Methanogenesis is the predominant terminal process of polymer degradation in anaerobic marine sediments depleted of sulfate; however, characterization of a marine consortium has not been previously reported. A marine methanogenic consortium consisting of fermentative, hydrogen-producing acetogenic and methanogenic bacteria is described. An acetotrophic methane-producing strain of bacteria was isolated. This isolate expresses three distinct morphovars: individual cocci, cell aggregates and communal cysts. Individual cocci are 1.9 µm in diameter and are nonmotile, but have fimbria-like structures. Cells have a thin protein cell wall. Acetate, methanol, methylamine, dimethylamine and trimethylamine are substrates for growth; formate and hydrogen are not. Sodium chloride and magnesium concentrations found in seawater are required for optimum growth. RNA homology values indicated that this isolate is a new species. Methanosarcina acetivorans is the proposed specific epithet. This is the first report of an acetotrophic methane-producing species indigenous to marine sediments. A method is described for mass culturing this and other acetotrophic methanogens using a pH auxostat. A strictly methylotrophic methane-producing strain was also isolated and is described. Only trimethylamine, dimethylamine, methylamine and methanol were substrates for growth. Cells were nonmotile, irregular cocci 1 µm in diameter and had a thin protein cell wall. Sodium chloride and magnesium concentrations found in seawater were required for optimum growth. Biotin was the only organic supplement required for growth in mineral medium. Fe was required for growth; Ni and Co were stimulatory. This isolate is a new genus based on RNA homology. Methanococcoides is the proposed genus and Methanococcoides methylutens is the specific epithet. Population studies suggest that this species is uniquely adapted for methylated amine degradation in marine sediments. The phylogenetic relationships of M. acetivorans, M. methylutens and other acetotrophic and methylotrophic species were determined by RNA and DNA homology techniques. Phylogenetic and physiological results in this study indicated that the population of methanogenic bacteria in marine sediments is both unique and equally diverse as the population of freshwater methanogenic species. / Ph. D.

In this study, the effects of writing ability and mode of discourse of cognitive capacity engagement were investigated. Sixty-three college freshmen of varying writing abilities (basic, average, and honors) were randomly assigned to experimental treatments (descriptive writing, narrative writing, and persuasive writing). Using the secondary task method, it was found that writing ability differentially affects cognitive capacity engagement across modes. For example, honors writers were least engaged when writing descriptive essays but were most engaged when writing persuasive essays whereas average writers were most engaged when writing descriptive essays but were least engaged when writing narrative essays. Analytic quality scores and engagement were related and results were interpreted in the context of schema theory to estimate the learning potential of a given mode of discourse. Also, engagement and syntactic complexity treasures were related. It was found that as words per clause increased, engagement also increased; whereas, as clauses per T-unit increased, engagement decreased. / Ed. D.

The purpose of this study was to compare and to describe deaf versus hearing readers' sensitivity to contextual build-up by examining each group's successive approximations of deleted noun meanings as constructed in cumulative cloze tasks. The methodology of this study, a 2 X 5 X 2 factorial design, focused on successive predictions of deleted noun meanings in five cumulative cloze tasks completed by five deaf and five hearing readers at fourth-, sixth-, eighth-, tenth-, and twelfth-grade levels. Both for deaf and hearing readers, sentences within the five individual cumulative cloze passages where the greatest gain in comprehension occurred (MG sentences) comprised an alternative cloze test for five other readers at all five grade levels. The results indicate that both deaf readers and hearing readers predict meaning more accurately given passage-level versus sentence-level contextual constraints. On this particular cumulative cloze task, deaf readers at grades eight, ten, and twelve performed similarly to hearing readers at grades eight, ten and twelve respectively. However, deaf readers in grades four and six performed significantly lower than their hearing counterparts. Hearing readers at all five grade levels and deaf readers at the eighth-, tenth-, and twelfth-grade levels increased in cumulative cloze accuracy as the number of exposure point in passage-level text increased. By the sixth, final exposure points in passage-level text, no significant differences were found in deaf versus hearing readers' predictions of target nouns at grade levels eight, ten, and twelve. Deaf readers tended to abandon correct choices after predicting target nouns more often than did hearing readers. Additionally, deaf readers returned to abandoned correct choices less often than did hearing readers. Both semantic and grammatical acceptability of cumulative cloze responses improved for deaf as well as for hearing readers as the amount of available contextual information increased in passage-level text. MG sentences, proved to be more semantically and grammatically acceptable under passage-level versus sentence-level contextual conditions. The results of this study indicate that given passage-level contextual constraints, deaf as well as hearing readers construct meaning similarly. / Ed. D.

