Fish exposed to even small amounts of estrogen produce fewer males

UC biologist is studying water quality downstream of sewage treatment plants

UNIVERSITY OF CINCINNATI

Research News

 

IMAGE: UC IS USING LEAST KILLIFISH AS A MODEL ORGANISM TO STUDY THE EFFECTS OF HORMONES IN DRINKING WATER. THEY ARE AMONG THE SMALLEST VERTEBRATES ON EARTH. view more 

CREDIT: ANDREW HIGLEY/UC CREATIVE

Water tainted with even a small concentration of human hormones can have profound effects on fish, according to a University of Cincinnati biologist.

UC assistant professor Latonya Jackson conducted experiments with North American freshwater fish called least killifish. She found that fish exposed to estrogen in concentrations of 5 nanograms per liter in controlled lab conditions had fewer males and produced fewer offspring.

Scientists have found estrogen at as much as 16 times that concentration in streams adjacent to sewage treatment plants.

The study suggests that even this small dose of estrogen could have significant consequences for wild fish populations living downstream from sewage treatment plants.

The study was published this week in the journal Aquatic Toxicology.

What's special about least killifish is they have a placenta and give birth to live young, Jackson said. It's uncommon among fish, who more typically lay eggs.

Jackson studied a synthetic estrogen called 17α-ethinylestradiol, an active ingredient in oral contraceptives also used in hormone replacement therapy. Estrogen been found in streams adjacent to sewage treatment plants in concentrations of as high as 60 nanograms or more per liter.

"Anything you flush down the toilet or put in the sink will get in the water supply," she said. 

This includes not only medicine people flush (never do that) but also unmetabolized chemicals that get flushed when people use the bathroom.

"Our wastewater treatment systems are good at removing a lot of things, but they weren't designed to remove pharmaceuticals," Jackson said. "So when women on birth control or hormone therapy go to the bathroom, it gets flushed into wastewater treatment plants."

Chronic exposure of fish to estrogen led to smaller populations and a gender ratio imbalance with more females than males.

Now Jackson wants to know how the exposure to hormones such as estrogen and androgen in a female fish affects her offspring. She is collaborating with the U.S. Environmental Protection Agency to examine local waters in southwestern Ohio.

Jackson said the impacts on streams are not limited to fish. Hormones and other chemicals that are not removed during treatment can bioaccumulate in the food chain or end up in our drinking water.

"Our drinking water is not a renewable resource. When we run out of clean drinking water, it's gone," Jackson said. "It's very important that we keep this resource clean."

Coastal permafrost more susceptible to climate change than previously thought

UNIVERSITY OF TEXAS AT AUSTIN

Research News

 

IMAGE: MICAELA PEDRAZAS (LEFT) AND CANSU DEMIR, BOTH GRADUATE STUDENTS AT THE UNIVERSITY OF TEXAS AT AUSTIN JACKSON SCHOOL OF GEOSCIENCES, EXAMINING AN EXPOSED SIDE OF AN ICE WEDGE POLYGON, WHICH... view more 

CREDIT: BAYANI CARDENAS

If you flew from the sea towards the land in the north slope of Alaska, you would cross from the water, over a narrow beach, and then to the tundra. From the air, that tundra would look like a landscape of room-sized polygonal shapes. Those shapes are the surface manifestations of the ice in the frozen ground below, a solidified earth known as permafrost.

Scientists long believed the solid permafrost extended offshore: from the tundra, below that narrow beach and below the seafloor declining at a gentle slope. They viewed that permafrost like solid brick, locking the subsurface--and the vast amounts of carbon it holds--in place.

But new research led by Micaela Pedrazas, who earned her masters at The University of Texas at Austin Jackson School of Geosciences working with Professor Bayani Cardenas, has upended that paradigm. They found permafrost to be mostly absent throughout the shallow seafloor along a coastal field site in northeastern Alaska. That means carbon can be released from coastline sources much more easily than previously thought.

The study was published in Science Advances on Oct. 23 with coauthors from the Jackson School and UT's Marine Science Institute.

Using a geophysical technique called electrical resistivity imaging, the researchers mapped the subsurface beneath Kaktovik Lagoon along the northeastern coast of Alaska over the course of three years.

