FASCISTS HAVE NO RIGHT TO FREE SPEECH

Poilievre promises to protect freedom of speech on campus, appoint a 'Free Speech Guardian'

Catherine Lévesque - National Post

The idea of withholding federal funds from universities in order to protect free speech on campus is not new.

Conservative leadership hopeful Pierre Poilievre is threatening to remove direct federal research and other grants from Canadian universities if they do not commit to protect academic freedom and free speech from “campus gatekeepers.”

If he forms government, Poilievre promises to appoint a former judge which will act as a “Free Speech Guardian” who will ensure that universities respect the principles enshrined in the Charter of Rights and Freedoms, in particular section 2(b) which protects “freedom of thought, belief, opinion and expression.”

The former judge will be responsible for ensuring compliance by universities to these principles of academic freedom and free speech, but will also investigate claims of academic censorship.

Examples could include having pro-life or pro-Israel student groups cancel events or lose resources because of their different viewpoints, or having professors such as Jordan Peterson resign his post because of his “unacceptable philosophical positions” from his own account .


The “Free Speech Guardian” would be responsible for enforcing Poilievre’s policy by reporting to the federal government on universities’ breaches and for recommending reductions in direct federal grants to those that do not uphold the principles in the Charter. Federal-provincial transfers would not be affected by the free speech requirements.

Most support professor's use of racist language, in context: poll

U of T talk by anti-Israel activist tests Ontario’s campus free speech policy

There would, however, be limitations to Poilievre’s proposal. Hate speech will continue to be prohibited, as the courts have rules that it can be banned under the Charter.

“The Charter protects free speech, not hate speech, as explained by the Supreme Court of Canada. So does my academic freedom and free speech policy,” said Poilievre in a written statement to the National Post when asked for more specifics.

The idea of withholding federal funds from universities in order to protect free speech on campus is not new. In fact, former Conservative leader Andrew Scheer made this a promise during his own leadership campaign in 2017, and reiterated in his victory speech that “the foundation of our democracy is the ability to have a debate about any subject.”

But education remains a provincial jurisdiction and some provinces have already taken action to do just that.

In 2019, Ontario announced that all colleges and universities had developed, implemented and complied with a free speech policy while ensuring that hate speech and discrimination are not allowed on campus. Alberta also encouraged all publicly funded post-secondary institutions to adopt the Chicago Principles to encourage freedom of speech around that time.

More recently, Quebec adopted a law to enforce new rules around academic freedom across the province, ensuring that “any word” can be spoken in a university classroom as long as it is used in an academic context.

Quebec’s initiative was an indirect response to a University of Ottawa professor’s use of the N-word during a lecture that led to her suspension. The events played out differently in Ontario, where the province’s free speech policy had no effect, and in Quebec, where politicians of all stripes ran to the professor’s defence, invoking her right to use the derogatory word.

Poilievre’s campaign did not respond to followup questions regarding if his free speech policy would let a professor use the N-word in class for academic purposes.

Geneviève Tellier, a professor at the University of Ottawa who co-authored a book to denounce her colleague’s treatment at the time of her suspension, said that Ontario’s free speech policy was already in place when the events happened and did not change anything to the situation.

She seemed skeptical of Poilievre’s suggestion to have a national oversight, adding that it would only add another level of complexity.

“We already have a Free Speech Guardian. It’s the Charter of Rights and Freedoms,” said Tellier in an interview. “And we have the judicial system. Do we need something else? In my opinion, it would only add another administrative burden.”

She also added that Poilievre seems to mix up freedom of speech and academic freedom, stressing that universities do not exist to advance different agendas, but to advance knowledge.

That being said, it came as no surprise to the professor of political studies why the leadership candidate would tap into that theme as part of his campaign.

“Because there’s the word freedom. His whole campaign is driven by freedom.”

These tiny marsupials survived wildfires only to face extinction from feral cats

The Kangaroo Island dunnart was one species seen to reemerge after Australian bushfires

At about 7.5 centimeters long (not counting its tail), this Kangaroo Island dunnart — caught in 2022 during routine monitoring of the island’s wild inhabitants — easily fits in the palm of a hand.
PAT HODGENS


By Asa Stahl
JUNE 16, 2022 

Few marsupials have gone from miraculous survival to the brink of extinction as quickly as the Kangaroo Island dunnart.

In 2019 and 2020, devastating fires burned nearly 10 million hectares of southeastern Australia. The flames threatened hundreds of species with extinction, but the Kangaroo Island dunnart (Sminthopsis aitkeni) — which already numbered less than 500 before the fires — seemed to be one that defied expectations in the aftermath (SN: 3/9/21).

But now these rare creatures may be more at risk than ever, researchers say June 16 in Scientific Reports. The danger, as domestic as it sounds, is getting eaten by a cat.

As of 2008, invasive feral cats had contributed to at least 13 percent of extinctions worldwide. That’s one reason the government has been euthanizing cats on Kangaroo Island for years. The scientists who conducted the dunnart study knew all this — but when they studied the remains of cats euthanized in 2020, they were still surprised by what they saw: Seven out of 86 cats had recently dined on dunnart.

“We were not expecting to find so many,” says Louis Lignereux, a field researcher at the University of Adelaide School of Animal and Veterinary Science. It’s particularly bad news, he says, if you think of what was in the cats as only a snapshot of what they ate in the last 36 hours. Taking that into account, those seven cats alone could have eaten enough to wipe out the Kangaroo Island dunnart within a few months, if they had survived — and there are hundreds of other cats on the island.

A small habitat makes the dunnarts especially vulnerable. It’s like putting all your eggs in one basket, Lignereux says. Since the fires, the Kangaroo Island dunnart is thought to now live in an area about one-tenth of the size of Manhattan (SN: 1/13/20).

“If something happened to this spot,” he says, “then [the dunnart] is gone forever.”

Questions or comments on this article? E-mail us at feedback@sciencenews.org

CITATIONS

P. Hodgens et al. Cat predation of Kangaroo Island dunnarts in aftermath of bushfire. Scientific Reports. Published online June 16, 2022. doi: 10.1038/s41598-022-11383-6.

F.M. Medina et al. A global review of the impacts of invasive cats on island endangered vertebrates. Global Change Biology. Vol. 17, June 3, 2011, p. 3503–3510. doi: 10.1111/j.1365-2486.2011.02464.x.

About Asa StahlE-mail
Asa Stahl is the 2022 AAAS Mass Media fellow with Science News. He is a 5th year Astrophysics Ph.D. student at Rice University, where his research focuses on detecting and characterizing young stars and planets.

Western wildfires’ health risks extend across the country

Those fires devastating communities in the West send bad air traveling, boosting emergency room visits in the East

Western wildfires, like the 2018 Camp Fire in Paradise, Calif., are devastating for local communities. Their smoke also travels to heavily populated areas to the east. Researchers are beginning to study the health effects for people far from the fires.
JOSH EDELSON/AFP VIA GETTY IMAGES

By Megan Sever
JUNE 17, 2022

After a relaxing day at the Jersey Shore last July, Jessica Reeder and her son and daughter headed back home to Philadelphia. As they crested a bridge from New Jersey into Pennsylvania, they were greeted with a hazy, yellow-gray sky. It reminded Reeder of the smoky skies she saw growing up in Southern California on days when fires burned in the dry canyons.

Smelling smoke and worried about her asthma and her kids, Reeder flipped the switch to recirculate the air inside the car instead of drawing from the outside. At home, the family closed all the windows and turned their air purifiers on high.

The smoke had traveled from fires raging on the other side of the continent, in the western United States and Canada. Although air quality in Philadelphia didn’t come close to the record-bad air quality that some western cities experienced, it was bad enough to trigger air quality warnings — and not just for people with asthma or heart problems.

Most large U.S. wildfires occur in the West. But the smoke doesn’t stay there. It travels eastward, affecting communities hundreds to thousands of kilometers away from the fires. In fact, the majority of asthma-related deaths and emergency room visits attributed to fire smoke in the United States occur in eastern cities, according to a study in the September 2021 GeoHealth.

Smoke poured into the eastern United States and Canada from wildfires in the West on July 21, 2021 (darker red is denser smoke). Residents of eastern cities received code orange and code red warnings that air quality was unhealthy.

