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Comment by Dr. Krishna Kumari Challa on February 12, 2021 at 7:41am

To find an extraterrestrial civilization, pollution could be the solution, NASA study suggests

If there's an advanced extraterrestrial civilization inhabiting a nearby star system, we might be able to detect it using its own atmospheric pollution, according to new NASA research. The study looked at the presence of nitrogen dioxide gas (NO₂), which on Earth is produced by burning fossil fuels but can also come from non-industrial sources such as biology, lightning, and volcanoes.

On Earth, most of the nitrogen dioxide is emitted from human activity—combustion processes such as vehicle emissions and fossil-fueled power plants. In the lower atmosphere (about 10 to 15 kilometers or around 6.2 to 9.3 miles), NO₂ from human activities dominate compared to non-human sources. Therefore, observing NO₂ on a habitable planet could potentially indicate the presence of an industrialized civilization.

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Astronomers have found over 4,000 planets orbiting other stars to date. Some might have conditions suitable for life as we know it, and on some of these habitable worlds, life may have evolved to the point where it produces a technological civilization. Since planets around other stars (exoplanets) are so far away, scientists cannot look for signs of life or civilization by sending spacecraft to these distant worlds. Instead, they must use powerful telescopes to see what's inside the atmospheres of exoplanets.

A possible indication of life, or biosignature, could be a combination of gases like oxygen and methane in the atmosphere. Similarly, a sign of technology on an exoplanet, called a technosignature, could be what's considered pollution here on Earth—the presence of a gas that's released as a byproduct of a widespread industrial process, such as NO₂.

This study is the first time NO₂ has been examined as a possible technosignature.

Other studies have examined chlorofluorocarbons (CFCs) as possible technosignatures, which are industrial products that were widely used as refrigerants until they were phased out because of their role in ozone depletion.

CFCs are also a powerful greenhouse gas that could be used to terraform a planet like Mars by providing additional warming from the atmosphere. As far as we know, CFCs are not produced by biology at all, so they are a more obvious technosignature than NO₂. However, CFCs are very specific manufactured chemicals that might not be prevalent elsewhere; NO₂, by comparison, is a general byproduct of any combustion process.

Atmospheric NO2 strongly absorbs some colors (wavelengths) of visible light, which can be detected by observing the light reflected from an exoplanet as it orbits its star. They found that for an Earth-like planet orbiting a Sun-like star, a civilization producing the same amount of NO₂ as ours could be detected up to about 30 light-years away with about 400 hours of observing time using a future large NASA telescope observing at visible wavelengths.

Nitrogen Dioxide Pollution as a Signature of Extraterrestrial Technology. arXiv:2102.05027v1 [astro-ph.EP] arxiv.org/abs/2102.05027

https://phys.org/news/2021-02-extraterrestrial-civilization-polluti...

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

Centipedes shown to have incorporated the weapons of bacteria and fungi into their venoms

As part of an ongoing, wider study into centipede venoms,  researchers set out to discover whether centipede venom toxins may have evolved elsewhere in the tree of life, in places other than their direct, arthropod ancestors.

They soon unveiled that centipedes have repeatedly stocked their venoms with proteins that independently evolved within bacteria and fungi. The centipedes have acquired these toxin components through a process known as 'horizontal gene transfer'.

Horizontal gene transfer is a process by which genetic material moves between distantly related organisms, in this case between bacteria and fungi, and centipedes. It is distinguished from the movement of genetic material from parents to offspring and from ancestors to direct descendants, which is known as vertical gene transfer.

This finding  reveals the largest, most diversely sourced contribution of horizontal gene transfer to the evolution of animal venom composition known to date.'

Three of the five venom protein families that centipedes have acquired by horizontal gene transfer are used by bacteria explicitly to exploit their hosts', including by damaging their cells by the formation of pores. 

