Waltham, MA —A Brandeis University study published in Cell this week shows for the first time experimentally that the circadian cells in fruit flies function as a network that enables the insects to adapt their behavior according to seasonal changes. This discovery leads the way to understanding how mammals, and presumably humans, adjust physiology and behavior to environmental changes such as short winter days and long summer ones. For years, behavioral geneticists have known that specific brain cells in Drosophila fruit flies regulate the daily rhythmic behavior according to 24-hour endogenous clock machinery. But until now, scientists had offered only mathematical models to explain how fruit flies and other animals, including humans, adapt to seasonal changes such as fluctuating day length and temperature. "In this study we show how the 24-hour intrinsic molecular clock can produce a variable output, so that it fits any seasonal condition," said lead author Dan Stoleru. "This is especially exciting because it gives us an understanding of how animals extract vital information from the environment to drive innate behavior such as reproduction, migration or hibernation." Stoleru, a researcher in the pioneering National Center for Behavioral Genomics lab led by Michael Rosbash, explained that this property is provided by an adaptable brain circuit of oscillating neurons, capable of responding specifically to different environmental cues.

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 10160 - Posted: 06.24.2010

Ben Harder This time of year, the wilds of North America are relatively quiet. The black bears that usually patrol the woods seem to have vanished. Many bat species are nowhere to be found, at least not by the causal observer. The same is true of ground squirrels and chipmunks. They are hidden away—hibernating. Biologists have been intrigued for decades about how animals go dormant during the winter and survive physiological conditions that would kill them at other times of the year. Hibernators spend most of the winter in torpor, a state of self-induced reduction in body temperature and metabolic rate. Even some species that don't contend with harsh winters by hunkering down for months at a stretch, such as mice, enter torpor daily when food is in limited supply and temperatures are chilly. Many small birds spend nights year-round in torpor. In mammals, hibernation is so widespread that researchers reason that the ancestor of all mammals must have been a hibernator. People may be physiologically capable of tapping this dram of evolutionary heritage, says molecular biologist Sandra Martin of the University of Colorado School of Medicine in Aurora. If people could mimic certain aspects of hibernation, they might benefit greatly. For instance, inducing a torporlike state in a wounded soldier or a bleeding-accident victim might give doctors precious extra time to stop and reverse the damage. Other patients would benefit if donated organs could be put in cold storage for prolonged shelf lives. And for astronauts, torpor, which some people call suspended animation, might facilitate travel to distant planets. ©2007 Science Service.

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 9891 - Posted: 06.24.2010

Mice tend to do most of their scampering about at night, resting up during the day for the evening's activity. But fiddle with a single gene, and suddenly the animals are much livelier during daylight hours. The shift in activity in these genetically engineered mice turns out to be more than a mere nuisance to the animals' slumbering cage mates - it's helping scientists illuminate the fundamentals of biological clocks, as well as a circadian rhythm disorder that affects a small number of humans. People with familial advanced sleep-phase syndrome (FASPS) tend to become sleepy and wake up earlier than most. They are often ready for bed around 7:30 in the evening, and ready to begin their day at 4:30 in the morning. People with FASPS—a disorder caused by alterations in a single gene—also have a shorter circadian period than those without the altered gene. Howard Hughes Medical Institute researchers have now demonstrated that mutating the same gene in mice has the same effects. A mouse model that mimics the sleep-wake patterns of human FASPS offers new opportunities to understand how biological clocks govern these cycles, as well as a wide range of physiological functions. Louis J. Ptacek and his colleagues reported their first studies on the mutant mouse strain in an article in the January 12, 2007, issue of the journal Cell. The mouse they developed harbors a mutant version of the human gene Period 2 (hPer2), which Ptacek and his colleagues had found in earlier studies to be responsible for familial advanced sleep-phase syndrome (FASPS). When the researchers analyzed the activity patterns of the gene-altered mice, they found that the animals showed a shorter circadian period and a shift in their sleep-wake cycle equivalent to humans with FASPS. © 2007 Howard Hughes Medical Institute

