Scorpius images to test nuclear stockpile simulations

Two cathode inductive voltage-adder cells on the electrical test stand are aligned at Sandia National Laboratories. After thousands of tests, each holding 50 kilovolts across the insulating gap, they are ready to be mounted on seven-cell modules.
Photo Credit: Craig Fritz

One thousand feet below the ground, three national defense labs and a remote test site are building Scorpius — a machine as long as a football field — to create images of plutonium as it is compressed with high explosives, creating conditions that exist just prior to a nuclear explosion.

These nanosecond portraits will be compared with visuals of the same events generated by supercomputer codes to check how accurately the computed images replicate the real thing.

“It’s clear we need to know that the stockpile will work if required,” said Jon Custer, Sandia National Laboratories project lead. “Before President Bush’s testing moratorium in 1992, we knew it did since we were physically testing. Now we have computer codes. How well do they predict what really happens? Do we have accurate data we put into the codes? To answer these questions with higher fidelity, we need better experimental tools, and Scorpius is a major new experimental tool.”

The $1.8 billion project, combining the expertise of researchers from Sandia, Los Alamos and Lawrence Livermore national labs with support from the Nevada National Security Site — a test area bigger than the state of Rhode Island — is expected to be up and running by late 2027.

Physicists Find Evidence for Magnetically Bound Excitons

In materials known as antiferromagnetic Mott insulators, electrons (orbs) are organized in a lattice structure of atoms such that their spins point up (blue) or down (pink) in an alternating pattern. This is a stable state in which the energy is minimized. When the material is hit with light, an electron will hop to a neighboring atomic site, leaving a positively charged hole where it once resided (dark orb). If the electron and hole move further apart from each other, the spin arrangement between them becomes disturbed—the spins are no longer pointing in opposite directions to their neighbors as seen in the second panel—and this costs energy. To avoid this energy penalty, the electron and hole prefer to remain close to each other. This is the magnetic binding mechanism underlying the Hubbard exciton.
Illustration Credit: Caltech

In art, the negative space in a painting can be just as important as the painting itself. Something similar is true in insulating materials, where the empty spaces left behind by missing electrons play a crucial role in determining the material's properties. When a negatively charged electron is excited by light, it leaves behind a positive hole. Because the hole and the electron are oppositely charged, they are attracted to each other and form a bond. The resulting pair, which is short lived, is known as an exciton [pronounced exit-tawn].

Excitons are a key part of many technologies, including solar panels, photodetectors and sensors, as well as light-emitting diodes found in televisions and digital display screens. In most cases, the exciton pairs are bound by electrical, or electrostatic, forces, also known as Coulomb interactions. Now, in a new study in Nature Physics, Caltech researchers report detecting excitons that are not bound via Coulomb forces but rather by magnetism. This is the first experiment to detect how these so-called Hubbard excitons, named after the late physicist John Hubbard, form in real-time.

Cellular Atlas of Amygdala Reveals New Treatment Target for Cocaine Addiction

The study was led by co-senior authors Francesca Telese, PhD (left) and Graham McVicker, PhD (right).
Photo credit: UC San Diego Health Sciences

Researchers at University of California San Diego School of Medicine and the Salk Institute for Biological Studies have created a unique, cell-by-cell atlas of the amygdala, a small structure deep within the brain that plays a crucial role in controlling emotional responses to drugs. The findings, published October 5, 2023 in Nature Neuroscience, helped the researchers identify a potential new treatment for cocaine addiction, a disease that is poorly understood at the molecular level and has virtually no approved pharmacological treatments.

“There are some drugs that can help treat other addictions, such as those to opioids or nicotine, but there are currently no safe and effective drugs approved for cocaine addictions,” said co-senior author Francesca Telese, PhD, an associate professor in the Department of Psychiatry at UC San Diego School of Medicine. “These findings help address that problem and could also point to universal molecular mechanisms of addiction that we haven’t understood until now.”

Cocaine is a widely used illicit drug and addiction to cocaine is a major public health concern, associated with a rising number of overdose deaths and a high rate of relapse. Despite the threat cocaine addiction poses, not every person who uses cocaine develops an addiction. According to the National Institute on Drug Abuse, an estimated 4.8 million people used cocaine in 2021, while only 1.4 million people had a cocaine use disorder.

