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Comment by Dr. Krishna Kumari Challa on March 13, 2024 at 9:15am

False GPS signal surge makes life hard for pilots

False GPS signals that deceive on-board plane systems and complicate the work of airline pilots are surging near conflict zones.

A ground collision alert sounds in the cockpit, for instance, even though the plane is flying at high altitude—a phenomenon affecting several regions and apparently of military origin.

This includes the vicinity of Ukraine following the Russian invasion two years ago, the eastern Mediterranean and the air corridor running above Iraq, according to pilots and officials.

Disruptions which were previously limited to jamming preventing access to signals from geolocation satellites are now also taking a more dangerous form making it difficult to counter spoofing.

This sees a plane receive false coordinates, times and altitudes.

By comparing this data to the geographical maps in its memory banks, its systems can conclude there is imminent danger ahead. There were some untimely alarms ordering people to pull back as far as possible on the stick and apply full power to avoid an obstacle, while the plane was in cruise... and in any case no mountain reaches so high.

The problem  is that this adulterated information enters the navigation system and can cause false alerts hours afterwards as the flight nears its destination.

At first, crews quickly see that it is a false alarm. But as it is an alarm warning of immediate danger, control towers ask the crews to still carry out the emergency maneuver, to make a return and an analysis. If the problem occurs a second time and the analysis has not revealed any danger, then the only way is to turn off this alarm, knowing other systems remain active to detect possible risk.

Since the start of the war in Ukraine, the European Union Aviation Safety Agency (EASA) has been warning that GNSS signal disruptions have intensified, affecting relatively remote regions beyond the conflict zone such as Finland and the Mediterranean.

In certain cases, this can lead to a modified trajectory or even a changed destination as it was impossible to carry out a landing in secure conditions, the EASA says.

Source: AFP and other news agencies

Comment by Dr. Krishna Kumari Challa on March 13, 2024 at 7:18am

For people who speak many languages, there's something special about their native tongue

A new study of people who speak many languages has found that there is something special about how the brain processes their native language.

In the brains of these polyglots—people who speak five or more languages ( I am one of them too!)—the same language regions light up when they listen to any of the languages that they speak. In general, this network responds more strongly to languages in which the speaker is more proficient, with one notable exception: the speaker's native language. When listening to one's native language, language network activity drops off significantly.

The findings suggest there is something unique about the first language one acquires, which allows the brain to process it with minimal effort, the researchers say.

Something makes it a little bit easier to process—maybe it's that you've spent more time using that language—and you get a dip in activity for the native language compared to other languages that you speak proficiently.

The brain's language processing network, located primarily in the left hemisphere, includes regions in the frontal and temporal lobes. In a 2021 study, researchers found that in the brains of polyglots, the language network was less active when listening to their native language than the language networks of people who speak only one language.

In the new study, the researchers wanted to expand on that finding and explore what happens in the brains of polyglots as they listen to languages in which they have varying levels of proficiency. Studying polyglots can help researchers learn more about the functions of the language network, and how languages learned later in life might be represented differently than a native language or languages.

With polyglots, you can do all of the comparisons within one person. You have languages that vary along a continuum, and you can try to see how the brain modulates responses as a function of proficiency.

Saima Malik-Moraleda et al, Functional characterization of the language network of polyglots and hyperpolyglots with precision fMRI, Cerebral Cortex (2024). DOI: 10.1093/cercor/bhae049

Comment by Dr. Krishna Kumari Challa on March 10, 2024 at 12:49pm

A look inside the Harvard Herbaria

Comment by Dr. Krishna Kumari Challa on March 9, 2024 at 12:00pm

Listen to a star ‘twinkle’

Comment by Dr. Krishna Kumari Challa on March 9, 2024 at 11:08am

Australia's Great Barrier Reef in grip of 'mass bleaching event'

A "mass bleaching event" is unfolding on Australia's famed Great Barrier Reef, authorities said recently, as warming seas threaten the spectacular home to thousands of marine species.

Often dubbed the world's largest living structure, the Great Barrier Reef is a 2,300 kilometre (1,400 mile) expanse of tropical corals that house a stunning array of biodiversity.
But repeated mass bleaching events have threatened to rob the tourist drawcard of its wonder, turning banks of once-vibrant corals into a sickly shade of white.

"We know the biggest threat to coral reefs worldwide is climate change. The Great Barrier Reef is no exception.
The damaging mass bleaching event—the seventh since 1998—was confirmed by government scientists following aerial surveys of 300 shallow reefs.

