Fertilizers limit pollination by changing how bumblebees sense flowers

Photo Credit: Myriams-Fotos

Pollinators are less likely to land on flowers sprayed with fertilizers or pesticides as they can detect electric field changes around the flower, researchers at the University of Bristol have found.

The study, published in PNAS Nexus today, shows that chemical sprays alter the electric field around flowers for up to 25 minutes after exposure. This impact lasts substantially longer than natural fluctuations, such as those caused by wind, and causes a reduction in bee feeding effort in nature.

Dr Ellard Hunting of Bristol’s School of Biological Sciences and his team noted that fertilizers did not affect vision and smell, and set out to mimic the electrical changes caused by fertilizers and pesticides in the field by electrically manipulating flowers. This showed that bumblebees were able to detect and discriminate against the small and dynamic electric field alterations that are caused by the chemicals.

Dr. Ellard Hunting said: “We know that chemicals are toxic, but we know little about how they affect the immediate interaction between plants and pollinators.

“Flowers have a range of cues that attract bees to promote feeding and pollination. For instance, bees use cues like flower odor and color, but they also use electric fields to identify plants.

Natural carbon dioxide reduction implemented faster and with less risk than high-tech approaches

Researchers have investigated the potential of various carbon dioxide removal processes. 
Photo Credit: Shameer Pk

Carbon dioxide can be removed from the atmosphere by natural or technical means. Natural sinks such as peatlands can be restored, and innovative technologies already exist to extract carbon from the air. Researchers from the Helmholtz Climate Initiative's Net Zero 2050 Cluster have identified the approaches with the highest potential for carbon removal in Germany. They show that natural sinks can be expanded in the short term, while high-tech approaches can reduce greenhouse gases only in the medium term and carry potential risks.

To reach the targets of the Paris agreement and limit global warming to 1.5 to 2 degrees Celsius, simply reducing our carbon dioxide (CO2) emissions will probably not be enough, and it will likely be necessary to additionally remove CO2 from the atmosphere. Such CO2 removal could be realized naturally through natural sink enhancement (NSE) such as forest reforestation, or through new technologies which use chemical processes for carbon capture. However, the potential and feasibility of these so-called carbon dioxide removal (CDR) measures depend on many variables, like the availability of infrastructure and resources such as land and energy, to name a few.

A new nanoparticle to act at the heart of cells

This electron micrograph documents the porous nature of silica nanoparticles. These pores are large enough to allow entrance of a large number of NSA molecules. Here, they are protected until being taken up by the immune cells. At this point NSA is released and can stop the inflammatory processes.
Credit: UNIGE - Carole Bourquin

How can a drug be delivered exactly where it is needed, while limiting the risk of side effects? The use of nanoparticles to encapsulate a drug to protect it and the body until it reaches its point of action is being increasingly studied. However, this requires identifying the right nanoparticle for each drug according to a series of precise parameters. A team from the University of Geneva (UNIGE) and the Ludwig Maximilians Universität München (LMU) has succeeded in developing a fully biodegradable nanoparticle capable of delivering a new anti-inflammatory drug directly into macrophages - the cells where uncontrolled inflammatory reactions are triggered - ensuring its effectiveness. In addition, the scientists used an invitro screening methodology, thus limiting the need for animal testing. These results, recently published in the Journal of Controlled Release, open the way to an extremely powerful and targeted anti-inflammatory treatment.

Inflammation is an essential physiological response of the body to defend itself against pathogens such as bacteria. It can, however, become problematic when it turns into a chronic condition, such as in cancers, autoimmune diseases or certain viral infections. Many treatments already exist, but their action is often not very targeted, high doses are required and deleterious side effects are frequent. Macrophages, large immune cells whose natural function is to absorb pathogens and trigger inflammation to destroy them, are often involved in inflammatory diseases. When overactivated, they trigger an excessive inflammatory response that turns against the body instead of protecting it.

Study uncovers widespread and ongoing clearcutting of Swedish old forests

Photo Credit: Ulrika Ervander

Almost one fourth of Sweden’s last unprotected old-growth forest was logged between 2003 and 2019. At this rate, all of these ecologically unique and valuable forests will be lost in about 50 years. These findings add to the growing body of evidence for widespread cryptic forest degradation across the global north.

A small fraction of Sweden’s forests consists of older forests which have never previously been clear-cut. These rare ecosystems have a rich biodiversity and give us a valuable glimpse into the functioning of natural northern landscapes before widespread human interventions.

A new study published in the journal Earth’s Future has uncovered evidence that almost a quarter of the few remaining forests of this type were lost between 2003 and 2019, equivalent to a loss of 1.4% per year. "This land use change is not well documented across all northern countries. Its thanks to a uniquely rich dataset we could investigate this issue for Sweden and get such clear results, says Anders Ahlström, Associate Professor at Lund University, Sweden.

In the study, the research team paired Swedish national forest inventory data on forest age from more than 90 000 forest inventory plots with a government database documenting almost a million individual clear-cuts since 2003.

Novel Nanowire Fabrication Technique Paves Way for Next Generation Spintronics

The challenge of fabricating nanowires directly on silicon substrates for the creation of the next generation of electronics has finally been solved by researchers from Tokyo Tech. Next-generation spintronics will lead to better memory storage mechanisms in computers, making them faster and more efficient.

As our world modernizes faster than ever before, there is an ever-growing need for better and faster electronics and computers. Spintronics is a new system which uses the spin of an electron, in addition to the charge state, to encode data, making the entire system faster and more efficient. Ferromagnetic nanowires with high coercivity (resistance to changes in magnetization) are required to realize the potential of spintronics. Especially L10-ordered (a type of crystal structure) cobalt–platinum (CoPt) nanowires.

