Two studies done at the University of Minnesota Medical School and published in the early 1980’s measured the intensity, frequency, and durations of pelvic muscle contractions (measured with a pressure sensitive anal probe) of males and females during masturbation. There was basically no difference in the pattern of these contractions between males and females. […] A study done at Stanford University in 1994 found no significant gender differences in observed increases in heart rate, blood pressure, oxytocin, and anal contractions during orgasm.

{ Psychology Today | Continue reading }

The refractory period is the recovery phase after orgasm during which it is physiologically impossible for a man to have additional orgasms. This phase begins immediately after ejaculation. […] Although it is generally reported that women do not experience a refractory period and can thus experience an additional orgasm (or multiple orgasms) soon after the first one, some sources state that […] women may also experience a moment after orgasm in which further sexual stimulation does not produce excitement. […] clitoral hypersensitivity after orgasm can effectively create a refractory period. these women may be capable of further orgasms, but the pain involved in getting there makes the prospect undesirable. […]

the refractory period varies widely among individuals, ranging from minutes to days […] According to some studies, 18-year-old males have a refractory period of about 15 minutes, while those in their 70s take about 20 hours, with the average for all men being about half an hour. Although rarer, some males exhibit no refractory period or a refractory period lasting less than 10 seconds. […]

An increased infusion of the hormone oxytocin during ejaculation is believed to be chiefly responsible for the male refractory period, and the amount by which oxytocin is increased may affect the length of each refractory period. Another chemical which is considered to be responsible for the male refractory period is prolactin, which is repressed by dopamine, and is responsible for sexual arousal. […]

One alternative theory explains the male refractory period in terms of a peripheral autonomic feedback mechanism, rather than through central chemicals like oxytocin, serotonin, and prolactin. Autonomic feedback is already known to regulate other physiologic systems, such as breathing, blood pressure, and gut motility. This theory suggests that after male ejaculation, decreased wall tension in structures such as the seminal vesicles leads to a change in the fine autonomic signals sent from these organs, effectively creating a negative feedback loop. Such a mechanism is similar to decreased gastric and bowel motility once gastric contents have passed through. Once the feedback loop has been created, the refractory period remains until the loop is broken through restoration of the wall tension in the seminal vesicles. As men age, the time to restore tension in the seminal vesicles increases.

{ Wikipedia | Continue reading }

On planet K2-141b, hundreds of light-years away, oceans are made of molten lava, winds reach supersonic speeds and rain is made of rocks. Scientists have referred to the bizarre, hellish exoplanet as one of the most “extreme” ever discovered. 

Scientists have uncovered details of one of the newest “lava planets” — a world that so closely orbits its host star that much of it is composed of flowing lava oceans. […]

The Earth-sized exoplanet appears to have a surface, ocean and atmosphere all made of the same ingredients: rocks. […]

While analyzing the planet’s illumination pattern, scientists found that about two-thirds of the planet experiences perpetual daylight. K2-141b’s close proximity to its star gravitationally locks it in place — meaning the same side always faces the star.

This scorching hot part of the planet reaches temperatures of over 5,400 degrees Fahrenheit. It’s hot enough to not only melt rocks, but also vaporize them, creating a thin, inhospitable atmosphere.

The rest of the planet is cloaked in never-ending darkness, reaching frigid temperatures of negative 328 degrees Fahrenheit.

In Earth’s water cycle, water evaporates, rises up into the atmosphere, condenses, and returns to the surface as rain. Now imagine that process, but instead of water, K2-141b only has rocks to work with.

{ CBS | Continue reading }

screenprint { Bridget Riley, Composition with Circles 2 (Schubert 46), 2001 }

previously { Is Heaven hotter than Hell? }

John von Neumann (1903 – 1957) was a Hungarian-American mathematician, physicist, computer scientist, engineer and polymath. Von Neumann was generally regarded as the foremost mathematician of his time. He integrated pure and applied sciences.

