Zombie fly fungus lures healthy male flies to mate with female corpses

Thursday, August 25th, 2022

Entomophthora muscae is a widespread, pathogenic fungus that survives by infecting common houseflies with its deadly spores — and that’s when things really start to swing:

After having infected a female fly with its spores, the fungus spreads until its host has slowly been consumed alive from within. After roughly six days, the fungus takes over the behavior of the female fly and forces it to the highest point, whether upon vegetation or a wall, where the fly then dies. When the fungus has killed the zombie female, it begins to release chemical signals known as sesquiterpenes.

“The chemical signals act as pheromones that bewitch male flies and cause an incredible urge for them to mate with lifeless female carcasses,” explains Henrik H. De Fine Licht, an associate professor at the University of Copenhagen’s Department of Environment and Plant Sciences and one of the study’s authors.

As male flies copulate with dead females, the fungal spores are showered onto the males, who then suffer the same gruesome fate.

Long-term low-dose alcohol intake promotes white adipose tissue browning and reduces obesity

Tuesday, August 23rd, 2022

There are numerous pieces of evidence indicating that moderate alcohol intake has a protective effect on metabolic diseases:

Our previous studies revealed that long-term low-dose alcohol intake resists high-fat diet (HFD) induced obesity. A process in which white adipose tissue can be stimulated and turned into heat-producing brown adipose tissue named white adipose browning is associated with energy expenditure and weight loss. In this study we aimed to investigate whether alcohol causes the browning of white adipose tissue and whether the browning of white adipose tissue is involved in the resistance to the occurrence of obesity caused by long-term low-dose alcohol intake. After eight months of alcohol feeding, the body weight of mice had no significant change, but the fat content and lipid deposition in the liver were reduced. Morphological observations revealed that the browning of white adipose tissue occurred.

[...]

Moderate alcohol drinking mice had faster lipid metabolism and slower lipid anabolism. In addition, we found that long-term low-dose alcohol intake prevented the increase of body weight, triglycerides, inflammation and energy expenditure decrease induced by HFD. Moderate alcohol consumption increased the expression of UCP1 and glucose uptake in the adipose tissue of the HFD group. In conclusion, our results show for the first time that alcohol can trigger the browning of white adipose tissue to counteract obesity.

It is descended from bipedal dinosaurs

Sunday, August 21st, 2022

Ostriches, unlike humans, can run very fast on two legs:

Their legs are all bone and tendon. They don’t have any muscles in their legs or feet. All the muscles are up in the body. It allows their legs to go faster — ostriches can run 45 miles an hour.

A human foot has 26 individual bones in it. And you have two feet, so you have 52 foot bones. That means a quarter of your skeleton is made of foot bones. Tons and tons of foot bones.

[...]

We are primates, and primates live in trees. And in trees, you need a mobile foot. Think about an orangutan’s foot, a chimpanzee’s foot. They can use their foot in the same way that I use my hand to grab onto things.

The bones that we have in our foot are the exact same 26 bones that a chimpanzee has. They’re just tweaked a little bit, and that converts our foot from a grasping organ, like a chimpanzee’s, into one that can push off the ground. But we still have those 26 individual bones. And what are the results? Well, you get plantar fasciitis, you get an ankle sprain.

[...]

Think about the ostrich lineage. It doesn’t come from an ape or a primate. It is descended from bipedal dinosaurs. The bones of their ancestors’ feet have fused together into a single, rigid column. They only have eight bones in their feet, so there’s less capacity for motion. Instead, their foot looks a lot like the Paralympic prosthetic blade that athletes use with that single rigid structure that can hit the ground, store elastic energy and then push off the ground and propel them into their next step.

Cubic boron arsenide may be best semiconductor of them all

Wednesday, August 17th, 2022

Silicon is one of the most abundant elements on Earth, but its properties as a semiconductor are far from ideal:

For one thing, although silicon lets electrons whizz through its structure easily, it is much less accommodating to “holes” — electrons’ positively charged counterparts — and harnessing both is important for some kinds of chips. What’s more, silicon is not very good at conducting heat, which is why overheating issues and expensive cooling systems are common in computers.

