999 resultados para theses and dissertations
Resumo:
In a period of increasing concern about food safety, food poisoning outbreaks where unpasterurized apple cider or apple juice was found contaminated with Escherichia coli 0157:H7 reinforces the need for using the best technologies in apple cider production. Most apple cider is sold as an unpasteurized raw product. Because of their acidity, it was believed that juice products do not usually contain microorganisms such as E. coli 0157:H7, Salmonella, and Crytosporidium. Yet all of these foodborne pathogens are capable of being transmitted in unpasteurized juices. It is known that these pathogens can survive for several weeks in a variety of acidic juices. Although heat pasteurization is probably the best method to eliminate these pathogens, it is not the most desirable method as it changes sensory properties and also is very costly for small to mid-sized apple cider processors. Pasteurization of apple cider with Ultraviolet Irradiation (UV) is a potential alternative to heat pasteurization. Germicidal W irradiation is effective in inactivating microorganisms without producing undesirable by-products and changing sensory properties. Unpasteurized raw apple cider from a small local processor was purchased for this study. The effects of physical parameters, exposure time and dosage on the W treatment efficacy were examined as well as the effects of the UV light on apple cider quality. W light with principal energy at a wavelength of 254.7 nm, was effective in reducing bacteria (E .coli, ATCC 25922) inoculated apple cider. The W dosage absorbed by the apple cider was mathematically calculated. A radiation dose of 8,777 μW-s/cm2 reduced bacteria an average of 2.20 logs and in multiple passes, the FDA mandated 5-log reduction was achieved. Sensory analysis showed there was no significant difference between the W treated and non-treated cider. Experiments with W treated apple cider indicated a significant (p < 0.01) extension of product shelf life through inhibition of yeast and mold growth. The extension of the researched performed is applicable to other fruit juice processing operations.
Resumo:
This research project sought to answer the primary research question: What occurs when the music program in a church changes its emphasis from performance to education? This qualitative study of a church choir included participant observation of Wednesday evening and Sunday morning rehearsals over a 12 week period, individual interviews, group interviews, written responses, and written and visual assessment of musical skills. The goal was a rich description of the participants and emerging themes resulting from the shift in emphasis. Analysis of data occurred through inductive processing. Data was initially coded and then the codes were categorized into sub-themes, and finally into major themes. Early analysis of the data began with reflection in a researcher journal. Following the completion of the study the journal was entered into a word processor, as were transcriptions of videotaped rehearsals, and written reflections from the participants. After all data had been reviewed repeatedly and entered into the word processor, it was coded, reexamined, and finally categorized into sub-themes and themes. After coding and identification of major themes and sub-themes the finding were challenged by looking for disconfirming evidence. Finally, after the completion of the analysis stage, member checks were conducted. The results of the analysis of data revealed themes that could be associated either with the choir or the director. The key themes primarily associated with the choir were: Response to the change in rehearsal format; Attitude toward learning; Appropriateness of community learning model; and, Member's perceptions of the results of the program. The key themes associated with the director were identified as: Conductor assuming the role of educator; Conductor recognizing the choir as learners; Conductor treating rehearsals as a time for teaching and learning; and, Conductor's perception of the effectiveness of the change in focus. The study concluded that a change in focus from performance to education did not noticeably improve the sound of the choir after twelve-weeks. There were however, indications that improvements were being made by the individual members. Further study of the effects over a longer period of time is recommended.
Resumo:
Current research in the domain of geographic information science considers possibilities of including another dimension, time, which is generally missing to this point. Users interested in changes have few functions available to compare datasets of spatial configurations at different points in time. Such a comparison of spatial configurations requires large amounts of manual labor. An automatic derivation of changes would decrease amounts of manual labor. The thesis introduces a set of methods that allows for an automatic derivation of changes. These methods analyze identity and topological states of objects in snapshots and derive types of change for the specific configuration of data. The set of change types that can be computed by the methods presented includes continuous changes such as growing, shrinking, and moving of objects. For these continuous changes identity remains unchanged, while topological relations might be altered over time. Also discrete changes such as merging and splitting where both identity and topology are affected can be derived. Evaluation of the methods using a prototype application with simple examples suggests that the methods compute uniquely and correctly the type of change that applied in spatial scenarios captured in two snapshots.
