Mouthwashes, oral rinses may inactivate human coronaviruses

PENN STATE

Research News

HERSHEY, Pa. -- Certain oral antiseptics and mouthwashes may have the ability to inactivate human coronaviruses, according to a Penn State College of Medicine research study. The results indicate that some of these products might be useful for reducing the viral load, or amount of virus, in the mouth after infection and may help to reduce the spread of SARS-CoV-2, the coronavirus that causes COVID-19.

Craig Meyers, distinguished professor of microbiology and immunology and obstetrics and gynecology, led a group of physicians and scientists who tested several oral and nasopharyngeal rinses in a laboratory setting for their ability to inactivate human coronaviruses, which are similar in structure to SARS-CoV-2. The products evaluated include a 1% solution of baby shampoo, a neti pot, peroxide sore-mouth cleansers, and mouthwashes.

The researchers found that several of the nasal and oral rinses had a strong ability to neutralize human coronavirus, which suggests that these products may have the potential to reduce the amount of virus spread by people who are COVID-19-positive.

"While we wait for a vaccine to be developed, methods to reduce transmission are needed," Meyers said. "The products we tested are readily available and often already part of people's daily routines."

Meyers and colleagues used a test to replicate the interaction of the virus in the nasal and oral cavities with the rinses and mouthwashes. Nasal and oral cavities are major points of entry and transmission for human coronaviruses. They treated solutions containing a strain of human coronavirus, which served as a readily available and genetically similar alternative for SARS-CoV-2, with the baby shampoo solutions, various peroxide antiseptic rinses and various brands of mouthwash. They allowed the solutions to interact with the virus for 30 seconds, one minute and two minutes, before diluting the solutions to prevent further virus inactivation. According to Meyers, the outer envelopes of the human coronavirus tested and SARS-CoV-2 are genetically similar so the research team hypothesizes that a similar amount of SARS-CoV-2 may be inactivated upon exposure to the solution.

To measure how much virus was inactivated, the researchers placed the diluted solutions in contact with cultured human cells. They counted how many cells remained alive after a few days of exposure to the viral solution and used that number to calculate the amount of human coronavirus that was inactivated as a result of exposure to the mouthwash or oral rinse that was tested. The results were published in the Journal of Medical Virology.

The 1% baby shampoo solution, which is often used by head and neck doctors to rinse the sinuses, inactivated greater than 99.9% of human coronavirus after a two-minute contact time. Several of the mouthwash and gargle products also were effective at inactivating the infectious virus. Many inactivated greater than 99.9% of virus after only 30 seconds of contact time and some inactivated 99.99% of the virus after 30 seconds.

According to Meyers, the results with mouthwashes are promising and add to the findings of a study showing that certain types of oral rinses could inactivate SARS-CoV-2 in similar experimental conditions. In addition to evaluating the solutions at longer contact times, they studied over-the-counter products and nasal rinses that were not evaluated in the other study. Meyers said the next step to expand upon these results is to design and conduct clinical trials that evaluate whether products like mouthwashes can effectively reduce viral load in COVID-19-positive patients.

"People who test positive for COVID-19 and return home to quarantine may possibly transmit the virus to those they live with," said Meyers, a researcher at Penn State Cancer Institute. "Certain professions including dentists and other health care workers are at a constant risk of exposure. Clinical trials are needed to determine if these products can reduce the amount of virus COVID-positive patients or those with high-risk occupations may spread while talking, coughing or sneezing. Even if the use of these solutions could reduce transmission by 50%, it would have a major impact."

Future studies may include a continued investigation of products that inactive human coronaviruses and what specific ingredients in the solutions tested inactivate the virus.

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Janice Milici, Samina Alam, David Quillen, David Goldenberg and Rena Kass of Penn State College of Medicine and Richard Robison of Brigham Young University also contributed to this research.

The research was supported by funds from Penn State Huck Institutes for the Life Sciences. The researchers declare no conflict of interest.

 

NUS study reveals severe air pollution drives food delivery consumption and plastic waste

Poor outdoor air is a strong push factor in consumers' use of food delivery services in China

NATIONAL UNIVERSITY OF SINGAPORE

Research News

 

When the air outside is bad, office workers are more likely to order food delivery than go out for lunch, which in turn increases plastic waste from food packaging, according to a study by researchers from the National University of Singapore (NUS).

Associate Professor Alberto Salvo from the Department of Economics at the NUS Faculty of Arts and Social Sciences and an author of the study, said, "Plastic waste is a growing global environmental concern. While we see more research on the impact plastic pollution is having on the natural environment, there has been less work trying to understand the human behaviour that drives plastic pollution. This is where our study seeks to contribute - finding a strong causal link between air pollution and plastic waste through the demand for food delivery. Air quality in the urban developing world is routinely poor and in the past decade, the food delivery industry has been growing sharply. The evidence we collected shows a lot of single-use plastic in delivered meals, from containers to carrier bags."

