Measuring neutrons to reduce nuclear waste

Simulation of neutron star collision.
Detections of gravitational waves from merging neutron stars tipped off researchers here on Earth that it should be possible to predict how neutrons interact with atomic nuclei.
Image Credit: NASA's Goddard Space Flight Center/CI Lab
(CC BY-ND 4.0 DEED)

Nuclear power is considered one of the ways to reduce dependence on fossil fuels, but how to deal with nuclear waste products is among the issues surrounding it. Radioactive waste products can be turned into more stable elements, but this process is not yet viable at scale. New research led by physicists from the University of Tokyo reveals a method to more accurately measure, predict and model a key part of the process to make nuclear waste more stable. This could lead to improved nuclear waste treatment facilities and also to new theories about how some heavier elements in the universe came to be.

The very word “nuclear” can be a bit of a trigger for some people, understandably so in Japan, where the atomic bomb and Fukushima disaster are some of the pivotal moments in its modern history. Yet, given the relative scarcity of suitable space in Japan for renewable forms of energy like solar or wind, nuclear power is considered to be a critical part of the effort to decarbonize the energy sector. Because of this, researchers are hard at work trying to improve safety, efficiency and other matters relating to nuclear power. Associate Professor Nobuaki Imai from the Center for Nuclear Study at the University of Tokyo and his colleagues think they can contribute to improving a key aspect of nuclear power, the processing of waste.

Innovative materials to combat bacteria

Three bacteria from the ESKAPE group: Staphylococcus aureus (yellow), Pseudomonas aeruginosa (short thick blue rods) and Escherichia coli (long blue rods).
Image Credit: © UNIGE

While crucial to biotechnology, bacteria can also cause severe disease, exacerbated by their increasing resistance to antibiotics. This duality between economic benefits and infectious risks underlines the importance of finding ways to control their development. A team at the University of Geneva (UNIGE) is currently developing a new generation of bactericidal alloys, with a wide range of industrial applications. They could be used to treat the contact surfaces responsible for their transmission. The project, which is supported by Innosuisse, will take 18 months to complete.

Resistance to antimicrobial drugs - such as antibiotics and antivirals - is a global public health issue. According to the World Health Organization (WHO), it is currently responsible for 700,000 deaths a year worldwide. If no action is taken, the number of deaths will rise to 10 million a year by 2050, with dramatic consequences for public health and the economy.

To promote and guide research in this field, the WHO has published a list of pathogens that should be targeted as a matter of priority, because they are particularly threatening to human health. The list includes Staphylococcus aureus and E. coli bacteria, which are associated with the most common hospital-acquired infections, as well as salmonella. Contaminated contact surfaces (utensils, handles, stair railings) play a fundamental role in their transmission.

Widely used AI tool for early sepsis detection may be cribbing doctors’ suspicions

Image Credit: Scientific Frontline

When using only data collected before patients with sepsis received treatments or medical tests, the model’s accuracy was no better than a coin toss

Proprietary artificial intelligence software designed to be an early warning system for sepsis can’t differentiate high and low risk patients before they receive treatments, according to a new study from the University of Michigan.

The tool, named the Epic Sepsis Model, is part of Epic’s electronic medical record software, which serves 54% of patients in the United States and 2.5% of patients internationally, according to a statement from the company’s CEO reported by the Wisconsin State Journal. It automatically generates sepsis risk estimates in the records of hospitalized patients every 20 minutes, which clinicians hope can allow them to detect when a patient might get sepsis before things go bad.

“Sepsis has all these vague symptoms, so when a patient shows up with an infection, it can be really hard to know who can be sent home with some antibiotics and who might need to stay in the intensive care unit. We still miss a lot of patients with sepsis,” said Tom Valley, associate professor in pulmonary and critical care medicine, ICU clinician and co-author of the study published recently in the New England Journal of Medicine AI.

Researchers Discover That a Rare Fat Molecule Helps Drive Cell Death

Illustration of a diPUFA phospholipid, a type of lipid with two polyunsaturated fatty acyl tails, breaking through a cell's outer lipid layer as the cell dies. New research has shown that diPUFA phospholipids are a key driver of a form of cell death known as ferroptosis.
Illustration Credit: Nicoletta Barolini

The discovery that a lipid helps induce cell death could improve treatments for certain cancers and neurodegenerative diseases.

