855 research outputs found

    Sectorial Economic Growth and Employment in Mexico, 1996-2001

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    This paper shows the results from a study of the impact of sectorial economic growth on unemployment in Mexico for 1996-2001, by applying a disaggregate approach on data from the National Employment Survey (Encuesta Nacional de Empleo). The paper includes a discussion of the theoretical aspects of the sectorial contributions to growth (emphasizing the case of agriculture), as well as of the relationship between production and employment and the working of labor markets, but also describes the recent evolution of unemployment in Mexico. The core of the paper rests upon the analysis of panel data to estimate the open unemployment rate; it also includes the study of regional urban/rural growth through the analysis of unemployment in different sectors for ten different mexican regions. The results from the estimations at the regional level show that unemployment in Mexico has a statistically significant negative effect on sectorial economic growth. Also, evidence was found suggesting that promoting sectorial-regional (urban/rural) growth is an effective way to reduce unemployment. The paper, which is divided into five sections and draws upon some previous work on Okun’s law, also shows the impact that growth among economic activities within sectors has upon unemployment for the period.Sectorial Growth, Unemployment, Okun’s Law, Panel Data, National Employment Survey

    Seasonal variations in the biochemical composition of the serum of Mytilus galloprovincialis Lmk. and its relationship to the reproductive cycle and parasitic load

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    12 páginas, 4 figuras, 2 tablasThe levels of carbohydrate and protein in the blood serum of mussels (Mytilus galluprovincialis Lmk.) experimentally cultured at two depths in Galicia (NW Spain) were determined over a period of 1 year. The changes in concentration of total and reducing carbohydrate and protein exhibited an annual cycle; their values varied from 0.053 to 0.700 mg/ml, from 0.050 to 0.669 mg/ml and from 0.620 to 2.830 mg/ml respectively. Also, the concentrations of total carbohydrate and protein were greater in animals from 5 m depth than those from 2 m. Total and reducing carbohydrate were the components most affected by parasitism. The greatest effect on total carbohydrate concentration was detected in mussels affected by the parasites Mytilicola intestinalis and Marteilia refringens, which presented lower values in infected mussels than in non-infected ones, mainly in the summer months.This work was partially financed by CICYT (MEC, Spain) PPA86-0441 and the FAR project AQ- l-272 of DG-XIV from the EEC.Peer reviewe

    Carbon nanofiber-supported tantalum oxides as durable catalyst for the oxygen evolution reaction in alkaline media

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    Active and durable electrocatalysts for the oxygen evolution reaction (OER), capable of replacing noble metal catalysts, are required to develop efficient and competitive devices within the frame of the water electrolysis technology for hydrogen production. In this work, we have investigated tantalum based catalysts supported on carbon nanofibers (CNF) for the first time. The effect of CNF characteristics and the catalyst annealing temperature on the electrochemical response for the OER have been analyzed in alkaline environment using a rotating ring disc electrode (RRDE). The best OER activity and oxygen efficiency were found with a highly graphitic CNF, despite its lower surface area, synthesized at 700 °C, and upon a catalyst annealing temperature of 800 °C. The ordering degree of carbon nanofibers favors the production of oxygen in combination with a low oxygen content in tantalum oxides. The most active catalyst exhibited also an excellent durability.The authors want to thank the Ministerio de Economía, Industria y Competitividad (MICINN) and FEDER for the received funding in the project of reference ENE2017-83976-C2-1-R, and to the Gobierno de Aragón (DGA) for the funding to Grupo de Investigación Conversión de Combustibles ( T06_17R ). J.C. Ruiz-Cornejo acknowledges DGA for his PhD grant. D. Sebastián acknowledges the MICINN for the Ramón y Cajal research contract (RyC-2016-20944

    Hybrid chitosan derivative-carbon suport for oxygen reduction reactions

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    New hybrid chitosan derivative-carbon black was prepared and used as support for Pt nanoparticles. These catalysts improved the activity toward oxygen reduction reaction (ORR), compared with those of commercial Pt/C catalyst. The biopolymer chitosan provided an efficient and sustainable surface nitrogen source associated with the superior performance of the catalysts.Peer reviewe

