Posidonia marine seagrass can catch and remove plastics from the sea

A trap for plastics in coastal areas

UNIVERSITY OF BARCELONA

Research News

 

IMAGE: IN THE GRASSLANDS, THE PLASTICS ARE INCORPORATED TO AGGLOMERATES OF NATURAL FIBER WITH A BALL SHAPE (AEGAGROPILA OR POSIDONIA NEPTUNE BALLS). view more 

CREDIT: UNIVERSITY OF BARCELONA

Posidonia oceanica seagrass -an endemic marine phanerogam with an important ecological role in the marine environment- can take and remove plastic materials that have been left at the sea, according to a study published in the journal Scientific Reports. The article's first author is the tenure-track 2 lecturer Anna Sànchez-Vidal, from the Research Group on Marine Geosciences of the Faculty of Earth Sciences of the University of Barcelona (UB).

The study describes for the first time the outstanding role of the Posidonia as a filter and trap for plastics in the coastal areas, and it is pioneer in the description of a natural mechanism to take and remove these materials from the sea. Other authors of the study are the experts Miquel Canals, William P. de Haan and Marta Veny, from the Research Group on Marine Geosciences of the UB, and Javier Romero, from the Faculty of Biology and the Biodiversity Research Institute (IRBio) of the UB.

A trap for plastics in coastal areas

The Posidonia oceanica makes dense prairies that make a habitat with a great ecological value (nutrition, shelter, reproduction, etc.) for marine biodiversity. As part of the study, the team analysed the trapping and extraction of plastic in great seagrasses of the Posidonia in the coasts of Majorca. "Everything suggests that plastics are trapped in the Posidonia seagrass. In the grasslands, the plastics are incorporated to agglomerates of natural fiber with a ball shape -aegagropila or Posidonia Neptune balls- which are expulsed from the marine environment during storms", notes Anna Sànchez-Vidal, member of the Department of Ocean and Earth Dynamics of the UB.

"According to the analyses -she continues- the trapped microplastics in the prairies of the Posidonia oceanica are mainly filaments, fibers and fragments of polymers which are denser than the sea water such as polyethylene terephthalate (PET).

How are Posidonia Neptune balls made?

This marine phanerogam has a vegetative structure made by a modified stem with a rhizome shape from which the roots and leaves appear. When the leaves fall, its bases (pods) are added to rhizomes and give them a feather-like appearance. "As a result of the mechanical erosion in the marine environment, those pods under the seafloors are progressively releasing lignocellulosic fibres which are slowly added and intertwined until they make agglomerates in a ball-shape, known as aegagropilae. Aegagropilae are expulsed from prairies during periods of strong waves and a certain part ends up in the beaches", says Professor Javier Romero, from the Department of Evolutionary Biology, Ecology and Environmental Sciences and the Biodiversity Research Institute (IRBio) of the UB.

Posidonia aegagropilae are expelled from the prairies during periods of strong waves and a part ends up piled in the beaches. Although there are no studies that quantify the amount of aegagropilae expelled from the marine environment, it is estimated that about 1,470 plastics are taken per kilogram of plant fibre, amounts which are significantly higher than those captured through leaves or sand. As researcher Anna Sànchez-Vidal says, "we cannot completely know the magnitude of this plastic export to the land. However, first estimations reveal that Posidonia balls could catch up to 867 million plastics per year".

CAPTION

This natural mechanism could trap about 867 million plastic per year in coastal areas.

Plastic-free oceans: everyone's responsibility

The polluting footprint of plastics that come from human activity is a serious environmental problem affecting coastal and ocean ecosystems worldwide. Since plastics were created massively in the 20th century fifties, these materials have been left and accumulated at the sea -seafloors act as a sink for microplastics-- and are transported by ocean currents, wind and waves. "The plastics we find floating in the sea are only a small percentage of everything we have thrown onto the marine environment", warns Anna Sànchez-Vidal.

The paper published in the journal Scientific Reports has been carried out within the frame of the subject of the EHEA bachelor's degree final project of the degree in Marine Sciences of the Faculty of Earth Sciences, and counted on the support from the Scientific and Technological Centers of the UB (CCiTUB). The new ecosystemic service of the Posidonia described in the article has a significant value in a marine area such as the Mediterranean -with high quantities of floating plastic and in the seafloors-- and with Posidonia seagrass that can occupy large areas up to forty meters deep.

"This is why we need to protect and preserve these vulnerable ecosystems. However, the best environmental protection strategy to keep oceans free of plastic is to reduce landfills, an action that requires to limit its use by the population", conclude the experts.

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Teeth pendants speak of the elk's prominent status in the Stone Age

UNIVERSITY OF HELSINKI

Research News

 

IMAGE: A TOTAL OF 90 ELK TEETH WERE PLACED NEXT TO THE HIPS AND THIGHS OF THE BODY IN GRAVE 127, POSSIBLY ATTACHED TO A GARMENT RESEMBLING AN APRON. THERE WERE... view more 

CREDIT: DRAWING BY TOM BJORKLUND

Roughly 8,200 years ago, the island of Yuzhniy Oleniy Ostrov in Lake Onega in the Republic of Karelia, Russia, housed a large burial ground where men, women and children of varying ages were buried. Many of the graves contain an abundance of objects and red ochre, signifying the wish to ensure the comfort of the buried also after death. Pendants made of elk incisors were apparently attached to clothing and accessories, such as dresses, coats, cloaks, headdresses and belts. Although no clothing material has been preserved, the location of the elk teeth sheds light on the possible type of these outfits.

