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Comment by Dr. Krishna Kumari Challa on May 23, 2022 at 6:56am

Male pheromones improve health of females' eggs

Male pheromones just might be the fountain of youth for aging female animals’ eggs, according to a new study.

In the new study, researchers used the tiny transparent roundworm C. elegans, a well-established model organism commonly used in biology research. Exposure of female roundworms to male pheromones slowed down the aging of the females’ egg cells, resulting in healthier offspring.

Not only did the exposure decrease embryonic death by more than twofold, it also decreased chromosomal abnormalities in surviving offspring by more than twofold. Under the microscope, egg cells also looked younger and healthier, rather than tiny and misshapen, which is common with aging.

To conduct the study, the team aged female roundworms in the presence of a pheromone that is normally produced by male roundworms. The researchers saw that egg quality in females exposed to the pheromone was higher than in control roundworms that did not encounter the pheromone.

Although continuous exposure to male pheromones worked best, even shorter exposure improved overall egg quality. Researchers think this result can be explained by the animals’ “shifting energy budgets.”

Acting outside the body, pheromones are chemicals that animals produce and release to elicit social responses from other members of their species. Pheromones also inform animals about how to budget their finite energy.

When conditions are not conducive to reproduction, female animals will spend resources and energy maintaining their overall body health, including muscles, neurons, intestines and other nonreproductive organs. Sensing male pheromones triggers downstream signaling from the nervous system to the rest of the body, causing the female animals to shift their energy and resources to increasing reproductive health instead. The result? Better eggs but faster decay of the body.

The pheromone tricks the female into sending help to her eggs and shortchanging the rest of her body. It’s not all or nothing, but it’s shifting the balance.

The researchers think this finding potentially could lead to pharmacological interventions that combat infertility issues in humans by improving egg cell quality and delaying the onset of reproductive aging.

Reproductive aging affects everyone. One of the first signs of biological aging is the decreased quality of reproductive cells, which causes reduced fertility, increased incidence of fetal defects including miscarriages, and eventually loss of fertility. By all criteria scientists could think of, male pheromones made the eggs better.

Of course, there are unfortunate trade-offs. When female roundworms neglected the rest of their body to focus their energy on reproductive health, they were more likely to experience early death.

Erin Z. Aprison, Svetlana Dzitoyeva, David Angeles-Albores, Ilya Ruvinsky. A male pheromone that improves the quality of the oogenic germline. Proceedings of the National Academy of Sciences, 2022; 119 (21) DOI: 10.1073/pnas.2015576119

https://news.northwestern.edu/stories/2022/05/male-pheromones-impro....

Comment by Dr. Krishna Kumari Challa on May 23, 2022 at 6:46am

Scientists devise method to prevent deadly hospital infections without antibiotics

 A hospital or medical clinic might be the last place you’d expect to pick up a nasty infection, but that is what happens usually resulting in hundreds of deaths from infection-related complications and billions in direct medical costs.

The biggest culprits, experts say — accounting for two-thirds of these infections — are medical devices like catheters, stents, heart valves and pacemakers, whose surfaces often become covered with harmful bacterial films. But a novel surface treatment developed by a  team of scientists could help improve the safety of these devices and ease the economic burden on the health care system.

The new approach, tested in both laboratory and clinical settings, involves depositing a thin layer of what is known as zwitterionic material on the surface of a device and permanently binding that layer to the underlying substrate using ultraviolet light irradiation. The resulting barrier prevents bacteria and other potentially harmful organic materials from adhering to the surface and causing infection.

In the laboratory, researchers applied the surface treatment to several commonly used medical device materials, then tested the modified materials’ resistance to various types of bacteria, fungi and proteins. They found that the treatment reduced biofilm growth by more than 80% — and in some cases up 93%, depending on the microbial strain.

The modified surfaces exhibited robust resistance against microorganisms and proteins. The surfaces greatly reduced or even prevented biofilm formation.

Brian McVerry, Alexandra Polasko, Ethan Rao, Reihaneh Haghniaz, Dayong Chen, Na He, Pia Ramos, Joel Hayashi, Paige Curson, Chueh‐Yu Wu, Praveen Bandaru, Mackenzie Anderson, Brandon Bui, Aref Sayegh, Shaily Mahendra, Dino Di Carlo, Evgeniy Kreydin, Ali Khademhosseini, Amir Sheikhi, Richard B. Kaner. A Readily Scalable, Clinically Demonstrated, Antibiofouling Zwitterionic Surface Treatment for Implantable Medical Devices. Advanced Materials, 2022; 2200254 DOI: 10.1002/adma.202200254

https://newsroom.ucla.edu/releases/surface-treatment-for-medical-de...

