Saturday, January 27, 2024

JAMA NETWORK

Incidence of fit test failure during N95 respirator reuse and extended use

About The Study: In this study of 824 N95s used by 412 emergency department health care workers practicing N95 reuse, fit failure occurred in 38.7% of masks after one shift. Trifold N95s had higher incidence of fit failure compared with dome N95s. These results may inform pandemic preparedness, specifically policies related to N95 selection and reuse practices.

Authors: Ralph C. Wang, M.D., M.A.S., of the University of California, San Francisco, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2023.53631)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

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About JAMA Network Open: JAMA Network Open is an online-only open access general medical journal from the JAMA Network. On weekdays, the journal publishes peer-reviewed clinical research and commentary in more than 40 medical and health subject areas. Every article is free online from the day of publication.

JOURNAL

JAMA Network Open

Clinical risk and outpatient therapy utilization for COVID-19 in the Medicare population

JAMA Health Forum

Peer-Reviewed Publication

JAMA NETWORK

About The Study: In this study of patients enrolled in Medicare in 2022, those at the highest risk for severe COVID-19 infection received COVID-19 therapy less often than those with the least risk. Disparities in therapy access were found by patient age, race and ethnicity, Medicaid eligibility, and nursing home residence.

Authors: Michael L. Barnett, M.D., of the Harvard T.H. Chan School of Public Health in Boston, is the corresponding author.

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(doi:10.1001/jamahealthforum.2023.5044)

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About JAMA Health Forum: JAMA Health Forum is an international, peer-reviewed, online, open access journal that addresses health policy and strategies affecting medicine, health and health care. The journal publishes original research, evidence-based reports and opinion about national and global health policy; innovative approaches to health care delivery; and health care economics, access, quality, safety, equity and reform. Its distribution will be solely digital and all content will be freely available for anyone to read.

JOURNAL

JAMA Health Forum

Job flows into and out of health care before and after the pandemic

JAMA Health Forum

Peer-Reviewed Publication

JAMA NETWORK

About The Study: The results of this study of approximately 18 million health care industry employees suggest a substantial and persistent increase in health care workforce turnover after the pandemic, which may have long-lasting implications for workers’ willingness to remain in health care jobs. Policymakers and health care organizations may need to act to prevent further losses of experienced staff.

Authors: Karen Shen, Ph.D., of the Johns Hopkins Bloomberg School of Public Health in Baltimore, is the corresponding author.

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(doi:10.1001/jamahealthforum.2023.4964)

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JOURNAL

JAMA Health Forum

SPACE

Study: Stars travel more slowly at Milky Way’s edge

The findings suggest our galaxy’s core may contain less dark matter than previously estimated.

Peer-Reviewed Publication
MASSACHUSETTS INSTITUTE OF TECHNOLOGY

IMAGE:
A STUDY BY MIT PHYSICISTS SUGGEST THE MILKY WAY’S GRAVITATIONAL CORE MAY BE LIGHTER IN MASS, AND CONTAIN LESS DARK MATTER, THAN PREVIOUSLY THOUGHT.
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CREDIT: ESA/GAIA/DPAC

