1,954 research outputs found

    De la responsabilité sociale des acteurs

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    Nous montrons ici, sans prétendre à l’exhaustivité, quels sont, au-delà des (grandes) entreprises, les autres acteurs intéressés à réclamer leur part de responsabilité vis-à-vis du développement durable. Nous nous demandons quelles sont leurs motivations, leurs objectifs et leurs moyens d’action, et si ces moyens sont les mêmes pour tous les acteurs. Le mouvement de revendication d’une responsabilité de la part de nombreux acteurs est replacé dans le cadre plus général des évolutions (économiques, sociales, environnementales, géopolitiques, etc.) des trente dernières années. La première section de cet article explique l’émergence de la notion de responsabilité des acteurs (RSA), clarifie les relations entre RSA et développement durable, puis montre les variantes géographiques de la RSA. La seconde section s’attache aux différents acteurs de la RSA et compare leurs objectifs et moyens d’action

    Thiomorpholino oligonucleotides as a robust class of next generation platforms for alternate mRNA splicing

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    Recent advances in drug development have seen numerous successful clinical translations using synthetic antisense oligonucleotides (ASOs). However, major obstacles, such as challenging large-scale production, toxicity, localization of oligonucleotides in specific cellular compartments or tissues, and the high cost of treatment, need to be addressed. Thiomorpholino oligonucleotides (TMOs) are a recently developed novel nucleic acid analog that may potentially address these issues. TMOs are composed of a morpholino nucleoside joined by thiophosphoramidate internucleotide linkages. Unlike phosphorodiamidate morpholino oligomers (PMOs) that are currently used in various splice-switching ASO drugs, TMOs can be synthesized using solid-phase oligonucleotide synthesis methodologies. In this study, we synthesized various TMOs and evaluated their efficacy to induce exon skipping in a Duchenne muscular dystrophy (DMD) in vitro model using H2K mdx mouse myotubes. Our experiments demonstrated that TMOs can efficiently internalize and induce excellent exon 23 skipping potency compared with a conventional PMO control and other widely used nucleotide analogs, such as 2′-O-methyl and 2′-O-methoxyethyl ASOs. Notably, TMOs performed well at low concentrations (5–20 nM). Therefore, the dosages can be minimized, which may improve the drug safety profile. Based on the present study, we propose that TMOs represent a new, promising class of nucleic acid analogs for future oligonucleotide therapeutic development

    Water use efficiency and yield of winter wheat under different irrigation regimes in a semi-arid region

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    In irrigation schemes under rotational water supply in semi-arid region, the water allocation and irrigation scheduling are often based on a fixed-area proportionate water depth with every irrigation cycle irrespective of crops and their growth stages, for an equitable water supply. An experiment was conducted during the 2004- 2005 season in Haouz irrigated area in Morocco, which objective was 1) to evaluate the effects of the surface irrigation scheduling method (ex-isting rule) adopted by the irrigation agency on winter wheat production compared to a full ir-rigation method and 2) to evaluate drip irrigation versus surface irrigation impacts on water sav-ing and yield of winter wheat. The methodology was based on the FAO-56 dual approach for the surface irrigation scheduling. Ground measure- ments of the Normalized Difference Vegetation Index (NDVI) were used to derive the basal crop coefficient and the vegetation fraction cover. The simple FAO-56 approach was used for drip irrigation scheduling. For surface irrigation, the existing rule approach resulted in yield and WUE reductions of 22% and 15%, respectively, compared with the optimized irrigation sched-uling proposed by the FAO-56 for full irrigation treatment. This revealed the negative effects of the irrigation schedules adopted in irrigation schemes under rotational water supply on crops productivity. It was also demonstrated that drip irrigation applied to wheat was more efficient with 20% of water saving in comparison with surface irrigation (full irrigation treatment). Drip irrigation gives also higher wheat yield com-pared to surface irrigation (+28% and +52% for full irrigation and existing rule treatments re-spectively). The same improvement was ob-served for water use efficiency (+24% and +59% respectively)

