660 resultados para factors evaluated
Resumo:
Despite significant investment in school one-to-one device programs, little is known about which aspects of program implementation work and why. Through a comparison of two implementation models, adopter-diffusion and saturation, and using existing data from the One Laptop per Child Australia laptop program, we explored how factors of implementation may affect device diffusion, learning and educational outcomes, and program sustainability in schools. In this article we argue that more focused research into implementation of one-to-one device programs, moving beyond comparisons of “devices versus without devices,” is needed to provide reliable data to inform future program funding and advance this area of research.
Resumo:
Child care centers differ systematically with respect to the quality and quantity of physical activity they provide, suggesting that center-level policies and practices, as well as the center's physical environment, are important influences on children's physical activity behavior. Purpose To summarize and critically evaluate the extant peer-reviewed literature on the influence of child care policy and environment on physical activity in preschool-aged children. Methods A computer database search identified seven relevant studies that were categorized into three broad areas: cross-sectional studies investigating the impact of selected center-level policies and practices on moderate-to-vigorous physical activity (MVPA), studies correlating specific attributes of the outdoor play environment with the level and intensity of MVPA, and studies in which a specific center-level policy or environmental attribute was experimentally manipulated and evaluated for changes in MVPA. Results Staff education and training, as well as staff behavior on the playground, seem to be salient influences on MVPA in preschoolers. Lower playground density (less children per square meter) and the presence of vegetation and open play areas also seem to be positive influences on MVPA. However, not all studies found these attributes to be significant. The availability and quality of portable play equipment, not the amount or type of fixed play equipment, significantly influenced MVPA levels. Conclusions Emerging evidence suggests that several policy and environmental factors contribute to the marked between-center variability in physical activity and sedentary behavior. Intervention studies targeting these factors are thus warranted.
Resumo:
Epithelial-mesenchymal transition (EMT) is a feature of migratory cellular processes in all stages of life, including embryonic development and wound healing. Importantly, EMT features cluster with disease states such as chronic fibrosis and cancer. The dissolution of the E-cadherin-mediated adherens junction (AJ) is a key preliminary step in EMT and may occur early or late in the growing epithelial tumour. This is a first step for tumour cells towards stromal invasion, intravasation, extravasation and distant metastasis. The AJ may be inactivated in EMT by directed E-cadherin cleavage; however, it is increasingly evident that the majority of AJ changes are transcriptional and mediated by an expanding group of transcription factors acting directly or indirectly to repress E-cadherin expression. A review of the current literature has revealed that these factors may regulate each other in a hierarchical pattern where Snail1 (formerly Snail) and Snail2 (formerly Slug) are initially induced, leading to the activation of Zeb family members, TCF3, TCF4, Twist, Goosecoid and FOXC2. Within this general pathway, many inter-regulatory relationships have been defined which may be important in maintaining the EMT phenotype. This may be important given the short half-life of Snail1 protein. We have investigated these inter-regulatory relationships in the mesenchymal breast carcinoma cell line PMC42 (also known as PMC42ET) and its epithelial derivative, PMC42LA. This review also discusses several newly described regulators of E-cadherin repressors including oestrogen receptor-α and new discoveries in hypoxia- and growth factor-induced EMT. Finally, we evaluated how these findings may influence approaches to current cancer treatment.
