3,953 research outputs found

    Conflict on high: Tthe Bolivian Revolution and the United States, 1961-1964.

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    Despite receiving massive injections of US foreign aid in 1961-1964, Bolivia has so far escaped the attention of scholars of American foreign policy toward Latin America during early 1960s. Yet only a thorough analysis of the Alliance for Progress in Bolivia can properly account for the reasons why the highest per capita recipient of Alliance aid funds entered a long period of military rule on 4 November 1964. Most previous accounts have blamed the military coup on the CIA, or the Pentagon, thus acquitting Kennedy-era aid programs of any complicity. This thesis argues that, on the contrary, Alliance programs played the central role in building up the Bolivian armed forces, both through civic action programs in the countryside and harsh labor reforms that were implemented through military force. The narrative suggests that aggressive ideologies of Third World development can often fuel geostrategic foreign interventions that rely heavily on authoritarian regimes. Rather than being a work of US imperialism, the following narrative suggests that the 1964 coup d'etat was actually a reaction against the heavy-hand wielded by the politicized intervention represented by Kennedy's Alliance for Progress

    Book Review: Thomas C. Field, Jr. From Development to Dictatorship: Bolivia and the Alliance for Progress in the Kennedy Era.

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    This document offers reviews and discussion of Thomas C. Field, Jr.’s book From Development to Dictatorship: Bolivia and the Alliance for Progress in the Kennedy Era. Ithaca: Cornell University Press, 2014. ISBN: 978-0-8014-5260-4 (hardcover, $45.00)

    Book Review: Christopher Darnton. Rivalry and Alliance Politics in Cold War Latin America

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    This document includes Dr. Field\u27s review of Christopher Darnton\u27s Rivalry and Alliance Politics in Cold War Latin America. Baltimore: Johns Hopkins University Press, 2014. ISBN: 9781421413617 (paperback, $44.95). It is part of H-Diplo | ISSF, Roundtable, Volume VIII, No. 8 (2016)

    Homenaje a Gustavo Rodríguez Ostria (1952-2020)

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    Kappa statistic to measure agreement beyond chance in free-response assessments

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    Abstract Background The usual kappa statistic requires that all observations be enumerated. However, in free-response assessments, only positive (or abnormal) findings are notified, but negative (or normal) findings are not. This situation occurs frequently in imaging or other diagnostic studies. We propose here a kappa statistic that is suitable for free-response assessments. Method We derived the equivalent of Cohen’s kappa statistic for two raters under the assumption that the number of possible findings for any given patient is very large, as well as a formula for sampling variance that is applicable to independent observations (for clustered observations, a bootstrap procedure is proposed). The proposed statistic was applied to a real-life dataset, and compared with the common practice of collapsing observations within a finite number of regions of interest. Results The free-response kappa is computed from the total numbers of discordant (b and c) and concordant positive (d) observations made in all patients, as 2d/(b + c + 2d). In 84 full-body magnetic resonance imaging procedures in children that were evaluated by 2 independent raters, the free-response kappa statistic was 0.820. Aggregation of results within regions of interest resulted in overestimation of agreement beyond chance. Conclusions The free-response kappa provides an estimate of agreement beyond chance in situations where only positive findings are reported by raters

    Hysteresis, Avalanches, and Disorder Induced Critical Scaling: A Renormalization Group Approach

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    We study the zero temperature random field Ising model as a model for noise and avalanches in hysteretic systems. Tuning the amount of disorder in the system, we find an ordinary critical point with avalanches on all length scales. Using a mapping to the pure Ising model, we Borel sum the 6ϵ6-\epsilon expansion to O(ϵ5)O(\epsilon^5) for the correlation length exponent. We sketch a new method for directly calculating avalanche exponents, which we perform to O(ϵ)O(\epsilon). Numerical exponents in 3, 4, and 5 dimensions are in good agreement with the analytical predictions.Comment: 134 pages in REVTEX, plus 21 figures. The first two figures can be obtained from the references quoted in their respective figure captions, the remaining 19 figures are supplied separately in uuencoded forma

