Engineers and biologists join forces to reveal how seals evolved to swim

New research combines cutting-edge engineering with animal behaviour to explain the origins of efficient swimming in Nature's underwater acrobats: Seals and Sea Lions

MONASH UNIVERSITY

Research News

 

New research combines cutting-edge engineering with animal behaviour to explain the origins of efficient swimming in Nature's underwater acrobats: Seals and Sea Lions.

Seals and sea lions are fast swimming ocean predators that use their flippers to literally fly through the water. But not all seals are the same: some swim with their front flippers while others propel themselves with their back feet.

In Australia, we have fur seals and sea lions that have wing-like front flippers specialised for swimming, while in the Northern Hemisphere, grey and harbor seals have stubby, clawed paws and swim with their feet. But the reasons why these two different ways of swimming evolved has perplexed biologists for generations. Is one style better than the other?

But now a Monash University-led interdisciplinary study published in Current Biology has used cutting-edge computer simulations alongside footage of live seals to finally answer this evolutionary mystery.

"The difference in swimming style between forelimb and hindlimb propelled seals is so great that these groups were originally thought to have evolved from separate land-dwelling ancestors," said lead study author Dr David Hocking from the Monash University School of Biological Sciences, "but the genetics clearly shows that all living seals come from the same group of animals."

The question is, how could such different swimming styles evolve within the one animal group?

To reveal the answer, Dr Hocking teamed up with Monash University engineer Dr Shibo Wang from the Department of Mechanical and Aerospace Engineering, and used advanced Fluid Dynamics simulations to show how water flows around seal flippers of different shapes.

"Our analysis showed that some Antarctic seals, like leopard seals, actually have very streamlined, wing-like forelimbs, despite being from the 'foot-propelled' seal family," said Dr Wang. This is supported by footage of live leopard seals swimming at Taronga Zoo, where they used their front limbs to swim in a similar way to the fur seals and sea lions.

This discovery shows how wing-like flippers can evolve in seals that already swim with their back feet, providing a pathway for the evolution of forelimb swimming in the fur seals and sea lions.

"Wing-like flippers help leopard seals to surge forward and ambush fast-swimming penguins," said Associate Professor Alistair Evans who also collaborated on the study, "and it seems likely that the earliest sea lions also needed this extra speed to capture their preferred prey: schooling fish".

"We finally have a window into the early evolution of swimming in seals," Dr Evans said.

But as well as explaining the origin of seals, this study also has a more practical outcome: improved human designs. "Seals have had millions of years to perfect their swimming, and they can teach us a thing or two about underwater grace and elegance," said Dr Hocking. "Learning from them may help us to improve the design of human-built machines like underwater drones and submersibles, increasing their speed, manoeuvrability or energy efficiency."

Who knows? Perhaps in future we will be able to know how it feels to swim like a seal thanks to seal-shaped submarines.

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The cerebellum may have played an important role in the evolution of the human brain

Study compares epigenetic modifications to DNA in the cerebellum of humans, chimpanzees and monkeys

PLOS

Research News

 

The cerebellum--a part of the brain once recognized mainly for its role in coordinating movement--underwent evolutionary changes that may have contributed to human culture, language and tool use. This new finding appears in a study by Elaine Guevara of Duke University and colleagues, published May 6th in the journal PLOS Genetics.

Scientists studying how humans evolved their remarkable capacity to think and learn have frequently focused on the prefrontal cortex, a part of the brain vital for executive functions, like moral reasoning and decision making. But recently, the cerebellum has begun receiving more attention for its role in human cognition. Guevara and her team investigated the evolution of the cerebellum and the prefrontal cortex by looking for molecular differences between humans, chimpanzees, and rhesus macaque monkeys. Specifically, they examined genomes from the two types of brain tissue in the three species to find epigenetic differences. These are modifications that do not change the DNA sequence but can affect which genes are turned on and off and can be inherited by future generations.

Compared to chimpanzees and rhesus macaques, humans showed greater epigenetic differences in the cerebellum than the prefrontal cortex, highlighting the importance of the cerebellum in human brain evolution. The epigenetic differences were especially apparent on genes involved in brain development, brain inflammation, fat metabolism and synaptic plasticity--the strengthening or weakening of connections between neurons depending on how often they are used.

The epigenetic differences identified in the new study are relevant for understanding how the human brain functions and its ability to adapt and make new connections. These epigenetic differences may also be involved in aging and disease. Previous studies have shown that epigenetic differences between humans and chimpanzees in the prefrontal cortex are associated with genes involved in psychiatric conditions and neurodegeneration. Overall, the new study affirms the importance of including the cerebellum when studying how the human brain evolved.