By clocking the speed of stars throughout the Milky Way galaxy, MIT physicists have found that stars further out in the galactic disk are traveling more slowly than expected compared to stars that are closer to the galaxy’s center. The findings raise a surprising possibility: The Milky Way’s gravitational core may be lighter in mass, and contain less dark matter, than previously thought.
The new results are based on the team’s analysis of data taken by the Gaia and APOGEE instruments. Gaia is an orbiting space telescope that tracks the precise location, distance, and motion of more than 1 billion stars throughout the Milky Way galaxy, while APOGEE is a ground-based survey. The physicists analyzed Gaia’s measurements of more than 33,000 stars, including some of the farthest stars in the galaxy, and determined each star’s “circular velocity,” or how fast a star is circling in the galactic disk, given the star’s distance from the galaxy’s center.
The scientists plotted each star’s velocity against its distance to generate a rotation curve — a standard graph in astronomy that represents how fast matter rotates at a given distance from the center of a galaxy. The shape of this curve can give scientists an idea of how much visible and dark matter is distributed throughout a galaxy.
“What we were really surprised to see was that this curve remained flat, flat, flat out to a certain distance, and then it started tanking,” says Lina Necib, assistant professor of physics at MIT. “This means the outer stars are rotating a little slower than expected, which is a very surprising result.”
The team translated the new rotation curve into a distribution of dark matter that could explain the outer stars’ slow-down, and found the resulting map produced a lighter galactic core than expected. That is, the center of the Milky Way may be less dense, with less dark matter, than scientists have thought.
“This puts this result in tension with other measurements,” Necib says. “There is something fishy going on somewhere, and it’s really exciting to figure out where that is, to really have a coherent picture of the Milky Way.”
The team reports its results this month in the Monthly Notices of the Royal Society Journal. The study’s MIT co-authors, including Necib, are first author Xiaowei Ou, Anna-Christina Eilers, and Anna Frebel.
“In the nothingness”
Like most galaxies in the universe, the Milky Way spins like water in a whirlpool, and its rotation is driven, in part, by all the matter that swirls within its disk. In the 1970s, astronomer Vera Rubin was the first to observe that galaxies rotate in ways that cannot be driven purely by visible matter. She and her colleagues measured the circular velocity of stars and found that the resulting rotation curves were surprisingly flat. That is, the velocity of stars remained the same throughout a galaxy, rather than dropping off with distance. They concluded that some other type of invisible matter must be acting on distant stars to give them an added push.
Rubin’s work in rotation curves was one of the first strong pieces of evidence for the existence of dark matter — an invisible, unknown entity that is estimated to outweigh all the stars and other visible matter in the universe.
Since then, astronomers have observed similar flat curves in far-off galaxies, further supporting dark matter’s presence. Only recently have astronomers attempted to chart the rotation curve in our own galaxy with stars.
“It turns out it’s harder to measure a rotation curve when you’re sitting inside a galaxy,” Ou notes.
In 2019, Anna-Christina Eilers, assistant professor of physics at MIT, worked to chart the Milky Way’s rotation curve, using an earlier batch of data released by the Gaia satellite. That data release included stars as far out as 25 kiloparsecs, or about 81,000 light years, from the galaxy’s center.
Based on these data, Eilers observed that the Milky Way’s rotation curve appeared to be flat, albeit with mild decline, similar to other far-off galaxies, and by inference, the galaxy likely bore a high density of dark matter at its core. But this view now shifted, as the telescope released a new batch of data, this time including stars as far out as 30 kiloparsecs — almost 100,000 light years from the galaxy’s core.
“At these distances, we’re right at the edge of the galaxy where stars start to peter out,” Frebel says. “No one had explored how matter moves around in this outer galaxy, where we’re really in the nothingness.”
Weird tension
Frebel, Necib, Ou, and Eilers jumped on Gaia’s new data, looking to expand on Eilers’ initial rotation curve. To refine their analysis, the team complemented Gaia’s data with measurements by APOGEE — the Apache Point Observatory Galactic Evolution Experiment, which measures extremely detailed properties of more than 700,000 stars in the Milky Way, such as their brightness, temperature, and elemental composition.
“We feed all this information into an algorithm to try to learn connections that can then give us better estimates of a star’s distance,” Ou explains. “That’s how we can push out to farther distances.”
The team established the precise distances for more than 33,000 stars and used these measurements to generate a three-dimensional map of the stars scattered across the Milky Way out to about 30 kiloparsecs. They then incorporated this map into a model of circular velocity, to simulate how fast any one star must be traveling, given the distribution of all the other stars in the galaxy. They then plotted each star’s velocity and distance on a chart to produce an updated rotation curve of the Milky Way.
“That’s where the weirdness came in,” Necib says.
Instead of seeing a mild decline like previous rotation curves, the team observed that the new curve dipped more strongly than expected at the outer end. This unexpected downturn suggests that while stars may travel just as fast out to a certain distance, they suddenly slow down at the farthest distances. Stars at the outskirts appear to travel more slowly than expected.
When the team translated this rotation curve to the amount of dark matter that must exist throughout the galaxy, they found that the Milky Way’s core may contain less dark matter than previously estimated.
“This result is in tension with other measurements,” Necib says. “Really understanding this result will have deep repercussions. This might lead to more hidden masses just beyond the edge of the galactic disk, or a reconsideration of the state of equilibrium of our galaxy. We seek to find these answers in upcoming work, using high resolution simulations of Milky Way-like galaxies."
This research was funded, in part, by the National Science Foundation.
###
Written by Jennifer Chu, MIT News
Paper: “The dark matter profile of the Milky Way inferred from its circular velocity curve”
https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stae034/7513209
JOURNAL
Monthly Notices of the Royal Astronomical Society
DOI
10.1093/mnras/stae034
ARTICLE TITLE
The dark matter profile of the Milky Way inferred from its circular velocity curve”

