Science

study:-“smarter”-dogs-think-more-like-humans-to-overcome-their-biases

Study: “Smarter” dogs think more like humans to overcome their biases

animal behavior, animal cognition, animals, Biology, Dogs, Science, spatial bias / /

who’s a smart doggo? —

Both the shape of a dog’s head and cognitive ability determine degree of spatial bias.

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dog in a harness approaching a blue dish on the floor

Enlarge / Look at this very good boy taking a test to determine the origin of his spatial bias for a study on how dogs think.

Eniko Kubinyi

Research has shown that if you point at an object, a dog will interpret the gesture as a directional cue, unlike a human toddler, who will more likely focus on the object itself. It’s called spatial bias, and a recent paper published in the journal Ethology offers potential explanations for why dogs interpret the gesture the way that they do. According to researchers at Eötvös Loránd University in Hungary, the phenomenon arises from a combination of how dogs see (visual acuity) and how they think, with “smarter” dog breeds prioritizing an object’s appearance as much as its location. This suggests the smarter dogs’ information processing is more similar to humans.

The authors wanted to investigate whether spatial bias in dogs is sensory or cognitive, or a combination of the two. “Very early on, children interpret the gesture as pointing to the object, while dogs take the pointing as a directional cue,” said co-author Ivaylo Iotchev. “In other words, regardless of the intention of the person giving the cue, the meaning for children and dogs is different. This phenomenon has previously been observed in dogs using a variety of behavioral tests, ranging from simple associative learning to imitation, but it had never been studied per se.”

Their experimental sample consisted of dogs used in a previous 2018 study plus dogs participating specifically in the new study, for a total of 82 dogs. The dominant breeds were border collies (19), vizslas (17), and whippets (6). Each animal was brought into a small empty room with their owner and one of the experimenters present. The experimenter stood 3 meters away from the dog and owner. There was a training period using different plastic plates to teach the dogs to associate either the presence or absence of an object, or its spatial location, with the presence or absence of food. Then they tested the dogs on a series of tasks.

An object feature conditioning test involving a white round plate and a black square plate.

Enlarge / An object feature conditioning test involving a white round plate and a black square plate.

I.B. Iotchev et al., 2023

For instance, one task required dogs to participate in a maximum of 50 trials to teach them to learn a location of a treat that was always either on the left or right plate. For another task, the experimenter placed a white round plate and a black square plate in the middle of the room. The dogs were exposed to each semi-randomly but only received food in one type of plate. Learning was determined by how quickly each dog ran to the correct plate.

Once the dogs learned those first two tasks, they were given another more complicated task in which either the direction or the object was reversed: if the treat had previously been placed on the right, now it would be found on the left, and if it had previously been placed on a white round plate, it would now be found on the black square one. The researchers found that dogs learned faster when they had to choose the direction, i.e., whether the treat was located on the left or the right. It was harder for the dogs to learn whether a treat would be found on a black square plate or a white round plate.

The shorter a dog's head, the higher the

Enlarge / The shorter a dog’s head, the higher the “cephalic index” (CI).

I.B. Iotchev et al., 2023

Next the team needed to determine differences between the visual and cognitive abilities of the dogs in order to learn whether the spatial bias was sensory or cognitively based, or both. Selective breeding of dogs has produced breeds with different visual capacities, so another aspect of the study involved measuring the length of a dog’s head, which prior research has shown is correlated with visual acuity. The metric used to measure canine heads is known as the “cephalic index” (CI), defined as the ratio of the head’s maximum width multiplied by 100, then divided by the head’s maximum length.

The shorter a dog’s head, the more similar their visual acuity is to human vision. That’s because there is a higher concentration of retinal ganglion cells in the center of their field of vision, making vision sharper and giving such dogs binocular depth vision. The testing showed dogs with better visual acuity, and who also scored higher on the series of cognitive tests, also exhibited less spatial bias. This suggests that canine spatial bias is not simply a sensory matter but is also influenced by how they think. “Smarter” dogs have less spatial bias.

As always, there are a few caveats. Most notably, the authors acknowledge that their sample consisted exclusively of dogs from Hungary kept as pets, and thus their results might not generalize to stray dogs, for example, or dogs from other geographical regions and cultures. Still, “we tested their memory, attention skills, and perseverance,” said co-author Eniko Kubinyi. “We found that dogs with better cognitive performance in the more difficult spatial bias task linked information to objects as easily as to places. We also see that as children develop, spatial bias decreases with increasing intelligence.”

DOI: Ethology, 2023. 10.1111/eth.13423  (About DOIs).

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daily-telescope:-a-simple-shot-of-the-milky-way-high-above-france-and-spain

Daily Telescope: A simple shot of the Milky Way high above France and Spain

daily telescope, Science, Space / /

Daily moment of zen —

“Both the daytime and nighttime vistas there were just bloody marvelous.”

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The Milky Way Galaxy above the Pyrenees, right on the French and Spanish border.

Enlarge / The Milky Way Galaxy above the Pyrenees, right on the French and Spanish border.

bulbs_01_frizzle

Welcome to the Daily Telescope. There is a little too much darkness in this world and not enough light, a little too much pseudoscience and not enough science. We’ll let other publications offer you a daily horoscope. At Ars Technica, we’re going to take a different route, finding inspiration from very real images of a universe that is filled with stars and wonder.

Good morning. It’s December 21, and today’s image showcases our very own Milky Way Galaxy above the Pyrenees mountain range, which separates Spain from the rest of Europe.