Von Neumann made major contributions to many fields, including mathematics (foundations of mathematics, functional analysis, ergodic theory, representation theory, operator algebras, geometry, topology, and numerical analysis), physics (quantum mechanics, hydrodynamics, and quantum statistical mechanics), economics (game theory), computing (Von Neumann architecture, linear programming, self-replicating machines, stochastic computing), and statistics. […]

He first proposed a quantum logic in 1932 […] He founded the field of game theory as a mathematical discipline. […] His analysis of the structure of self-replication preceded the discovery of the structure of DNA. […] He made fundamental contributions to mathematical statistics and in the field of fluid dynamics. […] He was a founding figure in computing. […] Beginning in 1949, von Neumann’s design for a self-reproducing computer program is considered the world’s first computer virus, and he is considered to be the theoretical father of computer virology. […] Von Neumann and his appointed assistant on this project, Jule Gregory Charney, wrote the world’s first climate modelling software, and used it to perform the world’s first numerical weather forecasts. […] The first use of the concept of a singularity in the technological context is attributed to von Neumann. […]

Beginning in the late 1930s, von Neumann developed an expertise in explosions—phenomena that are difficult to model mathematically. During this period, von Neumann was the leading authority of the mathematics of shaped charges. This led to his involvement in the Manhattan Project. […] He made his principal contribution to the atomic bomb in the concept and design of the explosive lenses that were needed to compress the plutonium core of the Fat Man weapon that was later dropped on Nagasaki. […] As a Hungarian émigré, concerned that the Soviets would achieve nuclear superiority, he designed and promoted the policy of mutually assured destruction to limit the arms race. […]

Von Neumann was a child prodigy. When he was six years old, he could divide two eight-digit numbers in his head and could converse in Ancient Greek. When the six-year-old von Neumann caught his mother staring aimlessly, he asked her, “What are you calculating?” […]

Nobel Laureate Hans Bethe said “I have sometimes wondered whether a brain like von Neumann’s does not indicate a species superior to that of man”, and later Bethe wrote that “[von Neumann’s] brain indicated a new species, an evolution beyond man”. [… Israel Halperin said: “Keeping up with him was … impossible. The feeling was you were on a tricycle chasing a racing car.” […]

Von Neumann was also noted for his eidetic memory (sometimes called photographic memory). […] “He was able on once reading a book or article to quote it back verbatim; moreover, he could do it years later without hesitation. He could also translate it at no diminution in speed from its original language into English.”

{ Wikipedia | Continue reading }

oil on canvas { Gustave Caillebotte, Un balcon, boulevard Haussmann, 1888 }

Can lab-grown brains become conscious?

These tiny structures, known as brain organoids, are grown from human stem cells and have become a familiar fixture in many labs that study the properties of the brain. Muotri, a neuroscientist at the University of California, San Diego (UCSD), has found some unusual ways to deploy his. He has connected organoids to walking robots, modified their genomes with Neanderthal genes, launched them into orbit aboard the International Space Station, and used them as models to develop more human-like artificial-intelligence systems. Like many scientists, Muotri has temporarily pivoted to studying COVID-19, using brain organoids to test how drugs perform against the SARS-CoV-2 coronavirus.

But one experiment has drawn more scrutiny than the others. In August 2019, Muotri’s group published a paper in Cell Stem Cell reporting the creation of human brain organoids that produced coordinated waves of activity, resembling those seen in premature babies1. The waves continued for months before the team shut the experiment down. […]

The concerns over lab-grown brains have also highlighted a blind spot: neuroscientists have no agreed way to define and measure consciousness. Without a working definition, ethicists worry that it will be impossible to stop an experiment before it crosses a line.

{ Nature | Continue reading }

What if a pill can change your politics or religious reliefs? […] Psychotherapy assisted by psilocybin, the psychedelic compound in “magic mushrooms,” seems to be remarkably effective in treating a wide range of psychopathologies, but also causes a raft of unusual nonclinical changes not seen elsewhere in medicine. […]

Although its precise therapeutic mechanisms remain unclear, clinically relevant doses of psilocybin can induce powerful mystical experiences more commonly associated with extended periods of fasting, prayer or meditation. Arguably, then, it is unsurprising that it can generate long-lasting changes in patients: studies report increased prosociality and aesthetic appreciation, plus robust shifts in personality, values and attitudes to life, even leading some atheists to find God. What’s more, these experiences appear to be a feature, rather than a bug, of psilocybin-assisted psychotherapy, with the intensity of the mystical experience correlating with the extent of clinical benefit.

