Galactic explosion offers astrophysicists new insight into the cosmos

Study reveals new details about the universe’s chemical formation

Peer-Reviewed Publication

OHIO STATE UNIVERSITY

COLUMBUS, Ohio – Using data from the James Webb Space Telescope’s first year of interstellar observation, an international team of researchers was able to serendipitously view an exploding supernova in a faraway spiral galaxy. 

The study, published recently in The Astrophysical Journal Letters, provides new infrared measurements of one of the brightest galaxies in our cosmic neighborhood, NGC 1566, also known as the Spanish Dancer. Located about 40 million miles away from Earth, the galaxy’s extremely active center has led it to become especially popular with scientists aiming to learn more about how star-forming nebulae form and evolve. 

In this case, scientists were able to survey a Type 1a supernova – the explosion of a carbon-oxygen white dwarf star, which Michael Tucker, a fellow at the Center for Cosmology and AstroParticle Physics at The Ohio State University and a co-author of the study, said researchers caught by mere chance while studying NGC 1566.

“White dwarf explosions are important to the field of cosmology, as astronomers often use them as indicators of distance,” said Tucker. “They also produce a huge chunk of the iron group elements in the universe, such as iron, cobalt and nickel.”

The research was made possible thanks to the PHANGS-JWST Survey, which, due to its vast inventory of star cluster measurements, was used to create a reference dataset to study in nearby galaxies. By analyzing images taken of the supernova’s core, Tucker and co-author Ness Mayker Chen, a graduate student in astronomy at Ohio State who led the study, aimed to investigate how certain chemical elements are emitted into the surrounding cosmos after an explosion.

For instance, light elements like hydrogen and helium were formed during the big bang, but heavier elements can be created only through the thermonuclear reactions that happen inside supernovas. Understanding how these stellar reactions affect the distribution of iron elements around the cosmos could give researchers deeper insight into the chemical formation of the universe, said Tucker. 

“As a supernova explodes, it expands, and as it does so, we can essentially see different layers of the ejecta, which allows us to probe the nebula’s core,” he said. Powered by a process called radioactive decay – wherein an unstable atom releases energy to become more stable – supernovas emit radioactive high-energy photons like uranium-238. In this instance, the study specifically focused on how the isotope cobalt-56 decays into iron-56. 

Using data from JWST’s near-infrared and mid-infrared camera instruments to investigate the evolution of these emissions, researchers found that more than 200 days after the initial event, supernova ejecta was still visible at infrared wavelengths that would have been impossible to image from the ground. 

“This is one of those studies where if our results weren’t what we expected, it would have been really concerning,” he said. “We’ve always made the assumption that energy doesn’t escape the ejecta, but until JWST, it was only a theory.”

For many years, it was unclear whether fast-moving particles produced when cobalt-56 decays into iron-56 seeped into the surrounding environment, or were held back by the magnetic fields supernovas create. 

Yet by providing new insight into the cooling properties of supernova ejecta, the study confirms that in most circumstances, ejecta doesn’t escape the confines of the explosion. This reaffirms many of the assumptions scientists have made in the past about how these complex entities work, Tucker said. 

“This study validates almost 20 years’ worth of science,” he said. “It doesn’t answer every question, but it does a good job of at least showing that our assumptions haven’t been catastrophically wrong.”

Future JWST observations will continue to help scientists develop their theories about star formation and evolution, but Tucker said that further access to other types of imaging filters could help test them as well, creating more opportunities to understand wonders far beyond the edges of our own galaxy. 

“The power of JWST is really unparalleled,” said Tucker. “It’s really promising that we’re accomplishing this kind of science and with JWST, there’s a good chance we’ll not only be able to do the same for different kinds of supernovas, but do it even better.”

This work was supported by the National Science Foundation, the Natural Sciences and Engineering Research Council of Canada, and others. 

Written by: Tatyana Woodall, Woodall.52@osu.ed

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JOURNAL

The Astrophysical Journal Letters

DOI

10.3847/2041-8213/acb6d8 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Serendipitous Nebular-phase JWST Imaging of SN Ia SN 2021aefx: Testing the Confinement of 56Co Decay Energy

Baby star near the black hole in the middle of our Milky Way: It exists after all

Peer-Reviewed Publication

UNIVERSITY OF COLOGNE

 

IMAGE: THE GALACTIC CENTRE AT A DISTANCE OF ABOUT 30000 LIGHT YEARS. IN THE CENTRE OF THE IMAGE IS THE SUPERMASSIVE BLACK HOLE SGR A* (NOT VISIBLE). THE POSITION OF SGR A* CAN BE INFERRED FROM THE MOTION OF THE STARS. BECAUSE OF THE DUST CLOUD AND ITS DIMENSIONS AROUND X3A THE BABY STAR IS ALSO NOT VISIBLE IN THIS IMAGE. view more 

CREDIT: FLORIAN PEISSKE

An international team of researchers under the leadership of Dr Florian Peißker at the University of Cologne’s Institute of Astrophysics has discovered a very young star in its formation phase near the supermassive black hole Sagittarius A* (Sgr A*) at the centre of our Milky Way. The star is only several tens of thousands of years old, making it younger than humanity. The special thing about baby star X3a is that theoretically it should not be able to exist so close to the supermassive black hole in the first place. However, the team believes that it formed in a dust cloud orbiting the giant black hole and sank to its current orbit only after it had formed. The study “X3: a high-mass Young Stellar Object close to the supermassive black hole Sgr A*” has been published in The Astrophysical Journal.