It was sent in by a reader who captured it while hiking through the mountains and in their words bivvying—a new word for “minimalist camping” that I learned about five minutes ago. I’m jealous. Hiking through the Pyrenees and gazing at the stars at night sounds like a wonderful dream. The photographer told me they are no great astrophotographer, but that the skies were so dark and brilliant that even this single exposure photo taken with a Fuji X100 APS camera looks stunning.

“It’s still one of my favorite starry skies memories from hiking the Haute Randonnée Pyrénéenne, a high mountain route going all the way coast to coast along the French‑Spanish border,” the photographer said. “Because both the daytime and nighttime vistas there were just bloody marvelous.”

I have greatly enjoyed writing these Daily Telescope entries and seeing the amazing work you all have sent in. We’ve published everything from the very best images taken by NASA’s space telescopes down to iPhone photos. We all share the skies, and see and document them in our own way. Thank you so much for your submissions; there have been many more than we can publish. But I treasure them all and your time in sending them in. I can’t wait to see what delights the new year will bring. Until then, happy holidays, and may your stars be merry and bright.

Source: bulbs_01_frizzle

Do you want to submit a photo for the Daily Telescope? Reach out and say hello.

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great-british-bake-off’s-festive-christmas-desserts-aren’t-so-naughty-after-all

Great British Bake Off’s festive Christmas desserts aren’t so naughty after all

baking, chemistry, cooking shows, Food science, Great British Bake Off, health, nutrition, Science / /

A Christmas miracle? —

Study: Several ingredients actually reduce rather than increase risk of death or disease.

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four smiling people at a festive picnic table munching on a tasty snack

Enlarge / Great British Bake Off judges Paul Hollywood and Prue Leith (top) and presenters Alison Hammond and Noel Fielding.

Mark Bourdillon/Love Productions/Channel 4

The Great British Bake Off (TGBBO)—aka The Great British Baking Show in the US and Canada—features amateur bakers competing each week in a series of baking challenges, culminating in a single winner. The recipes include all manner of deliciously decadent concoctions, including the occasional Christmas dessert. But many of the show’s Christmas recipes might not be as bad for your health as one might think, according to a new paper published in the annual Christmas issue of the British Medical Journal, traditionally devoted to more light-hearted scientific papers.

TGBBO made its broadcast debut in 2010 on the BBC, and its popularity grew quickly and spread across the Atlantic. The show was inspired by the traditional baking competitions at English village fetes (see any British cozy murder mystery for reference). Now entering its 15th season, the current judges are Paul Hollywood and Prue Leith, with Noel Fielding and Alison Hammond serving as hosts/presenters, providing (occasionally off-color) commentary. Each week features a theme and three challenges: a signature bake, a technical challenge, and a show-stopper bake.

The four co-authors of the new BMJ study—Joshua Wallach of Emory University and Yale University’s Anant Gautam, Reshma Ramachandran, and Joseph Ross—are avid fans of TGBBO, which they declare to be “the greatest television baking competition of all time.” They are also fans of desserts in general, noting that in medieval England, the Catholic Church once issued a decree requiring Christmas pudding four weeks before Christmas. Those puddings were more stew-like, containing things like prunes, raisins, carrots, nuts, spices, grains, eggs, beef, and mutton. Hence, those puddings were arguably more “healthy” than the modern take on desserts, which contain a lot more butter and sugar in particular.

But Wallach et al. wondered whether even today’s desserts might be healthier than popularly assumed and undertook an extensive review of the existing scientific literature for their own “umbrella review.” It’s actually pretty challenging to establish direct causal links in the field of nutrition, whether we’re talking about observational studies or systemic reviews and meta-analyses. For instance, many of the former focus on individual ingredients and do not take into account the effects of overall diet and lifestyle. They also may rely on self-reporting by study participants. “Are we really going to accurately report how much Christmas desserts we frantically ate in the middle of the night, after everyone else went to bed?” the authors wrote. Systemic reviews are prone to their own weaknesses and biases.

“But bah humbug, it is Christmas and we are done being study design Scrooges,” the authors wrote, tongues tucked firmly in cheeks. “We have taken this opportunity to ignore the flaws of observational nutrition research and conduct a study that allows us to feel morally superior when we happen to enjoy eating the Christmas dessert ingredients in question (eg, chocolate). Overall, we hoped to provide evidence that we need to have Christmas dessert and eat it too, or at least evidence that will inform our collective gluttony or guilt this Christmas.”

The team scoured the TGBBO website and picked 48 dessert recipes for Christmas cakes, cookies, pastries, and puddings, such as Val’s Black Forest Yule Log, or Ruby’s Boozy Chai, Cherry and Chocolate Panettones. There were 178 unique ingredients contained in those recipes, and the authors classified those into 17 overarching ingredient groups: baking soda, powder and similar ingredients; chocolate; cheese and yogurt; coffee; eggs; butter; food coloring, flavors and extracts; fruit; milk; nuts; peanuts or peanut butter; refined flour; salt; spices; sugar; and vegetable fat.

Wallach et al. identified 46 review articles pertaining to health and nutrition regarding those classes of ingredients for their analysis. That yielded 363 associations between the ingredients and risk of death or disease, although only 149 were statistically significant. Of those 149 associations, 110 (74 percent) reduced health risks while 39 (26 percent) increased risks. The most common ingredients associated with reduced risk are fruits, coffee, and nuts, while alcohol and sugar were the most common ingredients associated with increased risk.

