248 research outputs found

    Mirror-image relations in category learning

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    The discrimination of patterns that are mirror-symmetric counterparts of each other is difficult and requires substantial training. We explored whether mirror-image discrimination during expertise acquisition is based on associative learning strategies or involves a representational shift towards configural pattern descriptions that permit resolution of symmetry relations. Subjects were trained to discriminate between sets of unfamiliar grey-level patterns in two conditions, which either required the separation of mirror images or not. Both groups were subsequently tested in a 4-class category-learning task employing the same set of stimuli. The results show that subjects who had successfully learned to discriminate between mirror-symmetric counterparts were distinctly faster in the categorization task, indicating a transfer of conceptual knowledge between the two tasks. Additional computer simulations suggest that the development of such symmetry concepts involves the construction of configural, protoholistic descriptions, in which positions of pattern parts are encoded relative to a spatial frame of reference

    ‘Engage the World’: examining conflicts of engagement in public museums

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    Public engagement has become a central theme in the mission statements of many cultural institutions, and in scholarly research into museums and heritage. Engagement has emerged as the go-to-it-word for generating, improving or repairing relations between museums and society at large. But engagement is frequently an unexamined term that might embed assumptions and ignore power relationships. This article describes and examines the implications of conflicting and misleading uses of ‘engagement’ in relation to institutional dealings with contested questions about culture and heritage. It considers the development of an exhibition on the Dead Sea Scrolls by the Royal Ontario Museum, Toronto in 2009 within the new institutional goal to ‘Engage the World’. The chapter analyses the motivations, processes and decisions deployed by management and staff to ‘Engage the World’, and the degree to which the museum was able to re-think its strategies of public engagement, especially in relation to subjects,issues and publics that were more controversial in nature

    Spin dynamics in molecular ring nanomagnets: Significant effect of acoustic phonons and magnetic anisotropies

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    The nuclear spin-lattice relaxation rate 1/T_1_ is calculated for magnetic ring clusters by fully diagonalizing their microscopic spin Hamiltonians. Whether the nearest-neighbor exchange interaction J is ferromagnetic or antiferromagnetic, 1/T_1_ versus temperature T in ring nanomagnets may be peaked at around k_B_T=|J| provided the lifetime broadening of discrete energy levels is in proportion to T^3^. Experimental findings for ferromagnetic and antiferromagnetic Cu^II^ rings are reproduced with crucial contributions of magnetic anisotropies as well as acoustic phonons.Comment: 5 pages with 5 figures embedded, to be published in J. Phys. Soc. Jpn. 75, No. 10 (2006

    Affine modifications and affine hypersurfaces with a very transitive automorphism group

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    We study a kind of modification of an affine domain which produces another affine domain. First appeared in passing in the basic paper of O. Zariski (1942), it was further considered by E.D. Davis (1967). The first named author applied its geometric counterpart to construct contractible smooth affine varieties non-isomorphic to Euclidean spaces. Here we provide certain conditions which guarantee preservation of the topology under a modification. As an application, we show that the group of biregular automorphisms of the affine hypersurface XCk+2X \subset C^{k+2} given by the equation uv=p(x1,...,xk)uv=p(x_1,...,x_k) where pC[x1,...,xk],p \in C[x_1,...,x_k], acts mm-transitively on the smooth part regXX of XX for any mN.m \in N. We present examples of such hypersurfaces diffeomorphic to Euclidean spaces.Comment: 39 Pages, LaTeX; a revised version with minor changes and correction

    Neoliberal anti-racism: Responding to ‘everywhere but different’ racism

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    © 2016, © The Author(s) 2016. Racism cannot be treated as a spatially homogeneous phenomenon. This review reports on the merits of a localized approach to anti-racism, and delivers a frank assessment of the challenges faced when developing local responses to racism in a neoliberal era. Under neoliberalism, local actors are responsibilized, and for anti-racism this means action can potentially be closely aligned to local inflexions of racism. But localized responses to racism under neoliberalism are associated with deracialized and depoliticized policies on interethnic community relations. Neoliberal anti-racism promotes competition among local agencies rather than coalition building, and is associated with spatially uneven and non-strategic action