The vicinity of the black hole at the centre of our Galaxy is generally considered to be a region characterized by highly dynamic processes and hard X-ray and UV radiation. Precisely these conditions act against the formation of stars like our Sun. Therefore, for a long time scientists had assumed that over periods of billions of years, only old, evolved stars can settle by dynamical friction in the vicinity of the supermassive black hole. However, quite surprisingly, already twenty years ago very young stars were found in the immediate vicinity of Sgr A*. It is still not clear how these stars got there or where they formed. The occurrence of very young stars very close to the supermassive black hole has been referred to as “the paradox of youth”.

The baby star X3a – which is ten times as big and fifteen times as heavy as our Sun – could now close the gap between star formation and the young stars in the immediate vicinity of Sgr A*. X3a needs special conditions to form in the immediate vicinity of the black hole. First author Dr Florian Peißker explained: “It turns out that there is a region at a distance of a few light years from the black hole which fulfils the conditions for star formation. This region, a ring of gas and dust, is sufficiently cold and shielded against destructive radiation.” Low temperatures and high densities create an environment in which clouds of hundreds of solar masses can form. These clouds can in principle move very fast towards the direction of the black hole due to cloud–cloud collisions and scattering that remove the angular momentum.

In addition, very hot clumps formed in close proximity to the baby star which could then be accreted by X3a. These clumps could thus also contribute to X3a reaching such a high mass in the first place. However, these clumps are only a part of the formation history of X3a. They still do not explain its “birth”.

The scientists assume the following scenario to be possible: shielded from the gravitational influence of Sgr A* and intense radiation, a dense enough cloud could have formed in the outer gas and dust ring around the centre of the Galaxy. This cloud had a mass of about one hundred suns and collapsed under its own gravity to one or more protostars. “This so-called fall time approximately corresponds to the age of X3a,” Peißker added. Observations have shown that there are many of these clouds that can interact with each other. It is therefore likely that a cloud falls towards the black hole from time to time.

This scenario would also fit X3a’s stellar development phase, which is currently evolving into a mature star. It is therefore quite plausible that the gas and dust ring acts as the birthplace of the young stars in the centre of our Galaxy. Dr Michal Zajaček at Masaryk University in Brno (Czech Republic), a co-author of the study, clarified: “With its high mass of about ten times the Solar mass, X3a is a giant among stars, and these giants evolve very quickly towards maturity. We have been lucky to spot the massive star in the midst of the comet-shaped circumstellar envelope. Subsequently, we identified key features associated with a young age, such as the compact circumstellar envelope rotating around it.”

Since similar dust and gas rings can be found in other galaxies, the described mechanism could apply there as well. Many galaxies can therefore host very young stars in their very centres. Planned observations with NASA’s James Webb Space Telescope or the European Southern Observatory’s Extremely Large Telescope in Chile will test this star formation model for our Galaxy as well as others.

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DOI

10.3847/1538-4357/aca977 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

X3: a high-mass Young Stellar Object close to the supermassive black hole Sgr A*

ARTICLE PUBLICATION DATE

28-Feb-2023

The highlight advances in planetary science over the past 20 years

Peer-Reviewed Publication

BEIJING INSTITUTE OF TECHNOLOGY PRESS CO., LTD

With the development of human space technology, planetary exploration has become one of the most important space exploration activities of mankind. As of December 2021, a total of 252 planetary probes have been launched around the world. The missions reveal the deep space to humankind. In the new paper published in the journal Space: Science & Technology, Yixin Sun et al review some advances in planetary science made by these missions in the past years.

1.Research Advances in Terrestrial Planets

    1. Mercury

Mercury is the closest planet to the Sun and the smallest planet in our solar system in terms of volume and mass. It has a similar internal structure to Earth, with a crust, mantle, and core. The density of Mercury is deduced to be about 5.4 g/cm3. The high density suggests that Mercury consists of a large fraction of metallic elements, such as iron and aluminum. Many ridges and scraps on Mercury indicate that there may have been global contractions in the interior of Mercury. One of the most well-known scraps is Carnegie Rupes.

