Efeito da ovariectomia em novilhas Nelore x Angus, Bos taurus indicus x Bos taurus taurus sobre os ganhos de peso

This study aimed to evaluate the weight gain in cross breed heifers Nelore X Angus, spayed and nonspayed, kept on pasture and confinement. The animals were allotted in two groups as follows: group I consisted of 30 nonspayed heifers with 18 months old. Group 2 was composed of 30 spayed heifers with 18 months old. The animals were allotted in pasture of Brachiaria decumbens and weighted at 39 and 75 days. Significant difference was observed between the average daily gain of the two groups - G1 and G2 (75(th) day), respectively (0.51 kg and 0.65 kg; P<0.0 1). The following day (761 day), all animals were allotted and kept on confinement during 144 days. Significant difference was observed between the average daily gain of the two groups - G I and G2 (1441 day), respectively (0.73 kg and 0.58 kg; P<0.0 1). The results of this experiment show that spayed heifers presented a higher daily gain on pasture.

Pasti-Sorokin-Tonin actions in the presence of sources

Pasti, Sorokin, and Tonin have recently constructed manifestly Lorentz-invariant actions for self-dual field strengths and for Maxwell fields with manifest electromagnetic duality. Using the method of Deser et al., we generalize these actions in the presence of sources.

Análise histopatológica e ultraestrutural do esôfago distal de ratos com lesão cáustica submetidos à aplicação tópica de mitomicina C

Pós-graduação em Bases Gerais da Cirurgia - FMB

Avaliação da influência do método de polimerização e da espessura da base de próteses totais na porosidade da resina acrílica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Potenciais efeitos da estimulação tátil no comportamento e desenvolvimento de cordeiros e leitões

Pós-graduação em Zootecnia - FCAV

Desenvolvimento do útero grávido e da glândula mamária e mudanças corporais em cabras leiteiras durante a gestação

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inversão gravimétrica do relevo de bacias extencionais através da variação total

Apresentamos um método de inversão de dados gravimétricos para a reconstrução do relevo descontínuo do embasamento de bacias sedimentares, nas quais o contraste de densidade entre o pacote sedimentar e o embasamento são conhecidos a priori podendo apresentar-se constante, ou decrescer monotonicamente com a profundidade. A solução é estabilizada usando o funcional variação total (VT), o qual não penaliza variações abruptas nas soluções. Comparamos o métodoproposto com os métodos da suavidade global (SG), suavidade ponderada (SP) e regularização entrópica (RE) usando dados sintéticos produzidos por bacias 2D e 3D apresentando relevos descontínuos do embasamento. As soluções obtidas com o método proposto foram melhores do que aquelas obtidas com a SG e similares às produzidas pela SP e RE. Por outro lado, diferentemente da SP, o método proposto não necessita do conhecimento a priori sobre a profundidade máxima do embasamento. Comparado com a RE, o método VT é operacionalmente mais simples e requer a especificação de apenas um parâmetro de regularização. Os métodos VT, SG e SP foram aplicados, também, às seguintes áreas: Ponte do Poema (UFPA), Steptoe Valley (Nevada, Estados Unidos), Graben de San Jacinto (Califórnia, Estados Unidos) e Büyük Menderes (Turquia). A maioria destas áreas são caracterizadas pela presença de falhas com alto ângulo. Em todos os casos, a VT produziu estimativas para a topografia do embasamento apresentando descontinuidades bruscas e com alto ângulo, em concordância com a configuração tectônica das áreas em questão.

