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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.
71

Acoustic communication in Australian fur seals

Tripovich, Joy Sophie January 2007 (has links)
Doctor of Philosophy(PhD) / Communication is a fundamental process that allows animals to effectively transfer information between groups or individuals. Recognition plays an essential role in permitting animals to distinguish individuals based upon both communicatory and non-communicatory signals allowing animals to direct suitable behaviours towards them. Several modes of recognition exist and in colonial breeding animals which congregate in large numbers, acoustic signalling is thought to be the most effective as it suffers less from environmental degradation. Otariid seals (fur seals and sea lions) are generally colonial breeding species which congregate at high densities on offshore islands. In contrast to the other Arctocephaline species, the Australian fur seal, Arctocephalus pusillus doriferus, along with its conspecific, the Cape fur seal, A. p. pusillus, display many of the behavioural traits of sea lions. This may have important consequences in terms of its social structure and evolution. The acoustic communication of Australian fur seals was studied on Kanowna Island, Bass Strait, Australia. Analysing the acoustic structure of vocalisations and their use facilitates our understanding of the social function of calls in animal communication. The vocal repertoires of males, females, pups and yearlings were characterised and their behavioural context examined. Call structural variations in males were evident with changes in behavioural context, indicating parallel changes in the emotive state of sender. For a call to be used in vocal recognition it must display stereotypy within callers and variation between them. In Australian fur seal females and pups, individuals were found to have unique calls. Mutual mother-pup recognition has been suggested for otariids and this study supports the potential for this process to occur through the use of vocalisations. Call structural changes in pup vocalisations were also investigated over the progression of the year, from birth to weaning. Vocalisations produced by pups increased in duration, lowered in both the number of parts per call and the harmonic band containing the maximum frequency as they became older, suggesting calls are changing constantly as pups grow toward maturity. It has been suggested through descriptive reports, that the bark call produced by males is important to vocal recognition. The present study quantified this through the analysis of vocalisations produced by male Australian fur seals. Results support descriptive evidence suggesting that male barks can be used to discriminate callers. Traditional playback studies further confirmed that territorial male Australian fur seals respond significantly more to the calls of strangers than to those of neighbours, supporting male vocal recognition. This study modified call features of the bark to determine the importance to vocal recognition. The results indicate that the whole frequency spectrum was important to recognition. There was also an increase in response from males when they heard more bark units, indicating the importance of repetition by a caller. Recognition occurred when males heard between 25-75% of each bark unit, indicating that the whole duration of each bark unit is not necessary for recognition to occur. This may have particular advantages for communication in acoustically complex breeding environments, where parts of calls may be degraded by the environment. The present study examined the life history characteristics of otariids to determine the factors likely to influence and shape its vocal behaviour. Preliminary results indicate that female density, body size and the breeding environment all influence the vocal behaviour of otariids, while duration of lactation and the degree of polygyny do not appear to be influential. Understanding these interactions may help elucidate how vocal recognition and communication have evolved in different pinniped species.
72

Paternalism and identity : the role of personal labour organization in the formation of group identity among the Metis in the Rupertsland fur trade and the Aboriginal people in the northern Australian cattle industry

Parker, Leanna 02 January 2007
The question of the origins of a Metis identity in Canada is one that has been contemplated by several scholars. These scholars have taken various approaches to the question, many focusing solely on the social and political aspects of Metis history. While such approaches can be useful, they ignore the crucial influence of the economic and labour relations of the Rupertsland fur trade in the development and expression of a distinct Metis identity in western Canada. The unique economic and labour relations of the Rupertsland fur trade, identified by H. Clare Pentland as personal labour relationships, allowed a cohesiveness and inter-connectedness to develop between the Aboriginal labourers and their European employers which emphasized the interdependencies inherent in the industry. However, while personal labour relations were an important catalyst for the development and expression of a distinct Metis identity, it is too simplistic to suggest that it was these relations alone that encouraged such a phenomenon. The northern Australian cattle industry utilized similar economic and labour relations and yet a distinct mixed descent identity did not develop in Australia. Therefore, the external influences in the industry must also be examined. The four most important external influences that encouraged the development of a Metis identity in Canada and discouraged a similar event in Australia were: the needs of the colonial employers in regards to land tenure; the economic opportunities available to the people of mixed descent; the educational opportunities available to the people of mixed descent; and, the time depth of contact in both industries. These four external influences combined with the use of personal labour organization in the Rupertsland fur trade encouraged the development and expression of a distinct Metis identity in Canada.
73

Tracking Down South Branch House: A Critical Look at the Identification of the Hudsons Bay Companys South Branch House (FfNm-1)

