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Science

Adult ADHD May Be Associated With an Increased Risk of Dementia, Study Finds (msn.com) 25

A new study found that adult ADHD "may take a toll on the brain and is linked to a higher likelihood of developing dementia," reports the Washington Post: A study published in JAMA Network Open reported that being diagnosed with ADHD as an adult is associated with a 2.77-fold increased risk of dementia.

The study only showed an association and doesn't tell us whether ADHD is a direct cause of cognitive decline. But the results suggest that "if you do have attention-deficit disorder, you're going to have more trouble with normal brain aging," said Sandra Black, a cognitive neurologist at Sunnybrook Research Institute in Toronto who was not involved in the study. "It adds another risk factor...."

Notably, of the 730 participants with adult ADHD, 13.2 percent (96 participants) were diagnosed with dementia. In contrast, of the 108,388 participants without adult ADHD, just 7 percent (7,630 participants) developed dementia. Intriguingly, adults with ADHD who were taking a psychostimulant medication such as Ritalin or Adderall did not have an increased risk of developing dementia compared with those not taking medication. Only 22.3 percent of people with ADHD had taken a psychostimulant medication at any point.

The Post also notes the work of Sara Becker, a postdoctoral research associate at the University of Calgary. "In a 2023 systematic review, Becker and her colleagues identified only seven previous studies investigating the link between ADHD and neurodegenerative diseases such as dementia, most of which found that adult ADHD conferred a higher dementia risk."
The research highlights the importance of seeking care — and the need for more research. Treatment with psychostimulant medications may attenuate the risk, said Stephen Levine, a professor at the University of Haifa's School of Public Health in Israel and the lead author of the study. Lifestyle changes, such as better sleep and staying socially engaged, can also lower risk for dementia....

A 2020 landmark study by the Lancet Commission highlighted 12 modifiable factors for dementia that, if addressed, could mitigate the risk of dementia by up to 40 percent. Some of these factors are hearing loss, excessive alcohol intake and smoking.

Other lifestyle changes that lower your risk of demential include keeping up your physical activity, and eating a Mediterranean diet, the Post reports (citing cognitive neurologist Sandra Black).

An estimated 3 percent of adults have ADHD.
Google

Google Can Turn ANC Earbuds Into a Heart Rate Monitor With No Extra Hardware (9to5google.com) 20

Abner Li reports via 9to5Google: Google today detailed its research into audioplethysmography (APG) that adds heart rate sensing capabilities to active noise canceling (ANC) headphones and earbuds "with a simple software upgrade." Google says the "ear canal [is] an ideal location for health sensing" given that the deep ear artery "forms an intricate network of smaller vessels that extensively permeate the auditory canal."

This audioplethysmography approach works by "sending a low intensity ultrasound probing signal through an ANC headphone's speakers. This signal triggers echoes, which are received via on-board feedback microphones. We observe that the tiny ear canal skin displacement and heartbeat vibrations modulate these ultrasound echoes." A model that Google created works to process that feedback into a heart rate reading, as well as heart rate variability (HRV) measurement. This technique works even with music playing and "bad earbuds seals." However, it was impacted by body motion, and Google countered with a multi-tone approach that serves as a calibration tool to "find the best frequency that measures heart rate, and use only the best frequency to get high-quality pulse waveform."

Google performed two sets of studies with 153 people that found APG "achieves consistently accurate heart rate (3.21% median error across participants in all activity scenarios) and heart rate variability (2.70% median error in inter-beat interval) measurements." Compared to existing HR sensors, it's not impacted by skin tones. Ear canal size and "sub-optimal seal conditions" also do not impact accuracy. Google believes this is a better approach than putting traditional photoplethysmograms (PPG) and electrocardiograms (ECG) sensors, as well as a microcontroller, in headphones/earbuds: "this sensor mounting paradigm inevitably adds cost, weight, power consumption, acoustic design complexity, and form factor challenges to hearables, constituting a strong barrier to its wide adoption."

Australia

New Agreement Enables US Launches From Australian Spaceports (spacenews.com) 24

Jeff Foust reports via SpaceNews: The governments of Australia and the United States have signed an agreement that could allow American rockets to launch from Australian spaceports, although it is unclear how much demand there is for them. The U.S. State Department announced Oct. 26 that the two countries signed a technology safeguards agreement (TSA) regarding space launches from Australia. The agreement provides the "legal and technical framework" for American launches from Australian facilities while protecting sensitive technologies.

