Stanford Today Edition: March/April, 1998 Section: News on Campus: Science and Medicine Briefs WWW: Science and Medicine Briefs
THE HYPOCRETIN DIET PLAN Two newly discovered brain messengers may lead to a deeper understanding of how the body controls weight. These neurotransmitters, dubbed hypocretins, are produced in the brain's hypothalamus. In other studies, researchers have linked cells in this area of the brain to the control of food consumption. "The discovery of a new neurotransmitter is always significant, but the location of these neurotransmitters in the brain makes this work particularly exciting," said senior research scientist Thomas Kilduff. The scientists now plan to test the effects of supplying excess hypocretins or preventing hypocretin production in experiments with mice or rats.
DYSLEXIA INSIGHT Between 3 and 9 percent of the population is affected by dyslexia, an impairment of the ability to read. For decades, doctors have disagreed over its cause. A new Stanford study finds that the disorder may be caused by a subtle vision problem. Researchers found that the level of brain activity in the visual cortex - the portion of the brain devoted to processing visual signals - appears to predict the speed at which people with dyslexia can read. This is only one of a handful of cases in which a strong link between individual behavior and brain differences has been established. "We found compelling evidence that there is a visual deficit associated with dyslexia, but at this time we don't know for certain if the deficit causes dyslexia or is just a marker for it," said David J. Heeger, assistant professor of psychology. Researchers caution that the study results are too preliminary to affect the diagnosis or treatment of dyslexia, but do suggest a line of research that could provide additional information about the relationship between visual system impairments and dyslexia. If future research should confirm the correlation between specific kinds of brain activity and dyslexia, it could lead to methods for diagnosing dyslexia at an earlier age than is now possible, the researchers said.
FULL HOUSE AT STANFORD HOSPITAL Empty hospital beds may be the norm in much of the country, but not at Stanford. The beds at Stanford University Hospital have been filled or nearly filled since the end of October. The shortage is even more acute at UCSF Medical Center. Although the statistics haven't been fully analyzed, managers say the space crunch results from a variety of factors, including a healthy economy that has more people working and, subsequently, covered by health insurance. Also, patients generally rush at the end of the year to use their insurance benefits before the deductibles expire. The shortage of beds, however, is not due to any cost-saving measures. Stanford and UCSF have not closed any beds and staffing ratios have remained roughly the same for the past four years.
PRECISION AGRICULTURE Tractors soon may be working the fields - minus drivers. Stanford researchers equipped a John Deere tractor with an automatic control system that guided the farm vehicle more precisely than the best human drivers. Using the Global Positioning System - a constellation of 24 satellites operated by the U.S. Department of Defense - the researchers could control the tractor at all speeds and with centimeter-level precision while the vehicle pulled a variety of implements. The team, which is supervised by Bradford Parkinson, the Edward C. Wells Professor of Aeronautics and Astronautics, achieved this level of control by adapting a method that they had developed for an automatic aircraft landing system in 1994. Proponents argue that precision agriculture can improve farm productivity while reducing the need for fertilizers, herbicides and pesticides. ST