It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, August 24, 2021
Human, swine waste pose dual threats to water quality after flooding
A study that monitored surface waters in the wake of 2018’s Hurricane Florence finds that waters contaminated by fecal bacteria were affected by both human and swine waste.
“We found that surface waters in eastern North Carolina were more likely to face dual contamination than to be contaminated by either human waste or swine waste by themselves,” says Angela Harris, corresponding author of the study and an assistant professor of civil, construction and environmental engineering at North Carolina State University.
“This means people are dealing with multiple hazards,” Harris says. “It also means there are two sources of fecal contamination that need to be addressed. It’s not just the swine industry, and it’s not just wastewater treatment plants or septic systems.”
For the study, researchers collected surface water samples at 40 sites across eastern N.C. Samples were collected one week after Hurricane Florence made landfall in September 2018, and again one month after landfall. These samples are referred to as Phase 1 and Phase 2, respectively.
The researchers tested the water samples for a variety of bacteria. Specifically, the samples were tested for: E. coli – an indicator species used to identify fecal contamination and the likelihood that there are pathogens present; pathogens such as Arcobacter butzleri and various Listeria species; and bacterial species associated specifically with either swine or humans, so that researchers could trace contamination back to its source.
“About 30% of the surface water sites we tested had levels of bacteria that would have made those waters unsafe for swimming,” Harris said.
The most commonly found pathogen was Arcobacter, a finding the research team published late last year. The new study reports that the presence of Arcobacter wasn’t associated with human or swine fecal markers. In other words, it’s not clear where the pathogen is coming from.
Another mystery was that the levels of E. coli in Phase 2 samples taken from permanent water channels (as opposed to floodplains) were actually higher than the levels of E. coli in the Phase 1 samples.
“We’re not sure why E. coli levels jumped in those Phase 2 samples,” Harris says. “It could be because water levels were decreasing, so there was less dilution. It could be due to temporary changes in regulatory requirements in the wake of the hurricane. It could be some other variable we haven’t identified. We need a lot more monitoring data to begin to tease that apart.
“A lot of post-flooding work has been done in urban areas,” Harris says. “This is one of the few studies that looks at post-flooding water quality impacts in rural, agricultural areas. And our findings suggest that this merits a much closer look. This work highlights the need for more routine water quality monitoring in these areas that tests for the bacteria we were looking at here. That could help us establish broader baseline measures for water quality.
“This is particularly important given concerns around antibiotic-resistant pathogens and the likelihood that we’ll be seeing more extreme wet weather events in the future.”
The study, “Microbial Contamination in Environmental Waters of Rural and Agriculturally-Dominated Landscapes Following Hurricane Florence,” is published in the journal ACS ES&T Water. The paper was co-authored by Emine Fidan, a Ph.D. student at NC State; Natalie Nelson and Mahmoud Sharara, assistant professors of biological and agricultural engineering at NC State; Ryan Emanuel, a professor of environmental resources at NC State; Theo Jass and Jeffrey Niedermeyer, former research assistants at NC State; Sophia Kathariou, professor of food, bioprocessing and nutrition sciences at NC State; Francis de los Reyes III, professor of civil, construction and environmental engineering at NC State; and Diego A. Riveros-Iregui and Jill R. Stewart of the University of North Carolina at Chapel Hill.
The study was done with support from the National Science Foundation, under grants 1901588 and 1901202; the North Carolina Policy Collaboratory; and the International Life Sciences Institute.
The “megadrought” impacting the Colorado River system this year has been devastating to the 40 million people who rely on it for water. But could this drought have been predicted? Will we be able to predict the next one?
Mountain watersheds provide 60 to 90% of water resources worldwide, but there is still much that scientists don’t know about the physical processes and interactions that affect hydrology in these ecosystems. And thus, the best Earth system computer models struggle to predict the timing and availability of water resources emanating from mountains.
Now a team of U.S. Department of Energy scientists led by Lawrence Berkeley National Laboratory (Berkeley Lab) aims to plug that gap, with an ambitious campaign to collect a vast array of measurements that will allow scientists to better understand the future of water in the West. The Surface Atmosphere Integrated Field Laboratory (SAIL) campaign will start on September 1, when scientists flip the switch on a slew of machinery that has been amassed in the Upper Colorado River Basin.
