Pratiques d'élevage dans les exploitations bovines allaitantes conduites sur pâturage dans les Hauts de la Réunion

Dans les Hauts de la Réunion, l’élevage bovin constitue la principale activité agricole. L’élevage naisseur «professionnel» représente 8828 vaches mères pour 497 exploitations. Ce sont des exploitations de taille modeste (18 vaches mères en moyenne) dont les performances animales sont en-deçà de leurs homologues métropolitaines. L’objectif de l’étude est d’analyser les pratiques des éleveurs naisseurs et d’en faire le lien avec les performances obtenues afin d’identifier des voies d’amélioration potentielles. Pour cela, 10 éleveurs ont fait l’objet d’un suivi de 1999 à 2002, qui était fondé sur l’évaluation des performances des animaux et sur l’enregistrement des pratiques des éleveurs en particularisant l’allotement, la gestion du pâturage et la complémentation alimentaire. Cet article montre que les pratiques sont variées et conditionnées par des objectifs de production différents: stratégies de maximisation des performances ou du chargement, simplification de la conduite.Cattle farming is the main agricultural activity in the Highlands of the Reunion Island. "Professional" suckling farming represents 8828 cows for 497 farms. They are modest sized farms (18 cows on the average) whose animal performances are lower than their metropolitan counterparts. The aim of the study was to analyse the practices of the suckling farmers with the purpose of improving their management. We carried out herd monitoring on 10 farms from 1999 to 2002 within this framework. This monitoring was based on the measurement of animal performances and on the recording of the farmers' practices in terms of livestock and grazing management. This article presents the analysis carried out on 3 categories of practices: the allotment, grazing management and supplementation. There are various practices underlain by different socioeconomic objectives. Thus, strategies can be founded on the maximisation of the animal performances, the stocking rate or simplification of the management

Le cadre géologique d'un site hydrothermal actif : la campagne STARMER 1 du submersible Nautile dans le Bassin Nord-Fidjien

International audienc

In situ geological and geochemical study of an active hydrothermal site on the North Fiji basin ridge

International audienc

Safety and efficacy of granulocyte/monocyte apheresis in steroid-dependent active ulcerative colitis with insufficient response or intolerance to immunosuppressants and/or biologics (ART trial): 12-week interim results

International audienceBACKGROUND AND AIMS: Patients with active, steroid-dependent ulcerative colitis with insufficient response or intolerance to immunosuppressants and/or biologic therapies have limited treatment options. Adacolumn, a granulocyte/monocyte adsorptive apheresis device, has shown clinical benefit in these patients. This study aimed to provide additional clinical data regarding the safety and efficacy of Adacolumn in this patient subgroup.METHODS: This single arm, open-label, multicentre trial (ART) was conducted at 18 centres across the UK, France and Germany. Eligible patients were 18-75 years old with moderate-to-severe, steroid-dependent active ulcerative colitis with insufficient response or intolerance to immunosuppressants and/or biologics. Patients received ≥5 weekly apheresis sessions with Adacolumn. The primary endpoint was clinical remission rate (clinical activity index ≤4) at Week 12.RESULTS: Eighty-six patients were enrolled. At Week 12, 33/84 (39.3%) of patients in the intention-to-treat population achieved clinical remission, with 47/84 (56.0%) achieving a clinical response (clinical activity index reduction of ≥3). Clinical remission was achieved in 30.0% of patients with prior immunosuppressant and biologic failure; steroid-free clinical remission and response were observed in 22.6% and 35.7% of these patients, respectively. Quality of life (Short Health Scale) significantly improved at Week 12 (p\textless0.0001). The majority of adverse events were of mild/moderate intensity.CONCLUSIONS: At Week 12, Adacolumn provided significant clinical benefit in a large cohort of steroid-dependent ulcerative colitis patients with previous failure to immunosuppressant and/or biologic treatment, with a favourable safety profile. These results are consistent with previous studies and support Adacolumn use in this difficult-to-treat patient subgrou

Mechanisms of Cognitive Impairment in Cerebral Small Vessel Disease: Multimodal MRI Results from the St George's Cognition and Neuroimaging in Stroke (SCANS) Study.

Cerebral small vessel disease (SVD) is a common cause of vascular cognitive impairment. A number of disease features can be assessed on MRI including lacunar infarcts, T2 lesion volume, brain atrophy, and cerebral microbleeds. In addition, diffusion tensor imaging (DTI) is sensitive to disruption of white matter ultrastructure, and recently it has been suggested that additional information on the pattern of damage may be obtained from axial diffusivity, a proposed marker of axonal damage, and radial diffusivity, an indicator of demyelination. We determined the contribution of these whole brain MRI markers to cognitive impairment in SVD. Consecutive patients with lacunar stroke and confluent leukoaraiosis were recruited into the ongoing SCANS study of cognitive impairment in SVD (n = 115), and underwent neuropsychological assessment and multimodal MRI. SVD subjects displayed poor performance on tests of executive function and processing speed. In the SVD group brain volume was lower, white matter hyperintensity volume higher and all diffusion characteristics differed significantly from control subjects (n = 50). On multi-predictor analysis independent predictors of executive function in SVD were lacunar infarct count and diffusivity of normal appearing white matter on DTI. Independent predictors of processing speed were lacunar infarct count and brain atrophy. Radial diffusivity was a stronger DTI predictor than axial diffusivity, suggesting ischaemic demyelination, seen neuropathologically in SVD, may be an important predictor of cognitive impairment in SVD. Our study provides information on the mechanism of cognitive impairment in SVD

