1,160 research outputs found

    Spectral problem for the complex mKdV equation: singular manifold method and Lie symmetries

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    This article addresses the study of the complex version of the modified Korteweg-de Vries equation using two different approaches. Firstly, the singular manifold method is applied in order to obtain the associated spectral problem, binary Darboux transformations and τ\tau-functions. The second part concerns the identification of the classical Lie symmetries for the spectral problem. The similarity reductions associated to these symmetries allow us to derive the reduced spectral problems and first integrals for the ordinary differential equations arising from such reductions.Comment: This article is intended to be published in the special issue dedicated to Prof. Decio Levi (in Open Communications in Nonlinear Mathematical Physics

    Mejoramiento genético asistido para características reproductivas de animales domésticos : Marker assisted selection for reproductive traits in domestic animal

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    En los sistemas de producción animal, las características de reproducción influyen significativamente en su eficiencia y rentabilidad. La reproducción como herramienta de cambio genético necesariamente requiere de estrategias que identifiquen la variabilidad genética de los caracteres de interés; sin embargo, debido a su naturaleza compleja todos los caracteres reproductivos requieren del entendimiento de su arquitectura genética, condición que por su baja heredabilidad resulta complejo por métodos convencionales. La biotecnología genómica en la actualidad propone el mejoramiento genético sustantivo por medio del uso e implementación de marcadores genéticos, sobre todo del tipo SNP. En los últimos años se ha investigado intensivamente, en ganado ovino y bovino, la variabilidad genética de caracteres reproductivos utilizando la búsqueda de variantes alélicas en genes candidatos que expliquen esta variabilidad y puedan ser empleados durante la selección. Actualmente en algunos casos su uso es una realidad (p.e. fecundidad, tamaño de camada en razas ovinas). Para otras características aún es requerida mayor investigación y validación de sus efectos putativos. En perspectiva, el futuro avizora mejores y más intensos logros con la disminución de los costos de tipificación y el mayor entendimiento en la interacción de los genes en caracteres complejos

    Agricultural waste as a sustainable source for nanoparticle synthesis and their antimicrobial properties for food preservation

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    Traditional agriculture from cropping to harvesting is contributing to climate change by increasing global greenhouse emissions. Circular economy approaches and biorefinery technologies based on the reuse, recycling, and remanufacturing might result in the valorization of wastes that consequently would avoid environmental pollution. Nanoparticles synthesis using bio-waste such as stems, leaves, seeds, pulp, stubble, and bagasse is considered a green approach with low energy consumption, and low-cost production. Characteristics of raw materials influence the final application of nanoparticles in edible coatings, and films. Therefore, the preparation of nanoparticles based on cellulose, pectin, metal (titanium oxide, silver, zinc oxide), or silica are considered organic, inorganic, or hybrid nanocomposites, are resulted in several benefits including shelf-life extension and broad-spectrum antimicrobial properties by its capacity to encapsulate active compounds that greatly improve food preservation. For considering agro-waste-based nanoparticles in food, challenges in homogenization and synthesis, yield, and toxicity are mainly described. Therefore, this review examines the employment of agro-industrial waste for the development of sustainable nanoparticles and their synthesis methods (top-down and bottom-up). Moreover, it discusses their incorporation and role in active edible coatings and films by highlighting their bioactive properties, mechanisms of action, and applications in food group preservation

