Comment

Comment by Dr. Krishna Kumari Challa on November 27, 2021 at 12:05pm

Warm weather or bright lights can influence tree greening

How both global warming and bright city lights can impact phenology in trees (when they begin to grow leaves in the spring?

 In her paper published in the journal Science, Meng, the Science & SciLifeLab Prize  for young scientist's award winner, outlines her study of satellite data showing green areas in cities along with artificial light sources and also trees growing in the Alps.

Prior research has shown that higher temperatures in cities can impact vegetation growth. In this new effort, Meng wondered what city warming, combined with global warming might be doing to the times that trees "green up" in the spring each year. To find out, she obtained and analyzed satellite data that showed when trees begin producing leaves in the spring each year for 85 U.S. cities over the years 2001 to 2014.

She found that tree green-up happens on average 6 days earlier in urban areas compared to rural areas. She also found that trees in the city are responding to climate change faster than trees in rural areas.

Meng also wondered about the impact of bright lights on trees and whether they might make trees start growing their leaves earlier in the spring each year. She studied trees growing in the Alps in Europe—noting that it is a place with a rather uniform temperature distribution but also has changing lengths of daylight across latitudes. She found evidence of a reduction in an early green-up likely due to global warming. She then studied data from NASA's Black Marble satellite, which measures artificial light in cities and also phenology data from the USA National Phenology Network. This allowed her to compare conditions in cities both with and without artificial light in the U.S., and she found that artificial light pushed spring green-up by nine days in the most extreme cases.

Meng concludes by suggesting that artificial light, by supplementing day length, leads to additions of earlier spring greening in cities, adding to the impact of earlier greening due to global warming. 

Lin Meng, Green with phenology, Science (2021). DOI: 10.1126/science.abm8136

https://phys.org/news/2021-11-weather-bright-tree-greening.html?utm...

**

Comment by Dr. Krishna Kumari Challa on November 27, 2021 at 11:58am

The experiment by the team involved creating a beam of deuterium and helium molecules in a chamber cooled to –272°C. They then used pairs of polarized laser bursts to push deuterium molecules into a certain vibrational and rotational state with different orientations—at right angles to one another. These served as the slits for the experiment. The team also forced other deuterium molecules into a state where they were suppositions of both of the orientations of the slits. As helium atoms scattered off the superposed molecules (along different paths that interfered with one another), the deuterium could in a sense "feel" them both at the same time. And as the helium atoms collided with the molecules, the deuterium atoms were released back to their original state at which point, they were ionized and studied by the research team.

The researchers suggest that in addition to conducting the double-slit experiment in a new way, their work also lays the groundwork for studying quantum behavior in a new way—by preparing new types of matter. They conclude by suggesting that their techniques could also be adapted for use in studying decoherence.

Haowen Zhou et al, Quantum mechanical double slit for molecular scattering, Science (2021). DOI: 10.1126/science.abl4143

https://phys.org/news/2021-11-molecules-atoms-double-slit.html?utm_...

Part 2

**

Comment by Dr. Krishna Kumari Challa on November 27, 2021 at 11:57am

Using molecules and atoms to conduct the double-slit experiment

A team of researchers  has developed a way to conduct the famous double-slit experiment at the molecular level. In their paper published in the journal Science, the group describes their technique and suggest that it could be used to assist with other molecular experiments.

In 1801, Thomas Young conducted what has come to be known as the double-slit experiment. At the time, he used it as a means to prove that light behaves as a wave. Since that time, light has been found to also behave as a particle of course, and the double-slit experiment has since been conducted in various ways under various conditions. Others have shown that electrons and atoms and molecules exhibit the same type of behavior. In this new effort, the researchers have taken the experiment to a new level by using nothing but molecules, single atoms and lasers. In the original double-slit experiment, the light passed through both slits in a superposition of trajectories. In this new method, there is only one slit, but it is in a superposition of positions.

Part 1

Comment by Dr. Krishna Kumari Challa on November 27, 2021 at 11:17am

COVID-19 : Measuring viral RNA to predict which patients will die

The amount of a SARS-CoV-2 genetic material—viral RNA—in the blood is a reliable indicator in detecting which patients will die of the disease, a team  of researchers has found.

In this study, scientists were able to determine which biomarkers are predictors of mortality in the 60 days following the onset of symptoms. They have successfully developed and validated a statistical model based on one blood biomarker, viral RNA.  Several biomarkers have been identified in other studies, but juggling the profusion of parameters is not possible in a clinical setting and hinders doctors' ability to make quick medical decisions.

