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Tuesday, March 22, 2022

New study defines spread of SARS-CoV-2 in white-tailed deer

White-Tailed Deer
Credit: Heidi-Ann Fourkiller / SFLORG

North American white-tailed deer – shown in 2021 surveys of five states to have SARS-CoV-2 infection rates of up to 40% – shed and transmit the virus for up to five days once infected, according to a new study.

“It’s a relatively short window of time in which the infected animals are shedding and are able to transmit the virus,” said Dr. Diego Diel, associate professor in the Department of Population Medicine and Diagnostic Sciences and director of the Virology Laboratory at the College of Veterinary Medicine’s Animal Health Diagnostic Center. “However, the virus is very efficient at transmitting to white-tailed-deer entering contact with infected animals.”

The study, “From Deer-to-Deer: SARS-CoV-2 is Efficiently Transmitted and Presents Broad Tissue Tropism and Replication Sites in White-Tailed Deer,” which published online on March 21 in PLOS Pathogens, also identified that the virus develops and replicates in the deer’s respiratory tract, lymphoid tissues – including tonsils and several lymph nodes – and in central nervous system tissues.

“Virus replication in the upper respiratory tract – especially the nasal turbinates [nose structures] - is comparable with what is observed in humans and in other animals that are susceptible to the infection,” Diel said, “and I think that’s probably one of the reasons why the virus transmits so efficiently.” As with humans, the virus spreads between deer through nasal and oral secretions and aerosols.

Study ties present-day Native American tribe to ancestors in San Francisco Bay Area

U. of I. anthropology professor Ripan Malhi and his colleagues found genomic evidence linking present-day members of the Muwekma Ohlone Tribe in the San Francisco Bay Area with individuals who lived in the region several hundred to 2,000 years ago. 
Credit/Photo by L. Brian Stauffer

A genomic study of Native peoples in the San Francisco Bay Area finds that eight present-day members of the Muwekma Ohlone Tribe share ancestry with 12 individuals who lived in the region several hundred to 2,000 years ago.

Reported in the Proceedings of the National Academy of Sciences, the study challenges the notion that the Ohlone migrated to the area between A.D. 500-1,000, said Ripan Malhi, a professor of anthropology at the University of Illinois Urbana-Champaign, who led the research with Stanford University population genetics and society professor Noah Rosenberg in collaboration with a team of other scientists and members of the Muwekma Ohlone Tribe. The Muwekma Ohlone Tribal Council requested, contributed to and oversaw the study.

Previous studies of artifacts and language patterns suggested that the Ohlone were relative newcomers to the region. But the genomic research found a deep signal of continuity between the ancient population and the new one, the team reported.

Our sleep shows how risk-seeking we are

Test person sleeping in a familiar environment. The researchers derive the personal sleep profile from the measurement of the brain waves.
© Courtesy of Social Neuro Lab / UniBE

Each person has their own individual sleep profile which can be identified by electrical brain activity during sleep. Researchers at the University of Bern have now demonstrated that brain waves during periods of deep sleep in a specific area of the brain can be used to determine the extent of an individual’s propensity for risk during their everyday life.

Each day, we make countless decisions in which we take different risks – in road traffic, when buying shares or in our sexual behavior, for example. The propensity for risk varies from one individual to the next. Researchers led by Daria Knoch, Professor of Social Neuroscience at the University of Bern, have demonstrated that clues in the brain concerning an individual’s propensity for risk can be gathered as they sleep: “The fewer slow waves an individual has over their right prefrontal cortex during deep sleep, the greater their propensity for risk. Among other functions, this region of the brain is important to control one’s own impulses,” explains the neuroscientist. The results have recently been published in the journal “NeuroImage.”

Monday, March 21, 2022

How the Chagas pathogen changes the intestinal microbiota of predatory bugs

The predatory bug Rhodnius prolixus is one of the main vectors of Chagas disease in the north of South America and in Central America.
Photo: Dr Erwin Huebner, University of Manitoba, Winnipeg, Canada/ Wikimedia Commons
In Central and South America, predatory blood-sucking bugs transmit the causative agent of the widely prevalent Chagas disease. As the disease can induce severe symptoms and to date there is no vaccine against the Trypanosoma parasites, the main approach at present is to control the bug using insecticides. A German-Brazilian research team has now studied how trypanosomes change the bug's intestinal microbiota. The long-term goal: to change the bacterial community in the predatory bug's intestine in such a way that it can defend itself against the trypanosomes.

