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Comment by Dr. Krishna Kumari Challa on August 2, 2023 at 10:12am

Is AI only software? 

AI is about the principles of making machines learn and make intelligent decisions. AI has many subfields under it: Machine Learning, Reinforcement Learning, Computer Vision (very tightly coupled with Machine Learning), Deep Learning, NLP, data representation and semantics, learning theory, Robotics (which is the hardware side of things) which includes things like planning, motion and manipulation...etc.

So its not only about software. AI can be in the form of abstract theory, learning from data to make predictions and intelligent decisions (software) or in robotics (hardware).

Comment by Dr. Krishna Kumari Challa on August 2, 2023 at 10:09am

Chatbots sometimes make things up. Is AI's hallucination problem fixable?

Spend enough time with ChatGPT and other artificial intelligence chatbots and it doesn't take long for them to spout falsehoods. 

Described as hallucination, confabulation or just plain making things up, it's now a problem for every business, organization and high school student trying to get a generative AI system to compose documents and get work done. Some are using it on tasks with the potential for high-stakes consequences, from psychotherapy to researching and writing legal briefs.

According to experts there isn't any model today that doesn't suffer from some hallucination! They're really just sort of designed to predict the next word, and so there will be some rate at which the model does that inaccurately. 

So experts are now trying to make them truthful. But they aren't very sure. Because the problem is inherent in the mismatch between the technology and the proposed use cases.

But still what is wrong with trying to improve the software/hardware? let us cross our fingers and hope for the best.

Source: AP 

Comment by Dr. Krishna Kumari Challa on August 2, 2023 at 9:56am

Early-life lead exposure linked to higher risk of criminal behaviour in adulthood

An evaluation of 17 previously published studies suggests that exposure to lead in the womb or in childhood is associated with an increased risk of engaging in criminal behavior in adulthood. 

Lead exposure can cause a variety of health challenges, such as cardiac issues,kidney damage, immune system dysfunction, reproductive problems, and impaired neurodevelopmental function in children. Research has also uncovered statistical associations between lead exposure and criminal behaviour, both at the level of the entire population and at the level of individual people. However, the findings of individual-level studies have been inconsistent.

To help clarify the existing evidence, researchers conducted a systematic review of studies that address links between individual lead exposure and crime or other antisocial behaviors. Their analysis included 17 studies, which employed a variety of methods for measuring lead exposure—using blood, bones, or teeth—and addressed the effects of exposure at different ages, including in the womb or early childhood, later childhood, and adolescence or adulthood.

The review highlighted a wide range of findings among the studies. For instance, in some cases, no statistical links were found between early childhood lead exposure and later delinquent behavior. One study showed a link between exposure and antisocial behavior, but not arrests. Still, several studies found links between early childhood exposure to lead and later arrests, including drug-related arrests. The authors also used a tool called ROBINS-E to evaluate each study for statistical bias, finding some studies to be more statistically robust than others.

Overall, in light of the known biological effects of lead, this review suggests that an individual exposed to lead in the womb or in early childhood may have a higher risk of engaging in criminal behaviour as an adult.

Policy action to prevent lead exposure is of utmost importance as our research shows an excess risk for criminal behavior in adulthood exists when an individual is exposed to lead in utero or during childhood. Preventing lead exposure is crucial to safeguard public health and promote a safer society for all.

Talayero MJ, The association between lead exposure and crime: A systematic review, PLOS Global Public Health (2023). DOI: 10.1371/journal.pgph.0002177

Comment by Dr. Krishna Kumari Challa on August 1, 2023 at 12:47pm

Mysterious Creatures Feed Microbes to Their Babies in New Scientific First

Caecilian mothers grow a fatty skin layer for their babies to tear off and eat. It offers not only nourishment for their offspring but also microbes, providing a starter kit for their young's own microbiome, new research has discovered.

Caecilians are weird, mysterious creatures. They look sort of like huge worms or small snakes, but they're really limbless amphibians, lesser-known relatives of frogs and salamanders. They lead secretive lives, generally hidden from view in soil or stream beds.

What little we do know about caecilians invites more curiosity. They can be surprisingly doting parents, especially by amphibian standards. In some species, mothers provide the skin meals for their young, who have uniquely adapted baby teeth to help them eat it.

Many animals are known to pass microbes to the next generation through parental care in some way, but this is the first direct evidence of it happening in any amphibian. And of all the amphibian species it could be, the study's authors found this happening in caecilians.

 Even after the period of skin feeding (or maternal dermatophagy) ends, a mother and her babies often stay together, the researchers note, coiling up together as a family.

The study found that bacteria from the environment were the least important source for microbiomes of young caecilians. But all juveniles shared at least some of their skin and gut microbiomes with their mothers, which they obtained via both skin feeding and coiling.

https://animalmicrobiome.biomedcentral.com/articles/10.1186/s42523-...

