Knowing when to stop: Aberrant precision and evidence accumulation in schizophrenia

Predictive coding and active inference formulations of the dysconnection hypothesis suggest that subjects with schizophrenia (SZ) hold unduly precise prior beliefs to compensate for a failure of sensory attenuation. This implies that SZ subjects should both initiate responses prematurely during evidence-accumulation tasks and fail to inhibit their responses at long stop-signal delays. SZ and healthy control subjects were asked to report the timing of billiards-ball collisions and were occasionally required to withhold their responses. SZ subjects showed larger temporal estimation errors, which were associated with premature responses and decreased response inhibition. To account for these effects, we used hierarchical (Bayesian) drift-diffusion models (HDDM) and model selection procedures to adjudicate among four hypotheses. HDDM revealed that the precision of prior beliefs (i.e., starting point) rather than increased sensory precision (i.e., drift rate) drove premature responses and impaired response inhibition in patients with SZ. From the perspective of active inference, we suggest that premature predictions in SZ are responses that, heuristically, are traded off against accuracy to ensure action execution. On the basis of previous work, we suggest that the right insular cortex might mediate this trade-off

Self-organized criticality in atmospheric cascades

We argue that atmospheric cascades can be regarded as example of the self-organized criticality and studied by using Levy flights and nonextensive approach. It allows us to understand the scale-invariant energy fluctuations inside cascades in a natural way.Comment: gz-compressed .tar file containing LaTeX file and 5 PS files with figures, 4 pages altogether (Nucl. Phys. B style, espcrc2.sty file attached) Presented at XI International Symposium On Very High Energy Cosmic Ray Interaction, Campinas, Brazil, July 17-21, 2000. To be published in Nucl. Phys. B (Proc. Suppl.). Some typos correcte

Everyday cosmopolitanism in representations of Europe among young Romanians in Britain

The paper presents an analysis of everyday cosmopolitanism in constructions of Europe among young Romanian nationals living in Britain. Adopting a social representations approach, cosmopolitanism is understood as a cultural symbolic resource that is part of everyday knowledge. Through a discursively-oriented analysis of focus group data, we explore the ways in which notions of cosmopolitanism intersect with images of Europeanness in the accounts of participants. We show that, for our participants, representations of Europe are anchored in an Orientalist schema of West-vs.-East, whereby the West is seen as epitomising European values of modernity and progress, while the East is seen as backward and traditional. Our findings further show that representations of cosmopolitanism reinforce this East/West dichotomy, within a discourse of ‘Occidental cosmopolitanism’. The paper concludes with a critical discussion of the diverse and complex ideological foundations of these constructions of European cosmopolitanism and their implications

Obesogenic dietary intake in families with 1-year-old infants at high and low obesity risk based on parental weight status: baseline data from a longitudinal intervention (Early STOPP)

PURPOSE: To compare dietary intake in 1-year-old infants and their parents between families with high and low obesity risk, and to explore associations between infant dietary intake and relative weight. METHODS: Baseline analyses of 1-year-old infants (n = 193) and their parents participating in a longitudinal obesity intervention (Early STOPP) were carried out. Dietary intake and diet quality indicators were compared between high- and low-risk families, where obesity risk was based on parental weight status. The odds for high diet quality in relation to parental diet quality were determined. Associations between measured infant relative weight and dietary intake were examined adjusting for obesity risk, socio-demographics, and infant feeding. RESULTS: Infant dietary intake did not differ between high- and low-risk families. The parents in high-risk families consumed soft drinks, French fries, and low-fat spread more frequently, and fish and fruits less frequently (p < 0.05) compared to parents in low-risk families. Paternal intake of vegetables and fish increased the odds for children being consumers of vegetables (OR 1.7; 95 % CI 1.0-2.9) and fish, respectively (OR 2.5; 95 % CI 1.4-4.4). Infant relative weight was weakly associated with a high intake of milk cereal drink (r = 0.15; p < 0.05), but not with any other aspect of dietary intake, obesity risk, or early feeding patterns. CONCLUSIONS: At the age of one, dietary intake in infants is not associated with family obesity risk, nor with parental obesogenic food intake. Milk cereal drink consumption but no other infant dietary marker reflects relative weight at this young age.published_or_final_versio

Corporate ecologies of business travel : working towards a research agenda.

