Sunday, November 13, 2022

Researchers cook up a new way to remove microplastics from water


Peer-Reviewed Publication

PRINCETON UNIVERSITY, ENGINEERING SCHOOL

Egg white protein aerogel microscopy image 

IMAGE: THE STRUCTURE OF THE AEROGEL IS FORMED BY GRAPHENE SHEETS STRETCHED ACROSS CARBON FIBER NETWORKS. view more 

CREDIT: SHAHARYAR WANI

Researchers at Princeton Engineering have found a way to turn your breakfast food into a new material that can cheaply remove salt and microplastics from seawater.

The researchers used egg whites to create an aerogel, a lightweight and porous material that can be used in many types of applications, including water filtration, energy storage, and sound and thermal insulation. Craig Arnold, the Susan Dod Brown Professor of Mechanical and Aerospace Engineering and vice dean of innovation at Princeton, works with his lab to create new materials, including aerogels, for engineering applications.

One day, sitting in a faculty meeting, he had an idea.

“I was sitting there, staring at the bread in my sandwich,” said Arnold. “And I thought to myself, this is exactly the kind of structure that we need.” So he asked his lab group to make different bread recipes mixed with carbon to see if they could recreate the aerogel structure he was looking for. None of them worked quite right initially, so the team kept eliminating ingredients as they tested, until eventually only egg whites remained.

“We started with a more complex system,” Arnold said, “and we just kept reducing, reducing, reducing, until we got down to the core of what it was. It was the proteins in the egg whites that were leading to the structures that we needed.”

Egg whites are a complex system of almost pure protein that — when freeze-dried and heated to 900 degrees Celsius in an environment without oxygen — create a structure of interconnected strands of carbon fibers and sheets of graphene. In a paper published Aug. 24 in Materials Today, Arnold and his coauthors showed that the resulting material can remove salt and microplastics from seawater with 98% and 99% efficiency, respectively.

“The egg whites even worked if they were fried on the stove first, or whipped,” said Sehmus Ozden, first author on the paper. Ozden is a former postdoctoral research associate at the Princeton Center for Complex Materials and now a scientist at Aramco Research Center. While regular store-bought egg whites were used in initial tests, Ozden said, other similar commercially available proteins produced the same results.

“Eggs are cool because we can all connect to them and they are easy to get, but you want to be careful about competing against the food cycle,” said Arnold. Because other proteins also worked, the material can potentially be produced in large quantities relatively cheaply and without impacting the food supply. One next step for the researchers, Ozden noted, is refining the fabrication process so it can be used in water purification on a larger scale.

If this challenge can be solved, the material has significant benefits because it is inexpensive to produce, energy-efficient to use and highly effective. “Activated carbon is one of the cheapest materials used for water purification. We compared our results with activated carbon, and it’s much better,” said Ozden. Compared with reverse osmosis, which requires significant energy input and excess water for operation, this filtration process requires only gravity to operate and wastes no water.

While Arnold sees water purity as a “major grand challenge,” that is not the only potential application for this material. He is also exploring other uses related to energy storage and insulation.

The research included contributions from the departments of chemical and biological engineering and geosciences at Princeton and elsewhere. “It’s one thing to make something in the lab,” said Arnold, “and it’s another thing to understand why and how.” Collaborators who helped answer the why and how questions included professors Rodney Priestley and A. James Link from chemical and biological engineering, who helped identify the transformation mechanism of the egg white proteins at the molecular level. Princeton colleagues in geosciences assisted with measurements of water filtration.

Susanna Monti of the Institute for Chemistry of Organometallic Compounds and Valentina Tozzi from Instituto Nanoscienze and NEST-Scuola Normale Superiore created the theoretical simulations that revealed the transformation of egg white proteins into the aerogel.

The article, “Egg protein derived ultralightweight hybrid monolithic aerogel for water purification,” was published in the journal Materials Today. Besides Arnold, Monti, Ozden, Priestley, Link and Tozzi, authors include Nikita Dutta, a former graduate student in mechanical and aerospace engineering who is now at the National Renewable Energy Laboratory; Stefania Gill, John Higgins and Nick Caggiano of Princeton University; and Nicola Pugno of the University of Trento and Queen Mary University of London. Support was provided in part by the Princeton Center for Complex Materials and the U.S. National Science Foundation.

