It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
IMAGE: PURPLE SULFUR BACTERIA IN FRESHWATER LAKE CADAGNO (UPPER PANELS, IN GREEN AND PURPLE), AND THEIR SINGLE-CELL NITROGEN FIXATION ACTIVITY MEASURED WITH NANOSIMS (LOWER PANELS, WARM COLORS INDICATE HIGH ACTIVITY).view more
CREDIT: MAX PLANCK INSTITUTE FOR MARINE MICROBIOLOGY/M. PHILIPPI
Nitrogen is vital for all forms of life¬: It is part of proteins, nucleic acids and other cell structures. Thus, it was of great importance for the development of life on early Earth to be able to convert gaseous dinitrogen from the atmosphere into a bio-available form – ammonium. However, it has not yet been clarified who carried out this so-called nitrogen fixation on early Earth and with the help of which enzyme. Now, researchers at the Max Planck Institute for Marine Microbiology in Bremen have shown that under similarly barren conditions as in the Proterozoic ocean, a previously underappreciated group of bacteria can fix nitrogen very efficiently.
A “small Proterozoic ocean” in the Swiss Alps
Since the Proterozoic ocean can hardly be studied directly, the researchers Miriam Philippi and Katharina Kitzinger from the Max Planck Institute in Bremen and colleagues substituted it with a comparable modern-day habitat: The alpine Lake Cadagno in Switzerland. Unlike most other lakes, Lake Cadagno is permanently stratified, meaning that the upper and lower water layers do not mix. Purple sulfur bacteria inhabit the transition zone between the upper, oxygenated layer and the lower, oxygen-free and sulfidic layer. There, they carry out photosynthesis and oxidize sulfur. “The discovery of fossils of this group of microorganisms shows that they already lived on our planet at least 1.6 billion years ago, during the Proterozoic eon,” said Philippi, first author of the study. “Hence, this lake and these bacteria represent a system that resembles the Proterozoic ocean in many aspects.” Therefore, it is so well-suited for learning more about the processes on early Earth.
Purple sulfur bacteria fix nitrogen
Using a combination of biogeochemical and molecular analyses, Philippi and colleagues discovered that the purple sulfur bacteria in Lake Cadagno fix nitrogen very efficiently. Nitrogen fixation is the conversion of nitrogen gas, which is not very reactive, into nitrogen compounds that many organisms can use, for example algae. “To our knowledge, this is the first direct evidence of nitrogen fixation by purple sulfur bacteria in nature,” explained co-author Katharina Kitzinger. “We discovered that they use the most common enzyme in present-day, molybdenum nitrogenase, to do so. Although this enzyme is not rare, we were very surprised to find it in Lake Cadagno.” This is because there is only very little molybdenum in the water – just as in the Proterozoic ocean, which has led researchers to believe that non-molybdenum nitrogenases prevailed on early Earth. “Now we know that molybdenum nitrogenase works very efficiently, even at low molybdenum concentrations.”
“We thus provide the first indication that purple sulfur bacteria may have been partly responsible for nitrogen fixation in the Proterozoic ocean,” Philippi continued. “Until now, it was generally assumed that cyanobacteria carried out most of the nitrogen fixation then. We show that the role of purple sulfur bacteria in this process was likely underestimated.”
CAPTION
Salty springs at the lake bottom prevent mixing, resulting in a stable stratification. The upper meters contain oxygen but little nutrients. The lower layer is anoxic and rich in sulfide, creating a stable intermediate layer with steep concentration gradients of oxygen and sulfide. Here, the purple sulfur bacteria use solar energy to oxidize sulfide – and fix nitrogen.
CREDIT
Miriam Philippi
JOURNAL
Nature Communications
ARTICLE TITLE
Purple sulfur bacteria fix N2 via molybdenum-nitrogenase in a low molybdenum Proterozoic ocean analogue.
