Scientists Create Mathematical Model for Nanoparticle and Virus Dynamics in Cells

Dmitry Aleksandrov and Sergey Fedotov (left to right) determined the behavior of viruses in cells.
 Photo credit: Ilya Safarov

Physicists and mathematicians at the Ural Federal University and the University of Manchester have for the first time created a complex mathematical model that calculates the distribution of nanoparticles (particularly viruses) in living cells. Using the mathematical model, scientists have figured out how nanoparticles cluster (merge into a single particle) inside cells, namely in cellular endosomes, which are responsible for sorting and transporting proteins and lipids.

These calculations will be useful for medical purposes because, on the one hand, they show how viruses behave when they enter cells and tend to replicate. On the other hand, the model allows the exact amount of medication needed for therapy to be as effective as possible and with minimal side effects. The scientists published the model description and calculation results in Crystals, Cancer Nanotechnology and Mathematics.

"The processes in cells are extremely complex, but in simple terms, viruses use different variants to reproduce. Some deliver genetic material directly into the cytoplasm. Others use the endocytosis pathway: they deliver the viral genome by releasing it from the endosomes. If viruses stay in the endosomes, the acidity increases there, and they die in the lysosomes. So, our model allowed us to find out, first of all, when and which viruses "escape" from endosomes in order to survive. For example, some influenza viruses are low-pH-dependent viruses; they fuse with the endosome membrane and release their genome into the cytoplasm. Secondly, we found out that it is easier for viruses to survive in endosomes during clustering, when two particles merge and tend to form a single particle," says Dmitry Aleksandrov, Head of the Multi-Scale Mathematical Modeling Laboratory at UrFU.

Circalunar clocks: using the right light

Moonlight plays an important role in synchronizing the reproductive cycles of marine life.
Credit Carolina Castro

How animals are able to interpret natural light sources to adjust their physiology and behavior is poorly understood. The labs of Kristin Tessmar-Raible (Max Perutz Labs Vienna, Alfred Wegener Institut, University of Oldenburg) and Eva Wolf (Johannes Gutenberg University and Institute of Molecular Biology Mainz) have now revealed that a molecule called L-cryptochrome (L-Cry) has the biochemical properties to discriminate between different moon phases, as well as between sun- and moonlight. Their findings, published in Nature Communications, show that L-Cry can interpret moonlight to entrain the monthly (circalunar) clock of a marine worm to control sexual maturation and reproduction.

Many marine organisms, including brown algae, fish, corals, turtles and bristle worms, synchronize their behavior and reproduction with the lunar cycle. For some species, such as the bristle worm Platynereiis dumerilii, lab experiments have shown that moonlight exerts its timing function by entraining an inner monthly calendar, also called circalunar clock. Under these laboratory conditions, mimicking the duration of the full moon is sufficient to entrain these circalunar clocks. However, in natural habitats light conditions can vary considerably. Even the regular interplay of sun- and moon creates highly complex patterns. Organisms using lunar light for their timing thus need to discriminate between specific moon phases and between sun and moonlight. This ability is not well understood. "We have now revealed that one light receptive molecule, called L-Cry, is able to discriminate between different light valences," says co-first author of the study, Birgit Poehn. This Cryptochrome thereby serves as a light sensor that is able to measure light intensity and duration, thus helping the animals to choose the "right" light to adequately adjust their monthly timing system.

A breakthrough discovery in carbon capture conversion for ethylene production

 Abstract illustration of atoms passing through water and an electrified membrane under a shining sun.
Credit: Meenesh Singh

A team of researchers led by Meenesh Singh at University of Illinois Chicago has discovered a way to convert 100% of carbon dioxide captured from industrial exhaust into ethylene, a key building block for plastic products.

Their findings are published in Cell Reports Physical Science.

While researchers have been exploring the possibility of converting carbon dioxide to ethylene for more than a decade, the UIC team’s approach is the first to achieve nearly 100% utilization of carbon dioxide to produce hydrocarbons. Their system uses electrolysis to transform captured carbon dioxide gas into high purity ethylene, with other carbon-based fuels and oxygen as byproducts.

The process can convert up to 6 metric tons of carbon dioxide into 1 metric ton of ethylene, recycling almost all carbon dioxide captured. Because the system runs on electricity, the use of renewable energy can make the process carbon negative.

According to Singh, his team’s approach surpasses the net-zero carbon goal of other carbon capture and conversion technologies by actually reducing the total carbon dioxide output from industry. “It’s a net negative,” he said. “For every 1 ton of ethylene produced, you’re taking 6 tons of CO2 from point sources that otherwise would be released to the atmosphere.”

