. Scientific Frontline

Wednesday, October 12, 2022

Endangered fruit-eating animals play an outsized role in a tropical forest

A view of the Atlantic Forest in Brazil’s Rio de Janeiro state.
Credit: Adriano Gambarini/The Nature Conservancy

A new study by researchers at the University of Washington shows that losing a particular group of endangered animals — those that eat fruit and help disperse the seeds of trees and other plants — could severely disrupt seed-dispersal networks in the Atlantic Forest, a shrinking stretch of tropical forest and critical biodiversity hotspot on the coast of Brazil.

The findings, published Oct. 12 in the Proceedings of the Royal Society B, indicate that a high number of plant species in today’s Atlantic Forest rely on endangered frugivores — the scientific term for animals that eat primarily fruit — to help disperse their seeds throughout the forest. As a result, losing those endangered frugivores would leave a high proportion of plants without an effective means to disperse and regenerate — endangering these plants, reducing diversity in the Atlantic Forest and crippling critical portions of this ecosystem.

“Tropical forests contain this incredible diversity of trees,” said lead author Therese Lamperty, a UW postdoctoral researcher in biology. “One of the main processes forests use to maintain this diversity is dispersal. If you’re not dispersed, you’re in a crowd of trees that are just like you – all competing for resources. And there are a lot of plant enemies already in the area or that can be easily recruited, like harmful animals or plant diseases. Your chance of survival is higher when you get transported away from your mother tree to an area without trees like you.”

New study undermines the theory that depressed people are just more realistic

Photo credit: Hieu Van

Are depressed people simply more realistic in judging how much they control their lives, while others view the world through rose-colored lenses, living under the illusion that they have more control than they do?

That’s the general idea behind “depressive realism,” a theory that has held sway in science and popular culture for more than four decades.

The problem is, it’s just not true, new research finds.

“It’s an idea that exerts enough appeal that lots of people seem to believe it, but the evidence just isn’t there to sustain it,” says Professor Don Moore, the Lorraine Tyson Mitchell Chair in Leadership and Communication at UC Berkeley’s Haas School of Business and co-author of the study, in press at the journal Collabra:Psychology. “The good news is you don’t have to be depressed to understand how much control you have.”

Depressive realism

The concept of depressive realism stems from a 1979 study of college students examining whether they could predict how much control they had over whether a light turned green when they pushed a button. The original research concluded that the depressed students were better at identifying when they had no control over the lights, while those who weren’t depressed tended to overestimate their level of control.

U.S. Air Force Declares Initial Operational Capability of Sikorsky HH-60W Jolly Green II

The HH-60W Jolly Green II
Full Size Image
Credit: Lockheed Martin Corporation

The U.S. Air Force declared Initial Operational Capability (IOC) for the HH-60W Jolly Green II Combat Rescue Helicopter, validating the platform's operational readiness to forward deploy Air Force rescue crews around the globe. Sikorsky, a Lockheed Martin Company (NYSE: LMT) designed and manufactures the HH-60W, which enables the U.S. Air Force to conduct rescue missions at greater ranges and in the most challenging environments, and with increased survivability.

“This declaration is a vote of confidence from U.S. Air Force leadership and demonstrates the critical role of and need for the HH-60W,” said Nathalie Previte, vice president, Sikorsky Army & Air Force Systems. "Sikorsky is committed to continuing deliveries of the Department of Defense’s only dedicated combat search and rescue (CSAR) helicopter and to provide the most capable platform to rescue crews who depend on this aircraft day-in and day-out to conduct vital life-saving missions.”

Black Hole Spews Out Material Years After Shredding Star

Artist’s illustration of tidal disruption event AT2019dsg where a supermassive black hole spaghettifies and gobbles down a star. Some of the material is not consumed by the black hole and is flung back out into space. 
Resized Image using AI by SFLORG
Credit: DESY, Science Communication Lab

In October 2018, a small star was ripped to shreds when it wandered too close to a black hole in a galaxy located 665 million light years away from Earth. Though it may sound thrilling, the event did not come as a surprise to astronomers who occasionally witness these violent incidents while scanning the night sky.

