The aim of this project is to develop a computational model of the structure and function of the ocular lens, specifically the solute and fluid transport in the lens. The modelling framework was based on finite volume methods. The intracellular and extracellular solute fluxes were modelled using the Nernst-Plank equation with an extra term to capture solute fluxes due to advection. The modelling framework included equations describing the flux through the Na+ /K+ pumps and K+ channels in the surface membrane, and Na+ and Cl- channels in the fibre cell membrane. The intracellular fluid flow between adjacent fibre cells was modelled by a homogenised transmembrane fluid flow equation and the intracellular fluid flow along the fibre cell was modelled as Poiseuille flow. The extracellular fluid flow was modelled as Couette flow with an extra term to capture electro-osmotic flow. The fluid flow through the fibre cell membrane and surface membrane was modelled as transmembrane fluid flow. The governing equations account for the structural properties of the lens, such as the tortuosity of the extracellular cleft, the intracellular and extracellular volume fractions, and the membrane density. A one-dimensional model of the Na+ , K+ , Cl- and fluid transport in the frog lens was developed. This model was based on the analytic model developed by Mathias (1985b). The results were consistent with the results from the analytic model and experimental data. Two versions of the two-dimensional model were developed. In the first model, the parameters were spatially constant except for the distribution of the Na+ /K+ pump currents at the lens surface and the fibre cell angles. The second model was the same, except the extracellular cleft width and fibre cell height was spatially varied to represent the sutures and the diffusion barrier. These models were solved and compared with each other and with experimental data. Compared to the first, the second model predicted a significantly larger circulation of solutes and fluid between the pole and equator. It predicted a 12-20% increase in the penetration of Na+ , K+ and fluid into the lens. The second model also predicted a 300-400% increase in Cl- penetration and, unlike the first model, a Cl- circulation between the poles and equator. This is significant since Cl- is not an actively transported solute. These results highlight the strong structure-function relationship in the lens and the importance of an accurate spatial representation of model parameters. The direction of the current, solute fluxes and fluid flow that were predicted by the model were consistent with experimental data but the magnitude of the surface current was a tenth to a third of the values measure by the vibrating probe. To demonstrate the application of the lens model, the two-dimensional model was used to simulate age-related changes in lens physiology. This was done by increasing the radius of the lens to simulate growth with age. The model predicted an increase in the intracellular Na+ concentration, Cl- concentration and potential, and a decrease in the intracellular K+ concentration with age. These trends were consistent with those observed by Duncan et al. (1989), except for the intracellular K+ concentration, where they reported no change with age. The two-dimensional model forms a foundation for future developments and applications.

The aim of this project is to develop a computational model of the structure and function of the ocular lens, specifically the solute and fluid transport in the lens. The modelling framework was based on finite volume methods. The intracellular and extracellular solute fluxes were modelled using the Nernst-Plank equation with an extra term to capture solute fluxes due to advection. The modelling framework included equations describing the flux through the Na+ /K+ pumps and K+ channels in the surface membrane, and Na+ and Cl- channels in the fibre cell membrane. The intracellular fluid flow between adjacent fibre cells was modelled by a homogenised transmembrane fluid flow equation and the intracellular fluid flow along the fibre cell was modelled as Poiseuille flow. The extracellular fluid flow was modelled as Couette flow with an extra term to capture electro-osmotic flow. The fluid flow through the fibre cell membrane and surface membrane was modelled as transmembrane fluid flow. The governing equations account for the structural properties of the lens, such as the tortuosity of the extracellular cleft, the intracellular and extracellular volume fractions, and the membrane density. A one-dimensional model of the Na+ , K+ , Cl- and fluid transport in the frog lens was developed. This model was based on the analytic model developed by Mathias (1985b). The results were consistent with the results from the analytic model and experimental data. Two versions of the two-dimensional model were developed. In the first model, the parameters were spatially constant except for the distribution of the Na+ /K+ pump currents at the lens surface and the fibre cell angles. The second model was the same, except the extracellular cleft width and fibre cell height was spatially varied to represent the sutures and the diffusion barrier. These models were solved and compared with each other and with experimental data. Compared to the first, the second model predicted a significantly larger circulation of solutes and fluid between the pole and equator. It predicted a 12-20% increase in the penetration of Na+ , K+ and fluid into the lens. The second model also predicted a 300-400% increase in Cl- penetration and, unlike the first model, a Cl- circulation between the poles and equator. This is significant since Cl- is not an actively transported solute. These results highlight the strong structure-function relationship in the lens and the importance of an accurate spatial representation of model parameters. The direction of the current, solute fluxes and fluid flow that were predicted by the model were consistent with experimental data but the magnitude of the surface current was a tenth to a third of the values measure by the vibrating probe. To demonstrate the application of the lens model, the two-dimensional model was used to simulate age-related changes in lens physiology. This was done by increasing the radius of the lens to simulate growth with age. The model predicted an increase in the intracellular Na+ concentration, Cl- concentration and potential, and a decrease in the intracellular K+ concentration with age. These trends were consistent with those observed by Duncan et al. (1989), except for the intracellular K+ concentration, where they reported no change with age. The two-dimensional model forms a foundation for future developments and applications.