Resumo:
Structural composite lumber (SCL) products often possess significantly higher design values than the top grades of solid lumber, making it a popular choice for both residential and commercial applications. The enhanced mechanical properties of SCL are mainly due to defect randomization and densification of the wood fiber, both largely functions of the size, shape and composition (species) of the wood element. Traditionally, SCL manufacturers have used thin, rectangular elements produced from either moderate density softwoods or low density hardwoods. Higher density hardwood species have been avoided, as they require higher pressures to adequately densify and consolidate the wood furnish. These higher pressures can lead to increased manufacturing costs, damage to the wood fiber and/or a product that is too dense, making it heavy and unreceptive to common mechanical fastening techniques. In the northeastern United States high density, diffuse-porous hardwoods (such as maple, beech and birch) are abundant. Use of these species as primary furnish for a SCL product may allow for a competitive advantage in terms of resource cost against products that rely on veneer grade logs. Proximity to this abundant and relatively inexpensive resource may facilitate entry of SCL production facilities in the northeastern United States, where currently none exist. However, modifications to current strand sizes, geometries or production techniques will likely be required to allow for use of these species. A new SCL product concept has been invented allowing for use of these high density hardwoods. The product, referred to as long-strand structural composite lumber (LSSCL), uses strands of significantly larger cross sectional areas and volumes than existing SCL products. In spite of the large strand size, satisfactory consolidation is achieved without excessive densification of the wood fiber through use of a symmetrical strand geometric cross-section. LSSCL density is similar to that of existing SCL products, but is due mainly to the inherent density of the species, rather than through densification. An experiment was designed and conducted producing LSSCL from both large (7/16”) and small (1/4”) strands, of both square and triangular geometric cross sections. Testing results indicate that the large, triangular strands produce LSSCL beams with projected design values of: Modulus of elasticity (MOEapp) – 1,750,000 psi; Allowable bending stress (Fb) – 2750 psi; Allowable shear stress (Fv) – 260 psi. Several modifications are recommended which may lead to improvement of these values, likely allowing for competition against existing SCL products.
Resumo:
The present study provided further information about stuttering among bilingual populations and attempted to assess the significance of repeated oral-motor movements during an adaptation task in two bilingual adults. This was accomplished by requesting that bilingual people who stutter to complete an adaptation task of the same written passage in two different languages. Explored was the following research question: In bilingual speakers who stutter, what is the effect of altering the oral-motor movements by changing the language of the passage read during an adaptation task? Two bilingual adults were each requested to complete an adaptation task consisting of 10 readings in two separate conditions. Participants 1 and 2 completed two conditions, each of which contained a separate passage. Condition B consisted of an adaptation procedure in which the participants read five successive readings in English followed by five additional successive readings in Language 1 (L1). Following the completion of the first randomly assigned condition, the participant was given a rest period of 30 minutes before beginning the remaining condition and passage. Condition A consisted of an adaptation procedure in which the participants read five successive readings in L1 followed by five additional successive readings in English. Results across participants, conditions, and languages indicated an atypical adaptation curve over 10 readings characterized by a dramatic increase in stuttering following a change of language. Closer examination of individual participants revealed differences in stuttering and adaptation among languages and conditions. Participants 1 and 2 demonstrated differences in adaptation and stuttering among languages. Participant 1 demonstrated an increase in stuttering following a change in language read in Condition B and a decrease in stuttering following a change in language read in Condition A. It is speculated that language proficiency contributed to the observed differences in stuttering following a change of language. Participant 2 demonstrated an increase in stuttering following a change in language read in Condition A and a minimal increase in stuttering following a change in language read in Condition B. It is speculated that a change in the oral-motor plan contributed to the increase in stuttering in Condition A. Collectively, findings from this exploratory study lend support to an interactive effect between language proficiency and a change in the oral-motor plan contributing to increased stuttering following a change of language during an adaptation task.
