809 resultados para Change-over Designs
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Background: Partially clonal organisms are very common in nature, yet the influence of partial asexuality on the temporal dynamics of genetic diversity remains poorly understood. Mathematical models accounting for clonality predict deviations only for extremely rare sex and only towards mean inbreeding coefficient (F-IS) over bar < 0. Yet in partially clonal species, both F-IS < 0 and F-IS > 0 are frequently observed also in populations where there is evidence for a significant amount of sexual reproduction. Here, we studied the joint effects of partial clonality, mutation and genetic drift with a state-and-time discrete Markov chain model to describe the dynamics of F-IS over time under increasing rates of clonality. Results: Results of the mathematical model and simulations show that partial clonality slows down the asymptotic convergence to F-IS = 0. Thus, although clonality alone does not lead to departures from Hardy-Weinberg expectations once reached the final equilibrium state, both negative and positive F-IS values can arise transiently even at intermediate rates of clonality. More importantly, such "transient" departures from Hardy Weinberg proportions may last long as clonality tunes up the temporal variation of F-IS and reduces its rate of change over time, leading to a hyperbolic increase of the maximal time needed to reach the final mean (F-IS,F-infinity) over bar value expected at equilibrium. Conclusion: Our results argue for a dynamical interpretation of F-IS in clonal populations. Negative values cannot be interpreted as unequivocal evidence for extremely scarce sex but also as intermediate rates of clonality in finite populations. Complementary observations (e.g. frequency distribution of multiloci genotypes, population history) or time series data may help to discriminate between different possible conclusions on the extent of clonality when mean (F-IS) over bar values deviating from zero and/or a large variation of F-IS over loci are observed.
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Background: Long-term exposure to infrasound and low frequency noise (ILFN <500 Hz, including infrasound) can lead to the development of vibroacoustic disease (VAD). VAD is a systemic pathology characterized by the abnormal growth of extracellular matrices in the absence of inflammatory processes, namely of collagen and elastin, both of which are abundant in the basement membrane zone of the vocal folds. ILFN-exposed workers include pilots, cabin crewmembers, restaurant workers, ship machinists and, in previous studies, even though they did not present vocal symptoms, ILFN-exposed workers had significant different voice acoustic patterns (perturbation and temporal measures) when compared with normative population. Study Aims: The present study investigates the effects of age and years of occupational ILFN-exposure on voice acoustic parameters of 37 cabin crewmembers: 12 males and 25 females. Specifically, the goals of this study are to: 1) Verify if acoustic parameters change over the age and years of ILFN-exposure and 2) Determine if there is any interaction between age and years of ILFNexposure on voice acoustic parameters of crewmembers. Materials and Methods: Spoken phonatory tasks were recorded with a C420III PP AKG head-worn microphone and a DA-P1 Tascam DAT. Acoustic analyses were performed using KayPENTAX Computer Speech Lab and Multi-Dimensional Voice Program. Acoustic parameters included speaking fundamental frequency, perturbation measures (jitter, shimmer and harmonicto- noise ratio), temporal measures (maximum phonation time and s/z ratio) and voice tremor frequency. Results: One-way ANOVA analysis revealed that as the number of ILFN-exposure years increased male cabin crewmembers presented significant different shimmer values of /i/ as well as tremor frequency of /u/. Females presented significantly different jitter % of /i, a, O/ (p <0.05). Lastly, Two-way ANOVA analysis revealed that for females, there was a significant interaction between age and occupational ILFN-exposure for voice acoustic parameters, namely for jitter’s mean for /a, O/ and shimmer’s (%) mean for /a, i/ (p <0.05). Discussion and Conclusion: These perturbation measure patterns may be indicative of histological changes within the vocal folds as a result of ILFN-exposure. The results of this study suggest that voice acoustic analysis may be an important tool for confirming ILFN-induced health effects.
