sleep
edyong | May 4, 2009Most of us start to tire after about half a day without any sleep. Staying awake for five in a row would be extremely difficult and even if you could manage it, you'd be a physical and mental wreck by the end. But not all animals suffer from the same problem. A dolphin can stay awake and alert for at least 5 days straight, chaining together all-nighters without any noticeable health problems or loss of mental agility.
The two halves of a dolphin's brain can sleep in shifts, "shutting down" one at a time so that the animal is always half-awake. They can truly sleep with one eye open, an…
clock | April 16, 2009Ask the pilot:
Ask yourself this: Whom would you prefer at the controls of your plane on a stormy night, a pilot who smoked a joint three days ago, or one who had six hours of sleep prior to a 13-hour workday in which he's performed half a dozen takeoffs and landings? The first pilot has indulged in a career-ending toke; the second is in full compliance with the rules. I have to assume that the FAA realizes the foolery of such enforcement policies, but it nonetheless chooses to put its resources into drug testing and other politically expedient issues. Meanwhile it procrastinates, performing…
clock | April 2, 2009Nice four articles:
The Gears of the Sleep Clock By Allan Pack:
When people have trouble sleeping--such as, in extreme cases, shift workers--those problems are not always rooted in disturbances in circadian rhythm, argues the University of Pennsylvania's ALLAN PACK. Instead, his studies of sleep have shown that the master clock is only one player in the molecular control of sleep.
Sleep adjusts fly synapses by Bob Grant:
New findings support a controversial hypothesis about the biological role of sleep: Snoozing may be a way for the brain to clear clutter accumulated after a hard day of…
clock | March 7, 2009Yup, it's tonight.
If you were around here a few months ago, the day after the Fall Back day, you probably read this post.
Disregarding the debate over rhetoric of science, that is probably my best, most detailed explanation for what happens to our bodies on those too strange days of the year - Spring Forward and Fall Back day.
Spring Forward is much more dangerous, so be very careful in the mornings next week, especially on Monday. Take it easy, get up slowly, be a little late for work if you can afford it. Life and health are more important than a few minutes of work and being punctual on…
clock | February 24, 2009SLEEP 2009:
23rd Annual Meeting of the Associated Professional Sleep Societies, LLC (APSS) will be held June 6-11, 2009, at the Washington State Convention and Trade Center in Seattle, Washington. The SLEEP meeting attracts the largest audience of sleep specialists in the nation. It is the only five and a half day meeting in the nation with scientific sessions and an exhibition hall focused solely on sleep medicine and sleep research.
Hmmm, always wanted to visit Seattle. And this sounds like a very bloggable conference. And I'd get to finally meet Archy....
clock | February 6, 2009This month's Science Cafe (description below) will be held on February 17th at The Irregardless Cafe. We will be meeting Dr. Yvette Cook from the Rex Hospital Sleep Disorders Clinic. She will be talking with us about sleep patterns and why people may have trouble getting a good night's sleep. I have attached an article Dr. Cook recently wrote for a Rex Healthcare newsletter that you may find of interest. I hope that many of you can come - it should be a very interesting and informative discussion.
Sleep and Sleep Disorders
Tuesday, February 17, 2009
6:30-8:30 pm with discussion beginning…
clock | January 13, 2009Chemotherapy Most Effective At Time Of Day When Particular Enzyme At Lowest Level:
For years, research has hinted that the time of day that cancer patients receive chemotherapy can impact their chances of survival. But the lack of a clear scientific explanation for this finding has kept clinicians from considering timing as a factor in treatment. Now, a new study from the University of North Carolina at Chapel Hill has suggested that treatment is most effective at certain times of day because that is when a particular enzyme system - one that can reverse the actions of chemotherapeutic drugs…
clock | November 26, 2008It's Thanksgiving tomorrow and the question (of the title of this post) pops up on the internets again. See SciCurious and Janet for the latest local offerings.
Short answer: we don't know.
But there is endless speculation about it, each taking into account bits and pieces of information that we know about tryptophan and related physiology. The hypotheses tend to focus on:
a) Tryptophan itself, i.e., how it can get from food, through the intestine, through the bloodstream, to the brain and what it would do once there.
b) Serotonin, as a product of tryptophan metabolism, and how it can be…
clock | November 13, 2008Here are a few examples. One will feed you greasy bacon every morning. The other will donate to the GOP. Others will force you to perform either menial or mental tasks. I prefer a more gradual approach - a system that gradually increases the illumination in the room, the volume of sound (some pre-chosen music), etc. and only does something dramatic at the last, most critical point in time when you absolutely HAVE to get up.
more animals
[btw, check out the other pages on that site - there are some other cool inventions there, mixed up with some quite silly ones]
clock | November 2, 2008If you live in (most places in) the United States as well as many other countries, you have reset your clocks back by one hour last night (or last week). How will that affect you and other people?
