Technology
Scientists have shown, for the first time, that changes in a large-scale climate system can synchronize population fluctuations in multiple mammal species across a continent-scale region. The study, to be published in the 14 November 2002 issue of the journal Nature, compares long-term data on the climate system known as the North Atlantic Oscillation with long-term data from Greenland on the population dynamics of caribou and muskoxen, which are large mammals adapted to breeding in the Arctic.
Researchers for the first time have identified and ranked which diseases contribute most to the life-expectancy gap between races and between education levels. The top four contributors to the life-expectancy disparity between blacks and whites are hypertension, HIV, homicide and diabetes. The top six contributors of mortality differences between education levels are all smoking-related diseases.
Second-hand tobacco smoke threatens the health of 21 million American children ? 35 percent of everyone age 17 and younger ? who live in homes where residents or visitors smoke once a week or more, according to a study published Nov. 13 by researchers from RAND and UCLA. The study is the most thorough ever conducted of youths' exposure to environmental second-hand tobacco smoke at home. It found that 19 million American children ? 28 percent of everyone in the United States 17 and younger ? are exposed to tobacco smoke at home on a daily basis.
Scientists have coupled the protein that makes fireflies glow with a device similar to a home video camera to eavesdrop on cellular conversations in living mice. The team's research will allow scientists to study how cellular proteins talk to one another. These communications trigger changes that regulate a healthy body and cause disease when the signals go awry. The findings may speed development of new drugs for cancer, cardiovascular diseases and neurological diseases.
Routine monitoring of volcanic activity on Jupiter's moon Io has turned up the largest eruption to date on Io's surface or in the solar system. The eruption took place in February 2001, though image analysis was only recently completed by a team of University of California, Berkeley, astronomers. Their results are published in the November issue of the planetary sciences journal Icarus. "The Surt eruption appears to cover an area of 1,900 square kilometers, which is larger than the city of Los Angeles and even larger than the entire city of London," said the lead researcher. "The total amount of energy being released by the eruption is amazingly high, with the thermal output from this one eruption almost matching the total amount of energy emitted by all of the rest of Io, other volcanoes included."
Clinical tests began today of a novel vaccine directed at the three most globally important HIV subtypes, or clades. Developed by scientists at the Dale and Betty Bumpers Vaccine Research Center, part of the National Institute of Allergy and Infectious Diseases, the vaccine incorporates HIV genetic material from clades A, B and C, which cause about 90 percent of all HIV infections around the world. "This is the first multigene, multiclade HIV vaccine to enter human trials," said NIAID Director Anthony S. Fauci, M.D. "It marks an important milestone in our search for a single vaccine that targets U.S. subtypes of HIV as well as clades causing the global epidemic."
At least half of older adults with hypertension do not have their blood pressure controlled to normal levels, according to a survey of 5,888 patients around the country. The failure to control blood pressure to less than 140/90 mmHg may account for as much as 22 percent of myocardial infarctions and 34 percent of strokes in older adults, according to University of Washington researchers.
In a study that combines state-of-the-art biological imaging with gene expression analysis, scientists at the California Institute of Technology have uncovered a fundamental insight into the way embryonic cells and tissue move about to form key structures along the vertebrate axis. The study, which could lead to a better understanding of human development, takes advantage of the accessibility of chick embryos to embryonic manipulation. The study enters on segments known as somites, which form along either side of the future spinal cord of an embryo. Somites give rise to mature structures such as ribs, individual vertebrae, and even skin. The key role of somite segmentation in the patterning of the nervous system and the vertebral column has been long known. But the question of precisely how an individual somite buds off from a block of tissue in a pattern that is repeated all along the animal's torso, from head to tail, is poorly understood.
A new study has found that women athletes get far more pumped up before and during athletic competition than their male counterparts. Pre-event testosterone levels rise 9 percent, on avergae, in males whereas in females they increase by 24 percent. During the game itself women increase their testosterone production by 49 percent while in males, it increases on average 15 percent. The rise in testosterone that accompanies competition is thought to make the individual more willing to take risks, improves psychomotor function and coordination, and increase cognitive performance qualities that are very important in winning.
The nature of preteen friendships can play a key role in determining whether or not a child will engage in sexual activity early in adolescence, a new study suggests. For example, researchers found that boys who had mostly female friends when they were preteens were more likely to have had sex by age 16 than were other boys. However, the same wasn't true for girls who as preteens had mostly male friends.
Researchers report the first premature babies to receive an experimental artificial amniotic fluid appear to tolerate the solution, which was given orally in hopes it will help the infants' digestive system develop properly so they can eventually handle regular feedings. Very-low-birthweight babies, some born nearly four months before their due dates often weighing less than two pounds, are almost universally unable to digest human milk or formula. In their first days or weeks they are fed intravenously, which typically causes their intestines to degenerate from disuse-making feeding even more difficult when they later graduate to breast or bottle.
This image from the Chandra X-ray Observatory has given scientists their first look at X-rays from Mars. In the sparse upper atmosphere of Mars, about 75 miles above its surface, the observed X-rays are produced by fluorescent radiation from oxygen atoms. X-rays from the Sun impact oxygen atoms, knock electrons out of the inner parts of their electron clouds, and excite the atoms to a higher energy level in the process. The atoms almost immediately return to their lower energy state and may emit a fluorescent X-ray in this process with an energy characteristic of the atom involved ? oxygen in this case. A similar process involving ultraviolet light produces the visible light from fluorescent lamps.
Researchers from the Mayo Clinic say that wearing ionized bracelets for the treatment of muscle and joint pain is no more effective than wearing placebo bracelets. Authors of the published study randomly assigned 305 participants to wear an ionized bracelet for 28 days and another 305 participants to wear a placebo bracelet for the same duration. The study volunteers were men and women 18 and older who had self-reported musculoskeletal pain at the beginning of the study. Neither the researchers nor the participants knew which volunteers wore an ionized bracelet and which wore a placebo bracelet. Bracelets were worn according to the manufacturer's recommendations. Both types of bracelets were identical and were supplied by the manufacturer, QT, Inc.
Scientists have discovered the first "risk gene" for schizophrenia found in the general population. An uncommon variation of a gene called Nogo, when inherited from both parents, increases the risk of developing schizophrenia, says a study to be published in Molecular Brain Research. Previous findings about other risk genes for the disease were restricted to specific ethnic groups. "Finding a risk gene in the general population - the first finding of this type internationally - opens the door to discovering new and related risk genes," says one of the study's authors. "Now scientists will know where to look for related genes.... This will help in diagnosis and potentially in the design of new medications for treatment of this terrible disease."
Scientists have averted the onset of neurodegenerative disease in fruit flies by administering medication to flies genetically predisposed to a disorder akin to Parkinson's disease. The result suggests a new approach to the treatment of human disorders including Parkinson's and Alzheimer's diseases. Parkinson's disease is the second most common human neurodegenerative disorder, characterized by tremors, postural rigidity and progressive deterioration of dopaminergic neurons in specific areas of the brain. Despite the evolutionary gulf separating humans and fruit flies, neurotoxicity unfolds in a similar manner in both species.