Using blood samples collected from 279 patients during their hospitalization for COVID-19, ranging in degrees of severity from moderate to critical, the  team measured amounts of inflammatory proteins, looking for any that stood out.

At the same time, they measured the amounts of viral RNA and  the levels of antibodies targeting the virus. Samples were collected 11 days after the onset of symptoms and patients were monitored for a minimum of 60 days after that.

The goal: to test the hypothesis that immunological indicators were associated with increased mortality. Among all of the biomarkers they evaluated, they showed that the amount of viral RNA in the blood was directly associated with mortality and provided the best predictive response, once their model was adjusted for the age and sex of the patient. They even found that including additional biomarkers did not improve predictive quality.

It made no difference which hospital the patients were treated at, nor which period of the pandemic they fell into: in all cases, the predictive model worked. Now the researchers  want to put it to practical use.

Elsa Brunet-Ratnasingham et al, Integrated immunovirological profiling validates plasma SARS-CoV-2 RNA as an early predictor of COVID-19 mortality, Science Advances (2021). DOI: 10.1126/sciadv.abj5629. www.science.org/doi/10.1126/sciadv.abj5629

https://medicalxpress.com/news/2021-11-covid-viral-rna-patients-die...

Comment by Dr. Krishna Kumari Challa on November 27, 2021 at 9:58am

quantified the entropy produced by a system evolving in quantum superposition of processes with opposite time arrows. We found this most often results in projecting the system onto a well-defined time's direction, corresponding to the most likely process of the two. And yet, when small amounts of entropy are involved (for instance, when there is so little toothpaste spilled that one could see it being reabsorbed into the tube), then one can physically observe the consequences of the system having evolved along the forward and backward temporal directions at the same time.

Aside from the fundamental feature that time itself might not be well-defined, the work also has practical implications in quantum thermodynamics. Placing a quantum system in a superposition of alternative time's arrows could offer advantages in the performance of thermal machines and refrigerators.

Although time is often treated as a continuously increasing parameter, this study shows the laws governing its flow in quantum mechanical contexts are much more complex. This may suggest that we need to rethink the way we represent this quantity in all those contexts where quantum laws play a crucial role.

Quantum superposition of thermodynamic evolutions with opposing time's arrows, Communications Physics (2021). DOI: 10.1038/s42005-021-00759-1

https://phys.org/news/2021-11-quantum-realm.html?utm_source=nwlette...

Part 2

**

Comment by Dr. Krishna Kumari Challa on November 27, 2021 at 9:03am

In the quantum realm, not even time flows as you might expect

A team of physicists has shown how quantum systems can simultaneously evolve along two opposite time arrows—both forward and backward in time.

The study, published in the latest issue of Communications Physics, necessitates a rethink of how the flow of time is understood and represented in contexts where quantum laws play a crucial role.

For centuries, philosophers and physicists have been pondering the existence of time. Yet, in the classical world, our experience seems to extinguish any doubt that time exists and goes on. Indeed, in nature, processes tend to evolve spontaneously from states with less disorder to states with more disorder, and this propensity can be used to identify an arrow of time. In physics, this is described in terms of 'entropy', which is the physical quantity defining the amount of disorder in a system.

If a phenomenon produces a large amount of entropy, observing its time-reversal is so improbable as to become essentially impossible. However, when the entropy produced is small enough, there is a non-negligible probability of seeing the time-reversal of a phenomenon occur naturally.

An example. If we were shown our toothpaste moving from the toothbrush back into its tube, we would be in no doubt it was a rewinded recording of our day. However, if we squeezed the tube gently so only a small part of the toothpaste came out, it would not be so unlikely to observe it re-entering the tube, sucked in by the tube's decompression.

The authors of this study applied this idea to the quantum realm, one of whose peculiarities is the principle of quantum superposition, according to which if two states of a quantum system are both possible, then that system can also be in both states at the same time.

Extending this principle to time's arrows, it results that quantum systems evolving in one or the other temporal direction (the toothpaste coming out of or going back into the tube), can also find themselves evolving simultaneously along both temporal directions.

"Although this idea seems rather nonsensical when applied to our day-to-day experience, at its most fundamental level, the laws of the universe are based on quantum-mechanical principles. This begs the question of why we never encounter these superpositions of time flows in nature.

Part 1

Comment by Dr. Krishna Kumari Challa on November 27, 2021 at 8:35am

Physicists detect signs of neutrinos at Large Hadron Collider

The international Forward Search Experiment team has achieved the first-ever detection of neutrino candidates produced by the Large Hadron Collider at the CERN facility near Geneva, Switzerland.

