. Scientific Frontline

Thursday, October 12, 2023

Close con­nectiv­ity within the North At­lantic Cur­rent sys­tem iden­ti­fied

An acous­tic cur­rent meter, built into a moor­ing buoy be­ing pre­pared for de­ploy­ment in the At­lantic. The ocean cur­rent is meas­ured with these in­stru­ments.
Photo Credit: MARUM – Cen­ter for Mar­ine En­vir­on­mental Sci­ences, Uni­versity of Bre­men, D. Kieke

Long-term com­par­at­ive study re­veals par­al­lels between time series from Flor­ida and New­found­land

Re­search­ers from the Uni­versity of Bre­men and the Fed­eral Mari­time and Hy­dro­graphic Agency have com­pared long-term data on the At­lantic Me­ri­di­onal Over­turn­ing Cir­cu­la­tion from two dif­fer­ent lat­it­udes and dis­covered a stat­ist­ical cor­rel­a­tion. Their aim was to in­vest­ig­ate how the At­lantic Me­ri­di­onal Over­turn­ing Cir­cu­la­tion has de­veloped over a period of 25 years, based on moored ob­ser­va­tion sta­tions. These data will help to re­fine cli­mate mod­els in the fu­ture. The study has been pub­lished in the journal Geophysical Research Letters.

In ad­di­tion to wind, tem­per­at­ure and sa­lin­ity are the driv­ing forces of ocean cur­rents in the North At­lantic. They trans­port warm, salty wa­ter from the sub­trop­ical re­gions north­ward to the colder, lower-sa­lin­ity areas. Like the wind-driven Gulf Stream, these cur­rents are com­pon­ents of the At­lantic Me­ri­di­onal Over­turn­ing Cir­cu­la­tion (AMOC). Be­cause of the im­mense amount of heat it trans­ports, the AMOC is an im­port­ant part of the global cli­mate sys­tem. For ex­ample, it in­flu­ences re­gional pre­cip­it­a­tion as well as strong trop­ical storms, and acts as a re­mote heat­ing sys­tem for Europe’s cli­mate.

A new lens” into the Universe’s most energetic particles

An example of a cosmic-ray extensive air shower recorded by the Subaru Telescope. The highlighted tracks, which are mostly aligned in similar directions, show the shower particles induced from a high-energy cosmic ray. 
Image Credit: National Astronomical Observatory of Japan, Hyper Suprime-Cam (HSC) Collaboration

Showers in bathrooms bring us comfort; showers from space bring astrophysicists joy. Osaka Metropolitan University scientists have observed, with their novel method, cosmic-ray extensive air showers with unprecedented precision, opening the door to new insights into the Universe’s most energetic particles.

When a high energy cosmic ray collides with the Earth's atmosphere, it generates an enormous number of particles known as an extensive air shower. A research team led by Associate Professor Toshihiro Fujii from the Graduate School of Science and Nambu Yoichiro Institute of Theoretical and Experimental Physics at Osaka Metropolitan University, along with graduate student Fraser Bradfield, has discovered that the prime-focus wide field camera mounted on the Subaru Telescope, situated atop the Mauna Kea volcano in Hawaii, can capture these extensive air showers with extremely high resolution.

Wednesday, October 11, 2023

“Starquakes” could explain mystery signals

Earthquake map. Data on earthquakes was taken from Japan’s Kanto region (including Tokyo and Narita) and Izumo in the Chugoku region (north of Hiroshima). Black dots represent the epicenters of earthquakes recorded between May 6, 2010, and December 31, 2012.
Image Credit: ©2023 T. Totani & Y. Tsuzuki

Fast radio bursts, or FRBs, are an astronomical mystery, with their exact cause and origins still unconfirmed. These intense bursts of radio energy are invisible to the human eye, but show up brightly on radio telescopes. Previous studies have noted broad similarities between the energy distribution of repeat FRBs, and that of earthquakes and solar flares. However, new research at the University of Tokyo has looked at the time and energy of FRBs and found distinct differences between FRBs and solar flares, but several notable similarities between FRBs and earthquakes. This supports the theory that FRBs are caused by “starquakes” on the surface of neutron stars. This discovery could help us better understand earthquakes, the behavior of high-density matter and aspects of nuclear physics.

