BLOGS

Observations of clouds, sunbeams, and birds—like those seen in this photo taken in Salisbury, UK—were important elements of classical weather forecasting. (Image courtesy of Peter Lawrence.)

Topics: History, Meteorology, Research

In August 1861 the London-based newspaper The Times published the world’s first “daily weather forecast.” The term itself was created by the enterprising meteorologist Robert FitzRoy, who wanted to distance his work from astrological “prognostications.” That story has led to a widespread assumption that weather forecasting is an entirely modern phenomenon and that in earlier periods only quackery or folklore-based weather signs were available.

However, more recent research has demonstrated that astronomers and astrologers in the medieval Islamic world drew widely on Greek, Indian, Persian, and Roman knowledge to create a new science termed astrometeorology. Central to the new science was the universal belief that the planets and their movements around Earth affected atmospheric conditions and weather. It was enthusiastically received in Christian Latin Europe and was further developed by Tycho Brahe, Johannes Kepler, and other astronomers. The drive to produce reliable weather forecasts led scientists to believe that astrometeorological forecasting could be more accurate if they used precise observations and records of weather to refine predictions for specific localities. Such records were kept across Europe beginning in the 13th century and were correlated with astronomical data, which paved the way for the data-driven forecasts produced by FitzRoy.¹

Islamicate astrometeorologists were the first to replace the ancient practice of observing only short-term signs, such as clouds and the flight of birds, to predict the weather. They based their action on the hypothesis that weather is caused by the movements of planets and mediated by regional and seasonal climate conditions. Improved calculations of planetary orbits and updated geographical and meteorological information made the new science possible and compelling.

The prospect of acquiring reliable weather forecasts, closely linked to predictions of coming trends in human health and agricultural production, made the new meteorology attractive in Christian Europe too. Considerable pride shines through medieval Christian accounts of the weather questions that they could now start to answer. Central among them was one that classical meteorologists had failed to figure out: How can weather vary so much from one year to the next when the seasons are caused by regular, repeating patterns produced by Earth’s spherical shape and its interactions with the Sun?

Medieval weather prediction, Anne Lawrence-Mathers is a professor of history at the University of Reading in the UK. Physics Today

Topics: Biology, Chemistry, DNA, Nobel Prize, Research, Women in Science

This year’s (2020) Nobel Prize in Chemistry has been awarded to two scientists who transformed an obscure bacterial immune mechanism, commonly called CRISPR, into a tool that can simply and cheaply edit the genomes of everything from wheat to mosquitoes to humans. 

The award went jointly to Emmanuelle Charpentier of the Max Planck Unit for the Science of Pathogens and Jennifer Doudna of the University of California, Berkeley, “for the development of a method for genome editing.” They first showed that CRISPR—which stands for clustered regularly interspaced short palindromic repeats—could edit DNA in an in vitro system in a paper published in the 28 June 2012 issue of Science. Their discovery was rapidly expanded on by many others and soon made CRISPR a common tool in labs around the world. The genome editor spawned industries working on making new medicines, agricultural products, and ways to control pests.

Many scientists anticipated that Feng Zhang of the Broad Institute, who showed 6 months later that CRISPR worked in mammalian cells, would share the prize. The institutions of the three scientists are locked in a fierce patent battle over who deserves the intellectual property rights to CRISPR’s discovery, which some estimate could be worth billions of dollars.

“The ability to cut DNA where you want has revolutionized the life sciences. The genetic scissors were discovered 8 years ago, but have already benefited humankind greatly,” Pernilla Wittung Stafshede, a chemical biologist at the Chalmers University of Technology, said at the prize briefing.

CRISPR was also used in one of the most controversial biomedical experiments of the past decade, when a Chinese scientist edited the genomes of human embryos, resulting in the birth of three babies with altered genes. He was widely condemned and eventually sentenced to jail in China, a country that has become a leader in other areas of CRISPR research.

Although scientists were not surprised Doudna and Charpentier won the prize, Charpentier was stunned. “As much as I have been awarded a number of prizes, it’s something you hear, but you don’t completely connect,” she said in a phone call with the Nobel Prize officials. “I was told a number of times that when it happens, you’re very surprised and feel that it’s not real.”

