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)
Wednesday, October 09, 2024
Scientists caution no guarantees when it comes to overshooting 1.5°C
International Institute for Applied Systems Analysis
Even if it is possible to reverse the rise of global temperatures after a temporary overshoot of 1.5°C, some climate damages inflicted at peak warming, including rising sea levels, will be irreversible, according to a new study published today in Nature.
The study is the culmination of a three-and-a-half-year project, backed by the European innovation fund HORIZON2020, looking at so-called ‘overshoot’ scenarios where temperatures temporarily exceed the Paris Agreement’s 1.5°C limit, before descending again by achieving net-negative CO2 emissions.
“This paper does away with any notion that overshoot would deliver a similar climate outcome to a future in which we had done more, earlier, to ensure to limit peak warming to 1.5°C,” explains Carl-Friedrich Schleussner, Integrated Climate Impacts Research Group Leader in the IIASA Energy, Climate, and Environment Program and scientific advisor at Climate Analytics, who led the study. “Only by doing much more in this critical decade to bring emissions down and peak temperatures as low as possible, can we effectively limit damages,” he adds.
It matters how high and for how long we let temperatures rise
The paper highlights that if we were to exceed 1.5°C there are clear benefits to reversing warming by acting to achieve net negative emissions globally. Achieving long-term temperature decline could lower sea level rise in 2300 by about 40 cm compared to a situation in which temperatures merely stopped rising.
“Until we get to net zero, warming will continue. The earlier we can get to net zero, the lower peak warming will be, and the smaller the risks of irreversible impacts,” notes study co-author Joeri Rogelj, professor of climate science and policy and Director of Research of the Grantham Institute at Imperial College London and senior research scholar in the IIASA Energy, Climate, and Environment Program. “This underscores the importance of countries submitting ambitious new reduction pledges, or so-called Nationally Determined Contributions (NDCs), well ahead of next year’s climate summit in Brazil.”
Full carbon dioxide removal capacity needed to hedge against higher warming
The study emphasizes that while there are still pathways open to limiting warming to 1.5°C or lower in the long run, there is a need to ‘hedge’ against higher warming outcomes if the climate system warms more than median estimates. To do this, ambitious emissions reductions need to go hand in hand with scaled and environmentally sustainable carbon dioxide removal technologies. A ‘preventive capacity’ of several hundred gigatons of net removals might be required.
“There’s no way to rule out the need for large amounts of net negative emissions capabilities, so we really need to minimize our residual emissions. We cannot squander carbon dioxide removal on offsetting emissions we have the ability to avoid,” commented study coauthor Gaurav Ganti, research assistant at IIASA and a research analyst at Climate Analytics.
“Our work reinforces the urgency of governments acting to reduce our emissions now, and not later down the line. The race to net zero needs to be seen for what it is – a sprint,” Schleussner concludes.
About IIASA: The International Institute for Applied Systems Analysis (IIASA) is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policymakers to shape the future of our changing world. IIASA is independent and funded by prestigious research funding agencies in Africa, the Americas, Asia, and Europe. www.iiasa.ac.at
WashU archaeologists are investigating coastal and underwater caves in southeastern Sicily, tracing early human dispersal onto the island. (Photo: Ilaria Patania)
Archaeological surveys led by scientists at Washington University in St. Louis suggest that coastal and underwater cave sites in southern Sicily contain important new clues about the path and fate of early human migrants to the island.
A new study in PLOS ONE reports and assesses the contents of 25 caves and rock shelters, most of them first identified between 1870 and the 1990s but essentially lost to science over time. Study authors also conducted new land and underwater surveys in previously unexplored coastal areas and uncovered three new sites that contain potentially important archaeological sediments.
“What we are looking for is not just the first person who arrived, but the first community,” said Ilaria Patania, an assistant professor of archaeology in Arts & Sciences. “Understanding the timing of the initial colonization of Sicily provides key data for the pattern and mode of the early expansion of Homo sapiens into the Mediterranean.”
Sicily is considered by many scholars to be the earliest island in the region to be permanently occupied by human ancestors, but when and how the early migrants accomplished this feat remains unknown. Sicily is less than two miles from mainland Italy, but the water crossing would have been extremely difficult for early humans.
Other studies have primarily focused on possible entry points on the island’s northern side.
“This research shows that new ways of thinking and looking can reveal patterns that weren’t visible before,” said T.R. Kidder, the Edward S. and Tedi Macias Professor of anthropology in Arts & Sciences at WashU, a co-author of the new study.
