A thesis submitted to the Faculty of Health Sciences, University of Witwatersrand, Johannesburg, in fulfilment of the requirements for the Degree of Doctor of Philosophy in the branch of Medicine: Diagnostic Radiology Johannesburg, 2017. / Introduction: Pneumonia is among the leading infectious causes of morbidity and mortality in children under 5 years globally. The chest X-ray remains the most readily available and most common imaging modality for the assessment of childhood pneumonia. Chest X-ray quality assurance is important to maintain high image quality, allowing for more accurate diagnosis. Chest X-ray patterns in a high HIV prevalence setting in children hospitalized with pneumonia in the era of bacterial conjugate vaccines has not been described. Furthermore the association between chest X-ray findings and microbiological etiology using novel models is important. Standardization of chest X-ray interpretation is important to allow comparison of research findings between studies and has been proposed by the World Health Organisation (WHO) as a measure of bacterial vaccine efficacy (VE). The role of Computer Aided Diagnosis (CAD) for chest X-ray interpretation is important, especially in countries with limited radiologists. Objectives: In this thesis we investigated the quality of chest X-rays and the impact of quality assurance activities in the Pneumonia Etiology Research for Child Health (PERCH) study, from 9 sites in 7 countries (Bangladesh, the Gambia, Kenya, Mali, South Africa, Thailand and Zambia), by quantifying radiographic errors through use of a customized quality assessment form. Within the context of the PERCH South African site, we compared chest X-ray patterns in HIV-unexposed, HIV- exposed-uninfected (HEU) and HIV-infected children hospitalized with WHO-defined severe or very severe community acquired pneumonia. Further, we evaluated the association of chest X-ray patterns with clinical parameters and its association with the PERCH Quantitative Analysis (PQA) model predicted probability of infection by a class or specific pathogens. Lastly, we evaluated the utility of CAD for identifying chest X-ray primary end-point pneumonia (CXR-PEP) versus non CXR-PEP compared to a consensus human interpretation as a reference standard. Results: A total of 747 chest X-rays in 9 PERCH sites had chest X-ray quality assessment. Collimation performed the worse of the 6 parameters, with 5 out of the 9 sites being graded sub-optimally for this. Three of the 9 sites showed a significant improvement in chest X-ray quality using a test for trend analysis. At the South African PERCH site, 920 cases were enrolled over two years, including 858 children with interpretable chest X-rays. The commonest finding was CXR-PEP, prevalent among 38% HIV-unexposed children, 33% HEU children and 60% of HIV-infected children, which was consistent between different age categories. CXR-PEP was twice as common in HIV-infected (OR 2.5; 95% CI 1.6-3.8) compared with these HIV-unexposed children. Clinical and laboratory features independently associated with CXR-PEP included the presence of severe malnutrition, fever and CRP > 40mg/dL. CXR-PEP was associated with the composite outcome of mechanical ventilation or death. However there was no single clinical or laboratory parameter that had both high sensitivity and specificity to discriminate between CXR-PEP from non CXR-PEP cases. HIV-unexposed children with a PQA model probability index > 0.5 for bacterial etiology had 2-fold greater odds (95% CI 1.1-4.1) for CXR-PEP compared to non CXR-PEP, and similarly HIV-unexposed children with microbiologically confirmed pneumococcal pneumonia (MCPP) had 3-fold greater odds (95% CI 1.3-6.7) of CXR-PEP. HIV-infected children with a PQA model probability index > 0.5 for respiratory viral etiology and PQA model probability index > 0.5 for Pneumocystis jiroveci etiology trended to have a greater odds for CXR-PEP vs non CXR-PEP. Using CAD4WHOKids for the 858 interpretable chest X-rays, for CXR-PEP versus non CXR-PEP, CAD4WHOKids had a sensitivity of 76%, specificity of 80% and area under the ROC curve of 0.850 (95% CI 0.823-0.876) compared to the radiologist consensus reading. Conclusion: Chest X-ray quality, in particular collimation was suboptimal in 7 resource limited countries, in children hospitalized for WHO defined severe or very severe pneumonia. CXR-PEP remains the most common chest X-ray abnormality in HIV-unexposed, HEU and HIV-infected children under 5 years of age hospitalized for WHO-defined severe or very severe pneumonia, even in the era of routine HiB and PCV immunization. Our findings support the literature that CXR-PEP is of limited use in HIV-infected children as an outcome measure in bacterial VE studies, due to opportunistic infections like Pneumocystis jiroveci pneumonia and respiratory viral infections contributing to CXR-PEP. CAD is promising as a diagnostic tool for identifying WHO defined CXR-PEP in bacterial VE trials and pneumonia epidemiological studies. / MT2017

