1,622 research outputs found
A Phenomenological Study of Professional and Practical Changes Experienced by Teachers Involved with Action Research in a Learning Community Master’s Program
In the United States, the majority of teachers have a master’s degree or higher. However, there exist concerns in the literature that having an advanced degree does not make teachers better. There thus needs to be a way to improve the outcome of a master’s degree in education so that teachers do advance their practice and bring change to their classrooms as a direct result of their experience in a master’s degree program. By focusing on the use of action research in a learning community, the intent of the present phenomenological study was to discover changes that occurred in teachers involved in action research in a learning community setting while obtaining their master’s degree. The sample consisted of teachers that have attained their master’s degree from a program involving both action research and the learning community setting offered at the same comprehensive regional university in the Upper Midwest. Based on the extant literature, it was expected that the changes experienced by the teachers may include variations in their teaching practice, professional development, collegial relationships, and leadership roles. The results of the study confirmed these changes and highlighted the development of personal control as an essential quality of effective teachers. The teachers involved in the study considered their perceived improvement as transformative and a direct result of their experience in the master’s degree program
PREDICTED FUTURE ECONOMIC IMPACTS OF BIOLOGICAL CONTROL OF LEAFY SPURGE IN THE UPPER MIDWEST
The Leafy Spurge Biological Control program was designed to use insects and plant diseases from the plant's original European habitat to control infestations in the United States. The widespread adoption of biological agents to combat leafy spurge and the initial success in reclaiming previously infested land has prompted an evaluation of the potential future economic benefits of the biological control of leafy spurge in the Upper Midwest. Based on expert opinion and historical data, leafy spurge in Montana, North Dakota, South Dakota, and Wyoming was projected to infest 1.85 million acres, of which, 65 percent was estimated to controlled with biological agents by 2025. Based on a survey of county weed board personnel, North Dakota and Wyoming are further advanced in the use of biological control than Montana and South Dakota. Recovery of rangeland outputs resulting from the biological control of leafy spurge was estimated to create 5.6 million annually. By 2025, total economic impacts of the Leafy Spurge Biological Control Program were estimated at $58.4 million (1997 dollars) annually in the four-state region. An additional 876 full-time equivalent secondary jobs would be created as result of the program. Although the economic estimates generated are based on expert opinion and remain sensitive to assumptions regarding the future efficacy of the biological control of leafy spurge, initial evidence suggests the program will be an economic success regardless of the eventual level of control. The assessment of the economic value of the biological control of leafy spurge would benefit from incorporation of additional information as the overall understanding of the biological control process grows.biological control, leafy spurge, economic impacts, Upper Midwest, Resource /Energy Economics and Policy,
ECONOMICS OF HERBICIDE CONTROL OF LEAFY SPURGE (EUPHORBIA ESULA L.)
Leafy spurge (Euphorbia esula L.), a widely established exotic, noxious, perennial weed, is a major threat to the viability of commercial grazing and to beneficial outputs of wildlands in the Upper Great Plains. Herbicide treatments are often recommended based upon measures of physical control rather than on economic criteria. A deterministic, bioeconomic model was developed to evaluate the economic viability of current herbicide control strategies for leafy spurge. Control viability is highly site specific but falls into three categories. First, broadcast herbicide treatment may result in positive net returns for some grazing situations, especially small infestations on highly productive land, in the Upper Great Plains. Second, treating the perimeter to prevent patch expansion is viable in some situations when treating the entire infestation is not viable. Finally, for well-established infestations on less-productive land the best alternative, from an individual landownerÂ’'s perspective, is to not treat leafy spurge with herbicide and bear the increasing productivity losses.Crop Production/Industries,
Economic Impact of Leafy Spurge on Wildland in Montana, South Dakota, and Wyoming
Resource /Energy Economics and Policy,
Adapting Appropriation Water Law to Accommodate Equitable Consideration of Instream Flow Uses
The increasing public interest in naturally flowing streams has fostered efforts to obtain their protection under existing state water laws. In this study, the water laws of Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming were examined and compared 1) with each other, and 2) against a set of aleitn criteria, to assess shortcomings in accommodating instream flow protections. It was determined that the appropriation system has the essential features of and ambodies legal principles that should allow the accommodation of instream flow values but, at this time, purchase of existing rights or the exercise of governmental reservation/withdrawal/appropriation authorities seem to be the primary options. Legislative, judicial, and adminsitrative strategies for protecting instream flows apart from the normal appropriation process were reviewed. Certain legislative and administrative strategies hold premise as supplementary to the standard appropriation procedure. Likewise, private sector strategies utilizing contracts, easements, purchase of development rights, etc., need to be more thoroughly considered. Where instream flow protections do not justify preemptive rights and strategies, and if hydrologic imperatives are properly observed, the state administered appropriation systems can accommodate the instream flow needs. However, the need for better technical information for establishing benficial need for the many instream values, and for use in projecting the biologic-hydrologic consequences of particular instream flow regimes remains a stumbling block to the accommodation process
Natural Salinity Removal Processes in Reservoirs
A small but significant amount of salinity removal has been reported by various authors to occur in mainstem Colorado River reservoirs. Recalculation of some of these salinity budgets, together with a review of the data bases used, usggests taht removal has not often been conclusively demonstrated. Laboratory microcosm experiments and field data indicate that calcium carbonate precipitation, perhaps with some coprecipitation of magnesium carbonate, is the mechanism responsible for most of the salinity removal in Oneida Reservoir, Idaho. Coprecipitation processes (including ion exchange), coagulation, and bioassimilation do not appear to be important natural salinity removal mechanisms. Finally, loss of calcium, relative to monovalent cations, may decrease water quality for irrigation purposes through increasing the sodium adsorption ratio (SAR), despite a pross decrease in the TDS. The potential role of various reservoir operation options in managing natural salinity removal processes and the value of such removal is discussed
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Zinc, copper and manganese in the razor clam, Siliqua patula
Zinc, copper and manganese concentrations were measured by atomic absorption spectroscopy in Siliqua patula collected during May, 1970 through May, 1971. Individual clams were analysed to determine the degree of variation among individuals, Statistical analysis proved the variation to be highly significant. Monthly composite samples of 18 clams were collected from three sites along the Washington-Oregon coast. The samples were analysed to examine differences in concentration among two general groups of tissue, collection sites and monthly concentrations within a site.
