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Balancing efficiencies and tradeoffs in epidemiological field studies : evaluating EMG exposure assessment for low back injury risk factors in heavy industryTrask, Catherine Mary 11 1900 (has links)
In order to investigate the etiology of and evaluate interventions for work-related back injuries, researchers need efficient, accurate occupational exposure assessment methods suitable for large samples. The chapters in this thesis examine critical decisions using electromyography (EMG): How should exposure be measured? For what duration? Who should be measured, and how many times?
Low-back EMG, or muscle activity data, was collected during 138 full-shift field measurements over 30 different job titles at 50 different worksites in 5 heavy industries: forestry, transportation, wood products, construction, and warehousing. Observations and self-reports of posture, manual materials handling (MMH), and driving exposures were collected concurrently.
1) Variability of EMG calibration measurements was investigated on right/left sides, multiple trials, 4 positions, and pre/post-shift. Position accounts for the majority of explained variability; there is little to gain by measuring multiple trials or pre- and post-shift, but measuring both sides and multiple positions is worthwhile.
2) Observation and self-report data were easier to collect and cheaper than the EMG direct measure. Costs and successful field performance need to be weighed against the added data detail when making choices about exposure assessment techniques for epidemiological studies.
3) Observed and self-reported exposures were used to predict EMG exposure metrics using mixed multiple linear regression models. Regression models using observed variables predicted 43-50% of the variability in the EMG metrics, while self-reported variables predicted 21%-36%. The observation exposure model provides a low-cost alternative to direct measurement. The self-reported exposure model should be considered with more caution.
4) Full-shift EMG data was resampled for 4, 2, and 1 hour, and for 10 and 2 minute durations to determine the optimal sampling duration. Bias was consistently low, but shorter durations had higher absolute error, percentage error, and limits of agreement. Durations of 4 and 2 hours may be acceptable but those less than 1 hour had large errors.
5) Components of EMG variance were calculated between- and within-subject, and between- industry, company, job, and post hoc grouping. Resolution, contrast, and exposure-response relationship attenuation were calculated for each grouping scheme. The post hoc scheme had the highest contrast and lowest resolution.
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Racial differences in willingness to participate in HIV prevention clinical trials amongst university students in KwaZulu-Natal, South Africa.Pillay, Diantha. January 2013 (has links)
Introduction
Willingness to participate in clinical trials is a crucial element in recruitment of
suitable participants for intervention trials. Measurement of willingness to
participate assists in determining community preparedness for clinical trials,
such as HIV vaccine trials. Therefore, researchers have developed a Clinical
Research Involvement Scale (CRIS) to assess willingness to participate
modelled on the Theory of Reasoned Action. The CRIS was tested in the USA
and was noted that it would benefit from additional testing in other populations.
Aim
The purpose of this study is to determine whether racial differences exist in
willingness to participate and explore potential factors associated with
willingness to participate in HIV prevention research.
Methods
A cross sectional analytic study was conducted. The CRIS was administered to
university students aged 18-45 at the University of KwaZulu-Natal in South
Africa. The CRIS was administered online with a demographic questionnaire to
facilitate evaluation of possible associations between willingness to participate
and age, gender, relationship status, parity, religion, education status, student
status, employment status and access to private health care. Participation was
once-off at the time of completing the scale.
Results
The study enrolled 636 participants, two thirds being female. An effective
sample size of 509 was considered for analysis after data was cleaned for
accuracy and completeness. The results indicated that all students across all
race groups were willing to participate in HIV prevention research. However,
when considering factors that affected willingness to participate, statistically
significant differences were noted. Based on the differences amongst these
factors, Black students expressed greater intention to participate compared to
White and Indian students. The CRIS was deemed a reliable instrument in this
population; however in its current structure it did not show strong validity.
Validity improved if the factors of motivation to comply and outcome evaluations
were removed in this population.
Discussion
The study findings are specific to students of the University of KwaZulu-Natal
and cannot be generalized to other populations. The racial differences in factors
that affect willingness to participate indicate differences in risk perception and
seeking access to better quality healthcare.
