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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Computational Modeling of RNA Replication in an RNA World

Tupper, Andrew January 2020 (has links)
The biology of modern life predicts the existence of an ancient RNA world. A phase of evolution in which organisms utilized RNA as a genetic material and a catalyst. However, the existence of an RNA organism necessitates RNA’s ability to self-replicate, which has yet to be proven. In this thesis, we utilize computational modeling to address some of the problems facing RNA replication. In chapter 2, we consider a polymerase ribozyme replicating by the Qβ bacteriophage mechanism. When bound to a surface, limited diffusion allows for survival so long as the termination error rate is below an error threshold. In Chapter 3, we consider the replication of short oligomers through an abiotic mechanism proposed in prebiotic experiments. When limited by substrate availability, competition results in the emergence of uniform RNA polymers from a messy prebiotic soup containing nucleotides of different chirality and sugars. In chapter 4, we consider the possibility of an RNA world lacking cytosine. Without cytosine, the ability of RNA to fold to complex secondary structures is limited. Furthermore, G-U wobble base pairing hinders the transfer of information during replication. Nevertheless, we conclude that an RNA world lacking cytosine may be possible, but more difficult for the initial emergence of life. In chapter 5, we analyze abiotic and viral mechanisms of RNA replication using known kinetic and thermodynamic data. While most mechanisms fail under non-enzymatic conditions, rolling-circle replication appears possible. In chapter 6, we extend our analysis of the rolling-circle mechanism to consider the fidelity of replication. Due to the thermodynamic penalty of incorporating an error, rolling-circle replication appears to undergo error correction. This results in highly accurate replication and circumvents Eigen’s paradox. Rolling-circle replication therefore presents an appealing option for the emergence of RNA replication in an RNA world. / Thesis / Doctor of Philosophy (PhD)
12

Consumer Attitudes Toward Cross-Border Brand Alliances: Adding A Consideration Of Country Of Origin Fit

Carter, Larry Lee Jr. 29 April 2002 (has links)
This research examines the growing phenomenon of cross-border brand alliances and the potential factors that influence consumers' attitudes toward these alliances. Building on an existing framework, it establishes country of origin fit as a new variable that influences consumer attitudes toward brand alliances and examines its relationship with brand fit under various conditions of brand familiarity. The results of two studies replicate previous research findings and demonstrate a new relationship between country of origin fit and brand fit in predicting consumer attitude towards cross-border brand alliances. These results extend research in understanding the relationship between the fit variables and the strength of their effects on brand alliance evaluations. / Master of Science
13

Ochrana označení původu výrobků v českém právu a v mezinárodních úmluvách / Protection of the appellation of origin under Czech law and international treatis

Ambrož, Vladimír January 2013 (has links)
Protection of the appellation of origin under Czech law and international treaties This thesis deals with the topic of appellation of origin. Appellation of origin is governed by Czech law, European Union law and by international multilateral and bilateral treaties. Appellation of origin is an exceptional measure because it provides an indefinite number of users meeting prescribed conditions with protection. The paper is divided into four chapters. The first chapter deals with history and with theoretical introduction into the topic of appellations of origin. Following three chapters describe the protection in the Czech Republic, European Union and on the international level. There are examples of concrete appellations of origin at the end of each of these three chapters. The examples are used in order to better demonstrate different ways of possible use of the appellations of origin. The work uses legal enactments as well as administrative and court decisions. Specialized publications and opinions of some of the users are used as well. The core of legal regulations governing appellations of origin in many countries is formed by multilateral international treaties. This applies also in case of the Czech Republic and the European Union. Application for registration of an appellation of origin may be filled...
14

