Satisfying quality requirements in the design of a partition‐based,distributed stock trading system

Although quality requirements (QRs) have become a major drive in today's software development, there have been very few real‐world examples in the literature that demonstrate how to meet these requirements. This paper presents such an example. Specifically, the paper describes the design of a partition‐based distributed stock trading service system that satisfies a set of QRs related to resource utilization, performance, scalability and availability. The paper evaluates this design through detailed experiments and discusses some design alternatives and the lessons learned. Central to this design are a static load distribution strategy and a dynamic load balancing strategy. The first strategy is to achieve an initial balanced workload on the system's server cluster during the system initialization time, whereas the second strategy is to maintain this balanced workload throughout the system execution time. Together, these two strategies work in unison to ensure that the server resources are efficiently utilized; the user requests are processed with the required speed; the application is partitioned with sufficient room to scale; and the system is highly available. Copyright © 2011 John Wiley & Sons, Ltd.     

Preparation of Pb(Ti,Zr)O3/RuO2 multilayers in situ by pulsed laser ablation deposition

Abstract

RuO₂/PbZr_0.52Ti_0.48O₃ multilayers have been prepared by pulsed laser deposition and characterised by Grazing Incident Angle Bragg Diffraction and scanning electron microscopy. The results are correlated with the different deposition conditions and post-growth thermal annealing. The structure of the paraelectric pyrochlore phase (Pb₂(Zr,Ti)₂O₆) and its stability relative to the ferroelectric perovskite is discussed.     

The CLOCK trial,a double‐blinded randomized controlled trial: Trisodium citrate 30% and minocycline 3 mg/mL plus EDTA 30 mg/mL are effective and safe for catheter patency maintenance among CKD 5D patients on hemodialysis

Introduction: Poor blood flow rate (PF) is highly prevalent among CKD 5D patients with long‐term central venous catheters. Heparin catheter lock solutions are commonly used to maintain catheter patency, however the incidence of PF remains high. The purpose of the CLOCK Trial was to evaluate two catheter lock solutions on reduction of PF incidence. Methods: Seventy‐five CKD 5D patients on high‐efficiency hemodialysis at the Integrated Centre of Nephrology (Guarulhos, Brazil) were randomized 1:1:1 to receive a lock solution combining minocycline 3 mg/mL with the anticoagulant/chelation agent EDTA 30 mg/mL (M‐EDTA) or heparin 1000 IU/mL (H) or trisodium citrate 30% (TSC) vs. Hfor 15 weeks. A total of 68 patients completed the trial in which both investigators and patients were blinded to treatment allocation. The primary end‐point was the occurrence of hydraulic resistance and secondary safety end‐point was adverse drug reactions related to the lock solutions. Findings: At the beginning of the trial, 7 patients were excluded from this trial due to their poor catheter care. The incidence of hydraulic resistance was significantly higher among patients on H (18/23) compared to TSC (4/22) and M‐EDTA (2/23) lock solutions, (P < 0.001). Discussion: The CLOCK Trial suggests TSC and M‐EDTA may preserve catheter patency better than H. TSC may be a better option due the lack of association with long‐term antimicrobial resistance.     

Assessment of the Effects of Dietary Vitamin D Levels on Olanzapine-Induced Metabolic Side Effects: Focus on the Endocannabinoidome-Gut Microbiome Axis

Vitamin D deficiency is associated with poor mental health and dysmetabolism. Several metabolic abnormalities are associated with psychotic diseases, which can be compounded by atypical antipsychotics that induce weight gain and insulin resistance. These side-effects may be affected by vitamin D levels. The gut microbiota and endocannabinoidome (eCBome) are significant regulators of both metabolism and mental health, but their role in the development of atypical antipsychotic drug metabolic side-effects and their interaction with vitamin D status is unknown. We studied the effects of different combinations of vitamin D levels and atypical antipsychotic drug (olanzapine) exposure on whole-body metabolism and the eCBome-gut microbiota axis in female C57BL/6J mice under a high fat/high sucrose (HFHS) diet in an attempt to identify a link between the latter and the different metabolic outputs induced by the treatments. Olanzapine exerted a protective effect against diet-induced obesity and insulin resistance, largely independent of dietary vitamin D status. These changes were concomitant with olanzapine-mediated decreases in Trpv1 expression and increases in the levels of its agonists, including various N-acylethanolamines and 2-monoacylglycerols, which are consistent with the observed improvement in adiposity and metabolic status. Furthermore, while global gut bacteria community architecture was not altered by olanzapine, we identified changes in the relative abundances of various commensal bacterial families. Taken together, changes of eCBome and gut microbiota families under our experimental conditions might contribute to olanzapine and vitamin D-mediated inhibition of weight gain in mice on a HFHS diet.     

Immune Response Modifications in the Genetic Forms of Parkinson’s Disease: What Do We Know?

