935 resultados para Explanatory Variables Effect
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Run-off-road (ROR) crashes have increasingly become a serious concern for transportation officials in the State of Florida. These types of crashes have increased proportionally in recent years statewide and have been the focus of the Florida Department of Transportation. The goal of this research was to develop statistical models that can be used to investigate the possible causal relationships between roadway geometric features and ROR crashes on Florida's rural and urban principal arterials. ^ In this research, Zero-Inflated Poisson (ZIP) and Zero-Inflated Negative Binomial (ZINB) Regression models were used to better model the excessive number of roadway segments with no ROR crashes. Since Florida covers a diverse area and since there are sixty-seven counties, it was divided into four geographical regions to minimize possible unobserved heterogeneity. Three years of crash data (2000–2002) encompassing those for principal arterials on the Florida State Highway System were used. Several statistical models based on the ZIP and ZINB regression methods were fitted to predict the expected number of ROR crashes on urban and rural roads for each region. Each region was further divided into urban and rural areas, resulting in a total of eight crash models. A best-fit predictive model was identified for each of these eight models in terms of AIC values. The ZINB regression was found to be appropriate for seven of the eight models and the ZIP regression was found to be more appropriate for the remaining model. To achieve model convergence, some explanatory variables that were not statistically significant were included. Therefore, strong conclusions cannot be derived from some of these models. ^ Given the complex nature of crashes, recommendations for additional research are made. The interaction of weather and human condition would be quite valuable in discerning additional causal relationships for these types of crashes. Additionally, roadside data should be considered and incorporated into future research of ROR crashes. ^
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Limited literature exists on Ghana's child domestic servants, and researchers have found it difficult to locate and study these children. The research for this dissertation used qualitative research methodologies and non-probabilistic sampling techniques to make it possible to interview child domestic servants, their parents, employers and recruiters in Ghana. The findings from the qualitative analyses informed the second part of this study, which was quantitative and tested hypotheses using crosstabulations and logistic regression analyses that were based on survey data from the Ghana Statistical Service. Explanatory variables in the quantitative analyses included lineage, level of education and relationships to the household head. ^ This study located findings about the processes of children's recruitment into domestic servitude, their working conditions and methods of remuneration in theories of slavery to answer the question of whether or not child domestic servants are slaves. According to the findings, elite households in Ghana exploit children from rural regions because they have taken advantage of a historical practice that allowed children to live with older members of their extended families to provide domestic services and in return, be given the chance to receive formal education or to learn a trade. The participants in the qualitative part of this research described the treatments that they receive from their employers as slavery. Nevertheless, the processes of their recruitment and the age at which most of them accepted such job offers made it difficult to categorize a majority of them as contemporary slaves. ^
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This dissertation explores the relationship between race and democratization. Through the examination of the case of the Dominican Republic, this study challenges mainstream explanations of democratic transitions. At its core, this dissertation aims at calling attention to the absence of race and ethnic allegiances as explanatory variables of the democratic processes and debates in the region. By focusing on structural variables, the analysis shies away from elite and actor-centered explanations that fall short in predicting the developments and outcomes of transitions. The central research questions of this study are: Why is there an absence of the treatment of race and ethnic allegiances during the democratic transitions in Latin America and the Caribbean? How has the absence of ethnic identities affected the nature and depth of democratic transitions? Unlike previous explanations of democratic transitions, this dissertation argues that the absence of race in democratic transitions has been a deliberate attempt to perpetuate limited citizenship by political and economic elites. Findings reveal a difficulty to overcome nationalist discourses where limited citizenship has affected the quality of democracy. Original field research data for the study has been gathered through semi-structured interviews and focus groups conducted from October 2008 to December 2009 in the Dominican Republic.
