Cardiovascular diseases (CVD) are the leading cause of death worldwide and the atherosclerotic process that precedes CVD starts during childhood. Physical activity (PA), cardiorespiratory fitness (CRF) and exercise are well known as preventive strategies for CVD. One possible mechanism for such prevention is the role of PA, CRF and exercise on the arterial and autonomic systems. The aim of this thesis was to investigate using observational and experimental studies the role of PA, CRF and exercise on the autonomic and arterial systems of healthy adolescents. Chapter 4 systematically reviewed observational cross-sectional studies and provided level one evidence for a significant and positive association between resting parasympathetic function and moderate-to-vigorous PA in youth. Chapter 4 also indicated that gaps exist in the literature such as the associations between PA intensities, CRF and heart rate variability (HRV). These findings were furthered in Chapter 5 which showed that vigorous PA (VPA) and moderate PA (MPA) were positively related with HRV at rest and cardiac autonomic recovery following exercise in adolescents. In Chapter 6 a high-fat meal was used aiming to increase CVD risk in the postprandial state, and it was demonstrated that PA levels and CRF are not significantly associated with postprandial HRV and arterial stiffness in adolescents. Aiming to investigate possible associations between the vascular and autonomic system, measures of baroreflex sensitivity (BRS) were introduced. Chapter 7 showed that BRS and its autonomic and vascular components present a between-day coefficient of variation lower than 20% whilst within day coefficient of variations were lower than 34% in adolescents. In Chapter 8 acutely following high- and moderate-intensity interval exercise a decrease in blood pressure was observed concomitantly with decreases in BRS. This was mainly mediated by decreases in the autonomic modulation, and the duration of the decreases in blood pressure was higher following high-intensity interval exercise. Chapter 9 extended these findings by demonstrating that the changes in BRS following the ingestion of glucose was not altered by the high or moderate-intensity exercise performed before glucose ingestion. Chapter 10 showed that following four weeks of high-intensity exercise interval training no improvements were observed in BRS and its autonomic and vascular components at rest or acutely following exercise. Collectively, the present thesis contributes significantly to the literature by providing novel evidence in healthy adolescents on the role of PA intensities, CRF and exercise on the arterial and autonomic systems at rest, acutely following exercise and in the postprandial state. The results gathered in this thesis indicate potential of the autonomic and vascular function as targets of CVD risk reduction in youth.

Introduction Non-union (NU) is a fracture that will not unite. With over one million fractures per annum in the UK long bone non-union has serious social and economical implications. There is little epidemiological data available specifically looking at this NU patient cohort. Studies that are bone specific quote rates of non-union as a proportion of their study group but there is no data quantifying the incidence of NU in the population or per fracture. Studies have highlighted risk factors associated with atrophic non-union including age, diabetes, non-steroidals, and cigarette smoking. There is scientific interest regarding how best to classify non-unions and the role of biological agents in treating them. Aims • To quantify the incidence of non-union in a large population and calculate the risk of non-union per fracture according to age, sex and anatomical distribution. • To assess the causes contributing to non-union and outcomes of treatment in a non-union cohort and validate a new non-union scoring system. • To test the treatment potential of a novel molecule (monobutyrin) and a growth factor in a small animal model of non-union. Method • Using the ICD-10 data from the Scottish population as collected by NHS Scotland the incidence of non-union and fractures were calculated. • A cohort of 100 non-union patients were studied for risk factors associated with their non-union, treatment outcome and to assess a new NU classification system. • A rat model of tibial non-union was used to assess the potential of monobutyrin and BMP-2 in treating non-union in an animal model. Results • Fracture non-union is very rarely found in children (1 in 500 fractures) and occurs in up to 1 in 50 adult fractures. Non-union of a fracture has a significantly higher risk in young adults than the elderly by about 3 fold. Osteoporosis may not be a risk for non-union. The tibia and clavicle are the sites with the greatest potential for fracture non-union. • Non-union is multifactorial in two out of three patients. Biomechanical stability, patient host factors and infection must all be considered in every patient. Occult or unexpected recurrent infection is present in up to 10% of patients. When all factors are considered in treatment the outcome is 95% successful with 88% requiring 2 or less procedures to heal the non-union and only a minority requiring adjuvant graft or biological agents. The proposed new classification system is complex and did not clearly identify those patients who would require adjuvant treatment (eg bone grafting or BMP) or those likely to have unsuccessful non-union treatment. • Monobutyrin and BMP-2 when tested on the small animal non-union model did not improve the success rate of union. Conclusions Non-union affects approximately 1000 people per year in Scotland, this figure is not as high as 5-10% of all fractures. It is associated with fractures in young adults and of the clavicle and tibia, treatment can have a very high success rate without the need for adjuvant biological polytherapy when all contributing factors are considered and managed appropriately. A new non-union classification needs to incorporate the multifactorial aspects of non-union without being too complex to use in everyday clinical situations.

