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Comment by Dr. Krishna Kumari Challa on March 17, 2021 at 9:43am

Researchers identify a class of neurons that are most active during non-REM sleep

Typically, pyramidal cells and GABAergic interneurons in the brain are activated simultaneously. A team of neuroscientists at New York University, however, recently identified a unique class of neurons that do not fire at the same time as all principal neurons, cells and interneurons. Interestingly, the team found that these specific neurons are most active during the DOWN state of non-REM (NREM) sleep, when all other neuron types are silent.

 In their study, researchers identified a class of neurons that appear to be most active when all other neurons (i.e., excitatory pyramidal and inhibitory neurons) are silent, in the DOWN state, during NREM stages of sleep. In their follow up experiments, they showed that these neurons are neuroglia-form cells found in the deeper layers of the neocortex, which specifically express genes known as ID2 and Nkx2.1.

When they examined this class of neurons more in depth, they observed that they had an entirely antagonistic relationship with all other known types of neurons in all wakefulness states (i.e., both when mammals are awake and asleep). This suggests that these neurons could have a unique function that sets them apart from all other cells in the brain.

Sleep down state-active ID2/Nkx2.1 interneurons in the neocortex. Nature Neuroscience(2021). DOI: 10.1038/s41593-021-00797-6.

https://medicalxpress.com/news/2021-03-class-neurons-non-rem.html?u...

Comment by Dr. Krishna Kumari Challa on March 17, 2021 at 8:09am

Comment by Dr. Krishna Kumari Challa on March 17, 2021 at 7:24am

https://www.iqair.com/world-most-polluted-cities

India third-most polluted country; Delhi most polluted capital city: Report

India is the third-most polluted country in the world. Delhi is the most polluted capital city in the world. Thirty-seven of the forty most polluted cities in the world are in South Asia.

These are the findings of the 2020 World Air Quality Report released by IQAir.

• A mere 1.6% of the cities in South Asia met the WHO PM2.5 target in 2020.
• Thirty-seven of the forty most polluted cities in the world in 2020 are in South Asia.

• Nearly 13 to 22% of deaths in South Asia are linked to air pollution.
• Air pollution causes a loss of 7.4% of South Asia's GDP.
• India, Pakistan, and Bangladesh generally experience the worst air quality in this region, with 32%, 67%, and 80% of cities averaging a US AQI measurement of “Unhealthy” (> 55.5 μg/m³), respectively.

• India showed an overall improvement in several cities, with 63% reporting direct improvements over 2019 averages. All cities whose pollution levels increased in 2020 still show an overall downward trend from 2018 and earlier.
• South and East Asian countries continue to be the most polluted locations.
• Bangladesh, China, India, and Pakistan share 49 of the 50 of the most polluted cities worldwide.

• Air pollution contributes to nearly 7 million premature deaths annually. A staggering 600,000 of these deaths include children.
• Air pollution is estimated to cost the global economy upwards of $2.9 trillion per year, which is equal to 3.3% of the global GDP.
• The Covid-19-induced lockdown resulted in a temporary reduction in fossil-fuel consumption. This resulted in a significant decrease in air pollution.
• 2020 saw a remarkable 65% of global cities experience air quality improvements from 2019, while 84% of countries saw improvements overall.
• The report was compiled by the world's largest database of ground-based air pollution measurements, aggregating PM2.5 data published in real-time from ground-based sensors throughout 2020.
• The 2020 World Air Quality Report includes data for 106 countries, up from 98 countries in 2019 and 69 countries in 2018.

This report  highlights that urgent action is both possible and necessary to combat air pollution, which remains the world’s greatest environmental health threat.

https://health.economictimes.indiatimes.com/news/industry/india-thi...

Comment by Dr. Krishna Kumari Challa on March 16, 2021 at 12:51pm

Outbreak of Mysterious Paralyzing Condition Squashed by COVID–19 Pandemic

The grim pall of the COVID-19 pandemic ensures that 2020 will go down as an infamous year in the history of human disease.

But this dark chapter held some surprises we can be thankful for, too. In a new study, researchers found that a predicted 2020 outbreak of a mysterious paralyzing illness failed to materialize on schedule – and in a weird way, we actually have the coronavirus to thank for it.

The condition in question is called acute flaccid myelitis (AFM). This polio-like neurological disease mainly affects children, causing muscle weakness and, in some cases, permanent paralysis and even death.

For decades, cases of AFM were very rare, but in recent years, larger outbreaks across the US and elsewhere have occurred, seemingly reoccurring every two years.

A body of previous research has linked AFM to a rare virus called enterovirus D68 (EV-D68), and while it's not yet known how the virus manifests the symptoms of the AFM disease, coinciding outbreaks of the pair have led researchers to think they are almost certainly related.

In the new research, a team led by first author and infectious disease modeler Sang Woo Park from Princeton University tracked patterns of cases of EV-D68 between 2014 and 2019, with the virus staging significant resurgences in even-numbered years – 2014, 2016, and 2018 – which are thought to be attributable to climate-based factors.

The data suggested 2020 was due for another hit.

"We predicted that a major EV-D68 outbreak, and hence an AFM outbreak, would have still been possible in 2020 under normal epidemiological conditions," the researchers explain in their study.

Of course, as the world was at pains to witness, the epidemiological conditions of 2020 were anything but ordinary, and the expected combo hit of EV-D68 and AFM never came.

https://stm.sciencemag.org/content/13/584/eabd2400

https://www.sciencealert.com/outbreak-of-mysterious-paralyzing-cond...

