1,355 research outputs found
Recommended from our members
Agency and Reasons in Epistemology
Ever since John Locke, philosophers have discussed the possibility of a normative epistemology: are there epistemic obligations binding the cognitive economy of belief and disbelief? Locke\u27s influential answer was evidentialist: we have an epistemic obligation to believe in accordance with our evidence. In this dissertation, I place the contemporary literature on agency and reasons at the service of some such normative epistemology. I discuss the semantics of obligations, the connection between obligations and reasons to believe, the implausibility of Lockean evidentialism, and some of the alleged connections between agency and justification
Phase Diversity For Speckle Reduction
B-mode ultrasound images are characterised by speckle artefact, which results from interference effects between returning echoes, and may make the interpretation of images difficult. Consequently, many methods have been developed to reduce this problematic feature. One widely used method, popular in both medical and non-destructive-testing applications, is a 1D method known as Split Spectrum Processing (SSP), or also as Frequency Diversity. Alhough this method was designed for speckle reduction applications, the final image experiences a resultant loss of resolution, impinging a trade-off between speckle reduction and resolution loss. In order to overcome this problem, we have developed a new method that is an extension of SSP to 2D data using directive filters, called Split Phase Processing (SPP). Instead of using ID narrow band-pass filters as in the SSP method, we use 2D directive filters to split the RF ultrasound image in a set of wide band images with different phases. The use of such filters substantially avoids the resolution loss usually associated with SSP for speckle reduction, because they effectively have the same bandwidth as the original image. It is concluded that the Split Phase Processing, as introduced here, provides a significant improvement over the conventional Split Spectrum Processing.5035414422Burckhardt, C.B., Speckle in ultrasound b-mode scans (1978) IEEE Trans. Sonics and Ultrasonics, 25 (1), pp. 1-6. , JanuaryChen, Y., Yin, R., Hynn, P., Broschat, S., Aggressive region growing for speckle reduction in ultrasound images (2003) Pattern Recognition Letters, 24 (4-5), pp. 677-691. , FebruaryGehlbach, S.M., (1983) Pulse Reflection Imaging and Acoustic Speckle, , Ph.D. dissertation, Stanford UniversityHealey, A.J., Leeman, S., Ferrari, L.A., Removing the ambiguity from single image speckle reduction techniques (1996) Acoustical Imaging, 22, pp. 145-150Li, P.C., Odonnell, M., Evaluational spatial compounding (1994) Ultrasonic Imaging, 16 (3), pp. 176-189Shankar, P.M., Newhouse, V.L., Speckle reduction with improved resolution in ultrasound images (1985) IEEE Trans. Sonics and Ultrasonics, 32 (4), pp. 537-543. , Jul
Strain and slackness of achilles tendon during passive joint mobilization via imaging ultrasonography
Background: In vivo study of the mechanical behavior of tendons may bring advances in evaluating the impact of intervention programs for flexibility and strength, in clinical practice and sports. Objective: The aim of this study was to quantify the relative strain and slackness of achilles tendons during passive mobilization, for four ankle joint angles and two knee angles. Methods: The displacement of the muscle-tendon junction was quantified by means of ultrasound images acquired during passive ankle mobilization, with the aid of an electrogoniometer and an electromyograph to ensure the achievement of the required angles and muscle inactivity, respectively. Results: The strain values ranged from 4.28%±2.37 to -0.94%±1.58 for the fully extended knee, and from 2.38%±1.63 to -2.32%±2.16% for the flexed knee. Conclusions: The values found in this study confirm those in the literature and demonstrate how the Achilles tendon participates in length changes in the muscle-tendon unit during passive movement. These results suggest that the mechanical properties of tendinous tissues affect the relationship between the length of muscle fibers and the joint angle, even during this type of movement
'Just Little Things': Nurses' perceptions of quality of life for people with severe multiple impairments.
