Understanding what contributes to patients’ inactivity is the focus of a world first study from the University of South Australia. Here, researchers have found that people with knee OA unconsciously believe that activity may be dangerous to their condition, despite medical advice telling them otherwise.

The study found that of those surveyed, 69% of people with knee pain had stronger implicit (unconscious) beliefs that exercise was dangerous than the average person without pain.

It’s an interesting finding that not only highlights the conflicted nature of pain and exercise, but also that what people say and what people think, deep down, may be entirely different things.

Lead researcher, and UniSA PhD candidate based at SAHMRI, Brian Pulling, says the research provides valuable insights for clinicians treating people with knee OA.

“Research shows that physical activity is good for people with knee OA, but most people with this condition do not move enough to support joint or general health,” Pulling says.

“To understand why people with OA might not be active, research studies typically use questionnaires to assess fear of moving. But unfortunately, questionnaires are limited — what we feel deep down (and how our system naturally reacts to something that is threatening) may be different to what we report. And we still know that many people are avoiding exercise, so we wanted to know why.”

To assess this, the researchers developed a tool that can detect and evaluate people’s implicit beliefs about exercise; that is, whether they unconsciously think activity is dangerous for their condition.

“We found that that even among those who said they were not fearful about exercise, they held unconscious beliefs that movement was dangerous,” Pulling says.

“Our research shows that people have complicated beliefs about exercise, and that they sometimes say one thing if asked directly yet hold a completely different implicit belief.

“People are not aware that what they say doesn’t match what they choose on the new task; they are not misrepresenting their beliefs.

“This research suggests that to fully understand how someone feels about an activity, we must go beyond just asking directly, because their implicit beliefs can sometimes be a better predictor of actual behaviour than what people report. That’s where our tool is useful.”

The online implicit association test presents a series of words and images to which a participant must quickly associate with being either safe or dangerous. The tool intentionally promotes instant responses to avoid deliberation and other influencing factors (such as responding how they think they should respond).

Associate Professor Tasha Stanton says that the new tool has the potential to identify a group of people who may have challenges increasing their activity levels and undertaking exercise.

“What people say and what people do are often two different things, Assoc Prof Stanton says.

“Having access to more accurate and insightful information will help health professionals better support their patients to engage with activity and exercise. It may also open opportunities for pain science education, exposure-based therapy, or cognitive functional therapy…things that would not usually be considered for someone who said that they were not scared to exercise.”

Researchers are now looking to see if implicit beliefs are directly associated with behaviour and are asking for people to complete the Implicit Association Test (takes seven minutes). At the end of the test participants are given their results in comparison to the rest of the population.

To take the test, please click here: https://unisasurveys.qualtrics.com/jfe/form/SV_0OZKUqzBNtiKGF0

A team of researchers led by University of Wisconsin-Madison astronomy professor Catherine Grier and recent graduate Robert Wheatley revealed the accelerating gas using years of data collected from a quasar, a particularly bright and turbulent kind of black hole, billions of light years away in the constellation Boötes. They presented their findings today at the 244th meeting of the American Astronomical Society in Madison.

Scientists believe black holes are situated at the center of most galaxies. Quasars are supermassive black holes surrounded by disks of matter being pulled in by the black hole’s enormous gravitational power.

“The material in that disk is always falling into the black hole, and the friction of that pulling and pulling heats up the disk and makes it very, very hot and very, very bright,” says Grier. “These quasars are really luminous, and because there’s a large range of temperatures from the interior to the far parts of the disk, their emission covers almost all of the electromagnetic spectrum.”

The bright light makes quasars nearly as old as the universe (as many as 13 billion light years away) visible, and the broad range of their radiation makes them particularly useful for astronomers to probe the early universe.

Researchers used more than eight years of observations of a quasar called SBS 1408+544, collected by a program carried out by the Sloan Digital Sky Survey now known as the Black Hole Mapper Reverberation Mapping Project. They tracked winds composed of gaseous carbon by spotting light from the quasar that was missing — light that was being absorbed by the gas. But instead of being absorbed at exactly the right spot in the spectrum that would indicate carbon, the shadow shifted farther from home with every new look at SBS 1408+544.

