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991.
The objective of this study was to develop a multifactor model of job, individual and psychosocial factors in prevalence of distal upper extremity musculoskeletal disorders (DUE MSDs); and quantify job physical exposure to establish safe exposure limits. The study sample comprised of 525 workers who were part of a large prospective cohort study and represented a broad array of industrial practices and a wide range of job physical exposure. Only baseline data was considered for the analysis in the study. Workers underwent laptop administered questionnaires, structured interviews, two standardized physical examinations and nerve conduction studies to ascertain demographic, medical history, psychosocial factors and current DUE MSDs. All workers' jobs were individually measured for job physical exposure factors and videotaped. Binomial logistic regression was used to develop and test the multifactor association and quantification of job physical exposure for safe exposure limits. Results indicated that work-related DUE MSDs are multifactor in nature and are significantly affected by specific factors of (1) job physical exposure - percentage duration of exertion (PDOE), workers' subjective ratings of perceived effort or intensity of exertion (IOE) (using Borg CR-10), hand activity level measured by the American conference of Governmental Industrial Hygienists (ACGIH) threshold limit value for hand activity level (TLV for HAL), and presence of 2-point pinch grasps; (2) individual factors - female gender, diabetes, higher body mass index (BMI), and past and current smokers; (3) psychosocial factors - neither likely/unlikely or very unlikely to take up the current job again, divorced/separated, and presence of family problems. Quantification of job physical exposure indicated that prevalence of work-related DUE MSDs significantly increases with efforts per minute (Eff/min) >8 (OR = 1.69, p = 0.006) and woker's perceived effort based on Borg rating for IOE at the end of the shift >3 (OR = 2.46, p < 0.001). Further studies should be conducted to validate these safe exposure limit criteria. 相似文献
992.
With higher levels of automation in modern manufacturing, there is increased monitoring of the process by the human operator. Prolonged monitoring or sustained attention has been found to be stressful for human operators. Plant and process operators have also been found to have one of the highest level of work demands (work speed, pace) in a recent European survey (Eurofound, 2015). Along with this, the incidence of Work Related Musculoskeletal Disorders (WRMSDs) remains at a high level in the manufacturing sector. This research endeavoured to determine if end-tidal CO2 levels decreased and upper trapezius muscle activity increased concurrently with increased levels of attention. We then developed a model to investigate if end-tidal CO2 moderated the relationship between mental workload due to sustained attention and upper trapezius muscle activity. The resulting interactional model found that end-tidal CO2 moderated the relationship (p = 0.004) when end-tidal CO2 reached the hypocapnic range (>35 mm Hg). This model indicates the possibility that a high level of sustained attention is a risk factor in the development of WRMSDs and should therefore be included in workplace risk assessments. 相似文献
993.
994.
为了解饥饿胁迫对鲤形体、鱼体生化成分及血液生理的影响,在18~22℃条件下对鲤进行了0 d、10 d、20 d、30d的饥饿试验。试验结果表明,随着鲤饥饿时间的延长,肥满度、肠体比、肝体比呈现下降趋势,但差异均不显著(P〉0.05);鲤肌肉中水分和粗灰分呈现升高的趋势,粗脂肪呈现下降的趋势,但差异均不显著(P〉0.05),粗蛋白呈现下降的趋势,差异显著(P〈0.05);血液中红细胞数量、血红蛋白值显著下降(P〈0.05),白细胞数量呈现上升的趋势,血糖含量先下降后稳定下来。说明短期饥饿胁迫使鲤形体发生一定改变、随着饥饿时间的延长,鲤首先动用肌肉中的脂肪,再动用蛋白质来维持体内的正常代谢,同时血液生理指标也发生与饥饿相适应的变化。 相似文献
995.
阐述服装压力对人体生理、运动防护及病人伤口恢复的影响.总结国内外服装压力测试方法的原理,并分析服装压力的数学模型及软体假人在压力测试方面的应用,指出服装压力测试方法的发展趋势. 相似文献
996.
997.
