Comment

Comment by Dr. Krishna Kumari Challa on March 20, 2024 at 9:30am

Rank Country Global biodiversity index Global rank
1. Democratic Republic of Congo 214.43 16th
2. Tanzania 213.10 17th
3. South Africa 207.94 19th
4. Kenya 179.72 23rd
5. Cameroon 172.41 24th
6. Madagascar 162.29 26th
7. Angola 160.67 27th
8. Guinea 153.43 30th
9. Mozambique 144.30 31st
10. Uganda 136.65 33rd

Comment by Dr. Krishna Kumari Challa on March 20, 2024 at 9:21am

In the case of mitochondrial recycling, this works as follows: If sufficient energy is available, a signal is transmitted from the insulin receptor on the cell surface to the mitochondria. Here, PINK1 blueprints are stored as mRNA molecules. When the insulin signal arrives, the blueprints are released by the mitochondria and the cell can produce additional PINK1 protein. This ensures that defective mitochondria are efficiently eliminated. In case of an energy shortage, or if the insulin receptor signal is missing, the blueprints for PINK1 remain tightly bound to the mitochondria.

On the one hand, the tight binding to mitochondria allows the PINK1 blueprints to hitchhike far into the nerve cells' long extensions. On the other hand, it reduces the availability of mRNA molecules for PINK1 production. PINK1 protein levels remain low and mitochondrial recycling is reduced—even though this can lead to the continued operation of damaged power plants.

Interrupted signaling with implications for health and aging

A similar situation can occur when the transmission of signals from the insulin receptor to mitochondria is disturbed due to disease. Defective insulin signaling is a hallmark of diabetes and has also been observed in the brain in connection with Alzheimer's disease.

It is also known that inefficient mitochondrial quality control can contribute to various neurodegenerative diseases.

Insulin signaling regulates Pink1 mRNA localization via modulation of AMPK activity to support PINK1 function in neurons, Nature Metabolism (2024). DOI: 10.1038/s42255-024-01007-w

Part 2

Comment by Dr. Krishna Kumari Challa on March 20, 2024 at 9:19am

In nerve cells, insulin regulates whether mitochondria are shut down or kept running

The hormone insulin controls many cellular processes and adapts them to the body's current energy supply. One of the insulin-regulated processes is the quality control of mitochondria in neurons, scientists have discovered.

When sufficient energy is available in the body, insulin facilitates the elimination of defective mitochondria. When energy is scarce or when the insulin signal is interrupted, mitochondrial recycling is reduced and cells continue to use their old power plants, even potentially damaged ones. The continued operation of faulty mitochondria could affect aging processes and neurological diseases.

Nerve cells place special demands on their energy supply. Due to their extensive branching and their high energy needs, they keep a close watch on their cellular power plants, the mitochondria. The cells have to ensure that there are always sufficient mitochondria available in their long extensions, the axons, where the power plants fuel the cell's communication with its neighboring cells. This is why neurons transport mitochondria even to the cells' most remote locations.

 Earlier research had shown that mitochondria carry along the blueprints of the PINK1 protein on their journey through the neuron.

PINK1 is a key protein that acts when mitochondria need to be removed because they are no longer functioning correctly. 

It can mark mitochondria for recycling and is precisely controlled by the cells." A failure to keep PINK1 in check could lead to a shortage of mitochondria, whereas the continued operation of defective cellular power plants can damage a cell.

Researchers have now uncovered that the hormone insulin is involved in mitochondrial quality control in neurons. Insulin is well-known for its role in regulating a cell's sugar uptake. It also controls many processes inside cells to precisely adjust them to the body's current energy supply.

Part 1

Comment by Dr. Krishna Kumari Challa on March 19, 2024 at 11:50am

Infantile amnesia

People   assume babies’ brains are simply not mature enough to form lasting memories. This is called infantile amnesia.

But scientists found that infantile amnesia seems to affect only certain kinds of memories, particularly the ones known as contextual memories, which involve connecting cues such as the layout of an environment with events that happen there. In humans, the forgotten memories include episodic memories: conscious recollections of where and when a specific event occurred.

 In contrast, young brains can recall other types of memories just fine, including semantic memories of the meanings of words and motor memories of skills such as how to draw a circle. 

Exactly when can the developing brain switch on the ability to form accessible long-term memories?

Data indicates it’s at about 20 months. Children that age who learned to associate a toy with a certain location in each room can remember the information for up to 6 months, whereas younger children only remember it for about 1 month.

The brain actually can create memories before age 3—although perhaps in a different way from adult memories—and those memories may persist into adulthood. But we can’t consciously access them.

Psychologists have found some evidence that early memories may linger, even if we can’t consciously access them.

The human and rodent studies both suggest infantile memories are not gone, only forgotten.

This forgetting probably serves some evolutionary purpose, whether that’s helping young brains learn how to attach the proper importance to events or developing a framework for the memory systems they will use throughout life.

Comment by Dr. Krishna Kumari Challa on March 19, 2024 at 7:25am

The researchers also found that people differed from each other in terms of how much glucose fluctuations impacted their cognitive speed, and some people—including older adults and adults with certain health conditions—were much more impacted by glucose fluctuations than others.

These results demonstrate that people can differ a lot from one another in how their brains are impacted by glucose.

This work  found that minimizing glucose fluctuations in daily life is important for optimizing processing speed, and this is especially true for people who are older or have other diabetes-related health conditions.

One surprise discovery was that participants' peak cognitive performance coincided with glucose levels that were slightly above their normal range, though performance dropped off as glucose levels rose even further.