Comment by Dr. Krishna Kumari Challa on August 1, 2023 at 12:21pm

Worms Revived After 46,000 Years Frozen in Siberian Permafrost

Scientists want to understand how the worms survived in extreme conditions for extraordinarily long periods of time.

The discovery, published  recently in the peer-reviewed journal PLOS Genetics, offers new insight into how the worms, also known as nematodes, can survive in extreme conditions for extraordinarily long periods of time, in this case tens of thousands of years.

In 2018, Anastasia Shatilovich, a scientist from the Institute of Physicochemical and Biological Problems in Soil Science RAS in Russia, thawed two female worms from a fossilized burrow dug by gophers in the Arctic.

The worms, which were buried approximately 130 feet in the permafrost, were revived simply by putting them in water, according to a news release from the Max Planck Institute of Molecular Cell Biology and Genetics in Germany.

Called Panagrolaimus kolymaensis, after the Kolyma River in Russia, where they were found, the worms were sent to Germany for further study. The creatures, which have a life span measured in days, died after reproducing several generations in the lab, researchers said.

Using radiocarbon dating, researchers determined the specimens were frozen between 45,839 and 47,769 years ago, during the late Pleistocene.

The roughly millimeter-long worms were able to resist extreme low temperatures by entering a dormant state called cryptobiosis, a process researchers at the institute have been trying to understand.

No nematodes had been known to achieve such a dormant state for thousands of years at a time, Teymuras Kurzchalia, a professor emeritus at the institute who was involved in the study, said recently.

The major take-home message or summary of this discovery is that it is, in principle, possible to stop life for more or less an indefinite time and then restart it.

Researchers identified key genes in the nematode that allow it to achieve the cryptobiotic state. The same genes were found in a contemporary nematode called Caenorhabditis elegans, which can also achieve cryptobiosis.

This led researchers to understand that they cannot survive without a specific sugar called trehalose. Without this sugar, they just die.

The Siberian permafrost has long offered the scientific community a window into the organisms of the distant past. Ancient viruses, mummified bodies and a suite of microscopic creatures have been resurrected from the ice over the years.

“It is, in principle, possible to stop life for more or less an indefinite time and then restart it.”

Comment by Dr. Krishna Kumari Challa on August 1, 2023 at 11:56am

Such a "slowing down" is typical for phase transitions based on the excitation of bosons. Bosons are particles that "generate" interactions (on which, for example, magnetism is based). Matter, on the other hand, is not made up of bosons but of fermions. Electrons, for example, belong to the fermions.

Phase transitions are based on the fact that particles (or also the phenomena triggered by them) disappear. This means that the magnetism in iron becomes smaller and smaller as fewer atoms are aligned in parallel. Fermions, however, cannot be destroyed due to fundamental laws of nature and therefore cannot disappear. "That's why normally they are never involved in phase transitions."

Electrons can be bound in atoms; they then have a fixed place which they cannot leave. Some electrons in metals, on the other hand, are freely mobile—which is why these metals can also conduct electricity. In certain exotic quantum materials, both varieties of electrons can form a superposition state. This produces what are known as quasiparticles.

They are, in a sense, immobile and mobile at the same time—a feature that is only possible in the quantum world. These quasiparticles—unlike "normal" electrons—can be destroyed during a phase transition. This means that the properties of a continuous phase transition can also be observed there, in particular, critical slowing down. So far, this effect could be observed only indirectly in experiments.

Researchers have now developed a new method, which allows direct identification of the collapse of quasiparticles at a phase transition, in particular the associated critical slowing down.

The result contributes to a better understanding of phase transitions in the quantum world. On the long term, the findings might also be useful for applications in quantum information technology.

Critical slowing down near a magnetic quantum phase transition with fermionic breakdown, Nature Physics (2023). DOI: 10.1038/s41567-023-02156-7. www.nature.com/articles/s41567-023-02156-7

Part 2

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Comment by Dr. Krishna Kumari Challa on August 1, 2023 at 11:54am

When electrons slowly vanish during cooling: Researchers observe an effect unique to the quantum world

Many substances change their properties when they are cooled below a certain critical temperature. Such a phase transition occurs, for example, when water freezes. However, in certain metals there are phase transitions that do not exist in the macrocosm. They arise because of the special laws of quantum mechanics that apply in the realm of nature's smallest building blocks.

It is thought that the concept of electrons as carriers of quantized electric charge no longer applies near these exotic phase transitions. Researchers have now found a way to prove this directly. Their findings allow new insights into the exotic world of quantum physics. The publication has now been released in the journal Nature Physics.

If you cool water below zero degrees Celsius, it solidifies into ice. In the process, it abruptly changes its properties. As ice, for example, it has a much lower density than in a liquid state—which is why icebergs float. In physics, this is referred to as a phase transition. But there are also phase transitions in which characteristic features of a substance change gradually. If, for example, an iron magnet is heated up to 760 degrees Celsius, it loses its attraction to other pieces of metal—it is then no longer ferromagnetic, but paramagnetic. However, this does not happen abruptly, but continuously: The iron atoms behave like tiny magnets.At low temperatures, they are oriented parallel to each other. When heated, they fluctuate more and more around this rest position until they are completely randomly aligned, and the material loses its magnetism completely. So while the metal is being heated, it can be both somewhat ferromagnetic and somewhat paramagnetic.

