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As the scientific community continues researching the novel coronavirus, experts are developing new drugs and repurposing existing ones in hopes of identifying promising candidates for treating symptoms of COVID-19.

Scientists can analyze the molecular dynamics of drug molecules to better understand their interactions with target proteins in human cells and their potential for treating certain diseases. Many studies examine drug molecules in their dry, powder form, but less is known about how such molecules behave in a hydrated environment, which is characteristic of human cells.

Using neutron experiments and computer simulations, a team of researchers from the Department of Energy's (DOE) Oak Ridge National Laboratory (ORNL) delved into how some of these drugs behave at the molecular scale when exposed to water. The scientists conducted this research using neutron scattering instruments at the ORNL Spallation Neutron Source (SNS).

They found that certain parts of the molecules were able to move more easily once hydrated. This factor could influence how efficiently a drug takes on shapes associated with different biological functions, such as binding to a target protein and inhibiting viral activity. The results of this project, now published in ACS Omega and the Journal of Physical Chemistry Letters, could help experts understand the mechanisms by which drug molecules have the potential to mitigate the impact of viral infection.

"The human body is approximately 60 percent water. When drugs are in our bodies and interacting with water molecules, they are not going to move the same as when they are in a crystalline state," said Matthew Stone, an ORNL instrument scientist involved with the study. "Having a fundamental understanding of how the drugs might act in human bodies could help scientists determine which molecules are effective against the virus."

The study analyzed three molecules: remdesivir, an antiviral drug developed to treat the Ebola virus disease; dexamethasone, a steroid commonly used for autoimmune and inflammation conditions; and hydroxychloroquine, an immunosuppressant drug created for preventing and treating malaria. The team's early work focused on hydroxychloroquine, when it was being investigated as a COVID-19 treatment, but as new candidates were identified by the medical community, the project shifted to studying remdesivir and dexamethasone.

The team specifically examined the drug molecules' methyl groups, which are functional groups consisting of one central carbon atom and three branching hydrogen atoms. Methyl groups are often included in drug molecules because they can significantly improve drug potency, a phenomenon known as the magic methyl effect. Some scientists believe this improvement occurs because methyl groups can impact how drugs bind to target proteins, dissolve in liquids, and are broken down by enzymes.

Using the BASIS, VISION, SEQUOIA, and CNCS spectrometers at SNS, the researchers measured methyl group dynamics within dry and variously hydrated drug samples. Each instrument provides a unique view into how molecules vibrate or change shape and how much energy these movements require. Combining these different data sets enabled the team to build a comprehensive picture of how these drug molecules behave.

"Using spectroscopy, we can look into how atoms are moving in a material. With this technique, we're trying to help build up a library of how these drug molecules work at the atomic scale," said ORNL instrument scientist and study co-author Timmy Ramirez-Cuesta.

Neutrons are uniquely suited for this research because they interact strongly with light elements like hydrogen, which are abundant in drug molecules, and their energy levels can be similar to the energies of moving atoms. The similarity allows neutrons to detect the energy associated with subtle atomic vibrations and rotations with a high degree of accuracy. "The SNS is extremely useful because the facility's instruments have unique specializations that cover different energy ranges," said Stone.

The researchers then relied on computer modeling to link certain molecular movements to specific energy peaks in their data, like identifying different musical instruments when listening to a song.

"When you measure the energy levels of molecular motions, at first you don't know exactly what specific movements are causing energy peaks. However, we can simulate molecular motions in a model and calculate the energy required for certain movements to happen," said Yongqiang Cheng, an ORNL instrument scientist involved with this research. "By aligning simulated energy peaks with measured energy peaks, you can better understand how a molecule is moving."

The results showed that exposing the drugs to water causes the molecules to become more disordered, similar to how a sugar cube starts to dissolve when wet. The researchers found that, when the drug molecules became more disordered as a result of hydration, the methyl groups required considerably less energy to rotate.

"Introducing the drug samples to water often caused the material to become more disordered in our study, and in this disordered state, the methyl groups could move more easily between configurations," said ORNL instrument scientist Alexander Kolesnikov and study co-author.

The findings suggest that analyzing drug candidates in a hydration-induced disordered state could offer more insight into drug molecule dynamics in human bodies.

"Many scientists study the crystalline structure of different drugs to better understand how they function, but we found, in reality, these molecules can behave quite differently," said Eugene Mamontov, an ORNL instrument scientist and corresponding author of the published studies.

Of course, the methyl group is just one part of these drug molecules, and more research is needed to better understand how these drugs might act in human cells. Additionally, to gain further insight into the potency of these drugs, scientists also need to study how their molecular motions change when interacting with target proteins.

The research team's next steps include examining other therapeutic candidates that have shown potential as COVID-19 treatments.

"This is a constantly evolving project, but our overarching aim is to use the strong spectroscopy expertise at ORNL to help scientists learn more about these drug molecules and get one step closer to finding effective solutions for treating this disease," said Cheng.

Current advice from the America Dental Association tells you that if your gums bleed, make sure you are brushing and flossing twice a day because it could be a sign of gingivitis, an early stage of periodontal disease. And that might be true. So if you are concerned, see your dentist. However, a new University of Washington study suggests you should also check your intake of vitamin C.

"When you see your gums bleed, the first thing you should think about is not, I should brush more. You should try to figure out why your gums are bleeding. And vitamin C deficiency is one possible reason," said the study's lead author Philippe Hujoel, a practicing dentist and professor of oral health sciences in the UW School of Dentistry.

Hujoel's study, published Feb. 1 in Nutrition Reviews, analyzed published studies of 15 clinical trials in six countries, involving 1,140 predominantly healthy participants, and data from 8,210 U.S. residents surveyed in the Centers for Disease Control and Prevention's Health and Nutrition Examination Survey. The results showed that bleeding of the gums on gentle probing, or gingival bleeding tendency, and also bleeding in the eye, or retinal hemorrhaging, were associated with low vitamin C levels in the bloodstream. And, the researchers found that increasing daily intake of vitamin C in those people with low vitamin C plasma levels helped to reverse these bleeding issues.

Of potential relevance, says Hujoel, who is also an adjunct professor of epidemiology in the UW School of Public Health, both a gum bleeding tendency and retinal bleeding could be a sign of general trouble in one's microvascular system, of a microvascular bleeding tendency in the brain, heart and kidneys.

The study does not imply that successful reversing of an increased gingival bleeding tendency with vitamin C will prevent strokes or other serious health outcomes, Hujoel stresses. However, the results do suggest that vitamin C recommendations designed primarily to protect against scurvy -- a deadly disease caused by extremely low vitamin C levels -- are too low, and that such a low vitamin C intake can lead to a bleeding tendency, which should not be treated with dental floss.

Consequently, Hujoel does recommend people attempt to keep an eye on their vitamin C intake through incorporation of non-processed foods such as kale, peppers or kiwis into your diet, and if you can't find palatable foods rich in vitamin C to consider a supplement of about 100 to 200 milligrams a day.

If someone is on a specialized diet, such as a paleo diet, it's important that they take a look at their vitamin C intake, Hujoel said. "Vitamin C-rich fruits such as kiwis or oranges are rich in sugar and thus typically eliminated from a low-carb diet."

This avoidance may lead to a vitamin C intake that is too low and is associated with an increased bleeding tendency. People who exclusively eat lean meats and avoid offal, the vitamin-rich organ meats, may be at a particularly high risk for a low vitamin C intake.

The association between gum bleeding and vitamin C levels was recognized more than 30 years ago. In fact, two studies co-authored by former dean of the UW School of Dentistry Paul Robertson (published in 1986 and 1991) identified gum bleeding as a biological marker for vitamin C levels.

However, this connection somehow got lost in dental conversations around bleeding gums.

"There was a time in the past when gingival bleeding was more generally considered to be a potential marker for a lack of vitamin C. But over time, that's been drowned out or marginalized by this overattention to treating the symptom of bleeding with brushing or flossing, rather than treating the cause," Hujoel said.

Hujoel's literature review also determined that "retinal hemorrhaging and cerebral strokes are associated with increased gingival bleeding tendency, and that (vitamin C) supplementation reverses the retinal bleeding associated with low (vitamin C) plasma levels."

So, missing the possible connection between gum bleeding and low levels of vitamin C has the potential to have serious health consequences.

The study authors write: "A default prescription of oral hygiene and other periodontal interventions to 'treat' microvascular pathologies, even if partially effective in reversing gingival bleeding as suggested in this meta-analysis, is risky because it does not address any potential morbidity and mortality associated with the systemic microvascular-related pathologies."

Flinders University researchers have discovered a new anti-inflammatory role for well-known blood clot protein fibrinogen, which could support targeted new treatments for kidney, heart and other common diseases.

The study in Redox Biology describes how fibrinogen can be protective against hypochlorite - a chemical generated by the body during inflammation - and so act as a kind of antioxidant in blood plasma.

"Our team found that fibrinogen, which forms extraordinarily large assemblies when it reacts with hypochlorite, doesn't harm cells in the same way as hypochlorite-modified albumin which exacerbates kidney and heart disease, and many other serious health conditions," says research leader Dr Amy Wyatt, from the Flinders College of Medicine and Public Health.

"While fibrrinogen is less abundant than the main blood protein albumin, it's more susceptible to reacting with hydrochlorite in the body."

The accumulation of hypochlorite-modified albumin can cause harm in a patient, however hypochlorite-modified fibrinogen seems relatively harmless.
This discovery could ultimately help us to design therapies that block the bad effects of hypochlorite-modified albumin," Dr Wyatt says.

