Earth

Ammonia has been widely used for agricultural fertilizers and industrial productions. Additionally, NH3 is expected to serve as next-generation green energy carriers due to its high energy density, low liquefying pressure, small air-fuel ratio and no carbon dioxide emission. At present, NH3 is mainly manufactured through the conventional Haber-Bosch process, which is energy-intensive and releases ~1.5% of global CO2 into the atmosphere. During the past years, electrocatalysis and photo(electro)catalysis of nitrogen gas and water into NH3 at ambient conditions have attracted great attention, but the Faradaic efficiency is greatly hampered by the high dissociation energy of N?N bonds (941 kJ mol-1) and the competitive reaction of H2 evolution. Thus, developing a new route for the ammonia synthesis under mild conditions is urgently desired.

As we all known, excessive nitrates (NO3-) exist in surface and underground water due to the overuse of nitrogen-based fertilizers and the discharge of industrial and domestic sewages, threating the human health. Considering that the dissociation energy of N-O bonds in nitrates is only 204 kJ mol-1 and ammonia can be easily reclaimed from its aqueous solution, it is of great interest to use nitrate contaminants as nitrogen source and water as hydrogen source for the electrochemical synthesis of high value-added ammonia. However, the competitive reaction of H2 generation and the complex eight-electron reduction process retard the FE and selectivity of ammonia during electrocatalytic nitrate reduction reactions. Thus, elaborate design and construction of efficient electrocatalysts is critical.

Very recently, Yu's research group in Tianjin University fabricated Co/CoO nanosheet arrays (Co/CoO NSAs), in which electron-deficient Co was constructed by the rectification effect of the Schottky contact between the metallic Co and semiconducting CoO. The heterostructured Co/CoO NSAs with electron-deficient Co exhibited excellent performances for the electrochemical reduction of nitrates to ammonia: 93.8% of Faraday efficiency and 91.2% of selectivity, which were much higher than that of the Co NSAs. 15N isotope labeling experiments proved that the produced ammonia originating from the nitrate electroreduction and the product was quantified with 1H NMR spectra. In-situ electrochemical tests were conducted to capture the intermediates and speculate the reaction path. Theoretical calculations revealed that the electrons transferred from Co to CoO at the Co/CoO interface, thus leading to the electron-deficient Co, can effectively inhibit both the competitive reaction of hydrogen evolution and the formation of by-products in the reduction process, thereby improving the Faraday efficiency and selectivity. This work offers a facile strategy to construct efficient electrocatalysts for ammonia synthesis from nitrate reduction powered by renewable electricity.

To elucidate the timing, location and geodynamic models of the India-Asia collision, Yuan and colleagues conducted paleomagnetic and rock magnetic analyses on two key successions that were deposited on the distal northern part of the Indian passive margin (Tethyan Himalaya terrane), where Upper Cretaceous oceanic red beds (CORBs) of the Chuangde Formation are exposed in the Cailangba A and B sections of the Gyangze area, and Upper Cretaceous to Paleocene red siliceous shales of the lower Sangdanlin Formation are exposed in the Sangdanlin and Mubala sections of the Saga area. The lower Sangdanlin Formation contains the first Asian detritus, and thus determines the collision age.

Paleomagnetic and rock magnetic analyses reveal that these rocks comprise i) secondary magnetic signals carried by chemical hematite and ii) primary magnetic signals of dual polarities carried by detrital hematite. These results indicate that the Tethyan Himalaya terrane was situated at a paleolatitude of 19.4° ± 1.8°S during the late Cretaceous (76.2-74.0 Ma) and moved rapidly northward to reach a paleolatitude of 13.7° ± 2.5°N in the mid-Paleocene (62.5-59.2 Ma). The late Cretaceous results show that at ~75 Ma the Tethyan Himalaya terrane was still significantly separated from the Lhasa terrane by ~3600 km.

The new paleomagnetic data sets imply that the Tethyan Himalaya terrane rifted from India after ~75 Ma, generating the North India Sea. This study further documents a new two-stage continental collision. The northward drifting Tethyan Himalaya terrane collided with Asia at ~61 Ma, and then amalgamated with India with a diachronously closing North India Sea between ~53 Ma and ~48 Ma. This new scenario matches the history of India-Asia convergence rates and reconciles multiple lines of geologic evidence for the India-Asia collision.

This new two-stage collision hypothesis between India and Asia provides crucial constraints for continental collision dynamics, the uplift and deformation history of the Tibetan Plateau, and paleogeography and biodiversity patterns in Asia. Furthermore, the new findings provide key boundary conditions for climate models linking Himalaya-Tibetan orogenesis with global climate change.

In an aging society, various studies are being conducted to explore the relationship between active oxygen and aging-related diseases such as cancer, chronic inflammatory diseases, and metabolic syndrome.

A research group at the Institute of Medical Science, The University of Tokyo in Japan, led by Professor Mutsuhiro Takekawa, has uncovered a new mechanism that elicits a cellular response by detecting oxidative stress in the human body. MTK1 SAPKKK functions(*1) is identified as a new human oxidative stress sensor that senses excess active oxygen in the body and transmits that information to cells, leading to cell death and inflammatory cytokine production. The results of this research were published in Science Advances on June 24, 2020.

MTK1 SAPKKK perceives the cellular redox state and transduces it into SAPK signaling

Living organisms obtain the energy necessary for life activities by oxygen respiration. However, it is known that reactive oxygen species are generated in the human body as a by-product in the process.

