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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.
601

Evolution and Distribution of Phenotypic Diversity in the Venom of Mojave Rattlesnakes (Crotalus scutulatus)

Strickland, Jason 01 January 2018 (has links)
Intraspecific phenotype diversity allows for local adaption and the ability for species to respond to changing environmental conditions, enhancing survivability. Phenotypic variation could be stochastic, genetically based, and/or the result of different environmental conditions. Mojave Rattlesnakes, Crotalus scutulatus, are known to have high intraspecific venom variation, but the geographic extent of the variation and factors influencing venom evolution are poorly understood. Three primary venom types have been described in this species based on the presence (Type A) or absence (Type B) of a neurotoxic phospholipase A2 called Mojave toxin and an inverse relationship with the presence of snake venom metalloproteinases (SVMPs). Individuals that contain both Mojave toxin and SVMPs, although rare, are the third, and designated Type A + B. I sought to describe the proteomic and transcriptomic venom diversity of C. scutulatus across its range and test whether diversity was correlated with genetic or environmental differences. This study includes the highest geographic sampling of Mojave Rattlesnakes and includes the most venom-gland transcriptomes known for one species. Of the four mitochondrial lineages known, only one was monophyletic for venom type. Environmental variables poorly correlated with the phenotypes. Variability in toxin and toxin family composition of venom transcriptomes was largely due to differences in transcript expression. Four of 19 toxin families identified in C. scutulatus account for the majority of differences in toxin number and expression variation. I was able to determine that the toxins primarily responsible for venom types are inherited in a Mendelian fashion and that toxin expression is additive when comparing heterozygotes and homozygotes. Using the genetics to define venom type is more informative and the Type A + B phenotype is not unique, but rather heterozygous for the PLA2 and/or SVMP alleles. Intraspecific venom variation in C. scutulatus highlights the need for fine scale ecological and natural history information to understand how phenotypic diversity is generated and maintained geographically through time.
602

An analysis of land use in central-north Florida : a study in conservation /

Rose, Harold Milton January 1960 (has links)
No description available.
603

Nonformal environmental education in natural resources management : a case study in the use of interpretation as a management tool for a state nature preserve system /

Olson, Edward Charles January 1983 (has links)
No description available.
604

A descriptive analysis of selected teacher/student behaviors during adventure activity - the program of outdoor pursuits /

McHattie, Garth Sherwin January 1978 (has links)
No description available.
605

Development of an Underground Automated Thin-Seam Coal Mining Method

Holman, Darren Wayne 03 June 1999 (has links)
It is predicted that coal mining in Southwest Virginia, and the economic stability that it brings to the area, will continue to decline over the next decade unless an environmentally sound, and economically viable means can be found to extract seams of high quality coal in the thickness range of 14 to 28 inches. Research into autonomous machine guidance, coupled with developments of thin-seam mining equipment, offer new opportunities for devising mining layouts suitable for extracting these thin seams in a cost effective manner. These layouts must involve well-planned transportation and ventilation routes that will allow safe conditions for personnel. This implies that the mining face, where coal is extracted, will be completely automated, ensuring the safety of the workers. This thesis presents a brief overview of current technologies utilized for underground coal mining in the United States. This is followed by a review of developments in highwall mining that are potentially applicable in underground mining of thin seams. Some past attempts at thin seam mining are discussed, and evaluated for their short comings. An overview of the more recent advances in the guidance systems for use in autonomous mining machines is also presented. The new advances that several manufacturers are developing to address the integration of mining and continuous haulage systems are also investigated. That background is employed in devising a conceptual mining system for the underground mining of coal seams in the 14 to 28 inch range of thickness. This thesis proves that adapting new technologies and concepts from existing ones can lead to meaningful advances in the field of natural resources recovery. This system utilizes a newly designed panel layout that takes into account haulage, supplying, ventilation, equipment, and machine guidance. This system is proposed to show that new ways can be developed to take advantage of the reserves in the 14 to 28 inch range of thickness. This shows that new technology and design innovation can turn currently uneconomic resources, into economic reserves. This kind of innovation is what is needed to keep this region of Southwest Virginia economically viable. This system is a huge step in the direction that thin-seam research needs to take. Most of the equipment suggested for this proposed system is already available. / Master of Science
606

