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Comment by Dr. Krishna Kumari Challa on August 27, 2020 at 6:02am

Bacteria could survive travel between Earth and Mars under certain conditions

Imagine microscopic life-forms, such as bacteria, transported through space, and landing on another planet. The bacteria finding suitable conditions for its survival could then start multiplying again, sparking life at the other side of the universe. This theory, called "panspermia", support the possibility that microbes may migrate between planets and distribute life in the universe. Long controversial, this theory implies that bacteria would survive the long journey in outer space, resisting to space vacuum, temperature fluctuations, and space radiations.

Scientists now tested the survival of the radioresistant bacteria Deinococcus in space. The study shows that thick aggregates can provide sufficient protection for the survival of bacteria during several years in the harsh space environment.

They came to this conclusion by placing dried Deinococcus aggregates in exposure panels outside of the International Space Station (ISS). The samples of different thicknesses were exposed to space environment for one, two, or three years and then tested for their survival.

After three years, the researchers found that all aggregates superior to 0.5 mm partially survived to space conditions. Observations suggest that while the bacteria at the surface of the aggregate died, it created a protective layer for the bacteria beneath ensuring the survival of the colony. Using the survival data at one, two, and three years of exposure, the researchers estimated that a pellet thicker than 0.5 mm would have survived between 15 and 45 years on the ISS. The design of the experiment allowed the researcher to extrapolate and predict that a colony of 1 mm of diameter could potentially survive up to 8 years in outer space conditions.

The results suggest that radioresistant Deinococcus could survive during the travel from Earth to Mars and vice versa, which is several months or years in the shortest orbit

Yuko Kawaguchi et al, DNA Damage and Survival Time Course of Deinococcal Cell Pellets During 3 Years of Exposure to Outer Space, Frontiers in Microbiology (2020). DOI: 10.3389/fmicb.2020.02050

https://phys.org/news/2020-08-bacteria-survive-earth-mars-aggregate...

Comment by Dr. Krishna Kumari Challa on August 27, 2020 at 5:49am

How plants tackle infection

Plants have a unique ability to safeguard themselves against pathogens by closing their pores—but until now, no one knew quite how they did it. Scientists have known that a flood of calcium into the cells surrounding the pores triggers them to close, but how the calcium entered the cells was unclear.

After a new study scientists reveal that a protein called OSCA1.3 forms a channel that leaks calcium into the cells surrounding a plant's pores, and they determined that a known immune system protein triggers the process.

"The calcium-permeable channel OSCA1.3 regulates plant stomatal immunity," Nature (2020). dx.doi.org/10.1038/s41586-020-2702-1

https://phys.org/news/2020-08-door-infection.html?utm_source=nwlett...

Comment by Dr. Krishna Kumari Challa on August 27, 2020 at 5:44am

Microscopic robots 'walk' thanks to laser tech

https://techxplore.com/news/2020-08-microscopic-robots-laser-tech.h...

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Meteorite strikes may create unexpected form of silica

When a meteorite hurtles through the atmosphere and crashes to Earth, how does its violent impact alter the minerals found at the landing site? What can the short-lived chemical phases created by these extreme impacts teach scientists about the minerals existing at the high-temperature and pressure conditions found deep inside the planet?

Quartz is made up of one silicon atom and two oxygen atoms arranged in a tetrahedral lattice structure. Because these elements are also common in the silicate-rich mantle of the Earth, discovering the changes quartz undergoes at high-pressure and -temperature conditions, like those found in the Earth's interior, could also reveal details about the planet's geologic history.

When a material is subjected to extreme pressures and temperatures, its internal atomic structure can be re-shaped, causing its properties to shift. For example, both graphite and diamond are made from carbon. But graphite, which forms at low pressure, is soft and opaque, and diamond, which forms at high pressure, is super-hard and transparent. The different arrangements of carbon atoms determine their structures and their properties, and that in turn affects how we engage with and use them.

when subjected to a dynamic shock of greater than 300,000 times normal atmospheric pressure, quartz undergoes a transition to a novel disordered crystalline phase, whose structure is intermediate between fully crystalline stishovite and a fully disordered glass. However, the new structure cannot last once the burst of intense pressure has subsided.

"Structural response of α-quartz under plate-impact shock compression" Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abb3913

https://phys.org/news/2020-08-meteorite-unexpected-silica.html?utm_...

