Wednesday, November 24, 2021

Water disinfection byproduct disrupts reproductive hormones, damages pituitary in female mice

A byproduct formed during water disinfection disrupts hormones
that regulate reproduction in female mice, found Illinois
professor Lori Raetzman (left) and graduate student Rachel Gonzalez. 
Photo by L. Brian Stauffer
Chemical disinfection makes water from both natural sources and wastewater streams drinkable; however, the process also creates byproducts, not all of which are understood or regulated. A new study from University of Illinois Urbana-Champaign researchers has found that one byproduct disrupts hormones in the brain that regulate the female reproductive cycle in mice and also damages cells in the pituitary gland.

Iodoacetic acid, or IAA, is created when an oxidizing disinfectant such as chlorine reacts with the iodide naturally present in water, said study leader Lori Raetzman, a professor of molecular and integrative physiology. The new study’s findings of IAA’s effects on reproductive regulation in the brain complement previous work by study co-author Jodi Flaws, a professor of comparative biosciences, which found that IAA also disrupts function in and causes damage to ovary cells, indicating that the chemical could impact the entire reproductive system.

“We know we need to disinfect water, but the water that’s coming out of our taps isn’t pure – regulators only screen for the things they know about. Water regulatory bodies have not been looking for IAA,” Raetzman said. “This study is contributing to the growing body of evidence that suggests that IAA may impact reproduction, so it might be reasonable to have screening for this too, and to establish a safe level for it.”

Robust approach needed to reduce risk of disease transmission between humans and wild animals

Credit: Pixabay
The threat of disease transmission from conservationists moving wild animals between habitats or back into the wild needs to be urgently assessed to minimize risk. Experts at the University of Birmingham are calling on local and national health authorities and wildlife managers to adopt a robust approach.

In a new paper, published in Frontiers in Veterinary Science, researchers in the University’s College of Life and Environmental Sciences, collaborating with Wildlife Impact and other sector partners, have highlighted the issues using the example of translocated orangutans in Indonesia.

All three species of orangutans in Indonesia are listed as Critically Endangered, and moving animals between habitats is a fairly common practice as demands for agriculture, mining, and other natural resource use puts pressure on the forests they inhabit. Interactions and conflict between humans and orangutans sharing the same habitats also contributes to the complex problems facing these rare species across their range.

During the covid 19 pandemic, the team identified instances of orangutans being released who had been in direct contact or proximity to humans without any protective equipment. In some cases, formerly captive orangutans were released after long periods of contact and potential exposure to human diseases.

The team’s results suggest that there is a potential problem of pathogen transmission between humans and animals which needs to be properly understood and managed.

SARS-CoV-2 infects sustentacular cells in the olfactory epithelium of COVID-19 patients

A lone infected sustentacular cell is surrounded by non-infected cells in the olfactory mucosa of a COVID-19 patient who died four days after diagnosis of the infection. The infected cell has the characteristic shape of a wine glass. The blue color comes from staining with an antibody against the nucleocapsid protein of the virus. The red dots represent staining with an RNAscope probe for a gene that is expressed in sustentacular cells (GPX3). Within the lone infected cell, there are few or no red dots, because infection of a cell with SARS-CoV-2 causes decay of host RNA molecules. The green dots represent staining with an an RNAscope probe for a type of viral RNA molecules that are only present during ongoing viral replication. This lone sustentacular cell was thus serving as a “factory” for replicating viral RNA at the time the postmortem tissue sample was taken.
© MP Research Unit f. Neurogenetics/ Mona Khan

It is now widely known that COVID-19 is associated with the transient or long-term loss of olfaction (the sense of smell) but the mechanisms remain obscure. An unresolved question is whether the olfactory nerve can provide SARS-CoV-2 with a route of entry to the brain. Scientists at the Max Planck Research Unit for Neurogenetics in Frankfurt in collaboration with physicians and scientists at the University Hospitals Leuven (Leuven, Belgium) and a major hospital in Bruges, Belgium, together with scientists at NanoString Technologies Inc. in Seattle, USA, report that SARS-CoV-2 does not appear to infect the sensory neurons of the olfactory epithelium in COVID-19 patients. Moreover, the team failed to find evidence for infection of olfactory bulb neurons. Instead, the sustentacular cells, also known as supporting cells, are the main target cell type for the virus in the olfactory epithelium. Since SARS-CoV2 spares olfactory sensory neurons and olfactory bulb neurons, it does not appear to be a neurotropic virus.