Significant differences were found between the tissue groups, with copper and manganese being consistently higher in portion B
(gills, liver, digestive system and reproductive tissue). Zinc was generally found in higher concentration in portion A (foot, neck, mantle, adductor muscle and reproductive tissue). A statistically significant difference was also noted between
the three sites, however no pattern in the concentration was apparent. These results may indicate that the variation between sites reflects only the high degree of variability among individuals. Statistically significant differences were also noted between the months examined within each site. There appeared to be a general trend of increasing concentration in Spring and Summer for all three elements. Prior investigations indicate that the razor clam undergoes most of its growth activity in early Spring and most of its reproductive activity in late Spring and early Summer. It is possible that the increased concentration in Spring and Summer is responding to increased requirements due to changes in metabolic rate brought about by increased growth and the reproductive activity. However it is equally important to recognize that the monthly variation could be reflecting the 'variation among individuals
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Selective incorporation of proteinaceous over nonproteinaceous cationic amino acids in model prebiotic oligomerization reactions.
Numerous long-standing questions in origins-of-life research center on the history of biopolymers. For example, how and why did nature select the polypeptide backbone and proteinaceous side chains? Depsipeptides, containing both ester and amide linkages, have been proposed as ancestors of polypeptides. In this paper, we investigate cationic depsipeptides that form under mild dry-down reactions. We compare the oligomerization of various cationic amino acids, including the cationic proteinaceous amino acids (lysine, Lys; arginine, Arg; and histidine, His), along with nonproteinaceous analogs of Lys harboring fewer methylene groups in their side chains. These analogs, which have been discussed as potential prebiotic alternatives to Lys, are ornithine, 2,4-diaminobutyric acid, and 2,3-diaminopropionic acid (Orn, Dab, and Dpr). We observe that the proteinaceous amino acids condense more extensively than these nonproteinaceous amino acids. Orn and Dab readily cyclize into lactams, while Dab and Dpr condense less efficiently. Furthermore, the proteinaceous amino acids exhibit more selective oligomerization through their α-amines relative to their side-chain groups. This selectivity results in predominantly linear depsipeptides in which the amino acids are α-amine-linked, analogous to today's proteins. These results suggest a chemical basis for the selection of Lys, Arg, and His over other cationic amino acids for incorporation into proto-proteins on the early Earth. Given that electrostatics are key elements of protein-RNA and protein-DNA interactions in extant life, we hypothesize that cationic side chains incorporated into proto-peptides, as reported in this study, served in a variety of functions with ancestral nucleic acid polymers in the early stages of life
Adapting Water Services to Urban Growth: A Case Study of Salt Lake County
Urbanizing areas thorughout the nation are considering governmental reorganization or consolidation to coordinate planning and improve the cost effectiveness of the delivery of public services. More efficient water supply and wastewater services may become important in the political debate over reorganization. However water factors figure politically, accomplished reorganizations must carefully plan for efficent provision of water services. This study profiles the structure and interactions of municipalities and water service agencies in Utah\u27s Salt Lake County during the 1970s. Both 1975 and 1978 attempts to consolidate Salt Lake City and the unincorporated areas of the county failed. The voting patterns, interest ground positions, and issues are examined. One major water issue surfaced in a concern that service jurisdictions and financial obligations were not sufficiently defined to protect the communities previously bound through water service agreements but excluded from the consolidated government. Additionally, the proposed dissolution of the County Water Conservancy District raised doubts on the division of equity in water rights and distribution facilities. Any large water development stabilizes institutional arrangements to a degree which may become a financial and legal contrainst to desired change. Overall, nonwater issues dominated the decision in this water sensitive area. This implies that water service jurisdictional alignments are set by political decisions based on nonwater considerations. Water utilities must do their best to be effective in the resulting context
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