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How binary stars’ planets are born

A new mathematical simulation shows how gas and dust could swirl into planets in dual-star systems

Margaux Lopez

Astronomy

Vera C. Rubin Observatory

Want to make a new planet? All you need is a newborn star and a metric boatload of gas and dust particles. As they orbit the young star, these tiny bits of ice and dust collide, eventually growing up into full-blown planets. 

Seems simple enough. But what about making a planet with two suns? Stars are generally much bigger than planets, and throwing a second one into the mix — as in a binary system — speeds up how fast the pre-planet space dust swirls around thanks to increased gravitational forces. At those speeds, collisions mean destruction and it’s hard to build a planet. But scientists have detected exoplanets orbiting around binary star systems. So how did they get there?

A new mathematical model solves this mystery by simulating the planet formation process in a specific type of binary star system, where the smaller star orbits around the larger star about once a century. The researchers found that, as long as the bits of dust and ice swirl around the main star in a roughly circular orbit, any drag effects from stellar gas become very large in certain parts of the disc. This drag slows down the dust particles to more reasonable, less explosion-y speeds so that they can actually stick together instead of destroying each other. The leading particles in a group are slowed more than the ones behind it, allowing the trailing particles to catch up and join the expanding clump. It’s like a cycling road race. Cyclists tend to race in packs because wind drag is reduced behind a teammate. Once larger boulders about 10 kilometer in diameter are formed, they can survive high-speed collisions and are able to grow normally up to planet sizes.

While this particular kind of binary star system is now better understood, the next mystery for the new model to tackle is the formation of “Tatooine”-style planets, which orbit both stars in a binary system instead of just one. NASA’s Kepler Space Telescope has already found some of these deep in space, but we still don’t quite understand how they’re made.

A newly discovered cryosphere-dwelling yeast stays alive by making ethanol

Rhodotorula frigidialcoholis was isolated from 150,000-year-old permafrost in the McMurdo Dry Valleys of Antarctica

Mitra Kashani

Microbial Ecology

Centers for Disease Control and Prevention

El sur de Inglaterra alberga a una pequeña, pero prospera población de walabíes de cuello rojo

Los walabíes fueron introducidos al país al principio del siglo XX

Maria Gatta

Ecology and Conservation Biology

University of the Witwatersrand, Johannesburg

Walabíes: son muy monos, relativamente pequeños, y para los europeos, tienen una apariencia inédita. Esto es lo que llevó a la introducción del walabí de cuello rojo, una especie australiana, a principios del siglo XX a países como Inglaterra, Irlanda, y Francia. En aquellos tiempos, los walabíes se mantenían en zoos y colecciones privadas. Algunos escaparon, sobre todo durante la segunda guerra mundial, cuando la gente tenía cosas más importantes por las que preocuparse por mantener vallas.

Hoy en día, hay muy poca información disponible sobre que les pasó a aquellos walabíes introducidos. Dos científicos, Holly English y Anthony Caravaggi, decidieron investigar qué pasó con aquellos animales. Recogieron información sobre avistamientos de walabíes en los registros oficiales, las redes sociales, y los periódicos. Gracias a lo monos e inusuales que son, los avistamientos suelen ser mencionados en los periódicos locales.

En su artículo reciente publicado en la revista científica Ecologia y Evolución, los investigadores encontraron pequeñas poblaciones de walabíes viviendo a lo largo del sur de Inglaterra. Aunque alguno de estos animales es probablemente un fugitivo moderno de una colección privada o un zoo, es improbable que tales escapadas sean el origen de todos los avistamientos de la región. Por ello, los investigadores creen que las poblaciones del sur de Inglaterra se están reproduciendo en libertad.

Así que, si alguna vez estas en el sur de Inglaterra y crees que has visto a un walabí, ¡no te sorprendas demasiado!

Research demonstrates speech-in-noise training helps children with auditory processing disorder

Children with APD have difficulty perceiving speech when there is background noise and may have trouble on cognitive tests

Stephanie Santo

Psychology

Deep sea bacteria use selfishness to their advantage

Some bathypelagic bacteria have found a way to maximize their energy intake by taking food into their cells before breaking it down

Sarah Brown

Marine Science

University of North Carolina - Chapel Hill

The screen you are reading this on is probably emitting volatile organic compounds

A new study demonstrates that, in addition to a variety of other household products, LCD screens also emit these compounds

Kay McCallum

Atmospheric Chemistry

McMaster University

We spend a lot of time indoors - so it’s important that we know what’s in indoor air. Indoor chemists are especially concerned with volatile organic compounds (VOCs, a class of molecules that includes benzene, formaldehyde, and more), which can be harmful to human health and are highly reactive.

VOCs are released into indoor air from a number of sources – plants, wall paint, cooking and cleaning – and, as a recent study by a pair of researchers at the University of Toronto shows, from LCS screens like those in your phone, TV, and laptop.

To measure how LCD screens affect air quality, the researchers collected data on what types of compounds were contained in two types of samples: one of regular indoor air, and one collected near the surface of on an LCD screen like a new TV or an old laptop. They identified the chemical signatures of those compounds using a technique called proton-transfer reaction mass spectrometry. They then cross-referenced these signatures against lists of known liquid crystal monomers (the “building blocks” of LCD screens) and other compounds used in LCD screen manufacturing.

