• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 7
  • 2
  • 2
  • Tagged with
  • 21
  • 21
  • 5
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 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

Assessing and monitoring genetic patterns for conservation purposes with special emphasis on Scandinavia

Palmé, Anna January 2010 (has links)
Genetic variation is essential for biological evolution, for maintaining viability of populations, and to ensure ecosystem resilience. Increased human exploitation and environmental change result in rapid loss of biological variation, including genetic diversity. Measures to halt this trend require that biological diversity is assessed and monitored. Assessment of biodiversity includes identifying patterns of distribution of genetic variation within individual species. This thesis focuses on spatial genetic structure and assessment of units for conservation in continuous environments without apparent migration barriers. Empirical data refer to Scandinavia and the model species are northern pike (Esox lucius), brown trout (Salmo trutta), and harbour porpoise (Phocoena phocoena). Questions regarding monitoring genetic diversity and releases of alien populations are also addressed.  The spatial genetic structure of the northern pike in the Baltic Sea is characterized by isolation by distance and continuous genetic change. Positive genetic correlation was found among pike within geographical distances of less than 150 km. This distance may be used to suggest management units in this area. For the brown trout, genetic monitoring identified two sympatric populations within a small mountain lake system. The situation is characterized by a clear genetic but no apparent phenotypic dichotomy. Scientific support for a genetically distinct Baltic harbour porpoise population is limited, and the spatial genetic structure of the harbour porpoise in Swedish waters needs to be clarified. Data for launching conservation genetic monitoring programs is available for only a few Swedish species. Millions of forest trees, fish, and birds are released annually in Sweden and the documentation on these releases is poor. To meet responsibilities of safeguarding biodiversity and surveying biological effects of releases, there is an urgent need for studies aimed at evaluating genetic diversity. / At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.
12

The role of policy management units with particular reference to the PMU in the South African Parliament

Qwaka, Prince Siphiwo January 2011 (has links)
<p>This study seeks to understand and examine the role of public policy units with a specific focus on the South African National Parliament Policy Management Unit (PMU). The problem being investigated is that of a lack of constructive support and debate in understanding the role and functions of policy management units. Thus, the scope of the study is limited to policy management units with the South African Parliament PMU as a special reference. The primary objective of this study is to investigate the role of policy management units, with particular reference to the PMU in the South African Parliament. The secondary objectives will then be to provide a theoretical perspective of the role and functions of policy management units / and to develop a case of the PMU in Parliament for further analysis and examination. Examples of existing policy units and the support they have with parliaments will be produced, assessed, and explored.</p>
13

Qualidade e ecotoxicidade da água da Bacia Hidrográfica do rio São José dos Dourados-SP /

Ribeiro, Lucíola Guimarães January 2018 (has links)
Orientador: Juliana Heloisa Pinê Américo-Pinheiro / Resumo: O monitoramento qualitativo e quantitativo das águas superficiais pode indicar as atividades humanas, que apresentam potenciais riscos a este recurso, servindo assim como uma ferramenta fundamental para a gestão dos corpos d’água. A realização de estudos relacionados aos recursos hídricos fornece informações capazes de estabelecer os critérios para sua gestão e tomadas de decisão considerando o enquadramento dos corpos d'água e as particularidades de cada bacia hidrográfica. Nesse contexto, este estudo abordou os fatores que interferem negativamente na qualidade da água e os danos causados aos recursos hídricos e a biota aquática como consequência desses fatores. O objetivo desta pesquisa foi avaliar a qualidade e a ecotoxicidade da água da Bacia Hidrográfica do Rio São José dos Dourados-SP.Foram utilizados seis pontos de monitoramento devidamente georreferenciados da Rede Básica Integrada da CETESB/ANA que existe na UGRHI 18. Os parâmetros de qualidade de água avaliados na bacia hidrográfica foram: sólidos totais, temperatura, turbidez, demanda bioquímica de oxigênio (DBO), fósforo total,nitrogênio total, oxigênio dissolvido, pH, Escherichia coli e ensaio ecotoxicológico com Ceriodaphnia dubia. Os parâmetros físicos, químicos, microbiológico e ecotoxicológico foram avaliados separadamente e posteriormente o índice de qualidade da água (IQA) foi determinado a fim de se verificar qual a melhor forma de avaliação da qualidade dos recursos hídricos. Os dados referentes aos parâm... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Qualitative and quantitative monitoring of superficial waters can indicate human activities which present risks to this resource, serving as a main instrument to the management of water bodies. Studies related to hydric resources provide information that can establish criteria for their management and decision-making, considering the framing of the water bodies and the particularities of each watershed. In this context, this study approached the factors that interfere in a negative way in water quality and the damages caused to hydric resources, and the aquatic biota as an effect of those factors. This resource aimed at evaluating the quality and the ecotoxicity of water from the Watershed of the River São José dos Dourados-SP. We used six points of monitoring properly georeferenced from the Integrated Basic Web of CETESB/ANA that exists in UGRHI 18. The parameters of water quality that were evaluated in the watershed are: total solids, temperature, turbidity, biochemical oxygen demand (BOD), total phosphorus, total nitrogen, dissolved oxygen, pH, Escherichia coli and ecotoxicological experiment with Ceriodaphnia dubia. Physical, chemical, microbiological and ecotoxicological parameters were evaluated separately and later the index of water quality (IWQ) was determined to verify the best way to evaluate the quality of hydric resources. The data about water quality parameters were obtained from the Report of Quality of Superficial Waters in the State of São Paulo of the year 2... (Complete abstract click electronic access below) / Mestre
14

