Thérapies traditionnelles aux Comores

Cet article présente un tableau général des divers moyens de protection des dangers et de guérison des maux, mis en oeuvre dans la société comorienne. Islamisée de façon continue depuis des siècles, cette société développe aussi une vision populaire du monde et des pratiques magico-religieuses plus ou moins tolérées par l'indulgence de l'islam local. Religion et pratiques populaires ont été elles-mêmes apportées par des groupes de population d'origine africaine, indonésienne, arabe ou malgache, qui ont juxtaposé ou mêlé divers systèmes de représentations. Leurs points communs sont : une vision déterminée d'un monde dominé par des déséquilibres et des concordances à respecter, justifiant l'observance de l'astrologie et le respect d'interdits; un relativisme social qui attribue à l'autre les intentions malveillantes qui ont provoqué le mal, les désordres et les problèmes qui affectent l'être humain, ou sa famille, dans sa vie quotidienne. (Résumé d'auteur

Could Alfa fibers substitute glass fibers in composite materials?

In the present work polyester resin composites with Alfa fibers in the form of pulp were prepared and their properties were compared with those of polyester resin reinforced with glass fibers, the latter composites being widely used for structural applications. The composites were prepared using two manufacturing processes, namely hand lay-up and vacuum molding, to assess the influence of the process on the composites properties. Firstly, the tensile properties for the two composites were evaluated. The composites thermal properties were studied by differential scanning calorimetry and thermogravimetric analysis. Finally, the morphology of a glass fiber composite (GFC) and Alfa pulp composite (APC) was analyzed by scanning electron microscopy, to characterize the composites surface and cross-sections.The authors would like to thank CTC (Centre technique de la Chimie) for their valuable help during mechanical testing. The company Solutions Composites, especially Mr.Adel Hammami is gratefully acknowledged for financial and material support. The authors also wish to thank the members of the Department of Polymer Engineering University of Minho, Guimarães, Portugal for their valuable cooperation. This research work is carried out as part of a mobidocPhD, a program financed by the European Union within Pasri Projet. M.C Paiva acknowledges the Portuguese Foundation for Science and Technology (FCT) and the European program FEDER/COMPETE for the financial support through project PEst-C/CTM/ LA0025/2013 (LA 25-2015-2017)

Production of cellulose nanofibers from Alfa grass and application as reinforcement for polyvinyl alcohol

The work reported demonstrates an simple method of extracting cellulose nanofibers (CNF) from cellulose microfibers (CMF) obtained from the plant Stipatenacissima. Here, a method for the production of CNF from CMF extracted from Alfa grass by exfoliation in polyvinyl alcohol (PVA) solution, is demonstrated. The CMF were produced in powder form and exfoliated in PVA aqueous solution to produce composites with 2, 4, 5 and 10 wt-% of CNF. Scanning Electron Microscopy demonstrated exfoliation of CMF, dispersion of the CNF and wetting by the polymer. The composites were characterised by thermogravimetry, differential scanning calorimetry, X-ray diffraction and tensile testing. The addition of CNF to PVA reduced the crystallinity degree of PVA. The large increase of the Young’s modulus from 38 to 113% (relative to pure PVA) for composites with 2 to 10 wt-% of CNF incorporation is consistent with the extensive exfoliation of CMF into CNF and its excellent interface with PVA.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) for project PEst-C/CTM/ LA0025/2013 (Strategic Project - LA 25 - 2013–2014). Salma Ben Cheikh acknowledges the Ministry of Higher Education and Scientific Research (Tunisia) for a grant to travel to IPC/i3N in Portugal

Customizable vector acceleration in extreme-edge computing. A risc-v software/hardware architecture study on VGG-16 implementation

Computing in the cloud-edge continuum, as opposed to cloud computing, relies on high performance processing on the extreme edge of the Internet of Things (IoT) hierarchy. Hardware acceleration is a mandatory solution to achieve the performance requirements, yet it can be tightly tied to particular computation kernels, even within the same application. Vector-oriented hardware acceleration has gained renewed interest to support artificial intelligence (AI) applications like convolutional networks or classification algorithms. We present a comprehensive investigation of the performance and power efficiency achievable by configurable vector acceleration subsystems, obtaining evidence of both the high potential of the proposed microarchitecture and the advantage of hardware customization in total transparency to the software program

