Showing papers by "Paul Sabatier University published in 2021"

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

Abstract: In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

Scientists' warning to humanity on the freshwater biodiversity crisis.

Abstract: Freshwater ecosystems provide irreplaceable services for both nature and society. The quality and quantity of freshwater affect biogeochemical processes and ecological dynamics that determine biodiversity, ecosystem productivity, and human health and welfare at local, regional and global scales. Freshwater ecosystems and their associated riparian habitats are amongst the most biologically diverse on Earth, and have inestimable economic, health, cultural, scientific and educational values. Yet human impacts to lakes, rivers, streams, wetlands and groundwater are dramatically reducing biodiversity and robbing critical natural resources and services from current and future generations. Freshwater biodiversity is declining rapidly on every continent and in every major river basin on Earth, and this degradation is occurring more rapidly than in terrestrial ecosystems. Currently, about one third of all global freshwater discharges pass through human agricultural, industrial or urban infrastructure. About one fifth of the Earth's arable land is now already equipped for irrigation, including all the most productive lands, and this proportion is projected to surpass one third by midcentury to feed the rapidly expanding populations of humans and commensal species, especially poultry and ruminant livestock. Less than one fifth of the world's preindustrial freshwater wetlands remain, and this proportion is projected to decline to under one tenth by midcentury, with imminent threats from water transfer megaprojects in Brazil and India, and coastal wetland drainage megaprojects in China. The Living Planet Index for freshwater vertebrate populations has declined to just one third that of 1970, and is projected to sink below one fifth by midcentury. A linear model of global economic expansion yields the chilling prediction that human utilization of critical freshwater resources will approach one half of the Earth's total capacity by midcentury. Although the magnitude and growth of the human freshwater footprint are greater than is generally understood by policy makers, the news media, or the general public, slowing and reversing dramatic losses of freshwater species and ecosystems is still possible. We recommend a set of urgent policy actions that promote clean water, conserve watershed services, and restore freshwater ecosystems and their vital services. Effective management of freshwater resources and ecosystems must be ranked amongst humanity's highest priorities.

Bimekizumab versus Secukinumab in Plaque Psoriasis.

Abstract: Background Bimekizumab is a monoclonal IgG1 antibody that selectively inhibits both interleukin-17A and interleukin-17F. The efficacy and safety of bimekizumab as compared with secukinumab...

Ancient DNA analysis

Abstract: Although the first ancient DNA molecules were extracted more than three decades ago, the first ancient nuclear genomes could only be characterized after high-throughput sequencing was invented. Genome-scale data have now been gathered from thousands of ancient archaeological specimens, and the number of ancient biological tissues amenable to genome sequencing is growing steadily. Ancient DNA fragments are typically ultrashort molecules and carry extensive amounts of chemical damage accumulated after death. Their extraction, manipulation and authentication require specific experimental wet-laboratory and dry-laboratory procedures before patterns of genetic variation from past individuals, populations and species can be interpreted. Ancient DNA data help to address an entire array of questions in anthropology, evolutionary biology and the environmental and archaeological sciences. The data have revealed a considerably more dynamic past than previously appreciated and have revolutionized our understanding of many major prehistoric and historic events. This Primer provides an overview of concepts and state-of-the-art methods underlying ancient DNA analysis and illustrates the diversity of resulting applications. The article also addresses some of the ethical challenges associated with the destructive analysis of irreplaceable material, emphasizes the need to fully involve archaeologists and stakeholders as part of the research design and analytical process, and discusses future perspectives. This Primer outlines the best ways to find, handle and analyse ancient DNA from various sources. The authors summarize ethical considerations and the importance of working closely with all stakeholders, including archaeologists, curators and descendant communities.

Efficacy and safety of risankizumab vs. secukinumab in patients with moderate-to-severe plaque psoriasis (IMMerge): results from a phase III, randomized, open-label, efficacy-assessor-blinded clinical trial.

