Dichroic Masers due to Radiation Anisotropy and the Influence of the Hanle Effect on the Circumstellar SiO Polarization

The theory of the generation and transfer of polarized radiation, mainly developed for interpreting solar spectropolarimetric observations, allows to reconsider, in a more rigorous and elegant way, a physical mechanism that has been suggested some years ago to interpret the high degree of polarization often observed in astronomical masers. This mechanism, for which the name of 'dichroic maser' is proposed, can operate when a low density molecular cloud is illuminated by an anisotropic source of radiation (like for instance a nearby star). Here we investigate completely unsaturated masers and show that selective stimulated emission processes are capable of producing highly polarized maser radiation in a non-magnetic environment. The polarization of the maser radiation is linear and is directed tangentially to a ring equidistant to the central star. We show that the Hanle effect due to the presence of a magnetic field can produce a rotation (from the tangential direction) of the polarization by more that 45 degrees for some selected combinations of the strength, inclination and azimuth of the magnetic field vector. However, these very same conditions produce a drastic inhibition of the maser effect. The rotations of about 90 degrees observed in SiO masers in the evolved stars TX Cam by Kemball & Diamond (1997) and IRC+10011 by Desmurs et al (2000) may then be explainedby a local modification of the anisotropy of the radiation field, being transformed from mainly radial to mainly tangential.Comment: Accepted for publication on Ap

The Learning by the Creation of Event: Theatrical Approach, Interactive, Co-Operative and Individualizing Pedagogy of Project (The Case of the Artistic Carnival of the PPP in the ISET of Gabès)

Abstract In the framework of the valorization of the pedagogy of project via the development of the learning by the event, we organized a day dedicated to the fair of the Professional Project personalized by a theatrical production of outputs animated by the students accompanied. This experience based on the adoption of the active pedagogy generated interesting results in terms of satisfaction, self-confidence, positive emotions, exceeding itself, vitality, pleasure and self-realization. An event, which constitutes a clinical case of active pedagogy, worthy of the reinvestments in the future. This document will attempt to synthesize this experience in describing, student the inputs to the catalysis of the participation and by analyzing the main results generated by this event

Investigation of genetic variability related to the in vitro floral hermaphrodism induction in Date palm (Phoenix dactylifera L.)

This paper reports on a molecular analysis study conducted on Date palm flowers from the Deglet Nour cultivar to investigate putative genetic variability related to the in vitro floral hermaphrodism induction. Natural male and female as well as hermaphrodite ones that were produced in vitro through the hormonal treatment of female flowers were submitted to ISSR-PCR analysis. Microsatellite based amplification (ISSR) was applied on genomic DNA from inflorescences taken at different periods of hormonal treatment corresponding to the various deviation stages to search for putative variations that may have occurred on the initial genome due to the application of plant growth regulators. Several amplification bands were purified, cloned, and sequenced. The results revealed that hormonal treatment entailed no detectable genetic variation in the treated Date palm flowers. Two of the selected and ISSR-PCR amplified DNA fragments showed however, possible links with flowering regulation. The findings indicate that these sequences are potential candidate gene markers that may enhance our understanding of flower development and sex identification in this species.Key words: Date palm, female inflorescences, hermaphrodite flowers, in vitro culture, ISSR, sex identification

Quasi-molecular lines in Lyman wings of cool DA white dwarfs; Application to FUSE observations of G231-40

We present new theoretical calculations of the total line profiles of Lyman alpha and Lyman beta which include perturbations by both neutral hydrogen AND protons and all possible quasi-molecular states of H_2 and H_2^+. They are used to improve theoretical modeling of synthetic spectra for cool DA white dwarfs. We compare them with FUSE observation of G231-40. The appearance of the line wings between Lyman alpha and Lyman beta is shown to be sensitive to the relative abundance of hydrogen ions and neutral atoms, and thereby to provide a temperature diagnostic for stellar atmospheres and laboratory plasmas.Comment: 6 pages, 4 figures, accepted for publication in Astronomy and Astrophysic

Enhanced Graph Rewriting Systems for Complex Software Domain

International audienceMethodologies for correct by construction reconfigurations can efficiently solve consistency issues in dynamic software architecture. Graph-based models are appropriate for designing such architectures and methods. At the same time, they may be unfit to characterize a system from a non functional perspective. This stems from efficiency and applicability limitations in handling time-varying characteristics and their related dependencies. In order to lift these restrictions, an extension to graph rewriting systems is proposed herein. The suitability of this approach, as well as the restraints of currently available ones, are illustrated, analysed and experimentally evaluated with reference to a concrete example. This investigation demonstrates that the conceived solution can: (i) express any kind of algebraic dependencies between evolving requirements and properties; (ii) significantly ameliorate the efficiency and scalability of system modifications with respect to classic methodologies; (iii) provide an efficient access to attribute values; (iv) be fruitfully exploited in software management systems; (v) guarantee theoretical properties of a grammar, like its termination

A first investigation for reducing e-learning environment complexity by Multiscale

International audienceNo abstrac

Graphical Representations Of Message Exchanges Into Web Service-based Applications

Web service-based application is an architectural style, where a collection of Web services communicate to each other to execute processes. With the popularity increase of Web service-based applications and since messages exchanged inside of this applications can be complex, we need tools to simplify the understanding of interrelationship among Web services. This work present a description of a graphical representation of Web service-based applications and the mechanisms inserted among Web service requesters and providers to catch information to represent an application. The major contribution of this paper is to discus and use HTTP and SOAP information to show a graphical representation similar to a UML sequence diagram of Web service-based applications.1 ISAS367370Web Services Architecture (2004) W3C Working Group Note, , http://www.w3.org/TR/2004/NOTE-ws-arch-20040211, Booth, D, Haas, H, McCabe, F, Newcomer, E, Champion, M, Ferris, C, Orchard, D, Eds, February 11, Retrieved March 22, 2007, fromBox, D., and Curbera, F. (Eds.) (2004, August 10). Web Services Addressing (WS-Addressing). Web Services Addressing (WS-Addressing), W3C Member Submission, Retrieved July 30, 2007, from http://www.w3.org/ Submission/ws-addressing/Box, D., Ehnebuske, D., Kakivaya, G., Layman, A., Mendelsohn, N., Nielsen, H., Thatte, S., Winer, D., (Eds.) (2000, May 08) Simple Object Access Protocol (SOAP) 1.1. W3C Note, Retrieved July 30, 2007, from http://www.w3.org/TR/2000/NOTE-SOAP-20000508/(2006) Web Services Addressing 1.0 - Core, , http://www.w3.org/TR/ws-addr-core, Gudgin, M, Hadley, M, Rogers, T, Eds, 9 May, Retrieved March 25, 2007, fromMahmoud, Q.H., (2005) Service-Oriented Architecture (SOA) and Web Services: The Road to Enterprise Application Integration (EAI), , http://java.sun.com/developer/technicalArticles/WebServices/soa, April, Retrieved November 21, 2007, fromRud, D., Schmietendorf, A., Dumke, R., Performance Modeling of WS-BPEL-Based Web Service Compositions (2006) IEEE Services Computing Workshops (SCW'06), pp. 140-147(2007) Web Services Business Process Execution Language v2.0, , http://docs.oasis-open.org/wsbpel/2.0/0S/wsbpel-v2.0-OS.html, April 11, Retrieved November 20, 2007, fro