Guevara adds, "Our results support an important role for the cerebellum in human brain evolution and suggest that previously identified epigenetic features distinguishing the human neocortex are not unique to the neocortex."

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Peer reviewed Experimental study People; Animals; Cells

Citation: Guevara EE, Hopkins WD, Hof PR, Ely JJ, Bradley BJ, Sherwood CC (2021) Comparative analysis reveals distinctive epigenetic features of the human cerebellum. PLoS Genet 17(5): e1009506. https://doi.org/10.1371/journal.pgen.1009506

Funding: The work was supported by funding from the Center for the Advanced Study of Human Paleobiology at The George Washington University (https://cashp.columbian.gwu.edu/) to CCS and EEG, Duke University Department of Evolutionary Anthropology to EEG (https://evolutionaryanthropology.duke.edu/), the James S. McDonnell Foundation (https://www.jsmf.org/) Grant #220020293 to CCS, and National Science Foundation (https://www.nsf.gov/) Grants SMA-1542848 to CCS, WDH, and BJB; EF-2021785 to CCS, and BSC-1919780 to CCS and EEG. The National Chimpanzee Brain Resource was supported by National Institutes of Health (https://www.nih.gov/) Grant NS092988 to CCS and WDH. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Many consumers misinterpret food date labels, yet use them with confidence

Consumer education is needed to increase understanding of food date labels according to a new study in the Journal of Nutrition Education and Behavior

ELSEVIER

Research News

 

IMAGE: EXAMPLE OF AN ILLUSTRATED MESSAGE. view more 

CREDIT: JOURNAL OF NUTRITION EDUCATION AND BEHAVIOR

Philadelphia, May 6, 2021 - Misunderstanding food date labeling is common and educational communications are needed to improve consumer understanding, according to a new study in the Journal of Nutrition Education and Behavior, published by Elsevier.

Does it mean "spoiled - throw it out," or "might not taste as good as it could anymore?" Food date labels (e.g., "USE By August 16") can play an important role in helping consumers make informed decisions about food, and ultimately prevent unsafe consumption and waste of food. Researchers surveyed 2,607 adults in the United States to assess consumer understanding of the streamlined 2-date labeling system and explore the relative effectiveness of educational messages in increasing understanding.

"Our study showed that an overwhelming majority of consumers say that they use food date labels to make decisions about food and say they know what the labels mean," said Catherine Turvey, MPH, Department of Exercise and Nutrition Sciences, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA. "Despite confidently using date labels, many consumers misinterpreted the labels and continued to misunderstand even after reading educational messaging that explained the labels' meaning."

Less than half (46 percent) of study respondents knew that the "BEST If Used By" label specifically indicates that food quality may deteriorate after the date on the label. Less than one-quarter (24 percent) of study respondents knew that the "USE By" label means that food is not safe to eat after the date on the label.

Researchers explored if framing the messages with values like saving money or avoiding waste, would impact the effectiveness of messages at increasing consumer understanding. None of the seven value frames tested was significantly more effective at increasing understanding than another, but all messages significantly increased consumer's general understanding of the labels.

After viewing educational messages, 37 percent of consumers still did not understand the specific meaning of the "BEST If Used By" label and 48 percent did not understand the specific meaning of the "USE By" label.

"Responses to the survey suggest that date labels are so familiar that some consumers believe they are boring, self-explanatory, or common sense despite misunderstanding the labels," said Ms. Turvey. "Unwarranted confidence and the familiarity of date labels may make consumers less attentive to educational messaging that explains the food industry's labeling system."

Future communication campaigns will have to capture the attention of people who think they already know what date labels mean, find the information tedious, or are satisfied with a rough understanding of labels. Educating consumers about the meaning of the labels has growing implications for food waste and food safety as the 2-date labeling system becomes more widely adopted and gains support from non-profits and government institutions.

Many consumers misinterpret food date labels, yet use them with confidence (AUDIO)

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Misunderstanding food date labeling is common and educational communications are needed to improve consumer understanding, according to a new study.

