Humans tend to view those with similar characteristics to their own more favorably than those with dissimilar characteristics. Mahajan and Wynn (2012) suggest this phenomenon is rooted in an innate preference for similarity to self and is enhanced by the salience of the similar characteristic(s). This conclusion was based on results from a study conducted by Mahajan and Wynn showing that infants who chose a food prior to choosing a puppet (High Salience condition) preferred the puppet with the same food preference, whereas infants who chose a food after choosing a puppet (Low Salience condition) showed no preference based on a single measure of choice. However, their results may have been affected by factors other than infant preference such as parental bias or side bias. The purpose of the present study was to replicate Mahajan and Wynn's (2012) Low Salience condition and extend it by assigning 20 infants and their parents (10 infants/parent dyads per group) to either (a) a between group manipulation in which infants' food preference was made "salient" to parents (but not infants) in only one group, or (b) a within-subject repeated measures of infants' choices. Results suggested that the manipulation may have been insufficient to assess parental bias; however, more infants (75%) chose a puppet presented on one side more often than a particular puppet (e.g., similar or dissimilar) suggesting infants' choices may be more a product of side bias than puppet preference.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Nas últimas décadas, tem sido observado o aumento da oferta de bebidas com elevado conteúdo calórico e com grandes quantidades de açúcar de rápida absorção. Essas bebidas adoçadas, cujo consumo tem aumentado no Brasil assim como em outras partes do mundo, são consideradas fatores de risco para obesidade e diabetes. O consumo de bebidas adoçadas pode levar ao balanço energético positivo e consequentemente ao ganho de peso. Essa associação pode ser explicada pelo mecanismo regulatório de compensação de calorias líquidas. Compensação calórica ocorre quando há redução no consumo de calorias provenientes de alimentos sólidos para compensar as calorias líquidas adicionadas à refeição ou dieta. No entanto, não há consenso em relação a evidências da compensação calórica, dificultando a elaboração de recomendações sobre essas bebidas em saúde pública. Razões para a falta de consenso incluem a diversidade de desenhos de estudos, experimentos realizados em ambientes controlados e não reais em relação ao consumo de alimentos e bebidas, e estudos com amostras pequenas ou de conveniência. Esta dissertação estudou a associação entre bebidas adoçadas e consumo calórico, verificando se calorias de bebidas adoçadas são compensadas em refeições realizadas em um ambiente pragmático. Os dados de consumo calórico de 34.003 indivíduos, com idade igual ou superior a dez anos, foram obtidos pelo Inquérito Nacional de Alimentação 2008-2009, em todo território nacional. Os participantes completaram dois registros alimentares, em dias não consecutivos da mesma semana. Foram selecionadas as refeições dos períodos café da manhã, almoço e jantar de cada indivíduo em cada um dos dias. Para cada refeição, foi calculado o valor calórico de alimentos e de bebidas adoçadas consumidos. Para testar a compensação calórica, um modelo de regressão linear multinível com efeitos mistos foi ajustado para analisar cada período. A variável reposta utilizada foi consumo calórico proveniente de alimentos e a variável explicativa foi consumo calórico de bebida adoçada na refeição. Os efeitos intra-indivíduo da bebida adoçada no consumo calórico foram estimados e interpretados. Esses efeitos são considerados não-enviesados pois são controlados pelas características constantes dos indivíduos, tendo assim o indivíduo atuando como seu próprio controle na análise. Covariadas incluídas no modelo foram variáveis da refeição: local, dia da semana, horário, consumo calórico na refeição anterior e intervalo de tempo desde a última refeição; e do indivíduo: sexo, faixa etária, categoria de Índice de Massa Corpórea e quartos de renda per capita. Efeitos aleatórios dos indivíduos e dos domicílios foram incluídos no modelo para melhor estimar a estrutura de erros de dados correlacionados. A compensação calórica foi de 42% para o café da manhã, não houve compensação no almoço e para o jantar, compensação variou de 0 a 22%, tendo interação com quartos de renda per capita. A conclusão desta dissertação é que as bebidas adoçadas não são completamente compensadas em refeições realizadas em ambiente pragmático. Assim, a redução do consumo de bebidas adoçadas em refeições pode ajudar a diminuir o consumo calórico excessivo e levar a um melhor controle do peso em indivíduos. / Over the past decades, an