    CREENCIAS ASOCIADAS AL CONSUMO DE SUSTANCIAS PSICOACTIVAS Y ABSTINENCIA EN PACIENTES CON DIAGNÓSTICO DUAL

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    Se investigó sobre el tipo de creencias relacionadas con el consumo de sustancias psicoactivas (SPA), y su relación con la abstinencia voluntaria, en pacientes farmacodependientes con diagnóstico dual (psicosis inducida por sustancias, trastorno afectivo bipolar y esquizofrenia). Participaron 90 pacientes del Programa de Rehabilitación de Farmacodependencias del Hospital Universitario ESE CARI de Barranquilla, Colombia. El instrumento utilizado fue el Cuestionario de Creencias Acerca del Abuso de Sustancias (Beck y cols., 1999). Los resultados muestran que las creencias más frecuentes son las de alivio, seguidas por las anticipadoras y las permisivas, con un ligero predominio de éstas en el grupo de Esquizofrenia. Aunque se observaron algunas asociaciones entre el tipo y el contenido de las creencias y el tipo de diagnóstico, sin embargo, no se encontró diferencia significativa al respecto del tipo de creencias entre los tres grupos diagnósticos. Tampoco se halló relación entre el tipo de creencia y el tiempo de abstinencia. ABSTRACTIt was investigated the type of beliefs related to psychoactive substance use (SPA) and its relation to the voluntary withdrawal in drug dependent patients with dual diagnosis (substance-induced psychosis, bipolar disorder and schizophrenia). 90 patients participated in the Drug Rehabilitation Program of the University Hospital ESE CARI Barranquilla, Colombia. The instrument used was the Questionnaire of Beliefs About Substance Abuse (Beck et al., 1999). The results indicate that beliefs most frequent are of relief, followed by anticipatory and permissive, with a slight predominance of these in the schizophrenia group. Although some associations were observed between the type and content of the beliefs and the type of diagnosis, however, there was no significant difference regarding the type of beliefs among the three diagnostic groups. Neither relation was found between the type of belief and the time of withdrawal

    Comparative study on the valorization of Sargassum from the Mexican Caribbean coast and Gulf of California as an ingredient on healthy diets for shrimp farming

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    Funding: This work received the financial support of the project GCRFNGR4/1388 "Algae bloom: waste resource for aquaculture and bioenergy industry in Mexico".Sargassum biomass is a potential ingredient for aquaculture formulations due to its high nutritional value and availability, as it contains a variety of essential nutrients including proteins, carbohydrates, lipids, vitamins, antioxidants, fiber, and minerals, which are essential for aquatic growing, development and health parameters including digestibility and immune response against diseases. Therefore, in this work, five experimental diets were formulated considering 2.5 % and 5 % levels of inclusion of Sargassum spp. from the Mexican Caribbean coasts (SC), and from the Gulf of California (SG), and one reference diet as a control. The characterization of the raw material and the proximal analysis of the five diets were evaluated according to standard reference methods. A 35-day feeding trial was conducted using juvenile Litopenaeus vannamei showed a shrimp survival rate of 97 ± 6 % (p > 0.05) on SC. Excellent weight gain (WG) performance of SC and SG diets at 2.5 % of inclusion resulted in >10 % WG compared to the control. The specific activity of amylase, lipase, trypsin, and chymotrypsin showed a significant increase by including Sargassum in diets, compared with the reference diet. Incorporating Sargassum at 2.5 % in feed formulations for shrimps showed a great opportunity to use it as an ingredient and improved production yields. The digestion and absorption parameters were represented by the enzymatic activity in which the diets based on Sargassum spp. from the Mexican Caribbean coast (SC) have resulted in the best performance.Publisher PDFPeer reviewe

    A mean square chain rule and its application in solving the random Chebyshev differential equation

