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)
ITHACA, N.Y. -- The mysterious changes in phases of matter – from solid to liquid and back again – have fascinated Eun-Ah Kim since she was in lower elementary school in South Korea. Without cold drinking water readily available, on hot days the children would bring bottles of frozen water to school.
Kim noticed that when the water melted, the volume changed.
“That revealed to me there is something in there that I cannot see with my eyes,” said Kim, professor of physics in the College of Arts and Sciences. “Matter around me is made up of invisible entities that interact and do something together to change their state.”
Kim’s fascination with melting continues, but she now studies transitions in more exotic materials than water: electron crystals. In a new paper, Kim and first author Michael Matty, M.S. ’19, Ph.D. ’22, have described a phase in between the liquid and the solid for these electron structures – a liquid crystal state.
Because electrons are all negatively charged, they repel each other; thus their preferred state is to be as far as possible from every other electron in the material that contains them. The regular arrangement of electrons that results from this equal repulsion in all directions is called a Wigner crystal.
Kim and Matty wanted to know how the electrons transition from one regular arrangement as a crystal to another regular arrangement as a crystal, or how they “melt.”
To find the answer, the researchers studied how electrons interact on an artificial grid, called a moiré lattice, formed by placing two distinct atomically thin materials on top of each other. Because they are on a grid rather than a smooth surface, the electrons can’t choose arbitrary locations away from each other, but must fill a point on the grid; the grid constrains how they are arranged.
“When the grid is partially filled, we get to see the impact of their repulsion and how strongly the electrons are interacting with each other,” Kim said. “As a result of their interaction, we see that they occupy a regular interval of sites on the lattice, not random intervals.”
The particular moiré lattice the researchers considered for their study was developed by Cornell experimentalists Kin Fai Mak, professor of physics (A&S) and associate professor of physics in Cornell Engineering, and Jie Shan, professor of physics (A&S) and applied and engineering physics (Engineering).
“Cornell experimentalists are at the frontier of artificial moiré material research,” Kim said, “doing these amazing experiments with an astonishing degree of control, offering opportunities for theoretical ideas to manifest in physical systems.”
Shan and Mak had experimentally detected particular rigid structures that the electrons formed in partially filled grids. Kim and Matty studied how one of these structures would transition to another. They found that when conditions were changed, that very regular, rigid array becomes more fluid.
The researchers identified an intermediate phase between solid and liquid in electrons that has some regularity but not as much as a solid, and not as much freedom as a liquid. They found that the electrons in this state arrange themselves into tiny strips that can move around and orient themselves in structures.
“Electronic liquid crystals had been discussed theoretically, but we’re providing a visual image of how they can form microscopically: four or five electrons forming a piece that can be arranged,” said Kim. “What we’ve accomplished is a microscopic understanding of what was only known in principle to be possible.”
The work was supported by the National Science Foundation.
UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN, NEWS BUREAU
IMAGE: JIAHUI LI, LEFT, SHAN ZHOU AND PROFESSOR QIAN CHEN SHOW OFF AN ELECTRON MICROGRAPH IMAGE OF THEIR NEW PINWHEEL LATTICE STRUCTURE DEVELOPED TO HELP ENGINEERS BUILD NEW MATERIALS WITH UNIQUE OPTICAL, MAGNETIC, ELECTRONIC AND CATALYTIC PROPERTIES.view more
CREDIT: PHOTO BY FRED ZWICKY
CHAMPAIGN, Ill. —Researchers have developed a new strategy to help build materials with unique optical, magnetic, electronic and catalytic properties. These pinwheel-shaped structures self-assemble from nanoparticles and exhibit a characteristic called chirality – one of nature’s strategies to build complexity into structures at all scales, from molecules to galaxies.
Nature is rich with examples of chirality – DNA, organic molecules and even human hands. In general, chirality can be seen in objects that can have more than one spatial arrangement. For example, chirality in molecules might present itself as two strings of atoms that have the same composition, but each having a “twist” to the left or right in their spatial orientations, the researchers said.
The new study, led by Qian Chen, a professor of materials science and engineering at the University of Illinois Urbana-Champaign, and Nicholas A. Kotov, a professor chemical engineering at the University of Michigan, extends chirality into lattices assembled from nanoparticle building blocks to create new metamaterials – materials designed to interact with their surroundings to perform specific functions.
The study is published in the journal Nature.
Efforts to make large-scale chiral lattices from spontaneous assembly of nanoparticles have been met with limited success. Chen said previous studies relied on templates that produced very small structures, limiting their usefulness in metamaterials design.
“In the new study, we were inspired by the symmetry-breaking characteristics of porous materials to assemble reconfigurable lattices from pyramid-shaped nanoparticles smaller than 100 nanometers,” said former Illinois postdoctoral researcher Shan Zhou, the lead author of the work and currently a professor at South Dakota School of Mines and Technology. “The resulting lattice is large enough to be seen with the naked eye.”