Researchers also noticed "three protein families were each horizontally transferred twice which shows that horizontal gene transfer is an unexpectedly important factor in the evolution of centipede venoms." While the mechanisms behind horizontal gene transfer, especially from bacteria to animals, are not well understood, it is known to have contributed a range of adaptive benefits to different groups of animals.

https://natureecoevocommunity.nature.com/posts/phylogenetic-analyse...

https://www.nhm.ac.uk/press-office/press-releases/centipedes-shown-...

https://researchnews.cc/news/5071/Centipedes-shown-to-have-incorpor...

Comment by Dr. Krishna Kumari Challa on February 11, 2021 at 10:00am

New report  about people testing +ve after 14 day quarantine period. 

Over the past week, three returned travellers — one in New South Wales and two in Victoria — have tested positive to COVID-19 shortly after leaving hotel quarantine.

The cases in Victoria appear almost certainly to have been acquired in hotel quarantine. The individuals had quarantined at the Holiday Inn, where eight staff members and guests have been now infected. Authorities are investigating.

But genomic sequencing has now indicated the NSW case was not picked up in hotel quarantine. So it’s possible either the person was still shedding virus from an earlier infection they contracted overseas, or that they incubated the virus for longer than 14 days.

The incubation period is the time between the point at which someone is exposed to the virus and the onset of symptoms (bearing in mind of course that not everyone who tests positive to COVID-19 will develop symptoms).

Theoretically, it is possible for a person to incubate the virus for longer than 14 days.

Most people who are exposed to SARS-CoV-2, the virus that causes COVID-19, will not go on to develop an infection. Sometimes the dose is not high enough, and/or the person can mount a successful immune response to prevent the virus establishing itself in their system.

But of those who do develop an infection, the evidence suggests almost all will return a positive test within 14 days of being exposed to the virus. A review summarising data from 21 studies reported only 1% of people incubated the virus beyond two weeks.

For the small minority of people who incubate the virus beyond 14 days, this can be related to underlying conditions, especially those that weaken a person’s immune response.

https://theconversation.com/yes-a-16-day-incubation-period-for-covi...

Comment by Dr. Krishna Kumari Challa on February 11, 2021 at 9:50am

'Invisible killer': fossil fuels caused 8.7m deaths globally in 2018, research finds

Pollution from power plants, vehicles and other sources accounted for one in five of all deaths that year, more detailed analysis reveals.

Pollution from burning fossil fuels is responsible for an estimated 8.7 million pr.... A fresh analysis, based on data representative of conditions in 2018, looked at dangerous airborne particles produced by fossil fuels — especially coal, petrol and diesel. The findings double previous estimates of deaths from fine-particle pollution, despite fine-tuning the estimate to exclude dust and wildfire smoke. “We were initially very hesitant when we obtained the results because they are astounding,” says geographer Eloise Marais. “Some governments have carbon-neutral goals but maybe we need to move them forward given the huge damage to public health. We need much more urgency.”

https://www.sciencedirect.com/science/article/abs/pii/S001393512100...

https://www.theguardian.com/environment/2021/feb/09/fossil-fuels-po...

Comment by Dr. Krishna Kumari Challa on February 11, 2021 at 9:25am

New wearable device turns the body into a battery

Comment by Dr. Krishna Kumari Challa on February 11, 2021 at 9:19am

Plastic ingestion by fish a growing problem

The consumption of plastic by marine animals is an increasingly pervasive problem, with litter turning up in the bellies of wildlife as varied as mammals, birds, turtles and fish. However, according to a research review by ecologists, the problem is impacting species unevenly, with some more susceptible to eating a plastic dinner than others. With billions of people around the world relying on seafood for sustenance and financial security, this research, published Feb 9. in the journal Global Change Biology, warns that there is a growing number of species—including over 200 species of commercial importance—eating plastic.

database reveals the consumption of plastic by fish is widespread and increasing. Over the last decade, the rate of plastic consumption has doubled, increasing by 2.4 percent every year. Part of this is due to scientists' increasing ability to detect smaller particles of plastic than before. However, even when the researchers statistically controlled for improvements in methodology, they still found an overall increase in plastic consumption. Even more disconcerting, many new species of fish were discovered with plastic inside of them each year. The 210 species of fish that are caught commercially have been found to eat plastic, and this number is likely an underestimate, the researchers say.

