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Comment by Dr. Krishna Kumari Challa on March 18, 2021 at 11:22am

As endangered birds lose their songs, they can't find mates

Male songbirds usually learn their tunes from adult mentors. But when aspiring crooners lack proper role models, they hit all the wrong notes—and have less success attracting mates.

For five years, ecologist Ross Crates has tracked the singing ability and breeding success of critically endangered regent honeyeaters. These distinctive black and yellow birds were once common across Australia, but habitat loss since the 1950s has shrunk their population to only about 300 or 400 wild birds today.

While male birds once formed large winter flocks, now they are sparsely distributed across the landscape, so many fly solo. That means fewer honeyeater mentors are nearby during young birds' impressionable first year.

Song learning in many birds is a process similar to humans learning languages—they learn by listening to other individuals. If you can't listen to other individuals, you don't know what you should be learning.

The researchers found that a significant portion of male birds appear to be learning tunes exclusively from other species they encounter. About 12% of male regent honeyeaters wind up producing mangled versions of songs typically sung by noisy friarbirds and black-faced cuckooshrikes, among other species.

In some species, such as mockingbirds, song mimicry adds flourish to love songs. But the female regent honeyeaters aren't impressed.

Unconventional male singers were less successful in wooing mates, the scientists found in research published Tuesday in the journal Proceedings of the Royal Society B. "We think the females are avoiding breeding and nesting with males that sing unusual songs.

For a population already on the brink of extinction, that's worrisome.

"This research suggests that the loss of a song language once the population reaches a very small size could accelerate their decline

It could be that female honeyeaters aren't even recognizing these unconventional singers as potential partners, and so they're not approaching them. Or it could be that they approach, "but then things go wrong if the males get courtship signals wrong."

Hit the wrong note - Loss of vocal culture and fitness costs in a critically endangered songbird, Proceedings of the Royal Society B (2021). rspb.royalsocietypublishing.or … .1098/rspb.2021.0225

https://phys.org/news/2021-03-honeyeaters-wrong-song.html?utm_sourc...

Comment by Dr. Krishna Kumari Challa on March 18, 2021 at 11:11am

Scientists create model of an early human embryo from skin cells

In a discovery that will revolutionize research into the causes of early miscarriage, infertility and the study of early human development—an international team of scientists led by Monash University in Melbourne, Australia has generated a model of a human embryo from skin cells.

The team, led by Professor Jose Polo, has successfully reprogrammed these fibroblasts or skin cells into a 3-dimensional cellular structure that is morphologically and molecularly similar to human blastocysts. Called iBlastoids, these can be used to model the biology of early human embryos in the laboratory.

The achievement is a significant breakthrough for the future study of early human development and infertility. To date, the only way to study these first days has been through the use of difficult to obtain, and scarce, blastocysts obtained from IVF procedures.

Modelling human blastocysts by reprogramming fibroblasts into iBlastoids, Nature (2021). DOI: 10.1038/s41586-021-03372-y

https://phys.org/news/2021-03-scientists-early-human-embryo-skin.ht...

Comment by Dr. Krishna Kumari Challa on March 17, 2021 at 9:47am

Lightning strikes played a vital role in life's origins on Earth: study

Lightning strikes were just as important as meteorites in creating the perfect conditions for life to emerge on Earth, geologists say.

Minerals delivered to Earth in meteorites more than 4 billion years ago have long been advocated as key ingredients for the development of life on our planet.

Scientists thought  minimal amounts of these minerals were also brought to early Earth through billions of lightning strikes.

But now researchers  have established that lightning strikes were just as significant as meteorites in performing this essential function and allowing life to manifest.

They say this shows that life could develop on Earth-like planets through the same mechanism at any time if atmospheric conditions are right. 

 Lightning strikes as a major facilitator of prebiotic phosphorus reduction on early Earth, Nature Communications (2021). DOI: 10.1038/s41467-021-21849-2 , dx.doi.org/10.1038/s41467-021-21849-2

https://phys.org/news/2021-03-life-earth-blue.html?utm_source=nwlet...

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

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