Chen said previous models had not predicted a pinwheel lattice with chirality.
In this study, predictions based on graph theory and calculations developed by Kotov and Michigan postdoctoral researchers Ju Lu and Ji-Young Kim predicted – to their surprise – that the pinwheel lattice structure, although achiral in nature, becomes chiral on a substrate.
“The new lattice structure is fascinating from a research perspective, as it invites many new multifaceted study opportunities of their properties,” Kotov said.
Chen’s liquid-phase electron microscopy technique – which she says is akin to a “tiny aquarium for observing nanoparticle self-assembly” – was instrumental to this study.
Making this structure did not come by luck, though, the researchers said.
“The quantitative models turned out to be well-matched with the dynamic assembly process observed in the nanoaquarium of the liquid-phase electron microscope,” said Jiahui Li, an Illinois graduate student and co-author of the study.
“The liquid-phase electron microscopy allowed us to take the superlattice assembly even further,” Chen said.
“Because we can observe and manipulate the nanoparticle interactions in real time, we can precisely tune their motions to form the very intricate design of the pinwheel,” Li said.
In addition to liquid-phase electron microscopic techniques, the ultrafast electron microscope at the U.S. Department of Energy’s Argonne National Laboratory provided a unique understanding of the self-assembled superlattices’ optical properties at the nanometer scale.
“No one has been able to directly see the chiral responses of objects at such a small length using other techniques,” said Haihua Liu, a researcher at Argonne’s Center for Nanoscale Materials.
The team foresees this imaging platform being used to characterize a wide range of nanoparticles and self-assembled structures.
“As a theorist working in all things nanoparticle, I have always been interested in how to assemble nanoparticle arrangements that are chiral,” said Alex Travesset, a professor at Iowa State University who performed the geometric calculations for the pinwheel lattice. “The interesting behaviors of pinwheel lattice can go beyond their chiroptical responses.”
Kai Sun, a Michigan professor and study co-author, said the pinwheel lattices can reconfigure their structures, a property that is potentially useful in the design of combat helmets and airplanes, for example.
The researchers also envision using this new strategy to make other chiral metacoatings based on the existing library of synthetically available nanoparticles, and that it will enable a rich design space of metastructured surfaces with chiroptical activity and mechanical properties.
“We feel that this substrate-supported chiral assembly method can benefit the whole nanomaterials research community,” Kotov said.
The Office of Naval Research support this research through a Multidisciplinary University Research Initiative.
Editor’s notes:
To reach Qian Chen, call 217-300-1137; email qchen20@illinois.edu
The paper “Chiral assemblies of pinwheel superlattices on substrates” is available online and from the U. of I. News Bureau. DOI: 10.1038/s41586-022-05384-8.
COLUMBIA UNIVERSITY'S MAILMAN SCHOOL OF PUBLIC HEALTH
While some feared that New Yorkers would re-fill prescriptions to stockpile opioid medications in the early weeks of the COVID-19 lockdown much in the way people hoarded toilet paper, in fact, New York State opioid prescriptions declined in the period around the March 20, 2020 “PAUSE” order, according to new research. Meanwhile, prescriptions for medications for opioid use disorder (MOUD) were steady, likely thanks to policies to ensure their availability during the same period.
The study was led by researchers at Columbia University Mailman School of Public Health and appears in the journal Addiction, the journal of the Society for the Study of Addiction.
The researchers used a database from the health information technology and clinical research company IQVIA to examine trends in the dispensing of opioid prescriptions as New York State implemented various emergency policies to prevent the spread of COVID-19. These orders included pharmacy guidance permitting early refills of controlled and non-controlled medications (March 7); a suspension of elective surgeries in New York City (March 16); and a “New York State on PAUSE” order that greatly reduced trips outside the home (March 20). A concern with the recommendation for patients to refill their prescriptions early was that it would increase the quantities of opioids in households and increase the risk of opioid misuse and overdose. During the same period, the Substance Abuse and Mental Health Services Administration initiated a series of policy responses to support access to MOUD, such as expanding telemedicine and allowing online prescribing of buprenorphine.
They found that prescriptions for non-MOUD opioids steadily declined between the weeks of March 21 and April 17 with only a small transient increase in early refills. The morphine milligram equivalents/day (MME/day) prescribed were 17 percent lower than in the four weeks before March 21—almost entirely due to a drop in opioids dispensed for prescriptions of a week or less, suggesting the driving cause was the suspension of elective surgeries. (Another possible explanation is reduced demand for opioids related to a decline in accidents and injuries during the lockdown period.) There was no discernable drop in MOUD dispensing associated with the period of the Emergency Orders with only a slight increase in the count of dispensed prescriptions in the week of March 14. These trends were evident statewide, with no disparities between ZIP codes with higher or lower poverty rates.