JOSHUA STEVENS/NASA EARTH OBSERVATORY

The big problem is fine particulate matter, tiny particles also known as PM2.5. These bits of ash, gases and other detritus suspended in smoke are no more than 2.5 micrometers wide, small enough to lodge in the lungs and cause permanent damage. PM2.5 exacerbates respiratory and cardiovascular problems and can lead to premature death. The particles can also cause asthma and other chronic conditions in otherwise healthy adults and children.

Over the last few decades, U.S. clean air regulations have cut down on particulate matter from industrial pollution, so the air has been getting cleaner, especially in the populous eastern cities. But the regulations don’t address particulate matter from wildfire smoke, which recent studies show is chemically different from industrial air pollution, potentially more hazardous to humans and increasing significantly.

So far, a lot of the research on how wildfire PM2.5 can make people sick has been based on people living or working near fires in the West. Now, researchers are turning their attention to how PM2.5 from smoke affects the big population centers in the East, far from the wildfires. One thing is clear: With the intensity and frequency of wildfires increasing due to climate change (SN: 12/19/20 & 1/2/21, p. 32), people across North America need to be concerned about the health impacts, says Katelyn O’Dell, an atmospheric scientist at George Washington University in Washington, D.C.

Bad air travels

Air pollution regulations limit PM2.5 from exhaust-emitting cars and trucks and fossil fuel–burning factories and power plants. These regulations have done “a really good job” reducing anthropogenic air pollution in the last couple of decades, says Rosana Aguilera, an environmental scientist at the Scripps Institution of Oceanography in La Jolla, Calif. In the United States, concentrations of six of the most common air pollutants have dropped by 78 percent since the Clean Air Act of 1970, according to the U.S. Environmental Protection Agency. PM2.5 concentrations have come down as well — at least until recently.

Western wildfires, which are growing more frequent, more severe and larger, are erasing some of the gains made in reducing industrial pollution, says Rebecca Buchholz, an atmospheric chemist at the National Center for Atmospheric Research in Boulder, Colo.

Fires in the Pacific Northwest are “driving an upward trend” in particulate matter air pollution, Buchholz and colleagues wrote April 19 in Nature Communications. Such smoke pollution peaks in August when fires in the region tend to spike and the atmosphere’s ability to clean itself through, say, rain, is limited. This spike of late-summer air pollution is new, Buchholz says. It’s especially noticeable since 2012.

New York City, visible through hazy skies in September 2020, and many places in the East have seen some of the worst air quality in decades due to fires burning in the U.S. West and in Canada. Such fires are increasing in intensity and frequency.

GARY HERSHORN/GETTY IMAGES PLUS

And, as Reeder and her family experienced last year, transported wildfire pollution is causing substantial particulate matter spikes in the central United States and northeastern North America, Buchholz and colleagues found. Pacific Northwest wildfires thus “have the potential to impact surface air quality, even at large distances downwind of the wildfires,” the team wrote, putting some 23 million people in the central United States and 72 million in northeastern North America at increased risk of health impacts from the imported wildfire smoke.

How far and where PM2.5 travels depends on weather patterns and how high wildfire smoke reaches — the stronger the fire, the longer it can last and the farther smoke can go, and thus the farther particulate matter can reach. Last year, far-away wildfires created unhealthy air quality conditions in locations from the Great Plains to New York City and Washington, D.C.

New York City saw some of its worst air quality in two decades. Philadelphia had two “code red” days — meaning air quality was unhealthy for all — because of the U.S. West and Canadian fires. In 2019, 2020 and 2021, those fires pushed PM2.5 to unhealthy levels in much of Minnesota. In fact, a 2018 study showed that wildfire smoke plumes now waft above Minnesota for eight to 12 days per month between June and September.

Air safety yardstick

The Air Quality Index, or AQI, ranges from 0 to 500, based on the amount of pollution in the air at a given time. Ground-level ozone, particulate matter (both PM10 and PM2.5), carbon monoxide, sulfur dioxide and nitrogen dioxide are the primary parameters considered in the index. Code orange (above a score of 100) is unhealthy for people with heart and lung disease, older adults, children and people with diabetes. Code red and above (151–500) is unhealthy for everyone.

T. TIBBITTS

Human impacts

Smoke in the West is already having a tangible effect on human health in the East, says O’Dell, lead author of the 2021 GeoHealth study.

Reviewing smoke and health data from 2006 to 2018, O’Dell and colleagues found that more people visit emergency rooms and are hospitalized in the East than in the West from asthma problems attributable to smoke PM2.5. Asthma-related ER visits and hospitalizations were higher east of the Rockies in 11 of the 13 years.

Over the study period, an average of 74 percent of asthma-related deaths and 75 percent of asthma ER visits and hospitalizations attributable to smoke occurred east of the Rockies. Of the estimated 6,300 excess deaths from asthma complications due to smoke PM2.5 that occurred annually over the study period, more than 4,600 were in the East.

Smoke affects so many more people in the East primarily because more people live there, O’Dell notes. Her team defined “West” as west of the Rockies, with a population of 64 million, and “East” as east of the Rockies, home to 226 million people. In the West, smoke PM2.5 causes a higher portion of regional asthma deaths. In the East, it’s a lower portion of the total population, but a far higher total number of people affected.

“We may be already seeing the consequences of these fires on the health of residents who live hundreds or even thousands of miles downwind,” Buchholz said in a press release.

August peaks

Although aerosols, including fine particulate matter, from Pacific Northwest fires have been increasing since 2002, they began a sharp increase in 2012, spiking in the warm, dry summer months. As smoke from the Northwest wafted eastward, similar smaller spikes were seen in the central United States and northeastern North America.
North American seasonal atmospheric aerosol levels, by region

R.R. BUCHHOLZ ET AL/NATURE COMMUNICATIONS 2022 (CC BY 4.0)

Vulnerable youth

“Asthma is a very widespread, common health condition,” says Yang Liu, an environmental scientist at Emory University in Atlanta. In the United States, about 25 million people have asthma, or 8 percent of adults and 7 percent of children, according to the U.S. Centers for Disease Control and Prevention.

Fine particulate matter can spark asthma attacks, but it can also be a danger to people without the condition. Children are especially vulnerable primarily because of physiology. Children breathe faster so they end up taking in more particulate matter, plus their lungs are smaller so more of their lung surface is likely to be damaged when they breathe in particulate matter. And their lungs are still developing, says Jennifer Stowell, an environmental epidemiologist at Boston University School of Public Health.

Stowell led a study, reported in the January Environmental Research Letters, estimating how much wildfire smoke will exacerbate asthma attacks in the West. Stowell, Liu and colleagues estimate that, in the 2050s, there will be an additional 155,000 asthma-related ER visits and hospitalizations per wildfire season in the West just from smoke PM2.5. The biggest concern, Stowell says, is for children and younger adults.

Aguilera, of Scripps, and her colleagues found associations between wildfire-specific PM2.5 and pediatric respiratory-related ER and urgent care visits. In San Diego County from 2011 to 2017, wildfire-specific PM2.5 was 10 times as harmful to respiratory health in children 5 and younger as ambient PM2.5, the researchers reported in 2021 in Pediatrics. In fact, the same increase in levels of PM2.5 from smoke versus ambient sources caused a 26 percent higher rate of ER or urgent care visits. The researchers didn’t note whether the children had preexisting asthma.

And even when a wildfire increased PM2.5 by a small amount, respiratory ER and urgent care visits in kids 12 and under increased, Aguilera and colleagues reported in 2020 in the Annals of the American Thoracic Society. “Even relatively smaller wildfires can still generate quite an impact on the pediatric population,” Aguilera says. “And really, any amount of PM or air pollution is harmful.”

Studies of nonhuman primates have also shown permanent effects of smoke on the young — results researchers expect would also apply to humans, given genetic similarities. In 2008, a group of infant rhesus macaques at the California National Primate Research Center at the University of California, Davis was exposed to high PM2.5 levels from a series of devastating wildfires in Northern California. Researchers have been comparing those monkeys with macaques born a year later that weren’t exposed to smoke.

At the California National Primate Research Center, rhesus macaques that were exposed to wildfire smoke early in life have immune disorders, nervous system changes and weakened lungs.

© 2014 KATHY WEST/CALIFORNIA NATIONAL PRIMATE RESEARCH CENTER/UC DAVIS

At around age 3, macaques exposed to smoke displayed immune disorders and reduced lung capacity, lung function and lung volume, says Hong Ji, a molecular biologist at UC Davis and the primate center who wasn’t involved with this study. The lungs look like they had fibrosis, Ji says. “Early life smoke exposure … changed the trajectory of lung development,” and it doesn’t appear to be reversible, she says.

