Hot on the trail of the causes of rapid ice sheet in­stabil­it­ies in cli­mate his­tory

The re­search ves­sel MARIA S. MERIAN leav­ing the har­bor of St. John’s (Canada). As a par­ti­cipant on Ex­ped­i­tion MSM 39 (2014), Lars Max, along with other re­search­ers, ob­tained the sample ma­ter­ial for this study.
Credit: MARUM – Cen­ter for Mar­ine En­vir­on­mental Sci­ences, Uni­versity of Bre­men; D. Kieke

Extreme cooling events during the last glacial, known as Heinrich Events in the North Atlantic, are a good example of how local processes change the global climate. While the impacts of Heinrich Events on the global glacial environment are well-documented in the scientific literature, their causes are still unclear. In a new study, researchers from Bremen, Kiel, Köln and São Paulo (Brazil) have now shown that an accumulation of heat in the deeper Labrador Sea caused instabilities in the Laurentide Ice Sheet, which covered much of North America at the time. The Heinrich Events were triggered as a result. The researchers demonstrated this by reconstructing past temperatures and salinities in the North Atlantic. Their results have now been published in Nature Communications.

Hein­rich Events or, more ac­cur­ately, Hein­rich Lay­ers, are re­cur­rent con­spicu­ous sed­i­ment lay­ers, usu­ally ten to 15 cen­ti­meters thick, with very coarse rock com­pon­ents that in­ter­rupt the oth­er­wise fine-grained oceanic de­pos­its in the North At­lantic. Dis­covered and de­scribed for the first time in the 1980s by geo­lo­gist Hart­mut Hein­rich, U.S. geo­chem­ist Wally Broecker later of­fi­cially named them Hein­rich Lay­ers, which has be­come a stand­ard term in pa­leocean­o­graphy.

The pres­ence of Hein­rich Lay­ers has been es­tab­lished throughout the North At­lantic, from off Ice­land, south­ward to a line run­ning from New York to North Africa. Such coarse rock debris could only have been trans­por­ted such a great dis­tance from its point of ori­gin in the Hud­son Bay by ice­bergs.

Gaming does not appear harmful to mental health, unless the gamer can't stop

Video gaming: Although today’s research suggests gaming may only be a negative influence only for those who feel compelled to game, rather than all users, there is much more to be learned, according to the Oii research.
Credit: Ella Don on Unsplash

Societies may tremble when a hot new video game is released, but the hours spent playing popular video games do not appear to be damaging players’ mental health, according to the largest-ever survey of nearly 40,000 gamers and their gaming habits, which was conducted over six weeks by a team from Oxford’s Internet Institute. That does not mean, however, that the research did not throw up some concerns – and, the team argues, much more information is needed before tech regulators can really rest easy.

The research, published in the journal Royal Society Open Science, found no ‘causal link’ between gaming and poor mental health – whatever sort of games are being played. But Professor Andrew K. Przybylski, OII Senior Research Fellow, says the research did show a distinct difference in the experience of gamers who play ‘because they want to’ and those who play ‘because they feel they have to’.

He maintains, ‘We found it really does not matter how much gamers played [in terms of their sense of well-being]. It wasn’t the quantity of gaming, but the quality that counted…if they felt they had to play, they felt worse. If they played because they loved it, then the data did not suggest it affected their mental health. It seemed to give them a strong positive feeling.’

"It wasn’t the quantity of gaming, but the quality that counted…if they felt they had to play, they felt worse. If they played because they loved it, then the data did not suggest it affected their mental health"

Professor Andrew K. Przybylski

Towards High-Quality Manganese Oxide Catalysts with Large Surface Areas

The octahedral molecular sieve (OMS-1) is a very powerful manganese oxide-based catalyst, and researchers from Tokyo Tech have found a remarkably simple way to synthesize it. By using a low-crystallinity precursor and a straightforward solid-state transformation method, they managed to produce high-quality OMS-1 nanoparticles. Their unprecedented catalytic performance and durability prove the potential of this novel synthesis approach for developing efficient catalysts and functional materials.

Manganese oxides have received much attention from materials scientists due to their widespread applications including electrodes, catalysts, sensors, supercapacitors, and biomedicine. Further, manganese is widely abundant and has many oxidation states, which allows it to form various interesting crystalline structures.