According to estimates by the World Health Organization (WHO), between six and seven million people worldwide, predominantly in Central and South America, are infected with the Trypanosoma cruzi species of trypanosome. This single-celled (protozoan) parasite causes Chagas disease (American trypanosomiasis), which in the acute phase is inconspicuous: only in every third case does the infected person develop any symptoms at all, which can then be unspecific, such as fever, hives and swollen lymph nodes. However, the parasites remain in the body, and many years later chronic Chagas disease can become life-threatening, with pathological enlargement of the heart and progressive paralysis of the gastrointestinal tract.

New experiment could confirm the fifth element

Dr Melvin Vopson
An experiment which could confirm the fifth state of matter in the universe - and change physics as we know it - has been published in a new paper published in AIP Advances from the University of Portsmouth.

Physicist Dr Melvin Vopson has already published research suggesting that information has mass and that all elementary particles, the smallest known building blocks of the universe, store information about themselves, similar to the way humans have DNA.

Now he has designed an experiment - which if proved correct - means he will have discovered that information is the fifth form of matter, alongside solid, liquid, gas and plasma.

Dr Vopson said: “This would be a eureka moment because it would change physics as we know it and expand our understanding of the universe. But it wouldn’t conflict with any of the existing laws of physics.

“It doesn’t contradict quantum mechanics, electrodynamics, thermodynamics or classical mechanics. All it does is complement physics with something new and incredibly exciting.”

Dr Vopson’s previous research suggests that information is the fundamental building block of the universe and has physical mass.

He even claims that information could be the elusive dark matter that makes up almost a third of the universe.

He said: “If we assume that information is physical and has mass, and that elementary particles have a DNA of information about themselves, how can we prove it? My latest paper is about putting these theories to the test so they can be taken seriously by the scientific community.”

New insight into the possible origins of life

RNA molecules were incubated in water-in-oil droplets at 37 degrees Celsius for 5 hours. The solution was then diluted to one-fifth the concentration using new droplets containing RNA-free nutrients, and stirred vigorously. When this process was repeated multiple times, mutations occurred.
Source/Credit: modified from Mizuuchi 2022

Researchers at the University of Tokyo have for the first time been able to create an RNA molecule that replicates, diversifies and develops complexity, following Darwinian evolution. This has provided the first empirical evidence that simple biological molecules can lead to the emergence of complex lifelike systems.

Life has many big questions, not least being where did we come from? Maybe you’ve seen the T-shirts with pictures going from ape to human (to tired office worker). But how about from simple molecule to complex cell to ape? For several decades, one hypothesis has been that RNA molecules (which are vital for cell functions) existed on primitive Earth, possibly with proteins and other biological molecules. Then around 4 billion years ago, they started to self-replicate and develop from a simple single molecule into diverse complex molecules. This step-by-step change possibly eventually led to the emergence of life as we know it — a beautiful array of animals, plants, and everything in between.

Although there have been many discussions about this theory, it has been difficult to physically create such RNA replication systems. However, in a study published in Nature Communications, Project Assistant Professor Ryo Mizuuchi and Professor Norikazu Ichihashi at the Graduate School of Arts and Sciences at the University of Tokyo, and their team, explain how they carried out a long-term RNA replication experiment in which they witnessed the transition from a chemical system towards biological complexity.

Monarch butterflies are increasingly plagued by parasites, study shows

A cluster of monarch butterflies overwintering on a tree in Mexico
Credit: Jaap de Roode 

Monarch butterflies, one of the most iconic insects of North America, are increasingly plagued by a debilitating parasite, a major new analysis shows. The Journal of Animal Ecology published the findings, led by scientists at Emory University.

The analysis drew from 50 years of data on the infection rate of wild monarch butterflies by the protozoan Ophryocystis elektrosirrha, or O.E. The results showed that the O.E. infection rate increased from less than one percent of the eastern monarch population in 1968 to as much as 10 percent today.

