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In rhythm with the sun: The body’s biological clock
Night owl or early bird?
As with almost all life on Earth, human beings also function in cycles of light and dark. Look what happens to the human organism (and psyche) every day.
2am: Highest level of lymphocytes. The body heals well overnight.
3am: Blood flow through the brain is at its greatest at night.
4am: Growth hormone is secreted at night. It is responsible for tissue regeneration in adults and growth in children. The level of vasopressin is also raised, thanks to which we don't have to run to the bathroom for a pee. In children, where the endocrine system is still developing, bed-wetting is more likely. At night, the level of prolactin, the hormone responsible mainly for lactation, is at its highest.
5am: Body temperature is at its lowest. For night owls, the minimum temperature occurs during the middle of the sleep cycle. For early birds, this occurs at the end of their sleep.
5am–7am: Large intestine movement and body detox.
6am: Reveille! When light hits the retina, the hypothalamus reduces production of melatonin (the sleep hormone). Within 30 minutes of waking up, we observe a steady increase in our cortisol level, which reaches its maximum at about 7am. Cortisol accelerates gluconeogenesis (the production of glucose, mainly from amino acids) above all in the liver, but also in the kidneys and small intestine. It accelerates the breakdown of fatty acids (allowing them to be converted into energy), and inhibits the immune system. Cortisol increases the secretion of vasopressin and noradrenaline, which mobilizes the body to action. The effect of this is to increase the concentration of glucose in the blood, thanks to which we have the energy to start the day. During these hours, it is a good idea to move a bit, stretching our tendons and muscles, stiff from sleep. Cortisol also participates in the laying down of short-term memories (it is worth looking at your timetable in order to start the day better prepared). This is also a good time for meditation.
7am: Melatonin production stops. Its level falls. The body is now particularly sensitive to gentle stimuli.
7am–9am: Stomach activity. A high level of digestion and nutrient absorption. A good time for breakfast.
8am: Noradrenaline raises our body temperature. The highest concentration of cortisol (the stress hormone). A jump in the concentration of ghrelin, the hunger hormone; we eat breakfast.
9am: High concentration of glucose in the blood due to the high concentration of cortisol.
9am–11am: Spleen and kidney activity. Production of digestive enzymes. Work and exercise.
10am: An increase in body temperature increases vigour and alertness.
11am–1pm: Concentration and cognitive abilities at a high level.
2pm: The highest concentration of glucose in the blood. Glucose is the main fuel for muscles and the brain. Its concentration is directly correlated with physical and mental activity.
3pm: Noradrenaline and body temperature increase the coordination of movement and muscle activity.
3pm–6pm: The best results from intensive physical activity and the least vulnerability to injury. The mitochondria of the skeletal muscles exhibit their most active cell respiration. Increased oxygen uptake in the lungs. By the by, intensive muscle activity can reset a disturbed biological clock.
8pm: The pineal gland starts to produce melatonin. It is made from tryptophan. Pumpkin seeds and dried spirulina (seaweed) are excellent sources of this. It may be worth snacking on these during the day to have the raw materials for sweet dreams. The production of melatonin is inhibited by light, so during these hours we should avoid intensive screen time and the solarium.
9pm: The melatonin level rises. It can be detected in plasma and saliva.
10pm: Intestinal activity slows. It is not a good idea to stuff your face now, although food at this time of day tastes best.
11pm: Low cortisol level. It will rise while we sleep and, reaching a high level, will be the signal to wake up.
12am: High level of testosterone; it peaks after three hours of sleep. During the night the level of ghrelin, the hormone that signals hunger, rises. If we are sleeping lightly, we may feel hungry.
Nobel 2017: Proteins CLOCK and BMAL1 activate the transcription of the PER and CRY genes. The created PER and CRY proteins connect together and inhibit the work of the genes CLOCK and BMAL1. Over time, the PER and CRY proteins break down which allows CLOCK and BMAL1 to appear, again activating PER and CRY…
This sequence repeats and, in some sense, pulsates in a 24-hour cycle.
The most important influence on synchronizing the biological clock ('zeitgeber') is light. The suprachiasmatic nucleus is located in the hypothalamus, above the intersection of the optic nerves (hence its name). This is where the synchronization of the biological clock with the daily rhythm takes place. Other things that influence the clock are food intake and physical activity.
