Current analysis of the life and death cycles of in vitro cellular systems is based on visual observation methods relying upon morphological changes monitored using a microscope. Data collected from these techniques are not as precise as scientists desire them to be. The methods are discontinuous, indirect, costly, and time and labor intensive. The human element plays a significant part in error propagation as individual style of the researcher lends to skewing the data. Experimental results will differ greatly from laboratory to laboratory just because the methods of monitoring cellular activity are not standardized. The researcher uses experience to determine the best way to collect data quickly and "accurately" according to his or her definition. There is a great need not only to standardize data collection processes, but also to eliminate human error induced by lack of experience or fatigue. This research proposes a fiber optic based monitoring system as a possible solution to eliminate a number of problems with current cellular data collection methods and to increase the data collection rate tremendously since the process could be automated. / Master of Science

The purpose of this thesis is to investigate the effect of dispersion on a spectrum-sliced WDM (SS-WDM) system, specifically a system employing a single-mode optical fiber. The system performance is expressed in term of the receiver sensitivity defined as the average number of photon per bit <i>N_p</i>required for a given probability of bit error <i>P_e</i>. The receiver sensitivity is expressed in terms of two normalized parameters: the ratio of the optical bandwidth per channel and the bit rate <i>m</i>=<i>B</i>₀<i>/R_b</i>=<i>B</i>₀<i>T</i>, and the transmission distance normalized by the dispersion distance <i>z/L_D</i>. The former represents the effect of the excess beat noise caused by the signal fluctuation. The latter represents the effect of dispersion. The excess beat noise can be reduced by increasing the value of <i>m</i> (increasing the optical bandwidth<i> B</i>₀ for a given bit rate<i> R_b</i>). However, a large <i>m</i> implies that the degradation due to the dispersion is severe in a system employing a single-mode fiber. Therefore, there should be an optimum <i>m</i> resulting from the two effects. The theoretical results obtained from our analysis have confirmed this prediction. It is also shown that the optimum <i>m</i> (<i>m_opt</i>) decreases with an increase in the normalized distance. This suggests that the dispersion strongly affects the system performance. The increase in the excess beat noise is traded for the decrease in the dispersion effect. Additionally, the maximum transmission distance is relatively short, compared to that in a laser-based system. This suggests that the SS-WDM systems with single-mode fibers are suitable for short-haul systems, such as high-speed local-access network where the operating bit rate is high but the transmission distance is relatively short. / Master of Science

No

No / To present a computational model mapping visual field (VF) locations to optic nerve head (ONH) sectors accounting for individual ocular anatomy, and to describe the effects of anatomical variability on maps produced. A previous model that related retinal locations to ONH sectors was adapted to model eyes with varying axial length, ONH position and ONH dimensions. Maps (n = 11,550) relating VF locations (24-2 pattern, n = 52 non–blind-spot locations) to 1° ONH sectors were generated for a range of clinically plausible anatomical parameters. Infrequently mapped ONH sectors (5%) were discarded for all locations. The influence of anatomical variables on the maps was explored by multiple linear regression. Across all anatomical variants, for individual VF locations (24-2), total number of mapped 1° ONH sectors ranged from 12 to 90. Forty-one locations varied more than 30°. In five nasal-step locations, mapped ONH sectors were bimodally distributed, mapping to vertically opposite ONH sectors depending on vertical ONH position. Mapped ONH sectors were significantly influenced (P < 0.0002) by axial length, ONH position, and ONH dimensions for 39, 52, and 30 VF locations, respectively. On average across all VF locations, vertical ONH position explained the most variance in mapped ONH sector, followed by horizontal ONH position, axial length, and ONH dimensions. Relations between ONH sectors and many VF locations are strongly anatomy-dependent. Our model may be used to produce customized maps from VF locations to the ONH in individual eyes where some simple biometric parameters are known. / ustralian Research Council Linkage Project LP100100250 (with Heidelberg Engineering GmbH, Germany); Australian Research Council Future Fellowship FT0990930 (AMM); Australian Research Council Future Fellowship FT0991326 (AT)

