Depression and stress could dampen efficacy of COVID-19 vaccines

Interventions and health behavior changes could boost

ASSOCIATION FOR PSYCHOLOGICAL SCIENCE

Research News

Decades of research show that depression, stress, loneliness, and poor health behaviors can weaken the body's immune system and lower the effectiveness of certain vaccines. A new report accepted for publication in Perspectives on Psychological Science suggests that the same may be true for the new COVID-19 vaccines that are in development and the early stages of global distribution. Fortunately, it may be possible to reduce these negative effects with simple steps like exercise and sleep.

Vaccines are among the safest and most effective advances in medical history, protecting society from a wide range of otherwise devastating diseases, including smallpox and polio. The key to their success, however, is ensuring that a critical percentage of the population is effectively vaccinated to achieve so-called herd immunity.

Even though rigorous testing has shown that the COVID-19 vaccines approved for distribution in the United States are highly effective at producing a robust immune response, not everyone will immediately gain their full benefit. Environmental factors, as well as an individual's genetics and physical and mental health, can weaken the body's immune system, slowing the response to a vaccine.

This is particularly troubling as the novel coronavirus continues to rage across the world, trigging a concurrent mental health crisis as people deal with isolation, economic stressors, and uncertainty about the future. These challenges are the same factors that have been previously shown to weaken vaccine efficacy, particularly among the elderly.

"In addition to the physical toll of COVID-19, the pandemic has an equally troubling mental health component, causing anxiety and depression, among many other related problems. Emotional stressors like these can affect a person's immune system, impairing their ability to ward off infections," said Annelise Madison, a researcher at The Ohio State University and lead author on the paper. "Our new study sheds light on vaccine efficacy and how health behaviors and emotional stressors can alter the body's ability to develop an immune response. The trouble is that the pandemic in and of itself could be amplifying these risk factors."

Vaccines work by challenging the immune system. Within hours of a vaccination, there is an innate, general immune response on the cellular level as the body begins to recognize a potential biological threat. This frontline response by the immune system is eventually aided by the production of antibodies, which target specific pathogens. It is the continued production of antibodies that helps to determine how effective a vaccine is at conferring long-term protection.

"In our research, we focus most heavily on the antibody response, though it is just one facet of the adaptive immune system's response," said Janice Kiecolt-Glaser, director of the Institute for Behavioral Medicine Research at The Ohio State University and senior author on the paper.

The good news, according to the researchers, is that the COVID-19 vaccines already in circulation are approximately 95% effective. Even so, these psychological and behavioral factors can lengthen the amount of time it takes to develop immunity and can shorten the duration of immunity.

"The thing that excites me is that some of these factors are modifiable," said Kiecolt-Glaser. "It's possible to do some simple things to maximize the vaccine's initial effectiveness."

Based on prior research, one strategy the researchers suggest is to engage in vigorous exercise and get a good night's sleep in the 24 hours before vaccination so that your immune system is operating at peak performance. This may help ensure that the best and strongest immune response happens as quickly as possible.

"Prior research suggests that psychological and behavioral interventions can improve vaccine responsiveness. Even shorter-term interventions can be effective," said Madison. "Therefore, now is the time to identify those at risk for a poor immune response and intervene on these risk factors."

###

Reference: Madison, A. A., Shrout, M. R., Renna, M. E., Kiecolt-Glaser, J. K. (2021). Psychological and behavioral predictors of vaccine efficacy: Considerations for COVID-19. Advance: Social Sciences & Humanities.

Additional information in APS Research Topic on Vaccination.

Studying chaos with one of the world's fastest cameras

CALIFORNIA INSTITUTE OF TECHNOLOGY

Research News

 

IMAGE: A VIDEO RECORDED WITH A CAMERA SHOOTING AT ONE BILLION FRAMES PER SECOND SHOWS HOW TWO PULSES OF LASER LIGHT TAKE DIFFERING PATHS WHILE REFLECTING WITHIN A CHAOTIC OPTICAL CAVITY. view more 

CREDIT: CALTECH

There are things in life that can be predicted reasonably well. The tides rise and fall. The moon waxes and wanes. A billiard ball bounces around a table according to orderly geometry.

And then there are things that defy easy prediction: The hurricane that changes direction without warning. The splashing of water in a fountain. The graceful disorder of branches growing from a tree.

These phenomena and others like them can be described as chaotic systems, and are notable for exhibiting behavior that is predictable at first, but grows increasingly random with time.

Because of the large role that chaotic systems play in the world around us, scientists and mathematicians have long sought to better understand them. Now, Caltech's Lihong Wang, the Bren Professor in the Andrew and Peggy Cherng department of Medical Engineering, has developed a new tool that might help in this quest.

