3,415 research outputs found

    Growth and social capital: an evolutionary model

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    In this paper, we analyze the role of cooperation between firms through a model of growth and social capital. In a growth model à la Solow we incorporate the set of resources that a relational network has at its disposals, as a distinct production factor, and thus examine its dissemination through evolutionary type processes in firm interactions. Dynamic analysis of the model demonstrates that cooperation is able to increase the productivity of factors, fostering a higher rate of growth in the long term. The most significant result is that scarcity of social capital can produce a general collapse of the economic system in areas in which long term growth is usually sustained by the learning by doing and spillover of knowledge phenomena. This conclusion leads to reconsider the role of local development economic policies that should concentrate on activities that promote repeated interaction between firms proven to be cooperative or that encourage the formation of technological consortia.Economic growth; Social capital; Networks; Evolutionary games

    Economic interactions and social tolerance: A dynamic perspective

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    We propose an evolutionary game to analyze the dynamics of tolerance among heterogeneous economic agents. We show that: (i) intolerance is much more persistent than tolerance; (ii) a fully tolerant society assures prosperity; (iii) cultural integration should precede economic integration

    A hierarchical Bayesian model to infer PL(Z) relations using Gaia parallaxes

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    Aims. We aim at creating a Bayesian model to infer the coefficients of PL or PLZ relations that propagates uncertainties in the observables in a rigorous and well founded way. Methods. We propose a directed acyclic graph to encode the conditional probabilities of the inference model that will allow us to infer probability distributions for the PL and PL(Z) relations. We evaluate the model with several semi-synthetic data sets and apply it to a sample of 200 fundamental mode and first overtone mode RR Lyrae stars for which Gaia DR1 parallaxes and literature Ks-band mean magnitudes are available. We define and test several hyperprior probabilities to verify their adequacy and check the sensitivity of the solution with respect to the prior choice. Results. The main conclusion of this work is the absolute necessity of incorporating the existing correlations between the observed variables (periods, metallicities and parallaxes) in the form of model priors in order to avoid systematically biased results, especially in the case of non-negligible uncertainties in the parallaxes. The tests with the semi-synthetic data based on the data set used in Gaia Collaboration et al. (2017) reveal the significant impact that the existing correlations between parallax, metallicity and periods have on the inferred parameters. The relation coefficients obtained here have been superseded by those presented in Muraveva et al. (2018a), that incorporates the findings of this work and the more recent Gaia DR2 measurements.Comment: 14 pages, 12 figures. Submitted to A&

    Employment, innovation, and interfirm networks

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    This paper studies the employment impact of business network agreements, an innovative policy instrument introduced in Italy in 2010 to stimulate interfirm cooperation, with the aim of increasing innovative capacity and market competitiveness. We estimate the impact of these networks on employment for a panel of Italian firms using a system generalized method of moments and considering the literature on the employment impact of innovation. We find that networks, which can be interpreted as a form of open innovation, have a positive impact on employment; moreover, this impact appears positively influenced by sectoral and regional heterogeneity of firms and the region\u2019s innovation capacities. Overall, the results suggest that participation in networks where firms share industrial, commercial, and technical knowledge improves firm performance, creating synergies that help firms, especially small and medium-sized enterprises, to manage the growing complexity of knowledge and the fierce competition arising from increasingly globalized markets

    Handle-hand compatibility effects for the right and left hand using reach-to-touch movements

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    In stimulus-response compatibility tasks, performance is better when the handle of an object is oriented on the same side of the response than when the handle is oriented on the opposite side. Two major alternative accounts, the motor affordance and spatial accounts, have been proposed to explain this handle-hand compatibility effect. In two experiments, we tested between these two accounts by administering a go/no-go task to right-handed participants. Handled objects presented on a touchscreen were used as stimuli. Half of the participants had to reach-to-touch the stimuli by using their dominant hand, the other half by using their nondominant hand. Liftoff times (LTs), movement times (MTs) and spatial coordinates of the movement endpoints were recorded. Results from the LTs and MTs analyses showed no evidence of handle-hand compatibility effects. In contrast, the analyses of the spatial coordinates revealed that participants' touches were shifted more laterally towards the handle when the handles were oriented on the same side of the responding hand (Experiments 1 and 2). Furthermore, the right-hand touches landed higher (towards the handle) than the left-hand touches, especially when the vertical object dimension was particularly salient (Experiment 1). Overall, these results are in line with the activation of hand motor programs to reach and grasp the object as predicted by the motor account, at least for the right/dominant hand

    Evidence for the Concreteness of Abstract Language: A Meta-Analysis of Neuroimaging Studies