The monkeys exposed to wildfire PM2.5 also have important changes to how their DNA works, Ji and colleagues reported in the January Environment International. Exposure to wildfire smoke in infancy can cause life-altering, long-term changes to the monkeys’ nervous and immune systems, as well as brain development, Ji says. Even worse, she says, the DNA changes are the type that can be passed down and may result in generational damage.

Even macaques born after in utero exposure to wildfire smoke can suffer cognitive, immune and hormone problems, primate center researchers reported April 1 in Nature Communications.

Now, Ji and colleagues have teamed with Rebecca Schmidt, a molecular epidemiologist at UC Davis who’s leading a study on the effects of wildfire smoke exposure on pregnant women and young children. This research group, as well as other teams, is also looking into whether PM2.5 is causing genetic changes to babies exposed to smoke in utero, Ji says. The more results gathered on the effects of wildfire PM2.5 on babies and children — and even in pregnancy — the more dangerous we realize it is, Ji says.

Chemical differences

Particulate matter changes as it travels through the atmosphere, both in volume and in chemistry. Some PM2.5 is emitted directly from fires, and some is born from chemicals and trace gases emitted from fires that get chemically processed in the atmosphere, Buchholz says. Reactions that happen in the smoke plume, combined with sunlight, can create even more PM2.5 downwind of the fires. How these particulates change chemically — through interactions between the atmosphere and the particulate matter, and between fire pollution and human pollution — and what that means for human health “is a really active area of research right now,” she says. “It’s super complicated.”

Epidemiological and atmospheric chemistry studies indicate that wildfire PM2.5 is more hazardous to human health than ambient PM2.5, says Stowell, the Boston epidemiologist. One such study compared particulate matter from Amazonian fires with urban sources such as vehicle exhaust in Atlanta. Nga Lee Ng, an atmospheric chemist at Georgia Tech, and colleagues found that smoke particulate matter is more toxic than urban particulate matter, “inducing about five times higher cellular oxidative stress,” Ng says. Oxidative stress damages cells and DNA in the body.

In addition, as smoke travels through the atmosphere and ages, it seems to become even more toxic, Ng says. Reactions between the particulate matter and sunlight and atmospheric gases change the particulate matter’s chemical and physical properties, rendering it even more potentially harmful. So, even though particulate matter dissipates over time and distance, “the health effects per gram are greater,” says Daniel Jaffe, an atmospheric chemist at the University of Washington Bothell.

That means that the studies of health effects near wildfires in the West may not represent the full story of how smoke from distant fires affects people in the East.

Liu, at Emory, hopes to see the U.S. government revisit policies related to what PM2.5 levels are dangerous, since they’re based on ambient and not wildfire-related PM2.5. In March, an EPA advisory panel recommended just that. In a letter to the agency, the Clean Air Scientific Advisory Committee wrote: “Regarding the annual PM2.5 standard, all CASAC members agree that the current level of the annual standard is not sufficiently protective of public health and should be lowered.” The committee added, “There is substantial epidemiologic evidence from both morbidity and mortality studies that the current standard is not adequately protective.”

Local communities throughout the country need to determine when to close schools or at least keep kids inside, Liu says, as well as when to advise people to close windows and turn on air purifiers. Good masks — N95 and KN95 — can help too (yes, masks that block viruses can also block particulate matter).

City, county and state governments also need to prepare the health care system to respond to increased asthma issues, Liu says. Some states are starting to respond. In 2017, for example, the Minnesota Pollution Control Agency increased its air quality monitoring stations around the state from two to 18. The agency is also working with the National Weather Service, the Minnesota Department of Health and the Minnesota Department of Transportation to better communicate air quality warnings.

Minnesota, after experiencing a rise in smoky summer days, has added extra air quality monitoring stations to improve local forecasts.

MINNESOTA POLLUTION CONTROL AGENCY

In the meantime, much more research is needed into the human health implications of increasing wildfire smoke, Buchholz says, as well as the chemical interactions in the atmosphere, how climate is changing fires, how fires change year after year, and how they impact the atmosphere, not to mention how different trees, buildings and other fuels affect particulate matter.

“Wildfires are perhaps one of the most visible ways that [climate change] is linked to health,” Stowell says. And the reality is, she says, “we’re going to see it remain as bad or worse for a while.”

Smoke gets on the brain

Health impact studies of air pollution, including wildfire smoke, have mostly focused on the lungs. But toxicologist Matthew Campen of the University of New Mexico in Albuquerque is looking at the brain.

In a study of the inflammatory effects of smoke PM2.5 on the brains of mice, Campen and colleagues found that inflammation in the lungs was modest compared with the “profound” inflammation in the brain, Campen says. Given what’s known about how damaging smoke can be in the lungs, to find even greater effects on the brain is troubling, he says.

The inflammatory effect on the mice’s brains was almost immediate, within 24 hours of exposure, the researchers reported in the March Toxicological Sciences. The particulates enter the body through the respiratory system, get in the blood, and are small enough to cross the blood-brain barrier and start affecting the brain. Inflammation has been linked with dementia in older people and neurodevelopmental issues in younger people, plus mood disorders like anxiety and depression, Campen says.

“I’m hoping that our study with mice spurs … epidemiologists to take a look,” he says. “The effects we see are much stronger and more worrisome than what we see in the lungs,” he says, but we don’t know yet at what PM2.5 levels the danger begins. “We need to explore this more rigorously.” — Megan Sever

A version of this article appears in the June 18, 2022 issue of Science News.

CITATIONS

R.R. Buchholz et al. New seasonal pattern of pollution emerges from changing North American wildfires. Nature Communications. Vol. 13. April 19, 2022. doi:10.1038/s41467-022-29623-8.

J.D. Stowell et al. Asthma exacerbation due to climate change-induced wildfire smoke in the Western US. Environmental Research Letters. Vol. 17. January 2022. doi:10.1088/1748-9326/ac4138.

R. Aguilera et al. Fine particles in wildfire smoke and pediatric respiratory health in California. Pediatrics. Vol. 147. April 2021. doi:10.1542/peds.2020-027128.

A.P. Brown et al. Long-term effects of wildfire smoke exposure during early life on the nasal epigenome in rhesus macaques. Environment International. Vol. 158. January 2022. doi:10.1016/j.envint.2021.106993.

D. Scieszka et al. Neuroinflammatory and neurometabolomic consequences from inhaled wildfire smoke-derived particulate matter in the western United States. Toxicological Sciences. Vol. 186. March 2022. doi:10.1093/toxsci/kfab147.


Related Stories

EARTH
The worst wildfires can send smoke high enough to affect the ozone layer
By Megan SeverAugust 8, 2019

CLIMATE
Wildfire smoke may ramp up toxic ozone production in cities
By Ariana RemmelDecember 8, 2021

WAR IS ECOCIDE

Russia’s invasion could cause long-term harm to Ukraine’s prized soil
Physical and chemical damage to farmland could linger for years

A team works to destroy an unexploded missile in a field near Hryhorivka, Ukraine. War damage done to the country’s fertile soil could affect agriculture for years.
DIMITAR DILKOFF/AFP VIA GETTY IMAGES

By Rebecca Dzombak
JUNE 21,2022

By now, wheat planted late last year waves in fields across Ukraine. Spring crops of sunflowers and barley are turning swaths of dark earth into a fuzz of bright green. But with Russia’s war being waged in some of the most fertile regions of Ukraine, uncertainty looms over summer harvesting.

Ukrainian farmers braved a war zone to carry out close to 80 percent of spring planting, covering roughly 14 million hectares. Still, Russia’s invasion has raised fears that not only are this year’s crop yields in jeopardy, but also that Ukraine’s agricultural output could be diminished for years. At the root of this worry, in part, is how warfare impacts soil.

Ukraine is home to some of the most fertile soil in the world, making it a top global producer of cereals, such as wheat and maize, as well as seed oils like sunflower oil. The country’s exports feed millions of people from Europe and Africa to China and Southeast Asia.

With the war in its fourth month, the Food and Agriculture Organization of the United Nations estimates at least 20 percent of Ukraine’s crops planted in winter will remain unharvested or went unplanted. And despite farmers’ best efforts, many spring crops went unplanted. This summer’s winter wheat harvest could be cut approximately in half (a loss of about 2 million hectares) and sunflower products cut by a third.

