Space radiation comes in two different flavors

Saturday, March 16th, 2024

The Orion spacecraft that is supposed to take humans on a Moon fly-by mission this year has a heavily shielded (solar) storm shelter for the crew, but shelters like that aren’t sufficient for a flight to Mars:

Space radiation comes in two different flavors. Solar events like flares or coronal mass ejections can cause very high fluxes of charged particles (mostly protons). They’re nasty when you have no shelter but are relatively easy to shield against since solar protons are mostly low energy. The majority of solar particle events flux is between 30 Mega-electronVolts to 100 MeV and could be stopped by Orion-like shelters.

Then there are galactic cosmic rays: particles coming from outside the Solar System, set in motion by faraway supernovas or neutron stars. These are relatively rare but are coming at you all the time from all directions. They also have high energies, starting at 200 MeV and going to several GeVs, which makes them extremely penetrating. Thick masses don’t provide much shielding against them. When high-energy cosmic ray particles hit thin shields, they produce many lower-energy particles—you’d be better off with no shield at all.

The particles with energies between 70 MeV and 500 MeV are responsible for 95 percent of the radiation dose that astronauts get in space. On short flights, solar storms are the main concern because they can be quite violent and do lots of damage very quickly. The longer you fly, though, GCRs become more of an issue because their dose accumulates over time, and they can go through pretty much everything we try to put in their way.

The reason nearly none of this radiation can reach us is that Earth has a natural, multi-stage shielding system. It begins with its magnetic field, which deflects most of the incoming particles toward the poles. A charged particle in a magnetic field follows a curve—the stronger the field, the tighter the curve. Earth’s magnetic field is very weak and barely bends incoming particles, but it is huge, extending thousands of kilometers into space.

Anything that makes it through the magnetic field runs into the atmosphere, which, when it comes to shielding, is the equivalent of an aluminum wall that’s 3 meters thick. Finally, there is the planet itself, which essentially cuts the radiation in half since you always have 6.5 billion trillion tons of rock shielding you from the bottom.

To put that in perspective, the Apollo crew module had on average 5 grams of mass per square centimeter standing between the crew and radiation. A typical ISS module has twice that, about 10 g/cm2. The Orion shelter has 35–45 g/cm2, depending on where you sit exactly, and it weighs 36 tons. On Earth, the atmosphere alone gives you 810 g/cm2—roughly 20 times more than our best shielded spaceships.

The two options are to add more mass—which gets expensive quickly—or to shorten the length of the mission, which isn’t always possible. So solving radiation with passive mass won’t cut it for longer missions, even using the best shielding materials like polyethylene or water. This is why making a miniaturized, portable version of the Earth’s magnetic field was on the table from the first days of space exploration. Unfortunately, we discovered it was far easier said than done.

[…]

In 1967, Richard H. Levy and Francis W. French delivered a report saying that plasma and electrostatic shields were promising, but they both needed 60 million volts to work—even by today’s standards, that number is ridiculous.

[…]

Electrostatic shields had been ignored because they required those 60 million volts that French and Levy talked about in their report. In 2008, NASA’s Kennedy Space Center and ASRC Aerospace Corporation proposed an electrostatic shield based on three huge Van de Graaff generators connected to an outer ring that looked like something taken straight from a Vulcan Combat Cruiser. It was undeniably cool, but it was completely infeasible. Fry and Madzunkov had to find something more realistic, so they turned to advanced modeling software and huge GPU clusters.

[…]

events’ radiation and 15 percent of cosmic rays using just 1 million volts, not 60 million. And you no longer needed to haul a full-size power plant with you. “Using grid-like, porous structures we not only brought the weight down, but we also brought the needed power down from megawatts to 100 watts,” said Fry. Power savings that big were possible because plasmas, which normally bleed away volts, did not accumulate on these porous structures—they flew right through them.

First-generation biofuel operations use food crops like corn, soy, and sugarcane as raw materials, or feedstocks

Monday, February 12th, 2024

Introducing a simple, renewable chemical to the pretreatment step can finally make biofuel production both cost-effective and carbon neutral:

Lignin is one of the main components of plant cell walls. It provides plants with greater structural integrity and resiliency from microbial attacks. However, these natural properties of lignin also make it difficult to extract and utilize from the plant matter, also known as biomass.

[…]

To overcome the lignin hurdle, [UC Riverside Associate Research Professor Charles] Cai invented CELF, which stands for co-solvent enhanced lignocellulosic fractionation. It is an innovative biomass pretreatment technology.

