Orthosymplectic Jordan superalgebras and the Wedderburn principal theorem (WPT)

An analogue of the Wedderbur principal theorem (WPT) is considered for finite dimensional Jordan superalgebras A with solvable radical N, such that N^2=0 and A/N is isomorphic to Josp_n|2m(F), where F is an algebraicallly closed field of characteristic zero. Let's we prove that the WPT is valid under some restrictions over the irreducible Josp_n|2m(F)-bimodules contained in N, and it is shown with counter-examples that these restrictions can not be weakened.Comment: 13 page

A 3-3-1 model with low scale seesaw mechanisms

We construct a viable 3-3-1 model with two $SU(3)_L$ scalar triplets, extended fermion and scalar spectrum, based on the $T^{\prime}$ family symmetry and other auxiliary cyclic symmetries, whose spontaneous breaking yields the observed pattern of SM fermion mass spectrum and fermionic mixing parameters. In our model the SM quarks lighter than the top quark, get their masses from a low scale Universal seesaw mechanism, the SM charged lepton masses are produced by a Froggatt-Nielsen mechanism and the small light active neutrino masses are generated from an inverse seesaw mechanism. The model is consistent with the low energy SM fermion flavor data and successfully accommodates the current Higgs diphoton decay rate and predicts charged lepton flavor violating decays within the reach of the forthcoming experiments.Comment: 24 pages, 4 figures. Published versio

Critical behavior of ferromagnetic pure and random diluted nanoparticles with competing interactions: variational and Monte Carlo approaches

The magnetic properties and critical behavior of both ferromagnetic pure and metallic nanoparticles having concurrently atomic disorder, dilution and competing interactions, are studied in the framework of an Ising model. We have used both the free energy variational principle based on the Bogoliubov inequality and Monte Carlo simulation. As a case of study for random diluted nanoparticles we have considered the Fe$_{0.5}$Mn$_{0.1}$Al$_{0.4}$ alloy characterized for exhibiting, under bulk conditions, low temperature reentrant spin glass (RSG) behavior and for which experimental and simulation results are available. Our results allow concluding that the variational model is successful in reproducing features of the particle size dependence of the Curie temperature for both pure and random diluted particles. In this last case, low temperature magnetization reduction was consistent with the same type of RSG behavior observed in bulk in accordance with the Almeida-Thouless line at low fields and a linear dependence of the freezing temperature with the reciprocal of the particle diameter was also obtained. Computation of the correlation length critical exponent yielded the values $\nu=0.926\pm 0.004$ via Bogoliubov and$\nu =0.71\pm 0.04$ via Monte Carlo. This fact indicates that even though thermodynamical models can be indeed used in the study of nanostructures and they can reproduce experimental features, special attention must be paid regarding critical behavior. From both approaches, differences in the $\nu$ exponent with respect to the pure Ising model agree with Harris and Fisher arguments.Comment: 11 pages, 11 figures. Submitted to Phys. Rev.

Electricity contract price prediction using genetic programming with functional blocks

The prediction of the prices of the contracts in non-regulated electricenergy markets is the key for the market agents to make strategic business and operational decisions. The average prices of the contracts sold in the Colombian electric energy market are predicted in this study by means of a modified genetic programming algorithm. The developed model is capable of capturing the intrinsic dynamics of the prices and the price predictions for the upcoming months with a more accurate precision than the ARIMA and DAN2 models for prediction horizons of 12 and 14 months, as they have been reported in the literature.La predicción de los precios de los contratos en los mercados energéticos desregularizados es la clave para la toma de decisiones estratégicas de negocio y operativas por los agentes del mercado. En este trabajo se predicen los precios promedio de los contratos vendidos en el mercado eléctrico colombiano, utilizando un algoritmo de programación genética modificado. El modelo desarrollado es capaz de capturar la dinámica intrínseca de los precios y las predicciones de precios para los próximos meses con mayor precisión que los modelos ARIMA y DAN2 para horizontes de predicción de 12 y 24 meses, reportados en la literatura

