Essa pesquisa busca investigar a influência de diferentes níveis de fatores na variância da maturidade do endividamento corporativo na América Latina. Ao todo, foram levantados cinco diferentes grupos (divididos em três níveis de influência) de variáveis que potencialmente determinam a maturidade do endividamento das empresas dos países estudados ao longo do período de 1996 a 2009. Foi utilizado o modelo linear hierárquico, que possibilita o aninhamento de variáveis em diferentes níveis – em que os níveis superiores influenciam os níveis inferiores. Ao longo do estudo, procedeu-se à análise fatorial com o objetivo de extrair fatores representativos do nível de desenvolvimento financeiro e da qualidade das instituições de Argentina, Brasil, Chile, Colômbia, México, Peru, Venezuela e Estados Unidos (países componentes da amostra). Os resultados sugerem que as variações ao longo do tempo e as variações entre as empresas são as maiores fontes de modificações na maturidade do endividamento. Além disso, o tamanho, a liquidez, a taxa real de juros e o nível de desenvolvimento financeiro do país se sobressaem como fatores que impactam de forma significativa a maturidade do endividamento corporativo. Finalmente, os fatores extraídos e a taxa real de juros impactaram indiretamente na maturidade do endividamento através de outras variáveis, a saber: oportunidades de crescimento, tamanho e liquidez. / This research investigates the influence of distinct factor´s levels in corporate debt maturity in Latin America. Five different variables groups (divided into three influence levels) that potentially determine the corporate debt maturity in the countries studied were collected over the period 1996 to 2009. We used Hierarchical Linear Modeling, which allows nesting of variables at different levels – in which the higher levels may influence the lower levels. Throughout the study, we proceeded to factor analysis in order to extract financial development and institutional quality factors in Argentina, Brazil, Chile, Colombia, Mexico, Peru, Venezuela and the United States (countries belonging to the sample). The results suggest that variations over time and variations between firms are the major sources of changes in corporate debt maturity. Moreover, size, liquidity, the real interest rate and the financial development stand out as factors that impact significantly the corporate debt maturity. Finally, the extracted factors and the real interest rate indirectly impacted the corporate debt maturity by others variables, namely: growth opportunities, size and liquidity.

Grounded in Bronfenbrenner's (1979) Ecological Systems Theory and through the application of cross-classified random effects models, the goal of this study was to examine simultaneously neighborhood and school influences on adolescent academic achievement and risk of obesity, as well as the moderating effects of schools on these outcomes. By examining concurrently neighborhood and school influences on achievement and risk of obesity, this study aimed to fill gaps in the social determinants literature. For example, it is unclear if where an adolescent lives or where she/he attends school has a stronger influence on academic achievement. We also do not know if schools can moderate neighborhood influences on adolescent achievement, nor do we know much about the relationships among schools, neighborhoods, and adolescent risk for obesity. Using data from the National Longitudinal Study of Adolescent Health and the Adolescent Health and Academic Achievement study, four research questions were investigated: (1) To what extent are neighborhood influences on U.S. middle and high school students' academic achievement moderated by school environments? (2) What are the relative influences of neighborhood and school environments on U.S. middle and high school students' academic achievement? (3) To what extent are neighborhood influences on U.S. middle and high school students' risk of obesity moderated by school environments? (4) What are the relative influences of neighborhood and school environments on U.S. middle and high school students' risk of obesity? Findings did not suggest a moderating relationship between neighborhood and school factors examined in this study. In terms of relative relationships with academic achievement, three neighborhood factors (affluence, racial composition, and urbanicity) and two school characteristics (student body racial composition and school socioeconomic status) appeared to have the strongest relationships with adolescent achievement after controlling for individual and other neighborhood and school characteristics. For adolescent risk of obesity, neighborhood affluence and racial composition had statistically significant unique associations, whereas no school factors evidenced statistically significantly relationships with risk of obesity after controlling for other factors. Results of the study were interpreted in terms of contributions to the social determinants literature, as well as recommendations for the improvement of future large-scale surveys.