Above its surface, Mercury holds an extremely thin atmosphere due to its weak gravity and high temperature. Ground-based optical measurements reveal that this atmosphere is composed of sodium (Na), magnesium (Mg), oxygen (O), and other elements. Some of these elements show a comet-like spatial distribution. The exosphere contains not only neutral atoms but also many heavy ions, including sodium, oxygen, and magnesium ions.

The Mariner 10 flyby observations in the 1970s indicate that Mercury may have a global intrinsic magnetic field at its surface, which is about 1% of that at Earth's surface. The magnetic field forms a magnetosphere in the interaction with the solar wind.

The most recent Mercury future exploration program is the BepiColombo mission, which was jointly developed by the Japan Aerospace Exploration Agency (JAXA) and the European Space Agency (ESA). It was launched on 2018 October 20 and is scheduled to start orbiting Mercury on 2025 November 5. This mission will investigate Mercury's formation, evolution, geological history, exosphere, and magnetosphere, and verify Einstein's theory of general relativity.

    2. Venus

    The internal structure of Venus remains unknown due to the lack of seismological and inertial measurements. Considering its similarity to Earth in density and radius, it is presumed to have an internal structure similar to that of Earth. Plenty of volcanoes are present on the surface of Venus, which may be the main pathway for Venus to release internal heat. several hotspots probably covered by magma not cooling down completely were discovered by the infrared observations with Venus Express, indicating recent volcanism.

Venus has the densest atmosphere among the 4 terrestrial planets in the solar system, and its atmospheric pressure is up to 92 bar. The major components of the atmosphere are carbon dioxide (about 96.5%) and molecular nitrogen (about 3.5%). Venus's dense atmosphere circulates at a speed that is even faster than its rotation speed. Horinouchi et al. compared the contributions of thermal tides, Rossby waves, etc. to the maintenance of the super-rotation, considering thermal tides are the predominant contributor of the atmospheric angular momentum. During the first flyby of Venus Express, a double-eye atmospheric vortex is observed in the polar region of Venus, having clear temporal evolution and complex morphology.

Although Venus does not have an intrinsic dipole magnetic field, the dense atmosphere can also prevent the solar wind from eroding its surface. The photoionized components of the atmosphere form an ionosphere, and its interaction with solar wind produces ionospheric electric currents that induce a sufficient magnetic field.

Future missions to Venus mainly include FLAGSHIP 2020, DAVINCI, and VERITAS 2030 of the US National Aeronautics and Space Administration (NASA); Shukrayaan-1 2024 of the Indian Space Research Organisation; Russian Venera-D 2029; and ESA's Envision.

    3. Mars

InSight has detected over 700 marsquakes on Mars. A seismological analysis suggests that Mars has an internal structure similar to that of Earth.

Mars has an atmosphere that is much thinner than those of Earth and Venus, and its average atmospheric pressure is only less than 1% of that of Earth. The main components of the atmosphere are carbon dioxide (95.3%), nitrogen (2.7%), and argon (1.6%), plus methane and water. Geological evidence suggests that Mars may have had a dense atmosphere and surface water in the past, and is the most potentially habitable planet except for Earth.

Global, intense, and long-lasting dust storm activities are one of the key characteristics of the Martian atmosphere, which also affect the atmospheric loss. A recent global dust storm in 2018 was clearly captured by the camera onboard Mars Reconnaissance Orbiter.

Like Venus, Mars does not have an intrinsic magnetic field. The magnetic field at Mars is contributed by rock remanence mainly and also by the ionospheric electric current system.

Tianwen-1, China's first mission to Mars. It mainly aims at investigating the Martian atmosphere, ionosphere, magnetosphere, and their dynamic processes with a complete set of scientific payloads. There are several other Mars exploration missions in the next decade, including the ExoMars (2022) mission by ESA and the Russian Federal Space Agency (Roscosmos) and the Martian Moons eXploration (MMX) program by the JAXA.

2.Research Advances in Jovian Planets

1. Jupiter

Jupiter is a gas giant planet with the fifth largest distance (from near to far) from the Sun and also the largest planet in the solar system. The main components of Jupiter are hydrogen and helium, and its internal structure is still inconclusive. Because of its rapid rotation (rotation period of about 9.9 h), Jupiter is ellipse-shaped with an elongated equator. It has extremely rich atmospheric activities and an extremely strong intrinsic magnetic field.

By the measurements of the Doppler effect on radio broadcasts, Juno's measurements can determine the gravity field precisely. The results reveal that Jupiter has a north–south asymmetric gravity field, which is ascribed to atmospheric and internal flow. The atmospheric zonal wind could be as deep as 3,000 km.

With the measurements of Juno, a new spherical harmonic model (JRM09) of the magnetic field of Jupiter is obtained from vector magnetic field observations. The model describes the planet's intrinsic magnetic field much better than before, clearly showing the north–south asymmetry, especially the anomaly at the north pole.

Water on Jupiter is mainly in the form of clouds under the clouds of ammonia (NH3) and ammonium hydrosulfide (NH4SH).

