. Scientific Frontline

Tuesday, February 27, 2024

Modern hydropower plants also cause massive damage to ecology

Water samples collected by TUM researchers
Photo Credit: Lehrstuhl für Aquatische Systembiologie / TUM

Even modern and supposedly gentler hydropower plants cause considerable damage to river ecosystems. This is shown by a study by Prof. Jürgen Geist from the Chair of Aquatic Systems Biology at the TUM School of Life Sciences published in the Journal of Applied Ecology. Geist and his team investigated the changes in the complex biocoenoses in rivers at five locations in Bavaria before and after the installation of hydropower plants. They looked not only at fish but also at microorganisms, aquatic plants, and algae growth.

Significant differences in living conditions were observed at all locations, emphasizes Geist. This applies to the situation upstream and downstream of the power plants as well as before and after installation. "Contrary to what was hoped for and predicted by the operators, the new types of power plant have not improved the habitat conditions for current-loving species," the biologist states. In particular, retrofitting existing weirs in conjunction with further damming would have negative effects.

"When planning future plants, in addition to the question of the sometimes-considerable damage to fish when passing through hydropower plants, the previously neglected effects on the habitat and the food web must also be taken into account. This is about the ecological continuity and connection of different river sections as an important criterion for healthy river systems," said Geist. The requirements are defined in the EU Water Framework Directive.

Immune system meets cancer: Checkpoint identified to fight solid tumor

Immunofluorescence image of the expression of PHGDH (red) and CD3 T cells (green) in cryosectioned AE17 mesothelioma.
Image Credit: Zhengnan Cai

Checkpoint PHDGH in tumor-associated macrophages influences immune response and tumor growth

A study by a scientific team from the University of Vienna and the MedUni Vienna, recently published in the top-class journal Cellular & Molecular Immunology, has a promising result from tumor research: The enzyme phosphoglycerate dehydrogenase (PHDGH) acts as a metabolic checkpoint in the function of tumor-associated macrophages (TAMs) and thus on tumor growth. Targeting PHGDH to modulate the cancer-fighting immune system could be a new starting point in cancer treatment and improve the effectiveness of clinical immunotherapies.

Our immune system constantly fights emerging cancer cells that arise from mutations. This process is controlled, among other things, by different types of macrophages. Tumor-associated macrophages (TAMs) are among the most abundant immune cells in the tumor microenvironment. They come from tissue-resident immune cells circulating in the blood that penetrate the tumor and differentiate there in response to various messenger substances (cytokines) and growth factors. In most solid tumors, TAMs are paradoxically considered to be tumor-promoting ("protumorigenic") overall: they promote tumor growth and metastasis by suppressing the immune response, promoting the vascular supply to the tumor and also increasing resistance to drug therapies – i.e. they generally correlate with a poor prognosis for the affected patients. Previous attempts to influence TAMs proved unsatisfactory because many patients had only a limited response to these therapeutic approaches. This underlines the urgency of finding new active ingredients and strategies.

Monday, February 26, 2024

Gut-brain communication turned on its axis

How the gut communicates with the brain
Image Credit: Copilot AI

The mechanisms by which antidepressants and other emotion-focused medications work could be reconsidered due to an important new breakthrough in the understanding of how the gut communicates with the brain.

New research led by Flinders University has uncovered major developments in understanding how the gut communicates with the brain, which could have a profound impact on the make-up and use of medications such as antidepressants.

“The gut-brain axis consists of complex bidirectional neural communication pathway between the brain and the gut, which links emotional and cognitive centers of the brain,” says Professor Nick Spencer from the College of Medicine and Public Health.

“As part of the gut-brain axis, vagal sensory nerves relay a variety of signals from the gut to the brain that play an important role in mental health and wellbeing.

“The mechanisms by which vagal sensory nerve endings in the gut wall are activated has been a major mystery but remains of great interest to medical science and potential treatments for mental health and wellbeing.”

Human stem cells coaxed to mimic the very early central nervous system

Jianping Fu, Ph.D., Professor of Mechanical Engineering at the University of Michigan and the corresponding author of the paper being published at Nature discusses his team’s work in their lab with Jeyoon Bok, Ph.D. candidate at the Department of Mechanical Engineering.
Photo Credit: Marcin Szczepanski, Michigan Engineering

The first stem cell culture method that produces a full model of the early stages of the human central nervous system has been developed by a team of engineers and biologists at the University of Michigan, the Weizmann Institute of Science, and the University of Pennsylvania.

“Models like this will open doors for fundamental research to understand early development of the human central nervous system and how it could go wrong in different disorders,” said Jianping Fu, U-M professor of mechanical engineering and corresponding author of the study in Nature.

The system is an example of a 3D human organoid—stem cell cultures that reflect key structural and functional properties of human organ systems but are partial or otherwise imperfect copies.