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This dissertation addresses the following research question: in a particular policy area, why do countries that display unanimity in their international policy behavior diverge from each other in their domestic policy actions? I address this question in the context of the divergent domestic competition policy actions undertaken by developing countries during the period 1996-2007, after these countries had quite conspicuously displayed near-unanimity in opposing this policy measure at the World Trade Organization (WTO). This divergence is puzzling because (a) it does not align with their near-unanimous behavior at the WTO over competition policy and (b) it is at variance with the objectives of their international opposition to this policy at the WTO. Using an interdisciplinary approach, this dissertation examines the factors responsible for this divergence in the domestic competition policy actions of developing countries. ^ The theoretical structure employed in this study is the classic second-image-reversed framework in international relations theory that focuses on the domestic developments in various countries following an international development. Methodologically, I employ both quantitative and qualitative methods of analysis to ascertain the nature of the relationship between the dependent variable and the eight explanatory variables that were identified from existing literature. The data on some of the key variables used in this dissertation was uniquely created over a multi-year period through extensive online research and represents the most comprehensive and updated dataset currently available. ^ The quantitative results obtained from logistic regression using data on 131 countries point toward the significant role played by international organizations in engineering change in this policy area in developing countries. The qualitative analysis consisting of three country case studies illuminate the channels of influence of the explanatory variables and highlight the role of domestic-level factors in these three carefully selected countries. After integrating the findings from the quantitative and qualitative analyses, I conclude that a mix of international- and domestic-level variables explains the divergence in domestic competition policy actions among developing countries. My findings also confirm the argument of the second-image-reversed framework that, given an international development or situation, the policy choices that states make can differ from each other and are mediated by domestic-level factors. ^
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During the past two decades there has been much research conducted on the relationship between the risky sexual behavior practices and substance use among U.S. adolescents. This body of research has documented the fact that substance use and not using condoms are the most important indicators associated with the risk of becoming infected with sexually transmitted diseases (STD) both among adolescents and adults (Florida Department of Public Health, 2004; Malow, Devieux, Jennings, & Lucenko, 2001; McCoy & Inciardi, 1995). Data from those reports and studies indicate that adolescents and adults who use a condom regularly and appropriately are 20 times less likely to contract an STD than those who do not (Pinkerton & Abramson, 1997). However, less empirical evidence exists about the factors that influence adolescent use of condoms, particularly among adolescents who are detained due to their criminal lifestyle. Researchers have found both a high prevalence of STD in addition to early onset of sexual activity without protection among some adolescent groups such as the detainees (D'angelo & DiClemente, 1996) and that adolescents tend to underestimate their risks of acquiring the human immunodeficiency virus (HIV) (Magura, Shapiro, & Kang, 1994). Many adolescents will experiment with alcohol and other drugs. This behavior may compromise their judgment and increase their chances of engaging in risky sex (Rotheram-Borus, 2000). Hence the need for research that investigates the influence that substance use, risky sexual attitudes, knowledge about the transmission of HIV, and both peer and parental approval of condom use have on the use of condoms among both female and male adolescent detainees. Lastly, it is important for additional research to be conducted because adolescent detainees have been identified as being at high risk of becoming infected with an STD (Malow, Rosemberg, & Devieux, 2006). The purpose of this study was to examine the relationship among adolescent substance use, gender, sexual risk attitude, attitude about personal use of condoms, knowledge associated with the transmission of HIV, peer and family approval of condom use, history of sexually transmitted diseases (STD) and the level of condom use in a sample of adolescents housed in a correctional institution. Further details of the explanatory variables, the control variables and their expected relationships can be found in the review of the Literature in Chapter 2. Also, more information about the separate analysis of the research questions is detailed in the Methods section in Chapter 3. Based on the literature detailed in Chapter 2 (e.g., Malow et al., 2006), the current study’s researcher anticipated that adolescents’ higher levels of illicit drug use would be related to higher levels of sexual risk behaviors, as measured by lower levels of condom use, than their counterparts who used no drugs. Similarly, it was hypothesized that positive attitudes toward condom use and higher levels of HIV risk knowledge would be associated with a lower level of risky sexual behaviors along with a higher level of condom use skill. It was further hypothesized that the level of approval perceived from parents and peers regarding condom use was going to be related to adolescents’ safe sex behavior (i.e., condom use). Therefore, it was expected that participants’ perception of a high level of approval to use condoms from peers and parents would be a statistically significant variable in helping explain the condom use within this sample of adolescent detainees.
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This dissertation explores the relationship between race and democratization. Through the examination of the case of the Dominican Republic, this study challenges mainstream explanations of democratic transitions. At its core, this dissertation aims at calling attention to the absence of race and ethnic allegiances as explanatory variables of the democratic processes and debates in the region. By focusing on structural variables, the analysis shies away from elite and actor-centered explanations that fall short in predicting the developments and outcomes of transitions. The central research questions of this study are: Why is there an absence of the treatment of race and ethnic allegiances during the democratic transitions in Latin America and the Caribbean? How has the absence of ethnic identities affected the nature and depth of democratic transitions? Unlike previous explanations of democratic transitions, this dissertation argues that the absence of race in democratic transitions has been a deliberate attempt to perpetuate limited citizenship by political and economic elites. Findings reveal a difficulty to overcome nationalist discourses where limited citizenship has affected the quality of democracy. Original field research data for the study has been gathered through semi-structured interviews and focus groups conducted from October 2008 to December 2009 in the Dominican Republic.
