It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Friday, April 23, 2021
Plant provenance influences pollinators
Researchers study the importance of interactions between plants and insects in the restoration of ecosystems
IMAGE: EARTH BUMBLEBEE COVERED WITH POLLEN FROM FIELD SCABIOUS. view more
CREDIT: WWU - PETER LESSMANN
Insect decline is one of the greatest challenges facing our society. As a result of the destruction of many natural habitats, bees, bumblebees, butterflies, beetles and the like find less and less food. As a consequence, they are barely able to fulfil their role as pollinators of wild and cultivated plants. This trend is increasingly noticeable in agricultural regions in particular.
Researchers at the University of Münster have now taken a more detailed look at how the choice of seeds in restoration measures - i.e. the restoration of natural habitats at degraded land - affects how insects benefit from these measures. Here, not only the plant species plays an important role, but so does the geographical provenance of the seeds used - because the provenance influences not only insect diversity but also how often the pollinators visit flowers. The results of the study have been published in the "Journal of Applied Ecology".
Background and methodology
Insects are indispensable for the functioning of ecosystems - and for human survival. They are necessary, for example, for the pollination of many cultivated plants which are, in turn, an essential source of nutrition for humans. In regions characterized by agriculture or in built-up areas with settlements and cities, there are reduced resources available to pollinators. In order to support them in their pollination, flower-rich habitats are created in the landscape, often in the form of wildflower stripes.
When flower stripes or other habitats are created, however, it should be taken into account that plant species are not homogeneous entities, as their populations genetically differ. This differentiation often occurs as a result of population adaptation to their local environment. A brown knapweed, for example, which grows near the sea - where frost is rare - will be less frost-resistant than a brown knapweed which grows in the mountains, where frost is common. The differences can be seen in many plant traits, and some of these differences can influence pollinators, for example the number of flowers or the time when they flower. "Depending on the provenance, some populations flower earlier than others," as Dr. Anna Lampei Bucharová from Münster University's Institute of Landscape Ecology explains, who also lead the study. "When setting up habitats for pollinators, these within-species differences have so far often been neglected," she adds, "and the plants are mostly selected regardless of their provenance. This is why we tested to see whether the provenance of the plants influences pollinators."
The geographical provenance of the seeds plays a key role in this context. In a field experiment, the researchers formed small experimental plant communities which had exactly the same species composition but different provenances. The populations came from the Münster region, from the area around Munich and from greater Frankfurt an der Oder. They then recorded flowering data, observed the pollinators visiting these communities, and compared the frequency and diversity of the pollinators in communities with different provenances.
The researchers discovered that a plant's provenance influences pollinators - both how often the pollinators visit flowers and also the diversity of the insect species. "The effect can be considerable," says Dr. David Ott, co-author of the study. "We observed twice as many visits by pollinators at flowers of one provenance than at flowers of another provenance. The most important parameter driving this is the phenology of the plant's flower - in other words, the temporal sequence of flowering," he adds. The researchers conclude that plants from some provenances started to flower earlier and more intensively than others, and so they presented more flowers and, as a result, interacted more frequently with pollinators.
The results are important both for scientists and for ecological restoration. The researchers are confident that Germany provides good conditions for implementing provenance-based restoration strategies, because regional ecotypes of many species are readily available in the so-called "Regiosaatgut" ("regional seeds") system. This system provides regional seeds for many species for up to 22 regions in Germany. Thus, by selecting the appropriate plant origins, resources for pollinators could be sustainably improved.
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As part of the Paris Agreement, nearly all countries agreed to take steps to limit the average increase in global surface temperature to less than 2 °C, or preferably 1.5 °C, compared with preindustrial levels. Since the Agreement was adopted, however, concerns about global warming suggest that countries should aim for the "preferable" warming limit of 1.5 °C.
What are the implications for China of trying to achieve this lower limit?
Prof. DUAN Hongbo from the University of Chinese Academy of Sciences and Prof. WANG Shouyang from the Academy of Mathematics and Systems Science of the Chinese Academy of Sciences, together with their collaborators, have attempted to answer this question.
Their results were published in an article entitled "Assessing China's efforts to pursue the 1.5°C warming limit," which was published in Science on April 22.
The authors used nine different integrated assessment models (IAMs) to make their evaluation of China's effort to achieve the warming limit of 1.5 °C.
The various models show different emission trajectories for carbon and noncarbon emissions. The majority of the IAMs will achieve near-zero or negative carbon emissions by around 2050, with a range from -0.13 billion tonnes of CO2 (GtCO2) to 2.34 GtCO2 across models. However, one highly consistent finding among all models is that the 1.5°C warming limit requires carbon emissions decrease sharply after 2020.
