Rozprawy doktorskie na temat „Longitudinal study”

Workplace interventions to reduce discomfort and sedentary time have been studied in a variety of settings. Adjustable workstations are one type of ergonomic intervention that is used to potentially reduce occupational sitting time, negative health impacts, and to increase productivity. This investigation compared two types of ergonomic interventions, as well as contrasting behavioral interventions among workers with and without adjustable workstations. Seventy-two sedentary office workers were selected to participate in a longitudinal study to evaluate interventions for a reduction in occupational sitting time, to understand the effect on productivity and to evaluate musculoskeletal pain and behaviors. Workers were randomly placed into four different intervention groups and observed over 14 weeks. Group assignments were: control group, employees trained on behavioral interventions, employees given adjustable workstations and the final group had both ergonomic and behavioral interventions. During the study, there was a decrease in discomfort scores and fatigue for the adjustable workstation users. Standing time was increased in groups that had the adjustable workstations and frequency of workstation use remained constant throughout the 14 weeks. There was sufficient evidence to suggest that adjustable workstations will decrease sitting time and decease all over body discomfort in occupations that typically involve long hours of sitting. More research is needed to determine the health benefits of less occupational sitting.

Background: Postnatal depression (PND) follows 10-15% of deliveries. Postnatal blues occur in the first postpartum week and are thought to have little significance. Studies report links between them, PND and premenstrual symptomatology but are methodologically flawed. Hypotheses: Women with severe blues are more likely to become depressed in the 6 months after delivery and more likely to experience premenstrual symptomatology when menstruation resumes. Subjects: First-time mothers who were literate, English speaking, had a singleton pregnancy, no current severe mental illness and whose fetus was healthy. Method: Written informed consent was obtained in late pregnancy. Baseline data include the Eysenck Personality Questionnaire, Edinburgh Postnatal Depression Scale (EPDS), sociodemographic and obstetric details. The Blues Questionnaire was completed on postpartum days 3 & 5. Obstetric data were recorded. Subjects (scores >/75^th centile on the Blues Questionnaire) and controls (\<25^th centile) were matched for age, marital status and social class. All participants completed monthly postal EPDS. When menstruation returned, daily Menstrual Distress Questionnaires and visual analogue scales for premenstrual symptoms were completed for 2 cycles. At 6 months all women with EPDS scores >/9 at any time postpartum were interviewed using the Schedule for Affective Disorder and Schizophrenia (Lifetime version). Research Diagnostic Criteria diagnoses were made for current or past psychiatric disorder. 1 in 5 women with EPDS scores <9 were interviewed to exclude false negatives. Results: Women with severe blues were 3.8 times more likely to become depressed and to have a major rather than minor illness. Their depressions began sooner after delivery and lasted longer than those with no blues. They were more likely to experience premenstrual symptoms. Discussion: Results support the idea that these conditions are variants of affective disorder, severe blues acting as a marker of affective vulnerability. Clinical applications of the results and areas for further research are explored.

In 1998, 12 students, aged 11-12 years, were identified by primary schools in a socially disadvantaged area of New Zealand as being at risk of negative life outcomes, as a consequence of known adversities in their lives. The students were interviewed, as were their parents and teachers, and they also completed learning assessments and measures of personal and social concerns. The purpose of these evaluations was to identify risk and protective factors in the young people’s lives, and to make estimations of personal resilience. In 2008, nine of the original study participants, who were now aged 21-22 years and in emerging adulthood, were located and were interviewed again. The assessments addressed the participant’s current circumstances, and what had happened for them over the last ten years. The interviews also asked the participants to reflect about 12 resilience dimensions that have been identified in the literature (Masten & Coatsworth, 1998) and whether they considered that they were personally resilient. The recent interview data were analysed using interpretative phenomenological analysis (Smith & Osborn, 2008). The individual analyses show a rich diversity of life paths and, as well, three sets of themes were identified across the case studies; and they are personal relationships, contexts of development (schooling and education, culture, religion, and jobs and careers), and personhood and identity. A resilience model was derived from the integration of the data from the first and second assessments with contemporary resilience studies and theorising. The central idea of the model is that resilient functioning is determined by the nature and quality of relationships within, and across, developmental settings. As a corollary, it is hypothesised that interpersonal relationships influence individual executive functioning, and emotional regulation in particular; and that these cognitive and affective capacities can translate into goal seeking and other constructive actions. The explanation of the resilience model leads onto recommendations for further research on relationships that enhance personal functioning. There are also suggestions for social policy that follow from the exposition, and some guidelines for professional practice with children and families.

Seven Vermont school districts participated in a five year professional development program sponsored jointly by the National Science Foundation and the United States Department of Education from 2002-2007. Using a robust mixed methods evaluation, teachers and students demonstrate pronounced organizational and academic growth. Analysis of data from focus groups held with teachers over the course of the period from fall 2004-spring 2006 provides strong supporting evidence for the growth. The purpose of this dissertation is to reanalyze the focus group data to document institutional and longitudinal change at the first person level. With focus groups as the unit of analysis, themes rising from the anonymous participants‟ I statements form the substance for this review. By revisiting an extensive pre-existing data set with a different method of analysis, this work expands on what is known about how teachers process change on the ground level. The findings reveal how complex individual feelings about one‟s experiences serve to describe degrees of institutional as well as personal change. New thematic coding confirms the original findings of the program evaluation. More importantly, the findings provide new details and understandings about organizational change and growth previously unobserved in the aggregate reports. By way of a methodological contribution, the research findings suggest and demonstrate an alternative approach to the analysis of focus group data in the aggregate.

Social media offers a myriad of opportunities for entrepreneurial marketing strategies that leverage the power of communities, especially when they are combined with traditional approaches such as celebrity endorsement. The reach, frequency, and speed of communication on social media offer the ideal leverage for the drivers of entrepreneurial marketing. However, the rapid rate of change may threaten the effects of investments in entrepreneurial marketing on social media and they might become only short-lived. Employing structural equation modeling, we test the long-term effect of Facebook-based celebrity endorsement on purchase intention among 234 members of a Facebook fan community in a two-wave longitudinal design. We argue that this relationship is mediated by a sponsor's brand image and moderated by brand differentiation. This study is the first to investigate the long-term effects of entrepreneurial marketing on social media. We present the contributions and implications of our findings as they affect research and practice.

The purpose of the present study was to examine the applicability of a model of bereavement to the long-term adjustment to loss. Based on Allen's (1990) model, it was predicted that the variables experienced competence, perceived resources, and the impact of the loss would contribute strongly to overall long-term bereavement adjustment. It was also predicted that time and multiple losses would impact adjustment to loss.