The role of policy management units with particular reference to the PMU in the South African Parliament

Qwaka, Prince Siphiwo January 2011 (has links)
Magister Administrationis - MAdmin / This study seeks to understand and examine the role of public policy units with a specific focus on the South African National Parliament Policy Management Unit (PMU). The problem being investigated is that of a lack of constructive support and debate in understanding the role and functions of policy management units. Thus, the scope of the study is limited to policy management units with the South African Parliament PMU as a special reference. The primary objective of this study is to investigate the role of policy management units, with particular reference to the PMU in the South African Parliament. The secondary objectives will then be to provide a theoretical perspective of the role and functions of policy management units; and to develop a case of the PMU in Parliament for further analysis and examination. Examples of existing policy units and the support they have with parliaments will be produced, assessed, and explored. / South Africa
15

Augmenting uClinux and RTAI with Memory Access Control for the BlackFin DSP

Ulbricht, Michael 03 June 2007 (has links)
In Verbindung mit eingebetteten Systemen spielte Sicherheit in der Vergangenheit eher eine untergeordnete Rolle. Im Vordergrund standen vorhersagbare Ausführungszeiten und der finanzielle Rahmen. Aufgrund der zunehmenden Vernetzung und der Konzentration mehrerer Anwendungen auf einen Prozessor gewinnt dieser Gesichtspunkt jedoch stärker an Bedeutung. Der Blackfin-Prozessor des Herstellers Analog Devices, welcher die Konzepte von Mikrocontroller und digitalem Signalprozessor in sich vereint, entspricht diesem Trend, indem er die Möglichkeit des Speicherschutzes integriert. Das Betriebssystem uClinux wurde speziell auf die Bedürfnisse von eingebetteten Systemen angepasst, da es im Gegensatz zu Linux keinen virtuellen Speicher unterstützt. Es wurde zwar bereits auf die Architektur des Blackfin Prozessors portiert, verfügte jedoch bisher nicht über nennenswerte Mechanismen zum Schutz des Speichers. Der Hauptteil dieser Diplomarbeit besteht deshalb darin, Linux’ Speicherverwaltung zu analysieren, einen ähnlichen Ansatz in uClinux zu implementieren und schließlich den Einfluss auf die Leistung des Systems zu ermitteln. Die entstandene Realisierung schützt sowohl den Speicher einzelner Prozesse als auch den des Betriebssystemkerns. Obwohl die Lösung im Moment noch prototypischen Charakter besitzt, ist sie bereits voll funktionsfähig. Des Weiteren diskutiert die Arbeit auch den Ansatz des alleinigen Kernel-Schutzes und unterbreitet einen Vorschlag zur Verringerung der Interrupt-Latenzzeit. / In the past, embedded system’s security has been often omitted in order to trade it for system cost and more predictable execution timings. Due to the pressure induced by increased networking and multitasking, this issue is getting more important. Therefore, Analog Devices’ Blackfin processor, which combines capabilities of signal processing and controlling, additionally provides means for memory protection. The operating system uClinux, which is especially suitable for embedded systems because support for Virtual Memory has been removed, has already been ported to the Blackfin architecture, but still lacks support for memory protection. Thus, the main effort of this thesis consists of analysing Linux’s memory management, reimplementing similar approaches into the uClinux kernel, and measuring the resulting overhead. The implemented protection scheme does secure both particular processes and kernel space. Even if it is still in a prototypical state, memory protection is fully functional. In addition, approaches for exclusive kernel protection and reducing interrupt latency are discussed.
16