Over the course of two falls, two winters, two springs, and a summer, more than three dozen scientific instruments – including a variety of radars, lidars, cameras, balloons, and other state-of-the-art equipment – will collect a treasure trove of data on precipitation, wind, clouds, aerosols, solar and thermal energy, temperature, humidity, ozone, and more. That data can then be used to turbocharge the capabilities of Earth system models and answer many scientific questions about how, why, where, and when rain and snow will fall. In close collaboration with researchers specializing in Earth’s surface and subsurface, the SAIL campaign will help the scientific community understand how mountains extract moisture from the atmosphere and then process the water all the way down to the bedrock beneath Earth’s surface. Ultimately, this will provide the tools for scientists to better predict the future availability of water.
“The Upper Colorado River powers more than $1 trillion in economic activity and provides an immense amount of hydroelectric power, but it’s very understudied compared to how important it is,” said Berkeley Lab scientist Daniel Feldman, the lead SAIL investigator. “We’re starting to see really dramatic consequences from the changing water resources, but the details of what is actually going on in these places where the water's coming from – those details matter, and that’s what SAIL is focused on.”
CAPTION
This rain gauge will measure the amount of liquid precipitation that falls during ARM’s Surface Atmosphere Integrated Field Laboratory (SAIL) field campaign in Gothic, Colorado. The measurements from the rain gauge will also help scientists validate precipitation estimates from radar. The SAIL campaign, which will run from September 2021 to June 2023, will help scientists better understand how water is produced and transported in mountainous watersheds.
CREDIT
John Bilberry, Los Alamos National Laboratory
From the Arctic to the Rockies
SAIL is a research campaign managed by DOE’s Atmospheric Radiation Measurement (ARM) user facility, a key contributor to climate research with its stationary and mobile climate observatories located throughout the United States and around the world. Much of the equipment being used in SAIL has just returned from a one-year Arctic expedition.
“SAIL is a timely campaign because of the ongoing drought in the Western United States,” said Sally McFarlane, DOE Program Manager for the ARM user facility. “The Colorado River is of particular concern because it supplies water to 40 million people. SAIL is bringing together data from ARM and other research programs from within DOE to ultimately help provide insights into the atmospheric processes and land-atmosphere interactions that impact rain and snow in the upper Colorado River watershed.”
SAIL is truly a broad, collaborative effort. ARM is co-managed by nine DOE national labs; Los Alamos National Lab leads the overall management and operations of the ARM mobile observatory while scientists from several other DOE labs, including Argonne, Brookhaven, Pacific Northwest, and Oak Ridge National Labs, work closely with Los Alamos and Berkeley Lab to support SAIL science and operations. A number of university researchers from Colorado State University, UC Berkeley, UC Irvine, UC Davis, Oregon State University, Indiana University, Pennsylvania State University, University of Utah, Desert Research Institute, and Boise State University are also involved in the research.
The instruments are mostly housed in large containers sited in the picturesque mountain town of Gothic, Colorado, an old mining town near Crested Butte, Colorado. The facility is hosted by the Rocky Mountain Biological Laboratory, which is dedicated to research on high-altitude ecosystems. A staff of three technicians will monitor the instruments around the clock.
“This is a profound and incredibly unique opportunity and represents a first-of-its-kind experiment in mountainous systems worldwide, bridging the processes from the atmosphere all the way down to bedrock,” said Berkeley Lab scientist Ken Williams, the lead on-site researcher for SAIL.
CAPTION
On July 1, 2021, Heath Powers, site manager for the second ARM Mobile Facility, helps set up radiometers for ARM’s Surface Atmosphere Integrated Field Laboratory (SAIL) field campaign in Gothic, Colorado. To his right is site technician Wessley King. The SAIL campaign, which will run from September 2021 to June 2023, will provide insights into mountainous water-cycle processes. Data from the radiometers will be used to help determine the site’s surface energy balance.