In a paper published recently in the journal Physical Review D, the researchers describe how they observed six neutrino interactions during a pilot run of a compact emulsion detector installed at the LHC in 2018. This significant breakthrough is a step toward developing a deeper understanding of these elusive particles and the role they play in the universe.

 Henso Abreu et al, First neutrino interaction candidates at the LHC, Physical Review D (2021). DOI: 10.1103/PhysRevD.104.L091101

https://phys.org/news/2021-11-physicists-neutrinos-large-hadron-col...

Comment by Dr. Krishna Kumari Challa on November 26, 2021 at 11:22am

Microorganisms in our environment, such as soil dwelling bacteria, have evolved nonribosomal peptide synthetase enzymes (NRPS) that assemble building blocks called amino acids into peptide products which often have very potent antibiotic activity. Many of the most therapeutically important antibiotics, used in the clinic today, are derived from these NRPS enzymes (e.g. penicillin, vancomycin and daptomycin).

Unfortunately, deadly pathogens are emerging which are resistant to all of these existing antibiotic drugs. One solution could be to create new antibiotics with improved properties that can evade the resistance mechanisms of the pathogens. However, the nonribosomal peptide antibiotics are very complex structures which are difficult and expensive to produce by normal chemical methods. To address this, the research  team use gene editing to engineer the NRPS enzymes, swapping domains that recognize different amino acid building blocks, leading to new assembly lines that can deliver new peptide products.

Researchers are now able to use gene editing to introduce targeted changes to complex NRPS enzymes, enabling alternative amino acids precursors to be incorporated into the peptide structures. They are optimistic that this new approach could lead to new ways of making improved antibiotics which are urgently needed to combat emerging drug-resistant pathogens.

Wei Li Thong et al, Gene editing enables rapid engineering of complex antibiotic assembly lines, Nature Communications (2021). DOI: 10.1038/s41467-021-27139-1

https://phys.org/news/2021-11-scientists-antibiotics-gene.html?utm_...

**

Comment by Dr. Krishna Kumari Challa on November 26, 2021 at 11:21am

Scientists produce new antibiotics by gene editing

Scientists have discovered a new route to produce complex antibiotics exploiting gene editing to re-program pathways to future medicines urgently required to combat antimicrobial resistance, treat neglected diseases and tackle future pandemics.

Researchers from The University of Manchester have discovered a new way of manipulating key assembly line enzymes in bacteria which could pave the way for a new generation of antibiotic treatments.

New research published today in Nature Communications, describes how CRISPR-Cas9 gene editing can be used to create new nonribosomal peptide synthetase (NRPS) enzymes that deliver clinically important antibiotics. NRPS enzymes are prolific producers of natural antibiotics such as penicillin. However, up until now, manipulating these complex enzymes to produce new and more effective antibiotics has been a major challenge.

 the gene editing process could be used to produce improved antibiotics and possibly lead to the development of new treatments helping in the fight against drug-resistant pathogens and illnesses in the future. 

The emergence of antibiotic-resistant pathogens is one of the biggest threats we face today.

The gene editing approach the researchers  developed now is a very efficient and rapid way to engineer complex assembly line enzymes that can produce new antibiotic structures with potentially improved properties.

Part 1

Comment by Dr. Krishna Kumari Challa on November 26, 2021 at 11:10am

As for COVID-19 vaccines, the primary antigen used is the SARS-CoV-2 spike protein. According to Murphy and Longo, current research studies on antibody responses to these vaccines mainly focus on the initial protective responses and virus-neutralizing efficacy, rather than other long-term aspects.

"With the incredible impact of the pandemic and our reliance on vaccines as our primary weapon, there is an immense need for more basic science research to understand the complex immunological pathways at play. This need follows to what it takes to keep the protective responses going, as well as to the potential unwanted side effects of both the infection and the different SARS-CoV-2 vaccine types, especially as boosting is now applied. "The good news is that these are testable questions that can be partially addressed in the laboratory, and in fact, have been used with other viral models."

 William J. Murphy et al, A Possible Role for Anti-idiotype Antibodies in SARS-CoV-2 Infection and Vaccination, New England Journal of Medicine (2021). DOI: 10.1056/NEJMcibr2113694

https://medicalxpress.com/news/2021-11-antibodies-mimicking-virus-h...

Part 3

**

• ‹ Previous
• 1
• …
• 697
• 698
• 699
• 700
• 701
• …
• 1231
• Next ›
• Page