Biologists have long searched for mechanisms responsible for the increase in species richness with decreasing latitude. The strong correlation between species richness and climate is frequently ...interpreted as reflecting a causal link via processes linked to energy or evolutionary rates. Here, we investigate how the aggregation of clades, as dictated by phylogeny, can give rise to significant climate–richness gradients without gradients in diversification or environmental carrying capacity. The relationship between climate and species richness varies considerably between clades, regions and time periods in a global-scale phylogenetically informed analysis of all terrestrial mammal species. Many young clades show negative richness–temperature slopes (more species at cooler temperatures), with the ages of these clades coinciding with the expansion of temperate climate zones in the late Eocene. In carnivores, we find steeply positive richness–temperature slopes in clades with restricted distributions and tropical origins (e.g. cat clade), whereas widespread, temperate clades exhibit shallow, negative slopes (e.g. dog–bear clade). We show that the slope of the global climate–richness gradient in mammals is driven by aggregating Chiroptera (bats) with their Eutherian sister group. Our findings indicate that the evolutionary history should be accounted for as part of any search for causal links between environment and species richness.
Globally, coastal communities and Small Island Developing States (SIDS) are most at risk of food insecurity due to a variety of natural and economic factors 1. Agricultural systems in these areas ...have a high level of exposure to climate risks including extreme weather and sea level rise 2. The populations that are most vulnerable to the risk of food insecurity are lower-income, indigenous, rural, ethnic, and religious minority groups, as well as women and children 3. Hydroponic Crop Cultivation (HCC) is a method of farming in which crops are grown in a nutrient rich solution in order to decrease the amount of resources, time, and space needed to grow. The project seeks to understand the role that HCC can play in mitigating risks to global food security and nutrition (GFSN) through three facets: 1) evaluation of the potential applications for HCC, including: SIDS, refugee camps, food deserts, rooftop gardens and apartment units, 2) ranking HCC against other technologies for GFSN risk mitigation, 3) build and test a floating, storm-resilient HCC system for the special case of GFSN in SIDS. The first two objectives will be ranked by a multi-criteria decision making (MCDM) method to determine the optimal use case while the last objective will be measured by the construction of a physical prototype. The system will use the Dutch bucket method of HCC to grow larger root crops, as well as enabling the functionality to grow multiple varieties of crops within the same system. The system will float in standing water and be able to withstand a reasonable amount of wind load, to allow the system to survive hurricanes. The HCC system relies on solar photovoltaic power to operate the HCC system, and will be designed to provide up to 72 hours of emergency power for communications and lighting. The functionality of the system will be assessed by testing in a calm water environment as well as simulations of wind loading.
More than 50 countries, mainly in Sub-Saharan Africa and South Asia, are not on course to meet the neonatal and under-five mortality target set by the Sustainable Development Goals (SDGs) for the ...year 2030. One important, yet neglected, aspect of child mortality rates is deaths occurring during the post-discharge period. For children living in resource-poor countries, the rate of post-discharge mortality within the first several months after discharge is often as high as the rates observed during the initial admission period. This has generally been observed within the context of acute illness and has been closely linked to underlying conditions such as malnutrition, HIV, and anemia. These post-discharge mortality rates tend to be underreported and present a major oversight in the efforts to reduce overall child mortality. This review will explore recurrent illness following discharge through determination of rates of, and risk factors for, pediatric post-discharge mortality in resource-poor settings.
Eligible studies will be retrieved using MEDLINE, EMBASE, and CINAHL databases. Only studies with a post-discharge observation period of more than 7 days following discharge will be eligible for inclusion. Secondary outcomes will include post-discharge mortality relative to in-hospital mortality, overall readmission rates, pooled estimates of risk factors (e.g. admission details vs discharge factors, clinical vs social factors), pooled post-discharge mortality Kaplan-Meier survival curves, and outcomes by disease subgroups (e.g. malnutrition, anemia, general admissions). A narrative description of the included studies will be synthesized to categorize commonly affected patient population categories and a random-effects meta-analysis will be conducted to quantify overall post-discharge mortality rates at the 6-month time point.
