. Scientific Frontline

Wednesday, May 17, 2023

New study explains how a common virus can cause multiple sclerosis

Olivia Thomas and Mattias Bronge
Photo Credit: Erik Holmgren

Researchers at Karolinska Institutet have found further evidence for how the Epstein-Barr virus can trigger multiple sclerosis or drive disease progression. A study published in Science Advances shows that some individuals have antibodies against the virus that mistakenly attacks a protein in the brain and spinal cord.

The Epstein-Barr virus (EBV) infects most people early in life and then remains in the body, usually without causing symptoms. The link between EBV and the neurological disease multiple sclerosis (MS) was discovered many years ago and has puzzled researchers ever since. Increasing evidence, including two papers published in Science and Nature last year, suggests that EBV infection precedes MS and that antibodies against the virus may be involved. However, the molecular mechanisms seem to vary between patients and remain largely unknown.

“MS is an incredibly complex disease, but our study provides an important piece in the puzzle and could explain why some people develop the disease,” says Olivia Thomas, postdoctoral researcher at the Department of Clinical Neuroscience, Karolinska Institutet and shared first author of the paper. “We have discovered that certain antibodies against the Epstein-Barr virus, which would normally fight the infection, can mistakenly target the brain and spinal cord and cause damage.”

How Breast Cancer Arises

Breast cancer: polyploid giant cancer cell (PGCC)
Image Credit: National Cancer Institute

In what may turn out to be a long-missing piece in the puzzle of breast cancer, Harvard Medical School researchers have identified the molecular sparkplug that ignites cases of the disease currently unexplained by the classical model of breast-cancer development.

A report on the team’s work is published May 17 in Nature.

“We have identified what we believe is the original molecular trigger that initiates a cascade culminating in breast tumor development in a subset of breast cancers that are driven by estrogen,” said study senior investigator Peter Park, professor of Biomedical Informatics in the Blavatnik Institute at HMS.

The researchers said as many as one-third of breast cancer cases may arise through the newly identified mechanism.

The study also shows that the sex hormone estrogen is the culprit behind this molecular dysfunction because it directly alters a cell’s DNA.

Most, though not all, breast cancers are fueled by hormonal fluctuations. The prevailing view of estrogen’s role in breast cancer is that it acts as a catalyst for cancer growth because it stimulates the division and proliferation of breast tissue, a process that carries the risk for cancer-causing mutations. The new work, however, shows that estrogen causes mischief in a far more direct manner.

Genetic research offers new perspective on the early evolution of animals

Some representatives of comb jellies - (a) Beroe ovata, (b) Euplokamis sp., (c) Nepheloctena sp., (d) Bathocyroe fosteri, (e) Mnemiopsis leidyi, and (f) Ocyropsis sp.
Image Credits: a, b, e, f: Joseph F. Ryan; c: R. Griswold, National Oceanic and Atmospheric Administration; d: Marsh Youngbluth, National Oceanic and Atmospheric Administration.

Mapping gene linkages provides clear-cut evidence for comb jellies as sibling group to all other animals

A study published by University of Vienna and MBARI researchers and their collaborators today in Nature provides new insights into one of the earliest points in animal evolution that happened more than 700 million years ago.

For more than a century, scientists have been working to understand the pivotal moment when an ancient organism gave rise to the diverse array of animals in the world today. As technology and science have advanced, scientists have investigated two alternative hypotheses for which animals—sponges or comb jellies, also known as ctenophores—were most distantly related to all other animals. Identifying this outlier—known as the sibling group—has long eluded scientists.

In the new study, a team of researchers from MBARI, the University of Vienna, the University of California, Berkeley, and the University of California, Santa Cruz, mapped sets of genes that are always found together on a single chromosome, in everything from humans and hamsters to crabs and corals, to provide clear evidence that comb jellies are the sibling group to all other animals. Understanding the relationships among animals will help shape our thinking about how key features of animal anatomy, such as the nervous system or digestive tract, have evolved over time.

Radio signal reveals supernova origin

Artist impression of the double star system with a compact white dwarf star accreting matter from a helium-rich donor companion, surrounded by dense and dusty circumstellar material. It was the interaction of the exploded star and the material left over from this companion that gave rise to the strong radio signal, the conspicuous helium lines in the optical spectra and the infrared emission from SN 2020eyj.
Video Credit: Adam Makarenko/W. M. Keck Observatory

In the latest issue of the journal Nature, an international team including astronomers from University of Turku reveal the origin of a thermonuclear supernova explosion. Strong emission lines of helium and the first detection of such a supernova in radio waves show that the exploding white dwarf star had a helium-rich companion.