The TSA is required to allow the export of U.S.-built launch vehicles to Australia. Industry officials in Australia said the agreement will allow spaceport projects there to sign long-awaited deals to host launches by American companies. [...] The precise demand for Australian launch sites from American launch companies remains unclear. The ELA statement included an illustration of four small launch vehicles from ABL Space Systems, Astra, Phantom Space and Vaya Space, as well as Rocket Lab's Neutron medium-lift rocket.
"We hear regularly from both the U.S. government and industry of their demand for this capability in Australia," said Jeremy Hallett, executive chairman of the Space Industry Association of Australia, in a statement. "This agreement removes the blockage stopping this demand being met by Australian space industry and we look forward to the new business opportunities that will emerge for the industry."
Medicine

Breakthrough Kidney Stone Procedure Makes It Possible For Astronauts To Travel To Mars (komonews.com) 70

An anonymous reader quotes a report from KOMO News: A groundbreaking medical procedure for those with kidney stones will soon be offered at the University of Washington after more than two decades of research. It will also give astronauts the go ahead they need from NASA to travel to Mars. It's a groundbreaking procedure to get rid of painful stones while you're awake, no anesthesia needed. "This has the potential to be game changing," said Dr. Kennedy Hall with UW Medicine. Still being run through clinical trials at UW Medicine, the procedure called burst wave lithotripsy uses an ultrasound wand and soundwaves to break apart the kidney stone. Ultrasonic propulsion is then used to move the stone fragments out, potentially giving patients relief in 10 minutes or less.

This technology is also making it possible for astronauts to travel to Mars, since astronauts are at a greater risk for developing kidney stones during space travel. It's so important to NASA, the space agency has been funding the research for the last 10 years. "They could potentially use this technology while there, to help break a stone or push it to where they could help stay on their mission and not have to come back to land," said Harper.
The research has been published in the Journal of Urology.
Earth

Scientists Call Out Rogue Emissions From China at Global Ozone Summit (nature.com) 60

Efforts to curb emissions of a powerful greenhouse gas commonly produced as a by-product of refrigerant manufacture might be falling short, and it seems eastern China is a major culprit. Nature: The hydrofluorocarbon gas, HFC-23, is around 14,700 times as powerful as carbon dioxide at warming the globe and has long been the subject of national and international climate-change mitigation efforts. Those efforts gained new traction nearly a decade ago when China and India -- the world's largest producers of the chemical -- agreed to dial down its emissions. New research, however, confirms that emissions continued to rise in subsequent years, and an analysis of data from atmospheric-monitoring stations suggests that factories in eastern China are responsible for nearly half of the total.

The rogue emissions are one of several air-pollution sources under discussion at the latest meeting of the Montreal Protocol, held in Nairobi, Kenya, this week. Signed in 1987, the Montreal Protocol is generally considered the most effective international environmental treaty in history, having halted the destruction of the ozone layer while also slowing down global warming. But scientists have often played a role, scanning the atmosphere for chemicals, such as ozone-depleting chlorofluorocarbons (CFCs), that governments have agreed to phase out. "Science has been instrumental in evaluating compliance under the treaty," says Megan Lickley, a climate scientist at Georgetown University in Washington DC.

Science

Gene-Editing Trial on Three Individuals for HIV Cure Yields Uncertain Result 16

Antonio Regaladoarchive, reporting for MIT Technology Review: The gene-editing technology CRISPR has been used to change the genes of human babies, to modify animals, and to treat people with sickle-cell disease. Now scientists are attempting a new trick: using CRISPR to permanently cure people of HIV. In a remarkable experiment, a biotechnology company called Excision BioTherapeutics says it added the gene-editing tool to the bodies of three people living with HIV and commanded it to cut, and destroy, the virus wherever it is hiding. The early-stage study is a probing step toward the company's eventual goal of curing HIV infection with a single intravenous dose of a gene-editing drug. Excision, which is based in San Francisco, says the first patient received treatment about a year ago.

This week, doctors involved in the study reported at a meeting in Brussels that the treatment appeared safe and did not have major side-effects. However, they withheld early data about the treatment's effects, leaving outside experts guessing whether it had worked. "This is an exceptionally ambitious and important trial," says Fyodor Urnov, a genome-editing expert at the University of California, Berkeley, who believes it "would be good to know sooner than later" what the effect was -- "including, potentially, no effect."

A failure wouldn't come as a surprise to anyone familiar with HIV. It has proved a devious adversary: there is still no vaccine, even 40 years after the virus was identified in 1983. Still, pharmaceutical companies did develop antiretroviral drugs, which stop the virus from copying itself. Taking these pills lets people with HIV live normal lives. But if they stop, the virus will quickly rebound and, if left unchecked, cause the fatal syndrome of infections and cancers known as AIDS. One reason the virus can't be fully wiped out with drugs alone is that it inserts its genetic material into the DNA of our cells, leaving behind hidden copies that can restart the infection.
Medicine

Around 20 Minutes of Exercise a Day May Balance Out the Harms of Sitting, Study Finds (nbcnews.com) 79

A new study published in the British Journal of Sports Medicine finds that about 22 minutes a day of moderate to vigorous activity may combat the negative effects of prolonged sitting. Furthermore, they researchers found that as a person's activity level increases, the risk of dying prematurely from any cause goes down. NBC News reports: In the study, researchers looked at information from nearly 12,000 people ages 50 and older in four datasets from Norway, Sweden and the United States. In those datasets, the participants wore movement detection devices on their hips for 10 hours a day for at least four days. All of the individuals included in the new study were tracked for at least two years. In the new analysis, the researchers accounted for factors, including medical conditions, that could've affected risk of early death. About half of the participants spent 10 1/2 hours or more sedentary each day.