Resumo:
The present study sought to investigate the ways in which social anxiety impedes the development of romantic relationships across adolescence. Previous research has demonstrated a natural progression for romantic associations during adolescence in which teens transition from same- to mixed-sex peer groups, and finally to dyadic relationships with romantic partners (Connolly, Furman, Konarski, 2000; Dunphy, 1963). This model of development was the basis for the present investigation. Social anxiety was examined in terms of how it impacted affiliations at the same- and mixed sex peer group levels, and ultimately the formation of romantic relationships. This project involved administering a series of questionnaires and rating scales to students enrolled in the 9th through \2l grades. Participants included 457 adolescents (196 males, 261 females) recruited from public high schools in the state of Maine. The questionnaires assessed social anxiety, peer acceptance, heterosocial competence, gender composition of adolescent peer networks, dating history, and relationship quality with significant others in the adolescent's life. Higher levels of social anxiety were expected to be associated with impairment at each of these three levels. Given the proposed developmental progression, the effects of anxiety were theorized to be most pronounced within the older cohort of adolescents. Moreover, gender was expected to affect the pattern of results. Social anxiety is most prevalent among females (LaGreca, 1998; LaGreca & Lopez, 1998), who are also thought to progress along the proposed developmental trajectory more quickly than their male counterparts. Therefore, social anxiety was expected to impact the females to a greater degree at each of the three levels. Correlation coefficients, multivariate analyses of variance, and regression analyses were used to evaluate the data. Overall, despite some discrepant findings, the results supported the hypotheses. Social anxiety was affiliated with problems in the same-sex peer group, the mixed-sex clique, and, for older adolescents, romantic relationships. As expected, social anxiety affected females the most at each level. There seems to be a maladaptive pathway that socially anxious teens are following that is markedly different than their non-anxious counterparts.
Resumo:
Diminishing crude oil and natural gas supplies, along with concern about greenhouse gas are major driving forces in the search for efficient renewable energy sources. The conversion of lignocellulosic biomass to energy and useful chemicals is a component of the solution. Ethanol is most commonly produced by enzymatic hydrolysis of complex carbohydrates to simple sugars followed by fermentation using yeast. C6Hl0O5 + H2O −Enxymes→ C6H12O6 −Yeast→ 2CH3CH2OH + 2C02 In the U.S. corn is the primary starting raw material for commercial ethanol production. However, there is insufficient corn available to meet the future demand for ethanol as a gasoline additive. Consequently a variety of processes are being developed for producing ethanol from biomass; among which is the NREL process for the production of ethanol from white hardwood. The objective of the thesis reported here was to perform a technical economic analysis of the hardwood to ethanol process. In this analysis a Greenfield plant was compared to co-locating the ethanol plant adjacent to a Kraft pulp mill. The advantage of the latter case is that facilities can be shared jointly for ethanol production and for the production of pulp. Preliminary process designs were performed for three cases; a base case size of 2205 dry tons/day of hardwood (52 million gallons of ethanol per year) as well as the two cases of half and double this size. The thermal efficiency of the NREL process was estimated to be approximately 36%; that is about 36% of the thermal energy in the wood is retained in the product ethanol and by-product electrical energy. The discounted cash flow rate of return on investment and the net present value methods of evaluating process alternatives were used to evaluate the economic feasibility of the NREL process. The minimum acceptable discounted cash flow rate of return after taxes was assumed to be 10%. In all of the process alternatives investigated, the dominant cost factors are the capital recovery charges and the cost of wood. The Greenfield NREL process is not economically viable with the cost of producing ethanol varying from $2.58 to $2.08/gallon for the half capacity and double capacity cases respectively. The co-location cases appear more promising due to reductions in capital costs. The most profitable co-location case resulted in a discounted cash flow rate of return improving from 8.5% for the half capacity case to 20.3% for the double capacity case. Due to economy of scale, the investments become more and more profitable as the size of the plant increases. This concept is limited by the amount of wood that can be delivered to the plant on a sustainable basis as well as the demand for ethanol within a reasonable distance of the plant.