CREDIT
David Chu, Los Alamos National Laboratory
SAIL science: better models to answer tough questions
Having this volume of data at a wide range of spatial and temporal scales will allow scientists to begin to understand the physical processes that may affect mountain hydrology and answer questions such as how dust, wildfire, hot drought, tree mortality, and other phenomena might affect the watershed. Ultimately, the data will be fed into Earth system models so they can “get the water balance right.”
“Our models that predict what future water is going to be – their resolution is now about 100 kilometers [62 miles], but there's a lot of activity that happens in 100 kilometers, a lot of terrain variability, a lot of differences in precipitation, and surface and subsurface processes,” Feldman said. “So really the question is, what are all the details that need to go into those big models, so that we can get them to get the water balance right? And that's why this is really exciting – we’ll be measuring the inputs and the outputs at a fundamental level to develop a benchmark dataset for the scientific community to evaluate and improve their models.”
DOE’s Atmospheric System Research (ASR) program works closely with ARM to improve understanding of the key processes that affect the Earth’s radiative balance and hydrological cycle.
“ASR research projects during the SAIL campaign will help us learn more about the cloud, aerosol, precipitation, and radiation processes that affect the water cycle in the upper Colorado River watershed,” said Jeff Stehr, a DOE Program Manager for ASR. “Ultimately, this work will help us improve climate models so that they can be used to better understand, predict, and plan for threats to water resources in the arid West and globally.”
SAIL leverages the substantial efforts that Berkeley Lab has already undertaken in this area: it has been leading field studies at the East River watershed of the Colorado Upper Gunnison Basin since 2014, as part of the DOE-funded Watershed Function Scientific Focus Area project. SAIL will build on that research effort, bringing together a wide range of scientific disciplines to create the world’s first bedrock-to-atmosphere mountain integrated field laboratory.
“To have hydrologists working with precipitation process scientists, aerosol researchers working with snow process researchers, that's a really important part here, and it's unique and exciting,” Feldman said.
Some of the practical questions the SAIL campaign could help answer include:
How do we plan for a future of low snow or snowfall changing to rainfall? “Our planning for the Colorado River is largely based on historical weather patterns that might be changing, from snow to rain,” Feldman said.
How do activities and disturbances in the forest affect water quality and water availability? “It’s not just about the total volume of water exiting these systems,” Williams said. “We’ll also be looking at how land activities – such as wildfire and forest management – affect the concentrations of constituents in the water and overall water quality.”
Will dams overflow? The U.S. Bureau of Reclamation, the federal agency charged with managing dams in the western U.S., will be using the new data coming in from the radar system to help with controlled dam and reservoir operations. Feldman noted: “There have been some pretty scary situations that have arisen when rain falls on snow. The Oroville Dam disaster [in California in 2017] is just one of many such examples.”
Additionally, one of the weather radars will be located at a ski area owned by Vail Resorts, a major Colorado ski resort, which could benefit outdoor enthusiasts as well as scientists. And the research will also be useful to organizations such as water utilities and the Bureau of Reclamation that are experimenting with weather modification technologies, such as cloud-seeding.
Other federal agencies join the bandwagon
All the data collected by SAIL will be freely available to researchers. What’s more, a bevy of researchers from other federal agencies are undertaking field campaigns in the area with complementary research efforts.
The National Oceanic and Atmospheric Administration (NOAA), a Department of Commerce agency, has launched a project called SPLASH, or the Study of Precipitation, the Lower Atmosphere and Surface for Hydrometeorology, to improve weather and water prediction in the Colorado mountains and beyond. It will also be making detailed atmospheric co-observations in the SAIL study area.
The U.S. Geological Survey (USGS), a Department of Interior agency, has developed an Upper Colorado Next Generation Water Observing System (NGWOS) to provide real-time data on water quantity and quality in more affordable and rapid ways than previously possible, and in more locations.
“It’s quite rare for a single research question, the future of water in the West, to integrate the research activities of investigators across multiple federal agencies,” Williams noted.
But the scale of the challenge, and the prospect of a low- to no-snow future, calls for nothing less than an all-hands-on-deck response by scientists. “We need to understand the range of risks that we’re facing moving forward,” Feldman said. “The term ‘no-analog future’ is a really big one for us.”