The results were unexpected. The beach and seafloor were entirely ice-free down to at least 65 feet. On the tundra itself, ice-rich permafrost was detected in the top 16 feet, but below that, the subsurface their imaging mapped was also ice-free.

"This leads to a new conceptual model," Pedrazas said.

Permafrost is found in cold climates that remain frozen during the course of the year. Scientists have been tracking the impact of a warming climate on permafrost because as it melts, permafrost releases its stores of frozen carbon into the atmosphere as methane and carbon dioxide, contributing to climate change.

Permafrost studies have almost exclusively focused on the region beneath the tundra. Because it's not easy to work in such remote locations and under harsh weather conditions, the transition from sea to shore has been largely ignored.

"This study tells us that the coastline is much more complicated than we thought," said co-author Jim McClelland from UT's Marine Science Institute. "It opens up the possibility for routes of water exchange that we weren't thinking about."

Besides global considerations, the work has local impacts. The communities along the coast, most of whom are Inupiat, live on the permafrost. As the permafrost thaws, it accelerates coastal erosion, which carves away at the land on which homes and infrastructure stand. In the Kaktovik region, erosion can be as great as 13 feet per year.

"Their cultural heritage and their welfare is integrated and intricately linked to their environment," Cardenas said. "There's an immediate need to understand what's happening in these lagoons."

The new paradigm requires reimagining the coastal Arctic ecosystem as well. Liquid groundwater means that carbon and nutrients can move between the tundra and the lagoon. It also means that saltwater can move beneath the tundra, potentially affecting freshwater sources.

Paul Overduin, who wasn't involved in the research, but who studies permafrost at Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, said that this work is the first step in understanding permafrost's transition from sea to shore.

"As is often the case, when we start looking at something people don't know much about, you open up a whole bunch of questions that needed to be looked at," he said. "That's what's really exciting here."

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The research was funded by the Geology Foundation at The University of Texas at Austin and the National Science Foundation through the Beaufort Lagoon Ecosystems LTER, the Geological Society of America and the Ivanhoe Foundation. The Kaktovik Inupiat Corporation and the U. S. Fish and Wildlife Service also provided permissions and support.

The hidden threat of the home office

Yes, there are benefits to working at home; but there are traps, too

NORWEGIAN UNIVERSITY OF SCIENCE AND TECHNOLOGY

Research News

 

 

It may seem a bit contradictory at first glance, but increased flexibility in our workday may have given us less flexibility in the work itself.

The daily press and the nascent research literature on COVID-19 speculate on the long-term consequences of the coronavirus situation. These could change the way we think about the methods we employ in our working life, especially with regard to home offices and digital collaboration.

Several large companies, both internationally and nationally, have announced that they plan to continue the option of working from home for anyone who also wishes after the pandemic. The arguments for this include:

Greater flexibility in organizing work and family life situations seems to significantly reduce stress for many people.

Time that was previously used for commuting or travelling between meetings can now be used for other things, which in turn may lead to higher productivity.

One common argument is that a home office situation provides fewer distractions and can make us more efficient.

Employers, for their part, see an opportunity for reduced travel costs and less need for office space.

Working from home is also happening in academia, and several universities have said that the home office option will continue.

On the other hand, it has been pointed out that people cannot work exclusively in physically separate environments. We need opportunities to meet with colleagues and experience the social cohesion and replenishment this provides.

The consequences of this kind of distributed work situation for workplace practices constitute an important aspect that has received less attention so far. How does working from home affect collaborative efforts and the quality of work, both in smaller teams and in larger work communities?

The article "Learning of academics in the time of the Coronavirus pandemic," describes how academic practices changed, quite significantly, under the conditions we have worked under since March.

One conclusions is that we cannot expect work practices to remain the same when we move them. As conditions change around practices, so do the practices themselves.

In two parallel projects, an international coalition of researchers led by the Norwegian University of Science and Technology (NTNU) collected data from students and academic staff. They focused on their work and study situations during the corona pandemic.

The data includes 1600 students and 16 lecturers in a course called Experts in Teamwork offered at NTNU. Students provided feedback through questionnaires, written exam reports and in-depth interviews. The lecturers represented different faculties and departments and were also interviewed in depth.

The preliminary findings show great variations in the consequences that the new work and study situations have had for individuals and for groups.

Some people became more efficient in their new work setting, for example because they had fewer distractions and work became easier to prioritize. But others became less efficient, for example due to lower motivation and lack of daily structure.

