marketrent

marketrent OP t1_jdjtspn wrote

Findings in title quoted from the linked paper^1 and a summary^2 from the University of Tokyo.

From the linked paper:^1

>We do not need living organisms, but the existence of life in exoplanets can be probed by remains of microbes, microfossils, minerals produced by biological activities (biominerals), or any other signatures of past biological activities (e.g. concentration of biological molecules or isotopic ratios) (Cavalazzi and Westall 2018).

From the summary:^2

>“I propose we study well-preserved grains ejected from other worlds for potential signs of life,” said Totani [of the University of Tokyo’s Department of Astronomy].

>“The search for life outside our solar system typically means a search for signs of communication, which would indicate intelligent life but precludes any pre-technological life.

>“Or the search is for atmospheric signatures that might hint at life, but without direct confirmation there could always be an explanation that does not require life.

>“However, if there are signs of life in dust grains, not only could we be certain, but we could also find out soon.”

> 

>The basic idea is that large asteroid strikes can eject ground material into space. There is a chance that recently deceased or even fossilized microorganisms could be contained in some rocky material in this ejecta.

>This material will vary in size greatly, with different-sized pieces behaving differently once in space.

>Some larger pieces might fall back down or enter permanent orbits around a local planet or star. And some much smaller pieces might be too small to contain any verifiable signs of life.

>But grains in the region of 1 micrometer (one-thousandth of a millimeter) could not only host a specimen of a single-celled organism, but they could also potentially escape their host solar system altogether, and under the right circumstances, maybe even venture to ours.

>There may be such grains already on Earth, and in plentiful amounts, preserved in places such as the Antarctic ice, or under the seafloor.

^1 Tomonori Totani (2023) Solid grains ejected from terrestrial exoplanets as a probe of the abundance of life in the Milky Way. International Journal of Astrobiology, https://doi.org/10.1017/S147355042300006X

^2 Searching for life with space dust, 22 Mar. 2023, https://www.u-tokyo.ac.jp/focus/en/press/z0508_00283.html

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marketrent OP t1_jdilaqd wrote

Excerpt from the linked content^1 by Rani Gran:

>NASA's OSIRIS-REx spacecraft is cruising back to Earth with a sample it collected from the rocky surface of asteroid Bennu.

>When its sample capsule parachutes down into the Utah desert on Sept. 24, OSIRIS-REx will become the United States’ first-ever mission to return an asteroid sample to Earth.

>After seven years in space, including a nail-biting touchdown on Bennu to gather dust and rocks, this intrepid mission is about to face one of its biggest challenges yet: deliver the asteroid sample to Earth while protecting it from heat, vibrations, and earthly contaminants.

>“Once the sample capsule touches down, our team will be racing against the clock to recover it and get it to the safety of a temporary clean room,” said Mike Moreau, deputy project manager at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

>So, over the next six months, the OSIRIS-REx team will practice and refine the procedures required to recover the sample in Utah and transport it to a new lab built for the material at NASA’s Johnson Space Center in Houston.

>There, scientists will unpack the sample, distribute up to a quarter of it to the OSIRIS-REx science team around the world for analysis, and curate the rest for other scientists to study, now and in future generations.

^1 NASA prepares for historic asteroid sample delivery on Sept. 24, Rani Gran for NASA, 24 Mar. 2023, https://www.nasa.gov/feature/goddard/2023/nasa-prepares-for-osiris-rex-historic-asteroid-sample-delivery-sept-24-2023

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marketrent OP t1_jdfb4ke wrote

Excerpt from the linked summary^1 by Kendra Leon, about a Current Biology paper:^2

>A daisy living in Namaqualand, a desert environment in northern South Africa where it rains only during the winter, has a few weeks to bloom, pollinate, and set seeds before the area becomes too dry for it to live.

>All the while, it must compete with other flowers to attract pollinator flies.

>According to a study by Beverley Glover, a professor at the University of Cambridge’s Department of Plant Sciences and the director of the University’s Botanic Garden, and her team, the daisy known as *Gorteria * combines at least three preexisting genes to "create" lifelike female flies.

