Rensselaer Physics Researcher to Advance Potentially Revolutionary Experiment

 Ethan Brown is an associate professor of physics, applied physics, and astronomy
Credit: Rensselaer Polytechnic Institute

It is believed to be exceedingly rare and slow, but if it actually exists, it would redefine the laws of physics: it’s called neutrinoless double beta decay (NDBD).

Rensselaer Polytechnic Institute’s Ethan Brown, associate professor of physics, applied physics, and astronomy, has received a $285,000 grant from the Department of Energy to contribute to the nEXO experiment to prove that NDBD exists. The nEXO experiment involves the collaboration of dozens of scientists and technologists from institutions around the globe.

Double beta decay is when two neutrons simultaneously decay into two protons and emit two electrons and two electron antineutrinos in the process. With neutrinoless double beta decay, only the electrons and protons are thought to be emitted. This contradicts the accepted laws of physics, in which all particles have a complementary antiparticle.

However, almost 100 years ago, physicist Ettore Majorana hypothesized that this did not necessarily apply to particles without charge, such as the neutrino. His hypothesis is yet to be proven, but it would offer a new understanding of the universe. Since the universe is composed mostly of matter, NBDB would explain why it is not equal parts matter and antimatter.

Vets and pets to reap benefits from new drug to treat common infection

Australia’s 29 million pets look set to benefit from a more effective treatment for Giardia, a common intestinal infection in dogs and cats, thanks to a collaboration between academia and industry.

Pharmaceutical scientists from five Australian universities are partnering with veterinary pharmaceutical company Neoculi Pty Ltd to develop a new drug to treat Giardia, which affects at least 15 per cent of dogs, particularly puppies, and approximately 12 per cent of cats.

Existing treatments on the market are ineffective and have significant drawbacks, according to University of South Australia pharmaceutical scientist Professor Sanjay Garg, one of the key collaborators on the three-year project, led by the University of Newcastle.

Professor Garg says current drugs have limited effectiveness due to parasitic resistance, require multiple treatments and have toxic side effects.

“The drug we are developing is safe and effective in one single dose. We are aiming to produce a palatable formulation that pets will take without any resistance.” Prof Garg says. “It should be available within three years.”

Divorce is more common in albatross couples with shy males

A wandering albatross displaying to potential mates. Both males and females perform elaborate mating dances before bonding with a partner.
Image credit: Samantha Patrick, University of Liverpool

The wandering albatross is the poster bird for avian monogamy. The graceful glider is known to mate for life, partnering up with the same bird to breed, season after season, between long flights at sea.

But on rare occasions, an albatross pair will “divorce” — a term ornithologists use for instances when one partner leaves the pair for another mate while the other partner remains in the flock. Divorce rates vary widely across the avian world, and the divorce rate for wandering albatrosses is relatively low.

Nevertheless, the giant drifters can split up. Scientists at MIT and the Woods Hole Oceanographic Institution (WHOI) have found that, at least for one particular population of wandering albatross, whether a pair will divorce boils down to one important factor: personality.

In a study appearing today in the journal Biology Letters, the team reports that an albatross couple’s chance of divorce is highly influenced by the male partner’s “boldness.” The bolder and more aggressive the male, the more likely the pair is to stay together. The shyer the male, the higher the chance that the pair will divorce.

Are we missing a crucial component of sea-level rise?

Map of Antarctica.
Image credit: Wikimedia Commons

Across Antarctica, some parts of the base of the ice sheet are frozen, while others are thawed. Scientists show that if some currently frozen areas were also to thaw, it could increase ice loss from glaciers that are not currently major sea-level contributors.

Recent efforts using computational modeling to understand how melting ice in Antarctica will impact the planet’s oceans have focused on ice-sheet geometry, fracture, and surface melting – processes that could potentially trigger or accelerate ice-sheet mass loss. Now, researchers have identified an additional process that could have a similarly significant effect on the ice sheet’s future: thawing of the bed, known as basal thaw, at the interface of the land and the miles-thick ice sheet above it.

The new study identifies areas that are not currently losing large amounts of mass but could be poised to match some of the largest contributors to sea-level rise – such as Thwaites Glacier – if they thawed. Antarctica is roughly the size of the United States, and the susceptible regions comprise an area greater than California. The research was published Sept. 14 in Nature Communications.