Thermonuclear (Type Ia) supernovae are important for astronomers since they are used to measure the expansion of the Universe. However, the origin of these explosions remains an open question. While it is established that the explosion is that of a compact white dwarf star somehow accreting too much matter from a companion star, the exact process and the nature of the progenitor is not known. The new discovery of supernova SN 2020eyj established that the companion star was a so-called helium star that had lost much of its material just prior to the explosion of the white dwarf.

“Once we saw the signatures of strong interaction with the material from the companion, we tried to detect it also in radio emission”, explains Erik Kool, post-doc at the Department of Astronomy at Stockholm University and lead author of the paper. “The detection in radio is actually the first one of a Type Ia supernova – something astronomers have tried to do for decades.”

Scales or feathers? It all comes down to a few genes

From left to right: Rory Cooper, a post-doctoral researcher in Michel Milinkovitch’s laboratory, and Michel Milinkovitch, professor in the Department of Genetics and Evolution at the Faculty of Science of the UNIGE. 
Photo Credit: UNIGE

Scales, spines, feathers and hair are examples of vertebrate skin appendages, which constitute a remarkably diverse group of micro-organs. Despite their natural multitude of forms, these appendages share early developmental processes at the embryonic stage. Two researchers from the University of Geneva (UNIGE) have discovered how to permanently transform the scales that normally cover the feet of chickens into feathers, by specifically modifying the expression of certain genes. These results, published in the journal Science Advances, open new perspectives for studying mechanisms that have enabled radical evolutionary transitions in form among species.

The skin of terrestrial vertebrates is adorned with diverse keratinized appendages, such as hair, feathers, and scales. Despite the diversity of forms within and among species, the embryonic development of skin appendages typically begins in a very similar way. Indeed, all of these structures develop from cells that produce a localized thickening on the skin surface and express particular genes. One of these genes, called Sonic hedgehog (Shh), controls a signaling pathway - a communication system that allows the transmission of messages within and between cells. Shh signaling is involved in the development of diverse structures, including the neural tube, limb buds and skin appendages.

New Model for Human Evolution Suggests Homo Sapiens Arose from Multiple Closely Related Populations

View of the village of Kuboes, on the border of South Africa and Namibia. DNA samples were collected from Nama individuals who have historically lived in the region.
Photo Credit: Brenna Henn/UC Davis

In testing the genetic material of current populations in Africa and comparing against existing fossil evidence of early Homo sapiens populations there, researchers have uncovered a new model of human evolution — overturning previous beliefs that a single African population gave rise to all humans. The new research was published today, May 17, in the journal Nature.

Although it is widely understood that Homo sapiens originated in Africa, uncertainty surrounds how branches of human evolution diverged and how people migrated across the continent, said Brenna Henn, professor of anthropology and the Genome Center at UC Davis, corresponding author of the research.

“This uncertainty is due to limited fossil and ancient genomic data, and to the fact that the fossil record does not always align with expectations from models built using modern DNA,” she said. “This new research changes the origin of species.”

Research co-led by Henn and Simon Gravel of McGill University tested a range of competing models of evolution and migration across Africa proposed in the paleoanthropological and genetics literature, incorporating population genome data from southern, eastern and western Africa.

Are Earth and Venus the only volcanic planets? Not anymore.

LP 791-18 d is an Earth-size world about 90 light-years away. The gravitational tug from a more massive planet in the system, shown as a blue disk in the background, may result in internal heating and volcanic eruptions – as much as Jupiter’s moon Io, the most geologically active body in the solar system.
Illustration Credit: NASA’s Goddard Space Flight Center/Chris Smith/KRBwyle

Scientific Frontline: "At a Glance" Summary

  • Main Discovery: The identification of LP 791-18 d, an Earth-sized exoplanet orbiting a red dwarf star 90 light-years away, which is likely covered in active volcanoes due to intense gravitational heating.
  • Methodology: Researchers utilized photometric data from NASA’s Transiting Exoplanet Survey Satellite (TESS) and the retired Spitzer Space Telescope to detect the planet and analyze its orbit, specifically measuring transit timing variations caused by the gravitational tug of a larger neighboring planet, LP 791-18 c.
  • Key Data: LP 791-18 d has a radius and mass consistent with Earth (approximately 1.03 Earth radii and 0.9 Earth masses) and orbits its host star every 2.8 days; its massive neighbor passes as close as 1.5 million kilometers, generating sufficient tidal friction to fuel volcanic activity comparable to Jupiter’s moon Io.
  • Significance: This finding provides a rare analog for studying the long-term evolution of terrestrial planets and how extensive volcanic outgassing can sustain an atmosphere on tidally locked worlds, potentially allowing water to condense on the planet's dark side.
  • Future Application: The planet serves as a prime target for the James Webb Space Telescope (JWST) to conduct atmospheric spectroscopy, aiming to detect potential biosignatures or volcanic gases like sulfur dioxide.
  • Branch of Science: Exoplanetary Astronomy, Planetary Science.
  • Additional Detail: The planet is tidally locked, meaning one side faces the star permanently, but the suspected global volcanic activity could transport heat and maintain an atmosphere across the night side.

