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.”

If you use one of America’s top internet service providers, you may share server space with an organization that enables worldwide terrorism, says a new study by Tel Aviv University.

The findings were presented in Berlin to a closed audience of high-ranking representatives from NATO in February 2008.

Enlisted by NATO officials to study the web activity of terrorist organizations, researchers found that some of the world’s most dangerous organizations are operating on American turf. Hezbollah, the Islamic Jihad, and al-Qaeda all have websites hosted by popular American Internet service providers –– the same companies that most of us use every day.

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.