 Dynamic associations between glucose and ecological momentary cognition in Type 1 Diabetes, npj Digital Medicine (2024). DOI: 10.1038/s41746-024-01036-5 , www.nature.com/articles/s41746-024-01036-5

Part 2

Comment by Dr. Krishna Kumari Challa on March 19, 2024 at 7:23am

Study shows glucose levels affect cognitive performance in people with type 1 diabetes differently

A new study  used advances in digital testing to demonstrate that naturally occurring glucose fluctuations impact cognitive function in people with type 1 diabetes (T1D).

Results of the study, published in npj Digital Medicine, show that cognition was slower in moments when glucose was atypical—that is, considerably higher or lower than someone's usual glucose level. However, some people were more susceptible to the cognitive effects of large glucose fluctuations than others.

In trying to understand how diabetes impacts the brain, this research shows that it is important to consider not only how people are similar, but also how they differ.

T1D is an autoimmune disease characterized by glucose variability. Previous laboratory studies have shown that very low and very high glucose levels impair cognitive function. However, technological limitations made it difficult to study the impact of naturally occurring glucose fluctuations on cognition outside of the laboratory, preventing researchers from obtaining repeated, high-frequency measurements within the same individuals over time. High-frequency measurements are necessary to understand whether glucose fluctuations impact cognition similarly for everyone.

In the new study, researchers used digital glucose sensors and smartphone-based cognitive tests to collect repeated, high-frequency glucose and cognitive data in 200 individuals with T1D. Glucose data were collected every five minutes and cognitive data were collected three times per day for fifteen days.

Collecting glucose and cognitive data unobtrusively, as participants went about their daily lives, allowed researchers to examine the cognitive impact of naturally occurring glucose variability. With many data points from each individual, they were able to use machine learning to test whether the impact of glucose on cognition differed from person to person.

The study showed that cognitive function was impaired when glucose was considerably higher or lower than usual, and this effect was observed for processing speed but not sustained attention. It is possible that processing speed is impacted by short-term, moment-to-moment fluctuations in glucose, whereas sustained attention is impacted by high or low glucose that persists over longer periods of time.

Part 1

Comment by Dr. Krishna Kumari Challa on March 19, 2024 at 7:11am

Two artificial intelligences talk to each other

Performing a new task based solely on verbal or written instructions, and then describing it to others so that they can reproduce it, is a cornerstone of human communication that still resists artificial intelligence (AI).

A team from the University of Geneva (UNIGE) has succeeded in modeling an artificial neural network capable of this cognitive prowess. After learning and performing a series of basic tasks, this AI was able to provide a linguistic description of them to a "sister" AI, which in turn performed them. These promising results, especially for robotics, are  published in Nature Neuroscience.

Performing a new task without prior training, on the sole basis of verbal or written instructions, is a unique human ability. What's more, once we have learned the task, we are able to describe it so that another person can reproduce it. This dual capacity distinguishes us from other species which, to learn a new task, need numerous trials accompanied by positive or negative reinforcement signals, without being able to communicate it to their congeners.

A sub-field of artificial intelligence (AI)—Natural language processing—seeks to recreate this human faculty, with machines that understand and respond to vocal or textual data. This technique is based on artificial neural networks, inspired by our biological neurons and by the way they transmit electrical signals to one another in the brain. However, the neural calculations that would make it possible to achieve the cognitive feat described above are still poorly understood.

Currently, conversational agents using AI are capable of integrating linguistic information to produce text or an image. But, according to researchers, they are not yet capable of translating a verbal or written instruction into a sensorimotor action, and even less explaining it to another artificial intelligence so that it can reproduce it.

The researchers have now succeeded in developing an artificial neuronal model with this dual capacity, albeit with prior training.

This model opens new horizons for understanding the interaction between language and behaviour. It is particularly promising for the robotics sector, where the development of technologies that enable machines to talk to each other.

 Reidar Riveland et al, Natural language instructions induce compositional generalization in networks of neurons, Nature Neuroscience (2024). DOI: 10.1038/s41593-024-01607-5

Comment by Dr. Krishna Kumari Challa on March 18, 2024 at 12:03pm

Plastic World

In more than 200 people undergoing surgery, scientists found that nearly 60 percent of patients had microplastics or even smaller nanoplastics in the plaque build-up in the main neck artery. Those patients were 4.5 times more likely to experience a heart attack, a stroke or death in the approximately three years after the surgery than were those whose arteries were plastic-free.  Microplastics are everywhere. These plastic particles, which range from smaller than a single virus particle to as large as the width of a pencil, have been found in the trillions in oceans and tissues of sea animals, as well in drinking water, rain, air, human tissue and breast milk. Since they don’t break down quickly and cells in the body that manage waste can’t degrade them, microplastics accumulate in organisms. According to conservative estimates, most people ingest between 74,000 and 121,000 microplastic particles every year, likely more. But the effect that all these plastic pieces have on human health is still an area of ongoing research.

Comment by Dr. Krishna Kumari Challa on March 17, 2024 at 11:11am

What Comes After 5G? Developing New Technologies to Enable 6G

Comment by Dr. Krishna Kumari Challa on March 16, 2024 at 10:03am

Plastic chemicals include all chemicals found in plastic, in addition to additives, impurities and chemicals that are used during production.

The advice of researchers:

The researchers have formulated four points that they believe decision-makers must address:

• Regulate the use of problematic substances in plastics.
• Create more transparency around which chemicals are used in plastic production.
• Make plastics less complicated so we don't have to deal with so many chemicals.
• Increase impact and capacity to make it easier for authorities, industry and researchers to work together to make better plastics.

The report will play a crucial role in tackling the problem of plastic pollution.

Martin Wagner et al, State of the science on plastic chemicals - Identifying and addressing chemicals and polymers of concern, Zenodo (2024). DOI: 10.5281/zenodo.10701706

Part 2

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