Comunicación interna y su incidencia en la satisfacción laboral en una Unidad de Gestión Educativa Local de Lima Metropolitana / Internal corporate communication and its impact on job satisfaction in a Local Educational Management Unit in Metropolitan Lima

Mejía Delgado, Edith Yovani, García Molero, Melissa Jovita, Colchado Vergaray, Mary Patricia 23 November 2020 (has links)
Este estudio trata acerca de la comunicación interna y su incidencia en la satisfacción laboral en una Unidad de Gestión Educativa Local de Lima Metropolitana. Dentro de los objetivos se planteó determinar la relación entre la comunicación interna y la satisfacción laboral en los colaboradores de una Unidad de Gestión Educativa Local de Lima Metropolitana. Para ello, se diseñó una investigación de tipo descriptiva correlacional, en donde se aplicó una encuesta por cuestionario de 54 ítems a 143 colaboradores de una Unidad de Gestión Educativa Local de Lima Metropolitana para medir las variables de investigación. El instrumento se elaboró con la escala de Likert, con puntajes del 1 al 5, se ha determinado según el Coeficiente de Pearson (R=0,675) y T student, que existe una relación entre las variables de estudio; el nivel de percepción de la comunicación interna se encontró predominantemente un nivel alto en 62%, para la variable Satisfacción laboral se encontró predominantemente un nivel alto en 54%. / This study is about the internal corporate communication and its incidence on job satisfaction in a Local Educational Management Unit in Metropolitan Lima. Within the objectives there are set goals to determine the relationship between internal corporate communication and job satisfaction in the collaborators in the Local Educational Management Unit in Metropolitan Lima. For this, there has been designed a descriptive correlational research, where a questionnaire survey of 54 items was applied to 143 collaborators of a Local Educational Management Unit in Metropolitan Lima to measure the research variables. The instrument was developed with the Likert scale, with scores from 1 to 5, it has been determined according to Pearson's Coefficient (r = 0.675) and Student's T, that there is a relationship between the study variables; The level of perception of internal corporate communication was found to be a predominantly high level of 62%, for the variable Job satisfaction a predominantly high level was found of 54%. / Tesis
17

Exploring Co-management : A Minor Field Study on Lake Victoria Beach Management Unit in Ggaba, Kampala, Uganda / Hantering av Victoriasjön som gemensam fiskeresurs : En MFS-studie om samförvaltningen vid Ggaba Beach Management Unit