The researchers discovered that a steep and early drop in carbon emissions reduces dependency on negative emission technologies (NETs), i.e., technologies that capture and sequester carbon. One implication of this finding is that there is a trade-off between substantial early mitigation of carbon emissions and reliance on NETs, which may have uncertain performance. At the same time, the model showing the lowest carbon emissions by 2050 shows the greatest reliance on carbon capture and storage (CCS) technology--suggesting that NETs have an important role in reducing carbon emissions.
Although carbon emissions were an important focus of the study, the researchers also noted that reducing noncarbon emissions is necessary to stay under the warming limit. Specifically, carbon emissions must be reduced by 90%, CH4 emissions by about 71% and N2O emissions by about 52% to achieve the 1.5 °C goal.
The study showed that mitigation challenges differ across sectors, e.g., industry, residential and commercial, transportation, electricity and "other." Among these sectors, industry plays a big role in end-use energy consumption. Therefore, substantial changes in industrial energy use must occur to reach deep decarbonization of the entire economy and realization of the given climate goals. Indeed, a highly consistent finding across all models is that the largest proportion of emission reduction will come from a substantial decline in energy consumption.
The study also highlights the importance of replacing fossil fuels with renewables, a strategy that plays the next most important role in emission reduction behind reducing energy consumption. The study suggests that China needs to decrease its fossil energy consumption (as measured by standard coal equivalent, or Gtce) by about 74% in 2050 in comparison with the no policy scenario.
The researchers estimate that achieving the 1.5 °C goal will involve a loss of GDP in 2050 in the range of 2.3% to 10.9%, due to decreased energy consumption and other factors.
The study also noted that China's recently announced plan to become carbon neutral by 2060 largely accords with the 1.5 °C warming limit; however, achieving the latter goal is more challenging.
China requires switch to zero-carbon energy to achieve more ambitious Paris Agreement goal, models S
AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE
A new multi-model analysis suggests that China will need to reduce its carbon emissions by over 90% and its energy consumption by almost 40%, in order to meet the more ambitious target set by the 2016 Paris Agreement. The Agreement called for no more than a 1.5°Celsius (C) global temperature rise by 2050. These results provide a clear directive for China to deploy multiple strategies at once for long-term emission mitigation, the authors say. The findings also highlight the need for more research on the economic consequences of working toward a 1.5°C warming limit, arguing that current studies are far from adequate to inform the sixth assessment report (AR 6) on climate change planned for release by the United Nations' Intergovernmental Panel on Climate Change in 2022. Most research to inform climate policy has centered on the goal of 2.0°C, and to date, "there is clearly no consensus on the attractiveness of a 1.5°C target, particularly given the uncertainty in associated mitigation costs," say Hongbo Duan and colleagues. To help fill in this gap, Duan et al. used multiple climate models to assess how China might attain this goal by mid-century. All models consistently showed that of all sectors, industry is the main emission contributor, and the power sector would need to achieve full decarbonization to meet the 1.5°C goal by 2050. Negative emission technologies would play an important role in the achievement of near-zero emissions, with captured carbon accounting on average for 20% of total reductions by 2050. Furthermore, the researchers found that the cost of policies to attain this goal may amount to 2.8% to 5.7% of China's gross domestic product by 2050. For future work, the authors note the need for improving representation of technology and climate-associated economic damage in future climate models.
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Political polarization: Often not as bad as we think
COLUMBIA UNIVERSITY'S MAILMAN SCHOOL OF PUBLIC HEALTH
As politics grows increasingly polarized, a new global study finds people often exaggerate political differences and negative feelings of those on the opposite side of the political divide, and this misperception can be reduced by informing them of the other side's true feelings. The study replicates earlier research in the United States, finding the phenomenon to be generalizable across 25 countries.
The new study was led by Kai Ruggeri, PhD, assistant professor of health policy and management at Columbia University Mailman School of Public Health, and replicates a 2020 study by Jeffrey Lees and Mina Cikara at Harvard University, who were also co-authors of the new study. The new findings appear in the journal Nature Human Behaviour.
The Lee and Cikara study presented five political scenarios (e.g. banning anonymous political donations or changing the name given to the state highway) whereby one group proposes a change in law or policy which could disadvantage the other political party (Democrat or Republican). The new study replicated experiments from the original paper, testing the findings in 10,207 participants, following the original methodology as closely as possible and adapting group divisions and scenarios to the local political context for each of the other countries. For example, in Canada, they asked participants to respond to proposed changes to the way voting districts are defined; in Sudan, participants considered changes to the way water tariffs are calculated.