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Founded in 1931 on the belief that the biggest scientific challenges are best addressed by teams,Lawrence Berkeley National Laboratory and its scientists have been recognized with 14 Nobel Prizes. Today, Berkeley Lab researchers develop sustainable energy and environmental solutions, create useful new materials, advance the frontiers of computing, and probe the mysteries of life, matter, and the universe. Scientists from around the world rely on the Lab’s facilities for their own discovery science. Berkeley Lab is a multiprogram national laboratory, managed by the University of California for the U.S. Department of Energy’s Office of Science.
DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visitenergy.gov/science.
IMAGE: THIS ILLUSTRATION SHOWS A PALEOARTIST'S RECONSTRUCTION OF THE THREE EXTINCT RHINOCEROS SPECIES WHOSE GENOMES WERE SEQUENCED AS PART OF THE STUDY. IN THE FOREGROUND IS A SIBERIAN UNICORN (ELASMOTHERIUM SIBIRICUM), AND CLOSE BEHIND ARE TWO MERCK’S RHINOCEROSES (STEPHANORHINUS KIRCHBERGENSIS). IN THE FAR BACKGROUND IS A WOOLLY RHINOCEROS (COELODONTA ANTIQUITATIS).view more
CREDIT: BETH ZAIKEN
There’s been an age-old question going back to Darwin’s time about the relationships among the world’s five living rhinoceros species. One reason answers have been hard to come by is that most rhinos went extinct before the Pleistocene. Now, researchers reporting in the journal Cell on August 24 have helped to fill the gaps in the rhino evolutionary family tree by analyzing genomes of all five living species together with the genomes of three ancient and extinct species.
The findings show that the oldest split separated African and Eurasian lineages about 16 million year ago. They also find that—while dwindling populations of rhinos today have lower genetic diversity and more inbreeding than they did in the past—rhinoceroses have historically had low levels of genetic diversity.
“All eight species generally displayed either a continual but slow decrease in population size over the last 2 million years, or continuously small population sizes over extended time periods,” said Mick Westbury (@Mick2474) of the University of Copenhagen, Denmark. “Continuously low population sizes may indicate that rhinoceroses in general are adapted to low levels of diversity.”
This notion is consistent with an apparent lack of accumulated deleterious mutations in rhinos in recent decades. Westbury says that rhinos may have purged deleterious mutations in the last 100 years, allowing them to remain relatively healthy, despite low genetic diversity.
There were some challenges to overcome, says Shanlin Liu, China Agricultural University, Beijing. “When we decided to put together all the rhinoceroses’ data and conduct a comparative genomics study, we also confronted the ‘big data’ problem,” Liu explained.
The genome data represented different data types, in part due to the inclusion of both modern and ancient DNA. The team had to develop new analysis tools to take those differences into account. The new approaches and tools they developed can now be applied to studies in other taxonomic groups.
“However, we also find that present-day rhinos have lower genetic diversity, and higher levels of inbreeding, compared to our historical and prehistoric rhinoceros genomes,” he says. “This suggests that recent population declines caused by hunting and habitat destruction have had an impact on the genomes. This is not good, since low genetic diversity and high inbreeding may increase the risk of extinction in the present-day species.”
The findings do have some practical implications for rhino conservation, the re-searchers say.
“Now we know that the low diversity we see in contemporary individuals may not be indicative of an inability to recover, but instead a natural state of rhinoceros," Westbury says. “We can better guide recovery programs to focus on increasing population size rather than individual genetic diversity.”
“We hope that this will provide a framework to better understand where translocated populations may have arisen from, direct changes in genetic diversity, and whether any populations may have been lost forever because of humans,” Westbury said.
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The researchers received support from the European Research Council, the Independent Research Fund Denmark, the Australian Research Council, the Agencia Estatal de Investigación, the Howard Hughes Medical Institute, GENCAT, the Swedish Research Council, and Formas.
Cell (@CellCellPress), the flagship journal of Cell Press, is a bimonthly journal that publishes findings of unusual significance in any area of experimental biology, including but not limited to cell biology, molecular biology, neuroscience, immunology, virology and microbiology, cancer, human genetics, systems biology, signaling, and disease mechanisms and therapeutics. Visit: http://www.cell.com/cell. To receive Cell Press media alerts, contact press@cell.com.
