Arctic has entered a new era of extreme weather

Cassiope tetragona killed by a rain-on-snow event.
Photo Credit: R Treharne

Extreme weather events have become significantly more common in the Arctic over recent decades, posing a threat to vital polar ecosystems, according to new research by an international team of scientists. 

Key Takeaways:

• New research by an international team of scientists has found that Arctic regions are facing unprecedented climate conditions 

• Study has found that extreme weather events have become more common over the past 30 years, threatening plants and animals 

• Findings show hotspots for extreme weather events are Western Scandinavia, the Canadian Arctic Archipelago and Central Siberia 

• Damage from extreme weather can also affect the livelihoods of Arctic people such as reindeer herders and may also harm the ability of the Arctic to absorb carbon and slow climate change. 

Extreme weather events have become significantly more common in the Arctic over recent decades, posing a threat to vital polar ecosystems, according to new research by an international team of scientists. 

Lipid have their own VIP drivers

Image Credit: Scientific Frontline / AI generated

In addition to providing energy, lipids are also essential building blocks of our cell membranes. However, despite their importance, they remain poorly understood. A team from the University of Geneva (UNIGE) has revealed for the first time the secrets of their transport within cells. Each lipid uses a limited number of proteins to move from its place of production to its place of action. The team has also compiled an inventory of the proteins involved in the transport of hundreds of lipids. These findings, published in the journal Nature, provide a better picture of the functioning of our cells, as well as of many genetic and metabolic disorders, such as diabetes and Alzheimer's disease. 

Lipids are often described as our organism's energy reserve, but this definition masks the diversity of their functions. They enable the absorption of some vitamins, are converted into hormones, and assemble into complex membranes. Their dysfunction is also linked to serious diseases such as Alzheimer's, where the lipid composition of nerve cells (neurons and astrocytes) is altered. 

Beyond gene scissors: New CRISPR mechanism discovered

Cryo-electron microscope structure of the nuclease Cas12a3 cleaving the tail of a transfer RNA (tRNA).
 Image Credit: Biao Yuan / Helmholtz Zentrum für Infektionsforschung HZI

The CRISPR “gene scissors” have become an important basis for genome-editing technologies in many fields, ranging from biology and medicine to agriculture and industry. A team from the Helmholtz Institute for RNA-based Infection Research (HIRI) in Würzburg has now demonstrated that these CRISPR-Cas systems are even more versatile than previously thought. 

In cooperation with the Helmholtz Centre for Infection Research (HZI) in Braunschweig and Utah State University (USU) in Logan (USA), the scientists have discovered a novel CRISPR defense mechanism: Unlike known nucleases, Cas12a3 specifically destroys transfer ribonucleic acids (tRNA) that are vital for protein production to shut down infected cells. The team published its findings today in the journal Nature. 

Bacteria contain a wide variety of mechanisms to fend off invaders like viruses. One of these strategies involves cleaving transferring ribonucleic acids (tRNA), which are present in all cells and play a fundamental role in the translation of messenger RNA (mRNA) into essential proteins. Their inactivation limits protein production, causing the infected cell to go dormant. As a result, the attacker cannot continue to replicate and spread within the bacterial population. 

Pills that communicate from the stomach could improve medication adherence

Two photos show the gelatin-coated capsules (left) and the capsule without the coating (right). The capsule can be broken down and absorbed by the body.
Photo Credit: Courtesy of the researchers
(CC BY-NC-ND 4.0)

In an advance that could help ensure people are taking their medication on schedule, MIT engineers have designed a pill that can report when it has been swallowed.

The new reporting system, which can be incorporated into existing pill capsules, contains a biodegradable radio frequency antenna. After it sends out the signal that the pill has been consumed, most components break down in the stomach while a tiny RF chip passes out of the body through the digestive tract.

This type of system could be useful for monitoring transplant patients who need to take immunosuppressive drugs, or people with infections such as HIV or TB, who need treatment for an extended period of time, the researchers say.

Cosmic Lens Reveals Hyperactive Cradle of Future Galaxy Cluster

The galaxy cluster lens J0846 in optical light (bottom right), the ALMA view of dust-enshrouded, star-forming galaxies strongly lensed into bright arcs (top right), and a composite view (left) revealing at least 11 dusty galaxies in a compact protocluster core more than 11 billion light-years away, magnified by the foreground cluster’s gravity.
Image Credit: NSF/AUI/NSF NRAO/B. Saxton; NSF/NOIRLab

Galaxy clusters are formed by a dense packing of many galaxies, making them the most massive structures in the Universe. Their progenitors, protoclusters, show these galaxies in their infancy, offering a window to study how they all formed. This early “settlement” of galaxies will eventually evolve into a sprawling metropolis by the present day. Astronomers using the U.S. National Science Foundation Very Large Array (NSF VLA) and the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered a rare protocluster that was exceptionally bright, all when the Universe was 11 billion years younger. The system, called PJ0846+15 (J0846), is the first strongly lensed protocluster core discovered, revealing how some of the most massive galaxy clusters in the present-day Universe began their lives.