Este estudo teve como objeto, crianças e adolescentes com excesso de peso (20 do sexo feminino, 41 do masculino) e seus 61 cuidadores (55 do sexo feminino, 6 do masculino), usuários do Centro de Saúde Escola de peso e seus cuidadores, usuários do Centro de Saúde Escola Jaraguá em Uberlândia-MG. Constitui-se como objetivo, investigar características alimentares destes usuários, como uma contribuição ao estudo da obesidade nesta população. O método adotado foi o descritivo, por meio de uma amostra de conveniência. O instrumento utilizado foi um questionário fechado composto de dez partes. O armazenamento de dados foi feito no programa “Epidate". A análise dos dados foi feita pelo programa estatístico “Epinfo 6.0" e pelo “Excel". Foram feitas correlações de Spearman, Pearson, e Contingência para verificar associação de variáveis entre os cuidadores e as crianças e adolescentes com excesso de peso. Os resultados desta investigação indicam que apesar das crianças e adolescentes e suas famílias fazerem pelo menos as refeições principais, e terem horário determinado para fazê-las, há erro alimentar (excesso de carboidratos e gorduras, alimentos com alta densidade calórica principalmente na colação, lanche e ceia). O sedentarismo e associações de comportamentos como hábito de assistir televisão (principalmente na hora do almoço e jantar) entre cuidadores e crianças e adolescentes, também ficou evidente, o que pode indicar influência de hábitos familiares. Existem questões a serem respondidas, como a relação entre aleitamento e excesso de peso que na literatura aparece como fator protetor e no presente estudo não parece ter sido. São necessários estudos mais aprofundados a fim de entender melhor as necessidades e problemas dessas crianças e adolescentes com excesso de peso e seus cuidadores. / This study had as object, children and adolescents (20 girls and 41 boys) with overweight of its 61 take-careers, (55 women, 6 mens), users of the Center of Health Jaraguá School in Uberlândia-MG. One consists as objective, to investigate alimentary characteristics of these users, as a contribution to the study of the obesidade in this population. The adopted methodology was descriptive, by means of a convenience sample. The used instrument was made in the “Epidate" program. The analysis of the data was made by the statistical program “Epinfo 6.0" and by “Excel". Correlations of Spearman, Pearson had been made, and Contingency to verify association of variable between the take-careers and the children and adolescents with overweight . The results of this inquiry indicate that despite the children and adolescents and its families to make at least the main meals, and to have determined schedule to make them, it has alimentary error (excess of carboidratos and fats, foods with high calorie density mainly in the light meal, snack and supper). The sedentarism and associations of behaviors as habit to attend to television (mainly in the hour of the lunch and supper) between take-careers and children and adolescents, also were evident, what it can indicate influence of familiar habits. Questions exist to be answered, as the relation between breathing and excess of weight that in literature appear as protective factor and in the present study do not seem to have been. They are necessary studies more deepened in order to better understand the necessities and problems of this population with excess of weight and its take careers.