“We’re seeing a significant change in a wildlife population with a parasitism rate steadily rising from almost non-existent to as high as 10 percent,” says Ania Majewska, first author of the paper and a post-doctoral fellow in Emory’s Department of Biology. “It’s a signal that something is not right in the environment and that we need to pay attention.”

The O.E. parasite invades the gut of the monarch caterpillars. If the adult butterfly leaves the pupal stage with a severe parasitic infection, it begins oozing fluids from its body and dies. Even if the butterflies survive, as in case of a lighter infection, they do not fly well or live as long as uninfected ones.

Astronomers Closer to Unlocking Origin of Mysterious Fast Radio Bursts

Artist's conception of fast radio burst reaching Earth.
Credit: Jingchuan Yu, Beijing Planetarium

Nearly 15 years after the discovery of fast radio bursts (FRBs), the origin of the millisecond-long, deep-space cosmic explosions remain a mystery.

That may soon change, thanks to the work of an international team of scientists – including UNLV astrophysicist Bing Zhang – which tracked hundreds of the bursts from five different sources and found clues in FRB polarization patterns that may reveal their origin. The team’s findings were reported in the journal Science.

FRBs produce electromagnetic radio waves, which are essentially oscillations of electric and magnetic fields in space and time. The direction of the oscillating electric field is described as the direction of polarization. By analyzing the frequency of polarization in FRBs observed from various sources, scientists revealed similarities in repeating FRBs that point to a complex environment near the source of the bursts.

“This is a major step towards understanding the physical origin of FRBs,” said Zhang, a UNLV distinguished professor of astrophysics who coauthored the paper and contributed to the theoretical interpretation of the phenomena.

Ancient ancestors evolved to be strong and snappy, study finds

Dunkleosteus - one of the animals involved in the study.
Credit: Nobu Tamura

Researchers, led by the University of Bristol, have shown that the earliest jaws in the fossil record were caught in a trade-off between maximizing their strength and their speed.

Almost all vertebrates are jawed vertebrates, including humans, first evolving more than 400 million years ago and distinguished by their teeth-bearing jaws. Humans owe their evolutionary success to the evolution of jaws, which allowed animals to process a wider variety of foods.

Jaws evolved from the gill arches, a series of structures in fish that support their gills. A new study, published in the journal Science Advances, explores how a breathing structure came to be a biting structure. To do this, researchers based at Bristol’s School of Earth Sciences collected data on the shapes of fossil jaws during their early evolution and mathematical models to characterize them. These models allowed the team to extrapolate a wide range of theoretical jaw shapes that could have been explored by the first evolving jaws. These theoretical jaws were tested for their strength - how likely they were to break during a bite, and their speed - how efficiently they could be opened and closed. These two functions are in a trade-off – meaning that increasing strength usually means decreasing speed or vice versa.

Effectiveness of antibiotics significantly reduced when multiple bugs present

In the study, published today in The ISME Journal, researchers say that even a low level of one type of microbe in the airways can have a profound effect on the way other microbes respond to antibiotics.

The results highlight the need to consider the interaction between different species of microbe when treating infections with antibiotics - and to adjust dosage accordingly.

“People with chronic infections often have co-infection with several pathogens, but the problem is we don’t take that into account in deciding how much of a particular antibiotic to treat them with. Our results might help explain why, in these people, the antibiotics just don’t work as well as they should,” said Thomas O’Brien, who carried out the research for his PhD in the University of Cambridge’s Department of Biochemistry and is joint first author of the paper.

Chronic bacterial infections such as those in the human airways are very difficult to cure using antibiotics. Although these types of infection are often associated with a single pathogenic species, the infection site is frequently co-colonized by a number of other microbes, most of which are not usually pathogenic in their own right.

Treatment options usually revolve around targeting the pathogen, and take little account of the co-habiting species. However, these treatments often fail to resolve the infection. Until now scientists have had little insight into why this is.

To get their results the team developed a simplified model of the human airways, containing artificial sputum (phlegm) designed to chemically resemble the real phlegm coughed up during an infection, packed with bacteria.

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