Spelling suggestions: "subject:"diseases -- epidemiology"" "subject:"diseases -- épidemiology""
61 |
Fatores associados a vacinação contra influenza e doença pulmonar em idosos / Factors associated with vaccination against influenza and pulmonary disease in the elderlyFrancisco, Priscila Maria Stolses Bergamo, 1973- 18 October 2006 (has links)
Orientador: Maria Rita Donalisio Cordeiro / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-07T11:53:53Z (GMT). No. of bitstreams: 1
Francisco_PriscilaMariaStolsesBergamo_D.pdf: 1732128 bytes, checksum: e40308a72ae69b30999c757a5f111ac4 (MD5)
Previous issue date: 2006 / Resumo: O aumento da proporção de idosos no país associado à maior longevidade modificou o perfil de saúde da população com considerável aumento da demanda por prevenção e assistência à saúde nas faixas etárias mais avançadas. Neste contexto, destaca-se a importância relativa das doenças respiratórias nos idosos, com impacto econômico e social. O objetivo deste estudo foi investigar os fatores associados à vacinação contra influenza e doença pulmonar em idosos, com a utilização de diferentes técnicas de análise em estudos transversais de delineamento complexo. Os dados foram obtidos do "Inquérito de saúde de base populacional em municípios do Estado de São Paulo" (ISA-SP), cuja coleta foi realizada entre 2001 e 2002, e se referem a 1.958 registros de indivíduos de 60 anos e mais, analisados por meio de regressão logística e regressão de Poisson. Os resultados desta tese são apresentados em capítulos que se referem a três artigos publicados em revistas científicas. No primeiro artigo, "Fatores associados à vacinação contra influenza em idosos", os achados apontaram maior adesão à vacinação contra influenza entre os indivíduos com idade igualou superior a 70 anos (OR = 1,47; IC 95%: 1,09 -:- 1,99) e entre os hipertensos (OR = 1,39; IC 95%: 1,03 - 1,87), enquanto os idosos com nove anos ou mais de estudo referiram menor adesão à vacinação (OR = 0,64; IC 95%: 0,41 - 0,98). No segundo trabalho, "Vacinação contra influenza em idosos por área de residência: prevalência e fatores associados", pôde-se verificar diferenças no perfil do idoso quanto à referência de vacinação segundo subgrupos específicos e locais de residência. Nos municípios mais populosos apenas a menor escolaridade esteve associada à vacinação referida (RP = 1,26; IC 95%: 1,02-1,54), já na área composta pelos municípios menos populosos, idade mais avançada (RP = 1,15; IC 95%: 1,02-1,31), hipertensão arterial (RP = 1,21; IC 95%: 1,02-1,45), diabetes (RP = 1,16; IC 95%: 1,01-1,33) e doença crônica de pulmão (RP = 1,30; IC 95%: 1,03-1,64) referidas, estiveram associadas. No estudo, "Fatores associados à doença pulmonar em idosos", os resultados indicaram associação independente entre doença pulmonar referida e tabagismo (RP = 2,03; IC 95%: 1,39 - 2,97), uso de medicamentos (RP = 2,05; IC 95%: 1,11 - 3,79), auto-avaliação do estado de saúde atual como ruim ou muito ruim (RP = 1,89; IC 95%: 1,20 - 2,96) e depressão, ansiedade ou problemas emocionais (RP = 1,86; IC 95%: 1,11 - 3,10). Com o envelhecimento e a crescente importância das doenças respiratórias entre os idosos, os achados desse estudo apontam para a necessidade de ações que priorizem a manutenção da saúde do idoso, por meio de programas de promoção e prevenção que considerem as especificidades desse segmento / Abstract: The increase in the proportion of elder1y persons in Brazil, associated to increased longevity, has modified the health profile of the population, with a considerable increase in the demand for prevention and healthcare among the older age groups. In this context, the relative importance of respiratory diseases among the elder1y, along with its social and economic impact, is worthy of note. The aim of the present study was to investigate the factors associated with influenza vaccination and pulmonary disease in the elder1y population, using different analytical techniques in cross-sectional studies with complex design.The data were obtained from the Population-based survey of municipalities of the State of Sao Paulo (ISA-SP), whose data collection took place between 2001 and 2002 and inc1uded 1.958 records of subjects aged 60 years or older, and were analyzed using logistic regression and Poisson regression.The results of the present thesis are presented as chapters that refer to artic1es published in scientific journals. In the first article, "Factors associated with influenza vaccination among elderly persons", our findings indicate greater adherence to influenza vaccination among subjects aged 70 years or older (OR = 1.47; 95%CI: 1.09 - 1.99) and among subjects with hypertension (OR = 1.39; 95%CI: 1.03 - 1.87), whereas elder1y subjects with nine or more years of schooling reported lesser adherence to vaccination (OR = 0.64; 95%CI: 0.41- 0.98). In the second paper, "Influenza vaccination among elderly persons according to place of residence: prevalence and associated factors", we observed differences in subject profile in tenns of self-reported vaccination according to specific subgroups and places of residence. In more populous municipalities, only lesser schooling (PR = 1.26; 95%CI: 1.02-1.54) was associated with vaccination. Among the less densely populated municipalities, older age (pR = 1.15; 95%CI: 1.02-1.31) and 'reported hypertension .