At a press briefing today, Doudna noted she was asleep and missed the initial calls from Sweden, only waking up to answer the phone finally when a Nature reporter called. "She wanted to know if I could comment on the Nobel and I said, Well, who won it? And she was shocked that she was the person to tell me."

CRISPR, the revolutionary genetic ‘scissors,’ honored by Chemistry Nobel, Jon Cohen, Science Magazine, AAAS

1 Soap, shampoo, and worm-like micelles Soaps and shampoos are made from amphiphilic molecules with water-loving (red) and water-hating (blue) parts that arrange themselves to form long tubes known as “worm-like micelles”. Entanglements between the tubes give these materials their pleasant, sticky feel. b The micelles can, however, disentangle themselves, just as entangled long-chain polymer molecules can slide apart too. In polymers, this process can be modeled by imagining the molecule sliding, like a snake, out of an imaginary tube formed by the surrounding spatial constraints. c Worm-like micelles can also morph their architecture by performing reconnections (left), breakages (down), and fusions (right). These operations occur randomly along the backbone, are in thermal equilibrium, and reversible. (Courtesy: Davide Michieletto)

Topics: Biology, DNA, Physics, Polymer Science, Research

DNA molecules are not fixed objects – they are constantly getting broken up and glued back together to adopt new shapes. Davide Michieletto explains how this process can be harnessed to create a new generation of “topologically active” materials.

Call me naïve, but until a few years ago I had never realized you can actually buy DNA. As a physicist, I’d been familiar with DNA as the “molecule of life” – something that carries genetic information and allows complex organisms, such as you and me, to be created. But I was surprised to find that biotech firms purify DNA from viruses and will ship concentrated solutions in the post. In fact, you can just go online and order DNA, which is exactly what I did. Only there was another surprise in store.

When the DNA solution arrived at my lab in Edinburgh, it came in a tube with about half a milligram of DNA per centimeter cube of water. Keen to experiment on it, I tried to pipette some of the solution out, but it didn’t run freely into my plastic tube. Instead, it was all gloopy and resisted the suction of my pipette. I rushed over to a colleague in my lab, eagerly announcing my amazing “discovery”. They just looked at me like I was an idiot. Of course, solutions of DNA are gloopy.

I should have known better. It’s easy to idealize DNA as some kind of magic material, but it’s essentially just a long-chain double-helical polymer consisting of four different types of monomers – the nucleotides A, T, C, and G, which stack together into base pairs. And like all polymers at high concentrations, the DNA chains can get entangled. In fact, they get so tied up that a single human cell can have up to 2 m of DNA crammed into an object just 10 μm in size. Scaled up, it’s like storing 20 km of hair-thin wire in a box no bigger than your mobile phone.

Make or break: building soft materials with DNA, Davide Michieletto is a Royal Society university research fellow in the School of Physics and Astronomy, University of Edinburgh

a, Manhattan plot of a genome-wide association study of 3,199 hospitalized patients with COVID-19 and 897,488 population controls. The dashed line indicates genome-wide significance (P = 5 × 10⁻⁸). Data were modified from the COVID-19 Host Genetics Initiative² (https://www.covid19hg.org/). b, Linkage disequilibrium between the index risk variant (rs35044562) and genetic variants in the 1000 Genomes Project. Red circles indicate genetic variants for which the alleles are correlated to the risk variant (r² > 0.1) and the risk alleles match the Vindija 33.19 Neanderthal genome. The core Neanderthal haplotype (r² > 0.98) is indicated by a black bar. Some individuals carry longer Neanderthal-like haplotypes. The location of the genes in the region is indicated below using standard gene symbols. The x-axis shows hg19 coordinates.

Topics: Biology, COVID-19, Genetics, Research

Abstract

A recent genetic association study¹ identified a gene cluster on chromosome 3 as a risk locus for respiratory failure after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A separate study (COVID-19 Host Genetics Initiative)² comprising 3,199 hospitalized patients with coronavirus disease 2019 (COVID-19) and control individuals showed that this cluster is the major genetic risk factor for severe symptoms after SARS-CoV-2 infection and hospitalization. Here we show that the risk is conferred by a genomic segment of around 50 kilobases in size that is inherited from Neanderthals and is carried by around 50% of people in South Asia and around 16% of people in Europe.

