Genetic study: Unexpectedly high variation in T-cell receptor genes between persons

Using blood samples, the researchers examined TCR genes in 45 people from different parts of the world.
Photo Credit: Ahmad Ardity

Researchers from Karolinska Institutet have discovered that the genes encoding our T cell receptors vary greatly between persons and populations, which may explain why we respond differently to for example infections. The findings, presented in the journal Immunity, also demonstrate that some gene variants are inherited from Neanderthals.

T-cells that are part of our immune system are central in the protection against infections and cancer. With the help of TCRs, the cells recognize foreign invaders and tumor cells.

“It was previously unknown how variable human TCR genes are”, says Gunilla Karlsson Hedestam, professor at the department of microbiology, tumor and cell biology at Karolinska Institutet and the study's lead author.

Persons from different parts of the world were included

Using deep sequencing of blood samples, the researchers examined TCR genes in 45 people originating from sub-Saharan Africa, East Asia, South Asia and Europe. The researchers showed that these genes vary greatly between different persons and population groups. The results were confirmed by analyses of several thousand additional cases from the 1000 Genomes project.

Discovering the magic in superconductivity’s ‘magic angle’

Left: Marc Bockrath, professor of physics. Center: Jeanie Lau, professor of physics. Right: Mohit Randeria, professor of physics.
Photo Credit: Photos courtesy of Ohio State University

Researchers have produced new evidence of how graphene, when twisted to a precise angle, can become a superconductor, moving electricity with no loss of energy.

In a study published today (Feb. 15, 2023) in the journal Nature, the team led by physicists at The Ohio State University reported on the key role that quantum geometry plays in allowing this twisted graphene to become a superconductor.

Graphene is a single layer of carbon atoms, the lead that is found in a pencil.

In 2018, scientists at the Massachusetts Institute of Technology discovered that, under the right conditions, graphene could become a superconductor if one piece of graphene were laid on top of another piece and the layers were twisted to a specific angle – 1.08 degrees – creating twisted bilayer graphene.

Ever since, scientists have been studying this twisted bilayer graphene and trying to figure out how this “magic angle” works, said Marc Bockrath, professor of physics at Ohio State and co-author of the Nature paper.

Novel Optical and fMRI Platform Identifies Brain Regions that Control Large-scale Brain Network

Default mode network examined by fMRI and optical fiber photometry.
Illustration Credit: Shih Lab

Researchers from the UNC School of Medicine, led by Ian Shih, PhD, Professor and Vice Chair of Neurology and Associate Director of the Biomedical Research Imaging Center, revealed the role of the insular cortex in controlling the Default Mode Brain Network.

When we daydream or revisit memories, a large group of regions within our brain “lights up,” or becomes more active. It’s referred to as the Default Mode Network (DMN) because it is more active when the brain is not focused on the outside world.

Numerous brain disorders, including Alzheimer’s, attention-deficit/hyperactivity disorder, and mood disorders, have been linked to issues with the DMN. However, the neurophysiological basis of the DMN is not well understood.

Neuroimaging techniques, like functional magnetic resonance imaging (fMRI), are not able to directly measure neuronal activity. To address this knowledge gap, a research team led by Ian Shih, PhD, professor and vice chair of the Department of Neurology and associate director of the Biomedical Research Imaging Center, has created a novel experimental platform that is able to optically record local neuronal activity during brain-wide fMRI in rodents.

Scientists find first observational evidence linking black holes to dark energy

Artist’s impression of a supermassive black hole. Cosmological coupling allows black holes to grow in mass without consuming gas or stars.
Image Credit: UH Manoa

Searching through existing data spanning 9 billion years, a University of Michigan physicist and colleagues have uncovered the first evidence of “cosmological coupling”—a newly predicted phenomenon in Einstein’s theory of gravity, possible only when black holes are placed inside an evolving universe.

Gregory Tarlé, U-M professor of physics, and researchers from the University of Hawaii and other institutions across nine countries studied supermassive black holes at the heart of ancient and dormant galaxies to develop a description of them that agrees with observations from the past decade. Their findings are published in two journal articles, one in The Astrophysical Journal and the other in The Astrophysical Journal Letters.