Now, a team of researchers at MIT, the University of Houston, and other institutions has carried out experiments showing that a material known as cubic boron arsenide overcomes both of these limitations. It provides high mobility to both electrons and holes, and has excellent thermal conductivity. It is, the researchers say, the best semiconductor material ever found, and maybe the best possible one.

So far, cubic boron arsenide has only been made and tested in small, lab-scale batches that are not uniform. The researchers had to use special methods originally developed by former MIT postdoc Bai Song to test small regions within the material. More work will be needed to determine whether cubic boron arsenide can be made in a practical, economical form, much less replace the ubiquitous silicon.

[...]

Not only is the material’s thermal conductivity the best of any semiconductor, the researchers say, it has the third-best thermal conductivity of any material — next to diamond and isotopically enriched cubic boron nitride.

Sauna bathing demonstrated a substantially supplementary effect on CRF, systolic BP, and total cholesterol levels

Monday, August 15th, 2022

Regular exercise and sauna bathing have each been shown to improve cardiovascular function in clinical populations:

However, experimental data on the cardiovascular adaptations to regular exercise in conjunction with sauna bathing in the general population is lacking. Therefore, we compared the effects of exercise and sauna bathing, to regular exercise using a multi-arm randomized controlled trial. Participants(n = 47) aged 49 ± 9 years with low physical activity levels, and at least one traditional CVD risk factor were randomly assigned (1:1:1) to guideline-based regular exercise and 15-minute post-exercise sauna (EXS), guideline-based regular exercise (EXE), or control (CON), for eight weeks. The primary outcomes were blood pressure (BP) and cardiorespiratory fitness (CRF). Secondary outcomes included fat mass, total cholesterol levels, and arterial stiffness. EXE had a greater change in CRF (+6.2 ml/kg/min; 95% CI, +4.2. to +8.3 ml/kg/min) and fat mass, but no differences in BP when compared to CON. EXS displayed greater change in CRF (+2.7 ml/kg/min; 95% CI, +0.2. to +5.3 ml/kg/min), lower systolic BP (-8.0 mmHg; 95% CI, -14.6 to -1.4 mmHg) and lower total cholesterol levels compared to EXE. Regular exercise improved CRF and body composition in sedentary adults with CVD risk factors. However, when combined with exercise, sauna bathing demonstrated a substantially supplementary effect on CRF, systolic BP, and total cholesterol levels. Sauna bathing is a valuable lifestyle tool that complements exercise for improving CRF, and decreasing systolic BP. Future research should focus on the duration, and frequency of exposure to ascertain the dose-response relationship.

Why that new “science-backed” supplement probably doesn’t work

Sunday, August 14th, 2022

In much the same way that everything in your fridge both causes and prevents cancer, Alex Hutchinson notes, there’s a study out there somewhere proving that everything boosts endurance:

A new preprint (a journal article that hasn’t yet been peer-reviewed, ironically) from researchers at Queensland University of Technology in Australia explores why this seems to be the case, and what can be done about it. David Borg and his colleagues comb through thousands of articles from 18 journals that focus on sport and exercise medicine, and unearth telltale patterns about what gets published—and perhaps more importantly, what doesn’t. To make sense of the studies you see and decide whether the latest hot performance aid is worth experimenting with, you also have to consider the studies you don’t see.

[...]

One way to illustrate these results is to plot something called the z-value, which is a statistical measure of the strength of an effect. In theory, if you plot the z-values of thousands of studies, you’d expect to see a perfect bell curve. Most of the results would be clustered around zero, and progressively fewer would have either very strongly positive or very strongly negative effects. Any z-value less than -1.96 or greater than +1.96 corresponds to a statistically significant result with p less than 0.05. A z-value between -1.96 and +1.96 indicates a null result with no statistically significant finding.

In practice, the bell curve won’t be perfect, but you’d still expect a fairly smooth curve. Instead, this is what you see if you plot the z-values from the 1,599 studies analyzed by Borg:

Borg Distribution of Z Values

There’s a giant missing piece in the middle of the bell curve, where all the studies with non-significant results should be. There are probably lots of different reasons for this, both driven by decisions that researchers make and—just as importantly—decisions that journals make about what to publish and what to reject. It’s not an easy problem to solve, because no journal wants to publish (and no reader wants to read) thousands of studies that conclude, over and over, “We’re not yet sure whether this works.”