"When we figure out precisely how these distinctly different protein molecules behave, then it might be possible to block the disease-promoting activities of hypochlorite-modified albumin using drugs," say the
Flinders research group mapping how protein molecules normally function and how these functions change when protein molecules are damaged by biological stresses such as reaction with hypochlorite.

Additionally, the scientists say the research could reveal new biomarkers for inflammatory disease.

Soil temperature has a significant impact on land-atmosphere interaction within the Earth system, affecting surrounding ecology, agriculture, and much more. This influence is a primary component of what is called a "thermal regime" of land, or a regular pattern of temperature change within the soil. Climatologists are intrigued by fluctuating soil temperatures, especially during the first decade of the 21st century where global surface warming has slowed down. The thermal regime, according to scientists, is greatly influential on climate, particularly seasonal climate prediction. Now, studies are focused on determining whether or not soil temperatures also respond to slower surface warming, therefore entering a warming slowdown, or hiatus.

"Soil temperatures normally are closely coupled with the upper surface air temperature," said Dr. Haoxin Zhang, the lead author of the most recent study published in Advances in Atmospheric Sciences, "...there are also many other factors including solar radiation, snow cover, soil memory, etc., that may alter the soil temperatures."

During the recent global warming hiatus, the strongest warming slowdown throughout China occurred during winter. Observed surface air temperatures and soil temperatures at multiple depths showed consistent cooling trends at many Chinese reporting stations. However, in northeastern China, surface air temperature seemed less influential on soil temperature. In this region, soil data retrieved from 0cm to a depth of 80cm suggested a continuing warming trend despite the surface air warming hiatus.

"The enhanced thermal insulation effect of the snow cover reduced the heat loss from the soils," said Dr. Zhang. To confirm their results, the team investigated snow cover along with other direct and indirect soil temperature influences in northeastern China. The research further showed that the increasing snow depth in northeastern China may be the main reason for the continued warming trend in soil temperatures. Dr. Zhang further stated "...this is important for the agriculture."

In addition to the thermal insulation effect of snow cover, the ability for soil to record human changes and environmental influences, or "soil memory" is also important, especially at greater depths.

"This means the effects of various factors may be 'memorized' in the deep soil temperatures, which in turn contribute to the seasonal climate prediction." said Dr. Naiming Yuan, the corresponding author of the study. "The thermal conditions from previous seasons have stronger impacts than those from the surface air temperatures or the snow cover of the considered season at deeper layers (around 160cm or deeper)."

(Singapore--January 30, 2021 11:00 p.m. SPT/January 30, 2021 10:00 a.m. EST)-- A phase III study examining whether messenger (m)RNA expression correlated with sensitivity or resistance to chemotherapy did not confer a statistically significant advantage in overall survival for patients with resected stage II-III non-small cell lung cancer (NSCLC), according to research presented at the International Association for the Study of Lung Cancer World Conference on Lung Cancer.

Lung cancer researchers and clinicians have sought methods to improve chemotherapy's modest 5% overall survival rate for patients with NSCLC. Dr. Silvia Novello, professor of medical oncology at the University of Torino at San Luigi Gonzaga Hospital, Orbassano, Italy, and a large group of European researchers evaluated the predictive utility of the mRNA expression levels of molecular markers, mRNA expression levels of molecular markers, excision repair cross-complementing group ERCC1 and thymidylate synthase (TS).

The primary research aim of the study was to investigate if adjuvant pharmacogenomic-driven approach was able to improve overall survival in completely resected NSCLC.

The researchers randomly assigned 773 patients from 31 Italian and German centers (one in Poland) within 5-8 weeks after radical surgery, adopting a unique study design. Genomic analyses were performed soon after surgery and then patients were randomly assigned in each of the four genomic subgroups to investigator's choice of platinum-based chemotherapy or to tailored treatments defined by biomarkers.

Because cisplatin activity is supposed to be limited in presence of high ERCC1 expression levels, patients allocated to tailored treatment received or single-agent docetaxel if TS level was high (n = 148) or pemetrexed if TS was low (n = 43). In the subgroup with low ERCC1 expression levels, patients received cisplatin/gemcitabine if TS level was high (n = 101) or cisplatin/pemetrexed if TS was low (n = 92). The most frequent doublets used in the control arm were cisplatin/gemcitabine (n = 159) and cisplatin/vinorelbine (n = 123) (others, n = 28) .

Median follow-up time was 28.2 months. The estimated median overall survival in the control arm was 83.5 months vs 96.4 months in the tailored arm (95% CI: 0.55-1.04; hazard ratio (control vs tailored) was 0.76 ).

"In completely resected stage II-III NSCLC, tailoring adjuvant chemotherapy on the basis of the mRNA expression of selected genes does not confer a statistically significant survival advantage in terms of overall survival and relapse-free survival. Toxicity was less commonly reported in the customization arms," Novello reported.

"The ITACA study is the largest adjuvant study tailored to ERCC1/TS status, and the results have been long-awaited," said IASLC President Dr. Tetsuya Mitsudomi. "This trial should be praised for the mandated genomic analysis that was accomplished within a reasonably short timeframe before random assignment. In addition, this trial confirmed that there is no biomarker strong enough to predict the efficacy of cytotoxic chemotherapy; however, the concept of customizing adjuvant therapy according to the genomic status of patients' tumors is valid, leading to the recent demonstration in the ADAURA study of the superiority of osimertinib in delaying the postoperative recurrence of disease in patients with EGFR-mutated NSCLC."

In just one year, COVID-19 has killed more than 400,000 Americans, and infected more than 24 million others. But a new study shows just how unevenly those deaths and cases have played out across the country.

It finds that the more disadvantaged a county's population was before the pandemic, the higher the toll of coronavirus last spring and summer.

That level of disadvantage, measured on a standard scale called the Social Vulnerability Index (SVI), tracked closely with the number of cases and deaths per 100,000 residents in each county, according to the new University of Michigan study.

The ten-point SVI score combines many measures of the social disadvantage of a county's population, with higher scores meaning greater disadvantage. For every point higher on the ten-point SVI scale, counties had 14% higher incidence of COVID-19 cases, and 14% more deaths per 100,000 people, the team reports in JAMA Network Open.

That translates to 87 excess COVID-19 cases per 100,000 people, and 3 excess COVID-19 deaths per 100,000 people, for every step up the SVI scale.

Cases also rose faster in higher-SVI counties than in lower-SVI ones during the months the researchers analyzed, from late March to late July 2020.

Since half of COVID-19 cases spring from virus spread by people who don't have symptoms, the findings have important implications for all Americans, say the researchers from the U-M Institute for Healthcare Policy and Innovation.

"These findings highlight that underlying inequality and social disadvantage, and its role in promoting the spread of coronavirus, is a problem that affects all of us, no matter where we live," says Renuka Tipirneni, M.D., M.Sc., the study's senior author. "This evidence contradicts the perception that COVID-19 mostly affects just one set of people in one kind of area."

She adds, "While the first surge was mainly in urban areas with high percentages of Black and Latinx residents, as time went on some of highest rates of cases and deaths were in rural counties with predominantly white populations. But across the board, we find the areas hardest-hit by the disease were linked by higher rates of social disadvantage."

The SVI, which factors in everything from income, language and education to housing, race and disability, is calculated by the Centers for Disease Control and Prevention based on national Census data.

Higher case and death rates were also seen in areas that had higher rates of measures that aren't included in the standard SVI, such as obesity, mass transit use, food insecurity and adults who lack health insurance.

Tipirneni, a primary care physician in the U-M Medical School's Department of Internal Medicine and health services researcher who has worked in multiple health care settings, worked with first author and senior statistician Monita Karmakar, Ph.D., M.S. for the intensive data analysis. Coauthor Paula Lantz, Ph.D., a professor and associate dean at U-M's Ford School of Public Policy, helped evaluate the policy implications of the findings.

"Our findings highlight that there are pockets of disadvantage everywhere in America, and that they are playing a large role in the pandemic that's affecting all of us as we interact with one another," says Karmakar.

Factors most associated with higher impacts

The team looked at how SVI and other social measures related to 4.3 million cases and 147,074 deaths reported during the first 6 months of the pandemic in the US. They accounted for variation in population density and COVID testing rates.

The team then analyzed the SVI for each county. The ten-point score, which is expressed in terms of scores from 0.1 to 1.0, melds measures that include poverty rate, income and education level, housing type, English language ability, single-parent families, percent of people over 65 or under 17, access to a personal vehicle, racial and ethnic minority population percentage, and disability.

Digging down into the individual factors that made up the social vulnerability index, the researchers found that the higher the percentage of racial and ethnic minorities in a county's population, and the higher the percentage of people with limited English skills, the higher the COVID-19 case and death rates. The counties measuring highest on these factors had a 22% increase in case rate for every point up on their overall SVI score, and a 17% increase in death rate.

The percentage of the population that lives in over-crowded housing or in single-parent households was also associated with higher case incidence and death rates.

Looking at factors that aren't included in the official SVI, the researchers found many linkages with COVID-19. Interestingly, the concentration of health care resources available in the county did not seem to make a significant difference, though Tipirneni cautions that as more hospitals become overwhelmed with COVID-19 patients in the fall and early-winter surges, that may have changed.

However, a higher rate of obesity among a county's residents, the more adults that lacked health insurance, the more adults who rely on public transportation to get to and from work, and the more people who have unstable food supplies, the higher the rates of COVID-19 cases and deaths.

