How does radiation travel through dense plasma?

A NASA image of plasma bursting from the sun. Plasma—a hot soup of atoms with free moving electrons and ions—is the most abundant form of matter in the universe, found throughout our solar system in the sun and other planetary bodies. A new study from University of Rochester researchers provides experimental data about how radiation travels through dense plasmas, which will help scientists to better understand planetary science and fusion energy.
Credit: NASA

First-of-its-kind experimental evidence defies conventional theories about how plasmas emit or absorb radiation.

Most people are familiar with solids, liquids, and gases as three states of matter. However, a fourth state of matter, called plasmas, is the most abundant form of matter in the universe, found throughout our solar system in the sun and other planetary bodies. Because dense plasma—a hot soup of atoms with free-moving electrons and ions—typically only forms under extreme pressure and temperatures, scientists are still working to comprehend the fundamentals of this state of matter. Understanding how atoms react under extreme pressure conditions—a field known as high-energy-density physics (HEDP)—gives scientists valuable insights into the fields of planetary science, astrophysics, and fusion energy.

One important question in the field of HEDP is how plasmas emit or absorb radiation. Current models depicting radiation transport in dense plasmas are heavily based on theory rather than experimental evidence.

“This work reveals fundamental steps for rewriting current textbook descriptions of how radiation generation and transport occurs in dense plasmas.”

Tick-borne pathogens increasingly widespread in Central Canada

Image Credit: 13smok

Tick-borne pathogens, known for causing illnesses such as Lyme disease, are on the rise in Central Canada – presenting new risks in areas where they were never previously detected.

The findings from researchers at McGill University and the University of Ottawa demonstrate the need for more comprehensive testing and tracking to detect the spread and potential risk of tick-borne pathogens to human and wildlife populations throughout Canada.

“Most people know that diseases can be transmitted to humans through the bite of infected ticks. Ticks can carry and spread several disease agents, called pathogens, that can make people and animals sick,” explains Kirsten Crandall, a PhD candidate under the joint supervision of McGill University Professor Virginie Millien and University of Ottawa Professor Jeremy Kerr.

“While the bacteria that causes Lyme disease is the most common tick-borne pathogen in Canada, other tick-borne pathogens are moving in,” she adds.

To investigate the presence and prevalence of several emerging tick-borne pathogens, Crandall and her team analyzed small mammals and ticks collected in Ontario and Quebec. The researchers found that five emerging pathogens were present across their study sites in Central Canada, including the pathogens causing Lyme disease and babesiosis, a malaria-like parasitic disease.

‘Lost’ pigeon found after more than a century

Video Credit: Jason Gregg, American Bird Conservancy

A September expedition to Papua New Guinea confirmed via video the existence of the black-naped pheasant pigeon, a critically endangered species that has not been reported for 140 years.

“For much of the trip, it seemed like we had no chance of finding this bird,” said Jordan Boersma, co-leader of the expedition and a postdoctoral researcher at the Cornell Lab of Ornithology. “We were just two days away from the end of our time on Fergusson Island in Papua New Guinea when one of our remote cameras recorded the bird walking around and fanning its tail.”

The group captured the first-ever video and still photos of the bird, a large ground-dwelling species with a rust-colored back, a black head and body, and a bobbing pheasant-like tail. It may only exist far inland on Fergusson Island in hot, extremely rugged geothermal terrain laced with twisty rivers and dense with biting insects and leeches.

“After a month of searching, seeing those first photos of the pheasant pigeon felt like finding a unicorn,” said John C. Mittermeier, director of the Search for Lost Birds project at American Bird Conservancy and a core member of the expedition team. “It’s the kind of moment you dream about your entire life as a conservationist and birdwatcher.”

Scientists closer to solving a superconducting puzzle with applications in medicine, transport and power transmission

Particle accelerator
Source: University of Bristol

Researchers studying the magnetic behavior of a cuprate superconductor may have explained some of the unusual properties of their conduction electrons.

Cuprate superconductors are used in levitating trains, quantum computing and power transmission. They are of a family of materials made of layers of copper oxides alternating with layers of other metal oxides, which act as charge reservoirs.

The largest use of superconductors is currently for manufacturing superconducting magnets used for medical MRI machines and for scientific applications such as particle accelerators.

For the potential applications of superconducting materials to be fully realized, developing superconductors that maintain their properties at higher temperatures is crucial for scientists. The cuprate superconductors currently exhibit relatively high transition point temperatures and therefore give scientists an opportunity to study what makes higher temperature superconductivity possible.

Study yields clues to why Alzheimer’s disease damages certain parts of the brain

Red and orange areas on these heat maps of human brains show where the gene APOE is most active (top two brain images) and where tangles of the protein tau are most concentrated (bottom two brain images). APOE is the biggest genetic risk factor for Alzheimer’s, and tau tangles drive brain damage in the disease. The similarities in the two sets of maps suggested to researchers at Washington University School of Medicine in St. Louis that APOE plays a role in making certain brain areas particularly vulnerable to Alzheimer’s damage.
Image Credit: Diana Hobbs

Memory loss is often the first sign of Alzheimer’s disease, followed by confusion and difficulty thinking. These symptoms reflect the typical pattern of worsening damage to brain tissues. Toxic clusters of proteins first concentrate in the temporal lobes of the brain — the memory area — before spreading to parts of the brain important for thinking and planning.

A study by researchers at Washington University School of Medicine in St. Louis yields clues to why certain parts of the brain are particularly vulnerable to Alzheimer’s damage. It comes down to the gene APOE, the greatest genetic risk factor for Alzheimer’s disease. The parts of the brain where APOE is most active are the areas that sustain the most damage, they found.

