In a northern European climate a typical solar combisystem for a single family house normally saves between 10 and 30 % of the auxiliary energy needed for space heating and domestic water heating. It is considered uneconomical to dimension systems for higher energy savings. Overheating problems may also occur. One way of avoiding these problems is to use a collector that is designed so that it has a low optical efficiency in summer, when the solar elevation is high and the load is small, and a high optical efficiency in early spring and late fall when the solar elevation is low and the load is large.The study investigates the possibilities to design the system and, in particular, the collector optics, in order to match the system performance with the yearly variations of the heating load and the solar irradiation. It seems possible to design practically viable load adapted collectors, and to use them for whole roofs ( 40 m2) without causing more overheating stress on the system than with a standard 10 m2 system. The load adapted collectors collect roughly as much energy per unit area as flat plate collectors, but they may be produced at a lower cost due to lower material costs. There is an additional potential for a cost reduction since it is possible to design the load adapted collector for low stagnation temperatures making it possible to use less expensive materials. One and the same collector design is suitable for a wide range of system sizes and roof inclinations. The report contains descriptions of optimized collector designs, properties of realistic collectors, and results of calculations of system output, stagnation performance and cost performance. Appropriate computer tools for optical analysis, optimization of collectors in systems and a very fast simulation model have been developed.

Background: Acute myocardial infarction (AMI) is a major public health concern. There are limited recent national-level population-based epidemiological data on AMI in England. As a result, the current burden of disease is difficult to quantify. Aim: This thesis addresses gaps in knowledge on AMI in England. It aims to provide a comprehensive analysis of AMI epidemiology over the last decade. Methods: This is a population-based study using person-linked routine hospital and mortality data for England for the period from 1 April 1998 to 31 March 2008. Main outcome measures include: trends in event rate, case fatality, and mortality for AMI, as well as trends in characteristics of, and hospital care for, the AMI patient population between 1999 and 2007; rates of occurrence and case fatality for first and recurrent AMI in 2007; and five-year survival and risk of a second AMI for 2003 to 2007. Results: Total age-standardised AMI mortality rate fell by around half, while the age-standardised event rate and case fatality rate each declined by around one third between 1999 and 2007. Approximately half of the decline in AMI mortality was attributed to a decline in event rate and half to improved survival. During the 2000s, the hospitalised AMI patient population became increasingly elderly, presented with more comorbidities, underwent more revascularisation procedures, and spent less time in hospital. In 2007, approximately 90,000 AMIs occurred in England, of which around one third were fatal, one in seven were reinfarctions, and three quarters were AMIs in those aged 65 years and older. Among 30-day survivors of a first AMI, around one in three men and one in four women died within five years, and about one in eight men and one in six women experienced a second AMI in the same time period. Conclusions: There have been substantial improvements in AMI occurrence, survival, and mortality over the last decade in England. This was driven by improvements in prevention and acute medical treatment. The results in this thesis emphasise the importance of both.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Background The period of adolescence is typical for first experiments and initiation of substance use. The onset of experiments emerges between 11 and 15 years of age according to different authors. Although many adolescents end with experiments, there is still a group of those who proceed to regular use. Frequent, regular and especially heavy substance use represents various risks in many aspects of individual's life. According to various studies earlier onset of substance use may predict serious difficulties in adult stages of life. Important and currently widely discussed question is differences in substance use between boys and girls. Aims To identify the age of cigarette, alcohol and cannabis use onset according to gender. To find out prevalence of use among boys and girls. To find out whether incidence of substance use is higher during school year or summer holidays. Methods The ESPAD questionnaire was used for data collection, which was realized in the period of 34 months from August 2007 until June 2010. Indicators were defined for categories of cigarette smoking, alcohol drinking and experience with cannabis. For clarification of the given hypothesis statistical analyses in Microsoft Office Excel 2007 were used - descriptive statistics, contingency tables, Fisher's F-test and (Student)...

This work will first introduce the problems related to the colorectal cancer - its epidemiology and screening possibilities. Next the main topic is addressed - i.e. to ascertain the influence of national screening programmes for colorectal cancer on really observed data of lethality and incidence of this disease. Group of so-called APC models was selected as a useful tool for this purpose. Applying these methods on data of The National Oncological Registry of the Czech Republic for the period between 1980 till 2009 this work aims to prove expected reducing effect of area-wide screening programme on incidence and lethality related to colorectal cancer. Using the AP model and data of previous period before the screening introduction (i.e. 1980-1999) the values of incidence and lethality were predicted for the period in question (i.e. 2000-2009). Mere comparison of this predicted values with really observed data showed that real lethality and incidence was significantly lower in both sexes as compared to the model without the screening intervention. Difference between predicted and real data corroborates positive influence of colorectal cancer screening.

