Researchers from the California Institute of Technology (Caltech) and Trinity College in Dublin, Ireland have found that the reward centers in the human brain respond more strongly when a poor person receives a financial reward than when a rich person does. This activity pattern holds true even if the brain being looked at is in the rich person's head, rather than the poor person's.

The significance? The human brain is a big believer in equality, the scientists say. Their results are detailed in a new study appearing in Nature.

Many scientists warn that with a changing climate there's a good chance that forest fires in the Pacific Northwest will become larger and more frequent – and according to one expert, that's just fine.

The future of fire in this region is difficult to predict, will always be variable, and undoubtedly a part of the future landscape. People should understand, however, that fire is not only inevitable but also a valuable part of forest ecosystems and their management, says John Bailey, an associate professor in the Department of Forest Engineering, Resources and Management at Oregon State University.

Biologists from the American Museum of Natural History and the City University of New York have found that grizzly bears are roaming into what was traditionally thought of as polar bear habitat, the Canadian province of Manitoba, where they are officially listed as extirpated. The preliminary findings were published in Canadian Field Naturalist and show that sightings of Ursus arctos horribilis in Canada's Wapusk National Park are recent and appear to be increasing in frequency.

A team of paleontologists has discovered a new dinosaur species which belongs to the  same group of gigantic, long-necked, long-tailed, four-legged, plant-eating sauropods as Brachiosaurus. The new species has been dubbed 'Abydosaurus', and its discovery will be detailed in an upcoming issue of Naturwissenshaften.

The fossils were excavated from the Cedar Mountain Formation in Dinosaur National Monument near Vernal, Utah. The team recovered four heads – two still fully intact – from a quarry in Dinosaur National Monument in eastern Utah. Complete skulls have been recovered for only eight of more than 120 known varieties of sauropod.

In order to determine if there is cancer in the lymph nodes, pathologists must currently perform several  detailed, time-consuming tests. But University of Missouri researchers have developed a laser-induced ultrasound, called the photoacoustic method, that may help doctors locate the general area of the lymph node where melanoma cells are residing with much more efficiency than is currently possible. The new approach is detailed in the Journal of Biomedical Engineering.

Depression raises stress hormone levels in adolescent boys and girls but may lead to obesity only in girls, according to research in a recent issue of the Journal of Adolescent Health. Authors of the study suggest that early treatment of depression could help reduce stress and control obesity.

The hormone Cortisol regulates various metabolic functions in the body and is released as a reaction to stress. Researchers have long known that depression and cortisol are related to obesity, but they had not figured out the exact biological mechanism.