Generating circularly polarized light

Setups for ultrafast laser spectroscopy of novel semiconductors.
Photo Credit: Courtesy of Heidelberg University

A research team under the direction of Prof. Dr Felix Deschler at Heidelberg University’s Institute for Physical Chemistry has developed a semiconductor that efficiently generates light and simultaneously gives that light a certain spin. According to the researchers, the so-called chiral perovskite material has great technological potential that can be used for applications in optoelectronics, telecommunications, and information processing.

Generating bright, circularly polarized light has long been a goal of materials science. It is considered exceedingly difficult to achieve a distinct chirality – which describes the rotation of light in a specific direction – as well as high photoluminescence quantum efficiency (PLQE). The PLQE value expresses the ability of a material to emit light. Inorganic semiconductors are able to emit high brightness but usually exhibit low light polarization. In contrast, organic molecular semiconductors do have high polarization, but their brightness is often limited by losses due to dark conditions. “Until now, a material that truly combines the high luminescence quantum efficiency of inorganic semiconductors and the strong chirality of organic molecular systems has been lacking,” reports Felix Deschler.

Antiviral drugs could preserve capacity to produce insulin in type 1 diabetes patients

People with diabetes type 1 must administer insulin hormone for the rest of their lives.
Photo Credit: PhotoMIX-Company

Antiviral drug treatment could preserve the remaining capacity to release insulin in children recently diagnosed with type 1 diabetes, according to a new study by Scandinavian researchers. Johnny Ludvigsson, senior professor at LiU, was involved in the planning of the study, published in Nature Medicine.

The association between type 1 diabetes and viral infection was evidenced long ago. In their present study, the researchers have given antiviral drugs to children and young people newly diagnosed with type 1 diabetes. According to the study, this treatment partially slowed down the loss of insulin production. This is the first study testing antiviral treatment at the onset of diabetes.

The study was led by Knut Dahl-Jørgensen, senior professor at Oslo University Hospital and the University of Oslo.

“This result is an important step in showing that viruses could trigger diabetes. This means that it may be possible to treat and slow down type 1 diabetes with medication. Maybe eventually it will also prevent the disease,” says Knut Dahl-Jørgensen in a press release.

Psychedelics improve mental health, cognition in special ops veterans

The Colorado River toad (Incilius alvarius), also known as the Sonoran Desert toad, is a toad species found in northwestern Mexico and the southwestern United States. It is well known for its ability to exude toxins from glands within its skin that have psychoactive properties.
Photo Credit: Alan Schmierer
(CC0 1.0 DEED)

One treatment each of two psychedelic drugs lowered depression and anxiety and improved cognitive functioning in a sample of U.S. special operations forces veterans who sought care at a clinic in Mexico, according to a new analysis of the participants’ charts. 

The treatment included a combination of ibogaine hydrochloride, derived from the West African shrub iboga, and 5-MeO-DMT, a psychedelic substance secreted by the Colorado River toad. Both are designated as Schedule I drugs under the U.S. Controlled Substances Act.

In addition to relieving symptoms of post-traumatic stress disorder (PTSD), the combined treatment also alleviated cognitive impairment linked to traumatic brain injury – which stood out to researchers from The Ohio State University who led the chart-review analysis. Many special operations forces veterans seeking treatment for complex psychiatric symptoms do not respond to more traditional therapies. 

“What sets this group apart from some other veterans and civilians is that often, they are exposed to repeated traumatic events as a routine part of their jobs. This build-up of exposure to these difficulties seems to produce a cluster of challenges that include traumatic brain injury, which we know in and of itself predisposes people to mental health problems,” said lead author Alan Davis, associate professor and director of the Center for Psychedelic Drug Research and Education (CPDRE) in Ohio State’s College of Social Work. 

“So, the fact that we saw that there were improvements in cognitive functioning linked to brain injury were probably the most striking results, because that’s something we didn’t predict and it’s very new and novel in terms of how psychedelics might help in so many different domains.” 

