Buyer-supplier relationships influence on traceability implementation in the vegetable industry

The increasing importance of food safety has made traceability a crucial issue in the agri-business industry. In this article, we have analysed the factors that shape the buyer-supplier relationships, and how they influence the traceability of raw materials. In order to do so, first, we have made a literature review to develop an analytical framework. Next, we have carried out four case studies on vegetable firms with the purpose of uncovering the variables that characterise buyer-supplier relationships, and its influence on traceability in this sector. Finally, we have compared the observed links with the conceptual framework derived from the literature in order to build and improved model

A Panel Data Toolbox for MATLAB

Panel Data Toolbox is a new package for MATLAB that includes functions to estimate the main econometric methods of panel data analysis. The package includes code for the standard fixed, between and random effects estimation methods, as well as for the existing instrumental panel and new spatial panel. This paper describes the methodology and implementation of the functions and illustrates their use with well-known examples. We perform numerical checks against other popular commercial and free software in order to show the validity of the result

Urban patterns, population density and optimal city dimension: The case of public infrastructure

Determination of the optimal city size underlies the economic rationality of infrastructure provision by local governments. We investigate the existence of decreasing average costs resulting from economies of scale, associated with larger urban dimensions in terms of population and housing, and economies of density, brought about by reductions in urban dispersion, and calculate optimal population densities when providing basic infrastructure. The methodology relies on novel definitions of scale and density economies and their estimation by way of flexible translog cost functions, extensively applied in the literature dealing with the provision of services—i.e., utilities, but extended here to their supporting infrastructure. Our results unveil the existence of latent economies of scale and density resulting in a cost excess in the provision of infrastructure due to the effect of urban sprawl that translates into suboptimal city sizes. Based on these findings several policy guidelines rationalizing urban development are suggested. The model is illustrated using Spanish statistical data collected from the nationwide local infrastructure and equipment survey, and prices from a new database that uses engineering cost benchmarks.Urban patterns; Optimal urban density; Scale and density economies; Translog cost function.

Las metas en la reducción del prejuicio automático

Desde el enfoque de la cognición social se ha puesto de relieve que, por defecto, los estereotipos y los prejuicios se activan automáticamente, al tiempo que han proliferado los intentos por controlar las influencias automáticas no deseadas. En este marco, el presente estudio fue diseñado para evaluar la efectividad de un procedimiento de reducción automática del prejuicio, basado en la evocación de la experimentación de un fracaso en el logro de una meta. Distintas teorías de la discrepancia predicen que el perceptor llevará a cabo esfuerzos compensatorios en este tipo de situación. Los resultados evidencian, a partir de los datos recogidos con el Test de Asociación Implícita, que la estrategia aplicada produjo una reducción significativa del favoritismo endogrupal automático, sugiriendo la operatividad de algún tipo de compensación afectiva. En la discusión se subraya la contribución de este resultado al desarrollo teórico de la investigación sobre automaticidad y control

Modular construction survey

Los sistemas modulares son procedimientos constructivos en los cuales la unidad estructural fundamental del mismo se repite de una manera regular a lo largo de todo el proyecto. Los módulos pueden ser elementos de distinta naturaleza y geometría pero, suelen ser elementos de geometría rectangular como placas, paneles y losas. Estos sistemas constructivos presentan diferencias significativas con los sistemas tradicionales, dedicando un mayor énfasis en las fases de planificación y proyecto, para alcanzar elevadas celeridades durante el proceso constructivo. Los sistemas han mostrado grandes posibilidades, como demuestra la experiencia previa en varios países. Sistemas modulares como el Tilt-Up ocupan una posición remarcable en el mercado estadounidense y los sistemas de prefabricados gozan de una posición dominante en los países del norte de Europa, llegando en zonas como Suecia a representar el 90% de las construcciones realizadas. Sin embargo, son una modalidad constructiva de escasa difusión y estudio en España. Este estudio pretende ser una referencia, dado el extensivo análisis a sistemas representativos de construcción modular desde aspectos sociales, económicos, constructivos y estructurales

Vanishing Abelian integrals on zero-dimensional cycles

In this paper we study conditions for the vanishing of Abelian integrals on families of zero-dimensional cycles. That is, for any rational function $f(z)$, characterize all rational functions $g(z)$ and zero-sum integers $\{n_i\}$ such that the function $t\mapsto\sum n_ig(z_i(t))$ vanishes identically. Here $z_i(t)$ are continuously depending roots of $f(z)-t$. We introduce a notion of (un)balanced cycles. Our main result is an inductive solution of the problem of vanishing of Abelian integrals when $f,g$ are polynomials on a family of zero-dimensional cycles under the assumption that the family of cycles we consider is unbalanced as well as all the cycles encountered in the inductive process. We also solve the problem on some balanced cycles. The main motivation for our study is the problem of vanishing of Abelian integrals on single families of one-dimensional cycles. We show that our problem and our main result are sufficiently rich to include some related problems, as hyper-elliptic integrals on one-cycles, some applications to slow-fast planar systems, and the polynomial (and trigonometric) moment problem for Abel equation. This last problem was recently solved by Pakovich and Muzychuk (\cite{PM} and \cite{P}). Our approach is largely inspired by their work, thought we provide examples of vanishing Abelian integrals on zero-cycles which are not given as a sum of composition terms contrary to the situation in the solution of the polynomial moment problem.Comment: 35 pages, 1 figure; one reference added; abstract, introduction and structure change

