162 research outputs found

    Degree of hydration-based creep modeling of concrete with blended binders : from concept to real applications

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    The mechanical behavior of hardening concrete is to a large extent determined by the evolving microstructure as a result of the hydration process. For traditional binder systems, consisting of Portland cement or blast furnace slag cement, the degree of hydration is known to be a fundamental parameter in this respect, enabling a detailed study and accurate prediction of the early-age mechanical behavior, including basic creep. Nowadays, in view of improved sustainability of cementitious materials, binder systems tend to become more complex, consisting of a blend of different powders. As the hydration process and microstructure development are influenced by the inclusion of powders into the binder, the question is raised whether the degree of hydration concept is still applicable to concrete based on complex blended binder systems. In this paper, some experimental results are summarized and the application to real structures is illustrated. Basic creep of hardening concrete with complex blended binders can still be modeled following the degree of hydration concept

    Tropical analogues of a Dempe-Franke bilevel optimization problem

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    We consider the tropical analogues of a particular bilevel optimization problem studied by Dempe and Franke and suggest some methods of solving these new tropical bilevel optimization problems. In particular, it is found that the algorithm developed by Dempe and Franke can be formulated and its validity can be proved in a more general setting, which includes the tropical bilevel optimization problems in question. We also show how the feasible set can be decomposed into a finite number of tropical polyhedra, to which the tropical linear programming solvers can be applied.Comment: 11 pages, 1 figur

    The level set method for the two-sided eigenproblem

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    We consider the max-plus analogue of the eigenproblem for matrix pencils Ax=lambda Bx. We show that the spectrum of (A,B) (i.e., the set of possible values of lambda), which is a finite union of intervals, can be computed in pseudo-polynomial number of operations, by a (pseudo-polynomial) number of calls to an oracle that computes the value of a mean payoff game. The proof relies on the introduction of a spectral function, which we interpret in terms of the least Chebyshev distance between Ax and lambda Bx. The spectrum is obtained as the zero level set of this function.Comment: 34 pages, 4 figures. Changes with respect to the previous version: we explain relation to mean-payoff games and discrete event systems, and show that the reconstruction of spectrum is pseudopolynomia

    Why Are Computational Neuroscience and Systems Biology So Separate?

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    Despite similar computational approaches, there is surprisingly little interaction between the computational neuroscience and the systems biology research communities. In this review I reconstruct the history of the two disciplines and show that this may explain why they grew up apart. The separation is a pity, as both fields can learn quite a bit from each other. Several examples are given, covering sociological, software technical, and methodological aspects. Systems biology is a better organized community which is very effective at sharing resources, while computational neuroscience has more experience in multiscale modeling and the analysis of information processing by biological systems. Finally, I speculate about how the relationship between the two fields may evolve in the near future

    Recent advances in Pichia pastoris as host for heterologous expression system for lipases : a review

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    The production of heterologous lipases is one of the most promising strategies to increase the productivity of the bioprocesses and to reduce costs, with the final objective that more industrial lipase applications could be implemented. In this chapter, an overview of the new success in synthetic biology, with traditional molecular genetic techniques and bioprocess engineering in the last 5 years in the cell factory Pichia pastoris, the most promising host system for heterologous lipase production, is presented. The goals get on heterologous Candida antarctica, Rhizopus oryzae, and Candida rugosa lipases, three of the most common lipases used in biocatalysis, are showed. Finally, new cell factories producing heterologous lipases are presented

    Food and nutrition security discursive frames in the context of the Spanish economic crisis

