News Articles

Older adults with low blood levels of vitamin D and high blood levels of a hormone secreted by the parathyroid glands may have a higher risk of depression, according to a report in Archives of General Psychiatry.
About 13 percent of older individuals have symptoms of depression, and other researchers have speculated that vitamin D may be linked to depression and other psychiatric illnesses, according to background information in the article.
“Underlying causes of vitamin D deficiency such as less sun exposure as a result of decreased outdoor activity, different housing or clothing habits and decreased vitamin intake may be secondary to depression, but depression may also be the consequence of poor vitamin D status,” the authors write. “Moreover, poor vitamin D status causes an increase in serum parathyroid hormone levels.” Overactive parathyroid glands are frequently accompanied by symptoms of depression that disappear after treatment of the condition.

People with shorter arms and legs may be at a higher risk for developing dementia later in life compared to people with longer arms and legs, according to a study published in the May 6, 2008, bonus issue of Neurology®, the medical journal of the American Academy of Neurology. Researchers say the association between short limbs and dementia risk may be due to poor nutrition in early life, which can affect limb growth.
Several studies have shown that early life environment plays an important role in susceptibility to chronic disease later in life.
“Body measures such as knee height and arm span are often used as biological indicators of early life deficits, such as a lack of nutrients,” said Tina L. Huang, PhD, who was with Johns Hopkins University in Baltimore, MD, when the study started. Huang is now with the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston, MA. “Because the development of the brain region most severely affected by Alzheimer’s disease coincides with the greatest change in limb length, we thought it was possible that men and women with shorter limbs could be at greater risk for developing dementia and Alzheimer’s disease.”

A new study by Rhode Island Hospital and Brown University researchers reports that fewer than half the patients previously diagnosed with bipolar disorder received a diagnosis of bipolar disorder based on a comprehensive, psychiatric diagnostic interview--the Structured Clinical Interview for DSM-IV (SCID).
The study concludes that while recent reports indicate that there is a problem with underdiagnosis of bipolar disorder, an equal if not greater problem exists with overdiagnosis. The study was published online by the Journal of Clinical Psychiatry. Principle investigator Mark Zimmerman, M.D., will present the findings at the annual meeting of the American Psychiatric Association on Wednesday, May 7.

For the first time, physicists have come up with a scheme that would allow a quantum mechanical expert to win every time in a con game with a victim who only knows about classical physics. Prior quantum cons have typically been vulnerable to simple countermeasures.
A pair of physicists at Tel-Aviv University in Israel came up with the quantum cheat by imagining two people betting on the location of a particle hidden among a set of boxes. In the game, a quantum mechanical con artist named Alice turns away as her classical victim, Bob, is allowed to look inside one of two boxes sitting on a table to see if there is a particle inside. He then closes the box and Alice guesses whether or not Bob found anything in the box he chose.
If she guesses correctly, she wins Bob's money, if not, she pays him.

As many parents know, it's often easier to keep your kids under control by exerting less authority rather than more. A child who fidgets uncontrollably in a confining booster seat, for example, may be perfectly content on a plain old chair. A team of physicists at the Universitat de Barcelona has found that the same is true in controlling the movement of particles suspended in liquids. What's more, they speculate that many microscopic systems, macroscopic ecosystems, and human social systems may respond to a gentle touch for the very same mathematical reasons.
In order to test their hypothesis that heavy handedness can lead to loss of control, the researchers used optical tweezers to grab hold of floating microscopic beads.

Bubonic plague has killed hundreds of millions of people during the course of history. It is the most devastating acute infectious disease known to man. Scientists remain uncertain about the molecular basis of its extraordinary virulence.
Bacteria that cause the bubonic plague may be more virulent than their close relatives because of a single genetic mutation, according to research published in the May issue of the journal Microbiology.
“The plague bacterium Yersinia pestis needs calcium in order to grow at body temperature. When there is no calcium available, it produces a large amount of an amino acid called aspartic acid,” said Professor Brubaker from the University of Chicago, USA. “We found that this is because Y. pestis is missing an important enzyme.”

