Chemistry and structure of BaTiO3 ultra-thin films grown by different O2 plasma power

International audienceWe present a study of the chemical and atomic properties of 5 nm TiO2-terminated BaTiO3 (001) epitaxialfilms on Nb-doped SrTiO3, as a function of the atomic oxygen plasma power for film growth. Lowerplasma power produces non-stoichiometric films with oxygen vacancies and Ti3+ ions. The larger Ti3+ion radius and the in-plane clamping gives rise to an increase in the out-of-plane lattice parameter.XPS measures the Ti3+ concentration and the concomitant increase in dissociative water uptake in thefilm, giving rise to on-top OH adsorption on surface Ti, proton adsorption on surface oxygen, and a nearsurface Ba-OH environment

Les rhyolites à topaze de la région de San Luis Potosi (Mexique) : caractéristiques des laves et conditions de croissance des topazes

Au Mexique, les rhyolites à topaze se rencontrent principalement dans la région de San Luis Potosi (Etats de San Luis Potosi et de Guanajuato). Ces rhyolites se présentent sous la forme de dômes mis en place lors d’une tectonique en extension d’âge tertiaire. Trois dômes du champv olcanique de San Luis Potosi ont été retenus pour cette étude en fonction de la couleur, de la forme et de la taille des topazes qu’ils contiennent afin de déterminer les caractéristiques des laves et les conditions de croissance des topazes. Ces rhyolites, riches en silice et alcalins, sont méta-alumineuses à légèrement hyper-alumineuses. Elles sont enrichies en fluor et en éléments incompatibles comme Rb, Cs, Ta, U et Th et appauvries en Ba, Sr, Ca, Mg, Ti et Ni. De ce fait elles apparaissent très comparables aux rhyolites à topaze de l’ouest des Etats-Unis. Le Cerro El Gato contient des topazes soit de couleur ambre, soit incolores qui ont cristallisé dans des géodes et des fractures. En prenant en compte le milieu de croissance, la morphologie, la composition chimique et les caractéristiques RPE de ces différents cristaux, il est possible de proposer un modèle de cristallisation et d’expliquer les différences de couleur observées. Ainsi, les topazes incolores du Cerro El Gato ont cristallisé à une température supérieure à 500oC (absence de centres colorés) et à partir de fluides enrichis en éléments lessivés de la lave, alors que les topazes de couleur ambre ont cristallisé à une température inférieure à 500oC (présence de centres colorés) et à partir d’un fluide plus riche en éléments volatils (As). Les topazes du Cerro el Lobo ont des caractéristiques intermédiaires entre celles des topazes incolores et des topazes ambres du Cerro El Gato

Leptoquark Single and Pair production at LHC with CalcHEP/CompHEP in the complete model

We study combined leptoquark (LQ) single and pair production at LHC at the level of detector simulation. A set of kinematical cuts has been worked out to maximize significance for combined signal events. It was shown that combination of signatures from LQ single and pair production not only significantly increases the LHC reach, but also allows us to give the correct signal interpretation. In particular, it was found that the LHC has potential to discover LQ with a mass up to 1.2 TeV and 1.5 TeV for the case of scalar and vector LQ, respectively, and LQ single production contributes 30-50% to the total signal rate for LQ-l-q coupling, taken equal to the electromagnetic coupling. This work is based on implementation of the most general form of scalar and vector LQ interactions with quarks and gluons into CalcHEP/CompHEP packages. This implementation, which authors made publicly available, was one the most important aspects of the study.Comment: LaTeX, 27 pages, 15 figure

Basic Module Theory over Non-Commutative Rings with Computational Aspects of Operator Algebras

The present text surveys some relevant situations and results where basic Module Theory interacts with computational aspects of operator algebras. We tried to keep a balance between constructive and algebraic aspects.Comment: To appear in the Proceedings of the AADIOS 2012 conference, to be published in Lecture Notes in Computer Scienc

Phenotypic Characterization According to The Feather Color of Indigenous Muscovy Ducks Bred in The Back Yard in Brazzaville, The Congo