Amid food and climate crises, investing in sustainable food cold chains crucial: UN

More than 3 billion people can’t afford a healthy diet; Lack of effective refrigeration directly results in the loss of 526 million tonnes of food production - 12% of global total; Developing countries could save 144 million tons of food annually

Reports and Proceedings

UNITED NATIONS ENVIRONMENT PROGRAMME

UN: Food cold chains report 

IMAGE: THE UN REPORT ‘SUSTAINABLE FOOD COLD CHAINS: OPPORTUNITIES, CHALLENGES AND THE WAY FORWARD’ EMPHASIZES THE NEED FOR ROBUST, SUSTAINABLE COLD CHAINS TO MAINTAIN THE QUALITY, NUTRITIONAL VALUE AND SAFETY OF FOOD, AND TO REDUCE LOSSES, OFFERING CASE STUDIES AND SOLUTIONS TO THE CHALLENGE. view more 

CREDIT: UNEP/FAO

As food insecurity and global warming rise, governments, international development partners and industry should invest in sustainable food cold chains to decrease hunger, provide livelihoods to communities, and adapt to climate change, the UN said today.

Launched today at the 27th Climate Change Conference (COP 27), the Sustainable Food Cold Chains report, from the UN Environment Programme (UNEP) and the Food and Agriculture Organization of the United Nations (FAO), finds that food cold chains are critical to meeting the challenge of feeding an additional two billion people by 2050 and harnessing rural communities’ resilience, while avoiding increased greenhouse gas emissions.

The report (at http://bit.ly/3A3dP8z) was developed in the framework of the UNEP-led Cool Coalition in partnership with FAO, the Ozone Secretariat, UNEP OzonAction Programme, and the Climate and Clean Air Coalition. 

“At a time when the international community must act to address the climate and food crises, sustainable food cold chains can make a massive difference,” said Inger Andersen, Executive Director of UNEP. “They allow us to reduce food loss, improve food security, slow greenhouse gas emissions, create jobs, reduce poverty and build resilience – all in one fell swoop.”

Food insecurity on the rise

The number of people affected by hunger in the world rose to 828 million in 2021, a year-on-year rise of 46 million. 

Almost 3.1 billion people could not afford a healthy diet in 2020, up 112 million from 2019, as the economic impacts of the Covid pandemic drove up inflation. This year, meanwhile, the conflict in Ukraine has raised the prices of basic grains threatening food security.

All of this comes while an estimated 14% of all food produced for human consumption is lost before it reaches the consumer. The lack of an effective cold chain to maintain the quality, nutritional value and safety of food is one of the major contributors (12% of total loss). 

According to the report, developing countries could save 144 million tonnes of food annually if they reached the same level of food cold chain infrastructure as developed countries. 

As post-harvest food loss reduces the income of 470 million small-scale farmers by 15%, mainly in developing countries investing in sustainable food cold chains would help lift these farm families out of poverty. 

Climate impact

The food cold chain has serious implications for climate change and the environment. Emissions from food loss and waste due to lack of refrigeration totalled an estimated 1 gigatonne of carbon dioxide (CO2) equivalent in 2017 – about 2% of total global greenhouse gas emissions.

In particular, it contributes to emissions of methane, a potent but short-lived climate pollutant. Taking action now would contribute to reducing atmospheric concentrations of methane this   decade.   

Overall, the food cold chain is responsible for around 4% of total global greenhouse gas emissions – when emissions from cold chain technologies and food loss caused by lack of refrigeration are included.

Lost food also damages the natural world by driving unnecessary conversion of land for agricultural purposes and use of resources such as water, fossil fuels and energy.

Reducing food loss and waste could make a positive impact on climate change, but only if new cooling-related infrastructure is designed to use gases with low global warming potential, be energy efficient and run on renewable energy.

The adoption of the Kigali Amendment to the Montreal Protocol and the Rome Declaration on “the contribution of the Montreal Protocol to sustainable cold chain development for food waste reduction” provide a unique opportunity to accelerate the deployment of sustainable food cold chains.

Progress being made

Projects around the world show that sustainable food cold chains are already making a difference. In India, a food cold chain pilot project reduced losses of kiwi fruit by 76% while reducing emissions through the expansion of use of refrigerated transport. 

In Nigeria, a project to install 54 operational ColdHubs prevented the spoilage of 42,024 tonnes of food and increased the household income of 5,240 small-scale farmers, retailers and wholesalers by 50%.

But these projects, among many other illustrative case studies in the new report, are still the exception rather than the norm.

Recommendations for decision makers

To expand sustainable food cold chains globally, the report makes a series of recommendations for governments and stakeholders, including:

  • Take a holistic systems approach to food cold chain provision, recognizing that the provision of cooling technologies alone is not enough.
  • Quantify and benchmark the energy use and greenhouse gas emissions in existing food cold chains and identify opportunities for reductions. 
  • Collaborate and undertake food cold chain needs assessments and develop costed and sequenced National Cooling Action Plans, backed with specific actions and financing.
  • Implement and enforce ambitious minimum efficiency standards, and monitoring and enforcement to prevent illegal imports of inefficient food cold chain equipment and refrigerants.
  • Run large-scale system demonstrations to show positive impacts of sustainable cold chains, and how interventions can create sustainable and resilient solutions for scaling.
  • Institute multidisciplinary centres for food cold chain development at the national or regional level.

