Not just lizards—alligators can regrow their tails too

by Arizona State University

American alligator (Alligator mississippiensis) 

Credit: Ruth Elsey and the Louisiana Department of Wildlife and Fisheries.

American alligators are about as close to dinosaurs as you can get in modern times, and can grow up to 14 feet in length. While much smaller reptiles such as lizards are able to regenerate their tails, the question of whether the much larger alligator is able to regrow their massive tails has not been well studied. A team of researchers from Arizona State University and the Louisiana Department of Wildlife and Fisheries have uncovered that young alligators have the ability to regrow their tails up to three-quarters of a foot, or 18% of their total body length.=
An interdisciplinary team of scientists used advanced imaging techniques combined with demonstrated methods of studying anatomy and tissue organization to examine the structure of these regrown tails. They found that these new tails were complex structures with a central skeleton composed of cartilage surrounded by connective tissue that was interlaced with blood vessels and nerves. They speculate that regrowing their tails gives the alligators a functional advantage in their murky aquatic habitats.

The findings are published in the journal Scientific Reports.

"What makes the alligator interesting, apart from its size, is that the regrown tail exhibits signs of both regeneration and wound healing within the same structure," said Cindy Xu, a recent Ph.D. graduate from ASU's molecular and cellular biology program and lead author of the paper. " Regrowth of cartilage, blood vessels, nerves, and scales were consistent with previous studies of lizard tail regeneration from our lab and others. However, we were surprised to discover scar-like connective tissue in place of skeletal muscle in the regrown alligator tail. Future comparative studies will be important to understand why regenerative capacity is variable among different reptile and animal groups."


https://phys.org/news/2020-11-lizardsalligators-regrow-tails.html

Play3-D reconstruction video of the cartilage tube found in the regrown alligator tail. This structure extends the length of the regrown tail and features randomly distributed pores. Credit: Arizona State University

"The spectrum of regenerative ability across species is fascinating, clearly there is a high cost to producing new muscle," said Jeanne Wilson-Rawls, co-senior author and associate professor with ASU's School of Life Sciences. "

"Staff biologists in our Alligator Research and Management Program have been pleased to partner with Dr. Kusumi at Arizona State University for many years," said Ruth M. Elsey, a Biologist Manager with the Louisiana Department of Wildlife and Fisheries. "We see alligators in the field with some indication of possible regrowth of tail tissue, but their expertise led to the current study detailing the histological changes associated with the capacity for possible partial tail regrowth or wound re

Alligators, lizards, and humans all belong to a group of animals with backbones called amniotes. While the interdisciplinary team has previous studied the ability of lizards to regenerate their tails, this finding of regrowth of complex new tails in the alligator gives further information about the process in amniotes.

The regrown alligator tail is different from the original tail. Regrown scales are densely arranged and lack dorsal scutes (top right). An unsegmented tube of cartilage (yellow) replaces bone (tan) in the regrown tail. Moreover, the regrown tail lacks skeletal muscle (red) and instead, there is an abundance of fibrous connective tissue (pink). Credit: Arizona State University

"The ancestors of alligators and dinosaurs and birds split off around 250 million years ago," said co-senior author Kenro Kusumi, professor and director of ASU's School of Life Sciences and associate dean in the College of Liberal Arts and Sciences. "Our finding that alligators have retained the cellular machinery to regrow complex tails while birds have lost that ability raises the question of when during evolution this ability was lost. Are there fossils out there of dinosaurs, whose lineage led to modern birds, with regrown tails? We haven't found any evidence of that so far in the published literature."

"If we understand how different animals are able to repair and regenerate tissues, this knowledge can then be leveraged to develop medical therapies," said Rebecca Fisher, co-author and professor with the University of Arizona College of Medicine-Phoenix and ASU's School of Life Sciences. The researchers hope their findings will help lead to discoveries of new therapeutic approaches to repairing injuries and treating diseases such as arthritis.


Explore further

How lizards regenerate their tails: Researchers discover genetic 'recipe'
More information: Cindy Xu et al, Anatomical and histological analyses reveal that tail repair is coupled with regrowth in wild-caught, juvenile American alligators (Alligator mississippiensis), Scientific Reports (2020). 

DOI: 10.1038/s41598-020-77052-8
Journal information: Scientific Reports


Provided by Arizona State University

Secrets of the 'lost crops' revealed where bison roam

by Talia Ogliore, Washington University in St. Louis

American bison at the Joseph H. Williams Tallgrass Prairie Preserve in Oklahoma. 

Credit: Natalie Mueller

Blame it on the bison.

If not for the wooly, boulder-sized beasts that once roamed North America in vast herds, ancient people might have looked past the little barley that grew under those thundering hooves. But the people soon came to rely on little barley and other small-seeded native plants as staple food.

New research from Washington University in St. Louis helps flesh out the origin story for the so-called "lost crops." These plants may have fed as many Indigenous people as maize, but until the 1930s had been lost to history.

As early as 6,000 years ago, people in the American Northeast and Midwest were using fire to maintain the prairies where bison thrived. When Europeans slaughtered the bison to near-extinction, the plants that relied on these animals to disperse their seeds began to diminish as well.

"Prairies have been ignored as possible sites for plant domestication, largely because the disturbed, biodiverse tallgrass prairies created by bison have only been recreated in the past three decades after a century of extinction," said Natalie Mueller, assistant professor of archaeology in Arts & Sciences.

