. Scientific Frontline

Monday, October 2, 2023

‘Impossible’ Millimeter Wave Sensor Has Wide Potential

This prototype millimeter-wave radar sensor developed at UC Davis is capable of measuring extremely small vibrations and movements while being energy-efficient and cheap to produce.
Photo Credit: Omeed Momeni/University of California, Davis

Researchers at the University of California, Davis, have developed a proof-of-concept sensor that may usher in a new era for millimeter wave radars. In fact, they call its design a “mission impossible” made possible.

Millimeter wave radars send fast-moving electromagnetic waves to targets to analyze their movement, position and speed from the waves bounced back. The benefits of millimeter waves are their natural sensitivity to small-scale movements and their ability to focus on and sense data from microscopic objects.

The new sensor uses an innovative millimeter wave radar design to detect vibrations a thousand times smaller, and changes in a target’s position one hundred times smaller, than a strand of human hair, making it better or on par with the world’s most accurate sensors. Yet unlike its peers, this one is the size of a sesame seed, is cheap to produce and features a long battery life.

Professor Omeed Momeni and his lab in the Department of Electrical and Computer Engineering led the effort. It is part of an ongoing project funded by the Foundation for Food & Agriculture Research, or FFAR, to develop a low-cost sensor capable of tracking the water status of individual plants. This new radar is the necessary steppingstone that proves it is possible. The work is published in the September 2023 issue of IEEE Journal of Solid-State Circuits.

Discrimination alters brain-gut ‘crosstalk,’ prompting poor food choices and increased health risks

Illustration Credit: julientromeur

People frequently exposed to racial or ethnic discrimination may be more susceptible to obesity and related health risks in part because of a stress response that changes biological processes and how we process food cues. These are findings from UCLA researchers conducting what is believed to be the first study directly examining effects of discrimination on responses to different types of food as influenced by the brain-gut-microbiome (BGM) system.

The changes appear to increase activation in regions of the brain associated with reward and self-indulgence – like seeking “feel-good” sensations from “comfort foods” – while decreasing activity in areas involved in decision making and self-control.

“We examined complex relationships between self-reported discrimination exposure and poor food choices, and we can see these processes lead to increased cravings for unhealthy foods, especially sweet foods, but also manifested as alterations in the bidirectional communication between the brain and the gut microbiome,” said Arpana Gupta, PhD, a researcher and co-director of the UCLA Goodman-Luskin Microbiome Center and the UCLA G. Oppenheimer Center for Neurobiology of Stress and Resilience.

Climate and human land use both play roles in Pacific island wildfires past and present

SMU fire scientist Christopher Roos
Photo Credit: Courtesy of  Southern Methodist University

It’s long been understood that human settlement contributes to conditions that make Pacific Islands more susceptible to wildfires, such as the devastating Aug. 8 event that destroyed the Maui community of Lahaina. But a new study from SMU fire scientist Christopher Roos published in the journal Nature Ecology & Evolution shows that climate is an undervalued part of the equation.

Roos, SMU environmental archaeologist and professor of anthropology, traveled with his team to the Sigatoka River valley in southwestern Fiji in 2013, where they collected charcoal and stable carbon isotopes from deep soil cores to understand historic patterns of fire activity in the area. Different plants have distinct carbon isotopic signatures, which can provide information about past plant communities.

The team found fires and fire-created grassy areas that predate human settlement by millennia and actively corresponded to droughts likely driven by a regularly occurring weather pattern known as El Niño. El Niño events can alter precipitation patterns worldwide, making environmental conditions more favorable for wildfires. The National Oceanic and Atmospheric Administration issued an El Niño advisory in June, announcing the latest arrival of the climate event that continues to influence weather worldwide.

Genetics of Attraction: Mate Choice in Fruit Flies

The fruit fly Drosophila melanogaster is a common model organism for studying sexual selection and evolution.
Photo Credit: Stefan Lüpold, UZH

Genetic quality or genetic compatibility? What do female fruit flies prioritize when mating? Researchers at the University of Zurich show that both factors are important at different stages of the reproductive process and that females use targeted strategies to optimize the fitness of their offspring.