Some individuals thought it was beneficial to have more peace and flexibility in their daily life, while others felt lonelier and less motivated due to the lack of social and physical contact with fellow students and colleagues.

A number of the academic staff also had a much busier schedule due to home schooling their children. This factor is less relevant in a situation without a pandemic.

The study also found many of the positive elements of distributed teamwork and working digitally that are mentioned at the beginning of our article.

However, one finding stands out as a paradox.

While working from a home office, or as a distributed team, provides significantly increased flexibility for the work situation, it could provide less flexibility in carrying out the work, both in terms of meeting colleagues, collaborating and teaching.

This flexibility issue, or paradox, is largely related to a much greater need for structure, planning and clear communication in the digital modality. Meetings and teaching need to be planned in much more detail, and the digital form makes it difficult to deviate from the plan.

We lose the ability to pick up cues from the room, like we do when we are in a physical space together. Several communication-related aspects of working digitally also make it difficult to achieve a good flow, as well as to make spontaneous and necessary changes.

The researchers also found that the threshold for making small and necessary clarifications with collaborators is significantly higher in the digital realm. The flexibility to complete a task is therefore reduced and can affect the quality of what we do.

For example, people risk working alone with a task for too long, assuming rather than clarifying along the way. We don't want to disturb people, and we don't know what they are doing right now. Researchers found this to be the case both for students who worked synchronously, and for academics who mostly worked asynchronously.

Home offices may offer benefits for many, but it is hardly advantageous for everyone. More people will probably choose to work from home more than they did before, even when the pandemic has subsided. But having the opportunity to convene physically is still important, not only for each of us to meet our social needs, but also for the employer and for the quality of the work.

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Source: Learning of academics in the time of the Coronavirus pandemic. E. Sjølie, S. Francisco, K. Mahon, M. Kaukko, S. Kemmis - Journal of Praxis in Higher Education, 2020.

Knowing the model you can trust - the key to better decision-making

CRANFIELD UNIVERSITY

Research News

 

As much of Europe is engulfed by a second wave of Covid-19, and track and trace struggles to meet demand, modelling support tools are being increasingly used by policymakers to make key decisions. Most notably, models have been used to predict the Covid-19 R0 rate - the average rate of secondary infections from a single infection, which has formed the basis for many lockdown decisions across the UK.

Models can represent the most effective tool for identifying interventions that can balance the risks of widespread infection and help assess socio-economic disruption until an effective treatment is established. However, not all models are equal, and differences in model predictions during the Covid-19 pandemic have caused confusion and suspicion.

A recent paper 'Three questions to ask before using model outputs for decision support' published in Nature Communications aims to help decision makers choose the best available model for the problem at hand. The paper proposes three screening questions that can help critically evaluate models with respect to their purpose, organisation, and evidence, and enable more secure use of models for key decisions by policy makers.

One of the authors of the paper, Dr Alice Johnston, Lecturer in Environmental Data Science at Cranfield University, said: "From Covid-19 to the stock market, models are increasingly used by policymakers to support their decisions.

"However, different models are based on different assumptions and so can produce conflicting results, even when they represent the same system. Models used early on in the Covid-19 pandemic were a prime example of this, which led to confusion over which models to trust to support the decision-making process. This really highlights the need for clear communication of a model's context, so that policymakers have confidence in which models to trust.

"We propose that before engaging with a model, policymakers ask themselves three screening questions focusing on the model's purpose, organisation and evidence base, with the aim of bringing greater clarity to the decision-making process."

 

Residents of U.S. counties with more connections to China or Italy were more likely to follow early pandemic restrictions

Social connections with COVID-19-affected areas increase compliance with mobility restrictions

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

Research News

 