ABSTRACT Notions of quality of life dictate philosophies and policies for services for people with developmental disabilities. There is an abundance of research on quality of life, much of which has influenced the significant amount of study of quality of life for people with developmental disabilities. According to specialist developmental disability nurses, however, this research has little meaning for one group of people with developmental disabilities with whom they work - people with severe multiple impairments. Nevertheless, judgements and decisions about the lives of this group continue to be driven by the idea of quality of life. While the literature review found that researchers are urged to seek the perceptions of people regarding their own quality of life by asking them, some authors have noted the difficulty in pursuing such a method with people, such as people with severe multiple impairments, who are unable to communicate in the usual ways. Given, then, that it is difficult to directly determine the views of people with severe multiple impairments, this study sought the perceptions of nurses about the quality of life of the people with whom they work. In order to discover and conceptualise nurses' views, a symbolic interaction perspective was chosen to guide this study and data were analysed using the grounded theory approach. The study was conducted in two stages. Stage One consisted of semi-structured indepth interviews with expert nurses to explore their perceptions of quality of life for the people with whom they worked. A significant finding in these interviews was that perceptions of quality of life are mediated by interaction. Consequently, Stage Two involved a participant observation study in which the interactions of nurses and people with severe multiple impairments were examined. Specialist developmental disability nurses have a unique view of quality of life for people with severe multiple impairments. They refer to it as 'just little things', a phrase which masks complex nursing knowledge and skills, and which can be described by four interrelated categories which emerged from the data: humans being, supporting, becoming intimate, and situated belonging. As nurses become more intimate with individuals, they perceive that people with severe multiple impairments are humans being as they wish, and that quality resides in supporting their everyday lives in a context of situated belonging. This thesis represents a new conceptualisation of quality of life for people with severe multiple impairments, a conceptualisation which may have significance for other groups and, indeed, for the whole quality of life enterprise. This conceptualisation draws on knowledge not usually related to quality of life, that is, knowledge of the body, of the emotions, of identity and of humanness. Such findings demonstrate the power of an interpretive approach in explicating the meanings nurses have regarding quality of life. Further, these findings have implications for how the question of quality of life is approached, for how different ways of thinking about people impact on quality of life, and for the importance of the life in quality of life
Histology of the skin of the blanca serrana goat bred in different production systems
Este trabajo tuvo como objetivo caracterizar la piel de caprinos de raza Blanca Serrana Andaluza, criados en sistemas de producción intensivo y extensivo. Fueron sacrificados 31 animales de la raza Blanca Serrana Andaluza (16 en extensivo y 15 en intensivo) con 20 kg de peso vivo. Se encontraron diferencias significativas (p0,05) entre los dos sistemas de producción analizados. Las caracterÃsticas de la piel de los chivos revelaron pieles de primera calida
Integridade estrutural de compósitos laminados em fibra de carbono sujeitos a diferentes taxas de desgaste e absorção de água : protótipo de máquina de testes
Trabalho final de mestrado para obtenção do grau de Mestre em Engenharia MecânicaDesde sempre no panorama do ciclismo de alta competição se fizeram todos os esforços para melhorar os resultados dos atletas. Grande parte destes trabalhos está no desenvolvimento das bicicletas e seus componentes. A empresa Morphis Composites que está em fase de desenvolvimento de carretos de desviador em fibra de carbono. Estando estes componentes em material compósito laminado expostos à atmosfera, poderá estar em causa a sua integridade estrutural pois sabe-se que irão absorver água por difusão e se vão desgastar de forma diferente de carretos de outros materiais. Tudo isto poderá levar ao aumento do seu atrito na transmissão, sendo que é necessária a criação de meios para a avaliação desta temática.
No presente trabalho faz-se o projecto e construção de um protótipo para medição de atrito em transmissões de bicicleta. Inclui-se uma breve pesquisa bibliográfica sobre correntes de rolos industriais e de ciclismo, o seu funcionamento e mecanismos de atrito. Além disto fez-se também uma breve pesquisa sobre os efeitos da absorção de água na fibra de carbono. Para o dimensionamento do sistema de medição procuraram-se resultados de trabalhos similares de forma a aferir as grandezas a medir e a sensibilidade necessária.
O protótipo deve medir a potência conduzida à transmissão para esta rodar em vazio a uma velocidade constante que foi fixada neste caso em 60 rpm, sendo que quanto mais baixa a potencia medida menor o atrito da transmissão. O sensor usado é uma roseta colada a +45 e -45 graus no veio que fornece movimento ao sistema. O sinal é retirado do veio em rotação através de um sistema de anéis deslizantes em bronze onde se usaram escovas de grafite e de filamentos de cobre.