    Coverage, Continuity and Visual Cortical Architecture

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    The primary visual cortex of many mammals contains a continuous representation of visual space, with a roughly repetitive aperiodic map of orientation preferences superimposed. It was recently found that orientation preference maps (OPMs) obey statistical laws which are apparently invariant among species widely separated in eutherian evolution. Here, we examine whether one of the most prominent models for the optimization of cortical maps, the elastic net (EN) model, can reproduce this common design. The EN model generates representations which optimally trade of stimulus space coverage and map continuity. While this model has been used in numerous studies, no analytical results about the precise layout of the predicted OPMs have been obtained so far. We present a mathematical approach to analytically calculate the cortical representations predicted by the EN model for the joint mapping of stimulus position and orientation. We find that in all previously studied regimes, predicted OPM layouts are perfectly periodic. An unbiased search through the EN parameter space identifies a novel regime of aperiodic OPMs with pinwheel densities lower than found in experiments. In an extreme limit, aperiodic OPMs quantitatively resembling experimental observations emerge. Stabilization of these layouts results from strong nonlocal interactions rather than from a coverage-continuity-compromise. Our results demonstrate that optimization models for stimulus representations dominated by nonlocal suppressive interactions are in principle capable of correctly predicting the common OPM design. They question that visual cortical feature representations can be explained by a coverage-continuity-compromise.Comment: 100 pages, including an Appendix, 21 + 7 figure

    A meta-analytic review of stand-alone interventions to improve body image

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    Objective Numerous stand-alone interventions to improve body image have been developed. The present review used meta-analysis to estimate the effectiveness of such interventions, and to identify the specific change techniques that lead to improvement in body image. Methods The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on improving body image), (b) a control group was used, (c) participants were randomly assigned to conditions, and (d) at least one pretest and one posttest measure of body image was taken. Effect sizes were meta-analysed and moderator analyses were conducted. A taxonomy of 48 change techniques used in interventions targeted at body image was developed; all interventions were coded using this taxonomy. Results The literature search identified 62 tests of interventions (N = 3,846). Interventions produced a small-to-medium improvement in body image (d+ = 0.38), a small-to-medium reduction in beauty ideal internalisation (d+ = -0.37), and a large reduction in social comparison tendencies (d+ = -0.72). However, the effect size for body image was inflated by bias both within and across studies, and was reliable but of small magnitude once corrections for bias were applied. Effect sizes for the other outcomes were no longer reliable once corrections for bias were applied. Several features of the sample, intervention, and methodology moderated intervention effects. Twelve change techniques were associated with improvements in body image, and three techniques were contra-indicated. Conclusions The findings show that interventions engender only small improvements in body image, and underline the need for large-scale, high-quality trials in this area. The review identifies effective techniques that could be deployed in future interventions

    The relationship between a child's postural stability and manual dexterity

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    The neural systems responsible for postural control are separate from the neural substrates that underpin control of the hand. Nonetheless, postural control and eye-hand coordination are linked functionally. For example, a stable platform is required for precise manual control tasks (e.g. handwriting) and thus such skills often cannot develop until the child is able to sit or stand upright. This raises the question of the strength of the empirical relationship between measures of postural stability and manual motor control. We recorded objective computerised measures of postural stability in stance and manual control in sitting in a sample of school children (n = 278) aged 3–11 years in order to explore the extent to which measures of manual skill could be predicted by measures of postural stability. A strong correlation was found across the whole sample between separate measures of postural stability and manual control taken on different days. Following correction for age, a significant but modest correlation was found. Regression analysis with age correction revealed that postural stability accounted for between 1 and 10 % of the variance in manual performance, dependent on the specific manual task. These data reflect an interdependent functional relationship between manual control and postural stability development. Nevertheless, the relatively small proportion of the explained variance is consistent with the anatomically distinct neural architecture that exists for ‘gross’ and ‘fine’ motor control. These data justify the approach of motor batteries that provide separate assessments of postural stability and manual dexterity and have implications for therapeutic intervention in developmental disorders
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