The results of the study were published in the journal Nature Human Behaviour.

Air pollution drives demand for food delivery services

The NUS team, including Assoc Prof Liu Haoming and Assoc Prof Chu Junhong, focused their study on China, which is among the world's largest users of online food delivery platforms, with 350 million registered users. An estimated 65 million meal containers are discarded each day across China, with office workers contributing over one-half of demand.

The study surveyed the lunch choices of 251 office workers repeatedly over time (each worker for 11 workdays) in three often smog-filled Chinese cities - Beijing, Shenyang and Shijiazhuang - between January and June 2018. To complement the office-worker survey, the researchers also accessed the 2016 Beijing order book of an online food delivery platform, which broadly represented all market segments served by the food delivery industry - collecting observational data on 3.5 million food delivery orders from about 350,000 users.

Data from the survey and order book were then compared with PM2.5 measurements (fine particles less than 2.5 micrometres in diameter) during lunchtime periods from the air-monitoring network in all three cities. It was observed that PM2.5 levels during these periods were often well above the 24-hour US National Ambient Air Quality Standard of 35 μg/m³, making pollution highly visible. The researchers were careful to control for confounding factors such as economic activity.

Both data sources indicated a strong link between PM2.5 (haze) pollution and food delivery consumption. Correcting for weather and seasonal influences, the firm's order book revealed that a 100 μg/m³ increase in PM2.5 raised food delivery consumption by 7.2 per cent. The impact of a 100 μg/m³ PM2.5 shift on office workers' propensity to order delivery was six times larger, at 43 per cent.

Assoc Prof Chu from the Department of Marketing at NUS Business School elaborated, "Faced with smog or haze outside, a typical office worker at lunchtime can avoid exposure only by ordering food to be delivered to his or her doorstep. A broader base of consumers has more alternatives to avoiding the outdoor environment on a polluted day, for example, by using a home kitchen when at home. This explains why the impact of air pollution on food delivery is smaller in the firm's order book study than what we observed among workers, particularly those without access to a canteen in their office building. Nevertheless, we find the impact to be economically large also among the broader population served by the food delivery platform that we examined."

Air pollution control brings plastic waste co-benefits

Over 3,000 photos of meals were submitted by office workers, enabling the NUS team to quantify how much disposable plastic varies across different lunch choices, in particular, meals eaten at the restaurant versus those delivered to the office. The researchers estimated that a 100 μg/m³ PM2.5 increase raised a meal's disposable plastic use by 10 grams on average - equivalent to about one-third the mass of a plastic container. Photographs that were published as part of the study indicated that the average delivered meal used 2.8 single-use plastic items and an estimated 54 grams of plastic. The average dine-in meal used an estimated 6.6 grams of plastic, such as in chopstick sleeves or bottles.

Based on the order book, the researchers also estimated that on a given day, if all of China were exposed to a 100 μg/m³ PM2.5 increase in dose as is routinely observed in Beijing, 2.5 million more meals would be delivered, requiring an additional 2.5 million plastic bags and 2.5 million plastic containers.

Assoc Prof Liu from the Department of Economics said, "Our findings probably apply to other typically polluted developing-nation cities, such as in Bangladesh, India, Indonesia and Vietnam. Waste management practices vary widely, with wind blowing plastic debris away from uncovered landfills or plastic being discarded into rivers and from there into the ocean. So, with eight million tonnes of plastic estimated to enter the seas each year, our study speaks to a wider issue. Individuals protect themselves from - and show their distaste for - air pollution by ordering food delivery which often comes in plastic packaging. It is evident from our study that air pollution control can reduce plastic waste."

Moving forward, the researchers will continue working on behavioural feedback by which pollution begets pollution: in particular, to defend themselves from environmental pollution, humans use more natural resources and pollute more. As a recent example, the researchers note how concern over exposure to COVID-19 has led to booming demand for home-delivered meals which are predominantly packaged in plastic. They hope that their work will add to the voices calling for more environmentally friendly packaging and improved waste management.

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High social and ecological standards for chocolate

Research team including agroecologists from Göttingen University study conditions in Peruvian cocoa agroforestry systems

UNIVERSITY OF GÖTTINGEN

Research News

 

IMAGE: DR BEA MASS WITH COCOA POD (FRUIT OF THE COCOA TREE), FROM WHICH CHOCOLATE IS MADE view more 

CREDIT: DR BEA MAAS

Worldwide demand for food from the tropics that meets higher environmental and social standards has risen sharply in recent years. Consumers often have to make ethically questionable decisions: products may be available to the global market through child labour, starvation wages or environmental destruction. Building on an interdisciplinary project in Peru, an international research team with the participation of the University of Göttingen has now published an overview article on the transition to responsible, high-quality cocoa production. Chocolate is made from cocoa beans, and because cocoa is originally from Peru, using indigenous varieties means a premium price can be charged. A large cooperative for small-holder farmers in northern Peru stands for social and ecological improvements with the help of organic and fair-trade certification, as well as the cultivation of native varieties in species-rich cocoa agroforestry systems. The work was published as a "Perspective" article in the journal Trends in Ecology and Evolution.