IMAGE: A MOUNTAIN LION ON A BLUFF OVERLOOKING LOS ANGELES. BY TRACKING THE WHEREABOUTS OF 12 MOUNTAIN LIONS BEFORE AND DURING THE COVID-19 PANDEMIC, ECOLOGISTS HAVE FOUND THAT THE RECLUSIVE SPECIES, BRIEFLY FREED OF THE NEED TO AVOID PEOPLE, ADOPTED AN ENERGY-EFFICIENT ECONOMY OF MOVEMENT DURING LA'S SHUTDOWN IN SPRING 2020.view more
CREDIT: NATIONAL PARK SERVICE
As people sheltered in place at the onset of the COVID-19 pandemic, sightings of wildlife in urban areas helped spawn a meme, “Nature is healing,” that reflected an intuitive belief: Carnivores were stretching their legs, and their ranges, by expanding into long-lost territory.
But new research from the University of Nebraska–Lincoln and National Park Service shows that mountain lions in Greater Los Angeles, when briefly spared the proximity of people, instead responded with an economy of movement that also reveals the costs of living near them.
“We saw a potential silver lining with COVID, which obviously has been generally a negative thing for everyone,” said John Benson, the study’s lead author and assistant professor of vertebrate ecology at Nebraska. “We saw an opportunity to get a better sense of how human disturbance and human activities influence animal behavior.”
Over a 43-day span that stretched from late March to early May of 2020, GPS-collared mountain lions in and around Los Angeles actually occupied smaller territories, and generally moved less, than they did before the pandemic. That span coincided with a statewide stay-at-home order and the closing of most parks around LA, including those favored by the famously reclusive species.
“There was this popular perception that animals were going to start running free, expanding their home ranges, moving greater distances, colonizing cities, coming into areas where they didn’t used to be,” Benson said. “But that goes against theory — the theory that animals should move as efficiently as possible.
“It actually makes sense that when you don’t have to dodge around as many humans, you could use the landscape more efficiently. Without humans, you don’t have to take a circuitous route to get from one place to another.”
The team tracked 12 mountain lions that had previously been collared with GPS locators by Jeff Sikich and Seth Riley of the National Park Service. Depending on the individual animal, those collars had already yielded between one and eight years of pre-pandemic data. That allowed the team to compile a distribution of past 43-day windows against which to compare the mountain lions’ space use and movement in the 43 days of spring 2020.
The researchers discovered that the home ranges of four resident mountain lions shrank considerably during the early days of the pandemic. After recording the locations of three mountain lions every two hours, the team also found that they were generally traveling shorter distances — in some cases, half or even a third as much as they did prior to the pandemic.
That matters, Benson said, because it helps quantify just how much energy mountain lions in Greater Los Angeles are expending to avoid people — energy they need to hunt for prey and search for mates. Though LA ranks as the largest metropolitan area in North America to house a wild felid of the mountain lion’s size, the 12 animals tagged by the research team probably represent a relatively sizable proportion of those still remaining there. A population that small is in danger of going locally extinct, he said, with any stressors taking ever-greater tolls as the population declines.
“Any additional stressor — like needing to modify your movement patterns, which could come with a cost of finding prey, getting enough to eat, mating, whatever it is — could be the stressor that tilts the balance toward the extinction process,” Benson said.
The beginning of the pandemic also presented a unique opportunity to tease apart whether wildlife is still motivated to avoid human infrastructure even when its builders have largely abandoned it, at least for a short while.
“People call it the ‘human footprint,’” Benson said. “We thought, ‘Here’s a chance to take the foot out of the footprint and see what animals are responding to.’”
CAPTION
With the ability to climb trees and an evolutionarily honed ability to hide, mountain lions are adept at avoiding humans. By tracking the whereabouts of 12 mountain lions before and during the COVID-19 pandemic, ecologists have found that the reclusive species, briefly freed of the need to avoid people, adopted an energy-efficient economy of movement during LA's shutdown in spring 2020.
