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Comment by Dr. Krishna Kumari Challa on August 7, 2021 at 11:58am

Environmental impact of bottled water up to 3,500 times higher than tap water

The consumption of bottled water has been increasing sharply in recent years on a global scale. According to previous research, this trend can be partly explained by subjective factors like risk perception, taste, odor, lack of trust in public tap water quality and marketing by bottled water companies.

Environmental and health impacts are usually assessed separately due to the different methodologies applied and resulting outcomes. Environmental impacts can be estimated with a methodology called Life Cycle Assessment (LCA), while the consequences in human helath are estimated with an approach called Health Impact Assessment (HIA). This study has tried to overcome this methodological barrier for the first time by combining LCA and HIA in the same analysis.

The results of work done in Barcelona, Spain, showed that if the whole population of the city decided to shift to bottled water, the production required would take a toll of 1.43 species lost per year and cost of 83.9 million USD per year due to extraction of raw materials. This is approximately 1,400 times more impact in ecosystems and 3,500 times higher cost of resource extraction compared to the scenario where the whole population would shift to tap water.

The results results show that considering both the environmental and the health effects, tap water is a better option than bottled water, because bottled water generates a wider range of impacts.

Cristina M. Villanueva et al, Health and environmental impacts of drinking water choices in Barcelona, Spain: A modelling study, Science of The Total Environment (2021). DOI: 10.1016/j.scitotenv.2021.148884

https://phys.org/news/2021-08-environmental-impact-bottled-higher.h...

Comment by Dr. Krishna Kumari Challa on August 7, 2021 at 11:14am

Out of five promising antibodies that they isolated, the scientists decided to concentrate on one designated S2P6. Molecular structure analysis and functional studies showed that this human monoclonal antibody had impressive breadth: it was able to neutralize three different subgenera of beta-coronaviruses. The scientists observed that it did so by inhibiting the virus' ability to fuse with cell membranes.

The researchers went on to test if the S2P6 stem helix antibody could protect against SARS-CoV-2 by administering it to hamsters 24 hours before exposure. They found that this antibody reduced the viral load of SARS-CoV-2 by inhibiting entry of the virus and by enhancing additional anti-viral and virus-clearing cellular immune responses.

Studies of the plasma from pre-pandemic human samples, as well as from COVID-vaccinated and COVID-recovered individuals were also analyzed to see how frequently the stem-helix targeting antibodies appeared. They highest frequencies occurred in people who had recovered from COVID-19, then were later vaccinated. Overall, however, the data from this study shows that, while it does occur, it is relatively rare for SARS-CoV-2 to elicit plasma stem-helix antibody responses. The researchers hope that additional studies might reveal whether this is the case for antibodies that target other parts of the coronavirus fusion machinery or only for those that target the stem helix.

The researchers also looked at how the broadly reactive monoclonal antibodies studied in this project might have originated. Their findings suggest that they may have resulted from the priming of B memory cells through one of the common cold-inducing coronaviruses. Then the virus-specific B cells gained cross-reactivity through somatic mutations occurring during the body's immune response to a natural infection with another type of coronavirus.

The results from this study indicate that eliciting a sufficient quantity of stem helix antibodies through a standard vaccination development approach likely would be difficult. However, the researchers propose that recent computational protein-design advances for potential vaccine candidates against respiratory syncytial viruses and multiple influenza viruses might be adapted to try to induce broad beta coronavirus immunity and overcome the pan-coronavirus vaccine challenge.

Dora Pinto et al, Broad betacoronavirus neutralization by a stem helix–specific human antibody, Science (2021). DOI: 10.1126/science.abj3321

https://medicalxpress.com/news/2021-08-antibody-ideas-pan-coronavir...

Comment by Dr. Krishna Kumari Challa on August 7, 2021 at 11:13am

Antibody findings spark ideas for pan-coronavirus vaccine

Three epidemic or pandemic coronaviruses—SARS-CoV, MERS-CoV, & SARS-CoV-2—have spilled over from animals to cause deadly illness in humans in the past 20 years. Virus researchers are determined to discover a means to broadly safeguard people from the continuing threat of emerging coronaviruses.

Clues for creating such an overarching countermeasure might come from a rare type of human antibody that can neutralize several different coronaviruses. These antibodies have been detected in some people who have recovered from COVID-19.