Columbia researchers have found that a rare type of lipid is a key driver of ferroptosis, a form of cell death discovered by Columbia Professor Brent Stockwell.

The findings provide new detail on how cells die during ferroptosis and could improve understanding of how to stop ferroptosis in contexts where it is harmfully occurring—in neurodegenerative diseases, for example—or induce it in contexts where it could be useful, such as using it to kill dangerous cancer cells.

First-Ever Atomic Freeze-Frame of Liquid Water

Scientists used a synchronized attosecond X-ray pulse pair (pictured pink and green here) from an X-ray free electron laser to study the energetic response of electrons (gold) in liquid water on attosecond timescale, while the hydrogen (white) and oxygen (red) atoms are ‘frozen’ in time. 
Illustration Credit: Nathan Johnson | Pacific Northwest National Laboratory

In an experiment akin to stop-motion photography, scientists have isolated the energetic movement of an electron while “freezing” the motion of the much larger atom it orbits in a sample of liquid water.

The findings, reported today in the journal Science, provide a new window into the electronic structure of molecules in the liquid phase on a timescale previously unattainable with X-rays. The new technique reveals the immediate electronic response when a target is hit with an X-ray, an important step in understanding the effects of radiation exposure on objects and people.

“The chemical reactions induced by radiation that we want to study are the result of the electronic response of the target that happens on the attosecond timescale,” said Linda Young, a senior author of the research and Distinguished Fellow at Argonne National Laboratory. “Until now radiation chemists could only resolve events at the picosecond timescale, a million times slower than an attosecond. It’s kind of like saying ‘I was born and then I died.’ You’d like to know what happens in between. That’s what we are now able to do.”

A multi-institutional group of scientists from several Department of Energy national laboratories and universities in the U.S. and Germany combined experiments and theory to reveal in real-time the consequences when ionizing radiation from an X-ray source hits matter.

The brain is 'programmed' for learning from people we like

Image Credit: Gemini Advance AI

Our brains are "programmed" to learn more from people we like – and less from those we dislike. This has been shown by researchers in cognitive neuroscience in a series of experiments.

Memory serves a vital function, enabling us to learn from new experiences and update existing knowledge. We learn both from individual experiences and from connecting them to draw new conclusions about the world. This way, we can make inferences about things that we don't necessarily have direct experience of. This is called memory integration and makes learning quick and flexible.

Inês Bramão, associate professor of psychology at Lund University, provides an example of memory integration: Say you're walking in a park. You see a man with a dog. A few hours later, you see the dog in the city with a woman. Your brain quickly makes the connection that the man and woman are a couple even though you have never seen them together. 

“Making such inferences is adaptive and helpful. But of course, there's a risk that our brain draws incorrect conclusions or remembers selectively”, says Inês Bramão.

Electrons screen against conductivity-killer in organic semiconductors

Muhamed Duhandžić, doctoral candidate and study author, writes the equations he and Zlatan Akšamija (left) derived to describe the physics happening inside the doped polymer.
Photo Credit: Harriet Richardson/University of Utah

California’s Silicon Valley and Utah’s Silicon Slopes are named for the element most associated with semiconductors, the backbone of the computer revolution. Anything computerized or electronic depends on semiconductors, a substance with properties that conduct electrical current under certain conditions. Traditional semiconductors are made from inorganic materials—like silicon—that require vast amounts of water and energy to produce.

For years, scientists have tried to make environmentally friendly alternatives using organic materials, such as polymers. Polymers are formed by linking small molecules together to make long chains. The polymerization process avoids many of the energy-intensive steps required in traditional semiconductor manufacturing and uses far less water and fewer gasses and chemicals. They’re also cheap to make and would enable flexible electronics, wearable sensors and biocompatible devices that could be introduced inside the body. The problem is that their conductivity, while good, is not as high as their inorganic counterparts.

All electronic materials require doping, a method of infusing molecules into semiconductors to boost conductivity. Scientists use molecules, called dopants, to define the conductive parts of electrical circuits. Doping in organic materials has vexed scientists because of a lack of consistency—sometimes dopants improve conductivity while other times they make it worse.  In a new study, researchers from the University of Utah and University of Massachusetts Amherst have uncovered the physics that drive dopant and polymer interactions that explain the inconsistent conductivity issue.

