464 research outputs found
Fooling the eyes: the influence of a sound-induced visual motion illusion on eye movements
The question of whether perceptual illusions influence eye movements is critical for the long-standing debate regarding the separation between action and perception. To test the role of auditory context on a visual illusion and on eye movements, we took advantage of the fact that the presence of an auditory cue can successfully modulate illusory motion perception of an otherwise static flickering object (sound-induced visual motion effect). We found that illusory motion perception modulated by an auditory context consistently affected saccadic eye movements. Specifically, the landing positions of saccades performed towards flickering static bars in the periphery were biased in the direction of illusory motion. Moreover, the magnitude of this bias was strongly correlated with the effect size of the perceptual illusion. These results show that both an audio-visual and a purely visual illusion can significantly affect visuo-motor behavior. Our findings are consistent with arguments for a tight link between perception and action in localization tasks
From the fuzzy disc to edge currents in Chern-Simons Theory
We present a brief review of the fuzzy disc, the finite algebra approximating
functions on a disc, which we have introduced earlier. We also present a
comparison with recent papers of Balachandran, Gupta and
K\"urk\c{c}\"{u}o\v{g}lu, and of Pinzul and Stern, aimed at the discussion of
edge states of a Chern-Simons theory.Comment: 8 pages, 6 figures, Talk presented at ``Space-time and Fundamental
Interactions: Quantum Aspects'', conference in honour of A. P. Balachandran's
65th birthday. References added and one misprint correcte
Unexpected Architectures. Restorations in Romagna Between the Two World Wars
The research here presented is a critical appraisal of some restoration works carried out between the two World Wars in a particular geographic context, which is the Romagna district, in the Northeast of Italy. Starting from two case studies (the Casa del Fascio in Forl\uec and the Malatesta Library in Cesena) and thanks to the analysis of bibliographical sources, archival documents, and drawings, this research aims at understanding how broader and major theories about architectural restoration are articulated in peripheral background. What emerges are unexpected results: Late and deeply contextualized operations, strongly linked with the national panorama but at the same time chasing for the revival of their own history
The Schwinger Representation of a Group: Concept and Applications
The concept of the Schwinger Representation of a finite or compact simple Lie
group is set up as a multiplicity-free direct sum of all the unitary
irreducible representations of the group. This is abstracted from the
properties of the Schwinger oscillator construction for SU(2), and its
relevance in several quantum mechanical contexts is highlighted. The Schwinger
representations for and SU(n) for all are constructed via
specific carrier spaces and group actions. In the SU(2) case connections to the
oscillator construction and to Majorana's theorem on pure states for any spin
are worked out. The role of the Schwinger Representation in setting up the
Wigner-Weyl isomorphism for quantum mechanics on a compact simple Lie group is
brought out.Comment: Latex, 17 page
Topology and quantum states: The electron-monopole system
This paper starts by describing the dynamics of the electronmonopole system at both classical and quantum level by a suitable reduction procedure. This suggests, in order to realise the space of states for quantum systems which are classically described on topologically non-trivial configuration spaces, to consider Hilbert spaces of exterior differential forms. Among the advantages of this
formulation, we presentâin the case of the group SU(2), how it is possible to obtain all unitary irreducible representations on such a Hilbert space, and how it is possible to write scalar Dirac-type operators, following an idea by Kšahler
Geometry of the Gauge Algebra in Noncommutative Yang-Mills Theory
A detailed description of the infinite-dimensional Lie algebra of star-gauge
transformations in noncommutative Yang-Mills theory is presented. Various
descriptions of this algebra are given in terms of inner automorphisms of the
underlying deformed algebra of functions on spacetime, of deformed symplectic
diffeomorphisms, of the infinite unitary Lie algebra, and of the algebra of
compact operators on a quantum mechanical Hilbert space. The spacetime and
string interpretations are also elucidated.Comment: 49 pages LaTeX; v2: References added; v3: Typos corrected and
references added; final version published in JHE
Noncommutative differential calculus for Moyal subalgebras
We build a differential calculus for subalgebras of the Moyal algebra on R^4
starting from a redundant differential calculus on the Moyal algebra, which is
suitable for reduction. In some cases we find a frame of 1-forms which allows
to realize the complex of forms as a tensor product of the noncommutative
subalgebras with the external algebra Lambda^*.Comment: 13 pages, no figures. One reference added, minor correction
The beat of a fuzzy drum: fuzzy Bessel functions for the disc
The fuzzy disc is a matrix approximation of the functions on a disc which
preserves rotational symmetry. In this paper we introduce a basis for the
algebra of functions on the fuzzy disc in terms of the eigenfunctions of a
properly defined fuzzy Laplacian. In the commutative limit they tend to the
eigenfunctions of the ordinary Laplacian on the disc, i.e. Bessel functions of
the first kind, thus deserving the name of fuzzy Bessel functions.Comment: 30 pages, 8 figure
Expression patterns of cytokines, p53 and nitric oxide synthase enzymes in corpora lutea of pseudopregnant rabbits during spontaneous luteolysis
The gene expressions for macrophage chemoattractant protein-1 (MCP-1), interleukin (IL)-1 beta, IL-2 and p53 were examined by semi-quantitative RT-PCR in corpora lutea (CL) of rabbits during spontaneous luteolysis at days 13, 15, 18 and 22 of pseudopregnancy. In the same luteal tissue, total activity of nitric oxide (NO) synthase (NOS) and genes for both endothelial (eNOS) and inducible (iNOS) isoforms were also analysed. From day 13 to 15, MCP-1 and IL-1 beta mRNA levels rose (P < or = 0.01) almost 2-fold, and the transcript for p53 almost 8-fold, but then all dropped (P < or = 0.05) from day 18 onward. IL-2 mRNA abundance was higher (P < or = 0.01) on day 13 and then gradually declined. During luteolysis, eNOS mRNA decreased 40% (P < or = 0.05) by day 15, but thereafter remained unchanged, while iNOS mRNA was barely detectable and did not show any clear age-related pattern throughout the late luteal stages. Total NOS activity progressively increased (P < or = 0.01) from day 13 to 18 of pseudopregnancy and then dropped to the lowest (P < or = 0.01) levels on day 22. Luteal progesterone content also declined during CL regression from 411 to 17 pg/mg found on days 13 and 22 respectively, in parallel with the decrease in blood progesterone concentrations. These data further support a physiological role of NO as modulator of luteal demise in rabbits. Locally, luteal cytokines may be involved in the up-regulation of NOS activity, while downstream NO may inhibit steroroidogenesis and induce expression of p53 gene after removal of the protective action of progesterone
DISCOVERING AND PRESERVING THE MILITARY LANDSCAPE. ICT FOR THE GERMAN BUNKERS OF THE GALLA PLACIDIA LINE
The research here presented reflects on the potentials of enhancement, given by new Information and Communication technologies, in the field of Culture Heritage. It describes an interpretation and communication project for a military landscape built during World War II by the German troops. Known as Galla Placidia Line, it was a network of heterogeneous fortifications like bunkers, defensive emplacements and dragonâs teeth erected between Pesaro and Ravenna along the coasts of Emilia Romagna.The project bases its roots on the development of a rigorous census, thought as an implementation of the online open-source catalogue established by the entrusted Institutions. The direct and indirect surveys required in order to describe these structures according to a specific set of characteristics will increase their knowledge and relative awareness and it will constitute the starting point for developing new narrative contents. The communication and interpretation of these data will go through the use of locating intelligences â an integrated GPS and Beacon system â involved into a new application. A tool witch is meant to help and empower local communities and institutions not only in making this heritage known but also in its conservation policies.</p
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