1,918 research outputs found
ELECTROCHEMICAL ANALYSIS SUPPORTED BY MACRO AND MICROELECTRODE ARRAY
No full textThe purpose of this project was to investigate cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analytical techniques for enantioselective sensing at both a macroelectrode and a microelectrode array. The scale of the electrochemical cell was reduced from macro to micro dimensions to improve both the electroanalytical detection and the efficient use of chemicals. A microdevice was fabricated using photolithography and plasma bonding and consisting of a microelectrode array (MEA) of 306 microelectrodes, each with a diameter of 45 µm supported by a polydimethylsiloxane (PDMS) slab engraved with microfluidic channels. The electroanalytical performances of the microdevice were characterised using cyclic voltammetry and it was established that the metallisation process influenced the surface roughness of the electrode, and also affected the final response of the array. The microdevice was used for flow injection analysis using chronoamperometry and provided the capability to detect small changes of analyte concentration. The selective electro-oxidation of phenylethanol catalysed by TEMPO and (-)-sparteine at a macroelectrode and MEA was investigated. The CV analysis showed a reproducible selective oxidation in favour of the (-)-phenylethanol enantiomer. The performances of the electrodes were enhanced to improve their enantioselective capability, and to extend their application to biosensors by functionalising their surface with Self-Assembled Monolayers (SAM). The electrodes were modified with glutathione and cysteine chiral molecules to investigate their ability to recognise the proline enantiomers using EIS analysis. The electron transfer rate of the ferricyanide analyte at the cysteine monolayer was less in the presence of D proline than it was in the presence of L-proline, indicating the selective penetration of the enantiomer through the monolayer. The properties of the macroelectrode and MEA were extended to biological applications by modifying their surfaces with thiolated single stranded DNA
Software Metrics to Improve Software Quality in HEP
No full textThe ALEPH reconstruction program maintainability has been evaluated with a case tool implementing an ISO standard methodology based on software metrics. It has been found that the overall quality of the program is good and has shown improvement over the past five years. Frequently modified routines exhibit lower quality; most bugs were located in routines with particularly low quality. Implementing from the beginning a quality criteria could have avoided time losses due to bug corrections. 1 Introduction 1.1 What is a software metric? Software metrics refer to measurement criteria for computer software 1 . They are primarily used to define quality and productivity measurements. Two types of measurements exists. Direct measurements which are concerned with size and speed and indirect measurements which evaluate complexity, maintainability or quality. Software metrics are generally applied in large "professional " software projects 2 . 1.2 General framework Large and long life c..
Magnetic structure and magnon dynamics of the quasi-two-dimensional antiferromagnet FePS3
No full textNeutron scattering from single crystals has been used to determine the magnetic structure and magnon dynamics of FePS3, an S = 2 Ising-like quasi-two-dimensional antiferromagnet with a honeycomb lattice. The magnetic structure has been confirmed to have a magnetic propagation vector of k(M) = [01 1/2] and the moments are collinear with the normal to the ab planes. The magnon data could be modeled using a Heisenberg Hamiltonian with a single-ion anisotropy. Magnetic interactions up to the third in-plane nearest neighbor needed to be included for a suitable fit. The best fit parameters for the in-plane exchange interactions were J(1) = 1.46, J(2) = -0.04, and J(3) = -0.96 meV. The single-ion anisotropy is large, Delta = 2.66 meV, explaining the Ising-like behavior of the magnetism in the compound. The interlayer exchange is very small, J' = -0.0073 meV, proving that FePS3 is a very good approximation to a two-dimensional magnet.LQ
Preparing ATLAS Distributed Computing for LHC Run 2
No full textATLAS software and computing is in a period of intensive evolution. The current long shutdown presents an opportunity to assimilate lessons from the very successful Run 1 (2009-2013) and to prepare for the substantially increased computing requirements for Run 2 (from spring 2015). Run 2 will bring a near doubling of the energy and the data rate, high event pile-up levels, and higher event complexity from detector upgrades, meaning the number and complexity of events to be analyzed will increase dramatically. At the same time operational loads must be reduced through greater automation, a wider array of opportunistic resources must be supported, costly storage must be used with greater efficiency, a sophisticated new analysis model must be integrated, and concurrency features of new processors must be exploited. This presentation will survey the distributed computing aspects of the upgrade program and the plans for 2014 to exercise the new capabilities in a large scale Data Challenge
Antipsychotics and Torsadogenic Risk: Signals Emerging from the US FDA Adverse Event Reporting System Database