    The Role of Creativity in Entrepreneurship

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    This paper evaluates the contribution of creativity to entrepreneurship theory and practice in terms of building an holistic and transdisciplinary understanding of its impact. Acknowledgement is made of the subjectivist theory of entrepreneurship which embraces randomness, uncertainty and ambiguity but these factors should then be embedded in wider business and social contexts. The analysis is synthesised into a number of themes, from consideration of its definition, its link with personality and cognitive style, creativity as a process and the use of biography in uncovering data on creative entrepreneurial behaviour. Other relevant areas of discussion include creativity’s link with motivation, actualisation and innovation, as well as the interrogation of entrepreneurial artists as owner/managers. These factors are embedded in a critical evaluation of how creativity contributes to successful entrepreneurship practice. Modelling, measuring and testing entrepreneurial creativity are also considered and the paper includes detailed consideration of several models of creativity in entrepreneurship. Recommendations for future theory and practice are also made

    Domesticating Fears and Fantasies of ‘the East’: integrating the Ottoman legacy within European heritage

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    'Europe' has no fixed geographical, historical, religious or cultural boundaries. Claims for the existence of European civilization as a discrete construct are continually made yet dissolve on close scrutiny. Here, we examine these claims at one of the grandest points of existential crisis and belonging for Europe, the relationship with the 'Other within': Turkey, the Balkans and Ottoman heritage in Europe. Through a hybrid semiotic and Foucauldian analysis of catalogues of eight high-profile exhibitions in the United Kingdom, Turkey, Belgium and Portugal we argue that an unsettled discursive struggle is at play, in which one 'Europe' articulates 'reconciliation' of profound civilizational difference while another, Ottoman, 'Europe' stakes a claim of right as an intrinsic component of what it means to be European in a contemporary context. We attempt to trace the role of museum marketing in the perennial accommodation/exclusion of the Ottoman Empire as an intrinsic component in the diversity of Europe’s cultural heritage

    A quantitative analysis of the effect of cycle length on arrhythmogenicity in hypokalaemic Langendorff-perfused murine hearts

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    The clinically established proarrhythmic effect of bradycardia and antiarrhythmic effect of lidocaine (10 μM) were reproduced in hypokalaemic (3.0 mM K+) Langendorff-perfused murine hearts paced over a range (80–180 ms) of baseline cycle lengths (BCLs). Action potential durations (at 90% repolarization, APD90s), transmural conduction times and ventricular effective refractory periods (VERPs) were then determined from monophasic action potential records obtained during a programmed electrical stimulation procedure in which extrasystolic stimuli were interposed following regular stimuli at successively decreasing coupling intervals. A novel graphical analysis of epicardial and endocardial, local and transmural relationships between APD90, corrected for transmural conduction time where appropriate, and VERP yielded predictions in precise agreement with the arrhythmogenic findings obtained over the entire range of BCLs studied. Thus, in normokalaemic (5.2 mM K+) hearts a statistical analysis confirmed that all four relationships were described by straight lines of gradients not significantly (P > 0.05) different from unity that passed through the origin and thus subtended constant critical angles, θ with the abscissa (45.8° ± 0.9°, 46.6° ± 0.5°, 47.6° ± 0.5° and 44.9° ± 0.8°, respectively). Hypokalaemia shifted all points to the left of these reference lines, significantly (P < 0.05) increasing θ at BCLs of 80–120 ms where arrhythmic activity was not observed (∼63°, ∼54°, ∼55° and ∼58°, respectively) and further significantly (P < 0.05) increasing θ at BCLs of 140–180 ms where arrhythmic activity was observed (∼68°, ∼60°, ∼61° and ∼65°, respectively). In contrast, the antiarrhythmic effect of lidocaine treatment was accompanied by a significant (P < 0.05) disruption of this linear relationship and decreases in θ in both normokalaemic (∼40°, ∼33°, ∼39° and ∼41°, respectively) and hypokalaemic (∼40°, ∼44°, ∼50° and ∼48°, respectively) hearts. This extended a previous approach that had correlated alterations in transmural repolarization gradients with arrhythmogenicity in murine models of the congenital long QT syndrome type 3 and hypokalaemia at a single BCL. Thus, the analysis in terms of APD90 and VERP provided a more sensitive indication of the effect of lidocaine than one only considering transmural repolarization gradients and may be particularly applicable in physiological and pharmacological situations in which these parameters diverge
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