Juno's measurements indicate that the atmosphere is very complex. At low latitudes, it is mainly an axisymmetric zonal cloud belt, while at high latitudes, it transforms into cyclones. In the northern hemisphere, a polar cyclone is surrounded by 8 small cyclones, while in the southern hemisphere, there are 5 small cyclones. The Great Red Spot is a hallmark of Jupiter and was discovered hundreds of years ago. It does not have a static shape and has shrunk significantly since 1879. During the observation of Juno, the Great Red Spot was also eroded by several anticyclones, which decreased its area and increased its internal rotation speed.

Up to now, the missions that are determined to explore the Jovian system mainly aim at Jupiter moons. Jupiter Icy Moons Explorer (JUICE) will detect 3 icy Galilean moons: Ganymede, Callisto, and Europa. NASA also has its exploration mission, Europa Clipper, which will study Europa's habitability and select a location for a possible landing mission.

    2. Saturn

Saturn is the sixth planet in terms of the distance to the Sun, and its volume is second only to that of Jupiter. It is mainly composed of hydrogen with a small amount of helium and other elements. The strength of Saturn's planetary magnetic field is between those of Earth and Jupiter.

The eigenvibration of Saturn's inner core can cause disturbances in the surrounding gravitational field. Therefore, the density of Saturn's rings is affected not only by the moons but also by changes in Saturn's own gravitational field.

The Cassini measurements find that the Saturn kilometric radiation periods of Saturn's southern and northern hemispheres have a slight difference of around 10 min, and the periods change with time.

 In view of the perfect coincidence of Saturn's magnetic and spin axes, the related mechanism is different from those of Jupiter and Earth with tilted magnetic axes rotating around their respective spin axes and thus magnetospheres wobbling at the same time.

 A hexagonal structure at Saturn's north pole was first discovered by Voyager in 1981. Between 2012 and 2016, Cassini found that the color of the hexagon changed from bluish to golden possibly due to a variation in atmospheric composition caused by seasonal change.

Located on Saturn's equatorial plane, the rings are only 5 m thick. They are composed mainly of water ice, which may be discolored by contamination due to meteoroid collisions.

Giant planets' magnetospheres present a different dynamic convection mode compared to Earth's solar wind-driven magnetosphere. For the rapidly rotating magnetospheres with abundant internal plasma sources, such as Jovian and Saturnian magnetosphere. Centrifugal force dominates the magnetosphere dynamics and forms the Vasyliunas cycle.

Saturn has the most moons (82 moons) that have been confirmed among the 8 planets in the solar system. Titan is the largest moon in the Saturn system and the second-largest moon in the solar system. One mission determined for Saturn system exploration is NASA's Dragonfly aiming at landing on Titan to search for environmental and chemical changes suitable for biological survival.

3.Research Advances in Asteroids

Japan's Hayabusa-1 was launched in 2003. This launch sent the Hayabusa probe to the near-Earth S-type asteroid 25143 Itokawa and collected asteroid samples (at least 1,534 grains), which were returned to Earth in November 2010.

Following the successful sample return of Hayabusa-1, Japan launched Hayabusa-2 in December 2014 to collect samples and conduct impact experiments on the C-type asteroid Ryugu. Hayabusa-2 successfully collected a 5.4-g sample and returned it to Earth in December 2020. Its close exploration of Ryugu has also yielded important results. The surface of Ryugu is found to be covered with a large number of boulders, rather than the centimeter-scale particles presumed previously by telescopic thermal infrared observations. These boulders possess low tensile strength, which more susceptible to destruction upon Earth's atmosphere entry, and explains why few C-class asteroid-associated meteorites are found on Earth.

The US OSIRIS-REx probe aims to study Bennu, a near-Earth asteroid. It successfully obtained samples on Bennu in October 2020 and is expected to return them to Earth in 2023. This mission will dramatically improve our understanding of the physicochemical properties, orbital dynamics, and thermal properties of the near-surface composition of carbonaceous asteroids. Bennu has a very rough surface with a non-uniform distribution of boulders of different sizes. This result changes the understanding of their weathered surfaces. It requires to evaluate the surface properties of asteroids obtained by ground-based observations with thermal analysis and radar polarization ratio methods.

In addition, the author briefly presents the results of comet 67P in terms of comet nucleus shape, water and organic content, and gas production rate, and made some comments and suggestions on the detection objectives and detection formats for future asteroid missions.