Resumo:
Introduction The benefits of physical activity are established and numerous; not the least of which is reduced risk of negative cardiovascular events. While sedentary lifestyles are having negative impacts across populations, people with musculoskeletal disorders may face additional challenges to becoming physically active. Unfortunately, interventions in ambulatory hospital clinics for people with musculoskeletal disorders primarily focus on their presenting musculoskeletal complaint with cursory attention given to lifestyle risk factors; including physical inactivity. This missed opportunity is likely to have both personal costs for patients and economic costs for downstream healthcare funders. Objectives The objective of this study was to investigate the presence of obesity, diabetes, diagnosed cardiac conditions, and previous stroke (CVA) among insufficiently physically active patients accessing (non-surgical) ambulatory hospital clinics for musculoskeletal disorders to indicate whether a targeted risk-reducing intervention is warranted. Methods A sub-group analysis of patients (n=110) who self-reported undertaking insufficient physical activity level to meet national (Australian) minimum recommended guidelines was conducted. Responses to the Active Australia Survey were used to identify insufficiently active patients from a larger cohort study being undertaken across three (non-surgical) ambulatory hospital clinics for musculoskeletal disorders. Outcomes of interest included body mass index, Type-II diabetes, diagnosed cardiac conditions, previous CVA and patients’ current health-related quality of life (Euroqol-5D). Results The mean (standard deviation) age of inactive patients was 56 (14) years. Body mass index values indicated that n=80 (73%) were overweight n=26 (24%), or obese n=45 (49%). In addition to their presenting condition, a substantial number of patients reported comorbid diabetes n=23 (21%), hypertension n=25 (23%) or an existing heart condition n=14 (13%); 4 (3%) had previously experienced a CVA as well as other comorbid conditions. Health-related quality of life was also substantially impacted, with a mean (standard deviation) multi-attribute utility score of 0.51 (0.32). Conclusion A range of health conditions and risk factors for further negative health events, including cardiovascular complications, consistent with physically inactive lifestyles were evident. A targeted risk-reducing intervention is warranted for this high risk clinical group.
Resumo:
Objective To determine the relationship between family child care home (FCCH) practices and characteristics, and objectively measured physical activity (PA) among children attending FCCHs. Methods FCCH practices and characteristics were assessed in 45 FCCHs in Oregon (USA) in 2010-2011 using the Nutrition and Physical Activity Self-Assessment for Child Care Instrument. Within the 45 FCCHs, 136 children between ages 2 and 5. years wore an accelerometer during child care attendance over a one-week period. Time spent in light, moderate, and vigorous PA per hour was calculated using intensity-related cut-points (Pate et al., 2006). Results FCCH characteristics and practices associated with higher levels of PA (min/h; p < 0.05) included provision of sufficient outdoor active play [32.2 (1.0) vs. 28.6 (1.3)], active play using portable play equipment [31.7 (1.0) vs. 29.3 (1.4)], the presence of a variety of fixed play equipment [32.2 (1.0) vs. 28.9 (1.3)], and suitable indoor play space [32.2 (1.0) vs. 28.6 (1.3)], engaging in active play with children [32.1 (1.1) vs. 29.6 (1.2)], and receiving activity-related training [33.1 (1.2) vs. 30.3 (1.1)]. Conclusions This is the first study to identify practices and characteristics of FCCHs that influence children's PA. These data should be considered when developing programs and policies to promote PA in FCCHs.
Resumo:
Background This study evaluated the feasibility and preliminary efficacy of a church-based intervention to promote physical activity (PA) in children. Methods The study was conducted in 4 churches located in 2 large metropolitan areas and 2 regional towns in Kansas. Churches in the intervention condition implemented the "Shining Like Stars" physical activity curriculum module during their regularly scheduled Sunday school classes. Churches in the control condition delivered the same content without integrating physical activity into the lessons. In addition to the curriculum, the intervention churches completed a series of weekly family devotional activities designed to promote parental support for PA and increase PA outside of Sunday school. Results Children completing the Shining Like Stars curriculum exhibited significantly greater amounts of MVPA than those in the control condition (20 steps/min vs. 7 steps/min). No intervention effects were observed for PA levels outside of Sunday school or parental support for PA; however, relative to controls, children in the intervention churches did exhibit a significant reduction in screen time. Conclusion The findings confirm that the integration of physical activity into Sunday school is feasible and a potentially effective strategy for promoting PA in young children.