Residents of U.S. counties with more social connections (measured as Facebook friends) to China or Italy - the first countries to report major COVID-19 outbreaks - were more likely to adhere to social distancing restrictions at the onset of the pandemic, according to a new study. The findings suggest that social networks supplied pandemic-related information that significantly influenced individual behavior. However, social ties also could have negative effects on pandemic-related behavior. For instance, areas within the U.S. with more connections to counties with low education levels, high proportions of 2016 Trump voters, and high fractions of people who deny the existence of climate change experienced less adherence to mobility restrictions during the early pandemic. Previous research suggests online social connections may act as warning systems during natural disasters and can impact personal health decisions by spreading both facts and misinformation. To explore the role of these connections in the context of COVID-19-era social distancing, Ben Charoenwong and colleagues measured social connectedness between U.S. counties and foreign countries using aggregated, anonymized data from Facebook's Social Connectedness Index. The researchers combined this data with anonymized, county-level mobile phone location data that served as a proxy for adherence to social distancing measures between February 1 and March 30, 2020. They found that a one-standard-deviation increase in social connections with China or Italy correlated with a nearly 50% increase in the effectiveness of mobility restrictions. The authors also conclude that differences in how effectively Democrats and Republicans adhere to social distancing arise from discrepancies in the information they receive (facilitated by their social connections) rather than due to biases in how they interpret that information. "This finding has important policy implications, as it suggests changes in the information environment can boost the effectiveness of non-pharmaceutical interventions," the authors write.

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Study helps explain declines in death rates from COVID-19

NYU LANGONE HEALTH / NYU SCHOOL OF MEDICINE

Research News

 

Fewer New Yorkers are dying from the coronavirus than health experts had anticipated, a new study shows. Regional death rates have dropped from the highs seen at the start of the outbreak, partially due to a shift in the population contracting the disease toward those who are more resilient.

After New York became the epicenter for the pandemic in early March, with tens of thousands dying from COVID-19, experts had expected that the infection would remain as deadly in the following months.

Instead, a new investigation showed that by mid-August the death rate in those hospitalized with coronavirus-related illness had dropped from 27 percentage points to about 3 percentage points. Led by researchers at NYU Grossman School of Medicine, the study showed that a younger, healthier group of people were getting infected and were arriving at the hospital with less-severe symptoms than those infected in the spring.

However, the researchers' analysis showed that these factors accounted for only part of the improvement in survival. The rest, they suspect, resulted from health care providers' growing experience with the coronavirus. For example, physicians learned that resting COVID-19 patients on their stomachs rather than their backs and delaying the use of ventilators as long as possible were more effective practices, say the study authors. Drugs likely helped as well. In addition, other factors such as decreasing hospital volumes, less exposure to infection, and earlier testing and treatment, may have played a role.

"Our findings suggest that while COVID-19 remains a terrible disease, our efforts to improve treatment are probably working," says study lead author Leora Horwitz, MD, an associate professor in the Department of Population Health at NYU Langone Health. "Even in the absence of a silver-bullet treatment or vaccine, we are protecting more of our patients through a host of small changes," says Horwitz, who is also director of the Center for Healthcare Innovation and Delivery Science at NYU Langone.

New York was among the first states to grapple with a severe outbreak of COVID-19. By contrast, death rates in more recent waves in southern and western regions of the country, which also had younger, healthier coronavirus patients, have been lower, says Horwitz. However, it had remained unclear whether the virus was less deadly due to the different patient demographics or improved care.

Horwitz says the new study, publishing online next week in the Journal of Hospital Medicine, is the most detailed analysis to date of coronavirus death rates over time. By accounting for age, obesity, and other key factors, the researchers were able to eliminate some explanations from the analysis.

For the investigation, the research team analyzed 5,263 patient records of people treated for COVID-19 at NYU Langone hospitals in New York City and Long Island between March 1 and Aug. 8. Using a range of risk factors for the disease as well as indicators of the severity of the illness upon hospitalization, the study authors developed a model that predicted likelihood of death for each patient.

According to the findings, the likelihood of death was on average 22 percentage points lower in August than in March for most critically ill patients.

The average age of hospitalized COVID-19 patients also dropped from 63 to 47. In March, while 73 percent had chronic conditions like lung disease and diabetes, by mid-June only about 65 percent had such risk factors.

"Other pandemic hotspots should take hope from the lessons learned here in New York," says study senior author Christopher Petrilli, MD, an assistant professor in the Department of Medicine at NYU Langone. "If we can do better at managing the disease, they can too."

Still, he adds that the research team next plans to expand the investigation to hospitals outside of New York.

Petrilli also cautions that while death rates are improving, COVID-19 still causes symptoms in some people that continue long after hospital patients are sent home, including fatigue, blood clots, and lung damage.

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NYU Grossman School of Medicine provided all the necessary funding for the study.

