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Comment by Dr. Krishna Kumari Challa 4 hours ago

Astronauts found to process some tasks slower in space, but no signs of permanent cognitive decline

A stay in space exerts extreme pressures on the human body. Astronauts' bodies and brains are impacted by radiation, altered gravity, challenging working conditions, and sleep loss—all of which could compromise cognitive functioning. At the same time, they are required to perform complex tasks, and minor mistakes can have devastating consequences.

Working with 25 astronauts who spent an average of six months on the International Space Station (ISS), researchers  have examined changes in a wide range of cognitive performance domains. This dataset makes up the largest sample of cognitive performance data from professional astronauts published to date.

The research shows that there is no evidence of any significant cognitive impairment or neurodegenerative decline in astronauts spending six months on the ISS. Living and working in space was not associated with widespread cognitive impairment that would be suggestive of significant brain damage.

The results showed that responses to tasks assessing processing speed, working memory, and attention were slower than on Earth, but they were no less accurate. These changes, however, did not persist equally long.

Slowed performance on attention, for example, was only observed early during the mission, while slowed performance on processing speed did not return to baseline levels until after the mission ended and the crew were back on Earth.

Overall, astronauts' cognitive performance was stable, and the researchers did not find evidence that would suggest damage to the central nervous system during a six-month space mission.

Cognitive Performance in ISS Astronauts on 6-month Low Earth Orbit Missions, Frontiers in Physiology (2024). DOI: 10.3389/fphys.2024.1451269

Comment by Dr. Krishna Kumari Challa 5 hours ago

These networks shared a common feature: Each molecular network had two forms of "memory" storage that captured information learned from the environment. One memory decayed much faster than the other -- a form of memory loss necessary for habituation, the researchers noted. This finding suggests that single cells process and remember information over different time spans.

Studying habituation in single cells could help propel understanding of how learning in general works, the researchers said. The findings also cast the humble single-cell creatures in a new, more tantalizing light: They are not merely molecular machines packed in microscopic bodies, but they are also agents that can learn.

Practical applications of this work:

One daring idea would be to apply the concept of habituation to the relationship between cancer and immunity.

Tumors are notoriously good evaders of immune surveillance because they trick immune cells into viewing them as innocent bystanders. In other words, the immune cells responsible for recognizing cancer may get somehow habituated to the presence of a cancer cell -- the immune cell gets used to the stimulus and no longer responds to it.

If we knew how these false perceptions get encoded in immune cells, we may be able to re-engineer them so that immune cells begin to perceive their environments correctly, the tumor becomes visible as malign, and they get to work.

Lina Eckert, Maria Sol Vidal-Saez, Ziyuan Zhao, Jordi Garcia-Ojalvo, Rosa Martinez-Corral, Jeremy Gunawardena. Biochemically plausible models of habituation for single-cell learning. Current Biology, 2024; DOI: 10.1016/j.cub.2024.10.041

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Comment by Dr. Krishna Kumari Challa 5 hours ago

Research reveals even single-cell organisms exhibit habituation, a simple form of learning

Up until recently, habituation -- a simple form of learning -- was deemed the exclusive domain of complex organisms with brains and nervous systems, such as worms, insects, birds, and mammals. But a new study offers compelling evidence that even tiny single-cell creatures such as ciliates and amoebae, as well as the cells in our own bodies, could exhibit habituation akin to that seen in more complex organisms with brains.

A dog learns to sit on command, a person hears and eventually tunes out the hum of a washing machine while reading … The capacity to learn and adapt is central to evolution and, indeed, survival.

Habituation involves the lessening response to a stimulus after repeated exposure. Think of the need for a third espresso to maintain the same level of concentration you once achieved with a single shot.

Up until recently, habituation -- a simple form of learning -- was deemed the exclusive domain of complex organisms with brains and nervous systems, such as worms, insects, birds, and mammals.

But a new study, published Nov. 19 in Current Biology, offers compelling evidence that even tiny single-cell creatures such as ciliates and amoebae, as well as the cells in our own bodies, could exhibit habituation akin to that seen in more complex organisms with brains.

This finding opens up an exciting new mystery for us: How do cells without brains manage something so complex?

The results add to a small but growing body of work on this subject. Earlier work led by Gunawardena found that a single-cell ciliate showed avoidance behavior, not unlike the actions observed in animals that encounter unpleasant stimuli.

Instead of studying cells in a lab dish, the scientists used advanced computer modeling to analyze how molecular networks inside ciliate and mammalian cells respond to different patterns of stimulation. They found four networks that exhibit hallmarks of habituation present in animal brains.

Part1

Comment by Dr. Krishna Kumari Challa 5 hours ago

Above a certain cell density, synNotch exerted a weaker effect and didn't produce the same patterns. Further complicating matters, cell density constantly shifted as cells proliferated at ever changing rates—interacting in complex ways with the synNotch genetic circuit.

The scientists then built a computational model that could predict and clarify this complex and dynamic cell behaviour. It helped guide them to think about how the cell density, proliferation rate, signaling, and all these different things conspire.

Guided by the computational model, the scientists were able to use cell density to generate a variety of predictable fluorescent patterns that developed over specific timeframes.