Abstract: BACKGROUND Patients with plaque psoriasis treated with biologic therapies need more efficacious, safe and convenient treatments to improve quality of life Risankizumab and secukinumab inhibit interleukin-23 and interleukin-17A, respectively, and are effective in adult patients with moderate-to-severe plaque psoriasis but have different dosing regimens OBJECTIVES To compare directly the efficacy and safety of risankizumab vs secukinumab over 52 weeks METHODS IMMerge was an international, phase III, multicentre, open-label, efficacy-assessor-blinded, active-comparator study, in which adult patients with chronic, moderate-to-severe plaque psoriasis were randomized in a 1 : 1 ratio to treatment with risankizumab 150 mg or secukinumab 300 mg Primary efficacy endpoints were the proportions of patients achieving ≥ 90% improvement from baseline in Psoriasis Area and Severity Index (PASI 90) at week 16 (noninferiority comparison with margin of 12%) and week 52 (superiority comparison) RESULTS In total 327 patients from nine countries were treated with risankizumab (n = 164) or secukinumab (n = 163) Risankizumab was noninferior to secukinumab in the proportion of patients achieving PASI 90 at week 16 [73·8% vs 65·6%; difference of 8·2%, 96·25% confidence interval (CI)-2·2 to 18·6; within the 12% noninferiority margin] and superior to secukinumab at week 52 (86·6% vs 57·1%; difference of 29·8%, 95% CI 20·8-38·8; P < 0·001), thus meeting both primary endpoints All secondary endpoints (PASI 100, static Physician's Global Assessment 0 or 1, and PASI 75) at week 52 demonstrated superiority for risankizumab vs secukinumab (P < 0·001) No new safety concerns were identified CONCLUSIONS At week 52, risankizumab demonstrated superior efficacy and similar safety with less frequent dosing compared with secukinumab

Daratumumab, lenalidomide, and dexamethasone versus lenalidomide and dexamethasone alone in newly diagnosed multiple myeloma (MAIA): overall survival results from a randomised, open-label, phase 3 trial.

Abstract: Summary Background In the primary analysis of the phase 3 MAIA trial (median follow-up 28·0 months), a significant improvement in progression-free survival was observed with daratumumab plus lenalidomide and dexamethasone versus lenalidomide and dexamethasone alone in transplantation-ineligible patients with newly diagnosed multiple myeloma. Here, we report the updated efficacy and safety results from a prespecified interim analysis for overall survival. Methods MAIA is an ongoing, multicentre, randomised, open-label, phase 3 trial that enrolled patients at 176 hospitals in 14 countries across North America, Europe, the Middle East, and the Asia-Pacific region. Eligible patients were aged 18 years or older, had newly diagnosed multiple myeloma, had an Eastern Cooperative Oncology Group performance status score of 0–2, and were ineligible for high-dose chemotherapy with autologous stem-cell transplantation because of their age (≥65 years) or comorbidities. Patients were randomly assigned (1:1) using randomly permuted blocks (block size 4) by an interactive web response system to receive 28-day cycles of intravenous daratumumab (16 mg/kg, once per week during cycles 1–2, once every 2 weeks in cycles 3–6, and once every 4 weeks thereafter) plus oral lenalidomide (25 mg on days 1–21 of each cycle) and oral dexamethasone (40 mg on days 1, 8, 15, and 22 of each cycle; daratumumab group) or lenalidomide and dexamethasone alone (control group). Randomisation was stratified by International Staging System disease stage, geographical region, and age. Neither patients nor investigators were masked to treatment assignment. The primary endpoint was progression-free survival, which was centrally assessed, and a secondary endpoint was overall survival (both assessed in the intention-to-treat population). The safety population included patients who received at least one dose of the study treatment. The results presented here are from a prespecified interim analysis for overall survival, for which the prespecified stopping boundary was p=0·0414. This trial is registered with ClinicalTrials.gov , NCT02252172 . Findings Between March 18, 2015, and Jan 15, 2017, 952 patients were assessed for eligibility, of whom 737 patients were enrolled and randomly assigned to the daratumumab group (n=368) or the control group (n=369). At a median follow-up of 56·2 months (IQR 52·7–59·9), median progression-free survival was not reached (95% CI 54·8–not reached) in the daratumumab group versus 34·4 months (29·6–39·2) in the control group (hazard ratio [HR] 0·53 [95% CI 0·43–0·66]; p 15%) grade 3 or higher treatment-emergent adverse events were neutropenia (197 [54%] patients in the daratumumab group vs 135 [37%] patients in the control group), pneumonia (70 [19%] vs 39 [11%]), anaemia (61 [17%] vs 79 [22%]), and lymphopenia (60 [16%] vs 41 [11%]). Serious adverse events occurred in 281 (77%) patients in the daratumumab group and 257 (70%) patients in the control group. Treatment-related deaths occurred in 13 (4%) patients in the daratumumab group and ten (3%) patients in the control group. Interpretation Daratumumab plus lenalidomide and dexamethasone increased overall survival and progression-free survival in patients ineligible for stem-cell transplantation with newly diagnosed multiple myeloma. There were no new safety concerns. Our results support the frontline use of daratumumab plus lenalidomide and dexamethasone for patients with multiple myeloma who are ineligible for transplantation. Funding Janssen Research & Development.

