Thursday, April 07, 2005

ClockNews #31: Daylight Savings Etc.

Altering Food and Light Schedules Affects Cancer Genes in Mice

A new study has found that altering food schedules and light/dark exposure in mice modified the expressi on of circadian clock genes and genes involved in carcinogenesis and tumor progression.

The circadian clock regulates the approximate 24-hour cycles of many animals, including mammals. It has been reported that tumors grow faster in animals with a disr u pted circadian clock--which happens, for example, in chronic jet lag--but the molecular mechanism is unclear.

Francis Lévi, M.D., Ph.D., of the French National Institute of Health and Medical Research (INSERM) and University Paris XI at Paul Brousse Hos pital in Villejuif, France, and colleagues compared the expression patterns of circadian clock and cell cycle genes in the livers and tumors of mice synchronized by normal light and dark schedules (normal circadian clock) or with schedules designed to sim ulate chronic jet lag in humans (disrupted circadian clock). They found that meal timing reversed the disrupted circadian clock gene expression patterns and slowed tumor growth in chronic jet lagged mice. The authors conclude that the altered light/da rk o r feeding schedules modified the carcinogenesis and tumor progression.

Mutant gene cause of sleep disorder

A mutant gene behind an "early b ird" sleep disorder has been identified by American researchers. Approximately three-tenths of a percent of the world's population has familial advanced sleep phase syndrome (FASPS), according to the researchers. People with this "time-shift" trai t have b ody clocks that are out of sync with most of the world. Researchers say they have found the genetic culprit for this rare sleep disorder.

People with this sleep disorder do not suffer from sleep deprivation. Rather, they consistently fall asle e p at an early hour and then wake up well before dawn.

Melatonin for jet lag stirs discussion

THE CLAIM: Melatonin can help you conquer jet lag.
T HE FACTS: Some bleary-eyed travelers swear by melatonin as a way to beat jet lag. But experts say research on the hormone's effectiveness is far from clear-cut.

Chronically tired? Or irritable? Maybe it's due to too little sleep

"Many people feel that sleeping is a waste of time, but more are realizing that it's essential to health and well-being," said Sreden.

Daylight Savings Time is a case in point. The day after Americans "spring ahead," a statistical blip occurs in which automobile crashes increase as drivers losing an hour of sleep suffer impaired driving abilities, according to Sreden.

Quiet suffering

Driving while drowsy is a potentially
deadly combination, akin to driving under
the influence of alcohol. Driving
performance after 19 hours of sustained
wakefulness is comparable to driving with
a blood alcohol concentration (BAC) of
0.05 per cent; after 24 hours, the
equivalent to a person with a BAC of 0.10
per cent.

Physicists Find Patterns Within Seemingly Random Events Of Physiological Systems

Finding patterns behind seemingly random events is the signature of a recent trio of research studies coming from the statistical physics group in Boston Universit y's industry for research physicists, findings from this BU group increasingly wed phenomena associated with the inanimate world to those of animate beings -- finding commonalities between stock markets fluctuations, earthquakes, and heart rates, for exam ple, or discovering similarities in mice, men, and other mammals for such fundamental phenomena as wake periods during slumber.

Valdoxan®: A New Approach to The Treatment of Depression

Due to its unique pharmacological profile, Valdoxan is the only antidepressant to have a specific action on circadian rhythms, which are often imbalanced in depressed patients. By improving disturbed wake-sleep patterns, according to Dr Guilleminault, Valdoxan is a bleto relieve sleep complaints of depressed patients with a favourable impact on daytime vigilance.

Respironics Acquires Mini-Mitter Company, Inc., Sleep and Phy siological Monitoring Device Innovator

Mini Mitter develops and markets a range of physiological monitoring products, including devices that measure sleep-wake activity, dermal and core body temperature, heart rate, and energy expenditure.

Oh-oh! I better check if they'll keep making the equipment I use....

Early Bird Sleep Disorder Linked To Mutant Gene

Researchers believe a mutant gene may be responsible for a sleeping disorder that causes people to nod off early, then wake up wide-eyed long before the sun rises.

Why must we spring forward?

Spring forward, fall back.