The Australian Reef Authority said it would now need to conduct further surveys to assess the severity and extent of bleaching.

Coral bleaching occurs when underwater temperatures are more than 1 degree warmer than the long-term average.

As corals come under heat stress, they expel algae living within their tissues—draining them of their vibrant colours.
Ocean temperatures along the Great Barrier Reef have approached record levels in the past few weeks, according to official monitoring.
This bleaching event is unfolding in an area where corals have not been previously exposed to these extreme temperatures.
Undoubtedly climate change was "putting tremendous pressure" on the Great Barrier Reef.
The reef is no longer capable of recovering to the mix of coral species and the sizes of corals that were there 20 years ago, according to scientists.
The fate of the reef has been a recurrent source of tension between the Australian government and the United Nations' World Heritage Committee.

The World Heritage Committee has threatened to put the reef on a list of "in danger" global heritage sites, a move that would likely damage its allure for international tourists.
Before this event, Australia's Great Barrier Reef suffered mass coral bleaching in 1998, 2002, 2016, 2017, 2020 and 2022.
Source: AFP and other news agencies

Comment by Dr. Krishna Kumari Challa on March 9, 2024 at 10:46am

For the study, the 5-carbon sugar deoxyribose, which forms the backbone of DNA, was replaced by a 4-carbon sugar. In addition, the number of nucleobases was increased from four to six. By exchanging the sugar, the TNA is not recognized by the cell's own degradation enzymes. This has been a problem with nucleic acid-based therapeutics, as synthetically produced RNA that is introduced into a cell is rapidly degraded and loses its effect.

The introduction of TNAs into cells that remain undetected could now maintain the effect for longer. "In addition, the built-in unnatural base pair enables alternative binding options to target molecules in the cell.

TNAs could also be used for the targeted transport of drugs to specific organs in the body (targeted drug delivery) as well as in diagnostics; they could also be useful for the recognition of viral proteins or biomarkers.

Hannah Depmeier et al, Expanding the Horizon of the Xeno Nucleic Acid Space: Threose Nucleic Acids with Increased Information Storage, Journal of the American Chemical Society (2024). DOI: 10.1021/jacs.3c14626

part2

Comment by Dr. Krishna Kumari Challa on March 9, 2024 at 10:45am

Researchers develop artificial building blocks of life

For the first time, scientists  have developed artificial nucleotides, the building blocks of DNA, with several additional properties in the laboratory, which could be used as artificial nucleic acids for therapeutic applications.

DNA carries the genetic information of all living organisms and consists of only four different building blocks, the nucleotides. Nucleotides are composed of three distinctive parts: a sugar molecule, a phosphate group, and one of the four nucleobases adenine, thymine, guanine, and cytosine.

The nucleotides are lined up millions of times and form the DNA double helix, similar to a spiral staircase. Scientists have now shown that the structure of  nucleotides can be modified to a great extent in the laboratory. The researchers developed so-called threofuranosyl nucleic acid (TNA) with a new, additional base pair.

But artificial nucleic acids differ in structure from their originals. These changes affect their stability and function.  However,  threofuranosyl nucleic acid is more stable than the naturally occurring nucleic acids DNA and RNA, which brings many advantages for future therapeutic use.

These are the first steps on the way to fully artificial nucleic acids with enhanced chemical functionalities. The study "Expanding the Horizon of the Xeno Nucleic Acid Space: Threose Nucleic Acids with Increased Information Storage' was published in the Journal of the American Chemical Society.

part1

Comment by Dr. Krishna Kumari Challa on March 9, 2024 at 10:40am

Ebola-fighting potential of engineered bacteria

The  Ebola virus has proven an especially lethal contagion, killing roughly 50% of the people who contract it. The 2019 FDA approval of a vaccine, combined with the subsequent development of two antibody-based drugs, marked unprecedented progress against one species of the virus. Yet the continuing threat posed by several other types of Ebola has left researchers in pursuit of additional treatments—particularly in developing regions of Africa, where limited infrastructure can impede the storage and deployment of vaccines.

One approach to combating viral threats has come in the form of a microbial counterpart: bacteria. In researching inhibitors of HIV, for instance, some researchers identified the promise of lectins, or bacteria-generated proteins that can selectively bind to the surfaces of viral particles, thereby neutralizing them.

Scientists took a special interest in scytovirin, a type of lectin produced by cyanobacteria, likely the Earth's first oxygen-producing organisms. Because scytovirin had shown some early success in inhibiting Ebola, they went about engineering two strains of lactic acid bacteria, which can safely colonize the human body, to display scytovirin on their own surfaces. The study is published in the journal Frontiers in Microbiology.

