This thesis explores the historic preservation projects in two cities: Suzhou, China, and Pasadena, California, United States. The purpose of investigating the strategies and policies used in each of the historic districts is to discuss whether preservation strategies applied in both cases could represent historic authenticity. The first two chapters focus on the project plan of the two historic districts. By evaluating the preservation policies at both national and regional level, histories of the districts, and approaches adopted by two cities, this thesis discerns the different perceptions of “authenticity” in preservation strategies in two countries. The next part of the thesis compares the two historic districts in terms of their distinctive focuses on preservation approaches. I, therefore, conclude that even though both cases have been deemed as successful models of preservation projects in each country, both historic district has demonstrated different levels of insufficient protection in culture and social sustainability.

De nombreux agents chimiothérapeutiques sont gonadotoxiques et peuvent donc induire une insuffisance ovarienne précoce chez les jeunes patientes traitées. La protection pharmacologique de l'ovaire pendant la chimiothérapie à l'aide d'analogues de la Gonadotropin-Releasing Hormone (GnRHa) est une option intéressante de préservation de la fertilité de par son caractère non-invasif et la possibilité d’une récupération spontanée de la fonction ovarienne. Ces molécules sont des inhibiteurs bien connus de l'axe hypothalamo-hypophyso-gonadique, mais leur efficacité dans cette indication est, cependant, controversée et leurs mécanismes d'action sont mal compris. Par conséquent, nous avons investigué les mécanismes potentiels de protection ovarienne des GnRHa pendant la chimiothérapie sur modèle murin. Nous avons montré que le cyclophosphamide (Cy) induit une déplétion folliculaire aiguë et proportionnelle à la dose affectant à la fois les follicules quiescents et en croissance. Lorsqu'ils sont administrés seuls à différentes doses et sites, l'agoniste et l'antagoniste de la GnRH altèrent les cycles oestraux, mais ne bloquent ni la folliculogenèse ni la sécrétion de la Follicle-Stimulating Hormone (FSH) chez la souris. De plus, le Cy atteint les follicules primordiaux, que les souris aient été traitées avec les GnRHa ou non. Ces résultats suggèrent que les GnRHa n'inhibent pas l'axe hypophyso-gonadique aussi efficacement chez la souris que chez la femme. Par conséquent, nous avons développé de nouveaux modèles pour étudier les mécanismes potentiels de protection ovarienne des GnRHa. Afin de différencier les effets directs des GnRHa via leurs récepteurs ovariens ou indirects par inhibition de la sécrétion de gonadotrophines, l'effet de l'agent alkylant sur le développement folliculaire et la réserve ovarienne a été testé sur des follicules cultivés in vitro avec ou sans GnRHa et in vivo chez des souris déficientes en FSHb (Fshb-/-). Pour imiter la profonde inhibition de FSH observée chez la femme après traitement aux GnRHa, nous avons étudié la toxicité de la chimiothérapie chez les souris Fshb-/-. L’administration de gonadotrophines exogènes (pregnant mare serum gonadotropin, PMSG) induit une croissance folliculaire jusqu’au stade antral mais n’influence pas le nombre total de follicules au sein de l’ovaire. Le Cy induit une perte folliculaire significative dans le groupe contrôle et dans le groupe traité au PMSG. Aucune différence concernant la prolifération ni l'apoptose n'a été observée entre les groupes traités à la chimiothérapie. A ce jour, ce modèle murin représente le meilleur modèle pour étudier l'inhibition gonadotrope induite par les GnRHa observée chez la femme. Ces résultats suggèrent que la FSH n'est pas impliquée dans la protection ovarienne potentielle des GnRHa pendant la chimiothérapie. Afin d’évaluer les effets directs des GnRHa sur les follicules en croissance et quiescents, des follicules préantraux ou des ovaires de nouveau-nés (PND4) ont été cultivés avec ou sans GnRHa avant l'exposition au métabolite actif du Cy, le 4-hydroperoxycyclophosphamide (4HC). Nous avons d'abord montré que l'exposition in vitro aux GnRHa n'affectait ni la survie et le développement folliculaire, ni la maturation ovocytaire. Dans les follicules en croissance, le 4HC diminue significativement les taux de survie et de maturation; et retarde le développement folliculaire, indépendamment du traitement aux GnRHa. La chimiothérapie diminue le nombre de cellules de la granulosa par follicule tandis que la production d’adénosine monophosphate cyclique (AMPc) par million de cellules de la granulosa n'est pas modifiée, ni par le 4HC, ni par les GnRHa. La sécrétion d'oestradiol tend à être retardée dans le groupe traité à l’agoniste mais pas dans le groupe antagoniste. De même, dans les ovaires PND4, le 4HC induit une perte folliculaire importante et atteint directement les cellules de la granulosa des follicules ovariens. Aucune différence dans la distribution folliculaire, la prolifération ou l'apoptose n'a été observée entre les groupes traités avec le 4HC, peu importe la présence des GnRHa ou non. Pour conclure, en se basant sur des modèles murins robustes et originaux, notre travail remet en question l'efficacité des GnRHa pour préserver l'ovaire contre les dommages causés par la chimiothérapie que ce soit par une action directe sur l'ovaire, ou indirectement par l'absence de FSH. D'autres investigations seront nécessaires pour comprendre les mécanismes d'action potentiels des GnRHa sur l'ovaire et les voies impliquées. Des preuves expérimentales sont encore indispensables pour clore le débat sur cette option attrayante de préservation de la fertilité. / Doctorat en Sciences biomédicales et pharmaceutiques (Médecine) / info:eu-repo/semantics/nonPublished