    Inhibition in multiclass classification

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    The role of inhibition is investigated in a multiclass support vector machine formalism inspired by the brain structure of insects. The so-called mushroom bodies have a set of output neurons, or classification functions, that compete with each other to encode a particular input. Strongly active output neurons depress or inhibit the remaining outputs without knowing which is correct or incorrect. Accordingly, we propose to use a classification function that embodies unselective inhibition and train it in the large margin classifier framework. Inhibition leads to more robust classifiers in the sense that they perform better on larger areas of appropriate hyperparameters when assessed with leave-one-out strategies. We also show that the classifier with inhibition is a tight bound to probabilistic exponential models and is Bayes consistent for 3-class problems. These properties make this approach useful for data sets with a limited number of labeled examples. For larger data sets, there is no significant comparative advantage to other multiclass SVM approaches

    Inhibition in multiclass classification

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    The role of inhibition is investigated in a multiclass support vector machine formalism inspired by the brain structure of insects. The so-called mushroom bodies have a set of output neurons, or classification functions, that compete with each other to encode a particular input. Strongly active output neurons depress or inhibit the remaining outputs without knowing which is correct or incorrect. Accordingly, we propose to use a classification function that embodies unselective inhibition and train it in the large margin classifier framework. Inhibition leads to more robust classifiers in the sense that they perform better on larger areas of appropriate hyperparameters when assessed with leave-one-out strategies. We also show that the classifier with inhibition is a tight bound to probabilistic exponential models and is Bayes consistent for 3-class problems. These properties make this approach useful for data sets with a limited number of labeled examples. For larger data sets, there is no significant comparative advantage to other multiclass SVM approaches

    Engineering of gibberellin levels in citrus by sense and antisense

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    http://jxb.oxfordjournals.org/Carrizo citrange (Citrus sinensis x Poncirus trifoliata) is a citrus hybrid 4 widely used as a rootstock, whose genetic manipulation to improve 5 different growth characteristics is of high agronomic interest. In this work 6 we have produced transgenic Carrizo citrange plants overexpressing 7 sense and antisense CcGA20ox1 (a key enzyme of GA biosynthesis) 8 under control of the 35S promoter to modify plant architecture. As 9 expected, taller (sense) and shorter (antisense) phenotype correlated with 10 higher and lower levels, respectively, of active GA1 in growing shoots. In 11 contrast, other phenotypic characteristics seemed to be specific of citrus, 12 or different to those described for similar transgenics in other species. For 13 instance thorns, typical organs of citrus at juvenile stages, were much 14 longer in sense and shorter in antisense plants, and xylem tissue was 15 reduced in leaf and internode of sense plants. Antisense plants presented 16 a bushy phenotype, suggesting a possible effect of GAs on auxin 17 biosynthesis and/or transport. The main foliole of sense plants was longer, 18 although total leaf area was reduced. Leaf thickness was smaller in sense 19 and bigger in antisense plants due to changes in the spongy parenchyma. 20 Internode cell length was not altered in transgenic plants, indicating that in 21 citrus GAs regulate cell division rather than cell elongation. Interestingly, 22 the described phenotypes were not apparent when transgenic plants were 23 grafted on non-transgenic rootstock. This suggests that roots contribute to 24 the GA economy of aerial parts in citrus and opens the possibility of using 25 the antisense plants as dwarfing rootstocks.We thank J.A. Pina for technical assistance, and Dr. E. Carbonell and J. 34 Pérez for statistical analyses. This research was supported in part by grants CICYT AGL2003-01644, 1 INIA RTA04-13 and BIO2003-00151. C. 2 Fagoaga was recipient of an INIA-CCAA postdoctoral contract. I. Lliso was 3 recipient of an IVIA predoctoral fellowship. D.J. Iglesias and F.R. Tadeo 4 were recipients of INIA-CCAA and “Ramón y Cajal” MEC postdoctoral 5 contracts, respectively. 6 7Peer reviewe

    Estudios con fitoderivados en patología experimental: tendencias y recomendaciones

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    The university is an entity that allows the generation of knowledge through research, which responds to regional and global needs help making decisions and establishment of policies (1). To do this, universities are organized by research centers, which have lines of research; research thus become sustainable and contextual.La universidad es un ente que permite la generación de conocimientos a través de la investigación, la cual responde a necesidades regionales y globales que ayudarán a la toma de decisiones e instauración de políticas (1). Para ello, las universidades se organizan mediante centros de investigación, los cuales tienen líneas de investigación definidas; de este modo las investigaciones se hacen sostenibles y contextuales
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