It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Friday, May 29, 2020
Canada immigration sharply curtailed by virus: study
AFP/File / Lars HagbergClosed gates are seen in Lansdowne, Ontario at the US-Canada border in March 2020
Canada had hoped to welcome a record wave of immigrants in 2020 but will likely take in approximately half the previously expected number of people due to the coronavirus pandemic, a study published Friday showed.
In March, the government announced that it planned to accommodate some 370,000 new permanent residents this year. But according to a new study by the Royal Bank of Canada, some 170,000 fewer immigrants are now likely to enter the country.
Ottawa announced its plan to allow a heightened number of immigrants just four days before Canada implemented travel restrictions that have virtually halted immigration.
In 2019, Canada set a record with 341,000 new permanent residents.
"We expect immigration levels to be down sharply in 2020," study author Andrew Agopsowicz said. "A recovery in 2021 will depend in part on the course of the pandemic."
Repercussions from the decrease will be felt throughout the economy, he said, given Canada's dependence on foreign labor and its aging population.
Some of the worst-off areas will be industries with labor shortages, urban rental and housing markets, and universities, according to the report.
"Canada will need a younger and growing population to maintain growth and support the unprecedented expansion of the fiscal deficit that came in response to the crisis," Agopsowicz said.
Only foreigners with permanent resident status or a study permit approved before March 18 are allowed in the country. Already in March, 30 percent fewer people gained permanent residency compared with the previous year.
"If these restrictions last all summer, we expect to see 170,000 fewer permanent residents entering the country in 2020 than planned," Agopsowicz said.
Virus-battered Italy faces worst recession since WWII
AFP / ANDREA PATTAROItaly was the first European country to be hit by the pandemic and imposed a strict two-month lockdown which paralysed much of the country's economic activity
Facing its deepest recession since World War II and with business confidence collapsing, the coronavirus pandemic is hitting Italy's economy hard.
Business confidence in the eurozone's third largest economy in May plummeted to its lowest level since official statistics institute ISTAT started the index in March 2005.
The figure is "alarming", said small business federation Confesercenti.
"The health and economic emergency has swept businesses away, especially in shops, services and tourism," it said.
Its members are particularly concerned "by the lack of liquidity necessary to pay costs and salaries... we are close to a point of no return and that's why the measures decided by the government (loan guarantees, SME subsidies) must be operational immediately," said federation head Patrizia De Luise.
"We need to reduce bureaucracy and accelerate and simplify procedures, because if support is delayed again, many businesses will have no option but to stop," she said.
The government last week accused banks of not acting quickly enough, but they said that they had already passed on around 400,000 loan requests worth more than 18 billion euros ($20 billion) to the state-backed Central Guarantee Fund.
- A million jobs threatened -
Italy was the first European country to be hit by the pandemic and imposed a strict two-month lockdown which paralysed much of the country's economic activity.
As a result, the country is set for a drop in GDP of between nine and 13 percent, the Bank of Italy said on Friday.
Data also showed that the economy shrank 5.3 percent in the first quarter -- worse than the 4.7 percent initially estimated.
It had not seen such an "exceptional" decline in the first quarter since 1995, ISTAT said.
This year's losses could amount to 170 billion euros, equivalent to the GDP of Veneto, Italy's third biggest industrial region, a Mediobanca study said.
The head of the country's main business confederation Cofindustria, Carlo Bonomi, said that up to a million jobs could be threatened nationwide.
"We're waiting for figures at the end of May but indications are that between 700,000 and a million jobs are in danger," he said.
"Jobs are only created if there is growth, innovation, investment. The car manufacturing crisis can't be solved with subsidies or furloughing. You solve it by looking to the future, by investing in new technologies," he said.
Italy is set to be the main beneficiary of a European Union 750-billion-euro recovery plan but it still may not be enough.
- No aid -
Italian citizens are slightly more optimistic, but far from celebrating. The pandemic has killed over 30,000 people.