CREDIT
National Park Service
So the team, which included Virginia Tech’s Heather Abernathy, decided to investigate how frequently mountain lions crossed park trails and major roads, including freeways, before versus early in the pandemic. As expected, a sample of seven mountain lions did crisscross the park trails more often in spring 2020, signaling that the presence of humans was, in fact, the main deterrent.
But a sample of 10 mountain lions continued avoiding primary and even intermediate-sized roads, despite a documented drop in traffic. Why the disparity? For starters, Benson said, the potential penalty for encountering foot traffic is much lower than it is for vehicle traffic. The team also suspects that the latter, though lower than usual, remained daunting enough to keep the mountain lions at bay. That was especially likely on Interstate 405, one of the busiest U.S. freeways and one that has historically acted as a hard border on the home ranges of neighboring mountain lions.
“The fact is that the roads in Southern California, especially big roads like freeways, are major barriers to movement for all kinds of wildlife, including mountain lions,” said Riley, also an adjunct faculty member at the University of California, Los Angeles. “The traffic was reduced, certainly, but there was still plenty of use occurring, and the barrier effect doesn’t just disappear.”
One of the tracked mountain lions, surrounded by busy freeways on three sides, occupies what may be the smallest home range ever recorded for an adult male: about 8 square miles, a fraction of the roughly 150 square miles enjoyed by a typical counterpart. Benson said the case study illustrates a paradox that makes sense in the light of theory: a carnivore, already confined to an artificially small range by human disturbance, choosing to occupy an even smaller range when that disturbance abates.
Human-created boundaries, and the effort that mountain lions exert to avoid the people dwelling within them, might be exacerbating human-wildlife conflicts in equally paradoxical ways. Avoiding people is necessary and good to some extent, Benson said, given that “bad things usually happen when we get annoyed by mountain lions.” Yet the energy they expend to do so might ironically increase human-wildlife conflict, he said, if high energy demands are leading them to seek additional food sources.
“This idea of coexistence — that if they stay out of our way, everyone’s happy — maybe it’s not that rosy,” he said, “if it causes them to burn more energy and then potentially makes them more likely to actually attack livestock or pets. This is not something we documented or investigated with our current study, but it would be an interesting hypothesis to test with future research.
“Does it have unintended consequences that we can’t control? I think that may be a good thing to look at and re-evaluate.”
The researchers reported their findings in the journal Ecological Solutions and Evidence.
JOURNAL
Ecological Solutions and Evidence
SUBJECT OF RESEARCH
Animals
ARTICLE TITLE
Mountain Lions Reduce Movement, Increase Efficiency During the Covid-19 Shutdown
ARTICLE PUBLICATION DATE
6-Aug-2021
Why lockdown in Africa does not work as a first COVID-19 pandemic response
IMAGE: DURING BETTER TIMES, AFRICAN COUNTRIES CAN IMPLEMENT SOCIAL MEASURES, FOLLOWED BY OTHER NON-MEDICAL INTERVENTIONS AT THE START OF A PANDEMIC, RATHER THAN LOCKDOWNS AS A FIRST RESPONSE, SAYS PROFESSOR NICHOLAS NGEPAH. HIS STUDY OF SOCIAL MEASURES THAT CAN CONTAIN THE SPREAD OF A PANDEMIC, INCLUDED ECONOMIC DATA FROM 53 AFRICAN COUNTRIES INCLUDING SOUTH AFRICA. THE FIRST RECORDED CASE IN EACH COUNTRY TO 4 JANUARY, 2021 WERE INCLUDED.view more
CREDIT: THERESE VAN WYK
In an African pandemic it is more productive to consider lockdowns, after using other non-medical measures first, Especially in countries with high levels of poverty and corruption, says Prof Nicholas Ngepah, a Professor of Economics at the University of Johannesburg in South Africa.
Looking at the socio-economic conditions of African countries, we can see reasons for this, he says.
“What has happened during COVID-19 is that people get locked down by strict regulations. But the majority don’t have the nutrition, basic economic opportunities and infrastructure to cope. It becomes almost impossible for a poor person to keep the rules of the lockdown.
