The importance of individual differences in psychological responses to loss and potential trauma is well-established, yet previous approaches have been limited in capturing and explaining the full scope of variation. The present studies expanded on this line of research to elucidate key aspects of the risk and protective processes that influence psychological adaptation to loss and trauma. The first set of studies examined the influence of emotion regulation choice sensitivity on the relationship between potentially traumatic events (PTEs) and posttraumatic stress disorder (PTSD) in veterans and nonveterans. In the veteran sample, choice sensitivity was found to be a moderator that reduced the impact of PTE exposure on PTSD symptoms. Choice sensitivity similarly functioned as a moderator in the nonveteran sample, however the effects were contingent on both the type of PTE exposure and the outcomes associated with implementation of the selected regulation strategies. The second set of studies investigated risk and protective factors in the face of spousal loss. Random-intercept cross-lagged panel modeling was employed to examine and clarify the nature of the relationships between key factors and depression across an 8-year period. Factors included optimism, sense of control, religiosity, and social support while the primary bereavement outcome was depression symptoms. Distinct patterns of risk and protective processes were identified in relation to all factors that involved clearly differentiable stable, between-subjects effects and time-varying, within-subjects effects. The third set of studies addressed whether resilience would extend across multiple domains of positive adjustment in the context of spinal cord injury, bereavement, and heart attack. Relationships between symptom-based trajectories of resilience and positive adjustment in psychological, social, and health-related domains were examined. Individuals who exhibited trajectories of resilience in relation to depression symptoms simultaneously experienced better positive adjustment, functioning, and health in areas that included quality of life, perceived manageability, anxiety, self-esteem, social integration, cognition, and body mass index.

Research has shown that exposure to green, natural environments can help the body recover from stress. Because of this effect, stress alleviation is considered an ecosystem service provided by nature for the benefit of human health and well-being. But is this effect equal when viewing natural environments with different levels of biodiversity? For example, is a natural forest with higher visual biodiversity better at alleviating stress than a low biodiversity spruce plantation, or an urban city? This question was tested in an experiment using virtual reality (VR). Test participants (n=31) were divided into three groups, induced with stress from a stressor, and then exposed to images of either natural forest, spruce plantation, or urban city in VR. Heart rate (HR), heart rate variability (HRV), and skin conductance level (SCL) were used as physiological measurements for stress. SCL and HR showed a significant decrease in stress for the natural forest, but not in the spruce plantation or the urban city. The results for HRV were inconclusive. The results suggest that the stress alleviation is stronger when exposed to a natural forest, indicating that visual experience of biodiversity may have an important role in stress alleviation, and further stress its value as an ecosystem service.

The most active form of Vitamin D, 1alpha,25(OH)2D3, modulates cells via receptor mediated mechanisms. While studies have elucidated the pathway via the classical nuclear Vitamin D Receptor (VDR), little is known about the membrane-associated Vitamin D Receptor (ERp60). Caveolae and its characteristic protein Caveolin-1 have been involved in many signaling pathways due to its specific structure and physical configuration. Other studies have shown that many components of the Vitamin D pathway have been found in caveolae. This study hypothesizes that caveolae and Caveolin-1 are important for the effects of 1,25 Vitamin D signaling via ERp60. Research up to date have shown that in rat and mouse growth zone chondrocytes, cells deprived of intact caveolae either through disruption through beta-Cyclodextrin or genetic knockout do not exhibit the characteristic responses to Vitamin D through ERp60 when compared to chondrocytes with functional caveolae. Studies using immunofluorescence co-localization and caveolae fractionation have shown that ERp60 is localized in the caveolae domains. Cellular fractionation was also performed to examine the localization of the ERp60 receptor in lipid rafts and caveolae. Histology and transmission electron microscopy were also used to examine the physiological importance of caveolae and Caveolin-1 in growth plate morphology and cellular characteristics.