When the researchers linked the participants' information with death registries in the different countries, they found that over an average of five years, 805 people, or 17%, had died. Of those who died, 357, or 6%, had spent less than 10 1/2 hours a day seated, while 448 averaged 10 1/2 hours or more sedentary. Sitting for more than 12 hours a day, the researchers found, was associated with a 38% increased risk of death as compared to eight hours, but only among those who managed to get less than 22 minutes of moderate to vigorous activity a day.

The risk of death went down with increasing amounts of physical activity. An extra 10 minutes a day translated into a 15% lower risk of death among those spending fewer than 10 1/2 hours seated and a 35% lower risk among those who spent more than 10 1/2 hours sedentary each day. Lower intensity activity only made a difference among participants who spent 12 or more hours sitting every day.
The study's lead author, Edvard Sagelv, a researcher at The Arctic University of Norway, broke the findings down into manageable terms. "Think of it: only 20 minutes of this a day is enough, meaning, a small stroll of 10 minutes twice a day -- like jumping off the bus one stop before your actual destination to work and then when taking the bus back home, jumping off one stop before."
AI

Pigeons Problem-Solve Similarly To Artificial Intelligence, Research Shows (theguardian.com) 54

According to a new study published in iScience, the way pigeons problem-solve matches artificial intelligence. The Guardian reports: In the study, 24 pigeons were given a variety of visual tasks, some of which they learned to categorize in a matter of days, and others in a matter of weeks. The researchers found evidence that the mechanism that pigeons used to make correct choices is similar to the method that AI models use to make the right predictions. "Pigeon behavior suggests that nature has created an algorithm that is highly effective in learning very challenging tasks," said Edward Wasserman, study co-author and professor of experimental psychology at the University of Iowa. "Not necessarily with the greatest speed, but with great consistency."

On a screen, pigeons were shown different stimuli, like lines of different width, placement and orientation, as well as sectioned and concentric rings. Each bird had to peck a button on the right or left to decide which category they belonged to. If they got it correct, they got food, in the form of a pellet; if they got it wrong, they got nothing. "Pigeons don't need a rule," said Brandon Turner, lead author of the study and professor of psychology at Ohio State University. Instead they learn through trial and error. For example, when they were given a visual, say "category A", anything that looked close to that they also classified as "category A", tapping into their ability to identify similarities.

Over the course of the experiments, pigeons improved their ability to make right choices from 55% to 95% of the time when it came to some of the simpler tasks. Presented with a more complex challenge, their accuracy went up from 55% to 68%. In an AI model, the main goal is to recognize patterns and make decisions. Pigeons, as research shows, can do the same. Learning from consequences, when not given a food pellet, pigeons have a remarkable ability to correct their errors. Similarity function is also at play for pigeons, by using their ability to find resemblance between two objects. "With just those two mechanisms alone, you can define a neural network or an artificial intelligent machine to basically solve these categorization problems," said Turner. "It stands to reason that the mechanisms that are present in the AI are also present in the pigeon."

Mars

Mars Has a Surprise Layer of Molten Rock Inside (nature.com) 35

Alexandra Witze reports via Nature: A meteorite that slammed into Mars in September 2021 has rewritten what scientists know about the planet's interior. By analysing the seismic energy that vibrated through the planet after the impact, researchers have discovered a layer of molten rock that envelops Mars's liquid-metal core. The finding, reported today in two papers in Nature, means that the Martian core is smaller than previously thought. It also resolves some lingering questions about how the red planet formed and evolved over billions of years.

The discovery comes from NASA's InSight mission, which landed a craft with a seismometer on Mars's surface. Between 2018 and 2022, that instrument detected hundreds of "marsquakes' shaking the planet. In July 2021, on the basis of the mission's observations of 11 quakes, researchers reported that the liquid core of Mars seemed to have a radius of around 1,830 kilometers3. That was bigger than many scientists were expecting. And it suggested that the core contained surprisingly high amounts of light chemical elements, such as sulfur, mixed with iron. But the September 2021 meteorite impact "unlocked everything," says Henri Samuel, a geophysicist at the Institute of Earth Physics of Paris and lead author of one of today's papers1. The meteorite struck the planet on the side opposite to where InSight was located. That's much more distant than the marsquakes that InSight had previously studied, and allowed the probe to detect seismic energy traveling all the way through the Martian core4. "We were so excited," says Jessica Irving, a seismologist at the University of Bristol, UK, and a co-author of Samuel's paper.