The findings are in line with an earlier study that found the lockdown Texas similarly did not lead to a spike in prescriptions for non-MOUD opioids.
“Our findings add to the evidence showing that the pandemic emergency orders did not cause a mass surge in dispensing of opioids and policy initiatives to ensure access to medications for opioid use disorder were likely effective,” says Andrew Rundle, DrPH, professor of epidemiology at Columbia University Mailman School of Public Health. “The research suggests that critical access to treatments for opioid use disorder can be maintained during future emergency ‘stay at home’ type orders and such orders are unlikely to cause mass early refills of opioid prescriptions and heightened risk of misuse.”
The study’s first author is Abhinav Suri, who conducted the research as an MPH student in epidemiology at Columbia Mailman School and is now a medical student at the David Geffen School of Medicine, UCLA. Additional authors include Daniel J. Feaster and Raymond R. Balise, University of Miami Miller School of Medicine; Edward V. Nunes, Columbia University Irving Medical Center; Louisa Gilbert and Nabila El-Bassel, Columbia University School of Social Work.
This research was supported by the National Institutes of Health through the NIH HEAL Initiative (UM1DA049412). Access to IQVIA data was provided as part of the IQVIA Institute’s Human Data Science Research Collaborative in support of research activities related to important health system issues arising in the era of COVID-19.
Adding additional salt to foods at a lower frequency is associated with a reduced risk of heart disease, heart failure and ischemic heart disease, according to a new study published today in the Journal of the American College of Cardiology. Even among those following a DASH-style diet, behavioral interventions to lessen salt consumption could further improve heart health.
There’s substantial evidence linking high sodium intake to high blood pressure, a major risk factor for cardiovascular disease. However, epidemiological studies investigating this link have produced conflicting results due to a lack of practical methods for assessing long-term dietary sodium intake. Recent studies suggest that the frequency at which an individual adds salt to their foods could be used to predict their individual sodium intake over time.
“Overall, we found that people who don’t shake on a little additional salt to their foods very often had a much lower risk of heart disease events, regardless of lifestyle factors and pre-existing disease,” said Lu Qi, MD, PhD, HCA Regents Distinguished Chair and professor at the School of Public Health and Tropical Medicine at Tulane University in New Orleans. “We also found that when patients combine a DASH diet with a low frequency of adding salt, they had the lowest heart disease risk. This is meaningful as reducing additional salt to food, not removing salt entirely, is an incredibly modifiable risk factor that we can hopefully encourage our patients to make without much sacrifice.”
In the current study, the authors evaluated whether the frequency of adding salt to foods was linked with incident heart disease risk in 176,570 participants from the UK Biobank. The study also examined the association between the frequency of adding salt to foods and the DASH diet as it relates to heart disease risk.
The study used a questionnaire at baseline to collect data on the frequency of adding salt to foods, not including salt used in cooking. Participants were also asked if they had made any major changes to their diet in the last 5 years, as well as complete 1-5 rounds of 24-hour dietary recalls over a three-year period.
The DASH-style diet was developed to prevent hypertension by limiting consumption of red and processed meats and focusing on vegetables, fruit, whole grains, low-fat dairy, nuts, and legumes. While the DASH diet has yielded benefits in relation to reducing cardiovascular disease risk, a recent clinical trial found that combining the DASH diet with sodium reduction was more beneficial for certain cardiac biomarkers, including cardiac injury, strain, and inflammation. The researchers calculated a modified DASH score that did not consider sodium intake based on seven foods and nutrients that were emphasized or deemphasized in the DASH-style diet.
Data on heart disease events was collected through medical history and data on hospital admissions, questionnaire and death register data.
Overall, study participants with a lower frequency of adding salt to foods were more likely to be women; white; have a lower body mass index; more likely to have moderate alcohol consumption; less likely to be current smokers; and more physically active. They also had a higher prevalence of high blood pressure and chronic kidney disease, but a lower prevalence of cancer. These participants were also more likely to adhere to a DASH-style diet and consumed more fruits, vegetables, nuts and legumes, whole grains, low-fat dietary but less sugar-sweetened drinks or red/processed meats than those with a higher frequency of adding salt to foods.
The researchers found the association of adding salt to foods with heart disease risk was stronger in participants of lower socioeconomic status, as well as in current smokers. A higher modified DASH diet score was associated with lower risk of heart disease events.
In a related editorial comment, Sara Ghoneim, MD, a gastroenterology fellow at the University of Nebraska Medical Center, wrote that the study is promising, builds on previous reports, and alludes to the potential impact of long-term salt preferences on total cardiovascular risk.
