56 resultados para Antithetic variates


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Les fichiers qui accompagnent mon document ont été réalisés avec le logiciel Latex et les simulations ont été réalisés par Splus(R).

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Theory recently developed to construct confidence regions based on the parametric bootstrap is applied to add inferential information to graphical displays of sample centroids in canonical variate analysis. Problems of morphometric differentiation among subspecies and species are addressed using numerical resampling procedures.

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Background Breastfeeding is recognised as the optimal method for feeding infants with health gains made by reducing infectious diseases in infancy; and chronic diseases, including obesity, in childhood, adolescence and adulthood. Despite this, exclusivity and duration in developed countries remains resistant to improvement. The objectives of this research were to test if an automated mobile phone text messaging intervention, delivering one text message a week, could increase “any” breastfeeding rates and improve breastfeeding self-efficacy and coping. Methods Women were eligible to participate if they were: over eighteen years; had an infant less than three months old; were currently breastfeeding; no diagnosed mental illness; and used a mobile phone . Women in the intervention group received MumBubConnect, a text messaging service with automated responses delivered once a week for 8 weeks. Women in the comparison group received their usual care and were sampled two years after the intervention group. Data collection included online surveys at two time points, week zero and week nine, to measure breastfeeding exclusivity and duration, coping, emotions, accountability and self-efficacy. A range of statistical analyses were used to test for differences between groups. Hierarchical regression was used to investigate change in breastfeeding outcome, between groups, adjusting for co-variates. Results The intervention group had 120 participants at commencement and 114 at completion, the comparison group had 114 participants at commencement and 86 at completion. MumBubConnect had a positive impact on the primary outcome of breastfeeding behaviors with women receiving the intervention more likely to continue exclusive breastfeeding; with a 6% decrease in exclusive breastfeeding in the intervention group, compared to a 14% decrease in the comparison group (p < 0.001). This remained significant after controlling for infant age, mother’s income, education and delivery type (p = 0.04). Women in the intervention group demonstrated active coping and were less likely to display emotions-focussed coping (p < .001). There was no discernible statistical effect on self-efficacy or accountability. Conclusions A fully automated text messaging services appears to improve exclusive breastfeeding duration. The service provides a well-accepted, personalised support service that empowers women to actively resolve breastfeeding issues. Trial registration Australian New Zealand Clinical Trials Registry: ACTRN12614001091695.

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Merocyanine dyes that exhibit antithetic cyaninelike behaviour and giant first-order hyperpolarisability (beta) values have been designed. These cyanine-type dyes open up an intriguing route towards molecular-based electrooptic materials as well as new second-harmonic generation dyes for imaging.

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The identification of larval istiophorid billfishes from the western North Atlantic Ocean has long been problematic. In the present study, a molecular technique was used to positively identify 27 larval white marlin (Tetrapturus albidus), 96 larval blue marlin (Makaira nigricans), and 591 larval sailfish (Istiophorus platypterus) from the Straits of Florida and the Bahamas. Nine morphometric measurements were taken for a subset of larvae (species known), and lower jaw pigment patterns were recorded on a grid. Canonical variates analysis (CVA) was used to reveal the extent to which the combination of morphometric, pigment pattern, and month of capture information was diagnostic to species level. Linear regression revealed species-specific relationships between the ratio of snout length to eye orbit diameter and standard length (SL). Confidence limits about these relationships served as defining characters for sailfish >10 mm SL and for blue and white marlin >17 mm SL. Pigment pattern analysis indicated that 40% of the preflexion blue marlin examined possessed a characteristic lower jaw pigment pattern and that 62% of sailfish larvae were identifiable by lower jaw pigments alone. An identification key was constructed based on pigment patterns, month of capture, and relationships between SL and the ratio of snout length to eye orbit diameter. The key yielded identifications for 69.4% of 304 (blind sample) larvae used to test it; only one of these identifications was incorrect. Of the 93 larvae that could not be identified by the key, 71 (76.3%) were correctly identified with CVA. Although identif ication of certain larval specimens may always require molecular techniques, it is encouraging that the majority (92.4%) of istiophorid larvae examined were ultimately identifiable from external characteristics alone.