About the United Nations Environment Programme (UNEP)

UNEP is the leading global voice on the environment. It provides leadership and encourages partnership in caring for the environment by inspiring, informing and enabling nations and peoples to improve their quality of life without compromising that of future generations.

About the Food and Agriculture Organization (FAO)

FAO is a specialized agency of the United Nations that leads international efforts to defeat hunger. Its goal is to achieve food security for all and make sure that people have regular access to enough high-quality food to lead active healthy lives. With over 194-Member Nations, FAO works in over 130 countries worldwide.

About the Cool Coalition 

The Cool Coalition is a global multi-stakeholder network government, cities, international organizations, businesses, finance, academia, and civil society groups committed to a rapid global transition to efficient and climate-friendly cooling. The Coalition is one of the official outcomes and “Transformation Initiatives” put forward by the Executive Office of the Secretary-General for the UN Climate Action Summit. The Coalition’s Secretariat is hosted by the United Nations Environment Programme.

About the Climate and Clean Air Coalition 

The Climate and Clean Air Coalition is a voluntary partnership of governments, intergovernmental organizations, businesses, scientific institutions and civil society organizations committed to improving air quality and protecting the climate through actions to reduce short-lived climate pollutants, including methane, black carbon, tropospheric ozone, and hydrofluorocarbons (HFCs). The Coalition’s Secretariat is hosted by the United Nations Environment Programme.

Earth-sun distance dramatically alters seasons in the equatorial Pacific in a 22,000-year cycle

An unrecognized effect boosts or diminishes the Pacific cold tongue, likely impacting El Niño/La Niña events and North American weather

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - BERKELEY

Pacific cold tongue 

IMAGE: A TEMPERATURE MAP OF THE PACIFIC OCEAN FOR DECEMBER 1993 SHOWING A COLD (BLUE) TONGUE OF SURFACE WATER STRETCHING WESTWARD ALONG THE EQUATOR FROM THE COAST OF SOUTH AMERICA. THE TEMPERATURE AND EXTENT OF THE COLD TONGUE CHANGES WITH THE SEASONS, BUT NEW CLIMATE SIMULATIONS SHOW THAT THE ANNUAL CHANGE IN EARTH’S DISTANCE FROM THE SUN ALSO AFFECTS THE COLD TONGUE SEASONAL CYCLE. THIS INFLUENCES EL NIÑO CONDITIONS THAT IMPACT WEATHER IN NORTH AMERICA AND GLOBALLY. view more 

CREDIT: JOHN CHIANG, UC BERKELEY

Weather and climate modelers understand pretty well how seasonal winds and ocean currents affect El Niño patterns in the eastern equatorial Pacific Ocean, impacting weather across the United States and sometimes worldwide.

But new computer simulations show that one driver of annual weather cycles in that region — in particular, a cold tongue of surface waters stretching westward along the equator from the coast of South America — has gone unrecognized: the changing distance between Earth and the sun.

The cold tongue, in turn, influences the El Niño-Southern Oscillation (ENSO), which impacts weather in California, much of North America, and often globally.

The Earth-sun distance slowly varies over the course of the year because Earth’s orbit is slightly elliptical. Currently, at its closest approach — perihelion — Earth is about 3 million miles closer to the sun than at its farthest point, or aphelion. As a result, sunlight is about 7% more intense at perihelion than at aphelion.

Research led by the University of California, Berkeley, demonstrates that the slight yearly change in our distance from the sun can have a large effect on the annual cycle of the cold tongue. This is distinct from the effect of Earth’s axial tilt on the seasons, which is currently understood to cause the annual cycle of the cold tongue.

Because the period of the annual cycle arising from the tilt and distance effects are slightly different, their combined effects vary over time, said lead researcher John Chiang, UC Berkeley professor of geography.

“The curious thing is that the annual cycle from the distance effect is slightly longer than that for tilt — around 25 minutes, currently — so over a span of about 11,000 years, the two annual cycles go from being in phase to out of phase, and the net seasonality undergoes a remarkable change, as a result,” Chiang said.

Chiang noted that the distance effect is already incorporated into climate models — though its effect on the equatorial Pacific was not recognized until now — and his findings will not alter weather predictions or climate projections. But the 22,000-year phase cycle may have had long-term, historical effects. Earth’s orbital precession is known to have affected the timing of the ice ages, for example.

The distance effect — and its 22,000-year variation — also may affect other weather systems on Earth. The ENSO, which also originates in the equatorial Pacific, is likely affected because its workings are closely tied to the seasonal cycle of the cold tongue.

