New insights on bacteria that causes food poisoning

The pathogenic genes of Providencia rustigianii can be transferred to Enterobacteriaceae as well.
   Illustration Credit: Shinji Yamasaki, Osaka Metropolitan University

Latest research reveals the properties of a type of food poisoning bacteria, and paves way for establishment of preventive methods.

The transfer of pathogenic genes between not only same bacterial species but also different species

Recently, Providencia spp. which have been detected in patients with gastroenteritis, and similar to enterohemorrhagic Escherichia coli. O157 and Salmonella spp., have been attracting attention as causative agents of food poisoning. For children with low immunity, food poisoning can be lethal as it causes severe symptoms such as diarrhea and dehydration, so clarifying the source of infection and pathogenic factors of Providencia spp., and establishing preventive methods are urgent issues worldwide.

Researchers created a new and improved way to view the mechanics of life

RESORT. A diagram to show the basic overview of the system. Firstly, the sample is labeled with the photoswitchable Raman probe. It’s then irradiated with two-color infrared laser pulses, ultraviolet light, and a special donut-shaped beam of visible light to constrain the area where Raman scattering can occur. As a result, the probe can be detected at a very precise point for high spatial resolution images.
Illustration Credit: ©2023 Ozeki et al.
(CC BY 2.0)

There are various ways to image biological samples on a microscopic level, and each has its own pros and cons. For the first time, a team of researchers, including those from the University of Tokyo, has combined aspects from two of the leading imaging techniques to craft a new method of imaging and analyzing biological samples. Its concept, known as RESORT, paves the way to observe living systems in unprecedented detail.

For as long as humanity has been able to manipulate glass, we have used optical devices to peer at the microscopic world in ever increasing detail. The more we can see, the more we can understand, hence the pressure to improve upon tools we use to explore the world around, and inside, us. Contemporary microscopic imaging techniques go far beyond what traditional microscopes can offer. Two leading technologies are super-resolution fluorescence imaging, which offers good spatial resolution, and vibrational imaging, which compromises spatial resolution but can use a broad range of colors to help label many kinds of constituents in cells.

Pregnancy hormone repairs myelin damage in MS mouse model

Photo Credit: Yassine Khalfalli

Treating a mouse model of multiple sclerosis with the pregnancy hormone estriol reversed the breakdown of myelin in the brain’s cortex, a key region affected in multiple sclerosis, according to a new UCLA Health study.

In multiple sclerosis, inflammation spurs the immune system to strip away the protective myelin coating around nerve fibers in the brain’s cortex, hampering electrical signals sent and received by the brain. Atrophy of the cortex in MS patients is associated with permanent worsening of disability, such as cognitive decline, visual impairment, weakness and sensory loss.

No currently available treatments for MS can repair damage to myelin. Instead, these treatments target inflammation to reduce symptom flare-ups and new nerve tissue scarring. Previous UCLA-led research found that estriol, a type of estrogen hormone produced in pregnancy, reduced brain atrophy and improved cognitive function in MS patients.

In the new study, researchers treated a mouse model of MS with estriol and found that it prevented brain atrophy and induced remyelination in the cortex, indicating that the treatment can repair damage caused by MS, rather than just slow the destruction of myelin.

Altered gut bacteria may be early sign of Alzheimer’s disease

 

Alzheimer’s disease causes changes to the brain that begin two decades or more before symptoms appear. A study by researchers at Washington University School of Medicine in St. Louis reveals that the bacteria that live in the gut also change before Alzheimer’s symptoms arise, a discovery that could lead to diagnostics or treatments for Alzheimer’s disease that target the gut microbiome.
Image Credit: Gerd Altmann

People in the earliest stage of Alzheimer’s disease — after brain changes have begun but before cognitive symptoms become apparent — harbor an assortment of bacteria in their intestines that differs from the gut bacteria of healthy people, according to a study by researchers at Washington University School of Medicine in St. Louis.

The findings, published June 14 in Science Translational Medicine, open up the possibility of analyzing the gut bacterial community to identify people at higher risk of developing dementia, and of designing microbiome-altering preventive treatments to stave off cognitive decline.

“We don’t yet know whether the gut is influencing the brain or the brain is influencing the gut, but this association is valuable to know in either case,” said co-corresponding author Gautam Dantas, PhD, the Conan Professor of Laboratory and Genomic Medicine. “It could be that the changes in the gut microbiome are just a readout of pathological changes in the brain. The other alternative is that the gut microbiome is contributing to Alzheimer’s disease, in which case altering the gut microbiome with probiotics or fecal transfers might help change the course of the disease.”

Illusions are in the eye, not the mind

The bar in the middle is all one grey level, but it appears lighter on the left and darker on the right due to the background.
Image Credit Jolyon Troscianko

Numerous visual illusions are caused by limits in the way our eyes and visual neurons work – rather than more complex psychological processes, new research shows.

Researchers examined illusions in which an object’s surroundings affect the way we see its color or pattern.

Scientists and philosophers have long debated whether these illusions are caused by neural processing in the eye and low-level visual centers in the brain, or involve higher-level mental processes such as context and prior knowledge.

In the new study Dr Jolyon Troscianko, from the University of Exeter, co-developed a model that suggests simple limits to neural responses – not deeper psychological processes – explain these illusions.

“Our eyes send messages to the brain by making neurons fire faster or slower,” said Dr Troscianko, from the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.  

