1,663 research outputs found

    The Role of Deontic Logic in the Specification of Information Systems

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    In this paper we discuss the role that deontic logic plays in the specification of information systems, either because constraints on the systems directly concern norms or, and even more importantly, system constraints are considered ideal but violable (so-called `soft¿ constraints).\ud To overcome the traditional problems with deontic logic (the so-called paradoxes), we first state the importance of distinguishing between ought-to-be and ought-to-do constraints and next focus on the most severe paradox, the so-called Chisholm paradox, involving contrary-to-duty norms. We present a multi-modal extension of standard deontic logic (SDL) to represent the ought-to-be version of the Chisholm set properly. For the ought-to-do variant we employ a reduction to dynamic logic, and show how the Chisholm set can be treated adequately in this setting. Finally we discuss a way of integrating both ought-to-be and ought-to-do reasoning, enabling one to draw conclusions from ought-to-be constraints to ought-to-do ones, and show by an example the use(fulness) of this

    Tumour-agnostic drugs in paediatric cancers.

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    The recognition that new cancer drugs can be truly tumour-agnostic based on mechanism-of-action is important for paediatric cancers, where access to novel targeted therapies developed for adult indications has sometimes been problematic. The recently approved drug larotrectinib is an excellent case study of the development of a tumour-agnostic drug relevant to children

    PEPtalk2: results of a pilot randomised controlled trial to compare VZIG and aciclovir as postexposure prophylaxis (PEP) against chickenpox in children with cancer.

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    OBJECTIVE: To determine the likely rate of patient randomisation and to facilitate sample size calculation for a full-scale phase III trial of varicella zoster immunoglobulin (VZIG) and aciclovir as postexposure prophylaxis against chickenpox in children with cancer. DESIGN: Multicentre pilot randomised controlled trial of VZIG and oral aciclovir. SETTING: England, UK. PATIENTS: Children under 16 years of age with a diagnosis of cancer: currently or within 6 months of receiving cancer treatment and with negative varicella zoster virus (VZV) serostatus at diagnosis or within the last 3 months. INTERVENTIONS: Study participants who have a significant VZV exposure were randomised to receive PEP in the form of VZIG or aciclovir after the exposure. MAIN OUTCOME MEASURES: Number of patients registered and randomised within 12 months of the trial opening to recruitment and incidence of breakthrough varicella. RESULTS: The study opened in six sites over a 13-month period. 482 patients were screened for eligibility, 32 patients were registered and 3 patients were randomised following VZV exposure. All three were randomised to receive aciclovir and there were no cases of breakthrough varicella. CONCLUSIONS: Given the limited recruitment to the PEPtalk2 pilot, it is unlikely that the necessary sample size would be achievable using this strategy in a full-scale trial. The study identified factors that could be used to modify the design of a definitive trial but other options for defining the best means to protect such children against VZV should be explored. TRIAL REGISTRATION NUMBER: ISRCTN48257441, EudraCT number: 2013-001332-22, sponsor: University of Birmingham

    Assessing feasibility and acceptability of web-based enhanced relapse prevention for bipolar disorder (ERPonline): a randomized controlled trial

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    Background: Interventions that teach people with Bipolar Disorder (BD) to recognise and respond to early warning signs of relapse are NICE recommended but implementation in clinical practice is poor. Objective: This study tests the feasibility and acceptability of a randomised controlled trial to evaluate an online enhanced relapse prevention intervention (ERPonline), and reports preliminary evidence of effectiveness. Methods: Single blind, parallel primarily online randomised controlled trial (n=96) over 48 weeks comparing ERPonline plus usual treatment to waitlist (WL) control plus usual treatment for people with BD recruited through National Health Services, voluntary organisations, and media. Randomisation was independent, minimised on number of previous episodes (<8,8-20,21+). Primary outcomes were feasibility and acceptability assessed by rates of study recruitment and retention, levels of intervention use, adverse events and participant feedback. Process and clinical outcomes were assessed by telephone and online and compared using linear models with intention-to-treat analysis. Results: Two hundred and eighty people registered interest online, from which ninety-six met inclusion criteria, consented and were randomised (49 to WL, 47 to ERPonline) over seventeen months, with 80% retention in telephone and online follow up, except week 48 online (76%). Acceptability was high for both ERPonline and trial methods. ERPonline cost approximately £19,340 to create, and £2176 per year to host and maintain the site. Qualitative data highlighted the importance of the relationship users have with online interventions and how this is created as an extension of the relationship with the humans perceived as offering and supporting its use. Differences between the group means suggested that access to ERPonline was associated with: a more positive model of bipolar disorder at 24 (10.70 (0.90-20.5 95%CIs)) and 48 weeks (13.1 (2.44-23.93 95%CIs)); increased monitoring of early warning signs of depression at 48 weeks (-1.39 (-2.61, -.163 95%CIs)) and of (hypo)mania at 24 (-1.72 (-2.98, -0.47 95%CIs)) and 48 weeks (-1.61 (-2.92, -0.30 95%CIs)), compared to WL. There was no evidence of impact of ERPonline on clinical outcomes or medication adherence, but relapse rates across both arms were very low (15%) and the sample remained high functioning throughout. One person died by suicide prior to randomisation. Five people in ERPonline and six in WL control reported ideas of suicide or self-harm during the study. None were deemed study related by an independent Trial Steering Committee. Conclusions: ERPonline offers a cheap accessible option for people seeking ongoing support following successful treatment. However, given high functioning and low relapse rates in this study, testing clinical effectiveness for this population would require very large sample sizes. Building in human support to use ERPonline should be considere

