The Most Precise Accounting Yet of Dark Energy and Dark Matter

G299 was left over by a particular class of supernovas called Type Ia. 
Credit: NASA/CXC/U.Texas

 Astrophysicists have performed a powerful new analysis that places the most precise limits yet on the composition and evolution of the universe. With this analysis, dubbed Pantheon+, cosmologists find themselves at a crossroads.

Pantheon+ convincingly finds that the cosmos is composed of about two-thirds dark energy and one-third matter — mostly in the form of dark matter — and is expanding at an accelerating pace over the last several billion years. However, Pantheon+ also cements a major disagreement over the pace of that expansion that has yet to be solved.

By putting prevailing modern cosmological theories, known as the Standard Model of Cosmology, on even firmer evidentiary and statistical footing, Pantheon+ further closes the door on alternative frameworks accounting for dark energy and dark matter. Both are bedrocks of the Standard Model of Cosmology but have yet to be directly detected and rank among the model's biggest mysteries. Following through on the results of Pantheon+, researchers can now pursue more precise observational tests and hone explanations for the ostensible cosmos.

"With these Pantheon+ results, we are able to put the most precise constraints on the dynamics and history of the universe to date," says Dillon Brout, an Einstein Fellow at the Center for Astrophysics | Harvard & Smithsonian. "We've combed over the data and can now say with more confidence than ever before how the universe has evolved over the eons and that the current best theories for dark energy and dark matter hold strong."

Forgetting is natural, but learning how to learn can slow it down

Students studying at Iowa State University.
Credit: Christopher Gannon/Iowa State University

Whether you’re trying to ace a test or pick up a new hobby, Iowa State Psychology Professor Shana Carpenter says combining two strategies – spacing and retrieval practice – is key to success.

Carpenter is the lead author of a paper in Nature Reviews Psychology that examined more than 100 years of research on learning.

“The benefits of spacing and retrieval practice have been confirmed over and over in studies in labs, classrooms, workplaces, but the reason why we’re showcasing this research is because these two techniques haven’t fully caught on. If they were utilized all the time, we’d see drastic increases in learning,” said Carpenter.

In the paper, Carpenter and her co-authors describe spacing as a strategy to learn in small doses over time. It’s the opposite of cramming the night before an exam. In one study, medical students who received repeated surgery training over three weeks performed better and faster on tests 2 weeks and 1 year later compared to medical students who had the same training all on one day.

Carpenter says there isn’t a universal rule about how much time to schedule between practice sessions. But research shows returning to the material after forgetting some – but not all – of the content is effective.

Covid-19 is linked to increased degradation of connections between nerve cells in a new brain model

Postdoctoral fellow Samudyata and doctoral student Susmita Malwade.
Source: Karolinska Institutet

Researchers at Karolinska Institutet have used cellular reprogramming in a new study to create human three-dimensional brain models and infected them with SARS-CoV-2. In infected models, the brain's immune cells showed an excessive elimination of connections between the nerve cells. The gene expression of these cells also mimicked changes observed in neurodegenerative diseases. The results hope to identify new treatments for cognitive symptoms after Covid-19 infection.

Several studies have reported persistent cognitive symptoms following a covid-19 infection, but the underlying mechanisms for this are still unknown. The researchers behind the study, published in the journal Molecular Psychiatry, have created from human induced pluripotent stem cells (iPS) three-dimensional models of the brain in test tubes, so-called brain organoids. The model differs from previous organoid models in that they also contain microglia - the brain's immune cells. In the infected models, microglia regulated genes involved in phagocytosis, "cell-eating," the researchers could also see how microglia contained an increased amount of proteins from brain cell connections, so-called synapses. The developed model and results of the study can help guide future efforts to address cognitive symptoms in the aftermath of COVID-19 and other neuroinvasive viral infections.

Electric discharges on leaves during thunderstorms may impact nearby air quality

Weak electrical discharges, called corona, can form on tree leaves during thunderstorms
Credit: Pennsylvania State University

When thunderstorms rumble overhead, weak electrical discharges — called corona — can occur on tree leaves. A new study found coronas create large amounts of atmospheric chemicals that could impact air quality around forests, according to a team of Penn State scientists.

“While little is known about how widespread these discharges are, we estimate that coronas generated on trees under thunderstorms could have substantial impacts on the surrounding air,” said Jena Jenkins, a postdoctoral scholar in the Department of Meteorology and Atmospheric Science at Penn State.