They found over 30 VOCs and 10 L liquid crystal monomers were heavily emitted into the air exposed to the screen, including extremely reactive species like isoprene and acetic acid. This finding indicates that LCD screens are an important source of VOCs in indoor environments, and that our screen-time may be exposing us to more than just new things on the internet.

Getting vaccinated against COVID-19 improves mental health

People who received the COVID-19 vaccine experienced less depression and anxiety compared to unvaccinated individuals

Danielle Llaneza

Health and Medicine

Hunter College and MD Anderson Cancer Center

Don’t bank those seeds — some oaks can be “cryopreserved”

Acorns can’t be frozen, but tips of oak tree shoots can

Christina Del Greco

Genetics and Genomics

University of Michigan

Male and female mice form memories of fearful events differently

A drug that blocks memory forming in male mice has a different effect in females

Rita Ponce

Evolutionary Biology

Polytechnic Institute of Setúbal

Psilocybin reduced depression symptoms as much as a leading antidepressant

New research compared the “magic mushrooms” component to Lexapro

Soren Emerson

Neuroscience

Vanderbilt University

Cocaine use slices and dices RNA in mouse brain cells

The analysis of epigenetic changes caused by cocaine use adds to the evidence that substance use disorders are rooted in biology

Anna Rogers

Molecular Biology

UC Berkeley

Your gut bacteria may be hoarding your medication

Researchers have observed this effect in petri dishes and nematodes

Madeline Barron

Microbiology

University of Michigan

Meet the springhare: the first glow-in-the-dark African mammal known to science

Researchers discovered the springhare’s fluorescent abilities entirely by accident

Shakira Browne

Zoology

University College Dublin

Fluorescence is caused by an animal absorbing light and bouncing it back out again, and in nature, it’s not a new thing. Fluorescence occurs across only a handful of mammals but they span three different continents and inhabit entirely different ecosystems. The platypus is one such animal, whose glow-in-the-dark abilities were only discovered in 2020. 

But, a discovery earlier this year by Northland College researchers that springhares fluoresce is special: it is the first documented case of biofluorescence in an Afro-Eurasian placental mammal. The study purports that perhaps fluorescence in mammals is not as rare as once previously thought. 

The researchers entered Chicago’s Field Museum of Natural History armed with a flashlight, with the goal of examining the fluorescent abilities of flying squirrels. Along the way, they accidentally discovered that springhares also glow. One specimen they examined was collected in 1905, and continued to glow in the dark for over 100 years.

The researchers subsequently tested live springhares (this time, in the dead of night—springhares are nocturnal) and found they could also fluoresce, predictably stronger than in the dead specimens. This study raises the questions: What other animals are out there, pulsating in every different shade of the rainbow after the clock strikes midnight? 

For the first time ever, researchers have “housebroken” cows

Controlling where cow waste ends up could lead to cleaner air and water and decreased greenhouse gas emissions

Fernanda Ruiz Fadel

Animal Behavior and Behavioral Genetics

Advanced Identification Methods GmbH

Feeding extra amino acids to cells with a mutated enzyme makes them grow faster

This new finding could lead to advances in treatment of diseases caused by ARS mutations

Christina Del Greco

Genetics and Genomics

University of Michigan

White pine blister rust’s habitat range is changing with the climate

New study in Sequoia and Kings Canyon National Parks demonstrates the complexity of changing plant-pathogen interactions

Ornob Alam

Population Genetics

New York University

These uses of poop for protection are stranger than fiction

Defense by dung doesn’t always elicit disgust in predators to repel them

Simon Spichak

Neuroscience

Distance and our eyes distort the true colors of stars

New research calculates the colors of stars based on their actual energy distributions

Briley Lewis

Astronomy and Astrophysics

University of California, Los Angeles

Zebrafish without “love hormone” neurons show no desire to socialize with each other

New research shows the importance of oxytocin for social affiliation and isolation

Kareem Clark

Neuroscience

Virginia Polytechnic Institute and State University

Wild Goffin’s cockatoos can use tools, too

Scientists have observed captive cockatoos making tools before, but this is the first documented instance of tool use in wild cockatoos

Fernanda Ruiz Fadel

Animal Behavior and Behavioral Genetics

Advanced Identification Methods GmbH

Giant clams are growing faster than ever. That’s not a good thing

This supercharged growth is likely due to nitrate aerosols in our modern atmosphere

Sarah Heidmann

Fish Ecology

University of the Virgin Islands

The growth of modern giant clams is supercharged compared to growth measured from fossil clams. A recent study from the Red Sea has shown this, finding that growth lines from modern species are larger than those of fossils from similar animals dated to the Holocene and Pleistocene.

These increased growth rates appear to be related to higher amounts of nitrate aerosols in the modern atmosphere. These come from many different sources. Some are natural, such as lightning, biomass burning, and soil processing, but most are from anthropogenic activity like burning fossil fuels and agricultural fertilization.

