Scientists reveal how exercise protects the brain from Alzheimer’s

 Researchers at UC San Francisco have identified a biological process that may explain why exercise sharpens thinking and memory. Their findings suggest that physical activity strengthens the brain's built in defense system, helping protect it from age related damage.

As people grow older, the blood-brain barrier becomes more fragile. This tightly packed network of blood vessels normally shields the brain from harmful substances circulating in the bloodstream. Over time, however, it can become leaky, allowing damaging compounds to enter brain tissue. The result is inflammation, which is linked to cognitive decline and is commonly seen in disorders such as Alzheimer's disease

Several years ago, the research team discovered that exercising mice produced higher levels of an enzyme called GPLD1 in their livers. GPLD1 appeared to rejuvenate the brain, but there was a mystery. The enzyme itself cannot cross into the brain, leaving scientists unsure how it delivered its cognitive benefits.

The new research provides an answer.

How GPLD1 Reduces Brain Inflammation

The scientists found that GPLD1 influences another protein known as TNAP. As mice age, TNAP builds up in the cells that form the blood-brain barrier. This buildup weakens the barrier and increases leakiness. When mice exercise, their livers release GPLD1 into the bloodstream. The enzyme travels to the blood vessels surrounding the brain and removes TNAP from the surface of those cells, helping restore the barrier's integrity.

"This discovery shows just how relevant the body is for understanding how the brain declines with age," said Saul Villeda, PhD, associate director of the UCSF Bakar Aging Research Institute.

Villeda is the senior author of the paper, which was published in the journal Cell on Feb. 18.

Pinpointing TNAP's Role in Cognitive Decline

To determine how GPLD1 exerts its effects, the team focused on what the enzyme does best. GPLD1 cuts specific proteins from the surface of cells. Researchers searched for tissues containing proteins that could serve as targets and suspected that some of these proteins might accumulate with age.

Cells in the blood-brain barrier stood out because they carried several possible GPLD1 targets. When the scientists tested these proteins in the lab, only one was trimmed by GPLD1: TNAP.

Further experiments confirmed TNAP's importance. Young mice genetically modified to produce excess TNAP in the blood-brain barrier showed memory and cognitive problems similar to those seen in older animals.

When researchers reduced TNAP levels in 2-year-old mice -- which are the equivalent of 70 human years -- the blood-brain barrier became less permeable, inflammation decreased, and the animals performed better on memory tests.

"We were able to tap into this mechanism late in life, for the mice, and it still worked," said Gregor Bieri, PhD, a postdoctoral scholar in Villeda's lab and co-first author of the study.

Source: ScienceDaily

“Celtic curse” hotspots found in Scotland and Ireland with 1 in 54 at risk

 People with roots in the Outer Hebrides and northwest Ireland face the highest known risk of developing hemochromatosis, a genetic disorder that causes the body to absorb and store too much iron. Over time, that excess iron can build up to dangerous levels.

This is the first time researchers have mapped genetic risk for hemochromatosis, sometimes called the 'Celtic curse', across the UK and Ireland. The condition has long been known to affect Scottish and Irish populations at higher rates, but until now its geographic distribution had not been clearly char Experts say the findings could help health officials focus genetic screening in the areas most affected, allowing people at risk to be identified earlier and treated before serious complications develop.

Iron Overload Can Damage Organs Over Decades

Hemochromatosis often develops slowly. Excess iron can accumulate in organs for years or even decades before symptoms appear. If left untreated, it can lead to liver damage, liver cancer, arthritis, and other serious health problems. Early diagnosis makes a major difference. Regular blood donation to lower iron levels is a simple and effective treatment that can prevent much of the harm.

The disease is caused by inherited changes in DNA known as genetic variants. In the UK and Ireland, the main risk factor is a variant called C282Y.

Researchers at the University of Edinburgh analyzed genetic information from more than 400,000 people who took part in the UK BioBank and Viking Genes studies. They examined how common the C282Y variant was in 29 regions across the British Isles and Ireland.

Where the C282Y Gene Variant Is Most Common

The highest rates were found among people with ancestry from northwest Ireland, where about one in 54 people are estimated to carry the variant. The Outer Hebrides followed closely at one in 62, and Northern Ireland at one in 71.

Mainland Scotland also showed elevated risk, particularly in Glasgow and southwest Scotland. In those areas, about one in 117 people carry the variant, reinforcing the long standing 'Celtic Curse' nickname.

Because the combined genetic risk is so high in these regions, researchers say targeted screening there would likely identify the greatest number of people with the condition.