Most-impacted counties

Of the 3,137 counties analyzed, Trousdale County, Tennessee came in as the county with the highest incidence of COVID-19 cases during the study period, with 16,348 cases per 100,000 people by the end of July 2020. This was mainly linked to a COVID-19 outbreak in spring that sickened more than 1,300 inmates at a correctional center located there. This helped explain its high caseload despite having an SVI score of 0.52, near the middle of the scale.

But the next four counties with the highest COVID-19 case rates from January through July were all much higher on the SVI scale, including Lake County, TN and Lee County, Arkansas with SVI scores over 0.9. Dakota County, Nebraska (0.86) and Buena Vista County, Iowa (0.74), came in fourth and fifth. The latter two are also rural counties with small populations that are home to a prison that was the center of a large outbreak.

The county with the highest death rate, Hancock County, Georgia, had an overall SVI score of 0.80, with a population of 8,000 people seeing a high number of nursing home deaths. The four next-highest counties - three of them in Georgia, and one in New Mexico - all had SVI scores over 0.9.

The study team plans to make a full list of the SVI scores and COVID-19 incidence and mortality rates for every county in the study available online.

The study did not include data from for U.S. territories, nor for New York City because at the time of the analysis, the city did not release county-level data for the five counties that make it up. However, the authors performed an analysis that considered New York City data as if it were a single county, and found it did not change their findings.

Policy implications

The authors note that the new findings support the broader importance of "social determinants of health" -- upstream factors about a person's life circumstances that cause differences in their risk of health conditions. Such determinants are known to put someone at higher risk of the conditions that would put them at higher risk of developing a severe case of COVID-19 if they get infected, including diabetes, high blood pressure and lung disease.

Counties with high SVI scores are likely to have higher percentages of essential workers in frontline jobs. They're also likely to have more people living in homes and commuting in conditions that make social distancing and isolation of the sick difficult.

"The longstanding inequality that led to the higher social vulnerability scores in the hardest-hit counties is likely to get worse because of the pandemic," says Lantz. "The tragic Catch-22 of the COVID-19 pandemic is that its economic and social consequences are going to further exacerbate social inequalities and community-level social vulnerability. Investments in public policies that protect everyone, like paid sick leave, affordable housing, high-quality education and health insurance are needed to reduce the social inequalities that drive every type of health inequality, including COVID-19."

As policymakers grapple with the root causes, immediate impacts and downstream effects of the inequities identified, the researchers hope the new findings will help them target their efforts.

Immediate efforts might include public outreach campaigns aimed at people with lower English proficiency, focused efforts to expand COVID-19 testing, treatment and vaccination in the hardest-hit areas, and assistance with housing and food coordinated among government and nonprofit service agencies.

The team previously calculated COVID-19 incidence and mortality rates by SVI for the counties of Michigan, and provided the data to the state. It has been shared with the state's task force that targets COVID-19 testing locations and other services.

In the meantime, the team hopes that future research could look at even smaller geographic areas, down to the community, ZIP code or Census tract level, as well as data about the types of jobs worked by people in a given area. New efforts by the Agency for Healthcare Research and Quality, and the local-area social vulnerability resources from the University of Wisconsin and the Robert Wood Johnson Foundation, can also help further efforts to study and act on differences in advantage.

High-intensity tropical cyclones have been moving closer to coasts over the past 40 years, potentially causing more destruction than before.

The trend of tropical cyclones - commonly known as hurricanes or typhoons - increasingly moving towards coasts over the past 40 years appears to be driven by a westward shift in their tracks, say the study's authors from Imperial College London.

While the underlying mechanisms are not clear, the team say it could be connected to changes in tropical atmospheric patterns possibly caused by climate change. The research is published today in Science.

Globally, 80 to 100 cyclones develop over tropical oceans each year, impacting regions in the Pacific, Atlantic and Indian Oceans and causing billions of dollars of damage.

Lead author Dr Shuai Wang, from the Department of Physics at Imperial, said: "Tropical cyclones are some of the most devastating natural hazards in terms of how destructive and frequent they are in coastal regions.

"Our study shows they are likely becoming more destructive as they spend more time along coastlines at their highest intensities. The risk to some coastal communities around the world may be increasing and that will have profound implications over the coming decades."

The team analysed global data from 1982-2018 on tropical cyclone formation, movement and intensity mainly gathered from satellite observations. They found that at maximum intensity, cyclones were on average getting 30km closer to coastlines per decade. There were also on average two more cyclones per decade within 200km of land.

These increases did not necessarily mean more cyclones made landfall (reached land). However, the 'near-misses' or 'indirect-hit' cyclones near coasts can still cause damage, such as Hurricane Sandy in 2012 and Hurricane Dorian in 2019, both of which skirted along the US coast for a considerable time before making landfall.

The paper's other author, Professor Ralf Toumi from the Department of Physics and Co-Director of the Grantham Institute - Climate Change and Environment at Imperial, said: "We need to understand all aspects of tropical cyclones and this new study shows how their locations are changing. This often gets less attention than changes in their intensity but is at least as important."

Previously, studies have shown that the maximum intensity of tropical cyclones is found further towards the poles. However, this does not necessarily mean these more poleward storms are more devastating. The new findings show cyclones at maximum intensity are also migrating westward, bringing them closer to coastlines and increasing their potential for damage.

The westward migration appears to be driven by anomalous 'steering' - the underlying flow in the atmosphere that carries cyclones along their tracks. The exact mechanism for this enhanced westward steering is unknown, but it may be due to the same underlying mechanism for poleward migration of cyclones as rising temperatures cause atmospheric patterns to shift.

The team will next use climate simulations to determine the underlying mechanism behind these historical shifts and project potential future shifts in tropical cyclone tracks towards global coastal regions.

An international team of researchers led by Oxford Brookes University shows that black howler monkeys in Mexico not only remember where important events took place in their habitat, but also when to return to such locations.

The researchers recorded the behaviour of five groups of black howler monkeys accumulating over 3,000 hours of field observations at Palenque National Park, southern Mexico.

Expert fruit foragers

Black howler monkeys were observed navigating deliberately towards out of sight fruit trees that were ripening. Fruit is a desired food by many animals in rainforests so being able to anticipate when fruit is going to be available and where, is a great strategy to forage ahead of competitors. The monkeys selected a small subset of fruit trees with easy-to-remember ripening cycles - showing, like humans, a tendency to minimise information processed during navigation.

Lead researcher Dr Miguel de Guinea expert in Evolutionary Anthropology, Oxford Brookes University said: "In the same way that we remember the location of our favourite restaurants, primates remember the locations of their favourite fruit trees in rainforests. But there is a clear difference: fruit trees, instead of following established opening hours, can produce fruit at different times of the year during very specific windows. It is fascinating and impressive that a relatively small-brained primate can memorise the ripening patterns of many different trees and anticipate the emergence of fruits."

Vocal warning at set locations to ward off rival troops

The research found that black howler monkeys travelled in long, straight lines, before reaching a location where they had previously encountered a neighbouring troop. After reaching these locations, the monkeys used loud calls to warn neighbouring primate groups of their territorial range. The groups of monkeys started travelling in a completely different direction afterwards, indicating that they purposely navigate to these set locations.

Co-researcher Dr Sarie Van Belle from the University of Texas at Austin, USA commented: "We already know that in howler monkeys, loud vocalisation plays a central role in defending their home ranges. With this study, we have learned that they return to areas where neighbouring groups had breached the home range border, to vocally announce that the area was occupied."

CHAMPAIGN, Ill. -- Childhood trauma could affect the trajectory of multiple sclerosis development and response to treatment in adulthood, a new study in mice found.

Mice that had experienced stress when young were more likely to develop the autoimmune disorder and less likely to respond to a common treatment, researchers at the University of Illinois Urbana-Champaign found. However, treatment that activated an immune-cell receptor mitigated the effects of childhood stress in the mice.

Multiple sclerosis is a progressive autoimmune disease in which the body attacks and strips away the protective coating around neurons, resulting in a wide range of neurological symptoms. Both genetic and environmental factors play a role in MS development.

Previous work has shown that early-life trauma increases susceptibility to developing more severe MS, but researchers have not been able to determine how, said Makoto Inoue, a professor of comparative biosciences at Illinois. In the new study, published in Nature Communications, Inoue's group studied a mouse model of MS. The mice were genetically susceptible to experimental autoimmune encephalomyelitis, the model most widely used for studying MS.

The researchers watched the development and progression of EAE in mice that had been briefly separated from their mother and given a salene injection while young and compared it with mice that had not experienced the same stress.

"Mice that had early-life trauma were more susceptible to EAE disease development and suffered prolonged motor paralysis with severe neuronal damage in the central nervous system, which we found was caused by a heightened immune response," said graduate student Yee Ming Khaw, the first author of the study.

The researchers traced the EAE triggers to the immune system - in particular, a receptor on immune cells that binds to the stress hormone norepinephrine. The researchers found that childhood stress in the mice triggered a prolonged release of norepinephrine. The receptor was activated for long periods of time, which led the cells to decrease its expression - leaving the immune system less equipped to respond to the stress and inflammation of EAE.

Importantly, mice that developed EAE after stress in their childhoods did not respond to treatment with interferon beta, one of the initial therapies most widely prescribed to individuals with MS. Meanwhile, the drug effectively prevented EAE progression in mice without childhood stress, Khaw said.

Next, the researchers treated the mice with a compound that boosts the receptor's response. The treatment prevented paralysis and slowed damage to the spinal cord. In addition, mice that received the treatment responded to interferon beta treatment, though they had not responded before.