For the brain, context is key to new theory of movement and memory

Photo by lebih dari ini from Pexels
How is it that a chef can control their knife to fillet a fish or peel a grape and can wield a cleaver just as efficiently as a paring knife? Even those of us less proficient in the kitchen learn to skillfully handle an astonishing number of different objects throughout our lives, from shoelaces to tennis rackets.

This ability to continuously acquire new skills, without forgetting or degrading old ones, comes naturally to humans but is a major challenge even for today’s most advanced artificial intelligence systems.

Now, scientists from the University of Cambridge and Columbia University have developed and experimentally verified a new mathematical theory that explains how the human brain achieves this feat. Called the COntextual INference (COIN) model, it suggests that identifying the current context is key to learning how to move our bodies.

The model describes a mechanism in the brain that is constantly trying to figure out the current context. The theory suggests that these continuously changing beliefs about context determine how to use existing memories — and whether to form new ones. The results are reported in the journal Nature.

“Imagine playing tennis with a different racket than usual or switching from tennis to squash,” said co-senior author Dr Daniel Wolpert from Columbia University. “Our theory explores how your brain adjusts to these situations and whether to treat them as distinct contexts.”

According to the COIN model, the brain maintains a repertoire of motor memories, each associated with the context in which it was created, such as playing squash versus tennis. Even for a single swing of the racket, the brain can draw upon many memories, each in proportion to how much the brain believes it is currently in the context in which that memory was created.

Antibody treatment for Covid-19

Dr. Christoph Spinner is an infectiologist and pandemic officer
at the Klinikum rechts der Isar university hospital
of the Technical University of Munich.
Image: argum, MRI
A new treatment could prevent serious illness in case of Covid-19 infections during the pandemic. This would prevent hospitalization of patients and thus ease the burden on the healthcare system. For several months, inpatients at the Klinikum rechts der Isar university hospital of the Technical University of Munich (TUM) have been successfully treated with neutralizing antibodies. This treatment option at the Antibody Center has now been extended to outpatients.

The new form of treatment has proven highly effective against severe Covid-19 illness above all in persons with chronic conditions who do not respond sufficiently to an active vaccination.

“With approval by the European Medicines Agency (EMA) on November 12, the neutralizing antibodies can now be widely used at an early stage of the illness,” said adjunct teaching professor Dr. Christoph Spinner, infectious disease specialist and pandemic officer at Klinikum rechts der Isar, and his colleague, adjunct teaching professor Dr. Jochen Schneider, who heads the new Covid-19 outpatient clinic for monoclonal antibody treatment at the same hospital.

With the current surge in patient numbers, especially in Bavaria, the experts believe that this treatment can benefit many people and should therefore be made widely available as quickly as possible.

“To make that happen, we will be happy to share our skills and experience from a university clinic with colleagues at other hospitals in the fight against the pandemic,” says Dr. Spinner.

Tuesday, November 23, 2021

Compounds from soybeans may improve animal health

The sprouting soybeans, in front, have been inoculated with a pathogen to trigger production of glyceollins, which have antimicrobial properties. Scaling up these lab experiments at the POET Bioproducts Institute may lead to soybeans that are rich in glyceollins being integrated into animal feed to help prevent disease and reduce the need for antibiotics.

Antimicrobial compounds that soybean plants produce when threatened by insects, diseases and even drought may help animals stay healthy, thereby reducing the need for antibiotics.

“When a soybean is attacked by a pathogen, the plant produces phytochemicals called glyceollins as a defense mechanism,” explained assistant professor Bishnu Karki of South Dakota State University’s Department of Biology and Microbiology. Her research group has identified pathogens and lab-scale processes to trigger production of glyceollins and begun assessing soybean varieties to see which produce higher levels of the antimicrobial compounds.

“Animals, such as pigs and poultry, already consume diets high in soybeans and could benefit from the phytochemical’s antimicrobial properties,” Karki said, pointing out scientists are studying the impact of glyceollins on human health, specifically in relation to cancer, inflammation and cardiovascular diseases.

Karki’s research is supported by U.S. Department of Agriculture Hatch Act funding through the South Dakota Agricultural Experiment Station. Two master’s students and several undergraduates have also worked on the project.

Scientists Find SARS CoV-2-Related Coronaviruses in Cambodian Bats from 2010

Rhinolophus shameli Credit: Ben Hayes 

A team of scientists have identified coronaviruses closely related to SARS-CoV-2 from two bats sampled in Cambodia more than a decade ago. The discovery described in the journal Nature Communications, along with the recent detection of the closest ancestors of SARS-CoV-2 known to date in cave-dwelling bats in Laos, indicates that SARS-CoV-2-related viruses that cause COVID-19 have a much wider geographic distribution than previously reported and further supports the hypothesis that the pandemic originated via spillover of a bat-borne virus.

