Gut Microbiomes Help Bears with Very Different Diets Reach the Same Size

Photo credit: National Park Service.

A recent study of the gut microbiome of Alaskan brown bears (Ursus arctos) shows that the microbial life in bears’ guts allows them to achieve comparable size and fat stores while eating widely different diets. The work sheds light on the role of the gut microbiome in supporting health in wild omnivores.

“We think of bears as having simple digestive tracts, so it’s easy to slip into thinking that they therefore have simple gut microbiomes,” says Erin McKenney, co-author of the study and an assistant professor of applied ecology at North Carolina State University. “But this study shows there can be tremendous diversity in the gut microbiomes between individual bears, and that this variation can be very important to the physical condition of these animals.”

“For example, the amount of fat that bears are able to store is absolutely critical to the health of wild populations,” says Grant Hilderbrand, co-author of the study and associate regional director for resources for the National Park Service in Alaska. “If female bears are able to reach levels where 19-20% of their body mass in the autumn is fat, they’ll reproduce. And knowing that they can take different dietary paths to reach those fat levels is a valuable insight.”

For this study, researchers collected fecal samples from 51 adult brown bears in three national parks: Katmai National Park and Preserve, Lake Clark National Park and Preserve, and Gates of the Arctic National Park and Preserve.

How global warming affects astronomical observations

The VLT's Laser Guide Star: A laser beam launched from VLT´s 8.2-metre Yepun telescope crosses the majestic southern sky and creates an artificial star at 90 km altitude in the high Earth´s mesosphere. The Laser Guide Star (LGS) is part of the VLT´s Adaptive Optics system and it is used as reference to correct images from the blurring effect of the atmosphere.
Credit: ESO / G. Hüdepohl atacamaphoto.com

Astronomical observations from ground-based telescopes are sensitive to local atmospheric conditions. Anthropogenic climate change will negatively affect some of these conditions at observation sites around the globe, as a team of researchers led by the University of Bern and the National Centre of Competence in Research (NCCR) PlanetS reports.

The quality of ground-based astronomical observations delicately depends on the clarity of the atmosphere above the location from which they are made. Sites for telescopes are therefore very carefully selected. They are often high above sea level, so that less atmosphere stands between them and their targets. Many telescopes are also built in deserts, as clouds and even water vapor hinder a clear view of the night sky.

A team of researchers led by the University of Bern and the National Centre of Competence in Research (NCCR) PlanetS shows in a study, published in the journal Astronomy & Astrophysics and presented at the Europlanet Science Congress 2022 in Granada, how one of the major challenges of our time – anthropogenic climate change – now even affects our view of the cosmos.

Wildfire smoke is unraveling decades of air quality gains

Over the last decade, PM2.5 from wildfire smoke has increased in much of the U.S., particularly in Western states, but some areas in the South and East have seen modest declines. This map shows the decadal change in smoke PM2.5, meaning the difference in daily average smoke PM2.5 during 2006−2010 compared to 2016−2020.
Image credit: Childs et al. 2022, Environmental Science & Technology

Stanford researchers have developed an AI model for predicting dangerous particle pollution to help track the American West’s rapidly worsening wildfire smoke. The detailed results show millions of Americans are routinely exposed to pollution at levels rarely seen just a decade ago.

Wildfire smoke now exposes millions of Americans each year to dangerous levels of fine particulate matter, lofting enough soot across parts of the West in recent years to erase much of the air quality gains made over the last two decades.

Those are among the findings of a new Stanford University study published Sept. 22 in Environmental Science & Technology that focuses on a type of particle pollution known as PM2.5, which can lodge deep in our lungs and even get into our bloodstream.

Using statistical modeling and artificial intelligence techniques, the researchers estimated concentrations of PM2.5 specifically from wildfire smoke in sharp enough detail to reveal variations within individual counties and individual smoke events from coast to coast from 2006 to 2020.

“We found that people are being exposed to more days with wildfire smoke and more extreme days with high levels of fine particulate matter from smoke,” said lead study author Marissa Childs, who worked on the research as a PhD student in Stanford’s Emmett Interdisciplinary Program in Environment and Resources (E-IPER). Unlike other major pollutant sources, wildfire smoke is considered an “exceptional event” under the Clean Air Act, she explained, “which means an increasing portion of the particulate matter that people are exposed to is unregulated.”

