Keay Davidson, Chronicle Science Writer, Is evolution like a well-tuned car that purrs down the road at a steady pace? Or is it more like an aging, rattling jalopy that often lurches forward? The aging jalopy is a handy metaphor for the evolutionary theory popularized by Stephen Jay Gould, who died of cancer last week at age 60. Thanks to Gould's numerous popular writings, his theory known as "punctuated equilibrium" has been at the center of a major scientific debate since the early 1970s. Gould and his colleague Niles Eldredge argued that the evolution of life isn't a slow, steady, gradual process, as conventional scientific wisdom held. Rather, they said, evolution is a multi-million-year saga usually characterized by brief, sudden shifts separated by long periods of little or no change. ©2002 San Francisco Chronicle

Keyword: Evolution
Link ID: 2153 - Posted: 06.24.2010

By JOHN O'NEIL A change is as good as a rest for a brain worn down by working too long on one task, according to a study released yesterday in the journal Nature Neuroscience. A group of researchers tried to find out why too much practice could make performance slump. Led by Dr. Sara C. Mednick, a Harvard psychologist, the researchers put 30 well-rested people through the same set of tasks — distinguishing between shapes that were displayed very briefly — four times in the course of day, starting at 9 a.m. and ending at 7 p.m. Copyright 2002 The New York Times Company

Keyword: Attention; Sleep
Link ID: 2152 - Posted: 06.24.2010

By JANE E. BRODY I slowed down as I approached a fork in the highway, unsure of which arm to take. The driver behind me was on my tail, so impatient that he tried to pass me on the right just as I headed for the right fork, forcing him to slam on his brakes. He became so infuriated that he pulled right in front of my car and each time I moved he repeatedly slammed on his brakes, forcing me to brake suddenly again and again, endangering not only me but himself and the driver behind me. While his road rage was short of a shooting, it was rage nonetheless and extremely unnerving. Copyright 2002 The New York Times Company

Keyword: Aggression; Emotions
Link ID: 2151 - Posted: 05.28.2002

Statistical analysis applied to fraternal birth order effect by Jessica Whiteside -- Roughly one in seven gay men may owe his sexual orientation to the fact he has older brothers, say U of T researchers. Earlier studies have shown that each additional older brother increases the odds of homosexuality in a younger brother. "This phenomenon, known as the fraternal birth order effect, was first shown by Professor Ray Blanchard [of U of T's Department of Psychiatry and the Centre for Addiction and Mental Health] and has since been confirmed by other scientists," says CAMH post-doctoral fellow James Cantor. Cantor is co-author of a new study to determine the proportion of gay men whose sexual orientation is due to this effect. "This latest study demonstrates just how important that link is," says Cantor.

Keyword: Sexual Behavior
Link ID: 2150 - Posted: 05.28.2002

CHAPEL HILL – About 10 years ago, Dr. Robert Golden and University of North Carolina at Chapel Hill colleagues discovered an important new clue to the cause of depression, one that other researchers eventually confirmed. They found that depressed people showed a blunted hormonal response to a test he developed that boosts serotonin, an important neurotransmitter chemical in the brain. "This neuroendocrine challenge test, which involved giving depressed volunteer patients a medicine called clomipramine, indicated that depressed patients’ serotonin systems were sluggish in response and not working efficiently," Golden said. "An analogy I use is that their serotonin ‘engine’ needs a tune-up because they aren’t getting much mileage out of the gas being burned."

Keyword: Depression
Link ID: 2149 - Posted: 06.24.2010

By AAP Are women responsible for the intelligence of the human race because they consistently pick brain over brawn when choosing mates? A study by German geneticists supports the controversial theory that women approach brains as a sexual ornament - much like a lion's mane or a peacock's tail - according to a report in New Scientist magazine. Developments in genetics allowed the German team to build on previous studies by finding more evidence that the X chromosome carries intelligence.

Keyword: Intelligence; Sexual Behavior
Link ID: 2148 - Posted: 05.28.2002

NewScientist.com news service People who have trouble controlling their anger might be suffering from a mild form of brain dysfunction, say US researchers. Their tests suggest that being prone to aggressive, even violent, outbursts is linked to impairments in a region of the brain called the orbital/medial prefrontal cortex circuit. Psychiatric diagnoses of the condition, known formally as Intermittent Explosive Disorder (IED) are rare. But Mary Best at the Children's Hospital of Philadelphia says: "Even individuals who do not meet full criteria for the disorder can still have frequent uncontrollable episodes of impulsive aggression, and they can impact society through their violent behaviour. An example would be a spousal abuser." The disorder usually starts in adolescence, and most cases probably go undiagnosed, says Best. Some psychologists have blamed IED episodes for recent cases of school pupils massacring fellow students. © Copyright Reed Business Information Ltd.

