15,822 research outputs found
Differential Impact of Interference on Internally- and Externally-Directed Attention.
Attention can be oriented externally to the environment or internally to the mind, and can be derailed by interference from irrelevant information originating from either external or internal sources. However, few studies have explored the nature and underlying mechanisms of the interaction between different attentional orientations and different sources of interference. We investigated how externally- and internally-directed attention was impacted by external distraction, how this modulated internal distraction, and whether these interactions were affected by healthy aging. Healthy younger and older adults performed both an externally-oriented visual detection task and an internally-oriented mental rotation task, performed with and without auditory sound delivered through headphones. We found that the addition of auditory sound induced a significant decrease in task performance in both younger and older adults on the visual discrimination task, and this was accompanied by a shift in the type of distractions reported (from internal to external). On the internally-oriented task, auditory sound only affected performance in older adults. These results suggest that the impact of external distractions differentially impacts performance on tasks with internal, as opposed to external, attentional orientations. Further, internal distractibility is affected by the presence of external sound and increased suppression of internal distraction
Effects of somatostatin on calcitonin and ectopic ACTH release in a patient with medullary thyroid carcinoma
Early-type Galaxies in the Cluster Abell 2390 at z=0.23
To examine the evolution of the early-type galaxy population in the rich
cluster Abell 2390 at z=0.23 we have gained spectroscopic data of 51 elliptical
and lenticular galaxies with MOSCA at the 3.5 m telescope on Calar Alto
Observatory. This investigation spans both a broad range in luminosity
(-19.3>M_B>-22.3) and uses a wide field of view of 10'x10', therefore the
environmental dependence of different formation scenarios can be analysed in
detail as a function of radius from the cluster centre. Here we present results
on the surface brightness modelling of galaxies where morphological and
structural information is available in the F814W filter aboard the Hubble Space
Telescope (HST) and investigate for this subsample the evolution of the
Fundamental Plane.Comment: 5 pages, 5 figures, to appear in "Carnegie Observatories Astrophysics
Series, Vol. 3: Clusters of Galaxies: Probes of Cosmological Structure and
Galaxy Evolution", ed. J. S. Mulchaey, A. Dressler, and A. Oemler (Pasadena:
Carnegie Observatories,
http://www.ociw.edu/ociw/symposia/series/symposium3/proceedings.html
A Frictional Cooling Demonstration Experiment with Protons
Muon cooling is the main technological obstacle in the building of a muon
collider. A muon cooling scheme based on Frictional Cooling holds promise in
overcoming this obstacle. An experiment designed to demonstrate the Frictional
Cooling concept using protons was undertaken. Although the results were
inconclusive in the observation of cooling, the data allowed for the
qualification of detailed simulations which are used to simulate the
performance of a muon collider.Comment: 24 Pages 16 figures 2 table
Scanning tunneling microscopy and kinetic Monte Carlo investigation of Cesium superlattices on Ag(111)
Cesium adsorption structures on Ag(111) were characterized in a
low-temperature scanning tunneling microscopy experiment. At low coverages,
atomic resolution of individual Cs atoms is occasionally suppressed in regions
of an otherwise hexagonally ordered adsorbate film on terraces. Close to step
edges Cs atoms appear as elongated protrusions along the step edge direction.
At higher coverages, Cs superstructures with atomically resolved hexagonal
lattices are observed. Kinetic Monte Carlo simulations model the observed
adsorbate structures on a qualitative level.Comment: 8 pages, 7 figure
¿Conflictos en la integración regional? Consideraciones acerca de la superposición de los acuerdos internacionales de inversión, los acuerdos comerciales regionales y la OMC
La creciente interdependencia económica internacional resultó en el desarrollo de diversas organizaciones y acuerdos regionales como los acuerdos comerciales regionales, los acuerdos internacionales de inversión y la Organización Mundial de Comercio (omc). En el panorama actual, diversos países son miembros de estos acuerdos y organizaciones concomitantemente. El gran incremento de los resultados de soluciones de diferencias debido al éxito del Entendimiento sobre Solución de Diferencias (esd) de la omc y el crecimiento paralelo del uso de las provisiones de los aii sobre solución de diferencias entre Estados e inversores llevaron a afirmaciones sobre el distanciamiento del derecho internacional de las inversiones y el derecho internacional comercial, lo que podría generar problemas con relación a la coherencia y estabilidad del derecho económico
Equivalence of domains for hyperbolic Hubbard-Stratonovich transformations
We settle a long standing issue concerning the traditional derivation of
non-compact non-linear sigma models in the theory of disordered electron
systems: the hyperbolic Hubbard-Stratonovich (HS) transformation of
Pruisken-Schaefer type. Only recently the validity of such transformations was
proved in the case of U(p,q) (non-compact unitary) and O(p,q) (non-compact
orthogonal) symmetry. In this article we give a proof for general non-compact
symmetry groups. Moreover we show that the Pruisken-Schaefer type
transformations are related to other variants of the HS transformation by
deformation of the domain of integration. In particular we clarify the origin
of surprising sign factors which were recently discovered in the case of
orthogonal symmetry.Comment: 30 pages, 3 figure
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