. Scientific Frontline

Friday, October 10, 2025

Climate change may increase the spread of neurotoxin in the oceans

The researchers’ findings raise concerns about how climate change may affect the levels of methylmercury in fish and shellfish.
Photo Credit: Johnér Bildbyrå AB

Climate-driven oxygen loss in the Black Sea thousands of years ago triggered the expansion of microorganisms capable of producing the potent neurotoxin methylmercury. That is shown in a new study published in Nature Water, led by Eric Capo at Umeå University, which suggests that similar processes could occur in today’s warming oceans.

Methylmercury is a highly toxic compound that accumulates in fish and seafood, posing severe health risks to humans. It is formed when certain microbes convert inorganic mercury under low-oxygen conditions.

Today, climate change is causing such oxygen-depleted areas to expand in coastal marine environments, including parts of the Baltic Sea. Warmer and more stagnant waters mix less efficiently, and increased algal blooms contribute to oxygen loss in deeper layers, creating ideal conditions for these microbes.

Lessons from Ascension’s shark troubles could help boost conservation

Sharks at the coast of Ascension Island.
Photo Credit Kate Downes

Understanding people’s attitudes to interactions with sharks could help halt the global decline of shark numbers, according to new research carried out on Ascension Island.  

In 2017, there were two non-fatal shark attacks at Ascension – a UK territory in the South Atlantic with a population of about 800 people.

Large numbers of sharks – mostly silky and Galapagos sharks – have affected the island’s recreational fishers, who often lose tackle and hooked fish before they can be landed.

The research team, led by the University of Exeter and ZSL, interviewed 34 islanders to assess perceptions of sharks.

“We found that human-shark conflict is driven by lots of different factors beyond just attacks – and understanding this is vital if we want shark conservation to work,” said Dr Claire Collins, from ZSL and the University of Exeter.

Microwaves for energy-efficient chemical reactions

Microwave reactions.
Ideally the microwave reactions can be driven by green energy, in which case the system could help reduce carbon dioxide by converting it into other useful chemicals.
Image Credit: ©2025 Kishimoto et al.
(CC BY-ND 4.0)

Some industrial processes used to create useful chemicals require heat, but heating methods are often inefficient, partly because they heat a greater volume of space than they really need to. Researchers including those from the University of Tokyo devised a way to limit heating to the specific areas required in such situations. Their technique uses microwaves, not unlike those used in home microwave ovens, to excite specific elements dispersed in the materials to be heated. Their system proved to be around 4.5 times more efficient than current methods.

While there’s more to climate change than power generation and carbon dioxide (CO2), reducing the need for the former and the output of the latter are critical matters that science and engineering strive to tackle. Under the broad banner of green transformation, Lecturer Fuminao Kishimoto from the Department of Chemical System Engineering at the University of Tokyo and his team explore ways to improve things like industrial processes. Their latest development could impact on some industries involved in chemical synthesis and may have some other positive offshoots. And their underlying idea is relatively straightforward.

Stem Cell Technique Could Preserve Endangered Bird Species

Avian stem cells in culture (blue, left) that be efficiently converted in large numbers into germ cells (green, right).
Image Credit: C. Lois

Birds are a critical part of the global ecosystem; they enable our food production through consumption of agricultural pests like aphids and rodents, and control the spread of diseases by eating insects like mosquitos and ticks. However, around 15 percent of all bird species now face risk of extinction—in Hawaii alone, 33 of the state's 45 native species are critically endangered.

Caltech researchers have now developed technology to freeze and preserve stem cells from birds that can then be reconstituted to help propagate populations.

The work was conducted by Caltech postdoctoral scholar Xi Chen as a collaboration between the USC laboratory of Qi-Long Ying and the Caltech laboratory of Carlos Lois, research professor of biology. The study is described in a paper in the journal Nature Biotechnology.

Thursday, October 9, 2025

Programmable proteins use logic to improve targeted drug delivery

Therapies that are sensitive to multiple biomarkers could allow medicines to reach only the areas of the body where they are needed. The diagram above shows three theoretical biomarkers that are present in specific, sometimes overlapping areas of the body. A therapy designed to find the unique area of overlap between the three will act on only that area.
Image Credit: DeForest et al./Nature Chemical Biology

Targeted drug delivery is a powerful and promising area of medicine. Therapies that pinpoint the exact areas of the body where they’re needed — and nowhere they’re not — can reduce the medicine dosage and avoid potentially harmful “off target” effects elsewhere in the body. A targeted immunotherapy, for example, might seek out cancerous tissues and activate immune cells to fight the disease only in those tissues.

The tricky part is making a therapy truly “smart,” where the medicine can move freely through the body and decide which areas to target.