“That shift tells us the gas is moving fast, and faster all the time,” says Wheatley. “The wind is accelerating because it’s being pushed by radiation that is blasted off of the accretion disk.”

Scientists, including Grier, have suggested they’ve observed accelerating winds from black hole accretion disks before, but this had not yet been backed by data from more than a few observations. The new results came from about 130 observations of SBS 1408+544 made over nearly a decade, which allowed the team to solidly identify the increase in velocity with high confidence.

The winds pushing gas out from the quasar are of interest to astronomers because they are a way in which the supermassive black holes might influence the evolution of the galaxies that surround them.

“If they’re energetic enough, the winds may travel all the way out into the host galaxy, where they could have a significant impact,” Wheatley says.

Depending on the circumstances, a quasar’s winds could supply pressure that squeezes gas together and speeds the birth of a star in its host galaxy. Or it could scour away that fuel and keep a potential star from forming.

“Supermassive black holes are big, but they’re really tiny compared to their galaxies,” says Grier, whose work is supported by the National Science Foundation. “That doesn’t mean they can’t ‘talk’ to each other, and this is a way for one to talk to the other that we will have to account for when we model the effects of these kinds of black holes.”

The study of SBS 1408+544, published today in The Astrophysical Journal included collaborators at York University, Pennsylvania State University, University of Arizona and others.

This research was funded in part by grants from the National Science Foundation (AST-2310211 and AST-2309930).

The research comprises two papers, one published in The Astrophysical Journal in April 2024, and one as yet unpublished that will be submitted to the same journal. The results will be presented at the 244th meeting of the American Astronomical Society, held June 9 through June 13 at the Monona Terrace Convention Center in Madison, Wisconsin. 

“Supermassive black holes in galaxy centers have millions-to-billions of times the mass of the Sun,” said Fan Zou, a graduate student at Penn State and first author of the papers. “How do they become such monsters? This is a question that astronomers have been studying for decades, but it has been difficult to track all the ways black holes can grow reliably.”

Supermassive black holes grow through a combination of two main channels. They consume cold gas from their host galaxy — a process called accretion — and they can merge with other supermassive black holes when galaxies collide.

“During the process of consuming gas from their hosting galaxies, black holes radiate strong X-rays, and this is the key to tracking their growth by accretion,” said W. Niel Brandt, Eberly Family Chair Professor of Astronomy and Astrophysics and professor of physics at Penn State and a leader of the research team. “We measured the accretion-driven growth using X-ray sky survey data accumulated over more than 20 years from three of the most powerful X-ray facilities ever launched into space.”

The research team used complementary data from NASA’s Chandra X-ray Observatory, the European Space Agency’s X-ray Multi-Mirror Mission-Newton (XMM-Newton), and the Max Planck Institute for Extraterrestrial Physics’ eROSITA telescope. In total, they measured the accretion-driven growth in a sample of 1.3 million galaxies that contained over 8,000 rapidly growing black holes.

“All of the galaxies and black holes in our sample are very well characterized at multiple wavelengths, with superb measurements in the infrared, optical, ultraviolet, and X-ray bands,” Zou said. “This allows for robust conclusions, and the data show that, at all cosmic epochs, more massive galaxies grew their black holes by accretion faster. With the quality of the data, we were able to quantify this important phenomenon much better than in past works.”

The second way that supermassive black holes grow is through mergers, where two supermassive black holes collide and merge together to form a single, even more massive, black hole. To track growth by mergers, the team used IllustrisTNG, a set of supercomputer simulations that model galaxy formation, evolution, and merging from shortly after the Big Bang until the present.

“In our hybrid approach, we combine the observed growth by accretion with the simulated growth through mergers to reproduce the growth history of supermassive black holes,” Brandt said. “With this new approach, we believe we have produced the most realistic picture of the growth of supermassive black holes up to the present day.”

The researchers found that, in most cases, accretion dominated black-hole growth. Mergers made notable secondary contributions, especially over the past 5 billion years of cosmic time for the most-massive black holes. Overall, supermassive black holes of all masses grew much more rapidly when the Universe was younger. Because of this, the total number of supermassive black holes was almost settled by 7 billion years ago, while earlier in the Universe many new ones kept emerging.