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    The neural mechanisms subserving the processing of abstract concepts remain largely debated. Even within the embodiment theoretical framework, most authors suggest that abstract concepts are coded in a linguistic propositional format, although they do not completely deny the role of sensorimotor and emotional experiences in coding it. To our knowledge, only one recent proposal puts forward that the processing of concrete and abstract concepts relies on the same mechanisms, with the only difference being in the complexity of the underlying experiences. In this paper, we performed a meta-analysis using the Activation Likelihood Estimates (ALE) method on 33 functional neuroimaging studies that considered activations related to abstract and concrete concepts. The results suggest that (1) concrete and abstract concepts share the recruitment of the temporo-fronto-parietal circuits normally involved in the interactions with the physical world, (2) processing concrete concepts recruits fronto-parietal areas better than abstract concepts, and (3) abstract concepts recruit Broca’s region more strongly than concrete ones. Based on anatomical and physiological evidence, Broca’s region is not only a linguistic region mainly devoted to speech production, but it is endowed with complex motor representations of different biological effectors. Hence, we propose that the stronger recruitment of this region for abstract concepts is expression of the complex sensorimotor experiences underlying it, rather than evidence of a purely linguistic format of its processing

    Single and Multiple Clinical Syndromes in Incarcerated Offenders

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    The present study examined the prevalence and correlates of clinical syndromes in a large group (N = 438) of incarcerated violent offenders, looking at differences between inmates with one and those with more than one clinical syndromes. More than a half of the sample (57%) reported clinically relevant symptoms for at least one clinical syndrome (n = 252), and the majority of them (38%) reported more syndromes in comorbidity (n = 169). Increased severity of clinical conditions (none, one, more than one syndrome) corresponded with significantly greater levels of personality disorder traits, psychological symptoms, dissociation, and negative emotionality, with large effect sizes. After controlling for co-occurrence of personality disorder traits and other symptoms, the presence of more than one comorbid syndrome significantly predicted unique variance in dissociation (positively) and positive emotionality (negatively). The presence of one clinical syndrome significantly and positively predicted negative emotionality. Findings support the possibility that the complexity, and not just the presence, of psychopathology could identify different groups of inmates

    Quantitative uniqueness for elliptic equations with singular lower order terms

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    We use a Carleman type inequality of Koch and Tataru to obtain quantitative estimates of unique continuation for solutions of second order elliptic equations with singular lower order terms. First we prove a three sphere inequality and then describe two methods of propagation of smallness from sets of positive measure.Comment: 23 pages, v2 small changes are done and some mistakes are correcte

    The increasing temperature as driving force for spatial distribution patterns of Parapenaeus longirostris (Lucas 1846) in the Strait of Sicily (Central Mediterranean Sea)

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    The deep-water rose shrimp Parapenaeus longirostris (DPS), a demersal decapod representing the most important component of crustacean landings in the Mediterranean Sea, has been suggested as a species that may exhibit temperature-driven changes in the spatio-temporal dynamics. Considering that Mediterranean waters are warming up faster than oceans, understanding the relationships of DPS populations with temperature variations and the related changes in spatial patterns is absolutely key for its management. Using a long-term dataset covering 13-years from scientific surveys (International Bottom Trawl-Surveys in the Mediterranean, MEDITS; Italian national trawl surveys, GRUND) in the Strait of Sicily (central Mediterranean Sea), the annual DPS spatial patches and the depth distribution were investigated using geostatistical and quotient analyses. The patches dimension and depth range occupation were then related to sea temperature by using linear regression analysis. Results showed that both the dimension of DPS spatial patches and the depth distribution range occupied increased concurrently with temperature. Our findings corroborate that the ongoing sea warming widen areas suitable for this species and in which it can expand its spatial distribution

    The space of words: on the sensorimotor processing of variable affordances in noun-adjective combinations.

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    Evidence suggests that the processing of graspable object nouns elicits specific motor programs related to potential hand-object interactions. Notably, adjectives specifying manipulative features of these objects are integrated into this sensorimotor representation. The present experiment investigated the effect of adjectives denoting the position of the object in space on the sensorimotor representation of graspable object nouns. We used a reach-to-grasp compatibility task, in which participants had to categorize object nouns as artifact or natural, by performing either a power or precision grip matching or not the typical grip associated with the object. On each trial, the object noun was presented with a near or far adjective. While reliable grasp-compatibility effects emerged for object nouns on RTs, this was not modulated by the spatial position denoted by the adjective. Spatial adjectives appear not to be integrated into the noun sensorimotor representation, supporting the distinction between stable and variable affordances
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