Main

The COVID-19 pandemic has caused considerable morbidity and mortality and has resulted in the death of over a million people to date³. The clinical manifestations of the disease caused by the virus, SARS-CoV-2, vary widely in severity, ranging from no or mild symptoms to rapid progression to respiratory failure⁴. Early in the pandemic, it became clear that advanced age is a major risk factor, as well as being male and some co-morbidities⁵. These risk factors, however, do not fully explain why some people have no or mild symptoms whereas others have severe symptoms. Thus, genetic risk factors may have a role in disease progression. A previous study¹ identified two genomic regions that are associated with severe COVID-19: one region on chromosome 3, which contains six genes, and one region on chromosome 9 that determines ABO blood groups. Recently, a dataset was released by the COVID-19 Host Genetics Initiative in which the region on chromosome 3 is the only region that is significantly associated with severe COVID-19 at the genome-wide level (Fig. 1a). The risk variant in this region confers an odds ratio for requiring hospitalization of 1.6 (95% confidence interval, 1.42–1.79) (Extended Data Fig. 1).

The genetic variants that are most associated with severe COVID-19 on chromosome 3 (45,859,651–45,909,024 (hg19)) are all in high linkage disequilibrium (LD)—that is, they are all strongly associated with each other in the population (r² > 0.98)—and span 49.4 thousand bases (kb) (Fig. 1b). This ‘core’ haplotype is furthermore in weaker linkage disequilibrium with longer haplotypes of up to 333.8 kb (r² > 0.32) (Extended Data Fig. 2). Some such long haplotypes have entered the human population by gene flow from Neanderthals or Denisovans, extinct hominins that contributed genetic variants to the ancestors of present-day humans around 40,000–60,000 years ago^6,7. We, therefore, investigated whether the haplotype may have come from Neanderthals or Denisovans.

The major genetic risk factor for severe COVID-19 is inherited from Neanderthals, Hugo Zeberg, & Svante Pääbo, Nature

Thin polymer discs self-propel by repeated "snapping" motions. Credit: Yongjin Kim, UMass Amherst

Topics: Chemistry, Polymer Science, Materials Science, Research

A polymer-based gel made by researchers in the US and inspired by the Venus flytrap plant can snap, jump and “reset” itself autonomously. The new self-propelled material might have applications in micron-sized robots and other devices that operate without batteries or motors.

“Many plants and animals, especially small ones, use special parts that act like springs and latches to help them move really fast, much faster than animals with muscles alone,” explains team leader Alfred Crosby, a professor of polymer science and engineering in the College of Natural Sciences at UMass Amherst. “The Venus flytraps are good examples of this kind of movement, as are grasshoppers and trap-jaw ants in the animal world.”

Snapping instabilities
The Venus flytrap plant works by regulating the way its turgor pressure – that is, the swelling produced as stored water pushes against a plant cell wall – is distributed through its leaves. Beyond a certain point, this swelling leads to a condition known as snapping instability, where the tiny additional pressure of a fly’s footsteps is enough to cause the plant to snap shut. The plant then automatically regenerates its internal structures in readiness for its next meal.

Polymer gels snap and jump on their own, Isabelle Dumé, Physics World

Topics: Chemistry, Einstein, Materials Science, Research

To date, researchers have created more than two dozen synthetic chemical elements that don’t exist naturally on Earth. Neptunium (atomic number Z = 93) and plutonium (Z = 94), the first two artificial elements after naturally occurring uranium, are produced in nuclear reactors by thousands of kilograms. But the accessibility of transuranic elements drops quickly with Z: Einsteinium (Z = 99) can be made only in microgram quantities in specialized laboratories, fermium (Z = 100) is produced by the picogram and has never been purified, and all elements after that are made just one atom at a time.

There are ways to probe the atomic properties of elements produced atom by atom (see, for example, Physics Today, June 2015, page 14). But when it comes to the traditional way of investigating how atoms behave—mixing them with other substances in solution to form chemical compounds—Es is effectively the end of the periodic table.