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« La technologie, prise dans le sens global du terme, est un domaine offrant un vaste champ d'étude pour ceux et celles qui s'intéressent à la culture matérielle d'une population. Elle permet, grâce à l'analyse de la tradition gestuelle, de cerner l'organisation physique et sociale qui prévaut à l'intérieur d'un milieu particulier de travail. La méthode d'analyse présentée dans cette étude a pour but de cerner la notion même de la technologie, laquelle peut se résumer en une technique d'exécution d'un travail mise en relation avec le contexte économique et social dans lequel elle se déroule. Afin de mieux comprendre le sujet de cette étude, il a été choisi d'analyser la technologie du travail de la fonte selon les méthodes couramment employées au cours du 19ième siècle. Ces recherches ont été effectuées à la Fonderie St-Anselme, dans le comté de Dorchester, où les employés utilisent encore les techniques adoptées depuis l'ouverture de la fonderie en 1844. Grâce aux enquêtes ethnographiques faites à cet endroit, il a été possible de relever diverses données se rapportant à la technologie telles la gestuelle relative à la fabrication des moules de sable et de la fonte liquide, les chaînes opératoires régissant la réalisation d'un objet en fonte, la répartition des aires de travail ainsi que la présence de pratiques religieuses traditionnelles. L'ensemble de ces données cumulées avec celles d'ordre historique a permis de dresser un tableau général de l'histoire de l'industrie de la fonte au cours du 19ième et début du 20ième siècle. Cette recherche se termine en ouvrant la voie à un autre domaine d'étude voulant mettre en relation la productivité des fonderies et l'amélioration du mode de vie des habitants grâce aux articles de fonte qui ont envahi le marché au cours de la période étudiée. La présente étude porte sur la technologie artisanale d'articles de fonte au Québec au cours de la période couvrant le début du 19ième siècle jusqu'au milieu du 20ième. Elle veut être, avant tout, une contribution à l'analyse des techniques employées et de leurs importances au sein du milieu dans lequel elles sont pratiquées. A travers la description ethnographique et l'analyse de la technique du moulage en sable, je veux montrer qu'il existe une voie de recherche entre la technologie telle que couramment appliquée, c'est-à- dire une description des techniques comme fin en soi, et une approche voulant replacer la culture matérielle dans son contexte social et économique. »--Pages préliminaires

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Québec Université Laval, Bibliothèque 2015

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The need for a model capable of providing educators and legislators with objective data concerning the quality of public schools in West Virginia became critical after the Pauley v. Bailey decision was handed down. County school districts across the state had interpreted evaluation instruments in various ways resulting in information that was a product of the evaluators’ backgrounds and experiences and lacked objectivity. The purpose of this study was to develop and field test an evaluation model capable of assessing secondary school facilities in West Virginia to determine compliance with standards established in the Master Plan for Public Education for secondary school facilities. The model for Secondary School Facilities in West Virginia was criteria referenced using standards established in the Master Plan for Public Education. The model was field tested in three county school districts. During the field testing process each facility was evaluated two times. One evaluation was completed by the school principal while the second evaluation was conducted by the researcher. An inservice model was designed to standardize the application process evaluators would follow when using the Evaluation Model for Secondary School Facilities in West Virginia and all local evaluators were required to participate in the inservice program. Data obtained in the field testing process was checked for consistency and objectivity. Follow-up interviews were conducted with local evaluators to gather information that would permit the refinement of both the inservice model and the Evaluation Model. The use of the Evaluation Model for Secondary School Facilities in West Virginia will provide educators with information that will assist in the development of statewide priorities for public school facilities. Recommendations were made in accordance with the findings of the study. / Ed. D.