(PR = 1.21; 95%CI: 1.02-1.45), diabetes (pR = 1.16; 95%CI: 1.01-1.33), and chronic pulmonary disease (PR = 1.30; 95%CI: 1.03-1.64) were associated with the outcome. In the paper entitled "Factors associated with pulmonary disease among the elderly," our results indicate independent associations between self-reported pulmonary disease and smoking (pR = 2.03; 95%CI: 1.39 - 2.97), medication use (pR = 2.05; 95%CI: 1.11 - 3.79), self-perception of current health status as poor or very poor (RP = .1.89; 95%CI: 1.20 2.96), and depression, anxiety, or emotional disorders (pR = 1.86; 95%CI: 1.11 - 3.10).With the aging of the population, and the increasing importance of respiratory diseases among the elderly, the findings of the present study indicate a need for measures that prioritize the maintenance of health among this population, through promotion and prevention programs that take into account the specificities of this segment / Doutorado / Epidemiologia / Mestre em Saude Coletiva
|
62 |
The Role of Cardiovascular Morbidity in the Relationship between Ambient Air Pollution Exposure and Adverse COVID-19 OutcomesKannoth, Sneha January 2025 (has links)
The COVID-19 pandemic elucidated geographical disparities in COVID-19 burden on a globalscale. Geographical disparities in adverse COVID-19 outcomes may suggest population-level drivers of disease, such as environmental exposures. Epidemiological literature provides strong evidence that greater exposure to ambient air pollution, an environmental exposure, is associated with a greater risk of COVID-19 hospitalization and fatality. The pathways by which ambient air pollution exposure influences adverse COVID-19 outcomes are currently unknown. I propose that cardiovascular morbidity is relevant in this pathway, given that cardiovascular morbidity is a predominant risk factor of adverse COVID-19 outcomes, and there are strong and consistent associations between air pollution and cardiovascular morbidity. I suggest that the role of cardiovascular morbidity will be different for historical air pollution (period > 30 days) and short-term air pollution (period < 30 days). By proposing clear causal structures for the relationship between air pollution and adverse COVID-19 outcomes, we can explicate how air pollution leads to greater COVID-19 burden and address the larger goal of reducing geographic disparities in adverse COVID-19 outcomes.
This dissertation is comprised of three specific aims. For the first aim, I performed a systematic review of the literature that examined the relationship between ambient air pollution and individual-level adverse COVID-19 outcomes. I identified if and how researchers conceptualized the causal role of comorbidities, specifically cardiovascular morbidities, in the relationship between air pollution and adverse COVID-19 outcomes. For the second aim, I examined if cardiovascular morbidity mediates the relationship between historical air pollution and adverse COVID-19 outcomes. For the third aim, I examined if there was evidence of synergistic interaction between short-term air pollution and cardiovascular morbidity in influencing the risk of adverse COVID-19 outcomes, suggesting that the effect of both short-term air pollution and cardiovascular morbidity on adverse COVID-19 is greater than the sum of the individual effects.
In conducting the first aim, I used Covidence, a software used to manage systematic reviewstudies, to identify studies that examined the relationship between ambient air pollution exposure and individual-level adverse COVID-19, using the Embase, MEDLINE, and Web of Science databases. In conducting the empirical aims, I used a retrospective cohort study design using INSIGHT-Clinical Research Network (CRN) data, a harmonized repository of inpatient electronic health records in New York City (NYC) across metropolitan healthcare systems (3/1/2020-2/28/2021). INSIGHT-CRN included data pertaining to sociodemographics, diagnoses, outcomes, and residential ZIP Code to link air pollution exposure.
