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Some Harmful Effects of Light at Night Can Be Reversed, Study Finds

COLUMBUS, Ohio – Chronic exposure to dim light at night can lead to depressive symptoms in rodents – but these negative effects can be reversed simply by returning to a standard light-dark cycle, a new study suggests.

While hamsters exposed to light at night for four weeks showed evidence of depressive symptoms, those symptoms essentially disappeared after about two weeks if they returned to normal lighting conditions.

Even changes in the brain that occurred after hamsters lived with chronic light at night reversed themselves after returning to a more normal light cycle. (more…)

Some Mammals Used Highly Complex Teeth to Compete With Dinosaurs

By Guest PostMarch 19, 2012Nature, Science3 d images, alistair evans, angiosperms, australia, back teeth, bumps, computed tomography, ct, cusps, dinosaur extinction, dinosaurs, event, extinction, finland, food, fossil, gregory p wilson, ian corfe, insect pollinators, jukka jernvall, mammal, mesozoic era, mikael fortelius, monash university, mountain range, multituberculates, Nature, paleontologist, peter smits, rodent, scanning, tooth surface, topography, tubercles, university of helsinki, university of washington, vince stricherz

Conventional wisdom holds that during the Mesozoic Era, mammals were small creatures that held on at life’s edges. But at least one mammal group, rodent-like creatures called multituberculates, actually flourished during the last 20 million years of the dinosaurs’ reign and survived their extinction 66 million years ago.

New research led by a University of Washington paleontologist suggests that the multituberculates did so well in part because they developed numerous tubercles (bumps, or cusps) on their back teeth that allowed them to feed largely on angiosperms, flowering plants that were just becoming commonplace. (more…)

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Some Harmful Effects of Light at Night Can Be Reversed, Study Finds

Some Mammals Used Highly Complex Teeth to Compete With Dinosaurs