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Invasion is a community affair: clandestine followers in the bacterial community associated to green algae, Caulerpa racemosa, track the invasion source

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    Biological invasions rank amongst the most deleterious components of global change inducing alterations from genes to ecosystems. The genetic characteristics of introduced pools of individuals greatly influence the capacity of introduced species to establish and expand. The recently demonstrated heritability of microbial communities associated to individual genotypes of primary producers makes them a potentially essential element of the evolution and adaptability of their hosts. Here, we characterized the bacterial communities associated to native and non-native populations of the marine green macroalga Caulerpa racemosa through pyrosequencing, and explored their potential role on the strikingly invasive trajectory of their host in the Mediterranean. The similarity of endophytic bacterial communities from the native Australian range and several Mediterranean locations confirmed the origin of invasion and revealed distinct communities associated to a second Mediterranean variety of C. racemosa long reported in the Mediterranean. Comparative analysis of these two groups demonstrated the stability of the composition of bacterial communities through the successive steps of introduction and invasion and suggested the vertical transmission of some major bacterial OTUs. Indirect inferences on the taxonomic identity and associated metabolism of bacterial lineages showed a striking consistency with sediment upheaval conditions associated to the expansion of their invasive host and to the decline of native species. These results demonstrate that bacterial communities can be an effective tracer of the origin of invasion and support their potential role in their eukaryotic host’s adaptation to new environments. They put forward the critical need to consider the 'meta-organism' encompassing both the host and associated micro-organisms, to unravel the origins, causes and mechanisms underlying biological invasions

    The effects of using the PReDicT Test to guide the antidepressant treatment of depressed patients: study protocol for a randomised controlled trial

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    Background Antidepressant medication is commonly used to treat depression. However, many patients do not respond to the first medication prescribed and improvements in symptoms are generally only detectable by clinicians 4–6 weeks after the medication has been initiated. As a result, there is often a long delay between the decision to initiate an antidepressant medication and the identification of an effective treatment regimen. Previous work has demonstrated that antidepressant medications alter subtle measures of affective cognition in depressed patients, such as the appraisal of facial expression. Furthermore, these cognitive effects of antidepressants are apparent early in the course of treatment and can also predict later clinical response. This trial will assess whether an electronic test of affective cognition and symptoms (the Predicting Response to Depression Treatment Test; PReDicT Test) can be used to guide antidepressant treatment in depressed patients and, therefore, hasten treatment response compared to a control group of patients treated as usual. Methods/design The study is a randomised, two-arm, multi-centre, open-label, clinical investigation of a medical device, the PReDicT Test. It will be conducted in five European countries (UK, France, Spain, Germany and the Netherlands) in depressed patients who are commencing antidepressant medication. Patients will be randomised to treatment guided by the PReDicT Test (PReDicT arm) or to Treatment as Usual (TaU arm). Patients in the TaU arm will be treated as per current standard guidelines in their particular country. Patients in the PReDicT arm will complete the PReDicT Test after 1 (and if necessary, 2) weeks of treatment. If the test indicates non-response to the treatment, physicians will be advised to immediately alter the patient’s antidepressant therapy by dose escalation or switching to another compound. The primary outcome of the study is the proportion of patients showing a clinical response (defined as 50% or greater decrease in baseline scores of depression measured using the Quick Inventory of Depressive Symptoms – Self-Rated questionnaire) at week 8. Health economic and acceptability data will also be collected and analysed. Discussion This trial will test the clinical efficacy, cost-effectiveness and acceptability of using the novel PReDicT Test to guide antidepressant treatment selection in depressed patients
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