A Noval Saliency Based Iris Segmentation Framework

Iris recognition is regarded as the most reliable and accurate biometric identification system available. In Iris recognition system, iris segmentation is the most time consuming and critical step, in concern to the accuracy of the process. This is a new method of iris segmentation based on the saliency map of an image. In this paper, first the saliency map which provides the visually important region has been designed to specifically locate the iris region. Then a color based masking is done to get the iris boundary. Since this method is computationally simple, a fast and reliable method which segment iris has been proposed. The reliability of the method has been checked with different eye images. The result also show that the proposed model is faster compared to the existing methods and gives a comparable accuracy

A laboratory study of nonlinear changes in the directionality of extreme seas

This paper concerns the description of surface water waves, specifically nonlinear changes in the directionality. Supporting calculations are provided to establish the best method of directional wave generation, the preferred method of directional analysis and the inputs on which such a method should be based. These calculations show that a random directional method, in which the phasing, amplitude and direction of propagation of individual wave components are chosen randomly, has benefits in achieving the required ergodicity. In terms of analysis procedures, the extended maximum entropy principle, with inputs based upon vector quantities, produces the best description of directionality. With laboratory data describing the water surface elevation and the two horizontal velocity components at a single point, several steep sea states are considered. The results confirm that, as the steepness of a sea state increases, the overall directionality of the sea state reduces. More importantly, it is also shown that the largest waves become less spread or more unidirectional than the sea state as a whole. This provides an important link to earlier descriptions of deterministic wave groups produced by frequency focusing, helps to explain recent field observations and has important practical implications for the design of marine structures and vessels

A study of the effect of incidental drug exposures, body mass index and diabetes on survival from melanoma

Introduction: Drugs intended to treat incidental medical conditions could moderate host-tumour interaction and therefore melanoma survival. Method: Drug exposure data were collected from the 2184 newly diagnosed melanoma patients in the Leeds Melanoma Cohort (recruited 2000-2012) and their primary care physicians. An ever-never analysis and drug usage at diagnosis of melanoma (including 12 months prior) were chosen as the most applicable analysis methods (overall and sex stratified). The effects of exposure to different classes of drugs on MSS and overall survival (OS) were then assessed using Cox Proportional Hazards models whilst adjusting for confounding variables including diabetes and BMI, firstly in unadjusted models followed by adjustment for known predictors of MSS in a multivariate model. Results: For most drugs there were no statistically significant effects on MSS. The drugs that I ultimately chose to look at in detail were aspirin, simvastatin and metformin. Whilst adjusting for age and Breslow thickness, women who had ever taken aspirin were significantly less likely to die from their melanoma compared with those who never used the drug at any point in their lifetime with hazard ratios (HR) for MSS of 0.51 (95% CI: 0.30-0.87, P= 0.014) compared to men with an HR (MSS) 0.99 (95% CI: 0.71-1.37, P= 0.948). With both ever/never use of simvastatin and at diagnosis (including 12 months prior) analysis, when adjusting for age and Breslow thickness, men had a significantly reduced risk of death from melanoma with HRs of 0.54 (95% CI: 0.37-0.79, P=0.002) and 0.57 (95% CI: 0.38-0.85, P=0.006) respectively when compared to females who had HRs of 1.22 (95% CI: 0.82-1.83, P=0.327) and 1.21 (95% CI: 0.79-1.86, P = 0.379). Metformin usage was negatively associated with MSS in individuals with primaries on the trunk, which was used here as a surrogate marker for BRAF mutated tumours with an HR of 3.87 (95% CI 1.29-11.57, P= 0.02) for chest primaries. Conclusion: The associations seen in my thesis require further validation in larger international data sets as well as examination of biological models to assess if these represent real effects or whether confounding factors are responsible for these changes. I would propose that future studies looking at factors influencing melanoma survival should consider stratifying their findings by sex

Case report of step cut osteotomy for cubitus varus: a superior surgical technique

Lateral closing wedge osteotomy is a commonly described procedure for correcting cosmetically unacceptable post-traumatic cubitus varus deformity in children. We report a case of 12-year-old boy who underwent step cut osteotomy for cubitus varus deformity. Preoperative measurements of varus deformity followed by planning of osteotomy using a template was done. Intraoperatively the preplanned cuts were made using a posterior approach and then fixation was done using k wire. Patient recovered completely with correction of deformity. Step cut osteotomy has key advantages over traditional closing wedge osteotomy and hence can be used as an alternative surgical technique.

