Experiments and direct numerical simulations have been performed to examine the effects of initial conditions on the dynamics of a Rayleigh-Taylor mixing layer. Experiments were performed on a water channel facility to quantify the interfacial and velocity perturbations initially present at the two-fluid interface in a small Atwood number mixing layer. The measurements have been parameterized for implementation in numerical simulations of the experiment, and two- and three-dimensional direct numerical simulations (DNS) of the experiment have been performed. It is shown that simulations implemented with initial velocity perturbations are required to match experimentally-measured statistics. Data acquired from both the experiment and numerical simulations are used to elucidate the role of initial conditions on the evolution of integral-scale, turbulence, and mixing statistics. Early-time turbulence and mixing statistics will be shown to be strongly dependent upon the early-time transition of the initial perturbation from a weakly- to a strongly-nonlinear flow.

The research described in this dissertation consists of four major areas: (1) sequence analysis of protamine 2 from Muroid rodents to identify potential zinc-binding domain(s) of protamine 2; (2) structural studies of the protamine 2-zinc complex from Syrian Gold hamster sperm and spermatids to elucidate the role of zinc during spermiogenesis; (3) structural studies of an unique protamine 2-zinc complex from chinchilla sperm; and (4) Nuclear Magnetic Resonance (NMR) studies of soluble complexes of hairpin oligonucleotides with synthetic arginine-rich peptides or protamine 1 isolated from bull sperm. First, zinc was quantitated in spermatids and sperm by Proton-Induced X-ray Emission (PIXE) to determine whether zinc is present in the early stages of spermiogenesis. The PIXE results revealed the zinc content varies proportionately with the amount of protamine 2 in both spermatid and sperm nuclei. An exception was chinchilla sperm containing twice the amount of protamine 2 than zinc. Further analyses by PIXE and X-ray Absorption Spectroscopy (XAS) of zinc bound to protamines isolated from hamster sperm confirmed the majority of the zinc is bound to protamine and identified the zinc ligands of protamine 2 in hamster spermatids and sperm in vivo. These studies established that zinc is bound to the protamine …

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This dissertation documents an object oriented framework which can be used to solve any linear wave equation. The linear wave equations are expressed in the differential forms language. This differential forms expression allows a strict discrete interpretation of the system. The framework is implemented using the Galerkin Finite Element Method to define the discrete differential forms and operators. Finite element basis functions including standard scalar Nodal and vector Nedelec basis functions are used to implement the discrete differential forms resulting in a mixed finite element system. Discretizations of scalar and vector wave equations in the time and frequency domains will be demonstrated in both differential forms and vector calculi. This framework conserves energy, maintains physical continuity, is valid on unstructured grids, conditionally stable and second order accurate. Examples including linear electrodynamics, acoustics, elasticity and magnetohydrodynamics are demonstrated.

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The remarkable uniformity of Type Ia supernovae has allowed astronomers to use them as distance indicators to measure the properties and expansion history of the Universe. However, Type Ia supernovae exhibit intrinsic variation in both their spectra and observed brightness. The brightness variations have been approximately corrected by various methods, but there remain intrinsic variations that limit the statistical power of current and future observations of distant supernovae for cosmological purposes. There may be systematic effects in this residual variation that evolve with redshift and thus limit the cosmological power of SN Ia luminosity-distance experiments. To reduce these systematic uncertainties, we need a deeper understanding of the observed variations in Type Ia supernovae. Toward this end, the Nearby Supernova Factory has been designed to discover hundreds of Type Ia supernovae in a systematic and automated fashion and study them in detail. This project will observe these supernovae spectrophotometrically to provide the homogeneous high-quality data set necessary to improve the understanding and calibration of these vital cosmological yardsticks. From 1998 to 2003, in collaboration with the Near-Earth Asteroid Tracking group at the Jet Propulsion Laboratory, a systematic and automated searching program was conceived and executed using the computing facilities at Lawrence …

The Sudbury Neutrino Observatory (SNO) is a large-volume heavy water Cerenkov detector designed to resolve the solar neutrino problem. SNO observes charged-current interactions with electron neutrinos, neutral-current interactions with all active neutrinos, and elastic-scattering interactions primarily with electron neutrinos with some sensitivity to other flavors. This dissertation presents an analysis of the solar neutrino flux observed in SNO in the second phase of operation, while {approx}2 tonnes of salt (NaCl) were dissolved in the heavy water. The dataset here represents 391 live days of data. Only the events above a visible energy threshold of 5.5 MeV and inside a fiducial volume within 550 cm of the center of the detector are studied. The neutrino flux observed via the charged-current interaction is [1.71 {+-} 0.065(stat.){+-}{sub 0.068}{sup 0.065}(sys.){+-}0.02(theor.)] x 10{sup 6}cm{sup -2}s{sup -1}, via the elastic-scattering interaction is [2.21{+-}0.22(stat.){+-}{sub 0.12}{sup 0.11}(sys.){+-}0.01(theor.)] x 10{sup 6}cm{sup -2}s{sup -1}, and via the neutral-current interaction is [5.05{+-}0.23(stat.){+-}{sub 0.37}{sup 0.31}(sys.){+-}0.06(theor.)] x 10{sup 6}cm{sup -2}s{sup -1}. The electron-only flux seen via the charged-current interaction is more than 7{sigma} below the total active flux seen via the neutral-current interaction, providing strong evidence that neutrinos are undergoing flavor transformation as they travel from the core of the Sun to the …

