Characterization of Progenitor Cells during Canine Retinal Development

We identify the presence of progenitor cells during retinal development in the dog, as this species represents a natural model for studying several breed-specific degenerative retinal disorders. Antibodies to detected progenitor cells (Pax6, C-kit, and nestin) and ganglion cells (BDNF, Brn3a, and Thy1) were used in combination with H3 for the purpose of identifying proliferating cells. Pax6, nestin, C-kit, and H3 were localized mainly in the neuroblastic layer of the retina during the embryonic stage. During the fetal stage, proteins were expressed in the inner neuroblastic layer (INL) as well as in the outer neuroblastic layer; BDNF, Thy1, and Brn3a were also expressed in the INL. During the neonatal stage only C-kit was not expressed. Proliferating cells were present in both undifferentiated and differentiated retina. These results suggest that, during canine retinogenesis, progenitor cells are distributed along the retina and some of these cells remain as progenitor cells of the ganglion cells during the first postnatal days

Challenges for the Adoption of Model-Driven Web Engineering Approaches in Industry

Model-driven web engineering approaches have become an attractive research and technology solution for Web application development. However, after 20 years of development, they have attracted little attention from the Industry due to the mismatch between technical versus research requirements. In this joint work between academia and industry, the authors present the current problems of using these approaches in scale and provide guidelines to convert them into viable industry solutions.Ministerio de ciencia e Innovación TIN2016-76956-C3-2-RMinisterio de Economía y Competitividad TIN2015-71938-RED

Linguistic skills of children from a low socioeconomic level at the beginning of elementary education

The purpose of this study was to assess the linguistic skills of children from a low socioeconomic background who were beginning their elementary education. A total of 262 first-grade students with an average age of 5.7 years old and who were enrolled in 8 groups of public schools from Mexico State, participated in this project. The instrument used was the Precurrent Skills for Reading Assessment (PSRA) by Vega (1991), and was administered individually to each student at the beginning of the 2004-2005 school year. The statistical analysis using SPSS showed a mean score of 77 (SD=14), which corresponds to 57% of the total PSRA score. These results may indicate that first grade students have an unsatisfactory level of linguistic behaviour. Slight differences in the students’ performances were observed. A slightly better performance was shown by those first grade students who were 6 years old at the beginning of the school year and who had previously received pre-school education. The implications of the poor linguistic level shown by the participants are discussed, and some alternatives based on the behavioural research, are proposed.El objetivo de este estudio fue evaluar las habilidades linguísticas con que ingresan a la educación básica primaria alumnos de estrato socioeconómico bajo. Participaron 262 alumnos de primer grado, inscritos en ocho grupos de escuelas públicas del Estado de México, con una media de 5.7 años de edad. Se aplicó individualmente a cada alumno el Instrumento para Evaluar Habilidades precurrentes para la lectura (EPLE), de Vega (1991), al inicio del ciclo escolar 2004-2005. El análisis estadístico con el programa SPSS arrojó como resultado un puntaje promedio de 77 (DS=14). Que corresponde al 57% de la clasicficación total del eple, lo que puede indicar que los alumnos ingresaron al primer grado de primaria con un nivel insatisfactorio de conductas linguísticas. Se observan ligeras diferencias en las ejecuciones de los alumnos, a favor de quienes ingresaron con seis años de edad y con mayor número de años cursados en preescolar. Se discuten las implicaciones del bajo nivel linguístico mostrado por los participantes y se proponen alternativas basadas en la investigación psiclógica conductual

Evaluación de tres alternativas de fertiriego en el establecimiento del cultivo de plátano (musa paradisiaca/harton cv) en el Yopal, Casanare