For the second aim, I used the New York City Community Air Survey (NYCCAS) to estimate historical air pollution exposure to particulate matter (PM2.5), black carbon (BC), nitrogen dioxide (NO₂), and ozone (O₃) on a ZIP Code level (2009-2019). For the third aim, I used the 2020 Environmental Protection Agency (EPA) Community Multiscale Air Quality (CMAQ) downscaler modeled data, which estimated 2020 daily exposure to PM2.5 and O3 on a census tract level. I aggregated the census tract data to ZIP Code using a spatial weighting approach and estimated short-term air pollution as a 7-day average of daily PM2.5 and O3 exposure prior to patient hospitalization.
For the first aim, the systematic review included 42 studies that examined the relationship between ambient air pollution, such as exposures to PM2.5, NO₂, and O₃, and individual-level adverse COVID-19, such as hospitalization, intensive care unit (ICU) admission, intensive respiratory support (IRS), and fatality. The studies were primarily retrospective cohort study designs, and were conducted in the United States and Europe (2020 to 2021). The majority of studies adjusted for cardiovascular morbidity without causal role specification, whereas some studies identified cardiovascular morbidity as a mediator or an effect modifier.
For the second aim, I found evidence of cardiovascular morbidity mediating the relationship between historical air pollution and risk of acute respiratory distress syndrome (ARDS), dialysis use, ventilation use, and COVID-19 fatality, but not risk of pneumonia from March to June 2020, within areas of greater hospital catchment. Indirect effects suggest that historical air pollution increases the risk of atrial fibrillation and myocardial infarction, which increases risk of adverse COVID-19.
For the third aim, I found evidence of synergistic interaction between short-term PM2.5 and presence of cardiovascular morbidities for only risk of COVID-19 pneumonia, in the latter half of 2020. Overall, there was evidence that cardiovascular morbidity mediates the relationship betweenhistorical air pollution and more severe COVID-19 outcomes, while cardiovascular morbidity synergistically interacts with short-term air pollution for risk of acute respiratory infections, such as pneumonia. This dissertation assesses the pathways by which air pollution may influence risk of adverse COVID-19, in better examining the causal role of cardiovascular morbidity. Knowledge gained could be used to mitigate population-level vulnerabilities to air pollution, and encourage population-level pandemic preparedness in the future.
|
63 |
Epidémiologie nutritionnelle: quels enjeux dans une société multiculturelle ?Bazelmans, Christine 08 June 2006 (has links)
Les maladies chroniques (dont les maladies cardio-vasculaires (MCV)) constituent dans la majorité des pays en Europe voire dans le monde, une des principales causes de mortalité et de morbidité. En Belgique, ces pathologies sont responsables de 37% des décès (33% des décès chez les hommes et 40% chez les femmes) .<p><p>Les études épidémiologiques ont montré que certaines populations sont plus susceptibles que d’autres de développer ou de décéder des maladies cardio-vasculaires (1). Pendant longtemps, l’Europe a été caractérisée par des écarts importants de mortalité cardio-vasculaire entre le Nord, plus à risque, et le Sud. Ces différences entre populations s’expliquent par des facteurs génétiques, environnementaux, sociaux et culturels. <p><p>Parmi les facteurs culturels et environnementaux, des travaux scientifiques montrent, depuis plusieurs dizaines d’années, que l’alimentation et l’état nutritionnel participent de façon essentielle au développement et à l’expression clinique des maladies dans l’ensemble des pays industrialisés. Un équilibre nutritionnel, une consommation alimentaire variée, avec une répartition satisfaisante des quantités ingérées permettent de préserver un bon état de santé. <p><p>Les études épidémiologiques interethniques ont joué un rôle important dans l’avancée de la recherche de ces facteurs. Les études d’observation révèlent que lorsque des sujets d’un groupe ethnique particulier changent d’environnement, leur statut physique change au contact du nouvel environnement et diffère généralement de ceux restés dans le pays d’origine. La comparaison des taux de mortalité et de morbidité des immigrés de longue date aux taux observés dans le pays d’origine permet d’étudier la contribution des facteurs génétiques et environnementaux dans les variations de morbidité et de mortalité.<p><p>Les différences de morbidité et de mortalité entre ethnies ont été largement documentées pour les immigrés hispaniques, africains et sud-asiatiques en Amérique du Nord et en Grande Bretagne. Ces études ont montré que le profil de santé des immigrés est influencé tant par l’environnement du pays de naissance que par celui du pays d’accueil. L’influence de ces deux environnements peut donner lieu à 3 modèles de morbidité et de mortalité :la sous-mortalité (principalement observée parmi les immigrés de première génération issus de pays moins développés), la convergence (mortalité ou morbidité égale. Ce modèle concerne essentiellement les immigrés de seconde génération) et le dépassement (sur-mortalité ou sur-morbidité). <p><p>La santé des immigrés en Belgique est mal connue et peu étudiée. Dans la majorité des statistiques sanitaires comme dans les recherches épidémiologiques, les critères de nationalité et de naissance soit n'apparaissent pas du tout, soit ne font l'objet d'aucune analyse. L'occultation de ces variables a cependant pour conséquence de laisser dans l'ombre des indications précieuses pour la mise en œuvre de politiques de santé publique. <p><p>Bien que d’un intérêt évident en épidémiologie, les études interethniques posent un certain nombre de problèmes méthodologiques. Difficile à traiter, cette question n'en demeure pas moins essentielle à penser. <p> / Doctorat en Sciences de la santé publique / info:eu-repo/semantics/nonPublished
