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)
The American residential lawn is, for many, an iconic landscape and about half of homeowners in the US use fertilizer to keep their yards green and lush. Some proportion of the nitrogen in this fertilizer enters the broader environment, with negative consequences including algal blooms and deoxygenated waters. Peter Groffman and colleagues studied residential landscapes in the Baltimore, Maryland metropolitan area, which drains to the Chesapeake Bay, seeking to identify locations (hotspots) or times (hot moments) with disproportionately high rates of nitrogen export. The authors went to lawns in exurban, suburban, and college campus settings to measure nitrogen export during simulated rainfall events created by adding known amounts of water to actual lawns in the field. The authors also used household survey data collected by the Baltimore Ecosystem Study Long Term Ecological Research in 2003, 2011, and 2018—as well as their own push-to-web survey of 3,836 Baltimore area households. Nitrogen export dynamics of lawns show tremendous variation, although all export hotspots were found on fertilized rather than unfertilized lawns. Some 48% of 2018 survey respondents incorrectly believed that they did not live in a watershed, and more than 60% of web survey respondents did not know if nitrogen negatively affected area waterways. (It does.) Support for policies limiting fertilizer use was broadly high among surveyed households, with some types of restrictions even garnering support among those who fertilize their own lawns. About half of households are interested in converting lawns to features that reduce nitrogen export, such as rain gardens, if such conversions are subsidized and made as easy as possible. According to the authors, changing just 5-10% of suburban lawns to alternative landscaping could have a major effect on watershed-wide nitrogen export.
JOURNAL
PNAS Nexus
ARTICLE TITLE
“Hydro-bio-geo-socio-chemical interactions and the sustainability of residential landscapes”
ARTICLE PUBLICATION DATE
17-Oct-2023
U.S. groundwater is getting saltier—what that means for infrastructure, ecosystems, and human health
USGS DECADAL CHANGE IN GROUNDWATER QUALITY PROGRAM MAP SHOWING HOW CONCENTRATIONS OF PESTICIDES, NUTRIENTS, METALS, AND ORGANIC CONTAMINANTS IN GROUNDWATER ARE CHANGING DURING DECADAL PERIODS ACROSS THE UNITED STATES.
Pittsburgh, Pa., USA: Scientists from the U.S. Geological Survey (USGS) have been monitoring groundwater quality in wells across the country for more than three decades, looking for harmful chemicals or residual substances that may cause harm to ecosystems or humans. In all, they have measured up to 500 chemical constituents, including major ions, metals, pesticides, volatile organic compounds, fertilizers, and radionuclides.
Of these constituents, there have been significant increases of Na and Cl ions and dissolved solids—all related to salinity. Details and trends found in the multidecadal study will be presented at the Geological Society of America’s GSA Connects 2023 meeting on Wednesday, 18 October.
The study is currently part of the National Water Quality Network, continuing work that began in 1992 as part of the National Water Quality Assessment Project. “The original goal was to evaluate the status of water quality in the nation, including groundwater, surface water, and ecological health,” says Bruce Lindsey, a hydrologist with USGS. Over time, they focused on certain constituents that may have lingering detrimental effects.
The researchers sampled wells within three different network types: domestic areas, urban areas, and agricultural areas. Domestic wells, or private wells that are not regulated by the Environmental Protection Agency or a local municipality, represented medium depth aquifers and drinking water. Urban and agricultural wells were shallower, usually around 30 to 50 ft deep. “The purpose of [sampling] those were to understand the status and trends in the very shallowest water levels,” explains Lindsey. Those shallow wells acted as “sort of a sentinel of what might be moving deeper into the aquifer, so to speak.”
The team identified 82 networks, each with 20 to 30 wells, and identified 28 constituents to track that had levels of concern. Water was sampled every 10 years to track changes in chemical concentrations. These constituents and sampling results can be seen on the USGS’s interactive groundwater map, which shows decadal changes.
“If we look at all 28 constituents across all 82 networks, dissolved solids, chloride, and sodium had statistically significant increases more frequently than any other constituents that we have on our list,” says Lindsey. “If you look at the map, you’ll see patterns right away that jump out.”
