170,294 research outputs found
Automatic Workflow Monitoring in Industrial Environments
No full textRobust automatic workflow monitoring using visual sensors in industrial environments is still an unsolved problem. This is mainly due to the difficulties of recording data in work settings and the environmental conditions (large occlusions, similar background/foreground) which do not allow object detection/tracking algorithms to perform robustly. Hence approaches analysing trajectories are limited in such environments. However, workflow monitoring is especially needed due to quality and safety requirements. In this paper we propose a robust approach for workflow classification in industrial environments. The proposed approach consists of a robust scene descriptor and an efficient time series analysis method. Experimental results on a challenging car manufacturing dataset showed that the proposed scene descriptor is able to detect both human and machinery related motion robustly and the used time series analysis method can classify tasks in a given workflow automatically
Going beyond the expert-performance framework in the domain of chess
No full textEricsson (2014, this issue) further sharpened the expert-performance framework and provided a critical review of the evidence presented in this special issue. The findings from the prototypical expertise domain of chess were interpreted by Ericsson to be consistent with his framework and he does not accept that general cognitive abilities can account for variance in expert performance. In this response, I argue (a) that Ericsson drew a biased picture of the research findings by using a very conservative definition of expert performance, (b) that Ericsson's main alternative explanation of the research findings in the domain of chess, i.e., selection processes in the access to training opportunities, is speculative and implausible, and (c) that central evidence from the extended expert novice paradigm has not been considered in his review. Future research on the relation and interplay between general cognitive abilities and expertise needs to go beyond theories and methods of the expert-performance framework. (C) 2014 Elsevier Inc. All rights reserved
The distal C terminus of the dihydropyridine receptor β(1a) subunit is essential for tetrad formation in skeletal muscle
No full textThe skeletal muscle dihydropyridine receptor (DHPR) β(1a) subunit is indispensable for full trafficking of DHPRs into triadic junctions (i.e., the close apposition of transverse tubules and sarcoplasmic reticulum [SR]), facilitation of DHPRα(1S) voltage sensing, and arrangement of DHPRs into tetrads as a consequence of their interaction with ryanodine receptor (RyR1) homotetramers. These three features are obligatory for skeletal muscle excitation–contraction (EC) coupling. Previously, we showed that all four vertebrate β isoforms (β(1)–β(4)) facilitate α(1S) triad targeting and, except for β(3), fully enable DHPRα(1S) voltage sensing [Dayal et al., Proc. Natl. Acad. Sci. U.S.A. 110, 7488–7493 (2013)]. Consequently, β(3) failed to restore EC coupling despite the fact that both β(3) and β(1a) restore tetrads. Thus, all β-subunits are able to restore triad targeting, but only β(1a) restores both tetrads and proper DHPR–RyR1 coupling [Dayal et al., Proc. Natl. Acad. Sci. U.S.A. 110, 7488–7493 (2013)]. To investigate the molecular region(s) of β(1a) responsible for the tetradic arrangement of DHPRs and thus DHPR–RyR1 coupling, we expressed loss- and gain-of-function chimeras between β(1a) and β(4), with systematically swapped domains in zebrafish strain relaxed (β(1)-null) for patch clamp, cytoplasmic Ca(2+) transients, motility, and freeze-fracture electron microscopy. β(1a)/β(4) chimeras with either N terminus, SH3, HOOK, or GK domain derived from β(4) showed complete restoration of SR Ca(2+) release. However, chimera β(1a)/β(4)(C) with β(4) C terminus produced significantly reduced cytoplasmic Ca(2+) transients. Conversely, gain-of-function chimera β(4)/β(1a)(C) with β(1a) C terminus completely restored cytoplasmic Ca(2+) transients, DHPR tetrads, and motility. Furthermore, we found that the nonconserved, distal C terminus of β(1a) plays a pivotal role in reconstitution of DHPR tetrads and thus allosteric DHPR–RyR1 interaction, essential for skeletal muscle EC coupling
Is there "neural efficiency" during the processing of visuo-spatial information in male humans? An EEG study
No full textMore intelligent persons (high IQ) typically present a higher cortical activity during tasks requiring the encoding of visuo-spatial information, namely higher alpha (about 10 Hz) event-related desynchronization (ERD; Doppelmayr et al., 2005 [23]). The opposite is true ("neural efficiency") during the retrieval of the encoded information, as revealed by both lower alpha ERD and/or lower theta (about 5 Hz) event-related synchronization (ERS; Grabner et al., 2004 [19]). To reconcile these contrasting results, here we evaluated the working hypothesis that more intelligent male subjects are characterized by a high cortical activity during the encoding phase. This deep encoding would explain the relatively low cortical activity for the retrieval of the encoded information. To test this hypothesis, electroencephalographic (EEG) data were recorded in 22 healthy young male volunteers during visuo-spatial information processing (encoding) and short-term retrieval of the encoded information. Cortical activity was indexed by theta ERS and alpha ERD. It was found that the higher the subjects' total IQ, the stronger the frontal theta ERS during the encoding task. Furthermore, the higher the subjects' total IQ, the lower the frontal high-frequency alpha ERD (about 10-12 Hz) during the retrieval task. This was not true for parietal counterpart of these EEG rhythms. These results reconcile previous contrasting evidence confirming that more intelligent persons do not ever show event-related cortical responses compatible with "neural efficiency" hypothesis. Rather, their cortical activity would depend on flexible and task-adapting features of frontal activation. © 2009 Elsevier B.V. All rights reserved
