8,673 research outputs found

    ADHD patients fail to maintain task goals in face of subliminally and consciously induced cognitive conflicts

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    Background. Attention deficit hyperactivity disorder (ADHD) patients have been reported to display deficits in action control processes. While it is known that subliminally and consciously induced conflicts interact and conjointly modulate action control in healthy subjects, this has never been investigated for ADHD. Method. We investigated the (potential) interaction of subliminally and consciously triggered response conflicts in children with ADHD and matched healthy controls using neuropsychological methods (event-related potentials; ERPs) to identify the involved cognitive sub-processes. Results. Unlike healthy controls, ADHD patients showed no interaction of subliminally and consciously triggered response conflicts. Instead, they only showed additive effects as their behavioural performance (accuracy) was equally impaired by each conflict and they showed no signs of task-goal shielding even in cases of low conflict load. Of note, this difference between ADHD and controls was not rooted in early bottom-up attentional stimulus processing as reflected by the P1 and N1 ERPs. Instead, ADHD showed either no or reversed modulations of conflict-related processes and response selection as reflected by the N2 and P3 ERPs. Conclusion. There are fundamental differences in the architecture of cognitive control which might be of use for future diagnostic procedures. Unlike healthy controls, ADHD patients do not seem to be endowed with a threshold which allows them to maintain high behavioural performance in the face of low conflict load. ADHD patients seem to lack sufficient top-down attentional resources to maintain correct response selection in the face of conflicts by shielding the response selection process from response tendencies evoked by any kind of distractor

    Online Pattern Recognition for the ALICE High Level Trigger

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    The ALICE High Level Trigger has to process data online, in order to select interesting (sub)events, or to compress data efficiently by modeling techniques.Focusing on the main data source, the Time Projection Chamber (TPC), we present two pattern recognition methods under investigation: a sequential approach "cluster finder" and "track follower") and an iterative approach ("track candidate finder" and "cluster deconvoluter"). We show, that the former is suited for pp and low multiplicity PbPb collisions, whereas the latter might be applicable for high multiplicity PbPb collisions, if it turns out, that more than 8000 charged particles would have to be reconstructed inside the TPC. Based on the developed tracking schemes we show, that using modeling techniques a compression factor of around 10 might be achievableComment: Realtime Conference 2003, Montreal, Canada to be published in IEEE Transactions on Nuclear Science (TNS), 6 pages, 8 figure

    Generalized Pseudopotentials for Higher Partial Wave Scattering

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    We derive a generalized zero-range pseudopotential applicable to all partial wave solutions to the Schroedinger equation based on a delta-shell potential in the limit that the shell radius approaches zero. This properly models all higher order multipole moments not accounted for with a monopolar delta function at the origin, as used in the familiar Fermi pseudopotential for s-wave scattering. By making the strength of the potential energy dependent, we derive self-consistent solutions for the entire energy spectrum of the realistic potential. We apply this to study two particles in an isotropic harmonic trap, interacting through a central potential, and derive analytic expressions for the energy eigenstates and eigenvalues.Comment: RevTeX 4 pages, 1 figure, final published versio

    Group behavior among model bacteria influences particulate carbon remineralization depths

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    Organic particles sinking from the sunlit surface are oases of food for heterotrophic bacteria living in the deep ocean. Particle-attached bacteria need to solubilize particles, so they produce exoenzymes that cleave bonds to make molecules small enough to be transported through bacterial cell walls. Releasing exoenzymes, which have an energetic cost, to the external environment is risky because there is no guarantee that products of exoenzyme activity, called hydrolysate, will diffuse to the particle-attached bacterium that produced the exoenzymes. Strategies used by particle-attached bacteria to counteract diffusive losses of exoenzymes and hydrolysate are investigated in a water column model. We find that production of exoenzymes by particle-attached bacteria is only energetically worthwhile at high bacterial abundances. Quorum sensing provides the means to determine local abundances, and thus the model results support lab and field studies which found that particle-attached bacteria have the ability to use quorum sensing. Additional model results are that particle-attached bacterial production is sensitive to diffusion of hydrolysate from the particle and is enhanced by as much as 15 times when diffusion of exoenzymes and hydrolysate from particles is reduced by barriers of biofilms and particle-attached bacteria. Bacterial colonization rates and activities on particles in both the euphotic and mesopelagic zones impact remineralization length scales. Shoaling or deepening of the remineralization depth has been shown to exert significant influence on the residence time and concentration of carbon in the atmosphere and ocean. By linking variability in remineralization depths to mechanisms governing bacterial colonization of particles and group coordination of exoenzyme production using a model, we quantitatively connect microscale bacteria-particle interactions to the carbon cycle and provide new insights for future observations

    Analysis of cybersecurity threats in Industry 4.0: the case of intrusion detection

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    Nowadays, industrial control systems are experiencing a new revolution with the interconnection of the operational equipment with the Internet, and the introduction of cutting-edge technologies such as Cloud Computing or Big data within the organization. These and other technologies are paving the way to the Industry 4.0. However, the advent of these technologies, and the innovative services that are enabled by them, will also bring novel threats whose impact needs to be understood. As a result, this paper provides an analysis of the evolution of these cyber-security issues and the requirements that must be satis ed by intrusion detection defense mechanisms in this context.Springer ; Universidad de MƔlaga. Campus de Excelencia Internacional Andalucƭa Tech
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