Consumer confidence went from 100.1 points in May to 94.3 in March, its lowest level since December 2013.
While the state has paid for furloughs or handouts for those no longer able to work, many have slipped through the net.
They include Eleonora Fogliacco, 35, a fitness and swimming teacher in Lombardy, the hardest hit region where gyms were ordered closed at the end of February.
"I didn't qualify for the 600-euro monthly government handout because I earned more than 10,000 euros last year," she told AFP.
"During the crisis I had peaceful days and days when I felt completely lost, without any state help. I could no longer see the future and I didn't know what to hold onto," she said.
"I don't buy anything. I depend on my partner for the shopping," said Fogliacco.
"This situation has changed everybody's way of life (and) everything will be very complicated" in the future, she added.
According to a Confcommercio-Censis poll published on Tuesday, 53 percent of Italian families see their future negatively and 68 percent see the country's future negatively.
Because of lockdown, 42 percent of families have had to reduce their work and income, 26 percent have stopped work and 24 percent have been furloughed.
Six out of 10 families fear losing a job, as a result of which 28 percent have decided to take no holidays nor long weekends.
Material and genetic resemblance in the Bronze Age Southern Levant
A team around Ron Pinhasi at the University of Vienna carried out a detailed analysis of ancient DNA of individuals from the Bronze Age Southern Levant known as 'Canaanites', to provide insights on the historical and demographic events that shaped the populations of that time and area. The scientists aimed at answering three basic questions: How genetically homogenous were the people from the Bronze Age Southern Levant, what were their plausible origins with respect to earlier peoples, and how much change in ancestry has there been in the region since the Bronze Age?
The team extracted and studied the DNA of people from five archaeological sites in the Bronze Age Southern Levant. They all share the "Canaanite" material culture and seem to be descending from two sources: People who lived in the region at earlier times and people who arrived from the area of the Caucasus-Zagros Mountains. These populations mixed at roughly equal proportions.
The data shows strong genetic resemblance, including a component from populations related to Chalcolithic Zagros and Early Bronze Age Caucasus introduced by a gene flow lasting at least until the late Bronze Age and affecting modern Levantine population architecture. These groups also harbor ancestry from sources that cannot fully be modeled with available data, highlighting the critical role of post-Bronze-Age migrations into the region over the past 3,000 years. The study provides evidence that the movement of Caucasus/Zagros people is already evident 4,500 years ago and likely started even earlier. This movement continued (although not necessarily continuously) throughout the Bronze Age.
"Populations in the Southern Levant during the Bronze Age were not static. Rather, we observe people movements over long periods of time - not necessarily continuously - from the northeast of the Ancient Near East into the region. The Canaanites are culturally and genetically similar. In addition, this region has witnessed many later population movements, with people coming from the northeast, from the south and from the west", says Ron Pinhasi.
The area at the site which supplied most of the samples for the aDNA study (the picture shows the relevant layers, dating to the MB III-LB I.
From the viewpoint of archaeology and history of the Ancient Near East, the team was surprised to see the strength of the Caucasus/Zagros component in the population of the Bronze Age, and that migration from this area continued as late as the second millennium BCE. According to archaeological findings, the Bronze Age Southern Levant was divided into city-states, which present similar material culture. Now it can be concluded that similarity between these populations extends also to genetics, showing that it is a case of cultural unity associated with shared ancestry. "Our results provide a comprehensive genetic picture of the primary inhabitants of the Southern Levant during the second millennium BCE", says Pinhasi.
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Publication in Cell:
Agranat-Tamir et al., The Genomic History of the Bronze Age Southern Levant, Cell, May 28, 2020. DOI: 10.1016/j.cell.2020.04.024
Tackling airborne transmission of COVID-19 indoors
UNIVERSITY OF SURREY
Preventing airborne transmission of Covid-19 should be the next front of the battle against the virus, argue experts from the University of Surrey.