A people of grooved elk tooth pendants

A study headed by archaeologist Kristiina Mannermaa, University of Helsinki, aimed to determine who the people buried in outfits decorated with elk tooth ornaments were, and what the pendants meant to them. The study analysed the manufacturing technique of a total of more than 4,000 tooth ornaments, or the way in which the teeth had been processed for attachment or suspension. The results were surprising, as practically all of the teeth had been processed identically by making one or more small grooves at the tip of the root, which made tying the pendants easier. Only in two instances had a small hole been made in the tooth for threading, both of which were found in the grave of the same woman. The tooth pendants found in graves located in the Baltic area and Scandinavia from the same period as the Yuzhniy Oleniy Ostrov graves are almost exclusively perforated. Perforation is the surest way of fastening the pendant, but making holes in the narrow tip of a tooth is more laborious than grooving.

Archaeological and ethnographic research has shown that humans have been using decorations almost always and everywhere in the world, for several different purposes. To many indigenous peoples in Eurasia, including the Sámi communities, decorations have been and still are an important way of describing a person's identity and origin. They are not only aesthetic details, but also connected to intercommunity communication and the strengthening of intracommunity uniformity. External elements such as ornaments can also influence the names which neighbouring groups use to refer to a community. In fact, Kristiina Mannermaa calls the people found in the burial site the people of grooved elk tooth pendants.

"Even though there are pendants made of beaver and bear teeth in the graves, the share of elk teeth in them is overwhelming," Mannermaa says.

Typically, only one or at the most a couple of different groove types were prevalent in individual graves. This indicates that the pendants found in a specific grave or cluster were the result of routine serial production of sorts carried out in a fairly short period of time. The most common groove types were firm as well as quick and easy to make.

"Interestingly, the grooves were not always made on the broadest side of the tooth, which would be the easiest option. In many graves, the grooves are on the thin side of the tooth where the unstable position of the tooth makes them harder to do. The artisan may have resorted to this method in order to tie them in a specific position," researcher Riitta Rainio notes.

The highest number of elk teeth were found in the graves of young adult women and men, the lowest in those of children and elderly people. In other words, elk tooth ornaments were in one way or another linked to age, possibly specifically to the peak reproductive years.

Elk was the most important animal in the ideology and beliefs of the prehistorical hunter-gatherers of the Eurasian forest zone, and their limited availability made elk teeth a valuable material to ancient hunters. Elks were not brought down very often, and not all members of the community contributed to hunting. It may be that a single individual was given all of the incisors of a caught elk. Elks have a total of eight incisors, six permanent ones in the lower jaw and two permanent canines in the shape of incisors. At times, corresponding deciduous teeth were also processed into ornaments. The largest ornaments required the teeth of at least 8 to 18 elks.

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In addition to Mannermaa, Riitta Rainio from the University of Helsinki as well as Evgeniy Yurievich Girya and Dmitriy Gerasimov from Peter the Great's Museum of Anthropology and Ethnography contributed to the study.

Greenland melting likely increased by bacteria in sediment

Microbes in meltwater stream sediment may help boost island's contribution to sea-level rise

RUTGERS UNIVERSITY

Research News

 

IMAGE: A SUPRAGLACIAL STREAM AND SEDIMENT FLOODPLAIN IN SOUTHWEST GREENLAND. view more 

CREDIT: SASHA LEIDMAN

Bacteria are likely triggering greater melting on the Greenland ice sheet, possibly increasing the island's contribution to sea-level rise, according to Rutgers scientists.

That's because the microbes cause sunlight-absorbing sediment to clump together and accumulate in the meltwater streams, according to a Rutgers-led study - the first of its kind - in the journal Geophysical Research Letters. The findings can be incorporated in climate models, leading to more accurate predictions of melting, scientists say.

"These streams can be seen all over Greenland and they have a brilliant blue color, which leads to further melting since they absorb more sunlight than the surrounding ice," said lead author Sasha Leidman, a graduate student in the lab of co-author Asa K. Rennermalm, an associate professor in the Department of Geography in the School of Arts and Sciences at Rutgers University-New Brunswick. "This is exacerbated as dark sediment accumulates in these streams, absorbing even more sunlight and causing more melting that may increase sea-level rise."

The Greenland ice sheet covers about 656,000 square miles - most of the island and three times the size of Texas, according to the National Snow & Ice Data Center. The global sea level would rise an estimated 20 feet if the thick ice sheet melted.

With climate change, sea-level rise and coastal storms threaten low-lying islands, cities and lands around the world.

YouTube video: Drone flight over a supraglacial stream in Greenland

Most scientists ignore sediment in glacial streams that form on top of the Greenland ice sheet as meltwater flows to the ocean, but the Rutgers-led team wanted to find out why they accumulated so much sediment. In 2017, scientists flew drones over an approximately 425-foot-long stream in southwest Greenland, took measurements and collected sediment samples. They found that sediment covers up to a quarter of the stream bottom, far more than the estimated 1.2 percent that would exist if organic matter and cyanobacteria did not cause sediment granules to clump together. They also showed that streams have more sediment than predicted by hydrological models.

"We found that the only way for sediment to accumulate in these streams was if bacteria grew in the sediment, causing it to clump into balls 91 times their original size," Leidman said. "If bacteria didn't grow in the sediment, all the sediment would be washed away and these streams would absorb significantly less sunlight. This sediment aggregation process has been going on for longer than human history."

The solar energy absorbed by streams likely depends on the health and longevity of the bacteria, and further warming in Greenland may lead to greater sediment deposits in glacial streams, the study says.