Resumo:
A wide variety of spatial data collection efforts are ongoing throughout local, state and federal agencies, private firms and non-profit organizations. Each effort is established for a different purpose but organizations and individuals often collect and maintain the same or similar information. The United States federal government has undertaken many initiatives such as the National Spatial Data Infrastructure, the National Map and Geospatial One-Stop to reduce duplicative spatial data collection and promote the coordinated use, sharing, and dissemination of spatial data nationwide. A key premise in most of these initiatives is that no national government will be able to gather and maintain more than a small percentage of the geographic data that users want and desire. Thus, national initiatives depend typically on the cooperation of those already gathering spatial data and those using GIs to meet specific needs to help construct and maintain these spatial data infrastructures and geo-libraries for their nations (Onsrud 2001). Some of the impediments to widespread spatial data sharing are well known from directly asking GIs data producers why they are not currently involved in creating datasets that are of common or compatible formats, documenting their datasets in a standardized metadata format or making their datasets more readily available to others through Data Clearinghouses or geo-libraries. The research described in this thesis addresses the impediments to wide-scale spatial data sharing faced by GIs data producers and explores a new conceptual data-sharing approach, the Public Commons for Geospatial Data, that supports user-friendly metadata creation, open access licenses, archival services and documentation of parent lineage of the contributors and value- adders of digital spatial data sets.
Resumo:
A collection of poems with critical preface. The author expresses concern for responsibilities and obligations resulting from utterance and offers a means of reading poetry in light of such concerns. Lyric theory and the legacy of Language poetry with regards to the lyric are loci in a discussion of contemporary poetics. It analyzes the work of poets Tomaz Salamun and Lyn Hejinian, in relation to theorists Theodor Adorno and Maurice Merleau-Ponty, to articulate a poetics specific to the poems in the collection. The poetics is described via the literary and anthropological uses of metaphor, which are employed to unify text, writer, and reader. The phenomenology of ritual and ritual theory address these contingents to conclude the preface. The collection of poems is divided into three sections, each a distinct, interrelated collection of poetic modes.
Resumo:
This work develops the foundations of an Islamic argument for secular, liberal democracy from within the Islamic discursive tradition. First, it challenges the presentation of contemporary Islamic political thought as a unified, continuous development of the classical canon by showing the influence of the now marginalized medieval rationalists in the development of Islamic political thought. The classical rationalist concern with divine justice forced the founders of Sunni orthodoxy to state their epistemologies and their positions on ethical ontology. The orthodox positions, and their related methods of legal-juristic reasoning, are shown to be incapable of accommodating the modern Islamic positions on political representation, slavery, and just war. This leads to the second argument of the work, that the modern Islamic discourse is better understood as a reflection of the central concern with justice and its rationalist epistemology and ethical ontology we find in the writings of classical rationalists. This argument is made by examining the works of three classical rationalists, a theologian, a philosopher, and a historian. Their political positions, shaped by their rationalism and concern with justice, challenged their orthodox contemporaries, and provide substantive critiques of the classical political accommodations, methods of politico-legal reasoning, and hence, of modern Islamist political projects. The final chapter reveals how far the mainstream of Islamic political thought has deviated from the classical discourses, since the 19th century, by adopting the language and ideals of the European Enlightenment. This shift is presented as a triumph of classical rationalism over literalism, whose epistemological foundations and ontological implications have yet to be acknowledged and appreciated.