M.Sc. (Botany) / Please refer to full text to view abstract

Magister Scientiae - MSc / This thesis deals with analysis and implementation of a positivity preserving numerical method for a vaccination model for the transmission dynamics of two HIVsubtypesnin a given community. The continuous model is analyzed for stability and equilibria. The qualitative information thus obtained is used while designing numerical method(s). Three numerical methods, namely, Implicit Finite Difference Method (IFDM), Non-standard Finite Difference Method (NSFDM) and the Runge-Kutta method of order four (RK4), are designed and implemented. Extensive numerical simulation are carried out to justify theoretical outcomes

Please read the abstract in the 00front part of this document / Dissertation (MSc (Food Science))--University of Pretoria, 2007. / Food Science / unrestricted

Kafirin, the prolamin protein of sorghum grain, could be extracted from the by-products of the sorghum processing industry and used to make films and coatings for food packaging, in particular to extend the shelf-life of fruits and nuts. Protein-based films can be an environment-friendly alternative to synthetic plastic packaging systems. However, the properties of protein-based films are generally inferior to those of synthetic plastics. Modification can alter the properties of protein-based films. In this project, the interaction between phenolic compounds and kafirin was investigated in relation to their potential to modify kafirin films. A range of phenolic compounds was tested in terms of their ability to bind and complex with kafirin in an in vitro binding assay. The protein-phenolic compound interaction was quantified by haze formation and colorimetric determination of total polyphenol bound. Ferulic acid, catechin and extracted flavonoids from condensed tannin-free sorghum did not complex with kafirin. Tannic acid (TA) and sorghum condensed tannins (SCT) complexed kafirin and formed haze. Thus, T A and SCT were selected as potential modifying agents for kafirin films. TA and SCT were added at up to 20% (w/w tannin to protein basis) during kafirin film casting. Both TA and SCT bound to kafirin in the film. Scanning electron microscopy showed that TA modified films were less porous; and the SCT modified films appeared more globular in structure than unmodified film. Modification with both tannins increased the tensile stress and Young's modulus and decreased the tensile strain of the kafirin films. Oxygen permeability of the modified films was decreased, but no change in the apparent water vapour permeabilty. The T9 of the films increased with increased modification level. SOS-PAGE, FT-IR and Raman spectroscopy were used to study TA and SCT interaction with kafirin. SOS-PAGE revealed a high Mr band for kafirin-SCT complexes which did not enter the separating gel. FT-IR of kafirin complexed tannins and tannin modified films showed a decrease in the absorbance at the frequency of about 1620 cm-1, suggesting a decrease in â-sheet structures. FT-IR results also suggested that the â-sheets of kafirin in dry form were probably changed into random coils during kafirin dissolution to make films. Raman spectra showed a shift in the TA peak at about 1710 cm-1 to about 1728 cm-1 in the kafirin- TA complexes, suggesting participation of the carbonyl groups of TA in TA-kafirin interaction. It is proposed that hydroxyl groups of tannin can form hydrogen bonds with carbonyl groups of random coils of kafirin during film casting. Thus, the carbonyl groups are probably not available to be reorganized into â-sheets. The other possible mode of interaction