Shade trees in traditional cocoa agroforestry systems improve conditions for cocoa growth and promote biodiversity, for instance of birds. However, these trees are increasingly being removed to increase productivity, even though moderate, partial shade does not significantly reduce productivity. In addition, proven high-yielding varieties are imported, although there are unique indigenous varieties in Peru that may be associated with a particular trade advantage. The researchers' project group is working together with the cooperative Norandino Ltda. in Piura, northern Peru, which is committed to working towards developing high social and ecological standards. It represents 5,400 smallholder farmers and stands for sustainable production that pursues both ecological and economic goals. Furthermore, the cooperative is committed to fighting all forms of discrimination. The result is ecologically certified and fair-trade chocolate of a high standard, which achieves up to twice the regular market price, protects smallholder farmers against market fluctuations and moves towards the greater use of local cocoa bean varieties in the future.

Dr Bea Maas, first author of the article and now at the University of Vienna, emphasises: "Large cooperatives that stand for high social, economic and ecological standards in production should receive more support." Carolina Ocampo-Ariza and Professor Teja Tscharntke from the Agroecology group at the University of Göttingen add: "Such exemplary initiatives that benefit the livelihoods of smallholder farmers while maximising nature conservation should be the focus of interdisciplinary research now more than ever before."

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Original publication: Bea Maas et al. Transforming Tropical Agroforestry towards High Socio-Ecological Standards. Trends in Ecology and Evolution 2020. https://doi.org/10.1016/j.tree.2020.09.002.

 

Fear of COVID-19 raises risk of depression among Soweto's deprived communities

South Africa's national lockdown introduced serious threats to the public's mental health in a country with high levels of psychological burden, according to new research

CAMBRIDGE UNIVERSITY PRESS

Research News

 

A STUDY into the impact of the COVID-19 lockdown on the mental health of people in Soweto has found a significant link between symptoms of depression and how likely people felt they were to be infected.

Researchers also found that both the perceived risk of infection and the likelihood of depression and anxiety increased among people who had suffered childhood trauma and among those already suffering the effects of poverty and deprivation.

Associations between depression and issues such as hunger, violence, poor healthcare, and high rates of poverty have long been recognised, but this study is the first to look at the mental health effects of the pandemic and national lockdown in South Africa under those conditions.

Researchers spoke to more than 200 adults who were already part of a long-term health study in Soweto. This had surveyed 957 people in the months before the pandemic, measuring their risk of mental ill-health, including depression, by asking them to score their mood, feelings, and behaviour. The participants were also asked about day-to-day adversity, such as family strife, poverty, deprivation, and violence; about their ways of coping, including support from friends, family, and church; and about adverse experiences in childhood like abuse, neglect, and household dysfunction.

The follow-up survey was carried out over the phone after the first six weeks of lockdown. It asked people to score themselves against major symptoms of depression during the previous month, assessed their knowledge of COVID-19 and how to protect against it, and asked whether they thought they were at less risk, the same risk or a greater risk than others.

The results, published in the Cambridge journal, Psychological Medicine, showed people were two times as likely to experience significant depressive symptoms for every step increase in their perceived risk from COVID-19. It was also found that those with a history of childhood trauma were more likely to have a higher perceived risk of contracting the virus.

In all, 14.5 per cent of those surveyed were found to be at risk of depression, with 20 per cent indicating that COVID-19 caused them deep worry, anxiety, or led to them 'thinking too much' about the virus and its impact.

While the majority did not think COVID-19 affected their mental health, both the data and what people said about its impact on their lives suggested otherwise.

Dr. Andrew Wooyoung Kim of Northwestern University, who co-directed the study for the Developmental Pathways for Health Research Unit at the University of the Witwatersrand, said: "This discrepancy may be due to different ideas of mental health, including mental health stigma.

"While participants believed that the pandemic did not affect their mental health or their 'mind', the strong relationship between perceived risk and depressive symptoms raises the concern that they may not be aware of the potential threats to their mental health during COVID-19."

These threats were amplified by other pre-existing adversities, said Dr Kim and his colleagues, including hunger and violence, an overburdened healthcare system, a high prevalence of chronic and infectious disease, and alarming rates of poverty and unemployment.