"Decreases in cloud cover and increases in temperature in Greenland are likely causing these bacteria to grow more extensively, causing more sediment-driven melting," Leidman said. "With climate change causing more of the ice sheet to be covered by streams, this feedback may lead to an increase in Greenland's contribution to sea-level rise. By incorporating this process into climate models, we'll be able to more accurately predict how much melting will occur, with the caveat that it is uncertain how much more melting will take place compared with what climate models predict. It will likely not be negligible."

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Rutgers co-authors include graduate student Rohi Muthyala and School of Engineering Professor Qizhong (George) Guo. A scientist at the University of Colorado Boulder contributed to the study.

The richer you are, the more likely you'll social distance, study finds

JOHNS HOPKINS UNIVERSITY

 NEWS RELEASE 14-JAN-2021

Research News

The higher a person's income, the more likely they were to protect themselves at the early stages of the Covid-19 pandemic in the United States, Johns Hopkins University economists find.

When it comes to adopting behaviors including social distancing and mask wearing, the team detected a striking link to their financial well-being. People who made around $230,000 a year were as much as 54% more likely to increase these types of self-protective behaviors compared to people making about $13,000.

"We need to understand these differences because we can wring our hands, and we can blame and shame, but in a way it doesn't matter," said Nick Papageorge, the Broadus Mitchell Associate Professor of Economics. "Policymakers just need to recognize who is going to socially distance, for how long, why and under what circumstances to give us accurate predictions of how the disease will spread and help us establish policies that will be useful."

The findings, that could contribute to more accurate predictions of how the disease will spread, appear in the latest Journal of Population Economics.

As part of a six-country survey, 1,000 people in the United States, from Texas, Florida, California and New York, were asked a series of questions in April 2020 to determine if and how their behavior had changed as Covid-19 cases were beginning to spike across the country. The resulting data includes information on income, gender and race along with unique variables relevant to the pandemic, such as work arrangements and housing quality.

The team, which included economics graduate student Matthew Zahn, found that while almost everyone changed their behavior in some way to try to stay safe, people making the most money made the most changes. The highest earners were 13% more likely to change their behaviors, 32% more likely to increase social distancing and 30% more likely to increase hand washing and mask wearing.

But the team found it was also much easier for people with more money to take extra safety measures.

Higher-income individuals were more likely to report being able to work from home and more likely to have transitioned to telework instead of losing their job. The researchers found the ability to telework emerged as a huge predictor of whether someone would social distance. Compared to somebody who continued to work, people able to telework were 24% more likely to social distance.

"The whole messaging of this pandemic is you're stuck at home teleworking, that must be really tough so here are some recipes for sourdough starter, and here's what you should catch up on Netflix," Papageorge said. "But what about the people who aren't teleworking? What are they going to do?"

The team found lower-income respondents faced increased chances of job and income losses due to the pandemic and limited access to remote work. They were also more likely to live in homes with no access to the outdoors - access to outdoor space was a very strong predictor of social distancing, the researchers found. People with access to open air at home were 20% more likely to social distance.

All of these burdens ensured those earning the least would have a harder time adopting social-distancing behaviors, which could have prolonged the pandemic, the team found. Social distancing was simply more practical, comfortable and feasible for people with more income.

"It's not shocking that if you don't live in a comfortable house you're going to be leaving your house more often. But the point we want to push is that if I'm a policy maker maybe I really need to think about opening city parks in a dense neighborhood during a pandemic. Maybe that's something that's worth the risk. This is why we want to understand these details - they can eventually suggest policies," Papageorge said.

The data showed that women were 23% more likely than men to social distance. Surprisingly, the researchers did not find any meaningful patterns between pre-existing health conditions and people's self-protective actions.

The team is now expanding this research with even more extensive surveys that look into how events such as the Black Lives Matter protests affected behavior during the pandemic, the pandemic's possible effects on addictive behaviors and, more broadly, how to build tools to better understand the unequal burdens the pandemic.

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Authors also included: Michele Belot of Cornell University; Eline van den Broek-Altenburg of University of Vermont; Syngjoo Choi of Seoul National University; Julian C. Jamison of University of Exeter; and Egon Tripodi of University of Essex.

This work was supported by funding from the Creative-Pioneering Researchers Program at Seoul National University and the European University In

New classification marks paradigm shift in how conservationists tackle climate change

WILDLIFE CONSERVATION SOCIETY

Research News

 

IMAGE: TRANSFORMATION-ORIENTED PROJECTS INVOLVED TRANSLOCATION OF TREES OR OTHER PLANTS, COMMONLY IN FOREST ECOSYSTEMS. view more 

CREDIT: NICOLE MATSON

NEW YORK (January 14) -- A new study co-authored by researchers from the Wildlife Conservation Society's (WCS) Global Conservation Program and the University of British Columbia (UBC) Faculty of Forestry introduces a classification called Resistance-Resilience-Transformation (RRT) that enables the assessment of whether and to what extent a management shift toward transformative action is occurring in conservation. The team applied this classification to 104 climate adaptation projects funded by the WCS Climate Adaptation Fund over the past decade and found differential responses toward transformation over time and across ecosystems, with more transformative actions applied in forested ecosystems.

The RRT classification addresses a continuum from actively resisting changes - in order to maintain current or historical conditions--through accelerating ecological transitions through approaches such as translocating species to new areas. Results show a shift from more resistance-type actions to transformative ones in recent years. Most transformation-oriented projects involved translocation of trees or other plants, commonly in forest ecosystems, with exceptions including, for example, translocating seabird species to habitat where they may be more likely to survive. Other ecosystems with more transformative projects occurred in coastal aquatic and urban/suburban ecosystems.

