High Responsiveness for Group Editing CRDTs

International audienceGroup editing is a crucial feature for many end-user applications. It requires high responsiveness, which can be provided only by optimistic replication algorithms, which come in two classes: classical Operational Transformation (OT), or more recent Conflict-Free Replicated Data Types (CRDTs). Typically, CRDTs perform better on downstream operations , i.e., when merging concurrent operations than OT, because the former have logarithmic complexity and the latter quadratic. However, CRDTs are often less responsive, because their upstream complexity is linear. To improve this, this paper proposes to interpose an auxiliary data structure , called the identifier data structure in front of the base CRDT. The identifier structure ensures logarithmic complexity and does not require replication or synchronization. Combined with a block-wise storage approach, this approach improves upstream execution time by several orders of magnitude , with negligeable impact on memory occupation, network bandwidth, and downstream execution performance

A multilaboratory, multicountry study to determine MIC quality control ranges for phenotypic drug susceptibility testing of selected first-line antituberculosis dugs, second-line injectables, fluoroquinolones, clofazimine, and linezolid

OBJECTIVES : Our objective was to establish reference minimal inhibitory concentration (MIC) quality control (QC) ranges for drug susceptibility testing of antimycobacterials, including firstline agents, second-line injectables, fluoroquinolones and World Health Organization Category 5 drugs for multidrug-resistant tuberculosis, using a 7H9 broth microdilution MIC method. METHODS : A Tier-2 reproducibility study was conducted in eight participating laboratories using Clinical Laboratory and Standards Institute (CLSI) guidelines. Three lots of custom-made frozen 96-well polystyrene micro titer plates were used and pre-prepared with 2X pre-diluted drugs in 7H9 broth/oleic acid albumin dextrose catalase. The QC reference strain was Mycobacterium tuberculosis (MTB) H37Rv. MIC frequency, mode and geometric mean were calculated for each drug. QC ranges were derived, based on predefined, strict CLSI criteria. Any data lying outside CLSI criteria resulted in exclusion of the entire laboratory dataset. RESULTS : Data from one laboratory were excluded due to higher MIC values than for other laboratories. QC ranges were established for eleven drugs: isoniazid (0.03–0.12 μg/ml), rifampin (0.03–0.25 μg/ml), ethambutol (0.25–2 μg/ml), levofloxacin (0.12–1 μg/ml), moxifloxacin (0.06–0.5 μg/ml), ofloxacin (0.25–2 μg/ml), amikacin (0.25–2 μg/ml), kanamycin (0.25–2 μg/ml), capreomycin (0.5–4 μg/ml), linezolid (0.25–2 μg/ml) and clofazimine (0.03–0.25 μg/ml). QC ranges could not be established for nicotinamide (pyrazinamide surrogate), prothionamide or ethionamide, which were assay non-performers. CONCLUSIONS : Using strict CLSI criteria, QC ranges against the MTB H37Rv reference strain were established for the majority of commonly used antituberculosis drugs, with a convenient 7H9 broth microdilution MIC method suitable for use in resource-limited settings.All participating laboratories received funds for this study from Janssen Pharmaceuticals except the Reference Laboratory, Division of TB Elimination, United States Centers for Disease Control and Prevention, Atlanta, GA, USA. Support for medical writing assistance was provided by Janssen Pharmaceuticals.http://jcm.asm.org2017-06-30hb2017Medical Microbiolog

A multilaboratory, multicountry study to determine bedaquiline MIC quality control ranges for phenotypic drug susceptibility testing

