Previous research implementing stratification on the propensity score has generally relied on using five strata, based on prior theoretical groundwork and minimal empirical evidence as to the suitability of quintiles to adequately reduce bias in all cases and across all sample sizes. This study investigates bias reduction across varying number of strata and sample sizes via a large-scale simulation to determine the adequacy of quintiles for bias reduction under all conditions. Sample sizes ranged from 100 to 50,000 and strata from 3 to 20. Both the percentage of bias reduction and the standardized selection bias were examined. The results show that while the particular covariates in the simulation met certain criteria with five strata that greater bias reduction could be achieved by increasing the number of strata, especially with larger sample sizes. Simulation code written in R is included.

How adolescents spend their time is a crucial predictor of their engagement in delinquency. Activities with peers away from direct supervision of adults are of concern as more opportunities and motivation to use marijuana exist in such situations. However, adolescents may vary in their propensity to use marijuana when faced the opportunity. Especially adolescents living with a single parent may have a higher propensity compared to those from two-parent households to use marijuana due to reduced parental monitoring and increased peer attachment. This thesis investigates the moderating effects of family structure on the routine leisure activities and adolescent marijuana use relationship, using data from Monitoring the Future Study 2007, 12th Grade Survey. The results provide partial support for the moderating effects.

After providing an historical overview of the French spelling system and orthographic variation, this study analyzes selected internal (i.e., linguistic) factors and one external (i.e., social) factor that can influence the use of diacritics in online French-language chat sessions. From a corpus of synchronous computer-mediated communication, 3,855 tokens of graphemes capable of bearing diacritics were coded with the following scheme: Letter, Diacritic, Grapheme (i.e., Letter and Diacritic combined), Date of Participation, and Age Group of Participant. A multivariate (VARBRUL) analysis determined that Grapheme exerts the most influence on variation.

Multi-walled carbon nanotube aggregates can be suspended in the aqueous phase by natural organic matter. These aggregates are ingested by filter feeding zooplankton. Ingested aggregates result in decreased growth and decreased reproduction. These effects may be caused by reduction in energy input from normal feeding behavior. pH alters natural organic matter structure through changes in electrostatic repulsion. Altered natural organic matter structure changes multi-walled carbon nanotube aggregate size. This size variation with variation in pH is significant, but not large enough a change in size to alter toxicity, as the aggregate size range remains well within the particle size selection of the organisms.

Childhood exposure to familial violence increases risk for adult pathology, namely posttraumatic stress disorder (PTSD) and depression. Primary PTSD symptoms of hyperarousal and avoidance are implicated in overgeneral memory (OGM) theory in prior research. Individuals with trauma history tend to report OGMs, or non-specific autobiographical memories, perhaps to avoid unpleasant arousal elicited by recalling specific events. OGM, PTSD, depression, and arousal were assessed in adults with and without familial violence history. Arousal was measured via galvanic skin response (GSR) during an autobiographical memory task (AMT), requiring memory recall in response to emotionally-valenced cue words. Familial violence history was linked to higher incidence of PTSD symptoms. Childhood psychological violence was predictive of adult PTSD. Rates of depression, OGM, and arousal did not significantly vary by violence history. Significant gender differences were found relating to type of violence exposure and adult functioning. Research limitations, clinical implications, and future research suggestions are discussed.

This publication of the Dallas-Fort Worth Section of the American Chemical Society includes information about research, prominent scientist, organizational business, and various other stories of interest to the community.

The measurement of happiness has received increasing attention in behavior analytic literature. Happiness in individuals with developmental disabilities has been assessed by 1) counting a specific behavior, or 2) sampling constellations of behaviors. The purpose of this study was to examine the two approaches while observing nine child and teacher dyads at an autism treatment center. Results showed that, overall, a constellation of behaviors can yield similar patterns when compared to a specific behavior count. However, the affect of one person did not predict the affect of the other and similar instructional conditions did not predict affect either. The implications of these results and future directions are discussed.

This dissertation describes a compositional model rooted in cross-influential methodology between complementary musical compositions that share generative source material. In their simultaneous construction, two composition pairs presented challenges that influenced and mediated the other's development with respect to timbre, transposition, pitch material, effects processing, and form. A working prototype first provides a model that is later developed. The first work Thema is for piano alone, and the companion piece Am3ht is for piano and live computer processing via the graphical programming environment Max/MSP. Compositional processes used in the prototype solidify the cross-influential model, demanding flexibility and a dialectic approach. Ideas set forth in the prototype are then explored through a second pair of compositions rooted in cross-influential methodology. The first work Lusmore is scored for solo contrabass and Max/MSP. The second composition Knockgrafton is scored for string orchestra. The flexibility of the cross-influential model is revealed more fully through a discussion of each work's musical development. The utility of the cross-influential compositional model is discussed, particularly within higher academia.

