999 resultados para Animal Structures


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O objetivo deste trabalho foi identificar a aptidão de genótipos de batata-doce (Ipomoea batatas) para consumo humano, produção de etanol e alimentação animal, por meio de índices de aptidão. Os índices de aptidão corresponderam às médias dos valores das variáveis padronizadas para 16 características de interesse, ponderadas por pesos atribuídos a cada característica, conforme a aptidão avaliada. Utilizou-se o delineamento experimental de blocos ao acaso, com duas repetições e 39 genótipos: 36 acessos da coleção de germoplasma da Universidade Federal de Lavras e três cultivares comerciais (Palmas, Brazlândia-Branca e Brazlândia-Rosada). Oito genótipos foram considerados aptos à produção de etanol, 11 à alimentação animal e 11 ao consumo humano, incluindo as cultivares Palmas e Brazlândia-Branca. Os acessos UFLA07-12, UFLA07-31, UFLA07-43, UFLA07-49 e UFLA07-53 apresentaram aptidão para produção de etanol, alimentação animal e consumo humano. O índice de seleção é eficiente para estabelecer aptidões para genótipos de batata-doce.

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The geologic structures and metamorphic zonation of the northwestern Indian Himalaya contrast significantly with those in the central and eastern parts of the range, where the high-grade metamorphic rocks of the High Himalayan Crystalline (HHC) thrust southward over the weakly metamorphosed sediments of the Lesser Himalaya along the Main Central Thrust (MCT). Indeed, the hanging wall of the MCT in the NW Himalaya mainly consists of the greenschist facies metasediments of the Chamba zone, whereas HHC high-grade rocks are exposed more internally in the range as a large-scale dome called the Gianbul dome. This Gianbul dome is bounded by two oppositely directed shear zones, the NE-dipping Zanskar Shear Zone (ZSZ) on the northern flank and the SW-dipping Miyar Shear Zone (MSZ) on the southern limb. Current models for the emplacement of the HHC in NW India as a dome structure differ mainly in terms of the roles played by both the ZSZ and the MSZ during the tectonothermal evolution of the HHC. In both the channel flow model and wedge extrusion model, the ZSZ acts as a backstop normal fault along which the high-grade metamorphic rocks of the HHC of Zanskar are exhumed. In contrast, the recently proposed tectonic wedging model argues that the ZSZ and the MSZ correspond to one single detachment system that operates as a subhorizontal backthrust off of the MCT. Thus, the kinematic evolution of the two shear zones, the ZSZ and the MSZ, and their structural, metamorphic and chronological relations appear to be diagnostic features for discriminating the different models. In this paper, structural, metamorphic and geochronological data demonstrate that the MSZ and the ZSZ experienced two distinct kinematic evolutions. As such, the data presented in this paper rule out the hypothesis that the MSZ and the ZSZ constitute one single detachment system, as postulated by the tectonic wedging model. Structural, metamorphic and geochronological data are used to present an alternative tectonic model for the large-scale doming in the NW Indian Himalaya involving early NE-directed tectonics, weakness in the upper crust, reduced erosion at the orogenic front and rapid exhumation along both the ZSZ and the MSZ.

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We present a seabed profile estimation and following method for close proximity inspection of 3D underwater structures using autonomous underwater vehicles (AUVs). The presented method is used to determine a path allowing the AUV to pass its sensors over all points of the target structure, which is known as coverage path planning. Our profile following method goes beyond traditional seabed following at a safe altitude and exploits hovering capabilities of recent AUV developments. A range sonar is used to incrementally construct a local probabilistic map representation of the environment and estimates of the local profile are obtained via linear regression. Two behavior-based controllers use these estimates to perform horizontal and vertical profile following. We build upon these tools to address coverage path planning for 3D underwater structures using a (potentially inaccurate) prior map and following cross-section profiles of the target structure. The feasibility of the proposed method is demonstrated using the GIRONA 500 AUV both in simulation using synthetic and real-world bathymetric data and in pool trials

