Bees are not as busy as they are made out to be. In fact the insects are lazy, workshy and prone to sleeping on the job, according to new research. Bees sleep for 80 per cent of the night and like to spend long periods "resting their wings", an award-winning German zoologist has found. Prof Randolf Menzel, from the Free University in Berlin, said that the popular image of bees as the ultimate hard workers was inaccurate. "Bees are not particularly hard working. Instead they sleep a lot and are actually quite lazy," he said. "They spend up to 80 per cent of the night sleeping rather than working in the hive - and during the day they often sit around in the hive resting their wings and doing not much else." Although we see bees buzzing around tirelessly in spring and summer, pollinating flowers and producing honey-filled hives, the common belief in a bee's busy nature is based on a misconception, he said. © Copyright of Telegraph Group Limited 2004.

Keyword: Sleep
Link ID: 5736 - Posted: 06.24.2010

It sounds like the beginning of a joke: "How do bacteria know what time it is?" The surprising answer, reported today in Nature, is that some of these single-celled entities actually have internal clocks. In a living organism, changes in gene expression, physiology and behavior that follow the cycle of day and night are called circadian rhythms. This oscillation is well known to occur in various mammals, insects, plants and fungi. But in recent years researchers have discovered that some single-celled organisms, too, display circadian rhythms. Irina Mihalcescu of the University Joseph Fourier in Saint Martin d'Heres, France, and her colleagues studied cyanobacteria, or blue-green algae, that had been engineered to light up when a particular regulatory gene turned on. By observing the pattern of illumination under a microscope, the scientists could measure the internal clockwork of individual bacteria. Previous research had found that these photosynthetic bacteria keep a daily schedule even without stimuli from the outside world. Under such constant conditions, Mihalcescu and her co-workers found that the bacteria maintained a specific rhythm even following cell division--that is, the clock-setting was passed on to subsequent generations. To determine whether intercellular interactions influence this synchronicity, the team grew two cell colonies shifted in time by three hours--like New Yorkers and Californians. When the scientists combined the bacteria, individuals resisted changing their clocks even when butting up against those from a different time zone. © 1996-2004 Scientific American, Inc. All rights reserved.

Keyword: Biological Rhythms
Link ID: 5735 - Posted: 06.24.2010

CHAPEL HILL -- Scientists at the University of North Carolina at Chapel Hill have discovered key steps involved in regulating nerve growth and regeneration that may have implications for spinal cord research. The new research, published in the June 24 issue of the journal Neuron, for the first time describes how nerve growth factor (NGF) stimulates a sequence of proteins – a molecular pathway – that promotes nerve growth. "It is the first study to show the link between NGF and the building blocks that form the axon," said Dr. William Snider, professor of neurology and cell and molecular physiology at UNC's School of Medicine and director of the UNC Neuroscience Center. Axons are long tendrils, or processes, that extend from nerve cells to form connections with other nerve cells, muscles and the skin. Injury to the peripheral nervous system – that portion of the nervous system outside the brain and spinal cord – typically results in spontaneous regeneration and repair. However, this is not the case with the spinal cord, where disruption of connections from injury leads to paralysis

Keyword: Regeneration
Link ID: 5734 - Posted: 06.24.2010

By Rossella Lorenzi, Discovery News — Males do not listen, at least if they are Manx shearwater sea birds, new research has shown. Puffinus puffinus, best known as Manx shearwaters for their habit of gliding on stiff wings along the troughs of waves, marry for life and share the incubation of a single egg. The chick is then raised by both parents who feed it with regurgitated food. Scientists at Leeds and Cardiff universities put microphones into the burrows of nesting shearwaters and discovered that males regularly provide more food to their offspring than the females. “ Males return to the nest at least once every four days, bringing back food with predictable regularity, regardless of the chick's cries. ” The reason is not that they are better parents, said Keith Hamer of Leeds University's biology department — they just don't listen to the begging calls of their chicks. Copyright © 2004 Discovery Communications Inc.

