. Scientific Frontline

Friday, December 10, 2021

Novel model can aid decisions in electricity generation, stream water quality

A student working in a geosciences class with Susan L. Brantley, Barnes Professor of Geosciences, takes a water sample in central Pennsylvania. Students in the class noticed that some streams near power plants showed improvements in water quality and thought that power plants switching from coal to natural gas may explain the positive results. A Penn State-led research team developed a novel model to detect if power plants shifting from coal to natural gas is affecting stream water quality regionally. Credit: Susan Brantley / Penn State

Switching from coal to natural gas in power plants can reduce how much sulfur dioxide, a gas that smells like a freshly struck match, is emitted into the atmosphere and ultimately how much sulfate pollution enters waterways, according to a Penn State-led research team that has developed a model to detect if the recent switch from coal to gas is affecting streams.

“The number of power plants switching from coal to natural gas is increasing, and sulfur dioxide emissions in Pennsylvania and across the United States are decreasing dramatically,” said Xianzeng Niu, assistant research professor in Penn State’s Earth and Environmental Systems Institute (EESI). “Both technology and the shift of fuels have contributed to this trend. We wanted to look at how this trend has affected water quality.”

Coal- and natural gas-burning power plants emit sulfur dioxide into the atmosphere, but coal has a much higher sulfur content than natural gas and releases more sulfur dioxide when burned. The sulfur particles eventually fall back down to earth and can acidify streams. Too much sulfur, which enters waterways in the form of sulfate, can cause water chemistry to become harmful to ecosystems.

Almost two-thirds of species at deep-sea hydrothermal vents are at risk of extinction

Image of a deep-sea Hydrothermal Vent taken by a Remotely Operate Vehicle (ROV).
Photo credit to Marum Universitat Bremen.

New research from Queen’s University Belfast has led to 184 deep-sea species being added to the global Red List of Threatened Species. With almost two-thirds of the species assessed listed as threatened, it highlights the urgent need to protect them from extinction.

The International Union for Conservation of Nature (IUCN)’s Red List of Threatened Species is the world’s foremost conservation authority, with universally recognized extinction risk categories (e.g. Endangered, Critically Endangered, etc.) used to raise awareness of species’ conservation needs to industry, policy makers, and the general public. More than 140,000 species have been Red Listed but less than 15% are from marine environments and barely any are from the deep sea.

The deep sea is the largest environment on earth with thousands of unique species living in extreme habitats. The remoteness of these seafloor habitats means they are often understudied, making it difficult to understand and communicate their conservation requirements.

Hydrothermal vents are just one of these unique deep-sea ecosystems. Vent habitats host a similar density of life as tropical rainforests and coral reefs. There are approximately 600 of these hotspots known worldwide and most are one-third of a football field in size. Vent communities are also distinctly different from the surrounding seafloor, making these highly insular habitats.

Dinosaurs’ Last Spring: Study Pinpoints Timing of Asteroid Impact

Credit: Florida Atlantic University/Getty Images

A groundbreaking study led by researchers at Florida Atlantic University and an international team of scientists conclusively confirms the time year of the catastrophic Chicxulub asteroid, responsible for the extinction of dinosaurs and 75 percent of life on Earth 66 million years ago. Springtime, the season of new beginnings, ended the 165-million-year reign of dinosaurs and changed the course of evolution on Earth. 

Robert DePalma (left) and Anton Oleinik, Ph.D. at the site in North Dakota.
Credit: Florida Atlantic University
Results of the study, published in the journal Scientific Reports , greatly enhances the ability to trace the first stages of damage to life on Earth. FAU’s Robert DePalma, senior author and an adjunct professor in the Department of Geosciences, Charles E. Schmidt College of Science, and a doctoral student at the University of Manchester; and Anton Oleinik, Ph.D., second author and an associate professor, FAU’s Department of Geosciences, contribute to a major scientific advancement in the ability to understand the massive impact that brought an end to the dinosaurs.

“Time of year plays an important role in many biological functions such as reproduction, feeding strategies, host-parasite interactions, seasonal dormancy, and breeding patterns,” said DePalma. “Hence, it is no surprise that the time of year for a global-scale hazard can play a big role in how harshly it impacts life. The seasonal timing of the Chicxulub impact has therefore been a critical question for the story of the end-Cretaceous extinction. Until now, the answer to that question has remained unclear.”