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Em estudos ecológicos é importante entender os processos que determinam a distribuição dos organismos. O estudo da distribuição de animais com alta capacidade de locomoção é um desafio para pesquisadores em todo o mundo. Modelos de uso de habitat são ferramentas poderosas para entender as relações entre animais e o ambiente. Com o desenvolvimento dos Sistemas de Informação Geográfica (SIG ou GIS, em inglês), modelos de uso de habitat são utilizados nas análises de dados ecológicos. Entretanto, modelos de uso de habitat frequentemente sofrem com especificações inapropriadas. Especificamente, o pressuposto de independência, que é importante para modelos estatísticos, pode ser violado quando as observações são coletadas no espaço. A Autocorrelação Espacial (SAC) é um problema em estudos ecológicos e deve ser considerada e corrigida. Nesta tese, modelos generalizados lineares com autovetores espaciais foram usados para investigar o uso de habitat dos cetáceos em relação a variáveis fisiográficas, oceanográficas e antrópicas em Cabo Frio, RJ, Brasil, especificamente: baleia-de-Bryde, Balaenoptera edeni (Capítulo 1); golfinho nariz-de-garrafa, Tursiops truncatus (Capítulo 2); Misticetos e odontocetos em geral (Capítulo 3). A baleia-de-Bryde foi influenciada pela Temperatura Superficial do Mar Minima e Máxima, no qual a faixa de temperatura mais usada pela baleia condiz com a faixa de ocorrência de sardinha-verdadeira, Sardinella brasiliensis, durante a desova (22 a 28C). Para o golfinho nariz-de-garrafa o melhor modelo indicou que estes eram encontrados em Temperatura Superficial do Mar baixas, com alta variabilidade e altas concentrações de clorofila. Tanto misticetos quanto os odontocetos usam em proporções similares as áreas contidas em Unidades de Conservação (UCs) quanto as áreas não são parte de UCs. Os misticetos ocorreram com maior frequência mais afastados da costa, em baixas temperaturas superficiais do mar e com altos valores de variabilidade para a temperatura. Os odontocetos usaram duas áreas preferencialmente: as áreas com as menores profundidades dentro da área de estudo e nas maiores profundidade. Eles usaram também habitats com águas frias e com alta concentração de clorofila. Tanto os misticetos quanto os odontocetos foram encontrados com mais frequência em distâncias de até 5km das embarcações de turismo e mergulho. Identificar habitats críticos para os cetáceos é um primeiro passo crucial em direção a sua conservação

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The research has studied, how Selectivity of attention develops from children (grade 2) to young adults (undergraduates) by the means of incidental learning tasks, in which two variates were used. One was the Semantic relation between target and context, the other was methods of processing (identifying) target. The results were: (1) Selectivity of attention develops with increasing of age. (2) Selectivity of attention is more greatly affected by the semantic relation between target and context with increasing of age. The phenomeon may be caused by that the adults are more proficient in processing semantic information than the children. (3) The older the individual is, the less Selectivity of attention is affected by the processing methods. It perhaps proves that the adults process semantic information more automaticly.