Overproduction of active oxygen causes damage to cells and causes various diseases such as aging, cancer, chronic inflammatory diseases (rheumatoid arthritis, etc.), metabolic syndrome, and neurodegenerative diseases. Therefore, it is thought that the human body is equipped with a mechanism for sensing and appropriately responding to the oxidative stress state caused by overproduction of active oxygen. However, the detailed mechanism was unknown.

Cells respond to oxidative stress by inducing intracellular signaling, including the stress-activated p38 and JNK MAPK (SAPK) pathways?*2?, but the underlying mechanisms remain unclear. The research team reports that MTK1 SAPKKK functions as an oxidative stress sensor that perceives the cellular redox state and transduces it into SAPK signaling.

Following oxidative stress, MTK1 is rapidly oxidized and subsequently gradually reduced at evolutionarily conserved cysteine residues. These coupled oxidation-reduction modifications of MTK1 elicit its catalytic activity.

Gene knockout experiments showed that oxidative stress-induced SAPK signaling is mediated by coordinated activation of the two SAPKKKs, MTK1 and ASK1, which have different time and dose response characteristics.

They found that the MTK1-mediated redox sensing system is crucial for delayed and sustained SAPK activity and dictates cell fate decisions including cell death, and IL-6?*3?production during respiratory burst in macrophages. Their results delineate a molecular mechanism by which cells generate optimal biological responses under fluctuating redox environments.

For details of the research, please see the paper.

Expected to be applied to the treatment of cancer, metabolic syndrome...

Professor Takekawa, at the Institute of Medical Science, the University of Tokyo, says, "This study has revealed a part of the oxidative stress response mechanism of the human body. The Cys residue in the MTK1 molecule, which is important for its function as an oxidative stress sensor, is highly conserved not only in humans but also in a wide variety of vertebrates, and the MTK1-mediated oxidative stress response is also evolutionarily conserved. This is strongly suggestive that the mechanism is common to various vertebrates."

The research group hopes that the findings of this research will be used in the future to develop therapeutic agents for various diseases related to reactive oxygen species such as cancer, chronic inflammatory diseases, and metabolic syndrome. These results were obtained as a cooperative effort with Professor Hiroaki Miki at Research Institute for Microbial Diseases, Osaka University in Japan.

Nowadays, life in the soil must contend with several problems at once. The biomass of small animals that decompose plants in the soil and thus maintain its fertility is declining both as a result of climate change and over-intensive cultivation. To their surprise, however, scientists from the Helmholtz Centre for Environmental Research (UFZ) and the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig have discovered that this effect occurs in two different ways: while the changing climate reduces the body size of the organisms, cultivation reduces their frequency. Even by farming organically, it is not possible to counteract all negative consequences of climate change, the researchers warn in the trade journal eLife.

Largely unnoticed and in secret, an army of tiny service providers works below our feet. Countless small insects, arachnids and other soil dwellers are indefatigably busy decomposing dead plants and other organic material, and recycling the nutrients they contain. However, experts have long feared that these organisms, which are so important for soil fertility and the functioning of ecosystems, are increasingly coming under stress.

On the one hand, they are confronted with the consequences of climate change, which challenges them with high temperatures and unusual precipitation conditions with more frequent droughts. On the other hand, they also suffer from over-intensive land use. If, for example, a meadow is turned into a field, soil animals find fewer niches and food sources there. Intensive ploughing, mowing or grazing, as well as the use of pesticides and large amounts of fertilizer also have a negative effect. But what happens when soil life is faced with both challenges at the same time? "Until now, we knew almost nothing about this," says Dr Martin Schädler from the UFZ. But he and his colleagues at the UFZ and iDiv have very good opportunities to pursue such complex questions. The ecologist coordinates the "Global Change Experimental Facility" (GCEF) in Bad Lauchstädt near Halle. There, researchers can simulate the climate of the future on arable and grassland plots used with varying degrees of intensity. In large steel constructions reminiscent of greenhouses without a roof or walls, they recreate a scenario that could be typical for the region between 2070 and 2100: it is about 0.6 degrees warmer than today, in spring and autumn there is ten percent more precipitation and summers are about 20 percent drier. A team led by Martin Schädler and doctoral student Rui Yin has now investigated how these conditions affect mites and springtails. Both groups have many decomposers in their ranks, which play an important role in the nutrient cycles in the soil.

The results show that these soil animals are likely to dwindle even further due to climate change. "It is likely that not only smaller species will prevail, but also smaller individuals within the same species," says Martin Schädler. In any case, the examined specimens on the areas with higher temperatures and changed precipitation were on average about ten percent smaller than on the comparable areas with today's climate. Biologists have so far been familiar with such connections between body size and climate primarily in larger animals. For example, bear species in warm regions of the Earth are significantly smaller than the polar bear found in the Arctic. This is due to the fact that a small body has a comparatively large surface area over which it can release heat - which is an advantage in the tropics, but easily leads to cooling in polar regions. In poikilothermal animals such as insects, high temperatures also stimulate metabolism and developmental speed. "This creates new generations faster, but they remain smaller," explains Martin Schädler. If the mites and springtails from the plots with an altered climate are weighed, the total weight is therefore lower in comparison with those from the unaffected areas. But this is not good news. After all, these animals' decomposition performance also depends on this biomass. Less total weight therefore also means that nutrient recycling is slowed down. According to the experiment, over-intensive land use can also trigger a very similar effect. This is because the biomass in the soil also decreases as a result. "Interestingly, however, there is another process behind this," says Martin Schädler, summarising the most important result of the study. "Unlike the climate, use does not reduce the size of the animals, but their density." For example, around 47 percent fewer mites and springtails lived on GCEF plots cultivated conventionally compared with plots extensively used as meadows.