This fast growth may seem like a good thing, but growth doesn’t mean anything about the overall health of the clams. Additionally, aerosols may actually reduce the productivity of marine phytoplankton, which represent almost half of the world’s primary production.

The overall effects of nitrate and other aerosol pollution on global land and ocean cycles are not well understood. They may appear to reduce global warming by improving carbon dioxide uptake and reflecting the sun’s heat, but they contribute to poor air quality. We can congratulate today’s super clams on their impressive growth. But in the long run, fewer emissions on our part are probably better for them.

Skeletons’ broken clavicles tell a centuries-old tale of humans and horses

Clavicle fractures can be used to identify horse riders from their bones

Katie East

Biological Anthropology

SNA International

One thousand years ago, archers rode horses across the landscape of Hungary. They were probably intimidating, possibly threatening, and definitely adventurous, but just like equestrians today, they also fell a lot.

These horse riders remain a mystery. Who were they? Where were they from? When did they start riding horses? To answer these questions, an international team of scientists set out to find a way to identify horse riders from just their skeletons, using the fact that horse riders tend to fall. 

The researchers examined skeletons from a cemetery of well-known horse riders in Hungary dating to the 10th century CE. Riders in the cemetery were identified by horse riding equipment and horse bones in their graves. However, scientists could not be sure that skeletons without artifacts in the Hungarian cemetery never rode horses.  Therefore, they also investigated skeletons from another group of people from 20th century Portugal that definitely did not ride horses.

They found that upper body fractures were more common among riders, and that fractures of the clavicle (collar bone) were significantly more common among the Hungarian riders than the 20th century non-riders. To figure out if these fractures could be caused by horse riding, researchers turned to modern equestrians. Sure enough, fractures of the upper body, especially the clavicle, are some of the most commonly reported injuries in modern day equestrians.

The researchers argue that, in combination with other skeletal changes, clavicle fractures can be used to identify horse riders from just their skeletons. Being able to identify horse riders in the past could help researchers find the first horse riders, shedding light on the ways horse riding shaped human history.

Researchers observe a boar releasing two caged younglings in a impassioned rescue

The act sheds light on the prosocial behavior and empathy of wild boars, thought to be rare among animals

Simon Spichak

Neuroscience

Humans aren’t the only animals that step up to help others out of difficult situations. In a study recently published in the journal Scientific Reports, Michaela Masilkova of the Czech University of Life Sciences and her colleagues described a boar’s daring rescue of two young wild boars stuck in a trap.

Few animals show this kind of rescue behavior: to go out of their way to help other members of their species that are caught in a dangerous situation. Masilkova’s team inadvertently caught an astonishing act of altruism on camera while conducting a separate experiment to monitor wild boar movement for the prevention of African Swine Fever. The goal was to catch boars so the researchers could mark them individually. The researchers set up traps containing food as lure. Once lured inside, a boar would be caged in by logs that would roll off the top of the enclosure and bar the door shut. 

One night the trap — operating as usual — snared two young boars. But the night took an unexpected turn when a new herd arrived at the scene. One adult female took particular interest in the captives’ predicament. Over the course of 29 minutes, the female pushed against the logs and successfully moved it, allowing the young boars to escape. Given that the rescuer spent so much time on this activity and showed physical signs of distress throughout, the researchers believed her act to be potential evidence of pro-social empathy.

This discovery suggests that complex forms of empathy may just be more common in the animal kingdom than scientists may have previously believed. 

Roe deer pause development of their embryos for months, and researchers just learned how

An embryonic phenomenon discovered over 150 years ago may finally have an explanation

Charlotte Douglas

Genetics

Institut Curie Paris

Female jumping spiders favor the most aggressive males

A new study provides evidence for sexual selection in these spiders

Hayden Waller

Evolutionary Biology

Cornell University

If you’ve ever witnessed an overly aggressive guy get bounced from a bar, you probably found yourself internally judging him. But new research published in the journal Animal Behaviour suggests that the opposite may be true for spiders: the more aggressive a male jumping spider is, the sexier his female counterparts find him.

Researchers from the National University of Singapore quantified female spiders’ preferences for aggressive males. They first placed males in a small chamber containing a mirror and observed how combative they were toward their own reflection. Once males had demonstrated either their contempt for or passivity towards their own reflections, they were paired with another male for a series of bouts. Using the results from the mirror test and combat trials, the researchers assigned each individual male spider an aggression predictability score. Finally, a pair of one highly aggressive male and one more passive male were placed in a chamber with a single female spider. Female preference was determined based on the amount of time she spent ogling each of her potential suitors. 

The researchers found that aggressive males are both more likely to defeat a rival in a combat trial, and to draw a higher amount of attention from females than their more pacifist competitors. They concluded that, not only is this evidence for sexual selection, but that the combination of strong competitiveness and female favor reinforce each other to push the most aggressive spiders to the top of the pile. 

People with sickle cell disease are less likely to get kidney transplants than those without

Sickle cell disease predominantly affects Black populations, and kidney transplants can save their lives

Danielle Llaneza

Health and Medicine

Hunter College and MD Anderson Cancer Center

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