increase has been observed in the availability of beverages that are high in energy and rapidly absorbed sugar. These sugar-sweetened beverages, whose consumption has increased in Brazil as well as in other parts of the world, are considered risk factors for obesity and diabetes. The consumption of sugar-sweetened beverages can lead to positive energy balance and consequently to weight gain. This association can be explained by the compensatory regulation of liquid calories. Caloric compensation occurs when there is a reduction in the caloric consumption derived from solid food to compensate for the liquid calories added to the meal or diet. However, the evidence for a public health policy recommendation remains inconclusive. Among reasons for the lack of consensus are the diversity of study designs, experiments conducted in controlled environments that do not reflect the natural consumption of food and beverages, and the use of small or convenient samples. This dissertation studied the association between sugar-sweetened beverages and energy intake, analyzing if calories of sugar-sweetened beverages are compensated during meals in a pragmatic environment. The dietary data was obtained from the National Dietary Survey 2008-2009, which collected information on food consumption from 34,003 individuals, aged 10 years and older, from within the entire national territory. The participants completed two food records over non-consecutive days of the same week. The meals breakfast, lunch and dinner were identified for each individual on each of the days. For each meal, energy intake from food and sugar-sweetened beverages was measured. To test for caloric compensation, a multi-level mixed-effects linear regression model was adjusted for each meal type. The outcome variable was food energy intake and the explicative variable was energy from sugar-sweetened beverages during the meal. The intra-individual effects of the sugar-sweetened beverages on food energy intake were estimated and interpreted. These effects are considered unbiased because they are controlled by all stable characteristics of the subject, and thus the individual acts as his/her own control in the analysis. Covariates included in the model were the meal variables, such as location, day of the week, time of day, energy intake in the previous meal and time interval since the previous meal. And variables of the subject included sex, age group, BMI category and quartiles of per capita income. Random effects of subjects and of households were included in the model to better estimate the structure of errors within the correlated data. The caloric compensation was 42% for breakfast; there was no compensation for lunch; and for dinner, compensation ranged between 0 and 22%, with significant interaction with quartiles of per capita income. The conclusion of this dissertation is that sugar-sweetened beverages are not completely compensated in meals that take place in a pragmatic environment. Therefore, a reduction in the consumption of sugar-sweetened beverages in meals may help reduce excessive caloric consumption, leading to better weight control.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Nas últimas décadas, tem sido observado o aumento da oferta de bebidas com elevado conteúdo calórico e com grandes quantidades de açúcar de rápida absorção. Essas bebidas adoçadas, cujo consumo tem aumentado no Brasil assim como em outras partes do mundo, são consideradas fatores de risco para obesidade e diabetes. O consumo de bebidas adoçadas pode levar ao balanço energético positivo e consequentemente ao ganho de peso. Essa associação pode ser explicada pelo mecanismo regulatório de compensação de calorias líquidas. Compensação calórica ocorre quando há redução no consumo de calorias provenientes de alimentos sólidos para compensar as calorias líquidas adicionadas à refeição ou dieta. No entanto, não há consenso em relação a evidências da compensação calórica, dificultando a elaboração de recomendações sobre essas bebidas em saúde pública. Razões para a falta de consenso incluem a diversidade de desenhos de estudos, experimentos realizados em ambientes controlados e não reais em relação ao consumo de alimentos e bebidas, e estudos com amostras pequenas ou de conveniência. Esta dissertação estudou a associação entre bebidas adoçadas e consumo calórico, verificando se calorias de bebidas adoçadas são compensadas em refeições realizadas em um ambiente pragmático. Os dados de consumo calórico de 34.003 indivíduos, com idade igual ou superior a dez anos, foram obtidos pelo Inquérito Nacional de Alimentação 2008-2009, em todo território nacional. Os participantes completaram dois registros alimentares, em dias não consecutivos da mesma semana. Foram selecionadas as refeições dos períodos café