Pilgrims and MERS-CoV: What's the risk?

10.1186/s12982-015-0025-8Emerging Themes in Epidemiology12

Ranking Templates for Linear Loops

We present a new method for the constraint-based synthesis of termination arguments for linear loop programs based on linear ranking templates. Linear ranking templates are parametrized, well-founded relations such that an assignment to the parameters gives rise to a ranking function. This approach generalizes existing methods and enables us to use templates for many different ranking functions with affine-linear components. We discuss templates for multiphase, piecewise, and lexicographic ranking functions. Because these ranking templates require both strict and non-strict inequalities, we use Motzkin's Transposition Theorem instead of Farkas Lemma to transform the generated $\exists\forall$-constraint into an $\exists$-constraint.Comment: TACAS 201

Proving Termination Starting from the End

We present a novel technique for proving program termination which introduces a new dimension of modularity. Existing techniques use the program to incrementally construct a termination proof. While the proof keeps changing, the program remains the same. Our technique goes a step further. We show how to use the current partial proof to partition the transition relation into those behaviors known to be terminating from the current proof, and those whose status (terminating or not) is not known yet. This partition enables a new and unexplored dimension of incremental reasoning on the program side. In addition, we show that our approach naturally applies to conditional termination which searches for a precondition ensuring termination. We further report on a prototype implementation that advances the state-of-the-art on the grounds of termination and conditional termination.Comment: 16 page

Trace Complexity of Chaotic Reversible Cellular Automata

Delvenne, K\r{u}rka and Blondel have defined new notions of computational complexity for arbitrary symbolic systems, and shown examples of effective systems that are computationally universal in this sense. The notion is defined in terms of the trace function of the system, and aims to capture its dynamics. We present a Devaney-chaotic reversible cellular automaton that is universal in their sense, answering a question that they explicitly left open. We also discuss some implications and limitations of the construction.Comment: 12 pages + 1 page appendix, 4 figures. Accepted to Reversible Computation 2014 (proceedings published by Springer

Unrestricted Termination and Non-Termination Arguments for Bit-Vector Programs

Proving program termination is typically done by finding a well-founded ranking function for the program states. Existing termination provers typically find ranking functions using either linear algebra or templates. As such they are often restricted to finding linear ranking functions over mathematical integers. This class of functions is insufficient for proving termination of many terminating programs, and furthermore a termination argument for a program operating on mathematical integers does not always lead to a termination argument for the same program operating on fixed-width machine integers. We propose a termination analysis able to generate nonlinear, lexicographic ranking functions and nonlinear recurrence sets that are correct for fixed-width machine arithmetic and floating-point arithmetic Our technique is based on a reduction from program \emph{termination} to second-order \emph{satisfaction}. We provide formulations for termination and non-termination in a fragment of second-order logic with restricted quantification which is decidable over finite domains. The resulted technique is a sound and complete analysis for the termination of finite-state programs with fixed-width integers and IEEE floating-point arithmetic

The Alcohol Relapse Situation Appraisal Questionnaire: Development and Validation

Background: The role of cognitive appraisal of the threat of alcohol relapse has received little attention. A previous instrument, the Relapse Situation Appraisal Questionnaire (RSAQ), was developed to assess cocaine users’ primary appraisal of the threat of situations posing a high risk for cocaine relapse. The purpose of the present study was to modify the RSAQ in order to measure primary appraisal in situations involving a high risk for alcohol relapse. Methods: The development and psychometric properties of this instrument, the Alcohol Relapse Situation Appraisal Questionnaire (A-RSAQ), were examined with two samples of abstinent adults with alcohol abuse or dependence. Factor structure and validity were examined in Study 1 (N= 104). Confirmation of the factor structure and predictive validity was assessed in Study 2 (N= 159). Results: Results demonstrated construct, discriminant and predictive validity and reliability of the ARSAQ. Discussion: Results support the important role of primary appraisal of degree of risk in alcohol relapse situations

Heavy mineral analysis by ICP-AES a tool to aid sediment provenancing

Correlation and provenancing of sediments/sedimentary rocks can be achieved by several techniques; a common approach is through the identification and quantification of heavy minerals using a petrological microscope. This can be time consuming, the analysis of heavy minerals by inductively coupled plasma atomic emission spectroscopy offers a faster alternative, by determining key elements associated with specific heavy minerals. Here we outline a method for determining heavy mineral species though ICP-AES using high temperature fusion with a lithium metaborate flux to ensure complete dissolution of resistate minerals. The method was tested in a provenance study of desert sands from the United Arab Emirates. The results are compared with those derived from traditional optical microscopy. These show good agreement for minerals with specific geochemical signatures, whilst the overall geochemistry of the heavy mineral concentrate was diagnostic of potential sediment sources. This geochemical approach is capable of processing large numbers of samples rapidly and is advocated as a screening technique. A combination of geochemical and mineralogical data produced by these techniques provides a powerful diagnostic tool for studies of heavy mineral signatures in sediments frequently used in mineral reconnaissance, paleogeographic reconstruction and reservoir characterisation in the petroleum industry

The Paranormal is (Still) Normal: The Sociological Implications of a Survey of Paranormal Experiences in Great Britain

Historically, there has been limited sociological interest in the paranormal and no systematic study of reported paranormal experiences. There are also few medium-to-large-scale survey results with nationally representative populations focusing on paranormal experiences. This paper provides details of an exploratory survey conducted in 2009 with a nationally representative sample of 4,096 adults aged 16 years and over across Great Britain. Our findings show that 37% of British adults report at least one paranormal experience and that women, those who are middle-aged or individuals resident in the South West are more likely to report such experiences. These results establish incidence levels of reported paranormal experiences in contemporary Britain. We argue also that they merit a more sustained sociological consideration of the paranormal. In this respect we renew and update the robust justification and call for serious research positioning the paranormal as a social phenomenon, originally proposed well over thirty years ago by Greeley (1975)

Serological response in RT-PCR confirmed h1n1-2009 influenza a by hemagglutination inhibition and virus neutralization assays: An observational study

10.1371/journal.pone.0012474PLoS ONE58

Termination Analysis with Compositional Transition Invariants

Modern termination provers rely on a safety checker to construct disjunctively well-founded transition invariants. This safety check is known to be the bottleneck of the procedure. We present an alternative algorithm that uses a light-weight check based on transitivity of ranking relations to prove program termination. We provide an exper-imental evaluation over a set of 87 Windows drivers, and demonstrate that our algorithm is often able to conclude termination by examining only a small fraction of the program. As a consequence, our algorithm is able to outperform known approaches by multiple orders of magnitude