In the latest issue of Science Advances, Wang describes how he has used an ultrafast camera of his own design that recorded video at one billion frames per second to observe the movement of laser light in a chamber specially designed to induce chaotic reflections.

"Some cavities are non-chaotic, so the path the light takes is predictable," Wang says. But in the current work, he and his colleagues have used that ultrafast camera as a tool to study a chaotic cavity, "in which the light takes a different path every time we repeat the experiment."

The camera makes use of a technology called compressed ultrafast photography (CUP), which Wang has demonstrated in other research to be capable of speeds as fast as 70 trillion frames per second. The speed at which a CUP camera takes video makes it capable of seeing light--the fastest thing in the universe--as it travels.

But CUP cameras have another feature that make them uniquely suited for studying chaotic systems. Unlike a traditional camera that shoots one frame of video at a time, a CUP camera essentially shoots all of its frames at once. This allows the camera to capture the entirety of a laser beam's chaotic path through the chamber all in one go.

That matters because in a chaotic system, the behavior is different every time. If the camera only captured part of the action, the behavior that was not recorded could never be studied, because it would never occur in exactly the same way again. It would be like trying to photograph a bird, but with a camera that can only capture one body part at a time; furthermore, every time the bird landed near you, it would be a different species. Although you could try to assemble all your photos into one composite bird image, that cobbled-together bird would have the beak of a crow, the neck of a stork, the wings of a duck, the tail of a hawk, and the legs of a chicken. Not exactly useful.

Wang says that the ability of his CUP camera to capture the chaotic movement of light may breathe new life into the study of optical chaos, which has applications in physics, communications, and cryptography.

"It was a really hot field some time ago, but it's died down, maybe because we didn't have the tools we needed," he says. "The experimentalists lost interest because they couldn't do the experiments, and the theoreticians lost interest because they couldn't validate their theories experimentally. This was a fun demonstration to show people in that field that they finally have an experimental tool."

###

The paper describing the research, titled "Real-time observation and control of optical chaos," appears in the January 13 issue of Science Advances. Co-authors are Linran Fan, formerly of Caltech, now an assistant professor at Wyant College of Optical Sciences at the University of Arizona; and Xiaodong Yan and Han Wang, of the University of Southern California.

Funding for the research was provided by the Army Research Office Young Investigator Program, the Air Force Office of Scientific Research, the National Science Foundation, and the National Institutes of Health.

NOT FAD DIETS

MIND and Mediterranean diets associated with later onset of Parkinson's disease

UNIVERSITY OF BRITISH COLUMBIA

Research News

 

A new study from UBC researchers suggests a strong correlation between following the MIND and Mediterranean diets and later onset of Parkinson's disease (PD). While researchers have long known of neuroprotective effects of the MIND diet for diseases like Alzheimer's and dementia, this study is the first to suggest a link between this diet and brain health for Parkinson's disease (PD).

The MIND diet combines aspects of two very popular diets, the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet.

"The study shows individuals with Parkinson's disease have a significantly later age of onset if their eating pattern closely aligns with the Mediterranean-type diet. The difference shown in the study was up to 17 years later in women and eight years later in men," says Dr. Silke Appel-Cresswell of the Pacific Parkinson's Research Centre, the Djavad Mowafaghian Centre for Brain Health and the Division of Neurology in the UBC Faculty of Medicine. "There is a lack of medications to prevent or delay Parkinson's disease yet we are optimistic that this new evidence suggests nutrition could potentially delay onset of the disease."

In a study of 176 participants, researchers looked at adherence to these types of diets, characterized by reduced meat intake and a focus on vegetables, fruits, whole grains and healthy fats, and the age of PD onset. They found that close adherence to these diets coincided with later onset of PD in women of up to 17.4 years, and 8.4 years in men. The MIND diet showed a more significant impact on women's health, whereas the Mediterranean diet did for the men. The differences in these two diets are subtle, but could serve as clues to the impacts specific foods and micronutrients may have on brain health.

The different effects of diet adherence between sexes are noteworthy as approximately 60 per cent of those diagnosed with Parkinson's disease are men.

"If we understand the sex differences between the MIND diet and Mediterranean diet then we might better understand the sex differences that drive Parkinson's disease in the first place," says lead researcher Avril Metcalfe-Roach, a PhD student at UBC's Michael Smith Laboratories.

These findings springboard to other research questions that could have significant impacts on the understanding of PD.

"It drives home the connection between the gut and the brain for this disease," says Dr. Brett Finlay, professor in the departments of biochemistry and molecular biology, and microbiology and immunology at UBC. "It also shows it's not just one disease that healthy eating can affect, but several of these cognitive diseases."