can be hydrophobic interaction between the aromatic rings of tannins and the pyrrolidine rings of proline. Because tannins have numerous aromatic rings with hydroxyl groups, it is also proposed that they can bind with more than one polypeptide chain at the same time to cross-link kafirin. This cross-linking probably produces a high Mr kafirin-tannin complex that leads to haze. The cross-linking would also lead to lower molecular mobility of modified kafirin films. This could decrease oxygen permeability, probably as a result of decreased free volume. Cross-linking could also be responsible for the increased tensile stress and decreased tensile strain of modified kafirin films. The higher tensile stress of modified• kafirin films suggests that they can have the potential to form stronger coatings around fruit such as litchi fruit to possibly reduce pericarp microcracking as an example, and thus may reduce the pericarp browning of litchi. The lower oxygen permeability of the modified films and the potential antioxidant activity of the tannins suggest that these films can be a good coating to prevent rancidity of nuts. / Thesis (PhD (Food Science))--University of Pretoria, 2006. / Food Science / unrestricted

Animal hides are the basic raw material of the leather industry and they undergo rapid putrefaction unless "cured". This study investigated the role and interactive effects of three selected bacteria, Pseudomonas aeruginosa. Clostridium histoly ticum and Clostridium sporogenes in in-situ cattle hide degradation using a model system set up for the purpose. The system consisted of 3cm diameter hide pieces contained in sealed jars and sterilised by ethylene oxide to remove resident microbes and inactivate autolytic tissue enzymes. The inocula were prepared either as individual cultures or as combinations of two inocula or all three inocula. Degradative changes during storage at 30°C were measured for up to 8 days using ten different parameters. Initial trials confirmed that the selected inocula were readily isolated from raw hides and could outcompete resident populations to produce putrefactive decomposition. Growth rates and enzyme profiles of the organisms and the effects of nutrients and reductants on their relative denaturative effects were used to standardise the system. Trials on the effects of ethylene oxide indicated the suitability of the method for hide and collagen sterilisation. The findings of in-situ trials with the selected inocula confirmed previous studies of protein putrefaction in that a bacterial succession was evident involving aerobic proteolytic bacteria, micro-aerophilic proteolytic bacteria and strictly anaerobic amino acid degrading bacteria. However, this study showed that the micro-aerophilic collagenase producing C. histolyticum degraded hides at a far greater rate when inoculated on its own than when in the presence of either or both of the other two inocula. It also demonstrated a bacterial antagonism between the two clostridia in which C. sporogenes prevented degradative changes occurring for up to 4-6 days possibly due to cysteine production by C. sporogenes. These findings have implications for hide preservation since maintenance of aerobic conditions and suppression of spore outgrowth could be used to delay growth of collagenase producing clostridia. The use of C. sporogenes as a biocontrol agent is also postulated. The model system was also used to examine salted hides during storage and these studies indicated that Halobacteriaceae do not produce collagenase but that inadequately salted hides could possibly be subject to degradation by delsulfovibrios.