“CELF uses tetrahydrofuran or THF to supplement water and dilute acid during biomass pretreatment. It improves overall efficiency and adds lignin extraction capabilities,” Cai said. “Best of all, THF itself can be made from biomass sugars.”

[…]

First-generation biofuel operations use food crops like corn, soy, and sugarcane as raw materials, or feedstocks. Because these feedstocks divert land and water away from food production, using them for biofuels is not ideal.

Second-generation operations use non-edible plant biomass as feedstocks. An example of biomass feedstocks includes wood residues from milling operations, sugarcane bagasse, or corn stover, all of which are abundant low-cost byproducts of forestry and agricultural operations.

According to the Department of Energy, up to a billion tons per year of biomass could be made available for the manufacture of biofuels and bioproducts in the US alone, capable of displacing 30% of our petroleum consumption while also creating new domestic jobs.

Because a CELF biorefinery can more fully utilize plant matter than earlier second-generation methods, the researchers found that a heavier, denser feedstock like hardwood poplar is preferable over less carbon-dense corn stover for yielding greater economic and environmental benefits.

Using poplar in a CELF biorefinery, the researchers demonstrate that sustainable aviation fuel could be made at a break-even price as low as $3.15 per gallon of gasoline equivalent. The current average cost for a gallon of jet fuel in the U.S. is $5.96.

We can read the scrolls

Monday, February 5th, 2024

Vesuvius ChallengeOn March 15th, 2023, Nat Friedman, Daniel Gross, and Brent Seales launched the Vesuvius Challenge, and now they are announcing the Grand Prize winners:

Two thousand years ago, a volcanic eruption buried an ancient library of papyrus scrolls now known as the Herculaneum Papyri.

In the 18th century the scrolls were discovered. More than 800 of them are now stored in a library in Naples, Italy; these lumps of carbonized ash cannot be opened without severely damaging them. But how can we read them if they remain rolled up?

[…]

Scrolls from the Institut de France were imaged at the Diamond Light Source particle accelerator near Oxford. We released these high-resolution CT scans of the scrolls, and we offered more than $1M in prizes, put forward by many generous donors.

[…]

Our team of eminent papyrologists worked day and night to review 15 columns of text in anonymized submissions, while the technical team audited and reproduced the submitted code and methods.

There was one submission that stood out clearly from the rest. Working independently, each member of our team of papyrologists recovered more text from this submission than any other. Remarkably, the entry achieved the criteria we set when announcing the Vesuvius Challenge in March: 4 passages of 140 characters each, with at least 85% of characters recoverable. This was not a given: most of us on the organizing team assigned a less than 30% probability of success when we announced these criteria! And in addition, the submission includes another 11 (!) columns of text — more than 2000 characters total.

The results of this review were clear and unanimous: the Vesuvius Challenge Grand Prize of $700,000 is awarded to a team of three for their excellent submission. Congratulations to Youssef Nader, Luke Farritor, and Julian Schilliger!

[…]

Scholars might call it a philosophical treatise. But it seems familiar to us, and we can’t escape the feeling that the first text we’ve uncovered is a 2000-year-old blog post about how to enjoy life.

Why are so many NFL quarterbacks blue-eyed?

Thursday, February 1st, 2024

I knew that Steve Sailer had asked, “Why are so many NFL quarterbacks blue-eyed?” but I hadn’t looked into it, until Razib Khan linked to a 2014 piece:

Intrigued, I did a little research with the help of Google and NFL.com, and it turns out that over 80% of Superbowls have been won by Quarterback with blue eyes, a ratio of over 4 to 1. What’s more, of the twenty-three modern era quarterbacks in the NFL Hall of Fame, twenty-one have light colored eyes. That is not a misprint. That is over 90%. If you were to include guaranteed first ballot HOFer’s Peyton Manning, Bret Favre and Tom Brady, it climbs to an astounding twenty four of twenty six. (In 2014, no quarterbacks were voted as HOF semifinalist; however, of the six quarterbacks eligible, only sky blue-eyed Phil Simms has won a Superbowl, setting a record for completion percentage in the game and winning the Superbowl MVP award).

