981 resultados para factors for failure
Resumo:
On March 11 2011, an exceptionally large tsunami event was triggered by a massive earthquake offshore, the northeast coast of Japan, which affected coastal infrastructure such as seawalls, coastal dikes and breakwaters in the Tohoku region. Such infrastructure was built to protect against the Level 1 tsunamis that previously hit the region, but not for events as significant as the 2011 Tohoku tsunami, which was categorized as a Level 2 tsunami [Shibayama et al. 2013]. The failure mechanisms of concrete-armoured dikes, breakwaters and seawalls due to Level 2 tsunamis are still not fully understood by researchers and engineers. This paper investigates the failure modes and mechanisms of damaged coastal structures in Miyagi and Fukushima Prefectures, following the authors' post-disaster field surveys carried out between 2011 and 2013. Six significant failure mechanisms were identified for the coastal dikes and seawalls affected by this tsunami: 1) Leeward toe scour failure, 2) Crown armour failure, 3) Leeward slope armour failure, 4) Seaward toe and armour failure, 5) Overturning failure, and 6) Parapet wall failure, in which leeward toe scour being recognized as the major failure mechanism in most surveyed locations. The authors also propose a simple practical mathematical model for predicting the scour depth at the leeward toe of the coastal dikes, by considering the effects of the tsunami hydrodynamics, the soil properties and the type of structure. The key advantage of this model is that it depends entirely on quantities that are measurable in the field. Furthermore this model was further refined by conducting a series of hydraulic model experiments aimed to understand the governing factors of the leeward toe scour failure. Finally, based on the results obtained, key recommendations are given for the design of resilient coastal defence structures that can survive a level 2 tsunami event.
Resumo:
Heart failure (HF) is a major health concern affecting 15 million people in Europe and around 900 000 people in the U.K. HF predominantly affects the elderly, with the mean age of patients with a diagnosis of HF between 70 and 80 years. Most previous HF studies have accordingly focused on older patients. Although HF is less common in younger adults (<65 years), 15% to 20% of patients hospitalised with HF are younger than 60 years of age. Very few studies have described the characteristics of younger adults with HF and its outcome. The aims of this thesis are to describe the clinical characteristics of younger adults with HF, explore the epidemiology of HF in younger adults and determine their short- and long-term outcomes. This was made possible by access multiple databases consisting of large patient cohorts with HF. The first chapter is a systematic literature review of younger adults with HF. Gaps in the current literature were identified and the thesis focused on some of these. The CHARM study allows detail characterisations of younger adults with HF. It recorded characteristics of patients with HF, including symptoms and signs of HF, electrocardiographic changes, chest radiographic findings, and also left ventricular ejection fraction. HF hospitalisations and its precipitating factors were also recorded systematically. Younger adults were more likely to have a third heart sound and hepatomegaly, but less likely to have pulmonary crackles and peripheral oedema. Similarly, radiological findings in younger adults were less likely to show interstitial pulmonary oedema or pleural effusion. Interestingly, younger adults aged <40 years not only have similar HF hospitalisation rate to older patients, however during their presentation with decompensated HF, they were less likely to have clinical pulmonary oedema and radiological signs of HF. Physicians managing younger adults with HF need to be aware of this. Younger adults were also less compliant with medications and lifestyle restriction resulting in hospitalisation with decompensated HF. Fortunately, despite these challenges, mortality rates in younger adults with HF were lower compared to older patients. To further substantiate the findings from the CHARM study, the MAGGIC study, a meta-analysis consists of over 40 000 patients with HF from large observational studies and randomised controlled trials, was examined. In both databases, the commonest aetiology of HF