“You can’t necessarily assume that everywhere that’s currently frozen will stay frozen,” said senior study author Dustin Schroeder, an associate professor of geophysics at the Stanford Doerr School of Sustainability. “These regions may be under-appreciated potential contributors.”

Crime in the realm of bacteria

Christine Kaimer (left) and Susanne Thiery have investigated how soil bacteria fight each other.
Credit: RUB, Marquard

Who would have thought of bacteria: they can sneak up other microorganisms to kill and eat them up.

Bacteria have a variety of survival strategies to provide sufficient food in their densely populated habitats. Certain types of bacteria kill microorganisms of another type, decompose the cells and absorb them as nutrients. How this works is usually unknown. A research team on the biology of microorganisms around Dr. Christine Kaimer examined these processes in more detail. Together with colleagues from the USA, the researchers at the Ruhr University Bochum (RUB) report in the journal Cell Reports on 13. September 2022.

Stop at contact

So far, little is known about the relationship between robbers and prey in the realm of bacteria. However, researchers suspect that bacterial predators can greatly change the composition of a microbiome and thus influence the ecology of their habitat. To learn more about bacterial predator-prey relationships, Christine Kaimer's team examined the predator bacterium Myxococcus xanthus, that often occurs in the ground. It has recently become known that M. xanthus kills his prey cell in direct cell-cell contact: the predator approaches a prey cell, stops when a contact is made, and then causes cell death and decomposition within a few minutes. The researchers examined the molecular mechanisms of this process in more detail.

Decarbonizing the energy system by 2050 could save trillions

Achieving a net zero carbon energy system by around 2050 is possible and profitable
Credit: Appolinary Kalashnikova

Transitioning to a decarbonized energy system by around 2050 is expected to save the world at least $12 trillion, compared to continuing our current levels of fossil fuel use, according to a peer-reviewed study by Oxford University researchers, published in the journal Joule.

The research shows a win-win-win scenario, in which rapidly transitioning to clean energy results in lower energy system costs than a fossil fuel system, while providing more energy to the global economy, and expanding energy access to more people internationally.

The study’s ‘Fast Transition’ scenario, shows a realistic possible future for a fossil-free energy system by around 2050, providing 55% more energy services globally than today, by ramping up solar, wind, batteries, electric vehicles, and clean fuels such as green hydrogen (made from renewable electricity).

Lead author Dr Rupert Way, postdoctoral researcher at the Smith School of Enterprise and the Environment, says, ‘Past models predicting high costs for transitioning to zero carbon energy have deterred companies from investing, and made governments nervous about setting policies that will accelerate the energy transition and cut reliance on fossil fuels. But clean energy costs have fallen sharply over the last decade, much faster than those models expected.

‘Our latest research shows scaling-up key green technologies will continue to drive their costs down, and the faster we go, the more we will save. Accelerating the transition to renewable energy is now the best bet, not just for the planet, but for energy costs too.’

How the brain focuses on what’s in mind

Remembering directions someone just gave you is an example of working memory. In a new study, MIT researchers show that the brain's focus on the contents of what its holding in mind derives from bursts of gamma frequency rhythms in the front of the brain.
Photo credit: George Pak

Working memory, that handy ability to consciously hold and manipulate new information in mind, takes work. In particular, participating neurons in the prefrontal cortex have to work together in synchrony to focus our thoughts, whether we’re remembering a set of directions or tonight’s menu specials. A new study by researchers based at The Picower Institute for Learning and Memory at MIT shows how that focus emerges.

The key measure in the study in Scientific Reports is the variability of the neurons’ activity. Scientists widely agree that less variability activity means more-focused attunement to the task. Measures of that variability have indeed shown that it decreases when humans and animals focus during working memory games in the lab.