They argue that the pressures of COVID-19 and lockdown risk adding to the already high levels of mental illness among people in South Africa, where one in three experience some kind of mental disorder in their lifetimes and where only 27 per cent of patients with a severe mental illness receive treatment.

Dr Kim said: "Our study re-emphasizes the importance of prioritizing and provisioning accessible mental health resources for resource-limited communities in Soweto and across South Africa."

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Global food production threatens the climate

Use of nitrogen fertilizers in agriculture causes an increase in nitrous oxide concentration in the atmosphere - Comprehensive study with KIT participation in Nature

KARLSRUHER INSTITUT FÜR TECHNOLOGIE (KIT)

Research News

 

IMAGE: USE OF FERTILIZERS IN AGRICULTURE, IN PARTICULAR, IS RESPONSIBLE FOR THE INCREASE IN THE CLIMATE-DAMAGING NITROUS OXIDE CONCENTRATION IN THE ATMOSPHERE. view more 

CREDIT: (PHOTO: MARKUS BREIG, KIT)

Concentration of dinitrogen oxide - also referred to as nitrous oxide - in the atmosphere increases strongly and speeds up climate change. In addition to CO2 and methane, it is the third important greenhouse gas emitted due to anthropogenic activities. Human-made nitrous oxide emissions are mainly caused by the use of fertilizers in agriculture. Growing demand for food and feed in future might further increase the emissions. This is one finding of an international study published in Nature, in which Karlsruhe Institute of Technology (KIT) was one of the partners. (DOI: 10.1038/s41586-020-2780-0)

Dinitrogen oxide (N2O), also called nitrous oxide, is about 300 times as climate-damaging as carbon dioxide. It stays for about 120 years in the atmosphere. Although it exists in the form of traces only, it has a very strong greenhouse effect and superproportionally contributes to anthropogenic climate change. Nitrous oxide concentration in the atmosphere today already is about 20% higher than the pre-industrial value. In past decades, increase has accelerated due to emissions from various anthropogenic activities. In total, worldwide N2O emissions in 2016 were about ten percent higher than those of the 1980s. An international study coordinated by researchers from Auburn University in Alabama/USA now presents the most comprehensive evaluation of all nitrous oxide sources and sinks so far. Under the title "A comprehensive quantification of global nitrous oxide sources and sinks," it is now reported in Nature. The conclusion: As a result of strongly increasing nitrous oxide emissions, the climate goals of the Paris Agreement are at stake.

"The increase in nitrous oxide concentration in the atmosphere is mainly caused by the use of nitrogen-containing fertilizers. These include both synthetic fertilizers and organic fertilizers from animal excretions," says ecosystems researcher Almut Arneth, Professor of the Atmospheric Environmental Research Division of KIT's Institute of Meteorology and Climate Research (IMK-IFU), KIT's Campus Alpine in Garmisch-Partenkirchen. She participated in the study. "From 2007 to 2016, agricultural production caused about 70% of anthropogenic global increase in N2O emissions since the 1980s." As global demand for food and feed is growing, researchers fear that also global N2O concentration will further increase and contribute to global warming.

N2O Emissions Decreased in Europe

According to the study, anthropogenic nitrous oxide emissions are highest in East and South Asia, Africa, and South America. Increases are particularly high in threshold countries, such China, India, and Brazil, where crop cultivation and animal husbandry have grown strongly. In Europe, by contrast, anthropogenic N2O emissions decreased, both in agriculture and chemical industry. Scientists explain this decrease by various incentives and protection measures. Agriculture in many West European countries has started to use nitrogen more efficiently in order to reduce water pollution, among others. "Our work provides an in-depth understanding of the N2O budget and its impacts on climate," Arneth explains. "It also shows that there are ways to reduce emissions, such as measures in agriculture that concern both production and consumption. Such measures do not only benefit the climate, but also biodiversity and human health."

57 scientists from 48 research institutions in 14 countries were involved in the study "A comprehensive quantification of global nitrous oxide sources and sinks" managed by Professor Hanqin Tian from Auburn University. The study was made within the framework of the Global Carbon Project and the International Nitrogen Initiative.

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Original Publication

Hanqin Tian et al.: A comprehensive quantification of global nitrous oxide sources and sinks. Nature, 2020. DOI: 10.1038/s41586-020-2780-0. https://www.nature.com/articles/s41586-020-2780-0

More about the KIT Climate and Environment Center: http://www.klima-umwelt.kit.edu/english

Press contact: Dr. Martin Heidelberger, Press Officer, Phone: +49 721 608-41169, Email: martin.heidelberger@kit.edu

Being "The Research University in the Helmholtz-Association," KIT creates and imparts knowledge for the society and the environment. It is the objective to make significant contributions to the global challenges in the fields of energy, mobility and information. For this, about 9,300 employees cooperate in a broad range of disciplines in natural sciences, engineering sciences, economics, and the humanities and social sciences. KIT prepares its 24,400 students for responsible tasks in society, industry, and science by offering research-based study programs. Innovation efforts at KIT build a bridge between important scientific findings and their application for the benefit of society, economic prosperity, and the preservation of our natural basis of life. KIT is one of the German universities of excellence.