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Hydrogen instead of electrification? Potentials and risks for climate targets

POTSDAM INSTITUTE FOR CLIMATE IMPACT RESEARCH (PIK)

Research News

 

Hydrogen-based fuels should primarily be used in sectors such as aviation or industrial processes that cannot be electrified, finds a team of researchers. Producing these fuels is too inefficient, costly and their availability too uncertain, to broadly replace fossil fuels for instance in cars or heating houses. For most sectors, directly using electricity for instance in battery electric cars or heat pumps makes more economic sense. Universally relying on hydrogen-based fuels instead and keeping combustion technologies threatens to lock in a further fossil fuel dependency and greenhouse gas emissions.

"Hydrogen-based fuels can be a great clean energy carrier - yet great are also their costs and associated risks," says lead author Falko Ueckerdt from the Potsdam Institute for Climate Impact Research (PIK). "Fuels based on hydrogen as a universal climate solution might be a bit of false promise. While they're wonderfully versatile, it should not be expected that they broadly replace fossil fuels. Hydrogen-based fuels will likely be scarce and not competitive for at least another decade. Betting on their wide-ranging use would likely increase fossil fuel dependency: if we cling to combustion technologies and hope to feed them with hydrogen-based fuels, and these turn out to be too costly and scarce, then we will end up further burning oil and gas and emit greenhouse gases. This could endanger short- and long-term climate targets."

Prioritizing to applications like aviation and steel productions

"We should hence prioritize those precious hydrogen-based fuels to applications for which they are indispensable: long-distance aviation, feedstocks in chemical production, steel production and potentially some high-temperature industrial processes," says Ueckerdt. "These are sectors and applications that we can hardly electrify directly." The researchers identify a "merit-order of hydrogen and e-fuel demand": a priorization of where to use these new fuels.

So-called green hydrogen is produced through a process called electrolysis. To crack the stable H2O water molecules into Hydrogen and Oxygen, a lot of electricity is needed. The hydrogen can then be used to synthesize hydrocarbon fuels by adding carbon from CO2. The resulting electro-fuels or e-fuels are easier to store and transport than electricity or pure hydrogen. "Most importantly, e-fuels can be burned in conventional combustion processes and engines and thus directly substitute fossil fuels," says Gunnar Luderer, co-author of the paper. "However, given their limited availability, it would be wrong to think that fossils can be fully replaced this way."

Driving a car with hydrogen-based fuels needs five times more energy than a battery-electric car

"We are currently far from 100% renewable electricity - so making efficient use of it is key. However, if we use hydrogen-based fuels instead of direct electrification alternatives, two to fourteen times the amount of electricity generation is needed, depending on the application and the respective technologies," says co-author Romain Sacchi from the Paul Scherrer Institute. "Efficiency losses happen both on the supply side, in the production process of the hydrogen-based fuels, and on the demand side - a combustion engine wastes a lot more energy than an electrical one."

"Low energy efficiencies cause a fragile climate effectiveness," says Sacchi. "If produced with the current electricity mixes, hydrogen-based fuels would increase - not decrease - greenhouse gas emissions. For the German electricity mix in 2018, using hydrogen-based fuels in cars, trucks or planes would produce about three to four times more greenhouse gas emissions than using fossil fuel." In contrast, electric cars or trucks cause greenhouse-gas emissions that are comparable to or lower than those of diesel or gasoline cars already based on today's electricity mixes in most countries, the researchers show based on a full cradle-to-grave life-cycle analysis that includes also those emission associated with the battery production.

"Only for truly renewable-based power systems do hydrogen-based fuels become an effective means to help stabilize our climate", says co-author Jordan Everall. "Hydrogen-based fuels thus clearly require building up loads of additional renewable energy production facilities."

Greenhouse gas abatement costs of hydrogen-based fuels are currently around 1000 Euro per ton CO2

Even if assuming 100% renewable electricity, the costs of avoiding one ton of CO2 emissions by using hydrogen-based fuels would currently be 800 Euro for liquid and 1200 Euro for gaseous fuels, the researchers calculated. This is much higher than current CO2 prices for instance in the European Emissions Trading Scheme, which currently are below 50 Euro per ton. However, if there is continued technological progress driven by CO2 prices as well as subsidies and investments into hydrogen and related industries, by 2050 these CO2 abatement costs could drop to roughly 20 Euro for liquid and 270 Euro for gaseous e-fuels.

Hence, with increasing CO2 prices hydrogen-based fuels could become cost competitive probably by 2040. This is too late for those sectors where direct electrification alternatives exist, given the urgency of greenhouse gas emissions reductions to stabilize our climate.