Higher derivative Chern-Simons extension in the noncommutative QED(3)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Disproportionate single-species contribution to canopy-soil nutrient flux in an Amazonian rainforest

Rainfall, throughfall and stemflow were monitored on an event basis in an undisturbed open tropical rainforest with a large number of palm trees located in the southwestern Amazon basin of Brazil. Stemflow samples were collected from 24 trees with a diameter at breast height (DBH) > 5 cm, as well as eight young and four full-grown babassu palms (Attalea speciosa Mart.) for 5 weeks during the peak of the wet season. We calculated rainfall, throughfall and stemflow concentrations and fluxes of Na+, K+, Ca2+, Mg2+,, Cl-, SO42-, NO3- and H+ and stemflow volume-weighted mean concentrations and fluxes for three size classes of broadleaf trees and three size classes of palms. The concentrations of most solutes were higher in stemflow than in rainfall and increased with increasing tree and palm size. Concentration enrichments from rainfall to stemflow and throughfall were particularly high (81-fold) for NO3-. Stemflow fluxes of NO3- and H+ exceeded throughfall fluxes but stemflow fluxes of other solutes were less than throughfall fluxes. Stemflow solute fluxes to the forest soil were dominated by fluxes on babassu palms, which represented only 4% of total stem number and 10% of total basal area. For NO3-, stemflow contributed 51% of the total mass of nitrogen delivered to the forest floor (stemflow + throughfall) and represented more than a 2000-fold increase in NO3- flux compared what would have been delivered by rainfall alone on the equivalent area. Because these highly localized fluxes of both water and NO3- persist in time and space, they have the potential to affect patterns of soil moisture, microbial populations and other features of soil biogeochemistry conducive to the creation of hotspots for nitrogen leaching and denitrification, which could amount to an important fraction of total ecosystem fluxes. Because these hotspots occur over very small areas, they have likely gone undetected in previous studies and need to be considered as an important feature of the biogeochemistry of palm-rich tropical forest. (C) 2011 Elsevier B.V. All rights reserved.

Factors that determine penumbral tissue loss in acute ischaemic stroke

The goal of acute stroke treatment with intravenous thrombolysis or endovascular recanalization techniques is to rescue the penumbral tissue. Therefore, knowing the factors that influence the loss of penumbral tissue is of major interest. In this study we aimed to identify factors that determine the evolution of the penumbra in patients with proximal (M1 or M2) middle cerebral artery occlusion. Among these factors collaterals as seen on angiography were of special interest. Forty-four patients were included in this analysis. They had all received endovascular therapy and at least minimal reperfusion was achieved. Their penumbra was assessed with perfusion- and diffusion-weighted imaging. Perfusion-weighted imaging volumes were defined by circular singular value decomposition deconvolution maps (Tmax > 6 s) and results were compared with volumes obtained with non-deconvolved maps (time to peak > 4 s). Loss of penumbral volume was defined as difference of post- minus pretreatment diffusion-weighted imaging volumes and calculated in per cent of pretreatment penumbral volume. Correlations between baseline characteristics, reperfusion, collaterals, time to reperfusion and penumbral volume loss were assessed using analysis of covariance. Collaterals (P = 0.021), reperfusion (P = 0.003) and their interaction (P = 0.031) independently influenced penumbral tissue loss, but not time from magnetic resonance (P = 0.254) or from symptom onset (P = 0.360) to reperfusion. Good collaterals markedly slowed down and reduced the penumbra loss: in patients with thrombolysis in cerebral infarction 2 b-3 reperfusion and without any haemorrhage, 27% of the penumbra was lost with 8.9 ml/h with grade 0 collaterals, whereas 11% with 3.4 ml/h were lost with grade 1 collaterals. With grade 2 collaterals the penumbral volume change was -2% with -1.5 ml/h, indicating an overall diffusion-weighted imaging lesion reversal. We conclude that collaterals and reperfusion are the main factors determining loss of penumbral tissue in patients with middle cerebral artery occlusions. Collaterals markedly reduce and slow down penumbra loss. In patients with good collaterals, time to successful reperfusion accounts only for a minor fraction of penumbra loss. These results support the hypothesis that good collaterals extend the time window for acute stroke treatment.