This press release is available on the internet at http://www.kit.edu.

 

NUS study reveals severe air pollution drives food delivery consumption and plastic waste

Poor outdoor air is a strong push factor in consumers' use of food delivery services in China

NATIONAL UNIVERSITY OF SINGAPORE

Research News

 

When the air outside is bad, office workers are more likely to order food delivery than go out for lunch, which in turn increases plastic waste from food packaging, according to a study by researchers from the National University of Singapore (NUS).

Associate Professor Alberto Salvo from the Department of Economics at the NUS Faculty of Arts and Social Sciences and an author of the study, said, "Plastic waste is a growing global environmental concern. While we see more research on the impact plastic pollution is having on the natural environment, there has been less work trying to understand the human behaviour that drives plastic pollution. This is where our study seeks to contribute - finding a strong causal link between air pollution and plastic waste through the demand for food delivery. Air quality in the urban developing world is routinely poor and in the past decade, the food delivery industry has been growing sharply. The evidence we collected shows a lot of single-use plastic in delivered meals, from containers to carrier bags."

The results of the study were published in the journal Nature Human Behaviour.

Air pollution drives demand for food delivery services

The NUS team, including Assoc Prof Liu Haoming and Assoc Prof Chu Junhong, focused their study on China, which is among the world's largest users of online food delivery platforms, with 350 million registered users. An estimated 65 million meal containers are discarded each day across China, with office workers contributing over one-half of demand.

The study surveyed the lunch choices of 251 office workers repeatedly over time (each worker for 11 workdays) in three often smog-filled Chinese cities - Beijing, Shenyang and Shijiazhuang - between January and June 2018. To complement the office-worker survey, the researchers also accessed the 2016 Beijing order book of an online food delivery platform, which broadly represented all market segments served by the food delivery industry - collecting observational data on 3.5 million food delivery orders from about 350,000 users.

Data from the survey and order book were then compared with PM2.5 measurements (fine particles less than 2.5 micrometres in diameter) during lunchtime periods from the air-monitoring network in all three cities. It was observed that PM2.5 levels during these periods were often well above the 24-hour US National Ambient Air Quality Standard of 35 μg/m³, making pollution highly visible. The researchers were careful to control for confounding factors such as economic activity.

Both data sources indicated a strong link between PM2.5 (haze) pollution and food delivery consumption. Correcting for weather and seasonal influences, the firm's order book revealed that a 100 μg/m³ increase in PM2.5 raised food delivery consumption by 7.2 per cent. The impact of a 100 μg/m³ PM2.5 shift on office workers' propensity to order delivery was six times larger, at 43 per cent.

Assoc Prof Chu from the Department of Marketing at NUS Business School elaborated, "Faced with smog or haze outside, a typical office worker at lunchtime can avoid exposure only by ordering food to be delivered to his or her doorstep. A broader base of consumers has more alternatives to avoiding the outdoor environment on a polluted day, for example, by using a home kitchen when at home. This explains why the impact of air pollution on food delivery is smaller in the firm's order book study than what we observed among workers, particularly those without access to a canteen in their office building. Nevertheless, we find the impact to be economically large also among the broader population served by the food delivery platform that we examined."

Air pollution control brings plastic waste co-benefits

Over 3,000 photos of meals were submitted by office workers, enabling the NUS team to quantify how much disposable plastic varies across different lunch choices, in particular, meals eaten at the restaurant versus those delivered to the office. The researchers estimated that a 100 μg/m³ PM2.5 increase raised a meal's disposable plastic use by 10 grams on average - equivalent to about one-third the mass of a plastic container. Photographs that were published as part of the study indicated that the average delivered meal used 2.8 single-use plastic items and an estimated 54 grams of plastic. The average dine-in meal used an estimated 6.6 grams of plastic, such as in chopstick sleeves or bottles.

Based on the order book, the researchers also estimated that on a given day, if all of China were exposed to a 100 μg/m³ PM2.5 increase in dose as is routinely observed in Beijing, 2.5 million more meals would be delivered, requiring an additional 2.5 million plastic bags and 2.5 million plastic containers.