Recommendations
The CRIS should be used in other student populations to assess its validity.
(350 words) / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Durban, 2013.
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Balancing efficiencies and tradeoffs in epidemiological field studies : evaluating EMG exposure assessment for low back injury risk factors in heavy industryTrask, Catherine Mary 11 1900 (has links)
In order to investigate the etiology of and evaluate interventions for work-related back injuries, researchers need efficient, accurate occupational exposure assessment methods suitable for large samples. The chapters in this thesis examine critical decisions using electromyography (EMG): How should exposure be measured? For what duration? Who should be measured, and how many times?
Low-back EMG, or muscle activity data, was collected during 138 full-shift field measurements over 30 different job titles at 50 different worksites in 5 heavy industries: forestry, transportation, wood products, construction, and warehousing. Observations and self-reports of posture, manual materials handling (MMH), and driving exposures were collected concurrently.
1) Variability of EMG calibration measurements was investigated on right/left sides, multiple trials, 4 positions, and pre/post-shift. Position accounts for the majority of explained variability; there is little to gain by measuring multiple trials or pre- and post-shift, but measuring both sides and multiple positions is worthwhile.
2) Observation and self-report data were easier to collect and cheaper than the EMG direct measure. Costs and successful field performance need to be weighed against the added data detail when making choices about exposure assessment techniques for epidemiological studies.
3) Observed and self-reported exposures were used to predict EMG exposure metrics using mixed multiple linear regression models. Regression models using observed variables predicted 43-50% of the variability in the EMG metrics, while self-reported variables predicted 21%-36%. The observation exposure model provides a low-cost alternative to direct measurement. The self-reported exposure model should be considered with more caution.
4) Full-shift EMG data was resampled for 4, 2, and 1 hour, and for 10 and 2 minute durations to determine the optimal sampling duration. Bias was consistently low, but shorter durations had higher absolute error, percentage error, and limits of agreement. Durations of 4 and 2 hours may be acceptable but those less than 1 hour had large errors.
5) Components of EMG variance were calculated between- and within-subject, and between- industry, company, job, and post hoc grouping. Resolution, contrast, and exposure-response relationship attenuation were calculated for each grouping scheme. The post hoc scheme had the highest contrast and lowest resolution.
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Varying-coefficient models for longitudinal data : piecewise-continuous, flexible, mixed-effects models and methods for analyzing data with nonignorable dropout /Forster, Jeri E. January 2006 (has links)
Thesis (Ph.D. in Biostatistics) -- University of Colorado at Denver and Health Sciences Center, 2006. / Typescript. Includes bibliographical references (leaves 72-75). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;
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Models for serially correlated, over or underdispersed, unequally spaced longitudinal count data with applications to asthma inhaler use /Bruce, Stephanie L. January 2007 (has links)
Thesis (Ph.D. in Analytic Health Sciences, Dept. of Preventive Medicine and Biometrics) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 57-59). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;
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Estimativa da ceratometria média a partir dos dados biométricos e refração pós-operatórios de olhos de crianças submetidas à facectomia por catarata congênita e do desenvolvimento / Estimation of mean keratometry from biometric data and postoperative eye refraction of children with congenital and developmental cataract submitted to cataract surgeryFachinelli, Rodolfo de Lima 22 February 2018 (has links)