da manhã, almoço e jantar de cada indivíduo em cada um dos dias. Para cada refeição, foi calculado o valor calórico de alimentos e de bebidas adoçadas consumidos. Para testar a compensação calórica, um modelo de regressão linear multinível com efeitos mistos foi ajustado para analisar cada período. A variável reposta utilizada foi consumo calórico proveniente de alimentos e a variável explicativa foi consumo calórico de bebida adoçada na refeição. Os efeitos intra-indivíduo da bebida adoçada no consumo calórico foram estimados e interpretados. Esses efeitos são considerados não-enviesados pois são controlados pelas características constantes dos indivíduos, tendo assim o indivíduo atuando como seu próprio controle na análise. Covariadas incluídas no modelo foram variáveis da refeição: local, dia da semana, horário, consumo calórico na refeição anterior e intervalo de tempo desde a última refeição; e do indivíduo: sexo, faixa etária, categoria de Índice de Massa Corpórea e quartos de renda per capita. Efeitos aleatórios dos indivíduos e dos domicílios foram incluídos no modelo para melhor estimar a estrutura de erros de dados correlacionados. A compensação calórica foi de 42% para o café da manhã, não houve compensação no almoço e para o jantar, compensação variou de 0 a 22%, tendo interação com quartos de renda per capita. A conclusão desta dissertação é que as bebidas adoçadas não são completamente compensadas em refeições realizadas em ambiente pragmático. Assim, a redução do consumo de bebidas adoçadas em refeições pode ajudar a diminuir o consumo calórico excessivo e levar a um melhor controle do peso em indivíduos. / Over the past decades, an increase has been observed in the availability of beverages that are high in energy and rapidly absorbed sugar. These sugar-sweetened beverages, whose consumption has increased in Brazil as well as in other parts of the world, are considered risk factors for obesity and diabetes. The consumption of sugar-sweetened beverages can lead to positive energy balance and consequently to weight gain. This association can be explained by the compensatory regulation of liquid calories. Caloric compensation occurs when there is a reduction in the caloric consumption derived from solid food to compensate for the liquid calories added to the meal or diet. However, the evidence for a public health policy recommendation remains inconclusive. Among reasons for the lack of consensus are the diversity of study designs, experiments conducted in controlled environments that do not reflect the natural consumption of food and beverages, and the use of small or convenient samples. This dissertation studied the association between sugar-sweetened beverages and energy intake, analyzing if calories of sugar-sweetened beverages are compensated during meals in a pragmatic environment. The dietary data was obtained from the National Dietary Survey 2008-2009, which collected information on food consumption from 34,003 individuals, aged 10 years and older, from within the entire national territory. The participants completed two food records over non-consecutive days of the same week. The meals breakfast, lunch and dinner were identified for each individual on each of the days. For each meal, energy intake from food and sugar-sweetened beverages was measured. To test for caloric compensation, a multi-level mixed-effects linear regression model was adjusted for each meal type. The outcome variable was food energy intake and the explicative variable was energy from sugar-sweetened beverages during the meal. The intra-individual effects of the sugar-sweetened beverages on food energy intake were estimated and interpreted. These effects are considered unbiased because they are controlled by all stable characteristics of the subject, and thus the individual acts as his/her own control in the analysis. Covariates included in the model were the meal variables, such as location, day of the week, time of day, energy intake in the previous meal and time interval since the previous meal. And variables of the subject included sex, age group, BMI category and quartiles of per capita income. Random effects of subjects and of households were included in the model to better estimate the structure of errors within the correlated data. The caloric compensation was 42% for breakfast; there was no compensation for lunch; and for dinner, compensation ranged between 0 and 22%, with significant interaction with quartiles of per capita income. The conclusion of this dissertation is that sugar-sweetened beverages are not completely compensated in meals that take place in a pragmatic environment. Therefore, a reduction in the consumption of sugar-sweetened beverages in meals may help reduce excessive caloric consumption, leading to better weight control.