Researchers develop new method to synthesize cannabis plant compound

Photo Credit: Matthew Brodeur

A group of researchers at Leipzig University has developed a new method for synthesizing cis-tetrahydrocannabinol (THC) – a natural substance found in the cannabis plant that produces the characteristic psychoactive effect and has many potential applications, including in the pharmaceutical industry. “Our strategy makes it possible to produce cis-tetrahydrocannabinoids and test them for their biological activity,” explains researcher Caroline Dorsch, who, together with Professor Christoph Schneider from the Institute of Organic Chemistry, has published her findings in the journal Angewandte Chemie.

She points out that until now there has been no way of synthesizing this structural class in a consistent way. With their simple, inexpensive and nature-based synthesis, the Leipzig researchers have for the first time made the substance class of cis-tetrahydrocannabinoids accessible for a broad range of applications. The researcher notes that because previous methods required many steps and large amounts of chemicals and solvents, their approach is clearly superior. The substance can be synthesized with high overall yields and excellent optical purities using the new method.  

Study Finds Carrying Pollen Heats Up Bumble Bees, Raising New Climate Change Questions

Photo Credit: Malia Naumchik.

A new study from North Carolina State University finds carrying pollen is a workout that significantly increases the body temperature of bumble bees. This new understanding of active bumble bee body temperatures raises questions about how these species will be impacted by a warmer world due to climate change.

Spend a bit of time at a nearby flower patch and you will spot a fuzzy bumble bee with yellow bumps on her back legs. These yellow bumps are solid packets of pollen that have been carefully collected during the bees’ foraging trip for transport back to their nests. And while bees may seem to move from flower to flower with ease, these pollen packets can weigh up to a third of their body weight. This new study found that – after accounting for environmental temperature and body size – the body temperature of bumble bees carrying pollen was significantly hotter than the temperature of bees that were empty-legged.

Specifically, the researchers found that bee body temperatures rose 0.07°C for every milligram of pollen that they carried, with fully laden bees being 2°C warmer than unladen bees.

Evidence of ‘pandemic brain’ in college students

“This study provides additional information to understand why students may have been having difficulty coming to class, focusing on class and getting things turned in – because there was this global event affecting every part of their lives,” lead researcher Melissa Buelow says.
Photo Credit: RF._.studio

Decision-making capabilities of college students – including some graduating this spring – were likely negatively affected by the COVID-19 pandemic, new research suggests.

Students in the small study conducted by researchers at The Ohio State University were less consistent in their decision making during the 2020 fall semester compared to students who had participated in similar research over several previous years.

The researchers compared responses to a hypothetical situation made by students during the pandemic to responses made by students in earlier studies. They found evidence that students in 2020 were more likely to cycle between going with their gut and more thoroughly mulling over their answers depending on how the scenario was described.

“Our theory is that feeling stressed by everything going on was limiting students’ resources to really evaluate the information that was presented to them,” said lead author Melissa Buelow, professor of psychology at Ohio State’s Newark campus. 

A better way to study ocean currents

Computer scientists at MIT joined forces with oceanographers to develop a machine-learning model that incorporates knowledge from fluid dynamics to generate more accurate predictions about the velocities of ocean currents. This figure shows drifting buoy trajectories in the Gulf of Mexico superimposed on surface currents. The red dots mark the buoys’ positions on March 9, 2016, and the tails are 14 days long.
Image Credits: Edward Ryan and Tamay Özgökmen from the University of Miami.

A new machine-learning model makes more accurate predictions about ocean currents, which could help with tracking plastic pollution and oil spills, and aid in search and rescue.

To study ocean currents, scientists release GPS-tagged buoys in the ocean and record their velocities to reconstruct the currents that transport them. These buoy data are also used to identify “divergences,” which are areas where water rises up from below the surface or sinks beneath it.

By accurately predicting currents and pinpointing divergences, scientists can more precisely forecast the weather, approximate how oil will spread after a spill, or measure energy transfer in the ocean. A new model that incorporates machine learning makes more accurate predictions than conventional models do, a new study reports.

