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10 billion year, 50,000 light-year journey to black hole

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10 billion year, 50,000 light-year journey to black hole


A star near the supermassive black hole at the center of the Milky Way Galaxy originated outside of the Galaxy according to a new study. This is the first time a star of extragalactic origin has been found in the vicinity of the super massive black hole.

Many stars are observed near the supermassive black hole known as Sagittarius A* at the center of our Galaxy. But the black hole’s intense gravity makes the surrounding environment too harsh for stars to form near the black hole. All the observed stars must have formed somewhere else and migrated towards the black hole. This raises the question, where did the stars form.

Research by an international team led by Shogo Nishiyama at Miyagi University of Education indicates the some of the stars may have come from farther away than previously thought, from completely outside of the Milky Way. The team used the Subaru Telescope over the course of eight years to observe the star S0-6 located only 0.04 light-years away from Sagittarius A*. They determined that S0-6 is about 10 billion years old and has a chemical composition similar to stars found in small galaxies outside the Milky Way, such as the Small Magellanic Cloud and the Sagittarius dwarf galaxy.

The most likely theory to explain the composition of S0-6 is that it was born in a now extinct small galaxy orbiting the Milky Way that was absorbed. This is the first observational evidence suggesting that some of the stars in the vicinity of Sagittaius A* formed outside of the Galaxy. Over its 10 billion year life, S0-6 must have travelled more than 50,000 light-years from outside of the Milky Way to reach the vicinity of Sagittarius A*. Almost certainly S0-6 traveled much more than 50,000 light-years, slowly spiraling down to the center rather than making a straight shot.

There are still many questions according to Nishiyama, “Did S0-6 really originate outside the Milky Way galaxy? Does it have any companions, or did it travel alone? With further investigation, we hope to unravel the mysteries of stars near the supermassive black hole.”



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The unintended consequences of success against malaria

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For decades, insecticide-treated bed nets and indoor insecticide spraying regimens have been important — and widely successful — treatments against mosquitoes that transmit malaria, a dangerous global disease. Yet these treatments also — for a time — suppressed undesirable household insects like bed bugs, cockroaches and flies.

Now, a new North Carolina State University study reviewing the academic literature on indoor pest control shows that as the household insects developed resistance to the insecticides targeting mosquitoes, the return of these bed bugs, cockroaches and flies into homes has led to community distrust and often abandonment of these treatments — and to rising rates of malaria.

In short, the bed nets and insecticide treatments that were so effective in preventing mosquito bites — and therefore malaria — are increasingly viewed as the causes of household pest resurgence.

“These insecticide-treated bed nets were not intended to kill household pests like bed bugs, but they were really good at it,” said Chris Hayes, an NC State Ph.D. student and co-corresponding author of a paper describing the work. “It’s what people really liked, but the insecticides are not working as effectively on household pests anymore.”

“Non-target effects are usually harmful, but in this case they were beneficial,” said Coby Schal, Blanton J. Whitmire Distinguished Professor of Entomology at NC State and co-corresponding author of the paper.

“The value to people wasn’t necessarily in reducing malaria, but was in killing other pests,” Hayes added. “There’s probably a link between use of these nets and widespread insecticide resistance in these house pests, at least in Africa.”

The researchers add that other factors — famine, war, the rural/city divide, and population displacement, for example — also could contribute to rising rates of malaria.

To produce the review, Hayes combed through the academic literature to find research on indoor pests like bed bugs, cockroaches and fleas, as well as papers on malaria, bed nets, pesticides and indoor pest control. The search yielded more than 1,200 papers, which, after an exhaustive review process, was whittled down to a final count of 28 peer-reviewed papers fulfilling the necessary criteria.

One paper — a 2022 survey of 1,000 households in Botswana — found that while 58% were most concerned with mosquitoes in homes, more than 40% were most concerned with cockroaches and flies.

Hayes said a recent paper — published after this NC State review was concluded — showed that people blamed the presence of bed bugs on bed nets.

“There is some evidence that people stop using bed nets when they don’t control pests,” Hayes said.

The researchers say that all hope is not lost, though.

