Thèse--Faculté de medecine de Paris. / "Index bibliographique": p. [45]-47.

Halle, University, Diss., 2001.

Suburban Heights is a novella and collection of stories.

This is an account of some aspects of the ecology of the eastern Cape rocky, Sandelia bainsii Castelnau in the Tyume river in the eastern Cape. Previous unpublished work carried out by the Zoology Department of the University of Fort Hare in the mid-seventies indicated that the species was rare in the Tyume river. Because of its uncertain conservation status, its restricted geographic distribution and the lack of information on its biology, demography, feeding and reproductive biology were studied. The species occurs in the upper, middle and lower reaches of the Tyume river and is common in rocky , shallow habitats in the middle reaches of the system. The most important threats to the survival of S. bainsii appear to be habitat alteration and alien species. The presence of these threats and the small size of the population suggest that the species may be vulnerable to local extinction. As the total range of the species extends to only a few rivers in the eastern Cape, the species might face extinction if these threats are faced throughout its range. A detailed study on the autecology of S. bainsii was therefore carried out in order to provide a basis for rational conservation and management of the remaining populations of the species.The age structure and the growth rate of S. bainsii was determined using checks on scales and otoliths. Males grow faster and reach a larger size than females. The maximum length of S. bainsii is compared to that of other anabantids. The longevity of males is 5 years and that of females 3 years. Food preferences were determined by three different methods and the indices of relative importance of food items calculated for different length groups and seasons. S. bainsii was found to be an euryphagous and opportunistic predator whose diet consists largely of insects. A considerable overlap was found between the diet of S. bainsii and that of the two alien species, Salmo gairdneri and Micropterus salmoides which indicates a possibility of competition for food. Mark and recapture experiments showed that S. bainsii is a "sedentary " species which is unlikely to be seriously affected by man-made barriers to fish migration, such as weirs. The species reaches maturity during its second growing season (males 80 - 89mm and females 60 - 69mm) and the length at maturity is related to the modal length of males and females. A large proportion of the fish are thus mature at any given time. The fish spawn repeatedly during the summer breeding season, October to February resulting in near continuous recruitment. The possible adaptive value of this habit is discussed. An attempt is made to evaluate the life history style of S. bainsii in terms of the theory of r - and K- selection and altricial and precocial life history styles

No description available.

By designing a school for 'La Tarantella', I sought to explore how architecture could meaningfully surround the circular movements of the dancers while imagining how elements of the building could also express energy, rhythm, balance, and harmony. The body/column analogy, the question of cultural and architectural origins, and the myth of the Ancient Cretan labyrinth led me to the creation of a modern labyrinth. / Master of Architecture

The leakage flow through straight through labyrinth seals with tooth on stator was investigated by performing CFD simulations .ANSYS Fluent is used to simulate the fluid flow through straight through Labyrinth seals. The effect of seal geometry on discharge coefficient, carry over coefficient and expansion factor is studied by varying clearance, pitch, tooth height, tooth width ,Reynolds number and rotor speed. Derived quantities Such as carry over coefficient, coefficient of discharge and expansion factor are analyzed as a function of the tooth with preceding cavity to predict the effectiveness of the seal. To understand the effect of varying seal geometries and swirl, 2D CFD simulations were performed. It was found that the clearance to pitch ratio is a strong geometry factor which affect the performance of the seal. The carryover coefficient which describes the portion of kinetic energy carried over from one cavity to the next is also examined. It was found to be a function of Reynolds number and shaft speed. Discharge coefficient describes the losses which occur when fluid flows through the cavity and under the tooth. Just like the carryover coefficient, it is also discovered that it is a strong function of Reynolds number and shaft speed.