Markowski, Michael A. 04 August 2009
The late Arthur Silver Morton has contributed immensely to our understanding and preservation of western Canadian history. One of Mortons joys was locating remains of long forgotten fur trade posts. As a result, a large number of the Saskatchewan fur trade posts that we know of were located and recorded by Morton. The majority of Mortons investigations took place throughout the 1930s and 1940s. Morton consulted whatever historic sources were available to him at the time: numerous historic documents, ethnographic accounts and local histories.<p> There has been archaeological evidence that suggests Morton misidentified numerous fur trade post sites. For example, research at the Hudsons Bay Companys South Branch House (1786-1794), which Morton identified in 1944, has sparked some controversy as to whether or not it is that particular post. As a result, this provides the author with an excellent chance to examine how Morton identified Saskatchewan fur trade posts and to determine through archaeological excavations and historical documents the accuracy of Mortons historical site designation at South Branch House.<p> A critical approach to Mortons work will determine how accurate his work is for contemporary archaeological investigations of fur trade posts. Furthermore, this thesis may provide historical archaeologists with insights as to how to go about identifying fur trade posts, which will contribute to our overall understanding of the western Canadian fur trade.
74

Importancia de los genes fur y thyA en la patogenia de Haemophilus parasuis

Bigas Terricabras, Anna 14 December 2007 (has links)
Haemophilus parasuis es un miembro de la familia Pasteurellaceae y un importante patógeno del tracto respiratorio porcino, causante de la enfermedad de Glässer. En la actualidad, esta enfermedad es una de las que tiene mayor incidencia en el sector porcino con una elevada repercusión económica. Por este motivo, es necesario estudiar la biología molecular de este patógeno para poder desarrollar vacunas más eficientes que las existentes hasta el presente. Para abordar dicho estudio es imprescindible disponer de algún proceso de transferencia genética eficaz en H. parasuis. No obstante, dado el desconocimiento que se tenía de dicho patógeno, no se conocía ningún mecanismo natural o de laboratorio que permitiera introducir DNA en H. parasuis. Por ello, el primer objetivo del presente trabajo ha sido desarrollar un método de transferencia genética en H. parasuis que permita estudiar posteriormente los genes implicados en su virulencia y en la colonización del hospedador.En la presente tesis se ha demostrado por vez primera que H. parasuis es capaz de transformar de forma natural si el DNA exógeno contiene la secuencia ACCGAACTC, la cual es muy similar al motivo ACCGCACTT descrito en H. influenzae como Uptake Signal Sequence. Además, se ha optimizado este proceso, determinando las concentraciones más adecuadas de células bacterianas, AMPc y DNA transformante, así como el tiempo de incubación. Un segundo objetivo de este trabajo ha sido averiguar el papel de la timidilato sintasa, enzima clave en la síntesis de desoxitimidina monofosfato (dTMP), en la virulencia de H. parasuis. Para ello, se ha construido un mutante knockout en el gen thyA de H. parasuis y se ha determinado la capacidad de colonización y la inmunogeniciad de la cepa salvaje y de dicho mutante thyA en un modelo animal de cobayas. Los resultados han mostrado que la cepa defectiva en la enzima timidilato sintasa tienen una menor capacidad de colonización, a pesar de que es capaz de inducir una respuesta inmune en el animal. Por ello, el mutante thyA de H. parasuis puede ser un buen candidato para el desarrollo de futuras vacunas.Finalmente, en este trabajo se ha estudiado la importancia de la proteína Fur en la virulencia de H. parasuis. Dicha proteína es un regulador pleiotrópico que, entre otras funciones, controla los mecanismos implicados en la captación de hierro. Para abordar esta parte del trabajo se propuso la construcción de un mutante de H. parasuis defectivo en la proteína Fur. Los resultados obtenidos han mostrado claramente que dicha proteína es esencial para la viabilidad de esta bacteria. Así, se ha determinado el entorno genético del gen fur y se ha confirmado la no viabilidad de los mutantes fur mediante la obtención de cepas merodiploides. / Haemophilus parasuis, is a member of the family Pasteurellaceae and an important respiratory-tract pathogen of swine, which is the etiological agent of Glässer's disease. At present, the H. parasuis infections produce significant mortality and morbidity in pig farms, giving rise to important economic losses in this industry. For this reason, it is necessary to study the molecular biology of this pathogen to develop vaccines more efficient. Because no genetic manipulation system is available for H. parasuis so far, the first objective of this work was to develop a method of gene transfer to study the genes involved in virulence of this organism. In this work has been demonstrated for the first time that H. parasuis is capable of transforming exogenous DNA which contains ACCGAACTC sequence. This sequence is very similar to the motive ACCGCACTT described in H. influenzae as Uptake Signal Sequence. In addition, this process has been optimized, determining the most appropriate concentrations of bacterial cells, cAMP and transforming DNA, as well as the incubation time.A second objective of this study was to determine the role of thymidylate synthase enzyme in the virulence of H. parasuis. This enzyme is essential for dTMP synthesis and, consequently, for DNA replication. To do so, a H. parasuis thyA mutant was constructed in order to analyze its colonization characteristics and its capacity to generate serum bactericidal activity in infected guinea pigs. The data showed that colonization by the H. parasuis thyA mutant was much less than that of the wild-type strain. Nevertheless, the mutant generated a strong immunogenic response similar to the wild-type strain. Therefore, the H. parasuis thyA mutant can be a good candidate to develop future vaccines. Finally, this work has studied the importance of the Fur protein in the virulence of H. parasuis. This protein is a global regulator which, among other duties, controls the mechanisms involved in iron uptake. To perform this part of the study was proposed the construction of a H. parasuis fur mutant. The results have clearly shown that this protein is essential for the viability of this bacterium. Thus, it has been determined the genetic surrounding of fur gene and has confirmed the non-viability of fur mutants by obtaining H. parasuis fur-defective merodiploid strains.
75

