2,137 research outputs found
Evidence of Titan's Climate History from Evaporite Distribution
Water-ice-poor, 5-m-bright material on Saturn's moon Titan has
previously been geomorphologically identified as evaporitic. Here we present a
global distribution of the occurrences of the 5-m-bright spectral unit,
identified with Cassini's Visual Infrared Mapping Spectrometer (VIMS) and
examined with RADAR when possible. We explore the possibility that each of
these occurrences are evaporite deposits. The 5-m-bright material covers
1\% of Titan's surface and is not limited to the poles (the only regions with
extensive, long-lived surface liquid). We find the greatest areal concentration
to be in the equatorial basins Tui Regio and Hotei Regio. Our interpretations,
based on the correlation between 5-m-bright material and lakebeds, imply
that there was enough liquid present at some time to create the observed
5-m-bright material. We address the climate implications surrounding a
lack of evaporitic material at the south polar basins: if the south pole basins
were filled at some point in the past, then where is the evaporite
Tectonics of the Dalrymple Trough and uplift of the Murray Ridge (NW Indian Ocean)
International audienceThe Dalrymple Trough is a 150-km-long, 30-km-wide basin located at the northern termination of the Owen Fracture Zone (OFZ), which is the present-day active India-Arabia plate boundary. The Dalrymple Trough is closely associated with the Murray Ridge, a complex of prominent bathymetric highs located on its eastern flank. Recent multibeam mapping of the connection between the Dalrymple Trough and the OFZ revealed a horsetail structure, which suggests a close relationship between geological histories of both structures. However, the 3-6 Ma age of initiation of the OFZ contrasts with the commonly accepted Early Miocene emplacement of the Dalrymple Trough. Recent seismic lines document a new tectonic history of the Dalrymple Trough, involving two major episodes of deformation along the India-Arabia plate boundary at ~ 8-10 Ma and ~ 1.9 ± 0.9 Ma. The 8-10 Ma episode is marked by a system of folds linked to the main uplift of the southern Murray Ridge and the first uplift of the northern Murray Ridge. This episode is related to a global plate reorganization event in the Late Miocene, well expressed by intraplate deformation in the Central Indian Ocean. The Dalrymple Trough opened at ~ 1.9 ± 0.9 Ma subsequently to the formation of a stepover at the India-Arabia plate boundary, coeval with the regional M-unconformity in the Oman abyssal plain, which marks a structural reorganization of the Makran accretionary wedge, and the last uplift of the northern Murray Ridge
Challenges and Innovative Technologies On Fuel Handling Systems for Future Sodium-Cooled Fast Reactors
International audienceThe reactor refuelling system provides the means of transporting, storing, and handling reactor core subassemblies. The system consists of the facilities and equipment needed to accomplish the scheduled refuelling operations. The choice of a FHS impacts directly on the general design of the reactor vessel (primary vessel, storage, and final cooling before going to reprocessing), its construction cost, and its availability factor. Fuel handling design must take into account various items and in particular operating strategies such as core design and management and core configuration. Moreover, the FHS will have to cope with safety assessments: a permanent cooling strategy to prevent fuel clad rupture, plus provisions to handle short-cooled fuel and criteria to ensure safety during handling. In addition, the handling and elimination of residual sodium must be investigated; it implies specific cleaning treatment to prevent chemical risks such as corrosion or excess hydrogen production. The objective of this study is to identify the challenges of a SFR fuel handling system. It will then present the range of technical options incorporating innovative technologies under development to answer the GENERATION IV SFR requirements
Prevalence of inherited ichthyosis in France: a study using capture-recapture method
International audienceBACKGROUND:Inherited ichthyoses represent a group of rare skin disorders characterized by scaling, hyperkeratosis and inconstant erythema, involving most of the tegument. Epidemiology remains poorly described. This study aims to evaluate the prevalence of inherited ichthyosis (excluding very mild forms) and its different clinical forms in France.METHODS:Capture - recapture method was used for this study. According to statistical requirements, 3 different lists (reference/competence centres, French association of patients with ichthyosis and internet network) were used to record such patients. The study was conducted in 5 areas during a closed period.RESULTS:The prevalence was estimated at 13.3 per million people (/M) (CI95%, [10.9 - 17.6]). With regard to autosomal recessive congenital ichthyosis, the prevalence was estimated at 7/M (CI 95% [5.7 - 9.2]), with a prevalence of lamellar ichthyosis and congenital ichthyosiform erythroderma of 4.5/M (CI 95% [3.7 - 5.9]) and 1.9/M (CI 95% [1.6 - 2.6]), respectively. Prevalence of keratinopathic forms was estimated at 1.1/M (CI 95% [0.9 - 1.5]). Prevalence of syndromic forms (all clinical forms together) was estimated at 1.9/M (CI 95% [1.6 - 2.6]).CONCLUSIONS:Our results constitute a crucial basis to properly size the necessary health measures that are required to improve patient care and design further clinical studies
Ezrin enhances line tension along transcellular tunnel edges via NMIIa driven actomyosin cable formation
