A Survey: Face Recognition by Sparse Representation

Face recognition is very helpful in many applications such as video surveillance, forensic applications criminal investigations, and in many other fields. The most common methods includes PCA approach based Eigenface, Linear Discriminant Analysis(LDA), Hidden Markov Model(HMM),DWT, geometry based and template matching approaches.In this paper we are using sparse representation approach to attain more robustness to variation in lighting, directions and expressions. This survey paper performs analysis on different approaches and factors affecting the face recognition

BRAIN MR IMAGE SEGMENTATION BY MODIFIED ACTIVE CONTOURS AND CONTOURLET TRANSFORM

Multiresolution analysis is often used for image representation and processing because it can represent image at the split resolution and scale space. In this paper, a novel medical image segmentation algorithm is proposed that combines contourlet transform and modified active contour model. This method has a new energy formulation by representing the image with the coefficients of a contourlet transform. This results fast and accurate convergence of the contour towards the object boundary. Medical image segmentation using contourlet transforms has shown significant improvement towards the weak and blurred edges of the Magnetic Resonance Image (MRI). Also, the computational complexity is less compared to using traditional level sets and variational level sets for medical image segmentation. The special property of the contourlet transform is that, the directional information is preserved in each sub-band and is captured by computing its energy. This energy is capable of enhancing weak and complex boundaries in details. Performance of medical image segmentation algorithm using contourlet transform is compared with other deformable models in terms of various performance measures

Evaluation of Ultrasound Based Acoustic Radiation Force Impulse (ARFI) and eSie touch Sonoelastography for Diagnosis of Inflammatory Pancreatic Diseases

Context Pathology changes the consistency of the tissues. Objective To prospectively assess the accuracy of per-abdominal US elastography in the form of acoustic radiation force impulse - virtual touch tissue quantification (ARFI-VTQ) and eSie touch elasticity imaging in characterizing and differentiating inflammatory pancreatic diseases. Patients One-hundred and 66 patients from among the patients that visited the Asian Institute of Gastroenterology, Hyderabad, India, during the period April 2009 to December 2010, for master health check-up, blood donation and those with pancreatic pathology. Setting Based on the clinical symptomatic criteria and diagnostic imaging findings, the patients were divided into normal, chronic and acute, or acute resolving, pancreatitis group. Main outcome measures The ultrasound based ARFI-VTQ and eSie touch elasticity imaging techniques were applied. Design Prospective single-center study. Results The mean ARFI-VTQ values were 1.28 m/s, 1.25 m/s and 3.28 m/s for the normal, chronic and acute pancreas, respectively. The eSie touch gray scale and color elastograms were light gray and purple-greenish, respectively for both normal and chronic pancreas, while for acute pancreas the elastograms were dark black on the gray scale and orange to red on color scale. Conclusion Both the ARFI-VTQ and eSie touch elasticity imaging techniques may be successfully adopted in order to diagnose acute pancreatitis, to assess extent of inflammation (whether focal or diffuse), to assess peripancreatic edema, to identify presence of necrotic areas and early pseudocyst formation, to early diagnose acute recurrent attacks and to monitor patient’s response to treatment

Evaluation of a novel Y-shaped extracardiac Fontan baffle using computational fluid dynamics

ObjectivesThe objective of this work is to evaluate the hemodynamic performance of a new Y-graft modification of the extracardiac conduit Fontan operation. The performance of the Y-graft design is compared to two designs used in current practice: a t-junction connection of the venae cavae and an offset between the inferior and superior venae cavae.MethodsThe proposed design replaces the current tube grafts used to connect the inferior vena cava to the pulmonary arteries with a Y-shaped graft. Y-graft hemodynamics were evaluated at rest and during exercise with a patient-specific model from magnetic resonance imaging data together with computational fluid dynamics. Four clinically motivated performance measures were examined: Fontan pressures, energy efficiency, inferior vena cava flow distribution, and wall shear stress. Two variants of the Y-graft were evaluated: an “off-the-shelf” graft with 9-mm branches and an “area-preserving” graft with 12-mm branches.ResultsEnergy efficiency of the 12-mm Y-graft was higher than all other models at rest and during exercise, and the reduction in efficiency from rest to exercise was improved by 38%. Both Y-graft designs reduced superior vena cava pressures during exercise by as much as 5 mm Hg. The Y-graft more equally distributed the inferior vena cava flow to both lungs, whereas the offset design skewed 70% of the flow to the left lung. The 12-mm graft resulted in slightly larger regions of low wall shear stress than other models; however, minimum shear stress values were similar.ConclusionsThe area-preserving 12-mm Y-graft is a promising modification of the Fontan procedure that should be clinically evaluated. Further work is needed to correlate our performance metrics with clinical outcomes, including exercise intolerance, incidence of protein-losing enteropathy, and thrombus formation

Mean Dietary Salt Intake in Urban and Rural Areas in India: A Population Survey of 1395 Persons.