Conditions during thunderstorms that produce lightning also create electric fields between clouds and the ground. Tall, sharply pointed objects, like leaves high in trees, enhance the electric field even further, and can lead to electrical breakdowns — or coronas, the scientists said.

“There are about two trillion trees in areas where thunderstorms are most likely to occur globally and there are 1,800 thunderstorms going on at any given time,” Jenkins said. “This is definitely a process that’s going on all the time and based on the calculations we’ve been able to do so far, we think this can affect air quality in and around forests and trees.”

Model calculates the energetics of piercing fangs, claws and other biological weapons

A new model can be used to calculate the forces involved when one organism stabs another with its puncturing tools. Pictured: A viper skull.
Photo by L. Brian Stauffer

Researchers have created a model that can calculate the energetics involved when one organism stabs another with its fangs, thorns, spines or other puncturing parts. Because the model can be applied to a variety of organisms, it will help scientists study and compare many types of biological puncturing tools, researchers said. It also will help engineers develop new systems to efficiently pierce materials or resist being pierced.

The new findings are reported in the Journal of the Royal Society Interface.

“The idea behind this was to come up with a quantitative framework for comparing a variety of biological puncture systems with each other,” said Philip Anderson, a University of Illinois Urbana-Champaign professor of evolution, ecology and behavior who led the research with postdoctoral researcher Bingyang Zhang. “An initial question of this research was how do we even measure these different systems to make them comparable.”

Algae Could be Instrumental in Making Human Exploration of Mars Possible

 A researcher working in UNLV geoscientist Elisabeth "Libby" Hausrath's lab.
Credit: University of Nevada, Las Vegas

While the world is marveling over the first images and data now coming from NASA’s Perseverance rover mission seeking signs of ancient microscopic life on Mars, a team of UNLV scientists is already hard at work on the next step: What if we could one day send humans to the Red Planet?

There’s a lot to consider when sending people, though. Human explorers, unlike their rover counterparts, require oxygen and food, for starters. It also takes about six to nine months — both ways — just in travel time. And then there’s the air itself. Martian air is roughly 98% carbon dioxide (Earth’s is a fraction of 1% for comparison) and the air temperature averages an extremely frigid -81 degrees.

It’s these challenges that UNLV geochemist and NASA Mars 2020 team scientist Libby Hausrath and postdoctoral researcher Leena Cycil, a microbial ecologist, are exploring. And a big part of the answer? Algae.

“Extremophilic algae” are types of algae known for their ability to thrive in extreme environments such as high-altitude snowy mountains or hypersaline lakes. These algae love carbon dioxide and can use it to produce oxygen. They also are edible, dense with nutrients, and grow quickly. Extremophiles’ helpful characteristics allow them to grow in some of the most inhospitable environments on Earth, possibly even in conditions similar to Mars.

New laboratory to explore the quantum mysteries of nuclear materials

INL researchers have built a laboratory around molecular beam epitaxy (MBE), a process that creates ultra-thin layers of materials with a high degree of purity and control.
Credit: Idaho National Laboratory

Replete with tunneling particles, electron wells, charmed quarks and zombie cats, quantum mechanics takes everything Sir Isaac Newton taught about physics and throws it out the window.

Every day, researchers discover new details about the laws that govern the tiniest building blocks of the universe. These details not only increase scientific understanding of quantum physics, but they also hold the potential to unlock a host of technologies, from quantum computers to lasers to next-generation solar cells.

But there’s one area that remains a mystery even in this most mysterious of sciences: the quantum mechanics of nuclear fuels.

Exploring the frontiers of quantum mechanics

Until now, most fundamental scientific research of quantum mechanics has focused on elements such as silicon because these materials are relatively inexpensive, easy to obtain and easy to work with.

Now, Idaho National Laboratory researchers are planning to explore the frontiers of quantum mechanics with a new synthesis laboratory that can work with radioactive elements such as uranium and thorium.

Ancient ocean methane not an immediate climate change threat

Researchers used a giant suction hose to collect thousands of gallons of ocean water, while on the research ship R/V Hugh Sharp. The researchers extract methane from each sample, compress the methane into cylinders, and bring the cylinders back to the lab of John Kessler, a professor of earth and environmental sciences at Rochester. From left: DongJoo Joung, a former research scientist in Kessler's lab; Kenneth Fairbarn, a research technician on the ship; Ben Riddell-Young '18; Lillian Henderson '19; and Allison Laubach '18, '19 (MS).
Credit: University of Rochester / John Kessler

New research shows reservoirs of ocean methane in mid-latitude regions will not be released to the atmosphere under warming conditions.