In a study published by the City and Environment Interaction journal, scientists from Surrey's Global Centre for Clean Air Research (GCARE), together with partners from Australia's Queensland University and Technology, argue that the lack of adequate ventilation in many indoor environments - from the workplace to the home - increases the risk of airborne transmission of Covid-19.
Covid-19, like many viruses, is less than 100mn in size but expiratory droplets (from people who have coughed or sneezed) contain water, salts and other organic material, along with the virus itself. Experts from GCARE and Australia note that as the water content from the droplets evaporate, the microscopic matter becomes small and light enough to stay suspended in the air and over time the concentration of the virus will build up, increasing the risk of infection - particularly if the air is stagnant like in many indoor environments.
The study highlights improving building ventilation as a possible route to tackling indoor transmission of Covid-19.
Professor Prashant Kumar, lead author and the Director of the GCARE at the University of Surrey, said: "These past months, living through the Covid-19 crisis, has been truly unprecedented, but we must turn this global tragedy into an opportunity to better prepare for similar threats. An improved indoor ventilation is an important step that can be taken to reduce the risk of infection. However, more must be done to recognise and understand airborne transmission of Covid-19 and similar viruses, to minimise the build-up of virus-laden air in places typically containing high densities of people."
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Note to editors
The full paper: Could fighting airborne transmission be the next line of defence against COVID-19 spread?
Gap between rich, poor neighborhoods growing in some cities
Study of Columbus shows deepening polarization
OHIO STATE UNIVERSITY
IMAGE: HOUSING PRICES REBOUNDED IN BEXLEY AFTER THE GREAT RECESSION, BUT DIDN'T IN LINDEN. THE RESULTS SHOW DEEPENING POLARIZATION OF NEIGHBORHOOD VALUES IN COLUMBUS. view more
CREDIT: OHIO STATE UNIVERSITY, CENTER FOR URBAN AND REGIONAL ANALYSIS
New research provides insight into how housing prices and neighborhood values have become polarized in some urban areas, with the rich getting richer and the poor becoming poorer.
The results of the study, done in Columbus, Ohio, suggest that some of the factors long thought to impact neighborhood values - such as the distance to downtown, nearby highways, or attractions such as city parks - no longer matter much to changing housing prices in an area.
Instead, what drives neighborhood values are the unique, local amenities and characteristics of each area, such as local businesses, schools, crime rates and social networks.
And these features are self-reinforcing over time, said Jinhyung Lee, lead author of the study and graduate student in geography at The Ohio State University.
"Over 15 years, we see the divide between rich and poor neighborhoods getting deeper and wider in Columbus," Lee said.
The results suggest that government officials need to provide direct investments in low-valued neighborhoods to break the self-reinforcing negative effects, he said.
The study, led by researchers in Ohio State's Center for Urban and Regional Analysis (CURA), was published online recently in the journal Geographical Analysis.
Researchers used a high-resolution housing transactions database provided by the firm CoreLogic that allowed them to analyze nearly 480,000 home sales in the Columbus area between 2000 and 2015 to see how housing values have changed in specific neighborhoods.
Traditionally high-valued neighborhoods, which include suburbs (Upper Arlington, Grandview Heights, Bexley), became even more prosperous over the 15 years. Low-valued neighborhoods in the city (Linden, Franklinton) lost value.
The study captured the impact of the Great Recession on the value of houses in the Columbus area.
Housing prices dropped significantly in all parts of the city between 2008 and 2011, as they did throughout the United States. But the recovery did not happen equally throughout the Columbus area.
"Areas that traditionally had high housing prices regained much of the recession-induced loss, while other areas did not," Lee said.
"This unequal recovery made the polarized neighborhood values in Columbus even worse."
Overall, high housing prices were clustered near the center of the city and in suburban areas, Lee said.
"In contrast, the areas between the city center and suburban areas had low housing prices, resulting in a donut-shaped housing price landscape," he said.