Advanced Noncontrast MR Imaging in Musculoskeletal Radiology

Multiple nonmorphologic magnetic resonance sequences are available in musculoskeletal imaging that can provide additional information to better characterize and diagnose musculoskeletal disorders and diseases. These sequences include blood-oxygen-level-dependent (BOLD), arterial spin labeling (ASL), diffusion-weighted imaging (DWI), and diffusion-tensor imaging (DTI). BOLD and ASL provide different methods to evaluate skeletal muscle microperfusion. The BOLD signal reflects the ratio between oxyhemoglobin and deoxyhemoglobin. ASL uses selective tagging of inflowing blood spins in a specific region for calculating local perfusion. DWI and DTI provide information about the structural integrity of soft tissue including muscles and fibers as well as pathologies.

Análisis bibliométrico de las publicaciones científicas argentinas en la categoría Agriculture, Multidisciplinary de la base de datos Web of Science (1997-2009)

El propósito del trabajo ha sido caracterizar el área de Agriculture, Multidisciplinary en Argentina, revisándose a nivel institucional, a través de la base de datos Web of Science, los trabajos realizados por investigadores en Instituciones argentinas y publicados en revistas internacionales con factor de impacto entre 1997 y 2009. En el contexto de América Latina, se han publicado 7795 trabajos de todos los tipos documentales y 7622 del tipo artículo o revisión en 49 revistas, y a nivel de Argentina se han encontrado 531 artículos o revisiones publicados en 31 revistas, la mayoría en inglés (80,23%), pero también en español (15,25%) y en portugués (4,33%). Por otro lado, se han analizado las Instituciones desde el punto de vista cuantitativo y cualitativo mediante diversos indicadores bibliométricos, como el Factor de Impacto Ponderado, el Factor de Impacto Relativo y la ratio número de citas frente a número de documentos, encontrándose que entre las instituciones más productivas destacan el Consejo Nacional de Investigaciones Científicas y Técnicas por el número de documentos y el Centro de Investigación y Desarrollo en Criotecnología de Alimentos por el Factor de Impacto Ponderado y por la ratio citas frente a documentos. Se observa una escasa colaboración internacional.

Radiocarbon ages of sediment core PG1414-2 from Beall Lake, Windmill Islands

A mid-Holocene climate optimum is inferred from a palaeosalinity reconstruction of a closed saline lake (Beall Lake) from the Windmill Islands, East Antarctica using an expanded diatom salinity weighted averaging (WA) regression and calibration model. The addition of 14 lakes and ponds from the Windmill Islands, East Antarctica, to an existing weighted averaging regression and calibration palaeosalinity model of 33 lakes from the Vestfold Hills, East Antarctica expands the number of taxa and lakes and the range of salinity in the existing model and improves the model's predictive ability. This improved model was used to infer Holocene changes in lake water salinity in Beall Lake, Windmill Islands. Six changes in diatom-inferred salinity in Beall Lake are put into broad chronological context based on three radiocarbon dates: as the East Antarctic Ice Sheet (EAIS) retreated from the Windmill Islands during the early Holocene (~9000-8130 corr. yr BP), Beall Lake formed as a melt water-fed freshwater lake, which gradually became more saline as marine influence increased from ~8000 corr. yr BP. Between ~8000 and 4800 corr. yr BP, the diatom assemblage included planktonic marine taxa such as Chaetoceros spp. and cryophilic taxa such as Fragilariopsis cylindrus, which indicate favourable summer growth conditions. A mid-Holocene warm period produced a climate that was warmer and more humid with increased precipitation and snow accumulation. This is reflected in the Beall Lake core as a reduction in the salinity of the lake diatom assemblage from ~4800-4600 corr. yr BP. Holocene isostatic uplift rates in the Windmill Islands vary from 5-6 m/1000 yr. By applying this uplift rate, it is calculated that the bedrock would have risen above sea level by ~4000 yr BP. The Beall Lake core diatom assemblage from ~4600-2900 corr. yr BP includes both marine cryophilic and planktonic taxa together with freshwater benthic and planktonic lacustrine taxa. This mix of species indicates the emergence of the lake from the sea around ~4600 corr. yr BP. From ~2800 corr. yr BP, retreat of the ice margin led to increasing melt water inputs and associated freshening of the lake basin until ~1900 corr. yr BP. The lake basin had no oceanic influence by this time, allowing a terrestrial freshwater flora to establish and thrive for the next ~1000 yr. At ~1850 corr. yr BP, a sudden and rapid salinity change is evident in Beall Lake. A late Holocene warm period between 2000 and 1000 yr BP has been observed in ice core records from Law Dome (an ice cap abutting the Windmill Islands to the east and north). It is therefore inferred that, at ~1850 corr. yr BP, summer temperatures within the Beall Lake catchment area were much higher than present summer temperatures. The climate optimum identified in the Beall Lake core ~4800 yr BP confirms mid-Holocene warming of the Windmill Islands and suggests a synchronous mid-Holocene climate optimum occurred across coastal East Antarctica. In addition, the abrupt climate change inferred at ~1850 yr BP suggests that higher resolution sampling of sediment cores from coastal East Antarctic limnological oases will provide more evidence of rapid climate change events over coastal East Antarctica in future.