The research team plans to further examine the potential connection between the microbiome and its effect on the brain.

"There is so much benefit to eating healthy," says Metcalfe-Roach. "It is in everybody's best interest to try to keep your microbiome healthy, to try and eat a rich variety of plant-based and other healthy foods. This study provides even more evidence for what we already know--that we should be trying to eat healthy and taking care of ourselves."

###

Scientists discover new 'spectacular' bat from West Africa

AMERICAN MUSEUM OF NATURAL HISTORY

Research News

 

IMAGE: MYOTIS NIMBAENSIS, SHOWN HERE, IS A NEW SPECIES OF BAT NAMED FOR THE MOUNTAIN RANGE IN WHICH IT IS FOUND, THE NIMBA MOUNTAINS IN WEST AFRICA. view more 

CREDIT: © BAT CONSERVATION INTERNATIONAL

A group of scientists led by the American Museum of Natural History and Bat Conservation International have discovered a new species of a striking orange and black bat in a mountain range in West Africa. The species, which the researchers expect is likely critically endangered, underscores the importance of sub-Saharan "sky islands" to bat diversity. The species is described today in the journal American Museum Novitates.

"In an age of extinction, a discovery like this offers a glimmer of hope," said Winifred Frick, chief scientist at Bat Conservation International and an associate research professor at the University of California, Santa Cruz. "It's a spectacular animal. It has this bright-orange fur, and because it was so distinct, that led us to realize it was not described before. Discovering a new mammal is rare. It has been a dream of mine since I was a child."

In 2018, Frick and her colleagues at Bat Conservation International and the University of Maroua in Cameroon were in the Nimba Mountains in Guinea conducting field surveys in natural caves and mining tunnels, known as adits, that were built in the 1970s and 1980s and have since been colonized by bats. In collaboration with the local mining company, Société des Mines de Fer de Guinée (SMFG), the scientists are trying to understand which bat species use which adits and at what times of the year. Of particular interest is Lamotte's roundleaf bat, Hipposideros lamottei, which is listed by the International Union for Conservation of Nature (IUCN) as critically endangered and has only ever been recorded in the Nimba Mountains. Much of its known population lives in the adits, which are in different states of collapse and will disappear in time. While surveying for this bat, the researchers found something peculiar--a bat that looked nothing like Lamotte's roundleaf bat and did not match the descriptions of any other species that they knew occurred in the area. Later that night, they called on American Museum of Natural History Curator Nancy Simmons, a bat expert and chair of the Museum's Department of Mammalogy, for help.

"As soon as I looked at it, I agreed that it was something new," said Simmons, the lead author of the paper and Bat Conservation International Board member. "Then began the long path of documentation and gathering all the data needed to show that it's indeed unlike any other known species."

CAPTION

This illustration shows Myotis nimbaensis, a new species of bat found in the Nimba Mountains of West Africa

Through morphological, mor¬phometric, echolocation, and genetic data, including comparative data from collections at the Museum, the Smithsonian National Museum of Natural History, and the British Museum, the scientists described the new species, which they named Myotis nimbaensis ("from Nimba") in recognition of the mountain range in which it is found. A chain of "African sky islands," the Nimba Mountains have peaks rising between 1,600-1,750 meters (about 1 mile) above sea level and are surrounded by drastically different lowland habitats. As such, they are home to exceptional biodiversity, including bats.

"In addition to the Lamotte's roundleaf bat, it's possible Myotis nimbaensis could be the second bat species found only in this particular mountain range," said Jon Flanders, Bat Conservation International's director of endangered species interventions.

This study is part of an ongoing effort critical in helping the Nimba Mountain bats survive. Bat Conservation International and SMFG have already started working together to build new tunnels, reinforced to last for centuries and in habitat away from the mining project, for the Lamotte's roundleaf bat. And although little is known yet about the population and range of Myotis nimbaensis, efforts like this will likely help it as well.

CAPTION

A chain of "African sky islands," the Nimba Mountains in Guinea have peaks rising between 1,600-1,750 meters (about 1 mile) above sea level and are surrounded by drastically different lowland habitats. They are home to exceptional biodiversity, including bats.

CREDIT

© Bat Conservation International

Other authors on the study include Eric Moïse Bakwo Fils from the University of Maroua; Guy Parker, Jamison Suter, and Seinan Bamba from SMFG; Mory Douno from the Ministry of the Environment, Water, and Forests in Guinea; Mamady Kobele Keita from Guinée Ecologie; and Ariadna Morales from the American Museum of Natural History and the Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.