Following the bison

In a new publication in The Anthropocene Review, Mueller reports on four field visits during 2019 to the Joseph H. Williams Tallgrass Prairie Preserve in eastern Oklahoma, the largest protected remnant of tallgrass prairie left on Earth. The roughly 40,000-acre preserve is home to about 2,500 bison today.

Mueller waded into the bison wallows after years of attempting to grow the lost crops from wild-collected seed in her own experimental gardens.

"One of the great unsolved mysteries about the origins of agriculture is why people chose to spend so much time and energy cultivating plants with tiny, unappetizing seeds in a world full of juicy fruits, savory nuts and plump roots," Mueller said.

They may have gotten their ideas from following bison.


Anthropologists have struggled to understand why ancient foragers chose to harvest plants that seemingly offer such a low return on labor.

"Before any mutualistic relationship could begin, people had to encounter stands of seed-bearing annual plants dense and homogeneous enough to spark the idea of harvesting seed for food," Mueller said.

Recent reintroductions of bison to tallgrass prairies offer some clues.

For the first time, scientists like Mueller are able to study the effects of grazing on prairie ecosystems. Turns out that munching bison create the kind of disturbance that opens up ideal habitats for annual forbs and grasses—including the crop progenitors that Mueller studies.
Credit: Washington University in St. Louis

Harvesting at the wallow's edge

At the Tallgrass Prairie Preserve, Mueller and her team members got some tips from local expert Mike Palmer.

"Mike let us know roughly where on the prairie to look for the bison," Mueller said. "His occurrence data were at the resolution of roughly a square mile, but that helps when you're on a 60-square-mile grassland.

"I thought it would be hard to find trails to follow before I went out there, but it's not," she said. "They are super easy to find and easy to follow, so much so that I can't imagine humans moving through a prairie any other way!"

Telltale signs of grazing and trampling marked the "traces" that bison make through shoulder-high grasses. By following recently trodden paths through the prairie, the scientists were able to harvest seeds from continuous stands of little barley and maygrass during their June visit, and sumpweed in October.

"While much more limited in distribution, we also observed a species of Polygonum closely related to the crop progenitor and wild sunflowers in bison wallows and did not encounter either of these species in the ungrazed areas," Mueller said.

It was easier to move through the prairie on the bison paths than to venture off them.

"The ungrazed prairie felt treacherous because of the risk of stepping into burrows or onto snakes," she said.

With few landscape features for miles in any direction, the parts of the prairie that were not touched by bison could seem disorienting.

"These observations support a scenario in which ancient people would have moved through the prairie along traces, where they existed," Mueller said. "If they did so, they certainly would have encountered dense stands of the same plant species they eventually domesticated."

Diverse landscapes

Mueller encourages others to consider the role of bison as 'co-creators'—along with Indigenous peoples—of landscapes of disturbance that gave rise to greater diversity and more agricultural opportunities.

"Indigenous people in the Midcontinent created resilient and biodiverse landscapes rich in foods for people," she said. "They managed floodplain ecosystems rather than using levees and dams to convert them to monocultures. They used fire and multispecies interactions to create mosaic prairie-savanna-woodland landscapes that provided a variety of resources on a local scale."

Mueller is now growing seeds that she harvested from plants at the Tallgrass Prairie Preserve and also seeds that she separated from bison dung from the preserve. In future years, Mueller plans to return to the preserve and also to visit other prairies in order to quantify the distribution and abundance of crop progenitors under different management regimes.

"These huge prairies would not have existed if the native Americans were not maintaining them," using fire and other means, Mueller said. But to what end? Archaeologists have not found caches of bones or other evidence to indicate that Indigenous people were eating lots of prairie animals. Perhaps the ecosystems created by bison and anthropogenic fire benefited the lost crops.

"We don't think of the plants they were eating as prairie plants," she said. "However, this research suggests that they actually are prairie plants—but they only occur on prairies if there are bison.

"I think we're just beginning to understand what the botanical record was telling us," Mueller said. "People were getting a lot more food from the prairie than we thought."


Explore further
Five facts about bison, the new US national mammal

More information: Natalie G Mueller et al. Bison, anthropogenic fire, and the origins of agriculture in eastern North America, The Anthropocene Review (2020).

DOI: 10.1177/2053019620961119

Provided by Washington University in St. Louis

ARACHNOPHOBIA TRIGGER
Tarantula toxin attacks with molecular stinger

by University of Washington

New studies of the molecular action of tarantula venom on sodium channels may suggest ideas for the structural design of better drugs to treat chronic pain. The venom plunges a biochemical "stinger" into a voltage sensor on the channel that traps it in its resting position, keeping the channel from activating and from producing electrical signals.

 Credit: Alice C. Gray

Oversized, hairy tarantulas may be unsightly and venomous, but surprisingly their hunter toxin may hold answers to better control of chronic pain.

A bird-catching Chinese tarantula bite contains a stinger-like poison that plunges into a molecular target in the electrical signaling system of their prey's nerve cells.

A new high-resolution cryo-electron microscopy study shows how the stinger quickly locks the voltage sensors on sodium channels, the tiny pores on cell membranes that create electrical currents and generate signals to operate nerves and muscles. Trapped in their resting position, the voltage sensors are unable to activate.

The findings are published Nov. 23 in Molecular Cell, a journal of Cell Press.

"The action of the toxin has to be immediate because the tarantula has to immobilize its prey before it takes off," said William Catterall, professor of pharmacology at the University of Washington School of Medicine. He was the senior researcher, along with pharmacology professor and Howard Hughes Medical Institute investigator, Ning Zheng, on the study of the molecular damage inflicted by tarantula venom.