Assoc Prof Liu from the Department of Economics said, "Our findings probably apply to other typically polluted developing-nation cities, such as in Bangladesh, India, Indonesia and Vietnam. Waste management practices vary widely, with wind blowing plastic debris away from uncovered landfills or plastic being discarded into rivers and from there into the ocean. So, with eight million tonnes of plastic estimated to enter the seas each year, our study speaks to a wider issue. Individuals protect themselves from - and show their distaste for - air pollution by ordering food delivery which often comes in plastic packaging. It is evident from our study that air pollution control can reduce plastic waste."

Moving forward, the researchers will continue working on behavioural feedback by which pollution begets pollution: in particular, to defend themselves from environmental pollution, humans use more natural resources and pollute more. As a recent example, the researchers note how concern over exposure to COVID-19 has led to booming demand for home-delivered meals which are predominantly packaged in plastic. They hope that their work will add to the voices calling for more environmentally friendly packaging and improved waste management.

###

 

Cheaters don't always win: species that work together do better

Extinction may be prevented by diverse communities of mutually beneficial species

SYRACUSE UNIVERSITY

Research News

 

IMAGE: POSTDOCTORAL RESEARCHER MAYRA VIDAL WITH A TRAY CONTAINING A HARVESTED COMMUNITY OF YEAST. view more 

CREDIT: SYRACUSE UNIVERSITY

The sign of a healthy personal relationship is one that is equally mutual - where you get out just as much as you put in. Nature has its own version of a healthy relationship. Known as mutualisms, they are interactions between species that are mutually beneficial for each species. One example is the interaction between plants and pollinators, where your apple trees are pollinated and the honeybee gets nectar as a food reward. But what makes these mutualisms persist in nature? If rewards like nectar are offered freely, does this make mutualisms more susceptible to other organisms that take those rewards without providing a service in return?

A team of researchers from the College of Arts and Sciences at Syracuse University, including co-principal investigators Kari Segraves, professor of biology, and David Althoff, associate professor of biology, along with postdoctoral researcher Mayra Vidal, former research assistant professor David Rivers, and Sheng Wang '20 Ph.D., recently researched that question and the results have been published in this month's edition of the prestigious journal Science.

They investigated the abilities of simple versus diverse communities of mutualists, comparing how each deal with cheaters. Cheaters are species that steal the benefits of the mutualism without providing anything in return. An example of one of nature's cheaters are nectar robbers. Nectar-robbing bees chew through the side of flowers to feed on nectar without coming into contact with the flower parts that would result in pollination.

The research team wanted to test if having multiple mutualists with similar roles allows the community as a whole to persist when cheaters take away the mutualists' resources. The idea was to examine whether having more species involved in a mutualism, such as many pollinator species interacting with many different plant species, made the mutualism less susceptible to the negative effects of cheaters. They also wanted to analyze whether increasing the number of mutualist species allowed all the mutualists to persist or if competition would whittle down the number of mutualists species over time. In essence, the team wanted to understand the forces governing large networks of mutualists that occur in nature.

A&S researchers tested their ideas by producing mutualisms in the lab using yeast strains that function as mutualistic species. These strains were genetically engineered to trade essential food resources. Each strain produced a food resource to exchange with a mutualist partner. They engineered four species of each type of mutualist as well as two cheater strains that were unable to make food resources.

The researchers assembled communities of yeast that differed both in the number of species and the presence of cheaters. They found that communities with higher numbers of mutualist species were better able to withstand the negative effects of cheaters because there were multiple species of mutualists performing the same task. If one species was lost from the community due to competing with a cheater, there were other species around to perform the task, showing that the presence of more species in a community can lessen the negative effects of cheaters.

"It's similar to thinking about a plant that has many pollinator species," says Segraves. "If one pollinator species is lost, there are other pollinator species around to pollinate. If a plant only has one species of pollinator that goes extinct, the mutualism breaks down and might cause extinction of the plant."

Their results highlight the importance of having multiple mutualist species that provide similar resources or services, essentially creating a backup in case one species goes extinct. Segraves compares this phenomenon to the relationship between retailers and consumers. Communities typically have multiple banks, grocery stores, restaurants and hospitals to ensure that there are always goods and services available should something happen to one company or facility, or, as with COVID today, grocery stores now have multiple suppliers to fend off shortages.

Segraves says future research will explore the possibility of a mutualist species becoming a cheater. The group is testing if mutualists that perform the same function might set up an environment that allows one of those mutualist species to become a cheater since there are other mutualists around that can fill that role. They predict that the mutualist species that is experiencing the most competition from the other mutualists will be the species that switches to cheating. They also hope to determine how the mutualists and cheaters evolved over time to provide a deeper understanding of the actual changes that led to differing outcomes in the communities.

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The team's research was funded by a $710,000, three-year grant from the National Science Foundation.