UC Irvine-led team unravels mysteries of planet formation and evolution in distant solar system

Astronomers analyze masses, orbital properties and atmospheric features of six exoplanets

Peer-Reviewed Publication
UNIVERSITY OF CALIFORNIA - IRVINE

IMAGE:
A TEAM OF RESEARCHERS LED BY ASTRONOMERS AT UCI HAS OBTAINED HIGHLY PRECISE INFORMATION ABOUT SIX CONFIRMED EXOPLANETS ORBITING TOI-1136, A DWARF STAR ABOUT 270 LIGHT YEARS FROM EARTH.

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CREDIT: CREDIT: RAE HOLCOMB / UCI

A recently discovered solar system with six confirmed exoplanets and a possible seventh is boosting astronomers’ knowledge of planet formation and evolution. Relying on a globe-spanning arsenal of observatories and instruments, a team led by researchers at the University of California, Irvine has compiled the most precise measurements yet of the exoplanets’ masses, orbital properties and atmospheric characteristics.
In a paper published today in The Astronomical Journal, the researchers share the results of the TESS-Keck Survey, providing a thorough description of the exoplanets orbiting TOI-1136, a dwarf star in the Milky Way galaxy more than 270 light years from Earth. The study is a follow-up to the team’s initial observation of the star and exoplanets in 2019 using data from the Transiting Exoplanet Survey Satellite. That project provided the first estimate of the exoplanets’ masses by clocking transit timing variations, a measure of the gravitational pull that orbiting planets exert on one another.
For the most recent study, the researchers joined TTV data with a radial velocity analysis of the star. Using the Automated Planet Finder telescope at the Lick Observatory on California’s Mount Hamilton and the High-Resolution Echelle Spectrometer at the W.M. Keck Observatory on Hawaii’s Mauna Kea, they could detect slight variations in stellar motion via the redshift and blueshift of the Doppler effect – which helped them determine planetary mass readings of unprecedented precision.
To obtain such exact information on the planets in this solar system, the team built computer models using hundreds of radial velocity measurements layered over TTV data. Lead author Corey Beard, a UCI Ph.D. candidate in physics, said that combining these two types of readings yielded more knowledge about the system than ever before.
“It took a lot of trial and error, but we were really happy with our results after developing one of the most complicated planetary system models in exoplanet literature to date,” Beard said.
The large number of planets is one factor that inspired the astronomy team to conduct further research, according to co-author Paul Robertson, UCI associate professor of physics & astronomy.
“We viewed TOI-1136 as being highly advantageous from a research standpoint, because when a system has multiple exoplanets, we can control for the effects of planet evolution that depend on the host star, and that helps us focus on individual physical mechanisms that led to these planets having the properties that they do,” he said.
Robertson added that when astronomers try to compare planets in separate solar systems, there are many variables that can differ based on the distinct properties of the stars and their locations in disparate parts of the galaxy. He said that looking at exoplanets in the same system enables the study of planets that have experienced a similar history.
By stellar standards, TOI-1136 is young, a mere 700 million years old, another feature that has attracted exoplanet hunters. Robertson said that juvenile stars are both “difficult and special” to work with because they’re so active. Magnetism, sunspots and solar flares are more prevalent and intense during this stage of a star’s development, and the resulting radiation blasts and sculpts planets, affecting their atmospheres.
TOI-1136’s confirmed exoplanets, TOI-1136 b through TOI-1136 g, are categorized as “sub-Neptunes” by the experts. Robertson said the smallest one is more than twice the radius of Earth, and others are up to four times Earth’s radius, comparable to the sizes of Uranus and Neptune.