“Previous scholars assumed that sites on the southern coast of Sicily would be eroded or too damaged to yield useful information,” Kidder said. “But finding underwater sites opens up a whole new terrain to study. It allows us to reconsider routes of migration of these earliest modern human ancestors.”
Dangerous water crossing
Sicily, the largest Mediterranean island, is located just off the “toe” of Italy’s boot.
In the ancient Greek poem the “Odyssey,” Homer describes how Odysseus sailed his ship past the mythical sea monsters Scylla and Charybdis as he crossed the Sicily strait. The strait was well known to sailors of the past; they attributed the deadly forces of its waves and whirlpools to powerful monsters.
In modern times, thousands of migrants from North Africa attempt to cross the strait each year. Many don’t make it, some capsizing just a few hundred meters from landing.
Patania, a native of the island of Sicily, has a deep respect for the power of the sea. Her grandfather was a fisherman who worked on the same shores she now studies.
“Very early on, I was taught that the sea can be a great resource,” she said. “At the same time, you never turn your back on the sea. The sea can be very dangerous.”
This idea plays out in her research. “I’m very interested in how humans occupy marginal environments,” Patania said. “These are environments where if everything goes well, we are in perfect harmony with nature. But if something changes — and this could be something like global climate change, or something smaller, like the arrival of a new animal — it could be a catastrophe.”
Scholars of the region agree that humans had made it to Sicily by 16,000 years after the last glacial maximum. But that established date is puzzlingly late, given that humans are known to have dispersed by land into Siberia about 30,000 years earlier. The discrepancy has led some to wonder if humans actually arrived on Sicily much before the currently accepted dates.
Also, no one yet knows whether humans arrived on Sicily by seafaring, or by foot over a land bridge — or even what direction they came from.
“A challenge for understanding the spread of early modern human ancestors is that we don’t fully understand how they spread and colonized the world at a very early stage,” Kidder said. “As Ilaria says, this is a very marginal environment. Did folks come down from Italy and cross the Straits of Messina, or did they come from the south along the African coast? Or, is it possible that they were island hopping across the Mediterranean? Locating sites on the south coast helps us consider pathways and thus modes of behavior.”
“Our project is still in its early stages, but already we have identified and assessed over 40 sites of interest, of which about 17 are sites that have been relocated with greater precision based on older identifications,” Patania said.
She and her team prepared for their recent cave explorations by poring through the archives of local town libraries in Sicily, reading historical bulletins and news articles as far back as the 19th century.
The researchers identified potential sites and reviewed records and photographs of materials recovered by local avocational archaeologists. When possible, they interviewed workers that had been involved in earlier excavations, and they also talked with local recreational divers and fishermen.
For example, one of the co-authors on the new study is a retired tugboat captain. He has no formal scientific training, but he spent decades working on the decks of boats in and around the Port of Augusta.
“The moment I said that I was looking for paleosols, and that paleosols look like clay dirt that could be red or gray underwater, he said, ‘I know exactly what you are looking for,’” Patania said.
Patania also partnered with the superintendent of cultural and natural heritage of Siracusa and Ragusa (two provinces of Sicily) and the superintendent of the sea of Sicily to locate and recruit other local experts and stakeholders.
As the research has progressed, Patania also has spoken with officers in the Italian navy about training members of their specialized dive team to help identify underwater archaeological features. These divers spend a lot of time in local waters completing their regular tasks related to clearing ordnance and other debris from World War II.
“We’ve started with the area close to the coast, and we’re slowly going to move further out in the years to come,” Patania said.
Excavations continue
Two of the new sites in the PLOS ONE study may contain Upper Paleolithic human occupation traces, including fossil fauna, study authors said.
Corruggi is located at the southernmost tip of Sicily. The site was originally identified by other researchers in the 1940s.
“This site is where a second land bridge would have connected this island with the island of Malta,” Patania said.
“When we inspected this site, we found teeth from a European wild ass and stone tools,” she said. “Analyzing the remains from this site might give us insight on the very last leg of the human journey south into the southernmost coast of Sicily and off toward Malta.”
During summer 2024, project team members worked on excavating the second site, a cave called Campolato.
“Here we have discovered evidence for sea-level changes caused by the last glaciation and a localized earthquake that we are still investigating,” Patania said.
“We hope to reconstruct not only the timing of human occupation, but also the environment these people lived in and how they negotiated with natural events like earthquakes, climatic and environmental changes and maybe even volcanic eruptions,” she said.
