Proposal of technical and environmental viability for the use of green waste generated by the activity of cutting grass in the D.C. Capital District

El presente proyecto de investigación se inserta en los modelos de sostenibilidad de la ciudad, con respecto al cambio climático y maximización de sus recursos ecológicos; en la medida en que plantea la posibilidad de disminuir el impacto ambiental de los desechos verdes; al proponer el reciclaje de los residuos verdes resultado del corte del césped de la ciudad de Bogotá, utilizándolos como medios que contribuyan a la recuperación de los suelos degradados de la urbe; además de convertirlos en abono de las plantas y vegetales ornamentales de las zonas verdes, contribuyendo de esta manera a reducir los costos de su mantenimiento.The present research project is inserted in the models of sustainability of the city, with regard to climate change and maximizing their ecological resources; in so far as it raises the possibility of reducing the environmental impact of waste green; to propose the recycling of waste green a result of cutting the turf of the city of Bogota, using them as a means to contribute to the recovery of degraded soils of the city; in addition of composting plants and ornamental plants of green areas, contributing in this way to reduce the cost of its maintenance

Gastric perforation and phlegmon formation by foreign body ingestion

This is a case report of foreign body ingestion in a suicide attempt resulting in gastric perforation and phlegmon formation during a subsequent 6 month period that eventually required surgical intervention. The patient had a prolonged course because she did not report a history of foreign body ingestion and the initial evaluating physicians had no suspicion about possible foreign body ingestion and may have missed important findings on physical examination. Gastric perforation by a foreign object may have a slow course rather than presenting acute abdomen. The realization of a proper physical examination in the emergency department is key to an accurate diagnosis.https://scienti.minciencias.gov.co/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0000525715Revista Nacional - Indexad

Qualitative Assessment of User Acceptance within Action Design Research and Action Research: Two Case Studies

Nowadays, there are several models to evaluate technological acceptance of software developed through Action Design Research and Action Research. These models rely on quantitative techniques to study user behavioural intentions and thus predict the use of a technology. This paper presents our experiences in using qualitative methods to assess such acceptance in the development of specialized tools for Strategic Scanning. Our study suggests that qualitative methods can be an alternative to evaluate technology acceptance in situations where the number of users is small or where there are requirements for continuous improvement

Petróleo, IED y crecimiento económico: evidencia para Colombia 1980 – 2018

Trabajo de investigaciónEl precio del Petróleo tiene un comportamiento volátil en el mercado de valores y representa una referencia importante para el mercado bursátil. La producción de barriles, el precio del dólar y el mercado internacional de los barriles son los principales factores que impactan el precio del Petróleo. Este documento estima el efecto de largo plazo que tiene el precio del petróleo sobre el PIB y sobre la inversión extranjera directa, mediante un modelo econométrico VEC se verifica la relación entre el precio del petróleo, el Producto Interno Bruto (PIB) y la Inversión Extranjera Directa (IED) en Colombia para el periodo 1980 al 2018. Los resultados muestran que los aumentos en el precio del petróleo tienen un efecto negativo sobre el crecimiento económico.).INTRODUCCIÓN PLANTEAMIENTO DEL PROBLEMA REVISIÓN DE LITERATURA EVIDENCIA EMPÍRICA RESULTADOS CONCLUSIONES REFERENCIASPregradoEconomist

Sobre algunos mitos y realidades de la ganadería bovina

The rise of cable television, the Internet, and the importance of social networks have contributed to the widespread dissemination of messages that are seriously affecting the agri-food system, mainly due to the dissemination of inaccuracies that create panic in some regions about the consumption of animal origin products. The collective imaginary is loaded with beliefs that, in most cases, do not have enough foundations and, in many others, it has a political sense or intentions without technical and scientific support. The aim of this document is to present evidence to support some myths related to bovine production systems to favor the debate on the consumption of beef, which is gaining strength around the world.El auge de la televisión por cable, el advenimiento de Internet y la expansión de las redes sociales han contribuido a que se difundan profusamente mensajes que están afectando en gran manera el sistema agroalimentario al difundir imprecisiones y generar, en algunas esferas, pánico hacia el consumo de productos de origen animal. El imaginario colectivo ha estado cargado de creencias que, en la mayoría de los casos, no tienen suficientes fundamentos y, en muchos otros, tienen un sentido político o intenciones sin sustento técnico ni científico. El objetivo de este documento es presentar elementos de juicio para examinar algunos mitos relacionados con los sistemas de producción bovina con el fin de aportar al debate sobre el consumo de este tipo de carne, que ha tomado fuerza alrededor del mundo