Evaluation de l’activité du cadmium, en présence du zinc, sur les structures des tissus régulateurs du métabolisme chez le rat Wistar

Le sulfate de Cadmium (CdSO4) et le chlorure de Zinc (ZnCl2) ont des effets antagonistes. Le Cd est connu pour son effet nécrotique et le Zn pour son rôle protecteur. L’objectif de cette étude est d’évaluer les effets de l’exposition au Cd sur l’histologie du foie et des reins chez des rats Wistar en présence du Zn. L’étude a porté sur 16 rats, âgés de 4 mois, qui ont été subdivisés en 4 groupes de 4 rats, le 1er groupe recevait par voie orale du Cd (0,15 mg/ kg de poids corporel) pendant un mois, le second groupe a été exposé au Zn à la même dose, un 3e groupe recevait un mélange (Cd-Zn) et le 4e groupe était le témoin recevant de l’eau de robinet dans les même conditions. Les résultats ont montré que  l’exposition des rats au Cd a induit une diminution de leur poids corporel. L’examen histologique, chez les rats exposés au Cd, a révélé des désorganisations cellulaires, des atypies cyto-nucléaires et des nécroses au niveau des tissus hépatiques et rénaux. Par ailleurs, les animaux ayant reçu du Zn ou un mélange Cd-Zn ont préservé l’intégrité de l’organisation cellulaire et nucléaire de leur tissu. L’exposition au Cd était responsable de l’apparition d’importants changements morphologique et histologique chez le rat mais la présence du Zn a atténué partiellement les effets toxiques induits par le Cd.Mots clés : Cadmium, zinc, antagonistes, foie, reins, histologie

Cardiac autonomic control in the obstructive sleep apnea

Introduction: The sympathetic activation is considered to be the main mechanism involved in the development of cardiovascular diseases in obstructive sleep apnea (OSA). The heart rate variability (HRV) analysis represents a non-invasive tool allowing the study of the autonomic nervous system. The impairment of HRV parameters in OSA has been documented. However, only a few studies tackled the dynamics of the autonomic nervous system during sleep in patients having OSA.Aims: To analyze the HRVover sleep stages and across sleep periods in order to clarify the impact of OSA on cardiac autonomic modulation. The second objective is to examine the nocturnal HRV of OSA patients to find out which HRV parameter is the best to reflect the symptoms severity.Methods: The study was retrospective. We have included 30 patients undergoing overnight polysomnography. Subjects were categorized into two groups according to apneahypopnea index (AHI): mild-to-moderate OSAS group (AHI: 5-30) and severe OSAS group (AHI>30). The HRV measures for participants with low apneahypopnea indices were compared to those of patients with high rates of apneahypopnea across the sleep period and sleep stages.Results: HRV measures during sleep stages for the group with low rates of apneahypopnea have indicated a parasympathetic activation during non-rapid eye movement (NREM) sleep. However, no significant difference has been observed in the high AHI group except for the mean of RR intervals (mean RR). The parasympathetic activity tended to increase across the night but without a statistical difference. After control of age and body mass index, the most significant correlation found was for the mean RR (p =0.0001, r = -0.248).Conclusion: OSA affects sympathovagal modulation during sleep, and this impact has been correlated to the severity of the disease. The mean RR seemed to be a better index allowing the sympathovagal balance appreciation during the night in OSA.Keywords: autonomic nervous system; sleep apnea; heart rate; sleep; circadia

Impact of intermittent preventive anti-malarial treatment on the growth and nutritional status of preschool children in rural Senegal (west Africa).