To understand how cell density was exerting these effects, the scientists conducted a series of experiments that yielded a surprising discovery. Greater cell density induces stress that leads to a quicker breakdown of not only synNotch in particular, but also cell surface sensors in general.

This means that cell density is a broadly applicable tool for guiding both engineered and naturally occurring cells to build a vast array of structures, tissues, and organs.

Nature has relied on cell density in conjunction with genetic circuits to generate the remarkable diversity of multicellular structures, tissues, and organs.

Now we can co-opt this same strategy to advance our efforts to build synthetic multicellular structures—and eventually tissues and organs—for regenerative medicine, say the scientists.

Nature Communications (2024). DOI: 10.1038/s41467-024-53078-8

Part 2

Comment by Dr. Krishna Kumari Challa 5 hours ago

By exerting 'crowd control' over mouse cells, scientists make progress towards engineering tissues
Genes aren't the sole driver instructing cells to build multicellular structures, tissues, and organs. In a paper published in Nature Communications, scientists characterize the influence of another important developmental driver: cell density, or how loosely or tightly cells are packed into a given space.

In both computational models and laboratory experiments, the team of scientists used cell density as an effective tool for controlling how mouse cells pattern themselves into complex structures.

This paper represents progress towards their big picture goal of engineering synthetic tissues. Synthetic tissues could have endless medical applications, ranging from testing potential drugs or therapies to providing grafts or transplants for patients.

The study used two types of mouse cells—connective tissue cells and stem cells—engineered to carry a synthetic cellular communication system or "genetic circuit. This circuit is based on something they developed called "synNotch," which is a protein that scientists genetically engineer into a cell to serve as a "sensor."

Located on a cell's surface, this protein-based sensor recognizes an external signal that triggers the cell to respond—usually by turning on a user-defined gene.

For this particular series of experiments, the scientists used synNotch to turn on a circuit that includes green fluorescence and a way to propagate the signal further—although it could be used to turn on any gene. The fluorescence made it easy to observe cells as they formed patterns. For example, in a field of cells, scientists could create a pattern of green fluorescent rings emanating from a central point.

While conducting these experiments, the scientists noticed that genetically identical cells did not always produce the same patterns.

So that was puzzling at the beginning. When the researchers looked at it more carefully, they started seeing that there was a gradient of cell density that seemed to correlate with differences in patterning.

Part 1

Comment by Dr. Krishna Kumari Challa 5 hours ago

High exposure to everyday chemicals linked to asthma risk in children

A new study by researchers at Kumamoto University sheds light on a potential link between exposure to certain everyday chemicals during pregnancy and the development of asthma in children. The study analyzed data from over 3,500 mother-child pairs as part of the Japan Environment and Children's Study (JECS), a large-scale nationwide research project.

researchers measured 24 types of phenols in urine samples collected from pregnant women. They then tracked the health of their children until the age of four.

The study is published in the journal Environmental Pollution.

High levels of butylparaben, a chemical commonly used in personal care products like lotions and shampoos, during early pregnanacy were associated with a 1.54-fold increase in the odds of asthma development in children (Odds Ratio: 1.54).

Exposure to 4-nonylphenol, a chemical found in some cleaning products and plastics, showed a striking gender-specific effect. Boys born to mothers exposed to this chemical had 2.09 times higher odds of developing asthma, while no such association was observed in girls.

Phenols, including parabens and alkylphenols, are widely used in consumer products for their preservative and antimicrobial properties. While their use is considered safe in small amounts, their potential as endocrine disruptors raises concerns about long-term health effects, such as the recent increase in allergenic diseases such as asthma, particularly during sensitive periods like pregnancy.

The findings highlight the importance of understanding how everyday chemical exposures might contribute to respiratory and allergic conditions in children.

Shohei Kuraoka et al, Association of phenol exposure during pregnancy and asthma development in children: The Japan Environment and Children's study, Environmental Pollution (2024). DOI: 10.1016/j.envpol.2024.124801

Comment by Dr. Krishna Kumari Challa 5 hours ago

Researchers uncover how blood pressure drugs harm kidneys

Commonly prescribed drugs used to treat high blood pressure have been shown to, over time, wreck the kidneys' ability to filter and purify blood. How does this happen?

Researchers found that the drugs essentially rewire the kidneys to do something other than the important work of filtering blood. The kidneys start producing more of a hormone called renin; nerve endings grow excessively; cells lining the kidneys' tiny blood vessels get too large; scars form and spread; and inflammation sets in, which "can take a terrible toll on the kidney.

The result, outlined in the researchers' paper in the journal Circulation Research, is a "silent but serious" vascular disease where the kidneys become zombie-like, changing into something unwanted and unwelcome while abandoning their critical duties.

Now that they know the cause, researchers say the next step is to figure out how to use the effective blood pressure drugs known as renin-angiotensin system inhibitors—often called RAS inhibitors—while stopping the kidney-damaging effects.

RAS inhibitors, which include the generics enalapril, lisinopril, ramipril and others, are commonly prescribed when a patient is first diagnosed with high BP.