In this dissertation, we consider the problem of partitioning a set of k population with respect to a control population. For this problem some multistage methodologies are proposed and their properties are derived. Using the Monte Carlo simulation techniques, the small and moderate sample size performance of the proposed procedure are studied. We have also considered at statistical surveillance of various cancers in Louisiana.

This study investigated foundation phase educators’ perceptions of Attention Deficit Hyperactivity Disorder (ADHD). The educators’ views on the causes, appropriate interventions and incidence rates of ADHD were examined. A sample of 140 foundation phase educators from mainstream private and public schools participated in the study. The educators completed a self-developed questionnaire that had been piloted by the researcher. Descriptive statistics were used to analyze the quantitative data, in conjunction with t-tests to ascertain the differences in responses between public and private school educators. Thematic content analysis was used to identify the main categories and themes that emerged form the open-ended questions. The results revealed that the educators had a limited understanding of ADHD, in terms of what it is as well as its causes. In addition, it emerged that the educators preferred medication as the intervention method despite being aware of additional intervention methods. A comparison of the private and public school educators’ results indicated no significant difference in the educators’ perceptions regarding the cause, interventions or incidence rate of ADHD. These findings are discussed in relation to empirical studies and suggestions for future research are presented.

Thesis (Ph.D.(Public Health))--University of the Witwatersrand, Faculty of Health Sciences, 2012. / Measuring HIV incidence has proved challenging over the years. A number of serological HIV assays have been proposed, and among these, the BED Capture Enzyme Immunoassay (CEIA) is one of the more widely used. Although the assay performs well among known seroconverting panels, it has been shown to classify some long term infected patients as being recently infected. Information on the performance of the BED assay among low CD4 cell count patients and those on antiretroviral therapy is limited. The risk of onwards transmission of HIV has been reported to be elevated around the seroconversion period compared to the chronic stage of infection. RNA viral load has been reported as the strongest predictor of HIV transmission compared to other HIV markers. Understanding how these markers influence the relationship between the likelihood of being recently infected and the BED assay might help in understanding some of the shortcomings of the BED assay. The main aim of this study was to understand the properties of the BED assay. The performance of the BED assay among advanced HIV disease patients and the influence of ART on BED levels once patients started treatment was investigated. The BED assay and CD4 cell count were used to quantify the risk of in utero and intrapartum transmission to their infants among women believed to have seroconverted during pregnancy. The influence of viral load, haemoglobin and mid-upper arm circumference was investigated on the relationship between the probability of being recently infected and BED ODn levels. Methods Cryopreserved plasma samples from HIV patients on the national antiretroviral treatment (ART) rollout programme at Tygerberg Hospital HIV clinic, South Africa, iv were used to investigate the effect of ART on BED ODn levels once patients commenced treatment. Mixed effect logistic regression models accounting for multiple readings per patient were used. To investigate the risk associated with seroconversion during pregnancy HIV seropositive women who had just given birth were classified into mutually exclusive groups according to their likelihood of having recently seroconverted using BED and CD4 cell count levels. Multinomial logistic regression models adjusting for other factors were used to assess the risk of MTCT in utero and intra-partum infection comparing these groups. To investigate the relationship between BED ODn levels and the probability of being recently infected, BED data from known HIV infected women and women who seroconverted over a 2 year period was used. Fractional polynomial regression models that allow for non-linear functions to be fitted were used, and the influence of viral load, haemoglobin and mid-upper arm circumference was assessed through multi-variable models. Data from the Zimbabwe Vitamin A for Mothers and Babies (ZVITAMBO) project, a double blinded treatment-placebo trial was used for these last two objectives. Results Patients with very low CD4 cell counts were more likely to test false recently infected according to the BED assay than other patients. ART changed BED ODn kinetics among HIV patients on treatment. Over half of advanced disease stage patients were likely to be classified as being recently infected according to the BED assay 2 years into ART treatment. v Women who seemed to have seroconverted during pregnancy had elevated risk of transmitting HIV in-utero compared to chronic HIV patients. BED and CD4 cell count were not predictive of risk of intra-partum infections attributed to seroconversion during pregnancy. The relationship between the probability of being recently infected with HIV and BED ODn levels was described better using Fractional Polynomial regression models than using a linear model in BED ODn or a model in which the BED ODn was categorised. Viral load and haemoglobin were important independent predictors of incident infections. Conclusions If the BED assay is to be used for HIV incidence estimations patients on ART should be accounted for. The BED assay together with other HIV serological markers can be used as prognostic tools to assess the risk of HIV transmission. The risk of in-utero transmission of HIV is higher among women who seroconvert during pregnancy. Repeat HIV testing among pregnant women may help in identifying women who seroconvert during pregnancy, and these women will benefit from Prevention of Mother-to-Child transmission (PMTCT) programmes. It was found that additional markers such as viral load and haemoglobin did not alter the relationship between the probability of having been recently infected and BED ODn.