Unprecedented environmental changes such as increased frequency and severity of heatwaves, droughts, storms, heavy rainfalls, and wildfires, have degraded ecosystems, disturbed the economy, and led to the loss of lives and livelihoods. Conventional conservation strategies may be ineffective in dealing with changing environmental conditions: wildfires could decimate protected old-growth forests and endangered species, and coastal conservation easements could become inundated by rising seas. Novel conservation actions aimed specifically at helping ecosystems adapt to the mounting impacts of climate change contrast with approaches that aim to maintain current or historical conditions. Transformative actions, such as species translocation, were once more controversial than they are today; they are now increasingly highlighted as necessary components of conservation in an effort to implement projects that are more robust to future climates. However, few studies have systematically examined on-the-ground conservation adaptation projects to assess the extent to which such transformational adaptation actions are being implemented, through what approaches, and in what ecosystems.

This study, published in Nature Communications Biology, assessed projects implemented within the United States but the authors see broader applications. "Our classification could be applied to a suite of conservation projects across the world to determine if a global shift in practice is occurring," said co-author Lauren Oakes, a Conservation Scientist at WCS and Adjunct Professor at Stanford University. Guillaume Peterson St-Laurent, the lead author and a postdoc at the University of British Columbia, says the team is interested in creating an online platform for tracking projects assessed with the new classification around the globe. "We hope to be working with international teams in the not-so-distant future as we envision this new tool could be applied to many different ecological scenarios," says Peterson St-Laurent.

The interdisciplinary research team was supported by the Doris Duke Charitable Foundation, and the study was conducted in partnership with the IUCN Species Survival Commission's Climate Change Specialist Group.

Precautionary actions aimed at resistance or resilience--such as protecting intact ecosystems--are incredibly valuable in the suite of responses needed to address current and future climate change. But the authors suggest that degraded ecosystems or working landscapes may require more transformative actions and the public support to do so, in an effort to meet the shifting goals in a changing climate. This research provides evidence of a paradigm shift, as practitioners and funders move more in this critical direction.

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About the Wildlife Conservation Society

WCS saves wildlife and wild places worldwide through science, conservation action, education, and inspiring people to value nature. To achieve our mission, WCS, based at the Bronx Zoo, harnesses the power of its Global Conservation Program in nearly 60 nations and in all the world's oceans and its five wildlife parks in New York City, visited by 4 million people annually. WCS combines its expertise in the field, zoos, and aquarium to achieve its conservation mission. Visit: newsroom.wcs.org Follow: @WCSNewsroom. For more information: 347-840-1242.

About the Doris Duke Charitable Foundation (DDCF). The mission of the Doris Duke Charitable Foundation is to improve the quality of people's lives through grants supporting the performing arts, environmental conservation, medical research and child well-being, and through the preservation of the cultural and environmental legacy of Doris Duke's properties. The foundation's Environment Program seeks to enable communities to protect and manage wildlife habitat and create efficient built environments. An awareness of climate change as the greatest emerging threat to biodiversity--and the need to aggressively mitigate it without unnecessarily sacrificing wildlife habitat--shapes the Environment Program's grant-making priorities. In addition to funding researchers from the WCS Global Conservation Program, DDCF also funds the WCS Climate Adaption Fund. For more information, visit ddcf.org.

About the University of British Columbia's (UBC) Faculty of Forestry. UBC's Faculty of Forestry is a global leader in forestry education and research. What began in 1921, today embodies a comprehensive offering of undergraduate and graduate programs as well as world-renowned research and initiatives. Our programs and research draw from all forest science disciplines and model the broad spectrum of topics relating to forests' interplay between our environment and all those who live on our planet. For more information, visit forestry.ubc.ca/news/media-centre.

About the IUCN SSC Climate Change Specialist Group

The IUCN SSC Climate Change Specialist Group is a global network of scientists working at the research-policy-practice interface to strengthen nature conservation in a changing climate. With more than 60 members worldwide, we work at the forefront of climate change and biodiversity science to bridge knowledge gaps, build collaborations, and strengthen the community of practice around climate-focused conservation. Learn more at ccsg-iucn.com or follow us on Facebook (IUCN SSC Climate Change Specialist Group) or Twitter (@IUCN_CCSG).

Lack of managers keeps India's businesses small

YALE UNIVERSITY

Research News

 

In today's economy, American businesses often tap into professional management to grow, but most firms in India and other developing countries are family owned and often shun outside managers. A new study co-authored by Yale economist Michael Peters explores the effects that the absence of outside professional management has on India's businesses and the country's economy.

The study, published in the American Economic Review, uses a novel model to compare the relationship between the efficiency of outside managers and firm growth in the United States and India. It shows that the lack of managerial delegation factors significantly into why businesses in India tend to stay small and has wider implications on the country's economy, constraining innovation, economic growth, and per capita income.

"There's been growing evidence that managerial services might be the key missing input for many firms in poor countries," said Peters, associate professor of economics in Yale's Faculty of Arts and Sciences. "Our analysis confirms that the absence of managerial delegation is a significant factor in why successful Indian businesses fail to grow, which reduces the overall productivity of the country's economy."

By growing, companies generate employment, promote innovation, and contribute to a countries' economic productivity, the researchers say.

In developed countries, family-owned firms such as Walmart, Ford Motor Co., and the Lego Group, which all emerged from humble beginnings, grew into corporate behemoths, with hundreds of thousands of employees, by delegating key operations to outside managers. But businesses in developing countries rarely hire managers outside the owners' families, the researchers note.

Peters and his co-authors, Ufuk Akcigit of the University of Chicago and Harun Alp of the University of Pennsylvania, focused their analysis on this disparity between developed and developing countries' firm sizes. They created a quantitative model that centers the role of managerial delegation in firm growth. It incorporated plant-level data from the United States and India and was calibrated to recognize that business in India might face higher barriers to growth, such as having less access to start-up capital, than U.S. businesses.