nÃo hà / As mortes desencadeadas em crianÃas menores de um ano de vida sÃo influenciadas por fatores biolÃgicos, culturais, demogrÃficos, socioeconÃmicos e assistenciais. Este trabalho teve como objetivo avaliar a evitabilidade dos Ãbitos infantis ocorridos na Secretaria Executiva Regional VI em Fortaleza-CE, em 2008 e 2009. Trata-se de um estudo do tipo ecolÃgico, descritivo e quantitativo, tendo como desfecho a ocorrÃncia do Ãbito infantil. Foram estudados 192 Ãbitos, de uma populaÃÃo de 240. As variÃveis foram agrupadas de acordo com as caracterÃsticas sociodemogrÃficas e maternas. Analisaram-se as mÃdias, medianas e IC95% de variÃveis quantitativas. Para avaliaÃÃo da evitabilidade dos Ãbitos, foram usados os critÃrios propostos pela Lista Brasileira de Mortes EvitÃveis no Sistema Ãnico de SaÃde, apÃs anÃlise pelo Comità Regional de PrevenÃÃo do Ãbito Infantil e Fetal. Em 2008,54% e 2009,52% dos Ãbitos em menores de um ano foram considerados evitÃveis pelo ComitÃ. Comprovou-se que 30% dos Ãbitos de menores de um ano ocorridos em 2008 sÃo reduzÃveis por aÃÃes adequadas de diagnÃstico e tratamento; 26% por adequada atenÃÃo à mulher na gestaÃÃo; 22% por aÃÃes adequadas de promoÃÃo à saÃde; 12% reduzÃveis por adequada atenÃÃo ao recÃm-nascido; 8% por adequada atenÃÃo à mulher no parto, e 2% reduzÃveis por aÃÃes de imunoprevenÃÃo. Dos Ãbitos evitÃveis em 2009, 44% foram classificados como reduzÃveis por adequada atenÃÃo à mulher na gestaÃÃo; 33% por aÃÃes adequadas de diagnÃstico e tratamento; 10% por adequada atenÃÃo ao recÃm-nascido; 7% por aÃÃes adequadas de promoÃÃo à saÃde; e 6% reduzÃveis por adequada atenÃÃo à mulher no parto. Os resultados encontrados podem ser utilizados para o direcionamento de intervenÃÃes efetivas que visem a diminuir a mortalidade infantil, tanto no Ãmbito da Secretaria Executiva Regional VI, como nas demais secretarias do municÃpio de Fortaleza. / Deaths triggered in children less than one year of life are influenced by biological, cultural, demographic, socio-economic and assistance factors. This study describes the epidemiology profile of infant deaths that happened in the 6th Regional Executive Office in Fortaleza-CE, Brazil, in 2008 and 2009 and assesses its avoidability according to the results of the Regional Committee for the Prevention of Infant and Fetal Death (CRPOIF). This is an ecological, descriptive and quantitative study, with the outcome of the occurrence of infant death. 192 deaths were studied in a population of 240. Variables were grouped according to maternal socio-demographic characteristics. For data processing we used the Epi-Info software version 3.5.1, with analysis of means, medians of some variables and adopted the Confidence Interval of 95%. To assess the avoidability of deaths, we used the criteria proposed by the Brazilian List of Preventable Deaths in the National Health System after being reviewed by the committee. In 2008 (54%) and 2009 (52%) of deaths in children under one year of life were considered preventable by the CRPOIF based on this list, and following the classification adopted to analyze the deaths. It was concluded that 30% of deaths of children under one year old in 2008 are avoidable by appropriate actions of diagnosis and treatment, 26% by appropriate care to women in pregnancy, 22% by appropriate actions for health promotion, 12% are avoidable by appropriate care to newborns, 8% by appropriate care to women during childbirth, and 2% reduced through actions of vaccine prevention. From the avoidable deaths in 2009, 44% were reduced through appropriate care to women in pregnancy, 33% by appropriate actions for diagnosis and treatment, 10% by appropriate care to newborns, 7% by appropriate actions to health promotion and 6% reduced through appropriate care to women in childbirth. These results can be used to address effective interventions that aim to reduce infant mortality, both within the 6th Regional Executive Office, as in the other offices of this city.