BACKGROUND: The scientific evidence base in support of population-wide salt reduction is strong, but current high-quality data about salt intake levels in India are mostly absent. This project sought to estimate daily salt consumption levels in selected communities of Delhi and Haryana in north India and Andhra Pradesh in south India. METHODS AND RESULTS: In this study, 24-hour urine samples were collected using an age- and sex-stratified sampling strategy in rural, urban, and slum areas. Salt intake estimates were made for the overall population of each region and for major subgroups by weighting the survey data for the populations of Delhi and Haryana, and Andhra Pradesh. Complete 24-hour urine samples were available for 637 participants from Delhi and Haryana and 758 from Andhra Pradesh (65% and 68% response rates, respectively). Weighted mean population 24-hour urine excretion of salt was 8.59 g/day (95% CI 7.68-9.51) in Delhi and Haryana and 9.46 g/day (95% CI 9.06-9.85) in Andhra Pradesh (P=0.097). Estimates inflated to account for the minimum likely nonurinary losses of sodium provided corresponding estimates of daily salt intake of 9.45 g/day (95% CI 8.45-10.46) and 10.41 g/day (95% CI 9.97-10.84), respectively. CONCLUSIONS: Salt consumption in India is high, with mean population intake well above the World Health Organization recommended maximum of 5 g/day. A national salt reduction program would likely avert much premature death and disability

Sleep disordered breathing in chronic obstructive pulmonary disease

We prospectively studied sleep disordered breathing in 50 consecutive patients (39 males) with chronic obstructive pulmonary disease (COPD) with chronic respiratory failure (CRF) (n=33) and without CRF (n=17) by performing polysomnography. Patients with CRF had a lower mean nocturnal oxygen saturation (SaO2 %) (88.6±6.7 vs. 96.3±0.8; p=0.0001) and a lower minimal nocturnal SaO2 (73.6±12.0 vs. 84.3±7.3; p=0.002) compared to those without CRF, suggesting that patients with CRF tend to have more severe drops in nocturnal SaO2. Patients with CRF also had a lower FEV1 (% predicted) (p=0.01) and PEFR (% predicted) (p=0.031) compared to those without CRF suggesting an indirect relation to the oxygen saturation. Other pulmonary functions were comparable between both the groups. Among patients with and without CRF, the total sleep time (minutes); the rapid eye movement (REM) stage (% of total sleep time); the non-rapid eye movement (NREM) stage (% of total sleep time) were comparable (p=NS). Only three of the 50 patients with COPD had a significant (>5) apnea-hypopnea index (AHI) (total no. of apneas + total no. of hypopneas/ total sleep time [(hours) = AHI] and these three patients had a mean BMI = 27.7 which was higher than the mean BMI of the whole group (21.1). The AHI was comparable in patients with and without respiratory failure. Multiple regression analysis revealed a positive correlation between AHI and the neck circumference (r=0.41; p=0.005) and BMI (r=0.31; p=NS). There was a small but statistically insignificant negative correlation between AHI and neck length (r= −0.28; p=NS). We conclude that, BMI per se contributes to the AHI and nocturnal desaturation in patients with COPD

TCF7L2 gene polymorphisms do not predict susceptibility to diabetes in tropical calcific pancreatitis but may interact with SPINK1 and CTSB mutations in predicting diabetes