“A major limitation of the study is the self-reported frequency of adding salt to foods and the enrollment of participants only from the UK, limiting generalizability to other populations with different eating behaviors,” Ghoneim said. “The findings of the present study are encouraging and are poised to expand our understanding of salt-related behavioral interventions on cardiovascular health.”
The American College of Cardiology envisions a world where innovation and knowledge optimize cardiovascular care and outcomes. As the professional home for the entire cardiovascular care team, the mission of the College and its more than 56,000 members is to transform cardiovascular care and to improve heart health. The ACC bestows credentials upon cardiovascular professionals who meet stringent qualifications and leads in the formation of health policy, standards and guidelines. The College also provides professional medical education, disseminates cardiovascular research through its world-renowned JACC Journals, operates national registries to measure and improve care, and offers cardiovascular accreditation to hospitals and institutions. For more, visit acc.org.
The ACC’s family of JACC Journals rank among the top cardiovascular journals in the world for scientific impact. The flagship journal, the Journal of the American College of Cardiology (JACC) — and family of specialty journals consisting of JACC: Advances, JACC: Asia, JACC: Basic to Translational Science, JACC: CardioOncology, JACC: Cardiovascular Imaging, JACC: Cardiovascular Interventions, JACC: Case Reports, JACC: Clinical Electrophysiology and JACC: Heart Failure — pride themselves on publishing the top peer-reviewed research on all aspects of cardiovascular disease. Learn more at JACC.org.
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JOURNAL
Journal of the American College of Cardiology
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The swimming habits of gelatinous animals are inspiring underwater vehicle design
IMAGE: PHYSONECT SIPHONOPHORES, MARINE ANIMALS RELATED TO JELLYFISH, SWIM VIA JET PROPULSION.view more
CREDIT: PLEASE CREDIT THE SUTHERLAND LAB.
A gelatinous sea creature could teach engineers a lesson or two.
Nanomia bijuga, a marine animal related to jellyfish, swims via jet propulsion. A dozen or more squishy structures on its body pump water backwards to push the animal forward. And it can control these jets individually, either syncing them up or pulsing them in sequence.
These two different swimming styles let the animal prioritize speed or energy efficiency, depending on its current needs, a team of University of Oregon researchers found. The discovery could inform underwater vehicle design, helping scientists to build more robust vehicles that can perform well under a variety of conditions.
The UO team, led by marine biologist Kelly Sutherland and postdoctoral researcher Kevin Du Clos, report their findings in a paper publishing November 28 in Proceedings of the National Academy of Sciences.
“Most animals can either move quickly or in a way that’s energetically efficient, but not both,” said Sutherland. “Having many, distributed propulsion units allows Nanomia to be both fast and efficient. And, remarkably, they do this without having a centralized nervous system to control the different behaviors.”
Nanomia shares the gelatinous, ethereal form of its jellyfish relatives. But it’s a little more structurally complicated: Each one is technically a colony of individuals. For instance, each of Nanomia’s jets is produced by an individual unit called a nectophore. The nectophores are clustered on a stalk-like structure at the front of the animal. Meanwhile, wispy tentacles trail behind, carrying structures specialized for feeding, reproduction, and protection.
While many marine creatures move via jet propulsion, squid and jellyfish included, most just have one jet. Nanomia often has ten to twenty—the exact number varies colony-to-colony.
“We're interested in why multi-jet swimming is useful, and what we were really interested in here was the timing,” Du Clos said. Nanomia can pulse its nectophores all at once, or activate them in a sequence. Du Clos and his colleagues wanted to see how those different modes impacted the animals’ swimming style, possibly illuminating an evolutionary advantage to having multiple jets.
At Friday Harbor Labs in Washington, the researchers scooped Nanomia out of the ocean and put them in tanks in the lab. Then, they used video recordings and computer models to analyze the swimming patterns.
The two different swimming modes are suited to different situations, the team found.
Synchronous pulsing sends Nanomia forward very quickly—perfect for an expeditious escape from a predator. Asynchronous pulsing moves the animal a little more slowly, but more steadily, and the researchers’ modeling experiments suggested that it’s a more energy-efficient way to swim. So with Nanomia sometimes traveling hundreds of meters per day, asynchronous pumping might be better suited for everyday use.
The intricacies of Nanomia’s movement could be useful for engineers turning to nature for inspiration.
“It gives a framework for developing a robot that has a range of capabilities,” Du Clos said. For instance, an underwater vehicle could have multiple propulsors, and simple changes in propulsion timing could allow that one vehicle to move either quickly or efficiently as the need arises.
In future work, the researchers plan to dive more into Nanomia’s features, next focusing on better understanding how the arrangement of the animal’s tentacles affects its feeding.
