Comparative study of a time diversity scheme applied to G3 systems for narrowband power-line communications

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in ful lment of the requirements for the degree of Masters of Science in Engineering (Electrical). Johannesburg, 2016Power-line communications can be used for the transfer of data across electrical net- works in applications such as automatic meter reading in smart grid technology. As the power-line channel is harsh and plagued with non-Gaussian noise, robust forward error correction schemes are required. This research is a comparative study where a Luby transform code is concatenated with power-line communication systems provided by an up-to-date standard published by electricit e R eseau Distribution France named G3 PLC. Both decoding using Gaussian elimination and belief propagation are imple- mented to investigate and characterise their behaviour through computer simulations in MATLAB. Results show that a bit error rate performance improvement is achiev- able under non worst-case channel conditions using a Gaussian elimination decoder. An adaptive system is thus recommended which decodes using Gaussian elimination and which has the appropriate data rate. The added complexity can be well tolerated especially on the receiver side in automatic meter reading systems due to the network structure being built around a centralised agent which possesses more resources.MT201

Les enjeux quotidiens avec lesquels doivent vivre les personnes schizophrènes désinstitutionnalisées de la région des Bois-Francs : le point de vue d'intervenants spécialisés

Affiche présentée dans le cadre du colloque de l'ARC "La gestion de la propriété intellectuelle : courants de pensée et facteurs de succès", lors du 81e Congrès de l'Acfas à l'Université Laval, le 8 mai 2013.Le deuxième prix ex aequo a été décerné à Geneviève Rivard au concours des Prix étudiants 2012-2013 de l'ARC.Dans le monde, une personne sur cent souffre de schizophrénie. Or ce trouble reste méconnu, malgré les souffrances qui y sont associées. Peu de chercheurs ont étudié les enjeux sociaux entourant la vie des schizophrènes. La présente recherche décrit ces enjeux selon le point de vue d'intervenants en santé mentale. Les résultats obtenus nous informent sur la vie quotidienne des schizophrènes et sur leurs relations avec leur entourage. Suit une discussion sur les relations interpersonnelles difficiles des personnes atteintes ainsi que les préjugés entretenus par la population

A Multi-level Investigation of Information Technology Outsourcing

This study proposes and tests a model of the information technology (IT) outsourcing decision that includes antecedents of both transaction costs and production costs. Production costs show the most robust influence on governance. Skills required to execute the activities, interdependence between the activities, and firm-level characteristics – uncertainty and knowledge intensity – are the main explanatory variables of the decision. Transaction-level uncertainty is the only transaction cost variable found to influence the decision

La reconfiguration des soins de santé et la réorganisation du travail infirmier

Les fermetures d'hôpitaux et la réduction drastique de l'emploi ne sont que les manifestations les plus visibles de l'actuelle reconfiguration du système de santé au Québec qui affecte profondément la production des soins et l'organisation du travail infirmier dans l'hôpital de courte durée. Largement inspirés de l'expérience américaine, les changements en cours seront analysés en prenant pour exemple la régie régionale de Québec et le CHUQ. Il sera notamment démontré, sur la base d'une analyse de l'évolution du travail infirmier dans six unités de soins, que deux évolutions sont possibles, selon que domine la déqualification ou la reprofessionnalisation du travail

Évaluation non-destructive de la fissuration des ouvrages massifs en béton par la méthode de résistivité électrique

Le vieillissement de structures massives en béton (barrages, écluses) est un problème majeur en raison de la diminution des propriétés du béton au fil du temps. La réhabilitation de ces structures étant souvent moins coûteuse que la reconstruction, on fait appel à des méthodes d’auscultation pour détecter, localiser et caractériser l’endommagement. Le choix de la méthode s'est porté sur la résistivité électrique en raison de sa pertinence pour la détection des fissures. Pour caractériser les discontinuités internes à la structure, nous proposons de réaliser des mesures de résistivité à l’intérieur de forages, déjà existant dans les structures, à l’aide d’une sonde normale électrique. Elle possède quatre espacements d’électrodes soit quatre niveaux d’informations qui diffèrent selon la profondeur d'investigation prospectée. L’idée est de coupler ces informations afin d’estimer, à partir d’un processus d’inversion basé sur une approche par métamodèle, la position en profondeur, l’ouverture, et l’extension horizontale des discontinuités. Pour cela, l’étude s’appuie sur un travail de modélisation en 2-D axisymétrie pour quantifier la réponse de l’outil face à une discontinuité donnée. Une mise en équation pour chaque espacement de la sonde est effectuée et un couplage des informations est établi. Pour une fissure horizontale et d’extension infinie, l’ouverture est estimée à plus ou moins 2 mm pour des fissures centimétriques et à 5 dixièmes de millimètre pour des fissures millimétriques. Des campagnes d’investigation sur une écluse sont entreprises pour appuyer les résultats en modélisation et pour valider les capacités de la méthode de résistivité électrique et le processus d’inversion proposé. Cette analyse préliminaire sur l’ouverture de la fissuration est concluante et encourage la poursuite de la quantification en termes d’extension et d’inclinaison. Ces études montrent l’intérêt du développement de technologies géophysiques existantes dans le cadre de la durabilité des structures massives en béton

One-Year Safety Analysis of the COMPARE-AMI Trial: Comparison of Intracoronary Injection of CD133+ Bone Marrow Stem Cells to Placebo in Patients after Acute Myocardial Infarction and Left Ventricular Dysfunction

