Infection levels of eastern oysters by the unicellular pathogen Perkinsus marinus have been associated with anthropogenic influences in laboratory studies. However, these relationships have been difficult to investigate in the field because anthropogenic inputs are often associated with natural influences such as freshwater inflow, which can also affect infection levels. We addressed P. marinus-land use associations using field-collected data from Murrells Inlet, South Carolina, USA, a developed, coastal estuary with relatively minor freshwater inputs. Ten oysters from each of 30 reefs were sampled quarterly in each of 2 years. Distances to nearest urbanized land class and to nearest stormwater outfall were measured via both tidal creeks and an elaboration of Euclidean distance. As the forms of any associations between oyster infection and distance to urbanization were unknown a priori, we used data from the first and second years of the study as exploratory and confirmatory datasets, respectively. With one exception, quarterly land use associations identified using the exploratory dataset were not confirmed using the confirmatory dataset. The exception was an association between the prevalence of moderate to high infection levels in winter and decreasing distance to nearest urban land use. Given that the study design appeared adequate to detect effects inferred from the exploratory dataset, these results suggest that effects of land use gradients were largely insubstantial or were ephemeral with duration less than 3 months.

BACKGROUND:Interruption of vector-borne transmission of Trypanosoma cruzi remains an unrealized objective in many Latin American countries. The task of vector control is complicated by the emergence of vector insects in urban areas.METHODS:Utilizing data from a large-scale vector control program in Arequipa, Peru, we explored the spatial patterns of infestation by Triatoma infestans in an urban and peri-urban landscape. Multilevel logistic regression was utilized to assess the associations between household infestation and household- and locality-level socio-environmental measures.RESULTS:Of 37,229 households inspected for infestation, 6,982 (18.8% / 95% CI: 18.4 - 19.2%) were infested by T. infestans. Eighty clusters of infestation were identified, ranging in area from 0.1 to 68.7 hectares and containing as few as one and as many as 1,139 infested households. Spatial dependence between infested households was significant at distances up to 2,000 meters. Household T. infestans infestation was associated with household- and locality-level factors, including housing density, elevation, land surface temperature, and locality type.CONCLUSIONS:High levels of T. infestans infestation, characterized by spatial heterogeneity, were found across extensive urban and peri-urban areas prior to vector control. Several environmental and social factors, which may directly or indirectly influence the biology and behavior of T. infestans, were associated with infestation. Spatial clustering of infestation in the urban context may both challenge and inform surveillance and control of vector reemergence after insecticide intervention.

Smoking rates among senior students have been related to smoking initiation in younger students. Opportunities to select smoking friends may be one explanation, however our understanding of this process has been limited by cross-sectional designs. <br ><br /> The purpose of this longitudinal study was to determine whether senior student smoking rates a) predict smoking initiation in younger elementary school students, controlling for individual exposure to family and friends who smoke and b) are related to the selection of smoking friends, increasing risk of smoking initiation as a result. <br ><br /> This study involved secondary data analysis of 2798 students from 84 Ontario elementary schools involved with the Third Waterloo Smoking Prevention Project (WSPP3). Grade 8 students completed a questionnaire at baseline to obtain the percentage of senior students who smoke in each school. Students in grade 6 completed a similar questionnaire at baseline, and were surveyed again in grades 7 and 8. Multilevel regression analyses were used to examine school and individual characteristics simultaneously. <br ><br /> Each 5% increase in the senior student smoking rate at a school increased the risk that a non-smoking grade 6 student would try smoking more than once by grade 8 (OR 1. 05) and that a non-smoking grade 6 student with no smoking friends would gain a smoking friend by grade 7 (OR 1. 10). Students who remained non-smokers in grade 7 but gained a smoking friend were more likely to try smoking more than once by grade 8 (OR 4. 31). <br ><br /> In schools where a high proportion of senior students smoked, younger students were more likely to initiate smoking, and gain a smoking friend. Anti-smoking policies and interventions may be more urgently required in these schools to lower senior student smoking rates and reduce initiation among younger students. Tailoring the intensity and content of programs to match the needs of schools is one way to potentially maximize effectiveness.

