1,638 research outputs found

    Examining the mortality effects of the Irish National Smoking Ban.

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    Secondhand smoke causes disease and death in those exposed, with cardiovascular and respiratory problems as the most likely outcomes. The purpose of this study was to examine the mortality effects of the Irish national smoking ban of 2004

    Knot commensurability and the Berge conjecture

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    We investigate commensurability classes of hyperbolic knot complements in the generic case of knots without hidden symmetries. We show that such knot complements which are commensurable are cyclically commensurable, and that there are at most 33 hyperbolic knot complements in a cyclic commensurability class. Moreover if two hyperbolic knots have cyclically commensurable complements, then they are fibered with the same genus and are chiral. A characterisation of cyclic commensurability classes of complements of periodic knots is also given. In the non-periodic case, we reduce the characterisation of cyclic commensurability classes to a generalization of the Berge conjecture.Comment: v3: This version is reorganized with minor errors fixed. Proposition 4.1, Corollary 4.2, and Proposition 5.8 were added. Question 7.2 was upgraded to Theorem 7.2. 30 pages, 1 figur

    Anthropometric discriminators of type 2 diabetes among White and Black American adults

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    BACKGROUND: The aim of the present study was to determine the best anthropometric discriminators of type 2 diabetes mellitus (T2DM) among White and Black males and females in a large US sample. METHODS: We used Atherosclerosis Risk in Communities study baseline data (1987–89) from 15 242 participants (1827 with T2DM) aged 45–65 years. Anthropometric measures included a body shape index (ABSI), body adiposity index (BAI), body mass index, waist circumference (WC), waist:height ratio (WHtR), and waist:hip ratio (WHR). All anthropometric measures were standardized to Z-scores. Using logistic regression, odds ratios for T2DM were adjusted for age, physical activity, and family history of T2DM. The Akaike information criterion and receiver operating characteristic C-statistic were used to select the best-fit models. RESULTS: Body mass index, WC, WHtR, and WHR were comparable discriminators of T2DM among White and Black males, and were superior to ABSI and BAI in predicting T2DM (P < 0.0001). Waist circumference, WHtR, and WHR were the best discriminators among White females, whereas WHR was the best discriminator among Black females. The ABSI was the poorest discriminator of T2DM for all race–gender groups except Black females. Anthropometric values distinguishing T2DM cases from non-cases were lower for Black than White adults. CONCLUSIONS: Anthropometric measures that included WC, either alone or relative to height (WHtR) or hip circumference (WHR), were the strongest discriminators of T2DM across race–gender groups. Body mass index was a comparable discriminator to WC, WHtR, and WHR among males, but not females

    Hidden structure in the randomness of the prime number sequence?

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    We report a rigorous theory to show the origin of the unexpected periodic behavior seen in the consecutive differences between prime numbers. We also check numerically our findings to ensure that they hold for finite sequences of primes, that would eventually appear in applications. Finally, our theory allows us to link with three different but important topics: the Hardy-Littlewood conjecture, the statistical mechanics of spin systems, and the celebrated Sierpinski fractal.Comment: 13 pages, 5 figures. New section establishing connection with the Hardy-Littlewood theory. Published in the journal where the solved problem was first describe

    Primitive Words, Free Factors and Measure Preservation

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    Let F_k be the free group on k generators. A word w \in F_k is called primitive if it belongs to some basis of F_k. We investigate two criteria for primitivity, and consider more generally, subgroups of F_k which are free factors. The first criterion is graph-theoretic and uses Stallings core graphs: given subgroups of finite rank H \le J \le F_k we present a simple procedure to determine whether H is a free factor of J. This yields, in particular, a procedure to determine whether a given element in F_k is primitive. Again let w \in F_k and consider the word map w:G x G x ... x G \to G (from the direct product of k copies of G to G), where G is an arbitrary finite group. We call w measure preserving if given uniform measure on G x G x ... x G, w induces uniform measure on G (for every finite G). This is the second criterion we investigate: it is not hard to see that primitivity implies measure preservation and it was conjectured that the two properties are equivalent. Our combinatorial approach to primitivity allows us to make progress on this problem and in particular prove the conjecture for k=2. It was asked whether the primitive elements of F_k form a closed set in the profinite topology of free groups. Our results provide a positive answer for F_2.Comment: This is a unified version of two manuscripts: "On Primitive words I: A New Algorithm", and "On Primitive Words II: Measure Preservation". 42 pages, 14 figures. Some parts of the paper reorganized towards publication in the Israel J. of Mat