Resumo:
In the late 20th century and early 21st century, contemplative education/studies courses, concentrations, and initiatives have emerged in the academy. Although there has been significant discussion of postsecondary courses and programs that have integrated contemplative views and practices in the literature, there have been few studies of contemplative curricula and pedagogy in higher education. Additionally, there have been even fewer inquiries of the influence of contemplative education on performing arts training within conservatories and college and university departments. The aim of this qualitative study was two-fold: (1) to describe, interpret, and appraise the impact of contemplative education on the curricula of an interdisciplinary conservatory level performing arts program, MFA Contemporary Performance, at Naropa University; and (2) to disclose, compare, and analyze MFA student perceptions of the influence of contemplative education on their professional and personal development. The following questions guided this study: (1) How do faculty and students characterize contemplative education within the MFA in Theater: Contemporary Performance Program? (2) How does contemplative education impact the intended and operational curricula of courses within the MFA Contemporary Performance Program? (3) How do graduate students perceive the effects of contemplative education, offered by the MFA Contemporary Performance Program, on the development of their communication abilities, presence-in-performance, sociolinguistic perspectives, and aesthetic perspectives? Based on the research methodology of educational criticism and connoisseurship, this investigation provides a vivid description and interpretation of the intended and operational curricula of three core courses within the MFA program. These curricula were examined through five dimensions: intentional, curricular, pedagogical, structural, and evaluative. In order to shape our understanding of the contemplative and performative nature of the curricula, the significant and subtle qualities of the courses were further captured by preparation, context-building, reflective, showing, and closing conventions. Since the courses were grounded in postmodern view, they were evaluated according to Doll's criteria of richness, recursion, relations, and rigor for the evaluation of postmodern curricula. MFA first- and second-year students primarily characterized contemplative education as body/mind training for performance and personal development, sitting meditation, and cultivation of mindfulness and awareness. Student perceptions of the impact of contemplative education on the development of their communication abilities, presence-in-performance, sociolinguistic perspectives, and aesthetic perspectives, throughout the course of their two-year training, are presented in a dimensional analysis. The research reveals eight different themes that intersect the three core curricula and interviews with MFA students and faculty. These thematics include inclusivity, nowness, silence, improvisation, goodness, heart, training, and space. The beginning letter of each theme combines to form the acronym, insights. The framework of insights connects and illuminates the most potent aspects of MFA Contemporary Performance values and training.
Resumo:
The primary goal of this thesis was to determine if spaced synaptic stimulation induced the differential expression of microRNAs (miRNAs) in the Drosophila melanogaster central nervous system (CNS). Prior to attaining this goal, we needed to identify and validate a spaced stimulation paradigm that could induce the formation of new synaptic growth at a model synapse, the larval neuromuscular junction (NMJ). Both Channelrhodopsin- and high potassium-based stimulation paradigms adapted from (Ataman, et al. 2008) were tested. Once validation of these paradigms was complete, we sought to characterize the miRNA expression profile of the larval CNS by miRNA array. Following attainment of these data, we used quantitative real-time PCR (RT-qPCR) to determine if acute synaptic stimulation caused the differential expression of neuronal miRNAs. We found that upon high potassium spaced training in a wild type (Canton S) genotype, 5 miRNAs showed significant differential expression when normalized to a validated reference gene, the U1 snRNA. Moreover, absolute quantification of our RT-qPCR study implicated one miRNA: miR-958 as being significantly regulated by activity. Investigation into potential targets for miR-958 revealed it to be a potential regular of Dlar, a protein tyrosine phosphatase implicated in synapse development. This investigation provides the foundation to directly test our underlying hypothesis that, following spaced training, differential expression of miRNAs alters the translation of proteins required to induce and maintain these structural changes at the synapse.