Researchers develop a cobalt-free cathode for lithium-ion batteries

Working with researchers at four U.S. national laboratories, Huolin Xin, UCI professor of physics & astronomy, has found a way to fabricate lithium-ion batteries without using cobalt, a rare, costly mineral extracted under inhumane conditions in Central Africa.
Credit: Steve Zylius / UCI

Researchers at the University of California, Irvine and four national laboratories have devised a way to make lithium-ion battery cathodes without using cobalt, a mineral plagued by price volatility and geopolitical complications.

In a paper published today in Nature, the scientists describe how they overcame thermal and chemical-mechanical instabilities of cathodes composed substantially of nickel – a common substitute for cobalt – by mixing in several other metallic elements.

“Through a technique we refer to as ‘high-entropy doping,’ we were able to successfully fabricate a cobalt-free layered cathode with extremely high heat tolerance and stability over repeated charge and discharge cycles,” said corresponding author Huolin Xin, UCI professor of physics & astronomy. “This achievement resolves long-standing safety and stability concerns around high-nickel battery materials, paving the way for broad-based commercial applications.”

Cobalt is one of the most significant supply chain risks threatening widespread adoption of electric cars, trucks and other electronic devices requiring batteries, according to the paper’s authors. The mineral, which is chemically suited for the purpose of stabilizing lithium-ion battery cathodes, is mined almost exclusively in the Democratic Republic of Congo under abusive and inhumane conditions.

Astronomers Unveil New – and Puzzling – Features of Mysterious Fast Radio Bursts

Artist's conception of Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China.
Credit: Jingchuan Yu

Fast radio bursts (FRBs) are millisecond-long cosmic explosions that each produce the energy equivalent to the sun’s annual output. More than 15 years after the deep-space pulses of electromagnetic radio waves were first discovered, their perplexing nature continues to surprise scientists – and newly published research only deepens the mystery surrounding them.

In the Sept. 21 issue of the journal Nature, unexpected new observations from a series of cosmic radio bursts by an international team of scientists – including UNLV astrophysicist Bing Zhang – challenge the prevailing understanding of the physical nature and central engine of FRBs.

The cosmic FRB observations were made in late spring 2021 using the massive Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China. The team, led by Heng Xu, Kejia Lee, Subo Dong from Peking University, and Weiwei Zhu from the National Astronomical Observatories of China, along with Zhang, detected 1,863 bursts in 82 hours over 54 days from an active fast radio burst source called FRB 20201124A.

“This is the largest sample of FRB data with polarization information from one single source”, said Lee.

Smashing Heavy Nuclei Reveals Proton Size

A model assuming smaller protons & neutrons & a “lumpier” arrangement of these building blocks (left) fits experimental data on the initial energy density in heavy ion collisions better than a model w/ larger protons, neutrons & smoother structure (right)
Image credit: Brookhaven National Laboratory

The nuclei of atoms are made up of protons and neutrons, collectively referred to as nucleons. Nucleons in turn consist of quarks and gluons. Understanding how those inner building blocks are distributed within nuclei can reveal how large protons and neutrons appear when probed at high energy. This work used comparisons between model calculations and new precision data from collisions of heavy ions (containing many protons and neutrons) to access the distribution of gluons and predict the size of the proton.

Identifying and precisely measuring factors that are sensitive to nucleon size will help physicists more accurately describe the quark-gluon plasma (QGP). This is a hot, dense form of nuclear matter created when individual protons and neutrons “melt” in heavy ion collisions, mimicking the conditions of the early universe. This knowledge can eliminate significant uncertainties about the initial state of the produced QGP. Knowing more about the initial state of QGP provides input for the model calculations that scientists use to infer the viscosity and other properties of the QGP. The results also add to measurements of proton size based on the distribution of quarks inside the proton.

Shutting down backup genes leads to cancer remission in mice

Abhinav Achreja, PhD, Research Fellow at the University of Michigan Biomedical Engineering and Deepak Nagrath, Ph.D. Associate Professor of Biomedical Engineering works on ovarian cancer cell research in the bio-engineering lab at the North Campus Research Center (NCRC).
Image credit: Marcin Szczepanski, Michigan Engineering

The way that tumor cells enable their uncontrolled growth is also a weakness that can be harnessed to treat cancer, researchers at the University of Michigan and Indiana University have shown.

Their machine-learning algorithm can identify backup genes that only tumor cells are using so that drugs can target cancer precisely.

“Most cancer drugs affect normal tissues and cells. However, our strategy allows specific targeting of cancer cells.”