Comment by Dr. Krishna Kumari Challa on March 16, 2021 at 12:47pm

Scientists Reveal How Many Interstellar Objects May Be Visiting Our Solar System

According to a new study led by researchers from the Initiative for Interstellar Studies (i4is), roughly seven ISOs enter our Solar System every year and follow predictable orbits while they are here.

This research could allow us to send a spacecraft to rendezvous with one of these objects in the near future.

https://www.universetoday.com/150478/there-should-be-about-7-inters...

Comment by Dr. Krishna Kumari Challa on March 16, 2021 at 12:24pm

Comment by Dr. Krishna Kumari Challa on March 16, 2021 at 12:19pm

The Mating Dance of a bird

Comment by Dr. Krishna Kumari Challa on March 16, 2021 at 12:02pm

When memory qubits and photons get entangled

Encrypting data in a way that ensures secure communication is an ever-growing challenge because crucial components of today's encryption systems cannot withstand future quantum computers. Researchers around the world are therefore working on technologies for novel encryption methods that are also based on quantum effects. The phenomenon of so-called quantum entanglement plays a particularly important role here. This means that in a quantum network, the stationary qubits of the network are entangled with the communication channel, which usually consists of photons (light particles). For the first time, physicists at the University of Bonn have now been able to demonstrate quantum entanglement between a stationary qubit, i.e. a two-state quantum system, and a photon with direct coupling to an optical fiber. The study has been published in the journal npj Quantum Information.

Pascal Kobel et al. Deterministic spin-photon entanglement from a trapped ion in a fiber Fabry–Perot cavity, npj Quantum Information (2021). DOI: 10.1038/s41534-020-00338-2

Quantum systems originate from the world of particles and smallest structures and may be relevant for future technologies. If different quantum information carriers (quantum nodes) are interconnected by quantum channels, researchers speak of quantum networks. 

https://phys.org/news/2021-03-memory-qubits-photons-entangled.html?...

Comment by Dr. Krishna Kumari Challa on March 16, 2021 at 11:57am

Practical nanozymes discovered to fight antimicrobial resistance

Nanozymes, a group of inorganic catalysis-efficient particles, have been proposed as promising antimicrobials against bacteria. They are efficient in killing bacteria, thanks to their production of reactive oxygen species (ROS).

Despite this advantage, nanozymes are generally toxic to both bacteria and mammalian cells, that is, they are also toxic to our own cells. This is mainly because of the intrinsic inability of ROS to distinguish bacteria from mammalian cells.

In a study published in Nature Communications, the research team proposed a novel method to construct efficient-while-little-toxic nanozymes.

The researchers showed that nanozymes that generate surface-bound ROS selectively kill bacteria, while leaving the mammalian cells safe.

The selectivity is attributed to, on the one hand, the surface-bound nature of ROS generated by the nanozymes prepared by the team, and on the other hand, an unexpected antidote role of endocytosis, a cellular process that is common for mammalian cells while absent in bacteria.

Feng Gao et al. Surface-bound reactive oxygen species generating nanozymes for selective antibacterial action, Nature Communications (2021). DOI: 10.1038/s41467-021-20965-3

https://phys.org/news/2021-03-nanozymes-antimicrobial-resistance.ht...

Comment by Dr. Krishna Kumari Challa on March 16, 2021 at 11:44am

Study finds cancer cells may evade chemotherapy by going dormant

Cancer cells can dodge chemotherapy by entering a state that bears similarity to certain kinds of senescence, a type of "active hibernation" that enables them to weather the stress induced by aggressive treatments aimed at destroying them, according to a new study by scientists.

These findings have implications for developing new drug combinations that could block senescence and make chemotherapy more effective.

The investigators reported that this biologic process could help explain why cancers so often recur after treatment. The research was done in both organoids and mouse models made from patients' samples of acute myeloid leukemia (AML) tumors. The findings were also verified by looking at samples from AML patients that were collected throughout the course of treatment and relapse.

Acute myeloid leukemia can be put into remission with chemotherapy, but it almost always comes back, and when it does it's incurable.

For years, cancer researchers have studied how tumors are able to rebound after they appear to be completely wiped out by chemotherapy. One theory has been that because not all cells within a tumor are the same at the genetic level—a condition called tumor heterogeneity—a small subset of cells are able to resist treatment and begin growing again. Another theory involves the idea of tumor stem cells—that some of the cells within a tumor have special properties that allow them to re-form a tumor after chemotherapy has been given. The idea that senescence is involved does not replace these other theories. In fact, it could provide new insight into explaining these other processes.

In the study, the researchers found that when AML cells were exposed to chemotherapy, a subset of the cells went into a state of hibernation, or senescence, while at the same time assuming a condition that looked very much like inflammation. They looked similar to cells that have undergone an injury and need to promote wound healing—shutting down the majority of their functions while recruiting immune cells to nurse them back to health.

"These characteristics are also commonly seen in developing embryos that temporarily shut down their growth due to lack of nutrition, a state called embryonic diapause. Further research revealed that this inflammatory senescent state was induced by a protein called ATR, suggesting that blocking ATR could be a way to prevent cancer cells from adopting this condition. The investigators tested this hypothesis in the lab and confirmed that giving leukemia cells an ATR inhibitor before chemotherapy prevented them from entering senescence, thereby allowing chemotherapy to kill all of the cells.

Importantly, studies published at the same time from two other groups reported that the role of senescence is important not just for AML, but for recurrent cases of breast cancer, prostate cancer and gastrointestinal cancers as well.

Cihangir Duy et al. Chemotherapy induces senescence-like resilient cells capable of initiating AML recurrence, Cancer Discovery (2021). DOI: 10.1158/2159-8290.CD-20-1375

https://medicalxpress.com/news/2021-03-cancer-cells-evade-chemother...

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