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Aim: To investigate the characteristics, development and determinants of toothwear among Irish schoolchildren. Methods: A cross-sectional (examination at 16-years-old) and longitudinal (examinations at 5-,12-,14-years) study were conducted. Two indices were used to measure toothwear, children/parents completed a demographic profile and questionnaire on oral hygiene and dietary practices, health, and lifestyle in both studies. Saliva was collected from consenting 16-year-olds. The explanatory variables for the cross-sectional and longitudinal study were derived from children/parents responses. Differences in salivary profiles were determined for subsets; the protein concentration was determined with Bradford protein assay and protein carbonyl concentration (a protein oxidation marker) was determined spectrophotometrically. Gel-electrophoresis and mass spectrometry determined proteins and ion chromatography inorganic ions. Statistical significance was accepted at p<0.05. Results: At 16-years-old the prevalence of toothwear with dentine visible was 44%. No difference in salivary flow rates existed. In unstimulated saliva a higher mean, protein carbonyl (p<0.0001) and total calcium concentration (p<0.002) existed for the group with moderate toothwear. In stimulated saliva the moderate toothwear group had a lower mean protein concentration(p<0.0001). The 2-DE protein spots prepared for a sub-group differed between those with toothwear and without. Mass spectrometry, identified one of the different proteins as IgA. For 16-year-olds, the self-reported factors indicated that brushing after breakfast was associated with lower toothwear scores(p<0.03). Nail-biting, being asthmatic or reporting a dry mouth were associated with higher toothwear scores(all p<0.05). Eating an apple daily or less was associated with less toothwear(p<0.002). In the longitudinal study toothwear into dentine at age five or 12-years was associated with more toothwear at age 14(all p<0.05). Discussion: The results illustrate the multifactorial aetiology of toothwear. The biochemical and physical correlates of saliva with toothwear requires further research. Conclusion: The impact of previous toothwear, salivary, dietary and personal factors on toothwear in the early permanent dentition is demonstrated.
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Adipose tissue was sampled from the western Hudson Bay (WHB) subpopulation of polar bears at intervals from 1991 to 2007 to examine temporal trends of PCB and OCP levels both on an individual and sum-contaminant basis. We also determined levels and temporal trends of emerging polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), polybrominated biphenyls (PBBs) and other current-use brominated flame retardants. Over the 17-year period, sum DDT (and p,p'-DDE, p,p'-DDD, p,p'-DDT) decreased (-8.4%/year); alpha-hexachlorocyclohexane (alpha-HCH) decreased (-11%/year); beta-HCH increased ( + 8.3%/year); and sum PCB and sum chlordane (CHL), both contaminants at highest concentrations in all years (>1 ppm), showed no distinct trends even when compared to previous data for this subpopulation dating back to 1968. Some of the less persistent PCB congeners decreased significantly (-1.6%/year to -6.3%/year), whereas CB153 levels tended to increase (+ 3.3%/year). Parent CHLs (c-nonachlor, t-nonachlor) declined, whereas non-monotonic trends were detected for metabolites (heptachlor epoxide, oxychlordane). sum chlorobenzene, octachlorostyrene, sum mirex, sum MeSO2-PCB and dieldrin did not significantly change. Increasing sum PBDE levels (+13%/year) matched increases in the four consistently detected congeners, BDE47, BDE99, BDE100 and BDE153. Although no trend was observed, total-(alpha)-HBCD was only detected post-2000. Levels of the highest concentration brominated contaminant, BB153, showed no temporal change. As long-term ecosystem changes affecting contaminant levels may also affect contaminant patterns, we examined the influence of year (i.e., aging or "weathering" of the contaminant pattern), dietary tracers (carbon stable isotope ratios, fatty acid patterns) and biological (age/sex) group on congener/metabolite profiles. Patterns of PCBs, CHLs and PBDEs were correlated with dietary tracers and biological group, but only PCB and CHL patterns were correlated with year. DDT patterns were not associated with any explanatory variables, possibly related to local DDT sources. Contaminant pattern trends may be useful in distinguishing the possible role of ecological/diet changes on contaminant burdens from expected dynamics due to atmospheric sources and weathering.