With warfare able to degrade and contaminate soil for years, crop yields — and the people who depend on them — could suffer long after a cease-fire.

“In many ways, the welfare of the soil system in postwar nations is really intricately tied to the welfare of the people,” says soil scientist Asmeret Asefaw Berhe of University of California, Merced. “And in many ways, it’s going to dictate their long-term future, too.”
Super soil

A type of grassland soil called chernozem covers nearly two-thirds of agricultural lands in Ukraine. Meaning “black earth,” chernozem is a Ukrainian and Russian word that describes highly fertile soils distinguished by one to two meters of dark, rich organic matter. Over the last 10,000 years, it accumulated along the Eurasian steppes, slowly building up as a black bed atop fine, windblown sediments called loess, which coated the region as the glaciers retreated. At the same time in North America, grassland soils similar to chernozems called mollisols formed over the Great Plains, creating twin breadbaskets.

Chernozem (shown) is nutrient-rich dark soil that is essential for agriculture in Ukraine.

SOIL MUSEUM/SOIL EDUCATION CENTER/UNIVERSITY OF AGRICULTURE IN KRAKÓW, COURTESY OF PIOTR PACANOWSKI

Chernozems are rich in elements that plants need to grow, such as nitrogen, potassium and calcium. Those nutrients come from organic matter and underlying loess. Chernozems also hit the sweet spot of clay content — just enough to help hold the soil together and cling onto nutrients but not so much that roots have a hard time penetrating the ground.

In their natural state, chernozems come preloaded with vitamins and minerals, like a super-smoothie of plant nutrition. “Plants growing in these soils are lucky,” Berhe says. “They’re growing in an environment that has everything they need to grow, with or without additional fertilizers or extra supplements.”
Bombing fields

There’s a term for what war does to soil: bombturbation. It’s grim wordplay on the natural process of bioturbation — earthworms and other animals stirring up soil. In this case, though, exploding bombs and artillery fire fling clods of dirt and dig craters. Joseph Hupy, a soil geomorphologist at Purdue University in West Lafayette, Ind., coined the term with coauthor Randall Schaetzl in 2006 while studying soils’ battlefield scars.

At France’s World War I battlefield at Verdun, Hupy dug meter-long trenches with a backhoe across bomb craters and in their vicinity, looking for signs of disturbance. He wanted to understand how the landscape recovered, with or without human help. He found decades-old chaos beneath the surface. His cross sections revealed rubble, chunks of limestone bedrock embedded in a slurry of sandy soil and organics. That chaos was reflected on the surface too: Where there were craters, water flow had changed, leading to different patterns of vegetation growth, Hupy and a colleague reported in 2012 in Geomorphology. Because of shifts in hydrology and a lack of human management, the landscape reverted from agriculture to forest. “It’s a completely new ecosystem,” he says.

Shelling left a deep crater in a field on the outskirts of Kharkiv, Ukraine. This type of damage can change vegetation growth.

BERNAT ARMANGUE/AP PHOTO

Hupy noted similar changes at Vietnam’s Khe Sanh, which the United States heavily bombed in 1968. Aerial images of Ukrainian battle zones show pockmarked fields, reminiscent of the sites Hupy studied in Vietnam. Problems in Ukrainian soil may not be limited to the surface. Even if farmers smooth over the top of the soil, underground rubble can act like a barrier or sluice for water, which could make it harder to grow crops.

When there’s a highly compacted area beneath where the teeth of a plow can go, that impermeable layer of soil “can create standing water, and all other sorts of problems from an agricultural standpoint,” Hupy says.

Trouble with tanks

Bombs may leave some of the most obvious impacts, but they aren’t the only thing that can physically disturb soil. Soggy, thawing soils in Ukraine bogged down Russian tanks as if a metaphor of resistance: The land itself was fighting back. But what’s bad for invading tanks is also bad for the soil. When tanks roll over a field, their weight makes soil clump and stick together. Wet soil can compound the problem, exacerbating compaction. And chernozems are particularly vulnerable to compaction: With their thick layer of organic matter, they’re fluffy and light.

Compaction can temporarily cut crop yields by anywhere from 10 percent to nearly 60 percent because it makes it more difficult for roots to reach nutrients and prevents water and fertilizers from penetrating the soil. A study in International Agrophysics on compaction and crop yields in Eastern European chernozems, for instance, found chernozem-grown barley plants yielded about half the amount of crops when highly compacted. Earlier work suggested compaction could impact yields for up to five years if it reached deep enough into the chernozem. For all but the worst compaction, though, several seasons of typical planting will help heal the land, says soil scientist DeAnn Presley of Kansas State University in Manhattan.

“If you had tank traffic go right through a crop field, the farmer is probably going to go out and just till up the field pretty well after the conflict is over. And you may never see that [compaction] again,” Presley says. Compaction “will definitely look terrible and you’ll have yield losses, but I don’t think they’ll be forever or permanent.”

Outside Kharkiv, a destroyed Russian tank sits in a field. Tanks can pack down the fluffy chernozem soil and that compaction can cut crop yields.

DIMITAR DILKOFF/AFP VIA GETTY IMAGES

A study of military vehicles rolling over prairie soils outside Fort Riley, Kan., revealed it took as little as one year for dry soil to recover from being compacted, but up to four years for wet soil to recover, both without tilling, scientists reported in Soil Science Society of America Journal. Tank traffic can alter the community of soil microbes and reduce the abundance of other organisms, like soil-aerating earthworms, for several years as well, members of the same team reported in Applied Soil Ecology.

Chernozems’ fluffiness might put it at greater risk of compaction, but it can also help the soil spring back afterward, helping prevent it from becoming a longer-term problem. Hardy, deep-rooting plants like some of Ukraine’s native grasses could also loosen stubborn soils, Presley says, but it would take years.

Chemical contamination

Countering compaction can be a relatively quick fix; not so with chemical contamination. Fuel spills, spent ammunition, chemical weapons, and animal and human remains can all foul the soil, sometimes for decades or longer.

Potentially toxic metals such as lead, arsenic and mercury can leach out of ammunition and weaponry and into the soil. Pollutants from warfare are still found in soils contaminated by wars as old as World War I, researchers reported in 2020 in Sustainability. At Ypres, a World War I battlefield in Belgium, scientists estimate that shells and artillery left more than 2,800 metric tons of copper in the top half-meter of soil. In Iran, soils remain laced with mercury and chlorine from the 1980s.

As crops grow, they can draw up these potentially toxic elements. Other elements, such as zinc and nickel, can severely stunt crop growth, says Ganga Hettiarachchi, a soil chemist also at Kansas State University. But soil contamination can be a hidden danger. If it doesn’t damage the plants, there may be no way of knowing if the soil is contaminated without careful testing, she says.

In some ways, chernozems are well-equipped to stop contaminants in their tracks in a matter of months. The soil’s organic matter and clay can trap toxic elements before they can enter a plant, sucking out contaminants – even in a matter of days in optimal lab conditions, Hettiarachchi says. But in real life, many chernozems are also slightly acidic, which can let those elements stay in a form that plants can take up for months before being stopped.

Because of this uncertainty, every potentially contaminated patch of soil must be checked to see if crops can be safely grown. “We have to monitor the soil and the crops as well, at least until we understand what’s going on,” says Hettiarachchi.

Potentially toxic metals can leach out of munitions, such as this rocket a team is working to remove from a field in Borodianka, Ukraine. Ridding the country of this weaponry could take decades.

CHRISTOPHER FURLONG/GETTY IMAGES

For some elements, farmers could remediate by planting plants known to extract those elements over time, says Hettiarachchi, but that would require several years of planting. Other options include altering the soils’ pH to lock away metals or adding extra fertilizer, which can also immobilize potentially toxic elements. But even after remediation occurs, farmers must test to see if soil conditions are keeping the contaminants locked away, or if the war is coming back to haunt them from the ground.

Depending on the extent of contamination, “it might not be possible for Ukrainian farmers to avoid growing in contaminated soils,” she says. Soil testing and time will tell.
Looking toward the future

With Russia’s bombardment of Ukraine still ongoing, the effect on the country’s soil is still uncertain. There are some hints, though. This isn’t the first time the Donbas region — a disputed area in eastern Ukraine — has come under fire. Russian-backed separatists attacked it beginning in 2014 too.