Background: Parkinson’s disease (PD) is a progressive neurodegenerative motor disorder. However, non-motor complications frequently alter the course of the disease. A particularly disabling non-motor symptom is dementia. Methods/Design: The study is designed as a multicentre prospective, observational cohort study of about 700 PD patients aged 45–80 years with or without dementia and PD-mild cognitive impairment (MCI). The patients will be recruited in eight specialized movement disorder clinics and will be followed for 36 months. Information about the patients’ functional status will be assessed at baseline and 6-/12- month intervals. In addition, 120 patients with dementia with Lewy bodies (DLB) will be included. Well-established standardized questionnaires/tests will be applied for detailed neuropsychological assessment. In addition, patients will be asked to participate in modules including volumetric MRI, genetic parameters, and neuropsychology to detect risk factors, early diagnostic biomarkers and predictors for dementia in PD. Results: The study included 604 PD patients by March 2011; 56.3% were classified as having PD alone, with 30.6% of patients suffering from PD-MCI and 13.1% from PD with dementia. The mean age of the cohort was 68.6 ± 7.9 years, with a mean disease duration of 6.8 ± 5.4 years. There was a preponderance of patients in the earlier Hoehn and Yahr stages. Conclusion: The main aim of the study is to characterize the natural progression of cognitive impairment in PD and to identify factors which contribute to the evolution and/or progression of the cognitive impairment. To accomplish this aim we established a large cohort of PD patients without cognitive dysfunction, PD patients with MCI, and PD patients with dementia, to characterize these patients in a standardized manner, using imaging (serial structural MRI), genetic and proteomic methods in order to improve our understanding of the course of the PD process and the development of cognitive dysfunction and dementia in this disease. The inclusion of the DLB patients will start in the second quarter of 2011 in the BMBF-funded follow-up project LANDSCAPE.

Background: Parkinson’s disease (PD) is a progressive neurodegenerative motor disorder. However, non-motor complications frequently alter the course of the disease. A particularly disabling non-motor symptom is dementia. Methods/Design: The study is designed as a multicentre prospective, observational cohort study of about 700 PD patients aged 45–80 years with or without dementia and PD-mild cognitive impairment (MCI). The patients will be recruited in eight specialized movement disorder clinics and will be followed for 36 months. Information about the patients’ functional status will be assessed at baseline and 6-/12- month intervals. In addition, 120 patients with dementia with Lewy bodies (DLB) will be included. Well-established standardized questionnaires/tests will be applied for detailed neuropsychological assessment. In addition, patients will be asked to participate in modules including volumetric MRI, genetic parameters, and neuropsychology to detect risk factors, early diagnostic biomarkers and predictors for dementia in PD. Results: The study included 604 PD patients by March 2011; 56.3% were classified as having PD alone, with 30.6% of patients suffering from PD-MCI and 13.1% from PD with dementia. The mean age of the cohort was 68.6 ± 7.9 years, with a mean disease duration of 6.8 ± 5.4 years. There was a preponderance of patients in the earlier Hoehn and Yahr stages. Conclusion: The main aim of the study is to characterize the natural progression of cognitive impairment in PD and to identify factors which contribute to the evolution and/or progression of the cognitive impairment. To accomplish this aim we established a large cohort of PD patients without cognitive dysfunction, PD patients with MCI, and PD patients with dementia, to characterize these patients in a standardized manner, using imaging (serial structural MRI), genetic and proteomic methods in order to improve our understanding of the course of the PD process and the development of cognitive dysfunction and dementia in this disease. The inclusion of the DLB patients will start in the second quarter of 2011 in the BMBF-funded follow-up project LANDSCAPE.

Widespread critical shortages of high-quality teachers in the United States (Sutcher, Darling-Hammond, Carver-Thomas, 2016) has prompted considerable research on staffing trends within the teaching profession. Research suggests both an increase in the demand for teachers and a "chronic and relatively high annual turnover compared with many other occupations" (Ingersoll & Smith, 2003, p. 31). Recent studies have highlighted the negative effects that high teacher turnover has on financial costs, school climate, and student performance. Since attrition rates appear to be higher for beginning teachers (Ingersoll & Smith, 2003; Ingersoll, 2012), it is important to understand why beginning teacher attrition occurs and what factors influence beginning teachers to stay in the profession, move to another school, or return to the profession. While several studies suggest multiple factors influence teacher attrition, having a better understanding of how these factors correlate with each other and how the impact of these factors changes over time will provide additional information into how time influences teacher attrition. Exploring where teaching go after they leave teaching and why some teachers decide to return to the profession will provide additional insight into the complex nature of teacher attrition patterns in the United States. The purpose of this study was to examine attrition patterns among K-12 teachers who began teaching in a public school in the United States during the 2007-2008 academic year and factors that influenced teachers decisions to move from their initial school to another school, discontinue teaching, or return to the position of a K-12 teacher. This study used data collected as part of the Beginning Teacher Longitudinal Study (BTLS) and explores the effect that various predictor variables have on the probability that BTLS teachers will either leave teaching or move to another school. Using a structural equation modeling (SEM) approach to discrete-time survival analysis made it possible to simultaneously model systems of equations that included both latent and observed variables, allow for the effect of mediators, and analyze how the effect of each predictor variable changed over time. Results suggest the higher the teachers' base salary during their first three years of teaching, the less likely they were to leave the profession during their second through fourth years of teaching. Teachers who supplement their base salaries by working extra jobs are more likely to leave the profession after their fourth year of teaching. Teachers who participated in an induction program during their first year of teaching were less likely to leave the profession in Wave 2 of the study and teachers who had taken more courses on teaching methods and strategies before they started teaching were less likely to leave teaching in all waves of the study than teachers who had taken fewer courses on teaching methods or strategies. Teachers who reported higher levels of positive school climate during their first year of teaching were less likely to leave the profession in Wave 2 and 4. Teachers who indicated higher levels of satisfaction with being a teacher in their school were less likely to move schools than teachers with lower levels of satisfaction and teachers who taught in schools with higher percentages of students who were approved for free or reduced prices lunches were more likely to move schools than teachers with lower percentages of students who were approved for free or reduced price lunches. However, due to convergence issues, these results should be interpreted with caution. Weighted item response descriptive analyses suggest teachers' most important reason for moving schools was to work in a school more convenient to their home. Teachers who leave teaching are more likely to enter professions or occupations in education-related fields than occupations outside the field of education. Results also suggest teachers who leave the profession of teaching are more likely to be working in a job, either full-time or part-time, than not working in job. Finally, the majority of teachers who return to the profession of teaching do so because they missed being a K-12 teacher or they want to make a difference in the lives of others. This study contributes to the existing literature on teacher attrition by testing whether multiple relationships exist between various predictor variables and beginning teacher attrition and examines how the influence of each of these predictor variables changes over time. The study also investigates topics that have been relatively unexplored in the literature, including where teachers go when they leave the profession and factors that influence teachers' decisions to return to the profession. The results of this study may benefit researchers, teachers, educators, administrators, and policy makers interested in and/or studying teacher attrition in the United States.

