Background. Microsurgery is a surgical procedure requiring a high degree of precision and is commonly facilitated through the use of an intraoperative microscope. When operating the microscope system, the long-term posture leads to musculoskeletal disorders in surgeons, and seats are commonly employed to diminish these problems. The present study was conducted to evaluate musculoskeletal discomfort during work with a saddle seat in comparison with conventional seats for microscopic work. Methods. Two types of seats, a saddle and a conventional one, were evaluated for 73 microsurgical surgeons in terms of musculoskeletal discomfort. Corlett and Bishop's body part discomfort scale was used to assess musculoskeletal discomfort before and after working with the seats. Results. The highest amount of discomfort that microsurgical surgeons acquire in the workplace was focused on their neck, shoulders, arms and back. During work with a saddle seat, a significant reduction was found for discomfort values in the neck, shoulder, arm, back, elbow and forearm, as well as the whole body (p?<?0.05). Conclusion. This study showed that the use of saddle seats provides a more appropriate physical posture at work, and can decrease musculoskeletal discomfort in different parts of the body of microsurgical surgeons. 相似文献
Thompson (1990) introduced the adaptive cluster sampling design. This sampling design has been shown to be a useful sampling method for parameter estimation of a clustered and scattered population (Roesch, 1993; Smith et al., 1995; Thompson and Seber, 1996). Two estimators, the modified Hansen-Hurwitz (HH) and Horvitz-Thompson (HT) estimators, are available to estimate the mean or total of a population. Empirical results from previous researches indicate that the modified HT estimator has smaller variance than the modified HH estimator. We analytically compare the properties of these two estimators. Some results are obtained in favor of the modified HT estimator so that practitioners are strongly recommended to use the HT estimator despite easiness of computations for the HH estimator. 相似文献
The fresh and long preservation of the stock solution of the pentafluorobenzyl bromide were applied to determine the recovery yield of MCPA, 4-chloro-o-cresol and 5-chloro-3-methylcatechol from and preserved samples. Both fresh and preserved solution of the pentafluorobenzyl bromide confirmed almost the similar effect on the derivative yield of the compounds treated with fresh/preserved samples. The overall results differed significantly within different treatments. The yield decreased only 2 % with 5-chloro-3-methylcatechol. 相似文献
The drinking water of Naranji village and surrounding areas of the NorthWest Frontier Province (NWFP), Pakistan, was analyzed for its fluoride content. The fluoride content of water samples from the springs in the Naranji village goes up to 13.52 mg kg(-1), which exceeds the permissible limit (1.5 mg kg(-1)) set by the World Health Organization (WHO). This study explores the source of fluoride contamination and attributes it to the alkaline rocks of the Ambela granitic complex and the Koga complex. The low-lying areas towards the south have a fluoride content within the permissible limit. The Naranji area therefore needs urgent remedial measures. 相似文献
The seasonal variations of Chlorophyll-a was examined in relation to phytoplankton density and physico-chemical factors in Demird?ven Dam Reservoir during 2000-2001. Chlorophyll-a concentrations ranged from 0.62 to 7.19 mg/m3 and from 0.67 to 8.88 mg/m3 in 2000 and 2001, respectively. Maximum Chlorophyll-a concentrations were found near the metalimnion and decreased with depth. Chlorophyll-a concentrations showed positive correlation to phytoplankton density, water temperature and nutrient concentrations, and negative correlations to Secchi depth. Demird?ven Dam Reservoir can be classified as a mesotrophic reservoir according to Chlorophyll-a concentrations. 相似文献
ABSTRACT: Most forest lands are managed for multiple purposes, among them timber production and water supply. Conflicts often arise in such cases because logging is perceived as a threat to water quality. These conflicts can result from uncertain factual information, from differences in underlying social values, or from imbalances in the incidence of costs and benefits. Resulting conificts may go unresolved because existing institutional structures fail to address the real roots of the dispute. When such conificts go unresolved, benefits are often lost, and social, political, and managerial costs are high. This study found that the roots of conifict may lie in value differences or in interest impacts, but attention may be focused inappropriately and unproductively on factual issues. It suggests that at least some long-standing disputes in the management of forested watersheds may be resolved by identifying the root causes of these disputes and choosing those actions, whether they be changes in management guidelines or altered institutional structures, which are appropriate to those causes. 相似文献
Objective: It is estimated that road traffic accidents are globally responsible for approximately 1.2 million deaths and 20 to 50 million injuries. About 70% of traffic incidences (TIs) occur in developing countries and among countries with high TI rates; Iran is the first. The aim of this study was to measure the association between being responsible for a traffic accident and some vehicle, human; and environmental related factors in Yasuj, a city with a high incidence of road traffic injuries and deaths in Iran.
Methods: This is a time-, date-, and place-matched case–control study conducted in 2015 using all traffic accidents registered and investigated by police during 2012. In total, 194 drivers were considered the at-fault driver in a traffic accident and the 194 drivers in the same collisions were included in the analysis.
Results: Based on the results from multivariate conditional logistic regression, significant associations between vehicle maneuver (ORTurn to right or left/Moving forward = 11.10, 95% confidence interval [CI], 1.77–69.58, P = .01) and age (odds ratio [OR] = 1.11, 95% CI, 1.004–1.22, P = .04) and the chance of being an at-fault driver were found.
Conclusion: Driver behavior–related interventions including training and law enforcement seem to be more effective in reducing road traffic accidents in Iran. 相似文献
Climate change is affecting fishing communities across Bangladesh. While work has been undertaken to investigate the nature of these impacts, understanding how fishers perceive climate change at a local level, especially within developing countries, is crucial. This paper presents the results of a three-year study of the contextual determinants and dimensions of artisanal fishing community perceptions about climate change in coastal Bangladesh. Results of this study indicate that geographic characteristics, socio-economic status, worldviews, tradition, observations and disaster experiences are important determinants for shaping fishers’ perceptions about climate change. Fishers also demonstrate a long-standing tradition of risk adaptation strategies, but do not link them to climate change. We argue that these perceptions provide ideas for how to form appropriate climate responses at local levels not only in Bangladesh but other developing countries. 相似文献
Yttrium oxide nanoflowers were prepared by a hydrothermal technique, and X-ray diffraction and scanning electron microscopy were used to determine their structures. The cytotoxic and genotoxic potentials of aqueous dispersions of the nanoflowers to cultured primary rat hepatocytes were examined at concentrations up to 500 mg L?1 for 72 h. Cell viability was determined by monitoring the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, release of lactate dehydrogenase, and uptake of neutral red. Genotoxicity was assessed by the liver micronucleus assay. Exposure to Y2O3 nanoflowers at concentrations lower than 100 mg L?1 did not lead to any cytotoxicity or genotoxicity. At higher concentrations (200, 400, and 500 mg L?1), cell viability decreased and induction of micronuclei increased (400 and 500 mg L?1). 相似文献