Foundational research on infant social evaluations (e.g., Hamlin et al., 2007; Hamlin et al., 2011; Hamlin & Wynn, 2011) has been cited over 2,500 times and infant researchers suggest these data show infants have an unlearned preference for prosocial others. However, several failed replications have been published, which might be attributable to the type of research methods used to investigate this question. A single measure of the dependent variable is ubiquitous among these studies; within-subject repeated measures are rarely used. In the current study, we adapted methods used by Hamlin and Wynn (2011) to a video-only format, due to COVID-19 restrictions; we extended their methods by including four puppet shows and four corresponding puppet choices to assess for choice stability within and across participants. Six infants were assessed; all but one infant failed to make all four choices and three sessions had to be terminated early due to fussiness. Among the four infants who made at least two choices, no infant showed a robust preference for the helper puppet, two infants chose a puppet on the same side at least three times, and one infant chose the hinderer on three of four opportunities. Our data suggest that a completely virtual method might not be feasible for assessing infants’ choices between two puppets presented on a screen. Suggestions for addressing the limitations of the current study and directions for future research are described.

Systematic manipulations of the order in which questions are presented in hypothetical discounting tasks have shown that individual responses vary as a result of these manipulations. For example, Robles and Vargas (2007, 2008) and Robles, Vargas, and Bejarano (2009) demonstrated that individual discounting rates systematically change if questions are presented in a random, ascending, or descending order. The purpose of this study was to examine if specific sequential manipulations affected individual k values when using the Kirby, Petry, and Bickel (1999) 27-item Monetary Choice Questionnaire (MCQ). In a single session, participants (undergraduate students, N = 80), answered two MCQs. One of the MCQs was the standard Kirby et al. (1999) MCQ and the other was the MCQ with the question sequence altered systematically. Within-subject results suggest that individual k values are consistent when comparing k values from the two MCQs completed by each individual. In most cases, individual k values between MCQs did not vary substantially. Additionally, there was a statistically significant correlation between both MCQ administrations for each group. Results from this study indicate that k values obtained using the MCQ are reliable when question sequence is altered.

<p dir="ltr">This dissertation addresses three progressively fundamental problems for functional data analysis: (1) To do efficient inference for the functional mean model accounting for within-subject correlation, we propose the refined and bias-corrected empirical likelihood method. (2) To identify functional subjects potentially from different populations, we propose the dominant-set based unsupervised clustering method using the similarity matrix. (3) To learn the similarity matrix from various similarity metrics for functional data clustering, we propose the modularity guided and dominant-set based semi-supervised clustering method.</p><p dir="ltr">In the first problem, the empirical likelihood method is utilized to do inference for the mean function of functional data by constructing the refined and bias-corrected estimating equation. The proposed estimating equation not only improves efficiency but also enables practically feasible empirical likelihood inference by properly incorporating within-subject correlation, which has not been achieved by previous studies.</p><p dir="ltr">In the second problem, the dominant-set based unsupervised clustering method is proposed to maximize the within-cluster similarity and applied to functional data with a flexible choice of similarity measures between curves. The proposed unsupervised clustering method is a hierarchical bipartition procedure under the penalized optimization framework with the tuning parameter selected by maximizing the clustering criterion called modularity of the resulting two clusters, which is inspired by the concept of dominant set in graph theory and solved by replicator dynamics in game theory. The advantage offered by this approach is not only robust to imbalanced sizes of groups but also to outliers, which overcomes the limitation of many existing clustering methods.