 

Tiny beetles a bellwether of ecological disruption by climate change

UNIVERSITY OF COLORADO AT BOULDER

Research News

 

IMAGE: FLOUR BEETLES AND THEIR REFLECTIONS EXPLORE AND FEED ON FLOUR WITHIN A CONTROLLED LABORATORY ENVIRONMENT. view more 

CREDIT: BRETT MELBOURNE

As species across the world adjust where they live in response to climate change, they will come into competition with other species that could hamper their ability to keep up with the pace of this change, according to new University of Colorado Boulder-led research.

The new findings, published this month in the Proceedings of the National Academy of Sciences, confirms previous models showing that competition between species slows their expansion into new territories over multiple generations.

"The experiment shows how interspecies competition can put certain species at greater risk of extinction," said Geoffrey Legault, lead author of the study, who conducted the research while earning his doctoral degree in ecology and evolutionary biology at CU Boulder. "It has enabled us to improve the ecological models, and that helps us to make better predictions about nature."

The researchers found that competition between species sets the boundary where species expand their ranges, providing support for including interspecies competition in ecological models and studies that monitor, forecast or manage these changes in the natural world.

To achieve this new finding, the researchers used two species of a small, but resilient insect: the flour beetle.

Flour beetles have been studied since the early 1900s and are a model organism in ecology. In the same way that fruit flies are used as a model organism for studying genetics, flour beetles can represent the fundamental ecology of most organisms and their responses in the lab can be applied to larger ecological trends and patterns in the natural world.

In nature, these tiny creatures live on the ground in the leaf litter and in the bark of trees. While inconspicuous to us, they are common across the world.

In the lab, the researchers lined up a series of 1.5 inch-long plexiglass boxes joined by holes, which they could open and close like fences. The two species of flour beetles were born into opposite ends of this lineup, then observed as their populations expanded across the landscape and competed with each other.

"It's a microcosm of the larger natural world that allows you to focus in on the core processes of birth, death and movement," said Brett Melbourne, senior author on the study and associate professor of ecology and evolutionary biology.

Product pest and model organism

Upon entering Melbourne's laboratory, you might think you are in a bakery--not a space where scientific experiments are conducted. There is a dusting of flour everywhere and much of the equipment is more what you'd find in a bakery than a lab.

"We even sift the flour like you're supposed to when you're baking something," said Legault, currently a postdoctoral fellow at the University of British Columbia.

Flour is both the flour beetles' habitat and their food source--but it's also a high-demand human food product. The beetles are considered a major stored product pest, as they can get into not only your cupboards, but grain silos and flour mills. As a result, many studies about these insects focus on exterminating them.

But for the researchers, these food pests are perfect for conducting tightly controlled experiments. As the beetles have a short life cycle, observing their populations across many generations can be done within a year.

Yet the work is still intensive. In the year of the experiment, 24 CU Boulder undergraduates assisted Legault and Melbourne in counting more than a million beetles.

Climate change and changing habitats

For Melbourne, this research is especially critical in relationship to climate change.

"One way that species are experiencing climate change is that their habitat is moving: It's either going up mountain sides or it's moving toward the poles," said Melbourne.

In many parts of the world, the pace at which habitats are moving in these northern and upward directions across the globe is more than a kilometer per year, according to Melbourne. That is really fast, especially for species with limited ability to change where they live.

Predictions on how well a species will survive due to climate change moving their habitat often focus on single, individual species. But as many species migrate to new areas, they will encounter established species that already live there. Because the two species may rely on the same food sources or other resources, the survival of both is threatened.

"These kinds of species interactions could be super important for the long-term persistence or extinction of species in response to moving habitats," Melbourne said.

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Additional authors on this paper include Matthew Bitters in the Department of Ecology and Evolutionary Biology at CU Boulder; and Alan Hastings of the University of California and Santa Fe Institute.

 

Russian scientists suggested a transfer to safe nuclear energy

FAR EASTERN FEDERAL UNIVERSITY

Research News

 

Scientists from Far Eastern Federal University (FEFU), Ozersk Technological Institute, and the Russian Academy of Sciences have improved a processing technology of a monazite concentrate which is a mineral raw material employed as a source of rare earth elements and thorium. The latter, in turn, is a part of the thorium-uranium fuel cycle that is more eco-friendly compared to the one based on uranium and plutonium. A related article appears in Energies.

A team of scientists from FEFU and Ozersk Technological Institute (a branch of the National Research Nuclear University MEPhI) have optimized the technology of alkaline extraction of thorium from its main source, i.e. monazite concentrate stored at Uralmonazite State Enterprise (Krasnoufimsk, Sverdlovsk Region). The raw material contained 50% to 68% of REEs and 10% to 28% of thorium oxide.

The technology includes grinding and alkaline opening of the mineral raw material, turning target components into a solution, followed by extraction separation and purification of uranium, thorium, and REEs. The new method provided for the extraction of up to 90% of thorium and uranium and 100% of rare earth elements.

