197 research outputs found
A New Method to Solve Fuzzy Interval Flexible Linear Programming Using a Multi-Objective Approach
The first author would like to appreciate from the research grant of University of Mazandaran. The research of Jose Luis Verdegay is supported in part by the project TIN2017-86647-P (Spanish Ministry of Economy and Competitiveness) which includes FEDER funds from the European Union.Recently fuzzy interval flexible linear programs have attracted many
interests. These models are an extension of the classical linear programming
which deal with crisp parameters. However, in most of the
real-world applications, the nature of the parameters of the decisionmaking
problems is generally imprecise. Such uncertainties can lead
to increased complexities in the related optimisation efforts. Simply
ignoring these uncertainties is considered undesired as it may result
in inferior or wrong decisions. Therefore, inexact linear programming
methods are desired under uncertainty. In this paper,weconcentrate
a fuzzy flexible linear programming model with flexible constraints
and the interval objective function and then propose a new solving
approach based on solving an associated multi-objective model.
Finally, numerical example is included to illustrate the mentioned
solving process.University of MazandaranSpanish Ministry of Economy and Competitiveness TIN2017-86647-PEuropean Commissio
COMPUTATION OF THE REFLECTANCE AND TRANSMITTANCE FOR AN INHOMOGENEOUS LAYERED MEDIUM WITH TURNING POINT S USING THE WKB AND SPPS METHODS
Electromagnetic wave propagation is currently present in the vast majority of situations which occur in veryday life, whether in mobile communications, DTV, satellite tracking, broadcasting, etc. Because of this the study of increasingly complex means of propagation of lectromagnetic waves has become necessary in order to optimize resources and increase the capabilities of the devices as required by the growing demand for such services.
Within the electromagnetic wave propagation different parameters are considered that characterize it under various circumstances and of particular importance are the reflectance and transmittance. There are several methods or the analysis of the reflectance and transmittance such as the method of approximation by boundary condition, the plane wave expansion method (PWE), etc., but this work focuses on the WKB and SPPS methods.
The implementation of the WKB method is relatively simple but is found to be relatively efficient only when working at high frequencies. The SPPS method (Spectral Parameter Powers Series) based on the theory of pseudoanalytic functions, is used to solve this problem through a new representation for solutions of Sturm Liouville equations and has recently proven to be a powerful tool to solve different boundary value and eigenvalue problems. Moreover, it has a very suitable structure for numerical implementation, which in this case took place in the Matlab software for the valuation of both conventional and turning points profiles.
The comparison between the two methods allows us to obtain valuable information about their perfor mance which is useful for determining the validity and propriety of their application for solving problems where these parameters are calculated in real life applications
COMPUTATION OF THE REFLECTANCE AND TRANSMITTANCE FOR AN INHOMOGENEOUS LAYERED MEDIUM WITH TURNING POINT S USING THE WKB AND SPPS METHODS
Electromagnetic wave propagation is currently present in the vast majority of situations which occur in veryday life, whether in mobile communications, DTV, satellite tracking, broadcasting, etc. Because of this the study of increasingly complex means of propagation of lectromagnetic waves has become necessary in order to optimize resources and increase the capabilities of the devices as required by the growing demand for such services.
Within the electromagnetic wave propagation different parameters are considered that characterize it under various circumstances and of particular importance are the reflectance and transmittance. There are several methods or the analysis of the reflectance and transmittance such as the method of approximation by boundary condition, the plane wave expansion method (PWE), etc., but this work focuses on the WKB and SPPS methods.
The implementation of the WKB method is relatively simple but is found to be relatively efficient only when working at high frequencies. The SPPS method (Spectral Parameter Powers Series) based on the theory of pseudoanalytic functions, is used to solve this problem through a new representation for solutions of Sturm Liouville equations and has recently proven to be a powerful tool to solve different boundary value and eigenvalue problems. Moreover, it has a very suitable structure for numerical implementation, which in this case took place in the Matlab software for the valuation of both conventional and turning points profiles.