Only two Hall of Fame quarterbacks have brown eyes, Warren Moon and Otto Graham. For any coach in the NFL (or vegas bookie), this should be a stunning revelation. According to a New York Times article by Douglas Belkin, blue eyes make up less than twenty percent of the people born in the U.S. today, about 1 in 6. Even when you concede the fact that racism played a large part in the earlier days of the NFL (and some would say even now), and therefore use only statics from the population of Caucasian Americans for comparison, blue eyes are still only found at a rate of approximately 34%, or 1 in 3. Only in Estonia and some Scandinavian countries does the percentage of blue eyes even approach that of the NFL Hall of Fame’s 90+%.

[…]

According to my wife, (a certified retinal angiographer who has worked with America’s top retinal surgeons), it is well known amongst eye surgeons and ophthalmologists that there are dramatic physiological differences between light and dark colored eyes. In fact, light eyes, or those with less melanin present, are at a greater risk for macular degeneration as well as reacting very differently to certain stimuli than dark colored eyes. For example, when given dilation drops before an exam or surgery, it is common knowledge that brown eyes require more medication, sometimes up to twice as much, take longer to dilate and stay dilated for a shorter period of time than their lighter colored counterparts. If eye color accounts for this diverse a reaction to a temporary medication like dilation drops, it stands to reason that they would react differently to other stimuli as well, like air temperature or perhaps even the bluish tint of the winter sun. This concept has largely been ignored by the athletic community.

[…]

If any other occupation required a similar visual skill as the NFL quarterback, the men often admiringly referred to as gunslingers, then perhaps actual sharp shooters, or what we might call a sniper today, is a good place to look for validation. As it turns out, it was once common knowledge that the best sharp shooters possessed light colored eyes. In a famous 1890 short story by Ambrose Bierce, An Occurrence at Owl Creek Bridge, the author writes, “He observed that it was a grey eye and remembered having read that grey eyes were keenest, and that all famous marksmen had them.” In reality, it was so well known light colored eyes made for the best snipers that the Canadian military conducted tests in the late 1800’s on the very subject. They not only found lighter eyes seem to perform better as snipers, but certain colors can be seen at great distances better than others resulting in a change of their infantry’s uniform color from red to grey, the very first official camouflage and, what would suddenly appear to be a huge advantage for the Oakland Raiders. (Jim Plunkett finally comes into focus).

Drug and chemical warfare was sort of a parallel arms race

Friday, January 26th, 2024

Tripping on Utopia by Benjamin BreenUC Santa Cruz historian Benjamin Breen’s Tripping on Utopia: Margaret Mead, the Cold War, and the Troubled Birth of Psychedelic Science tracks the souring of the idealism once associated with the study of psychedelic drugs in the 20th century:

More concretely, it focuses on the intertwined lives of two cultural anthropologists — Mead and Gregory Bateson, who were married for 14 years — and the extraordinary circle of social scientists, psychoanalysts, artists and spies who gathered around them from the 1930s through the ’70s.

[…]

People in the ’20s and ’30s genuinely thought science could, for instance, lead to the formation of a world government.

Mead and Bateson thought that scientists would lead the vanguard of a revolution in bringing the wisdom and the experiences of other cultures into the modern world, the creation of a sort of global culture that would allow for some form of transcendence. World War II really changed their view.

So there was a strong belief that in the aftermath of the atomic bomb that the way to win a war was to never end up in actual combat. Psychological warfare was the way to go — you know, basically the idea of game theory. For instance, the American side imagined, “What if the Soviets have a mind-altering drug and they give it to the president of the United States or slip it into the ambassador to Moscow’s drink?” That concern actually prompted parallel work by the CIA and the U.S. military. Drug and chemical warfare was sort of a parallel arms race alongside the nuclear arms race.

And that is what we mostly associate today with MKUltra. But it was much bigger than that. There were many other programs. and I barely scratched the surface. For instance, the idea of dropping aerosolized LSD over cities was something people thought about, but also [to use it] as a tool of diplomacy, a way of interrogating suspected double agents, even as a way of inuring Americans in the State Department. There were many layers of paranoia.

Generating Power on Earth From the Coldness of Deep Space

Thursday, January 25th, 2024

On a clear night you’ll feel your body cool; some of that cooling is heat radiating into space:

Removing heat this way can cool that object down tens of degrees below the temperature of its surroundings.

We can exploit the temperature difference by turning it into electricity through thermoelectric power generation. The working principle behind a thermoelectric generator is the Seebeck effect, which describes how a material develops a voltage difference in response to a temperature differential across it. We can manipulate the Seebeck effect in semiconductors by the controlled addition of impurities, or dopants.