International business travel has always been an important labour process in the accumulation of capital for the firm. It is surprising, therefore, that relatively little time has been devoted to the study of business travel, both as a facet of contemporary mobility and as an economic practice. In this article we review how existing literatures provide insights that can be used to understand the role of business travel as international labour mobility in the contemporary professional service economy. In doing so, we reach the conclusion that there seem to be at least two significant voids preventing a more sophisticated understanding from emerging. First, we suggest that international business travel needs to be studied not in isolation but instead as one component in a wider ecology of mobility which `produces' the global firm. Second, we argue that it is important to know more about the time-space dynamics of international business travel in terms of how spatial relations are produced and reproduced by different forms and geographies of travel. We make these arguments and explore their implications using data collected through interviews in advertising, architecture and legal professional service firms.We conclude by identifying a research agenda designed to allow a better understanding of business travel to emerge in corporate and mobility discourses

The use of carbon monoxide as a probe molecule in spectroscopic studies for determination of exposed gold sites on TiO2

The sol immobilisation technique, in which a stabilising ligand (such as polyvinyl alcohol or polyvinyl pyridine) can be used to tune metal particle size and composition, has become a valuable method of making supported nanoparticle catalysts. An unfortunate consequence of the stabilising ligand is that often access of reactant molecules to the metal nanoparticle surface is impeded. Several methods have been proposed for the removal of these ligands, though determination of the degree of their success is difficult. Here, we demonstrate the use of in situ infrared and UV-Vis spectroscopy to elucidate the access of carbon monoxide to the surface of Au/TiO2 catalysts before and after various ligand removal treatments. These were contrasted with a catalyst prepared by deposition precipitation prepared in the absence of stabilising ligand as a control. Changes were observed in the infrared spectrum, with the wavenumber of carbon monoxide linearly bonded to Au for catalysts shifting before and after ligand removal, which correlated well with the activity of the catalyst for carbon monoxide oxidation. Also the extent of shifting of the Au surface resonance plasmon band on the addition of carbon monoxide, observed by UV-Vis, also correlated well with catalyst activity. These simple methods can be used to determine the quantity of exposed metal sites after a ligand removal treatment and so determine the treatments effectiveness

Supported bimetallic nano-alloys as highly active catalysts for the one-pot tandem synthesis of imines and secondary amines from nitrobenzene and alcohols

The synthesis and functionalization of imines and amines are key steps in the preparation of many fine chemicals and for pharmaceuticals in particular. Traditionally, metal complexes are used as homogeneous catalysts for these organic transformations. Here we report gold-palladium and ruthenium-palladium nano-alloys supported on TiO2 acting as highly efficient heterogeneous catalysts for the one-pot synthesis of the imine N-benzylideneaniline and the secondary amine N-benzylaniline directly from the easily available and stable nitrobenzene and benzyl alcohol precursors using a hydrogen auto-transfer strategy. These reactions were carried out without any added external hydrogen, sacrificial hydrogen donor or a homogeneous base. The bimetallic catalysts were prepared by the recently developed modified impregnation strategy, giving efficient control of size and nano-alloy composition. Both bimetallic catalysts were found to be far more active than their monometallic analogues due to a synergistic effect. Based on the turnover numbers the catalytic activities follow the order Ru < Pd < Au << Au-Pd < Ru-Pd. Aberration corrected scanning transmission electron microscopy (AC-STEM) and X-ray absorption spectroscopy (XAFS) studies of these catalysts revealed that the reason for the observed synergistic effect is the electronic modification of the metal sites in the case of the Au-Pd system and a size stabilisation effect in the case of the Ru-Pd catalyst

Bourdieu’s theory of practice in the study of cultural encounters and transnational transfers in migration

This working paper provides the theoretical reflections and research objectives of the ongoing project Transforming Migration: Transnational Transfer of Multicultural Habitus. It develops the proposal of applying Bourdieu’s theory of practice in studying intercultural skills of migrants and the mechanisms of their transfer to the space of origin of migrants. Conceptual merits and challenges of working with Bourdieu’s intellectual heritage are discussed and illustrated with preliminary results from the project’s first phase. The paper argues that Bourdieu’s theory allows us to see the dispositions, attitudes, worldviews and practices that people display as processes rather than individual qualities, which need to be considered within a complex system of power relations between migrants, their host societies, and their transnationally spanning social networks