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Previous issue date: 2018-02-22 / Objetivo: Comparar a ceratometria média aferida (KA) sob narcose em crianças submetidas à facectomia, por catarata congênita ou do desenvolvimento, com a ceratometria média obtida por cálculo teórico (KC), utilizando o poder dióptrico da lente intraocular (LIO) implantada e dados refracionais e biométricos pós-operatórios, a fim de evidenciar possíveis erros de aferição da KA devido a narcose. Métodos: Estudo retrospectivo realizado a partir da análise de dados coletados de prontuários de pacientes com catarata bilateral, congênita ou do desenvolvimento, que receberam tratamento cirúrgico no HC-FMB. Foram analisados 73 olhos de crianças que possuíam pelo menos um exame pós-operatório completo, cada momento em que determinado olho foi examinado foi considerado um elemento do conjunto amostral, totalizando 165 momentos. KC foi obtida a partir de fórmula teórica para cálculo de LIO, utilizando os dados biométricos pós-operatórios (AL e ACD), refratometria automatizada pós-operatória e poder dióptrico da LIO implantada. Foi calculada a diferença entre KA e KC (Desvio = KA – KC). Para análise estatística dos desvios encontrados e comparação entre KA e KC, foi realizado o teste de associação de Goodman e o teste não paramétrico de Kruskal-Wallis. Resultados: A média de idade no momento da cirurgia do primeiro olho foi 954,62 dias, com desvio padrão de ±794,14 dias, mediana de 953 dias, sendo a idade mínima de 44 dias e a máxima de 2659 dias. Vinte e três eram do sexo masculino (62,16%) e 14 eram do sexo feminino (37,84%). KA variou de 40,62D a 51,50D, com mediana de 45,25D, média de 45,32D e desvio padrão de ±2,37D. KC variou de 39,40D a 52,26D, com mediana de 44,49D, média de 44,54D e desvio padrão de ±2,41D. Os desvios (Desvio = KA – KC) variaram de -2,28D a 3,81D, com mediana de 0,83D, média de 0,79D e desvio padrão de ±1,18D. A relação entre KC e KA pode ser representada pela equação KA = 1,0172 Kc. Conclusão: A comparação entre KC e KA em crianças sob narcose evidenciou que há superestimação do valor aferido em relação ao calculado. A análise dos desvios encontrados mostrou tendência para maior superestimação quanto maior a KA com diferença significativa (p<0,05) nas aferições acima de 44,0D. / Purpose: To compare the mean keratometry measured (KA) in children under anesthesia to receive surgical treatment for congenital or developmental cataract with a mean keratometry obtaeined by a theoretical formula (KC), using the implanted intraocular lens (IOL) power value and postoperative refractional and biometric data, in order to check possible observational erros of KA due to general anesthesia. Methods: A retrospective study analysing records of patients with congenital or developmental bilateral cataract who underwent surgical treatment at HC-FMB. Seventy-three children’s eyes that had at least one full postoperative exam were analyzed, each time one eye was assessed was considered one element of the sample group, and the total amount was 165 elements. KC was determined by a theoretical formula for calculating IOL power using postoperative biometric data (AL e ACD), postoperative automatic refractometery and refractive power of the implanted IOL. The KA observational error value was obtained by subtracting KC from KA (Error = KA - KC). Statistical analysis of the observational erros and the comparison between KA and KC were made by Goodman’s test and Kruskal-Wallis’ non-parametric test. Results: the mean age at the moment of the first surgery was of 954,62 days, the standard deviation was ±794,14 days, the median was 953 days, the minimum age was 44 days and the maximum age was 2659 days. Twenty-three (62,16%) patients were male and 14 (37,84%) female. KA ranged from 40,62D to 51,50D, the median was 45,25D, the mean was 45,32D and the standard deviation was ±2,37D. KC ranged from 39,40D to 52,26D, the median was 44,49D, the mean was 44,54D and the standard deviation was ±2,41D. Observational errors ranged from -2,28D to 3,81D, the median was 0,83D, the mean was 0,79D and the standard deviation was ±1,18D. The rate between KC and KA can be represented by the equation KA = 1.0172 KC. Conclusion: The comparison between KC and KA in children under general anesthesia showed that there is an overestimation of the value measured when compared to the calculated one. The analysis of the observational errors showed there is a tendency to greater overestimation the higher the KA, with significant difference (p <0.05) in the measurements over 44.0D.