IMAGE: EVERY YEAR, MORE THAN 1,000 TONS OF PLASTIC RAIN DOWN ONTO NATIONAL PARKS AND WILDERNESS AREAS IN THE WESTERN U.S. IN THIS WEEK’S EPISODE, WE TALK ABOUT WHERE THAT PLASTIC COMES FROM, AND WE LOOK FOR IT IN RAIN THAT FALLS ON WASHINGTON, D.C.: HTTPS://YOUTU.BE/HUAAURZKI6U.view more
CREDIT: THE AMERICAN CHEMICAL SOCIETY
WASHINGTON, Aug. 24, 2021 — Every year, more than 1,000 tons of plastic rain down onto national parks and wilderness areas in the western U.S. In this week’s episode, we talk about where that plastic comes from, and we look for it in rain that falls on Washington, D.C.: https://youtu.be/HUAaurZKi6U.
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The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.
To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.
IMAGE: WIND TURBINE RESPONSE TO WIND AND EARTHQUAKES.view more
CREDIT: XILULI DU
WASHINGTON, August 24, 2021 -- As China's economic development continues, energy demand is rising along with it. Meeting this energy demand via fossil fuels is becoming increasingly undesirable, because it poses environmental and climate risks.
One solution is to embrace renewable energy sources, such as wind power, and it has experienced fast growth within China during the past decade. But many wind farms are being built within regions of high seismic activity.
In Journal of Renewable and Sustainable Energy, by AIP Publishing, researchers from Changzhou University and Beijing University of Technology present their work exploring the dynamic behaviors of wind turbines subjected to combined wind-earthquake loading.
The group discovered that changes in the wind increase and decrease the response amplitude of the wind turbine under weak and strong earthquakes, respectively.
"The input angle of earthquakes influences the seismic response of wind turbines, because of the asymmetry of aerodynamic damping and blade stiffness," said Xiuli Du, a co-author from Beijing University of Technology. "The wind and earthquake ground motion both induce the vibration of wind turbines, especially the blades, which changes the aerodynamic load acting on the blades."
Modern large-scale wind turbines use variable speed and variable pitch control technology, which means their dynamic behavior is affected by the controller.
"Consequently, the dynamic response of wind turbines under wind-earthquake excitation shows the coupling effect of aeroservoelasticity -- the interactions between the inertial, elastic, and aerodynamic forces that occur when an elastic body is subjected to a fluid flow," said Du. "Wind and ground motion are also random vector fields, with complex time-domain and spatial uncertainties involved when combined."
Surprisingly, the researchers found the wind simultaneously exerts a dynamic loading and damping effect on the seismic response of wind turbines. So, they caution that considering only one of these two effects could lead to inaccurate or even erroneous conclusions.
"Our work can guide the determination of wind-earthquake combinations for the seismic design of wind turbines and directly help design wind turbine structures," said Du.
Wind turbine support towers located within seismically active areas of China do not typically include redundant supports, so if one fails, it may result in a collapse of the turbines.
"While converting wind energy into electricity, wind turbines are in the operational state for most of their service life, which makes it important to study the dynamic behavior of wind turbines under wind-earthquake loading," said Du.
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The article "Dynamic behaviors of wind turbines under wind and earthquake excitations" is authored by Renquang Xi, Piguang Wang, Xiuli Du, and Chengshun Xu. It will appear in Journal of Renewable and Sustainable Energy on Aug. 24, 2021 (DOI: 10.1063/5.0054746). After that date, it can be accessed at https://aip.scitation.org/doi/10.1063/5.0054746.
ABOUT THE JOURNAL
Journal of Renewable and Sustainable Energy is an interdisciplinary journal that publishes across all areas of renewable and sustainable energy relevant to the physical science and engineering communities. Topics covered include solar, wind, biofuels and more, as well as renewable energy integration, energy meteorology and climatology, and renewable resourcing and forecasting. See https://aip.scitation.org/journal/rse.