Now Rebecca Abergel (head of Lawrence Berkeley National Laboratory’s heavy element chemistry program) and her colleagues have performed the most complicated and informative Es chemistry experiment to date. They chose to react Es with a so-called octadentate ligand—a single organic molecule, held together by the backbone shown in blue, that wraps around a central metal atom and binds to it from all sides—to create the molecular structure shown in the figure. In their previous work, Abergel and colleagues used the same ligand to study transition metals, lanthanides, and lighter actinides. When they were fortunate enough to acquire a few hundred nanograms of Es from Oak Ridge National Laboratory, they used it on that as well.

Einsteinium chemistry captured, Johanna L. Miller, Physics Today

Anthony Fauci has advised seven presidents on public health, most recently serving as chief medical advisor to President Joe Biden. | NIAID

Topics: Biology, COVID-19, Research, Science

Anthony Fauci – Director of the National Institute of Allergy and Infectious Diseases, an expert on HIV and immunoregulation, and the de facto public face of a science-based recovery from COVID-19 – has been named the winner of the 2021 Philip Hauge Abelson Prize, awarded annually by the American Association for the Advancement of Science to a scientist or public servant who has contributed significantly to the advancement of science in the United States.

Fauci is “an outstanding scientist with more than a thousand publications” and “an exceptional public servant, having been at the forefront of the world’s efforts to combat diverse infectious diseases for over 40 years,” wrote Alan Leshner, former chief executive officer of AAAS, in nominating Fauci for the prize. The prize committee cited Fauci’s “extraordinary contributions to science and medicine” and his service that has shaped research and public policy.

Anthony Fauci to Receive 2021 AAAS Abelson Prize, Andrea Korte, American Association for the Advancement of Science

Image source: The article link, but it should symbolize how last year felt to the sane among us.

Topics: Biology, Materials Science, Nanotechnology, Research

Snake vision inspires pyroelectric material design

Bioinspiration and biomimicry involve studying how living organisms do something and using that insight to develop new technologies. Pit vipers have two special organs on their heads called loreal pits that allow them to “see” the infrared radiation given off by their warm-blooded prey. Now, Pradeep Sharma and colleagues have worked out that the snakes use cells that act as a soft pyroelectric material to convert infrared radiation into electrical signals that can be processed by their nervous systems. As well as potentially solving a longstanding puzzle in snake biology, the work could also aid the development of thermoelectric transducers based on soft, flexible structures rather than stiff crystals.

Nanotechnology and materials highlights of 2020, Hamish Johnston, Physics World

Topics: Biology, COVID-19, Research

With COVID-19 reaching the most dangerous levels the U.S. has seen since the pandemic began, the country faces a problematic holiday season. Despite the risk, many people are likely to travel using various forms of transportation that will inevitably put them in relatively close contact with others. Many transit companies have established frequent cleaning routines, but evidence suggests that airborne transmission of the novel coronavirus poses a greater danger than surfaces. The virus is thought to be spread primarily by small droplets, called aerosols, that hang in the air and larger droplets that fall to the ground within six feet or so. Although no mode of public transportation is completely safe, there are some concrete ways to reduce risk, whether on an airplane, train or bus—or even in a shared car.

At a casual glance, air travel might seem like the perfect recipe for COVID transmission: it packs dozens of people into a confined space, often for hours at a time. But many planes have excellent high-efficiency particulate air (HEPA) filters that capture more than 99 percent of particles in the air, including microbes as SARS-CoV-2, the coronavirus that causes COVID. When their recirculation systems are operating, most commercial passenger jets bring in outside air in a top-to-bottom direction about 20 to 30 times per hour. This results in a 50–50 mix of outside and recirculated air and reduces the potential for the airborne spread of a respiratory virus. Many airlines now require passengers to wear a mask during flights except for mealtimes, and some are blocking off middle seats to allow more distancing between people. Companies have also implemented rigorous cleaning procedures between flights. So how does this translate into overall risk?