>“The thing that’s clever here is that these flowers have 12 to 14 petals, and you only get the spots on two to four of them that look totally random in position. That’s what the fly is doing. They’re looking at it and going, ‘Oh, that’s random. That’s not part of the plant. It must be a lady fly,’” Glover said in a phone interview.

>The male fly then lands on top of the "lady fly" and wiggles around in a vain attempt to mate. Eventually he gives up and flies away, but all the wiggling gave the daisy what it needs to survive — pollen.

> 

>Glover and her team found the gene that moves iron in the daisy changes some of its normally reddish-purple petals to a “more fly-like blue-green.”

>Meanwhile, the gene that grows hairs on the daisy's root causes the the petal hairs to expand, giving its fake female flies texture.

>To further add realism to its fake female flies and draw in unwitting and mating-focused male flies, Glover said the daisy has its fake flies appear seemingly at random — thereby avoiding looking like a patterned, spotted flower.

>She also noted the daisy creates the flies in a spiral pattern which she compared to a clock, with a fake fly petal appearing at 12 o’clock, then another at 4 o’clock and so on to give it the “appearance of being random but it’s not random at all.”

^1 Kendra Leon for Courthouse News, 23 Mar. 2023, https://www.courthousenews.com/daisy-found-to-create-fake-female-flies-to-lure-pollen-bearing-males/

^2 Roman Kellenberger et al. Multiple gene co-options underlie the rapid evolution of sexually deceptive flowers in Gorteria diffusa. Current biology (23 Mar. 2023) https://doi.org/10.1016/j.cub.2023.03.003

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marketrent OP t1_jde7mk1 wrote

Excerpt from the linked summary^1 of a paper:^2

>"We have shed new light on the molecular mechanisms that allow beetles to absorb water rectally. Insects are particularly sensitive to changes in their water balance.

>"As such, this knowledge can be used to develop more targeted methods to combat beetle species which destroy our food production, without killing other animals or harming humans and nature," says Associate Professor Kenneth Veland Halberg of the Department of Biology, who led the research.

>The researchers studied the internal organs of red flour beetles to learn more about their ability to absorb water through the rectum.

>Red flour beetles are used as so-called model organisms, which means that they are offer tools that make them easy to work with and that their biology is similar to that found in other beetles.

> 

>Here, the researchers identified a gene that is expressed sixty times more in the beetle's rectum compared to the rest of the animal, which is higher than any other gene they found.

>This led them to a unique group of cells known as leptophragmata cells. Upon closer inspection, they could see that these cells play a crucial role when the beetle absorbs water through its rear end.

>"Leptophragmata cells are tiny cells situated like windows between the beetle's kidneys and the insect circulatory system, or blood.

>"As the beetle's kidneys encircle its hindgut, the leptophragmata cells function by pumping salts into the kidneys so that they are able to harvest water from moist air through their rectums and from here into their bodies.

>"The gene we have discovered is essential to this process, which is new knowledge for us," explains Halberg.

^1 University of Copenhagen, 22 Mar. 2023. https://news.ku.dk/all_news/2023/03/researchers-get-to-the-bottom-of-how-beetles-use-their-butts-to-stay-hydrated/

^2 Muhammad T. Naseem et al. (2023) NHA1 is a cation/proton antiporter essential for the water-conserving functions of the rectal complex in Tribolium castaneum. Proceedings of the National Academy of Sciences 120 (13) e2217084120. https://doi.org/10.1073/pnas.2217084120

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marketrent OP t1_jda9nrk wrote

Excerpt from the linked content^1 by Amanda Silberling:

>At a company that helps people find jobs, 2,200 employees will now have to embark on a job search of their own. Indeed laid off 15% of employees today, CEO Chris Hyams announced in an all-hands meeting.

>In a blog post, Hyams elaborated on the decision by explaining that the job market is expected to continue to cool down. Indeed makes its money by allowing companies to sponsor job listings, which shows the listing to more job seekers.

>But Hyams said that as of last quarter, sponsored job volumes were down 33% year over year, and total job openings were down 3.5%.

>The CEO will take a 25% cut in base pay himself.

>Employees were emailed about their job status within an hour of the announcement — the subject lines of these emails either read “Your Position Has Been Impacted” or “Your Position Has Not Been Impacted.”