Parkinson’s disease (PD) is a common neurodegenerative disease characterized by loss of dopaminergic neurons in the pars compacta of the midbrain substantia nigra. PD pathophysiology is complex, multifactorial, and not fully understood yet. Nonetheless, recent data show that immune system hyperactivation with concomitant production of pro-inflammatory cytokines, both in the central nervous system (CNS) and the periphery, is a signature of idiopathic PD. About 5% of PD patients present an early onset with a determined genetic cause, with either autosomal dominant or recessive inheritance. The involvement of immunity in the genetic forms of PD has been a matter of interest in several recent studies. In this review, we will summarize the main findings of this new and promising field of research     

Polymorphisms of Dopamine Receptor Genes and Parkinson’s Disease: Clinical Relevance and Future Perspectives

Parkinson’s disease (PD) is a neurodegenerative disease caused by loss of dopaminergic neurons in the midbrain. PD is clinically characterized by a variety of motor and nonmotor symptoms, and treatment relies on dopaminergic replacement. Beyond a common pathological hallmark, PD patients may present differences in both clinical progression and response to drug therapy that are partly affected by genetic factors. Despite extensive knowledge on genetic variability of dopaminergic receptors (DR), few studies have addressed their relevance as possible influencers of clinical heterogeneity in PD patients. In this review, we summarized available evidence regarding the role of genetic polymorphisms in DR as possible determinants of PD development, progression and treatment response. Moreover, we examined the role of DR in the modulation of peripheral immunity, in light of the emerging role of the peripheral immune system in PD pathophysiology. A better understanding of all these aspects represents an important step towards the development of precise and personalized disease-modifying therapies for PD.     

Development and characterization of a modular acquisition system for a 4D PET block detector

Next generation PET scanners should fulfill very high requirements in terms of spatial, energy and timing resolution. Modern scanner performances are inherently limited by the use of standard photomultiplier tubes. The use of Silicon Photomultiplier (SiPM) matrices is proposed for the construction of a 4D PET module based on LSO continuous crystals, which is envisaged to replace the standard PET block detector. The expected spatial resolution of the module for the photon hit position is below 1 mm, and it will perform at the same time, the Depth Of Interaction (DOI) calculation and the Time Of Flight (TOF) measurement. The use of large area multi-pixel Silicon Photomultiplier (SiPM) detectors requires the development of a multichannel Digital Acquisition system (DAQ) as well as of a dedicated front-end in order not to degrade the intrinsic detector performances. We have developed a flexible and modular DAQ system for the read-out of two modules in time coincidence for Positron Emission Tomography (PET) applications. The DAQ system is based on a previously developed custom front-end ASIC chip (BASIC) which allows to read-out SiPM matrices preserving their spectroscopy and timing capabilities. Here we describe the acquisition system architecture and its characterization measurements.     

Tuning of High-Speed Telecommunication Filters, via I/O Cross-Correlation Evaluation

Continuous-time (CT) filters are widely used in signal processing but, owing to the large spread in the process parameters which determine their time constants, they require a tuning system to align their frequency characteristics. Several techniques have already been proposed in the literature and are commonly employed, but usually they require either a doubling of the filter circuitry or some complex self-calibration scheme, resulting in sensible area overhead or high computational complexity. Here, we present a novel tuning approach which can be applied to both master-slave and self-calibration arrangements and is based on the evaluation of a few samples of the input-output cross-correlation function of the filter, when the input signal is a finite length sequence of pseudorandom pulses. The key advantages of the proposed technique are basically the ease of generation of the input bit-stream and the simplicity of the circuitry required to sample the filter output and to perform the cross-correlation operation. As a consequence, the area overhead associated to the tuning circuitry is kept very small. Some simulation results of the application to the tuning of a low-Q telecommunication filter are given and an extension to the tuning of high-Q active filters is also explored in order to assess the effectiveness and robustness of the proposed technique     

轻型竹木复合墙体的热工性能试验研究

为研究轻型竹墙的热工性能,促进推广此类新型轻质墙材在节能建筑中的应用,设计并制作了2片轻型竹墙、1片轻型木墙以及1片轻型竹木复合墙,并进行了墙体的防护热箱试验,实测获取了墙体的热阻和传热系数。结合已有文献中轻钢龙骨墙体的热工性能的试验研究结果,对轻型竹墙、轻型木墙以及竹木复合墙体等的热工性能进行了比较研究。根据ISO 6946:2007的平均传热系数计算方法对轻型竹墙、轻型木墙以及轻型竹木复合墙体的稳态传热性能进行了计算和有限元分析,验证了有限元分析的可行性。基于有限元模型分别以材料的导热系数、龙骨间距、龙骨厚度及墙内钉间距为参数对3种轻型竹木墙体的热工性能进行了模拟分析。结果表明：轻钢龙骨墙体的传热系数最大,轻型竹墙与木墙的传热系数相近,说明以竹代木的设计理念是可行的;龙骨材料的导热系数垂直积层方向变化对墙体的热工性能影响较大;增加龙骨间距可适当减小墙体的传热系数,而增大龙骨厚度则可大幅减小墙体的传热系数;墙体热工性能受墙内钉间距影响较小,钉间距超过150mm时可忽略其影响。