Link to study: http://digitallibrary.amnh.org/handle/2246/7249

ABOUT THE AMERICAN MUSEUM OF NATURAL HISTORY (AMNH)

The American Museum of Natural History, founded in 1869 and currently celebrating its 150th anniversary, is one of the world's preeminent scientific, educational, and cultural institutions. The Museum encompasses more than 40 permanent exhibition halls, including those in the Rose Center for Earth and Space, as well as galleries for temporary exhibitions. The Museum's approximately 200 scientists draw on a world-class research collection of more than 34 million artifacts and specimens, some of which are billions of years old, and on one of the largest natural history libraries in the world. Through its Richard Gilder Graduate School, the Museum grants the Ph.D. degree in Comparative Biology and the Master of Arts in Teaching (MAT) degree, the only such free-standing, degree-granting programs at any museum in the United States. The Museum's website, digital videos, and apps for mobile devices bring its collections, exhibitions, and educational programs to millions around the world. Visit amnh.org for more information.

About Bat Conservation International

Founded in 1982, Bat Conservation International has grown into a global conservation organization dedicated to ending bat extinctions. Working together, our goal is to redefine what is possible in global conservation, through the utilization of cutting-edge tools, technology, and training to create a real, measurable impact. For more information, visit batcon.org.

Pulsed ultraviolet light technology to improve egg safety, help poultry industry

Novel decontamination method can be used with both table and hatching eggs

PENN STATE

Research News

 

IMAGE: LEAD RESEARCHER JOSHUA CASSER OBSERVING AGAR PLATES IN SEARCH OF MICROBIAL GROWTH RETRIEVED FROM THE SURFACE OF AN EGG. view more 

CREDIT: PENN STATE

Pulsed ultraviolet light can be an effective alternative to some of the antimicrobial technologies now used by the poultry industry to kill pathogens on eggshells, according to Penn State researchers, who simulated production conditions to test the technology.

Researcher Paul Patterson, professor of poultry science, College of Agricultural Sciences, suggests the technology has merit for commercial application in the egg industry.

"This study is unique because it scaled-up and applied components of standard egg processing to a conveyor and sanitizing eggs in a commercial setting," he said. "In the absence of water or other chemical sanitizers, this technology has the potential to achieve significant -- equal or greater -- microbial reductions than some currently available technologies."

Every year in the United States, an average of 287 eggs are consumed per person, and more than 14.1 billion eggs are set in hatchery incubators to produce chicks destined for the egg and meat bird industries. By reducing the microbial load on eggs, foodborne illness outbreaks associated with eggs and poultry meat can be reduced while chick health is maintained.

The egg industry currently uses sanitizers and detergents to decontaminate eggs and wash off any physical debris, while low-intensity ultraviolet light has been used as an additional antimicrobial step. However, pulsed ultraviolet light is more effective, explained lead researcher Josh Casser, doctoral candidate in animal science, because it delivers a higher intensity of ultraviolet light to the surface of the eggshell. That results in a greater microbial reduction in a shorter period of time than conventional ultraviolet light treatment.

In this study, the surfaces of shell eggs were inoculated with nonpathogenic bacteria strains used for research and were treated with pulsed ultraviolet light derived from a xenon flashlamp. Eggs were exposed on a modified egg-carrying conveyor that provided complete rotation of eggs under the flashlamp.

The novel conveyor devised for the experiment was instrumental in achieving acceptable decontamination, Casser noted, adding that the xenon flashlamps could be scaled up and customized for any commercial installation.

"As the egg rotates on its long axis along the way, the entire surface of the eggshell is exposed to the pulsed ultraviolet light energy, and the 27 seconds of exposure in our experiment resulted in an acceptable germicidal response," he said. "At three pulses per second, each egg is exposed to nearly 90 pulses, and each pulse has a duration of 360 microseconds -- an extremely short duration pulse."

The researchers, who recently published their results in Poultry Science, found that pulsed ultraviolet light treatment inactivated two different microbial strains, with greater energy resulting in a greater germicidal response.

The study also evaluated the effects of pulsed ultraviolet light treatment of hatching eggs on both embryo and chick growth. Using the same system, four batches of 125 fertile eggs were treated with the same and greater intensities of pulsed ultraviolet light. After processing, eggs were placed in a commercial incubator under normal incubation conditions.

There was no significant effect of the pulsed ultraviolet light treatment on percent fertility, hatchability or hatch. Also, there were no significant effects on post-hatch observations, including chick livability and average bird weight at hatch or at 42 days of age.

