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The Spatio-Temporal Interfaces within the Lesser Antilles Vegetation (The Example of the Island of Martinique)  [PDF]
Philippe Joseph
Open Access Library Journal (OALib Journal) , 2016, DOI: 10.4236/oalib.1102463
Abstract: The temporal vegetation dynamics and its spatial distribution cause discontinuities, border areas, ecotones and ecosystem heterogeneities, in other words biocenotics which result in a multitude of shapes and organic combinations. These interfaces are added variations due to vertical stratification involving specific architectures and behaviours towards light. These “interface environments” represent a plurality of plant biodiversity aspects and therefore ecological profiles which form the basis of the resilience processes. In the Lesser Antilles, Man has increased community complexity by increasing the number of eco-units1. As a result, the number of ecosystem interfaces increased so in some ways, he became the “architect” or “creator” of species biodiversity in the landscape through the ecosystem and the plant communities. Ultimately the current landscape is a mosaic of physiognomic units of unequal dimensions belonging to various successional stages. In the case of Martinique, we will discuss the complexity of the Lesser Antilles forest vegetation. The argument seeks to show its hierarchical organisation, the characteristics of its subsets and their spatial and temporal relationships.
Attentional Mechanisms for Interactive Image Exploration
Machrouh Joseph,Tarroux Philippe
EURASIP Journal on Advances in Signal Processing , 2005,
Abstract: A lot of work has been devoted to content-based image retrieval from large image databases. The traditional approaches are based on the analysis of the whole image content both in terms of low-level and semantic characteristics. We investigate in this paper an approach based on attentional mechanisms and active vision. We describe a visual architecture that combines bottom-up and top-down approaches for identifying regions of interest according to a given goal. We show that a coarse description of the searched target combined with a bottom-up saliency map provides an efficient way to find specified targets on images. The proposed system is a first step towards the development of software agents able to search for image content in image databases.
Membrane Scattering with M-Momentum Transfer
Joseph Polchinski,Philippe Pouliot
Physics , 1997, DOI: 10.1103/PhysRevD.56.6601
Abstract: Membrane scattering in m(atrix) theory is related to dynamics in three-dimensional $SU(2)$ gauge theory, with transfer of $p^{11}$ being an instanton process. We calculate the instanton amplitude and find precise agreement with the amplitude in eleven dimensional supergravity.
Chronic total occlusions for intermediate volume operators: An antegrade step-up algorithm allows high success in easy and intermediate difficult CTO lesions  [PDF]
Joren Maeremans, Philippe Selleslagh, Luigi Di Serafino, Emanuele Barbato, Joseph Dens
World Journal of Cardiovascular Diseases (WJCD) , 2013, DOI: 10.4236/wjcd.2013.39085
Abstract:

To improve the success rates of chronic total occlusion (CTO) intervention, a large range of CTO-dedicated guidewires (GWs), devices and techniques have been developed. However, such an abundant choice of materials confuses inexperienced operators. Therefore, the usefulness of a simple antegrade treatment algorithm with a limited set of GWs, for easy to intermediate lesions, was investigated. Between November 2011 and March 2013, 105 patients were included, who underwent CTO PCI following the algorithm. Lesions were classified according to the Multicenter CTO Registry of Japan score. Overall technical success was achieved in 77%. Study endpoint was successful GW crossing within 30 min and was reached in 57%. High success rates were achieved in easy (81%) and intermediate (64%) lesion types. In both types, a soft wire could successfully cross in 57% and 51% respectively, with the Fielder XT® (Asahi Intecc Co.) capable of crossing most commonly (90%). The proposed treatment algorithm simplifies the percutaneous treatment of easy to intermediate CTO lesions. However, it merits further evaluation, especially for operators/centers who perform a low to intermediate amount of CTO PCI.

Singular limits for the Riemann problem. General diffusion, relaxation, and boundary conditions
K. T. Joseph,Philippe G. LeFloch
Mathematics , 2008,
Abstract: We consider self-similar approximations of nonlinear hyperbolic systems in one space dimension with Riemann initial data and general diffusion matrix. We assume that the matrix of the system is strictly hyperbolic and the diffusion matrix is close to the identity. No genuine nonlinearity assumption is required. We show the existence of a smooth, self-similar solution which has bounded total variation, uniformly in the diffusion parameter. In the zero-diffusion limit, the solutions converge to a solution of the Riemann problem associated with the hyperbolic system. A similar result is established for the relaxation approximation and the boundary-value problem in a half-space for the same regularizations.
Boundary layers in weak solutions to hyperbolic conservation laws
K. T. Joseph,Philippe G. LeFloch
Mathematics , 2007, DOI: 10.1007/s002050050145
Abstract: This paper is concerned with the initial-boundary value problem for a nonlinear hyperbolic system of conservation laws. We study the boundary layers that may arise in approximations of entropy discontinuous solutions. We consider both the vanishing viscosity method and finite difference schemes (Lax-Friedrichs type schemes, Godunov scheme). We demonstrate that different regularization methods generate different boundary layers. Hence, the boundary condition can be formulated only if an approximation scheme is selected first. Assuming solely uniform L\infty bounds on the approximate solutions and so dealing with L\infty solutions, we derive several entropy inequalities satisfied by the boundary layer in each case under consideration. A Young measure is introduced to describe the boundary trace. When a uniform bound on the total variation is available, the boundary Young measure reduces to a Dirac mass. Form the above analysis, we deduce several formulations for the boundary condition which apply whether the boundary is characteristic or not. Each formulation is based a set of admissible boundary values, following Dubois and LeFloch's terminology in ``Boundary conditions for nonlinear hyperbolic systems of conservation laws'', J. Diff. Equa. 71 (1988), 93--122. The local structure of those sets and the well-posedness of the corresponding initial-boundary value problem are investigated. The results are illustrated with convex and nonconvex conservation laws and examples from continuum mechanics.
