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Comment by Dr. Krishna Kumari Challa on November 27, 2023 at 1:05pm

The bilingual brain may be better at ignoring irrelevant information

People who speak two languages may be better at shifting their attention from one thing to another compared to those who speak one, according to a study published this month in the journal Bilingualism: Language and Cognition.

The study examined differences between bilingual and monolingual individuals when it comes to attentional control and ignoring information that isn't important at the time. 

Our results showed that bilinguals seem to be more efficient at ignoring information that's irrelevant, rather than suppressing—or inhibiting information. One explanation for this is that bilinguals are constantly switching between two languages and need to shift their attention away from the language not in use.

For example, if an English- and Spanish-speaking person is having a conversation in Spanish, both languages are active, but English is put on hold but always ready to be deployed as needed. Numerous studies have examined the distinctions between the two groups in broad cognitive mechanisms, which are mental processes that our brains use, like memory, attention, problem-solving, and decision-making.

The effects of speaking two languages on a person's cognitive control is often debated. Some of the literature says these differences aren't so pronounced, but that could be because of the tasks linguists use to research differences between bilinguals and monolinguals.

Now what about people who can speak several languages?

Grace deMeurisse et al, Bilingual attentional control: Evidence from the Partial Repetition Cost paradigm, Bilingualism: Language and Cognition (2023). DOI: 10.1017/S1366728923000731

Comment by Dr. Krishna Kumari Challa on November 26, 2023 at 12:21pm

Scientists finally work out what causes itching

Comment by Dr. Krishna Kumari Challa on November 26, 2023 at 11:59am

Scientists Find 'Kill Switch' That Activates Cancer Cell Death in The Lab

Scientists have figured out a way to detonate the 'doors' that lead to the heart of cancerous tumors, blowing them wide open for drug treatments.

The strategy works by triggering a 'timer bomb' on the cells that line a tumor's associated blood vessels.

These vessels control access to the tumor tissue, and until they are opened, engineered immune cells can't easily gain entry to the cancer to fight it off. The timer bomb on these cells is actually a 'death' receptor, called Fas (or CD95). When activated by the right antibody, it triggers the programmed death of that cell.

In recent experiments using mouse models and human cell lines, scientists have at last identified specific antibodies that, when attached to Fas receptors, effectively trigger self-implosion. now that we've identified this epitope, there could be a therapeutic path forward to target Fas in tumors. The antibody that binds to this epitope (a specific part of the death receptor), essentially represents the kill switch for the cell. Once this immune checkpoint is blown open, other cancer therapies, like CAR-T therapy, can gain access to more of their targets, which are often clumped together and hidden within the tumor. CAR-T therapy works by programming a person's own white blood cells, called T-cells, to bind to and attack specific types of cancerous cells. These tailored immune cells, however, cannot usually get past the 'bystander' cells that lack the recognisable antigens usually used to target tumor cells. As a result, CAR-T therapy has only been approved to treat blood cancers or leukemia. It fails to provide consistent success against solid tumors till now. In recent experiments , scientists developed two engineered antibodies that were "supremely effective" at attaching to Fas receptors and causing bystander cells to self-implode. This was true in ovarian cancer models and many other tumor cell lines tested in the lab. The Fas ligand developed by researchers was able to engage two critical parts of the Fas receptor, which researchers say should be investigated further. These parts hold potential as future drug targets.

https://www.nature.com/articles/s41418-023-01229-7

Comment by Dr. Krishna Kumari Challa on November 26, 2023 at 11:52am

Death by Stem Cell: Developing New Cancer Therapies

Engineering stem cells to deliver cancer therapeutics directly to tumors, thereby increasing their efficacy.

While chemotherapy, surgery, and radiation therapy are traditional cancer treatments that can be applied individually or in combination, a patient’s response to these approaches depends on cancer type, location, heterogeneity, and drug resistance.2 Consequently, researchers need to develop novel therapies and delivery methods.

Some researchers are developing cancer therapeutics that use stem cells as delivery vectors to treat primary and metastatic brain and lung cancers. In a recently published Science Translational Medicine paper, some of them  showed an allogeneic twin stem cell system carrying oncolytic viral particles and immunomodulators to treat brain metastases.  A few weeks later, they also published a Stem Cells Translational Medicine paper, where they engineered mesenchymal stem cells to secrete a bi-functional molecule targeting two receptors in lung tumors, leading to cancer cell death.