Una experiencia de innovación de la docencia basada en el uso de un portal de Internet

Este artículo describe una experiencia de innovación didáctica consistente en el desarrollo y comprobación de la utilidad de un portal de política y legislación educativas (Polieduca), y la verificación de las capacidades que en mayor medida potencia este tipo de mediación neotecnológica. En el diseño del portal se incluyeron recursos de información, formación y comunicación, a modo de centro de coordinación de los medios que se iban a emplear en la asignatura afectada por la innovación (“Dimensiones, Modelos y Política educacional”, materia del 1er curso de la titulación de Psicopedagogía). Los resultados muestran que el portal funcionó como facilitador de diversas capacidades. Específicamente, 1) apoyó el aprendizaje autónomo; 2) incrementó la participación; 3) orientó las estrategias de búsqueda y selección de la información; 4) desarrolló habilidades críticas; 5) estimuló el aprendizaje cooperativo a través de la interactividad; y 6) facilitó la construcción de esquemas comprensivos y explicativos de la realidad político- educativa. Adicionalmente, el medio evaluado ejerció una función motivacional y se adaptó al ritmo de aprendizaje de cada estudiante. En resumen, Polieduca asumió muchas de las características que se atribuyen a los sistemas autónomos de aprendizaje

La evaluación y acreditación de la educación superior ecuatoriana y la producción editorial

This article exposes the features of editorial production in public and private universities in Ecuador, in the context of evaluation and quality assurance in higher education, using two different types of material and data: a. A review of the data on book production, titles and areas of knowledge; b. UPS’ accreditation experience with indicators on scientific research, regional research and refereed books. By doing this, we have checked that editorial production has increased and that social sciences prevail in editorial production are in social sciences. Finally, we foresee that the overvaluation of indexed articles and topological restrictions of peer-reviewed books will discourage the development of university editorials. The hypothesis is as follows: the evaluation and accreditation model will be able to stimulate the editorial production and improve research indicators to the extent that it assigns greater valuation to peer-reviewed books and expands its typology

Manganese and zinc in acidic agricultural soils from Central Spain: Distribution and phytoavailability prediction with chemical extraction tests

The extractability and distribution of manganese (Mn) and zinc (Zn) were evaluated in acidic agricultural soils from Central Spain. Both single (0.1 M hydrochloride [HCl] and 0.05 M ethylenediaminetetraacetate [EDTA]) and sequential extraction procedures (SEP) (modified Tessier procedure and Community Bureau of Reference [BCR] protocol) were applied to 29 representative soils that belong to the Alfisol, Inceptisol, and Entisol orders. Average relative Mn extractabilities with respect to the total content (16.6% for HCl and 31.9% for EDTA) were higher than those of Zn (7.7% for HCl and 6.5% for EDTA). Manganese was mainly released in the oxide-bound phase of both SEP (33.1% for modified Tessier and 48.9% for BCR), whereas Zn was predominantly found in the residual fraction (49.1% for modified Tessier and 31.4% for BCR). Significant correlations were only found between the amounts of extractable Zn and the oxide-bound fraction in both SEP. Few relationships were established between Zn fractions extracted by the BCR procedure and those obtained with the Tessier method. Both metal concentrations in spring barley (Hordeum vulgare L., cv Beka) grown in 11 selected soils and the calculated soil/plant transfer coefficients (soil/plant concentration factor (CF), mean values of 31.2 for Mn and 196 for Zn) were poorly (or not at all) correlated with the different extracted soil fractions (single and sequential). A number of empirical equations have been obtained by regression analyses to predict the Mn and Zn uptake by barley, with soil metal forms and some soil characteristics as components (pH for Mn and organic matter for Zn). Values of R2 in the equations were relatively low (<68%). Single-extraction techniques produced worse results than SEP for the evaluation of Mn phytoavailability. The modified Tessier procedure provided better predictions of Zn uptake by plants than BCR, but not better than those obtained with the HCl extraction method

El estatuto de la mujer soltera o viuda en el derecho privado español

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Derecho, leída en 1974.Fac. de DerechoTRUEProQuestpu