"The fascinating and sobering thing about it is that the effects of climate and use hardly influence each other," says the ecologist. Until now, many experts had hoped that eco-friendly agriculture could offer some kind of insurance against the negative consequences of climate change. After all, organic farming generally leads to a more diverse community in fields and grassland. However, it is thought that this makes such ecosystems less susceptible to climatic disturbances than conventionally used areas.

Yet when it comes to maintaining the performance of soil animals, this strategy does not seem to work: changes in temperature and precipitation reduce their biomass regardless of cultivation. "So not everything that threatens to break down as a result of warming can be saved by environmentally friendly land use," says Martin Schädler in summary. In order to mitigate the consequences of climate change, it is therefore necessary to tackle greenhouse gases directly - and as quickly as possible. "We can't assume that we'll come up with anything else."

Two decades or more before symptoms arise, plaques of a sticky protein called amyloid begin forming in the brains of people later diagnosed with Alzheimer's disease. Researchers at Washington University School of Medicine in St. Louis have shown that levels of a specific protein in the blood rise as amyloid plaques form in the brain. This protein can be detected in the blood of people who have yet to show signs of forgetfulness or confusion, making it a promising blood test to diagnose Alzheimer's before symptoms appear.

The findings are published July 28 in the Journal of Experimental Medicine.

"The finding of a unique tau species that is closely linked to changes caused by amyloid plaques will help to identify and predict people who have or will likely develop Alzheimer's disease," said senior author Randall J. Bateman, MD, the Charles F. and Joanne Knight Distinguished Professor of Neurology. "This will greatly accelerate research studies, including finding new treatments, as well as improving diagnosis in the clinic with a simple blood test."

Alzheimer's disease begins with a silent phase lasting two decades or more during which amyloid plaques slowly collect in the brain without causing obvious cognitive problems. For decades, researchers have been searching for an easy and affordable way to identify people in the so-called preclinical stage so that, once effective drugs are available, they could be treated and, ideally, never develop symptoms at all.

Positron emission tomography (PET) brain scans can identify people with amyloid plaques, but they are too time-consuming and expensive to be widely used for screening or diagnosis. Bateman and colleagues already are working on a blood test for amyloid that has shown promise at distinguishing people with amyloid in their brains from those without. But first author Nicolas Barthélemy, PhD, an instructor in neurology, Bateman and others realized that a different Alzheimer's protein - tau - also may be useful for identifying which people have amyloid plaques silently gathering in their brains.

Barthélemy and Bateman previously had discovered that people with amyloid plaques tend to have certain forms of tau in the cerebrospinal fluid that surrounds their brains and spinal cords. Sampling the cerebrospinal fluid requires a spinal tap, which some participants are reluctant to undergo, but proteins in the cerebrospinal fluid can spill over into the blood, which is easier to obtain. If these specific forms of tau could be found in a person's blood, they reasoned, that might be an indication that the person has the consequences of amyloid plaques in his or her brain.

To evaluate this possibility, the researchers analyzed blood samples and brain scans from 34 people participating in Alzheimer's research studies at the university's Charles F. and Joanne Knight Alzheimer's Disease Research Center. Nineteen of the participants had no amyloid in their brains, five had amyloid but no cognitive symptoms, and 10 had amyloid and cognitive symptoms. The researchers used a technique known as mass spectrometry to identify and measure the different forms of tau in the blood samples. They found that levels of a form of tau known as phosphorylated tau 217 correlated with the presence of amyloid plaques in the brain. People with amyloid in their brains had two to three times more of the protein in their blood than people without amyloid. These high levels were evident even in people with no signs of cognitive decline.

To verify their findings, the researchers repeated the analysis in a separate group of 92 people: 42 with no amyloid, 20 with amyloid but no cognitive symptoms, and 30 with amyloid and symptoms. In this analysis, levels of phosphorylated tau 217 in the blood correlated with the presence of amyloid in the brain with more than 90% accuracy. When the researchers looked only at people with no cognitive symptoms, blood levels of phosphorylated tau 217 distinguished those in the early, asymptomatic stage of Alzheimer's disease from healthy people with 86% accuracy.

"This is just an exploratory study, but we think phosphorylated tau 217 is a promising target for an early diagnostic test," Barthélemy said. "There was a large difference between the amyloid-positive and amyloid-negative groups, even amongst people who were cognitively normal. We did have to use a large volume of blood in this study, but we're working on reducing the volume. Once we improve the way we are preparing and concentrating the sample, we will be a step closer to developing a tau-based blood test that can identify people at risk of developing Alzheimer's dementia before symptoms arise."

ITHACA, N.Y. - To remove carbon dioxide from the Earth's atmosphere in an effort to slow climate change, scientists must get their hands dirty and peek underground.

In an article published July 27 in Nature Geoscience, Cornell University's Johannes Lehmann and others wrote that scientists should develop new models that more accurately reflect the carbon-storage processes beneath our feet, in order to effectively draw down atmospheric carbon dioxide.

Carbon's journey into the soil is akin to a busy New York City rush hour. "Everything in the soil is bustling and changing all the time on a daily or hourly basis," said Lehmann, professor of soil biogeochemistry and the lead author on the piece.

"Microorganisms are on the street, but carbon quickly disappears around the corner or hides in nooks and crannies," he said. "Microorganisms in the soils that consume carbon can never be sure what tomorrow looks like."