Scientific interest in the clinical implications, public health importance, and risk factors of anxiety disorders has grown substantially in the past two decades. Despite this, the evidence base on anxiety is insufficient to inform health care planning and policy-making. Further research on the outcomes and risk factors associated with anxiety disorders, and ways of mitigating these risks is needed. One of the aims of this thesis was to provide an overview of the existing literature on the prevalence of anxiety in adults living in countries across the globe, and to describe the prevalence in the context of various health states and life stages. Because generalised anxiety disorder is one of the most common psychiatric conditions in the population, the remainder of the thesis focused on this disorder and aimed to explore its links with health service use and mortality. Risk for this condition was also explored and area deprivation was studied as a possible determinant. Since depression is commonly studied alongside anxiety, the relationship between the residential environment and major depressive disorder was also assessed. Finally, to provide insight into the mitigation of risks of generalised anxiety disorder, a study of coping mechanisms was undertaken. Primary study findings from this thesis are based on the European Prospective Investigation of Cancer in Norfolk, a large, population study of British people over the age of 40. Results from the systematic review showed that anxiety is common in population sub-groups around the world, with women, younger people, and those suffering from chronic physical conditions, such as cancer and cardiovascular disease being particularly affected. Results from the primary studies of the thesis showed that generalised anxiety disorder is associated with increased risk for deaths, though it is not significantly associated with non-psychiatric hospital admissions. Results from the risk factor analyses showed that living in a deprived area is associated with generalised anxiety disorder in women and major depressive disorder in men. The risk mitigation analysis indicated that sense of coherence is an important coping mechanism that can protect against generalised anxiety disorder among women living in disadvantaged circumstances. My work has shown novel associations and attempted to provide a more complete picture of one of the most common psychiatric conditions in the population by focusing on several angles: health outcomes, risk factors, and ways of mitigating risks.

It is well established that such student precollege cognitive measures as high school GPA and test scores (ACT, SAT) have a certain predictive value in student retention. While research is replete with evidence of the value of student advising in a college’s retention strategy, there is a gap in the literature on the impact of using noncognitive survey information by advisors to better target student deficiencies. The primary goal of this study was to explore the relationship between retention and exposure to noncognitive risk factor information for students and advisors. One thousand fifty-four freshmen students enrolled in a first-year experience (FYE) course at Dixie State College were given the Student Strengths Inventory (SSI) survey that measures six different noncognitive risk factor variables. By using a regression discontinuity design, students were initially divided into two sample groups using an index score generated by combining the high school GPA and ACT (or equivalent) test score. Students who fell below the cutoff point were further subdivided by random sampling into three groups: (a) students who received their survey results with no further action, (b) students selected for general advisement, and (c) students selected for targeted advisement using the survey results. When comparing the retention rates from fall semester 2009 to fall semester 2010, the retention rates varied as predicted by the researcher; however, these differences in retention could not be attributed to the usage of the survey with one exception: when the treatment group was filtered only to include first-generation students, usage of the survey results was statistically significant in contributing to a 62% retention rate, the highest of any of the sample groups studied.