[…]

With the ambient environment as a hot reservoir, we can use the coldness from deep space to create the cold reservoir. To do this, we send heat out to space using what we call an emitter, which cools itself to a lower temperature than its surroundings. That’s a phenomenon known as radiative cooling. Then, a thermoelectric generator situated between the cold emitter and the now-hotter ambient surroundings can produce electricity.

The emitter’s job is to radiate the heat out beyond Earth’s atmosphere. But the atmosphere is transparent only to photons of certain wavelengths. Within the mid-infrared range, which is where heat radiation from typical earthbound objects is concentrated, the most applicable atmospheric transmission band is in the 8- to 13-micrometer-wavelength range. Even some simple emitters send out heat radiation at these wavelengths. For example, if it’s insulated from ambient surroundings, black paint emits enough radiation within that band to cool a surface down by 10 degrees Celsius when exposed to the night sky.

In the wavelength range outside 8 to 13 mm, the atmosphere bounces back a substantial amount of radiation. During the daytime, solar radiation comes into the equation. More-advanced emitter designs aim to avoid the incoming radiation from the atmosphere and sunlight by ensuring that they absorb and emit only within the transparency window. The idea of using such a wavelength-selective emitter for radiative cooling dates back to the pioneering work of Claes-Göran Granqvist and collaborators in the 1980s. Just as an engineer designs a radio antenna with a specific shape and size to transmit over a certain wavelength in a certain direction, we can design an emitter using a library of materials, each with a specific shape and size, to adjust the wavelength band and direction for heat radiation. The better we do this, the more heat the emitter ejects into space and the colder the emitter can get.

Glass is a great material for an emitter. Its atomic vibrations couple strongly to radiation around the 10-micrometer wavelength, forcing the material to emit much of its heat radiation within the transmission window. Just touch a glass window at night and you’ll feel this cooling. Adding a metallic film to help reflect radiation skyward makes the emissions—and the cooling—even more effective. And structures can be specifically designed to strongly reflect the wavelengths of sunlight.

[…]

Putting all these optimizations together, we calculated that the maximum achievable power density for this technology is 2.2 W/m2. This power density is a lot lower than what can be generated with solar cells under sunlight. However, when sunlight isn’t readily available, this is pretty good; it’s significantly higher compared to what can be achieved with many other ambient energy-harvesting schemes. For example, it’s orders of magnitude more than the less than 1 mW/m2 that can be harvested from ambient radio waves.

We all want the pill

Wednesday, January 24th, 2024

Rethinking Diabetes by Gary TaubesThe Guardian reviews Gary Taubes‘ Rethinking Diabetes: What Science Reveals About Diet, Insulin, and Successful Treatments

Gary Taubes is probably the most single-minded person I have ever met. In 2002, when he was a little-known science journalist and author of two books on scientific controversies, an article of his was published in the New York Times, headlined: What If It’s All Been a Big Fat Lie? In it, he argued that the low-fat dietary advice of the previous couple of decades wasn’t only incorrect, but actively dangerous and the reason for, as he put it, the “rampaging epidemic of obesity in America”. For Taubes, dietary fat wasn’t a problem at all. Instead, the real danger was carbohydrate, he asserted, sparking a backlash, and fuelling the ongoing conversation about what constitutes a “healthy diet”. He wasn’t the first to assert that carbs were bad (Robert Atkins got there before him), but perhaps because of his serious and scientific background — he has a physics degree from Harvard and studied aerospace engineering at Stanford — he has been a polarising figure, with as many ardent followers as detractors.

[…]

Before the discovery of insulin in the 1920s, diet was the only way to manage diabetes and although various options were tried by early practitioners, low-carb was, says Taubes, among the most popular (with medics, at least). Insulin was a gamechanger. Not only did it almost magically save the lives of children with type 1 diabetes, who would often arrive at hospital comatose and die swiftly afterwards, but it also meant that people with diabetes of both types could eat a more or less normal diet.

[…]

What Taubes would like to see is low-carb diets being offered alongside or instead of diabetes medications. “When insulin therapy started in the 1920s, they had no idea what the long-term side-effects were or what the long-term consequences of living with diabetes were [because most people with type 1 died],” he says. “Then doctors find out that it’s just easier to let patients eat whatever they want and give them drugs to cover them. Then it’s another five, 10 or 20 years before they start seeing the long-term complications, which they think of as long-term complications of the disease.” What he wishes scientists at the time had concluded was: “The reason we’re keeping them alive is insulin therapy. So what we’re seeing is the long-term complications of the disease as controlled by insulin therapy, and the insulin therapy might be causing the complications as much as the disease is.