Emotionally Focused Couple Therapy (EFT; Johnson, 2004) is an empirically validated approach to couple therapy that uses attachment theory to understand the needs and emotions of romantic partners. In EFT, relationship distress is conceptualized as resulting from negative affect, emotional disconnection, and unmet attachment needs. Although EFT is recognized as one of the most researched and effective approaches to couple therapy, little research has examined theoretically related characteristics of couples to changes in marital satisfaction throughout EFT. The present doctoral thesis examined this area of literature. Thirty-two couples were provided approximately 21 sessions of EFT. The goal of the first study was to identify intake characteristics related to change in marital satisfaction over the course of EFT. Couples completed self-report measures of marital satisfaction, attachment security, relationship trust, and emotional control at pre- and post-therapy and after each therapy session. Individuals higher on self-report attachment anxiety and higher levels of emotional control had greater change in marital satisfaction over the course of EFT. The goal of the second study was to examine intake levels of attachment security and its relationship to the occurrence of the blamer-softening event, a key change event in EFT, and changes in marital satisfaction. Results indicated that the occurrence of a blamer-softening event significantly predicted positive changes in marital satisfaction. Results also suggested that the occurrence of a softening event significantly moderated the relationship between attachment avoidance at intake and change in marital satisfaction from pre- to post-therapy. For couples who completed a blamer-softening event, partners with lower levels of attachment avoidance were more likely to have positive changes in marital satisfaction. However, this relationship was not evident for attachment anxiety. Overall, results from this thesis suggest that attachment security is a key characteristic of couple partners for therapists to consider when implementing EFT. Therapists may benefit from assessing attachment security at the start of therapy to help inform them of the emotion regulating strategies used by couple partners. This information may help therapists to tailor specific interventions such that couples may begin to develop more secure attachment bonds.

Exposure therapy has received a great deal of support as an effective treatment for social anxiety. However, not all those who undergo exposure therapy improve, and some of those who do respond continue to report significant levels of symptoms. A theorized mechanism of change for exposure therapy is extinction learning. Extinction learning is believed to occur across exposure sessions during which new associations are formed and stored in memory. Individuals with social anxiety are prone to engage in post event processing (PEP), or rumination, after social experiences, which may interfere with extinction learning, and thus attenuate response to treatment. The current study examined whether PEP limits treatment response to two different exposure based treatments, a group based cognitive behavioral intervention and an individually based virtual reality exposure therapy among participants (n = 75) diagnosed with social anxiety disorder. The findings suggested that PEP decreased as a result of treatment and that social anxiety symptoms for those with greater amounts of PEP improved at a slower rate of change than those with lower levels of PEP. Implications for the role of PEP on treatment response are discussed.

Parent child communications about sex play an important role in influencing adolescent’s sexual behaviors and attitudes. The present study was conducted to examine how sexual communications between African American mothers and their children change over a period of three years in the areas of sex education, communication about risk reduction, and child and parent report of responsiveness. Hierarchical linear modeling (HLM) analyses found significant linear or curvilinear trajectory in communication with sons and daughters in all areas. Gender differences were found such that daughters received more communication than sons. Furthermore, daugthers’ sexual maturation was found to be associated with a decrease in the rate of decline of communication about general sex information. For sons, mothers decreased in rates of responsiveness as sons got older; however, as sons’ sexual maturation increased, rates of declining responsiveness slowed down.

The effects of program fidelity, gender, socioeconomic status, and school level were tested on various outcomes of a dating violence prevention program, Expect Respect. Fidelity data was collected from program facilitators, and individual posttest scores were gathered for individuals nested within each programmatic site. Multiple HLM models indicated that main effects for fidelity were present for the knowledge gained outcome scale, such that higher program fidelity led to higher posttest scores for participants. No other site level predictors affected outcomes or the fidelity-outcome relationship. Results from this study point towards the importance of implementing program fidelity when cognitive gains are a central goal of the program, whereas a more flexible program approach may be more optimal in conveying other programmatic components.

Program evaluations are increasingly assessing the impact of treatment delivery and program processes on outcomes. The current study examined the effects of program fidelity, measured across various dimensions, and relationship quality on behavior change and knowledge gained outcomes in 241 middle and high school students who were participating in Expect Respect, an evidence-based dating violence prevention program. Cross-level, hierarchical linear modeling (HLM) analyses found that program fidelity was not a significant predictor of participant outcomes. However, main effects for relationship quality were present for the knowledge gained outcome measure. Subsequent cross-level interactions provided further support for the importance of relationship quality in prevention program outcomes.