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JOURNAL

Space: Science & Technology

DOI

10.34133/space.0007 

ARTICLE TITLE

Highlight Advances in Planetary Physics in the Solar System: In Situ Detection Over the Past 20 Years

Flower power: Research highlights the role of ants in forest regeneration

Peer-Reviewed Publication

BINGHAMTON UNIVERSITY

 

IMAGE: CARMELA BUONO, A PHD CANDIDATE IN BIOLOGICAL SCIENCES, PHOTOGRAPHED AT THE NATURE PRESERVE AT BINGHAMTON UNIVERSITY, STATE UNIVERSITY OF NEW YORK. view more 

CREDIT: BINGHAMTON UNIVERSITY, STATE UNIVERSITY OF NEW YORK

BINGHAMTON, N.Y. -- Ants play a key role in forest regeneration, according to a new paper from Binghamton University, State University of New York.

Walk through an old growth forest in early spring, and you’ll be dazzled by wildflowers, their jewel-like tones shining from the forest floor.

But in newer forests, spring ephemerals such as trillium, wild ginger, violets and bloodroot are in shorter supply. The reason may lie with some less-flashy forest residents: Aphaenogaster sp., or the woodland ant.

“Not a lot of people have heard of them, but they are the powerhouse of moving seeds and called ‘keystone dispersers,’” explained Carmela Buono, a Binghamton University doctoral candidate in biological sciences. 

More than 95% of New York state forests — including the Binghamton University Nature Preserve — are secondary forests, which sprung up on land once cleared for agriculture. While parts of these regenerated forests, such as the overstory, have recovered well, they are missing other aspects of biodiversity — particularly when it comes to understory plants such as native wildflowers.

Many plant species rely on a mutual relationship with ants to disperse their seeds. In fact, northeastern North America is one of the major hotspots of ant-plant mutualism, although it also happens in parts of Europe, Australia, South Africa and in northeastern Asia, Buono said.

“These plants evolved with seeds that have an appendage rich in fats attached to them, and that’s very attractive to woodland ants,” she said. “Ants need fats just as much as protein and sugar, and it’s hard to find foods rich in fats in the forest.”

Shiny black and medium-sized, woodland ants are a native species that lives in logs, forest leaf litter and underneath rocks. Woodland ants take the seeds with fatty rewards back to their nests, protecting them from consumption by rodents and other organisms. Once the fatty appendages are consumed, the ants — in a kind of insect housekeeping — remove the seeds from the nest, dispersing them far from the original plant. It’s a mutually beneficial arrangement.

“There are so many interesting, intricate parts of this interaction depending on the types of seeds ants prefer, so you can get this beautiful mixing of flower species in forests,” Buono said.

How are old growth forests different?

Old growth forests are rare treasures that play an important role in preserving species diversity, Buono pointed out. Pockets of the Northeast’s ancient forest cover remain in some areas, often on land deemed unsuitable for farming.

They differ from secondary forests literally starting at the ground level. Ground previously cleared for agriculture is flat, whereas old growth forests have a “pit and mound” topography.

“It’s uneven, from years and years of trees falling over,” Buono explained.

The pits are left from the roots of toppled trees lifted out of the ground, while mounds result from the extracted root and soil. Species within the two types of forest are also different, with quick colonizers moving into younger woodlands. An established forest often features a greater number of shade-tolerant plants in the understory.

There are slightly fewer woodland ants in secondary forests, perhaps owing to their displacement during years of agricultural use. Differences in forest canopies and the amount of light that reaches the forest floor could also play a role, but that has yet to be explored, Buono said.

The real issue appears to be competition with invasive slugs, which are found largely in the regenerated woodlands and also have a taste for fatty seed appendages. Slugs often prefer forest edges, and secondary forests may be located closer to habitats that slugs prefer, such as open meadows or active farms, Buono said.

To restore newer forests to a healthier state, we need to look beyond the trees to the diversity of insects, which play a crucial role in the forest ecosystem, according to the researchers.

“Ants are beneficial. They’re not as charismatic as butterflies or bees that help pollinate flowers, but they are just as important,” Buono said.

A white trillium flower growing in the woods

Woodland ants play an important role in dispersing seeds

CREDIT

Carmela BuonoJOURNAL

Ecology

DOI

10.1002/ecy.3978 

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Historical forest disturbance results in variation in functional resilience of seed dispersal mutualisms

NO MENTION IF COPPER INFUSED

Compression treatment could relieve horses’ painful swollen limbs

Peer-Reviewed Publication

NORTH CAROLINA STATE UNIVERSITY

 

IMAGE: EQ PRESS view more 

CREDIT: ROB UNDERHILL PRODUCTIONS

Researchers from North Carolina State University have taken technology aimed at helping humans suffering from lymphedema – in which the accumulation of excess lymph fluid causes swollen limbs – and developed a medical device to aid horses suffering from the same condition. In a pilot study the device, called the EQ Press, was successful in moving fluid up the limbs and into the lymph nodes. This could lead to relief for horses with chronic conditions, as well as with temporary swelling due to injury or inactivity.

“Across the board, horses are predisposed to lower limb swelling,” says Lauren Schnabel, associate professor of equine orthopedic surgery at NC State and study co-author. “Lymphatic flow is driven by muscle contractions that circulate lymph fluid through the lymphatic system – horses are prone to lymphatic issues because they have very little musculature in the lower limbs.”