All these planets orbit TOI-1136 in less than the 88 days it takes Mercury to go around Earth’s sun, according to the study. “We’re packing an entire solar system into a region around the star so small that our entire planetary system here would be outside of it,” Robertson said.
“They’re weird planets to us because we don’t have anything exactly like them in our solar system,” said co-author Rae Holcomb, a UCI Ph.D. candidate in physics. “But the more we study other planet systems, it seems like they may be the most common type of planet in the galaxy.”
Another odd component to this solar system is the possible yet unconfirmed presence of a seventh planet. The researchers have detected some evidence of another resonant force in the system. Robertson explained that when planets are orbiting close to one another, they can pull on each other gravitationally.
“When you hear a chord played on a piano and it sounds good to you, it’s because there is resonance, or even spacing, between the notes that you’re hearing,” he said. “The orbital periods of these planets are spaced similarly. When the exoplanets are in resonance, the tugs are in the same direction every time. This can have a destabilizing effect, or in special cases, it can serve to make the orbits more stable.”
Robertson noted that far from answering all his team’s questions about the exoplanets in this system, the survey has made the researchers want to pursue additional knowledge, particularly about the composition of planetary atmospheres. That line of inquiry would be best approached through the advanced spectroscopy capabilities of NASA’s James Webb Space Telescope, he said.
“I am proud that both UCO’s Lick Observatory and the Keck Observatories were involved in the characterization of a really important system,” said Matthew Shetrone, deputy director of UC Observatories. “Having so many moderate-sized planets in the same system really lets us test formation scenarios. I really want to know more about these planets! Might we find a molten rock world, a water world and an ice world all in the same solar system? It almost feels like science fiction.”
Joining Robertson and Beard on this study were researchers from Spain’s Astrophysics Institute of the Canary Islands; the California Institute of Technology; Sweden’s Chalmers University of Technology; Maryland’s Johns Hopkins University; Spain’s University of La Laguna; Sweden’s Lund University; Poland’s Nicolaus Copernicus University; New Jersey’s Princeton University; Japan’s Ritsumeikan University; California’s SETI Institute; Maryland’s Space Telescope Science Institute; the University of California, Santa Cruz; the University of California, Berkeley; the University of California, Los Angeles; the University of California, Riverside; the University of Hawaii; the University of Chicago; the University of Kansas; Indiana’s University of Notre Dame; Australia’s University of Southern Queensland; and Connecticut’s Yale University. Funding was provided by the W.M. Keck Foundation, NASA and the National Science Foundation.
About the University of California, Irvine: Founded in 1965, UCI is a member of the prestigious Association of American Universities and is ranked among the nation’s top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UCI has more than 36,000 students and offers 224 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UCI, visit www.uci.edu.
Media access: Radio programs/stations may, for a fee, use an on-campus ISDN line to interview UCI faculty and experts, subject to availability and university approval. For more UCI news, visit news.uci.edu. Additional resources for journalists may be found at https://news.uci.edu/media-resources/.
JOURNAL
The Astronomical Journal
DOI
10.48550/arXiv.2312.04635
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
The TESS-Keck Survey XVII: Precise Mass Measurements in a Young, High Multiplicity Transiting Planet System using Radial Velocities and Transit Timing Variations
ARTICLE PUBLICATION DATE
29-Jan-2024