One of these spots is the Northeastern and Upper Midwest regions, “particularly around urban areas where there’s cold weather and a lot of road salt,” says Lindsey. “We obtained data on road salt application and found correlations between these increases in chloride and sodium and dissolved solids with the road salt application rates.”
But another region also had elevated levels of Cl, Na, and dissolved solids: the arid regions of the country, especially in the southwest. These regions naturally have high salinity in the soil to begin with, but irrigation complicates the issue.
“When irrigating agriculture in arid regions, you get a lot of evaporation,” Lindsey explains. “So if the salinity of the irrigation water is relatively low, but a large percentage of it evaporates, [salinity levels] can become high.”
These rising levels of Na, Cl, and dissolved solids can cause multiple problems, starting with the environment. Many streams are fed by groundwater, and higher concentrations of chloride in the water can knock out the natural balance that aquatic life is used to. “[Rising levels] is something that can take 20, 30, 40 years to develop … which means that it can also take that long to recover if management of the sources of salinity changes,” says Lindsey.
Dissolved salt ions can also pose problems for infrastructure. As the salinity of groundwater increases, corrosivity can become an issue. Corrosive groundwater, if untreated, can dissolve lead and other metals from pipes and other components present in household plumbing.
Lastly, Lindsey and his colleagues have also discovered a unique issue related to rising salinity with implications for human health. In a sandy aquifer in southern New Jersey, they found that a mixture of low pH water and high salinity groundwater has mobilized the radium— a radioactive element which is harmful to humans.
“It goes back to road salt,” he says. “Road salt is increasing, causing sodium and chloride to increase, which is causing radium to increase.”
Lindsey notes that there seems to be increased awareness of the environmental effects of road salt, with trucks spreading less salt or municipalities switching to a lower-concentration brine. And while dead grass near salted roadways is a clear hint at an oversalting problem, Lindsey hopes that research like this will highlight other cascading impacts of increasing salinity in groundwater. “The fact that there may be streams that are not able to sustain aquatic life, or that your pipes might start corroding, or this other more rare issue where there's radium, shows there are other negative aspects [to rising groundwater salinity].”
An image of a USGS scientist collecting data.
CREDIT
U.S. Geological Survey
Increasing salinization of groundwater in the United States Contact: Bruce Lindsey, blindsey@usgs.gov 262: T96. Salinization of Freshwater Wed., 18 Oct. 2023, 1:35–1:55 p.m.
The Geological Society of America (https://www.geosociety.org) unites a diverse community of geoscientists in a common purpose to study the mysteries of our planet (and beyond) and share scientific findings. Members and friends around the world, from academia, government, and industry, participate in GSA meetings, publications, and programs at all career levels, to foster professional excellence. GSA values and supports inclusion through cooperative research, public dialogue on earth issues, science education, and the application of geoscience in the service of humankind.
###
Ocean circulation, ice melt and increasing tourism could all be contributing to Arctic microplastics
Scientists measured microplastic concentrations in the highly productive Barents Sea and suggest that ocean circulation, ice melt, tourism, inadequate waste management, shipping and fishing are all likely contributors.
Numerous studies have shown that global microplastic quantities in the marine environment are increasing, even in remote locations such as the Arctic.
The Barents Sea, which adjoins the Arctic Ocean, is one of the most productive oceanic areas in the world and home to an enormous diversity of organisms.
It is also a key route for Atlantic water flow into the Arctic Ocean and has been earmarked as a potential microplastic hotspot.
A new study, by scientists from Plymouth Marine Laboratory and the University of Exeter, explored large volume samples of sub-surface water collected from transects through the Barents Sea to quantify, characterise and determine distribution of microplastics in this region, with a focus on potential impacts to zooplankton.
Given that the Barents Sea is an area of high primary productivity and the size of microplastics overlapping with optimal prey size of zooplankton, it is considered likely that zooplankton within this region will be consuming microplastics, facilitating the entry of these anthropogenic particles into polar food webs.
Previous studies have shown that the ingestion of microplastic by zooplankton can negatively affect fertility and growth as well as alter the sinking velocity of their faeces; an important process that assists the transport of carbon and nutrients to deeper waters and the seabed.