{ Scientific American | Continue reading }

An earlier universe existed before the Big Bang and can still be observed today, Sir Roger Penrose has said, as he received the Nobel Prize for Physics. […]

“The Big Bang was not the beginning. There was something before the Big Bang and that something is what we will have in our future.

“We have a universe that expands and expands, and all mass decays away, and in this crazy theory of mine, that remote future becomes the Big Bang of another aeon. 

“So our Big Bang began with something which was the remote future of a previous aeon and there would have been similar black holes evaporating away, via Hawking evaporation, and they would produce these points in the sky, that I call Hawking Points.

“We are seeing them. These points are about eight times the diameter of the Moon and are slightly warmed up regions. There is pretty good evidence for at least six of these points.”

{ The Telegraph | Continue reading }

Nobel Prize in Chemistry awarded to American biochemist Jennifer A. Doudna (left) and French microbiologist Emmanuelle Charpentier who discovered gene-editing tool CRISPR […] Doudna and Charpentier have been considered top candidates for the prize for several years, but there’s an ongoing fight over patents for CRISPR and its use.

{ Axios | Continue reading }

Faces provide not only cues to an individual’s identity, age, gender, and ethnicity but also insight into their mental states. The aim was to investigate the temporal aspects of processing of facial expressions of complex mental states for very short presentation times ranging from 12.5 to 100 ms. […]

Results show that participants are able to recognise very subtle differences between facial expressions; performance is better than chance, even for the shortest presentation time. Importantly, we show for the first time that observers can recognise these expressions based on information contained in the eye region only.

{ i-Perception | Continue reading }

We showcase an optical phenomenon that we call Third-Eye Rivalry. The effect is most easily induced by viewing one’s own reflection in a mirror. Using the pupil of the opposing eye as a fixation target, people can easily cross their eyes in free fusion to experience vivid rivalry. The resulting percept is of a prominent central “third” eye and two peripheral faces rivaling for perceptual dominance.

{ i-Perception | Continue reading }

Recently, some scientists from NASA have claimed that there may be a black hole like structure at the centre of the earth. We show that the existence of life on the earth may be a reason that this black hole like object is a black brane that has been formed from biological materials like DNA. Size of this DNA black brane is 109 times longer than the size of the earth’s core and compacted interior it. By compacting this long object, a curved space-time emerges, and some properties of black holes emerge. This structure is the main cause of the emergence of the large temperature of the core, magnetic field around the earth and gravitational field for moving around the sun. Also, this structure produces some waves which act like topoisomerase in biology and read the information on DNAs. […]

These dark DNAs not only exchange information with DNAs but also are connected with some of the molecules of water and helps them to store information and have memory. Thus, the earth is the biggest system of telecommunication which connects DNAs, dark DNAs and molecules of water.

{ Macedonian Journal of Medical Sciences | Continue reading }

photo ( Nadia Von Scotti }

Earlier this week, Elon Musk said there’s a “good chance” settlers in the first Mars missions will die. […] the trip itself will take a year based on current estimates, and applicants to settlement programs are told to expect this trip to be one way.

{ Popular Mechanics | Continue reading }

Moringa oleifera, an edible tree found worldwide in the dry tropics, is increasingly being used for nutritional supplementation. Its nutrient-dense leaves are high in protein quality, leading to its widespread use by doctors, healers, nutritionists and community leaders, to treat under-nutrition and a variety of illnesses. Despite the fact that no rigorous clinical trial has tested its efficacy for treating under-nutrition, the adoption of M. oleifera continues to increase. The “Diffusion of innovations theory” describes well the evidence for growth and adoption of dietary M. oleifera leaves, and it highlights the need for a scientific consensus on the nutritional benefits. […]

The regions most burdened by under-nutrition, (in Africa, Asia, Latin America, and the Caribbean) all share the ability to grow and utilize an edible plant, Moringa oleifera, commonly referred to as “The Miracle Tree.” For hundreds of years, traditional healers have prescribed different parts of M. oleifera for treatment of skin diseases, respiratory illnesses, ear and dental infections, hypertension, diabetes, cancer treatment, water purification, and have promoted its use as a nutrient dense food source. The leaves of M. oleifera have been reported to be a valuable source of both macro- and micronutrients and is now found growing within tropical and subtropical regions worldwide, congruent with the geographies where its nutritional benefits are most needed.