|
64 |
Exploring ethnic inequalities in cardiovascular disease using Hospital Episode StatisticsLiu, Lixun January 2009 (has links)
This thesis is based on a population study conducted to explore ethnic inequalities in cardiovascular disease using Hospital Episode Statistics (HES). The Hospital Episode Statistics have significant potential for health studies for ethnic groups, due to the large number of events from minority ethnic groups, comprehensive clinical information, full England coverage and fine geographical scale. However, the percentage of Finished Consultant Episodes (FCEs) with invalid ethnicity codes is at a high level. This thesis starts by developing a record linkage method and a coding rate method to improve the data quality of ethnicity codes in the HES. This thesis then further examines ethnic inequalities in cardiovascular disease incidence in England at both national and local geographical scales. The patterns of ethnic inequalities in cardiovascular disease appear to have changed little in the last ten years. However, large variations of geographical relative risk of cardiovascular disease were observed for ethnicity-sex groups. The relationships between areal socioeconomic status measured at different geographical scales and ethnic inequalities in different types of cardiovascular disease were also explored. As there are very limited data on the mortality of minority ethnic groups in the UK, few studies have compared the incidence and outcome of cardiovascular disease from the same population. This thesis came up with some novel findings, for example, that people from minority ethnic groups, who generally have increased risk of cardiovascular disease incidence, have better cardiovascular disease survival than white people. The contribution of areal socioeconomic status, distance to treatment sites and cardiovascular disease severity and treatment to the ethnic inequalities in cardiovascular survival was examined. The relationships between socioeconomic status measured at different geographical scales and ethnic inequalities in cardiovascular disease severity and treatment were investigated in this thesis as well.
|
65 |
Genome mapping of malaria resistance genes : the host ligands of PfEMP1Fry, Andrew E. January 2009 (has links)
Erythrocytes infected by mature forms of the Plasmodium falciparum parasite adhere to other components of the vascular space, a behavior considered critical to the pathogenesis of severe malaria. Adhesion is mediated by the P. falciparum erythrocyte membrane protein 1 (PfEMP1), a highly variant antigen expressed by the parasite and subject to switching during the course of an infection. The host ligands of PfEMP1 include CD36, ICAM-1 and the ABO antigens. By employing a series of population- and family-based association studies from multiple African populations, we examined whether variation in the genes underlying these molecules affects susceptibility to severe malaria. Our results suggest that a common frameshift mutation in the ABO glycosyltransferase, responsible for blood group O, is associated with protection from severe malarial phenotypes (P=2x10⁻⁷), particularly severe malarial anaemia. However, we found no significant disease associations with variation in either the ICAM1 or CD36 genes. We focused on two particular functional polymorphisms, the missense ICAM-1Kilifi and the CD36 nonsense mutation T1264G. We genotyped both markers in around 10,000 individuals, but neither demonstrated an association with severe malarial phenotypes. Malaria has been a profound selection pressure shaping human genetic diversity. The last decade has seen the development of several haplotype-based methods to detect signatures of recent positive evolutionary selection. These techniques are potentially invaluable tools in our hunt for genetic variants that protect from life threatening malaria. We used simulations and empirical data from the International HapMap Project to demonstrate the validity of searching for long regions of haplotype homozygosity, as an approach to finding alleles undergoing selective sweeps. We analysed genetic data from a range of populations, particularly those utilized by HapMap, to investigate whether our candidate genes were associated with signals of recent positive selection. We characterized the distribution of a selection event associated with the CD36 1264G allele, focused in Central-West Africa, and demonstrated a novel signal of low population differentiation at the ABO gene, suggestive of longstanding balancing selection. Our work confirms that variation in the host ligands of PfEMP1 modulates severe malaria susceptibility, and highlights the value of using signals of selection, along with functional experiments and genetic association studies, to dissect the biology of severe malaria.
|
66 |
Respiratory health of the informal stone crushers in Dar-Es-Salaam.Kessy, Florian Mathias. January 2010 (has links)
Introduction.
