Réseau social et inégalités de réinsertion

Le réseau social d'un individu joue un rôle important dans sa réinsertion. En Suisse, entre 30 et 40% des postes sont obtenus grâce à l'entourage (famille, amis, anciens collègues de travail, etc.). Nouvellement constituée, une base de données permet d'analyser les caractéristiques et le fonctionnement des réseaux sociaux

Amaurosis after spine surgery: survey of the literature and discussion of one case

Postoperative vision loss (POVL) associated with spine surgery is a well known, albeit very rare complication. POVL incidence after spinal surgery ranges from 0.028 to 0.2%; however, due to the increase in number and duration of annual complex spinal operations, the incidence may increase. Origin and pathogenesis of POVL remain frequently unknown. A 73-year-old patient presented with lumbar disc herniation with associated neurological deficits after conservative pre-treatment at a peripheral hospital. Known comorbidities included arterial hypertension, moderate arterial sclerosis, diabetes mellitus type 2, mildly elevated blood lipids and treated prostate gland cancer. During lumbar spine surgery in modified prone position the patient presented with an acute episode of severe hypotension, which required treatment with catecholamines and Trendelenburg positioning. Three hours postoperatively, a visual loss in the right eye occurred, resulting in a complete amaurosis. Antihypertensive medication, arteriosclerosis and intraoperative hypotension are possible causes for the POVL. Intraoperative administration of catecholamines and Trendelenburg positioning for treatment of systemic hypotension might further compromise ocular perfusion. In patients with comorbidities compromising arterial blood pressure, blood circulation and microcirculation, POVL must be considered as a severe postoperative complication. It is recommended to inform patients about such complications and obtain preoperative informed consent regarding POVL. Any recent modification of antihypertensive medication must be reported and analysed for potential intraoperative hemodynamic consequences, prior to spine surgery in prone positio

The worldwide air transportation network: Anomalous centrality, community structure, and cities' global roles

We analyze the global structure of the world-wide air transportation network, a critical infrastructure with an enormous impact on local, national, and international economies. We find that the world-wide air transportation network is a scale-free small-world network. In contrast to the prediction of scale-free network models, however, we find that the most connected cities are not necessarily the most central, resulting in anomalous values of the centrality. We demonstrate that these anomalies arise because of the multi-community structure of the network. We identify the communities in the air transportation network and show that the community structure cannot be explained solely based on geographical constraints, and that geo-political considerations have to be taken into account. We identify each city's global role based on its pattern of inter- and intra-community connections, which enables us to obtain scale-specific representations of the network.Comment: Revised versio

The effects of spatial constraints on the evolution of weighted complex networks

Motivated by the empirical analysis of the air transportation system, we define a network model that includes geographical attributes along with topological and weight (traffic) properties. The introduction of geographical attributes is made by constraining the network in real space. Interestingly, the inclusion of geometrical features induces non-trivial correlations between the weights, the connectivity pattern and the actual spatial distances of vertices. The model also recovers the emergence of anomalous fluctuations in the betweenness-degree correlation function as first observed by Guimer\`a and Amaral [Eur. Phys. J. B {\bf 38}, 381 (2004)]. The presented results suggest that the interplay between weight dynamics and spatial constraints is a key ingredient in order to understand the formation of real-world weighted networks

Online-Styleguide

Für Unternehmen ist die Motivation Styleguides für die Entwicklung von grafischen User-Interfaces zu erstellen und einzusetzen vielfältig. Durch den Einsatz von Styleguides lassen sich Entwicklungs- und Schulungskosten senken, die Kundenzufriedenheit erhöhen und den Bekanntheitsgrad einer Marke oder eines Produktes steigern. Kaum jemand, der sich mit User-Interfaces befasst, würde da-her bezweifeln, dass Styleguides sinnvoll und nützlich sind. Jedoch werden in der Literatur diverse Gründe für ein „Scheitern“ von Styleguides angeführt. Einer davon ist, dass sie oft entweder nur in Papierform oder als elektronisches Dokument verfügbar sind, was deren Änderung oder Erweiterung erschwert. Ein Problem ist oft auch die mangelnde Akzeptanz des Styleguides seitens der Personen, die sie anwenden sollen, jedoch nicht in deren Erstellungsprozess involviert wurden. Im Kern be-deutet dies, dass mangelnde Kollaboration und Kommunikation von Erstellern und Anwendern von Styleguides ein Grund für das Scheitern sein können. Diese Studie befasst sich mit der Theorie und Problematik von Styleguides, gibt Empfehlungen für deren Einsatz im Umfeld von Unternehmen und Projekten und zeigt ein Konzept für ein System zur kollaborativen Erstellung, Verwaltung und Verwendung projektspezifischer Styleguides, das anhand eines benutzerzentrierten Vorgehens erarbeitet wird. Die Grundlage des Konzeptes bilden Recherchen in der Literatur zur Theorie und Problematik von Styleguides und Recherchen in der Praxis mittels Interviews mit Personen in verschiedenen Firmen, die in ihrer jeweiligen Arbeitsrolle mit Styleguides konfrontiert sind. Auf Basis der dabei gewonnen Daten, werden Personas bestimmt, Anforderungen definiert und diverse weitere Spezifikationen festgelegt. Daraus wird ein konzeptioneller Prototyp abgeleitet und evaluiert

Application of Data Mining in Air Traffic Forecasting

The main goal of the study centers on developing a model for the purpose of air traffic forecasting by using off-the-shelf data mining and machine learning techniques. Although data driven modeling has been extensively applied in the aviation sector, little research has been done in the area of air traffic forecasting. This study is inspired by previous research focused on improving the Federal Aviation Administration (FAA) Terminal Area Forecasting (TAF) methodology, which historically assumed that the US air transportation system (ATS) network structure was static. Recent developments use data mining algorithms to predict the likelihood of previously un-connected airport-pairs being connected in the future, and the likelihood of connected airport-pairs becoming un-connected. Despite the innovation of this research, it does not focus on improving the FAA’s existing methodology for forecasting future air traffic levels on existing routes, which is based on relatively simple regression and growth models. We investigate different approaches for improving and developing new features within the existing data mining applications in air traffic forecasting. We focus particularly on predicting detailed traffic information for the US ATS. Initially, a 2-stage log-log model is applied to establish the significance of different inputs and to identify issues of endogeneity and multi-colinearity, while maintaining the simplicity of current models. Although the model shows high goodness of fit, it tested positive for both mentioned issues as well as presenting problems with causality. With the objective of solving these issues, a 3-stage model that is under development is introduced. This model employs logistic regression and discrete choice modelling. As part of future work, machine learning techniques such as clustering and neural networks will be applied to improve this model’s performance

L’impact des réseaux sociaux sur le retour à l’emploi des chômeurs

Mit einer deutschen Zusammenfassung Etude de la ‚troisième vague‘ des évaluations de la politique du marché du travailLe fait de disposer d’un bon réseau d’amis et de connaissances constitue un important avantage pour les recherches d’emploi. Cependant, il existe peu d’analyses du rôle des ré-seaux sociaux sur la réinsertion professionnelle des sans-emploi. Notre étude présente une analyse de l’importance des contacts pour la sortie du chômage et de l’utilisation qui en est faite pour retrouver un travail. Bei der Arbeitssuche ist es ein klarer Vorteil, über einen grossen Freundes- und Bekanntenkreis zu verfügen. Allerdings wurde die Rolle sozialer Netzwerke bei der Wiedereingliederung in den Arbeits-markt bisher kaum wissenschaftlich analysiert. Eine Studie zum Kanton Waadt kommt zum Schluss, dass soziale Kontakte von zentraler Bedeutung sind, auch wenn ihr Einfluss je nach Personengruppe und Branche variiert. Eine Sensibilisierung für die Thematik kann den beruflichen Wiedereinstieg ebenfalls begünstigen

Inequality in social capital and labour market re-entry among unemployed people

Research on social capital inequality has tended to emphasize the fact that the distribution of social capital follows that of other resources, with the result that it tends to amplify social inequalities. More elaborated theoretical accounts and some empirical studies suggest, however, that under some circumstances, social capital can actually compensate for disadvantage in social position. In this paper we test these competing hypotheses on a population of newly unemployed people in the Swiss canton of Vaud (N= 3'521). It appears that in most cases the distribution of social capital reflects that of other dimensions of stratification that are associated with labour market disadvantage, such as education, immigrant status, gender, and occupational status. On one important component of social capital, the number of work-related contacts, some immigrant groups score better than Swiss nationals. While this is an important predictor of early exit from unemployment, it fails to translate into an improvement of labour market prospects for the relevant immigrant groups, most likely because its effect is counteracted by more powerful forces such as inequality in skills and discrimination