Resumo: Neste trabalho de pesquisa abordo questões referentes à brincadeira e ao desenvolvimento cultural da criança de seis anos, na ótica da Teoria Histórico-Cultural e busco compreender, brevemente, as relações existentes entre o faz-de-conta e o desenvolvimento da representação simbólica da consciência, essencial para a apropriação da leitura e da escrita. A hipótese norteadora das investigações é a de que, embora a aprendizagem da leitura e da escrita esteja no foco das expectativas dos pais e professores, esta se constitui num desafio ao qual a grande maioria das crianças não pode corresponder, porque requer a apropriação de capacidades humanas que formam as bases orientadoras de novas aprendizagens na idade escolar, de modo particular, a apropriação da leitura e da escrita. Essas bases orientadoras se formam na infância por meio das atividades promotoras de desenvolvimento infantil (atividades plásticas e de construção) e por meio do brincar que se constitui na atividade principal desse período. Na busca pela compreensão desse objeto de estudo, inseri o brincar na rotina de uma turma com crianças de seis anos de uma escola pública estadual. Realizei, então, uma pesquisa qualitativa do tipo Estudo de Caso que se fundamentou nos estudos de Vigotski e colaboradores e teve como instrumentos de coleta de dados entrevistas com as crianças, digressões das mesmas e a observação universal. A teoria microgenética de origem Vigotskiana e análise do conteúdo foram os instrumentos de análise de dados. Os dados foram coletados a partir de um trabalho pedagógico intencionalmente planejado para provocar o processo de aprendizagem das funções necessárias à apropriação da leitura e da escrita, bem como da observação das atitudes das crianças denotativas dessas aprendizagens. / Abstract: In this report I approach questions about playing and the cultural development of a six years old child, In the optical of the historical cultural focus. I intend to understand the relationship between the make-believe and the development of the symbolic representation of the conscience essential to the process of reading and writing. The main hypothesis of investigating is that although the learning of reading and writing be the focus of the expectative of parents and professors, this is a challenge that most of the kids can not correspond because it requests the appropriation of human capacities that form the guiding base of new learnings in the school age, in a particular way, the appropriation of reading and writing. This guiding base forms in the infancy age through playing, which is the main activity of this period. I have done a qualitativ research of the type Case Study with six-years-old children of a state public school to understand this study object. This research methodology was based in the Vigotski studies and it had as instrumental of data collects the interviewing with children, digressions and universal observations. The microgenetic theory of Vigotskian origin and the analysis of the contents were the instruments of data analysis.The collected data were used to accomplish a pedagogic work intentionally planned to provoke the process of learning of the necessary function to the appropriation of reading and writing as well to possibility the observation of the children acts denotative of these learnings. / Orientador: Dagoberto Buim Arena / Coorientador: Suely Amaral Mello / Banca: Cyntia Graziella Guizelim Girotto / Banca: José Milton de Lima / Mestre

Este estudo teve como objeto, crianças e adolescentes com excesso de peso (20 do sexo feminino, 41 do masculino) e seus 61 cuidadores (55 do sexo feminino, 6 do masculino), usuários do Centro de Saúde Escola de peso e seus cuidadores, usuários do Centro de Saúde Escola Jaraguá em Uberlândia-MG. Constitui-se como objetivo, investigar características alimentares destes usuários, como uma contribuição ao estudo da obesidade nesta população. O método adotado foi o descritivo, por meio de uma amostra de conveniência. O instrumento utilizado foi um questionário fechado composto de dez partes. O armazenamento de dados foi feito no programa “Epidate”. A análise dos dados foi feita pelo programa estatístico “Epinfo 6.0” e pelo “Excel”. Foram feitas correlações de Spearman, Pearson, e Contingência para verificar associação de variáveis entre os cuidadores e as crianças e adolescentes com excesso de peso. Os resultados desta investigação indicam que apesar das crianças e adolescentes e suas famílias fazerem pelo menos as refeições principais, e terem horário determinado para fazê-las, há erro alimentar (excesso de carboidratos e gorduras, alimentos com alta densidade calórica principalmente na colação, lanche e ceia). O sedentarismo e associações de comportamentos como hábito de assistir televisão (principalmente na hora do almoço e jantar) entre cuidadores e crianças e adolescentes, também ficou evidente, o que pode indicar influência de hábitos familiares. Existem questões a serem respondidas, como a relação entre aleitamento e excesso de peso que na literatura aparece como fator protetor e no presente estudo não parece ter sido. São necessários estudos mais aprofundados a fim de entender melhor as necessidades e problemas dessas crianças e adolescentes com excesso de peso e seus cuidadores. / This study had as object, children and adolescents (20 girls and 41 boys) with overweight of its 61 take-careers, (55 women, 6 mens), users of the Center of Health Jaraguá School in Uberlândia-MG. One consists as objective, to investigate alimentary characteristics of these users, as a contribution to the study of the obesidade in this population. The adopted methodology was descriptive, by means of a convenience sample. The used instrument was made in the “Epidate” program. The analysis of the data was made by the statistical program “Epinfo 6.0” and by “Excel”. Correlations of Spearman, Pearson had been made, and Contingency to verify association of variable between the take-careers and the children and adolescents with overweight . The results of this inquiry indicate that despite the children and adolescents and its families to make at least the main meals, and to have determined schedule to make them, it has alimentary error (excess of carboidratos and fats, foods with high calorie density mainly in the light meal, snack and supper). The sedentarism and associations of behaviors as habit to attend to television (mainly in the hour of the lunch and supper) between take-careers and children and adolescents, also were evident, what it can indicate influence of familiar habits. Questions exist to be answered, as the relation between breathing and excess of weight that in literature appear as protective factor and in the present study do not seem to have been. They are necessary studies more deepened in order to better understand the necessities and problems of this population with excess of weight and its take careers.