    Multi frequency evaporative cooling to BEC in a high magnetic field

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    We demonstrate a way to circumvent the interruption of evaporative cooling observed at high bias field for 87^{87}Rb atoms trapped in the (F=2, m=+2) ground state. Our scheme uses a 3-frequencies-RF-knife achieved by mixing two RF frequencies. This compensates part of the non linearity of the Zeeman effect, allowing us to achieve BEC where standard 1-frequency-RF-knife evaporation method did not work. We are able to get efficient evaporative cooling, provided that the residual detuning between the transition and the RF frequencies in our scheme is smaller than the power broadening of the RF transitions at the end of the evaporation ramp.Comment: 12 pages, 2 figure

    A nonextensive approach to Bose-Einstein condensation of trapped interacting boson gas

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    In the Bose-Einstein condensation of interacting atoms or molecules such as 87Rb, 23Na and 7Li, the theoretical understanding of the transition temperature is not always obvious due to the interactions or zero point energy which cannot be exactly taken into account. The S-wave collision model fails sometimes to account for the condensation temperatures. In this work, we look at the problem within the nonextensive statistics which is considered as a possible theory describing interacting systems. The generalized energy Uq and the particle number Nq of boson gas are given in terms of the nonextensive parameter q. q>1 (q<1) implies repulsive (attractive) interaction with respect to the perfect gas. The generalized condensation temperature Tcq is derived versus Tc given by the perfect gas theory. Thanks to the observed condensation temperatures, we find q ~ 0.1 for 87Rb atomic gas, q ~ 0.95 for 7Li and q ~ 0.62 for 23Na. It is concluded that the effective interactions are essentially attractive for the three considered atoms, which is consistent with the observed temperatures higher than those predicted by the conventional theory

    Comment passer d'un modèle hydrologique à un système de prévision des crues? Ecueils liés à la structure des modèles et aux échelles d'espace et de temps

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    Les modèles hydrologiques Pluie Débit sont des outils très utiles pour la prévision des crues. À l'heure actuelle, il n'est pas possible d'utiliser directement les modèles de simulation pour effectuer une bonne prévision. Nous explorons ici les différences entre modèles de simulation et modèles de prévision. Puis nous examinons l'importance relative des informations apportées au modèle : dans le passé, les forçages climatiques et les dernières observations de débit ; dans le futur, les prévisions de précipitations. La question des échelles spatiales est ensuite abordée et les limites d'une approche globale sont discutées dans une perspective opérationnelle. / Rainfall Runoff models are very useful tools for flood forecasting. As of today, the direct use of simulation models is not possible to get accurate predictions especially when it concerns short-term forecasting. In this paper, we explore the main differences between simulation and forecasting models. Then we assess the relative importance of every information provided to the model: the past climatic forcing and the last observed discharges; the future precipitation scenarios. Spatial scales are also examined and the limits of a global forecasting approach for operational purposes are discussed

    Purification from human plasma of a tetrapeptide that potentiates insulin-like growth factor-I activity in chick embryo cartilage

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    AbstractHuman plasma has been shown to contain a low molecular weight factor that potentiates human IGF-I stimulation of glycosaminoglycan synthesis in chick embryo cartilage. The peptide was purified and characterized by Edman degradation and electrospray mass spectrometry. The primary structure determined was: Trp-Gly-His-Glu. A homologous synthetic peptide similarly promoted matrix biosynthesis in cartilage exposed to IGF-1

    Attentional Patterns Involved in Coping Strategies in a Sport Context

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    We investigated the relationship between coping strategies and attentional bias after a sport competition. We administered the Ways of Coping Checklist (Paulhan, Nuissier, Quintard, Cousson, &amp; Bourgeois, 1994) to 145 athletes immediately after they had participated in a sport competition. We also assessed attentional bias using a dot probe detection task. Results revealed that emotion-focused coping strategies led athletes to orient their attention away from threat, whereas athletes who adopted problem-focused coping strategies focused their attention toward threat. More precisely, problem-focused coping strategies are related to a facilitated detection of threat, not to disengagement difficulties. The vigilance attentional bias seems to be a compensatory strategy to cope with a stressful situation, such as sport competition. (Contains 1 table.
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