Monday, March 21, 2005

ClockNews #30: Miscellaneous Circadiana

Patterns within seemingly random events of physiological systems
In research on the dynamical features of the brief awakenings and sleep periods that occur in different mammalian species, the scientists found that the periods of wakefulness that snuggle between sleep periods of various mammalian species, are similar.

Night eaters
The University of Pennsylvania research has shown that the circadian cycle, 24-hour biological rhythm, for eating becomes disturbed in those with night eating syndrome, while their circadian cycle for sleeping does not. Imagine that your body's 24-hour cycle for eating and 24-hour cycle for sleeping were at odds with each other. This is the first disorder to be discovered in which the two biological rhythms have been dissociated, the researchers report. With the biological rhythm for food intake shifting to about six hours later than normal, sleep becomes more and more troubled by episodes of waking up hungry and stress builds.

Business Travel: A Good Flight's Sleep
Jet lag has been the bane of business travelers since the birth of international flight. But while aviation technology has advanced well beyond Charles Lindbergh's monoplane, a cure for "circadian-rhythm stress" has remained as elusive as a fix for the common cold.

The beneficial powers of darkness
According to a growing band of scientists and doctors, many of us are no longer getting enough darkness in our lives. The theory is based on a simple premise. Our biological rhythms evolved in a time before artificial light, to take advantage of both bright days and dark nights. By succumbing to the temptations of 24-hour living, and ignoring or reducing our natural dark time, we could be putting our health at risk.

Sleep Loss Deadly
According to a 2004 Circadian Technologies report, about 25 percent of night shift workers have Shift Work Sleep Disorder, a mismatch between required sleep-wake schedules and internal circadian clocks.Night shift work increases injury risk 23 percent and risk grows with consecutive nights worked.About 1.1 million men sleep less than 4.5 hours a day and about 1.1 million women sleep less than 3.5 hours a day, Birky said.It’s associated with a six-year mortality rate — "in six years, 15 percent are dead," he said.

The Circadian Clock: Understanding Nature's Timepiece
A cluster of brain cells less than half the size of a pencil eraser tells you when to wake up, when to be hungry and when it's time to go to sleep. The same cells also cause you to be disoriented after you've flown across multiple time zones.

13 things that do not make sense
Levin stands by his claim, and he is no longer alone. Joe Miller, a cell biologist at the University of Southern California in Los Angeles, has re-analysed the data and he thinks that the emissions show evidence of a circadian cycle. That is highly suggestive of life.

The dandelion: A worthy weed
Behaviorally, dandelions take after yet another cousin, the classic American sunflower. A spring day is well spent in the garden watching a dandelion tilt with perfect attentiveness as the sun crosses the sky. The flowers that open at dawn demurely fold up at dusk against the night chill. Why the dandelion should be such a graceful observer of the circadian clock, while other spring flowers such as the rose open and stay open, is anyone's guess. For this exquisite ritual alone, the dandelion flower is every bit as poetic as the rose, but useless to flower arrangers. Cut the flower, and it curls up and dies before a vase has been filled with water.

This St. Patrick's Day We Ask: Who's Drunk... and Who's Sleepy?
The guy on the next barstool may not have Guinness to blame for his slurred speech and impaired hand-eye coordination. He could be very, very sleepy. Data from CIRCADIAN, a Lexington, MA-based research and consulting firm, confirm a similarity in performance ability between someone who has been awake for 22 consecutive hours and someone with a blood alcohol count of 0.08 -- legally drunk in all 50 states.

Have asthma? Try working out in the afternoon
End-of-the-day workouts can relieve some of the huffing and puffing — at least for people with asthma. When researchers at Long Island Jewish Medical Center followed 4,835 people over a 5-year period, they found that lungs are strongest late in the afternoon.

Frank Hall architect Duffy intrigues University officials
Fawcett said SOM is also able to "mimic the beneficial effects of natural light" and therefore create a more appealing learning environment that "reinforces circadian rhythm."

Pilot fatigue: undefined safety menace
Flight does not involve much physical effort but the mental stress of being responsible for a safe flight, regardless of weather can be tiring. Sleep deprivation is an inherent thing for pilots who work on irregular hours. Printup said the nature of sleep is such that it follows circadian rhythms that run the biological clock of the human brain. It tells the brain to work during day and rest at night. Most pilots have variable schedules working several days on, then several days off. Long flight schedules thus disrupts the cycle or changes circadian rhythms causing fatigue to set in.

Keeping baby in the dark,,8124-1520013,00.html
The only potential problem could be that a light at night might alter a baby’s circadian rhythm, which governs normal sleep cycles. It would have to be very bright, though. In general, plug-in night lights are too low in intensity to cause problems.

"Wal-Mart Amendment" Discounts Danger of Tired Truckers; Creates Sweatshops on Wheels with 16-Hour Workdays
We believe that a final rule should allow no more than 10 consecutive hours of driving time, and no more than 14 hours of on-duty time in each shift, with at least 10 hours of rest each day and a full weekend off work. The workday for drivers should follow the circadian cycle – or a 24-hour day – as opposed to the 21-hour shift rotation permitted under the 2003 vacated standard.

Studies clash on safety impact of hours rule
The 34-hour recovery and restart help to avoid the shifting of daytime to nighttime schedules, which can affect the circadian rhythm and decrease alertness.

Volunteers help solve puzzle of circadian clock
New research at Massey University will provide another piece in the puzzle of why some people are a "morning person" and others a "night person".


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