Prácticas de bioseguridad en lecherías comerciales de la Zona Central de Chile

Biosecurity is defined as the set of measures designed to reduce the entry of pathogens to the herd as well as to avoid or reduce their dissemination within the herd. Biosecurity status is becoming increasingly important, since it influences herd health and product quality. However, biosecurity status in dairy farms in Chile is not known. The aim of the present study was to describe the main biosecurity practices carried out in commercial dairies of the Central Zone of Chile. To carry out this, a survey was designed and subsequently applied to 33 dairy farms located in the regions of Valparaiso, O`Higgins and Metropolitan. This activity was complemented with a visit and inspection of the dairy. Regarding to the arrival of cattle from other farms, in 13 dairies (39.4 %) new cattle were brought into the herd during the last 2 years. Heifers were the class most frequently brought. In 6 of these dairies (46.2%), quarantine to the incoming animals was carried out. In relation to the people's traffic, in 8 operations (24.2 %) there was some kind of signposting in the entry of the facilities and only in one (3 %), visitors had to clean and disinfect its footwear before entering to the facilities. Regarding vehicle traffic, only two operations (6 %) keep a process of disinfection for the wheels of the vehicles entering to the facilities. In all the dairies surveyed there were other animal species, which, in the majority of the cases, had direct contact with the bovines or with its sources of water or food. The species observed with the highest frequencies were: cats (90.9%), dogs (72.7%), horses (60.6%), and poultry (36.4%). In relation to the food management, in 17 cases (51.5 %) the remaining food of the adult cattle was used in the ration of another group of females, being the most frequent destination the rations of dry cows and weaned calves. It is concluded that in general the biosecurity status of the dairies surveyed is insufficient. The most deficient areas regarding biosecurity practices are people's entrance and control, and the contact of cattle with other domestic species. However, there is a low degree of inclusion of foreign animals into the herd, since it is widely acknowledged that keeping a closed herd is an effective way to prevent the access of pathogens to the farm.    La bioseguridad se define como el conjunto de medidas tendientes a reducir la entrada de patógenos a la explotación animal así como a evitar o disminuir su diseminación dentro del predio. Hoy en día, la situación de bioseguridad adquiere gran importancia, ya que influye en la salud del rebaño y la calidad del producto final. El presente estudio tuvo por objetivo describir las principales prácticas de bioseguridad que se aplican en lecherías comerciales de la Zona Central de Chile. Para esto, se elaboró una encuesta que se realizó en 33 predios de las regiones de Valparaiso, O´Higgins y Metropolitana. Esta actividad se complementó con una visita e inspección del plantel. En relación al ingreso de bovinos desde otros predios, en 13 lecherías (39,4%) se incorporó algún tipo de ganado nuevo a su rebaño, durante los últimos 2 años. El tipo de ganado más frecuente de ingresar fueron las vaquillas. De estas lecherías, en 6 de ellas (46,2%) se realizó cuarentena de los animales ingresados. En relación al ingreso de personas, en 8 predios (24,2%) había algún tipo de señalización en la entrada del predio y sólo en una (3%) los visitantes debían limpiar y desinfectar su calzado antes de ingresar a las instalaciones. Para el ingreso de vehículos, sólo dos planteles (6%) mantenían un rodiluvio o proceso de desinfección para las ruedas de los vehículos que ingresaban al plantel. En todas las lecherías encuestadas existían otras especies de animales, donde la mayoría de ellas, tenían contacto directo con los bovinos o con sus fuentes de agua o de alimento. Las especies observadas con mayor frecuencia fueron: gatos (90,9%), perros (72,7%), caballos (60,6%) y aves de corral (36,4%). Respecto al manejo alimentario, en 17 casos (51,5%), el alimento sobrante de los animales adultos era utilizado en la ración de otro grupo de hembras, siendo su destino más frecuente la ración de las vacas secas y las terneras en recría. Se concluye que en general la situación de bioseguridad en las lecherías encuestadas es insuficiente. Las áreas más deficientes en prácticas de bioseguridad fueron el ingreso y control de personas externas al predio y el contacto de los bovinos con otras especies domésticas. Sin embargo, existe una baja incorporación de animales desde otros predios, ya que se reconoce que mantener un rebaño cerrado es una medida eficaz para prevenir el ingreso de patógenos al plantel.  