This study consists of developing descriptive, parametric, linear and non-linear statistical models for such natural phenomena as hurricanes, lightning, flooding, red tide and volcanic fallout. In the present study, the focus of research is determining the stochastic nature of phenomena in the environment. These statistical models are necessary to address the variability of nature and the misgivings of the deterministic models, particularly when considering the necessity for man to estimate the occurrence and prepare for the aftermath.The relationship between statistics and physics looking at the correlation between wind speed and pressure versus wind speed and temperature play a significant role in hurricane prediction. Contrary to previous studies, this study indicates that a drop in pressure is a result of the storm and less a cause. It shows that temperature is a key indicator that a storm will form in conjunction with a drop in pressure. This study demonstrates a model that estimates the wind speed within a storm with a high degree of accuracy. With the verified model, we can perform surface response analysis to estimate the conditions under which the wind speed is maximized or minimized. Additional studies introduce a model that estimates the number of lightning strikes dependent on significantly contributing factors such as precipitable water, the temperatures within a column of air and the temperature range. Using extreme value distribution and historical data we can best fit flood stages, and obtain profiling estimate return periods. The natural logarithmic count of Karenia Brevis was used to homogenize the variance and create the base for an index of the magnitude of an outbreak of Red Tide. We have introduced a logistic growth model that addresses the subject behavior as a function of time and characterizes the growth rate of Red Tide. This information can be used to develop strategic plans with respect to the health of citizens and to minimize the economic impact. Studying the bivariate nature of tephra fallout from volcanoes, we analyze the correlation between the northern and eastern directions of a topological map to find the best possible probabilistic characterization of the subject data.

A large body of evidence supports the notion that chronic stress and strain may impact healing from physical trauma. However, no evidence exists to substantiate whether chronic stress impacts recovery from exercise-induced muscle damage. In this study, a group of 31 undergraduate weight-training students completed the Perceived Stress Scale (PSS), Undergraduate Stress Survey (USQ, a measure of life event stress) a series of fitness tests and then returned 5 to 10 days later for an exhaustive resistance exercise stimulus (E-RES) workout. This workout was performed on a leg press to the cadence of a metronome to ensure a strong eccentric component of exercise. Participants were monitored for 1 hour after this workout and every day for 4 days afterwards. Hierarchical Linear Modeling (HLM) multi-level growth curve analyses demonstrated that stress measures were related to recovery from maximal resistance exercise for both functional muscular (maximal isometric force, jump height, and cycling power) and psychological (perceived energy, perceived fatigue, and soreness) outcomes. Stress was not related to outcomes immediately post-workout (except maximal cycling power) after controlling for pre-workout values. Thus, the effect of stress on recovery is not likely due to magnitude of disruption from maximal exercise. After controlling for significant covariates, including fitness and percent disruption from baseline, individuals scoring a 10 on the PSS at their first visit reached baseline 288% (2.88 times) faster than individuals who scored a 19 at this same time point. There were significant moderating effects of stress on affective responses during exercise. Feeling (pleasure/displeasure), activation (arousal), muscular pain and RPE (exertion) trajectories were moderated by stress. Exploratory analyses found that stress moderated physical recovery, but not psychological recovery in the first hour after the E-RES workout. Also, stress was related to the increase in IL-1[beta], a pro-inflammatory cytokine, in the 48 hour period after exercise for a sub-set of participants. These findings likely have important theoretical and clinical implications for those undergoing vigorous physical activity. Those experiencing chronic loads of stress and mental strain should include more rest time to ensure proper recovery. / text

This work presents an evaluation of a reform teaching practice, known as peer-led guided inquiry, that combines guided inquiry and cooperative learning for college chemistry teaching. Integral to implementing the reform in a large class (greater than 100 students) was the role of peer leaders, undergraduate students who have successfully completed the target course. These peer leaders facilitated cooperative learning groups during weekly guided inquiry activities in general chemistry. The evaluation, using data collected over a 3-year period, had two main foci: effective teaching and promotion of equity in the classroom. Both of these aims were evaluated using hierarchical linear models. The reform was found to be effective, with a progressive increase in the test scores of those students in the reform classes versus the students in the traditional classes. Furthermore, students in the reform outperformed their counterparts on an externally-constructed national exam. Both findings also held true when controlling for student SAT scores. Effectiveness is not sufficient cause for recommendation amid concerns that distinct groups of students may be disadvantaged by a reform. The evaluation therefore had special concern for students who were at significant risk of low performance in a college chemistry course, such as those with poor high school preparation. No evidence was found that the reform made the situation worse for these students; in fact, the reform was determined to be effective regardless of preparation as measured by SAT scores. In addition, formal thought ability was found to be an important factor in chemistry performance, independent of SAT scores, with low formal thought ability placing students at-risk. The evaluation data indicated that the reform may have allowed students who entered the course with low formal thought ability to overcome this disadvantage, though this effect could be attributed to chance. Finally, to understand further the students in this setting beyond cognitive factors, an inventory of student study approaches was administered. Three specific approach profiles were prevalent: surface, surface achieving and achieving. Two less prevalent approach profiles, deep and deep achieving, were related to better understanding of chemistry as measured by the national exam.