51 research outputs found

    Le contrôle d'un jet d'air rectangulaire via l'introduction de cylindres animés d'un mouvement de rotation

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    L'idée à l'origine de l'étude est de modifier la structure d'un écoulement pour transformer cet écoulement convectivement instable en un écoulement globalement instable. Les jets globalement instables montrent un taux d'expansion plus élevé que les jets homogènes convectivement instables. Une simulation numérique a montré que le forçage, d'un jet convectivement instable, au moyen de sources de vorticité contrôlées, conduisait à une augmentation du mélange. Notre étude vise à réaliser un montage expérimental équivalent afin de confirmer les premiers résultats observés

    APOE ɛ4 is associated with postictal confusion in patients with medically refractory temporal lobe epilepsy

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    This study examined the relationship between the APOE ɛ4 allele and postictal confusion in patients with medically intractable temporal lobe epilepsy (TLE). Patients with at least one ɛ4 allele (n = 22) were three times more likely to exhibit postictal confusion (68%) than the 63 patients without ɛ4 (43%). These preliminary results demonstrate that APOE ɛ4 is associated with an increased risk of postictal confusion in patients with medically intractable TLE, suggesting possible dysfunction in neuronal recovery mechanisms

    A new era of wide-field submillimetre imaging: on-sky performance of SCUBA-2

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    SCUBA-2 is the largest submillimetre wide-field bolometric camera ever built. This 43 square arc-minute field-of-view instrument operates at two wavelengths (850 and 450 microns) and has been installed on the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. SCUBA-2 has been successfully commissioned and operational for general science since October 2011. This paper presents an overview of the on-sky performance of the instrument during and since commissioning in mid-2011. The on-sky noise characteristics and NEPs of the 450 and 850 micron arrays, with average yields of approximately 3400 bolometers at each wavelength, will be shown. The observing modes of the instrument and the on-sky calibration techniques are described. The culmination of these efforts has resulted in a scientifically powerful mapping camera with sensitivities that allow a square degree of sky to be mapped to 10 mJy/beam rms at 850 micron in 2 hours and 60 mJy/beam rms at 450 micron in 5 hours in the best weather.Comment: 18 pages, 15 figures.SPIE Conference series 8452, Millimetre, Submillimetre and Far-infrared Detectors and Instrumentation for Astronomy VI 201

    The InfraRed Imaging Spectrograph (IRIS) for TMT: photometric characterization of anisoplanatic PSFs and testing of PSF-Reconstruction via AIROPA

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    The InfraRed Imaging Spectrograph (IRIS) is a first-light instrument for the Thirty Meter Telescope (TMT) that will be used to sample the corrected adaptive optics field by the Narrow-Field Infrared Adaptive Optics System (NFIRAOS) with a near-infrared (0.8 - 2.4 µm) imaging camera and integral field spectrograph. To better understand IRIS science specifications we use the IRIS data simulator to characterize relative photometric precision and accuracy across the IRIS imaging camera 34”x34” field of view. Because the Point Spread Function (PSF) varies due to the effects of anisoplanatism, we use the Anisoplanatic and Instrumental Reconstruction of Off-axis PSFs for AO (AIROPA) software package to conduct photometric measurements on simulated frames using PSF-fitting as the PSF varies in single-source, binary, and crowded field use cases. We report photometric performance of the imaging camera as a function of the instrumental noise properties including dark current and read noise. Using the same methods, we conduct comparisons of photometric performance with reconstructed PSFs, in order to test the veracity of the current PSF-Reconstruction algorithms for IRIS/TMT

    The InfraRed Imaging Spectrograph (IRIS) for TMT: photometric characterization of anisoplanatic PSFs and testing of PSF-Reconstruction via AIROPA

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    The InfraRed Imaging Spectrograph (IRIS) is a first-light instrument for the Thirty Meter Telescope (TMT) that will be used to sample the corrected adaptive optics field by the Narrow-Field Infrared Adaptive Optics System (NFIRAOS) with a near-infrared (0.8 - 2.4 µm) imaging camera and integral field spectrograph. To better understand IRIS science specifications we use the IRIS data simulator to characterize relative photometric precision and accuracy across the IRIS imaging camera 34”x34” field of view. Because the Point Spread Function (PSF) varies due to the effects of anisoplanatism, we use the Anisoplanatic and Instrumental Reconstruction of Off-axis PSFs for AO (AIROPA) software package to conduct photometric measurements on simulated frames using PSF-fitting as the PSF varies in single-source, binary, and crowded field use cases. We report photometric performance of the imaging camera as a function of the instrumental noise properties including dark current and read noise. Using the same methods, we conduct comparisons of photometric performance with reconstructed PSFs, in order to test the veracity of the current PSF-Reconstruction algorithms for IRIS/TMT

