Scientists chart how exercise affects the body

MIT and Harvard Medical School researchers mapped out many of the cells, genes, and cellular pathways that are modified by exercise or high-fat diet.
Photo Credit: Gabin Vallet

Exercise is well-known to help people lose weight and avoid gaining it. However, identifying the cellular mechanisms that underlie this process has proven difficult because so many cells and tissues are involved.

In a new study in mice that expands researchers’ understanding of how exercise and diet affect the body, MIT and Harvard Medical School researchers have mapped out many of the cells, genes, and cellular pathways that are modified by exercise or high-fat diet. The findings could offer potential targets for drugs that could help to enhance or mimic the benefits of exercise, the researchers say.

“It is extremely important to understand the molecular mechanisms that are drivers of the beneficial effects of exercise and the detrimental effects of a high-fat diet, so that we can understand how we can intervene, and develop drugs that mimic the impact of exercise across multiple tissues,” says Manolis Kellis, a professor of computer science in MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and a member of the Broad Institute of MIT and Harvard.

The researchers studied mice with high-fat or normal diets, who were either sedentary or given the opportunity to exercise whenever they wanted. Using single-cell RNA sequencing, the researchers cataloged the responses of 53 types of cells found in skeletal muscle and two types of fatty tissue.

Dinosaur-killing asteroid triggered global tsunami that scoured seafloor thousands of miles from impact site

The miles-wide asteroid that struck Earth 66 million years ago wiped out nearly all the dinosaurs and roughly three-quarters of the planet’s plant and animal species.

It also triggered a monstrous tsunami with mile-high waves that scoured the ocean floor thousands of miles from the impact site on Mexico’s Yucatan Peninsula, according to a new University of Michigan-led study.

The study, published online Oct. 4 in the journal AGU Advances, presents the first global simulation of the Chicxulub impact tsunami to be published in a peer-reviewed scientific journal. In addition, U-M researchers reviewed the geological record at more than 100 sites worldwide and found evidence that supports their models’ predictions about the tsunami’s path and power.

“This tsunami was strong enough to disturb and erode sediments in ocean basins halfway around the globe, leaving either a gap in the sedimentary records or a jumble of older sediments,” said lead author Molly Range, who conducted the modeling study for a master’s thesis under U-M physical oceanographer and study co-author Brian Arbic and U-M paleoceanographer and study co-author Ted Moore.

Artificial Enzyme Splits Water

Enzyme-like water preorganization in front of a Ruthenium water oxidation catalyst.
Image credit: Team Würthner

Progress has been made on the path to sunlight-driven production of hydrogen. Chemists from Würzburg present a new enzyme-like molecular catalyst for water oxidation.

Mankind is facing a central challenge: it must manage the transition to a sustainable and carbon dioxide-neutral energy economy.

Hydrogen is considered a promising alternative to fossil fuels. It can be produced from water using electricity. If the electricity comes from renewable sources, it is called green hydrogen. But it would be even more sustainable if hydrogen could be produced directly with the energy of sunlight.

In nature, light-driven water splitting takes place during photosynthesis in plants. Plants use a complex molecular apparatus for this, the so-called photosystem II. Mimicking its active center is a promising strategy for realizing the sustainable production of hydrogen. A team led by Professor Frank Würthner at the Institute of Organic Chemistry and the Center for Nanosystems Chemistry at Julius-Maximilians-Universität Würzburg (JMU) is working on this.

Solar Harvesting System has Potential to Generate Solar Power 24/7

Bo Zhao, Kalsi Assistant Professor of mechanical engineering, and his doctoral student, Sina Jafari Ghalekohneh, have created new architecture that improves the efficiency of solar energy harvesting to the thermodynamic limit.
Source: University of Houston

The great inventor Thomas Edison once said, “So long as the sun shines, man will be able to develop power in abundance.”

He wasn’t the first great mind to marvel at the notion of harnessing the power of the sun; for centuries inventors have been pondering and perfecting the way to harvest solar energy.

They’ve done an amazing job with photovoltaic cells which convert sunlight directly into energy. And still, with all the research, history and science behind it, there are limits to how much solar power can be harvested and used – as its generation is restricted only to the daytime.

A University of Houston professor is continuing the historic quest, reporting on a new type of solar energy harvesting system that breaks the efficiency record of all existing technologies. And no less important, it clears the way to use solar power 24/7.