Says Ruggeri: "Our study provides evidence that people around the world overestimate the negative feelings of their political opponents, when in fact the other side is often much less negative than the perceptions we harbor about the other group. These misperceptions have real-world consequences, from polarization, intergroup conflict, and increasingly aggressive narratives in traditional and social media.
"While differences between the beliefs and actions of opposing political parties undoubtedly exist--particularly on widely covered issues like gun ownership or access to reproductive healthcare--their opinions on less reported issues are often more similar than we think. The findings from our study suggest that focusing on issues without making them partisan matters, while also presenting accurate representations of group beliefs, can directly mitigate the exaggeration of polarization," he adds.
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The study is a collaboration between 82 authors from 42 institutions; as well as 16 interns and 43 alumni from the Junior Researcher Programme, a global initiative for early career researchers in the behavioral sciences partnering with Columbia Global Programs; 14 students from the Global Scholars Programme in Europe: Global Behavioral Science (GLOBES); and other volunteers.
The future looks bright for infinitelyrecyclable plastic
A new environmental and technological analysis suggests that a revolutionary eco-friendly plastic is almost ready to hit the shelves
IMAGE: BRETT HELMS, FOREGROUND, PICTURED AT WORK IN THE MOLECULAR FOUNDRY IN 2019. view more
CREDIT: (CREDIT: THOR SWIFT/BERKELEY LAB)
Plastics are a part of nearly every product we use on a daily basis. The average person in the U.S. generates about 100 kg of plastic waste per year, most of which goes straight to a landfill. A team led by Corinne Scown, Brett Helms, Jay Keasling, and Kristin Persson at Lawrence Berkeley National Laboratory (Berkeley Lab) set out to change that.
Less than two years ago, Helms announced the invention of a new plastic that could tackle the waste crisis head on. Called poly(diketoenamine), or PDK, the material has all the convenient properties of traditional plastics while avoiding the environmental pitfalls, because unlike traditional plastics, PDKs can be recycled indefinitely with no loss in quality.
Now, the team has released a study that shows what can be accomplished if manufacturers began using PDKs on a large scale. The bottom line? PDK-based plastic could quickly become commercially competitive with conventional plastics, and the products will get less expensive and more sustainable as time goes on.
"Plastics were never designed to be recycled. The need to do so was recognized long afterward," explained Nemi Vora, first author on the report and a former postdoctoral fellow who worked with senior author Corinne Scown. "But driving sustainability is the heart of this project. PDKs were designed to be recycled from the get-go, and since the beginning, the team has been working to refine the production and recycling processes for PDK so that the material could be inexpensive and easy enough to be deployed at commercial scales in anything from packaging to cars."
The study presents a simulation for a 20,000-metric-ton-per-year facility that puts out new PDKs and takes in used PDK waste for recycling. The authors calculated the chemical inputs and technology needed, as well as the costs and greenhouse gas emissions, then compared their findings to the equivalent figures for production of conventional plastics.
"These days, there is a huge push for adopting circular economy practices in the industry. Everyone is trying to recycle whatever they're putting out in the market," said Vora. "We started talking to industry about deploying 100% percent infinitely recycled plastics and have received a lot of interest."
"The questions are how much it will cost, what the impact on energy use and emissions will be, and how to get there from where we are today," added Helms, a staff scientist at Berkeley Lab's Molecular Foundry. "The next phase of our collaboration is to answer these questions."
Checking the boxes of cheap and easy
To date, more than 8.3 billion metric tons of plastic material have been produced, and the vast majority of this has ended up in landfills or waste incineration plants. A small proportion of plastics are sent to be recycled "mechanically," meaning they are melted down and then re-shaped into new products. However, this technique has limited benefit. Plastic resin itself is made of many identical molecules (called monomers) bound together into long chains (called polymers). Yet to give plastic its many textures, colors, and capabilities, additives like pigments, heat stabilizers, and flame retardants are added to the resin. When many plastics are melted down together, the polymers become mixed with a slew of potentially incompatible additives, resulting in a new material with much lower quality than newly produced virgin resin from raw materials. As such, less than 10% of plastic is mechanically recycled more than once, and recycled plastic usually also contains virgin resin to make up for the dip in quality.
PDK plastics sidestep this problem entirely - the resin polymers are engineered to easily break down into individual monomers when mixed with an acid. The monomers can then be separated from any additives and gathered to make new plastics without any loss of quality. The team's earlier research shows that this "chemical recycling" process is light on energy and carbon dioxide emissions, and it can be repeated indefinitely, creating a completely circular material lifecycle where there is currently a one-way ticket to waste.