Thesis (D.Sc.)--University of the Witwatersrand, Faculty of Health Sciences, 2012.

abstract: The ability to self-regulate is arguably the single most important skill a child develops early in life. Self-regulation skills are consistently linked to indices of health, success, and wellbeing. The predominating perspective in self-regulation developmental research has emphasized the role of the early caregiving environment, specifically maternal characteristics and behavior, in shaping infants’ emerging regulatory skills. Using two complementary studies, this dissertation draws from a longitudinal sample of 322 low-income, Mexican American mother-infant dyads to better understand mothers’ and infants’ unique roles in contributing to emerging infant regulatory processes. The first study explores the unique contributions of intrinsic (i.e., infant gaze) and extrinsic (i.e., maternal gaze) factors in understanding infant dysregulated emotion and behavior during mother-infant interactions. Using actor partner interdependent models (APIMs), the role of infant and maternal gaze in understanding infant dysregulation were examined longitudinally across three mother-infant interaction tasks (i.e., soothing, teaching, and peekaboo), as well as within task. The expected relations among gaze and dysregulation did not emerge in the longitudinal model; however, differential patterns of associations emerged by task. Findings are discussed within the intersection of risk, culture, and the dyadic interaction context. The second study connects patterns of specific maternal behaviors (i.e., acknowledging, gaze, vocal appropriateness, appropriate range of affect, consistency of style, resourcefulness, and touch) associated with maternal sensitivity to infant cortisol reactivity and recovery. Latent profile analysis (LPA) revealed four distinct combinations of maternal sensitivity behaviors. One pattern emerged as a risk profile—differentiated by higher maternal stress—and was associated with significantly more infant cortisol recovery compared to other profiles. Both studies offer a more nuanced understanding of the respective roles of infant and maternal factors in the development of self-regulation. Further explication of developmental processes involved in early regulatory functioning has implications for advancing both scientific knowledge and improved targeting of prevention and early intervention efforts to promote optimal child outcomes, particularly in populations that at increased risk for developmental psychopathology. / Dissertation/Thesis / Doctoral Dissertation Family and Human Development 2019

Previous natural observations have found a robust correlation between infants’ spontaneous gesture production and vocabulary development: the onset and frequency of infants’ pointing gestures are significantly correlated to their subsequent vocabulary size (Colonnesi, Stams, Koster, & Noom, 2010). The present study first examined the correlations between pointing and vocabulary size in an experimental setting, and then experimentally manipulated responses to pointing, to investigate the role of pointing in infants’ forming word-object associations. In the first experiment, we elicited 12- to 24-month old infants’ pointing gestures to 8 familiar and 8 novel objects. Their vocabulary was assessed by the MacArthur Communicative Development Inventory (MCDI): Words and Gestures. Results showed that 12-16 month old infants’ receptive vocabulary was positively correlated to infants’ spontaneous pointing. This correlation, however, was not significant in 19-24 month old infants. This experiment thus generalizes the previous naturalistic observation findings to an experimental setting, and shows a developmental change in the relation between pointing and receptive vocabulary. Together with prior studies, it suggests a possible positive social feedback loop of pointing and language skills in infants younger than 18 months old: the bigger vocabulary size infants have, the more likely they point, the more words they hear, and then the faster they develop their vocabulary. In the second experiment, we tested whether 16-month-old infants’ pointing gestures facilitate infants’ word learning in the moment. Infants were randomly assigned to one of three conditions: the experimenter labeled an unfamiliar object with a novel name 1) immediately after the infant pointed to it (the point contingent condition); 2) when the infant looked at it; or 3) at a schedule predetermined by a vocabulary-matched infant in the point contingent condition. After hearing the objects’ names, infants were presented with a word learning test. Results showed that infants successfully selected the correct referent above chance level only in the point contingent condition, and their performance was significantly better in the point contingent condition than the other two conditions. Therefore, only words that were provided contingently after pointing were learned. Taken together, these two studies further our understanding of the correlation between early gesture and vocabulary development and suggest that pointing plays a role in early word learning.

