Comment

Comment by Dr. Krishna Kumari Challa yesterday

Researchers uncover hidden mechanism behind congenital heart disease

Congenital heart disease affects approximately two in every 100 newborns globally. But why does it occur? An important part of the answer may lie in a previously unknown mechanism on the surface of our cells. Researchers identified this mechanism in a new study.
They have discovered a new communication system on the exterior of the cell that is crucial for the proper formation of the heart during embryonic development.

The mechanism is located in the primary cilium, a microscopic "antenna" that protrudes from most cells in the body. The cilium's role is to interpret the body's signaling molecules, enabling the cell to determine whether it should divide, move or die, for example.

In the study, the researchers show that three proteins, TAK1, TAB2 and PKA-Cα, function as a signaling hub within the cell's antenna and play a significant role in heart formation.

These proteins act as molecular instructions that tell stem cells when and how to develop into heart muscle cells. However, genetic alterations can disrupt this communication, causing 'antenna defects,' which may lead to congenital heart defects.

The researchers observed effects not only in the heart.

In the study, the rare genetic mutations were identified in patients with so-called syndromic congenital heart disease. Syndromic heart defects are caused by an underlying genetic syndrome that often also leads to defects and associated conditions in other organs.

At the same time, experiments in zebrafish and detailed studies of cilia in other tissues suggested that the mechanism is also important for the development of other organs.

When the ciliary mechanism fails, it typically affects the development of several other organs as well. This may explain why some patients with congenital heart disease also have defects and related conditions affecting the brain, kidneys and skeleton. The mechanism provides a unifying explanation for diseases that we have previously struggled to understand.
The researchers therefore think that the discovery could help improve the understanding and treatment of a wide range of diseases caused by defects in the primary cilium.
This new knowledge may eventually make it easier to identify patients early and develop targeted treatments.

TAK1 operates at the primary cilium in non-canonical TGFB/BMP signaling to control heart development, PLOS Biology (2026). DOI: 10.1371/journal.pbio.3003902

Comment by Dr. Krishna Kumari Challa yesterday

The brain's electrical signatures shift as tinnitus becomes chronic

Ears are built to listen to sounds from the world around us, but for some people, the sound comes from within. Tinnitus causes people to hear ringing or other noises in one or both ears or in their heads, even when there is no actual sound outside. While tinnitus is frequently associated with hearing loss, a substantial proportion of individuals with clinically normal hearing thresholds still experience it, and the underlying mechanism remains murky to scientists. A recent study investigated how brain network patterns change as tinnitus progresses from a new condition to a long-term chronic one in people with clinically normal hearing.

After recording the electrical activity in the brains of people with acute and chronic tinnitus, the researchers found that the two conditions have very different neurophysiological profiles. People with recent-onset tinnitus showed an imbalance between two important brain networks: the salience network, which detects salient or potentially threatening signals, and the executive control network, which supports attention and decision-making. The brain significantly increases its focus on the former while decreasing the latter's activity. Those with chronic tinnitus showed much more balanced switching between these networks, meaning the brain began to adapt rather than worsen.

Meng-Fang Gong et al, EEG microstates and dynamic functional connectivity reveal stage-specific brain networks in subjective tinnitus, iScience (2026). DOI: 10.1016/j.isci.2026.116995

Comment by Dr. Krishna Kumari Challa yesterday

Recent studies have found these plastics in the placenta, amniotic fluid and even a baby's first stool. In general, the placenta, an organ that develops during pregnancy, is responsible for providing oxygen and essential nutrients to the developing fetus while removing waste products and keeping harmful substances at bay. However, researchers are concerned that, because of their extremely small size, MNPs might cross a placenta-like barrier and disrupt hormones.

In this study, the researchers investigated the interaction among a mother, the placenta and a developing baby via a tri-culture model, in which they grew three different types of human cells together to act like a real body system. The model included BeWo cells for the placental barrier, HUVEC cells for the fetal blood vessels and H295R cells for the fetal adrenal glands, which produce hormones such as adrenaline and sex steroids.

To track the particles' journey, the researchers tagged the MNPs with a tiny fluorescent marker and added them to the maternal side of the model. They then watched to see whether the particles could make their way to the fetal side.

They saw that smaller particles moved through the barrier more easily than larger ones. PMMA showed the largest measured transfer, with about 11% reaching the fetal-side chamber after three days.