Take Prue Leith’s signature chocolate Yule log, for example, which is “subtly laced with Irish cream liqueur.” Most of the harmful ingredient associations were for the alcohol content, which various studies have shown to increase risk of liver cancer, gastric cancer, colon cancer, gout, and atrial fibrillation. While alcohol can evaporate during cooking or baking, in this case it’s the cream filling that contains the alcohol, which is not reduced by baking. (Leith has often expressed her preference for “boozy bakes” on the show.)

By contrast, Rav’s Frozen Fantasy Cake contains several healthy ingredients, most notably almonds and passion fruit, and thus carried a significant decreased risk for disease or death. Ditto for Paul Hollywood’s Stollen, which contains almonds, milk, and various dried fruits. “Overall, without the eggs, butter, and sugar, this dessert is essentially a fruit salad with nuts,” the authors wrote. That is, of course, a significant caveat, because the eggs, butter, and sugar kinda make the dessert. But Wallach et al. note that most of the dietary studies condemning sugar focused on the nutritional effects of sugar-sweetened beverages, and none of TGBBO Christmas dessert recipes used such beverages, “no doubt because they would have resulted in bakes with a soggy bottom.”

The BMJ study has its limitations, relying as it does on evidence from prior observational studies. Wallach et al. also did not take into account how much of each ingredient was used in any given recipe. Regardless of whether the recipe called for a single berry or an entire cup of berries, that ingredient was weighted the same in terms of its protective effects countering the presumed adverse effects of butter. Would a weighted analysis have been more accurate? Sure, but it would also have been much less fun.

So, is this a genuine Christmas miracle or an amusing academic exercise in creative rationalization? Maybe we shouldn’t overthink it. “It is Christmas so just enjoy your desserts in moderation,” the authors concluded.

BMJ, 2023. DOI: 10.1136/bmj‑2023‑077166  (About DOIs).

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spacex-completes-static-fire-test-in-push-toward-third-starship-launch

SpaceX completes static fire test in push toward third Starship launch

Science, Space, spacex, starship / /

IFT-3 goes whee? —

The rocket and test equipment looked undamaged after the test.

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Ship 28 is seen after being moved to SpaceX's launch site in South Texas.

Enlarge / Ship 28 is seen after being moved to SpaceX’s launch site in South Texas.

SpaceX

Just one month after the second flight of its massive Starship rocket, SpaceX is making progress toward a third attempt.

On Wednesday, at 1: 37 pm local time in South Texas, the company performed a static fire test of the next Starship—which bears the serial number Ship 28. The test of the rocket’s six engines appeared to be nominal as the Raptors ignited for a handful of seconds. The rocket and ground support equipment looked undamaged after the test.

Also this week SpaceX rolled the booster to be used for the next attempt—Booster 10—to the launch site at its Starbase facility in South Texas. The vehicle has since been lifted onto the orbital launch mount. Presumably this rocket, too, will undergo a static fire test in the coming days.

After these tests are complete the Starship upper stage is likely to be stacked on top of the booster to complete the launch vehicle. At this point it seems likely that the hardware for “Integrated Flight Test 3” would be substantially ready to launch.

With this third flight, SpaceX will seek to fly further into a profile that will see Starship ultimately make a controlled landing into the ocean north of Kauai, Hawaii. SpaceX may also perform an in-space propellant transfer test, but this has not been confirmed.

Starship’s second launch attempt, on November 18, was notably more successful than the first attempt in April 2023. The second flight test demonstrated substantial improvements in engine reliability and provided valuable data about a challenging “hot staging” maneuver to separate the Super Heavy booster from the Starship upper stage.

Another test flight soon?

Recently Kathy Lueders, SpaceX’s general manager for the Starbase launch site near Brownsville, said the company will target the first quarter of next year for this third test flight. “It would be great if we were in the first quarter, definitely,” she said. “Elon [Musk] obviously would probably say the end of December, but I don’t think we’ll get there.”

Since the second test flight occurred, neither the company nor SpaceX founder Elon Musk has provided a technical update on what ultimately went wrong with the Starship upper stage, which failed a few minutes into its flight, or why the booster was ultimately lost after it separated from the Starship vehicle.

Booster 10, with a few holiday decorations, is rolled to the launch site in South Texas.

Enlarge / Booster 10, with a few holiday decorations, is rolled to the launch site in South Texas.

SpaceX

However, far fewer modifications have been made to the rocket hardware or the launch site ahead of this third attempt, suggesting that at least some of the problems may have been flight software-related.

SpaceX has yet to receive regulatory approval for a third launch of Starship. The Federal Aviation Administration characterized the second attempt in November as a “mishap,” while acknowledging that no injuries or public property damage were reported.

After the anomaly, the agency said, via the social media site X, that “the FAA will oversee the @SpaceX-led mishap investigation to ensure SpaceX complies with its FAA-approved mishap investigation plan and other regulatory requirements.” The FAA has provided no additional information in the month since then.

SpaceX completes static fire test in push toward third Starship launch Read More »

contact-tracing-software-could-accurately-gauge-covid-19-risk

Contact-tracing software could accurately gauge COVID-19 risk

Biology, COVID-19, epidemiology, infectious diseases, SARS-CoV-2, Science / /

As it turns out, epidemiology works —

Time spent with infected individuals is a key determinant of risk.

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A woman wearing a face mask and checking her phone.

It’s summer 2021. You rent a house in the countryside with a bunch of friends for someone’s birthday. The weather’s gorgeous that weekend, so mostly you’re all outside—pool, firepit, hammock, etc.—but you do all sleep in the same house. And then on Tuesday, you get an alert on your phone that you’ve been exposed to SARS-CoV-2, the virus that causes COVID-19. How likely are you to now have it?