“An airplane cabin is probably one of the most secure conditions you can be in,” says Sebastian Hoehl of the Institute for Medical Virology at Goethe University Frankfurt in Germany, who has co-authored two papers on COVID-19 transmission on specific flights, which were published in JAMA Network Open and the New England Journal of Medicine, respectfully. Still, a handful of case studies have found that limited transmission can take place on board. One such investigation of a 10-hour journey from London to Hanoi starting on March 1 found that 15 people were likely infected with COVID-19 in-flight—and that 12 of them had sat within a couple of rows of a single symptomatic passenger in business class. (The results were published this month in the U.S. Centers for Disease Control and Prevention’s journal Emerging Infectious Diseases.) Most of these flights occurred early on in the pandemic, however, and in the case of the March 1 flight, masks were likely not worn, the researchers wrote. Meanwhile, a recent Department of Defense study modeled the risk of in-flight infection using mannequins exhaling simulated virus particles and found that a person would have to be exposed to an infectious passenger for at least 54 hours to get an infectious dose. This finding assumes the infected passenger is wearing a surgical mask, however, and it does not account for the dangers involved in removing the mask for meals or talking or in moving about on the plane.

Evaluating COVID Risk on Planes, Trains, and Automobiles, Sophie Bushwick, Tanya Lewis, Amanda Montañez, Scientific American

Students and instructors wave bye to each other after the close of a virtual session of All About Energy. (Image by Argonne National Laboratory.)

Topics: Education, Energy, Research, STEM

Argonne Educational Programs and Outreach transitioned to virtual summer programming, ensuring that Argonne continues to build the next generation of STEM leaders.

At the U.S. Department of Energy’s (DOE) Argonne National Laboratory, scientists and educators have found new ways to balance their work with safety needs as the laboratory’s Educational Programs and Outreach Department successfully transitioned all of its summer programming to a virtual learning environment.

By connecting scientific and research divisions across the laboratory, Argonne was able to create multiple virtual programs, helping young people stay connected and engage with the laboratory’s science, technology, engineering and math (STEM) education opportunities.

“Providing STEM opportunities and a constant presence with our next generation of STEM professions during a time that is unsettling and turbulent for everyone, but especially our school age and university student populations, was our top priority.” — Meridith Bruozas, Educational Programs, and Outreach manager

“Argonne continues to adapt and lead impactful science during the ongoing pandemic, a strategy that includes strengthening the STEM pipeline with unique educational programs for future scientists and engineers,” said Argonne Director Paul Kearns. ​“For years, hundreds of students have pursued summer learning opportunities at Argonne that are not available anywhere else. I’m pleased that in 2020 our lab community came together to maintain these high-quality STEM experiences through a successful virtual program for next-generation researchers.”

Argonne provides STEM opportunities for more than 800 students during pandemic, Nathan Schmidt, Argonne National Laboratory

The black phosphorus composite material connected by carbon-phosphorus covalent bonds has a more stable structure and a higher lithium-ion storage capacity. Credit: DONG Yihan, SHI Qianhui, and LIANG Yan

Topics: Alternative Energy, Applied Physics, Battery, Nanotechnology, Research

A new electrode material could make it possible to construct lithium-ion batteries with a high charging rate and storage capacity. If scaled up, the anode material developed by researchers at the University of Science and Technology of China (USTC) and colleagues in the US might be used to manufacture batteries with an energy density of more than 350 watt-hours per kilogram – enough for a typical electric vehicle (EV) to travel 600 miles on a single charge.

Lithium ions are the workhorse in many common battery applications, including electric vehicles. During operation, these ions move back and forth between the anode and cathode through an electrolyte as part of the battery’s charge-discharge cycle. A battery’s performance thus depends largely on the materials used in the electrodes and electrolyte, which need to be able to store and transfer many lithium ions in a short period – all while remaining electrochemically stable – so they can be recharged hundreds of times. Maximizing the performance of all these materials at the same time is a longstanding goal of battery research, yet in practice, improvements in one usually come at the expense of the others.

“A typical trade-off lies in the storage capacity and rate capability of the electrode material,” co-team leader Hengxing Ji tells Physics World. “For example, anode materials with high lithium storage capacity, such as silicon, are usually reported as having low lithium-ion conductivity, which hinders fast battery [charging]. As a result, the increase in battery capacity usually leads to a long charging time, which represents a critical roadblock for more widespread adoption of EVs.”