No full textBackground: Drug-induced torsades de pointes (TdP) and related clinical entities represent a current regulatory and clinical burden. Objective: As part of the FP7 ARITMO (Arrhythmogenic Potential of Drugs) project, we explored the publicly available US FDA Adverse Event Reporting System (FAERS) database to detect signals of torsadogenicity for antipsychotics (APs). Methods: Four groups of events in decreasing order of drug-attributable risk were identified: (1) TdP, (2) QT-interval abnormalities, (3) ventricular fibrillation/tachycardia, and (4) sudden cardiac death. The reporting odds ratio (ROR) with 95 % confidence interval (CI) was calculated through a cumulative analysis from group 1 to 4. For groups 1+2, ROR was adjusted for age, gender, and concomitant drugs (e.g., antiarrhythmics) and stratified for AZCERT drugs, lists I and II (http://www.azcert.org, as of June 2011). A potential signal of torsadogenicity was defined if a drug met all the following criteria: (a) four or more cases in group 1+2; (b) significant ROR in group 1+2 that persists through the cumulative approach; (c) significant adjusted ROR for group 1+2 in the stratum without AZCERT drugs; (d) not included in AZCERT lists (as of June 2011). Results: Over the 7-year period, 37 APs were reported in 4,794 cases of arrhythmia: 140 (group 1), 883 (group 2), 1,651 (group 3), and 2,120 (group 4). Based on our criteria, the following potential signals of torsadogenicity were found: amisulpride (25 cases; adjusted ROR in the stratum without AZCERT drugs = 43.94, 95 % CI 22.82-84.60), cyamemazine (11; 15.48, 6.87-34.91), and olanzapine (189; 7.74, 6.45-9.30). Conclusions: This pharmacovigilance analysis on the FAERS found 3 potential signals of torsadogenicity for drugs previously unknown for this risk
Etude comparative des systèmes de compression de données sans perte d'information et codage arithmétique
No full textLes approches classiques de la compression de données sans perte d'information sont basées sur un découplage de la modélisation de la source et du codage. La modélisation statistique avec codage par la méthode d'Huffman est la combinaison la plus utilisée. On considère alors soit un modèle fixe ( ce qui a l'avantage d'un codage simple passe mais qui ne peut être efficace pour des sources de types variés ), soit un modèle adapté à chaque fichier mais qui nécessite une "double passe". L'algorithme "simple passe" de fragmentation croissante de Ziv-Lempel permet d'obtenir des taux de compression importants. Cependant, cet algorithme n'est efficace que pour de gros fichiers corrélés sur une seule dimension. Afin de pallier ces divers inconvénients, l'algorithme "du contexte" permettant une modélisation markovienne adaptative de la source a été présenté par Rissanen en 1983. Avec sa modélisation en arbre et une gestion originale du modèle basée sur le principe de la longueur de description minimale, cet algorithme peut s'appliquer à des sources corrélées sur plusieurs dimensions, telles que les images. La partie codage est assurée par un code arithmétique multi-niveaux sans multiplication, qui a l'avantage, par rapport aux codes "préfix", de retrouver parfaitement l'entropie quelque soit la statistique et d'être parfaitement adaptatif en cas de modification du modèle. L'article est organisé en trois parties : nous commençons par rappeler les diverses méthodes de compression de données sans perte d'information, puis nous décrivons l'algorithme du contexte, et nous rapportons une évaluation comparative des performances pour divers types de fichiers. Enfin, une application au codage en sous-bande de signaux video est mentionnée
An integrated transportation land use modeling system
No full textThe principle objective of this research is to develop an integrated land-use/transportation model to represent the interrelationships between land use and transportation, subject to the requirements of the ISTEA of 1991 and the CAAA of 1990. The integrated model includes two major parts: a land-use allocation module and a travel demand module. Interface modules have also been built to transform data between these two modules. The land-use allocation module consists of a residential location model, an employment location model, a land use potential model, and a land consumption model. One unique feature of the residential and employment location models is that they simultaneously estimate passenger movement by work-to-home, home-to-shop and work-to-shop trips between zones before entering the travel demand module. Then the TRANPLAN-based travel demand module carries out trip generation and trip distribution stages for estimating home-based school, home-based other, non-home-based, external-internal and external-external trips. The land consumption model, which is significantly different from the LANCON procedure of DRAM/EMPAL, based on micro-economic theory can simulate the profit-maximizing behavior of housing or land owners over time. The major purpose of the land consumption model is to satisfy the need to reach a balance between demand and supply in the housing market during each time period. The land consumption model is also influenced by Anas\u27s work in CATLAS, which did not deal with employment location, and simultaneously considers housing location and employment location. The integrated model can be used to evaluate land use policies and transportation policies. Tests run for the Lafayette area have demonstrated that the model can be used to quantify positive and negative effects of long range transportation and land use plans
TEM observations on the behavior of facet junctions in interfaces and inclusions
No full textExperimental Nanophysic
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