in younger adults was dilated cardiomyopathy. The ejection fraction was the lowest in younger adults. Similar to the CHARM study, mortality rates in younger adults were lower compared to older patients. However, in the MAGGIC study, by stratifying mortality into patients with preserved ejection fraction and with reduced ejection fraction, younger patients with preserved ejection fraction have a much lower mortality rate compared to patients with reduced ejection fraction. Findings from clinical trials are not always reflective of the real life clinical practice. The U.K. Clinical Practice Research Datalink (CPRD), a large and well-validated primary care database with 654 practices contributing information into the database representing approximated 8% of the U.K. population, is a rich dataset offering a unique opportunity to examine the characteristics, treatments, and outcomes of younger adults with HF in the community. In contrast to the CHARM and MAGGIC studies, younger adults aged <40 years were stratified into 20-29 and 30-39 years in the CPRD analysis. This is possible due to the larger number of younger adults with HF. Further stratifying the younger age groups demonstrated heterogeneity among younger adults with HF. In contrast to previous data showing younger adults have lower co-morbidities, the proportions of depression, chronic kidney disease, asthma, and any connective tissue disease were high among patients aged 20-29 years in the analysis from the CPRD. Surprisingly, the treatment rates for angiotensin converting enzyme (ACE) inhibitor, and aldosterone antagonist were the lowest in patients aged 20-29 years. With the exception of patients aged ≥80 years, treatment rate with beta-blocker was also the lowest in patients aged 20-29 years. With over two decades of follow up, long-term mortality rates in younger adults with HF can be determined. The mortality rates continued to decline from 1988 to 2011. Physicians managing younger adults with HF can now use this contemporary data to provide prognostic information to patients and their family. A hospital administrative database is the logical next platform to explore younger adults with HF. The Alberta Ministry of Health database links an outpatient database to a hospitalisation database providing ample data to examine the relationship between outpatient clinic visits and hospital admissions in younger adults with HF. Following a diagnosis of HF in the outpatient setting, younger adults were admitted to the hospital with decompensated HF much sooner than older patients. Younger adults also presented to emergency department more frequently following their first hospitalisation for HF. In conclusion, this thesis presented the characteristics and outcomes of younger adults with HF, and helped to extend our current understanding on this important topic. I hope the data presented here will benefit not only physicians looking after younger adults with HF, but also patients and their family.
Resumo:
Objetivo: Verificar a prevalência e os fatores associados ao sobrepeso e à obesidade entre adolescentes de uma escola pública em Campinas, São Paulo. Métodos: Estudo observacional, transversal, realizado entre julho e setembro de 2013, com 107 jovens entre 15 e 19 anos que cursavam o ensino médio em uma escola pública do município de Campinas, São Paulo. Utilizou-se um questionário para investigar dados sociodemográficos e fatores de risco para sobrepeso e obesidade. Além disso, verificaram-se dados clínicos (peso, altura, pressão arterial). Resultados: A amostra se caracterizou com predomínio de mulheres (n=65, 60,7%) com 16,5 anos em média e renda familiar entre 2 e 4 salários mínimos (n=53, 49,5%). A prevalência de sobrepeso e obesidade foi de 18 (16,8%) e 9 (8,4%), respectivamente. Destaca-se que 62 (58%) sempre omitiam uma refeição, 54 (50,5%) sempre se alimentavam vendo televisão e 56 (52,3%) não praticavam atividade física fora da escola. Tentar e não conseguir fazer dieta foi associado ao sobrepeso e à obesidade, e autoimagem curvilínea foi associada à obesidade. Conclusão: O estudo revelou que parte significativa da amostra estava com sobrepeso ou obesidade. A falha em manter uma dieta e a autoimagem curvilínea associadas às alterações nutricionais sugerem que os adolescentes tinham consciência dessas alterações e se preocupavam com o próprio peso, a ponto de buscarem a dieta para tentar emagrecer.