"This work suggests that individuals with experience of childhood trauma develop autoimmune disease with symptoms and mechanisms that greatly differ from their peers with no history of childhood trauma, and may need different medical treatment," Inoue said. "This receptor activator may be a therapeutic drug for MS patients with a history of childhood trauma."

Next, the researchers plan to verify the mechanisms of the receptor, and to perform translational studies to verify whether boosting the receptor in human patients with MS gives the same benefits as it did for the mice with EAE.

"We believe that the best approach to addressing autoimmune diseases in individuals with a history of childhood trauma or other risk factors is a comprehensive and personalized medicine approach that addresses the whole person," Inoue said.

Boulder, Colo., USA: Sixteen articles were published online ahead of print for GSA Bulletin in January. Topics include insights from the Sawtooth metamorphic complex in Idaho, fingerprinting sand from ancient rivers, eroding Cascadia, and the Troodos ophiolite.

Three-dimensional geometry and growth of a basement-involved fault network developed during multiphase extension, Enderby Terrace, North West Shelf of Australia
Hongdan Deng; Ken McClay

Abstract: Basement fault reactivation, and the growth, interaction, and linkage with new fault segments are fundamentally three-dimensional and critical for understanding the evolution of fault network development in sedimentary basins. This paper analyzes the evolution of a complex, basement-involved extensional fault network on the Enderby Terrace on the eastern margin of the Dampier sub-basin, North West Shelf of Australia. A high-resolution, depth-converted, 3-D seismic reflection data volume is used to show that multiphase, oblique extensional reactivation of basement-involved faults controlled the development of the fault network in the overlying strata. Reactivation of the pre-existing faults initially led to the formation of overlying, en échelon Late Triassic?Middle Jurassic fault segments that, as WNW-directed rifting progressed on the margin, linked by breaching of relay zones to form two intersecting fault systems (F1 and F2?F4). Further reactivation in the latest Jurassic?Early Cretaceous (NNW-SSE extension) produced an additional set of en échelon fault arrays in the cover strata. The final fault network consists of main or principal faults and subordinate or splay faults, together with branch lines that link the various components. Our study shows that breaching of relay ramps and/or vertical linkages produces vertical and horizontal branch lines giving complex final fault geometries. We find that repeated activity of the basement-involved faults tends to form continuous and planar fault architectures that favor displacement transfer between the main constituent segments along strike and with depth.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35779.1/594311/Three-dimensional-geometry-and-growth-of-a

Age and deposition of the Fort Crittenden Formation: A window into Late Cretaceous Laramide and Cenozoic tectonics in southeastern Arizona
Emilia A. Caylor; Barbara Carrapa; Kurt Sundell; Peter G. DeCelles; Joshua M. Smith

Abstract: The Upper Cretaceous Fort Crittenden Formation exposed in the Santa Rita and Huachuca Mountains of southeastern Arizona is a syntectonic deposit that has been associated with Laramide tectonic activity. However, the spatio-temporal relationships among Cretaceous sedimentation, magmatism, basement exhumation, and possible flat slab-related processes in the southern Laramide region remain poorly understood. Age controls for uplift and erosion of local topography and syntectonic deposition in response to deformation remain particularly poor. The Fort Crittenden Formation comprises 800?2500 m of locally derived fluvial to alluvial fan sedimentary rocks and records paleodrainage reorganization in response to active tectonics. Changes in sedimentary facies, provenance, and paleoflow suggest deposition in a tectonically partitioned intraforeland basin. New detrital zircon data constrain the timing of deposition of the Fort Crittenden Formation between ca. 86 Ma and ca. 76 Ma. The lack of depositional age zircons throughout the majority of the Fort Crittenden Formation is consistent with a magmatic lull in the Cordilleran arc between ca. 90 Ma and ca. 76 Ma. The overlying Salero Formation and Late Cretaceous intrusions are expressions of renewed magmatism in southeastern Arizona at ca. 75 Ma. New Lu-Hf data indicate that magmas evolved from contamination of old juvenile crust. When interpreted in conjunction with other regional data sets, our study indicates that the Laramide deformation front migrated eastward into southwestern New Mexico by 75 Ma. Thermal modeling of apatite fission track and (U-Th)/He data from granitic clasts are consistent with Late Cretaceous?Paleocene (ca. 76?55 Ma) heating related to magmatism and cooling and exhumation during the Eocene and Oligocene.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35808.1/594257/Age-and-deposition-of-the-Fort-Crittenden

Mesozoic crustal melting and metamorphism in the U.S. Cordilleran hinterland: Insights from the Sawtooth metamorphic complex, central Idaho
Chong Ma; David A. Foster; Paul A. Mueller; Barbara L. Dutrow; Jeffery Marsh

Abstract: In this study, we present whole-rock geochemistry and Sm-Nd data; zircon trace element, U-Pb, and Lu-Hf data; titanite U-Pb dating; and structural analysis of igneous and metasedimentary rocks of the Sawtooth metamorphic complex that provide insight into regional metamorphism, partial melting, and crustal thickening in the Idaho batholith segment of the Cordilleran orogen. Four magmatic events are revealed: (1) pre-tectonic felsic magmatism at ca. 156 Ma, (2) syn-tectonic mafic and felsic magmatism between ca. 100 Ma and ca. 92 Ma, (3) felsic magmatism concurrent with late-stage deformation at ca. 89?84 Ma, and (4) post-tectonic felsic magmatism at ca. 77 Ma. The multiple generations of felsic magmatism include a variety of sedimentary- and igneous-derived granitoids distinguished by zircon trace element compositions (e.g., U/Ce versus Th and Ce/Sm versus Yb/Gd) and were sourced from progressively more evolved crustal components as shown by Lu-Hf and Sm-Nd isotopic data. U-Pb data of metamorphic zircons and titanites from high-grade metasedimentary rocks suggest that regional metamorphism occurred from ca. 100?93 Ma, which was characterized by granulite-facies partial melting and concurrent growth of metamorphic zircons and garnets. The episodic magmatism in the Sawtooth metamorphic complex records pervasive melt migration in a hot, mid-crustal setting at ca. 100?92 Ma and additional magma ascent in a cool, upper-crustal setting at ca. 77 Ma. The uplift of the Sawtooth metamorphic complex from mid- to upper-crust was likely caused by underthrusting at lower crustal levels coupled with erosion and thinning of the upper crust. This work suggests that the crust of the Cordilleran hinterland in the Idaho batholith region underwent significant thickening from ca. 100?84 Ma, and a crust of Andean-like thickness was probably achieved by ca. 84 Ma. By ca. 77 Ma, the central Idaho crust started to thin likely due to mid-crustal flow and surface erosion. The new data from the Sawtooth metamorphic complex are consistent with the two major magmatic flare-ups in the Late Jurassic and Late Cretaceous in the U.S. Cordilleran orogen.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35837.1/594189/Mesozoic-crustal-melting-and-metamorphism-in-the-U

Contribution of an Eastern Indochina-derived fragment to the formation of island arc systems in the Philippine Mobile Belt
Lin Gong; Pete Hollings; Yu Zhang; Jing Tian; Dengfeng Li ...

Abstract: The Philippine Mobile Belt is a complex plate boundary with multiple terranes in Southeast Asia, yet its early tectonic evolution is still not fully understood due to a scarcity of solid evidence. Here we report new whole rock geochemical, Sr-Nd isotopic, and zircon U-Pb-Hf isotopic data for Cretaceous-Miocene arc magmatic rocks from the Cebu and Bohol Islands, Philippine Mobile Belt. Bulk geochemical data display arc affinities with enriched large ion lithophile elements (e.g., Sr and Ba) and depleted high field strength elements (e.g., Nb, Ta, and Ti). The high positive εNd(t) (+4.6 to +9.1) values and low initial 87Sr/86Sr ratios (0.7032?0.7048) suggest that these igneous rocks were generated by partial melting of mantle wedge in an arc setting. U-Pb dating of zircons revealed Cretaceous (ca. 120?90 Ma), middle Eocene to early Oligocene (ca. 43?30 Ma), and middle Miocene (ca. 14 Ma) crystallization ages for the arc magmatism with abundant Permian-Triassic zircon xenocrysts clustering at ca. 250 Ma. The Permian-Triassic grains show dominantly negative εHf(t) values ranging from ?16.2 to ?6.6, which are similar to those of coeval rocks in Eastern Indochina. Combined with previous paleomagnetic studies, we propose that an Eastern Indochina-derived continental fragment was involved during the formation of arcs in the Cebu and Bohol Islands, which highlights the potential contribution of ancient continental materials in the formation of intra-oceanic arcs. This scenario does not support the previously proposed model that the Cretaceous arc in the Philippine Mobile Belt formed in the northern margin of the proto-Philippine Sea Plate and Australian margin.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35793.1/594151/Contribution-of-an-Eastern-Indochina-derived

Fingerprinting sand from Asian rivers to the deep central South China Sea since the Late Miocene
Licheng Cao; Tao Jiang; Jingke He