The ties that bind

The soils in many iconic Australian landscapes, like the outback and deserts, are colored red by an abundant mineral known as goethite. This mineral tends to lock away trace metals over time, according to research from Washington University in St. Louis
Photo Credit: Nathan March

Trace metals are nutrient elements, like zinc, that animals and plants need in small amounts to function properly. Animals generally get trace metals in their diets or through environmental exposures, while plants take their trace minerals up from soil. If we get too little, we may experience a deficiency, but the opposite can also be true: too much of a trace metal can be toxic.

Scientists believe that up to 50% of the trace metals in soils and urban environments may be bound to the surfaces of mineral grains — rendering the trace metals essentially unavailable for consumption or exposure. Researchers at Washington University in St. Louis wondered what holds them in place.

“When minerals bind trace metals, we often assume that they act like a sponge,” said Jeffrey G. Catalano, a professor of earth, environmental and planetary sciences and the director of environmental studies in Arts & Sciences. “But sometimes, they bind trace metals and won’t let them go. That is great when they are contaminants, but bad when they are serving as micronutrients.”

In a study published in the journal Environmental Science & Technology, Catalano and Greg Ledingham, a PhD candidate in his laboratory, discovered that a common mineral called goethite — an iron-rich mineral that is abundant in soils that cover the Earth — tends to incorporate trace metals into its structure over time, binding the metals in such a way that it locks them out of circulation.

SwRI scientists find evidence of geothermal activity within icy dwarf planets

Eris and Makemake
Image Credit: Courtesy of Southwest Research Institute

A team co-led by Southwest Research Institute found evidence for hydrothermal or metamorphic activity within the icy dwarf planets Eris and Makemake, located in the Kuiper Belt. Methane detected on their surfaces has the tell-tale signs of warm or even hot geochemistry in their rocky cores, which is markedly different than the signature of methane from a comet.

“We see some interesting signs of hot times in cool places,” said SwRI’s Dr. Christopher Glein, an expert in planetary geochemistry and lead author of a paper about this discovery. “I came into this project thinking that large Kuiper Belt objects (KBOs) should have ancient surfaces populated by materials inherited from the primordial solar nebula, as their cold surfaces can preserve volatiles like methane. Instead, the James Webb Space Telescope (JWST) gave us a surprise! We found evidence pointing to thermal processes producing methane from within Eris and Makemake.”

The Kuiper Belt is a vast donut-shaped region of icy bodies beyond the orbit of Neptune at the edge of the solar system. Eris and Makemake are comparable in size to Pluto and its moon Charon. These bodies likely formed early in the history of our solar system, about 4.5 billion years ago. Far from the heat of our Sun, KBOs were believed to be cold, dead objects. Newly published work from JWST studies made the first observations of isotopic molecules on the surfaces of Eris and Makemake. These so-called isotopologues are molecules that contain atoms having a different number of neutrons. They provide data that is useful in understanding planetary evolution.

Scientists are unraveling the secrets of red and grey squirrel competition

Image Credit: Gemini Advance AI

In a first of its kind study, researchers have identified significant differences between the diversity of gut bacteria in grey squirrels compared to red squirrels which could hold the key to further understanding the ability of grey squirrels to outcompete red squirrels in the UK. 

New research, published in the Journal of Medical Microbiology, looked to understand more about the mechanisms by which grey squirrels are able to gain an advantage over red squirrels. Chris Nichols, Conservation Evidence Manager at the Woodland Trust, and co-author of the study, said:

“The more we know about grey squirrels, the more equipped we’re going to be in the future to tackle the threats they pose to red squirrels and our native trees, which is one of the biggest problems for forest conservation in the UK.”

Grey squirrels are an invasive, non-native species introduced from North America to sites in Great Britain and Ireland between 1876 to 1929. They out-compete the native red squirrels and multiply thanks to various traits including their ability to access a broader range of food sources including the bark of UK broadleaved trees. This causes significant damage to the trees, and is a behavior that, prior to this research, was not completely understood.