Keyword: Aggression; Emotions
Link ID: 2147 - Posted: 06.24.2010

MRI measures size of key memory center in brain By Adam Marcus HealthScoutNews Reporter MONDAY, (HealthScoutNews) -- Head scans that measure the size of a key memory center in the brain may help doctors predict Alzheimer's disease decades before a patient's mental ability falters, new research has found. The findings involve an area deep in the brain called the hippocampus, one of the earliest sites to be affected by Alzheimer's. Using magnetic resonance imaging (MRI), the researchers showed that at death women with dementia linked to the degenerative disorder had markedly smaller hippocampus volume compared with women who died with normal brain function intact. More modest changes were also evident in women with the cellular scars of early Alzheimer's but no memory loss when they died. "We wanted to see if we looked at people who were not demented and had no memory impairment, could we identify which had Alzheimer's by looking at the volume of the hippocampus," said James Mortimer, director of the Institute on Aging at the University of South Florida in Tampa and a co-author of the study. "We can do it with great accuracy." Copyright © 2002 ScoutNews, LLC. All rights reserved.

Keyword: Alzheimers; Brain imaging
Link ID: 2146 - Posted: 06.24.2010

A treatment which uses "master cells" from the muscles could eventually help patients with the muscle-wasting illness muscular dystrophy. The experiments - although so far only in mice - restored some muscle strength. People with muscular dystrophy do not have the ability to make a protein called dystrophin - which is vital to keep muscles working properly. Doctors used stem cells taken from the muscles of healthy newborn mice. These were then transplanted into the muscles of mice bred to simulate muscular dystrophy. Scientists found that the stem cells turned not only into muscle cells, but also into nerve and blood vessel cells. (C) BBC

Keyword: Muscles; Stem Cells
Link ID: 2145 - Posted: 05.27.2002

By JANE E. BRODY My father died suddenly of his second heart attack while shopping for groceries. Though he was a very sweet and caring man, patience was not his strong suit, and my mother was convinced that his irritation over being stuck behind a garbage truck on the way to the store ultimately did him in. There have been countless reports seeking to link heart disease and sudden death to various personality traits: aggressiveness, nervousness, anxiety, impatience, irritability, hostility, as well as the whole package of such characteristics labeled Type A behavior. Copyright 2002 The New York Times Company

Keyword: Stress
Link ID: 2142 - Posted: 05.27.2002

Science pioneering technology that will help restore vision By Jim Krane, Associated Press NEW YORK -- When 68-year-old Robert Rosene became a bionic-eyed man, he didn't get the Six Million Dollar Man's telescoping vision. Rosene, of St. Charles, Ill., was all but pitch-black blind before getting a microchip slipped into his retina last year. He now sees globs of light and shadow, but not his wife's face. For Cora Jean Kleppe, 73, who got a bionic ear last month, silence has been upended by a cascade of sounds: the ding of the microwave oven, the eager chatter of her grandkids and the tweeting of birds in her San Mateo, Calif. garden. © The E.W. Scripps Co.

Keyword: Robotics; Vision
Link ID: 2141 - Posted: 06.24.2010

UK scientists have found strong evidence suggesting that diabetes is caused by a virus. The finding raises the possibility of developing a vaccine for the disease. The researchers have discovered a marked difference between the way the bodies of healthy individuals and those newly diagnosed with diabetes respond to a virus known as Coxsackie B4. Dr Mark Peakman led the three-year-study at the Department of Immunology at Guy's, King's and St Thomas' School of Medicine. He said: "The implications are clear: if viruses have a proven role in the disease, there is the future possibility of developing vaccines to prevent infection and therefore Type 1 diabetes." Type 1 diabetes is an autoimmune disease in which the body lacks insulin, the hormone which controls the sugar levels in the bloodstream. People with the condition have to inject insulin daily instead. (C) BBC

Keyword: Obesity
Link ID: 2139 - Posted: 05.25.2002

A pioneering technique using dogs to detect prostate cancer is being developed in Cambridgeshire. Researchers at Cambridge University have applied for funding to test their theory that a dog's sense of smell could provide a better early warning system for some cancers than modern science. They hope to train dogs to react to cancer cells in urine samples, revolutionising the screening process for conditions like prostate cancer. If the university gets funding it will ask professsional dog trainer Charlie Clarricoates, of Soham, Cambridgeshire, to carry out the experiment. Dr Barbara Sommerville, of the University's Department of Clinical Veterinary Medicine, said: "If there is a consistent change in odour the dogs will be able to detect it, of that we are in no doubt. (C) BBC

Keyword: Chemical Senses (Smell & Taste)
Link ID: 2138 - Posted: 05.25.2002

The body's circadian clock finally has received some hands. Scientists discovered a molecule in the brain's master clock that signals to the rest of the body that it's daytime. Injected into the brain, the molecule disrupts the natural daily rhythms of mice for several days. The findings may pave the way for new drugs to treat sleep disorders and jetlag. Like intertwining cogwheels in a mechanical watch, a pool of periodically expressed genes keeps time in a tiny region of the brain called the suprachiasmatic nucleus. Light sensors in the retina normally keep the clock set to the daily cycle of the sun, but even in absolute darkness these genes define a rough 24-hour day-night cycle. Although scientists have learned a great deal about how light sets the clock and have identified many of its components, they haven't understood how the clock in the brain keeps the rest of the body in synch. Copyright © 2002 by the American Association for the Advancement of Science.