Abstract: The complex sedimentary processes from source to sink lead to a substantial fractionation of sediment size and composition. Relatively coarse-grained, continent-derived detritus is rarely transported and deposited in the deep ocean, and the terminus of this sediment routing system is poorly understood. Sandy turbidite deposits within the Upper Miocene?Pleistocene strata drilled in the deep central South China Sea during the International Ocean Discovery Program (IODP) Expedition 349 provide valuable samples for evaluating the evolution of sediment contributions from different Asian landmasses. This study reconstructs this ancient source-to-sink system based on an integration of heavy mineral and detrital zircon analyses (including U-Pb age, trace element, grain size and shape), obtained from IODP sites U1431 and U1432, as well as a zircon age-based mixture modeling of well-defined provenance end-members. The results show several provenance shifts that correspond to more complex and dynamic source-to-sink scenarios than previously envisaged. Certain source areas, like East Vietnam, present a different provenance signature than that of today. Multiple provenances have been mixed and diluted during sediment transport, exhibiting a large regional variability. We interpret that siliciclastic turbidite deposits in the central South China Sea were mainly derived from East Vietnam during the early Late Miocene and Pliocene, and the Pearl River Basin during the late Late Miocene and Pleistocene. Additional, but less significant, contributions from the Red and Mekong river basins and coastal Southeast China are also observed.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35845.1/594152/Fingerprinting-sand-from-Asian-rivers-to-the-deep

Metamorphic P-T-t evolution of amphibolite in the north Hengshan terrane, North China Craton: Insights into the late Paleoproterozoic tectonic processes from initial collision to final exhumation
Jiahui Qian; Changqing Yin; Shun Li; Jian Zhang

Abstract: Amphibolite retrograded from high-pressure (HP) mafic granulite can provide valuable insight into exhumation of deeply buried crust in orogenic belts. In the north Hengshan terrane of the North China Craton, amphibolite occurs as rims of HP mafic granulite block or as smaller homogeneous boudins representing retrograde products of the granulite. Three amphibolite samples were selected. The rocks are mainly composed of hornblende + plagioclase + quartz + biotite + ilmenite with or without garnet pseudomorph consisting of plagioclase + hornblende + ilmenite and symplectite of hornblende + plagioclase ± clinopyroxene. The pseudomorph-, symplectite-bearing sample experienced a post-peak isothermal decompression at >800 °C that was accompanied by breakdown of garnet and clinopyroxene. Isopleths of the maximum An in plagioclase and Ti in hornblende were used to constrain the Tmax stage of ca. 6 kbar/825?850 °C, which was followed by cooling and post-cooling decompression. For the sample showing an "equilibrated" mineral assemblage, a medium-temperature decompression from >6.8 kbar/685 °C to 3.6?4.8 kbar/640?660 °C was inferred. P-T evolution of the north Hengshan terrane is characterized by two discrete (post-peak and post-cooling) decompression processes. Zircon U-Pb dating of amphibolite yields a metamorphic age of 1868 ± 15 Ma, which is interpreted to record the timing of late amphibolization. Synthesized metamorphic P-T-t data in the Hengshan-Wutai area indicate a complicated tectonic evolution that includes an older collisional orogeny at ca. 1.95 Ga and a younger metamorphism at ca. 1.85 Ga. The post-cooling decompression path of the amphibolite may reflect final exhumation of the north Hengshan terrane through the late deformation/metamorphism of the Zhujiafang shear zone.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35810.1/594134/Metamorphic-P-T-t-evolution-of-amphibolite-in-the

Protracted northward drifting of South China during the assembly of Gondwana: Constraints from the spatial-temporal provenance comparison of Neoproterozoic?Cambrian strata
Qiong Chen; Guochun Zhao; Min Sun

Abstract: Neoproterozoic to Paleozoic sedimentation shows systematic temporal-spatial variations within South China, which must be considered in reconstructing geological evolution of South China in response to global plate reorganization from the breakup of Rodinia to the assembly of Gondwana. We use >1000 new U-Pb and Hf isotopic data for detrital zircons from Neoproterozoic?Cambrian strata across the western (i.e., Longmenshan) and eastern (i.e., Wuyishan) margins of South China, coupled with compiled stratigraphic and magmatic information, to constrain change in provenance through time. First-order conclusions are as follows: (1) detrital zircons from the Neoproterozoic strata of the two margins were mainly sourced from the Panxi-Hannan arc and the Jiangnan orogen, signaling a rough self-sufficient sedimentary system; (2) newly identified Cambrian molasse-like sediments in the western margin, in which abundant detrital zircons are 550?500 Ma old with positive εHf(t) values, were mainly derived from the 580?500 Ma Cadomian arc belt along the Iran-Turkey margin; and (3) the Cambrian sediments in the eastern margin document more increased contributions from the Grenvillian-age provinces most possibly in Australia. Such spatial-temporal provenance variations signal the northward drifting of South China, from a position connecting with Iran-Turkey and northern India to that approaching Australia during the late Neoproterozoic?Cambrian period. We highlight that the activity of oblique oceanic-continental convergence accreted Asian terranes onto the northern margin of Gondwana, hence contributing to the ultimate Gondwana architecture under global plate reorganization.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35791.1/594114/Protracted-northward-drifting-of-South-China

The convexity of carbonate hilltops: 36Cl constraints on denudation and chemical weathering rates and implications for hillslope curvature
Matan Ben-Asher; Itai Haviv; Onn Crouvi; Joshua J. Roering; Ari Matmon

Abstract: Carbonate hillslopes are often soil mantled and display a classic convex morphology. In this study we examine controls on carbonate hillslope denudation and morphology using a modified regolith mass balance equation to account for chemical weathering and dust input--two fluxes that are commonly neglected in settings with silicate-dominated bedrock. We utilize seven study sites in the Eastern Mediterranean across a significant gradient in the mean annual rainfall and dust deposition flux. Combining cosmogenic 36Cl-derived hilltop denudation rates with an estimate of the regolith chemical depletion and the quantified fraction of dust in the regolith we predict hilltop curvature and compare our predictions with observations based on high-resolution airborne LiDAR (light detection and ranging). Denudation rates vary from 5 to 210 mm/k.y. and increase with mean annual rainfall. Less resistant carbonates (chalk) experience faster denudation rates relative to more resistant dolo-limestone and are less prone to chemical weathering. Soil production exhibits a humped dependency on soil thickness. The observed hilltop curvature varies as a function of rainfall and dust flux with a minimum at sub-humid sites. While trends in hilltop convexity are often solely attributed to variations in erosion rate, our results illustrate the additional effects of dust production and chemical depletion. Our mass balance model implies that drier sites in the south probably experienced a more intricate history of regolith production due to dust flux fluctuations. Thus, by incorporating dust flux and chemical weathering to the classic hillslope evolution model we are able to identify a complex relation between hilltop curvature, soil production, and climate.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35658.1/594041/The-convexity-of-carbonate-hilltops-36Cl

Surface slip distributions and geometric complexity of intraplate reverse-faulting earthquakes
Haibin Yang; Mark Quigley; Tamarah King

Abstract: Earthquake ground surface ruptures provide insights into faulting mechanics and inform seismic hazard analyses. We analyze surface ruptures for 11 historical (1968?2018) moment magnitude (Mw) 4.7?6.6 reverse earthquakes in Australia using statistical techniques and compare their characteristics with magnetic, gravity, and stress trajectory data sets. Of the total combined (summative) length of all surface ruptures (?148 km), 133 km (90%) to 145 km (98%) align with the geophysical structure in the host basement rocks. Surface rupture length (SRL), maximum displacement (MD), and probability of surface rupture at a specified Mw are high compared with equivalent Mw earthquakes globally. This is attributed to (1) a steep cratonic crustal strength gradient at shallow depths, promoting shallow hypocenters (?1?6 km) and limiting downdip rupture widths (?1?8.5 km), and (2) favorably aligned crustal anisotropies (e.g., bedrock foliations, faults, fault intersections) that enhanced lateral rupture propagation and/or surface displacements. Combined (modeled and observed) MDs are in the middle third of the SRL with 68% probability and either the ?33rd or ?66th percentiles of SRL with 16% probability. MD occurrs proximate to or directly within zones of enhanced fault geometric complexity (as evidenced from surface ruptures) in 8 of 11 earthquakes (73%). MD is approximated by 3.3 ± 1.6 (1σ) × AD (average displacement). S-transform analyses indicates that high-frequency slip maxima also coincide with fault geometric complexities, consistent with stress amplifications and enhanced slip variability due to geometric and kinematic interactions with neighboring faults. Rupture slip taper angles exhibite large variations (?90% to +380% with respect to the mean value) toward rupture termini and are steepest where ruptures terminate at obliquely oriented magnetic lineaments and/or lithology changes. Incremental slip approximates AD between the 10th and 90th percentiles of the SRL. The average static stress drop of the studied earthquakes is 4.8 ± 2.8 MPa. A surface rupture classification scheme for cratonic stable regions is presented to describe the prevailing characteristics of intraplate earthquakes across diverse crustal structural-geophysical settings. New scaling relationships and suggestions for logic tree weights are provided to enhance probabilistic fault displacement hazard analyses for bedrock-dominated intraplate continental regions.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35809.1/594001/Surface-slip-distributions-and-geometric

Eroding Cascadia--Sediment and solute transport and landscape denudation in western Oregon and northwestern California
Jim E. O'Connor; Joseph F. Mangano; Daniel R. Wise; Joshua R. Roering