Deep below the ocean’s surface, the seafloor contains large quantities of naturally occurring, ice-like deposits made up of water and concentrated methane gas. For decades, climate scientists have wondered if this methane hydrate reservoir might “melt” and release massive amounts of methane to the ocean and the atmosphere as ocean temperatures warm.

New research from scientists at the University of Rochester, the US Geological Survey, and the University of California Irvine is the first to directly show that methane released from decomposing hydrates is not reaching the atmosphere.

The researchers, including John Kessler, a professor in the Department of Earth and Environmental Sciences, and DongJoo Joung, a former research scientist in Kessler’s lab and now an assistant professor in the Department of Oceanography at Pusan National University in Korea, carried out the study in mid-latitude regions—Earth’s subtropical and temperate zones.

While the stability of the methane hydrate reservoir is sensitive to changes in temperature, “in the mid-latitude regions where this study was conducted, we see no signatures of hydrate methane being emitted to the atmosphere,” says Joung, the first author of the study, published in Nature Geoscience.

Attack on 2 fronts leads ocean bacteria to require carbon boost

The study is the first to observe these complex interactions under the ocean surface: photosynthetic bacteria simultaneously infected with viruses and floating in the presence of organisms, called protists, that eat them. Photo Credit: Matt Hardy

The types of ocean bacteria known to absorb carbon dioxide from the air require more energy – in the form of carbon – and other resources when they’re simultaneously infected by viruses and face attack from nearby predators.

Viruses are abundant in the ocean, and research now suggests that marine viruses have beneficial functions, including helping to drive carbon absorbed from the atmosphere to permanent storage on the ocean floor. When viruses infect other microbes in that environment (and anywhere, in fact), the interaction results in creation of entirely new organisms called “virocells.”

In this new study, researchers worked with cyanovirocells – cyanobacteria that absorb carbon and release oxygen through photosynthesis that have been infected with viruses. The analysis of changes in the infected bacteria’s gene activation and metabolism under lab conditions designed to mimic nature hints at an intriguing possibility: The dual threat of viral infection and drifting among hungry predator microbes might lead cyanovirocells to take in more carbon.

Differences in male and female ostriches could explain how they form groups

Photo credit: Julian Melgar

Males and females are affected in different ways by cooperation and competition in social groups – something that could determine which group sizes work best. According to a new study from Lund University in Sweden, this depends to a large extent quite simply on females and males having different interests.

Over a seven-year period, the researchers studied ostriches in differently sized groups in order to understand the pros and cons of living in a group. At the start of each breeding season, experimental groups of ostriches were established by placing different numbers of males and females in enclosures.

The group sizes were similar to those seen in the wild. During part of the breeding season, the ostriches’ natural cooperative incubation behavior was prevented by temporarily removing eggs. Using this approach, the researchers could measure what effect the number of males and females and cooperation over incubation had on the group’s reproductive success, measured in the number of offspring born.

“We decided to study the ostriches under controlled conditions in order to distinguish the effect of individual differences from group attributes on reproductive success and find out how competition and cooperation changed with the size of the group,” says Julian Melgar, a biology researcher at Lund University.

Obesity and biological sex may make individuals more vulnerable to COVID-19

A new West Virginia University study suggests obesity may impair the ability to fight off SARS-CoV-2, the virus that causes COVID-19, in a sex-dependent manner.
Credit: WVU Illustration/Graham Curry

A new animal study from Katherine Lee, a researcher with the West Virginia University School of Medicine, investigates why individuals with obesity may have a particularly difficult time fending off SARS-CoV-2, the virus that causes COVID-19. Specifically, female obese mice experienced worse disease symptoms, showing the importance of both obesity and biological sex in COVID-19 outcomes.

Lee’s findings appear in the journal iScience.

Obesity dramatically increases someone’s risk of being hospitalized, placed on a ventilator or dying due to COVID-19. Considering that about two out of every five Americans are obese, that risk is far from negligible.

“No human is 100% healthy in every respect,” said Lee, a doctoral student in the Department of Microbiology, Immunology and Cell Biology. “There are always going to be little differences in the way our bodies function and those changes can ultimately affect the ways we respond to everything. So, I think as soon as we start incorporating those differences and changes — metabolic diseases and preexisting conditions — into our work, we can learn more about how vaccines and therapeutics might be more or less effective in these people.”