High-powered 3D microscopes revealed that the plastics weren't just floating around the cells but had actually entered them. No particles were found in the H295R cells, but very small polystyrene particles between 50 nm and 200 nm were found inside both the BeWo and HUVEC cells.
The MNPs also acted as endocrine disruptors. Polystyrene caused a drop in estrogen, a hormone essential for maintaining a healthy pregnancy, and decreased the expression of the CYP17 gene in fetal cells, which is essential for the synthesis of steroid hormones. Almost all the other plastics tested reduced levels of a hormone called etiocholanolone, which sends vital signals to the growing fetus.

These findings warn that various types of microplastics may disrupt hormones during pregnancy and affect placental function. The researchers say more work is needed to understand what this could mean for a baby's development and exactly how these tiny plastic particles disrupt the body's hormone-making machinery.

Jeske van Boxel et al, Effects of different micro- and nanoplastic polymers on steroidogenesis in a feto-placental in vitro model, Molecular and Cellular Endocrinology (2026). DOI: 10.1016/j.mce.2026.112871

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Microplastics cross placenta-like barrier and disrupt key pregnancy hormones in new cell model study

Tiny, near-invisible fragments of plastic shed from the products we use every day through sunlight and mechanical wear have been quietly working their way deep into the human body. Microplastics have already been found in the human brain, semen and even the placenta. A recent study investigated how these micro- and nanoplastics (MNPs) might move through the placenta and whether they affect a baby's development.

Since human pregnancy is too complex to study and raises ethical concerns, the team built a miniature lab model that mimics the interaction among a mother, the placenta and the fetus. It combines three types of human cells to represent the different layers of the placental barrier and the fetal adrenal gland. They tested several types of plastics we encounter daily, including PMMA (transparent, glass alternative), PET (used in soda bottles), PVC (used in pipes and packaging) and polystyrene (used in packing materials).

All the types of plastic tested were able to move from the mother's side through the placental barrier to the baby's side. The MNPs didn't just pass through untouched: Some were absorbed into the cells that make up the placenta and the baby's blood vessels. The particles also disrupted levels of hormones such as etiocholanolone and estrogen, which are essential for the mother's health and the baby's development.

Plastics, made from petroleum-derived synthetic or semisynthetic polymers and a cocktail of chemical additives that make them hard, flexible, durable or transparent, have become so pervasive that they now contaminate even the most remote environments. As a result, human exposure to microplastics is inevitable. These tiny plastic particles have been detected in everyday foods and drinks, including salt, seafood, beer and tea, and, in some parts of the world, even in the air.

Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

How your conscious and unconscious mind interact
Most brain activity, including autonomic regulation, implicit memory, and rapid affective processing, occurs without awareness but can influence decisions. Conscious processing is more effortful and may become important during novelty or uncertainty. Theories including global workspace and predictive-processing models describe consciousness as integrating or updating information, but remain debated.

Comment by Dr. Krishna Kumari Challa on Tuesday

Hot weather can make pain worse. Here's why
Higher temperatures, particularly ≥32°C, are associated with increased reports of generalized physical pain, especially among middle-aged and lower-income adults. Dehydration, inflammation, blood-pressure changes, stress, disrupted sleep, and reduced activity may amplify pain. Heat-related pain can impair cognition and productivity and may impose substantial economic costs.

original article.

Comment by Dr. Krishna Kumari Challa on Tuesday

To correct these misperceptions, the research team tested several interventions. In particular, they assessed the effect of simply providing a list of high-impact actions on participants' estimates of greenhouse gas emissions.

They also examined whether participants could improve their estimates by relying on two indicators: the behavioural cost of an action (the more effort, time or financial resources it requires, the more likely it is to have a high impact) and its social prevalence (the rarer it is within the population, e.g., the U.S., the greater its potential to reduce carbon emissions tends to be).
The challenge is therefore to tailor awareness campaigns to different population profiles—which still need to be defined—in order to better correct these biases and encourage the adoption of climate actions and support for policies that are most effective in reducing greenhouse gas emissions.

The results show that the effectiveness of these interventions varies considerably from one individual to another, particularly depending on their ability to use behavioural cost or social prevalence as a cue of an action's actual impact.

Mario Herberz et al, Psychological barriers to improving carbon competence, Nature Sustainability (2026). DOI: 10.1038/s41893-026-01900-0

Part 2

Comment by Dr. Krishna Kumari Challa on Tuesday

We overestimate the positive impact of our actions on the climate

Why is recycling waste or switching off the lights sometimes perceived as more effective for the climate than giving up air travel? A team from the University of Geneva (UNIGE) surveyed nearly 3,000 people and identified key psychological mechanisms underlying these misperceptions. Their findings pave the way for more effective communication strategies that encourage behaviors with the greatest potential to reduce greenhouse gas emissions. The study is published in Nature Sustainability.