Lundström, Linnéa, Nordlund, Sara January 2016 (has links)
To manage common resources such as water bodies, forests and the air is complex since several stakeholders are involved and affected by the use of the resource. One way to manage common resources is through co-management. Co-management is a decentralized method that empowers the local level and enables collaboration between the government and the local community. Co-management within fishing communities can be realized through so called Beach Management Units (BMUs). Around Lake Victoria, there are 1087 BMUs. One of these BMUs is located in Ggaba, Kampala, Uganda and the purpose of this study is to highlight benefits and shortcomings connected to co-management within fisheries. The study aims to explore if and how sustainability aspects are tackled through the co-management of fisheries. The data was collected using qualitative semi-structured interviews where six BMU members contributed with their experiences. In addition, data was collected from a qualitative content analysis on two BMU guideline documents, representing the central level. The results showed that the Ggaba BMU provides a platform for creating control through collaboration. The local levels’ perception on co-management within fisheries seems to correspond with the central level’s aim of the management. Another indication is that the BMU has brought upon positive effects on economic, social and ecological aspects on the society of Ggaba. However, corruption and illegal fishing are two identified barriers which seems to limit the function of the Ggaba BMU and the level of co-management. / Gemsamma resurser så som vattendrag, skogar och atmosfären är komplexa att hantera eftersom flera aktörer är involverade och påverkas av resursanvändningen. Ett sätt att hantera gemensamma resurser är genom samförvaltning. Samförvaltning är en decentraliserad förvaltningsmetod som möjliggör ett samarbete mellan den lokala och statliga nivån vid beslutsfattande. Omkring Victoriasjön realiseras samförvaltning genom så kallade Beach Management Units (BMUs). Dessa utgörs av 1087 stycken varav en BMU är lokaliserad i Ggaba, Kampala, Uganda. Syftet med denna studie är att belysa fördelar och brister kopplade till samförvaltning av fiske. Vidare syftar studien till att undersöka om och hur aspekter inom hållbar utveckling kan tacklas genom det decentraliserade styret av fiske. Data insamlades genom sex stycken kvalitativa, semistrukturerade intervjuer. Dessutom gjordes en kvalitativ innehållsanalys av två BMU-riktlinjedokument, vilka representerar den centrala nivån. Det empiriska materialet visade att Ggaba BMU utgör en plattform för strukturering, kontroll och samarbete. Den lokala nivåns syn på samförvaltning inom fiske verkar överensstämma med den centrala nivåns avsikt av samförvaltning. Resultatet indikerar även att BMUn har påverkat ekonomiska, sociala och ekologiska aspekter i Ggaba på ett positivt sätt. Problem med korruption och olagligt fiske identifierades dock, vilka verkar begränsa BMUns funktion och möjligheterna till samförvaltning.
18

Evolução de uma unidade de gerenciamento eletrônico de um motor VW 2.0L e desenvolvimento de controle de cruzeiro: Projeto Otto IV / Enhancement of an electronic management unit for a VW 2.0L engine and development of cruise control: Otto IV Project.

Bruno César Fernandes Pereira 25 August 2017 (has links)
Com o passar do tempo, nota-se um aumento gradativo da demanda por veículos mais econômicos e que disponham de itens capazes de aumentar o conforto e a segurança. Citase, como exemplo, o controle de cruzeiro (Cruise Control) que, atualmente presente em diversos veículos, é responsável por controlar a velocidade do veículo de maneira autônoma, sem a necessidade de intervenção do condutor no pedal de aceleração, resultando em um aumento de conforto ao reduzir o esforço para dirigir, além de prover efetividade para manter a velocidade do veículo em torno de um valor desejado. Neste contexto, o presente trabalho apresenta o desenvolvimento de um