Turmeric is routinely adulterated with a yellow pigment that contains lead

Saturday, August 13th, 2022

Rural Bangladesh has a lead-poisoning problem — because turmeric is routinely adulterated with a yellow pigment that contains lead, PbCrO4. Wow.

Resistant starch reduced upper gastrointestinal cancers by more than half

Friday, August 12th, 2022

An international trial with almost 1,000 patients with Lynch syndrome revealed that a regular dose of resistant starch, also known as fermentable fibre, taken for an average of two years, did not affect cancers in the bowel but did reduce cancers in other parts of the body by more than half:

This effect was particularly pronounced for upper gastrointestinal cancers including oesophageal, gastric, biliary tract, pancreatic and duodenum cancers.

The astonishing effect was seen to last for 10 years after stopping taking the supplement.

The study, led by experts at the Universities of Newcastle and Leeds, published today in Cancer Prevention Research, a journal of the American Association for Cancer Research, is a planned double blind 10 year follow–up, supplemented with comprehensive national cancer registry data for up to 20 years in 369 of the participants.

Previous research published as part of the same trial, revealed that aspirin reduced cancer of the large bowel by 50%.

“We found that resistant starch reduces a range of cancers by over 60%. The effect was most obvious in the upper part of the gut,” explained Professor John Mathers, professor of Human Nutrition at Newcastle University. “This is important as cancers of the upper GI tract are difficult to diagnose and often are not caught early on.

“Resistant starch can be taken as a powder supplement and is found naturally in peas, beans, oats and other starchy foods. The dose used in the trial is equivalent to eating a daily banana; before they become too ripe and soft, the starch in bananas resists breakdown and reaches the bowel where it can change the type of bacteria that live there.

“Resistant starch is a type of carbohydrate that isn’t digested in your small intestine, instead it ferments in your large intestine, feeding beneficial gut bacteria — it acts in effect, like dietary fibre in your digestive system. This type of starch has several health benefits and fewer calories than regular starch. We think that resistant starch may reduce cancer development by changing the bacterial metabolism of bile acids and to reduce those types of bile acids that can damage our DNA and eventually cause cancer. However, this needs further research.”

The Amish have been breeding themselves for plainness

Thursday, August 4th, 2022

The Amish population doubles every 20 years:

The North American Amish population grew by an estimated 195,710 since 2000, increasing from approximately 177,910 in 2000 to 373,620 in 2022, an increase of 110 percent. The Amish population doubles about every 20 years.

[…]

The primary forces driving the growth are sizable nuclear families (five or more children on average) and an average retention rate (Amish children who join the church as young adults) of 85 percent or more.

The Amish probably won’t pass 10 billion in the early 24th Century, Steve Sailer notes:

I wrote about the Amish in 2013, including the Cochran-Harpending theory that one reason their retention rate has gone up over the generations is because they have been boiling off Amish-born individuals with genomes that don’t put up well with the Amish lifestyle, that the Amish have been breeding themselves for their favorite trait: “plainness.”

Now it has finished the job, and released predicted structures for more than 200m proteins

Sunday, July 31st, 2022

In November 2020, the AI group DeepMind announced it had developed a program called AlphaFold that could rapidly predict how chains of amino acids fold up into complex shapes:

Last year, DeepMind published the protein structures for 20 species — including nearly all 20,000 proteins expressed by humans — on an open database. Now it has finished the job, and released predicted structures for more than 200m proteins.

“Essentially, you can think of it as covering the entire protein universe. It includes predictive structures for plants, bacteria, animals, and many other organisms, opening up huge new opportunities for AlphaFold to have an impact on important issues, such as sustainability, food insecurity, and neglected diseases,” said Demis Hassabis, DeepMind’s founder and chief executive.

Scientists are already using some of its earlier predictions to help develop new medicines. In May, researchers led by Prof Matthew Higgins at the University of Oxford announced they had used AlphaFold’s models to help determine the structure of a key malaria parasite protein, and work out where antibodies that could block transmission of the parasite were likely to bind.