Negative consequences of malaria might account for seasonality in nutritional status in children in the Sahel. We report the impact of a randomized, double-blind, placebo-controlled trial of seasonal intermittent preventive anti-malarial treatment on growth and nutritional status in 1,063 Senegalese preschool children. A combination of artesunate and sulfadoxine-pyrimethamine was given monthly from September to November. In the intervention arm, mean weight gain was significantly greater (122.9 +/- 340 versus 42.9 +/- 344 [SD] g/mo, P < 0.0001) and losses in triceps and subscapular skinfold measurements were less (-0.39 +/- 1.01 versus -0.66 +/- 1.01 mm/mo, and -0.15 +/- 0.64 versus -0.36 +/- 0.62 mm/mo, respectively, P < 0.0001 for both). There was no difference in height increments. The prevalence of wasting increased significantly in the control arm (4.6% before versus 9.5% after, P < 0.0001), but remained constant in intervention children: 5.6% versus 7.0% (P = 0.62). The prevention of malaria would improve child nutritional status in areas with seasonal transmission

In vitro litholytic activity of some medicinal plants on urinary stones

Objective: This study was designed to evaluate the effect of plant extracts used in traditional medicine on the dissolution of three types of kidney stones.Subjects and methods: Kidney calculi of cystine; uric acid and pure carbapatite were incubated in vitro during 6 weeks in the presence of three of plant extracts and of 0.9% NaCl solution used as control. An extract of each plant was prepared by infusion of three grams of powdered plants during 30 min in 100 mL of a boiled NaCl 0.9% aqueous solution. Each extract was then filtered and thereafter set in a flask containing a stones. At the end of each week the stone was removed from the experimental medium and weighted after a 18 h drying at 40oC.Results: After 6 weeks of experiment and with in vitro study, we are observed that the aqueous extract of the seeds of Trigonella foenum-graecum has a better effect on dissolution of cystine and carbapatite stones (p &lt; 0.05), with mass loss of 94 mg and 73 mg respectively at the end of experiment. While with NaCl solution, the mass was small.Conclusion: Our experiment failed to demonstrate a significant effect of the tested plant extracts to dissolve three types stones in vitro. However, we observed that only the extract of the seeds of T. foenum-graecum has a better effect on dissolution of cystine and carbapatite stones probably resulting from formation of complexes between stones and polyphenols or flavonoids present in the extracts

Up-regulation of the P2Y2 receptor by cytokines in neuronal cells

Abstract only availableAlzheimer's Disease (AD) is characterized by inflammation and neurodegeneration in the brain due to the presence of extracellular amyloid beta (A β) plaques and neurofibrillary tangles. Microglial and astrocyte cells associated with these plaques and tangles have been shown to release cytokines in AD patients, which have a proinflammatory effect on the brain. The P2Y2 receptor (P2Y2R) is a receptor protein that is up-regulated in response to damage or stress in a variety of tissues, including blood vessels and salivary gland epithelium. Recently our laboratory has shown that activation of the P2Y2R enhances α -secretase-dependent amyloid precursor protein (APP) processing. APP is proteolytically processed by β - and γ -secretases to release neurodegenerative A β. Alternatively, APP can be cleaved within the A β domain by α -secretase releasing the non-amyloidogenic product, sAPP α, which has been shown to have neuroprotective properties. Primary neurons have low P2Y2R expression, however, it has been demonstrated that cytokines up-regulate P2Y2R in smooth muscle cells. Therefore, this study will explore if cytokines up-regulate P2Y2R expression in primary rat neurons and in SH-SY5Y human neuroblastoma cells. Primary rat neurons and SH-SY5Y human neuroblastoma cells were plated on glass cover slips 24 or 48 hours with individual treatment, or a combination of, human interleukin-1 β (IL1- β), tumor necrosis factor α (TNF α), and interferon γ (IF γ). P2Y2R activity was measured by increases in intracellular calcium concentration ([Ca2+]i ) in response to the P2Y2R agonist UTP. Results support the hypothesis that P2Y2R is up-regulated by cytokines in neuronal cells. Furthermore, real-time PCR results indicate a two-fold increase in P2Y2R mRNA after cytokine treatment. Therefore, activation of the up-regulated P2Y2R in stressed neurons generates a neuroprotective (sAPP α) rather than neurodegenerative (A β) peptide. These results could have a substantial impact on the understanding and treatment of neurological disorders such as AD.Life Sciences Undergraduate Research Opportunity Progra