Abstract: Riverine measurements of sediment and solute transport give empirical basin-scale estimates of bed-load, suspended-sediment, and silicate-solute fluxes for 100,000 km2 of northwestern California and western Oregon. This spatially explicit sediment budget shows the multifaceted control of geology and physiography on the rates and processes of fluvial denudation. Bed-load transport is greatest for steep basins, particularly in areas underlain by the accreted Klamath terrane. Bed-load flux commonly decreases downstream as clasts convert to suspended load by breakage and attrition, particularly for softer rock types. Suspended load correlates strongly with lithology, basin slope, precipitation, and wildfire disturbance. It is highest in steep regions of soft rocks, and our estimates suggest that much of the suspended load is derived from bed-load comminution. Dissolution, measured by basin-scale silicate-solute yield, constitutes a third of regional landscape denudation. Solute yield correlates with precipitation and is proportionally greatest in low-gradient and wet basins and for high parts of the Cascade Range, where undissected Quaternary volcanic rocks soak in 2?3 m of annual precipitation. Combined, these estimates provide basin-scale erosion rates ranging from ?50 t ? km?2 ? yr?1 (approximately equivalent to 0.02 mm ? yr?1) for low-gradient basins such as the Willamette River to ?500 t ? km?2 ? yr?1 (?0.2 mm ? yr?1) for steep coastal drainages. The denudation rates determined here from modern measurements are less than those estimated by longer-term geologic assessments, suggesting episodic disturbances such as fire, flood, seismic shaking, and climate change significantly add to long-term landscape denudation.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35710.1/593893/Eroding-Cascadia-Sediment-and-solute-transport-and

Hydrothermal formation of iron-oxyhydroxide chimney mounds in a shallow semi-enclosed bay at Satsuma Iwo-Jima Island, Kagoshima, Japan
Shoichi Kiyokawa; Takashi Kuratomi; Tatsuhiko Hoshino; Shusaku Goto; Minoru Ikehara

Abstract: Hydrothermal iron-oxyhydroxide chimney mounds (iron mounds) have been discovered in a fishing port in Nagahama Bay, located on the southwest coast of Satsuma Iwo-Jima Island, south of Kyushu Island, Japan. In the fishing port, uncovered ?1.0-m-high iron mounds in shallow waters formed under relatively calm conditions. Typically, the fishing port has orange-colored turbid waters that mix with outer ocean waters during high tide. Colloidal iron-oxyhydroxides form due to the oxidation of ferrous iron in hydrothermal waters (pH = 5.5; temperature = 55 °C) as they mix with seawater. The mounds are made of two types of material: hard, dark brown?orange, high-density material; and soft, brownish orange?yellow, low-density material. Computed tomography scans of the harder iron mound material revealed a cabbage-like structure consisting of micropipe structures with diameters of 2?5 mm. These micropipes have relatively hard walls made of iron oxyhydroxides (FeOH) and are identified as discharge pipes. Nucleic acid staining genetic sequencing and scanning electron microscope observations suggest that the mounds formed mainly from bacterial stalks with high concentrations of FeOH colloidal matter. In the harder parts of the mounds, these "fat stalks," which contain oxyhydroxide colloidal aggregates, are entwined and concentrated. The softer material contains twisted stalk-like structures, which are coated with FeOH colloidal particles. Deoxyribonucleic acid (DNA) examination of the iron mounds revealed the presence of iron-oxidizing bacteria, especially at the mound surface. We estimate that the iron mounds accumulated at a rate of ?1700 tons/1000 m2/yr. This is an order of magnitude higher than the rate of FeOH sedimentation via chemical precipitation of FeOH colloids within the fishing port. This suggests that biogenic activity, resulting in the production of entwined FeOH stalks, leads to the rapid accumulation of FeOH beds and that biogenic activity within the water mass rich in FeOH colloids is an efficient means of generating thick iron-rich sedimentary sequences. As such, we propose that some ancient iron formations may have also formed through the biogenic production of FeOH stalks rather than solely through chemical sedimentation in a water mass rich in FeOH colloids. It appears that these rapidly forming biogenic FeOH iron mounds, distributed over a wide area of ocean floor, are also relatively protected from erosion and diagenetic alteration (reduction). Previous studies have reported that ancient iron formations were commonly deposited in deeper environments via direct iron oxidation from the water column in a ferruginous ocean. However, there are several hydrothermal vent inflows preserved with FeOH that would have formed appropriate redox boundary conditions in an otherwise anoxic ocean. Under these conditions, iron mound mat-type sedimentary deposits might have formed and been well preserved and affected by early diagenesis where higher heat flow occurred in the Archean ocean. The FeOH mounds in Nagahama Bay provide an example of the iron formation sedimentary environment and important information for estimating the past depositional state of iron formations.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35782.1/593894/Hydrothermal-formation-of-iron-oxyhydroxide

Textural and geochemical window into the IDDP-1 rhyolitic melt, Krafla, Iceland, and its reaction to drilling
E. Saubin; B. Kennedy; H. Tuffen; A.R.L. Nichols; M. Villeneuve ...

Abstract: The unexpected intersection of rhyolitic magma and retrieval of quenched glass particles at the Iceland Deep Drilling Project-1 geothermal well in 2009 at Krafla, Iceland, provide unprecedented opportunities to characterize the genesis, storage, and behavior of subsurface silicic magma. In this study, we analyzed the complete time series of glass particles retrieved after magma was intersected, in terms of distribution, chemistry, and vesicle textures. Detailed analysis of the particles revealed them to represent bimodal rhyolitic magma compositions and textures. Early-retrieved clear vesicular glass has higher SiO2, crystal, and vesicle contents than later-retrieved dense brown glass. The vesicle size and distribution of the brown glass also reveal several vesicle populations. The glass particles vary in δD from ?120‰ to ?80‰ and have dissolved water contents spanning 1.3?2 wt%, although the majority of glass particles exhibit a narrower range. Vesicular textures indicate that volatile overpressure release predominantly occurred prior to late-stage magma ascent, and we infer that vesiculation occurred in response to drilling-induced decompression. The textures and chemistry of the rhyolitic glasses are consistent with variable partial melting of host felsite. The drilling recovery sequence indicates that the clear magma (lower degree partial melt) overlays the brown magma (higher degree partial melt). The isotopes and water species support high temperature hydration of these partial melts by a mixed meteoric and magmatic composition fluid. The textural evidence for partial melting and lack of crystallization imply that magma production is ongoing, and the growing magma body thus has a high potential for geothermal energy extraction. In summary, transfer of heat and fluids into felsite triggered variable degrees of felsite partial melting and produced a hydrated rhyolite magma with chemical and textural heterogeneities that were then enhanced by drilling perturbations. Such partial melting could occur extensively in the crust above magma chambers, where complex intrusive systems can form and supply the heat and fluids required to re-melt the host rock. Our findings emphasize the need for higher resolution geophysical monitoring of restless calderas both for hazard assessment and geothermal prospecting. We also provide insight into how shallow silicic magma reacts to drilling, which could be key to future exploration of the use of magma bodies in geothermal energy.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35598.1/593788/Textural-and-geochemical-window-into-the-IDDP-1

Intracontinental extension and geodynamic evolution of the Paleoproterozoic Jiao-Liao-Ji belt, North China craton: Insights from coeval A-type granitic and mafic magmatism in eastern Liaoning Province
Jian-Hui Liu; Xiang-Jian Wang; Hui Chen

Abstract: To better understand the origin and tectonic evolution of the Paleoproterozoic Jiao-Liao-Ji belt, North China craton, which have long been debated, we have conducted whole-rock geochemical and zircon U-Pb and Hf isotope analyses on Paleoproterozoic monzo(syeno)granitic gneisses and metamafic rocks from eastern Liaoning Province. The results indicate that these monzo(syeno)granitic gneisses and metamafic rocks formed concurrently at ca. 2.2?2.1 Ga. The monzo(syeno)granitic gneisses show geochemical features of A-type granites and were derived from dehydration melting of Archean tonalite-trondhjemite-granodiorite (TTG) with minor involvement of coeval mantle-derived magma in an extensional setting. The metamafic rocks are geochemically similar to mid-ocean-ridge basalt; they were generated by partial melting of isotope-depleted asthenospheric mantle in an intracontinental extensional setting and experienced crustal and continental lithospheric mantle contamination and fractional crystallization. Based on this study and published geological evidence, we propose the following tectonic model for the origin and geodynamic evolution of the Jiao-Liao-Ji belt: (1) Generation of high-density eclogitized lower crust accompanied by formation of voluminous Archean TTGs in the Eastern block; (2) intracontinental extension driven by upwelling of an asthenospheric hotspot along the Jiao-Liao-Ji belt in period of 2.20?2.0 Ga; (3) convergent orogenic processes between the Longgang block and Nangrim block governed by gravity-driven subduction of high-density eclogitized lower crust at ca. 1.95?1.85 Ga; and (4) postorogenic extension caused by delamination of the orogenic root and subsequent hot asthenospheric upwelling. This tectonic model can well explain the origin and geodynamic evolution of the Paleoproterozoic Jiao-Liao-Ji belt.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35819.1/593789/Intracontinental-extension-and-geodynamic

High-Ca boninitic melt inclusions in lavas of the Troodos ophiolite and a reappraisal of genetic relationships between different lava types
Wen-Jun Hu; Mei-Fu Zhou; John Malpas; Zhong-Yuan Ren

Abstract: Boninites in many supra-subduction zone ophiolites are thought to mark the early stage of subduction. The Troodos ophiolite in Cyprus contains a variety of volcanic rocks including the lower pillow lavas and the boninite-bearing upper pillow lavas (UPL). Here we present major, trace element and Pb isotope data for melt inclusions in olivine from the UPL on the northern flank of the Troodos ophiolite. Melt inclusions hosted by high-Mg (Fo = 89.4?93.5) olivine grains have typical high-Ca boninitic compositions with high MgO (11.2?18.4 wt%) and SiO2 (51.2?55.0 wt%) and low TiO2 (0.2?0.6 wt%) contents, in line with the existence of boninites in the northern part of the ophiolite. The melt inclusions have trace element compositions similar to the Troodos boninitic lavas and can be regarded as representing the parental magma of the boninites. The boninitic magmas were derived from high-degrees of partial melting of a refractory source at 1400 °C and 1.5 GPa based on thermobarometers and phase equilibria. The melt inclusions have significantly variable Pb isotopic compositions (208Pb/206Pb = 2.059?2.122; 207Pb/206Pb = 0.828?0.862) and are enriched in fluid-mobile trace elements (e.g., U, Sr, and Pb), indicating that the refractory source was metasomatized by slab fluids. In comparison, recalculation of literature data suggests that the lower pillow lavas were derived from a less refractory and shallower source. We propose a subduction initiation model in which melting of two unique sources was needed to form the chemostratigraphy of lavas in the Troodos ophiolite.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35717.1/593793/High-Ca-boninitic-melt-inclusions-in-lavas-of-the