The aim of this study was to establish standardized drug susceptibility testing (DST) methodologies and reference MIC quality control (QC) ranges for bedaquiline, a diarylquinoline antimycobacterial, used in the treatment of adults with multidrug-resistant tuberculosis. Two tier-2 QC reproducibility studies of bedaquiline DST were conducted in eight laboratories using Clinical Laboratory and Standards Institute (CLSI) guidelines. Agar dilution and broth microdilution methods were evaluated. Mycobacterium tuberculosis H37Rv was used as the QC reference strain. Bedaquiline MIC frequency, mode, and geometric mean were calculated. When resulting data occurred outside predefined CLSI criteria, the entire laboratory data set was excluded. For the agar dilution MIC, a 4-dilution QC range (0.015 to 0.12 μg/ml) centered around the geometric mean included 95.8% (7H10 agar dilution; 204/213 observations with one data set excluded) or 95.9% (7H11 agar dilution; 232/242) of bedaquiline MICs. For the 7H9 broth microdilution MIC, a 3-dilution QC range (0.015 to 0.06 μg/ml) centered around the mode included 98.1% (207/211, with one data set excluded) of bedaquiline MICs. Microbiological equivalence was demonstrated for bedaquiline MICs determined using 7H10 agar and 7H11 agar but not for bedaquiline MICs determined using 7H9 broth and 7H10 agar or 7H9 broth and 7H11 agar. Bedaquiline DST methodologies and MIC QC ranges against the H37Rv M. tuberculosis reference strain have been established: 0.015 to 0.12 μg/ml for the 7H10 and 7H11 agar dilution MICs and 0.015 to 0.06 μg/ml for the 7H9 broth microdilution MIC. These methodologies and QC ranges will be submitted to CLSI and EUCAST to inform future research and provide guidance for routine clinical bedaquiline DST in laboratories worldwide.All participating laboratories received funds for this study from Janssen Pharmaceuticals except the Reference Laboratory, Division of TB Elimination, United States Centers for Disease Control and Prevention, Atlanta, GA, USA. Support for medical writing assistance was provided by Janssen Pharmaceuticals.http://jcm.asm.orghj2017Medical Microbiolog

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

SCHEMA EVOLUTION IN SOFTWARE ENGINEERING DATABASES --- A NEW APPROACH IN ADELE ENVIRONMENT

This paper discusses schema evolution in software engineering databases. After a study of existing approaches, we show that these approaches do not satisfy software engineering requirements. Then, we present our model, which supports multiple schema compositions and multiple evolution policies, each application being free to define its evolution strategy. Management of our system is based on class versioning. The consistency of the database and the various evolution policies are controlled by consistency constraints. The schema composition uses software configuration techniques and evolution policy definition uses the capability of the active database of the Adele system

Un modèle de composition des services web sémantiques

International audienceThe work presented here aims to provide a composition model of semantic web services. This model is based on a semantic representation of domain concepts handled by web services, namely, operations and the static concepts used to describe static properties of Web services. Different levels of abstraction are given to the concept of operation to allow gradual access to concret services. Thus, two different levels of the composition plan are generated (abstract and concret). This will reuse plans already constructed to meet similar needs even with modified preferences.Le travail présenté ici vise à proposer un modèle pour la composition des services web sémantiques. Ce modèle est basé sur une représentation sémantique de l'ensemble des concepts manipulés par les services web d’un domaine d'application, à savoir, les opérations et les concepts statiques utilisés pour décrire les propriétés des services web. Différents niveaux d'abstraction sont donnés au concept opération pour permettre un accès progressif aux services concrets. Ainsi, deux plans de composition à granularités différentes (abstrait et concrets) sont générés. Ceci permettrade réutiliser des plans déjà construits pour répondre à des besoins similaires et même avec despréférences modifiées

Biogeography-based optimization for software module clustering

International audienceno abstrac

A survey on search-based model-driven engineering

International audienceModel-driven engineering (MDE) and search-based software engineering (SBSE) are both relevant approaches to software engineering. MDE aims to raise the level of abstraction in order to cope with the complexity of software systems, while SBSE involves the application of metaheuristic search techniques to complex software engineering problems, reformulating engineering tasks as optimization problems. The purpose of this paper is to survey the relatively recent research activity lying at the interface between these two fields, an area that has come to be known as search-based model-driven engineering. We begin with an introduction to MDE, the concepts of models, of metamodels and of model transformations. We also give a brief introduction to SBSE and metaheuristics. Then, we survey the current research work centered around the combination of search-based techniques and MDE. The literature survey is accompanied by the presentation of references for further details

Un modèle de composition des services web sémantiques

The work presented here aims to provide a composition model of semantic web services. This model is based on a semantic representation of domain concepts handled by web services, namely, operations and the static concepts used to describe static properties of Web services. Different levels of abstraction are given to the concept of operation to allow gradual access to concret services. Thus, two different levels of the composition plan are generated (abstract and concret). This will reuse plans already constructed to meet similar needs even with modified preferences.Le travail présenté ici vise à proposer un modèle pour la composition des services web sémantiques. Ce modèle est basé sur une représentation sémantique de l'ensemble des concepts manipulés par les services web d’un domaine d'application, à savoir, les opérations et les concepts statiques utilisés pour décrire les propriétés des services web. Différents niveaux d'abstraction sont donnés au concept opération pour permettre un accès progressif aux services concrets. Ainsi, deux plans de composition à granularités différentes (abstrait et concrets) sont générés. Ceci permettrade réutiliser des plans déjà construits pour répondre à des besoins similaires et même avec despréférences modifiées