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Aquest treball proposa un estudi del recull de contes de Jordi Puntí, Animals tristos, des d'una directriu bàsica: el plantejament teòric sobre la fragilitat dels vincles humans de la postmodernitat postulat pel sociòleg Zygmunt Bauman en la seva obra Amor líquido. Acerca de la fragilidad de los vínculos humanos. Així, l'objectiu de l'estudi és demostrar que els personatges d'Animals tristos són un reflex de la societat urbana actual i de la naturalesa canviant en les relacions de parella de principis del s. XXI que descriu Bauman. D'aquesta forma, l'anàlisi de l'obra de Puntí, especialment dels seus personatges, és realitzada a través d'un marc teòric de naturalesa sociològica.

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The objective of this work was to develop an alternative methodology to study and characterize the phosphate crystalline properties, directly associated with solubility and plant availability, in biochar from swine bones. Some phosphate symmetry properties of pyrolyzed swine bones were established, using solid state nuclear magnetic resonance spectroscopy, principal component analysis, and multivariate curve resolution analysis, on four pyrolyzed samples at different carbonization intensities. Increasing carbonization parameters (temperature or residence time) generates diverse phosphate structures, increasing their symmetry and decreasing the crossed polarizability of the pair ¹H-31P, producing phosphates with, probably, lower solubility than the ones produced at lower carbonization intensity. Additionally, a new methodology is being developed to study and characterize phosphate crystalline properties directly associated with phosphate solubility and availability to plants.