The researchers calculated how far each neighborhood was from major Columbus amenities, including downtown, the nearest rivers, Ohio State's campus, the Columbus Zoo and the closest city-maintained park.
Analysis of the data showed that the distance from these features didn't shape patterns of neighborhood value over time, as some long-standing theories indicated they might, Lee said.
"This suggests that the reasons why neighborhoods are becoming more polarized has more to do with what is going on each individual neighborhood," he said.
Results showed that the location of major highways in Columbus, particularly U.S. Interstate 71, shaped polarization. Many of the richer neighborhoods are clustered west of I-71, with the poorer neighborhoods to the east.
"This is consistent with work by public policy and urban history scholars documenting that highways were constructed to purposefully cut through poorer, minority neighborhoods and avoid more affluent ones," Lee said.
"It has served to further reinforce patterns of economic segregation."
The findings suggest that low-value neighborhoods are unlikely to improve over time on their own, according to Lee.
"Our research underscores the need for direct investments in neighborhoods to spark a development process," he said.
For example, governments can invest in job market training programs in low-value neighborhoods to offset the self-reinforcing negative effects that can make these neighborhoods worse off over time, he said.
Lee said he expects similar polarizing trends exist in neighborhood values in cities across the nation. But the exact ways they get there may differ depending on factors like the size of the cities and their levels of decentralization.
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Co-authors on the study were Nicholas Irwin, assistant professor of economics at the University of Nevada, Las Vegas; Elena Irwin, professor of agricultural, environmental and development economics and the Sustainability Institute at Ohio State; and Harvey Miller, professor of geography and director of CURA at Ohio State.
Hydropower plants can support solar and wind power, rather unpredictable by nature, in a climate-friendly manner. A new study in the scientific journal Nature Sustainability has now mapped the potential for such "solar-wind-water" strategies for West Africa: an important region where the power sector is still under development, and where generation capacity and power grids will be greatly expanded in the coming years. "Countries in West Africa therefore now have the opportunity to plan this expansion according to strategies that rely on modern, climate-friendly energy generation," says Sebastian Sterl, energy and climate scientist at Vrije Universiteit Brussel and KU Leuven and lead author of the study. "A completely different situation from Europe, where power supply has been dependent on polluting power plants for many decades - which many countries now want to rid themselves of."
Solar and wind power generation is increasing worldwide and becoming cheaper and cheaper. This helps to keep climate targets in sight, but also poses challenges. For instance, critics often argue that these energy sources are too unpredictable and variable to be part of a reliable electricity mix on a large scale.
"Indeed, our electricity systems will have to become much more flexible if we are to feed large amounts of solar and wind power into the grid. Flexibility is currently mostly provided by gas power plants. Unfortunately, these cause a lot of CO2 emissions," says Sebastian Sterl, energy and climate expert at Vrije Universiteit Brussel (VUB) and KU Leuven. "But in many countries, hydropower plants can be a fossil fuel-free alternative to support solar and wind energy. After all, hydropower plants can be dispatched at times when insufficient solar and wind power is available."
Hydropower plant in Gui, Ghana.
The research team, composed of experts from VUB, KU Leuven, the International Renewable Energy Agency (IRENA), and Climate Analytics, designed a new computer model for their study, running on detailed water, weather and climate data. They used this model to investigate how renewable power sources in West Africa could be exploited as effectively as possible for a reliable power supply, even without large-scale storage. All this without losing sight of the environmental impact of large hydropower plants.
"This is far from trivial to calculate," says Prof. Wim Thiery, climate scientist at the VUB, who was also involved in the study. "Hydroelectric power stations in West Africa depend on the monsoon; in the dry season they run on their reserves. Both sun and wind, as well as power requirements, have their own typical hourly, daily and seasonal patterns. Solar, wind and hydropower all vary from year to year and may be impacted by climate change. In addition, their potential is spatially very unevenly distributed."
