Evolution of tree roots may have driven mass extinctions

Scientists collect rock samples on Ymer Island in eastern Greenland, one of several sites whose analysis provided insight into the chemical makeup of lake beds in the Devonian Period.
Photo Credit: John Marshall, University of Southampton

The evolution of tree roots may have triggered a series of mass extinctions that rocked the Earth’s oceans during the Devonian Period over 300 million years ago, according to a study led by scientists at IUPUI, along with colleagues in the United Kingdom.

Evidence for this new view of a remarkably volatile period in Earth’s pre-history is reported in the Geological Society of America Bulletin, one of the oldest and most respected publications in the field of geology. The study was led by Gabriel Filippelli, Chancellor’s Professor of Earth Sciences in the School of Science at IUPUI, and Matthew Smart, a Ph.D. student in his lab at the time of the study.

“Our analysis shows that the evolution of tree roots likely flooded past oceans with excess nutrients, causing massive algae growth,” Filippelli said. “These rapid and destructive algae blooms would have depleted most of the oceans’ oxygen, triggering catastrophic mass extinction events.”

Previously unseen processes reveal path to better rechargeable battery performance

Materials science and engineering postdoctoral researcher Wenxiang Chen is the first author of a new study that applies imaging techniques common in ceramics and metallurgy to rechargeable ion battery research. 
Photo by Fred Zwicky

To design better rechargeable ion batteries, engineers and chemists from the University of Illinois Urbana-Champaign collaborated to combine a powerful new electron microscopy technique and data mining to visually pinpoint areas of chemical and physical alteration within ion batteries.

A study led by materials science and engineering professors Qian Chen and Jian-Min Zuo is the first to map out altered domains inside rechargeable ion batteries at the nanoscale – a 10-fold or more increase in resolution over current X-ray and optical methods.

The findings are published in the journal Nature Materials.

The team said previous efforts to understand the working and failure mechanisms of battery materials have primarily focused on the chemical effect of recharging cycles, namely the changes in the chemical composition of the battery electrodes.

A new electron microscopy technique, called four-dimensional scanning transmission electron microscopy, allows the team to use a highly focused probe to collect images of the inner workings of batteries.

A mysterious outbreak of bone-eating tb resembled an ancestral form

Tuberculosis is usually encountered as a disease of the lungs, but in 2 percent of cases in the U.S. it can also be found in the bones. The 9,000-year-old skeletons of some Egyptian mummies show signs of having tuberculosis infection in their bones, a painful condition that leaves the bones looking like they’ve been gnawed.

So, it was a weird puzzle when Duke physician Jason Stout M.D. encountered a Wake County TB outbreak in the mid-2000s in which the infection had spread beyond the lungs in six people. “Four out of six were in the bone,” Stout said. “That’s way more than 2 percent.”

The index case, the first person in Raleigh to have this strain of the disease, apparently contracted the bacterium in Vietnam, but he wasn’t feeling very sick and had been working around 400 people in his workplace.

“So, it was prolonged exposure in a workplace,” said Stout, a Duke professor of medicine who tracked down and identified seven subsequent infections through contact tracing and health department records.

All eight people were treated with antibiotics and other co-workers received preventative care and then the strange outbreak went away. But the mystery was never really solved. “I’m an epidemiologist and clinical trial specialist and I was left scratching my head,” Stout said.

Workplace cafeteria study finds no evidence that physical activity calorie-equivalent labeling changes food purchasing

PACE labels alongside menus 
Credit: University of Cambridge

More than three in five UK adults are overweight or obese, increasing their risk of diseases such as type 2 diabetes and cancer. A major factor that contributes to this is excess energy intake – in other words, eating too many calories. Measures that can help reduce energy intake could help tackle the obesity problem.

In the UK, adults eat as many as a third of their meals out of home, including in workplace cafeterias, and these meals are often much higher in calories than meals eaten at home. Since April 2022 calorie labelling is now required on food and drink served out of the home in businesses employing 250 or more people. While many people welcome this information, evidence for its effectiveness in reducing calories purchased or consumed is limited in quantity and quality. For example, two previous studies conducted by the authors in nine worksite cafeterias found no evidence for an effect of simple calorie labelling (kcal) on calories purchased.

Another option is to show the amount of exercise required to burn off these calories – so-called PACE (physical activity calorie-equivalent) labels – for example, a 1014kcal ‘large battered haddock’ portion would take upwards of five hours walking (278 minutes) to burn off. A recent systematic review – a type of study that brings together existing evidence – concluded that PACE labels may reduce energy selected from menus and decrease the energy consumed when compared with simple calorie labels or no labels, but only one of the 15 studies reviewed was in a ‘real world’ setting.

How Pathogens Hijack Immune System to Cause Vaccine-Enhanced Disease

Associate Professor Steven Szczepanek (standing, left) with graduate students Tyler Gavitt (seated) and Arlind Mara (standing, right).
Photo Credit: Jason Sheldon/UConn

Researchers in the College of Agriculture, Health and Natural Resources are working to unlock a decades-long mystery that has hampered development of a walking pneumonia vaccine.

Associate Professor Steven Szczepanek and Professor Steven Geary from the Department of Pathobiology and Veterinary Science, along with former graduate students Tyler Gavitt and Arland Mara, published findings that help explain how Mycoplasma pneumoniae (Mp) hijacks our immune system following vaccination.

They shared their findings in two recent publications in Nature journal npj Vaccines.

Mp is a common pathogen that causes walking pneumonia. While this respiratory infection is not typically severe, it is a common co-pathogen with illnesses that spread in the same way, like the flu or COVID-19, which can cause more severe illnesses, especially in older or immunocompromised adults.

In the 1960s, scientists began working to develop an Mp vaccine. They killed the bacteria and injected it into human subjects, thinking it would provide protection from actual infection. But that’s not what happened.

Screening for stroke risk can save lives and money

Emma Svennberg, specialist in cardiology. Screening involves placing the thumbs onto a hand-held ECG machine.
Photo Credit: Johan Adelgren

Atrial fibrillation is the greatest risk factor for stroke. Screening to detect atrial fibrillation in older people would not only increase the chance of preventing stroke, it would also save money for the healthcare system and society. This is the conclusion from research conducted at Linköping University and Karolinska Institutet.

“The greatest benefit from screening is that you receive information that could be used to reduce an individual’s risk of stroke and thus may help them live longer with a good quality of life,” says Emma Svennberg, specialist in cardiology at Karolinska University Hospital, and affiliated researcher at Karolinska Institutet.

A systematic screening program for atrial fibrillation is not in use anywhere in the world. The researchers who conducted the present study, published in European Journal of Heart, have calculated the cost effectiveness of screening for atrial fibrillation in people aged 75-76 years, and conclude that there are strong reasons for introducing such a program.

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.