Yet despite these incredible properties, to truly beat plastics at their own game, PDKs also need to be convenient. Recycling traditional petroleum-based plastic might be hard, but making new plastic is very easy.
"We're talking about materials that are basically not recycled," said Scown. "So, in terms of appealing to manufacturers, PDKs aren't competing with recycled plastic - they have to compete with virgin resin. And we were really pleased to see how cheap and how efficient it will be to recycle the material."
Scown, who is a staff scientist in Berkeley Lab's Energy Technologies and Biosciences Areas, specializes in modeling future environmental and financial impacts of emerging technologies. Scown and her team have been working on the PDK project since the outset, helping Helms' group of chemists and fabrication scientists to choose the raw materials, solvents, equipment, and techniques that will lead to the most affordable and eco-friendly product.
"We're taking early stage technology and designing what it would look like at commercial-scale operations" using different inputs and technology, she said. This unique, collaborative modeling process allows Berkeley Lab scientists to identify potential scale-up challenges and make process improvements without costly cycles of trial and error.
The team's report, published in Science Advances, models a commercial-scale PDK production and recycling pipeline based on the plastic's current state of development. "And the main takeaways were that, once you've produced the PDK initially and you've got it in the system, the cost and the greenhouse gas emissions associated with continuing to recycle it back to monomers and make new products could be lower than, or at least on par with, many conventional polymers," said Scown.
Planning to launch
Thanks to optimization from process modeling, recycled PDKs are already drawing interest from companies needing to source plastic. Always looking to the future, Helms and his colleagues have been conducting market research and meeting with people from industry since the project's early days. Their legwork shows that the best initial application for PDKs are markets where the manufacturer will receive their product back at the end of its lifespan, such as the automobile industry (through trade-ins and take-backs) and consumer electronics (through e-waste programs). These companies will then be able to reap the benefits of 100% recyclable PDKs in their product: sustainable branding and long-term savings.
"With PDKs, now people in industry have a choice," said Helms. "We're bringing in partners who are building circularity into their product lines and manufacturing capabilities, and giving them an option that is in line with future best practices."
Added Scown: "We know there's interest at that level. Some countries have plans to charge hefty fees on plastic products that rely on non-recycled material. That shift will provide a strong financial incentive to move away from utilizing virgin resins and should drive a lot of demand for recycled plastics."
After infiltrating the market for durable products like cars and electronics, the team hopes to expand PDKs into shorter-lived, single-use goods such as packaging.
A full circle future
As they forge plans for a commercial launch, the scientists are also continuing their techno-economic collaboration on the PDK production process. Although the cost of recycled PDK is already projected to be competitively low, the scientists are working on additional refinements to lower the cost of virgin PDK, so that companies are not deterred by the initial investment price.
And true to form, the scientists are working two steps ahead at the same time. Scown, who is also vice president for Life-cycle, Economics & Agronomy at the Joint BioEnergy Institute (JBEI), and Helms are collaborating with Jay Keasling, a leading synthetic biologist at Berkeley Lab and UC Berkeley and CEO of JBEI, to design a process for producing PDK polymers using microbe-made precursor ingredients. The process currently uses industrial chemicals, but was initially designed with Keasling's microbes in mind, thanks to a serendipitous cross-disciplinary seminar.
"Shortly before we started the PDK project, I was in a seminar where Jay was describing all the molecules that they could make at JBEI with their engineered microbes," said Helms. "And I got very excited because I saw that some of those molecules were things that we put in PDKs. Jay and I had a few chats and, we realized that nearly the entire polymer could be made using plant material fermented by engineered microbes."
"In the future, we're going to bring in that biological component, meaning that we can begin to understand the impacts of transitioning from conventional feedstocks to unique and possibly advantaged bio-based feedstocks that might be more sustainable long term on the basis of energy, carbon, or water intensity of production and recycling," Helms continued. "So, where we are now, this is the first step of many, and I think we have a really long runway in front of us, which is exciting."
CAPTION
A GIF showing how PDK plastic readily breaks down when put in an acidic solution. The acid helps to break the bonds between the monomers and separate them from the chemical additives that give plastic its look and feel.
CREDIT
(Credit: Peter Christensen/ Berkeley Lab)
The Molecular Foundry is a Department of Energy (DOE) Office of Science user facility that specializes in nanoscale science. JBEI is a Bioenergy Research Center funded by DOE's Office of Science.
This work was supported by the DOE's Bioenergy Technologies Office and Berkeley Lab's Laboratory Directed Research and Development (LDRD) program.
