99 research outputs found

    Measurement of mental attention: Assessing a cognitive component underlying performance on standardized intelligence tests

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    Despite the widespread use of standardized IQ tests to measure human intelligence, problems with such measures have led some to suggest that better indices may derive from measurement of cognitive processes underlying performance on IQ tests (e.g., working memory capacity). However, measures from both approaches may exhibit performance biases in favour of majority groups, due to the influence of prior learning and experience. Mental attentional (M-) capacity is proposed to be a causal factor underlying developmental growth in working memory. Measures of M-capacity index important cognitive variance underlying performance on standardized intelligence tests. These measures appear to be reasonably culture-fair and invariant across content domains. The current study tested theoretical predictions regarding the content-invariance of M-measures and the development of M-capacity for groups of children differing in performance on standardized IQ tests. 91 participants differentiated on the basis of academic stream (intellectually gifted vs. mainstream) and age (grade 4 vs. grade 8) received measures of M-capacity in the verbal and visuo-spatial domains. Children identified as gifted scored about one stage higher on both measures. Results suggest that measures of M-capacity may be useful adjuncts to standardized intelligence measures

    SCFHLA: Un Modelo de Interoperabilidad Semántica para Simulación Distribuida de Cadenas de Suministro

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    La simulación distribuida de cadenas de suministro tiene la gran ventaja de preservar la independencia de los miembros de la cadena, pudiendo reutilizar simuladores existentes sin necesidad de crear uno nuevo. Sin embargo, el problema que emerge en este tipo de simulación es la necesidad de acordar el conjunto de objetos, eventos, interacciones y métricas, que deben ser entendidas por todos los participantes para lograr con éxito un resultado valioso para los mismos. En este trabajo se presenta un marco conceptual basado en una red de ontologías, que da soporte a las tareas de modelado y composición de la simulación distribuida de cadenas de suministro para garantizar la interoperabilidad semántica de sus miembros. Se utiliza el estándar HLA (High Level Architecture) como herramienta de construcción de una simulación distribuida.Fil: Sarli, Juan Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Leone, Horacio Pascual. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Guitierrez, Maria de los Milagros. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Centro de Investigación y Desarrollo de Ingeniería en Sistemas de Información; Argentin

    Measurement of mental attention: Assessing a cognitive component underlying performance on

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    Abstract Despite the widespread use of standardized IQ tests to measure human intelligence, problems with such measures have led some to suggest that better indices may derive from measurement of cognitive processes underlying performance on IQ tests (e.g., working memory capacity). However, measures from both approaches may exhibit performance biases in favour of majority groups, due to the influence of prior learning and experience. Mental attentional (M-) capacity is proposed to be a causal factor underlying developmental growth in working memory. Measures of M-capacity index important cognitive variance underlying performance on standardized intelligence tests. These measures appear to be reasonably culture-fair and invariant across content domains. The current study tested theoretical predictions regarding the content-invariance of M-measures and the development of M-capacity for groups of children differing in performance on standardized IQ tests. Ninety-one participants differentiated on the basis of academic stream (intellectually gifted vs. mainstream) and age (grade 4 vs. grade 8) received measures of M-capacity in the verbal and visuo-spatial domains. Children identified as gifted scored about one stage higher on both measures. Results suggest that measures of M-capacity may be useful adjuncts to standardized intelligence measures