“The rules are very strict, but people will contravene them. They will be willing to fight with public order policing to get their livelihoods going.”
This is the experience in South Africa and many other African countries, he says. The poorest are most conflicted with lockdown regulations.
Ngepah’s research titled “What lessons Africa can learn from the social determinants of COVID-19 spread, to better prepare for current and future pandemics on the continent” is published in a special issue of African Development Review.
The study is based on data from 53 African countries including South Africa. The first recorded case in each country to 4 January 2021 was included.
The latest pandemic
“The rich and the middle class would appear to comply well with lockdowns. But this is because they are able to rush to the shops and empty them. Poor people cannot empty shops because they don’t have money.
“Rich people have resources to keep going, so their desperate actions only show much later. With poor people, their desperation shows immediately, because they have no reserves to fall back on.”
“When a large part of your population is on the wrong end of inequality, it follows that many will not trust state machinery.
“If in good times, the state was not taking care of poor people, and now in bad times it comes along with very strict rules… it doesn’t work. The poor need good services, support and infrastructure before pandemics hit.”
The desperation during a pandemic lockdown has implications, he says. Governance and political stability are affected.
“It’s intuitive. If you are constrained without an alternative means of survival, you will end up revolting.”
Another reason the poor are unlikely to obey strict lockdowns, is corruption.
With high levels of corruption, impoverished workers feel they are asked to pay for the corruption of the rich in government, he says.
In South Africa, COVID-19 is the latest arrival in a long line of challenges. The country has pandemic levels of inequality, poverty, corruption, unemployment, and HIV/AIDS.
Poverty and spread
Quality policymaking is crucial in dealing with current and future pandemics, he says.
“In my view, the need to better take care of the poor has not been driven home in many policymakers’ minds yet, despite the COVID-19 pandemic,” says Ngepah.
“Economic deprivation by itself has a positive relationship with the spread of disease and mortality.
"In good times, poverty reduction policies should be taken seriously. Because poverty directly influences how successful stringency measures will be.
"Poverty also influences to what extent sanitation services will limit the spread of the disease.
“It also directly influences the rate of internal population dynamics, or internal migration. This is where the rural poor flee to the cities for economic opportunities – and create dense, very poor neighborhoods,” he says.
In South Africa, the ‘townships’ which receive these people, often do not have adequate water, power or sanitation services.
To slow the spread of the COVID-19 and future pandemics, African policymakers and governments need use social and economic measures available to them. These non-medical interventions can be very effective, he says.
Public capacity for testing
Firstly, enhance public health capacity for effective, swift testing for the pandemic disease so that cases are isolated early enough to deal with. This will limit spread and mortality.
Economic health of the most constrained
Secondly, before thinking about stringent lockdowns, first check the economic health of your population. Make sure that the basic capacities are in place, for them to be able to cope during the period of lockdown, he says.
“For a country with high levels of inequality like South Africa, you can’t just wake up in the morning, declare lockdown and send soldiers and police to try and enforce it, without checking first how the more deprived people are living. Especially in South Africa where we know that more than half the population is living below the poverty line.”
Thirdly, managing the international border swiftly is most important to limiting spread.
“Managing the border is about being able to foresee a problem and act before the pandemic spreads into communities. You need to close borders early, while quarantine measures will still work. This gives you breathing space to deal with internal issues before lockdown. It also creates time for the poor to prepare as best as they can with the very constrained resources they have.
“For example, before lockdown you would already put safety nets in place to say this is how we will cater for the poor during that time. As opposed to what’s happening here, where the poor are crying,” he says.
Quality services where most need is
Then in the medium and longer term, management of internal population dynamics is crucial. This can limit the growth of extremely poorneighborhoods which are ideal for the spread of any pandemic.
If poor people have services, jobs and good infrastructure where they are, the motivation to move into a disadvantaged area closer to a big city is lower.