EU Origin Marking : - A Study of Swedish Meat Consumers

Klint, Olle, Löfström, Patrik January 2005 (has links)
The incentive to investigate the origin of meat products and their related consumer atti-tudes have shown to be a serious and debated topic especially after receiving a lot of focus in media. The specific origin discussed in this thesis lies within the suggestion of introducing an EU origin marking or what also can be referred to as “Made in EU” labelling. During the investigation of whether this creates a negative or positive attitude many factors are needed to be considered. The nationalistic feelings that still exist within the member states is one of the major obstacles but also information and consumer awareness concerning what EU stand for. The focus is on Swedish consumers’ perspective and the effects of implementing “Made in EU” are considered solely on the Swedish market. The theoretical framework is constructed around the central concept of country of origin (COO) that can be noted as of key relevance when investigating consumer behaviour. An analysis model is also introduced to give a deeper understanding of the connections between findings and the theoretical concepts. The fundamental methodology that was cho-sen in order to investigate these attitudes was found to be through the use of focus groups. These were carried out in combination with a secondary data analysis for the clarification of knowledge concerning the topic. What results shown from this study and the connected conclusions can be summarised in a few lines. First, Swedish consumers had generally a negative attitude towards introducing this label. The reason was that the consumers on one hand could not associate the origin as EU at the same time as Swedish consumers prefer to buy Swedish meat which is related to the Swedish model. Secondly, the factors brought forward that were influencing the COO shows what the attitude consist of, for instance stereotypes and perception. Thirdly, this research has managed to bring together new findings, previous COO studies with theoretical concepts and thereby created knowledge about Swedish ethnocentrism and cultural and economical aspects the Swedish consumers use when evaluating meat. Finally, the research method and theoretical concepts can be applied to other areas such as different products or countries.
15

EU Origin Marking : - A Study of Swedish Meat Consumers

Klint, Olle, Löfström, Patrik January 2005 (has links)
<p>The incentive to investigate the origin of meat products and their related consumer atti-tudes have shown to be a serious and debated topic especially after receiving a lot of focus in media. The specific origin discussed in this thesis lies within the suggestion of introducing an EU origin marking or what also can be referred to as “Made in EU” labelling. During the investigation of whether this creates a negative or positive attitude many factors are needed to be considered. The nationalistic feelings that still exist within the member states is one of the major obstacles but also information and consumer awareness concerning what EU stand for. The focus is on Swedish consumers’ perspective and the effects of implementing “Made in EU” are considered solely on the Swedish market.</p><p>The theoretical framework is constructed around the central concept of country of origin (COO) that can be noted as of key relevance when investigating consumer behaviour. An analysis model is also introduced to give a deeper understanding of the connections between findings and the theoretical concepts. The fundamental methodology that was cho-sen in order to investigate these attitudes was found to be through the use of focus groups. These were carried out in combination with a secondary data analysis for the clarification of knowledge concerning the topic.</p><p>What results shown from this study and the connected conclusions can be summarised in a few lines. First, Swedish consumers had generally a negative attitude towards introducing this label. The reason was that the consumers on one hand could not associate the origin as EU at the same time as Swedish consumers prefer to buy Swedish meat which is related to the Swedish model. Secondly, the factors brought forward that were influencing the COO shows what the attitude consist of, for instance stereotypes and perception. Thirdly, this research has managed to bring together new findings, previous COO studies with theoretical concepts and thereby created knowledge about Swedish ethnocentrism and cultural and economical aspects the Swedish consumers use when evaluating meat. Finally, the research method and theoretical concepts can be applied to other areas such as different products or countries.</p>
16

The provenance variation in natural durability of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco)

Akhter, Shaheen January 2001 (has links)
No description available.
17

"An indolent and chilly folk" : the development of the idea of the "Moriori myth"