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Estimativa da ceratometria média a partir dos dados biométricos e refração pós-operatórios de olhos de crianças submetidas à facectomia por catarata congênita e do desenvolvimentoFachinelli, Rodolfo de Lima January 2018 (has links)
Orientador: Antonio Carlos Lottelli Rodrigues / Resumo: Objetivo: Comparar a ceratometria média aferida (KA) sob narcose em crianças submetidas à facectomia, por catarata congênita ou do desenvolvimento, com a ceratometria média obtida por cálculo teórico (KC), utilizando o poder dióptrico da lente intraocular (LIO) implantada e dados refracionais e biométricos pós-operatórios, a fim de evidenciar possíveis erros de aferição da KA devido a narcose. Métodos: Estudo retrospectivo realizado a partir da análise de dados coletados de prontuários de pacientes com catarata bilateral, congênita ou do desenvolvimento, que receberam tratamento cirúrgico no HC-FMB. Foram analisados 73 olhos de crianças que possuíam pelo menos um exame pós-operatório completo, cada momento em que determinado olho foi examinado foi considerado um elemento do conjunto amostral, totalizando 165 momentos. KC foi obtida a partir de fórmula teórica para cálculo de LIO, utilizando os dados biométricos pós-operatórios (AL e ACD), refratometria automatizada pós-operatória e poder dióptrico da LIO implantada. Foi calculada a diferença entre KA e KC (Desvio = KA – KC). Para análise estatística dos desvios encontrados e comparação entre KA e KC, foi realizado o teste de associação de Goodman e o teste não paramétrico de Kruskal-Wallis. Resultados: A média de idade no momento da cirurgia do primeiro olho foi 954,62 dias, com desvio padrão de ±794,14 dias, mediana de 953 dias, sendo a idade mínima de 44 dias e a máxima de 2659 dias. Vinte e três eram do sexo masculino (62,... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Purpose: To compare the mean keratometry measured (KA) in children under anesthesia to receive surgical treatment for congenital or developmental cataract with a mean keratometry obtaeined by a theoretical formula (KC), using the implanted intraocular lens (IOL) power value and postoperative refractional and biometric data, in order to check possible observational erros of KA due to general anesthesia. Methods: A retrospective study analysing records of patients with congenital or developmental bilateral cataract who underwent surgical treatment at HC-FMB. Seventy-three children’s eyes that had at least one full postoperative exam were analyzed, each time one eye was assessed was considered one element of the sample group, and the total amount was 165 elements. KC was determined by a theoretical formula for calculating IOL power using postoperative biometric data (AL e ACD), postoperative automatic refractometery and refractive power of the implanted IOL. The KA observational error value was obtained by subtracting KC from KA (Error = KA - KC). Statistical analysis of the observational erros and the comparison between KA and KC were made by Goodman’s test and Kruskal-Wallis’ non-parametric test. Results: the mean age at the moment of the first surgery was of 954,62 days, the standard deviation was ±794,14 days, the median was 953 days, the minimum age was 44 days and the maximum age was 2659 days. Twenty-three (62,16%) patients were male and 14 (37,84%) female. KA ranged from... (Complete abstract click electronic access below) / Mestre
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Avaliação dos métodos biométricos do olho humano empregados no cálculo do poder dióptrico da lente intra-ocular / Evaluation of the biometric methods used for the human eye axial measurements on intraocular lens calculationOliveira, Filipe de [UNIFESP] 27 January 2010 (has links) (PDF)