Keyword: Animal Communication; Sexual Behavior
Link ID: 5733 - Posted: 06.24.2010

Individuals who suffer from severe depression have more nerve cells in the part of the brain that controls emotion, researchers at UT Southwestern Medical Center at Dallas have found. Studies of postmortem brains of patients diagnosed with major depressive disorder (MDD) showed a 31 percent greater than average number of nerve cells in the portion of the thalamus involved with emotional regulation. Researchers also discovered that this portion of the thalamus is physically larger than normal in people with MDD. Located in the center of the brain, the thalamus is involved with many different brain functions, including relaying information from other parts of the brain to the cerebral cortex. The findings, published in today's issue of The American Journal of Psychiatry, are the first to directly link a psychiatric disorder with an increase in total regional nerve cells, said Dr. Dwight German, professor of psychiatry at UT Southwestern. "This supports the hypothesis that structural abnormalities in the brain are responsible for depression," he said. "Often people don't understand why mentally ill people behave in odd ways. They may think they have a weak will or were brought up in some unusual way.

Keyword: Depression
Link ID: 5732 - Posted: 07.01.2004

By Charles Choi, United Press International NEW YORK, (UPI) -- Implantable microchips that stimulate nerve cells with puffs of chemicals instead of pulses of electricity are being developed to serve as prosthetic retinas for the blind, scientists told United Press International. The microchips also could be used as medicine-delivering implants for treating diseases such as Parkinson's. "It's a very new way to interface with the brain," said lead researcher Harvey Fishman, director of the Stanford Ophthalmic Tissue Engineering Laboratory in California. Implantable devices that electrically stimulate nerve cells are commonplace, including cochlear implants that help deaf patients hear and deep brain stimulating electrodes that help Parkinson's patients cope with their symptoms. "When you're stimulating something electrically, you're doing so very indiscriminately," Fishman told UPI. "And you're not stimulating the nerve cell or muscle the way it's normally stimulated." Copyright © 2001-2004 United Press International

Keyword: Vision; Parkinsons
Link ID: 5731 - Posted: 06.24.2010

Alex Proyas never got a high school diploma - a fact he blames on Isaac Asimov. It was Asimov's short story "Nightfall" that derailed Proyas' academic career. "It's a wonderful vision of how the world can suddenly descend into anarchy," says Proyas, 41, describing the chaos that ensues in "Nightfall" when all six of a planet's suns set for the first time in 2,049 years. "I tried to convince my English teachers to assign us some science fiction, but they wouldn't. It opened a rift between my creative desires and what the system wanted me to explore." So Proyas quit school and took his education upon himself, reading the works of Asimov, Ray Bradbury, Arthur C. Clarke, and Philip K. Dick. It makes sense then that Proyas' career as a film director has been defined by fantasy. His 1994 movie The Crow, based on the James O'Barr comic book, immediately gained cult status after Brandon Lee (the only son of kung fu master Bruce Lee) was killed in a freakish accident on set. In 1998, he directed Dark City, a visually rich and haunting movie about the surreal wanderings of an amnesiac accused of murder. "I like movies made for adolescent grown-ups," says Proyas. "A few decades ago, it was still true that the golden age of science fiction readers was 12, but in my lifetime, it's become a mainstream genre." This July, Proyas turns again to his favored genre with I, Robot, an adaptation of Asimov's nine-story collection of the same name. "This is the definitive movie about robots," says Proyas. "It's the most faithful cinematic reworking of Asimov's stories to date, true to the spirit and ideas, yet reenvisioned." The film takes place in Chicago in the year 2035, just as the NS-5 automated domestic assistant comes to market. The all-purpose personal robot is expected to have such wide appeal that it will shift the ratio of humans to bots from about 15 to 1 to 5 to 1. But the release is tarnished when an NS-5 named Sonny is accused of murder. © Copyright© 1993-2004 The Condé Nast Publications Inc.

Keyword: Robotics
Link ID: 5730 - Posted: 06.24.2010

Few ailments sound scarier than mad cow disease and its human counterparts. They incubate silently for years, slowly eating the brain away and leaving it full of holes. So it's not surprising that many people want the U.S. Department of Agriculture to test all cattle for the illness, formally called bovine spongiform encephalopathy (BSE). Certainly testing all 35 million cattle slaughtered annually would reopen trade with Japan, which has refused American beef since the discovery of a mad cow in Washington State last December. It might prevent BSE-free countries from dominating the export market. And consumers might simply feel better about their steaks, roasts and burgers. Too bad there's not much science to back up the proposal. Commercial "rapid tests" are not designed to detect the disease reliably in most slaughtered bovines. They work best on those that have lived long enough to build up in their brains a detectable amount of prions, the proteins at the root of BSE. Typically those animals are older than 30 months or have symptoms, such as an inability to stand (called downer cattle). Most U.S. bovines, however, reach slaughter weight before 24 months of age--before the tests can accurately detect incubating BSE. Most European countries recognize those limitations and target cattle 30 months and older. But using current kits on all slaughtered animals, at least 80 percent of which are younger than 30 months, may give misleading assurance about the safety of beef. © 1996-2004 Scientific American, Inc.

