Debris cover on glacier boundaries critically impedes the global inventorying of glaciers and confounds most of the techniques developed for semi-automated mapping of glaciers. Debris on the glacier ...(referred as supraglacial debris) and that occurring outside the glacier boundaries (referred as periglacial debris) being derived from a common source, i.e. the valley rock, tend to have a similar spectral response in the reflection region which renders them mutually indistinguishable. However, there exist temperature differences between them. This aspect has been considered in this remote sensing based study to distinguish between the supraglacial and periglacial debris in a test area in the Chenab basin, Himalayas, by inclusion of thermal infrared (TIR) bands in remote sensing data processing. A synergistic multisensor approach for the delineation of debris-covered glacier boundaries is used here which integrates the inputs from thermal (TERRA-ASTER sensor) and optical (IRS-P6-AWiFS sensor) remote sensing data, multispectral classification techniques and the DEM derived geomorphometric parameters. The results of this study corroborate earlier findings on utilization of temperature differences as one of the parameters in glacial studies. The proposed synergistic approach therefore appears useful in accurate mapping of debris-covered glaciers in the Himalayan region.
Abstract Background Remote, non-invasive and objective tests that can be used to support expert diagnosis for Parkinson's disease (PD) are lacking. Methods Participants underwent baseline in-clinic ...assessments, including the Unified Parkinson's Disease Rating Scale (UPDRS), and were provided smartphones with an Android operating system that contained a smartphone application that assessed voice, posture, gait, finger tapping, and response time. Participants then took the smart phones home to perform the five tasks four times a day for a month. Once a week participants had a remote (telemedicine) visit with a Parkinson disease specialist in which a modified (excluding assessments of rigidity and balance) UPDRS performed. Using statistical analyses of the five tasks recorded using the smartphone from 10 individuals with PD and 10 controls, we sought to: (1) discriminate whether the participant had PD and (2) predict the modified motor portion of the UPDRS. Results Twenty participants performed an average of 2.7 tests per day (68.9% adherence) for the study duration (average of 34.4 days) in a home and community setting. The analyses of the five tasks differed between those with Parkinson disease and those without. In discriminating participants with PD from controls, the mean sensitivity was 96.2% (SD 2%) and mean specificity was 96.9% (SD 1.9%). The mean error in predicting the modified motor component of the UPDRS (range 11–34) was 1.26 UPDRS points (SD 0.16). Conclusion Measuring PD symptoms via a smartphone is feasible and has potential value as a diagnostic support tool.
Landslides are one of the most destructive phenomena of nature that cause damage to both property and life every year, and therefore, landslide susceptibility zonation (LSZ) is necessary for planning ...future developmental activities. In this paper, apart from conventional weighting system, objective weight assignment procedures based on techniques such as artificial neural network (ANN), fuzzy set theory and combined neural and fuzzy set theory have been assessed for preparation of LSZ maps in a part of the Darjeeling Himalayas. Relevant thematic layers pertaining to the causative factors have been generated using remote sensing data, field surveys and Geographic Information System (GIS) tools. In conventional weighting system, weights and ratings to the causative factors and their categories are assigned based on the experience and knowledge of experts about the subject and the study area to prepare the LSZ map (designated here as Map I). In the context of objective weight assignments, initially the ANN as the black box approach has been used to directly produce an LSZ map (Map II). In this approach, however, the weights assigned are hidden to the analyst. Next, the fuzzy set theory has then been implemented to determine the membership values for each category of the thematic layer using the cosine amplitude method (similarity method). These memberships are used as ratings for each category of the thematic layer. Assuming weights of each thematic layer as one (or constant), these ratings of the categories are used for the generation of another LSZ map (Map III). Subsequently, a novel weight assignment procedure based on ANN is implemented to assign the weights to each thematic layer objectively. Finally, weights of each thematic layer are combined with fuzzy set derived ratings to produce another LSZ map (Map IV). The maps I–IV have been evaluated statistically based on field data of existing landslides. Amongst all the procedures, the LSZ map based on combined neural and fuzzy weighting (i.e., Map IV) has been found to be significantly better than others, as in this case only 2.3% of the total area is found to be categorized as very high susceptibility zone and contains 30.1% of the existing landslide area.
Background and Aims: Propofol is a commonly used sedative agent, in a dose of 1.5-4.5 mg.kg-1.h-1. Following liver transplantation (LT), drug metabolism may be altered due to liver mass, altered ...hepatic blood flow, reduced levels of serum proteins, and liver regeneration. Thus, we hypothesized that propofol requirements in this group of patients would be different as compared to the standard dose. This study evaluated the dose of propofol used for sedation in electively ventilated living donor liver transplantation (LDLT) recipients.