The drugs work by relaxing blood vessels and allowing blood to flow more freely. The medicines are widely used and generally considered safe, researchers say, but are not without risk. Doctors have long warned patients that certain blood pressure medications could cause kidney damage, often first noticed as a reduction in the frequency of urination, swelling in the legs or feet, or seizures.

Now that scientists understand what is causing the kidney changes, they can look for ways to stop it.

These findings may open new avenues for the prevention of adverse effects when treating hypertension.

Manako Yamaguchi et al, Transformation of the Kidney into a Pathological Neuro-Immune-Endocrine Organ, Circulation Research (2024). DOI: 10.1161/CIRCRESAHA.124.325305

Comment by Dr. Krishna Kumari Challa on Tuesday

Scientists convert plastics into soaps and detergents

Researchers found  a way to convert certain plastics into soaps, detergents, lubricants, and other products.

  The process has two steps. It first involved using thermolysis, or breaking down a substance—in this case, plastic—by using heat. Plastic placed in a reactor built by the research team and heated to between 650 and 750 degrees Fahrenheit broke down into chemical compounds, leaving a mixture of oil, gas, and residual solids.

The key to this first step was breaking down the polypropylene and polyethylene molecules that make up plastic within a certain carbon range, and Liu and his team were able to accomplish this.

The residual solids left behind were minimal, and the gas could be captured and used as fuel. The oil, though, was the product of the most interest here.

They were also was able to functionalize, or change the chemistry, of the oil into molecules to be converted into soaps, detergents, lubricants, and other products.

These materials are stable. You could use them  to wash your hands and dishes. The researchers have used them to wash their lab glassware in the laboratory.

The process, which took less than a day, led to almost zero air pollution output, thus offering clues to a desperately needed solution to a global problem.

Nuwayo Eric Munyaneza et al, Chain-length-controllable upcycling of polyolefins to sulfate detergents, Nature Sustainability (2024). DOI: 10.1038/s41893-024-01464-x

Comment by Dr. Krishna Kumari Challa on Tuesday

Scientists transform blood into regenerative materials, paving the way for personalized, 3D-printed implants

Scientists have created a new 'biocooperative' material based on blood, which has been shown to successfully repair bones, paving the way for personalized regenerative blood products that could be used as effective therapies to treat injury and disease.

Researchers have used peptide molecules that can guide key processes taking place during the natural healing of tissues to create living materials that enhance tissue regeneration. The research is published in Advanced Materials.

Most of our body tissues have evolved to regenerate ruptures or fractures with remarkable efficacy, as long as these are small in size. This healing process is highly complex. The initial stages rely on liquid blood forming the solid regenerative hematoma (RH), a rich and living microenvironment comprising key cells, macromolecules, and factors that orchestrate regeneration.
The team developed a self-assembling methodology where synthetic peptides are mixed with whole blood taken from the patient to create a material that harnesses key molecules, cells, and mechanisms of the natural healing process. In this way, it was possible to engineer regenerative materials capable of not only mimicking the natural RH, but also enhancing its structural and functional properties.
These materials can be easily assembled, manipulated, and even 3D printed while maintaining normal functions of the natural RH, such as normal platelet behavior, generation of growth factors, and recruitment of relevant cells important for healing. With this method, the team has shown the capacity to successfully repair bone in animal models using the animal's own blood.

Soraya Padilla‐Lopategui et al, Biocooperative Regenerative Materials by Harnessing Blood‐Clotting and Peptide Self‐Assembly, Advanced Materials (2024). DOI: 10.1002/adma.202407156

Comment by Dr. Krishna Kumari Challa on Tuesday

Lemongrass consists of a more floral and earthy aroma, while the other aromas are pungent, spicy or sweet. This difference in profile may explain why lemongrass seemed less intense in the VR setting compared to the microgravity posture.
In an Earth-like setting, eating was often social, but eating in space on long missions can feel quite different.
Pilot studies [published open-access in the journal Science Talks] show that spending 10 minutes in VR can induce feelings of confinement, highlighting VR's effectiveness over other methods such as immersive screens.

"Results indicate that a remote, confined environment such as the ISS and a significant variation in personal sensitivities influence aroma perception, making certain foods smell strange.
Space studies often emphasized microgravity as the main contributing factor to food's different taste, but the team's findings underscored the impact of confined and isolated environments.
This research opens possibilities for personalized meal plans for astronauts and individuals living alone on Earth, showcasing VR's potential to explore variations in eating when stressed.
In the VR setting, participants reporting positive emotions perceived stronger aromas.This link between stress and vinegar may help explain why astronauts like to eat certain foods in microgravity that they don't normally enjoy on Earth.

Food odour perception and affective response in virtual spacecraft and microgravity body posture (1-G) – potential ground-based simulations, Food Research International (2024).

Julia Low et al, Development of a virtual reality spacecraft environment as a ground-based analog for collecting space food sensory data ('Food in Space'), Science Talks (2024). DOI: 10.1016/j.sctalk.2024.100391

Alicia Tran et al, Exploring fundamentals of immersive environment setups on food sensory perception in space contexts, Science Talks (2024). DOI: 10.1016/j.sctalk.2024.100403

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