Researchers uncover molecular roots of fibrosis or tissue scarring in inflammatory bowel disease

Spatial mapping of intestinal tissue from patients with Crohn's disease or ulcerative colitis (shown here) allowed the researchers to characterize the cell types (shown as different colored dots) involved in fibrosis. In this image, inflammation-associated fibroblasts that deposit scar tissue roughly align with the cellular niche displayed in royal blue.
Image Credit: Courtesy of the Xavier lab

When inflammation in the body goes unchecked, it can cause fibrosis, or tissue scarring that may lead to organ dysfunction or even failure. This can happen in conditions such as inflammatory bowel diseases (ulcerative colitis and Crohn’s disease), chronic viral infections, interstitial lung fibrosis, chronic autoimmune skin diseases such as scleroderma, and scars associated with heart disease. Patients have few options for treating fibrosis, but new research points to a molecular pathway that could open the door to future treatment possibilities.

In earlier work, a team led by researchers at the Broad Institute and Mass General Brigham discovered a key cell type underlying fibrosis in inflammatory bowel disease (IBD). Now, in a new study in Nature, the team has characterized the crosstalk between this and other types of cells that leads to fibrosis. Their work also points to a molecule, GLIS3, that regulates this cell-to-cell communication and hadn’t been linked to IBD before. The findings suggest that interrupting this cellular pathway could one day help prevent or reduce fibrosis in patients with IBD or other diseases marked by chronic inflammation such as lung disease. 

Natural physical networks are continuous, three-dimensional objects, like the small mathematical model displayed here. Researchers have found that physical networks in living systems follow rules borrowed from string theory, a theoretical physics framework.
Illustration Credit: Xiangyi Meng/RPI

For more than a century, scientists have wondered why physical structures like blood vessels, neurons, tree branches, and other biological networks look the way they do. The prevailing theory held that nature simply builds these systems as efficiently as possible, minimizing the amount of material needed. But in the past, when researchers tested these networks against traditional mathematical optimization theories, the predictions consistently fell short. 

The problem, it turns out, was that scientists were thinking in one dimension when they should have been thinking in three. "We were treating these structures like wire diagrams," Rensselaer Polytechnic Institute (RPI) physicist Xiangyi Meng, Ph.D., explains. "But they're not thin wires, they're three-dimensional physical objects with surfaces that must connect smoothly." 

Naturally occurring “space weather station” elucidates new way to study habitability of planets orbiting M dwarf stars

Artist's renditions of the space weather around M dwarf TIC 141146667. The torus of ionized gas is sculpted by the star's magnetic field and rotation, with two pinched, dense clumps present on opposing sides of the star.
Illustrations Credit: Navid Marvi, courtesy Carnegie Science.

How does a star affect the makeup of its planets? And what does this mean for the habitability of distant worlds? Carnegie’s Luke Bouma is exploring a new way to probe this critical question—using naturally occurring space weather stations that orbit at least 10 percent of M dwarf stars during their early lives. He is presenting his work at the American Astronomical Society meeting this week. 

We know that most M dwarf stars—which are smaller, cooler, and dimmer than our own Sun—host at least one Earth-sized rocky planet. Most of them are inhospitable—too hot for liquid water or atmospheres, or hit with frequent stellar flares and intense radiation. But they could still prove to be interesting laboratories for understanding the many ways that stars shape the surroundings in which their planets exist.

“Stars influence their planets. That’s obvious. They do so both through light, which we’re great at observing, and through particles—or space weather—like solar winds and magnetic storms, which are more challenging to study at great distances,” Bouma explained. “And that’s very frustrating, because we know in our own Solar System that particles can sometimes be more important for what happens to planets.” 

But astronomers can’t set up a space weather station around a distant star. 

The Mechanical Ratchet: A New Mechanism of Cell Division Uncovered

A zebrafish embryo during the first cell division cycle, with the structural protein actin labelled, which marks the cell boundary and ingressing furrow. The image shows a time course from dark orange (before ingression) to brighter orange and finally white as ingression proceeds.
Image Credit: © Alison Kickuth, Brugués Lab

Cell division is an essential process for all life on earth, yet the exact mechanisms by which cells divide during early embryonic development have remained elusive – particularly for egg-laying species. Scientists from the Brugués group at the Cluster of Excellence Physics of Life (PoL) at Dresden University of Technology have revealed a novel mechanism that explains how early embryonic cells may divide without forming a complete contractile ring, traditionally seen as essential for this process. The findings, published in Nature, challenge the long-standing textbook view of cell division, revealing how parts of the cytoskeleton, and material properties of the cell interior (or cytoplasm) cooperate to drive division through a ‘ratchet’ mechanism.     

We finally know how the most common types of planets are created

Astronomers have now witnessed four baby planets in the V1298 Tau system in the process of becoming super-Earths and sub-Neptunes.
Image Credit: Astrobiology Center, NINS  

Thanks to the discovery of thousands of exoplanets to date, we know that planets bigger than Earth but smaller than Neptune orbit most stars. Oddly, our sun lacks such a planet. That’s been a source of frustration for planetary scientists, who can’t study them in as much detail as they’d like, leaving one big question: How did these planets form? 

Now we know the answer. 

An international team of astrophysicists from UCLA and elsewhere has witnessed four baby planets in the V1298 Tau system in the process of becoming super-Earths and sub-Neptunes. The findings are published in the journal Nature. 

“I’m reminded of the famous ‘Lucy’ fossil, one of our hominid ancestors that lived 3 million years ago and was one of the ‘missing links’ between apes and humans,” said UCLA professor of physics and astronomy and second author Erik Petigura. “V1298 Tau is a critical link between the star- and planet-forming nebulae we see all over the sky, and the mature planetary systems that we have now discovered by the thousands.”