The severity of the condition can vary widely – from temporary swelling due to curtailed mobility, to lymphangitis caused by infections that can scar the lymphatic system. Owners will usually treat the condition by wrapping the limbs and icing them while encouraging exercise. But the effects of these treatments are usually only temporary.

“Humans suffer from the exact same type of lymphedema horses do, but the difference is that human medicine has a very effective treatment option – pneumatic compression devices,” Schnabel says. “So we wanted to create a horse-specific version of those devices and see if it would be similarly effective.”

Working closely with a company that manufactures human pneumatic compression devices, Schnabel developed the EQ Press in collaboration with former NC State veterinary student Irina Perdew.

The full EQ Press system comprises custom garments designed to accommodate the front and rear limbs of horses. Powered by pumps that tuck into a saddle pad, the device creates cycles of dynamic pressure waves that start at the bottom of the limb and move up, forcing fluid up the limb and eliminating backflow.

“There was anecdotal data that indicated compression treatment worked well for horses, but we wanted scientific evidence that demonstrates the utility of pneumatic compression for such large animals,” Schnabel says. “So we designed the NC State pilot study.”

In the study, six healthy thoroughbreds were injected with a tracer isotope in their lower front limbs – a harmless sulfur colloid that is taken up and excreted through the lymphatic system. A specialized camera followed the progression of the isotope up the lymphatic system and into a lymph node in the upper limb, a process known as lymphoscintigraphy.

Each horse underwent lymphoscintigraphy twice – once with treatment by the EQ Press on the front limbs and once without – randomized between treatment and control.

In all of the EQ Press treated horses, the camera showed the tracer isotope moving from the lower limb to the lymph node in the upper limb within a 60-minute window. Of the control horses, only one showed that the tracer isotope was able to reach the lymph node.

Overall, EQ Press treated horses had significantly accelerated lymphatic flow compared to untreated horses, recorded as both time to move out of the lower limb and also as time to reach the lymph node in the upper limb.

Schnabel and the research team found the results encouraging and want to determine whether pneumatic compression treatment will be as helpful for horses as it is for humans.

“Now we have compelling evidence that pneumatic compression treatments can accelerate lymphatic flow in healthy horses,” Schnabel says. “Our next step is to study the effectiveness of the EQ Press for treatment of horses with medical conditions such as lymphedema.”

The study appears in the American Journal of Veterinary Research. Drew Koch, postdoctoral fellow at NC State, is corresponding author of the work. Schnabel is co-founder and chief medical officer of Vetletics, Inc., the company that manufactures the EQ Press.

-peake-

Note to editors: An abstract follows.

“Pneumatic compression therapy using the EQ Press accelerates lymphatic flow in healthy equine forelimbs as determined by lymphoscintigraphy”

DOI: doi.org/10.2460/ajvr.22.12.0214

Authors: Drew Koch, Lauren Schnabel, Justin Reynolds, Clifford Berry, North Carolina State University
Published: Online Feb. 21, 2023 in the American Journal of Veterinary Research

Abstract:
OBJECTIVE
Limb lymphedema in horses can be debilitating and painful. Pneumatic compression therapy has shown significant benefits for people suffering from lymphedema. The objective of this study was to determine the effect of a novel, equine-specific pneumatic compression device on the lymphatic flow of healthy horse forelimbs as determined by Tc-99m sulfur colloid lymphoscintigraphy.
ANIMALS
Six healthy Thoroughbreds.
PROCEDURES
In a randomized crossover design, horses underwent bilateral forelimb lymphoscintigraphy following subcutaneous injection of Tc-99m sulfur colloid at the coronary band as untreated control or with pneumatic compression therapy using the EQ Press. Lateral, static images were obtained of the distal limb (time 0 to 60 minutes) and proximal limb (time 30 to 60 minutes) using a standard gamma camera. Lymphatic flow was determined by assigning a score to the time point at which Tc-99m sulfur colloid was first visualized at the level of the accessory carpal bone (1 to 7) in the distal limb and the cubital lymph node (1 to 4) in the proximal limb.
RESULTS
EQ Press treatment led to a significantly faster lymphatic flow of Tc-99m sulfur colloid to the predetermined anatomic locations of the accessory carpal bone (P = .002) in the distal limb and the cubital lymph node (P = .001) in the proximal limb.
CLINICAL RELEVANCE
Pneumatic compression therapy as provided by an equine-specific device encouraged lymphatic flow in healthy, nonedematous equine forelimbs. These data support further study of the EQ Press for pneumatic compression therapy in horses clinically affected by lymphedema and lymphatic drainage disorders.

