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Examining the Role of Latitude and Differential Insolation in Asymmetrical Valley Development

Examining the Role of Latitude and Differential Insolation in Asymmetrical Valley Development

Date: August 2013
Creator: Curran, Lorna L.
Description: Valley development through erosional processes typically tends to create symmetrical valleys. Over time, water cuts through the substrate to create valleys, gorges, and canyons for which the sides are the valley are evenly sloped. However, there are anomalies to this process. Asymmetrical valleys have been well-documented even in areas of uniform substrate or little tectonic uplift. One proposed explanation for the asymmetry of these valleys is differential insolation. This may lead to different microclimates from one slope to another which alter the rate and extent of erosion. Since the differences in received insolation vary with latitude (especially in streams that flow along an east/west axis), it follows that the degree of asymmetry should also vary with latitude if differential insolation is a primary driving factor in the development of these valleys. To evaluate if insolation plays a role in the development of asymmetrical valleys, this study examines variability in asymmetry across 447 valleys in nine study areas located at different latitudes. The degree of asymmetry for each valley was measured by using 30 meter resolution digital elevation models (DEMs) to determine the slope angle of each side of the valley. Asymmetry was measured by computing a ratio of the average ...
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Hispanic Representation in the Superintendency: Perceived Competencies and Organizational Outcomes That Benefit School Districts

Hispanic Representation in the Superintendency: Perceived Competencies and Organizational Outcomes That Benefit School Districts

Date: August 2013
Creator: Medina, Fernando
Description: This study assessed 40 factors often cited in literature to determine the extent that Hispanic superintendents perceive them as influential when accessing the superintendency. Eight Hispanic superintendents in Texas participated in this qualitative study, which was based on interviews as well as written responses to a survey. This study found that the factors considered most influential to these superintendents were their ability to communicate, self-perception/self-efficacy, and level of overall preparedness. These findings contrast with previous research indicating that race or ethnicity, mentoring, and career path are most influential. The study also identified factors related to race and ethnicity that most influenced a Hispanic's ability to access the superintendency, albeit to a lesser degree. These factors were the ability to serve as a Hispanic role model to students, ability to increase Hispanic students' academic performance, and the ability to speak a second language. Moreover, through analysis of a large number of survey responses the study examined the extent to which a superintendent's race or ethnicity is significant to addressing the needs of Hispanics. To assure this question a comparative analysis of Hispanics' and non-Hispanics competencies and organizational outcome was conducted. The results indicate that superintendents, in general, regardless of race or ...
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Repetition and Difference: Parodic Narration in Kander and Ebb's "The Scottsboro Boys"

Repetition and Difference: Parodic Narration in Kander and Ebb's "The Scottsboro Boys"

Date: August 2013
Creator: Wolski, Kristin Anne
Description: The American musical team John Kander and Fred Ebb created many celebrated works, yet musicologists have carried out little research on those works. This study examines the role of music in the parodic narration of Kander and Ebb's final collaboration, The Scottsboro Boys. Kander and Ebb use minstrelsy to tell the story of the historic Scottsboro Boys trials with actors portraying the Scottsboro Boys as minstrels; at the same time, they employ a number of devices to subvert minstrelsy stereotypes and thereby comment on racism. Drawing on African American literary theory, sociolinguistics, and Bakhtin's dialogism, this study illuminates how Signifyin(g), a rhetorical tradition used to encode messages in some African American communities, is the primary way the actors playing the Scottsboro Boys subvert through minstrelsy. This study not only contributes to the discussion of Signifyin(g) in African American musicals and theatre as a tool of subversion, but also provides an example of non-African American creators—Kander and Ebb—using Signifyin(g) devices. They use these in the music and the book; in particular, Kander and Ebb do some Signifyin(g) on Stephen Foster's plantation melodies.
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Metabolic Engineering in Plants to Control Source/sink Relationship and Biomass Distribution

Metabolic Engineering in Plants to Control Source/sink Relationship and Biomass Distribution