In India, more than 9 out of 10 of manufacturing businesses have fewer than four employees, and those small firms account for more than half of total employment. In contrast, two-thirds of U.S. manufacturing employment is concentrated in establishments with at least 100 employees, and only one-third of firms have fewer than four employees, according to the study.

The researchers found that India's economy suffers from "a lack of selection" -- the process of creative destruction through which successful businesses expand while unproductive firms close or are swallowed up by competitors -- allowing unproductive businesses to survive because successful businesses do not expand. Their analysis showed that the low productivity of outside managers in India, which they estimate to be substantially lower than in the United States, is one cause of the lack of selection and has negative consequences for India's economy.

If Indian businesses used outside managers as efficiently as U.S. businesses, it would boost economic productivity in India and increase the country's per capita income by about 11%, according to the study.

The study found a strong complementary relationship between the quality of outside managers and other factors affecting firm growth, such as access to capital or credit. Increasing the efficiency of managerial delegation to U.S. standards would increase average firm size by 3%, the researchers said. In contrast, if U.S. businesses had to operate with management practices common in India, the country's average firm would shrink by about 15%. This disparity between the U.S. and India shows that the productivity of outside managers is not the only determinant of firm growth and that other forces prevent successful Indian businesses from expanding, Peters explained.

"The complementarity between the efficiency of delegating managerial tasks and other aspects affecting firm growth, such as access to credit, is one of our key results," said Peters, who is affiliated with Yale's Economic Growth Center. "For improvements to managerial quality to have a large effect, other factors hindering growth must be addressed. If you repair a punctured tire, you still can't drive if your other tires are flat."

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A link to the paper and a detailed summary of its findings is available on the Economic Growth Center's website.

Population density and virus strains will affect how regions can resume normal life

UNIVERSITY OF WISCONSIN-MADISON

Research News

 

MADISON, Wis. -- As a new, apparently more transmissible version of the virus that causes COVID-19 has appeared in several countries, new research finds that the transmissibility of viral strains and the population density of a region will play big roles in how vaccination campaigns can help towns and cities return to more normal activities.

The findings suggest that directing vaccines toward densely populated counties would help to interrupt transmission of the disease. Current vaccination distribution plans don't take density into account.

Tony Ives at the University of Wisconsin-Madison and Claudio Bozzuto of the independent data research company Wildlife Analysis GmbH studied the spread of COVID-19 in the U.S. at the start of the pandemic, before people changed their behavior to avoid the disease. This let them uncover factors that may affect the transmission of COVID-19 when masking and physical distancing start to wane and behavior once again resembles the pre-pandemic normal.

"We wanted to get at two things: the first was to try and understand what the dynamics were very early in the pandemic. If we need a vaccination program in place that lets people act normally, then we need to understand the state under those conditions," says Ives, a professor of integrative biology at UW-Madison. "The second was trying to get at a fairly small spatial scale of counties instead of states."

Parsing out county-by-county data from 39 states through May 23, 2020, Ives and Bozzuto found that the higher a county's population density, the more readily SARS-CoV-2, the virus responsible for COVID-19, spread from person to person. This county-level spread is ultimately quantified in the basic reproduction number of the virus, a measure of the average number of people an infected person goes on to infect.

The researchers also found compelling evidence that viral strain matters. Ives and Bozzuto saw that the regions hosting a greater proportion of strains containing a mutation called G614 experienced greater viral spread, a finding supported by other research showing that this strain could be transmitted more readily.

While the G614 mutant is unrelated to B.1.1.7, a strain first identified in the United Kingdom that appears to be spreading more easily right now, the new study reflects the importance that viral strain can play in a local area's overall disease spread.

"We found a clear pattern in the spread rate due to different strains," says Bozzuto. "Our approach was novel because we went directly to the community level to ask, 'Can we see any patterns in the data without making assumptions about individual behavior, including strain-related transmissibility and pathogenicity?'"

To track the rate of viral spread, Ives and Bozzuto worked with the number of people who died of COVID-19 last spring. When testing was limited at the beginning of the pandemic, deaths much more accurately tracked COVID-19 transmission. As long as a relatively constant proportion of infected people die from the disease, data on how deaths increase over time will be directly proportional to the overall rate of spread.

Population density predicted a considerable amount of the difference in the rate of viral spread from county to county during the time period the researchers studied. Counties with low or moderate density did not have high rates of infection spread, though lower transmission rates do not necessarily protect a region from eventually seeing high case counts.

Location explained an even greater fraction of the spread in the researchers' model. Regions within a few hundred miles of one another had similar transmission rates. This regional similarity might have been caused in part by similar public health responses in neighboring counties.

But Ives and Bozzuto also found evidence that regional differences in viral strains explained why neighboring counties looked similar. For example, the low proportion of G614 mutants in the Northwest and Southeast was associated with lower transmission rates.

The researchers investigated several other factors -- such as prevalence of obesity and diabetes, socioeconomic status, and political affiliation -- and found that none of them contributed significantly to the rate of spread of COVID-19 at the very start of the epidemic. Although these factors may affect how susceptible individuals and populations are to complications from the disease, they didn't appear to affect the transmission of the virus from person to person.

The new findings were published in the journal Communications Biology on Jan. 5. Ives and Bozzuto say their work can help public health officials decide where vaccines would do the most good.

"Vaccination programs should consider potential spread rate in different areas. The main driver that will be important is density," says Ives. "From an epidemiological perspective, we would argue that metropolitan areas should be targeted because the level of vaccination or acquired immunity has to be higher than in largely rural areas."

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This work was supported by NASA (grant 80NSSC20K0282).