Scientists working in the Donbas to improve soil health there have faced a litany of challenges: The region’s agriculture already suffered from degradation due to irrigation waters polluted by coal mines, researchers reported in 2020 in Mineralogical Journal. Decades of intense farming had also taken a toll. Since 2014, conflict has exacerbated those problems, creating new issues and hampering scientists’ ability to help.

The region’s “chernozems have suffered and are experiencing irreparable military degradation,” Ukrainian soil scientists and a lawyer wrote in 2021 in Scientific Papers. Series A. Agronomy. “It is easy to predict [the degradation of chernozems], but very difficult to overcome.”

Even as the fighting has been concentrated in eastern Ukraine, this assessment now may apply to a far broader swath of the country. “Our unique soils, chernozems, are in unprecedented conditions,” representatives from Ukraine’s Institute for Soil Science and Agrochemistry Research wrote Science News in an e-mail. “The extent of the damage has yet to be ascertained. In fact, we have just begun to work in this direction … in difficult military conditions.”

CITATIONS

J.P. Hupy and R.J. Schaetzl. Introducing “bombturbation,” a singular type of soil disturbance and mixing. Soil Science, Vol. 171, November 2006, p. 823. doi: 10.1097/01.ss.0000228053.08087.19.

J.P. Hupy and R.J. Schaetzel. Soil development on the WWI battlefield of Verdun, France. Geoderma. Vol. 145, May 2008, p. 37. doi: 10.1016/j.geoderma.2008.01.024.

J.P. Hupy and T. Koehler. Modern warfare as a significant form of zoogeomorphic disturbance upon the landscape. Geomorphology. Vol. 157-158, July 2012, p. 169. doi: 10.1016/j.geomorph.2011.05.024.

M.F. Nawaz, G. Bourrié and F. Trolard. Soil compaction impact and modelling. A review. Agronomy for Sustainable Development. Vol. 33, January 31, 2012, p. 291. doi: 10.1007/s13593-011-0071-8.

J. Lipiec et al. Effect of soil compaction on root growth and crop yield in Central and Eastern Europe. International Agrophysics. Vol. 17, 2003, p. 61. YADDA: bwmeta1.element.agro-article-486b0405-0d68-4f7a-9782-3fd0415d847e.

P.S. Althoff, S.J. Thien and T.C. Todd. Primary and residual effects of Abrams tank traffic on prairie soil properties. Soil Science Society of America Journal. Vol. 74, November 2010, p. 2151. doi: 10.2136/sssaj2009.0091.

P.S. Althoff et al. Response of soil microbial and invertebrate communities to tracked vehicle disturbance in tallgrass prairie. Applied Soil Ecology. Vol. 43, September 2009, p. 122. doi: 10.1016/j.apsoil.2009.06.011.

V.A. Korolev. Specific features of water permeability in virgin and cultivated chernozems. Eurasian Soil Science. Vol. 40, September 2007, p. 962. doi: 10.1134/S1064229307090062.

P. Broomandi et al. Soil contamination in areas impacted by military activity: A critical review. Sustainability. Vol. 12, 2020, p. 9002. doi: 10.3390/su12219002.

M. Van Meirvenne et al. Could shelling in the First World War have increased copper concentrations in the soil around Ypres? European Journal of Soil Science. Vol. 59, April 2008, p. 372. doi: 10.1111/j.1365-2389.2007.01014.x.

N.O. Ryzhenko, S.V. Kavetsky and V.M. Kavetsky. Heavy metals (Cd, Pb, Zn, and Cu) uptake by spring barley in polluted soils. Polish Journal of Soil Science. Vol. 48, 2016, p. 111. doi: 10.17951/pjss.2015.48.1.111.

V.O. Pryvalov, O.A. Panova and A.V. Pryvalov. Geology in environmental management issues of the Donbas within the context of its forthcoming restoration. Mineralogical Journal. Vol. 42, 2020, p. 76. doi: 10.15407/mineraljournal.42.01.076.

S. Pozniak, N. Havrysh and T. Yamelynets. Chernozems of Ukraine and its evolution under the influence of anthropogenic factors. Scientific Papers. Series A. Agronomy.Vol. 64, 2021, p. 156.

J.P. Hupy. Khe Sanh, Vietnam: Examining the long-term impacts of warfare on the physical landscape. Chapter in Modern Military Geography. Routledge, 2010.

Meteorite Discovery Challenges Our Understanding of How Mars Formed

Sirenum Fossae on Mars. (NASA)


MICHELLE STARR
20 JUNE 2022

A small chunk of rock that once broke away from Mars and found its way to Earth may hold clues that reveal surprising details about the red planet's formation.

A new analysis of the Chassigny meteorite, which fell to Earth in 1815, suggests that the way Mars obtained its volatile gasses – such as carbon, oxygen, hydrogen, nitrogen, and noble gasses – contradicts our current models about how planets form.

Planets are born, according to current models, from leftover star stuff. Stars form from a nebular cloud of dust and gas when a dense clump of material collapses under gravity. Spinning, it spools in more material from the cloud around it to grow.

This material forms a disk, whirling around the new star. Within that disk, dust and gas begin to clump together in a process that grows a baby planet. We've seen other baby planetary systems forming in this way, and evidence in our own Solar System suggests it formed the same way, around 4.6 billion years ago.

But how and when certain elements were incorporated into the planets has been tricky to piece together.

According to current models, volatile gasses are taken up by a molten, forming planet from the solar nebula. Because the planet is so hot and mushy at this stage, these volatiles are slurped into the global magma ocean that is the forming planet, before later being partially outgassed into the atmosphere as the mantle cools.

Later, more volatiles are delivered via meteorite bombardment – volatiles bound up in carbonaceous meteorites (called chondrites) are released when these meteorites break apart on introduction to the planet.

So, the interior of a planet should reflect the composition of the solar nebula, while its atmosphere should reflect mostly the volatile contribution of meteorites.

We can tell the difference between these two sources by looking at ratios of isotopes of noble gasses, particularly krypton.

And, because Mars formed and solidified relatively quickly in about 4 million years, compared to up to 100 million years for Earth, it's a good record for those very early stages of the planetary formation process.

"We can reconstruct the history of volatile delivery in the first few million years of the Solar System," said geochemist Sandrine Péron, formerly of the University of California Davis, now at ETH Zurich.

That is, of course, only if we can access the information we need – and this is where the Chassigny meteorite is a gift from space.

Its noble gas composition differs from that of the Martian atmosphere, suggesting that the chunk of rock broke away from the mantle (and flung into space, precipitating its arrival at Earth), and is representative of the planetary interior and thus the solar nebula.

Krypton is quite tricky to measure, however, so the precise isotope ratios have eluded measurement. However, Péron and her colleague, fellow geochemist Sujoy Mukhopadhyay of UC Davis, employed a new technique using the UC Davis Noble Gas Laboratory to perform a new, precise measurement of krypton in the Chassigny meteorite.

And this is where it got really weird. The krypton isotope ratios in the meteorite are closer to those associated with chondrites. Like, remarkably closer.

"The Martian interior composition for krypton is nearly purely chondritic, but the atmosphere is solar," Péron said. "It's very distinct."

This suggests that meteorites were delivering volatiles to Mars much earlier than scientists previously thought, before the solar nebula had been dissipated by solar radiation.

The order of events, therefore, would be that Mars acquired an atmosphere from the solar nebula after its global magma ocean cooled; otherwise, the chondritic gasses and the nebular gasses would be much more mixed than what the team observed.

However, this presents another mystery. When solar radiation did eventually burn away the remnants of the nebula, it ought to have burnt away the nebular atmosphere of Mars, too. This means that the atmospheric krypton present later must have been preserved somewhere; perhaps, the team suggested, in polar ice caps.

"However, that would require Mars to have been cold in the immediate aftermath of its accretion," Mukhopadhyay said.

"While our study clearly points to the chondritic gasses in the Martian interior, it also raises some interesting questions about the origin and composition of Mars' early atmosphere."

The team's research has been published in Science.

It's Worse Than We Thought: Food Miles Account For a Sickening Amount of Emissions

(Massimo Ravera/Getty Images)

JACINTA BOWLER
21 JUNE 2022

In many places around the world, grocery store produce aisles are a delightful array of colors, even in the depths of winter, when it feels like not much could grow outside.

But this year-round variety has a real cost on the planet, with a new study finding that 'food miles' account for 19 percent of all food emissions – three times more than previously thought.