“Theory tells us that the seasonal cycle of the cold tongue plays a key role in the development and termination of ENSO events,” said Alyssa Atwood, a former UC Berkeley postdoctoral fellow who is now an assistant professor at Florida State University in Tallahassee. “Because of this, many of ENSO’s key characteristics are synced to the seasonal cycle.”

For example, ENSO events tend to peak during Northern Hemisphere winters, she said, and they don’t typically persist beyond northern or boreal spring months, which scientists refer to as the “spring predictability barrier.” Because of these linkages, it is reasonable to expect that the distance effect could also have a major impact on ENSO — something that should be examined in future studies.

“Very little attention has been paid to the cold tongue seasonal cycle because most people think it's solved. There's nothing interesting there,” Chiang said. “What this research shows is that it's not solved. There's still a mystery there. Our result also begs the question whether other regions on Earth may also have a significant distance effect contribution to their seasonal cycle.”

“We learn in science classes as early as grade school that the seasons are caused by the tilt of Earth’s axis,” added co-author Anthony Broccoli of Rutgers University. “This is certainly true and has been well understood for centuries. Although the effect of the Earth-sun distance has also been recognized, our study indicates that this ‘distance effect’ may be a more important effect on climate than had been recognized previously.”

Chiang, Atwood and Broccoli and their colleagues reported their findings today in the journal Nature  

Two distinct yearly cycles affect Pacific cold tongue

The main driver of global weather changes is seasonal change. Earth’s equator is tilted relative to its orbit around the sun, so the Northern and Southern hemispheres are illuminated differently. When the sun shines directly overhead in the north, it’s warmer in the north and colder in the south, and vice versa.

These yearly changes have major effects on the Pacific equatorial trade winds, which blow from southeast to northwest across the south and equatorial Pacific and push surface waters westward, causing upwelling of cold water along the equator that creates a tongue of cold surface water that stretches from Ecuador across the Pacific — almost one-quarter the circumference of the planet.

The yearly hemispheric changes in seasonal temperature alters the strength of the trades, and thus cause a yearly cycle in the temperature of the cold tongue. This, in turn, has a major influence on ENSO, which typically peaks during Northern Hemisphere winter.

The occurrence of El Niño — or its opposite, La Niña — helps determines whether California and the West Coast will have a wet or dry winter, but also whether the Midwest and parts of Asia will have rain or drought.

“In studying past climates, much effort has been dedicated to trying to understand if variability in the tropical Pacific Ocean — that is, the El Niño/La Niña cycle — has changed in the past,” Broccoli said. “We chose to focus instead on the yearly cycle of ocean temperatures in the eastern Pacific cold tongue. Our study found that the timing of perihelion — that is, the point at which the earth is closest to the sun — has an important influence on climate in the tropical Pacific."

In 2015, Broccoli, co-director of the Rutgers Climate Institute, along with his then-graduate student Michael Erb, employed a computer climate model to show that the distance changes caused by Earth’s elliptical orbit dramatically altered the cold tongue yearly cycle. But climate modelers mostly ignored the result, Chiang said.

“Our field is focused on El Niño, and we thought that the seasonal cycle was solved. But then we realized that the result by Erb and Broccoli challenged this assumption,” he said.

Chiang and his colleagues, including Broccoli and Atwood, examined similar simulations using four different climate models and confirmed the result. But the team went further to show how the distance effect works.

Earth’s ‘marine’ and ‘continental’ hemispheres

The key distinction is that changes in the sun’s distance from Earth don’t affect the Northern and Southern hemispheres differently, which is what gives rise to the seasonal effect due to Earth’s axial tilt. Instead, they warm the eastern “continental hemisphere” dominated by the North and South American and African and Eurasian landmasses, more than it warms the Western Hemisphere — what he calls the marine hemisphere, because it is dominated by the Pacific Ocean.

“The traditional way of thinking about monsoons is that the Northern Hemisphere warms up relative to the Southern Hemisphere, generating winds onto land that bring monsoon rains,” Chiang said. “But here, we’re actually talking about east-west, not north-south, temperature differences that cause the winds. The distance effect is operating through the same mechanism as the seasonal monsoon rains, but the wind changes are coming from this east-west monsoon.”

The winds generated by this differential heating of the marine and continental hemispheres alter the yearly variation of the easterly trades in the western equatorial Pacific, and thereby the cold tongue.

“When Earth is closest to the sun, these winds are strong. In the offseason, when the sun is at its furthest, these winds become weak,” Chiang said. “Those wind changes are then propagated to the Eastern Pacific through the thermocline, and basically it drives an annual cycle of the cold tongue, as a result.”

Today, Chiang said, the distance effect on the cold tongue is about one-third the strength of the tilt effect, and they enhance one another, leading to a strong annual cycle of the cold tongue. About 6,000 years ago, they canceled one another, yielding a muted annual cycle of the cold tongue. In the past, when Earth’s orbit was more elliptical, the distance effect on the cold tongue would have been larger and could have led to a more complete cancellation when out of phase.