1. Siegel RL, et al. Cancer statistics, 2023. CA Cancer J Clin. 2023;73(1):17-48.
2.  Debela DT, et al. New approaches and procedures for cancer treatment: Current perspec.... SAGE Open Med. 2021;9.
3.  Kanaya N, et al. Gene-edited and -engineered stem cell platform drives immunotherapy.... Sci Transl   Med. 2023;15(698):eade8732.
4.  Moleirinho S, et al. Fate and efficacy of engineered allogeneic stem cells targeting cel.... Stem Cells Transl Med. 2023;12(7):444-458.

Comment by Dr. Krishna Kumari Challa on November 26, 2023 at 11:22am

Plastic waste in the water might be stopping, or interrupting, some shrimp-like creatures from reproducing
In a unique study, published in the journal Environmental Pollution,the ability of "shrimp-like" creatures to reproduce successfully was found to be compromised by chemicals found in everyday plastics.

Research showed that little critters, known as marine amphipod Echinogammarus marinus, changed their mating behavior when exposed to toxic plastic additives.

Until now, most research into plastic pollution has focused on visual plastics; what can get trapped in plastics and the dangers of ingesting large particles. Scientists now have taken a different approach and investigated the chemicals that are used as ingredients in plastics.
This unsuccessful mating behavior has serious repercussions, not only for the species being tested but potentially for the population as a whole. These animals form pairs to reproduce. Once they were exposed to a chemical, they would break apart from their mate and take much longer—in some cases days—to re-pair, and sometimes not at all.
These creatures make up a substantial amount of the diet of fish and birds. If they are compromised it will have an effect on the whole food chain.
There are more than 350,000 chemicals in use around the world in everyday products. Ten thousand of these are used to enhance plastics. Chemicals can be used to make plastics more flexible, add color, give sun protection or make plastic flameproof. About one-third of these chemicals are known to be toxic to human's immune, nervous or reproductive systems.
Although the animals we tested were exposed to much higher concentrations than you would normally find in the environment, the results indicate these chemicals can affect sperm count.

Bidemi Green-Ojo et al, Evaluation of precopulatory pairing behaviour and male fertility in a marine amphipod exposed to plastic additives, Environmental Pollution (2023). DOI: 10.1016/j.envpol.2023.122946

Comment by Dr. Krishna Kumari Challa on November 25, 2023 at 11:07am

Reactivating silenced fetal hemoglobin genes could counter sickle cell–related diseases

Researchers from multiple institutions  have found a way to use gene editing to reactivate dormant fetal oxygen-transporting proteins in adult blood cells to potentially reverse a wide range of blood disorders.

In a paper, "Base editing of the HBG promoter induces potent fetal hemoglobin expression with no detectable off-target mutations in human HSCs," published in Cell Stem Cell, the team compares gene editing techniques while formulating a method that could have important clinical applications.

Fetal gamma (γ) globin is normally replaced by adult (β) hemoglobin during development. In an odd quirk of evolution, only humans and a few types of monkeys are known to switch from γ to β gene expression. The genes producing the fetal hemoglobin become silenced and dormant after the genetic switch by repressors such as BCL11A and ZBTB7A, whose binding motifs have been identified as targets for reactivation. β-hemoglobinopathies, including β-thalassemia and sickle cell disease, result from mutations in the HBB gene, leading to impaired β-globin production and resulting in anemia, impaired oxygen delivery to tissues and possible multi-organ tissue damage. The researchers experimentally discovered that reactivating γ-globin expression could be developed into a universal therapeutic strategy for these conditions.

Wenyan Han et al, Base editing of the HBG promoter induces potent fetal hemoglobin expression with no detectable off-target mutations in human HSCs, Cell Stem Cell (2023). DOI: 10.1016/j.stem.2023.10.007

Comment by Dr. Krishna Kumari Challa on November 25, 2023 at 9:49am

Biohybrid microrobots could remove micro- and nano-plastics from aquatic environments

Micro and nano plastics are harmful tiny particles derived from the disintegration of plastic waste released into the water. These particles have been found to disrupt aquatic ecosystems, for instance, delaying the growth of organisms, reducing their food intake, and damaging fish habitats.

Devising effective technologies to effectively remove these tiny particles is of utmost importance, as it could help to protect endangered species and their natural environments. These technologies should be carefully designed to prevent further pollution and destruction; thus, they should be based on environmentally friendly materials.