As úlceras de pressão (UP) representam um grave problema para os pacientes hospitalizados, especialmente em termos de sofrimento pessoal e econômico, e um desafio não só para os enfermeiros, mas para toda a equipe interdisciplinar. Os objetivos deste estudo foram identificar e analisar os índices de prevalência e incidência de UP, nas unidades de Clínica Médica, Cirúrgica, UTI e Semi Intensiva do Hospital Universitário da USP, bem como, estabelecer as possíveis associações com as características sócio demográficas e clínicas da clientela. Após aprovação do Comitê de Ética e Pesquisa do HU, procedeu-se à coleta de dados em duas etapas: enquanto os dados da prevalência foram levantados num único dia da semana, os relacionados à incidência, durante três meses consecutivos. Para tanto, o exame físico de todos os pacientes internados e de todos os pacientes em risco para o desenvolvimento de UP, era realizado, respectivamente para os estudos da prevalência e incidência. A avaliação de risco para o desenvolvimento de UP foi feita através da Escala de Braden, tendo como nota de corte o escore inferior ou igual a 16. No estudo da prevalência, dos 102 pacientes avaliados, 19 desenvolveram UP, acarretando índice de 18,63%. Dentre os pacientes que apresentavam UP, houve predomínio do sexo feminino (52,63%), da raça branca (89,47%), de pacientes não fumantes (68,42%), com tempo de internação superior a 10 dias, principalmente por doenças do sistema cardiovascular ou respiratório (por doenças de base ou associadas), além de lesões no estágio I (51,85%) e na região sacra (22,22%). A idade média de 71,53 (DP=15,75) anos e o tempo médio de internação (12,31) dos pacientes com UP mostraram-se significativamente superiores àqueles exibidos pelos pacientes sem UP (p<0,001 e p=0,044, respectivamente). No estudo da incidência, dos 211 pacientes de risco acompanhados, 84 desenvolveram um total de 134 UP, acarretando índice de 39,81%. Os pacientes com UP caracterizaram-se por predomínio do sexo masculino (52,28%), da raça branca (80,95%) e de não fumantes (73,81), e as úlceras predominaram no estágio II (52,98%) e também em região sacra (33,58%), não sendo observadas UP nos estágios III ou IV. A idade média desses pacientes foi de 70,31 anos (DP=16,44), e houve diferença estatisticamente significante entre as idades dos pacientes com e sem UP, mostrando-se novamente superiores para os pacientes com UP. Além disso, a idade apresentou ainda, correlações estatisticamente significativas, positiva com a incidência e negativa com a umidade, ambas de fraca intensidade, sugerindo que as maiores incidências ocorrem entre os pacientes idosos e que estes tendem a apresentar maiores escores na sub escala umidade da escala de Braden. Embora a maioria dos pacientes com UP (50 ou 59,52%) tenha apresentado escore menor ou igual a 16, ou seja, risco para desenvolvimento de UP, os índices de prevalência e incidência encontrados neste estudo, quando comparados aos estudos internacionais, mostram-se elevados. Os resultados indicam não somente a urgente necessidade da implantação de um programa de prevenção e tratamento de UP na instituição, como contribuem, metodologicamente, para que outros serviços possam estabelecer tal tipo de investigação, para a ampliação do conhecimento acerca desse problema no país. / Pressure Ulcer (PU) represents a great problem for hospitalized patients, especially concerning economic and personal suffering, and this is a hallenge not only for registered nurses (RN) but also for the interdisciplinary staff. The goals for this study are to identify and to analyze the PU prevalence and incidence in the clinical, surgical, intensive care unit and semi-intensive units at the University Hospital of Sao Paulo University, as well as establish possible association with social demographic and clinical characteristics of the patients. After approval of the Ethical and Research Committee of the University Hospital, the collection of data took place in two stages. While the prevalent information was surveyed in only one day, the incidence took three months to accomplish. A physical examination was performed on all the interned patients and all the others that had a risk of developing the PU to study the predominance of the occurrence. An evaluation of the chance of developing PU was assessed using the Braden Scale with a cutoff score of less than or equal to 16. In this study of prevalence,from the 102 patients, 19 developed PU, an index of 18.63%. Among those patients that developed PU, 52.63% were female, 89.47% white race, 68,42% non-smoker patients, with more than 10 days of internment period mainly with cardiac or respiratory diseases (or associated illnesses), beside the lesions at stage I (51.85%) and on the sacral region (22.22%). The average age was 71,53 years old (DP=15.75) and the average time of internment was 12,31 days for the patients with PU, and it was significantly greater than those patients without the PU (p<0,001 and p=0,044 respectively). In the incidence study of 211 patients with risks to develop PU, 84 developed it, with a total of 134 PU, an index of 39.81%, Those with PU were predominant male (52.38%), of white race(80.95%), and non-smokers (52.98%). The ulcers were predominant at stage II, and also on the sacral region (33.58%), not having been found PU at stages III and IV. The average age of these patients was 70.31 years old (DP=16.44). The results showed significant statistical difference between the ages of patients with and without PU, again superior for those patients with PU. Besides, the age presented positive correlation statistically significant and negative with moisture, both with low intensity, suggesting that there are more incidences occurring with elderly patients who tend to present bigger score in the Moisture Subscale of the Braden Scale. Although, the majority of the patients with PU (50 or 59.52%) presented a score of 16 or less, it means, risk to develop PU, the prevalence and incidence indexes found in these studies were high when compared with the international studies. The results indicate, not only, an urgent need of implantation of a preventive program and treatment of PU in the institution, but also contribute, methodologically, that other services be established, like type of investigation, to amplify the knowledge of this problem in the country.