“By the late 1930s, you have this tidal wave of diabetic complications: the heart disease, the atherosclerosis, the neuropathy, the kidney failure, the blindness, amputations. And nobody ties it back.” By then, the low-carb diet had fallen far from favour. “Nobody wants to eat a diet. So nobody’s being told: ‘Look, if I give you insulin, I’m going to keep you alive until you’re 30, especially if I give you a lot of insulin and you do eat your carbs. But if I tell you not to eat the carbs and we minimise the insulin use — which for type 2 could be no insulin — I might keep you alive as long as anyone else in your family.’”

In the book, which is laden with references, studies and dense historical detail, Taubes mentions case records from the 1700s in which patients on low-sugar diets beg for a medical solution, suggesting that the preference for medication over a highly prescriptive diet has been with us for a long time. “If you’re told, a pill or a diet, we all want the pill. But if you’re told a pill or a diet and the diet will keep you healthy and the pill will give you a chronic degenerative disorder where you’re still going to have these horrible complications, they are just going to be 20 to 30 years later… the pill is going to be easier, because it always is. But if you change the diet, it’s not a hypothetical change: you can put your diabetes into remission, you can stop taking these medications.”

It maintained height and stayed in the jet stream for the three-day journey across the Pacific

Monday, December 25th, 2023

Swarm Troopers by David HamblingIn December 1944, David Hambling explains (in Swarm Troopers), US military observers on the West Coast reported a wave of unidentified flying objects:

On investigation, these were found to be paper balloons thirty feet across.

[…]

The balloons were filled with hydrogen and had a complex mechanical gondola. At first, they were thought to be weather balloons, but after reports of unexplained explosions, one was captured intact and found to be carrying incendiary bombs. This was the Japanese Fu-Go or “windship weapon.”

[…]

It was months before intelligence revealed they had flown all the way from Japan. The Japanese were taking advantage of a newly discovered natural phenomenon, the jet stream, a narrow ribbon of fast-moving air at high altitudes.

[…]

A clockwork mechanism controlled the release of a set of small sandbags around the rim of the gondola. Whenever the balloon fell too low, it dropped another sandbag. If it rose too high, which might cause it to burst, a valve vented a small amount of hydrogen. This control system meant it maintained height and stayed in the jet stream for the three-day journey across the Pacific.

[…]

The aim was to start forest fires in the heavily wooded regions of the Pacific Northwest. This would spread panic and divert resources from the war effort. The target was big enough that even this rough method of aiming had a chance of success.

[…]

US analysts estimated the Fu-Go cost $ 200 each, at a time when a P-51 Mustang was $ 50,000. The little balloons were hard to intercept. There was not enough metal on them to show up on radar, and they were surprisingly fast at high altitude, making them difficult to catch. Only around twenty were shot down.

[…]

At least four hundred Fu-Go made it to America, scattered from Mexico to Canada. The number would have been greater but for a problem with antifreeze in the altitude control system. This was too weak and the altitude controls were apt to freeze up, leaving Fu-Go to slowly descend into the waters of the Pacific.

After the war, the US considered balloons:

The E77 balloon bomb was similar to the Fu-Go, but delivered an anti-crop agent in the form of feathers dipped in a bacterial or fungal culture. Like the Fu-Go it was an imprecise way of hitting a large target, but 1954 tests suggested that balloon bombs would be effective.

[…]

The US also tested long-distance balloons for photographing enemy territory, but again balloons were edged out by manned aircraft. As always, the US military took more interest in high-performance manned aircraft than small, unmanned alternatives.

The cuprates got really weird when they stopped superconducting and started resisting

Thursday, December 21st, 2023

Liyang Chen and his collaborators at Rice University measured the current flowing through an atoms-thin strand of “strange” metal and found that it flowed smoothly and evenly:

Familiar metals like tin and mercury become superconductors only when chilled to within a few degrees of absolute zero. Bednorz and Müller measured the electrical resistance in a copper-based (“cuprate”) material and saw that it vanished at a relatively balmy 35 kelvins. (For their breakthrough discovery, Bednorz and Müller pocketed a Nobel Prize just a year later.)