</p><p dir="ltr">In the third problem, the metric-based semi-supervised clustering method is proposed with similarity metric learned by modularity maximization and followed by the above proposed dominant-set based clustering procedure. Under semi-supervised setting where some clustering memberships are known, the goal is to determine the best linear combination of candidate similarity metrics as the final metric to enhance the clustering performance. Besides the global metric-based algorithm, another algorithm is also proposed to learn individual metrics for each cluster, which permits overlapping membership for the clustering. This is innovatively different from many existing methods. This method is superiorly applicable to functional data with various similarity metrics between functional curves, while also exhibiting robustness to imbalanced sizes of groups, which are intrinsic to the dominant-set based clustering approach.</p><p dir="ltr">In all three problems, the advantages of the proposed methods are demonstrated through extensive empirical investigations using simulations as well as real data applications.</p>

Les phénols et les phtalates incluent des composés très largement utilisés dans des produits de la vie quotidienne. Une grande partie de la population générale y est donc largement exposée. Ces composés sont suspectés d’être des perturbateurs endocriniens et des effets sur la santé chez l’Homme ont été rapportés, notamment après une exposition périnatale. Les études épidémiologiques sur les effets sur la santé humaine reposent généralement sur un faible nombre de biospécimens pour estimer l’exposition. Cependant, la variabilité intra-individuelle des phénols et des phtalates est potentiellement forte, ce qui peut entraîner une mauvaise classification de l’exposition dans les études sur les effets des phénols et des phtalates et limite leurs conclusions. La variabilité intra-individuelle des phénols et des phtalates au cours de la grossesse n’est pas très bien caractérisée à l’heure actuelle.L’objectif de cette thèse est d’explorer l’exposition aux phénols et aux phtalates et plus précisément : 1) d’étudier les associations entre une telle exposition pendant la grossesse et la santé respiratoire de l’enfant au cours de ses premières années de vie ; 2) de caractériser la variabilité temporelle intra-individuelle de ces composés au cours de la grossesse ; et 3) d’évaluer l’efficacité d’une approche basée sur le pooling intra-sujet d’un nombre réduit d’échantillons journaliers pour estimer l’exposition.Les associations entre l’exposition aux phénols et phtalates et la santé respiratoire reposent sur n = 587 couples mèresenfants de la cohorte prospective française EDEN. Les développements sur l’estimation de l’exposition au cours de la grossesse s’appuient sur n = 16 femmes enceintes ayant participé à l’étude de faisabilité de la cohorte SEPAGES.Les travaux de cette thèse quantifient la variabilité intra-individuelle des concentrations urinaires des biomarqueurs d’exposition aux phénols et des phtalates au cours de la grossesse pour des échelles de temps variées (du jour à plusieurs mois). Ils confirment empiriquement que cette variabilité peut biaiser fortement les fonctions doses-réponses dans les études épidémiologiques explorant les effets de l’exposition fœtale à ces composés chez l’Homme.Les résultats de cette thèse enrichissent la littérature émergente sur les effets des expositions précoces aux phénols et phtalates sur la santé respiratoire de l’Homme. Cependant, notre étude ainsi que la plupart des recherches précédentes sont potentiellement limitées par les problématiques liées à la mesure de l’exposition. Ce travail souligne l’importance de stratégies d’échantillonnage des biomarqueurs d’exposition plus élaborées pour l’étude de ces composés dans de futures études épidémiologiques. Ces résultats sont aussi pertinents en dehors du contexte de la grossesse et pour d’autres composés non-persistants. De nouvelles approches, telles que le pooling répété pour chaque sujet d’un petit nombre de biospécimens journaliers, validé dans cette thèse, sont nécessaires pour caractériser efficacement l’impact des composés non-persistants sur la santé de l’Homme. / Phenols and phthalates include chemicals widely used in daily-life products, resulting in ubiquitous exposure of the general population. There is growing concern regarding the effects on human health of these compounds, suspected to be endocrine disruptors, particularly during early life. Epidemiological research on the health effects of phenols and phthalates in offspring generally rely on a few biospecimens to assess exposure. These studies are limited by the possibly strong within-subject variability, which may result in exposure misclassification. The within-subject variability in the context of pregnancy and its possible impact on dose-response functions are poorly characterized.The aim of this thesis was to study the exposure to several phenols and phthalates during pregnancy by: 1) investigating the possible associations between this exposure and respiratory outcomes in childhood; 2) characterizing the temporal within-subject variability of these compounds during pregnancy; and finally 3) studying the efficiency of a within-subject pooling approach using a small number