1,039 research outputs found
Principal Motives of Positive Youth-Adult Relationships: A Model for Identifying the Motives of Adult Volunteers and Youth-Adult Relationships in Physical Activity-Based Youth Development Programs
The field of positive youth development has evolved in response to the growing effort to provide youth with safe and healthful activities during leisure time. Physical activity-based youth development programs (PA-based YDPs) utilize a range of individual and team sports and physical activities as tools to simultaneously teach character development and physical skills for the acquisition of life skills. The intentional focus on positive youth development provides a suitable context for the development of a youth-adult relationship (YAR). The bonding between a youth and adult is critical to the development of adaptive responses and life skills which ultimately impact the functionality of youth in adulthood. There is a limited understanding of the relationship between characteristics of adults who volunteer in PA-based YDPs and characteristics of YARs. Due to the importance of establishing a positive YAR within a PA-based YDP, it is useful to consider how the motivation of adult volunteers is related to characteristics of positive YARs. The purpose of this dissertation was to examine the relationship between volunteer adult motives and characteristics of YARs. Two studies, one using quantitative methods and one using qualitative methods, addressed this general purpose. The quantitative study examined the relationship between adult motivations and characteristics of YARs by testing the proposed model, Principal Motives of Positive Youth-Adult Relationships Model. The qualitative study used a semi-structured interview protocol with 12 volunteer adult leaders to investigate the motives of adult volunteers and their perceptions of YARs established in PA-based. Results of the study did not support the hypothesized model; however, it did provide justification for refining the model to focus on one YAR characteristic (trust/respect) as it may relate to volunteer motivation. The study did provide evidence to support a relationship between the satisfaction of volunteer motivation and the development of YARs. Additionally, facilitators of YAR development focused on the presence of two YAR characteristics. Implications for the broad base of positive YDPs and youth sport settings along with directions for future research are included
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A pipeline for targeted metagenomics of environmental bacteria.
BackgroundMetagenomics and single cell genomics provide a window into the genetic repertoire of yet uncultivated microorganisms, but both methods are usually taxonomically untargeted. The combination of fluorescence in situ hybridization (FISH) and fluorescence activated cell sorting (FACS) has the potential to enrich taxonomically well-defined clades for genomic analyses.MethodsCells hybridized with a taxon-specific FISH probe are enriched based on their fluorescence signal via flow cytometric cell sorting. A recently developed FISH procedure, the hybridization chain reaction (HCR)-FISH, provides the high signal intensities required for flow cytometric sorting while maintaining the integrity of the cellular DNA for subsequent genome sequencing. Sorted cells are subjected to shotgun sequencing, resulting in targeted metagenomes of low diversity.ResultsPure cultures of different taxonomic groups were used to (1) adapt and optimize the HCR-FISH protocol and (2) assess the effects of various cell fixation methods on both the signal intensity for cell sorting and the quality of subsequent genome amplification and sequencing. Best results were obtained for ethanol-fixed cells in terms of both HCR-FISH signal intensity and genome assembly quality. Our newly developed pipeline was successfully applied to a marine plankton sample from the North Sea yielding good quality metagenome assembled genomes from a yet uncultivated flavobacterial clade.ConclusionsWith the developed pipeline, targeted metagenomes at various taxonomic levels can be efficiently retrieved from environmental samples. The resulting metagenome assembled genomes allow for the description of yet uncharacterized microbial clades. Video abstract
The Imagined and Real Jerusalem in Art and Architecture
In The Imagined and Real Jerusalem in Art and Architecture specialists in various fields of art history, from Early Christian times to the present, discuss in depth a series of Western artworks, artefacts, and buildings, which question the visualization of Jerusalem
Le département de l’Eure sous la République directoriale
Étudier la période directoriale dans le cadre d’un département, tel est le propos de cette thèse. Le territoire sur lequel a porté la recherche peut sembler restreint mais le cadre départemental apparaît néanmoins comme pertinent et s’impose au chercheur qui souhaite travailler sur la Révolution française. En effet, à partir de 1790, cette nouvelle circonscription administrative a constitué un espace cohérent où se déroulait une vie politique locale ayant son rythme propre, souvent différent ..