For Samuel, it was an opportunity to test his idea that a molten layer of rock surrounds Mars's core5. The way the seismic energy traversed the planet showed that what scientists had thought was the boundary between the liquid core and the solid mantle, 1,830 kilometers from the planet's centre, was actually a different boundary between liquid and solid. It was the top of the newfound layer of molten rock meeting the mantle (see 'Rethinking the Martian core'). The actual core is buried beneath that molten-rock layer and has a radius of only 1,650 kilometers, Samuel says. The revised core size solves some puzzles. It means that the Martian core doesn't have to contain high amounts of light elements -- a better match to laboratory and theoretical estimates. A second liquid layer inside the planet also meshes better with other evidence, such as how Mars responds to being deformed by the gravitational tug of its moon Phobos.

The second paper in Nature today2, from a team independent of Samuel's, agrees that Mars's core is enveloped by a layer of molten rock, but estimates that the core has a radius of 1,675 kilometers. The work analyzed seismic waves from the same distant meteorite impact, as well as simulations of the properties of mixtures of molten elements such as iron, nickel and sulfur at the high pressures and temperatures in the Martian core. Having molten rock right up against molten iron "appears to be unique," says lead author Amir Khan, a geophysicist at ETH Zurich. "You have this peculiarity of liquid-liquid layering, which is something that doesn't exist on the Earth." The molten-rock layer might be left over from a magma ocean that once covered Mars. As it cooled and solidified into rock, the magma would have left behind a deep layer of radioactive elements that still release heat and keep rock molten at the base of the mantle, Samuel says.

Biotech

Can Humans Have Babies In Space? SpaceBorn United Wants To Find Out (technologyreview.com) 105

An anonymous reader quotes a report from MIT Technology Review: Egbert Edelbroek was acting as a sperm donor when he first wondered whether it's possible to have babies in space. Curious about the various ways that donated sperm can be used, Edelbroek, a Dutch entrepreneur, began to speculate on whether in vitro fertilization technology was possible beyond Earth -- or could even be improved by the conditions found there. Could the weightlessness of space be better than a flat laboratory petri dish? Now Edelbroek is CEO of SpaceBorn United, a biotech startup seeking to pioneer the study of human reproduction away from Earth. Next year, he plans to send a mini lab on a rocket into low Earth orbit, where in vitro fertilization, or IVF, will take place. If it succeeds, Edelbroek hopes his work could pave the way for future space settlements.

"Humanity needs a backup plan," he says. "If you want to be a sustainable species, you want to be a multiplanetary species." Beyond future space colonies, there is also a more pressing need to understand the effects of space on the human reproductive system. No one has ever become pregnant in space -- yet. But with the rise of space tourism, it's likely that it will eventually happen one day. Edelbroek thinks we should be prepared. Despite the burgeoning interest in deep space exploration and settlement, prompted in part by billionaires such as Elon Musk and Jeff Bezos, we still know very little about what happens to our reproductive biology when we're in orbit. A report released in September by the US National Academies of Science, Engineering, and Medicine points out that almost no research has been done on human reproduction in space, adding that our understanding of how space affects reproduction is "vital to long-term space exploration, but largely unexplored to date."

Some studies on animals have suggested that the various stages of reproduction -- from mating and fertilization to embryo development, implantation, pregnancy, and birth -- can function normally in space. For example, in the very first such experiment, eight Japanese medaka fish developed from egg to hatchling aboard the space shuttle Columbia in 1994. All eight survived the return to Earth and seemed to behave normally.Yet other studies have found evidence that points to potential problems. Pregnant rats that spent much of their third trimester -- a total of five days -- on a Soviet satellite in 1983 experienced complications during labor and delivery. Like all astronauts returning to Earth, the rats were exhausted and weak. Their deliveries lasted longer than usual, likely because of atrophied uterine muscles. All the pups in one of the litters died during delivery, the result of an obstruction thought to be due in part to the mother's weakened state.

To Edelbroek, these inconclusive results point to a need to systematically isolate each step in the reproductive process in order to better understand how it is affected by conditions like lower gravity and higher radiation exposure. The mini lab his company developed is designed to do exactly that. It is about the size of a shoebox and uses microfluidics to connect a chamber containing sperm to a chamber containing an egg. It can also rotate at different speeds to replicate the gravitational environment of Earth, the moon, or Mars. It is small enough to fit inside a capsule that can be housed on top of a rocket and launched into space.After the egg has been fertilized in the device, it splits into two cells, each of which divides again to form four cells and so on. After five to six days, the embryo reaches a stage known as a blastocyst, which looks like a hollow ball. At this point, the embryos in the mini lab will be cryogenically frozen for their return to Earth.

