2,301 research outputs found

    Biodiversité des mouches des fruits (Diptera : Tephritidae) en vergers de manguiers de l'ouest du Burkina Faso : structure et comparaison des communautés de différents sites

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    Introduction. Un inventaire des espèces de Tephritidae dans des vergers de l'ouest du Burkina Faso a été effectué entre décembre 2007 et décembre 2009. Matériel et méthodes. Un piégeage de détection a été mené dans sept vergers de manguiers en utilisant comme appât de la levure de Torula placée dans des pièges Mac Phail. Résultats et discussion. L'identification et le dénombrement des Tephritidae capturées a permis de recenser 18 espèces : neuf du genre Ceratitis, sept du genre Dacus et deux du genre Bactrocera. Ceratitis cosyra et Bactrocera invadens (respectivement 53,02 % et 36,19 % de l'ensemble des captures) se sont révélées être les espèces dominantes. Nous avons mis en évidence une forte similarité des communautés de Tephritidae au niveau des différents sites étudiés (coefficients de similitude entre 42,86 % et 100 %); cette similarité pourrait être expliquée d'une part par l'homogénéité des conditions climatiques, d'autre part par celle de la végétation de la zone d'étude. La proximité des parcelles de cultures maraîchères et la diversité des fruitiers locaux hôtes des Tephritidae autour des vergers de manguiers pourraient être à l'origine de la richesse spécifique élevée que nous avons constatée. Conclusion. Notre étude a révélé une diversité de Tephritidae dans la zone d'investigation qui présente des communautés d'espèces homogènes. Ces résultats seront complétés par l'identification des espèces associées aux dégâts sur manguier et à l'évaluation de leur importance. Ils suggèrent dès à présent la possibilité de développer, contre ces ravageurs, une stratégie de lutte commune à toutes les localités de la zone d'étude de l'ouest du Burkina Faso. (Résumé d'auteur

    Sum rules, plasma frequencies and Hall phenomenology in holographic plasmas

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    We study the AC optical and hall conductivities of Dp/Dq-branes intersections in the probe approximation and use sum-rules to study various associated transport coefficients. We determine that the presence of massive fundamental matter, as compared to massless fundamental matter described holographically by a theory with no dimensional defects, reduces the plasma frequency. We further show that this is not the case when the brane intersections include defects. We discuss in detail how to implement correctly the regularization of retarded Green's functions so that the dispersion relations are satisfied and the low energy behaviour of the system is physically realistic.Comment: 25 pages, 5 figures. v2.minor changes, published versio

    Alterations of immune response of non-small lung cancer with azacytidine

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    Innovative therapies are needed for advanced Non-Small Cell Lung Cancer (NSCLC). We have undertaken a genomics based, hypothesis driving, approach to query an emerging potential that epigenetic therapy may sensitize to immune checkpoint therapy targeting PD-L1/PD-1 interaction. NSCLC cell lines were treated with the DNA hypomethylating agent azacytidine (AZA - Vidaza) and genes and pathways altered were mapped by genome-wide expression and DNA methylation analyses. AZA-induced pathways were analyzed in The Cancer Genome Atlas (TCGA) project by mapping the derived gene signatures in hundreds of lung adeno (LUAD) and squamous cell carcinoma (LUSC) samples. AZA up-regulates genes and pathways related to both innate and adaptive immunity and genes related to immune evasion in a several NSCLC lines. DNA hypermethylation and low expression of IRF7, an interferon transcription factor, tracks with this signature particularly in LUSC. In concert with these events, AZA up-regulates PD-L1 transcripts and protein, a key ligand-mediator of immune tolerance. Analysis of TCGA samples demonstrates that a significant proportion of primary NSCLC have low expression of AZA-induced immune genes, including PD-L1. We hypothesize that epigenetic therapy combined with blockade of immune checkpoints - in particular the PD-1/PD-L1 pathway - may augment response of NSCLC by shifting the balance between immune activation and immune inhibition, particularly in a subset of NSCLC with low expression of these pathways. Our studies define a biomarker strategy for response in a recently initiated trial to examine the potential of epigenetic therapy to sensitize patients with NSCLC to PD-1 immune checkpoint blockade

    The Open Cluster Chemical Analysis and Mapping Survey: Local Galactic Metallicity Gradient with APOGEE using SDSS DR10