The findings, published in Science Translational Medicine, help explain why symptoms of Alzheimer’s disease sometimes vary, and highlights an understudied aspect of Alzheimer’s disease that suggests yet-to-be discovered biological mechanisms may play an important role in the disease.

New nanoscale 3D printing material could offer better structural protection for satellites, drones, and microelectronics

A tiny but strong Stanford logo was made using nanoscale 3D printing.
Image credit: John Kulikowski

Engineers have designed a new material for nanoscale 3D printing that is able to absorb twice as much energy as other similarly dense materials and could be used to create better lightweight protective lattices.

Science fiction envisions rapid 3D printing processes that can quickly create new objects out of any number of materials. But in reality, 3D printing is still limited in the properties and types of materials that are available for use, especially when printing at very small scales.

Researchers at Stanford have developed a new material for printing at the nanoscale – creating structures that are a fraction of the width of a human hair – and used it to print minuscule lattices that are both strong and light. In a paper published in Science, the researchers demonstrated that the new material is able to absorb twice as much energy than other 3D-printed materials of a comparable density. In the future, their invention could be used to create better lightweight protection for fragile pieces of satellites, drones, and microelectronics.

Disease carried by cats, pigs kill 2 spinner dolphins in Hawaiian waters

Photo Credit: Flavio Gasperini

Two spinner dolphins died from toxoplasmosis after becoming infected with the parasite Toxoplasma gondii, according to researchers at the University of Hawaiʻi at Mānoa Health and Stranding Lab. One dolphin was stranded on Hawaiʻi Island in 2015 and the other on Oʻahu in 2019.

Invasive species such as pigs, mongoose, chickens and cats harbor the parasite, but it is unclear which genotypes are most likely to infect wildlife species. The findings were published in Diseases of Aquatic Organisms.

UH researchers screened archived tissues from past dolphin and whale strandings and did not find the parasite in any animals except those that died of it. This demonstrates that if a spinner dolphin has a severe toxoplasmosis infection they will die.

“We suspect that many more spinner dolphins may succumb to toxoplasmosis and die than the animals that are recovered dead and examined for cause of death,” said Kristi West, associate researcher at UH Mānoa’s Hawaiʻi Institute of Marine Biology who directs the UH Health and Stranding Lab. “A better understanding of toxoplasmosis infections and infectious cycles is important to developing effective conservation strategies for protected and endangered Hawaiian wildlife.”

To prevent next pandemic research suggests we need to restore wildlife habit

Researchers found that bats disrupted by a lack of habitat and food move near humans in agricultural and urban areas, where they can spread Hendra virus to horses and then people.
Photo Credit: Vlad Kutepov

Preserving and restoring natural habitats in specific locations could prevent pathogens that originate in wildlife from spilling over into domesticated animals and humans, according to new research led by an international team of researchers, including Penn State.

The research, undertaken in Australia, found that when bats experience a loss of winter habitat and food shortages in their natural settings, their populations splinter and they excrete more virus. Bats disrupted by the lack of food move near humans in agricultural and urban areas. The team studied Hendra virus, a lethal virus that spills over from fruit bats to horses and then infects people.

“One of the biggest challenges we face are threats arising from bat-borne viruses that spillover into humans and have the potential to cause pandemics. Ebola, MERS, SARS, SARS-CoV-2, Nipah and Hendra are all good examples of this,” said Peter Hudson, Willaman Professor of Biology, Penn State. “The response to the pandemic has been to find ways to speed up vaccine development, but since infections invariably spread much faster than vaccine rollout, this reactive response will never stop a pandemic. Instead, the solution lies with preventing viral spillover from bats to humans.”

Neonicotinoid causes ASD-like symptoms in chicks

A simulation of biological motion (left) and leghorn chicks of the same breed as those used in the study (right)
Photo Credit: Toshiya Matsushima

Disturbed transmission via nicotinic acetylcholine receptors in chick fetuses impairs the hatchlings’ preference for animate objects—similar to what is seen in autism spectrum disorder in humans.

Autism spectrum disorder (ASD) refers to a group of disabilities due to atypical brain development. Individuals with ASD have difficulties in social communication and interaction. Diverse causes of ASD are hypothesized, but most of them remain to be understood. A vast research effort has thus been invested to develop appropriate animal models to study the causes.

A team of researchers led by Professor Emeritus Toshiya Matsushima at Hokkaido University found an ASD-like behavioral impairment in chicks, suggesting a molecular pathway of ASD pathogenesis. Their results were published in the online journal Cerebral Cortex Communications.

NIH researchers unlock pattern of gene activity for ADHD

A new study uses postmortem brain tissues to understand genomic differences in individuals with attention deficit hyperactivity disorder.
Image Credit: Gerd Altmann

Researchers at the National Institutes of Health have successfully identified differences in gene activity in the brains of people with attention deficit hyperactivity disorder (ADHD). The study, led by scientists at the National Human Genome Research Institute (NHGRI), part of NIH, found that individuals diagnosed with ADHD had differences in genes that code for known chemicals that brain cells use to communicate. The results of the findings, published in Molecular Psychiatry, show how genomic differences might contribute to symptoms.

To date, this is the first study to use postmortem human brain tissue to investigate ADHD. Other approaches to studying mental health conditions include non-invasively scanning the brain, which allows researchers to examine the structure and activation of brain areas. However, these studies lack information at the level of genes and how they might influence cell function and give rise to symptoms.

The researchers used a genomic technique called RNA sequencing to probe how specific genes are turned on or off, also known as gene expression. They studied two connected brain regions associated with ADHD: the caudate and the frontal cortex. These regions are known to be critical in controlling a person’s attention. Previous research found differences in the structure and activity of these brain regions in individuals with ADHD.