A series of in situ toughened, Al, B and C containing, silicon carbide ceramics (ABC-SiC) has been examined with Al contents varying from 3 to 7 wt%. With increasing Al additions, the grain morphology in the as-processed microstructures varied from elongated to bimodal to equiaxed, with a change in the nature of the grain-boundary film from amorphous to partially crystalline to fully crystalline. Fracture toughness and cyclic fatigue tests on these microstructures revealed that although the 7 wt.% Al containing material (7ABC) was extremely brittle, the 3 and particularly 5 wt.% Al materials (3ABC and 5ABC, respectively) displayed excellent crack-growth resistance at both ambient (25 C) and elevated (1300 C) temperatures. Indeed, no evidence of creep damage, in the form of grain-boundary cavitation, was seen at temperatures at 1300 C or below. The enhanced toughness of the higher Al-containing materials was associated with extensive crack bridging from both interlocking grains (in 3ABC) and uncracked ligaments (in 5ABC); in contrast, the 7ABC SiC showed no such bridging, concomitant with a marked reduction in the volume fraction of elongated grains. Mechanistically, cyclic fatigue-crack growth in 3ABC and 5ABC SiC involved the progressive degradation of such bridging ligaments in the crack wake, with …

This project consists of an original composition, Voci Lontani, and a critical essay about the composition. In this piece, the idea of musical simultaneity is explored. Therefore, the piece focuses on the idea of contrast: between measured rhythms and indeterminate rhythms, between tonality and atonality, and between musics in separate tempos. In order to explore the significance of musical simultaneity, four important compositional concepts-the simultaneous juxtaposition of different musics, polyrhythmic structure, controlled indeterminacy, and quotation-are discussed. Also, several examples of twentieth-century music that use these concepts are analyzed in the essay.

Educational researchers, practitioners, and policy makers have long expressed their concern that gender disparity of academic performance and participation in science and mathematics education continues to increase with educational progress of students through the pipeline. Educational and occupational aspirations, high school experience, external support from family members and significant others appear to be influential factors that develop strong self-concept among female students who aspire to study science and mathematics. Using a national sample of aspirants in science, mathematics, and engineering majors in public community colleges, that participated in the 1996 Cooperative Institutional Research Program American Freshman Survey, this study investigated the influences of students' pre-college experiences on their college choice, aspirations, and self-concept by examining three theoretical structural models. In addition, gender differences were tested by using multiple group analysis. The findings from the multiple group analysis revealed that there was no statistically significant gender difference in predicting college choice, aspirations, and self-concept. The results from the descriptive analysis indicated that the female students were already underrepresented in science, mathematics, and engineering majors. Taken together, the findings challenge researchers, practitioners, and policy makers to examine why the persistent fall off, and how can community colleges support and retain these students …

The purpose of this paper is to analyze and identify the major factors that determine the success or failure of mega-sports events. The report begins with a discussion of why localities are willing to invest large sums of public monies in infrastructure and services to host these events. This is followed by a review of the methods used to assess the economic, fiscal, and social impacts of hosting large sporting events. It is observed that comprehensive analyses of the impacts of these events are not undertaken. Finally, the major factors that affect the success of these events are discussed along with suggestions for improving studies evaluating success or failure.

This dissertation research explored the capabilities of neuronal networks grown on substrate integrated microelectrode arrays in vitro to be applied to toxicological research and lipid signaling. Chapter 1 details the effects of chlorine on neuronal network spontaneous electrical activity and pharmacological sensitivity. This study demonstrates that neuronal networks can maintain baseline spontaneous activity, and respond normally to pharmacological manipulations in the present of three times the chlorine present in drinking water. The findings suggest that neuronal networks may be used as biological sensors to monitor the quality of water and the presence of novel toxicants that cannot be detected by conventional sensors. Chapter 2 details the neuromodulatory effects of N-acylethanolamides (NAEs) on the spontaneous electrical activity of neuronal networks. NAEs are a group of lipids that can mimic the effects of marijuana and can be derived from a variety of plant sources including soy lecithin. The most prominent NAEs in soy lecithin, palmitoylethanolamide (PEA) and linoleoylethanolamide (LEA), were tested individually and were found to significantly inhibit neuronal spiking and bursting activity. These effects were potentiated by a mixture of NAEs as found in a HPLC enriched fraction from soy lecithin. Cannabinoid receptor-1 (CB1-R) antagonists and other cannabinoid pathway modulators indicated …