Colonial animals are quite common in the open sea due to their potential hydrodynamic advantages, Sutherland added. The team is currently looking beyond Nanomia at other species of colonial swimmers, to figure out how diverse arrangements of swimming units influence animals’ movement.
Distributed propulsion enables fast and efficient swimming modes in physonect siphonophores
California Academy of Sciences researchers reveal how extinct Steller’s sea cow shaped kelp forests
To uncover “sea cow effect,” researchers developed new Past-Present-Future modeling approach that could inform more effective conservation strategies across ecosystems
IMAGE: A DRAWING OF A STELLER'S SEA COW, AN EXTINCT MARINE MEGAHERBIVORE. (BIODIVERSITY HERITAGE LIBRARY, CC BY 2.0, VIA WIKIMEDIA COMMONS)view more
CREDIT: BIODIVERSITY HERITAGE LIBRARY, CC BY 2.0, VIA WIKIMEDIA COMMONS
SAN FRANCISCO, CA (November 28, 2022) — For millions of years, the Steller’s sea cow, a four-ton marine mammal and relative of the manatee, shaped kelp forests along the Pacific coast of North America by eating massive quantities of kelp fronds from the upper canopies, thus allowing light to spur productivity in the understory. In a paper published today in Frontiers in Ecology and Evolution, researchers from the California Academy of Sciences—as part of the Academy’s Thriving Californiainitiative—reveal what historical kelp forests may have looked like in the presence of the marine megaherbivore, which went extinct in the 1700s just 27 years after its first encounter with Europeans due to overhunting, and suggest how kelp forest conservation efforts can take its absence into account.
“Kelp forests are highly productive ecosystems. They act as storm buffers, are economically important for fishing, and are home to countless marine organisms, yet they are in steep decline throughout the Pacific,” says study author and Academy Curator of Geology and Invertebrate Zoology Peter Roopnarine, PhD. “When kelp forests were evolving millions of years ago, there were large marine herbivores like the Steller’s sea cow, which are now extinct. So when it comes to what’s driving their widespread decline, there might be a major component we’re missing.”
This tendency to evaluate the state of modern ecosystems based on their recent past is known as shifting baseline syndrome and can obscure how an ecosystem may have existed over much longer periods of time.
“We already see the consequences of this thinking with things like wildfire management,” Roopnarine says. “In the short-term, wildfires have been seen as something to suppress because of the damage they bring to forest ecosystems. But recently we have learned that, in the long run, wildfires are a natural part of those systems that can lead to healthier, more resilient forests.”
A new approach to address shifting baselines
In the paper, the researchers propose—and advocate for—a new way of evaluating the overall health of ecosystems to avoid the pitfalls of shifting baseline syndrome, called the Past-Present-Future (PPF) approach.
As opposed to evaluating an ecosystem based on its current state, the researchers say the PPF approach, which combines historical lines of evidence from museum specimens and the fossil record with Indigenous traditional ecological knowledge and modern scientific data, can lead to mathematical models that more accurately depict natural systems. Importantly, these models can then be operationalized for more effective conservation.
"Today, we are surrounded by severely degraded ecosystems, places that were far healthier a mere century ago, let alone a millennium or more,” says study author and Academy Executive Director Scott Sampson, PhD. “Growing numbers of these ecosystems are now in danger of collapse, even if we protect them. So if we are to help guide a given place toward a flourishing future, we must understand not only its current state of health, but past states as well, and then apply these insights toward calculated, regenerative interventions. This Past-Present-Future approach to conservation has the potential to be revolutionary."
Uncovering the “sea cow effect”
To get a better picture of kelp forests of the past—and therefore a better baseline from which to compare against the state they are in today and predict how they might change in the future—the researchers built a mathematical model using historical and modern data to simulate how the ecosystem might respond under different scenarios.
First, the researchers input the effects different players in the ecosystem have on kelp forests, such as predation of kelp by sea urchins or predation of urchins by sea otters. The model was then compared against pre-existing data on kelp forests to ensure it reproduced how the ecosystems function in real life.
Once the researchers refined the model, they were then able to explore how the Steller’s sea cow impacts kelp forests by adding them to the model and seeing how the ecosystem responded over time.
“One of the more important and surprising findings was that including the Steller’s sea cow resulted in a totally different type of kelp forest,” says study author and postdoctoral researcher at the Academy and the University of Nevada Las Vegas Roxanne Banker, PhD. “Instead of kelp-dominated, which is what we think of with modern forests, the sea cow’s presence and predation of the upper canopy would have resulted in more of a balance between kelp and algae as more sunlight would have reached the sea floor.”
Banker adds that this finding is of particular significance when reflecting on the current state of kelp forests, which are heavily degraded due in part to overpredation from sea urchins. “Algae would provide an additional food source for urchins, potentially reducing their impact on kelp,” she says.
