Costly Investment, Complementarities, International Technological-Knowledge Diffusion and the Skill Premium

We examine the behavior of the skill premium in a two-country general equilibrium growth model assuming (i) technological-knowledge diffusion; (ii) internal costly investment in both physical capital and R&D; and (iii) complementarities between intermediate goods in production. We find that these three economic features affect the steady-state growth rate in both countries. However, only in the imitator country do they influence the skill premium. We also find that the steady-state skill premium in the innovator country is affected by its relative labor productivity rather than by its relative labor endowments. This result contrasts with most skill-biased technological change models and suggests that the sustained increase in the skill premium observed in several developed countries over the last three decades may have been due to increases in the relative productive advantage of skilled labor.technological-knowledge bias, skill premium, complementarities, costly investment, technological-knowledge diffusion

Vanishing ideals over graphs and even cycles

Let X be an algebraic toric set in a projective space over a finite field. We study the vanishing ideal, I(X), of X and show some useful degree bounds for a minimal set of generators of I(X). We give an explicit description of a set of generators of I(X), when X is the algebraic toric set associated to an even cycle or to a connected bipartite graph with pairwise disjoint even cycles. In this case, a fomula for the regularity of I(X) is given. We show an upper bound for this invariant, when X is associated to a (not necessarily connected) bipartite graph. The upper bound is sharp if the graph is connected. We are able to show a formula for the length of the parameterized linear code associated with any graph, in terms of the number of bipartite and non-bipartite components

Regularity and algebraic properties of certain lattice ideals

We study the regularity and the algebraic properties of certain lattice ideals. We establish a map I --> I\~ between the family of graded lattice ideals in an N-graded polynomial ring over a field K and the family of graded lattice ideals in a polynomial ring with the standard grading. This map is shown to preserve the complete intersection property and the regularity of I but not the degree. We relate the Hilbert series and the generators of I and I\~. If dim(I)=1, we relate the degrees of I and I\~. It is shown that the regularity of certain lattice ideals is additive in a certain sense. Then, we give some applications. For finite fields, we give a formula for the regularity of the vanishing ideal of a degenerate torus in terms of the Frobenius number of a semigroup. We construct vanishing ideals, over finite fields, with prescribed regularity and degree of a certain type. Let X be a subset of a projective space over a field K. It is shown that the vanishing ideal of X is a lattice ideal of dimension 1 if and only if X is a finite subgroup of a projective torus. For finite fields, it is shown that X is a subgroup of a projective torus if and only if X is parameterized by monomials. We express the regularity of the vanishing ideal over a bipartie graph in terms of the regularities of the vanishing ideals of the blocks of the graph.Comment: Bull. Braz. Math. Soc. (N.S.), to appea

Interactive computational modelling to improve teaching of physics and mathematics in marine geophysics

This study discusses the implementation of a learning sequence with interactive computational modelling activities in the context of introductory marine geophysics university courses. The application of two computer modelling systems, Modellus and Mirone, is considered for the introduction of mathematical physics models of interest in marine geophysics to students having only basic level knowledge of physics and mathematics and no prior knowledge of scientific computation. Modellus is used to compute the theoretical depth of the seafloor predicted using the plate cooling model, while is used to manipulate and display actual bathymetric data in the region of mid-ocean ridges. The combination of both software systems is illustrative and insightful of functionalities suitable to develop other computational modelling activities for marine geophysics as well as for other areas of the geosciences.FCT-projects [UID/GEO/50019/2019, UID/CED/02861/2019]info:eu-repo/semantics/publishedVersio

Al encuentro del ser recibido La fenomenología del sueño de María Zambrano en el Asesoramiento Ético y Filosófico

Este artículo pretende mostrar de qué forma la fenomenología del sueño de María Zambrano se convierte en el eje principal de la sexta instancia del método de Asesoramiento Filosófico Raciovitalismo Poético.This article intends to show how María Zambrano's phenomenology of dreams becomes the principal item of the six instance of the philosophical counseling method Poetical Ratiovitalism

Sobre la metáfora operante de los «claros del bosque» en Ortega y Gasset, Martin Heidegger y María Zambrano

En este artículo se pretende llevar a cabo un análisis comparado de la metáfora de los claros del bosque en el pensamiento de los filósofos María Zambrano, José Ortega y Gasset y Martin Heidegger trayendo a colación no solo los puntos de encuentro, sino también las sendas divergentes de los tres pensadores.The current article provides a comparative analysis of the metaphor forest glade in the work of the philosophers María Zambrano, José Ortega y Gasset and Martin Heidegger. The comparison not only reveals common ground but also the different paths the three thinkers pursue

A Formação Prática e a Supervisão da Formação

p.79-95O contexto actual da pós-modernidade, com a sua forte vivência de pluralismos de todas as naturezas representa um campo fértil para a exploração de uma perspectiva de formação de professores que se identifica com os princípios de uma escola reflexiva e com o paradigma do profissional reflexivo. A adopção do(s) modelos de supervisão que sustentema formação prática dos formandos deve assim merecer especial atenção por parte das instituições de formação.Neste processo formativo destacamos a necessidade de um trabalho colaborativo que envolva o supervisor institucional e supervisor cooperante, sendo ambos co-responsáveis pela formação pessoal e profissional dos futuros educadores.The present context of post-modern times, with its strong effervescence of pluralism of all types, represents a fertile field for the exploration of a perspective in the formation of teachers which can be identified with the main principles of a reflexive school together with the paradigm of a reflexive professional. The adoption of supervision models which are able to sustain the practical formation of teachers-to-be shall take into consideration by information institutions. In this sense, we stress the need of a collaborative work which shall involve both the institutional supervisor and cooperant supervisor, being both responsible for the personal and professional formation of future educators