Aquesta tesi se centra en la tendència creixent d’organització plana i autogestió a l’organització post-burocràtica. Recentment, un sistema organitzatiu anomenat holacracy ha sorgit com un sistema organitzatiu menys jeràrquic però burocràtic. Mitjançant un estudi etnogràfic longitudinal, aquesta tesi examina empíricament com pot funcionar una organització que practica l'holacratia, per teoritzar el fenomen de l'organització post-burocràtica. A més, aquesta tesi investiga empíricament com es veuen afectats els directius que no estan amarrats per la conversió de l’organització a l’autogestió i, al seu torn, poden afectar l’organització. Finalment, aquesta tesi explora i conceptualitza la utilitat de la subjectivitat i la intimitat en l'enfocament investigador del fenomen nou. Aquesta tesi contribueix a la teoria de l’organització introduint un model de burocràcia pluralista, explicant com es pot conciliar l’autonomia i l’alineació dins d’una burocràcia plural en lloc de romandre en paradoxa. També analitza com el poder es relaciona amb la identitat a mesura que els administradors fan front a la pèrdua del seu estatus posicional sense perdre el lloc de treball en una transformació organitzativa a l'holacràcia. Finalment, aquesta tesi presenta una teorització primerenca sobre el concepte d’intimitat hermenèutica, oferint un enfocament metodològic matisat per navegar entre la relació i el jo per produir investigacions d’alta qualitat.
Esta tesis se centra en la tendencia ascendente de la organización plana y la autogestión en la organización posburocrática. Recientemente, ha surgido un sistema organizativo llamado holacracia como un sistema organizativo menos jerárquico pero burocrático. Mediante un estudio etnográfico longitudinal, esta tesis examina empíricamente cómo es capaz de funcionar una organización que practica la holacracia, para teorizar el fenómeno de la organización posburocrática. Además, esta tesis investiga empíricamente cómo se ven afectados los gerentes desanimados por la conversión de la organización a la autogestión y, a su vez, pueden afectar a la organización. Finalmente, esta tesis explora y conceptualiza la utilidad de la subjetividad y la intimidad en el enfoque de investigación del fenómeno novedoso. Esta tesis contribuye a la teoría organizacional al introducir un modelo de burocracia pluralista, explicando cómo la autonomía y el alineamiento dentro de una burocracia pluralista pueden reconciliarse en lugar de permanecer en la paradoja. También analiza cómo el poder se relaciona con la identidad cuando los gerentes enfrentan la pérdida de su estatus posicional sin perder sus puestos de trabajo en una transformación organizacional en holacracia. Finalmente, esta tesis presenta una teorización temprana sobre el concepto de intimidad hermenéutica, al ofrecer un enfoque metodológico matizado para navegar la relación y el yo para producir una investigación de alta calidad.
This thesis focuses on the rising trend of flat organization and self-management in the post-bureaucratic organization. Recently, an organizational system called holacracy has emerged as a less hierarchical yet bureaucratic organizational system. Through longitudinal ethnographic study, this thesis empirically examines how an organization practicing holacracy is able to function, in order to theorize the phenomenon of post-bureaucratic organization. Additionally, this thesis empirically investigates how managers unmoored by the organization’s conversion to self-management are affected and in turn may affect the organization. Finally, this thesis explores and conceptualizes the usefulness of subjectivity and intimacy in the research approach of novel phenomenon. This thesis contributes to organizational theory by introducing a model of pluralistic bureaucracy, explaining how autonomy and alignment within a pluralistic bureaucracy can be reconciled rather than remaining in paradox. It also analyzes how power relates to identity as managers cope with losing their positional status without losing their jobs in an organizational transformation to holacracy. Finally, this thesis presents early theorization on the concept of hermeneutic intimacy, by offering a nuanced methodological approach for navigating relationship and self to produce high-quality research.

Objective: To examine the psychological processes that occur whilst people are taking obesity medication orlistat and to assess longer term changes in weight, beliefs and behaviour over an 18 month period. Background: Orlistat functions by reducing fat absorption. Research indicates that orlistat can have a significant impact on weight loss however there is some variability in outcomes and it is still not clear where the variability arises from. Method: A questionnaire was completed at baseline (n=1582), 6 (n=572), 12 (n=443) and 18 months (n=519) to explore predictors of change in weight, beliefs and behaviour. The data was analysed at baseline (n=1582), 0 to 6 months. (n=572), 0 to 18 months (n=519) and the process of change over the 18 months (n=296). 10 individuals who failed to lose weight after 18 months were interviewed. The qualitative data was analysed using IPA to examine participants' explanations for their weight loss failure. Results: The results show a significant decline in weight over the first 6 months (4.5kg), then a gradual regain. Successful weight loss was related to significant event motivations, adhering to orlistat, eating less fat and greater perceived control over their weight. Orlistat functioned by educating them in what foods should not be eaten through the side effects and showed them that their weight could be controlled. To reduce failure, people needed to have a shift in identity towards someone who no longer expected to fail and to endorse the efficacy of their current method of weight loss whilst overcoming barriers. Conclusion: Successful weight loss was related to a significant event motivation and believing their weight is controllable. The additional impact of orlistat is that it promotes healthy eating and shows their weight can be controlled, which facilitates long term weight loss and maintenance.

Specific Reading Difficulty (SRD), also known as developmental dyslexia, affects approximately 5-10% of the population (Habib, 2000). The predominant explanation is that deficits in phonological awareness lead to reading difficulty (e.g. Snowling, 2000), although causal explanations remain weak (Castles & Coltheart, 2004). An alternative explanation is that visual deficits can lead to reading difficulty (e.g. Stein & Walsh, 1997). We compared 93 children with SRD and 102 matched controls on tests of visual function (motion coherence detection, visual search), phonology (Rhyme and Spoonerisms subscales of the Phonological Assessment Battery) and auditory discrimination (FM Sensitivity), to determine which deficits were most associated with reading disability. Significant group differences on the tests of phonology and reading were found, but no other. This result supported the phonological deficit hypothesis.

Accepting the view that the marketing process is centred on exchange between two parties (Hunt, 2002), it follows that exchange will take place between two (or more) parties when each party trades something of value in return for something of greater value. Consequently the logical conclusion is that value is the cornerstone of marketing (see for example Eggert and Ulaga, 2002; Holbrook, 2005). Perceptions of value can vary over time and experience (Eggert and Ulaga, 2002; Woodall, 2003; Sánchez-Fernandez and Iniesta-Bonillo, 2007). However, even though the temporal nature of value is widely acknowledged, research in this area has been largely overlooked, and while there is limited investigation within the b2b domain (see Flint et al., 2002; Beverland and Lockshin, 2003; Eggert et al., 2006) a literature search has been unable to identify any research that examines actual changes in perceptions of value within consumer research. Consequently, the aim of this study is to empirically examine the temporal stability (i.e., the nature and strength) of the functional relationships between value and its antecedents and outcomes. In order to address the above aim a theoretically grounded model is proposed. Based on common acceptance among researchers (see review by Woodall, 2003) value is conceptualised as the result of a 'trade-off' between benefits (get) and sacrifices (give). However, instead of treating value as a composite higher order construct the behaviours of its two components (get and give) with the following constructs are examined separately: service quality and personal values (terminal and instrumental) are modelled as determinants while satisfaction and intention are the outcomes of value. In addition the impact of knowledge (cognitive; Woodruff, 1997) and emotions (affective; Richins, 1997) as direct determinants of value and additionally as moderators of the value to satisfaction relationship is tested. The research was-conducted within the Higher Education sector among consumers of postgraduate education at a London business school. To test the temporal stability and pattern of development of the functional relationships between the value components and their above defined nomologically related constructs, related data were collected longitudinally from two sample of cohorts at three points in time (i.e., the beginning, middle and end of their studies) via a personally (Times 1 and 2) and internet (Time 3) administrated questionnaire. A total of 34 and 45 usable responses were collected from Cohorts 1 and 2 respectively over the three time points. The data were analysed using Partial Least Squares. Analysis indicates that the give component of value should be separated into money, and time and effort (denoted in this study as give). There is support for knowledge and emotions as direct determinants of the now three value components rather than as moderators of the relationships between these components and satisfaction. Comparisons between the two cohorts reveal the existence of a number of significant differences in the relative strength of corresponding relationships. Finally, in terms of the focal interest of this study, there is substantial evidence of the temporal nature of the functional relationships of the value components. Four of the hypothesised relationships are supported only at a single time point, while a number of significant changes in the strength of the functional relationships between the three points in time are identified. The research is considered to make the following contributions to the subject matter. It confirms the idiosyncratic nature of the value components in terms of their functional relationship with antecedents and consequences. It highlights the need to consider the location of monetary sacrifice within the give component. The existence of a time lag before some determinants have a significant impact on the formation of value is identified. There is tentative evidence to suggest that as consumption progresses, value is formed by a larger number of determinants. For the get component, significant variations in the strength of its functional relationships over time are found to exist.