"Our research supports the application of pulsed ultraviolet light as an effective antimicrobial intervention for both table and hatching eggs," Cassar said. "If the egg industry embraces pulsed ultraviolet light technology and applies it in its processing operations, food safety would be improved because of the reduced pathogen presence on the surface of the eggs. And that matters because 9% of all foodborne illness in the U.S. is associated with eggs."

The technology is especially promising because it appears to have no negative consequences for the vital hatching-eggs component of the business, even at 10 times the UV-light intensity used in the table egg study, Patterson pointed out. Hatcheries produce the replacement stock for both the egg and broiler flocks of the poultry industry, including turkeys.

"Our research showed that there are no negative effects on hatching eggs and the embryos and chicks that are derived from those treated eggs," he said. "Using pulsed ultraviolet light before incubation in a hatchery setting would improve chick health, would avoid some of the financial constraints caused by poor chick quality resulting from chicks getting sick from early exposure to microbial pathogens, and potentially would improve the food safety of poultry meat."

###

Also involved in the research were Ed Mills, associate professor of meat science; Ali Demirci, professor of agricultural and biological engineering; and Lindsey Bright, undergraduate student in animal science and recipient of a College of Agricultural Sciences Undergraduate Research Award.

The U.S. Department of Agriculture's National Institute of Food and Agriculture partially supported this work. Hy-Line North America supplied the eggs used in this research, and Xenon Corp., of Wilmington, Massachusetts, provided technical assistance with the pulsed ultraviolet light technology.

'Swiss Army knife' catalyst can make natural gas burn cleaner

Lowering the combustion temperature for methane

UNIVERSITY OF ILLINOIS AT CHICAGO

Research News

 

IMAGE: REZA SHAHBAZIAN-YASSAR, PROFESSOR OF MECHANICAL AND INDUSTRIAL ENGINEERING AT THE UIC COLLEGE OF ENGINEERING AND ZHENNAN HUANG, A PH.D. STUDENT IN SHAHBAZIAN-YASSAR'S LAB AND CO-FIRST AUTHOR OF THE PAPER.... view more 

CREDIT: PHOTO: JENNY FONTAINE/UIC

Reza Shahbazian-Yassar, professor of mechanical and industrial engineering at the University of Illinois Chicago.

Shahbazian-Yassar and colleagues facilitated the development of a cutting edge "Swiss Army knife" catalyst made up of 10 different elements - each of which on its own has the ability to reduce the combustion temperature of methane - plus oxygen. This unique catalyst can bring the combustion temperature of methane down by about half - from above 1400 degrees Kelvin down to 600 to 700 degrees Kelvin.

Their findings are reported in the journal Nature Catalysis.

In previously-published research, Shahbazian-Yassar and colleagues demonstrated the ability to create multi-element nanoparticle catalysts, known as high entropy alloys using a unique shock-wave technique. Before this, materials scientists didn't make serious attempts to create nanoparticles out of more than three elements because of the tendency of each elements' atoms to separate from each other and become useless.

Taking advantage of the unique real-time, high-temperature electron microscopy system at UIC, Shahbazian-Yassar's team showed that high entropy nanoparticles made up of 10 metal oxides were highly stable at temperatures up to 1,073 degrees Kelvin and the individual elements were distributed evenly throughout each nanoparticle forming a single, solid-state stable crystalline structure.

Their metal oxide alloy contained various mixtures of transition metals, which are rare-earth elements, and noble metals plus oxygen.

"It is almost impossible to maintain a perfect mix of these elements in a solid phase due to the differences in atomic radius, crystal structure, oxidation potential, and electronic properties of the elements," said Zhennan Huang, a Ph.D. student in Shahbazian-Yassar's lab and co-first author in the paper. "But we were able to show that this is possible."

"Among multiple alloys with multiple elements that we created, the particles made of 10 elements not only were most effective in reducing the combustion point of methane gas but also the most stable at those temperatures," said Shahbazian-Yassar, who is a corresponding author on the paper.

The researchers believe the catalyst could be used to reduce the output of harmful greenhouse gases produced by burning natural gas in individual households, to power turbines and even in cars that run on compressed natural gas.

CAPTION

The elements that make up the metal oxide nanoparticle catalyst

CREDIT

Image: Zhennan Huang

###

Tangyuan Li, Yonggang Yao, Menghao Yang, Jinglong Gao, Alexandra Brozena, Liangbing Hu, Yifei Mo, Glenn Pastel, Miaolun Jiao, Qi Dong, Jiaqi Dai and Shuke Li of the University of Maryland; Pengfei Xie, Kaizhu Zeng, Han Zong and Chao Wang of Johns Hopkins University; Zhenyu Liu and Guofeng Wang of the University of Pittsburgh; Miaofang Chi of Oak Ridge National Laboratory and Jian Luo of the University of California, San Diego, are co-authors on the paper.