Overall, the mean microplastic quantity in the eastern Barents Sea was 0.011 microplastics per cubic metre (range: 0.007 – 0.015 m-3).
Microplastics were found in higher abundances nearer land mass at the southern end of the transect and northwards towards the ice edge, recording 0.015 microplastics m-3 during both transect legs.
Microplastics were predominantly fibrous (92.1%) and typically blue (79%) or red (17%) in colour.
A range of polymers were identified including polyester (3.8%), copolymer blends (2.7%), elastomers (7.1%) and acrylics (10.6%), with the vast majority observed from anthropogenically modified cellulose, such as rayon.
The study concludes that while it is not possible to determine the source of the plastic through this study, the highest concentrations were found close to sources of anthropogenic pollution and ice melt, which are known repositories of marine microplastic.
The possibility of local input is also likely; as tourism in Svalbard continues to increase, the lack of adequate waste infrastructure will result in increased leakage into the surrounding waters.
Increased tourism, paired with other local sources including wastewater input, shipping activities and fishing, could explain the higher levels of microplastic abundance towards the coastline compared to further offshore.
Heather Emberson-Marl, lead author on the paper and MSc student with the University of Exeter and Plymouth Marine Laboratory, said: “It is apparent that microplastic data from the Arctic is limited and this study will act as a reference point for further research.
“Additionally, sampling methods between studies of microplastics within the Arctic vary and the differing units of measurement used in previous research make it difficult to draw comparisons.
“We recommend that future studies should strive for a standardised sampling protocol to allow for direct comparisons and more robust conclusions on the ecological and toxicological effects on the Arctic’s marine biology.”
Dr Rachel Coppock, Marine Ecologist at Plymouth Marine Laboratory and co-author on the study, commented: “The Arctic region is remote and most of us might imagine that it is a pristine natural wonder.
“But once microplastics enter the marine environment they are transported on currents, often from populated areas many thousands of miles away, ending up far from the source and in the case of the high Arctic, may become trapped in sea ice and released during the spring melt.
“Warming seas are causing greater sea ice melt, potentially releasing further microplastics and adding another layer of complexity to marine life adapting to a changing world.”
This study was partly funded by the UK’s Natural Environment Research Council (NERC) through the GW4+ internship and the Changing Arctic Ocean Sediments grant.
DURHAM, N.H.—U.S. Climate policies can offer options for putting climate change efforts into place that solve environmental problems like excessive carbon dioxide in the atmosphere created by greenhouse gas emissions. Research led by the University of New Hampshire took a closer look at what would happen to agriculture if there was an extra cost, or so-called social cost, added to fossil fuels, which are essential for making fertilizer used in farming. They found that while CO2 emissions would decline by as much as 50%, the cost of fertilizer would rise leading to a significant benefit on water quality by lessening fertilizer runoff contributing to the Gulf of Mexico’s dead zone—a low-oxygen area that struggles with harmful algal blooms that threatens marine life.
“Excessive fertilizer use creates a growing number of water quality concerns so we wanted to explore the consequences of applying a social cost to fossil fuel prices which should reduce fertilizer use and decrease the amount of runoff going into the Mississippi River Basin and on to the Gulf of Mexico, an important fishery in the U.S.,” said Shan Zuidema, research scientist at UNH’s Earth System Research Center and lead author. “Our models showed that with this climate policy, U.S. carbon emissions could significantly decline but we could also see about a 3% to 4% reduction of the Gulf of Mexico dead zone in an average year.”
In the study, published in the journal Proceedings of the National Academy of Sciences (PNAS), researchers from UNH, Purdue University and the University of Wisconsin-Madison used four different models that looked at various factors making up the world economy. They focused on data from the global economy, U.S. agricultural economies, agroecology and hydrology/water quality to capture the impacts of the climate change mitigation policy on agriculture and the resulting water quality co-benefits. They analyzed a policy that would assign a range of social costs to fossil fuel-based CO2 emissions. The policy would raise energy costs and increase the price of nitrogen fertilizer production.