Post-discharge mortality contributes to global child mortality rates with a greater burden of deaths occurring in resource-poor settings. Literature concentrated on child mortality published over the last decade has expanded to focus on the fatal outcomes of children post-discharge and associated risk factors. The results from this systematic review will inform current policy and interventions on the epidemiological burden of post-discharge mortality and morbidity following acute illness among children living in resource-poor settings.
PROSPERO Registration ID: CRD42022350975.
In 2012, NASA's Curiosity rover landed on Mars to assess its potential as a habitat for past life and investigate the paleoclimate record preserved by sedimentary rocks inside the ...~150-kilometer-diameter Gale impact crater. Geological reconstructions from Curiosity rover data have revealed an ancient, habitable lake environment fed by rivers draining into the crater. We synthesize geochemical and mineralogical data from lake-bed mudstones collected during the first 1300 martian solar days of rover operations in Gale. We present evidence for lake redox stratification, established by depth-dependent variations in atmospheric oxidant and dissolved-solute concentrations. Paleoclimate proxy data indicate that a transition from colder to warmer climate conditions is preserved in the stratigraphy. Finally, a late phase of geochemical modification by saline fluids is recognized.
•We describe various imaging experiments made by ChemCam’s Remote Microscopic Imager.•RMI gives the LIBS geological context and serves for long distance reconnaissance.•RMI provides clues regarding ...the origin of rocks and their diagenetic evolution.
The Mars Science Laboratory rover, “Curiosity” landed near the base of a 5km-high mound of layered material in Gale crater. Mounted on the rover mast, the ChemCam instrument is designed to remotely determine the composition of soils and rocks located a few meters from the rover, using a Laser-Induced Breakdown Spectrometer (LIBS) coupled to a Remote Micro-Imager (RMI). We provide an overview of the diverse imaging investigations that were carried out by ChemCam’s RMI during the first year of operation on Mars. 1182 individual panchromatic RMI images were acquired from Sol 10 to Sol 360 to document the ChemCam LIBS measurements and to characterize soils, rocks and rover hardware. We show several types of derived imaging products, including mosaics of images taken before and after laser shots, difference images to enhance the most subtle laser pits, merges with color Mastcam-100 images, micro-topography using the Z-stack technique, and time lapse movies. The very high spatial resolution of RMI is able to resolve rock textures at sub-mm scales, which provides clues regarding the origin (igneous versus sedimentary) of rocks, and to reveal information about their diagenetic and weathering evolution. In addition to its scientific value over the range accessible by LIBS (1–7m), we also show that RMI can also serve as a powerful long distance reconnaissance tool to characterize the landscape at distances up to several kilometers from the rover.
Sepsis is the leading cause of death and disability in children. Every hour of delay in treatment is associated with an escalating risk of morbidity and mortality. The burden of sepsis is greatest in ...low- and middle-income countries where timely treatment may not occur due to delays in diagnosis and prioritization of critically ill children. To circumvent these challenges, we propose the development and clinical evaluation of a digital triage tool that will identify high risk children and reduce time to treatment. We will also implement and clinically validate a Radio-Frequency Identification system to automate tracking of patients. The mobile platform (mobile device and dashboard) and automated patient tracking system will create a low cost, highly scalable solution for critically ill children, including those with sepsis.
This is pre-post intervention study consisting of three phases. Phase I will be a baseline period where data is collected on key predictors and outcomes before implementation of the digital triage tool. In Phase I, there will be no changes to healthcare delivery processes in place at the study hospitals. Phase II will involve model derivation, technology development, and usability testing. Phase III will be the intervention period where data is collected on key predictors and outcomes after implementation of the digital triage tool. The primary outcome, time to treatment initiation, will be compared to assess effectiveness of the digital health intervention.
Smart technology has the potential to overcome the barrier of limited clinical expertise in the identification of the child at risk. This mobile health platform, with sensors and data-driven applications, will provide real-time individualized risk prediction to rapidly triage patients and facilitate timely access to life-saving treatments for children in low- and middle-income countries, where specialists are not regularly available and deaths from sepsis are common.
Clinical Trials.gov Identifier: NCT04304235, Registered 11 March 2020.