--Eric Hamilton, (608) 263-1986, eshamilton@wisc.edu

CONTACT: Tony Ives, arives@wisc.edu; Claudio Bozzuto, bozzuto@wildlifeanalysis.ch

READ ON THE WEB: https://news.wisc.edu/population-density-and-virus-strains-will-affect-how-regions-can-resume-normal-life/

Discrimination may increase risk of anxiety disorders regardless of genetics, study finds

Findings, the first of their kind, could help drive public health policy on reducing impact of discrimination on mental health

TUFTS UNIVERSITY

MEDFORD/SOMERVILLE, Mass. (Jan. 14, 2021)-- Exposure to discrimination plays a significant role in the risk of developing anxiety and related disorders, even - in a first - after accounting for potential genetic risks, according to a multidisciplinary team of health researchers led by Tufts University and the Harvard T.H. Chan School of Public Health.

Researchers determined that even after controlling for genetic risk for anxiety, depression, and neuroticism, greater reports of discrimination experiences remained associated with higher scores of anxiety and related disorders. The findings, recently published in Proceedings of the National Academy of Sciences, suggest that discrimination is a risk factor for anxiety and related disorders rather than solely a result of common genetic liability.

The study authors included researchers from Stony Brook University, University of Minnesota, in addition to Harvard's School of Public Health and Tufts.

"The study results demonstrate that discriminatory experiences can potentially cause stress and mental health problems regardless of the genetic constitution of the individual," said Adolfo G. Cuevas, an assistant professor of community health and director of the Psychosocial Determinants of Health Lab at Tufts' School of Arts and Sciences, who is first author of the study. "From regular slights in public spaces to more significant incidents, such as being passed over for a promotion or a loan, these experiences can take a toll on your mental health."

Anxiety disorders, including generalized anxiety disorder, panic disorder or phobias, are the most common mental illness, affecting over 40 million people in the United States every year, according to the Anxiety and Depression Association of America. While exposure to discrimination has long been established as a risk factor in the development of these disorders, the relationship between discrimination and anxiety, when factoring in the role genetics play, has remained less clear.

To gain insight on the connection, the research team used data from a national probability sample of approximately 1,500 non-institutionalized, all English-speaking adults aged 25-74 and living in the mainland United States. Approximately 49 percent of the sample were women.

Three self-report scales were used to measure discrimination and other forms of social exclusion, including:
everyday discrimination, e.g. "being treated with less courtesy than other people" and "receiving poorer service than other people at restaurants or stores;"
major discrimination, e.g. "discouraged by a teacher or advisor from seeking higher education" and "being prevented from renting or buying a home in the neighborhood you wanted;" and
chronic job discrimination, e.g. "being unfairly given the jobs that no one else wanted to do" and "whether your supervisor or boss use ethnic, racial, or sexual slurs or jokes."

After accounting for increased genetic liability for anxiety, depression, neuroticism, and other potential genetic and sociodemographic factors, the researchers found a high degree of interdependence between discrimination and anxiety.

The team said the findings demonstrate that alleviating the impact of discrimination has the potential to improve mental health within the overall population. "Anxiety is one of the most significant issues in mental health today, and our study conclusions underscore the importance of reducing discrimination exposure and thereby improving the public's mental health overall," said the senior author of the study, Robert F. Krueger, Distinguished McKnight University Professor of Psychology at the University of Minnesota.

"These findings allow us to engage in conversations with political leaders, health officials, and community members to develop functional approaches to reduce exposure to discrimination and improve the mental health of all," David R. Williams, a study co-author and the Florence Sprague Norman and Laura Smart Norman Professor of Public Health at the Harvard T.H. Chan School of Public Health. Williams is also a professor in the department of African and African American Studies at Harvard.

The impact of anxiety disorders is significant. Symptoms are a common associated feature of depressive disorders and, generally, account for a substantial burden of morbidity and mortality as well as long-term work disability and absenteeism. For instance, anxiety disorders are associated with several chronic health conditions, including heart disease, hypertension, and diabetes.

The researchers identified key limitations of the study, including the use of a cohort of white-identifying respondents who were predominately of European ancestry. They noted while the effects of discrimination seem to be similar across racial/ethnic groups, racial/ethnic minorities experience more discrimination than their white counterparts, placing them at an increased risk for poor mental health. In addition, questions remain about the extent to which self-reported experiences of discrimination by whites are equivalent to those of more socially stigmatized groups.

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The study uses data from the MIDUS (the study of Midlife in the United States Biomarker) study, which is supported by the John D. and Catherine T. MacArthur Foundation Research Network, National Institute on Aging and other funders. The development of the manuscript was partially supported by Cancer Disparities Research Network/Geographic Management Program and other supporters. See the paper for detailed information on all funders.

Cuevas, A.G., Mann, F.D., Williams, D.R., and Krueger, R. F. (2020), Discrimination and anxiety: Using multiple polygenic scores to control for genetic liability," PNAS. DOI: 20172244118

About Tufts University

Tufts University, located on campuses in Boston, Medford/Somerville and Grafton, Massachusetts, and in Talloires, France, is recognized among the premier research universities in the United States. Tufts enjoys a global reputation for academic excellence and for the preparation of students as leaders in a wide range of professions. A growing number of innovative teaching and research initiatives span all Tufts campuses, and collaboration among the faculty and students in the undergraduate, graduate and professional programs across the university's schools is widely encouraged.

