Mesozoic biostratigraphic, paleoenvironmental, and paleobiogeographic synthesis, equatorial Atlantic

Cretaceous sediments from Ocean Drilling Program Leg 159 on the Côte d’Ivoire-Ghana Marginal Ridge (CIGMR), eastern equatorial Atlantic, are characterized by distinct stratigraphic changes in sedimentary facies associated with changes in the composition of the clayey and organic fractions, as well as of the calcareous nannofossil, radiolarian, foraminiferal, and palynomorph assemblages. In the absence of reliable magnetostratigraphic information, an integrated biostratigraphy provides the only means used to calibrate the geologic history of the Leg 159 area. The existence of marine depositional environments as early as the late Aptian to early Albian close to the Leg 159 drill sites puts constraints on the timing of the opening of the equatorial Atlantic gateway. Marine sedimentation on the ridge suggests that the West African and South American cratons were largely detached at this segment of the margin by the middle to late Albian. During the Cenomanian to Coniacian the ridge appears to have remained in an elevated position with concurrent low deposition or condensation (Site 959), high carbonate debris accumulation (Site 960), and even erosion (Site 962). Total organic Carbon measurements and microfaunal data lead us to suggest that, following the early opening of the seaway during the Albian, circulation remained restricted in the fragmented sub-basins of the CIGMR. It probably was not until the Santonian that a deep-water connection and circulation system became established between the Central and the South Atlantic. The sedimentary and faunal record at Site 959 show that a rapid subsidence occurred during the Santonian, with sub-calcite compensation depth conditions maintained until and beyond the Cretaceous/Tertiary boundary

Mise au point d'un outil d'aide à la décision dans le domaine du risque sismique. Démarche expérimentale d'appropriation de la problématique des risques par les acteurs d'une collectivité urbaine (RP-50020-FR )

Référence : BRGM/RP-50020-FRRapport commandité par la Région Rhône-AlpesSynthèse Le risque naturel est une réalité pour de nombreuses collectivités et leurs services techniques ne l'ignorent pas. Toutefois les acteurs susceptibles d'y être confrontés, et d'en améliorer la prévention, tels que les entreprises, les populations ou les gouvernants ne l'ont pas toujours intégré. En effet, les problèmes sociaux, économiques ou politiques sont parfois plus préoccupants pour les responsables d'une collectivité qui laissent la prise en compte du risque naturel à la charge des responsables de la sécurité. Pourtant, un évènement sismique faible peut avoir des conséquences sociales ou économiques : des populations à faibles revenus peuvent être déplacées à la suite de rénovations entraînant une hausse de l'immobilier, de même que des entreprises peuvent être pénalisées par la perturbation de réseaux de télécommunication ou l'affectation de leurs salariés. Pour que le risque soit pris en compte par tous les acteurs d'une collectivité, il doit donc leur être présenté selon leur culture et doit être intégré dans le cadre de leurs préoccupations. Faut-il pour parler du risque, développer autant de discours qu'il y a d'acteurs ? Probablement non, car si les acteurs sont multiples ils appartiennent néanmoins tous à la collectivité et celle-ci n'a qu'une échelle de valeurs. C'est selon ce principe que la recherche a été menée. Réalisée dans le cadre du programme de recherche " Génie urbain et environnement ", financé par le contrat de plan Etat-Région Rhône Alpes 1994-1999, elle a pour objectif de définir une méthode permettant l'appropriation de la problématique du risque par les acteurs d'une collectivité territoriale. L'application pratique de cette recherche a été effectuée avec l'appui du district annécien. Cette recherche a nécessité l'association de compétences dans le domaine des risques, des aléas et des enjeux ainsi que dans celui de l'identification des Cohérences culturelles d'une collectivité. Elle est le résultat des travaux menés conjointement par le BRGM, l'Institut Cohérences, Nicaya et l'Université de Savoie. La recherche a porté sur l'appréhension de la problématique du risque par les différents acteurs, les conditions culturelles de l'appropriation active et sur les conditions du partage de la connaissance et de la compréhension. La mise en oeuvre des connaissances, à travers des décisions communes et la recherche collective de solutions n'a pas été abordée dans ce travail

Once-daily budesonide MMX in active, mild-to-moderate ulcerative colitis: results from the randomised CORE II study.