Comment by Dr. Krishna Kumari Challa on May 22, 2022 at 11:27am

Exoskeleton device helps stroke victims regain hand function

Comment by Dr. Krishna Kumari Challa on May 21, 2022 at 1:23pm

However, the pressure of the solar wind seems to play little role in the brightness of said auroras. This suggests that space weather events, such as coronal mass ejections, where masses of charged particles are ejected from the Sun and are associated with higher solar wind pressure, may trigger Martian auroras.

Inside the crustal magnetic field regions, the orientation of the magnetic field and the solar wind seems to play a significant role in the formation of auroras on Mars. At certain orientations, the solar wind seems to be favorable to the magnetic reconnection events or particle acceleration required to produce the ultraviolet glow.

These results, the researchers said, reveal new information on how interactions with the solar wind can generate auroras on a planet stripped of its global magnetic field. This information can be used to help better understand the formation of discrete auroras on very different worlds.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JA030238

Part 2

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Comment by Dr. Krishna Kumari Challa on May 21, 2022 at 1:23pm

Mars Has Auroras Without a Global Magnetic Field

Earth's auroras are a glorious wonder, but our planet isn't the only place in the Solar System where these phenomena can be found. An atmospheric glow, albeit sometimes in invisible wavelengths, has been spotted at every planet except Mercury, and even some moons of Jupiter... and even a comet. But Mars is where it gets interesting. The red planet is famous for its lost global magnetic field, an ingredient that plays a crucial role in the formation of aurora elsewhere.

But that doesn't mean Mars is totally magnetism-free. Regions of localized magnetic fields sprout from some regions of the crust, particularly in the southern hemisphere. New analysis has confirmed that these small, local magnetic fields interact with the solar wind in interesting ways to produce Mars's discrete (or structured) ultraviolet auroras.

The new main finding is that inside the strong crustal field region, the aurora occurrence rate depends mostly on the orientation of the solar wind magnetic field, while outside the strong crustal field region, the occurrence rate depends mostly on the solar wind dynamic pressure.

But Mars's global magnetic field decayed fairly early on in the planet's history, leaving behind only patches of magnetism preserved in magnetized minerals in the crust. Ultraviolet images of Mars at night have revealed that auroras tend to form near these crustal magnetic fields, which makes sense if magnetic field lines are required for particle acceleration.  Outside the crustal magnetic field regions, the dynamic pressure of the solar wind plays a significant role in the detection frequency of auroras.

Part 1

Comment by Dr. Krishna Kumari Challa on May 21, 2022 at 9:59am

New method to kill cyberattacks in less than a second

A new method that could automatically detect and kill cyberattacks on our laptops, computers and smart devices in under a second has been created by researchers.

Using artificial intelligence in a completely novel way, the method has been shown to successfully prevent up to 92 percent of files on a computer from being corrupted, with it taking just 0.3 seconds on average for a piece of malware to be wiped out.

The new approach is based on monitoring and predicting the behavior of malware as opposed to more traditional antivirus approaches that analyze what a piece of malware looks like.

By training computers to run simulations on specific pieces of malware, it is possible to make a very quick prediction in less than a second of how the malware will behave further down the line.

Once a piece of software is flagged as malicious the next stage is to wipe it out, which is where the new research comes into play.

Once a threat is detected, due to the fast-acting nature of some destructive malware, it is vital to have automated actions to support these detections.

Matilda Rhode et al, Real-Time Malware Process Detection and Automated Process Killing, Security and Communication Networks (2021). DOI: 10.1155/2021/8933681

https://techxplore.com/news/2022-05-method-cyberattacks.html?utm_so...

Comment by Dr. Krishna Kumari Challa on May 21, 2022 at 9:51am

How one of the X chromosomes in female embryonic stem cells is silenced

In most mammals, females have two X chromosomes and males have one X and one Y chromosome in each of their cells. To avoid a double dose of X-linked genes in females, one of the Xs is silenced early in the developmental process. This silencing is critical, yet how it happens has been relatively mysterious. Two new  studies reveal more about this silencing process and insights that could improve stem cell research.