PDK technology is available for licensing and collaboration. If interested, please contact Berkeley Lab's Intellectual Property Office, ipo@lbl.gov.
Climate-smart ag strategies may cut nitrous oxide emissions from corn production
IMAGE: LEAD RESEARCHER MARIA PONCE DE LEON, A FORMER GRADUATE STUDENT IN PLANT SCIENCE, CARRIES A NITROUS OXIDE EMISSIONS CHAMBER INTO A CORN FIELD AT PENN STATE'S RUSSELL E. LARSON AGRICULTURAL... view more
CREDIT: HEATHER KARSTEN, PENN STATE
For corn, using dairy manure and legume cover crops in crop rotations can reduce the need for inorganic nitrogen fertilizer and protect water quality, but these practices also can contribute to emissions of nitrous oxide -- a potent greenhouse gas.
That is the conclusion of Penn State researchers, who measured nitrous oxide emissions from the corn phases of two crop rotations -- a corn-soybean rotation and a dairy forage rotation -- under three different management regimens. The results of the study offer clues about how dairy farmers might reduce the amount of nitrogen fertilizer they apply to corn crops, saving money and contributing less to climate change.
The results are important because although nitrous oxide accounts for just 7% of U.S. greenhouse gas emissions, it is significantly more potent than carbon dioxide or methane when it comes to driving climate change, according to Heather Karsten, associate professor of crop production/ecology in the College of Agricultural Sciences. Nitrous oxide is almost 300 times more powerful than carbon dioxide and remains in the atmosphere for more than 100 years.
"This research suggests that all nitrogen inputs -- manure, legumes and fertilizer -- contribute to nitrous oxide emissions," she said. "But farmers could reduce nitrous oxide emissions if they could apply manure after the crop is planted, closer to when the corn begins to take up nitrogen.
"And if they could apply manure only when the crop needs it by "side-dressing," she added, "they likely could use less inorganic nitrogen fertilizer. But equipment for side-dressing manure into a growing corn crop is not yet widely available."
Researchers compared the effects of three management treatments for no-till corn and measured nitrous oxide emissions throughout the corn growing season. In the corn-soybean rotation, the team compared nitrous oxide emissions from broadcasting dairy manure, shallow disk manure injection, and the application of inorganic fertilizer in the form of liquid urea ammonium nitrate.
Manure was applied before corn was planted, as most farms do, while in the inorganic fertilizer treatment, fertilizer was applied according to recommended practices -- when the corn was growing and taking up nitrogen.
This better timing for nitrogen application allowed for a reduced total nitrogen application, and the nitrous oxide emissions were lower than with the injected manure treatment. Injecting manure increased nitrous oxide emissions compared to the broadcast manure treatment in one year of the study, indicating that the environmental and nitrogen-conservation benefits of injection should be weighed against the additional emissions when selecting the practice.
The researchers also compared nitrous oxide emissions from corn grown for silage or grain in the no-till, six-year, dairy forage rotation in which corn followed a two-year, mixed alfalfa and orchardgrass forage crop and also a crimson clover cover crop. Manure also was broadcasted before corn planting, and nitrous oxide emissions were compared to the rotation in which corn was planted after soybean with broadcast manure. The nitrous oxide emissions during the corn season didn't differ among the three prior legume treatments.
In both experiments, nitrous oxide emissions peaked a few weeks after manure was applied and for a short period after fertilizer was applied. Since nitrous oxide emissions are influenced by factors that influence microbial processes, the researchers examined what environmental and nitrogen-availability factors were most predictive of nitrous oxide emissions. Increasing temperatures spurring corn growth and factors that influence soil nitrogen availability were important factors in both comparisons.
The study shows that nitrogen availability from organic inputs such as manure and legume cover crops can contribute to nitrous oxide emissions from corn, noted lead researcher Maria Ponce de Leon, former graduate student in Karsten's research group, now a doctoral candidate at the University of California, Davis. Identifying how to time organic nitrogen amendments with corn uptake represents an opportunity, she said, to reduce nitrous oxide emissions from dairy production systems.
Now, dairy farmers apply manure mostly prior to planting corn, and as the manure and the organic legume biomass from the cover crop decompose, the nitrogen content builds in the soil. Some of it can be lost as nitrous oxide emissions or leach into groundwater.
"Until the corn is rapidly taking up nitrogen from the soil, there's potential for both of those environmental losses," Ponce de Leon said. "If we could better synchronize the timing of the manure application to when the corn is growing and taking up nitrogen, we could reduce nitrous oxide missions. That also would help the crop and the farmer better capture the nitrogen that's available in that manure."