While some might dismiss those tarantulas as ugly, tough and mean, medical scientists are actually interested in their venom's ability to trap the resting state of the voltage sensor on voltage-gated sodium channels and shut them down. Such studies of toxins from these "big, nasty dudes," as Catterall describes them, could point to new approaches to structurally designing drugs that might treat chronic pain by blocking sensory nerve signals.

This graphic abstract for a Nov. 23 Molecular Cell paper shows how a tarantula nerve toxin acts on a chimera of a voltage-gated sodium channel. The chimeric sodium channel contains part of a human channel crucial for pain transmission that has been imported onto a model ancestral sodium channel from a bacterium. The tarantula toxin has a lysine stinger that traps the voltage sensor on the sodium channel and keeps it from activating. The toxin thus immobilizes the tarantula's prey. Its action on sodium channels also holds ideas for designs for better pain-control drugs. Credit: Catterall and Zheng labs/UW Medicine

Catterall explained that chronic pain is a difficult-to-treat disorder. Efforts to seek relief can sometimes be a gateway to opiate overdose, addiction, prolonged withdrawal, and even death. The development of safer, more effective, non-addictive drugs for pain management is a vital need.

However, because it has been hard to capture the functional form of the tarantula toxin-ion channel chemical complex, reconstructing the toxin's blocking method in a small molecule has so far eluded molecular biologists and pharmacologists seeking new ideas for better pain drug designs.

Researchers overcame this obstacle by engineering a chimeric model sodium channel. Like mythical centaurs, chimeras are composed of parts of two or more species. The researchers took the toxin-binding region from a specific type of human sodium channel that is crucial for pain transmission and imported it into their model ancestral sodium channel from a bacterium. They were then able to obtain a clear molecular view of configuration of the potent toxin from tarantula venom as it binds tightly to its receptor site on the sodium channel.

This achievement revealed the structural basis for voltage sensor trapping of the resting state of the sodium channel by this toxin.

"Remarkably, the toxin plunges a 'stinger' lysine residue into a cluster of negative charges in the voltage sensor to lock it in place and prevent its function," Catterall said. "Related toxins from a wide range of spiders and other arthropod species use this molecular mechanism to immobilize and kill their prey."

Catterall explained the medical research importance of this discovery. The human sodium channel placed into the chimeric model is called the Nav1.7 channel. It plays an essential role, he noted, in transmission of pain information from the peripheral nervous system to the spinal cord and brain and is therefore a prime target for pain therapeutics.

"Our structure of this potent tarantula toxin trapping the voltage sensor of Nav1.7 in the resting state," Catterall noted, "provides a molecular template for future structure-based drug design of next-generation pain therapeutics that would block function of Nav1.7 sodium channels."


Explore further  Giant spider provides promise of pain relief for irritable bowel syndrome

More information: Goragot Wisedchaisri et al, Structural Basis for High-Affinity Trapping of the NaV1.7 Channel in Its Resting State by Tarantula Toxin, Molecular Cell (2020).

DOI: 10.1016/j.molcel.2020.10.039

Journal information: Molecular Cell

Provided by University of Washington

Platypus should be listed as a threatened species, new report says

by University of New South Wales

In NSW, the number of platypus observations declined by around 32 per cent in the last 30 years. Credit: Stuart Cohen

A landmark assessment by scientists at UNSW Sydney recommends the platypus be listed as a threatened species under Australia's and NSW environmental legislation.

The UNSW researchers, along with the Australian Conservation Foundation, WWF-Australia and Humane Society International Australia, today submitted their recommendations to the Commonwealth and NSW Government's scientific committees.

The International Union for Conservation of Nature (IUCN) Red List currently lists the iconic species as 'Near Threatened' – but it is not listed as threatened under Australia's Environment Protection and Biodiversity Conservation (EPBC) Act.

For their assessment, a team of researchers from the Centre for Ecosystem Science (CES) at UNSW collated all available data and evidence and assessed the species' risk of extinction against IUCN and EPBC criteria.

The scientists find that the area of eastern Australia where platypuses are found has shrunk by up to 22 percent, or about 200,000 km2, over the past 30 years.

"We recorded the most severe declines in platypus observations in NSW—particularly in the Murray-Darling Basin, where natural river systems and water flows have been the most heavily modified," says UNSW's Dr. Tahneal Hawke, a lead author of the report.

In NSW, the number of platypus observations declined by around 32 percent in the last 30 years, compared to 27 percent in Queensland. In Victoria, even though the state-wide decline was around 7 percent, the researchers observed reductions in numbers of as much as 54-65 percent in some urban catchments near Melbourne.

The scientists' models predict that platypus populations may have declined by more than 50 percent as a result of historic land clearing, river regulation, and extreme droughts—some of the major threats affecting the species. Platypuses also drown in closed freshwater yabby traps, which are still legally sold in NSW and Queensland.

"The platypus continues to face ongoing threats across its range. Unsustainable water extraction and land clearing will continue to put pressure on freshwater ecosystems and drive future declines in the future," says UNSW's Dr. Gilad Bino, a lead author.

The changing climate also presents a serious threat to platypuses, with more severe droughts, reduced rainfall and intense fires drying out rivers, reducing water quality, and destroying the riparian vegetation.