Material and Methods: After patients were shifted to the postoperative intensive care unit (ICU) following LDLT surgery, propofol infusion was started at a dose of 1 mg.kg-1.h-1 and titrated to maintain a bispectral index (BIS) value of 60-80. No other sedatives such as opioids or benzodiazepines were used. Dose of propofol, noradrenaline, and arterial lactate levels were noted 2 hourly.
Results: The mean propofol dose required in these patients was 1.02 ± 0.26 mg.kg-1.h-1. Noradrenaline was gradually tapered off and stopped within 14 h of shifting to ICU. The mean duration between the time of cessation of propofol infusion till extubation was 2.06 ± 1.44 h. Propofol dose did not correlate with respective lactate levels, ammonia levels, or graft-to-recipient weight ratio.
Conclusion: The dose range of propofol required for postoperative sedation in LDLT recipients was lower than the conventional dose.
A systematic study on the
in vitro interactions of 7–20
nm spherical silver nanoparticles (SNP) with HT-1080 and A431 cells was undertaken as a part of an on-going program in our laboratory to ...develop a topical antimicrobial agent for the treatment of burn wound infections.
Upon exposure to SNP (up to 6.25
μg/mL), morphology of both the cell types remained unaltered. However, at higher concentrations (6.25–50
μg/mL) cells became less polyhedral, more fusiform, shrunken and rounded. IC
50 values for HT-1080 and A431 as revealed by XTT assay were 10.6 and 11.6
μg/mL, respectively. When the cells were challenged with ∼1/2 IC
50 concentration of SNP (6.25
μg/mL), clear signs of oxidative stress, i.e. decreased GSH (∼2.5-folds in HT-1080, ∼2-folds in A431) and SOD (∼1.6-folds in HT-1080, 3-folds in A431) as well as increased lipid peroxidation (∼2.5-folds in HT-1080, ∼2-folds in A431) were seen. Changes in the levels of catalase and GPx in A431 cells were statistically insignificant in both cell types. DNA fragmentation in SNP-exposed cells suggested apoptosis. When the apoptotic thresholds of SNP were monitored with caspase-3 assay the concentrations required for the onset of apoptosis were found to be much lower (0.78
μg/mL in HT-1080, 1.56
μg/mL in A431) than the necrotic concentration (12.5
μg/mL in both cell types). These results can be used to define a safe range of SNP for the intended application as a topical antimicrobial agent after appropriate
in vivo studies.
Primary cells are ideal for
in vitro toxicity studies since they closely resemble tissue environment. Here, we report a detailed study on the
in vitro interactions of 7–20 nm spherical silver ...nanoparticles (SNP) with primary fibroblasts and primary liver cells isolated from Swiss albino mice. The intended use of silver nanoparticles is in the form of a topical antimicrobial gel formulation for the treatment of burns and wounds.
Upon exposure to SNP for 24 h, morphology of primary fibroblasts and primary liver cells remained unaltered up to 25 μg/mL and 100 μg/mL SNP, respectively, although with minor decrease in confluence. IC
50 values for primary fibroblasts and primary liver cells as revealed by XTT assay were 61 μg/mL and 449 μg/mL, respectively. Ultra-thin sections of primary cells exposed to 1/2 IC
50 SNP for 24 h, visualized under Transmission electron microscope showed the presence of dark, electron dense, spherical aggregates inside the mitochondria, and cytoplasm, probably representing the intracellular SNP. When the cells were challenged with ∼
1/2 IC
50 concentration of SNP (i.e. 30 μg/mL and 225 μg/mL for primary fibroblasts and primary liver cells, respectively), enhancement of GSH (∼
1.2 fold) and depletion of lipid peroxidation (∼
1.4 fold) were seen in primary fibroblasts which probably protect the cells from functional damage. In case of primary liver cells; increased levels of SOD (∼
1.4 fold) and GSH (∼
1.1 fold) as compared to unexposed cells were observed. Caspase-3 activity assay indicated that the SNP concentrations required for the onset of apoptosis were found to be much lower (3.12 μg/mL in primary fibroblasts, 12.5 μg/mL in primary liver cells) than the necrotic concentration (100 μg/mL in primary fibroblasts, 500 μg/mL in primary liver cells). These observations were confirmed by CLSM studies by exposure of cells to 1/2 IC
50 SNP (resulting in apoptosis) and 2× IC
50) cells (resulting in necrosis).