Keyword: Prions
Link ID: 5729 - Posted: 06.24.2010

By Larry O'Hanlon — Elephants may be listening with their feet as well as with their ears, say researchers who are studying how well super-low frequency elephant song moves through the ground. For about 20 years it's been known that African elephants sing out and respond to calls so low that they are beyond human hearing. Until now, however, no one was sure if the rumbling calls were also moving through the Earth as seismic waves, possibly helping elephants communicate when there is too much noise above ground. "They are trying to prove the concept is possible," said elephant researcher Katy Payne of the Cornell University Bioacoustics Research Program, referring to a team of Stanford University researchers who have published a paper on seismic elephant infrasound calls in the current issue of Geophysical Research Letters. "We have several experiments going on right now to try to determine whether elephants perceive seismic cues via bone through their toenails and foot bones to their middle ear bones, or through vibration-detecting cells in the bottom of the foot," said Stanford's Caitlin O'Connell-Rodwell, now studying the matter in Namibia. Copyright © 2004 Discovery Communications Inc.

Keyword: Hearing
Link ID: 5728 - Posted: 06.24.2010

Using advanced imaging technology, Carnegie Mellon University scientist Eric Ahrens and co-investigators have conducted the first systematic examination of developmental and sex-associated changes in adolescent and adult mouse brains to reveal fundamental differences in key brain structures, such as those important for emotions, learning, and memory. The results, in press with NeuroImage, show that sex hormones alter the development of certain brain structures during puberty and that these effects persist into adulthood. The findings provide a much truer representation of how circulating hormones affect brain structures than could be derived from human imaging for several reasons, according to Ahrens. The animals studied were nearly genetically identical and reared in the same environment -- factors that cannot be controlled in human studies. And the imaging technology, magnetic resonance microscopy, allows high resolution, 3D imaging in the intact, tiny mouse brain. "The finding that specific brain structures change at puberty under the influence of sex hormones should help scientists understand how levels of sex hormones alter the brain's development," said Ahrens, assistant professor of biological sciences. "Researchers could artificially manipulate sex hormones and then use MRM technology to see how the hormones affect brain structures in animal models."

Keyword: Development of the Brain
Link ID: 5727 - Posted: 06.30.2004

Monkeys and apes who are good at deceiving their peers also have the biggest brains relative to their body size. The finding backs the "Machiavellian intelligence" theory, which suggests the benefits of complex social skills fuelled the evolution of large primate brains. Of all the terrestrial mammals, primates have by far the largest brains relative to their body size, with humans having the largest of all. The enlargement is almost exclusively in the neocortex, which makes up more than 80% of the mass of the human brain. Large brains, despite being energetically costly, benefited primates because they conferred complex cognitive skills. But which skills were the priority - was it clever food-finding strategies that were most valuable, for example, or complex social skills? Earlier studies have hinted that social abilities were the key. And now Richard Byrne and Nadia Corp, psychologists at St Andrews University in the UK, have found more direct evidence for this after studying records of primates deceiving each other for personal gain. © Copyright Reed Business Information Ltd.

Keyword: Evolution; Intelligence
Link ID: 5726 - Posted: 06.24.2010

–Bethesda, MD – Concurrent with the national obesity epidemic has been a rise in the discoveries about how the body controls appetite and food intake. In many of the new findings, research has identified a close relationship between the gastrointestinal endocrine system and the brain in regulating food intake. The relationship is expressed in coordination where circulating hormones convey information about food intake and appetite to brain pathways that control eating. A team of researchers has added to this knowledge through their investigation of cholecystokinin (CCK) and glucagon-like-peptide-1 (GLP-1), two pre-absorptive signals that indicate when the appetite is satisfied (“satiety”). Both peptides are classical gastrointestinal hormones that are released into the circulation in response to meal consumption. Earlier research has documented that these peptides participate in controlling the appetite in healthy volunteers, and also in patients with obesity or Type II diabetes. To further explore potential interactions between these two well-known satiety signals, the research team has examined the effects of CCK-33 and GLP-1 and the hormones’ interaction in the control of food intake and satiety in healthy subjects. The authors of the study, “Interaction between GLP-1 and CCK-33 in Inhibiting Food Intake and Appetite in Men,” are Jean-Pierre Gutzwiller, Lukas Degen, Daniel Matzinger, Sven Prestin, and Christoph Beglinger, all from the University Hospital, Basel, Switzerland. Their research appears in the Articles in PresS section of the American Journal of Physiology –Regulatory, Integrative and Comparative Physiology.