    Police Officer v. Administration Attitudes Toward Organizational Change

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    Discusses handling of change within organizations. Concludes there is no difference in attitude between officers and administrators

    Delayed commutation in quantum computer networks

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    In the same way that classical computer networks connect and enhance the capabilities of classical computers, quantum networks can combine the advantages of quantum information and communications. We propose a non-classical network element, a delayed commutation switch, that can solve the problem of switching time in packet switching networks. With the help of some local ancillary qubits and superdense codes we can route the information after part of it has left the network node.Comment: 4 pages. 4 figures. Preliminar versio

    Post- and peritraumatic stress in disaster survivors: An explorative study about the influence of individual and event characteristics across different types of disasters

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    Background: Examination of existing research on posttraumatic adjustment after disasters suggests that survivors’ posttraumatic stress levels might be better understood by investigating the influence of the characteristics of the event experienced on how people thought and felt, during the event as well as afterwards. Objective: To compare survivors’ perceived post- and peritraumatic emotional and cognitive reactions across different types of disasters. Additionally, to investigate individual and event characteristics. Design: In a European multi-centre study, 102 survivors of different disasters terror attack, flood, fire and collapse of a building were interviewed about their responses during the event. Survivors’ perceived posttraumatic stress levels were assessed with the Impact of Event Scale-Revised (IES-R). Peritraumatic emotional stress and risk perception were rated retrospectively. Influences of individual characteristics, such as socio-demographic data, and event characteristics, such as time and exposure factors, on post- and peritraumatic outcomes were analyzed. Results: Levels of reported post- and peritraumatic outcomes differed significantly between types of disasters. Type of disaster was a significant predictor of all three outcome variables but the factors gender, education, time since event, injuries and fatalities were only significant for certain outcomes. Conclusion: Results support the hypothesis that there are differences in perceived post- and peritraumatic emotional and cognitive reactions after experiencing different types of disasters. However, it should be noted that these findings were not only explained by the type of disaster itself but also by individual and event characteristics. As the study followed an explorative approach, further research paths are discussed to better understand the relationships between variables

    Genome-wide mapping of the distribution of CarD, RNAP σA, and RNAP β on the Mycobacterium smegmatis chromosome using chromatin immunoprecipitation sequencing

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    CarD is an essential mycobacterial protein that binds the RNA polymerase (RNAP) and affects the transcriptional profile of Mycobacterium smegmatis and Mycobacterium tuberculosis [6]. We predicted that CarD was directly regulating RNAP function but our prior experiments had not determined at what stage of transcription CarD was functioning and at which genes CarD interacted with the RNAP. To begin to address these open questions, we performed chromatin immunoprecipitation sequencing (ChIP-seq) to survey the distribution of CarD throughout the M. smegmatis chromosome. The distribution of RNAP subunits β and σA were also profiled. We expected that RNAP β would be present throughout transcribed regions and RNAP σA would be predominantly enriched at promoters based on work in Escherichia coli [3], however this had yet to be determined in mycobacteria. The ChIP-seq analyses revealed that CarD was never present on the genome in the absence of RNAP, was primarily associated with promoter regions, and was highly correlated with the distribution of RNAP σA. The colocalization of σA and CarD led us to propose that in vivo, CarD associates with RNAP initiation complexes at most promoters and is therefore a global regulator of transcription initiation. Here we describe in detail the data from the ChIP-seq experiments associated with the study published by Srivastava and colleagues in the Proceedings of the National Academy of Science in 2013 [5] as well as discuss the findings from this dataset in relation to both CarD and mycobacterial transcription as a whole. The ChIP-seq data have been deposited in the Gene Expression Omnibus (GEO) database, www.ncbi.nlm.nih.gov/geo (accession no. GSE48164)
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