Some rare presentations of hydatid cysts: two case reports

Hydatid disease is a considerable health problem worldwide. Two case reports of relatively uncommon presentations of the disease are presented

Paradoxical Association of Smoking With In‐Hospital Mortality Among Patients Admitted With Acute Ischemic Stroke

Background: Compared to those who never smoked, a paradoxical effect of smoking on reducing mortality in patients admitted with myocardial ischemia has been reported. We sought to determine if this effect was present in patients hospitalized with ischemic stroke. Methods and Results: Using the local Get with the Guidelines‐Stroke registry, we analyzed 4305 consecutively admitted ischemic stroke patients (March 2002–December 2011). The sample was divided into smokers versus nonsmokers. The main outcome of interest was the overall inpatient mortality. Compared to nonsmokers, tobacco smokers were younger, more frequently male and presented with fewer stroke risk factors such as hypertension, hyperlipidemia, diabetes, coronary artery disease, and atrial fibrillation. Smokers also had a lower average NIH Stroke Scale (NIHSS) and fewer received tissue plasminogen activator (tPA). Patients in both groups had similar adherence to early antithrombotics, dysphagia screening prior to oral intake, and deep vein thrombosis (DVT) prophylaxis. Smoking was associated with lower all‐cause in‐hospital mortality (6.6% versus 12.4%; unadjusted OR 0.46; CI [0.34 to 0.63]; P<0.001). In multivariable analysis, adjusted for age, gender, ethnicity, hypertension, diabetes mellitus, hyperlipidemia, CAD, atrial fibrillation, NIHSS, and tPA, smoking remained independently associated with lower mortality (adjusted OR 0.64; CI [0.42 to 0.96]; P=0.03). Conclusions: Similar to myocardial ischemia, smoking was independently associated with lower inpatient mortality in acute ischemic stroke. This effect may be due to tobacco‐induced changes in cerebrovascular vasoreactivity, or may be due in part to residual confounding. Larger, multicenter studies are needed to confirm the finding and the effect on 30‐day and 1‐year mortality

Characterization of time delay in power hardware in the loop setups

The testing of complex power components by means of power hardware in the loop (PHIL) requires accurate and stable PHIL platforms. The total time delay typically present within these platforms is commonly acknowledged to be an important factor to be considered due to its impact on accuracy and stability. However, a thorough assessment of the total loop delay in PHIL platforms has not been performed in the literature. Therefore, time delay is typically accounted for as a constant parameter. However, with the detailed analysis of the total loop delay performed in this article, variability in time delay has been detected as a result of the interaction between discrete components. Furthermore, a time delay characterization methodology (which includes variability in time delay) has been proposed. This will allow for performing stability analysis with higher precision as well as to perform accurate compensation of these delays. The implications on stability and accuracy that the time delay variability can introduce in PHIL simulations has also been studied. Finally, with an experimental validation procedure, the presence of the variability and the effectiveness of the proposed characterization approach have been demonstrated

Intelligent Fault-Tolerant Mechanism for Data Centers of Cloud Infrastructure

Fault tolerance in cloud computing is considered as one of the most vital issues to deliver reliable services. Checkpoint/restart is one of the methods used to enhance the reliability of the cloud services. However, many existing methods do not focus on virtual machine (VM) failure that occurs due to the higher response time of a node, byzantine fault, and performance fault, and existing methods also ignore the optimization during the recovery phase. This paper proposes a checkpoint/restart mechanism to enhance reliability of cloud services. Our work is threefold: (1) we design an algorithm to identify virtual machine failure due to several faults; (2) an algorithm to optimize the checkpoint interval time is designed; (3) lastly, the asynchronous checkpoint/restart with log-based recovery mechanism is used to restart the failed tasks. The valuation results obtained using a real-time dataset shows that the proposed model reduces power consumption and improves the performance with a better fault tolerance solution compared to the nonoptimization method

Beta-type Ti-Nb-Zr-Cr alloys with large plasticity and significant strain hardening

A series of Ti-25Nb-8Zr-xCr (x = 0, 2, 4, 6, 8 wt%) alloys were designed based on DV-Xα cluster method and e=a-Δr diagram with an anticipation to obtain high plasticity and significant strain hardening. The designed alloys were produced through cold crucible levitation melting technique in order to effectively investigate their micro-structures and mechanical properties. The addition of Cr significantly enhances the β stability in the microstructures of the Ti-25Nb-8Zr-xCr alloys. Both yield strength and hardness of the studied alloys increase due to the effect of solid-solution strengthening. By contrast, the plasticity, maximum strength and strain hardening rate are influenced by theβstability as well as the distinct deformation mechanisms. None of the alloys comprising Cr fail up to 100 kN (the load capacity used) and all show impressive plasticity (~75%) and superior maximum compressive strength (~4.5 GPa) at 100 kN. Moreover, the deformation bands, which are found around the hardness indentations, are analyzed for all the investigated alloys. The fracture behaviors of the Ti-25Nb-8Zr-xCr alloys are also studied to observe the characteristics related to crack propagation, plastic deformation and the formation of shear bands

On Hilbert-Schmidt operator formulation of noncommutative quantum mechanics

This work gives value to the importance of Hilbert-Schmidt operators in the formulation of a noncommutative quantum theory. A system of charged particle in a constant magnetic field is investigated in this framework

Beta Oscillation-Targeted Neurofeedback Training Based on Subthalamic LFPs in Parkinsonian Patients

Increased oscillatory activities in the beta frequency band (13-30 Hz) in the subthalamic nucleus (STN), and in particular prolonged episodes of increased synchrony in this frequency band, have been associated with motor symptoms such as bradykinesia and rigidity in Parkinson's disease (PD). Numerous studies have investigated sensorimotor cortical beta oscillations either as a control signal for Brain Computer Interfaces (BCI) or as target signal for neurofeedback training (NFB). However, it still remains unknown whether patients with PD can gain control of the pathological oscillations recorded from a subcortical site - the STN - with neurofeedback training. We tried to address this question in the current study. Specifically, we designed a simple basketball game, in which the position of a basketball changes based on the occurrence of events of temporally increased beta power quantified in real-time. Participants practised in the game to control the position of the basketball, which requires modulation of the beta oscillations recorded from STN local field potentials (LFPs). Our results suggest that it is possible to use neurofeedback training for PD patients to downregulate pathological beta oscillations in STN LFPs, and that this can lead to a reduction of beta oscillations in the cortical-STN motor network

The performance of robust multivariate Ewma control charts

Multivariate Exponential Weighted Moving Average (MEWMA) control chart is a popular statistical tool for monitoring multivariate process over time. However, this chart is sensitive to the presence of outliers arising from the use of classical mean vector and covariance matrix in estimating the MEWMA statistic. These classical estimators are known to be sensitive to the outliers. To address this problem, robust MEWMA control charts based on modified one-step M-estimator (MOM) and Winsorized modified one-step M-estimator (WM) are proposed. Their performance is then compared with the standard MEWMA control chart in various situations. The findings revealed that the proposed robust MEWMA control charts are more effective in controlling false alarm rates especially for large sample sizes and high percentage of outlier