531 research outputs found

    Impact des éléments de gouvernement d'entreprise sur le contenu informationnel des accruals discrétionnaires cas du contexte Français.

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    L'objet de cet article est de tester l'effet de la qualité du gouvernement d'entreprise sur le contenu informationnel des accruals discrétionnaires sur des sociétés non financiÚres du SBF 250. Pour approcher le concept de gouvernement d'entreprise qui recouvre plusieurs dimensions à savoir : le conseil d'administration et ses comités, nous avons utilisé la méthode de l'analyse de l'enveloppement des données (AED). Les résultats indiquent que la qualité du de gouvernement d'entreprise affecte le contenu informationnel des accruals discrétionnaires. Plus loin, la qualité du gouvernement d'entreprise affecte la capacité prédictive des accruals discrétionnaires.accruals discrétionnaires; gouvernement d'entreprise; indices de gouvernance

    Identification and correction of systematic error in high-throughput sequence data

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    A feature common to all DNA sequencing technologies is the presence of base-call errors in the sequenced reads. The implications of such errors are application specific, ranging from minor informatics nuisances to major problems affecting biological inferences. Recently developed “next-gen” sequencing technologies have greatly reduced the cost of sequencing, but have been shown to be more error prone than previous technologies. Both position specific (depending on the location in the read) and sequence specific (depending on the sequence in the read) errors have been identified in Illumina and Life Technology sequencing platforms. We describe a new type of _systematic_ error that manifests as statistically unlikely accumulations of errors at specific genome (or transcriptome) locations. We characterize and describe systematic errors using overlapping paired reads form high-coverage data. We show that such errors occur in approximately 1 in 1000 base pairs, and that quality scores at systematic error sites do not account for the extent of errors. We identify motifs that are frequent at systematic error sites, and describe a classifier that distinguishes heterozygous sites from systematic error. Our classifier is designed to accommodate data from experiments in which the allele frequencies at heterozygous sites are not necessarily 0.5 (such as in the case of RNA-Seq). Systematic errors can easily be mistaken for heterozygous sites in individuals, or for SNPs in population analyses. Systematic errors are particularly problematic in low coverage experiments, or in estimates of allele-specific expression from RNA-Seq data. Our characterization of systematic error has allowed us to develop a program, called SysCall, for identifying and correcting such errors. We conclude that correction of systematic errors is important to consider in the design and interpretation of high-throughput sequencing experiments

    Rétention des ions Plomb (II) en milieu acide par ultrafiltration assistée par les micelles