“We try to understand not only the basic biology of human brain development, but also diseases—why we have brain-related diseases, their pathology, and how we can come up with effective strategies to treat them,” said Guo-Li Ming, who along with Hongjun Song, both Perelman Professors of Neuroscience at UPenn and co-authors of the study, developed protocols for growing and guiding the cells and characterized the structural and cellular characteristics of the model.

New study uncovers the importance of deepwater ecosystems for endangered species

Hawksbills typically forage on coral reefs where their diet is predominantly sponges.
Photo Credit: Jeanne A Mortimer

Using tracking data, a new study has revealed for the first time that hawksbill turtles feed at reef sites much deeper than previously thought.

Critically endangered hawksbill turtles are found in every ocean and are the most tropical of sea turtles. Adult hawksbills have long been considered to have a close association with shallow (less than 15 meters depth) seas where coral reefs thrive.

Young hawksbills drift in currents during their open water phase of their development before they move to seabed habitats. Hawksbills are usually seen foraging in coral reefs where their diet is predominantly sponges.

To study their feeding habits in more detail, researchers at Swansea, Florida and Deakin universities used high-accuracy GPS satellite tags to track 22 adult female hawksbills from their nesting site on Diego Garcia in the Chagos archipelago in the Indian Ocean to their foraging grounds.

Scientists develop biocompatible fluorescent spray that detects fingerprints in ten seconds

The researchers have made two different colored sprays, which detect fingerprints on a range of different surfaces.
Image Credit: Courtesy of University of Bath

Scientists have developed a water soluble, non-toxic fluorescent spray that makes fingerprints visible in just a few seconds, making forensic investigations safer, easier and quicker.

Latent fingerprints (LFPs) are invisible prints formed by sweat or oil left on an object after it’s been touched.

Traditional forensic methods for detecting fingerprints either use toxic powders that can harm DNA evidence, or environmentally damaging petrochemical solvents.

The new dye spray, developed by scientists at the Shanghai Normal University (China) and the University of Bath (UK), is water soluble, exhibits low toxicity and enables rapid visualization of fingerprints at the crime scene.

They have created two different colored dyes – called LFP-Yellow and LFP-Red – which bind selectively with the negatively-charged molecules found in fingerprints, locking the dye molecules in place and emitting a fluorescent glow that can be seen under blue light.

Vaping can increase susceptibility to infection by SARS-CoV-2

UC Riverside study urges e-cigarette users to be cautious about vaping in the era of COVID-19
Photo Credit: Karl Edwards

Vapers are susceptible to infection by SARS-CoV-2, the virus that spreads COVID-19 and continues to infect people around the world, a University of California, Riverside, study has found.

The liquid used in electronic cigarettes, called e-liquid, typically contains nicotine, propylene glycol, vegetable glycerin, and flavor chemicals. The researchers found propylene glycol/vegetable glycerin alone or along with nicotine enhanced COVID-19 infection through different mechanisms.  

The researchers also found that the addition of benzoic acid to e-liquids prevents the infection caused by propylene glycol, vegetable glycerin, and nicotine. 

“Users who vape aerosols produced from propylene glycol/vegetable glycerin alone or e-liquids with a neutral to basic pH are more likely to be infected by the virus, while users who vape aerosols made from e-liquids with benzoic acid — an acidic pH — will have the same viral susceptibility as individuals who do not vape,” said Rattapol Phandthong, a postdoctoral researcher in the Department of Molecular, Cell and Systems Biology and the research paper’s first author.

The researchers obtained airway stem cells from human donors to produce a 3D tissue model of human bronchial epithelium. They then exposed the tissues to JUUL and BLU electronic cigarette aerosols to study the effect on SARS-CoV-2 infection. They found all tissues showed an increase in the amount of ACE2, a host cell receptor for the SARS-CoV-2 virus. Further, TMPRSS2, an enzyme essential for the virus to infect cells, was found to show increased activity in tissues exposed to aerosols with nicotine.

Laser-focused look at spinning electrons shatters world record for precision

The Compton polarimeter’s laser system, used to measure the parallel spin of electrons, is aligned during the Calcium Radius Experiment at Jefferson Lab.
Photo Credit: Jefferson Lab /Dave Gaskell

Scientists are getting a more detailed look than ever before at the electrons they use in precision experiments.

Nuclear physicists with the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility have shattered a nearly 30-year-old record for the measurement of parallel spin within an electron beam – or electron beam polarimetry, for short. The achievement sets the stage for high-profile experiments at Jefferson Lab that could open the door to new physics discoveries.

In a peer-reviewed paper published in the journal Physical Review C, a collaboration of Jefferson Lab researchers and scientific users reported a measurement more precise than a benchmark achieved during the 1994-95 run of the SLAC Large Detector (SLD) experiment at the SLAC National Accelerator Laboratory in Menlo Park, California.