Resumo:
Several companies are trying to improve their operation efficiency by implementing an enterprise resource planning (ERP) system that makes it possible to control the resources of the company in real time. However, the success of the implementation project is not a foregone conclusion; a significant part of these projects end in a failure, one way or another. Therefore it is important to investigate ERP system implementation more closely in order to increase understanding about factors influencing ERP system success and to improve the probability of a successful ERP implementation project. Consequently, this study was initiated because a manufacturing case company wanted to review the success of their ERP implementation project. To be exact, the case company hoped to gain both information about the success of the project and insight for future implementation improvement. This study investigated ERP success specifically by examining factors that influence ERP key-user satisfaction. User satisfaction is one of the most commonly applied indicators of information system success. The research data was mainly collected by conducting theme interviews. The subjects of the interviews were six key-users of the newly implemented ERP system. The interviewees were closely involved in the implementation project. Furthermore, they act as representative users that utilize the new system in everyday business processes. The collected data was analyzed by thematizing. Both data collection and analysis were guided by a theoretical frame of reference. This frame was based on previous research on the subject. The results of the study aligned with the theoretical framework to large extent. The four principal factors influencing key-user satisfaction were change management, contractor service, key-user’s system knowledge and characteristics of the ERP product itself. One of the most significant contributions of the research is that it confirmed the existence of a connection between change management and ERP key-user satisfaction. Furthermore, it discovered two new sub-factors influencing contractor service related key-user satisfaction. In addition, the research findings indicated that in order to improve the current level of key-user satisfaction, the case company should pay special attention to system functionality improvement and enhancement of the key-users’ knowledge. During similar implementation projects in the future, it would be important to assure the success of change management and contractor service related processes.
Resumo:
My thesis aim is to find out what factors that can explain the entrepreneurial failure in my own entrepreneurial venture to sell Finnish xylitol product to Poland. In addition I seek to answer to the question of why Finnish xylitol products are not sold in Poland. This area has not been studied prior to my thesis. The study method is case study. Data collection is based on auto-ethnographic method where field notes and documents generated from my business venture were used. I discovered that Polish consumers are not exposed to consumer education of xylitol health benefits. The underlying potential in xylitol products expansion from Finland to foreign countries is still mostly unleveraged. My business venture failed because I was not able to convince Finnish confectionery companies Fazer and Cloetta to give enough support for my project. Polish dentists were also opposed having a competitor from Finland to Wrighley company which dominates the Polish confectionery markets.
Resumo:
This article examines regulatory governance of the post-initial training market in The Netherlands. From an historical perspective on policy formation processes, it examines market formation in terms of social, economic, and cultural factors in the development of provision and demand for post-initial training; the roles of stakeholders in the longterm construction of regulatory governance of the market; regulation of and public providers; policy responses to market failure; and tripartite division of responsibilities between the state, social partners, commercial and publicly-funded providers. Historical description and analysis examine policy narratives of key stakeholders with reference to: a) influence of societal stakeholders on regulatory decision-making; b) state regulation of the post-initial training market; c) public intervention regulating the market to prevent market failure; d) market deregulation, competition, employability and individual responsibility; and, e) regulatory governance to prevent ‘allocative failure’ by the market in non-delivery of post-initial training to specific target groups, particularly the low-qualified. Dominant policy narratives have resulted in limited state regulation of the supply-side, a tripartite system of regulatory governance by the state, social partners and commercial providers as regulatory actors. Current policy discourses address interventions on the demand-side to redistribute structures of opportunity throughout the life courses of individuals. Further empirical research from a comparative historical perspective is required to deepen contemporary understandings of regulatory governance of markets and the commodification of adult learning in knowledge societies and information economies. (DIPF/Orig.)
Resumo:
Additive manufacturing, including fused deposition modeling (FDM), is transforming the built world and engineering education. Deep understanding of parts created through FDM technology has lagged behind its adoption in home, work, and academic environments. Properties of parts created from bulk materials through traditional manufacturing are understood well enough to accurately predict their behavior through analytical models. Unfortunately, Additive Manufacturing (AM) process parameters create anisotropy on a scale that fundamentally affects the part properties. Understanding AM process parameters (implemented by program algorithms called slicers) is necessary to predict part behavior. Investigating algorithms controlling print parameters (slicers) revealed stark differences between the generation of part layers. In this work, tensile testing experiments, including a full factorial design, determined that three key factors, width, thickness, infill density, and their interactions, significantly affect the tensile properties of 3D printed test samples.