Though Chiang and his colleagues did not examine the effect of such a cancellation, this would potentially have had a worldwide effect on weather patterns.

Chiang emphasized that the distance effect on climate, while clear in climate model simulations, would not be evident from observations because it cannot be readily distinguished from the tilt effect.

“This study is purely model based. So, it is a prediction,” he said. “But this behavior is reproduced by a number of different models, at least four. And what we did in this study is to explain why this happens. And in the process, we've discovered another annual cycle of the cold tongue that's driven by Earth's eccentricity.”

Atwood noted that, unlike the robust changes to the cold tongue seasonal cycle, changes to ENSO tend to be model-dependent.

“While ENSO remains a challenge for climate models, we can look beyond climate model simulations to the paleoclimate record to investigate the connection between changes in the annual cycle of the cold tongue and ENSO in the past,” she said. “To date, paleoclimate records from the tropical Pacific have largely been interpreted in terms of past changes in ENSO, but our study underscores the need to separate changes in the cold tongue annual cycle from changes in ENSO.”

Chiang’s colleagues, in addition to Broccoli and Atwood, are Daniel Vimont of the University of Wisconsin in Madison; former UC Berkeley undergraduate Paul Nicknish, now a graduate student at the Massachusetts Institute of Technology; William Roberts of Northumbria University in Newcastle-upon-Tyne in the United Kingdom; and Clay Tabor of the University of Connecticut in Storrs. Chiang conducted part of the research while on sabbatical at the Research Institute for Environmental Changes of the Academia Sinica in Taipei, Taiwan.

Turning concrete into a clean energy source

UTA-led partnership aims to manufacture concrete that captures carbon emissions

Grant and Award Announcement

UNIVERSITY OF TEXAS AT ARLINGTON

Maria Konstas-Gdoutos 

IMAGE: MARIA KONSTAS-GDOUTOS view more 

CREDIT: UT ARLINGTON

Concrete is the most widely used manufactured material worldwide—and one of the largest contributors to greenhouse gas emissions, accounting for at least 8% of global energy-related carbon dioxide emissions.

Maria Konsta-Gdoutos, a University of Texas at Arlington civil engineering professor and associate director of the Center for Advanced Construction Materials (CACM), is leading an international effort to decarbonize concrete production and promote its use as a renewable energy generator.

“We will pioneer TE-CO2NCRETE, a thermoelectric carbon-neutral concrete, that will exhibit a high carbon dioxide uptake potential and storage capacity,” Konsta-Gdoutos said. “Engineering the nanostructure of concrete also will allow the material to capture thermal energy from the surroundings and convert it into usable electrical energy, leading to the development of a novel technology for renewable electricity and higher efficiency power source.” 

A $1.5 million National Science Foundation grant is supporting this effort, which also involves another U.S. university and five European institutions. The U.S. partner is the University of Wisconsin-Milwaukee’s Concrete Sustainability and Resilience Center, which is known for experimental research on design, multiscale characterization and implementation of sustainable multifunctional concrete utilizing carbon-based waste byproducts and graphene-based nanomaterials. International partners include the French National Center for Scientific Research, which is an expert on atomistic simulation techniques useful in renewable energy research; the Technical Universities in Dresden and Berlin, Germany; and the Politecnico di Torino in Torino, Italy.

Other stakeholders include the Portland Cement Association, a leading research and market organization serving cement manufacturers, and the American Concrete Institute. Both are actively engaged to accelerate and advance solutions to reach carbon neutrality, Konsta-Gdoutos said.

The aim of the partnership is to advance technological know-how for net zero carbon concrete at a global scale, picking up the pace set by the Paris Agreement to reduce greenhouse gas emissions 52% by 2030.

Konsta-Gdoutos said all partners are authorities in carbonated construction materials and energy-autonomous building materials and are equipped in handling various parts of the project. Further, CACM’s labs contain a sub-10-nanometer imaging/mapping NanoIR AFM spectrometer, the only one at a university in the United States.

Melanie Sattler, professor and interim chair of the Department of Civil Engineering, said the international collaboration connects research to the workforce.

“The partnership’s readiness to scale up and establish long-lasting bonds of international research are extensive,” Sattler said. “I could see industry stakeholders and national and international agencies become meaningful partners of the workforce connection.”

University of Missouri is helping the aviation industry go “green”

Using part of a $12.8 million grant from the U.S. Department of Energy, MU researchers are working with an interdisciplinary group to optimize green energy for aviation use.