The comparison between the two methods allows us to obtain valuable information about their perfor mance which is useful for determining the validity and propriety of their application for solving problems where these parameters are calculated in real life applications
Estructura financiera y logro empresarial en cooperativas agrarias: una aproximaciĂłn empĂrica
[EN] This paper analyzes the economic and financial information of a sample of Spanish agricultural co-operatives in order to identify the variables that determine the nature and composition of its financial structure. A new variable named âbusiness achievementâ has been defined using the statistical technique of principal component analysis (PCA); this, and other ratios, have been used in the regression models. Results show no relationship between financial structure and âbusiness achievementâ, but they support the Pecking order theory, thus validating the hypothesis that, in absence of self-financing, the prevalent funding sources in agricultural cooperatives are debt and capitalization. Also, in line with the Agency theory, it has been shown that in these entities growths in sales, and therefore cash flow generation, lead to higher short-term debt, while the use of long-term debt decreases.[ES] Este trabajo utiliza la informaciĂłn econĂłmico-financiera de una muestra de cooperativas agrarias españolas para identificar las variables que determinan la naturaleza y composiciĂłn de su estructura financiera. Se define una variable relativa al logro empresarial, a partir de la tĂ©cnica estadĂstica del anĂĄlisis de componentes principales que, junto con otros ratios, se introduce en los modelos de regresiĂłn. Los resultados no evidencian relaciĂłn entre estructura financiera y logro empresarial, pero sĂ corroboran la teorĂa del Pecking order, apoyando la hipĂłtesis del endeudamiento y la capitalizaciĂłn como fuentes de financiaciĂłn predominantes. TambiĂ©n se verifica la TeorĂa de la agencia, ya que crecimientos de ventas conllevan un mayor endeudamiento a corto plazo.Los autores agradecen los comentarios anĂłnimos de los revisores de la revista. Este trabajo se enmarca dentro del Proyecto DER2008-03475 âPĂ©rdidas, disoluciĂłn e insolvencia en la sociedad cooperativaâ, financiado por el Ministerio de Ciencia e InnovaciĂłn (IV Plan Nacional de InvestigaciĂłn CientĂfica, Desarrollo e InnovaciĂłn TecnolĂłgica 2008-2011).Lajara-Camilleri, N.; Mateos-Ronco, A. (2012). Financial structure and business achievement in agricultural cooperatives: an empirical approach. EconomĂa Agraria y Recursos Naturales - Agricultural and Resource Economics. 12(2):77-101. https://doi.org/10.7201/earn.2012.02.04SWORD7710112
Impact of a probiotic fermented milk in the gut ecosystem and in the systemic immunity using a non-severe protein-energy-malnutrition model in mice
<p>Abstract</p> <p>Background</p> <p>Malnutrition affects the immune response, causing a decrease of defence mechanisms and making the host more susceptible to infections. Probiotics can reconstitute the intestinal mucosa and stimulate local and systemic immunity. The aim of this work was evaluate the effects of a probiotic fermented milk as a complement of a re-nutrition diet, on the recovery of the intestinal barrier, and mucosal and systemic immune functions in a murine model of non-severe protein-energy-malnutrition. Its potential protection against <it>Salmonella enterica </it>serovar Typhimurium (<it>S</it>. Typhimurium) infection was also analyzed.</p> <p>Methods</p> <p>Mice were undernourished and divided into 3 groups according to the dietary supplement received during re-nutrition (milk, probiotic fermented milk or its bacterial free supernatant) and compared to well-nourished and malnourished mice. They were sacrificed previous to the re-nutrition and 5 days post re-nutrition. The phagocytic activity of macrophages from spleen and peritoneum and the changes in the intestinal histology and microbiota were evaluated. Different immune cell populations and cytokine productions were analyzed in the small intestine tissues. The effect of the re-nutrition supplements on the systemic immunity using OVA antigen and against an infection with <it>S. </it>Typhimurium was also studied.</p> <p>Results</p> <p>Probiotic fermented milk was the most effective re-nutrition diet that improved the intestinal microbiota. Its administration also increased the number of IgA+ cells, macrophages and dendritic cells. The production of different cytokine (IFN-γ, TNF-α, IL-12) by these cells and the phagocytic activity in peritoneum and spleen was also increased. This re-nutrition diet also stimulated the systemic immune response against OVA antigen which was diminished after the malnutrition period and also improved the host response against <it>S. </it>Typhimurium, decreasing the spread of pathogenic bacteria to the liver and the spleen. The importance of the metabolites released during milk fermentation was also demonstrated through the analysis of the bacterial free supernatant obtained from the probiotic fermented milk, but the whole product showed the best effects in the parameters evaluated in this study.</p> <p>Conclusions</p> <p>The administration of probiotic fermented milk as a dietary supplement during the re-nutrition process in a murine immunodeficiency model by malnutrition could be a good adjuvant diet to improve the gut and systemic immune response for the protection against <it>Salmonella </it>infection.</p
Structure-guided design and optimization of small molecules targeting the protein-protein interaction between the von hippel-lindau (VHL) E3 ubiquitin ligase and the hypoxia inducible factor (HIF) alpha subunit with in vitro nanomolar affinities