[…]

The cuprates got really weird when they stopped superconducting and started resisting. As all metals warm, resistance increases. Warmer temperatures mean atoms and electrons jiggle more, creating more resistance-inducing collisions as electrons shuttle current through a material. In normal metals, such as nickel, resistance rises quadratically at low temperatures — slowly at first and then faster and faster. But in the cuprates, it rose linearly: Each degree of warming brought the same increase in resistance — a bizarre pattern that continued over hundreds of degrees and, in terms of strangeness, overshadowed the material’s superconducting ability. The cuprates were the strangest metals researchers had ever seen.

[…]

The current in the gold wire crackled in the familiar way that currents made of charged quasiparticles do — like fat raindrops splattering on the car roof. But in the strange metal, current slipped quietly through the nanowire, an effect akin to the nearly silent hiss of mist. The most straightforward interpretation of the experiment is that charge in this strange metal does not flow in electron-size chunks.

Modern dogs have a bigger neocortex

Wednesday, December 13th, 2023

Because domestication was relatively recent, modern dog breeds live alongside ancient breeds, making comparison possible:

“About 80 percent of the dogs living on the planet today are what’s known as village dogs. These are free-ranging animals that live as human commensals. So they’re living within human society, but they’re not pets,” Hecht said.

Some initial findings from the lab include the discovery of neurological differences in dog breeds, including that premodern dogs on a whole have larger amygdala — the part of the brain that controls emotional processing and memory. Such heightened environmental-monitoring skills would come in handy for dogs deciding which humans to steal scraps from and which to avoid.

Modern dogs have a bigger neocortex — the part of the brain that controls motor function, perception, and reasoning. It may play a part in modern dogs’ increased behavioral flexibility, or ability to adapt to new environments.

Hecht’s lab connects personality and skill differences in dogs to six different parts of the brain: the regions controlling drive and reward; olfaction and taste; spatial navigation; social communication and coordination; fight or flight; and olfaction and vision

[…]

More than breed itself, pathways are impacted by a dog’s head shape and size. For example, Hecht’s lab has found that bigger dogs have larger neocortices than their smaller counterparts, and therefore generally are more trainable and less anxious. Dogs bred for their narrow skulls may see that impact their behavior.

“It stands to reason that if you’re manipulating the shape of a skull, you’re going to be manipulating the shape of the brain,” Hecht said.

Cold air doesn’t hold much moisture, so it dries the airways

Wednesday, December 6th, 2023

One in five competitive athletes suffers from exercise-induced bronchoconstriction, or EIB:

The numbers are even higher in endurance and winter sports. Puzzlingly, studies have found that athletes with EIB who somehow make it to the Olympics are more likely to medal. What’s so great about wheezing, chest tightness, and breathlessness?

The answer isn’t what you’re thinking. Sure, it’s possible that some athletes get a boost because an EIB diagnosis allows them to use otherwise-banned asthma medications. But there’s a simpler explanation: breathing high volumes of cold or polluted air dries out the airways, leading to an overzealous immune response and potential long-term damage. “It’s well established that high training loads and ventilatory work increase the degree of airway hyper-responsiveness and hence development of asthma and EIB,” explains Morten Hostrup, a sports scientist at the University of Copenhagen and lead author of a new review on EIB in the Scandinavian Journal of Medicine and Science in Sports. In other words, the athletes who train hard enough to podium are more likely to develop EIB as a result.

[…]

Activities with the highest risk involve sustained efforts of at least five minutes, particularly if they take place in cold or polluted air. Cold air doesn’t hold much moisture, so it dries the airways. This affects skiers, runners, and triathletes, among others. Indoor environments like pools and ice rinks are also a problem, because of the chloramines produced by pool water and exhaust from Zambonis.

[…]

Before the 1998 Winter Games, U.S. Olympic Committee physiologists examined Nagano-bound athletes to see whose airways showed abnormal constriction in response to arduous exercise. Almost a quarter of the athletes tested positive, including half the cross-country ski team.

