560 research outputs found

    Inhomogeneous Gain Saturation in EDF: Experiment and Modeling

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    Erbium-Doped Fiber Amplifiers can present holes in spectral gain in Wavelength Division Multiplexing operation. The origin of this inhomogeneous saturation behavior is still a subject of controversy. In this paper we present both an experimental methods and a gain's model. Our experimental method allow us to measure the first homogeneous linewidth of the 1.5 μ\mum erbium emission with gain spectral hole burning consistently with the other measurement in the literature and the model explains the differences observed in literature between GSHB and other measurement methods

    WU Polyomavirus in Children, Canada

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    WU polyomavirus was detected in nasopharyngeal aspirates in 2 (2.5%) of 79 children with respiratory infections (both infected with respiratory syncytial virus) and in 5 (6.4%) of 78 asymptomatic children during the same winter season in Canada. The strains were closely related to Australian and American viruses based on analysis of large T antigen (TAg) and VP2 genes. The pathogenic role of WU virus is still uncertain

    Utilisation d'un système de quotas échangeable basé sur l'empreinte écologique pour éviter un déclin des civilisations

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    La compétition sexuelle chez l’homme, qui représente une des bases du comportement, pousse l’humain à consommer et à se reproduire sans cesse. Une solution pour créer une civilisation globale plus durable doit pouvoir intégrer la consommation, la production, la gestion du nombre d’humains ainsi que sa répartition. Ce travail est une proposition pour intégrer un système de quotas échangeables basé sur l’empreinte écologique. Ce système a pour buts de construire un filet de sécurité contre les impacts des cycles économiques, de tendre vers une utilisation de nos ressources plus responsable, d’augmenter la durabilité de la civilisation globale qui se développe et le tout, à l’aide d’une approche socialement acceptable

    Bad housekeeping: why do aphids leave their exuviae inside the colony?

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    <p>Abstract</p> <p>Background</p> <p>Animals can gain protection against predators and parasites by living in groups. The encounter-dilution effect provides protection when the probability of detection of a group does not increase in proportion to group size (i.e. encounter effect), so that predators do not offset the encounter effect by attacking more members of the group (i.e. dilution effect). In this paper, we propose a novel mechanism by which prey insects could gain by producing decoys that act as multiple targets for predators or parasitoids if these decoys are recognised as preys or hosts and negatively affect the patch foraging strategy of these predators and parasitoids. Such a decoy mechanism could be present in aphid colonies in which aphid exuviae are recognised and attacked by Aphidiine wasps.</p> <p>Results</p> <p>We conducted a behavioural study to evaluate the effect of exuviae on parasitoid patch residence time and egg allocation in experimental aphid patches with or without exuviae. We showed that exuviae are recognised and attacked at the same level as aphids when both are present in the patch. While parasitism rate was not significantly lower in patches with exuviae when the parasitoid left the patch, the time wasted by parasitoids to handle exuviae did influence the patch residence time. As a consequence, the attack rate on the live aphids was lower in patches that contain exuviae.</p> <p>Conclusion</p> <p>Aphids had more time available to flee and thus each individual might gain protection against parasitoids by leaving their exuviae near and within the colony. These results demonstrate that the encounter-dilution effect provided by living in a group can be enhanced by extra-materials that act as decoy for natural enemies.</p