The aim of this project is to develop a computational model of the structure and function of the ocular lens, specifically the solute and fluid transport in the lens. The modelling framework was based on finite volume methods. The intracellular and extracellular solute fluxes were modelled using the Nernst-Plank equation with an extra term to capture solute fluxes due to advection. The modelling framework included equations describing the flux through the Na+ /K+ pumps and K+ channels in the surface membrane, and Na+ and Cl- channels in the fibre cell membrane. The intracellular fluid flow between adjacent fibre cells was modelled by a homogenised transmembrane fluid flow equation and the intracellular fluid flow along the fibre cell was modelled as Poiseuille flow. The extracellular fluid flow was modelled as Couette flow with an extra term to capture electro-osmotic flow. The fluid flow through the fibre cell membrane and surface membrane was modelled as transmembrane fluid flow. The governing equations account for the structural properties of the lens, such as the tortuosity of the extracellular cleft, the intracellular and extracellular volume fractions, and the membrane density. A one-dimensional model of the Na+ , K+ , Cl- and fluid transport in the frog lens was developed. This model was based on the analytic model developed by Mathias (1985b). The results were consistent with the results from the analytic model and experimental data. Two versions of the two-dimensional model were developed. In the first model, the parameters were spatially constant except for the distribution of the Na+ /K+ pump currents at the lens surface and the fibre cell angles. The second model was the same, except the extracellular cleft width and fibre cell height was spatially varied to represent the sutures and the diffusion barrier. These models were solved and compared with each other and with experimental data. Compared to the first, the second model predicted a significantly larger circulation of solutes and fluid between the pole and equator. It predicted a 12-20% increase in the penetration of Na+ , K+ and fluid into the lens. The second model also predicted a 300-400% increase in Cl- penetration and, unlike the first model, a Cl- circulation between the poles and equator. This is significant since Cl- is not an actively transported solute. These results highlight the strong structure-function relationship in the lens and the importance of an accurate spatial representation of model parameters. The direction of the current, solute fluxes and fluid flow that were predicted by the model were consistent with experimental data but the magnitude of the surface current was a tenth to a third of the values measure by the vibrating probe. To demonstrate the application of the lens model, the two-dimensional model was used to simulate age-related changes in lens physiology. This was done by increasing the radius of the lens to simulate growth with age. The model predicted an increase in the intracellular Na+ concentration, Cl- concentration and potential, and a decrease in the intracellular K+ concentration with age. These trends were consistent with those observed by Duncan et al. (1989), except for the intracellular K+ concentration, where they reported no change with age. The two-dimensional model forms a foundation for future developments and applications.

