862 research outputs found

    Tragedy of public schools [Part 2 of 3: Report, 1964] : Prince Edward County, Virginia; a report for the Virginia Advisory Committee to the United States Commission on Civil Rights

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    A report written in 1964 for the Virginia Advisory Committee to the United States Commission on Civil Rights addressing the closing of the public schools in Prince Edward County, Va.https://scholarscompass.vcu.edu/pec_docs/1013/thumbnail.jp

    Regional similarities in the distributions of well yield from crystalline rocks in Fennoscandia

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    Well yields from Precambrian and Palaeozoic bedrock in Norway, Sweden and Finland exhibit very similar and approximately log-normal distributions: all three data sets exhibit a median yield of 600–700 L hr-1, despite the differences in climate and lithology. This similarity is tentatively reflected on a larger geographical scale by a meta-analysis of the international data sets on crystalline rock aquifers from other recently glaciated areas (i.e., without a thick regolith of weathered rock). An heuristic treatment of the Fennoscandian data sets suggests that this median yield is consistent with the following bulk properties of shallow (to c. 70–80 m depth) crystalline bedrock: transmissivity of 0.56 ± 0.30 m2 d-1 (6.4 ± 3.4 x 10-6 m2 s-1) and hydraulic conductivity of around 1.1 (± 0.6) x 10-7 m s-1

    The interplay of managerial and non-managerial controls, institutional work, and the coordination of laterally dependent hospital activities

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    This is the author accepted manuscript. The final version is available from Emerald via the DOI in this record.Purpose The purpose of this paper is to explore two hospital departments, one of which is laterally dependent on the other to function, but which are subject to distinct vertical managerial controls. This complexity in vertical–lateral relations generates tension amongst the hospital’s senior managers and a perception of coordination difficulties. However, this paper shows how the interplay between managerial and non-managerial controls, plus important employee “work”, moderates tension and facilitates day-to-day lateral coordination at the patient-facing level. Design/methodology/approach This is a case-study, relying mostly on the findings of semi-structured interviews. Theoretically, the paper draws from previous insights on inter-organisational relations (but informing the focus on intra-organisational coordination) and an “institutional work” perspective. Findings Consistent with much extant literature, this paper reveals how non-managerial controls help to moderate tensions that could emerge from the coercive use of managerial controls. However, the authors also show a maintained influence and flexibility in the managerial controls at patient-facing levels, as new circumstances unfold. Research limitations/implications The findings of this paper could generalise neither all laterally dependent spaces in hospitals nor patterns across different hospitals. The authors recommend future research into the dynamics and interaction of managerial and non-managerial controls in other complex settings, plus focus on the purposeful work of influential agents. Originality/value The paper has two primary contributions: extending our knowledge of the interplay between managerial and non-managerial controls inside complex organisations, where non-managerial controls reinforce rather than displace managerial controls, and highlighting that it is seldom just controls per se which “matter”, but also agents’ purposeful actions that facilitate coordination in complex organisations

    Global shape aftereffects in composite radial frequency patterns

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    YesIndividual radial frequency (RF) patterns are generated by modulating a circle's radius as a sinusoidal function of polar angle and have been shown to tap into global shape processing mechanisms. Composite RF patterns can reproduce the complex outlines of natural shapes and examining these stimuli may allow us to interrogate global shape mechanisms that are recruited in biologically relevant tasks. We present evidence for a global shape aftereffect in a composite RF pattern stimulus comprising two RF components. Manipulations of the shape, location, size and spatial frequency of the stimuli revealed that this aftereffect could only be explained by the attenuation of intermediate-level global shape mechanisms. The tuning of the aftereffect to test stimulus size also revealed two mechanisms underlying the aftereffect; one that was tuned to size and one that was invariant. Finally, we show that these shape mechanisms may encode some RF information. However, the RF encoding we found was not capable of explaining the full extent of the aftereffect, indicating that encoding of other shape features such as curvature are also important in global shape processing.This research was supported by a Biotechnology and Biological Sciences Research Council (BBSRC) grant #BB/L007770/1

    Multivariate Patterns in the Human Object-Processing Pathway Reveal a Shift from Retinotopic to Shape Curvature Representations in Lateral Occipital Areas, LO-1 and LO-2

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    Representations in early visual areas are organized on the basis of retinotopy, but this organizational principle appears to lose prominence in the extrastriate cortex. Nevertheless, an extrastriate region, such as the shape-selective lateral occipital cortex (LO), must still base its activation on the responses from earlier retinotopic visual areas, implying that a transition from retinotopic to “functional” organizations should exist. We hypothesized that such a transition may lie in LO-1 or LO-2, two visual areas lying between retinotopically defined V3d and functionally defined LO. Using a rapid event-related fMRI paradigm, we measured neural similarity in 12 human participants between pairs of stimuli differing along dimensions of shape exemplar and shape complexity within both retinotopically and functionally defined visual areas. These neural similarity measures were then compared with low-level and more abstract (curvature-based) measures of stimulus similarity. We found that low-level, but not abstract, stimulus measures predicted V1–V3 responses, whereas the converse was true for LO, a double dissociation. Critically, abstract stimulus measures were most predictive of responses within LO-2, akin to LO, whereas both low-level and abstract measures were predictive for responses within LO-1, perhaps indicating a transitional point between those two organizational principles. Similar transitions to abstract representations were not observed in the more ventral stream passing through V4 and VO-1/2. The transition we observed in LO-1 and LO-2 demonstrates that a more “abstracted” representation, typically considered the preserve of “category-selective” extrastriate cortex, can nevertheless emerge in retinotopic regions

    A Direct Demonstration of Functional Differences between Subdivisions of Human V5/MT

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    Two subdivisions of human V5/MT+: one located posteriorly (MT/TO-1) and the other more anteriorly (MST/TO-2) were identified in human participants using functional magnetic resonance imaging on the basis of their representations of the ipsilateral versus contralateral visual field. These subdivisions were then targeted for disruption by the application of repetitive transcranial magnetic stimulation (rTMS). The rTMS was delivered to cortical areas while participants performed direction discrimination tasks involving 3 different types of moving stimuli defined by the translational, radial, or rotational motion of dot patterns. For translational motion, performance was significantly reduced relative to baseline when rTMS was applied to both MT/TO-1 and MST/TO-2. For radial motion, there was a differential effect between MT/TO-1 and MST/TO-2, with only disruption of the latter area affecting performance. The rTMS failed to reveal a complete dissociation between MT/TO-1 and MST/TO-2 in terms of their contribution to the perception of rotational motion. On the basis of these results, MT/TO-1 and MST/TO-2 appear to be functionally distinct subdivisions of hV5/MT+. While both areas appear to be implicated in the processing of translational motion, only the anterior region (MST/TO-2) makes a causal contribution to the perception of radial motion
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