Nogo is well established for its inhibitory action on axon regeneration in the adult central nervous system. It binds to the Nogo receptor (NgR) through an extracellular active site on the protein-Nogo-66. Although it is reported that Nogo is widely expressed in the developing brain, its exact function during development of the nervous system is unclear. / The contribution of Nogo on patterning the axon routing at the optic chiasm of mouse embryo was investigated in this thesis. Using immunocytochemical staining, Nogo protein was localized on the Miller glial cells in the retina and at the optic disk. A few migrating retinal neurons also expressed Nogo. In the chiasm, Nogo was localized exclusively on the radial glia, which generate a midline domain where turning of uncrossed axons occurs. In vitro study showed expression of NgR on retinal neurites and growth cones, and neurite outgrowth from both dorsal nasal (contralaterally projecting) and ventral temporal (ipsilaterally projecting) retina was inhibited by Nogo. In the pathway, NgR expression was regionally regulated. NgR was obvious in the optic stalk and the optic tract, but not in the chiasm. Blocking Nogo function with NEP1-40, a peptide antagonist of NgR, in brain slice culture of the pathway produced significant reduction in the uncrossed projection, but had no effect on axon crossing at the midline. Furthermore, the age related fiber arrangement in the optic tract was abolished after disturbing of Nogo function. Similar abnormalities were observed in slices treated with Nogo blocking antibody. In vitro studies showed that NEP1-40 rescued the inhibition of Nogo to the retinal neurites. The downregulation of NgR at the chiasm was supported by in vitro assays showing significant reduction of receptor expression on dorsal nasal but not ventral temporal growth cones when they encountered the chiasm, thus generating a differential inhibition to ventral temporal neurites. / These results provide evidences that Nogo is a guidance molecule during the development of CNS. Interaction of Nogo and its receptor plays important role for patterning the axon divergence in the mouse optic pathway and the age related fiber order in the optic tract. / Wang Jun. / "September 2006." / Adviser: Sun-On Chan. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1474. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 130-142). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Chung Kit Ying. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 90-104). / Abstracts in English and Chinese. / Chapter Chapter 1 --- General Introduction --- p.1-22 / Chapter Chapter 2 --- Expression of Chondroitin Sulfate Proteoglycans (CSPGs) in the Chiasm of Mouse Embryos / Introduction --- p.23-24 / Materials and Methods --- p.25 -27 / Results --- p.28-33 / Discussion --- p.34-40 / Figures --- p.41-45 / Chapter Chapter 3 --- Effects on Axon Routing after Removal of Chondroitin Sulfate Proteoglycans by Enzymatic Digestion / Introduction --- p.46 -47 / Materials and Methods --- p.48 -50 / Results --- p.57 / Discussion --- p.57-61 / Figures --- p.62-66 / Chapter Chapter 4 --- Immediate Effects of Prenatal Monocular Enucleation on the Cellular and Molecular Environment in the Development of Retinofugal Pathway / Introduction --- p.67-69 / Materials and Methods --- p.70-72 / Results --- p.73.77 / Discussion --- p.78-82 / Figures --- p.83-86 / Chapter Chapter 5 --- General Conclusion --- p.87-89 / References --- p.90 -104

Leung Kin Mei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 106-125). / Abstracts in English and Chinese. / Chapter CHAPTER 1 --- GENERAL INTRODUCTION --- p.1-11 / Chapter CHAPTER 2 --- ENZYMATIC REMOVAL OF CHONDROITIN SULFATES ABOLISHES THE AGE-RELATED ORDER IN THE OPTIC TRACT OF MOUSE EMBRYOS / INTRODUCTION --- p.12-13 / MATERIALS AND METHODS --- p.13-18 / RESULTS --- p.18-24 / DISCUSSION --- p.24-29 / FIGURES --- p.30-39 / Chapter CHAPTER 3 --- EXPRESSION OF PHOSPHACAN AND NEUROCAN IN THE DEVELOPING MOUSE RETINOFUGAL PATHWAY / INTRODUCTION --- p.40-42 / MATERIALS AND METHODS --- p.42-43 / RESULTS --- p.44-49 / DISCUSSION --- p.49-55 / FIGURES --- p.56-61 / Chapter CHAPTER 4 --- HEPARAN SULFATE PROTEOGLYCAN EXPRESSION IN THE OPTIC CHIASM OF MOUSE EMBRYOS / INTRODUCTION --- p.62-63 / MATERIALS AND METHODS --- p.63-65 / RESULTS --- p.66-70 / DISCUSSION --- p.70-76 / FIGURES --- p.77-82 / Chapter CHAPTER 5 --- EXPRESSION OF NEURAL CELL ADHESION MOLECULES IN THE CHIASM OF MOUSE EMBRYOS / INTRODUCTION --- p.83-85 / MATERIALS AND METHODS --- p.85-88 / RESULTS --- p.88-92 / DISCUSSION --- p.92.95 / FIGURES --- p.96-102 / Chapter CHAPTER 6 --- GERNEAL CONCLUSION --- p.103-105 / REFERENCES --- p.106-125

