : NPR - 0 views
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"In the study, researchers took two groups of healthy young adults. Each group completed two learning sessions. The difference was that between the first and second sessions, one group got to take a 90-minute nap. The group that got the nap improved in their ability to learn by 10 percent, while the non-napping group did 10 percent worse."
Human cells exhibit foraging behavior like amoebae and bacteria - 0 views
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"As far as we can tell, this is the first time this type of behavior has been reported in cells that are part of a larger organism," says Peter T. Cummings, John R. Hall Professor of Chemical Engineering, who directed the study that is described in the March 10 issue of the Public Library of Science journal PLoS ONE. The discovery was the unanticipated result of a study the Cummings group conducted to test the hypothesis that the freedom with which different cancer cells move - a concept called motility - could be correlated with their aggressiveness: That is, the faster a given type of cancer cell can move through the body the more aggressive it is. "Our results refute that hypothesis—the correlation between motility and aggressiveness that we found among three different types of cancer cells was very weak," Cummings says. "In the process, however, we began noticing that the cell movements were unexpectedly complicated." Then the researchers' interest was piqued by a paper that appeared in the February 2008 issue of the journal Nature titled, "Scaling laws of marine predator search behaviour." The paper contained an analysis of the movements of a variety of radio-tagged marine predators, including sharks, sea turtles and penguins. The authors found that the predators used a foraging strategy very close to a specialized random walk pattern, called a Lévy walk, an optimal method for searching complex landscapes. At the end of the paper's abstract they wrote, "...Lévy-like behaviour seems to be widespread among diverse organisms, from microbes to humans, as a 'rule' that evolved in response to patchy resource distributions." This gave Cummings and his colleagues a new perspective on the cell movements that they were observing in the microscope. They adopted the basic assumption that when mammalian cells migrate they face problems, such as efficiently finding randomly distributed targets like nutrients and growth factors, that are analogous to those faced by single-celled organisms foraging for food. With this perspective in mind, Alka Potdar, now a post-doctoral fellow at Case Western Reserve University and the Cleveland Clinic, cultured cells from three human mammary epithelial cell lines on two-dimensional plastic plates and tracked the cell motions for two-hour periods in a "random migration" environment free of any directional chemical signals. Epithelial cells are found throughout the body lining organs and covering external surfaces. They move relatively slowly, at about a micron per minute which corresponds to two thousandths of an inch per hour. When Potdar carefully analyzed these cell movements, she found that they all followed the same pattern. However, it was not the Lévy walk that they expected, but a closely related search pattern called a bimodal correlated random walk (BCRW). This is a two-phase movement: a run phase in which the cell travels primarily in one direction and a re-orientation phase in which it stays in place and reorganizes itself internally to move in a new direction. In subsequent studies, currently in press, the researchers have found that several other cell types (social amoeba, neutrophils, fibrosarcoma) also follow the same pattern in random migration conditions. They have also found that the cells continue to follow this same basic pattern when a directional chemical signal is added, but the length of their runs are varied and the range of directions they follow are narrowed giving them a net movement in the direction indicated by the signal.
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When cells move about in the body, they follow a complex pattern similar to that which amoebae and bacteria use when searching for food, a team of Vanderbilt researchers have found. The discovery has a practical value for drug development: Incorporating this basic behavior into computer simulations of biological processes that involve cell migration, such as embryo development, bone remodeling, wound healing, infection and tumor growth, should improve the accuracy with which these models can predict the effectiveness of untested therapies for related disorders, the researchers say.
Technology Review: Mapping the Malicious Web - 0 views
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Now a researcher at Websense, a security firm based in San Diego, has developed a way to monitor such malicious activity automatically. Speaking at the RSA Security Conference in San Francisco last week, Stephan Chenette, a principal security researcher at Websense, detailed an experimental system that crawls the Web, identifying the source of content embedded in Web pages and determining whether any code on a site is acting maliciously. Chenette's software, called FireShark, creates a map of interconnected websites and highlights potentially malicious content. Every day, the software maps the connections between nearly a million websites and the servers that provide content to those sites. "When you graph multiple sites, you can see their communities of content," Chenette says. While some of the content hubs that connect different communities could be legitimate--such as the servers that provide ads to many different sites--other sources of content could indicate that an attacker is serving up malicious code, he says. According to a study published by Websense, online attackers' use of legitimate sites to spread malicious software has increased 225 percent over the past year.
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Over the past couple of years, cybercriminals have increasingly focused on finding ways to inject malicious code into legitimate websites. Typically they've done this by embedding code in an editable part of a page and using this code to serve up harmful content from another part of the Web. But this activity can be difficult to spot because websites also increasingly pull in legitimate content, such as ads, videos, or snippets of code, from outside sites.
More breaks from sitting are good for waistlines and hearts - 0 views
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ScienceDaily (Jan. 13, 2011) - It is becoming well accepted that, as well as too little exercise, too much sitting is bad for people's health. Now a new study has found that it is not just the length of time people spend sitting down that can make a difference, but also the number of breaks that they take while sitting at their desk or on their sofa. Plenty of breaks, even if they are as little as one minute, seem to be good for people's hearts and their waistlines.