Grant and Award Announcement

UNIVERSITY OF MISSOURI-COLUMBIA

Plant samples 

IMAGE: GABRIEL LEMES JORGE, A POSTDOCTORAL FELLOW AT MU, CHECKS ON PLANT SAMPLES IN JAY J. THELEN'S LAB AT THE CHRISTOPHER S. BOND LIFE SCIENCES CENTER. view more 

CREDIT: UNIVERSITY OF MISSOURI

While biodiesel and ethanol are two forms of biofuel used to power today’s cars and trucks, one area of the transportation sector that’s still developing a viable biofuel solution is the aviation industry. Now, an interdisciplinary team of researchers from across the United States, including the University of Missouri, is working to develop a sustainable “green energy” source of biofuel — an energy source commonly produced from vegetable oil — as an alternative to the petroleum-based fossil fuel widely used in the aviation industry.

The team, using a $12.8 million grant from the U.S. Department of Energy (DOE), will explore how two cover crops — plants grown to capture carbon from the Earth’s atmosphere to help reduce greenhouse gas emissions — called camelina and pennycress could be genetically modified to produce higher overall quantities of a specialty seed oil. The team’s goal is to mass-produce a vegetable oil capable of being used as a biofuel for aviation purposes, according to Jay J. Thelen, a professor of biochemistry in the College of Agriculture, Food and Natural Resources, who is also an investigator in the Christopher S. Bond Life Sciences Center.

“We’re trying to increase the overall amount of seed oil produced by both crops, as well as changing the oil composition from 18 to 10 carbons, which makes the oil more fluid for use in the aviation industry,” Thelen said.

Edgar Cahoon, the George W. Holmes Professor of Biochemistry at the University of Nebraska-Lincoln and lead researcher on the grant, is exploring how to take genes from the cuphea plant — known for their medium-chain oil producing traits — and using biotechnology to transfer them to camelina and pennycress. Additionally, using $2.7 million of the $12.8 million grant, MU’s team is taking three of the Thelen lab’s patented approaches for improving overall oil content in plant seeds and applying them to Cahoon’s existing research on this topic.

MU’s team hopes to figure out why camelina and pennycress are not producing the optimal amount of seed oil after cuphea’s medium-chain oil producing traits are introduced to both plants through genetic engineering.

“When we move genes from cuphea into camelina or pennycress, we’re going to do large-scale transcriptomics and proteomics to try to understand how the plant is responding to this new gene and see where the bottlenecks lie that Cahoon’s team is experiencing,” Thelen said. “With that knowledge we can complete the design, build, test, learn cycle in order to incrementally raise the levels of the medium-chain fatty acids in camelina or pennycress until we meet the optimal level.”

To do this, MU’s team is using advanced proteomics technologies, including sophisticated state-of-the-art mass spectrometry instrumentation located in both Thelen’s lab and the Charles W. Gehrke Proteomics Center at MU. The group will also use cutting-edge biotechnology approaches to gain knowledge about how the plants are responding to the genetic engineering, Thelen said.

“Leveraging my lab’s expertise in both discovery and targeted proteomics will provide us with the basic knowledge we need to help understand why engineering high levels of medium-chain oils in camelina and pennycress has been elusive so far,” Thelen said.

This research creates a large amount of data to be analyzed, so internationally renowned bioinformatics researchers Dong Xu from the MU College of Engineering and Trupti Joshi from the MU School of Medicine are joining Thelen to assist him with that part of the project. MU’s team will add the information they collect to a related project by Xu which involves building an online database on the topic of metabolic engineering of oilseed plants.

Since cover crops can be planted during the non-growing season and can also be grown in soils with less-than-ideal planting conditions, Thelen hopes the team’s work could provide farmers across the U.S. with an additional option to earn a profit beyond the traditional growing and harvesting seasons.    

“At the moment, these cover crops [camelina and pennycress] are mostly planted to earn federal carbon credits, but they are not harvested by farmers,” Thelen said.

In addition to MU and the University of Nebraska-Lincoln, the team includes researchers from the Donald Danforth Plant Science Center, Kansas State University, Montana State University, University of Colorado-Boulder, University of Minnesota and Washington State University.  

The grant was awarded under the DOE program Biosystems Design to Enable Safe Production of Next-generation Biofuels, Bioproducts and Biomaterials.

Editor’s Note: Joshi is the translational bioinformatics faculty lead for NextGen Biomedical Informatics (BMI) and the MU School of Medicine. Dong Xu is a Curators’ Distinguished Professor in the Department of Electrical Engineering and Computer Science. Both have faculty appointments in the Christopher S. Bond Life Sciences Center and the Institute for Data Science and Informatics at MU.

The world will probably warm beyond the 1.5-degree limit. But peak warming can be curbed


While warming is likely to surpass the limit set by the 2015 Paris Agreement, just how much remains a question

Peer-Reviewed Publication

DOE/PACIFIC NORTHWEST NATIONAL LABORATORY

RICHLAND, Wash.—The world’s current climate pledges are insufficient to keep the goal of the 2015 Paris Agreement firmly within grasp. Global warming will likely surpass the 1.5-degree Celsius limit. We are going to overshoot.

