294 research outputs found

    Benchmarking the Performance of Application Monitoring Systems

    Get PDF
    Application-level monitoring of continuously operating software systems provides insights into their dynamic behavior helping to maintain their performance and availability at runtime. Such monitoring may cause a significant runtime overhead to the monitored system depending on the number and location of used instrumentation probes. In order to improve a system's instrumentation to reduce the caused monitoring overhead, it is necessary to know the performance impact of each probe. In this paper, we present our MooBench approach to split the possible causes of monitoring overhead into three portions, and to quantify these portions of monitoring overhead with the help of benchmarks under controlled and repeatable conditions. To the best of our knowledge, most publications on monitoring frameworks provide none or only weak performance evaluations, making comparisons cumbersome. Our benchmark approach provides a basis for such comparisons

    Protective vaccination in the horse against _Streptococcus equi_ with recombinant antigens

    Get PDF
    _Streptococcus equi_ subspecies _equi_ (_S. equi_) is a clonal, equine host-adapted pathogen of global importance that causes a highly contagious suppurative lymphodendopathy of the head and neck, more commonly known as Strangles. The disease is highly prevalent, can be severe and spread easily by visibly infected animals or by carrier animals that show no clinical signs of disease. Antibiotic treatment is usually ineffective. However, the majority of horses develop immunity to re-infection, suggesting that vaccination should be a feasible way to prevent the infection. Live attenuated vaccine strains of _S. equi_ are available but adverse reactions have been reported and they suffer from a short duration of immunity. Thus, a safe and effective vaccine against _S. equi_ is highly desirable. In this report, Welsh mountain ponies vaccinated with a combination of seven recombinant _S. equi_ proteins, were significantly protected from experimental infection by _S. equi_, resembling the spontaneous disease. The protective antigens consisted of five surface localized proteins and two IgG endopeptidases. The results from a second vaccination trial indicate that the endopeptidases were important for good protection. The similarity of _S. equi_ to other pyogenic streptococci suggests that our findings have broader implications for the prevention of streptococcal infections

    Performance Benchmarking of Application Monitoring Frameworks

    Get PDF
    Application-level monitoring of continuously operating software systems provides insights into their dynamic behavior, helping to maintain their performance and availability during runtime. Such monitoring may cause a significant runtime overhead to the monitored system, depending on the number and location of used instrumentation probes. In order to improve a system’s instrumentation and to reduce the caused monitoring overhead, it is necessary to know the performance impact of each probe. While many monitoring frameworks are claiming to have minimal impact on the performance, these claims are often not backed up with a detailed performance evaluation determining the actual cost of monitoring. Benchmarks can be used as an effective and affordable way for these evaluations. However, no benchmark specifically targeting the overhead of monitoring itself exists. Furthermore, no established benchmark engineering methodology exists that provides guidelines for the design, execution, and analysis of benchmarks. This thesis introduces a benchmark approach to measure the performance overhead of application-level monitoring frameworks. The core contributions of this approach are 1) a definition of common causes of monitoring overhead, 2) a general benchmark engineering methodology, 3) the MooBench micro-benchmark to measure and quantify causes of monitoring overhead, and 4) detailed performance evaluations of three different application-level monitoring frameworks. Extensive experiments demonstrate the feasibility and practicality of the approach and validate the benchmark results. The developed benchmark is available as open source software and the results of all experiments are available for download to facilitate further validation and replication of the results

    Continuous Monitoring of Software Services: Design and Application of the Kieker Framework

    Get PDF
    In addition to studying the construction and evolution of software services, the software engineering discipline needs to address the operation of continuously running software services. A requirement for its robust operation are means for effective monitoring of software runtime behavior. In contrast to profiling for construction activities, monitoring of operational services should only impose a small performance overhead. Furthermore, instrumentation should be non-intrusive to the business logic, as far as possible. We present the Kieker framework for monitoring software runtime behavior, e.g., internal performance or (distributed) trace data. The flexible architecture allows to replace or add framework components, including monitoring probes, analysis components, and monitoring record types shared by logging and analysis. As a non-intrusive instrumentation technique, Kieker currently employs, but is not restricted to, aspect-oriented programming. An extensive lab study evaluates and quantifies the low overhead caused by the framework components. Qualitative evaluations provided by industrial case studies demonstrate the practicality of the approach with a telecommunication customer self service and a digital photo submission service. Kieker is available as open-source software, where both the academic and industrial partners contribute to the code. Our experiment data is publicly available, allowing interested researchers to repeat and extend our lab experiments

    Intramuscular vaccination with Strangvac is safe and induces protection against equine strangles caused by Streptococcus equi