CREDIT: AIHUI CHEN, XIFENG LIU, HAIBIN ZHANG, HAO WU, DONG XU, BO LI AND CHENXI ZHAO
WASHINGTON, August 24, 2021 -- Biomass is attracting growing interest from researchers as a source of renewable, sustainable, and clean energy. It can be converted into bio-oil by thermochemical methods, such as gasification, liquefaction, and pyrolysis, and used to produce fuels, chemicals, and biomaterials.
In Journal for Renewable and Sustainable Energy, researchers from Heilongjiang Academy of Agricultural Machinery Sciences in China share their work on the physicochemical properties and antioxidant activity of wood vinegar and tar fraction in bio-oil produced from hazelnut shells pyrolysis at 400 degrees Celsius to 1,000 C.
Wood vinegar is often used in agricultural fields as insect repellent, fertilizer, and plant growth promoter or inhibitor, and can be applied as an odor remover, wood preservative, and animal feed additive.
"After these results, wood vinegar and tar obtained from residual hazelnut shells could be considered as potential source of renewable energy dependent on their own characteristics," said author Liu Xifeng.
The researchers found the wood vinegar and tar left over after burning the shells contained the most phenolic substances, which laid a foundation for the subsequent research on antioxidant properties.
The experiments were conducted in a tube furnace pyrolysis reactor, and hazelnut shells samples weighing 20 grams were placed in the waiting area of a quartz tube in advance. When the target temperature was reached and stable, the raw materials were pushed to the reaction region and heated for 20 minutes.
The biochar was determined as the ratio of pyrolytic char and biomass weight, and the bio-oil yield was calculated by the increased weight of the condenser.
To separate two fractions of bio-oil sufficiently, the liquid product was centrifuged at 3,200 revolutions per minute for eight minutes, and the aqueous fraction was called wood vinegar. The separated tar fraction remained stationary for 24 hours without the appearance of the aqueous phase.
The wood vinegar and tar were respectively stored in a sealed tube and preserved in a refrigerator at 4 C for experimental analysis, and the gas yield was calculated by considering their combined volume.
The researchers found the pyrolysis temperature had a significant effect on the yield and properties of wood vinegar and tar fraction in bio-oil obtained from hazelnut shells. Wood vinegar was the dominant liquid fraction with maximal yield of 31.23 weight percent obtained at 700 C, attributable to the high concentration of water.
This research sets the groundwork for further applications of bio-oil from waste hazelnut shell pyrolysis, and its application in antioxidant activity has been extended.
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The article "Influence of pyrolysis temperature on bio-oil produced from hazelnut shells: Physico-chemical properties and antioxidant activity of wood vinegar and tar fraction" is authored by Xifeng Liu, Aihui Chen, Haibin Zhang, Hao Wu, Dong Xu, Bo Li, and Chenxi Zhao. The article will appear in Journal of Renewable and Sustainable Energy on Aug. 24, 2021 (DOI: 10.1063/5.0051944). After that date, it can be accessed at https://aip.scitation.org/doi/10.1063/5.0051944.
ABOUT THE JOURNAL
Journal of Renewable and Sustainable Energy is an interdisciplinary journal that publishes across all areas of renewable and sustainable energy relevant to the physical science and engineering communities. Topics covered include solar, wind, biofuels and more, as well as renewable energy integration, energy meteorology and climatology, and renewable resourcing and forecasting. See https://aip.scitation.org/journal/rse.
Influence of pyrolysis temperature on bio-oil produced from hazelnut shells: Physico-chemical properties and antioxidant activity of wood vinegar and tar fraction
Kratom is part of the coffee family, used for centuries in Southeast Asia and Papua New Guinea for its pain-relieving and mildly stimulating effects Louis Anderson AFP
Bangkok (AFP)
Thailand on Tuesday decriminalised kratom, a tropical leaf long used as a herbal remedy but which some health regulators around the world have criticised as potentially unsafe.
Kratom -- scientific name Mitragyna speciosa -- is part of the coffee family, used for centuries in Southeast Asia and Papua New Guinea for its pain-relieving and mildly stimulating effects.
It has become increasingly popular in the United States, where the Food and Drug Administration (FDA) has warned against its use, citing risks of addiction and abuse.