Anecdotal evidence of benefits from M. oleifera has fueled a recent increase in adoption of and attention to its many healing benefits, specifically the high nutrient composition of the plants leaves and seeds. Trees for Life, an NGO based in the United States has promoted the nutritional benefits of Moringa around the world, and their nutritional comparison has been widely copied and is now taken on faith by many: “Gram for gram fresh leaves of M. oleifera have 4 times the vitamin A of carrots, 7 times the vitamin C of oranges, 4 times the calcium of milk, 3 times the potassium of bananas, ¾ the iron of spinach, and 2 times the protein of yogurt” (Trees for Life, 2005).

Feeding animals M. oleifera leaves results in both weight gain and improved nutritional status. However, scientifically robust trials testing its efficacy for undernourished human beings have not yet been reported. If the wealth of anecdotal evidence (not cited herein) can be supported by robust clinical evidence, countries with a high prevalence of under-nutrition might have at their fingertips, a sustainable solution to some of their nutritional challenges. […]

The “Diffusion of Innovations” theory explains the recent increase in M. oleifera adoption by various international organizations and certain constituencies within undernourished populations, in the same manner as it has been so useful in explaining the adoption of many of the innovative agricultural practices in the 1940-1960s. […] A sigmoidal curve (Figure 1), illustrates the adoption process starting with innovators (traditional healers in the case of M. oleifera), who communicate and influence early adopters, (international organizations), who then broadcast over time new information on M. oleifera adoption, in the wake of which adoption rate steadily increases.

{ Ecology of Food and Nutrition | Continue reading }

Books are horrible at teaching. So are lectures. So are documentaries. If to teach means to impart lasting knowledge, then our current educational media are lousy teachers. We encounter thousands of concepts a year, yet the vast majority fades from our memory into the ether, never to be held again. We forget. […]

We also forget information at an exponentially decaying rate; more than half of what we process is gone within the first 20 minutes. This means that we need several prompts to make persistent memories. (For more on memory failure modes, see Schachter’s Seven Sins of Memory.). […]

What are some dimensions to consider if we want machines to augment our ability to remember?

{ Machines + Society | Continue reading }

Self-promotion is common in everyday life. Yet, across 8 studies (N = 1,687) examining a broad range of personal and professional successes, we find that individuals often hide their successes from others and that such hiding has relational costs. […]

Whereas previous research highlights the negative consequences of sharing one’s accomplishments with others, we find that sharing is superior to hiding for maintaining one’s relationships.

{ Journal of Personality and Social Psychology | Continue reading }

signs of dishonesty decreased trust but only in those who had not previously built a good reputation as honest partners.

On the contrary, those who could establish a good reputation were trusted even when they were no longer trustworthy, suggesting that participants could not successfully track changes in trustworthiness of those with an established good reputation.

{ Journal of Experimental Psychology | Continue reading }

lithograph { Ellsworth Kelly, Blue Curve, 2013 }

Use each of the numbers 1, 3, 4, and 6 exactly once with any of the four basic math operations (addition, subtraction, multiplication, and division) to total 24. Each number must be used once and only once, and you may define the order of operations; for example, 3 * (4 + 6) + 1 = 31 is valid, however incorrect, since it doesn’t total 24.

{ solution | Hacking, The art of Exploitation | PDF }

Amid all the fighting in your airways, messenger cells grab small fragments of virus and carry these to the lymph nodes, where highly specialized white blood cells—T-cells—are waiting. The T-cells are selective and preprogrammed defenders. Each is built a little differently, and comes ready-made to attack just a few of the zillion pathogens that could possibly exist. For any new virus, you probably have a T-cell somewhere that could theoretically fight it. Your body just has to find and mobilize that cell. Picture the lymph nodes as bars full of grizzled T-cell mercenaries, each of which has just one type of target they’re prepared to fight. The messenger cell bursts in with a grainy photo, showing it to each mercenary in turn, asking: Is this your guy? When a match is found, the relevant merc arms up and clones itself into an entire battalion, which marches off to the airways.

Some T-cells are killers, which blow up the infected respiratory cells in which viruses are hiding. Others are helpers, which boost the rest of the immune system. Among their beneficiaries, these helper T-cells activate the B-cells that produce antibodies—small molecules that can neutralize viruses by gumming up the structures they use to latch on to their hosts. Roughly speaking—and this will be important later—antibodies mop up the viruses that are floating around outside our cells, while T-cells kill the ones that have already worked their way inside. T-cells do demolition; antibodies do cleanup.