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 9834 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — Not a morning person? Take solace — new research suggests that "night owls" are more likely to be creative thinkers. Scientists can't yet fully explain why evening types appear to be more creative, but they suggest it could be an adaptation to living outside of the norm. "Being in a situation which diverges from conventional habit — nocturnal types often experience this situation — may encourage the development of a non-conventional spirit and of the ability to find alternative and original solutions," lead author Marina Giampietro and colleague G.M. Cavallera wrote in a study to be published in the February 2007 issue of Personality and Individual Differences. The researchers, who are both in the Department of Psychology at the Catholic University of the Sacred Heart in Milan, Italy, studied 120 men and women of varying ages. A self-report questionnaire evaluated degrees of morning and evening dispositions. In fact, true morning and evening-oriented people are actually rare, since most of us fall somewhere in between. Once the subjects were categorized into either morning, evening or intermediate types, they underwent three tests designed to measure creative thinking. © 2006 Discovery Communications Inc.

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 9729 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — Seasonal changes cause fat to shift locations in our body, thus altering the shape of our figures at certain times of the year, according to a new study. Varying testosterone levels drive the shape changes, the study suggests. The hormone, often associated with brawn and aggressiveness, fluctuates over the seasons in both men and women. The most evident changes occur within the waist and hip region, the study determined. When testosterone levels rose, women became less curvy as fat shifted toward the waist. Other research has determined that the opposite happens in men, who retain more fat in the abdominal region when testosterone levels fall. The scientists examined seasonal testosterone fluctuations in the saliva of 220 women and 127 men. They also measured the waists and hips of the female study participants over the seasons. "We found that women’s and men’s testosterone is highest in the fall," said Sari van Anders, who led the research. "As well, women’s waist-to-hip ratio (how big the waist is relative to the hips) is highest during the fall, and central measures of fat deposition, like abdominal fat, were also somewhat higher in the fall (for women)." © 2006 Discovery Communications Inc.

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 13: Homeostasis: Active Regulation of Internal States
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 9026 - Posted: 06.24.2010

Janet Raloff Erin Chesky was a sleep-troubled teen, typical of many. Despite going to bed early each night, this honor roll student struggled to doze off—sometimes lying awake until 3 a.m. Each morning, she fought equally hard to wake up at 5:30, in time to eat breakfast and catch the school bus. Forever tired, "I was like a zombie," she recalls. Last fall, a sleep specialist examined the 17-year-old from Colonie, N.Y. He diagnosed her with delayed sleep-phase syndrome, a condition in which the body's internal clock fails to synchronize appropriately with Earth's day-night cycle, which changes a few minutes each day. From birth, Erin and her siblings were night owls. When Erin turned 15 however, her biological clock really got off-kilter, triggering insomnia that threatened her schoolwork. Her mom recognized the affliction; it had struck her at the same age. For such teens, adhering to class schedules can be "like swimming upstream," says psychologist Paul Glovinsky of the Capital Region Sleep and Wake Disorders Center at St. Peter's Hospital in Albany, N.Y. Some teens fail to make it to school on time, or at all, 30 or more days a year. Copyright ©2006 Science Service

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 7: Vision: From Eye to Brain
Link ID: 8974 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — Many reptiles in the wild can survive for days, even when over half of their body water is frozen, and now scientists have identified three groups of genes that help keep these animals from sustaining damage or death during this near-Popsicle condition. The discovery not only helps to solve the reptile freezing mystery, but scientists also hope the research could one day lead to improved methods for freezing human cells and organs so that tissues in cryostorage could remain alive and viable after thawing. When the temperature dips, some reptiles cannot escape to warmer areas, so several species instead have evolved incredible tolerance to cold. "Over the past 20 or more years of working in the field, various researchers, including ourselves, have come to realize that animals that survive long-term freezing as an integral part of their winter survival strategy have to be able to deal with ice penetration throughout their whole body and with the many consequences of this, including blood plasma freezing, heart beat and breathing stopping, etc.," said Janet Storey, a research associate at Carleton University's Institute of Biochemistry in Canada. © 2006 Discovery Communications Inc.