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Restoration of natural wetlands may be informed by macroinvertebrate community composition. Macroinvertebrate communities of wetlands are influenced by environmental characteristics such as vegetation, soil, hydrology, land use, and isolation. This dissertation explores multiple approaches to the assessment of wetland macroinvertebrate community composition, and demonstrates how these approaches can provide complementary insights into the community ecology of aquatic macroinvertebrates. Specifically, this work focuses on macroinvertebrates of Delmarva Bays, isolated seasonal wetlands found on Maryland’s eastern shore. A comparison of macroinvertebrate community change over a nine years in a restored wetland complex indicated that the macroinvertebrate community of a rehabilitated wetlands more rapidly approximated the community of a reference site than did a newly created wetland. The recovery of a natural macroinvertebrate community in the rehabilitated wetland indicated that wetland rehabilitation should be prioritized over wetland creation and long-term monitoring may be needed to evaluate restoration success. This study also indicated that characteristics of wetland vegetation reflected community composition. The connection between wetland vegetation and macroinvertebrate community composition led to a regional assessment of predaceous diving beetle (Coleoptera: Dytiscidae) community composition in 20 seasonal wetlands, half with and half without sphagnum moss (Sphagnum spp.). Species-level identifications indicated that wetlands with sphagnum support unique and diverse assemblages of beetles. These patterns suggest that sphagnum wetlands provide habitat that supports biodiversity on the Delmarva Peninsula. To compare traits of co-occurring beetles, mandible morphology and temporal and spatial variation were measured between three species of predaceous diving beetles. Based on mandible architecture, all species may consume similarly sized prey, but prey characteristics likely differ in terms of piercing force required for successful capture and consumption. Therefore, different assemblages of aquatic beetles may have different effects on macroinvertebrate community structure. Integrating community-level and species-level data strengthens the association between individual organisms and their ecological role. Effective restoration of imperiled wetlands benefits from this integration, as it informs the management practices that both preserve biodiversity and promote ecosystem services.
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A qualidade é um conceito que vem sendo cada vez mais explorado e os sistemas de gestão da qualidade encontram-se em franco desenvolvimento quer nas indústrias, onde o conceito de qualidade foi inicialmente implementado, quer nos serviços. Paralelamente, existe já também uma tendência, ainda que um pouco embrionária de aplicação de sistemas de qualidade aos serviços de saúde. Os primeiros passos foram tomados. No entanto, a qualidade em saúde carece ainda de uma efetiva concretização. Os sistemas de qualidade a implementar nos serviços de saúde e que, como nas outras áreas, visam a melhoria continua, encontram algumas dificuldades nesta área, que começam com o facto de conceitos como saúde e doença, serem muito subjetivos e de fácil mutação ao longo dos tempos. Os indicadores de qualidade visam avaliar aquilo que à partida é de difícil mensuração, no sentido de tornar eficientes os processos em causa, garantindo a qualidade do produto/serviço, tem em vista a melhoria continua. Assim, a implementação de indicadores que sejam particularmente sensíveis aos cuidados de enfermagem, poderá constituir-se como uma tarefa inovadora e ao mesmo tempo complexa, no sentido de evidenciar o trabalho destes profissionais na área da saúde
Représentations identitaires chez un homme ayant purgé une longue peine : aspects stables et mobiles
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Nombre de recherches portent sur la question de l’abandon de la délinquance et du processus de désistance qui la précède. Bien que les angles d’approche soient diversifiés, elles s’entendent pour dire que ce processus implique des changements sociaux autant que personnels. Ce mémoire s’est intéressé à la question des changements identitaires chez des individus qui avaient été condamnés à une longue peine d’emprisonnement et qui ont obtenu leur libération conditionnelle totale. Le principal objectif de ce mémoire est de comprendre en quoi les aspects permanents de l’identité et ceux qui sont modifiables sont à l’œuvre dans la trajectoire de changement d’un homme condamné à perpétuité pour meurtre et qui a obtenu sa libération conditionnelle totale. La méthode qualitative qu’est le récit de vie, et selon une perspective phénoménologique, a été utilisée afin d’atteindre les objectifs de cette recherche. Un homme condamné à une sentence de prison à vie, mais ayant obtenu sa libération totale a été rencontré en dix entretiens en profondeur d’une durée d’une heure à une heure et demie. Nous avons choisi de procéder à un nombre élevé d’entretiens de type semi-directifs afin de permettre l’approfondissement des propos de l’individu rencontré. Les résultats suggèrent que certaines représentations de l’identité restent stables dans le temps alors que d’autres se transforment au fil de la trajectoire de vie. En effet, de l’analyse du récit de vie de l’individu se dégagent deux représentations stables, qui marquent durablement l’identité de ce dernier dans sa trajectoire de vie, et quatre modifiables, qui se sont développées au cours de sa détention. Les résultats montrent aussi que les représentations stables semblent intervenir autant dans le processus criminogène que dans celui de la désistance.