One such structure is the "todorokite-type manganese oxide octahedral molecular sieve (OMS-1)," a crystal whose unit cells (simplest repeating units of the crystal) consist of three-by-three MnO6 octahedral chains. Though promising as a catalyst, the potential of OMS-1 is limited by two reasons. First, its conventional synthesis methods are complex multi-step crystallization processes involving hydrothermal or reflux treatment. Second, these processes tend to create crystals with a higher particle size and a lower surface area, features detrimental to catalytic performance.

Shape-Memory Polymers

Ilya Starodumov as a member of an international team, is developing a technology for creating "smart" polymers.
Credit: Ilya Safarov

Biocompatible polymers based on a "smart" material poly (ε-caprolactone) that keeps its shape may appear in Russia. An international team of scientists from Russia, Israel, and Japan, including physicists from Ural Federal University, work on the technology of its creation. The research is supported by the Russian Foundation for Basic Research.

Polymeric materials based on poly (ε-caprolactone) are suitable for biomedical purposes: for surgery, cell engineering, regenerative medicine. Such material can be used to make devices for minimally invasive surgery (with minimal incisions), self-tightening surgical sutures, etc. A description of this material was published in The Journal of Physical Chemistry B.

"A special feature of polymers with shape memory is the ability to return to the original shape when the temperature changes. It looks like this: a polymer product with a certain "programmed" shape is made. Then this product is deformed in any manner, for example, stretched or curled, like surgical sutures. When heated to a certain temperature, the memory mechanism in the polymer is activated at the molecular level, and the product restores its original shape," says Ilya Starodumov, Head of the Laboratory of Multiphase Physico-Biological Environment Simulation at UrFU.

Could we eavesdrop on communications that pass through our solar system?

Communications across interstellar distances could take advantage of a star’s ability to focus and magnify communication signals through an effect called gravitational lensing. A signal from—or passing through—a relay probe would bend due to gravity as it passes by the star. The warped space around the object acts somewhat like a lens of a telescope, focusing and magnifying the light. A new study by researchers at Penn State investigated our solar system for communication signals that might be taking advantage of our own sun.
Credit: Dani Zemba / Penn State

Communications across the vastness of interstellar space could be enhanced by taking advantage of a star’s ability to focus and magnify communication signals. A team of graduate students at Penn State is looking for just these sorts of communication signals that might be taking advantage of our own sun if transmissions were passing through our solar system.

A paper describing the technique — explored as part of a graduate course at Penn State covering the Search for Extraterrestrial Intelligence (SETI) — has been accepted for publication in the Astronomical Journal and is available on the preprint server arXiv.

Massive objects like stars and black holes cause light to bend as it passes by due to the object’s gravitational pull, according to Einstein’s Theory of General Relativity. The warped space around the object acts somewhat like a lens of a telescope, focusing and magnifying the light — an effect called gravitational lensing.

Underwater cave fossil site gains state protections

A reconstruction of the South Australian cave site which has been heritage listed due to its abundance of megafauna fossils.
Image by Peter Schouten.

A team of researchers and cave divers have successfully lobbied for the protection of a unique fossil site in South Australia, which could pave the way for the future preservation of other important paleontological sites around Australia.

The underwater cave site known as the Green Waterhole in the Mount Gambier region contains the only known extensive underwater vertebrate fossil deposits in Australia, has been listed on the South Australia State Heritage Register.

The unique freshwater depositional environment has ensured the preservation of extinct species of megafauna such as marsupial lions, short-faced kangaroos, and carnivorous kangaroos, with several additional species new to science recovered and awaiting description.

How Omicron dodges the immune system

Meriem Bekliz, first author, with a plaque-reduction neutralization assay used to determine the neutralizing capacity of antibodies.
Credit: HUG-UNIGE.

By comparing the neutralization capacity induced by the different variants of SARS-CoV-2, a team from the UNIGE and the HUG reveals the exceptional capacity of Omicron to evade our immunity.

The current wave of COVID-19 highlights a particularly high risk of reinfection by the Omicron variant of SARS-CoV-2. Why is this? A team from the Centre for Emerging Viral Diseases of the University of Geneva (UNIGE) and of the Geneva University Hospital (HUG) analyzed the antibody neutralization capacity of 120 people infected with the original SARS-CoV-2 strain, or with one of its Alpha, Beta, Gamma, Delta, Zeta or Omicron (sub-variant BA.1) variants. And unlike its predecessors, Omicron appears to be able to evade the antibodies generated by all other variants. In vaccinated individuals, while the neutralization capacity is also reduced, it remains far superior to natural immunity alone. This could explain why Omicron is responsible for a net increase in vaccine break-through infections, but not in hospitalizations. These results can be read in the journal Nature Communications.