“It is about pro-poor infrastructure and decentralization. It isn’t just about bringing key public services into poor neighborhoods. It is also about moving and redistributing government services so that they are closer to the majority of those who are most in need of them.”
As an example, currently a district police headquarters may be in a well-to-do suburb, with a badly resourced satellite station in a township. Ngepah suggests doing the opposite.
Put the well-resourced police headquarters in the township, where the majority who need it, are close by. The rich and middle class can go online or drive 30 minutes in their cars because physical proximity is often not a barrier for them, he says.
Sanitation infrastructure and services
Sanitation is probably the most important non-medical aspect of infrastructure before and during a pandemic, says Ngepah.
“On one hand, it is about habits. Most people learned about proper washing of hands during the pandemic. During good times, the government should prioritize this as something important. This pandemic came, but it is not the first communicable disease outbreak that we have had,” says Ngepah.
The second aspect of sanitation is the infrastructure.
“Don’t say wash hands and give all the lessons about handwashing - when the tap is not flowing, when there are no services relating to sanitation.”
The actual role of alcohol in the pandemic
In South Africa, debates have raged about the role of alcohol and social interaction in spreading COVID-19. But Ngepah says that managing internal population dynamics is more important than the issue of alcohol itself. This is because internal migration creates impoverished neighborhoods with bad or no services.
“If you ban alcohol, without checking the role of alcohol in the whole equation, you might not be getting the right result. Before you ban alcohol, check what the channel of transmission is. The channel of transmission of the corona virus pandemic is the socializing with alcohol, rather than alcohol by itself.
“When we are talking about spread, the real question is, how does alcohol spread the disease? My view, which is not proven in this study, but it is in line with other research, is that your social interaction route is important.
“Because we are trying to balance restraining COVID with the health of the economy and job losses. So we have to look at private alcohol consumption versus social alcohol consumption, before making decisions,” he says.
Support to small businesses, relaxation of labor laws
Most economies have seen job losses and rising unemployment during the pandemic. Small businesses, which have much lower reserves than large ones, have been hard hit in South Africa.
“Liquidity support to small business is paramount as a first measure to keep them afloat and prevent job losses,” says Ngepah.
“At the same time, in the context of high unemployment, we should be less stringent with small businesses when it comes to labor laws. Because small businesses usually have very thin margins. And if they have to employ more people, we have to have some trade-offs.
“Before COVID-19, the government had been trying to pilot a program to assist. They intervene by giving some resources to companies in exchange for skills development on the job. These are the things government should be thinking about to ease the burden of the wage bill in small enterprises in South Africa,” he says.
The most efficient way of managing pandemics is to get a handle on economic deprivation, he adds. Especially for a national or city government with the majority living in poverty,
Ngepah concludes: “Take care of the poor all the time, so they are well placed to obey you when you put rules in place. If this is done in normal times, then we will stress less during pandemics.
"In the military, they say that those who stress in times of peace to prepare themselves, will bleed less in times of war.”
JOURNAL
African Development Review
DOI
10.1111/1467-8268.12530
METHOD OF RESEARCH
Data/statistical analysis
SUBJECT OF RESEARCH
People
ARTICLE TITLE
What lessons Africa can learn from the social determinants of COVID-19 spread, to better prepare for current and future pandemics on the continent
ARTICLE PUBLICATION DATE
4-May-2021
CAN YOU SAY; LACK OF INFRASTRUCTURE
Hybrid cars are twice as vulnerable to supply chain issues as gas-powered models
The global computer chip shortage has hit car manufacturers especially hard, indicating the importance of supply chain resilience. Yet, for hybrid electric vehicles, it isn’t clear how their production could be impacted by fluctuating supplies and high prices. To get a grasp of these vulnerabilities compared to those for gas-powered models, researchers reporting in ACS’ Environmental Science & Technology conducted a thorough analysis, finding that hybrid models have twice the vulnerability to supply chain disruptions.