Think of it this way: Sometimes soil microorganisms see a lot of carbon but still cannot devour it.

Lehmann and an international, interdisciplinary group of scientists propose the creation of new soil carbon-persistence models through the lens of "functional complexity" - the interplay between time and space in soil carbon's changing molecular structure.

Functional complexity drives carbon sequestration, and scientists must know specifically how carbon stays in the ground, according to Lehmann.

"Even if soil microorganisms have a full smorgasbord in front of them, they don't know what to eat if there is very little of each kind of carbon," said Lehmann, a fellow at Cornell Atkinson Center for Sustainability. "Although there is plenty of carbon, microorganisms starve, especially if they have to adjust to ever-changing conditions in a crazy maze."

With new models, scientists believe they can find out exactly how sequestration works. It could then be properly reflected in the next assessment of the United Nations Intergovernmental Panel on Climate Change (IPCC) - which likely will address drawing down atmospheric carbon.

Lehmann said that with modeling techniques gleaned from the field of engineering, for example, soil scientists can find better management methods to reduce atmospheric carbon.

"Collaboration in a stellar group of thinkers from diverse disciplines was key for us to come up with a new view on this old conundrum," he said. "We seem to be building climate models based on an erroneous understanding of why organic carbon stays in soil and how microbes are eating it. We need a new thinking to incorporate the best models for IPCC and other climate prediction efforts."

They are used by 150 million women worldwide and have been around for over 60 years. Oral contraceptives - like birth control pills - are part of many women's lives, often starting during puberty and early adolescence. Do they have any impact on brain health? A uOttawa team of researchers has been investigating the question. We sat down with senior author Nafissa Ismail, Associate Professor at the uOttawa School of Psychology and University Research Chair in Stress and Mental Health, to learn more.

Why did you decide to look into the effects of oral contraceptives on stress reactivity and brain activity?

"Millions of women have been taking oral contraceptives, but little is known about whether the synthetic hormones found in the oral contraceptives have behavioural and neurophysiological effects, especially during puberty and early adolescence, which are critical periods of brain development.

Dr. Andra Smith, Full Professor at the School of Psychology, and I collaborated to investigate whether there are differences in stress reactivity - or how someone responds to stress - and brain structure and function between women who had begun taking oral contraceptives during puberty or in adulthood and those who had never used them. This study was carried out by graduate student Rupali Sharma, supported by imaging analyst Dr. Zhuo Fang and a team of undergraduate students."

What did you find?

"We found differences in brain structure and function between oral contraceptive users and non-users.

First, oral contraceptive use is linked to increased activation in the prefrontal cortex during working memory processing for negatively arousing stimuli, like images of a gun, car accident, etc.

In our study, we also used a social stressor and we also found that women who started using oral contraceptives during puberty or adolescence display a blunted stress response, meaning that they do not react to stressors as much as women who started taking oral contraceptives in adulthood.

Women who started using oral contraceptives during puberty or adolescence also experience different brain activity during working memory processing of neutral images compared to women who started using oral contraceptives during adulthood.

In summary, oral contraceptive use is related to significant structural changes in brain regions implicated in memory and emotional processing. It also alters stress reactivity."

Why is it important?

"Our findings offer critical insight into women's health. It brings awareness to the potential influences of oral contraceptive use.

It could also provide a neural mechanism for why some women develop mood-related disorders following oral contraceptive use. One possibility is depression. Some women have complained of depression symptoms during oral contraceptive use. We need to be aware of it and talk to our physician if we are experiencing these symptoms.

The goal of our research is not to worry women or to discourage them from taking oral contraceptives. We just want to advise them so that they can make an informed decision about what is best for them. There is still a lot of work to be done to fully understand the impact of oral contraceptives on women's health."

STONY BROOK, NY, July 27, 2020 - Two studies led by Stony Brook University researchers to be presented virtually at the Alzheimer's Association International Conference on July 28, 2020, indicate that World Trade Center (WTC) first responders are at risk for developing dementia. The studies included individuals with signs of cognitive impairment (CI) who show neuroradiological abnormalities and changes in their blood similar to that seen in Alzheimer's disease patients and those with related dementias.

One study in Alzheimer's and Dementia: Diagnosis, Assessment and Disease Monitoring (DADM) shows that many responders with CI have reduced gray matter thickness in the brain consistent with neurodegenerative conditions and evidence their brain "age" is about 10 years older on average than the normal population. This research is in collaboration with scientists at the Icahn School of Medicine at Mount Sinai.

The other study, to be published in Translational Psychiatry, reveals some responders with post-traumatic stress disorder (PTSD) and mild CI possess protein changes in their blood consistent with Alzheimer's.

"The environmental exposures and psychological pressures experienced by responders during 911 and its aftermath has had an insidious effect on their health and well-being," says Benjamin Luft, MD, Director of the Stony Brook WTC Health and Wellness Program. "Now nearly 20 years post-911, clinicians who care for these individuals are seeing more patients who are showing signs of cognitive disorders and possible dementia. Findings from our new studies provide data for the first time that support the idea that this population of patients who have cognitive impairment not only have psychological problems such as PTSD but may be at high-risk for neurodegenerative disorders, a possibility that needs immediate and continued investigation."

One study is the first to use MRI imaging to assess the brain matter of WTC responder patients with and without symptoms of CI. The goal of this study is to determine if WTC responders in their midlife have developed CI due to changes in their brain possibly caused by neurotoxins they were exposed to at Ground Zero. The age range of patients was 45 to 65 years, an age range where cortical atrophy is rare in the normal population.