Carbon pricing is needed to make hydrogen-based fuels competitive

"Despite the uncertainties about future costs, hydrogen-based fuels have the potential to become a backstop technology for replacing all remaining fossil fuels around 2040-50. However, the realization hinges on substantial large-scale policy support and in fact subsidies for about two decades before business cases might be secured solely by increasing carbon pricing," says Falko Ueckerdt. "An overall policy strategy could rest on two pillars: First, broad technology support to foster innovation and initial scale-up including direct electrification. Second, substantial carbon pricing and an energy tax reform that together create a level-playing field for all technologies and thus a sensible balance between direct and indirect electrification."

"The long term vision of hydrogen-based fuels is promising," says Gunnar Luderer. "Tapping into the huge wind and solar energy potential of the global sun belts, e-fuels can be globally traded and thus resolve renewable energy bottlenecks in densely populated countries such as Japan or in Europe. However, as international and national climate targets require immediate emission reductions, from a climate perspective direct electrification should come first to assure a safe future for all."

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Article: Falko Ueckerdt, Christian Bauer, Alois Dirnaichner, Jordan Everall, Romain Sacchi, Gunnar Luderer (2021): Potential and risks of hydrogen-based e-fuels in climate change mitigation. Nature Climate Change [DOI:10.1038/s41558-021-01032-7]

 

Men with chest pain receive faster, more medical attention than women

Women with possible heart attack wait longer and undergo less testing, study finds

AMERICAN COLLEGE OF CARDIOLOGY

Research News

 

Among younger adults visiting the emergency department for chest pain, women may be getting the short end of the stick. Compared with men of similar age, women were triaged less urgently, waited longer to be seen, and were less likely to undergo basic tests or be hospitalized or admitted for observation to diagnose a heart attack, according to new research being presented at the American College of Cardiology's 70th Annual Scientific Session.

The study is the first to examine emergency room management of chest pain specifically among younger adults (age 18-55 years). Heart disease is the leading cause of death in women and is becoming more common in younger adults. About one-third of women who were hospitalized for a heart attack in the past two decades were under the age of 55, a proportion that has grown in recent years.

"Women should trust their instincts," said Darcy Banco, MD, an internal medicine resident at NYU Langone Health and the study's lead author. "Women should seek care right away if they experience new chest discomfort, difficulty breathing, nausea, vomiting, fatigue, sweating or back pain, as these could all be signs of a heart attack. The most important thing a woman can do is to seek medical care if she is worried and to ask specific questions of her doctor."

Chest discomfort is the most common symptom of a heart attack in both men and women, but research shows that women can have a broader range of accompanying symptoms that may not initially be recognized as a sign of a heart attack. Chest discomfort caused by a heart attack can be perceived as pain, pressure, tightness or another uncomfortable sensation.

The study is based on data collected by the National Hospital Ambulatory Medical Care Survey between 2014-2018. Researchers extrapolated the data to represent an estimated 29 million emergency department visits for chest pain in the U.S. among adults aged 18-55; women comprised nearly 57% of those visits.

Researchers found that women reporting chest pain were equally likely to arrive at the hospital by ambulance but significantly less likely than men to be triaged as emergent. On average, women waited about 11 minutes longer to be evaluated by a clinician. Women were also significantly less likely to undergo an electrocardiogram (EKG), the standard initial test used to diagnose a heart attack, or to receive cardiac monitoring or be seen by a consultant, such as a cardiologist.

Medical guidelines recommend that all patients with possible heart attack symptoms receive an EKG within 10 minutes of arrival in the emergency department to minimize the time to treatment.

"Time is very important when you're treating heart attacks," Banco said. "The longer people wait, the worse their outcomes can be."

The study did not examine the reasons why women with chest pain were treated differently than men. Banco suggested that pre-conceived notions of risk--rather than overt discrimination--likely play a role. Historically, heart attacks have been most common in older men, and clinicians may be less likely to suspect a heart attack among patients outside of that demographic. Banco suggested clinicians should appreciate that younger women represent a growing portion of heart attack patients.

"We, as health care providers, should continue to learn about how best to triage and diagnose patients with heart attacks, particularly among those who have historically been under-diagnosed or under-treated," Banco said. "We are learning that heart attacks take many forms. We need to continue to raise awareness and make sure all patients are diagnosed and treated properly, even if they're not the 'classic' demographic for a heart attack. [This knowledge] will help us improve care for all."

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Banco will present the study, "Sex Differences in Evaluation and Management of Young Adults Presenting to the Emergency Department with Chest Pain," on Saturday, May 15, at 9:30 a.m. ET / 13:30 UTC.