A multidisciplinary research team including computer scientists at MIT and oceanographers has found that a standard statistical model typically used on buoy data can struggle to accurately reconstruct currents or identify divergences because it makes unrealistic assumptions about the behavior of water.

The researchers developed a new model that incorporates knowledge from fluid dynamics to better reflect the physics at work in ocean currents. They show that their method, which only requires a small amount of additional computational expense, is more accurate at predicting currents and identifying divergences than the traditional model.

Mystery of important blood pressure drugs solved

Prof. Daniel Fuster, M.D. Department for BioMedical Research (DBMR) of the University of Bern and Department of Nephrology and Hypertension, Inselspital, Bern University Hospital.
Photo Credit: Courtesy of Daniel Fuster

Diuretic drugs from the thiazide group have been used for 60 years to treat high blood pressure. But they also increase the risk of developing diabetes. Researchers at the University of Bern and Inselspital have now pinpointed the cause of this side effect and in the process also gained new insights into the development of diabetes.

High blood pressure is a global health problem. In Switzerland, one in two people over the age of 65 has high blood pressure. This has been shown to increase the risk of serious secondary diseases such as dementia, stroke, cerebral hemorrhage, heart attack, and kidney failure. According to estimates by the World Health Organization, for example, around 54 percent of strokes are a direct result of high blood pressure. "Accordingly, there is a great need for effective, and also inexpensive and widely available antihypertensive drugs - particularly in light of our aging society," explains Prof. Daniel Fuster, M.D., from the Department for BioMedical Research at the University of Bern (DBMR) and Head Physician at the Department of Nephrology and Hypertension at Inselspital, Bern University Hospital.

Curved spacetime in a quantum simulator

   In the background: the gravitational lens effect, an example of an effect explained by relativity. With quantum particles, analogous effects can be studied.
Image Credit: NASA / TU Wien

New techniques can answer questions that were previously inaccessible experimentally - including questions about the relationship between quantum mechanics and relativity.

The theory of relativity works well when you want to explain cosmic-scale phenomena - such as the gravitational waves created when black holes collide. Quantum theory works well when describing particle-scale phenomena - such as the behavior of individual electrons in an atom. But combining the two in a completely satisfactory way has yet to be achieved. The search for a "quantum theory of gravity" is considered one of the significant unsolved tasks of science.

This is partly because the mathematics in this field is highly complicated. At the same time, it is tough to perform suitable experiments:  One would have to create situations in which phenomena of both the relativity theory play an important role, for example, a spacetime curved by heavy masses, and at the same time, quantum effects become visible, for example the dual particle and wave nature of light.

Fauna return rapidly in planted eelgrass meadows

Comparison between newly planted eelgrass, to the left and eelgrass that is 15 months old, right.
Photo Credit: Eduardo Infantes

A study of eelgrass meadows planted by researchers from the University of Gothenburg shows that fauna return rapidly once the eelgrass has started to grow. Already after the second summer, the biodiversity in the planted meadow was almost the same as in old established eelgrass meadows.

Eelgrass meadows have declined heavily in southern Bohus county in recent decades and in many places have disappeared altogether. Researchers at the University of Gothenburg have been working on the restoration of eelgrass meadows for twelve years. These meadows are important for biodiversity, as the eelgrass serves as habitat or nursery for young cod, crabs and shrimps for example.  

In a new study, the researchers have evaluated how rapidly replanted eelgrass gets populated by various invertebrates. The study has been going on for over two years in a bay near Gåsö island just west of Skaftö in Bohus county, and the findings are very positive. The researchers counted the abundance of invertebrates that live or burrow in bottom sediments or on the surface of bottom sediments.

Tuesday, May 16, 2023

New transparent augmented reality display opens possibilities to see digital content in real-time

The flexible, transparent polymer-based material will advance how AR is used across a range of industries.
Photo Credit: Cesar Nicolas

The world's first flexible, transparent augmented reality (AR) display screen using 3D printing and low-cost materials has been created by researchers at the University of Melbourne, KDH Design Corporation and the Melbourne Centre for Nanofabrication (MCN). The development of the new display screen is set to advance how AR is used across a wide range of industries and applications.

AR technology overlays digital content onto the real world, enhancing the user's real-time perception and interaction with their environment. Until now, creating flexible AR technology that can adjust to different angles of light sources has been a challenge, as current mainstream AR manufacturing uses glass substrates, which must undergo photomasking, lamination, cutting, or etching microstructure patterns. These time-consuming processes are expensive, have a poor yield rate and are difficult to seamlessly integrate with product appearance designs.

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