“There are, ideally, two routes,” Schal said. “One would be a two-pronged approach with both mosquito treatment and a separate urban pest management treatment that targets pests. The other would be the discovery of new malaria-control tools that also target these household pests at the same time. For example, the bottom portion of a bed net could be a different chemistry that targets cockroaches and bed bugs.

“If you offer something in bed nets that suppresses pests, you might reduce the vilification of bed nets.”

The study appears in Proceedings of the Royal Society B. The review was supported in part by the Blanton J. Whitmire Endowment at NC State, and grants from the U.S. Department of Housing and Urban Development Healthy Homes program (NCHHU0053-19), the Department of the Army, U.S. Army Contracting Command, Aberdeen Proving Ground, Natick Contracting Division, Ft. Detrick, Maryland (W911QY1910011), and the Triangle Center for Evolutionary Medicine (257367).



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Taco-shaped arthropod fossils gives new insights into the history of the first mandibulates

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A new study, led by palaeontologists at the Royal Ontario Museum (ROM) is helping resolve the evolution and ecology of Odaraia, a taco-shaped marine animal that lived during the Cambrian period. Fossils collected by ROM reveal Odaraia had mandibles. Palaeontologists are finally able to place it as belonging to the mandibulates, ending its long enigmatic classification among the arthropods since it was first discovered in the Burgess Shale over 100 years ago and revealing more about early evolution and diversification. The study The Cambrian Odaraia alata and the colonization of nektonic suspension-feeding niches by early mandibulates was published in the journal Proceedings B.

The study authors were able to identify a pair of large appendages with grasping jagged edges near its mouth, clearly indicative of mandibles which are one of the key and distinctive features of the mandibulate group of animals. This suggests that Odaraia was one of the earliest known members of this group. The researchers made another stunning discovery, a detailed analysis of its more than 30 pairs of legs, found an intricate system of small and large spines. According to the authors, these spines could intertwine, capturing smaller prey as though a fishing net, suggesting how some of these first mandibulates left the sea floor and explored the water column, setting the seeds for their future ecological success.

“The head shield of Odaraia envelops practically half of its body including its legs, almost as if it were encased in a tube. Previous researchers had suggested this shape would have allowed Odaraia to gather its prey, but the capturing mechanism had eluded us, until now,” says Alejandro Izquierdo-López, lead author, who was based at ROM during this work as a PhD student at the University of Toronto. “Odaraia had been beautifully described in the 1980s, but given the limited number of fossils at that time and its bizarre shape, two important questions had remained unanswered: is it really a mandibulate? And what was it feeding on?”

At almost 20 cm in size, the authors explain that early mandibulates like Odaraia were part of a community of large animals that could have been able to migrate from the marine bottom-dwelling ecosystems characteristic of the Cambrian period to the upper layers of the water column. These types of communities could have enriched the water column and facilitated a transition towards more complex ecosystems.

Cambrian fossils record the major divergence of animal groups originating over 500 million years ago. This period saw the evolution of innumerable innovations, such as eyes, legs or shells, and the first diversification of many animal groups, including the mandibulates, one of the major groups of arthropods (animals with jointed limbs).

Mandibulates are an example of evolutionary success, representing over half of all current species on Earth. Today, mandibulates are everywhere: from sea-dwelling crabs to centipedes lurking in the undergrowth or bees flying across meadows, but their beginnings were more humble. During the Cambrian period, the first mandibulates were marine animals, most bearing distinct head shields or carapaces.

“The Burgess Shale has been a treasure trove of paleontological information,” says Jean-Bernard Caron, Richard Ivey Curator at the Royal Ontario Museum, and co-author of the study. “Thanks to the work we have been doing at the ROM on amazing fossil animals such as Tokummia and Waptia, we already know a substantial amount about the early evolution of mandibulates. However, some other species had remained quite enigmatic, like Odaraia.

The Royal Ontario Museum holds the largest collections of Cambrian fossils from the world-renowned Burgess Shale of British Columbia. Burgess Shale fossils are exceptional, as they preserve structures, animals and ecosystems that under normal conditions would have decayed and completely disappeared from the fossil record. Mandibulates, though, are generally rare in the fossil record. Most fossils preserve only the hard parts of animals, such as skeletons or the mineralized cuticles of the well-known trilobites, structures that mandibulates lack.