Após a construção do protótipo fez-se a calibração estática dos sistemas de medição com bons resultados de sensibilidade e repetibilidade. Estes resultados empÃricos também foram comparados com os resultados teóricos não tendo havido discrepâncias relevantes, provando a qualidade das medições de binário obtidas pelos extensómetros. No entanto, devido ao ruÃdo introduzido no sinal pelas escovas em movimento, não foi possÃvel obter resultados de qualidade nos ensaios dinâmicos para a potência e atrito na transmissão em rotação com o presente protótipo. No final apresentam-se sugestões para melhoria em trabalhos futuros.Ever since the beginning of high competition in cycling, that every erffort has been made to improve the results of the athletes. Much of this work is in the development of bicycles and their components. The company Morphis Composites is in the development stage of carbon fiber rear derailleur sprockets. These components made of laminated composite material are exposed to the atmosphere, thus their structural integrity may be affected because it is known that they will absorb water by diffusion and will wear differently from sprockets made of other materials, such as metals. All this can lead to the increase of its friction in the transmission, and it is necessary to create means for the evaluation of this situation.
In the present work, the design and construction of a prototype for measuring friction in bicycle transmissions is done. A brief literature review on industrial roller and cycling chains, their operation and friction mechanisms is included. In addition, a brief research was also made on the effects of water absorption on carbon fiber. For the sizing of the measurement system, results of similar work were sought in order to understand the quantities to be measured and the required sensitivity.
The prototype shall measure the power delivered to the transmission to idle at a constant speed which has been set at 60 rpm in this case, the lower the measured power the lower the transmission friction. The sensor used is a rosette glued to +45 and -45 degrees in a section of the main shaft before the main sprocket. The signal is drawn from the rotating shaft through a bronze slip ring system where graphite brushes and copper filaments were used.
Upon prototype building the static calibration of the measurement systems was made with good results of sensitivity and repeatability. These empirical results were also compared with what would theoretically be expected and there were no relevant discrepancies, proving the quality of the torque measurements obtained by the extensometers. However, due to the noise introduced into the signal by the moving brushes, it was not possible to obtain quality results in the dynamic tests for power and friction in the rotational transmission with the present prototype. At the end, suggestions are presented for improvement in future work.N/
Thermal Density Functional Theory in Context
This chapter introduces thermal density functional theory, starting from the
ground-state theory and assuming a background in quantum mechanics and
statistical mechanics. We review the foundations of density functional theory
(DFT) by illustrating some of its key reformulations. The basics of DFT for
thermal ensembles are explained in this context, as are tools useful for
analysis and development of approximations. We close by discussing some key
ideas relating thermal DFT and the ground state. This review emphasizes thermal
DFT's strengths as a consistent and general framework.Comment: Submitted to Spring Verlag as chapter in "Computational Challenges in
Warm Dense Matter", F. Graziani et al. ed
Dermatophylosis in Santa Inês sheep from Distrito Federal
Relataram-se quatro casos de dermatofilose em ovinos da raça Santa Inês, no perÃodo de um ano. Microscopicamente observaram-se filamentos na forma de "trilho de bonde" e zoósporos nos quatro casos. A tentativa do isolamento do microrganismo foi realizada por meio do método de Haalstra e em apenas um caso obteve-se sucesso, observando-se colônias de aparência lisa, formato circular, cor amarelada e hemolÃtica em ágar sangue. O exame direto com coloração de Gram mostrou-se um método bastante eficiente na confirmação da presença do microrganismo afetando a epiderme em razão da morfologia tÃpica do agente.Four cases of dermatophylosis were reported in Santa Inês sheep in a study period of one year. Microscopically, septate filaments and coccoid forms zoospores were observed. Attempts to isolate the microorganisms were accomplished using Haastra's method and it was successful in only one case. Dermatophilus congolensis samples have grown on blood agar, colonies where hemolytic, small, round and pigmentation vary from yellow to orange. The gram staining method was efficient to confirm the presence of the microorganism affecting the epidermis due to typical morphology of the agent
- …