Effects of landscape change on corsac foxes in Mongolia

Lkhagvasuren, Myagmarjav 01 January 2015 (has links)
Landscape change affects the distribution of wildlife and represents a conservation concern, especially in Asia, which is experiencing rapid development. In Mongolia, mining, livestock grazing, infrastructure development and climate change represent major drivers of change that will impact habitats and few tools exist to predict how wildlife will respond. I examined the impacts of landscape change on the corsac fox (Vulpes corsac) in a steppe region of Mongolia. The corsac fox occurs widely throughout northern Asia, but has experienced declines in many regions and remains one the least studied canids. I addressed two questions: 1) how do common features of a landscape, such as habitats, topography, herder camps, and roads, shape the distribution of the species? and 2) how will changes in those features affect distribution in the future? I collected locations of foxes from radio-collared animals, scat surveys, and opportunistic sightings in Ikh Nart Nature Reserve, then used maximum likelihood methods and model selection techniques to develop a model that predicts occupancy probability. I then applied the model to simulations of landscape change. I collected 1,965 locations and examined 19 candidate models. The model with the most support indicated that occupancy is best described by the additive combination of shrublands, open plains, tall grasslands, and rocky habitat. Models with other covariates (camps, roads, and ruggedness) had little support. A Receiver-Operator-Characteristic plot of model performance had an Area Under the Curve of 77%, indicating that the model predicted occupancy better than expected by chance. Average occupancy across the reserve was 22% under current conditions. Incremental reductions in shrubland, open plains, and tall vegetation resulted in occupancy declines with average occupancy being 7%, 13%, and 14%, respectively, when these habitats were completely absent. The loss of all three habitats due to the desertification of the landscape through climate change resulted in an average occupancy of 7%. The results provide the first model of corsac fox occupancy, which can be used to quantitatively examine distribution and impacts of change in other parts of the species' range. In Ikh Nart, results suggest that climate change poses the greatest threat to the species as it is expected to reduce high quality habitats and confine corsac foxes to areas with high competition from red foxes.
607

Governance structures and management dynamics in large scale Common Property Resources: cases from Lake Victoria Fishery, Mwea Rice Irrigation System and Laikipia Group Grazing Lands in Kenya