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Previous issue date: 2010-01-27 / Objetivo: Avaliar os métodos biométricos do olho humano em pacientes portadores de catarata e com indicação de implante de lente intra-ocular. Métodos: Oitenta e quatro pacientes com média de idade de 58,82 ± 10,03 anos foram submetidos às biometrias óptica e ultra-sônica (imersão e contato) em ambos os olhos (n = 168). Os dados do comprimento axial, profundidade da câmara anterior, espessura do cristalino, profundidade da câmara vítrea e curvatura da córnea foram analisados. Foi avaliada a diferença das médias de cada método biométrico usado e a concordância foi investigada pela análise gráfica intra-individual de Bland-Altman de um método em relação ao outro. Resultados: Não houve diferença estatisticamente significante para as médias do comprimento axial (P=0,245), profundidade da câmara anterior (P=0,073), espessura do cristalino (P=0,8794) e profundidade da câmara vítrea (P=0,7640) entre os métodos usados. A diferença das médias da curvatura da córnea entre o IOLMaster® e o ceratômetro manual OM-4® foi estatisticamente significante (P<0,0001). Apesar da boa reprodutibilidade dos resultados, os gráficos de Bland- Altman mostraram algumas medidas fora dos limites de concordância estabelecidos em todas as variáveis analisadas. Houve menor concordância das medidas ceratométricas na comparação entre o IOLMaster® e o ceratômetro OM- 4®. Conclusões: Não houve diferença das médias dos métodos biométricos usados nesse estudo, exceto a curvatura da córnea que apresentou uma diferença estatisticamente significante entre as médias apresentadas. Os métodos demonstraram boa concordância, entretanto algumas medidas se apresentaram discordantes e podem ocasionar erros no cálculo do poder dióptrico da lente intraocular. / TEDE / BV UNIFESP: Teses e dissertações
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Comparação dos valores da pressão intraocular obtidos com diferentes tonômetros e suas correlações com dados biométricos oculares no glaucoma congênito / Comparison between intraocular pressure obtained with different tonometers and their correlations with biometric parameters in congenital glaucomaMarcio Henrique Mendes 01 November 2013 (has links)
OBJETIVOS: Comparar os valores da pressão intraocular (PIO), obtidos por intermédio do tonômetro de Perkins (TPK), tonômetro de contorno dinâmico Pascal (TCD) e Tono-Pen (TNP), confrontando-os com o tonômetro de aplanação de Goldmann (TAG), e correlacionar seus valores tonométricos com parâmetros biométricos oculares em pacientes portadores de glaucoma congênito primário. MÉTODOS: Estudo prospectivo, transversal, com inclusão de 46 pacientes (46 olhos) com diagnóstico de glaucoma congênito primário, com idades entre 12 e 40 anos, após obtenção do Termo de Consentimento Livre e Esclarecido. Todos os olhos estudados foram submetidos à tonometria ocular usando os tonômetros de Goldmann, de Perkins, o Tono-Pen e o tonômetro de contorno dinâmico Pascal. A ordem das tonometrias foi aleatória e o tonômetro de Goldmann foi adotado como padrão ouro. Os parâmetros biométricos estudados foram a curvatura (medida pela ceratometria), a espessura central da córnea (paquimetria), o diâmetro corneal (medido por meio de compasso cirúrgico) e o comprimento axial do olho foi obtido pela biometria ultrassônica. As distribuições dos parâmetros biométricos, assim como das tonometrias foram plotadas e analisadas conforme teste de Kolmogorov-Smirnov para aceitação de normalidade. O teste t de Student pareado para amostras independentes foi empregado para comparar as médias tonométricas de cada tonômetro com o padrão ouro. As correlações entre os parâmetros biométricos e as tonometrias foram realizadas através do coeficiente de correlação de Pearson e gráficos de regressão linear. O mesmo procedimento foi feito entre os parâmetros biométricos e as diferenças entre as três distintas tonometrias e a TAG. A concordância entre os tonômetros Perkins, Pascal e Tono-Pen e o de Goldamnn foi realizada pelo teste de concordância de correlação (CCC) e graficamente pelo método de Bland-Altman. O valor de corte de 2 mmHg foi adotado para avaliar a empregabilidade clínica desses tonômetros em pacientes semelhantes aos da amostra. RESULTADOS: O teste de Kolmogorov-Smirnov indicou aceitação da normalidade para todas as distribuições estudadas (TAG, TPK, TCD, TNP, Diâmetros corneal e axial, ceratometria média e paquimetria). Os momentos de correlação de Pearson empregados para realizar estudo das correlações entre os parâmetros biométricos e cada tonometria foram estatisticamente não significativos. As correlações entre os parâmetros biométricos e as diferenças entre tonometrias