Deepak Nagrath

The team demonstrated this new precision medicine approach for treating ovarian cancer in mice. Moreover, the cellular behavior that exposes these vulnerabilities is common across most forms of cancer, meaning the algorithms could provide better treatment plans for a host of malignancies.

“This could revolutionize the precision medicine field because the drug targeting will only affect and kill cancer cells and spare the normal cells,” said Deepak Nagrath, a U-M associate professor of biomedical engineering and senior author of the study in Nature Metabolism. “Most cancer drugs affect normal tissues and cells. However, our strategy allows specific targeting of cancer cells.”

Ocean scientists measure sediment plume stirred up by deep-sea-mining vehicle

The Launch and Recovery System deploying the Patania II pre-prototype collector vehicle from the surface operations vessel MV Normand Energy.
Credit: Global Sea Mineral Resources

What will be the impact to the ocean if humans are to mine the deep sea? It’s a question that’s gaining urgency as interest in marine minerals has grown.

The ocean’s deep-sea bed is scattered with ancient, potato-sized rocks called “polymetallic nodules” that contain nickel and cobalt — minerals that are in high demand for the manufacturing of batteries, such as for powering electric vehicles and storing renewable energy, and in response to factors such as increasing urbanization. The deep ocean contains vast quantities of mineral-laden nodules, but the impact of mining the ocean floor is both unknown and highly contested.

Now MIT ocean scientists have shed some light on the topic, with a new study on the cloud of sediment that a collector vehicle would stir up as it picks up nodules from the seafloor.

The study, appearing today in Science Advances, reports the results of a 2021 research cruise to a region of the Pacific Ocean known as the Clarion Clipperton Zone (CCZ), where polymetallic nodules abound. There, researchers equipped a pre-prototype collector vehicle with instruments to monitor sediment plume disturbances as the vehicle maneuvered across the seafloor, 4,500 meters below the ocean’s surface. Through a sequence of carefully conceived maneuvers. the MIT scientists used the vehicle to monitor its own sediment cloud and measure its properties.

Their measurements showed that the vehicle created a dense plume of sediment in its wake, which spread under its own weight, in a phenomenon known in fluid dynamics as a “turbidity current.” As it gradually dispersed, the plume remained relatively low, staying within 2 meters of the seafloor, as opposed to immediately lofting higher into the water column as had been postulated.

A new understanding of the neurobiology of impulsivity News

Photo Credit: Vitolda Klein

While not all impulsive behavior speaks of mental illness, a wide range of mental health disorders which often emerge in adolescence, including depression and substance abuse, have been linked to impulsivity. So, finding a way to identify and treat those who may be particularly vulnerable to impulsivity early in life is especially important.

A group of researchers, led by scholars at McGill University, have developed a genetically based score which could help identify, with a high degree of accuracy (greater than that of any impulsivity scores currently in use), the young children who are most at risk of impulsive behavior.

Their findings are especially compelling because the score they have developed was able to detect those at a higher risk of impulsivity within three ethnically diverse community samples of children, from a cohort of close to 6,000 children.

This discovery of a novel score for impulsivity in early life can inform prevention strategies and programs for children and adolescents who are at risk for psychiatric disorders. In addition, by describing the function of the gene networks comprising the score, the study can stimulate the development of new therapies in the future.

“COVID Time” is a real thing, and it’s not good

Credit: xaviandrew

Have you ever noticed that time seems to slow down sometimes? Like when you are waiting in line at a bank or grocery checkout, and it just seems to take forever?

During the peak of the pandemic, and mid-lockdown, many people reported they felt their days dragged on, inducing fatigue and making some tasks almost unbearable during “COVID time.”

An interdisciplinary team of researchers studied this effect of the COVID-19 pandemic, called Blursday, to understand how our perception of time is malleable and influenced by many factors. Blursday was the altered sense of time and difficulty in determining the day of the week during the lockdown.

Dr. Fuat Balci, a UM biologist and part of the research team, notes: “A new lingo emerged during the COVID-19 pandemic to capture the altered psychological state under the extraordinary conditions imposed by the pandemic such as the lockdown and social isolation, including doomscrolling and Blursday.”

The researchers had volunteers answer a questionnaire and perform 15 behavioral tasks, such as estimating how long they had been logged on to the study’s website. They were also asked to guess if a stated time interval was shorter or longer than they experienced to test how the pandemic affected temporal awareness.