Nicolaus Goldmann (1611-1665) en de praktijk van de studeerkamer
In the middle of the seventeenth century Nicolaus Goldmann (1611-1665), who worked in Leyden as a private tutor of mathematics and architecture, published five books about architectural sciences. Two of these deal with fortification, one shows a mathematical design-instrument: the sector, another shows his own invention: an instrument for correctly designed columns.
His fifth booklet gives a proposal for a true Vitruvian ionic scroll (part of the ionic capital). He designed a comprehensive measuring and design system for civil architecture. He worked in line with the scientific spirit of his time, proceeding from mathematics. He was part of the social environment of Leyden University and the University training of engineers.
Apart from what Goldmann knew of German architecture and saw arising as Dutch Classicism, he absorbed the theoretical knowledge of his great predecessors from Italy. In the course of the lessons given by him in this field his insight matured. The lessons served as a basis for a theory which was definitely brought to completion in the form of a manuscript in 1659.
The manuscript is probably the only complete theory of architecture ever written in the Dutch Republic. However, it was not published until the end of the seventeenth century, under a different title, under a different sky, and due to the engravings of a totally different character: in 1696 Goldmann's treatise was published in WolfenbĂĽttel as Vollstandige Anweisung zu der Civil-Baukunst, in an adaptation made by the mathematician and architect Leonhard Christoph Sturm (1669-1719).
It is extraordinary that besides the printed publication the manuscript was also preserved in five copies. Apart from the book and the manuscripts, sketches, notebooks, calculations and a few printed works of Goldmann's hand have been preserved as well. With the aid of this material the printed book undergoes a remarkable transformation: from a late 17th-century publication in the dukedom of Braunschweig the range of thought returns to the atmosphere of Dutch Classicism of half a century earlier.
This article gives a brief introduction to the life, writings and theory of architecture of Nicolaus Goldmann. The theory is sketched in broad lines on the basis of some examples from the manuscripts. Goldmann's drawings and comments are of great importance to understand the original text. They show us the principals of Goldmann's severe design-system and they create the building types which stay obscure in the later Sturm-edition
Internal friction and its thermal evolution on 304 L stainless steel films
Internal friction has been measured between 300 and 760K on 304 L stainless steel (SS) using a vibrating reed device. The 0.6 µm thick samples were deposited with ion beam sputtering technique on (100) silicon substrate. It has been shown that the damping level is considerably reduced by annealing between 500 and 760K. The calculated activation energy and the reaction order, using the Johnson-Mehl-Avrami (J-M-H) kinetic enable us to assume that the observed mechanism is closely related to microstructural rearrangements located at grain boundaries.Internal friction has been measured between 300 and 760K on 304 L stainless steel (SS) using a vibrating reed device. The 0.6 µm thick samples were deposited with ion beam sputtering technique on (100) silicon substrate. It has been shown that the damping level is considerably reduced by annealing between 500 and 760K. The calculated activation energy and the reaction order, using the Johnson-Mehl-Avrami (J-M-H) kinetic enable us to assume that the observed mechanism is closely related to microstructural rearrangements located at grain boundaries
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Elizabeth Bishop and Brazil
