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Comment by Dr. Krishna Kumari Challa on August 22, 2023 at 9:54am

Bilinguals may have a memory advantage

In any communication, we generate myriad predictions regarding what we are about to hear. To begin with—when we only have one or two letters to go on—the pool of potential candidate words is massive. The more letters we guess correctly, the more the pool of candidate words narrows down, until our brain clicks and we find the right word.

In natural communication, we rarely wait to hear the entire word before we begin to plan what to say back. As soon as we hear the first sounds of a word, our brain uses this information, and together with other clues—such as frequency, context and experience—fills in the blanks, cutting down from a vast list of potential candidate words to predict the target word. But what if you are a bilingual with languages that have similar sounding words? Well, then, the list of candidate words is much larger. This may sound negative—making it more difficult to predict words. But a new study, published in Science Advances, has revealed that this may actually give bilinguals an advantage when it comes to memory.

The languages of a bilingual are interconnected. The same neural apparatus that processes our first language also processes our second language. So it is easy to see why, upon hearing the first sounds of a word, potential candidate words are activated, not only from one language, but from the other one as well.

For instance, upon hearing the sounds "k" and "l", a Spanish-English bilingual will automatically activate both the words "clock" and "clavo" (nail in Spanish). This means the bilingual has a tougher cutting down job to do in order to settle on the correct word, simply because there is more to cut down to get to the target. It is not surprising then that bilinguals usually take more time to retrieve or recognize words in psychological and linguistic experiments.

The findings showed that recognition memory for objects with many competitors (such as beaker, beetle, speaker) was enhanced relative to items with low competitors (such as carriage) in both monolinguals and bilinguals. In addition, bilinguals showed the effect for cross-language competitors as well (for example clock, clavo)—giving an overall memory advantage.

Interestingly, second language proficiency played a crucial role. The memory advantage was most profound in bilinguals with high second language proficiency than in bilinguals with low second language proficiency and monolinguals. Clearly, to play bilingual hangman efficiently, you need to develop high proficiency in the second language, so that its words become competitors alongside those of the first language.

Part 1

Comment by Dr. Krishna Kumari Challa on August 22, 2023 at 9:44am

The projective measurement approach to quantum tomography can be thought of as looking at the shadows of a high-dimensional object projected on different walls from independent directions. All a researcher can see is the shadows, and from them, they can infer the shape (state) of the full object. For instance, in CT scan (computed tomography scan), the information of a 3D object can thus be reconstructed from a set of 2D images.

In classical optics, however, there is another way to reconstruct a 3D object. This is called digital holography, and is based on recording a single image, called interferogram, obtained by interfering the light scattered by the object with a reference light.

Researchers now  extended this concept to the case of two photons.

Reconstructing a biphoton state requires superimposing it with a presumably well-known quantum state, and then analyzing the spatial distribution of the positions where two photons arrive simultaneously. Imaging the simultaneous arrival of two photons is known as a coincidence image. These photons may come from the reference source or the unknown source. Quantum mechanics states that the source of the photons cannot be identified. This results in an interference pattern that can be used to reconstruct the unknown wave function. This experiment was made possible by an advanced camera that records events with nanosecond resolution on each pixel.

This method is exponentially faster than previous techniques, requiring only minutes or seconds instead of days. Importantly, the detection time is not influenced by the system's complexity—a solution to the long-standing scalability challenge in projective tomography.

The impact of this research goes beyond just the academic community. It has the potential to accelerate quantum technology advancements, such as improving quantum state characterization, quantum communication, and developing new quantum imaging techniques.

Danilo Zia et al, Interferometric imaging of amplitude and phase of spatial biphoton states, Nature Photonics (2023). DOI: 10.1038/s41566-023-01272-3

Part 2

Comment by Dr. Krishna Kumari Challa on August 22, 2023 at 9:41am

 Quantum entanglement of photons captured in real-time

Researchers  recently demonstrated a novel technique that allows the visualization of the wave function of two entangled photons, the elementary particles that constitute light, in real-time.

Using the analogy of a pair of shoes, the concept of entanglement can be likened to selecting a shoe at random. The moment you identify one shoe, the nature of the other (whether it is the left or right shoe) is instantly discerned, regardless of its location in the universe. However, the intriguing factor is the inherent uncertainty associated with the identification process until the exact moment of observation.

The wave function, a central tenet in quantum mechanics, provides a comprehensive understanding of a particle's quantum state.  For instance, in the shoe example, the "wave function" of the shoe could carry information such as left or right, the size, the color, and so on.

More precisely, the wave function enables quantum scientists to predict the probable outcomes of various measurements on a quantum entity, e.g. position, velocity, etc.

This predictive capability is invaluable, especially in the rapidly progressing field of quantum technology, where knowing a quantum state which is generated or input in a quantum computer will allow to test the computer itself. Moreover, quantum states used in quantum computing are extremely complex, involving many entities that may exhibit strong non-local correlations (entanglement).

