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91.
The study reported here aims to identify the extent of back pain experienced by 11-14 year old schoolchildren, and establish the intensity, duration and frequency of exposure to physical risk factors present in schools. This paper considers the sitting postures of schoolchildren in the classroom. The sitting postures of 66 children were recorded in normal lessons using the Portable Ergonomic Observation Method (PEO). The study found significant associations between flexed postures and low back pain. Static postures and neck and upper back pain were also associated. This study has implications for schools, designers and people in the field of work related musculoskeletal disorders. Further research is required to examine the association between sitting posture and pain reported at different spinal locations. 相似文献
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The use of robots, especially autonomous mobile robots, to support work is expected to increase over the next few decades. However, little empirical research examines how users form mental models of robots, how they collaborate with them, and what factors contribute to the success or failure of human-robot collaboration. A two-year observational study of a collaborative human-robot system suggests that the factors disrupting the creation of common ground for interactive communication change at different levels of robot autonomy. Our observations of users collaborating with the remote robot showed differences in how the users reached common ground with the robot in terms of an accurate, shared understanding of the robot's context, planning, and actions - a process called grounding. We focus on how the types and levels of robot autonomy affect grounding. We also examine the challenges a highly autonomous system presents to people's ability to maintain a shared mental model of the robot 相似文献
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Radium analysis is carried out by batch adsorption from natural waters on basic lead rhodizonate supported on charcoal, LERHO, starting from 2-L samples. 133Ba is added to allow the measurement of the overall chemical yield by gamma counting. Radium is recovered with a few milliliters of 1.5 M HCl, and lead is removed by a chromatographic column filled with Dowex 2 x 8. Finally 50 micrograms of barium carrier is added, and the radium is coprecipitated as sulfate on a preformed bed of barium sulfate, to prepare a sample suitable for alpha and gamma counting. The detection limit of the proposed method is 0.002 Bq/L 226Ra. This value is far beyond the radium activity admissible for drinking waters. Due to lack of appropriate samples, the procedure was tested using mineral waters spiked with 226Ra and two commercially available mineral waters with very low radium contents. 相似文献
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Interstitial implantation is invaluable in the management of patients with extensive or large volume gynecologic malignancies, significant anatomical distortion, or recurrent disease. Such techniques are necessary components of the brachytherapy services available to patients with gynecologic malignancies giving superior results in terms of local tumor control and survival compared to those achieved with external beam alone or inadequate intracavitary applications. Local tumor control with an acceptable risk of complications can be achieved for these challenging disease presentations if these techniques are implemented skillfully through the joint efforts of the radiation oncologist and gynecologic surgeon. 相似文献
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PURPOSE: To evaluate short-term efficacy of awareness programs (AP) in reducing coronary heart disease risk factors (CHDRF). METHODS: High risk hypercholesterolemic patients were divided in 2 groups during 16 weeks. Group A (n = 417, 54.3 +/- 10.0 years, 55% males) received verbal and written orientation on CHDRF control, and group B (n = 180, 54.4 +/- 10.9 years, 45% males) received only verbal orientation. All participants received pravastatin 10 mg q.d. for 12 weeks. The evolution of body weight, arterial pressure, lipid profile, Castelli's I and II indexes (TC/HDL and LDL/HDL), and Framingham scores were evaluated. RESULTS: At baseline, A had a lower HDL-C (40.0 +/- 11.0 vs 43.0 +/- 11.0 mg/dl, p = 0.013) and a higher index I (8.2 +/- 3.0 vs 7.6 +/- 2.3, p = 0.008) than B. After 16 weeks, A had greater change than B in TC (-28.0 vs -25.0, p < 0.05), LDL-C (-29.0 vs -27.6, p < 0.05), HDL-C levels (+13.7 vs +10.8, p < 0.05) and in the Castelli's Index (-39.0 vs -33.0; p < 0.05). In both groups pravastatin use potentialized the effects of diet on the lipid profile. CONCLUSION: The AP seemed to be more effective than verbal orientation alone in CHDRF reduction at short-term. 相似文献