West African Power Pool
The study demonstrates that it will be particularly important to create a "West African Power Pool", a regional interconnection of national power grids. Countries with a tropical climate, such as Ghana and the Ivory Coast, typically have a lot of potential for hydropower and quite high solar radiation, but hardly any wind. The drier and more desert-like countries, such as Senegal and Niger, hardly have any opportunities for hydropower, but receive more sunlight and more wind. The potential for reliable, clean power generation based on solar and wind power, supported by flexibly dispatched hydropower, increases by more than 30% when countries can share their potential regionally, the researchers discovered.
All measures taken together would allow roughly 60% of the current electricity demand in West Africa to be met with complementary renewable sources, of which roughly half would be solar and wind power and the other half hydropower - without the need for large-scale battery or other storage plants. According to the study, within a few years, the cost of solar and wind power generation in West Africa is also expected to drop to such an extent that the proposed solar-wind-water strategies will provide cheaper electricity than gas-fired power plants, which currently still account for more than half of all electricity supply in West Africa.
Better ecological footprint
Hydropower plants can have a considerable negative impact on local ecology. In many developing countries, piles of controversial plans for new hydropower plants have been proposed. The study can help to make future investments in hydropower more sustainable. "By using existing and planned hydropower plants as optimally as possible to massively support solar and wind energy, one can at the same time make certain new dams superfluous," says Sterl. "This way two birds can be caught with one stone. Simultaneously, one avoids CO2 emissions from gas-fired power stations and the environmental impact of hydropower overexploitation."
Left: current policy plans Right: West African Power Pool scenario
Global relevance
The methods developed for the study are easily transferable to other regions, and the research has worldwide relevance. Sterl: "Nearly all regions with a lot of hydropower, or hydropower potential, could use it to compensate shortfalls in solar and wind power." Various European countries, with Norway at the front, have shown increased interest in recent years to deploy their hydropower to support solar and wind power in EU countries. Exporting Norwegian hydropower during times when other countries undergo solar and wind power shortfalls, the European energy transition can be advanced.
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Changes in cropping methods, climate, decoy pintail ducks into an ecological trap
Important waterfowl species struggling with conditions in the Prairie Pothole Region
PENN STATE NEWS RELEASE
IMAGE: PINTAILS ARE NOT THRIVING LIKE OTHER SPECIES OF DABBLING DUCKS, AND RESEARCHERS THINK THAT'S BECAUSE THEY ARE BEING 'MISLED' BY MODERN CROPPING METHODS AND CLIMATE CHANGE INTO CHOOSING RISKY NESTING... view more
CREDIT: F. GREENSLADE-DELTA WATERFOWL
After a severe drought gripped the Prairie Pothole Region of the U.S. and Canada in the 1980s, populations of almost all dabbling duck species that breed there have recovered. But not northern pintails. Now, a new study by a team of researchers suggests why -- they have been caught in an ecological trap.
The Prairie Pothole region straddles the U.S.-Canada border and sprawls from central Iowa in the south to Alberta in the north, covering a large swath of Minnesota, South Dakota, North Dakota, Manitoba and Saskatchewan in between.
"With increasing cropland cover in the region, pintails have been selecting for cropland over scarce alternative nesting habitat, probably because it is similar to the native mixed-grass prairie they evolved to nest in," said lead researcher Frances Buderman, Penn State. "That behavior results in fewer pintails the following year due to nest failures from predation and agricultural practices."
The U.S. Fish and Wildlife Service's North American Waterfowl Management Plan calls for more than 4 million pintails, but recent estimates are only half of that. The reason pintails are not thriving like other dabbling ducks, according to Buderman, assistant professor of quantitative wildlife ecology in the College of Agricultural Sciences, is that they are being "misled" by modern cropping methods and climate change into choosing risky nesting habitat.
Also called puddle ducks, dabbling ducks frequent shallow waters such as flooded fields and marshes. They feed by tipping up rather than diving. There are 38 species of dabbling ducks -- they float high in the water and are swift fliers.