E3 ubiquitin ligases are attractive targets in the ubiquitin-proteasome system, however, the development of small-molecule ligands has been rewarded with limited success. The von Hippel-Lindau protein (pVHL) is the substrate recognition subunit of the VHL E3 ligase that targets HIF-1α for degradation. We recently reported inhibitors of the pVHL:HIF-1α interaction, however they exhibited moderate potency. Herein, we report the design and optimization, guided by X-ray crystal structures, of a ligand series with nanomolar binding affinities
Mechanism of action of probiotics
The modern diet doesn't provide the required amount of beneficial bacteria. Maintenance of a proper microbial ecology in the host is the main criteria to be met for a healthy growth. Probiotics are one such alternative that are supplemented to the host where by and large species of Lactobacillus, Bifidobacterium and Saccharomyces are considered as main probiotics. The field of probiotics has made stupendous strides though there is no major break through in the identification of their mechanism of action. They exert their activity primarily by strengthening the intestinal barrier and immunomodulation. The main objective of the study was to provide a deep insight into the effect of probiotics against the diseases, their applications and proposed mechanism of action
Converting simulated total dry matter to fresh marketable yield for field vegetables at a range of nitrogen supply levels
Simultaneous analysis of economic and environmental performance of horticultural crop production requires qualified assumptions on the effect of management options, and particularly of nitrogen (N) fertilisation, on the net returns of the farm. Dynamic soil-plant-environment simulation models for agro-ecosystems are frequently applied to predict crop yield, generally as dry matter per area, and the environmental impact of production. Economic analysis requires conversion of yields to fresh marketable weight, which is not easy to calculate for vegetables, since different species have different properties and special market requirements. Furthermore, the marketable part of many vegetables is dependent on N availability during growth, which may lead to complete crop failure under sub-optimal N supply in tightly calculated N fertiliser regimes or low-input systems. In this paper we present two methods for converting simulated total dry matter to marketable fresh matter yield for various vegetables and European growth conditions, taking into consideration the effect of N supply: (i) a regression based function for vegetables sold as bulk or bunching ware and (ii) a population approach for piecewise sold row crops. For both methods, to be used in the context of a dynamic simulation model, parameter values were compiled from a literature survey. Implemented in such a model, both algorithms were tested against experimental field data, yielding an Index of Agreement of 0.80 for the regression strategy and 0.90 for the population strategy. Furthermore, the population strategy was capable of reflecting rather well the effect of crop spacing on yield and the effect of N supply on product grading
Genetic transfer from several apomictic tetraploid Paspalum species to an elite group of sexual plants
Basic findings from classical genetic studies are available for exploiting apomixis in the breeding of several forage grass genera. Most Paspalum species are multiploid with a sexual diploid cytotype and conspecific apomictic polyploid (mainly tetraploid) cytotypes. Experimental tetraploidized diploids reproduce sexually and, when crossed with natural apomictic tetraploids, yield hybrid populations that segregate for reproductive mode. Genetic studies indicated that apomixis is inherited as a monogenic dominant factor. We recombined 50 selected sexual hybrids obtained from crosses between a tetraploidized sexual genotype of P. plicatulum and 9 natural apomictic tetraploid accessions of 6 species of the Plicatula group. A synthetic sexual tetraploid population (SSTP) of 600 individuals from mixed seed of the 50 intercrossed hybrids was space-planted in the field. Based on evaluations of plant vigor, seed set, ergot tolerance, regrowth after flowering, and cold tolerance, 31 plants were selected. Crosses between most selected plants and two testers, which belonged to P. guenoarum, were performed, and the generated progeny was planted into the field following a randomized block design with 3 replications. The progeny test was evaluated for seed fertility, biomass yield, and cold tolerance. This procedure allowed selection of 10 elite plants from the SSTP. These plants should contain genes recombined from six apomictic species, without the genetic determinants for apomixis. They may be polycrossed to generate an improved sexual population, or crossed with other apomictic genotypes to obtain improved apomictic hybrids.Fil: Novo, Patricia Elda. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BotĂĄnica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de BotĂĄnica del Nordeste; ArgentinaFil: Acuña, Carlos Alberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BotĂĄnica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de BotĂĄnica del Nordeste; ArgentinaFil: Urbani, Mario Hugo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BotĂĄnica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de BotĂĄnica del Nordeste; ArgentinaFil: Galdeano, Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BotĂĄnica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de BotĂĄnica del Nordeste; ArgentinaFil: Espinoza, Francisco. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BotĂĄnica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de BotĂĄnica del Nordeste; ArgentinaFil: Quarin, Camilo Luis. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BotĂĄnica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de BotĂĄnica del Nordeste; Argentin
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