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Aims: To determine whether or not self reported visual functioning and quality of life in patients with choroidal neovascularisation caused by age related macular degeneration (AMD) is better in those treated with 12 Gy external beam radiotherapy in comparison with untreated subjects. Methods: A multicentre single masked randomised controlled trial of 12 Gy of external beam radiation therapy (EBRT) delivered as 6x2 Gy fractions to the macula of an affected eye versus observation. Patients with AMD, aged 60 years or over, in three UK hospital units, who had subfoveal CNV and a visual acuity equal to or better than 6/60 (logMAR 1.0). Methods: Data from 199 eligible participants who were randomly assigned to 12 Gy teletherapy or observation were available for analysis. Visual function assessment, ophthalmic examination, and fundus fluorescein angiography were undertaken at baseline and at 3, 6, 12, and 24 months after study entry. To assess patient centred outcomes, subjects were asked to complete the Daily Living Tasks Dependent on Vision (DLTV) and the SF-36 questionnaires at baseline, 6, 12, and 24 months after enrolment to the study. Cross sectional and longitudinal analyses were conducted using arm of study as grouping variable. Regression analysis was employed to adjust for the effect of baseline co-variates on outcome at 12 months and 24 months. Results: Both control and treated subjects had significant losses in visual functioning as seen by a progressive decline in mean scores in the four dimensions of the DLTV. There were no statistically significant differences between treatment and control subjects in any of dimensions of the DLTV at 12 months or 24 months after study entry. Regression analysis confirmed that treatment status had no effect on the change in DLTV dimensional scores. Conclusions: The small benefits noted in clinical measures of vision in treated eyes did not translate into better self reported visual functioning in patients who received treatment when compared with the control arm. These findings have implications for the design of future clinical trials and studies.

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This article takes as its starting point earlier research reported by Geoffrey Elliott in 1996. That study found that research was consistantly marginalised in the FE sector, and identified a number of structural factors that contributed to this ‘invisibility’. This new study draws upon a small sample of lecturers who belong to a Further and Higher Education Early Years Partnership. Through the participants’ voices and perspectives, the authors identify continuing dissonance and issues of research marginalisation. The discussion also highlights contemporary educational discourse, with its predominant focus upon measurable value at the expense of values, as a key factor in sustaining a culture that is antithetic to thoughtful reflection and research. The authors identify the development of a ‘collaborative centralised’ research community as critical to an alternative possibility for research in further education.

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Micromorphology is used to analyze a wide range of sediments. Many microstructures have, as yet, not been analyzed. Rotation structures are the least understood of microstructures: their origin and development forms the basis of this thesis. Direction of rotational movement helps understand formative deformational and depositional processes. Twenty-eight rotation structures were analyzed through two methods of data extraction: (a) angle of grain rotation measured from Nikon NIS software, and (b) visual analyses of grain orientation, neighbouring grainstacks, lineations, and obstructions. Data indicates antithetic rotation is promoted by lubrication, accounting for 79% of counter-clockwise rotation structures while 21 % had clockwise rotation. Rotation structures are formed due to velocity gradients in sediment. Subglacial sediments are sheared due to overlying ice mass stresses. The grains in the sediment are differentially deformed. Research suggests rotation structures are formed under ductile conditions under low shear, low water content, and grain numbers inducing grain-to-grain interaction.

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Thèse réalisée en cotutelle avec l'Université Paris-Sorbonne (Paris IV), sous la direction de M. Michel Delon.

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El trabajo inquiere, examina y condena la concepción bíblico-antigua con el cual se ha pretendido acrisolar a las convenciones jurídicas bajo el estigma de la objetividad, especialmente en el contexto de la Responsabilidad Civil Extracontractual de la Administración Pública, contrastado con el débito acaecido una vez presente un juicio orgánico, esto es, la falla del servicio, supuesto extraído en el interactuar antitético de las autoridades públicas respecto de una obligación primaria de cuidado debido, esto es, una norma legal pre-constituida al momento de la actuación material o acto administrativo. Supuesta tal objetividad en la falla del servicio, una dicotomía se presupone en su contra, la elasticidad con que ésta teoría pretende amalgamar bajo unos mismos y nunca cambiantes elementos de imputación jurídica en manos del juez siempre una única responsabilidad en las autoridades públicas. Y por otro lado, la incidencia de la teoría en la praxis, pragmática que no deja de insinuar lo contrario, esto es, supone desavenencias inexpugnables en la aplicación de tales premisas supuestas objetivas. Luego, resultado de este cisma es la indeterminación en la concepción falla del servicio, como concepto que no conoce contornos definidos, lo cual ofrece como síntoma de su abstrusa constitución una espiritual-subjetiva aplicación, y un cuestionamiento ineludible ¿existen líneas jurisprudenciales cuando de responsabilidad extracontractual se trata, en particular, en la falla del servicio?