Thursday, December 9, 2021

A new super-cooled microwave source boosts the scale-up of quantum computers

Artistic impression of an on-chip microwave source controlling qubits.
Credit: Aleksandr Kakinen
A newly designed microwave source could replace existing bulky control systems that hinder the scalability of quantum computers

A research consortium led by Aalto University and VTT Technical Research Centre of Finland has now developed a key component of the solution to this conundrum. ‘We have built a precise microwave source that works at the same extremely low temperature as the quantum processors, approximately -273 degrees,’ says Mikko Möttönen, Professor at Aalto University and VTT Technical Research Centre of Finland, who led the team.

The new microwave source is an on-chip device that can be integrated with a quantum processor. Less than a millimeter in size, it potentially removes the need for high-frequency control cables connecting different temperatures. With this low-power, low-temperature microwave source, it may be possible to use smaller cryostats while still increasing the number of qubits in a processor.

‘Our device produces one hundred times more power than previous versions, which is enough to control qubits and carry out quantum logic operations,’ says Möttönen. ‘It produces a very precise sine wave, oscillating over a billion times per second. As a result, errors in qubits from the microwave source are very infrequent, which is important when implementing precise quantum logic operations.’

However, a continuous-wave microwave source, such as the one produced by this device, cannot be used as is to control qubits. First, the microwaves must be shaped into pulses. The team is currently developing methods to quickly switch the microwave source on and off.

Atomic structure of antifungal drug confirms unusual mechanism, opens door to less-toxic derivatives

Illinois chemistry professor Martin Burke co-led a team that mapped the unusual aggregate structure of the antifungal drug amphotericin B, illuminating the path to develop less-toxic forms of the drug.  Photo by L. Brian Stauffer
Advanced molecular imaging technology has now mapped the structure of a drug widely used to treat fungal infections but whose workings have mystified researchers and physicians for nearly 70 years.

In a new study, researchers at the University of Illinois Urbana-Champaign, the University of Wisconsin, Madison and the National Institutes of Health described in atomistic detail the structure of the drug amphotericin B, a powerful but toxic antifungal agent.

Seeing the structure provides illumination in the researchers’ quest to formulate less-toxic AmB derivatives, said Dr. Martin D. Burke, a professor of chemistry at Illinois and a member of the Carle Illinois College of Medicine, as well as a medical doctor. Burke co-led the study with Chad Rienstra, a Wisconsin professor of biochemistry, and Taras Pogorelov, an Illinois research professor of chemistry. The researchers reported their findings in the journal Nature Structural & Molecular Biology.

“It’s like we were driving in the dark at night, and all of a sudden we were able to put the lights on. With the clarity of this structure, we can see where we need to go to reach our goal of a less-toxic antifungal drug,” Burke said.

Previously, researchers and physicians thought that AmB killed fungal cells by forming channels in the cell membrane, the outer envelope that encases the cell. However, in 2014, while Rienstra was a professor at Illinois, Burke and Rienstra’s group found that amphotericin primarily kills cells by robbing the membrane of sterol molecules – cholesterol in human cells and ergosterol in fungal cells. Individual amphotericin molecules aggregated into a larger structure that absorbed sterol molecules out of cell membranes like a sponge, causing the cells to die.

Stretchy, washable battery brings wearable devices closer to reality

Dr. Ngoc Tan Nguyen and his colleagues have created a battery that is both flexible and washable. It works even when twisted or stretched to twice its normal length, or after being washed multiple times. Photo credit: Kai Jacobson

UBC researchers have created what could be the first battery that is both flexible and washable. It works even when twisted or stretched to twice its normal length, or after being tossed in the laundry.

“Wearable electronics are a big market and stretchable batteries are essential to their development,” says Dr. Ngoc Tan Nguyen (he/him), a postdoctoral fellow at UBC’s faculty of applied science. “However, up until now, stretchable batteries have not been washable. This is a critical addition if they are to withstand the demands of everyday use.”

The battery developed by Dr. Nguyen and his colleagues offers a number of engineering advances. In normal batteries, the internal layers are hard materials encased in a rigid exterior. The UBC team made the key compounds—in this case, zinc and manganese dioxide—stretchable by grinding them into small pieces and then embedding them in a rubbery plastic, or polymer. The battery comprises several ultra-thin layers of these polymers wrapped inside a casing of the same polymer. This construction creates an airtight, waterproof seal that ensures the integrity of the battery through repeated use.

New State of Matter: Crystalline and Flowing at the Same Time

Cluster crystals consist of a core of organic polymers surrounded by DNA molecules (right). Pressed together (left), they exhibit properties of crystals and liquids at the same time.
© Natasa Adzic, University of Vienna

More than 20 years ago, researchers predicted that with sufficiently high density certain particles of matter would form a new state of matter that features the properties of both crystalline solids and flowing liquids. Scientists from Forschungszentrum Jülich, the University of Siegen, and the University of Vienna have now succeeded in creating this state in a laboratory. Their experimental concept opens up the possibility for further development and could pave the way for further discoveries in the world of complex states of matter.