Breeding female fruit flies face a difficult decision: do they mate with the male that has the best genes, or with the one whose genes best match their own? Evolutionary biologists from the University of Zurich and Concordia University have now investigated this question, because, as UZH professor Stefan Lüpold explains, “the processes underlying mate choice influence the evolution of male sexual characteristics and thus the variation within a population – not only in flies”.

Heavily mutated SARS-CoV-2 variant BA.2.86 not as resistant to antibodies as first feared

Image Credit: Fusion Medical Animation

Researchers at Karolinska Institutet who studied SARS-CoV-2 variant BA.2.86, found that the new variant was not significantly more resistant to antibodies than several other variants that are circulating. The study also showed that antibody levels to BA.2.86 were significantly higher after a wave of XBB infections compared to before, suggesting that the vaccines based on XBB should provide some cross-protection to BA.2.86.

"We engineered a spike gene that matches that of the BA.2.86 variant and tested the blood of Stockholm blood donors (specifically those donations made very recently) to see how effective their antibodies are against this new variant. We found that although BA.2.86 was quite resistant to neutralizing antibodies, it wasn't significantly more resistant than a number of other variants that are also circulating", says Daniel Sheward, lead author of the study and Postdoctoral researcher in Benjamin Murrell's team at the Department of Microbiology, Tumor and Cell Biology at Karolinska Institutet.

Dense Measurement Network Links Air Pollution and Common Agricultural Practice

Photo Credit: Yiğit KARAALİOĞLU

A group of international collaborators led by the Research Institute for Humanity and Nature (RIHN) team performed the first quantitative study of air pollution in the northwestern region of India using 29 low-cost and reliable instruments. Their study demonstrated the benefits of source region observations to link crop residue burning (CRB) and air pollution at local to regional scales.

Exposure to particulate matter less than 2.5 µm in diameter (popularly known as PM2.5) poses health hazards in cities worldwide. Although the major sources of PM2.5 are industrial, certain agricultural practices also contribute to the emission and formation of fine particles during certain seasons. CRB, a common practice in Punjab, Haryana and part of Indo-Gangetic Plain, occurs immediately after the paddy harvest in the post-monsoon period (September-November). CRB activities have increased in the past two decades partly due to rise in mechanized agriculture in the 1990s and delayed rice planting in Punjab and Haryana following the Preservation of Subsoil Water Act (2009).

Since 2010, the effects of CRB in Punjab and Haryana on the Delhi and its surrounding area (known as the national capital region - NCR) have been in the spotlight. Yet, no measurements of PM2.5 in the source regions have been conducted. To rectify this, a group of researchers conducted an intensive field campaign involving the states of Punjab, Haryana and the NCR from September 1 to November 30, 2022, using 29 Compact and Useful PM2.5 Instruments with Gas sensors (CUPI-Gs).

New material discovery could revolutionize rollout of global vaccinations

Photo Credit: RF._.studio

New raw vaccine materials that could make vaccines more accessible, sustainable, and ethical have been discovered.

Adjuvants are vaccine ingredients that boost a person’s immune response to a vaccine, providing greater protection against disease. One of the most prevalent adjuvant materials used in vaccines is squalene, which is typically sourced from shark livers.

Researchers at the University of Nottingham collaborated with the Access to Advanced Health Institute (AAHI) to identify synthetic alternatives to squalene that ensure sustainable, reliable, and ethical sourcing of adjuvant raw materials for vaccines moving forward.

New synthetic adjuvant materials were developed from commercially available methacrylate monomers, ensuring that a reliable supply of the material is continually available.

The combination of these adjuvant materials is scalable through catalytic chain transfer polymerization, a process that allows high levels of control over the molecular weight of the product polymer. Controlling the molecular weight is key to the use of adjuvant material in formulations for vaccines as it allows for purification in the manufacturing process and optimizes biological responses following immunization.

