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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...

Comment by Dr. Krishna Kumari Challa on November 23, 2023 at 8:39am

How to keep polio from coming back

Poliovirus is close to being eliminated: it could be gone within three years. But eradication is not extinction. The next challenge will be keeping it at bay. In rare cases, the oral poliovirus vaccine can itself seed a polio outbreak. But withdrawing that vaccine will leave people unprotected. The inactivated poliovirus vaccine doesn’t have the same flaw, but it doesn’t block transmission, so a broad vaccination programme would have to continue. And we will have to be sure that polio can never escape from a research institute or vaccine-manufacturing facility. Finally, a very tiny — but unknown — number of people have immune-deficiency disorders that mean they can carry and spread polio without knowing it, for years.

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Study uncovers no compelling evidence that air purifiers prevent re...

The COVID pandemic led to many calls for improved indoor air quality with claims that doing so would reduce the risk of the virus spreading. However, the real-world evidence to support these claims has been lacking, and studies undertaken during the pandemic have not yet been reported.

Comment by Dr. Krishna Kumari Challa on November 23, 2023 at 8:34am

Wi-Fi for nerve signals
Researchers have charted a long-distance ‘wireless’ nerve network in Caenorhabditis elegans worms for the first time. The nervous system can be thought of as a web of neurons that pass on messages through direct links, called synapses. But neurons can also communicate over longer distances by releasing molecules called neuropeptides, which are intercepted by other neurons some distance away. Incorporating both ‘wired’ synaptic connections and wireless signalling better predicts how signals travel in the worm than does a model using synaptic connections alone.

https://www.nature.com/articles/d41586-023-03619-w?utm_source=Live+...

Randi, F., Sharma, A. K., Dvali, S. & Leifer, A. M. Nature 623, 406–414 (2023).

Ripoll-Sánchez, L. et al. Neuron 111, 3570–3589 (2023).

Wang, H. et al. Science 382, eabq8173 (2023).

Comment by Dr. Krishna Kumari Challa on November 23, 2023 at 8:26am

Researchers pinpoint brain area where people who are blind recognize faces identified by sound

Using a specialized device that translates images into sound, neuroscientists  showed that people who are blind recognized basic faces using the part of the brain known as the fusiform face area, a region that is crucial for the processing of faces in sighted people.

It's been known for some time that people who are blind can compensate for their loss of vision, to a certain extent, by using their other senses.

This study tested the extent to which this plasticity, or compensation, between seeing and hearing exists by encoding basic visual patterns into auditory patterns with the aid of a technical device researchers refer to as a sensory substitution device. With the use of functional magnetic resonance imaging (fMRI), they can determine where in the brain this compensatory plasticity is taking place.

Face perception in humans and nonhuman primates is accomplished by a patchwork of specialized cortical regions. How these regions develop has remained controversial. Due to their importance for social behavior, many researchers think that the neural mechanisms for face recognition are innate in primates or depend on early visual experience with faces.

The new results  from people who are blind imply that fusiform face area development does not depend on experience with actual visual faces but on exposure to the geometry of facial configurations, which can be conveyed by other sensory modalities.

Josef Rauschecker et al, Sound-encoded faces activate the left fusiform face area in the early blind, PLoS ONE (2023). journals.plos.org/plosone/arti … journal.pone.0286512

Comment by Dr. Krishna Kumari Challa on November 23, 2023 at 8:16am

Careful histological and morphological observations revealed that the stolon formation starts with the maturation of gonads in the posterior end. Then forms a head in the anterior part of the developing stolon. Sense organs such as eyes and antennae, and swimming bristles form soon after. Before the stolon detaches, it develops nerves and a 'brain' to sense and behave independently.

To understand the development of stolon's head, researchers investigated the developmental gene expression patterns of the sexually maturing worms. A well-known group of head formation genes are known to define the head region of various animals. They found that these genes are expressed more in the head region of the stolon. Typically, the head formation genes are not expressed as much in the middle of the body. But during gonad development in syllids, head formation genes are highly expressed in the middle of the posterior end of the original body.

This shows how normal developmental processes are modified to fit the life history of animals with unique reproductive styles.

Morphological, Histological and Gene-Expression Analyses on Stolonization in the Japanese Green Syllid, Megasyllis nipponica (Annelida, Syllidae), Scientific Reports (2023). DOI: 10.1038/s41598-023-46358-8

Part 2

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