Navigating underground with cosmic-ray muons

Navigating inside with muons. The red line in this image represents the path the “navigatee” walked, while the white line with dots shows the path recorded by MuWNS.
Illustration Credit: ©2023 Hiroyuki K.M. Tanaka

Superfast, subatomic-sized particles called muons have been used to wirelessly navigate underground in a reportedly world first. By using muon-detecting ground stations synchronized with an underground muon-detecting receiver, researchers at the University of Tokyo were able to calculate the receiver’s position in the basement of a six-story building. As GPS cannot penetrate rock or water, this new technology could be used in future search and rescue efforts, to monitor undersea volcanoes, and guide autonomous vehicles underground and underwater.

GPS, the global positioning system, is a well-established navigation tool and offers an extensive list of positive applications, from safer air travel to real-time location mapping. However, it has some limitations. GPS signals are weaker at higher latitudes and can be jammed or spoofed (where a counterfeit signal replaces an authentic one). Signals can also be reflected off surfaces like walls, interfered with by trees, and can’t pass through buildings, rock or water.

Tethering of Shattered Chromosomal Fragments Paves Way for New Cancer Therapies

Like pieces of broken safety glass, shattered chromosomal fragments are tethered together during cell division, allowing them to be reassembled into a rearranged chromosome that’s prone to cancerous mutations.
Photo Credit: Marzena P.

Healthy cells work hard to maintain the integrity of our DNA, but occasionally, a chromosome can get separated from the others and break apart during cell division. The tiny fragments of DNA then get reassembled in random order in the new cell, sometimes producing cancerous gene mutations. 

This chromosomal shattering and rearranging is called “chromothripsis” and occurs in the majority of human cancers, especially cancers of the bones, brain and fatty tissue. Chromothripsis was first described just over a decade ago, but scientists did not understand how the floating pieces of DNA were able to be put back together. 

In a study published in Nature, researchers at University of California San Diego have answered this question, discovering that the shattered DNA fragments are actually tethered together. This allows them to travel as one during cell division and be re-encapsulated by one of the new daughter cells, where they are reassembled in a different order.

UD study evaluates how climate shocks impact the planted and harvested areas for crops

Dongyang Wei (left), a doctoral candidate in the Department of Geography and Spatial Sciences, and Kyle Davis, assistant professor in the Department of Geography and Spatial Sciences and the Department of Plant and Soil Sciences, as well as a resident faculty member with UD’s Data Science Institute, led a new study that focused on crop production shocks and how they are affected by variations in planted and harvested areas.
Photo Credit: Evan Krape

As the world faces more climate variability and extremes in the face of global warming, sudden environmental changes add an extra layer of stress to food production in the United States and around the world. It is critical, then, to figure out how the areas in which crops are planted and harvested respond to these stressors, which can bring on ‘shocks’ in production — or, put differently, sudden and statistically significant crop declines. 

These production shocks are a big concern in terms of food stability and many crops in the United States — such as corn, cotton, soybeans and wheat — are all experiencing more frequent production reductions as a result of these shocks.

A new study published in the scientific journal Nature Sustainability led by the University of Delaware’s Dongyang Wei looked at these production shocks and, specifically, how they are affected by variations in planted and harvested areas. 

New study reveals strong connection between heart and brain health

A growing amount of evidence points to interactions between heart health and brain health.

Cardiovascular diseases serve as a crucial backdrop for brain diseases like stroke, dementia, cerebral small vessel disease and cognitive impairment. Studies have shown, for example, that atrial fibrillation, even in stroke-free individuals, is associated with an increased incidence of dementia and silent cerebral damage. Heart failure has been linked to cognitive impairment and dementia due to reduced cerebral blood flow caused by a failing heart. Conversely, mental disorders and negative psychological factors may contribute to the onset and progression of cardiovascular diseases. Individuals with conditions such as schizophrenia, bipolar disorder, epilepsy or depression are more prone to cardiovascular diseases.

Despite this growing knowledge, previous studies on heart-brain interactions and associated risk factors have been limited in scope, focusing on specific diseases or utilizing small sample sizes. Consequently, the overall understanding of the structural and functional links between the heart and brain remains incomplete.

A new study conducted by researchers from UNC-Chapel Hill, the University of Pennsylvania and Purdue University leverages large magnetic resonance imaging (MRI) data to shed light on the close relationship between cardiovascular diseases and brain diseases such as stroke, dementia and cognitive impairment, unraveling the underlying genetic signatures and inter-organ connections between the heart and brain.

This salty gel could harvest water from desert air

MIT engineers have synthesized a superabsorbent material that can soak up a record amount of moisture from the air, even in desert-like conditions. Pictured are the hydrogel discs swollen in water.
 Photo Credit: Gustav Graeber and Carlos D. Díaz-Marín

MIT engineers have synthesized a superabsorbent material that can soak up a record amount of moisture from the air, even in desert-like conditions.

As the material absorbs water vapor, it can swell to make room for more moisture. Even in very dry conditions, with 30 percent relative humidity, the material can pull vapor from the air and hold in the moisture without leaking. The water could then be heated and condensed, then collected as ultrapure water.

The transparent, rubbery material is made from hydrogel, a naturally absorbent material that is also used in disposable diapers. The team enhanced the hydrogel’s absorbency by infusing it with lithium chloride — a type of salt that is known to be a powerful dessicant.

The researchers found they could infuse the hydrogel with more salt than was possible in previous studies. As a result, they observed that the salt-loaded gel absorbed and retained an unprecedented amount of moisture, across a range of humidity levels, including very dry conditions that have limited other material designs.