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ABSTRACT Adult neuronal plasticity is a term that corresponds to a set of biological mechanisms allowing a neuronal circuit to respond and adapt to modifications of the received inputs. Mystacial whiskers of the mouse are the starting point of a major sensory pathway that provides the animal with information from its immediate environment. Through whisking, information is gathered that allows the animal to orientate itself and to recognize objects. This sensory system is crucial for nocturnal behaviour during which vision is not of much use. Sensory information of the whiskers are sent via brainstem and thalamus to the primary somatosensory area (S1) of the cerebral cortex in a strictly topological manner. Cell bodies in the layer N of S 1 are arranged in ring forming structures called barrels. As such, each barrel corresponds to the cortical representation in layer IV of a single whisker follicle. This histological feature allows to identify with uttermost precision the part of the cortex devoted to a given whisker and to study modifications induced by different experimental conditions. The condition used in the studies of my thesis is the passive stimulation of one whisker in the adult mouse for a period of 24 hours. It is performed by glueing a piece of metal on one whisker and placing the awake animal in a cage surrounded by an electromagnetic coil that generates magnetic field burst inducing whisker movement at a given frequency during 24 hours. I analysed the ultrastructure of the barrel corresponding the stimulated whisker using serial sections electron microscopy and computer-based three-dimensional reconstructions; analysis of neighbouring, unstimulated barrels as well as those from unstimulated mice served as control. The following elements were structurally analyzed: the spiny dendrites, the axons of excitatory as well as inhibitory cells, their connections via synapses and the astrocytic processes. The density of synapses and spines is upregulated in a barrel corresponding to a stimulated whisker. This upregulation is absent in the BDNF heterozygote mice, indicating that a certain level of activity-dependent released BDNF is required for synaptogenesis in the adult cerebral cortex. Synpaptogenesis is correlated with a modification of the astrocytes that place themselves in closer vicinity of the excitatory synapses on spines. Biochemical analysis revealed that the astrocytes upregulate the expression of transporters by which they internalise glutamate, the neurotransmitter responsible for the excitatory response of cortical neurons. In the final part of my thesis, I show that synaptogenesis in the stimulated barrel is due to the increase in the size of excitatory axonal boutons that become more frequently multisynaptic, whereas the inhibitory axons do not change their morphology but form more synapses with spines apposed to them. Taken together, my thesis demonstrates that all the cellular elements present in the neuronal tissue of the adult brain contribute to activity-dependent cortical plasticity and form part of a mechanism by which the animal responds to a modified sensory experience. Throughout life, the neuronal circuit keeps the faculty to adapt its function. These adaptations are partially transitory but some aspects remain and could be the structural basis of a memory trace in the cortical circuit. RESUME La plasticité neuronale chez l'adulte désigne un ensemble de mécanismes biologiques qui permettent aux circuits neuronaux de répondre et de s'adapter aux modifications des stimulations reçues. Les vibrisses des souris sont un système crucial fournissant des informations sensorielles au sujet de l'environnement de l'animal. L'information sensorielle collectée par les vibrisses est envoyée via le tronc cérébral et le thalamus à l'aire sensorielle primaire (S 1) du cortex cérébral en respectant strictement la somatotopie. Les corps cellulaires dans la couche IV de S 1 sont organisés en anneaux délimitant des structures nommées tonneaux. Chaque tonneau reçoit l'information d'une seule vibrisse et l'arrangement des tonneaux dans le cortex correspond à l'arrangement des vibrisses sur le museau de la souris. Cette particularité histologique permet de sélectionner avec certitude la partie du cortex dévolue à une vibrisse et de l'étudier dans diverses conditions. Le paradigme expérimental utilisé dans cette thèse est la stimulation passive d'une seule vibrisse durant 24 heures. Pour ce faire, un petit morceau de métal est collé sur une vibrisse et la souris est placée dans une cage entourée d'une bobine électromagnétique générant un champ qui fait vibrer le morceau de métal durant 24 heures. Nous analysons l'ultrastructure du cortex cérébral à l'aide de la microscopie électronique et des coupes sériées permettant la reconstruction tridimensionnelle à l'aide de logiciels informatiques. Nous observons les modifications des structures présentes : les dendrites épineuses, les axones des cellules excitatrices et inhibitrices, leurs connections par des synapses et les astrocytes. Le nombre de synapses et d'épines est augmenté dans un tonneau correspondant à une vibrisse stimulée 24 heures. Basé sur cela, nous montrons dans ces travaux que cette réponse n'est pas observée dans des souris hétérozygotes BDNF+/-. Cette neurotrophine sécrétée en fonction de l'activité neuronale est donc nécessaire pour la synaptogenèse. La synaptogenèse est accompagnée d'une modification des astrocytes qui se rapprochent des synapses excitatrices au niveau des épines dendritiques. Ils expriment également plus de transporteurs chargés d'internaliser le glutamate, le neurotransmetteur responsable de la réponse excitatrice des neurones. Nous montrons aussi que les axones excitateurs deviennent plus larges et forment plus de boutons multi-synaptiques à la suite de la stimulation tandis que les axones inhibiteurs ne changent pas de morphologie mais forment plus de synapses avec des épines apposées à leur membrane. Tous les éléments analysés dans le cerveau adulte ont maintenu la capacité de réagir aux modifications de l'activité neuronale et répondent aux modifications de l'activité permettant une constante adaptation à de nouveaux environnements durant la vie. Les circuits neuronaux gardent la capacité de créer de nouvelles synapses. Ces adaptations peuvent être des réponses transitoires aux stimuli mais peuvent aussi laisser une trace mnésique dans les circuits.

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Structures built by animals are a widespread and ecologically important 'extended phenotype'. While its taxonomic diversity has been well described, factors affecting short-term evolution of building behavior within a species have received little experimental attention. Here we describe how, given the opportunity, wandering Drosophila melanogaster larvae often build long tunnels in agar substrates and embed their pupae within them. These embedded larvae are characterized by a longer egg-to-pupariation developmental time than larvae that pupate on the surface. Assuming that such building behaviors are likely to be energetically costly and/or time consuming, we hypothesized that they should evolve to be less pronounced under resource or time limitation. In accord with this prediction, larvae from populations evolved for 160 generations under a regime that combines larval malnutrition with limited developmental time dug shorter tunnels than larvae from control unselected populations. However, the proportion of larvae that embedded before pupation did not differ between the malnutrition-adapted and control populations, suggesting that tunnel length and likelihood of embedding before pupation are controlled by different genetic loci. The behaviors exhibited by wandering larvae of Drosophila melanogaster prior to pupation offer a model system to study evolution of animal building behaviors because the tunneling and embedding phenotypes are simple, facultative and highly variable.