The purpose of this study was to compare selected kinematic characteristics of distance runners over a twenty year period. The subjects in the investigation were 14 long distance runners who at the time of the first observation were considered highly trained (running more than 50 miles per week). The second observation occurred approximately 20-23 years after the first observation. At this time the average weekly mileage per runner had decreased to 37 miles per week. The first observation's data were collected with a Locam camera at film speeds ranging from 60 to 120 frames/second. The film data were digitized at the same time as the second observation's data. The second observation's data were collected with a Panasonic 5000 shutter video camera. The Peak Performance Motion Measurement System video interface allowed a 60 frame/second field rate. Ten subjects ran at a speed of 3.4 m/s; two subjects at the speeds of 3.1 and 3.6 m/s; and one subject at each of the following speeds: 4.0, 4.5, and 4.9 m/s. Statistical analyses (ANOVA) of the stride length, stride frequency, support and non-support time, and joint angular displacement indicated no significant difference (p > .05) between the first observation and the second observation. The results of this study indicated that the kinematics of continually active long distance runners do not change with an increase in age.
School of Physical Education

This thesis seeks to make sense of the complexity of the experience of becoming a disabled mother as made and lived in a dynamic process that is social, embodied, emotional, and temporal. There is limited empirical research that has investigated the experience of disabled motherhood and a relative absence of research that has followed disabled women's processes of identity over the course of the first year of motherhood. This thesis seeks to fill that gap. The empirical base for this thesis includes material collected from six longitudinal case studies, with disabled women interviewed three times in the first-year transition to becoming a mother. By focusing on what women do with their bodies, or their pursuit of distinct body projects, I reveal insights into my participants' experience and understanding of disability at this stage in the life-course, during which the embodied experience is subject to change and transformation. Drawing on post-structural concepts of power and agency, I explore the possibilities and limitations within my participants' strategies of sense-making for engineering a liveable life in relation to dominant social norms. These in sights speak to a debate within the disability movement about the nature of disability (as experience) as the basis of individual and collective identity and the kind of support disabled mothers need, which can inform social and healthcare practice. Methodologically, I utilise an innovative psycho-social longitudinal research design and method to enrich and develop my understanding of this process. Researcher subjectivity, difference and temporality are all regarded as important tools for revealing emotional dynamics and processes of intelligibility.

Thesis (M.A.)--University of Cincinnati, 2005.
Advisor: Steve Carlton-Ford. Title from electronic thesis title page (viewed Mar. 26, 2009). Includes abstract. Keywords: child sexual abuse; revictimization; rates. Includes bibliographical references.

This study examines how hopelessness impacts youth engagement in violent behavior over time. The data are from waves I and II of The National Longitudinal Study of Adolescent Health (Add Health). Poisson regression was used to analyze contributors to violence in just wave I, and then again across time in wave II using explanatory and control variables from wave I. Results indicate that hopelessness is positively associated with violent behavior. Furthermore, while hopelessness and most of the other explanatory variables predicted violent behavior in wave I, almost all the variables became non-significant or negative except hopelessness and a measure of community when predicting violence in wave II. This shows that hopelessness is a concept that needs to be explored more closely when studying violence among youth.

This dissertation was designed to measure the longitudinal effects of several maternal and infant variables, on the security of attachment as assessed by the Strange Situation. The sixty mother-infant dyads who participated in this study were recruited from three Tidewater prenatal clinics. The goal of this dissertation was to determine the correlation of maternal and infant constructs with the criterion variables of maternal perception of her baby and the Strange Situation. The statistical technique of path analysis was utilized to analyze data collected over five periods: prenatal, postpartum, three-, six- and sixteen-months. The results of the path analysis revealed that the prenatal variables, maternal sources of social support and perception of early childhood experiences predicted a significant amount of the variance in the Strange Situation classifications (secure versus insecure) when the infants were sixteen months old. The path analysis interpretation also demonstrated that the maternal variables: (1) sources of social support; (2) emotional status; (3) knowledge of infant growth and development; (4) maternal personality integration; (5) maternal age; and (6) measures of stress all influenced the maternal perception of her infant during at least one of the data collection periods. Finally, the path analysis demonstrated that infant variables: (1) gender; (2) differences in neonatal responsiveness; (3) temperament; and (4) maternal-infant interaction also impacted upon the mother's perception of her baby. The only variable that was not related to either the Maternal Perception of the Infant or the Strange Situation was the Infant Developmental Status as measured by the Bayley Scales of Infant Mental and Motor Development Behavior Record.

Objective: The purpose of this study to assess the relationship between masticatory function and symphyseal biomechanical properties using a longitudinal sample. Known differences in male and female maximum bite forces manifest during adolescence. If symphyseal bending rigidity is affected by function during ontongeny, we would expect variation in male and female growth allometries of certain biomechanical properties of the symphysis. Methods and Materials: Subjects were chosen from the Iowa Growth Study records for completeness and quality of radiographic images longitudinally. 19 females and 20 males were chosen. Lateral ceph images from 9 timepoints (age 3-20) were used to trace the external cortical outline of the symphysis. The biomechanical parameters (second moments of area (Ix, Iy, Imax, Imin)) were calculated from the external contours of the symphysis. Mandibular length was used as a proxy for overall mandibular size. All variables were scaled and growth allometries calculated by a reduced major axis regression. Clarke's T-test was used to test for significance. ANCOVA was used assess the interaction between symphyseal properties and sex, mandibular length, and sex+mandibular length. Results: No significant differences in symphyseal growth allometries of males and females were found (p>.05). No significant interactions between symphyseal properties and sex, and sex+mandibular length. (p>.05). A significant interaction between symphyseal properties and mandibular length was found (p<.05). Conclusions: Despite greater bite forces in males that manifest during adolescence, there were no differences in symphyseal growth allometries between males and females. Perhaps function does not play a significant role in development of symphyseal form. Perhaps the subtle effects of function on symphyseal morphology cannot be assessed by using only external cortical outlines for evaluation of symphyseal biomechanical parameters.

Longitudinal studies rely on data collected at several occasions from a set of selected individuals. The purpose of these studies is to use a regression-type model to express a response variable as a function of explanatory variables, or covariates. In this thesis, we use marginal models for the analysis of such data, which, coupled with the method of estimating equations, provide estimators of the main regression parameter. When some of the responses are missing or there is error in the recorded covariates, the original estimating equation may be biased. We use techniques available in the literature to modify it and regain the unbiasedness property. We prove the asymptotic normality of the regression estimator obtained under these more realistic circumstances, and provide theoretical and numerical examples to illustrate this approach.