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    [EN] The recent economic crisis in Spain has provoked a number of food and nutrition security (FNS) impacts that have fuelled a fragmented landscape of food-related debates, although these have not taken the form of a coherent and allembracing public discussion on national food security. This paper is an inductive analysis of such debates, mostly based on media coverage, in an attempt to disentangle the different discourse frames on FNS in Spain, and the role played by the economic crisis in the shaping and underpinning of such frames. For this purpose a frame matrix was constructed, paying particular attention to the stakeholders governance claims in order to confront frame-specific problems. Results show how stakeholders have used elements of the crisis to underpin or reinterpret their core arguments. In addition, governance claims have concentrated on the malfunctioning of the food chain, mostly due to unequal bargaining power, and the way this could be putting at risk crucial components of the food system and future FNS. Also, the short-termism of most stakeholders approaches obscures the long run threats to the Spanish food system.This research is part of the project "Assessment of the impact of global drivers of change on Europe's food security" (TRANSMANGO), granted by the EU under 7th Framework Programme, theme KBBE.2013.2.5-01, Grant agreement no: 613532. Authors gratefully appreciate the comments and suggestions made by the three anonymous reviewers and the editors of the Journal.OOrtiz Miranda, D.; Moreno Pérez, OM.; Arnalte Alegre, EV. (2016). Food and nutrition security discursive frames in the context of the Spanish economic crisis. Food Security. 8(3):665-677. https://doi.org/10.1007/s12571-016-0574-xS66567783Antentas, J. M., & Vivas, E. (2014). Impacto de la crisis en el derecho a una alimentación sana y saludable. Informe SESPAS 2014. Gaceta Sanitaria, 28(S1), 58–61.Brunori, G., Malandrin, V., & Rossi, A. (2013). Trade-off or convergence? The role of food security in the evolution of food discourse in Italy. Journal of Rural Studies, 29, 19–29.Candel, J. J., Breeman, G. E., Stiller, S. J., & Termeer, C. J. (2014). Disentangling the consensus frame of food security: the case of the EU common agricultural policy reform debate. Food Policy, 44, 47–58.CFS – Committee on World Food Security (2012). Coming to Terms with Terminology. http://www.fao.org/fsnforum/sites/default/files/file/Terminology/MD776(CFS___Coming_to_terms_with_Terminology).pdf . Accessed 6 Oct 2015.Cussó, X., & Garrabou, R. (2009). Dieta mediterránea y transición nutricional moderna en España. In L. G. Zubero, R. H. García, & J. M. Lázaro (Eds.), Economía Alimentaria en España durante el siglo XX (pp. 25–63). Madrid: MARM.De Schutter, O. (2014). The specter of productivism and food democracy. Wisconsin Law Review, 199, 199–233.DEFRA (2008). Ensuring the UK’s food security in a changing world. London: A Defra Discussion Paper.Díaz-Méndez, C., & Gómez-Benito, C. (2010). Nutrition and the Mediterranean diet. A historical and sociological analysis of the concept of a “healthy diet” in Spanish society. Food Policy, 35(5), 437–447.Dibden, J., Gibbs, D., & Cocklin, C. (2013). Framing GM crops as food security solution. Journal of Rural Studies, 29, 59–70.Ericksen, P. J. (2008). Conceptualizing food systems for global environmental change research. Global Environmental Change, 18, 234–245.FAO (2014). The State of the World’s Land and Water Resources for Food and Agriculture. http://www.fao.org/nr/solaw/maps-and-graphs/en/ . Accessed 25 Feb 2015.Fish, R., Lobley, M., & Winter, M. (2013). A license to produce? Farmer interpretations of the new food security agenda. Journal of Rural Studies, 29, 40–49.Grando, S., & Colombo, L. (2015). National Report. Italy. WP2 report Transmango EU-FP7.GREENPEACE (2014). Alimentos bajo amenaza. Valor económico de la polinización y vulnerabilidad de la agricultura española ante el declive de las abejas y otros polinizadores. Madrid: Greenpeace.Hertel, T. W. (2015). The challenges of sustainably feeding a growing planet. Food Security, 7, 185–198.Hispacoop (2012). Estudio sobre desperdicio de alimentos en los hogares. Madrid: Confederación Española de Cooperativas de Consumidores y Usuarios.Lang, T., & Heasman, M. (2004). Food wars. The global battle for mouths, Minds and Markets. London: Earthscan.Lawrence, G., & McMichael, P. (2012). The question of food security. International Journal of Sociology of Agriculture & Food, 19(2), 135–142.MAGRAMA. (2014). La balanza commercial agroalimentaria en 2013. Madrid.Maye, D., & Kirwan, J. (2013). Food security: a fractured consensus. Journal of Rural Studies, 29, 1–6.McKeon, N. (2015). Food security governance: empowering communities, regulating corporations. New York: Routledge.Mooney, P. H., & Hunt, S. A. (2009). Food security: the elaboration of contested claims to a consensus frame. Rural Sociology, 74(4), 469–497.Moreno, O. (2013). Reproducing productivism in Spanish agricultural systems. In D. Ortiz, A. Moragues, & E. Arnalte (Eds.), Agriculture in Mediterranean Europe: between old and new paradigms. Research in rural sociology and development (pp. 121–147). Bingley: Emerald Group Publishing Limited.Muñoz, C., & Sosvilla, S. (2014). Alimentamos el futuro. Informe económico 2013. Madrid: FIAB.OECC - Oficina Española de Cambio Climático (2006). Plan Nacional de Adaptación al Cambio Climático. Madrid.OECC-UCLM (2005). Evaluación Preliminar de los Impactos en España por Efecto del Cambio Climático. Madrid: MAGRAMA.Pangaribowo, E. H., Gerber, N., & Torero, M. (2013). Food and Nutrition Security Indicators: A Review. ZEF working paper no 108. Bonn: ZEF.Sáez-Almendros, S., Obrador, B., Bach-Faig, A., & Serra-Majem, L. (2013). Environmental footprints of Mediterranean versus Western dietary patterns: beyond the health benefits of the Mediterranean diet. Environmental Health, 12, 118.Shepherd, B. (2012). Thinking critically about food security. Security Dialogue, 43(3), 195–212.Sineiro, F. (2012). Situación actual, retos y perspectivas del vacuno de leche. Available at http://www.eumedia.es/portales/files/documentos/2-FSineiro.pdf . Accessed 19 Nov 2015.Van Gorp, B. (2007). The constructionist approach to framing: bringing culture back. Journal of Communication, 57, 60–78.Van Gorp, B., & van der Goot, M. J. (2012). Sustainable food and agriculture: Stakeholder’s frames. Communication, Culture & Critique, 5, 127–148.Vidal, R., Moliner, E., Pikula, A., Mena-Nieto, A., & Ortega, A. (2015). Comparison of the carbon footprint of different patient diets in a Spanish hospital. Journal of Health Services Research & Policy, 20(1), 39–44