Resumo:
The clinical syndrome of heart failure is one of the leading causes of hospitalisation and mortality in older adults. Due to ageing of the general population and improved survival from cardiac disease the prevalence of heart failure is rising. Despite the fact that the majority of patients with heart failure are aged over 65 years old, many with multiple co-morbidities, the association between cognitive impairment and heart failure has received relatively little research interest compared to other aspects of cardiac disease. The presence of concomitant cognitive impairment has implications for the management of patients with heart failure in the community. There are many evidence based pharmacological therapies used in heart failure management which obviously rely on patient education regarding compliance. Also central to the treatment of heart failure is patient self-monitoring for signs indicative of clinical deterioration which may prompt them to seek medical assistance or initiate a therapeutic intervention e.g. taking additional diuretic. Adherence and self-management may be jeopardised by cognitive impairment. Formal diagnosis of cognitive impairment requires evidence of abnormalities on neuropsychological testing (typically a result ≥1.5 standard deviation below the age-standardised mean) in at least one cognitive domain. Cognitive impairment is associated with an increased risk of dementia and people with mild cognitive impairment develop dementia at a rate of 10-15% per year, compared with a rate of 1-2% per year in healthy controls.1 Cognitive impairment has been reported in a variety of cardiovascular disorders. It is well documented among patients with hypertension, atrial fibrillation and coronary artery disease, especially after coronary artery bypass grafting. This background is relevant to the study of patients with heart failure as many, if not most, have a history of one or more of these co-morbidities. A systematic review of the literature to date has shown a wide variation in the reported prevalence of cognitive impairment in heart failure. This range in variation probably reflects small study sample sizes, differences in the heart failure populations studied (inpatients versus outpatients), neuropsychological tests employed and threshold values used to define cognitive impairment. The main aim of this study was to identify the prevalence of cognitive impairment in a representative sample of heart failure patients and to examine whether this association was due to heart failure per se rather than the common cardiovascular co-morbidities that often accompany it such as atherosclerosis and atrial fibrillation. Of the 817 potential participants screened, 344 were included in this study. The study cohort included 196 patients with HF, 61 patients with ischaemic heart disease and no HF and 87 healthy control participants. The HF cohort consisted of 70 patients with HF and coronary artery disease in sinus rhythm, 51 patients with no coronary artery disease in sinus rhythm and 75 patients with HF and atrial fibrillation. All patients with HF had evidence of HF-REF with a LVEF <45% on transthoracic echocardiography. The majority of the cohort was male and elderly. HF patients with AF were more likely to have multiple co-morbidities. Patients recruited from cardiac rehabilitation clinics had proven coronary artery disease, no clinical HF and a LVEF >55%. The ischaemic heart disease group were relatively well matched to healthy controls who had no previous diagnosis of any chronic illness, prescribed no regular medication and also had a LVEF >55%. All participants underwent the same baseline investigations and there were no obvious differences in baseline demographics between each of the cohorts. All 344 participants attended for 2 study visits. Baseline investigations including physiological measurements, electrocardiography, echocardiography and laboratory testing were all completed at the initial screening visit. Participants were then invited to attend their second study visit within 10 days of the screening visit. 342 participants completed all neuropsychological assessments (2 participants failed to complete 1 questionnaire). A full comprehensive battery of neuropsychological assessment tools were administered in the 90 minute study visit. These included three global cognitive screening assessment tools (mini mental state examination, Montreal cognitive assessment tool and the repeatable battery for the assessment of neuropsychological status) and additional measures of executive function (an area we believe has been understudied to date). In total there were 9 cognitive tests performed. These were generally well tolerated. Data were also collected using quality of life questionnaires and health status measures. In addition to this, carers of the study participant were asked to complete a measure of caregiver strain and an informant questionnaire on cognitive decline. The prevalence of cognitive impairment varied significantly depending on the neuropsychological assessment tool used and cut-off value used to define cognitive impairment. Despite this, all assessment tools showed the same pattern of results with those patients with heart failure and atrial fibrillation having poorer cognitive performance than those with heart failure in sinus rhythm. Cognitive impairment was also more common in patients with cardiac disease (either coronary artery disease or heart failure) than age-, sex- and education-matched healthy controls, even after adjustment for common vascular risk factors.
