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Comment by Dr. Krishna Kumari Challa on October 4, 2023 at 12:24pm

When fire & ice combine

Comment by Dr. Krishna Kumari Challa on October 4, 2023 at 12:10pm

Research shows humans can inherit AI biases

New research by psychologists provides evidence that people can inherit artificial intelligence biases (systematic errors in AI outputs) in their decisions.

The astonishing results achieved by AI systems that can, for example, hold a conversation as a human does have given this technology an image of high reliability.

More and more professional fields are implementing AI-based tools to support the decision-making of specialists to minimize errors in their decisions. However, this technology is not without risks due to biases in AI results. We must consider that the data used to train AI models reflects past human decisions. If this data hides patterns of systematic errors, the AI algorithm will learn and reproduce these errors. Indeed, extensive evidence indicates that AI systems do inherit and amplify human biases.

The most relevant finding of this new research is that the opposite effect may also occur: that humans inherit AI biases. That is, not only would AI inherit its biases from human data, but people could also inherit those biases from AI, with the risk of getting trapped in a dangerous loop. 

The most significant finding of the research was that after interaction with the AI system, those volunteers continued to mimic its systematic error when they switched to performing the diagnosis task unaided. In other words, participants who were first assisted by the biased AI replicated its bias in a context without this support, thus showing an inherited bias. This effect was not observed for the participants in the control group, who performed the task unaided from the beginning.

These results show that biased information by an artificial intelligence model can have a perdurable negative impact on human decisions. The finding of an inheritance of AI bias effect points to the need for further psychological and multidisciplinary research on AI-human interaction.

Furthermore, evidence-based regulation is also needed to guarantee fair and ethical AI, considering not only the AI technical features but also the psychological aspects of the AI and human collaboration.

Lucía Vicente et al, Humans inherit artificial intelligence biases, Scientific Reports (2023). DOI: 10.1038/s41598-023-42384-8

Comment by Dr. Krishna Kumari Challa on October 4, 2023 at 12:03pm

Why does it get hot when you rub things together? Unraveling the mystery of dynamic friction at the atomic level

Friction, an everyday phenomenon, has perplexed scientists for centuries. Though extensively researched, our understanding remains fragmented, primarily due to the multifaceted interactions that span across varying scales. Achieving an accurate grasp of the precise contact conditions between objects has been a longstanding challenge, a feat recently made possible through advancements in scanning probe microscopy.

Yet, even with these technological breakthroughs, the intricacies of dynamic friction—the force needed to maintain the movement of a molecule—have remained elusive. While scientists can measure static friction by moving a single molecule on a surface, both the measurement and theoretical understanding of dynamic friction have yet to be fully unveiled. Now, writing in Physical Review Letters and Physical Review B, a collaborative team of scientists report their groundbreaking study that dives deep into this challenge. They meticulously examined the manipulation of a carbon monoxide (CO) molecule on a single-crystal copper surface using an atomic force microscope. Backed by ab initio calculations, their findings shed light on how the CO molecule positions change relative to the microscope tip and surface, as well as the relationship between the motion of the molecule induced by the tip, energy dissipation, and both static and dynamic friction. This research stands out for its unequivocal clarity on the friction process. Not only does it provide fresh insights into a long-studied phenomenon, but it also paves the way for future studies on energy dissipation relaxation processes.

Norio Okabayashi et al, Dynamic Friction Unraveled by Observing an Unexpected Intermediate State in Controlled Molecular Manipulation, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.131.148001

Norio Okabayashi et al, Energy dissipation of a carbon monoxide molecule manipulated using a metallic tip on copper surfaces, Physical Review B (2023). DOI: 10.1103/PhysRevB.108.165401

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Comment by Dr. Krishna Kumari Challa on October 4, 2023 at 11:54am

The goal before the scientists now is  to develop a highly focused method or methods for blocking STING within targeted immune cells, without disrupting its other important functions. If they  can achieve that, they may have a powerful new tool for controlling hyper-inflammation.

Hannah Meibers et al, Effector Memory T cells induce innate inflammation by triggering DNA damage and a non-canonical STING pathway in dendritic cells, Cell Reports (2023). DOI: 10.1016/j.celrep.2023.113180. www.cell.com/cell-reports/full … 2211-1247(23)01192-0

Part 3

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Comment by Dr. Krishna Kumari Challa on October 4, 2023 at 11:54am

The chain reaction appears to start when T_em cells interact with dendritic cells, which serve as the immune system's primary detector of viral and bacterial invasions. These starburst shaped cells carry a large collection of receptors to detect various types of invaders. Once they encounter a harmful visitor, dendritic cells latch on and sound an alarm that instructs the rest of the immune system's machinery to begin producing T cells that are custom designed to eliminate that type of invader.

When the immune system wins the battle, most of the custom T cells stand down. But a few guards linger in the blood and other body tissues to be ready to "effect" a rapid response should the same type on infection occur again. Hence the name effector memory T cells.

However, the research team discovered that ongoing encounters with T_em cells, such as those occurring when people have autoimmunity or live in a state of chronic inflammation, actually cause DNA strands within dendritic cells to break. This, in turn, prompts a DNA repair pathway that rapidly generates large numbers of inflammatory cytokines, including IL-1b, IL-6 and IL-12.