To learn more about women and heart disease, visit CardioSmart.org/women.

ACC.21 will take place May 15-17 virtually, bringing together cardiologists and cardiovascular specialists from around the world to share the newest discoveries in treatment and prevention. Follow @ACCinTouch, @ACCMediaCenter and #ACC21 for the latest news from the meeting.

The American College of Cardiology envisions a world where innovation and knowledge optimize cardiovascular care and outcomes. As the professional home for the entire cardiovascular care team, the mission of the College and its 54,000 members is to transform cardiovascular care and to improve heart health. The ACC bestows credentials upon cardiovascular professionals who meet stringent qualifications and leads in the formation of health policy, standards and guidelines. The College also provides professional medical education, disseminates cardiovascular research through its world-renowned JACC Journals, operates national registries to measure and improve care, and offers cardiovascular accreditation to hospitals and institutions. For more, visit ACC.org.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases

High-risk, disadvantaged groups face barriers to preventing spread of COVID-19

Researchers urge greater focus on ensuring access to vaccines and precautionary measures

AMERICAN COLLEGE OF CARDIOLOGY

Research News

 

Social factors such as education, financial stability, food security and the neighborhood where someone resides were strongly correlated with whether or not individuals with heart disease adopted measures to prevent the spread of COVID-19, including wearing masks and working from home, according to a study presented at the American College of Cardiology's 70th Annual Scientific Session. The researchers say the findings draw attention to longstanding challenges related to social determinants of health.

"Unless we look at COVID-19 through the lens of social determinants of health, we may not optimize our yield from interventions, and we might not be reaching the group of individuals who need these interventions the most," said Kobina Hagan, MD, a postdoctoral fellow at Houston Methodist Research Institute and the study's lead author.

The research is based on data from the COVID-19 Household Impact Survey, which assessed COVID-19 preventive strategies along with health and sociodemographic factors among more than 25,000 U.S. adults. The researchers analyzed responses from just over 2,000 survey respondents who reported a history of heart disease, heart attack or stroke. According to the U.S. Centers for Disease Control and Prevention, heart disease increases the risk of severe illness from COVID-19. The researchers grouped survey respondents into quartiles reflecting social risk factors based on income and financial security, employment, education, health insurance status, food insecurity and neighborhood quality.

The largest gap was seen in the degree to which respondents reported having flexibility in their work arrangements--defined as being able to work from home or cancel or postpone work activities. Compared to those with the most favorable social risk profile, those with the greatest social adversity were 46% less likely to report flexibility at work. Individuals with the greatest social adversity were also 31% less likely to engage in all social distancing measures (canceling or postponing social activities and avoiding crowded public places, restaurants and contact with high-risk people) and 17% less likely to engage in all personal protective measures (wearing a face mask, washing hands and keeping a 6-foot distance from those outside their household) compared to those with the most favorable social risk profile. These differences remained significant even after accounting for demographics and comorbidities.

The study was conducted before COVID-19 vaccines were available, at a time when public health experts primarily recommended social distancing and other measures to slow the disease's spread. However, similar trends are likely at play in the context of vaccine access, researchers said.

"I think we are repeating the same mistakes and expecting better results," Hagan said. "I hope we can come to a point where we as a society take social disparities into account in our decision making. We have to prioritize these socially disadvantaged individuals in our public policy programs, including vaccine delivery, to reduce the disparities in COVID-19 risk and outcomes."

Although the survey did not assess the reasons why respondents did or did not adopt COVID-19 mitigation measures, Hagan said many of the factors reflect circumstances that are often outside of a person's control, such as their ability to work from home. For measures that involve more personal choice, he suggested that low health literacy may play a role in the lower uptake of mitigation measures among disadvantaged groups.

"We as a society have ignored all the disparities and inequities that were happening during calmer times, even in cardiovascular disease," Hagan said. "2020 was a time when we could no longer ignore the disparities. We need to focus on holistic strategies to effectively fight this pandemic and ensure those not afforded the privilege of personal protection, social distancing and work flexibilities are prioritized with vaccine outreach to avoid further compounding existing health inequalities."

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For resources on managing heart disease and COVID-19, visit CardioSmart.org/coronavirus.

This study will be simultaneously published in Circulation: Cardiovascular Quality & Outcomes.

Hagan will present the study, "Social Determinants of Health Disparities for COVID-19 Mitigation Measures Among Adults with Cardiovascular Disease in the United States," on Saturday, May 15, at 9:30 a.m. ET / 13:30 p.m. UTC.