"With our architecture, the solar energy harvesting efficiency can be improved to the thermodynamic limit,” reports Bo Zhao, Kalsi Assistant Professor of mechanical engineering and his doctoral student Sina Jafari Ghalekohneh in the journal Physical Review Applied. The thermodynamic limit is the absolute maximum theoretically possible conversion efficiency of sunlight into electricity.

Finding more efficient ways to harness solar energy is critical to transitioning to a carbon-free electric grid. According to a recent study by the U.S. Department of Energy Solar Energy Technologies Office and the National Renewable Energy Laboratory, solar could account for as much as 40% of the nation’s electricity supply by 2035 and 45% by 2050, pending aggressive cost reductions, supportive policies and large-scale electrification.

Mouse-human comparison shows unimagined functions of the Thalamus

With mathematical models, Bochum and US researchers have simulated processes in the brain of mice and humans.
Credit: RUB, Marquard

Researchers have reproduced the brain functions of the mouse and human in the computer. Artificial intelligence could learn from this.

For a long time, the thalamus was considered a brain region that is primarily responsible for processing sensory stimuli. Current studies have increased the evidence that it is a central switch in cognitive processes. Researchers of neuroscience around Prof. Dr. Burkhard Pleger in Collaborative Research Center 874 of the Ruhr University Bochum and a team from the Massachusetts Institute of Technology (MIT, USA) observed learning processes in the brains of mice and humans and reproduced them in mathematical models. They were able to show that the region of the mediodoral nucleus in the thalamus has a decisive share in cognitive flexibility. They report in the journal PLOS Computational Biology.

Restoring abandoned agricultural land in the Murray-Darling Basin

Abandoned agricultural land in the Murray Darling Basin.
Photo credit: Peta Zivec

A Griffith study has found the number of diverse seeds stored in abandoned land in the Murray-Darling Basin and essential paddock trees, make the region highly resilient to agriculture.

Published in Restoration Ecology, the study investigated the ability of semi-arid landscapes in the northern MDB to store seeds in soil seed banks, animal scat and in leaf litter and assessed the species richness, abundance and composition of these seed banks.

“Restoring abandoned agricultural lands is vital for the Murray-Darling Basin to revive the key ecological functions and services the river and its surrounding regions once provided,” said Dr Peta Zivec, a research fellow at the Australian Rivers Institute

“With large-scale regeneration projects being extremely costly and labor intensive, natural regeneration, where the vegetation regrows via the seeds already stored within the landscape, can be a cost-effective alternative approach to restoring large agricultural areas.

Technology for Conditioning Radioactive Waste Developed in Ural Region

The containers have a metal insert with a sorbent.
Photo credit: EKSORB press-service

Ural specialists have developed and tested a technology for conditioning (conversion from liquid to solid state) of liquid radioactive waste. The traditional scheme involves mixing sorbent enriched with radioactive isotopes of cesium-134 and 137 and cobalt-60 during the purification of liquid radioactive waste with cement mortar and placing it in special concrete protective containers. However, this requires a large number of containers, which increases the cost of processing and the volume of storage facilities to place the containers. Composite inorganic sorbents have been gaining popularity lately because they concentrate radionuclides very well from a large volume of liquid with a small volume of the sorbents themselves.

Scientists have developed a technology that makes it possible to condition liquid radioactive waste and then safely store the resulting solid waste. The technology is being developed by the EKSORB Scientific Production Enterprise (Ekaterinburg) with the support of the Foundation for Assistance to Innovations and in cooperation with the Ural Federal University.

The specialists tested the technology on a pilot plant. It was used to clean more than three cubic meters of liquid radioactive waste of BN-350 Reactor. As a result, the activity of cesium-137 decreased from 78 million Bq/L to 20 Bq/L, cobalt-60 - from 10 thousand Bq/L to less than 400 Bq/L. The clean concrete product was obtained from the cleaned solutions. After cleaning, the resulting solid waste can be stored safely, the developers assure.

The cell sentinel that neutralizes hepatitis B

Confocal microscopy images showing in the cell nucleus (blue), the recruitment of Smc5/6 (green) by SLF2 (red) into PML bodies.
Credit: UNIGE - Laboratory of Professor Michel Strubin - Regulation of hepatitis B virus gene expression - Department of Microbiology and Molecular Medicine.