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O objetivo deste trabalho foi avaliar o valor nutritivo, a estrutura do dossel e a produção animal de novilhos em pastos de capim-piatã (Urochloa brizantha, cultivar Piatã), manejados a 15, 30 e 45 cm de altura, sob lotação contínua. Utilizou-se o delineamento experimental de blocos ao acaso, com duas repetições e três alturas. As alturas dos pastos foram monitoradas duas vezes por semana, e as taxas de lotação ajustadas. Mensalmente, os pastos foram amostrados e os animais foram pesados. Não houve diferença no valor nutritivo dos pastos manejados com diferentes alturas. Os ganhos médios diários de 650 g por novilho foram semelhantes entre as diferentes alturas de manejo. A taxa de lotação foi menor para o pasto com 45 cm (2,4 UA ha-1), intermediária para o de 30 cm (3,1 UA ha-1) e maior para o manejado com 15 cm (3,8 UA ha-1), o que resultou em maior ganho por área dos pastos manejados com 15 cm (1.050 kg ha-1) e 30 cm (910 kg ha-1) de altura, quando comparados ao manejado a 45 cm (635 kg ha-1). O capim-piatã apresenta grande flexibilidade de manejo sob lotação contínua e pode ser manejado entre 15 e 45 cm de altura.

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El objetivo de esta investigación fue evaluar los coeficientes de digestibilidad aparente de materia seca (MS), proteína y energía de alimentos de origen animal y vegetal, utilizados en raciones para cachama (Piaractus brachypomus). Fueron formuladas 15 dietas experimentales, compuestas por 69,5% de una dieta referencia semipurificada, 0,5% de óxido de cromo y 30% del ingrediente a evaluar. En cada experimento, fueron utilizados 90 peces que se alimentaron durante cinco días con la correspondiente dieta; al quinto día, los animales fueron trasladados a tanques cónicos para recolección de heces. Los coeficientes de digestibilidad aparente (CDA) de proteína variaron de 92,1 a 84,7% entre los ingredientes proteicos de origen vegetal, de 85,0 a 68,5% en los proteicos de origen animal, y de 83,7 a 57,6% entre los de origen vegetal con baja proteína. Los CDA de energía de torta de soya, gluten de maíz, harina de yuca integral y de todos los ingredientes de origen animal arrojaron valores superiores a 76%. Los máximos CDA de MS variaron entre 71 y 78% y fueron observados en gluten, harina de yuca y en los ingredientes de origen animal. La cachama tiene alta capacidad para aprovechar eficientemente ingredientes de origen animal y vegetal.

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O objetivo deste trabalho foi avaliar o acúmulo de forragem, a estrutura do dossel, o valor nutritivo, o consumo de forragem e a produção animal, em pastos de Urochloa humidicola sob lotação contínua. As cultivares BRS Tupi e Comum foram avaliadas durante os períodos de seca e das águas (julho de 2011 a agosto de 2012), em delineamento experimental de blocos ao acaso, com dois tratamentos e seis repetições. Mensalmente, os animais foram pesados e os pastos amostrados para a determinação de: taxa de acúmulo de forragem (TAF); massa de forragem; percentagens de folha (PF), colmo e material morto (PM); e valor nutritivo. O consumo de matéria seca (CMS) foi determinado uma vez a cada período. 'BRS Tupi' apresentou maiores TAF e PF e menor PM do que a 'Comum', durante o período das águas. O valor nutritivo, o CMS e o ganho médio diário foram semelhantes entre as duas cultivares. O conteúdo de proteína bruta da forragem - 6,0 e 5,0%, respectivamente, para os períodos das águas e seco - foi o principal fator limitante ao CMS. 'BRS Tupi' recebeu maior taxa de lotação e, consequentemente, possibilitou maior ganho de peso vivo por área (192 kg ha-1 por ano) do que a 'Comum' (126 kg ha-1 por ano). A 'BRS Tupi' é uma boa alternativa para a diversificação de pastagens em solos de baixa fertilidade sujeitos a alagamento temporário.

