The competitiveness of Spanish tomato export in the European Union

This paper examines the export performance of Spanish tomatoes in the European Union (EU). The origins and destinations of Spanish tomato exports are examined: Almeria is the main exporting province and Germany the biggest client. The performance of Spain’s North African competitors in the tomato market (mainly Morocco) is also examined, and the structural competitiveness of the countries that export tomatoes to the EU is analysed. Spain has the greatest advantage in this respect, and the largest inter-industry trade. An export model is developed. This model shows that the export of tomatoes from Almeria is not much influenced by shipments from Morocco.trade, price, competition, cointegration, Almería, strategy

Diseño del modelo de negocios y creación de empresa en el sector de autopartes y servicios para vehículos en Bogotá

El presente documento hace referencia a la ejecución del plan de negocios, para la creación de la empresa comercializadora de ofertas de productos en el sector de autopartes y servicios para motorizados en Bogotá, a través del portal web www.motorticket.co. Tener un sitio web no es garantía de ser competitivo, por eso fue necesario definir un producto a partir de sus atributos y características diferenciadoras, diseñado a la medida de los consumidores desde la planeación estratégica, la definición de la cadena de valor, los procesos operativos y el diseño del portal virtual; buscando el camino para cristalizar negocios, rentabilizando el sitio web y la empresa, acompañadas de aliados estrategicos que permiten el posicionamiento en el mercado.Magíster en Ingeniería IndustrialMaestrí

LpL^p-boundedness properties for the maximal operators for semigroups associated with Bessel and Laguerre operators

In this paper we prove that the generalized (in the sense of Caffarelli and Calder\'on) maximal operators associated with heat semigroups for Bessel and Laguerre operators are weak type (1,1). Our results include other known ones and our proofs are simpler than the ones for the known special cases.Comment: 8 page

Una descripción general del crecimiento económico en el África Subsahariana

Este artículo trata de servir de introducción a la situación de los países del área sub-sahariana que se caracterizan por tener el menor crecimiento económico y la más baja productividad mundial. En este contexto se analizan cuáles son las principales causas del atraso y se esbozan las soluciones más urgentes, que pasan, entre otras, por: i) el aumento de la inversión extranjera que será posible siempre que se mejoren las garantías de funcionamiento de las instituciones; y ii) el aumento del comercio intra-regional. También se realiza un análisis de correlación entre nivel económico, desarrollo humano y pobrezapobreza, crecimiento, comercio, cluster.

Reintegración sin desmovilización: el caso de las milicias populares de Medellín

Narratives on peace processes in Colombia do not often include the 1994 negotiations with the so-called “popular militia” in Medellín -- This article analyzes the development and results of this process, revises the explanations of its failure which were produced in that time, and proposes an interpretation that appeals to a more profound institutional structure that gave way to the negotiation of disorder and the privatization of security, thus developing a thesis suggested by María Teresa UribeLos recuentos sobre los procesos de paz en Colombia no siempre incluyen la negociación con las milicias populares de Medellín en 1994 -- Este artículo analiza los acuerdos y desarrollos de este proceso, revisa las explicaciones coetáneas de su fracaso y propone una interpretación que invoca una estructura institucional más profunda que dio lugar a la negociación del desorden y la privatización de la seguridad, en desarrollo de una tesis de María Teresa Urib

The open veins of Latin America: Long-term physical trade flows (1900-2016)

Latin America has long played a key role in the global provision of natural resources. Most of the continent's economies are net exporters of low-value, primary products and importers of manufactured goods at a high price. This pattern of specialised trade has highly negative consequences for economic development, the environment, and the local population's wellbeing. Yet to date, little empirical evidence has been collected on Latin America's total contribution to the rest of the world's regions in historical perspective. Applying the Material Flow Accounting methodology, this paper estimates the physical and monetary trade of 16 Latin American economies between 1900 and 2016. Our results show that: (i) yearly net exports of materials went from 4 Mt to 610 Mt between 1900 and 2016, and greatly accelerated since the World War II. (ii) Latin America is a net exporter of most types of materials (fossil fuels, non-energy minerals and biomass), so it harbours socio-environmental problems associated with different types of extractivism. (iii) Different regional export patterns exist: Andeans export subsoil (mining and energy carriers) while the rest export soil (land-based products). The countries with the lowest net exports are the smallest in size and with the highest population density. (iv) Europe and the USA have historically received most of the imports, but since the end of the twentieth century, the Southeast Asia region is the biggest importer of materials from Latin America. (v) The price received for exported material is much lower than the price paid for imported material; and (vi) various historical periods can be differentiated regarding the relationship between economic growth and physical trade balance

Rapid Magnetic Dispersive solid phase extraction to preconcentration/determination of Cd and Pb in aqueous samples

A new magnetic dispersive solid phase extraction (MDSPE) method and graphite furnace atomic absorption spectrometry (GFAAS) have been combined for the analysis of Cd and Pb in environmental samples. For the preconcentration, a shell structured Fe3O4@graphene oxide nanospheres was synthetized and characterized. The material was suspended in the ionic liquid 1-n-butyl-3-metilimidazolium tetrafluoroborate [BMIM][BF4], the obtained stable colloidal suspension is named ferrofluid. GO presents excellent adsorbent properties for organic species due to the presence of the electronic π system. For this reason, the organic ligand [1,5-bis-(2-dipyridyl) methylene] thiocarbonohydrazide (DPTH) was used in order to form organic complexes of Cd and Pb. Once the DPTH ligand has been added to sample, the ferrofluid was injected and finely dispersed in the sample solution in order to extract the formed chelates. The complete adsorption of the chelates took place within few seconds then, the solid was separated from the solution with the aid of a strong magnet. Cd and Pb ions were desorbed from the material with 1 mL of acid nitric 5% solution and quantified by GFAAS. All experimental and instrumental variables were optimized. The analytical performances of the optimized method were: EF (Enrichment factor): 200 with LODs (detection limit): 0.005 and 0.004 µg L-1 and LOQs (determination limit): 0.017 and 0.013 µg L-1, for Cd and Pb, respectively. The reliability of the developed procedure was tested by relative standard deviation (% RSD), which was found to be < 5%. The accuracy of the proposed method was verified using certified reference materials (SLRS-5, SPS-SW2, and BCR-723) and by determining the analyte content in spiked aqueous samples. Sea waters and tap water samples collected from Málaga (Spain) were also analysed. The determined values were in good agreement with the certified values and the recoveries for the spiked samples were around 100% in all cases.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Sistema de transmisión de datos topográficos desde un colector topográfico a la estación base utilizando la red de telefonía celular