Currently, in agriculture it is necessary to implement methods of rational handling of water resource. Plantain cultivation required a high content of water and fertilizer. Fertigation is an alternative to supplying hydric requirements and at the same time fertilizing the plant. The region of Colombia’s eastern plains is characterized by clay loam soils, little permeability and slow infiltration velocity. This makes the arrangement of fertilizers appear on the surface of the land thus making it difficult to move to the root zone. In the present research, three fertigation alternatives (T1: subterranean, T2: drip, T3: drench) were evaluated at the establishment stage. An experimental batch composed of 30 experimental units was established for each treatment. The Readily Available Water RAW was obtained taking into account the Permanent Wilt Point (PMP), Field Capacity (CC), Root Depth (RD) and apparent density (DA). The requirement of fertilization was calculated from soil analysis. The response variables were the number of leaves, diameter of the stem and height and weight of the plant. For the ANOVA, a completely randomized design-CRD was used and data were analyzed by using an INFOSTAT LSD Fisher test with a p value of 0.05. Significant differences between the treatments were found, where the treatment of subterranean fertigation evidenced bigger values in relation to the follow-up variables. In this work, one observed that the alternative of subterranean fertigation could be an affordable solution for an efficient handling of water and fertilization in the cultivation of plantains due to the alternative arrangements of local water and nutrients for the plant.En la actualidad es necesario implementar en la agricultura métodos de manejo racional del recurso hídrico. El cultivo de plátano requiere altos contenidos de agua y fertilizante. El fertiriego es una alternativa para suplir requerimientos hídricos y a la vez fertilizar la planta. La región de los llanos orientales se caracteriza por suelos franco-arcillosos, poco permeables y de velocidad de infiltración lenta. Lo que hace que la disposición de fertilizantes se localice en superficie del terreno, dificultando su paso hacia la zona radicular. En la presente investigación se evaluó en etapa de establecimiento tres alternativas de fertiriego (T1: subterráneo, T2: goteo, T3: drench). Se estableció un lote experimental compuesto por 30 unidades experimentales para cada tratamiento. La Lámina Rápidamente Aprovechable (LARA), se estableció teniendo en cuenta el Punto de Marchitez Permanente (PMP), la Capacidad de Campo (CC), la Profundidad Radicular (PR) y la densidad aparente (DA). Los requerimientos de fertilización se estimaron a partir de análisis de suelos. Las variables de respuesta fueron el número de hojas, diámetro del tallo, altura de la planta y peso de la planta. Para el ANOVA se utilizó un DCA y los datos fueron analizados en INFOSTAT mediante una prueba LSD Fisher con un valor p valor de 0.05. Se encontraron diferencias significativas entre los tratamientos, en donde el tratamiento de fertiriego subterráneo mostró mayores valores respecto a las variables de seguimiento. En este trabajo se encontró que la alternativa de fertiriego subterráneo podría ser una solución viable para un manejo eficiente del agua y fertilización en el cultivo de plátano, posiblemente a que esta alternativa dispone de manera local el agua y los nutrientes para la planta

Presupuesto operacional y gestión gerencial. Una mirada en la agroindustria de Sogamoso, Boyacá.

Agribusiness is a very important subsector in the development of the agricultural sector in Colombia, Sogamoso, Boyacá, therefore this study aimed the objective of this research was to know the agro-industrial management management through the use of the operational budget. The methodology has a deductive-descriptive orientation, for this, information about the agro-industry was collected, a survey was applied to the universe of agro-industrial companies in Sogamoso (17 companies) and a company was shown for the budget analysis. As results, it was found that most of the agroindustrial companies do not apply a budgeting technique in managerial management, with respect to the company that applied the operational budget, it was found that it is necessary to analyze its costing structure and generate greater diversification of products. Finally, it is concluded that there is a need for greater awareness about the use of budgets; Regarding the company in which the implementation was carried out, it is recommended that the strategic approach of managerial management be based on the budget analysis.La agroindustria es un subsector muy importante en el desarrollo del sector agropecuario de Colombia, Boyacá y Sogamoso, por ello este estudio tuvo como objetivo conocer la gestión gerencial agroindustrial mediante el uso del presupuesto operacional. La metodología tiene una orientación deductiva-descriptiva, para ello se recopilo información acerca de la agroindustria, se aplicó encuesta al universo de empresas agroindustriales de Sogamoso (17 empresas) y se muestro una empresa para el análisis presupuestal. Como resultados se encontró que la mayor parte de las empresas agroindustriales no aplica una técnica presupuestal en la gestión gerencial, respecto a la empresa que se aplicó el presupuesto operacional se encontró que se requiere analizar su estructura de costeo y generar mayor diversificación de productos. Finalmente se concluye que es necesario que exista una mayor concientización acerca del uso de los presupuestos; en cuanto a la empresa en que se realizó la implementación se recomienda que el enfoque estratégico de la gestión gerencial se fundamente en el análisis presupuestal

Presupuesto operacional y gestión gerencial. Una mirada en la agroindustria de Sogamoso, Boyacá.