em relação ao TAG não apresentaram significância em sua maioria, sendo a única exceção a correlação moderada entre a diferença do TAG e o Tono-Pen versus a ceratometria média. No entanto, o coeficiente de determinação evidenciou influência modesta da ceratometria nessas diferenças (r² = 0,16; p = 0,004). O teste t de Student pareado demonstrou diferença significativa entre o TAG e o TP (p < 0,001). A diferença não foi significativa entre o TAG e o Pascal (p = 0.30), ou entre o TAG e o Tono-Pen (p = 0.68). Houve excelente concordância entre o TAG e o TP (CCC = 0,98; intervalo de confiança 95% (IC95%) = 0,97 - 0,99), já entre o TAG e o Pascal (CCC = 0,89; IC95% = 0,82 - 0,94) e entre o TAG e o Tono-Pen (CCC = 0,92; IC95% = 0,87 - 0,95). O gráfico tipo Bland-Altman TAG x Perkins demonstrou diferença média de 0,47 mmHg com intervalo de 95% (I95%) situado entre -0,98 e 1,92 mmHg. A dispersão das diferenças seguiu caráter aleatório. Os outros dois tonômetros também tiveram suas dispersões em caráter aleatório. TAG em relação ao tonômetro de Pascal apresentou diferença média de -0,3 mmHg (I95% = -4,2 a 3,6 mmHg). A diferença média do TAG em relação ao Tono-Pen foi de -0,1 mmHg (I95% = -3,7 a 3,5 mmHg). Em 21% dos pacientes, o tonômetro de Pascal apresentou diferenças maiores de 2 mmHg em relação ao TAG, ao passo que no Tono- Pen essa proporção foi de 17,3%, e o tonômetro de Perkins não apresentou em nenhum dos pacientes diferenças maiores que estes limites. CONCLUSÕES: A ceratometria, paquimetria e os diâmetros axial e corneal não se correlacionaram com a PIO obtida por meio do TAG, tonômetro de Perkins, Pascal ou Tono-Pen. As diferenças tonométricas entre TAG (padrão ouro) e os outros tonômetros também não se correlacionaram com esses parâmetros biométricos, com exceção da ceratometria média, que se correlacionou positiva e moderadamente com a diferença da PIO entre TAG e Tono-Pen. O tonômetro de Perkins apresentou concordância substancial com o TAG, já o Tono-Pen e o TCD apresentaram concordâncias moderadas, sendo a concordância do Tono-Pen maior que a do TCD / OBJECTIVES: To compare the values of intraocular pressure (IOP) obtained by Perkins tonometer (PKT), Pascal dynamic contour tonometer (DCT) and Tono-Pen (TP), comparing then with Goldmann applanation tonometry (GAT), analyzing their correlations with ocular biometric parameters in patients with primary congenital glaucoma. METHODS: Prospective and cross-sectional study, including 46 patients (46 eyes) diagnosed with primary congenital glaucoma, between 12 and 40 years old, after obtaining informed consent. Keratometry was performed, followed by Goldmann applanation tonometry, Perkins tonometry, DCT and TP. The order of tonometries was randomized. The Goldmann tonometer was adopted as the gold standard. Ultrasound pachymetry, ultrasound biometry and corneal diameter measurement with surgical compass were also performed. The distributions of biometric parameters, as well as the tonometries were plotted and analyzed using Kolmogorov-Smirnov for acceptance of normality. Paired Student\'s t test for independent samples was used to compare the means of each tonometry with the gold standard. The correlations between biometric parameters and tonometries were performed by Pearson\'s product moment correlation coefficient and linear regression plots. The same procedure was done between biometric parameters and the differences between the three distinct tonometries and Goldmann tonometry. The agreement between tonometers and the GAT was performed through concordance correlation coefficient (CCC) and graphically by the Bland-Altman method. End point of 2 mmHg was adopted to evaluate clinical employability of these tonometers in patients with similar conditions. RESULTS: The Kolmogorov-Smirnov indicated acceptance of normality for all distributions studied (GAT, PKT, DCT, TP, corneal diameter, axial length, keratometry and pachymetry). All the Pearson´s product moment correlation coefficients between biometric parameters and each tonometry were not significant. The correlations between the biometric parameters and the differences between tonometries compared to the gold standard were not significant in most cases. The only exception was a positive and