Rhythmic Human
clock | August 8, 2006Today's New York Times has a good article about jet-lag: The Science of Zzzzz's. I am glad to hear that JetBlue is using scientific advice in helping their pilots be fresh and alert, especially now that JetBlue has started flying from RDU.
clock | August 4, 2006Oversimplified, but much believed idea: Many cancer drugs target cells during cell division. Healthy cells divide at a particular time of day (exact timing may differ between cell types). Cancer cells are not under the control of the circadian clock so they divide at all times of the day (and they divide more often anyway). Thus, incorrect timing of chemotherapy - given during the time most healthy cells divide as well as some cancer cells - will kill more healthy than cancerous cells, leading to early termination of treatment and worse prognosis. Correct timing - during the time when…
clock | August 3, 2006A number of media outlets are reporting on the new Duke University study on the effects of time-of-day on the outcome of surgery:
Patients who undergo surgery late in the afternoon are more likely to experience unexpected adverse events related to their anesthesia than are patients whose operations begin in the morning, a new analysis by Duke University Medical Center researchers suggests.
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In addition to spotting problems related to anesthesia, Wright and her colleagues also found that surgery patients experienced a significant increase in "…
clock | July 17, 2006From Financial Times: 'Social jet lag' causes fatigue and illness (also on MSNBC):
Half the people in modern urban societies suffer from "social jet lag" because their body clocks are seriously out of step with their real lives, the Euroscience forum in Munich heard on Monday.
The result was chronic fatigue and an increased susceptibility to disease, researches found. They concluded that employers should tell staff to wake up in their own time and come in to work when they feel ready to.
Till Roenneberg, a circadian rhythm researcher at Ludwig Maximilians University in Munich, coined the…
clock | July 1, 2006
I did not find it surprising. If you have money, you can buy yourself time - to exercise, to eat a good meal at a nice restaurant or to fix healthy food at home, and to sleep as much as your body needs. As a result, you will be healthier overall. You can read about the study here (hat-tip:Sleepdoctor)
clock | June 29, 2006This week, it took me quite a while to figure out how to answer the Ask a ScienceBlogger question: "What are some unsung successes that have occurred as a result of using science to guide policy?"
As a relative newcomer to the United States, and even more a newcomer to American politics, I was not around long enough to pay attention to various science-driven policies of the past. Most of what I know are far from "unsung" successes - from Manhattan Project, through Clean Air and Clean Water acts, to the EWndangered Species Act, to the international Kyoto Protocol. Dealing with DDT, DES,…
clock | June 29, 2006The absence of light-dark cycles in space (e.g., on the shuttle or space station) results in disruptions of sleep. It has been proposed that humans who spend prolonged time in space are suffering from jet-lag - the internal desynchronization of clocks in various tissues.
A new experiment on the space station will take a somewhat different strategy than usual. Instead of measuring EEG (brain activity), it will monitor EKG (heart activity) over a period of 150 days.
The idea, brought by Irish researchers, is that EEG monitoring is not capable of measuring internal desynchronization of the…
clock | June 23, 2006Rozerem is a selective melatonin agonist. It acts on melatonin receptors at the suprachiasmatic nucleus. It is prescribed as a non-addictive sleep aid for people having difficulties with the onset of sleep, i.e., falling asleep in the evening.
While melatonin itself appears unlikely to be a molecule that directly induces sleep, it does have phase-resetting effects on the circadian clock. Thus, Rozerem appears ideal as an aid for extreme "owls" to help them fall asleep (if they need to wake up early in the morning, as some jobs require). By mimicking melatonin, it would phase-advance the…
clock | June 19, 2006
Melatonin is secreted in human mother's milk with a daily rhythm - high at night, undetectable during the day (see the figure under the fold):
It has been known for a long time that mother's melatonin entrains the circadian rhythms in the SCN (suprachiasmatic nucleus) of the embryos - thus they are born with a correct phase (time of day). However, a study in rats suggests that melatonin in mother's milk is unlikely to be able to entrain the pups circadian rhythms after they are born.
So, the appearance of melatonin in the milk of breastfeeding humans may either be:
a) just a by-product…
clock | June 16, 2006Interesting:
Melatonin may be found in grapes
MILAN, Italy, June 16 (UPI) -- Scientists in Italy say they have discovered that the grapes used in popular red wines may contain high levels of the sleep hormone melatonin.
Melatonin is naturally secreted by the pineal gland in the brain, especially at night, and it tells the body when it is time to sleep, according to researcher Iriti Marcello at the University of Milan.
Hey, hey, what do you say:
Until recently, melatonin was thought to be exclusively produced by mammals, but has recently been discovered in plants.
Excuse me, but we've known…
clock | June 12, 2006So, Wellbutrin is now officially a drug for treating Seasonal Affective Disorder. And chocolate is so unofficially. But, those may only take the edge off of the symptoms - they cannot affect the underlying causes.
clock | June 12, 2006
This post is perhaps not my best post, but is, by far, my most popular ever. Sick and tired of politics after the 2004 election I decided to start a science-only blog - Circadiana. After a couple of days of fiddling with the templae, on January 8, 2005, I posted the very first post, this one, at 2:53 AM and went to bed. When I woke up I was astonished as the Sitemeter was going wild! This post was linked by BoingBoing and later that day, by Andrew Sullivan. It has been linked by people ever since, as recently as a couple of days ago, although the post is a year and a half old.…