Confirmation of ancient lake on Mars builds excitement for Perseverance rover's samples

Findings reveal eons of environmental changes and offer hope that the rover’s soil and rock samples hold traces of life

Peer-Reviewed Publication
UNIVERSITY OF CALIFORNIA - LOS ANGELES

IMAGE:
MARS PERSEVERANCE ROVER RIMFAX GROUND PENETRATING RADAR MEASUREMENTS OF THE HAWKSBILL GAP REGION OF THE JEZERO CRATER WESTERN DELTA, MARS. HAWKSBILL GAP.
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CREDIT: SVEIN-ERIK HAMRAN, TOR BERGER, DAVID PAIGE, UNIVERSITY OF OSLO, UCLA, CALIFORNIA INSTITUTE OF TECHNOLOGY JET PROPULSION LABORATORY, NASA

If life ever existed on Mars, the Perseverance rover’s verification of lake sediments at the base of the Jezero crater reinforces the hope that traces might be found in the crater.
In new research published in the journal Science Advances, a team led by UCLA and The University of Oslo shows that at some point, the crater filled with water, depositing layers of sediments on the crater floor. The lake subsequently shrank and sediments carried by the river that fed it formed an enormous delta. As the lake dissipated over time, the sediments in the crater were eroded, forming the geologic features visible on the surface today.
The periods of deposition and erosion took place over eons of environmental changes, the radar indicates, confirming that inferences about the Jezero crater’s geologic history based on Mars images obtained from space are accurate.
“From orbit we can see a bunch of different deposits, but we can’t tell for sure if what we’re seeing is their original state, or if we’re seeing the conclusion of a long geological story,” said David Paige, a UCLA professor of Earth, planetary and space sciences and first author of the paper. “To tell how these things formed, we need to see below the surface.”
The rover, which is about the size of a car and carries seven scientific instruments, has been exploring the 30-mile-wide crater, studying its geology and atmosphere and collecting samples since 2021. Perseverance’s soil and rock samples will be brought back to Earth by a future expedition and studied for evidence of past life.
Between May and December 2022, Perseverance drove from the crater floor onto the delta, a vast expanse of 3 billion-year-old sediments that, from orbit, resembles the river deltas on Earth.
As the rover drove onto the delta, Perseverance’s Radar Imager for Mars’ Subsurface Experiment, or RIMFAX, instrument fired radar waves downward at 10-centimeter intervals and measured pulses reflected from depths of about 20 meters below the surface. With the radar, scientists can see down to the base of the sediments to reveal the top surface of the buried crater floor.
Years of research with ground-penetrating radar and testing of RIMFAX on Earth have taught scientists how to read the structure and composition of subsurface layers from their radar reflections. The resulting subsurface image shows rock layers that can be interpreted like a highway road cut.
“Some geologists say that the ability of radar to see under the surface is kind of like cheating,” said Paige, who is RIMFAX’s deputy principal investigator.
RIMFAX imaging revealed two distinct periods of sediment deposition sandwiched between two periods of erosion. UCLA and the University of Oslo report that the crater floor below the delta is not uniformly flat, suggesting that a period of erosion occurred prior to the deposition of lake sediments. The radar images show that the sediments are regular and horizontal - just like sediments deposited in lakes on Earth. The existence of lake sediments had been suspected in previous studies, but has been confirmed by this research.
A second period of deposition occurred when fluctuations in the lake level allowed the river to deposit a broad delta that once extended far out into the lake, but has now eroded back closer to the river’s mouth.
“The changes we see preserved in the rock record are driven by large-scale changes in the Martian environment,” Paige said. “It’s cool that we can see so much evidence of change in such a small geographic area, which allows us extend our findings to the scale of the entire crater.”
Mars Perseverance Rover RIMFAX ground penetrating radar measurements of the Hawksbill Gap region of the Jezero Crater Western Delta, Mars.
CREDIT
Svein-Erik Hamran, Tor Berger, David Paige, University of Oslo, UCLA, California Institute of Technology Jet Propulsion Laboratory, NASA
Cape_Nukshak_3D_Radar_Profile

Mars Perseverance Rover RIMFAX ground penetrating radar measurements of the Cape Nukshak region of the Jezero Crater Western Delta, Mars.
CREDIT
Svein-Erik Hamran, Tor Berger, David Paige, University of Oslo, UCLA, California Institute of Technology Jet Propulsion Laboratory, NASA
Perseverance_Sol_641_Traverse (VIDEO)
AI-interpolated video from NAVCAM images from the NASA Perseverance Rover’s as it traversed down the Jezero Western Delta from Cape Nukshak to the Crater Floor on Sol 641.
CREDIT
Lior Rubanenko, Emily Cardarelli, Justin Maki, David Paige, UCLA, California Institute of Technology Jet Propulsion Laboratory, NASA
JOURNAL
Science Advances
DOI
10.1126/sciadv.adi8339
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Ground penetrating radar observations of the contact between the western delta and the crater floor of Jezero Crater, Mars
ARTICLE PUBLICATION DATE
26-Jan-2024

Hubble finds water vapor in small planet's atmosphere

Agence France-Presse
January 26, 2024

The Hubble Space Telescope NASA/AFP/File /

The Hubble Space Telescope has observed the smallest planet outside our solar system to contain water vapor in its atmosphere, a "landmark discovery" that brings astronomy a step closer to characterizing Earth-like worlds.

At around twice Earth's diameter, planet GJ 9827d orbits a red dwarf star 97 light-years away in the constellation Pisces, NASA and the European Space Agency (ESA) said in statements on Thursday.

