324 research outputs found

    A Branching Time Model of CSP

    Full text link
    I present a branching time model of CSP that is finer than all other models of CSP proposed thus far. It is obtained by taking a semantic equivalence from the linear time - branching time spectrum, namely divergence-preserving coupled similarity, and showing that it is a congruence for the operators of CSP. This equivalence belongs to the bisimulation family of semantic equivalences, in the sense that on transition systems without internal actions it coincides with strong bisimilarity. Nevertheless, enough of the equational laws of CSP remain to obtain a complete axiomatisation for closed, recursion-free terms.Comment: Dedicated to Bill Roscoe, on the occasion of his 60th birthda

    Preparation for the next major incident: are we ready? Comparing major trauma centres and other hospitals

    Get PDF
    OBJECTIVES: A major incident is any emergency requiring special arrangements by the emergency services. All hospitals are required by law to keep a major incident plan (MIP) detailing the response to such events. In 2006 and 2019, we assessed the preparedness and knowledge of key individuals in hospitals across England and found a substantial gap in responding to the MIP. In this report, we compare responses from doctors at major trauma centres (MTCs) and other hospitals (non-MTCs). METHODS: We identified trusts in England that received over 30 000 patients through the ED in the fourth quarter of 2016/2017. We contacted the on-call anaesthetic, emergency, general surgery and trauma and orthopaedic registrar at each location and asked three questions assessing their confidence in using their hospital’s MIP: (1) Have you read your hospital’s MIP? (2) Do you know where you can access your hospital’s MIP guidelines? (3) Do you know what role you would play if an MIP came into effect while you are on call? We compared data from MTCs and non-MTCs using multinomial mixed proportional odds models. RESULTS: There was a modest difference between responses from individuals at MTCs and non-MTCs for question 2 (OR=2.43, CI=1.03 to 5.73, p=0.04) but no evidence of a difference between question 1 (OR=1.41, CI=0.55 to 3.63, p=0.47) and question 3 (OR=1.78, CI=0.86 to 3.69, p=0.12). Emergency medicine and anaesthetic registrars showed significantly higher preparedness and knowledge across all domains. No evidence of a systematic difference in specialty response by MTC or otherwise was identified. CONCLUSIONS: Confidence in using MIPs among specialty registrars in England remains low. Doctors at MTCs tended to be better prepared and more knowledgeable, but this effect was only marginally significant. We make several recommendations to improve education on major incidents

    Information Security as Strategic (In)effectivity

    Full text link
    Security of information flow is commonly understood as preventing any information leakage, regardless of how grave or harmless consequences the leakage can have. In this work, we suggest that information security is not a goal in itself, but rather a means of preventing potential attackers from compromising the correct behavior of the system. To formalize this, we first show how two information flows can be compared by looking at the adversary's ability to harm the system. Then, we propose that the information flow in a system is effectively information-secure if it does not allow for more harm than its idealized variant based on the classical notion of noninterference

    An anisotropic elastoplastic model for soft clays based on logarithmic contractancy

    Get PDF
    A new constitutive model for soft structured clays is developed based on an existing model called S-CLAY1S, which is a Cam Clay type model that accounts for anisotropy and destructuration. The new model (E-SCLAY1S) uses the framework of logarithmic contractancy to introduce a new parameter that controls the shape of the yield surface as well as the plastic potential (as an assumed associated flow rule is applied). This new parameter can be used to fit the coefficient of earth pressure at rest, the undrained shear strength or the stiffness under shearing stress paths predicted by the model. The improvement to previous constitutive models that account for soil fabric and bonding is formulated within the contractancy framework such that the model predicts the uniqueness of the critical state line and its slope is independent of the contractancy parameter. Good agreement has been found between the model predictions and published laboratory results for triaxial compression tests. An important finding is that the contractancy parameter, and consequently the shape of the yield surface, seem to change with the degree of anisotropy; however, further study is required to investigate this response. From published data, the yield surface for isotropically consolidated clays seems “bullet” or “almond” shaped, similar to that of the Cam Clay model; while for anisotropically consolidated clays, the yield surface is more elliptical, like a rotated and distorted Modified Cam Clay yield surface

    Observed communication semantics for classical processes

    Get PDF
    Classical Linear Logic (CLL) has long inspired readings of its proofs as communicating processes. Wadler's CP calculus is one of these readings. Wadler gave CP an operational semantics by selecting a subset of the cut-elimination rules of CLL to use as reduction rules. This semantics has an appealing close connection to the logic, but does not resolve the status of the other cut-elimination rules, and does not admit an obvious notion of observational equivalence. We propose a new operational semantics for CP based on the idea of observing communication, and use this semantics to define an intuitively reasonable notion of observational equivalence. To reason about observational equivalence, we use the standard relational denotational semantics of CLL. We show that this denotational semantics is adequate for our operational semantics. This allows us to deduce that, for instance, all the cut-elimination rules of CLL are observational equivalences

    Coping style and health-related quality of life in caregivers of epilepsy patients

    Get PDF
    Epilepsy has a significant impact on health-related quality of life (HRQOL) of patients and personal coping style is an important determinant. Less is known about home caregivers. This study investigates HRQOL and coping style of both patients and caregivers and their interaction. Epilepsy patients attending the outpatient clinic of the University Medical Centre in Utrecht and their caregivers were sent EQ5D and RAND-36 questionnaires. The Utrecht Coping List was used to chart personal coping styles. HRQOL scores of patients and caregivers were compared to the general Dutch population. The association between patient and caregiver HRQOL scores was calculated. A stepwise backward multivariate linear regression analysis was used to explain variances in caregiver HRQOL. Eighty-six couples (49%) returned all questionnaires. Caregiver HRQOL scores were comparable to the general Dutch population (EQ5D: 0.88–0.88; p = 0.90, RAND-36 MCS: −2 points; p = 0.16), while patients HRQOL scores were lower (EQ5D: 0.79; p < 0.01, RAND-36 MCS −10 points; p < 0.01). However, on several specific domains, associations between patient and caregiver HRQOL scores within couples were found. Passive coping style explained 50% of variation in HRQOL scores of caregivers. As a group, caregivers of epilepsy patients have normal HRQOL, but there are significant associations between patient and caregiver HRQOL scores. Improving caregiver HRQOL through interventions on coping style might benefit patients as well. Recognizing personal coping styles of both patient and caregiver should be part of a patient-oriented approach in treatment

    Biofield Therapies: Helpful or Full of Hype? A Best Evidence Synthesis

    Get PDF
    Biofield therapies (such as Reiki, therapeutic touch, and healing touch) are complementary medicine modalities that remain controversial and are utilized by a significant number of patients, with little information regarding their efficacy. This systematic review examines 66 clinical studies with a variety of biofield therapies in different patient populations. We conducted a quality assessment as well as a best evidence synthesis approach to examine evidence for biofield therapies in relevant outcomes for different clinical populations. Studies overall are of medium quality, and generally meet minimum standards for validity of inferences. Biofield therapies show strong evidence for reducing pain intensity in pain populations, and moderate evidence for reducing pain intensity hospitalized and cancer populations. There is moderate evidence for decreasing negative behavioral symptoms in dementia and moderate evidence for decreasing anxiety for hospitalized populations. There is equivocal evidence for biofield therapies' effects on fatigue and quality of life for cancer patients, as well as for comprehensive pain outcomes and affect in pain patients, and for decreasing anxiety in cardiovascular patients. There is a need for further high-quality studies in this area. Implications and future research directions are discussed
    corecore