4,694 research outputs found

    CrossCarry: An R package for the analysis of data from a crossover design with GEE

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    Experimental crossover designs are widely used in medicine, agriculture, and other areas of the biological sciences. Due to the characteristics of the crossover design, each experimental unit has longitudinal observations and the presence of drag effects on the response variable. There is no package in {R} that clearly models data from crossover designs. The {CrossCarry} package presented in this paper allows testing any crossover design as long as the observed response variable belongs to the exponential family, regardless of whether or not there is a washout period. It also allows modeling repeated measurements within each period and extends the correlation structures used in the generalized estimating equations. The family of correlation structures is built that takes into account the particularities of the design, that is, the correlation between and within the periods. It also includes a parametric component for modeling treatment effects and a non-parametric component for modeling time effects and carry-over effects. The non-parametric component is estimated from splines inserted into the generalized estimation equations

    Electromagnetic Structure of the Pion

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    In this work, we analyze the electromagnetic structure of the pion. We calculate its electromagnetic radius and electromagnetic form factor in low and intermediate momentum range. Such observables are determined by means of a theoretical model that takes into account the constituent quark and antiquark of the pion within the formalism of light-front field theory. In particular, we consider a nonsymmetrical vertex in this model, with which we calculate the electromagnetic form factor of the pion in an optimized way, so that we obtain a value closer to the experimental charge radius of the pion. The theoretical calculations are also compared with the most recent experimental data involving the pion electromagnetic form factor and the results show very good agreement.Comment: Paper with 4 pages, 1 figure, presented in XII HADRON PHYSICS Conference - to appear in AIP Conference Proceeding

    Novel prefabricated panels for the repair of damaged interior RC beam-column joints

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    A novel prefabricated panel is introduced for the repair and strengthening of damaged interior RC beam-column joints. This prefabricated hybrid composite plate (HCP) is made of a Strain Hardening Cementitious Composite (SHCC) reinforced with CFRP materials. Besides the higher durability of this system when compared to EB-FRP, thanks to the high ductility of the SHCC, anchors can be used in combination with adhesive to attach the HCP to the concrete substrate. The first section of this paper reports the methodologies to apply HCP for the repair of two severely damaged interior RC beam-column systems. To evaluate the performance of this rehabilitation technique, the repaired specimens were subjected to the same loading pattern as it was imposed to their virgin states. Since both repaired specimens showed a higher lateral load and energy dissipation capacities than the corresponding values in their undamaged state, the effectiveness of the HCP for the repair of damaged interior beam-column joints is proved.Fundação para a Ciência e a Tecnologia (FCT

    Aplicação de diferentes frequências e concentrações de substancias húmicas na produtividade de banana (cv. Princesa).

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    A aplicação de substâncias húmicas tem sido uma das alternativas para proporcionar melhores produtividades e para mitigar os efeitos da degradação do solo e, uma vez que as substâncias húmicas atuam como agente cimentante entre as partículas, aumenta a capacidade de troca de cátions, disponibilizando mais nutrientes às plantas, e serve como fonte de alimento para a biota do solo

    Rates of tooth movement and bone remodeling activity : self-ligating versus conventional brackets

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    Background: Bracket systems have been developed with the purpose of reducing frictional resistance between the archwire and accessories. The aim of this research was to compare rates of tooth movement and regions of cellular bone modeling activity along tooth root surfaces of teeth moved with conventional vs. self-ligating brackets. Material and Methods: The experiments were conducted in 20 male dogs. Bands were cemented in all intermediate incisors, with conventional brackets (Morelli) on the right side and hybrid self-ligating ones (T3-American Ortho-dontics) on the left side. A 0.019? x 0.025? stainless steel wire was inserted passively in the slot of these brackets with chain elastics (250 gf) to perform sliding mechanics. Clinical records of the orthodontic mechanics were made before and after 15 days of the tooth movement. The dental segments of the animals were prepared for light micros-copy. Statistical analysis of variance and the Tukey correction with a P value at 5% were used. Results: There were no significant differences in tooth movement rates between the two types of brackets but di-fferences, in the bone modeling activity, suggested that tooth movement with the self-ligating brackets resulted in more tipping and less translational movement than tooth movement with the conventional brackets. Conclusions: The rates of tooth movement were similar between the two systems. The histological evaluation of cellular bone modeling activity along tooth root surfaces showed more translation movement of teeth with the con-ventional brackets, and more tipping movement of teeth with self-ligating brackets

    Efeito da adubação, níveis de água e densidade de plantas no estado nutricional da Bananeira CV. D'Angola.

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    O objetivo deste trabalho foi de avaliar o estado nutricional da bananeira cv. D?angola sob diferentes níveis de adubação, lâminas de irrigação e densidades de plantas na região dos tabuleiros costeiros. O delineamento experimental foi em blocos casualizados com quatro repetições, em esquema de parcelas subsubdivididas. As parcelas compreenderam os níveis de adubação (1,0; 1,25 e 1,5 da dose recomendado). As sub-parcelas compreenderam as lâminas de irrigação (60% e 100% da evapotranspiração da cultura) e as sub-subparcela as densidades com uma planta por cova (1600 plantas.hectare-1) e com duas plantas por cova (3200 planta.hectare-1) no espaçamento de 2,5 x 2,5 m. Avaliou - se o estado nutricional através de coletas de amostras da terceira folha a contar do ápice, com a inflorescência no estádio de todas as pencas femininas descobertas e daí quantificou os teores dos macro e micronutrientes. Verificou - se mediante analise de variância (teste F), que a densidade de plantio influenciou apenas os teores de fósforo. O teor de potássio foi superior na lâmina 100 % da evapotranspiração

    Efeito da adubação, níveis de água e densidade de plantas no rendimento da bananeira CV. D?Angola.

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    O objetivo desse trabalho foi avaliar o rendimento da bananeira cv. D?Angola com diferentes densidades de plantas, sob duas lâminas de irrigação e três níveis de adubação na região dos tabuleiros costeiros. O delineamento experimental foi em blocos casualizados com quatro repetições, em esquema de parcelas subsubdivididas. As parcelas compreenderam os níveis de adubação (1,0; 1,25 e 1,5 da dose recomendado). As sub-parcelas compreenderam as lâminas de irrigação (60% e 100% da evapotranspiração da cultura) e as sub-subparcela as densidades com uma planta por cova (1600 plantas.hectare-1) e com duas plantas por cova (3200 planta.hectare-1) no espaçamento de 2,5 x 2,5 m. Avaliou ? se número de folhas vivas na colheita, massa de pencas por cacho, massa do cacho, número de pencas por cacho, número de frutos por cacho, comprimento e diâmetro médio do fruto (dedo central da segunda penca). Verificou - se mediante analise de variância (teste F), que a densidade de plantio influenciou todas as variáveis de rendimentos estudadas. A condução de duas plantas por touceira aumentou a produtividade de pencas e cacho na ordem de 69,53 e 69,61%
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