>Employees in the U.K., Ireland, the Netherlands and Japan may still be in limbo, due to local regulations.

^1 Amanda Silberling for TechCrunch/Apollo Global Management, 22 Mar. 2023, https://techcrunch.com/2023/03/22/job-listing-platform-indeed-lays-off-2200-employees/

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marketrent OP t1_jd881n1 wrote

>creepystepdad72

>The memo IS NOT saying they hired 3x the allocated positions; rather, it's saying the additional postings have caused an increase in instances of mistakes being made (e.g. backfill hired for a person who ended up staying on, etc.)

According to the title of the linked content:^1

>Leaked document shows Amazon's flawed job-posting process led to 'over-hiring,' with one team listing 3 times more openings than approved for

According to the text of the linked content:^1

>But for Amazon, most job posts were being actively filled, even if they weren't approved for, in part due to the lack of internal governance, the former recruiting manager said.

Emphases added.

^1 Eugene Kim for Insider/Axel Springer, 21 Mar. 2023, https://www.businessinsider.com/amazon-flawed-job-listing-process-over-hiring-layoffs-2023-3

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marketrent OP t1_jd86mmk wrote

Excerpt from the linked content^1,2 by Greg Allen:

>The mosquito — known by its scientific name of Culex lactator — is typically found in Central and South America. Researchers with the University of Florida Medical Entomology Laboratory first discovered it in a rural area near Miami in 2018.

>It's since spread to other counties in Southwest Florida.

>It's not known how the new mosquito was introduced into Florida. Scientists say climate change appears to be a factor that's making the state and other parts of the U.S. welcoming to non-native mosquitoes that can carry diseases.

>Mosquito biologist Lawrence Reeves is the lead author of a report on the newly-discovered species, published Wednesday in the Journal of Medical Entomology.

>He says, "There are about 90 mosquito species living in Florida, and that list is growing as new mosquito species are introduced to the state from elsewhere in the world."

>Reeves says little is known about Culex lactator, but it bears further study. It's a member of a group of mosquitoes known to carry the West Nile and St. Louis Encephalitis viruses.

>The U.S. faces public health challenges related to diseases like West Nile, dengue, and chikungunya, all of which are spread by non-native mosquitoes that have become established here.

>Reeves says, "We need to be vigilant for introductions of new mosquito species because each introduction comes with the possibility that the introduced species will facilitate the transmission of a mosquito-transmitted disease."

^1 A new tropical mosquito has come to Florida, 22 Mar. 2023, https://www.npr.org/2023/03/22/1164937874/uh-oh-a-new-tropical-mosquito-has-come-to-florida-the-buzz-its-creating-isnt-goo

^2 Lawrence E Reeves, Kristin E Sloyer, Kara Tyler-Julian, Rebecca Heinig, Atom Rosales, Candelaria Domingo, Nathan D Burkett-Cadena. Culex (Phenacomyia) lactator (Diptera: Culicidae) in southern Florida, USA: a new subgenus and species country record. Journal of Medical Entomology, 2023; tjad023. https://doi.org/10.1093/jme/tjad023

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marketrent OP t1_jd7422n wrote

Excerpt from the linked summary:^1

>Trilobites, prehistoric sea creatures, had so-called median eyes, single eyes on their foreheads, in addition to their compound eyes, research conducted by Dr Brigitte Schoenemann at the University of Cologne’s Institute of Zoology and Professor Dr Euan Clarkson at the University of Edinburgh has now found out.

>Such single eyes are found in all arthropods and also in many relatives of the extinct trilobites. They are usually small cup eyes (ocelli), sometimes even equipped with lenses, and not unlike human eyes.

>Schoenemann and Clarkson examined a specimen of the trilobite Aulacopleura koninckii in which part of the head had been scraped off.

>They found three almost identically shaped dark, inconspicuous and tiny oval spots of the same size at the front of the head. These three structures are parallel to each other and fan out slightly on the underside.

>All three spots are characterized by a smooth, clear outline and a uniform, dark brownish colour.