《Measurement》2016
In this article, a new data pre-processing method has been suggested to detect and classify vertebral column disorders and lumbar disc diseases with a high accuracy level. The suggested pre-processing method is called the Mean Shift Clustering-Based Attribute Weighting (MSCBAW) and is based primarily on mean shift clustering algorithm finding the number of the sets automatically. In this study, we have used two different datasets including lumbar disc diseases (with two classes-our database) and vertebral column disorders datasets (with two or three classes) taken from UCI (University of California at Irvine) machine learning database to test the proposed approach. The MSCBAW method is working as follows: first of all, the centres of the sets automatically for each characteristics in dataset by using the mean shift clustering algorithm are computed. And then, the mean values of each property in dataset are calculated. The weighted datasets by multiplying these mean values by each property value in the dataset that have been obtained by dividing the above mentioned mean values by the centres of the sets belonging to the relevant property are achieved. After the data weighting stage, three different classification algorithms that included the k-NN (k-Nearest Neighbour), RBF–NN (Radial Basis Function–Neural Network) and SVM (Support Vector Machine) classifying algorithms have been used to classify the datasets. In the classification of vertebral column disorders dataset with two classes (normal or abnormal), while the obtained classification accuracies and kappa values were 78.70% ± 0.455 (the classification accuracy ± standard deviation), 81.93% ± 0.899, and 80.32% ± 0.56 using SVM, k-NN (for k = 1), and RBF–NN classifiers, respectively, the combinations of MSCBAW and SVM, k-NN (for k = 1), and RBF–NN classifiers were obtained 99.03% ± 0.977, 99.67% ± 0.992, and 99.35% ± 0.9852, respectively. In the classification of second dataset named vertebral column disorders dataset with three classes (Normal, Disk Hernia, and Spondylolisthesis), while the obtained classification accuracies and kappa values were 74.51% ± 0.581, 78.70% ± 0.659, and 83.22% ± 0.728 using SVM, k-NN (for k = 1), and RBF–NN classifiers, respectively, the combinations of MSCBAW and SVM, k-NN (for k = 1), and RBF–NN classifiers were obtained 99.35% ± 0.989, 96.77% ± 0.948, and 99.67% ± 0.994, respectively. As for the lumbar disc dataset, while the obtained classification accuracies and kappa values were 94.54% ± 0.974, 94.54% ± 0.877, and 93.45% ± 0.856 using SVM, k-NN (for k = 1), and RBF–NN classifiers, respectively, the combinations of MSCBAW and SVM, k-NN (for k = 1), and RBF–NN classifiers were obtained 100% ± 1.00, 99.63% ± 0.991, and 99.63% ± 0.991, respectively. The best hybrid models in the classification of vertebral column disorders dataset with two classes, vertebral column disorders dataset with three classes, and lumbar disc dataset were the combination of MSCBAW and k-NN classifier, the combination of MSCBAW and RBF–NN classifier, and the combination of MSCBAW and SVM classifier, respectively. 相似文献
998.
Muhammad Balal Arain Tasneem Gul Kazi Jameel Ahmed Baig Muhammad Khan Jamali Hassan Imran Afridi Nusrat Jalbani Raja Adil Sarfraz Abdul Qadir Shah Ghulam Abbas Kandhro 《The Science of the total environment》2009,407(21):5524-5530
In this study, a survey has been conducted during 2005-2007 on surface and groundwater arsenic (As) contamination and its impact on the health of local population, of villages located on the banks of Manchar lake, southern part of Sindh, Pakistan. We have also assessed the relationship between arsenic exposure through respiratory disorders in male subjects with drinking water and smoking cigarettes made from tobacco grown in agricultural land irrigated with As contaminated lake water. The biological samples (blood and scalp hair) were collected from As exposed subjects (100% smokers) and age matched healthy male subjects (40.2% smoker and 59.8% non smokers) belong to unexposed areas for comparison purposes. The As concentration in drinking water (surface and underground water), agricultural soil, cigarette tobacco and biological samples were determined by electrothermal atomic absorption spectrometry. The range of As concentrations in lake water was 35.2-158 µg/L (average 97.5 µg/L), which is 3-15 folds higher than permissible limit of World Health Organization (WHO, 2004). While the As level in local cigarette tobacco was found to be 3-6 folds higher than branded cigarettes (0.37-0.79 µg/g). Arsenic exposed subjects (with and without RD) had significantly elevated levels of As in their biological samples as compared to referent male subject of unexposed area. These respiratory effects were more pronounced in individuals who had also As induced skin lesions. The linear regressions showed good correlations between As concentrations in water versus hair and blood samples of exposed subjects with and without respiratory problems. 相似文献
999.
This study investigated whether adjusting clothing to remain in neutral thermal comfort at moderately elevated temperature is capable of avoiding negative effects on perceived acute subclinical health symptoms, comfort, and cognitive performance. Two temperatures were examined: 23°C and 27°C. Twelve subjects were able to remain thermally comfortable at both temperatures by adjusting their clothing. They rated the physical environment, their comfort, the intensity of acute subclinical health symptoms, and their mental load, and they performed a number of cognitive tasks. Their physiological reactions were monitored. Their performance of several tasks was significantly worse at 27°C, and they reported increased mental load at this temperature. Skin temperature and humidity and respiration rate were higher, while blood oxygen saturation (SpO2) and pNN50 were lower at this temperature, the latter indicating increased stress. It is inferred that the observed physiological responses were mainly responsible for the negative effects on performance, as the subjects did not indicate any increased intensity of acute subclinical health symptoms although perceived air quality was worse at the higher temperature. The present results suggest that moderately elevated temperatures should be avoided even if thermal comfort can be achieved, as it may lead to reduced performance. 相似文献
1000.
In this study, we examined the cognitive performance of subtropically acclimatized subjects at an extreme high indoor temperature and the effect of decreased humidity on the cognitive performance at the high temperature. Forty-eight healthy subjects experienced the three exposure conditions: 26°C/relative humidity (RH) 70%, 39°C/RH50%, and 39°C/RH70% in a climate chamber. During 140-minute-long exposures to each thermal condition, they were required to perform cognitive tests that assess the perception, spatial orientation, concentration, memory, and thinking abilities. Meanwhile, their heart rate, core temperature, skin temperature, blood pressure, and body weight were measured and subjective responses, that is, thermal comfort, perceived air quality, and acute health symptoms were investigated. At the relative humidity of 70%, increasing indoor temperature from 26°C to 39°C caused a significant decrease in the accuracy of these cognitive tests. However, when the relative humidity decreased from 70% to 50% at 39°C, the accuracy of the cognitive tests increased significantly. Accordingly, the physiological and subjective responses of the subjects changed significantly with the changes in indoor temperature and humidity, which provided a basis to the variation in the cognitive performance. These results indicated that decreasing indoor humidity at extreme high temperature could improve the impaired cognitive performance. 相似文献