Concept for a hybrid-electric plane may reduce aviation's air pollution problem

Proposed design could reduce nitrogen oxide emissions by 95 percent, a new study finds

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Research News

 

At cruising altitude, airplanes emit a steady stream of nitrogen oxides into the atmosphere, where the chemicals can linger to produce ozone and fine particulates. Nitrogen oxides, or NOx, are a major source of air pollution and have been associated with asthma, respiratory disease, and cardiovascular disorders. Previous research has shown that the generation of these chemicals due to global aviation results in 16,000 premature deaths each year.

Now MIT engineers have come up with a concept for airplane propulsion that they estimate would eliminate 95 percent of aviation's NOx emissions, and thereby reduce the number of associated early deaths by 92 percent.

The concept is inspired by emissions-control systems used in ground transportation vehicles. Many heavy-duty diesel trucks today house postcombustion emissions-control systems to reduce the NOx generated by engines. The researchers now propose a similar design for aviation, with an electric twist.

Today's planes are propelled by jet engines anchored beneath each wing. Each engine houses a gas turbine that powers a propeller to move the plane through the air as exhaust from the turbine flows out the back. Due to this configuration, it has not been possible to use emissions-control devices, as they would interfere with the thrust produced by the engines.

In the new hybrid-electric, or "turbo-electric," design, a plane's source of power would still be a conventional gas turbine, but it would be integrated within the plane's cargo hold. Rather than directly powering propellers or fans, the gas turbine would drive a generator, also in the hold, to produce electricity, which would then electrically power the plane's wing-mounted, electrically driven propellers or fans. The emissions produced by the gas turbine would be fed into an emissions-control system, broadly similar to those in diesel vehicles, which would clean the exhaust before ejecting it into the atmosphere.

"This would still be a tremendous engineering challenge, but there aren't fundamental physics limitations," says Steven Barrett, professor of aeronautics and astronautics at MIT. "If you want to get to a net-zero aviation sector, this is a potential way of solving the air pollution part of it, which is significant, and in a way that's technologically quite viable."

The details of the design, including analyses of its potential fuel cost and health impacts, are published today in the journal Energy and Environmental Science. The paper's co-authors are Prakash Prashanth, Raymond Speth, Sebastian Eastham, and Jayant Sabnins, all members of MIT's Laboratory for Aviation and the Environment.

A semi-electrified plan

The seeds for the team's hybrid-electric plane grew out of Barrett and his team's work in investigating the Volkswagen diesel emissions scandal. In 2015, environmental regulators discovered that the car manufacturer had been intentionally manipulating diesel engines to activate onboard emissions-control systems only during lab testing, such that they appeared to meet NOx emissions standards but in fact emitted up to 40 times more NOx in real-world driving conditions.

As he looked into the health impacts of the emissions cheat, Barrett also became familiar with diesel vehicles' emissions-control systems in general. Around the same time, he was also looking into the possibility of engineering large, all-electric aircraft.

"The research that's been done in the last few years shows you could probably electrify smaller aircraft, but for big aircraft, it won't happen anytime soon without pretty major breakthroughs in battery technology," Barrett says. "So I thought, maybe we can take the electric propulsion part from electric aircraft, and the gas turbines that have been around for a long time and are super reliable and very efficient, and combine that with the emissions-control technology that's used in automotive and ground power, to at least enable semielectrified planes."

Flying with zero impact

Before airplane electrification had been seriously considered, it might have been possible to implement a concept such as this, for example as an add-on to the back of jet engines. But this design, Barrett notes, would "kill any stream of thrust" that a jet engine would produce, effectively grounding the design.

Barrett's concept gets around this limitation by separating the thrust-producing propellers or fans from the power-generating gas turbine. The propellers or fans would instead be directly powered by an electric generator, which in turn would be powered by the gas turbine. The exhaust from the gas turbine would be fed into an emissions-control system, which could be folded up, accordion-style, in the plane's cargo hold -- completely isolated from the thrust-producing propellers.

He envisions the bulk of the hybrid-electric system -- gas turbine, electric generator, and emissions control system -- would fit within the belly of a plane, where there can be ample space in many commercial aircraft .

In their new paper, the researchers calculate that if such a hybrid-electric system were implemented on a Boeing 737 or Airbus A320-like aircraft, the extra weight would require about 0.6 percent more fuel to fly the plane.