Stone crushing in Dar-es-Salaam Tanzania is largely an informal occupational activity,
with approximately 7000 workers exposed to varying level of respirable dust. A highly
marginalized, self employed, informal stonecrusher is prone to multiple work related risks,
particularly dust related respiratory diseases.
Aim.
This study, the first to be done among informal stone crushers in Southern Africa,
aimed at determining the prevalence of dust related respiratory outcomes and relationships
between these health endpoints and exposure to respirable dust in this sample of stonecrushers.
Methods.
This was primarly a cross-sectional descriptive study with analytic components. This
study analysed a subset of data collected in a health survey of stone crushers in Kigamboni
informal stone quarry in Dar-es-Salaam, Tanzania in 2007. All 200 workers working in the
quarry were interviewed. A subset of 86 and 59 workers underwent exposure assessment and
health assessments (spirometry and chest radiography) respectively. Associations were
investigated between exposure measures and respiratory outcomes.
Results.
The average age of the workers was 36.3 years with 51.5% males participating in the
study. Smoking was common with 30.1% male, 8.25% female smokers, with 2% ex-smokers.
Personal dust sampling showed varying dust levels ranging from 0.5-2.8mg/m3 with geometric
mean of 1.2gm/m3. The exposure duration of workers in the quarry ranged from 1-62 years
with mean of 7.8 years. No single worker was found to use personal protective equipment at
work.
Reported prevalence of doctor diagnosed respiratory diseases was low: pulmonary
tuberculosis (2%), chronic bronchitis (2%), asthma (3%), pneumonia (3%). In contrast, there
was high prevalence of respiratory symptoms: chronic cough (13.5%), phlegm production
(14.5%), productive cough (10%), wheezing (14%), mild breathlessness (9.5% ) and coughing
blood (7.5%). Mean forced expiratory volume in one second (FEV1) and forced vital
capacity (FVC) adjusted for age, height and sex was 2.6L/min and 3.7 L respectively, among
males and 2.1L/min and 3.0L respectively among females.
Adjusted exposure odds ratios for symptoms were statistically significant for mild and
moderate breathlessness with odds ratios of 3.4 and 3.1 respectively.
Linear regression showed statistically significant decline of 2.3mls in FEV1 with years
of exposure while controlling for sex, age, height , doctor diagnosed TB and smoking showing
that with prolonged exposure in the quarry, workers are at a risk of developing obstructive lung
disease. This trend was not evident for FVC.
The majority of films were normal (60.9%), with 19.6% read as 1/0 and 19.9% as 0/1.
Discussion.
This study identified adverse respiratory outcomes among informal stonecrushers,
particularly a high prevalence of respiratory symptoms and clinically important lung function
deficits. These are in keeping with other environment studies where workers were exposed to
respirable dust.
Recommendations.
Urgent policy initiatives for developing cost effective hazard control, engineering
interventions to protect these marginalized self-employed informal sector stonecrushers are
needed. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2010.
|
67 |
A serological survey to determine the prevalence of Brucella Canis infection in dogs within the Nelson Mandela Bay metropolitan in the Eastern Cape, South AfricaEtsebeth, Charné 04 1900 (has links)
The prevalence of Brucella canis in South Africa is unknown and suspected to be under-detected. The majority of dogs in South Africa are not tested for Brucella canis, not only because of the level of awareness of Brucella canis in South Africa, but also because of the lack of clinical suspicion. It is not known how the infection entered South Africa.
Brucella canis, a zoonotic organism that causes canine brucellosis in dogs, is a significant cause of reproductive failure in dogs worldwide. Canine brucellosis is a chronic infectious zoonotic disease whose main etiological agent, the Brucella canis bacterium, are rough, intracellular proteobacteria in the Brucellaceae family. Clinical signs in bitches are mainly infertility and abortion, while in males, epididymitis and orchitis occur. However, discospondylitis may develop in both sexes.
A serological survey was conducted to determine the prevalence of Brucella canis infection in dogs from the Nelson Mandela Bay Metropolitan (NMBM) Port Elizabeth (PE) area. A total of 400 samples were collected, 350 of which were collected in seven different townships and 50 were collected in the three different welfare organisations in the study area.
Of the 400 serum samples collected, 39 (9.75%) tested serologically positive by using the Tube Agglutination Test (TAT), the 2-Mercaptoethanol-TAT (2ME-TAT) or the Compliment Fixation Test (CFT). The results of the CFT showed that nine of the 39 positive samples had a maximum antibody titre of 784 IU/ml. The prevalence rate varied tremendously between the samples from the townships and those from the welfare organisations. The prevalence rate of seropositive animals in PE ranged between 5% and 16% in the study area. No positive cases were found in KwaMagxaki and the Animal Welfare Society of PE, but both were surrounded by areas that had positive cases of Brucella canis infection.