L’esquizotímia es configura com un contínuum de símptomes subclínics i clínics, i del funcionament que en el seu extrem es manifesta com a trastorns de l’espectre de l’esquizofrènia. L’esquizotípia i l’esquizofrènia comparteixen una estructura multidimensional comparable, sent les dimensions positives i negatives els factors més recolzats. Estudis transversals previs que van utilitzar l’estratègia psicomètrica d’alt risc van indicar que l’esquizotípia és un mètode útil per identificar els factors de risc i protecció per al desenvolupament de la psicopatologia de l’espectre esquizofrènic. Tot i així, les investigacions longitudinals segueixen sent escasses. El cos de la tesi inclou tres capítols que investiguen la validesa predictiva de les dimensions positives i negatives de l’esquizotípia, l’estabilitat temporal dels símptomes i els trets de l’espectre de l’esquizofrènia en individus amb alta esquizotípia, i el paper de l’esquizotípia positiva i negativa com a possibles marcadors de risc distal que moderen les associacions dels estressors amb símptomes quasi-psicòtics, paranoides i negatius experimentats en la vida diària en una mostra no-clínica. El capítol 1 presenta un estudi destinat a ampliar les troballes transversals prèvies examinant si l’esquizotípia negativa i positiva basals, valorades psicomètricament, prediuen diferencialment els símptomes prodròmics, els trastorns de personalitat de l’espectre de l’esquizofrènia i el funcionament 3 anys després. A més, examina l’estabilitat temporal d’aquests constructes durant un període de 1,4 anys. Les dues dimensions esquizotípiques van predir símptomes de la personalitat esquizotípica, paranoide, i evitativa a més d’un deteriorament en el funcionament. L’ esquizotípia positiva va predir símptomes quasi-psicòtics, depressió, baixa autoestima i psicopatologia general. L’esquizotípia negativa va predir trastorns emocionals i personalitat esquizoide, i haver rebut un tractament de salut mental durant l’últim any. Les personalitats, els símptomes prodròmics i el funcionament van predir els mateixos constructes 1,4 anys després. El Capítol 2 descriu un estudi destinat a ampliar les nostres troballes anteriors a l’examinar longitudinalment si l’esquizotípia positiva i negativa prediu símptomes i deteriorament en el funcionament 4.4 anys després. Aquest estudi investiga la validesa dels símptomes negatius mesurats per dos instruments d’entrevista. L’ esquizotípia negativa va predir de manera única els trets esquizoides, els símptomes negatius, el deteriorament en el funcionament i esquemes cognitius positius dels altres. L’ esquizotípia positiva va predir de manera única els trets de la personalitat evitativa i esquemes cognitius negatius dels altres. Les dues dimensions van predir trets de les personalitats esquizotípica i paranoide, sospita, depressió i esquemes negatius del jo. Les dues dimensions van predir símptomes positius i una disminució dels esquemes positius dels altres. Els resultats indiquen que la sub-escala negativa de la CAARMS està saturada per desregulació afectiva, mentre que el NSM sembla ser un instrument vàlid per avaluar símptomes negatius. El capítol 3 presenta un estudi que investiga l’expressió de l’esquizotípia positiva i negativa en la vida real utilitzant la tècnica Experience Sampling Methodology. L’estudi examina les associacions longitudinals de l’esquizotípia positiva i negativa, així com la seva associació transversal amb les experiències esquizotípiques en la vida diària. Busca ampliar els estudis previs al investigar com l’estrès prediu l’expressió dels símptomes psicòtics, paranoics i negatius en individus amb esquizotípia alta en la vida diària. L’ esquizotípia positiva va predir símptomes quasi-psicòtics i paranoides, la negativa va predir un subconjunt d’aquests símptomes i va mostrar una tendència cap a la significació en la predicció de símptomes negatius.
La esquizotipia se configura como un continuum de síntomas subclínicos y clínicos, y del funcionamiento que en su extremo se manifiesta como trastornos del espectro de la esquizofrenia. La esquizotipia y la esquizofrenia comparten una estructura multidimensional comparable, siendo las dimensiones positivas y negativas los factores más respaldados. Estudios transversales previos que emplearon la estrategia psicométrica de alto riesgo indicaron que la esquizotipia es un método útil para identificar los factores de riesgo y los de protección para el desarrollo de la psicopatología del espectro esquizofrénico. Sin embargo, las investigaciones longitudinales siguen siendo escasas. El cuerpo de la tesis incluye tres capítulos que investigan la validez predictiva de las dimensiones positivas y negativas de la esquizotipia, la estabilidad temporal de los síntomas y rasgos del espectro de esquizofrenia en individuos con alta esquizotipia, y el papel de la esquizotipia positiva y negativa como posibles marcadores de riesgo distal que moderan las asociaciones de los estresores con síntomas casi-psicóticos, paranoides y negativos experimentados en la vida diaria en una muestra no-clínica. El Capítulo 1 presenta un estudio destinado a ampliar los hallazgos transversales previos examinando si la esquizotipia negativa y positiva basales, valoradas psicométricamente, predicen diferencialmente los síntomas prodrómicos, los trastornos de personalidad del espectro de la esquizofrenia y el funcionamiento 3 años después. Además, examina la estabilidad temporal de estos constructos durante un período de 1,4 años. Ambas dimensiones esquizotípicas basales predijeron síntomas de la personalidad esquizotípica, paranoide, y evitativa además de deterioro en el funcionamiento. La esquizotipia positiva predijo síntomas casi-psicóticos, depresión, baja autoestima y psicopatología general. La esquizotipia negativa predijo trastornos emocionales y personalidad esquizoide, y haber recibido tratamiento de salud mental durante el último año. Las personalidades, los síntomas prodrómicos y el funcionamiento predijeron los mismos constructos 1,4 años después. El Capítulo 2 describe un estudio destinado a extender nuestros hallazgos anteriores al examinar longitudinalmente si la esquizotipia positiva y negativa predice síntomas y deterioro en el funcionamiento 4.4 años después. Este estudio investiga la validez de los síntomas negativos medidos por dos instrumentos de entrevista. La esquizotipia negativa predijo de manera única los rasgos esquizoides, los síntomas negativos, el deterioro en el funcionamiento y esquemas cognitivos positivos de los otros. La esquizotipia positiva predijo de manera única los rasgos de la personalidad evitativa y esquemas cognitivos negativos de los otros. Ambas dimensiones predijeron rasgos de las personalidades esquizotípica y paranoide, sospecha, depresión y esquemas negativos del yo. Las dos dimensiones predijeron síntomas positivos y una disminución de los esquemas positivos de los otros. Los resultados indican que la sub-escala negativa de la CAARMS está saturada por desregulación afectiva, mientras que el NSM parece ser un instrumento válido para evaluar síntomas negativos. El Capítulo 3 presenta un estudio que investiga la expresión de la esquizotipia positiva y negativa en la vida real usando la técnica Experience Sampling Methodology. El estudio examina las asociaciones longitudinales de la esquizotipia positiva y negativa, así como su asociación transversal con las experiencias esquizotípicas en la vida diaria. Busca extender los estudios previos al investigar cómo el estrés predice la expresión en el entorno real de los síntomas psicóticos, paranoicos y negativos en individuos con esquizotipia alta. La esquizotipia positiva predijo síntomas casi-psicóticos y paranoides, la negativa predijo un subconjunto de estos síntomas y mostró una tendencia hacia la significación en la predicción de síntomas negativos.
Schizotypy is operationalized as a continuum of personality traits, subclinical and clinical symptoms as well as impairment that, in its extreme form, is manifested as schizophrenia-spectrum disorders. Schizotypy and schizophrenia share a comparable multidimensional structure with positive and negative dimensions being the most strongly supported factors. Previous cross-sectional studies employing the psychometric high-risk strategy indicated that schizotypy is a useful method for identifying risk and resilience factors for the development of schizophrenia-spectrum psychopathology. However, longitudinal investigations remain scarce. This thesis includes three chapters investigating the predictive validity of positive and negative schizotypy dimensions, the temporal stability of schizophrenia-spectrum symptoms and traits in high schizotypy individuals, and the role of positive and negative schizotypy as potential distal risk markers moderating the association of stress with psychotic-like, paranoid, and negative symptoms experienced in the real life environment. Chapter 1 presents a study aimed at extending previous cross-sectional findings by investigating whether baseline psychometrically assessed negative and positive schizotypy differentially predict clinical risk symptoms, schizophrenia-spectrum personality disorders (PDs), and functioning in a nonclinical sample 3 years later. Additionally, this study examines the temporal stability of these constructs over a 1.4-year period. Both Time 1 (T1) schizotypy dimensions predicted schizotypal, paranoid, avoidant PDs, and functioning at Time 3 (T3). Positive schizotypy specifically predicted psychotic-like symptoms, depression, low self-esteem, and general psychopathology at T3. Negative schizotypy predicted emotional disturbances and schizoid PD at T3, as well as receiving mental health treatment over the past year. PDs, prodromal symptoms, and functioning assessed at Time 2 (T2) predicted the same constructs at T3. Chapter 2 describes a study aimed to extend our previous findings by examining whether longitudinal assessment of baseline positive and negative schizotypy at baseline predicted interview-based ratings of symptoms and impairment 4.4 years later. Furthermore, since the relationship between negative schizotypy traits and symptoms with depressive symptoms remains an unresolved issue, this study investigated the validity of negative symptoms as measured by two interview instruments. Baseline negative schizotypy uniquely predicted schizoid PD traits, negative symptoms, impaired functioning, and diminished positive self-schemas at the 4-year follow-up. Baseline positive schizotypy uniquely predicted avoidant PD traits and negative other-schemas. Both dimensions predicted schizotypal and paranoid PD traits, suspiciousness, depression, and negative self-schemas 4.4 years later. In addition, the two dimensions predicted positive symptoms (the effect size was larger for positive schizotypy) and diminished positive other-schemas (the effect size was larger for negative schizotypy). Baseline negative, but not positive, schizotypy predicted negative symptoms as assessed by CAARMS and NSM. However, only the prediction of NSM negative symptoms by negative schizotypy remained significant after controlling for affective dysregulation (i.e., dimensional scores of avoidant personality, anxiety and depression). Chapter 3 presents a study investigating the real-life expression of positive and negative schizotypy using the Experience Sampling Method. This study examined the prospective association of baseline positive and negative schizotypy as well as their cross-sectional association with schizotypic symptoms and experiences in daily life. Moreover, this report sought to extend previous research by investigating how daily life stress and social contact differentially predicted the real life expression of psychotic-like, paranoid, and negative symptoms in high schizotypy individuals.