Study reveals why highly infectious cholera variant mysteriously died out

Water sample in test tube
Credit: Photo by Martin Lopez

A new study reveals why a highly infectious variant of the cholera bug, which caused large disease outbreaks in the early 1990s, did not cause the eighth cholera pandemic as feared – but instead unexpectedly disappeared.

The study analyzed samples of O139 Vibrio cholerae, a variant of the bacteria that causes cholera, and discovered significant changes in its genome over time that led to its unexpected decline.

These genetic changes resulted in a gradual loss of antimicrobial resistance (AMR), and a change in the types of toxin produced by the cholera bug. In combination, these changes are likely to account for O139’s failure to seed the eighth cholera pandemic.

The cholera bug is not currently monitored on a regular basis. Scientists say continuous monitoring of the genes underlying AMR and toxin production is key to keeping ahead of the cholera bug as it evolves. In particular, this will help to plan changes to vaccines and appropriate public health responses to prevent future cholera outbreaks.

The O139 variant of Vibrio cholerae was first detected in India in 1992. It quickly became dominant over the existing O1 variant and caused huge disease outbreaks in India and Southern Bangladesh.

Researchers expand understanding of vortex spread in superfluids

An illustration of a vortex tangle.
Credit: Wei Guo/FAMU-FSU College of Engineering

An international team of scientists featuring Florida State University researchers has developed a model that predicts the spread of vortices in so-called superfluids, work that provides new insight into the physics that govern turbulence in quantum fluid systems such as superfluid neutron stars.

In a paper published in Physical Review Letters, the researchers created a model that describes the spread and speed of tornado-like vortex tubes in superfluids. Vortex tubes are a key ingredient of turbulence, which is widely studied in classical physics. The motion of vortex tubes is relevant in a wide range of scenarios, such as the formation of hurricanes, the airborne transmission of viruses and the chemical mixing in star formation. But it is poorly understood in quantum fluids.

This work expands on a previous study that reported experimental results obtained in superfluid helium-4 within a narrow temperature range. Superfluids are liquids that can flow without resistance, and therefore without a loss of kinetic energy. When they are stirred, they form vortices that rotate indefinitely.

“By validating this model and showing that it describes the movement of vortices at a wide range of temperatures, we are confirming a universal rule for this phenomenon,” said Wei Guo, an associate professor of mechanical engineering at the FAMU-FSU College of Engineering. “This discovery may aid the development of advanced theoretical models of quantum fluid turbulence.”

COVID-19 virus spike protein flexibility improved by human cell's own modifications

University of Illinois researchers created atomic-level models of the spike protein that plays a key role in COVID-19 infection and immunity, revealing how the protein bends and moves as it seeks to engage receptors. 
Credit: Tianle Chen

When the coronavirus causing COVID-19 infects human cells, the cell’s protein-processing machinery makes modifications to the spike protein that render it more flexible and mobile, which could increase its ability to infect other cells and to evade antibodies, a new study from the University of Illinois Urbana-Champaign found.

The researchers created an atomic-level computational model of the spike protein and ran multiple simulations to examine the protein’s dynamics and how the cell’s modifications affected those dynamics. This is the first study to present such a detailed picture of the protein that plays a key role in COVID-19 infection and immunity, the researchers said.

Biochemistry professor Emad Tajkhorshid, postdoctoral researcher Karan Kapoor and graduate student Tianle Chen published their findings in the journal PNAS.

“The dynamics of a spike are very important – how much it moves and how flexible it is to search for and bind to receptors on the host cell,” said Tajkhorshid, who also is a member of the Beckman Institute for Advanced Science and Technology. “In order to have a realistic representation, you have to look at the protein at the atomic level. We hope that the results of our simulations can be used for developing new treatments. Instead of using one static structure of the protein to search for drug-binding pockets, we want to reproduce its movements and use all of the relevant shapes it adopts to provide a more complete platform for screening drug candidates instead of just one structure.”