6 resultados para reference points

em CentAUR: Central Archive University of Reading - UK


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Earlier studies showed that the disparity with respect to other visible points could not explain stereoacuity performance, nor could various spatial derivatives of disparity [Glennerster, A., McKee, S. P., & Birch, M. D. (2002). Evidence of surface-based processing of binocular disparity. Current Biology, 12:825-828; Petrov, Y., & Glennerster, A. (2004). The role of the local reference in stereoscopic detection of depth relief. Vision Research, 44:367-376.] Two possible cues remain: (i) local changes in disparity gradient or (ii) disparity with respect to an interpolated line drawn through the reference points. Here, we aimed to distinguish between these two cues. Subjects judged.. in a two AFC paradigm, whether a target dot was in front of a plane defined by three reference dots or, in other experiments, in front of a line defined by two reference dots. We tested different slants of the reference line or plane and different locations of the target relative to the reference points. For slanted reference lines or plane, stereoacuity changed little as the target position was varied. For judgments relative to a frontoparallel reference line, stereoacuity did vary with target position, but less than would be predicted by disparity gradient change. This provides evidence that disparity with respect to the reference plane is an important cue. We discuss the potential advantages of this measure in generating a representation of surface relief that is invariant to viewpoint transformations. (c) 2006 Elsevier Ltd. All rights reserved.

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This paper deals with second-generation, one-and-a-half generation and ‘‘prolonged sojourner” Trinidadian transnational migrants, who have decided to ‘return’ to the birthplace of their parents. Based on 40 in-depth interviews, the paper considers both the positive and critical things that these youthful transnational migrants report about returning to, and living in, this multi-ethnic plural society and the salience of racial and colour-class stratification as part of their return migration experiences. Our qualitative analysis is based on the narratives provided by these youthful returnees, as relayed ‘‘in their own words”, presenting critical reflections on racism, racial identities and experiences as transnational Trinidadians. It is clear that it is contexts such as contemporary working environments, family and community that act as the reference points for the adaptation ‘‘back home” of this strongly middle-class cohort. We accordingly encounter a diverse, sometimes contesting set of racial issues that emerge as salient concerns for these returnees. The consensus is that matters racial remain as formidable legacies in the hierarchical stratification of Trinidadian society for a sizeable number. Many of our respondents reported the positive aspects of racial affirmation on return. But for another sub-set, the fact that multi-ethnic and multi-cultural mixing are proudly embraced in Trinidad meant that it was felt that return experiences were not overly hindered, or blighted by obstacles of race and colour-class. For these returnees, Trinidad and Tobago is seen as representing a 21st century ‘‘Melting Pot”. But for others the continued existence of racial divisions within society – between ethnic groups and among those of different skin shades – was lamented. In the views of these respondents, too much racial power is still ascribed to ‘near-whiteness’. But for the most part, the returnees felt that where race played a part in their new lives, this generally served to advantage them. However, although the situation in Trinidad appears to have been moderated by assumptions that it remains a racial ‘Melting Pot’, the analysis strongly suggests that the colour-class system of stratification is still playing an essential role, along with racial stereotyping in society at large.

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This document provides guidelines for fish stock assessment and fishery management using the software tools and other outputs developed by the United Kingdom's Department for International Development's Fisheries Management Science Programme (FMSP) from 1992 to 2004. It explains some key elements of the precautionary approach to fisheries management and outlines a range of alternative stock assessment approaches that can provide the information needed for such precautionary management. Four FMSP software tools, LFDA (Length Frequency Data Analysis), CEDA (Catch Effort Data Analysis), YIELD and ParFish (Participatory Fisheries Stock Assessment), are described with which intermediary parameters, performance indicators and reference points may be estimated. The document also contains examples of the assessment and management of multispecies fisheries, the use of Bayesian methodologies, the use of empirical modelling approaches for estimating yields and in analysing fishery systems, and the assessment and management of inland fisheries. It also provides a comparison of length- and age-based stock assessment methods. A CD-ROM with the FMSP software packages CEDA, LFDA, YIELD and ParFish is included.

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The British Jewish novelist Howard Jacobson has, from the start of his career, found himself saddled with the unenviable label of 'the English Philip Roth'. For many years, Jacobson bristled at the Roth comparisons, offering the alternative label 'the Jewish Jane Austen' and insisting that he had not read Roth at all, though more recently he has put on record his admiration for Roth's comic masterpiece, Sabbath's Theater.If Jacobson's early work was certainly imbued with a Rothian Jewish humour, its cultural reference points were almost invariably English. In contrast, Kalooki Nights is saturated with allusions to American culture, in particular Jewish American culture. This article traces some of the ways in which Kalooki Nights explores and exploits these transatlantic connections in a comic novel that both participates in and satirizes what will be called here the fetishization of the Holocaust. It is concluded that Kalooki Nights is Jacobson's audacious attempt to produce a piece of Holocaust literature that exploits the tension between the desire of some Jews of his generation to know all the 'gory details', and the necessity of recognizing that their own historical situation prevents them from ever doing so. The result is to make people laugh not at the events of the Holocaust itself but at the attempt to fetishize them.

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This paper finds preference reversals in measurements of ambiguity aversion, even if psychological and informational circumstances are kept constant. The reversals are of a fundamentally different nature than the reversals found before because they cannot be explained by context-dependent weightings of attributes. We offer an explanation based on Sugden's random-reference theory, with different elicitation methods generating different random reference points. Then measurements of ambiguity aversion that use willingness to pay are confounded by loss aversion and hence overestimate ambiguity aversion.