These results clearly suggest that although silver nanoparticles seem to enter the eukaryotic cells, cellular antioxidant mechanisms protect the cells from possible oxidative damage. This property, in conjunction with the finding that primary cells possess much higher SNP tolerance than the concentration in the gel (∼
20 μg/g), indicates preliminary safety of the formulation and warrants further study for possible human application.
Background
The ideal method for managing concomitant gallbladder stones and common bile duct (CBD) stones is debatable. The currently preferred method is two-stage endoscopic stone extraction ...followed by laparoscopic cholecystectomy (LC). This prospective randomized trial compared the success and cost effectiveness of single- and two-stage management of patients with concomitant gallbladder and CBD stones.
Methods
Consecutive patients with concomitant gallbladder and CBD stones were randomized to either single-stage laparoscopic CBD exploration and cholecystectomy (group 1) or endoscopic retrograde cholangiopancreatography (ERCP) for endoscopic extraction of CBD stones followed by LC (group 2). Success was defined as complete clearance of CBD and cholecystectomy by the intended method. Cost effectiveness was measured using the incremental cost-effectiveness ratio. Intention-to-treat analysis was performed to compare outcomes.
Results
From February 2009 to October 2012, 168 patients were randomized: 84 to the single-stage procedure (group 1) and 84 to the two-stage procedure (group 2). Both groups were matched with regard to demographic and clinical parameters. The success rates of laparoscopic CBD exploration and ERCP for clearance of CBD were similar (91.7 vs. 88.1 %). The overall success rate also was comparable: 88.1 % in group 1 and 79.8 % in group 2 (
p
= 0.20). Direct choledochotomy was performed in 83 of the 84 patients. The mean operative time was significantly longer in group 1 (135.7 ± 36.6 vs. 72.4 ± 27.6 min;
p
≤ 0.001), but the overall hospital stay was significantly shorter (4.6 ± 2.4 vs. 5.3 ± 6.2 days;
p
= 0.03). Group 2 had a significantly greater number of procedures per patient (
p
< 0.001) and a higher cost (
p
= 0.002). The two groups did not differ significantly in terms of postoperative wound infection rates or major complications.
Conclusions
Single- and two-stage management for uncomplicated concomitant gallbladder and CBD stones had similar success and complication rates, but the single-stage strategy was better in terms of shorter hospital stay, need for fewer procedures, and cost effectiveness.
Landslides cause widespread damage in the Himalayas. Landslide Hazard Zonation is important to take quick and safe mitigation measures and make strategic planning for the future. A part of the ...Bhagirathi Valley in the Garhwal Himalaya was selected for landslide hazard zonation. The study utilized different types of data including Survey of India topographic maps, geological (lithological and structural) maps, IRS-1B and-1D multispectral and PAN satellite sensor data and field observations. The processing of multi-geodatasets was carried out in a raster GIS environment. The various data layers generated and co-registered were: landuse/landcover, buffer map of thrusts, buffer map of photo-lineaments, lithology, buffer map of drainage, slope angle and relative relief. Data integration was carried out using the ordinal scale (qualitative) relative weighting rating technique to give a Landslide Hazard Index (LHI) value. The breaks in the LHI frequency diagram were used to delineate various landslide hazard zones, namely, very low, low, moderate, high and very high. Field data on landslides were employed to evaluate and validate landslide hazard zonation map. It is interpreted that the distribution of landslides is largely governed by a combination of geoenvironmental conditions like proximity (>500 m) to the thrust zone, presence of Munsiari Formation (Higher Himalayan Crystalline) and barren or less-vegetated areas.
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•Fatigue life assessment analyses using existing popular critical plane models.•Developed a new model that is simple to use and less time consuming.•Developed model resulted in ...accurate fatigue life assessments for large strain paths.•The measured crack plane angles compare well with predicted crack orientations.
The present work is aimed at development of new critical plane model based on envelope of strain energy density as fatigue damage parameter. This model eliminates the use of hypotheses for evaluation of resultant shear. The fatigue life has been predicted and compared with test life for a large set of multi-axial test data available on SA 333 Gr. 6, 16MnR, S460N and 7075-T651 Al materials. Predicted fatigue life is in good agreement with test life. The predicted crack initiation orientations are also comparable with the measured angles.
The shortcomings of existing models have been brought out.
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