Introduction The present study explored the nature of the semantic deterioration normally displayed in the course of Alzheimer’s disease (AD). The aim was to disentangle the extent to which semantic memory problems in patients with AD are best characterized as loss of semantic knowledge rather than difficulties in accessing semantic knowledge. Method A longitudinal approach was applied. The same semantic tests as well as same items were used across three test occasions a year apart. Twelve Alzheimer patients and 20 matched control subjects, out of a total of 25 cases in each group, remained at the final test occasion. Results and Conclusions Alzheimer patients were impaired in all the semantic tasks as compared to the matched comparison group. A progressing deterioration was evident during the study period. Our findings suggest that semantic impairment is mainly due to loss of information rather than problems in accessing semantic information.

Dogslife is the first large-scale, longitudinal cohort study of canine lifestyle, morphology and health. The project involves recruiting the owners of UK-based, Kennel Club registered Labrador Retrievers and asking them to submit data about their dogs via an online questionnaire repeatedly as the dogs age. In this thesis, I have analysed Dogslife data regarding the lifestyle, morphology and health of Labrador Retrievers up to four years of age. A validation study was initially undertaken in order to understand the quality of the Dogslife data because this would underlie all future investigations. Owners were visited and veterinary records scrutinised. It was determined that Dogslife illness reports were subject to recall decay and that minor changes would improve the usability of the questionnaire. Accelerometers were subsequently sent to a subset of the cohort and aspects of the Dogslife exercise questionnaire were found to be correlated to accelerometer readings indicative of sedentary, light and moderate to vigorous exercise. Overall, Dogslife dogs were exercised for over two hours each day with the time spent being dominated by time off lead and on other activities. Dogs in England spent less time exercising than those in Scotland and Wales and dogs in family households spent less time exercising than those in single adult households or households comprising more than one adult. Despite being pedigree animals, the males in the cohort were 2-3cm taller than the breed standard. On average, the females met the breed standard but there was wide variation for both sexes. Working dogs in the cohort were over 2kg lighter than household pets and chocolate coloured dogs were 1.4kg heavier than their black and yellow counterparts. Dogs in multi-dog households were 0.5kg lighter than those in households with no other dog. Heavier dogs spent less time fetching, chasing and retrieving and on other exercise. Over 6,000 signs of illness were reported to Dogslife in the first three and half years and approximately half of them did not involve a veterinary visit. Reported signs were dominated by vomiting and diarrhoea, both of which peaked when the dogs were between 3-6 months of age. For the first time, rates of diarrhoea were shown to be positively associated with human population density in the UK. Limber tail was found to be associated with swimming in the cohort and working dogs were more likely to develop the condition than pets. Genetic analyses identified regions of interest that might predispose the dogs to limber tail on chromosomes 6 and 30. Data from the Dogslife project provide a unique resource for investigating the epidemiology of Labrador Retrievers. This thesis creates a platform for all such future investigations.

