73 research outputs found
Hand Vein Pattern Recognition using Natural Image Statistics
Biometrics is the science of identifying a person using physiological or behavioural characteristics. Hand vein pattern is a recent and unique biometric feature which is used for high secure authentication of individuals. The dorsal hand contains dorsal metacarpal veins, dorsal venous network, cephalic vein and basilic vein. This paper presents an image descriptor which uses statistical structure of natural images. In this work, stack of natural image patches are used as filters and these transform an image into integer labels describing the small-scale appearance of the image. These labels are converted into histogram and it is used for further image analysis. The feature space contains binarized statistical image features. The proposed work is tested on NCUT dataset with state-of-the-art algorithms. The experimental results demonstrate that the proposed work outperforms of the state-of-the-art algorithms with the recognition rate of 99.80 per cent.Defence Science Journal, Vol. 65, No. 2, March 2015, pp.150-158, DOI:http://dx.doi.org/10.14429/dsj.65.731
A Dorsal Hand Vein Recognition-based on Local Gabor Phase Quantization with Whitening Transformation
The hand vein pattern is a biometric feature in which the actual pattern is the shape of the vein network and its characteristics are the vein features. This paper investigates a new approach for dorsal hand vein pattern identification from grey level dorsal hand vein information. In this study Gabor filter quadrature pair is employed to compute locally in a window for every pixel position to extract the phase information. The phases of six frequency coefficients are quantized and it is used to form a descriptor code for the local region. These local descriptors are decorrelated using whitening transformation and a histogram is generated for every pixel which describes the local pattern. Experiments are evaluated on North China University of Technology dorsal hand vein image dataset with minimum distance classifier and the results are analyzed for recognition rate, run time and equal error rate. The proposed method gives 100 per cent recognition rate and 1 per cent EER for fusion of both left and right hands.Defence Science Journal, 2014, 64(2), pp. 159-167. DOI: http://dx.doi.org/10.14429/dsj.64.465
STABILITY-INDICATING VALIDATED REVERSED PHASE-HIGH PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR SIMULTANEOUS DETERMINATION OF COBICISTAT AND ATAZANAVIR SULFATE IN BULK AND PHARMACEUTICAL DOSAGE FORM
ABSTRACTObjective: A simple, rapid, precise, accurate, and economical stability-indicating reversed phase-high performance liquid assay method was developedand validated for simultaneous estimation of cobicistat (COB) and atazanavir (ATV) sulfate in bulk drugs and their combined commercial tablets.Methods: The method has shown adequate separation of COB and ATV from their degradation products. Separation was achieved on a LunaCN (250 mm × 4.6 mm, 5 μm column at a detection wavelength of 239 nm) using a mobile phase consists of o-phthaldialdeyde (Ph2.5) IX buffer,acetonitrile, and methanol in the ratio of 40:40:20 in an isocratic elution mode at a flow rate of 1 ml/min. Results: The retention times for COB and ATV sulfate were found to be 3.606 and 6.113 min, respectively. COB and ATV sulfate, their combinationdrug product was subjected to acid, base, neutral hydrolysis, thermal, and photolytic stress conditions. Thus, stressed samples were analyzed by theproposed analytical method. Validation of the proposed analytical method was carried out as per ICH guidelines Q2R1. Quantitation was achievedwith UV detection at 239 nm based on peak area with linear calibration curves at concentration ranges 50-600 μg/ml for COB and 100-1200 μg/ml forATV sulfate (R2 = 0.999 for both drugs). The limits of detection were 0.25 μg/ml and 0.5 μg/ml for COB and ATV sulfate, respectively. Conclusion: The method was found to be specific and stability indicating as no interfering peaks of degradants and excipients were observed. Theproposed method is hence suitable for application in quality-control laboratories for quantitative analysis of both the drugs individually and incombination dosage forms since it is simple and rapid with good accuracy and precision.Keywords: Stability-indicating assay, Reversed phase-high performance liquid, Cobicistat, Atazanavir sulfate, Forced degradation studies
Effect of Cryogenic Chill on Mechanical Properties of ASTM A 494 M Grade Nickel Based Alloy Metal Matrix Composites
Mechanism of Charge Transfer in the Transition Metal Ion Doped TiO2 with Bicrystalline Framework of Anatase and Rutile: Photocatalytic and Photoelectrocatalytic Activity
The IPBES Conceptual Framework - connecting nature and people
The first public product of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) is its Conceptual Framework. This conceptual and analytical tool, presented here in detail, will underpin all IPBES functions and provide structure and comparability to the syntheses that IPBES will produce at different spatial scales, on different themes, and in different regions. Salient innovative aspects of the IPBES Conceptual Framework are its transparent and participatory construction process and its explicit consideration of diverse scientific disciplines, stakeholders, and knowledge systems, including indigenous and local knowledge. Because the focus on co-construction of integrative knowledge is shared by an increasing number of initiatives worldwide, this framework should be useful beyond IPBES, for the wider research and knowledge-policy communities working on the links between nature and people, such as natural, social and engineering scientists, policy-makers at different levels, and decision-makers in different sectors of society
Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)
Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
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