textElizabeth Bishop's phenomenal rise in the academic canon is due in large part to the way her writings about Brazil correlate with current critical concerns. However, U.S. scholars have relied on an inchoate understanding of Bishop's sociohistorical contexts as she performed complicated and at times contradictory Brazil(s). Using Yi-Fu Tuan's methodology of space and place and James Clifford's dichotomy of routes/roots, I delineate between four discrete Brazil(s) in Bishop's texts. Shifts between these Brazil(s) are predicated on changes in Bishop's relationship with her Brazilian partner, Lota Macedo de Soares. I explore the eleven poems of the "Brazil" section of Questions of Travel and "Crusoe in England," as well as the introductions and translations she worked on contemporaneously. Bishop's tourist poems examine the tension between her expectations of the banana-ized Brazil of the popular Carmen Miranda movies, and the reality that she discovered as she moves from a tourist-voyeur to a rooted expatriate. In her Samambaia poems, she writes from the position of insider/partner about the subaltern public sphere that Lota has created at her farm outside of Rio de Janeiro. The volatility of the Brazilian political situation, which Bishop blamed for the dissolution of her relationship with Lota, led Bishop to define the primitive aspects of Brazil that Lota disdained. Finally, I argue that her translation strategies as she writes about Brazil after Lota's death in 1967 are a nostalgic return to her earliest views of Brazil.Englis
Wireless Electromechanical Readout of Chemical Information
International audienceCollecting electrochemical information concerning the presence of molecules in a solution is usually achieved by measuring current, potential, resistance or impedance via connection to a power supply. Here, we suggest wireless electromechani-cal actuation as a straightforward readout of chemical information. This can be achieved based on the concept of bipolar electro-chemistry, which allows measuring the presence of different model species in a quantitative way. We validate the concept by using a free-standing polypyrrole film. Its positively polarized extremity participates in an oxidation of the analyte and delivers electrons to the opposite extremity for the reduction of the polymer. This reduction is accompanied by the insertion of counter ions and thus leads to partial swelling of the film, inducing its bending. The resulting actuation is found to be a linear function of the analyte concentration and also a Michaelis-Menten type correlation is obtained for biochemical analytes. This electromechanical transduc-tion allows an easy optical readout and opens up very interesting perspectives not only in the field of sensing, but also far beyond, such as for the elaboration of self-regulating biomimetic systems
Les résistances aux benzimidazoles chez les caprins : enquête épidémiologique et essais de traitement sélectif
Les résistances aux anthelminthiques chez les nématodes du tractus digestif, représentent un problème majeur de gestion du parasitisme chez les caprins. Afin d'appréhender ce problème au sein des élevages, une enquête parasitaire suivi de la mise en place d'un essai de traitement sélectif ont été réalisés au cours de deux années d'étude portant sur dix élevages du centre de la France. Les résultats de l'enquête montrent que le mode usuel de maîtrise du parasitisme repose sur l'usage répété de molécules anthelminthiques mais qu'existe un manque d'informations des éleveurs sur les modalités appropriées d'utilisation des vermifuges chez cette espèce. Cette méconnaissance se traduit en pratique par des sous-dosages des produits. Associés à une fréquence élevée de traitements, ils sont à l'origine de l'émergence et du développement des résistances aux anthelminthiques. Ainsi, au cours de notre étude, deux élevages sur dix se sont révélés résistants aux benzimidazoles. Cette prévalence élevée des résistances oblige donc à rechercher d'autres modes de contrôle du parasitisme. Il est en effet, nécessaire de préserver l'efficacité des molécules anthelminthiques chez les caprins car dans cette espèces le choix reste limité. Une alternative possible pour lutter contre les chimiorésistances, est de traiter selectivement les troupeaux ; le but étant de maintenir au sein des populations de vers des allèles de susceptibilité pour diluer ceux à l'origine de la résistance. Un traitement ciblé visant les seuls animaus les plus excréteurs, donc les plus contaminants permet d'atteindre cet objectif. Chez les chèvres laitières, notre étude a montré qu'il s'agissait essentiellement des hautes productrices et dans une moindre mesure des primipares. L'essai de ce type de traitements appliqué, dans les élevages, sur toute une année, a donné des résutats encourageants : tout en diminuant la fréquence d'emploi des anthelminthiques, les éleveurs ont maintenu un parasitism faible au sein des troupeaux ainsi qu'un niveau de production satisfaisant
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