Comment

Comment by Dr. Krishna Kumari Challa on March 25, 2022 at 11:10am

Study: Sickle Cell Mutation Driven by Pressure, Not Random Chance

New research finds that the appearance of the HbS mutation, which protects against malaria but leads to sickle cell disease when present in two copies, was more common in sperm samples from men in Ghana, where malaria risk is high, than Europeans.

New research challenges the overarching assumption that genetic mutations occur randomly and are then either kept or discarded by natural selection. In the study, published January 14 in Genome Research, scientists found that the rate of a specific mutation with important health implications is nonrandom, occurring more or less often in different populations that have experienced specific environmental pressures over the course of generations.

analyzed tens to hundreds of millions of sperm cells from each of seven donors from Ghana and four from Europe, comparing how often mutations occurred in regions of two hemoglobin subunit genes in each group. They found that the hemoglobin S (HbS) mutation of the hemoglobin subunit beta (HBB) gene, which is known to protect against malaria but causes sickle cell disease when two copies are present, occurred more often in samples from the African cohort than the European one, while mutations to the similar and nearby gene for the delta subunit, which isn’t protective against malaria, did not.

Because the study focused on sperm samples, which are equivalent to a single generation, natural selection and genetic drift had no influence on the prevalence of mutations.  And given the medical importance of the mutation exhibiting increased occurrence in the African cohort, the results raise a fundamental challenge to the notion of random mutation.

These  differences in mutation rates can be occurring down to very fine resolution, that they can differ between populations, and that could help explain evolutionary processes like adaptation to disease.

However, Other researchers in the field aren’t entirely convinced by the study’s big-picture conclusions about the nature of evolution, though they were impressed by the technological advancement it represents.

https://www.the-scientist.com/news-opinion/study-sickle-cell-mutati...

**

Comment by Dr. Krishna Kumari Challa on March 25, 2022 at 10:22am

 Flies can be used to detect use of chemical weapons, other pollutants

Researchers  have found that blow flies can be used as chemical sensors, with a particular focus on the detection of chemical warfare agents.

Despite widespread bans, it is alleged that chemical have been deployed in some of the recent conflicts.

 

A new study shows that blow flies could be used as a safer alternative for investigating the use of these weapons—as well as other chemicals in the environment—keeping humans out of potentially dangerous situations.

The work appears in the journal Environmental Science and Technology.

Blow flies are ubiquitous, and they are very adept at sampling the environment around us. They will fly through the environment, taste it, and that information will be stored in their guts. Through a series of experiments, researchers  were able to look at how different environmental factors would impact their detection of chemical weapon simulants.

A mass spectrometer can be used to determine what chemicals were in the blow flies' guts after they fly through a dangerous environment.

While chemical warfare agents do not persist for long in the environment, the researchers found they're preserved well enough in the fly's guts for chemical analysis. They also were able to detect the chemical warfare agent simulants up to 14 days after a fly's initial exposure—illustrating a safer alternative for the collection of samples, without risking human lives.

Sarah N. Dowling et al, Insects as Chemical Sensors: Detection of Chemical Warfare Agent Simulants and Hydrolysis Products in the Blow Fly Using LC-MS/MS, Environ. Sci. Technol. (2022). doi.org/10.1021/acs.est.1c07381

https://phys.org/news/2022-03-flies-chemical-weapons-pollutants.htm...

Comment by Dr. Krishna Kumari Challa on March 25, 2022 at 10:07am

Why flush toilets are wasteful 

Power-free frequency tuner

Comment by Dr. Krishna Kumari Challa on March 25, 2022 at 10:01am

Despite its slow pace, land subsidence is known to cause losses worth billions of dollars all over the world due to damage to infrastructure, roads, pavements, and underground utilities such as drainage systems, aggravated flood risks and more frequent water-logging.

 Shagun Garg, Mahdi Motagh, J. Indu and Vamshi Karanam, Tracking hidden crisis in India's capital from space: implications of unsustainable groundwater use, Scientific Reports (2022). DOI: 10.1038/s41598-021-04193-9

https://phys.org/news/2022-03-hidden-subsidence-crisis-india-capita...

Part 2

Comment by Dr. Krishna Kumari Challa on March 25, 2022 at 10:00am

Hidden land subsidence crisis in Delhi unveiled using satellite data

Using satellite data, researchers have found that around 100 sq km in and around Delhi has high risk of land subsidence. Groundwater extraction is causing parts of the city to sink, with the largest area experiencing subsidence just 800m away from Delhi international airport.

Land subsidence is a severe often overlooked geological hazard and is a widespread global problem. It can be attributed to underground extraction of minerals, oil, gas and water, as well as natural events such as soil compaction, earthquake, and loess deposits. According to U.S. Geological Survey, more than 80% of land subsidence across the world is caused due to excessive groundwater extraction. When water is extracted from aquifers, the clay between pockets of water collapse gradually, leading to land subsidence.

A study titled "Tracking hidden crisis in India's capital from space: implications of unsustainable groundwater use," published in Scientific Reports co-authored by researchers from IIT Bombay, German Research Centre for Geosciences, University of Cambridge and the Southern Methodist University US have found that the rate of land subsidence near Delhi airport is accelerating rapidly.