The origins and spread of domestic horses from the Western Eurasian steppes.

Abstract: Domestication of horses fundamentally transformed long-range mobility and warfare1. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling2–4 at Botai, Central Asia around 3500 bc3. Other longstanding candidate regions for horse domestication, such as Iberia5 and Anatolia6, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 bc, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association7 between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 bc8,9 driving the spread of Indo-European languages10. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium bc Sintashta culture11,12. Analysis of 273 ancient horse genomes reveals that modern domestic horses originated in the Western Eurasian steppes, especially the lower Volga-Don region.

Surveillance of antimicrobial resistance in low- and middle-income countries: a scattered picture

Abstract: Data on comprehensive population-based surveillance of antimicrobial resistance is lacking In low- and middle-income countries, the challenges are high due to weak laboratory capacity, poor health systems governance, lack of health information systems, and limited resources Developing countries struggle with political and social dilemma, and bear a high health and economic burden of communicable diseases Available data are fragmented and lack representativeness which limits their use to advice health policy makers and orientate the efficient allocation of funding and financial resources on programs to mitigate resistance Low-quality data means soaring rates of antimicrobial resistance and the inability to track and map the spread of resistance, detect early outbreaks, and set national health policy to tackle resistance Here, we review the barriers and limitations of conducting effective antimicrobial resistance surveillance, and we highlight multiple incremental approaches that may offer opportunities to strengthen population-based surveillance if tailored to the context of each country

High immunogenicity of a messenger RNA based vaccine against SARS-CoV-2 in chronic dialysis patients.

Abstract: BACKGROUND: Patients with chronic kidney disease, dialysis patients and kidney-transplant patients are at high risk of developing severe coronavirus disease-19 (COVID-19). Data regarding the immunogenicity of anti-Severe Acute Respiratory Syndrome coronavirus-2 messenger RNA (anti-SARS-CoV-2 mRNA) vaccines in dialysis patients were published recently. We assessed the immunogenicity of anti-SARS-CoV-2 mRNA vaccine in dialysis patients. PATIENTS AND METHODS: One hundred-nine patients on hemodialysis (n = 85) or peritoneal dialysis (n = 24) have received two injections of 30-µg doses of BNT162b2 mRNA COVID-19 Vaccine (Pfizer-BioNTech), that were administered intramuscularly 28 days apart. Those who were still seronegative after the second dose were given a third dose one month later. Anti-SARS-CoV-2 antibodies were tested before and after vaccination. RESULTS: Ninety-one out of the 102 patients who had at least a one-month follow-up after the second (n = 97) or the third (n = 5) vaccine doses had anti-SARS-CoV-2 antibodies. The seroconversion rate was 88.7% (86 out of 97 patients) among SARS-CoV-2 seronegative patients at the initiation of vaccination. Receiving immunosuppressive therapy was an independent predictive factor for non-response to vaccination. CONCLUSION: Due to high immunogenicity and safety of mRNA vaccines, we strongly recommend prioritizing a two-doses vaccination of dialysis patients. A third dose can be required in non-responders to two doses. When possible, patients waiting for a kidney transplantation, should be offered the vaccine before transplantation.