Researchers measured the brain cortex, the area responsible for cognition. Cortical thickness is a consistent measure of brain atrophy commonly used in studies of patients with Alzheimer's and related dementias. Imaging revealed areas of the cortex are atrophied in many WTC patients with cognitive impairment, compared to control subjects.

"While there are many reasons for cognitive decline because of brain changes, the loss of gray matter in the brain is one of the most concerning and can be measured by cortical thickness," explains Sean Clouston, PhD, lead author and Associate Professor of Family, Population and Preventive Medicine and in the Program in Public Health. "We found a direct correlation between those suffering from cognitive impairment and cortical thickness, indicating a reduction in gray matter of the brain at levels consistent with neurodegenerative disease."

The overall amount of cortical atrophy in responders with CI was significantly more than responders who did not have CI symptoms, as well as to the general population based on normative data.

According to the authors, the MRI imaging revealed that cortical thickness was significantly reduced in 23 out of 34 cortical regions among those with CI. These included the frontal, temporal and occipital lobes. When compared to published data, both responders with CI and those without CI showed significant reductions in cortical thickness in seven regions in or near the temporal lobe potentially indicative of a population-level effect.

Dr. Clouston said that the level of reduction in the cortical thickness in many responders is similar to that in patients with dementia and is "a possible indicator of early stage dementia with possible early onset dementia likely to occur for a portion of these individuals at midlife."

However, he explains that these patients need to be studied longitudinally to determine whether these changes progress over time. Additional imaging and other related brain research is also necessary to determine the cause or causes of brain atrophy in WTC responders.

The second study describes an analysis of 276 proteins in the blood in 181 WTC male responders in midlife - their average age 55 years.

Each of the identified proteins are instrumental to a range of processes indicative of neurological diseases, cellular regulation, immunology, cardiovascular, inflammatory, developmental and metabolism functions.

Given that PTSD and mild CI are common to 911 responders - which affect their cognitive and memory processes - individuals with these conditions were studied.

By using a sophisticated process that identifies dysregulation of proteins among the 276 identified for the study, the researchers found that WTC responders with mild CI also had proteinopathy, or problematic changes in the proteome, consistent with Alzheimer's and related diseases as well as other neuropsychiatric conditions.

"We believe that neuro-inflammation is a possible mechanism in which responders with PTSD appear to be at a higher risk of developing mild cognitive impairment," said Dr. Luft, senior author. "We hope our unique analysis of proteins associated with cognitive impairment-related diseases in this population is an additional way to identify their risk based on changes in their body likely due from their exposures."

Studies and simulations of global land precipitation and summer hemispheric precipitation have received much scientific and societal attention due to the impacts on economic development. Therefore, it is necessary to evaluate and improve the simulation capability of precipitation for models.

Recently, several modeling centers have released their Coupled Model Intercomparison Project Phase 6 (CMIP6) datasets. Taking the Global Monsoons Model Intercomparison Project (GMMIP) and historical experiments conducted by the Flexible Global Ocean-Atmosphere-Land System (FGOALS) climate system model, which was developed at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS), as examples, the simulation performance for global precipitation and summer hemispheric precipitation are assessed in a recent study published in Atmospheric and Oceanic Science Letters.

"Previous studies have shown that the leading mode of global precipitation is ENSO-related rainfall with interannual variability, while the long-term trend is related to increasing temperatures. Therefore, the fidelity of different timescales should be considered," explains Dr. He from LASG/IAP. "For FGOALS-f3-L, the GMMIP simulation significantly exceeds the historical experiment on different timescales. Based on the difference of experimental design and the influence of SSTAs (sea surface temperature anomalies) on interannual precipitation, we explored the possible cause of the simulation discrepancy."

According to Dr. He's study, the simulation performance of sea surface temperature (SST) forcing affects the simulation performance for global precipitation significantly, especially the tropical Pacific SSTA. In addition, different regions respond differently to the Niño3.4 region SSTA and the ENSO effects are concentrated at low- to mid-latitudes.

"Realistic simulation of the SST field is necessary for CAS FGOALS-f3-L to capture the temporal characteristics of global and hemispheric land precipitation," concludes Dr. He.

JULY 27, 2020, NEW YORK -- A Ludwig Cancer Research study has identified a new instance in which the simultaneous mutation of two nonessential genes--neither of which is on its own vital to cell survival--can cause cancer cell death.

Led by Ludwig San Diego Member Richard Kolodner and published in the current Proceedings of the National Academy of Sciences, the study also demonstrates that this deadly synergy, or "synthetic lethality," can be replicated by a drug-like molecule and could be exploited for cancer therapy.

The development and FDA approval of a new generation of drugs, called PARP inhibitors, to treat malignancies with defects in the tumor suppressor genes BRCA1 and BRCA2, which are implicated in breast, ovarian and many other types of cancers, has generated considerable interest in exploiting synthetic lethal interactions for the development of cancer therapies.

Scientists, including Kolodner's group, are on the hunt for other synthetic lethal interactions in cancers. "PARP inhibitors are a great advance, but they're not perfect," says Kolodner. "Patients can become resistant to them, so there's always a need for newer and better treatments."

Building from studies conducted on yeast cells, Kolodner and colleagues discovered that disabling or removing FEN1, a mammalian gene that is important for DNA replication and repair, is detrimental to cancer cells with mutant forms of BRCA1 and 2.
"We've provided data that should make people consider FEN1 as a potentially interesting therapeutic target and demonstrated how yeast can be used to predict a whole range of synthetic lethal interactions, which can then be validated in bona fide cancer cell lines with genetic tools," says Kolodner.