To answer that question, a group of statisticians, data scientists, computer scientists, and epidemiologists in the UK analyzed 7 million people who were notified that they were exposed to COVID-19 by the NHS COVID-19 app in England and Wales between April 2021 and February 2022. They wanted to know if—and how—these app notifications correlated to actual disease transmission. Analyses like this can help ensure that an app designed for the next pathogen could retain efficacy while minimizing social and economic burdens. And it can tell us more about the dynamics of SARS-CoV-2 transmission.

Over 20 million quarantine requests

The NHS COVID-19 app was active on 13 to 18 million smartphones per day in 2021. It used Bluetooth signals to estimate the proximity between those smartphones while maintaining privacy and then alerted people who spent 15 minutes or more at a distance of 2 meters or less from a confirmed case. This led to over 20 million such alerts, each of which came with a request to quarantine—quite a burden.

The researchers found that the app did, in fact, accurately translate the duration and proximity of a COVID-19 exposure to a relevant epidemiological risk score. The app assessed a contact’s risk by multiplying the length of contact, the proximity of contact, and the infectiousness of the index case as determined by how long it had been since the index case started showing symptoms or tested positive.

There was an increasing probability of reported infection as the app’s risk score increased: more contacts whom the app deemed were at a high transmission risk did go on to test positive for COVID-19 within the following two weeks than those who were notified but had lower risk levels. (That’s positive tests that were reported by using the app. Some of the high-risk people probably did not test at all, did not report their test results, or did not report them within the allotted time. So this is an underestimation of the correlation between notification of risk and infection.)

More exposure = higher risk

When the researchers separated the factors contributing to the risk of an exposure, they found that duration was the most important indicator. Household exposures accounted for 6 percent of all contacts but 41 percent of transmissions.

One caveat: The app didn’t record any contextual variables that are known to impact transmission risk, like if people live in an urban or rural area, was the meeting indoors or outdoors, was it during the week or over the weekend, was anyone vaccinated, etc. Including such data could make risk assessment more accurate.

Based on their work, the researchers suggest that an “Amber Alert” stage could have been introduced to the app, in which people deemed to have an interim degree of risk would be guided to get a PCR test rather than immediately jumping to quarantine. Including this intermediate Amber Alert population could have significantly reduced the socioeconomic costs of contact tracing while retaining its epidemiological impact or could have increased its effectiveness for a similar cost. Performing analyses like this early on in the next pandemic to determine how it is transmitted might minimize illness and strain on society.

Nature, 2023.  DOI:  10.1038/s41586-023-06952-2

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Blue Origin’s suborbital rocket flies for first time in 15 months

blue origin, Commercial space, launch, new shepard, ns-24, Science, Space / /

RTF —

An engine failure destroyed a New Shepard rocket on its previous flight.

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Blue Origin's New Shepard booster comes in for landing in West Texas at the conclusion of Tuesday's suborbital flight.

Enlarge / Blue Origin’s New Shepard booster comes in for landing in West Texas at the conclusion of Tuesday’s suborbital flight.

Blue Origin

With redesigned engine components, Blue Origin’s New Shepard rocket took off from West Texas and flew to the edge of space on Tuesday with a package of scientific research and technology demonstration experiments.

This was the first flight of Blue Origin’s 60-foot-tall (18-meter) New Shepard rocket since September 12, 2022, when an engine failure destroyed the booster and triggered an in-flight abort for the vehicle’s pressurized capsule. There were no passengers aboard for that mission, and the capsule safely separated from the failed booster and parachuted to a controlled landing.

The flight on Tuesday also didn’t carry people. Instead, Blue Origin, Jeff Bezos’s space company, lofted 33 payloads from NASA, research institutions, and commercial companies. Some of these payloads were flown again on Tuesday’s launch after failing to reach space on the failed New Shepard mission last year. Among these payloads were an experiment to demonstrate hydrogen fuel cell technology in microgravity and an investigation studying the strength of planetary soils under different gravity conditions.

Blue Origin’s capsule, mounted on top of the rocket, also flew 38,000 postcards submitted by students through Club for the Future, the company’s nonprofit.

For Tuesday’s return-to-flight mission, the New Shepard rocket ignited its BE-3PM engine and climbed away from Blue Origin’s remote launch site near Van Horn, Texas, at 10: 42 am CST (16: 42 UTC). The hydrogen-fueled engine fired for more than two minutes, then shut down as scheduled as the rocket continued coasting upward, reaching an altitude of more than 347,000 feet (106 kilometers).

The booster returned for a precision propulsive landing a short distance from the launch pad, and Blue Origin’s capsule deployed three parachutes to settle onto the desert floor, completing a 10-minute up-and-down flight.

Blue Origin has launched 24 missions with its reusable New Shepard rocket, including six flights carrying people just over the Kármán line, the internationally recognized boundary of space 100 kilometers above Earth.

“A special thank you to all of our customers who flew important science today and the students who contributed postcards to advance our future of living and working in space for the benefit of Earth,” said Phil Joyce, Blue Origin’s senior vice president for the New Shepard program, in a statement. “Demand for New Shepard flights continues to grow and we’re looking forward to increasing our flight cadence in 2024.”

Blue Origin will fly people again “soon”

It took 15 months for Blue Origin to return to flight with New Shepard, but Tuesday’s successful launch puts the company on a path to resuming human missions. Most of Blue Origin’s customers for these suborbital flights have been wealthy individuals or special guests invited to strap in for a ride to space. Blue Origin’s passengers have included Bezos, aviation pioneer Wally Funk, and actor William Shatner, eager for a taste of spaceflight. New Shepard passengers experience a few minutes of microgravity before returning to Earth.

