Female Choice Key to Evolutionary Shift to Modern Family

It is a question that has puzzled evolutionary biologists for years: Why did we stop being promiscuous and decide to settle down to start families? Sergey Gavrilets, professor of ecology and evolutionary biology at the University of Tennessee, Knoxville, may have found the answer, and it lies in the power of female choice. The study reveals how females chose their mates played a critical role in human evolution by leading to monogamous relationships, which laid the foundation for the institution of the modern family. Using mathematical modeling, the associate director for scientific activities at the National Institute for Mathematical and Biological Synthesis (NIMBioS) at UT has discovered that the transformation may have occurred when...

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16th-Century Korean Mummy Provides Clue to Hepatitis B Virus Genetic Code

The discovery of a mummified Korean child with relatively preserved organs enabled an Israeli-South Korean scientific team to conduct a genetic analysis on a liver biopsy which revealed a unique hepatitis B virus (HBV) genotype C2 sequence common in Southeast Asia. The ancient Korean mummy of a child provides clues to the hepatitis B virus genome [Credit: Seoul National Univesity] Additional analysis of the ancient HBV genomes may be used as a model to study the evolution of chronic hepatitis B and help understand the spread of the virus, possibly from Africa to East-Asia. It also may shed further light on the migratory pathway of hepatitis B in the Far East from China and Japan to Korea as well as to other regions in Asia and Australia...

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Nanoparticles Seen as Artificial Atoms

In the growth of crystals, do nanoparticles act as "artificial atoms" forming molecular-type building blocks that can assemble into complex structures? This is the contention of a major but controversial theory to explain nanocrystal growth. A study by researchers at the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) may resolve the controversy and point the way to energy devices of the future. These are sequential color TEM images showing the growth of Pt3Fe nanorods over time, displayed as minutes:seconds. At the far right, twisty nanoparticle chains straighten and stretch into nanorods [Credit:  Haimei Zheng] Led by Haimei Zheng, a staff scientist in Berkeley Lab's Materials Sciences Division,...

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Drug Destroys Human Cancer Stem Cells but Not Healthy Ones

A team of scientists at McMaster University has discovered a drug, thioridazine, successfully kills cancer stem cells in the human while avoiding the toxic side-effects of conventional cancer treatments. "The unusual aspect of our finding is the way this human-ready drug actually kills cancer stem cells; by changing them into cells that are non-cancerous," said Mick Bhatia, the principal investigator for the study and scientific director of McMaster's Stem Cell and Cancer Research Institute in the Michael G. DeGroote School of Medicine. Unlike chemotherapy and radiation, thioridazine appears to have no effect on normal stem cells. The research, published May 24 in the science journal Cell, holds the promise of a new strategy and discovery...

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Stressed Men Are More Social

Freiburg researchers have refuted the common belief that stress always causes aggressive behavior. A team of researchers led by the psychologists and neuroscientists Prof. Markus Heinrichs and Dr. Bernadette von Dawans at the University of Freiburg, Germany, examined in a study how men react in stressful situations -- and have refuted a nearly 100-year-old doctrine with their results. According to this doctrine, humans and most animal species show the "fight-or-flight" response to stress. Only since the late 1990s have some scientists begun to argue that women show an alternate "tend-and-befriend" response to stress -- in other words, a protective ("tend") and friendship-offering ("befriend") reaction. Men, in contrast, were still assumed...

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Genetic Discovery Will Revolutionize Understanding Of Gene Expression

Over the past decade, research in the field of epigenetics has revealed that chemically modified bases are abundant components of the human genome and has forced us to abandon the notion we've had since high school genetics that DNA consists of only four bases. Over the past decade, research in the field of epigenetics has revealed that chemically modified bases are abundant components of the human genome and has forced us to abandon the notion we've had since high school genetics that DNA consists of only four bases. Now, researchers have made a discovery that once again forces us to rewrite our textbooks. This time, however, the findings pertain to RNA, which like DNA carries information about our genes and how they are expressed. The...

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Emotionally Intelligent People Are Less Good at Spotting Liars

People who rate themselves as having high emotional intelligence (EI) tend to overestimate their ability to detect deception in others. This is the finding of a paper published in the journal Legal and Criminological Psychology on18 May 2012. Professor Stephen Porter, director of the Centre for the Advancement of Psychological Science and Law at University of British Columbia, Canada, along with colleagues Dr. Leanne ten Brinke and Alysha Baker used a standard questionnaire to measure the EI of 116 participants. These participants were then asked to view 20 videos from around the world of people pleading for the safe return of a missing family member. In half the videos the person making the plea was responsible for the missing person's...

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How Exercise Affects the Brain

Exercise clears the mind. It gets the blood pumping and more oxygen is delivered to the brain. This is familiar territory, but Dartmouth's David Bucci thinks there is much more going on. Exercise clears the mind. It gets the blood pumping and more oxygen is delivered to the brain. This is familiar territory, but Dartmouth's David Bucci thinks there is much more going on [Credit: Web] "In the last several years there have been data suggesting that neurobiological changes are happening -- [there are] very brain-specific mechanisms at work here," says Bucci, an associate professor in the Department of Psychological and Brain Sciences. From his studies, Bucci and his collaborators have revealed important new findings: The effects of exercise...

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Are character traits determined genetically?