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 13: Homeostasis: Active Regulation of Internal States
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 8634 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — Many humans suffer from depression during the winter months, and now scientists have determined that hamsters also may experience anxiety and depression during the dark days of the year. The researchers also discovered that female hamsters and hamsters born during winter months tended to exhibit more seasonal mood swings later in life. Since the likely mechanisms behind these feelings also exist in humans, the findings may lead to better diagnosis and treatment for anxiety and depression. The study's results also suggest that many other species feel depressed, and get especially bummed out during the winter, because of reduced sunlight. In humans, the winter condition is named SAD, which stands for Seasonal Affective Disorder. "Based on the similarities between day length-induced depressive and anxiety-like behaviors in hamsters and Seasonal Affective Disorder in humans, it is possible that there are similar mechanisms or adaptive value in seasonal depression among many species," said authors Leah Pyter and Randy Nelson, researchers in the Departments of Neuroscience and Psychology and the Institute of Behavioral Medicine Research at Ohio State University. © 2005 Discovery Communications Inc

Related chapters from BP6e: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders; Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders; Chapter 10: Biological Rhythms and Sleep
Link ID: 8203 - Posted: 06.24.2010

Diana Lutz The Velocity of Honey's 24 chapters are short meditations on questions that are probably never going to make the cover of Science or Nature, such as why toast falls butter side down and why time seems to speed up as we grow older. You might call them crossword puzzles for the scientifically minded—they offer a mental workout for its own sake but also soothe and amuse. In fact, author Jay Ingram calls The Velocity of Honey "a self-help book." Its essays "reduce stress," he says, and offer "a brief interruption in the ridiculous rush of life." Ingram, who hosts the Discovery Channel's science program Daily Planet, says he picked the topics for their appeal—adding with characteristic self-irony that this means their appeal to him. Somehow, he says, that turned out to mean there is a lot of physics and psychology and not much in between. (Ingram himself has a master's degree in microbiology from the University of Toronto.) The physics chapters include, in addition to tumbling toast, essays on the way paper crumples and crackles when it is squeezed, the aerodynamics of the maple key (the thin fibrous "wing" that encases the maple seed), the tricky behavior of stones thrown slantwise across water or sand, and the motion across ice of the 20-kilo granite "rocks" used in the sport of curling. © Sigma Xi, The Scientific Research Society

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 15: Language and Our Divided Brain
Link ID: 8144 - Posted: 06.24.2010

A few rare people who consistently nod off early, then wake up wide-eyed much before dawn, can blame a newly-found mutant gene for their sleep troubles, Howard Hughes Medical Institute researchers announced today. This odd “time-shift” trait — called familial advanced sleep phase syndrome (FASPS) — was studied in one affected family by neurologist Louis J. Ptacek, a Howard Hughes Medical Institute researcher, and Ying-Hui Fu, at the University of California, San Francisco. Their report appears in the March 31, 2005, issue of the journal Nature. The sleep-shifting mutation they found is in “a gene that was not previously shown in mammals to be a circadian rhythm gene,” Ptacek explained. It's not yet clear how the mutant gene works to shift people's sleep time, their circadian rhythm, he added. But follow-on experiments in fruit flies and mice yielded results that are intriguing. When the mutant gene was inserted into the flies, for example, it did the opposite of what was seen in the human family: it lengthened circadian rhythm. Yet in genetically engineered mice, the same gene change made the mice early risers — mimicking what was seen in humans with FASPS. © 2005 Howard Hughes Medical Institute.