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    L'ultrafiltration assistĂ©e par les micelles (UFAM) a Ă©tĂ© utilisĂ©e pour la rĂ©cupĂ©ration des ions plomb (II) en milieu acide (Phosphorique et perchlorique) Ă  la tempĂ©rature 318K. Le dodĂ©cylsulfate de sodium (SDS) a Ă©tĂ© choisi comme agent tensioactif. Des taux de rĂ©tention de 99% ont Ă©tĂ© obtenus dans des conditions optimales de pression, de concentration en SDS, de vitesse de circulation du fluide et de pourcentage du volume filtrĂ©. L'Ă©quilibre d'Ă©change ionique qui s'effectue entre le contre ion de la micelle et le cation mĂ©tallique ajoutĂ© (Pb2+), a Ă©tĂ© caractĂ©risĂ© par une contante Ke(Na+/Pb2+)=1,39. Afin d'Ă©tudier la performance de l'UFAM dans les milieux acides, l'Ă©tude a Ă©tĂ© effectuĂ©e Ă  concentration de Pb(II) constante et en variant le pH. À des pH supĂ©rieurs Ă  1,8 la rĂ©tention est supĂ©rieure Ă  95%.The increasing contamination of urban and industrial waste water by toxic metal ions is a worrying environmental problem. These inorganic micro-pollutants are of considerable concern because they are non-biodegradable, highly toxic and in some cases have a probable carcinogenic effect. If directly discharged into the sewage system they may seriously affect the operation of biological treatment systems and render the activated sludge unsuitable for application to agricultural land.The traditional techniques for the removal of metal ions from aqueous effluents are incapable of reducing concentrations to the levels required by law (reduction or lime precipitation) or prohibitively expensive (ion exchange, activated carbon adsorption or electrolytic removal). The use of membrane separation processes to treat waste water containing toxic metal ions is today an attractive and suitable technique, and it can easily be included in the process, which is the reason why membrane separations are being used more and more frequently. Separations can be carried at room temperature, the modular membrane surface can be easily adjusted to the wastewater flows, and various industrial membranes are now available. In order to retain metallic ions, reverse osmosis (or at least nanofiltration) can be used, due to the size of the ions in aqueous solutions. However, the usual permeate fluxes of reverse osmosis membranes are limited and require high transmembrane pressure, which makes the process expensive.During the last decade, there has been a constantly increasing level of interest and research efforts in order to improve the performances of surfactant-based separation processes. In the present study an attempt is made to remove lead(II) ions from synthetic aqueous solutions by micellar-enhanced ultrafiltration (MEUF) using the anionic surfactant sodium dodecylsulfate (SDS). The study has been carried out at a temperature of 318 ÂșK and on a laboratory scale.Ultrafiltration experiments were carried out with a tangential cell system. The inlet flux was held constant (up to 0.5 m.s-1) and the drop in pressure was varied from 1 to 3 bars by restricting the outlet tube. Polysulfone membranes with a molecular weight cut-off (MWCO) of 10,000 Da and an effective filtration area of 30 cm2 were used. The influence of the operating parameters on permeate flux and lead rejection was studied. Rejection coefficients of 99% are reached under optimal conditions of pressure, feed concentration in SDS, tangential velocity of the feed, and percent filtered volume.An ionic exchange model has been used to study the interaction between the lead cation (Pb2+) and sodium dodecylsulfate micelles. The model used to fit the experimental data is an ionic micelle in which the electric double layer is divided into a diffuse outside layer and a Stern layer inside the shear surface. Assuming that divalent cations are strongly attached to the micellar surface and located specifically in the Stern layer of the micelle, it has been found that adsorption in the Stern layer is well described by a Langmuir isotherm. From this isotherm, ion exchange constants for Pb2+ with the Na+ counter-ion have been determined Ke (Na+ /Cd2+) -=1.39, and have been compared with those obtained for other cations (Cd2+, Mg2+) in the same media. In order to determine the performance of the MEUF process in acidic streams, studies were performed at constant cation concentrations and various pH values. The pH variation was obtained by the addition of HClO4 or H3PO4. Rejection remains higher than 95% provided the pH is maintained higher than 1.8

    Electrodialytic Removal of Cadmium from Brackish Water: Effects of Operating Parameters

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    The continuous increase of environmental regulations make interesting to find effective and efficient methods for processing effluents containing metal ions. This research focuses on cadmium removal from brackish water by an electro-membrane process: The electrodialysis. Experiments were carried out on synthetic brackish water solutions and using a laboratory scale electrodialysis system. The influence of several parameters on process efficiency was investigated. The efficiency of this process was assessed by the determination of five parameters: The demineralization rate, the removal rate and the transport flux of cadmium, the current efficiency and the specific power consumption. The applied voltage, the feed flow rate, the pH and cadmium initial concentration of the feed solution have a significant effect on the process efficiency and mainly on the cadmium transfer from dilute to concentrate compartment. In contrast, feed ionic strength seems to affect only the SPC and not the R(Cd)