Clayworth, Peter, n/a January 2001 (has links)
Throughout the nineteenth century probably the majority of Pakeha held the view that the East Polynesian ancestors of the Maori were the first people to settle in New Zealand. Over the same period there were always considerable numbers of Pakeha who held the alternative view that an earlier people were already living in New Zealand when the first East Polynesian immigrants arrived. Among Maori each hapu and iwi had their own origin traditions. Some held that their ancestors arrived to an empty land, while others believed there were other groups already here when their own ancestors arrived. The traditions of the Chatham Island Moriori indicated that they were also East Polynesian migrants, but some Pakeha speculated that the Moriori were a distinct people from the Maori. By the early twentieth century one set of ideas on early settlement had become the orthodox view of the past among Pakeha. This view, which held sway from the 1910s until at least the 1960s, maintained that the original people of New Zealand were the �Moriori�, a people only distantly related, if at all, to the Maori. This primitive early people were supposed to have been displaced by the arrival of the more advanced East Polynesian Maori. Some of the more fortunate Moriori were absorbed into the Maori tribes, while the majority were either killed or driven into exile on the Chatham Islands. This idea of the past, sometimes called the �Moriori Myth�, has now been largely rejected by scholars, but still holds some currency in popular circles. The current thesis examines the question of how the �Moriori Myth� developed and eventually became the orthodox view of the past. This question is investigated in the contexts of British imperial expansion, of the development of scientific ideas on race and evolution, and of the study of language and folklore as a way to decipher racial history. The current thesis is largely based on the writings of Pakeha and Maori scholars of the nineteenth and early twentieth centuries. Letters and manuscripts, in both English and Maori, have been used, along with published books and papers. The major focus of the work is the idea that the Moriori Myth largely developed out of the Pakeha study of Maori oral history. This study of oral history led to a considerable degree of interaction between Pakeha scholars and Maori experts. A major focus in the early part of the work is on Pakeha attempts to determine the racial identity and history of the Chatham Island Moriori. In this part of the work considerable attention has been paid to the collaborative work of the Pakeha scholar Alexander Shand and the Moriori expert Hirawanu Tapu, who worked together to record the surviving Moriori traditions. The focus of the latter part of this thesis is on the creation by Pakeha scholars of theoretical models of the early migrations to New Zealand, based on their understandings of Maori oral traditions. It will be argued that the �Moriori Myth� was largely based on the writings of Stephenson Percy Smith, as promoted by himself and Elsdon Best, through the medium of the knowledge network formed by the Polynesian Society. Smith�s writings on the �Moriori Myth� will be shown to have been largely based on his interpretations of the writings of the Ngati Kahungunu scholar Hoani Turei Whatahoro. It will be argued that the �Moriori Myth� was in fact the creation of interactions between Pakeha scholars and Maori experts rather than the invention of any one person or group.
18

Molecular events surrounding secretory granule biogenesis in transgenic hormone producing liver cell lines.

Lutherborrow, Mark Aaron, School of Medicine, UNSW January 2007 (has links)
Secretory granule biogenesis describes the events leading up to the budding of a nascent granule from the trans Golgi network. Literature surrounding secretory granule biogenesis is conflicting and has generated much debate. This thesis aims to address the important issues of this debate by utilizing the insulin-producing liver cell line HUH7-ins. This cell line has been shown to synthesize, store and secrete mature insulin in response to glucose via the possession of secretory granules. Using microarray technology the gene expression profile of HUH7-ins cells was compared with parental HUH7 cells, hoping to identify possible candidate genes contributing to secretory granule biogenesis. 164 genes were shown to be differentially expressed although no known granulogenic protein exhibited a change in expression. The data did suggest a nervous system differentiation event and implicates myosin Vc in the regulated secretion of insulin. HUH7-ins cells express a number of granulogenic protein mRNAs and while chromogranin B (CgB) protein level remained constant upon insulin expression, a significant increase in the level of chromogranin A (CgA) was observed, though the significance of this increase in expression is unknown. The over-expression of CgA in a clone of HUH7-ins that did not possess the regulated secretory pathway was unable to rescue the regulated secretory pathway, suggesting that CgA expression alone is unable to form secretory granules in our model. To determine if the secretory granule biogenesis seen in HUH7-ins cells was specific to insulin, three prohormones of different neuroendocrine origin were over-expressed in HUH7 cells; amylin ( cell), pancreatic polypeptide (pancreatic islet) and proopiomelanocortin (pituitary). None of these prohormones were able to form structures in the cytoplasm that resembled secretory granules by immunofluorescent microscopy, nor did they induce the expression of CgA. No prohormone was detected in cell lysates or conditioned media, raising the possibility that these exogenous prohormone aggregates are trafficked to the lysosomal/endosomal system for degradation. This study provides significant information regarding the genome-wide expression changes induced upon secretory granule biogenesis in a liver cell line, describes the lack of effect of CgA in this event and suggests that secretory granule biogenesis in this liver cell line is specific to insulin.
19

The Non-Ending Search for a Pre-DNA Replicator: Richard Dawkins and the Problem of Abiogenesis

Fryar, Randall Scott 16 May 2014 (has links)
This dissertation provides a rebuttal to the claims of Richard Dawkins in explaining the origin of life. The bulk of the ensuing analysis challenges his philosophical assumptions as it notes his vacillation between several models over time. The study further details Dawkins's multifaceted approach to the problem as it points out a number of errors permeating his general methodology and reasoning.
20

The biradical origin of semitic roots

Hecker, Bernice Varjick 28 August 2008 (has links)
Not available / text

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