The vastness of space holds many mysteries. While some people dream of boldly going where no one has gone before, there is a lot we can learn from the comfort of Earth. Thanks to technological advances, we can explore the surface of Mars, marvel at Saturn’s rings and pick up mysterious signals from deep space. Fast radio bursts are hugely powerful, bright bursts of energy which are visible on radio waves. First discovered in 2007, these bursts can travel billions of light years but typically last mere thousandths of a second. It has been estimated that as many as 10,000 FRBs may happen every day if we could observe the whole sky. While the sources of most bursts detected so far appear to emit a one-off event, there are about 50 FRB sources which emit bursts repeatedly.

Researchers capture first-ever afterglow of huge planetary collision in outer space

Image shows a visualization of the huge, glowing planetary body produced by a planetary collision. In the foreground, fragments of ice and rock fly away from the collision and will later cross in between Earth and the host star which is seen in the background of the image.
Illustration Credit: Mark Garlick

A chance social media post by an eagle-eyed amateur astronomer sparked the discovery of an explosive collision between two giant planets, which crashed into each other in a distant space system 1,800 light years away from planet Earth.

The study, published today in Nature, reports the sighting of two ice giant exoplanets colliding around a sun-like star, creating a blaze of light and plumes of dust. Its findings show the bright heat afterglow and resulting dust cloud, which moved in front of the parent star dimming it over time.

The international team of astronomers was formed after an enthusiast viewed the light curve of the star and noticed something strange. It showed the system doubled in brightness at infrared wavelengths some three years before the star started to fade in visible light.

Co-lead author Dr Matthew Kenworthy, from Leiden University, said: “To be honest, this observation was a complete surprise to me. When we originally shared the visible light curve of this star with other astronomers, we started watching it with a network of other telescopes.

The Good and Bad Uses of Biomass for California

The UC Davis Renewable Anaerobic Energy Digester converts food and yard waste into clean energy.
 Photo Credit: Gregory Urquiaga / UC Davis

As California works to meet climate and air quality goals, a key to the transition will come from biomass, which is renewable organic material from plants and animals.

New research from the University of California, Davis, published in the journal Global Change Biology Bioenergy, examines the good and bad uses of biomass and the best pathways to meet California’s goal of reducing carbon dioxide emissions by 85% of 1990 levels by 2045.

“California is fortunate in having a large biomass resource,” said lead author Peter Freer-Smith, an adjunct professor in the Department of Plant Sciences. “Finding the best use of biomass remains challenging, and this study outlines future scenarios for effective use.”

A New Way to Erase Quantum Computer Errors

While errors are normally hard to spot in quantum devices, researchers have shown that, with careful control, some errors can cause atoms to glow. Researchers used this capability to execute a quantum simulation using an array of atoms and a laser beam, as shown in this simplified artist's concept. The experiment showed that they could discard the glowing, erroneous atoms and make the quantum simulation run more efficiently.
Illustration Credit: Caltech/Lance Hayashida

Quantum computers of the future hold promise in solving all sorts of problems. For example, they could lead to more sustainable materials, new medicines, and even crack the hardest problems in fundamental physics. But compared to classical computers in use today, rudimentary quantum computers are more prone to errors. Wouldn't it be nice if researchers could just take out a special quantum eraser and get rid of the mistakes?

Reporting in the journal Nature, a group of researchers led by Caltech is among the first to demonstrate a type of quantum eraser. The physicists show that they can pinpoint and correct mistakes in quantum computing systems known as "erasure" errors.

"It's normally very hard to detect errors in quantum computers, because just the act of looking for errors causes more to occur," says Adam Shaw, co-lead author of the new study and a graduate student in the laboratory of Manuel Endres, a professor of physics at Caltech. "But we show that with some careful control, we can precisely locate and erase certain errors without consequence, which is where the name erasure comes from."

Commonly Used Herbicide is Harmful to Adolescent Brain Function

UC San Diego Herbert Wertheim School of Public Health and Human Longevity Science researchers measured concentrations of popular herbicides and the insect repellent DEET in urine samples of adolescents living in the agricultural county of Pedro Moncayo, Ecuador to evaluate their impact on the adolescent brain.
Photo Credit: Briana Chronister

Herbicides are the most used class of pesticides worldwide, with uses in agriculture, homes and industry. Exposures to two of the most popular herbicides were associated with worse brain function among adolescents, according to a study led by researchers at the Herbert Wertheim School of Public Health and Human Longevity Science at University of California San Diego.

