76 research outputs found

    Saharan sand and dust storms and neonatal mortality: Evidence from Burkina Faso

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    West African populations are exposed to the longest and harshest dust storms on the planet, the Saharan sand and dust storms (SDS). Nonetheless, little is known about the effects of the severe storms on early-life health in West Africa. This study investigated the association of the risk of neonatal mortality, an indicator of the population's early-life health, with potential prenatal and neonatal exposure to the Saharan SDS. Data on 30,552 under-five children from Burkina Faso's 1993, 2003, and 2010 demographic and health surveys were matched to the particulate matters (PM) and terrestrial air temperature and precipitation forecasts. Exposure to dust events was measured by the number of days with average PM10 and PM2.5 concentrations above a series of threshold. Intensity-dependent patterns of associations between neonatal mortality and both prenatal and birth month exposure to dust events were identified. There was no association if average daily PM10 and PM2.5 levels were <60 and 30 ƎĀ¼g/m3, respectively. However, strong associations, which increase almost linearly with the intensity of exposure, were identified when daily PM10 and PM2.5 levels ranged from 70 to 150 and from 40 to 70 ƎĀ¼g/m3, respectively. At the higher PM levels, the association for the gestation period decreased, but that for the birth month remained mostly unresponsive to changes in the PM levels. Larger associations were identified when siblings were compared. ƂĀ© 2020 Elsevier B.V

    Economic integration and security in the Middle East and North Africa: what prospects for a liberal peace?

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    Since the late 1980s governments in the Middle East and North Africa (MENA) have created commercial institutions in order to promote regional economic integration. The primary aim of this policy has been regarded as the promotion of economic welfare gains at the national level. A second, albeit less-emphasized goal, has been to promote regional peace through economic interdependence. This study examines the prospects for a liberal peace in the MENA by analyzing two stages of the commercial institutional peace. Firstly, the study considers whether commercial institutions have promoted intra-regional trade in the MENA. Secondly, it examines if economic interaction has had an impact on promoting peace within the region. Twenty states are considered here and the unit of analysis is the dyad-year over a 25-year period from 1990-2014. This study finds that commercial institutions in the MENA have only a limited positive correlation with trade volume and while there is a direct positive correlation between economic integration and peace in the region, this is quite limited. These findings suggest that the conclusions made by previous studies that demonstrate a direct positive correlation between commercial institutions (and economic integration more generally) and peace, may be less applicable to some regions such as MENA

    Functional definition of seizure provides new insight into post-traumatic epileptogenesis

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    Experimental animalsā€™ seizures are often defined arbitrarily based on duration, which may lead to misjudgement of the syndrome and failure to develop a cure. We employed a functional definition of seizures based on the clinical practice of observing epileptiform electrocorticography and simultaneous ictal behaviour, and examined post-traumatic epilepsy induced in rats by rostral parasagittal fluid percussion injury and epilepsy patients evaluated with invasive monitoring. We showed previously that rostral parasagittal fluid percussion injury induces different types of chronic recurrent spontaneous partial seizures that worsen in frequency and duration over the months post injury. However, a remarkable feature of rostral parasagittal fluid percussion injury is the occurrence, in the early months post injury, of brief (<2 s) focal, recurrent and spontaneous epileptiform electrocorticography events (EEEs) that are never observed in sham-injured animals and have electrographic appearance similar to the onset of obvious chronic recurrent spontaneous partial seizures. Simultaneous epidural-electrocorticography and scalp-electroencephalography recordings in the rat demonstrated that these short EEEs are undetectable by scalp electrocorticography. Behavioural analysis performed blinded to the electrocorticography revealed that (i) brief EEEs lasting 0.8ā€“2 s occur simultaneously with behavioural arrest; and (ii) while behavioural arrest is part of the rat's behavioural repertoire, the probability of behavioural arrest is greatly elevated during EEEs. Moreover, spectral analysis showed that EEEs lasting 0.8ā€“2 s occurring during periods of active behaviour with dominant theta activity are immediately followed by loss of such theta activity. We thus conclude that EEEs lasting 0.8ā€“2 s are ictal in the rat. We demonstrate that the assessment of the time course of fluid percussion injury-induced epileptogenesis is dramatically biased by the definition of seizure employed, with common duration-based arbitrary definitions resulting in artificially prolonged latencies for epileptogenesis. Finally, we present four human examples of electrocorticography capturing short (<2 s), stereotyped, neocortically generated EEEs that occurred in the same ictal sites as obvious complex partial seizures, were electrographically similar to rat EEEs and were not noted during scalp electroencephalography. When occurring in the motor cortex, these short EEEs were accompanied by ictal behaviour detectable with simultaneous surface electromyography. These data demonstrate that short (<2 s) focal recurrent spontaneous EEEs are seizures in both rats and humans, that they are undetectable by scalp electroencephalography, and that they are typically associated with subtle and easily missed behavioural correlates. These findings define the earliest identifiable markers of progressive post-traumatic epilepsy in the rat, with implications for mechanistic and prophylactic studies, and should prompt a re-evaluation of the concept of post-traumatic silent period in both animals and humans