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JOURNAL

American Journal of Veterinary Research

DOI

10.2460/ajvr.22.12.0214 

METHOD OF RESEARCH

Randomized controlled/clinical trial

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Pneumatic compression therapy using the EQ Press accelerates lymphatic flow in healthy equine forelimbs as determined by lymphoscintigraphy

ARTICLE PUBLICATION DATE

27-Feb-2023

COI STATEMENT

LVS is a cofounder and Chief Medical Officer of Vetletics Inc, which supplied the EQ Press for this study.

HIV reservoirs are established earlier than expected

Peer-Reviewed Publication

UNIVERSITY OF MONTREAL HOSPITAL RESEARCH CENTRE (CRCHUM)

 

IMAGE: NICOLAS CHOMONT (RIGHT), A CRCHUM RESEARCHER AND PROFESSOR AT UNIVERSITÉ DE MONTRÉAL, WITH PIERRE GANTNER, A FORMER POSTDOCTORAL STUDENT IN CHOMONT’S LAB AND THE STUDY’S FIRST AUTHOR view more 

CREDIT: CHUM

Montreal, February 28, 2023—For the first time in humans, a research team has shown that, as early as the first days of infection, HIV is able to create reservoirs where it will hide and persist during antiretroviral therapy.

Until now, the scientific community did not know exactly when or how these viral reservoirs—the existence of which is a major obstacle to curing HIV—are established in human beings.

In a study published in the journal Immunity, scientists led by Nicolas Chomont, a researcher at the CHUM Research Centre (CRCHUM) and professor at Université de Montréal, found that a small fraction of the virus integrates into the genome of CD4+ T cells in the very first weeks of infection (the acute phase), but does not replicate there. It therefore escapes the notice of the fastest diagnostic tool to date, which detects active viral replication.

CD4+ T cells are HIV’s primary targets. They are white blood cells responsible for activating the human body’s defence against infections.

“With the help of an analysis technique developed in our laboratory, we were able to observe and count the T cells infected by the virus in human samples collected in the earliest stages of the infection,” said Chomont, the study’s principal author. “We succeeded in detecting the presence of the virus through sequencing even when it was hidden in cells that weren’t participating in viral replication.”

To study these initial phases of the spread of the virus, Pierre Gantner, a former postdoctoral student in Chomont’s lab and the study’s first author, had access to samples of blood and inguinal lymph node tissue from 25 people in the first acute-infection cohort of the U.S. Military HIV Research Program in Thailand.

This cohort, RV254/SEARCH010, was launched more than 10 years ago in collaboration with the Thai Red Cross AIDS Research Centre and has enrolled nearly 800 volunteers. Chomont and his team have been closely cooperating with their colleagues in Thailand since its launch.

 

Mapping the types of infected cells

Through their analysis technique, the CRCHUM scientists succeeded in counting the CD4+ T cells infected by the virus during the acute phase of the infection.

These infected cells increased in number from 10 to 1,000 per million CD4+ T cells in less than seven days, thereby showing the extreme speed with which HIV spreads.

The scientists also observed that the characteristics of the cells targeted by HIV in the first weeks of the infection varied quickly and differed depending on whether they were located in the blood or lymph nodes.

“For example, we noticed that few Tfh—T follicular helper cells—are infected by the virus during the acute phase of the infection,” said Chomont. “Since they play a crucial role in viral replication, the scientific community thought that they were the first to be infected.”

“In fact, we counted a lot more [infected Tfh] during the chronic phase of the disease, which is about two months after infection. At that point, they are actively contributing to the development of the disease.”

Until now, these types of studies have been carried out on animal models. Therefore, this is the first time that the early stages of the infection in humans have been described so precisely.

 

Destabilizing the reservoirs

A large part of global research dedicated to the study of HIV focuses on how to reactivate the virus lying dormant in the reservoirs in order to neutralize it.

“’The earlier we start antiretroviral therapy, the more we prevent the virus from replicating and the more we limit the size of the reservoirs. We proved that in 2020,“ said Chomont.

“However, it seems clear that early antiretroviral therapy should be combined with another treatment to force the virus out of its hiding places, because at the time of diagnosis latent reservoirs will have already been established in people infected with HIV.”

In collaboration with scientists from the United States, Chomont’s research team is currently evaluating whether this type of treatment administered in the acute infection phase would prevent the establishment of viral reservoirs.

 

Science writing: Bruno Geoffroy

 

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About this study

“HIV rapidly targets a diverse pool of CD4+ T cells to establish productive and latent infections” by Pierre Gantner et al., was published online Feb. 17, 2023, in Immunity.

The study was funded by the U.S. Military HIV Research Program, Walter Reed Army Institute of Research; the Foundation for AIDS Research (amfAR Research Consortium on HIV Eradication); the Canadian Institutes of Health Research; the Canadian HIV Cure Enterprise (CanCURE); the AIDS and Infectious Diseases Network of the Fonds de Recherche du Québec-Santé; the Thai Red Cross Research Center; and, in part, the U.S. National Institutes of Health (NIH).