Paternalism and identity : the role of personal labour organization in the formation of group identity among the Metis in the Rupertsland fur trade and the Aboriginal people in the northern Australian cattle industry

Parker, Leanna 02 January 2007 (has links)
The question of the origins of a Metis identity in Canada is one that has been contemplated by several scholars. These scholars have taken various approaches to the question, many focusing solely on the social and political aspects of Metis history. While such approaches can be useful, they ignore the crucial influence of the economic and labour relations of the Rupertsland fur trade in the development and expression of a distinct Metis identity in western Canada. The unique economic and labour relations of the Rupertsland fur trade, identified by H. Clare Pentland as personal labour relationships, allowed a cohesiveness and inter-connectedness to develop between the Aboriginal labourers and their European employers which emphasized the interdependencies inherent in the industry. However, while personal labour relations were an important catalyst for the development and expression of a distinct Metis identity, it is too simplistic to suggest that it was these relations alone that encouraged such a phenomenon. The northern Australian cattle industry utilized similar economic and labour relations and yet a distinct mixed descent identity did not develop in Australia. Therefore, the external influences in the industry must also be examined. The four most important external influences that encouraged the development of a Metis identity in Canada and discouraged a similar event in Australia were: the needs of the colonial employers in regards to land tenure; the economic opportunities available to the people of mixed descent; the educational opportunities available to the people of mixed descent; and, the time depth of contact in both industries. These four external influences combined with the use of personal labour organization in the Rupertsland fur trade encouraged the development and expression of a distinct Metis identity in Canada.
76

Tracking Down South Branch House: A Critical Look at the Identification of the Hudsons Bay Companys South Branch House (FfNm-1)

Markowski, Michael A. 04 August 2009 (has links)
The late Arthur Silver Morton has contributed immensely to our understanding and preservation of western Canadian history. One of Mortons joys was locating remains of long forgotten fur trade posts. As a result, a large number of the Saskatchewan fur trade posts that we know of were located and recorded by Morton. The majority of Mortons investigations took place throughout the 1930s and 1940s. Morton consulted whatever historic sources were available to him at the time: numerous historic documents, ethnographic accounts and local histories.<p> There has been archaeological evidence that suggests Morton misidentified numerous fur trade post sites. For example, research at the Hudsons Bay Companys South Branch House (1786-1794), which Morton identified in 1944, has sparked some controversy as to whether or not it is that particular post. As a result, this provides the author with an excellent chance to examine how Morton identified Saskatchewan fur trade posts and to determine through archaeological excavations and historical documents the accuracy of Mortons historical site designation at South Branch House.<p> A critical approach to Mortons work will determine how accurate his work is for contemporary archaeological investigations of fur trade posts. Furthermore, this thesis may provide historical archaeologists with insights as to how to go about identifying fur trade posts, which will contribute to our overall understanding of the western Canadian fur trade.
77