Marine scientists led by Dr. Lothar Stramma from the Leibniz Institute of Marine Sciences (IFM-GEOMAR) in Kiel, Germany say they have made an alarming new discovery - in some regions of the world oceans, oxygen essential for marine organisms is declining.
The new study documents that the oxygen values in tropical oceans at a depth of 300 to 700 meters have declined during the past 50 years. As large marine organisms can either no longer exist in these areas or they would avoid them, the expanding oxygen minimum zones may have substantial biological and economical consequences.
The oxygen distribution in the ocean is not homogenous. At the eastern boundaries of the tropical oceans at depths between 200 and 800 metres, there are areas with reduced oxygen, the so-called oxygen minimum zones (OMZ). Rising CO2 levels are causing a temperature increase of the ocean and a general decline of oxygen solubility in the water.

"Random lasers" are not what chooses the songs in your CD player in shuffle mode, they are a class of microlasers which use the principle of random light scattering as an integral part of the their operation.
In conventional lasers light is trapped between two highly reflecting mirrors where it is amplified by pumping from outside. When this amplification process is efficient enough, the laser begins to operate.
After the initiation of the modern study of random lasers by Nabil M. Lawandy at Brown University, it was demonstrated by Hui Cao (Northwestern and Yale) and coworkers that you don't actually elaborate mirrors to confine light long enough for lasing from micron sized devices. All you need to do is to put light into a highly disordered medium where scattering in random directions takes place.

A study of 90,000 people has uncovered new genetic variants that influence fat mass, weight and risk of obesity. The variants act in addition to the recently described variants of the FTO gene: adults carrying variants in both genes are, on average, 3.8 kg (or 8.5 lb) heavier. The research could lead to better ways of treating obesity.
The variants map close to a gene called MC4R: mutations in this gene are the most common genetic cause of severe familial obesity. The study also highlights the power of large collections of volunteer samples to uncover common variants that influence health.
The study also shows that the gene sequence is significantly more common in those with Indian Asian than European ancestry.

Parents of children with autism were roughly twice as likely to have been hospitalized for a mental disorder, such as schizophrenia, than parents of other children, according to an analysis of Swedish birth and hospital records by a University of North Carolina at Chapel Hill researcher and colleagues in the U.S. and Europe.
The study examined 1,237 children born between 1977 and 2003 who were diagnosed with autism before age 10, and compared them with 30,925 control subjects matched for gender, year of birth and hospital. The large sample size enabled researchers to distinguish between psychiatric histories of mothers versus fathers in relation to autism. The association was present regardless of the timing of the parent’s diagnosis relative to the child’s diagnosis.

The genome analysis of a champion biomass-degrading fungus has revealed a surprisingly minimal repertoire of genes that it employs to break down plant cell walls, highlighting opportunities for further improvements in enzymes customized for biofuels production.
The discovery of Trichoderma reesei, the target of the published analysis, dates back to World War II, when it was identified as the culprit responsible for the deterioration of fatigues and tents in the South Pacific. This progenitor strain has since yielded variants for broad industrial applications and is known today as an abundant source of enzymes, particularly cellulases and hemicellulases, currently being explored to catalyze the deconstruction of plant cell walls as a first step towards the production of biofuels from lignocellulose.

A process of self-digestion called autophagy prompts the maturation of red blood cells. Without a protein called Nix, the cells would not effectively rid themselves of organelles called mitochondria and consequently become short-lived, leading to anemia, said researchers at Baylor College of Medicine in Houston.
“It’s changed our thinking on autophagy,” said Dr. Jin Wang, assistant professor of immunology at BCM and senior author of the report in Nature. During autophagy, the cell forms an envelope or vesicle around components of the cell that need to be degraded and removed. The vesicle then fuses with a cellular component called a lysosome that degrades its contents. The inclusion of components in the cell by autophagy vesicles was generally considered to be nonspecific.