OBJECTIVE: Budesonide MMX is a novel oral formulation of budesonide that uses Multi-Matrix System (MMX) technology to extend release to the colon. This study compared the efficacy of budesonide MMX with placebo in patients with active, mild-to-moderate ulcerative colitis (UC). DESIGN: Patients were randomised 1:1:1:1 to receive budesonide MMX 9 mg or 6 mg, or Entocort EC 9 mg (budesonide controlled ileal-release capsules; reference arm) or placebo once daily for 8 weeks. The primary endpoint was combined clinical and endoscopic remission, defined as UC Disease Activity Index score ≤1 with a score of 0 for rectal bleeding and stool frequency, no mucosal friability on colonoscopy, and a ≥1-point reduction in endoscopic index score from baseline. RESULTS: 410 patients were evaluated for efficacy. Combined clinical and endoscopic remission rates with budesonide MMX 9 mg or 6 mg, Entocort EC and placebo were 17.4%, 8.3%, 12.6% and 4.5%, respectively. The difference between budesonide MMX 9 mg and placebo was significant (OR 4.49; 95% CI 1.47 to 13.72; p=0.0047). Budesonide MMX 9 mg was associated with numerically higher rates of clinical (42.2% vs 33.7%) and endoscopic improvement (42.2% vs 31.5%) versus placebo. The rate of histological healing (16.5% vs 6.7%; p=0.0361) and proportion of patients with symptom resolution (23.9% vs 11.2%; p=0.0220) were significantly higher for budesonide MMX 9 mg than placebo. Adverse event profiles were similar across groups. CONCLUSION: Budesonide MMX 9 mg was safe and more effective than placebo at inducing combined clinical and endoscopic remission in patients with active, mild-to-moderate UC

Frequency of intravascular catheter colonization by Malassezia spp. in adult patients

International audienceColonization of intravascular catheters (IVCs) with lipid-dependent Malassezia spp. is rarely reported in adult patients probably because of the absence of additional lipids in routine culture media. Therefore, we systematically seeded 983 consecutive IVC onto Dixon medium compatible with the growth of Malassezia spp. Seven (0.7%) IVCs were positive. Six of them were from surgical patients. Four of them also yielded common bacteria. Identification using PCR-RFLP and restriction enzymes yielded M. furfur and M. sympodialis. Colonization of IVCs with Malassezia spp. does not appear negligible and warrants additional studies to evaluate the clinical relevance of such findings and the role of this yeast in biofilm formation

The first cysteine-rich domain of the receptor GFRα1 stabilizes the binding of GDNF

The GDNF (glial cell line-derived neurotrophic factor)-binding receptor GFRα1 (GDNF family receptor α1) is attached to the membrane by a GPI (glycosylphosphatidylinositol) anchor and consists of three cysteine-rich domains. The region corresponding to the second and third domains has been shown previously to participate in ligand binding, and to interact with the transmembrane tyrosine kinase receptor RET. No function has so far been found for the N-terminal, first domain (D1). Here we show that the GPI-anchored full-length receptor binds (125)I-GDNF two times more tightly than does a GPI-anchored truncated receptor lacking D1. Scintillation proximity assays with purified receptor proteins also show that the GDNF-binding capacity of the soluble full-length GFRα1 is two times higher than the GDNF-binding capacity of the soluble D1-truncated GFRα1. As RET stabilizes the binding of GDNF equally well to the full-length and truncated receptors, D1 seems not to be involved in the interaction between GFRα1 and RET. Moreover, soluble full-length GFRα1 mediates GDNF-promoted neurite outgrowth in PC6-3 cells more efficiently than the soluble truncated GFRα1 protein. At low concentrations, the soluble fulllength receptor mediates the phosphorylation of RET more efficiently than the soluble truncated receptor. However, when the receptors are overexpressed on the cell surface as GPI-anchored proteins, or added to the growth medium at high concentrations as soluble proteins, full-length and truncated GFRα1 are indistinguishable in GDNF-dependent RET-phosphorylation assays. High levels of the receptors can thus mask a slightly impaired function in the phosphorylation assay. Based on assays with both GPI-anchored and soluble receptors, we therefore conclude that D1 contributes to the optimal function of GFRα1 by stabilizing the interaction between GFRα1 and GDNF

Early stages of crop expansion have little effect on farm-scale vegetation patterns in a Cerrado biome working landscape

International audienceIn addition to protected areas, sustainable working landscapes are key to successful biodiversity conservation. Yet such landscapes are threatened by rapid crop expansion, in particular in Brazil. In this context, this study explores the influence of farming systems on farm-scale vegetation patterns around the Serra da Bodoquena National Park in Mato Grosso do Sul. To collect data on farming systems and how they are evolving, we conducted interviews at 40 farms covering 120,000 ha, including eight farms with land within the national park. To assess vegetation patterns, we conducted pixel-wise and landscape analyses based on MapBiomas land cover maps from which we calculated seven metrics over the 2009-2019 period. Using multivariate methods, we identified the activities that differentiated farming systems, isolating five farm types with contrasting involvement in crop cultivation and ranching. We found that most farm-scale landscape metrics were only weakly influenced by farming systems. Temporal analyses and interviews suggested that biophysical and legislative contexts limit crop expansion, which mainly occurred at the expense of old pastures and did not directly impact forest proportion within farms. As a consequence, crop expansion in the region seemed to mainly affect small tree patches in pasture areas, making its effect on vegetation patterns barely detectable with 30-m resolution imagery. These findings suggest that rather than focusing solely on deforestation, monitoring the dynamics of wooded pastures with high-resolution images is crucial to assess the early effects of crop expansion on vegetation patterns and to ensure the conservation of biodiversity-friendly agricultural matrices around protected areas in Brazil