Plastic ingestion by marine fish is widespread and increasing. Global Change Biology, doi.org/10.1111/gcb.15533

https://phys.org/news/2021-02-plastic-ingestion-fish-problem.html?u...

Comment by Dr. Krishna Kumari Challa on February 11, 2021 at 9:09am

Plant-based magnetic nanoparticles with antifungal properties

A team of researchers from Immanuel Kant Baltic Federal University obtained magnetic nanoparticles using sweet flag (Acorus calamus). Both the roots and the leaves of this plant have antioxidant, antimicrobial, and insecticide properties. The extract of sweet flag was used as a non-toxic reagent for the manufacture of coated particles. The authors of the work also showed the efficiency of the new nanoparticles against several types of pathogenic fungi that damage cultivated plants. A technology developed by the team provides for the manufacture of nanoparticles from a cheap plant-based raw material and reduces the harmful effect of reagents on the environment.

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Scientists detect water vapour emanating from Mars

Researchers said Wednesday they had observed water vapour escaping high up in the thin atmosphere of Mars, offering tantalising new clues as to whether the Red Planet could have once hosted life.

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New wearable device turns the body into a battery

Researchers at the University of Colorado Boulder have developed a new, low-cost wearable device that transforms the human body into a biological battery.

Comment by Dr. Krishna Kumari Challa on February 11, 2021 at 8:59am

Scientists create liquid crystals that look a lot like their solid counterparts

A research team  has designed new kinds of liquid crystals that mirror the complex structures of some solid crystals—a major step forward in building flowing materials that can match the colorful diversity of forms seen in minerals and gems, from lazulite to topaz.

The group's findings, published today in the journal Nature, may one day lead to new types of smart windows and television or computer displays that can bend and control light like never before.

The results come down to a property of solid crystals that will be familiar to many chemists and gemologists: Symmetry

DOI: 10.1038/s41586-021-03249-0 Wensink, H.H. et al. Thermally reconfigurable monoclinic nematic colloidal fluids. Nature 590, 268–274 (2021). doi.org/10.1038/s41586-021-03249-0

https://phys.org/news/2021-02-scientists-liquid-crystals-lot-solid....

Comment by Dr. Krishna Kumari Challa on February 11, 2021 at 8:55am

Imaging Habitable-Zone Exoplanets

Comment by Dr. Krishna Kumari Challa on February 11, 2021 at 8:50am

A new way to look for life-sustaining planets

It is now possible to capture images of planets that could potentially sustain life around nearby stars, thanks to advances reported by an international team of astronomers in the journal Nature Communications.

Using a newly developed system for mid-infrared exoplanet imaging, in combination with a very long observation time, the study's authors say they can now use ground-based telescopes to directly capture images of planets about three times the size of Earth within the habitable zones of nearby stars.

Efforts to directly image exoplanets—planets outside our solar system—have been hamstrung by technological limitations, resulting in a bias toward the detection of easier-to-see planets that are much larger than Jupiter and are located around very young stars and far outside the habitable zone—the "sweet spot" in which a planet can sustain liquid water. If astronomers want to find alien life, they need to look elsewhere.

"If we want to find planets with conditions suitable for life as we know it, we have to look for rocky planets roughly the size of Earth, inside the habitable zones around older, sun-like stars.

The method described in the paper provides more than a tenfold improvement over existing capabilities to directly observe exoplanets. Most studies on exoplanet imaging have looked in infrared wavelenghts of less than 10 microns, stopping just short of the range of wavelengths where such planets shine the brightest. There is a good reason for that because the Earth itself is shining at you at those wavelengths. Infrared emissions from the sky, the camera and the telescope itself are essentially drowning out your signal. But the good reason to focus on these wavelengths is that's where an Earthlike planet in the habitable zone around a sun-like star is going to shine brightest.

 Imaging low-mass planets within the habitable zone of Alpha; Centauri, Nature Communications (2021). DOI: 10.1038/s41467-021-21176-6

https://phys.org/news/2021-02-life-sustaining-planets.html?utm_sour...

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