controlador de cruzeiro para operar em um veículo modelo Volkswagen Polo Sedan 2.0L 2004, o qual não possui este recurso em seu estado de fábrica. Para a implementação deste recurso, o trabalho faz uso de uma unidade de gerenciamento eletrônico (conhecida também por Electronic Control Unit - ECU) desenvolvida em 2013, no âmbito do projeto Otto II (PEREIRA, 2013), para controle do motor presente no respectivo veículo, viabilizando, desta forma, a validação do controle de cruzeiro por meio de testes utilizando o veículo em um dinamômetro inercial. Entretanto, previamente ao projeto do controlador de cruzeiro, o presente trabalho teve como foco o aperfeiçoamento do funcionamento desta ECU, visando a sua evolução no que diz respeito ao estado da arte de unidades de gerenciamento eletrônico de motores. Para isto, em sua primeira fase, o trabalho realizou diversas melhorias nas malhas de controle já existentes no firmware de 2013, tais como controle de marcha lenta, controle da borboleta eletrônica e controle de partida. Ao mesmo tempo, novos recursos foram implementados em firmware: controle de torque, controle da mistura ar/combustível em malha fechada (sonda lambda), segurança na comunicação entre blocos da ECU, identificação de marcha, suporte para diagnóstico via OBD-II, dentre outros. Além destas atividades envolvendo desenvolvimento de firmware, o trabalho, ainda em sua primeira fase, promoveu o desenvolvimento de uma nova ferramenta de software que, além de ser capaz de monitorar diversos parâmetros da ECU em tempo real, integra diversas funções, tais como função de computador de bordo alternativo, opção para controle do motor através da simulação do pedal de aceleração, opção para alteração da rotação de marcha lenta e função para automatização do ensaio de identificação do veículo (tarefa necessária para o projeto do controlador de cruzeiro). / Over time, there is a gradual increase of the demand for economical vehicles equipped with items capable of increasing the comfort and safety. As an example, the Cruise Control, which is already available in several vehicles, is responsible to control the vehicle speed in an autonomous manner, without the driver intervention on the throttle pedal. As a result, a greater comfort is achieved by reducing the effort to drive, besides providing effectiveness to keep the vehicle speed around a desired value. In this context, this project aims the development of a Cruise Control applied to a vehicle Volkswagen Polo Sedan 2.0L 2004, in which such resource is not available. To implement this resource, the project uses an electronic engine management unit (also known as Electronic Control Unit - ECU) developed in 2013 by the Otto II project (PEREIRA, 2013). This ECU is responsible to control the engine of the respective vehicle, which allows the Cruise Control validation through a set of tests performed with the vehicle on an inertial dynamometer. However, prior to the Cruise Control design, this project focused on the ECU operation enhancement, in order to achieve the state of the art in electronic engine management units. For this goal, the project, during its first phase, performed several improvements on the control algorithms already existing in the firmware developed in 2013, such as idle speed control, electronic throttle valve control and engine starting control. At the same time, new features were fully implemented in firmware: torque control, closed loop air/fuel ratio control (lambda control), safety for the communication among ECU blocks, gear identification, support to OBD-II diagnostic, among others. In addition to the firmware development activities, the project, still in its first phase, developed a new software tool capable of monitoring several ECU parameters in real time, besides providing many functions, such as alternative board computer, an option to control the engine by simulating the throttle pedal, an option to change the idle speed and a function to automate the system identification test (task required for the Cruise Control design).
19

