In vertebrates, the embryonic hindbrain is transiently subdivided along its anterior-posterior (A-P) axis into 8 well defined segments termed rhombomeres (r1-8). Each rhombomere represents a true cellular compartment in transcriptional profile, lineage restriction and neuronal organization. Thus, the vertebrate hindbrain provides a beautiful model for studying mechanisms of anterior-posterior patterning, signal transduction and interpretation, initiation and maintenance of transcriptional profiles, cell sorting and border formation. The Kreisler/MafB gene, which encodes a basic leucine zipper (bZIP) transcription factor that regulates some Hox genes, is one of the first genes to be expressed segmentally in the hindbrain, and is subject to a dynamic and complex regulatory process. However, unlike the Hox genes, Kreisler/MafB is not located within a large cluster of genes and therefore provides a simple system for dissecting the molecular mechanisms involved in hindbrain compartmentalization. In dissecting the mechanisms that govern Kreisler/MafB regulation, we have identified the S5 regulatory element that directs early MafB expression in the future r5-r6 domain. We have found a binding site within S5 that is specific for the Variant Hepatocyte Nuclear Factor 1 (vHNF1) to be essential, but not sufficient for early induction of r5-r6-specific expression. Thus, early inductive events that initiate MafB expression are clearly distinct from later acting ones that modulate its expression levels. Using mouse mutants, we have shown that MafB is dependent on the M33 polycomb protein and other mechanisms of chromatin remodeling. We then utilized transgenic flies and mice as well as binding assays to identify and validate a PcG/trxG response element (PRE), PRE1 which acts to reorganize the surrounding chromatin, regulating S5-dependent expression. To our knowledge, PRE1 is the first validated vertebrate PcG/trxG response element. Thus, PRE1 provides a springboard for further exploration of the mechanisms governing chromatin remodeling.

Arterial wall morphology depends strongly on the hemodynamic environment experienced in vivo. The mammalian heart pumps blood through rhythmic contractions forcing blood vessels to undergo cyclic, mechanical stimulation in the form of pulsatile blood pressure and flow. While it has been shown that stepwise, chronic increases in blood pressure and flow modify arterial wall thickness and diameter respectively, few studies on arterial remodeling have examined the influences that pulsatility (i.e., the range of cyclic stimuli) may have on biaxial wall morphology. We experimentally studied the biaxial behavior of carotid arteries from 8 control (CCA), 15 transgenic, and 21 mechanically altered mice using a custom designed mechanical testing device and correlated those results with hemodynamic measurements using pulsed Doppler. In this dissertation, we establish that increased pulsatile stimulation in the right carotid artery after banding (RCCA-B) has a strong affect on wall morphological parameters that peak at 2 weeks and include thickness (CCA=24.8±0.878, RCCA-B=99.0±8.43 μ m), inner diameter (CCA=530±7.36, RCCA-B=680±32.0μ m), and in vivo axial stretch (CCA=1.7±0.029, RCCAB= 1.19±0.067). These modifications entail stress and the change in stress across the cardiac cycle from an arterial wall macro-structural point of view (i.e., cellular and extracellular matrix) citing increases in collagen mass fraction (CCA=0.223±0.056, RCCA-B=0.314±0.011), collagen to elastin ratio (CCA=0.708±0.152, RCCA-B=1.487±0.26), and cross-sectional cellular nuclei counts (CCA=298±58.9, RCCA-B=578±28.3 cells) at 0, 7, 10, 14, and 42 post-banding surgery. Furthermore, we study the biomechanical properties of carotid arteries from a transgenic mouse of Marfan Syndrome. This arterial disease experiences increased pulse transmission and our findings indicate that alterations occur primarily in the axial direction. The above results are all applied to a predictive biaxial model of Cauchy stress vs. strain.