Blue Origin hasn’t disclosed its ticket price, but seats on a New Shepard flight last year reportedly sold for $1.25 million. This is more than double the price for a seat on Virgin Galactic’s suborbital spaceship.

So when will Blue Origin start flying people again? “Following a thorough review of today’s mission, we look forward to flying our next crewed flight soon,” said Erika Wagner, a longtime Blue Origin manager who co-hosted the company’s webcast of Tuesday’s flight.

But “soon” is a conveniently vague term. In March, when Blue Origin announced the results of its investigation into last year’s launch failure, the company said it would return to flight “soon” with New Shepard. Nine months later, New Shepard finally flew again.

Engineers probing the New Shepard accident last year concluded a nozzle failure on the rocket’s BE-3PM was the direct cause of the launch failure. The engine operated at higher temperatures than expected, leading to thermal damage to the nozzle, Blue Origin announced earlier this year.

Blue Origin said corrective actions to address the cause of the failure included design changes to the engine combustion chamber and adjustments to operating parameters. These changes were expected to reduce operating temperatures. Engineers also redesigned parts of the nozzle to help it better handle thermal and dynamic loads, the company said.

In September, the Federal Aviation closed its investigation into the New Shepard launch failure, and Blue Origin targeted an uncrewed return-to-flight mission in early October. However, Ars previously reported that an additional two-month delay was caused by an issue with certifying an engine part intended for flight.

The long-term grounding of the New Shepard rocket caused speculation about the program’s future, particularly at a time when Blue Origin is ramping up preparations for the inaugural flight of the much larger orbital-class New Glenn launcher. Last year’s launch failure left Blue Origin with just one New Shepard booster in its inventory—the rocket that made its ninth flight to space on Tuesday.

This particular booster has been exclusively used for uncrewed research missions. Blue Origin hasn’t confirmed whether it has another New Shepard rocket in production for human flights.

But statements from Blue Origin officials Tuesday suggest New Shepard has a future. Wagner said Blue Origin aims to open New Shepard missions to researchers on future flights, allowing scientists to directly work with their experiments in microgravity.

Blue Origin’s suborbital rocket flies for first time in 15 months Read More »

human-brain-cells-put-much-more-energy-into-signaling

Human brain cells put much more energy into signaling

Biology, brain, frontal cortex, nerve cells, neurobiology, Science, signaling / /

Being human is hard —

Signaling molecules help modulate the brain’s overall activity.

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Image of a person staring pensively, with question marks drawn on the wall behind him.

Indian elephants have larger brains than we do (obviously). Mice have a higher brain-to-body mass ratio, and long-finned pilot whales have more neurons. So what makes humans—and more specifically, human brains—special?

As far as organs go, human brains certainly consume a ton of energy—almost 50 grams of sugar, or 12 lumps, every day. This is one of the highest energy demands relative to body metabolism known among species. But what uses up all of this energy? If the human brain is the predicted size and has the predicted number of neurons for a primate of its size, and each individual neuron uses comparable amounts of energy to those in other mammals, then its energy use shouldn’t be exceptional.

The cost of signaling

A group of neuroscientists speculated that maybe the amount of signaling that takes place within the human brain accounts for its heightened energy needs. A consequence of this would be that brain regions that are more highly connected and do more signaling will use more energy.

To test their hypothesis, the scientists started by imaging the brains of 30 healthy, right-handed volunteers between 20 and 50 years old. The imaging took place at two separate institutions, and it allowed the researchers to correlate a given brain region’s energy use (as measured by glucose metabolism) with its level of signaling and connectivity. They found that energy use and signaling scaled in tandem in all 30 brains. But certain regions stuck out. Signaling pathways in certain areas of the cortex—the front of the brain—require almost 70 percent more energy than those in sensory-motor regions.

The frontal cortex is one of the regions that expanded the most during human evolution. According to Robert Sapolsky, “What the prefrontal cortex is most about is making tough decisions in the face of temptation—gratification postponement, long-term planning, impulse control, emotional regulation. The PFC is essential for getting you to do the right thing when it is the harder thing to do.” This is the stuff that humans must constantly contend with. And energetically, it is extraordinarily costly.

Increased modulation is also key for cognition

It is not only signaling that takes energy; it is modulating that signaling, ensuring that it occurs at the appropriate levels and only at the appropriate times.

Using the Allen Human Brain Atlas, these researchers looked at gene activity in the frontal cortex. They found elevated activity of neuromodulators and their receptors. The authors note that “the human brain spends excessive energy on the long-lasting regulation of (fast) neurotransmission with (slow) neuromodulators such as serotonin, dopamine, or noradrenaline.” And also endogenous opiates. “This effect is more about setting the tone of general excitability than transferring individual bits of information,” they write.

Once they correlated energy use to signaling and slow-acting neuromodulation in the cortex, the last thing the scientists did was look at the Neurosynth project, which maps cognitive functions to brain regions. Lo and behold, the energy-hogging, highly connected, strongly modulated, and evolutionarily expanded parts of the cortex are the same ones involved in complex functions like memory processing, reading, and cognitive inhibition. This supports their idea of “an expensive signaling architecture being dedicated to human cognition.”

Science Advances, 2023.  DOI: 10.1126/sciadv.adi7632

Human brain cells put much more energy into signaling Read More »

what-turns-a-fungal-scavenger-into-a-killer?

