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Comment by Dr. Krishna Kumari Challa on October 10, 2023 at 9:16am

Many midbody remnants are reabsorbed by one of the daughter cells that shed them, but those that touch down on a distant surface, like a lunar lander, may instead be absorbed by a third cell. If that cell swallows the midbody, it may mistakenly begin using the enclosed RNA as if it were its own blueprints.

Previous research showed that cancer cells are more likely than stem cells to have ingested a midbody and its potentially fate-altering cargo. Stem cells, which give rise to new cells and are valuable for their pluripotency, spit a lot of midbodies back out, perhaps to maintain their pluripotency.

Future research may be able to harness the power of midbody RNA to deliver drugs to cancer cells or to keep them from dividing.

The researchers identified a gene, called Arc, that is key to loading the midbody and midbody remnant with RNA. Taken up long ago from an ancient virus, Arc also plays a role in the way brain cells make memories.

Sungjin Park et al, The mammalian midbody and midbody remnant are assembly sites for RNA and localized translation, Developmental Cell (2023). DOI: 10.1016/j.devcel.2023.07.009

Part 2

Comment by Dr. Krishna Kumari Challa on October 10, 2023 at 9:14am

Remnant of cell division could be responsible for spreading cancer

Once thought to be the trash can of the cell, a little bubble of cellular stuff called the midbody remnant is actually packing working genetic material with the power to change the fate of other cells—including turning them into cancer.

When one cell divides into two, a process called mitosis, the result is not just the two daughter cells.

One cell divides into three things: two cells and one midbody remnant, a new signaling organelle. The midbody is full of genetic information, RNA, that doesn't have much to do with cell division at all, but likely functions in cell communication.

Researchers  analyzed the contents of midbodies—which form between the daughter cells during division—and tracked the interactions of the midbody remnants set free after cell division. Their results point to the midbody as a vehicle for the spread of cancer throughout the body.

What the researchers found inside midbodies was RNA—which is a kind of working copy of DNA used to produce the proteins that make things happen in cells—and the cellular machinery necessary to turn that RNA into proteins. The RNA in midbodies tends to be blueprints not for the cell division process but for proteins involved in activities that steer a cell's purpose, including pluripotency (the ability to develop into any of the body's many different types of cells) and oncogenesis (the formation of cancerous tumours).

A midbody remnant is very small. It's a micron in size, a millionth of a meter. But it's got everything it needs to sustain that working information from the dividing cell. And it can drift away from the site of mitosis, get into your bloodstream and land on another cell far away.

Part 1

Comment by Dr. Krishna Kumari Challa on October 10, 2023 at 8:55am

For a very long time, evolutionary biologists have tried to figure out what was behind this paradox of stasis idea," the scientists said. "What this study shows is that the answer may not be particularly complicated—we just had to conduct a study in the wild for a long enough time to figure it out."

Stroud, James T. et al, Fluctuating selection maintains distinct species phenotypes in an ecological community in the wild, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2222071120. doi.org/10.1073/pnas.2222071120

Part 3

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Firefighting Fungi
Underneath every mushroom is a sprawling, branching network of rootlike structures called a mycelium. Now researchers have successfully grown these networks into Pop Tart–size sheets that could act as a fire retardant in building materials. Mycelium contains a lot of carbon. When exposed to fire, the sheet briefly burns, releasing water and carbon dioxide into the air, before petering out and leaving behind a black layer of carbon.

Why this is so cool: Unlike asbestos, which is still sometimes added to building materials as a fire retardant, mycelium does not shed noxious compounds when exposed to fire. Mycelium could replace the fire-retardant foam that insulates many commercial buildings, which can produce carbon monoxide and other toxic products when it combusts. Mycelium is also a biological material, and any waste it leaves behind is compostable.

What the experts say: “If the product reaches the end of its life, you can just chuck that mycelium in your garden,” says Everson Kandare an engineer at RMIT University in Melbourne, Australia. “Just toss it in the green beans.”

Comment by Dr. Krishna Kumari Challa on October 10, 2023 at 8:54am

Scientists set up a field study with four different species of Anolis lizards (anoles) on a small island at the Fairchild Tropical Botanic Gardens in Coral Gables, Florida. They measured natural selection in all four lizard species over five consecutive time periods by catching and monitoring the survival of every lizard on the island.

The researchers searched day and night for lizards. Using long fishing poles with tiny lassos at their tips, they gently captured them by their strong necks, placed them in coolers, and documented the exact branch or stump where they found each lizard.

Back in the lab, they measured the lizards' heads, legs, feet, weight, and even the stickiness of their toes. After assigning an identifying number to each lizard and marking them with a tiny tag under the skin, the team released the lizards to the same branches where they'd found them. They went out in the following days and weeks to catch the rest of them.

