Combination of theoretical analysis and FTIR to study the photocurrent oscillation of Silicon in fluoride media

To deepening our knowledge of the behaviour of the silicon/electrolyte interface, a study of photocurrent oscillations on silicon in fluoride concentration c F =0.033 M is realized, and as a confirmation of the result the investigation is extrapolated to a variety of electrolyte compositions. The etch rates of anodic oxides in diluted fluoride solutions have been determined by using a new approach of the analysis of anodic current oscillations. The time dependent thickness of the anodic oxide has been measured by in-situ FTIR and can be simulated considering only the time dependent current and the etch rate.To deepening our knowledge of the behaviour of the silicon/electrolyte interface, a study of photocurrent oscillations on silicon in fluoride concentration c F =0.033 M is realized, and as a confirmation of the result the investigation is extrapolated to a variety of electrolyte compositions. The etch rates of anodic oxides in diluted fluoride solutions have been determined by using a new approach of the analysis of anodic current oscillations. The time dependent thickness of the anodic oxide has been measured by in-situ FTIR and can be simulated considering only the time dependent current and the etch rate

A web services composition approach based on software agents and context

We present an agent-based and context-oriented approach for Web services composition. A Web service is an accessible application that other applications and humans can discover and trigger to satisfy various needs. Due to the complexity of Web services composition, we consider two concepts to reduce this complexity: Software agent and context. A software agent is an autonomous entity that acts on behalf of users, whereas context is any information relevant to characterize a situation. During composition, software agents engage conversations with their peers to agree on the Web services that will participate in the composition

Revisión taxonómica del género Luciobarbus Heckel, 1843 (Actinopterygii, Cyprinidae) del noroeste de Marruecos con la descripción de tres nuevas especies

[EN] The genus Luciobarbus in Morocco presents high diversification, in contrast to the generally impoverished freshwater fish fauna from North Africa. Within Morocco the northern area is one of the least studied territories, due to both its historical background and the limited accessibility of many regions. Previous phylogenetic studies identified Luciobarbus populations that are morphologically and genetically differentiated, to the same extent as others already recognized as separate species. The aim of this work is to describe these populations as distinct species, based on morphological, meristic, and genetic traits.[ES] En Marruecos el género Luciobarbus está altamente diversificado, en comparación con la empobrecida fauna de peces de agua dulce del norte de África. Dentro de Marruecos la región norte es una de las áreas menos estudiadas, por motivos históricos y también por la poca accesibilidad en algunas de sus regiones. Los estudios filogenéticos previos para esta área han señalado la existencia de poblaciones pertenecientes al género Luciobarbus tan diferenciadas morfológica y genéticamente como otras que ya habían sido reconocidas como diferentes especies. En este trabajo describimos estas poblaciones como diferentes taxa, en base a caracteres morfológicos, merísticos y genéticos.Peer Reviewe

The influence of phosphorus content on magnetic anisotropy in ferromagnetic (Ga, Mn) (As, P)/GaAs thin films

International audienceThe magnetic anisotropy of the ferromagnetic semiconductor (Ga, Mn) (As, P) is studied in a material-specific microscopic k . p approach. We calculate the electronic energy band structure of (Ga, Mn) (As, P) quaternary ferromagnetic alloys using a 40-band k . p model and taking into account the s, p-d exchange interaction and the strain of the (Ga, Mn) (As, P) layer on a GaAs substrate. We determine the variations of the carrier effective masses in the strained (Ga, Mn) (As, P)/GaAs system. The magnetic anisotropy constants obtained from our simulations using a mean-field model are compared with the experimental ones determined by ferromagnetic resonance spectroscopy on a set of samples with constant manganese concentration and varying phosphorus concentration. An excellent quantitative agreement between experiment and theory is found for the uniaxial out-of-plane and cubic in-plane anisotropy parameters

Taxonomía de las especies reófilas del género Luciobarbus Heckel, 1842 (Actinopterygii, Cyprinidae) de Marruecos con la descripción de dos nuevas especies

