1,356 research outputs found

    A visual conflict hypothesis for global-local visual deficits in Williams Syndrome: simulations and data

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    Individuals with Williams Syndrome demonstrate impairments in visuospatial cognition. This has been ascribed to a local processing bias. More specifically, it has been proposed that the deficit arises from a problem in disengaging attention from local features. We present preliminary data from an integrated empirical and computational exploration of this phenomenon. Using a connectionist model, we first clarify and formalize the proposal that visuospatial deficits arise from an inability to locally disengage. We then introduce two empirical studies using Navon-style stimuli. The first explored sensitivity to local vs. global features in a perception task, evaluating the effect of a manipulation that raised the salience of global organization. Thirteen children with WS exhibited the same sensitivity to this manipulation as CA-matched controls, suggesting no local bias in perception. The second study focused on image reproduction and demonstrated that in contrast to controls, the children with WS were distracted in their drawings by having the target in front of them rather than drawing from memory. We discuss the results in terms of an inability to disengage during the planning stage of reproduction due to over-focusing on local elements of the current visual stimulus

    Micro-evidence on the determinants of innovation in the Netherlands: The relative importance of absorptive capacity and agglomeration externalities

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    This paper employs firm-level data to analyze the relative importance of firm characteristics and agglomeration externalities in explaining variation in innovation rates across firms. More specifically, we combine micro-data and census data to estimate the probability that a firm will introduce a goods, service or process innovation. We consider internal firm-level characteristics as well as externalities, using information on the regional production structure to test for Marshall-Arrow-Romer, Porter and Jacobs effects. Our results show that most firm-specific variables are highly statistically significant, whereas agglomeration variables are only significant for a few specific sectors, and even then only for some types of innovation

    Spatial Patterns of Technology Diffusion: An Empirical Analysis Using TFP

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    In this paper we employ techniques developed in spatial econometrics to analyse spatial patterns of technology diffusion, to detect clusters and to estimate theoretical models that incorporate space explicitly. These techniques correct for misspecifications resulting from the omission of spatial linkages in standard empirical models of economic growth. Our dataset consists of TFP estimates for 73 countries over the period 1960-2000, and we find that TFP growth rates and levels are positively autocorrelated over space, meaning that high or low values tend to be clustered. We also find that TFP levels are becoming more clustered over time, suggesting the possibility that technology levels are converging locally. Estimation of spatial versions of the Nelson and Phelps (1966) model shows that the impact of being located close to a country with high TFP growth rates is positive and substantial

    The use of ultrasonic echo pulse velocity as an NDT method to predict the concrete strength and uniformity

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    The ultrasonic approach is one of the non-destructive testing methods that most technologically progressed in past few years. This study aims to validate the accuracy and capabilities of this method in the mechanical characterization of concrete elements, by using an ultrasonic tomography equipment based in echo pulse velocity (S-waves). The elastic modulus and compressive strength of concrete are estimated from the echo pulse velocity. Furthermore, the uniformity of concrete elements is evaluated. The concrete compression strength prediction was performed on cubic specimens and the reached accuracy was over 91% using the analytical approach proposed on this study. The correlation coefficient between the pulse echo velocity and the uniaxial compression strength found in this study was over 97%. Thus, the use of the ultrasonic NDT to evaluate the uniformity of concrete elements proved to be efficient.info:eu-repo/semantics/publishedVersio

    Деякі аспекти методики аналізу сучасної музики

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    The violated in this article problem of the analysis of the modern music, complicated through the permanent growth of action of music outside factors of the modern music creation and its text transformations and anomalies, complications of communicative nature, is extraordinarily important in a scientifically-methodical plan. All these factors are in dissoluble communication, and it is therefore needed permanent and intent attention from the side of tutor, which forms the pupil's ability to correctly select strategy, tactics and tools of the analytical work

    The Safe-Port project: an approach to port surveillance and protection

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    SAFE-PORT is a recently started project addressing the complex issue of determining the best configurations of resources for harbour and port surveillance and protection. More specifically, the main goal is to find, for any given scenario, an adequate set of configuration solutions — i.e., number and type of sensors and equipments, their locations and operating modes, the corresponding personnel and other support resources — that maximize protection over a specific area. The project includes research and development of sensors models, novel algorithms for optimization and decision support, and a computer-based decision support system (DSS) to assist decision makers in that task. It includes also the development of a simulation environment for modelling relevant aspects of the scenario (including sensors used for surveillance, platforms, threats and the environment), capable to incorporate data from field-trials, used to test and validate solutions proposed by the DSS. Test cases will consider the use of intelligent agents to model the behaviour of threats and of NATO forces in a realistic way, following experts’ definitions and parameters

