Competing against older brothers and sisters can be tough work, as any youngest child will tell you. But new research from a biologist at the University of North Carolina at Chapel Hill shows that when it comes to some birds, you should reserve any underdog sympathies for the first born -- or rather, first laid -- siblings as well.
While most teenagers (60 percent) spend on average 20 hours per week in front of television and computer screens, a third spend closer to 40 hours per week, and about 7 percent are exposed to more than 50 hours of 'screen-time' per week, according to a study presented at the American Heart Association's 48th Annual Conference on Cardiovascular Disease Epidemiology and Prevention.
Though they perch far apart on the avian family tree, birds with the ability to learn songs use similar brain structures to sing their tunes. Neurobiologists at Duke University Medical Center now have an explanation for this puzzling likeness.
Tests on the influence that a stress-related hormone has on learning in ground squirrels could have an impact on understanding how it influences human learning, according to a University of Chicago researcher.
Bipolar Disorder (BPD or manic-depressive illness) is one of the most serious of all mental disorders, affecting millions of individuals worldwide. Affected individuals alternate between states of deep depression and mania. While depression is characterized by persistent and long-term sadness or despair, mania is a mental state characterized by great excitement, flight of ideas, a decreased need for sleep, and, sometimes, uncontrollable behavior, hallucinations, or delusions. BPD likely arises from the complex interaction of multiple genes and environmental factors. Unlike some brain diseases, no single gene has been implicated in BPD.
Girls with attention deficit hyperactivity disorder stand a substantially greater risk of developing eating disorders in adolescence than girls without ADHD, a new study has found.
Cocaine addicts often suffer a downward emotional spiral that is a key to their craving and chronic relapse. While researchers have developed animal models of the reward of cocaine, they have not been able to model this emotional impact, until now. Regina Carelli and colleagues report experiments with rats in which they have mimicked the negative affect of cocaine addiction and even how it drives greater cocaine use. They said their animal model could enable better understanding of the emotional motivations of cocaine addiction and how to ameliorate them.
New research by political scientists concludes that direct mail campaigns which include a social pressure aspect are more effective at increasing voter turnout and are cheaper than other forms of voter mobilization, including door-to-door or telephone canvassing.