2,765 research outputs found

    Preemptive Uniprocessor Scheduling of Mixed-Criticality Sporadic Task Systems

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    Study of the Reliability of Statistical Timing Analysis for Real-Time Systems

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    Presented at 23rd International Conference on Real-Time Networks and Systems (RTNS 2015). 4 to 6, Nov, 2015, Main Track. Lille, France.Probabilistic and statistical temporal analyses have been developedas a means of determining the worst-case execution and responsetimes of real-time software for decades. A number of such methodshave been proposed in the literature, of which the majority claim tobe able to provide worst-case timing scenarios with respect to agiven likelihood of a certain value being exceeded. Further, suchclaims are based on either some estimates associated with a probability,or probability distributions with a certain level of confidence.However, the validity of the claims are very much dependent on anumber of factors, such as the achieved samples and the adopteddistributions for analysis.In this paper, we investigate whether the claims made are in facttrue as well as the establishing an understanding of the factors thataffect the validity of these claims. The results are of importancefor two reasons: to allow researchers to examine whether there areimportant issues that mean their techniques need to be refined; andso that practitioners, including industrialists who are currently usingcommercial timing analysis tools based on these types of techniques,understand how the techniques should be used to ensure theresults are fit for their purposes

    An optimal gap theorem

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    By solving the Cauchy problem for the Hodge-Laplace heat equation for dd-closed, positive (1,1)(1, 1)-forms, we prove an optimal gap theorem for K\"ahler manifolds with nonnegative bisectional curvature which asserts that the manifold is flat if the average of the scalar curvature over balls of radius rr centered at any fixed point oo is a function of o(r2)o(r^{-2}). Furthermore via a relative monotonicity estimate we obtain a stronger statement, namely a `positive mass' type result, asserting that if (M,g)(M, g) is not flat, then lim infrr2Vo(r)Bo(r)S(y)dμ(y)>0\liminf_{r\to \infty} \frac{r^2}{V_o(r)}\int_{B_o(r)}\mathcal{S}(y)\, d\mu(y)>0 for any oMo\in M

    A Qualitative Analysis of Motivators to Participation in Suicide-Focused Research from a Community-Based Australian Sample

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    Suicide prevention strategies internationally appear to be falling short of making a meaningful impact on global suicide deaths. Increasing the rates of general community participation in suicide research may improve knowledge generalisability as it relates to suicidal behaviour and leads to new suicide prevention approaches. This study aims to explore the motivations of a community-based sample to participate in suicide research. A subsample of the Australian general population took part in an online survey which is part of a multilevel suicide prevention trial. The survey concluded with an optional open-text question asking about peoples’ motivations for participating in the study; 532 participants left a response to this question. These responses were qualitatively analysed using Thematic Network Analysis. Motivations to participate in suicide research were represented by four global themes: altruism, solve systemic problems, lived experience, and personal benefit. Of these themes, three were focused on the benefit of others, while only the final theme articulated motivation to participate that was self-focused. The impact of suicide is felt throughout the wider community. This new understanding of the motivations of community-based samples to participate in suicide research should be used to increase participation rates and reach people who would not normally contribute their voice to suicide researc

    A qualitative analysis of motivators to participation in suicide-focused research from a community-based australian sample

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    Suicide prevention strategies internationally appear to be falling short of making a meaningful impact on global suicide deaths. Increasing the rates of general community participation in suicide research may improve knowledge generalisability as it relates to suicidal behaviour and leads to new suicide prevention approaches. This study aims to explore the motivations of a communitybased sample to participate in suicide research. A subsample of the Australian general population took part in an online survey which is part of a multilevel suicide prevention trial. The survey concluded with an optional open-text question asking about peoples’ motivations for participating in the study; 532 participants left a response to this question. These responses were qualitatively analysed using Thematic Network Analysis. Motivations to participate in suicide research were represented by four global themes: altruism, solve systemic problems, lived experience, and personal benefit. Of these themes, three were focused on the benefit of others, while only the final theme articulated motivation to participate that was self-focused. The impact of suicide is felt throughout the wider community. This new understanding of the motivations of community-based samples to participate in suicide research should be used to increase participation rates and reach people who would not normally contribute their voice to suicide research

    Emerging invasive group A Streptococcus M1UK lineage detected by allele-specific PCR, England, 2020

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    Increasing reports of invasive Streptococcus pyogenes infections mandate surveillance for toxigenic lineage M1UK. An allele-specific PCR was developed to distinguish M1UK from other emm1 strains. The M1UK lineage represented 91% of invasive emm1 isolates in England in 2020. Allele-specific PCR will permit surveillance for M1UK without need for genome sequencing

    Sprouty2 mediated tuning of signalling is essential for somite myogenesis

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    Background: Negative regulators of signal transduction cascades play critical roles in controlling different aspects of normal embryonic development. Sprouty2 (Spry2) negatively regulates receptor tyrosine kinases (RTK) and FGF signalling and is important in differentiation, cell migration and proliferation. In vertebrate embryos, Spry2 is expressed in paraxial mesoderm and in forming somites. Expression is maintained in the myotome until late stages of somite differentiation. However, its role and mode of action during somite myogenesis is still unclear. Results: Here, we analysed chick Spry2 expression and showed that it overlaps with that of myogenic regulatory factors MyoD and Mgn. Targeted mis-expression of Spry2 led to inhibition of myogenesis, whilst its C-terminal domain led to an increased number of myogenic cells by stimulating cell proliferation. Conclusions: Spry2 is expressed in somite myotomes and its expression overlaps with myogenic regulatory factors. Overexpression and dominant-negative interference showed that Spry2 plays a crucial role in regulating chick myogenesis by fine tuning of FGF signaling through a negative feedback loop. We also propose that mir-23, mir-27 and mir-128 could be part of the negative feedback loop mechanism. Our analysis is the first to shed some light on in vivo Spry2 function during chick somite myogenesis

    X-ray absorption spectroscopy (XAS) investigation of the electronic structure of superconducting FeSex single crystals

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    X-ray absorption spectroscopy (XAS) Fe K-edge spectra of the FeSex (x=1-0.8) single crystals cleaved in situ in vacuum reveal characteristic Fe 4sp states, a lattice distortion and the Se K-edge spectra point to a strong Fe 3d-Se 4p hybridization giving rise to itinerant charge carriers. A formal charge of ~1.8+ for Fe and ~2.2- for Se were evaluated from these spectra in the FeSex (x=0.88). The charge balance between Fe and Se is assigned itinerant electrons located in the Fe-Se hybridization bond. As x decreases the 4p hole count increases and a crystal structure distortion is observed that in turn causes the Fe separation in the ab plane change from 4p orbital to varying (modulating) coordination. Powder x-ray diffraction (XRD) measurements also show a slight increase in lattice parameters as x decreases (increasing Se deficiency)
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