Smoking rates among senior students have been related to smoking initiation in younger students. Opportunities to select smoking friends may be one explanation, however our understanding of this process has been limited by cross-sectional designs. <br ><br /> The purpose of this longitudinal study was to determine whether senior student smoking rates a) predict smoking initiation in younger elementary school students, controlling for individual exposure to family and friends who smoke and b) are related to the selection of smoking friends, increasing risk of smoking initiation as a result. <br ><br /> This study involved secondary data analysis of 2798 students from 84 Ontario elementary schools involved with the Third Waterloo Smoking Prevention Project (WSPP3). Grade 8 students completed a questionnaire at baseline to obtain the percentage of senior students who smoke in each school. Students in grade 6 completed a similar questionnaire at baseline, and were surveyed again in grades 7 and 8. Multilevel regression analyses were used to examine school and individual characteristics simultaneously. <br ><br /> Each 5% increase in the senior student smoking rate at a school increased the risk that a non-smoking grade 6 student would try smoking more than once by grade 8 (OR 1. 05) and that a non-smoking grade 6 student with no smoking friends would gain a smoking friend by grade 7 (OR 1. 10). Students who remained non-smokers in grade 7 but gained a smoking friend were more likely to try smoking more than once by grade 8 (OR 4. 31). <br ><br /> In schools where a high proportion of senior students smoked, younger students were more likely to initiate smoking, and gain a smoking friend. Anti-smoking policies and interventions may be more urgently required in these schools to lower senior student smoking rates and reduce initiation among younger students. Tailoring the intensity and content of programs to match the needs of schools is one way to potentially maximize effectiveness.

Introdução: Estudos anteriores mostraram a efetividade do Projeto VIVALEITE para o ganho de peso de crianças menores de dois anos. Como o programa é efetivo, é possível que crianças ingressantes com peso próximo ao limite considerado adequado para idade o ultrapassem no decorrer de sua participação. Verificar se há variáveis sociodemográficas associadas ao excesso de peso poderá permitir o estabelecimento de medidas preventivas por parte dos gestores do programa. Objetivo: Analisar a associação entre fatores sociodemográficos e excesso de peso em participantes do Projeto VIVALEITE. Métodos: Estudo de coorte com dados de 1.039 crianças de famílias de baixa renda do interior do Estado de São Paulo, ingressantes no projeto VIVALEITE com seis meses de idade e peso próximo ao limite superior de adequação, no período de janeiro de 2003 a setembro de 2008. Investigou-se a proporção de crianças que ficam com excesso de peso durante a participação no programa e as associações com as condições sociodemográficas de cada criança (amamentação aos seis meses, sexo e peso ao nascer) e dos respectivos responsáveis (condição conjugal, idade, situação de trabalho e escolaridade). A modelagem foi feita por meio de regressão logística, com as variáveis socioeconômicas em cada idade de pesagem (9 a 23 meses) e regressão logística multinível das variáveis socioeconômicas e o conjunto das idades de pesagem. O processamento foi feito com o pacote estatístico Stata 10.1. Resultados: Conforme análise multinível, a categoria sim da variável aleitamento materno aos seis meses (OR=0,29, p=0,000) e a categoria trabalha da variável situação de trabalho materno (OR=0,36, p=0,012) foram associadas significantemente ao excesso de peso das crianças. As variáveis peso ao nascer, sexo, condição conjugal, idade materna e escolaridade não foram associadas estatisticamente ao excesso de peso. Conclusões: A não amamentação aos seis meses e a condição de não trabalho materno são os fatores sociodemográficos positivamente / Introduction: Previous studies have shown the effectiveness of VIVALEITE Project to gain weight in children under two years old. As the program is effective, it is possible that children who began weighting close to the limit considered appropriate for the age during their participation this weight exceed the limit. Examine for sociodemographic variables associated with overweight may allow the establishment of preventive measures by program managers. Objective: To analyze the association between sociodemographic factors and overweight in participants of VIVALEITE Project. Methods: Cohort study with data from 1,039 infants from low-income families in the state of São Paulo, who were admitted on Vivaleite design with six months of age and weight near the upper limit of adequacy, from January 2003 to September 2008. Investigate the proportion of children who became overweight during participation in the program and associations with sociodemographic conditions of each child (breastfeeding at six months, sex and birth weight) and their guardians (marital status, age, employment status and education). The modeling was performed using logistic regression with socioeconomic variables in each age in the moment by weigh (9-23 months) and multilevel logistic regression of socioeconomic variables and all the ages of weighing. Stata 10.1 program version was used for analysis. Results: As multilevel analysis, the category yes of breastfeeding at six months (OR = 0.29, p = 0.000) and maternal work category (OR = 0.36, p = 0.012) were significantly associated with the overweight in children. The variables birth weight, sex, marital status, maternal age and education were not statistically associated with overweight. Conclusions: The absence of breastfeeding at six months and the condition of maternal unemployment are the sociodemographic factors positively associated with overweight infants participating in the program