Glutathione syntethase (GS) is an enzyme that belongs to the ATP-grasp superfamily and catalyzes the second step in the biosynthesis of glutathione. GS has been purified and sequenced from a variety of biological sources; still, its exact mechanism is not fully understood. Four highly conserved residues were identified in the binding site of human GS. Additionally, the G-loop residues that close the active site during catalysis were found to be conserved. Since these residues are important for catalysis, their function was studied computationally by site-directed mutagenesis. Starting from the reported crystal structure of human GS, different conformations for the wild type and mutants were obtained using molecular dynamics technique. The key interactions between residues and ligands were detected and found to be essential for enzyme activity.

The thrust of this paper was two-fold, 1) to confirm a 2-factor model of narcissism in women, and 2) to examine the relationship between narcissistic traits in mothers and several variables associated with parenting efficacy. Participants included 193 mother-child dyads. A 2-factor model of narcissism was confirmed in the present sample of mothers, suggesting that narcissistic traits in women may be manifested in distinct Overt and Covert forms. Contrary to expectations, Covert Narcissistic traits in mothers did not significantly correlate with observed parenting behaviors on the PCIA, including Positive Personal Comments (PPC) towards children, Negative Personal Comments (NPC), and Parental Nurturance. However, children's self-reported maternal rejection on the C-PARQ correlated positively with Covert Narcissistic traits in mothers, as did mother's self-reported dysfunctional parenting attitudes on the AAPI-2. Narcissistic traits in mothers correlated most strongly with risk of child physical abuse on the CAPI (r = .70). Results are also presented for the Overt Narcissism factor, which proved to be less stable as a factor. Overall, results emphasize the need for a more comprehensive understanding of narcissism for women, given its potential Implications for children's healthy development and parenting interventions.

Non-profits are increasing in size and scope to meet social needs that are unmet by the government. Declining financial support, government regulations, and increasing competition force non-profits to become more professional and efficient. Non-profits increasingly engage in commercial activities, joint ventures with for-profits, and employ business techniques such as business planning and marketing. An extensive body of research examines issues related to non-profit performance that supplies a framework for business planning. Business planning may help non-profits to sustain competitive advantages and long-term financial stability. This paper examines the challenges of writing a business plan for non-profits concluding with a sample business plan that takes into consideration advantages, risks, and limitations of non-profits.

Informed by the methodology utilized in Peter Williams's Houses of God: Region, Religion, and Architecture in the United States (1997), the thesis examines Mark Lemmon's Gothic Revival design for the Highland Park Presbyterian Church (1941) with special attention to the denomination and social class of the congregation and the architectural style of the church. Beginning with the notion that Lemmon's church is more complex than an expression of the Southern cultural region defined by Williams, the thesis presents the opportunity to examine the church in the context of the unique cultural region of the city of Dallas. Church archival material supports the argument that the congregation deliberately sought to identify with both the forms and ideology of the late nineteenth-century Gothic Revival in the northeastern United States, a result of the influence of Dallas's cultural region.

The human opportunistic pathogen, Pseudomonas aeruginosa PAO1, has been shown to kill the nematode Caenorhabditis elegans. C. elegans has been a valuable model for the study of bacterial pathogenesis, and has reinforced the notion that common virulence and host defense mechanisms exist. Recently, the pyrimidine pathway was shown to regulate virulence levels. Therefore, mutations in the pyrimidine pathway of PAO1 showed decrease virulence in the nematode. When starving the nematode, bacterial resistance was also shown to increase. It was hypothesized that starvation induced the DAF pathway, which regulates the transcription of genes involved with the antibacterial defense mechanism. Further research will be conducted to test this theory by performing RNAi experiments for the genes functioning in the antibacterial defense mechanism.

