Positive solutions for singular ϕ−\phi-Laplacian BVPs on the positive half-line

In this work, we are concerned with the existence of positive solutions for a $\phi$ Laplacian boundary value problem on the half-line. The results are proved using the fixed point index theory on cones of Banach spaces and the upper and lower solution technique. The nonlinearity may exhibit a singularity at the origin with respect to the solution. This singularity is treated by regularization and approximation together with compactness and sequential arguments

System of singular second-order differential equations with integral condition on the positive half-line

In this work, we are concerned with the existence and the multiplicity of nontrivial positive solutions for a boundary value problem of a system of second-order differential equations subject to an integral boundary condition and posed on the positive half-line. The positive nonlinearities depend on the solution and their derivatives and may have space singularities. New existence results of single and multiple solutions are obtained by means of the fixed point index theory on special cones in some weighted Banach space. Examples with numerical computations are included to illustrate the obtained existence theorems. This paper surveys and generalizes previous works

A class of second order BVPs on infinite intervals

In this work, we are concerned with a boundary value problem associated with a generalized Fisher-like equation. This equation involves an eigenvalue and a parameter which may be viewed as a wave speed. According to the behavior of the nonlinear source term, existence results of bounded solutions, positive solutions, classical as well as weak solutions are provided. We mainly use fixed point arguments

Axisymmetric High Temperature Jet Behaviours Based on a Lattice Boltzmann Computational Method. Part I: Argon Plasma

Résultats préliminaires. Projet d'article avant soumission à une revueThis article aims to address the issue of simulating plasma-jet by using an innovative computational approach namely the Lattice Boltzmann Method (LBM) from the point of view of extending the applications to simulating flows with temperature-dependent physical parameters. The work focuses on the phenomena occurring in plasma-jet that define the link between LBM lattice and physical lattice. High temperature dependence of the plasma parameters is considered. Argon characteristics fall into this category. This gas is one of the most ones used in plasma spraying. Complex thermal plasma jet phenomena and basis of classical methods in CFD (discretization, stability condition, modeling...), in one side, and the simple scheme of the Boltzmann equation which is particularly adopted for simulating gases flows, in the other side, give us the possibility of taking out the dynamic and thermal characteristics of this complex flow. An important section on validation of this model includes details of available reference results is presented and discussed. It focuses mainly on the validation of our results with previous numerical and experimental results based on the centerline temperature and velocity profiles, its distributions over the computational domain and eventually the effect of the computational domain size. The jet width, the Gaussian radial profiles and the effects of inlet quantities are analyzed. A real spraying configuration is also examined. The quality of the results shows a great efficiency for the lattice Boltzmann method

Genome-wide microRNA and gene analysis of mesenchymal stem cell chondrogenesis identifies an essential role and multiple targets for miR-140-5p

microRNAs (miRNAs) are abundantly expressed in development where they are critical determinants of cell differentiation and phenotype. Accordingly miRNAs are essential for normal skeletal development and chondrogenesis in particular. However, the question of which miRNAs are specific to the chondrocyte phenotype has not been fully addressed. Using microarray analysis of miRNA expression during mesenchymal stem cell chondrogenic differentiation and detailed examination of the role of essential differentiation factors, such as SOX9, TGF-b, and the cell condensation phase, we characterize the repertoire of specific miRNAs involved in chondrocyte development, highlighting in particular miR-140 and miR-455. Further with the use of mRNA microarray data we integrate miRNA expression and mRNA expression during chondrogenesis to underline the particular importance of miR-140, especially the -5p strand. We provide a detailed identification and validation of direct targets of miR-140-5p in both chondrogenesis and adult chondrocytes with the use of microarray and 30 UTR analysis. This emphasizes the diverse array of targets and pathways regulated by miR-140-5p. We are also able to confirm previous experimentally identified targets but, additionally, identify a novel positive regulation of the Wnt signaling pathway by miR-140-5p. Wnt signaling has a complex role in chondrogenesis and skeletal development and these findings illustrate a previously unidentified role for miR-140-5p in regulation of Wnt signaling in these processes. Together these developments further highlight the role of miRNAs during chondrogenesis to improve our understanding of chondrocyte development and guide cartilage tissue engineering

The Degasperis-Procesi equation as a non-metric Euler equation

In this paper we present a geometric interpretation of the periodic Degasperis-Procesi equation as the geodesic flow of a right invariant symmetric linear connection on the diffeomorphism group of the circle. We also show that for any evolution in the family of $b$-equations there is neither gain nor loss of the spatial regularity of solutions. This in turn allows us to view the Degasperis-Procesi and the Camassa-Holm equation as an ODE on the Fr\'echet space of all smooth functions on the circle.Comment: 17 page

Landscape of transcription in human cells

Eukaryotic cells make many types of primary and processed RNAs that are found either in specific subcellular compartments or throughout the cells. A complete catalogue of these RNAs is not yet available and their characteristic subcellular localizations are also poorly understood. Because RNA represents the direct output of the genetic information encoded by genomes and a significant proportion of a cell’s regulatory capabilities are focused on its synthesis, processing, transport, modification and translation, the generation of such a catalogue is crucial for understanding genome function. Here we report evidence that three-quarters of the human genome is capable of being transcribed, as well as observations about the range and levels of expression, localization, processing fates, regulatory regions and modifications of almost all currently annotated and thousands of previously unannotated RNAs. These observations, taken together, prompt a redefinition of the concept of a gene

On The Impact Of Family Versus Institutional Blockholders On Dividend Policy

This paper investigates the effect of not only the controlling shareholders but also their identity on dividend policy. For a large panel of French firms during the period 2006-2010, we find that the dividend payout ratio increases with the ownership concentration. However, this result changes with the identity of the largest shareholder. Family-controlled firms are more tempted to distribute lower dividends while firms dominated by institutional investors likely distribute higher dividends. Empirical results also reveal that firms with more independent directors are associated with higher dividend payout in contrast to US cross-listed firms

On a singular multi-point third-order boundary value problem on the half-line

summary:We establish not only sufficient but also necessary conditions for existence of solutions to a singular multi-point third-order boundary value problem posed on the half-line. Our existence results are based on the Krasnosel'skii fixed point theorem on cone compression and expansion. Nonexistence results are proved under suitable a priori estimates. The nonlinearity $f=f(t,x,y)$ which satisfies upper and lower-homogeneity conditions in the space variables $x, y$ may be also singular at time $t=0$. Two examples of applications are included to illustrate the existence theorems