Conventional fabrication processes for L10-ordered nanowires involve heat treatment to improve the physical and chemical properties of the material, a process called annealing on the crystal substrate; the transfer of a pattern onto the substrate through lithography; and finally, the chemical removal of layers through a process called etching. Eliminating the etching process by directly fabricating nanowires onto the silicon substrate would lead to a marked improvement in the fabrication of spintronic devices. However, when directly fabricated nanowires are subjected to annealing, they tend to transform into droplets as a result of the internal stresses in the wire.

Low levels of air pollution deadlier than previously thought

Photo Credit: Ralf Vetterle

The World Health Organization’s most recent estimates (2016) are that over 4.2 million people die prematurely each year due to long-term exposure to fine particulate outdoor air pollution (often referred to as PM2.5,). A recent study involving McGill researchers now suggests that the annual global death toll from outdoor PM2.5 may be significantly higher than previously thought. That’s because the researchers found that mortality risk was increased even at very low levels of outdoor PM2.5, ones which had not previously been recognized as being potentially deadly. These microscopic toxins cause a range of cardiovascular and respiratory diseases and cancers.

“We found that outdoor PM2.5 may be responsible for as many as 1.5 million additional deaths around the globe each year because of effects at very-low concentrations that were not previously appreciated,” said Scott Weichenthal, an Associate Professor in the Department of Epidemiology, Biostatistics, and Occupational Health at McGill University and the lead author on the recent paper in Science Advances.

Tracing tomatoes’ health benefits to gut microbes

The tomatoes used in the study were developed at Ohio State and are the type typically found in canned tomato products.
Photo Credit: Couleur

Two weeks of eating a diet heavy in tomatoes increased the diversity of gut microbes and altered gut bacteria toward a more favorable profile in young pigs, researchers found.

After observing these results with a short-term intervention, the research team plans to progress to similar studies in people, looking for health-related links between tomatoes in the diet and changes to the human gut microbiome – the community of microorganisms living in the gastrointestinal tract.

“It’s possible that tomatoes impart benefits through their modulation of the gut microbiome,” said senior author Jessica Cooperstone, assistant professor of horticulture and crop science and food science and technology at The Ohio State University.

“Overall dietary patterns have been associated with differences in microbiome composition, but food-specific effects haven’t been studied very much,” Cooperstone said. “Ultimately we’d like to identify in humans what the role is of these particular microorganisms and how they might be contributing to potential health outcomes.”

UQ study explains link between sleep apnea and dementia

Professor Elizabeth Coulson said the findings suggest CPAP treatment of obstructive sleep apnea has the potential to reduce dementia risk.
Credit: University of Queensland

Researchers at The University of Queensland have discovered a link between obstructive sleep apnea and an increased risk of developing dementia.

Professor Elizabeth Coulson from UQ’s Queensland Brain Institute and School of Biomedical Sciences and her team found a causal relationship between a lack of oxygen to the brain during sleep and Alzheimer’s disease in mice.

“We found sleep deprivation alone in mice caused only mild cognitive impairment,” Professor Coulson said.

“But we developed a novel way to induce sleep-disrupted breathing and found the mice displayed exacerbated pathological features of Alzheimer’s disease.

“It demonstrated that hypoxia – when the brain is deprived of oxygen – caused the same selective degeneration of neurons that characteristically die in dementia.”

Professor Coulson said the next step would be to determine what levels of hypoxia result in brain degeneration in humans.

New quantum phase discovered for developing hybrid materials

 Metropolitan University Scientists have discovered that in Ba1-xSrxAl2O4, a highly disordered atomic arrangement is formed in the AlO4 network at chemical compositions near the structural quantum critical point, resulting in both characteristics of crystalline and amorphous materials.
Illustration Credit: Yui Ishii, Osaka

Scientists discovered a hybrid state in which crystals exhibit both crystalline and amorphous characteristics near the structural quantum critical point.

If you have ever watched water freeze to ice, you have witnessed what physicists call a “phase transition.” Osaka Metropolitan University scientists have discovered an unprecedented phase transition during which crystals achieve amorphous characteristics while retaining their crystalline properties. Their findings contribute to developing hybrid materials for use in harsh environments, such as outer space. The results were published in Physical Review B.

A typical phase transition exhibited by crystalline solids involves a change in the crystal structure. Such structural phase transitions usually occur at finite temperatures. However, controlling the chemical composition of the crystal can lower the transition temperature to absolute zero (−273°C). The transition point at absolute zero is called the structural quantum critical point.

Old Bone Links Lost American Parrot to Ancient Indigenous Bird Trade

A thick-billed parrot.
Photo Credit: U.S. Fish and Wildlife.

For centuries, Indigenous communities in the American Southwest imported colorful parrots from Mexico. But according to a study led by The University of Texas at Austin, some parrots may have been captured locally and not brought from afar.

The research challenges the assumption that all parrot remains found in American Southwest archaeological sites have their origins in Mexico. It also presents an important reminder: The ecology of the past can be very different from what we see today.

“When we deal with natural history, we can constrain ourselves by relying on the present too much,” said the study’s author, John Moretti, a doctoral candidate at the UT Jackson School of Geosciences. “These bones can give us kind of a baseline view of the animal life of the ecosystems that surrounded us before huge fundamental changes that continue today began.”

The study was published in print in the September issue of The Wilson Journal of Ornithology.