Scientists used metagenomic sequencing to identify the nearly identical viruses in two Shamel’s horseshoe bats (Rhinolophus shameli) originally sampled in 2010. The finding suggests that SARS-CoV-2 related viruses likely circulate via multiple Rhinolophus species.

The authors state that the current understanding of the geographic distribution of the SARS-CoV and SARS-CoV-2 lineages possibly reflects a lack of sampling in Southeast Asia, or at least across the Greater Mekong Subregion, which encompasses Myanmar, Laos, Thailand, Cambodia and Vietnam, as well as the Yunnan and Guanxi provinces of China.

Two-meter COVID-19 rule is ‘arbitrary measurement’ of safety

Credit: University of Cambridge
A team of engineers from the University of Cambridge used computer modeling to quantify how droplets spread when people cough. They found that in the absence of masks, a person with COVID-19 can infect another person at a two-meter distance, even when outdoors.

The team also found that individual coughs vary widely, and that the ‘safe’ distance could have been set at anywhere between one to three or more meters, depending on the risk tolerance of a given public health authority.

The results, published in the journal Physics of Fluids, suggest that social distancing is not an effective mitigation measure on its own, and underline the continued importance of vaccination, ventilation and masks as we head into the winter months in the northern hemisphere.

Despite the focus on hand-washing and surface cleaning in the early days of the pandemic, it’s been clear for nearly two years that COVID-19 spreads through airborne transmission. Infected people can spread the virus through coughing, speaking or even breathing, when they expel larger droplets that eventually settle or smaller aerosols that may float in the air.

“I remember hearing lots about how COVID-19 was spreading via door handles in early 2020, and I thought to myself if that were the case, then the virus must leave an infected person and land on the surface or disperse in the air through fluid mechanical processes,” said Professor Epaminondas Mastorakos from Cambridge’s Department of Engineering, who led the research.

Global warming, not just drought, drives bark beetles to kill more ponderosa pines

Outbreaks of western pine beetles are decimating ponderosa pines
 in California’s Sierra Nevada and across the West.
Credit: Los Alamos National Laboratory 
In California’s Sierra Nevada, western pine beetle infestations amped up by global warming were found to kill 30% more ponderosa pine trees than the beetles do under drought alone. A new supercomputer modeling study hints at the grim prospect of future catastrophic tree die-offs and offers insights for mitigating the combined risk of wildfires and insect outbreaks.

“Forests represent a crucial buffer against warming climate and are often touted as an inexpensive mitigation strategy against climate change,” said Zachary Robbins, a researcher at Los Alamos National Laboratory, graduate student at North Carolina State University, and lead author of the paper on beetles and ponderosa pine tree die-offs. “Our research shows that warming shortens the time between beetle generations, supercharging beetle population growth. That can then spur catastrophic mortality in forest systems during drought in the Sierra Nevada and throughout the Western United States.”

In the recently published study in Global Change Biology, Robbins and his collaborators developed a new modeling framework to assess the risk western pine beetles, or bark beetles, pose in many forest ecosystems under climate change. If the effects of compromised tree defenses (15% to 20%) and increased bark beetle populations (20%) are additive, the team determined that 35% to 40% more ponderosa pines would die from beetle attacks for each degree Celsius of warming.

“Our study is the first to attribute a level of tree mortality to the direct effect of warming on bark beetles, using a model that captures both beetle reproduction and development rates and host stress,” Robbins said. “We found that even slight increases in the number of annual generations of bark beetles due to warming can significantly increase tree mortality during drought.”

Turning a climate problem into a food solution


Like a mirage on the horizon, an innovative process for converting a potent greenhouse gas into a food security solution has been stalled by economic uncertainty. Now, a first-of-its-kind Stanford University analysis evaluates the market potential of the approach, in which bacteria fed captured methane grow into protein-rich fishmeal. The study, published Nov. 22 in Nature Sustainability, finds production costs involving methane captured from certain sources in the U.S. are lower than the market price for conventional fishmeal. It also highlights feasible cost reductions that could make the approach profitable using other methane sources and capable of meeting all global fishmeal demand.

“Industrial sources in the U.S. are emitting a truly staggering amount of methane, which is uneconomical to capture and use with current applications,” said study lead author Sahar El Abbadi, who conducted the research as a graduate student in civil and environmental engineering.

“Our goal is to flip that paradigm, using biotechnology to create a high-value product,” added El Abbadi, who is now a lecturer in the Civic, Liberal and Global Education program at Stanford.

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