Supply chain weaknesses were brought to the forefront during the COVID-19 pandemic, especially for industries relying on electronics, as the flow of raw materials slowed or sometimes stopped. On top of that, shifting consumer values and tougher environmental regulations have resulted in more people buying hybrid vehicles. The batteries in these cars require rare metals that, depending on their supplies, can have volatile and unpredictable prices. But there are other scarce elements and materials that may be used in smaller amounts in hybrid models versus conventional gas vehicles, raising the question of how these vehicles really compare with regard to supply chain vulnerabilities. Although previous studies reported lists of the elements used in conventional cars’ parts, similar information on the parts used in hybrid vehicles is lacking. So, Randolph Kirchain and colleagues wanted to develop a comprehensive comparison of the elements and compounds that go into all the parts in gas-powered, self-charging hybrid and plug-in hybrid cars, calculating each of the three vehicles’ materials cost vulnerability.
The researchers collected information on the compounds in the more than 350,000 parts used to build seven vehicles from the same manufacturer with different levels of electrification, including four sedans and three sport utility vehicles (SUVs). Then, they calculated the amount of the 76 chemical elements present, as well as a few other materials, in each car type. To develop a monetary metric for vulnerability, the team considered the weight of each component, along with its average price and price volatility between 1998 and 2015. The results showed that self-charging hybrid and plug-in hybrid vehicles have twice the raw material cost risks, which equates to an increase of $1 billion for a fleet of a million sedans and SUVs, compared to conventional models. The largest contributors to the increase in cost risks were battery-related elements, such as cobalt, nickel, graphite and neodymium; however, changes to the exhaust and transmission systems in hybrid vehicles reduced the impact of palladium and aluminum, respectively. The researchers suggest that as manufacturers ramp up electric vehicle production to meet demand, they can reduce raw material cost risks with long-term supplier contracts, substitute some materials or recycle others.
The abstract that accompanies this paper can be viewed here.
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INSTITUT NATIONAL DE LA RECHERCHE SCIENTIFIQUE - INR
IMAGE: INRS PROFESSOR MONIQUE LACROIX IS AN EXPERT IN SCIENCES, APPLIED TO FOOD.view more
CREDIT: CHRISTIAN FLEURY
Most products enriched with probiotics and protein are made with dairy products. However, consumer demand for plant protein is growing. The nutritional value of these proteins must therefore be improved to be comparable to that of animal proteins.
A team led by Professor Monique Lacroix at the Institut national de la recherche scientifique (INRS) has demonstrated that fermenting drinks fortified with pea and rice proteins yields the same quality of protein as casein, an animal protein found in milk. The findings were published in the Journal of Food Science.
Increasing protein intake
Using plant proteins poses some challenges. For one thing, plant proteins are deficient in certain essential amino acids necessary for the body’s proper functioning. Since the body itself doesn’t produce these amino acids, they must come from food. The combination of pea and rice proteins helped counterbalance essential amino acid deficiencies through complementarity.
That said, plant proteins are also harder to digest. “They often are non soluble in water and under globular. That means our digestive enzymes have more difficulty breaking them down. Animal proteins, on the other hand, usually take the form of elongated fibres that are easily processed by digestive enzymes,” said Professor Lacroix.
But when pea and rice proteins are added before the fermentation stage during production of a fermented beverage, they can be predigested by lactic acid bacteria (LAB). This allows the production of peptides (protein fragments) resulting from the breakdown of proteins during fermentation, thereby facilitating their absorption during digestion.
The study, carried out in collaboration with Bio-K+, used a specific formulation containing the bacteria Lactobacillus acidophilus CL1285, L. casei LBC80R and L. rhamnosus CLR2. These LAB, whose probiotic functions have been scientifically proven and licensed by Health Canada, were used in this study to produce the fermented drink enriched with pea and rice proteins.
Protecting one's own health is generally an important motive for voluntarily wearing a face mask during the pandemic. However, for younger people the desire to protect others plays a decisive role in their decision to wear a mask. These are the conclusions of a study recently published in PLOS ONE by an interdisciplinary team of economists as well as behavioural and health scientists from Germany and Switzerland, based on a survey of employees from two Swiss hospitals. The findings of the study suggest that public health campaigns would benefit from targeted communication strategies – both in the context of wearing face masks during the COVID-19 pandemic and beyond.