"This would be many, many times more feasible than what has been proposed for all-electric aircraft," Barrett says. "This design would add some hundreds of kilograms to a plane, as opposed to adding many tons of batteries, which would be over a magnitude of extra weight."

The researchers also calculated the emissions that would be produced by a large aircraft, with and without an emissions control system, and found that the hybrid-electric design would eliminate 95 percent of NOx emissions

If this system were rolled out across all aircraft around the world, they further estimate that 92 percent of pollution-related deaths due to aviation would be avoided. They arrived at this estimate by using a global model to map the flow of aviation emissions through the atmosphere, and calculated how much various populations around the world would be exposed to these emissions. They then converted these exposures to mortalities, or estimates of the number of people who would die as a result of exposure to aviation emissions.

The team is now working on designs for a "zero-impact" airplane that flies without emitting NOx and other chemicals like climate-altering carbon dioxide.

"We need to get to essentially zero net-climate impacts and zero deaths from air pollution," Barrett says. "This current design would effectively eliminate aviation's air pollution problem. We're now working on the climate impact part of it."

###

Written by Jennifer Chu, MIT News Office

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

SolarEV City concept: Building the next urban power and mobility systems

Unlocking the potentials of EV batteries with roof-top PVs for urban decarbonization

NATIONAL INSTITUTE FOR ENVIRONMENTAL STUDIES

Research News

 

Cities have become the focus of global climate mitigation efforts because as they are responsible for 60-70% of energy-related CO2 emissions. As the world is increasingly urbanized, it is crucial to identify cost-effective pathways to decarbonize and enhance the resilience of cities, which ensure the well-being of their dwellers. In this study, we propose a "SolarEV City" concept, in which integrated systems of cities' roof-top photovoltaics and electric vehicles (EVs) supply affordable and dispatchable CO2-free electricity to urban dwellers.

The SolarEV City assumes that 70% of toof-top of cities at maximum are used for PV and all passenger vehciles are converted to EV in cities being used as batteries for PV electricity. We conducted technoeconomic analyses to evaluate the concept in terms of CO2 emission reduction, cost savings, energy suffciency, self-sufficiency, self-consumption for nine Japanese urban areas (Kyoto City, Hiroshima City, Korimaya City, Okayama City, Sapporo City, Sendai City, Niigata City, Kawasaki City, Special districits of Tokyo).

Our analyses indicate that implementations of the concept can meet 53-95 % of electricity demands in nine major Japanese urban areas by 2030 with the use of 70% of roof-top area in the cities. CO2 emission from vehicle use and electricity generation in these areas can be reduced by 54-95% with potential cost savings of 26-41%. High cost-effectiveness and seasonally stable insolation in low latitudes may imply that the concept may be more effective to decarbonize urban environments in emerging economies in low latitudes.

Among several factors, governmental interventions will play a crucial role in realizing such systems, particularly in legislating regulations that enhance penetration of the integrated system of PV and EV and enable formation of decentralized power systems. As bottom-up processes are critical, policy makers, communities, industries, and researchers should work together to build such systems ov

Resilience to climate change?

New study finds octopuses adapting to higher ocean acid levels

UNIVERSITY OF CHICAGO PRESS JOURNALS

Research News

 

IMAGE: THIS EAST PACIFIC RUBY OCTOPUS, OCTOPUS RUBESCENS, WAS PHOTOGRAPHED BY KIRT L. ONTHANK NEAR WHIDBEY ISLAND, WASHINGTON, UNITED STATES. view more 

CREDIT: KIRT L. ONTHANK

With the impact of climate change increasing by the day, scientists are studying the ways in which human behavior contributes to the damage. A recent study at Walla Walla University, by a collaboration of researchers from Walla Walla University and La Sierra University, examined the effects of acidic water on octopuses, potentially bringing new insight into both how our activities impact the world around us, and the way that world is adapting in response.

The study, "Impact of Short- and Long-Term Exposure to Elevated Seawater PCO2 on Metabolic Rate and Hypoxia Tolerance in Octopus rubescens," focused on the metabolic rate of octopuses exposed to water acidified by carbon dioxide, and the changes it made to the animals. CO2 is a key indicator of the growing acidity of our oceans because much of the gas released into the air by humans is dissolving into the seawater.

Initial work in the field focused on the negative effects of ocean acidity: the impaired growth of affected species such as hermit crabs, for example, or reduced survival rates of certain types of fish over time. Adaptability, however, has not received as much attention, particularly when it comes to octopuses and other cephalopods. What studies have been conducted showed conflicting results, particularly when it comes to short-term vs. long-term exposure to increased ocean acidity (OA).