A paper appearing Aug. 3 in the journal Science describes research on five such human monoclonal antibodies that can cross-react with a number of beta-coronaviruses. These antibodies target a structure, called stem helix, in the spike protein of these viruses. The spike protein is critical to the virus' ability to overtake host cells.

The stem helix in the spike protein has remained conserved during the evolution of certain coronaviruses. That means it is much less prone to genetic changes and is similar in various coronaviruses. These include those originating in bats that have become dangerous pathogens in people, and another subgenus that causes a serious human lung disease transmitted by dromedary camels, as well as a few other subgenera that cause simple common cold symptoms.

The researchers explain in their paper that they were interested in exploring antibodies that target highly conserved regions of the spike protein machinery that enable coronaviruses to fuse with the membrane of host cells. 

An antibody's ability to bind to the less mutable fusion machinery is what allows it to neutralize distantly related coronaviruses.

To find these sorts of antibodies, the researchers examined certain memory B cells from COVID-19 convalescent donors. Memory B cells are white blood cells that recognize and respond to pathogens that have tried to attack the body during a previous encounter.

part 1

Comment by Dr. Krishna Kumari Challa on August 6, 2021 at 10:51am

Using two CRISPR enzymes, a COVID diagnostic in only 20 minutes

Frequent, rapid testing for COVID-19 is critical to controlling the spread of outbreaks, especially as new, more transmissible variants emerge.

A research team is aiming to develop a diagnostic test that is much faster and easier to deploy than qRT-PCR. It has now combined two different types of CRISPR enzymes to create an assay that can detect small amounts of viral RNA in less than an hour.

While the new technique is not yet at the stage where it rivals the sensitivity of qRT-PCR, which can detect just a few copies of the virus per microliter of liquid, it is already able to pick up levels of viral RNA—about 30 copies per microliter—sufficient to be used to surveil the population and limit the spread of infections.

Liu, T.Y. et al. Accelerated RNA detection using tandem CRISPR nucleases. Nat Chem Biol (2021). DOI: 10.1038/s41589-021-00842-2

https://phys.org/news/2021-08-crispr-enzymes-covid-diagnostic-minut...

Comment by Dr. Krishna Kumari Challa on August 6, 2021 at 10:48am

When faces are partially covered, neither people nor algorithms are...

Artificial systems such as homecare robots or driver-assistance technology are becoming more common, and it's timely to investigate whether people or algorithms are better at reading emotions, particularly given the added challenge brought on by face coverings.

Comment by Dr. Krishna Kumari Challa on August 6, 2021 at 10:45am

Microwaving an ambulance. New technique could revolutionise how surfaces are disinfected
Microwave engineers, infectious disease specialists and polymer scientists have teamed up to create a novel microwave sterilization method that could revolutionize the way ambulances and hospitals are being disinfected.
At present, sterilization is done manually with conventional techniques that use chemicals. This can take around 30 to 40 minutes to disinfect a single ambulance.

During this time, the ambulance is out of action which puts increasing pressure on emergency services during busy times. The possibility of the new technique could drastically reduce the time it takes to get an ambulance safely back on the road to save lives.

In recent years, several other techniques have been proposed for disinfecting and sterilizing surfaces, ranging from hydrogen peroxide aerosols to UV irradiation and infrared radiation. However, these techniques have been shown to degrade surfaces over time, or to be harmful to humans if they are in close proximity. This has, so far, limited their long-term application.

In contrast, the new method works using electromagnetic waves, antennas, sensor beacons, and a liquid layer to rapidly heat-up and sterilize surfaces. Its automation means a person can easily operate the system from a safe distance rather than touching contaminated surfaces directly during cleaning.
The study used microwave beams emanating from antennas like those found in mobile smart phones and domestic Wi-Fi systems. The antennas allow the microwave radiation to be directed and focussed on locations where it is most needed.
K. Kossenas et al, A Methodology for Remote Microwave Sterilization Applicable to the Coronavirus and Other Pathogens using Retrodirective Antenna Arrays, IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology. DOI: 10.1109/JERM.2021.3077110
https://techxplore.com/news/2021-08-microwave-ambulance-technique-r...

