Clicks and Cliques. Exploring the Soul of the Community

In the paper we analyze 26 communities across the United States with the objective to understand what attaches people to their community and how this attachment differs among communities. How different are attached people from unattached? What attaches people to their community? How different are the communities? What are key drivers behind emotional attachment? To address these questions, graphical, supervised and unsupervised learning tools were used and information from the Census Bureau and the Knight Foundation were combined. Using the same pre-processed variables as Knight (2010) most likely will drive the results towards the same conclusions than the Knight foundation, so this paper does not use those variables

Pre- service Unab EFL teachers belief about vocabulary instruction

Tesis (Profesor de Inglés para la Enseñanza Básica y Media y al grado académico de Licenciado en Educación)Este estudio mixto, tomó lugar en la Universidad Andrés Bello ubicada en Santiago de Chile, en el cual 26 estudiantes de tercer año, los cuales cursan su primera práctica en la carrera de Pedagogía en Inglés, participaron en nuestro estudio. El propósito general de nuestro estudio, fue determinar las creencias que los profesores en práctica de la Universidad Andrés Bello tenían sobre cómo el vocabulario debería ser enseñado durante la educación primaria y secundaria en el contexto chileno. Durante el estudio, nos enfocamos en tres objetivos los cuales implican conocer las creencias que los profesores en práctica tenían sobre la instrucción de vocabulario, sus creencias de cómo debería llevarse a cabo, además de conocer cómo sus experiencias pasadas han influenciado sus creencias sobre la instrucción del vocabulario. El método utilizado para recolectar la información necesaria consistió de dos fases. La primera fase, involucró un cuestionario en el cual 26 profesores en práctica participaron, para luego pasar a la fase de entrevistas en la cual 4 de los participantes anteriores fueron seleccionados para ser entrevistados. Lo que este estudio evidencia, es el entusiasmo que los profesores en práctica de la UNAB demuestran respecto a la implementación de métodos y técnicas más atractivas para los estudiantes y, consecuentemente, ellos consideran el vocabulario como algo importante para el aprendizaje de un segundo idioma. Sin embargo, hay cierta confusión e inconsistencia en algunos conceptos y en la forma de cómo debería llevarse a cabo concretamente la instrucción de vocabulario. Sin embargo, pareciera que lo único que hace falta para formar profesores competentes y eficientes en la instrucción de vocabulario es guiar mejor a los profesores en práctica en este aspectoThis mixed-method study took place at Universidad Andres Bello (UNAB), located in Santiago, Chile, in which 26 third year pre-service }teachers enrolled in the English Teaching Program of the university participated in our study. The objective of the present study was to determine the beliefs that EFL pre-service teachers at UNAB held about how vocabulary should be taught in schools in the Chilean context. The study had three main aims which were to firstly determine what participants believed and knew about vocabulary instruction, to determine which methods and strategies they believed more effective to teach vocabulary, and finally to determine how previous experiences have influenced their beliefs about vocabulary instruction. The approach taken to collect the necessary information consisted of two phases. The first phase involved a questionnaire where 26 pre-service teachers participated and then an interview phase where 4 pre-service teachers were interviewed. What the study evidenced is that pre-service teachers from UNAB are very enthusiastic about implementing more appealing methods and strategies for students, and consequently, they consider vocabulary quite important when learning a second language. However, some confusion and inconsistency is shown upon some concepts and the way vocabulary should concretely be carried taught. Nevertheless, only slight guidance may be necessary to form proficient and prepared English teachers

Using Tuangou to reduce IP transit costs

A majority of ISPs (Internet Service Providers) support connectivity to the entire Internet by transiting their traffic via other providers. Although the transit prices per Mbps decline steadily, the overall transit costs of these ISPs remain high or even increase, due to the traffic growth. The discontent of the ISPs with the high transit costs has yielded notable innovations such as peering, content distribution networks, multicast, and peer-to-peer localization. While the above solutions tackle the problem by reducing the transit traffic, this paper explores a novel approach that reduces the transit costs without altering the traffic. In the proposed CIPT (Cooperative IP Transit), multiple ISPs cooperate to jointly purchase IP (Internet Protocol) transit in bulk. The aggregate transit costs decrease due to the economies-of-scale effect of typical subadditive pricing as well as burstable billing: not all ISPs transit their peak traffic during the same period. To distribute the aggregate savings among the CIPT partners, we propose Shapley-value sharing of the CIPT transit costs. Using public data about IP traffic of 264 ISPs and transit prices, we quantitatively evaluate CIPT and show that significant savings can be achieved, both in relative and absolute terms. We also discuss the organizational embodiment, relationship with transit providers, traffic confidentiality, and other aspects of CIPT

Spent Oyster Mushroom Substrate in a Mix with Organic Soil for Plant Pot Cultivation