For instance, studies on cuttlefish show no significant change in their metabolism after exposure to increased OA, while squid subjected to the same conditions showed a reduction in aerobic metabolism, indicating reduced oxygen circulation in the subjects.

For purposes of this experiment, researchers used octopus rubescens a small and easily maintained species of octopus common to the west coast of North America. The subjects were exposed to increased CO2-created acidity for a period of 5 weeks. Researchers measured their routine metabolic rate (RMR) with no prior acclimation to the acidic water, and then again at 1 week and at 5 weeks. The subjects' critical oxygen pressure was measured at 5 weeks as well.

Metabolic rates are very telling in such circumstances because most significant physiological changes - such as smaller organs or reduced growth - are reflected in the shift in metabolism. (Changes in physiology are essentially changes in energy use, which can be observed by monitoring metabolism.)

The results demonstrated a surprising amount of adaptability in the subjects, as well as possible causes for data variation in other experiments. The subjects experienced high levels of metabolic change within the first 24 hours of exposure to increased acidity: a departure from earlier studies on different cephalopods, which showed a decrease in metabolic change.

However, when the same subjects were evaluated after one week, their RMR had returned to normal. The normal readings remained after 5 weeks as well, though their ability to function in low oxygen levels suffered in response to the increased acidity.

The results suggest that octopuses may be better able to withstand changes in ocean-acidity levels, which may have long-term bearings on our understanding of climate change. It also marks the first study to compare long-term and short-term effects of increased acid exposure. Further research is needed to clarify the mechanism driving the change in RMR, but the experimental parameters - and the use of octopus rubescens as test subjects - provide an excellent model system for studying the effects of OA on cephalopods.

###

Future too warm for baby sharks

ARC CENTRE OF EXCELLENCE FOR CORAL REEF STUDIES

Research News

 

IMAGE: IN WARMER WATERS, SHARK EMBRYOS GREW FASTER AND USED THEIR YOLK SAC QUICKER, WHICH IS THEIR ONLY SOURCE OF FOOD AS THEY DEVELOP IN THE EGG CASE. THIS LED TO... view more 

CREDIT: M. JOHNSON

New research has found as climate change causes the world's oceans to warm, baby sharks are born smaller, exhausted, undernourished and into environments that are already difficult for them to survive in.

Lead author of the study Carolyn Wheeler is a PhD candidate at the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU) and the University of Massachusetts. She examined the effects of increased temperatures on the growth, development and physiological performance of epaulette sharks--an egg-laying species found only on the Great Barrier Reef. She and her team studied the sharks as embryos and as hatchlings.

"We tested shark embryos in waters up to 31°C," Ms Wheeler said.

"The hotter the conditions, the faster everything happened, which could be a problem for the sharks. The embryos grew faster and used their yolk sac quicker, which is their only source of food as they develop in the egg case. This led to them hatching earlier than usual."

This meant hatchlings were not only smaller, they needed to feed almost straight away--while lacking significant energy.

Co-author Associate Professor Jodie Rummer, also from Coral CoE at JCU, says the waters of the Great Barrier Reef will likely experience summer averages close to or even in excess of 31°C by the end of the century.

Since sharks don't care for their eggs after they are laid, a shark egg must be able to survive unprotected for up to four months. Dr Rummer flags rising ocean temperatures as a major concern for the future of all sharks--both egg-laying and live-bearing species.

"The epaulette shark is known for its resilience to change, even to ocean acidification," Dr Rummer said. "So, if this species can't cope with warming waters then how will other, less tolerant species fare?" she said.

Sharks and the class of animals they belong to, which includes rays and skates, are slow growing. They also don't reproduce that often compared to other fishes. The populations of these creatures are already threatened across the globe.

The study suggests the sharks of the future will be born--or hatch, in this case--not only at a disadvantage but into environments that are already at the warmest they can tolerate.

"The study presents a worrying future given that sharks are already threatened," Ms Wheeler said.

"Sharks are important predators that keep ocean ecosystems healthy. Without predators, whole ecosystems can collapse, which is why we need to keep studying and protecting these creatures."

"Our future ecosystems depend us taking urgent action to limit climate change," Dr Rummer said.

###

The research was a collaborative effort between the Anderson Cabot Center for Ocean Life and the husbandry staff at the New England Aquarium in Boston. The New England Aquarium has a successful breeding program for epaulette sharks.

PAPER

Wheeler C, Rummer J, Bailey B, Lockwood J, Vance S, Mandelman J. (2020). 'Future thermal regimes for epaulette sharks (Hemiscyllium ocellatum): growth and metabolic performance cease to be optimal'. Scientific Reports, 10: 79953. DOI: 10.1038/s41598-020-79953-0