Report on G4‐Med, a Geant4 benchmarking system for medical physics applications developed by the Geant4 Medical Simulation Benchmarking Group

Abstract: Background: Geant4 is a Monte Carlo code extensively used in medical physics for a wide range of applications, such as dosimetry, micro- and nanodosimetry, imaging, radiation protection, and nuclear medicine. Geant4 is continuously evolving, so it is crucial to have a system that benchmarks this Monte Carlo code for medical physics against reference data and to perform regression testing. Aims: To respond to these needs, we developed G4-Med, a benchmarking and regression testing system of Geant4 for medical physics. Materials and Methods: G4-Med currently includes 18 tests. They range from the benchmarking of fundamental physics quantities to the testing of Monte Carlo simulation setups typical of medical physics applications. Both electromagnetic and hadronic physics processes and models within the prebuilt Geant4 physics lists are tested. The tests included in G4-Med are executed on the CERN computing infrastructure via the use of the geant-val web application, developed at CERN for Geant4 testing. The physical observables can be compared to reference data for benchmarking and to results of previous Geant4 versions for regression testing purposes. Results: This paper describes the tests included in G4-Med and shows the results derived from the benchmarking of Geant4 10.5 against reference data. Discussion: Our results indicate that the Geant4 electromagnetic physics constructor G4EmStandardPhysics_option4 gives a good agreement with the reference data for all the tests. The QGSP_BIC_HP physics list provided an overall adequate description of the physics involved in hadron therapy, including proton and carbon ion therapy. New tests should be included in the next stage of the project to extend the benchmarking to other physical quantities and application scenarios of interest for medical physics. Conclusion: The results presented and discussed in this paper will aid users in tailoring physics lists to their particular application. (Less)

Erosion of global functional diversity across the tree of life

Abstract: Although one-quarter of plant and vertebrate species are threatened with extinction, little is known about the potential effect of extinctions on the global diversity of ecological strategies. Using trait and phylogenetic information for more than 75,000 species of vascular plants, mammals, birds, reptiles, amphibians, and freshwater fish, we characterized the global functional spectra of each of these groups. Mapping extinction risk within these spectra showed that larger species with slower pace of life are universally threatened. Simulated extinction scenarios exposed extensive internal reorganizations in the global functional spectra, which were larger than expected by chance for all groups, and particularly severe for mammals and amphibians. Considering the disproportionate importance of the largest species for ecological processes, our results emphasize the importance of actions to prevent the extinction of the megabiota.

Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centre

Abstract: We provide an updated assessment of the power of the Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at the TeV scale, via the associated gamma-ray signal from pair-annihilating dark matter particles in the region around the Galactic centre. We find that CTA will open a new window of discovery potential, significantly extending the range of robustly testable models given a standard cuspy profile of the dark matter density distribution. Importantly, even for a cored profile, the projected sensitivity of CTA will be sufficient to probe various well-motivated models of thermally produced dark matter at the TeV scale. This is due to CTA's unprecedented sensitivity, angular and energy resolutions, and the planned observational strategy. The survey of the inner Galaxy will cover a much larger region than corresponding previous observational campaigns with imaging atmospheric Cherenkov telescopes. CTA will map with unprecedented precision the large-scale diffuse emission in high-energy gamma rays, constituting a background for dark matter searches for which we adopt state-of-the-art models based on current data. Throughout our analysis, we use up-to-date event reconstruction Monte Carlo tools developed by the CTA consortium, and pay special attention to quantifying the level of instrumental systematic uncertainties, as well as background template systematic errors, required to probe thermally produced dark matter at these energies.

Gut microbiome, endocrine control of gut barrier function and metabolic diseases.