Black phosphorus composite makes a better battery, Isabelle Dumé, Physics World

Image Source: Link below

Topics: Biology, COVID-19, Research

Continued: It triggered a big outbreak. At least 97 people who attended the conference, or lived in a household with someone who did, tested positive.

The Biogen meeting had become a superspreading event. Eventually, the virus spread from the meeting across Massachusetts and to other states. A recent study estimates it led to tens of thousands of cases in the Boston area alone.

Superspreading

COVID-19 superspreading events have been reported around the world. They happen in all sorts of places: bars and barbecues, gyms and factories, schools and churches, and on ships.

And even at the White House.

But why do these disease clusters occur—and why are they so important?

The reproduction rate

COVID-19 and many other diseases transmit from person to person. The reproduction rate, R, determines how fast a disease can spread.

R denotes the number of people infected, on average, by a single infected person. If R is 2, the number of cases doubles in every generation: from one infected person to two, to four, to eight, and so on.

The Science of Superspreading, Martin Enserink, Kai Kupferschmidt, and Nirja Desai, Science Magazine

Image Source: Link below

Topics: Autonomous Vehicles, Mechanical Engineering, Research, Robotics

Abstract

Legged locomotion can extend the operational domain of robots to some of the most challenging environments on Earth. However, conventional controllers for legged locomotion are based on elaborate state machines that explicitly trigger the execution of motion primitives and reflexes. These designs have increased in complexity but fallen short of the generality and robustness of animal locomotion. Here, we present a robust controller for blind quadrupedal locomotion in challenging natural environments. Our approach incorporates proprioceptive feedback in locomotion control and demonstrates zero-shot generalization from simulation to natural environments. The controller is trained by reinforcement learning in simulation. The controller is driven by a neural network policy that acts on a stream of proprioceptive signals. The controller retains its robustness under conditions that were never encountered during training: deformable terrains such as mud and snow, dynamic footholds such as rubble, and overground impediments such as thick vegetation and gushing water. The presented work indicates that robust locomotion in natural environments can be achieved by training in simple domains.

Learning quadrupedal locomotion over challenging terrain, Joonho Lee¹, Jemin Hwangbo ^1,2, Lorenz Wellhausen¹, Vladlen Koltun^3, and Marco Hutter¹

Science Robotics  21 Oct 2020:
Vol. 5, Issue 47, eabc5986
DOI: 10.1126/scirobotics.abc5986

Topics: Microscopy, Nanotechnology, NEMS, Physics, Research

ABSTRACT

Single-molecule microscopy has become an indispensable tool for biochemical analysis. The capability of characterizing distinct properties of individual molecules without averaging has provided us with a different perspective for the existing scientific issues and phenomena. Recently, super-resolution fluorescence microscopy techniques have overcome the optical diffraction limit by the localization of molecule positions. However, the labeling process can potentially modify the intermolecular dynamics. Based on the highly sensitive nanomechanical photothermal microscopy reported previously, we propose optimizations on this label-free microscopy technique toward localization microscopy. A localization precision of 3 Å is achieved with gold nanoparticles, and the detection of polarization-dependent absorption is demonstrated, which opens the door for further improvement with polarization modulation imaging.

FIG. 2. (a) Schematic of the measurement setup. BE: beam expander. M: mirror. WP: waveplate. LP: linear polarizer. BS: beam splitter. PD: photodetector/power meter. DM: dichroic mirror. ID: iris diaphragm. CCD: charge-coupled device camera. APD: avalanche photodiode detector. (b) The transduction scheme of the trampoline resonator. (c) SEM image of the trampoline resonator.

J. Appl. Phys. 128, 134501 (2020); https://doi.org/10.1063/5.0014905

Nanoelectromechanical photothermal polarization microscopy with 3 Å localization precision, Miao-Hsuan Chien and Silvan Schmid, Journal of Applied Physics

Image Source: Coronavirus and COVID-19: What You Should Know (WebMD)

Topics: Biology, Computer Modeling, COVID-19, Research

TOKYO (Reuters) – A Japanese supercomputer showed that humidity can have a large effect on the dispersion of virus particles, pointing to heightened coronavirus contagion risks in dry, indoor conditions during the winter months.