Date: August 2013
Creator: Lahiri, Ipsita
Description: Traditional methods like pruning and breeding have historically been used in crop production to divert photoassimilates to harvested organs, but molecular biotechnology is now poised to significantly increase yield by manipulating resource partitioning. It was hypothesized that metabolic engineering in targeted sink tissues can favor resource partitioning to increase harvest. Raffinose Family Oligosaccharides (RFOs) are naturally occurring oligosaccharides that are widespread in plants and are responsible for carbon transport, storage and protection against cold and drought stress. Transgenic plants (GRS47, GRS63) were engineered to generate and transport more RFOs through the phloem than the wild type plants. The transgenic lines produced more RFOs and the RFOs were also detected in their phloem exudates. But the 14CO2 labeling and subsequent thin layer chromatography analysis showed that the RFOs were most likely sequestered in an inactive pool and accumulate over time. Crossing GRS47 and GRS63 lines with MIPS1 plants (that produces more myo-inositol, a substrate in the RFO biosynthetic pathway) did not significantly increase the RFOs in the crossed lines. For future manipulation of RFO degradation in sink organs, the roles of the endogenous α-galactosidases were analyzed. The alkaline α-galactosidases (AtSIP1 and AtSIP2 in Arabidopsis) are most likely responsible for digesting RFOs ...
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The Role of Attachment in Perceptions of Interparental Conflict and Behavior Problems in Middle Childhood

The Role of Attachment in Perceptions of Interparental Conflict and Behavior Problems in Middle Childhood

Date: August 2013
Creator: Cusimano, Angela Marie
Description: The current study investigated the association of interparental conflict, parent-child attachment, and children's behavior problems in middle childhood. Although the effects of interparental conflict have been studied extensively, there has been little research done in the developmental period of middle childhood. This study examined the potential mediating role of the attachment relationship between parents and children in a community sample consisting of 86 two-parent families with at least one child between the ages of 8-11. Path modeling procedures indicated that attachment security serves as a mediator between interparental conflict and child behavior problems based on child reports. In particular, child-reported attachment security to the mother significantly mediated the association between children's perceptions of threat from interparental conflict and child-reported internalizing and inattentive/hyperactive symptoms. Child-reported attachment security to the father was not a significant mediator and mediation was not supported in parent-report models. The current findings have implications for families experiencing conflict and speak to the importance of attachment in the parent-child relationship when explaining the association between instances of interparental conflict and child behavioral outcomes. In particular, parents who engage in conflict can prevent the damaging effects of that conflict by making the conflict less overt, explaining to children the ...
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An Examination of the Similarities and Differences Between Transformational and Authentic Leadership and Their Relationship to Followers' Outcomes

An Examination of the Similarities and Differences Between Transformational and Authentic Leadership and Their Relationship to Followers' Outcomes

Date: August 2013
Creator: McKee, Victoria
Description: To date there is no comprehensive understanding of what leadership is, nor is there an agreement among different theorists on what a good or effective leader should be. The purpose of this dissertation is to examine the theoretical and empirical similarities and differences of two styles of leadership – transformational and authentic leadership. Follower outcomes, as well as, the effects of trust and psychological capital within these paradigms are of particular interest. Although theoretical differences are proposed for the leadership style, the extent of overlap suggests the need to more closely examine each theory. Pilot studies were created to validate original scenarios created for the study as well as to examine the validity and reliability of new measurement instruments. The dissertation is designed to determine whether the relationships between authentic leadership and a variety of follower outcomes including performance, affective commitment, satisfaction, trust, and organizational citizenship behavior are similar to those between transformational leadership and these outcomes. In addition, variables more unique to authentic leadership research including psychological capital and follower well-being were examined within both paradigms to determine whether their relationships are similar to each type of leadership style. An experimental study using Qualtrics was used to collect the ...
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Mist and Microstructure Characterization in End Milling Aisi 1018 Steel Using Microlubrication

Mist and Microstructure Characterization in End Milling Aisi 1018 Steel Using Microlubrication

