Li, Yun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 68-72). / Abstracts in English and Chinese. / Abstract --- p.I / 摘要 --- p.III / Acknowledgments --- p.IV / List of Contents --- p.VI / List of Figures --- p.VII / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Visual Detection --- p.2 / Chapter 1.2 --- Irregularity Detection --- p.4 / Chapter Chapter 2 --- System Overview --- p.7 / Chapter 2.1 --- Definition of Irregularity --- p.7 / Chapter 2.2 --- Contributions --- p.8 / Chapter 2.3 --- Review of previous work --- p.9 / Chapter 2.3.1 --- Model-based Methods --- p.9 / Chapter 2.3.2 --- Statistical Methods --- p.11 / Chapter 2.4 --- System Outline --- p.14 / Chapter Chapter 3 --- Background Subtraction --- p.16 / Chapter 3.1 --- Related Work --- p.17 / Chapter 3.2 --- Adaptive Mixture Model --- p.18 / Chapter 3.2.1 --- Online Model Update --- p.20 / Chapter 3.2.2 --- Background Model Estimation --- p.22 / Chapter 3.2.3 --- Foreground Segmentation --- p.24 / Chapter Chapter 4 --- Feature Extraction --- p.28 / Chapter 4.1 --- Various Feature Descriptors --- p.29 / Chapter 4.2 --- Histogram of Oriented Gradients --- p.30 / Chapter 4.2.1 --- Feature Descriptor --- p.31 / Chapter 4.2.2 --- Feature Merits --- p.33 / Chapter 4.3 --- Subspace Analysis --- p.35 / Chapter 4.3.1 --- Principal Component Analysis --- p.35 / Chapter 4.3.2 --- Subspace Projection --- p.37 / Chapter Chapter 5 --- Bayesian Probabilistic Inference --- p.39 / Chapter 5.1 --- Estimation of PDFs --- p.40 / Chapter 5.1.1 --- K-Means Clustering --- p.40 / Chapter 5.1.2 --- Kernel Density Estimation --- p.42 / Chapter 5.2 --- MAP Estimation --- p.44 / Chapter 5.2.1 --- ML Estimation & MAP Estimation --- p.44 / Chapter 5.2.2 --- Detection through MAP --- p.46 / Chapter 5.3 --- Efficient Implementation --- p.47 / Chapter 5.3.1 --- K-D Trees --- p.48 / Chapter 5.3.2 --- Nearest Neighbor (NN) Algorithm --- p.49 / Chapter Chapter 6 --- Experiments and Conclusion --- p.51 / Chapter 6.1 --- Experiments --- p.51 / Chapter 6.1.1 --- Outdoor Video Surveillance - Exp. 1 --- p.52 / Chapter 6.1.2 --- Outdoor Video Surveillance - Exp. 2 --- p.54 / Chapter 6.1.3 --- Outdoor Video Surveillance - Exp. 3 --- p.56 / Chapter 6.1.4 --- Classroom Monitoring - Exp.4 --- p.61 / Chapter 6.2 --- Algorithm Evaluation --- p.64 / Chapter 6.3 --- Conclusion --- p.66 / Bibliography --- p.68

abstract: College students are a niche of young adults, characterized by abnormal sleeping habits and inactive lifestyles. Many students entering college are as young as 18 years old and graduate by 22 years old, a window of time in which their bones are still accruing mineral. The purpose of this cross-sectional study was to determine whether sleep patterns and physical activity observed in college students (N= 52) 18-25 years old at Arizona State University influenced bone biomarkers, osteocalcin (OC) and N-terminal telopeptide of type 1 collagen (NTX-1) concentrations. Students completed various dietary and health history questionnaires including the International Physical Activity Questionnaire short form. Students wore an actigraphy watch for 7 consecutive nights to record sleep events including total sleep time, sleep onset latency and wake after sleep onset. Total sleep time had a significant, negative correlation with OC (r = -0.298, p-value =0.036) while sleep onset latency had a significant, positive correlation with NTX-1 serum concentration (r = 0.293, p-value = 0.037). Despite correlational findings, only sleep percent was found to be significant (beta coefficient = 0.271 p-value = 0.788) among all the sleep components assessed, after adjusting for gender, race, BMI and calcium intake in multivariate regression models. Physical activity alone was not associated with either bone biomarker. Physical activity*sleep onset latency interactions were significantly correlated with osteocalcin (r = 0.308, p-value =0.006) and NTX-1 (r = 0.286, p-value = 0.042) serum concentrations. Sleep percent*physical activity interactions were significantly correlated with osteocalcin (r = 0.280, p-value = 0.049) but not with NTX-1 serum concentrations. Interaction effects were no longer significant after adjusting for covariates in the regression models. While sleep percent was a significant component in the regression model for NTX-1, it was not clinically significant. Overall, sleep patterns and physical activity did not explain OC and NTX-1 serum concentrations in college students 18-25 years old. Future studies may need to consider objective physical activity devices including accelerometers to measure activity levels. At this time, college students should review sleep and physical activity recommendations to ensure optimal healthy habits are practiced. / Dissertation/Thesis / Masters Thesis Nutrition 2019