    Sesión Necrológica en Homenaje al Excmo. Sr. Don Eduardo Primo Yúfera

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    The Dr. Eduardo Primo Yúfera was born on April 1, 1918 in Mazarrón, Murcia. Took possession as Academician of Honor on December 12, 2002. Died on October 28, 2007. The Necrological Session was celebrated on April 17, 2008, coordinated by the Academic Ana M ª Pascual-Leone Pascual, Vice-president of the Royal National Academy of Pharmacy, with the intervention of the Prof- Jose Pío Beltrán Porter, D. Vicente Conejero Tomás, D. Juan Juliá Igual and the Academic Ana M ª Pascual-Leone Pascual. It was presided by the Academic Maria Teresa Miras Portugal, Chairwoman of the Royal National Academy of Pharmacy.El Excmo. Señor Don Eduardo Primo Yúfera nació el 1 de abril de 1918 en Mazarrón, Murcia. Tomó posesión como Académico de Honor el día 12 de diciembre de 2002. Falleció el día 28 de octubre de 2007. La Sesión Necrológica se celebró el día 17 de abril de 2008, coordinada por la Excma. Sra. Dña. Ana Mª Pascual-Leone Pascual, Vicepresidenta de la Real Academia Nacional de Farmacia, con la intervención de los señores D. José Pío Beltrán Porter, D. Vicente Conejero Tomás, D. Juan Juliá Igual y de la Excma. Sra. Dña. Ana Mª Pascual-Leone Pascual. Fue presidida por la Excma. Señora Doña María Teresa Miras Portugal, Presidenta de la Real Academia Nacional de Farmacia

    Recommendations of the Spanish Antibiogram Committee (COESANT) for selecting antimicrobial agents and concentrations for in vitro susceptibility studies using automated systems

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    Automated antimicrobial susceptibility testing devices are widely implemented in clinical microbiology laboratories in Spain, mainly using EUCAST (European Committee on Antimicrobial Susceptibility Testing) breakpoints. In 2007, a group of experts published recommendations for including antimicrobial agents and selecting concentrations in these systems. Under the patronage of the Spanish Antibiogram Committee (Comité Español del Antibiograma, COESANT) and the Study Group on Mechanisms of Action and Resistance to Antimicrobial Agents (GEMARA) from the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), and aligned with the Spanish National Plan against Antimicrobial Resistance (PRAN), a group of experts have updated this document. The main modifications from the previous version comprise the inclusion of new antimicrobial agents, adaptation of the ranges of concentrations to cover the EUCAST breakpoints and epidemiological cut-off values (ECOFFs), and the inference of new resistance mechanisms. This proposal should be considered by different manufacturers and users when designing new panels or cards. In addition, recommendations for selective reporting are also included. With this approach, the implementation of EUCAST breakpoints will be easier, increasing the quality of antimicrobial susceptibility testing data and their microbiological interpretation. It will also benefit epidemiological surveillance studies as well as the clinical use of antimicrobials aligned with antimicrobial stewardship programs.Los sistemas automáticos utilizados en el estudio de la sensibilidad a los antimicrobianos están introducidos en la mayoría de los laboratorios de Microbiología Clínica en España, utilizando principalmente los puntos de corte del European Committee on Antimicrobial Susceptibility Testing (EUCAST). En 2007, un grupo de expertos publicó unas recomendaciones para incluir antimicrobianos y seleccionar concentraciones en estos sistemas. Bajo el auspicio del Comité Español del Antibiograma (COESANT) y del Grupo de Estudio de los Mecanismos de Acción y Resistencia a los Antimicrobianos (GEMARA) de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEIMC) y alineado con el Plan Nacional frente a la Resistencia a los Antibióticos (PRAN), un grupo de expertos ha actualizado dicho documento. Las principales modificaciones realizadas sobre la versión anterior comprenden la inclusión de nuevos agentes antimicrobianos, la adaptación de los rangos de concentraciones para cubrir los puntos de corte clínicos y los puntos de corte epidemiológicos (ECOFF) definidos por el EUCAST, y para la inferencia de nuevos mecanismos de resistencia. Esta propuesta debería ser considerada por los diferentes fabricantes y los usuarios cuando se diseñen nuevos paneles o tarjetas. Además, se incluyen recomendaciones para realizar informes selectivos. Con este enfoque, la implementación de los puntos de corte del EUCAST será más fácil, aumentando la calidad de los datos del antibiograma y su interpretación microbiológica. También será de utilidad para los estudios de vigilancia epidemiológica, así como para el uso clínico de los antimicrobianos, de acuerdo con los programas de optimización de uso de antimicrobianos (PROA)