“Previously, we’d been using a technique called protein crystallography to work out what this molecule looks like, but because it’s quite dynamic and moves around, we just couldn’t get to grips with it,” Higgins said. “When we took the AlphaFold models and combined them with this experimental evidence, suddenly it all made sense. This insight will now be used to design improved vaccines which induce the most potent transmission-blocking antibodies.”

People who habitually compare themselves with others are more likely to have psychopathic traits

Saturday, July 30th, 2022

Social comparison orientation is significantly correlated with psychopathy, Rob Henderson explains:

In other words, people who habitually compare themselves with others are more likely to have psychopathic traits (selfishness, callousness, cynicism).

And psychopathy, in turn, was associated with more comfort with sacrificing a few to save many.

Social comparison is also associated with narcissism. People prone to comparing themselves with others agree more strongly with statements such as “I am great” and “Other people are worth nothing.”

[…]

Later, I learned that psychopaths are overrepresented among college students by a factor of four. Roughly two percent of the general population are psychopaths, compared with 8 percent of college students.

[…]

Other studies find that people who frequently compare themselves with others are more likely to experience malicious envy.

They tend to agree with statements like “If other people have something that I want for myself, I wish to take it away from them” and “Seeing other people’s achievements makes me resent them.”

[…]

Social comparers prefer to make everyone else worse off, if it means they will obtain a relative advantage.

Also unsurprisingly, social comparison was highly correlated with competitiveness (“I judge my performance on whether I do better than others rather than on just getting a good result”).

California condors can reproduce without mating

Friday, June 24th, 2022

California condors, a critically endangered species, can reproduce without mating, according to a study by conservation scientists at the San Diego Zoo Wildlife Alliance:

During a routine analysis of biological samples from the California condors in the zoo’s breeding programme, the scientists found that two condor chicks had hatched from unfertilized eggs.

[…]

Scientists confirmed that each condor chick was genetically related to its mother but neither bird was genetically related to a male.

The two birds represent the first two instances of asexual reproduction, or parthenogenesis, to be confirmed in the California condor species, the zoo said.

“This is a very rare discovery because it’s not well-known in birds in general. So it’s known in other species, in reptiles and in fish, but in birds it’s very rare, in particular in wild species,” Dr Steiner said.

Dr Steiner said the discovery was particularly surprising, because both female birds were continuously housed with fertile male partners and had already produced chicks while paired with a male.

Asexual reproduction has never before been confirmed in any avian species where the female bird had access to a mate.

[…]

Both chicks were underweight when they hatched, Dr Steiner said.

One was released into the wild and died at the age of two in 2003, while the other survived for eight years in captivity and died in 2017.

Lake Issyk Kul is the Wuhan of the Black Death

Thursday, June 16th, 2022

A new study of DNA from the “pestilence” victims in what is now northern Kyrgyzstan shows that they were indeed infected with the bacterium, Yersinia pestis, that caused the Black Death:

The Syriac engraving on the medieval tombstone was tantalizing: “This is the tomb of the believer Sanmaq. [He] died of pestilence.” Sanmaq, who was buried in 1338 near Lake Issyk Kul in what is now northern Kyrgyzstan, was one of many victims of the unnamed plague. By scrutinizing field notes and more photos from the Russian team that had excavated the graves in the 1880s, historian Philip Slavin found that at least 118 people from Sanmaq’s Central Asian trading community died in the epidemic.

Slavin was on the trail of the origin of the Black Death, which devastated Europe a decade after the Kyrgyzstan burials. But he knew the medieval diagnosis of “pestilence” encompassed many horrific diseases. “I was almost 100% certain it was the beginning of the Black Death,” says Slavin, a medieval historian at the University of Stirling. “But there was no way to prove it without DNA.”

Now, Slavin is senior author of a new study of ancient DNA from the “pestilence” victims showing they were indeed infected with the bacterium, Yersinia pestis, that caused the Black Death. The strain that killed them was ancestral to all the strains that rampaged across Europe a decade later and continued to kill for the next 500 years. The bacterium jumped from rodents to humans just before the Kyrgyzstan burials, perhaps after sudden changes in rainfall or temperature, the researchers propose this week in Nature.