In several studies between 2016 and 2018, lead author Mikael Lundqvist and co-senior author Earl K. Miller showed through direct measurements of hundreds of neurons and rigorous modeling that bursts of gamma frequency rhythms in the prefrontal cortex coordinate neural representation of the information held in mind. The information representation can be measured in the synchronized spiking of populations of individual neurons. Bursts of beta frequency rhythms, meanwhile, implement the brain’s manipulation of that information. The theory, which Miller dubbed “Working Memory 2.0” challenged a long-held orthodoxy that neurons maintain working memory information through steady, persistent activity. Proponents of that older model, which emerged from averaged measurements made in relatively few neurons, used computer-based modeling of brain activity to argue that reduced variability cannot emerge from intermittent bursts of rhythmic activity.

New method for comparing neural networks exposes how artificial intelligence works

Researchers at Los Alamos are looking at new ways to compare neural networks. This image was created with an artificial intelligence software called Stable Diffusion, using the prompt “Peeking into the black box of neural networks.”
Source: Los Alamos National Laboratory

A team at Los Alamos National Laboratory has developed a novel approach for comparing neural networks that looks within the “black box” of artificial intelligence to help researchers understand neural network behavior. Neural networks recognize patterns in datasets; they are used everywhere in society, in applications such as virtual assistants, facial recognition systems and self-driving cars.

“The artificial intelligence research community doesn’t necessarily have a complete understanding of what neural networks are doing; they give us good results, but we don’t know how or why,” said Haydn Jones, a researcher in the Advanced Research in Cyber Systems group at Los Alamos. “Our new method does a better job of comparing neural networks, which is a crucial step toward better understanding the mathematics behind AI.”

Jones is the lead author of the paper “If You’ve Trained One You’ve Trained Them All: Inter-Architecture Similarity Increases With Robustness,” which was presented recently at the Conference on Uncertainty in Artificial Intelligence. In addition to studying network similarity, the paper is a crucial step toward characterizing the behavior of robust neural networks.

These pesticides may increase cancer risk in children

Julia Heck, associate research professor of epidemiology
in the UCLA Fielding School of Public Health.
Source: UCLA

Past research has shown that pesticide exposure increases the risk of cancer. Now, UCLA-led research has exposed which specific pesticides increase the risk of retinoblastoma — a rare eye tumor — in children.

The study, published in the August International Journal of Hygiene and Environmental Health, found that children prenatally exposed to the chemicals acephate and bromacil had an increased risk of developing unilateral retinoblastoma, or cancer in one eye, and that exposure to pymetrozine and kresoxim-methyl increased the risk of all types of retinoblastoma.

“What’s important is looking at specific bad actors and identifying them,” said Julia Heck, an adjunct associate professor in the department of epidemiology at the UCLA Fielding School of Public Health, who studies environmental causes of childhood cancers.

Identifying specific pesticides correlated with cancer is the first step toward banning or replacing them with less harmful options.

The researchers studied land use data and pesticide use reports — which provide information on where, when and in what quantity the chemicals are applied — to determine locations of possible pesticide exposure. They considered 132 pesticides that are associated with cancer.

They compared children with retinoblastoma to random children with California birth certificates and found that those with cancer were more likely to have been born in neighborhoods near applications of specific pesticides.

The gene to which we owe our big brain

A section of a brain organoid made from stem cells of a human. In magenta are actively proliferating brain stem cells, in yellow a subset of brain stem cells.
Photo Credit: Jan Fischer

ARHGAP11B - this complex name is given to a gene that is unique to humans and plays an essential role in the development of the neocortex. The neocortex is the part of the brain to which we owe our high mental abilities. A team of researchers from the German Primate Center (DPZ) - Leibniz Institute for Primate Research in Göttingen, the Max Planck Institute for Molecular Cell Biology and Genetics (MPI-CBG) in Dresden, and the Hector Institute for Translational Brain Research (HITBR) in Mannheim has investigated the importance of ARHGAP11B in neocortex development during human evolution. 

To do this, the team introduced for the first time a gene that exists only in humans into laboratory-grown brain organoids from our closest living relatives, chimpanzees. In the chimpanzee brain organoid, the ARHGAP11B gene led to an increase in brain stem cells relevant to brain growth and an increase in those neurons that play a critical role in the extraordinary mental abilities of humans. If, on the other hand, the ARHGAP11B gene was switched off in human brain organoids, the quantity of these brain stem cells fell to the level of a chimpanzee. Thus, the research team was able to show that the ARGHAP11B gene played a crucial role in the evolution of the brain from our ancestors to modern humans.