    Transcranial magnetic stimulation (TMS) inhibits cortical dendrites

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    One of the leading approaches to non-invasively treat a variety of brain disorders is transcranial magnetic stimulation (TMS). However, despite its clinical prevalence, very little is known about the action of TMS at the cellular level let alone what effect it might have at the subcellular level (e.g. dendrites). Here, we examine the effect of single-pulse TMS on dendritic activity in layer 5 pyramidal neurons of the somatosensory cortex using an optical fiber imaging approach. We find that TMS causes GABAB-mediated inhibition of sensory-evoked dendritic Ca(2+) activity. We conclude that TMS directly activates fibers within the upper cortical layers that leads to the activation of dendrite-targeting inhibitory neurons which in turn suppress dendritic Ca(2+) activity. This result implies a specificity of TMS at the dendritic level that could in principle be exploited for investigating these structures non-invasively

    Why is “blindsight” blind? A new perspective on primary visual cortex, recurrent activity and visual awareness

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    The neuropsychological phenomenon of blindsight has been taken to suggest that the primary visual cortex (V1) plays a unique role in visual awareness, and that extrastriate activation needs to be fed back to V1 in order for the content of that activation to be consciously perceived. The aim of this review is to evaluate this theoretical framework and to revisit its key tenets. Firstly, is blindsight truly a dissociation of awareness and visual detection? Secondly, is there sufficient evidence to rule out the possibility that the loss of awareness resulting from a V1 lesion simply reflects reduced extrastriate responsiveness, rather than a unique role of V1 in conscious experience? Evaluation of these arguments and the empirical evidence leads to the conclusion that the loss of phenomenal awareness in blindsight may not be due to feedback activity in V1 being the hallmark awareness. On the basis of existing literature, an alternative explanation of blindsight is proposed. In this view, visual awareness is a “global” cognitive function as its hallmark is the availability of information to a large number of perceptual and cognitive systems; this requires inter-areal long-range synchronous oscillatory activity. For these oscillations to arise, a specific temporal profile of neuronal activity is required, which is established through recurrent feedback activity involving V1 and the extrastriate cortex. When V1 is lesioned, the loss of recurrent activity prevents inter-areal networks on the basis of oscillatory activity. However, as limited amount of input can reach extrastriate cortex and some extrastriate neuronal selectivity is preserved, computations involving comparison of neural firing rates within a cortical area remain possible. This enables “local” read-out from specific brain regions, allowing for the detection and discrimination of basic visual attributes. Thus blindsight is blind due to lack of “global” long-range synchrony, and it functions via “local” neural readout from extrastriate areas

    Distributed representations of the "preparatory set" in the frontal oculomotor system: a TMS study

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    <p>Abstract</p> <p>Background</p> <p>The generation of saccades is influenced by the level of "preparatory set activity" in cortical oculomotor areas. This preparatory activity can be examined using the gap-paradigm in which a temporal gap is introduced between the disappearance of a central fixation target and the appearance of an eccentric target.</p> <p>Methods</p> <p>Ten healthy subjects made horizontal pro- or antisaccades in response to lateralized cues after a gap period of 200 ms. Single-pulse transcranial magnetic stimulation (TMS) was applied to the dorsolateral prefrontal cortex (DLPFC), frontal eye field (FEF), or supplementary eye field (SEF) of the right hemisphere 100 or 200 ms after the disappearance of the fixation point. Saccade latencies were measured to probe the disruptive effect of TMS on saccade preparation. In six individuals, we gave realistic sham TMS during the gap period to mimic auditory and somatosensory stimulation without stimulating the cortex.</p> <p>Results</p> <p>TMS to DLPFC, FEF, or SEF increased the latencies of contraversive pro- and antisaccades. This TMS-induced delay of saccade initiation was particularly evident in conditions with a relatively high level of preparatory set activity: The increase in saccade latency was more pronounced at the end of the gap period and when participants prepared for prosaccades rather than antisaccades. Although the "lesion effect" of TMS was stronger with prefrontal TMS, TMS to FEF or SEF also interfered with the initiation of saccades. The delay in saccade onset induced by real TMS was not caused by non-specific effects because sham stimulation shortened the latencies of contra- and ipsiversive anti-saccades, presumably due to intersensory facilitation.</p> <p>Conclusion</p> <p>Our results are compatible with the view that the "preparatory set" for contraversive saccades is represented in a distributed cortical network, including the contralateral DLPFC, FEF and SEF.</p

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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