Abstract: Overweight and obesity are associated with several cardiometabolic risk factors, including insulin resistance, type 2 diabetes, low-grade inflammation and liver diseases. The gut microbiota is a potential contributing factor regulating energy balance. However, although the scientific community acknowledges that the gut microbiota composition and its activity (e.g. production of metabolites and immune-related compounds) are different between healthy subjects and subjects with overweight/obesity, the causality remains insufficiently demonstrated. The development of low-grade inflammation and related metabolic disorders has been connected with metabolic endotoxaemia and increased gut permeability. However, the mechanisms acting on the regulation of the gut barrier and eventually cardiometabolic disorders are not fully elucidated. In this review, we debate several characteristics of the gut microbiota, gut barrier function and metabolic outcomes. We examine the role of specific dietary compounds or nutrients (e.g. prebiotics, probiotics, polyphenols, sweeteners, and a fructose-rich diet) as well as different metabolites produced by the microbiota in host metabolism, and we discuss how they control several endocrine functions and eventually have either beneficial or deleterious effects on host health.

Opportunistic genomic screening. Recommendations of the European Society of Human Genetics

Abstract: If genome sequencing is performed in health care, in theory the opportunity arises to take a further look at the data: opportunistic genomic screening (OGS). The European Society of Human Genetics (ESHG) in 2013 recommended that genome analysis should be restricted to the original health problem at least for the time being. Other organizations have argued that ‘actionable’ genetic variants should or could be reported (including American College of Medical Genetics and Genomics, French Society of Predictive and Personalized Medicine, Genomics England). They argue that the opportunity should be used to routinely and systematically look for secondary findings—so-called opportunistic screening. From a normative perspective, the distinguishing characteristic of screening is not so much its context (whether public health or health care), but the lack of an indication for having this specific test or investigation in those to whom screening is offered. Screening entails a more precarious benefits-to-risks balance. The ESHG continues to recommend a cautious approach to opportunistic screening. Proportionality and autonomy must be guaranteed, and in collectively funded health-care systems the potential benefits must be balanced against health care expenditures. With regard to genome sequencing in pediatrics, ESHG argues that it is premature to look for later-onset conditions in children. Counseling should be offered and informed consent is and should be a central ethical norm. Depending on developing evidence on penetrance, actionability, and available resources, OGS pilots may be justified to generate data for a future, informed, comparative analysis of OGS and its main alternatives, such as cascade testing.

Mercury stable isotopes constrain atmospheric sources to the ocean.

Abstract: Human exposure to toxic mercury (Hg) is dominated by the consumption of seafood1,2. Earth system models suggest that Hg in marine ecosystems is supplied by atmospheric wet and dry Hg(ii) deposition, with a three times smaller contribution from gaseous Hg(0) uptake3,4. Observations of marine Hg(ii) deposition and Hg(0) gas exchange are sparse, however5, leaving the suggested importance of Hg(ii) deposition6 ill-constrained. Here we present the first Hg stable isotope measurements of total Hg (tHg) in surface and deep Atlantic and Mediterranean seawater and use them to quantify atmospheric Hg deposition pathways. We observe overall similar tHg isotope compositions, with median Δ200Hg signatures of 0.02‰, lying in between atmospheric Hg(0) and Hg(ii) deposition end-members. We use a Δ200Hg isotope mass balance to estimate that seawater tHg can be explained by the mixing of 42% (median; interquartile range, 24–50%) atmospheric Hg(ii) gross deposition and 58% (50–76%) Hg(0) gross uptake. We measure and compile additional, global marine Hg isotope data including particulate Hg, sediments and biota and observe a latitudinal Δ200Hg gradient that indicates larger ocean Hg(0) uptake at high latitudes. Our findings suggest that global atmospheric Hg(0) uptake by the oceans is equal to Hg(ii) deposition, which has implications for our understanding of atmospheric Hg dispersal and marine ecosystem recovery. Mercury deposition pathways from the atmosphere to the ocean remain uncertain, but mercury stable isotope measurements from the Atlantic and Mediterranean show that ocean uptake of gaseous elemental mercury is more important than previously thought.

