Circadian rhythm

A circadian rhythm /sɜːrˈkdiən/ is any biological process that displays an endogenous, entrainable oscillation of about 24 hours. These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in plants, animals, fungi, and cyanobacteria.

The term circadian comes from the Latin circa, meaning "around" (or "approximately"), and diēm, meaning "day". The formal study of biological temporal rhythms, such as daily, tidal, weekly, seasonal, and annual rhythms, is called chronobiology.

Although circadian rhythms are endogenous ("built-in", self-sustained), they are adjusted (entrained) to the local environment by external cues called zeitgebers (from German, "time giver"), which include light, temperature and redox cycles.

History

The earliest recorded account of a circadian process dates from the 4th century B.C.E., when Androsthenes, a ship captain serving under Alexander the Great, described diurnal leaf movements of the tamarind tree. The observation of a circadian or diurnal process in humans is mentioned in Chinese medical texts dated to around the 13th century, including the Noon and Midnight Manual and the Mnemonic Rhyme to Aid in the Selection of Acu-points According to the Diurnal Cycle, the Day of the Month and the Season of the Year.

Circadian Rhythm (film)

Circadian Rhythm is a 2005 action film that portrays a young woman's journey to discover who she is and why multiple enemies want her dead. The woman, Sarah Caul, played by Rachel Miner, is thrown into an artificial ‘construct’ where she must put the pieces of her life together and confront the menace that follows her every move.

Plot

Sarah L. Caul is 24 years old, attractive, skilled in martial arts, and highly intelligent. When the audience first meets her, she has no idea who she is, where she is from, or how she came to be in a white room, in no discernible location.

A familiar melody wakes Sarah from a deep sleep, and she finds herself teaching a history class in the school she attended at age 11. The ‘school’ is revealed to be a replica, and all of Sarah's books and files are completely blank and empty. Now thoroughly confused, Sarah's assistant principal, Sandrine (Terasa Livingstone), explains that Sarah is not a school teacher; rather, she is an assassin, and she has something on her body that Sandrine’s government desires. After a deadly shootout and a high speed chase on a cat-walk, Sarah is intercepted by another "handler" like Sandrine, who tells her the same story, claiming to be from a different country and a different agency, but still desiring the same unknown element. Like Sandrine, once the handler had extracted all of the evidence he could from Sarah, he attempts to kill her. Not able to trust anyone, Sarah spends the duration of her time in the construct trying to stay alive long enough to uncover the truth, and find out why so many people want her dead. She endures a series of wire-fu fights and a car chase while conducting an intense investigation into her past.

Podcasts:

PLAYLIST TIME:

Circadian Rhythm

by: Son Volt

[Incomprehensible]
Pretty fingers on the phone
Non violent grace, this religion
No one wants to be alone
Reclaim the rust that northern birds take
It like a song that in their feet
[Incomprehensible] on the radio
Take a little time on Cherokees tree
Chaos and precision with a smile
Sipping summer in the shade
Thoughts for the plane with brown eyes waiting
Guitar, careless whirlwind, belief gets made
Carrying on so far under the cross
Manifestos to keep us sane
The time is so weary of conflict
Silent answers, silent name
I can't stand anymore decisions




Latest News for: circadian rhythm

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Can a daily nap do more harm than good? A expert explains

Alternet 22 Mar 2025
This isn’t just due to a heavy lunch – our internal body clock, or circadian rhythm, creates cycles of wakefulness and tiredness throughout the day. The early afternoon lull is part of this rhythm, which is why so many people feel drowsy at that time.
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Seasonal triggers for allergies

Deccan Herald 22 Mar 2025
... clothes after outdoor activities can also help avoid an accumulation of pollen and pollutants on the skin and mucous membranes.</p>.<p> Seasonal variations may disturb circadian rhythms.
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UAE: How new parents can manage bedtime routines, overcome sleepless nights

Khaleejtimes 22 Mar 2025
Stay up to date with the latest news ... Ronika Sagar, a new mother, said that she has been following the exact same routine since day one of her baby being born, which she said, “helped get his circadian rhythm of day and night accurately.” ... .
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Can a swath of new luxury hotels disrupt Palm Beach’s buzzy social scene?