Agribusiness is a very important subsector in the development of the agricultural sector in Colombia, Sogamoso, Boyacá, therefore this study aimed the objective of this research was to know the agro-industrial management management through the use of the operational budget. The methodology has a deductive-descriptive orientation, for this, information about the agro-industry was collected, a survey was applied to the universe of agro-industrial companies in Sogamoso (17 companies) and a company was shown for the budget analysis. As results, it was found that most of the agroindustrial companies do not apply a budgeting technique in managerial management, with respect to the company that applied the operational budget, it was found that it is necessary to analyze its costing structure and generate greater diversification of products. Finally, it is concluded that there is a need for greater awareness about the use of budgets; Regarding the company in which the implementation was carried out, it is recommended that the strategic approach of managerial management be based on the budget analysis.La agroindustria es un subsector muy importante en el desarrollo del sector agropecuario de Colombia, Boyacá y Sogamoso, por ello este estudio tuvo como objetivo conocer la gestión gerencial agroindustrial mediante el uso del presupuesto operacional. La metodología tiene una orientación deductiva-descriptiva, para ello se recopilo información acerca de la agroindustria, se aplicó encuesta al universo de empresas agroindustriales de Sogamoso (17 empresas) y se muestro una empresa para el análisis presupuestal. Como resultados se encontró que la mayor parte de las empresas agroindustriales no aplica una técnica presupuestal en la gestión gerencial, respecto a la empresa que se aplicó el presupuesto operacional se encontró que se requiere analizar su estructura de costeo y generar mayor diversificación de productos. Finalmente se concluye que es necesario que exista una mayor concientización acerca del uso de los presupuestos; en cuanto a la empresa en que se realizó la implementación se recomienda que el enfoque estratégico de la gestión gerencial se fundamente en el análisis presupuestal

Experimental Air Impingement Crossflow Comparison and Theoretical Application to Photovoltaic Efficiency Improvement

The photovoltaic cell temperature is a key factor in solar energy harvesting. Solar radiation raises temperature on the cell, lowering its peak efficiency. Air jet impingement is a high heat transfer rate system and has been previously used to cool the back surface of photovoltaic modules and cells. In this work, an experimental comparison of the cooling performance of two different air jet impingement crossflow schemes was performed. Crossflow is defined as the air mass interacting with a certain jet modifying its movement. This leads to a change in its heat exchange capabilities and is related with the inlet-outlet arrangement of the fluid. In this work, zero and minimum crossflow schemes were compared. The main contribution of this work considered the consumption of the flow supplying devices to determine the most suitable system. The best configuration increased the net power output of the cell by 6.60%. These results show that air impingement cooling can play a role in increasing photovoltaic profitability. In terms of uniformity, on small impingement plates with a low number of nozzles, the advantages expected from the zero crossflow configuration did not stand out.This work was funded by the Regional Development Agency of the Basque Country (SPRI) [grant number KK-2018/00109]

Evolución de la teoría económica de las finanzas: una breve revisión

Para todos los profesionales interesados en el área de las finanzas, sean o no economistas, es muy importante lograr un detallado conocimiento sobre las técnicas y herramientas que se pueden emplear para valorar el riesgo y el rendimiento de aquellos activos en los que se desea invertir. Este artículo presenta una breve y clara descripción de los distintos modelos que se han desarrollado desde el año 1952, año en el que Harry Markowitz presentó su teoría de portafolios, hasta nuestros días. En otros términos este trabajo presenta la evolución o estado del arte de la Teoría económica de las finanzas.Teoría Económica de las Finanzas, Modelo CAPM, Mode- lo APT, Modelo OPM, Riesgo, Valoración de Activos