In Drosophila melanogaster the COM Locus Directs the Somatic Silencing of Two Retrotransposons through both Piwi-Dependent and -Independent Pathways

BACKGROUND: In the Drosophila germ line, repeat-associated small interfering RNAs (rasiRNAs) ensure genomic stability by silencing endogenous transposable elements. This RNA silencing involves small RNAs of 26-30 nucleotides that are mainly produced from the antisense strand and function through the Piwi protein. Piwi belongs to the subclass of the Argonaute family of RNA interference effector proteins, which are expressed in the germline and in surrounding somatic tissues of the reproductive apparatus. In addition to this germ-line expression, Piwi has also been implicated in diverse functions in somatic cells. PRINCIPAL FINDINGS: Here, we show that two LTR retrotransposons from Drosophila melanogaster, ZAM and Idefix, are silenced by an RNA silencing pathway that has characteristics of the rasiRNA pathway and that specifically recognizes and destroys the sense-strand RNAs of the retrotransposons. This silencing depends on Piwi in the follicle cells surrounding the oocyte. Interestingly, this silencing is active in all the somatic tissues examined from embryos to adult flies. In these somatic cells, while the silencing still involves the strict recognition of sense-strand transcripts, it displays the marked difference of being independent of the Piwi protein. Finally, we present evidence that in all the tissues examined, the repression is controlled by the heterochromatic COM locus. CONCLUSION: Our data shed further light on the silencing mechanism that acts to target Drosophila LTR retrotransposons in somatic cells throughout fly development. They demonstrate that different RNA silencing pathways are involved in ovarian versus other somatic tissues, since Piwi is necessary for silencing in the former tissues but is dispensable in the latter. They further demonstrate that these pathways are controlled by the heterochromatic COM locus which ensures the overall protection of Drosophila against the detrimental effects of random retrotransposon mobilization

Sediment Delivery to Sustain the Ganges-Brahmaputra Delta Under Climate Change and Anthropogenic Impacts

The principal nature-based solution for offsetting relative sea-level rise in the Ganges-Brahmaputra delta is the unabated delivery, dispersal, and deposition of the rivers’ ~1 billion-tonne annual sediment load. Recent hydrological transport modeling suggests that strengthening monsoon precipitation in the 21st century could increase this sediment delivery 34-60%; yet other studies demonstrate that sediment could decline 15-80% if planned dams and river diversions are fully implemented. We validate these modeled ranges by developing a comprehensive field-based sediment budget that quantifies the supply of Ganges-Brahmaputra river sediment under varying Holocene climate conditions. Our data reveal natural responses in sediment supply comparable to previously modeled results and suggest that increased sediment delivery may be capable of offsetting accelerated sea-level rise. This prospect for a naturally sustained Ganges-Brahmaputra delta presents possibilities beyond the dystopian future often posed for this system, but the implementation of currently proposed dams and diversions would preclude such opportunities

Control of Flowering and Cell Fate by LIF2, an RNA Binding Partner of the Polycomb Complex Component LHP1

Polycomb Repressive Complexes (PRC) modulate the epigenetic status of key cell fate and developmental regulators in eukaryotes. The chromo domain protein LIKE HETEROCHROMATIN PROTEIN1 (LHP1) is a subunit of a plant PRC1-like complex in Arabidopsis thaliana and recognizes histone H3 lysine 27 trimethylation, a silencing epigenetic mark deposited by the PRC2 complex. We have identified and studied an LHP1-Interacting Factor2 (LIF2). LIF2 protein has RNA recognition motifs and belongs to the large hnRNP protein family, which is involved in RNA processing. LIF2 interacts in vivo, in the cell nucleus, with the LHP1 chromo shadow domain. Expression of LIF2 was detected predominantly in vascular and meristematic tissues. Loss-of-function of LIF2 modifies flowering time, floral developmental homeostasis and gynoecium growth determination. lif2 ovaries have indeterminate growth and produce ectopic inflorescences with severely affected flowers showing proliferation of ectopic stigmatic papillae and ovules in short-day conditions. To look at how LIF2 acts relative to LHP1, we conducted transcriptome analyses in lif2 and lhp1 and identified a common set of deregulated genes, which showed significant enrichment in stress-response genes. By comparing expression of LHP1 targets in lif2, lhp1 and lif2 lhp1 mutants we showed that LIF2 can either antagonize or act with LHP1. Interestingly, repression of the FLC floral transcriptional regulator in lif2 mutant is accompanied by an increase in H3K27 trimethylation at the locus, without any change in LHP1 binding, suggesting that LHP1 is targeted independently from LIF2 and that LHP1 binding does not strictly correlate with gene expression. LIF2, involved in cell identity and cell fate decision, may modulate the activity of LHP1 at specific loci, during specific developmental windows or in response to environmental cues that control cell fate determination. These results highlight a novel link between plant RNA processing and Polycomb regulation

DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France

We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR = 2.05, 95%CI = 1.39–3.02, p < 0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR = 0.42, 95%CI = 0.18–0.99, p = 0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon