175 research outputs found
Explaining Adherence Success in Sub-Saharan Africa: An Ethnographic Study
Using ethnographic data from Nigeria, Tanzania, and Uganda, Norma Ware and colleagues examine why levels of adherence to HIV/AIDS drugs are so much higher in sub-Saharan Africa than in North America
Equity and health policy in Africa: Using concept mapping in Moore (Burkina Faso)
<p>Abstract</p> <p>Background</p> <p>This methodological article is based on a health policy research project conducted in Burkina Faso (West Africa). Concept mapping (CM) was used as a research method to understand the local views of equity among stakeholders, who were concerned by the health policy under consideration. While this technique has been used in North America and elsewhere, to our knowledge it has not yet been applied in Africa in any vernacular language. Its application raises many issues and certain methodological limitations. Our objective in this article is to present its use in this particular context, and to share a number of methodological observations on the subject.</p> <p>Methods</p> <p>Two CMs were done among two different groups of local stakeholders following four steps: generating ideas, structuring the ideas, computing maps using multidimensional scaling and cluster analysis methods, and interpreting maps. Fifteen nurses were invited to take part in the study, all of whom had undergone training on health policies. Of these, nine nurses (60%) ultimately attended the two-day meeting, conducted in French. Of 45 members of village health committees who attended training on health policies, only eight were literate in the local language (Moore). Seven of these (88%) came to the meeting.</p> <p>Results</p> <p>The local perception of equity seems close to the egalitarian model. The actors are not ready to compromise social stability and peace for the benefit of the worst-off. The discussion on the methodological limitations of CM raises the limitations of asking a single question in Moore and the challenge of translating a concept as complex as equity. While the translation of equity into Moore undoubtedly oriented the discussions toward social relations, we believe that, in the context of this study, the open-ended question concerning social justice has a threefold relevance. At the same time, those limitations were transformed into strengths. We understand that it was essential to resort to the focus group approach to explore deeply a complex subject such as equity, which became, after the two CMs, one of the important topics of the research.</p> <p>Conclusion</p> <p>Using this technique in a new context was not the easiest thing to do. Nevertheless, contrary to what local organizers thought when we explained to them this "crazy" idea of applying the technique in Moore with peasants, we believe we have shown that it was feasible, even with persons not literate in French.</p
Asymptotic theory of time-varying social networks with heterogeneous activity and tie allocation
The dynamic of social networks is driven by the interplay between diverse mechanisms that still challenge our theoretical and modelling efforts. Amongst them, two are known to play a central role in shaping the networks evolution, namely the heterogeneous propensity of individuals to i) be socially active and ii) establish a new social relationships with their alters. Here, we empirically characterise these two mechanisms in seven real networks describing temporal human interactions in three different settings: scientific collaborations, Twitter mentions, and mobile phone calls. We find that the individuals’ social activity and their strategy in choosing ties where to allocate their social interactions can be quantitatively described and encoded in a simple stochastic network modelling framework. The Master Equation of the model can be solved in the asymptotic limit. The analytical solutions provide an explicit description of both the system dynamic and the dynamical scaling laws characterising crucial aspects about the evolution of the networks. The analytical predictions match with accuracy the empirical observations, thus validating the theoretical approach. Our results provide a rigorous dynamical system framework that can be extended to include other processes shaping social dynamics and to generate data driven predictions for the asymptotic behaviour of social networks
A CRÍTICA E OS MOMENTOS CRÍTICOS: DE LA JUSTIFICATION E A GUINADA PRAGMÁTICA NA SOCIOLOGIA FRANCESA
Mise en évidence chez le rat de la somatotopie des vibrisses dans une nouvelle aire somatosensorielle secondaire et dans le cortex multisensoriel audio-somatosensoriel
Les vibrisses du rat possèdent une carte d'identité dans SIBF ("les tonneaux"). Nous avons recherché cette somatotopie dans d'autres structures tactiles du cortex. Dans ce but, nous avons enregistré des potentiels de champ avec une grille d'électrodes posée sur le cortex et développé une méthode d'analyse pour chaque individu fournissant des informations peu accessibles par une analyse EEG classique basée sur les moyennes entre animaux. Notre approche permet d'obtenir pour chaque rat une cartographie grand champ (~5mm) avec une excellente résolution spatiale (~100 m). Nous avons analysé trois aires corticales peu connues : (1) nous confirmons la somatotopie des vibrisses dans SII; (2) nous montrons pour la première fois une telle organisation dans SII caudal une aire secondaire peu étudiée; (3) nous avons découvert l'existence, lors de stimulations bimodales (un clic sonore et une déflexion d'une vibrisse), d'une somatotopie des vibrisses dans MZ, une aire audio-somatosensorielle.PARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF
Sélectivité directionnelle dans les couches II/III du cortex somatosensoriel primaire du rat étudiée par microscopie à deux photons in vivo et développements en acousto-optique appliqués à la microscopie multiphotonique.
Ce travail a permis d introduire des systèmes de balayage acousto-optiques dans la microscopie multiphotonique. Le balayage point par point permet d augmenter considérablement la résolution temporelle ou le rapport signal-sur-bruit. J ai donc compensé les déformations spatio-temporelles par des systèmes de pré-compensation. Pour améliorer la transmission globale du système une nouvelle technique de compensation a été montrée. Ce système est ajustable en fonction de la longueur d onde requise par le fluorophore et offre de grands champs de balayage. Ensuite, une étude de l organisation fonctionnelle à l échelle cellulaire du cortex somatosensoriel primaire des vibrisses dans le rat in vivo a été effectuée. A l échelle d un tonneau, l organisation spatiale des neurones en fonction des préférences directionnelles a été étudiée. La microscopie bi-photonique a permis de montrer que dans les rats adultes, contrairement aux rats jeunes, une organisation somatotopique est bien présente.PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF
Focusing light through dynamical samples using fast continuous wavefront optimization
International audienceWe describe a fast continuous optimization wavefront shaping system able to focus light through dynamic scattering media. A micro-electro-mechanical system-based spatial light modulator, a fast photodetector, and field programmable gate array electronics are combined to implement a continuous optimization of a wavefront with a single-mode optimization rate of 4.1 kHz. The system performances are demonstrated by focusing light through colloidal solutions of TiO2 particles in glycerol with tunable temporal stability
- …