    Third-generation leptoquark decays and collider searches

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    Collider searches for first-, second-, and third-generation scalar (S) or vector (V) leptoquarks (LQs) focus on the quark-lepton decay modes S,V -> q l. For SU(2)-doublet and -triplet leptoquarks with a sufficiently large splitting between the components, decays involving real W-boson emission (such as S_2^{(+5/3)} -> S_2^{(+2/3)} W^{+} and others) become possible and can change the patterns of leptoquark decays. For third-generation leptoquarks, where these mass splittings might be large, such modes could dominate certain leptoquark decays as they are (if kinematically allowed) guaranteed to be of order g^2 where g is the electroweak coupling. We calculate the decay rates for all such processes involving SU(2)-doublet and triplet, scalar and vector leptoquarks. Standard limits on mass splittings from precision electroweak measurements imply that only such decays involving SU(2)-doublet scalar LQs are likely kinematically possible.Comment: 13 pages, LaTeX, 2 separate postscript figure

    Aggregation of Cyclodextrins: Fundamental Issues and Applications

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    The aggregation of cyclodextrins (CD) in aqueous solution is an old, yet still vastly unexplored topic that has been studied at least since the 1980s. At that time, few authors took into consideration the possibility of formation of aggregates for the interpretation of thermodynamic and thermophysical properties of CDs in aqueous solution. The aggregates appear at quite low CD concentrations and seem to encompass only a small number of CD molecules. They also occur in water in the presence of hydrophobic or amphiphilic moieties, including surfactants, assuming a preassembled state with the hydrophobic chains threading through one or two CDs. After a long period in which it has been neglected, CD aggregation is now a hot topic and one far from gathering consensus. In this chapter, a timely and critical review on the phenomenon of CD aggregation and the respective supramolecular properties, including some computational rationales, will be presented. A comprehensive summary of CD aggregates studied to date, indicating the formation conditions, characterization techniques, and applications, is also provided

    Nuclear dependence coefficient α(A,qT)\alpha(A,q_T) for the Drell-Yan and J/ψ\psi production

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    Define the nuclear dependence coefficient α(A,qT)\alpha(A,q_T) in terms of ratio of transverse momentum spectrum in hadron-nucleus and in hadron-nucleon collisions: dσhAdqT2/dσhNdqT2Aα(A,qT)\frac{d\sigma^{hA}}{dq_T^2}/ \frac{d\sigma^{hN}}{dq_T^2}\equiv A^{\alpha(A,q_T)}. We argue that in small qTq_T region, the α(A,qT)\alpha(A,q_T) for the Drell-Yan and J/ψ\psi production is given by a universal function:\ a+bqT2a+b q_T^2, where parameters a and b are completely determined by either calculable quantities or independently measurable physical observables. We demonstrate that this universal function α(A,qT)\alpha(A,q_T) is insensitive to the A for normal nuclear targets. For a color deconfined nuclear medium, the α(A,qT)\alpha(A,q_T) becomes strongly dependent on the A. We also show that our α(A,qT)\alpha(A,q_T) for the Drell-Yan process is naturally linked to perturbatively calculated α(A,qT)\alpha(A,q_T) at large qTq_T without any free parameters, and the α(A,qT)\alpha(A,q_T) is consistent with E772 data for all qTq_T.Comment: latex, 28 pages, 10 figures, updated two figures, and add more discussion

    Genetic susceptibility in the development of colorectal adenomas according to family history of colorectal cancer

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    Our study aimed to evaluate the relevance of genetic susceptibility in the development of colorectal adenomas (CRA) and its relationship with the presence of family history of colorectal cancer (CRC). Genomic DNA from 750 cases (first degree relatives of patients with CRC) and 750 controls (subjects with no family history of CRC) was genotyped for 99 single nucleotide polymorphisms (SNPs) previously associated with CRC/CRA risk by GWAS and candidate gene studies by using the MassArray™ (Sequenom) platform. Cases and controls were matched by gender, age and histological lesion. Eight hundred and fifty-eight patients showed no neoplastic lesions, whereas 288 patients showed low-risk adenomas, and 354 patients presented high-risk adenomas. Two SNPs (rs10505477, rs6983267) in the CASC8 gene were associated with a reduced risk of CRA in controls (log-additive models, OR: 0.67, 95%CI:0.54–0.83, and OR:0.66, 95%CI:0.54–0.84, respectively). Stratified analysis by histological lesion revealed the association of rs10505477 and rs6983267 variants with reduced risk of low- and high-risk adenomas in controls, being this effect stronger in low-risk adenomas (log-additive models, OR:0.63, 95%CI:0.47–0.84 and OR:0.64, 95%CI:0.47–0.86, respectively). Moreover, 2 SNPs (rs10795668, rs11255841) in the noncoding LINC00709 gene were significantly associated with a reduced risk of low-risk adenomas in cases (recessive models, OR:0.22, 95%CI:0.06–0.72, and OR:0.08, 95%CI:0.03–0.61) and controls (dominant models, OR:0.50, 95%CI:0.34–0.75, and OR:0.52, 95%CI:0.35–0.78, respectively). In conclusion, some variants associated with CRC risk (rs10505477, rs6983267, rs10795668 and rs11255841) are also involved in the susceptibility to CRA and specific subtypes. These associations are influenced by the presence of family history of CRC
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