On the existence of Stone-Cech compactification

In [G. Curi, "Exact approximations to Stone-Cech compactification'', Ann. Pure Appl. Logic, 146, 2-3, 2007, pp. 103-123] a characterization is obtained of the locales of which the Stone-Cech compactification can be defined in constructive type theory CTT, and in the formal system CZF+uREA+DC, a natural extension of Aczel's system for constructive set theory CZF by a strengthening of the Regular Extension Axiom REA and the principle of dependent choice. In this paper I show that this characterization continues to hold over the standard system CZF plus REA, thus removing in particular any dependency from a choice principle. This will follow by a result of independent interest, namely the proof that the class of continuous mappings from a compact regular locale X to a regular a set-presented locale Y is a set in CZF, even without REA. It is then shown that the existence of Stone-Cech compactification of a non-degenerate Boolean locale is independent of the axioms of CZF (+REA), so that the obtained characterization characterizes a proper subcollection of the collection of all locales. The same also holds for several, even impredicative, extensions of CZF+REA, as well as for CTT. This is in contrast with what happens in the context of Higher-order Heyting arithmetic HHA - and thus in any topos-theoretic universe: by constructions of Johnstone, Banaschewski and Mulvey, within HHA Stone-Cech compactification can be defined for every locale

On Tarski's fixed point theorem

A concept of abstract inductive definition on a complete lattice is formulated and studied. As an application, a constructive and predicative version of Tarski's fixed point theorem is obtained.Comment: Proc. Amer. Math. Soc., to appea

Is Telecommunications Productivity Characterized by Steady State Conditions? Some Empirical Evidence for 13 OECD Countries

This paper studies the convergence process, or lack thereof, of Total Factor Productivity (TFP) for a panel of 13 OECD countries over the period 1979-2007, adding breadth and depth to the convergence debate in the telecommunications industry. TFP growth is examined through the Malmquist Index and decomposed in its main determinates. Absolute and conditional convergences are estimated. Fixed-effects estimates across countries convert the cross-section test of absolute convergence into a pooled test of conditional convergence. Our findings show a growth in TFP, mainly driven by technological process. It is boosted by an increase in production possibilities and lack of bias in input utilization. Inefficiency in scale is found. Convergence tests do not suggest support in favor of absolute convergence but do exhibit evidence of conditional convergenceTotal Factor Productivity (TFP), Data Envelopment Analysis (DEA), conditional b-convergence; Fixed Effects Model.

A TV deles: Fãs brasileiros assistindo à programação norte-americana

Programas de TV norte-americanos podem ser assistidos de qualquer lugar do planeta enquanto são transmitidos ou baixados pela internet poucas horas depois. Jovens espectadores fazem isso usando diferentes ferramentas e redes sociais, discutindo o que viram. Entre esses espectadores há um grupo mais específico: os fãs. No Brasil, não é diferente. No entanto, esse mercado global não parece tão inclusivo. Alguns dos programas possuem uma série de paratextos, produtos conexos ou lógicas interativas que fãs estrangeiros não conseguem alcançar. Sentindo que estão perdendo parte da história, fãs brasileiros tentam criar novas formas de interagir com esses universos e com outros fãs. Este trabalho procura mostrar como os espectadores brasileiros interagem com produtos globais transmidiáticos e entre eles em um consumo global, com elementos locais.Programas de TV de Estados Unidos pueden ser vistos de cualquier lugar del mundo mientras son transmitidos o descargados pocas oras después. Jóvenes espectadores lo hacen utilizando distintas herramientas y redes sociales, discutiendo lo que han visto. Entre esos espectadores están los fans. En Brasil, los fans hacen lo mismo, pero un mercado que les parece global no es tan inclusivo. Algunos de los programas tienen diversos paratextos, productos conexos o lógicas interactivas que fans extranjeros no pueden alcanzar. Sintiendo que están perdiendo parte de la historia, los fans brasileños intentan crear nuevas maneras de interacción con los universos de los programas y con otros fans. Este trabajo procura mostrar como los fans interaccionan con productos globales convergentes y entre ellos en un consumo colectivo global, con elementos locales. Palabras clave: fans, televisión, convergencia mediáticaAmerican TV shows can be watched worldwide while they are being broadcast or downloaded a few hours after that. Young audiences use download tools and social networks to do it and discuss them later with other people. Inside theses audiences there is one specific group: the fans, who develop ways to interact with these products and other fans, developing specific participatory practices. Brazilian fans also download their favourite American TV Shows or watch them online, but sometimes this global market doesn't seem so inclusive. Some of these shows have a lot of paratexts, related products or interactive logics that foreign fans can't reach. Feeling that they are losing parts of the story, Brazilian fans try to create new ways to interact with those universes and with other fans. This paper aims to show how young audiences from Brazil interact with transmediatic global texts and how they interact between themselves in a global group consumption with local accents