The finding suggests that the use of humidifiers may help limit infections during times when window ventilation is not possible, according to a study released on Tuesday by research giant Riken and Kobe University.

The researchers used the Fugaku supercomputer to model the emission and flow of virus-like particles from infected people in a variety of indoor environments.

Air humidity of lower than 30% resulted in more than double the amount of aerosolized particles compared to levels of 60% or higher, the simulations showed.

The study also indicated that clear face shields are not as effective as masks in preventing the spread of aerosols. Other findings showed that diners are more at risk from people to their side compared to across the table, and the number of singers in choruses should be limited and spaced out.

Japan supercomputer shows humidity affects aerosol spread of coronavirus, Rocky Swift, Reuters Science

Gentle breeze: illustration of the B-TENG triboelectric nanogenerator, which harvests electricity that is generated by fluttering polymer strips. (Courtesy: Xin Chen/Xiaojing Mu/Ya Yang)

Topics: Applied Physics, Nanotechnology, Polymers, Research

A new low-cost nanogenerator that can efficiently harvest electrical energy from ambient wind has been created by Ya Yang at the Beijing Institute of Nanoenergy and Nanosystems of the Chinese Academy of Sciences and colleagues. The team reports that the device achieves high electrical conversion efficiencies for breezes of 4–8 m/s (14–28 km/h) and says that it could be used to generate electricity in everyday situations, where conventional wind turbines are not practical.

As the drive to develop renewable sources of energy intensifies, there is growing interest in harvesting ambient energy in everyday environments. From breezes along city streets to the airflows created as we walk, the mechanical energy contained in ambient wind is abundant. The challenge is to harvest this every in an efficient and practical way. This has proven difficult using existing technologies such as piezoelectric films, which operate at very low power outputs.

Yang’s team based their new design around two well-known phenomena in physics. The first is the Bernoulli effect, which causes the fluttering of two adjacent flags to couple. If separated by a very small gap, the flags will flutter in-phase, while at slightly larger separations, they flap out-of-phase, and symmetrically about a central plane. The second is the triboelectric effect – the familiar phenomenon behind the “static electricity” that is created when different objects are rubbed together and then separated – resulting in opposite electrical charges on the objects and a voltage between the two.

Fluttering polymer ribbons harvest electrical energy, Physics World

Topics: COVID-19, Existentialism, Research

I assure you, I have been affected by this pandemic more than most. I am in a demographic that can experience deleterious effects from this virus. I have had friends and family affected directly. I have classmates that are struggling to survive. This is no hoax: it's real.

My precautions are beyond anal.

I worked in cleanrooms in the semiconductor industry, the most stringent being Class 1. The old criteria meant 0.5 microns of particles per cubic feet of air. (The newest guidelines were adopted in 2001, metric and still pretty stringent.) Each employee passed through air showers to push off any particulates from their clothing. Smokers are encouraged not to indulge, and cologne was prohibited - smoke and scent are particles. We then put our street garb in a locker, putting on green hospital gowns and fab shoes that never left the site. Then we donned cleanroom gowns - "bunny suits" - before going into the alien, HEPA-filtered environment, protecting it from any hair, skin, sweat, or dirt we could shed that would inhibit the functionality of integrated circuits. I tried to drink as little water as possible before going on the floor. Going to the bathroom, or lunch was a pain.

I have developed a unique protocol for assaulting what used to be trivial things like getting the mail, mowing the lawn - grass grows as rains fall during pandemics - or, going to the grocers for supplies.

1. I fashioned a mask from my father's handkerchiefs and rubber bands per the CDC guidelines. (I now have a collection of 5).

2. I use cloth/rubber work gloves for mowing as the rubber is tactile enough for me to operate equipment and pay for items at the grocery store.

3. After I enter the house, I immediately put all clothing - including my gloves - in the washer. I proceed to the shower.

