Maîtrise de la fécondité et planification familiale au Sud

Contrairement à la migration et à la mortalité, la fécondité a été relativement peu étudiée au Burkina Faso. Sur la base des recherches sur le terrain menées par des anthropologues, géographes, économistes, historiens, qui ont documenté différents aspects de l'organisation sociale et de la dynamique des systèmes agraires en pays mossi, l'article passe en revue les contraintes environnementales auxquelles sont confrontées les populations et les grands traits de l'organisation socio-économique qui sous-tendent la production et la reproduction en milieu mossi. Il apparaît que les contraintes qui en découlent, tant pour les hommes que pour les femmes, déterminent des stratégies de survie où la forte fécondité joue encore un rôle essentiel. (Résumé d'auteur

Acute Otitis Media

Acute otitis media (AOM) is a common childhood illness that almost every child experiences by the time that they are five years of age. AOM is a self-limiting condition in which analgesics are thought to be efficient in treating the pain in these children. Literature was reviewed and the information that was compiled was presented as a PowerPoint presentationto a local group of mothers with children under the age of 6 years. This information explained the anatomy of the ear, the risk factors for AOM, treatment options, and preventative measures for AOM. As a future Nurse Practitioner, it is imperative that we understand what the needs of the parents are for the children that we are evaluating. It is our duty to provide the education needed and to share in the informed decision making process with the parents when a child is faced with an illness. We need to empower parents and providers to take a stand in a time where overprescribing is a global issue and leading us down a pathway of drug resistance. This is a multifactoral condition where guidelines are in place, but now must be revisited to ensure parents are aware of the treatment plans used to effectively manage AOM

Dissociating visuo-spatial and verbal working memory: It’s all in the features

Echoing many of the themes of the seminal work of Atkinson and Shiffrin (1968), this paper uses the Feature Model (Nairne, 1988, 1990; Neath & Nairne, 1995) to account for performance in working memory tasks. The Brooks verbal and visuo-spatial matrix tasks were performed alone, with articulatory suppression, or with a spatial suppression task; the results produced the expected dissociation. We used Approximate Bayesian Computation techniques to fit the Feature Model to the data and showed that the similarity-based interference process implemented in the model accounted for the data patterns well. We then fit the model to data from Guérard and Tremblay (2008); the latter study produced a double dissociation while calling upon more typical order reconstruction tasks. Again, the model performed well. The findings show that a double dissociation can be modelled without appealing to separate systems for verbal and visuo-spatial processing. The latter findings are significant as the Feature Model had not been used to model this type of dissociation before; importantly, this is also the first time the model is quantitatively fit to data. For the demonstration provided here, modularity was unnecessary if two assumptions were made: (1) the main difference between spatial and verbal working memory tasks is the features that are encoded; (2) secondary tasks selectively interfere with primary tasks to the extent that both tasks involve similar features. It is argued that a feature-based view is more parsimonious (see Morey, 2018) and offers flexibility in accounting for multiple benchmark effects in the field

How does the chromatin fiber deal with topological constraints?

In the nuclei of eukaryotic cells, DNA is packaged through several levels of compaction in an orderly retrievable way that enables the correct regulation of gene expression. The functional dynamics of this assembly involves the unwinding of the so-called 30 nm chromatin fiber and accordingly imposes strong topological constraints. We present a general method for computing both the twist and the writhe of any winding pattern. An explicit derivation is implemented for the chromatin fiber which provides the linking number of DNA in eukaryotic chromosomes. We show that there exists one and only one unwinding path which satisfies both topological and mechanical constraints that DNA has to deal with during condensation/decondensation processes.Comment: Presented in Nature "News and views in brief" Vol. 429 (13 May 2004). Movies available at http://www.lptl.jussieu.fr/recherche/operationE_fichiers/Page_figurePRL.htm

Complex microwave conductivity of Pr1.85_{1.85}Ce0.15_{0.15}CuO4−δ_{4-\delta} thin films using a cavity perturbation method

We report a study of the microwave conductivity of electron-doped Pr$_{1.85}$Ce$_{0.15}$CuO$_{4-\delta}$ superconducting thin films using a cavity perturbation technique. The relative frequency shifts obtained for the samples placed at a maximum electric field location in the cavity are treated using the high conductivity limit presented recently by Peligrad $\textit{et}$ $\textit{al.}$ Using two resonance modes, TE$_{102}$ (16.5 GHz) and TE$_{101}$ (13 GHz) of the same cavity, only one adjustable parameter $\Gamma$ is needed to link the frequency shifts of an empty cavity to the ones of a cavity loaded with a perfect conductor. Moreover, by studying different sample configurations, we can relate the substrate effects on the frequency shifts to a scaling factor. These procedures allow us to extract the temperature dependence of the complex penetration depth and the complex microwave conductivity of two films with different quality. Our data confirm that all the physical properties of the superconducting state are consistent with an order parameter with lines of nodes. Moreover, we demonstrate the high sensitivity of these properties on the quality of the films

Divergence of the Chaotic Layer Width and Strong Acceleration of the Spatial Chaotic Transport in Periodic Systems Driven by an Adiabatic ac Force

We show for the first time that a {\it weak} perturbation in a Hamiltonian system may lead to an arbitrarily {\it wide} chaotic layer and {\it fast} chaotic transport. This {\it generic} effect occurs in any spatially periodic Hamiltonian system subject to a sufficiently slow ac force. We explain it and develop an explicit theory for the layer width, verified in simulations. Chaotic spatial transport as well as applications to the diffusion of particles on surfaces, threshold devices and others are discussed.Comment: 4 pages including 3 EPS figures, this is an improved version of the paper (accepted to PRL, 2005