Coastal and underwater cave sites in southern Sicily contain important new clues about the path and fate of early human migrants to the island, according to a new study in PLOS ONE.
Some of the sites are above ground, while others are submerged caves and hidden grottos accessible only by sea.
WashU archaeologists have recovered and analyzed stone tools and other items of interest from underwater caves and other coastal sites in southern Sicily.
Credit
Ilaria Patania
Funding: The Early Occupation of Sicily Project is funded in part by The Leakey Foundation, the Rust Family Foundation and the Archaeological Institute of America, with the support of Italian and Sicilian governmental bodies.
Bat species richness in San Diego, C.A. decreases as artificial lights, urbanization, and unconserved land increase, with Townsend's big-eared bat especially affected
PLOS
image:
Townsend’s big-eared bat captured in a mist net during field studies in California.
Bat species richness in San Diego, C.A. decreases as artificial lights, urbanization, and unconserved land increase, with Townsend's big-eared bat especially affected
Article Title: Quantification of threats to bats at localized spatial scales for conservation and management
Author Countries: U.S.A.
Funding: The United States Geological Survey Western Ecological Research Center and Ecosystems Mission Area provided funding and support, and the National Science Foundation provided funding through the INTERN program and grants IOS-1656867 and IOS-1656708. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Quantification of threats to bats at localized spatial scales for conservation and management
Article Publication Date
9-Oct-2024
Researchers discover new insights into bacterial photosynthesis
University of Liverpool
image:
A unique “flat” dimeric structure of bacterial photosynthetic reaction centre-light harvesting membrane complexes discovered by state-of-the-art cryogenic electron microscopy.
Credit: Professor Luning Liu, Chair of Microbial Bioenergetics and Bioengineering, University of Liverpool
Researchers at the University of Liverpool and collaborators have discovered new understanding of bacterial photosynthesis.
Using cutting-edge techniques, investigators have unveiled intricate detailed images of the key photosynthetic protein complexes of purple bacteria. These images shed new light on how these microorganisms harness solar energy.
The study, published today, not only advances scientists’ understanding of bacterial photosynthesis but also has potential applications in the development of artificial photosynthetic systems for clean energy production.
Like plants, many bacteria have evolved the remarkable ability to convert light into energy through a process called bacterial photosynthesis. This important biological reaction enables the microorganisms to play a crucial role in global nutrient cycles and energy flow in ecosystems and form the base of aquatic food chains. Studying ancient bacterial photosynthesis also helps to understand the evolution of life on Earth.
This latest work presents high-resolution structures of photosynthetic reaction centre−light harvesting complexes (RC−LH1) from Rhodobacter blasticus, a model organism for understanding bacterial photosynthesis.
The research team of collaborators from the University of Liverpool, the Ocean University of China, Huazhong Agricultural University and Thermo Fisher Scientific, captured detailed images of both monomeric and dimeric forms of the RC-LH1 membrane protein supercomplexes. These structures reveal unique features that distinguish R. blasticus from its close relatives, highlighting the remarkable variability in photosynthetic systems among purple bacteria.
Professor Luning Liu, Chair of Microbial Bioenergetics and Bioengineering, University of Liverpool said: “By revealing these natural photosynthetic mechanisms, we open new avenues for designing more efficient light-harvesting and energy transduction systems or cells. This study represents a significant step forward in our comprehension of how bacteria optimize their photosynthetic machinery, providing valuable insights that could inform future clean energy innovations.”
A unique feature of the RC-LH1 dimer of R. blasticus is its flatter conformation compared to its counterparts from other model species. This structure provides the foundation for specific membrane curvature and energy transfer efficiency in bacteria.
Unlike some related bacteria, R. blasticus lacks a protein component called PufY in the RC-LH1 structure. The study revealed that its absence compensates with additional light-harvesting subunits that create a more enclosed LH1 structure. This was determined to affect electron transport rates of the RC-LH1 structure.
This systematic study, integrating structural biology, in silico simulations, and spectroscopic studies, provides new insights into how bacterial photosynthetic complexes assemble and mediate electron transfer, crucial processes for energy production.
Lead researcher, Professor Luning Liu added: "Our findings demonstrate the structural diversity of photosynthetic complexes even among closely related bacterial species. This variability likely reflects different evolutionary adaptations to specific environmental conditions. We are thrilled that we can contribute such molecular details in the investigation of photosynthetic mechanisms and evolution."