“With our approach, we can track how central black holes in the local universe most likely grew over cosmic time,” Zou said. “As an example, we considered the growth of the supermassive black hole in the center of our Milky Way Galaxy, which has a mass of 4 million solar masses. Our results indicate that our Galaxy’s black hole most likely grew relatively late in cosmic time.”

In addition to Zou and Brandt, the research team includes Zhibo Yu, graduate student at Penn State; Hyungsuk Tak, assistant professor of statistics and of astronomy and astrophysics at Penn State; Elena Gallo at the University of Michigan; Bin Luo at Nanjing University in China; Qingling Ni at the Max Planck Institute for Extraterrestrial Physics in Germany; Yongquan Xue at the University of Science and Technology of China; and Guang Yang at the University of Groningen in the Netherlands.

Funding from the U.S. National Science Foundation, the Chandra X-ray Center, and Penn State supported this work. The work was also made possible by the sharing of the IllustrisTNG simulation results with the scientific community.

One of the most common reasons for bypassing the COVID vaccine is concern about side effects like tiredness, muscle and joint pain, chills, headache, fever, nausea and feeling generally unwell. But a new study, led by UC San Francisco, has found that the symptoms indicate a robust immune response that is likely to lessen the chances of infection.

The study, which appears online June 10 in Annals of Internal Medicine, is based on symptom reports and antibody responses from 363 people, who had the Pfizer-BioNTech or Moderna mRNA vaccines when they were first introduced.

After the second dose of the vaccine, the researchers found that those with seven or more symptoms had nearly double the antibody levels of those who did not have symptoms. The participants were mainly in their forties to sixties and had not had the virus.

About 40% of the people in the study also wore a device to monitor their temperature, breathing and heart rate. The researchers found that those whose skin temperature increased by 1 degree Celsius after the second dose had three times the antibody levels six months later, compared to those whose temperature did not increase.

An absence of side effects does not mean the vaccine is not working

“Generally, we found that the higher the number of side effects, the higher the level of antibodies,” said first author Ethan Dutcher, MD, PhD, a postdoctoral researcher in the UCSF Department of Psychiatry and Behavioral Sciences, and the Weill Institute for Neurosciences. “But this wasn’t a hard rule: some people without side effects had better antibodies than some people with side effects.”

As the virus has evolved and fatality rates have fallen, many people are underestimating its impact. “The toll of COVID is still high for some — sickness, lost work, lasting fatigue and the dreaded long COVID,” said co-senior author Elissa Epel, PhD, a vice chair in the UCSF Department of Psychiatry and Behavioral Sciences. “While the symptoms from vaccination can be very unpleasant, it’s important to remember that they don’t come close to the disease’s potential complications,” she said.

“With COVID-19 vaccines likely here to stay, identifying what predicts a strong antibody response will remain important,” said co-senior author Aric Prather, PhD, professor in the UCSF Department of Psychiatry and Behavioral Sciences.

The latest recommendations from the Centers for Disease Control and Prevention are that everyone 6 months and older should receive the updated vaccine, and those 65 and older should receive an additional dose.

Co-Authors: Ashley Mason, PhD, and Frederick Hecht, MD, of UCSF; James E. Robinson, MD, of Tulane University; and Stacy Drury, MD, PhD, of Tulane University and Boston Children’s Hospital.

Funding: National Institutes of Health (R24AG048024, 5U24AG066528 and U54CA260581).

Disclosures: Epel is on the scientific advisory boards of Meru Health and Oura Health. Mason has receiving consultancy fees from Oura Health. Prather is an advisor to NeuroGeneces and L-New Co.

Thanks to the efforts of a citizen science project called Backyard Worlds: Planet 9 and a team of astronomers from around the country, a rare hypervelocity L subdwarf star has been found racing through the Milky Way. More remarkably, this star may be on a trajectory that causes it to leave the Milky Way altogether. The research, led by University of California San Diego Professor of Astronomy and Astrophysics Adam Burgasser, was presented today at a press conference during the 244^th national meeting of the American Astronomical Society (AAS) in Madison, Wisconsin.