Resumo:
Basement membranes serve as significant barriers to the passage of tumor cells but ones which metastatic cells can pass. This involves the production of a cascade of proteases leading to the activation of a specific collagenase that degrades the unique collagen network in basement membrane. Breast cancer cells, when estrogen dependent, show a requirement for estrogen for invasive activity. However, when these cells progress to an estrogen independent state and increased malignancy, they express an invasive phenotype constitutively. Studies with various anti-estrogens suggest that these responses are mediated via the estrogen receptor. Anti-estrogens lacking agonist activity suppress invasiveness as well as growth of the breast cancer cells.
Resumo:
Kaposi's sarcoma (KS) is a relatively low grade neoplasm, classically occurring in the skin of elderly men. A more virulent and invasive form of Kaposi's sarcoma has been described in patients with acquired immune deficiency syndrome (AIDS). The origin and identification of the tumor cells in these lesions is controversial. Here we have studied the behavior of cells derived from KS lesions in an in vitro assay which measures the ability of cells to invade through a reconstituted basement membrane. In agreement with previous work, KS cells obtained under selective culture conditions were invasive showing activity comparable to that of malignant tumor cells. Normal fibroblasts, smooth muscle cells, and endothelial cells did not demonstrate invasive behavior under the same experimental conditions. To characterize further the nature of the KS cells we tested the chemotactic response of cells from the most invasive line to a variety of growth factors and compared their response to those of fibroblasts, smooth muscle, and endothelial cells. These studies suggest that normal cells respond to a unique repertoire of chemotactic factors. The chemotactic response of the KS cells most closely resembled that of smooth muscle cells and was quite distinct from endothelial cells. These results indicate that the KS-derived cultures contain invasive cells with a smooth muscle cell-like phenotype.
Resumo:
The current understanding of the regulation of breast cancer cell proliferation and invasiveness by hormones and growth factors is reviewed. It has been shown that polypeptide growth factors are involved in hormone-independent breast cancer, and are sometimes oestrogen-regulated in hormone-responsive models. Basement-membrane invasiveness, relating to the metastatic potential of these cells, is also stimulated by oestrogen in hormone-dependent models, elevated in hormone-independent models, and is growth factor sensitive. Further understanding of the differential effects of growth factors on breast cancer cell proliferation and invasiveness should facilitate better therapeutic exploitation of regulation at this level.
Resumo:
This thesis is an empirical study of the factors impacting on the client involvement in Saudi Arabian construction government projects. The study investigated the impact of some factors that limited the client involvement and developed a framework called "client involvement interactive" to improve the client involvement practices in Saudi Arabian construction projects through the implementation of an implementable strategy elaborated.
Resumo:
Aim To identify key predictors and moderators of mental health ‘help-seeking behavior’ in adolescents. Background Mental illness is highly prevalent in adolescents and young adults; however, individuals in this demographic group are among the least likely to seek help for such illnesses. Very little quantitative research has examined predictors of help-seeking behaviour in this demographic group. Design A cross-sectional design was used. Methods A group of 180 volunteers between the ages of 17–25 completed a survey designed to measure hypothesized predictors and moderators of help-seeking behaviour. Predictors included a range of health beliefs, personality traits and attitudes. Data were collected in August 2010 and were analysed using two standard and three hierarchical multiple regression analyses. Findings The standard multiple regression analyses revealed that extraversion, perceived benefits of seeking help, perceived barriers to seeking help and social support were direct predictors of help-seeking behaviour. Tests of moderated relationships (using hierarchical multiple regression analyses) indicated that perceived benefits were more important than barriers in predicting help-seeking behaviour. In addition, perceived susceptibility did not predict help-seeking behaviour unless individuals were health conscious to begin with or they believed that they would benefit from help. Conclusion A range of personality traits, attitudes and health beliefs can predict help-seeking behaviour for mental health problems in adolescents. The variable ‘Perceived Benefits’ is of particular importance as it is: (1) a strong and robust predictor of help-seeking behaviour, and; (2) a factor that can theoretically be modified based on health promotion programmes.