moderate correlation between the difference of the GAT and Tono-Pen versus the keratometry. The determintation coefficient revealed a considerable, but no large influence of K on the differences between GAT and Tono-Pen (r² = 0.16; p = 0.004). Student\'s paired t test showed a significant difference between GAT and PT (p < 0.001). The difference was not significant between the GAT and Pascal (p = 0.30), or between the GAT and Tono-Pen (p = 0.68). There was excellent agreement between GAT and PT (CCC = 0.98, 95% confidence interval (95% CI) = 0.97 to 0.99), as between GAT and Pascal (CCC = 0.90, 95% CI = 0.82 to 0.94) and between GAT and Tono-Pen (CCC = 0.92, 95% CI = .87 to .95). Bland-Altman plot GAT x Perkins showed a mean difference of 0, 47 mmHg with 95% CI located between -0.98 and 1.92 mmHg. The distribution of the IOP differences was aleatory. The other two differences` distributions also had aleatory characteristics. When comparing GAT with Pascal, the mean difference was -0.3 mmHg (95% CI = -4.2% to 3.6 mmHg). Mean difference between GAT and Tono-Pen was -0.1 mmHg (95% CI = -3,7 to 3.5 mmHg). Pascal tonometer showed a difference greater than 2 mmHg comparing to GAT in 21% of the patients, while with Tono-Pen this ratio was 17.3% and the Perkins tonometer did not present in any patient differences greater than these limits. CONCLUSIONS: The keratometry, pachymetry, corneal diameter and axial length did not correlate with IOP obtained by GAT, Perkins tonometer, Tono-Pen or Pascal. The differences between GAT (gold standard) and the other tonometers also did not correlate with these biometric parameters, with the exception of corneal curvature, which was positive and moderately correlated with the difference in IOP between GAT and Tono-Pen. GAT and Perkins tonometer showed substantial agreement, although Tono-Pen and DCT showed moderate agreement with GAT. The concordance obtained with Tono-Pen was higher than the concordance obtained with DCT
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Características tecnológicas de espécies de pescado com potencial de criação na região sudoeste do Paraná / Technological characteristics of fish species with creating potential in Paraná southwest regionNogueira, Barbara Arruda 21 March 2016 (has links)
CNPq; CAPES / A carne de pescado possui composição química particular que lhe confere elevado valor nutricional. Entretanto, esse alimento é identificado pela alta perecibilidade, aspecto esse muitas vezes apontado como barreira ao consumo de pescado. A região Sudoeste do Paraná, paralela à realidade do país, é caracterizada pelo baixo consumo de pescado; e uma das estratégias apontadas para o aumento do consumo dessa importante fonte proteica é o incentivo à produção de outras espécies além da tilápia. Dentro desse contexto, faz-se necessário o conhecimento a respeito das características da carne de pescado. Nesse sentido, o objetivo do presente trabalho foi avaliar o potencial tecnológico das espécies pacu, carpa capim e catfish. Em um primeiro momento realizou-se a avaliação química, frescor e biométrica, sob dois métodos estatísticos descritivos distintos, das três espécies; e avaliou-se a capacidade discriminante das variáveis em estudo. Em um segundo momento buscou-se avaliar os efeitos de dois processos distintos de lavagem (ácida e alcalina) no que diz respeito à remoção de nitrogenados e pigmentos e na capacidade emulsificante das proteínas da base proteica obtida. A terceira fase deste trabalho objetivou-se otimizar a metodologia em CG-EM para análise de compostos geosmina e MIB (2-metilisoborneol), compostos esses responsáveis pelo sabor/odor a terra e mofo em pescados de água doce. Os resultados revelaram altos teores de proteína e baixos teores de lipídios para as três espécies. A comparação entre médias e medianas revelaram simetria apenas para os valores de proteínas e medidas biométricas. Os lipídios quando avaliados apenas pelas médias superestimaram os teores para todas as espécies. Correlações entre medidas corporais e rendimento de filé apresentaram baixa relação, independente da espécie analisada, sendo a melhor equação de predição a que relaciona peso total e peso de filé. As variáveis biométricas foram as melhores discriminantes