ACC.21 will take place May 15-17 virtually, bringing together cardiologists and cardiovascular specialists from around the world to share the newest discoveries in treatment and prevention. Follow @ACCinTouch, @ACCMediaCenter and #ACC21 for the latest news from the meeting.

The American College of Cardiology envisions a world where innovation and knowledge optimize cardiovascular care and outcomes. As the professional home for the entire cardiovascular care team, the mission of the College and its 54,000 members is to transform cardiovascular care and to improve heart health. The ACC bestows credentials upon cardiovascular professionals who meet stringent qualifications and leads in the formation of health policy, standards and guidelines. The College also provides professional medical education, disseminates cardiovascular research through its world-renowned JACC Journals, operates national registries to measure and improve care, and offers cardiovascular accreditation to hospitals and institutions. For more, visit ACC.org.

 

Achieving high COVID-19 vaccine coverage levels by summer can prevent millions of cases

New study finds if the United States vaccinates half its population by the summer vs fall, 5.8 million cases could be prevented and $7.8 billion in societal costs could be saved

CUNY GRADUATE SCHOOL OF PUBLIC HEALTH AND HEALTH POLICY

Research News

 

(MAY 6, 2021) New York, NY - With around 30 percent of the U.S. population now fully vaccinated, the rate of daily vaccinations has started to slow, raising concerns that greater efforts and investments may be needed to reach higher coverage levels. A study published in the Journal of Infectious Diseases on May 6 shows the lives, hospitalizations, and costs that can be saved by even relatively small increases in vaccination coverage and reaching higher vaccination coverage levels sooner (e.g., by the end of the summer versus fall/winter).

The study was led by researchers from PHICOR (Public Health Informatics, Computational, and Operations Research) at CUNY Graduate School of Public Health & Health Policy, the National School of Tropical Medicine at Baylor College of Medicine, and Johns Hopkins Center for Health Security. The team developed a computer simulation model of the entire U.S. and the spread of the COVID-19 coronavirus throughout the country. Using the model, the team could simulate vaccinating different proportions of the population at different rates with different types of COVID-19 vaccines. Like real people, each of these virtual people could become infected with the virus and develop different symptoms over time and, depending upon the severity of those symptoms, visit clinics, emergency departments, or hospitals. These in turn would have associated costs, allowing the tracking of various medical costs and productivity losses.

The study showed that going from a 30 percent vaccination coverage to a 40 percent coverage could save 24.3 million cases and $33.1 billion in direct medical costs and productivity losses. Going from a 50 percent to 70 percent coverage could save 9.5 million cases and 10.8 billion in direct medical costs and productivity losses.

In fact, even relatively small increases in vaccine coverage can prevent thousands of cases and lives and hundreds of millions in costs. For example, results from the model showed each 1 percent increase between 40 and 50 percent of the U.S. population being vaccinated by the fall can prevent 1.6 million cases, 60,190 hospitalizations, and 7,100 deaths and save $674.2 million in direct medical costs and $1.5 billion in productivity losses. Each 1 percent increase between 50 and 70 percent can prevent 473,900 cases, 17,600 hospitalizations, 2,000 deaths, and 537 million in direct medical costs and productivity losses.

The study also emphasized the importance of reaching higher coverage levels as soon as possible. For example, speeding up vaccinations to reach a 50 percent coverage by July 2021 instead of October 2021 could save an additional 5.8 million cases, 215,790 hospitalizations, 26,370 deaths, $3.5 billion in direct medical costs, and $4.3 billion in productivity losses.

Results suggested that getting as many people fully vaccinated as possible before the early winter would be particularly important. The model incorporated changes in the transmission of the virus that occurred with the changing seasons in 2020, when surges occurred during the winter months, and projected what may happen in 2021. For example, when 50 percent of the U.S. population is vaccinated by October 2021 instead of the end of December 2021, 6.6 million cases, 252,260 hospitalizations, 29,380 deaths, $4.0 billion direct medical costs, and $8.0 billion productivity losses were saved.

"The results of this study can give policymakers, community leaders, and other decision makers a sense of how much can be invested into vaccinating those who may be harder to get vaccinated," explained Sarah Bartsch, MPH, the study's lead author and project director for PHICOR. "Such investments may end up paying for themselves. For example, the potential cost savings exceed the $1.5 billion Biden Administration community outreach and media campaign. Our results show that increasing total vaccination coverage by just one percent could cover the costs of this effort."