OK, that memory device helps us recall that we need to set our clocks one hour forward when we go to bed tonight so we'll wake up in sync with daylight-saving time on Sunday. But it also reminds us that if we set th e alarm at our normal time to go to church, we'll be short an hour's sleep.

Worse, we don't get that hour back until the last Sunday in October.

It may not take seven months for us to get used to the new time scheme, but the folks at Circadian, an inter national r esearch and consulting firm, estimate that it does take a couple days for our bodies to adapt to the change.

So, why do we put up with this nuisance? Well, Ben Franklin first proposed daylight-saving time in 1784, but Americans didn't adopt it until Worl d War I to save energy. It worked but proved so unpopular that the country went back to what irritated farmers called "God's time" in 1920. DST returned in World War II, when U.S. clocks were set ahead one hour ye ar-round. After the war, some jurisdiction s continued DST and others abandoned it. Congress later passed the Uniform Time Act of 1966, which doesn't require anyone to observe daylight-saving time, but sets rules for those who do. DST is not observed in Hawaii, American Samoa, Guam, Puerto Rico, t he Virgin I slands, the Eastern Time Zone portion of the Indiana, and by most of Arizona (with the exception of the Navajo Indian Reservation).

The Department of Energy estimates DST reduces electricity use by about 1 percent a day, mainly by reducing th e need for l ighting in evening hours. Some people now argue for year-round DST, but critics say that wastes as much energy on dark winter mornings as it saves in the evening. Russia, further north than the U.S., stays on DST all year and g oes to double-d aylight in the summer.

If you really hate daylight time, you can avoid it by moving to Panama. Equatorial countries don't observe it since their daylight hours don't vary much. If you love it, you can get a double dose by moving to Russi a. For most of u s, the best course is to go to bed a little early Sunday night so our bodies don't show up for work an hour late on Monday.

Scient ists Find Gene that Controls I n somnia

As the saying goes, early to bed, early to rise. But in the world of sleep researchers, that's a disorder as much as the syndrome experienced by people who stay up very late and sleep very late into the morning.

Time Change May Put Sleepier Drivers on Road

Sleep scientists analyzing data from 21 years of car crashes concluded in 2001 that the numbe r of fatal collisions increased slightly on the Sunday and Monday after the switch to daylight saving time. When standard time returns in the fall and clocks are turned back an hour, researchers Jason Varughese of Stanford and Richard P. Allen of Johns Ho pk ins wrote, there also were more accidents, possibly because people were staying out later the Saturday night before.
During daylight saving time, the study showed, the extra hour of sunlight typically occurr ed during peak traffic periods an d c ut the number of fatalities even further. The biggest reduction was in the number of pedestrian deaths, because drivers were better able to see people walking in the street.

Caffeine - are you addicted?

Scientists have claimed that, like methadone users, those who feel they cannot function without a morning coffee may be trying to “stave off withdrawal symptoms”.

Scientists also claim caffeine stimulates the brain in the same way as amphetamines, cocaine and heroin and could be classified as an addictive drug.
Caffeine keeps us awake by blocking the effects of the chemical adenosine, whic h causes us to feel sleepy.

Ad enosine attaches to receptors in the brain and slows down the activity of nerve cells.

Caffeine attaches itself to the same receptors: blocking adenosine, increasing brain cell activity, and producing the buzz obtained from drinking a caffeine-laced b rew.

2:00 A.M. Was Overrated Anyway: Company Offers 12 Reasons to Celebrate Losing an Hour This Weekend

1. Technically speaking, you'll get 13 hours out of your 12-hour cold pill

2. Grogginess is a great excuse for avoiding the in-laws

3. The one person in the house who knows how to re-set the VCR clock gets
a chance to strut his stuff

4. It's one fewer hour of having to lay sl eepless next to yo ur snoring

Scientists use lasers to control flies

Mutant gene s hifts when people a re sleepy

Students lose in sleep cost-benefit ana lysis


Waking up to sleep problems

UCSF study offers insight into human circadian rhythms

Clockwork internalXXÏÏ


Post a Comment

<< Home

Science & fun cool stuff
Circle of Science Assessment
Join | List | Previous | Next | Random | Previous 5 | Next 5 | Skip Previous | Skip Next

The Evolution Education Site Ring

This site ring is owned by John Stear

Previous Site

List Sites

Random Site

Join Ring

Next Site

SiteRing by