This thesis is concerned with a very common disorder of iron homeostasis: iron deficiency. The specific focus is the manner in which iron deficiency influences physiological responses to hypoxia in humans. This work is predicated on observations made over many decades in vitro and in vivo, suggesting that variations in the bioavailability of iron have important consequences for certain biological processes known to depend on oxygen availability. Three separate but related studies together form the basis for this thesis. The first two, Study A and Study B, adopt a similar approach in recruiting healthy volunteers who differ according to iron status, yielding iron-deficient and iron-replete groups in both cases. In Study A, the behaviour of the pulmonary circulation is investigated during a sustained hypoxic exposure, before and after an intravenous infusion of iron. In Study B, skeletal muscle metabolism is explored, both at the level of high-energy phosphate metabolism and the integrated physiological responses to exercise on a cycle ergometer. In the third study, Study C, a different approach is taken, recruiting patients with chronic obstructive pulmonary disease (COPD), and exploring the prevalence and associations of iron deficiency in this condition. Chapters 2 and 3 describe experiments using sustained hypoxia in a normobaric chamber, during which the pulmonary circulation is assessed non-invasively using Doppler echocardiography. These reveal augmented hypoxic pulmonary vasoconstriction (HPV) in iron-deficient individuals, who also exhibit greater sensitivity to the effects of an infusion of intravenous iron. Additionally, the way in which certain circulating mediators important for iron haemostasis change over the course of these hypoxic exposures, and how iron status influences these responses, is explored. Chapter 4 reports the findings of experiments using 31P-magnetic resonance spectroscopy and cardiopulmonary exercise testing, which demonstrate abnormal whole-body metabolism in iron-deficient individuals during large muscle-mass exercise, despite the absence of a clear defect in mitochondrial oxidative phosphorylation. Intravenous iron is found to have significant effects to alter the lactate threshold in healthy individuals, but the effects are more striking in iron-deficient individuals. Collectively, these experiments imply that iron deficiency promotes a more glycolytic phenotype. Chapter 5 explores iron deficiency in COPD, a condition in which pulmonary vascular disease, hypoxia and skeletal muscle dysfunction coexist, and examines some of the difficulties in assessing iron status in the setting of a chronic inflammatory disorder. Iron deficiency is found to be common, and unexpectedly associated with significantly more severe hypoxaemia, in patients with COPD. Possible reasons for these findings, and their clinical implications, are considered. Chapter 6 provides a summary of the main conclusions to be drawn from the studies presented in this thesis.

The aim of this doctoral thesis is to appraise the efficiency of inquiry-based education in biology (IBSE, inquiry-based science education) and to compare this efficiency with the efficiency of the tuition that uses traditional teaching methods, during the schooling of chosen themes from the human physiology, on different educational levels in the Czech Republic. For the purpose of monitoring the efficiency of both educational attitudes, there were drawn up pretests and posttests. Thanks to them, the level of involved pupils' and students' knowledge of contents and skills, was measured before and subsequently after the application of inquiry based tasks to the laboratory classes. The variety of inquiry based tasks that met the requirements of IBSE, that focused on chosen topics from the human physiology and that complied with the knowledge and age of the given group, was made for the research purpose. The research was realized with elementary school pupils, grammar school pupils and university students. In the lump, there were 145 pupils from the elementary school and grammar school and 168 university students. Pupils and students were divided into the experimental groups, where they solved task with the elements of IBSE, and to the groups with traditional teaching. Conclusions of the researches that were based on the comparing of pupils and students success rate in pretests and posttest showed, the IBSE led to the better knowledge acquirement. But in the comparison with the results of pupils and students from the traditional teaching groups, the improvement was not statistically significant. It was discovered that IBSE leads to the significantly more effective acquirement of science skills (e.g. assessment and suggestion of the science research, design of the scientific and research questions, data interpretation and making of appropriate conclusions). The efficiency was influenced by the educational level (i.e. by the age of involved pupils and students and by the type of school) this approach was the most effective in grammar schools. Given research proves that the application of the IBSE to the teaching of human physiology presents felicitous innovation in the science education. In view of the fact that it leads to the identical or better knowledge adoption and it also significantly develops pupils' and students' scientific skills.