Listing the platypus as threatened would increase the scrutiny placed on developments that might endanger the species and prioritize its monitoring.

"It would also mean an increased focus on what we can do to improve the situation," Professor Kingsford, CES director, says.

The scientists say protecting one of the world's most iconic animals and the rivers it relies on must be a national priority.

"We have a national and international responsibility to look after this unique animal and the signs are not good. Platypus are declining and we need to do something about threats to the species before it is too late," Prof. Kingsford says.


Explore further Researchers warn of uncertain future for the platypus

More information: d3n8a8pro7vhmx.cloudfront.net/ … Final.pdf?1605754019

Provided by University of New South Wales

Australia: Scientists push to list platypus as threatened

Numbers of the vulnerable duck-billed species, unique to Australia, have dropped by more than a fifth since 1990. Extreme droughts linked to climate change threaten the platypus' existence, scientists have warned.






Scientists have called for the Australian native platypus to be listed as a "threatened species" after a report found the habitat of the semi-aquatic duck-billed mammal had shrunk by up to 22% over the past 30 years.

Researchers from the University of New South Wales (UNSW) said severe drought brought by climate change, land clearing for farming and dam building are to blame. 

"The platypus continues to face ongoing threats across its range. Unsustainable water extraction and land clearing will continue to put pressure on freshwater ecosystems and drive future declines in the future," lead author Gilad Bino said Monday, adding that increased severity and occurrence of bush fires is also likely to have contributed to the platypus's decline.

Droughts pose serious threat

The beaver-tailed, webbed-feet platypus live mostly across Australia's eastern coast, close to rivers and streams. They cannot live outside water. As Australia dries further, their habitat could get even smaller, the scientists warned.

Richard Kingsford, director of UNSW's Centre for Ecosystem Science, said that platypus populations "will disappear from some of our rivers without returning, if rivers keep degrading with droughts and dams."

Read more:'Wildfires are climate fires': How to talk about climate emergency, global heating

Currently, the platypus is listed as "near threatened" by the International Union for Conservation of Nature, but it is not listed as threatened under Australia's Environment Protection and Biodiversity Conservation Act.

Changing its listing would prioritize its monitoring and "also mean an increased focus on what we can do to improve the situation," Kingsford said.

VIDEO 

Dry weather threatens another iconic Australian species

https://www.dw.com/en/australia-scientists-push-to-list-platypus-as-threatened/a-55696625

In the Cerrado, topography explains the genetic diversity of amphibians more than land cover

by André Julião, FAPESP

Study shows that a tree frog endemic to a mountainous region of the Brazilian savanna is unable to disperse and find genetically closer mates when the terrain is rugged, potentially endangering survival of the species Credit: Renato C. Nali

The savanna tree frog Bokermannohyla ibitiguara is about 4 cm long and is found only in gallery forest along streams in the Serra da Canastra mountain range in the state of Minas Gerais, Southeast Brazil. In this watery forest environment, it can grow, feed, mate, and lay eggs without needing to range very far throughout its life cycle, according to a study published in Diversity and Distributions.


According to the Brazilian and US researchers who conducted the study, topography rather than vegetation is the main factor leading to more or less dispersal of the species in the territory, and this information is even recorded in its DNA.

They analyzed genetic variation among groups of B. ibitiguara living inside and outside the Serra da Canastra National Park, a protected area in the region, discovering that the flatter the terrain, the more genetically diverse is the population.

In areas of highly variable elevation, individuals are genetically similar. In evolutionary terms, this can be harmful to the species, which becomes more susceptible to disease and climate change, for example.

"Genetic analysis and conservation studies typically take land cover into account, among other factors, but the Cerrado [Brazilian savanna] is topographically diverse, including montane regions with high plateaus [chapadões] separated by low areas. We set out to verify whether this variable terrain played a part in the genetic diversity of the species, and found that it did. The vegetation alone didn't explain the genetic differences we identified between sites, or even within the same site. The topography did," said Renato Christensen Nali, first author of the article and a professor at the Federal University of Juiz de Fora's Institute of Biological Sciences (ICB-UFJF) in Minas Gerais, Brazil.

The study was one of the results of Nali's doctoral research, conducted at São Paulo State University's Bioscience Institute (IB-UNESP) in Rio Claro, Brazil, with a scholarship from FAPESP (São Paulo Research Foundation).

The research was part of the project "Reproductive ecology of anuran amphibians: an evolutionary perspective", for which the principal investigator is Cynthia Peralta de Almeida Prado, a co-author of the article. She is a professor at UNESP's School of Agrarian and Veterinary Sciences in Jaboticabal and teaches graduate students in zoology at IB-UNESP in Rio Claro.

The flatter the better

"The findings are very interesting because they bring to light a novel factor for conservation of the Cerrado, among other reasons. Ecological corridors and native forests are rightly considered important for conservation units, but more attention needs to be paid to the type of terrain. The topography should permit dispersal of the animals," said Nali, who heads ICB-UFJF's Amphibian Evolutionary Ecology Laboratory (Lecean).


To arrive at the results, the researchers analyzed 12 populations of B. ibitiguara, six inside Serra da Canastra National Park and six outside. Genetic diversity was much higher among the anurans living in the protected area than among those living outside the park. When the researchers correlated information on the degree of protection of the areas with the state of the vegetation, they found that these factors were less decisive for genetic diversity than the topography.

"The terrain is much more rugged outside the park, whereas inside it there's a large, very even plateau where the anurans can disperse more, find mates in more distant areas, and increase their genetic diversity," Nali said. "Outside the park, the rugged terrain and variable elevation appear to confine them to small areas."