Abstract This thesis studies the long-term evolution of the photospheric magnetic field using surface flux transport simulations. The photospheric magnetic field and magnetic activity are tightly connected to space weather, and affect the whole heliosphere including the Earth. However, due to a lack of reliable observations our understanding of the long-term evolution of the photospheric magnetic field is still poor. Surface flux transport models, which are capable of simulating the evolution of the whole surface field from observations of solar activity, can be used to study the field in times when direct observations are not available. In this thesis we validate our surface flux transport model, optimize its parameters and test its sensitivity to uncertainties in parameter values and input data. We find a need to extend the model with a decay term to properly model the deep and long minimum between solar cycles 23 and 24, and simulate the photospheric magnetic field of cycles 21–24 using magnetographic observations as input. We also study consequences of hemispherically asymmetric activity, and show that activity in one hemisphere is enough to maintain polar fields in both hemispheres through cross-equatorial flow of magnetic flux. We develop a new method to reconstruct active regions from calcium K line and sunspot polarity observations. We show that this reconstruction is able to accurately capture the correct axial dipole moment of active regions. We study the axial dipole moments of observed active regions and find that a significant fraction of them have a sign opposite to the sign expected from Hale’s and Joy’s laws, proving that the new reconstruction method has an advantage over existing methods that rely on Hale’s and Joy’s laws to define polarities. We show one example of a long simulation covering solar cycles 15–21, demonstrating that using the active region reconstruction and surface flux transport model presented in this thesis it is possible to simulate the large-scale evolution of the photospheric magnetic field over the past century. / Original papers The original publications are not included in the electronic version of the dissertation. Virtanen, I. O. I., Virtanen, I. I., Pevtsov, A. A., Yeates, A., & Mursula, K. (2017). Reconstructing solar magnetic fields from historical observations. II. Testing the surface flux transport model. Astronomy & Astrophysics, 604, A8. https://doi.org/10.1051/0004-6361/201730415 http://jultika.oulu.fi/Record/nbnfi-fe2017103050356 Virtanen, I. O. I., Virtanen, I. I., Pevtsov, A. A., & Mursula, K. (2018). Reconstructing solar magnetic fields from historical observations. III. Activity in one hemisphere is sufficient to cause polar field reversals in both hemispheres. Astronomy & Astrophysics, 616, A134. https://doi.org/10.1051/0004-6361/201732323 http://jultika.oulu.fi/Record/nbnfi-fe201902205813 Virtanen, I. O. I., Virtanen, I. I., Pevtsov, A. A., Bertello, L., Yeates, A., & Mursula, K. (2019). Reconstructing solar magnetic fields from historical observations. IV. Testing the reconstruction method. Astronomy & Astrophysics, 627, A11. https://doi.org/10.1051/0004-6361/201935606 http://jultika.oulu.fi/Record/nbnfi-fe2019091828628 Virtanen, I. O. I., Virtanen, I. I., Pevtsov, A. A., & Mursula, K. (2019) Axial dipole moment of solar active regions in cycles 21-24. Manuscript.

Background: It is well established throughout the literature that regularly engaging in physical activity throughout pregnancy is associated with optimized health outcomes for both the mother and the fetus. The mediators and mechanistic pathways through which these observed exercise-induced outcomes are achieved are largely unknown. This thesis attempts to address this gap in knowledge. Methods: The objective of the first study was to develop an exercise protocol based on the recommendations from the ‘2019 Canadian guideline for physical activity throughout pregnancy’ and to subsequently evaluate the myokine response post-exercise. Pregnant (n=13) and non-pregnant (n=17) women performed a moderate-intensity bout of treadmill walking following which pre- and post-exercise serum for a panel of ten well-characterized myokines was analyzed. The objective of the second study was to evaluate whether acute and/or chronic exercise elicited changes in metrics of placental growth and development – thereby proposing possible mechanisms through which physical activity may be conferring health benefits to the fetus. Serum (pre- and post-exercise) collected from the first study was used to treat placental cell lines to assess the effect of acute exercise on cellular proliferation as well as nutrient transporter (GLUT1, SNAT1, FATP4) expression and localization. Term placental tissue collected from active (n=10) and non-active (n=10) participants in the PLACENTA study were used to evaluate the role of chronic exercise on changes in nutrient transporter (GLUT1, SNAT1, FATP4) expression and localization. Results: Pregnant women from the first study exhibited higher levels of four myokines post- versus pre-exercise: FGF21, EPO, BDNF and IL-15. As for the second study, BeWo cell lines treated with serum collected from pregnant women yielded higher GLUT1 expression compared to non-pregnant serum, independently of exercise. Lastly, FATP4 expression was found to be higher in term placentas of active compared to non-active pregnant women. Conclusion: This thesis identified four myokines that are elevated in the serum of pregnant women following a bout of acute exercise. The role of these myokines in pregnancy remains to be elucidated. Further, chronic and acute exercise are shown to alter expression of key placental macronutrient transporters.