A l'adolescence, la maturation cérébrale implique des changements anatomiques globaux et régionaux subtils, et estimer la morphologie exacte de certaines structures au cours du développement post-pubertaire est par conséquent difficile. L'effet du dimorphisme sexuel sur la maturation cérébrale n'a été que très peu exploré de façon prospective par l'imagerie par résonance magnétique. Dans ce contexte, ce travail de thèse est consacré à l'étude longitudinale des effets du sexe sur la maturation cérébrale à l'aide de deux méthodes pour contrôler et analyser les variations de positionnement spatial des images acquises à différents intervalles de temps. Dans une première étude utilisant une approche multimodale, notre objectif était d'examiner si le dimorphisme sexuel dans la maturation cérébrale du système limbique pouvait expliquer les différences émotionnelles entre les filles et les garçons pendant l'adolescence. Nous avons adapté pour cela une méthode de traitement longitudinal sur des images anatomiques et de diffusion de 335 adolescents sains entre 14 et 16 ans. Nous avons mis en évidence des différences sexuelles dans la maturation cérébrale du système limbique avec une maturation plus tardive des garçons par rapport aux filles. Ces changements avaient un rôle médiateur sur les différences sexuelles dans la régulation émotionnelle, illustrée par une augmentation des traits de personnalité positifs chez les garçons et une diminution chez les filles. Dans une deuxième étude utilisant une approche originale de recalage, notre objectif était d'estimer et extrapoler des trajectoires de maturation en fonction du dimorphisme sexuel. Nous avons mis en évidence des trajectoires divergentes entre les filles et les garçons entre 14 et 16 ans, illustrant une différenciation des vitesses de maturation croissante à cette période, spécifiquement dans le cortex préfrontal. Ces trajectoires différentielles ont permis d'estimer une avance de maturation de 5 mois chez les filles dans le cortex préfrontal. L'ensemble de ces résultats apporte des informations utiles à une meilleure compréhension des différences de maturation cérébrale entre les filles et les garçons, et de leurs liens avec la dérégulation du système émotionnel et donc la vulnérabilité à la dépression à l'adolescence
In adolescence, brain maturation involves subtle global and regional anatomical changes, and estimating the exact morphology of some structures during post-pubertal development is therefore difficult. Effect of sexual dimorphism on brain maturation has been under-explored prospectively by magnetic resonance imaging. In this context, this work is focused on the longitudinal study of the effects of sex on brain maturation using two methods to control and analyze the spatial positioning variations of images acquired at different time points. In a first study using a multimodal approach, our goal was to examine sexual dimorphism in brain maturation of the limbic system to explain the emotional differences between girls and boys during adolescence. We adapted a method of longitudinal processing on anatomical and diffusion images of 335 healthy adolescents between 14 and 16 years. We highlighted sexual differences in brain maturation of the limbic system with a later maturation of boys compared to girls. These changes mediated sexual differences in emotional regulation, illustrated by an increase in positive personality traits in boys and a decrease in girls. In a second study using an original registration approach, our objective was to estimate and extrapolate maturation trajectories based on sexual dimorphism. We highlighted divergent trajectories between girls and boys between 14 and 16, illustrating a differentiation in maturation rates that increased during this period, specifically in the prefrontal cortex. These differential trajectories made it possible to estimate a maturational advance of 5 months in girls in the prefrontal cortex. All these results provide useful information for a better understanding of the differences in brain maturation between girls and boys, and their links with the emotional system dysregulation and therefore the vulnerability to depression in adolescence

Research indicates that preschool experience significantly influences child development and this study examined the influence of preschool learning experiences on children’s school readiness, self-regulation and academic achievement. Participants were 190 children from an impoverished county in Southwest China and their teachers. Classroom observations were conducted and children were assessed in individual and group sessions. There were three different types of preschool programs (kindergartens, pre-primary classes; Grade 1) available in the county. A total of 18 teaching episodes provided in either the kindergarten or primary schools to 164 children were videotaped and analyzed. Results indicated marked variations in preschool quality and pedagogical practices to support children’s self-regulation across programs. Kindergartens had the best physical environments, the most resources and highly qualified teachers. The teachers provided children with meaningful learning opportunities, adequate instructions, clear structure and predictability, and diversified instructional formats. Pre-primary classes had limited resources and unqualified teachers who emphasized academic learning. Compared to kindergarten teachers, pre-primary class teachers prepared fewer activities and frequently required children to simply sit still and listen. Preschool age children who merely “sat in” Grade 1 classrooms were typically neglected by teachers and only received attention from the teacher when they were disruptive. Grade 1 children (89 girls) who had attended kindergarten (n = 60), separate pre-primary classes (n = 55), merely “sat in” Grade 1 classes before being formally enrolled in school (n = 54) or had no preschool experience (n = 21) were assessed at the beginning of Grade 1 (Wave 1), at the end of Grade 1 (Wave 2), and at the end of Grade 2 (Wave 3). Their school readiness was assessed in Wave 1. Their self-regulation skills were assessed using the modified Head-Toes-Knees-Shoulders task in Waves 1 and 2, and seven cognitive regulation tests in Wave 3. Their literacy and mathematics achievement was evaluated using curriculum-based tests across the three waves. Results indicated that children with some form of preschool experience outperformed those with none in almost all the three outcomes across the three waves. Children from the kindergarten had better school readiness than the other three groups and better self-regulation than those attending separate pre-primary classes at the start of school. Children attending separate pre-primary classes had significantly better literacy and mathematics than those from the kindergarten at the start of school and literacy at the end of Grade 2. Children “sitting in” Grade 1 classes achieved lower scores than those from the kindergarten and pre-primary classes on almost all child outcome measures. The growth of self-regulation within the first primary school year was significant and Wave 1 behavioral regulation predicted Wave 3 cognitive regulation. School readiness and self-regulation significantly predicted academic achievement in all three waves and school readiness mediated the close relationship between self-regulation and academic achievement. Findings highlight the importance of (i) preschool experience for children from economically disadvantaged families in rural China; and (ii) self-regulation in school preparedness and early academic attainment. They also have implications for scaling up and enhancing the quality of preschool programs.
published_or_final_version
Education
Doctoral
Doctor of Philosophy

The aim of this thesis was to identify risk factors for the onset of adult asthma. Other objectives were to study determinants of smoking habits and the association between sensitization and outcome of asthma. In 1990, a questionnaire was distributed to 12,732 individuals from three age groups (16, 30-39 and 60-69 years) in two counties of Sweden. In a second phase, 2538 subjects who had reported respiratory symptoms and 600 controls were invited to clinical investigations, 81% participated. At the follow-up in 2003 subjects of the remaining cohort (11,282) were re-invited. Analyses are based on the 67% (n=7563) who responded to both questionnaires 1990 and 2003. In 2003, 17.2% of the young adults, 11.4% of the middle-aged and 10.3% of the elderly reported having, or having had, asthma. A total of 791 subjects reported onset of asthma during the 13-year study period. Lifestyle factors such as smoking, obesity, hard physical training and a low consumption of fruit and fish were constant risk factors for onset of asthma after adjusting for socioeconomic group. A smoker’s risk of asthma onset was increased by 37%. The impact of risk factors differed between the age-groups. BMI had a significantly higher impact in the middle-aged and elderly. In subjects participating in the clinical investigations in 1990, sensitization to pets, were determinants of both persistent asthma and onset of asthma in 2003. The risk for persistent asthma was threefold. The risk for onset of asthma was more than doubled. Smoking at baseline in 1990 was the strongest determinant of being a smoker in 2003. Allergic sensitization and clinically verified asthma were not associated with smoking habits in 2003. No differences in changing smoking habits could be identified between smokers with or without asthma. In conclusion, modifiable lifestyle factors are important risk factors for adult onset asthma. The co-occurrence and interplay between asthma and cigarette smoking is still puzzling.