Study among health care workers In the face of the continuing COVID-19 pandemic, governments worldwide have either recommended or mandated wearing face masks in public areas, at least temporarily. Although scientific findings confirm that wearing face masks saves lives during the pandemic, public support for this measure as well as the willingness to wear masks differ widely.
To investigate what motivates people to voluntarily wear a mask, the economists and behavioural researchers Dr Ankush Asri, Dr Viola Asri, Dr Baiba Renerte and Professor Urs Fischbacher from the University of Konstanz, in collaboration with co-authors from the health sector, conducted a survey among 840 employees of two Swiss hospitals. In addition to questions on mask-wearing behaviour, participants were also asked to self-assess their risk behaviour and altruism.
In the early stages of the pandemic, healthcare workers were a suitable group for this study because they had good access to masks, were used to wearing them and were well informed about the coronavirus. "The uniformity of such practical factors, which can also influence the decision to wear a mask, allowed us to focus on exploring other possible motivations among the respondents," explains Dr Baiba Renerte.
Self-protection as the main motivation The survey was carried out in June and July 2020, after the first wave of SARS-CoV-2 infections had abated in Switzerland. The regions in which the two hospitals are located had different infection rates during the first wave of the pandemic – one had higher and the other lower case rates. Nevertheless, the same provisions had been set out in both regions at the time of the survey: While at work, it was mandatory for hospital staff to wear a face mask, while wearing a mask in public spaces was largely voluntary.
"Our surveys show that self-protection is generally an important motivation for wearing masks," reports Dr Ankush Asri. The results indeed confirm that more people who describe themselves as risk-averse voluntarily wear a protective mask than those who describe themselves as risk-takers. In both regions, the results were the same, regardless of how much each region was affected by the first wave of the pandemic.
Different motives in different age groups In a more detailed analysis of the survey data, which additionally distinguished between employees under and above 45 years of age, the researchers found another important motivation. Among those under 45 from the more affected region, there was a correlation between self-rated altruism and mask-wearing behaviour: A higher percentage of younger employees who described themselves as altruistic said they voluntarily wear masks, compared to those who considered themselves to be less altruistic.
"We interpret this correlation such that the central motivation to wear masks for older staff is to avoid getting infected, because they are more at risk for a severe infection. Younger employees, on the other hand, may be less concerned about infecting themselves than about infecting someone at higher risk," Dr Viola Asri offers a possible explanation for the observation.
Differences in motivations between population groups, such as those measured here, could be relevant for information campaigns aimed at recommending health-related behaviours to the general public – whether in the context of the COVID-19 pandemic or in other situations. Consequently, they should be taken into account, where known, in order to achieve the greatest possible impact, the authors conclude. Key Facts:
Original publication: Ankush Asri, Viola Asri, Baiba Renerte, Franziska Föllmi-Heusi, Joerg D. Leuppi, Juergen Muser, Reto Nüesch, Dominik Schuler, Urs Fischbacher (2021) Wearing a mask – for yourself or for others? Behavioral correlates of mask wearing among COVID-19 frontline workers. PLOS ONE; DOI: https://doi.org/10.1371/journal.pone.0253621
Surveys at two Swiss hospitals on voluntarily wearing face masks
Findings of the survey: Protecting one's own health is generally an important motive for voluntarily wearing a face mask. For younger people, the desire to protect others also plays a decisive role
Recommendations of the researchers: For the best possible effect, the content of public health campaigns should be tailored to different population groups
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- uni.kn/en
JOURNAL
PLoS ONE
DOI
10.1371/journal.pone.0253621
METHOD OF RESEARCH
Survey
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Wearing a mask—For yourself or for others? Behavioral correlates of mask wearing among COVID-19 frontline workers
If you put a bottle of beer in a big bathtub full of ice-cold water, it won’t be long before you can enjoy a cold beer. Physicists discovered how this works more than a hundred years ago. Heat exchange takes place through the glass bottle until equilibrium is reached.