The study also showed that when the sea cow was present, the kelp forests as a whole were often more resilient: Even under adverse conditions, such as ocean warming or disease outbreaks, kelp forests may have been less likely to transition to the barren urchin-dominated state that is often seen today, and when they did they more quickly recovered to a forested state. This effect, which the researchers dubbed the “sea cow effect,” provides actionable insights for current kelp conservation efforts.
“If our model was further validated through experimentation on test plots, it could allow us to build more resilience into kelp forests by modeling the efficacy of different interventions,” Roopnarine says. “Selectively harvesting the upper fronds of the kelp canopy, for instance, to recreate the role that was lost with the Steller’s sea cow.”
Media Contact: Skylar Knight, sknight@calacademy.org Interviews with researchers available upon request.
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About the California Academy of Sciences The California Academy of Sciences is a renowned scientific and educational institution with a mission to regenerate the natural world through science, learning, and collaboration. Based in San Francisco’s Golden Gate Park, it is home to a world-class aquarium, planetarium, and natural history museum, as well as innovative programs in scientific research and environmental education—all under one living roof. Museum hours are 9:30 am – 5:00 pm Monday – Saturday, and 11:00 am – 5:00 pm on Sunday. Admission includes all exhibits, programs, and shows. For daily ticket prices, please visit www.calacademy.org or call (415) 379-8000 for more information.
About Research at the California Academy of Sciences The Institute for Biodiversity Science and Sustainability at the California Academy of Sciences is at the forefront of efforts to regenerate the natural world through science, learning, and collaboration. Based in San Francisco, the Institute is home to more than 100 world-class scientists, state-of-the-art facilities, and nearly 46 million scientific specimens from around the world. The Institute also leverages the expertise and efforts of more than 100 international Associates and 450 distinguished Fellows. Through expeditions around the globe, investigations in the lab, and analysis of vast biological datasets, the Institute’s scientists work to understand the evolution and interconnectedness of organisms and ecosystems, the threats they face around the world, and the most effective strategies for ensuring they thrive into the future. Through deeply collaborative partnerships and innovative public engagement initiatives, they also guide critical conservation decisions worldwide, inspire and mentor the next generation of scientists, and foster responsible stewardship of our planet.
In cannabis trials against pain, people who take placebos report feeling largely the same level of pain relief as those who consume the active cannabinoid substance. Still, these studies receive significant media coverage regardless of the clinical outcome, report researchers from Karolinska Institutet in Sweden in a study published in JAMA Network Open.
“We see that cannabis studies are often described in positive terms in the media regardless of their results,” says the study’s first author Filip Gedin, postdoc researcher at the Department of Clinical Neuroscience, Karolinska Institutet. “This is problematic and can influence expectations when it comes to the effects of cannabis therapy on pain. The greater the benefit a treatment is assumed to have, the more potential harms can be tolerated.”
The study is based on an analysis of published clinical studies in which cannabis has been compared with placebo for the treatment of clinical pain. The change in pain intensity before and after treatment were the study’s primary outcome measurement.
The analysis drew on 20 studies published up to September 2021 involving almost 1,500 individuals.
The results of the study show that pain is rated as being significantly less intense after treatment with placebo, with a moderate to large effect. The researchers also observed no difference in pain reduction between cannabis and placebo, which corroborates results from another recently published meta-analysis.
“There is a distinct and clinically relevant placebo response in studies of cannabis for pain,” says Dr Gedin.
The researchers also examined a possible connection between the magnitude of the therapeutic effect shown by the cannabis studies and the coverage they receive in the media and in academic journals. Media presence was measured through Altmetric, which is a method of evaluating mentions in the media, in blogs and on social media. Academic impact was measured in terms of citations by other researchers.
The analysis of media presence included a total of 136 news items in traditional media and in blogs and was categorised as positive, negative or neutral, depending on how the results were presented concerning the effectiveness of cannabis as a treatment for pain.
The researchers found that the cannabis studies received much greater media attention than other published studies. The coverage was substantial regardless of the magnitude of the placebo response and regardless of the therapeutic effect of cannabis. They also observed no link between the proportion of positively described news about a study and the effect it reported.
The researchers add the caveat that their study combined trials of varying designs and quality and therefore the results should be interpreted with caution.
This research was financed by Riksbankens Jubileumsfond (Karin Jensen). The researchers report no potential conflicts of interest.