Carbon competence refers to the ability to accurately assess the impact of different individual actions on greenhouse gas (GHG) emissions. A high level of carbon competence enables people to identify the most effective ways to reduce emissions, both individually and collectively, thereby contributing to climate change mitigation. Yet several studies show that carbon competence remains limited across the general population, including among people who are highly concerned about environmental issues.

As a result, people tend to overestimate the climate impact of relatively modest actions, such as recycling or printing double-sided. While these behaviors are beneficial, their effect on greenhouse gas emissions remains limited. By contrast, people often underestimate the impact of far more effective actions, such as giving up air travel or reducing car use.

Based on a sample of nearly 3,000 participants, a team from UNIGE examined the psychological barriers that explain these misperceptions. The team also tested the effectiveness of three measures designed to improve carbon competence.

They selected 32 individual actions, ranging from low-impact behaviours to those with much greater environmental benefits. They then analyzed how participants estimated the positive impact of these actions when adopted by an average person.

Among the 32 actions studied, the most overestimated low-impact behaviors are, in order: recycling, using recycled materials, purchasing more energy-efficient household appliances, improving home insulation and teleworking. By contrast, the most underestimated high-impact behaviors include giving up air travel, living without a car, switching to an electric vehicle, avoiding long-haul flights and purchasing renewable electricity.

According to the research team, this gap in carbon competence can be explained by two psychological biases: the "availability heuristic," a mental shortcut whereby people judge an action as more effective if it easily comes to mind, and "motivated reasoning," which serves to preserve a positive self-image. "In the first case, the more an action is present in the media or discussed at school, the more easily it comes to mind, and the more likely people are to consider it effective.

In the case of motivated reasoning, individuals tend to believe that the actions they already engage in are more effective because this perception allows them to preserve a positive self-image.

The researchers also show that individuals with strong pro-environmental values tend to be overly optimistic and to overestimate the impact of environmental actions in general. By contrast, those with a stronger capacity to handle numbers tend to provide more accurate estimates and are less influenced by these biases.

Part 1

Comment by Dr. Krishna Kumari Challa on Sunday

Fewer retractions with open peer-review

Papers with open peer-review reports are less likely to be retracted, says a preprint study. Researchers analysed more than 116,000 papers in Public Library of Science (PLOS) journals and found that among the 40% that opted for publicly available peer-review reports, there were around 100 retractions. There were more than 300 in the closed-review group. It might be that researchers who are confident in their work and who broadly embrace open-science practices are more likely to choose open peer review. In that case, the choice itself could serve as an indicator of article quality.

https://osf.io/preprints/metaarxiv/2b7z5_v1

https://www.nature.com/articles/d41586-026-02282-1?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on Sunday

New technique pinpoints human DNA inherited from 'ghost' ancestors

Researchers have identified regions of DNA that humans inherited from two unknown ancestors as a result of long-ago interbreeding among modern humans and at least four other archaic human relatives.

While previous research found hints that modern humans had interbred with ancient hominins in addition to now-extinct Neanderthals and Denisovans, the current study pinpoints areas of the genome inherited from these unknown ancestors and establishes a timeline. This was possible using a new technique the researchers developed that leverages hundreds of genomes from modern-day humans to find ancient genealogical relationships.
One of the unknown ancestors, which the researchers refer to as a ghost ancestor, interbred with modern humans in Africa prior to 50,000 years ago, before the most recent migration of Homo sapiens out of Africa into Europe and Asia. These genes comprise around 1% of the genomes of modern humans, comparable to the amount of Neanderthal DNA in the human genome. That unknown hominin lineage split from the modern human lineage around the same time that Neanderthals and Denisovans diverged, about 800,000 years ago, though it interbred with modern humans earlier.

A genealogical method (TRACE) applied to modern human genomes identifies ~2% archaic DNA from two unknown hominin lineages. A “ghost” lineage, diverging ~800,000 years ago, contributed ~0.5–1% of DNA to all humans via gene flow in Africa >50,000 years ago. A “super-archaic” lineage (~1.8 million years old) introgressed into Denisovans, then indirectly into modern humans.

Yulin Zhang et al, Recovering signatures of archaic hominin introgression using ancestral recombination graphs, Science (2026). DOI: 10.1126/science.aef8874. www.science.org/doi/10.1126/science.aef8874

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