This dissertation research examines how shared aspects of identity are constructed among the Druze in Lebanon and how it contributes to conceptualizations of heritage. Assessing the educational resources focused on aspects of Druze heritage, the barriers to cultural preservation were elucidated. Utilizing a number of qualitative research methods, participants’ feedback constructed a narrative that considers what they believe to be at risk for their community. These issues included addressing a perceived knowledge gap wherein the majority of Druze expressed a need to expand the educational resources in their community. Participants defined the kinds of resources and social supports that are lacking and explained how existing texts, lectures, and seminars should be improved, increased, and made more accessible. This dissertation is a result of ethnographic fieldwork which I conducted throughout 2014. Having lived in the town of Aley, Lebanon, I conducted research interviews with individuals that represented a broad spectrum of society, taking into account women and men of different ages with diverse social, economic, and educational backgrounds. Through participant observation, I shared many of the daily experiences of research participants and observed the Druze in their regular lives, their social gatherings, and at sites of historical significance. Using a political economic theoretical framework, this research also explored the diversity of ways in which social phenomena are contested among the Druze in Lebanon. While much of the anthropological and social science research on heritage focuses on its material components, utilizing pre-established models that conflate heritage with tangible symbolic expressions, a political economic approach insists that the context of social structures are taken into account. This also lends itself to a conceptualization of heritage as a process by which individuals create meaning in their lives, which are shaped by social contexts such as history and contemporary culture. This research highlights the fact that a priori models that fail to consider both social structures and the fundamental perspectives of participants are based upon ideologies that lack a critical academic lens. This dissertation demonstrates that while Druze particularism often necessitated a level of conformity and ascription to traditional values, the diversity of individual approaches to shared identity contributed to the plasticity of cultural forms and varieties of self-expression. As well, expanded and improved educational resources that encourage individuals to learn more about their history and the basic tenets of their faith were widely seen as a valued means of ensuring the society’s continuation.

This study used cross-sectional survey data to estimate farmers` perceptions of, and commonly cultivated ILVs, factors that influence the participation of smallholder famers in the production of Indigenous Leafy Vegetables and its contribution to household food security]. With regard to farmers` perceptions of ILVs, descriptive results reveal that a majority of the people from the study area share positive perceptions with respect to ILVs. Regression estimates for determinants of participation indicate that the production of ILVs is primarily conditioned by shared perceptions and institutional factors rather than the socio-economic attributes of farmers. Public policies that address the institutional framework (extension, credit, market and social networks) in favour of ILVs are more likely to promote production. Also, more research on the documentation and benefits of ILVs, supported by investments targeting educational campaigns towards promoting positive attitudes and dispelling fears and myths surrounding ILVs, will further promote production. With reference to the contribution of ILVs to food security, descriptive results indicate that participation in the production of ILVs leads to a higher HDDS and a lower HFIAS. Regression estimates further revealed that participation positively contributes to a higher HDDS and a lower HFIAS, suggesting that households who participate in the production of ILVs are more likely to be food secure than non-participants. Therefore, participation in the production of ILVs has significant potential to address household food security.

In binaural hearing aids, several beamforming algorithms can be used. These beamformers aim to enhance the target speech signal and preserve the binaural cues of the target source (e.g. with constraints on the target). However, the binaural cues of the other directional sources as well the background noise are often lost after processing. This affects the global impression of the acoustic scene, and it limits the perceptual separation of the sources by the hearing aids users. To help the hearing aids users to localize all the sound sources, it is important to keep the binaural cues of all directional sources and the background noise. Therefore, this work is devoted to find the best trade-off between the noise/interferers reduction and the cues preservations not only for the directional interferers but also for the background noise based on selection and mixing processes. In this thesis, some classification decision algorithms, which are based on different criteria such as the power, the power difference, and the coherence, are proposed to complete the selection and mixing processes. Simulations are completed using recorded signals provided by a hearing aid manufacturer to validate the performance of the proposed algorithm under different realistic acoustic scenarios. After detailed testing using different complex acoustic scenarios and different beamforming configurations, the results indicate that some of the proposed classification decision algorithms show good promise, in particular the classification decision algorithm based on coherence.