Structural geometry and kinematics of thrust belts between the Dabashan and eastern Sichuan Basin, South China block: Constraints from (U-Th)/He dating and seismic data
Guo Lu; Chuanxin Li; Wenzheng Li; Shang Deng; Jianyong Zhang

Abstract: The relationship between the North and South China blocks, particularly their spatial-temporal framework and evolutionary history, has been widely debated. We conducted a comprehensive study of the structural geometry and kinematics of the thrust belts in the intersection zone between the Dabashan and eastern Sichuan Basin based on seismic data, drilling data, field investigation data, and zircon and apatite (U-Th)/He thermochronology data. These data sets provide important insights into the relationship between the North and South China blocks during the post-orogenic process. Due to the detachments, the strata of the eastern Sichuan Basin can be divided into four structural intervals characterized by duplex structures and fault-related fold structures. Balanced restoration indicates the vertical differences are represented by the shortening ratio of the upper structural interval of ?6%, that of the middle ?10%, and that of the lower ?7%. Besides, the shortening ratios indicate an increasing tendency of the deformation intensity from the west to the east. The (U-Th)/He dating results suggest two age ranges, i.e., from 180 Ma to 130 Ma and from 50 Ma to 20 Ma, respectively. These age data sets also imply a younger tendency westward. The intersection zone may have experienced the following stages since the late Mesozoic era: (1) the stable continental sedimentation stage from the Late Triassic to the Late Jurassic epochs; (2) the continuous thrust stage from the Late Jurassic to the early Paleogene epochs, which is associated with the subduction of the Paleo-Pacific Ocean; and (3) the uplift and denudation stage as a whole caused by the uplift of the Tibetan Plateau since the Paleogene period.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35781.1/593776/Structural-geometry-and-kinematics-of-thrust-belts

Timing of closure of the Meso-Tethys Ocean: Constraints from remnants of a 141?135 Ma ocean island within the Bangong?Nujiang Suture Zone, Tibetan Plateau
Jian-Jun Fan; Yaoling Niu; Yi-Ming Liu; Yu-Jie Hao

Abstract: The relationship between the North and South China blocks, particularly their spatial-temporal framework and evolutionary history, has been widely debated. We conducted a comprehensive study of the structural geometry and kinematics of the thrust belts in the intersection zone between the Dabashan and eastern Sichuan Basin based on seismic data, drilling data, field investigation data, and zircon and apatite (U-Th)/He thermochronology data. These data sets provide important insights into the relationship between the North and South China blocks during the post-orogenic process. Due to the detachments, the strata of the eastern Sichuan Basin can be divided into four structural intervals characterized by duplex structures and fault-related fold structures. Balanced restoration indicates the vertical differences are represented by the shortening ratio of the upper structural interval of ?6%, that of the middle ?10%, and that of the lower ?7%. Besides, the shortening ratios indicate an increasing tendency of the deformation intensity from the west to the east. The (U-Th)/He dating results suggest two age ranges, i.e., from 180 Ma to 130 Ma and from 50 Ma to 20 Ma, respectively. These age data sets also imply a younger tendency westward. The intersection zone may have experienced the following stages since the late Mesozoic era: (1) the stable continental sedimentation stage from the Late Triassic to the Late Jurassic epochs; (2) the continuous thrust stage from the Late Jurassic to the early Paleogene epochs, which is associated with the subduction of the Paleo-Pacific Ocean; and (3) the uplift and denudation stage as a whole caused by the uplift of the Tibetan Plateau since the Paleogene period.

View article: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B35781.1/593776/Structural-geometry-and-kinematics-of-thrust-belts

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In a review of national firearm data spanning more than 20 years, researchers at Oregon Health & Science University have identified alarming trends regarding increasing rates of firearm-related deaths among some of America's youngest residents.

According to lead researcher Archie Bleyer, M.D., the rate of unintentional firearm deaths in children ages 1 - 4 increased exponentially at an average annual percent of 4.9 between 1999 and 2018, with the greatest impact among non-Hispanic Black and White children. This rate is more than eight times higher than any other highly developed country worldwide.

"What is perhaps most distressing about these findings, is that nearly 90% of these instances took place in or near the victims' home, and 100% of the events were preventable," says Bleyer, a clinical research professor in the Department of Radiation Medicine, OHSU Knight Cancer Institute, OHSU School of Medicine.

Using data from the Centers for Disease Control and Prevention's National Violent Death Reporting System, Bleyer and team determined that the majority of accidental firearm-related deaths within this age range between 2015 - 2017 were due to injuries caused by handguns. This finding directly correlates with the concurrent rate of firearm background checks and handgun permits issued in the United States during that timeframe.

The Federal Bureau of Investigation's National Instant Criminal Background Check System indicates that nearly 39,700,000 firearm background checks were initiated in 2020, an approximate 40% increase over 2019. Since March 2020, when the COVID-19 pandemic took hold in the U.S., both the purchase of firearms and unintentional firearm injury and death in 1- to 6-year-olds has increased.

"The continuing pandemic, as well as strong civil unrest, are of great concern for an even larger increase in potential firearm access and associated deaths in young children," says Bleyer. "Increased safety training and intervention, particularly for first-time gun owners, is imperative to ensure a decline in the rate of such unfortunate incidents."

A 2018 study published in the journal Pediatrics concludes that millions of U.S. children live in homes in which firearms are left loaded, unlocked or both.

"Many families who own firearms do not think about the danger they can pose to children. However, the reality is that kids are curious by nature and are not injury proof," says Ben Hoffman, M.D., medical director of the Tom Sargent Safety Center at OHSU Doernbecher Children's Hospital and professor of pediatrics in the OHSU School of Medicine. "Parents and caregivers need to work to eliminate hazards and threats from the places where kids and youth spend time and have access. Placing dangerous items in a drawer or on high shelf isn't enough. Firearms - as well as medications, household cleaners and other toxic substances -- must be safely locked away to help mitigate preventable disaster."

A full report of the data review conducted by the OHSU team recently published in the Journal of the National Medical Association.

You can't have your cake and eat it too, as the saying goes. But what if you could save your slice while enjoying the benefits at the same time? New research suggests this is possible when it comes to marine reserves.

Marine protected areas (MPAs) are among the best conservation tools at our disposal today. However, by their very nature, these reserves take away fishing grounds, which can make them unattractive to commercial fishermen. Scientists and resource managers often promote MPAs as beneficial for the fishery. In theory, they provide a refuge for stocks to rebuild and spill over into nearby waters, leading to improved catch rates.

"And yet, there's a lot of skepticism about that because there aren't many instances where anyone's ever shown that to be true," said Dan Reed(link is external), a research biologist at UC Santa Barbara's Marine Science Institute.

Most of the work so far has documented the buildup of species populations within reserves and the subsequent spillover. "What hasn't been documented is how that actually affects the catch," he continued. Namely, whether any increase in catch from spillover actually compensates for the loss of fishing grounds.

Reed and his colleague Professor Hunter Lenihan(link is external), a professor at UCSB's Bren School of Environmental Science & Management, along with other researchers at UC Santa Barbara and the California Department of Fish and Wildlife, sought to determine to what extent the spillover effect compensated for the fishing grounds incorporated into marine reserves. To this end, they leveraged catch reports from lobster fishermen as well as scientific surveys. Their results, published in Scientific Reports(link is external), affirm the benefits that MPAs confer to fisheries and ecosystems.

"The key question is what is the net effect of the reserves on the fishery?" proposed lead author Lenihan, a fisheries ecologist. "If you take away a certain amount of territory, do you make up for it by this increase in catch through spillover?"

"What we found is that you not only make up for the lost area, but actually enhance the fishery," replied Reed.

The team compared lobster populations and catch records from waters off the coast of Santa Barbara and Goleta. From 2012 through 2018, divers conducted surveys of the size and abundance of lobsters at five sites studied by the Santa Barbara Coastal Long Term Ecological Research program (SBC LTER), which is part of the National Science Foundation's LTER network. Three of these reefs have always been open to fishing, while two of them (Isla Vista and Naples reefs) were incorporated into two marine reserves in 2012.

The researchers also obtained data for commercial landings and fishing effort -- measured in the number of traps pulled -- from the California Department of Fish and Wildlife, which manages the state's fisheries. Records from six years before and after the establishment of the two MPAs gave the scientists a sizable window to examine the impact that the reserves had on the lobster catch. The department divides the coast into rectangular fishing blocks, and these became the spatial units the researchers used in the study.

The team observed that the number and overall biomass of lobsters increased in and around the marine reserves once fishing was prohibited. This suggested that lobsters were indeed proliferating inside the reserves and spilling out into surrounding areas, just as predicted by the theory.

They also found that annual lobster landings more than doubled in the fishing block with the two MPAs during the six years after their establishment despite the 35% reduction in fishing area in that block. In contrast, the annual catch in blocks without MPAs remained relatively unchanged over that timespan.

