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Toward functional imaging of the placentaStevenson, Gordon N. January 2014 (has links)
In obstetrics, the application of computer-based image analysis to provide deeper insight into pathology in early pregnancy is highly desirable but underdeveloped. One such pathology, fetal growth restriction (FGR) is a leading cause of mortality and morbidity in pregnancy. FGR affects approximately 3-10% of pregnancies in the western world leading to increased risk of stillbirth and health problems in later life. Morphometric or functional measurement of the placenta in pregnancy in utero may aid diagnosis of this pathology as the interface between placenta and mother is the site where the pathology manifests itself. Detection of growth restriction is yet to be resolved as poor, unreliable biochemical and image-based biomarkers have made it hard to detect and manage these pregnancies effectively. By the provision and development of tools for quantification of the placenta by three dimensional (3D) ultrasound (US) using image segmentation and mesh pro- cessing, this thesis aims to better facilitate clinical investigation of this major problem in obstetric healthcare. In a first contribution, 3D placental volume measurement using 3D US is used to classify the difference between normal and FGR pregnancies. Volume was estim- ated using the semi-automated random walker (RW) algorithm. The repeatability and reliability of the method was tested between three observers and showed the new method to be equivalent to manual segmentation. In a study of 143 women performed by our clinical partners, significantly smaller placental volume was found in pregnancies defined as small-for-gestational age (SGA). Expanding on volumetry, the utero-placental interface (UPI) is the location where the pathology that leads to FGR occurs. Manual manipulation of the volume is requiredtovisualisetheinterface, soweinvestigatedapplyinga“meshflattening” process to convert the contorted UPI into a disc to provide a standardised way to view the interface between acquistions and subjects. Finally, an existing, two dimensional (2D) Doppler standardisation technique was extended into 3D to provide standardisation of values of Doppler vascularity. This technique was then applied to measure the vascularity of volumes of interest relat- ive to the interface between placenta and mother. This test was then applied clin- ically in 143 women and found that the vascularity of the small-for-gestational age (SGA) pregnancies was significantly smaller than that of the population who produced appropriately sized babies. These three tools each provide augmentation of our understanding of placental health and function in pregnancy. From measuring the gross volume to estimat- ing the blood flow we show the potential clinical application for image analysis performed on 3D power Doppler (PD) ultrasound volumes.
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Vibrational Spectroscopic and Ultrasound Analysis for In-Process Characterization of High-Density Polyethylene/Polypropylene Blends During Melt ExtrusionScowen, Ian J., Brown, Elaine, Sibley, M.G. 13 July 2009 (has links)
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Análise genética para maciez de carne e suas relações com as características produtivas em bovinos nelore mocho / Genetic analysis of meat tenderness and its relationships with productive traits in polled nellore cattleMamede, Mariana Márcia Santos 09 July 2015 (has links)
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Previous issue date: 2015-07-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Genetic parameters were estimated for growth traits involving the weights at 120 (P120), 210 (P210), 365 (P365), and 450 (P450) days of age, reproductive traits, such as scrotal circumference calculated at 365 (PE365) and 450 (PE450) days of age, age at first calving (IPP), accumulated productivity (PAC) in kg of weaned calves, and cow stayability (STAY - Stayability), carcass, considering ribeye area (REA), subcutaneous fat thickness (EG), and fat thickness on the back (EGP8), and the tenderness of the meat, as measured by Warner-Bratzler shear force (WBSF) in polled Nellore cattle reared in the Cerrado biome. For all features, Bayesian analysis bi characteristics were performed by adopting linear animal model, whereas for the analyzes involving STAY, the linear threshold model was used. Mean posterior heritability estimates for P120 (0.20), P210 (0.21), P365 (0.44), P450 (0.40), PE365 (0.31), PE450 (0.37), IPP (0.16), PAC (0.25), STAY (0.16), AOL (0.30), EG (0.13), EGP8 (0.24), and WBSF (0.16) indicate response to the selection process. Estimates of maternal heritability for P120 (0.10) and P210 (0.09) suggest genetic effects of breeding in contributing to the performance of calves at weaning. Estimates of genetic and environmental correlation obtained for the growth characteristics were of high magnitude. By analyzing the growth characteristics with carcass, the genetic and residual correlations between AOL weights at 210 (0.46 and 0.37, respectively), 365 (0.59 and 0.39, respectively), and 450 (0.56 and 0.50, respectively) days old stood out. Genetic and residual correlations between