Transendothelial cell macroaperture (TEM) tunnels control endothelium barrier function and are triggered by several toxins from pathogenic bacteria that provoke vascular leakage. Cellular dewetting theory predicted that a line tension of uncharacterized origin works at TEM boundaries to limit their widening. Here, by conducting high-resolution microscopy approaches we unveil the presence of an actomyosin cable encircling TEMs. We develop a theoretical cellular dewetting framework to interpret TEM physical parameters that are quantitatively determined by laser ablation experiments. This establishes the critical role of ezrin and non-muscle myosin II (NMII) in the progressive implementation of line tension. Mechanistically, fluorescence-recovery-after-photobleaching experiments point for the upstream role of ezrin in stabilizing actin filaments at the edges of TEMs, thereby favouring their crosslinking by NMIIa. Collectively, our findings ascribe to ezrin and NMIIa a critical function of enhancing line tension at the cell boundary surrounding the TEMs by promoting the formation of an actomyosin ring.Peer reviewe
Combined effects of time spent in physical activity, sedentary behaviors and sleep on obesity and cardio-metabolic health markers: a novel compositional data analysis approach
<div><p>The associations between time spent in sleep, sedentary behaviors (SB) and physical activity with health are usually studied without taking into account that time is finite during the day, so time spent in each of these behaviors are codependent. Therefore, little is known about the combined effect of time spent in sleep, SB and physical activity, that together constitute a composite whole, on obesity and cardio-metabolic health markers. Cross-sectional analysis of NHANES 2005–6 cycle on N = 1937 adults, was undertaken using a compositional analysis paradigm, which accounts for this intrinsic codependence. Time spent in SB, light intensity (LIPA) and moderate to vigorous activity (MVPA) was determined from accelerometry and combined with self-reported sleep time to obtain the 24 hour time budget composition. The distribution of time spent in sleep, SB, LIPA and MVPA is significantly associated with BMI, waist circumference, triglycerides, plasma glucose, plasma insulin (all p<0.001), and systolic (p<0.001) and diastolic blood pressure (p<0.003), but not HDL or LDL. Within the composition, the strongest positive effect is found for the proportion of time spent in MVPA. Strikingly, the effects of MVPA replacing another behavior and of MVPA being displaced by another behavior are asymmetric. For example, re-allocating 10 minutes of SB to MVPA was associated with a lower waist circumference by 0.001% but if 10 minutes of MVPA is displaced by SB this was associated with a 0.84% higher waist circumference. The proportion of time spent in LIPA and SB were detrimentally associated with obesity and cardiovascular disease markers, but the association with SB was stronger. For diabetes risk markers, replacing SB with LIPA was associated with more favorable outcomes. Time spent in MVPA is an important target for intervention and preventing transfer of time from LIPA to SB might lessen the negative effects of physical inactivity.</p></div
C-Nap1 mutation affects centriole cohesion and is associated with a Seckel-like syndrome in cattle
Caprine-like Generalized Hypoplasia Syndrome (SHGC) is an autosomal-recessive disorder in Montbéliarde cattle. Affected animals present a wide range of clinical features that include the following: delayed development with low birth weight, hind limb muscular hypoplasia, caprine-like thin head and partial coat depigmentation. Here we show that SHGC is caused by a truncating mutation in the CEP250 gene that encodes the centrosomal protein C-Nap1. This mutation results in centrosome splitting, which neither affects centriole ultrastructure and duplication in dividing cells nor centriole function in cilium assembly and mitotic spindle organization. Loss of C-Nap1-mediated centriole cohesion leads to an altered cell migration phenotype. This discovery extends the range of loci that constitute the spectrum of autosomal primary recessive microcephaly (MCPH) and Seckel-like syndromes
The RB824 antibody recognizes the mNeonGreen protein from Amphioxus lanceolatum by ELISA and immunofluorescence
RB820, RB821, RB822, RB823, RB824, and RB825 antibodies were assessed for their ability to recognize the Amphioxus lanceolatum mNeonGreen protein fused to a Twin-Strep-Tag using both ELISA and immunofluorescence assays. All the tested antibodies demonstrated the ability to detect the antigen in ELISA. RB824 successfully detected Amphioxus lanceolatum mNeonGreen by immunofluorescence in transiently transfected RAW264.7 cell
Prevalence and mechanisms of resistance to carbapenems in Enterobacteriaceae
Objectives: To determine the point prevalence of carbapenem-non-susceptible Enterobacteriaceae (CNSE) and carbapenemase-producing Enterobacteriaceae (CPE) isolates among hospitalized patients in Belgium.
Methods: Twenty-four hospital-based laboratories prospectively collected 200 non-duplicated Enterobacteriaceae isolates from clinical specimens of hospitalized patients over a 2 month period. All isolates were screened locally for decreased susceptibility to carbapenem drugs using a disc diffusion method according to CLSI interpretative criteria. CNSE strains were referred centrally for confirmation of carbapenemase by phenotypic and molecular testing.
Results: From February to April 2012, 158 of the 4564 screened Enterobacteriaceae isolates were categorized as non-susceptible to carbapenems, resulting in a point prevalence of CNSE of 3.5% (95% CI: 2.9%–4.2%; range per centre: 0.5%–8.5%). Of the 125 referred CNSE isolates, 11 Klebsiella pneumoniae isolates [OXA-48 (n=7), KPC type (n=3) and NDM type (n=1)], 1 OXA-48-positive Escherichia coli isolate and 1 KPC-positive Klebsiella oxytoca isolate were detected in eight hospitals. None of the 72 carbapenem-non-susceptible Enterobacter spp. isolates were confirmed as CPE. The minimal estimated point prevalence of CPE isolates was 0.28% (13/ 4564; 95% CI: 0.13%–0.44%) overall (range per centre: 0%–1.5%).
Conclusions: Despite the overall low prevalence of CNSE found in this study, the detection of CPE isolates in one-third of the participating centres raises concerns and highly suggests the spread and establishment of CPE in Belgian hospitals
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