Cerebral vasospasm following subarachnoid hemorrhage has high morbidity and mortality. Mathematical modeling of the progression of the condition provides insight to improve clinical treatment of patients post subarachnoid hemorrhage. An existing model of the clotting cascade is expanded to include the theoretical conditions of cerebral vasospasm. We consider clotting factor XIIIa, which has been implicated as a primary cause of the entrenchment of the smaller diameter. Solutions for clotting are used as boundary conditions to solve the concentration of diffusible clotting factors in the vessel wall and cerebrospinal fluid (CSF). Each domain (clot, vessel wall, CSF) is described by a separate initial-boundary value problem, requiring unique conditions, reaction-diffusion equations, and diffusion coefficients. Additionally, the results from the first domain (the clot) provide a subset of the boundary conditions for the second and third domains (arterial wall and CSF, respectively). Although this approach captures many detailed components of the clotting process, a simpler method for investigating the formation and dissolution of a clot post subarachnoid hemorrhage is to neglect the bulk of the clot cascade to focus on the most salient features, namely, the formation of cross-linked fibrin and the degradation of fibrin by plasmin. By assuming first order kinetics in the initial hours following hemorrhage, we find a simplified expression with kinetic rates that may be adjusted depending on experimental conditions.

Characterization of multiaxial mechanical properties of cardiovascular soft tissue is essential in order to better understand their growth and remodeling in homeostatic conditions and in response to injury or pathological conditions. Though numerous phenomenological models have been proposed to characterize such multiaxial mechanical behavior, the approach has certain drawbacks regarding experimental determination of the model coefficients. We propose a method that aims to overcome these drawbacks. The approach makes use of orthogonal polynomials to fit the biaxial test data and suggests a way to derive the strain energy function from these analytical fits by way of minimizing the deviation of the behavior from hyperelastic ideal. Using the proposed method, a strain energy function for a lymphatic vessel is derived and the method is compared with traditional ones that used non-orthogonal polynomials as independent variables in the functional form for strain energy. The unique coefficient values obtained using the proposed method, for the first time gives us an opportunity to attribute a physical characteristic of the material to the coefficient values. The method also provides a way to assess two different material behaviors by way of comparing their deviation from the hyperelastic behavior when a similar test protocol is used to collect the data, over a similar deformation range and the order of polynomial function is chosen so as to give a similar error of fit. The behavior of mesenteric lymph vessels from normal cows, cows subjected to sham surgery and those subjected to 3 days of edematous conditions by venous occlusion are compared using this method. To be able to better understand the changes in mechanical behavior, morphological analysis of the vessels was carried out and the geometric and structural changes in these vessels were studied. We found that the behavior of bovine mesenteric lymph vessels subjected to a high flow condition shows a small difference in their mechanical behavior as compared to the vessels from normal a cow and a cow subjected to sham surgery. The geometry and structure of these vessels also showed marked differences from the other two. The thickness to radius ratio increased and a rise in percentage of area occupied by smooth muscle cells and medial collagen was observed. Though not all the differences were statistically significant, we conclude that the behavior and the morphology are suggestive of the remodeling of the vessel in response to altered hemodynamic conditions and require further investigation.

published_or_final_version / Urban Planning and Design / Master / Master of Science in Urban Planning

This research serves as a reference not only for persons or organizations intending to propose adaptive re-use of or A&A works to a historical building of Cattle Depot but also for architects, engineers, surveyors, heritage conservationists and designers who are engaged for this type of project as a Youth Hostel. The hypothesis of this dissertation is that there is a high demand for urban youth hostels in Hong Kong and such youth hostels are in critical short supply. This leads to the scope of my dissertation, which is to explore the technical feasibility to adapt a heritage building as an urban youth hostel. After conducting comprehensive desk study and site inspection to the Cattle Depot, the methodology of the study will be based on the various statutory submission stages of adapting a building for a new use. To be more precise, this study will examine the procedures of adaptive reuse in terms of (1) what to do and (2) how and where to get it done in the following three main stages in Planning, Building and Licensing. Last but not least, there would be a way forward of historical building sustainability, to change the more appropriate adaptive reuse as a Cattle Depot Youth Hostel would be more possible as a solution to meet the needs of community and benefit to that district development. More importantly, a number of tangible heritages of the Cattle Depot could make use of these available resources to tell of its story history to the community. / published_or_final_version / Conservation / Master / Master of Science in Conservation

published_or_final_version / Politics and Public Administration / Master / Master of Public Administration

published_or_final_version / Politics and Public Administration / Master / Master of Public Administration