Blue light (emitted by the screens of electronic equipment), inhibits the production of melatonin much more so than orange light. This is why it is hard to fall asleep right after switching off your computer or putting down your smartphone.
In 1962, the caver Michel Siffre, as part of an experiment, shut himself in a cave for two months. It turned out that he ate, slept and woke up according to his internal clock (in a cycle lasting 24.5 hours). Interestingly, his perception of time changed. Every day he counted to 120 at the tempo of one number per second. After some time spent in the dark this exercise took him as long as five minutes.
Depending upon the time of day, plants not only open and close their flowers but they also raise and lower their branches.
It was once thought that bacteria are too primitive to count time. But it turns out that cyanobacteria also have an internal clock. Those that have an inactivated biological clock fare worse with the day/night cycle.
Mushrooms also have a biological clock, which evolved independently from that of bacteria and animals.
Animals fed at a time when they ought to be resting have a tendency to gain weight.
Depression, sleep disruption and metabolic disruption can be caused by impairment of the circadian rhythm (the 24-hour cycle).
The efficacy of medicines and their toxicity depends upon the time of day they are given.
The signals between two selected neurons always run at the same time and with high accuracy. This is how our internal stopwatch works.
The metaphor of Indra's diamond net, which originates from the Garland Sutra, postulates that everything that exists creates an endless net of diamonds, extending throughout the universe. Each point in this net is a jewel whose facets reflect all others, and each is also a universe containing its entire past, present and future. If a new element appears in one of the diamonds, even a speck of dust, the whole net will react to its presence. The human body resembles a net of common interactions and dependencies. An external or internal stimulus causes a whole range of physiological changes, whose effects spread and affect each other like waves on the surface of a lake. There's no way we can reduce such a complicated system to a binary description, but we can see in it some repetitive events and tendencies that seem to pulse in time with the repetition of sunrises and sunsets. The biological clock is a masterful achievement of evolution, and understanding how it works can play a significant role in setting the rhythm for a successful day.
Translated from the Polish by Annie Jaroszewicz
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How would the ability to genetically customize children change society? Sci-fi author Eugene Clark explores the future on our horizon in Volume I of the "Genetic Pressure" series.
- A new sci-fi book series called "Genetic Pressure" explores the scientific and moral implications of a world with a burgeoning designer baby industry.
- It's currently illegal to implant genetically edited human embryos in most nations, but designer babies may someday become widespread.
- While gene-editing technology could help humans eliminate genetic diseases, some in the scientific community fear it may also usher in a new era of eugenics.
Tribalism and discrimination<p>One question the "Genetic Pressure" series explores: What would tribalism and discrimination look like in a world with designer babies? As designer babies grow up, they could be noticeably different from other people, potentially being smarter, more attractive and healthier. This could breed resentment between the groups—as it does in the series.</p><p>"[Designer babies] slowly find that 'everyone else,' and even their own parents, becomes less and less tolerable," author Eugene Clark told Big Think. "Meanwhile, everyone else slowly feels threatened by the designer babies."</p><p>For example, one character in the series who was born a designer baby faces discrimination and harassment from "normal people"—they call her "soulless" and say she was "made in a factory," a "consumer product." </p><p>Would such divisions emerge in the real world? The answer may depend on who's able to afford designer baby services. If it's only the ultra-wealthy, then it's easy to imagine how being a designer baby could be seen by society as a kind of hyper-privilege, which designer babies would have to reckon with. </p><p>Even if people from all socioeconomic backgrounds can someday afford designer babies, people born designer babies may struggle with tough existential questions: Can they ever take full credit for things they achieve, or were they born with an unfair advantage? To what extent should they spend their lives helping the less fortunate? </p>