NASA

NASA's First Two-Way End-to-End Laser Communications System (nasa.gov) 14

NASA is demonstrating laser communications on multiple missions -- showcasing the benefits infrared light can have for science and exploration missions transmitting terabytes of important data. NASA: The International Space Station is getting a "flashy" technology demonstration this November. The ILLUMA-T (Integrated Laser Communications Relay Demonstration Low Earth Orbit User Modem and Amplifier Terminal) payload is launching to the International Space Station to demonstrate how missions in low Earth orbit can benefit from laser communications. Laser communications uses invisible infrared light to send and receive information at higher data rates, providing spacecraft with the capability to send more data back to Earth in a single transmission and expediting discoveries for researchers.

Managed by NASA's Space Communications and Navigation (SCaN) program, ILLUMA-T is completing NASA's first bi-directional, end-to-end laser communications relay by working with the agency's LCRD (Laser Communications Relay Demonstration). LCRD launched in December 2021 and is currently demonstrating the benefits of laser communications from geosynchronous orbit by transmitting data between two ground stations on Earth in a series of experiments. Some of LCRD's experiments include studying atmospheric impact on laser signals, confirming LCRD's ability to work with multiple users, testing network capabilities like delay/disruption tolerant networking (DTN) over laser links, and investigating improved navigation capabilities.

Books

Scientist, After Decades of Study, Concludes: We Don't Have Free Will (phys.org) 347

Corinne Purtill reports via Phys.Org: Before epilepsy was understood to be a neurological condition, people believed it was caused by the moon, or by phlegm in the brain. They condemned seizures as evidence of witchcraft or demonic possession, and killed or castrated sufferers to prevent them from passing tainted blood to a new generation. Today we know epilepsy is a disease. By and large, it's accepted that a person who causes a fatal traffic accident while in the grip of a seizure should not be charged with murder. After more than 40 years studying humans and other primates, Sapolsky has reached the conclusion that virtually all human behavior is as far beyond our conscious control as the convulsions of a seizure, the division of cells or the beating of our hearts.

This means accepting that a man who shoots into a crowd has no more control over his fate than the victims who happen to be in the wrong place at the wrong time. It means treating drunk drivers who barrel into pedestrians just like drivers who suffer a sudden heart attack and veer out of their lane. "The world is really screwed up and made much, much more unfair by the fact that we reward people and punish people for things they have no control over," Sapolsky said. "We've got no free will. Stop attributing stuff to us that isn't there."

Sapolsky, a MacArthur "genius" grant winner, is extremely aware that this is an out-there position. Most neuroscientists believe humans have at least some degree of free will. So do most philosophers and the vast majority of the general population. Free will is essential to how we see ourselves, fueling the satisfaction of achievement or the shame of failing to do the right thing. Saying that people have no free will is a great way to start an argument. This is partly why Sapolsky, who describes himself as "majorly averse to interpersonal conflict," put off writing his new book "Determined: A Science of Life Without Free Will." [...]

Analyzing human behavior through the lens of any single discipline leaves room for the possibility that people choose their actions, he says. But after a long cross-disciplinary career, he feels it's intellectually dishonest to write anything other than what he sees as the unavoidable conclusion: Free will is a myth, and the sooner we accept that, the more just our society will be. "Determined," which comes out today, builds on Sapolsky's 2017 bestseller "Behave: The Biology of Humans at Our Best and Worst," which won the Los Angeles Times Book Prize and a slew of other accolades. The book breaks down the neurochemical influences that contribute to human behaviors, analyzing the milliseconds to centuries preceding, say, the pulling of a trigger or the suggestive touch on an arm. "Determined" goes a step further. If it's impossible for any single neuron or any single brain to act without influence from factors beyond its control, Sapolsky argues, there can be no logical room for free will.

Science

Scientists Create World's Most Water-Resistant Surface (theguardian.com) 46

Sammy Gecsoyler reports via The Guardian: A research team in Finland, led by Robin Ras, from Aalto University, and aided by researchers from the University of Jyvaskyla, has developed a mechanism to make water droplets slip off surfaces with unprecedented efficacy. Cooking, transportation, optics and hundreds of other technologies are affected by how water sticks to surfaces or slides off them, and adoption of water-resistant surfaces in the future could improve many household and industrial technologies, such as plumbing, shipping and the auto industry. The research team created solid silicon surfaces with a "liquid-like" outer layer that repels water by making droplets slide off surfaces. The highly mobile topcoat acts as a lubricant between the product and the water droplets.