Both T-cells and antibodies are part of the adaptive immune system. This branch is more precise than the innate branch, but much slower: Finding and activating the right cells can take several days. It’s also long-lasting: Unlike the innate branch of the immune system, the adaptive one has memory.

After the virus is cleared, most of the mobilized T-cell and B-cell forces stand down and die off. But a small fraction remain on retainer—veterans of the COVID-19 war of 2020, bunkered within your organs and patrolling your bloodstream. This is the third and final phase of the immune response: Keep a few of the specialists on tap. If the same virus attacks again, these “memory cells” can spring into action and launch the adaptive branch of the immune system without the usual days-long delay. […]

Many infected people still clear the virus after a few weeks of nasty symptoms. But others don’t. Maybe they initially inhaled a large dose of virus. Maybe their innate immune systems were already weakened through old age or chronic disease. In some cases, the adaptive immune system also underperforms: T-cells mobilize, but their levels recede before the virus is vanquished, “almost causing an immunosuppressed state,” Iwasaki says. […]

There are also preliminary hints that some people might have a degree of preexisting immunity against the new coronavirus. Four independent groups of scientists—based in the U.S., Germany, the Netherlands, and Singapore—have now found that 20 to 50 percent of people who were never exposed to SARS-CoV-2 nonetheless have significant numbers of T-cells that can recognize it. These “cross-reactive” cells likely emerged when their owners were infected by other, related coronaviruses, including the four mild ones that cause a third of common colds, and the many that infect other animals.

But Farber cautions that having these cross-reactive T-cells “tells you absolutely nothing about protection.” It’s intuitive to think they would be protective, but immunology is where intuition goes to die. The T-cells might do nothing. There’s an outside chance that they could predispose people to more severe disease. We can’t know for sure without recruiting lots of volunteers, checking their T-cell levels, and following them over a long period of time to see who gets infected—and how badly.

Even if the cross-reactive cells are beneficial, remember that T-cells act by blowing up infected cells. As such, they’re unlikely to stop people from getting infected in the first place, but might reduce the severity of those infections.

{ The Atlantic | Continue reading }

{ sunglasses-like VR hardware }

…a girl with different-colored eyes and ambiguous genitals who appeared at a Seattle genetics clinic. Her ovaries proved to have only XX chromosomes—typical female—but her other tissues were mixtures of XX and XY. Further analysis showed that she had started out as opposite-sex twins. But early in development, the two embryos had fused, becoming a single, highly unusual child. Like a verse from the old Ray Stevens novelty song “I’m My Own Grandpa,” this girl was her own twin brother.

In pregnant women, fetal stem cells can cross the placenta to enter the mother’s bloodstream, where they may persist for years. If Mom gets pregnant again, the stem cells of her firstborn, still circulating in her blood, can cross the placenta in the other direction, commingling with those of the younger sibling. Heredity can thus flow “upstream,” from child to parent—and then over and down to future siblings.

Forget the notion that your genome is just the DNA in your chromosomes. We have another genome, small but vital, in our cells’ mitochondria—the tiny powerhouses that supply energy to the cell. Though the mitochondrial genes are few, damage to them can lead to disorders of the brain, muscles, internal organs, sensory systems, and more. At fertilization, an embryo receives both chromosomes and mitochondria from the egg, and only chromosomes from the sperm. Mitochondrial heredity thus flows strictly through the maternal line; every boy is an evolutionary dead end, as far as mitochondria are concerned.

{ The Atlantic | Continue reading }

For the second time ever, astronomers have detected a pattern in a mysterious fast radio burst coming from space. […] earlier this year when astronomers found that FRB 180916.J0158+65 had a pattern in bursts occurring every 16.35 days. Over the course of four days, the signal would release a burst or two each hour. Then, it would go silent for another 12 days.

Now, they have detected a pattern in a second repeating fast radio burst, known as FRB 121102. During this cyclical pattern, radio bursts are emitted during a 90-day window, followed by a silent period of 67 days. This pattern repeats every 157 days.

{ CNN | Continue reading }