Sexuality dilemmas<p>Sexuality presents another set of thorny questions. If a designer baby industry someday allows people to optimize humans for attractiveness, designer babies could grow up to find themselves surrounded by ultra-attractive people. That may not sound like a big problem.</p><p>But consider that, if designer babies someday become the standard way to have children, there'd necessarily be a years-long gap in which only some people are having designer babies. Meanwhile, the rest of society would be having children the old-fashioned way. So, in terms of attractiveness, society could see increasingly apparent disparities in physical appearances between the two groups. "Normal people" could begin to seem increasingly ugly.</p><p>But ultra-attractive people who were born designer babies could face problems, too. One could be the loss of body image. </p><p>When designer babies grow up in the "Genetic Pressure" series, men look like all the other men, and women look like all the other women. This homogeneity of physical appearance occurs because parents of designer babies start following trends, all choosing similar traits for their children: tall, athletic build, olive skin, etc. </p><p>Sure, facial traits remain relatively unique, but everyone's more or less equally attractive. And this causes strange changes to sexual preferences.</p><p>"In a society of sexual equals, they start looking for other differentiators," he said, noting that violet-colored eyes become a rare trait that genetically engineered humans find especially attractive in the series.</p><p>But what about sexual relationships between genetically engineered humans and "normal" people? In the "Genetic Pressure" series, many "normal" people want to have kids with (or at least have sex with) genetically engineered humans. But a minority of engineered humans oppose breeding with "normal" people, and this leads to an ideology that considers engineered humans to be racially supreme. </p>
Regulating designer babies<p>On a policy level, there are many open questions about how governments might legislate a world with designer babies. But it's not totally new territory, considering the West's dark history of eugenics experiments.</p><p>In the 20th century, the U.S. conducted multiple eugenics programs, including immigration restrictions based on genetic inferiority and forced sterilizations. In 1927, for example, the Supreme Court ruled that forcibly sterilizing the mentally handicapped didn't violate the Constitution. Supreme Court Justice Oliver Wendall Holmes wrote, "… three generations of imbeciles are enough." </p><p>After the Holocaust, eugenics programs became increasingly taboo and regulated in the U.S. (though some states continued forced sterilizations <a href="https://www.uvm.edu/~lkaelber/eugenics/" target="_blank">into the 1970s</a>). In recent years, some policymakers and scientists have expressed concerns about how gene-editing technologies could reanimate the eugenics nightmares of the 20th century. </p><p>Currently, the U.S. doesn't explicitly ban human germline genetic editing on the federal level, but a combination of laws effectively render it <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">illegal to implant a genetically modified embryo</a>. Part of the reason is that scientists still aren't sure of the unintended consequences of new gene-editing technologies. </p><p>But there are also concerns that these technologies could usher in a new era of eugenics. After all, the function of a designer baby industry, like the one in the "Genetic Pressure" series, wouldn't necessarily be limited to eliminating genetic diseases; it could also work to increase the occurrence of "desirable" traits. </p><p>If the industry did that, it'd effectively signal that the <em>opposites of those traits are undesirable. </em>As the International Bioethics Committee <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">wrote</a>, this would "jeopardize the inherent and therefore equal dignity of all human beings and renew eugenics, disguised as the fulfillment of the wish for a better, improved life."</p><p><em>"Genetic Pressure Volume I: Baby Steps"</em><em> by Eugene Clark is <a href="http://bigth.ink/38VhJn3" target="_blank">available now.</a></em></p>
Meteorologists propose a stunning new explanation for the mysterious events in the Bermuda Triangle.
One of life's great mysteries, the Bermuda Triangle might have finally found an explanation. This strange region, that lies in the North Atlantic Ocean between Bermuda, Miami and San Juan, Puerto Rico, has been the presumed cause of dozens and dozens of mind-boggling disappearances of ships and planes.
A unique exoplanet without clouds or haze was found by astrophysicists from Harvard and Smithsonian.
- Astronomers from Harvard and Smithsonian find a very rare "hot Jupiter" exoplanet without clouds or haze.
- Such planets were formed differently from others and offer unique research opportunities.
- Only one other such exoplanet was found previously.
Munazza Alam – a graduate student at the Center for Astrophysics | Harvard & Smithsonian.
Credit: Jackie Faherty
Jupiter's Colorful Cloud Bands Studied by Spacecraft<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="8a72dfe5b407b584cf867852c36211dc"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/GzUzCesfVuw?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Scientists discover burrows of giant predator worms that lived on the seafloor 20 million years ago.
- Scientists in Taiwan find the lair of giant predator worms that inhabited the seafloor 20 million years ago.
- The worm is possibly related to the modern bobbit worm (Eunice aphroditois).
- The creatures can reach several meters in length and famously ambush their pray.
A three-dimensional model of the feeding behavior of Bobbit worms and the proposed formation of Pennichnus formosae.
Credit: Scientific Reports
Beware the Bobbit Worm!<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="1f9918e77851242c91382369581d3aac"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/_As1pHhyDHY?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
The idea behind the law was simple: make it more difficult for online sex traffickers to find victims.