Parents play a critical role in their infants’ social and emotional development (Zeifman, 2003). High parental sensitivity contributes to greater infant attachment security (De Wolff & van IJzendoorn, 1997), as well as better compliance later in life (van Berkel et al., 2015). Personality influences how parents respond to their infants, such that parents higher in neuroticism are more controlling and less stimulating (Clark, Kochanska, & Ready, 2000), and less responsive (Kochanska, Friesenborg, Lange, & Martel, 2004). However, previous studies have found mixed results with parent extraversion. Some studies found that high parental extraversion could lead to more parent responsiveness (Clark et al., 2000), whereas others have found that these parents are more controlling (Metsepelto & Pulkkinen, 2002). The three components of infant temperament (negative reactivity, orienting, and surgency) have been found to differentially predict parenting (Bridgett et al., 2009; Rothbart & Bates, 2006; Planalp, Braungart-Rieker, Lickenbrock, & Zentall, 2013). In addition, the majority of the research examining predictors of parental sensitivity has involved predominantly mother-infant dyads; father-infant dyads are examined less often. The current study aimed to longitudinally examine how parent personality and infant temperament contribute to parental sensitivity over time in 4 (n = 49), 6 (n = 41), and 8 month old (n = 35) infants in both mothers and fathers. Parent personality and infant temperament were assessed via questionnaires filled out by each parent. Parental sensitivity was observationally coded during a dyadic, parent-infant face-to-face play task. Regression analyses revealed differential predictors of parental sensitivity for mothers and fathers and showed partial support for the goodness of fit perspective between the parent’s personality and infant’s temperament.

Abstract Understanding how modern technology plays a role in our children’s early development is especially crucial in this era of technological advancement. Never in human history have we seen such an exponential shift in the human experience than we have with the rise of the internet and the subsequent mass integration of technology into our daily lives. Put simply, times have changed, and our understanding of early childhood development must follow suit. This thesis explores the impact digital technologies have on the neurodevelopment of children, with regard to different critical periods in early childhood development. The apparent impacts on attention, memory, and focus, as well as the behavioral manifestations that result from these childhood interactions depend greatly on the critical period of neurodevelopment they occur. This thesis provides evidence and recommendations for parents and caretakers alike, advising parents on the perils associated with overexposure to sensory stimuli in infants, while demanding a more tailored approach technology mediation in adolescents, as the advent of social media presents its own unique perils and potentials for early neurodevelopment. Keywords: neurodevelopment, technology, infancy, adolescence

Breastfeeding confers immunological, physiological and psychological benefits for the infant and mother as well as social and economic benefits to the nation. The United States Department of Health and Human Servcies (HHS), Healthy People 2020 has established national objectives for the initiation and duration of breastfeeding at 82% initiation, 61% at six months and 34% at one year. In addition, they have set goals for exclusive breastfeeding at 3 months to be 46% and 25% at 6 months of infant's age. Currently breastfeeding initiation is at the highest recorded level of 76.9%, yet significant disparities exist (CDC, 2012). The purpose of this study was to examine the association of acculturation and self-efficacy on breastfeeding behavior of a sample of Hispanic women. Initially the plan was to focus on women from Mexican, Cuban and Puerto Rican countries of origin. However recruitiment goals for only the Mexican population were reached. Two valid and reliable bidimensional instruments were used in addition to collecting contextual information to foster a more comprehensive understanding of the acculturation process. The roles of self-efficacy and social support and their relationship with acculturation measures and breastfeeding behavior was explored. The Non-Hispanic domain subscale of the Bidimensional Acculturation Scale scores were significantly different for those breastfeeding compared to those formula feeding, indicating higher levels of Non-Hispanic domain acculturation associated with not breastfeeding. Acculturation and self efficacy (general and parental) were not found to be related. Breastfeeding outcomes and parental self-efficacy were found to have a significant negative correlation, a finding that was in an unexpected direction, with higher parental self-efficacy associated with decreased breastfeeding intensity. Mixed feeding or Las Dos, is a common finding among Hispanic women especially for the Mexican origin community and exclusivity may not have been perceived as higher value then mixed feeding or formula feeding (Bunik et al., 2006). Rates for exclusive breastfeeding at three months are 33% for both the US as well as for Hispanic/Latino ethnicity (National Immunization Survey, 2007). At six weeks the practice of exclusively breastfeeding (not giving formula) was 17% and this is about half of the 46% goal set for exclusive breastfeeding at three months by (HHS) Healthy People 2020. Of those that were exclusively breastfeeding in the hospital only three were still exclusively breastfeeding at the six week follow up call. This presents a unique opportunity in which targeting Hispanic mothers after discharge may assist in increasing further the rates of exclusive breastfeeding and recommendations are provided.