CAPTION
Using measuring chambers like those shown here, researchers found that nitrous oxide emissions peaked a few weeks after manure was applied and for a short period after fertilizer was applied. Identifying how to time organic nitrogen amendments with corn uptake represents an opportunity to reduce nitrous oxide emissions from dairy production systems, the researchers said.
CREDIT
Maria Ponce de Leon, Penn State
The research, recently published in Nutrient Cycling in Agroecosystems, was conducted at Penn State's Russell E. Larson Agricultural Research Center as part of the much larger "Dairy Cropping Systems" project that has been underway for more than a decade. Initiated in 2010, that parent project aims to sustainably produce the forage and feed for a typical 65-cow, 240-acre dairy farm in Pennsylvania.
Curtis Dell, soil scientist with the U.S. Department of Agriculture's Agricultural Research Service Pasture Systems and Watershed Management Research Unit, contributed to the research.
The U.S. Department of Agriculture supported this work.
Two studies analyze survivors exposed to radiation after the Chernobyl accident, and their children
AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE
Children whose parents had been exposed to radiation from the Chernobyl Nuclear Power Plant accident in 1986 had no excess germline mutations, a new whole-genome sequencing study shows. "This is one of the first studies to systematically evaluate alterations in human mutation rates in response to a man-made disaster, such as accidental radiation exposure," say the authors. Effects of radiation exposure from the Chernobyl nuclear accident, which occurred at a power plant in Ukraine in April 1986, remain a topic of interest. To date, there have been several studies examining transgenerational risks of radiation exposure from events such as this, but the results have been inconclusive. What's more, no large comprehensive effort has explored germline de novo mutations genome-wide in children born from parents exposed to moderately high amounts of ionizing radiation, even as possible genetic effects from such events have remained a concern for radiation-exposed populations like the Fukushima evacuees. To examine whether rates of germline de novo mutations are elevated in children born to parents exposed to ionizing radiation, Meredith Yeager et al. analyzed the genomes of 130 children and parents from families where one or both parents had experienced gonadal radiation exposure related to the Chernobyl accident and where the children were conceived after the accident - and born between 1987 and 2002. The authors did not find an increase in new germline mutations in this population. The incidence of germline de novo mutations was comparable to that reported in the general population, they say. "[O]ur study does not provide support for a transgenerational effect of ionizing radiation on germline DNA in humans," they conclude.
In a second study examining the effects of radioactive fallout on survivors of the Chernobyl nuclear accident, researchers provide more insights into the process of radiation-induced papillary thyroid cancers - one of the most frequent cancers observed after the Chernobyl event. "These findings substantially extend preliminary reports of radiation-related human tumor characteristics by integrating data from multiple platforms with large sample size and detailed radiation dose data," the authors say. Exposure to radioactive fallout increases the risk of cancer, particularly papillary thyroid carcinoma (PTC). However, a detailed molecular understanding of these tumors is still lacking, and there are no established markers of radiation-induced cancers. Lindsay Morton et al. analyzed thyroid tumors, normal thyroid tissue, and blood from hundreds of survivors of the Chernobyl nuclear accident and compared them to those of unexposed patients. While no unique radiation-related biomarker was identified, the results reveal radiation dose-related increases in DNA double-strand breaks in human thyroid cancers developing after the Chernobyl accident. Radiation-related genomic alterations were more pronounced for those younger at exposure, the authors say. Their results suggest that thyroid tumor development following radiation exposure results from DNA double-strand breaks in the genome. The authors say their results have implications for radiation protection and public health, particularly for low dose exposure.
NEWS RELEASE
International research teams explore genetic effects of Chernobyl radiation
In two landmark studies, researchers have used cutting-edge genomic tools to investigate the potential health effects of exposure to ionizing radiation, a known carcinogen, from the 1986 accident at the Chernobyl nuclear power plant in northern Ukraine. One study found no evidence that radiation exposure to parents resulted in new genetic changes being passed from parent to child. The second study documented the genetic changes in the tumors of people who developed thyroid cancer after being exposed as children or fetuses to the radiation released by the accident.
The findings, published around the 35th anniversary of the disaster, are from international teams of investigators led by researchers at the National Cancer Institute (NCI), part of the National Institutes of Health. The studies were published online in Science on April 22.
"Scientific questions about the effects of radiation on human health have been investigated since the atomic bombings of Hiroshima and Nagasaki and have been raised again by Chernobyl and by the nuclear accident that followed the tsunami in Fukushima, Japan," said Stephen J. Chanock, M.D., director of NCI's Division of Cancer Epidemiology and Genetics (DCEG). "In recent years, advances in DNA sequencing technology have enabled us to begin to address some of the important questions, in part through comprehensive genomic analyses carried out in well-designed epidemiological studies."