Diagnosis Patterns and Possible Under Detection

The team also reviewed NHS England records and found more than 70,000 diagnosed cases of hemochromatosis. White Irish individuals were nearly four times more likely to be diagnosed than white British individuals.ted.

Source: ScienceDaily

Can solar storms trigger earthquakes? Scientists propose surprising link

 Scientists at Kyoto University have developed a theoretical model examining whether disturbances in the ionosphere could apply electrostatic forces deep within the Earth's crust. Under certain conditions, these forces might contribute to the start of large earthquakes.

The research is not designed to forecast earthquakes. Instead, it outlines a possible physical mechanism showing how shifts in ionospheric charge levels -- triggered by intense solar activity such as solar flares -- might interact with already weakened areas of the crust and influence how fractures develop.

How the Ionosphere Could Affect Fault Zones

In this model, cracked regions of the crust are thought to contain water at extremely high temperatures and pressures, possibly in a supercritical state. Electrically, these fractured zones may act like capacitors. They are coupled both to the Earth's surface and to the lower ionosphere, creating a vast electrostatic system that links the ground to the upper atmosphere.

When solar activity surges, electron density in the ionosphere can rise significantly. This can produce a negatively charged layer in the lower ionosphere. Through capacitive coupling, that charge may generate intense electric fields inside microscopic voids within fractured rock. The resulting electrostatic pressure could approach levels similar to tidal or gravitational stresses that are already known to influence fault stability.

According to the team's calculations, ionospheric disturbances tied to major solar flares -- involving increases in total electron content of several tens of TEC units -- might create electrostatic pressures of several megapascals within these crustal voids.

Ionospheric Anomalies Observed Before Major Quakes

Unusual ionospheric behavior has often been detected before powerful earthquakes. Observations have included spikes in electron density, drops in ionospheric altitude, and slower propagation of medium-scale traveling ionospheric disturbances. Traditionally, scientists have interpreted these changes as effects caused by stress building up inside the crust.

This new framework offers an additional perspective. It suggests a two way interaction in which processes inside the Earth can influence the ionosphere, while ionospheric disturbances may also send feedback forces back down into the crust. The model connects space weather and seismic activity without claiming that solar activity directly causes earthquakes.

Source: ScienceDaily

Lost fossils reveal sea monsters that took over after Earth’s greatest extinction

 About 250 million years ago, a region that is now a harsh desert in remote northwestern Australia lay along the edge of a shallow bay connected to a vast prehistoric ocean. Fossils collected there more than six decades ago and largely overlooked in museum collections are now reshaping scientists' understanding of how land animals first returned to the sea and spread across the globe.

The end-Permian mass extinction, the most devastating die-off in Earth's history, struck about 252 million years ago and was followed by extreme global warming. In its aftermath, modern-style marine ecosystems began to take shape at the start of the Age of Dinosaurs (or Mesozoic era). During this critical window, the earliest sea-going tetrapods (limbed vertebrates), including amphibians and reptiles, emerged and quickly became dominant aquatic apex predators. Most fossils of these early marine hunters have been found in the northern hemisphere. Comparable discoveries from the southern hemisphere have been rare and remain poorly documented.

Now, a fresh analysis of 250 million-year-old fossils from the Kimberly region of northern Western Australia reveals a surprisingly diverse group of marine amphibians with unexpected global connections across ancient oceans.

Lost Fossils Rediscovered After 50 Years

Marine amphibian fossils were first uncovered in Australia during expeditions in the 1960s and 1970s. The specimens were divided between museums in Australia and the U.S.A. Research published in 1972 concluded that the material represented a single species, Erythrobatrachus noonkanbahensis. The species was identified from several skull fragments eroding out of rock at Noonkanbah cattle station, east of the remote Kimberly town of Derby.

Over the following decades, the original Erythrobatrachus fossils were misplaced. Their disappearance triggered an international search through museum collections. In 2024, the long-lost specimens were finally located, allowing researchers to reexamine these puzzling marine amphibians with modern techniques.

Early Marine Amphibians After the Permian Extinction

Erythrobatrachus belonged to a group known as trematosaurid temnospondyls. These animals were 'crocodile-like' relatives of today's salamanders and frogs and could reach lengths of up to 2 m. Trematosaurids are especially significant because their fossils appear in coastal rock deposits formed less than 1 million years after the end-Permian mass extinction. As a result, they represent the oldest clearly recognizable group of Mesozoic marine tetrapods.

A closer look at the rediscovered skull fragments revealed an important surprise. The bones once attributed to a single species actually came from at least two different trematosaurids: Erythrobatrachus and a second form belonging to the genus Aphaneramma.