“No one has measured the polarization of an electron beam to this precision at any lab, anywhere in the world,” said Dave Gaskell, an experimental nuclear physicist at Jefferson Lab and a co-author on the paper. “That’s the headline here. This isn’t just a benchmark for Compton polarimetry, but for any electron polarization measurement technique.”

Compton polarimetry involves detecting photons – particles of light – scattered by charged particles, such as electrons. That scattering, aka the Compton effect, can be achieved by sending laser light and an electron beam on a collision course.

Electrons – and photons – carry a property called spin (which physicists measure as angular momentum). Like mass or electric charge, spin is an intrinsic property of the electron. When particles spin in the same direction at a given time, the quantity is known as polarization. And for physicists probing the heart of matter on the tiniest scales, knowledge of that polarization is crucial.

“Think of the electron beam as a tool that you're using to measure something, like a ruler,” said Mark Macrae Dalton, another Jefferson Lab physicist and co-author on the paper. “Is it in inches or is it in millimeters? You have to understand the ruler in order to understand any measurement. Otherwise, you can’t measure anything.”

Resurrecting niobium for quantum science

The Josephson junction is the information-processing heart of the superconducting qubit. Pictured here is the niobium Josephson junction engineered by David Schuster of Stanford University and his team. Their junction design has resurrected niobium as a viable option as a core qubit material.
Image Credit: Alexander Anferov/the University of Chicago’s Pritzker Nanofabrication Facility.

For years, niobium was considered an underperformer when it came to superconducting qubits. Now scientists supported by Q-NEXT have found a way to engineer a high-performing niobium-based qubit and so take advantage of niobium’s superior qualities.

When it comes to quantum technology, niobium is making a comeback.

For the past 15 years, niobium has been sitting on the bench after experiencing a few mediocre at-bats as a core qubit material.

Qubits are the fundamental components of quantum devices. One qubit type relies on superconductivity to process information.

Touted for its superior qualities as a superconductor, niobium was always a promising candidate for quantum technologies. But scientists found niobium difficult to engineer as a core qubit component, and so it was relegated to the second string on Team Superconducting Qubit.

Now, a group led by Stanford University’s David Schuster has demonstrated a way to create niobium-based qubits that rival the state-of-the-art for their class.

Metal scar found on cannibal star

This artist’s impression shows the magnetic white dwarf WD 0816-310, where astronomers have found a scar imprinted on its surface as a result of having ingested planetary debris.  When objects like planets or asteroids approach the white dwarf they get disrupted, forming a debris disc around the dead star. Some of this material can be devoured by the dwarf, leaving traces of certain chemical elements on its surface.   Using ESO’s Very Large Telescope, astronomers found that the signature of these chemical elements changed periodically as the star rotated, as did the magnetic field. This indicates that the magnetic fields funneled these elements onto the star, concentrating them at the magnetic poles and forming the scar seen here.
Illustration Credit: ESO/L. Calçada

When a star like our Sun reaches the end of its life, it can ingest the surrounding planets and asteroids that were born with it. Now, using the European Southern Observatory’s Very Large Telescope (ESO’s VLT) in Chile, researchers have found a unique signature of this process for the first time — a scar imprinted on the surface of a white dwarf star. The results are published today in The Astrophysical Journal Letters.

“It is well known that some white dwarfs — slowly cooling embers of stars like our Sun — are cannibalizing pieces of their planetary systems. Now we have discovered that the star’s magnetic field plays a key role in this process, resulting in a scar on the white dwarf’s surface,” says Stefano Bagnulo, an astronomer at Armagh Observatory and Planetarium in Northern Ireland, UK, and lead author of the study.

Study sheds light on how neurotransmitter receptors transport calcium, a process linked with origins of neurological disease

Illustration Credit: Courtesy of McGill University

A new study from a team of McGill University and Vanderbilt University researchers is shedding light on our understanding of the molecular origins of some forms of autism and intellectual disability.

For the first time, researchers were able to successfully capture atomic resolution images of the fast-moving ionotropic glutamate receptor (iGluR) as it transports calcium. iGluRs and their ability to transport calcium are vitally important for many brain functions such as vision or other information coming from sensory organs. Calcium also brings about changes in the signaling capacity of iGluRs and nerve connections which are a key cellular events that lead to our ability to learn new skills and form memories.

iGluRs are also key players in brain development and their dysfunction through genetic mutations has been shown to give rise to some forms of autism and intellectual disability. However, basic questions about how iGluRs trigger biochemical changes in the brain’s physiology by transporting calcium have remained poorly understood.