No description available.

Adolescent growth provides a unique opportunity for the growing body to adapt to external stimuli. A positive association between site-specific mechanical loading and increases in regional bone mineral content (BMC) during adolescence is established. Mechanical loads associated with middle-distance running expose the skeleton to a combination of compressive ground reaction forces and muscular contraction. Previous studies concerning musculoskeletal health in active adolescents are largely limited to planar, two-dimensional measures of bone mineral status, using Dual X-ray Absorptiometry (DXA). Intrinsic bone material properties are accurately measured using DXA. However, the interaction between bone material and structural properties that reflects the mechanical integrity of bone require a combination of imaging modalities. Magnetic Resonance Imaging (MRI) provides a three-dimensional geometric and biomechanical assessment of bone. When MRI is integrated with DXA technology, an effective non-invasive method of assessing in vivo bone strength is achieved. The impact of high training volumes on musculoskeletal development of male and female adolescent athletes engaged in repetitive, high magnitude mechanical loading has not been investigated. Specifically, differences in total body and regional bone mineral, bone and muscle geometry, bone biomechanical indices and bone strength at differentially-loaded skeletal sites have not been compared between adolescent middle-distance runners and age- and gender-matched non-athletic controls. Objectives: (i) to investigate the effects of intense sports participation involving mechanical loading patterns on bone mineral, bone and muscle geometry, biomechanical indices and estimated regional bone strength between elite adolescent male and female middle-distance runners and age- and gender-matched controls (ii) to examine factors predictive of total body BMC, distal tibial bone geometry, distal tibial bone strength, and Hip Strength Analysis (HSA)- derived indicators of bone strength at the femoral neck. Methods: Four groups of 20 adolescents were comprised of male (mean (SD) age 16.8 ± 0.6 yr, physical activity 14.1 ± 5.7 hr.wk-1) and female (age 16 ± 1.7 yr, physical activity 8.9 ± 2.1 hr.wk-1) middle-distance runners, and male (16.4 ± 0.7 yr, physical activity 2.2 ± 0.7 hr.wk-1) and female (age 16 ± 1.8 yr, physical activity 2.0 ± 0.07 hr.wk-1) controls. Total body and regional BMC were calculated using DXA. Distal tibial bone and muscle cross-sectional areas (CSA) were assessed using MRI. To calculate distal tibial bone strength index (BSI), a region of interest representing 10% of the mid distal tibia was analysed for DXA-derived bone mineral and was combined with bone geometry and biomechanical properties from MRI assessments. Calculations for femoral neck strength were acquired from DXA-derived HSA software. Results: No differences were found between male athletes and controls for unadjusted BMC at total body or regional sites. After covarying for fat mass (kg), male athletes displayed greater BMC at the lumbar spine (p = 0.001), dominant proximal femur (p = 0.001) and dominant leg (p = 0.03) than male controls. No differences were found in distal tibial bone geometry, bone strength at the distal tibia or HSA-derived indicators of bone strength at the femoral neck between male athletes and controls. Lean tissue mass and fat mass were the strongest predictors of total body BMC (R2 = 0.71), total muscle CSA explained 43.5% of variance in BSI at the distal tibia, and femur length and neck of femur CSA explained 33.4% of variance at the femoral neck. In females, athletes displayed greater unadjusted BMC at the proximal femur (+3.9 ±1.4 g, p = 0.01), dominant femoral neck (+0.5 ± 0.12 g, p = 0.01) and dominant tibia (+4.1 ± 2.1 g, p = 0.05) than female controls. After covarying for fat mass (kg), female athletes displayed greater (p = 0.001) total body, dominant proximal femur and dominant leg BMC than female controls. Female athletes also showed greater distal tibial cortical CSA (+30.9 ± 9.5 mm2, p = 0.003), total muscle (+240.2 ± 86.4 mm2, p = 0.03) and extensor muscle (+46.9 ±19.5 mm2, p = 0.02) CSA, smaller medullary cavity (-32.3 ± 14.7 mm2, p = 0.03) CSA and greater BSI at the distal tibia (+28037 ± 8214.7 g/cm3.mm4, p = 0.002) than female controls. Lean tissue mass and fat mass were the strongest predictors of total body BMC (R2 = 65), hours of physical weekly activity and total muscle CSA explained 58.3% of the variance of distal tibial BSI, and neck of femur CSA accounted for 64.6% of the variance in a marker of femoral neck HSA. Conclusion: High training loads are associated with positive musculoskeletal outcomes in adolescent middle-distance runners compared to non-athletic controls. Exposure to similar high training loads may advantage female adolescent athletes, more than male adolescent athletes compared with less active peers in bone strength at the distal tibia.