Représentations identitaires chez un homme ayant purgé une longue peine : aspects stables et mobiles
Resumo:
Nombre de recherches portent sur la question de l’abandon de la délinquance et du processus de désistance qui la précède. Bien que les angles d’approche soient diversifiés, elles s’entendent pour dire que ce processus implique des changements sociaux autant que personnels. Ce mémoire s’est intéressé à la question des changements identitaires chez des individus qui avaient été condamnés à une longue peine d’emprisonnement et qui ont obtenu leur libération conditionnelle totale. Le principal objectif de ce mémoire est de comprendre en quoi les aspects permanents de l’identité et ceux qui sont modifiables sont à l’œuvre dans la trajectoire de changement d’un homme condamné à perpétuité pour meurtre et qui a obtenu sa libération conditionnelle totale. La méthode qualitative qu’est le récit de vie, et selon une perspective phénoménologique, a été utilisée afin d’atteindre les objectifs de cette recherche. Un homme condamné à une sentence de prison à vie, mais ayant obtenu sa libération totale a été rencontré en dix entretiens en profondeur d’une durée d’une heure à une heure et demie. Nous avons choisi de procéder à un nombre élevé d’entretiens de type semi-directifs afin de permettre l’approfondissement des propos de l’individu rencontré. Les résultats suggèrent que certaines représentations de l’identité restent stables dans le temps alors que d’autres se transforment au fil de la trajectoire de vie. En effet, de l’analyse du récit de vie de l’individu se dégagent deux représentations stables, qui marquent durablement l’identité de ce dernier dans sa trajectoire de vie, et quatre modifiables, qui se sont développées au cours de sa détention. Les résultats montrent aussi que les représentations stables semblent intervenir autant dans le processus criminogène que dans celui de la désistance.
Resumo:
Within a country social conditions change over time and these conditions vary from country to country. The associations between these conditions, somatic growth, physical activity and fitness reflect these changes. Aim: The study documented variation in somatic growth, physical activity and fitness associated with socio-economic status (SES). Subjects and methods: The study involved 507 subjects (256 boys and 251 girls) from the Madeira Growth Study, a mixed longitudinal study of five cohorts (8, 10, 12, 14 and 16 years of age) followed at yearly intervals over 3 years (1996–1998). A total of 1493 observations were made. Anthropometric measurements included lengths, body mass, skeletal breadths, girths and skinfolds. Physical activity and SES were collected via questionnaire and interview. Physical fitness was assessed using the Eurofit test battery. Variation in somatic growth, physical activity and physical fitness by SES (high, average and low) was tested with analysis of variance. Results: Significant differences between SES groups were observed for height, body mass and skinfolds. Boys and girls from high SES groups were taller, heavier and fatter (subscapular and triceps skinfolds) than their peers from average and low SES groups. At some age intervals, the high SES group had larger skeletal breadths (girls) and girths (boys and girls) than low SES. Small SES differences were observed for physical activity (sport and leisure-time indices). SES was significantly associated with physical fitness. At some age levels, boys from the low SES group performed better for muscular and aerobic endurance whereas girls from the high SES group performed better for power. Conclusion: Considerable variation in somatic growth and physical fitness in association with SES has been demonstrated, but little association was found for physical activity.