New findings pave the way for hearing loss therapies

Fluorescence microscopic image of a murine cochlea: the hair cells are marked in green, the cell skeleton in red and the cell nuclei with genetic material in blue.
Image Credit: Maurizio Cortada, University of Basel, Department of Biomedicine

As we age, many of us will eventually need hearing aids. In some cases, the reason for this may be a signaling pathway that controls auditory sensory cell function and is downregulated with age. Researchers at the University of Basel are uncovering clues.

Hearing loss eventually affects almost everyone: Loud noises or simple aging gradually cause the auditory sensory cells and their synapses in the inner ear to degenerate and die off. The only treatment option is a hearing aid or, in extreme cases, a cochlear implant.

“In order to develop new therapies, we need to better understand what the auditory sensory cells need for proper function,” explains Dr. Maurizio Cortada from the Department of Biomedicine at the University of Basel and University Hospital Basel. In collaboration with Professor Michael N. Hall’s research group at the Biozentrum, Cortada investigated which signaling pathways influence the so-called sensory “hair cells” in the inner ear. In the process, the researchers discovered a central regulator, as they report in the journal iScience.

Bumblebees drop to shake off Asian hornets

Asian hornet
Photo Credit: Public Domain 

Bumblebees have a remarkably successful method for fighting off Asian hornets, new research shows.

When attacked, buff-tailed bumblebees drop to the ground – taking the hornets down with them. This either causes the hornet to lose its grip, or the bee raises its sting and tussles until the hornet gives up.

University of Exeter scientists witnessed over 120 such attacks, and were stunned to find that bumblebees fought off the hornets every time.

Despite this, they found bumblebee colonies had reduced growth rates in areas with high numbers of Asian hornets – suggesting the hornets still had a negative impact, even if their attacks at colony entrances usually failed.

Asian hornets (also known as yellow-legged hornets) have already invaded much of mainland Europe and parts of east Asia, and have recently been reported in the US for the first time.

Sightings in the UK and continental Europe are at record levels this year – raising fears for pollinators and prompting substantial control efforts.

A UCLA-led team may have found the key to stimulating human brown adipose tissue into combating obesity

Photo Credit: Kenny Eliason

A UCLA-led team of researchers has found nerve pathways that supply brown adipose tissue (BAT), a type of tissue that releases chemical energy from fat metabolism as heat – a finding that could pave the way toward using it to treat obesity and related metabolic conditions.

The researchers have for the first time detailed this nerve supply and provided examples of how manipulating it can change BAT activity, marking a first step toward understanding how to use it therapeutically, said senior author Dr. Preethi Srikanthan, professor of medicine in the division of endocrinology, diabetes & metabolism, and the director of the Neural Control of Metabolism Center at the David Geffen School of Medicine at UCLA. The largest deposits of BAT are in the neck.

 “We know from previous literature that the sympathetic nerve system is the main ‘on switch’ for BAT activity,” Srikanthan said. “However, the sympathetic nervous system is also responsible for many other stimulatory effects on organs such as the heart and gut. Finding a way to increase activity of BAT alone has been challenging, so finding out the path these sympathetic nerves take to BAT will allow us to explore ways of using nerves to provide a very specific stimulus to activate BAT.”

New type of tiny wasp comes with mysterious, cloud-like structures at ends of antennae

Fossil researchers have discovered a novel genus and species of tiny wasp with a mysterious, bulbous structure at the end of each antenna.
Photo Credit: George Poinar Jr.

Fossil researchers have discovered a novel genus and species of tiny wasp with a mysterious, bulbous structure at the end of each antenna.

The female micro-wasp was described from 100-million-year-old Burmese amber in a study led by George Poinar Jr., who holds a courtesy appointment in the Oregon State University College of Science.

Poinar and Fernando Vega, an independent researcher based in Silver Spring, Maryland, have some ideas about the “clouds” on the antennae, but they don’t know for sure what they are.

“We could find no fossil or extant insect with such antennal structures,” said Poinar, an international expert in using plant and animal life forms preserved in amber to learn about the biology and ecology of the distant past. “We wondered how it could still fly with that weight.”