Coupling of DEM and remote-sensing-based approaches for semi-automated detection of regional geostructural features in Zagros mountain, Iran.

In recent years, remote-sensing data have increasingly been used for the interpretation of objects and mapping in various applications of engineering geology. Digital elevation model (DEM) is very useful for detection, delineation, and interpretation of geological and structural features. The use of image elements for interpretation is a common method to extract structural features. In this paper, linear features were extracted from the Landsat ETM satellite image and then DEM was used to enhance those objects using digital-image-processing filtering techniques. The extraction procedures of the linear objects are performed in a semi-automated way. Photographic elements and geotechnical elements are used as main keys to extract the information from the satellite image data. This paper emphasizes on the application of DEM and usage of various filtering techniques with different convolution kernel size applied on the DEM. Additionally, this paper discusses about the usefulness of DEM and satellite digital data for extraction of structural features in SW of Zagros mountain, Iran

Landslides and active faults using remote sensing and GIS techniques in Central Alborz mountains, Iran

The attempt has been done on study of habitat factors for the distribution of 370 landsides. This study is based on landform features and landslides associated with active faults distribution using remote sensing, GIS and GPS techniques in the Central Alborz, North Iran. Field observations show that the mass movements on low angle occur most frequently near to active faults. In steep slopes avalanche and planar slides are dominant. In this study digital image processing has been done on the ASTER L1A, L1B and Landsat7 ETM+ images. GIS layers have been extracted from 370 historical landslides and active faults over the study area. Digital Elevation Model (DEM) (15m) has been generated from ASTER stereo pair data using PCI Geomatica 9.1 software. The use of a (15m) DEM is a potential substitute in tectonic activity analysis, as it highly correlates with slope instability, geomorphologic processes and factors affecting landslides. Appropriate landform parameters have been derived which are indicating landslides and faults distribution, exposure towards rain and snow. Tectonic classification schemes decomposing the landscape into basic landform-elements proved useful for characterizing a zonal, altitudinal landslide classes. The results show that more than 72 percent of landslide points are situated on the active faults buffer zone. It can be used as fundamental data for hazard prediction, land use planning and construction in study area

Effect of the time to intervention on the outcome of thrombosed dialysis access grafts managed percutaneously

PURPOSEWe aimed to investigate the effect of the time interval from the clinical presentation of a thrombosed dialysis access graft to intervention on procedure success. MATERIALS AND METHODSRecords from two academic institutions for patients who underwent percutaneous thrombectomy of occluded surgical hemodialysis graft access sites in interventional radiology from 2006 to 2011 were reviewed retrospectively. The following data were recorded: gender, age, time and date of the initial request for a thrombectomy and the procedure, age of the surgical access, angiographic outcome, and clinical outcome (successful or unsuccessful postinterventional dialysis). Univariate and multivariate logistic regression were used to evaluate whether the time to intervention significantly affected the study endpoint. RESULTSIn total, 268 percutaneous thrombectomies were performed in 139 patients. Of these 224 (83.5%) were categorized as successful and 44 (16.4%) as unsuccessful. The time to intervention was 19.9±30.1 vs. 22±35 hours for successful and unsuccessful procedures, respectively. The difference between the two was not significant, and there were also no significant differences in covariate distributions between successful and unsuccessful outcomes. CONCLUSIONDuring the first 72 hours following clinical presentation of a thrombosed dialysis access graft, time to intervention may be considered independent of procedure outcome

Geohazards analysis of Pisa tunnel in a fractured incompetent rocks in Zagros Mountains, Iran.

The Pisa 2 tunnel with 740 m in length and 20° N trend is located along the Kazerun fault zone in Simply Folded Belt of Zagros, Iran. This tunnel has been excavated in the fractured incompetent marl layers with high expansive pressure of up to 2 kg/cm2. In this study, the geological hazards along the tunnel have been recognized and categorized. This study revealed that, in the long-term usage of the tunnel, the lining did not endure against the loading and the secondary leakages. It is mainly attributed due to the non-efficiencies of drainage and isolation systems in the tunnel site. Therefore, it caused asphalt damage, drainage damage, and wall distortion. FLAC3D software has been used in this research. We conducted various analyses for pre-excavation stress states, syn-excavation, and post-excavation strain states. The results showed no indication of instability and critical deformations during the excavation time. It also revealed that due to the non-efficiencies of drainage and isolation systems against secondary leakages and consequently marl expansion, the volumetric and shear strains (i.e., expansions and displacements) have exceeded from the critical states of strain along the tunnel. For various remedy purpose, this paper attempted several measures that can be taken in order to modify the drainage and isolation systems along the tunnel area. The reconstruction of drainage systems with suitable reinforced concrete and adequate slope has been proposed. The width of channel and isolation of backside of lining and implementation of multi-order outlets (i.e., backside of lining) for draining of groundwater into where the main drainage systems are located in the tunnel gallery were suggested

Sulfur dioxide reduces hippocampal cells death and improves learning and memory deficits in rat model of transient global ischemia/reperfusion