Sakari Lepikko, the lead author of the study, which was published in Nature Chemistry on Monday, said: "Our work is the first time that anyone has gone directly to the nanometer-level to create molecularly heterogeneous surfaces." By carefully adjusting conditions, such as temperature and water content, inside a reactor, the team could fine-tune how much of the silicon surface the monolayer covered. Using the new method, the team ended up creating the slipperiest liquid surface in the world. According to Lepikko, the discovery promises to have implications wherever droplet-repellent surfaces are needed. This covers hundreds of examples from daily life to industrial environments.

Science

One Month After Experimental Pig Heart Transplant, Doctors Say They See No Signs of Rejection or Infection 37

One month after an experimental procedure to transplant the heart of a genetically modified pig into a patient with end-stage heart disease, doctors say the heart is functioning on its own and shows no signs of rejection. From a reoport: In September, 58-year-old Lawrence Faucette underwent the surgery, only the second ever performed in a human. Faucette's heart disease and pre-existing conditions made him ineligible for a traditional human heart transplant. "The physicians taking care of him believe his heart function is excellent," said Dr. Bartley Griffith, director of the Cardiac and Lung Transplant Program at the University of Maryland School of Medicine who performed the surgery. "We've had no evidence of infections and no evidence of rejection right now."

Dr. Muhammad Mohiuddin, director of UMMC's Cardiac Xenotransplantation Program, said in an update shared on Friday, "we are withdrawing all the drugs that were initially supporting his heart. So now his heart is doing everything on its own." Mohiuddin said the focus now is making sure that Faucette has the strength to perform routine functions. "We are working very hard with our physical therapy team who are spending a lot of time helping him regain the strength that he's lost during last one month of hospital stay," Mohiuddin said.
Science

Masks Work. So What Went Wrong with a Highly Publicized COVID Mask Analysis? (scientificamerican.com) 501

A Harvard professor on the history of science looks at our response to the pandemic, criticizing "a report that gave the false impression that masking didn't help." From Scientific American: The group's report was published by Cochrane, an organization that collects databases and periodically issues "systematic" reviews of scientific evidence relevant to health care. This year it published a paper addressing the efficacy of physical interventions to slow the spread of respiratory illness such as COVID... The review of studies of masking concluded that the "results were inconclusive..." [and] it was "uncertain whether wearing [surgical] masks or N95/P2 respirators helps to slow the spread of respiratory viruses." Still, the authors were also uncertain about that uncertainty, stating that their confidence in their conclusion was "low to moderate." You can see why the average person could be confused... The Cochrane finding was not that masking didn't work but that scientists lacked sufficient evidence of sufficient quality to conclude that they worked...

Cochrane has made this mistake before. In 2016 a flurry of media reports declared that flossing your teeth was a waste of time... The answer demonstrates a third issue with the Cochrane approach: how it defines evidence. The organization states that its reviews "identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria." The problem is what those eligibility criteria are. Cochrane Reviews base their findings on randomized controlled trials (RCTs), often called the "gold standard" of scientific evidence. But many questions can't be answered well with RCTs, and some can't be answered at all...

In fact, there is strong evidence that masks do work to prevent the spread of respiratory illness. It just doesn't come from RCTs. It comes from Kansas. In July 2020 the governor of Kansas issued an executive order requiring masks in public places. Just a few weeks earlier, however, the legislature had passed a bill authorizing counties to opt out of any statewide provision. In the months that followed, COVID rates decreased in all 24 counties with mask mandates and continued to increase in 81 other counties that opted out of them... Cochrane ignored this epidemiological evidence because it didn't meet its rigid standard.

I have called this approach "methodological fetishism," when scientists fixate on a preferred methodology and dismiss studies that don't follow it. Sadly, it's not unique to Cochrane. By dogmatically insisting on a particular definition of rigor, scientists in the past have landed on wrong answers more than once.

Vox also points out that while Cochrane's review included 78 studies, "only six were actually conducted during the Covid-19 pandemic... Instead, most of them looked at flu transmission in normal conditions, and many of them were about other interventions like hand-washing.

"Only two of the studies are about Covid and masking in particular. Furthermore, neither of those studies looked directly at whether people wear masks, but instead at whether people were encouraged or told to wear masks by researchers."
NASA

NASA Transmits Patches to the Two Voyager Probes Launched in 1977 (nasa.gov) 74

"It's not every day that you get to update the firmware on a device that was produced in the 1970s," writes Hackaday, "and rarely is said device well beyond the boundaries of our solar system.

"This is however exactly what the JPL team in charge of the Voyager 1 & 2 missions are facing, as they are in the process of sending fresh firmware patches over to these amazing feats of engineering."