O presente estudo tem o propósito de estudar a incidência da sífilis em um município de pequeno porte, localizado no interior do Estado de São Paulo, como cenário de pesquisa para uma realidade que acomete todo o país. Sua análise metodológica foi baseada em entrevistas realizadas com os profissionais de saúde responsáveis pelo cuidado a pacientes com sífilis adquirida, sífilis em gestante (SG) e sífilis congênita (SC) sobre suas percepções profissionais desta Infecção Sexualmente Transmissível (IST). Realizou-se também uma análise aos bancos de dados do governo os quais dispõe de indicadores sobre a incidência da SG e SC no município de estudo e municípios próximos que pertencem a sua regional de saúde. Os resultados sugeriram que o município de Cajobi-SP (local de estudo) e municípios circunvizinhos apresentam subnotificação dos casos potenciais, se comparados as taxas apresentadas por municípios como São Paulo, Campinas e Barretos. Observou-se que a prescrição do tratamento a pacientes com sífilis estabelecido pelo Ministério da Saúde (MS) não atingem mesmo os casos notificados. Acredita-se que há falhas no controle fidedigno de notificações, o que configura subnotificação, bem como na assistência pré-natal. Os dados coletados no banco de dados de indicadores demonstrou que os munícipios da região, em sua grande prevalência não possuem o número de notificações correspondentes ao seu número populacional, o que também aponta para a subnotificação. Dessa maneira, conclui-se que investimentos direcionados a essa situação pelo MS são inadequados e insuficientes. Uma avaliação urgente da situação deve ser realizada para acionar planos que busquem resolver este problema, incluindo uma qualificação técnica de qualidade para equipes técnicas de referência e da Estratégia de Saúde da Família (ESF). / This Research has aims to study the incidence of syphilis in a small county located in the interior of the State of São Paulo, as a research setting for a reality that affects the whole country. Methodological analysis was based on interviews with health professionals responsible for the care of patients with syphilis, syphilis in pregnant women (SG) and congenital syphilis (SC) on their professional perceptions of this Sexually Transmitted Infections (STIs). An analysis was made of government databases which provides indicators on the incidence of SG and SC in the studied city and in nearby municipalities what belongs to the same regional health. The results imply that the city of Cajobi-SP (study site) and the surrounding municipalities have potential underreporting of cases when compared to the rates presented by municipalities such as São Paulo, Campinas and Barretos. It was observed that the treatment prescription to patients with syphilis determined by the Ministry of Health (MS) really do not reach the reported cases. It is believed that there are faults in the Control Trusted Notifications what constitutes underreporting as well as prenatal care. The data collected in the database of indicators showed that the municipalities of the region in their high prevalence do not have the number of notifications corresponding to their population numbers, which also points to underreporting. Therefore, we conclude that investments directed to this situation by the Ministry of Health are inadequate and insufficient. An urgent assessment of the situation must be carried out to trigger plans that seek to solve this problem, including a quality technical qualification for technical reference teams and the Family Health Strategy (ESF).