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 7113 - Posted: 06.24.2010

Ben Harder In 1988, physician and amateur moth enthusiast Kenneth D. Frank published a scientific paper that pulled together much of what researchers then knew about the consequences of artificial night-time lighting on moths. That paper is the closest thing the nascent field of artificial-light ecology has to a classic work. It didn't exactly trigger the response one might expect from a seminal study, however. The report has received precious little attention and stimulated no immediate cascade of follow-up research. Frank recently searched the scientific literature to count how many subsequent papers had made reference to his study—and found exactly one. Nevertheless, Frank and a handful of other scientists are endeavoring to synthesize a coherent understanding of the ecological impacts of artificial light on a multitude of organisms. These efforts are gradually gaining momentum. From anecdotal reports of little-studied phenomena—such as moths' tendency to perish, Icarus-style, in lamps and flames—researchers suspect that artificial night lighting disrupts the physiology and behavior of nocturnal animals. In many cases, scientists have few reliable data on which to rest conclusions—but every reason to be concerned. From Science News, Vol. 161, No. 16, April 20, 2002, p. 248. Copyright ©2002 Science Service. All rights reserved.

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 1923 - Posted: 06.24.2010

John Pickrell As dawn breaks on a misty Welsh morning, the earliest birds to break into song are likely to include European robins, followed by blackbirds and song thrushes and then a plethora of other species as sunlight crowns the horizon. The last to join the chorus, such as chaffinches and blue tits, may not chime in until 100 minutes after the first crooners began. This pattern is repeated worldwide, and ornithologists have often pondered what determines when a particular species begins its morning singing. Now, scientists say that they've found the explanation: The larger a bird's eyes, the earlier it starts to sing. The staggering of avian choruses was first documented 70 years ago but has remained unexplained. Now, researchers have revisited an idea first proposed in the 1960s but never tested. It's that visual acuity—determined by eye size—governs when birds start to sing. From Science News, Vol. 161, No. 16, April 20, 2002, p. 245. Copyright ©2002 Science Service. All rights reserved.

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 8: Hormones and Sex
Link ID: 1922 - Posted: 06.24.2010

by Gretchen Vogel If you’re reading this at night, beware: You may be affecting your body’s internal clock. Humans, like other animals, rely on light cues to set their body's daily cycle of activity, or circadian rhythm. Now a new study shows that some wavelengths of light, such as those from computer screens, have an unexpectedly strong influence on these rhythms, keeping us awake, for example, when we should be sleeping. In mammals, a well-tuned system of light-sensing cells regulates the area of the brain that controls circadian rhythms, including those governing alertness and hunger. In diurnal animals, for example, light suppresses the production of the hormone melatonin, which is released during the night and promotes sleep. Researchers once thought that the eye’s rod and cone cells, which allow us to see, were responsible for detecting these light cues. But in some blind mice and blind people, circadian rhythms respond normally to changes in light exposure. Scientists now suspect that neurons in the retina that contain melanopsin, a pigment that is sensitive to short-wavelength blue light, drive circadian signals; these cells are still functional in blind people whose body clocks respond to light and dark signals. As a result, some researchers have recommended blue-light therapy for seasonal affective disorder, a type of depression triggered by winter’s short days. Others have developed blue light-blocking goggles to help insomniacs sleep better. But a new study of the specific effects of blue and green light suggests that the real story is more complicated. Neuroscientist Steven Lockley of Brigham and Women’s Hospital in Boston and his colleagues studied how exposure to different levels of light affected the sleep of healthy human volunteers, too. © 2010 American Association for the Advancement of Science

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 7: Vision: From Eye to Brain
Link ID: 14069 - Posted: 06.24.2010

By RONI CARYN RABIN There are probably better ways to start the day, but a new study suggests that early morning is an ideal time to schedule a colonoscopy. Physicians detected 20 percent more polyps during the first procedures of the day than they did during procedures performed later in the morning and the early afternoon, the study found. “Hour by hour, there were fewer polyps found as the day progressed,” said Dr. Brennan M. R. Spiegel, an assistant professor of medicine at U.C.L.A. and an author of the study, which appears in the November issue of the journal Clinical Gastroenterology and Hepatology. “It’s a small effect, very small, but very measurable and definitely there.” A study done at the Cleveland Clinic and published this year found similar results, noting that 29.3 percent of morning procedures resulted in detection of at least one polyp, compared with 25.3 percent of the afternoon procedures. The new study looked at the results from colonoscopies performed on 477 patients at the West Los Angeles Veterans Medical Center in 2006 and 2007. Most of the procedures were performed by a physician training in gastroenterology who was supervised by a faculty member. Procedures were performed between 7:45 a.m. and 1 p.m., and though they were done only in the early hours of the day, the analysis found that 20 percent more polyps were detected during the earliest colonoscopies. The researchers tried to control for other factors that might have affected the results, including the fact that patients usually came in with better bowel preparation for morning procedures. Copyright 2009 The New York Times Company