By their very nature, pintails may be vulnerable to the ecological trap, Buderman explained. Despite being an early-spring nester -- a quality that typically would allow for reproductive "plasticity" to climatic conditions -- pintails have demonstrated inflexible breeding behavior, such as being unwilling or unable to delay nest initiation and being less likely to renest than most other waterfowl.
"Inflexible breeding behavior may result in greater vulnerability to unpredictable weather events and changes in climactic conditions," she said. And given their preference for nesting among landscapes of grass-like, low-lying cover, pintails readily nest in fields of stubble in untilled agricultural fields. "Unlike other ducks that generally avoid nesting in stubble, pintails in the Prairie Pothole Region commonly select crop stubble nest sites and often select it over remnant patches of grass and other cover."
Pintails often initiate nests before remaining stubble fields are worked by farmers in the spring, making nests vulnerable to mechanical spring tilling and planting of remaining standing stubble, Buderman explained. That can destroy a large percentage of initial nests. Exacerbating the effect of pintail selections over time, the amount of land in the Prairie Pothole Region annually tilled for spring-seeded crops has increased by approximately 34% since 1959.
For reasons not clearly understood by wildlife scientists, pintails appear to be particularly sensitive to changes in the number of productive, small wetlands that have occurred across the Prairie Pothole Region.
Dabbling duck incoming
Another factor that is contributing to pintails' decline, researchers contend, is a trend in some areas of the Prairie Pothole Region to manipulate drainage to consolidate surface water into larger and deeper wetlands that dry out less frequently and have more surface-water connections to other wetlands.
Those drainage practices make mowing around ponds easier for farmers, and most waterfowl species have coped thus far, but it hasn't been good for pintails. Wildlife scientists suspect the birds need the smaller, shallower, ephemeral ponds with which they evolved. For reasons not clearly understood, pintails appear to be particularly sensitive to changes in the number of productive, small wetlands that have occurred across the Prairie Pothole Region.
Buderman pointed out that funding partner Delta Waterfowl is working hard to restore these valuable seasonal wetlands on the U.S. side of the region by establishing a Working Wetlands program in the U.S. Department of Agriculture via the federal farm bill.
To reach their conclusions, researchers used more than 60 years of data from the U.S. Fish and Wildlife Service and the Canadian Wildlife Service, which have monitored spring population sizes for North American waterfowl since 1955. They published their results in the Journal of Animal Ecology,
That information is organized into regions that reflect both habitat differences and political boundaries. For many decades, waterfowl have been counted on both sides of the border by aerial crews flying fixed-wing aircraft along established transect lines at low altitude, while simultaneously, ground counts are conducted at ponds on a subset of air-surveyed areas.
To analyze population dynamics, researchers developed a complex model to deal with a huge dataset that took days to run on a powerful computer, which calculated a "breeding pintail count" for the survey period. The model -- which also took into account precipitation, climatic conditions during the breeding season and pond dynamics -- allowed researchers to identify the relative influence of long-term changes in climate and land use on both the selection and quality of habitat for pintails in the Prairie Pothole Region. Pintails are one of 38 species of dabbling ducks, also known as puddle ducks. They frequent shallow waters such as flooded fields and marshes, and they feed by tipping up rather than diving. They float high in the water and are swift fliers.
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Also involved in the research were Jim Devries, Institute for Wetland and Waterfowl Research, Ducks Unlimited Canada, and David Koons, Department of Fish, Wildlife, and Conservation Biology, Colorado State University.
Delta Waterfowl, California Department of Water Resources and the James C. Kennedy Endowment for Wetland and Waterfowl Conservation at Colorado State University funded this research.