His Majesty's hired transport schooner Nancy

Sabick, Christopher Robert 29 August 2005 (has links)
In 1997 a group of archaeologists from Texas A&M University's Nautical Archaeology Program traveled to Wasaga Beach, Ontario to document the hull remains of the eighteenth-century schooner Nancy. In 1927, the schooner was recovered from the banks of an island in the Nottawasaga River, near its confluence with Lake Huron. The hull is now on display in the Nancy Island Historic Site. Despite being available to the public for more than 75 years, the 1997 documentation was the first to thoroughly record the construction of the vessel. In addition to archaeological investigation, historical research was carried out to further our understanding of Nancy's commercial and naval career. The archaeological data reveal a schooner that was built by talented shipwrights using the fine timber harvested around the Great Lakes in the eighteenth-century. This study adds a considerable amount of new information to the otherwise scanty base of knowledge available on the construction of early Great Lakes sailing vessels. Historical research shows that Nancy and her crews were participants in many important events that shaped the Great Lakes Region. From her construction in Detroit in 1789, Nancy was employed in the fur trade. As tensions flared between Great Britain and the United States in 1812, Nancy was utilized as an armed transport for the British forces around the lakes. in August of 1814, the schooner was trapped in the Nottawasaga River by a strong American naval force. Nancy's commander set fire to the vessel to deny it to the enemy. This thesis examines the construction details and history of the schooner Nancy in detail. Preliminary chapters will provide the historical context for the vessel and describe Nancy's long journey that ended at the Nancy Island Historic Site. The second half of the thesis describes the construction of the schooner and compares it with other contemporary vessels. The study concludes that Nancy's hull represents an eighteeth-century construction tradition modified for use on the Great Lakes, and also demonstrates the vessel's dual roles as trader and military transport.
78

Molecular ecology of North Pacific Otariids : genetic assessment of north fur seal and Steller sea lion distributions /

Ream, Rolf R. January 2002 (has links)
Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 97-117).
79

Historical population genetics of Callorhinus ursinus (Northern fur seals) from the Aleutian Islands

Fang, Ying January 2009 (has links) (PDF)
Thesis (M.S.)--University of North Carolina Wilmington, 2009. / Title from PDF title page (February 16, 2010) Includes bibliographical references (p. 82-86)
80

The effects of tourism on the behaviour of the New Zealand fur seal (Arctocephalus forsteri)

Cate, Jenipher Rose January 2013 (has links)
The demand by ecotourism for easily accessible wildlife encounters has increased the need for regulations to minimise negative effects of tourism on towards marine mammals. High levels of human interaction could have serious consequences for recovering populations of New Zealand fur seals (Arctocephalus forsteri). By monitoring behavioural shifts in reactions to human disturbance, the aim of this study was to determine how disturbance by tourism is affecting the behaviour of the New Zealand fur seals. Fur seal breeding colonies, haul-outs, and a pup nursery were studied on the South Island to determine the level of disturbance. Data collected in this study can be used towards improving monitoring regimes to mitigate negative effects of anthropogenic disturbance. I first used behavioural observations to assess a seal’s behaviour in response to different types of tourist activities. Next, I examined changes in New Zealand fur seal behaviour as a result of visits to colonies by tourist boats. To quantify the response of fur seals to tourist boats, experimental boat approaches were conducted using a before, during, and after instantaneous scan sampling method at two breeding colonies (one with high vessel traffic and one with none). Impact of noise was also investigated using a loud speaker to mimic local harbour tours. Lastly, behavioural observations on seal pups at a nursery were conducted comparing pup behaviour in the presence and absence of tourism along with variable intensities of tourist behaviour. My observations suggest that seal behaviour was significantly different between sites with and without tourist visits. The type of tourism had a significant effect on the behavioural state of seals, with animals more active when there were people walking in the colonies. There were also signs of habituation in some of the study colonies. Since each colony varied in the type of tourism it experienced, it is possible that it is not only the level of tourism that is important but also the type of tourism that has a significant role in eliciting short-term behavioural shifts. Observations from a tour boat revealed an increase in the percentage of seals reacting when vessels were close to the shore. This distance effect was overridden and reactions were greater, however, when tours included commentary via an external speaker. The effects of both distance and noises were significantly different between colonies with high and low levels of tourist visits. Due to the overlap of peak tourist visits with fur seal breeding season, these animals are at their most vulnerable when companies are in peak operation. Finally, as with adults, pup behaviour was also significantly affected by tourism presence. Periods of inactivity and awareness increased in the presence of tourists, which is indicative of disruption of “play” and movement towards more vigilant behaviour. Despite the significant effects of tourist visits I found in this study, there was large variation in the degree of responses in different populations of the fur seal. This variation is thought to be due, in part, by the level of desensitisation, especially at locations with high or continual tourism pressures. This study also provides evidence that fur seal pups subject to human disturbance will alter their behaviour, shifting from active (when people are not around) to inactive and more aware (with increased disturbance). The results presented suggest such visits are not without consequences and that animals can be disturbed by human interactions. Therefore, measures should be taken at all seal colonies used in tourism ventures to mitigate any negative long-term effect on the fur seal populations.

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