The star, charmingly named CWISE J124909+362116.0 (“J1249+36”), was first noticed by some of the over 80,000 citizen science volunteers participating in the Backyard Worlds: Planet 9 project, who comb through enormous reams of data collected over the past 14 years by NASA’s Wide-field Infrared Survey Explorer (WISE) mission. This project capitalizes on the keen ability of humans, who are evolutionarily programmed to look for patterns and spot anomalies in a way that is unmatched by computer technology. Volunteers tag moving objects in data files and when enough volunteers tag the same object, astronomers investigate.

J1249+36 immediately stood out because of the speed at which it is moving across the sky, initially estimated at about 600 kilometers per second (1.3 million miles per hour). At this speed, the star is fast enough to escape the gravity of the Milky Way, making it a potential “hypervelocity” star.

To better understand the nature of this object, Burgasser turned to the W.M. Keck Observatory in Maunakea, Hawaii to measure its infrared spectrum. These data revealed that the object was a rare L subdwarf — a class of stars with very low mass and temperature. Subdwarfs represent the oldest stars in the Milky Way.

The insight into J1249+36’s composition was made possible by a new set of atmosphere models created by UC San Diego alumnus Roman Gerasimov, who worked with UC LEADS scholar Efrain Alvarado III to generate models specifically tuned to study L subdwarfs. “It was exciting to see that our models were able to accurately match the observed spectrum,” said Alvarado, who is presenting his modeling work at the AAS meeting.

The spectral data, along with imaging data from several ground-based telescopes, allowed the team to accurately measure J1249+36’s position and velocity in space, and thereby predict its orbit through the Milky Way. “This is where the source became very interesting, as its speed and trajectory showed that it was moving fast enough to potentially escape the Milky Way,” stated Burgasser.

What gave this star a kick?

Researchers focused on two possible scenarios to explain J1249+36’s unusual trajectory. In the first scenario, J1249+36 was originally the low-mass companion of a white dwarf. White dwarfs are the remnant cores of stars that have depleted their nuclear fuel and died out. When a stellar companion is in a very close orbit with a white dwarf, it can transfer mass, resulting in periodic outbursts called novae. If the white dwarf collects too much mass, it can collapse and explode as a supernova.

“In this kind of supernova, the white dwarf is completely destroyed, so its companion is released and flies off at whatever orbital speed it was originally moving, plus a little bit of a kick from the supernova explosion as well,” said Burgasser. “Our calculations show this scenario works. However, the white dwarf isn’t there anymore and the remnants of the explosion, which likely happened several million years ago, have already dissipated, so we don’t have definitive proof that this is its origin.”

In the second scenario, J1249+36 was originally a member of a globular cluster, a tightly bound cluster of stars, immediately recognizable by its distinct spherical shape. The centers of these clusters are predicted to contain black holes of a wide range of masses. These black holes can also form binaries, and such systems turn out to be great catapults for any stars that happen to wander too close to them.

“When a star encounters a black hole binary, the complex dynamics of this three-body interaction can toss that star right out of the globular cluster,” explained Kyle Kremer, an incoming Assistant Professor in UC San Diego’s Department of Astronomy and Astrophysics. Kremer ran a series of simulations and found that on rare occasions these kinds of interactions can kick a low-mass subdwarf out of a globular cluster and on a trajectory similar to that observed for J1249+36.

“It demonstrates a proof of concept,” said Kremer, “but we don’t actually know what globular cluster this star is from.” Tracing J1249+36 back in time puts it in a very crowded part of the sky that may hide undiscovered clusters.

To determine whether either of these scenarios, or some other mechanism, can explain J1249+36’s trajectory, Burgasser said the team hopes to look more closely at its elemental composition. For example, when a white dwarf explodes, it creates heavy elements that could have “polluted” the atmosphere of J1249+36 as it was escaping. The stars in globular clusters and satellite galaxies of the Milky Way also have distinct abundance patterns that may reveal the origin of J1249+36.

“We’re essentially looking for a chemical fingerprint that would pinpoint what system this star is from,” said Gerasimov, whose modeling work has enabled him to measure the element abundances of cool stars in several globular clusters, work he is also presenting at the AAS meeting.

Whether J1249+36’s speedy journey was because of a supernova, a chance encounter with a black hole binary, or some other scenario, its discovery provides a new opportunity for astronomers to learn more about the history and dynamics of the Milky Way.