The female dogs in the study area had a higher sero-prevalence of only 0.0169 (95% CI, 0.0631 to 0.1489) differences in proportion, and were thus not significant (p > 0.05). However, the female spayed dogs had a much higher significant difference of 0.1898 (95%
iv
CI, 0.1058 to 0.2738) in proportion to the male neutered dogs and were thus statistically significant (p < 0.05). Despite those results, out of all the dogs positive for Brucella canis only two were neutered males and five were spayed females, and the rest were all intact.
In conclusion, according to the results, Brucella canis antibodies were detected in sera of dogs mostly from the townships surveyed. Preventive measures against this contagion should be taken into consideration to eliminate Brucella canis infection from the entire dog population. Reservoir dogs and actively infected dogs either should be kept in quarantine or should be euthanized, because not only can they spread the disease and end the reproductive life of any breeding animal, but they are also a risk to human health.
Even though this is the first survey conducted in the Eastern Cape, the results are still high
dogs in the study area had a higher sero-prevalence of only 0.0169 (95% CI, 0.0631 to 0.1489) differences in proportion, and were thus not significant (p > 0.05). However, the female spayed dogs had a much higher significant difference of 0.1898 (95%
iv
CI, 0.1058 to 0.2738) in proportion to the male neutered dogs and were thus statistically significant (p < 0.05). Despite those results, out of all the dogs positive for Brucella canis only two were neutered males and five were spayed females, and the rest were all intact.
In conclusion, according to the results, Brucella canis antibodies were detected in sera of dogs mostly from the townships surveyed. Preventive measures against this contagion should be taken into consideration to eliminate Brucella canis infection from the entire dog population. Reservoir dogs and actively infected dogs either should be kept in quarantine or should be euthanized, because not only can they spread the disease and end the reproductive life of any breeding animal, but they are also a risk to human health.
Even though this is the first survey conducted in the Eastern Cape, the results are still high / College of Agriculture and Environmental Sciences / M. Sc. (Agriculture)
|
68 |
Avaliação da influência da temperatura e da precipitação na ocorrência da ferrugem asiática da soja por meio da técnica de árvore de decisão / Evaluation of the influence of temperature and precipitation in the occurrence of Asian soybean rust by using the technique of decision treeMegeto, Guilherme Augusto Silva, 1984- 07 October 2012 (has links)
Orientadores: Stanley Robson de Medeiros Oliveira, Carlos Alberto Alves Meira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-20T23:34:35Z (GMT). No. of bitstreams: 1
Megeto_GuilhermeAugustoSilva_M.pdf: 5556599 bytes, checksum: c545e13e7ec81e96cf9e6a3e46d01de2 (MD5)
Previous issue date: 2012 / Resumo: A ferrugem asiática, causada pelo fungo Phakopsora pachyrhizi, atualmente é considerada uma das doenças mais importantes e agressivas da soja. A principal forma de controle é a aplicação calendarizada de fungicidas a qual desconsidera o risco de ocorrência da doença. Estudos epidemiológicos buscam compreender os fatores que influenciam na ocorrência e desenvolvimento das epidemias, especialmente aqueles relacionados ao ambiente tais como condições meteorológicas. Com o avanço da tecnologia da informação e do armazenamento de dados, técnicas de mineração de dados (data mining) apresentam-se promissoras para a descoberta de conhecimento em bases de dados epidemiológicos. Este trabalho tem como objetivo avaliar a influência da chuva e da temperatura na ocorrência da ferrugem asiática da soja utilizando árvores de decisão. Para tal, foram obtidos dados de ocorrências da doença em quatro safras, de 2007/2008 a 2010/2011, oriundos do banco de dados do Consórcio Antiferrugem, e dados meteorológicos, provenientes do sistema Agritempo. A análise exploratória dos dados permitiu obter subsídios para compor o conjunto de dados final e definir o escopo deste trabalho, buscando-se características intrínsecas à doença e sua interação com o ambiente, utilizando apenas variáveis de base meteorológica. As variáveis utilizadas foram relacionadas à precipitação e à temperatura, que deram origem a nove atributos avaliados para cada período temporal...