Resumo:
The peritubular zone of the rat testis has an extensive extracellular matrix (ECM). Fibronectin (FN) is distributed primarily in the basal lamina of the seminiferous tubule boundary tissue and is synthesized by peritubular myoid cells. Several extracellular changes are mediated by growth factors and these changes occur at the time of hormone mediated testicular development, particularly in the peritubular zone. The effects of serum or dibutyryl cyclic AMP (cAMP) on FN production by the mesenchymal peritubular myoid cells were evaluated. Rats of various ages (10, 15, 20, 40 and 80 days) were employed for immunofluorescent localization of rat testicular FN in frozen sections. In all age groups tested, FN was primarily present in a broad layer around each seminiferous tubule, and blood vessel, and in variable distribution throughout the interstitial stroma. By day 20 there was no clear distinction in FN staining between the peritubular zone and the interstitial tissue. This indicates an involvement of FN in the ECM developments which occur in the peritubular zone of the testis at this time. The peritubular myoid cells were isolated from 20-22 day old rat testis and cultured on glass coverslips. These cells were grown to confluence with 10% fetal calf serum (FCS) in medium until day 4 and then subcultured to have secondary monocultures maintained with or without serum. By means of immunofluorescence and cytochemistry using avidin-biotin peroxidase complex it was observed that peritubular myoid cells were positive for FN and most of the FN was localized in the perinuclear region. Subcultured peritubular myoid cells maintained for 4 days in medium containing FCS developed an extensive interconnecting FN matrix. In the presence of 0.5 mM cAMP in culture, FN became localized along the filamentous process of peritubular myoid cells and more prominently in the areas of triangulated multi-cell aggregates as well as on the surface of the contracted small spherical cells. The addition of cAMP in the presence of FCS, also caused a noticeable change in the staining pattern; FN was detected along the filamentous process developing into a complex network of cells encased in an extensive matrix. It would appear that the translocation of FN in the cytoplasmic extensions of peritubular myoid cells may be a direct consequence of morphological changes associated with metabolic regulation of cAMP. This may also be related to the puberty associated development of in vivo changes in the ECM produced by peritubular myoid cells.
Resumo:
Objective: An increasing body of evidence is emerging linking adipogenesis and inflammation. Obesity, alone or as a part of the metabolic syndrome, is characterized by a state of chronic low-level inflammation as revealed by raised plasma levels of inflammatory cytokines and acute-phase proteins. If inflammation can, in turn, increase adipose tissue growth, this may be the basis for a positive feedback loop in obesity. We have developed a tissue engineering model for growing adipose tissue in the mouse that allows quantification of increases in adipogenesis. In this study, we evaluated the adipogenic potential of the inflammogens monocyte chemoattractant protein (MCP)-I and zymosan-A (Zy) in a murine tissue engineering model. Research Methods and Procedures: MCP-I and Zy were added to chambers filled with Matrigel and fibroblastgrowth factor 2. To analyze the role of inducible nitric oxide synthase (iNOS), the iNOS inhibitor aminoguanidine was added to the chamber. Results: Our results show that MCP-I generated proportionally large quantities of new adipose tissue. This neoadipogenesis was accompanied by an ingrowth of macrophages and could be mimicked by Zy. Aminoguanidine significantly inhibited the formation of adipose tissue. Discussion: Our findings demonstrate that low-grade inflammation and iNOS expression are important factors in adipogenesis, Because fat neoformation in obesity and the metabolic syndrome is believed to be mediated by macrophage-derived proinflammatory cytokines, this adipose tissue engineering system provides a model that could potentially be used to further unravel the pathogenesis of these two metabolic disorders.
Resumo:
This thesis used a cross-sectional survey to examine how Vietnamese nurses educate COPD patients about the self-management of their disease. Further, the study also describes the characteristics of Vietnamese nurses working in COPD specialty areas as well as examining their COPD knowledge and the factors which influence their delivery of COPD self-management education when caring for COPD patients. The study found that while Vietnamese nurses are likely to deliver self-management education to the COPD patients they care for, there are areas for improvement in nurses' knowledge in all areas of COPD management and self management education.