Continuous Cauchy wavelet transform of XAFS spectra.

The continuous Cauchy wavelet transform (CCWT) is applied to the analysis of XAFS spectra. Thanks to that method, XANES and EXAFS signals can be visualized in threedimension: the wavevector (k), the interatomic distance uncorrected for phase-shifts (R') and the CCWT modulus (corresponding to the continuous decomposition of the amplitude terms). Applied to EXAFS spectra, the CCWT analysis provides straightforward qualitative information related to the k-range of each “R'-EXAFS” contribution. Such information is particularly useful to perform next nearest-neighbors identification, despite the presence of spectral artifacts such as multiple-scattering features, multi-electronic excitations or noise. When applied to XANES spectra, the CCWT analysis helps highly to measure the “spectral limit” between XANES and EXAFS regions, as well as the energy range required to model properly next-nearest neighbors. To further illustrate the potential of CCWT analyses applied to XAFS spectra, we present examples related to: (1) a XANES spectrum collected at the Ti K-edge for titanite (CaTiSiO5); (2) an experimental Au LIII-edge EXAFS spectrum for gold sorbed on goethite (FeO(OH))

Continuous Cauchy wavelet transform analyses of EXAFS spectra: A qualitative approach.

To better understand the extended x-ray absorption fine structure (EXAFS) spectroscopic information obtained for complex materials such as those encountered in Earth sciences, we propose to use the Continuous Cauchy Wavelet Transform (CCWT). Thanks to this method, the EXAFS spectra can be visualized in three-dimension: the wavevector (k), the interatomic distance uncorrected for phase-shifts (R') and the CCWT modulus (corresponding to the continuous decomposition of the EXAFS amplitude terms). Consequently, more straightforward qualitative interpretations of EXAFS spectra can be performed, even when spectral artifacts are present, such as multiple-scattering features, multi-electronic excitations or noise. More particularly, this method provides important information concerning the krange of each EXAFS contribution, such as next nearest-neighbors identification. To illustrate the potential of CCWT analyses applied to EXAFS spectra, we present first the experimental and theoretical spectra obtained for well-crystallized minerals, thorite and zircon, at the Th LIII-, and Zr K-edges, respectively. Then, we present the CCWT analyses of EXAFS spectra collected for amorphous materials of geochemical and environmental interests, including a sodium trisilicate glass and an aqueous chloride solution, at the Mo K-, and Au LIII-edges, respectively

Growth rings in tropical trees : role of functional traits, environment, and phylogeny

Acknowledgments Financial support of the Centre National de la Recherche Scientifique (USR 3330), France, and from the Rufford Small Grants Foundation (UK) is acknowledged. We thank the private farmers and coffee plantation companies of Kodagu for providing permissions and logistical support for this project. We are grateful to N. Barathan for assistance with slide preparation and data entry, S. Aravajy for botanical assistance, S. Prasad and G. Orukaimoni for technical inputs, and A. Prathap, S. Shiva, B. Saravana, and P. Shiva for field assistance. The corresponding editor and three anonymous reviewers provided insightful comments that improved the manuscript.Peer reviewedPostprin

Contribution à l'étude des communautés d'adventices des culture du secteur phytogéographique oranais (Nord-ouest algérien) : aspects botanique, agronomique et phyto-écologique

International audienceL'étude de l'enherbement des agrosystèmes d'Oranie, dans le Nord-Ouest de l'Algérie, s'appuie sur 547 relevés floristiques réalisés dans les différentes cultures de cette région, pour décrire les caractères d'ensemble de la flore adventice ainsi que les attributs botaniques, phytogéographiques, biologiques et éthologiques des 425 espèces recensées. Nous analysons l'importance agronomique des espèces à partir de leur fréquence relative et de leur recouvrement moyen. La projection des espèces sur un diagramme d'infestation a permis de différencier 6 groupes d'espèces. L'étude phyto-écologique des relations entre espèces et variables de milieu par l'analyse non-symétrique des correspondances – NSC, sous contrainte environnementale indique que la principale source de variation floristique au niveau des différents terroirs d'Oranie est liée aux systèmes de cultures