Objective(s): According to recent the findings, sulfur dioxide (SO2) is produced by the cardiovascular system, influencing some major biological processes. Based on previous research, SO2 exhibits antioxidant effects and inhibits apoptosis following cardiac ischemia/reperfusion. Therefore, the objective of the current study was to examine the neuroprotective impact of SO2 following global cerebral ischemia/reperfusion (I/R).Materials and Methods: Forty-eight male Wistar rats that weighed 260–300 g, were randomly allocated into 4 groups: sham group (n=12), I/R group (n=12), and I/R+SO2 groups (NaHSO3 and Na2SO3; 1:3 ratio; 5 and 10 µg/kg, respectively; for 3 days, n=12). Cerebral ischemia model was prepared by occlusion of both common carotid arteries for 20 min. Saline as a vehicle and SO2 donor at doses 5 µg/kg (intraperitoneally) were injected for 3 days after reperfusion. Four days after ischemia, the passive avoidance memory test was carried out in four groups, and after behavioral assessment, necrosis, apoptosis, and antioxidant enzyme analysis were carried out.Results: SO2 treatment could significantly improve memory impairments in rats with cerebral ischemia/reperfusion (I/R) (

Coupling effect of ozone column and atmospheric infrared sounder data reveal evidence of earthquake precursor phenomena of Bam earthquake, Iran

Understanding the source mechanism of earthquakes may be the key to predict earthquakes. The testing of radioactive radiations and reactionary hypothesis of gases before and after quake events can help predict and monitor earthquake occurrence. In this study, the Atmospheric Infrared Sounder (AIRS) and the column ozone (O3) were applied to evaluate the December 26, 2003 earthquake of Bam city in western Iran. The results show that ozone concentration (column density) decreased about 30 DU and or 807 × 10E15/cm2 molecules. Using high-resolution AIRS data for the study area, we were able to discriminate gases that formed and changed before the main shock at least a day before the occurrence of the quake in Bam

Skin Protective Behavior Amongst Girl Students; Based on Health Belief Model

Skin cancer is the most prevalent type of cancer in most of the countries and more than 90% of cancer cases are related to ultra violet rays of the sun. Therefore protective behaviors against sunlight are considered the most essential measures for skin cancer prevention. This study has been conducted to determine the frequency of protective behavior against sunlight among female students of Tehran city high schools. The Health Belief Model has been used for this cross-sectional study to analyze the factors related to protective behaviors. A multi-phase sampling method was used. 941 female student of Tehran city high schools were studied using a probed question form. The data were then analyzed using SPSS software. During the study of protective behaviors against the sunlight, 24.7% of participants mentioned that they always use sunscreen. The behavior of using sunscreen is related to perceived sensitivity, severity and benefit amongst the students (P<0.05). Also 3.8% of the students who participated in our study were always using gloves in summer to protect against sunlight. The behavior of using gloves in summer was also related to perceived sensitivity, severity and benefit (P<0.05). Physicians were the most effective influencing people with 84.9% influence on the appropriate decision making by these students. There is a low frequency of protective behavior against sunlight among the female students of Tehran city high schools. These findings show the necessity of training the students in this regard and promote the protective behaviors amongst them

Monitoring of Maskun landslide and determining its quantitative relationship to different climatic conditions using D-InSAR and PSI techniques

Climate change has resulted in severe landslides in Maskun, Iran. This study evaluates and monitors the displacement caused by the landslide mass in Bam using Interferometry Synthetic Aperture Radar (DInSAR) and Persistent Scatterer Interferometry (PSI) techniques, as well as identifies relationships between climatic conditions and mass displacement. Temperature and precipitation data from 2007 to 2019 were combined with satellite images and the DInSAR method was used to determine the mass displacement differences after selecting eighteen radar images from the ASAR sensor of the ENVISAT satellite. Additionally, Sentinel 1 satellite images were acquired and analyzed using the PSI method from November 5, 2014, to June 24, 2019. The highest displacement level at the surface of the Maskun landslide mass was then extracted. The ASAR images show a monthly displacement rate of 7.3 mm. The smallest displacement, on the other hand, occurred between May and September 2009, at a rate of 3.1 mm/month. PSI results also revealed that the maximum Line Of Sight (LOS) velocities detected by PSI are −64.5 mm/yr (away from the satellite) and 32.45 mm/yr (toward the satellite). Rainfall is one of the main triggers for increasing the deformation of the Maskun landslide according to the time-series analysis

Patients’ Attitude and Feeling toward the Presence of Medical Students in Shahid Mostafa Khomeini Educational Clinics

Introduction : Patients are cornerstone of ambulatory teaching of medical students in clinics worldwide. Patient’s attitude and feeling towards the service they receive grounds for an increase in patients’ collaboration and consequently the quality of students’ clinical education. The aim of this study is to assess patient’s attitude and feeling toward the presence of medical students in educational clinics of Shahid Mostsfa Khomeini hospital.   Methods : This descriptive cross-sectional study was performed on 502 patients who visited 8 educational clinics of Shahid Mostafa Khomeini hospital in year 2013 who were selected through convenience sampling. Data was gathered using a researcher-made questionnaire. Face and content validity of the questionnaire as well as its reliability were confirmed using Chronbach’s Alpha (α=0.75). Statistical data analysis was performed using t-test and ANOVA.   Results: Mean score of patients’ feeling toward presence of medical students was 3.46±1 out of 5 total scores. In overall, 71.8% of patients were relaxed during history taking and examination by students. There was a significant statistical difference between mean and standard deviation of the feelings of patients informed about presence of students (3.81±0.73) and those non-informed (3.13±1.1) patients about negotiation (p=0.001, t=7.95). A significant difference was also observed between mean and standard deviation of the feelings of the patients toward examination and history taking by physicians of opposite gender (3.76±1) or the same gender (3.25±0.93) (p=0.001).   Conclusion : In general, patient’s felt comfortable about presence of medical students during history taking and examination. But in case of being further informed about presence of students and emphasis on their role on students’ training as well as being guaranteed about their privacy, this feeling will be increased among patients