"The longer it takes to reach higher vaccination coverage levels and herd immunity thresholds, the more the virus can spread," said Bruce Y Lee, senior author of the study, executive director of PHICOR, and CUNY SPH professor. "It may be particularly important to reach higher coverage levels before the late fall to prevent another winter surge."

Additionally, the study showed how increasing vaccination coverage levels was more valuable than using vaccines with higher effectiveness. For example, we found that achieving a 70 percent coverage with a 70 percent effective vaccine can save 2.1 million cases and 5.5 billion in medical costs and productivity losses compared to achieving a 50 percent coverage with a 90 percent effective vaccine over the same period. This shows the value of using all Covid-19 vaccines that are available to get more people vaccinated as soon as possible, rather than focusing only on those with the highest effectiveness. Moreover, as more contagious variants circulate, potentially decreasing the effectiveness of the existing Covid-19 vaccines, this can help address concerns about continuing with the existing vaccines or waiting for an updated version.

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Media contact:

Sarah Rebbert
Sarah.Rebbert18@gmail.com

About CUNY SPH

The CUNY Graduate School of Public Health and Health Policy is committed to teaching, research, and service that creates a healthier New York City and helps promote equitable, efficient, and evidence-based solutions to pressing health problems facing cities around the world. Follow @CUNYSPH for updates.

About PHICOR

Since 2007, PHICOR has been developing computational methods, models, and tools to help decision makers better understand and address complex systems in health and public health. Follow @PHICORTeam for upda

Independent evolutionary origins of vertebrate dentitions, according to latest study

UNIVERSITY OF BRISTOL

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IMAGE: SIDE AND ORAL VIEWS OF A VIRTUAL MODEL OF THE ISCHNACANTHID ACANTHODIAN JAW SHOWING THE TOOTH-ROWS AND RECONSTRUCTION OF THE TOOTH REPLACEMENT. view more 

CREDIT: MARTIN RÜCKLIN, NATURALIS BIODIVERSITY CENTER

The origins of a pretty smile have long been sought in the fearsome jaws of living sharks which have been considered living fossils reflecting the ancestral condition for vertebrate tooth development and inference of its evolution. However, this view ignores real fossils which more accurately reflect the nature of ancient ancestors.

New research led by the University of Bristol and the Naturalis Biodiversity Center published in Nature Ecology and Evolution reveals that the dentitions of living shark relatives are entirely unrepresentative of the last shared ancestor of jawed vertebrates.

The study reveals that while teeth evolved once, complex dentitions have been gained and lost many times in evolutionary history and tooth replacement in living sharks is not the best model in the search for therapeutic solutions to human dental pathologies.

Lead author Martin Rücklin from Naturalis Biodiversity Center in Leiden, The Netherlands said: "We used high energy x-rays at the TOMCAT beamline of the Swiss Light Source at the Paul Scherrer Institut in Switzerland, to study tooth and jaw structure and development among shark ancestors. These ischnacanthid acanthodians possessed marginal dentitions composed of multiple, successional tooth rows, that are quite unlike the tooth whorls that occur in front of the jaw in acanthodians and across the jaws of crown-chondrichthyans."

Co-author Professor Philip Donoghue from the University of Bristol's School of Earth Sciences said: "Dentitions of vertebrates are characterized by an organised arrangement to enable occlusion and efficient feeding over the lifetime of an animal. This organisation and pattering of teeth is thought to originate in a universal development mechanism, the dental lamina, seen in sharks. The condition we see in the successional tooth rows cannot be explained by this mechanism."

Co-author Benedict King from Naturalis Biodiversity Center said: "Using state of the art probabilistic ancestral state estimation methods, we build on this discovery to show that teeth existed in the crown-ancestor of gnathostomes, whereas complex dentitions, tooth whorls, a dental lamina and coordinated replacement, have all evolved independently and been lost several times in the early evolution of jawed vertebrates."

This work was supported by the Dutch Research Council NWO (Vidi grant), the Natural Environment Research Council, the Paul Scherrer Institut, EU Horizon2020 and the Naturalis Biodiversity Center.