Friday, September 29, 2023

Ancient plant wax reveals how global warming affects methane in Arctic lakes

A 2014 field photo from Wax Lips Lake on northwest Greenland with the Greenland Ice Sheet in the background and three of the study authors (Jamie McFarlin, Everett Lasher, Yarrow Axford).
Photo Credit: Alex P. Taylor

By studying fossils from ancient aquatic plants, Northwestern University and University of Wyoming (UW) researchers are gaining a better understanding of how methane produced in Arctic lakes might affect — and be affected by — climate change.

In a new study, the researchers examined the waxy coatings of leaves preserved as organic molecules within sediment from the early-to-middle Holocene, a period of intense warming that occurred due to slow changes in Earth’s orbit 11,700 to 4,200 years ago. These wax biomarkers — which were once a part of common aquatic brown mosses — were preserved in sediment buried beneath four lakes in Greenland.

Monitoring changes in methane levels

By studying these biomarkers, the researchers discovered that past warming during the middle Holocene caused lakes across a wide range of Greenland’s climates to generate methane. Because methane is a more potent greenhouse gas than carbon dioxide, any changes in methane production with warming are important to understand.

New study shows signs of early creation of modern human identities

SapienCE researchers have publiched a new study which provides vital information about how and when we may have started developing modern human identities. Image showing excavation at Blombos Cave, South Africa.
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Resized Image using AI by SFLORG
Photo Credit: UiB, SapienCE

The study, which is newly published in the Journal of Human Evolution, confirms previous scant evidence, and supports a multistep evolutionary scenario for the culturalization of the human body.

Eye-catching shells made into ornaments

The new study is conducted by Francesco d'Errico, Karen Loise van Niekerk, Lila Geis and Christopher Stuart Henshilwood. The significant findings provide vital information about how and when we may have started developing modern human identities.

“The discovery of eye-catching unmodified shells with natural holes from 100 to 73 ka confirms previous scant evidence that marine shells were collected, taken to the site and, in some cases, perhaps worn as personal ornaments before a stage in which shells belonging to selected species were systematically, and intentionally perforated with suitable techniques to create composite beadworks”, van Niekerk says.

Similar shells have been found in North Africa, other sites in South Africa and the Mediterranean Levant, which means that the argument is supported by evidence from other sites, not just Blombos Cave.

Small but mighty new gene editor

Structural analysis and deep mutational scanning (DMS) of AsCas12f. The team used cryogenic electron microscopy, a method to look at the structure of biological molecules in high-resolution, to analyze AsCas12f and engineer their new version. The DMS “heatmap” illustrates how all single mutations affected genome-editing activity. Blue squares indicate an undesirable mutation, while red ones represent desirable changes. The darker the color, the greater the effect.
Illustration Credit: © Hino et al. 2023

A new CRISPR-based gene-editing tool has been developed which could lead to better treatments for patients with genetic disorders. The tool is an enzyme, AsCas12f, which has been modified to offer the same effectiveness but at one-third the size of the Cas9 enzyme commonly used for gene editing. The compact size means that more of it can be packed into carrier viruses and delivered into living cells, making it more efficient. Researchers created a library of possible AsCas12f mutations and then combined selected ones to engineer an AsCas12f enzyme with 10 times more editing ability than the original unmutated type. This engineered AsCas12f has already been successfully tested in mice and has the potential to be used for new, more effective treatments for patients in the future.

By now you have probably heard of CRISPR, the gene-editing tool which enables researchers to replace and alter segments of DNA. Like genetic tailors, scientists have been experimenting with “snipping away” the genes that make mosquitoes malaria carriers, altering food crops to be more nutritious and delicious, and in recent years begun human trials to overcome some of the most challenging diseases and genetic disorders. The potential of CRISPR to improve our lives is so phenomenal that in 2020, researchers Jennifer Doudna and Emmanuelle Charpentier, who developed the most precise version of the tool named CRISPR-Cas9, were awarded the Nobel Prize in chemistry.

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