The purpose of this study was twofold. First, the study compared fashion personality characteristics and shopping behaviors of African-American and Caucasian-American college students. Secondly, this study examined characteristics of leadership in general, and fashion leadership specifically, on fashion personality characteristics. The fashion personality characteristics studied included fashion leadership, fashion involvement, shopping enjoyment, and fashion consciousness. The participants consisted of 268 African Americans and 239 Caucasian Americans from two universities in the United States. Ethnicity was found to be an influence on fashion personality characteristics and shopping behaviors in this study. African Americans in the sample were found to have higher levels of fashion personality characteristics and shopping behaviors than Caucasian Americans. Fashion leadership was found to be positively related to general leadership, fashion involvement, shopping enjoyment and fashion consciousness. General leadership was found to be positively related to fashion involvement, shopping enjoyment, fashion consciousness, academic classification level. However, there was no significant difference found between general leadership and age.

The major topics discussed are the phosphorescence sensitization in the lanthanides via energy transfer and in the organics by heavy atom effects. The f-f transitions in lanthanides are parity forbidden and have weak molar extinction coefficients. Upon complexation with the ligand, ttrpy (4'-p-Tolyl-[2,2':6',2"]-terpyridine) the absorption takes place through the ligand and the excitation is transferred to the lanthanides, which in turn emit. This process is known as "sensitized luminescence." Bright red emission from europium and bright green emission from terbium complexes were observed. There is ongoing work on the making of OLEDs with neutral complexes of lanthanide hexafluoroacetyl acetonate/ttrpy, studied in this dissertation. Attempts to observe analogous energy transfer from the inorganic donor complexes of Au(I) thiocyanates were unsuccessful due to poor overlap of the emissions of these systems with the absorptions of Eu(III) and Tb(III). Photophysics of silver-aromatic complexes deals with the enhancement of phosphorescence in the aromatics. The heavy atom effect of the silver is responsible for this enhancement in phosphorescence. Aromatics such as naphthalene, perylene, anthracene and pyrene were involved in this study. Stern Volmer plots were studied by performing the quenching studies. The quenchers employed were both heavy metals such as silver and thallium and lighter …

This thesis addresses some theoretical issues generated by the results of recent analysis of EEG time series proving the brain dynamics are driven by abrupt changes making them depart from the ordinary Poisson condition. These changes are renewal, unpredictable and non-ergodic. We refer to them as crucial events. How is it possible that this form of randomness be compatible with the generation of waves, for instance alpha waves, whose observation seems to suggest the opposite view the brain is characterized by surprisingly extended coherence? To shed light into this apparently irretrievable contradiction we propose a model based on a generalized form of Langevin equation under the influence of a periodic stimulus. We assume that there exist two different forms of time, a subjective form compatible with Poisson statistical physical and an objective form that is accessible to experimental observation. The transition from the former to the latter form is determined by the brain dynamics interpreted as emerging from the cooperative interaction among many units that, in the absence of cooperation would generate Poisson fluctuations. We call natural time the brain internal time and we make the assumption that in the natural time representation the time evolution of the EEG variable …

Science fiction has long promised the digitalization of books. Characters in films and television routinely check their palm-sized (or smaller) electronic displays for fast-scrolling information. However, this very technology, increasingly prevalent in today's world, has not been embraced universally. While the convenience of pocket-sized information pieces has the techno-savvy entranced, the general public still greets the advent of the e-book with a curious reluctance. This lack of enthusiasm seems strange in the face of the many advantages offered by the new medium - vastly superior storage capacity, searchability, portability, lower cost, and instantaneous access. This dissertation addresses the need for research examining the reading comprehension and the role emotional response plays in the perceived performance on e-document formats as compared to traditional paper format. This study compares the relative reading comprehension on three formats (Kindle, iTouch, and paper) and examines the relationship of subject's emotional response and relative technology exposure as factors that affect how the subject perceives they have performed on those formats. This study demonstrates that, for basic reading comprehension, the medium does not matter. Furthermore, it shows that, the more uncomfortable a person is with technology and expertise in the requested task (in this case, reading), the …