The hepatitis B virus (HBV) is responsible for one of the most serious and common infectious diseases. Transmitted through biological fluids, it attacks the liver cells. The chronic form of the disease can lead to serious complications, including cirrhosis and liver cancer. There is no effective treatment for the chronic form of the disease, which can only be prevented by vaccination. After identifying a key protein complex that is active when our body is infected by the virus, a team from the University of Geneva (UNIGE) has deciphered the precise functioning of this protective mechanism, opening the way to new therapeutic targets. These results can be read in the journal Nature Structural and Molecular Biology.

Hepatitis B is the most common form of hepatitis. It is a viral disease caused by the hepatitis B virus. It is mainly blood or sexually transmitted. It is up to 100 times more contagious than HIV. By infecting the liver cells, this virus causes a transitory inflammation of this organ that can also evolve towards a chronic infection. This can then lead to serious pathologies, such as cirrhosis or liver cancer. It is estimated that nearly one million people die each year from this disease worldwide. There is no definitive treatment for chronic hepatitis B. The only way to prevent it is to be vaccinated before the disease appears.

In 2016, a UNIGE team led by Michel Strubin, an associate professor in the Department of Microbiology and Molecular Medicine and in the Geneva Centre for Inflammation Research at the UNIGE Faculty of Medicine, revealed a mechanism that is crucial for understanding this disease: when our immune system defends itself against it, a complex - i.e. an interdependent set - of six proteins called SMC5/6, present in our cells, detects the viral DNA and blocks it. The virus then strikes back and produces a specific protein, the X protein. This protein enters the cell and degrades SMC5/6, which is no longer able to play its sentinel role.

Coronavirus formation is successfully modeled

Roya Zandi (left) and Siyu Li. (UCR/Zandi lab)
Source: University of California, Riverside

A physicist at the University of California, Riverside, and her former graduate student have successfully modeled the formation of SARS-CoV-2, the virus that spreads COVID-19, for the first time.

In a paper published in Viruses, a journal, Roya Zandi, a professor of physics and astronomy at UCR, and Siyu Li, a postdoctoral researcher at Songshan Lake Materials Laboratory in China, offer an overall understanding of the assembly and formation of SARS-CoV-2 from its constituent components.

“Understanding viral assembly has always been a key step leading to therapeutic strategies,” Zandi said. “Numerous experiments and simulations of viruses such as HIV and hepatitis B virus have had a remarkable impact on elucidating their assembly and providing means to combat them. Even the simplest questions regarding the formation of SARS-CoV-2 remain unanswered.”

Zandi explained that a critical step in the life cycle of any virus is the packaging of its genome into new virions or virus particles. This is an especially challenging task for coronaviruses, like SARS-CoV-2, with their very large RNA genomes. Indeed, coronaviruses have the largest genome known for a virus that uses RNA as its genetic material.

Small eddies play a big role in feeding ocean microbes

This video still of the North Pacific Ocean shows phosphate nutrient concentrations at 500 meters below the ocean surface. The swirls represent small eddies transporting phosphate from the nutrient-rich equator (lighter colors), northward toward the nutrient-depleted subtropics (darker colors).
Credit: Courtesy of the researchers

Subtropical gyres are enormous rotating ocean currents that generate sustained circulations in the Earth’s subtropical regions just to the north and south of the equator. These gyres are slow-moving whirlpools that circulate within massive basins around the world, gathering up nutrients, organisms, and sometimes trash, as the currents rotate from coast to coast.

For years, oceanographers have puzzled over conflicting observations within subtropical gyres. At the surface, these massive currents appear to host healthy populations of phytoplankton — microbes that feed the rest of the ocean food chain and are responsible for sucking up a significant portion of the atmosphere’s carbon dioxide.

But judging from what scientists know about the dynamics of gyres, they estimated the currents themselves wouldn’t be able to maintain enough nutrients to sustain the phytoplankton they were seeing. How, then, were the microbes able to thrive?

Now, MIT researchers have found that phytoplankton may receive deliveries of nutrients from outside the gyres, and that the delivery vehicle is in the form of eddies — much smaller currents that swirl at the edges of a gyre. These eddies pull nutrients in from high-nutrient equatorial regions and push them into the center of a gyre, where the nutrients are then taken up by other currents and pumped to the surface to feed phytoplankton.