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    [EN] In this paper a new version of the chain rule for calculat- ing the mean square derivative of a second-order stochastic process is proven. This random operational calculus rule is applied to construct a rigorous mean square solution of the random Chebyshev differential equation (r.C.d.e.) assuming mild moment hypotheses on the random variables that appear as coefficients and initial conditions of the cor- responding initial value problem. Such solution is represented through a mean square random power series. Moreover, reliable approximations for the mean and standard deviation functions to the solution stochastic process of the r.C.d.e. are given. Several examples, that illustrate the theoretical results, are included.This work was completed with the support of our TEX-pert.Cortés, J.; Villafuerte, L.; Burgos-Simon, C. (2017). A mean square chain rule and its application in solving the random Chebyshev differential equation. Mediterranean Journal of Mathematics. 14(1):14-35. https://doi.org/10.1007/s00009-017-0853-6S1435141Calbo, G., Cortés, J.C., Jódar, L., Villafuerte, L.: Analytic stochastic process solutions of second-order random differential equations. Appl. Math. Lett. 23(12), 1421–1424 (2010). doi: 10.1016/j.aml.2010.07.011El-Tawil, M.A., El-Sohaly, M.: Mean square numerical methods for initial value random differential equations. Open J. Discret. Math. 1(1), 164–171 (2011). doi: 10.4236/ojdm.2011.12009Khodabin, M., Maleknejad, K., Rostami, K., Nouri, M.: Numerical solution of stochastic differential equations by second order Runge Kutta methods. Math. Comp. Model. 59(9–10), 1910–1920 (2010). doi: 10.1016/j.mcm.2011.01.018Santos, L.T., Dorini, F.A., Cunha, M.C.C.: The probability density function to the random linear transport equation. Appl. Math. Comput. 216(5), 1524–1530 (2010). doi: 10.1016/j.amc.2010.03.001González Parra, G., Chen-Charpentier, B.M., Arenas, A.J.: Polynomial Chaos for random fractional order differential equations. Appl. Math. Comput. 226(1), 123–130 (2014). doi: 10.1016/j.amc.2013.10.51El-Beltagy, M.A., El-Tawil, M.A.: Toward a solution of a class of non-linear stochastic perturbed PDEs using automated WHEP algorithm. Appl. Math. Model. 37(12–13), 7174–7192 (2013). doi: 10.1016/j.apm.2013.01.038Nouri, K., Ranjbar, H.: Mean square convergence of the numerical solution of random differential equations. Mediterran. J. Math. 12(3), 1123–1140 (2015). doi: 10.1007/s00009-014-0452-8Villafuerte, L., Braumann, C.A., Cortés, J.C., Jódar, L.: Random differential operational calculus: theory and applications. Comp. Math. Appl. 59(1), 115–125 (2010). doi: 10.1016/j.camwa.2009.08.061Øksendal, B.: Stochastic differential equations: an introduction with applications, 6th edn. Springer, Berlin (2007)Soong, T.T.: Random differential equations in science and engineering. Academic Press, New York (1973)Wong, B., Hajek, B.: Stochastic processes in engineering systems. Springer Verlag, New York (1985)Arnold, L.: Stochastic differential equations. Theory and applications. John Wiley, New York (1974)Cortés, J.C., Jódar, L., Camacho, J., Villafuerte, L.: Random Airy type differential equations: mean square exact and numerical solutions. Comput. Math. Appl. 60(5), 1237–1244 (2010). doi: 10.1016/j.camwa.2010.05.046Calbo, G., Cortés, J.C., Jódar, L.: Random Hermite differential equations: mean square power series solutions and statistical properties. Appl. Math. Comp. 218(7), 3654–3666 (2011). doi: 10.1016/j.amc.2011.09.008Calbo, G., Cortés, J.C., Jódar, L., Villafuerte, L.: Solving the random Legendre differential equation: Mean square power series solution and its statistical functions. Comp. Math. Appl. 61(9), 2782–2792 (2010). doi: 10.1016/j.camwa.2011.03.045Cortés, J.C., Jódar, L., Company, R., Villafuerte, L.: Laguerre random polynomials: definition, differential and statistical properties. Utilit. Math. 98, 283–293 (2015)Cortés, J.C., Jódar, L., Villafuerte, L.: Mean square solution of Bessel differential equation with uncertainties. J. Comp. Appl. Math. 309, 383–395 (2017). doi: 10.1016/j.cam.2016.01.034Golmankhaneh, A.K., Porghoveh, N.A., Baleanu, D.: Mean square solutions of second-order random differential equations by using homotopy analysis method. Romanian Reports Physics 65(2), 1237–1244 (2013)Khalaf, S.L.: Mean square solutions of second-order random differential equations by using homotopy perturbation method. Int. Math. Forum 6(48), 2361–2370 (2011)Khudair, A.R., Ameen, A.A., Khalaf, S.L.: Mean square solutions of second-order random differential equations by using Adomian decomposition method. Appl. Math. Sci. 5(49), 2521–2535 (2011)Agarwal, R.P., O’Regan, D.: Ordinary and partial differential equations. Springer, New York (2009