For over forty years Odaraia has been one of the most iconic animals of the Burgess Shale, with its distinctive taco-shaped carapace, its large head and eyes, and a tail that resembles a submarine’s keel. The public can view specimens of Odaraia on display at the Willner Madge Gallery, Dawn of Life at the Royal Ontario Museum.



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Drawing water from dry air

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Earth’s atmosphere holds an ocean of water, enough liquid to fill Utah’s Great Salt Lake 800 times.

Extracting some of that moisture is seen as a potential way to provide clean drinking water to billions of people globally who face chronic shortages.

Existing technologies for atmospheric water harvesting (AWH) are saddled with numerous downsides associated with size, cost and efficiency. But new research from University of Utah engineering researchers has yielded insights that could improve efficiencies and bring the world one step closer to tapping the air as a culinary water source in arid places.

The study unveils the first-of-its-kind compact rapid cycling fuel-fired AWH device. This two-step prototype relies on adsorbent materials that draw water molecules out of non-humid air, then applies heat to release those molecules into liquid form, according to Sameer Rao, senior author of the study published Monday and an assistant professor of mechanical engineering.

“Hygroscopic materials intrinsically have affinity to water. They soak up water wherever you go. One of the best examples is the stuff inside diapers,” said Rao, who happens to be the father of an infant son. “We work with a specific type of hygroscopic material called a metal organic framework.”

Rao likened metal organic frameworks to Lego blocks, which can be rearranged to build all sorts of structures. It this case they are arranged to create a molecule ideal for gas separation.

“They can make it specific to adsorb water vapor from the air and nothing else. They’re really selective,” Rao said. Developed with graduate student Nathan Ortiz, the study’s lead author, this prototype uses aluminum fumarate that was fashioned into panels that collect the water as air is drawn through.

“The water molecules themselves get trapped on the surfaces of our material, and that’s a reversible process. And so instead of becoming ingrained into the material itself, it sits on the walls,” Ortiz said. “What’s special about these absorbent materials is they have just an immense amount of internal surface area. There’s so many sites for water molecules to get stuck.”

Just a gram of this material holds as much surface area as two football fields, according to Rao. So just a little material can capture a lot of water.

“All of this surface area is at the molecular scale,” Rao said. “And that’s awesome for us because we want to trap water vapor onto that surface area within the pores of this material.”

Funding for the research came from the DEVCOM Soldier Center, a program run by the Department of Defense to facilitate technology transfer that supports Army modernization. The Army’s interest in the project stems from the need to keep soldiers hydrated while operating in remote areas with few water sources.

“We specifically looked at this for defense applications so that soldiers have a small compact water generation unit and don’t need to lug around a large canteen filled with water,” Rao said. “This would literally produce water on demand.”

Rao and Ortiz have filed for a preliminary patent based on the technology, which addresses non-military needs as well.

“As we were designing the system, I think we also had perspective of the broader water problem. It’s not just a defense issue, it’s very much a civilian issue,” Rao said. “We think in terms water consumption of a household for drinking water per day. That’s about 15 to 20 liters per day.”

In this proof of concept, the prototype achieved its target of producing 5 liters of water per day per kilogram of adsorbent material. In a matter of three days in the field, this devise would outperform packing water, according to Ortiz.

In the device’s second step, the water is precipitated into liquid by applying heat using a standard-issue Army camping stove. This works because of the exothermic nature of its water collecting process.

“As it collects water, it’s releasing little bits of heat. And then to reverse that, we add heat,” Ortiz said. “We just put a flame right under here, anything to get this temperature up. And then as we increase the temperature, we rapidly release the water molecules. Once we have a really humid airstream, that makes condensation at ambient temperature much easier.”

Nascent technologies abound for atmospheric water harvesting, which is more easily accomplished when the air is humid, but none has resulted in equipment that can be put to practical use in arid environments. Ortiz believes his device can be the first, mainly because it is powered with energy-dense fuel like the white gasoline used in camping stoves.

The team decided against using photovoltaics.

“If you’re reliant on solar panels, you’re limited to daytime operation or you need batteries, which is just more weight. You keep stacking challenges. It just takes up so much space,” Ortiz said. “This technology is superior in arid conditions, while refrigeration is best in high humidity.”



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