"Unlike uranium mineral products, the mineral commodities of thorium are found in abundance both in the Russian Federation and all over the world. A shift to the thorium-uranium cycle would secure the environmentally friendly development of the nuclear industry because this technology does not lead to the accumulation of nuclear waste. Moreover, as it claimed in scientific papers, with thorium-based fuel elements adoption, the nuclear core can be reduced by 2 to 3 times with no losses in the energy output. Also, according to this scenario, the reactor can be operated continuously for an estimated 50 years without fuel reloading", said Prof. Ivan Tananaev, the author of the work, and the Head of the School of Natural Sciences at FEFU.

According to the scientist, moving on to the thorium-uranium fuel cycle could become a medium-term matter in Russia due to the National nuclear energy development program which is considered a priority area for the modernization of the country's economy. Until recently, the nuclear industry in Russia has been working on the basis of the uranium-plutonium cycle that was developed in the middle of the XX century and guaranteed nuclear deterrence. As Prof. Tananaev believes, the utilization of an alternative thorium-uranium cycle has a number of indirect benefits. For example, the production of thorium leads to the development of the REE industry. Furthermore, secondary products of monazite processing are phosphate fertilizers that can be exploited in agro technologies.

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The work was carried out under the Cooperation Agreement between FEFU and the National Research Nuclear University MEPhI (dd. 24.11.2014), and supported by grant No. 18-29-24138 of the Russian Foundation for Basic Research, principal investigator is Prof. Ivan G. Tananaev, Head of the School of Natural Sciences at FEFU, Deputy Head of Research at OTI.

 

Save it or spend it? Advertising decisions amid consumer word-of-mouth

New research finds it depends on what consumers are saying and what the ads are doing

INSTITUTE FOR OPERATIONS RESEARCH AND THE MANAGEMENT SCIENCES

Research News

 

INFORMS Journal Marketing Science New Study Key Takeaways:

"Word-of-mouth" is not always a substitute for advertising.

When consumers learn about products from other consumers, businesses should increase advertising spending to prove their product is high-quality.

When all consumers share their experiences, a high-quality business may be better served by reducing its advertising spending.

As more negative experiences are shared, it can be optimal for a high-quality business to spend more on advertising.

CATONSVILLE, MD, October 19, 2020 - Most people have seen or heard from a friend, neighbor or family member about a product or service they've used and how their experience was. It's called observational learning or word-of-mouth. These communications don't provide an unbiased assessment of true quality. Given this, businesses are faced with the difficult decision of determining when and how to spend their ad dollars. New research in the INFORMS journal Marketing Science finds when consumers learn about products/services from other consumers, a business may actually want to spend more money to credibly signal its quality.

The study, "When Consumers Learn, Money Burns: Signaling Quality Via Advertising with Observational Learning and Word of Mouth," details that word of mouth and advertising are not the same. Word of mouth is believed to be "free" advertising; but this may not always be the case. In fact, the opposite may be true when the role of advertising is to credibly signal product quality to consumers.

Word-of-mouth interactions may involve underreporting (not everyone shares experiences), positive reporting (when positive experiences are communicated more widely than negative ones) or negative reporting (when negative experiences are communicated more widely than positive ones).

"While both word of mouth and advertising can provide information regarding quality to consumers, one would suspect a high-quality business should have to spend less on advertising as it would benefit from word of mouth," said Yogesh Joshi, a professor at the University of Maryland. "However, this research shows that word of mouth, rather than softening the need for spending on advertising, may require a high-quality business to allocate more resources to these quality signaling efforts."

Joshi and his co-author Andres Musalem of the University of Chile and Instituto Sistemas Complejos de Ingeniería (ISCI) say the benefits for a low-quality business force a high-quality one to spend more on advertising, to prove their worth and that their quality is better than the low-quality business that's getting traction from word of mouth.

"When all consumers share their experiences, a high-quality business may be better served by reducing its investment in advertising, and in certain cases by a lot," said Joshi. "Further, as more negative experiences are shared, it can be optimal for a high-quality business to spend more on advertising because as the sharing of negative experiences increases, some late consumers who would have otherwise been exposed to no experiences are now exposed to complaints."

When quality differences across types are not too strong, and consumers share more complaints, the researchers say a high-quality business may need to allocate more resources to its quality-signaling advertising efforts.

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About INFORMS and Marketing Science

Marketing Science is a premier peer-reviewed scholarly journal focused on research using quantitative approaches to study all aspects of the interface between consumers and firms. It is published by INFORMS, the leading international association for operations research and analytics professionals. More information is available at http://www.informs.org or @informs.

Contact:

Ashley Smith
443-757-3578
asmith@informs.org