Lentils, one of the cool-season pulses, are consumed as a staple food in most developing countries. The demand for pulses in western societies is increasing because of its valuable nutritional quality and an increased awareness of health issues. Australia has a good reputation for producing clean low moisture legume products and could increase as market share of lentil production by identifying, developing and promoting good quality varieties.Lentils which are graded as good quality varieties must have a short and uniform cooking time, without 'hard to cook' seed, have the hull stay attached to the seed during cooking, and have a final acceptable taste, texture, flavour and appearance after cooking (Bhatty 1990). Cooking quality in this study is defined as the maximum force (N) that is required to compress the whole seed cooked product after cooking for a standard period of time. This study aims to develop an objective measurement to determine the cooking quality of lentils and thereby evaluates the relationships between lentil cooking quality and some of its physical and biochemical properties. Four cultivars used (Cassab, Digger, ILL 7180 and Matilda) were grown during 1999 at Mullewa and Pingaring, Western Australia. The relationship between the cooking quality of lentil and water absorption, seed size, seed coat thickness, phytic acid, mineral composition and initial moisture content was investigated.Texture measurement was carried out using the TA.XT2i meter as an alternative to the subjective method "Cooking time test". By comparing the cooking time determined by 'Cooking time test, 220 N was established and suggested as an optimal peak compression force to determine the adequate cooking time for lentils. Both methods showed that 35 minutes cooking time was adequate for red lentils (Cassab, Digger, and ILL 7180), and 45 minutes for green lentils ++ / (Matilda).Cooking significantly reduced the hardness of the seeds (R= - 0.752 to - 0.89) and promoted mineral leaching (P < 0.05). The interaction between environment and genotype had a significant effect on seed size, seed coat thickness, mineral composition (Phytic acid, Ne, K+, Mg2+, Ca2+ M+, Fe2+ and CU2+) and hardness (P< 0.05). Seed coat thickness did not correlated with this rate of water uptake and cooking quality. Growing environments had a greater influence on the cooking quality than genotypes. Lentils grown at Pingaring are generally had a higher in Phyti acid content, better mineral retention and were harder in texture than those grown at Mullewa.The results of this study implicated that the peak compression force (220 N) was identified as an indicator to determine the cooking time of lentil cultivars. Texture Profile Analysis (TPA) is a useful method to evaluate various texture characteristics (hardness, cohesiveness, chewiness, springiness, gumminess and adhesiveness) of lentil cultivars. Cooking quality of lentil is significantly affected by the effect of varieties and growing locations. However, not the various biochemical compositions (phytic acid and minerals) and the thickness of seed coat have no significant effect on the cooking quality of lentil.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 7 uppsatser.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (p. 193-221) Also available in print.

Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [78]-85).

Thesis (M.S.)--Ohio State University, 2009. / Title from first page of PDF file. Includes vita. Includes bibliographical references (p. 41-46).

