Mesure de la permittivité du PbZrTiO3 dans les radiofréquences par une méthode en réflexion

National audienceDes couches minces de PbZr0,34Ti0,66O3 ont été réalisées sur substrat de verre par voie chimique et dépôt par centrifugation. Afin de déterminer la permittivité effective de l'échantillon ferroélectrique dans la gamme des hyperfréquences (1-5 GHz), nous utilisons une méthode de mesure en réflexion sur une structure coplanaire. Appuyé sur une succession de transformations conformes, un modèle d'analyse statique de la structure est utilisé permettant de remonter à la permittivité relative du ferroélectrique

Variations in adolescents’ motivational characteristics across gender and physical activity patterns: A latent class analysis approach

Abstract Background Neglecting to take account of the underlying context or type of physical activity (PA) that underpins overall involvement has resulted in a limited understanding of adolescents’ PA participation. The purpose of the present research was to identify male and female adolescents’ leisure time PA patterns and examine whether psychological processes derived from self-determination theory differ as a function of the pattern of PA undertaken. Methods Nine hundred ninety-five students (61.2% females, 38.8% males; M age = 13.72 years, SD = 1.25) from eight secondary schools in Dublin, Ireland completed a physical activity recall 7 day diary and measures of intrinsic motivation, competence, relatedness, autonomy and autonomy support. Based on the diary five binary indicators of physical activity were derived reflecting recommended levels of MVPA on a minimum of 3 days, at least three sessions of non-organized physical activity (e.g. jog), team sport, individual sport, and organized non-sport physical activity (e.g. dance). Latent class analysis was used to identify subgroups of adolescents that engaged in similar patterns of physical activity. Profiles of physical activity participation were subsequently compared on motivational characteristics using Kruskal-Wallis tests. Results Latent class analysis revealed six distinct classes for girls (Organized Run/Swim & Dance/Gym; Organized Dance; Leisure Active Team Sport; Active Individual Sport; Walk/Run/Outdoor games; Non-Participation) and five for boys (Leisure Active Gym; Leisure Active Individual Sport; Active Team Sport; Active Mixed Type; Non-Participation). Significant differences were found between the classes. Girls characterized by participation in team or individual sport, and boys represented by team sport participation demonstrated significantly higher self-determined motivational characteristics relative to other profiles of physical activity. Conclusion This research offers a nuanced insight into the underlying type of activities that constitute overall patterns of PA among adolescent boys and girls and further reveals that psychological processes vary dependent on the profile of physical activity undertaken. The findings may be useful for informing interventions aimed at promoting physical activity among young people

A Solve-RD ClinVar-based reanalysis of 1522 index cases from ERN-ITHACA reveals common pitfalls and misinterpretations in exome sequencing

Purpose Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the “ClinVar low-hanging fruit” reanalysis, reasons for the failure of previous analyses, and lessons learned. Methods Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted. Results We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency). Conclusion The “ClinVar low-hanging fruit” analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock

Les pokhari dans la plaine du Népal : des étangs à usages multiples ou passant à la pisciculture exclusive dans le contexte tendu des transformations territoriales du Téraï oriental