Genes play a greater role in forming character traits -- such as self-control, decision making or sociability -- than was previously thought, new research suggests. Genes play a greater role in forming character traits -- such as self-control, decision making or sociability -- than was previously thought, new research suggests [Credit: Web] A study of more than 800 sets of twins found that genetics were more influential in shaping key traits than a person's home environment and surroundings. Psychologists at the University of Edinburgh who carried out the study, say that genetically influenced characteristics could well be the key to how successful a person is in life. The study of twins in the US -- most aged 50 and over- used a series...

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In the Genes, but Which Ones? Studies That Linked Specific Genes to Intelligence Were Largely Wrong, Experts Say

For decades, scientists have understood that there is a genetic component to intelligence, but a new Harvard study has found both that most of the genes thought to be linked to the trait are probably not in fact related to it, and identifying intelligence's specific genetic roots may still be a long way off. For decades, scientists have understood that there is a genetic component to intelligence, but a new study has found both that most of the genes thought to be linked to the trait are probably not in fact related to it, and identifying intelligence's specific genetic roots may still be a long way off [Credit: Web] Led by David I. Laibson '88, the Robert I. Goldman Professor of Economics, and Christopher F. Chabris '88, Ph.D. '99, assistant...

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A walk in the park gives mental boost to people with depression

A walk in the park may have psychological benefits for people suffering from depression. In one of the first studies to examine the effect of nature walks on cognition and mood in people with major depression, researchers in Canada and the U.S. have found promising evidence that a walk in the park may provide some cognitive benefits. The study was led by Marc Berman, a post-doctoral fellow at Baycrest's Rotman Research Institute in Toronto, with partners from the University of Michigan and Stanford University. It is published online this week, ahead of print publication, in the Journal of Affective Disorders. "Our study showed that participants with clinical depression demonstrated improved memory performance after a walk in nature, compared...

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Powerful Function of Single Protein That Controls Neurotransmission Discovered

Scientists at Weill Cornell Medical College have discovered that the single protein -- alpha 2 delta -- exerts a spigot-like function, controlling the volume of neurotransmitters and other chemicals that flow between the synapses of brain neurons. The study, published online in Nature, shows how brain cells talk to each other through these signals, relaying thoughts, feelings and action, and this powerful molecule plays a crucial role in regulating effective communication. In the study, the investigators also suggest how the widely used pain drug Lyrica might work. The alpha 2 delta protein is the target of this drug and the new work suggests an approach to how other drugs could be developed that effectively twist particular neurotransmitter...

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DNA replication protein also has a role in mitosis, cancer

The foundation of biological inheritance is DNA replication – a tightly coordinated process in which DNA is simultaneously copied at hundreds of thousands of different sites across the genome. If that copying mechanism doesn't work as it should, the result could be cells with missing or extra genetic material, a hallmark of the genomic instability seen in most birth defects and cancers. Mitotic spindle-chromosome attachments, marked in green, become unstable (on the right) compared to normal (on the left) [Credit: Cook and Salmon labs, UNC School of Medicine] University of North Carolina School of Medicine scientists have discovered that a protein known as Cdt1, which is required for DNA replication, also plays an important role in a later...

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Scientists generate electricity from viruses

Imagine charging your phone as you walk, thanks to a paper-thin generator embedded in the sole of your shoe. This futuristic scenario is now a little closer to reality. Scientists from the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a way to generate power using harmless viruses that convert mechanical energy into electricity. The scientists tested their approach by creating a generator that produces enough current to operate a small liquid-crystal display. It works by tapping a finger on a postage stamp-sized electrode coated with specially engineered viruses. The viruses convert the force of the tap into an electric charge. Their generator is the first to produce electricity by harnessing...

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Gene therapy for hearing loss: Potential and limitations

Regenerating sensory hair cells, which produce electrical signals in response to vibrations within the inner ear, could form the basis for treating age- or trauma-related hearing loss. One way to do this could be with gene therapy that drives new sensory hair cells to grow. Researchers at Emory University School of Medicine have shown that introducing a gene called Atoh1 into the cochleae of young mice can induce the formation of extra sensory hair cells. Their results show the potential of a gene therapy approach, but also demonstrate its current limitations. The extra hair cells produce electrical signals like normal hair cells and connect with neurons. However, after the mice are two weeks old, which is before puberty, inducing Atoh1...

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New twist on ancient math problem could improve medicine, microelectronics

A hidden facet of a math problem that goes back to Sanskrit scrolls has just been exposed by nanotechnology researchers at the University of Michigan and the University of Connecticut. A hidden facet of a math problem that goes back to Sanskrit scrolls has just been exposed by nanotechnology researchers [Credit: © bivainis/Fotolia] It turns out we've been missing a version of the famous "packing problem," and its new guise could have implications for cancer treatment, secure wireless networks, microelectronics and demolitions, the researchers say. Called the "filling problem," it seeks the best way to cover the inside of an object with a particular shape, such as filling a triangle with discs of varying sizes. Unlike the traditional packing...

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Genes and Vascular Risk Modify Effects of Aging On Brain and Cognition

Efforts to understand how the aging process affects the brain and cognition have expanded beyond simply comparing younger and older adults. "Everybody ages differently. By looking at genetic variations and individual differences in markers of vascular health, we begin to understand that preventable factors may affect our chances for successful aging," said Wayne State University psychology doctoral student Andrew Bender, lead author of a study supported by the National Institute on Aging of the National Institutes of Health and now in press in the journal Neuropsychologia. The report, "Age-related Differences in Memory and Executive Functions in Healthy APOE ε4 Carriers: The Contribution of Individual Differences in Prefrontal Volumes...

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