    The EGS Grading Scale For Skin And Soft Tissue Infections Is Predictive Of Poor Outcomes : A Multicenter Validation Study

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    Introduction: Over the last five years, the American Association for the Surgery of Trauma (AAST) has developed grading scales for Emergency General Surgery (EGS) diseases. In a prior validation study using diverticulitis, the grading scales were predictive of complications and length of stay. As EGS encompasses diverse diseases, the purpose of this study was to validate the grading scale concept against a different disease process with a higher associated mortality. We hypothesized that the grading scale would be predictive of complications, length of stay and mortality in skin and soft tissue infections (STI). Methods: This multi-institutional trial encompassed 12 centers. Data collected included demographic variables, disease characteristics and outcomes such as mortality, overall complications, hospital and ICU length of stay. The EGS scale for STI was used to grade each infection and two surgeons graded each case to evaluate inter-rater reliability. Results: 1170 patients were included in this study. Inter-rater reliability was moderate (kappa coefficient 0.472-0.642, with 64-76% agreement). Higher grades (IV and V) corresponded to significantly higher LRINEC scores when compared with lower EGS grades. Patients with grade IV and V STI had significantly increased odds of all complications, as well as ICU and overall length of stay. These associations remained significant in logistic regression controlling for age, gender, comorbidities, mental status and hospital-level volume. Grade V disease was significantly associated with mortality as well. Conclusion: This validation effort demonstrates that Grade IV and V STI are significantly predictive of complications, hospital length of stay and mortality. Though predictive ability does not improve linearly with STI grade, this is consistent with the clinical disease process, in which lower grades represent cellulitis and abscess and higher grades are invasive infections. This second validation study confirms the EGS grading scale as predictive, and easily used, in disparate disease processes

    Sustainable Blue-Green Infrastructure: A social practice approach to understanding community preferences and stewardship

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    © 2019 Blue-Green Infrastructure (BGI) is an approach to urban flood resilience, recognised globally and in international literature, that capitalises on the benefits of working with urban green-spaces and naturalised water-flows. Literature reveals BGI's sustainable functioning and benefits-provision depend on the behaviour of those who use it, therefore local stewardship is often proposed to support maintenance. However, there is a gap in understanding the requirements and behaviours of users, as well as their potential for developing stewardship behaviours, that is not addressed through traditional analysis approaches based around demographics. Therefore, this research used correlation analysis of survey data from two locations in the UK to explore the potential contribution of Social Practice Theory (SPT) to improve such understanding. Results show statistically significant correlation (better than 1%) between performance of practices associated with urban BGI and attitudes towards BGI stewardship, whereas demographic variables showed little correlation. Reflection on the practices demonstrates that this connection is traceable through the meanings people attach to their practices, the benefits of BGI spaces as material to those practices and their competencies in relation to existing and proposed stewardship practices. Practices, it is proposed, have embedded behaviours and attitudes that transcend locational and demographic factors. These findings imply in a wider context that, for any proposed or existing BGI, understanding associated practices would improve targeting of stewardship-engagement towards users with compatible meanings and competencies. Furthermore, sustainable design of BGI would benefit from consultation with all identified user-groups in order to understand existing and potential practices

    Suffering to Change

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    Assessment of depression in epilepsy: the utility of common and disease-specific self-report depression measures

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    OBJECTIVES: Depression is common in epilepsy, with rates ranging from 20 to 55% in most samples and reports as high as 70% in patients with intractable epilepsy. However, some contend that depression may be over- and/or under-reported and treated in this population. This may be due to the use of common self-report depression measures that fail to take into account the overlap of disease and depressive symptoms and also the host of side effects associated with antiepileptic medication, which may also be construed as depression. METHODS: The present study examined the utility of common self-report depression measures and those designed specifically for the medically ill, including a proposed new measure, to determine which may be more appropriate for use among people with epilepsy. RESULTS: We found that common self-report depression measures are useful for screening depression in epilepsy, particularly with a raised cutoff for one, with sensitivities ranging from .91 to .96. A measure designed for the medically ill obtained the greatest specificity of .91, suggesting its use as a diagnostic tool with a slightly raised cutoff. The positive likelihood ratio of this latter measure was 8.76 with an overall classification accuracy of 88%. CONCLUSIONS: Assessment of depression in epilepsy can be improved when utilizing self-report measures that better differentiate disease symptoms from neurovegetative symptoms of depression (e.g. fatigue, sleep disturbance). This was demonstrated in the present study. Clinical implications are discussed
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