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Comment by Dr. Krishna Kumari Challa 56 minutes ago

Exoskeleton device helps stroke victims regain hand function

Comment by Dr. Krishna Kumari Challa 23 hours ago

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 23 hours ago

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 yesterday

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 yesterday

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 yesterday

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 Friday

A Black Hole's Magnetic Reversal

Comment by Dr. Krishna Kumari Challa on Friday

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

Comment by Dr. Krishna Kumari Challa on Friday

Chemists skew the odds to prevent cancer

The path to cancer prevention is long and arduous for legions of researchers, but new work by  scientists shows that there may be shortcuts.

They are developing a theoretical framework to explain how cancers caused by more than one genetic mutation can be more easily identified and perhaps stopped.

Essentially, it does so by identifying and ignoring transition pathways that don’t contribute much to the fixation of mutations in a cell that goes on to establish a tumor.

A study in the Biophysical Journal describes their analysis of the effective energy landscapes of cellular transformation pathways implicated in a variety of cancers. The ability to limit the number of pathways to the few most likely to kick-start cancer could help to find ways to halt the process before it ever really starts.

Sometimes cancer is just a probability coming true. These researchers  think they can decrease the probability by looking for low-probability collections of mutations that typically lead to cancer. Depending on the type of cancer, this can range between two mutations and 10.

Calculating the effective energies that dictate interactions in biomolecular systems can predict how they behave. The theory is commonly used to predict how a protein will fold, based on the sequence of its constituent atoms and how they interact.

The research team is applying the same principle to cancer initiation pathways that operate in cells but sometimes carry mutations missed by the body’s safeguards. When two or more of these mutations are fixed in a cell, they are carried forward as the cells divide and tumors grow.

Part 1

By their calculations, the odds favor the most dominant pathways, those that carry mutations forward while expending the least amount of energy

Comment by Dr. Krishna Kumari Challa on Friday

Magnetic resonance makes the invisible visible

A small group of researchers just published in Nature Protocols an advanced NMR (Nuclear Magnetic Resonance) method to monitor fast and complicated biomolecular events such as protein folding.

Protein folding was long considered as one of the great mysteries of modern research. This crucial process during which amino acid chains adopt a 3D structure and functionality takes place within milliseconds. Being this fast, protein folding events could often not be characterized by NMR spectroscopy, which is the standard method for studying molecular structures. Employing hyperpolarized water, researchers have now developed a method that dramatically enhances the signals of the proteins, nucleic acids, and other biomolecules. This renders monitoring of processes such as protein folding possible.

With NMR spectroscopy, researchers can measure the magnetic properties of atoms and thus analyze the atomic structure of molecules in solution. This new method is based on NMR and enables the monitoring of biological processes in real-time. By using hyperpolarized water, the researchers significantly enhanced NMR signals of the investigated samples and therefore boost the method's sensitivity.

With hyperpolarization methods, more precisely dissolution DNP (D-DNP), a signal enhancement of over 10,000-fold is possible. The hyperpolarized water acts as a booster for the NMR signals of a protein during the measurement. The hydrogen nuclei of the hyperpolarized water are exchanged with those of the proteins, thus transferring the signal strength to the latter.

With the new method, the researchers can record an NMR spectrum every 100 milliseconds and use it to track the 3D coordinates of individual amino acids and how they change over time. This allows researchers to monitor processes that occur in milliseconds and distinguish individual atoms.

In their study the authors describe their technique in detail, from hyperpolarization to the transfer of the hyperpolarized water to the NMR spectrometer, to the mixing of the hyperpolarized water with the sample solution, and the NMR measurement.

In addition, they present six examples for method application, including the observation of protein folding or even the interactions of RNA (nucleic acids) and RNA-binding proteins as the basis for gene expressions in the cell. According to the scientists, the new method can be used for specific studies of RNA, DNA and polypeptides, especially when signal enhancement reaches the "magic" number of 1,000-fold.

An NMR spectrometer equipped with a hyperpolarization prototype is a prerequisite for NMR boosted by hyperpolarized water. However, this kind of infrastructure is not common yet.

https://www.nature.com/articles/s41596-022-00693-8

https://www.nature.com/articles/s42004-021-00587-y

https://www.inar.de/magnetic-resonance-makes-the-invisible-visible/

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