Treatment for back pain: 84 percent increase in success rate

People who sit a lot and do not exercise often develop back pain.
Credits: Markus Bernards for Goethe University Frankfurt

If a therapy for chronic back pain is tailored specifically to a patient’s individual requirements, the chances of success are far greater than with standard forms of treatment. Accompanied by a psychotherapeutic procedure in the shape of cognitive behavioral therapy, the pain can be alleviated even more effectively. This is the result of a meta-analysis by Goethe University Frankfurt, in which the data of over 10,000 patients were combined and analyzed. It can be concluded from the study that multimodal therapies should be promoted on a larger scale in the German healthcare system, in line with the National Disease Management Guidelines.

Lack of exercise, bad posture, overexertion, constant stress at work or at home – back pain is a widespread condition with many causes. For a not insignificant number of sufferers, the symptoms are even chronic, meaning they persist for a long time or recur again and again. Sport and exercise therapies under instruction can bring relief. Common treatment methods include physiotherapy as well as strength and stability exercises. But how can the therapy be as successful as possible? Which approach alleviates pain most effectively? A meta-analysis by Goethe University Frankfurt, published recently in the Journal of Pain, has delivered new insights.

Reliably estimating proportion of vaccinated populations in wildlife

Japanese Wild Boar
Credit: KENPEI, CC BY-SA 3.0/Wikimedia Commons

Researchers develop a ground-breaking model to estimate bait vaccination effectiveness in wild animals based on the proportion of immunized animals in a population and the number of vaccine applications.

Wild animals are host to pathogens that cause a wide variety of infectious diseases, including zoonotic diseases such as rabies, influenza and tuberculosis. The control of these diseases in wild animals is an important issue in the fields of public health, livestock health, and conservation biology. One of the most widely used methods of control is vaccination of wildlife via bait containing oral vaccines (bait vaccination). However, assessing the effectiveness of these vaccines has been difficult.

A team of scientists led by Associate Professor Ryosuke Omori at the International Institute for Zoonoses Control, Hokkaido University, has developed a ground-breaking model to estimate the effectiveness of bait vaccination in wild animals. Their model and findings were published in the journal PLOS Computational Biology.

How evolution overshot the optimum bone structure in hopping rodents

A bipedal jerboa, one of the rodent species included in a study of unpredictability in animal movements.
 Image credit: Talia Moore and Kim Cooper

Bones that are separate in small jerboas are fully fused in large ones, but the bone structures that are best at dissipating the stresses of jumping are only partially fused

Foot bones that are separate in small hopping rodents are fused in their larger cousins, and a team of researchers at the University of Michigan and University of California, San Diego, wanted to know why.

It appears that once evolution set jerboa bones on the path toward fusing together, they overshot the optimum amount of fusing—the structure that best dissipated stresses from jumping and landing—to become fully bonded.

This finding could inform the design of future robotic legs capable of withstanding the higher forces associated with rapid bursts of agile locomotion.

Jerboas are desert rodents that hop erratically on two legs to avoid predators. Across the jerboa family tree, these two legs can look a lot different: there are species that weigh just three grams to those that weigh 400 grams, with heavier species sporting vastly different bones of the feet, or metatarsals. Lighter jerboas are like most other mammals, including humans: their metatarsal foot bones are separate from each other.

NUS study addresses the causes of eye color variation in primates

Some of the images measured and analyzed in the study, picturing the diversity in color and forms.
 Credit: Juan Olvido Perea-García

Scientists discover that this diversity is partly due to lighting differences in their habitats

Have you ever wondered why some people have lighter eyes than others? Differences in iris coloration have traditionally been explained as a result of sexual selection, but a recent study led by researchers from the Department of Biological Sciences at the National University of Singapore (NUS) Faculty of Science revealed that this is partly due to differences in lighting in the habitats of primate species.

For over 20 years, studies focused on explaining variation in primate eye coloration have exclusively focused on eyes as visual signals for inter and intra-specific communication. This idea, however, has received little support from experimental studies in species other than humans. Other suggestions, like eye pigmentation patterns being used in camouflage against predators, have also received limited support.

Even though eyes help us navigate the world thanks to light entering that organ, the idea that eye color diversity may have evolved due to different qualities of light being present in different habitats was never seriously considered.