In previous work using the yeast Saccharomyces cerevisiae as a model to identify and study genes that support the integrity of the genome, Kolodner and his colleagues found that the RAD27 gene has synthetic lethal interactions with 59 other non-essential yeast genes. Two such genes of note are RAD51 and RAD52, which play roles in DNA recombination.

FEN1 is a close counterpart, or homolog, of RAD27 in mammals. Based on their yeast studies, Kolodner and colleagues predicted that FEN1 would have synthetic lethal interactions with BRCA1 and BRCA2, which function in the same biochemical pathway in mammals as RAD51 and RAD52 do in yeast.

To test this hypothesis, they synthesized four FEN1-blocking molecules and used the best of them, C8, to suppress FEN1 activity in cancer cell lines with or without BRCA mutations. C8 turned out to be an effective killer of BRCA-mutant cells.

They then demonstrated that genetic disruption of FEN1 expression had the same effects as C8 did on BRCA-mutant cells, confirming that C8 worked by inducing synthetic lethality.

Finally, the scientists grafted C8-sensitive and C8-resistant tumors into mice and showed that C8 significantly inhibited the growth of the C8-sensitive tumors but not the C8-resistant tumors. Interestingly, not all the cancer cell lines and tumors that responded to C8 treatment were BRCA deficient, indicating that FEN1 has synthetical lethal interactions with other genes as well.

These findings identify FEN1 as a novel target for drugs to treat a variety of malignancies by the induction of synthetic lethality. They also demonstrate that yeast-based screens are a powerful tool for accelerating the discovery of synthetic lethal interactions of potential therapeutic value--an ongoing project in the Kolodner laboratory.

The large-scale loss of eelgrass in a major California estuary -- Morro Bay -- may be causing widespread erosion, according to a new study from California Polytechnic State University.

In recent years, Morro Bay's iconic eelgrass beds, which provide the estuary's primary living habitat, experienced a massive die-off, declining more than 90 percent since 2007. Efforts to restore the eelgrass have had mixed success in many parts of the bay, and this seagrass is now only found close to the mouth of the bay and sporadically in other regions.

Seagrass systems are found throughout the world and provide many ecosystem services including fish nursery habitats, forage for migratory birds, nutrient cycling, carbon storage and sediment stabilization.

"The loss of eelgrass in the Morro Bay estuary is analogous to the loss of trees in a rainforest," says lead author and Cal Poly physics Professor Ryan Walter. "Not only do you lose the plants, but you also lose all of the services that they provide for the entire ecosystem."

By slowing down currents and decreasing wave forces, seagrasses help stabilize sediment and prevent erosion. Over the last century, Morro Bay has been building up sediment quickly and is dredged annually.

After the eelgrass died off, however, erosion took place in more than 90% of the places where eelgrass previously grew. In some places, the erosion removed enough sediment to cause the water depth to increase by as much as 50% compared to when eelgrass was present. At the mouth of the estuary where eelgrass remains, sediment is still building up as it did in the past.

"These erosional changes are sizable considering that Morro Bay, a modified estuary, has historically suffered from accelerated sedimentation," Walter said.

Globally, seagrasses in the nearshore coastal environment are among the most threatened ecosystems on the planet. Generally, losses of seagrasses can lead to increased shoreline and estuarine erosion.

On the other hand, it is possible that the erosion in Morro Bay may create new opportunities for seagrass recovery by increasing the depth and suitable habitat for eelgrass in certain locations. Recent restoration attempts by the Morro Bay National Estuary Program have been successful, and there is evidence of a partial recovery in portions of the bay. Tracking changes in sediment in places like Morro Bay will become increasingly important as climate change is expected to drive sea level increases and shoreline change.

"Morro Bay is an estuary of national importance that is under transition with system-wide eelgrass loss, subsequent sediment loss and now some signs of eelgrass recovery. Understanding the dramatic changes in Morro Bay can help identify important factors for management and conservation of eelgrass-dominated systems globally," said coauthor Jennifer O'Leary, former California Sea Grant Extension Specialist.

Scientists at the Department of Energy's Oak Ridge National Laboratory have demonstrated a direct relationship between climate warming and carbon loss in a peatland ecosystem. Their study published in AGU Advances provides a glimpse of potential futures where significant stores of carbon in peat bogs could be released into the atmosphere as greenhouse gases.

Peatlands currently cover around 3% of Earth's landmass and hold at least a third of global soil carbon -- more carbon than is stored in the world's forests.

Peat bogs are particularly good at locking away carbon because of the cold, wet, acidic conditions that preserve meters-deep layers of ancient plant matter. Scientists have taken a keen interest in these enormous carbon reserves, questioning how much and how quickly the hotter, drier conditions in a peatland bog can trigger microbial processes that release carbon in the form of carbon dioxide and methane into the air, furthering the warming cycle as the gases trap heat in the atmosphere.

Enter DOE's Spruce and Peatland Responses Under Changing Environments, or SPRUCE project, a unique whole ecosystem manipulation experiment in the forests of northern Minnesota. SPRUCE uses a series of enclosures to expose large peatland plots to five different temperatures, with the hottest of the chambers experiencing an increase of about 16 degrees Fahrenheit above and deep belowground. Half the enclosures also received elevated levels of carbon dioxide.

This futuristic experiment allows scientists to measure the effects of conditions this ecosystem has never experienced before, providing a glimpse of potential future climates.

