Tracing the flow of water with DNA

Oliver Schilling analyzing spring water at Mount Fuji.
Photo Credit: T. Schilling

Environmental DNA analysis of microbial communities can help us understand how a particular region’s water cycle works. Basel hydrogeologist Oliver Schilling recently used this method to examine the water cycle on Mount Fuji. His results have implications for Switzerland as well.

Where does the water come from that provides drinking water to people in a particular region? What feeds these sources and how long does it take for groundwater to make its way back up to the surface? This hydrological cycle is a complex interplay of various factors. A better grasp of the system allows us to understand, for example, why pollution is worse in some spots than others, and it can help us implement sustainable water management policies and practices.

Environmental DNA (eDNA) provides some important data to improve our understanding. In combination with the evaluation of other natural tracers – noble gases, for example – this microbial data provides important glimpses into the flow, circulation and functioning of complex groundwater systems. “It’s a vast toolbox that’s new to our field of research,” says Oliver Schilling, Professor of Hydrogeology at the University of Basel and at Eawag, the Swiss Federal Institute of Aquatic Science and Technology. Quantitative hydrogeology maps out where and how quickly new groundwater will accumulate.

Coating bubbles with protein results in a highly stable contrast agent for medical use

Bacteria produce gas vesicles
Image Credit: Aalto University

Inspired by the bubbles bacteria create inside their cells, researchers developed a similar system by coating tiny gas vesicles with protein. The resulting bubbles are safe, highly stable, and function as contrast agent in medical applications. They could be used to diagnose, for example, cardiological issues, blood flow, and liver lesions.

Bacteria produce gas vesicles, tiny thin-walled sacs filled with air or fluid, to help them float. This phenomenon has captured the attention of scientists who see potential for similar bubble-based designs in fields like medicine. A team of researchers at Aalto University’s Department of Applied Physics, led by Professor Robin Ras, have now used the same idea to create a new kind of contrast agent for use in medical applications such as ultrasound imaging. The research was recently published in the Proceedings of the National Academy of Sciences.

Magnetic method to clean PFAS contaminated water

Researchers at The University of Queensland have pioneered a simple, fast and effective technique to remove PFAS chemicals from water.  

Using a magnet and a reusable absorption aid that they developed, polymer chemist Dr Cheng Zhang and PhD candidate Xiao Tan at the Australian Institute for Bioengineering and Nanotechnology have cleared 95 per cent of per- and polyfluoroalkyl substances (PFAS) from a small amount of contaminated water in under a minute.

“Removing PFAS chemicals from contaminated waters is urgently needed to safeguard public and environmental health,” Dr Zhang said.

“But existing methods require machinery like pumps, take a lot of time and need their own power source.

“Our method shows it is possible to remove more of these chemicals in a way that is faster, cheaper, cleaner, and very simple.

How Huntington’s disease affects different neurons

Neuroscientists at MIT have shown that two distinct cell populations in the striatum are affected differently by Huntington’s disease.
Image Credit: Leterrier, NeuroCyto Lab, INP, Marseille, France

In patients with Huntington’s disease, neurons in a part of the brain called the striatum are among the hardest-hit. Degeneration of these neurons contributes to patients’ loss of motor control, which is one of the major hallmarks of the disease.

Neuroscientists at MIT have now shown that two distinct cell populations in the striatum are affected differently by Huntington’s disease. They believe that neurodegeneration of one of these populations leads to motor impairments, while damage to the other population, located in structures called striosomes, may account for the mood disorders that are often see in the early stages of the disease.

“As many as 10 years ahead of the motor diagnosis, Huntington’s patients can experience mood disorders, and one possibility is that the striosomes might be involved in these,” says Ann Graybiel, an MIT Institute Professor, a member of MIT’s McGovern Institute for Brain Research, and one of the senior authors of the study.

Using single-cell RNA sequencing to analyze the genes expressed in mouse models of Huntington’s disease and postmortem brain samples from Huntington’s patients, the researchers found that cells of the striosomes and another structure, the matrix, begin to lose their distinguishing features as the disease progresses. The researchers hope that their mapping of the striatum and how it is affected by Huntington’s could help lead to new treatments that target specific cells within the brain.

The visibility of stars in the night sky quickly decreases

These astronaut photos of parts of Calgary (Canada) show examples of how lighting changed between 2010 and 2021. Here is a picture from 2010.
 Image Credit: Courtesy of the Earth Science and Remote Sensing Unit, NASA Johnson Space Center, georeferencing by GFZ Potsdam

This is shown by a science study based on a worldwide Citizen Science project on light pollution, which has collected data in the past eleven years.

People see fewer and fewer stars in the night sky worldwide. The cause is probably light pollution in the evening and night hours, which increases by seven to ten percent per year. This rate of change is greater than satellite measurements of artificial light missions on Earth suggested. This is the finding of a study in the science magazine, carried out by a research group led by Dr. Christopher Kyba from the German GeoForschungsZentrum GFZ and the Ruhr University Bochum with researchers from the GFZ and the NOIRLab of the US National Science Foundation. As part of the Citizen Science project "Globe at Night", they evaluated more than 50,000 observations with the naked eye of civil scientists around the world from 2011 to 2022. The study also shows that the Citizen Science data are an important addition to previous measurement methods.

Low-impact human recreation changes wildlife behavior

Camera trap images revealed how animals changed their use of areas around hiking trails in Glacier National Park during and after a COVID-19 closure.
Photo Credit: courtesy of Mammal Spatial Ecology and Conservation Lab at Washington State University.