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 15: Language and Our Divided Brain
Link ID: 13465 - Posted: 06.24.2010

By Tina Hesman Saey Plants do shift work too. Researchers have now discovered an important worker on the second shift. Jose Pruneda-Paz, Steve A. Kay and their colleagues at the University of California, San Diego report in the March 13 Science that they have found a missing link in plants’ circadian clocks. A regulatory protein called CHE connects a morning cycle to an evening cycle. Daily rhythms in plants, animals and microorganisms are governed by circadian clocks. Even though the clocks keep time in much the same way, the genes and proteins that make up the gears differ. Scientists are still uncovering all the gears of plants’ clocks. Plants have a large number of regulatory proteins, called transcription factors, which wind the clock and keep it running on time. These transcription factors are organized in multiple feedback loops that help make timing more precise, Kay says. People used to think of the circadian clock as a simple circle, but no more. “All of a sudden it’s turned into something that looks like the Olympic flag, multiple interlocking loops,” Kay says. Scientists previously discovered that the morning shift in plants is governed by a protein known as CCA1, and the night shift is under control of TOC1. But researchers didn’t know who punched the clock on the second shift. © Society for Science & the Public 2000 - 2009

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 12644 - Posted: 06.24.2010

by Jack Penland For years, scientists have seen a link between odd hours and health-threatening conditions such as diabetes and cardiovascular disease, but, according to Frank Scheer of Boston’s Brigham and Women’s Hospital and Harvard Medical School, “The underlying mechanism was not well understood.” “What we wanted to know,” says Scheer, was if living hours opposite from your internal body clock “would lead to physiological changes that may in the long run lead to increased risk for obesity, diabetes and cardiovascular disease.” Scheer and Steven Shea, also with Boston’s Brigham and Women’s Hospital and Harvard Medical school, led a team that inverted the hours of ten volunteers over ten days. He says, “We were struck actually by the speed of the changes that we observed.” During the testing the scientists took hourly measurements of blood sugar and hormones such as leptin, which is important in regulating someone’s appetite and body weight. He added, “Even within a few days we observed quite dramatic changes in all these hormone systems.” The results went so far that, “three of the individuals showed blood glucose levels which were consistent with a pre-diabetic state.” In a clinical setting, ten young, healthy and normal-weight volunteers agreed to be tested over ten days. The first two were normal days where blood samples were taken and baseline blood sugar and hormone levels established. Over the next eight days the volunteers lived 28-hour days. In other words, if the normal wake time was 7 am and bed time 11 pm, then it was shifted to waking at 11 am and sleeping at 3 am on the first day, waking at 3 pm on the second and sleeping at 7 am on the third and so on until they were back to a regular day. ©2009 ScienCentral

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 12606 - Posted: 06.24.2010

By Tina Hesman Saey Timing is everything, especially when it comes to basic biological functions such as eating, sleeping and detoxifying. Scientists have known for ages that metabolism is tied to the body’s daily rhythms, but have not known how. Now, two groups of researchers report in the July 25 Cell the discovery of a molecule that links metabolism to the circadian clock. The missing link turns out to be a protein called sirtuin 1 or SIRT1, which is also a key regulator of aging. Uncovering the mechanism that links metabolism and circadian rhythms could lead to drugs to combat obesity, aging and jetlag and help shift workers reset their body clocks. Already, SIRT1 is the target of resveratrol, a molecule found in red wine and other foods and that mimics the health benefits of a nutritious, calorie-restricted diet. “It’s an interesting connection,” says Herman Wijnen, a circadian geneticist at the University of Virginia in Charlottesville who was not involved in the new studies. “It helps us understand one important aspect of how clocks and metabolism relate to each other.” Body rhythms are governed by molecular clocks that take about a day to complete a full cycle, hence the name circadian clock. The clocks are composed of proteins whose concentrations or levels of activity rise and fall like the tide. © Society for Science & the Public 2000 - 2008

