Le pragmatisme, solution au problème moral de la modernité ?

Etude critique de Charles Larmore, Modernité et morale (Paris, PUF, 1993). Cet article présente et discute le projet de son auteur de défendre l'idée d'une morale « pragmatiste » et « intuitionniste ». Restituant la position de l'auteur, il expose les arguments en faveur d'une conception pragmatiste de la vérité morale et ceux en faveur du recours à l'intuition pour découvrir le contenu de nos obligations morales. Dans une brève note critique finale, il suggère que le pragmatisme semble peu à même d'échapper tout à fait au reproche de relativisme.

FastEpistasis: a high performance computing solution for quantitative trait epistasis.

Motivation: Genome-wide association studies have become widely used tools to study effects of genetic variants on complex diseases. While it is of great interest to extend existing analysis methods by considering interaction effects between pairs of loci, the large number of possible tests presents a significant computational challenge. The number of computations is further multiplied in the study of gene expression quantitative trait mapping, in which tests are performed for thousands of gene phenotypes simultaneously. Results: We present FastEpistasis, an efficient parallel solution extending the PLINK epistasis module, designed to test for epistasis effects when analyzing continuous phenotypes. Our results show that the algorithm scales with the number of processors and offers a reduction in computation time when several phenotypes are analyzed simultaneously. FastEpistasis is capable of testing the association of a continuous trait with all single nucleotide polymorphism ( SNP) pairs from 500 000 SNPs, totaling 125 billion tests, in a population of 5000 individuals in 29, 4 or 0.5 days using 8, 64 or 512 processors.

Critical values of nitrogen indices in tomato plants grown in soil and nutrient solution determined by different statistical procedures

The objective of this study was to establish critical values of the N indices, namely soil-plant analysis development (SPAD), petiole sap N-NO3 and organic N in the tomato leaf adjacent to the first cluster (LAC), under soil and nutrient solution conditions, determined by different statistical approaches. Two experiments were conducted in randomized complete block design with four repli-cations. Tomato plants were grown in soil, in 3 L pot, with five N rates (0, 100, 200, 400 and 800 mg kg-1) and in solution at N rates of 0, 4, 8, 12 and 16 mmol L-1. Experiments in nutrient solution and soil were finished at thirty seven and forty two days after transplanting, respectively. At those times, SPAD index and petiole sap N-NO3 were evaluated in the LAC. Then, plants were harvested, separated in leaves and stem, dried at 70ºC, ground and weighted. The organic N was determined in LAC dry matter. Three statistical procedures were used to calculate critical N values. There were accentuated discrepancies for critical values of N indices obtained with plants grown in soil and nutrient solution as well as for different statistical procedures. Critical values of nitrogen indices at all situations are presented.

Effect of amino acids and glucose on exercise-induced gut and skeletal muscle proteolysis in dogs.

The effect of amino acid and/or glucose administration before and during exercise on protein metabolism in visceral tissues and skeletal muscle was examined in mongrel dogs. The dogs were subjected to treadmill running (150 minutes at 10 km/h and 12% incline) and intravenously infused with a solution containing amino acids and glucose (AAG), amino acids (AA), glucose (G) or saline (S) in randomized order. The infusion was started 60 minutes before exercise and continued until the end of the exercise period. An arteriovenous-difference technique was used to estimate both tissue protein degradation and synthesis. When S was infused, the release of leucine (Leu) from the gut and phenylalanine (Phe) from the hindlimb significantly increased during exercise, thus indicating that exercise augmented proteolysis in these tissues. The balance of Leu across the gut during exercise demonstrated a net uptake with both AAG and AA, whereas a net release was observed for G and S. In addition, Leu uptake in the gut during the last 90 minutes of the exercise period tended to be greater with AAG versus AA (P = .06). Phe balance across the hindlimb during the late exercise period showed a significant release with S, AA, and G, whereas the balance with AAG did not show a significant release. These results suggest that exercise-induced proteolysis in the gut may be reduced by supplementation with AA, and this effect may be enhanced by concomitant G administration. However, in skeletal muscle, both AA and G may be required to prevent net protein degradation during exercise. G provided without AA did not achieve net protein synthesis in either tissue.

Pattern-based sensing of nucleotides in aqueous solution with a multicomponent indicator displacement assay

A multicomponent indicator displacement assay ( MIDA) based on an organometallic receptor and three dyes can be used for the identification and quantification of nucleotides in aqueous solution at neutral pH.

Exotic terrains in the Alps - A solution for a single Jurassic ocean

The Brianconnais area is explained as a large scale exotic terrain separating from Europe during the opening of the Valais ocean. It's displacement history during the Alpine evolution allows to replace older concepts of multiple oceans separating narrow strips of continental crust.