Global transpiration data from sap flow measurements: the SAPFLUXNET database

Abstract: . Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, and carbon budgets at the land–atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observations. Here we introduce the first global compilation of whole-plant transpiration data from sap flow measurements (SAPFLUXNET, https://sapfluxnet.creaf.cat/ , last access: 8 June 2021). We harmonized and quality-controlled individual datasets supplied by contributors worldwide in a semi-automatic data workflow implemented in the R programming language. Datasets include sub-daily time series of sap flow and hydrometeorological drivers for one or more growing seasons, as well as metadata on the stand characteristics, plant attributes, and technical details of the measurements. SAPFLUXNET contains 202 globally distributed datasets with sap flow time series for 2714 plants, mostly trees, of 174 species. SAPFLUXNET has a broad bioclimatic coverage, with woodland/shrubland and temperate forest biomes especially well represented (80 % of the datasets). The measurements cover a wide variety of stand structural characteristics and plant sizes. The datasets encompass the period between 1995 and 2018, with 50 % of the datasets being at least 3 years long. Accompanying radiation and vapour pressure deficit data are available for most of the datasets, while on-site soil water content is available for 56 % of the datasets. Many datasets contain data for species that make up 90 % or more of the total stand basal area, allowing the estimation of stand transpiration in diverse ecological settings. SAPFLUXNET adds to existing plant trait datasets, ecosystem flux networks, and remote sensing products to help increase our understanding of plant water use, plant responses to drought, and ecohydrological processes. SAPFLUXNET version 0.1.5 is freely available from the Zenodo repository ( https://doi.org/10.5281/zenodo.3971689 ; Poyatos et al., 2020a). The “sapfluxnetr” R package – designed to access, visualize, and process SAPFLUXNET data – is available from CRAN.

Exfoliation and Delamination of Ti3C2Tx MXene Prepared via Molten Salt Etching Route.

Abstract: MXenes are two-dimensional metal carbides or nitrides that are currently proposed in many applications thanks to their unique attributes including high conductivity and accessible surface. Recently, a synthetic route was proposed to prepare MXenes from the molten salt etching of precursors allowing for the preparation of MXene (denoted as MS-MXenes, for molten salt MXene) with tuned surface termination groups, resulting in improved electrochemical properties. However, further delamination of as-prepared multilayer MS-MXenes still remains a major challenge. Here, we report on the successful exfoliation of MS-Ti3C2Txvia the intercalation of the organic molecule TBAOH (tetrabutylammonium hydroxide), followed by sonication to separate the layers. The treatment time could be adapted to tune the wetting behavior of the MS-Ti3C2Tx. As a result, a self-supported Cl-terminated MXene film could be prepared by filtration. Finally, MS-Ti3C2Tx used as a Li-ion battery anode could achieve a high specific capacity of 225 mAh g-1 at a 1C rate together with an excellent rate capability of 95 mAh g-1 at 167C. These results also show that tuning of the surface chemistry of MXene is of key importance to this field with the likely result being increased electrochemical performance.

The Use of Rifaximin in the Prevention of Overt Hepatic Encephalopathy After Transjugular Intrahepatic Portosystemic Shunt : A Randomized Controlled Trial.

Abstract: Background The efficacy of rifaximin in the secondary prevention of overt hepatic encephalopathy (HE) is well documented, but its effectiveness in preventing a first episode in patients after transjugular intrahepatic portosystemic shunt (TIPS) has not been established. Objective To determine whether rifaximin prevents overt HE after TIPS compared with placebo. Design Randomized, double-blind, multicenter, placebo-controlled trial. (ClinicalTrials.gov: NCT02016196). Participants 197 patients with cirrhosis undergoing TIPS for intractable ascites or prevention of variceal rebleeding. Intervention Patients were randomly assigned to receive rifaximin (600 mg twice daily) or placebo, beginning 14 days before TIPS and continuing for 168 days after the procedure. Measurements The primary efficacy end point was incidence of overt HE within 168 days after the TIPS procedure. Results An episode of overt HE occurred in 34% (95% CI, 25% to 44%) of patients in the rifaximin group (n = 93) and 53% (CI, 43% to 63%) in the placebo group (n = 93) during the postprocedure period (odds ratio, 0.48 [CI, 0.27 to 0.87]). Neither the incidence of adverse events nor transplant-free survival was significantly different between the 2 groups. Limitations The study's conclusion applies mainly to patients with alcoholic cirrhosis, who made up the study population. The potential benefit of rifaximin 6 months after TIPS and beyond remains to be investigated. Conclusion In patients with cirrhosis treated with TIPS, rifaximin was well tolerated and reduced the risk for overt HE. Rifaximin should therefore be considered for prophylaxis of post-TIPS HE. Primary funding source French Public Health Ministry.