PE365 and PE450 were high and positive (0.91 and 0.74, respectively), as well as the genetic correlations of the CAP with PE365, PE450, IPP, and STAY (0.61, 0.62, -0.69 and 0.83, respectively). Therefore, PE365, PE450, and CAP are important selection criteria, which result in genetic progress for IPP and STAY. The AOL genetic correlations with EG (0.25) and EGP8 (0.06) were of low magnitude, however moderate between EG and EGP8 (0.49). The residual correlation between carcass traits showed low non-additive genetic association and/or of the environment. The WBSF mean estimates of genetic and residual correlations with reproductive and carcass traits were favorable, although they exhibited high standard deviations. The genetic correlation of WSBF with the weights were higher at the pre-weaning phase (-0.70 ± 0.26 with P120 and -0.78 ± 0.23 with P210) and lower at the post-weaning phase (-0.44 ± 0.43 with P365 and -0.22 ± 0.34 with P450). Estimates of genetic correlation of WBSF with EG, EGP8, and AOL were negative and close to zero. Residual correlations of WBSF with all the growth and carcass traits were negligible. / Foram estimados os parâmetros genéticos para as características de crescimento envolvendo os pesos aos 120 (P120), 210 (P210), 365 (P365) e 450 (P450) dias de idade, reprodutivas de perímetro escrotal calculados aos 365 (PE365) e 450 (PE450) dias de idade, idade ao primeiro parto (IPP), produtividade acumulada (PAC) em kg de bezerros desmamados, e habilidade de permanência da vaca no rebanho (STAY - Stayability), de carcaça, considerando área de olho de lombo (AOL), espessura de gordura subcutânea (EG) e espessura de gordura subcutânea na garupa (EGP8) e a de maciez da carne, medida pela força de cisalhamento Warner-Bratzler (WBSF) em bovinos Nelore Mochos, criados no bioma Cerrado. Para todas as características foram realizadas análises bayesianas bi características adotando-se modelo linear animal, enquanto que para as análises envolvendo a STAY, o modelo adotado foi o linear-limiar. As médias das estimativas posteriores de herdabilidade para o P120 (0,20), P210 (0,21), P365 (0,44), P450 (0,40), PE365 (0,31), PE450 (0,37), IPP (0,16), PAC (0,25), STAY (0,16), AOL (0,30), EG (0,13), EGP8 (0,24) e WBSF (0,16) indicam resposta ao processo de seleção. As estimativas de herdabilidade maternal para P120 (0,10) e P210 (0,09) sugerem efeitos genéticos das reprodutoras na contribuição para o desempenho dos bezerros até a fase de desmame. As estimativas de correlação genética e ambiental obtidas para as características de crescimento foram de elevada magnitude. Ao analisar as características de crescimento com as de carcaça, destacam-se as correlações genéticas e residuais entre AOL com os pesos aos 210 (0,46 e 0,37, respectivamente), 365 (0,59 e 0,39, respectivamente) e 450 (0,56 e 0,50, respectivamente) dias de idade. As correlações genéticas e residuais entre PE365 e PE450 foram elevadas e favoráveis (0,91 e 0,74, respectivamente), assim como as correlações genéticas da PAC com PE365, PE450, IPP e STAY (0,61, 0,62, -0,69 e 0,83, respectivamente). Portanto, em função da o PE365, PE450 e a PAC são importantes critérios de seleção, os quais implicaram em progresso genético para IPP e STAY. As correlações genéticas de AOL com EG (0,25) e com EGP8 (0,06) foram de baixa magnitude, entretanto moderada entre EG e EGP8 (0,49). A correlação residual, entre as características de carcaça, indicou baixa associação genética não-aditiva e, ou, de ambiente. As médias das estimativas de correlações genéticas e residuais de WBSF com as características reprodutivas e de carcaça foram favoráveis, entretanto exibiram desvios padrão elevados. A correlação genética da WSBF com os pesos foi maior na fase pré-desmama, (-0,70±0,26 com P120 e -0,78±0,23 com P210) e menor na fase pós-demama (-0,44±0,43 com P365 e -0,22±0,34 com P450). As estimativas de correlação genética da WBSF com EG, EGP8 e AOL foram negativas e próximas à zero. As correlações residuais de WBSF com todas as características de crescimento e de carcaça foram inexpressivas.
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Studium chování vybraných hornin při působení vysokých teplot / Study of the behavior of selected rocks at high temperaturesHolanec, Aleš January 2022 (has links)
The diploma thesis deals with the observation and diagnostics of transformations that take place in stone slabs of different mineralogical composition during heating to high temperatures. The theoretical part of the thesis deals with a summary of available information about selected types of rocks. Furthermore, it presents findings from the experimental thermal loading of a granite sample. The principles and instruments of laboratory experimental methods that are used to judge the resistance of rocks are described in detail. In the experimental part, the testing methodology is proposed, the procedure of production of rock test specimens is described and the way in which the thermal loading of stone slabs took place is explained. The results of the experiments are shown in the tables and graphs. A comparison of individual tests and properties of selected samples and evaluation of the obtained results is performed.
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