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The purpose of this study is to understand, impact and evaluate the development of intercultural communicative competencies among European credit-seeking exchange students and other sojourners through purposeful intercultural pedagogy. This pedagogy encompasses intentional intercultural- educational approaches which aim to support and enhance sojourners’ intercultural learning throughout the study abroad cycle (pre-departure, in-country and reentry phases). To test and validate these pedagogies a 20-hour intervention was designed and implemented among two cohorts of 31 sojourners during the in-country phase of their sojourn in Portugal. The process to develop and validate the intercultural intervention was driven by a mixed-methods methodology which combined quantitative and qualitative data to triangulate, complement and expand research results from a pragmatic stance. The mixed methods research design adopted is multi-phased and encompasses a multi-case study and an evaluative component. The multi-case component is embodied by sojourner cohorts: (1) the primary case study involves 19 incoming students at the University of Aveiro (Portugal) as participants in the European exchange program Campus Europae; (2) the second case study comprises three incoming Erasmus students and nine highly skilled immigrants at the same university. All 31 sojourners attended two intermediate Portuguese as Foreign Language classrooms where the intervention was employed. Data collection was extensive and involved collecting, analyzing and mixing quantitative and qualitative strands across four research phases. These phases refer to the: (1) development, (2) implementation and (3) evaluation of the intervention, as well as to (4) a stakeholder analysis of the external value of the intervention and of the Campus Europae program. Data collection instruments included pre and posttest questionnaires and semi-structured interviews. Results confirm the intercultural effectiveness of the intervention and the positive impact upon research participants’ intercultural gains. This impact was, however, greater in case study 2. Among explanatory variables, three stand out: (1) participant meaning-making abilities, (2) host language proficiency and related variables, and (3) type of sojourn or exchange programs. Implications for further research highlight the need to systematize purposeful intercultural pedagogy in sojourner populations in general, and in European credit student mobility in particular. In the latter case, these pedagogies should be part of the design and delivery of credit-bearing exchange programs in pre- departure, in-country and re-entry phases. Implications for practice point to the urge to improve intercultural practices in: macro (higher education institutions), mezzo (exchange programs) and micro (sojourner language classrooms) contexts where this research took place, and wider social scenarios they represent.
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O presente artigo tem por objetivo analisar empiricamente os determinantes do financiamento do investimento nos países das Américas no período de 1972-2008, tendo como base teórica os modelos de hiatos nas versões de Chenery e Bruno (1962); Bacha (1982, 1989 e 1990) e Taylor (1994). Com este intuito, realiza-se uma estimação com o modelo de dados em painel na versão padrão com efeitos fixos. As variáveis explicativas de cada país seguem a abordagem de Amadeo e Giambiagi (1990). São elas: os coeficientes de poupança interna e de importação e as exportações reais. Os resultados das estimações corroboram com a concepção teórica do modelo de hiatos, ou seja, que países em desenvolvimento enfrentam limitações de poupança interna e incapacidade de importar bens intensivos em capital, fatores os quais restringem o nível de investimento dessas economias.
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Neste estudo são analisados, através de técnicas adequadas para dados em painel, os determinantes da liquidez das empresas portuguesas cotadas na Euronext Lisbon. Para a concretização do mesmo foi utilizada uma amostra de 40 empresas, para o período de 2000 a 2014, sendo este período dividido em dois subperíodos, o antes e o depois da crise. Os resultados evidenciam a existência de uma relação entre algumas das variáveis independentes e a variável dependente. De facto, antes da crise, verifica-se que as oportunidades de crescimento e a probabilidade de dificuldades financeiras são significativas para o nível da liquidez, sendo que, depois da crise, as variáveis explicativas do nível de liquidez são a volatilidade dos fluxos de caixa, o ciclo de conversão de caixa e a probabilidade de dificuldades financeiras.