Critically endangered shark meat sold in US stores

Image Credit: Gillie Sibrian/UNC-Chapel Hill

Critically endangered shark meat is being sold at American grocery stores — often under misleading labels — according to a new study conducted by researchers at UNC-Chapel Hill.

The researchers purchased and DNA barcoded 29 shark meat products from stores in North Carolina; Washington, D.C.; Florida and Georgia and from online vendors. DNA testing revealed 11 different species of shark, yet 93% of the samples were ambiguously labeled as “shark” or “mako shark” at stores with no species-level identification.

Of the 11 species sold in stores, three are listed as critically endangered by the International Union for the Conservation of Nature — the great hammerhead, scalloped hammerhead and tope. Another species sold in stores, the shortfin mako shark, is listed as endangered by the IUCN.

The U.S. Food and Drug Administration only requires sellers to label shark meat as “shark,” with no specific species name required.

AI tool offers deep insight into the immune system

scHDeepInsight.
An overview of the process linking single-cell RNA input, image conversion and CNN analysis, to hierarchical immune cell classification.
Image Credit: ©2025 Tsunoda et al.
(CC BY-ND 4.0)

Researchers explore the human immune system by looking at the active components, namely the various genes and cells involved. But there is a broad range of these, and observations necessarily produce vast amounts of data. For the first time, researchers including those from the University of Tokyo built a software tool which leverages artificial intelligence to not only offer a more consistent analysis of these cells at speed but also categorizes them and aims to spot novel patterns people have not yet seen.

Our immune system is important — it’s impossible to imagine complex life existing without it. This system, comprising different kinds of cells, each playing a different role, helps to identify things that threaten our health, and take actions to defend us. They are both very effective, but also far from perfect; hence, the existence of diseases such as the notorious acquired immunodeficiency syndrome, or AIDS. And recent earth-shattering issues, such as the coronavirus pandemic, serve to highlight the importance of research around this intricate yet powerful system.

Patient Treatment Shows: Brain Pacemaker Helps with Stuttering

The position of the implanted electrodes in the patient’s basal ganglia.
Image Credit: Kell et al., J Fluency Dis 2025

Deep brain stimulation, a method where specific brain regions are activated using implanted electrodes, is a well-established approach for treating movement disorders such as Parkinson’s disease. Researchers led by Christian Kell from Frankfurt University Medicine as well as Nils Warneke and Katrin Neumann from Münster University Hospital have now successfully alleviated severe stuttering in a person with developmental stuttering using this method for the first time. The researchers are now preparing a study to test the therapy on additional individuals who experience severe stuttering.

While stuttering was believed to have purely psychological causes up until about 30 years ago, scientists today attribute it to a variety of factors capable of contributing to its development. For instance, several genes have been identified that increase the risk of stuttering, and anatomically, the brains of individuals with speech flow disorders show differences in neural connections and brain activity compared to those who speak fluently. 

Burning issue: study finds fire a friend to some bees, a foe to others

Native bee species the megachile aufrions.
Photo Credit: Kit Prendergast

New Curtin University research has found the impact of bushfires and prescribed burns on global bee populations is highly varied, with some species benefiting from fire while others face severe risks.

The study, led by Adjunct Research Fellow Dr Kit Prendergast from Curtin’s School of Molecular and Life Sciences, examined 148 studies from around the world to understand how fire impacts bees.

The review considered the severity, frequency and duration of fires, along with the different characteristics of bees, such as where they nest, their body size, how specialized their diet is and whether they live alone or in groups.

Dr Prendergast said while declining pollinator numbers are being increasingly recognized as a major threat to biodiversity and sustainability, little was known until now about how they respond to fires that are becoming more frequent and severe due to climate change and land management practices.

Air Pollution Can Contribute to Obesity and Diabetes

The most significant sources of fine air pollutants include exhaust fumes from cars, industrial plants and heating systems, as well as emissions from construction sites and forest fires.
Photo Credit: 
Uvi D

Long-term exposure to fine air pollution can impair metabolic health by disrupting the normal function of brown fat in mice. A study co-led by the University of Zurich shows that this occurs through complex changes in gene regulation driven by epigenetic mechanisms. The results demonstrate how environmental pollutants contribute to the development of insulin resistance and metabolic diseases.

There is growing evidence that air pollution is not just harmful to our lungs and heart, but also plays a significant role in the development of metabolic disorders like insulin resistance and type 2 diabetes. A new study co-led by Francesco Paneni, professor at the Center for Translational and Experimental Cardiology of the University of Zurich (UZH) and the University Hospital Zurich (USZ), and Sanjay Rajagopalan, professor at the Case Western Reserve University, Cleveland, now sheds light on the topic.

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