Resumo:
Failure to detect a species at sites where it is present (i.e. imperfect detection) is known to occur frequently, but this is often disregarded in monitoring programs and metapopulation studies. Here we modelled for the first time the probability of patch occupancy by a threatened small mammal, the southern water vole (Arvicola sapidus, while accounting for the probability of detection given occupancy. Based on replicated presence sign surveys conducted in autumn (November–December 2013) and winter (February–March 2014) in a farmland landscape, we used occupancy detection modelling to test the effects of vegetation, sampling effort, observer experience, and rainfall on detection probability. We then assessed whether occupancy was related to patch size, isolation, vegetation, or presence of water, after correcting for imperfect detection. The mean detection probabilities of water vole signs in autumn (0.71) and winter (0.81) indicated that false absences may be generated in about 20–30% of occupied patches surveyed by a single observer on a single occasion. There was no statistical support for the effects of covariates on detectability. After controlling for imperfect detection, the mean probabilities of occupancy in autumn (0.31) and winter (0.29) were positively related to patch size and presence of water, and negatively so, albeit weakly, to patch isolation. Overall, our study underlined the importance of accounting for imperfect detection in sign surveys of small mammals such as water voles, pointing out the need to use occupancy detection modelling together with replicate surveys for accurately estimating occupancy and the factors affecting it.
Resumo:
School failure is a chronic problem in many developing countries and in some developed as Portugal due to factors like cognitive deficiencies of children, an inadequate family environment, low SES and bad teaching methods or school organization. It is important to develop effective and simple intervention strategies able to cope with the problem at an individual level independently of the cause. The general objective of the following study is to develop behavioral training techniques to help children with problems of school failure. 6 - 12 years old children attending ISCED 1, with academic difficulties because of family problems, social exclusion (living in poverty or belonging to an ethnic minority) or poor schooling were trained. Cognitive-behavioral techniques that have been widely used to train persons with intellectual, sensorial, physical or social deficiencies were applied. Results are evaluated in terms of % of attained objectives, time, and (subjective) teacher satisfaction. Some results of individual children are shown. Training programs seem to be successful independently of the (mostly unknown) cause of failure of the trained subject.
Resumo:
Students perceive online courses differently than traditional courses. Negative perceptions can lead to unfavourable learning outcomes including decreased motivation and persistence. Throughout this review, a broad range of factors that affect performance and satisfaction within the online learning environment for adult learners will be examined including learning outcomes, instructional design and learner characteristics, followed by suggestions for further research, and concluding with implications for online learning pertinent to administrators, instructors, course designers and students. Online learning may not be appropriate for every student. Identifying particular characteristics that contribute to online success versus failure may aid in predicting possible learning outcomes and save students from enrolling in online courses if this type of learning environment is not appropriate for them. Furthermore, knowing these learner attributes may assist faculty in designing quality online courses to meet students’ needs. Adequate instructional methods, support, course structure and design can facilitate student performance and satisfaction.
Resumo:
Bone marrow is organized in specialized microenvironments known as 'marrow niches'. These are important for the maintenance of stem cells and their hematopoietic progenitors whose homeostasis also depends on other cell types present in the tissue. Extrinsic factors, such as infection and inflammatory states, may affect this system by causing cytokine dysregulation (imbalance in cytokine production) and changes in cell proliferation and self-renewal rates, and may also induce changes in the metabolism and cell cycle. Known to relate to chronic inflammation, obesity is responsible for systemic changes that are best studied in the cardiovascular system. Little is known regarding the changes in the hematopoietic system induced by the inflammatory state carried by obesity or the cell and molecular mechanisms involved. The understanding of the biological behavior of hematopoietic stem cells under obesity-induced chronic inflammation could help elucidate the pathophysiological mechanisms involved in other inflammatory processes, such as neoplastic diseases and bone marrow failure syndromes.