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This article explores Ulrich Beck’s theorisation of risk society through focusing on the way in which the risk of Bt cotton is legitimated by six cultivators in Bantala, a village in Warangal, Andhra Pradesh, in India. The fieldwork for this study was conducted between June 2010 and March 2011, a duration chosen to coincide with a cotton season. The study explores the experience of the cultivators using the ‘categories of legitimation’ defined by Van Leeuwen. These are authorisation, moral evaluation, rationalisation and mythopoesis. As well as permitting an exploration of the legitimation of Bt cotton by cultivators themselves within the high-risk context of the Indian agrarian crisis, the categories also serve as an analytical framework with which to structure a discourse analysis of participant perspectives. The study examines the complex trade-off, which Renn argues the legitimation of ambiguous risk, such as that associated with Bt technology, entails. The research explores the way in which legitimation of the technology is informed by wider normative conceptualisations of development. This highlights that, in a context where indebtedness is strongly linked to farmer suicides, the potential of Bt cotton for poverty alleviation is traded against the uncertainty associated with the technology’s risks, which include its purported links to animal deaths. The study highlights the way in which the wider legitimation of a neoliberal approach to development in Andhra Pradesh serves to reinforce the choice of Bt cotton, and results in a depoliticisation of risk in Bantala. The research indicates, however, that this trade-off is subject to change over time, as economic benefits wane and risks accumulate. It also highlights the need for caution in relation to the proposed extension of Bt technology to food crops, such as Bt brinjal (aubergine).
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Things change. Words change, meaning changes and use changes both words and meaning. In information access systems this means concept schemes such as thesauri or clas- sification schemes change. They always have. Concept schemes that have survived have evolved over time, moving from one version, often called an edition, to the next. If we want to manage how words and meanings - and as a conse- quence use - change in an effective manner, and if we want to be able to search across versions of concept schemes, we have to track these changes. This paper explores how we might expand SKOS, a World Wide Web Consortium (W3C) draft recommendation in order to do that kind of tracking.The Simple Knowledge Organization System (SKOS) Core Guide is sponsored by the Semantic Web Best Practices and Deployment Working Group. The second draft, edited by Alistair Miles and Dan Brickley, was issued in November 2005. SKOS is a “model for expressing the basic structure and content of concept schemes such as thesauri, classification schemes, subject heading lists, taxonomies, folksonomies, other types of controlled vocabulary and also concept schemes embedded in glossaries and terminologies” in RDF. How SKOS handles version in concept schemes is an open issue. The current draft guide suggests using OWL and DCTERMS as mechanisms for concept scheme revision.As it stands an editor of a concept scheme can make notes or declare in OWL that more than one version exists. This paper adds to the SKOS Core by introducing a tracking sys- tem for changes in concept schemes. We call this tracking system vocabulary ontogeny. Ontogeny is a biological term for the development of an organism during its lifetime. Here we use the ontogeny metaphor to describe how vocabularies change over their lifetime. Our purpose here is to create a conceptual mechanism that will track these changes and in so doing enhance information retrieval and prevent document loss through versioning, thereby enabling persistent retrieval.
Resumo:
As the universe of knowledge and subjects change over time, indexing languages like classification schemes, accommodate that change by restructuring. Restructuring indexing languages affects indexer and cataloguer work. Subjects may split or lump together. They may disappear only to reappear later. And new subjects may emerge that were assumed to be already present, but not clearly articulated (Miksa, 1998). In this context we have the complex relationship between the indexing language, the text being described, and the already described collection (Tennis, 2007). It is possible to imagine indexers placing a document into an outdated class, because it is the one they have already used for their collection. However, doing this erases the semantics in the present indexing language. Given this range of choice in the context of indexing language change, the question arises, what does this look like in practice? How often does this occur? Further, what does this phenomenon tell us about subjects in indexing languages? Does the practice we observe in the reaction to indexing language change provide us evidence of conceptual models of subjects and subject creation? If it is incomplete, but gets us close, what evidence do we still require?
Resumo:
Within a country social conditions change over time and these conditions vary from country to country. The associations between these conditions, somatic growth, physical activity and fitness reflect these changes. Aim: The study documented variation in somatic growth, physical activity and fitness associated with socio-economic status (SES). Subjects and methods: The study involved 507 subjects (256 boys and 251 girls) from the Madeira Growth Study, a mixed longitudinal study of five cohorts (8, 10, 12, 14 and 16 years of age) followed at yearly intervals over 3 years (1996–1998). A total of 1493 observations were made. Anthropometric measurements included lengths, body mass, skeletal breadths, girths and skinfolds. Physical activity and SES were collected via questionnaire and interview. Physical fitness was assessed using the Eurofit test battery. Variation in somatic growth, physical activity and physical fitness by SES (high, average and low) was tested with analysis of variance. Results: Significant differences between SES groups were observed for height, body mass and skinfolds. Boys and girls from high SES groups were taller, heavier and fatter (subscapular and triceps skinfolds) than their peers from average and low SES groups. At some age intervals, the high SES group had larger skeletal breadths (girls) and girths (boys and girls) than low SES. Small SES differences were observed for physical activity (sport and leisure-time indices). SES was significantly associated with physical fitness. At some age levels, boys from the low SES group performed better for muscular and aerobic endurance whereas girls from the high SES group performed better for power. Conclusion: Considerable variation in somatic growth and physical fitness in association with SES has been demonstrated, but little association was found for physical activity.