Comment by Dr. Krishna Kumari Challa on August 6, 2021 at 10:22am

Tips to tackle plastic pollution

Comment by Dr. Krishna Kumari Challa on August 6, 2021 at 10:07am

Unsurprisingly, the theoretical speed limit for sending information in a quantum device (such as a quantum computer) depends on the device's underlying structure. The new protocol is designed for quantum devices where the basic building blocks—qubits—influence each other even when they aren't right next to each other. In particular, the team designed the protocol for qubits that have interactions that weaken as the distance between them grows. The new protocol works for a range of interactions that don't weaken too rapidly, which covers the interactions in many practical building blocks of quantum technologies, including nitrogen-vacancy centers, Rydberg atoms, polar molecules and trapped ions.

Crucially, the protocol can transfer information contained in an unknown quantum state to a distant qubit, an essential feature for achieving many of the advantages promised by quantum computers. This limits the way information can be transferred and rules out some direct approaches, like just creating a copy of the information at the new location. (That requires knowing the quantum state you are transferring.)

In the new protocol, data stored on one qubit is shared with its neighbors, using a phenomenon called quantum entanglement. Then, since all those qubits help carry the information, they work together to spread it to other sets of qubits. Because more qubits are involved, they transfer the information even more quickly.

This process can be repeated to keep generating larger blocks of qubits that pass the information faster and faster. So instead of the straightforward method of qubits passing information one by one like a basketball team passing the ball down the court, the qubits are more like snowflakes that combine into a larger and more rapidly rolling snowball at each step. And the bigger the snowball, the more flakes stick with each revolution.

But that's maybe where the similarities to snowballs end. Unlike a real snowball, the quantum collection can also unroll itself. The information is left on the distant qubit when the process runs in reverse, returning all the other qubits to their original states.

When the researchers analyzed the process, they found that the snowballing qubits speed along the information at the theoretical limits allowed by physics. Since the protocol reaches the previously proven limit, no future protocol should be able to surpass it.

part2

Comment by Dr. Krishna Kumari Challa on August 6, 2021 at 10:07am

New approach to information transfer reaches quantum speed limit

Researchers have  been investigating the theoretical constraints that will bound quantum technologies. One of the things researchers have discovered is that there are limits to how quickly quantum information can race across any quantum device.

These speed limits are called Lieb-Robinson bounds, and, for several years, some of the bounds have taunted researchers. For certain tasks, there was a gap between the best speeds allowed by theory and the speeds possible with the best algorithms anyone had designed. It's as though no car manufacturer could figure out how to make a model that reached the local highway limit.

But unlike speed limits on roadways, information speed limits can't be ignored when you're in a hurry—they are the inevitable results of the fundamental laws of physics. For any quantum task, there is a limit to how quickly interactions can make their influence felt (and thus transfer information) a certain distance away. The underlying rules define the best performance that is possible. In this way, information speed limits are more like the max score on an old school arcade game than traffic laws, and achieving the ultimate score is an alluring prize for scientists.

Now a team of researchers have found a quantum protocol that reaches the theoretical speed limits for certain quantum tasks. Their result provides new insight into designing optimal quantum algorithms and proves that there hasn't been a lower, undiscovered limit thwarting attempts to make better designs.

part1

Minh C. Tran et al, Optimal State Transfer and Entanglement Generation in Power-Law Interacting Systems, Physical Review X (2021). DOI: 10.1103/PhysRevX.11.031016

https://phys.org/news/2021-08-approach-quantum-limit.html?utm_sourc...

Comment by Dr. Krishna Kumari Challa on August 6, 2021 at 9:57am

Crop farmers face new disease pressures as climate changes
Climate change will increase the burden of crop diseases in some parts of the world and reduce it in others, new research suggests.
As the planet warms, the impact of crop diseases is likely to fall in tropical areas including Brazil, sub-Saharan Africa, India and Southeast Asia.

At higher latitudes (further from the equator), disease risk will grow—with Europe and China "particularly vulnerable".

The University of Exeter study, published in Nature Climate Change, says these changes will "closely track" variations in crop productivity expected under global warming.

Models suggest that rising temperatures will boost yields of most crops at high latitudes, while the tropics will see little or no gains.

The study also finds that the U.S., Europe and China are likely to see major changes in the mix of pathogens (diseases) affecting their crops.

"Rapid global dissemination by international trade and transport means pathogens are likely to reach all areas in which conditions are suitable for them."

Infection rates by plant pathogens are strongly determined by conditions including temperature.

Plant pathogen infection risk tracks global crop yields under climate change, Nature Climate Change (2021). DOI: 10.1038/s41558-021-01104-8 , www.nature.com/articles/s41558-021-01104-8

https://phys.org/news/2021-08-crop-farmers-disease-pressures-climat...

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