But nearly three years after the massacre, the same black hole is lighting up the skies again — and it hasn’t swallowed anything new, scientists say.

“This caught us completely by surprise — no one has ever seen anything like this before,” says Yvette Cendes, a research associate at the Center for Astrophysics | Harvard & Smithsonian (CfA) and lead author of a new study analyzing the phenomenon.

The team concludes that the black hole is now ejecting material traveling at half of the speed of light, but are unsure why the outflow was delayed by several years. The results, described this week in the Astrophysical Journal, may help scientists better understand black holes’ feeding behavior, which Cendes likens to “burping” after a meal.

Viewing Earth from Space at Night: Tracking Our Changing Black Marble

Earth’s night lights as observed in 2016 based on NASA’s Black Marble Product.
Photo Credit: NASA

When the sun goes down and lights go on – or not — a multitude of data can be gathered by satellite from the night sky, giving insights into the dynamic human activities happening at the surface.

With remote sensing, things like land use changes, urban development, and forest management can be reliably and accurately measured by daylight. At nighttime, we can gather different kinds of data. One way to do this is with NASA’s Black Marble, a product suite that scans the sky each night and is powerful enough to sense all kinds of lights on the surface of Earth, from holiday lights to a single 12,000-lumen flashlight, from space.

However, the data gathered at night can be difficult to analyze says Department of Natural Resources and the Environment Assistant Professor and Director of the Global Environmental Remote Sensing (GERS) Laboratory Zhe Zhu. He explains nighttime satellite data can be influenced by many factors, which leads to a large degree of temporal variation, even for the well-calibrated NASA Black Marble data.

“The first time I looked at a time series of the data, I felt like it was almost impossible to use,” says Zhu.

A team of researchers from GERS including Zhu and NRE Ph.D. student Tian Li, along with researchers from NASA and the University of Maryland Earth System Science Interdisciplinary Center has developed a method that is capable of providing daily global moderate resolution nighttime light change maps. The results are published in the journal Remote Sensing of Environment.

Thirdhand smoke can trigger skin diseases

Skin is the largest organ to contact thirdhand smoke and may thus receive the greatest exposure

Thirdhand smoke, or THS, comprises the residual pollutants from tobacco smoke that remain on surfaces and in dust after tobacco has been smoked. It can remain on indoor surfaces indefinitely, causing potentially harmful exposure to both smokers and non-smokers.

A team led by researchers at the University of California, Riverside, has found that acute exposure of the skin to THS elevates biomarkers associated with the initiation of skin diseases, such as contact dermatitis and psoriasis.

“We found exposure of human skin to THS initiates mechanisms of inflammatory skin disease, and elevates urinary biomarkers of oxidative harm, which could lead to other diseases, such as cancer, heart disease, and atherosclerosis,” said Shane Sakamaki-Ching, a former graduate student at UC Riverside who graduated with a doctoral degree in cell, molecular, and developmental biology in March 2022. “Alarmingly, acute dermal exposure to THS mimics the harmful effects of cigarette smoking.”

The study, published in eBioMedicine of The Lancet family of journals, is the first to be performed on humans exposed dermally to THS.

Study explores links between people taking multiple medications and dementia

Photo credit: Ksenia Yakovleva

People with dementia are likely to have taken more than three medications for other health conditions in the five years directly before their diagnosis, according to new research.

The study is the first to provide an in-depth exploration of the links between evolving polypharmacy – which involves a patient being prescribed more than one drug at any given time – and a dementia diagnosis.

Published in the Aging and Disease journal, it is based on an analysis of the records of more than 33,000 dementia patients in Wales between 1990 to 2015.

Experts in e-health used machine learning techniques to identify potentially damaging patterns in a patient’s medicine usage, and how these patterns evolve in the run-up to diagnosis.