Un modelo de encaminamiento en las redes móviles ad hoc con QoS

En la última década ha aumentado en gran medida el interés por las redes móviles Ad Hoc. La naturaleza dinámica y sin infraestructura de estas redes, exige un nuevo conjunto de algoritmos y estrategias para proporcionar un servicio de comunicación fiable extremo a extremo. En el contexto de las redes móviles Ad Hoc, el encaminamiento surge como una de las áreas más interesantes para transmitir información desde una fuente hasta un destino, con la calidad de servicio de extremo a extremo. Debido a las restricciones inherentes a las redes móviles, los modelos de encaminamiento tradicionales sobre los que se fundamentan las redes fijas, no son aplicables a las redes móviles Ad Hoc. Como resultado, el encaminamiento en redes móviles Ad Hoc ha gozado de una gran atención durante los últimos años. Esto ha llevado al acrecentamiento de numerosos protocolos de encaminamiento, tratando de cubrir con cada uno de ellos las necesidades de los diferentes tipos de escenarios. En consecuencia, se hace imprescindible estudiar el comportamiento de estos protocolos bajo configuraciones de red variadas, con el fin de ofrecer un mejor encaminamiento respecto a los existentes. El presente trabajo de investigación muestra precisamente una solución de encaminamiento en las redes móviles Ad Hoc. Dicha solución se basa en el mejoramiento de un algoritmo de agrupamiento y la creación de un modelo de encaminamiento; es decir, un modelo que involucra la optimización de un protocolo de enrutamiento apoyado de un mecanismo de agrupación. El algoritmo mejorado, denominado GMWCA (Group Management Weighted Clustering Algorithm) y basado en el WCA (Weighted Clustering Algorithm), permite calcular el mejor número y tamaño de grupos en la red. Con esta mejora se evitan constantes reagrupaciones y que los jefes de clústeres tengan más tiempo de vida intra-clúster y por ende una estabilidad en la comunicación inter-clúster. En la tesis se detallan las ventajas de nuestro algoritmo en relación a otras propuestas bajo WCA. El protocolo de enrutamiento Ad Hoc propuesto, denominado QoS Group Cluster Based Routing Protocol (QoSG-CBRP), utiliza como estrategia el empleo de clúster y jerarquías apoyada en el algoritmo de agrupamiento. Cada clúster tiene un jefe de clúster (JC), quien administra la información de enrutamiento y la envía al destino cuando esta fuera de su área de cobertura. Para evitar que haya constantes reagrupamientos y llamados al algoritmo de agrupamiento se consideró agregarle un jefe de cluster de soporte (JCS), el que asume las funciones del JC, siempre y cuando este haya roto el enlace con los otros nodos comunes del clúster por razones de alejamiento o por desgaste de batería. Matemáticamente y a nivel de algoritmo se han demostrado las mejoras del modelo propuesto, el cual ha involucrado el mejoramiento a nivel de algoritmo de clustering y del protocolo de enrutamiento. El protocolo QoSG-CBRP, se ha implementado en la herramienta de simulación Network Simulator 2 (NS2), con la finalidad de ser comparado con el protocolo de enrutamiento jerárquico Cluster Based Routing Protocol (CBRP) y con un protocolo de enrutamiento Ad Hoc reactivo denominado Ad Hoc On Demand Distance Vector Routing (AODV). Estos protocolos fueron elegidos por ser los que mejor comportamiento presentaron dentro de sus categorías. Además de ofrecer un panorama general de los actuales protocolos de encaminamiento en redes Ad Hoc, este proyecto presenta un procedimiento integral para el análisis de capacidades de la propuesta del nuevo protocolo con respecto a otros, sobre redes que tienen un alto número de nodos. Estas prestaciones se miden en base al concepto de eficiencia de encaminamiento bajo parámetros de calidad de servicio (QoS), permitiendo establecer el camino más corto posible entre un nodo origen y un nodo destino. Con ese fin se han realizado simulaciones con diversos escenarios