Made available in DSpace on 2014-06-11T19:31:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2005Bitstream added on 2014-06-13T18:41:49Z : No. of bitstreams: 1 rodrigues_gn_dr_botfmvz.pdf: 4865487 bytes, checksum: 4d614b1bb25a841f92667f0c608bf5b7 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo do presente estudo foi avaliar o comportamento do olho canino após a cirurgia para extração de catarata, com e sem implante de lente intra-ocular (LIO) em piggyback, frente a pressão intra-ocular, espessura e curvatura corneanas, densidade e área das células do endotélio da córnea. Empregaram-se, 25 animais da espécie canina de sexo, raça e idades variadas, portadores de catarata, subdivididos em 4 grupos designados por G1 (cães portadores de catarata imatura, com implante de LIO), G2 (cães portadores de catarata madura, com implante de LIO), G3 (cães portadores de catarata imatura, sem implante de LIO) e G4 (cães portadores de catarata madura, sem implante de LIO). A técnica cirúrgica foi a facoemulsificação bimanual. As avaliações da pressão intra-ocular, curvatura e espessura da córnea, foram aferidas antes do procedimento cirúrgico (0) enquanto que, as avaliações das densidade e área das células do endotélio corneano foram realizadas antes do procedimento cirúrgico (0) e nos tempos 7, 28 e 60 dias após o procedimento cirúrgico. A estatística utilizada foi a Análise de Perfil, seguida do método de Tukey para comparações múltiplas, com nível de significância de 5%. Os resultados não demonstraram diferença significativa entre os quatro grupos analisados, no entanto, houve diferença na comparação entre os olhos operados e os contra-laterais. A avaliação qualitativa realizada durante o pós-operatório demonstrou uma maior reação inflamatória e um maior índice de complicações entre os animais dos grupos 1 e 2. Concluí-se que não houve diferença entre os grupos, no entanto, demonstrou-se diferença entre o olho operado e não-operado. Entretanto, o pós-operatório dos animais dos grupos 1 e 2 revelou-se mais complicado, expressando uma reação inflamatória mais exacerbada e um maior índice de complicações. / The purpose of this study was to investigate the effects in intraocular pressure, central corneal thickness, corneal curvature, cellular density and area of corneal endothelium after surgery for cataract extraction with and without intraocular lens (IOL) implantation using piggyback technique in eyes of dogs. A total of 25 dogs were divided into 4 groups: Group 1 (dogs with immature cataract and with IOL implantation), Group 2 (dogs with mature cataract and with IOL implantation), Group 3 (dogs with immature cataract and without IOL implantation) and Group 4 (dogs with mature cataract and without IOL implantation). The surgical technique performed was bimanual phacoemulsification. Intraocular pressure, central corneal thickness and corneal curvature were measured before surgery (0) and at 3, 7, 14, 21, 28, 60 days of postoperative. Cellular density and area of corneal endothelium were measured before surgery and at 7, 28, 60 days of postoperative. Statistical analysis was performed using variance analysis (profile) and Tukey test for multiple comparison with significance at p<0.05. The 4 groups did not differ significantly with respect to parameters evaluated. There was, however, a significant difference between the two eyes (operated and nonoperated). However, the dogs of groups 1 and 2 had more complicate postoperative with more severe ocular inflammation and number of complications.

Made available in DSpace on 2014-06-11T19:27:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-04-04Bitstream added on 2014-06-13T20:35:25Z : No. of bitstreams: 1 valinhos_mar_me_botfmvz.pdf: 604025 bytes, checksum: 99098100284f34af46bd3aaa890c8b1d (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O trabalho teve por objetivos determinar as dimensões oculares de coelhos, empregando ultrassonografia modo-A e ceratometria, a fim de utilizá-las como subsídios para calcular o poder dióptrico de lentes intraoculares, assim como, avaliar se existe diferença entre as mensurações oculares de machos e fêmeas, bem como entre olho esquerdo e olho direito em coelhos. Foram utilizados 58 animais do Grupo Genético Botucatu, divididos entre 30 fêmeas e 28 machos, com idade média de 85,8 ± 8,29 dias e peso médio de 2,3 ± 0,46 kg. O cálculo da lente intraocular foi realizado através do software Holladay IOL Consultant®. As fórmulas empregadas para o cálculo foram: Holladay II, Holladay I, Hoffer Q e SRK-T que calcularam um poder dióptrico médio para as lentes de 48,5 D; 50,27 D; 59,67 D e 49,24 D, respectivamente. A fórmula SRK-T mostrou-se estatisticamente semelhante às fórmulas Holladay II e Holladay I, enquanto as demais se mostraram diferentes entre si. Os parâmetros biométricos oculares avaliados, assim como o poder dióptrico calculado por uma mesma fórmula não apresentaram diferenças significativas com relação ao sexo e a lateralidade / The present study aimed to determine the dimensions of the rabbits eyes using A-mode ultrasound and keratometry, in order to use them as data for calculating the dioptric power of intraocular lenses, as well as assess whether there are differences of ocular measurements between males and females and between the left eye and right eye in rabbits. Fifty-eight animals (30 females and 20 males) of the Genetic Botucatu Group, with a mean age of 85 days and average weight of 2.26 kg were used. The calculation of the intraocular lens was performed using Holladay IOL Consultant ®. The formulas used for the calculation were: Holladay II, Holladay I, Hoffer Q and SRK-T which estimated a mean dioptric power lenses about 48.5 D, 50.27 D, 59.67 D and 49.24 D, respectively. The SRK-T was statistically similar to the Holladay II and Holladay I, while the others were different from each other. Ocular biometric parameters evaluated, as the lens power calculated by the same formula showed no significant differences in relation to gender and laterality