Until recently, Mars was considered a basalt-covered world, but this vision is evolving thanks to new orbital, in situ and meteorite observations, in particular of rocks of the ancient Noachian ...period. In this contribution we summarise newly recognised compositional and mineralogical differences between older and more recent rocks, and explore the geodynamic implications of these new findings. For example the MSL rover has discovered abundant felsic rocks close to the landing site coming from the wall of Gale crater ranging from alkali basalt to trachyte. In addition, the recently discovered Martian regolith breccia NWA 7034 (and paired samples) contain many coarse-grained noritic-monzonitic clasts demonstrably Noachian in age, and even some clasts that plot in the mugearite field. Olivine is also conspicuously lacking in these ancient samples, in contrast to later Hesperian rocks. The alkali-suite requires low-degree melting of the Martian mantle at low pressure, whereas the later Hesperian magmatism would appear to be produced by higher mantle temperatures. Various scenarios are proposed to explain these observations, including different styles of magmatic activity (i.e. passive upwelling vs. hotspots). A second petrological suite of increasing interest involves quartzo-feldspathic materials that were first inferred from orbit, in local patches in the southern highlands and in the lower units of Valles Marineris. However, identification of felsic rocks from orbit is limited by the low detectability of feldspar in the near infrared. On the other hand, the MSL rover has described the texture, mineralogy and composition of felsic rocks in Gale crater that are granodiorite-like samples akin to terrestrial TTG (Tonalite–Trondhjemite–Granodiorite suites). These observations, and the low average density of the highlands crust, suggest the early formation of ‘continental’ crust on Mars, although the details of the geodynamic scenario and the importance of volatiles in their generation are aspects that require further work.
•Rocks of early Mars are showing an ever increasing diversity in composition.•Existence of an alkaline suite, which was never observed before.•Evidences of low-degree melting of the Martian mantle at low pressure.•Plutonic granodiorite-like samples in Gale Crater akin to terrestrial TTG•In its early history some form of ‘continental’ crust was produced on Mars.
Selection of optimal second-line antiretroviral therapy (ART) has important clinical and programmatic implications. To inform the 2016 revision of the WHO ART guidelines, we assessed the comparative ...effectiveness and safety of available second-line ART regimens for adults and adolescents in whom first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens have failed.
In this systematic review and network meta-analysis, we searched for randomised controlled trials and prospective and retrospective cohort studies that evaluated outcomes in treatment-experienced adults living with HIV who switched ART regimen after failure of a WHO-recommended first-line NNRTI-based regimen. We searched Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials for reports published from Jan 1, 1996, to Aug 8, 2016, and searched conference abstracts published from Jan 1, 2014, to Aug 8, 2016. Outcomes of interest were viral suppression, mortality, AIDS-defining illnesses or WHO stage 3-4 disease, discontinuations, discontinuations due to adverse events, and serious adverse events. We assessed comparative efficacy and safety in a network meta-analysis, using Bayesian hierarchical models.
We identified 12 papers pertaining to eight studies, including 4778 participants. The network was centred on ritonavir-boosted lopinavir plus two nucleoside or nucleotide reverse transcriptase inhibitors. Ritonavir-boosted lopinavir monotherapy was the only regimen inferior to others. With the lower estimate of the 95% credible interval (CrI) not exceeding the predefined threshold of 15%, evidence at 48 weeks supported the non-inferiority of ritonavir-boosted lopinavir plus raltegravir to regimens including ritonavir-boosted protease inhibitor plus two NRTIs with respect to viral suppression (odds ratio 1·09, 95% CrI 0·88-1·35). Estimated efficacy of ritonavir-boosted darunavir (800 mg once daily) was too imprecise to determine non-inferiority. Overall, regimens did not differ significantly with respect to continuations, AIDS-defining illnesses or WHO stage 3-4 disease, or mortality.
With the exception of ritonavir-boosted lopinavir plus raltegravir, the evidence base is unable to provide strong support to alternative second-line options to ritonavir-boosted protease inhibitor plus two NRTIs, and thus more trials are warranted.
WHO.