The role of intelligence for performance in the prototypical expertise domain of chess
No full textProminent expertise researchers have repeatedly emphasized that individual differences in general cognitive abilities, in particular intelligence, do not play any role for the attained level of expertise in a given domain. This strong claim is opposed with the current body of evidence on the relevance of intelligence for expert performance in the prototypical expertise domain of chess. Although the findings are not unequivocal, presumably due to methodological aspects, several studies employing psychometric tests of intelligence have revealed that expert chess players display significantly higher intelligence than controls and that their playing strength is related to their intelligence level. In addition, by using the extended expert-novice paradigm (comparing experts with novices of different intelligence levels) it has been found that both, expertise and intelligence impact on the performance in expertise-related tasks. These studies suggest that expert chess play does not stand in isolation from intelligence and could stimulate interdisciplinary research on the role of general cognitive abilities in expertise development. (C) 2013 Elsevier Inc. All rights reserved
The mammalian rod synaptic ribbon is essential for Cav channel facilitation and ultrafast fusion of the readily releasable pool of vesicles
No full textRod photoreceptors (PRs) use ribbon synapses to transmit visual information. To signal ‘no light detected’ they release glutamate continually to activate post-synaptic receptors, and when light is detected glutamate release pauses. How a rod’s individual ribbon enables this process was studied here by recording evoked changes in whole-cell membrane capacitance from wild type and ribbonless (RIBEYE-ko) rods. Wild type rods created a readily releasable pool (RRP) of 92 synaptic vesicles (SVs) that emptied as a single kinetic phase with a τ < 0.4 msec. Lowering intracellular Ca2+-buffering accelerated Cav channel opening and facilitated release kinetics, but RRP size was unaltered. In contrast, ribbonless rods created an RRP of 24 SVs, and lacked Cav channel facilitation; however, Ca2+ channel-release coupling remained tight. The release deficits caused a sharp attenuation of rod-driven light responses measured from RIBEYE-ko mice. We conclude that the synaptic ribbon facilitates Ca2+-influx and establishes a large RRP of SVs
Individual synaptic vesicles mediate stimulated exocytosis from cochlear inner hair cells
No full textSpontaneous excitatory postsynaptic currents (sEPSCs) measured from the first synapse in the mammalian auditory pathway reach a large mean amplitude with a high level of variance (CV between 0.3 and 1). This has led some to propose that each inner hair cell (IHC) ribbon-type active zone (AZ), on average, releases ∼6 synaptic vesicles (SVs) per sEPSC in a coordinated manner. If true, then the predicted change in membrane capacitance (Cm) for such multivesicular fusion events would equate to ∼300 attofarads (aF). Here, we performed cell-attached Cm measurements to directly examine the size of fusion events at the basolateral membrane of IHCs where the AZs are located. The frequency of events depended on the membrane potential and the expression of Cav1.3, the principal Ca2+-channel type of IHCs. Fusion events averaged 40 aF, which equates to a normal-sized SV with an estimated diameter of 37 nm. The calculated SV volumes showed a high degree of variance (CV > 0.6). These results indicate that SVs fused individually with the plasma membrane during spontaneous and evoked release and SV volume may contribute more variability in EPSC amplitude than previously assumed
Is there "neural efficiency" during the processing of visuo-spatial information in male humans? An EEG study
No full textMore intelligent persons (high IQ) typically present a higher cortical activity during tasks requiring the encoding of visuo-spatial information, namely higher alpha (about 10 Hz) event-related desynchronization (ERD; Doppelmayr et al., 2005). The opposite is true ("neural efficiency") during the retrieval of the encoded information, as revealed by both lower alpha ERD and/or lower theta (about 5 Hz) event-related synchronization (ERS; Grabner et al., 2004). To reconcile these contrasting results, here we evaluated the working hypothesis that more intelligent male subjects are characterized by a high cortical activity during the encoding phase. This deep encoding would explain the relatively low cortical activity for the retrieval of the encoded information. To test this hypothesis, electroencephalographic (EEG) data were recorded in 22 healthy young male volunteers during visuo-spatial information processing (encoding) and short-term retrieval of the encoded information. Cortical activity was indexed by theta ERS and alpha ERD. It was found that the higher the subjects' total IQ, the stronger the frontal theta ERS during the encoding task. Furthermore, the higher the subjects' total IQ, the lower the frontal high-frequency alpha ERD (about 10-12 Hz) during the retrieval task. This was not true for parietal counterpart of these EEG rhythms. These results reconcile previous contrasting evidence confirming that more intelligent persons do not ever show event-related cortical responses compatible with "neural efficiency" hypothesis. Rather, their cortical activity would depend on flexible and task-adapting features of frontal activation
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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