"This study is one of the first to quantify and document that the establishment of marine reserve actually enhanced catch despite reducing the area that fishermen could actually fish," said Reed.

Records indicate that a roughly 225% increase in catch near marine reserves was accompanied by a 250% increase in fishing activity; however, the researchers note that this isn't merely a case of laying more traps and catching more lobsters. The increased effort was targeted largely near the borders of the reserves as fishermen "fished the line" to target lobsters that spilled over from the reserves into fishable areas. "Without spillover from a reserve, increasing fishing effort is much less likely to result in increased catch," said Reed.

"Our data suggest that in the case of lobster the MPAs have the potential to lead to a higher sustainable catch," he concluded.

Lenihan and Reed were quick to point out that studies like this are possible largely thanks to projects like the SBC LTER. The sustained funding from the NSF enables scientists to curate rich timeseries datasets they can use to investigate questions that involve relatively long timespans.

The researchers at the SBC LTER have worked with the local fishing communities for years in an effort to understand the effects of reserves. Their collaboration with the California Lobster and Trap Fishermen's Association has been particularly fruitful, Lenihan said. Lobstermen Chris Miller, Sam Shrout and Chris Voss dedicated substantial time to train Bren School doctoral students Matt Kay, in 2006, and Sean Fitzgerald, in 2018, to trap lobsters like professionals, thus assuring collection of excellent fisheries data. In addition, scientists hopped aboard commercial fishing boats to trap lobsters with the fleet.

They've also relied on fishermen for data. After tagging some 17,000 lobsters with researchers' names and phone number, the scientists waited for fishermen to report where the lobsters were caught. This provided insight into the animals' movements that would not have been possible without such a collaboration.

Lobstermen also appear to be benefiting from this relationship. Reserves seem to have increased landings in the northern extent of the fishery much more than in the south. Lenihan and Reed suspect this is because the fishermen in the north have been working with the scientists, giving them access to insights that their southern counterparts don't have.

"We learn from them; they learn from us," Lenihan said.

"Collaboration between researchers and fishermen not only serves their interests, but it can also really benefit the conservation value of the MPAs and the resource agencies charged with managing them," added Reed.

Cooperation between scientists, fishermen and resource managers leads to better information, more transparency and more trust, Lenihan explained. Ultimately, that improves science, management, conservation and fishing.

The researchers of the Institute for Atmospheric and Earth system research at the University of Helsinki have investigated how atmospheric particles are formed in the Arctic. Until recent studies, the molecular processes of particle formation in the high Arctic remained a mystery.

During their expeditions to the Arctic, the scientists collected measurements for 12 months in total. The results of the extensive research project were recently published in the Geophysical Research Letters journal.

The researchers discovered that atmospheric vapors, particles, and cloud formation have clear differences within various Arctic environments. The study clarifies how Arctic warming and sea ice loss strengthens processes where different vapors are emitted to the atmosphere. The thinning of sea ice enables more iodine emissions while broader open waters enable more emissions of sulfur-containing vapors.

Higher concentrations of vapors result in a higher amount of particles. This on the other hand will lead to more clouds, which can - depending on the season and location - either slow down or accelerate the Arctic warming. Detailed knowledge of these processes is crucial in order to understand the consequences of global warming.

"Our observations are contributing to further understanding of what happens in the Arctic atmosphere due to warming. In general, atmospheric particles and clouds play an important role in regulating the atmosphere's temperature, and any changing behavior of these has consequences on Arctic warming. Arctic areas are especially sensitive to changes in cloudiness and albedo", says Lisa Beck, a doctoral student at the Institute for Atmospheric and Earth System Research (INAR).

More in­for­ma­tion about the fu­ture of melt­ing sea ice

The researchers conducted measurements in Northern Greenland at Villum research station and in Svalbard at Ny-Ålesund for 6-months at each station. While both sites are located at similar latitudes, about 1000 km south of the North Pole, their environments are very different. Villum-station is surrounded by sea ice all year round, while the warm sea currents cause the sea around Ny-Ålesund to remain open.

In Northern Greenland the researchers discovered that in the spring after the Polar night the microalgae below the sea ice started to emit iodine compounds to the atmosphere. As the spring continues, the thinning sea ice leads to the emission of even more iodine compounds. These compounds form molecular clusters that can grow into bigger particles.

In Svalbard, surrounded by open waters, the observations showed how sulfur-compounds emitted by phytoplankton could form a large amount of particles that could grow fast, and can even form cloud droplets. In the studies of Svalbard also organic compounds were detected.

The large amount and role of organic compounds in the Arctic particle formation surprised the researchers.

"We did not expect to observe many organic vapors in the cold and bare Arctic environment as they have been mainly seen in areas covered by forests. We are planning to continue the studies in Svalbard to figure out what these organic compounds are and where they are coming from", Beck says.

The particle concentrations in Svalbard were clearly higher than the ones measured in Northern-Greenland.

"Currently, the Arctic sea ice is melting fast. As a result, we can assume that the processes observed in Svalbard will be more common in the Arctic areas that will be liberated from sea ice", Beck says.

Beyond the ski slopes, one of the most iconic symbols of the Alps are the alpine flowers. These plants are not only beautiful -- they are also used in liqueurs and medicines, and they form the foundation of the local food chains. But a recent study in Frontiers in Ecology and Evolution shows that, although plant diversity may initially increase with glacier retreat, many of these species may soon become endangered.

"Our results indicate that plant diversity will ultimately decrease once the glaciers disappear -- and up to 22% of the species we analyzed may locally disappear or even go extinct once the glaciers are gone," says lead author Dr Gianalberto Losapio of Stanford University in the USA. "We show that 'not all species are equal before global warming' and that there are some species benefiting from global warming -- the so- called 'winners,' -- while others -- 'the losers' -- will suffer."

As glaciers retreat, they expose newly available land for plants to grow, but this also changes the inhabitability and diversity of the downstream ecosystems. Losapio and his collaborators used geological records to reconstruct the positions of four glaciers in the Italian Alps, allowing them to approximate the age of downstream communities.

By combining this information with their own contemporary survey of 117 plant species and analyses of local environmental conditions, they used computational models to calculate how the plant distribution had changed over the past five millennia. These models also forecasted the effects of future glacier retreat.

Their findings indicated shifts in the interactions within plant communities, with competitive species becoming more prevalent in the long term. Although some cooperative species, such as Artemisia genipi, were the first to colonize terrain, their populations would decline within only 100 years.

Although there is some uncertainty in the calculated dates of the older communities, the researchers received similar estimates using alternative methods as well. These findings also do not explore the role of evolution, and it may be possible that some species have adapted to changing conditions in the past. But the unprecedented rate of current glacier retreat makes it unlikely that there is time for such adaptations now.

This study contributes to the United Nations' Convention on Biological Diversity and the UN Strategic Plan for Biodiversity 2011-2020. These objectives focus on understanding the mechanisms of biodiversity loss and increasing the conservation and sustainable management of threatened species and ecosystems.

"Plants are the primary producers at the basis of the food web that sustains our lives and economies, and biodiversity is key to healthy ecosystems -- biodiversity also represents an inestimable cultural value that needs to be properly supported," says Losapio. "Our study, with its results and innovative approach, may help conservationists, natural park managers and practitioners to mitigate and anticipate the consequences of anthropogenic impact on Earth's ecosystems."

Methane (CH4) is the second most important greenhouse gas after carbon dioxide (CO2). Its concentration in the atmosphere has increased more than twice since the preindustrial era due to enhanced emissions from human activities. While the global warming potential of CH4 is 86 times as large as that of CO2 over 20 years, it stays in the atmosphere for about 10 years, much shorter than more than centuries of CO2. It is therefore expected that emission controlling of CH4 can benefit for relatively short time period toward the Paris Agreement target to limit the global warming well below 2 degrees.

A study by an international team, published in Journal of Meteorological Society of Japan, provides a robust set of explanations about the processes and emission sectors that led to the hitherto unexplained behaviors of CH4 in the atmosphere. The growth rate (annual increase) of CH4 in the atmosphere varied dramatically over the past 30 years with three distinct phases, namely, the slowed (1988-1998), quasi-stationary (1999-2006) and renewed (2007-2016) growth periods (Fig. 1). No scientific consensus is however reached on the causes of such CH4 growth rate variability. The team, led by Naveen Chandra of National Institute for Environmental Studies, combined analyses of emission inventories, inverse modeling with an atmospheric chemistry-transport model, the global surface/aircraft/satellite observations to address the important problem.

They show that reductions in emissions from Europe and Russia since 1988, particularly from oil-gas exploitation and enteric fermentation, led to the slowed CH4 growth rates in the 1990s (Fig. 2), where reduced emissions from natural wetlands due the effects of Mount Pinatubo eruption and frequent El Niño also played roles. This period was followed by the quasi-stationary state of CH4 growth in the early 2000s. CH4 resumed growth from 2007, which were attributed to increases in emissions from coal mining mainly in China and intensification of livestock (ruminant) farming and waste management in Tropical South America, North-central Africa, South and Southeast Asia. While the emission increase from coal mining in China has stalled in the post-2010 period, the emissions from oil and gas sector from North America has increased (Fig. 2). There is no evidence of emission enhancement due to climate warming, including the boreal regions, during our analysis period.

These findings highlight key sectors (energy, livestock and waste) for effective emission reduction strategies toward climate change mitigation. Tracking the location and source type is critically important for developing mitigation strategies and the implementation the Paris Agreement. The study also underlines need of more atmospheric observations with space and time density higher than the present.