    Effects of Active Conductance Distribution over Dendrites on the Synaptic Integration in an Identified Nonspiking Interneuron

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    The synaptic integration in individual central neuron is critically affected by how active conductances are distributed over dendrites. It has been well known that the dendrites of central neurons are richly endowed with voltage- and ligand-regulated ion conductances. Nonspiking interneurons (NSIs), almost exclusively characteristic to arthropod central nervous systems, do not generate action potentials and hence lack voltage-regulated sodium channels, yet having a variety of voltage-regulated potassium conductances on their dendritic membrane including the one similar to the delayed-rectifier type potassium conductance. It remains unknown, however, how the active conductances are distributed over dendrites and how the synaptic integration is affected by those conductances in NSIs and other invertebrate neurons where the cell body is not included in the signal pathway from input synapses to output sites. In the present study, we quantitatively investigated the functional significance of active conductance distribution pattern in the spatio-temporal spread of synaptic potentials over dendrites of an identified NSI in the crayfish central nervous system by computer simulation. We systematically changed the distribution pattern of active conductances in the neuron's multicompartment model and examined how the synaptic potential waveform was affected by each distribution pattern. It was revealed that specific patterns of nonuniform distribution of potassium conductances were consistent, while other patterns were not, with the waveform of compound synaptic potentials recorded physiologically in the major input-output pathway of the cell, suggesting that the possibility of nonuniform distribution of potassium conductances over the dendrite cannot be excluded as well as the possibility of uniform distribution. Local synaptic circuits involving input and output synapses on the same branch or on the same side were found to be potentially affected under the condition of nonuniform distribution while operation of the major input-output pathway from the soma side to the one on the opposite side remained the same under both conditions of uniform and nonuniform distribution of potassium conductances over the NSI dendrite

    Differential pattern and prognostic significance of CD4+, FOXP3+ and IL-17+ tumor infiltrating lymphocytes in ductal and lobular breast cancers

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    <p>Abstract</p> <p>Background</p> <p>Clinical relevance of tumor infiltrating lymphocytes (TILs) in breast cancer is controversial. Here, we used a tumor microarray including a large series of ductal and lobular breast cancers with long term follow up data, to analyze clinical impact of TIL expressing specific phenotypes and distribution of TILs within different tumor compartments and in different histological subtypes.</p> <p>Methods</p> <p>A tissue microarray (TMA) including 894 ductal and 164 lobular breast cancers was stained with antibodies recognizing CD4, FOXP3, and IL-17 by standard immunohistochemical techniques. Lymphocyte counts were correlated with clinico-pathological parameters and survival.</p> <p>Results</p> <p>CD4<sup>+ </sup>lymphocytes were more prevalent than FOXP3<sup>+ </sup>TILs whereas IL-17<sup>+ </sup>TILs were rare. Increased numbers of total CD4<sup>+ </sup>and FOXP3<sup>+ </sup>TIL were observed in ductal, as compared with lobular carcinomas. High grade (G3) and estrogen receptor (ER) negative ductal carcinomas displayed significantly (<it>p </it> < 0.001) higher CD4<sup>+ </sup>and FOXP3<sup>+ </sup>lymphocyte infiltration while her2/neu over-expression in ductal carcinomas was significantly (<it>p </it> < 0.001) associated with higher FOXP3<sup>+ </sup>TIL counts. In contrast, lymphocyte infiltration was not linked to any clinico-pathological parameters in lobular cancers. In univariate but not in multivariate analysis CD4<sup>+ </sup>infiltration was associated with significantly shorter survival in patients bearing ductal, but not lobular cancers. However, a FOXP3<sup>+</sup>/CD4<sup>+ </sup>ratio > 1 was associated with improved overall survival even in multivariate analysis (<it>p </it>= 0.033).</p> <p>Conclusions</p> <p>Ductal and lobular breast cancers appear to be infiltrated by different lymphocyte subpopulations. In ductal cancers increased CD4<sup>+ </sup>and FOXP3<sup>+ </sup>TIL numbers are associated with more aggressive tumor features. In survival analysis, absolute numbers of TILs do not represent major prognostic indicators in ductal and lobular breast cancer. Remarkably however, a ratio > 1 of total FOXP3<sup>+</sup>/CD4<sup>+ </sup>TILs in ductal carcinoma appears to represent an independent favorable prognostic factor.</p
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