Comment by Dr. Krishna Kumari Challa on August 27, 2020 at 5:43am

Cosmic rays may soon hinder the progress of quantum computing

The practicality of quantum computing hangs on the integrity of the quantum bit, or qubit. That  depends on a qubit's integrity, or how long it can operate before its superposition and the quantum information are lost—a process called decoherence, which ultimately limits the computer run-time. Superconducting qubits—a leading qubit modality today—have achieved exponential improvement in this key metric, from less than one nanosecond in 1999 to around 200 microseconds today for the best-performing devices.

have found that a qubit's performance will soon hit a wall. In a paper published in Nature, the team reports that the low-level, otherwise harmless background radiation that is emitted by trace elements in concrete walls and incoming cosmic rays are enough to cause decoherence in qubits. They found that this effect, if left unmitigated, will limit the performance of qubits to just a few milliseconds. 

 There are many sources of decoherence that could destabilize a qubit, such as fluctuating magnetic and electric fields, thermal energy, and even interference between qubits.

Scientists have long suspected that very low levels of radiation may have a similar destabilizing effect in qubits.

In new experiments scientists found this is true and shielding improved qubit performance.

Source: Impact of ionizing radiation on superconducting qubit coherence, Nature (2020). DOI: 10.1038/s41586-020-2619-8 , www.nature.com/articles/s41586-020-2619-8

https://phys.org/news/2020-08-cosmic-rays-stymie-quantum.html?utm_s...

Comment by Dr. Krishna Kumari Challa on August 26, 2020 at 8:12am

Scientific research video

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crazy science

Comment by Dr. Krishna Kumari Challa on August 26, 2020 at 5:52am

New treatments aim to treat COVID-19 early, before it gets serious

https://www.sciencenews.org/article/coronavirus-covid-19-new-early-...

Some promising treatments may block the coronavirus from entering cells or from multiplying

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Disease Tolerance: Why Do Some People Weather Coronavirus Infection Unscathed?

https://www.scientificamerican.com/article/why-do-some-people-weath...

https://undark.org/2020/08/24/covid-19-infection-asymptomatic/

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Two major microbial groups living deep underground can't breathe

A new scientific study has revealed unique life strategies of two major groups of microbes that live below Earth's surface. These groups, originally thought to rely on symbiotic relationships with other organisms, may also live independently and use an ancient mode of energy production.

https://www.sciencedaily.com/releases/2020/08/200825110626.htm

Comment by Dr. Krishna Kumari Challa on August 26, 2020 at 5:44am

Reverse dieting: slowly increasing calories won’t prevent weight regain – but may have other benefits

https://theconversation.com/reverse-dieting-slowly-increasing-calor...  

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India is key for global access to a COVID-19 vaccine – here’s why

https://theconversation.com/india-is-key-for-global-access-to-a-cov...  

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Cold-Causing Coronaviruses Don’t Seem to Confer Lasting Immunity

Studies on SARS-CoV-2’s milder cousins hint that our immune systems are quick to forget the viruses, but it’s unclear whether the same is true for the agent that causes COVID-19.

https://www.the-scientist.com/news-opinion/cold-causing-coronavirus...

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The puzzle in measurement of positronium’s energy levels

A new measurement of the exotic “atom” — consisting of an electron and its antiparticle, a positron — disagrees with theoretical calculations, scientists report

Positronium is composed of an electron, with a negative charge, circling in orbit with a positron, with a positive charge — making what’s effectively an atom without a nucleus (SN: 9/12/07). With just two particles and free from the complexities of a nucleus, positronium is appealingly simple. Its simplicity means it can be used to precisely test the theory of quantum electrodynamics, which explains how electrically charged particles interact.

https://www.sciencenews.org/article/positronium-energy-levels-exoti...

Comment by Dr. Krishna Kumari Challa on August 26, 2020 at 5:32am

Ancient star explosions revealed in the deep sea

A mystery surrounding the space around our solar system is unfolding thanks to evidence of supernovae found in deep-sea sediments.

A new study  shows the Earth has been traveling for the last 33,000 years through a cloud of faintly radioactive dust.

These clouds could be remnants of previous supernova explosions, a powerful and super bright explosion of a star.

The researchers searched through several deep-sea sediments from two different locations that date back 33,000 years using the extreme sensitivity of HIAF's mass spectrometer. They found clear traces of the isotope iron-60, which is formed when stars die in supernova explosions.

Iron-60 is radioactive and completely decays away within 15 million years, which means any iron-60 found on the earth must have been formed much later than the rest of the 4.6-billion-year old earth and arrived here from nearby supernovae before settling on the ocean floor.

found traces of iron-60 at about 2.6 million years ago, and possibly another at around 6 million years ago, suggesting earth had traveled through fallout clouds from nearby supernovae.

For the last few thousand years the solar system has been moving through a denser cloud of gas and dust, known as the local interstellar cloud, (LIC), whose origins are unclear. If this cloud had originated during the past few million years from a supernova, it would contain iron-60, and so the team decided to search more recent sediment to find out.