Singular limits in phase dynamics with physical viscosity and capillarity
K. T. Joseph,Philippe G. LeFloch
Mathematics , 2006,
Abstract: Following pioneering work by Fan and Slemrod who studied the effect of artificial viscosity terms, we consider the system of conservation laws arising in liquid-vapor phase dynamics with {\sl physical} viscosity and capillarity effects taken into account. Following Dafermos we consider self-similar solutions to the Riemann problem and establish uniform total variation bounds, allowing us to deduce new existence results. Our analysis cover both the hyperbolic and the hyperbolic-elliptic regimes and apply to arbitrarily large Riemann data. The proofs rely on a new technique of reduction to two coupled scalar equations associated with the two wave fans of the system. Strong $L^1$ convergence to a weak solution of bounded variation is established in the hyperbolic regime, while in the hyperbolic-elliptic regime a stationary singularity near the axis separating the two wave fans, or more generally an almost-stationary oscillating wave pattern (of thickness depending upon the capillarity-viscosity ratio) are observed which prevent the solution to have globally bounded variation.
An Algebra to Merge Heterogeneous Classifiers
Philippe J. Giabbanelli,Joseph G. Peters
Computer Science , 2015,
Abstract: In distributed classification, each learner observes its environment and deduces a classifier. As a learner has only a local view of its environment, classifiers can be exchanged among the learners and integrated, or merged, to improve accuracy. However, the operation of merging is not defined for most classifiers. Furthermore, the classifiers that have to be merged may be of different types in settings such as ad-hoc networks in which several generations of sensors may be creating classifiers. We introduce decision spaces as a framework for merging possibly different classifiers. We formally study the merging operation as an algebra, and prove that it satisfies a desirable set of properties. The impact of time is discussed for the two main data mining settings. Firstly, decision spaces can naturally be used with non-stationary distributions, such as the data collected by sensor networks, as the impact of a model decays over time. Secondly, we introduce an approach for stationary distributions, such as homogeneous databases partitioned over different learners, which ensures that all models have the same impact. We also present a method that uses storage flexibly to achieve different types of decay for non-stationary distributions. Finally, we show that the algebraic approach developed for merging can also be used to analyze the behaviour of other operators.
Disparities in the Diagnosis of Hypertrophic Obstructive Cardiomyopathy: A Narrative Review of Current Literature
Joseph Burns,Philippe Jean-Pierre
- , 2018, DOI: 10.1155/2018/3750879
Abstract:
Outcome of delivery in nulliparous teenagers aged less than 17 years: the cameroon university centre hospital experience  [PDF]
Pierre Marie Tebeu, Inoussa Nsangou, Philippe Nana Njotang, Paul Théodore Tjek Biyaga, Anderson Sama Doh, Joseph Nelson Fomulu
Open Journal of Obstetrics and Gynecology (OJOG) , 2011, DOI: 10.4236/ojog.2011.12010
Abstract: In a previous study at the Yaoundé-Cameroon University Centre Hospital, we found that delivery at extreme ages of reproductive health was associated with several fetal and maternal risks. We conducted this study aimed at testing the hypothesis that deliveries by teenagers were associated with increased risk. Data collection was retrospective from delivery room registers at between 01/01/1996 and 31/12/2000. Data were collected in singleton pregnancies. The identification of each nulliparous woman aged less than 17 years was followed by that of 4 nulliparous women aged 20 - 29 years following her in the order of delivery. Since it was possible to have consecutive nulliparous teenage pregnancies before four deliveries in women in their twenties, we finally compared 65 cases of teenagers delivery with 218 cases of delivery in women aged 20 - 29 years. The difference was considered significant if p value was less than 0.05. Odd ratio with 95% confidence interval was used to measure the effect of age on the major outcomes. At univariate analysis, the risk of delivery by caesarean section for teenagers (21.5%) was significantly high compared to women in their twenties (11.5%), (OR: 2.1; 95%CI: 1.0 - 4.1; p = 0.041). Similar observation was found for stillbirth delivery with 12.3% by teenagers compared to 5.0% by women in their twenties (OR: 2.7; 95%CI: 1.0 - 7.1; p = 0.044). The risk of premature delivery by teenagers (30.8%) was also significantly increased compared to women in their twenties (12.4%) (OR: 3.6; 95%CI: 1.8 - 7.1; p = 0.0002). After adjustment for different factors associated with the occurrence of several risks, only pre term delivery remained significantly increased at teenage (OR: 3.7; 95%CI: 1.8 - 7.6; p = 0.003). These findings underscore the importance of public health programs in preventing the pregnancy in teenagers, and in developing age-appropriate intervention.
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