Every six months for three years, the researchers started the process over again. Catching the same lizards, taking measurements, releasing them, and making notes of which lizards survived and which didn't.

By incorporating data for each time period, they captured the history of every lizard in the community. They then related survival data to the variation in body traits, which allowed him to analyze which body traits were important predictors of survival. Taken together, the analysis painted a picture of how natural selection operated on the community as a whole.

To his surprise, scientists found that the stabilizing form of natural selection—that which maintains a species' same, average features—was extremely rare. In fact, natural selection varied massively through time. Some years, lizards with longer legs would survive better, and other years, lizards with shorter legs fared better. For other times, there was no clear pattern at all.

The most fascinating result is that natural selection was extremely variable through time,"  the scientists said. "We often saw that selection would completely flip in direction from one year to the next. When combined into a long-term pattern, however, all this variation effectively canceled itself out: Species remained remarkably similar across the entire time period."

There had never been such insight into how selection works on a community level, and certainly not at this level of detail.

"Evolution can and does happen—it's this ongoing process, but it doesn't necessarily mean things are constantly changing in the long run," the scientists said. "Now we know that even if animals appear to be staying the same, evolution is still happening."

Understanding evolution doesn't only help us understand the plants and animals around us and how they're distributed across the world," they said. "It also shows us how life sustains itself in a world dominated by humans."

Part 2

Comment by Dr. Krishna Kumari Challa on October 10, 2023 at 8:48am

Study challenges the rules of evolutionary biology

Charles Darwin said that evolution was constantly happening, causing animals to adapt for survival. But many of his contemporaries disagreed. If evolution is always causing things to change, they asked, then how is it that two fossils from the same species, found in the same location, can look identical despite being 50 million years apart in age?

Everything changed in the past 40 years, when an explosion of evolutionary studies proved that evolution can and does occur rapidly—even from one generation to the next. Evolutionary biologists were thrilled, but the findings reinforced the same paradox: If evolution can happen so fast, then why do most species on Earth continue to appear the same for many millions of years?

This is known as the paradox of stasis and researchers set out to investigate it. 

  They conducted a long-term study in a community of lizards, measuring how evolution unfolds in the wild across multiple species. In doing so, he may have found the answer to one of evolution's greatest challenges.

The research was published as the cover story in the Proceedings of the National Academy of Sciences.

Scientists call this a paradox because it doesn't seem to make any sense. The most common explanation is that natural selection  is working to stabilize a species' appearance, with the assumption that an average form will help them survive the best. The problem is, when people do field studies, they almost never find that this kind of 'stabilizing' selection actually exists

Part 1

Comment by Dr. Krishna Kumari Challa on October 10, 2023 at 8:30am

The team tested interactions across a broad panel of 20 human and mouse cancer cell lines, ranging from Jurkat leukemia to metastatic human fibrosarcoma cells, triple-negative breast cancer and glioblastoma brain-tumor-initiating cell lines. Consistent potent cytotoxic activity was observed across the entire panel of cancer cell lines that were evaluated with portimine A. The fully synthetic portimine B was found to be substantially less effective.

Portimine A was identified as a potent inducer of apoptosis in various cancer cell lines, including MC38 cells, a colorectal carcinoma testing model. The apoptosis caused by portimine A had minimal effects on non-cancerous cells and low toxicity in mice.
Specifically, portimine A was found to target the 60S ribosomal export protein NMD3, blocking polysome formation and inhibiting protein translation and was observed to be an effective agent for suppressing tumor growth in vivo.

The exposure time to portimine A was limited by its half-life of around 30 minutes. The short duration still resulted in a significant reduction in tumor growth, indicating a very potent activity and potential therapeutic uses in the future.

Junchen Tang et al, Synthesis of portimines reveals the basis of their anti-cancer activity, Nature (2023). DOI: 10.1038/s41586-023-06535-1

The chemical synthesis and anti-cancer properties of portimines, Nature (2023). DOI: 10.1038/d41586-023-02788-y

Part 2

Comment by Dr. Krishna Kumari Challa on October 10, 2023 at 8:29am

How synthesized plankton molecules inhibit cancer proteins

Researchers have discovered how to harness the toxic power of plankton to manufacture anti-cancer molecules.

In a paper, "Synthesis of portimines reveals the basis of their anti-cancer activity," published in Nature, the team details the steps taken in synthesizing marine toxins, portimine A and portimine B, enabling in-depth investigations into their properties

Dinoflagellate-derived cyclic imine toxins, specifically portimine A and portimine B, are of interest due to their potential anti-cancer therapeutic properties. Previous research has shown the effects of cyclic imine toxins on cancer cells, but the molecular mechanisms underlying the cause of the anti-cancer activity were unknown. Access to these toxins in large quantities is currently hard to come by as the only known producer is a type of tiny marine plankton, Vulcanodinium rugosum. To test the toxin's activity, the researchers first needed to innovate a way to synthesize large enough quantities to work with.

