Ars Technica - Science

Since 2017, a particularly dangerous strain of E. coli O157:H7 has emerged across the country to spark outbreaks, severe disease, and deaths. It spreads in various ways: via leafy greens and contaminated beef, like its relatives, but also recreational waters. Hundreds of people across 46 states have been infected, and health officials have documented at least nine separate outbreaks. One in 2018, linked to lettuce, caused over 200 infections across 37 states, killing five people and causing a severe kidney condition in 26.

Now, a sweeping genetic analysis by researchers at the Centers for Disease Control and Prevention suggests a tiny mutation in one of the bacteria's molecular weapons may be behind the strain's rise. The finding, published recently in the journal Emerging Infectious Diseases, provides insights into this clinically significant plague and its rise to prominence. It also highlights the role of the bacteria's sophisticated military tactics.

The mutated weapon is part of a complex system that E. coli and other harmful bacteria sometimes use called a Type 3 Secretion System (T3SS). This involves molecular machinery that basically functions like a syringe, complete with a long needle that is poked into the cells of its victims. The T3SS then directly injects a fleet of hostile proteins. Those proteins—called effectors—attack specific targets that collectively disable the host's defense responses and make the host more hospitable for its bacterial conqueror.

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The world of computers is dominated by binary. Silicon transistors are either conducting or they're not, and so we've developed a whole world of math and logical operations around those binary capabilities. And, for the most part, quantum computing has been developing along similar lines, using qubits that, when measured, will be found in one of two states.

In some cases, the use of binary values is a feature of the object being used to hold the qubit. For example, a technology called dual-rail qubits takes its value from which of two linked resonators holds a photon. But there are many other quantum objects that have access to far more than two states—think of something like all the possible energy states an electron could occupy when orbiting an atom. We can use things like this as qubits by only relying on the lowest two energy levels. But there's nothing stopping us from using more than two.

In Wednesday's issue of Nature, researchers describe creating qudits, the generic term for systems that hold quantum information—it's short for quantum digits. Using a system that can be in three or four possible states (qutrits and ququarts, respectively), they demonstrate the first error correction of higher-order quantum memory.

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The vast majority of people these days use some form of social media, but some develop what's known as problematic social media use (PSMU). It's not yet deemed a clinical addiction, but it does share some symptoms with addiction and substance abuse disorders. And according to a new paper published in the journal PLoS ONE, someone who exhibits PSMU is also more likely to believe in—and share—fake news online, contributing to the rampant spread of misinformation that is the bane of the 21st-century Internet.

"If someone struggles with a substance dependency, it's the decision-making process in their brain where they have difficulties stopping," co-author Dar Meshi of Michigan State University told Ars. "They take their drug and have a negative outcome: get a DUI or crash their car. Most people learn from a bad outcome and don't do it again, but someone with a substance use disorder continues to do that action."

In the case of PSMU, someone might feel bad if they are unable to access social media for an extended period (withdrawal), or their use of social media might lead to losing a job, poor grades, or mental health issues.

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The ongoing war between the Trump administration and Harvard University has taken a new twist, with the government sending Harvard a letter that, amid what appears to be a stream-of-consciousness culture war rant, announces that the university will not be receiving any further research grants. The letter potentially suggests that Harvard could see funding restored by "complying with long-settled Federal Law," but earlier demands from the administration included conditions that went well beyond those required by law.

The letter, sent by Secretary of Education Linda McMahon, makes it somewhat difficult to tell exactly what the government wants, because most of the text is a borderline deranged rant written in florid MAGA-ese. You don't have to go beyond the first paragraph to get a sense that this is less a setting of funding conditions than an airing of grievances:

Instead of using these funds to advance the education of its students, Harvard is engaging in a systemic pattern of violating federal law. Where do many of these "students" come from, who are they, how do they get into Harvard, or even into our country—and why is there so much HATE? These are questions that must be answered, among many more, but the biggest question of all is, why will Harvard not give straightforward answers to the American public?

Does Harvard have to answer these questions to get funding restored? It's unclear.

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The first production satellites for Amazon's Kuiper broadband network launched earlier this week, but if you tuned in to the mission's official livestream, the truncated coverage had the feel of a spy satellite launch.

This changed with a video Amazon posted on social media Friday, giving space enthusiasts and prospective Kuiper customers their first look at the real satellites. The 40-second clip shows the Kuiper satellites separating from their launch vehicle in the blackness of space following liftoff Monday from Cape Canaveral Space Force Station, Florida.