Secreted by adipose tissue, leptin acts as a signal of energy reserve status, and acts in the brain as a negative feedback mechanism to suppress food intake and increase energy expenditure, the net effect of which is maintenance of energy homeostasis. In addition to its role as a satiety factor, leptin has widespread autonomic effects, increasing sympathetic tone to a variety of tissues, including those involved in arterial pressure regulation. Thus, leptin has been implicated as a critical link between obesity and hypertension. However, the specific mechanisms whereby leptin elicits its diverse effects are not fully understood. This is further complicated by the many sites of leptin action within the brain, as well as its diverse intracellular effects. Here, we investigate the possibility that distinct aspects of leptin function are controlled by different neuronal populations and/or molecular signaling cascades. Specifically, we identify unique roles for leptin action on POMC and AgRP neurons in differentially mediating the regional sympathetic effects of leptin. Furthermore, we show that leptin action via mTORC1 is required for the cardiovascular sympathetic but not the metabolic effects. Together, these findings point to complex neuroanatomical and molecular differences in the mechanisms underlying leptin’s effects on different physiological processes, with important implications for future research into obesity-associated hypertension.

Childhood obesity is a worldwide epidemic. In the United States, approximately 17% of adolescents are obese; and 13% of the general population is overweight. Obese adolescents are at threefold risk for developing chronic health conditions in adulthood, including type II diabetes, hypertension, and heart disease. The purpose of this project was to evaluate the results of a quality improvement program to reduce adolescent obesity as measured by BMI 5% over 18 months in a rural health primary care clinic. The health belief model and theory of planned behavior guided the project as adolescents need to first understand the risks associated with obesity and the benefits derived from a healthier lifestyle Then, they can be prepared to engage in regular exercise and good eating behaviors. A convenience sample of 100 adolescents was randomly assigned to an intervention group with structured physical activity regimen and dietary education classes and a standard care group with normal counseling. Two separate one-sided t tests with 90% confidence intervals were used to analyze the data. Also, run charts were constructed to assess the effectiveness of the program. The result of the t test revealed the weight for the intervention group at 18 months (M = 42.85, SD = 0.79) was significantly lower than it was for those in the non-intervention group (M = 45.06, SD = 0.59), t(36) = -9.79, p < 0.01. Furthermore, the run charts demonstrate the average BMI for those in the interventional group steadily decreased over 18 months while the non-intervention group steadily increased. Positive social change was achieved at the organization level as adolescent obesity was reduced with the evidence-based interventions. This project serves as a potential model for replication in other rural health primary care clinics.

The purpose of this study was t o examine the relationship between the types o f activities people engage in after they retire, how often they participate , how or with whom they participate , and how these independent variables influence the dependent variable of life satisfaction. The majority of the research done to date on postretirement activity focuses primarily on recreational activities. This study examined the effects of including some type of substantive or service activity in addition to hobbies and recreational act i vity. Participants were surveyed concerning their health, mobility, and financial conditions so that these variables could be controlled for in determining life satisfaction. They were questioned about their activities, and given the Life Satisfaction Index to measure life satisfaction. The results indicate that those who have no activities t hat they participate in on a regular basis--no hobbies, no forms of recreation , and no service-related activities-have a relatively high level of life satisfaction. Also those who have a high level of hobby and recreational activity combined with regular service activities have a higher level of satisfaction. Those who only occasionally engage in hobby and recreational activity and have no service-related activity have a moderate level of satisfaction. The results of this study confirm the hypothesis that life satisfaction is positively influenced by both hobbies and service activities. Age and gender of respondents are not important variables, but the issues of mobility, health, and economic status do impact life satisfaction. The importance of hobby and recreational activity has been frequently studied under the guise of activity theory, and found to be of significance in feelings of well-being and in life satisfaction. The role of service activity has not been thoroughly explored, but is believed to fill the need for exchange as postulated in exchange theory.