Mise en oeuvre de circuits intégrés dédiés à l’analyse des corrélations temporelles des tavelures optiquesOn pourrait chercher à exploiter, à des fins de diagnostic médical, la forte pénétration au sein des tissus biologiques de la lumière située dans l’infrarouge proche. Cependant la nature diffusante des tissus brouille fortement l’information spatiale, et il faut mesurer plusieurs paramètres pour obtenir des informations pertinentes, avec par exemple des mesures résolues en temps, ou des mesures de corrélations de speckle. Ces dernières sont délicates de par le faible flux lumineux dans un grain de speckle et les temps de corrélations très courts observés avec les tissus. L’équipe d’optique en milieu aléatoire du Laboratoire de Physique des Lasers a développé, en collaboration avec l’Institut d’Electronique Fondamentale, un concept de circuit multipixels dédié à la détection et à l’analyse du speckle. Ce circuit traite individuellement différents grains de speckle en parallèle, et calcule en temps réel une grandeur moyenne sur l’ensemble des pixels, améliorant ainsi le rapport signal à bruit. Chaque pixel de détection est capable d’effectuer une détection synchrone du signal, et de calculer différentes corrélations temporelles. L’objectif de cette thèse était de caractériser une nouvelle génération de circuits, et de les mettre en oeuvre dans différentes expériences d’optique diffuse. Nous avons pu, au cours de ces travaux, mesurer les corrélations temporelles du speckle en fonction du temps de transit à travers 4cm de lait, et ce malgré la décorrélation très rapide observée dans ce cas. Nous avons également réalisé des expériences d’imagerie acousto-optique, en collaboration avec l’Institut Langevin, en développant un nouveau protocole de mesure adapté à notre technologie. / Implementation of Application Specific Integrated Circuits dedicated to the analysis of speckle patterns temporal correlationsThe fact that near infrared light has a good penetration depth inside biological tissues calls to its exploitation for medical diagnosis purposes. However, given their scattering nature, tissues strongly blur the spatial information. One therefore needs to measure several parameters in order to obtain pertinent information. One can for instance use time-resolved detection, or measure speckle correlations. The latter implies serious technological bottlenecks due to the weakness of the light flux in one speckle grain, and due to the very short correlation times observed in tissues. The biomedical optics group of Laboratoire de Physique de Lasers, in collaboration with Institut d'Electronique Fondamentale, has developed a concept of multipixels ASIC dedicated to speckle detection and analysis. This device processes different speckle grains in parallel, and computes an averaged value across all the pixels in real time in order to improve the signal to noise ratio. Each detection pixel can perform a lock-in detection of the signal, and compute different time correlations. The objective of this thesis is to characterize a new generation of circuits, and to implement them in different experiments on diffuse light propagation. One highlight of this work is the fact that we could compute speckle time correlation as a function of the transit time through 4 cm of milk, despite the very fast decorrelation obtained with such a medium. In addition, we performed acousto-optic imaging experiments with our partners from Institut Langevin, developing for that purpose a new protocol appropriate to our technology.