The influence of these factors was evidenced by genetic tests. The researchers used a technique known as macrosatellite marker analysis to examine specific regions of the genome and found higher allele diversity in the populations living in the park. Allele diversity is one of the determinants of genetic integrity and adaptive potential.

In addition, the populations living outside the park displayed a greater loss of heterozygosity. If this loss, which is associated with declining genetic variability, recurs across several generations, it can eventually threaten the population's survival.

The study underscores the importance of topography as a factor to consider in conservation studies, as well as showing how the mere presence of a species in an area cannot ensure that it is not endangered.

"Molecular analysis enables us to find out if a population's genetic status is favorable," Nali said. "An area may have a large number of individuals, but DNA analysis may show that its genetic constitution is unfavorable, with few alleles and low heterozygosity. In practice, therefore, the population's effective size is small."

Although the study focused on only one species, he added, the findings can apply to others as well since the physical characteristics associated with dispersal are similar for other frogs and toads. More species need to be investigated to confirm the applicability of the findings.

The group noted that land cover nevertheless remains an important factor for conservation in the Cerrado, more than 50% of which has been converted into pasture or cropland, while less than 5% is protected by conservation units.


Explore further Elephant genetics guide conservation

More information: Renato C. Nali et al, Topography, more than land cover, explains genetic diversity in a Neotropical savanna tree frog, Diversity and Distributions (2020). DOI: 10.1111/ddi.13154

Journal information: Diversity and Distributions

Provided by FAPESP

The secret origins of China's 40-year plan to end carbon emissions

by Bloomberg News

Credit: CC0 Public Domain

The biggest emitter of planet-warming pollution managed to take almost the whole world by surprise. In a September speech to the United Nations, Chinese President Xi Jinping put a 2060 end date on his country's contribution to global warming. No other nation can do more to keep warming below the 1.5C threshold set in the Paris Agreement. Yet diplomats, climate activists and even policy experts inside China for the most part had not anticipated this pivotal turnabout.

Just days before Xi's U.N. appearance, in fact, European leaders including European Commission President Ursula von der Leyen and German Chancellor Angela Merkel had pressed him directly on a videoconference to follow the EU's example in setting a climate-neutrality goal. Notes from the call reviewed by Bloomberg Green indicate that Xi gave no hint he was about to abandon China's long-established policy against climate restrictions on economic growth.

Inside China, meanwhile, experts who specialize in the intricacies of emissions policy were stunned by Xi's speech. "Can this goal be achieved?" asked a bewildered post on WeChat from a retired climate negotiator in Beijing. Most stakeholders with a hand in previous climate decisions had been kept out of the loop, according to interviews with more than a dozen industry groups, environmentalists and government researchers in China. But the decision to completely reorient a gigantic economy that's dominated by coal, at the cost of trillions of dollars, didn't come from nowhere.

The secret drive for China's 2060 target took shape inside Tsinghua University, where climate scientists had quietly spent more than a year modeling different pathways to reach net zero. Xie Zhenhua, a former environmental bureaucrat and veteran diplomat, oversaw the work from his threadbare office as head of the college's Institute of Climate Change and Sustainable Development. Few within China's strict hierarchy can match Xie's mastery of government bureaucracy and climate science, making him an influential voice on the issue among the ruling elite.

Xie is modest about his role. "We made policy proposals to relevant leaders and departments," he says in an interview on Tsinghua's campus in late October, dressed like a typical Communist Party cadre in a dark suit and pressed white shirt. "It seems our proposals had some impact."

China and other developing nations had long held that wealthier countries that benefited from earlier industrialization, heedless of the dangers from burning fossil fuel, should carry most of the economic burden for preventing catastrophic warming. Xie spent more than a decade as China's top climate diplomat, in the early years fiercely defending the principle that emerging economies have a right to uncontrolled carbon emissions. On a population-adjusted basis, after all, far too much carbon dioxide began its journey into the atmosphere from smokestacks and tailpipes in the U.S. and Europe.


At the 2011 international climate talks in Durban, South Africa, Xie gave a table-pounding speech calling out the hypocrisy of developed nations; news footage made him famous throughout China. Now at the twilight of his career, he has done more than anyone else outside Xi's ruling circle to position China as a global climate leader, establishing a carbon neutrality plan ahead of the U.S.

"When you first start, it's just a job," Xie says. "But after some time, when you see the impact you could bring to the country, the people, and the world, it is no longer just a job. It has become a cause, a higher calling."

At 71, Xie should be happily retired after more than three decades shaping China's approach to the climate and environmental protection. Communist Party custom requires members of Xie's rank who turn 70 to relinquish official roles. A rare exception allowed him to receive an appointment as special adviser to the environment ministry this year.

In that capacity, Xie submitted the 2060 recommendations based on research his institute had done in coordination with a dozen government-linked think tanks. The proposal likely arrived on Xi's desk via Vice Premier Han Zheng, who sits on the Politburo's Standing Committee and oversees the environment ministry.

Every major decision in China is made collectively by the seven men on the Standing Committee. Ultimate credit invariably goes to Xi, the nation's most powerful leader since Mao Zedong. Environmental protection has become one of Xi's core issues as he has sought to temper the growth-at-all-costs mentality that dominated China's breakneck industrialization.