Even without hunting rifles, humans appear to have a strong negative influence on the movement of wildlife. A study of Glacier National Park hiking trails during and after a COVID-19 closure adds evidence to the theory that humans can create a “landscape of fear” like other apex predators, changing how species use an area simply with their presence.

Washington State University and National Park Service researchers found that when human hikers were present, 16 out of 22 mammal species, including predators and prey alike, changed where and when they accessed areas. Some completely abandoned places they previously used, others used them less frequently, and some shifted to more nocturnal activities to avoid humans.

“When the park was open to the public, and there were a lot of hikers and recreators using the area, we saw a bunch of changes in how animals were using that same area,” said Daniel Thornton, WSU wildlife ecologist and senior author on the study published in the journal Scientific Reports. “The surprising thing is that there’s no other real human disturbance out there because Glacier is such a highly protected national park, so these responses really are being driven by human presence and human noise.”

Knowledge is Flowing: Connecting the Dots and Chipping Away at Modeling Uncertainty

UConn researchers are working to improve the modeling for understanding how water moves through the ecosystem
Photo Credit: SFLORG stock image

When working to find solutions for complex problems, it can be easy to focus either too broadly or too narrowly. Oftentimes the answers lie somewhere in the middle.

UConn Department of Natural Resources and the Environment researcher James Knighton and his group are working to connect two fields of research – one with a global focus, the other with a local focus — to overcome a disconnect and improve models used for studying how water moves through the earth’s systems. The study is published in the Journal of Advances in Modeling Earth Systems.

Knighton explains that projections for climate change over the next 50 to 100 years rely on complex models called general circulation models or earth systems models.

“In those models, people try to simulate the flow of the atmosphere, the flow of the ocean, water exchanges with the continents, how that water moves as freshwater out to the ocean, and how a significant portion of it moves back to the atmosphere. About half of all rain that falls on land goes back to the atmosphere directly and most of that through plants.”

Researchers uncover secrets on how Alaska’s Denali Fault formed

Denali fault trace cutting through Gakona Glacier, just after the 2002 earthquake. Tracks are from where geologists measured the fault offset.
Photo Credit: Peter Haeussler/U.S. Geological Survey. Licensed under Public Domain.

A study by Brown researchers finds that changes in tectonic plate thickness across the Denali Fault in Alaska impacts where it is located, shedding light on how major faults and earthquakes occur.

When the rigid plates that make up the Earth’s lithosphere brush against one another, they often form visible boundaries, known as faults, on the planet’s surface. Strike-slip faults, such as the San Andreas Fault in California or the Denali Fault in Alaska, are among the most well-known and capable of seriously powerful seismic activity.

Studying these faults can help geoscientists not only better understand the process of plate tectonics, which helped form the planet’s continents and mountains, but also better model their earthquake hazards. The problem is that most studies on these types of faults are (quite literally) shallow, looking only at the upper layer of the Earth’s crust where the faults form.

New research led by Brown University seismologists digs deeper into the Earth, analyzing how the part of the fault that’s near the surface connects to the base of the tectonic plate in the mantle. The scientists found that changes in how thick the plate is and how strong it is deep into the Earth play a key role in the location of Alaska’s Denali Fault, one of the world’s major strike-slip faults.

Sensing the Odor Molecules on Graphene Surface Layered with Self-Assembled Peptides

Graphene-based olfactory sensors that can detect odor molecules based on the design of peptide sequences were recently demonstrated by researchers at Tokyo Tech. The findings indicated that graphene field-effect transistors (GFETs) functionalized with designable peptides can be used to develop electronic devices that mimic olfactory receptors and emulate the sense of smell by selectively detecting odor molecules.

Olfactory sensing or odor sensing is an integral part of many industries including healthcare, food, cosmetics, and environmental monitoring. At present, the most commonly used technique for detecting and estimating odor molecules is gas chromatography–mass spectrometry (GC–MS). Though very effective, GC–MS has some limitations, such as its bulky setup and limited sensitivity. As a consequence, scientists have been looking for more sensitive and easy-to-use alternatives.

In recent years, graphene field-effect transistors (GFETs) have begun being used to develop highly sensitive and selective odor sensors by integrating with olfactory receptors, also known as electronic noses. The atomically flat surfaces and high electron mobility of graphene surfaces make GFETs ideal for adsorbing odor molecules. However, the application of GFET as electrical biosensors with the receptors is severely limited by factors, such as the fragility of receptors and the lack of alternative synthetic molecules that can function as olfactory receptors.

Why faces might not be as attention-grabbing as we think

Data from the study’s 30 participants revealed they looked at the faces of just 16 per cent of the people they walked past.
Photo Credit: John Cameron

Research combining wearable eye-tracking technology and AI body detection software suggests our eyes aren’t drawn to the faces of passers-by as much as previously thought.

Faces are key to everyday social interaction. Just a brief glance can give us important signals about someone’s emotional state, intentions and identity that helps us to navigate our social world.

But researchers studying social attention – how we notice and process the actions and behaviors of others in social contexts – have been mostly limited to lab-based studies where participants view social scenes on computer screens. Now, researchers from the School of Psychology at UNSW Science have developed a new approach that could enable more studies of social attention in natural settings.

The novel method correlates eye-movement data from wearable eye-tracking glasses with analysis from an automatic face and body detection algorithm to record when and where participants looked when fixating on other people. The methodology, detailed in the journal Scientific Reports, could have a range of future applications in settings from clinical research to sports science.