> 

>In the trilobite Cyclopyge sibilla, which lived in the free ocean, the researchers also found three cup-shaped median eyes on the so-called glabella, the region in the middle of the forehead between the large compound eyes, which even apparently had a lens not unsimilar to human eyes, and were thus clearly more differentiated and probably much more efficient than those of the bottom-dwelling trilobite Aulacopleura.

>In their article, the researchers also consider why the median eyes of trilobites have escaped detection until now: “These eyes are present in trilobites at the larval stage, but lie beneath what is probably a thin, transparent carapace (cuticle), which becomes opaque during fossilisation.

>Both explain why they have remained undiscovered until now,” she added. Thus, the researchers have solved the mystery of missing middle eyes in trilobites.

^1 New eyes discovered in trilobites, 17 Mar. 2023, https://portal.uni-koeln.de/en/universitaet/aktuell/press-releases/single-news/new-eyes-discovered-in-trilobites

^2 Schoenemann, B., Clarkson, E.N.K. The median eyes of trilobites. Scientific Reports 13, 3917 (2023). https://doi.org/10.1038/s41598-023-31089-7

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marketrent OP t1_jd69ims wrote

Excerpt from the linked content^1 by Eugene Kim:

>Amazon had little oversight over its job opening process until last year, allowing managers to recruit far more, and ultimately hire more employees, than they were approved to bring on, Insider has learned.

>For example, the utility computing team at Amazon Web Service had 24,988 hiring job posts opened in 2022, when only 7,798 positions were approved for, according to an internal document obtained by Insider.

>That means the utility computing team had over 3-times more job postings than the headcount target at the time.

>The document points to Amazon's lack of standardization and governance for the gap between the job postings and open headcount.

> 

>The result was "a process prone to inconsistency, error, and potential mis-use," including "over-hiring," the document said.

>"This enabled over-hiring in certain cost centers and contributed to span of control and level ratio defects," the internal document said.

>Levels is tech-industry speak for an employee's seniority level, which determines their pay. In theory, if multiple job postings for the same job called for different seniority, a unit could wind up with more over-qualified, or under-qualified, people in the unit than planning budgets assumed.

>"Span of control" is industry jargon for the number of direct reports under each manager, according to Gartner.

^1 Eugene Kim for Insider/Axel Springer, 21 Mar. 2023, https://www.businessinsider.com/amazon-flawed-job-listing-process-over-hiring-layoffs-2023-3

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marketrent OP t1_jd31pi3 wrote

Excerpt from the linked summary^1 by Dyani Lewis, about research^2 by Hongru Wang et al.:

>The Tibetan Plateau extends from the northern edge of the Himalayas across 2.5 million square kilometres. It is a high-altitude, dry and cold region.

>Despite its inhospitable environment, humans have been present on the plateau since prehistoric times. Denisovans, extinct hominins that interbred with both Neanderthals and the ancestors of modern humans, lived on the northeastern edge of the plateau 160,000 years ago.

>Stone tools made 30,000–40,000 years ago are further signs of an early human presence in the region.

>But when people established a permanent presence on the plateau — and where they came from — has been a matter of debate, says Qiaomei Fu, an evolutionary geneticist at the Chinese Academy of Sciences in Beijing, who led the study.

> 

>Fu and her team sequenced ancient genomes from the remains of 89 individuals, dated to 5,100–100 years ago, unearthed from 29 archaeological sites.

>Their study confirms that permanent occupation of the region pre-dates historical records.

>It also paints a complex picture of where early Tibetans migrated from, and how their interactions in the region and with their lowland neighbours shaped their heritage.

>Analysis of the genomes reveals that the ancient occupants of the Tibetan Plateau have strong genetic links to the Tibetan, Sherpa and Qiang ethnic groups that live on or near the plateau today.

>Comparisons of the oldest genomes with ancient and living people across Asia suggest that the ancestors of modern Tibetans arrived on the plateau from the east.

>By contrast, India and the rest of the Asian subcontinent were populated by immigrants from eastern Eurasia and central Asia.

^1 Dyani Lewis, Nature, 17 Mar. 2023, https://www.nature.com/articles/d41586-023-00742-6

^2 Hongru Wang et al. Human genetic history on the Tibetan Plateau in the past 5100 years. Science Advances 9, eadd5582 (2023) https://doi.org/10.1126/sciadv.add5582

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