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    The Open Cluster Chemical Analysis and Mapping (OCCAM) Survey aims to produce a comprehensive, uniform, infrared-based dataset for hundreds of open clusters, and constrain key Galactic dynamical and chemical parameters from this sample. This first contribution from the OCCAM survey presents analysis of 141 members stars in 28 open clusters with high-resolution metallicities derived from a large uniform sample collected as part of the SDSS-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE). This sample includes the first high-resolution metallicity measurements for 22 open clusters. With this largest ever uniformly observed sample of open cluster stars we investigate the Galactic disk gradients of both [M/H] and [alpha/M]. We find basically no gradient across this range in [alpha/M], but [M/H] does show a gradient for R_{GC} < 10 kpc and a significant flattening beyond R_{GC} = 10 kpc. In particular, whereas fitting a single linear trend yields an [M/H] gradient of -0.09 +/- 0.03$ dex/kpc --- similar to previously measure gradients inside 13 kpc --- by independently fitting inside and outside 10 kpc separately we find a significantly steeper gradient near the Sun (7.9 <= R_{GC} <= 10) than previously found (-0.20 +/- 0.08 dex/kpc) and a nearly flat trend beyond 10 kpc (-0.02 +/- 0.09 dex/kpc).Comment: 6 pages, 4 figures, ApJ letters, in pres

    Extreme infrared variables from UKIDSS-I. A concentration in star-forming regions

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    We present initial results of the first panoramic search for high-amplitude near-infrared variability in theGalactic plane.We analyse the widely separated two-epoch K-band photometry in the fifth and seventh data releases of the UKIDSS Galactic plane survey.We find 45 stars with δK > 1 mag, including two previously known OH/IR stars and a Nova. Even though the midplane is not yet included in the data set, we find the majority (66 per cent) of our sample to be within known star-forming regions (SFRs), with two large concentrations in the Serpens OB2 association (11 stars) and the Cygnus-X complex (12 stars). Sources in SFRs show spectral energy distributions that support classification as young stellar objects (YSOs). This indicates that YSOs dominate the Galactic population of high-amplitude infrared variable stars at low luminosities and therefore likely dominate the total high-amplitude population. Spectroscopic follow up of the DR5 sample shows at least four stars with clear characteristics of eruptive premain- sequence variables, two of which are deeply embedded. Our results support the recent concept of eruptive variability comprising a continuum of outburst events with different timescales and luminosities, but triggered by a similar physical mechanism involving unsteady accretion. Also, we find what appears to be one of the most variable classical Be stars. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society

    Antipsychotics and Torsadogenic Risk: Signals Emerging from the US FDA Adverse Event Reporting System Database

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    Background: Drug-induced torsades de pointes (TdP) and related clinical entities represent a current regulatory and clinical burden. Objective: As part of the FP7 ARITMO (Arrhythmogenic Potential of Drugs) project, we explored the publicly available US FDA Adverse Event Reporting System (FAERS) database to detect signals of torsadogenicity for antipsychotics (APs). Methods: Four groups of events in decreasing order of drug-attributable risk were identified: (1) TdP, (2) QT-interval abnormalities, (3) ventricular fibrillation/tachycardia, and (4) sudden cardiac death. The reporting odds ratio (ROR) with 95 % confidence interval (CI) was calculated through a cumulative analysis from group 1 to 4. For groups 1+2, ROR was adjusted for age, gender, and concomitant drugs (e.g., antiarrhythmics) and stratified for AZCERT drugs, lists I and II (http://www.azcert.org, as of June 2011). A potential signal of torsadogenicity was defined if a drug met all the following criteria: (a) four or more cases in group 1+2; (b) significant ROR in group 1+2 that persists through the cumulative approach; (c) significant adjusted ROR for group 1+2 in the stratum without AZCERT drugs; (d) not included in AZCERT lists (as of June 2011). Results: Over the 7-year period, 37 APs were reported in 4,794 cases of arrhythmia: 140 (group 1), 883 (group 2), 1,651 (group 3), and 2,120 (group 4). Based on our criteria, the following potential signals of torsadogenicity were found: amisulpride (25 cases; adjusted ROR in the stratum without AZCERT drugs = 43.94, 95 % CI 22.82-84.60), cyamemazine (11; 15.48, 6.87-34.91), and olanzapine (189; 7.74, 6.45-9.30). Conclusions: This pharmacovigilance analysis on the FAERS found 3 potential signals of torsadogenicity for drugs previously unknown for this risk

    Non-conformance with regulatory codes in the non-profit sector: accountability and the discursive coupling of means and ends

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    The concept of means-ends decoupling has recently been suggested as one consequence of the problems organizations face in trying to comply with institutional rules in contexts of institutional complexity. Such decoupling is characterised by the adoption, implementation and scrutiny of particular codes of practice which tend not to deliver the outcomes they were developed to produce. Recent scholarship focusing on this issue has suggested that such decoupling is a consequence of the “trade-off” organizations need to make between compliance and goal achievement most especially when the latter is difficult to evaluate. While recent scholarship has suggested that this tension might be mitigated by the activities of developers of compliance rules, in this paper, we explore how actors internal to an organization, in this case, two charitable organizations mitigate this tension via non-conformance with particular codes. We focus on how the process of accounting for non-conformance results in the discursive coupling of means and ends as actors creatively develop vocabularies of motive which respond to anticipated social criticism
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