Knowing the wave function of such a quantum system is a challenging task—this is also known as quantum state tomography or quantum tomography in short. With the standard approaches (based on the so-called projective operations), a full tomography requires large number of measurements that rapidly increases with the system's complexity (dimensionality).

Previous experiments conducted with this approach by the research group showed that characterizing or measuring the high-dimensional quantum state of two entangled photons can take hours or even days. Moreover, the result's quality is highly sensitive to noise and depends on the complexity of the experimental setup.

Part 1

Comment by Dr. Krishna Kumari Challa on August 21, 2023 at 12:58pm

India Is About to Attempt Its First Ever Moon Landing Can anybody else ever feel the same way Neil Armstrong felt when he first stepped on the moon? Or how Watson, Rosalind Franklin and Crick felt when they first discovered the double helix of DNA? Their experiences are mind blowing and no amount of money can buy you that thrill. Can anybody feel the same way scientists feel when they discover/invent something for the first time and report it to the world? NO. Nothing in this world compares to it. Experience at least some of it when the Indian Space Research Organisation (ISRO) mission Chandrayaan-3 will deploy its lander and rover to the surface of the Moon on 23rd Aug. Chandrayaan-3, is all set to make a soft and successful landing on the south polar region of the Moon around 6.04pm today, August 23. In case of 'unfavourable conditions' the landing may be postponed to August 27. But that is not on the cards right now. Viewers can watch the live landing on the ISRO website, its YouTube channel, Facebook, and public broadcaster DD National TV starting at 5:27 PM (IST) on August 23 (today). Every success by a space agency means more free-to-use data for both the scientific community and the public. Come join us on this epic journey.

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Gravitational Waves: Ripples In Space-Time

Comment by Dr. Krishna Kumari Challa on August 21, 2023 at 12:11pm

This tightens competition among the creatures living there, the researchers explain, making rivalry a big factor in determining the pools' biodiversity. With so few other niches to fall back on, any species that can't compete will struggle to survive.

Most animals serve as hosts or carriers for parasites of some kind, and water fleas are no exception. It's rare to find a species with nearly total parasite resistance, yet the study did include one Daphnia species with an almost supernatural ability to withstand parasites.

"In the population of water fleas in Israel, we found one species called Daphnia similis, whose nickname in the laboratory is 'Super Daphnia' due to its almost complete resistance to parasites.
Nevertheless, this 'Super Daphnia' does not become the dominant Daphnia species in ponds.
The most common species is actually Daphnia magna, which is highly vulnerable to a wide variety of parasites."

To figure out why, the researchers simulated an ecosystem in the lab, placing the two Daphnia species together in habitats either with or without parasites.

In a habitat free of parasites, not only did the parasite-sensitive D. magna outcompete its parasite-resistant relative, the study found, but it was the only Daphnia left standing.
Things played out differently in habitats with parasites, however, where D. magna proved less dominant and Super Daphnia managed to establish a population and coexist with D. magna – thanks to a little help from parasites.

"The results of these experiments emphasize the important role of parasites in shaping biodiversity, as the parasites can mediate competition between Daphnia species.
Although Super Daphnia excels at resisting parasites, its overall competitive ability still doesn't match that of D. magna and without parasites it "would probably become extinct when it shares the same habitat."
This work shows that coexistence of these two Daphnia species is only possible through the mediation of a parasite..
By learning details like this about the ecological sway of parasites, the researchers say, we may gain new insights to help us fend off invasive species or better protect endangered wildlife.

https://www.frontiersin.org/articles/10.3389/fmicb.2023.1135252/full

Part 3

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Comment by Dr. Krishna Kumari Challa on August 21, 2023 at 12:08pm

In a new study, researchers focused on how parasites influence populations of tiny crustaceans commonly called "water fleas," from the genus Daphnia.
Daphnia grow up to 5 millimeters long, inhabiting various freshwater habitats where they feed on single-celled algae, bacteria, and protists. In turn, they serve as a food source for other larger aquatic species, like fish, tadpoles, and insects.

Using two Daphnia species with differing levels of parasite resistance, the researchers tested how the presence of parasites affected an ecological phenomenon known as the competitive exclusion principle, or Gause's law, among the water fleas.

Biodiversity is a key feature of healthy ecosystems, Orlansky and Ben-Ami note, and related species can share space if their relationships with predators and natural resources are different enough.

According to Gause's law, however, two species with identical niches in the same habitat can't coexist indefinitely at constant levels. If they're too similar, even a small advantage can help one species dominate, leaving others to eventually die out or seek a different niche.
The Daphnia species in this study are adapted to small rock pools – relatively enclosed habitats where many aquatic lifeforms can't migrate or come and go on their own.
Part 2

Comment by Dr. Krishna Kumari Challa on August 21, 2023 at 12:06pm

Parasites Are Actually Vital For Some Species' Survival, Study Shows

Parasites are understandably unpopular. Some cause horrible illnesses in their hosts, and even the less dangerous ones are often creepy or gross.