Resource management is one of the major contemporary challenges for rural societies. In the Eastern Terai plain (Nepal), with high population densities (larger than 500 inhabitants/ km²), the territorial restructurings force local population to deal with high pressures on land and on water. In particular, they lead to deep modifications in the practices of pokhari users. These ponds have various sizes (from 0.01 to 6 hectares or more) are defined as multi-purpose ecosystems. According to their tenure, public or private, a pokhari is either collectively managed by Tharu or Madhesi village communities, which have their origin in the plain, or are administrated individually, by Pahari independent harvesters, who favour personal initiatives. Despite the fact that they are ubiquitous in the Saptari and Sunsari districts, which are the two fields of study of the present Ph.D. work, pokhari have become the target of government policies only since the 90’s and these policies have aimed at increasing the Teraï plain economic productivity by developing intensive fish farming in pokhari and by auctioning licenses for a private management of the pokhari. In their practices, local populations are confronted to new stakes of individualization and of privatization: these processes strengthen social and economical inequalities between powerful landowners on the one side, and on the other side lower-caste populations of Terai which defend multi-purpose uses of the pokhari. The combination of the typology, established in the present Ph.D. work, of 232 ponds located in the Saptari and Sunsari districts, and of an analysis of the time-and-space evolution of the surfaces of the water bodies, shows that the recent productivist logic defended by the Nepalese State do not yield a uniform modification of the uses. Yet, some of the Madhesi communities mobilize against additional social exclusions, thereby reconsidering the power balance in the governance of the Terai plain ponds.La gestion des ressources représente un des défis contemporains majeurs pour les sociétés rurales. Dans la plaine du Téraï oriental (Népal), qui renferme des densités de population élevées (plus de 500 hab./ km²), des restructurations territoriales amènent les communautés villageoises à faire face à de fortes tensions foncières et à des pressions croissantes sur l’eau. Elles amènent notamment à des changements profonds dans les pratiques en termes d’utilisation et gestion des pokhari. Ces plans d’eau, de tailles diverses (de 0,01 à 6 hectares ou plus), sont définis comme des écosociosystèmes multi-usages. De tenure publique ou privée, les pokhari sont gérés collectivement par des communautés villageoises Tharu ou Madhesi, des populations originaires de la plaine, ou individuellement et plutôt par des exploitants-indépendants qui, au travers de leurs initiatives personnelles, participent au processus d’individualisation dans la gestion des ressources. Alors qu’ils sont omniprésents dans les districts de Saptari et de Sunsari, nos deux terrains d’étude, ce n’est qu’à partir des années 1990 que les pokhari deviennent la cible de politiques publiques visant à augmenter la productivité de la plaine par le développement de la pisciculture intensive et par la mise aux enchères d’autorisations privatives de leur utilisation et gestion. Cette thèse de Doctorat combine une approche qualitative et quantitative : une typologie est construite pour l’analyse des caractéristiques de 232 plans d’eau localisés à Saptari et à Sunsari ; elle est combinée à une analyse spatio-temporelle de l’évolution des surfaces en eau des pokhari, et met en lien le développement des logiques productivistes gouvernementales avec l’intensification du productivisme dans l’utilisation des plans d’eau. Pour autant, face aux interdictions d’usage de plans d’eau anciennement collectifs, des communautés interrogées dans la plaine revendiquent leur territoire de l’eau et l’appartenance identitaire qui s’y rattache. La lutte contre des formes nouvelles d’exclusion sociale permet de reconsidérer les rapports de pouvoir dans la gouvernance des plans d’eau de la plaine

Pokhari of the Nepalese lowland region : defining them as multi-purpose water bodies and changing ponds that are used for fish farming in a territorials transformations tense context of the eastern Terai

La gestion des ressources représente un des défis contemporains majeurs pour les sociétés rurales. Dans la plaine du Téraï oriental (Népal), qui renferme des densités de population élevées (plus de 500 hab./ km²), des restructurations territoriales amènent les populations locales à faire face à de fortes pressions foncières et sur l’eau. Elles amènent notamment à des changements profonds dans les pratiques des usagers de pokhari. Ces plans d’eau, de tailles diverses (de 0,01 à 6 hectares ou plus), sont définis comme des écosystèmes multi-usages. De tenure publique ou privée, les pokhari sont gérés collectivement par des communautés villageoises Tharu ou Madhesi, des populations originaires de la plaine, ou individuellement et plutôt par des exploitants-indépendants Pahari qui privilégient les initiatives personnelles. Alors qu’ils sont omniprésents dans les districts de Saptari et de Sunsari, nos deux terrains d’étude, ce n’est qu’à partir des années 1990 que les pokhari deviennent la cible de politiques publiques visant à augmenter la productivité économique de la plaine par le développement de la pisciculture intensive dans les pokhari et par la mise aux enchères d’autorisations privatives de leur gestion. Les populations locales doivent faire face à de nouveaux enjeux d’individualisation et de privatisation dans les pratiques : ces processus renforcent les inégalités sociales et économiques entre de puissants propriétaires fonciers et des populations de basses-castes du Téraï qui défendent la pratique multi-usages des pokhari. D’après une typologie, établie dans ce travail de thèse, de 232 plans d’eau localisés à Saptari et à Sunsari, combinée à une analyse spatio-temporelle de l’évolution des surfaces en eau des pokharii, les récentes logiques productivistes défendues par l’État népalais engendrent diverses modifications des pratiques, discutées dans ce travail. Pourtant, face aux interdictions d’usage de plans d’eau anciennement collectifs, certaines communautés Madhesi se mobilisent contre de nouvelles exclusions sociales, reconsidérant les rapports de force dans la gouvernance des plans d’eau de la plaine.Resource management is one of the major contemporary challenges for rural societies. In the Eastern Terai plain (Nepal), with high population densities (larger than 500 inhabitants/ km²), the territorial restructurings force local population to deal with high pressures on land and on water. In particular, they lead to deep modifications in the practices of pokhari users. These ponds have various sizes (from 0.01 to 6 hectares or more) are defined as multi-purpose ecosystems. According to their tenure, public or private, a pokhari is either collectively managed by Tharu or Madhesi village communities, which have their origin in the plain, or are administrated individually, by Pahari independent harvesters, who favour personal initiatives. Despite the fact that they are ubiquitous in the Saptari and Sunsari districts, which are the two fields of study of the present Ph.D. work, pokhari have become the target of government policies only since the 90’s and these policies have aimed at increasing the Teraï plain economic productivity by developing intensive fish farming in pokhari and by auctioning licenses for a private management of the pokhari. In their practices, local populations are confronted to new stakes of individualization and of privatization: these processes strengthen social and economical inequalities between powerful landowners on the one side, and on the other side lower-caste populations of Terai which defend multi-purpose uses of the pokhari. The combination of the typology, established in the present Ph.D. work, of 232 ponds located in the Saptari and Sunsari districts, and of an analysis of the time-and-space evolution of the surfaces of the water bodies, shows that the recent productivist logic defended by the Nepalese State do not yield a uniform modification of the uses. Yet, some of the Madhesi communities mobilize against additional social exclusions, thereby reconsidering the power balance in the governance of the Terai plain ponds