para responder a los objetivos de la tesis. La conclusiones derivadas del análisis de los resultados permiten evaluar cualitativamente las capacidades que presenta el protocolo dentro del modelo propuesto, al mismo tiempo que avizora un atractivo panorama en líneas futuras de investigación. ABSTRACT In the past decade, the interest in mobile Ad Hoc networks has greatly increased. The dynamic nature of these networks without infrastructure requires a new set of algorithms and strategies to provide a reliable end-to-end communication service. In the context of mobile Ad Hoc networks, routing emerges as one of the most interesting areas for transmitting information from a source to a destination, with the quality of service from end-to-end. Due to the constraints of mobile networks, traditional routing models that are based on fixed networks are not applicable to Ad Hoc mobile networks. As a result, the routing in mobile Ad Hoc networks has experienced great attention in recent years. This has led to the enhancement of many routing protocols, trying to cover with each one of them, the needs of different types of scenarios. Consequently, it is essential to study the behavior of these protocols under various network configurations, in order to provide a better routing scheme. Precisely, the present research shows a routing solution in mobile Ad Hoc networks. This solution is based on the improvement of a clustering algorithm, and the creation of a routing model, ie a model that involves optimizing a routing protocol with the support of a grouping mechanism. The improved algorithm called GMWCA (Group Management Weighted Clustering Algorithm) and based on the WCA (Weighted Clustering Algorithm), allows to calculate the best number and size of groups in the network. With this enhancement, constant regroupings are prevented and cluster heads are living longer intra-cluster lives and therefore stability in inter-cluster communication. The thesis details the advantages of our algorithm in relation to other proposals under WCA. The Ad Hoc routing protocol proposed, called QoS Group Cluster Based Routing Protocol (QoSG-CBRP), uses a cluster-employment strategy and hierarchies supported by the clustering algorithm. Each cluster has a cluster head (JC), who manages the routing information and sends it to the destination when is out of your coverage area. To avoid constant rearrangements and clustering algorithm calls, adding a support cluster head (JCS) was considered. The JCS assumes the role of the JC as long as JC has broken the link with the other nodes in the cluster for common restraining reasons or battery wear. Mathematically and at an algorithm level, the improvements of the proposed model have been showed, this has involved the improvement level clustering algorithm and the routing protocol. QoSG-CBRP protocol has been implemented in the simulation tool Network Simulator 2 (NS2), in order to be compared with the hierarchical routing protocol Cluster Based Routing Protocol (CBRP) and with the reactive routing protocol Ad Hoc On Demand Distance Vector Routing (AODV). These protocols were chosen because they showed the best individual performance in their categories. In addition to providing an overview of existing routing protocols in Ad Hoc networks, this project presents a comprehensive procedure for capacity analysis of the proposed new protocol with respect to others on networks that have a high number of nodes. These benefits are measured based on the concept of routing efficiency under the quality of service (QoS) parameters, thus allowing for the shortest possible path between a source node and a destination node. To meet the objectives of the thesis, simulations have been performed with different scenarios. The conclusions derived from the analysis of the results to assess qualitatively the protocol capabilities presented in the proposed model, while an attractive scenario for future research appears.