Determination of cocaine in spiked saliva using liquid-liquid extraction and gas chromatography- mass selective detector methods

Over the past few years, there have been a rapid development in forensic drug testing in biological specimen. Urine and blood are the most commonly used biological matrices for detection of cocaine. However, there are some disadvantages such as invasive to the privacy and personal safety of the donor as well as the instability of the cocaine in that biological matrix. Therefore, in this study, saliva has been proposed as an alternative matrix since the collection of saliva is non-invasive and rapid. In this study, the liquid-liquid extraction (LLE) method was utilized to extract cocaine from saliva before the analysis was done using optimized conditions of gas chromatography and mass selective detector (GC-MSD). Diethylether: isopropanol with volume to solvent ratio 3:5 was used in this study. The optimized method was validated by evaluating calibration curve, linearity, limit of detection (LOD), limit of quantification (LOQ), percentage recovery and intra-assay and inter-assay precision accuracy. From the calibration curve (0.5-10 ppm), good coefficient of determination was obtained at r² = 0.9994. LOD and LOQ were obtained at 0.29 and 0.97 ppm respectively. From the precision and accuracy analysis of intra and inter-day, lower coefficient variance (intra: 1.96%; inter: 0.79%) and high accuracy were attained (intra: 102.33%; inter: 101.20%). A mean recovery of 85.20% with acceptable coefficient of variance (CV 70 % without addition of any preservatives or buffers. The study showed that the analysis of cocaine in saliva is robust, hence it can be used as an alternative matrix for forensic drug testing

Study on risk factors, clinico-radiological profile and the outcome in patients with acute cerebrovascular disease

BACKGROUND: Cerebrovascular disease is the most common cause of neurologicalmorbidity and mortality in adults. Stroke is the second most common cause of worldwide mortality. Stroke is a rising epidemic in India due to the increasing prevalence of hypertension, diabetes, dyslipidemia, the fast changing lifestyles and restructuring of the population. This devastating and disabling cerebrovascular disease with some amount of residual deficit leads onto economic burden. The etiology of stroke in majority of cases could be identified by a proper history taking, an adequate examination and judicious use of investigations including imaging of the brain. A hospital based descriptive study was done to identify the risk factors, clinico-radiological profile and the outcome of the patients presented with acute cerebrovascular disease. METHODOLOGY: A descriptive analytical study was conducted between April 2017 to September 2017 on 200 patients presented with acute cerebrovascular disease in Stanley medical college hospital, Chennai 01. The patients enrolled in the study were subjected to a detailed clinical history and physical examination. Clinical history was obtained from the relatives when the patient was having speech disturbances, altered sensorium and loss of consciousness. The investigations like Complete blood count, Renal function test, Fasting and postprandial sugars, Fasting lipid profile, Urine routine examination, Electrocardiogram, 2D ECHO, Computed tomography(CT brain) were done. The outcome was studied at the time of discharge by patient’s general condition, and was classified as Complete recovery (with no sequelae) ,Partial recovery(moderate sequelae) and Death. Data collected from 200 selected subjects was internally compared and statistically analysed by using descriptive and inferential statistics based on the formulated objectives of the study. RESULTS: Stroke was more common above the age of 61 years (74%); 61 to 80 years constituted 48%. Stroke in young was found only in 7% of patients. Mortality was more in males (6.5%) but there is no significant statistical difference between both gender and the outcome of Stroke. Motor weakness was the commonest presenting symptom (76%) in my study. Among risk factors,increased incidence of atrial fibrillation noted in complete recovery group compared to partial recoveryand death group. Analysis revealed statistically significant association between additive effect of smoking + consuming alcohol and outcome in patients with acute cerebrovascular disease. Majority of the patients in this study (80.5%) had cerebral infarct and MCA territory involvement was more common (57%).Hemorrhagic stroke was observed in 19.5% of patients with Intraparenchymal bleed (16.5%) and subarachnoid hemorrhage (3%);. CONCLUSION: Patients diagnosed with hemiplegia have greater risk and incidence of death compared to hemiparesis (which favours recovery) Patients presenting with clinical history of headache, vomiting, dizziness and gait disturbance have greater risk and incidence of death compared numbness, slurring of speech (which favours recovery) Patients presenting with atrial fibrillation as comorbidity have a higher incidence of complete recovery {cardio-embolic stroke} Patients presenting with additive effect of smoking+alcoholism have greater risk and incidence of death compared to either habits separately or no habits Patients presenting with CT diagnosis as hemorrhage have greater risk and incidence of death compared to infarct Patients presenting with posterior circulation involvement have greater risk and incidence of death compared to MCA/ACA vessel involvemen

An Analysis of Cost Efficiency and Loan Loss Provisioning Behaviour in Hong Kong Commercial Banks

This study examines Cost Efficiency and Loan loss provisioning in Hong Kong commercial banks between the years 2009-2014 for a sample of 23 banks. While much research explores discretionary provision determinants we argue that it is also important to access non-discretionary determinants of loan loss provisioning as well. So along with income smoothing, capital management hypothesis we further investigate cost efficiency and bank insolvency (Z-score) as possible determinants of loan loss provisions. To do so we use Cost efficiency function using SFA and a dynamic system GMM is used for Loan loss provisions model. We find that for Hong Kong commercial banks Counter-cyclical provisioning, capital management hypothesis apply and Efficiency is an important determinant of loan loss provisions in Hong Kong