Bone marrow stem cell therapy has emerged as a promising approach to improve healing of the infarcted myocardium. Despite initial excitement, recent clinical trials using non-homogenous stem cells preparations showed variable and mixed results. Selected CD133+ hematopoietic stem cells are candidate cells with high potential. Herein, we report the one-year safety analysis on the initial 20 patients enrolled in the COMPARE-AMI trial, the first double-blind randomized controlled trial comparing the safety, efficacy, and functional effect of intracoronary injection of selected CD133+ cells to placebo following acute myocardial infarction with persistent left ventricular dysfunction. At one year, there is no protocol-related complication to report such as death, myocardial infarction, stroke, or sustained ventricular arrhythmia. In addition, the left ventricular ejection fraction significantly improved at four months as compared to baseline and remained significantly higher at one year. These data indicate that in the setting of the COMPARE-AMI trial, the intracoronary injection of selected CD133+ stem cells is secure and feasible in patients with left ventricle dysfunction following acute myocardial infarction

The 20S proteasome core, active within apoptotic exosome-like vesicles, induces autoantibody production and accelerates rejection

Autoantibodies to components of apoptotic cells, such as anti-perlecan antibodies, contribute to rejection in organ transplant recipients. However, mechanisms of immunization to apoptotic components remain largely uncharacterized. We used large-scale proteomics, with validation by electron microscopy and biochemical methods, to compare the protein profiles of apoptotic bodies and apoptotic exosome-like vesicles, smaller extracellular vesicles released by endothelial cells downstream of caspase-3 activation. We identified apoptotic exosome-like vesicles as a central trigger for production of anti-perlecan antibodies and acceleration of rejection. Unlike apoptotic bodies, apoptotic exosome-like vesicles triggered the production of anti-perlecan antibodies in naïve mice and enhanced anti-perlecan antibody production and allograft inflammation in mice transplanted with an MHC (major histocompatibility complex)–incompatible aortic graft. The 20S proteasome core was active within apoptotic exosome-like vesicles and controlled their immunogenic activity. Finally, we showed that proteasome activity in circulating exosome-like vesicles increased after vascular injury in mice. These findings open new avenues for predicting and controlling maladaptive humoral responses to apoptotic cell components that enhance the risk of rejection after transplantation

Association between skin diseases and severe bacterial infections in children: case-control study

BACKGROUND: Sepsis or bacteraemia, however rare, is a significant cause of high mortality and serious complications in children. In previous studies skin disease or skin infections were reported as risk factor. We hypothesize that children with sepsis or bacteraemia more often presented with skin diseases to the general practitioner (GP) than other children. If our hypothesis is true the GP could reduce the risk of sepsis or bacteraemia by managing skin diseases appropriately. METHODS: We performed a case-control study using data of children aged 0–17 years of the second Dutch national survey of general practice (2001) and the National Medical Registration of all hospital admissions in the Netherlands. Cases were defined as children who were hospitalized for sepsis or bacteraemia. We selected two control groups by matching each case with six controls. The first control group was randomly selected from the GP patient lists irrespective of hospital admission and GP consultation. The second control group was randomly sampled from those children who were hospitalized for other reasons than sepsis or bacteraemia. We calculated odds ratios and 95% confidence intervals (CI). A two-sided p-value less than 0.05 was considered significant in all tests. RESULTS: We found odds ratios for skin related GP consultations of 3.4 (95% CI: [1.1–10.8], p = 0.03) in cases versus GP controls and 1.4 (95% CI: [0.5–3.9], p = 0.44) in cases versus hospital controls. Children younger than three months had an odds ratio (cases/GP controls) of 9.2 (95% CI: [0.81–106.1], p = 0.07) and 4.0 (95% CI: [0.67–23.9], p = 0.12) among cases versus hospital controls. Although cases consulted the GP more often with skin diseases than their controls, the probability of a GP consultation for skin disease was only 5% among cases. CONCLUSION: There is evidence that children who were admitted due to sepsis or bacteraemia consulted the GP more often for skin diseases than other children, but the differences are not clinically relevant indicating that there is little opportunity for GPs to reduce the risk of sepsis and/or bacteraemia considerably by managing skin diseases appropriately

The PTEN Phosphatase Controls Intestinal Epithelial Cell Polarity and Barrier Function: Role in Colorectal Cancer Progression

The PTEN phosphatase acts on phosphatidylinositol 3,4,5-triphosphates resulting from phosphatidylinositol 3-kinase (PI3K) activation. PTEN expression has been shown to be decreased in colorectal cancer. Little is known however as to the specific cellular role of PTEN in human intestinal epithelial cells. The aim of this study was to investigate the role of PTEN in human colorectal cancer cells.Caco-2/15, HCT116 and CT26 cells were infected with recombinant lentiviruses expressing a shRNA specifically designed to knock-down PTEN. The impact of PTEN downregulation was analyzed on cell polarization and differentiation, intercellular junction integrity (expression of cell-cell adhesion proteins, barrier function), migration (wound assay), invasion (matrigel-coated transwells) and on tumor and metastasis formation in mice. Electron microscopy analysis showed that lentiviral infection of PTEN shRNA significantly inhibited Caco-2/15 cell polarization, functional differentiation and brush border development. A strong reduction in claudin 1, 3, 4 and 8 was also observed as well as a decrease in transepithelial resistance. Loss of PTEN expression increased the spreading, migration and invasion capacities of colorectal cancer cells in vitro. PTEN downregulation also increased tumor size following subcutaneous injection of colorectal cancer cells in nude mice. Finally, loss of PTEN expression in HCT116 and CT26, but not in Caco-2/15, led to an increase in their metastatic potential following tail-vein injections in mice.Altogether, these results indicate that PTEN controls cellular polarity, establishment of cell-cell junctions, paracellular permeability, migration and tumorigenic/metastatic potential of human colorectal cancer cells