Survey identifies learning opportunities related to health impacts of climate change
COLUMBIA UNIVERSITY'S MAILMAN SCHOOL OF PUBLIC HEALTH
An international survey of Global Consortium on Climate and Health Education (GCCHE) membership found that the majority of members--health professions schools and programs, including medical, nursing, and public health--offer learning opportunities related to the health impacts of climate change, yet many also encountered challenges in instituting or developing curricula. The results of the survey provide a baseline assessment of the state of climate-health education internationally among health professions institutions. Results of the survey by Columbia University Mailman School of Public Health researchers appear in the journal JAMA Network Open.
The survey suggests there exist a range of educational offerings on climate-health, including sessions, courses, programs, or post-doctoral positions. Some schools have offered climate-health education for several years, some are just now adding content, and others do not include any content on the subject. While many schools are discussing adding climate-health educational offerings, there are still considerable gaps in offerings at many institutions as well as challenges that extend beyond the institutional level, such as political and funding priorities that might lead to lack of staff time and materials to support the training.
Conducted in 2017 and 2018, the survey was completed by 84 health professions institutions internationally. Among respondents, 63% offer climate-health education, most commonly as part of a required core course (76%). Sixty-one of 82 respondents (74%) reported additional climate-health offerings are under discussion, 42 of 59 (71%) encountered some challenges trying to institute the curriculum, and most have received a positive response to adding content mainly from students (39 of 58 (67%)), faculty (35 of 58 (60%)), and administration (23 of 58 (40%)).
The article's authors write that opportunities exist to facilitate the integration of climate-health curricula, such as working with students, faculty, and members of administration that are interested in this topic. In order to facilitate this integration, institutions can look to online resources, groups, and networks to provide guidance and information to develop curricula.
"We suggest that health professions schools include this content in their curricula and that awareness as well as financial support, resources, and expertise increase to help in its uptake," write study authors Brittany Shea, MA, Kim Knowlton, DrPH, and Jeffrey Shaman, PhD. "Climate change may be affecting health in a variety of ways with increasing consequences. Health professionals, including those in public health, nursing, and medical services, should be educated on how to prevent, mitigate, and respond to factors associated with climate change that may be associated with health in a negative way."
Brittany Shea is project director for GCCHE. Kim Knowlton is assistant professor of environmental health sciences and senior scientist with the Natural Resources Defense Council. Jeffrey Shaman directs GCCHE and the Columbia Mailman School Climate and Health Program; he is a professor of environmental health sciences.
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The study was made possible with financial support from The Rockefeller Foundation and ClimateWorks Foundation. Jeffrey Shaman and Columbia University disclosed partial ownership of SK Analytics. Shaman also disclosed providing paid consultant services for Merck and Business Network International.
About the Global Consortium on Climate and Health Education
The Global Consortium on Climate and Health Education (GCCHE) was launched in 2017 by faculty at Columbia University Mailman School of Public Health with the vision that all health professionals throughout the world will be trained to prevent, mitigate, and respond to the health impacts of climate change and other planetary changes that impact human health and well-being. To advance progress toward this goal, the GCCHE created a virtual town square across all health professions by bringing together member institutions to share best scientific and educational practices; develop global standards for knowledge and practice on the health impacts of climate change that all graduates of health professions schools should possess, as well as share resources that member institutions can use for this purpose; build a pipeline of health professionals who focus their work on the health impacts of climate change; and support the development of global academic partnerships to foster mutual learning, particularly in under-resourced countries. GCCHE currently includes over 200 member institutions in over 30 countries on six continents, representing institutions with over an estimated 150,000 students. The GCCHE has received financial support from several foundations, including The Rockefeller Foundation and ClimateWorks Foundation. Representatives of health professions schools are invited to join the GCCHE h
Smart sponge could clean up oil spills
Highly porous sponge selectively soaks up oil, sparing water and wildlife
EVANSTON, Ill. -- A Northwestern University-led team has developed a highly porous smart sponge that selectively soaks up oil in water.
With an ability to absorb more than 30 times its weight in oil, the sponge could be used to inexpensively and efficiently clean up oil spills without harming marine life. After squeezing the oil out of the sponge, it can be reused many dozens of times without losing its effectiveness.