Disposal of spent mushroom substrates can pose a problem to the environment. The reuse in crop production by its recycling as an ingredient of growing mixes would provide an environmentally safe disposition. We show the use of Pleurotus Pleurotus sp. spent substrate, sp. spent substrate, obtained after cultivation on a sunfl ower seed hulls based substrate and mixed with organic soil from local nurseries. Salvia offi cinalis Salvia offi cinalis was used to study plant growth in was used to study plant growth in pot cultivation under greenhouse conditions. Treatments were: C, control (soil used in a local nursery); T1, soil : Pleurotus Pleurotus spent substrate (2:1 v/v); and T2, equivalent to T1, but spent substrate (2:1 v/v); and T2, equivalent to T1, but using washed Pleurotus Pleurotus spent substrate in order to reduce its salt content. T1 substrate spent substrate in order to reduce its salt content. T1 substrate had 3.3 times higher electrical conductivity (7 mS cm-1) than that of the control, which is high for the growth of most plants. Air porosity was greater in T1 (7.4%) and T2 (10.2%) than the control (2.8%). The content of certain nutrients also increased with regard to the control, such as phosphorus and sulphur (T1 and T2 substrates), as well as potassium (T1 substrate). After growing 29 days on T1 substrate, plants showed a marked increase in biomass (ca. 21%, p < 0.05) and some minerals compared to the control. T2 plants grew poorly, possibly because of nitrogen defi cit. T1 substrate was adequate to sustain the growth of S. offi cinalis S. offi cinalis plants in pots, by improving air porosity and mineral content.Fil: López Castro, Ramón Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Delmastro, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Curvetto, Nestor Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; Argentin

Open cluster Dolidze 25: Stellar parameters and the metallicity in the Galactic Anticentre

The young open cluster Dolidze 25, in the direction of the Galactic Anticentre, has been attributed a very low metallicity, with typical abundances between $-0.5$ and $-0.7$ dex below solar. We intend to derive accurate cluster parameters and accurate stellar abundances for some of its members. We have obtained a large sample of intermediate- and high-resolution spectra for stars in and around Dolidze 25. We used the FASTWIND code to generate stellar atmosphere models to fit the observed spectra. We derive stellar parameters for a large number of OB stars in the area, and abundances of oxygen and silicon for a number of stars with spectral types around B0. We measure low abundances in stars of Dolidze 25. For the three stars with spectral types around B0, we find $0.3$ dex (Si) and $0.5$ dex (O) below the values typical in the solar neighbourhood. These values, even though not as low as those given previously, confirm Dolidze 25 and the surrounding H II region Sh2-284 as the most metal-poor star-forming environment known in the Milky Way. We derive a distance $4.5\pm0.3\:$kpc to the cluster ($r_{\textrm{G}}\approx12.3\:$kpc). The cluster cannot be older than $\sim3\:$Myr, and likely is not much younger. One star in its immediate vicinity, sharing the same distance, has Si and O abundances at most $0.15\:$dex below solar. The low abundances measured in Dolidze 25 are compatible with currently accepted values for the slope of the Galactic metallicity gradient, if we take into account that variations of at least $\pm0.15\:$dex are observed at a given radius. The area traditionally identified as Dolidze 25 is only a small part of a much larger star-forming region that comprises the whole dust shell associated with Sh2-284 and very likely several other smaller H II regions in its vicinity.Comment: Accepted for publication in Astronomy \& Astrophysics. 16 pages, 12 figure

Optimality-based bound contraction with multiparametric disaggregation for the global optimization of mixed-integer bilinear problems

We address nonconvex mixed-integer bilinear problems where the main challenge is the computation of a tight upper bound for the objective function to be maximized. This can be obtained by using the recently developed concept of multiparametric disaggregation following the solution of a mixed-integer linear relaxation of the bilinear problem. Besides showing that it can provide tighter bounds than a commercial global optimization solver within a given computational time, we propose to also take advantage of the relaxed formulation for contracting the variables domain and further reduce the optimality gap. Through the solution of a real-life case study from a hydroelectric power system, we show that this can be an efficient approach depending on the problem size. The relaxed formulation from multiparametric formulation is provided for a generic numeric representation system featuring a base between 2 (binary) and 10 (decimal)

It’s not the economy, stupid. ¿Qué tanto explica el voto económico los resultados en elecciones presidenciales en Chile, 1999-2013?

En la elección presidencial de 2005 en Chile, la aprobación del presidente era alta, los índices económicos eran buenos y la candidata de la coalición oficialista ganó la elección. En 1999, pese a la baja aprobación presidencial y crecimiento negativo, el candidato oficialista también ganó. Aquí estudiamos el efecto del contexto económico y la aprobación presidencial en el desempeño electoral de los candidatos oficialistas en elecciones presidenciales en Chile entre 1999 y 2013. ¿Bajo qué condiciones de aprobación del presidente saliente y situación económica del país el voto económico importa más? Utilizando los datos de la encuesta CEP, presentamos modelos probit que muestran que la condición socio-económica de los votantes, su identificación con partidos oficialistas y su aprobación presidencial predicen con mayor fuerza la intención de voto por el candidato oficialista que las variables tradicionalmente asociadas al voto económico