science

For teenagers, friends play a big role in the decision to take that first drink. And by the 12th grade, more than 65 percent of teens have at least experimented with alcohol. But what parents do during the high school years can also influence whether teens go on to binge drink or abuse alcohol. Researchers at Brigham Young University have found that teenagers who grow up with parents who are either too strict or too indulgent tend to binge drink more than their peers.

For some adults, there is a tendency to go beyond the call of duty. Particularly, when they are faced with choosing to allow or not allow. Maybe the scientific explanation is to do or not to do. And the reaction isn't always the most appropriate but it is better to be safe than sorry. What is the scientific explanation for adults that don't react or react inappropriately even when it's involves saving a teenager? What is the scientific solution for those in the center of difficult situations, who are not strict or liberal? What does a mind do when it is present many times in a teenage situation and it is not the parent?

"When biologist Anthony Cashmore claims that the concept of free will is an illusion, he's not breaking any new ground. At least as far back as the ancient Greeks, people have wondered how humans seem to have the ability to make their own personal decisions in a manner lacking any causal component other than their desire to "will" something. But Cashmore, Professor of Biology at the University of Pennsylvania, says that many biologists today still cling to the idea of free will, and reject the idea that we are simply conscious machines, completely controlled by a combination of our chemistry and external environmental forces."

"(Medical Xpress) -- Researchers from Japan recently published a paper in PLoS One describing their successful growth and transplantation of new teeth created from the stem cells of mice."

ScienceDaily (July 11, 2011) - Researchers at Columbia Engineering School have built optical nanostructures that enable them to engineer the index of refraction and fully control light dispersion.

ScienceDaily (July 10, 2011) - University of Toronto researchers have derived inspiration from the photosynthetic apparatus in plants to engineer a new generation of nanomaterials that control and direct the energy absorbed from light.

Listen up, Facebook and Twitter groupies: how easily can social pressure affect your memory? Very easily, researchers at the Weizmann Institute and University College London have proved, and they think they even know what part of the brain is responsible. The participants conformed to the group on these "planted" responses, giving incorrect answers nearly 70% of the time. Volunteers watched a documentary film in small groups. Three days later, they returned to the lab individually to take a memory test, answering questions about the film. They were also asked how confident they were in their answers. They were later invited back to the lab to retake the test. This time, the subjects were also given supposed answers of the others in their film-viewing group (along with social-media-style photos) while being scanned in a functional MRI (fMRI) that revealed their brain activity. Is most of what you know false? Planted among these were false answers to questions the volunteers had previously answered correctly and confidently. The participants conformed to the group on these "planted" responses, giving incorrect answers nearly 70% of the time. To determine if their memory of the film had actually undergone a change, the researchers invited the subjects back to the lab later to take the memory test once again, telling them that the answers they had previously been fed were not those of their fellow film watchers, but random computer generations. Some of the responses reverted back to the original, correct ones, but get this: despite finding out the scientists messed with their minds, close to half of their responses remained erroneous, implying that the subjects were relying on false memories implanted in the earlier session. An analysis of the fMRI data showed a strong co-activation and connectivity between two brain areas: the hippocampus and the amygdala. Social reinforcement could act on the amygdala to persuade our brains to replace a strong memory wi

Fats in foods like potato chips and french fries make them nearly irresistible because they trigger natural marijuana-like chemicals in the body called endocannabinoids, researchers at the University of California, Irvine, have found. The researchers discovered that when rats tasted something fatty, cells in their upper gut started producing endocannabinoids, while sugars and proteins did not have this effect. How fats create, like, a buzz It starts on the tongue, where fats in food generate a signal that travels first to your brain, and then through a nerve bundle called the vagus to your intestines. There, the signal stimulates the production of endocannabinoids, which initiates a surge in cell signaling that prompts you to totally pig out - probably by initiating the release of digestive chemicals linked to hunger and satiety that compel us to eat more. And that leads to obesity, diabetes and cancer, the researchers said. But they suggest it might be possible to curb this process by obstructing endocannabinoid activity: for example, by using drugs that "clog" cannabinoid receptors. The trick: bypassing the brain to avoid creating anxiety and depression (which happens when endocannabinoid signaling is blocked in the brain). I'm guessing McDonald's won't be adding that drug to their fries. Ref.: Daniele Piomelli, et al., An endocannabinoid signal in the gut controls dietary fat intake, PNAS, 2011; in press