Resumo:
The objectives of this study were to develop a questionnaire that evaluates the perception of nursing workers to job factors that may contribute to musculoskeletal symptoms, and to evaluate its psychometric properties. Internationally recommended methodology was followed: construction of domains, items and the instrument as a whole, content validity, and pre-test. Psychometric properties were evaluated among 370 nursing workers. Construct validity was analyzed by the factorial analysis, known-groups technique, and convergent validity. Reliability was assessed through internal consistency and stability. Results indicated satisfactory fit indices during confirmatory factor analysis, significant difference (p < 0.01) between the responses of nursing and office workers, and moderate correlations between the new questionnaire and Numeric Pain Scale, SF-36 and WRFQ. Cronbach's alpha was close to 0.90 and ICC values ranged from 0.64 to 0.76. Therefore, results indicated that the new questionnaire had good psychometric properties for use in studies involving nursing workers.
Resumo:
To evaluate vaginal microbiological and functional aspects in women with and without premature ovarian failure (POF) and the relationship with sexual function. A cross-sectional study of 36 women with POF under hormonal therapy who were age-matched with 36 women with normal gonadal function. The vaginal tropism was assessed through hormonal vaginal cytology, vaginal pH and vaginal health index (VHI). Vaginal flora were assessed by the amine test, bacterioscopy and culture for fungi. Sexual function was evaluated through the questionnaire Female Sexual Function Index (FSFI). Women in both groups were of similar age and showed similar marital status. The two groups presented vaginal tropic scores according to the VHI but the tropism was worse among women in the POF group. No difference was observed with respect to hormonal cytology and pH. Vaginal flora was similar in both groups. Women with POF showed worse sexual performance with more pain and poorer lubrication than women in the control group. The VHI, the only parameter evaluated showing statistical difference between the groups, did not correlate with the domains of pain and lubrication in the FSFI questionnaire. These findings suggest that the use of systemic estrogen among women with POF is not enough to improve complaints of lubrication and pain despite conferring similar tropism and vaginal flora. Other therapeutic options need to be evaluated.
Resumo:
To analyze associations between mammographic arterial mammary calcifications in menopausal women and risk factors for cardiovascular disease. This was a cross-sectional retrospective study, in which we analyzed the mammograms and medical records of 197 patients treated between 2004 and 2005. Study variables were: breast arterial calcifications, stroke, acute coronary syndrome, age, obesity, diabetes mellitus, smoking, and hypertension. For statistical analysis, we used the Mann-Whitney, χ2 and Cochran-Armitage tests, and also evaluated the prevalence ratios between these variables and mammary artery calcifications. Data were analyzed with the SAS version 9.1 software. In the group of 197 women, there was a prevalence of 36.6% of arterial calcifications on mammograms. Among the risk factors analyzed, the most frequent were hypertension (56.4%), obesity (31.9%), smoking (15.2%), and diabetes (14.7%). Acute coronary syndrome and stroke presented 5.6 and 2.0% of prevalence, respectively. Among the mammograms of women with diabetes, the odds ratio of mammary artery calcifications was 2.1 (95%CI 1.0-4.1), with p-value of 0.02. On the other hand, the mammograms of smokers showed the low occurrence of breast arterial calcification, with an odds ratio of 0.3 (95%CI 0.1-0.8). Hypertension, obesity, diabetes mellitus, stroke and acute coronary syndrome were not significantly associated with breast arterial calcification. The occurrence of breast arterial calcification was associated with diabetes mellitus and was negatively associated with smoking. The presence of calcification was independent of the other risk factors for cardiovascular disease analyzed.