Structural evolution of massive galaxies in the last 11 Gyr

This thesis describes the properties and evolution of massive ($M_{stellar}\geq10^{11} h_{70}^{-2} M_{\odot}$) galaxies at $0 < z < 3$, including their relationship to lower mass systems. Present-day massive galaxies are composed mostly of early-type objects, although it is unknown whether this was also the case at higher redshifts. In a hierarchical assembling scenario the morphological content of the massive population is expected to change with time from disk-like objects in the early Universe to spheroid-like galaxies at present. We first probe this theoretical expectation by compiling a large sample of massive galaxies in the redshift interval 0$<$z$<$3. Our sample of 1082 objects is composed of 207 local galaxies selected from the Sloan Digital Sky Survey, plus 875 objects observed with the HST from the POWIR/DEEP2 Survey and the GOODS NICMOS Survey. 639 of our objects have spectroscopic redshifts. Our morphological classification is done in the V-band restframe both quantitatively (using the S\'ersic index as a morphological proxy) and qualitatively (by visual inspection). Using both techniques we find a significant change in the dominant morphological class with cosmic time. The fraction of early-type galaxies among the massive galaxy population has changed from $\sim$20-30\% at z$\sim$3 to $\sim$70\% at z=0. Spheroid-like galaxies have been the predominant morphological massive class only since z$\sim$1. This morphological evolution is so far based on the detailed morphological analysis of these objects, which ultimately rests on the shape of their surface brightness profiles. To explore the consistency of this scenario, we examine the kinematic status of a small subset of these galaxies. We have observed in the H-band 10 massive galaxies at $z\sim1.4$ with the Integral Field Spectrograph SINFONI at VLT. Our sample of galaxies have been selected purely by their photometric stellar mass without accounting for any morphological criteria a priori, and having [OII] line equivalent widths of $> 15 \AA$ to secure their kinematical measurements. Through a 3D kinematical spectroscopy analysis we conclude that half (i.e. 50$\pm$7\%) of our galaxies are compatible with being rotationally supported disks in agreement with our previous photometric expectations. This is around a factor of two higher than what is observed in the present Universe for objects of the same stellar mass. Strikingly, the majority of these massive galaxies show clear and fairly large rotational velocity maps, implying that massive galaxies acquire rapidly rotational support and hence gravitational equilibrium. In addition, we have evidence, based on our measured velocity dispersions and imaging, to favour a picture in which minor (and major) mergers are the main driving force behind the evolution of this massive galaxy population. There is also cumulative evidence showing that the formation process for a number of these massive galaxies occur at even higher redshifts ($z > 5$) and that their morphological features are preserved when observing them in the UV restframe. Hence, we made use of the excellent capabilities of GNS to locate and study massive galaxies beyond $z = 3$ within our imaging and secondly determining whether the strong mass-size relation found for the most massive objects holds as well for lower mass objects. Our findings show the extreme compactness of massive objects at $z > 3$ and only a moderate evolution in size below our $10 {11} M_{\odot}$ mass limit

Manejo nutricional integrado para disminuir el tiempo en vivero de la palma de aceite (Elaeis Guineensis Y.) en el municipio de Codazzi-Cesar, Colombia.

Para los países tropicales, la palma de aceite representa una alternativa de excelentes perspectivas para el futuro. Este cultivo produce 10 veces más del rendimiento de aceite proporcionado por la mayoría de los otros cultivos oleaginosos, hecho que hace de este cultivo una gran fuente productora de aceite. En la zona norte colombiana en especial municipio de Codazzi departamento del cesar el cultivo de la palma ha tenido una gran expansión en su área productiva en los últimos años, hecho que hace posible pensar en la búsqueda de nuevas alternativas que ayuden a maximizar la producción. El manejo nutricional de las palmas es determinante para lograr un desarrollo adecuado, para tener una producción precoz y para que crezcan en estado sanitario satisfactorio. La demanda de nutrientes de un cultivo depende fundamentalmente de la edad de las palmas, del tipo de material sembrado, del suelo, del cultivo de cobertura, de los factores ambientales y de los niveles de agotamiento por producción de racimos. Los principales nutrientes que necesita la planta, durante los primeros años de crecimiento son: nitrógeno, fósforo y el potasio. El objetivo de la nutrición en la etapa de pre-vivero y de vivero en la palma aceitera es proporcionar un adecuado suministro de nutrientes a las plántulas para asegurar el máximo crecimiento

The structural and size evolution of star-forming galaxies over the last 11 Gyrs

We present new results on the evolution of rest-frame blue/UV sizes and Sersic indices of H$\alpha$-selected star-forming galaxies over the last 11 Gyrs. We investigate how the perceived evolution can be affected by a range of biases and systematics such as cosmological dimming and resolution effects. We use GALFIT and an artificial redshifting technique, which includes the luminosity evolution of H$\alpha$-selected galaxies, to quantify the change on the measured structural parameters with redshift. We find typical sizes of 2 to 3 kpc and Sersic indices of n~1.2, close to pure exponential disks all the way from z=2.23 to z=0.4. At z=0 we find typical sizes of 4-5 kpc. Our results show that, when using GALFIT, cosmological dimming has a negligible impact on the derived effective radius for galaxies with