Since Amazon unveiled Project Kuiper in 2019, officials at the retail giant have been shy about showing even the most basic imagery of their satellites. Images released by Amazon previously provided glimpses inside the company's satellite factory near Seattle, along with views of the shipping containers Amazon uses to transport spacecraft from Washington their launch base in Florida.

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Archaeologists recently unearthed a bone projectile point someone dropped on a cave floor between 80,000 and 70,000 years ago—which, based on its location, means that said someone must have been a Neanderthal.

The point (or in paleoarchaeologist Liubov V. Golovanova and colleagues’ super-technical archaeological terms, “a unique pointy bone artifact”) is the oldest bone tip from a hunting weapon ever found in Europe. It’s also evidence that Neanderthals figured out how to shape bone into smooth, aerodynamic projectiles on their own, without needing to copy those upstart Homo sapiens. Along with the bone tools, jewelry, and even rope that archaeologists have found at other Neanderthal sites, the projectile is one more clue pointing to the fact that Neanderthals were actually pretty sharp.

Getting to the point

Archaeologists found the bone point in Mezmaiskaya Cave, high in the Caucasus Mountains (Mezmaiskaya is also home to the remains of three Neanderthals who lived around 90,000 years ago; anthropologists sequenced samples of their DNA in earlier studies). Herbivore teeth from the same layer of sediment dated to around 70,000 years old, and the bone point’s position near the bottom of that layer probably makes it closer to 80,000 or 70,000 years old. That makes it the oldest bone projectile point ever found in Europe (so far).

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Sulo Roukka is this year's overall winner of the Dance Your PhD contest, plus the winner of the chemistry category.

It's time again to honor the winners of the annual Dance Your PhD contest, where eager young scientists attempt to convey the concepts of their doctoral theses through dance. This year's overall winner is the University of Helsinki's Sulo Roukka, who researches chemesthesis, specifically how people experience different sensory food compounds like capsaicin (hot) or menthol (cool).

As we've reported previously, the Dance Your PhD contest was established in 2008 by science journalist John Bohannon, who is now a data scientist at South Park Commons. Bohannon told Slate in 2011 that he came up with the idea while trying to figure out how to get a group of stressed-out PhD students, who were in the middle of defending their theses, to let off a little steam. So he put together a dance party at Austria's Institute of Molecular Biotechnology, including a contest for whichever candidate could best explain their thesis topics through interpretive dance.

The contest was such a hit that Bohannon started getting emails asking when the next one would be—and Dance Your PhD has continued ever since. It's now in its 17th year. There are four broad categories: physics, chemistry, biology, and social science, with a fairly liberal interpretation of what topics fall under each. All category winners receive $750. Roukka won the chemistry category and, as the overall champion, will receive an additional $2,750.

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A thousand years ago, the people living in Chaco Canyon were building massive structures of intricate masonry and locations as far away as Mexico. Within a century, however, the area would be largely abandoned, with little indication that the same culture was re-established elsewhere. If the people of Chaco Canyon migrated elsewhere, it's unclear where they ended up.

Around the same time that construction expanded in Chaco Canyon, far smaller pueblos began appearing in the northern Rio Grande Valley hundreds of kilometers away. These have remained occupied to the present day in New Mexico; although their populations shrank dramatically after European contact, their relationship to the Chaco culture has remained ambiguous. Until now, that is. People from one of these communities, Picuris Pueblo, worked with ancient DNA specialists to show that they are the closest relatives of the Chaco people yet discovered, confirming aspects of the pueblo's oral traditions.

A pueblo-driven study

The list of authors of the new paper describing this genetic connection includes members of the Pueblo government, including its present governor. That's because the study was initiated by the members of the Pueblo, who worked with archeologists to get in contact with DNA specialists at the Center for GeoGenetics at the University of Copenhagen. In a press conference, members of the Pueblo said they'd been aware of the power of DNA studies via their use in criminal cases and ancestry services. The leaders of Picuris Pueblo felt that it could help them understand their origin and the nature of some of their oral history, which linked them to the wider Pueblo-building peoples.

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When the Vietnam War finally ended on April 30, 1975, it left behind a landscape scarred with environmental damage. Vast stretches of coastal mangroves, once housing rich stocks of fish and birds, lay in ruins. Forests that had boasted hundreds of species were reduced to dried-out fragments, overgrown with invasive grasses.

The term “ecocide” had been coined in the late 1960s to describe the US military’s use of herbicides like Agent Orange and incendiary weapons like napalm to battle guerrilla forces that used jungles and marshes for cover.

Fifty years later, Vietnam’s degraded ecosystems and dioxin-contaminated soils and waters still reflect the long-term ecological consequences of the war. Efforts to restore these damaged landscapes and even to assess the long-term harm have been limited.