The first study found that these black holes gain mass over billions of years in a way that can’t easily be explained by standard galaxy and black hole processes, such as mergers or accretion of gas. According to the second paper, the growth in mass of these black holes matches predictions for black holes that not only cosmologically couple, but also enclose vacuum energy—material that results from squeezing matter as much as possible without breaking Einstein’s equations, thus avoiding a singularity.

New compound that withstands extreme heat and electricity could lead to next-generation energy storage devices

A new type of polysulfate compound can be used to make polymer film capacitors that store and discharge high density of electrical energy while tolerating heat and electric fields beyond the limits of existing polymer film capacitors.
Illustration Credit: Yi Liu and He (Henry) Li/Berkeley Lab

Society’s growing demand for high-voltage electrical technologies – including pulsed power systems, cars and electrified aircraft, and renewable energy applications – requires a new generation of capacitors that store and deliver large amounts of energy under intense thermal and electrical conditions. Researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Scripps Research have now developed a new polymer-based device that efficiently handles record amounts of energy while withstanding extreme temperatures and electric fields. The device is composed of materials synthesized via a next-generation version of the chemical reaction for which three scientists won the 2022 Nobel Prize in Chemistry.

Polymer film capacitors are electrical components that store and release energy within an electric field using a thin plastic layer as the insulating layer. They make up 50% of the global high voltage capacitor market and offer advantages including light weight, low cost, mechanical flexibility, and robust cyclability. But state-of-the-art polymer film capacitors decrease dramatically in performance with increasing temperature and voltages. Developing new materials with improved tolerance for heat and electric fields is paramount; and creating polymers with near-perfect chemistry offers a way to do so.

Climate Change Could Cause Mass Exodus of Tropical Plankton

Plankton under a microscope. Researchers at UT Austin say that tropical plankton like this may vanish as the climate warms.
Photo Credit: Tracy Aze.

The tropical oceans are home to the most diverse plankton populations on Earth, where they form the base of marine food chains. Modern plankton biodiversity in the tropics is a surprisingly recent development and the result of 8 million years of global cooling, according to a study led by researchers at The University of Texas at Austin.

The finding raises concerns that rapid ocean warming could force the plankton to move away from the tropics, which would negatively affect ocean ecosystems, including those of important fish such as tuna and billfish, and coastal communities that depend on them. The research was published in the journal Nature.

Using microfossils to track the history of a group of zooplankton called Foraminifera, the researchers found that the last time Earth was this warm – just before global cooling began 8 million years ago – tropical plankton populations lived in waters more than 2,000 miles from where they are today. The natural cooling of the past 8 million years that allowed the plankton to flourish in the tropics has been reversed by climate change during the past century.

Genetic test can detect deadly bleeding disorder in dogs

Jenna, a Scottish deerhound owned by Laura Studer, has a DNA sample taken from her in Gig Harbor.
 Photos Credit: WSU College of Veterinary Medicine/Ted S. Warren.

A new genetic test can identify dogs at risk of a potentially deadly disorder resulting in excessive bleeding and bruising in the hours and days following surgical procedures.

A team led by Washington State University researchers developed the DEPOHGEN (TM) test following a study in which they examined Scottish deerhounds and identified a gene associated with the condition known as delayed postoperative hemorrhage or DEPOH. Animals with a mutation in the DEPOH gene are significantly more likely to experience the condition. The study was published in the Journal of Veterinary Internal Medicine.

“Dogs with the DEPOH mutation have a much higher risk than other dogs of developing this after undergoing surgery,” said Dr. Michael Court, the study’s corresponding author. “The DEPOHGEN test will allow us to prevent delayed postoperative hemorrhage by administering antifibrinolytic drugs to dogs that test positive for the gene before any surgery.”

Delayed postoperative hemorrhage was first recorded in greyhounds, but it has also been noted in other sighthound breeds, like Scottish deerhounds and Irish wolfhounds. Following the identification of the DEPOH gene, the team examined samples from WSU’s pet DNA bank and discovered the mutation in additional sighthounds, like Italian greyhounds and salukis, as well as in some other popular breeds, such as golden retrievers and border collies.