Before the U.N. speech, though, Xi had never spoken publicly about carbon neutrality. The proposition was considered so remote that it was hardly mentioned by state media. "China was reluctant to talk about concepts like net-zero emissions or carbon neutrality," says Li Shuo, a prominent environmentalist in China who has spent years lobbying Xie for more aggressive policies. "Xie has played a part in bridging that gap."

To translate global climate imperatives into Chinese government policy, you need to be fluent in two extremely esoteric languages: sloganeering Communist Party-speak on the one hand, and the technocratic vocabulary of international climate negotiation on the other. That's how Xie manages the trick of advocating for the greater commitments other countries want from China without making them seem like concessions.

Examples of this unusual ability pop out of Xie's interview: The 2060 goal, he says, will help China become a "great modern socialist power" and build "a community with a shared future for mankind," mottos Xi has used to guide long-term policymaking. Then, code-switching effortlessly, he explains that China's stance on "mitigation, adaptation, financing and technology" will still need to be discussed at next year's COP26 U.N. Climate Change Conference, at which nations work out the details of the Paris Agreement.

Xie's career has traced China's meteoric economic rise—and its reckoning with the damage left behind. His tenure as the head of China's environment protection administration ended abruptly in 2005 after deadly explosions at a chemical plant in Jilin, a province near the border with North Korea and Russia. The accident affected tens of millions of people.

Such an incident would have derailed the career of a typical civil servant, but Xie bounced back and eventually ended up on the Communist Party Central Committee. He took over the role as China's primary international climate negotiator in 2007, and his approach didn't always resort to denouncing developed nations. A former colleague jokingly described him as "like a panda bear, very huggable."

"When you come to the negotiation table, you need to be honest and candid. People respect you for protecting your own country's interests," Xie says, looking back. "But you're also here to solve problems, to tackle climate change."

He clashed publicly with Todd Stern, the U.S. special climate envoy from 2009 to 2016, before hammering out a bilateral agreement in 2014 that brought China into the Paris Agreement two years later. Leaked emails from the period show the two negotiators reminiscing like old friends, discussing future visits and grandchildren. "He's somebody that I could always trust and somebody who I can do business with," Stern said in a telephone interview from Washington.

"This is a very meaningful task," Xie says. "A climate negotiator has only rivalries and friends, but he has no enemies."

Days after Xi addressed the U.N., the Tsinghua scientists were ready to present their roadmap to 2060. The plan called for a gradual energy transition over the next decade and a half, followed by a rapid acceleration requiring an almost sevenfold increase in solar energy and a near quintupling of nuclear power. Some analysts worried about this two-speed approach. The incremental start defers the hardest decisions until 2035, for the next generation.

This gradual trajectory to net zero probably helped Xie's plan face less pushback from top officials, according to two green activists who have worked with him. (They asked not to be identified, as activists in China are often targeted by the government for criticizing official policy.) The activists said a more ambitious short-term move, such as accelerating China's 2030 target for reaching peak emissions, would have likely provoked a backlash.

China has also given itself a 10-year buffer, as most other major economies are working toward net-zero emissions by 2050. This group includes the EU as well as Japan and South Korea, which swiftly followed Xi's U.N. announcement with pledges of their own. The U.S. could be next, with President-elect Joe Biden calling for a 2050 target.

There's risk that the extra decade for China will increase the temptation by policymakers to postpone painful changes. The grand vision for 2060 will have to be filtered through hundreds of official documents, beginning with the government's next five-year plan to be released in March. Different ministries, local governments and state-owned enterprises will then work the policies into their own blueprints, where things could get watered down or delayed.

Xie believes the 2060 target will force short-term changes. "The goal will be difficult or even impossible to reach if we rely on traditional technologies and maintain traditional ways of production, of living and consumption," he says. "This sends out a clear signal: We have to transform fast and innovate big."

It's not climate skepticism that drives the resistance. Chinese schoolchildren are taught the science of global warming from a young age, and citizens are eager for the government to clean up the polluted air and water. The main issue is the coal industry. China mines and burns half the world's supply, and the sector still supports tens of millions of jobs.

After Xi endorsed the Paris Agreement, the Chinese coal industry launched a nationwide campaign to retrofit power plants with what it claims to be low-emission technology. This effort was publicly endorsed by influential academics, and that support in turn gave the coal industry cover to build new plants. On the very same day Xi addressed the U.N., a commentary in the People's Daily, a Communist Party mouthpiece, argued for the future of coal: "As long as coal is utilized in a clean and efficient way, it should be called clean energy."

Xie thinks this time will be different. "The ultra low-emission (coal) technology might have resolved the problems of air pollution and energy efficiency, but it can't solve the problem of CO2 emissions," he says. "Now that President Xi has made public the goal, I believe people will start to see the investment risks there."

With the next round of global climate talks coming up in Glasgow, Scotland, and countries under pressure to boost their commitments, China stands to gain a lot of goodwill by coming out of the gate early with a bold declaration. Turning the pledge into a domestic priority will be a challenge as the government faces pressure to keep its post-pandemic economic recovery going.

But it won't come down to choosing between climate action and growth. China suffered record floods in 2020 that affected more than 70 million people and caused some 214 billion yuan ($33 billion) in economic losses. "The damage done by climate change is not in the future," Xie says, "but right here, right now."