    Selected components of physical fitness in rhythmic and artistic youth gymnast

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    Abstract Purpose Rhythmic (RG) and artistic gymnastics (AG) are very popular female sports. These two disciplines share some common points but, at the same time, they display some relevant differences in terms of physical and technical characteristics. The aim of this study was as follows: (1) to clarify how gymnastic training background over the years could lead to the development and motor learning of the motor skills and (2) to highlight differences of conditional skills achieved by RG and AG athletes. Methods For these aims, 45 athletes were selected, belonging to three balanced groups: promotional (PG, n = 15), RG (n = 15), and AG (n = 15). Participants were tested for joints mobility, balance, explosive strength, speed, and endurance tests. Results Statistical analysis showed a good test–retest reliability of the measurements (ICC > 0.870) and some significant differences between PG, RG, and AG. RG showed higher values in joint mobility tests (coxo-femoral mobility, 166.7 ± 6.3°; sit and reach, 20.5 ± 1.9 cm; and scapulo-humeral mobility, 45.5 ± 4.4 cm) with respect to AG, while AG showed higher values in endurance (1626.7 ± 7.4 m), balance (4.33 ± 1.35 n/60 s), and explosive strength (164.1 ± 11.6 cm) compared to RG (p < 0.05). Conclusion RG and AG seem to be effective in enhancing different and sport-specific physical fitness and conditioning. RG enables, indeed, to develop more joints mobility whereas AG improves more strength, balance, and endurance. However, given the small sample size employed, these results should be replicated by further studies utilizing larger samples

    Validity and Reliability of a New Specific Parkour Test : Physiological and Performance Responses

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    Main aim of this study was examining validity and reliability of using a new specific Parkour repeated sprint ability test (SPRSA) for assessing repeated sprint ability while facing obstacles and establishing between-day reliability and sensitivity of SPRSA related to its physiological and performance responses. Thirteen high-level traceurs (three females) performed in random order and twice eight tests for assessing a total of 23 variables: SPRSA (a typical maximal-speed shuttle run interspersed with four Parkour competition-common fundamentals) and seven established fitness tests, core stability, hand-grip, vertical-jump, long-jump, pull-up, 300-m shuttle run (as a field test for anaerobic capacity), and Leger test. Except for muscular elasticity index of vertical jump test (intra-class Correlation Coefficient model 3,1 [ICC3,1] = 0.54 [fair]), fitness tests' ICC3,1s resulted excellent (ICC3,1: 0.93-1.00). SPRSA total time and time of its fastest sprint (SPRSA peak time) were significantly correlated with the majority of core stability (r: -0.79 to 0.59; P &lt; 0.01-0.05), jumping (r: -0.78 to 0.67; P &lt; 0.01-0.05), pull-up tests (r: -0.86; P &lt; 0.01), 300-m shuttle run test total time (r: 0.77-0.82; P &lt; 0.01), and Leger test-estimated VO2 max (r: -0.78; P &lt; 0.01). Principal component analysis (PCA) of the 23 variables led to extraction of four significant components (each due to different variables' combinations), which explained 90.2% of 23 variables' total variance. SPRSA (i.e., total and peak time) showed high reliability (ICC3,1: 0.991-0.998 and standard-error-of-measurement %: 0.07-0.32). Finally, SPRSA showed high sensitivity (smallest-worthwhile-change %: 0.29-0.68). Considering its excellent logical and strong ecological validity, SPRSA may serve as a valid specific field test for Parkour sport. In addition, thanks to its high reliability and sensitivity, this test is suitable for monitoring, evaluating, and programming training processes for Parkour practitioners in repeated sprint ability involving crossing obstacles

    Data mining of small RNA-Seq suggests an association between prostate cancer and altered abundance of 5' transfer RNA halves in seminal fluid and prostatic tissues