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Reconstruction of defects in the craniomaxillofacial (CMF) area has mainly been based on bone grafts or metallic fixing plates and screws. Particularly in the case of large calvarial and/or craniofacial defects caused by trauma, tumours or congenital malformations, there is a need for reliable reconstruction biomaterials, because bone grafts or metallic fixing systems do not completely fulfill the criteria for the best possible reconstruction methods in these complicated cases. In this series of studies, the usability of fibre-reinforced composite (FRC) was studied as a biostable, nonmetallic alternative material for reconstructing artificially created bone defects in frontal and calvarial areas of rabbits. The experimental part of this work describes the different stages of the product development process from the first in vitro tests with resin-impregnated fibrereinforced composites to the in vivo animal studies, in which this FRC was tested as an implant material for reconstructing different size bone defects in rabbit frontal and calvarial areas. In the first in vitro study, the FRC was polymerised in contact with bone or blood in the laboratory. The polymerised FRC samples were then incubated in water, which was analysed for residual monomer content by using high performance liquid chromatography (HPLC). It was found that this in vitro polymerisation in contact with bone and blood did not markedly increase the residual monomer leaching from the FRC. In the second in vitro study, different adhesive systems were tested in fixing the implant to bone surface. This was done to find an alternative implant fixing system to screws and pins. On the basis of this study, it was found that the surface of the calvarial bone needed both mechanical and chemical treatments before the resinimpregnated FRC could be properly fixed onto it. In three animal studies performed with rabbit frontal bone defects and critical size calvarial bone defect models, biological responses to the FRC implants were evaluated. On the basis of theseevaluations, it can be concluded that the FRC, based on E-glass (electrical glass) fibres forming a porous fibre veil enables the ingrowth of connective tissues to the inner structures of the material, as well as the bone formation and mineralization inside the fibre veil. Bone formation could be enhanced by using bioactive glass granules fixed to the FRC implants. FRC-implanted bone defects healed partly; no total healing of defects was achieved. Biological responses during the follow-up time, at a maximum of 12 weeks, to resin-impregnated composite implant seemed to depend on the polymerization time of the resin matrix of the FRC. Both of the studied resin systems used in the FRC were photopolymerised and the heat-induced postpolymerisation was used additionally.

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This work describes a simulation tool being developed at UPC to predict the microwave nonlinear behavior of planar superconducting structures with very few restrictions on the geometry of the planar layout. The software is intended to be applicable to most structures used in planar HTS circuits, including line, patch, and quasi-lumped microstrip resonators. The tool combines Method of Moments (MoM) algorithms for general electromagnetic simulation with Harmonic Balance algorithms to take into account the nonlinearities in the HTS material. The Method of Moments code is based on discretization of the Electric Field Integral Equation in Rao, Wilton and Glisson Basis Functions. The multilayer dyadic Green's function is used with Sommerfeld integral formulation. The Harmonic Balance algorithm has been adapted to this application where the nonlinearity is distributed and where compatibility with the MoM algorithm is required. Tests of the algorithm in TM010 disk resonators agree with closed-form equations for both the fundamental and third-order intermodulation currents. Simulations of hairpin resonators show good qualitative agreement with previously published results, but it is found that a finer meshing would be necessary to get correct quantitative results. Possible improvements are suggested.

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Resumo: O objetivo deste trabalho foi propor modelos que considerem estrutura irregular dos dados e avaliá-los em relação a modelos utilizados com tempos regulares. Foram considerados os modelos de crescimento Gompertz, Logístico e Von Bertalanffy com estruturas regular e irregular para os erros. A metodologia foi exemplificada com o uso de dados reais e simulados. Foram utilizados 16 pesos médios de 160 animais da raça Hereford, com pesagens do nascimento até aproximadamente 2 anos de idade. Para cada modelo, os parâmetros do melhor ajuste foram utilizados para simulação. O ajuste dos modelos melhora quando a estrutura original dos dados é levada em consideração, com redução na soma de quadrados dos resíduos e no valor do critério de Akaike.