 

About the CRCHUM

The CHUM Research Centre (CRCHUM) is one of North America’s leading hospital research centres. It strives to improve the health of adults through a continuum of research spanning disciplines such as basic science, clinical research and population health. More than 2,150 people work at the CRCHUM, including nearly 500 researchers and nearly 650 students and postdoctoral fellows. crchum.com

About Université de Montréal 

Deeply rooted in Montréal and dedicated to its international mission, Université de Montréal is one of the top universities in the French-speaking world. Founded in 1878, Université de Montréal today has 13 faculties and schools, and together with its two affiliated schools, HEC Montréal and Polytechnique Montréal, constitutes the largest centre of higher education and research in Quebec and one of the major centres in North America. It brings together 2,300 professors and researchers and has 70,000 students. umontreal.ca 

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JOURNAL

Immunity

DOI

10.1016/j.immuni.2023.01.030 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Human tissue samples

ARTICLE TITLE

HIV rapidly targets a diverse pool of CD4+ T cells to establish productive and latent infections

Study finds association between lifetime experiences of discrimination and incidence of dementia

Peer-Reviewed Publication

ATRIUM HEALTH WAKE FOREST BAPTIST

 

IMAGE: MIKE BANCKS, PH.D., M.P.H., ASSISTANT PROFESSOR OF EPIDEMIOLOGY AND PREVENTION AT WAKE FOREST UNIVERSITY SCHOOL OF MEDICINE view more 

CREDIT: WAKE FOREST UNIVERSITY SCHOOL OF MEDICINE

WINSTON-SALEM, N.C. – Feb. 28, 2023 – According to new research from Wake Forest University School of Medicine, people who experience discrimination during their lifetimes have an increased risk of dementia.

The study appears in the February issue of Alzheimer’s & Dementia, the journal of the Alzheimer’s Association.

“We need a better understanding of how experiences of discrimination impact health and dementia risk as well as racial/ethnic disparities in dementia,” said Mike Bancks, Ph.D., M.P.H., assistant professor of epidemiology and prevention at Wake Forest University School of Medicine and corresponding author of the study.

In the study, researchers assessed data from the Multi-Ethnic Study of Atherosclerosis (MESA), a medical research study involving more than 6,500 men and women from six communities in the United States—Baltimore; Chicago; Forsyth County, North Carolina; Los Angeles; New York City; and St. Paul, Minn. Participants were contacted by telephone annually and invited to participate in five follow-up in-person clinic examinations from 2000 to 2018.

The research team gathered data from self-reported experiences of lifetime and everyday discrimination. For the lifetime discrimination scale, participants were asked whether they had been treated unfairly in six domains such as being denied a promotion or treated unfairly by police. Participants were also asked to indicate the perceived reason for the unfair treatment such as race, religion, gender, physical appearance, income or sexual orientation.

For the everyday discrimination scale, participants were asked to indicate the frequency with which certain experiences of unfair treatment occur in their day-to-day life.

The prevalence of experiencing any lifetime discrimination was 42% across all MESA participants and higher among Black adults at 72% with experiences of discrimination. Over a median of 15.7 years of follow-up, there were 466 incident cases of dementia. Individuals reporting lifetime discrimination in more than two domains (compared to none) had a greater risk for dementia.

“Our findings suggest an association between greater experiences of discrimination during one’s lifetime and higher risk for dementia,” Bancks said. “In alignment with other MESA findings, it’s clear that Black adults bear an unequal burden of exposure to discrimination, and discrimination is harmful to health.”

Researchers also noted that the strength of association between discrimination and dementia did not appear to differ by race/ethnicity.

According to Bancks, there are a few potential mechanisms that may link experiences of lifetime discrimination to cognitive impairment such as chronic stress, receiving inadequate or delayed health care, and undiagnosed or untreated high blood pressure, but additional research is needed.

“Future studies should assess how the accumulation of experiences of discrimination are related to dementia risk to help guide strategies to intervene on discrimination and dementia risk,” Bancks said.

This study was supported by National Heart, Lung and Blood Institute grants R01HL127659, 75N92020D00001, HHSN268201500003I, N01-HC-95159, 75N92020D00005, N01-HC-95160, 75N92020D00002, N01-HC-95161, 75N92020D00003, N01-HC-95162, 75N92020D00006, N01-HC-95163, 75N92020D00004, N01-HC-95164, 75N92020D00007, N01-HC-95165, N01-HC-95166, N01-HC-95167, N01-HC-95168 and N01-HC-95169; the National Center for Advancing Translational Sciences grants UL1-TR-000040, UL1-TR-001079 and UL1-TR-001420; and by National Institute on Aging grants R01AG054069 and 1RF1AG054474. 

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JOURNAL

Alzheimer s & Dementia

DOI

10.1002/alz.12947 

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Self-reported experiences of discrimination and incident dementia