In the study, the researchers took millions of snapshots of the iGluR protein in the act of transporting calcium, and unexpectedly discovered a temporary pocket that traps calcium on the outside of the protein. With this information at hand, they then used high-resolution electrophysiological recordings to watch the protein in motion as it transported calcium into the nerve cell.

Scientists assemble a richer picture of the plight and resilience of the foothill yellow-legged frog

Foothill yellow-legged frogs live in the flowing water of rivers and streams, so are especially vulnerable when these shrink to isolated pools.
Photo Credit: Brome McCreary / USGS

Up to only a few inches in length, with a lemon-hued belly, the foothill yellow-legged frog may seem unassuming. But its range once stretched from central Oregon to Baja California. In 2023, it was listed under the federal Endangered Species Act. Its rapidly decreasing range is due in part to a fungal pathogen called Batrachochytrium dendrobatidis, or Bd, that has devastated amphibians around the world.

A team of researchers, including UC Santa Barbara’s Andrea Adams, has conducted the most comprehensive study to date of disease dynamics in foothill yellow-legged frogs. The team’s data — sourced from both wild frogs and specimens in museum collections — enabled them to track patterns of infection across a large geographic range. In a study published in Royal Society Open Science, the researchers reveal that drought, rising temperatures and the increasing conversion of land for agriculture appear to be the largest factors driving Bd infection in this species.

The researchers aimed to assemble as much data as they could, both in space and time. They surveyed in the creeks and rivers of California and Oregon, where they swabbed wild yellow-legged frogs for the presence of Bd. It also led them into fluorescent-lit museum collections to sample specimens from as far back as the 1890s.

Snake robot could save lives


A search and rescue operation after an earthquake is a complicated task. One thing is to retrieve the potential survivors safely from the rubble. Even more difficult is finding out where they are.

It is precisely this kind of work that, among other things, a snake robot equipped with sensors and cameras could help solve. Such one is currently being developed by researchers at the Faculty of Engineering at the University of Southern Denmark.

They have recently published an article about the project in the journal Device.

We have made a robot capable of rectilinear locomotion - that is, movement in a straight line - as observed in snakes, says PhD student Burcu Seyidoğlu.

Future applications include search and rescue operations, field inspection, and space exploration. Especially in scenarios requiring navigation through confined spaces where body flexion is not feasible.

Vanishing Forests and Suffering Children: The Hidden Toll of Deforestation in Cambodia


Deforestation is suspected to have adverse impacts on child health. Investigating this phenomenon in Cambodia, a recent study sheds light on the devastating impact of prenatal exposure to deforestation on child health in Cambodia. The study reveals that children born in areas with recent deforestation suffer from lower birth weights and stunted growth. Moreover, pregnant women exposed to deforestation are more likely to experience anemia. These findings underscore the urgent need for effective targeted policies.

Deforestation, a critical consequence of human activity, has garnered significant attention due to its impact on environmental sustainability, biodiversity and climate change. However, an equally pressing yet less explored aspect is the relationship between deforestation and human health, especially in impoverished regions. Scientists have increasingly recognized the detrimental effects of deforestation on various aspects of human health, particularly among children. Studies reveal that children residing in areas with high deforestation rates are at an elevated risk of malaria, respiratory illnesses, diarrheal diseases, and malnutrition. This is particularly alarming given that these regions are often home to the most economically disadvantaged populations, worsening existing health disparities.

A Novel Method for Easy and Quick Fabrication of Biomimetic Robots with Life-Like Movement


Ultraviolet-laser processing is a promising technique for developing intricate microstructures, enabling complex alignment of muscle cells, required for building life-like biohybrid actuators, as shown by Tokyo Tech researchers. Compared to traditional complex methods, this innovative technique enables easy and quick fabrication of microstructures with intricate patterns for achieving different muscle cell arrangements, paving the way for biohybrid actuators capable of complex, flexible movements.

Biomimetic robots, which mimic the movements and biological functions of living organisms, are a fascinating area of research that can not only lead to more efficient robots but also serve as a platform for understanding muscle biology. Among these, biohybrid actuators, made up of soft materials and muscular cells that can replicate the forces of actual muscles, have the potential to achieve life-like movements and functions, including self-healing, high efficiency, and high power-to-weight ratio, which have been difficult for traditional bulky robots that require heavy energy sources. One way to achieve these life-like movements is to arrange muscle cells in biohybrid actuators in an anisotropic manner. This involves aligning them in a specific pattern where they are oriented in different directions, like what is found in living organisms. While previous studies have reported biohybrid actuators with significant movement using this technique, they have mostly focused on anisotropically aligning muscle cells in a straight line, resulting in only simple motions, as opposed to the complex movement of native muscle tissues such as twisting, bending, and shrinking. Real muscle tissues have a complex arrangement of muscle cells, including curved and helical patterns.

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