An immune-suppressing drug called rapamycin could possibly treat Hutchinson-Gilford progeria syndrome (HGPS), a rare genetic disease that causes premature aging, and advance biological understanding of the normal aging process, according to researchers from the National Human Genome Research Institute (NHGRI) at the National Institutes of Health, the University of Maryland and Massachusetts General Hospital. Progeria is a genetic disorder characterized by dramatic premature aging. "Progerin that causes progeria also accumulates, although in very small amounts, in normal aging," said Dimitri Krainc, M.D., Ph.D., associate professor of neurology at Harvard Medical School. "However, if rapamycin proves to have beneficial effects in lifespan in humans it is safe to assume that it will not be just because it may clear progerin from cells, but also because it clears other toxic products that accumulate during aging." Ref.: Francis S. Collins, et al., Rapamycin Reverses Cellular Phenotypes and Enhances Mutant Protein Clearance in Hutchinson-Gilford Progeria Syndrome Cells, Science, 2011; [DOI: 10.1126/scitranslmed.3002346]

ScienceDaily (July 5, 2011) - Have you heard the saying "You only remember what you want to remember"? Now there is evidence that it may well be correct. New research from Lund University in Sweden shows that we can train ourselves to forget things.

Scientists at the McEwen Centre for Regenerative Medicine and the Ontario Cancer Institute have isolated a human blood stem cell in its purest form: as a single stem cell capable of regenerating the entire blood system. "This discovery means we now have an increasingly detailed road map of the human blood development system, including the much sought after stem cell," says principal investigator John Dick, who holds a Canada Research Chair in Stem Cell Biology and is a Senior Scientist at the McEwen Centre for Regenerative Medicine and the Ontario Cancer Institute, University Health Network (UHN). "We have isolated a single cell that makes all arms of the blood system, which is key to maximizing the potential power of stem cells for use in more clinical applications. Stem cells are so rare that this is a little like finding a needle in a haystack," says Dr. Dick. Ref.: John E. Dick, Isolation of Single Human Hematopoietic Stem Cells Capable of Long-Term Multilineage Engraftment, Science, July 2011: Vol. 333 no. 6039 pp. 218-221 [DOI: 10.1126/science.1201219]

A new study of twins released online on Monday marked an important shift in thinking about the causes of autism.

ScienceDaily (June 28, 2011) - A recent study from scientists at the Salk Institute for Biological Studies suggests that a strawberry a day (or more accurately, 37 of them) could keep not just one doctor away, but an entire fleet of them, including the neurologist, the endocrinologist, and maybe even the oncologist.

ScienceDaily (June 27, 2011) - While the U.S. Food and Drug Administration notes "some concern" with the controversial chemical BPA, and many other countries, such as Japan and Canada, have considered BPA product bans, disagreement exists amongst scientists in this field on the effects of BPA in animals and humans. The latest research from the University of Missouri shows that BPA causes male deer mice to become demasculinized and behave more like females in their spatial navigational abilities, leading scientists to conclude that exposure to BPA during human development could be damaging to behavioral and cognitive traits that are unique to each sex and important in reproduction.

In 1967, Simon Kochen and Ernst Specker proved mathematically that even for a single quantum object, where entanglement is not possible, the values that you obtain when you measure its properties depend on the context. So the value of property A, say, depends on whether you chose to measure it with property B, or with property C. In other words, there is no reality independent of the choice of measurement. It wasn't until 2008, however, that Alexander Klyachko of Bilkent University in Ankara, Turkey, and colleagues devised a feasible test for this prediction. They calculated that if you repeatedly measured five different pairs of properties of a quantum particle that was in a superposition of three states, the results would differ for the quantum system compared with a classical system with hidden variables. That's because quantum properties are not fixed, but vary depending on the choice of measurements, which skews the statistics. "This was a very clever idea," says Anton Zeilinger of the Institute for Quantum Optics, Quantum Nanophysics and Quantum Information in Vienna, Austria. "The question was how to realise this in an experiment." Now he, Radek Lapkiewicz and colleagues have realised the idea experimentally. They used photons, each in a superposition in which they simultaneously took three paths. Then they repeated a sequence of five pairs of measurements on various properties of the photons, such as their polarisations, tens of thousands of times. A beautiful experiment They found that the resulting statistics could only be explained if the combination of properties that was tested was affecting the value of the property being measured. "There is no sense in assuming that what we do not measure about a system has [an independent] reality," Zeilinger concludes.

