190 research outputs found

    Lymphocyte blastogenesis to plaque antigens in human periodontal disease

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66391/1/j.1600-0765.1977.tb00134.x.pd

    Automatic interface generation for compositional verification

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    Compositional verification, the incremental generation and composition of the state graphs of individual processes to produce the global state graph, tries to address the state explosion problem for systems of communicating processes. The main problem with this approach is that intermediate state graphs are sometimes larger than the overall global system. To overcome this problem, interfaces, and refined interfaces, which take into account a system’s environment have been developed. The number of states of these interfaces plays a vital role in their applicability in terms of computational complexity, which is proportional to the number of states in the interface. The direct use of complete subcomponents of the global system as interfaces, thus usually fails, and it is up to the system designer to describe smaller interfaces to be used in the reduction. To avoid having to verify the correctness of such manually generated interfaces, we propose automatic techniques to generate correct interfaces. The challenge is to produce interfaces small in size, yet effective for reduction. In this paper, we present techniques to structurally produce language over-approximations of labelled transition systems which can be used as correct interfaces, and combine them with refined interfaces. The techniques are applied to a number of case-studies, analysing the trade-off between interface size and effectiveness.peer-reviewe

    Calculating τ-confluence compositionally

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    τ-confluence is a reduction technique used in enumerative model-checking of labeled transition systems to avoid the state explosion problem. In this paper, we propose a new on-the-fly algorithm to calculate partial τ-confluence, and propose new techniques to do so on large systems in a compositional manner. Using information inherent in the way a large system is composed of smaller systems, we show how we can deduce partial τ-confluence in a computationally cheap manner. Finally, these techniques are applied to a number of case studies, including the rel/REL atomic multicast protocol.peer-reviewe

    Fiacre: an Intermediate Language for Model Verification in the Topcased Environment

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    International audienceFiacre was designed in the framework of the TOPCASED project dealing with model-driven engineering and gathering numerous partners, from both industry and academics. Therefore, Fiacre is designed both as the target language of model transformation engines from various models such as SDL, UML, AADL, and as the source language of compilers into the targeted verification toolboxes, namely CADP and Tina in the first step. In this paper, we present the Fiacre language. Then transformations from AADL to Fiacre are illustrated on a small example

    Is CADP an Applicable Formal Method?

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    International audienceCADP is a comprehensive toolbox implementing results of concurrency theory. This paper addresses the question, whether CADP qualifies as an applicable formal method, based on the experience of the authors and feedback reported by users

    Piezoresistive Membrane Surface Stress Sensors for Characterization of Breath Samples of Head and Neck Cancer Patients

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    For many diseases, where a particular organ is affected, chemical by-products can be found in the patient’s exhaled breath. Breath analysis is often done using gas chromatography and mass spectrometry, but interpretation of results is difficult and time-consuming. We performed characterization of patients’ exhaled breath samples by an electronic nose technique based on an array of nanomechanical membrane sensors. Each membrane is coated with a different thin polymer layer. By pumping the exhaled breath into a measurement chamber, volatile organic compounds present in patients’ breath diffuse into the polymer layers and deform the membranes by changes in surface stress. The bending of the membranes is measured piezoresistively and the signals are converted into voltages. The sensor deflection pattern allows one to characterize the condition of the patient. In a clinical pilot study, we investigated breath samples from head and neck cancer patients and healthy control persons. Evaluation using principal component analysis (PCA) allowed a clear distinction between the two groups. As head and neck cancer can be completely removed by surgery, the breath of cured patients was investigated after surgery again and the results were similar to those of the healthy control group, indicating that surgery was successful

