A Parameterized multi-step Newton method for solving systems of nonlinear equations

We construct a novel multi-step iterative method for solving systems of nonlinear equations by introducing a parameter. to generalize the multi-step Newton method while keeping its order of convergence and computational cost. By an appropriate selection of theta, the new method can both have faster convergence and have larger radius of convergence. The new iterative method only requires one Jacobian inversion per iteration, and therefore, can be efficiently implemented using Krylov subspace methods. The new method can be used to solve nonlinear systems of partial differential equations, such as complex generalized Zakharov systems of partial differential equations, by transforming them into systems of nonlinear equations by discretizing approaches in both spatial and temporal independent variables such as, for instance, the Chebyshev pseudo-spectral discretizing method. Quite extensive tests show that the new method can have significantly faster convergence and significantly larger radius of convergence than the multi-step Newton method.Peer ReviewedPostprint (author's final draft

SiC power MOSFETs performance, robustness and technology maturity

Relatively recently, SiC power MOSFETs have transitioned from being a research exercise to becoming an industrial reality. The potential benefits that can be drawn from this technology in the electrical energy conversion domain have been amply discussed and partly demonstrated. Before their widespread use in the field, the transistors need to be thoroughly investigated and later validated for robustness and longer term stability and reliability. This paper proposes a review of commercial SiC power MOSFETs state-of-the-art characteristics and discusses trends and needs for further technology improvements, as well as device design and engineering advancements to meet the increasing demands of power electronics

Long-term outcomes of a randomized clinical trial of supervised exercise, percutaneous transluminal angioplasty or combined treatment for patients with intermittent claudication due to femoropopliteal disease

Background: To compare the long-term outcomes of angioplasty (PTA), supervised exercise (SEP) and combined treatment (PTA+SEP) in patients with intermittent claudication (IC) due to femoropopliteal disease. Methods: Patients recruited to PTA, SEP and PTA+SEP arms of RCT were invited for long-term follow-up from 2010 to 2011.Indicators of limb ischaemia were recorded (ankle-brachial pressure indices, treadmill walking distances (ICD, MWD, PRWD). Duplex ultrasound was also performed. Patients completed SF36 and Vascuqol quality of life(QOL) questionnaires. Results: Of the 178 patients recruited in the trial, 139 were alive at the time of follow-up (PTA=46, SEP=47, PTA+SEP=46). Assessments were completed for 111 patients. Median time to follow-up was 5.2years (IQR 3.8-7.4years). Median age of patients at follow up was 75years. 62.2%(N=69) of patients were symptomatic.16.2%(N= 18) had experienced major cardiovascular event since their last follow-up visit. Intra-group analysis: Improvement was observed in ankle brachial pressure index (ABPI) in all groups. QOL outcomes were inconsistent across individual groups. Inter-group analysis: PTA and PTA+SEP groups demonstrated a significantly higher ABPI as compared to SEP group. No significant difference was observed in walking distances, QOL outcomes, restenosis rates, and new ipsilateral and contralateral lesions on duplex scan. Patients required re-interventions in all group (PTA=14, SEP=10, PTA+SEP=6). Number of re-interventions was higher in PTA group(N=29) as compared to SEP(N=17) and PTA+SEP(N=9) but failed to reach statistical significance. Conclusion: PTA, SEP and combined treatment are equally effective long-term treatment options for patients with femoropopliteal claudication. Addition of SEP to PTA can reduce the symptomatic restenosis and re-intervention rates

Percutaneous transluminal angioplasty results in improved physical function but not balance in patients with intermittent claudication

