203 research outputs found

    An Analysis of First Impression in the Reading of Electrical Schematic Diagrams

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    The initial impression of electronic troubleshooters of schematic diagrams was studied in a series of two experiments. In one experiment the time available to the subjects to view the information was restricted to 12 seconds and in the second experiment the subjects could look at the material as often and as long as they wished. The characteristics of the first element redrawn were: (1) the same elements were consistently selected, (2) the element was chunked with other elements, (3) the element was in a branch instead of a loop, (4) the element was along the exterior of the element and (5) the element was active more often than would be expected from the number of active elements in the circuit.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Generalized Drinfeld-Sokolov Hierarchies II: The Hamiltonian Structures

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    In this paper we examine the bi-Hamiltonian structure of the generalized KdV-hierarchies. We verify that both Hamiltonian structures take the form of Kirillov brackets on the Kac-Moody algebra, and that they define a coordinated system. Classical extended conformal algebras are obtained from the second Poisson bracket. In particular, we construct the WnlW_n^l algebras, first discussed for the case n=3n=3 and l=2l=2 by A. Polyakov and M. Bershadsky.Comment: 41 page

    Analysis of microRNA turnover in mammalian cells following Dicer1 ablation

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    Although microRNAs (miRNAs) are key regulators of gene expression, little is known of their overall persistence in the cell following processing. Characterization of such persistence is key to the full appreciation of their regulatory roles. Accordingly, we measured miRNA decay rates in mouse embryonic fibroblasts following loss of Dicer1 enzymatic activity. The results confirm the inherent stability of miRNAs, the intracellular levels of which were mostly affected by cell division. Using the decay rates of a panel of six miRNAs representative of the global trend of miRNA decay, we establish a mathematical model of miRNA turnover and determine an average miRNA half-life of 119 h (i.e. ∼5 days). In addition, we demonstrate that select miRNAs turnover more rapidly than others. This study constitutes, to our knowledge, the first in-depth characterization of miRNA decay in mammalian cells. Our findings indicate that miRNAs are up to 10× more stable than messenger RNA and support the existence of novel mechanism(s) controlling selective miRNA cellular concentration and function

    Researching the mental health needs of hard-to-reach groups: managing multiple sources of evidence

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    Background: common mental health problems impose substantial challenges to patients, carers, and health care systems. A range of interventions have demonstrable efficacy in improving the lives of people experiencing such problems. However many people are disadvantaged, either because they are unable to access primary care, or because access does not lead to adequate help. New methods are needed to understand the problems of access and generate solutions. In this paper we describe our methodological approach to managing multiple and diverse sources of evidence, within a research programme to increase equity of access to high quality mental health services in primary care.Methods: we began with a scoping review to identify the range and extent of relevant published material, and establish key concepts related to access. We then devised a strategy to collect - in parallel - evidence from six separate sources: a systematic review of published quantitative data on access-related studies; a meta-synthesis of published qualitative data on patient perspectives; dialogues with local stakeholders; a review of grey literature from statutory and voluntary service providers; secondary analysis of patient transcripts from previous qualitative studies; and primary data from interviews with service users and carers.We synthesised the findings from these diverse sources, made judgements on key emerging issues in relation to needs and services, and proposed a range of potential interventions. These proposals were debated and refined using iterative electronic and focus group consultation procedures involving international experts, local stakeholders and service users.Conclusions: our methods break new ground by generating and synthesising multiple sources of evidence, connecting scientific understanding with the perspectives of users, in order to develop innovative ways to meet the mental health needs of under-served group
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