"Because of DOE's investment in a large-scale experiment, we've been able to study whole ecosystem warming across a range of temperatures that can't be extrapolated from historical data," said Paul Hanson, ORNL ecosystem scientist and SPRUCE project coordinator. "In doing so, we have evidence that carbon losses will be anticipated for rapidly changing peatland systems in the future."

Hanson and his colleagues examined three years of SPRUCE data, tracking changes in plant growth, water and peat levels, microbial activity, fine root growth and other factors that control the movement of carbon into and out of the ecosystem. Together, these intakes and outputs make up what's known as the carbon budget.

The study found that in just three years, all warmed bog plots turned from carbon accumulators into carbon emitters -- marking the first time whole-ecosystem plots have been used to document such changes. This fundamental shift in the nature of the bog occurred even at the most modest level of warming (about 4 degrees F above ambient temperature), and showed carbon loss rates five to nearly 20 times faster than historical rates of accumulation.

Warmer temperatures directly translated into greater carbon emissions, with the warmest of the experimentally heated plots emitting the most carbon dioxide and methane. The scientists were surprised to find such a linear relationship between heat and carbon loss.

"This is a very tight relationship for biological data," Hanson said. "These results were within the range of hypotheses that we allowed ourselves to think about, but the sensitivity of carbon loss to temperature was a bit of a surprise."

The decline of sphagnum moss, a key species in this ecosystem, contributed notably to the net carbon loss. A previous study by ORNL colleague Richard Norby detailed sphagnum's role in accumulating carbon in peat and its potentially irreversible decay as warming dries out bogs.

The SPRUCE data will inform a new wetland model for potential use in DOE's Energy Exascale Earth System Model project, which uses high-performance computing to simulate and predict environmental changes important to the energy sector. The wetland model accurately predicted the temperature effects but overestimated the impact of elevated carbon dioxide compared with the SPRUCE data, which showed no significant ecosystem-level effects after three years of treatment.

Today, the word probiotic is used to describe all kinds of "good" microorganisms in foods and supplements: those found in yogurt or fermented sauerkraut, or even those found naturally in the human digestive tract. But this overly broad use of the term poses a scientific problem: it does not convey a distinction between bacterial strains that have a possible health benefit in humans, and strains that have a demonstrated health benefit, as shown in a human study. The frequent misuse of the term reduces transparency for consumers and sows confusion about what probiotic consumption really achieves.

Already, scientists have come up with a very specific definition of probiotics: "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host". And now, an open-access paper published in Frontiers in Microbiology builds on this definition, describing four simple criteria for accurate use of the word probiotic. The paper was published by eight scientists, including two board members from the International Scientific Association for Probiotics and Prebiotics (ISAPP), and was initiated by IPA Europe.

The scientists agreed that for a bacterial strain or strains to be called a probiotic, it should be: (1) pure and properly named (or "characterized"); (2) safe for its intended purpose; (3) supported by at least one well-designed human clinical trial that shows a health benefit; and (4) maintained alive in the product in a high enough dose to convey its health benefits, all the way through its shelf life.

Correct use of the term probiotic, per these criteria, will give consumers better transparency about the benefits they can expect when they consume products that contain live microorganisms. It will also allow them to weigh the costs and benefits of different products in the marketplace.

Going forward, the authors encourage scientists and companies to use these minimum criteria for identifying true probiotics. But until the time when the term is used correctly in all scientific papers and on all product labels, consumers should not assume that the word probiotic guarantees a health benefit.

An international team of researchers has published the most detailed submarine map of the Artic Ocean. The study, which counts on the participation of the experts Miquel Canals, José Luis Casamor and David Amblàs, from the Consolidated Research Group on Marine Geosciences of the University of Barcelona, has been published in Nature's journal Scientific Data.

The map is the 4.0 version of the International Bathymetric Chart of the Arctic Ocean (IBCAO), an initiative that was created in 1997 in Saint Petersburg (Russia) in order to map the depths of the Arctic floors. Published in digital format, the new chart expands up to 19.6% the submarine surface mapped in previous versions.

"The 4.0 IBCAO map is this year's contribution to the Nippon Foundation-GEBCO Seabed 2030, whose objective is to map all seas and oceans in the world by 2030", notes Martin Jakobsson, professor at the Stockholm University (Sweden), who led the scientific team with experts from fifteen countries, together with Larry Mayer, from the University of New Hampshire (United States).

The new bathymetric chart of the Arctic Ocean

With a strategic position, the Arctic is a mythic ocean in the story of the great geographical explorations to discover the secrets of the polar regions. The northernmost ocean of the planet -also the smallest and shallowest one- plays a decisive role in the regulation of the planet's climate and it is the most sensitive polar region to the effects of global warming. According to some predictions, the progressive loss of the marine ice layers could open the navigation to some areas which were inaccessible so far, such as the Northwest Passage, the legendary marine route pursued by many 19th century expeditions, which joins the boreal Pacific and Atlantic oceans.

"The potential difficulty for the current science campaigns in the Arctic is the access to places which are permanently covered by marine ice, and the short-lived duration of the navigation period. However, global warming made these inaccessible areas easier to reach now", notes Professor Miquel Canals, head of the Consolidated Research Group on Marine Sciences of the UB.

Since 2018, the team of the UB has contributed to the 4.0 IBCAO map with data mainly obtained through the multibeam bathymetry in oceanographic campaigns in the Arctic, specially in the western area in the Barents Sea, "a volunteering collaboration to benefit science and knowledge", as Miquel Canals states. In its different editions, the IBCAO maps received thousands of downloads over the years and are widely used by governments, companies and researchers with scientific interest and activities in the Arctic.