Even worse, with only 12.5 percent of the world's population, high income countries generate 46 percent of the world's food-mile emissions.

"Our study estimates global food systems, due to transport, production, and land use change, contribute about 30 percent of total human-produced greenhouse gas emissions. So, food transport – at around six percent – is a sizable proportion of overall emissions," says the study's lead author, University of Sydney environmental modeling researcher Mengyu Li.

"Food transport emissions add up to nearly half of direct emissions from road vehicles."

You can imagine that modeling the entire food chain around the world is a difficult process, and most papers in the past have either looked at specific countries, or specific products (for example tomato ketchup or beef), but this isn't able to scale out to give a very good overall picture of what's happening.

"Although carbon emissions associated with food production are well documented," the team write in their new paper, "the carbon footprint of the global trade of food, accounting for the entire food supply chain, has not been comprehensively quantified."

Instead, the researchers used a framework called FoodLab to take in 74 countries, 37 economic sectors – like livestock, coal, and fruit and veg – and four transportation modes to create a model that incorporates the entire global supply-chain network.

The results are not exactly comforting. Food transport alone contributes 3 gigatonnes of emissions annually – equivalent to 19 percent of all food-related emissions, including land use.

The researchers also looked at what would happen if everyone just ate locally. The team worked out that it would reduce food miles emissions by 0.27 gigatonnes (0.24 gigatonnes for high-income countries alone!), and food production emissions by 0.11 gigatonnes.

Unfortunately, eating entirely locally is unrealistic, as some places aren't able to grow their own food, but it gives a good suggestion of where we can go from here.

"We tend to interpret information around us in simplistic terms, like 'meat is bad and vegetables are good' but we wanted a much more comprehensive picture," University of Sydney nutritional ecologist David Raubenheime told The Guardian.

"Our study shows that in addition to shifting towards a plant-based diet, eating locally is ideal, especially in affluent countries," he added.

The researchers suggest that in this case, consumers have the most chance of causing widespread change. So, for those of us in high income countries, individually choosing the local or seasonal option is one of the best ways forward.

This is particularly important with fruit and vegetables, as they need to be refrigerated to be sent around the world, creating even more emissions.

Sometimes grocery stores will include a country-of-origin label to assist in more local selections. It's even better if you know that the crop was grown in your state or area of the country.

The other issue is that many of us are now used to being able to buy avocados, asparagus, berries, and citrus at any time of year.

"One example is the habit of consumers in affluent countries demanding unseasonal foods year-round, which need to be transported from elsewhere," says Raubenheime.

"Eating local seasonal alternatives, as we have throughout most of the history of our species, will help provide a healthy planet for future generations."

You might be a little fuzzy with what fruits and vegetables are available in which seasons, so check out this link if you're in the US and want a refresher. There's other tips as well, like choosing frozen or canned vegetables when not in season, as these are able to be stored when they are most plentiful.

The research has been published in Nature Food.

Olive trees were first domesticated 7,000 years ago, study finds

Researchers: 'Earliest evidence for cultivation of a fruit tree'

Date: June 16, 2022

Source: Tel-Aviv University

Summary:

A new study has unraveled the earliest evidence for domestication of a fruit tree, researchers report. The researchers analyzed remnants of charcoal from the Chalcolithic site of Tel Zaf in the Jordan Valley and determined that they came from olive trees. Since the olive did not grow naturally in the Jordan Valley, this means that the inhabitants planted the tree intentionally about 7,000 years ago.

FULL STORY

A joint study by researchers from Tel Aviv University and the Hebrew University unraveled the earliest evidence for domestication of a fruit tree. The researchers analyzed remnants of charcoal from the Chalcolithic site of Tel Zaf in the Jordan Valley and determined that they came from olive trees. Since the olive did not grow naturally in the Jordan Valley, this means that the inhabitants planted the tree intentionally about 7,000 years ago.

The groundbreaking study was led by Dr. Dafna Langgut of the Jacob M. Alkow Department of Archaeology & Ancient Near Eastern Cultures and the Steinhardt Museum of Natural History at Tel Aviv University. The charcoal remnants were found in the archaeological excavation directed by Prof. Yosef Garfinkel of the Institute of Archaeology at the Hebrew University. The findings were published in the journal Scientific Reports from the publishers of Nature.

Dr. Langgut: "I am the head of the Laboratory of Archaeobotany & Ancient Environments, which specializes in microscopic identification of plant remains. Trees, even when burned down to charcoal, can be identified by their anatomic structure. Wood was the 'plastic'of the ancient world. It was used for construction, for making tools and furniture, and as a source of energy. That's why identifying tree remnants found at archaeological sites, such as charcoal from hearths, is a key to understanding what kinds of trees grew in the natural environment at the time, and when humans began to cultivate fruit trees."

In her lab, Dr. Langgut identified the charcoal from Tel Zaf as belonging to olive and fig trees. "Olive trees grow in the wild in the land of Israel, but they do not grow in the Jordan Valley," she says. "This means that someone brought them there intentionally -- took the knowledge and the plant itself to a place that is outside its natural habitat. In archaeobotany, this is considered indisputable proof of domestication, which means that we have here the earliest evidence of the olive's domestication anywhere in the world. I also identified many remnants of young fig branches. The fig tree did grow naturally in the Jordan Valley, but its branches had little value as either firewood or raw materials for tools or furniture, so people had no reason to gather large quantities and bring them to the village. Apparently, these fig branches resulted from pruning, a method still used today to increase the yield of fruit trees."

The tree remnants examined by Dr. Langgut were collected by Prof. Yosef Garfinkel of the Hebrew University, who headed the dig at Tel Zaf. Prof. Garfinkel: "Tel Zaf was a large prehistoric village in the middle Jordan Valley south of Beit She'an, inhabited between 7,200 and 6,700 years ago. Large houses with courtyards were discovered at the site, each with several granaries for storing crops. Storage capacities were up to 20 times greater than any single family's calorie consumption, so clearly these were caches for storing great wealth. The wealth of the village was manifested in the production of elaborate pottery, painted with remarkable skill. In addition, we found articles brought from afar: pottery of the Ubaid culture from Mesopotamia, obsidian from Anatolia, a copper awl from the Caucasus, and more."

Dr. Langgut and Prof. Garfinkel were not surprised to discover that the inhabitants of Tel Zaf were the first in the world to intentionally grow olive and fig groves, since growing fruit trees is evidence of luxury, and this site is known to have been exceptionally wealthy.

Dr. Langgut: "The domestication of fruit trees is a process that takes many years, and therefore befits a society of plenty, rather than one that struggles to survive. Trees give fruit only 3-4 years after being planted. Since groves of fruit trees require a substantial initial investment, and then live on for a long time, they have great economic and social significance in terms of owning land and bequeathing it to future generations -- procedures suggesting the beginnings of a complex society. Moreover, it's quite possible that the residents of Tel Zaf traded in products derived from the fruit trees, such as olives, olive oil, and dried figs, which have a long shelf life. Such products may have enabled long-distance trade that led to the accumulation of material wealth, and possibly even taxation -- initial steps in turning the locals into a society with a socio-economic hierarchy supported by an administrative system."

Dr. Langgut concludes: "At the Tel Zaf archaeological site we found the first evidence in the world for the domestication of fruit trees, alongside some of the earliest stamps -- suggesting the beginnings of administrative procedures. As a whole, the findings indicate wealth, and early steps toward the formation of a complex multilevel society, with the class of farmers supplemented by classes of clerks and merchants."

Journal Reference:Dafna Langgut, Yosef Garfinkel. 7000-year-old evidence of fruit tree cultivation in the Jordan Valley, Israel. Scientific Reports, 2022; 12 (1) DOI: 10.1038/s41598-022-10743-6

Researchers reconstruct the genome of centuries-old E. coli using fragments extracted from an Italian mummy

Date:June 16, 2022

Source:McMaster University

Summary: 

Researchers have identified and reconstructed the first ancient genome of E. coli, using fragments extracted from the gallstone of a 16th century mummy.

FULL STORY

An international team led by researchers at McMaster University, working in collaboration with the University of Paris Cité, has identified and reconstructed the first ancient genome of E. coli, using fragments extracted from the gallstone of a 16th century mummy.

The discovery is published online today in the journal Communications Biology.