But countries can curb time spent in a warmer world by adopting more ambitious climate pledges and decarbonizing faster, according to new research led by scientists at the Department of Energy’s Pacific Northwest National Laboratory, the University of Maryland and the U.S. Environmental Protection Agency. Doing so, they warn, is the only way to minimize the overshoot.

While exceeding the 1.5-degree limit appears inevitable, the researchers chart several potential courses in which the overshoot period is shortened, in some cases by decades. The study published today in the journal Nature Climate Change, during the 2022 United Nations Climate Change Conference, also known as COP27, held in Sharm El Sheikh, Egypt.

“Let’s face it. We are going to breach the 1.5 degrees limit in the next couple of decades,” said corresponding author and PNNL scientist Haewon McJeon. “That means we’ll go up to 1.6 or 1.7 degrees or above, and we’ll need to bring it back down to 1.5. But how fast we can bring it down is key.”

Every second shaved off the overshoot translates to less time courting the most harmful consequences of global warming, from extreme weather to rising sea levels. Forgoing or delaying more ambitious goals could lead to “irreversible and adverse consequences for human and natural systems,” said lead author Gokul Iyer, a scientist alongside McJeon at the Joint Global Change Research Institute, a partnership between PNNL and the University of Maryland.

“Moving fast means hitting net-zero pledges sooner, decarbonizing faster, and striking more ambitious emissions targets,” said Iyer. “Every little bit helps, and you need a combination of all of it. But our results show that the most important thing is doing it early. Doing it now, really.”

During COP26 in 2021, the same research team found that the then updated pledges could substantially increase the chance of limiting warming to 2 degrees Celsius over pre-industrial levels. In their new paper, the authors take an additional step in answering the question of how to move the needle from 2 to 1.5 degrees.

“The 2021 pledges don't add up to anywhere near 1.5 degrees—we are forced to focus on the overshoot,” said PNNL scientist Yang Ou, who co-led the study. “Here, we're trying to provide scientific support to help answer the question: What type of ratcheting mechanism would get us back down and below 1.5 degrees? That's the motivation behind this paper.”

The Paths Forward

The authors model scenarios—27 emissions pathways in total, each ranging in ambition—to explore what degree of warming would likely follow which course of action. At a base level, the authors assume that countries will meet their emissions pledges and long-term strategies on schedule.

In more ambitious scenarios, the authors model how much warming is limited when countries decarbonize faster and advance the dates of their net-zero pledges. Their results underscore the significance of “ratcheting near-term ambition,” which entails rapid reductions in carbon dioxide emissions from all sectors of the energy system, immediately and through 2030.

If countries uphold their nationally determined contributions through 2030 and follow a two percent minimum decarbonization rate, for example, global carbon dioxide levels would not reach net zero this century.

Taking the most ambitious path outlined, however, could bring net-zero carbon dioxide emissions by 2057. Such a path, the authors write, is marked by “rapid transformations throughout the global energy system” and the scaling up of “low-carbon technologies like renewables, nuclear energy, as well as carbon capture and storage.”

“The technologies that help us get to zero emissions include renewables, hydrogen, electric cars, and so on. Of course those are important players,” said Iyer. “Another important piece of the puzzle is the technologies that can remove carbon dioxide from the atmosphere, like direct air capture or nature-based solutions.”

The most ambitious scenarios outlined in their work are meant to be illustrative of the pathways on offer. But the central takeaway remains clear throughout all modeled scenarios: if 1.5 degrees is to be reattained sooner after we warm past it, more ambitious climate pledges must come.

This work was supported by the U.S. Environmental Protection Agency.

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Dementia prevalence is declining among older Americans, study finds

Study also finds decreases in disparities based on race and sex

Peer-Reviewed Publication

RAND CORPORATION

The prevalence of dementia in the U.S. is declining among people over age 65, dropping 3.7 percentage points from 2000 to 2016, according to a new RAND Corporation study.

The age-adjusted prevalence of dementia declined from 12.2% of people over age 65 in 2000 to 8.5% of people over age 65 in 2016 – a nearly one-third drop from the 2000 level. The prevalence of dementia decreased over the entire period, but the rate of decline was more rapid between 2000 and 2004.

Differences in the prevalence of dementia between Black men and white men narrowed, with the prevalence of dementia dropping by 7.3 percentage points among Black men as compared to 2.7 percentage points among white men.

The findings are published in the latest edition of the journal Proceedings of the National Academy of Sciences.

“The reasons for the decline in the prevalence of dementia are not certain, but this trend is good news for older Americans and the systems that support them,” said Péter Hudomiet, the study's lead author and an economist at RAND, a nonprofit research organization. “This decline may help reduce the expected strain on families, nursing homes and other support systems as the American population ages.”