The Chernobyl accident exposed millions of people in the surrounding region to radioactive contaminants. Studies have provided much of today's knowledge about cancers caused by radiation exposures from nuclear power plant accidents. The new research builds on this foundation using next-generation DNA sequencing and other genomic characterization tools to analyze biospecimens from people in Ukraine who were affected by the disaster.
The first study investigated the long-standing question of whether radiation exposure results in genetic changes that can be passed from parent to offspring, as has been suggested by some studies in animals. To answer this question, Dr. Chanock and his colleagues analyzed the complete genomes of 130 people born between 1987 and 2002 and their 105 mother-father pairs.
One or both of the parents had been workers who helped clean up from the accident or had been evacuated because they lived in close proximity to the accident site. Each parent was evaluated for protracted exposure to ionizing radiation, which may have occurred through the consumption of contaminated milk (that is, milk from cows that grazed on pastures that had been contaminated by radioactive fallout). The mothers and fathers experienced a range of radiation doses.
The researchers analyzed the genomes of adult children for an increase in a particular type of inherited genetic change known as de novo mutations. De novo mutations are genetic changes that arise randomly in a person's gametes (sperm and eggs) and can be transmitted to their offspring but are not observed in the parents.
For the range of radiation exposures experienced by the parents in the study, there was no evidence from the whole-genome sequencing data of an increase in the number or types of de novo mutations in their children born between 46 weeks and 15 years after the accident. The number of de novo mutations observed in these children were highly similar to those of the general population with comparable characteristics. As a result, the findings suggest that the ionizing radiation exposure from the accident had a minimal, if any, impact on the health of the subsequent generation.
"We view these results as very reassuring for people who were living in Fukushima at the time of the accident in 2011," said Dr. Chanock. "The radiation doses in Japan are known to have been lower than those recorded at Chernobyl."
In the second study, researchers used next-generation sequencing to profile the genetic changes in thyroid cancers that developed in 359 people exposed as children or in utero to ionizing radiation from radioactive iodine (I-131) released by the Chernobyl nuclear accident and in 81 unexposed individuals born more than nine months after the accident. Increased risk of thyroid cancer has been one of the most important adverse health effects observed after the accident.
The energy from ionizing radiation breaks the chemical bonds in DNA, resulting in a number of different types of damage. The new study highlights the importance of a particular kind of DNA damage that involves breaks in both DNA strands in the thyroid tumors. The association between DNA double-strand breaks and radiation exposure was stronger for children exposed at younger ages.
Next, the researchers identified the candidate "drivers" of the cancer in each tumor -- the key genes in which alterations enabled the cancers to grow and survive. They identified the drivers in more than 95% of the tumors. Nearly all the alterations involved genes in the same signaling pathway, called the mitogen-activated protein kinase (MAPK) pathway, including the genes BRAF, RAS, and RET.
The set of affected genes is similar to what has been reported in previous studies of thyroid cancer. However, the researchers observed a shift in the distribution of the types of mutations in the genes. Specifically, in the Chernobyl study, thyroid cancers that occurred in people exposed to higher radiation doses as children were more likely to result from gene fusions (when both strands of DNA are broken and then the wrong pieces are joined back together), whereas those in unexposed people or those exposed to low levels of radiation were more likely to result from point mutations (single base-pair changes in a key part of a gene).
The results suggest that DNA double-strand breaks may be an early genetic change following exposure to radiation in the environment that subsequently enables the growth of thyroid cancers. Their findings provide a foundation for further studies of radiation-induced cancers, particularly those that involve differences in risk as a function of both dose and age, the researchers added.
"An exciting aspect of this research was the opportunity to link the genomic characteristics of the tumor with information about the radiation dose -- the risk factor that potentially caused the cancer," said Lindsay M. Morton, Ph.D., deputy chief of the Radiation Epidemiology Branch in DCEG, who led the study.
"The Cancer Genome Atlas set the standard for how to comprehensively profile tumor characteristics," Dr. Morton continued. "We extended that approach to complete the first large genomic landscape study in which the potential carcinogenic exposure was well-characterized, enabling us to investigate the relationship between specific tumor characteristics and radiation dose."
She noted that the study was made possible by the creation of the Chernobyl Tissue Bank about two decades ago -- long before the technology had been developed to conduct the kind of genomic and molecular studies that are common today.
