157 research outputs found

    Assessment of Electrical Safety Beliefs and Practices: A Case Study

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    In this paper, the electrical safety beliefs and practices in Hail region, Saudi Arabia, have been assessed. Based on legislative recommendations and rules applied in Saudi Arabia, on official statistics regarding the electricity-caused accidents and on the analysis of more than 200 photos captured in Hail (related to electrical safety), a questionnaire composed of 36 questions (10 for the respondents information, 16 for the home safety culture and 10 for the electrical devices purchasing culture) has been devised and distributed to residents. 228 responses have been collected and analyzed. Using a scale similar to the one adopted for a university student GPA calculation, the electrical safety level (ESL) in Hail region has been found to be 0.76 (in a scale of 4 points) which is a very low score and indicates a poor electrical safety culture. Several recommendations involving different competent authorities have been proposed. Future work will concern the assessment of safety in industrial companies in Hail region

    Geometric synthesis of a hybrid limit cycle for the stabilizing control of a class of nonlinear switched dynamical systems

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    International audienceThis paper proposes a new constructive method for synthesizing a hybrid limit cycle for the stabilizing control of a class of switched dynamical systems in IR 2 , switching between two discrete modes and without state discontinuity. For each mode, the system is continuous, linear or nonlinear. This method is based on a geometric approach. The first part of this paper demonstrates a necessary and sufficient condition of the existence and stability of a hybrid limit cycle consisting of a sequence of two operating modes in IR 2 which respects the technological constraints (minimum duration between two successive switchings, boundedness of the real valued state variables). It outlines the established method for reaching this hybrid limit cycle from an initial state, and then stablizing it, taking into account the constraints on the continuous variables. This is then illustrated on a Buck electrical energy converter and a nonlinear switched system in IR 2. The second part of the paper proposes and demonstrates an extension to IR n for a class of systems, which is then illustrated on a nonlinear switched system in IR 3

    Recurrence of Uterine Rupture in a Pseudo-Unicornuate Uterus at 17 Weeks of Amenorrhea: Case Report and Literature Review

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    Pregnancy in a rudimentary horn is a very rare condition. It is responsible for several complications. Prognosis is reserved because the natural evolution generally leads to a cataclysmic uterine rupture at the beginning of the second trimester. Classically, the treatment after foetal extraction consists of ablation of the rudimentary horn and associated fallopian tube. We report the obstetric outcome of a patient with history of rudimentary uterine horn rupture, the treatment of which was ablation of the rudimentary horn

    La mucormycose nasosinusienne: Diagnostic et modalites therapeutiques

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    La mucormycose est une infection fongique rare qui touche essentiellement les sujets immunodéprimés et notamment diabétiques. La localisation de cette maladie est surtout nasosinusienne. Son pronostic reste mauvais malgré le développement des moyens de prise en charge. Nous rapportons deux cas de mucormycose nasosinusienne à travers lesquels nous discutons les aspects cliniques et radiologiques, ainsi que les moyens thérapeutiques de cette maladie. Il s’agit d’un homme et d’une femme âgés respectivement de 56 et 52 ans. Le premier était diabétique et la deuxième insuffisante rénale. L’évolution était lente dans le premier cas et très rapide dans le deuxième. Le diagnostic était dans les deux cas histologique. L’évolution était, dans le premier cas, favorable après traitement associant débridement chirurgical et amphotéricine B, et dans le second rapidement fatale. Conclusion : La mucormycose nasosinusienne est une affection grave dont le pronostic peut être mauvais malgré le traitement.Mots clés : Infection fongique, mucormycose rhinocérébrale, zygomycètes

    Ghost interactions in MEG/EEG source space : A note of caution on inter-areal coupling measures

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    When combined with source modeling, magneto- (MEG) and electroencephalography (EEG) can be used to study long-range interactions among cortical processes non-invasively. Estimation of such inter-areal connectivity is nevertheless hindered by instantaneous field spread and volume conduction, which artificially introduce linear correlations and impair source separability in cortical current estimates. To overcome the inflating effects of linear source mixing inherent to standard interaction measures, alternative phase- and amplitude-correlation based connectivity measures, such as imaginary coherence and orthogonalized amplitude correlation have been proposed. Being by definition insensitive to zero-lag correlations, these techniques have become increasingly popular in the identification of correlations that cannot be attributed to field spread or volume conduction. We show here, however, that while these measures are immune to the direct effects of linear mixing, they may still reveal large numbers of spurious false positive connections through field spread in the vicinity of true interactions. This fundamental problem affects both region-of-interest-based analyses and all-to-all connectome mappings. Most importantly, beyond defining and illustrating the problem of spurious, or "ghost" interactions, we provide a rigorous quantification of this effect through extensive simulations. Additionally, we further show that signal mixing also significantly limits the separability of neuronal phase and amplitude correlations. We conclude that spurious correlations must be carefully considered in connectivity analyses in MEG/EEG source space even when using measures that are immune to zero-lag correlations.Peer reviewe

    Management and Outcome of Cardiac and Endovascular Cystic Echinococcosis

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    Cardiac and vascular involvement are infrequent in classical cystic echinococcosis (CE), but when they occur they tend to present earlier and are associated with complications that may be life threatening. Cardiovascular CE usually requires complex surgery, so in low-income countries the outcome is frequently fatal. This case series describes the characteristics of cardiovascular CE in patients diagnosed and treated at a Tropical Medicine & Clinical Parasitology Center in Spain. A retrospective case series of 11 patients with cardiac and/or endovascular CE, followed-up over a period of 15 years (1995–2009) is reported. The main clinical manifestations included thoracic pain or dyspnea, although 2 patients were asymptomatic. The clinical picture and complications vary according to cyst location. Isolated cardiac CE may be cured after surgery, while endovascular extracardiac involvement is associated with severe chronic complications. CE should be included in the differential diagnosis of cardiovascular disease in patients from endemic areas. CE is a neglected disease and further studies are necessary in order to make more definite management recommendations for this rare and severe form of the disease. The authors propose a general approach based on cyst location: exclusively cardiac, endovascular or both

    Profiling bacterial communities associated with sediment-based aquaculture bioremediation systems under contrasting redox regimes

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    Deposit-feeding invertebrates are proposed bioremediators in microbial-driven sediment-based aquaculture effluent treatment systems. We elucidate the role of the sediment reduction-oxidation (redox) regime in structuring benthic bacterial communities, having direct implications for bioremediation potential and deposit-feeder nutrition. The sea cucumber Holothuria scabra was cultured on sediments under contrasting redox regimes; fully oxygenated (oxic) and redox stratified (oxic-anoxic). Taxonomically, metabolically and functionally distinct bacterial communities developed between the redox treatments with the oxic treatment supporting the greater diversity; redox regime and dissolved oxygen levels were the main environmental drivers. Oxic sediments were colonised by nitrifying bacteria with the potential to remediate nitrogenous wastes. Percolation of oxygenated water prevented the proliferation of anaerobic sulphate-reducing bacteria, which were prevalent in the oxic-anoxic sediments. At the predictive functional level, bacteria within the oxic treatment were enriched with genes associated with xenobiotics metabolism. Oxic sediments showed the greater bioremediation potential; however, the oxic-anoxic sediments supported a greater sea cucumber biomass. Overall, the results indicate that bacterial communities present in fully oxic sediments may enhance the metabolic capacity and bioremediation potential of deposit-feeder microbial systems. This study highlights the benefits of incorporating deposit-feeding invertebrates into effluent treatment systems, particularly when the sediment is oxygenated
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