This study examined the professional networking of North and West Texas public school superintendents. It looked at how these superintendents professionally network, use professional organizations in networking, and how they extend opportunities beyond the organizations to gain knowledge and information about their demanding and stressful responsibilities. Lastly, it looked at superintendents in the field on whom others rely for knowledge and understanding. Surveys were mailed out to 443 North and West Texas public schools. Only the superintendents from those districts were asked to complete the survey. This limitation was desired to restrict the population to only the superintendents of schools, thus focusing the study on the professional networking of only superintendents. Three hundred sixty (360) superintendents responded to the survey, a return rate of 81.3%. This research concluded that superintendents professionally network by communicating through monthly meetings, organizational conferences or meetings, or email. Their networks are facilitated through communication, contacts, location, longevity, and organizational associations. These organizations provide the superintendent's primary network contact. The number of contacts in a network is usually a small group of 5 to 9 professionals who are known from longevity in the profession, prior educational positions, similar district size, being located in or near a …

The analysis of protein residues recovered from archaeological artifacts provides a unique opportunity to reveal new information about past societies. However, many scientists are currently unwilling to accept protein-based results due to problems in method development and a basic lack of agreement regarding the ability of proteins to bind to, and preserve within, artifacts such as pottery. In this paper, I address these challenges by conducting a two-phase experiment. First, I quantitatively evaluate the tendency of proteins to sorb to ceramic matrices by using total organic carbon analysis and spectrophotometric assays to analyze samples of experimentally cooked ceramic. I then test a series of solvent and physical parameters in order to develop an optimized method for extracting and preparing protein residues for identification via mass spectrometry. Results demonstrate that protein strongly sorbs to ceramic and is not easily removed, despite repeated washing, unless an appropriate extraction strategy is used. This has implications for the future of paleodietary, conservation ecology and forensic research in that it suggests the potential for recovery of aged or even ancient proteins from ceramic matrices.

This Sustainable Development Report provides a comprehensive description of the economic, ecological and social challenges that are linked to Bayer's operations and show stakholders the strategies and solutions that are applying to meet them.

This quasi-experimental study examined the impact of living-learning communities on GPA and fall-to-fall retention rates for college freshmen at Regional University (RU). The specific focus of this study was the effect of these communities on students of different ethnic groups and on the potential of these communities to reduce the academic performance gap. RU was a small public university that offered both undergraduate and graduate degree programs. RU required all freshman students to live on campus in living-learning communities beginning with the 2007-2008 academic year. This study utilized the 343 student freshman cohort class of 2008 in the living-learning communities as the treatment group. This treatment group was compared against the 193 student freshman cohort class of 2008 living off campus and against the 643 student freshman cohort class of 2006 living on campus prior to the implementation of living-learning communities. In addition, the statistics were analyzed by ethnicity to examine the impact of these communities on White, Hispanic, African American, and Native American students and their ability to reduce the academic performance gap. The research revealed that the communities implemented at RU were not statistically significant at improving academic performance or at reducing the achievement gap. The results of …

Abuse and neglect occurring in childhood have been associated with a number of functional and physiological effects on the brain. This study extends previous research that investigated the quantitative electroencephalogram (qEEG) patterns in children with histories of relational trauma through the inclusion of additional participants and measures. As in previous studies, the relative power, absolute power, and coherence values in children with histories of abuse were compared to the Neuroguide database. Results did not show any significant differences in relative or absolute power in the theta range. Similarly, there were no significant coherence differences. Database comparisons were also made using low resolution electromagnetic tomography (LORETA) in order to determine which sub-cortical brain structures may be affected by abuse or trauma, though there were no significant differences in any frequency (0-30Hz). A review of the literature suggests that the prevalence of mu in normal adults and children ranges from 0 to 19%. The present study found a mu prevalence rate of 60.6% in the children who experienced abuse or neglect. Finally, comparisons were made between participants who demonstrate a mu pattern and those who do not to determine if this pattern is associated with certain behavioral and/or attention problems as assessed …

This Creature, Bride of Christ is a composition for soprano, alto flute, viola, marimba, and computer running custom software for live interactive performance in the Max/MSP environment. The work is a setting of excerpts from The Book of Margery Kempe, an early autobiographical manuscript depicting the life of a Christian mystic. The thesis discusses the historical, sociological, and musical context of the text and its musical setting; the use of borrowed materials from music of John Dunstable, Richard Wagner, and the tradition of change ringing; and the technologies used to realize the computer accompaniment. A score of the work is also included in the appendix.