Source: ScienceDaily

Atacama surprise: The world’s driest desert is teeming with hidden life

 New research reveals that life beneath the surface of one of the driest places on Earth is far more resilient and diverse than many scientists expected. An international team led by the University of Cologne studied tiny soil worms known as nematodes in Chile's Atacama Desert. Often compared to polar deserts, the Atacama is considered one of the most arid regions in the world. With almost no rainfall, high salt levels in the soil, and dramatic temperature swings, it ranks among the planet's most extreme environments.

Despite these punishing conditions, researchers found thriving communities of nematodes. Specialists in zoology, ecology, and botany worked together to uncover how different species manage to survive there. Their findings, published in Nature Communications under the title "Geographic distribution of nematodes in the Atacama is associated with elevation, climate gradients and parthenogenesis," provide new insight into how biodiversity patterns are shaped by environmental factors across a landscape.

Why Nematodes Matter in Soil Ecosystems

Nematodes are among the most widespread and numerous animals in soil ecosystems. With countless species worldwide, they play a vital role in maintaining ecological balance. These microscopic organisms help control bacterial populations, support nutrient cycling, and serve as indicators of soil health.

They are also remarkably adaptable. Nematodes can be found in deep ocean sediments, Arctic environments, and even highly saline soils. Their ability to endure such extremes makes them ideal organisms for studying how life persists under environmental stress.

"Soils are important for the performance of an ecosystem, for example for carbon storage and nutrient supply. This is why understanding the organisms, i.e. not microbes, but multicellular animals, that live there is so important," says Dr Philipp Schiffer from the University of Cologne's Institute of Zoology and one of the authors of the study. "Data on soils in extreme ecosystems such as the Atacama Desert is still scarce."

Studying Life at the Dry Limit

The team is part of the Collaborative Research Centre 1211 "Earth -- Evolution at the Dry Limit," which has conducted long-term research in the Atacama. For this project, scientists examined six distinct regions, each with different environmental conditions. These included higher elevation areas with more moisture and vegetation, highly saline zones exposed to intense UV radiation, and fog-fed oases where plant life flourishes against the odds.

Researchers collected soil samples from sand dunes, salt flats, riverbeds, and mountainous terrain. They analyzed biodiversity, reproductive strategies, and population structures among the nematodes living in each environment.

Source: ScienceDaily

ChatGPT as a therapist? New study reveals serious ethical risks

 As more people seek mental health advice from ChatGPT and other large language models (LLMs), new research suggests these AI chatbots may not be ready for that role. The study found that even when instructed to use established psychotherapy approaches, the systems consistently fail to meet professional ethics standards set by organizations such as the American Psychological Association.

Researchers from Brown University, working closely with mental health professionals, identified repeated patterns of problematic behavior. In testing, chatbots mishandled crisis situations, gave responses that reinforced harmful beliefs about users or others, and used language that created the appearance of empathy without genuine understanding.

"In this work, we present a practitioner-informed framework of 15 ethical risks to demonstrate how LLM counselors violate ethical standards in mental health practice by mapping the model's behavior to specific ethical violations," the researchers wrote in their study. "We call on future work to create ethical, educational and legal standards for LLM counselors -- standards that are reflective of the quality and rigor of care required for human-facilitated psychotherapy."

The findings were presented at the AAAI/ACM Conference on Artificial Intelligence, Ethics and Society. The research team is affiliated with Brown's Center for Technological Responsibility, Reimagination and Redesign.

How Prompts Shape AI Therapy Responses

Zainab Iftikhar, a Ph.D. candidate in computer science at Brown who led the study, set out to examine whether carefully worded prompts could guide AI systems to behave more ethically in mental health settings. Prompts are written instructions designed to steer a model's output without retraining it or adding new data.

"Prompts are instructions that are given to the model to guide its behavior for achieving a specific task," Iftikhar said. "You don't change the underlying model or provide new data, but the prompt helps guide the model's output based on its pre-existing knowledge and learned patterns.

"For example, a user might prompt the model with: 'Act as a cognitive behavioral therapist to help me reframe my thoughts,' or 'Use principles of dialectical behavior therapy to assist me in understanding and managing my emotions.' While these models do not actually perform these therapeutic techniques like a human would, they rather use their learned patterns to generate responses that align with the concepts of CBT or DBT based on the input prompt provided."

People regularly share these prompt strategies on platforms like TikTok, Instagram, and Reddit. Beyond individual experimentation, many consumer facing mental health chatbots are built by applying therapy related prompts to general purpose LLMs. That makes it especially important to understand whether prompting alone can make AI counseling safer.

Source: ScienceDaily