Source: https://physics4thecool.blogspot.com/2020/04/protocols.html

The confluence of misinformation and infectious disease isn’t unique to COVID-19. Misinformation contributed to the spread of the Ebola epidemic in West Africa, and it plagues efforts to educate the public on the importance of vaccinating against measles. But when it comes to COVID-19, the pandemic has come to be defined by a tsunami of persistent misinformation to the public on everything from the utility of masks and the efficacy of school closures, to the wisdom behind social distancing, and even the promise of untested remedies. According to a study published by the National Bureau of Economic Research, areas of the country exposed to television programming that downplayed the severity of the pandemic saw greater numbers of cases and deaths—because people didn’t follow public health precautions.

In the United States, misinformation spread by elements of the media, by public leaders, and by individuals with large social media platforms has contributed to a disproportionately large share of COVID-19 burden: we house 4 percent of the global population but account for 22 percent of global COVID-19 deaths. With winter around the corner and people spending more time indoors, it is more imperative than ever that we counter misinformation and clearly communicate risks to the public; in addition, as we await the arrival of a vaccine, it is equally important to arm the public with facts. We have work to do: a recent poll found that just half of the American public plans to get a COVID-19 vaccine.

COVID Misinformation Is Killing People - This “infodemic” has to stop

Amir Bagherpour, Ali Nouri, Scientific American

Reflective markers are attached to blue 3D-printed apparatus above and below the user’s knee as well as two metal plates on the exoskeleton leg. Researchers track and compare the movement of the markers to gain insight into how well the exoskeletons fit. In this composite photo, the bottom plate has been added after the original image was taken to show the entire configuration.
Credit: N. Hanacek/NIST

Topics: Applied Physics, NIST, Research, Robotics

A shoddily tailored suit or a shrunken T-shirt may not be the most stylish, but wearing them is unlikely to hurt more than your reputation. An ill-fitting robotic exoskeleton on the battlefield or factory floor, however, could be a much bigger problem than a fashion faux pas. 

Exoskeletons, many of which are powered by springs or motors, can cause pain or injury if their joints are not aligned with the user. To help manufacturers and consumers mitigate these risks, researchers at the National Institute of Standards and Technology (NIST) developed a new measurement method to test whether an exoskeleton and the person wearing it are moving smoothly and in harmony. 

In a new report, the researchers describe an optical tracking system (OTS) not unlike the motion capture techniques used by filmmakers to bring computer-generated characters to life. 

The OTS uses special cameras that emit light and capture what is reflected back by spherical markers arranged on objects of interest. A computer calculates the position of the labeled objects in 3D space. Here, this approach was used to track the movement of an exoskeleton and test pieces, called “artifacts,” fastened to its user.

Exoskeleton Research Marches Forward With NIST Study on Fit, NIST

The spike protein of the SARS-CoV-2 virus (gray) is shown with three small antibodies (pink) attached to its receptor binding domains. The spike attaches at the left to the viral membrane (not shown). DIAMOND LIGHT SOURCE

Topics: Chemistry, COVID-19, Physics, Research

As the world anxiously awaits development of one or more vaccines to tame the SARS-CoV-2 virus, other research continues at a feverish pace to find effective treatments for the disease it causes, COVID-19. That work, in which physicists and chemists are deeply involved, has made significant strides in the past several months and has turned up a few surprises. Researchers at the University of Alberta reported at the August virtual meeting of the American Crystallographic Association that a dipeptide-based protease inhibitor used to treat a fatal coronavirus infection in cats also blocks replication of the SARS-CoV-2 virus in samples of monkey lung tissue. Joanne Lemieux, a biochemist at the university, says the antiviral, known as GC373, works by blocking the function of the main protease (M^pro), an enzyme that cleaves the polyproteins translated from viral RNA into individual proteins once it enters human cells.

Lemieux says GC373 has been shown to have no toxic effects in cats. Anivive, a California company that develops pet medicines, has applied for US Food and Drug Administration approval to begin trials in humans. Lemieux’s group crystallized the M^pro in combination with the drug and produced three-dimensional images of how the drug binds strongly to the active pocket on the enzyme. Although GC373 should be effective in its current form, the group is planning further crystallography experiments at the Stanford Synchrotron Radiation Lightsource (SSRL) and the Canadian Light Source to see if a reformulation could optimize it for human use, she says.

Cats and llamas could offer a path to coronavirus therapies, David Kramer, Physics Today