The researchers then considered three different levels of social costs applied to the fossil fuel and found at the highest carbon price the cost of nitrogen fertilizer could rise by roughly 90%. This could lead to upwards of a 16% decline in fertilizer application for corn production across the Mississippi River Basin and a roughly 9% decline in fertilizer loss to the environment. Corn and soybean production would decline by about 7%, increasing crop prices by 6%, while nitrate leaching would decline by about 10%. Nitrates entering the environment are removed in various ways as they move through the watershed, so the decline in nitrogen leaving the watershed at the mouth of the Mississippi River was somewhat less (roughly a 9% reduction).
“Implementing a carbon price that reflects its social cost allows the U.S. to meet its commitment to the Paris Accord while significantly improving water quality,” said Tom Hertel, professor of agricultural economics at Purdue University and project principal investigator. “Our models showed that with this range of climate policies, U.S. carbon emissions could decline by 29% to 50%, depending on the stringency of the carbon pricing. This represents 4.6% to 8% of global carbon emissions and satisfies the range of reductions outlined in the Paris Accord.”
Researchers also considered the additional benefits of restored wetlands to mitigate nitrogen loading to reduce hypoxia in the Gulf of Mexico and found a targeted wetland restoration scenario approximately doubles the effect of a low to moderate social cost of carbon.
The team hopes these findings provide important context for policy makers to consider all aspects of climate mitigation, as well as for those that want to consider alternatives for reducing contamination to the Gulf of Mexico.
Co-authors include Wilfred Wollheim and Stephen Frolking, both from UNH; Jing Liu, Maksym Chepeliev, David Johnson, Uris Baldos and Tom Hertel, all from Purdue University; and Christopher Kucharik, from the University of Wisconsin-Madison.
Funding for this research was provided by the Innovations at the Nexus of Food, Energy and Water Systems project funded by the National Science Foundation. Partial funding was provided by the New Hampshire Agricultural Experiment Station through the USDA National Institute of Food and Agriculture
The University of New Hampshire inspires innovation and transforms lives in our state, nation and world. More than 16,000 students from 49 states and 82 countries engage with an award-winning faculty in top-ranked programs in business, engineering, law, health and human services, liberal arts and the sciences across more than 200 programs of study. A Carnegie Classification R1 institution, UNH partners with NASA, NOAA, NSF, and NIH, and received over $210 million in competitive external funding in FY23 to further explore and define the frontiers of land, sea and space.
###
JOURNAL
Proceedings of the National Academy of Sciences
LISTERIA
Pathogen that plagues food processing plants eradicated by blue light
Washington, D.C. – Blue light kills both dried cells and biofilms of the pathogen Listeria monocytogenes, a frequent contaminant of food processing facilities. Demise of L. monocytogenes occurred quickest when cells or biofilms were placed on polystyrene, a widely used, transparent form of plastic. The research is published in Applied and Environmental Microbiology, a journal of the American Society for Microbiology.
“These results contribute to advancing our understanding of the potential of blue light to treat inert surfaces contaminated with L. monocytogenes,” said corresponding author Francisco Diez-Gonzalez, Ph.D., Director and Professor, Center for Food Safety, University of Georgia. Although biofilms of pathogens are generally powerfully resistant to being exterminated, the results suggest that blue light could effectively destroy L. monocytogenes.
In the study, the investigators deposited liquid suspensions of mixtures of 5 strains of L. monocytogenes on small, sterile rectangular plates made of 6 different materials, including polystyrene, stainless steel and silicone rubber, which were then allowed to dry. The investigators also used similar plates to grow biofilms, which they also allowed to dry.
Then, they shined blue light onto the biofilms and onto the dried suspensions of cells on the plates to determine the most effective combinations of doses and wavelengths, as well as the most effective surfaces on which to extirpate the pathogens.
“The application of blue light for controlling microbial contamination has the potential to offer an additional technology that could complement existing methods for disinfecting surfaces in contact with foods,” said Diez-Gonzalez, noting that blue light has been used for disinfection in hospitals. As compared to ultraviolet light, blue light offers reduced risk for the user, he said.