What turns a fungal scavenger into a killer?

fungus, gene activity, molecular biology, Science / /

Fungus feeding —

Beware the sticky, tricky genetic weapons of a fungal carnivore.

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greyscale microscope image of a long, thin, unsegmented worm.

Enlarge / The fungus’ favorite food.

Some of the scariest monsters are microscopic. The carnivorous fungus Arthrobotrys oligospora doesn’t seem like much while it’s eating away at rotting wood. But when it senses a live worm, it will trap its victim and consume it alive—pure nightmare fuel.

Until now, not much was known about how the attack of the killer fungus happens on a molecular level. Researchers from Academia Sinica in Taiwan have finally found out how the gene activity of the fungus changes when a nematode creeps too close to A. oligospora. Led by molecular biologist Hung-Che Lin, the research team discovered that the fungus synthesizes a sort of worm adhesive and additional trapping proteins to get ahold of its meal. It then produces enzymes that break down the worm so it can start feasting.

Caught in a trap

A. oligospora lives in the soil and is mostly saprotrophic, meaning it feeds on decaying organic matter. But that can quickly change if it finds itself deprived of nutrients or senses a tempting nematode nearby. This is when it goes into carnivore mode.

Lin and his colleagues wanted to see what happened when the fungus, low on nutrients, was introduced to the nematode Caenorhabiditis elegans. The fungus showed a significant increase in DNA replication when it sensed the worm. This resulted in trap cells having additional copies of the genome. The trap cells reside in fungal filaments, or hyphae, and produce a specialized worm adhesive that would allow those hyphae to stick to the worm once it was caught in the trap.

What may be the most important genetic actions in helping the fungus to create a trap out of hyphae is ribosome biogenesis, which enables increased protein production. Ribosomes are where proteins are made, so their biogenesis (literally the creation of more ribosomes) controls cell growth and also determines how much protein is synthesized.

The researchers also identified a new group of proteins, now known as Trap Enriched Proteins (TEPs), which were the most commonly produced proteins in fungal trap cells. These seemed to contribute to trap function rather than formation.

“Given TEP protein localization to the surface of trap cells, we hypothesized that TEPs may be critical for the function of the traps,” they said in a study recently published in PLoS Biology. “Adding C. elegans… leads to their immediate capture.”

As the fungus put more effort into creating a trap and forming worm adhesive, it deprioritized activities that are not really involved in the process. Segments of DNA that usually help A. oligospora digest dead matter were down-regulated, meaning there was lower gene activity on these segments in response to the fungus sensing the worm. When a worm came close to A. oligospora, the fungus showed an up-regulation of genes that produce proteases, or enzymes that break down proteins.

Can’t get out

Additional other genes didn’t see changes in activity until the worm was already caught. Once C. elegans entered the trap that A. oligospora had set with a sticky net of hyphae, the team noticed an increase in the production of proteins that weaken prey. These proteins are able to manipulate the cells of their prey so those cells function differently, potentially providing a way for the pathogen to break in and take over. The fungus then uses proteases to digest nematodes that get stuck in its hyphae.

A. oligospora has over 400 genes that encode proteins that control its interactions with other organisms. When the introduction of a nematode made the fungus go carnivorous, more than half of these started to behave differently. These proteins weaken C. elegans through a variety of mechanisms. To give one example, some of them fight off antimicrobial peptides produced by the nematode.

The adhesive synthesized by the fungus, now thought to have a close association with TEP proteins, may have no effect on humans but is a superglue for worms that binds hyphae to their flesh. They have no way of worming their way out of being eaten alive.

This experiment might have been ghastly for the nematodes involved, but it was a breakthrough for Lin’s team. They have now identified an entire new group of genes that make a fungal trap function. Their findings with A. oligospora could be compared to the gene activity of other pathogenic fungi, including those that destroy crops, so an improved generation of antifungals might someday be influenced by this microscopic horror movie.

PLOS Biology, 2023.  DOI: 10.1371/journal.pbio.3002400

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Daily Telescope: Tracking the Sun’s path every day across the sky

daily telescope, Science, Space / /

On the horizon —

The image is a vivid demonstration of the changing of the seasons.

–

The path of the Sun over Germany.

Enlarge / The path of the Sun over Germany.

Frank Niessen/IAU OAE

Welcome to the Daily Telescope. There is a little too much darkness in this world and not enough light, a little too much pseudoscience and not enough science. We’ll let other publications offer you a daily horoscope. At Ars Technica, we’re going to take a different route, finding inspiration from very real images of a universe that is filled with stars and wonder.

Good morning. It’s December 18, and today’s photo is an homage to the forthcoming winter solstice—which will visit the Northern Hemisphere on Thursday evening.

This image was a second-place finisher in a recent competition by the International Astronomical Union’s Office of Education. This year’s contest welcomed astrophotography enthusiasts at all skill levels, including images taken with smartphones.

The image, created by Frank Niessen, was captured in Germany between the summer solstice and winter solstice in 2018. It combines images taken at different times of day over the course of six months, and each curve tracks the Sun’s path across the sky on a particular day. Gaps indicate cloudy days. The image was captured using a simple pinhole camera fashioned from a coffee can. I find the effect stunning.

Stay warm out there in the Northern Hemisphere, y’all.

Source: Frank Niessen

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This “smoking gun” killed the McDonald’s ice cream hackers’ startup

DMCA, DMCA abuse, ice cream, mcdonalds, Policy, Science, syndication / /
Vanilla Soft Serve Ice Cream Cone

A little over three years have passed since McDonald’s sent out an email to thousands of its restaurant owners around the world that abruptly cut short the future of a three-person startup called Kytch—and with it, perhaps one of McDonald’s best chances for fixing its famously out-of-order ice cream machines.