Researchers recently developed biohybrid microrobots that could remove micro- and nano-plastics from polluted water without causing further pollution. These robots, presented in a paper published in Advanced Functional Materials, integrate biological materials, specifically algae, with environmentally friendly materials that respond to external magnetic fields. 

The new robots they created, dubbed magnetic algae robots (MARs), consist of a combination of algae and environmentally friendly magnetic nanoparticles.

These robots operate under the influence of an external magnetic field, enabling precise control over their movement. The negative surface charge of MARs is attributed to the presence of -COOH groups on the surface of algae cells. In contrast, the selected micro/nano plastics carry a positive surface charge. This positive-negative interaction facilitates electrostatic attraction, thereby promoting the targeted capture and removal of micro/nano plastics by the MARs.

The unique composition of the robots created by the researchers makes them both non-polluting and responsive to externally applied magnetic fields. This could allow them to sustainably retrieve nano- and micro-sized plastic particles from aquatic environments.

 Xia Peng et al, Biohybrid Magnetically Driven Microrobots for Sustainable Removal of Micro/Nanoplastics from the Aquatic Environment, Advanced Functional Materials (2023). DOI: 10.1002/adfm.202307477

Comment by Dr. Krishna Kumari Challa on November 24, 2023 at 12:44pm

It all started with the observation of a mutant of the model species Arabidopsis thaliana, the thale cress, whose stem was surprisingly transparent.

 These plants failed to respond to light correctly. The  biologists in the group then decided to call on the skills of their  colleagues in other fields in order to further compare the specific optical properties of the mutant versus wild-type samples.

They found that the natural milky appearance of the stems of young wild plants was in fact due to the presence of air in intercellular channels precisely located in various tissues. In the mutant specimens, the air is replaced by an aqueous liquid, giving them a translucent appearance.

But what purpose do such air-filled channels serve? They enable the photosensitive stem to establish a light gradient that can be "read" by the plant. The plant can then determine the origin of the light source. This phenomenon is due to the different optical properties of air and water, which make up the majority of living tissue.

More specifically, air and water have different refractive indices. This leads to light scattering as it passes through the seedling.

Thanks to their research, the scientists have revealed a novel mechanism that enables living organisms to perceive where the light is coming from, enabling them to position their organs such as leaves in a way that optimizes light capture for photosynthesis. The study also provided a better understanding of the formation of air-filled intercellular channels, which have a range of functions in plants, in addition to the formation of light gradients.

Ganesh M. Nawkar et al, Air channels create a directional light signal to regulate hypocotyl phototropism, Science (2023). DOI: 10.1126/science.adh9384. www.science.org/doi/10.1126/science.adh9384

Part 2

Comment by Dr. Krishna Kumari Challa on November 24, 2023 at 12:40pm

Study shows plants use air channels to create a directional light signal and regulate phototropism

Plants have no visual organs, so how do they know where light comes from? In an original study combining expertise in biology and engineering, scientists  uncovered that a light-sensitive plant tissue uses the optical properties of the interface between air and water to generate a light gradient that is "visible" to the plant. These results have been published in the journal Science.

The majority of living organisms (micro-organisms, plants and animals) have the ability to determine the origin of a light source, even in the absence of a sight organ comparable to the eye. This information is invaluable for orienting oneself or optimal positioning in the environment.

Perceiving where light is coming from is particularly important for plants, which use this information to position their organs, a phenomenon known as phototropism. This enables them to capture more of the sun's rays, which they then convert into chemical energy through the process of photosynthesis, a vital process that is necessary for the production of nearly all of the food we eat.

Although the photoreceptor that initiates phototropism has long been known, the optical properties of photosensitive plant tissue have until now remained a mystery. A multidisciplinary study uncovered a surprising tissue feature allowing plants to detect directional light cues.

Part 1

Comment by Dr. Krishna Kumari Challa on November 23, 2023 at 10:37am

Space Communication: beaming messages via laser

Beaming messages via laser across a distance of almost 16 million kilometers or 10 million miles is no longer fiction.

That's about 40 times farther than the Moon is from Earth, and it's the first time that optical communications have been sent across such a distance. Traditionally, we use radio waves to talk to distant spacecraft – but higher frequencies of light, such as near infrared, offer an increase in bandwidth and therefore a huge boost in data speed. If we're going to be able to send high-definition video messages to and from Mars without a significant delay, then this is the tech we need. The test is part of NASA's Deep Space Optical Communications (DSOC) experiment, and the successful establishment of the comms link is known as 'first light'.

https://www.jpl.nasa.gov/missions/deep-space-optical-communications...

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