    Potential Biomarkers Selection for Bipolar Disorder Identification

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    A biomarker is a measurable indicator of the severity or presence of some disease. A biomarker is anything that can be used as an indicator of a particular disease state or some other physiological state of an organism. The space Decomposition-Gradient-Regression (DGR) method has been developed (Li et al., 2012; Li et al., 2015) to select biomarkers for schizophrenia. This study performs the DGR approach on data for bipolar disorder patients, which contains 56 biomarkers and 8 infectious agent’s antibodies. Serum specimens were collected from 132 United States military service members (118 males and 14 females) with a diagnosis of bipolar disorder from 1992 to 2005 and their matched healthy controls.. Trefoil Factor3 (TFF3), Gliadin, prolactin (PRL), Apolipoprotein A-II (Apo A-II) and Immunoglobulin A (IGA) were found to be significant predictors of Bipolar Disorder (BD) in males. Macrophage-Derived Chemokine (MDC), Alpha-1-Antitrypsin (AAT), Gliadin, Beta-2-Microglobulin (B2M) and Monocyte Chemotactic Protein 2 (MCP-2) might be used to identify bipolar disorder in females. A predictive biomarker panel for BD offers the potential to aid in the diagnosis, initiate treatment earlier and ideally alter the course of disease with reduced morbidity and functional impairment

    Adjustment trajectories during the college transition : types, personal and family antecedents, and academic outcomes

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    This longitudinal study was aimed to describe and understand student adjustment trajectories during the college transition. Participants came from a large random sample of Quebec high school students. They completed a multidimensional measure of adjustment at two times before entering college and at two other times after college admission. Group-based trajectory analysis showed decreased adjustment for 6% (social adjustment) to 66.1% (academic adjustment) of students over this period, versus improved adjustment for 4.5% (social adjustment) to 11.6% (emotional and academic adjustment). All changes were linear, suggesting progressive changes from Secondary 4 to the second year of college. Multivariate and contingency analyses showed that personal anxiety, academic success, and attention problems in high school were significant determinants for adjustment trajectories, and that these trajectories were subsequently related to perseverance and college graduation

    Anatomy and physiology of the mineralized tissues: Role in the pathogenesis of osteoarthrosis

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    AbstractSynovial joints are composed of several different kinds of tissue that interact to protect normal joint function. Three subchondral mineralized tissues can be identified–calcified cartilage, subchondral cortical bone, and subchondral trabecular bone–which are distinguished morphologically, physiologically, and mechanically. Each responds to mechanical and pharmaceutical stimuli in different ways through processes of growth, modeling, and remodeling, and changes in each may have a distinct effect on the health of the joint. It is important to distinguish between the structural properties of these tissues and their material properties as these change differently in osteoarthrosis (OA). It is likely that changes in the mineral content and thickness of the calcified cartilage play a greater role in the pathogenesis of OA than has been realized, whereas changes in trabecular bone are probably not causative. Changes in the subchondral cortical bone may accelerate progression of pre-existing disease, but the combined effects of increased subchondral bone turnover and greater subchondral bone volume are not at all clear. Ultimately, the efficacy of bone anti-resorptive therapies for OA will depend upon whether the increased structural stiffness of the subchondral mineralized tissues predisposes the cartilage to deteriorate, whether the increased bone turnover that occurs in OA is itself a causative factor, or whether the lower tissue elastic modulus offsets the increased structural stiffness of the subchondral plate in an attempt to protect the cartilage from damage

    Wavelength Shifters for Water Cherenkov Detectors

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    The light yield of a water-based Cherenkov detector can be significantly improved by adding a wavelength shifter. Wavelength shifter (WLS) molecules absorb ultraviolet photons and re-emit them at longer wavelengths where typical photomultiplier tubes are more sensitive. In this study, several wavelength shifter compounds are tested for possible deployment in the Sudbury Neutrino Observatory (SNO). Test results on optical properties and chemical compatibility for a few WLS candidates are reported; together with timing and gain measurements. A Monte Carlo simulation of the SNO detector response is used to estimate the total light gain with WLS. Finally, a cosmic ray Cherenkov detector was built to investigate the optical properties of WLS.Comment: 13 pages, 3 figure

    Comparing radiolytic production of H2O2 and development of Zebrafish embryos after ultra high dose rate exposure with electron and transmission proton beams.

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    The physico-chemical and biological response to conventional and UHDR electron and proton beams was investigated, along with conventional photons. The temporal structure and nature of the beam affected both, with electron beam at ≥1400 Gy/s and proton beam at 0.1 and 1260 Gy/s found to be isoefficient at sparing zebrafish embryos
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