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As the trade war between China and the United States continues to escalate, Beijing is responding by turning to one of its favorite retaliation tactics: limiting the export of critical minerals used in many high-tech electronics, from fighter jets to wind turbines. While China’s mineral restrictions may sound scary, the reality is that they haven’t been very effective in the past and stand to become even less so if the US and other countries finally get their acts together.

It all started in July 2023, when the Chinese government announced it would restrict the export of gallium and germanium, two critical minerals that are mostly used in making solar panels and semiconductors. Over the following two years, China’s list of controlled products expanded to include antimony, graphite, and other materials. Earlier this month, the Chinese government escalated things even further, subjecting seven rare earth elements to a more comprehensive export licensing program that covers the whole world and is designed to further choke off American companies.

Rare earths are a subset of elements under the broader umbrella of critical minerals that China has long enjoyed monopoly control over. In the short term, companies that need these rare earths might be able to rely on existing stockpiles or even turn to recycled electronics to find them. But eventually, the US and other countries will be forced to either ramp up domestic mining or reduce their dependence on rare earths, both of which would make China’s policies sting less. “China has got one shot, and it knows it,” says Ian Lange, an associate professor of economics and business at the Colorado School of Mines.

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Is there anything more human than gathering in groups to share food and partake in a fermented beverage or two (or three, or....)? Researchers have caught wild chimpanzees on camera engaging in what appears to be similar activity: sharing fermented African breadfruit with measurable alcoholic content. According to a new paper published in the journal Current Biology, the observational data is the first evidence of the sharing of alcoholic foods among nonhuman great apes in the wild.

The fruit in question is seasonal and comes from Treculia africana trees common across the home environment of the wild chimps in Cantanhez National Park in Guinea-Bissau. Once mature, the fruits drop from the tree to the ground and slowly ripen from a hard, deep green exterior to a yellow, spongier texture. Because the chimps are unhabituated, the authors deployed camera traps at three separate locations to record their feeding and sharing behavior.

They recorded 10 instances of selective fruit sharing among 17 chimps, with the animals exhibiting a marked preference for riper fruit. Between April and July 2022, the authors measured the alcohol content of the fruit with a handy portable breathalyzer and found almost all of the fallen fruit (90 percent) contained some ethanol, with the ripest containing the highest levels—the equivalent of 0.61 percent ABV (alcohol by volume).

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On Wednesday, news broke that researchers had found the most compelling evidence yet of a "biosignature"—a chemical present at levels that are only consistent with life—on a distant exoplanet. It didn't take much time for some less-than-reliable news sources to go from there to talk of a planet that "could be 'teeming with life'" and the obvious follow-up, "Scientists reveal what aliens could REALLY look like on exoplanet K2-18b."

Even in the best of circumstances, however, talk of a biosignature is an invitation to scientists to think of alternative chemistries that could explain the chemistry without needing biological activity. And these are not the best of circumstances, as astronomers are pointing to earlier papers that give a range of reasons to be skeptical of the new results; in fact, an astronomer named Chris Glein emailed me to alert me of potential issues the day before the news broke.

To help you understand the controversy, we're going to look at the data that is being presented as evidence of a biosignature and then go through all the reasons that confirming a biosignature is so difficult.

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Kevin Peterson is a "nose" for his own perfume company, Sfumato Fragrances, by day. By night, Sfumato's retail store in Detroit transforms into Peterson's craft cocktail bar, Castalia, where he is chief mixologist and designs drinks that pair with carefully selected aromas. He's also the author of Cocktail Theory: A Sensory Approach to Transcendent Drinks, which grew out of his many (many!) mixology experiments and popular YouTube series, Objective Proof: The Science of Cocktails.

It's fair to say that Peterson has had an unusual career trajectory. He worked as a line cook and an auto mechanic, and he worked on the production line of a butter factory, among other gigs, before attending culinary school in hopes of becoming a chef. However, he soon realized it wasn't really what he wanted out of life and went to college, earning an undergraduate degree in physics from Carleton College and a PhD in mechanical engineering from the University of Michigan.

After 10 years as an engineer, he switched focus again and became more serious about his side hobby, perfumery. "Not being in kitchens anymore, I thought—this is a way to keep that little flavor part of my brain engaged," Peterson told Ars. "I was doing problem sets all day. It was my escape to the sensory realm. 'OK, my brain is melting—I need a completely different thing to do. Let me go smell smells, escape to my little scent desk.'" He and his wife, Jane Larson, founded Sfumato, which led to opening Castalia, and Peterson finally found his true calling.

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