In addition to Horwitz and Petrilli, other NYU Langone researchers include Simon Jones, PhD; Robert Cerfolio, MD; Fritz Francois, MD; Joseph Greco, MD; and Bret Rudy, MD.

 

SARS-CoV-2 antibodies detectable up to seven months post COVID-19 onset, shows new Portuguese study

INSTITUTO DE MEDICINA MOLECULAR

Research News

 

A new study led by Marc Veldhoen, principal investigator at Instituto de Medicina Molecular João Lobo Antunes (iMM; Portugal) with an interdisciplinary team of clinicians and researchers from Faculdade de Medicina da Universidade de Lisboa (FMUL) and Centro Hospitalar Lisboa Norte (CHLN) and collaborators at Instituto Português do Sangue e Transplantação (IPST), shows that 90% of subjects have detectable antibodies 40 days up to 7 months post contracting COVID-19. These results, now published in the scientific journal European Journal of Immunology, also show that age is not a confounding factor in levels of antibodies produced, but disease severity is.

This comprehensive and cross-sectional study was thought off in the early days of the pandemic, back in March 2020. The researchers Patrícia Figueiredo-Campos and Birte Blankenhaus, first authors of this study, setup an in-house sensitive specific and versatile COVID-19 serology test. The optimization and validation of the assay was performed as part of Serology4COVID, a consortium of 5 research institutes of Lisbon and Oeiras. Collaborating with physicians in the campus of the Santa Maria Hospital, the research team started to monitor the antibody levels of over 300 COVID-19 hospital patients and healthcare workers, and over 200 post-COVID-19 volunteers.

"Our immune system recognizes the virus SARS-CoV-2 as harmful and produces antibodies in response to it, which helps to fight the virus." "The results of this 6 months cross-sectional study show a classic pattern with a rapid increase of antibody levels within the first three weeks after COVID-19 symptoms and, as expected, a reduction to intermediate levels thereafter", explains Marc Veldhoen, adding that "in this early response phase, on average men produce more antibodies than women, but levels equilibrate during the resolution phase and are similar between the sexes in the months after SARS-CoV-2 infection". In the acute phase of the immune response, the team observed higher antibody levels in subjects with more severe disease. Also, the results show that age is not a confounding factor for the production of antibodies, as no significant differences were observed between age groups. Globally, 90% of subjects have detectable antibodies up to 7 months post contracting COVID-19.

Next, the research team, evaluated the function of these antibodies, i.e. their neutralizing activity against the virus SARS-CoV-2. In collaboration with Instituto Português do Sangue e Transplantação (IPST), the research team analysed the neutralizing capacity of the antibodies produced by the patients and volunteers. "Although we observed a reduction in the levels of antibodies over time, the results of our neutralizing assays have shown a robust neutralisation activity for up to the seventh month post-infection in a large proportion of previously virus-positive screened subjects", explains Marc Veldhoen.

On the importance of this study, Marc Veldhoen states: "Our work provides detailed information for the assays used, facilitating further and longitudinal analysis of protective immunity to SARS-CoV-2. Importantly, it highlights a continued level of circulating neutralising antibodies in most people with confirmed SARS-CoV-2. The next months will be critical to evaluate the robustness of the immune response to SARS-CoV-2 infection, and to find clues for some open questions, such as the duration of circulating antibodies and the impact of reinfection."

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This study was conducted at iMM in collaboration with the Biobank-IMM, Lisbon Academic Medical Centre, Faculdade de Medicina da Universidade de Lisboa (FMUL), Centro Hospitalar Lisboa Norte (CHLN) and Instituto Português do Sangue e Transplantação (IPST). The SARS-CoV-2 protein used in the serology testing was produced at Instituto de Biologia Experimental e Tecnológica (iBET) as part of the Serology4COVID consortium. This work was funded by the European Union H2020 ERA project EXCELLtoINNOV (No 667824), the Fundação para a Ciência a Tecnologia and Sociedade Francisco Manuel dos Santos.

 New data on increasing cloth mask effectiveness

Widespread use of masks remains the primary tool for combating COVID-19 and economic shutdowns, cost benefit analysis suggests government subsidies for masks bear great returns

SOCIETY FOR RISK ANALYSIS

Research News

 

Recent FDA chief Dr. Scott Gottlieb argued that he'd "rather try to get everyone in masks" and "try to get them in high-quality masks because we know it's going to slow down the transmission."