Culprit behind mass extinction identified, motive remains unknown

Credit: NASA's Goddard Space Flight Center Conceptual Image Lab

About 183 million years ago tremendous volcanic eruptions occurred and lava deposits rivalling the size of continents covered Earth’s surface, causing mass extinctions and changing the ocean’s chemistry and global climates. What triggered this has been a mystery for the past 183 million years, but a new paper published in Science Advances offers a compelling explanation.

One of the paper’s co-authors, Ricardo L. Silva, an Assistant Professor in Paleoenvironmental Sedimentology in the University of Manitoba’s Department of Earth Sciences, explains that what likely enabled this catastrophic series of events was a slowing of the tectonic plates. In short, the team found the long-sought mechanism that links Earth’s interior and surficial processes and came up with an explanation for one of Earth’s major past global climate and mass extinction events.

“Imagine you’re using a pressure washer on the side of your house, but then you stop moving the spout and spray water in one place,” Silva says. “Eventually, you’ll bore a hole through your house. Now make a magma plume from deep inside the Earth the pressure washer and tectonic plates your house. That’s what happened. And when the magma bore through the plates, vast amounts of carbon dioxide were released, and when the magma heated the surrounding rocks, even more carbon was released.”

How a small, unassuming fish helps reveal gene adaptations

Jesse Weber collects stickleback with a minnow trap in the Kenai Peninsula of Alaska
Credit: Matt Chotlos

At first blush, sticklebacks might seem a bit pedestrian. The finger-length, unassuming fish with a few small dorsal spines are a ubiquitous presence in oceans and coastal watersheds around the northern hemisphere. But these small creatures are also an excellent subject for investigating the complex dance of evolutionary adaptations.

A new study published in Science sheds light on the genetic basis by which stickleback populations inhabiting ecosystems near each other developed a strong immune response to tapeworm infections, and how some populations later came to tolerate the parasites.

Evolutionary biologist Jesse Weber, a professor of integrative biology at the University of Wisconsin–Madison, is one of the study’s lead authors. Sticklebacks have long been a source of fascination not only for Weber, but for biologists all over the world — so much so that the fish are among the most closely studied species.

“We arguably know more about stickleback ecology and evolution than any other vertebrate,” says Weber.

This is in part because of sticklebacks’ rich abundance in places like Western Europe, where the fish have long been involved in biological study, Weber says. But the reasons for the species’ star status go well beyond happenstance.

New Technology Can Efficiently Extract Non-Ferrous Metal from Batteries

The decomposition time of discarded nutrients can exceed 100 years.
Photo Credit: Unsplash.com / John Cameron

Scientists at Ural Federal University have developed a technology for extracting non-ferrous metals from spent zinc-manganese batteries. The zinc and manganese extracted in this way can be used in metallurgy and sent to production as raw materials. The technology is a closed cycle and can be easily implemented at existing metallurgical plants. A description of the technology and experimental results are presented in the Russian Journal of Non-Ferrous Metals.

Zinc-manganese batteries, specifically salt and alkaline batteries, are ubiquitous in everyday life, such as in remote controls, wireless computer mice, keyboards, clocks, and other devices. Recycling of such batteries is topical for obtaining zinc and especially manganese, since the latter is not produced in metallic form in Russia. The recovered zinc can be used as a reducing agent for gold in the process of its deep cleaning from impurities. Manganese can be used in steel production as an alloying element or a deoxidizer, in other words for removing dissolved oxygen from the metal.

"In Russia about 1 billion zinc-manganese batteries are accumulated as waste, and no more than 3% of them are recycled. The accumulation of batteries in landfills is dangerous because they can spontaneously ignite. Burning batteries release dioxins into the atmosphere as toxic substances that have mutagenic, immunosuppressant and carcinogenic effects. Thus, our team solves two problems: caring for the environment and people's health, as well as the possibility of useful use of metals," says Elvira Kolmachikhina, Associate Professor of the Department of Non-Ferrous Metallurgy at Ural Federal University.

New AI system predicts how to prevent wildfires

Satellite image of Borneo in 2006 covered by smoke from fires (marked by red dots).
Image Credit: Jeff Schmaltz, MODIS Rapid Response Team / NASA

A machine learning model can evaluate the effectiveness of different management strategies

Wildfires are a growing threat in a world shaped by climate change. Now, researchers at Aalto University have developed a neural network model that can accurately predict the occurrence of fires in peatlands. They used the new model to assess the effect of different strategies for managing fire risk and identified a suite of interventions that would reduce fire incidence by 50-76%.