This collection consists of a critical preface and five short stories. The preface analyzes what it terms 'fringe fiction,' or stories dealing with elements that are improbable or unusual, though not impossible, as it distinguishes this category from magical realism and offers guidelines for writing this kind of fiction. The short stories explore themes of attachment, loss, guilt, and hope. Collection includes the stories "Portrait," "Dress Up," "Change," "Drawn Onward, We Few, Drawn Onward," and "Broker."

Ruggiero's contributions to contemporary music are noteworthy. They include 27 works written for solo instruments, voice, as well as chamber groups and large ensembles. This study serves as an annotated bibliography of selected works written for saxophone by Charles Ruggiero. They include a piece for large chamber ensemble, Dig: From Tunes My Grandmother Heard (2009), a trio for flute, clarinet, and alto saxophone titled Echoes of "Piano Red" (2006), two saxophone quartets, Dig: JSB 1 (2003), and Three Blues for Saxophone Quartet (1981), two works for alto saxophone and piano, Night Songs and Flights of Fancy (2005), and Strayhorn (1999-2000), one piece for soprano saxophone and piano, Interplay for Soprano Saxophone and Piano (1988), a single movement work for alto saxophone, piano, winds, and percussion, Dance Complusions (2004), one duo for tenor saxophone and percussion, Sizzlesax II (2001), one concerto for soprano saxophone and piano, Concerto for Soprano Saxophone and Orchestra (1995, rev. 1999), and a trio for violin, alto saxophone, and piano, Dances and Other Movements (1983, rev. 1984). In addition, an analysis of Ruggiero's composition Interplay for Soprano Saxophone and Piano offers an insight into the compositional style of the composer.

This study used a semistructured interview schedule to identify the music career opportunities available to students who graduate with an undergraduate music degree, and the skills, interests, work values, and personal characteristics that may determine a person's suitability for these music careers. Six university faculty members from each of the 11 NASM-accredited undergraduate music degree fields participated in the study (n = 66). Fourteen professional musicians who were recommended by these faculty members also participated in the study. Concerning the musical and non-musical skills that may determine a person's suitability for a music career, participants consistently noted the importance of performance skills in their respective fields. Participants also consistently cited people skills, and noted that most musicians interact with people on a daily basis, and use people skills to build social networks that may lead to employment. When asked about the interests that may lead someone to a music career, participants commonly cited the importance of good high school ensemble experiences in students' music career decisions. Concerning the rewarding aspects of music careers, many participants noted that they were more rewarded by the ability to support themselves doing what they loved, than by fame or wealth. Concerning the personal characteristics …

The purpose of this study was to examine whether or not relationships exist between principals' technology proficiency and student achievement as indicated by 2008 Texas Assessment of Knowledge and Skills (TAKS) ninth grade reading scaled scores. Secondly, the study examined whether or not relationships exist between principals' leadership self efficacy and student achievement as indicated in the 2008 Texas Assessment of Knowledge and Skills (TAKS) ninth grade reading scaled scores. Lastly, the select principal's personal and school demographic variables (principal gender, total years of experience as a professional, total years as principal at current school, total years of principal experience, highest degree earned, school economic status, school size) were considered within the study. The survey instruments used in this study were the Technology Proficiency Self Assessment Scale (TPSA) developed by Ropp in 2000 and the Principal's Self-Efficacy Scale (PSES) developed by Tschannen-Moran and Garies in 2004. A total of 129 Texas principal's participated in the study. Multiple regressions were utilized and effect size was considered to determine the strength of the relationship between variables. A statistical significance was found relating to the school's social economic status only when using both the PSES and the TPSA instruments. The effect sizes reported …

Brochure containing information "to assist people wanting to create habitat and features that will attract wildlife to their backyards" (About the Author). The table of contents lists sections for: platform bird feeder, platform butterfly feeder, simple squirrel and dove feeder, suet feeder, solitary bees, pollinator box, general use nesting box, nesting platform, butterfly attracting plants, and hummingbird plants for Texas.

This study reports and evaluates child outcome measures at a non-profit autism treatment program providing applied behavior analysis (ABA) based services to children age 3 to 8. To accomplish this, a review was conducted of available outcome data for a 1 year period. Several categories of outcome measures have been reported in the autism treatment literature (post-intervention educational placement, cognitive status, developmental and achievement status and/or progress, autism symptom reduction, and diagnostic reclassification). This study found that the program relied on 2 sources of data to evaluate child outcome: Hawaii Early Learning Profile® and program goal mastery. Children are making progress as indicated by these measures. The findings are discussed in relation to broader outcome recommendations.