Registros de arañas epigeas en Bahía Blanca, en la región templada de Argentina

Ecological surveys of diversity and seasonal patterns of spiders in relation with cadavers have rarely been conducted, despite the high potential species diversity and abundance of spiders. The composition, abundance, guilds and seasonality of the spiders of Bahía Blanca, in the temperate region of Argentina were analysed. The study was performed in a semi-rural area between 2010 and 2011, using pitfall traps that were checked daily during 168 ± 7 days in winter, 38 days in spring, 30 days in summer, and 71 days in autumn. A total of 972 spiders were recorded belonging to 22 families and 65 species/morphospecies. The most abundant families were: Lycosidae, Zodariidae, Thomisidae, Theridiidae and Salticidae. The guild with more specimens was represented by ground hunters followed by specialists and ambush hunters, and the guild with the greatest number of species corresponded also to the ground hunters. Considering all specimens, adults prevailed with respect to juveniles, and males were more abundant than females. The more abundant species were Leprolochus birabeni, Steatoda sp. 1, Thomisidae sp. 33, Thomisidae sp. 32, Ostearius melanopygius and Metaltella simoni.A pesar del alto potencial de la diversidad de especies y abundancia de arañas, raramente han sido conducidos censos ecológicos de la diversidad y de los patrones estacionales de arañas en relación con cadáveres. Se analizó la composición, abundancia, gremios y estacionalidad de las arañas de Bahía Blanca, en la región templada de Argentina. El estudio se realizó en un área semi-rural entre 2010 y 2011, usando trampas de caída que se revisaron diariamente durante 168 ± 7 días en invierno, 38 días en primavera, 30 días en verano, y 71 días en otoño. Se registraron un total de 972 arañas pertenecientes a 22 familias y 65 especies/morfo-especies. Las familias más abundantes fueron: Lycosidae, Zodariidae, Thomisidae, Theridiidae y Salticidae. El gremio con más especímenes estuvo representado por las cazadoras del suelo seguidas por las especialistas y por las cazadoras por emboscada, y el gremio con el mayor número de especies corresponde también al de las cazadoras del suelo. Considerando todos los especí- menes, los adultos prevalecieron respecto a los juveniles, y los machos fueron más abundantes que las hembras. Las especies más abundantes fueron Leprolochus birabeni, Steatoda sp. 1, Thomisidae sp. 33, Thomisidae sp. 32, Ostearius melanopygius y Metaltella simoni.Fil: Zanetti, Noelia Inés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Entomología Aplicada y Forense; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentin

Labor Market Frictions into Staggered Wage Contracts

This paper proposes a generalization of the Calvo wage-setting equation, which embeds labor market frictions in the form of a Nash wage bargain. Adding labor market frictions changes significantly the dynamics of the standard wage-setting equation, such that it may have non-trivial implications for the design of optimal monetary policy, and could improve the ability of a general equilibrium model to replicate important labor market stylized facts.

A quantum-walk-inspired adiabatic algorithm for graph isomorphism

We present a 2-local quantum algorithm for graph isomorphism GI based on an adiabatic protocol. By exploiting continuous-time quantum-walks, we are able to avoid a mere diffusion over all possible configurations and to significantly reduce the dimensionality of the visited space. Within this restricted space, the graph isomorphism problem can be translated into the search of a satisfying assignment to a 2-SAT formula without resorting to perturbation gadgets or projective techniques. We present an analysis of the execution time of the algorithm on small instances of the graph isomorphism problem and discuss the issue of an implementation of the proposed adiabatic scheme on current quantum computing hardware.Comment: 10 pages, 5 figure

Radiative decay of the X(3872) as a mixed molecule-charmonium state in QCD Sum Rules

We use QCD sum rules to calculate the width of the radiative decay of the meson X(3872), assumed to be a mixture between charmonium and exotic molecular $[c\bar{q}][q\bar{c}]$ states with $J^{PC}=1^{++}$. We find that in a small range for the values of the mixing angle, $5^0\leq\theta\leq13^0$, we get the branching ratio $\Gamma(X\to J/\psi\gamma)/\Gamma(X\to J/\psi\pi^+\pi^-)=0.19\pm0.13$, which is in agreement, with the experimental value. This result is compatible with the analysis of the mass and decay width of the mode $J/\psi(n\pi)$ performed in the same approach.Comment: 7 pages, 9 figures; revised version accepted for publication in Phys. Rev.

A Broad Class of Discrete-Time Hypercomplex-Valued Hopfield Neural Networks

In this paper, we address the stability of a broad class of discrete-time hypercomplex-valued Hopfield-type neural networks. To ensure the neural networks belonging to this class always settle down at a stationary state, we introduce novel hypercomplex number systems referred to as real-part associative hypercomplex number systems. Real-part associative hypercomplex number systems generalize the well-known Cayley-Dickson algebras and real Clifford algebras and include the systems of real numbers, complex numbers, dual numbers, hyperbolic numbers, quaternions, tessarines, and octonions as particular instances. Apart from the novel hypercomplex number systems, we introduce a family of hypercomplex-valued activation functions called $\mathcal{B}$-projection functions. Broadly speaking, a $\mathcal{B}$-projection function projects the activation potential onto the set of all possible states of a hypercomplex-valued neuron. Using the theory presented in this paper, we confirm the stability analysis of several discrete-time hypercomplex-valued Hopfield-type neural networks from the literature. Moreover, we introduce and provide the stability analysis of a general class of Hopfield-type neural networks on Cayley-Dickson algebras

A walk through the web’s video clips

Approximately 10^5 video clips are posted every day on the Web. The popularity of Web-based video databases poses a number of challenges to machine vision scientists: how do we organize, index and search such large wealth of data? Content-based video search and classification have been proposed in the literature and applied successfully to analyzing movies, TV broadcasts and lab-made videos. We explore the performance of some of these algorithms on a large data-set of approximately 3000 videos. We collected our data-set directly from the Web minimizing bias for content or quality, way so as to have a faithful representation of the statistics of this medium. We find that the algorithms that we have come to trust do not work well on video clips, because their quality is lower and their subject is more varied. We will make the data publicly available to encourage further research

Miss, I got mad today! : the anger diary, a tool to promote emotion regulation

Effective management of emotions has strong implications in the development of adaptive behaviours during childhood and adolescence. The purpose of this study was to examine the use of a new method of emotion regulation named the ‘aRRabbiadiaro’ (Anger Diary), with primary school children. The participants included 119 children attending 7 classes from three primary schools located in middle-class urban communities in the province of Pavia, Italy. In the first phase, the participants were asked to complete a narrative tool which investigated how they coped with anger in their everyday life and whether the use of narrative applied to episodes of anger and facilitated adaptive ways of coping with negative feelings. Subsequently the study assessed the relationship between effective anger management and social functioning in the peer group. Our findings suggest that the use of diary writing seems to represent a promising instrument to promote the development of emotional and socio-cognitive skills in school children.peer-reviewe