Sure enough, there was iron-60 in the sediment at extremely low levels—equating to radioactivity levels in space far below the Earth's natural background levels—and the distribution of the iron-60 matched earth's recent travel through the local interstellar cloud. But the iron-60 extended further back and was spread throughout the entire 33,000 year measurement period.

The lack of correlation with the solar system's time in the current local interstellar cloud seems to pose more questions than it answers. Firstly, if the cloud was not formed by a supernova, where did it come from? And secondly, why is there iron-60 so evenly spread throughout space?

There are recent papers that suggest iron-60 trapped in dust particles might bounce around in the interstellar medium.

So the iron-60 could originate from even older supernovae explosions, and what we measure is some kind of echo. More data is required to resolve these details.

A. Wallner et al. 60Fe deposition during the late Pleistocene and the Holocene echoes past supernova activity, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.1916769117

https://phys.org/news/2020-08-ancient-star-explosions-revealed-deep...

Comment by Dr. Krishna Kumari Challa on August 26, 2020 at 5:27am

Galactic bar paradox resolved in cosmic dance

New light has been shed on a mysterious and long-standing conundrum at the very heart of our galaxy. The new work offers a potential solution to the so-called "Galactic bar paradox," whereby different observations produce contradictory estimates of the motion of the central regions of the Milky Way.

The majority of spiral galaxies, like our home the Milky Way, host a large bar-like structure of stars in their center. Knowledge of the true bar size and rotational speed is crucial for understanding how galaxies form and evolve, as well as how they form similar bars throughout the universe.

However our galaxy's bar size and rotational speed have been strongly contested in the last 5 years; while studies of the motions of stars near the Sun find a bar that is both fast and small, direct observations of the Galactic central region agree on one that is significantly slower and larger.

The new study, by an international team of scientists suggests an insightful solution to this discrepancy. Analyzing state-of-the-art galaxy formation simulations of the Milky Way, they show that both the bar's size and its rotational speed fluctuate rapidly in time, causing the bar to appear up to twice as long and rotate 20 percent faster at certain times.

The bar pulsations result from its regular encounters with the Galactic spiral arms, in what can be described as a "cosmic dance." As the bar and spiral arm approach each other, their mutual attraction due to gravity makes the bar slow down and the spiral speed up. Once connected, the two structures move as one and the bar appears much longer and slower than it actually is. As the dancers split apart, the bar speeds up while the spiral slows back down.

T Hilmi et al. Fluctuations in galactic bar parameters due to bar–spiral interaction, Monthly Notices of the Royal Astronomical Society (2020). DOI: 10.1093/mnras/staa1934

https://phys.org/news/2020-08-galactic-bar-paradox-cosmic.html?utm_...

Comment by Dr. Krishna Kumari Challa on August 26, 2020 at 5:10am

New imaging technique helps resolve nanodomains, chemical composition in cell membranes

Jin Lu et al. Single‐Molecule 3D Orientation Imaging Reveals Nanoscale Compositional Heterogeneity in Lipid Membranes, Angewandte Chemie International Edition (2020). DOI: 10.1002/anie.202006207

https://phys.org/news/2020-08-imaging-technique-nanodomains-chemica...

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Nanoengineered biosensors for early disease detection

Researchers have developed a cheaper, faster and ultrasensitive biosensors that use nanoengineered porous gold which more effectively detect early signs of disease, improving patient outcomes. This new diagnostic technique allows for direct detection of disease-specific miRNA, which wasn't previously possible.

This is especially important for patients at an early stage of a disease such as cancer, who do not have detectable amounts of other biomarkers, but may have a detectable quantity of exosomal miRNA biomarker.

The platform was nanoengineered by the team to read samples of blood, urine, saliva or plasma through a surface covered in a gold film, which has millions of tiny pores.

Hyunsoo Lim et al. A universal approach for the synthesis of mesoporous gold, palladium and platinum films for applications in electrocatalysis, Nature Protocols (2020). DOI: 10.1038/s41596-020-0359-8

https://phys.org/news/2020-08-nanoengineered-biosensors-early-disea...

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Physicists discover new two-dimensional ferroelectric material just two atoms thick

Two-dimensional materials are ultrathin membranes that hold promise for novel optoelectronic, thermal, and mechanical applications, including ultra-thin data-storage devices that would be both foldable and information dense.

Ferroelectric materials are those with an intrinsic dipole moment—a measure of the separation of positive and negative charges—that can be switched by an electric field.

Salvador Barraza-Lopez et al. Water Splits To Degrade Two-Dimensional Group-IV Monochalcogenides in Nanoseconds, ACS Central Science (2018). DOI: 10.1021/acscentsci.8b00589

https://phys.org/news/2020-08-physicists-two-dimensional-material.h...

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