A post-doc in Diez-Gonzalez’ laboratory, Fereidoun Forghani, Ph.D., kick-started the investigation when—searching for new ideas—he came across the use of blue light as a potential antimicrobial intervention to sanitize surfaces. Forghani built some blue light prototypes and produced the first preliminary results treating pure cultures of Listeria.
###
The American Society for Microbiology is one of the largest professional societies dedicated to the life sciences and is composed of 36,000 scientists and health practitioners. ASM's mission is to promote and advance the microbial sciences.
ASM advances the microbial sciences through conferences, publications, certifications, educational opportunities and advocacy efforts. It enhances laboratory capacity around the globe through training and resources. It provides a network for scientists in academia, industry and clinical settings. Additionally, ASM promotes a deeper understanding of the microbial sciences to diverse audiences.
JOURNAL
Applied and Environmental Microbiology
Public health interventions prevented transmission within BU most SARS-CoV-2 cases
Findings have implications for transmission protocols for other respiratory diseases
(Boston)— SARS-CoV-2, the causative agent of COVID-19, began impacting the U.S. in March 2020 with many schools and universities shifting to remote education by early April 2020 in response to the public health emergency. Despite public health interventions (increased ventilation, masking policies, surveillance testing, contact tracing of confirmed cases and quarantine procedures for infected students, faculty and staff) there were still concerns that institutes of higher education would be a hotbed of transmission, including transmission from students into surrounding communities.
But, were these fears warranted?
A new study from Boston University’s COVID Clinical Testing Lab and Contract Tracing along with researchers from Boston University Chobanian & Avedisian School of Medicine, has found that public health interventions prevented transmission for most SARS-CoV-2 introductions at BU, with only two major outbreaks within the university identified from January to May 2021.
“We found that genetically linked cases overlap with outbreaks identified by contact tracing; however, they persisted in the university population for fewer days and fewer rounds of transmission than originally estimated via contact tracing,” explains corresponding author John Connor, PhD, associate professor of microbiology at the School of Medicine. “This underscores the effectiveness of test-trace-isolate strategies in controlling undetected spread of emerging respiratory infectious diseases. These approaches limit transmission from those people outside the university as well as those who caught the disease from someone within the campus community,” adds Connor who also is a researcher at the Boston University National Emerging infectious Diseases Laboratories.
Connor and his team hypothesized that the viral genomics data would support contact tracing’s finding that most SARS-CoV-2 infection on campus were singular events not linked to intra-campus transmission chains. Additionally, they aimed to identify any large outbreaks among members of the campus community and align genetically identified outbreaks with cases linked via contact tracing.
In April 2020, Boston University enforced weekly surveillance testing, social distancing, masking and prohibited school-sanctioned social events. Individuals who tested positive were isolated for ten days by moving into on-campus isolation housing or isolating at private off-campus residences. To track and limit infection spread, the university performed comprehensive bi-directional contact tracing to identify likely transmission pathways through interviews of all test-positive individuals and known contacts. This information was then coupled with viral genomic sequencing for both asymptomatic and symptomatic cases to confirm likely transmission events and spur re-investigation if genomic data suggested additional links.
Viral genomic sequencing captured 767 unique SARS-CoV-2 genotypes on the BU campus during the spring 2021 semester. Of these, they observed 696 genotypes (91%) only once, making it unlikely that they established on-campus transmission chains. The few genotypes with multiple observations usually showed transmission bubbles of less than five individuals; only seven genotypes (approximately 1%) included more than five samples. According to the researchers, these findings highlight the ability of systematic testing, tracing, and quarantine approaches to limit respiratory transmission in a complicated urban environment with repeated introduction of SARS-CoV-2 from outside sources.
The researchers believe these findings have implications for not only SARS-CoV-2 but also other respiratory diseases and show what one can expect in future outbreaks if responses are limited and lack effective pharmacological interventions. Vaccination was unavailable to most BU students and staff until March 2021, so infection control measures were limited to mask mandates, symptom monitoring, surveillance testing, and isolation following a positive test. “Our analyses support the hypothesis that systematic interventions, such as population-level test-trace-isolate strategies, are highly effective in limiting respiratory infection transmission, even in the presence of continual importation of disease from outside the university population,” said first author Jackie Turcinovic, a PhD candidate in the Connor lab.