“This is the place where it all started — the Wuhan of the Black Death,” says senior author and paleogeneticist Johannes Krause of the Max Planck Institute for Evolutionary Anthropology.

[…]

The strain was closely related to ones found in rodents near Issyk Kul today. The authors suggest it spilled over to humans, perhaps from a marmot, which are abundant in the Tian Shan mountain region of northern Kyrgyzstan, southern Kazakhstan, and northwestern China. Sudden changes in rainfall or temperature could have led to surges in local rodent populations and the fleas or other insects they harbor. More rodents and their pests meant more opportunities to hop to a new host—humans—and adapt to it, says population biologist Nils Christian-Stenseth of the University of Oslo, who has shown a correlation between outbreaks of plague and warm, wet weather in Central Asia. He adds: “There are many good possibilities for plague reservoirs; you have the great gerbils, marmots, voles.”

The remaining mystery, he says, is how the Black Death traveled 3500 kilometers from Central Asia to the Black Sea, where historical accounts describe the Mongolian army hurling the bodies of plague victims into the besieged city of Caffa in Crimea in 1346 in an early form of biological warfare.

The meticulous archaeological records for each Kyrgyzstan grave offer hints, Slavin says. Many people were buried with pearls, coins, and other goods from the Indian Ocean, the Mediterranean, and Iran; some were apparently traders. As they traveled, their camel wagons may have harbored rats and fleas, long considered likely vectors for plague.

Participants lost one-fifth of their body weight

Tuesday, June 7th, 2022

In a 72-week trial in participants with obesity, tirzepatide — a novel glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist — provided substantial and sustained reductions in body weight. Participants lost one-fifth of their body weight.

They were Twentysomethings with a lot of time on their hands and nothing better to do

Friday, June 3rd, 2022

An interesting pattern recurs across the careers of great scientists, Dwarkesh Patel notes, an annus mirabilis (miracle year) in which they make multiple, seemingly independent breakthroughs in the span of a single year or two:

Einstein had his annus mirabilis in 1905. While he was still a patent clerk, he wrote four papers that revolutionized our understanding of the photoelectric effect, Brownian motion, and special relativity.

Newton’s annus mirabilis came to him between 1665 and 1666, when Cambridge responded to the Bubonic plague by sending its students home to quarantine. During that time, Newton, aged 22, developed the theory of gravity along with the language of calculus required to express it.

[…]

Many other great scientists — Copernicus, Darwin, von Neumann, and Gauss — also seem to have had an annus mirabilis.

Miracle years happen outside of pure science too. In his memoir, Linus Torvalds talks about how he spent the summer before turning 21 reading an operating systems textbook cover to cover, how later that year he built a terminal emulation program just for fun, and how he spent all his time working on this program until pretty soon it morphed into a full operating system called Linux. That was his annus mirabilis.

Even writers have miracle years. Just recently, the popular fantasy author Brandon Sanderson announced that in the year or two since the pandemic began, he has secretly written five extra novels in addition to the ones his fans knew he was writing.

Perhaps, he suggests, there’s a brief window in a person’s life where he has the intelligence, curiosity, and freedom of youth but also the skills and knowledge of age:

These conditions only coincide at some point in a person’s twenties. It wouldn’t be surprising if the combination of fluid intelligence (which declines steeply after your 20s) and crystalized intelligence (which accumulates slowly up till your 50s and 60s) is highest during this time. Stephan and Levine (1993) find that most Nobel laureates do their prize winning work in their late 20s or early 30s.

During his miracle year, Einstein was a patent clerk, Newton was a college student dismissed for quarantine, and Darwin was a trust fund kid who had just finished a long voyage aboard the HMS Beagle and still didn’t know what to do with his life. They had no obligations to research some old professor’s hobby horse using his particular technique or paradigm.

Given how many of the great scientific discoveries have come about during miracle years, he argues, we should do everything we can to help smart Twentysomethings have an annus mirabilis:

We should free them from rote menial work, prevent them from being overexposed to the current paradigm, and give them the freedom to explore far-fetched ideas without arbitrary deadlines or time-draining obligations.

It’s depressing that I have just described the opposite of a modern PhD program.