by Ling Kai Tung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 44-45). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.7 / Chapter 2 --- Fundamentals --- p.9 / Chapter 2.1 --- Digital image representation --- p.9 / Chapter 2.2 --- Motion Blur --- p.13 / Chapter 3 --- Methods for Solving Nonlinear Least-Squares Prob- lem --- p.15 / Chapter 3.1 --- Introduction --- p.15 / Chapter 3.2 --- Nonlinear Least-Squares Problem --- p.15 / Chapter 3.3 --- Gauss-Newton-Type Methods --- p.16 / Chapter 3.3.1 --- Gauss-Newton Method --- p.16 / Chapter 3.3.2 --- Damped Gauss-Newton Method --- p.17 / Chapter 3.4 --- Full Newton-Type Methods --- p.17 / Chapter 3.4.1 --- Quasi-Newton methods --- p.18 / Chapter 3.5 --- Constrained problems --- p.19 / Chapter 4 --- Reconstruction of High-Resolution Images from Movie Frames --- p.20 / Chapter 4.1 --- Introduction --- p.20 / Chapter 4.2 --- The Mathematical Model --- p.22 / Chapter 4.2.1 --- The Discrete Model --- p.23 / Chapter 4.2.2 --- Regularization --- p.24 / Chapter 4.3 --- Acquisition of Low-Resolution Movie Frames --- p.25 / Chapter 4.4 --- Experimental Results --- p.25 / Chapter 4.5 --- Concluding Remarks --- p.26 / Chapter 5 --- Constrained Total Least-Squares Computations for High-Resolution Image Reconstruction --- p.31 / Chapter 5.1 --- Introduction --- p.31 / Chapter 5.2 --- The Mathematical Model --- p.32 / Chapter 5.3 --- Numerical Algorithm --- p.37 / Chapter 5.4 --- Numerical Results --- p.39 / Chapter 5.5 --- Concluding Remarks --- p.39 / Bibliography --- p.44

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Helical assemblies of proteins are ubiquitous in nature and they perform vital functions in a wide range of organisms. The recent development of direct electron detectors and other imaging techniques in cryo-electron microscopy (cryo-EM) has opened new possibilities in solving helical structures at atomic resolution. Existing software packages for helical processing often require experience in tuning many ad hoc parameters to achieve optimal reconstruction results. REgularised LIkelihood OptimisatioN (RELION), an open-source single-particle analysis package, reduces the need for user expertise by the formulation of an empirical Bayesian framework, and has yielded some of the highest resolution density maps in recent years. Prior information about the helical assemblies can be conveniently incorporated into the statistical framework of RELION and thereby improves the helical reconstructions. This PhD thesis describes the development of a helical processing computation workflow with reduced user intervention in RELION. Chapter 1 introduces the theoretical basis of cryo-EM data acquisition and single-particle data processing, the concepts of helical symmetry, and a previously described method for iterative real-space reconstruction of helical assemblies, to which the RELION implementation bears resemblance. Chapter 2 discusses multiple adaptations to RELION that are necessary for helical processing. Key elements include the imposition and local refinement of helical symmetry, masks on helical segments and references, expressions of angular and translational prior information, manual and automated segment picking as well as initial model generation for helices. Calculations have been performed on four test data sets showing that the developed methods in RELION yield results that are as good as or better than alternative approaches for the tests performed. Chapter 3 describes the same methodology adapted to helical sub-tomogram averaging in RELION. Chapter 4 introduces the local symmetry option developed for special types of filaments with pseudo-helical symmetry. The concept can be extended to general single-particle analysis as well. Chapter 5 describes four helical structures determined in collaboration with other research groups using helical RELION for data processing. Chapter 6 concludes the thesis with a brief summary and future prospects.