of daily biospecimens for exposure assessment.Associations between exposure to phenols and phthalates and respiratory health relied on n = 587 mother-child pairs from the French EDEN prospective cohort. Developments about the assessment of exposure during pregnancy relied on n = 16 pregnant participants of the SEPAGES-feasibility study who had collected all their urine samples for three weeks.This work quantified the within-subject variability of phenol and phthalate biomarker concentrations during pregnancy over various time scales (day to months), and confirmed empirically that this variability is likely to strongly bias the doseresponse functions in human-based epidemiological studies exploring the effects of gestational exposure to these chemicals.This thesis adds to the emerging literature on respiratory health impacts of early-life exposure to several phenols and phthalates. However, as for most studies on the human health effects of phenol and phthalate exposure, it is potentially challenged by this exposure assessment issue. Thus, this work emphasizes the relevance of more elaborate sampling strategies for exposure biomarkers in future epidemiological studies. These results have relevance for studies outside the context of pregnancy, and also for other nonpersistent compounds. New designs, such as the within-subject pooling of biospecimens validated in this study, are needed so as to efficiently characterize the health impact of nonpersistent chemicals.

In longitudinal studies, data collected within a subject or cluster are somewhat correlated by their very nature and special cares are needed to account for such correlation in the analysis of data. Under the framework of longitudinal studies, three topics are being discussed in this thesis. In chapter 2, the joint modelling of multivariate longitudinal process consisting of different types of outcomes are discussed. In the large cohort study of UK north Stafforshire osteoarthritis project, longitudinal trivariate outcomes of continuous, binary and ordinary data are observed at baseline, year 3 and year 6. Instead of analysing each process separately, joint modelling is proposed for the trivariate outcomes to account for the inherent association by introducing random effects and the covariance matrix G. The influence of covariance matrix G on statistical inference of fixed-effects parameters has been investigated within the Bayesian framework. The study shows that by joint modelling the multivariate longitudinal process, it can reduce the bias and provide with more reliable results than it does by modelling each process separately. Together with the longitudinal measurements taken intermittently, a counting process of events in time is often being observed as well during a longitudinal study. It is of interest to investigate the relationship between time to event and longitudinal process, on the other hand, measurements taken for the longitudinal process may be potentially truncated by the terminated events, such as death. Thus, it may be crucial to jointly model the survival and longitudinal data. It is popular to propose linear mixed-effects models for the longitudinal process of continuous outcomes and Cox regression model for survival data to characterize the relationship between time to event and longitudinal process, and some standard assumptions have been made. In chapter 3, we try to investigate the influence on statistical inference for survival data when the assumption of mutual independence on random error of linear mixed-effects models of longitudinal process has been violated. And the study is conducted by utilising conditional score estimation approach, which provides with robust estimators and shares computational advantage. Generalised sufficient statistic of random effects is proposed to account for the correlation remaining among the random error, which is characterized by the data-driven method of modified Cholesky decomposition. The simulation study shows that, by doing so, it can provide with nearly unbiased estimation and efficient statistical inference as well. In chapter 4, it is trying to account for both the current and past information of longitudinal process into the survival models of joint modelling. In the last 15 to 20 years, it has been popular or even standard to assume that longitudinal process affects the counting process of events in time only through the current value, which, however, is not necessary to be true all the time, as recognised by the investigators in more recent studies. An integral over the trajectory of longitudinal process, along with a weighted curve, is proposed to account for both the current and past information to improve inference and reduce the under estimation of effects of longitudinal process on the risk hazards. A plausible approach of statistical inference for the proposed models has been proposed in the chapter, along with real data analysis and simulation study.