499 research outputs found

    Toward cognitively constrained models of language processing:A review

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    Language processing is not an isolated capacity, but is embedded in other aspects of our cognition. However, it is still largely unexplored to what extent and how language processing interacts with general cognitive resources. This question can be investigated with cognitively constrained computational models, which simulate the cognitive processes involved in language processing. The theoretical claims implemented in cognitive models interact with general architectural constraints such as memory limitations. This way, it generates new predictions that can be tested in experiments, thus generating new data that can give rise to new theoretical insights. This theory-model-experiment cycle is a promising method for investigating aspects of language processing that are difficult to investigate with more traditional experimental techniques. This review specifically examines the language processing models of Lewis and Vasishth (2005), Reitter et al. (2011), and Van Rij et al. (2010), all implemented in the cognitive architecture Adaptive Control of Thought—Rational (Anderson et al., 2004). These models are all limited by the assumptions about cognitive capacities provided by the cognitive architecture, but use different linguistic approaches. Because of this, their comparison provides insight into the extent to which assumptions about general cognitive resources influence concretely implemented models of linguistic competence. For example, the sheer speed and accuracy of human language processing is a current challenge in the field of cognitive modeling, as it does not seem to adhere to the same memory and processing capacities that have been found in other cognitive processes. Architecture-based cognitive models of language processing may be able to make explicit which language-specific resources are needed to acquire and process natural language. The review sheds light on cognitively constrained models of language processing from two angles: we discuss (1) whether currently adopted cognitive assumptions meet the requirements for language processing, and (2) how validated cognitive architectures can constrain linguistically motivated models, which, all other things being equal, will increase the cognitive plausibility of these models. Overall, the evaluation of cognitively constrained models of language processing will allow for a better understanding of the relation between data, linguistic theory, cognitive assumptions, and explanation

    Update kosten en baten van harmonisatie van de rechtspositie van overheidspersoneel

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    Dit rapport beschrijft de kosten en baten voor de overheid als ambtenaren dezelfde rechtspositie krijgen als andere werknemers (‘harmonisatie’). Zij krijgen dan een arbeidscontract in plaats van een aanstelling; gaan voor rechtszaken naar de kantonrechter in plaats van de bestuursrechter; en krijgen een eigen CAO. Omdat er bij verschillende kosten en baten onzekerheid bestaat, wordt gewerkt met drie scenario’s. De kosten van harmonisatie zijn eenmalig en liggen tussen € 53 en 186 miljoen. Dit betreft met name opleidingen en administratieve organisatie. De baten zijn € 6,6 tot 21,9 miljoen per jaar. Deze baten bestaan uit besparingen bij de rechtspraak en besparingen door deregulering. In het middenscenario is de terugverdientijd ruim zeven jaar. In het meest ongunstige geval loopt de terugverdientijd op tot 28 jaar. Bij een goede planning en sturing van het proces - waarbij de kosten in de hand worden gehouden - en baten die gunstig uitvallen, is de investering in drie jaar terugverdiend. Dit rapport bouwt voort op een rapport van SEO en Regioplan uit 2006. De kosten zijn gedaald omdat de huidige inzichten wijzen op minder behoefte aan opleidingen. De baten zijn hoger door een betere inschatting van de opbrengsten van de overgang van bestuursrechter naar kantonrechter

    Deformed two center shell model

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    A highly specialized two-center shell model has been developed accounting for the splitting of a deformed parent nucleus into two ellipsoidaly deformed fragments. The potential is based on deformed oscillator wells in direct correspondance with the shape change of the nuclear system. For the first time a potential responsible for the necking part between the fragments is introduced on potential theory basis. As a direct consequence, spin-orbit {\bf ls} and {\bf l2^2} operators are calculated as shape dependent. Level scheme evolution along the fission path for pairs of ellipsoidaly deformed fragments is calculated. The Strutinsky method yields the shell corrections for different mass asymmetries from the superheavy nucleus 306^{306}122 and 252^{252}Cf all along the splitting process.Comment: 32 pages, 8 figure