There are few data available regarding the relationship between physical activity and veteran status in those with combined chronic obstructive pulmonary disease (COPD) and obesity. COPD is a common illness and a leading cause of death in the United States. Veterans represent a distinct subpopulation in the United States and are more likely to have COPD, which is a disease with a high rate of comorbidities such as obesity. Physical activity can improve outcomes for those with COPD and obesity. However, recommendations for physical activity for those with COPD and obesity are vague. This study, based on the self-determination theory, sought to explore the relationship between average weekly physical activity and veteran status while controlling for age, sex, race, ethnicity, smoking status, body mass index (BMI), education level, and annual household income in those with comorbid COPD and obesity. Also, the relationship between not meeting, meeting, and exceeding physical activity recommendations and veteran status, while accounting for variation in for age, sex, race, ethnicity, smoking status, BMI, education level, and annual household income, was explored. A case-control study was done to answer the research questions using multiple regression and ordinal regression analyses, respectively, using data from 1,430 participants from the 2015 BRFSS. Veteran status was not significantly associated with physical activity nor was it significantly associated with falling below, at, or above recommended physical activity amounts. However, it was found that increased BMI was associated with decreased physical activity. The results from this study can be used to inform policies, refine recommendations, and guide interventions for those with COPD and obesity.

Rural adults engage in less physical activity and are less likely to meet activity recommendations than urban or suburban adults. Understanding determinants of this behavior can help design interventions for increasing activity levels. This series of studies examined the perceived determinants of physical activity in the social, physical, and policy environments of rural adults, using the following aims: Aim 1: A secondary analysis was conducted of a cross-sectional survey among 407 adults from two rural towns to examine determinants of physical activity separately by the domain in which this behavior occurs (i.e. home care, active living, etc.). Multiple regression analyses found that social characteristics (such as support from friends), policy attitudes (such as workplace incentives for exercise), and physical environmental factors (such as an activity-friendly neighborhood) were positively associated with total physical activity, active living, and sport. Barriers were negatively associated with these domains. No factors were associated with physical activity in work or home care. Physical activity determinants are specific to the domain of physical activity, and more research needs to be done to determine factors associated with physical activity in home or work. Aim 2: Measurement tools should be culturally relevant to a specific population for accurate measurement. Three focus groups were conducted (n=19) in a rural Midwestern county to tailor existing measurement tools to this population. Focus group members were asked about the activities they engaged in and facilitators and barriers to those activities. Important factors associated with physical activity include social support and modeling active behavior. Focus group members desired to see community buildings be open to the public for exercise. This study revealed contextual issues and cultural language for tailoring physical activity measurement tools for rural adults. Aim 3: Ecological models propose that the environment impacts behavior on several different levels. Using a tailored survey instrument, this study examined social, environmental, and policy-level determinants of physical activity at different levels of an ecological approach. A cross-sectional survey was given to 143 individuals residing in a rural Midwestern county. Test-retest reliability was examined using correlations and kappa statistics, and was found to be very good to substantial. Multiple regression analyses were conducted using general linear modeling. Social factors were associated with total physical activity; environmental factors were associated with active transport, house and yard work, vigorous activity, and walking; and policy factors were associated with physical activity at work, and moderate-intensity activity. Findings can be used to tailor physical activity interventions using an ecological approach in rural adults, based on the specific domain and intensity in which the activity occurs. These studies provide insight into the contextual factors that are associated with physical activity in rural Midwestern adults, and provide evidence that determinants should be examined and presented by the domain and intensity in which this behavior occurs. It is clear that social and physical environments and policy attitudes are associated with domain- and intensity-specific physical activity in this population.

Factors influencing language development and use are many. Teacher influences such as teacher:child ratio and teaching experience can affect the types of language children produce. Classroom influences including activities , size of the room, and length of the day also play a role in the development of language. All of these areas need to be considered in order to provide the best possible language environment for the preschool child. In this study, the researchers examined the mean length of utterance (MLU) values of preschool children while participating at three areas in a preschool classroom : art, dramatic play, and snack. Gender differences in MLU were also studied. Sixteen children (8 females, 8 males), ranging in age from 50 to 66 months, participated in the study . The children were currently attending the Child Development Laboratory at Utah State University. For the collection of data , the children wore a tape recorder with a microphone until a 5-minute sample from each of the areas was obtained . These audio recordings were then transcribed and calculated into MLU values. Findings from the analysis of variance tests (3[activity : art , dramatic p l ay, snack] X 2 [gender: male , female]) demonstrated that the children had larger MLU values at snack than at art or dramatic play. Snack time has not always been recognized as an activity area for young children to display typical language use. Overall , and at the three individual areas , there were no gender differences found in MLU. Results of this study may be used in planning how to arrange and organize an environment in which the children are comfortable and have opportunities to converse with both adults and other children.