From NASA's announcement: One effort addresses fuel residue that seems to be accumulating inside narrow tubes in some of the thrusters on the spacecraft. The thrusters are used to keep each spacecraft's antenna pointed at Earth. This type of buildup has been observed in a handful of other spacecraft... In some of the propellant inlet tubes, the buildup is becoming significant. To slow that buildup, the mission has begun letting the two spacecraft rotate slightly farther in each direction [almost 1 degree] before firing the thrusters. This will reduce the frequency of thruster firings... While more rotating by the spacecraft could mean bits of science data are occasionally lost — akin to being on a phone call where the person on the other end cuts out occasionally — the team concluded the plan will enable the Voyagers to return more data over time.

Engineers can't know for sure when the thruster propellant inlet tubes will become completely clogged, but they expect that with these precautions, that won't happen for at least five more years, possibly much longer. "This far into the mission, the engineering team is being faced with a lot of challenges for which we just don't have a playbook," said Linda Spilker, project scientist for the mission as NASA's Jet Propulsion Laboratory in Southern California. "But they continue to come up with creative solutions."

But that's not the only issue: The team is also uploading a software patch to prevent the recurrence of a glitch that arose on Voyager 1 last year. Engineers resolved the glitch, and the patch is intended to prevent the issue from occurring again in Voyager 1 or arising in its twin, Voyager 2...

In 2022, the onboard computer that orients the Voyager 1 spacecraft with Earth began to send back garbled status reports, despite otherwise continuing to operate normally... The attitude articulation and control system (AACS) was misdirecting commands, writing them into the computer memory instead of carrying them out. One of those missed commands wound up garbling the AACS status report before it could reach engineers on the ground.

The team determined the AACS had entered into an incorrect mode; however, they couldn't determine the cause and thus aren't sure if the issue could arise again. The software patch should prevent that.

"This patch is like an insurance policy that will protect us in the future and help us keep these probes going as long as possible," said JPL's Suzanne Dodd, Voyager project manager. "These are the only spacecraft to ever operate in interstellar space, so the data they're sending back is uniquely valuable to our understanding of our local universe."

Since their launch in 1977, NASA's two Voyager probes have travelled more than 12 billion miles (each!), and are still sending back data from beyond our solar system.
Mars

Could a Mud Lake on Mars Be Hiding Signs of Ancient Life? (space.com) 19

"Planetary scientists want to search for biosignatures in what they believe was once a Martian mud lake," reports Space.com: After scientists carefully studied what they believe are desiccated remnants of an equatorial mud lake on Mars, their study of Hydraotes Chaos suggests a buried trove of water surged onto the surface. If researchers are right, then this flat could become prime ground for future missions seeking traces of life on Mars... More generally, scientists suggest surface water on Mars froze over about 3.7 billion years ago as the atmosphere thinned and the surface cooled. But underground, groundwater might still have remained liquid in vast chambers. Moreover, life forms might have abided in those catacombs — leaving behind traces of their existence. Only around 3.4 billion years ago did that system of aquifers break down in Hydraotes Chaos, triggering floods of epic proportions that dumped mountains' worth of sediment onto the surface, the study suggests. Future close-up missions could someday examine that sediment for biosignatures...

Alexis Rodriguez, a senior scientist at the Planetary Science Institute in Arizona, and his colleagues pored over images of Hydraotes Chaos taken by NASA's Mars Reconnaissance Orbiter in search of more clues. In the midst of the chaos terrain's maelstrom lies a calm circle of relatively flat ground. This plain is pockmarked with cones and domes, with hints of mud bubbling from below — suggesting that sediment did not arrive via a rushing flash flood, but instead rose from underneath. Based on simulations, the authors suggest Hydraotes Chaos overlaid a reservoir of buried biosignature-rich water — potentially in the form of thick ice sheets.

Ultimately — potentially from the Red Planet's internal heat melting the ice — that water bubbled up to the surface and created a muddy lake. As the water dissipated, it would have left behind all those tantalizing biosignatures. Curiously, that water might have remained underground even after those megafloods. In fact, the authors' results suggest the sediment on the surface of this mud lake dates from only around 1.1 billion years ago: long after most of Mars's groundwater ought to have flooded out, and certainly long after Mars was habitable. With that timeline in mind, Rodriguez and colleagues plan to analyze what lies under the surface of the lake. That, Rodriguez tells Space.com, would allow scientists to establish when in Martian history the planet might have hosted life.

Rodriguez tells Space.com that this region is now "under consideration" for testing with an under-development NASA instrument called Extractor for Chemical Analysis of Lipid Biomarkers in Regolith (EXCALIBR) — that could test extraterrestrial rocks for biomarkers like lipids.
Science

California Supervolcano: Caltech's 'Chilling' Discovery In Long Valley Caldera (scitechdaily.com) 26

An anonymous reader shared this report from SciTechDaily: Since the 1980s, researchers have observed significant periods of unrest in a region of California's Eastern Sierra Nevada mountains characterized by swarms of earthquakes as well as the ground inflating and rising by almost half an inch per year during these periods. The activity is concerning because the area, called the Long Valley Caldera, sits atop a massive dormant supervolcano... What is behind the increased activity in the last few decades? Could it be that the area is preparing to erupt again? Or could the uptick in activity actually be a sign that the risk of a massive eruption is decreasing?

