What makes a pointer point, a sheep dog herd, and a retriever retrieve? Why do Yorkshire terriers live longer than Great Danes? And how can a tiny Chihuahua possibly be related to a Great Dane?

Dogs vary in size, shape, color, coat length and behavior more than any other animal and until now, this variance has largely been unexplained. Now, scientists have developed a method to identify the genetic basis for this diversity that may have far-reaching benefits for dogs and their owners.

In the cover story of Genetics, research reveals locations in a dog's DNA that contain genes that scientists believe contribute to differences in body and skull shape, weight, fur color and length – and possibly even behavior, trainability and longevity.

Is it worse to be fat or just to feel fat?

Quality of life is lower in obese children but it is unknown how much of that correlates to self-evaluation. If adolescents think they are “far too fat,” they forfeit a lot of their quality of life, whatever their actual weight.

If adolescents consider their weight “just right,” their quality of life is the same as if they were of normal weight, even if this is not true.

The results of a new survey say the proportion of German adolescents who think they are overweight has been increasing more rapidly in recent years than the proportion of those who really are overweight. As children have become fatter more of them still feel pressure to be thin even though they are told they should love themselves for who they are.

Turmeric, an Asian spice found in many curries, has a long history of use in reducing inflammation, healing wounds and relieving pain, but can it prevent diabetes? Since inflammation plays a big role in many diseases and is believed to be involved in onset of both obesity and Type 2 diabetes, Drew Tortoriello, M.D., an endocrinologist and research scientist at the Naomi Berrie Diabetes Center at Columbia University Medical Center, and his colleagues were curious what effect the herb might have on diabetic mice.

Dr. Tortoriello, working with pediatric resident Stuart Weisberg, M.D., Ph.D., and Rudolph Leibel, M.D., fellow endocrinologist and the co-director of the Naomi Berrie Diabetes Center, discovered that turmeric-treated mice were less susceptible to developing Type 2 diabetes, based on their blood glucose levels, and glucose and insulin tolerance tests. They also discovered that turmeric-fed obese mice showed significantly reduced inflammation in fat tissue and liver compared to controls. They speculate that curcumin, the anti-inflammatory, anti-oxidant ingredient in turmeric, lessens insulin resistance and prevents Type 2 diabetes in these mouse models by dampening the inflammatory response provoked by obesity.

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.