Opioid drugs are highly effective at relieving pain but come with severe drawbacks. Their side effects range from dizziness to potentially fatal respiratory depression. Their illegal use contributes to nearly half a million deaths worldwide each year. Researchers from the University of Geneva (UNIGE) have discovered a molecule, called nanobody NbE, which binds tightly and durably to the cell receptors that usually bind to opioids, thereby blocking the drugs’ activity. Moreover, the scientists were able to create even smaller molecules that retain the same properties, which could prove far more effective than current treatments in mitigating the harmful effects of opioids. These findings are published in the journal Nature Communications.
Opioids are a large family of pharmaceuticals that include morphine, fentanyl and tramadol. These powerful drugs are mainly used as painkillers, but also trigger a euphoric effect by interacting with nerve cells in the brain. However, they are very addictive and produce dangerous side effects. Diverted from their original use, natural and synthetic opioids have become the deadliest drugs in the United States, and this global health crisis is now threatening Europe.
“We need to urgently develop new molecules to better mitigate the side effects for patients and manage the risks of opioid-related overdoses”, explains Miriam Stoeber, associate professor in the Department of Cell Physiology and Metabolism at UNIGE Faculty of Medicine, who initiated and coordinated the project. “To understand how a molecule works, we need to know how it affects the brain cells. In our study, we used tiny natural proteins derived from llama antibodies, called nanobodies, designed to bind specifically to the target receptor on the cell’s surface.”
The strong binding power of nanobody NbE
UNIGE researchers have found that NbE, one of the nanobodies under study, has the unique ability to bind so tightly and durably to specific opioid receptors that it prevents opioids from binding to these same receptors, therefore blocking the drug’s activity. “To determine how NbE binds to its target, we used high resolution structural biology methods, thanks to the new Dubochet Centre for Imaging”, describes Andreas Boland, assistant professor in the Department of Molecular and Cellular Biology at UNIGE Faculty of Science, and co-last author of the study. “We identified a unique binding mode where only a small portion of the nanobody is responsible for its correct receptor selectivity. Knowing precisely which part of the nanobody is at stake allows us to imagine new ways to induce the same effects with pharmaceuticals.”
Small molecules, large effects
While significantly smaller than antibodies, nanobodies remain quite large. They can be costly to produce and may not fully reach the target tissue in the body. In collaboration with the Prof. Steven Ballet team from the University of Brussels, the UNIGE research team synthesised in vitro a set of even smaller molecules mimicking the key part of NbE responsible for the selected binding to opioid receptors. “By durably blocking opioid receptors, our new molecules have the potential to reverse or reduce the deleterious side effects of opioids. In case of overdose, they could provide a better, longer lasting option than naloxone, the treatment currently in use. We will now refine their structure to improve even further their efficiency and facilitate their delivery to the targeted nerve cells in the brain”, concludes Miriam Stoeber.
New research identifies for the first time the genes that help plants grow under stressful conditions - with implications for producing more sustainable food crops in the face of global climate change.
Led by the University of East Anglia (UEA), the study reveals the genes that enable plants to make a novel anti-stress molecule called dimethylsulfoniopropionate, or DMSP. It shows that most plants make DMSP, but that high-level DMSP production allows plants to grow at the coast, for example in salty conditions.
The research also shows that plants can be grown under other stressful conditions, such as drought, when either they are supplemented with DMSP or plants are created that make their own DMSP. Such an approach may be of particular benefit in nitrogen-poor soils to improve agricultural productivity.
This is the first study to describe the genes that plants use to produce DMSP, identify why plants make this molecule, and discover that DMSP can be used to improve the stress tolerance of plants.
The findings are published today in the journal Nature Communications.
Prof Jon Todd, of UEA’s School of Biological Sciences, said: “Excitingly, our study shows that most plants make the anti-stress compound DMSP, but that the saltmarsh grass Spartina is special due to the high levels it accumulates. This is important because Spartina saltmarshes are global hotspots for DMSP production and for generation of the climate-cooling gas dimethylsulfide through the action of microbes that breakdown DMSP.”
Lead author Dr Ben Miller, also from UEA’s School of Biological Sciences, added: “This discovery provides fundamental understanding about how plants tolerate stress and offers promising avenues for improving the tolerance of crops to salinity and drought, which is important for enhancing agricultural sustainability in the face of global climate change.”