E. coli is a major public health concern, causing significant death and morbidity, yet is not a source of pandemics. It is known as a commensal, a bacteria that resides within us and can act asan opportunistic pathogen infecting its host during periods of stress, underlying disease or immunodeficiency.

Its full evolutionary history remains a mystery, including when it acquired novel genes and antibiotic resistance, say researchers.

Unlike well-documented pandemics such as the Black Death, which lingered for centuries and killed as many as 200 million people worldwide, there are no historical records of deaths caused by commensals such as E. coli, though the impact on human health and mortality was likely tremendous.

"A strict focus on pandemic-causing pathogens as the sole narrative of mass mortality in our past misses the large burden that stems from opportunistic commmensals driven by the stress of lives lived," says evolutionary geneticist Hendrik Poinar, who is director of McMaster's Ancient DNA Centre and a principal investigator at the university's Michael G. DeGroote Institute for Infectious Disease Research.

Modern E. coli iscommonly found in the intestines of healthy people and animals. While most forms are harmless, some strains are responsible for serious, sometimes fatal food poisoning outbreaks and bloodstream infections. The hardy and adaptable bacterium is recognized as especially resistant to treatment.

Having the genome of a 400-year-old ancestor to the modern bacterium provides researchers a point of comparison for studying how it has evolved and adapted since that time.

The mummified remains used for the new study come from a group of Italian nobles whose well-preserved bodies were recovered from the Abbey of Saint Domenico Maggiore in Naples in 1983.

For the study, the researchers conducted a detailed analysis of one of the individuals, Giovani d'Avalos. A Neapolitan noble from the Renaissance period, he was 48 when he died in 1586, and thought to have suffered from chronic inflammation of the gallbladder due to gallstones.

"When we were examining these remains, there was no evidence to say this man had E. coli. Unlike an infection like smallpox, there are no physiological indicators. No one knew what it was," explains lead author of the study, George Long, a graduate student of bioinformatics at McMaster who conducted the analysis with co-lead author Jennifer Klunk, a former graduate student in the university's Department of Anthropology.

The technological feat is particularly remarkable because E. coli is both complex and ubiquitous, living not only in the soil but also in our own microbiomes. Researchers had to meticulously isolate fragments of the target bacterium, which had been degraded by environmental contamination from many sources. They used the recovered material to reconstruct the genome.

"It was so stirring to be able to type this ancient E. coli and find that while unique it fell within a phylogenetic lineage characteristic of human commensals that is today still causing gallstones," says Erick Denamur, the leader of the French team that was involved in the strain characterisation.

"We were able to identify what was an opportunistic pathogen, dig down to the functions of the genome, and to provide guidelines to aid researchers who may be exploring other, hidden pathogens," says Long.

The work was done in collaboration with researchers at the University of Pisa and the Université Paris Cité /French Institute of Medical Research (INSERM) and is funded by the Canadian Institute of Advanced Research.

Journal Reference:George S. Long, Jennifer Klunk, Ana T. Duggan, Madeline Tapson, Valentina Giuffra, Lavinia Gazzè, Antonio Fornaciari, Sebastian Duchene, Gino Fornaciari, Olivier Clermont, Erick Denamur, G. Brian Golding, Hendrik Poinar. A 16th century Escherichia coli draft genome associated with an opportunistic bile infection. Communications Biology, 2022; 5 (1) DOI: 10.1038/s42003-022-03527-1

Once seen as fleeting, a new solar tech proves its lasting power

30-year perovskite solar cells and the new approach to testing them for the long  haul

Date:June 16, 2022Source:Princeton University, Engineering School

Summary:

Researchers have developed the first perovskite solar cell with a commercially viable lifetime, marking a major milestone for an emerging class of renewable energy technology. The team projects their device can perform above industry standards for around 30 years, far more than the 20 years used as a threshold for viability for solar cells.

FULL STORY

Princeton Engineering researchers have developed the first perovskite solar cell with a commercially viable lifetime, marking a major milestone for an emerging class of renewable energy technology. The team projects their device can perform above industry standards for around 30 years, far more than the 20 years used as a threshold for viability for solar cells.

The device is not only highly durable, it also meets common efficiency standards. It is the first of its kind to rival the performance of silicon-based cells, which have dominated the market since their introduction in 1954.

Perovskites are semiconductors with a special crystal structure that makes them well suited for solar cell technology. They can be manufactured at room temperature, using much less energy than silicon, making them cheaper and more sustainable to produce. And whereas silicon is stiff and opaque, perovskites can be made flexible and transparent, extending solar power well beyond the iconic panels that populate hillsides and rooftops across America.

But unlike silicon, perovskites are notoriously fragile. Early perovskite solar cells (PSC), created between 2009 and 2012, lasted only minutes. The projected lifetime of the new device represents a five-fold increase over the previous record, set by a lower efficiency PSC in 2017. (That device operated under continuous illumination at room temperature for one year. The new device would operate for five years under similar lab conditions.)

The Princeton team, led by Lynn Loo, the Theodora D. '78 and William H. Walton III '74 Professor in Engineering, revealed their new device and their new method for testing such devices in a paper published June 16 in Science.

Loo said the record-setting design has highlighted the durable potential of PSCs, especially as a way to push solar cell technology beyond the limits of silicon. But she also pointed past the headline result to her team's new accelerated aging technique as the work's deeper significance.

"We might have the record today," she said, "but someone else is going to come along with a better record tomorrow. The really exciting thing is that we now have a way to test these devices and know how they will perform in the long term."

Due to perovskites' well-known frailty, long-term testing hasn't been much of a concern until now. But as the devices get better and last longer, testing one design against another will become crucial in rolling out durable, consumer-friendly technologies.

"This paper is likely going to be a prototype for anyone looking to analyze performance at the intersection of efficiency and stability," said Joseph Berry, a senior fellow at the National Renewable Energy Laboratory who specializes in the physics of solar cells and who was not involved in this study. "By producing a prototype to study stability, and showing what can be extrapolated [through accelerated testing], it's doing the work everyone wants to see before we start field testing at scale. It allows you to project in a way that's really impressive."

While efficiency has accelerated at a remarkable pace over the past decade, Berry said, the stability of these devices has improved more slowly. For them to become widespread and rolled out by industry, testing will need to become more sophisticated. That's where Loo's accelerated aging process comes in.

"These kinds of tests are going to be increasingly important," Loo said. "You can make the most efficient solar cells, but it won't matter if they aren't stable."

How they got here

Early in 2020, Loo's team was working on various device architectures that would maintain relatively strong efficiency -- converting enough sunlight to electric power to make them valuable -- and survive the onslaught of heat, light and humidity that bombard a solar cell during its lifetime.

Xiaoming Zhao, a postdoctoral researcher in Loo's lab, had been working on a number of designs with colleagues. The efforts layered different materials in order to optimize light absorption while protecting the most fragile areas from exposure. They developed an ultra-thin capping layer between two crucial components: the absorbing perovskite layer and a charge-carrying layer made from cupric salt and other substances. The goal was to keep the perovskite semiconductor from burning out in a matter of weeks or months, the norm at that time.

It's hard to comprehend how thin this capping layer is. Scientists use the term 2D to describe it, meaning two dimensions, as in something that has no thickness at all. In reality, it's merely a few atoms thick -- more than a million times smaller than the smallest thing a human eye can see. While the idea of a 2D capping layer isn't new, it is still considered a promising, emerging technique. Scientists at NREL have shown that 2D layers can greatly improve long-haul performance, but no one had developed a device that pushed perovskites anywhere close to the commercial threshold of a 20-year lifetime.

Zhao and his colleagues went through scores of permutations of these designs, shifting minute details in the geometry, varying the number of layers, and trying out dozens of material combinations. Each design went into the light box, where they could irradiate the sensitive devices in relentless bright light and measure their drop in performance over time.

In the fall of that year, as the first wave of the pandemic subsided and researchers to returned to their labs to tend to their experiments in carefully coordinated shifts, Zhao noticed something odd in the data. One set of the devices still seemed to be operating near its peak efficiency.

"There was basically zero drop after nearly half a year," he said.

That's when he realized he needed a way to stress test his device faster than his real-time experiment allowed.

"The lifetime we want is about 30 years, but you can't take 30 years to test your device," Zhao said. "So we need some way to predict this lifetime within a reasonable timeframe. That's why this accelerated aging is very important."