This thesis is concerned with the role of iron in modulating right ventricular (RV) afterload during exercise in healthy people aged between 50 and 80 years. This is predicated on the requirement of the hypoxia-inducible factor (HIF) pathway for ferrous iron. A secondary objective is to examine the reactive oxygen species (ROS) hypothesis in human hypoxic pulmonary vasoconstriction (HPV) using exposure to hyperoxia. Chapters 3 and 4 describe basal relationships that may affect the HIF pathway and exercise capacity during ageing. These were explored in 113 participants using blood tests and exercise tests. Age and inflammatory factors, C-reactive protein, and ferritin were associated with impaired exercise capacity. In addition, ageing did not significantly affect haematological variables or iron status indicators. Chapters 5 and 6 describe the effect of a single intravenous iron infusion on the haematological variables in 32 participants in a randomised, placebo-controlled and double-blinded study. The effects of iron infusion on RV afterload during light exercise, and exercise capacity during heavy exercise, were examined in these participants. With iron infusion, erythropoietin production, and the increase in RV afterload during light exercise were blunted, potentially indicating involvement of the HIF pathway. However, blunting of RV afterload neither influenced the cardiac output during light exercise nor exercise capacity. Chapter 7 describes a study of 11 healthy volunteers, which investigated the ROS hypothesis in HPV using acute isocapnic hypoxia following an 8-hour exposure to hyperoxia. This sustained hyperoxic exposure did not influence the hypoxic behavior of the pulmonary vasculature. This thesis demonstrates the complex relationship between iron status and exercise capacity in older adults. It shows that the decrease in RV afterload during exercise caused by intravenous iron supplementation does not lead to an augmented cardiac output or exercise capacity. Finally, it calls into question the role of ROS in HPV.

A human thermoregulation model has been adapted for predicting the thermal response of Typical Older Persons. The model known as the Older Persons Model predicts the core body temperature and regulatory responses of the older people in environmental exposures of cold, warm and hot. The model was developed by modifying an existing dynamic human thermoregulation model using anthropometric and thermo-physical properties of older people. The Model defines the body as two interrelating systems of the body structure (passive system) and the control system of the central nervous system (active system). The Older person's passive system of the model was developed by meticulously extracting relevant experimental data from selected published research works relating to anthropometric and thermo-physical properties of older people. The resultant body structure (passive system) is a multi-segmented representation of a Typical Older Person. The active system (central nervous system) was developed by the application of a novel optimization method based on the working principles of Genetic Algorithms. The use of Genetic Algorithm enables the complex characteristics of the central nervous system of the older persons to be well represented and evaluated based on available data. Active system control signal coefficients for sweating, shivering, vasodilation and vasoconstriction were explicitly derived based on experimental data sourced from literature. The Older Persons Model has been validated using independent experimental data and its results show good agreement with measured data. Furthermore, the Older Persons Model has been applied to several test cases extracted from published literature and its results show good agreement with published findings on the thermal behaviour of older persons. An interview study conducted as part of this research revealed that, professionals (built environment specialists) found the Older Persons Model useful in assisting to further understand the thermal response of the older persons. In conclusion, the adaptation of an existing human thermoregulation model has resulted in a new model, which allows improved prediction of heat and cold strain of the older person although there exist limitations.

Text in English / The purpose of the study was to describe the perceptions and attitudes of student nurses towards anatomy and physiology. The study was conducted in the nursing education setting at three campuses of one college of nursing in the Limpopo Province of South Africa. A non-experimental, quantitative, descriptive research design was utilised, with a survey and a self-administered questionnaire as data collection method and instrument respectively. Probability sampling was utilised to select a sample of 2nd year student nurses registered for the 4-year diploma at the selected college of nursing. Data was analysed by means of Statistical Package of Social Sciences (SPSS) version 24.0. The results revealed both positive and negative perceptions and attitudes towards anatomy and physiology. Positive attitudes and perceptions were that the subject is enjoyable, easy, interesting and relevant to nursing practice. Negative attitudes were shown towards the classroom as not being conducive to learning and towards teaching methods that were not interactive. Recommendations were made to include interactive, evidence-based teaching learning methods in anatomy and physiology. / Health Studies / M. A. (Nursing Science)