The research team included scientists from UEA’s School of Biological Sciences, School of Chemistry, Pharmacy and Pharmacology, and Ocean University of China.
They studied a species of saltmarsh cordgrass - Spartina anglica - that produces high levels of DMSP and compared its genes with those from other plants that produce the molecule, though mainly at low concentrations.
Many of these low DMSP-accumulating species are crop plants that cover large areas in the UK, such as barley and wheat.
The researchers identified three enzymes involved in the high-level production of DMSP in Spartina anglica.
DMSP plays crucial roles in stress protection and is integral to global carbon and sulfur cycling, as well as the production of climate-active gases.
Saltmarsh ecosystems, particularly those dominated by Spartina cordgrasses, are hotspots for DMSP production due to these plants being able to synthesize unusually high concentrations of the compound.
The research was funded by the Natural Environment Research Council (NERC) and the Biotechnology and Biological Sciences Research Council (BBSRC).
‘Elucidation of Spartina dimethylsulfoniopropionate synthesis genes enables engineering of stress tolerant plants’, is published in Nature Communications on October 9, 2024.
Spartina anglica growing on the Norfolk coast
The study involved measuring DMSP concentrations in leaf samples of Spartina anglica growing in the saltmarsh at Stiffkey, Norfolk, UK.
Spartina anglica growing on the Norfolk coast
The study involved measuring DMSP concentrations in leaf samples of Spartina anglica growing in the saltmarsh at Stiffkey, Norfolk, UK.
Credit
Ben Miller
Journal
Nature Communications
Article Title
Elucidation of Spartina dimethylsulfoniopropionate synthesis genes enables engineering of stress tolerant plants
Article Publication Date
9-Oct-2024
Satellite data shows massive bombs dropped in dangerous proximity to Gaza Strip hospitals in 2023
Researchers analyzed maps of Gaza bomb craters in October and November 2023 to study how close bombs came to hospital infrastructure
PLOS
image:
Image Caption: Fig 3. Hospital locations and the number of bomb craters within 800 m and 360 m of hospitals.
Credit: Image Credit: Kunichoff et al., 2024, PLOS Global Public Health, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)
Satellite data on the proximity of hundreds of M-84 bomb craters to hospitals in the Gaza Strip suggests that, as of November 2023, hospitals were not being given special protection from indiscriminate bombing, as mandated by international humanitarian law. That is one finding out of a new study published this week in PLOS Global Public Health by Dennis Kunichoff of Harvard University, and colleagues.
On October 7, 2023, Israel launched a major military campaign in the Gaza Strip in response to Hamas militant attacks in Israel. Among the munitions being used are United-States-provided Mark-84 (M-84) bombs, which are air-dropped explosive munitions that shoot more than 1000 pounds of steel fragments in all directions. M-84s have been shown to cause injury and damage infrastructure up to 800m from the point of detonation.
In the new study, researchers used publicly available geospatial data to identify hospitals in the Gaza Strip and combined it with CNN and New York Times satellite imagery investigations on the number and proximity of M-84 bomb craters which appeared in the Gaza Strip between October 7 and November 17, 2023. In total, the data included 36 hospitals and 592 bomb craters.
Overall, nine hospitals were within 360m of a bomb crater – considered a lethal range – and 30 additional hospitals were within 800m – the range that generally leads to injury and infrastructure damage. Two hospitals had as many as 21 and 23 bomb craters within 800m of their facilities and one hospital had 7 bomb craters within 360m. In total, 38 M-84 bombs were found to have been detonated within 800m of hospitals in the Israel-designated evacuation zone.
The authors say that the study was limited by its reliance on satellite information, so cannot be used to deduce actual damage to hospital functioning or casualties. In addition, the data was limited to the six-week time period in late 2023 for which satellite imagery was available and does not reflect the current situation on the ground.
“Given the proximity of these bomb craters to hospital areas, this study reveals concern for indiscriminate bombing in close proximity to hospital infrastructure which is afforded special protection under international humanitarian law,” the authors say.
Citation: Kunichoff D, Mills D, Asi Y, Abdulrahim S, Wispelwey B, Tanous O, et al. (2024) Are hospitals collateral damage? Assessing geospatial proximity of 2000 lb bomb detonations to hospital facilities in the Gaza Strip from October 7 to November 17, 2023. PLOS Glob Public Health 4(10): e0003178. https://doi.org/10.1371/journal.pgph.0003178
Author Countries: Lebanon, Palestine, United States
Funding: The authors received no specific funding for this work.