Publication: “Placebo Response and media attention in randomized clinical trials assessing cannabis-based therapies for pain: A systematic review and meta-analysis”, Filip Gedin, Sebastian Blomé, Moa Ponten, Maria Lalouni, Jens Fust, Andreé Raquette, Viktor Vadenmark Lundquist, William H. Thompson and Karin Jensen, JAMA Network Open, online 28 November, 2022, doi:10.1001/jamanetworkopen.2022.43848
“Placebo Response and media attention in randomized clinical trials assessing cannabis-based therapies for pain: A systematic review and meta-analysis”
Biodiversity in Africa and Latin America at risk from oil palm expansion, new report warns
Zero deforestation commitments may inadvertently leave vital habitats in Latin America and Africa vulnerable to agricultural expansion, a new study has found.
The study highlights how sustainability commitments, which play an important role in preventing the destruction of tropical rainforest, fail to protect nature in tropical grassy and dry forest habitats such as the Llanos in Colombia, Beni savanna in northern Bolivia, and Guinean and Congolian savannas in West and Central Africa.
The research team, led by the University of York, calculated that if oil palm producers cleared these habitats to make way for new plantations, a third of vertebrates on the International Union for Conservation of Nature’s red list of threatened species could be affected, including the blue-throated macaw in Bolivia, the giant pangolin in Congo, and the Hellmich's Rocket Frog in Colombia.
For the study, researchers mapped the areas around the globe that are at risk from new oil palm plantations. They identified 167 million hectares that are potentially suitable for the crop while still meeting the Roundtable on Sustainable Palm Oil’s (RSPO) definition of 'zero deforestation'. Of those 167 million hectares, 95 million are in grasslands and dry forests, mostly in South America and Africa.
As global demand for agricultural land increases researchers are calling for urgent protections for these habitats, which support a rich array of species and act as an important carbon store.
Co-author of the study, Professor Jane Hill from the Department of Biology and the Leverhulme Centre for Anthropocene Biodiversity at the University of York, said: “Palm oil is at the sharp edge of debate on how we can balance the need to feed the world and sustain livelihoods, while protecting nature.
“With a yield estimated to be six times higher than many other vegetable oils such as oil seed rape, palm oil is regarded as a miracle crop and it supports the livelihoods of millions of people in tropical countries around the world. So rather than avoiding or banning palm oil, we need to ensure effective international policies and governance to protect, not just tropical rainforest, but tropical grasslands and dry forests too.
“Our study highlights how current sustainability commitments could have the unintended consequence of putting areas of remarkable biodiversity at risk from the expansion of oil palm agriculture.”
Since 2018, many oil palm companies have signed up to the RSPO’s zero deforestation commitments, which means they cannot expand plantations into tropical rainforest or peatlands.
While concern from buyers and consumers about the environmental impact of palm oil has helped to drive membership of the scheme, many oil palm producers are yet to sign up to these commitments.
First author, Dr Susannah Fleiss, who carried out the study while researching her PhD at the University of York, said: “Although we found that oil palm yield in areas currently covered by grassland and dry forest would be lower than in tropical rainforest, these sites would still be attractive for the expansion of oil palm agriculture. We also found that irrigation would improve yield in many of these locations, potentially making them more attractive for expansion.
“Clearing these areas for plantations would have a serious impact on biodiversity, potentially reducing the ranges of one quarter of vertebrate species that are currently threatened with extinction. Plantation development would replace the existing habitat in these areas, disrupting the ability of the species present to find food and water, and affecting their migration routes.
“Large numbers of people live in tropical grassy and dry forest regions, where they often play a critical role in ecological processes such as burning and grazing. The expansion of oil palm agriculture in these areas could lead to a number of interlinked issues for local people and biodiversity.
“Our study highlights the strong need for internationally-coordinated governance to protect these habitats, in addition to the existing global efforts to protect tropical rainforest.”
Co-author Dr Phil Platts, Honorary Fellow at the University of York and Director of Earth Observation at BeZero Carbon, said: “Sustainability guidelines for palm oil were developed in the context of Southeast Asia’s rainforests, and so reflect the structure and function of those habitats. Now expansion is shifting to different ecological contexts, the scope of sustainability commitments must similarly expand, in line with the distinct biodiversity and carbon stocks now under threat.”
The research, published in the journal Nature Ecology and Evolution, is funded by Unilever, in collaboration with the University of Liverpool, Oxford, the Potsdam Institute for Climate Impact Research, Unilever and BeZero Carbon.
JOURNAL
Nature Ecology & Evolution
Ethiopian schools study suggests COVID has “ruptured” social skills of the world’s poorest children
Primary school pupils were less confident talking to others and found it harder to make friends after the pandemic. Two interlinked studies, involving 8,000 primary pupils altogether, indicate children lost at least a third of a year in learning.
School closures during the COVID-19 pandemic have “severely ruptured” the social and emotional development of some of the world’s poorest children, as well as their academic progress, new evidence shows.
In a study of over 2,000 primary school pupils in Ethiopia, researchers found that key aspects of children’s social and emotional development, such as their ability to make friends, not only stalled during the school closures, but probably deteriorated.
