Stochastic mean field formulation of the dynamics of diluted neural networks

We consider pulse-coupled Leaky Integrate-and-Fire neural networks with randomly distributed synaptic couplings. This random dilution induces fluctuations in the evolution of the macroscopic variables and deterministic chaos at the microscopic level. Our main aim is to mimic the effect of the dilution as a noise source acting on the dynamics of a globally coupled non-chaotic system. Indeed, the evolution of a diluted neural network can be well approximated as a fully pulse coupled network, where each neuron is driven by a mean synaptic current plus additive noise. These terms represent the average and the fluctuations of the synaptic currents acting on the single neurons in the diluted system. The main microscopic and macroscopic dynamical features can be retrieved with this stochastic approximation. Furthermore, the microscopic stability of the diluted network can be also reproduced, as demonstrated from the almost coincidence of the measured Lyapunov exponents in the deterministic and stochastic cases for an ample range of system sizes. Our results strongly suggest that the fluctuations in the synaptic currents are responsible for the emergence of chaos in this class of pulse coupled networks.Comment: 12 Pages, 4 Figure

Using GitHub as a Teaching Tool for Programming Courses

GitHub has become the most popular code management platform in the software development industry. It allows developers to manage their software development projects and collaborate with each other. Recently, educators also started using GitHub as a teaching tool for programming courses by hosting code samples and managing student assignments. In this study, we examine how GitHub is being used in academia, and we discuss the motivations and the benefits of using this platform. We also present authors’ experience of using GitHub in programming courses of a software engineering program. We discuss the benefits and challenges of using GitHub and GitHub classroom in the classroom.Cockrell School of Engineerin

The distribution of the economic activity in the Mediterranean axis. Identification of cluster by sectors of economic activity.

Agglomeration economies play an important role in the explanation of the development and regional growth. For this reason, there exists a growing interest in the analysis of standards of co-localisation of the economic activities. This topic has been dealt with from different approaches using a good number of technical statistics. Our proposal is to present some of the more well-known statistics usually used in epidemiology, with the objective of identifying spatial clusters of companies dedicated to the same economic activity. As such, this paper analyses the geographic distribution of economic activity throughout the Mediterranean to the smallest possible level of spatial integration (post code level). Firstly, by using exploratory analysis tools of spatial data we identify patterns of localisation of economic activity including both industrial and service areas. Secondly, by using the statistics of T. Tango (1995) and M. Kulldorff (1997) we identify clusters of businesses in distinct subsectors of activity. The information is obtained from the 'Sistema Anual de Balances Ibéricos' (SABI) database and using the National Classification of Economic Activities NCEA code to a 2 digit level. Our results highlight that great differences exist in the production geographic concentration in all sectors. Additionally, the results from our analysis also reveal that well defined groups exist within the economic sectors.

Ana Enriqueta Terán: poetisa de la lengua

Este año ha sido esencial en la vida de la escritora Ana Enriqueta Terán, tres libros estupendos suyos han sido publicados en los primeros seis meses. Uno de sonetos con dibujos de ella misma (Otros sonetos de todos mis tiempos. Casa Nacional de las Letras Andrés Bello, Caracas), una novela (Apuntes y congojas de una decadencia narrada en tres muertes. Fundación Editorial El Perro y la Rana, Caracas), y a finales del mes de junio - en el marco del XI Festival Mundial de Poesía de Venezuela -, la prestigiosa Biblioteca Ayacucho ha presentado con el Nº 252 de su Colección Clásica a Piedra de habla, antología poética con prólogo de Patricia Guzmán titulado Ana Enriqueta Terán Voz relampagueante de misterio y belleza, amén de la profusa cronología y concienzuda compilación de las fuentes bibliográficas. También este año, el Museo de Arte Valencia conjuntamente con la Red de Escritores de Venezuela y de un grupo de amigos de la poetisa constituidos como comité preparatorio para la celebración del centenario de la escritora, le rindió un cálido homenaje el domingo 4 de mayo, aniversario noventa y seis (96) de su nacimiento en Valera, estado Trujillo, de la ahora República Bolivariana de Venezuel

William Barton Rogers and the Idea of MIT

Winner, 2009 Outstanding Book Award, History of Education SocietyWinner, 2009 Richard Slatten Prize for Excellence in Virginia Biography, Virginia Historical SocietyConceptual founder of the Massachusetts Institute of Technology, William Barton Rogers was a highly influential scientific mind and educational reformer of the nineteenth century. A. J. Angulo recounts the largely unknown story of one man's ideas and how they gave way to the creation of one of America’s premier institutions of higher learning. MIT's long tradition of teaching, research, and technological innovation for real-world applications is inexorably linked to Rogers’ educational philosophy. Emphasizing the “useful arts”—a curriculum of specialized scientific study stressing theory and practice, innovation and functionality—Rogers sought to revolutionize standard educational practices of the day. Controversial in an era typified by a generalist approach to teaching the sciences, Rogers’ model is now widely emulated by institutions throughout the world. Exploring the intersection of Rogers' educational philosophy and the rise of technical institutes in America, this biography offers a long-overdue account of the man behind MIT