“Webb is a supernova discovery machine,” said Christa DeCoursey, a third-year graduate student at the Steward Observatory and the University of Arizona in Tucson. “The sheer number of detections plus the great distances to these supernovae are the two most exciting outcomes from our survey.”

DeCoursey presented these findings at the 244th meeting of the American Astronomical Society in Madison, Wisconsin.

‘A Supernova Discovery Machine’

To make these discoveries, the team analyzed imaging data obtained as part of the JWST Advanced Deep Extragalactic Survey (JADES) program. Webb is ideal for finding extremely distant supernovae because their light is stretched into longer wavelengths — a phenomenon known as cosmological redshift.

Prior to Webb’s launch, only a handful of supernovae had been found above a redshift of 2, which corresponds to when the universe was only 3.3 billion years old — just 25% of its current age. The JADES sample contains many supernovae that exploded even further in the past, when the universe was less than 2 billion years old.

Previously, researchers used NASA’s Hubble Space Telescope to view supernovae from when the universe was in the “young adult” stage. With JADES, scientists are seeing supernovae when the universe was in its “teens” or “pre-teens.” In the future, they hope to look back to the “toddler” or “infant” phase of the universe.

To discover the supernovae, the team compared multiple images taken up to one year apart and looked for sources that disappeared or appeared in those images. These objects that vary in observed brightness over time are called transients, and supernovae are a type of transient. In all, the JADES Transient Survey Sample team uncovered about 80 supernovae in a patch of sky only about the thickness of a grain of rice held at arm’s length.

“This is really our first sample of what the high-redshift universe looks like for transient science,” said teammate Justin Pierel, a NASA Einstein Fellow at the Space Telescope Science Institute (STScI) in Baltimore, Maryland. “We are trying to identify whether distant supernovae are fundamentally different from or very much like what we see in the nearby universe.”

Pierel and other STScI researchers provided expert analysis to determine which transients were actually supernovae and which were not, because often they looked very similar.

The team identified a number of high-redshift supernovae, including the farthest one ever spectroscopically confirmed, at a redshift of 3.6. Its progenitor star exploded when the universe was only 1.8 billion years old. It is a so-called core-collapse supernova, an explosion of a massive star.

Uncovering Distant Type Ia Supernovae

Of particular interest to astrophysicists are Type Ia supernovae. These exploding stars are so predictably bright that they are used to measure far-off cosmic distances and help scientists to calculate the universe’s expansion rate. The team identified at least one Type Ia supernova at a redshift of 2.9. The light from this explosion began traveling to us 11.5 billion years ago when the universe was just 2.3 billion years old. The previous distance record for a spectroscopically confirmed Type Ia supernova was a redshift of 1.95, when the universe was 3.4 billion years old.

Scientists are eager to analyze Type Ia supernovae at high redshifts to see if they all have the same intrinsic brightness, regardless of distance. This is critically important, because if their brightness varies with redshift, they would not be reliable markers for measuring the expansion rate of the universe.

Pierel analyzed this Type Ia supernova found at redshift 2.9 to determine if its intrinsic brightness was different than expected. While this is just the first such object, the results indicate no evidence that Type Ia brightness changes with redshift. More data is needed, but for now, Type Ia supernova-based theories about the universe’s expansion rate and its ultimate fate remain intact. Pierel also presented his findings at the 244th meeting of the American Astronomical Society.

Looking Toward the Future

The early universe was a very different place with extreme environments. Scientists expect to see ancient supernovae that come from stars that contain far fewer heavy chemical elements than stars like our Sun. Comparing these supernovae with those in the local universe will help astrophysicists understand star formation and supernova explosion mechanisms at these early times.

“We’re essentially opening a new window on the transient universe,” said STScI Fellow Matthew Siebert, who is leading the spectroscopic analysis of the JADES supernovae. “Historically, whenever we’ve done that, we’ve found extremely exciting things — things that we didn’t expect.”

“Because Webb is so sensitive, it’s finding supernovae and other transients almost everywhere it’s pointed,” said JADES team member Eiichi Egami, a research professor at the University of Arizona in Tucson. “This is the first significant step toward more extensive surveys of supernovae with Webb.”

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).