"Oil spills have devastating and immediate effects on the environment, human health and economy," said Northwestern's Vinayak Dravid, who led the research. "Although many spills are small and may not make the evening news, they are still profoundly invasive to the ecosystem and surrounding community. Our sponge can remediate these spills in a more economic, efficient and eco-friendly manner than any of the current state-of-the-art solutions."
The research was published yesterday (May 27) in the journal Industrial Engineering and Chemical Research.
Dravid is the Abraham Harris Professor of Materials Science and Engineering at Northwestern's McCormick School of Engineering. Vikas Nandwana, a senior research associate in Dravid's laboratory, is the paper's first author.
Oil spill clean-up is an expensive and complicated process that often harms marine life and further damages the environment. Currently used solutions include burning the oil, using chemical dispersants to breakdown oil into very small droplets, skimming oil floating on top of water and/or absorbing it with expensive, unrecyclable sorbents.
"Each approach has its own drawbacks and none are sustainable solutions," Nandwana said. "Burning increases carbon emissions and dispersants are terribly harmful for marine wildlife. Skimmers don't work in rough waters or with thin layers of oil. And sorbents are not only expensive, but they generate a huge amount of physical waste -- similar to the diaper landfill issue."
The Northwestern solution bypasses these challenges by selectively absorbing oil and leaving clean water and unaffected marine life behind. The secret lies in a nanocomposite coating of magnetic nanostructures and a carbon-based substrate that is oleophilic (attracts oil), hydrophobic (resists water) and magnetic. The nanocomposite's nanoporous 3D structure selectively interacts with and binds to the oil molecules, capturing and storing the oil until it is squeezed out. The magnetic nanostructures give the smart sponge two additional functionalities: controlled movement in the presence of an external magnetic field and desorption of adsorbed components, such as oil, in a simulated and remote manner.
The OHM (oleophilic hydrophobic magnetic) nanocomposite slurry can be used to coat any cheap, commercially available sponge. The researchers applied a thin coating of the slurry to the sponge, squeezed out the excess and let it dry. The sponge is quickly and easily converted into a smart sponge (or "OHM sponge") with a selective affinity for oil.
Vinayak and his team tested the OHM sponge with many different types of crude oils of varying density and viscosity. The OHM sponge consistently absorbed up to 30 times its weight in oil, leaving the water behind. To mimic natural waves, researchers put the OHM sponge on a shaker submerged in water. Even after vigorous shaking, the sponge release less than 1% of its absorbed oil back into the water.
"Our sponge works effectively in diverse and extreme aquatic conditions that have different pH and salinity levels," Dravid said. "We believe we can address a giga-ton problem with a nanoscale solution."
"We are excited to introduce such smart sponges as an environmental remediation platform for selectively removing and recovering pollutants present in water, soil and air, such as excess nutrients, heavy metal contaminants, VOC/toxins and others," Nandwana said. "The nanostructure coating can be tailored to selectively adsorb (and later desorb) these pollutants."
The team also is working on another grade of OHM sponge that can selectively absorb (and later recover) excess dissolved nutrients, such as phosphates, from fertilizer runoff and agricultural pollution. Stephanie Ribet, a Ph.D. candidate in Dravid's lab and paper coauthor is pursuing this topic. The team plans to develop and commercialize OHM technology for environmental clean-up.
Smart sponge selectively absorbs oil (on the left) while resisting water (on the right).
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The research, "OHM Sponge: A versatile, efficient and eco-friendly environmental remediation platform," was supported by the National Science Foundation. Stephanie Ribet, Roberto Reis, Yuyao Kuang and Yash More -- all from Northwestern -- coauthored the paper.
Editor's note: Dravid, Nandwana and Northwestern will have financial interests (equities, royalties) if the technology is commercialized.
AFP/File / Lars HagbergClosed gates are seen in Lansdowne, Ontario at the US-Canada border in March 2020