Michael D. Hurd and Susann Rohwedder of RAND are co-authors of the study.

The prevalence of dementia was higher among women than men over the entire period, but the difference shrank between 2000 and 2016. Among men, the prevalence of dementia decreased by 3.2 percentage points from 10.2% to 7.0%. The decrease was larger among women -- 3.9 percentage points from 13.6% to 9.7%.

In 2021, about 6.2 million U.S. adults aged 65 or older lived with dementia. Because age is the strongest risk factor for dementia, it has been predicted that increasing life expectancies will substantially increase the prevalence of Alzheimer’s disease and related dementias from about 50 million to 150 million worldwide by 2050.

However, there is growing evidence that age-adjusted dementia prevalence has been declining in developed countries, possibly because of rising levels of education, a reduction in smoking, and better treatment of key cardiovascular risk factors such as high blood pressure.

Any change in these age-specific rates has important implications for projected prevalence and associated costs, such as payments for nursing care by households, insurance companies, and the government.

The new RAND study employs a novel model to assess cognitive status based on a broad set of cognitive measures elicited from more than 21,000 people who participate in the national Health and Retirement Study, a large population-representative survey that has been fielded for more than two decades.

The model increases the precision of dementia classification by using the longitudinal dimension of the data. Importantly for the study of inequality, the model is constructed to ensure the dementia classification is calibrated within population subgroups and, therefore, it is equipped to produce accurate estimates of dementia prevalence by age, sex, education, race and ethnicity, and by a measure of lifetime earnings.

The RAND study found that education was an important factor that contributed, in a statistical sense, to the reduction in dementia, explaining about 40% of the reduction in dementia prevalence among men and 20% of the reduction among women.

The fraction of college-educated men in the study increased from 21.5% in 2000 to 33.7% in 2016, and the fraction of college-educated women increased from 12.3% to 23% over this period.

Trends in the level of education differ across demographic groups, which may affect inequalities in dementia in the future. For example, while women traditionally had lower levels of education than men, among younger generations, women are more educated. While racial and ethnic minority groups still have lower education levels than non-Hispanic White individuals, the gaps across racial and ethnic groups have shrunk.

“Closing the education gap across racial and ethnic groups may be a powerful tool to reduce health inequalities in general and dementia inequalities in particular, an important public health policy goal,” Hudomiet said.

The age-adjusted prevalence of dementia tended to be higher among racial and ethnic minority individuals, both among men and women. However, among men, the difference in the prevalence between non-Hispanic Black and White individuals narrowed while it remained stable among women. Among non-Hispanic White men, the prevalence of dementia decreased from 9.3% to 6.6%. Among non-Hispanic Black men, the rate fell from 17.2% to 9.9%.

Support for the study, which is titled “Trends in Inequalities in the Prevalence of Dementia in the U.S.,” was provided by a grant from National Institute on Aging.

The RAND Social and Economic Well-Being division seeks to actively improve the health, social and economic well-being of populations and communities throughout the world.

Globally, the number of pregnancies at risk from malaria infection fell between 2000 and 2020 - but in sub-Saharan Africa, it rose to 52.4 million despite control initiatives

Peer-Reviewed Publication

PLOS

Women are at risk of severe adverse pregnancy outcomes attributable to Plasmodium spp. infection in malaria-endemic areas. 

IMAGE: WOMEN ARE AT RISK OF SEVERE ADVERSE PREGNANCY OUTCOMES ATTRIBUTABLE TO PLASMODIUM SPP. INFECTION IN MALARIA-ENDEMIC AREAS. view more 

CREDIT: RYUTARO TSUKATA, PEXELS, CC0 (HTTPS://CREATIVECOMMONS.ORG/PUBLICDOMAIN/ZERO/1.0/)

Globally, the number of pregnancies at risk from malaria infection fell between 2000 and 2020 - but in sub-Saharan Africa, it rose to 52.4 million despite control initiatives

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Article URL: https://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0001061

Article Title: Global estimates of pregnancies at risk of Plasmodium falciparum and Plasmodium vivax infection in 2020 and changes in risk patterns since 2000

Author Countries: UK, Democratic Republic of the Congo, Australia

Funding: WorldPop work was funded in part by the Wellcome Trust (grant number: 204613/Z/16/Z), the UK Foreign, Commonwealth and Development Office, and, by the Bill and Melinda Gates Foundation (grant number INV-007594). Matt Cairns: Matthew E Cairns is supported by a Sir Henry Dale Fellowship jointly funded by the 15 Wellcome Trust and the Royal Society (Grant Number 220658/Z/20/Z). Georgia R Gore-Langton is supported by an MRC PhD studentship (MR/N013638/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.