Evolução de uma unidade de gerenciamento eletrônico de um motor VW 2.0L e desenvolvimento de controle de cruzeiro: Projeto Otto IV / Enhancement of an electronic management unit for a VW 2.0L engine and development of cruise control: Otto IV Project.

Pereira, Bruno César Fernandes 25 August 2017 (has links)
Com o passar do tempo, nota-se um aumento gradativo da demanda por veículos mais econômicos e que disponham de itens capazes de aumentar o conforto e a segurança. Citase, como exemplo, o controle de cruzeiro (Cruise Control) que, atualmente presente em diversos veículos, é responsável por controlar a velocidade do veículo de maneira autônoma, sem a necessidade de intervenção do condutor no pedal de aceleração, resultando em um aumento de conforto ao reduzir o esforço para dirigir, além de prover efetividade para manter a velocidade do veículo em torno de um valor desejado. Neste contexto, o presente trabalho apresenta o desenvolvimento de um controlador de cruzeiro para operar em um veículo modelo Volkswagen Polo Sedan 2.0L 2004, o qual não possui este recurso em seu estado de fábrica. Para a implementação deste recurso, o trabalho faz uso de uma unidade de gerenciamento eletrônico (conhecida também por Electronic Control Unit - ECU) desenvolvida em 2013, no âmbito do projeto Otto II (PEREIRA, 2013), para controle do motor presente no respectivo veículo, viabilizando, desta forma, a validação do controle de cruzeiro por meio de testes utilizando o veículo em um dinamômetro inercial. Entretanto, previamente ao projeto do controlador de cruzeiro, o presente trabalho teve como foco o aperfeiçoamento do funcionamento desta ECU, visando a sua evolução no que diz respeito ao estado da arte de unidades de gerenciamento eletrônico de motores. Para isto, em sua primeira fase, o trabalho realizou diversas melhorias nas malhas de controle já existentes no firmware de 2013, tais como controle de marcha lenta, controle da borboleta eletrônica e controle de partida. Ao mesmo tempo, novos recursos foram implementados em firmware: controle de torque, controle da mistura ar/combustível em malha fechada (sonda lambda), segurança na comunicação entre blocos da ECU, identificação de marcha, suporte para diagnóstico via OBD-II, dentre outros. Além destas atividades envolvendo desenvolvimento de firmware, o trabalho, ainda em sua primeira fase, promoveu o desenvolvimento de uma nova ferramenta de software que, além de ser capaz de monitorar diversos parâmetros da ECU em tempo real, integra diversas funções, tais como função de computador de bordo alternativo, opção para controle do motor através da simulação do pedal de aceleração, opção para alteração da rotação de marcha lenta e função para automatização do ensaio de identificação do veículo (tarefa necessária para o projeto do controlador de cruzeiro). / Over time, there is a gradual increase of the demand for economical vehicles equipped with items capable of increasing the comfort and safety. As an example, the Cruise Control, which is already available in several vehicles, is responsible to control the vehicle speed in an autonomous manner, without the driver intervention on the throttle pedal. As a result, a greater comfort is achieved by reducing the effort to drive, besides providing effectiveness to keep the vehicle speed around a desired value. In this context, this project aims the development of a Cruise Control applied to a vehicle Volkswagen Polo Sedan 2.0L 2004, in which such resource is not available. To implement this resource, the project uses an electronic engine management unit (also known as Electronic Control Unit - ECU) developed in 2013 by the Otto II project (PEREIRA, 2013). This ECU is responsible to control the engine of the respective vehicle, which allows the Cruise Control validation through a set of tests performed with the vehicle on an inertial dynamometer. However, prior to the Cruise Control design, this project focused on the ECU operation enhancement, in order to achieve the state of the art in electronic engine management units. For this goal, the project, during its first phase, performed several improvements on the control algorithms already existing in the firmware developed in 2013, such as idle speed control, electronic throttle valve control and engine starting control. At the same time, new features were fully implemented in firmware: torque control, closed loop air/fuel ratio control (lambda control), safety for the communication among ECU blocks, gear identification, support to OBD-II diagnostic, among others. In addition to the firmware development activities, the project, still in its first phase, developed a new software tool capable of monitoring several ECU parameters in real time, besides providing many functions, such as alternative board computer, an option to control the engine by simulating the throttle pedal, an option to change the idle speed and a function to automate the system identification test (task required for the Cruise Control design).
20