Objective The aim of this study was to identify whether revascularization by percutaneous transluminal angioplasty (PTA) for patients with intermittent claudication improved measures of functional performance including balance. Methods A prospective observational study was performed at a single tertiary vascular center. Patients with symptomatic intermittent claudication (Rutherford grades 1-3) were recruited to the study. Participants were assessed at baseline (pre-PTA) and then 3, 6, and 12 months post-PTA for markers of (1) lower limb ischemia (treadmill walking distances and ankle-brachial pressure index), (2) physical function (6-minute walk, Timed Up and Go, and chair stand time), (3) balance impairment using computerized dynamic posturography with the Sensory Organization Test, and (4) quality of life (VascuQoL and Short Form Health Survey [SF-36]). Results Forty-three participants underwent PTA. Over 12 months, a significant improvement was demonstrated in initial (P = .04) and maximum treadmill walking distance (P = .019). Physical functional ability improved across all outcome measures (P < .02), and some domains of both generic (P < .03) and disease-specific quality of life (P < .01). No significant improvement in balance was demonstrated by the Sensory Organization Test (P = .24). Conclusions Balance impairment is common in claudicants and does not improve with revascularization. Further research regarding effective treatment of balance impairment is required in this specific group of patients

Avalanche ruggedness of parallel SiC power MOSFETs

© 2018 Elsevier Ltd The aim of this paper is to investigate the impact of electro-thermal device parameter spread on the avalanche ruggedness of parallel silicon carbide (SiC) power MOSFETs representative of multi-chip layout within an integrated power module. The tests were conducted on second generation 1200 V, 36 A–80 mΩ rated devices. Different temperature-dependent electrical parameters were identified and measured for a number of devices. The influence of spread in measured parameters was investigated experimentally during avalanche breakdown transient switching events and important findings have been highlighted

The Inflammasome: First Line of the Immune Response to Cell Stress

The NALP3-inflammasome is a protein complex that stimulates caspase-1 activation to promote the processing and secretion of proinflammatory cytokines. Recent work indicates that the NALP3-inflammasome can be activated by endogenous “danger signals” as well as compounds associated with pathogens (Kanneganti et al., 2006; Mariathasan et al., 2006; Martinon et al., 2006; Sutterwala et al., 2006). Here, we discuss new insights into the regulation of caspase-1 activity in the inflammatory response

Protein binding affinity prediction using support vector regression and interfecial features

In understanding biology at the molecular level, analysis of protein interactions and protein binding affinity is a challenge. It is an important problem in computational and structural biology. Experimental measurement of binding affinity in the wet-lab is expensive and time consuming. Therefore, machine learning approaches are widely used to predict protein interactions and binding affinities by learning from specific properties of existing complexes. In this work, we propose an innovative computational model to predict binding affinities and interaction based on sequence, structural and interface features of the interacting proteins that are robust to binding associated conformational changes. We modeled the prediction of binding affinity as classification and regression problem with least-squared and support vector regression models using structure and sequence features of proteins. Specifically, we have used the number and composition of interacting residues at protein complexes interface as features and sequence features. We evaluated the performance of our prediction models using Affinity Benchmark Dataset version 2.0 which contains a diverse set of both bound and unbound protein complex structures with known binding affinities. We evaluated our regression performance results with root mean square error (RMSE) as well as Spearman and Pearson's correlation coefficients using a leave-one-out cross-validation protocol. We evaluate classification results with AUC-ROC and AUC-PR Our results show that Support Vector Regression performs significantly better than other models with a Spearman Correlation coefficient of 0.58, Pearson Correlation score of 0.55 and RMSE of 2.41 using 3-mer and sequence feature. It is interesting to note that simple features based on 3-mer features and the properties of the interface of a protein complex are predictive of its binding affinity. These features, together with support vector regression achieve higher accuracy than existing sequence based methods

Credit Risk Oracle: The Bifocal Approach

This study aims to examine the macroeconomic and bank specific predictors of Credit Risk (NPL) and their relevant degree of impact on banks in Pakistan. For bank variables a sample of big 10 banks has been taken from 2009 to 2018. For macro-economic variables sample of 2009 to 2018 has been taken from the world bank. As financial institutions play their role to support industries and alleviate poverty in a country, this study checks the effect of banking variables as well as the economic variables on the credit risk of banks by taking industrial sector growth as a moderator. The study found that NPLs are negatively associated with Lending interest rate, Bank investment, Capital adequacy ratio, Domestic credit to private sector, Financial depth and GDP growth while positively associated with Lending capability, Return on equity, Interest spread and Liquidity Ratio. The moderation effect of Industrial sector growth on the relationship of Lending Capability and NPLs is found to be strengthening the relationship