These findings appear online in the Journal of Infectious Diseases.
BU provided financial support for the testing program described in this study and supported sequencing efforts. The BUMC Genome Sciences Institute provided financial support for sequencing. JHC acknowledges funding from BU for SARS-CoV-2 surveillance, the Massachusetts Consortium on Pathogen Readiness (MassCPR), and the China Evergrande Group.
JOURNAL
The Journal of Infectious Diseases
METHOD OF RESEARCH
Data/statistical analysis
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Transmission dynamics and rare clustered transmission within an urban university population before widespread vaccination
ARTICLE PUBLICATION DATE
17-Oct-2023
International team reveals source of largest ever Mars quake
A global team of scientists have announced the results of an unprecedented collaboration to search for the source of the largest ever seismic event recorded on Mars. The study, led by the University of Oxford, rules out a meteorite impact, suggesting instead that the quake was the result of enormous tectonic forces within Mars’ crust.
The quake, which had a magnitude of 4.7 and caused vibrations to reverberate through the planet for at least six hours, was recorded by NASA’s InSight lander on May 4 2022. Because its seismic signal was similar to previous quakes known to be caused by meteoroid impacts, the team believed that this event (dubbed ‘S1222a’) might have been caused by an impact as well, and launched an international search for a fresh crater.
Although Mars is smaller than Earth, it has a similar land surface area because it has no oceans. In order to survey this huge amount of ground – 144 million km2 – study lead Dr Benjamin Fernando of the University of Oxford sought contributions from the European Space Agency, the Chinese National Space Agency, the Indian Space Research Organisation, and the United Arab Emirates Space Agency. This is thought to be the first time that all missions in orbit around Mars have collaborated on a single project. Each group examined data from their satellites orbiting Mars to look for a new crater, or any other tell-tale signature of an impact (e.g. a dust cloud appearing in the hours after the quake).
After several months of searching, the team announced today that no fresh crater was found. They conclude that the event was instead caused by the release of enormous tectonic forces within Mars’ interior. The results, published today in the journal Geophysical Research Letters, indicate that the planet is much more seismically active than previously thought.
Dr Fernando said: ‘We still think that Mars doesn’t have any active plate tectonics today, so this event was likely caused by the release of stress within Mars’ crust. These stresses are the result of billions of years of evolution; including the cooling and shrinking of different parts of the planet at different rates. We still do not fully understand why some parts of the planet seem to have higher stresses than others, but results like these help us to investigate further. One day, this information may help us to understand where it would be safe for humans to live on Mars and where you might want to avoid!’
He added: ‘This project represents a huge international effort to help solve the mystery of S1222a, and I am incredibly grateful to all the missions who contributed. I hope this project serves as a template for productive international collaborations in deep space.’
Dr Daniela Tirsch, Science Coordinator for the High Resolution Stereo Camera on board the European Space Agency’s Mars Express Spacecraft said: ‘This experiment shows how important it is to maintain a diverse set of instruments at Mars, and we are very glad to have played our part in completing the multi-instrumental and international approach of this study.’
From China, Dr Jianjun Liu (National Astronomical Observatories, Chinese Academy of Sciences) added: ‘We are willing to collaborate with scientists around the world to share and apply this scientific data to get more knowledge about Mars, and are proud to have provided data from the colour imagers on Tianwen-1 to contribute to this effort.’
Dr Dimitra Atri, Group Leader for Mars at New York University Abu Dhabi and contributor of data from the UAE’s Hope Spacecraft, said: ‘This has been a great opportunity for me to collaborate with the InSight team, as well as with individuals from other major missions dedicated to the study of Mars. This really is the golden age of Mars exploration!’
S1222a was one of the last events recorded by InSight before its end of mission was declared in December 2022. The team are now moving forward by applying knowledge from this study to future work, including upcoming missions to the Moon and Titan’s Moon Saturn.