 

Kilauea Eruption Update: Volcano Summit Overflight (Jan. 11, 2021)

Climate change doesn't spare the smallest

Changing conditions have taken a toll on insects in the tropics, according to research by University of Pennsylvania biologists Daniel Janzen and Winnie Hallwachs

UNIVERSITY OF PENNSYLVANIA

Research News

 

In a normal year, biologists Daniel Janzen and Winnie Hallwachs spend about six months in Costa Rica, where they conduct research and pursue conservation efforts in Área de Conservación Guanacaste (ACG), a World Heritage Site in the northwest that encompasses, a network of parks and preserves they helped establish in the 1980s and that has grown to more than 400,000 acres, including marine, dry forest, cloud forest, and rain forest environments.

In 2020 that is where the married couple was when the COVID-19 pandemic took hold of the world, and compelled them to extend their stay in the virus-free forest until the fall, when they felt safe enough to travel back to their other home in Philadelphia.

"With modern laptops and internet, we could watch the world go by from the safety of the forest," says Janzen, a biology professor in the School of Arts & Sciences.

The extra time in the forest gave them added time for reflection, some of the fruits of which appear in a piece published this week in the Proceedings of the National Academy of Sciences, part of a special issue on global insect decline.

Their contribution draws on data collected since the 1970s on insect abundance and diversity in the tropics, as well as on observations about climate change that go back even further. Although the ACG's protected status has effectively eliminated certain threats to biodiversity loss, such as fire, hunting, deforestation, and pesticide use, the creatures that dwell there are not exempt from what Janzen and Hallwachs call the "heterogenous blanket" of climate change effects.

"What we have seen and lived since the mid-1970s, unambiguously, in our Costa Rican tropical wild world is that the biomass and species richness of insect individuals and species, and their interactions with everything, are decomposing," they write.

To respond to this decline, the scientists have focused their efforts locally. Keeping track of the effects of climate change through consistent monitoring is essential, they say, but what even more critical is engaging the people who own the preserved land: all five million Costa Ricans, in this case. Janzen and Hallwachs are internationally known for their work on this front, having created a model in ACG that empowers and employs local people in conservation work and attempts to facilitate the movement of these processes throughout the national park system and abroad.

In their article, the researchers describe a new approach to expand on these successes: BioAlfa, a nationwide program designed to enlist Costa Ricans themselves in hands-on learning and research about their nation's wild ecosystems. The initiative's name comes from the Spanish for bioliterate, "bioalfabetizado."

"The tradition in tropical countries is that when you want to know something about the biology of your country, expeditions from the North come and do studies of one sort or another and then they take the information home with them," Janzen and Hallwachs say. "What we said is, 'Look, you're capable of doing this all yourselves. You can find all the bugs and the plants and the birds and everything in your own country and, in the process, learn about them.'"

Measuring climate's toll

Janzen and Hallwachs never intended to explicitly study climate change. But its effects have been impossible to ignore. They note that in the 1980s cloud cover was a constant presence over the aptly named cloud forests of ACG, shrouding peaks like Volcán Orosí and Volcán Cacao. Yet the cloud layer shrank by the 1990s and now,many days pass with no cloud cover whatsoever. The result is a drying of forest ecosystems to the detriment of insects and other wildlife that thrive in damp leaf litter and moist conditions, to say nothing of the drying waterways that used to adequately irrigate flatland crops and other development.

The ACG now experiences far more days of temperatures that approach and exceed 90 degrees Fahrenheit than it did in past decades. In addition, a prolonged dry season and greater irregularities in rainfall amount and timing compound the stresses on the biodiversity that lives there. Essentially all tropical organisms use weather cues to guide their lives, and when these change and fracture everyone takes a hit.

Janzen and Hallwachs note that these climatic perturbations have extracted a price on insect biodiversity, a bellwether for impacts on the food web bottom to top. In their report, they compare photos from moth surveys--conducted at night by using a bright light to attract moths to a light-colored sheet, where they can be counted--that indicate a dramatic drop in both moth numbers and species diversity since the 1980s.

Looking at a different types of insects, they say that, despite a constant search effort by ACG's on-the-ground staff of trained and experienced neighbor researchers, the overall number of caterpillars found during regular surveys has fallen in half since 2005, a clear sign of decline.

Supporting this finding, when caterpillars are found, they are now less likely to be parasitized by another insect species. About a fifth of caterpillars were found parasitized in 1985; that has fallen to just 5% in recent years. While this may be a good thing for individual caterpillars, it's a worrying sign overall. Because parasites are hyperspecialized to associate with particular caterpillar species, Janzen says that this lack of parasitized caterpillars suggests that caterpillar numbers are so few that the parasites are unable to locate their desired species and maintain their populations.

"When caterpillar density goes down, the parasites go extinct faster," Janzen says. "So now you've lost that carnivore. And you repeat that a thousand times, 10,000 times."

Being 'kind to the survivors'

Mitigating climate change can be an overwhelming task, and Janzen says that "little guys"--like the economically-small but biodiversity-big country of Costa Rica--are unlikely to make a big-picture impact, except by example. In his eyes, it's essential for small tropical nations to focus energy on creating the conditions that enable the survivors of climate change to maintain a foothold. And that is where BioAlfa comes in.

While international conservation groups contribute money to preserve land in lush, biodiverse locales, such as ACG, the researchers argue that gaining buy-in from all levels of the owners of that preserved land, rather than outsiders who may never step foot in the country, is a necessary ingredient in tropical conservation.

"Charismatic vertebrates, tourist snapshots, and marketable big tree trunks are not even 0.001% of tropical biodiversity," Janzen and Hallwachs write. "The millions to billions of species, and billions of wild interactions still viable, are largely invisible without bioliteracy."

That's why underscoring bioliteracy is the foundation of BioAlfa. The Penn scientists' vision is that, just as elementary school children are taught to read, they should also be taught about the biodiversity around them, and not just in a classroom but by going on the land and learning by doing. And like reading, this knowledge becomes something one takes into whatever social sector becomes home.