New York Post 22 Mar 2025
They covered their faces with oxygen masks and breathed — for a full hour ... 5 ... Amrit Ocean Resort ... 5 ... It has also updated its spa, modeled on the Alhambra palace, with such new offerings as a circadian rhythm treatment aimed at opening energy pathways. 5.
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They tried to build the healthiest home in America

Business Insider 22 Mar 2025
Cassidy Araiza for BI ... Cassidy Araiza for BI ... Cassidy Araiza for BI ... It has 16-foot sliding doors and 15- to 20-foot floor-to-ceiling windows, which Brian said were designed to let in natural light that aligns with the family's "circadian rhythms." ... ....
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Are you waking up at 2 AM regularly? Health expert reveals hidden triggers

The Times of India 21 Mar 2025
But with some, this natural circadian rhythm gets disturbed such that cortisol is raised during the nighttime and keeps them awake when they ought to sleep soundly.Causes of sleep disruptionThe two major culprits are the causatives of this imbalance.
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I Tried Stephen Fry's Unusual Sleeping Hack – Here's How It Went

Huffington Post 21 Mar 2025
I go out to catch the morning rays every day to help keep my circadian rhythm in check, and I stop eating at least three hours before bed.
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A ‘middle-aged rave’ that ends before midnight? I’ll get my dancing shoes

The Irish Times 21 Mar 2025
And I don’t even have children ... She wanted to provide the experience of going clubbing but at a time that suits people who have to get up at 6am with the kids or risk throwing off their circadian rhythm for months if they don’t get to bed until dawn ... .
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PureEdge Pure Smart TruColor A19 Smart Bulb review: Nope

PC World 21 Mar 2025
However, an adjustable circadian rhythm mode that slowly shifts white temperature from its coolest setting to its warmest worked nicely, smoothly shifting the tone of the lighting over the course of the day.
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Sleepy Seniors Might Be At Increased Risk For Dementia

Knoxville Daily Sun 21 Mar 2025
Key Takeaways. Daytime drowsiness could be a warning sign for dementia among older individuals ... “We observed that sleeping, napping and circadian rhythms can change dramatically over only five years for women in their 80s,” Leng said ... More information.
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Dubai: How Midnight shopping; 2am deliveries are elevating Ramadan 2025 luxury retail

Khaleejtimes 21 Mar 2025
‬I like to think they have‭, ‬though‭. &nbsp; ‬ ... ‬At night‭, ‬without the time constraints of daily tasks or deadlines to meet‭, ‬the shopping scroll can stretch till sunrise‭, ‬creating a circadian retail rhythm all its own‭ ... ‬ ... .
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Can a daily nap do more harm than good?

RTE 21 Mar 2025
This isn't just due to a heavy lunch – our internal body clock, or circadian rhythm, creates cycles of wakefulness and tiredness throughout the day. The early afternoon lull is part of this rhythm, which is why so many people feel drowsy at that time.
Edit

Daytime sleepiness doubles dementia risk in older women: study

Knoxville Daily Sun 20 Mar 2025
The participants wore wrist devices to track their sleep and circadian rhythm patterns for three days at the start and end of the study ... and quality, daytime napping and circadian rhythm patterns.
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Clock change UK: When do the clocks go forward in March 2025, and how does ...

The Scotsman 20 Mar 2025
Research suggests that a change to our circadian rhythms explains why we like more upbeat songs ....
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Eight ways the sun makes us feel happier

AOL 20 Mar 2025
"This is to do with how it affects our brain chemistry, hormone regulation, and circadian rhythms.". Here is the science behind why the sun's rays are so good for us. .
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