Affine term structure models: forecasting the Colombian yield curve

Modelar de forma superior la curva de rendimientos es útil para valoración de activos, planeación financiera y administración de riesgos. En este artículo se estiman cinco modelos afines de la estructura a plazos colombiana usando datos diarios. Se encuentra que un modelo de tres factores tiene un desempeño superior a los demás modelos para pronósticos intra-muestrales y para pronósticos (fuera de la muestra) con horizontes de uno y cinco días. Los factores del modelo se asemejan a sus contrapartes empíricas del nivel, la pendiente y la curvatura de la curva de rendimientos colombiana.Superior modeling of the yield curve is useful for asset pricing, financial planning, and risk management. In this article, we estimate five affine term structure models using daily Colombian data. We find that a three-factor model outperforms the other models in one and five days ahead forecasts. The model’s factors closely mimic empirical proxies for the level, the slope, and the curvature of the Colombian yield curve

Effects of Liposomes Contained in Thermosensitive Hydrogels as Biomaterials Useful in Neural Tissue Engineering

Indexación: Scopus.Advances in the generation of suitable thermosensitive hydrogels for the delivery of cells in neural tissue engineering demonstrate a delicate relationship between physical properties and capabilities to promote cell proliferation and differentiation. To improve the properties of these materials, it is possible to add liposomes for the controlled release of bioactive elements, which in turn can affect the physical and biological properties of the hydrogels. In the present investigation, different hydrogels based on Pluronic F127 have been formulated with the incorporation of chitosan and two types of liposomes of two different sizes. The rheological and thermal properties and their relation with the neurite proliferation and growth of the PC12 cell line were evaluated. Our results show that the incorporation of liposomes modifies the properties of the hydrogels dependent on the concentration of chitosan and the lipid type in the liposomes, which directly affect the capabilities of the hydrogels to promote the viability and differentiation of PC12 cells. © 2017 by the authors.http://www.mdpi.com/1996-1944/10/10/112

UNA MIRADA A LA COMPETITIVIDAD DESDE LOS DISTRITOS INDUSTRIALES

El presente articulo se presenta como un subproducto de la investigación que lleva como titulo Modelo de competitividad para las empresas del Valle de Aburrá mediante la conformación de los distritos industriales" financiada por la Universidad de San Buenaventura seccional Medellín y la Empresa privada Skynet Medellín S.A. El artículo pretende demostrar la importancia que representa hoy en día para las PYMES de los países de América Latina y en especial Colombia, la conformación de estructuras productivas fuertes mediante la creación de aglomeraciones y distritos industriales. Los tratados comerciales y la integración económica entre países requieren que este tipo de esquemas de asociatividad no sea una alternativa, sino un hecho real y concreto si se quiere evitar la desaparición trágica de miles de pequeñas y medianas empresas en Colombia. La integración comercial y el Tratado de Libre Comercio con Estados Unidos constituyen una gran oportunidad no sólo para lograr mejores desempeños de tipo macroeconómico en el país, sino también para un mejor aprovechamiento de los nuevos escenarios comerciales por parte las empresas. Se hace necesario entonces el diseño y desarrollo de estrategias claras para la producción, como lo son los clusters, las cadenas de valor agregado y los distritos industriales. Estas estrategias se convierten en una gran solución para la permanencia de este tipo de empresas en Colombia."Competitiveness, industrial district, agglomerations, chain of values, clusters, productivity, technology, specific sector. / Competitividad, distrito industrial, aglomeraciones, cadena de valor, clusters de producción, productividad, tecnología, sector específico.

The growth factor parametrization versus numerical solutions in flat and non-flat dark energy models

In the present investigation we use observational data of $f \sigma_ {8}$ to determine observational constraints in the plane $(\Omega_{m0},\sigma_{8})$ using two different methods: the growth factor parametrization and the numerical solutions method for density contrast, $\delta_{m}$. We verified the correspondence between both methods for three models of accelerated expansion: the $\Lambda CDM$ model, the $w_{0}w_{a} CDM$ model and the running cosmological constant $RCC$ model. In all case we consider also curvature as free parameter. The study of this correspondence is important because the growth factor parametrization method is frequently used to discriminate between competitive models. Our results we allow us to determine that there is a good correspondence between the observational constrains using both methods. We also test the power of the $f\sigma_ {8}$ data to constraints the curvature parameter within the $\Lambda CDM$ model. For this we use a non-parametric reconstruction using Gaussian processes. Our results show that the $f\sigma_ {8}$ data with the current precision level does not allow to distinguish between a flat and non-flat universe