<p>Abstract</p> <p>Background</p> <p>Tropical calcific pancreatitis (TCP) is a type of chronic pancreatitis unique to developing countries in tropical regions and one of its important features is invariable progression to diabetes, a condition called fibro-calculous pancreatic diabetes (FCPD), but the nature of diabetes in TCP is controversial. We analysed the recently reported type 2 diabetes (T2D) associated polymorphisms in the <it>TCF7L2 </it>gene using a case-control approach, under the hypothesis that <it>TCF7L2 </it>variants should show similar association if diabetes in FCPD is similar to T2D. We also investigated the interaction between the <it>TCF7L2 </it>variants and N34S <it>SPINK1 </it>and L26V <it>CTSB </it>mutations, since they are strong predictors of risk for TCP.</p> <p>Methods</p> <p>Two polymorphisms rs7903146 and rs12255372 in the <it>TCF7L2 </it>gene were analyzed by direct sequencing in 478 well-characterized TCP patients and 661 healthy controls of Dravidian and Indo-European ethnicities. Their association with TCP with diabetes (FCPD) and without diabetes was tested in both populations independently using chi-square test. Finally, a meta analysis was performed on all the cases and controls for assessing the overall significance irrespective of ethnicity. We dichotomized the whole cohort based on the presence or absence of N34S <it>SPINK1 </it>and L26V <it>CTSB </it>mutations and further subdivided them into TCP and FCPD patients and compared the distribution of <it>TCF7L2 </it>variants between them.</p> <p>Results</p> <p>The allelic and genotypic frequencies for both <it>TCF7L2 </it>polymorphisms, did not differ significantly between TCP patients and controls belonging to either of the ethnic groups or taken together. No statistically significant association of the SNPs was observed with TCP or FCPD or between carriers and non-carriers of N34S <it>SPINK1 </it>and L26V <it>CTSB </it>mutations. The minor allele frequency for rs7903146 was different between TCP and FCPD patients carrying the N34S <it>SPINK1 </it>variant but did not reach statistical significance (OR = 1.59, 95% CI = 0.93–2.70, P = 0.09), while, <it>TCF7L2</it><it/>variant showed a statistically significant association between TCP and FCPD patients carrying the 26V allele (OR = 1.69, 95% CI = 1.11–2.56, P = 0.013).</p> <p>Conclusion</p> <p>Type 2 diabetes associated <it>TCF7L2 </it>variants are not associated with diabetes in TCP. Since, <it>TCF7L2 </it>is a major susceptibility gene for T2D, it may be hypothesized that the diabetes in TCP patients may not be similar to T2D. Our data also suggests that co-existence of <it>TCF7L2 </it>variants and the <it>SPINK1 </it>and <it>CTSB </it>mutations, that predict susceptibility to exocrine damage, may interact to determine the onset of diabetes in TCP patients.</p

Dietary Intake and Rural-Urban Migration in India: A Cross-Sectional Study

BACKGROUND: Migration from rural areas of India contributes to urbanisation and lifestyle change, and dietary changes may increase the risk of obesity and chronic diseases. We tested the hypothesis that rural-to-urban migrants have different macronutrient and food group intake to rural non-migrants, and that migrants have a diet more similar to urban non-migrants. METHODS AND FINDINGS: The diets of migrants of rural origin, their rural dwelling sibs, and those of urban origin together with their urban dwelling sibs were assessed by an interviewer-administered semi-quantitative food frequency questionnaire. A total of 6,509 participants were included. Median energy intake in the rural, migrant and urban groups was 2731, 3078, and 3224 kcal respectively for men, and 2153, 2504, and 2644 kcal for women (p<0.001). A similar trend was seen for overall intake of fat, protein and carbohydrates (p<0.001), though differences in the proportion of energy from these nutrients were <2%. Migrant and urban participants reported up to 80% higher fruit and vegetable intake than rural participants (p<0.001), and up to 35% higher sugar intake (p<0.001). Meat and dairy intake were higher in migrant and urban participants than rural participants (p<0.001), but varied by region. Sibling-pair analyses confirmed these results. There was no evidence of associations with time in urban area. CONCLUSIONS: Rural to urban migration appears to be associated with both positive (higher fruit and vegetables intake) and negative (higher energy and fat intake) dietary changes. These changes may be of relevance to cardiovascular health and warrant public health interventions

The Effect of Rural-to-Urban Migration on Obesity and Diabetes in India: A Cross-Sectional Study

Shah Ebrahim and colleagues examine the distribution of obesity, diabetes, and other cardiovascular risk factors among urban migrant factory workers in India, together with their rural siblings. The investigators identify patterns of change of cardiovascular risk factors associated with urban migration

Progress in Classical and Quantum Variational Principles

We review the development and practical uses of a generalized Maupertuis least action principle in classical mechanics, in which the action is varied under the constraint of fixed mean energy for the trial trajectory. The original Maupertuis (Euler-Lagrange) principle constrains the energy at every point along the trajectory. The generalized Maupertuis principle is equivalent to Hamilton's principle. Reciprocal principles are also derived for both the generalized Maupertuis and the Hamilton principles. The Reciprocal Maupertuis Principle is the classical limit of Schr\"{o}dinger's variational principle of wave mechanics, and is also very useful to solve practical problems in both classical and semiclassical mechanics, in complete analogy with the quantum Rayleigh-Ritz method. Classical, semiclassical and quantum variational calculations are carried out for a number of systems, and the results are compared. Pedagogical as well as research problems are used as examples, which include nonconservative as well as relativistic systems