Friday, January 27, 2012

Healthier ways to hibernate this winter


Healthier ways to hibernate this winterSometime in the weeks following New Year’s the novelty of winter begins to wear off. The once-invigorating brisk chill in the air just makes us want to head back to bed. According to the Gallup-Healthways Well-Being Index, physical activity drops off in these colder, darker late-fall and winter months every year. In 2011 the percentage of adults who reported exercising for at least 30 minutes 3 or more days a week fell to 49.8% in November, down more than 5% from the year’s high in July. Meanwhile, chilly temperatures make us want to double down when it comes to eating and indulge in hearty (and often fatty) comfort-food classics. In fact, who reported eating five or more servings of fruits and vegetables at least 4 days a week has been consistently lower in fall and winter months than in spring or summer between 2008 and 2011.  
While these are a few of the reasons we greet spring a few pounds heavier than we were in September, that doesn’t mean keeping in shape this winter is a lost cause. You can cave to some of your hunker-down instincts without sacrificing your health, as long as you hibernate strategically with these tips.

Saturday, December 17, 2011

Brighter Future for Solar Energy


The efficiency of conventional solar cells could be significantly increased, according to new research on the mechanisms of solar energy conversion led by chemist Xiaoyang Zhu at The University of Texas at Austin. Zhu and his team have discovered that it's possible to double the number of electrons harvested from one photon of sunlight using an organic plastic semiconductor material. "Plastic semiconductor solar cell production has great advantages, one of which is low cost," said Zhu, a professor of chemistry. "Combined with the vast capabilities for molecular design and synthesis, our discovery opens the door to an exciting new approach for solar energy conversion, leading to much higher efficiencies."  Zhu and his team published their groundbreaking discovery Dec. 16 inScienceThe maximum theoretical efficiency of the silicon solar cell in use today is approximately 31 percent, because much of the sun's energy hitting the cell is too high to be turned into usable electricity. That energy, in the form of "hot electrons," is instead lost as heat. Capturing hot electrons could potentially increase the efficiency of solar-to-electric power conversion to as high as 66 percent.

Zhu and his team previously demonstrated that those hot electrons could be captured using semiconductor nanocrystals. They published that research in Science in 2010, but Zhu says the actual implementation of a viable technology based on that research is very challenging.

Friday, December 16, 2011

Why Almost All Multicellular Organisms Begin Life as a Single Cell


Any multicellular animal, from a blue whale to a human being, poses a special difficulty for the theory of evolution. Most of the cells in its body will die without reproducing, and only a privileged few will pass their genes to the next generation.How could the extreme degree of cooperation multicellular existence requires ever evolve? Why aren't all creatures unicellular individualists determined to pass on their own genes? Joan Strassmann, PhD, and David Queller, PhD, a husband and wife team of evolutionary biologists at Washington University in St. Louis, provide an answer in the Dec. 16 issue of the journal Science. Experiments with amoebae that usually live as individuals but must also join with others to form multicellular bodies to complete their life cycles showed that cooperation depends on kinship.

If amoebae occur in well-mixed cosmopolitan groups, then cheaters will always be able to thrive by freeloading on their cooperative neighbors. But if groups derive from a single cell, cheaters will usually occur in all-cheater groups and will have no cooperators to exploit.
The only exceptions are brand new cheater mutants in all-cooperator groups, and these could pose a problem if the mutation rate is high enough and there are many cells in the group to mutate. In fact, the scientists calculated just how many times amoebae that arose from a single cell can safely divide before cooperation degenerates into a free-for-all.

Ability to Love Takes Root in Earliest Infancy


The ability to trust, love, and resolve conflict with loved ones starts in childhood -- way earlier than you may think. That is one message of a new review of the literature inCurrent Directions in Psychological Science, a journal published by the Association for Psychological Science."Your interpersonal experiences with your mother during the first 12 to 18 months of life predict your behavior in romantic relationships 20 years later," says psychologist Jeffry A. Simpson, the author, with University of Minnesota colleagues W. Andrew Collins and Jessica E. Salvatore. "Before you can remember, before you have language to describe it, and in ways you aren't aware of, implicit attitudes get encoded into the mind," about how you'll be treated or how worthy you are of love and affection.

While those attitudes can change with new relationships, introspection, and therapy, in times of stress old patterns often reassert themselves. The mistreated infant becomes the defensive arguer; the baby whose mom was attentive and supportive works through problems, secure in the goodwill of the other person.

Thursday, December 15, 2011

All It Takes Is a Smile

Does she or doesn't she . . .? Sexual cues are ambiguous, and confounding. We -- especially men -- often read them wrong. A new study hypothesizes that the men who get it wrong might be the ones that evolution has favored. "There are tons of studies showing that men think women are interested when they're not," says Williams College psychologist Carin Perilloux, who conducted the research with Judith A. Easton and David M. Buss of University of Texas at Austin. "Ours is the first to systematically examine individual differences." The findings will appear in an upcoming issue of Psychological Science, a journal published by the Association for Psychological Science.
The research involved 96 male 103 female undergraduates, who were put through a "speed-meeting" exercise -- talking for three minutes to each of five potential opposite-sex mates. Before the conversations, the participants rated themselves on their own attractiveness and were assessed for the level of their desire for a short-term sexual encounter. After each "meeting," they rated the partner on a number of measures, including physical attractiveness and sexual interest in the participant. The model had the advantage of testing the participants in multiple interactions.
The results: Men looking for a quick hookup were more likely to overestimate the women's desire for them. Men who thought they were hot also thought the women were hot for them -- but men who were actually attractive, by the women's ratings, did not make this mistake. The more attractive the woman was to the man, the more likely he was to overestimate her interest. And women tended to underestimate men's desire.

Monday, December 12, 2011

Botox Injected in Head ‘trigger Point’ Shown to Reduce Migraine Crises


Scientists at the University of Granada have confirmed that injecting a local anesthetic or botulinum toxin (botox) into certain points named "trigger points" of the pericraneal and neck muscles reduce migraine frequency among migraine sufferers. University of Granada researchers have identified the location of these trigger points -which activation results in migraine- and their relationship with the duration and severity of this condition. Headache is a universal experience. At present, there are more than 100 different types of headache and one of the most recurring ones is migraine, which affects approximately 10-12% of the population, being three times more common in women than in men. When migraine becomes chronic -occurring more than 15 days a month-, it can disrupt patients' daily life in a great degree.

This research study is one of the three studies that have been conducted by Juan Miguel García Leiva -a researcher at the University of Granada Institute for Neuroscience "Federico Oloriz" -- and coordinated by professor Elena Pita Calandre.

Sunday, December 11, 2011

Why Hair Turns Gray


A new study by researchers at NYU Langone Medical Center has shown that, for the first time, Wnt signaling, already known to control many biological processes, between hair follicles and melanocyte stem cells can dictate hair pigmentation.The study was published in the June 11, 2011 issue of the journal CellThe research was led by Mayumi Ito, PhD, assistant professor in the Ronald O. Pereleman Department of Dermatology at NYU Langone. "We have known for decades that hair follicle stem cells and pigment-producing melanocycte cells collaborate to produce colored hair, but the underlying reasons were unknown," said Dr. Ito. "We discovered Wnt signaling is essential for coordinated actions of these two stem cell lineages and critical for hair pigmentation." The study suggests the manipulation of Wnt signaling may be a novel strategy for targeting pigmentation such as graying hair. The research study also illustrates a model for tissue regeneration.