The change to Thai law means "the general public will be able to consume and sell kratom legally", government spokesman Anucha Burapachaisri said in a statement, while more than 1,000 prisoners convicted of offences related to the drug will be freed.
A Thailand Development Research Institute study estimated that the decriminalisation will save authorities about 1.69 billion baht ($50 million) in prosecution costs.
Kratom stimulates the same brain receptors as morphine, though with much milder effects, and in Thailand, it is mainly used in the deep south, where Muslim workers use it for pain relief after manual labour.
It has not been subject to international restrictions, though the World Health Organization announced last month that it was examining whether kratom should be considered for control.
Phil Robertson of Human Rights Watch said the decriminalisation of kratom -- which is native to Thailand, Malaysia, Indonesia and Papua New Guinea -- was "welcome, and frankly long overdue".
"The legalisation of kratom in Thailand ends a legacy of rights-abusing criminalisation of a drug that has long been used in traditional, rural communities in the country," Robertson told AFP.
In Indonesia, kratom is legal but its status is under review, with some politicians pushing for it to be banned.
Kratom stimulates the same brain receptors as morphine, though with much milder effects Louis Anderson AFP
Thai lawmakers have shown some appetite for reforming the kingdom's harsh anti-drug laws in recent years.
In 2019, Thailand became the first Southeast Asian country to legalise medical marijuana, and the government has invested in the extraction, distillation and marketing of cannabis oils for use in the health industry.
But overcrowded Thai prisons are still packed with inmates handed long sentences for drugs offences -- possessing just a few methamphetamine pills can earn a decade in jail.
Jeremy Douglas of the United Nations Office on Drugs and Crime said Thailand is discussing and considering drug rehabilitation and diversion programmes for meth users to ease some pressure off the system and "also because it is more effective".
Carnivorous animals lack key genes needed to detect and respond to infection by pathogens, a study has found. Farming large numbers of carnivores, like mink, could allow the formation of undetected ‘disease reservoirs’, in which a pathogen could spread to many animals and mutate to become a risk to human health.
Research led by the University of Cambridge has discovered that carnivores have a defective immune system, which makes them likely to be asymptomatic carriers of disease-causing pathogens.
Three key genes in carnivores that are critical for gut health were found to have lost their function. If these genes were working, they would produce protein complexes called inflammasomes to activate inflammatory responses and fight off pathogens. The study is published today in the journal Cell Reports.
The researchers say that the carnivorous diet, which is high in protein, is thought to have antimicrobial properties that could compensate for the loss of these immune pathways in carnivores – any gut infection is expelled by the production of diarrhoea. But the immune deficiency means that other pathogens can reside undetected elsewhere in these animals.
“We’ve found that a whole cohort of inflammatory genes is missing in carnivores - we didn’t expect this at all,” said Professor Clare Bryant in the University of Cambridge’s Department of Veterinary Medicine, senior author of the paper.
She added: “We think that the lack of these functioning genes contributes to the ability of pathogens to hide undetected in carnivores, to potentially mutate and be transmitted becoming a human health risk.”
Zoonotic pathogens are those that live in animal hosts before jumping to infect humans. The COVID-19 pandemic, thought to originate in a wild animal, has shown the enormous damage that can be wrought by a novel human disease. Carnivores include mink, dogs, and cats, and are the biggest carriers of zoonotic pathogens.
Three genes appear to be in the process of being lost entirely in carnivores: the DNA is still present but it is not expressed, meaning they have become ‘pseudogenes’ and are not functioning. A third gene important for gut health has developed a unique mutation, causing two proteins called caspases to be fused together to change their function so they can no longer respond to some pathogens in the animal’s body.
“When you have a large population of farmed carnivorous animals, like mink, they can harbour a pathogen - like SARS-CoV-2 and others - and it can mutate because the immune system of the mink isn’t being activated. This could potentially spread into humans,” said Bryant.
The researchers say that the results are not a reason to be concerned about COVID-19 being spread by dogs and cats. There is no evidence that these domestic pets carry or transmit COVID-19. It is when large numbers of carnivores are kept together in close proximity that a large reservoir of the pathogen can build up amongst them, and potentially mutate.
