224 research outputs found

    Application of rock engineering systems to large-scale confined destress blasts in underground mine pillars

    Get PDF
    Cette thĂšse dĂ©crit le dĂ©veloppement d’une nouvelle mĂ©thodologie qui quantifie les chances de succĂšs d’un tir confinĂ© Ă  grande Ă©chelle de relĂąchement des contraintes dans un pilier de mine souterraine, pour une masse rocheuse et un rĂ©gime de contraintes donnĂ©s. L’approche est basĂ©e sur huit paramĂštres qui sont considĂ©rĂ©s comme contrĂŽlant ultimement le processus, et dont l’influence et les interactions ont Ă©tĂ© quantifiĂ©es dans un premier temps avec la mĂ©thode des SystĂšmes d’ingĂ©nierie du roc (“Rock Engineering Systems”). Ces interactions et degrĂ©s d’influence ont ensuite Ă©tĂ© utilisĂ©s pour Ă©laborer la nouvelle mĂ©thodologie, qui est basĂ©e sur un nouveau paramĂštre appelĂ© l’Indice de relĂąchement, qui peut ĂȘtre ‘Faible’, ‘Moyen’, ‘Bon’ ou ‘Excellent’. Il est conclu que cette mĂ©thodologie a une valeur pratique Ă©levĂ©e de par sa capacitĂ© Ă  concevoir adĂ©quatement un tir confinĂ© Ă  grande Ă©chelle de relĂąchement des contraintes dans un pilier de mine, en prenant simplement des mesures qui rĂ©sultent en une augmentation de l’Indice de relĂąchement et, donc, des chances de succĂšs du ti

    Structural Basis for the Association of MAP6 Protein with Microtubules and Its Regulation by Calmodulin: Microtubule and calmodulin binding on Mn modules of MAP6

    Get PDF
    International audienceMicrotubules are highly dynamic αÎČ-tubulin polymers. In vitro and in living cells, microtubules are most often cold- and nocodazole-sensitive. When present, the MAP6/STOP family of proteins protects microtubules from cold- and nocodazole-induced depolymerization but the molecular and structure determinants by which these proteins stabilize microtubules remain under debate. We show here that a short protein fragment from MAP6-N, which encompasses its Mn1 and Mn2 modules (MAP6(90-177)), recapitulates the function of the full-length MAP6-N protein toward microtubules, i.e. its ability to stabilize microtubules in vitro and in cultured cells in ice-cold conditions or in the presence of nocodazole. We further show for the first time, using biochemical assays and NMR spectroscopy, that these effects result from the binding of MAP6(90-177) to microtubules with a 1:1 MAP6(90-177):tubulin heterodimer stoichiometry. NMR data demonstrate that the binding of MAP6(90-177) to microtubules involve its two Mn modules but that a single one is also able to interact with microtubules in a closely similar manner. This suggests that the Mn modules represent each a full microtubule binding domain and that MAP6 proteins may stabilize microtubules by bridging tubulin heterodimers from adjacent protofilaments or within a protofilament. Finally, we demonstrate that Ca(2+)-calmodulin competes with microtubules for MAP6(90-177) binding and that the binding mode of MAP6(90-177) to microtubules and Ca(2+)-calmodulin involves a common stretch of amino acid residues on the MAP6(90-177) side. This result accounts for the regulation of microtubule stability in cold condition by Ca(2+)-calmodulin

    From modelling of a CDMA transceiver in indoor environment to an ASIC circuit synthesis, Journal of Telecommunications and Information Technology, 2001, nr 3

    Get PDF
    This paper presents the study, design and simulation of a multi-flow radio frequency transceiver based on a direct sequence spread-spectrum with a 2.4 GHz carrier. First, the functional model of differential QPSK modulation for digital transmission, and the different parts making up spread spectrum function (spreader, despreader, tracking and synchronising devices) have been studied, implemented, simulated and validated in noisy multi-users and multi-path environment by using a unified language. The results obtained by taking into account the home automation running constraints have allowed to determine some critical parameter values and so to integrate the digital functions in an ASIC circuit

    Clinical and molecular characterization of 17q21.31 microdeletion syndrome in 14 French patients with mental retardation.