The phase transition thus takes place gradually, so to speak, until finally all the iron is paramagnetic. Along the way, the transition slows down more and more. This behavior is characteristic of all continuous phase transitions. Physicists call it 'critical slowing down'. The reason is that with continuous transitions, the two phases get energetically closer and closer together.

Part 1

Comment by Dr. Krishna Kumari Challa on August 1, 2023 at 10:29am

New study links brain waves directly to memory

Neurons produce rhythmic patterns of electrical activity in the brain. One of the unsettled questions in the field of neuroscience is what primarily drives these rhythmic signals, called oscillations. Researchers have found that simply remembering events can trigger them, even more so than when people are experiencing the actual event.

The researchers, whose findings are published in the journal Neuron, specifically focused on what are known as theta oscillations, which emerge in the brain's hippocampus region during activities like exploration, navigation and sleep. The hippocampus plays a crucial role in the brain's ability to remember the past. Prior to this study, it was thought that the external environment played a more important role in driving theta oscillations. But this new study found that memory generated in the brain is the main driver of theta activity.

They found that theta oscillations in humans are more prevalent when someone is just remembering things, compared to experiencing events directly.

The results of the study could have implications for treating patients with brain damage and cognitive impairments, including patients who have experienced seizures, stroke and Parkinson's disease. Memory could be used to create stimulations from within the brain and drive theta oscillations, which could potentially lead to improvements in memory over time.

Sarah E. Seger et al, Memory-related processing is the primary driver of human hippocampal theta oscillations, Neuron (2023). DOI: 10.1016/j.neuron.2023.06.015

Comment by Dr. Krishna Kumari Challa on July 31, 2023 at 6:28am

Some might suggest that the nerve cells are activated by fear. Most people are familiar with the phenomenon of "freezing" caused by extreme fear. But that is not the case.

Researchers  have compared this type of motor arrest to motor arrest or freezing caused by fear, and they are not identical. They are very sure that the movement arrest observe here is not related to fear. Instead, they think  it has something to do with attention or alertness, which is seen in certain situations.

The researchers think it is an expression of a focused attention. However, they stress that the study has not revealed if this is indeed the case. It is something that requires more research to demonstrate.

The new study may be able to help us understand some of the mechanisms of Parkinson's disease.

Motor arrest or slow movement is one of the cardinal symptoms of Parkinson's disease. Scientists speculate that these special nerve cells in PPN are over-activated in Parkinson's disease. That would inhibit movement. Therefore, the study, which primarily has focused on the fundamental mechanisms that control movement in the nervous system, may eventually help us to understand the cause of some of the motor symptoms in Parkinson's disease.

Among other things, the researchers used optogenetics to stimulate the nerve cells in the brainstem.

In short, optogenetics is a biological technique that involves genetically modifying specific brain cells to make them more sensitive to light. This means that the cells can be activated by a flash of light.

In the study, the researchers were able to stimulate the specific group of nerve cells  in mice and thus determine the motor function of these cells.

 Haizea Goñi-Erro et al, Pedunculopontine Chx10+ neurons control global motor arrest in mice, Nature Neuroscience (2023). DOI: 10.1038/s41593-023-01396-3

Part 2

Comment by Dr. Krishna Kumari Challa on July 31, 2023 at 6:25am

Nerve cells in the brain can halt all movement in the body—even breathing

When a hunting dog picks up the scent of a deer, it sometimes freezes. On the spot. The same thing can happen to people who need to concentrate on a challenging task.

Now researchers have made a discovery that adds to our knowledge of what happens in the brain when we suddenly stop moving. They have found a group of nerve cells in the midbrain which, when stimulated, stop all movement. Not just walking; all forms of motor activity. They even make the mice stop breathing or breathe more slowly, and the heart rate slow down.

There are various ways to stop movement. What is so special about these nerve cells is that once activated they cause the the movement to be paused or freeze. Just like setting a film on pause. The actors movement suddenly stop on the spot.

When the researchers ended activating the nerve cells, the mice would start the movement exactly where it stopped. Just like when pressing "play" again.

This 'pause-and-play pattern' is very unique; it is unlike anything we have seen before. It does not resemble other forms of movement or motor arrest we or other researchers have studied. There, the movement does not necessarily start where it stopped, but may start over with a new pattern.

The nerve cells stimulated by the researchers are found in the midbrain in an area called the pedunculopontine nucleus (PPN), and they differ from other nerve cells there by expressing a specific molecular marker called Chx10. The PPN is common to all vertebrates including humans. So even though the study was performed in mice, the researchers expect the phenomenon to apply to humans too.

Part 1

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