Percepciones sobre tres técnicas de evaluación de código: un estudio empírico sobre la intuición y las opiniones de los encargados de las pruebas de software

La Ingeniería del Software Empírico (ISE) utiliza como herramientas los estudios empíricos para conseguir evidencias que ayuden a conocer bajo qué circunstancias es mejor usar una tecnología software en lugar de otra. La investigación en la que se enmarca este TFM explora si las intuiciones y/o preferencias de las personas que realizan las pruebas de software, son capaces de predecir la efectividad de tres técnicas de evaluación de código: lectura por abstracciones sucesivas, cobertura de decisión y partición en clases de equivalencia. Para conseguir dicho objetivo, se analizan los datos recogidos en un estudio empírico, realizado por las tutoras de este TFM. En el estudio empírico distintos sujetos aplican las tres técnicas de evaluación de código a tres programas distintos, a los que se les habían introducido una serie de faltas artificialmente. Los sujetos deben reportar los fallos encontrados en los programas, así como, contestar a una serie de preguntas sobre sus intuiciones y preferencias. A la hora de analizar los datos del estudio, se ha comprobado: 1) cuáles son sus intuiciones y preferencias (mediante el test estadístico X2 de Pearson); 2) si los sujetos cambian de opinión después de aplicar las técnicas (para ello se ha utilizado índice de Kappa, el Test de McNemar-Bowker y el Test de Stuart-Maxwell); 3) la consistencia de las distintas preguntas (mediante el índice de Kappa), comparando: intuiciones con intuiciones, preferencias con preferencias e intuiciones con preferencias; 4) Por último, si hay coincidencia entre las intuiciones y preferencias con la efectividad real obtenida (para ello se ha utilizado, el Modelo Lineal General con medidas repetidas). Los resultados muestran que, no hay una intuición clara ni tampoco una preferencia concreta, con respecto a los programas. Además aunque existen cambios de opinión después de aplicar las técnicas, no se encuentran evidencias claras para afirmar que la intuición y preferencias influyen en su efectividad. Finalmente, existen relaciones entre las intuiciones con intuiciones, preferencias con preferencias e intuiciones con preferencias, además esta relación es más notoria después de aplicar las técnicas. ----ABSTRACT----Empirical Software Engineering (ESE) uses empirical studies as a mean to generate evidences to help determine under what circumstances it is convenient to use a given software technology. This Master Thesis is part of a research that explores whether intuitions and/or preferences of testers, can be used to predict the effectiveness of three code evaluation techniques: reading by stepwise abstractions, decision coverage and equivalence partitioning. To achieve this goal, this Master Thesis analyzes the data collected in an empirical study run by the tutors. In the empirical study, different subjects apply three code evaluation techniques to three different programs. A series of faults were artificially introduced to the programs. Subjects are required to report the defects found in the programs, as well as answer a series of questions about their intuitions and preferences. The data analyses test: 1) what are the intuitions and preferences of the subjects (using the Pearson X2 test); 2) whether subjects change their minds after applying the techniques (using the Kappa coefficient, McNemar-Bowker test, and Stuart-Maxwell test); 3) the consistency of the different questions, comparing: intuitions versus intuitions, preferences versus preferences and preferences versus intuitions (using the Kappa coefficient); 4) finally, if intuitions and/or preferences predict the actual effectiveness obtained (using the General Linear Model, repeated measures). The results show that there is not clear intuition or particular preference with respect to the programs. Moreover, although there are changes of mind after applying the techniques, there are not clear evidences to claim that intuition and preferences influence their effectiveness. Finally, there is a relationship between the intuitions versus intuitions, preferences versus preferences and intuitions versus preferences; this relationship is more noticeable after applying the techniques.