Keyword: Obesity
Link ID: 5725 - Posted: 06.24.2010

Electronic skin could give machines a sophisticated sense of touch. PHILIP BALL Robots are about to get more feeling. An electronic skin as sensitive to touch as our own is being developed by scientists in Japan. "Recognition of tactile information will be very important for future generations of robots," says Takao Someya at the University of Tokyo who developed the skin. A sense of touch would help them to identify objects, carry out delicate tasks and avoid collisions. But while a lot of effort has gone into vision and voice recognition for robots, touch sensitivity is still fairly rudimentary. Our own skin contains a battery of touch receptors that produce nerve signals when pressed. For gentle pressures, the main sensors are tiny bulbs of layered tissue called Meissner's corpuscles. Their behaviour is mimicked in plastics such as polyvinylidene fluoride, which generate an electric field when squeezed and are used to make pressure-sensitive pads for computer keyboards and other touch-triggered devices. © Nature News Service / Macmillan Magazines Ltd 2004

Keyword: Robotics; Pain & Touch
Link ID: 5724 - Posted: 06.24.2010

The risks of passive smoking could be twice as bad as previously feared, the British Medical Journal has reported. Researchers from London's St George's and Royal Free hospitals found passive smoking increased the risk of coronary heart disease by 50-60%. The team, which studied 4,792 men over 20 years, said earlier studies which had found a 25-30% increased risk focused on people living with smokers. They did not take account of exposure at work and other places, it added. Doctors at the British Medical Association conference this week have called for a workplace smoking ban. Previous research has linked passive smoking to increased risk of heart disease and stroke. (C)BBC

Keyword: Drug Abuse
Link ID: 5723 - Posted: 06.30.2004

By Caroline Ryan Botox could be used to treat a sexual condition which prevents women having full intercourse, scientists say. Iranian researchers have used the muscle-relaxing toxin - normally associated with wrinkle treatment - to treat women with vaginismus. The psychosomatic condition causes muscle spasms that prevent penetrative intercourse. Many thousands of UK women are thought to suffer from the condition, but cases are often unreported or undiagnosed. The work was presented to the European Fertility Conference in Berlin. Vaginismus can be triggered by traumatic events such as relationship problems or feelings of guilt about sex. Women with the condition associate sex with pain, which can have a huge impact on their lives and on their relationships with their partners. The aim of doctors treating the condition is to enable women to have pain-free intercourse, allowing them to break the pattern. Botox is made from the botulinum toxin produced by the bacterium which causes botulism food poisoning. (C)BBC

Keyword: Sexual Behavior
Link ID: 5722 - Posted: 06.30.2004

Does stationing themselves in front of the television for hours during the day affect children's ability to sleep? "Sleep experts have known for quite some time that staying up late and watching a lot of TV is one of the ways that people can have trouble falling asleep," says Jeffrey Johnson, professor of psychiatry at Columbia University and research scientist at the New York State Psychiatric Institute. Now, the first long-term study on the association between television viewing and sleep reveals a relationship between extensive TV watching and the development early adulthood sleep problems. Starting in 1975, Johnson's colleagues analyzed data about TV viewing habits from 759 parents and children. Television viewing was put into three categories: less than an hour per day, one to three hours per day, and three or more hours per day. When the study began, the children were six years old; some randomly selected children from the group were interviewed about their viewing habits at ages 14, 16, and 22 years (their mothers were interviewed separately). If parent and child had differing answers, the higher of the two answers was used. Johnson, whose research was published in Archives of Pediatrics and Adolescent Medicine, found that heavy TV viewing was associated with difficulty falling asleep, and waking up in the middle of the night and having trouble getting back to sleep. "Individuals who watched three or more hours of TV per day were about twice as likely as those who watched less than one hour of TV per day to have those two different kinds of sleep difficulties by the time they were young adults," he says. © ScienCentral, 2000- 2004.