During the years 2014–2016, the subsidence was found to be approximately 11cm/year which rose significantly by almost 50% over the next two years to around 17cm/year. The trend remained almost the same during 2018–2019, the study found.

The airport requires stable ground because of the risk of major disruption if there's significant ground movement," Garg said. "Kuala Lumpur airport is an example to understand the implications of land subsidence where cracks on taxiways, and water-logging emerged due to soil settlement. Continuous monitoring of Delhi International airport and its connecting roads is therefore crucial."

The growing population expansion and urbanization require an enormous amount of water to fulfill the demand. There is a huge gap of 750 million liters a day between the demand and the supply. Millions of residents do not have access to a piped water supply and rely on groundwater for their daily needs. In some places, the water depth is as high as 120m below ground level. The groundwater shortage is further complicated by Delhi's unchecked urbanization, which is disrupting the rejuvenation of the city's aquifers. Concrete and other infrastructure have overtaken the city, blocking rainwater from absorbing into the ground.

Part 1

Comment by Dr. Krishna Kumari Challa on March 24, 2022 at 8:58am

Research:humans have given wild animals their diseases nearly 100 times

An international research team has found that humans might give viruses back to animals more often than previously understood.

In a study published March 22 in Ecology Letters ("Assessing the risk of human-to-wildlife pathogen transmission for conservation and public health"), the authors describe nearly one hundred different cases where diseases have undergone "spillback" from humans back into wild animals, much like how SARS-CoV-2 has been able to spread in mink farms, zoo lions and tigers, and wild white-tailed deer.

In their new study, Albery and colleagues found that almost half of the incidents identified occurred in captive settings like zoos, where veterinarians keep a close eye on animals' health and are more likely to notice when a virus makes the jump. Additionally, more than half of cases they found were human-to-primate transmission, an unsurprising result both because pathogens find it easier to jump between closely-related hosts, and because wild populations of endangered great apes are so carefully monitored.

Disease spillback has recently attracted substantial attention due to the spread of SARS-CoV-2, the virus that causes COVID-19, in wild white-tailed deer in the United States and Canada. Some data suggest that deer have given the virus back to humans in at least one case, and many scientists have expressed broader concerns that new animal reservoirs might give the virus extra chances to evolve new variants.

Assessing the risk of human-to-wildlife pathogen transmission for conservation and public health, Ecology Letters (2022).

https://phys.org/news/2022-03-humans-wild-animals-diseases.html?utm...

Comment by Dr. Krishna Kumari Challa on March 23, 2022 at 8:20am

These countries have the most polluted air in the world, new report says

Not a single country met the World Health Organization's quality for air in 2021, a new study suggested. And consequently, millions are breathing polluted air that does not satisfy WHO health guidelines, according to the report that analyzed real-time air quality of 6,475 cities.

Bangladesh was the most polluted country, while New Delhi, India, is the world's most polluted capital. The countries with the worst air pollution were India, Pakistan and Bangladesh, all exceeding WHO guidelines by 10 times.

Air pollution is considered the largest environmental threat, leading to 7 million deaths per year and other respiratory problems such as asthma and lung cancer

The top 10 best air quality countries or regions

1. New Caledonia
2. U.S Virgin Islands
3. Puerto Rico
4. Cape Verde
5. Saba
6. Finland
7. Grenada
8. Bahamas
9. Australia
10. Estonia

The top 10 worst air quality countries or regions

1. Bangladesh
2. Chad
3. Pakistan
4. Tajikistan
5. India
6. Oman
7. Kyrgyzstan
8. Bahrain
9. Iraq
10. Nepal

Source: Various News Agencies

https://phys.org/news/2022-03-countries-polluted-air-world.html?utm...

Comment by Dr. Krishna Kumari Challa on March 23, 2022 at 8:13am

New Lightweight Coating to Reduce Wood Flammability

https://phys.org/news/2022-03-wooden-materials-fire-resistant-eco-f...

----
What are the Trojan Asteroids?

Comment by Dr. Krishna Kumari Challa on March 23, 2022 at 8:07am

Researchers store a quantum bit for a record-breaking 20 milliseconds

Computers, smartphones, GPS: quantum physics has enabled many technological advances. It is now opening up new fields of research in cryptography (the art of coding messages) with the aim of developing ultra-secure telecommunications networks. There is one obstacle, however: after a few hundred kilometers within an optical fiber, the photons that carry the qubits or "quantum bits" (the information) disappear. They therefore need "repeaters," a kind of "relay," which are partly based on a quantum memory. By managing to store a qubit in a crystal (a "memory") for 20 milliseconds, a research team  has set a world record and taken a major step towards the development of long-distance quantum telecommunications networks. This research can be found in the journal npj Quantum Information.

Antonio Ortu et al, Storage of photonic time-bin qubits for up to 20 ms in a rare-earth doped crystal, npj Quantum Information (2022). DOI: 10.1038/s41534-022-00541-3

https://phys.org/news/2022-03-quantum-bit-fora-record-breaking-mill...

Comment by Dr. Krishna Kumari Challa on March 22, 2022 at 12:24pm

You Don't Actually Know How Water Works

• ‹ Previous
• 1
• …
• 498
• 499
• 500
• 501
• 502
• …
• 1070
• Next ›
• Page