Date: August 2013
Creator: Shaikh, Vasim
Description: Flood cooling is primarily used to cool and lubricate the cutting tool and workpiece interface during a machining process. But the adverse health effects caused by the use of flood coolants are drawing manufacturers' attention to develop methods for controlling occupational exposure to cutting fluids. Microlubrication serves as an alternative to flood cooling by reducing the volume of cutting fluid used in the machining process. Microlubrication minimizes the exposure of metal working fluids to the machining operators leading to an economical, safer and healthy workplace environment. In this dissertation, a vegetable based lubricant is used to conduct mist, microstructure and wear analyses during end milling AISI 1018 steel using microlubrication. A two-flute solid carbide cutting tool was used with varying cutting speed and feed rate levels with a constant depth of cut. A full factorial experiment with Multivariate Analysis of Variance (MANOVA) was conducted and regression models were generated along with parameter optimization for the flank wear, aerosol mass concentration and the aerosol particle size. MANOVA indicated that the speed and feed variables main effects are significant, but the interaction of (speed*feed) was not significant at 95% confidence level. The model was able to predict 69.44%, 68.06% and 42.90% of ...
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Quantifying Forest Vertical Structure to Determine Bird Habitat Quality in the Greenbelt Corridor, Denton, Tx

Quantifying Forest Vertical Structure to Determine Bird Habitat Quality in the Greenbelt Corridor, Denton, Tx

Date: August 2013
Creator: Matsubayashi, Shiho
Description: This study presents the integration of light detection and range (LiDAR) and hyperspectral remote sensing to create a three-dimensional bird habitat map in the Greenbelt Corridor of the Elm Fork of the Trinity River. This map permits to examine the relationship between forest stand structure, landscape heterogeneity, and bird community composition. A biannual bird census was conducted at this site during the breeding seasons of 2009 and 2010. Census data combined with the three-dimensional map suggest that local breeding bird abundance, community structure, and spatial distribution patterns are highly influenced by vertical heterogeneity of vegetation surface. For local breeding birds, vertical heterogeneity of canopy surface within stands, connectivity to adjacent forest patches, largest forest patch index, and habitat (vegetation) types proved to be the most influential factors to determine bird community assemblages. Results also highlight the critical role of secondary forests to increase functional connectivity of forest patches. Overall, three-dimensional habitat descriptions derived from integrated LiDAR and hyperspectral data serve as a powerful bird conservation tool that shows how the distribution of bird species relates to forest composition and structure at various scales.
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Altruism and Depression: Exploring This Relationship and the Mechanisms Behind It

Altruism and Depression: Exploring This Relationship and the Mechanisms Behind It

Date: August 2013
Creator: Wright, Brittney, C.
Description: The impact of environmental influences on depression has been well established by research. In particular, it is known that receiving/perceiving adequate social support has a protective influence on depression. Less is known about the protective benefits of providing support to others, namely in the form of altruistic, empathetic, or prosocial behavior. While research has shown that having altruistic attitudes and engaging in altruistic behaviors has a positive impact on physical health and mental well-being, studies on the association between altruistic attitudes and/or behavior and depression are limited. The present study examined the relationship between altruism and depression, and hypotheses were tested that allow for explanation of why altruism may protect against depression. A sample of 303 participants was recruited from the University of North Texas and the surrounding community. Participants completed an online survey that examined their altruistic activities, details regarding these activities, their prosocial attitudes, and their current level of depression. Results did not support that level of involvement in altruistic activities is directly related to depression severity. However, outcomes from involvement in altruistic activities, including sense of overburden from participating in altruistic activities, level of social interaction with other helpers and those helped during altruistic activities, and sense ...
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A Survey of the Solo and Chamber Works for Trumpet, Horn, Trombone, Euphonium and Tuba By the Hungarian Composer Frigyes Hidas

A Survey of the Solo and Chamber Works for Trumpet, Horn, Trombone, Euphonium and Tuba By the Hungarian Composer Frigyes Hidas

Date: August 2013
Creator: Gill, Jonathan B.
Description: Hidas composed more than 135 compositions. Of these 135 compositions 67 feature the trumpet, horn, trombone, euphonium, and tuba in a solo setting, a homogenous chamber setting, or a heterogeneous chamber setting. The first section of this project presents the significance of the topic, state of research, and methodology. Chapter one provides a narrative detailing the collaboration of Hidas with Gusztáv Höna and László Szabó, Sr. Chapter two provides a brief description of characteristics found in Hidas' compositions. Appendix A and B provides a survey of the 67 works for brass instruments that Hidas composed. Included in this survey is information pertaining to the title, editor, publisher and date of publication, total measures, duration, ranges, degree of difficulty, clefs, special effects/techniques, instrumentation, dedications, analytical information, general comments, recordings, and rental details.
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