The study ‘A tectonic origin for the largest marsquake observed by InSight’ will be published in Geophysical Research Letters at 14:01 BST/ 09:01 ET Tuesday 17 October 2023: https://doi.org/10.1029/2023GL103619. To view a copy of the study under embargo contact Dr Benjamin Fernando, Department of Physics, University of Oxford: benjamin.fernando@physics.ox.ac.uk
InSight was a NASA mission dedicated to the study of the martian interior through geophysics, especially seismology (the study of Earthqukes).
It launched from California in May 2018 and landed on Mars in November of that year. The last data were returned in December 2022, after the spacecraft lost power due to increasing dust accumulation on its solar panels.
External partners to the InSight mission included the UK, France, Germany, and Switzerland. Within the UK, Imperial College London and the University of Oxford are lead institutions.
During its time on Mars, InSight recorded over 1,300 marsquake events. Of these, at least 8 were from meteoroid impact events. The largest two formed craters around 150m in diameter. If the S1222a event was formed by an impact, we would expect the crater to be at least 300m in diameter.
This project involved all other active missions currently orbiting Mars, who contributed their data and expertise. These include:
The MAVEN, Mars Reconnaissance Orbiter (MRO), and Mars Odyssey spacecraft of NASA
The ExoMars Trace Gas Orbiter (TGO) and Mars Express (MEX) spacecraft of ESA
The Emirates Mars Mission (Hope) of the United Arab Emirates Space Agency
The Tianwen-1 Mission of the Chinese National Space Agency
The Mangalyaan (MOM) mission of the Indian Space Research Organisation, which ended in September 2022. The MOM data were searched but no relevant images were taken before the end of mission
Additional Quotes
Dr Ernst Hauber, lead of the geoscience working group for the High Resolution Stereo Camera on the Mars Express mission, added: ‘This shows how important mission extensions, like the ones that Mars Express has received in the last few years, are to maintaining a diverse set of instruments in orbit which are complementary to each other.’
Dr Constantinos Charalambous of Imperial College London, a co-author on the study, said: ‘The absence of a crater in our image search for S1222a marks a significant milestone in interpreting seismic signals on Mars, crucial for distinguishing impact events from tectonic forces on the Red Planet.’
About the University of Oxford
Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the eighth year running, and number 3 in the QS World Rankings 2024. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer.
Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions.
Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 300 new companies since 1988. Over a third of these companies have been created in the past five years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing £15.7 billion to the UK economy in 2018/19, and supports more than 28,000 full time jobs.
Humans and wildlife, including large carnivores, interact at an unprecedented scale as they increasingly share the world's landscapes.
A new University of Michigan-led study of human-lion interactions found that lions tend to avoid human-dominated areas unless they are facing food scarcity and habitat fragmentation.
The findings, published online Oct. 17 in the journal Communications Biology, suggest that expanding human land use, along with the effects of climate change, could increase the risk of human-lion conflict, which in turn threatens lion populations.
"Our study found that understanding the complex responses of wildlife to human disturbance—such as agricultural land or towns—is a key first step in fostering coexistence between humans and wildlife," said the study's lead author, Kirby Mills, a postdoctoral research fellow at U-M's Institute for Global Change Biology.
"In human-dominated landscapes, wildlife have to balance the tradeoffs between hunting prey and the potentially lethal risks of encountering humans. This is particularly true for large carnivores that often try to kill livestock, because threats to livestock can prompt retaliatory killing of large carnivores, which is a leading cause of large carnivore population declines around the world."
As almost half of the current range of lions lies outside of protected area boundaries, the carnivores are required to regularly navigate degraded human-dominated landscapes. Yet research addressing the tradeoffs the lions must make—between available prey and risks from humans—is rare, especially at very large spatial scales.
The international team of study authors aimed to contribute to a better understanding of lion responses to human disturbance by reviewing previously published data from 31 study sites spanning 40% of lion ranges worldwide. They found that at more than two-thirds of study sites, lions avoided areas of human activity or hunted primarily at night, particularly in locales dense with cattle ranches.
These behavioral adaptations, however, can impact entire ecosystems.
Neil Carter, associate professor at the School for Environment and Sustainability, and Nathan Sanders, professor and chair at the Department of Ecology and Evolutionary Biology, jointly supervised the study.