    FROM MOUSTACHES TO MY SPACES

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    Radical removal of malignant lesions may be improved using tumor-targeted dual-modality probes that contain both a radiotracer and a fluorescent label to allow for enhanced intraoperative delineation of tumor resection margins. Because pretargeting strategies yield high signal-to-background ratios, we evaluated the feasibility of a pretargeting strategy for intraoperative imaging in prostate cancer using an anti-TROP-2 x anti-HSG bispecific antibody (TF12) in conjunction with the dual-labeled diHSG peptide (RDC018) equipped with both a DOTA chelate for radiolabeling purposes and a fluorophore (IRdye800CW) to allow near-infrared optical imaging. Nude mice implanted s.c. with TROP-2-expressing PC3 human prostate tumor cells or with PC3 metastases in the scapular and suprarenal region were injected i.v. with 1 mg of TF12 and, after 16 hours of tumor accumulation and blood clearance, were subsequently injected with 10 MBq, 0.2 nmol/mouse of either (111)In-RDC018 or (111)In-IMP288 as a control. Two hours after injection, both microSPECT/CT and fluorescence images were acquired, both before and after resection of the tumor nodules. After image acquisition, the biodistribution of (111)In-RDC018 and (111)In-IMP288 was determined and tumors were analyzed immunohistochemically. The biodistribution of the dual-label RDC018 showed specific accumulation in the TROP-2-expressing PC3 tumors (12.4 +/- 3.7% ID/g at 2 hours postinjection), comparable with (111)In-IMP288 (9.1 +/- 2.8% ID/g at 2 hours postinjection). MicroSPECT/CT and near-infrared fluorescence (NIRF) imaging confirmed this TROP-2-specific uptake of the dual-label (111)In-RDC018 in both the s.c. and metastatic growing tumor model. In addition, PC3 metastases could be visualized preoperatively with SPECT/CT and could subsequently be resected by image-guided surgery using intraoperative NIRF imaging, showing the preclinical feasibility of pretargeted dual-modality imaging approach in prostate cancer

    Extinction of ants' feeding and social foraging on myrmecochorous seeds

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    BACKGROUND/AIMS: Fibrocaps is a dry powder fibrin sealant containing human plasma-derived fibrinogen and thrombin. The safety, efficacy, and application methods for Fibrocaps were evaluated in an exploratory, first-in-human, noncomparative, clinical study. METHODS: Patients with minor bleeding/oozing after elective partial hepatic resection had Fibrocaps applied to the bleeding site either directly from the vial or from a spray device, with manual pressure applied using a cellulose, collagen, or gelatin sponge, if needed. Safety was evaluated at screening and postoperative days 1, 2, and 5, and weeks 4 and 12. The formation of anti-thrombin antibodies was assessed at baseline, and after 4 and 12 weeks. Time to hemostasis (TTH) within 10 min was determined. RESULTS: Twenty-nine patients were treated with Fibrocaps; 6 experienced serious adverse events that were not related to the course of treatment. Adverse events occurring in >10% of patients were nausea, constipation, hypotension, obstipation, hypokalemia, and postoperative pain. Most adverse events were mild or moderate in severity. No patient developed anti-thrombin antibodies. The percentage of patients who achieved hemostasis was 93%; the median TTH was 3.8 min (range 0.3-10.3). Manual pressure was applied with Fibrocaps in 19 patients and considered beneficial in most. CONCLUSION: Fibrocaps was well tolerated in patients undergoing elective hepatic resection and resulted in rapid hemostasis. These safety and efficacy results support further clinical testing of this ready-to-use fibrin sealant as an adjunct to surgical hemostasis. (c) 2015 S. Karger AG, Basel

    Arbovirus-Derived piRNAs Exhibit a Ping-Pong Signature in Mosquito Cells

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    The siRNA pathway is an essential antiviral mechanism in insects. Whether other RNA interference pathways are involved in antiviral defense remains unclear. Here, we report in cells derived from the two main vectors for arboviruses, Aedes albopictus and Aedes aegypti, the production of viral small RNAs that exhibit the hallmarks of ping-pong derived piwi-associated RNAs (piRNAs) after infection with positive or negative sense RNA viruses. Furthermore, these cells produce endogenous piRNAs that mapped to transposable elements. Our results show that these mosquito cells can initiate de novo piRNA production and recapitulate the ping-pong dependent piRNA pathway upon viral infection. The mechanism of viral-piRNA production is discussed

    The GATA-factor elt-2 is essential for formation of the Caenorhabditis elegans intestine

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    AbstractThe Caenorhabditis elegans elt-2 gene encodes a single-finger GATA factor, previously cloned by virtue of its binding to a tandem pair of GATA sites that control the gut-specific ges-1 esterase gene. In the present paper, we show that elt-2 expression is completely gut specific, beginning when the embryonic gut has only two cells (one cell cycle prior to ges-1 expression) and continuing in every cell of the gut throughout the life of the worm. When elt-2 is expressed ectopically using a transgenic heat-shock construct, the endogenous ges-1 gene is now expressed in most if not all cells of the embryo; several other gut markers (including a transgenic elt-2-promoter: lacZ reporter construct designed to test for elt-2 autoregulation) are also expressed ectopically in the same experiment. These effects are specific in that two other C. elegans GATA factors (elt-1 and elt-3) do not cause ectopic gut gene expression. An imprecise transposon excision was identified that removes the entire elt-2 coding region. Homozygous elt-2 null mutants die at the L1 larval stage with an apparent malformation or degeneration of gut cells. Although the loss of elt-2 function has major consequences for later gut morphogenesis and function, mutant embryos still express ges-1. We suggest that elt-2 is part of a redundant network of genes that controls embryonic gut development; other factors may be able to compensate for elt-2 loss in the earlier stages of gut development but not in later stages. We discuss whether elements of this regulatory network may be conserved in all metazoa
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