. Scientific Frontline

Monday, September 12, 2022

A thousand days of CHEOPS

Artist's impression of CHEOPS
Credit: ESA / ATG medialab

After a thousand days in orbit, the CHEOPS space telescope shows almost no signs of wear. Under these conditions, it could continue to reveal details of some of the most fascinating exoplanets for quite some time. CHEOPS is a joint mission by the European Space Agency (ESA) and Switzerland, under the aegis of the University of Bern in collaboration with the University of Geneva.

Since its launch from Europe's Spaceport in French Guiana, on December 18th, 2019, the CHEOPS telescope in Earth’s orbit has demonstrated its functionality and precision beyond expectations. During this time, it has revealed the characteristics of numerous fascinating planets beyond our Solar System (exoplanets) and has become a key instrument for astronomers in Europe and worldwide.

Sunday, September 11, 2022

Planting trees is not always an effective way of binding carbon dioxide

Test site where extra carbon dioxide is emitted to the air and the biomass growth is measured in the plants.
Photo credit: Louise C Andresen

Tree-planting has been widely seen as an effective way of binding carbon as carbon dioxide levels rise in the atmosphere. But now researchers from the University of Gothenburg and elsewhere are warning that forests on nutrient-poor land won’t be an additional carbon sink in the long term. As forests age, their uptake of CO2 declines and, each time forests are planted, there is a risk of additional carbon being released from the soil.

The capacity of plants to bind carbon is a key factor in calculating the effects of climate change as carbon dioxide levels rise in the atmosphere.

Scientists have now measured how much biomass grows under air with elevated CO2 concentrations in several long-term field experiments. Growth stimulation was poor or missing when the plants lived in poor soil, in some cases after only ten years.

“The total biomass that binds carbon was not stimulated more by the elevated CO2 levels in our experiments over time. Exactly when growth slowed down depended on various factors, but one important one was how much nitrogen the soil contained,” says Louise Andresen, a researcher at the University of Gothenburg.

Agriculture drives over 90% of deforestation in the tropics

Recently destroyed cattle pasture
Credit: Chalmers University of Technology, Toby Gardner

A new study published in leading journal, Science, finds that between 90 and 99 percent of all deforestation in the tropics is driven directly or indirectly by agriculture. Yet only half to two-thirds of this results in the expansion of active agricultural production on the deforested land.

The study is a collaboration between many of the world’s leading deforestation experts and provides a new synthesis of the complex connections between deforestation and agriculture, and what this means for current efforts to drive down forest loss.

Following a review of the best available data, the new study shows that the amount of tropical deforestation driven by agriculture is higher than 80 percent, the most commonly cited number for the past decade.

This comes at a crucial time following the Glasgow Declaration on Forests at COP26 and ahead of the UN Biodiversity Conference (COP15) later this year and can help ensure that urgent efforts to tackle deforestation are guided and evaluated by an evidence base fit for purpose.

“Our review makes clear that between 90 and 99 percent of all deforestation in the tropics is driven directly or indirectly by agriculture. But what surprised us was that a comparatively smaller share of the deforestation – between 45 and 65 percent –​​ results in the expansion of actual agricultural production on the deforested land. This finding is of profound importance for designing effective measures to reduce deforestation and promote sustainable rural development”, says Florence Pendrill, lead author of the study at Chalmers University of Technology, Sweden.

Climate change is affecting drinking water quality

The Rappbode reservoir in the Harz region is surrounded by forests and is the largest drinking water reservoir in Germany.
Photo credit: André Künzelmann/UFZ

The water stored in reservoirs ensures our supply of drinking water. Good water quality is therefore important - but is at significant risk due to climate change. In a model study of the Rappbode reservoir in the Harz region, a research team from the Helmholtz Centre for Environmental Research (UFZ) demonstrated how the climate-related disappearance of forests in the catchment area for Germany's largest drinking water reservoir can affect water quality. The problem of such indirect consequences of climate change is seriously underestimated, the scientists warn in Water Research. Water quality is of critical importance, especially for drinking water reservoirs, as subsequent treatment in the waterworks must continually meet high standards.

Heat waves, drought, floods, forest fires - the consequences of climate change are increasing and are changing our environment. A prime example is the countryside in the catchment area for the Rappbode reservoir in the eastern Harz region. This is the largest drinking water reservoir in Germany and provides drinking water for roughly one million people. Long periods of drought over the years from 2015 to 2020 have so severely weakened the tree population in the Harz region that parasites such as bark beetles have been able to propagate. This further exacerbated the effect: The trees were further damaged and quickly died off. "Over the past four years, the Rappbode catchment area, characterized by conifers, primarily spruce, has lost over 50 percent of its forest," says UFZ hydrologist and last author Prof. Michael Rode. "This massive forest dieback is advancing rapidly and is dramatic. This will have consequences for the drinking water reservoir."

Researchers develop plastic film that can kill viruses using room lights

Credit: Queen's University Belfast

The self-sterilizing film is the first of its kind – it is low cost to produce, can be readily scaled and could be used for disposable aprons, tablecloths, and curtains in hospitals.

It is coated with a thin layer of particles that absorb UV light and produce reactive oxygen species – ROS. These kill viruses, including SARS2.

The technology used to create the film also ensures it is degradable - unlike the current disposable plastic films it would replace, which is much more environmentally friendly.

The breakthrough could lead to a significant reduction in the transmission of viruses in healthcare environments but also in other settings that use plastic films – for example, food production factories.

The Queen’s researchers tested the film for anti-viral activity using four different viruses – two strains of influenza A virus, a highly-stable picornavirus called EMCV and SARS2 – exposing it to either UVA radiation or with light from a cool white light fluorescent lamp.

They found that the film is effective at killing all of the viruses - even in a room lit with just white fluorescent tubes.

Friday, September 9, 2022

Vaccine expected to induce strong monkeypox virus immune response, research shows

An electron microscope image of monkeypox virus particles.
Credit: Dr Jason A. Roberts, Head of Electron Microscopy and Structural Virology at The Royal Melbourne Hospital's Victorian Infectious Diseases Reference Laboratory, Doherty Institute.

New research suggests recommended vaccinia virus (VACV)-based vaccines will mount a robust immune response against the monkeypox virus observed in the current outbreak (MPXV-2022).

Since the new virus was first observed in early May 2022, over 52,000 cases have been confirmed in more than 90 countries, including Australia, where 124 cases have been diagnosed (confirmed and probable).

The study, co-led by University of Melbourne Professor Matthew McKay, ARC Future Fellow and Honorary Professor at the Peter Doherty Institute for Infection and Immunity, and Professor Ahmed Abdul Quadeer, Research Assistant Professor at the Hong Kong University of Science and Technology, was published in the international journal Viruses.

Weeks after the new strain emerged, the team undertook genomic research to find out if the genetic mutations observed in MPXV-2022 may affect vaccine-induced immune responses against monkeypox.

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.”

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