After constructing research-safe shells of Ebola particles, the virologists introduced them to the two bacterial strains. Their experiments revealed that one of the engineered strains, Lactococcus lactis, could neutralize roughly 54% of the Ebola particles—more than twice the rate of scytovirin-free L. lactis.

The research team  is now testing the bacteria-delivered antiviral in mice, where the virologists are determining whether the engineered L. lactis can neutralize Ebola the way it did in cell cultures. Passing that test could eventually lead to human trials.

If it does continue to perform, L. lactis—which is already used to make cheese and buttermilk—could become a relatively simple, inexpensive, long-term way to protect vulnerable populations against the devastating virus, the team said.

Joshua Wiggins et al, Lactic acid bacterial surface display of scytovirin inhibitors for anti-ebolavirus infection, Frontiers in Microbiology (2023). DOI: 10.3389/fmicb.2023.1269869

Comment by Dr. Krishna Kumari Challa on March 9, 2024 at 10:26am

Egg-laying caecilian amphibians produce milk for their young, find scientists

Parental care for offspring occurs in many animals and is an essential part of the reproduction, propagation and development of an organism. An international research team has revealed for the first time how egg-laying female caecilian amphibians successfully raise their offspring in the nest.

Caecilian amphibians are one of the least known vertebrate groups. The researchers were able to observe that the females of egg-laying amphibians, such as the species Siphonops annulatus, provide their young a similarly high-fat milk in the nest as, for example, egg-laying mammals. This discovery demonstrates the complexity of the evolution of reproductive strategies in vertebrates and expands our knowledge of brood care and communication in amphibians.

The research is published in the journal Science.

In most vertebrates, the yolk is usually the only form of nutrition females provide to the growing embryo. The research team observed that the young of the Brazilian caecilian Siphonops annulatus consumed milk for over two months, which appears to be secreted in response to tactile and acoustic stimulation from the mother's cloaca. The milk consists mainly of fats and carbohydrates and is produced in the glands of the female's oviduct.

Scientists have now discovered a vertebrate system in amphibians that has developed similarly comprehensive brood care mechanisms as known for mammals. This includes the production of fat-rich mother's milk and the release of milk to the young in the nest, known as lactation. This tells us a lot about the evolution and reproductive strategies of this still little-known vertebrate order.

Caecilian amphibians are legless, snake-like amphibians that are widespread in the tropical regions of the world. All caecilian amphibians provide brood care. The female of the Brazilian amphibian Siphonops annulatus lays eggs and raises its hatchlings in the nest with fat-rich "milk" as well as its skin. Parental brood care is therefore similar to that of egg-laying mammals such as echidnas and platypuses.

Pedro L. Mailho-Fontana et al, Milk provisioning in oviparous caecilian amphibians, Science (2024). DOI: 10.1126/science.adi5379

Comment by Dr. Krishna Kumari Challa on March 9, 2024 at 10:21am

Scientists use the term horizontal gene transfer to describe how living organisms can transfer genetic material between different individuals, including those of other species. In this way, bacteria exchange extensive genetic information, often in the form of plasmids, in order to quickly adapt to changing environmental conditions or to adapt to the host. The rapid evolution of various pathogens is based on such mechanisms, among other things.

In fungi and many other so-called eukaryotic organisms, however, horizontal gene transfer in the form of entire chromosomes is very rare.

The analysis of the genetic information of the fungal strains shows that M. robertsii independently transferred a single chromosome a total of five times during the co-infection experiments, but no other genetic information from one strain to another via horizontal transfer.

Further analyses also indicated that the same chromosome can also be found in the distantly related, also insect-damaging fungus species Metarhizium guizhouense, whose common evolutionary origin with M. robertsii dates back around 15 million years.

The chromosome in M. guizhouense is significantly less altered than would be assumed for the long period of separate evolution of the two fungal species. The chromosome therefore also appears to have been passed on naturally between these different fungal species—and probably horizontally.

The experiments showed that, under certain conditions, the fungus that had received the accessory chromosome had competitive advantages over fungi of the same strain that had not received the chromosome and were able to prevail against them.

The transfer of the chromosome may therefore have advantages for the fungus, the functional basis of which is still unclear. However, one plausible possibility is the transfer of certain genes that produce chitin-cleaving enzymes and can thus improve the ability to infect the insects.

Michael Habig et al, Frequent horizontal chromosome transfer between asexual fungal insect pathogens, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2316284121

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