Keyword: Sleep
Link ID: 5721 - Posted: 06.24.2010

By ANAHAD O'CONNOR Laurie Coots, a marketing executive who flies to meetings in other countries twice a week, spent years trying to conquer sleepless nights and chronic jet lag. But nothing worked, she says, and every day was a struggle to stay awake. "It was debilitating," said Ms. Coots, 46, who is from Los Angeles. "I couldn't give an effective presentation because I was always shaky and nervous from being amped up on caffeine and stimulants." Then she found modafinil, a small white pill that revs up the central nervous system without the jitteriness of caffeine or the addiction and euphoria of amphetamines. "Without it my life would not be possible," she said. Since 1998, modafinil, made by Cephalon and sold under the brand name Provigil, has quietly altered the lives of millions of people. No one knows exactly how it works, but sales of the drug are skyrocketing. Copyright 2004 The New York Times Company

Keyword: Sleep
Link ID: 5720 - Posted: 06.30.2004

Being called a bird-brain might not be so bad, after all. Canadian researchers have shown that humans just aren't cut out to discern certain pitches like their feathered friends. Testing completed on humans, rats, and three different species of birds shows that the birds--even ones that have been raised in isolation--are better at identifying, classifying, and memorizing absolute pitches than both humans and rats, with humans performing just slightly better than rats. "It's amazing how dissimilar the results of this test are when you compare humans and birds," said Dr. Chris Sturdy, a psychology professor at the University of Alberta. "Humans and rats are weak by any standard, and they're just awful when you compare them to the songbirds." For the study, humans were given monetary rewards when they memorized or recognized the pitches that were played for them, while the birds (zebra finches, white throated sparrows, and budgerigars) and rats were given food rewards. Sturdy said humans actually perform fairly well in tests of relative pitch, which refers to the relationship between two pitch sounds played one right after the other, allowing the listener to use one pitch as a reference for the other. However, when humans try to comprehend absolute pitch, which refers to pitches played alone without any external standard to contrast them with, their ability is "lackluster at best," he said.

Keyword: Hearing
Link ID: 5719 - Posted: 06.30.2004

Young women with a history of depression are twice as likely to have the metabolic syndrome, a cluster of symptoms that raise the risk of heart disease, according to a new study. Men with a similar history do not suffer as frequently from the same symptoms, writes Leslie S. Kinder, Ph.D., of the Veterans' Affairs Puget Sound Health Care System, in the journal Psychosomatic Medicine. "Perhaps the health risks linked to depression are more critical to women," Kinder says. Kinder and colleagues looked at results of a national health survey conducted between 1988 and 1994, covering more than 6,000 men and women ages 17 to 39. Women were more likely than men to have experienced a prior episode of depression, and those women who had had at least one episode were also more likely to suffer from the metabolic syndrome. People with the metabolic syndrome have at least three out of five factors linked to heart disease: high blood pressure; high triglycerides; low HDL (good) cholesterol; high fasting blood sugar; or abdominal obesity. "Depression in women was associated with the number of the metabolic syndrome components present," Kinder says, adding that the association between depression and high blood pressure was especially strong.

Keyword: Depression
Link ID: 5718 - Posted: 06.30.2004

Children who watch a lot of television produce less melatonin, new research suggests - the "sleep hormone" has been linked to timing of puberty. Scientists at the University of Florence in Italy found that when youngsters were deprived of their TV sets, computers and video games, their melatonin production increased by an average 30 per cent. “Girls are reaching puberty much earlier than in the 1950s. One reason is due to their average increase in weight; but another may be due to reduced levels of melatonin,” suggests Roberto Salti, who led the study. “Animal studies have shown that low melatonin levels have an important role in promoting an early onset of puberty.” Salti and colleagues studied 74 children aged between six and 12 years old, who normally watched an average three hours of television in the evening between 2000 and midnight. The youngsters, from the Tuscan town of Cavriglia, were encouraged to watch more TV than usual for a week preceding the study. © Copyright Reed Business Information Ltd.

Keyword: Hormones & Behavior; Development of the Brain
Link ID: 5717 - Posted: 06.24.2010