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 11861 - Posted: 06.24.2010

Andy Coghlan An internal clock hidden in human skin cells could reveal whether your body clock is out of sync with your lifestyle, say researchers. Steven Brown of the University of Zurich in Switzerland and his colleagues knew that the brain’s circadian clock causes a gene called Bmal1 to be more active in the body’s other cells during the daytime. To find out how closely matched this activity was, they used a virus to equip skin cells taken from 11 early-rising people dubbed "larks" and 17 late-rising "owls" with a firefly gene that would produce a visible glow whenever Bmal1 was active. “The result is light coming out of the cell in a 24-hour rhythm,” says Brown. By monitoring the times when the cells glowed, they demonstrated that skin cells showed the same sleep-wake patterns as those reported in questionnaires by at least half the donors. There were discrepancies too, however, most notably in three individuals with seasonal affective disorder. This suggested that skin biopsies might be useful for diagnosing sleep and circadian disorders. © Copyright Reed Business Information Ltd

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 11247 - Posted: 06.24.2010

By William J. Kole VIENNA, Austria - Ever whacked your thumb with a hammer, or wrenched your back after lifting a heavy box, and blamed the full moon? It’s a popular notion, but there’s no cosmic connection, Austrian government researchers said Tuesday. Robert Seeberger, a physicist and astronomer at the Ministry of Economic Affairs, said a team of experts analyzed 500,000 industrial accidents in Austria between 2000 and 2004 and found no link to lunar activity. “The full moon does not unfavorably affect the likelihood of an accident,” Seeberger said. The study, released Tuesday by the General Accident Insurance Office, said that on average there were 415 workplace accidents registered per day. Yet on days when the moon was full, the average actually dipped to 385, though the difference was not statistically significant. The lunar influence theory dates at least to the first century A.D., when the Roman scholar Pliny the Elder wrote that his observations suggested “the moon produces drowsiness and stupor in those who sleep outside beneath her beams.” Seeberger, who advises the Austrian government on accident prevention, said he and fellow researcher Manfred Huber decided to take a closer look because the full moon theory kept surfacing “again and again.” © 2007 MSNBC.com © 2007 Microsoft

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep
Link ID: 10558 - Posted: 06.24.2010

By ERIC NAGOURNEY Researchers have found that different kinds of strokes are more likely to occur at different times of day, perhaps because of the body’s natural clock. Writing in The Journal of Neurology, Neurosurgery & Psychiatry, the researchers reported that three types of stroke all had two peak periods during the day: in the morning and in the evening. But the researchers, led by Dr. Shinichi Omama of Iwate Medical University in Japan, found that the peaks were not uniform. Occurrence of the most common type of stroke, for example, in which blood flow to the brain is cut off, peaked in the morning. Occurrence of the two other kinds, which involve bleeding in the brain or, more rarely, at its surface, peaked in the afternoon. The researchers reviewed first-time strokes among about 13,000 people from 1991 to 1996. Bleeding and clotting strokes have similar triggers, the researchers said, leading to questions about why the occurrence would vary with the hour of the day. Some research has shown that the blood is more prone to clotting in the morning, which may promote the second type of stroke and inhibit the first. The study also found that, over all, strokes are least likely to occur during sleep because blood pressure, a trigger, is lower then. Still, low blood pressure is also a trigger for clotting strokes. Copyright 2006 The New York Times Company

Related chapters from BP6e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 15: Language and Our Divided Brain
Link ID: 9279 - Posted: 06.24.2010