Yale
Hubble Space Telescope data, analyzed by a Yale astronomer using gravitational lensing techniques, has generated a spatial map demonstrating the clumped substructure of dark matter inside clusters of galaxies. Clusters of galaxies (about a million, million times the mass of our sun), are typically made up of hundreds of galaxies bound together by gravity. About 90 percent of their mass is dark matter. The rest is ordinary atoms in the form of hot gas and stars.
Direct field evidence shows that Lyme disease in humans can be prevented by vaccinating wildlife, researchers in the Department of Epidemiology and Public Health at Yale School of Medicine report in the Proceedings of the National Academy of Sciences. In a four-year study of isolated woodlands near New Haven, nearly 1,000 white-footed mice were trapped and either vaccinated against Lyme disease or given a placebo. Fewer deer ticks tested positive for Lyme disease in the experimental plots where mice had been vaccinated. Fewer ticks carrying infection reduced the risk for humans getting Lyme disease from a tick bite.
Imaging studies of the brain when it is under the influence of alcohol reveal that different areas of the brain are impaired under high and low levels of alcohol, according to a Yale study published in Neuropsychopharmacology. Godfrey Pearlson and Vince Calhoun, researchers in the Department of Psychiatry at Yale School of Medicine, used a statistical method to sort areas of the brain affected when persons were administered a placebo or two different doses of alcohol. The seven men and two women then ''drove'' using a simulated driving skill game.
Designing physical activity programs and interventions geared to breast cancer survivors will increase well-being and may improve prognosis, Yale researchers report. ''Despite the evidence suggesting that regular physical activity can protect against weight gain, decrease breast cancer risk, and potentially improve breast cancer prognosis, efforts to encourage physical activity are not a routine part of the cancer treatment or rehabilitation process,'' said principal investigator Melinda L. Irwin, assistant professor in the Department of Epidemiology and Public Health at Yale School of Medicine.
Blondes and redheads not only are more susceptible to skin cancer, but the source of their skin and hair pigmentation, melanin, actually magnifies the damaging effects of ultraviolet (UV) rays, according to a study published online this week in the Proceedings of the National Academy of Sciences. Melanin filters out UV radiation, but the melanin in hair follicles, particularly in light hair, actually increases the sun damaging effects of UV rays and causes cell death in the hair follicle, said Douglas Brash, principal investigator and professor of therapeutic radiology, genetics and dermatology at Yale School of Medicine.
Black and Hispanic patients experience marked delays in heart attack treatment compared with whites, Yale researchers report.
The study of approximately 110,000 heart attack patients treated in more than 1,000 hospitals across the country revealed that Hispanic or African American patients have a 10 to 20 percent longer time in getting the proper emergency treatment for restoring blood flow to the heart. Time to treatment in heart attacks is very important to patient survival and is an indicator of quality of care used by the Centers for Medicare and Medicaid Services and the Joint Commission on Accreditation of Healthcare Organizations.
In this week's issue of Nature, a Yale mathematician presents models showing that the most recent person who was a direct ancestor of all humans currently alive may have lived just a few thousand years ago. ''While we may not all be 'brothers,' the models suggest we are all hundredth cousins or so,'' said Joseph T. Chang, professor in the Department of Statistics at Yale University and senior author on the paper. Chang established the basis of this research in a previous publication with an intentionally simplified model that ignored such complexities as geography and migration.
Unlike younger recreational gamblers who show high rates of alcohol use and abuse, depression, bankruptcy and incarceration, there appears to be an association between recreational gambling and good health among elderly persons, according to a Yale study in the American Journal of Psychiatry. Rani Desai, associate professor of psychiatry at Yale School of Medicine, said it is not clear why there is a positive correlation of good health in moderate gamblers 65 years and older. It may be, she suggested, that healthier adults who are able to gamble are simply healthier to begin with. There may be other reasons as well, Desai said.
A genetic mutation related to a more aggressive form of breast cancer occurs four times more often in African American patients than their white counterparts, Yale researchers report in the August 9, 2004 online edition of the journal Cancer. In the United States, African-American women have a lower incidence of breast cancer than white women, but they have a higher mortality rate. The disease also develops at an earlier age and is more aggressive in African-American women.
In the brain, low levels of the inhibitory transmitter GABA and high levels of the excitatory neurotransmitter glutamate appear to be strongly associated with a particular type of depression, according to a study by Yale researchers.
The findings were made using proton magnetic resonance spectroscopy to observe the levels of GABA and glutamate in 38 healthy persons and 33 subjects with major depressive disorder.
The principal active ingredient in marijuana causes transient schizophrenia-like symptoms ranging from suspiciousness and delusions to impairments in memory and attention, according to a Yale research study. Lead author D. Cyril D'Souza, M.D., associate professor of psychiatry at Yale School of Medicine, said the study was an attempt to clarify a long known association between cannabis and psychosis in the hopes of finding another clue about the pathophysiology of schizophrenia.
Although people age 65 and older account for 62 percent of patients with lung, colon, breast or prostate cancer, they make up only 32 percent of cancer research participants, Yale researchers report in the June 9 Journal of the American Medical Association. ''We found that cancer research participation varied significantly across sex and racial/ethnic groups as well as age,'' said principal investigator Cary Gross, M.D., assistant professor of internal/general medicine at Yale School of Medicine. ''Enrollment in cancer trials is low for all patient groups, but the elderly, racial and ethnic minorities, and women were less likely to enroll in cooperative group cancer trials than were whites, men and younger patients.''
The ability to recognize persons encountered during highly threatening and stressful events is poor in the majority of individuals, according to a Yale researcher.
''Contrary to the popular conception that most people would never forget the face of a clearly seen individual who had physically confronted them and threatened them for more than 30 minutes, a large number of subjects in this study were unable to correctly identify their perpetrator,'' said Charles Morgan III, M.D., associate professor of psychiatry at Yale School of Medicine.
Employees who lose their jobs in the years immediately preceding retirement have twice the risk of suffering a stroke when compared to peers who are still working, according to a study by a Yale researcher. "Our results suggest that late career involuntary job loss more than doubles the risk of subsequent stroke," said William Gallo, the senior author of the study and associate research scientist in the Department of Epidemiology and Public Health at Yale School of Medicine.
Even small epileptic seizures can trigger widespread abnormal signals in brain networks leading to loss of consciousness, according to new findings by a Yale researcher. "We've known for a long time that the temporal lobe misfires during seizures," said Hal Blumenfeld, M.D., assistant professor of neurology and neurobiology at Yale School of Medicine and lead author of the study, "but we were amazed to discover that the temporal lobe also causes the rest of the brain to malfunction. That's why patients lose consciousness."