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Background: In Nigeria, the relationship between spousal violence and pregnancy termination had not been adequately explored. Objectives: To assess the prevalence of spousal violence, and examine the relationship between spousal violence and pregnancy termination. Methods: Data on spousal violence among ever married women was extracted from the 2013 Nigeria Demographic and Health Survey. The outcome variable is pregnancy termination. The explanatory variables were the type of spousal violence experienced by the women in the last 12 months preceding the survey. Descriptive statistical analysis and binary logistic regression were applied using stata version 12. Results: Results show that 13.8% of women had ever terminated pregnancy; 19.9% had ever experienced at least one type of spousal violence; and women who had ever terminated pregnancy had higher prevalence of all types of spousal violence. Women who had ever experienced spousal physical violence were 9% more likely to experience pregnancy termination (OR=1.09; CI: 1.03-2.86); and women who had ever experienced spousal emotional violence were 33% more likely to experience pregnancy termination (OR=1.33; CI: 0.97-1.95). Conclusions: Spousal violence is significantly related to pregnancy termination. Improving women’s sexual and reproductive health in the country requires fresh initiatives that address spousal violence to further reduce women’s exposure to pregnancy termination.
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Repercussions of innovation adoption and diffusion studies have long been imperative to the success of novel introductions. However, perceptions and deductions of current innovation understandings have been changing over time. The paradigm shift from the goods-dominant (G-D) logic to the service-dominant (S-D) logic potentially makes the distinction between product (goods) innovation and service innovation redundant as the S-D logic lens views all innovations as service innovations (Vargo and Lusch, 2004; 2008; Lusch and Nambisan, 2015). From this perspective, product innovations are in essence service innovations, as goods serve as mere distribution mechanisms to deliver service. Nonetheless, the transition to such a broadened and transcending view of service innovation necessitates concurrently a change in the underlying models used to investigate innovation and its subsequent adoption. The present research addresses this gap by engendering a novel model for the most crucial period of service diffusion within the S-D logic context – the post-initial adoption phase, which demarcates an individual’s behavior after the initial adoption decision of a service. As a wellfounded understanding of service diffusion and the complementary innovation adoption still lingers in its infancy, the current study develops a model based on interdisciplinary domains mapping. Here fore, knowledge of the relatively established viral source domain is mapped to the comparatively undetermined target domain of service innovation adoption. To assess the model and test the importance of the explanatory variables, survey data from 750 respondents of a bank in Northern Germany is scrutinized by means of Structural Equation Modeling (SEM). The findings reveal that the continuance intention of a customer, actual usage of the service and the customer influencer value all constitute important postinitial adoption behavior that have meaningful implications for a successful service adoption. Second, the four constructs customer influencer value, organizational commitment, perceived usefulness and service customization are evidenced to have a differential impact on a iv customer’s post-initial adoption behavior. Third, this study indicates that post-initial adoption behavior further underlies the influence of a user’s age and besides that is also provoked by the internal and external environments of service adoption. Finally, this research amalgamates the broad view of service innovation by Nambisan and Lusch (2015) with the findings ensuing this enquiry’s model to arrive at a framework that it both, generalizable and practically applicable. Implications for academia and practitioners are captured along with avenues for future research.
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El objetivo principal del presente estudio consistió en evaluar la existencia o no de disciplina de mercado en el sistema bancario costarricense lo cual puede ser una evidencia importante previo al posible establecimiento de un Fondo de Garantía de los depósitos bancarios en Costa Rica.De acuerdo con los resultados de las estimaciones, podría afirmarse que la hipótesis de la existencia de disciplina de mercado en el sistema bancario costarricense se comprobó aunque de una manera muy débil o incipiente.La mayor parte de las variables fundamentales del desempeño y que reflejan el nivel de riesgo asumido por los intermediarios bancarios no parecen tener influencia sobre el comportamiento de los depósitos al igual que con la mayoría de las variables macroeconómicas.Los resultados también indican que la captación en cada uno de los bancos comerciales, si bien reacciona de igual manera ante los cambios en las variables explicativas, cada una de las instituciones presenta ciertas particularidades que los hacen diferentes entre sí. AbstractThe primary target of the present study consisted of evaluating the existence or not of market discipline in the Costa Rican banking system which can be previous an important evidence to the possible establishment of a guarantee system of the banking deposits in Costa Rica.In agreement with the results of the estimations, it could affirm that the hypothesis of the existence of market discipline in the Costa Rican banking system was verified although of a very weak or incipiente way.Most of the fundamental variables of the performance and that they reflect the level of risk assumed by the banking intermediaries does not seem to have influence on the behavior of the deposits like with most of the macroeconomic variables.The results also indicate that the pick up of funds in each one of the commercial banks, although reacts of equal way before the changes in the explanatory variables, each one of the institutions displays certain characteristics that are reflected in different intercepts.
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Mestrado em Ciências Actuariais