To answer these questions, Caltech researchers have created the most detailed underground images to date of the Long Valley Caldera, reaching depths up to 10 kilometers within the Earth's crust. These high-resolution images reveal the structure of the earth beneath the caldera and show that the recent seismic activity is a result of fluids and gases being released as the area cools off and settles down.

The work was conducted in the laboratory of Zhongwen Zhan (PhD '14), professor of geophysics. A paper describing the research was published on October 18 in the journal Science Advances. "We don't think the region is gearing up for another supervolcanic eruption, but the cooling process may release enough gas and liquid to cause earthquakes and small eruptions," says Zhan. "For example, in May 1980, there were four magnitude 6 earthquakes in the region alone."

Space

JWST's Disconnect With Cosmology Models Linked to 'Bursty Star Formations' (spokesman.com) 18

Images from the James Webb Space Telescope "don't match scientists' models of how the universe formed," reports the Washington Post.

"But it might not be time to dump the standard model of cosmology yet. " A recent analysis in the Astrophysical Journal Letters suggests an explanation for the surprisingly massive-seeming galaxies: brilliant, extremely bright bursts of newborn stars.

The galaxies photographed by the telescope looked far too mature and large to have formed so fully so soon after the universe began, raising questions about scientists' assumptions of galaxy formation. But when researchers ran a variety of computer simulations of the universe's earliest days, they discovered that the galaxies probably are not as large as they seem. Instead, they attribute their brightness to a phenomenon called "bursty star formation." As clouds of dust and debris collapse, they form dense, high-temperature cores and become stars. Bursty galaxies spit out new stars in intermittent, bright bursts instead of creating stars more consistently. Usually, these galaxies are low in mass and take long breaks between starbursts.

Because the galaxies in question look so bright in photos produced by the Webb telescope, scientists at first thought they were older and more massive. But bursty systems with the ability to produce extremely bright, abundant light may appear more massive than they really are.

"Not only does this finding explain why young galaxies appear deceptively massive, it also fits within the standard model of cosmology," explains the announcement: In the new study, Guochao Sun, who led the study, Northwestern's, Claude-André Faucher-Giguère, the study's senior author, and their team used advanced computer simulations to model how galaxies formed right after the Big Bang. The simulations produced cosmic dawn galaxies that were just as bright as those observed by the JWST...

Although other astrophysicists have hypothesized that bursty star formation could be responsible for the unusual brightness of galaxies at cosmic dawn, the Northwestern researchers are the first to use detailed computer simulations to prove it is possible. And they were able to do so without adding new factors that are unaligned with our standard model of the universe.

Space

Next Year, SpaceX Aims To Average One Launch Every 2.5 Days (arstechnica.com) 27

Stephen Clark reports via Ars Technica: Earlier this week, SpaceX launched for the 75th time this year, continuing a flight cadence that should see the company come close to 100 missions by the end of December. SpaceX plans to kick its launch rate into a higher gear in 2024. This will be largely driven by launches of upgraded Starlink satellites with the ability to connect directly with consumer cell phones, a service SpaceX calls "Starlink Direct to Cell," a company official told Ars this week. The goal next year is 12 launches per month, for a total of 144 Falcon rocket flights. Like this year, most of those missions will be primarily devoted to launching Starlink broadband satellites. So far in 2023, more than 60 percent of SpaceX's launches have delivered the company's own Starlink satellites into orbit.

Here are some numbers. Last year, SpaceX launched 61 missions. In 2021, the number was 31. In the last 12 months, SpaceX has launched 88 Falcon rockets, plus one test flight of the company's much larger Starship rocket. SpaceX's success in recovering and reusing Falcon 9 boosters and payload fairings has been vital to making this possible. SpaceX has gone past the original goal of launching each Falcon 9 booster 10 times before a major overhaul, first to 15 flights, and then recently certifying boosters for up to 20 missions. Technicians can swap out parts like engines, fins, landing legs, and valves that malfunction in flight or show signs of wear. With so many launches planned next year, 20 flights is probably not a stopping point. "We might go a little higher," the SpaceX official said.
SpaceX may also see an uptick in missions for external customers, like NASA, the U.S. Space Force, and commercial companies. "External demand for Falcon 9 and Falcon Heavy launches is 'steady,' the official said, but some customers that had launches scheduled for this year encountered delays with their satellites, moving them into 2024."

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