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: The Asian soybean rust, caused by Phakopsora pachyrhizi, is now considered one of the most important and aggressive diseases of soybean. The main form of control is the scheduled application of fungicides which disregards the the risk of disease occurrence. Epidemiological studies seek to understand the factors that influence the occurrence and development of epidemics, especially those related to the environment such as weather conditions. With the development of information technology and data warehousing, data mining techniques appear to be promising for knowledge discovery in epidemiological databases. This study aims to evaluate the influence of rainfall and temperature on the occurrence of soybean rust by using decision trees models. To accomplish that, data of the occurence of the disease were collected from four seasons, 2007/2008 to 2010/2011, from the Consórcio Antiferrugem and weather data from the Agritempo system. Exploratory data analysis allowed for obtaining subsidies to generate the final data set and define the scope of this work, seeking intrinsic characteristics of the disease and its interaction with the environment, using only meteorological variables. The variables used were related to precipitation and temperature, resulting into nine attributes evaluated in different periods. Such attributes were related to the event of occurrence (Oc) and non occurrence (NaoOc) of the disease (assumed as the thirtieth day prior to the event of occurrence). The results include a predictive model and an interpretive model for classifying events of occurrences and non occurrences of the disease...Note: The complete abstract is available with the full electronic document / Mestrado / Planejamento e Desenvolvimento Rural Sustentável / Mestre em Engenharia Agrícola
|
69 |
The epidemiology of work-related musculoskeletal disorders in beauty therapists working within the hotel spa industry in the eThekwini municipalityJacquire, Jolene January 2017 (has links)
Submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Department of Chiropractic and Somatology, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa. 2017. / Background
The growing popularity and competitive nature of the beauty industry has resulted in beauty therapists performing an extensive range of treatments to meet the demand, often at the jeopardy of their own well-being. Treatments include massage, waxing, pedicures and facials. These techniques involve vigorous and repetitive movements that may lead to overuse and strain on the musculoskeletal system, resulting in injury. Work-related activities together with factors such as socio-demographic, psychosocial, environmental and anthropometric can influence the prevalence of work-related musculoskeletal disorders (WRMDs). There has been little investigation into the WRMDs of beauty therapists both locally and internationally.
Aim
The aim of this study was to determine the prevalence, selected risk factors and impact of self-reported work related musculoskeletal disorders (WRMDs) in beauty therapists working within the hotel spa industry in the eThekwini municipality.
Method
A cross sectional epidemiological design was used to survey 254 beauty therapists working in the hotel spa industry in the eThekwini municipality of Durban. A pre-validated questionnaire was hand delivered to beauty therapists working at all hotel spas that agreed to participate. Informed consent was obtained. The survey contained questions related to musculoskeletal pain, socio-demographic, psycho-social, lifestyle and occupational factors.
Results
A response rate of 70% was obtained (n=178). The majority of the respondents were female (94.3%; n=165), the mean age of the respondents was 27.74 (SD±4.83) years. The respondents had been working as beauty therapists for an average of 5.91 (SD±4.19; n=176) years and performed on average 27.89 (SD±13.33; n=170) treatments per week, working 47.38 (SD±13.36; n=175) hours per week. Those working overtime worked on average 5.43 (SD±2.94; n=59) hours of overtime per week. There was a high rate of reported WRMDs with the lifetime, current and 12 month period prevalence being 86% (n=153), 85% (n=151) and 83% (n=148), respectively. The area most affected were the low back followed by the neck, the hand and wrist. Ninety percent of the respondents indicated that their pain was mild to moderate in nature, with half expressing an inability to cope with the pain, and 78% reporting that it interfered with their ability to work.
Mental exhaustion (p=0.032), suffering from a concomitant co-morbidity (p=0.031), years worked as a beauty therapist (p˂0.001) and treating clients after hours (p=0.007) were significantly associated with the presence of musculoskeletal pain. Performing manual massage (p=0.043) and reporting feelings of exhaustion whilst performing specialised massage techniques (p=0.014) and applying makeup/eyelashes (p=0.022) were associated with the presence of WRMDs. Those who reported having co-worker (p=0.006) and managerial support (p˂0.001) were less likely to experience musculoskeletal pain. In contrast, feeling frustrated by work (p=0.007), being under pressure (p=0.005) and over worked (p=0.009) increased the chances of experiencing WRMDs. Working with the back in an awkward position (p˂0.001), standing for prolonged periods (p˂0.001), lifting heavy loads (p=0.019) and working in a hot and humid environment (p<0.001) increased the risk of WRMDs.