Jose Ricardo Suarez, M.D., Ph.D., M.P.H., Herbert Wertheim School of Public Health and Human Longevity Science associate professor

In the Oct. 11, 2023 online issue of Environmental Health Perspectives, the researchers reported measuring metabolite concentrations of two commonly used herbicides — glyphosate and 2,4-dichlorophenoxyacetic acid (2,4-D) — and the insect repellent DEET in urine samples collected in 2016 from 519 adolescents, aged 11 to 17, living in the agricultural county of Pedro Moncayo, Ecuador. Researchers also assessed neurobehavioral performance in five areas: attention and inhibitory control, memory and learning, language, visuospatial processing, and social perception.

Doubling Down on Known Protein Families

Shedding light on the diversity of microbial communities by looking at protein function within them.
Illustration Credit: Samantha Trieu/Berkeley Lab

Imagine researchers exploring a dark room with a flashlight, only able to clearly identify what falls within that single beam. When it comes to microbial communities, scientists have historically been unable to see beyond the beam – worse, they didn’t even know how big the room is.

A new study published online October 11, 2023 in Nature highlights the vast array of functional diversity of microbes through a novel approach to better understand microbial communities by looking at protein function within them. The work was led by a team of scientists at the U.S. Department of Energy (DOE) Joint Genome Institute (JGI), a DOE Office of Science User Facility located at Lawrence Berkeley National Laboratory (Berkeley Lab), and collaborators across multiple other research centers around the world.

“We’ve more than doubled the number of protein families known up until now, and identified many novel structure predictions,” said lead author on the paper Georgios Pavlopoulos, now a research director at the Biomedical Sciences Research Center Alexander Fleming. “This was a massive analysis of 1.3 billion proteins with massively parallel computations.”

Removal of magnetic spacecraft contamination within extraterrestrial samples easily carried out

PhD student Ji-In Jung, left, and Assistant Professor Sonia Tikoo examine a collection of lunar samples.
 Photo Credit: Harry Gregory

By demonstrating that spaceflight doesn’t adversely affect the magnetism of moon rocks, Stanford researchers underscore the exciting potential of studying the magnetic histories stored in these samples.

For decades, scientists have pondered the mystery of the moon’s ancient magnetism. Based on analyses of lunar samples, its now-deceased magnetic field may have been active for more than 1.5 billion years – give or take a billion years. Scientists believe it was generated like the Earth’s via a dynamo process, whereby the spinning and churning of conductive liquid metal within a rocky planet’s core generates a magnetic field. However, researchers have grappled with how such a small planetary body could have sustained a long-lived magnetic field. Some have even questioned the legitimacy of return samples that point to the existence of an ancient dynamo, suggesting magnetism may have been acquired via exposure to strong magnetic fields onboard spacecraft during the return mission or from plasmas produced by massive impacts on the moon.

Stanford University scientists have now demonstrated that the magnetism in lunar samples is not adversely altered by the spacecraft journey back to Earth or certain laboratory procedures, disproving one of the two major oppositions to the ancient dynamo theory. The findings, published in Geophysical Research Letters Oct. 11, bode well for research stemming from other sample-return missions from space, since any magnetic contamination acquired during flight or on Earth can likely be easily removed.

A step towards AI-based precision medicine

Mika Gustafsson and David Martínez hope that AI-based models could eventually be used in precision medicine to develop treatments and preventive strategies tailored to the individual. 
Photo Credit: Thor Balkhed

Artificial intelligence, AI, which finds patterns in complex biological data could eventually contribute to the development of individually tailored healthcare. Researchers at LiU have developed an AI-based method applicable to various medical and biological issues. Their models can for instance accurately estimate people’s chronological age and determine whether they have been smokers or not.

There are many factors that can affect which out of all our genes are used at any given point in time. Smoking, dietary habits and environmental pollution are some such factors. This regulation of gene activity can be likened to a power switch determining which genes are switched on or off, without altering the actual genes, and is called epigenetics.

Researchers at Linköping University (LiU) have used data with epigenetic information from more than 75,000 human samples to train a large number of AI neural network models. They hope that such AI-based models could eventually be used in precision medicine to develop treatments and preventive strategies tailored to the individual. Their models are of the autoencoder type, that self-organizes the information and finds interrelation patterns in the large amount of data.

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