    Get PDF
    International audienceChromosome 17q21.31 microdeletion was one of the first genomic disorders identified by chromosome microarrays. We report here the clinical and molecular characterization of a new series of 14 French patients with this microdeletion syndrome. The most frequent clinical features were hypotonia, developmental delay and facial dysmorphism, but scaphocephaly, prenatal ischemic infarction and perception deafness were also described. Genotyping of the parents showed that the parent from which the abnormality was inherited carried the H2 inversion polymorphism, confirming that the H2 allele is necessary, but not sufficient to generate the 17q21.31 microdeletion. Previously reported molecular analyses of patients with 17q21.31 microdeletion syndrome defined a 493 kb genomic fragment that was deleted in most patients after taking into account frequent copy number variations in normal controls, but the deleted interval was significantly smaller (205 kb) in one of our patients, encompassing only the MAPT, STH and KIAA1267 genes. As this patient presents the classical phenotype of 17q21.31 syndrome, these data make it possible to define a new minimal critical region of 160.8 kb, strengthening the evidence for involvement of the MAPT gene in this syndrome

    Mutations in TUBG1, DYNC1H1, KIF5C and KIF2A cause malformations of cortical development and microcephaly.

    Get PDF
    International audienceThe genetic causes of malformations of cortical development (MCD) remain largely unknown. Here we report the discovery of multiple pathogenic missense mutations in TUBG1, DYNC1H1 and KIF2A, as well as a single germline mosaic mutation in KIF5C, in subjects with MCD. We found a frequent recurrence of mutations in DYNC1H1, implying that this gene is a major locus for unexplained MCD. We further show that the mutations in KIF5C, KIF2A and DYNC1H1 affect ATP hydrolysis, productive protein folding and microtubule binding, respectively. In addition, we show that suppression of mouse Tubg1 expression in vivo interferes with proper neuronal migration, whereas expression of altered Îł-tubulin proteins in Saccharomyces cerevisiae disrupts normal microtubule behavior. Our data reinforce the importance of centrosomal and microtubule-related proteins in cortical development and strongly suggest that microtubule-dependent mitotic and postmitotic processes are major contributors to the pathogenesis of MCD

    Development and validation of an interpretable machine learning-based calculator for predicting 5-year weight trajectories after bariatric surgery: a multinational retrospective cohort SOPHIA study

    Full text link
    Background Weight loss trajectories after bariatric surgery vary widely between individuals, and predicting weight loss before the operation remains challenging. We aimed to develop a model using machine learning to provide individual preoperative prediction of 5-year weight loss trajectories after surgery. Methods In this multinational retrospective observational study we enrolled adult participants (aged ≄\ge18 years) from ten prospective cohorts (including ABOS [NCT01129297], BAREVAL [NCT02310178], the Swedish Obese Subjects study, and a large cohort from the Dutch Obesity Clinic [Nederlandse Obesitas Kliniek]) and two randomised trials (SleevePass [NCT00793143] and SM-BOSS [NCT00356213]) in Europe, the Americas, and Asia, with a 5 year followup after Roux-en-Y gastric bypass, sleeve gastrectomy, or gastric band. Patients with a previous history of bariatric surgery or large delays between scheduled and actual visits were excluded. The training cohort comprised patients from two centres in France (ABOS and BAREVAL). The primary outcome was BMI at 5 years. A model was developed using least absolute shrinkage and selection operator to select variables and the classification and regression trees algorithm to build interpretable regression trees. The performances of the model were assessed through the median absolute deviation (MAD) and root mean squared error (RMSE) of BMI. Findings10 231 patients from 12 centres in ten countries were included in the analysis, corresponding to 30 602 patient-years. Among participants in all 12 cohorts, 7701 (75∙\bullet3%) were female, 2530 (24∙\bullet7%) were male. Among 434 baseline attributes available in the training cohort, seven variables were selected: height, weight, intervention type, age, diabetes status, diabetes duration, and smoking status. At 5 years, across external testing cohorts the overall mean MAD BMI was 2∙\bullet8 kg/m2{}^2 (95% CI 2∙\bullet6-3∙\bullet0) and mean RMSE BMI was 4∙\bullet7 kg/m2{}^2 (4∙\bullet4-5∙\bullet0), and the mean difference between predicted and observed BMI was-0∙\bullet3 kg/m2{}^2 (SD 4∙\bullet7). This model is incorporated in an easy to use and interpretable web-based prediction tool to help inform clinical decision before surgery. InterpretationWe developed a machine learning-based model, which is internationally validated, for predicting individual 5-year weight loss trajectories after three common bariatric interventions.Comment: The Lancet Digital Health, 202

    Prebiotics from Marine Macroalgae for Human and Animal Health Applications

    Get PDF
    The marine environment is an untapped source of bioactive compounds. Specifically, marine macroalgae (seaweeds) are rich in polysaccharides that could potentially be exploited as prebiotic functional ingredients for both human and animal health applications. Prebiotics are non-digestible, selectively fermented compounds that stimulate the growth and/or activity of beneficial gut microbiota which, in turn, confer health benefits on the host. This review will introduce the concept and potential applications of prebiotics, followed by an outline of the chemistry of seaweed polysaccharides. Their potential for use as prebiotics for both humans and animals will be highlighted by reviewing data from both in vitro and in vivo studies conducted to date
    • 

    corecore