A molecular genetic appraisal of biodiversity and conservation units in freshwater fishes from southern Australia.

Hammer, Michael January 2008 (has links)
The freshwater fish fauna of southern Australia is characterised by low species richness and high endemism in groups displaying southern temperate, temperate-subtropical or temperate-tropical distributions. Comparatively few studies in Australia have incorporated modern molecular techniques to delineate species boundaries and define within-species conservation units. This is problematic because freshwater fishes are likely to show high levels of cryptic speciation and marked spatial sub-structure, and is information which is needed to conserve biological diversity and maintain the integrity of ecological communities and processes. The current study uses a ‘combined evidence’ approach, led principally by a set of nuclear genetic markers (allozymes), to assess species boundaries, spatial sub-structure and conservation units in obligate freshwater fishes from southern Australia. A literature review (Chapter 2) concerns the nature and effects of fragmentation in freshwater environments. It considers the implications for freshwater fishes and the types of extrinsic and intrinsic characteristics, both natural and human accelerated, that might drive population fragmentation and divergence. This theoretical framework is then applied to a suite of six largely co-occurring species groups with contrasting biological characteristics, and derive hypotheses about expected levels of genetic divergence across and within different drainages. Major findings Species of Retropinna (Chapter 3) are widespread and generally regarded as ‘common’ and mobile. Allozyme analyses revealed species-level and population-level sub-divisions, including five distinct species with contiguous ranges and no evidence of genetic exchange. Three occur along the eastern seaboard (including three instances of sympatry), another in coastal and inland southeastern Australia and Tasmania, and a fifth in the Lake Eyre Basin. There is no indication of a simple ‘tasmanica’ versus ‘semoni’ dichotomy, but instead a complex pattern involving discrete clusters for the Upper Murray plus Darling rivers, Lower Murray, Glenelg River and Tasmanian regions. These findings have implications for biodiversity, conservation and ecology. This chapter has been published in modified form (Marine and Freshwater Research 58, 327- 341). Nannoperca obscura (Chapter 4) is a small demersal fish with specialised habitat requirements. It is under threat of extinction, particularly in the western section of its range. Combined nuclear and matrilineal genetic data identified congruent within-species sub-structure, divided by patternsof distribution and biogeography. Four monophyletic mtDNA lineages, each distinct at multiple nuclear loci, indicate four Evolutionarily Significant Units (ESUs), namely (1) Lake Alexandrina in the Murray-Darling Basin (MDB), (2) Glenelg River, Millicent Coast River Basin and the outlying Mt Emu Creek, (3) Merri River and associated coastal streams, and (4) the eastern range section. Additional genetic and ecological data support multiple Management Units (MUs) within ESUs for individual or groups of river basins separated by marine barriers. Nannoperca australis (Chapter 5) has a similar character to its aforementioned congener, except that it occurs across a much wider area. Although generally common, particular populations are threatened, especially in the MDB. Allozyme analyses of 57 populations confirm the presence of two divergent species, with an eastern species containing two ESUs: (1) Gippsland and Flinders Island, and (2) Ansons River in northeastern Tasmania. The western species shows sub-structure across its range, including a separation of MDB and coastal populations as two heterogenous ESUs. The Lower Murray region (Mount Lofty Range streams and the Lower Lakes) harbours a remarkable level of between- and within-population diversity, underscoring its importance for conserving evolutionary potential. Mogurnda adspersa (Chapter 6) has been presumed extinct in South Australia since the early 1970s and has also been assumed lost from the southern MDB. This chapter reports on the rediscovery of M. adspersa from a wetland near the terminus of the Lower Murray, some 2500 river kilometres from the nearest known population. The nature and basic ecology of this population is documented, but the combined effects of drought and water abstraction recently have led to the probable extirpation of the wild population. A combined allozyme and mtDNA dataset confirmed the ‘nativeness’ of the population as a distinct sub-population (and MU), with a moderate level of allele heterogeneity. This information provides a platform for captive breeding as a conservation measure. The endemic genus Philypnodon (Chapter 7) contains two nominal species: P. grandiceps and the long recognised but only recently described P. macrostomus. The former is considered widespread and common (near ubiquitous), whereas the latter is more patchily distributed. Some tolerance to marine conditions is indicated, suggesting that there may be less sub-structure, but allozyme analyses of 269 individuals indicate the presence of multiple, species-level taxa within both described species. This obscures interpretations of existing ecological data. Although the presence of genetically-similar populations within and across some drainage divides indicates higher levels of gene flow, the pattern is complex and suggests historic genetic exchange between some but not other geographically-adjacent taxa. The freshwater blackfish genus Gadopsis (Chapter 8) has been a problem group for taxonomists, and it is unclear where the group is placed phylogenetically and how many species occur. Northern and southern forms on respective sides of the Great Dividing Range have been proposed, but with limited supporting evidence. Its dispersal ability (hence predicted genetic structure) is obscured by opposing life-history traits, including large body size (i.e. good swimming ability) versus habitat specialisation, demersal larvae and restricted home ranges. This chapter provides a genetic overview incorporating 61 locations across the range, and demonstrates unequivocally the presence of distinct northern and southern species of G. ‘marmoratus’. Moreover, distinct genetic discontinuities involving geographically abutting lineages indicate the likely presence of multiple ESUs within each species. A comparison of the allozyme data with previous mtDNA studies also identified two ESUs within G. bispinosus. Overall, considerable complexity is demonstrated signalling the need for a review of how the southern Australian fish fauna should be viewed, studied and protected. The genetic data also provide insight into the interplay of intrinsic biological characters (e.g. dispersal ability, population ecology) with historic and contemporary extrinsic environmental factors (e.g. fragmentation, biogeographic processes). Comparisons between and within traditionally-defined species are problematic, however, owing to multiple species-level splits and other genetic divisions that may have matching biological counterparts. Together with other reports in the literature, the findings presented herein have significant conservation implications, particularly given the rapid pace of human-mediated change in some regions that house high species and genetic diversity and unique evolutionary components, notably southeastern Queensland (especially the Mary River) and the lower River Murray in South Australia. Other regions displaying high genetic substructure or divergent populations include the Clarence River and Lachlan River in New South Wales; Gippsland, Goulburn River, Glenelg River and Mt Emu Creek in Victoria, and the Macquarie River and Ansons River in Tasmania. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339749 / Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2008

Page generated in 0.0967 seconds