Diversification as a Form of Risk Management in Agriculture

The objective of this study is to show the importance of diversification in the risk management process. The study areas are: Mato Grosso, with large properties, and Rio Grande do Sul with small. The developed activities are annual cultures and cattle for slaughter. The hypotheses of the work are: a) rural producers diversify their activities using modern techniques. b) Diversification has been efficient in the producers' risks reduction. c) Producers tend be as effective as possible, though they differ in the rates of risk aversion. The MOTAD and E-V models were used.Farm Management,

Burocki, Alex. De compañeros de barco a compañeros de armas. Identidades negras en el Río de la Plata, 1760-1860. Buenos Aires: Prometeo Libros. 2017. 320 páginas. ISBN 9875748323.

Fil: Curi Aznar, Claudia Gabriela. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras. Instituto de Historia Americana y Argentin

Sarmiento and women : horizons of love and education

El papel de la mujer en la vida de Domingo Faustino fue trascendental desde su nacimiento. La educación formal e informal y la activa participación de ellas tanto en el ámbito escolar como social, constituían el motor de cambio y progreso para el sanjuanino. Las fuertes influencias de su madre y de sus dos hermanas mayores, Paula y Vicenta fueron decisivas. Así, a los quince años, fundó su primera escuela en San Francisco del Monte de Oro, San Luis. La inserción en la educación de Vicenta fue impulsada por su hermano y por su vocación docente, la que ella desarrolló en el Colegio Santa Rosa a instancias de Domingo, su fundador.Woman’s role in the life of Domingo Faustino was transcendental from the moment of birth. In formal and informal education and in their active participation both at school and socially, women were his motivation for change and progress. The strong influences of his mother and two older sisters, Paula and Vicenta, were decisive factors. Thus at the age of fifteen, he founded his first school in San Francisco del Monte de Oro, province of San Luis. Vicenta’s education was due to her brother’s impulse and her own teaching vocation which she developed at Santa Rosa School founded by her brother.Fil: Curi Azar, Claudia Gabriela . Universidad Nacional de Cuy

Análise das variações na receita líquida otimizada de uma área irrigada sujeita a manejo convencional e ecológico.

O processo de obtenção de novas metodologias agrícolas, com o intuito de acelerar a produção de alimento para atender o crescimento populacional, segue no sentido, dentre outros, da maximização da produtividade, do lucro e da conservação do meio ambiente. Daí a importância das pesquisas em mecanismos que resultem em um equilíbrio sustentável entre aspectos financeiros, sociais e ambientais. Dentro deste contexto os modelos de otimização podem vir a proporcionar uma melhor solução para os processos que ocorrem neste setor produtivo. O objetivo do trabalho foi a comparação através de simulações de cenários com diferentes funções objetivo entre a agricultura convencional e a ecológica, de uma área irrigada no município de Boqueirão, PB, tendo como base de comparação benefícios econômicos (receita líquida), sociais (geração de mão-de-obra) e ambientais (uso de produtos químicos). As comparações foram efetuadas usando-se a ferramenta matemática e computacional CISDERGO. Os resultados mostraram que o manejo ecológico gera uma maior rentabilidade que o convencional