Chan, Chung Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 98-110). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract in Chinese --- p.iv / Acknowledgements --- p.v / Table of Abbreviations --- p.vi / Table of Contents --- p.vii / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter Chapter 2 --- Functions of hyaluronan in the development of retinofugal pathway / Introduction --- p.18 / Materials and Methods --- p.19 / Results --- p.23 / Discussion --- p.26 / Figures --- p.32 / Chapter Chapter 3 --- Characterization of Nogo and its receptor in retinofugal pathway using Western blot analysis / Introduction --- p.40 / Materials and Methods --- p.42 / Results --- p.50 / Discussion --- p.52 / Figures --- p.57 / Chapter Chapter 4 --- Expression patterns and functions of Sonic hedgehogin retinofugal pathway / Introduction --- p.62 / Materials and Methods --- p.64 / Results --- p.69 / Discussion --- p.76 / Figures --- p.81 / Chapter Chapter 5 --- General Discussion --- p.91 / Figures --- p.95 / References --- p.98

Glaucoma is the second leading cause of irreversible blindness in the United States and is the leading cause of blindness in African Americans. Cupping or excavation of the optic nerve, which sends the visual signal from the photoreceptors in the eye to the brain, is a chief feature of glaucoma. A similar excavated appearance of the optic nerve is also the primary clinical sign of other congenital malformations of the eye including optic nerve head coloboma, optic pit, and morning glory disc anomaly collectively termed cavitary optic disc anomaly (CODA). Clinical similarities between CODA and glaucoma have suggested that these conditions may have overlapping pathophysiology. Although risk factors are known, such as the elevated intraocular pressure (IOP) observed in some glaucoma subjects, the biological pathways and molecular events that lead to excavation of the optic disc in glaucoma and in CODA are incompletely understood, which has hindered efforts to improve diagnosis and treatment of these diseases. Consequently, there is a critical need to clarify the biological mechanisms that lead to excavation of the optic nerve, which will lead to improvements in our understanding of these important disease processes. Because of their similar clinical phenotypes and the limited therapy geared at lowering IOP in glaucoma patients, our central hypothesis is that genes involved in Mendelian forms of CODA would also be involved in a subset of glaucoma cases and may provide insight into glaucomatous optic neuropathy. The purpose of my research project has been to identify and functionally characterize the gene that causes congenital autosomal dominant CODA in a multiplex family with 17 affected members. The gene that causes CODA was previously mapped to chromosome 12q14 and following screening of candidate genes within the region that did not yield any plausible coding sequence mutations, a triplication of a 6KB segment of DNA upstream of the matrix metalloproteinase 19 (MMP19) gene was subsequently identified using comparative genomic hybridization arrays and qPCR. This copy number variation (CNV) was present in all affected family members but absent in unaffected family members, a panel of 78 normal control subjects, and the Database of Genomic Variants. In a case-control study of singleton CODA subjects, CNVs were also detected; we detected the same 6KB triplication in 1 of 24 subjects screened. This subject was part of another 3-generation autosomal dominant CODA pedigree where affected members each have the same CNV identified in the larger CODA pedigree. A separate case-control study with 172 glaucoma cases (primary open angle glaucoma = 84, normal tension glaucoma = 88) was evaluated for MMP19 CNVs, however none were detected. Although our cohort of CODA patients is small limiting our ability to accurately determine the proportion of CODA caused by MMP19 mutations, our data indicates that the MMP19 CNV is not an isolated case and additional CODA subjects may have MMP19 defects. Because of the location of the CNV, we evaluated its effect on downstream gene expression with luciferase reporter gene assays. These assays revealed that the 6KB sequence spanned by the CNV in CODA subjects functioned as a transcriptional enhancer; in particular, a 773bp segment had a strong positive influence (8-fold higher) on downstream gene expression. MMP19, a largely understudied gene, was further characterized by expression studies in the optic nerve and retina. Using frozen sections from normal donor eyes, we demonstrated that MMP19 is predominantly localized to the optic nerve head in the lamina cribrosa region with moderate labeling in the postlaminar region, and weak labeling in the prelaminar region and retina. We also evaluated MMP19 expression in relation to the cell types that populate the optic nerve such as astrocytes and retinal ganglion cells. The pattern of expression is consistent with MMP19 being a secreted protein accumulating in the extracellular spaces and basement membranes of the optic nerve. Our studies have identified the first gene associated with CODA and future research is focused on recapitulating CODA phenotypes in animal models and assessing the mechanism of MMP19 involvement during development.