3,176 research outputs found

    The Archean crust in the Wawa-Chapleau-Timmins region. A field guidebook prepared for the 1983 Archean Geochemistry-Early Crustal Genesis Field Conference

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    This guidebook describes the characteristics and interrelationships of Archean greenstone-granite and high-grade gneiss terrains of the Superior Province. A 300-km long west to east transect between Wawa and Timmins, Ontario will be used to illustrate regional-scale relationships. The major geological features of the Superior Province are described

    Preliminary design of large reflectors with flat facets

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    A concept for approximating curved antenna surfaces using flat facets is discussed. A preliminary design technique for determining the size of the reflector surface facets necessary to meet antenna surface accuracy requirements is presented. A proposed large Microwave Radiometer Satellite is selected as an application, and the far field electromagnetic response of a faceted reflector surface is compared with that from a spherical reflector surface

    Evaluating graphical manipulations in automatically laid out LineSets

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    This paper presents an empirical study to determine whether alterations to graphical features (colour and size) of automatically generated LineSets improve task performance. LineSets are used to visualise sets and networks. The increasingly common nature of such data suggests that having effective visualisations is important. Unlike many approaches to set and network visualisation, which often use concave or convex shapes to represent sets alongside graphs, LineSets use lines overlaid on a graph. LineSets have been shown to be advantageous over shape-based approaches. However, the graphical properties of LineSets have not been fully explored. Our results suggest that automatically drawn LineSets can be significantly improved for certain tasks through the considered use of colour alongside size variations applied to their graphical elements. In particular, we show that perceptually distinguishable colours, lines of varying width, and nodes of varying diameter lead to improved task performance in automatically laid-out LineSets

    Wage returns to university disciplines in Greece: are Greek Higher Education degrees Trojan Horses?

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    This paper examines the wage returns to qualifications and academic disciplines in the Greek labour market. Exploring wage responsiveness across various degree subjects in Greece is interesting, as it is characterised by high levels of graduate unemployment, which vary considerably by field of study, and relatively low levels of wage flexibility. Using micro-data from recently available waves (2002-2003) of the Greek Labour Force Survey (LFS), the returns to academic disciplines are estimated by gender and public/private sector. Quantile regressions and cohort interactions are also used to capture the heterogeneity in wage returns across the various disciplines. The results show considerable variation in wage premiums across the fields of study, with lower returns for those that have a marginal role to play in an economy with a rising services/shrinking public sector. Educational reforms that pay closer attention to the future prospects of university disciplines are advocated

    A Dual Infection Pseudorabies Virus Conditional Reporter Approach to Identify Projections to Collateralized Neurons in Complex Neural Circuits

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    Replication and transneuronal transport of pseudorabies virus (PRV) are widely used to define the organization of neural circuits in rodent brain. Here we report a dual infection approach that highlights connections to neurons that collateralize within complex networks. The method combines Cre recombinase (Cre) expression from a PRV recombinant (PRV-267) and Cre-dependent reporter gene expression from a second infecting strain of PRV (PRV-263). PRV-267 expresses both Cre and a monomeric red fluorescent protein (mRFP) fused to viral capsid protein VP26 (VP26-mRFP) that accumulates in infected cell nuclei. PRV-263 carries a Brainbow cassette and expresses a red (dTomato) reporter that fills the cytoplasm. However, in the presence of Cre, the dTomato gene is recombined from the cassette, eliminating expression of the red reporter and liberating expression of either yellow (EYFP) or cyan (mCerulean) cytoplasmic reporters. We conducted proof-of-principle experiments using a well-characterized model in which separate injection of recombinant viruses into the left and right kidneys produces infection of neurons in the renal preautonomic network. Neurons dedicated to one kidney expressed the unique reporters characteristic of PRV-263 (cytoplasmic dTomato) or PRV-267 (nuclear VP26-mRFP). Dual infected neurons expressed VP26-mRFP and the cyan or yellow cytoplasmic reporters activated by Cre-mediated recombination of the Brainbow cassette. Differential expression of cyan or yellow reporters in neurons lacking VP26-mRFP provided a unique marker of neurons synaptically connected to dual infected neurons, a synaptic relationship that cannot be distinguished using other dual infection tracing approaches. These data demonstrate Cre-enabled conditional reporter expression in polysynaptic circuits that permits the identification of collateralized neurons and their presynaptic partners

    Task analysis for error identification: Theory, method and validation

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    This paper presents the underlying theory of Task Analysis for Error Identification. The aim is to illustrate the development of a method that has been proposed for the evaluation of prototypical designs from the perspective of predicting human error. The paper presents the method applied to representative examples. The methodology is considered in terms of the various validation studies that have been conducted, and is discussed in the light of a specific case study

    Extracting invariant characteristics of sketch maps: Towards place query-by-sketch

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    In geography, invariant aspects of sketches are essential to study because they reflect the human perception of real-world places. A person's perception of a place can be ex-pressed in sketches. In this article, we quantitatively and qualitatively analyzed the characteristics of single objects and characteristics among objects in sketches and the real world to find reliable invariants that can be used to establish references/correspondences between sketch and world in a matching process. These characteristics include category, shape, name, and relative size of each object. Moreover, quantity and spatial relationships—such as topological, or-dering, and location relationships—among all objects are also analyzed to assess consistency between sketched and actual places. The approach presented in this study extracts the reliable invariants for query-by-sketch and prioritizes their relevance for a sketch-map matching process
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