Mugiira, Rose Kathambi January 2017 (has links)
Research Thesis  Submitted  in  Fulfilment  of  the  Requirements  for  the  Degree  of  Doctor  of   Philosophy  in  Economics, School of Economic & Business Sciences Faculty of Commerce, Law and Management University of Witwatersrand, Johannesburg, SA / The world is facing a sustainability crisis due to depletion and degradation of environmental and natural resources faster than they can be generated. Many of these resources are not partitioned by private property rights, and are held as state property, common property, or as open-access. Common Property Resources (CPRs) have two distinct attributes: (1) limited or nontrivial exclusion (it is difficult to exclude multiple individuals or users from appropriating from the resource) and (2) substractability (the resource features rivalry in consumption), meaning that appropriation by one reduces the overall resource availability and thus, subtracts from what can be appropriated by others. Examples include fisheries, grazing lands, irrigation systems, and ground water basins. Because no one has property rights or control over such resources, users of CPRs are frequently assumed to be caught in an inescapable dilemma - overexploitation of the resource. Thus, unlike the ‘invisible hand’ of Adam Smith in competitive markets, in the case of CPRs the self-interested behavior does not yield economic efficiency or optimal outcome or Pareto optimality. This study sought to understand the evolution of management dynamics and operation of governance structures developed by resource users and other stakeholders in three large scale CPRs in Kenya. The objectives are to (1) examine the evolution of management dynamics. (2) Examine the management model applied and its functioning. (3) Explore the governance structures and challenges of implementing them. (4) Explore critical variables related to user groups, institutional arrangements and external environment in the resource system. (5) Suggest measures to improve on the management and governance of the resource system. In addition, the study gives a comparative analysis of the management models applied in the three CPR systems. The general theoretical literature on CPRs has focused mainly on two basic but important conditions or categories. First, small scale communally owned and governed resources, in ii terms of the physical or geographical size of the resource system with well-defined boundaries. Secondly, group or users size, characterized by small numbers with similar identities and interests. This study therefore, contributes to literature by using large scale CPR case studies in terms of physical size of resource system and number of users and examining the evolution and dynamics in the management model and governance structures. A Qualitative Research (QR) methodology is adopted and analytical tools of institutional analysis and an empirical foundation based on field data applied. A survey research design is used. Both primary and secondary data was sourced and a pilot study was conducted to test reliability of research instruments. Data is documented, compiled and presented in form of tables, figures and general descriptions. Data analysis and synthesising is done by working through the data to arrive at a conclusion to answer the research questions and achieve the purpose of the study. The study findings show that management and governance issues in the three CPRs have evolved over time both in terms of the scale and involvement of other stakeholders in decision making process in the resource system. Specifically, the collaborations among state agencies, other stakeholders and resource users through their associations has enabled monitoring and enforcement not only be effective but also legitimate and consequently, lead to sustainable resource use. The management models used in the three CPR case studies are identified as the Partnership Fisheries Management (PFM) in Lake Victoria fishery, Participatory Irrigation Management (PIM) in Mwea Rice Irrigation Scheme and Holistic Management Framework (HMF) in Laikipia group grazing lands. The governance structures applied in the three CPRs are generally position, boundary, choice or authority, aggregation, information, payoff and scope rules. The degree of application of each set of rules however, depends on the nature of the resource system. They are designed, developed, implemented, monitored, enforced, sanctioned and arbitrated by the resource users, state lead agencies, departments and ministries iii and other stakeholders or actors. Each of these actors are involved in varying degrees in the various phases depending on their role and interest in the resource system. The management and governance structures can be strengthened and improved by enhancing certain administrative, health, safety, environmental issues and increased state support and involvement in the resource system. The co-management model design which is applied in the three CPRs yield various benefits to the resource-dependent community, public, state and resource system because it incorporates state and local (resource users) managers in decision making. However, the degree of participation of other stakeholders, challenges faced and other internal and external factors, depend on the nature of CPR, ownership and control of the CPR by resource users and the technical infrastructural investments required for the operation of the system. These results add to existing knowledge on Sustainable Development (SD) environment nexus by providing facts to multidisciplinary environmental and natural resources scholars regarding the dynamics of large scale CPR systems. Provide an in depth understanding of CPR management issues for the formulation of national strategies for SD, fisheries, Arid and Semi-Arid Lands (ASALs), and irrigation farming. Lastly, they provide ways of responding to increasing challenges of shared water resources (Lake Victoria) in addition to strengthening of relations within the East African Community (EAC). Key words: Actors, bio-physical and community attributes Common Property Resources, governance structures, institutions, large scale, management models, resource users, resource systems / GR2018
608

Geographic survey of resource use in Monroe County, Ky.

Unknown Date (has links)
"The author will be making use of a relatively new experimental technique of geographical analysis. Answers will be sought to such questions as--What has influenced the county to become what it is? Is it different from other counies in the same region? If so, why? Is the county utilizing its resources? And finally, what is the general level of living in this county and what factors have determined it?"--Introduction. / Typescript. / "Submitted to the Graduate Council of Florida State University in partial fulfillment of the requirements for the degree of Master of Sciences under Plan II." / "August, 1949."
609

Natural resources in a competitive economy.

Berck, Peter January 1976 (has links)
Thesis. 1976. Ph.D.--Massachusetts Institute of Technology. Dept. of Economics. / Microfiche copy available in Archives and Dewey. / Includes bibliographical references. / Ph.D.
610

Late Pleistocene and Holocene Bison of Grand Canyon and Colorado Plateau: Implications from the use of Paleobiology for Natural Resource Management Policy

Martin, Jeffrey M 01 May 2014 (has links)
Bison spp. (bison) fossils are scarce on the Colorado Plateau, especially within the greater Grand Canyon region. Because of the poor fossil record for bison on the plateau and in Grand Canyon National Park, various resource managers have surreptitiously designated bison a nonnative and human-introduced species. The lack of evidence for bison seems to be the result of collection bias rather than a true lack of bison remains. Today, Grand Canyon National Park has a neighboring herd of 350 bison that have meandered unwantedly onto National Park lands from neighboring Forest Service and State of Arizona lands. This study spatiotemporally illustrates bison are recently native to the greater Grand Canyon area based on previously misidentified specimens in archaeological collections. Data here may require resource managers to reconsider whether or not bison should be reconsidered a native species to the Grand Canyon National Park and elsewhere on the Colorado Plateau.

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