Cadmium-free quantum dots in aqueous solution: potential for fingermark detection, synthesis and an application to the detection of fingermarks in blood on non-porous surfaces

The use of quantum dots (QDs) in the area of fingermark detection is currently receiving a lot of attention in the forensic literature. Most of the research efforts have been devoted to cadmium telluride (CdTe) quantum dots often applied as powders to the surfaces of interests. Both the use of cadmium and the nano size of these particles raise important issues in terms of health and safety. This paper proposes to replace CdTe QDs by zinc sulphide QDs doped with copper (ZnS:Cu) to address these issues. Zinc sulphide-copper doped QDs were successfully synthesized, characterized in terms of size and optical properties and optimized to be applied for the detection of impressions left in blood, where CdTe QDs proved to be efficient. Effectiveness of detection was assessed in comparison with CdTe QDs and Acid Yellow 7 (AY7, an effective blood reagent), using two series of depletive blood fingermarks from four donors prepared on four non-porous substrates, i.e. glass, transparent polypropylene, black polyethylene and aluminium foil. The marks were cut in half and processed separately with both reagents, leading to two comparison series (ZnS:Cu vs. CdTe, and ZnS:Cu vs. AY7). ZnS:Cu proved to be better than AY7 and at least as efficient as CdTe on most substrates. Consequently, copper-doped ZnS QDs constitute a valid substitute for cadmium-based QDs to detect blood marks on non-porous substrates and offer a safer alternative for routine use.

Spatial visualization of DNA in solution.

An image analysis method is presented which allows for the reconstruction of the three-dimensional path of filamentous objects from two of their projections. Starting with stereo pairs, this method is used to trace the trajectory of DNA molecules embedded in vitreous ice and leads to a faithful representation of their three-dimensional shape in solution. This computer-aided reconstruction is superior to the subjective three-dimensional impression generated by observation of stereo pairs of micrographs because it enables one to look at the reconstructed molecules from any chosen direction and distance and allows quantitative analysis such as determination of distances, curvature, persistence length, and writhe of DNA molecules in solution.

Seed priming and sulfur effects on soybean cell membrane stability and yield in saline soil

The objective of this work was to determine the effects of seed priming and sulfur application on cell membrane characteristics, seedling emergence, chlorophyll content and grain yield of soybean (Glycine max) in saline soil. A complete-block design in 4x3 factorial arrangement with three replicates was used to test four types of seed priming (water, auxin, gibberellin and non-priming) and three levels of sulfate availability (0, 70 and 140 kg ha-1 K2SO4). The soil had a silty loam texture with an electrical conductivity of 3.61 ds m-1, a pH of 8.2 and a saturation percentage of about 46%. Seed priming had significant effects on mean emergence rate (MER), emergence percentage, relative water content (RWC) of leaves, relative chlorophyll content, time of maturity, shoot length and grain yield. The highest values for these variables were observed in the priming treatments, except for the time of maturity. Sulfur application had significant effects on MER, shoot length, RWC, membrane injury index and grain yield. Priming treatments provide greater emergence rates and grain yields and interact sinergicaly with sulfur rates.

Développement d'une solution orale pédiatrique de captopril

Introduction: Le captopril, inhibiteur de l'enzyme de conversion de l'angiotensine, est largement utilisé dans le traitement de l'hypertension artérielle et de l'insuffisance cardiaque chez l'adulte et l'enfant . De par son instabilité en milieu aqueux (oxydation en captopril disulfure), il n'est actuellement commercialisé que sous forme de comprimés. La prescription fréquente de doses faibles et variables en pédiatrie justifiait le développement d'une forme orale liquide, tant sur le plan pratique et économique, que sur celui de la sécurité d'administration. Cependant toutes les formulations orales liquides publiées présentent une stabilité courte, ne dépassant guère 1 mois. Objectif: Développer une forme orale liquide de captopril d'une stabilité d'au moins 6 mois. Méthode: Sur la base des données de la littérature, élaboration de 8 formulations liquides différentes de captopril 1 mg/ml (concentration permettant le prélèvement d'un volume adéquat pour une administration en pédiatrie). Mise au point d'une « stability indicating method » par HPLC par des tests de dégradation accélérée à la chaleur (100°C), en milieu acide, basique, en présence d'un agent oxydant et de la lumière. Sélection de la formulation la plus stable durant le premier mois. Etude de stabilité sur 2 ans de 3 lots (3 échantillons/lot) dans leur conditionnement final à température ambiante (TA), au frigo et à 40° ± 2°C. Contrôle microbiologique au début et à la fin de l'étude selon la méthode de la Ph. Eur. (Ed. 3). Résultats: La formule retenue est une solution aqueuse de captopril 1 mg/ml additionnée d'EDTA 1 mg/ml comme stabilisateur et conditionnée dans des flacons VERAL en verre brun de 60 ml. Après dégradation dans les conditions définies ci-dessus, le pic du captopril est nettement séparé sur les chromatogrammes de ceux des produits de dégradation. Après 2 ans, la concentration mesurée est de 104.6% (±0.32%) au frigo, 103.6% (±0.86%) à TA et 96.5 % (±0.02%) à 40°C. Aucune croissance n'a été observée sur la durée de l'étude. Discussion et conclusion: La solution de captopril 1 mg/ml mise au point est simple à préparer. En partant du principe actif pur et en présence d'EDTA comme complexant, les traces de métaux éventuellement présents n'induisent pas l'oxydation du captopril et par conséquent le recours à d'autres stabilisateurs n'est pas nécessaire. La méthode HPLC développée est une « stability indicating method ». Les résultats de l'étude ont montré que cette solution a une durée de validité de 2 ans au frigo et à TA. Compte tenu du fait que la préparation ne contient pas d'agent antimicrobien, une conservation au frigo (2 - 8°C) est toutefois recommandée. La formule proposée présente un réel avantage en pédiatrie tant sur le plan de la sécurité d'administration que sur celui de l'économie.