They found that in the 20 years leading up to them being diagnosed, the proportion of patients taking three or more medications rose from 5.5% (for the period 16 to 20 years prior to diagnosis) to 82.16% among those less than five years from a diagnosis.

An AI model reveals how the body’s defense system recognizes skin cancer

Boosting the body’s own defense system has proven to be a particularly effective therapy for skin cancer.
Photo credit: National Cancer Institute

The artificial intelligence model could be utilized to enable more effective care for skin cancer patients and could lead to similar breakthroughs in the diagnosis and treatment of other cancers.

Researchers from the University of Helsinki, HUS Comprehensive Cancer Center, Aalto University and Stanford University have developed an artificial intelligence model that predicts which skin cancer patients will benefit from a treatment that activates the immune defense system. In practice, the AI model makes it possible to diagnose skin cancer with a blood test, determine the prognosis and target therapies increasingly accurately.

The skin cancer–related study was published in the esteemed Nature Communications journal.

The right medication for the right patient

Boosting the body’s own defense system has proven to be a particularly effective therapy for skin cancer. The problem with therapies that activate the immune system are the differences between patient groups: while some patients can be said to be cured, others gain no benefit from the treatment at all.

“Prior research has been unable to provide doctors with tools that would predict who will benefit from treatment that activates the defense system. The correct targeting of therapies is extremely important, since drug therapies are expensive and serious adverse effects fairly common,” says doctor and Doctoral Researcher Jani Huuhtanen from the University of Helsinki and Aalto University.

Scientists Improve Inexpensive Perovskite Photocells

Simulated atomic structure of perovskite after calcium doping.
Illustration: Danil Bukhvalov

UrFU scientists have found a way to protect perovskite solar cells based on lead-methylammonium iodide (a promising alternative to traditional silicon photovoltaic cells) from degradation by water, such as rain. They found that partial replacement of lead with other alkaline earth metals protects them from such degradation, and also increases the parts of the visible spectrum of radiation involved in the process of generating electrons. An article on the results of the study was published in the Journal of Solid State Chemistry. The research was financially supported by the Ministry of Education and Science of Russia under the Priority 2030 development program of Ural Federal University.

Perovskite solar cells based on lead-methylammonium iodide are superior to silicon cells in performance and ease of synthesis. They are also capable of effectively generating electricity in cloudy or foggy conditions, so they are ideal for use in Russia or countries with similar climates. However, a complete switch to perovskite solar panels is not possible due to a number of reasons causing instability of such photovoltaic cells.

One of the causes of instability is that the compound is unstable to contact with water or other organic solvents. If it rains on the photocell, the compound begins to degrade rapidly, destroying its structure. Scientists determined that replacing lead with metals such as calcium, barium, or strontium would protect the compound from rapid degradation.

Tuesday, October 11, 2022

Graphene Boosts Flexible and Wearable Electronics


At 200 times stronger than steel, graphene has been hailed as a super material of the future since its discovery in 2004. The ultrathin carbon material is an incredibly strong electrical and thermal conductor, making it a perfect ingredient to enhance semiconductor chips found in many electrical devices.

But while graphene-based research has been fast-tracked, the nanomaterial has hit roadblocks: in particular, manufacturers have not been able to create large, industrially relevant amounts of the material. New research from the laboratory of Nai-Chang Yeh, the Thomas W. Hogan Professor of Physics, is reinvigorating the graphene craze.

In two new studies, the researchers demonstrate that graphene can greatly improve electrical circuits required for wearable and flexible electronics such as smart health patches, bendable smartphones, helmets, large folding display screens, and more.

In one study, published in ACS Applied Materials & Interfaces, the researchers grew graphene directly onto thin two-dimensional copper lines commonly used in electronics. The results showed that the graphene not only improved the lines' conducting properties but also protected the copper-based structures from usual wear and tear. For instance, they showed that graphene-coated copper structures could be folded 200,000 times without damage, as compared to the original copper structures, which started cracking after 20,000 folds. The results demonstrate that graphene can help create flexible electronics with longer lifetimes.

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