Chung, Hin Shun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 40-43). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Lambertian photometric stereo --- p.1 / Chapter 1.2 --- Non-Lambertian photometric stereo --- p.3 / Chapter 1.3 --- Large specular lobe problems --- p.4 / Chapter 2 --- Related Work --- p.9 / Chapter 2.1 --- Lambertian photometric stereo --- p.9 / Chapter 2.2 --- Non-Lambertian photometric stereo --- p.9 / Chapter 2.2.1 --- Analytic models to reconstruct non-Lambertian surface --- p.9 / Chapter 2.2.2 --- Reference object based --- p.10 / Chapter 2.2.3 --- Highlight removal before shape reconstruction --- p.11 / Chapter 2.2.4 --- Polarization based method --- p.12 / Chapter 2.2.5 --- Specularity fitting method --- p.12 / Chapter 2.2.6 --- Photometric stereo with shadow --- p.12 / Chapter 3 --- Our System --- p.13 / Chapter 3.1 --- Estimation of global parameters --- p.14 / Chapter 3.1.1 --- Shadow separation --- p.16 / Chapter 3.1.2 --- Separation edges of shadow and edges of foreground object --- p.16 / Chapter 3.1.3 --- Normal estimation using shadow boundary --- p.20 / Chapter 3.1.4 --- Global parameter estimation and refinement --- p.22 / Chapter 3.2 --- Surface shape and texture reconstruction --- p.24 / Chapter 3.3 --- Single material results --- p.25 / Chapter 4 --- Comparison between Our Method and Direct Specularity Fitting Method --- p.29 / Chapter 4.1 --- Summary of direct specularity fitting method [9] --- p.29 / Chapter 4.2 --- Comparison results --- p.31 / Chapter 5 --- Reconstructing Multiple-Material Surfaces --- p.33 / Chapter 5.1 --- Multiple material results --- p.34 / Chapter 6 --- Conclusion --- p.38 / Bibliography --- p.39 / Chapter A --- Proof of Surface Normal Projecting to Gradient of Cast Shadow Boundary --- p.43

Obtaining high spatial or spatiotemporal resolution along with good slice coverage is challenging in dynamic magnetic resonance imaging, MRI, due to the slow nature of the acquisition process. In recent years, there has been a rapid growth of MRI techniques that allow faster scan speed by exploiting spatial or spatiotemporal redundancy of the images. These techniques can improve the performance of imaging significantly across multiple clinical applications, including cardiac functional examinations, perfusion imaging, blood flow assessment, contrast-enhanced angiography, functional MRI, and interventional imaging, among others. The ultimate goal of this thesis is to develop novel algorithms to reconstruct heavily undersampled sparse imaging. The designed schemes aim to achieve a shorter scan duration, higher spatial resolution, increased temporal resolution, signal-to-noise ratio and coverage in multidimensional multichannel MRI. In addition to improving patients comfort and compliance while imaging under the MRI device, the newly developed schemes will allow patients with arrhythmia problems, pediatric and obese subjects to breath freely without the need for any breath-hold scans. Shortening examination periods also reduces patient's stress, lowers the entire visit to the clinic and finally decreases the associated economic costs. Rapid imaging acquisitions will also allow for efficient extraction of quantitative information needed for the patients' diagnosis eg. tumor characterization and veins blockages through myocardial perfusion MRI. Current applications of interests include real-time CINE MRI and contrast changing perfusion MRI.

In 2011, a landslide displaced approximately six thousand people from the urbanized mountain slopes of La Paz, Bolivia. The municipal government of La Paz (GAMLP) managed the displacement by housing thousands of people in displacement camps throughout the city. By 2013, residents were attempting to return to still damaged lands. This research used participant observation and interviews with residents over eight weeks in 2013 to address the following questions: 1) What social, cultural, economic or historic factors influence the settling and then resettling of at-risk slope neighborhoods in La Paz, Bolivia? 2) What are the most pressing health needs of people who have returned to slope neighborhoods and people still living in displacement camps? The research found that the return to at-risk slope properties was supported by entrenched cultural and social meanings attached to land and home ownership. While scarcity of resources galvanized communities to pressure authorities with demonstrations and threats, it also created intra-barrio frictions that disrupted reconstruction, strained existing infrastructure capabilities and threatened to undermine community health.

While in agreement with the perceived wisdom that events during World War Two were responsible for many social changes for women in Australia, the thesis disagrees with the implication in existent Queensland women’s historiography that these changes affected women equally in all parts of the State. Research undertaken in Central Queensland provides evidence that, although some similarities existed, the conservative forces in this region restricted the liberating effect of such changes. It also addresses the subject of Queensland difference, and argues that the rural patriarchal economy sustained the notion of rigid gender and class differences in Central Queensland. It maintains that this affected women in regional Queensland to a far greater extent than those in the Brisbane metropolitan area because of the lack of secondary wartime industry and the masculine nature of rural industry. Additionally , in opposition to the widely held belief there was universal post-war financial security the thesis argues that poverty did exist. In particular it addresses the subjects of rising inflation and what has been termed the Social Security Poverty Group, basing conclusions on statistical evidence, oral evidence, and secondary and documentary sources.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.