This flood, or storm, of cytokines causes the tissue damage that occurs in autoinflammatory diseases including type 1 diabetes, multiple sclerosis, rheumatoid arthritis, and inflammatory bowel diseases like Crohn's disease. For some people with these conditions, ongoing inflammation also increases their risk of developing cancer.

Scientists worked for the last 10 years to examine the genetic activity and cell-to-cell communications occurring behind this process. 

The team found a surprising clue when examining the transcriptional profile of dendritic cells following their interaction with T_em cells. Specifically, they detected upregulation of expression of Tmem173, which encodes for stimulator of interferon genes (STING). The STING pathway has been described in previous research as being important to detect viral infections. But when T_em cells harm dendritic cells, the STING pathway does not follow the same route that it typically does when directly responding to viral infections.

In this situation, STING teams up with the gene TRAF6 and the transcription factor NFkB to form an "axis" of activity that drives runaway production of innate inflammatory cytokines.

The researchers further reasoned that if they could prevent STING and TRAF6 from working together, they could cut off the inflammation chain reaction at an early stage. In mice gene-edited to lack the STING pathway, that's exactly what they found. When treated with a drug known to induce an intense T cell-mediated inflammatory response, these mice did not produce a flood of innate cytokines.

The mouse study involved a whole-body elimination of STING. Attempting the same in humans would not be advisable because STING is used by a number of cell types outside the immune system in necessary ways.

Part 2

Comment by Dr. Krishna Kumari Challa on October 4, 2023 at 11:49am

Science trying to take the STING out of runaway inflammation

Cytokine storm: Everybody came to know about it during the covid-19 pandemic.  But once this dangerous form of infection-triggered runaway inflammation started claiming lives by the thousands, a legion of scientists jumped into the hunt for ways to calm these storms.

Now, a study led by immunobiology experts at Cincinnati Children's, offers important new details on how two elements of our body's immune system clash with each other to prompt a chain of reactions that can release deadly floods of cell-killing, organ-damaging cytokines. Details were published Oct. 3, 2023, in the journal Cell Reports.

These findings have implications for both autoimmunity as well as cancer. Researchers have discovered an independent cell signaling pathway that allows a type of immune cell called an effector memory T cell (T_em) to become a critical driver of innate cytokine storms.

With a pathway defined, next steps include confirming whether medications that target key points along the pathway can disrupt the inflammation cycle before it becomes uncontrollable.

Part 1

Comment by Dr. Krishna Kumari Challa on October 4, 2023 at 11:38am

Atmospheric microplastic transport predominantly derived from oceans, study finds

Microplastics in our natural environments are of increasing concern as these tiny particles (<5mm diameter) pollute ecosystems, posing issues to the well-being of animals and humans alike. There are two principal categories of microplastics: primary particles are manufactured for their size and originate from consumer products, such as the microbeads used in cosmetics, while secondary microplastics occur due to the breakdown of larger materials, such as plastic water bottles and matter from industrial waste.

This breakdown occurs due to ultraviolet radiation from the sun causing plastic to become brittle and thus susceptible to the erosive action of waves in particular to shear off flakes into the surrounding environment.

Their longevity during decomposition, taking upwards of 500 years to complete in a landfill, is a critical factor of their detrimental impact on habitats. Marine animals ingest microplastics suspended in the ocean, and microplastics mixed with the sand on our beaches is barely noticeable. Research has discovered microplastics in the smallest plankton all the way through to filter feeding giants of the sea—whales.

But it is not just the ocean that transports these tiny particles across the globe. Atmospheric wind regimes can carry microplastics vast distances, and their shape has a critical impact on airborne retention before deposition.

New research published in Nature Geoscience considers a theory-based model to determine the settling velocity (the point at which a particle stops being suspended in air and settles due to gravity) of microplastics of various sizes and shapes (up to 100μm long and down to 2μm wide), as compared to previous research that has assumed spherical microplastics. The effect of air turbulence on settling velocity was also factored to determine long distance transport.

 Shuolin Xiao et al, Long-distance atmospheric transport of microplastic fibres influenced by their shapes, Nature Geoscience (2023). DOI: 10.1038/s41561-023-01264-6

Comment by Dr. Krishna Kumari Challa on October 4, 2023 at 11:33am

Nobel Prize in physics for split-second glimpse of superfast spinning world of electrons

Three scientists won the Nobel Prize in physics on Tuesday for giving us the first split-second glimpse into the superfast world of spinning electrons, a field that could one day lead to better electronics or disease diagnoses.

The award went to French-Swedish physicist Anne L'Huillier, French scientist Pierre Agostini and Hungarian-born Ferenc Krausz for their work with the tiny part of each atom that races around the center and is fundamental to virtually everything: chemistry, physics, our bodies and our gadgets.

Electrons move so fast that they have been out of reach of human efforts to isolate them, but by looking at the tiniest fraction of a second possible, scientists now have a "blurry" glimpse of them and that opens up whole new sciences. 

The electrons are very fast, and the electrons are really the workforce in everywhere. Once you can control and understand electrons, you have taken a very big step forward.

The scientists, who worked separately, used ever-quicker laser pulses to catch the atomic action that happened at such dizzying speeds—one quintillionth of a second, known as an attosecond.

www.nobelprize.org/uploads/202 … physicsprize2023.pdf

Comment by Dr. Krishna Kumari Challa on October 3, 2023 at 11:35am

How muscles change during endurance training

Comment by Dr. Krishna Kumari Challa on October 3, 2023 at 10:45am

The very first beat: How a heart starts to pulse

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