Until then, Kytch had been selling McDonald’s restaurant owners a popular Internet-connected gadget designed to attach to their notoriously fragile and often broken soft-serve McFlurry dispensers, manufactured by McDonald’s equipment partner Taylor. The Kytch device would essentially hack into the ice cream machine’s internals, monitor its operations, and send diagnostic data over the Internet to an owner or manager to help keep it running. But despite Kytch’s efforts to solve the Golden Arches’ intractable ice cream problems, a McDonald’s email in November 2020 warned its franchisees not to use Kytch, stating that it represented a safety hazard for staff. Kytch says its sales dried up practically overnight.

Now, after years of litigation, the ice-cream-hacking entrepreneurs have unearthed evidence that they say shows that Taylor, the soft-serve machine maker, helped engineer McDonald’s Kytch-killing email—kneecapping the startup not because of any safety concern, but in a coordinated effort to undermine a potential competitor. And Taylor’s alleged order, as Kytch now describes it, came all the way from the top.

On Wednesday, Kytch filed a newly unredacted motion for summary adjudication in its lawsuit against Taylor for alleged trade libel, tortious interference, and other claims. The new motion, which replaces a redacted version from August, refers to internal emails Taylor released in the discovery phase of the lawsuit, which were quietly unsealed over the summer. The motion focuses in particular on one email from Timothy FitzGerald, the CEO of Taylor parent company Middleby, that appears to suggest that either Middleby or McDonald’s send a communication to McDonald’s franchise owners to dissuade them from using Kytch’s device.

“Not sure if there is anything we can do to slow up the franchise community on the other solution,” FitzGerald wrote on October 17, 2020. “Not sure what communication from either McD or Midd can or will go out.”

In their legal filing, the Kytch co-founders, of course, interpret “the other solution” to mean their product. In fact, FitzGerald’s message was sent in an email thread that included Middleby’s then COO, David Brewer, who had wondered earlier whether Middleby could instead acquire Kytch. Another Middleby executive responded to FitzGerald on October 17 to write that Taylor and McDonald’s had already met the previous day to discuss sending out a message to franchisees about McDonald’s lack of support for Kytch.

But Jeremy O’Sullivan, a Kytch co-founder, claims—and Kytch argues in its legal motion—that FitzGerald’s email nonetheless proves Taylor’s intent to hamstring a potential competitor. “It’s the smoking gun,” O’Sullivan says of the email. “He’s plotting our demise.”

Although FitzGerald’s email doesn’t actually order anyone to act against Kytch, the company’s motion argues that Taylor played a key role in what happened next. It’s an “ambiguous yet direct message to his underlings,” argues Melissa Nelson, Kytch’s other co-founder. “It’s just like a mafia boss giving coded instructions to his team to whack someone.”

On November 2, 2020, a little over two weeks after FitzGerald’s open-ended suggestion that perhaps a “communication” from McDonald’s or Middleby to franchisees could “slow up” adoption of “the other solution,” McDonald’s sent out its email blast cautioning restaurant owners not to use Kytch’s product.

The email stated that the Kytch gadget “allows complete access to all aspects of the equipment’s controller and confidential data”—meaning Taylor’s and McDonald’s data, not the restaurant owners’ data; that it “creates a potential very serious safety risk for the crew or technician attempting to clean or repair the machine”; and finally, that it could cause “serious human injury.” The email concluded with a warning in italics and bold: “McDonald’s strongly recommends that you remove the Kytch device from all machines and discontinue use.”

This “smoking gun” killed the McDonald’s ice cream hackers’ startup Read More »

daily-telescope:-one-of-the-most-stunning-andromeda-photos-i’ve-ever-seen

Daily Telescope: One of the most stunning Andromeda photos I’ve ever seen

daily telescope, Science, Space / /

Gorgeous galaxy —

The image is the result of 100 hours of observing.

–

The Andromeda Galaxy.

Enlarge / The Andromeda Galaxy.

The Association of Widefield Astrophotographers

Welcome to the Daily Telescope. There is a little too much darkness in this world and not enough light, a little too much pseudoscience and not enough science. We’ll let other publications offer you a daily horoscope. At Ars Technica, we’re going to take a different route, finding inspiration from very real images of a universe that is filled with stars and wonder.

Good morning. It’s December 15, and I have a real treat for you today. This is an image of the Andromeda Galaxy, the nearest major galaxy to our Milky Way. Astronomers believe our galaxy is shaped much as this one is.

The photograph comes from a group that calls itself the Association of Widefield Astrophotographers, and the photo was a 100-hour project by six participants in the United States, Poland, and the United Kingdom. They collected data over several months to produce the image.

According to the organization, “Our goal with this project was to prove that very expensive equipment and dark skies aren’t required to create unique images of faint objects. Since most of us are high schoolers and college students with a passion for astronomy, our summer jobs did not allow us to afford the expensive gear used by most astrophotographers.”

Most participants worked within a city, with light pollution levels ranging from Bortle 4 to Bortle 9. While it would be difficult for an individual to reveal the faint structures in this image, they said that by working together with other astrophotographers, they could produce such a result. It is truly extraordinary.

Source: The Association of Widefield Astrophotographers

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X-ray imaging of The Night Watch reveals previously unknown lead layer

art, art conservation, Dutch Golden Age, Dutch masters, operation night watch, Physics, rembrandt, Science, The Night Watch, X-Ray imaging / /

The latest from Operation Night Watch —

Rembrandt may have used lead-rich oil to prep his canvas and protect it from humidity.