    Modal Series Expansions for Plane Gravitational Waves

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    [EN] Propagation of gravitational disturbances at the speed of light is one of the key predictions of the General Theory of Relativity. This result is now backed indirectly by the observations of the behavior of the ephemeris of binary pulsar systems. These new results have increased the interest in the mathematical theory of gravitational waves in the last decades, and severalmathematical approaches have been developed for a better understanding of the solutions. In this paper we develop a modal series expansion technique in which solutions can be built for plane waves from a seed integrable function. The convergence of these series is proven by the Raabe-Duhamel criteria, and we show that these solutions are characterized by a well-defined and finite curvature tensor and also a finite energy content.Acedo Rodríguez, L. (2016). Modal Series Expansions for Plane Gravitational Waves. Gravitation and Cosmology. 22(3):251-257. doi:10.1134/S0202289316030026S251257223A. Einstein and N. Rosen, Journal of the Franklin Institute 223, 43–54 (1937).N. Rosen, Gen. Rel. Grav. 10, 351–364 (1979).C. Sivaram, Bull. Astr. Soc. India 23, 77–83 (1995).J. M. Weisberg, D. J. Nice, and J. H. Taylor, Astroph. J. 722, 1030–1034(2010); arXiv: 1011.0718.B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration), Phys. Rev. Lett. 116, 061102 (2016).J. B. Griffiths, Colliding waves in general relativity (Clarendon, Oxford, 1991).S. Chandrasekhar, The mathematical theory of black holes (Clarendon, Oxford, 1983).D. Bini, V. Ferrari and J. Ibañez, Nuovo Cim. B 103, 29–44 (1989).L. Acedo, G. González-Parra, and A. J. Arenas, Nonlinear Analysis: Real World Applications 11, 1819–1825 (2010).L. Acedo, G. González-Parra, and A. J. Arenas, Physica A 389, 1151–1157 (2010).G. González-Parra, L. Acedo, and A. J. Arenas, Numerical Algorithms, published online 2013. doi 10.1007/s11075-013-9776-xW. Rindler, Relativity: Special, General and Cosmological, 2nd ed. (Oxford Univ., New York, 2006).G. Arfken, Mathematical Methods for Physicists, 3rd. ed. (Academic, Orlando, Florida, 1985).L. D. Landau and E. M. Lifshitz, The Classical Theory of Fields, 3rd ed. (Pergamon, New York, 1971).O. Costin, “Topological construction of transseries and introduction to generalized Borel summability,” in Analyzable Functions and Applications, Ed. by O. Costin, M. D. Kruskal, and A. Macintyre, Contemp. Math. 373 (Providence, RI, USA: Am. Math. Soc., 2005); arXiv: math/0608309.S. R. Coleman, Phys. Lett. B 70, 59–60 (1977).W. B. Campbell and T. A. Morgan, Phys. Lett. B 84, 87–88 (1979).A. S. Rabinowitch, Int. J. Adv. Math. Sciences 1 (3), 109–121 (2013).A. Feinstein and J. Ibañez, Phys. Rev. D 39 (2), 470–473 (1989)

    HDAC7 Is a Repressor of Myeloid Genes Whose Downregulation Is Required for Transdifferentiation of Pre-B Cells into Macrophages