Perseverance rover reveals an ancient delta-lake system and flood deposits at Jezero crater, Mars.

Abstract: Observations from orbital spacecraft have shown that Jezero crater, Mars, contains a prominent fan-shaped body of sedimentary rock deposited at its western margin. The Perseverance rover landed in ...

Lack of support for Deuterostomia prompts reinterpretation of the first Bilateria.

Abstract: The bilaterally symmetric animals (Bilateria) are considered to comprise two monophyletic groups, Protostomia (Ecdysozoa and the Lophotrochozoa) and Deuterostomia (Chordata and the Xenambulacraria). Recent molecular phylogenetic studies have not consistently supported deuterostome monophyly. Here, we compare support for Protostomia and Deuterostomia using multiple, independent phylogenomic datasets. As expected, Protostomia is always strongly supported, especially by longer and higher-quality genes. Support for Deuterostomia, however, is always equivocal and barely higher than support for paraphyletic alternatives. Conditions that cause tree reconstruction errors—inadequate models, short internal branches, faster evolving genes, and unequal branch lengths—coincide with support for monophyletic deuterostomes. Simulation experiments show that support for Deuterostomia could be explained by systematic error. The branch between bilaterian and deuterostome common ancestors is, at best, very short, supporting the idea that the bilaterian ancestor may have been deuterostome-like. Our findings have important implications for the understanding of early animal evolution.

Biotic homogenization destabilizes ecosystem functioning by decreasing spatial asynchrony.

Abstract: Our planet is facing significant changes of biodiversity across spatial scales. Although the negative effects of local biodiversity (α diversity) loss on ecosystem stability are well documented, the consequences of biodiversity changes at larger spatial scales, in particular biotic homogenization, that is, reduced species turnover across space (β diversity), remain poorly known. Using data from 39 grassland biodiversity experiments, we examine the effects of β diversity on the stability of simulated landscapes while controlling for potentially confounding biotic and abiotic factors. Our results show that higher β diversity generates more asynchronous dynamics among local communities and thereby contributes to the stability of ecosystem productivity at larger spatial scales. We further quantify the relative contributions of α and β diversity to ecosystem stability and find a relatively stronger effect of α diversity, possibly due to the limited spatial scale of our experiments. The stabilizing effects of both α and β diversity lead to a positive diversity-stability relationship at the landscape scale. Our findings demonstrate the destabilizing effect of biotic homogenization and suggest that biodiversity should be conserved at multiple spatial scales to maintain the stability of ecosystem functions and services.

Dire wolves were the last of an ancient New World canid lineage

Abstract: Dire wolves are considered to be one of the most common and widespread large carnivores in Pleistocene America1, yet relatively little is known about their evolution or extinction. Here, to reconstruct the evolutionary history of dire wolves, we sequenced five genomes from sub-fossil remains dating from 13,000 to more than 50,000 years ago. Our results indicate that although they were similar morphologically to the extant grey wolf, dire wolves were a highly divergent lineage that split from living canids around 5.7 million years ago. In contrast to numerous examples of hybridization across Canidae2,3, there is no evidence for gene flow between dire wolves and either North American grey wolves or coyotes. This suggests that dire wolves evolved in isolation from the Pleistocene ancestors of these species. Our results also support an early New World origin of dire wolves, while the ancestors of grey wolves, coyotes and dholes evolved in Eurasia and colonized North America only relatively recently. Dire wolves split from living canids around 5.7 million years ago and originated in the New World isolated from the ancestors of grey wolves and coyotes, which evolved in Eurasia and colonized North America only relatively recently.