Conclusion
WRMDs have a significant impact on beauty therapists’ ability to work. Effective strategies to prevent and manage WRMDs in hotel spa beauty therapists is required, along with governmental regulation. / M
|
70 |
Modeling and causal inference methods for analyzing and transporting an environmental mixture effectMayer, Melanie Nicole January 2024 (has links)
An environmental mixture is composed of multiple environmental exposures. Quantifying this joint effect on health outcomes mirrors what occurs in nature, offering significant benefits to environmental epidemiological research. However, analyzing the impact of an environmental mixture poses numerous statistical and inferential challenges. Motivated by the Strong Heart Study (SHS), a prospective cohort study of cardiovascular disease (CVD) outcomes among three American Indian communities where urine samples were collected at three visits and analyzed for concentrations of various metal exposures, this dissertation aims to improve our ability to analyze the effect of multiple, continuous, and correlated exposures with complex relationships on a health outcome using observational study data, such as the metal mixture exposure in the SHS. The contributions of this dissertation address two challenges inherent in environmental mixture analyses: modeling methods and the transportability of estimated effects.
In the first project presented in this dissertation, our goal was to evaluate the performance of available modeling methods for estimating the impact of an environmental mixture on survival outcomes. While survival time outcomes (also known as time-to-event outcomes) are very common in epidemiological studies, little attention has been given to examining the performance of existing modeling methods when estimating the effect of an environmental mixture on a survival outcome. In this chapter, we identified applicable and readily available modeling methods, assessed their performance through simulations replicating various real-world scenarios, and applied the selected methods to estimate the effect of a metal mixture on CVD incidence in the SHS. We examined proportional hazards (PH) based models as well as more flexible, machine learning-style models. Our simulations found that, when the PH assumption held, the effect estimates via flexible models had higher bias and variance compared to PH methods. However, when the PH assumption was violated, this discrepancy between the methods decreased and the more flexible methods achieved higher coverage. These simulation findings underscore the importance of demonstrating the robustness of findings across various modeling approaches in environmental epidemiology. In the SHS analysis, all methods found a significant, harmful effect of the metal mixture on incident CVD. However, the more flexible approaches found larger point estimates with wider confidence bands.
The second and third projects of this dissertation focus on constructing a framework for transporting an environmental mixture effect across populations. Numerous methods exist for analyzing environmental mixture effects within a population where sample data is available for. However, being able to adjust these effects based on the exposure/covariate distribution of a different target population would enable more precise estimation of the mixture effect in that population. This, in turn, allows for more accurate estimation of effects for populations distinct from those sampled. This broadens available data sources and provides significant advantages to researchers and policymakers interested in specific populations.
The second project leverages causal inference concepts to formally extend the transportability literature to the environmental mixtures context. We defined a relevant intervention with favorable properties concerning the exposure concentration positivity assumption and explicitly outline the assumptions needed to transport its effect across two observational studies. To assess whether the target population is well represented in the study population sample, which is required for the positivity of population membership assumption, a matching algorithm is proposed. Subject's environmental mixture exposure profiles are incorporated into subject matching on exposures and covariates between the two populations. Simulation results demonstrate that the matching algorithm effectively detects non-overlap across populations, with well-overlapped populations yielding minimally biased transported effect estimates, while those with insufficient overlap exhibit greater bias. Applying this framework, we estimated the effects of a metal mixture on coronary artery calcification (CAC) in the SHS cohort by transporting the effects observed in the Multi-Ethnic Study of Atherosclerosis (MESA). Although CAC was not directly measured in the SHS, its importance as a subclinical indicator of advanced atherosclerosis and its link to elevated cardiovascular risk underscore the significance of exploring its relationship with metal exposures in the SHS. Despite larger effects observed in the MESA population, significant effects persisted within the SHS, providing insights for innovative strategies in preventing and treating atherosclerosis progression among American Indian populations.
In the third project, we turned our focus to violations of internal and external validity exchangeability assumptions. We proposed the use of a negative control exposure analysis modeled with Bayesian Kernel Machine Regression with hierarchical variable selection to identify unmeasured confounding in the context of multiple, continuous, and correlated exposures when exposures are measured at various time points. Additionally, we developed a novel method for detecting violations of transportability assumptions by assessing the transportability of an effect within a study population. If the internal validity assumptions are plausible, then the inability to transport an effect within a study population suggests the presence of unmeasured effect modification in the study sample. Through simulations, we demonstrated the efficacy of these methods in detecting unmeasured confounding and effect modification. We applied these methods to assess the robustness of the estimated effect of a metal mixture on fasting blood glucose levels in the SHS to violations of transportability assumptions and found evidence of both unmeasured confounding and effect modification. However, the internal effect estimate remained significant and robust to unmeasured confounding.
|
Page generated in 0.0458 seconds