Abstract Dental caries in toddlers was studied in relation to several risk factors which were also determined by salivary tests in a longitudinal design. Another specific aim was to reveal the effect of prolonged pacifier sucking on caries development. The study population consisted of 183 pre-school children. At the baseline, salivary microbiological tests were taken from children whose average age was 2.5 years. Risk factors for colonisation of salivary lactobacilli and yeasts were determined from a questionnaire filled in by the parents. At the 2-year follow-up, caries in primary teeth was studied against the possible risk factors recorded at the baseline. At the 7-year follow-up, the risk factors identified at the age of two were analysed against caries development in primary molars and in first permanent molars. Also the long-term predictive value of salivary microbiological tests was investigated. At the baseline, the use of pacifier and nocturnal use of nursing bottle were associated with colonisation of salivary lactobacilli and yeasts. Prolonged pacifier sucking and use of nursing bottle at nights were shown to be associated with caries development in children at the 2-year follow-up. Consumption of sweets, lack of daily tooth brushing and nocturnal use of nursing bottle at the age of two were associated with caries onset in both primary and permanent molars at the seven-year follow-up. The use of fluoride tablets reduced the risk of caries onset in primary molars. Children who were colonised by salivary lactobacilli or yeasts at the baseline were susceptible to caries in primary molars. Early colonisation of lactobacilli was associated with caries in permanent molars. The results suggest that the risk of caries is possible to assess in toddlers by identifying caries-related habits early, already at the age of two. Microbiological tests may also have some value. Assessment of caries risk in toddlers enables both prevention and early intervention, and thereby prevention of caries development in children
Tiivistelmä Tämän tutkimuksen tarkoituksena oli pitkäaikaisseurannassa selvittää taaperoikäisiltä lapsilta otettujen sylkitestien ja muiden määritettyjen riskitekijöiden mahdollista yhteyttä karieksen kehittymiseen. Erityisesti haluttiin myös tutkia pitkittyneen tutin käytön merkitystä. Tutkimusaineisto koostui 183:sta alle kouluikäisestä lapsesta. Aloitusvaiheessa otettiin mikrobiologiset sylkitestit lapsilta, joiden keski-ikä oli 2,5 vuotta, ja määritettiin anamnestisesti mahdolliset riskitekijät laktobasillien ja hiivasienten kolonisaatiolle. Kahden vuoden seurannan jälkeen tutkittiin riskin toteutumista maitohampaiden karioitumisessa. Seuraavassa seitsemän vuoden seurantatutkimuksessa tutkittiin karieskehitystä maitomolaareissa ja ensimmäisissä pysyvissä molaareissa kahden vuoden iässä määritetyissä riskiryhmissä. Myös syljen mikrobiologisten testien avulla määritetyn riskin toteutumista selvitettiin seitsemän vuoden seurannan päätyttyä. Tutkimuksen aloitusvaiheen sylkitestitulokset osoittivat, että tutin käyttö ja tuttipullon käyttö öisin olivat yhteydessä syljen kariekseen liittyviin mikrobeihin, ja ne voivat siten lisätä kariesaktiivisuutta maitohampaistossa. Kahden vuoden seurantatutkimuksessa todettiinkin, että karieskehitys oli yhteydessä aikaisemmin määritettyihin riskitekijöihin: pitkittyneeseen tutin käyttöön ja tuttipullon käyttöön öisin. Seitsemän vuoden seurantatutkimuksen tulokset osoittivat, että makeisten käyttö kaksivuotiaana, puutteellinen hampaiden harjaus ja tuttipullon käyttö öisin ovat riskitekijöitä sekä maitomolaarien että ensimmäisten pysyvien molaarien karieskehitykselle. Fluoritablettien käyttö vähensi maitomolaarien karioitumista. Myös varhain tehdyillä syljen mikrobiologisilla testeillä oli pitkäaikainen ennustusarvo. Tulokset osoittavat, että riskin määritys taaperoikäisten lasten karieskehitykselle voidaan tehdä varhaisessa vaiheessa sekä mikrobiologisten sylkitestien avulla että määrittelemällä muiden mahdollisten riskitekijöiden esiintyvyys. Varhaisen kariesriskin määrityksen avulla voidaan ehkäisevät hoitotoimenpiteet kohdistaa ajoissa riskiryhmille ja siten ehkäistä karieskehitystä ja korjaavan karieshoidon tarvetta lapsilla

This thesis investigates emblem use exploratory in parent-child interaction. Emblems are conventional gestures with a verbal equivalent. The aim of this study was to answer if emblem use facilitates language acquisition. Formulaic gestures – fixed gestures accompanying songs – were examined as a subgesture of emblems. 20 children and their parents’ emblem use were recorded when interacting freely at seven age points: 6, 9, 12, 15, 18, 21 and 24 months. Emblem use was correlated to the children’s productive vocabulary at 30 months. The results showed that parental emblem use at 24 months and child emblem use at 15 months predicted child productive vocabulary at 30 months. T-tests showed how emblem production of children in a lower productive vocabulary group differed from children in a higher productive vocabulary group. A difference between the children of the lower productive vocabulary group and the children of the higher productive vocabulary group emblem use was also found at 15 months, indicating emblem use being important in language acquisition. Formulaic gestures did not correlate to child productive vocabulary. Emblem use developed along with child age and probably inherently with word production. Parents adjust their emblem use to the child’s age and/or possibly language skills, suggesting that child-directed gesturing occurs in parent-child interaction.
Den här studien undersöker emblemanvändning explorativt i förälder-barninteraktion. Emblem definieras som konventionella gester med en verbal motsvarighet. Målet i denna studie var att undersöka om emblemanvändning underlättar språktillägnande. Fasta gester – gester tillhörande sånger – undersöktes som en underkategori till emblem. 20 barn och deras föräldrar spelades in när de interagerade fritt vid sju ålderspunkter: 6, 9, 12, 15, 18, 21 och 24 månader vilket också korrelerades med barnets produktiva ordförråd vid 30 månader. Resultaten visade att föräldrars emblemanvändning vid 24 månader och barns emblemanvändning vid 15 månader korrelerade med barnens ordförråd vid 30 månader, vilket indikerar att emblemanvändning vid dessa ålderspunkter förutsäger ordförrådets storlek några månader senare. T-tester visade att emblemproducering hos barn skiljde sig åt mellan gruppen med barn med lägre produktivt ordförråd och gruppen med barn med högre produktivt ordförråd. Vid 15 månader fanns också en signifikant skillnad mellan grupperna vilket indikerar att emblem spelar en viktig roll vid språktillägnandet. Fasta gester visade ingen korrelation med barnets språkutveckling. Barnens emblemproduktion utvecklades med åldern och troligtvis tillsammans med ordproduktion. Föräldrar verkar justera sitt emblemanvändande till barnets ålder och/eller språkkunskaper, vilket indikerar att ett barnriktat gestikulerande finns vid förälder-barn interaktion.
Modelling child language acquisition from parent-child interaction (MINT: MAW 2011:007)

This study follows incoming freshmen students for three semesters, tracking their GPA along with several psychological constructs. Theory of Intelligence, Performance Goals, Learning Goals, Confidence in Intelligence, Campus Connectedness, Sense of Belongingness: Antecedents, School Coherence, Leadership, and Followership were assessed. Results are discussed for each semester, along with the three-semester differences in scores and GPA. Retention is addressed in correlation with the measures.