The team behind the finding are examining two scenarios: either the planet is a "mini-Neptune" with a hydrogen-rich atmosphere laced with water, or it's a warmer version of Jupiter's moon Europa, which contains twice as much water as Earth under its crust.

"The planet GJ 9827d could be half water, half rock," said Bjorn Benneke of the Universite de Montreal, who co-led the research. "And there would be a lot of water vapor on top of some smaller rocky body."

"Until now, we had not been able to directly detect the atmosphere of such a small planet. And we're slowly getting in this regime now," he added.

Over a period of three years, Hubble observed the planet during 11 transients, or events in which it crossed in front of its star.

During transients, starlight is filtered through the planet's atmosphere, allowing astronomers to use Hubble's instruments to analyze the patterns of colors (wavelengths), which revealed the telltale signature of water molecules.

Even if GJ 9827d has a water-rich atmosphere, its hot, Venus-like temperature of 800 degrees Fahrenheit (425 Celsius) would make it an uninhabitable steamy world.

Nevertheless, the Hubble discovery paves the way to future study of GJ 9827d and similar planets, especially by the James Webb Space Telescope, which can use its high resolution infrared images to look for more atmospheric molecules including carbon dioxide, and methane.

"Water on a planet this small is a landmark discovery," added co-leader Laura Kreidberg of Max Planck Institute for Astronomy in Germany.

"It pushes closer than ever to characterizing truly Earth-like worlds."

‘Old smokers’: Strange new type of star discovered in Milky Way

By AFP

January 26, 2024

Astronomers have nicknamed the stars "old smokers"

- Copyright ANP/AFP Remko de Waal

Daniel Lawler

Nearing the end of their life, they sit quietly for long periods of time, barely noticeable, before suddenly puffing out a cloud of smoke.

A mysterious new type of star nicknamed “old smoker” has been discovered hiding in the heart of our Milky Way galaxy, astronomers revealed on Friday.

The “peculiar” puffing behaviour of these stars has never been seen before in such red giants, astrophysicist Philip Lucas told AFP.

The international team of scientists behind the discovery had not been looking for such old stars during their 10-year survey, which took in hundreds of millions of stars across the sky.

Instead they were using the VISTA telescope in the Chilean Andes to search for newborn stars — called proto-stars — which are prone to frequent, exuberant eruptions.

A newborn star, called a proto-star, observed by the VISTA telescope in the Chilean Andes. — AFP

They spotted 32 proto-stars, “the largest number anyone has ever found before in one batch”, said Lucas, a professor at the UK’s University of Hertfordshire and lead author of a new study.

But lingering in the background was a “nice surprise”, he added.

– ‘We don’t fully understand’ –

The old smokers were puffing right in the centre of the Milky Way, a densely packed and metal-rich region called the Nuclear Stellar Disc.

“What was surprising about this new discovery is that we’re seeing stars that were just sitting doing nothing at all,” Lucas said.

Then abruptly the stars would become between 40 to 100 times dimmer, sometimes so faint that the telescope’s infrared vision could barely spot them.

A couple of years later, seemingly without warning, they would return to their former brightness.

“Everything we have been able to learn about them suggests that this is a case of stars throwing off puffs of smoke — for reasons that we don’t fully understand,” Lucas said.

The “old smokers” are about 30,000 light years away, near the centre of our galaxy. — ©AFP

Those smoke puffs are thought to temporarily obscure the stars from our sight.

There are many more “heavy elements” — anything heavier than hydrogen and helium — in this region of the galaxy, which could create more dust in the star’s atmosphere, Lucas said.

Exactly what puffs that dust out remains a mystery.

But if this theory is correct, then the amount of matter being thrown off by these stars could play a significant role in how heavy elements are spread throughout our galaxy — and beyond, he said.

Lucas emphasised that these were just early best-guesses.

“We’re just sort of scrabbling around trying to see what makes the most sense,” he said.

The researchers spotted at least 21 old smokers but suspect there are many more out there.

The study was published in the Monthly Notices of the Royal Astronomical Society.

Japan’s little Moon toy: the camera probe ready to roll

By AFP
January 19, 2024

The shape-shifting SORA-Q probe.

Photo credit: JAXA, Takara Tomy, Sony Group Corporation and Doshisha University

Natsuko FUKUE

On board Japan’s “Moon Sniper” spacecraft is a little robot with a big mission: to pop open like a Transformer toy, wiggle across the lunar surface and beam images back to Earth.