Paper

'Acanthodian dental development and the origin of gnathostome dentitions' by Martin Rücklin, Benedict King, John A. Cunningham, Zerina Johanson, Federica Marone and Philip C. J. Donoghue in Nature Ecology & Evolution

Open source tool can help identify gerrymandering in voting maps

WASHINGTON STATE UNIVERSITY

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IMAGE: VISUALIZATION OF SAMPLED COUNTY-PRESERVING VIRGINIA CONGRESSIONAL VOTING DISTRICTS, CREATED WITH THE RECOM METHOD IN GERRYCHAIN. view more 

CREDIT: DARYL DEFORD, WASHINGTON STATE UNIVERSITY

PULLMAN, Wash. -- With state legislatures nationwide preparing for the once-a-decade redrawing of voting districts, a research team has developed a better computational method to help identify improper gerrymandering designed to favor specific candidates or political parties.

In an article in the Harvard Data Science Review, the researchers describe the improved mathematical methodology of an open source tool called GerryChain. The tool can help observers detect gerrymandering in a voting district plan by creating a pool, or ensemble, of alternate maps that also meet legal voting criteria. This map ensemble can show if the proposed plan is an extreme outlier--one that is very unusual from the norm of plans generated without bias, and therefore, likely to be drawn with partisan goals in mind.

An earlier version of GerryChain was used to analyze maps proposed to remedy the Virginia House of Delegates districts that a federal court ruled in 2018 were unconstitutional racial gerrymanders. The updated tool will likely play a role in the upcoming redistricting using new census data.

"We wanted to build an open-source software tool and make that available to people interested in reform, especially in states where there are skewed baselines," said Daryl DeFord, assistant mathematics professor at Washington State University and a co-lead author on the paper. "It can be an impactful way for people to get involved in this process, particularly going into this year's redistricting cycle where there are going to be a lot of opportunities for pointing out less than optimal behavior."

The GerryChain tool, first created by a team led by DeFord as a part of the 2018 Voting Rights Data Institute, has already been downloaded 20,000 times. The new paper, authored by Deford along with Moon Duchin of Tufts University and Justin Solomon of the Massachusetts Institute of Technology, focuses on how the mathematical and computational models implemented in GerryChain can be used to put proposed voting districting plans into context by creating large samples of alternative valid plans for comparison. These alternate plans are often used when a voting plan is challenged in court as being unfair as well as to analyze potential impacts of redistricting reform.

For instance, the enacted 2010 House of Delegates plan in Virginia had 12 voting districts with a Black voting age population at or above 55%. By comparing that plan against an ensemble of alternate plans that all fit the legal criteria, advocates showed that map was an extreme outlier of what was possible. In other words, it was likely drawn intentionally to "pack" some districts with a Black voter population to "crack" other districts, breaking the influence of those voters.

One of the biggest challenges to creating voting maps are the sheer number of possibilities, DeFord said. Many states like Virginia have hundreds of thousands of census blocks. They also have many rules and goals for structuring voting districts: such as keeping them geographically contiguous and compact with units like counties and cities intact. Many states also want to protect "communities of interest" an often undefined term, but the federal Voting Rights Act explicitly aims to protect minority voters, since historically, gerrymanders have sought to weaken the effect of their vote. In addition, multiple states require that voting maps be drawn with an attempt at political neutrality.

Even with all these rules, voting maps can still be drawn in a myriad of different ways.

"There are more feasible plans in a lot of states than there are molecules in the universe," Deford said. "That's why you want this kind of mathematical tool."

Since the advent of computers, models have provided the ability to make an array of maps. Before the current version of Gerrychain, many models used a data method called a "Flip walk" to create alternatives, which involves changing just one assignment at time, such as a precinct or census block. Every change has a ripple effect on other districts, resulting in a different map.

The tool developed by DeFord and his colleagues uses a method called a spanning tree recombination or "ReCom" for short. To create an alternative voting map, the method involves taking two districts, merging them together before splitting them apart again in a different way. This creates a greater change with multiple voting blocks changing at a time.

The computational tool can create many alternative voting plans within a matter of hours or days, and it is freely available for use by voting reform groups or anyone who has knowledge of Python, the data software behind it.

The authors emphasize, however, that computers alone shouldn't create the voting plan that is ultimately adopted for use. Rather the ensemble method provides a tool for analyzing baselines and evaluating potential alternatives.

"This is not some sort of magic black box where you push the button, and you get a collection of perfect plans," said Deford. "It really requires serious engagement with social scientists and legal scholars. Because the rules are written and implemented by people, this is a fundamentally human process."

CAPTION

Visualization of sampled population-shifted Washington Congressional districts, created with the ReCom method in Gerrychain.

CREDIT

Daryl DeFord, Washington State University

CAPTION

Visualization of sampled Pennsylvania Congressional districts, created with the ReCom method in Gerrychain.

CREDIT

Daryl DeFord, Washington State University