For more than 20 years, theoretical mathematical models have predicted that a delay built into a negative feedback system is at the heart of the molecular mechanism that governs circadian clocks in mammalian cells. Now, the first experimental proof of this theory has been provided by an international research team led by molecular biologists and information scientists from the RIKEN Center for Developmental Biology in Kobe. The demonstration of the feedback delay should lead to a better understanding of how cellular clocks function, and therefore how mammals adjust to the regular daily and seasonal changes in their environment. The work could also open the way to the development of treatments for circadian disorders, such as seasonal affective disorder, jet lag and even bipolar disorder.
The 2011 Arctic sea ice extent maximum that marks the beginning of the melt season appears to be tied for the lowest ever measured by satellites, say scientists at the University of Colorado Boulder's National Snow and Ice Data Center.
Ranchers in the central Great Plains may be using some of their winter downtime in the future to rehearse the upcoming production season, all from the warmth of their homes, according to U.S. Department of Agriculture (USDA) soil scientists.