Resumo:
The current study tested two competing models of Attention-Deficit/Hyperactivity Disorder (AD/HD), the inhibition and state regulation theories, by conducting fine-grained analyses of the Stop-Signal Task and another putative measure of behavioral inhibition, the Gordon Continuous Performance Test (G-CPT), in a large sample of children and adolescents. The inhibition theory posits that performance on these tasks reflects increased difficulties for AD/HD participants to inhibit prepotent responses. The model predicts that putative stop-signal reaction time (SSRT) group differences on the Stop-Signal Task will be primarily related to AD/HD participants requiring more warning than control participants to inhibit to the stop-signal and emphasizes the relative importance of commission errors, particularly "impulsive" type commissions, over other error types on the G-CPT. The state regulation theory, on the other hand, proposes response variability due to difficulties maintaining an optimal state of arousal as the primary deficit in AD/HD. This model predicts that SSRT differences will be more attributable to slower and/or more variable reaction time (RT) in the AD/HD group, as opposed to reflecting inhibitory deficits. State regulation assumptions also emphasize the relative importance of omission errors and "slow processing" type commissions over other error types on the G-CPT. Overall, results of Stop-Signal Task analyses were more supportive of state regulation predictions and showed that greater response variability (i.e., SDRT) in the AD/HD group was not reducible to slow mean reaction time (MRT) and that response variability made a larger contribution to increased SSRT in the AD/HD group than inhibitory processes. Examined further, ex-Gaussian analyses of Stop-Signal Task go-trial RT distributions revealed that increased variability in the AD/HD group was not due solely to a few excessively long RTs in the tail of the AD/HD distribution (i.e., tau), but rather indicated the importance of response variability throughout AD/HD group performance on the Stop-Signal Task, as well as the notable sensitivity of ex-Gaussian analyses to variability in data screening procedures. Results of G-CPT analyses indicated some support for the inhibition model, although error type analyses failed to further differentiate the theories. Finally, inclusion of primary variables of interest in exploratory factor analysis with other neurocognitive predictors of AD/HD indicated response variability as a separable construct and further supported its role in Stop-Signal Task performance. Response variability did not, however, make a unique contribution to the prediction of AD/HD symptoms beyond measures of motor processing speed in multiple deficit regression analyses. Results have implications for the interpretation of the processes reflected in widely-used variables in the AD/HD literature, as well as for the theoretical understanding of AD/HD.
Resumo:
This study examined family influences on coping and adjustment among 90 low-income Latino middle school children (46% Female; Average age = 11.38, SD = .66) and their primary caregivers (93% Female; Average age = 36.12, SD = 6.13). All participants identified as Hispanic/Latino, with 75% of families identifying as Mexican-origin Latino, 77% of parents identifying as immigrants, and 32% of children identifying immigrants. All children participating in the study were receiving free or reduced lunch, a poverty indicator. Hierarchical linear modeling analyses revealed that family reframing is related to fewer symptoms of psychopathology and that familism enhances the protective effect of family reframing, while passive appraisal is linked to worse functioning. Path analyses showed that family reframing also has indirect effects on symptoms through child primary control coping. Additional analyses identified family mobilizing support and family ethnic socialization as potential contributors to child secondary control coping. Family mobilizing support may also be helpful for single-parent families, while family spiritual support is helpful for immigrant families. Qualitative findings from an initial focus group and from the larger sample are also discussed. Results are discussed with regard to the implications of this research for preventive interventions with families in poverty. Understanding the protective links of family coping and cultural strengths to mental health outcomes of poor children can influence intervention or prevention programming and policy targeting at-risk youth and families.
Resumo:
This case study describes the analysis of the Visitor Photo Study, a study in which visitors to the Denver Museum of Nature & Science documented their visit through pictures. The origins, implementation, and findings of the Visitor Photo Study are considered within the contexts of the fields of Community-Based Research (Strand, Marullo, Cutforth, Stoecker, & Donohue, 2003b), Visual Studies (Marshall & Rossman, 2011; Pink, 2007), and Visitor Studies (Visitor Studies Association, 2012). This study considers the extent to which the principles and elements of each of these fields were present in the Visitor Photo Study, which elements were not fully realized or were missing from the study, and ways in which the Visitor Photo Study extends each of these fields. The value of this type of analysis and implications for museums, faculty, and students are also discussed.