    Get PDF
    The equine disease strangles, caused by Streptococcus equi, remains a major cause of welfare and economic cost to the global horse industry. Here we report the safety, immunogenicity and efficacy of a novel multi-component chimeric fusion protein vaccine, called Strangvac, when administered to ponies via the intramuscular route. Across the four studies, Strangvac was safe and induced robust antibody responses towards the vaccine components in blood serum and the nasopharynx, which were boosted by revaccination up to 12 months after a primary course of 2 vaccinations 4 weeks apart. The vaccine response did not cross-react with a commercial strangles iELISA, which identifies horses that have been exposed to S. equi, demonstrating that it was possible to differentiate infected from vaccinated animals (DIVA). Following challenge with S. equi strain 4047 (Se4047), all 36 control ponies that had received an adjuvant-only placebo vaccine developed clinical signs of strangles. In contrast, intramuscular vaccination with Strangvac protected ponies significantly from challenge with Se4047 at two weeks (5 of 16 ponies protected (31%), P = 0.04) and two months (7 of 12 ponies protected (58%), P = 0.0046 (including pooled control data) after second vaccination. Optimal protection (15 of 16 ponies protected (94%), P < 0.0001) was observed following challenge at two weeks post-third vaccination. Our data demonstrate that Strangvac is safe, has DIVA capability and provides a rapid onset of protective immunity against strangles. We conclude that Strangvac is a valuable tool with which to protect horses from strangles, particularly during high-risk periods, whilst maintaining the mobility of horse populations as required by the global equine industry. (C) 2020 The Authors. Published by Elsevier Ltd

    Building evidence into youth health policy: a case study of the Access 3 knowledge translation forum.

    Get PDF
    BACKGROUND: Effective integration of evidence and youth perspectives into policy is crucial for supporting the future health and well-being of young people. The aim of this project was to translate evidence from the Access 3 project to support development of a new state policy on youth health and well-being within New South Wales (NSW), Australia. Ensuring the active contribution of young people within policy development was a key objective of the knowledge translation (KT) process. METHODS: The KT activity consisted of a 1-day facilitated forum with 64 purposively sampled stakeholders. Participants included eight young people, 14 policy-makers, 15 academics, 22 clinicians or managers from NSW health services, four general practitioners and one mental health service worker. Research to be translated came from the synthesized findings of the NSW Access 3 project. The design of the forum included stakeholder presentations and group workshops, guided by the 2003 Lavis et al. KT framework that was improved by the Grimshaw et al. KT framework in 2012. Members of the Access 3 research team took on the role of knowledge brokers throughout the KT process. Participant satisfaction with the workshop was evaluated using a brief self-report survey. Policy uptake was determined through examination of the subsequent NSW Youth Health Framework 2017-2024. RESULTS: A total of 25 policy recommendations were established through the workshop, and these were grouped into six themes that broadly aligned with the synthesized findings from the Access 3 project. The six policy themes were (1) technology solutions, (2) integrated care and investment to build capacity, (3) adolescent health checks, (4) workforce, (5) youth participation and (6) youth health indicators. Forum members were asked to vote on the importance of individual recommendations. These policy recommendations were subsequently presented to the NSW Ministry of Health, with some evidence of policy uptake identified. The majority of participants rated the forum positively. CONCLUSIONS: The utilization of KT theories and active youth engagement led to the successful translation of research evidence and youth perspectives into NSW youth health policy. Future research should examine the implementation of policy arising from these KT efforts

    Holocene drainage systems of the English Fenland : roddons and their environmental significance

    Get PDF
    The roddons of the English Fenlands are fossilised silt and sand-filled tidal creek systems of mid- to late-Holocene age, incised into contemporaneous clay deposits. However, anthropogenic change (drainage and agriculture) has caused the former channels to become positive topographical features. Three stratigraphically discrete generations of roddon have been discriminated. They all show well-developed dendritic meander patterns, but there is little or no evidence of sand/silt infill during meandering; thus, unlike modern tidal creeks and rivers they typically lack laterally stacked point bar deposits, suggesting rapid infill. Major “trunk” roddons are rich in fine sands and there is little change in grain size from roddon mouth to the upper reaches, suggesting highly effective sand transport mechanisms and uniform conditions of deposition. Tributaries are silt-rich, while minor tributaries also have a significant clay component. During infill, active drainage networks appear to have been choked by sediment, converting mudflat/salt-marsh environments into widespread peat-forming freshwater reed swamps

    Models for Saturation Damage State and Interfacial Shear Strengths in Multilayer Coatings

    Get PDF
    The present work investigates the saturation damage state of a two-layer coating on a substrate (layer 1/layer 2/substrate) under uniaxial tensile loading in order to derive expressions for the interfacial strength between layer 1 and layer 2, and between layer 2 and substrate. It is based on experimental data on specimens where layer 1 is an inorganic film, layer 2 is an organic coating and the substrate is a polymer. The analysis is relevant to the cases where layer 1 cracks first, followed by layer 2, in which cracks appear due to stress concentrations caused by the cracks in layer 1. It considers the cases where at least one interface is completely yielded with shear stress equal to the interfacial shear stress, and where the crack density in layer 1 is equal to or higher than the crack density in layer 2. The possible situations depend on the relative shear strengths between layers 1 and 2 and between layer 2 and the substrate. The interfacial shear strength between layer 1 and layer 2, and between layer 2 and substrate are derived for elastic and yielded stress transfer cases and found to frame experimental values obtained with single-layer coatings
    • …
    corecore