entre as espécies. Quanto à avaliação das lavagens, verificou-se que os processos ácido e básico foram igualmente (p ≥ 0,05) eficientes (p ≤ 0,05) na remoção dos compostos nitrogenados nas polpas de pescado. No que diz respeito à extração de pigmentos, eficiência de remoção foram registradas apenas para a espécie pacu, quando os dados foram avaliados pelos parâmetros L*, a*, b*. Quando avaliados pela diferença total de cor (ΔE) antes e após as lavagens, para ambos os processos (ácido/alcalino), os ΔE revelaram factível percepção a olho nu para todas as espécies. Catfish foi caracterizado como o pescado que apresenta a carne mais clara e a lavagem básica foi apontada como a mais eficiente para remoção de pigmentos para essa espécie. As bases proteicas obtidas pela lavagem alcalina apresentaram maior capacidade emulsificante (p ≤ 0,05) quando comparadas às polpas sem lavar e lavadas em processo ácido. A metodologia aplicada para quantificação de MIB e geosmina permitiu constatar que o método de extração e purificação dos analitos apresentou baixa recuperação e que estudos futuros devem ser desenvolvidos para identificação e quantificação de MIB e geosmina em amostras de pescado. / The fish meat has a particular chemical composition which gives its high nutritional value. However, this food is identified for being highly perishable and this aspect is often named as a barrier to fish consumption. The southwestern Paraná region, parallel to the country's reality, it is characterized by low fish consumption; and one of the strategies aimed at increasing the consumption of this important protein source is encouraging the production of other species besides tilapia. Within this context, it is necessary to know about the meat characteristics. In this sense, the objective of this study was to evaluate the technological potential of pacu, grass carp and catfish species. To do so, at first, it was discussed the chemical and biometric assessment under two distinct descriptive statistical methods, of the three species; and it was also evaluated the discriminating capacity of the study. In a second moment, an evaluation of effects done by two different processes of washing (acid and alkaline) regarding the removal of nitrogen compounds, pigments and the emulsifying ability of the proteins contained in the protein base obtained. Finally, in the third phase, it was aimed to realize the methodology optimization in GC-MS for the analysis geosmin and MIB (2-metilisoborneol) compounds that are responsible for taste/smell of soil and mold in freshwater fish. The results showed a high protein and low lipid content for the three species. The comparison between means and medians revealed symmetry only for protein values and biometric measurements. Lipids, when evaluated only by the means, overestimate the levels for all species. Correlations between body measurements and fillet yield had low correlation, regardless of the species analyzed, and the best prediction equation relates the total weight and fillet weight. The biometric variables were the best discriminating among the species. The evaluation of the washings, it was found that the acidic and basic processes were equally (p ≥ 0.05) efficient (p ≤ 0.05) for the removal of nitrogen compounds on the fish pulps. Regarding the extraction of pigments, a removal efficiency was recorded only for the pacu species, the data were assessed by the parameters L *, a *, b *. When evaluated by the total color difference (ΔE) before and after washing for both processes (acid/alkaline) the ΔE proved feasible perceived by naked eye for all species. The catfish was characterized as the fish that presents the clearest meat with the basic washing considered the most effective in removing pigments for this species. Protein bases obtained by alkaline washes have higher emulsifying capacity (p ≤ 0.05) when compared to unwashed and washed in acid process pulps. The methodology applied for the quantification of MIB and geosmin, allowed to establish that the method of extraction and purification of analytes had low recovery and future studies should be developed for identification and quantification of MIB and geosmin on fish samples.
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