"These studies represent the first time our group has done molecular studies using the biospecimens that were collected by our colleagues in Ukraine," Dr. Morton said. "The tissue bank was set up by visionary scientists to collect tumor samples from residents in highly contaminated regions who developed thyroid cancer. These scientists recognized that there would be substantial advances in technology in the future, and the research community is now benefiting from their foresight."
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About the National Cancer Institute (NCI): NCI leads the National Cancer Program and NIH's efforts to dramatically reduce the prevalence of cancer and improve the lives of cancer patients and their families, through research into prevention and cancer biology, the development of new interventions, and the training and mentoring of new researchers. For more information about cancer, please visit the NCI website at cancer.gov or call NCI's contact center, the Cancer Information Service, at 1-800-4-CANCER (1-800-422-6237).
About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit nih.gov
ALL CAPITALISM IS STATE CAPITALISM
COVID-19 vaccine development built on >$17 billion in NIH funding for vaccine technologies
Broad foundation of NIH-funded research for enabling technologies prior to pandemic provided a tool kit for rapid development of COVID vaccines
The unprecedented development of COVID-19 vaccines less than a year after discovery of this virus was enabled by more than $17 billion of research on vaccine technologies funded by the NIH prior to the pandemic, according to new research from Bentley University'sCenter for Integration of Science and Industry. The article, titled "NIH funding for vaccine readiness before the COVID-19 pandemic," demonstrates the critical role this broad foundation of government-funded research plays in ensuring vaccine readiness.
The report, published today in the journal Vaccine, examined the maturation of research and NIH funding for ten technologies that were applied in candidate COVID-19 vaccines as of July 2020. The maturation of these technologies was described in 51,530 published research papers from 2000-2019, of which 8,420 (16%) acknowledge NIH funding totaling $17.2 billion. Some of these technologies have been employed successfully in vaccines since the mid-20th century. Others, such as the viral vectors employed in the Johnson & Johnson and AstraZeneca vaccines, emerged from genetic engineering in the 1980s, and were found to be established prior to 2010. Still others, including the mRNA technologies employed by Pfizer/BioNTech and Moderna, only recently reached an established point.
"Rapid development of COVID vaccines was only possible because companies had access to a tool kit of established technologies," said Dr. Fred Ledley, Director of the Center for Integration of Science and Industry. "Some of the most recent technologies, including mRNA and viral vectors, proved to be particularly suitable for COVID-19 and the timelines required to combat this pandemic. The substantial public sector investments over the past 20 years that went into the maturation of these technologies needs to be considered in the pricing of these products and their availability to the public."
"This study also found surprisingly little NIH-funded, published research on vaccines for recognized pandemic threats, such as coronavirus, Zika, Ebola, or dengue virus," said Dr. Anthony Kiszewski, lead author of the study and Associate Professor of Natural & Applied Science at Bentley University. "Mechanisms need to be developed for funding research on vaccine technologies that accelerate vaccine development against emergent threats and preempt future pandemics."
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Dr. Anthony Kiszewski was the lead author on this work along with Dr. Ekaterina Galkina Cleary, Dr. Matthew Jackson and Dr. Fred Ledley. This work was supported by a grant from the National Biomedical Research Foundation.
"NIH funding for vaccine readiness before the COVID-19 pandemic" DOI: https://doi.org/10.1016/j.vaccine.2021.03.022. It is published in Vaccine, Volume 39 (2021) published by Elsevier.
THE CENTER FOR INTEGRATION OF SCIENCE AND INDUSTRY at Bentley University focuses on advancing the translation of scientific discoveries to create public value. The Center is an environment for thought leadership and interdisciplinary scholarship spanning basic science, data analytics, business and public policy. For more information, visit http://www.bentley.edu/sciindustry and follow us on Twitter @sciindustry.
BENTLEY UNIVERSITY is more than just one of the nation's top business schools. It is a lifelong-learning community that creates successful leaders who make business a force for positive change. With a combination of business and the arts and sciences and a flexible, personalized approach to education, Bentley provides students with critical thinking and practical skills that prepare them to lead successful, rewarding careers. Founded in 1917, the university enrolls 4,200 undergraduate and 1,000 graduate and PhD students and is set on 163 acres in Waltham, Massachusetts, 10 miles west of Boston. For more information, visit bentley.edu. Follow us on Twitter @BentleyU #BentleyUResearch.
About Vaccine
Vaccine is the pre-eminent journal for those interested in vaccines and vaccination. It is the official journal of The Edward Jenner Society and The Japanese Society for Vaccinology and is published by Elsevier http://www.elsevier.com/locate/vaccine