The synthesis began with constructing a minimally-decorated carbon skeleton devoid of most oxygen atoms. The idea was to leverage a macrocycle's innate reactivity to install the correct oxygenation pattern and stereochemistry.

Strategic ring-chain tautomerization events were employed to facilitate the synthesis using ring-closing alkyne metathesis to construct the 14-membered macrocycle in the portimines' skeleton. The innovation represents a scalable and concise synthesis of portimines. With the desired molecules created, the next step was to see how they interacted with cancer cells.

Part 1

Comment by Dr. Krishna Kumari Challa on October 10, 2023 at 8:06am

Digital watermark protections can be easily bypassed

Perhaps the most chilling aspect of AI is its capacity to generate deepfake images.

But recent developments portend a more unsettling trend as digital fakery turns malicious. Not only celebrities and politicians, ordinary citizens are targeted, too. People's faces are appearing in images on social media without their consent. 

Major digital media companies—OpenAI, Alphabet, Amazon, DeepMind—have promised to develop tools to combat disinformation. One key approach is the use of watermarking on AI-generated content.

A paper published Sept. 29 on the preprint server arXiv raises troubling news about the ability to curb such digital abuse.

Researchers ran tests demonstrating easy run-arounds of protective watermarks.

We don't have any reliable watermarking at this point because the researchers broke them all!

The team used a process called diffusion purification, which applies Gaussian noise to a watermark and then removes it. It leaves a distorted watermark that can bypass detection algorithms. The rest of the image is only minimally altered.

They further successfully demonstrated that bad actors with access to black-box watermarking algorithms could foist fake photos with markings that trick detectors into believing they are legitimate.

Better algorithms will certainly come along. As has been the case with viral attacks, the bad guys will always be working to break whatever defenses the good guys come up with, and the cat-and-mouse game will continue.

Mehrdad Saberi et al, Robustness of AI-Image Detectors: Fundamental Limits and Practical Attacks, arXiv (2023). DOI: 10.48550/arxiv.2310.00076

Comment by Dr. Krishna Kumari Challa on October 8, 2023 at 12:38pm

The researchers think that gene mutations in certain individuals means that BPA can't be cleared as well as it needs to be, which means the substance sticks around in the body. That potentially could cause damage in terms of neuron development and operation.

Conditions like ASD and ADHD are thought to be brought on by a combination of genetic and environmental influences, and this new study brings together both of them. However, it's only part of the story – not every child with a neurodevelopmental disorder had problems flushing out BPA, so there are other factors at play, too.

Work is continuing to identify how exactly ASD and ADHD take hold in the body – whether it's in utero before birth for example, or later on in life – as the data isn't enough to show whether BPA exposure causes either disorder.

"There is an extensive body of epidemiological evidence for a relationship between neurodevelopmental disorders and environmental pollutants such as plasticizers," write the researchers.

"How important plasticizer originated neurodevelopmental disorder is in the overall occurrence of these disorders is not known, but it must account for a significant proportion or would not have been so easy to detect in a metabolic study of moderate size such as this study."

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0...

Part 2

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Comment by Dr. Krishna Kumari Challa on October 8, 2023 at 12:38pm

Common Plastic Additive Linked to Autism And ADHD

The number of kids being diagnosed with autism spectrum disorder ( ASD) and attention deficit hyperactivity disorder ( ADHD) has risen sharply in recent decades, and a new study points to the common plastic additive bisphenol A (BPA) as a potential reason why. BPA is used in a lot of plastics and plastic production processes, and can also be found inside food and drink cans. However, previous research has also linked it to health issues involving hormone disruption, including breast cancer and infertility.

In this new study, researchers from Rowan University and Rutgers University in the US looked at three groups of children: 66 with autism, 46 with ADHD, and 37 neurotypical kids. In particular, they analyzed the process of glucuronidation, a chemical process the body uses to clear out toxins within the blood through urine.
The research found that kids with ASD and ADHD couldn't clear out BPA and another similar compound called Diethylhexyl Phthalate (DEHP) with as much efficiency as other kids, potentially leading to longer exposure to their toxic effects.

"Detoxification of these two plasticizers is compromised in children with ASD and ADHD," write the researchers in their published paper. "Consequently, their tissues are more exposed to these two plasticizers."

It was only in the case of BPA that the difference was statistically significant though: the efficiency was reduced by about 11 percent for kids with ASD and 17 percent for kids with ADHD, compared with the control group of children.
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