Children who, prior to the pandemic, felt confident talking to others or got on well with peers were less likely to do so by 2021. Those who were already disadvantaged educationally – girls, the very poorest, and those from rural areas – seem to have been particularly badly affected.
Both this research and a second, linked study of around 6,000 grade 1 and 4 primary school children, also found evidence of slowed academic progress. Children lost the equivalent of at least one third of an academic year in learning during lockdown – an estimate researchers describe as “conservative”. This appears to have widened an already significant attainment gap between disadvantaged pupils and the rest, and there is some evidence that this may be linked to the drop in social skills.
Both studies were by academics from the University of Cambridge, UK and Addis Ababa University, Ethiopia.
Professor Pauline Rose, Director of the Research in Equitable Access and Learning (REAL) Centre at the Faculty of Education, University of Cambridge, said: “COVID is having a long-term impact on children everywhere, but especially in lower-income countries. Education aid and government funding must focus on supporting both the academic and socio-emotional recovery of the most disadvantaged children first.”
Professor Tassew Woldehanna, President of Addis Ababa University, said: “These severe ruptures to children’s developmental and learning trajectories underline how much we need to think about the impact on social, and not just academic skills. Catch-up education must address the two together.”
Both studies used data from the Research on Improving Systems of Education (RISE) programme in Ethiopia to compare primary education before the pandemic, in the academic year 2018/19, with the situation in 2020/21.
In the first study, researchers compared the numeracy test scores of 2,700 Grade 4 pupils in June 2019 with their scores shortly after they returned to school, in January 2021. They also measured dropout rates. In addition, pupils completed the Children’s Self Report Social Skills scale, which asked how much they agreed or disagreed with statements such as “I feel confident talking to others”, “I make friends easily”, and “If I hurt someone, I say sorry”.
The second study measured relative progress during the pandemic using the numeracy scores of two separate cohorts of Grade 1 and Grade 4 pupils. The first of these cohorts was from the pre-pandemic year; the other from 2020/21.
The results suggest pupils made some academic progress during the closures, but at a slower than expected rate. The average foundational numeracy score of Grade 1 pupils in 2020/21 was 15 points behind the 2018/19 cohort; by the end of the year that gap had widened to 19 points. Similarly, Grade 4 students started 2020/21 10 points behind their predecessor cohort, and were 12 points adrift by the end. That difference amounted to roughly one third of a year’s progress. Similar patterns emerged from the study of children’s numeracy scores before and after the closures.
Poorer children, and those from rural backgrounds, consistently performed worse academically. Dropout rates revealed similar issues: of the 2,700 children assessed in 2019 and 2021, more than one in 10 (11.3%) dropped out of school during the closures. These were disproportionately girls, or lower-achieving pupils, who tended to be from less wealthy or rural families.
All pupils’ social skills declined during the closure period, regardless of gender or location. Fewer children agreed in 2021 with statements such as “Other people like me” or “I make friends easily”. The decline in positive responses differed by demographic, and was sharpest among those from rural settings. This may be because children from remote parts of the country experienced greater isolation during lockdown.
The most striking evidence of a rupture in socio-emotional development was the lack of a predictive association between the 2019 and 2021 results. Pupils who felt confident talking to others before the pandemic, for example, had often changed their minds two years later.
Researchers suggest that the negative impact on social and emotional development may be linked to the slowdown in academic attainment. Children who did better academically in 2021 tended to report stronger social skills. This association is not necessarily causal, but there is evidence that academic attainment improves children’s self-confidence and esteem, and that prosocial behaviours positively influence academic outcomes. It is therefore possible that during the school closures this potential reinforcement was reversed.
Both reports echo previous research which suggests that lower-income countries such as Ethiopia need to invest in targeted programmes for girls, those from rural backgrounds, and the very poorest, if they are to prevent these children from being left behind. Alongside in-school catch-up programmes, action may be required to support those who are out of school. Ghana’s successful Complementary Basic Education initiative provides one model.
In addition, the researchers urge education policy actors to integrate support for social skills into both catch-up education and planning for future closures. “Social and emotional skills should be an explicit goal of the curriculum and other guidance,” Rose said. “Schools may also want to think about after-school clubs, safe spaces for girls, and ensuring that primary-age children stay with the same group of friends during the day. Initiatives like these will go some way towards rebuilding the prosocial skills the pandemic has eroded.”
Ruptured School Trajectories is published in the journal, Longitudinal and Life Course Studies. Learning Losses during the COVID-19 Pandemic in Ethiopia, is available on the REAL Centre website.
JOURNAL
Longitudinal and Life Course Studies
ARTICLE TITLE
Ruptured school trajectories: Understanding the impact of COVID-19 on school dropout, socio-emotional and academic learning using a longitudinal design
