420 research outputs found
Landslide monitoring using insar time-series and GPS observations, case study: Shabkola landslide in northern Iran
Shabkola is a village located in Mazandaran province of northern Iran that suffers from the mass movement happening in the upstream. Deforestation and changes to land use are the main reasons for the soil instability in this region, which together with steep slope, relatively high precipitation rate and natural erosion has led to such a condition. The area of mass movement is approximately 90 hectares which is a big threat for people living in the region. In this study, we have utilized two different geodetic techniques including InSAR time-series analysis and GPS measurements to assess slope stability in Shabkola. The SAR dataset includes 19 ALOS/PALSAR images spanning from July 2007 to February 2011 while GPS observations are collected in 5 campaigns from September 2011 to May 2014. Displacement as much as approximately 11.7 m in slope direction was detected by GPS observations for the 2011-2014 time period. Most of the slope geometry is in north-south direction, for which the sensitivity of InSAR for displacement detection is low. However, ALOS PALSAR data analysis revealed a previously unknown landslide, covered by dense vegetation in the northern part of main Shabkola landslide, showing line-of-sight velocity of approximately 2cm/year in the time period 2007-2011
Effect of valerian capsules in patients with migraine attacks treated with sodium valproate: a randomized clinical trial
Background and aims: Nowadays so many preventive drugs for migraine with different effects are used all around the world. One of the plants that are used traditionally in the treatment of migraine is Valeriana officinalis. The present study was aimed to evaluate the effect of valerian capsule (350 mg, three times daily) on frequency, duration and intensity of migraine attacks. Method: The present study is a Randomized, single-blind clinical trial that is carried out on 84 female patients suffering from migraine headaches. The patients were randomly allocated to case (n=42) and control groups (n=42) and treated during three consecutive phases of 45 days. In the first phase, both groups received sodium valproate tablet, (200 mg, twice daily) and indomethacin capsule (25 mg, in attacks). In the second phase, valerian capsule (350 mg, three times daily) was added to other drugs of case group. Control group received placebo instead of valerian. Finally, in the third phase, both groups were treated the same as the first phase. And then the data obtained from the drug influence on pain intensity were analyzed based on Mann-Whitney and K2. Results: All 84 patients cooperated to the end of study. The results indicated that valerian capsule significantly reduced the frequency, duration and intensity of migraine attacks in a way that the mean of migraine attacks reduced from 6.2±2.3 to 2.2±1.2, the duration reduced from 17.0± 9.2 to 5.7±3.7 hours and intensity from 8.7±1.2 to 3.0±1.3. Conclusion: According to the remarkable effect of valerian capsule on the prevention of migraine attacks, it seems that it can be a potential alternative to common migraine medications
Developing a Questionnaire for Iranian Women's Attitude on Medical Ethics in Vaginal Childbirth
Background: Vaginal delivery is one of the challenging issues in medical ethics. It is important to use an appropriate instrument to assess medical ethics attitudes in normal delivery, but the lack of tool for this purpose is clear.
Objectives: The aim of this study was to develop and validate a questionnaire for the assessment of women’s attitude on medical ethics application in normal vaginal delivery.
Patients and Methods: This methodological study was carried out in Iran in 2013 - 2014. Medical ethics attitude in vaginal delivery questionnaire (MEAVDQ) was developed using the findings of a qualitative data obtained from a grounded theory research conducted on 20 women who had vaginal childbirth, in the first phase. Then, the validation criteria of this tool were tested by content and face validity in the second phase. Exploratory factor analysis was used for construct validity and reliability was also tested by Cronbach’s alpha coefficient in the third phase of this study. SPSS version 13 was used in this study. The sample size for construct validity was 250 females who had normal vaginal childbirth.
Results: In the first phase of this study (tool development), by the use of four obtained categories and nine subcategories from grounded theory and literature review, three parts (98-items) of this tool were obtained (A, B and J). Part A explained the first principle of medical ethics, part B pointed to the second and third principles of medical ethics, and part J explained the fourth principle of medical ethics. After evaluating and confirming its face and content validity, 75 items remained in the questionnaire. In construct validity, by the employment of exploratory factor analysis, in parts A, B and J, 3, 7 and 3 factors were formed, respectively; and 62.8%, 64% and 51% of the total variances were explained by the obtained factors in parts A, B and J, respectively. The names of these factors in the three parts were achieved by consideration of the loading factor and medical ethics principles. The subscales of MEAVDQ showed significant reliability. In parts A, B and J, Cronbach’s alpha coefficients were 0.76, 0.72 and 0.68, respectively and for the total questionnaire, it was 0.72. The results of the test–retest were satisfactory for all the items (ICC = 0.60 - 0.95).
Conclusions: The present study showed that the 59-item MEAVDQ was a valid and reliable questionnaire for the assessment of women’s attitudes toward medical ethics application in vaginal childbirth. This tool might assist specialists in making a judgment and plan appropriate for women in vaginal delivery management
Smoothness-Increasing Accuracy-Conserving (SIAC) filtering and quasi interpolation: A unified view
Filtering plays a crucial role in postprocessing and analyzing data in scientific and engineering applications. Various application-specific filtering schemes have been proposed based on particular design criteria. In this paper, we focus on establishing the theoretical connection between quasi-interpolation and a class of kernels (based on B-splines) that are specifically designed for the postprocessing of the discontinuous Galerkin (DG) method called Smoothness-Increasing Accuracy-Conserving (SIAC) filtering. SIAC filtering, as the name suggests, aims to increase the smoothness of the DG approximation while conserving the inherent accuracy of the DG solution (superconvergence). Superconvergence properties of SIAC filtering has been studied in the literature. In this paper, we present the theoretical results that establish the connection between SIAC filtering to long-standing concepts in approximation theory such as quasi-interpolation and polynomial reproduction. This connection bridges the gap between the two related disciplines and provides a decisive advancement in designing new filters and mathematical analysis of their properties. In particular, we derive a closed formulation for convolution of SIAC kernels with polynomials. We also compare and contrast cardinal spline functions as an example of filters designed for image processing applications with SIAC filters of the same order, and study their properties
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