The new cartography has a volume with a higher and better resolution data than the previous versions, and it includes marine regions which were unknown to date. "This results from the efforts made by an international cooperation, which counts on the participation of many institutions and researchers who provided their scientific data to reach a common objective: discovering the depths of the Arctic Ocean", notes Canals, professor at the Department of Earth and Ocean Dynamics at the Faculty of Earth Sciences of the UB.

Multibeam probes and nuclear submarine under the Arctic ice

In order to carry out the IBCAO 4.0 map, the team used the same technology used in the submarine study in other regions of the ocean. "The compounds of the new map -mainly the most recent ones- were obtained through the most advanced multibeam bathymetry systems that exist. These data come from oceanographic vessels, ice breakers and nuclear submarines, the only ones to map those areas under the iced sea, impossible to reach with other ships", notes Canals.

"Regarding the data processing and fusion -with a new Mallat algorithm-, new techniques were added, and provided an excellent result", adds the expert.

Ocean currents, climate regulation and stability of ocean floors

In general, a better and larger cartography helps to broaden the knowledge on the geological and glacial evolution of such a sensitive region like the Arctic. Therefore, the new bathymetric map identifies a great variety of the shape of the relief with glacial origins, "some at large scales -from hundreds to thousands of meters in length-, that show the direction of the movement of the ice on the ocean floors, which helps to reconstruct the geological processes of the recent past in arctic latitudes".

Bathymetrical data are relevant in other fields of polar science, such as the study of the path of ocean currents -and therefore, the distribution of the heat-, the sea-ice decline, the effect of inflowing warm waters on tidewater glaciers, and the stability of marine based ice streams and outlet glaciers grounded on the seabed.

One of the most spectacular formations in the Arctic ocean floors is the Lomonosov Ridge, a geological element with more than 1,600 kilometres of length "which connects Northern Greenland and Siberia and crosses the ocean leaving deep basins in both sides", notes canals. "The most recent cartography studies carried out with ice breakers, revealed the presence of thresholds that influence the exchange of water between both basins, and anchoring marks in ice platforms on the ridge", he adds.

The IBCAO 4.0 bathymetric chart also reveals the detailed map of the Greenland fiords, and provides data of interest for the development of predictive models on the behaviour of the ice sheet -currently undergoing a rapid recession- which covers the island and on the sea level rise worldwide.

The challenge of mapping marine floors worldwide

To date, researchers have mapped about the fifth part of the ocean floors worldwide. Knowing the submarine relief of the global ocean is essential to manage and protect the marine and coastal ecosystems, as stated in one of the objectives of the UN Sustainable Development Goals (SDG), approved by the General Assembly in 2015.

Within the frame of the international effort to study the Arctic marine floors, the Consolidated Research Group on Marine Geosciences of the UB is one of the teams that take part in the Nippon Foundation-GEBCO Seabed 2030, the most ambitious global project to complete a great task in marine geosciences: high-resolution submarine bathymetry in all oceans worldwide.

Singapore, 27 July 2020 - Researchers from Singapore-MIT Alliance for Research and Technology (SMART), MIT's research enterprise in Singapore, have found a practical way to induce a strong and broad immunity to the dengue virus based on proof-of-concept studies in mice. Dengue is a mosquito-borne viral disease with an estimated 100 million symptomatic infections every year. It is endemic in over 100 countries in the world, from the United States to Africa and wide swathes of Asia. In Singapore, over 1,700 dengue new cases were reported recently.

The study is reported in a paper titled "Sequential immunization induces strong and broad immunity against all four dengue virus serotypes" published in NPJ Vaccines. It is jointly published by SMART researchers Jue Hou, Shubham Shrivastava, Hooi Linn Loo, Lan Hiong Wong, Eng Eong Ooi, Jianzhu Chen from SMART's Infectious Diseases (ID) and Antimicrobial Resistance (AMR) Interdisciplinary Research Groups (IRGs).

The dengue virus (DENV) consists of four antigenically distinct serotypes and there is no lasting immunity following infection with any of the DENV serotypes, meaning someone can be infected again by any of the remaining three variants of DENVs.

Today, Dengvaxia® is the only vaccine available to combat dengue. It consists of four variant dengue antigens, one for each of the four serotypes of dengue, expressed from attenuated yellow-fever virus. The current three doses of immunisation with the tetravalent vaccine induces only suboptimal protection against DENV1 and DENV2. Furthermore, in people who have not been infected by dengue, the vaccine induces a more severe dengue infection in the future. Therefore in most of the world, the vaccination is only given to those who have been previously infected.

To help overcome these issues, SMART researchers tested on mice whether sequential immunisation (or one serotype per dose) induces stronger and broader immunity against four DENV serotypes than tetravalent-formulated immunisation - and found that sequential immunisation induced significantly higher levels of virus-specific T cell responses than tetravalent immunisation. Moreover, sequential immunisation induced higher levels of neutralising antibodies to all four DENV serotypes than tetravalent vaccination.

"The principle of sequential immunisation generally aligns with the reality for individuals living in dengue endemic areas, whose immune responses may become protective after multiple heterotypic exposures," said Professor Eng Eong Ooi, SMART AMR Principal Investigator and senior author of the study. "We were able to find a similar effect based on the use of sequential immunisation, which will pave the way for a safe and effective use of the vaccine and to combat the virus."

Upon these promising results, the investigators will aim to test the sequential immunisation in humans in the near future.