[EN] The genus Luciobarbus Heckel, 1843 is characterized by medium to large fish species occurring in large rivers and downstream zones with slow-moving waters. Remarkably also rheophilic Luciobarbus occur in Morocco, which are of small size and exhibit distinct morphological traits as well as different habitat requirements. These rheophilic species have traditionally been assigned to Luciobarbus nasus (Günther, 1874) and L. magniatlantis (Pellegrin, 1919), although some authors consider L. magniatlantis as a junior synonym of L. nasus. This lack of consensus on the taxonomy of rheophilic barbs is constrained by limited population studies that do not encompass their entire distribution range. Using molecular, morphometric, and osteological data we studied populations of rheophilic barbs of three drainage basins in which they are currently present: Tensift, Moulouya and Oum er Rbia. Our results clearly identified the rheophilic barbs of each basin as different species. The species Luciobarbus magniatlantis is a well-recognized species endemic to Tensift Basin. In contrast, the investigated populations from the Moulouya and Oum er Rbia basins could not be assigned to any previously described species. Consequently, we describe two new Luciobarbus species in the Moulouya and Oum er Rbia basins.[ES] El género Luciobarbus Heckel, 1843 se caracteriza por presentar especies de medio y gran tamaño que viven en las zonas bajas de grandes ríos con aguas lentas. Singularmente, en Marruecos también existen especies reófilas del género Luciobarbus de pequeño tamaño y que presentan diferentes caracteres morfológicos y distintos requerimientos de hábitat. Estas especies reófilas han sido tradicionalmente asignadas a Luciobarbus nasus (Günther, 1874) y L. magniatlantis (Pellegrin, 1919) aunque algunos autores consideran a L. magniatlantis como un sinónimo de L. nasus. Esta falta de consenso en la taxonomía de los barbos reófilos está limitada por los escasos estudios poblacionales realizados que no abarcan la totalidad del área de distribución de estos barbos. Nosotros, usando datos moleculares, morfométricos y osteológicos, estudiamos las poblaciones de los barbos reófilos de tres cuencas hidrográficas, en las cuales están actualmente presentes: Tensift, Moulouya y Oum er Rbia. Nuestros resultados claramente identifican a los barbos reófilos de cada una de estas cuencas como diferentes especies. La especie L. magniatlantis es una especie bien definida y endémica de la cuenca del Tensift. En contraste, las poblaciones analizadas de las cuencas del Moulouya y Oum er Rbia no pudieron ser asignadas a ninguna especie previamente descrita. Consecuentemente, nosotros describimos dos nuevas especies de Luciobarbus en las cuencas del Moulouya y del Oum er Rbia.Peer Reviewe

Pathotypic diversity of Rhynchosporium secalis (Oudem) in Tunisia

Scald, caused by Rhynchosporium secalis (Oudem), is an important disease of barley in Tunisia particularly in northern, northwestern and central parts of the country where the climate is usually cold and wet during most of the barley growing season. Pathogenic variability of the barley scald pathogen in Tunisia was determined by testing the pathogenicity of 100 isolates from 5 different regions on 19 host differentials. Pathotypic diversity was high, with 93 R. secalis pathotypes identified on two differential sets (one comprising 9 and the other 10 barley lines) containing known resistance genes. A few pathotypes comprised 2% of the isolates; however, the majorities were represented by a single isolate. None of the differential lines was resistant to all isolates. The differential cultivar “Astrix” was the least compatible with the scald pathotypes followed by the differential cultivars “Atlas” and “Abyssinia”. Compatibility of the pathotypes on “Rihane” (69%) was close to that on “Osiris” (73%) and “La Mesita” (61%). None of the pathotypes was found in all the five regions of Tunisia surveyed. Some pathotypes were specific to a single region while others were found in several regions. The incidence of pathotypes varied considerably among regions, with region 3 (northwestern Tunisia) comprising the largest number of pathotypes. Virulent pathotypes were recovered in all regions but more pathotypic variability (44%) was observed in the semi-arid region 3. Differential cultivars allowed classification of R. secalis in four virulence groups. Canonical discriminant analysis showed no apparent association between virulence and geographical origin of the populations. Pathogenic variability in R. secalis in Tunisia was found not to be associated with geographical region, hence, the necessity for deployment of different resistance sources in major barley growing areas.Key words: Rhynchosporium secalis, barley, virulence groups, pathotypic variation