    Automatic Detection of Adverse Drug Events in Geriatric Care: Study Proposal

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    BACKGROUND One-third of older inpatients experience adverse drug events (ADEs), which increase their mortality, morbidity, and health care use and costs. In particular, antithrombotic drugs are among the most at-risk medications for this population. Reporting systems have been implemented at the national, regional, and provider levels to monitor ADEs and design prevention strategies. Owing to their well-known limitations, automated detection technologies based on electronic medical records (EMRs) are being developed to routinely detect or predict ADEs. OBJECTIVE This study aims to develop and validate an automated detection tool for monitoring antithrombotic-related ADEs using EMRs from 4 large Swiss hospitals. We aim to assess cumulative incidences of hemorrhages and thromboses in older inpatients associated with the prescription of antithrombotic drugs, identify triggering factors, and propose improvements for clinical practice. METHODS This project is a multicenter, cross-sectional study based on 2015 to 2016 EMR data from 4 large hospitals in Switzerland: Lausanne, Geneva, and Zürich university hospitals, and Baden Cantonal Hospital. We have included inpatients aged ≥65 years who stayed at 1 of the 4 hospitals during 2015 or 2016, received at least one antithrombotic drug during their stay, and signed or were not opposed to a general consent for participation in research. First, clinical experts selected a list of relevant antithrombotic drugs along with their side effects, risks, and confounding factors. Second, administrative, clinical, prescription, and laboratory data available in the form of free text and structured data were extracted from study participants' EMRs. Third, several automated rule-based and machine learning-based algorithms are being developed, allowing for the identification of hemorrhage and thromboembolic events and their triggering factors from the extracted information. Finally, we plan to validate the developed detection tools (one per ADE type) through manual medical record review. Performance metrics for assessing internal validity will comprise the area under the receiver operating characteristic curve, F1_{1}-score, sensitivity, specificity, and positive and negative predictive values. RESULTS After accounting for the inclusion and exclusion criteria, we will include 34,522 residents aged ≥65 years. The data will be analyzed in 2022, and the research project will run until the end of 2022 to mid-2023. CONCLUSIONS This project will allow for the introduction of measures to improve safety in prescribing antithrombotic drugs, which today remain among the drugs most involved in ADEs. The findings will be implemented in clinical practice using indicators of adverse events for risk management and training for health care professionals; the tools and methodologies developed will be disseminated for new research in this field. The increased performance of natural language processing as an important complement to structured data will bring existing tools to another level of efficiency in the detection of ADEs. Currently, such systems are unavailable in Switzerland. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/40456

    GREAT3 results I: systematic errors in shear estimation and the impact of real galaxy morphology

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    We present first results from the third GRavitational lEnsing Accuracy Testing (GREAT3) challenge, the third in a sequence of challenges for testing methods of inferring weak gravitational lensing shear distortions from simulated galaxy images. GREAT3 was divided into experiments to test three specific questions, and included simulated space- and ground-based data with constant or cosmologically-varying shear fields. The simplest (control) experiment included parametric galaxies with a realistic distribution of signal-to-noise, size, and ellipticity, and a complex point spread function (PSF). The other experiments tested the additional impact of realistic galaxy morphology, multiple exposure imaging, and the uncertainty about a spatially-varying PSF; the last two questions will be explored in Paper II. The 24 participating teams competed to estimate lensing shears to within systematic error tolerances for upcoming Stage-IV dark energy surveys, making 1525 submissions overall. GREAT3 saw considerable variety and innovation in the types of methods applied. Several teams now meet or exceed the targets in many of the tests conducted (to within the statistical errors). We conclude that the presence of realistic galaxy morphology in simulations changes shear calibration biases by 1\sim 1 per cent for a wide range of methods. Other effects such as truncation biases due to finite galaxy postage stamps, and the impact of galaxy type as measured by the S\'{e}rsic index, are quantified for the first time. Our results generalize previous studies regarding sensitivities to galaxy size and signal-to-noise, and to PSF properties such as seeing and defocus. Almost all methods' results support the simple model in which additive shear biases depend linearly on PSF ellipticity.Comment: 32 pages + 15 pages of technical appendices; 28 figures; submitted to MNRAS; latest version has minor updates in presentation of 4 figures, no changes in content or conclusion

    US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

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    This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference
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