<p> </p><p><strong></strong>The aim of this quantitative study was to identify risk factors that could cause or produce criminal behaviour among offenders under the age of 18 in East London, South Africa. This research looks into risk factors such as individual- home environment and neighbourhood factors. A non-probability sample of 80 young people within the age range of 12-18 answered a standardized self-administered questionnaire while attending a compulsory pre-trial assessment with probation officers at the Magistrate’s court in East London. The individual factors behind delinquency were evidently gender based, a majority was males and between 16-18 years. Other risk factors were related to family structure or family functioning and the living standard of the household. The participants own explanations for committing the crime were connected to individual factors such as: influenced by friends, influenced by alcohol, bored and had nothing to do.</p><p> </p>

TB recurrence is defined as a new episode of bacteriologically positive TB in a patient previously declared successfully completed treatment. Our study objective was to identify risk factors of recurrence among HIV-infected and HIV-uninfected TB patients. Based on a population-based TB/HIV surveillance database of Chiang Rai Province, Thailand, a retrospective cohort of TB patients with successful completions of treatment between 1997 and 2008 was constructed. Poisson regression was used to model independent effects of risk factors. TB recurrence rates were 5.4/1,000 PYs and 9.7/1,000 PYs for HIV-uninfected and infected TB patients, respectively. We identified that among HIV-uninfected patients, older age, being hilltribe, being prisoners, were at higher risk of recurrence. While among HIV-infected patients, younger age, being male, and having been cured from initial episode were associated with higher recurrence rates. Targeted, practical preventive and treatment strategies for those patients need to be implemented to lower the TB recurrence rates. / Epidemiology

The purpose of this thesis was to develop a means of predicting future injury among nursing personnel working in a hospital system. Nursing has one of the highest incidence rates of musculoskeletal injuries among U.S. occupations. Endemic to the job are tasks such as rolling, sitting, standing, and transferring large, and often times, uncooperative patients. These tasks often place large biomechanical stresses on the musculoskeletal system and, in some cases, contribute to or cause a musculoskeletal injury. Given the current nursing shortage, it is imperative to keep nurses injury-free and productive so they can provide patient care services. Even though a large number of nursing personnel are injured every year and most are exposed to these high levels of biomechanical stress, the majority of nurses are injury-free. The question then arises "Why do some nurses have injuries while others do not?" The purpose of this thesis was to determine whether individual attributes in a population of nurses were associated with risk of future injury. The subject population was comprised of 140 nursing personnel at a local hospital system hired between April 1995 and February 1999. Data on individual attributes, such as patient demographics, previous injuries, posture, joint range of motion, flexibility, and muscular strength, was ascertained during a post-offer screening on these personnel. Twenty six (19%) nurses experienced an injury associated with the axial skeleton. Chi square test for homogeneity for the categorical predictor variables, and the Student's T-test for continuous predictor variables were used to determine if any individual attributes were associated with future injuries. None of the variables were associated with a risk of future axial skeletal injury. Practical application of these results for St. Joseph Regional Health Center, and possibly other acute care facilities, directs us to stop costly pre-employment/post-offer testing for the purpose of identifying injury prone nurse applicants. Secondly, it allows the focus of limited resources to be on making the job safer through administrative and engineering controls.