La place des réseaux d’entraide interpersonnels Nord-Sud dans le processus de reconstruction postcatastrophe : l’exemple du séisme de 2015 au Népal

International audienceIn the days following the Nepal earthquake of spring 2015, faced with a lack of effective government action, the villagers reacted by turning to the many relationships they had made with Westerners they had met walking on the slopes of their mountains. These contacts led to proposals of assistance. This aid, which here we call “informal” because it is based on interpersonal relationships, is multifaceted, since it involves many ways of intervention. This study is concerned with the origins, nature, and extent of these instances of interpersonal aid, which enabled several villages to recover after the earthquakes.ans les jours qui suivirent les séismes qui frappèrent le Népal au printemps 2015, face à l’absence d’actions gouvernementales efficaces, les villageois ont réagi en faisant appel aux nombreuses relations nouées avec des Occidentaux aux hasards des rencontres faites en arpentant les pentes de leurs montagnes. Ces contacts ont débouché sur des propositions d’assistance. Cette aide, que nous qualifions d’informelle car née de relations interpersonnelles, est polymorphe puisqu’elle a pris toutes les formes possibles d’intervention. L’étude s’intéresse aux origines, à la nature et à l’étendue de ces aides interpersonnelles, qui ont permis à plusieurs villages de se relever après les secousses

An Efficient Method to Study the Tradeoff Between Power Amplifier Efficiency and Digital Predistortion Complexity

International audienceThis letter proposes a method to study the tradeoff between the power amplifier (PA) power efficiency and the corresponding digital predistortion (DPD) model complexity needed for its linearization. The linearization performance estimated with the adjacent channel power ratio (ACPR) is treated as a control variable. In order to study at different PA operating points (OPs), an algorithm is proposed to trace approximate Pareto fronts of the ACPR versus the DPD model number of coefficients. Crest factor reduction is applied when the backoff of the OP is less than the peak-to-average power ratio (PAPR) of the long-term evolution (LTE) signal. Experimental results on a PA with an LTE signal give interesting insights on the relationship between DPD complexity and PA power efficiency

A Joint Crest Factor Reduction and Digital Predistortion for Power Amplifiers Linearization Based on Clipping-and-Bank-Filtering

International audienceThe power efficiency and the linearity of a power amplifier (PA) depend on its operating point. A high efficiency generally corresponds to poor linearity. To optimize the efficiency/linearity trade-off, crest factor reduction (CFR) techniques are classically implemented along with digital predistortion (DPD) to control the PA operating point. Joint CFR/DPD can be realized with a single model so that the running complexity of the CFR is negligible. This paper fully explores the clipping-and-bank-filtering (CABF) method for joint CFR/DPD and extends it to the multi-carrier case with validation on experimental results. Compared with conventional approaches, it provides either better linearization performance or lower complexity at the same PA operating point. The study is completed with a discussion on the choice of windows in the filter bank. The proposed CABF-based joint CFR/DPD model is then experimentally evaluated on a test bench with two PAs using single-carrier and 2-carrier 20~MHz long term evolution (LTE) signals as the stimulus

Hyperparameter Optimization of Two-Hidden-Layer Neural Networks for Power Amplifiers Behavioral Modeling Using Genetic Algorithms

International audienceNeural networks (NN) are efficient techniques for behavioral modeling of power amplifiers (PA). This paper proposes a genetic algorithm to determine the optimal hyperparam-eters of the NN model for a PA. Different activation functions are compared. The necessary number of training epochs is also studied to get an optimal solution with a significantly reduced computational complexity. Experimental measurements on a PA with different signals validate the NN models determined by the proposed method