A combination of 3-D and 2-D computational fluid dynamics (CFD) modeling as well as experimental testing of the labyrinth seal with hexagonal honeycomb cells on the stator wall was performed. For the 3-D and 2-D CFD models, the hexagonal honeycomb structure was modeled using the concept of the baffle (zero-thickness wall) and the simplified 2-D fin, respectively. The 3-D model showed that even a small axial change of the tooth (or honeycomb wall) location, or a small circumferential change of the honeycomb wall location significantly affected the flow patterns and leakage characteristics especially for small tooth tip clearance. Also, the local details of the flow field were investigated. The seven basic procedural steps to develop a 2-D axisymmetric honeycomb labyrinth seal leakage model were shown. Clearly demonstrated for varying test conditions was the 2-D model capability to predict the 3-D honeycomb labyrinth flow that had been measured at different operating conditions from that used in developing the 2-D model. Specifically, the 2-D model showed very close agreement with measurements. In addition, the 2-D model greatly reduced the computer resource requirement needed to obtain a solution of the 3-D honeycomb labyrinth seal leakage. The novel and advanced strategy to reduce the turbine ingress heating, and thus the coolant requirement, by injecting a “coolant isolation curtain” was developed numerically using a 3-D CFD model. The coolant isolation curtain was applied under the nozzle guide vane platform for the forward cavity of a turbine stage. Specifically, the isolation curtain serves to isolate the hot mainstream gas from the turbine outer region. The effect of the geometry change, the outer cavity axial gap clearance, the circumferential location of the injection curtain slot and the injection fluid angle on the ingress heating was investigated. Adding the chamfer to the baseline design gave a similar or higher maximum temperature T* max than did the baseline design without chamfer, but implementation of the injection curtain slot reduced substantially T* max of the outer region. In addition, a more desirable uniform adiabatic wall temperature distribution along the outer rotor and stator surfaces was observed due to the presence of the isolation curtain.

published_or_final_version / Biochemistry / Doctoral / Doctor of Philosophy

Sox2, a HMG box transcription factor, is well known for its role in stem cell maintenance, iPS (induced pluripotent stem cell) induction, and development of neural tissues such as central nervous system and sensory organs. Sox2 has been demonstrated to be essential for the development of inner ear sensory patches. It has been shown that Sox2 is under the regulation of multiple regulatory elements to obtain a tissue specific manner. Two allelic mouse mutants, yellow submarine (Ysb) and Light coat and circling (Lcc) show hearing and balance impairments with different severity. They were made by random insertions of a transgene (pAA2) and X-ray irradiation respectively. Ysb and Lcc are both localized to chromosome 3 and involve complex chromosomal rearrangements. The Sox2 coding region is intact in the mutants, while the Sox2 expression in the otocyst is greatly reduced in Ysb and totally lost in Lcc, which indicates the tissue specific reduction of Sox2 may be due to the rearrangement of Sox2 regulatory element(s). Since Sox2 null mutants die before implantation, the two Sox2 inner ear mutants are valuable models for studying Sox2 knock down (Ysb) and Sox2 knock out (Lcc) condition in the inner ear. To understand the molecular basis behind Sox2 regulation in the inner ear, this project aims to identify the Sox2 otic regulatory elements, and potential Sox2 downstream targets involved in the development of inner ear. Previous work has indicated that Nop1 and Nop2 are the otic specific regulatory elements of Sox2 in chicken ear. In this project, transgenic mice were generated using Nop1-Nop2, and the result showed Nop1-Nop2 could drive Sox2 expression to the dorsal side of the otiv vesicle, which is different from the endogenous Sox2 expression pattern. Therefore, Nop1 and Nop2 may require other regulatory element(s) to gain a correct regulatory pattern. BAC(RP23-335P23), which contained the DNA sequences close to Ysb integration site 1 was also been tested in transgenic mice. Interestingly, the result showed that BAC(RP23-335P23) could drive Sox2 expression to the ventral side of the otic vesicle, indicating that this BAC may contain the Sox2 otic regulatory element(s). In this project, the binding relationship between Sox2 protein and Math1 enhancer has also been identified using chromatin immunoprecipitation (Ch-IP). Results showed that Sox2 could bind to Math1 enhancer A in the inner ear cochlea. So Sox2 may regulate Math1 through binding to Math1 enhancer A in inner ear development. Using a bioinformatics approach, potential Sox2 target genes in inner ear development have been identified from public microarray data on E9 to E15 inner ear tissue by the presence of conserved Sox2 binding sites. Among these potential targets, 4 genes (Itga6, Erbb3, Sox10 and Mycn) have been selected based on their known functions. Their expression patterns in the cochlea of wild type, Ysb and Lcc were verified. The identification of Sox2 downstream target genes using a bioinformatics approach will help us to understand the molecular basis of Sox2 regulation, and also understand the role of Sox2 in the inner ear development. / published_or_final_version / Biochemistry / Master / Master of Philosophy