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El tema central de la presente monografía es mostrar la relación entre el discurso del movimiento 19 de abril (M-19) y sus acciones cometidas en el periodo de 1974 a 1990, a partir, de la explicación y aplicación de la teoría sobre el discurso de Teun Van Dijk, enfatizando en los conceptos de acción, contexto e ideología. Se analizaron los discursos hechos por el grupo guerrillero, relacionándolos con varias de sus acciones, lo que permitió ver cómo el discurso del M-19 al igual que su ideología cambiaron a través del tiempo; convirtiéndose, además, en un medio para justificar las acciones, dado que se pudo observar una concordancia entre las declaraciones, las palabras, y los actos políticos y revolucionarios del movimiento.
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Il dibattito giuridico, politico ed economico in tema di protezione dei diritti sociali nel contesto del processo di integrazione europea risale alle origini stesse di tale processo. A circa dieci anni dall’attribuzione alla Carta dei diritti fondamentali dell’UE dello stesso valore giuridico dei Trattati, sembra possibile tracciare un primo bilancio in termini di aspettative inverate ed aspettative non soddisfatte quanto alla giustiziabilità dei diritti sociali fondamentali contenuti nel Titolo IV direttamente o indirettamente al rapporto di impiego (articoli da 27 a 34). A questo fine, la tesi ha adottato una struttura tripartita capace di coniugare una metodologia di analisi pratica, in relazione alla giurisprudenza della Corte di giustizia UE post Lisbona (Capitolo III), con un’analisi dal carattere maggiormente teorico-ricostruttivo (Capitoli I e II). La ricerca cerca di dimostrare come tanto i più interessanti sviluppi quanto i limiti registratisi nella giurisprudenza della CGUE (rispettivamente, l’efficacia diretta, anche orizzontale, di alcuni di essi negli ordinamenti nazionali, e la determinazione del loro ambito di applicazione e delle modalità di interazione con il diritto secondario e primario) possano essere meglio compresi tenendo in debito conto il percorso ed il significato di ciascuno di tali diritti nel contesto del processo di integrazione europea. In breve, si sostiene che la “costituzionalizzazione” dei diritti sociali in esame abbia certamente un “valore aggiunto” che, tuttavia, riflette la natura sui generis e le finalità dell’Unione, il sistema di riparto di competenze tra Stati membri e Unione, ed il significato ultimo del sistema UE di tutela dei diritti fondamentali. Ciò non toglie che questi caratteri, con il tempo, possano infine mutare.
Resumo:
BACKGROUND: Age and the Glasgow Coma Scale (GCS) score on admission are considered important predictors of outcome after traumatic brain injury. We investigated the predictive value of the GCS in a large group of patients whose computerised multimodal bedside monitoring data had been collected over the previous 10 years. METHODS: Data from 358 subjects with head injury, collected between 1992 and 2001, were analysed retrospectively. Patients were grouped according to year of admission. Glasgow Outcome Scores (GOS) were determined at six months. Spearman's correlation coefficients between GCS and GOS scores were calculated for each year. RESULTS: On average 34 (SD: 7) patients were monitored every year. We found a significant correlation between the GCS and GOS for the first five years (overall 1992-1996: r = 0.41; p<0.00001; n = 183) and consistent lack of correlations from 1997 onwards (overall 1997-2001: r = 0.091; p = 0.226; n = 175). In contrast, correlations between age and GOS were in both time periods significant and similar (r = -0.24 v r = -0.24; p<0.002). CONCLUSIONS: The admission GCS lost its predictive value for outcome in this group of patients from 1997 onwards. The predictive value of the GCS should be carefully reconsidered when building prognostic models incorporating multimodality monitoring after head injury.