While they can be monsters, parasites aren't all bad. Many organisms benefit from species that survive by sucking the very life from others. Even their hosts might get a kickback or two.
Now a new study suggests some species can only survive in certain habitats if parasites are there, too.

Parasites come in many shapes and sizes, from viruses and amoebae to plants like mistletoe and animals like nematodes or mosquitoes. They all use a host for resources, which they typically harm but don't kill. As the late entomologist E.O. Wilson put it, parasites are "predators that eat prey in units of less than one."

Similar to the way predators can help regulate their overall ecosystem, parasites often provide overlooked ecological services that are only obvious in their absence.
the horrors of individual parasitic infections belie the surprising value these creatures offer for their broader community.

"Parasites and pathogens are an integral part of any ecosystem. Despite their bad reputation, parasites play a key role in shaping population dynamics, community structure, and biodiversity, thanks to their influence on the balance between the species in that ecosystem
Part 1

Comment by Dr. Krishna Kumari Challa on August 20, 2023 at 12:50pm

Why Does It Take a While For a Tan to Show Up? Scientists Have Finally Worked It Out

Your skin's response to Sun exposure may seem delayed, but there's a good reason for it, scientists have found.

Through experiments on both human and mouse skin, researchers  have discovered that the development of a tan only occurs after the skin has taken care of emergency DNA repair.

We have two mechanisms designed to protect the skin from exposure to dangerous UV radiation. 

The first mechanism repairs the DNA in the skin cells damaged by the radiation, while the second mechanism involves increased production of melanin, which darkens the skin in order to protect it from future exposure to radiation.

The delay in tanning is a result of resource prioritization. Basically, all of the cell's resources mobilize to repair radiation damage as quickly as possible. It's only once that task is complete that the cell can allocate resources to the production of melanin.

To test this hypothesis, the researchers first exposed human skin, obtained from consenting surgery patients and cultured in petri dishes, to UVB radiation. This was so that they could study the activity in the cell in response to radiation damage. They confirmed that a protein kinase called ATM, activated by DNA damage and critical to cell repair, springs into action shortly after exposure to UVB radiation. That's interesting, but the team needed more information. So, the follow-up step was to trigger the activation of ATM in the absence of UVB exposure and observe the results. This phase of the experiment was conducted on mouse models, and more human skin samples in petri dishes. In both mouse and human skin, a tan developed after an interval, even in the absence of harmful radiation. A close inspection of the cellular processes involved showed that the activation of ATM blocks the activation of the MITF protein responsible for increasing melanin production, so that DNA repair can take precedence.

The genetic information must be protected from mutations, so this repair mechanism takes precedence inside the cell during exposure to ultraviolet radiation from the sun.

The team suspects that DNA repair may even harness some of the components of the pigmentation mechanism in order to maximize the chances of cell survival, and minimize the chances of mutation. The discovery, the team says, could be used to help study, understand, prevent, and treat the effects of skin radiation damage.

https://www.sciencedirect.com/science/article/abs/pii/S0022202X2302...

Comment by Dr. Krishna Kumari Challa on August 20, 2023 at 12:30pm

Scientists find way to wipe a cell's memory to better reprogram it as a stem cell

In a study published in Nature,  scientists have resolved a long-standing problem in regenerative medicine. They developed a new method to reprogram human cells to better mimic embryonic stem cells, with significant implications for biomedical and therapeutic uses.

In a revolutionary advance in the mid-2000s, it was discovered that the non-reproductive adult cells of the body, called somatic cells, could be artificially reprogrammed into a state that resembles embryonic stem (ES) cells which have the capacity to then generate any cell of the body.

The ability to artificially reprogram human somatic cells, such as skin cells, into these so-called induced pluripotent stem (iPS) cells provided a way to make an essentially unlimited supply of ES-like cells, with widespread applications in disease modeling, drug screening and cell-based therapies.

However, a persistent problem with the conventional reprograming process is that iPS cells can retain an epigenetic memory of their original somatic state, as well as other epigenetic abnormalities. This can create functional differences between the iPS cells and the ES cells they're supposed to imitate, and specialized cells subsequently derived from them, which limits their use.

Researchers have now developed a new method, called transient-naïve-treatment (TNT) reprogramming, that mimics the reset of a cell's epigenome that happens in very early embryonic development. This significantly reduces the differences between iPS cells and ES cells and maximizes the effectiveness of how human iPS cells can be applied. 

By studying how the somatic cell epigenome changed throughout the reprogramming process, they pinpointed when epigenetic aberrations emerged, and introduced a new epigenome reset step to avoid them and erase the memory.

TNT reprogramming will establish a new benchmark for cell therapies and biomedical research, and substantially advance their progress.

https://www.nature.com/articles/s41586-023-06424-7?utm_medium=affil...

Comment by Dr. Krishna Kumari Challa on August 20, 2023 at 12:24pm

Using magnetic rust nanoparticles to clean water

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