Reducing child mortality in low-income countries is constrained by a lack of vital statistics. In the absence of such data, verbal autopsies provide an acceptable method to determining attributable ...causes of death. The objective was to assess potential causes of pediatric postdischarge mortality in children younger than age 5 years (under-5) originally admitted for suspected sepsis using verbal autopsies.
Secondary analysis of verbal autopsy data from children admitted to 6 hospitals across Uganda from July 2017 to March 2020. Structured verbal autopsy interviews were conducted for all deaths within 6 months after discharge. Two physicians independently classified a primary cause of death, up to 4 alternative causes, and up to 5 contributing conditions using the Start-Up Mortality List, with discordance resolved by consensus.
Verbal autopsies were completed for 361 (98.6%) of the 366 (5.9%) children who died among 6191 discharges (median admission age: 5.4 months interquartile range, 1.8-16.7; median time to mortality: 28 days interquartile range, 9-74). Most deaths (62.3%) occurred in the community. Leading primary causes of death, assigned in 356 (98.6%) of cases, were pneumonia (26.2%), sepsis (22.1%), malaria (8.5%), and diarrhea (7.9%). Common contributors to death were malnutrition (50.5%) and anemia (25.7%). Reviewers were less confident in their causes of death for neonates than older children (P < .05).
Postdischarge mortality frequently occurred in the community in children admitted for suspected sepsis in Uganda. Analyses of the probable causes for these deaths using verbal autopsies suggest potential areas for interventions, focused on early detection of infections, as well as prevention and treatment of underlying contributors such as malnutrition and anemia.
The Curiosity rover conducted the first field investigation of an active extraterrestrial dune. This study of the Bagnold dunes focuses on the ChemCam chemical results and also presents findings on ...the grain size distributions based on the ChemCam Remote Micro‐Imager and Mars Hand Lens Imager images. These active dunes are composed of grains that are mostly <250 μm. Their composition is overall similar to that of the aeolian deposits analyzed all along the traverse (“Aeolis Palus soils”). Nevertheless, the dunes contain less volatiles (Cl, H, and S) than the Aeolis Palus soils, which appear to be due to a lower content of volatile‐rich fine‐grained particles (<100 μm) or a lower content of volatile‐rich amorphous component, possibly as a result of (1) a lower level of chemical alteration, (2) the removal of an alteration rind at the surface of the grains during transport, (3) a lower degree of interaction with volcanic gases/aerosols, or (4) physical sorting that removed the smallest and most altered grains. Analyses of the >150 μm grain‐size dump piles have shown that coarser grains (150–250 μm) are enriched in the mafic elements Fe and Mn, suggesting a larger content in olivine compared to smaller grains (<150 μm) of the Bagnold dunes. Moreover, the chemistry of soils analyzed in the vicinity of the dunes indicates that they are similar to the dune material. All these observations suggest that the olivine content determined by X‐ray diffraction of the <150 μm grain‐size sample should be considered as a lower limit for the Bagnold dunes.
Key Points
Bagnold Dunes Campaign corresponds to the first in situ characterization of active dune field
Bagnold dunes lack <100 μm and > 1mm grains
Bagnold dunes are overall similar to Aeolis Palus soils in composition but are depleted in volatile‐rich amorphous component and present slightly more olivine
Plain Language Summary
The Curiosity rover, which is exploring the Gale Crater on Mars, has been investigating a dune field. This is the first time an active and extensive dune field is explored by a rover on Mars, and therefore, Curiosity used all the instruments on board in order to better understand how the dunes can form and with what processes and also to assess their chemistry. This in situ investigation was a great opportunity to compare with orbital data. Our work is focusing on chemical data from the ChemCam instrument, as well as on grain size distributions from the image analyses of two cameras. We show that, overall, the dunes are similar in chemistry to the soils analyzed along the traverse, but they are depleted in H, Cl, and S, suggesting that they contain less fine‐grained particles or less amorphous component (which is known to be enriched in such elements). This could be due to several processes that we try to investigate. Also, we show that the coarser grains of the dunes (150–250 µm) are enriched in Fe and Mn, probably due to an enrichment in olivine.
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