L’éducation à la sexualité: conceptions d’enseignants et futurs enseignants de douze pays

School Sex Education is nowadays an important public health issue as it concerns not only youth AIDS prevention (and other sexually transmitted infections – STI) and adolescent pregnancy prevention but also interpersonal relationships and psychosocial issues. Therefore school sex education contributes to promote better citizenship. The European FP6 Biohead-Citizen research project aims to understand how biology, health and environmental education can contribute to improving citizenship. It analyses the social representations and practices of teachers in several countries, focusing on their differences and associating them to controlled parameters (e.g. social context, religion, gender). In this communication we analyse data concerning teachers’ and future teachers’ conceptions on the topic of sex education derived from a questionnaire that was constructed and tested during the first year of the project. The questionnaire was completed by 5189 teachers and future teachers from 12 countries. We used statistical multivariate analyses, a method that has become standard for investigating complex data derived from many individuals that needs to be analysed according to many variables (here we have used the responses to the questions as variables). The results show that the factors that correlate most closely with the teachers’ and future teachers’ conceptions are religion, the level of belief in God and the level of religious practices. It was also found that the level of teaching (primary versus secondary school) is also correlated with different conceptions on sex education. Detailed results will be presented and discussed.LIBEC/CIFPEC - unidade de investigação 16/644 da FCT.European project FP6 Biohead-Citizen CIT2-CT-2004-506015

Health education: analysis of teachers’ and future teachers’ conceptions from 16 countries (Europe, Africa and Middle East)

School is an important setting for health education and health promotion, and it has been recognised that teachers’ conceptions play a crucial role for the effective implementation of school health education. With the European FP6 Biohead-Citizen project on “Biology Health and Environmental education for better citizenship” we analysed the potential differences between several countries by associating teachers’ and future teachers’ conceptions to controlled parameters, such as level of training, religion, political view. A questionnaire was constructed during the first year of the project, and following a pilot test, the final questionnaire was applied to 6379 teachers and future teachers. We then used well-suited statistical multivariate methods to investigate complex data featuring the conceptions of many individuals, according to many topics. We show that a prominent source of variation in teachers’ conceptions is related to countries, and further suggest that there are differences in two kinds of conceptions: a) individual health responsibilities and abilities; b) social policies. Religion, academic level or training had also an impact in teachers’ conceptions of health education. Another important feature is the gap between what teachers and future teachers say about their own health and what they say it should be taught in school. Results are then discussed.LIBEC/CIFPEC - unidade de investigação 16/644 da FCT.European project FP6 Biohead-Citizen CIT2-CT-2004-506015

L’éducation à la santé et à la sexualité: conceptions d’enseignants et futurs enseignants de douze pays

Ce travail analyse les réponses d’enseignants et futurs enseignants de 12 pays, choisis à cause de leurs contextes socio-économiques et culturels contrastés, à des questions ayant trait à l’Éducation à la Santé et à la Sexualité. Notre objectif est d'identifier en quoi ces conceptions varient, d'un pays à un autre, mais aussi au sein de chaque pays. Plusieurs analyses en composantes principales sont menées sur l’ensemble des variables « Éducation à la Santé et à la Sexualité » ainsi que sur l’ensemble des variables « Pratiques d’enseignement ». C'est surtout en fonction de représentations sociales et de valeurs que se différencient les réponses des personnes interrogées. Ce sont les valeurs et représentations relatives à l'Éducation à la Sexualité qui différencient le plus les pays, avec des positions plus traditionnelles, opposées à l'introduction de thèmes importants de cette éducation, dans les pays non européens. De plus, les conceptions relatives aux pratiques d'enseignement diffèrent significativement d'un pays à un autre, ainsi que d'une catégorie d'échantillon à une autre.LIBEC/CIFPEC - unidade de investigação 16/644 da FCT. .European project FP6 Biohead-Citizen CIT2-CT-2004-50601