This study investigated the perceptions of influential relationships between Texas public university presidents, university system chancellors, and state legislators. The study's purpose was to examine Texas public universities engagement in lobbying type behaviors and whether public policy is affected through interaction and communication with legislative leaders. Moreover, of importance for this study was to identifying if Texas public universities actively work to influence the Texas legislature and if lobbying behavior exists whether or not that behavior influences public policy formation within the Texas legislative process. Lastly, this study focused on perceptions dealing with the Texas statute prohibiting state governmental agencies, including public universities and university systems, from influencing legislation through use of state funds. The study was conducted in the winter of 2003 and had 29 president / chancellor respondents and 88 legislator respondents. Three survey instruments were developed by the researcher to determine Texas public university president, system chancellor, and state legislator perceptions and attitudes concerning lobbying type activities, influence, and state statute compliance. Data reported consist of percentages, t-Test of significance, and Cohen's d effect size measure. Results from the study show agreement between the groups in areas of activities utilized to influence the legislative process and actual …

There were two major goals of this study - to examine validity of scores for the Boholst Life Position Scale and to examine potential associations between life positions and affective traits. Two hundred seventy-seven students enrolled in undergraduate psychology classes at a large university volunteered for the study. Concurrent validity of scores for the life position scale was supported based on two compared instruments. Pearson product-moment correlations for the comparisons were -.765 and .617, both statistically significant at the p < .001 level. Factor analysis demonstrated that the scale could accurately be conceptualized as consisting of two factors - an "I" factor and a "You" factor. MANOVA, ANOVA, multiple linear regression, and canonical correlation analysis were used to examine associations between life positions and the affective traits of angry, sad, glad, social anxiety, loneliness, and satisfaction with life. Subjects were catagorized into four groups representing their life position: "I'm OK, you're OK," "I'm OK, you're not OK," "I'm not OK, you're OK," and "I'm not OK, you're not OK." A MANOVA employing life position as the independent variable with four levels and the six affective traits as the dependent variables demonstrated statistical significance (p < .001 level) and h2 was …

The purpose of this study was to evaluate the effects of a training package consisting of response restriction and the reinforcement of self-evaluation on letter reversal errors. Participants were 3 typically developing boys between the age of 5 and 7. The results indicated that the training package was successful in correcting reversals in the absence of a model during training and on application tests. These improvements maintained during subsequent follow-up sessions and generalized across trainers. Fading was not always necessary in correcting reversals, but was effective in correcting reversals that persisted during the overlay training procedures. The advantages to implementing a systematic intervention for reducing letter reversal errors in the classroom, as well as directions for future research, are discussed.

The purpose was to examine the effect of chronic alcohol abuse on the androgen receptor content (AR) in skeletal muscle, and to determine if this effect was influenced by resistance training. Thirty-four male rats (456 ± 1 g; mean ± SE) were divided into 4 groups: Sham exercise-Ethanol, Sham exercise-Normal diet, Exercise-Ethanol, and Exercise-Normal diet. Both Exercise groups underwent a 6-week "squat" resistance training protocol and both Ethanol groups received an alcohol-rich diet throughout the 6-week period. Western blot analysis showed no effect of alcohol or resistance training on the AR of the extensor digitorum longus. For the rectus femoris, alcohol caused a decline in the AR (p=0.01). This reduction was not attenuated by resistance training. The AR of the soleus was not affected by chronic alcohol abuse alone; however, the resistance training induced increase in the AR was prevented by chronic alcohol abuse (p=0.03).

This study examined how technology-mediated distance education is used in special education courses in teacher preparation programs. The data are based on a 30-item survey administered to members of the Teacher Education Division of the Council for Exceptional Children, who identified themselves as serving in an instructional capacity within institutions of higher education. Technology-mediated instruction was characterized in terms course delivery methods and program attributes. An analysis of instructional design processes revealed that most instructors are largely autonomous and do not rely on a team-based approach. Most make use of course-design and management software. Training is linked to course strategy and evaluation, while experience is associated with implementation. Respondents emphasized communication and student feedback. While both users and non-users of distance education technology foresaw the increased use for course delivery in the future, a notable percentage (13%) of current users indicated a desire to discontinue use.

It is said that there is a "productivity paradox" existing in the workplace meaning there are no net benefits from information technology spending. This paper attempts to answer the question as to whether there is a need to account for a change in the growth rate of productivity after the Internet was opened up to commercial use. Using the Chow Test for structural change I concluded that there was indeed a positive change in the growth rate of productivity beginning in the early 1990s that can be associated with increasing Internet usage.

I examine the passage of alternative teacher certification policies in the states between 1975 and 2000 using event history analysis and supplementing the event history analysis with an ordinary least squares regression analysis of the strength of the alternative teacher certification policies. In order to test both teachers unions political strength external to state legislatures and teachers unions political strength internal to state legislatures, I use two variables to measure teachers union political strength. One variable measures the percentage of teachers in a state who work under union-negotiated contracts. The other variable measures the percentage of legislators in a state who list their non-legislative occupation as K-12 education. Control variables include teacher shortages, per pupil spending, legislative professionalism, divided government, democratic governor, percentage of minority students, change in percentage of minority students, an electoral threat index, and a time counter. Although the event history model results were inconclusive with respect to the teachers union political strength variables, the policy strength model results reveal that states with large percentages of teachers who work under union-negotiated contracts are more likely than other states to pass weak alternative teacher certification policies. This result supports the notion that teachers unions operate in the education …