Hong Kong is an international metropolis and “Shopping Paradise”. Therefore, shopping in Hong Kong becomes one of the popular and important customary activities for the people. To compete with the keen and rapid change of market competition and shoppers’ living style and prevent old and deteriorated mall image, it is important for mall owner and operator to upkeep mall’s competitiveness by refurbishment work and repositioning exercises. To examine the repositioning strategies of Shopping Mall in Hong Kong, case study of New Town Plaza would be the selected mall in this research for further evaluation. Face to face interviews were conducted with Shoppers and Tenants respectively regarding their perception of mall image and competiveness attributes, including mall image, shopping environment and accessibility attributes among selected shopping mall-New Town Plaza before and after refurbishment work. At last, it found that mall repositioning exercise had drawn a great influence on different stakeholders. Based on research result, it showed that interviewees generally recognized that brand image of tenants, mall’s image and competiveness were improved after mall refurbishment. Also, more high-ended shoppers were attracted to visit and shop in the mall. As comparing with before refurbishment work, Interviewees were visited more and stayed longer due to its freshness image and modern design. Although mall refurbishment work and repositioning exercise brings lots of positive feedbacks for different stakeholders and extend the product life of the mall, it does not represent such exercise appropriate for applying in all shopping mall. Therefore, mall owner or operator was reminded to take further consideration for planning such work and finally recommendations were suggested for them in considering the repositioning and refurbishment work in the future too. / published_or_final_version / Housing Management / Master / Master of Housing Management

Shopping centers is vital in our daily life. In this paper, the importance of provision of entertainments will be analyzed in details and this would be useful for owners or management companies of shopping malls if they are planning for renovations or implementing new shopping malls. Six research questions are analyzed in this paper through conducting surveys through questionnaires, and they will be categorized into two categories, which is to determine the impact of entertainments to the success of the shopping malls and to determine the impact of the various means of entertainments to the success of the shopping malls. Convenience sampling is adopted for the data collection of questionnaires and two sets of questionnaires will be distributed only to people who lives or works in Tsuen Wan and have ever visited all of the shopping malls used for case study, that is CityWalk, Tsuen Wan Plaza and Emperor Plaza. After performing the detailed data analysis, it is found out that most people think that provision of entertainments is an important factor that affects people’s decision to visit and shop in the shopping centers, but this factor is not as crucial as factors like location, variety of shops and provision of open spaces. Also, this factor is important to both the newly-built shopping centers and renovated old shopping centers. Also, it is found out that differences in age groups and genders may have variations in determining the importance of provision of entertainments in general for the individual’s shopping preference. Young people relatively regarded provision of entertainments as more important factor that affect people’s decision, when compared to older people. Male also regard provision of entertainments as more important than female. Differences in age groups and genders may also show different priorities for the importance of each means of entertainments in shopping centers. Hence, we have to know the target group of the customers and to invest suitable means of entertainments or otherwise, the shopping centers cannot sustain with a high profit. For example, since there are more old people than the young people in Tsuen Wan, it is not practicable to invest a large sum of money on provision of means of entertainments which cater for the young and male more, such as the video game counters. However, it is always recommended to include the means of entertainments like the cinemas, fitness and spa centers and toy shops as investments from the owners or the management companies of the shopping centers towards these means of entertainments is relatively small, when comparing to other means of entertainments. / published_or_final_version / Housing Management / Master / Master of Housing Management