Explore further  China's new coal plants risk 2060 climate target: researchers

©2020 Bloomberg News
Distributed by Tribune Content Agency, LLC

Nature's toolkit for killing viruses and bacteria

by American Physical Society

Credit: Unsplash/CC0 Public Domain

They burst out of toilet bubbles, swim across drinking water, spread through coughs. Tiny infectious microbes—from the virus that causes COVID-19 to waterborne bacteria—kill millions of people around the world each year. Now engineers are studying how zinc oxide surfaces and natural hydrodynamic churning have the power to kill pathogens first.

"Bacterial contamination of common surfaces and of drinking water have been traditionally the main infection routes for transmission of serious diseases, often leading to mortality," said Abinash Tripathy, a researcher in mechanical and process engineering at ETH Zurich. "Our goal was to design a surface that can address both issues."

His group submerged clean zinc in hot water for 24 hours, which formed a zinc oxide surface covered in sharp nanoneedles. Then they introduced E. coli bacteria.

The surface kills almost all bacteria cultured on top of it very efficiently. And the biggest surprise? When sitting in contaminated water, the surface kills all waterborne E. coli within three hours—even bacteria it didn't touch.

This water disinfection at a distance works because the process generates a reactive oxygen species, which damages the cell walls of bacteria. The group from ETH Zurich, IIT Ropar India, and Empa, Switzerland, presented their initial findings at the 73rd Annual Meeting of the American Physical Society's Division of Fluid Dynamics.

In Southeast Asian and African countries where clean drinking water is scarce, current solar water disinfection methods take up to 48 hours and require a minimum intensity of sunlight. The new zinc oxide surface speeds up the disinfection process and does not need light.

"This surface can be used to disinfect water in remote areas at a very low cost," said Tripathy. "The fabrication technique is environmentally friendly, simple, and economical."

Surface and waterborne pathogens aren't the only killers. As the COVID-19 pandemic has reinforced, airborne viruses and bacteria pose a serious global challenge for disinfection.

The very droplets that carry pathogens through the air can play a role in destroying them. In the microseconds that droplets take to form, their fluids rearrange rapidly—stressing the microbes within.

"Think of a bucket with a fish in it. One imagines that if you start churning the fluid in the bucket too quickly, the fish won't be very happy," said Oliver McRae, a mechanical engineer. "It's a similar kind of thing—albeit on a much, much smaller scale—when you have, say, a pathogen in a droplet. Eventually the fluid's going to agitate too much for that bacteria or virus to survive."

McRae and a team from Boston University and the Centers for Disease Control and Prevention were studying how hydrodynamic agitation works when environmental bubbles produce droplets. After the onset of the pandemic, they started modeling droplets similar to those produced by the lungs and respiratory tract.

Using computational fluid dynamics, the team predicted how agitation works during aerosol formation. They discovered that stressors are very sensitive to droplet size. If the droplet shrinks or grows by one order of magnitude, the stressors change by two-and-a-half orders of magnitude.

The research could help explain why pathogens survive in some droplets and not others.

"Our focus has been on quantifying what the stressors are in these droplets," said McRae. "Hopefully this will be used in the future as part of a larger model to predict aerosol-based disease transmission."


Explore further Engineers devise new method to remove harmful E. coli from water

More information: Environmental Friendly and Scalable Fabrication of Antibacterial ZnO-Nanostructured Surfaces, meetings.aps.org/Meeting/DFD20/Session/Z01.12

Agitation May Naturally Disinfect the Smallest Pathogen-Laden Aerosols, meetings.aps.org/Meeting/DFD20/Session/S03.21

Provided by American Physical Society

Research evaluates effectiveness of conservation efforts

by University of Stirling

Credit: University of Stirling

New research from the University of Stirling into the effectiveness of international conservation projects could help to save endangered species from extinction.

The research, led by Laura Thomas-Walters of the Faculty of Natural Sciences, has published in respected journal, People and Nature. It focussed on evaluating a conservation campaign in São Tomé and Principe, that aimed to persuade local people to stop eating sea turtle meat and eggs.

Animal conservation faces a number of challenges, including climate change and the wildlife trade, and both time and money pressures. Knowing what measures work best and are most appropriate is essential to delivering effective conservation activity, but previous efforts to evaluate projects have encountered difficulties and delivered varying results.

The Stirling research team sought to address those difficulties by exploring better ways to evaluate conservation projects that work to change human behavior. The team conducted interviews and completed surveys with local people to determine if the campaign, which used tactics including television advertisements and cooking competitions, had been successful in reducing their consumption of sea turtles.

Laura Thomas-Walters, research project lead, said: "In conservation we are faced with a whole host of pressing issues that human actions cause, but we are short on time and money. Evaluating our projects is really important if we want to learn from them and improve future interventions.

"Unusually, for this research we measured both behavioral outcomes like attitudes or consumption, and conservation impacts, like sea turtle poaching. We found a decrease in self-reported sea turtle egg consumption and a decrease in the poaching of adult sea turtles.

"However, a simultaneous increase in law enforcement targeted at poaching may also have impacted the figures. Our recommendations for future projects include combining different outcome measures to triangulate hard-to-measure behaviors, and using theory-based evaluation methods."

The campaign, 'Tataluga—Mém Di Omali', which means "Sea Turtle—Mother of the Sea" in the local Forrô dialect featured community events, such as cooking contests to promote alternative food products, and theater performances, as well as a football competition. It also utilized mass media, including billboards, and television and radio adverts.

The Stirling team interviewed local people about their habits and sea turtle consumption, both before and after the campaign took place. The number of people who indicated they ate sea turtle eggs decreased from 40 per cent to 11 per cent during the campaign but this may also have been due to increased anti-poaching law enforcement.


