Search results for "STEP"

Using Y-chromosome capture enrichment to resolve haplogroup H2 shows new evidence for a two-path Neolithic expansion to Western Europe

2021

Uniparentally-inherited markers on mitochondrial DNA (mtDNA) and the non-recombining regions of the Y chromosome (NRY), have been used for the past 30 years to investigate the history of humans from a maternal and paternal perspective. Researchers have preferred mtDNA due to its abundance in the cells, and comparatively high substitution rate. Conversely, the NRY is less susceptible to back mutations and saturation, and is potentially more informative than mtDNA owing to its longer sequence length. However, due to comparatively poor NRY coverage via shotgun sequencing, and the relatively low and biased representation of Y-chromosome variants on capture assays such as the 1240 k, ancient DNA…

Etude numérique d'équations aux dérivées partielles non linéaires et dispersives

2011

Numerical analysis becomes a powerful resource in the study of partial differential equations (PDEs), allowing to illustrate existing theorems and find conjectures. By using sophisticated methods, questions which seem inaccessible before, like rapid oscillations or blow-up of solutions can be addressed in an approached way. Rapid oscillations in solutions are observed in dispersive PDEs without dissipation where solutions of the corresponding PDEs without dispersion present shocks. To solve numerically these oscillations, the use of efficient methods without using artificial numerical dissipation is necessary, in particular in the study of PDEs in some dimensions, done in this work. As stud…

Diffusion stabilizes cavity solitons in bidirectional lasers

2009

We study the influence of field diffusion on the spatial localized structures (cavity solitons) recently predicted in bidirectional lasers. We find twofold positive role of the diffusion: 1) it increases the stability range of the individual (isolated) solitons; 2) it reduces the long-range interaction between the cavity solitons. Latter allows the independent manipulation (writing and erasing) of individual cavity solitons.

A kinetic model for the oxidation of benzenethiol catalyzed by the [MoVIO2(O2CC(S)(C6H5)2)2]2− complex intercalated in a Zn(II)–Al(III) layered doubl…

2009

Abstract The heterogeneous oxidation of benzenethiol catalyzed by the dianionic bis(2-sulfanyl-2,2-diphenylethanoxycarbonyl) dioxomolybdate (VI) complex intercalated into a Zn(II)–Al(III) layered double hydroxide (LDH) host have been investigated under aerobic conditions. The kinetics of the system has been analysed in detail. In ethanol, the benzenethiol is cleanly oxidized to diphenyl disulfide in the acidic media provided by the protonic resin Amberlite IR-120(H). The reaction is second-order in benzenethiol, and the apparent rate coefficient has been found to be proportional to the catalyst weight and inversely proportional to the initial concentration of the substrate. A catalytic cycl…

The λ-Error Order in Multivariate Interpolation

2005

The aim of this article is to introduce and to study a generalization of the error order of interpolation, named λ – error order of interpolation. This generalization makes possible a deeper analysis of the error in the interpolation process. We derived the general form of the λ – error order of interpolation and then we applied it for many choices of the functional λ.

The symmetric boundary element method for unilateral contact problems

2008

Abstract On the basis of the boundary integral equation method, in its symmetric formulation, the frictionless unilateral contact between two elastic bodies has been studied. A boundary discretization by boundary elements leads to an algebraic formulation in the form of a linear complementarity problem. In this paper the process of contact or detachment is obtained through a step by step analysis by using generalized (weighted) quantities as the check elements: the detachment or the contact phenomenon may happen when the weighted traction or the weighted displacement is greater than the weighted cohesion or weighted minimum reference gap, respectively. The applications are performed by usin…

Localization and separation of solutions for Fredholm integral equations

2020

[EN] In this paper, we establish a qualitative study of nonlinear Fredholm integral equations, where we will carry out a study on the localization and separation of solutions. Moreover, we consider an efficient algorithm to approximate a solution. To do this, we study the semilocal convergence of an efficient third order iterative scheme for solving nonlinear Fredholm integral equations under mild conditions. The novelty of our work lies in the fact that this study involves first order Frechet derivative and mild conditions. A numerical example involving nonlinear Fredholm integral equations, is solved to show the domains of existence and uniqueness of solutions. The applicability of the it…

Modello di distribuzione e di idoneità ambientale dell'occhione, Burhinus oedicnemus

2009

Niveles y patrones de actividad física en sesiones de motricidad infantil basadas en el juego libre

2017

[Resumen] El objetivo del estudio consistió en analizar los niveles y patrones de actividad física de niñas y niños de educación infantil en dos sesiones de motricidad centradas en el juego libre. Participaron 32 estudiantes, de edades comprendidas entre los 48 y 54 meses y pertenecientes al segundo ciclo de educación infantil, de un colegio público de la Provincia de València, España. Los niveles y patrones de actividad física se determinaron a través de podometría y de un sistema observacional. El modelo A consistió en una sesión de juego libre por rincones-tiempo, mientras que el modelo B consistió en una sesión de juego libre por rincones-libre elección. Los resultados muestran que más …

Diurnal habitat suitability for a Mediterranean steppeland bird, identified by Ecological Niche Factor Analysis

2011

Context The negative effects of agricultural intensification and policies, use of pesticides, fertilisers and mechanised harvesting on several populations of pseudo-steppe birds have increasingly required more detailed and effective habitat suitability models. Distribution models of farmland species are prone to incur recordings of false absence data. Ecological Niche Factor Analysis (ENFA) allows identification of environmental predictors of species distribution by using presence data only. Aims We quantified the diurnal habitat preferences and niche width of one steppe species, the stone curlew (Burhinus oedicnemus), with unfavourable conservations status in a Mediterranean area and recl…