Against this backdrop, a new study published in Risk Analysis, "Reinventing cloth masks in the face of pandemics," by Stephen Salter, P.Eng., describes how Effective Fiber Mask Programs (EFMPs) can help communities find a balance between the economy and curbing community spread.

A separate study by Stadnytskyi, et al. estimates that one minute of loud speaking generates at least 1,000 virion-containing droplets that remain airborne for more than eight minutes. If everyone uses effective masks, the benefit is compounded because each person's mask reduces the number of particles they transmit, and also the number of particles they inhale.

The new study in Risk Analysis suggests that the effectiveness of cloth masks can be improved by using a non-woven material such as cotton batting. Increasing the surface area of fibers exposed to moving air improves filtering efficiency because the smaller particles are absorbed onto the fibers. In May and June of 2020, 17 handmade cotton batting masks underwent 35 tests using commercial quantitative fit testing equipment to determine their filtering effectiveness. The results showed average filtering effectiveness of 76 to 90 percent against aerosol particles.

If an Effective Fiber Mask (EFM) costs $6 and can be used 30 times for four hours each, the cost per hour of use would be $0.05. Another study, by Abaluck et al., estimated the value of cloth masks during the COVID-19 pandemic, and concluded, "...the benefits of each additional cloth mask worn by the public are conservatively in the $3,000-$6,000 range due to their impact in slowing the spread of the virus." This cost-benefit ratio suggests governments should consider subsidizing the cost of EFMs for the public.

Governments can take a leadership role by rapidly implementing EFMPs to help reduce transmission of COVID-19, according to Salter. To implement an EFMP, a government would set performance standards for cloth masks, invite manufacturers to submit their mask designs for testing, allow manufacturers to label their approved designs, ask or require the public to wear only approved cloth masks, educate the public to use face masks correctly, and encourage manufacturers to continuously improve their designs.

"I am confident Effective Fiber Masks can play an important role in reducing the risk of transmission of COVID-19," states Salter. "Every country can rapidly implement an Effective Fiber Mask Program, and I hope leaders will act quickly to reduce suffering in this way."

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Abaluck, J., Chevalier, J. A., Christakis, N. A., Forman, H. P., Kaplan, E. H., Ko, A., & Vermund, S. H. (2020). The case for universal cloth mask adoption and policies to increase supply of medical masks for health workers. SSRN Electronic Journal, https://doi.org/10.2139/ssrn.3567438

Stadnytskyi, V., Bax, C. E., Bax, A., & Anfinrud, P. (2020). The airborne lifetime of small speech droplets and their potential importance in SARS?CoV?2 transmission. Proceedings of the National Academy of Sciences of the United States of America, 117(22), 11875- 11877. https://doi.org/10.1073/pnas.2006874117

About SRA

The Society for Risk Analysis is a multidisciplinary, interdisciplinary, scholarly, international society that provides an open forum for all those interested in risk analysis. SRA was established in 1980 and has published Risk Analysis: An International Journal, the leading scholarly journal in the field, continuously since 1981. For more information, visit http://www.sra.org.

 

Study reveals bat-winged dinosaurs had short-lived gliding abilities

THE UNIVERSITY OF HONG KONG

Research News

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IMAGE: FIGURE 1. LASER-STIMULATED FLUORESCENCE (LSF) IMAGE OF THE FOSSIL OF YI QI, A BAT-WINGED DINOSAUR FROM THE LATE JURASSIC OF NORTHERN CHINA. view more 

CREDIT: DECECCHI ET AL. 2020.

Research Assistant Professor Dr Michael PITTMAN (Vertebrate Palaeontology Laboratory, Division of Earth and Planetary Science & Department of Earth Sciences) at The University of Hong Kong (HKU), recently showed that powered flight potential evolved at least three times and that many ancestors of close bird relatives neared the thresholds of powered flight potential, suggesting broad experimentation with wing-assisted locomotion before flight evolved (see Notes). In a new study, Dr Pittman and Dr Thomas DECECCHI, Assistant Professor of Biology at Mount Marty University, broadened their collaboration on flight origins research to the scansoriopterygids, a rare group of theropod dinosaurs believed to glide using strange bat-like wings. Living around 160 million years ago in what is now northern China, they weighed about 1kg and probably feed on insects, seeds, and other plants. For the first time, Dr Dececchi, Dr Pittman and the rest of the international team tested this gliding hypothesis through quantitatively reconstructions of scansoriopterygid flight capabilities. If confirmed, this bat-winged gliding lifestyle will be unique to scansoriopterygids as it is not found in any other dinosaurs. It would also make scansoriopterygids the most distantly related theropod dinosaurs to birds that could glide. Thus, testing this gliding hypothesis is important for understanding how flight evolved among theropod dinosaurs.