Engineers discover a new way to control atomic nuclei as “qubits”

Diagram illustrates the way two laser beams of slightly different wavelengths can affect the electric fields surrounding an atomic nucleus, pushing against this field in a way that nudges the spin of the nucleus in a particular direction, as indicated by the arrow.
Illustration Credit: Courtesy of the researchers | MIT
Creative Commons

In principle, quantum-based devices such as computers and sensors could vastly outperform conventional digital technologies for carrying out many complex tasks. But developing such devices in practice has been a challenging problem despite great investments by tech companies as well as academic and government labs.

Today’s biggest quantum computers still only have a few hundred “qubits,” the quantum equivalents of digital bits.

Now, researchers at MIT have proposed a new approach to making qubits and controlling them to read and write data. The method, which is theoretical at this stage, is based on measuring and controlling the spins of atomic nuclei, using beams of light from two lasers of slightly different colors. The findings are described in a paper published Tuesday in the journal Physical Review X, written by MIT doctoral student Haowei Xu, professors Ju Li and Paola Cappellaro, and four others.

Nuclear spins have long been recognized as potential building blocks for quantum-based information processing and communications systems, and so have photons, the elementary particles that are discreet packets, or “quanta,” of electromagnetic radiation. But coaxing these two quantum objects to work together was difficult because atomic nuclei and photons barely interact, and their natural frequencies differ by six to nine orders of magnitude.

Two-dimensional oxides open door for high-speed electronics

Furkan Turker, graduate student in the Department of Materials Sciences, works on a silicon carbide chip in the laboratory 
Photo Credit: Pennsylvania State University
 Creative Commons

Advances in computing power over the decades have come thanks in part to our ability to make smaller and smaller transistors, a building block of electronic devices, but we are nearing the limit of the silicon materials typically used. A new technique for creating 2D oxide materials may pave the way for future high-speed electronics, according to an international team of scientists.

“One way we can make our transistors, our electronic devices, work faster is to shrink the distance electrons have to travel between point A and B,” said Joshua Robinson, professor of materials science and engineering at Penn State. “You can only go so far with 3D materials like silicon — once you shrink it down to a nanometer, its properties change. So, there’s been a massive push looking at new materials, one of which are 2D materials.”

The team, led by Furkan Turker, graduate student in the Department of Materials Sciences, used a technique called confinement hetroepitaxy, or CHet, to create 2D oxides, materials with special properties that can serve as an atomically thin insulating layer between layers of electrically conducting materials.

“Now we can create essentially the world’s thinnest oxides — just a few atoms thick,” Turker said. “That allows you to bring conducting layers closer together than ever without letting them touch. This enables the formation of an ultrathin barrier between conducting layers, which is essential for the fabrication of next-generation electronic devices, such as diodes or transistors.”

World’s oldest European hedgehog

European hedgehog
Photo Credit: Monicore

The world’s oldest scientifically-confirmed European hedgehog has been found in Denmark by a citizen science project involving hundreds of volunteers. The male hedgehog, called Thorvald, lived for 16 years, 7 years longer than the previous record holder.

"I vividly remember the day when I counted 16 growth rings in the microscope. I was completely overwhelmed and even shed a tear of joy! Because if a hedgehog can reach an age of 16 years, there is still hope for the population."

Dr Sophie Lund Rasmussen, Wildlife Conservation Research Unit (WildCRU), Department of Biology, University of Oxford.

The European hedgehog is one of our most beloved mammals but populations have declined dramatically in recent years. In the UK, studies indicate that urban populations have fallen by up to 30% and rural populations by at least 50% since the turn of the century. To combat this, researchers and conservationists have launched various projects to monitor hedgehog populations, to inform initiatives to protect hedgehogs in the wild. These include “The Danish Hedgehog Project”, a citizen science project led by Dr Sophie Lund Rasmussen (aka ‘Dr Hedgehog’) of Oxford University’s Wildlife Conservation Research Unit, WildCRU, part of the Department of Biology.

During 2016, The Danish Hedgehog Project asked Danish citizens to collect any dead hedgehogs they found to better understand how long individual Danish hedgehogs typically live for. Over 400 volunteers collected an astonishing 697 dead hedgehogs originating from all over Denmark, with a roughly 50/50 split from urban and rural areas.