Abstract.  In Congo, waterfowl genetic resources are constituted by native population of Muscovy ducks that play an important role in food security. The present study aimed to identify and to characterize strains bred in the back yard in the households in Brazzaville. A sample of 154 households drawn over seven districts of Brazzaville was enrolled in the survey. Adults ducks found in the households were identified, pictured by a key of determination and then compared by using the multi resolution analysis image method. The survey recorded 13 strains in which four were considered as newly since they have never been reported elsewhere. These strains received temporally the name of the districts where they have been identified for the first time Makelékélé 1 (0.34%, n=6), Makélékélé 2 (0.11%, n =2), Poto poto 1  (0.28%, n=5) and in Poto poto 2 (0.11%, n=2). Finally, the survey reported nine classical  strains such as  black plumage, duclair, white, tortora, sepia, chocolate, lavender, grey and canizie. The apparent wide variation in plumage colors is an indication that the duck populations have not been ‘purified’ through selective breeding. In the context of the valorization of poultry biodiversity, this work represents a step toward a better knowledge of the production abilities of local ducks breeds in Congo. Key words: Muscovy ducks, color feather, strains, Congo. Abstrak.  Sumber daya genetik unggas air di Kongo mencakup populasi itik lokal yang memegang peranan penting dalam ketahanan pangan. Penelitian ini bertujuan mengidentifikasi dan menggolongkan jenis itik yang dipelihara di pekarangan rumah di Brazzaville. Sampel penelitian menggunakan 154 responden rumah tangga yang tersebar di 7 wilayah Brazzaville. Itik dewasa diidentifikasi dari pekarangan, dan dibandingkan dengan metode Analisis Multi Resolusi. Survey mencatat 13 jenis peranakan, 4 diantaranya dianggap baru karena belum pernah dilaporkan di studi manapun. Jenis ini sementara dinamai sesuai distrik tempatnya pertama ditemukan, yaitu Makelékélé 1 (0,34%, n=6), Makélékélé 2 (0,11%, n =2), Poto poto 1  (0,28%, n=5) dan di Poto poto 2 (0,11%, n=2). Berdasarkan survei didapatkan sembilan jenis klasik yaitu bulu hitam, duclair, putih, tortora, sepia, coklat, lavender, abu-abu dan canizie. Banyaknya ragam warna bulu adalah indikasi bahwa populasi itik belum “dimurnikan” melalui seleksi. Dalam konteks penetapan nilai keanekaragaman hayati unggas, penelitian ini mewakili sebuah langkah menuju pengetahuan yang mendalam akan kemampuan produksi itik yang berkembang di Kongo. Kata kunci: itik Muscovy, warna bulu, strain, Kong

Role of livestock in human nutrition and health for poverty reduction in developing countries

Livestock keeping is critical for many of the poor in the developing world, often contributing to multiple livelihood objectives and offering pathways out of poverty. Livestock keeping also affects an indispensable asset of the poor, their human capital, through its impact on their own nutrition and health. This paper outlines the linkages between livestock keeping and the physical well-being of the poor, and examines a number of commonly held beliefs that misrepresent livestock development issues related to these linkages. These beliefs limit the scope of intervention programs to promote livestock and limit their potential contribution to poverty reduction. Recognition of the complexity of the role livestock play in household decision-making and of the opportunities foregone due to these misconceptions can enhance the ability of livestock to contribute to human well-being in the developing world

Estimation of solar prominence magnetic fields based on the reconstructed 3D trajectories of prominence knots

We present an estimation of the lower limits of local magnetic fields in quiescent, activated, and active (surges) promineces, based on reconstructed 3-dimensional (3D) trajectories of individual prominence knots. The 3D trajectories, velocities, tangential and centripetal accelerations of the knots were reconstructed using observational data collected with a single ground-based telescope equipped with a Multi-channel Subtractive Double Pass imaging spectrograph. Lower limits of magnetic fields channeling observed plasma flows were estimated under assumption of the equipartition principle. Assuming approximate electron densities of the plasma n_e = 5*10^{11} cm^{-3} in surges and n_e = 5*10^{10} cm^{-3} in quiescent/activated prominences, we found that the magnetic fields channeling two observed surges range from 16 to 40 Gauss, while in quiescent and activated prominences they were less than 10 Gauss. Our results are consistent with previous detections of weak local magnetic fields in the solar prominences.Comment: 14 pages, 12 figures, 1 tabl

Beyond intrinsic and extrinsic motivation: A meta-analysis on self-determination theory’s multidimensional conceptualization of work motivation

This meta-analysis aims to shed light on the added value of the complex multidimensional view on motivation of Self-determination theory (SDT). We assess the unique and incremental validity of each of SDT’s types of motivation in predicting organizational behavior, and examine SDT’s core proposition that increasing self-determined types of motivation should have increasingly positive outcomes. Meta-analytic findings (124 samples) support SDT, but also adds precision to its predictions: Intrinsic motivation is the most important type of motivation for employee well-being, attitudes and behavior, yet identified regulation is more powerful in predicting performance and organizational citizenship behavior. Furthermore, introjection has both positive and negative consequences, while external regulation has limited associations with employee behavior and has well-being costs. Amotivation only has negative consequences. We address conceptual and methodological implications arising from this research and exemplify how these results may inform and clarify lingering issues in the literature on employee motivation