–

The Nightwatch, or Militia Company of District II under the Command of Captain Frans Banninck Cocq (1642)

Enlarge / Rembrandt’s The Night Watch underwent many chemical and mechanical alterations over the last 400 years.

Public domain

Rembrandt’s The Night Watch, painted in 1642, is the Dutch master’s largest surviving painting, known particularly for its exquisite use of light and shadow. A new X-ray imaging analysis of the masterpiece has revealed an unexpected lead layer, perhaps applied as a protective measure while preparing the canvas, according to a new paper published in the journal Science Advances. The work was part of the Rijksmuseum’s ongoing Operation Night Watch, the largest multidisciplinary research and conservation project for Rembrandt’s famous painting, devoted to its long-term preservation.

The famous scene depicted in The Night Watch—officially called Militia Company of District II under the Command of Captain Frans Banninck Cocq—was not meant to have taken place at night. Rather, the dark appearance is the result of the accumulation of dirt and varnish over four centuries, as the painting was subject to various kinds of chemical and mechanical alterations.

For instance, in 1715, The Night Watch was moved to Amsterdam’s City Hall (now the Royal Palace on Dam Square). It was too large for the new location, so the painting was trimmed on all four sides, and the trimmed pieces were never found (although in 2021, AI was used to re-create the original full painting). The objective of Operation Night Watch is to employ a wide variety of imaging and analytical techniques to better understand the materials Rembrandt used to create his masterpiece and how those materials have changed over time.

As previously reported, past analyses of Rembrandt’s paintings identified many pigments the Dutch master used in his work, including lead white, multiple ochres, bone black, vermilion, madder lake, azurite, ultramarine, yellow lake, and lead-tin yellow, among others. The artist rarely used pure blue or green pigments, with Belshazzar’s Feast being a notable exception. (The Rembrandt Database is the best resource for a comprehensive chronicling of the many different investigative reports.)

Earlier this year, the researchers at Operation Night Watch found rare traces of a compound called lead formate in the painting. They scanned about half a square meter of the painting’s surface with X-ray powder diffraction mapping (among other methods) and analyzed tiny fragments from the painting with synchrotron micro X-ray probes. This revealed the presence of the lead formates—surprising in itself, but the team also identified those formates in areas where there was no lead pigment, white, or yellow. It’s possible that lead formates disappear fairly quickly, which could explain why they have not been detected in paintings by the Dutch Masters until now. But if that is the case, why didn’t the lead formate disappear in The Night Watch? And where did it come from in the first place? 

Hoping to answer these questions, the team whipped up a model of “cooked oils” from a 17th century recipe, which called for mixing and heating linseed oil and lead oxide, then adding hot water to the reacting mixture. They analyzed those model oils with synchrotron radiation. The results supported their hypothesis that the oil used for light parts of the painting was treated with an alkaline lead drier. The fact that The Night Watch was revarnished with an oil-based varnish in the 18th century complicates matters, as this may have provided a fresh source of formic acid, such that different regions of the painting rich in lead formates may have formed at different times in the painting’s history.

This latest paper sheds more light on the painting by focusing on the preparatory layers applied to the canvas. It’s known that Rembrandt used a quartz-clay ground for The Night Watch—the first time he had done so, perhaps because the colossal size of the painting “motivated him to look for a cheaper, less heavy and more flexible alternative for the ground layer” than the red earth, lead white, and cerussite he was known to use on earlier paintings, the authors suggested.

The Night Watch via the correlated synchrotron-based X-ray fluorescence and ptychographic tomography of a paint sample, supported by a macroscale X-ray fluorescence scan of the whole painting.” height=”439″ src=”https://cdn.arstechnica.net/wp-content/uploads/2023/12/nightwatch4-640×439.jpg” width=”640″>

Enlarge / A so far unknown lead-containing impregnation ‘layer’ was discovered in Rembrandt’s The Night Watch via the correlated synchrotron-based X-ray fluorescence and ptychographic tomography of a paint sample, supported by a macroscale X-ray fluorescence scan of the whole painting.

Fréderique Broers

Per the authors, this is the first time that 3D X-ray imaging techniques have been used: X-ray fluorescence and X-ray ptychographic nano-tomography applied to an embedded paint fragment comprised of only the quartz-clay ground. The authors maintain that microscale analysis of historical paintings usually relies on 2D imaging techniques (e.g., light microscopy, scanning electron microscopy, synchrotron radiation spectroscopy), which only yield partial information about the size, shape, and distribution of pigment particles below the visible surface.

The 3D methods capture more detail by comparison, revealing the presence of an unknown (and unexpected) lead-containing layer located just underneath the ground layer. The authors suggest that this could be due to using a lead compound added to the oil used to prepare the canvas as a drying additive—perhaps to protect the painting from the damaging effects of humidity. (Usually a glue sizing was used before applying the ground layer.)

The Night Watch originally hung in the “great hall” of a musketeer shooting range in Amsterdam and faced windows. The authors note that since the Middle Ages, red lead in oil has been used to preserve stone, wood, and metal against humidity, and one contemporary source mentions using lead-rich oil instead of the typical glue to keep the canvas from separating after years of exposure in humid environments. And that newly discovered lead layer could be the reason for the unusual lead protrusions in areas of The Night Watch with no other lead-containing compounds in the paint. It’s possible that lead migrated into the painting’s ground layer from that lead-oil preparatory layer below.

DOI: Science Advances, 2023. 10.1126/sciadv.adj9394  (About DOIs).

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