One possibility is that you are less likely to suffer a heart attack tomorrow morning than on any other Monday of the year. Why? Let me try to explain in as simple way as possible (hoping that oversimplification will not lead to intolerable degrees of inaccuracy).
Almost all biochemical, physiological and behavioral parameters in almost all (at least multicellular) organisms display diurnal (daily…
purepedantry | October 31, 2008This Sunday you are slightly less likely to have a heart attack.
Swedish researchers, publishing in the NEJM, looked at a registry of heart attacks from 1987 to 2006. They found that the incidence of heart attacks slightly increases for the three days following the Spring daylight savings time where we lose an hour. The incidence of heart attacks slightly decreased on the day after Fall daylight savings time:
We used data from the Swedish registry of acute myocardial infarction, which provides high-quality information on all acute myocardial infarctions in the country since 1987. The…
clock | September 15, 2008Sleep researchers rarely pay attention to stuff like sleep position and sleep behavior, as opposed to EEG data, sleep duration, timing and patterns. But now Darren reviews that neglected aspect of animal sleep.
Also see my post on the same topic about the sleep behavior in whales.
clock | August 25, 2008Monday night - time to check out the new articles in PLoS Biology and PLoS Medicine:
Is Sleep Essential?:
Everybody knows that sleep is important, yet the function of sleep seems like the mythological phoenix: "Che vi sia ciascun lo dice, dove sia nessun lo sa" ("that there is one they all say, where it may be no one knows," Wolfgang Amadeus Mozart and Lorenzo da Ponte [1790], Così fan tutte). But what if the search for an essential function of sleep is misguided? What if sleep is not required but rather a kind of extreme indolence that animals indulge in when they have no more pressing…
edyong | August 9, 2008
Feeling exhausted after a long day is an all too familiar part of modern life. We drag ourselves into bed, hoping to shut down our minds for a night, waking up recharged the next day. But contrary to popular belief, your brain does anything but shut down during sleep.
Science is beginning to reveal that sleep is a crucial chance for the brain to consolidate the massive amount of sensory information it receives during the day. It acts as a time-out between periods of consciousness and gives the brain a chance to weave lasting memories from experiences.
For something that is so crucial…
clock | August 7, 2008...but if you do, I hope it was enjoyable! And edifying, of course. Kind of science that is amenable to experimentation at home.
clock | June 12, 2008Two of my SciBlings have recently covered papers that my readers should find interesting:
Joseph: Bright Light and Melatonin Treatment Improves Dementia:
A study published in JAMA indicates that treatment with bright light alone (1,000 lux), or bright light combined with melatonin, can improve symptoms in patients with dementia. Melatonin alone appeared to have a slight adverse effect.
Chris Chatham : Time Perception: In the Absence of "Time Sensation?":
In their newly in-press TICS article, Ivry and Schlerf review the state of the art in cognitive modeling of time perception - perhaps the…
clock | June 10, 2008Circadian Math: 1 Plus 1 Doesn't Always Equal 2:
Like a wristwatch that needs to be wound daily for accurate time-telling, the human circadian system -- the biological cycles that repeat approximately every 24 hours -- requires daily light exposure to the eye's retina to remain synchronized with the solar day. In a new study published in the June issue of Neuroscience Letters, researchers have demonstrated that when it comes to the circadian system, not all light exposure is created equal.
Morningness Is A Predictor Of Better Grades In College:
Morningness is a predictor of better grades in…
clock | May 22, 2008From November 01, 2005, a review of a review...
Here is a nice article in Washington Post - Ecological Niche May Dictate Sleep Habits - about the adaptive function of sleep.
It addresses some of the themes I am interested in.
First, the unfortunate fact is that sleep was initially defined by researchers of humans, i.e., medical researchers. Inevitably, the (electrophysiological) definition of sleep was thus saddled with unneccessary anthropocentric elements that for decades hampered the study of evolution of sleep.
I was present at the meeting (here in Biotechnology Center in RTP) several…
clock | May 20, 2008What it really means when we are talking about babies "sleeping through the night" (from September 22, 2005)
-----------------------------------------Trixe Update is a blog that is very unusual. First, just looking technically, the posts go from top to bottom instead of the latest post being on the very top. Second, the whole blog is devoted to the day-by-day growth and development of Trixie, from birth until about the age of two.
The graph on the right (and there are many different graphs there) shows the sleep-wake cycle. Unfortunately, the first four months - the most interesting months…
clock | May 19, 2008The fourth part of a four-part series on the topic, this one from April 02, 2006....
This being the National Sleep Awareness Week and on the heels of the recent study on sleep of adolescents, it is not surprising that this issue is all over the media, including blogs, these days.
I have written about it recently several times. I present some science and some opinion here and add a little more science and much more opinion here.
You can look at media coverage here and listen to an excellent podcast linked here. Some basic underlying science is covered here.
All of this targets highschoolers…