It developed a communication system that has the functionality to transmit the information collected by a topographic manifold which is usually located at a distance of several kilometers from the base camp, in which information of all manifolds of the area was collect to be processed and stored for later analysis. The implementation of this device aims to reduce the time of data collection and the time for processing them. The tool used for this information is sent via text messages (SMS) from a cell phone taking advantage of the coverage of the cellular network that is implemented in the country. The process begins with data collection by the topographic manifold which is acquired by a communication card that was designed as an interface between the manifold and the cell, which takes the information provided by the manifold in plain text and is responsible to change the format so it can be captured by the cell and be sent via text messages to the cellular receptor that is located in the base station to the computer responsible for collecting the total information in the area.En este trabajo se desarrolla un sistema de comunicación que tiene como funcionalidad transmitir la información recolectada por un colector topográfico, que por lo general se encuentra ubicado a una distancia de varios kilómetros del campamento base, en el cual se recolecta la información de todos los colectores de la zona. La implementación de este dispositivo tiene como objetivo reducir los tiempos de recolección de datos y su procesamiento. La herramienta utilizada para él envió de esta información son los mensajes de texto (SMS) de un teléfono celular, aprovechando la cobertura de la red de telefonía celular. Para ello se diseñó una tarjeta de comunicación como interface entre el colector y el celular, la cual toma la información que suministra el colector en texto plano y se encarga de cambiarla de formato para que pueda ser capturada por el celular y ser enviada vía mensajes de texto al celular receptor que se encuentra ubicado en la estación base al computador encargado de recolectar la información total de la zona

Magnetic graphene oxide as a valuable material for the speciation of trace elements

Magnetic solid phase extraction (MSPE) has been explored for the application in preconcentration processes to achieve highly sensible analytical methods. Attending to the different magnetic adsorbent materials used in this field, functionalized magnetic graphene oxide (MGO) has proven to be effective for selective analysis and speciation of metals, metalloids, and derivatives in combination with several analytical techniques. Despite the increasing number of articles on speciation of trace elements using functionalized MGO as solid phase adsorbent, there are no dedicated reviews that cover the application of this novel nanomaterial, being this work pioneer in this area. This article provides a comprehensive review of the relevant literature related to the speciation of Al, Cr, As, Se, Ag, Cd, Hg, Tl and Pb, with special focus on species determined, toxicity, MGO functionalization, analytical performance, and applications, mainly to environmental and food samples. Finally, future challenges and trends related to this topic are shown.This work has been partially supported by the University of Malaga (I Plan Propio de Investigación y Transferencia, Proyecto Puente UMA and fellowship A.2.-2021 predoctoral contracts), FEDER funds, Junta de Andalucia, Project UMA18-FEDERJA-060 and the Spanish Ministerio de Ciencia y Tecnologia (fellowship FPU18/05371). Funding for open access charge: Universidad de Málaga / CBUA

Semiautomatic method for the ultra-trace arsenic speciation in environmental and biological samples via magnetic solid phase extraction prior to HPLC-ICP-MS determination

A novel magnetic functionalized material based on graphene oxide and magnetic nanoparticles (MGO) was used to develop a magnetic solid phase extraction method (MSPE) to enrich both, inorganic and organic arsenic species in environmental waters and biological samples. An automatic flow injection (FI) system was used to preconcentrate the arsenic species simultaneously, while the ultra-trace separation and determination of arsenobetaine (AsBet), cacodylate, AsIII and AsV species were achieved by high performance liquid chromatog raphy combined with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The sample was introduced in the FI system where the MSPE was performed, then 1 mL of eluent was collected in a chromatographic vial, which was introduced in the autosampler of HPLC-ICP-MS. Therefore, preconcentration and separation/deter mination processes were automatic and conducted separately. To the best of our knowledge, this is the first method combining an automatic MSPE with HPLC-ICP-MS for arsenic speciation, using a magnetic nanomaterial based on MGO for automatic MSPE. Under the optimized conditions, the LODs for the arsenic species were 3.8 ng L− 1 AsBet, 0.5 ng L− 1 cacodylate, 1.1 ng L− 1 AsIII and 0.2 ng L− 1 AsV with RSDs <5%. The developed method was validated by analyzing Certified Reference Materials for total As concentration (fortified lake water TMDA 64.3 and seawater CASS-6 NRC) and also by recovery analysis of the arsenic species in urine, well-water and seawater samples collected in Malaga. ´ The developed method has shown promise for routine monitoring of arsenic species in environmental waters and biological fluids.This work has been partially supported by the University of Malaga (Proyecto Puente UMA), FEDER funds, Junta de Andalucia, Project UMA18FEDERJA060 and the Spanish Ministerio de Ciencia y Tecnologia (fellowship FPU18/05371). Funding for open access charge: Universidad de Málaga / CBU