462 research outputs found

    Extracting the Essence of Flexibility in System Design

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    The modest purpose of this paper is to review the concept of flexibility as discussed in various fields of investigations, and to extract its characteristic features. In order to discuss any subject matter clearly, it is necessary to begin with a clear set of definitions. Indeed much can be gained through careful and consistent definitions of terms alone. Flexibility however is a word rich with ambiguity. While it is being increasingly used in various fields, few attempts have been made to formally define, quantify, and propose ways for achieving flexibility. This paper proposes to fill in part this gap by synthesizing a clear and consistent definition of flexibility. It will do so by reviewing the usage of the term in various fields of inquiries, and show that it is indeed possible to clearly and unambiguously characterize flexibility, and to disentangle it from closely related concepts

    L Band Brightness Temperature Observations over a Corn Canopy during the Entire Growth Cycle

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    During a field campaign covering the 2002 corn growing season, a dual polarized tower mounted L-band (1.4 GHz) radiometer (LRAD) provided brightness temperature (TB) measurements at preset intervals, incidence and azimuth angles. These radiometer measurements were supported by an extensive characterization of land surface variables including soil moisture, soil temperature, vegetation biomass, and surface roughness. In the period May 22 to August 30, ten days of radiometer and ground measurements are available for a corn canopy with a vegetation water content (W) range of 0.0 to 4.3 kg m−2. Using this data set, the effects of corn vegetation on surface emissions are investigated by means of a semi-empirical radiative transfer model. Additionally, the impact of roughness on the surface emission is quantified using TB measurements over bare soil conditions. Subsequently, the estimated roughness parameters, ground measurements and horizontally (H)-polarized TB are employed to invert the H-polarized transmissivity (γh) for the monitored corn growing season

    Body dysmorphic disorder in patients undergoing septorhinoplasty surgery: should we be performing routine screening?

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    Objective: Body dysmorphic disorder (BDD) is defined as having a preoccupation with a perceived flaw in one's appearance, which appears slight to others and significantly interferes with a person's functioning. When undetected in septorhinoplasty patients, it will often lead to poor outcomes. // Design: We performed a prospective cohort study to determine the prevalence of BDD in our patients and whether surgical correction could be considered. // Setting and participants: We recruited 34 patients being considered for septorhinoplasty in a tertiary referral rhinology clinic and a control group of 50 from the otology clinic giving a total of 84. // Main outcome measures: Participants completed the Body Dysmorphic Disorder Questionnaire (BDDQ), the sino‐nasal outcome test‐23 (SNOT‐23) and underwent nasal inspiratory peak flow (NIPF). Those found to be at high risk for BDD were referred to a clinical psychologist. // Results: Of the septorhinoplasty patients, 11 (32%) were high risk for BDD. Following psychological assessment, 7 (63%) patients were felt to be unsuitable for surgery and were offered psychological therapy. SNOT‐23 scores were significantly higher in the BDD group indicating a negative impact on quality of life. NIPF readings were not significantly different in the BDD group compared to the control group. // Conclusions: The BDDQ is a valid tool for identifying patients at risk of BDD. A close working relationship with clinical psychology has been advantageous to help the selection process of candidates for surgery when there is a high risk of BDD

    The nuclear receptor LXR modulates interleukin-18 levels through multiple mechanisms

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    IL-18 is a member of the IL-1 family involved in innate immunity and inflammation. Deregulated levels of IL-18 are involved in the pathogenesis of multiple disorders including inflammatory and metabolic diseases, yet relatively little is known regarding its regulation. Liver X receptors or LXRs are key modulators of macrophage cholesterol homeostasis and immune responses. Here we show that LXR ligands negatively regulate LPS-induced mRNA and protein expression of IL-18 in bone marrow-derived macrophages. Consistent with this being an LXR-mediated process, inhibition is abolished in the presence of a specific LXR antagonist and in LXR-deficient macrophages. Additionally, IL-18 processing of its precursor inactive form to its bioactive state is inhibited by LXR through negative regulation of both pro-caspase 1 expression and activation. Finally, LXR ligands further modulate IL-18 levels by inducing the expression of IL-18BP, a potent endogenous inhibitor of IL-18. This regulation occurs via the transcription factor IRF8, thus identifying IL-18BP as a novel LXR and IRF8 target gene. In conclusion, LXR activation inhibits IL-18 production through regulation of its transcription and maturation into an active pro-inflammatory cytokine. This novel regulation of IL-18 by LXR could be applied to modulate the severity of IL-18 driven metabolic and inflammatory disorders

    Management and outcomes following emergency surgery for traumatic brain injury - A multi-centre, international, prospective cohort study (the Global Neurotrauma Outcomes Study).

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    Introduction:Traumatic brain injury (TBI) accounts for a significant amount of death and disability worldwide and the majority of this burden affects individuals in low-and-middle income countries. Despite this, considerable geographical differences have been reported in the care of TBI patients. On this background, we aim to provide a comprehensive international picture of the epidemiological characteristics, management and outcomes of patients undergoing emergency surgery for traumatic brain injury (TBI) worldwide. Methods and analysis:The Global Neurotrauma Outcomes Study (GNOS) is a multi-centre, international, prospective observational cohort study. Any unit performing emergency surgery for TBI worldwide will be eligible to participate. All TBI patients who receive emergency surgery in any given consecutive 30-day period beginning between 1st of November 2018 and 31st of December 2019 in a given participating unit will be included. Data will be collected via a secure online platform in anonymised form. The primary outcome measures for the study will be 14-day mortality (or survival to hospital discharge, whichever comes first). Final day of data collection for the primary outcome measure is February 13th. Secondary outcome measures include return to theatre and surgical site infection. Ethics and dissemination:This project will not affect clinical practice and has been classified as clinical audit following research ethics review. Access to source data will be made available to collaborators through national or international anonymised datasets on request and after review of the scientific validity of the proposed analysis by the central study team
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