Playing sound effects both pleasant and awful, Julian Treasure shows how sound affects us in four significant ways. Listen carefully for a shocking fact about noisy open-plan offices. (Recorded at TEDGlobal University, July 2009, Oxford, UK. Duration: 5:47)

ScienceDaily (June 21, 2011) - An important milestone in the direct measurement of the magnetic moment of the proton and its anti-particle has been achieved.

Theodore Berger and his team at the USC Viterbi School of Engineering's Department of Biomedical Engineering have developed a neural prosthesis for rats that is able to restore their ability to form long-term memories after they had been pharmacologically blocked. In a dramatic demonstration, Berger blocked the ability to rats to form long-term memories by using pharmacological agents to disrupt the neural circuitry that communicates between two subregions of the hippocampus, CA1 and CA3, which interact to create long-term memory, prior research has shown. The rats were unable to remember which lever to pull to gain a reward, or could only remember for 5-10 seconds, when previously they could remember for a long period of time. The researchers then developed an artificial hippocampal system that could duplicate the pattern of interaction between CA3-CA1 interactions. Long-term memory capability returned to the pharmacologically blocked rats when the team activated the electronic device programmed to duplicate the memory-encoding function. The researchers went on to show that if a prosthetic device and its associated electrodes were implanted in animals with a normal, functioning hippocampus, the device could actually strengthen the memory being generated internally in the brain and enhance the memory capability of normal rats. "These integrated experimental modeling studies show for the first time that with sufficient information about the neural coding of memories, a neural prosthesis capable of real-time identification and manipulation of the encoding process can restore and even enhance cognitive mnemonic processes," says the paper. Next steps, according to Berger and Deadwyler, will be attempts to duplicate the rat results in primates (monkeys), with the aim of eventually creating prostheses that might help human victims of Alzheimer's disease, stroke, or injury recover function. Ref.: "A Cortical Neural Prosthesis for Restoring and Enhancing

It's not quite Cyclops, the sci-fi superhero from the X-Men franchise whose eyes produce destructive blasts of light, but for the first time a laser has been created using a biological cell. The human kidney cell that was used to make the laser survived the experience. In future such "living lasers" might be created inside live animals, which could potentially allow internal tissues to be imaged in unprecedented detail. It's not the first unconventional laser. Other attempts include lasers made of Jell-O and powered by nuclear reactors (see box below). But how do you go about giving a living cell this bizarre ability? Typically, a laser consists of two mirrors on either side of a gain medium - a material whose structural properties allow it to amplify light. A source of energy such as a flash tube or electrical discharge excites the atoms in the gain medium, releasing photons. Normally, these would shoot out in random directions, as in the broad beam of a flashlight, but a laser uses mirrors on either end of the gain medium to create a directed beam. As photons bounce back and forth between the mirrors, repeatedly passing through the gain medium, they stimulate other atoms to release photons of exactly the same wavelength, phase and direction. Eventually, a concentrated single-frequency beam of light erupts through one of the mirrors as laser light.

A new new brain imaging system that can identify a subject's simple thoughts may lead to clearer diagnoses for Alzheimer's disease or schizophrenia - as well as possibly paving the way for reading people's minds. Michael Greicius at Stanford University in California and colleagues used functional magnetic resonance imaging (fMRI) to identify patterns of brain activity associated with different mental states. He asked 14 volunteers to do one of four tasks: sing songs silently to themselves; recall the events of the day; count backwards in threes; or simply relax. Participants were given a 10-minute period during which they had to do this. For the rest of that time they were free to think about whatever they liked. The participants' brains were scanned for the entire 10 minutes, and the patterns of connectivity associated with each task were teased out by computer algorithms that compared scans from several volunteers doing the same task. This differs from previous experiments, in which the subjects were required to perform mental activities at specific times and the scans were then compared with brain activity when they were at rest. Greicius reasons his method encourages "natural" brain activity more like that which occurs in normal thought.