[…]

If you do get an EIB diagnosis, your doctor can prescribe asthma medication, including inhaled corticosteroids like fluticasone and airway dilators like salbutamol. If you’re an elite athlete subject to drug testing, you’ll need to tread carefully, since some of those medications are either banned or restricted to a maximum dosage. Hostrup and his colleagues note that there’s also evidence that fish oils high in omega-3 fatty acids, vitamin C, and even caffeine might help reduce EIB symptoms. And on the non-pharmaceutical side, you can minimize the chance of an attack by doing a thorough warm-up of 20 to 30 minutes, including six to eight 30-second sprints. This can temporarily deplete the inflammatory cells that would otherwise trigger an airway-narrowing attack

The mycorrhizal fungi act as a kind of protective shield against pathogens in the soil

Tuesday, December 5th, 2023

Researchers in Switzerland treated 54 fields with Arbuscular mycorrhizal fungi (AMF), which can enhance plant nutrient uptake and reduce plant stress, to quantify the effects on maize (corn) growth, and found the results highly variable, ranging from negative 12 percent to positive 40 percent:

With few soil parameters and mainly soil microbiome indicators, we could successfully predict 86 percent of the variation in plant growth response to inoculation. The abundance of pathogenic fungi, rather than nutrient availability, best predicted (33 percent) AMF inoculation success.

More:

“On a quarter of the plots, the mycorrhizal fungi enabled up to 40 percent better yields. That’s huge,” says the study’s co-lead, Marcel van der Heijden, a soil ecologist at the University of Zurich and at Asgroscope. But there’s a catch: on a third of the plots, the yield did not increase and sometimes even decreased. The research team was initially unable to explain why this happened.

[…]

“We discovered that the inoculation functioned best when there were lots of fungal pathogens already in the soil,” says co-first author Stefanie Lutz from Agroscope, the federal center of competence for Agricultural Research.

“The mycorrhizal fungi act as a kind of protective shield against pathogens in the soil that would weaken the plants.” As a result, the normal yield can be maintained in fields where, without mycorrhizal fungi, there would have been losses. In contrast, mycorrhizal fungi had only a minor effect on fields that were not contaminated with pathogens.

“The plants there are strong anyway and grow excellently. The use of mycorrhizal fungi in such cases brings no additional benefits,” says the other first author, Natacha Bodenhausen from the Research Institute of Organic Agriculture.

The only thing remarkable about their deployments was the sheer number of artillery rounds they had fired

Thursday, November 9th, 2023

An investigation by the New York Times found that many of the troops sent to bombard the Islamic State in 2016 and 2017 returned to the United States plagued by nightmares, panic attacks, depression and, in a few cases, hallucinations:

Interviews with more than 40 gun crew veterans and their families in 16 states found that the military repeatedly struggled to determine what was wrong after the troops returned from Syria and Iraq.

All the gun crews filled out questionnaires to screen for post-traumatic stress disorder and took tests to detect signs of traumatic brain injuries from enemy explosions. But the crews had been miles away from the front lines when they fired their long-range cannons, and most never saw direct fighting or suffered the kinds of combat injuries that the tests were designed to look for.

A few gun crew members were eventually given diagnoses of PTSD, but to the crews, that didn’t make much sense. They hadn’t, in most cases, even seen the enemy.

The only thing remarkable about their deployments was the sheer number of artillery rounds they had fired.

The United States had made a strategic decision to avoid sending large numbers of ground troops to fight the Islamic State, and instead relied on airstrikes and a handful of powerful artillery batteries to, as one retired general said at the time, “pound the bejesus out of them.” The strategy worked: Islamic State positions were all but eradicated, and hardly any U.S. troops were killed.

But it meant that a small number of troops had to fire tens of thousands of high-explosive shells — far more rounds per crew member, experts say, than any U.S. artillery battery had fired at least since the Vietnam War.

Military guidelines say that firing all those rounds is safe. What happened to the crews suggests that those guidelines were wrong.

The cannon blasts were strong enough to hurl a 100-pound round 15 miles, and each unleashed a shock wave that shot through the crew members’ bodies, vibrating bone, punching lungs and hearts, and whipping at cruise-missile speeds through the most delicate organ of all: the brain.

More than a year after Marines started experiencing problems, the Marine Corps leadership tried to piece together what was happening by ordering a study of one of the hardest-hit units, Fox Battery, 2nd Battalion, 10th Marines.

The research was limited to reviewing the troops’ medical records. No Marines were examined or interviewed. Even so, the report, published in 2019, made a startling finding: The gun crews were being hurt by their own weapons.

More than half the Marines in the battery had eventually received diagnoses of traumatic brain injuries, according to a briefing prepared for Marine Corps headquarters. The report warned that the experience in Syria showed that firing a high number of rounds, day after day, could incapacitate crews “faster than combat replacements can be trained to replace them.”