Explore further Tracking sea turtle egg traffickers with GPS-enabled decoy eggs

More information: Laura Thomas‐Walters et al, Challenges in the impact evaluation of behaviour change interventions: The case of sea turtle meat and eggs in São Tomé, People and Nature (2020). DOI: 10.1002/pan3.10162

Provided by University of Stirling

COVID-19 is just one factor impacting wellbeing of employees working from home, study finds

by University of Exeter

Credit: CC0 Public Domain

A new study on work-life balance has found that the COVID-19 crisis is a crucial factor—but not the only one—behind low levels of wellbeing among employees working from home.

A research team including Professor Ilke Inceoglu, professor of organisational behaviour and HR management at the University of Exeter Business School, analysed data from 835 university employees, who completed a baseline questionnaire on wellbeing and took a weekly survey.

The preliminary results, which are being prepared for peer review, found that around 38% of home-workers felt anxious most or all of the time while death levels went up during the early stages of the first COVID-19 lockdown, with 8% saying they felt depressed.

The handling of the pandemic by government and employers was found to make those working from home more anxious and less enthusiastic about their jobs, and job insecurity, as a result of the economic impact of lockdown, also had a negative impact on wellbeing.

But the loneliness of working in a home environment and increased demands to juggle work and domestic responsibilities also caused a decline in employee wellbeing, the study found.

Nearly one in five (17%) remote workers reported feeling lonely, while around a quarter (25.9%) said that the competing demands of work and domestic duties (including childcare) had taken their toll.

Other aspects of remote working that contributed to a lower standard of wellbeing included increased job insecurity, the unpredictability of future workloads, new ways of working and a lack of support from employers.

The research team claims that these factors not only impact on wellbeing but also hamper employees' ability to make decisions and concentrate—15% said they found it hard to make many decisions on their own and 21% could not decide how to go about doing their work.

Professor Inceoglu said: "Our research is important in that it adds to the story of COVID but it also enables us to assess the role of location and whether the COVID-19 pandemic factors over and above conventional job design factors, which is indeed not the case."

Professor Stephen Wood, from the University of Leicester Business School and Principle Investigator of the study, added: "The pandemic has contributed to short term fluctuations in the wellbeing of employees working at home, but the factors that affect all jobs, the extent of job discretion, potential loneliness of working alone, and job insecurity remain important and is likely to remain so after the pandemic."

The results of the study were presented at an ESRC Festival of Social Science webinar on Friday 13 November.


Explore further The future of work is flexible, says new study

Provided by University of Exeter 

Siberian primrose has not had time to adapt to climate change

by University of Helsinki

Siberian primrose. Credit: Marko Hyvärinen

Siberian primrose, a species protected under the Habitats Directive of the European Union, spread northward from southern areas to the current Bothnian Bay as well as, through another route, to northern Norway with the gradually receding ice after the Ice Age. Compared to today, the warming of the climate was very slow at the time.

"Siberian primrose is specialized in growing on seashore meadows with low vegetation, which in Finland are formed by the post-glacial isostatic rebound. The species benefits from the lack of strong competitors and grazing that keeps the vegetation low," says Marko Hyvärinen, director of the Botany Unit of the Finnish Museum of Natural History, University of Helsinki.

In 2013, researchers at the Universities of Helsinki and Oulu planted both the Norwegian and Finnish varieties (Primula nutans ssubp. finmarchicha var. finmarchica and var. jokelae) at five different botanic gardens—in their home environments in Svanvik, northern Norway, and in Oulu, northern Finland, as well as in Rauma and Helsinki further south in Finland and in Tartu, Estonia.

As expected by the researchers, both varieties fared poorer in the southern gardens compared to Oulu and Svanvik, indicating that a warmer climate may be fatal for the species if it is incapable of adapting or relocating.

"We were surprised, however, by our finding that the Finnish populations were more successful in northern Norway than in Oulu—even more successful than the Norwegian variety there, in its home environment," says Postdoctoral Researcher Maria Hällfors from the Research Centre for Ecological Changeat the Faculty of Biological and Environmental Sciences, University of Helsinki.
Five botanical gardens in which Siberian primroses from Norway and Finland were planted. Credit: University of Helsinki

"This indicates that global warming already affects this plant species. We can only speculate how many other species are suffering from changes to their environment, if they, too, are unable to keep up with climate change," Hällfors says.

The researchers suggest that the poor adaptability of Siberian primrose in relation to global warming may contribute to the demise of these populations.

"Siberian primrose has no natural dispersal route further north. One way to help species like this to survive current and future challenges would be to relocate them, by human hand, further north. In other words, species could be protected by what is known as assisted migration," Hällfors says.

Another option is to ensure that species have sufficiently large high-quality habitats to preserve populations at a viable level. This would ensure enough genetic variation within the populations, that is, different individuals that have a higher probability to posit characteristics that are suitable in the new conditions.

"In any case, investments in ex situ conservation, or the conservation of species outside their natural habitat, are needed. As an example, seeds of a species can be stored in a seed bank from where the species could be re-introduced to nature," Hällfors notes.


Explore further

Understanding differences within species is critical to conservation efforts

More information: Maria Hällfors et al. Translocation of an arctic seashore plant reveals signs of maladaptation to altered climatic conditions, PeerJ (2020). DOI: 10.7717/peerj.10357

Journal information: PeerJ

Provided by University of Helsinki