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    Extracellular RNAs are gaining clinical interest as biofluid-based noninvasive markers for diseases, especially cancer. In particular, derivatives of transfer RNA (tRNA) are emerging as a new class of small-noncoding RNAs with high biomarker potential. We and others previously reported alterations in serum levels of specific tRNA halves in disease states including cancer. Here, we explored seminal fluid for tRNA halves as potential markers of prostate cancer. We found that 5' tRNA halves are abundant in seminal fluid and are elevated in prostate cancer relative to noncancer patients. Importantly, most of these tRNA halves are also detectable in prostatic tissues, and a subset were increased in malignant relative to adjacent normal tissue. These findings emphasize the potential of 5' tRNA halves as noninvasive markers for prostate cancer screening and diagnosis and provide leads for future work to elucidate a putative role of the 5' tRNA halves in carcinogenesis.Joseph M Dhahbi, Hani Atamna and Luke A Selt

    MetMap Enables Genome-Scale Methyltyping for Determining Methylation States in Populations

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    The ability to assay genome-scale methylation patterns using high-throughput sequencing makes it possible to carry out association studies to determine the relationship between epigenetic variation and phenotype. While bisulfite sequencing can determine a methylome at high resolution, cost inhibits its use in comparative and population studies. MethylSeq, based on sequencing of fragment ends produced by a methylation-sensitive restriction enzyme, is a method for methyltyping (survey of methylation states) and is a site-specific and cost-effective alternative to whole-genome bisulfite sequencing. Despite its advantages, the use of MethylSeq has been restricted by biases in MethylSeq data that complicate the determination of methyltypes. Here we introduce a statistical method, MetMap, that produces corrected site-specific methylation states from MethylSeq experiments and annotates unmethylated islands across the genome. MetMap integrates genome sequence information with experimental data, in a statistically sound and cohesive Bayesian Network. It infers the extent of methylation at individual CGs and across regions, and serves as a framework for comparative methylation analysis within and among species. We validated MetMap's inferences with direct bisulfite sequencing, showing that the methylation status of sites and islands is accurately inferred. We used MetMap to analyze MethylSeq data from four human neutrophil samples, identifying novel, highly unmethylated islands that are invisible to sequence-based annotation strategies. The combination of MethylSeq and MetMap is a powerful and cost-effective tool for determining genome-scale methyltypes suitable for comparative and association studies

    External Responsiveness of the SuperOpTM Device to Assess Recovery After Exercise : A Pilot Study

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    Post-exercise recovery is a complex process involving a return of performance and a physiological or perceptual feeling close to pre-exercise status. The hypothesis of this study is that the device investigated here is effective in evaluating the recovery state of professional cyclists in order to plan effective training. Ten professional male cyclists belonging to the same team were enrolled in this study. Participants performed a 7-day exercise program [D1, D4, and D7: low-intensity training; D2 and D5: passive recovery; D3: maximum oxygen consumption (VO2Max) test (for maximum mechanical power assessment only); and D6: constant load test]. During the week of monitoring, each morning before getting up, the device assessed each participant's so-called Organic Readiness {OR [arbitrary unit (a.u.)]}, based on blood pressure (BP), heart rate (HR), features of past exercise session, and following self-perceived condition. Based on its readings and algorithm, the device graphically displayed four different colors/values, indicating general exercise recommendations: green/3 = \u201cyou can train hard,\u201d yellow/2 = \u201cyou can train averagely,\u201d orange/1 = \u201cyou can train lightly,\u201d or red/0 = \u201cyou should recover passively.\u201d During the week of research, morning OR values and Bonferroni post-hoc comparisons showed significant differences between days and, namely, values (1) D2 (after low intensity training) was higher than D4 (after VO2Max test; P = 0.033 and d = 1.296) and (2) D3 and D6 (after passive recovery) were higher than D4 (after VO2Max test; P = 0.006 and d = 2.519) and D5 (after low intensity training; P = 0.033 and d = 1.341). The receiver operating characteristic analysis area under curve (AUC) recorded a result of 0.727 and could differentiate between D3 and D4 with a sensitivity and a specificity of 80%. Preliminarily, the device investigated is a sufficiently effective and sensitive/specific device to assess the recovery state of athletes in order to plan effective training
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