The new testing method speeds up the aging process by illuminating the device while blasting it with heat. This process speeds up what would happen naturally over years of regular exposure. The researchers chose four aging temperatures and measured results across these four different data streams, from the baseline temperature of a typical summer day to an extreme of 230 degrees Fahrenheit, higher than the boiling point of water.

They then extrapolated from the combined data and forecast the device's performance at room temperature over tens of thousands of hours of continuous illumination. The results showed a device that would perform above 80 percent of its peak efficiency under continuous illumination for at least five years at an average temperature of 95 degrees Fahrenheit. Using standard conversion metrics, Loo said that's the lab equivalent of 30 years of outdoor operation in an area like Princeton, NJ.

Berry of NREL concurred. "It's very credible," he said. "Some people are still going to want to see it play out. But this is much more credible science than a lot of other attempts at forecasting."

The Michael Jordan of solar cells

Perovskite solar cells were pioneered in 2006, with the first published devices following in 2009. Some of the earliest devices lasted only seconds. Others minutes. In the 2010s the device lifetimes grew to days and weeks and finally months. Then in 2017, a group from Switzerland published a groundbreaking paper on a PSC that lasted for one full year of continuous illumination.

Meanwhile, the efficiency of these devices has skyrocketed over the same period. While the first PSC showed a power-conversion efficiency of less than 4 percent, researchers boosted that metric nearly tenfold in as many years. It was the fastest improvement scientists had seen in any class of renewable-energy technology to date.

So why the push for perovskites? Berry said a combination of recent advances make them uniquely desirable: newly high efficiencies, an extraordinary "tunability" that allows scientists to make highly specific applications, the ability to manufacture them locally with low energy inputs, and now a credible forecast of extended life coupled with a sophisticated aging process to test a wide array of designs.

Loo said it's not that PSCs will replace silicon devices so much that the new technology will complement the old, making solar panels even cheaper, more efficient and more durable than they are now, and expanding solar energy into untold new areas of modern life. For example, her group recently demonstrated a completely transparent perovskite film (having different chemistry) that can turn windows into energy producing devices without changing their appearance. Other groups have found ways to print photovoltaic inks using perovskites, allowing formfactors scientists are only now dreaming up.

But the main advantage in the long run, according to both Berry and Loo: Perovskites can be manufactured at room temperature, whereas silicon is forged at around 3000 degrees Fahrenheit. That energy has to come from somewhere, and at the moment that means burning a lot of fossil fuels.

Berry added this: Because scientists can tune perovskite properties easily and broadly, they allow disparate platforms to work smoothly together. That could be key in wedding silicon with emerging platforms such as thin-film and organic photovoltaics, which have also made great progress in recent years.

"It's sort of like Michael Jordan on the basketball court," he said. "Great on its own, but it also makes all the other players better."


Journal Reference:Xiaoming Zhao, Tianran Liu, Quinn C. Burlingame, Tianjun Liu, Rudolph Holley, Guangming Cheng, Nan Yao, Feng Gao, Yueh-Lin Loo. Accelerated aging of all-inorganic, interface-stabilized perovskite solar cells. Science, 2022; DOI: 10.1126/science.abn5679

Engineers create single-step, all-in-one 3D printing method to make robotic materials

Advance shows promise for 'meta-bots' designed to deliver drugs or aid rescue missions

Date:June 16, 2022

Source:University of California - Los Angeles

Summary:

Engineers have developed a new design strategy and 3D printing technique to build robots in one single step. The breakthrough enabled the entire mechanical and electronic systems needed to operate a robot to be manufactured all at once by a new type of 3D printing process for engineered active materials with multiple functions (also known as metamaterials). Once 3D printed, a 'meta-bot' will be capable of propulsion, movement, sensing and decision-making.

A team of UCLA engineers and their colleagues have developed a new design strategy and 3D printing technique to build robots in one single step.

A study that outlined the advance, along with the construction and demonstration of an assortment of tiny robots that walk, maneuver and jump, was published in Science.

The breakthrough enabled the entire mechanical and electronic systems needed to operate a robot to be manufactured all at once by a new type of 3D printing process for engineered active materials with multiple functions (also known as metamaterials). Once 3D printed, a "meta-bot" will be capable of propulsion, movement, sensing and decision-making.

The printed metamaterials consist of an internal network of sensory, moving and structural elements and can move by themselves following programmed commands. With the internal network of moving and sensing already in place, the only external component needed is a small battery to power the robot.

"We envision that this design and printing methodology of smart robotic materials will help realize a class of autonomous materials that could replace the current complex assembly process for making a robot," said the study's principal investigator Xiaoyu (Rayne) Zheng, an associate professor of civil and environmental engineering, and of mechanical and aerospace engineering at the UCLA Samueli School of Engineering. "With complex motions, multiple modes of sensing and programmable decision-making abilities all tightly integrated, it's similar to a biological system with the nerves, bones and tendons working in tandem to execute controlled motions."

The team demonstrated the integration with an on-board battery and controller for the fully autonomous operation of the 3D printed robots -- each at the size of a finger nail. According to Zheng, who is also a member of the California NanoSystems Institute at UCLA, the methodology could lead to new designs for biomedical robots, such as self-steering endoscopes or tiny swimming robots, which can emit ultrasounds and navigate themselves near blood vessels to deliver drug doses at specific target sites inside the body.

These "meta-bots" can also explore hazardous environments. In a collapsed building, for example, a swarm of such tiny robots armed with integrated sensing parts could quickly access confined spaces, assess threat levels and help rescue efforts by finding people trapped in the rubble.

Most robots, no matter their size, are typically built in a series of complex manufacturing steps that integrate the limbs, electronic and active components. The process results in heavier weights, bulkier volumes and reduced force output compared to robots that could be built using this new method.

The key in the UCLA-led, all-in-one method is the design and printing of piezoelectric metamaterials -- a class of intricate lattice materials that can change shape and move in response to an electric field or create electrical charge as a result of physical forces.

The use of active materials that can translate electricity to motions is not new. However, these materials generally have limits in their range of motion and distance of travel. They also need to be connected to gearbox-like transmission systems in order to achieve desired motions.

By contrast, the UCLA-developed robotic materials -- each the size of a penny -- are composed of intricate piezoelectric and structural elements that are designed to bend, flex, twist, rotate, expand or contract at high speeds.

The team also presented a methodology to design these robotic materials so users could make their own models and print the materials into a robot directly.

"This allows actuating elements to be arranged precisely throughout the robot for fast, complex and extended movements on various types of terrain," said the study's lead author Huachen Cui, a UCLA postdoctoral scholar in Zheng's Additive Manufacturing and Metamaterials Laboratory. "With the two-way piezoelectric effect, the robotic materials can also self-sense their contortions, detect obstacles via echoes and ultrasound emissions, as well as respond to external stimuli through a feedback control loop that determines how the robots move, how fast they move and toward which target they move."

Using the technique, the team built and demonstrated three "meta-bots" with different capabilities. One robot can navigate around S-shaped corners and randomly placed obstacles, another can escape in response to a contact impact, while the third robot could walk over rough terrain and even make small jumps.

Other UCLA authors of the study are graduate students Desheng Yao, Ryan Hensleigh, Zhenpeng Xu and Haotian Lu; postdoctoral scholar Ariel Calderon; development engineering associate Zhen Wang. Additional authors are Sheyda Davaria, a research associate at Virginia Tech; Patrick Mercier, an associate professor of electrical and computer engineering at UC San Diego; and Pablo Tarazaga, a professor of mechanical engineering at Texas A&M University.

The research was supported by a Young Faculty Award and a Director's Fellowship Award from the U.S. Defense Advanced Research Projects Agency (DARPA), with additional funding from the U.S. Office of Naval Research, the Air Force Office of Scientific Research and the National Science Foundation.

The advance incorporates 3D printing techniques previously developed by Zheng and Hensleigh while both were researchers at Virginia Tech, which holds the patent. The researchers plan to file an additional patent through the UCLA Technology Development Group for the new methodology developed at UCLA.


Related Multimedia:3D-printed "meta-bot"

Journal Reference:Huachen Cui, Desheng Yao, Ryan Hensleigh, Haotian Lu, Ariel Calderon, Zhenpeng Xu, Sheyda Davaria, Zhen Wang, Patrick Mercier, Pablo Tarazaga, Xiaoyu (Rayne) Zheng. Design and printing of proprioceptive three-dimensional architected robotic metamaterials. Science, 2022; 376 (6599): 1287 DOI: 10.1126/science.abn0090