However, there are other systems, especially quantum systems, that don’t find equilibrium. They resemble a hypothetical beer bottle in a bath of ice-cold water that doesn’t always and inevitably cool to the temperature of the bath water, but rather reaches different states depending on its own initial temperature. Until now, such systems have puzzled physicists. But Nicolò Defenu, a postdoc at the ETH Zurich Institute for Theoretical Physics, has now found a way to elegantly explain this behaviour.
A more distant influence
Specifically, we are talking about systems in which the individual building blocks influence not only their immediate neighbours, but also objects further away. One example would be a galaxy: the gravitational force of their individual stars and planetary systems acts not only on the neighbouring celestial bodies, but far beyond that – albeit ever more weakly – on the other components of the galaxy.
Defenu’s approach begins by simplifying the problem to a world with a single dimension. In it, there is a single quantum particle that can reside only in very specific locations along a line. This world resembles a board game like Ludo, where a little token hops from square to square. Suppose there is a game die whose sides are all marked “one” or “minus one”, and suppose the player whose token it is now rolls the die over and over again in succession. The token will hop to a neighbouring square, and from there it will either hop back or else on to the next square. And so on.
The question is, What happens if the player rolls the die an infinite number of times? If there are only a few squares in the game, the token will return to its starting point every now and then. However, it is impossible to predict exactly where it will be at any given time because the throws of the die are unknown.
Back to square one
It’s a similar situation with particles that are subject to the laws of quantum mechanics: there’s no way to know exactly where they are at any given time. However, it is possible to establish their whereabouts using probability distributions. Each distribution results from a different superposition of the probabilities for the individual locations and corresponds to a particular energy state of the particle. It turns out that the number of stable energy states coincides with the number of degrees of freedom of the system and thus corresponds exactly to the number of allowed locations. The important point is that all the stable probability distributions are non-zero at the starting point. So at some point, the token returns to its starting square.
The more squares there are, the less often the token will return to its starting point; eventually, with an infinite number of possible squares, it will never return. For the quantum particle, this means there are an infinite number of ways in which the probabilities of the individual locations can be combined to form distributions. Thus, it can no longer occupy only certain discrete energy states, but all possible ones in a continuous spectrum.
None of this is new knowledge. There are, however, variants of the game or physical systems where the die can also contain numbers larger than one and smaller than minus one, i.e. the steps allowed per move can be larger – to be precise, even infinitely large. This fundamentally changes the situation, as Defenu has now been able to show: in these systems, the energy spectrum always remains discrete, even when there are infinite squares. This means that from time to time, the particle will return to its starting point.
Peculiar phenomena
This new theory explains what scientists have already observed many times in experiments: systems in which long-range interactions occur do not reach a stable equilibrium, but rather a meta-stable state in which they always return to their initial position. In the case of galaxies, this is one reason they develop spiral arms rather than being uniform clouds. The density of stars is higher inside these arms than outside.
An example of quantum systems that can be described with Defenu’s theory are ions, which are charged atoms trapped in electric fields. Using such ion traps to build quantum computers is currently one of the largest research projects worldwide. However, for these computers to really deliver a step change in terms of computational power, they will need a very large number of simultaneously trapped ions – and that is exactly the point at which the new theory becomes interesting. “In systems with a hundred or more ions, you would see peculiar effects that we can now explain,” says Defenu, who is a member of ETH Professor Gian Michele Graf’s group. His colleagues in experimental physics are getting closer every day to the goal of being able to realise such formations. And once they’ve got there, it might be worth their while to have a cold beer with Defenu.
JOURNAL
Proceedings of the National Academy of Sciences
DOI
10.1073/pnas.2101785118
METHOD OF RESEARCH
Data/statistical analysis
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Metastability and discrete spectrum of long-range systems