The shape-shifting SORA-Q probe — co-developed by a major toy company — has been compared to a friendly “Star Wars” droid and a sea turtle because of the way its metal form can navigate the dusty Moonscape.

But the gadget’s chance to boldly go depends on the success of the Smart Lander for Investigating Moon (SLIM) mission, with a spacecraft dubbed the “Moon Sniper” by space agency JAXA for its precision landing capabilities.

The lightweight craft is due to begin its descent from lunar orbit at midnight on Saturday morning (1500 GMT Friday), with touchdown planned around 20 minutes later.

But success, which would make Japan the fifth nation to land on the Moon after the United States, the Soviet Union, China and India, is far from guaranteed.

Slightly bigger than a tennis ball and weighing as much as a large potato — eight centimetres (three inches) across and 250 grams (half a pound) — SORA-Q was designed by JAXA with Takara Tomy, the toy company behind the original 1984 Transformers.

Sony Group and Doshisha University in Kyoto also helped develop the device, which has a front camera on an orange panel that emerges when the its metal frame snaps open, and another on its back.

Instead of rolling on wheels, the two halves of the sphere are designed to slot out and move in tandem to propel SORA-Q along the rocky surface, a design that reduces size and weight.

“The form-shifting mechanism and ultra-compact, ultra-lightweight design have been created using the technical know-how of toy development,” the probe’s website reads.

It can move in two ways, allowing it to drive on inclines: “‘Butterfly’ driving, where both the left and right wheels move together, and ‘crawl’ driving, where they move separately,” the site explains.

Sora means “universe” in Japanese, while “Q” refers to the words “question” and “quest”, its makers say.

If the mission succeeds, the probe’s cameras will take valuable images of a crater where parts of the Moon’s mantle, usually hidden deep below its crust, are believed to be exposed.

Back on Earth, a toy version of the probe costs 21,190 yen ($140) and can roll around a living room to take pictures of cats and babies, according to its promotional video.

Political polarization may slow legislation, make higher-stakes laws likelier

Peer-Reviewed Publication

PENN STATE

The United States House of Representatives held more than 700 votes in 2023, but fewer than 30 bills were signed into law. Partisan politics may explain why, with polarization potentially causing enough friction to slow down the legislative process and make the passage of fewer, farther-reaching public laws likelier, according to researchers.

The collaborators from Penn State and Colorado State University studied levels of polarization and patterns in the passage of budget bills and public laws from 1948 through 2020. They found that as polarization increased, especially in the mid-1990s and 2000s, Congress passed fewer bills, but the bills they did pass were larger and led to more dramatic changes in public policy. They reported their findings in the Policy Studies Journal.

“Punctuated equilibrium theory is the idea that in the American policy process you tend to see periods of stasis or incremental changes occurring over time, and then occasionally bigger punctuations happen, like the passage of the Affordable Care Act or a big infrastructure bill,” said study co-author Daniel Mallinson, associate professor of public policy and administration at Penn State Harrisburg. “We found that as polarization has increased in the U.S., these dynamics of stasis and punctuation have gotten exaggerated. This happens because polarization introduces greater friction in policymaking, so it’s harder to change the status quo, but when you do, the change is bigger.”

The researchers focused on budget bills because of the ease of calculating percentage changes in line items from year to year, allowing them to capture incremental versus big changes. For the public laws analysis, they focused on the number of bills passed each year excluding symbolic laws, such as the renaming of a post office. The researchers used a five-year moving average approach — where the first five-year window covers years 1948-52, the second five-year window covers years 1949-53, and so on — to calculate kurtosis, or the distribution of these periods of stasis and punctuation in policymaking over time.

They used measurements of the difference of mean party ideology in the U.S. House of Representatives to track polarization over time. Then they plotted budget kurtosis, public law kurtosis and polarization over time and conducted additional analyses to see if factors like divided government could account for exaggerated patterns in the data.

“Our findings indicate that, while ‘gridlock’ is not accurately descriptive of Congressional behavior, we are seeing an increasingly unstable policy process, characterized by long periods of inaction punctuated by moments of enormous volatility,” said Clare Brock, first author of the study and assistant professor of American politics and public policy at Colorado State University. “This is not a new pattern, but it is becoming more exaggerated.”

