Individuals who are obese are at increased risk of many diseases, including type 2 diabetes and heart disease. As 75%-95% of previously obese individuals regain their lost weight, many researchers are interested in developing treatments to help individuals maintain their weight loss.

A new study, by Michael Rosenbaum and colleagues, at Columbia University Medical Center, New York, has provided new insight into the critical interaction between the hormone leptin and the brain's response to weight loss.

Leptin levels fall as obese individuals lose weight. So, the authors set out to see whether changes in leptin levels altered activity in the regions of the brain known to have a role in regulating food intake.

More than half of all older adults complain about having difficulties sleeping. Most don't bother seeking treatment. Those who do usually turn either to medications, which can lead to other health problems, or behavior therapies, which are costly and often not available close to home.

Now, UCLA researchers report that practicing tai chi chih, the Westernized version of a 2,000-year-old Chinese martial art, promotes sleep quality in older adults with moderate sleep complaints. The study, which will be published in the journal Sleep, is currently available in the journal's online edition.

In the study, 112 healthy adults ranging in age from 59 to 86 were randomly assigned to one of two groups for a 25-week period: The first group practiced 20 simple tai chi chih moves; the other participated in health education classes that included advice on stress management, diet and sleep habits.

Skin piercings might be the rage among teens, but researchers from Tel Aviv University have found good reasons to think twice about piercing one's tongue or lip.

Dr. Liran Levin, a dentist from the Department of Oral Rehabilitation, School of Dental Medicine at Tel Aviv University has found that about 15 to 20 percent of teens with oral piercings are at high risk for both tooth fractures and gum disease. Resulting tooth fractures as well as periodontal problems, he says, can lead to anterior (front) tooth loss later in life.

High rates of fractures due to piercings are not found in other age groups, and cases of severe periodontal damage in teens without oral piercings are similarly rare, says Dr. Levin, who conducted the study with partners Dr. Yehuda Zadik and Dr. Tal Becker, both dentists in the Israeli Army.

Researchers have found that female red squirrels showed high levels of multimale mating and would even mate with males that had similar genetic relatedness, basically mating with their relatives.

Researchers from the University of Alberta, in Edmonton, Alberta, Canada and the University of Sheffield in Sheffield, England, United Kingdom studied a population of red squirrels over a period of three years near Kluane National Park in southwest Yukon.

While males mating with multiple females is quite common in the animal kingdom, females that multi-mate is much harder to explain.

A new discovery by University of Western Ontario scientist Graham Thompson claims to be conclusive evidence that the 'selfish gene', introduced conceptually in 1976 by British biologist Richard Dawkins, isn't just accepted as a natural extension to the works of Charles Darwin, but is now confirmed.

In studying genomes, the word 'selfish' does not refer to the human-describing adjective of self-centered behavior but rather to the blind tendency of genes wanting to continue their existence into the next generation. Ironically, this 'selfish' tendency can appear anything but selfish when the gene does move ahead for selfless and even self-sacrificing reasons.

For instance, in the honey bee colony, a complex social breeding system described as a 'super-organism,' the female worker bees are sterile. The adult queen bee, selected and developed by the worker bees, is left to mate with the male drones.

Dr. Ira Sharlip, President of the International Society for Sexual Medicine (ISSM) detailed a new definition of premature ejaculation. He addressed the audience of the American Urological Association during the ‘late breaking science forum’, a session designed by AUA to premier newsworthy developments in clinical urology.

The ISSM convened a panel of world experts who met in Amsterdam in the fall of 2007. Each of the 21 members of the panel was selected through a peer review process for their expertise in ejaculatory physiology, pharmacology and dysfunction. The panelists were tasked with creating a new definition of premature ejaculation (PE) based on currently available clinical evidence. Definitions of PE have previously been based on group consensus and not meeting new standards for evidence-based medicine. These definitions of PE include the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV, 2002) and the AUA definition of (2005).