Human embryonic stem cells (hESCs) hold enormous promise for research into early development as well as for regenerative medicine for diseases ranging from type 1 diabetes to Parkinson's disease. Yet, biologists working with female hESCs in the lab often run into a phenomenon wherein the normally inactivated X chromosome loses this suppression while growing in a culture dish.

If you can't maintain hESCs exactly as such in culture then you can't use them for any downstream application. Researchers set out to determine why X-inactivation erodes under certain experimental conditions over time.

Their primary suspect was the substance used to grow the cells in culture, called media. Cells are grown in media that supply them with chemical instructions called growth factors. These growth factors signal stem cells to keep dividing. One popular medium, called mTeSR1, appeared to be correlated with the loss of a key regulator of X-inactivation, a non-coding strand of RNA called XIST. Another medium, called Xenofree, did not lead to a loss of X-inactivation.

Researchers looked at the differences in the composition of these two media and identified lithium chloride as being present in mTeSR1 but not in Xenofree.

Lithium chloride is sometimes included in media to promote stem cell proliferation, however, it is known to interfere with many cell-signaling pathways by inhibiting GSK-3 proteins. (Inhibitors of GSK-3 proteins have been used to treat several diseases, and lithium, used to treat bipolar disorder, was one of the first natural GSK-3 inhibitors discovered.)

To confirm lithium chloride as the culprit, they added the compound to the Xenofree medium and saw a loss of X-inactivation.

This study suggests that researchers need to be a little more cautious about the use of GSK-3 inhibitors like lithium. They may not only interfere with X inactivation, but other modes of epigenetic transcriptional regulation across the genome.

 Marissa Cloutier et al, Preventing erosion of X-chromosome inactivation in human embryonic stem cells, Nature Communications (2022). DOI: 10.1038/s41467-022-30259-x

Milan Kumar Samanta et al, Activation of Xist by an evolutionarily conserved function of KDM5C demethylase, Nature Communications (2022). DOI: 10.1038/s41467-022-30352-1

Comment by Dr. Krishna Kumari Challa on May 20, 2022 at 12:58pm

Genetic predictability steadily erodes during evolution, new study shows

A critical goal in genetics and evolution is predicting the effects of mutations that may happen in the future and inferring the effects of those that happened in the past. To make these predictions, scientists generally assume that a mutation's effects tested in the present apply to past and future versions of the same gene.

This assumption turns out to be wrong for most mutations, a new study by University of Chicago scientists shows. By combining cutting-edge techniques in experimental biochemistry and evolutionary reconstruction of ancient proteins, the study directly measured how the effects of every possible mutation in a biologically essential gene changed across 700 million years of evolution. As the gene evolved, the effects of most mutations changed steadily and randomly, often switching from highly detrimental to inconsequential, or vice versa.

This constant drift makes it impossible to reliably predict the effects of most mutations into the future or back into the past. The findings also imply that the potential fate of a mutation during evolution is determined not only by natural selection, but also by the particular set of chance events that happened to unfold during the gene's history. These events determine the effect each mutation has at each timepoint and therefore the probability that it will be incorporated into the gene during evolution.

Yeonwoo Park et al, Epistatic drift causes gradual decay of predictability in protein evolution, Science (2022). DOI: 10.1126/science.abn6895. www.science.org/doi/10.1126/science.abn6895

https://phys.org/news/2022-05-genetic-steadily-erodes-evolution.htm...

Comment by Dr. Krishna Kumari Challa on May 20, 2022 at 11:36am

A Black Hole's Magnetic Reversal

Comment by Dr. Krishna Kumari Challa on May 20, 2022 at 11:29am

Instead of looking at all possible chemical reactions, they identify the few that they might need to look at. They think that most tissues involved in the initiation of cancer are trying to be as homogenous as possible. The rule is a pathway that decreases heterogeneity is always going to be the fastest on the road to tumor formation.

The huge number of possible pathways seems to make narrowing them down an intractable problem. But it turned out that using their chemical intuition and building an effective free-energy landscape helped by allowing them to calculate where in the process a mutation is likely to become fixated in a cell.

The team simplified calculations by focusing initially on pathways involving only two mutations that, when fixed, initiate a tumor. Mechanisms involving more mutations will complicate calculations, but the procedure remains the same.

Hamid Teimouri, Cade Spaulding, Anatoly B. Kolomeisky. Optimal pathways control fixation of multiple mutations during cancer initiation. Biophysical Journal, 2022; DOI: 10.1016/j.bpj.2022.05.011

Part 2

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