Politics and eye movement: Liberals focus their attention on 'gaze cues' much different... - 0 views
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In a new study, researchers measured both liberals' and conservatives' reaction to "gaze cues" -- a person's tendency to shift attention in a direction consistent with another person's eye movements. Liberals responded strongly to the prompts, consistently moving their attention in the direction suggested to them by a face on a computer screen. Conservatives, on the other hand, did not
YouTube - Sam Harris SALT - 2 views
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December 9th, 02005 - Sam Harris"The View From The End Of The World"This is an audio only presentation. This talk took place in the Conference Center Golden Gate Room, San Francisco. Quote: With gentle demeanor and tight argument, Sam Harris carried an overflow audience into the core of one of the crucial issues of our time: What makes some religions lethal? How do they employ aggressive irrationality to justify threatening and controlling non-believers as well as believers? What should be our response? Harris began with Christianity. In the US, Christians use irrational arguments about a soul in the 150 cells of a 3-day old human embryo to block stem cell research that might alleviate the suffering of millions. In Africa, Catholic doctrine uses tortured logic to actively discourage the use of condoms in countries ravaged by AIDS. "This is genocidal stupidity," Harris said. Faith trumps rational argument. Common-sense ethical intuition is blinded by religious metaphysics. In the US, 22% of the population are CERTAIN that Jesus is coming back in the next 50 years, and another 22% think that it's likely. The good news of Christ's return, though, can only occur following desperately bad news. Mushroom clouds would be welcomed. "End time thinking," Harris said, "is fundamentally hostile to creating a sustainable future." Harris was particularly critical of religious moderates who give cover to the fundamentalists by not challenging them. The moderates say that all is justified because religion gives people meaning in their life. "But what would they say to a guy who believes there's a diamond the size of a refrigerator buried in his backyard? The guy digs out there every Sunday with his family, cherishing the meaningthe quest gives them." "I've read the books," Harris said. "God is not a moderate." The Bible gives strict instructions to kill various kinds of sinners, and their relatives, and on occasion their entire towns. Yet slavery is challenged nowhere in the New or
Which-way detector unlocks some mystery of the double-slit experiment - 1 views
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(PhysOrg.com) -- One of the greatest puzzles of the double-slit experiment - and quantum physics in general - is why electrons seem to act differently when being observed. While electrons traveling through a barrier with two slits create interference patterns when unobserved, these interference patterns disappear when scientists detect which slit each electron travels through. By designing a modified version of the double-slit experiment with a new "which-way" electron detector at one of the slits, a team of scientists from Italy has found a clue as to why electron behavior appears to change when being observed.
Dogs Decoded | Watch Free Documentary Online - 6 views
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Dogs Decoded reveals the science behind the remarkable bond between humans and their dogs and investigates new discoveries in genetics that are illuminating the origin of dogs - with surprising implications for the evolution of human culture. Other research is proving what dog lovers have suspected all along: Dogs have an uncanny ability to read and respond to human emotions. Humans, in turn, respond to dogs with the same hormone responsible for bonding mothers to their babies. How did this incredible relationship between humans and dogs come to be? And how can dogs, so closely related to fearsome wild wolves, behave so differently?
Binge eaters' dopamine levels spike at sight, smell of food - 1 views
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ScienceDaily (Feb. 28, 2011) - A brain imaging study at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory reveals a subtle difference between ordinary obese subjects and those who compulsively overeat, or binge: In binge eaters but not ordinary obese subjects, the mere sight or smell of favorite foods triggers a spike in dopamine -- a brain chemical linked to reward and motivation.
Quantum physics first: Physicists measure without distorting - 1 views
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With this new experiment, the researchers have succeeded for the first time in experimentally reconstructing full trajectories which provide a description of how light particles move through the two slits and form an interference pattern. Their technique builds on a new theory of weak measurement that was developed by Yakir Aharonov's group at Tel Aviv University. Howard Wiseman of Griffith University proposed that it might be possible to measure the direction a photon (particle of light) was moving, conditioned upon where the photon is found. By combining information about the photon's direction at many different points, one could construct its entire flow pattern ie. the trajectories it takes to a screen.
A Different Kind of Euphoria with a Legal Pot - 3 views
Looking for a legal pot that is totally intense without getting a hangover the next day is hard to find. But with Herbal Highs Online, we have found the right one. As we were browsing through the p...
New MRSA superbug discovered in cows' milk - health - 03 June 2011 - New Scientist - 1 views
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A new strain of MRSA has been identified in cows' milk and in people, but don't stop drinking milk - the bug is killed off in pasteurisation. However, the strain evades detection by standard tests used by some hospitals to screen for MRSA (methicillin-resistant Staphylococcus aureus), potentially putting people at risk. Laura Garcia Alvarez, then at the University of Cambridge, and colleagues were studying infections in British cows when they discovered antibiotic-resistant bacteria that they thought were MRSA. However, tests failed to identify the samples as any known strains of the superbug. Sequencing the mystery bacteria's genomes revealed a previously unknown strain of MRSA with a different version of a gene called MecA. The new strain was also identified in samples of human MRSA, and is now known to account for about 1 per cent of human MRSA cases.
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