Scansoriopterygids were an evolutionary dead-end

To do this, fossils were scanned using Laser-Stimulated Fluorescence (LSF), a laser-based imaging technique co-developed at HKU, which can reveal bone and soft tissue details that can't be seen under standard white light. The team then used mathematical models to predict how scansoriopterygids might have flown, testing many different variables, including weight, wingspan, and muscle placement. They found that scansoriopterygids did not have powered flight potential but were capable of clumsy gliding. "They could glide, but they weren't very good at it. If I were them I would have been particularly worried about predators!" says Dr Pittman. Scansoriopterygids were not part of the independent originations of powered flight in dinosaurs, which happened at least three times: once in birds and twice in dromaeosaurid 'raptors'. Their poor gliding capabilities and existence in a short interval of time suggests that they were an evolutionary dead-end. But what exactly doomed this strange experiment? "The two scansoriopterygid species we studied were so poorly capable of being in the air that they just got squeezed out," says Dr Thomas Dececchi. "Maybe you can survive a few million years underperforming, but with birds, pterosaurs, gliding mammals all around, scansoriopterygids were simply squeezed out until they disappeared."

Gliding is not an efficient form of flight as it can only be done if the scansoriopterygids are already at a high point. However, it did help keep them out of danger. "If an animal needs to travel long distances, gliding costs a bit more energy at the start, but it's faster. It can also be used as an escape hatch. It's not a great thing to do, but sometimes it's a choice between losing a bit of energy and being eaten," says Dececchi. "Once scansoriopterygids were put under pressure, they just lost their space. They couldn't win on the ground. They couldn't win in the air. They were done." The new findings support the emerging picture that dinosaurs evolved flight in several different ways before modern birds evolved. Asked about future plans, Pittman added, "Our team continues to uncover a greater sense of the breadth of experimentation involved in getting dinosaurs into the air. We plan to reveal even more details moving forward, particularly the different routes taken by dinosaurs to occupy the skies."

The paper 'Aerodynamics show membranous-winged theropods were a poor gliding dead-end' is published in iScience and can be accessed here: https://www.cell.com/iscience/fulltext/S2589-0042(20)30766-5

Images download and captions:

https://www.scifac.hku.hk/press

Notes:

1. Bird beak revealed by HKU-codeveloped laser imaging informs early beak form, function, and development (Sept 2020):
https://www.hku.hk/press/news_detail_21574.html

2. Landmark HKU-led volume on past progress and new frontiers in the study of early birds and their close relatives (August 2020):
https://hku.hk/press/press-releases/detail/21459.html

3. Most close relatives of birds neared the potential for powered flight but few crossed its thresholds (August 2020):
https://www.hku.hk/press/press-releases/detail/21405.html

4. Ancient birds out of the egg running(March 2019):
https://www.hku.hk/press/press-releases/detail/19256.html

5. HKU imaging technology shows first discovered fossil feather did not belong to iconic bird Archaeopteryx (Feb 2019):
https://www.hku.hk/press/press-releases/detail/19063.html

6. HKU palaeontologist discovers new bird-like dinosaur with flight associated feathers - Jianianhualong tengi (May 2017):
https://www.hku.hk/press/news_detail_16295.html

7. Major breakthrough in knowledge of dinosaur appearance HKU palaeontologist reconstructs feathered dinosaurs in the flesh with new technology (March 2017):
https://www.hku.hk/press/press-releases/detail/15989.html

8. Scientists reveal how dinosaurs became able to shake their tail feathers (May 2013):
https://www.hku.hk/press/press-releases/detail/9693.html

  

 

Metal deposits from Chinese coal plants end up in the Pacific Ocean, USC research shows

UNIVERSITY OF SOUTHERN CALIFORNIA

Research News

 

Emissions from coal-fired power plants in China are fertilizing the North Pacific Ocean with a metal nutrient important for marine life, according to new findings from a USC-led research team.