Tissue engineering is a promising alternative strategy to produce artificial bone substitutes / however, the control of the cell organization and cell behavior to create fully functional 3-D constructs has not yet been achieved. To overcome these, activities have been concentrated on the development of multi-functional tissue engineering scaffolds capable of delivering the required bioactive agents to initiate and control cellular activities. The aim of this study was to prepare tissue engineered constructs composed of polymeric scaffolds seeded with mesenchymal stem cells (MSCs) carrying a nanoparticulate growth factor delivery system that would sequentially deliver the growth factors in order to mimic the natural bone healing process. To achieve this, BMP-2 and BMP-7, the osteogenic growth factors, were encapsulated in different polymeric nanocapsules (poly(lactic acid-co-glycolic acid) (PLGA) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)) with different properties (degradation rates, crystallinity) and, therefore, different release rates to achieve the early release of BMP-2 followed by the release of BMP-7, as it is in nature. Initially, these nanoparticulate delivery systems were characterized and then the effect of single, simultaneous and sequential delivery of BMP-2 and BMP-7 from these delivery systems was studied in vitro using rat bone marrow MSCs. The effect of using these two growth factors in a sequential manner by mimicking their natural bioavailability timing was shown with maximized osteogenic activity results. BMP-2 loaded PLGA nanocapsules were subcutaneously implanted into Wistar rats and according to initial results, their biocompatibility as well as the positive effect of BMP-2 release on the formation of osteoclast-like cells was shown. To complete the construction of the bioactive scaffold, this nanoparticulate sequential delivery system was incorporated into two different types of polymeric systems / natural (chitosan) and synthetic (poly(&amp / #949 / -caprolactone) (PCL)). 3-D fibrous scaffolds were produced using these materials by wet spinning and 3-D plotting. Incorporation of nanocapsules into 3-D chitosan scaffolds was studied by two different methods: incorporation within and onto chitosan fibers. Incorporation into 3-D PCL scaffolds was achieved by coating the nanocapsules onto the fibers of the scaffolds in an alginate layer. With both scaffold systems, incorporation of nanocapsule populations capable of delivering BMP-2 and BMP-7 in single, simultaneous and sequential fashion was achieved. As with free nanocapsules, the positive effect of sequential delivery on the osteogenic differentiation of MSCs was shown with both scaffold systems, creating multi-functional scaffolds capable of inducing bone healing.

The purpose of this study was to determine the effects of 4 week respiratory muscle training (RMT) on intermittent recovery performance, pulmonary functions and maximum oxygen consumption capacity (Vo2max) of young soccer players. Eighteen young soccer player who were playing in the Turkey PAF League (league for candidate professional soccer players) from Hacettepe Sports Club with a mean age of 18.4 &plusmn / 0.8 years (ranging from 17 to 19 years) and 8.5 &plusmn / 0.7 (ranging from 7 to 9 years) years experience in soccer participated. Players&rsquo / weekly metabolic equivalent score (MET) was 120. Their maximum oxygen consumption (Vo2max) on a treadmill, pulmonary function with a spirometer, and recovery performance with a yo-yo intermittent recovery test level 2 were measured and then they were randomly assigned into two groups as either RMT (n = 9) or control (n = 9). The RMT group continued both their regular training and RMT treatment with a commercially available powerlung sport respiratory muscle trainer (Powerlung Inc., TX, and USA) for 4 weeks. The control group only continued with their regular training. After completing 4 week RMT implementation (composed of 30 sets of inhalation, two times a day, 5 days of the week), the same tests were performed in order to see the v effects of 4 week RMT treatment on selected parameters mentioned above. Findings of this study indicated that 4 week of RMT treatment significantly improved (% 39) yo-yo intermittent recovery test level 2 performances of the RMT group from pre to post test measurements when compared to subjects in the control group. However, there were no significant improvements in both RMT and control group&rsquo / s Vo2max capacity, Vital capacity (VC), Forced vital capacity (FVC), forced expiratory flow (FEV1.0) and Peak expiratory flow performances (PEF). As a conclusion, 4 week of RMT implementation improves the intermittent recovery performance of young soccer players.