The study focused on the Central Kalimantan province of Borneo in Indonesia, which has the highest density of peatland fires in Southeast Asia. Drainage to support agriculture or residential expansion has made peatlands increasingly vulnerable to recurring fires. In addition to threatening lives and livelihoods, peatland fires release significant amounts of carbon dioxide. However, prevention strategies have faced difficulties because of the lack of clear, quantified links between proposed interventions and fire risk.

The new model uses measurements taken before each fire season in 2002-2019 to predict the distribution of peatland fires. While the findings can be broadly applied to peatlands elsewhere, a new analysis would have to be done for other contexts. ‘Our methodology could be used for other contexts, but this specific model would have to be re-trained on the new data,’ says Alexander Horton, the postdoctoral researcher who carried out study.

Could more of Earth’s surface host life?

There are varying degrees of orbital eccentricity around a central star.
Credit: NASA/JPL-Caltech

Of all known planets, Earth is as friendly to life as any planet could possibly be — or is it? If Jupiter’s orbit changes, a new study shows Earth could be more hospitable than it is today.

When a planet has a perfectly circular orbit around its star, the distance between the star and the planet never changes. Most planets, however, have "eccentric" orbits around their stars, meaning the orbit is oval-shaped. When the planet gets closer to its star, it receives more heat, affecting the climate.

Using detailed models based on data from the solar system as it is known today, UC Riverside researchers created an alternative solar system. In this theoretical system, they found that if gigantic Jupiter’s orbit were to become more eccentric, it would in turn induce big changes in the shape of Earth’s orbit.

“If Jupiter’s position remained the same, but the shape of its orbit changed, it could actually increase this planet’s habitability,” said Pam Vervoort, UCR Earth and planetary scientist and lead study author.

Between zero and 100 degrees Celsius, the Earth’s surface is habitable for multiple known life forms. If Jupiter pushed Earth’s orbit to become more eccentric, parts of the Earth would sometimes get closer to the sun. Parts of the Earth’s surface that are now sub-freezing would get warmer, increasing temperatures in the habitable range.

Smart birds think smart and economical

Birds need significantly less energy for their brains than mammals.
Credit: RUB, Marquard

Bird brain cells only need about a third of the energy mammals have to use to supply their brains. "This partly explains how birds manage to be so smart, even though their brains are so much smaller than that of mammals," says Prof. Dr. Onur Güntürkun, head of the biopsychology unit at the Ruhr University Bochum. Together with colleagues from Cologne, Jülich and Düsseldorf, his research team examined the energy consumption of the brains of pigeons using imaging methods. The researchers report in the Current Biology journal dated 8. September 2022.

Why it can take in a crow with a chimpanzee

Our brain only makes up about two percent of our body weight, but consumes about 20 to 25 percent of body energy. "The brain is by far the most energetically expensive organ in our body, and we could only afford it in the course of evolution by successfully learning to supply a lot of energy," explains Güntürkun. The brains of birds are much smaller in comparison. Nevertheless, birds are just as smart as many mammals: crows and parrots, for example, whose brains only weigh about 10 to 20 grams, can cognitively absorb a chimpanzee whose brain weighs 400 grams.

How can that be? A study in 2016 brought light into the dark: It showed that birds per volume of brain mass have two to three times as many nerve cells as mammals. So, your brains are packed much denser. In addition, their cranial nerve cells are smaller. “But the question still arises: How can such a small animal afford so many nerve cells??“Says Onur Güntürkun.

Study unearths ancient reef structure high and dry on the Nullarbor Plain

A satellite image of the ring-shaped structure on the Nullarbor Plain.
Source: Curtin University

Curtin researchers and international collaborators using advanced satellite imagery have discovered an ancient reef-like landform ‘hidden’ in plain view on the Nullarbor Plain, which has been preserved for millions of years since it first formed when the Plain was underwater.

Research author Dr Milo Barham, from the Timescales of Mineral Systems Group within Curtin’s School of Earth and Planetary Sciences said the finding further challenged the understanding that the Nullarbor Plain, which emerged from the ocean about 14 million years ago, was essentially flat and featureless.

“Unlike many parts of the world, large areas of the Nullarbor Plain have remained largely unchanged by weathering and erosion processes over millions of years, making it a unique geological canvas recording ancient history in remarkable ways,” Dr Barham said.

“Through high-resolution satellite imagery and fieldwork, we have identified the clear remnant of an original sea-bed structure preserved for millions of years, which is the first of this kind of landform discovered on the Nullarbor Plain.