Introdução: Estudos anteriores mostraram a efetividade do Projeto VIVALEITE para o ganho de peso de crianças menores de dois anos. Como o programa é efetivo, é possível que crianças ingressantes com peso próximo ao limite considerado adequado para idade o ultrapassem no decorrer de sua participação. Verificar se há variáveis sociodemográficas associadas ao excesso de peso poderá permitir o estabelecimento de medidas preventivas por parte dos gestores do programa. Objetivo: Analisar a associação entre fatores sociodemográficos e excesso de peso em participantes do Projeto VIVALEITE. Métodos: Estudo de coorte com dados de 1.039 crianças de famílias de baixa renda do interior do Estado de São Paulo, ingressantes no projeto VIVALEITE com seis meses de idade e peso próximo ao limite superior de adequação, no período de janeiro de 2003 a setembro de 2008. Investigou-se a proporção de crianças que ficam com excesso de peso durante a participação no programa e as associações com as condições sociodemográficas de cada criança (amamentação aos seis meses, sexo e peso ao nascer) e dos respectivos responsáveis (condição conjugal, idade, situação de trabalho e escolaridade). A modelagem foi feita por meio de regressão logística, com as variáveis socioeconômicas em cada idade de pesagem (9 a 23 meses) e regressão logística multinível das variáveis socioeconômicas e o conjunto das idades de pesagem. O processamento foi feito com o pacote estatístico Stata 10.1. Resultados: Conforme análise multinível, a categoria sim da variável aleitamento materno aos seis meses (OR=0,29, p=0,000) e a categoria trabalha da variável situação de trabalho materno (OR=0,36, p=0,012) foram associadas significantemente ao excesso de peso das crianças. As variáveis peso ao nascer, sexo, condição conjugal, idade materna e escolaridade não foram associadas estatisticamente ao excesso de peso. Conclusões: A não amamentação aos seis meses e a condição de não trabalho materno são os fatores sociodemográficos positivamente / Introduction: Previous studies have shown the effectiveness of VIVALEITE Project to gain weight in children under two years old. As the program is effective, it is possible that children who began weighting close to the limit considered appropriate for the age during their participation this weight exceed the limit. Examine for sociodemographic variables associated with overweight may allow the establishment of preventive measures by program managers. Objective: To analyze the association between sociodemographic factors and overweight in participants of VIVALEITE Project. Methods: Cohort study with data from 1,039 infants from low-income families in the state of São Paulo, who were admitted on Vivaleite design with six months of age and weight near the upper limit of adequacy, from January 2003 to September 2008. Investigate the proportion of children who became overweight during participation in the program and associations with sociodemographic conditions of each child (breastfeeding at six months, sex and birth weight) and their guardians (marital status, age, employment status and education). The modeling was performed using logistic regression with socioeconomic variables in each age in the moment by weigh (9-23 months) and multilevel logistic regression of socioeconomic variables and all the ages of weighing. Stata 10.1 program version was used for analysis. Results: As multilevel analysis, the category yes of breastfeeding at six months (OR = 0.29, p = 0.000) and maternal work category (OR = 0.36, p = 0.012) were significantly associated with the overweight in children. The variables birth weight, sex, marital status, maternal age and education were not statistically associated with overweight. Conclusions: The absence of breastfeeding at six months and the condition of maternal unemployment are the sociodemographic factors positively associated with overweight infants participating in the program

Accurate prediction of mortality is an important component of forest growth and yield prediction systems, yet mortality remains one of the least understood components of the system. Whole-stand and individual-tree mortality models were developed for loblolly pine plantations throughout its geographic range in the United States. The model for predicting stand mortality were developed using stand characteristics and biophysical variables. The models were constructed using two modeling approaches. In the first approach, mortality functions for directly predicting tree number reduction were developed using algebraic difference equation method. In the second approach, a two-step modeling strategy was used where a model predicting the probability of tree death occurring over a period was developed in the first step and a function that estimates the reduction in tree number was developed in the second step. Individual-tree mortality models were developed using multilevel logistic regression and survival analysis techniques. Multilevel data structure inherent in permanent sample plots data i.e. measurement occasions nested within trees (e.g., repeated measurements) and trees nested within plots, is often ignored in modeling tree mortality in forestry applications. Multilevel mixed-effects logistic regression takes into account the full hierarchical structure of the data. Multilevel mixed-effects models gave better predictions than the fixed effects model; however, the model fits and predictions were further improved by taking into account the full hierarchical structure of the data. Semiparametric proportional hazards regression was also used to develop model for individual-tree mortality. Shared frailty model, mixed model extension of Cox proportional hazards model, was used to account for unobserved heterogeneity not explained by the observed covariates in the Cox model. / Ph. D.

This diploma thesis focuses on the so-called "migration crisis" and its impact on public opinion across the European Union (EU) between the years 2014 and 2017. It stems from existing literature that works with the concept of perceived group threat. The main goal is to analyze individual-level and contextual-level factors that played a key role in a certain development of native population's negative attitudes towards migrants and refugees. Such context is represented by the EU member states. An important part of the analysis deals with the relative imporance of contextual-level factors vis-à-vis individual-level determinants. Based on the results of multinomial multilevel logistic regression, the study finds that contextual-level characteristics had a substantial impact on negative attitudes towards immigrants and a large impact on negative attitudes towards refugees. Moreover, the importance of contextual determinants increased in 2015 and 2016, respectively, followed by a decline in the subsequent period. The analyses also revealed that during the "migration crisis" the impact of specific categories of explanatory variables evolved differently. Furthermore, it was shown that educational attainment, preferred social identity and different historical immigration legacies had a considerably...

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