"Increasing nocturnal activity to avoid human encounters can influence competition between species, predator-prey dynamics and ecosystem function," Carter said. "Avoiding human-dominated areas altogether effectively limits the amount of habitat that lions can use and can increase competition, contribute to heightened risks of regional extinction, restructure wildlife community dynamics and, ultimately, reduce biodiversity."
The study also found that lions are more likely to forage in higher risk areas when seasonal vegetation cover—which predicts prey availability—or human presence is more variable, indicating that lions may be less likely to avoid humans when food is more limited or their habitats are more fragmented. Contributing to all these factors is the unpredictable effects of climate change.
"Climate change across Africa is projected to exacerbate resource stress for humans and wildlife alike, but the effects of climate change are too rarely emphasized in wildlife conservation," Sanders said. "Our findings reinforce what many others have called for, things like dedicating adequate funding and management capacity to protected areas where lions live, while engaging with and empowering local communities.
"Successful conservation of large carnivores depends on sustainable coexistence with empowered and supported local communities, especially as the planet gets ever warmer and resources become increasingly limited."
The First Step Act (FSA), signed into law in 2018, contributed significantly to reversing the incarceration frenzy that had characterized U.S. policy for decades. In a new book, Reform Nation: The First Step Act and the Movement to End Mass Incarceration, a scholar at William Paterson University investigates the national movement that coalesced in the law’s passage. In chronicling the inner workings that led to passage of the FSA, she explains that criminal justice reform had reached a crucial point of national political, economic, and cultural salience and ubiquity, giving it greater reach and mobilizing capacity than at any point in U.S. history.
“The FSA is less important than its exemplification of national-level movement dynamics and divisions,” notes the book’s author, Colleen P. Eren, associate professor of sociology and criminal justice at William Paterson University. “An account of its provisions—and where it fits in the history of federal criminal justice reform in the late 20th and early 21st centuries—provides critical contextual information for understanding deeper political and sociological questions.” Eren is an expert whose work is promoted by the Crime and Justice Research Alliance, which is funded by the National Criminal Justice Association.
The FSA is one of the major pieces of federal criminal justice legislation passed since mass incarceration began in the 1970s. At that time, the U.S. incarceration rate was around 200 per 100,000 adults, but would sharply rise until its peak of 1,000 per 100,000 adults between 2006 and 2008. The FSA, which authorized at $75 million per year for five years (or about $400 per incarcerated person), focused on reforms in corrections and sentencing.
The unlikely passage of the bill during a time of political polarization was attributed to the power of a new constellation of advocates, stakeholders, and alliances in the movement to end mass incarceration. Eren suggests that these intriguing and complex dynamics are indicative of a longer, 20-year shift in which the movement became nationalized and mainstreamed. Her book features firsthand accounts from inside the movement by a diverse array of stakeholders, including billionaire philanthropists, celebrities and influencers, corporations, formerly incarcerated people, and national advocates and activists.
In the run-up to the 2024 Presidential election, as calls to defund the police and rising crime rates are hotly debated, the details in Eren’s book raise important questions about how U.S. democratic processes inform criminal justice policy, how social change is enacted, and where the country is headed in the coming decades.
“The FSA’s symbolism and its function as a flashpoint for debate and for illuminating some of the contours and rifts of the reform movement made a fascinating departure point for investigating larger questions about the movement,” says Eren. These include:
How and when did criminal justice reform as a national movement emerge, and what spurred that emergence?
What issues were included and excluded under the broad “coalition” umbrella of individuals and groups who worked to pass the FSA?
Who were the stakeholders and who among them had a seat at the decision-making table?
What were the ideological differences within the movement, especially between “right” and “left,” and how were they negotiated?
How were decisions about movement objectives made?
What strategies and frames were used? Did the infusion of capital in its various forms help or hinder the movement? Was the movement driven from above or from below, and how durable was it?
“Looking forward, there is no reason to believe that efforts to reduce mass incarceration will regress significantly,” says Eren. “However, I also explore the characteristics of the national movement that can render it fragile, fractured, and of limited efficacy in making significant dents in mass incarceration. These considerations help in evaluating how to ensure the longevity and resilience of criminal justice reform despite changing headwinds.”