Keyword: Biological Rhythms
Link ID: 2136 - Posted: 06.24.2010

Enriched Egg Yolks Boost Vital Nutrition By Jennifer Warner -- Moms and dads of weaning infants may want to incorporate egg yolks into their babies' diet. This may be an easy and practical way to provide iron and other much-needed nutrients that may become depleted during this time. Both breastfed and formula-fed infants face several important nutritional challenges as they approach weaning age of 4 to 6 months. For example, since breast milk is a good source of iron, iron-rich weaning foods are needed to prevent iron deficiency. Formula-fed infants may experience a deficiency of a fatty acid known as DHA, which is vital to the growth and development of the brain. The FDA recently approved the addition of DHA to infant formulas in the U.S. to avoid this problem. Breastfeeding provides sufficient DHA. However, doctors still don't know if weaning foods high in fatty acids such as DHA are important for continued development. © 2002 WebMD Inc. All rights reserved.

Keyword: Development of the Brain
Link ID: 2135 - Posted: 06.24.2010

ROCHESTER, Minn., (UPI) -- Scientists said on Friday they have discovered an enzyme that appears to cause the nerve impairment in the brain and spinal cord characteristic of multiple sclerosis. The finding, which appears in the journal Brain, could lead to new treatments for the degenerative condition. they said. "If we could inhibit the enzyme, maybe we could slow the progress of the disease or reverse it," Isobel Scarisbrick, Mayo Clinic neuroscientist and lead author of the study, told United Press International. Copyright © 2002 United Press International

Keyword: Multiple Sclerosis
Link ID: 2134 - Posted: 06.24.2010

NWO (Netherlands Organization for Scientific Research) Mentally fatigued trial subjects search less systematically for solutions than fit colleagues. Such fatigued persons switch to an automatic pilot approach even when this repeatedly leads to the same mistakes. Psychologists from the University of Amsterdam studied how purposefully mentally fatigued persons conducted themselves. Healthy persons and persons made mentally tired were subjected by the scientist to various tests. The tests revealed that fatigued persons had difficulty in translating objectives into the associated actions. The mentally fatigued person was less flexible, more persistent in his behaviour and had a lack of self-regulation. In one of the tests the trial subjects had to change the layout of a table in the computer programme Excel. The persons had never previously worked with Excel and were given an example of the end result on paper. The persons had to think aloud whilst carrying out the task. Their actions were registered by the computer and recorded on video. Prior to the test, half of the trial subjects were made mentally tired. They had to draw up schedules for two hours. The other half of the trial subjects was allowed to relax for two hours. © AlphaGalileo 2002

Keyword: Attention
Link ID: 2133 - Posted: 06.24.2010

By Mark K. Anderson According to fundamental laws of physics, time is just another coordinate -- hash marks along a line with scarcely a preferred direction or flow. Yet the mind perceives time as an irreversible stream, moving from past to future, experienced in the present. Manipulating time may make for good science fiction, but it's hardly conceivable to those unfortunates who don't have a Tardis or H.G. Wells' secret recipe. How can science bridge the gaping gulf between these two versions of time? © Copyright 2002, Lycos, Inc. All Rights Reserved.

Keyword: Attention
Link ID: 2132 - Posted: 06.24.2010

Lonely people may be at a higher risk of developing heart disease, researchers suggest. A US study showed that lonely people's cardiovascular systems worked differently to people who were not lonely, in ways which put them at higher risk of heart disease. A second UK study suggests it may be wrong to link stress to heart disease. They suggest previous research which made the link could have been weighted too heavily on people's own reports of their stress levels and symptoms, rather than objective measures. (C) BBC

Keyword: Stress
Link ID: 2131 - Posted: 05.24.2002

NewScientist.com news service Fears that the infectious prion proteins that cause BSE could be present in chicken fillets have been raised after bovine protein was found in breast fillets tested by the Irish Food Safety Authority (FSAI). The tests on the Dutch imports follow a report by the UK Food Standards Agency in December 2001 that undeclared pig proteins had been used to "bulk up" chicken from Holland and Belgium. The FSAI also found undeclared hydrolysed collagen in 26 per cent of the chicken fillets. Species-specific DNA tests on 30 chicken samples then revealed that 17 contained bovine DNA, porcine DNA or both. As yet, the authorities have been unable to trace the source of the undeclared bovine material. © Copyright Reed Business Information Ltd.

Keyword: Prions
Link ID: 2130 - Posted: 06.24.2010