The researchers believe these metals could change the ocean ecosystem, though it's unclear whether it would be for better or worse.

The study shows that smoke from power plants carries iron and other metals to the surface waters of the North Pacific Ocean as westerly winds blow emissions from Asia to North America. Peak measurements show that up to nearly 60% of the iron in one vast swath of the northern part of the ocean emanates from smokestacks.

"It has long been understood that burning fossil fuels alters Earth's climate and ocean ecosystems by releasing carbon dioxide into the atmosphere," said Seth John, lead author of the study and an assistant professor of Earth sciences at the USC Dornsife College of Letters, Arts and Sciences. "This work shows fossil fuel burning has a side effect: the release of iron and metals into the atmosphere that carry thousands of miles and deposit in the ocean where they can impact marine ecosystems."

"Certain metal deposits could help some marine life thrive while harming other life,'' he added. "There are inevitable tradeoffs when the ocean water's chemistry changes."

The study was published on Thursday in the Proceedings of the National Academy of Sciences. Researchers from USC, Columbia University, University of Washington, MIT and the University of Hawaii, among others, collaborated.

USC-led team confirms that ocean metals stem from China

While wind-blown mineral dust from deserts has long been considered an important source of iron to open ocean waters, the new study shows how manmade sources contribute important micronutrients that plankton and algae need. Moreover, the study shows how fossil fuel burning affects not only global warming but marine environments, too.

Previous studies have shown widely divergent estimates about how much iron is carried from various land-based sources to the ocean, especially from anthropogenic sources. Iron is a key limiting factor for marine productivity for about one-third of the world's oceans.

Instead, the USC-led research team measured metals in surface seawater. They focused on a remote part of the Pacific Ocean, hundreds of miles north of Hawaii and about midway between Japan and California. The region is downwind of industrial emissions in east Asia.

In May 2017, they boarded a research vessel and took water samples along a north-south transect at latitudes between 25 degrees and 42 degrees north. They found peak iron concentrations in about the middle, which corresponded with a big wind event over east Asia one month before. The peak iron concentrations are about three times greater than background ocean measurements, the study shows.

In addition, the scientists found elevated lead concentrations coincided with the iron hot spots. Other research has shown that most of the lead at the ocean surface comes from manmade sources, including cement plants, coal-fired power plants and metal smelters.

Moreover, the metals in the seawater samples bear telltale traces of Chinese industrial sources, the study says.

"When we collected samples in the ocean, we found that the iron isotope and lead isotope 'fingerprints' from seawater matched those of anthropogenic pollution from Asia," said Paulina Pinedo-Gonzalez, a USC post-doctoral scientist and study author who is now at the Lamont-Doherty Earth Observatory at Columbia University.

Finally, the scientists also ruled out upwelling from the deep ocean as a source of the metals by testing water samples at depth.

What does the abundance of metals mean for marine life?

The study has important implications for marine life in the ocean. The North Pacific notably lacks iron, a key micronutrient, so an influx of metals and other substances can help build the foundation for a new ecosystem -- a 'good news, bad news' outcome for Earth.

"Microscopic iron-containing particles released during coal burning impacts algae growth in the ocean, and therefore the entire ecosystem for which algae form the base of the food chain," John explained. "In the short term, we might think that iron in pollution is beneficial because it stimulates the growth of phytoplankton, which then take carbon dioxide out of the atmosphere as they grow to offset some of the carbon dioxide released during the initial burning process.

"However, it's totally unsustainable as a long-term geoengineering solution because of the deleterious effects of pollution on human health. Thus, the take-home message is perhaps a better understanding of an unintended side effect of coal burning and the ways in which that can impact ocean ecosystems thousands of miles away."

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The study authors are Paulina Pinedo-Gonzalez, a former post-doctoral scholar at USC, now affiliated with the Lamont-Doherty Earth Observatory of Columbia University; Seth John and Nicholas J. Hawco of USC; Randelle M. Bundy and E. Virginia Armbrust of the University of Washington; Michael J. Follows of MIT; B.B. Cael of National Oceanography Center of the United Kingdom; and Angelicque E. White, Sara Ferron and David M. Karl of the University of Hawaii at Manoa.

The research was supported by the Simons Foundation (award #4265705SP).