The military did not seem to be taking the threat seriously, the briefing cautioned: Safety training — both for gun crews and medical personnel — was so deficient, it said, that the risks of repeated blast exposure “are seemingly ignored.”

[…]

The military for generations set maximum safe blast-exposure levels for eardrums and lungs but never for brains. Anything that didn’t leave troops dazed was generally considered safe. But that has recently changed.

Today, shooters wear hearing protection, even when shooting relatively low-power guns, like pistols, alone, outdoors, but it wasn’t that long ago that a machine-gunner was supposed to tough it out. The military didn’t address the problem until a new technology made it impossible to ignore.

Spider silk spun by silkworms

Sunday, September 24th, 2023

Scientists in China have synthesized spider silk from genetically modified silkworms, producing fibers six times tougher than Kevlar:

Previously developed processes for spinning artificial spider silk have struggled to apply a surface layer of glycoproteins and lipids to the silk to help it withstand humidity and exposure to sunlight — an anti-aging “skin layer” that spiders apply to their webs.

Genetically modified silkworms offer a solution to this problem, says Mi, since silkworms coat their own fibers with a similar protective layer.

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To spin spider silk from silkworms, Mi and his team introduced spider silk protein genes into the DNA of silkworms so that it would be expressed in their glands using a combination of CRISPR-Cas9 gene editing technology and hundreds of thousands of microinjections into fertilized silkworm eggs.

The microinjections posed “one of the most significant challenges” in the study, said Mi, but when he saw the silkworms’ eyes glowing red under the fluorescence microscope — a sign that the gene editing had been successful — he was overjoyed.

The researchers also needed to perform “localization” modifications on the transgenic spider silk proteins so that they would interact properly with proteins in the silkworm glands, ensuring that the fiber would be spun properly. To guide the modifications, the team developed a “minimal basic structure model” of silkworm silk.

“This concept of ‘localization,’ introduced in this thesis, along with the proposed minimal structural model, represents a significant departure from previous research,” says Mi. “We are confident that large-scale commercialization is on the horizon.”

Creating fractures in rocks with low permeability means that the water in the system can’t easily leak out

Tuesday, September 5th, 2023

Geothermal offers a virtually limitless, always-on source of emissions-free heat and electricity:

If the US could capture just 2% of the thermal energy available two to six miles beneath its surface, it could produce more than 2,000 times the nation’s total annual energy consumption.

But because of geological constraints, high capital costs and other challenges, we barely use it at all: today it accounts for 0.4% of US electricity generation.

To date, developers of geothermal power plants have largely been able to tap only the most promising and economical locations, like this stretch of Nevada. They’ve needed to be able to drill down to porous, permeable, hot rock at relatively low depths. The permeability of the rock is essential for enabling water to move between two human-drilled wells in such a system, but it’s also the feature that’s often missing in otherwise favorable areas.

Starting in the early 1970s, researchers at Los Alamos National Laboratory began to demonstrate that we could engineer our way around that limitation. They found that by using hydraulic fracturing techniques similar to those now employed in the oil and gas industry, they could create or widen cracks within relatively solid and very hot rock. Then they could add in water, essentially engineering radiators deep underground.

Such an “enhanced” geothermal system then basically works like any other, but it opens the possibility of building power plants in places where the rock isn’t already permeable enough to allow hot water to circulate easily. Researchers in the field have argued for decades that if we drive down the cost of such techniques, it will unlock vast new stretches of the planet for geothermal development.

A noted MIT study in 2006 estimated that with a $1 billion investment over 15 years, enhanced geothermal plants could produce 100 gigawatts of new capacity on the grid by 2050, putting it into the same league as more popular renewable sources. (By comparison, about 135 gigawatts of solar capacity and 140 gigawatts of wind have been installed across the US.)

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Creating fractures in rocks with low permeability means that the water in the system can’t easily leak out into other areas. Consequently, if you close off the well system and keep pumping in water, you can build up mechanical pressure within the system, as the fractured rock sections push against the earth.

“The fractures are able to dilate and change shape, almost like balloons,” Norbeck says.

That pressure can then be put to use. In a series of modeling experiments, Fervo found that once the valve was opened again, those balloons effectively deflated, the flow of water increased, and electricity generation surged. If they “charged it” for days, by adding water but not letting it out, it could then generate electricity for days.