Through their research efforts, the team was able to finally disprove an intuitive assumption that in order for two particles of matter to merge and form larger units (i.e. aggregates or clusters), they must be attracted to each other. As early as the turn of the century, a team of soft matter physicists headed by Christos Likos of the University of Vienna predicted on the basis of theoretical considerations that this does not necessarily have to be the case. They suggested that purely repulsive particles could also form clusters, provided they are fully overlapping and that their repulsion fulfils certain mathematical criteria.

A new layer-by-layer built inorganic-organic material enables optical switching of magnetic properties

Materials chemists have developed a facile process for piling ultrathin inorganic and organic layers in a pre-designed manner into flexible room-temperature thin-film magnets, whose magnetic properties can be controlled with successive external light illuminations.

In the big data era, photo-controlled room-temperature magnets could open new horizons for high-density information storage, in particular, if these materials could be synthesized from non-critical raw materials and fabricated in device-integrable thin-film form. Now a team of Aalto University researchers from the Department of Chemistry and Material Science and the Department of Applied Physics report such dream-of-the-dream materials.

For the material fabrication, the Aalto researchers utilize the Millennium Prize awarded ALD (atomic layer deposition) technology, which they have modified so that within the ALD-grown ferrimagnetic inorganic layers ultrathin photo-switchable organic layers can be deposited through additional MLD (molecular layer deposition) cycles.

The inorganic component harnessed by the researchers into these thin films is unique itself, as it possesses an extremely high magnetic coercivity field, but is at the same time really simple in its chemical composition, being composed of iron and oxygen only.

Silvopasture could tackle Colombian Amazon’s high deforestation rates

Silvopastoral farming, where trees and forage plants are planted in livestock pasture, may support biodiversity and offer solutions to high deforestation rates, according to a new University of Bristol-led study that investigated the effects of the farming method across farms in Colombia, South America.

A transition to silvopastoral systems (SPS), when implemented in a participatory way where farmers can decide how the system is adopted in their farms and make commitments to conserve remnant forests, could help Colombia meet its greenhouse gas emissions targets for 2030 and protect the country’s Amazonian forests.

Over the last 20 years, Colombia — the second most biodiverse country in the world, has lost more than 4.6million hectares of forest, partly due to the expansion of cattle farming, which in turn is related to complex historical, economic and political reasons. While a range of national and international agri-environmental projects aimed at reducing deforestation levels have been implemented in Colombia, until now their uptake and efficacy was not known.

The BioSmart project, comprising entomologists, economists, geographers, climate modelers and botanists, sought to assess biodiversity value in silvopasture compared with non-SPS conventional pasture sites. The team recorded the number of insects and plant species across 16 SPS farm sites in Caquetá, Colombia. An Amazonian department which experiences particularly high levels of deforestation where 6,883km2 of forest was cleared between 2000-2020, equivalent to 8.5% of the region’s total forest-covered land.

Key surveys overestimate COVID-19 vaccination rates in the USA

Estimates of COVID-19 vaccine uptake in the USA based on large surveys that are used to guide policy-making decisions tend to overestimate the number of vaccinated individuals, research published in Nature suggests.

In the USA, the CDC (Centers for Disease Control and Prevention) compiles data on national vaccine uptake, but reporting can sometimes be delayed. Surveys that measure attitudes and behavior towards COVID-19 vaccines can fill a gap when there is a lag in real-time data, and can inform government responses to the epidemic. However, some surveys diverge substantially in their findings.

The authors of a new paper published in Nature today find that in May 2021, Delphi–Facebook’s COVID-19 symptom tracker (250,000 responses per week) overestimated vaccine uptake by 17 percentage points, and a survey from the US Census Bureau (75,000 responses per wave) overestimated vaccine uptake by 14 percentage points compared to benchmark estimates from the CDC.

These overestimation errors go orders of magnitude beyond the statistical uncertainty provided by the surveys. A survey by Axios–Ipsos also overestimated uptake, but by a smaller amount (4.2 percentage points in May 2021)—despite being the smallest survey (about 1,000 responses per week). These findings indicate that bigger is not always better when it comes to datasets, if we fail to account for data quality.

The authors note that COVID-19 vaccine uptake was not the primary focus of any of the surveys. For example, Delphi-Facebook intends to measure changes in COVID-related behaviors over time. However, the bias in estimates of vaccine uptake in the two large surveys indicates that they are not representative of the US adult population. Lack of statistical representativeness may also be causing bias in other survey outcomes they suggest.

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