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    B lymphopoiesis is the result of several cell-commitment, lineage-choice, and differentiation processes. Every differentiation step is characterized by the activation of a new, lineage-specific, genetic program and the extinction of the previous one. To date, the central role of specific transcription factors in positively regulating these distinct differentiation processes to acquire a B cell-specific genetic program is well established. However, the existence of specific transcriptional repressors responsible for the silencing of lineage inappropriate genes remains elusive. Here we addressed the molecular mechanism behind repression of non-lymphoid genes in B cells. We report that the histone deacetylase HDAC7 was highly expressed in pre-B cells but dramatically down-regulated during cellular lineage conversion to macrophages. Microarray analysis demonstrated that HDAC7 re-expression interfered with the acquisition of the gene transcriptional program characteristic of macrophages during cell transdifferentiation; the presence of HDAC7 blocked the induction of key genes for macrophage function, such as immune, inflammatory, and defense response, cellular response to infections, positive regulation of cytokines production, and phagocytosis. Moreover, re-introduction of HDAC7 suppressed crucial functions of macrophages, such as the ability to phagocytose bacteria and to respond to endotoxin by expressing major pro-inflammatory cytokines. To gain insight into the molecular mechanisms mediating HDAC7 repression in pre-B cells, we undertook co-immunoprecipitation and chromatin immunoprecipitation experimental approaches. We found that HDAC7 specifically interacted with the transcription factor MEF2C in pre-B cells and was recruited to MEF2 binding sites located at the promoters of genes critical for macrophage function. Thus, in B cells HDAC7 is a transcriptional repressor of undesirable genes. Our findings uncover a novel role for HDAC7 in maintaining the identity of a particular cell type by silencing lineage-inappropriate genes

    Análise do genoma completo para identificar variações associadas à circunferência escrotal em bovinos Charolês

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    The scrotal circumference is one of the main characteristics related to fertility of the bovine male and female. Its study through genetic and genomic tools would help to the discovery of favorable variation and genetic architecture to promote its selection. The aim of this work was to carry out a genome- wide association study using a large microarray of SNPs, to identify variations and candidate genes associated with the studied trait, for which information from 141 Charolais bulls was used. Four markers found, rs110416965, rs110130953, rs43423602 and rs29003417, showed significant association at the genome level. Three of them are found within candidate genes (RBFOX2, TTF2 and CXCL2). This information contributes to the understanding of the genetic architecture of this trait.  La circunferencia escrotal es una de las características realcionadas a la fertilidad del macho y la hembra bovina. Su estudio a través de herramientas genéticas y genómicas ayudaría al descubrimiento de variación favorable en su arquitectura genética para fomentar su selección. El propósito del presente trabajo fue realizar un estudio de genoma completo mediante un microarreglo de SNPs, para identificar variaciones y genes candidatos asociados a la característica, para lo que se utilizó la información de 141 toros de la raza Charolais. Cuatro marcadores encontrados, rs110416965, rs110130953, rs43423602 y rs29003417, mostraron asociación significativa a nivel de genoma. Tres de ellos se encuentran dentro de genes candidatos (RBFOX2, TTF2 y CXCL2) para ser estudiados más especificamente. Esta información contribuye al entendiemiento de la arquitectura genética de esta característicaA circunferência escrotal é uma das características relacionadas à fertilidade do macho e da fêmea bovina. Seu estudo por meio de ferramentas genéticas e genômicas auxiliaria na descoberta de variação favorável em sua arquitetura genética para promover sua seleção. O objetivo deste trabalho foi realizar um estudo do genoma completo usando um microarray de SNPs, para identificar variações e genes candidatos associados à característica, para o qual foram utilizadas informações de 141 touros Charolês. Quatro marcadores encontrados, rs110416965, rs110130953, rs43423602 e rs29003417, mostraram associação significativa no nível do genoma. Três deles foram encontrados em genes candidatos (RBFOX2, TTF2 e CXCL2) a serem estudados mais especificamente. Essas informações contribuem para o entendimento da arquitetura genética dessa característica
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