    Multicenter evaluation of the clinical utility of laparoscopy-assisted ERCP in patients with Roux-en-Y gastric bypass

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    Background and Aims The obesity epidemic has led to increased use of Roux-en-Y gastric bypass (RYGB). These patients have an increased incidence of pancreaticobiliary diseases yet standard ERCP is not possible due to surgically altered gastroduodenal anatomy. Laparoscopic-ERCP (LA-ERCP) has been proposed as an option but supporting data are derived from single center small case-series. Therefore, we conducted a large multicenter study to evaluate the feasibility, safety, and outcomes of LA-ERCP. Methods This is retrospective cohort study of adult patients with RYGB who underwent LA-ERCP in 34 centers. Data on demographics, indications, procedure success, and adverse events were collected. Procedure success was defined when all of the following were achieved: reaching the papilla, cannulating the desired duct and providing endoscopic therapy as clinically indicated. Results A total of 579 patients (median age 51, 84% women) were included. Indication for LA-ERCP was biliary in 89%, pancreatic in 8%, and both in 3%. Procedure success was achieved in 98%. Median total procedure time was 152 minutes (IQR 109-210) with median ERCP time 40 minutes (IQR 28-56). Median hospital stay was 2 days (IQR 1-3). Adverse events were 18% (laparoscopy-related 10%, ERCP-related 7%, both 1%) with the clear majority (92%) classified as mild/moderate whereas 8% were severe and 1 death occurred. Conclusion Our large multicenter study indicates that LA-ERCP in patients with RYGB is feasible with a high procedure success rate comparable with that of standard ERCP in patients with normal anatomy. ERCP-related adverse events rate is comparable with conventional ERCP, but the overall adverse event rate was higher due to the added laparoscopy-related events

    Experimental and numerical study on the ECARed magnesium AZ31 alloy

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    One of the best methods for applying severe plastic deformation (SPD) to the sheets is equal channel angular rolling (ECAR) process. In this paper, the effect of ECAR process on the AZ31 alloy has been evaluated. Firstly, the process has been accomplished on the magnesium specimens. Then, the effect of ECAR process on mechanical properties of AZ31 alloy such as: microhardness, strength and microstructure have been assessed. For evaluation of the ECAR parameters on the samples, numerical method also has been utilized. Finally, the results indicate that the microhardness after 8th pass ECAR has been increased about 45%. Also, the average grain size has been decreased about 94% after 8th pass ECAR. The yielding stress (Y.S) and ultimate tensile strength (UTS) of AZ31 sheet were decreased by increasing the pass number while, elongation has been improved

    Restructuring and Economic Performance: the Experience of the Tunisian Economy

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    A PDF model of populations of purkinje cells: Non-linear interactions and high variability, Neurocomputing This issue

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    While the Marr/Albus cerebellar model expects Purkinje cells to behave linearly and have noise free outputs, physiological studies suggest otherwise. A cerebellar model based on ensembles of neurons encoding Probability Density Functions (PDFā€™s) described here may resolve these contradictions. Our simulations show that a PDF based model can describe the noisy output of these cells, and more importantly, efficiently compute the complex non-linear functions necessary for the cerebellar computations, such as for the control of arm movement (Bastian et al 1996). We further intend to simulate the computation of more complex functions using similar methods
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