The researchers found a correlation between polarization and periods of stasis and punctuation in policymaking. As polarization jumped in the 1990s and during President Barack Obama’s administration, the periods of stasis grew longer and Congress passed fewer bills, but the bills that did pass included large-scale changes in budgets.

“The scholarly and public narratives for a while now have been that Congress doesn’t do anything,” Mallinson said. “This work shows that maybe numerically Congress is doing less, not passing as much legislation or perhaps there is more stasis because of the effects of polarization, but Congress is still doing work that is important to the American public and impacts Americans’ lives.”

Understanding that government still works even during periods of stasis in policymaking is important for maintaining a healthy democracy, according to Mallinson. He and Brock are currently working on a book that examines polarization and its effects on policymaking in more detail.

“It’s a concerning belief when you think the government isn’t doing anything for you,” Mallinson said. “We see that belief manifest in populism and populist support for divisive candidates who take advantage of and perpetuate that problematic belief.”

JOURNAL

Policy Studies Journal

DOI

10.1111/psj.12519

ARTICLE TITLE

Measuring the stasis: Punctuated equilibrium theory and partisan polarization

How waves and mixing drive coastal upwelling systems

GEOMAR study provides new insights into productivity off the coast of Angola

Peer-Reviewed Publication

HELMHOLTZ CENTRE FOR OCEAN RESEARCH KIEL (GEOMAR)

They are among the most productive and biodiverse areas of the world's oceans: coastal upwelling regions along the eastern boundaries of the Atlantic and Pacific Oceans. There, equatorward winds cause near-surface water to move away from the coast. This brings cold, nutrient-rich water from the depths to the surface, inducing the growth of phytoplankton and providing the basis for a rich marine ecosystem in these regions.

In some tropical regions, however, productivity is high even when the upwelling favourable winds are weak. An international team of researchers has now investigated the physical mechanisms driving the upwelling off the coast of Angola. They found that the combination of coastal trapped waves and increased mixing on the shelf control productivity in this system. Their findings, published today in the journal Science Advances, could help predict the strength of seasonal productivity peaks.

"Productivity in the upwelling region off Angola shows strong seasonal fluctuations," says corresponding author Mareike Körner, PhD student in the Research Unit Physical Oceanography at the GEOMAR Helmholtz Centre for Ocean Research Kiel. "The main upwelling season occurs in austral winter, from July to September. During this time, there is very high primary productivity in the waters off the Angolan coast, and correspondingly, there is a lot of fishing".

Waves in the interior of the ocean play a crucial role for productivity, causing cold, nutrient-rich water to move up and down on seasonal time scales. These waves are not generated locally off the coast of Angola but originate at the equator. There, seasonal wind fluctuations create waves that travel east along the equator. Once they reach the eastern boundary of the equatorial Atlantic, they excite coastal trapped waves, which propagate polewards along the African coast. On their way, these coastal trapped waves transport nutrient-rich waters onto the Angolan shelf. Strong tidal mixing on the shelf brings the nutrients to the surface, where a phytoplankton bloom is induced. These plankton blooms can vary from year to year, depending on the intensity and arrival time of the coastal trapped waves.

For their study, the researchers combined hydrographic, oxygen, nitrate and satellite data, and a regional ocean model.

Körner emphasises: "The upwelling off Angola is caused by waves that are excited at the equator and then propagate along the African coast. This provides a potential for predicting the strength and timing of the biological productivity peak off Angola on seasonal time scales.” A better understanding of the driving mechanisms in this southwest African coastal upwelling system is also crucial for assessing possible future changes, such as the effects of climate change or other human impacts, in this important marine ecosystem.

At GEOMAR "Upwelling in the Atlantic Ocean" is a research focus as part of the GEOMAR 2030 strategy. Since 2013 GEOMAR has been conducting research in the area and has established extensive cooperation with Angolan colleagues. Seven research cruises led by the Research Unit Physical Oceanography have provided extensive data on mixing and distribution of nutrients on the shelf. In addition, a subsurface mooring has been collecting data on various parameters such as current velocities, temperature, salinity and oxygen since 2013.

JOURNAL

Science Advances

DOI

10.1126/sciadv.adj6686

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Coastal trapped waves and tidal mixing control primary production in the tropical Angolan upwelling system

ARTICLE PUBLICATION DATE

26-Jan-2024