This enhanced bioliteracy would then feed back into conservation, they say. Not only might a greater understanding of ecosystems among Costa Ricans translate into greater appreciation but concrete results by using biodiversity information wherever they are. Specifically, Janzen and Hallwachs want to expand the practice of having local researchers carry out their DNA barcoding work, in which species are identified by sequencing stretches of their genetic material.

While the Costa Rican government has committed to the idea of BioAlfa, fully fleshing it out over 10 years will take an estimated $100 million, a hefty sum that Janzen and Hallwachs hope can come from both international governmental and private sources.

"Right now Costa Rica has the political permission for this project, but it also needs the financial permission," says Janzen.

For their part, the couple continues to plug away at building their biodiversity inventory and studies in ACG, while sharing their successes at international meetings (for now virtually), hoping that other tropical nations will follow in their footsteps, protecting land to, in the words of their scientific paper, "be kind to the survivors" of climate change.

As soon as they're vaccinated for the coronavirus, Janzen and Hallwachs plan to be back on the ground in Costa Rica, continuing to pursue that goal.

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Daniel Janzen is professor of biology and Thomas G. and Louise E. DiMaura Term Chair in the School of Arts & Sciences' Department of Biology at the University of Pennsylvania.

Winnie Hallwachs is research biologist in the School of Arts & Sciences' Department of Biology at the University of Pennsylvania.

Scholars link diet, dentition, and linguistics

In a new study that scrutinized the speech patterns of Freddie Mercury, Michael Phelps, and other celebrities, University of Miami researchers offer insights on how diet ultimately reshapes language

UNIVERSITY OF MIAMI

Anthropologist Caleb Everett and former student Sihan Chen used a novel data analysis of thousands of languages, in addition to studying a unique subset of celebrities, to reveal how a soft food diet--contrasted with the diet of hunter-gatherers--is restructuring dentition and changing how people speak.

Their findings, published in Scientific Reports, counter the longstanding belief within the field that maintains that languages are susceptible to the same pressures and so are essentially immune to external factors.

"Our results represent the most compelling evidence to date that languages are very much affected by external factors that differ across populations," said Everett, professor and chair of the Department of Anthropology at the University of Miami.

"Languages change--we can see this in any language--but the thinking has long been that all languages have the same pressures, that there is no difference across populations that make some people more prone than others to use certain sounds," he noted.

Everett said that in the past decade, he and others have produced new evidence suggesting that there might be other factors that are likely to influence speech patterns. He highlighted a "highly publicized" paper published in Science Magazine two years ago, while noting that in addition to this new research, he has spent several years studying how environmental factors such as ambient aridity--extreme dryness--shift speech patterns by reducing vowel usage, which requires more effort to pronounce.

He credited the linguistic acumen and diligence of Chen, his former student now pursuing a doctorate in cognitive science, with advancing the dentition study.

"Sihan took a linguistics course and fell in love with the study of languages. An exceptionally bright student, he demonstrated an incredible aptitude for phonetics and transcribing precisely what's going on in people's mouths as they speak," said Everett, who holds a secondary appointment in psychology.

Yet changes in language take hundreds of years to emerge, Everett explained. So, to obtain a quicker accounting, the two examined the speech patterns of 10 celebrities--including British singing phenom Freddie Mercury and former Olympic swimmer Michael Phelps--a research subset that offered a spectrum of dentition variance.

Mercury's four additional teeth--a hereditary dental condition--caused a famously unusual overbite. (Mercury was embarrassed by the protrusion but resisted any oral surgery believing the anomaly contributed to his exceptional four-octave vocal range.) And Phelps also presented a unique alignment issue.

Everett recognized that, from a research standpoint, utilizing the data from the 10 celebrities was "a bit tricky."

"Freddie Mercury's bite isn't the way that it is because of his diet; there are obviously genetic factors here," he said. "Yet the data from the celebrities provides us insight in real time and contributes to understanding this story of human language that is changing over time."

Additionally, using the publicly accessible videos created a research trail that allowed others to check the data and transcriptions, Everett noted, adding, "the pattern was a lot clearer than I would have expected."

In meticulously transcribing the online videos of the celebrities, Chen focused on establishing the ratio of labiodental sounds such as "f" and "v"--sounds common today but that rarely existed until soft diets became pervasive. Mercury in particular was known to pronounce these particular sounds with abnormal frequency due to his dental abnormality.

"He was really an extreme because he produced these labiodental sounds all over the place even when they shouldn't be there," Everett said. "On the other end of the spectrum Michael Phelps is kind of doing the reverse."

In studying thousands of languages, the researchers established two linguistic camps--hunter-gatherers, whose diets have changed little and whose mouths get a lot more wear, and non-hunter-gatherers. Everett's extensive previous research on indigenous peoples in the Amazon--whose diets remain akin to those of hunter-gatherers--aided the study.

Previous research on the subject has examined whether languages have this sound, or they don't. Everett and Chen delved deeper, analyzing the ratios of frequency between the two research groups.

"We basically adopted a whole new series of methods to test this and we found extensive support for it," he said, yet emphasized that the findings show correlational, not causal, links between diet, dentition, and speech patterns.

"These pressures are subtle and operate over hundreds and thousands of years, so it's a hard thing to know for sure," he said. "But what we see are these probabilistic tendencies in the worlds 7,000 languages.

"These new findings provide a better understanding of why languages--which are a key distinguishing characteristic for anthropologists and a key aspect of being human--take the shape they do, how they diverge, and what factors impact their evolvement," Everett said.