Saltar navegación e ir al contenido principal

Estás filtrando por

Se encontraron 8967 resultados en recursos

Por: Andrés Ángel | Fecha: 10/06/2020

La tecnología aplicada al uso de grandes datos ha sido una herramienta importante para proveer información necesaria para dar respuestas a los retos de salud pública ante la pandemia de COVID-19, y en Colombia no ha sido la excepción. En este documento se analizan dos insumos de analítica de datos (rastreo digital de contactos y análisis agregado de movilidad, ambos basados en datos de telefonía celular) sobre los cuales se han tomado medidas de salud púbica en el país latinoamericano como, por ejemplo, determinar zonas de control diferencial dentro de una ciudad, el rastreo de contactos, y la identificación de potenciales superdispersores. Con base en una muestra de los datos utilizados, se hace una reflexión a la luz de los hallazgos reportados hasta el momento, especialmente desde una perspectiva de redes complejas de contactos y superdispersores, las cuales se ha mostrado tienen un papel crítico en el comportamiento de la epidemia. Los análisis expuestos son parte de una compleja interacción entre el contexto político y epidemiológico que hacen diversas sus respectivas implementaciones. Por último, se resalta que Colombia cuenta con diversos ejemplos de políticas públicas informadas por datos de última generación.

Fuente: Universidad del Rosario - Desafíos Formatos de contenido: Artículos

Temas:
Otros
COVID-19

Imagen de apoyo de New records and distribution extensions of some bird species in the Colombian Andean-Orinoco, department of Meta

Por: Johanna Isabel; Bonilla Rojas Murillo Pacheco | Fecha: 2016

Abstract: Here we present new records for four bird species to the Andean foothills of the department of Meta in Colombia, and we confirm the occurrence and document range extensions for these in the basin of the Orinoco river. These species are the Pied-billed Grebe, Podilymbus podiceps (Linnaeus 1758), the Yellowchinned Spinetail, Certhiaxis cinnamomeus (Gmelin 1788), the Yellow-browed Tyrant, Satrapa icterophrys (Viellot 1818), and the Glossy Ibis, Plegadis falcinellus (Linnaeus 1766). We also report new sightings of the Prothonotary Warbler, Protonotaria citrea (Boddaert 1783), Least Grebe, Tachybaptus dominicus (Linnaeus 1766), Oilbird, Steatornis caripensis (Humboldt 1817) and Epaulet Oriole, Icterus cayanensis (Linnaeus 1766) in the Colombian Andean-Orinoco (Meta department). Resumen: Aquí presentamos nuevos registros para cuatro especies de aves para las estribaciones Andinas del Departamento del Meta en Colombia, y confirmamos la ocurrencia y documentamos la extensión de rango para éstas especies en la cuenca del río Orinoco. Estas especies son el Zambullidor común Podilymbus podiceps (Linnaeus 1758), el chamicero barbiamarillo, Certhiaxis cinnamomeus (Gmelin 1788), el mosquero cejiamarillo, Satrapa icterophrys (Viellot 1818), y el ibis pico de hoz, Plegadis falcinellus (Linnaeus 1766). También reportamos nuevos registros de la Reinita cabecidorada, Protonotaria citrea (Boddaert 1783), el zambullidor chico, Tachybaptus dominicus (Linnaeus 1766), el guacharo, Steatornis caripensis (Humboldt 1817) y el turpial boyerito, Icterus cayanensis (Linnaeus 1766) en el Orinoco Andino de Colombia (departamento del Meta).

Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Artículos

Temas:
Otros

Imagen de apoyo de Resistance of primary microsurgical repair of palmar digital nerves to finger mobilization: A cadaver study

Por: Santiago; Hidalgo Díaz Salazar Botero | Fecha: 2016

Abstract: The aim of this study was to assess the resistance of microsurgically repaired proper palmar digital nerves (PPDN) to mobilization. Thirty-nine PPDN from fresh forearms cadavers were transected and then sutured using 10/0 nylon. After skin closure, each finger was forcefully flexed and extended 10 times. Out of the 39 repaired nerves, two were elongated and four were ruptured; this amounts to a 15.38% complication rate. We recommend immobilization of nerve repairs, although this contradicts most recent studies. Resumen: El objetivo de este trabajo es probar la resistencia de la neurorrafia de los nervios colaterales digitales. Se utilizaron 39 nervios colaterales digitales de 8 antebrazos de cadáver. La sección del nervio se realizó a nivel de la mitad de la falange proximal. La neurorrafia se realizó con Nylon 10-0. Se revisaron los especímenes para constatar el estado de las neurorrafias. Al considerar falla cualquier solución de continuidad o distensión de la zona de sutura se presenta falla de la misma el 15.38%. Los resultados de este estudio llevan a concluir que la inmovilización es necesaria para prevenir la ruptura de la neurorrafia de los nervios colaterales digitales.

Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Artículos

Temas:
Otros
Medicina

Imagen de apoyo de Relaciones entre las políticas del Estado colombiano y la situación jurídica de las comunidades autóctonas en el desarrollo de proyectos energéticos: el caso de los Embera-Katíos y la hidroeléctrica de Urrá

Por: Carlos Martín Carbonell Higuera | Fecha: 2011

El artículo presenta un análisis sobre el papel del Estado en las relaciones entre las comunidades indígenas y los proyectos hidroeléctricos en Colombia, así como las consideraciones jurídicas que se han puesto en juego en estas situaciones. El estudio toma como caso de estudio la construcción de la represa de Urrá en la región del Alto Sinú, la cual tuvo un impacto significativo sobre las condiciones de supervivencia cultural de una comunidad del pueblo Embera-Katío habitante en los territorios de influencia del proyecto. El trabajo hace un seguimiento a las decisiones judiciales de carácter constitucional respecto a la protección de los derechos de los pueblos indígenas, en el contexto de un Estado que se reconoce multicultural.

Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Artículos

Temas:
Otros
Ciencias sociales

Imagen de apoyo de Nitrogen Transformation and Removal in Maturation Ponds: Tracer Experiments with 15N Stable Isotopes in The United Kingdom in Summer

Por: Miller Alonso; Mara Camargo Valero | Fecha: 2007

The mechanisms and pathways by which nitrogen in its various forms is removed from waste stabilization ponds (WSP) have been a subject of much debate. In order to improve current understanding of the dynamics of inorganic and organic nitrogen removal in WSP systems, a study using stable nitrogen isotopes (15N) was undertaken on an experimental pilot-scale WSP system at Esholt Wastewater Treatment Works (Bradford, UK) in summer 2005 and 2006. A primary maturation pond was spiked with 15N-labelled ammonia (15NH4Cl) and 15N-labelled algae (Chlorella vulgaris) to track nitrogen transformations and removal associated with ammonia volatilization, nitrification, and algal uptake and its subsequent sedimentation and retention/hydrolysis in the sludge layer. Stable isotope analysis of 15N, in conjunction with performance indicators, revealed that total nitrogen is poorly removed (? 8%) but ammonium nitrogen removal is very good in summer (effluent concentration <2 mg NH4 + -N/L). The nitrogen cycle in maturation ponds is dominated by biological uptake as ammonium nitrogen is rapidly transformed into algal biomass as suspended organic nitrogen which then either leaves in the pond effluent or is sedimented as dead cells. Ammonia removal by volatilization makes little or no contribution to nitrogen removal and biological nitrate uptake prevents classical nitrification. Thus algal uptake of ammonium and subsequent sedimentation and retention in the sludge layer, after parti al ammonification of the algal organic nitrogen, appears to be the dominant mechanism for permanent nitrogen removal in maturation ponds during warm summer months in England.

Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Artículos

Temas:
Otros
Ingeniería

Imagen de apoyo de Local Wavelet-Vaguelette-Based Functional Classification of Gene Expression Data

Por: Margarita María; Ruiz Medina Rincón Hidalgo | Fecha: 2012

This paper focuses on the problem of functional statistical classification of gene expression curves. A local-wavelet-vaguelette-based functional logistic regression approach is presented. This approach is specially suitable for the classification of non-stationary singular (non- differentiable) curves. The performance of the methodology proposed is illustrated by implementing it for the classification of yeast cell-cycle temporal gene expression profiles. A simulation study is also carried out for comparison with other functional classification methodologies.

Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Artículos

Temas:
Otros

Imagen de apoyo de The economic value of environmental data: A notional insurance scheme for the European anchovy

Por: Margarita María; Mumford Rincón Hidalgo | Fecha: 2016

Anchovy population dynamics in the Gulf of Cádiz are governed by environmental processes. Sea surface temperature, intense easterly winds, and discharges from the Guadalquivir River have been identified as key factors determining early life stage mortality in this anchovy stock. We have constructed an environment-based recruitment model that simulates the abundance of juveniles under alternative parameters representing plausible biological hypotheses. We are able to evaluate how modelling environment-based recruitment can affect stock assessment and how responding to environmental information can beneﬁt ﬁshery management to allow greater average catch levels through the application of harvest control rules (HCRs) based on environmental conditions. While the environment-based rules generally increase allowable catch levels the variance in catch levels also increases, detracting from the improved value based only on average yield. In addition to changes in revenue, the probability of stock collapse is also reduced by using environmental factors in HCRs. To assess the value of these management systems we simulate a notional insurance scheme, which applies a value to both average yields and uncertainty. The value of the information-driven rules can be determined by comparing the relevant premiums payable for equal levels of insurance cover on revenue within each speciﬁc management regime. We demonstrate the net value of incorporating environmental factors in the management of anchovies in the Gulf of Cádiz despite the increased variability in revenue. This could be an effective method to describe outcomes for both commercial ﬁsheries and ecosystem management policies, and as a guide to management of other species whose dynamics are predictable based on in-season observations.

Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Artículos

Temas:
Otros

Imagen de apoyo de General state-space population dynamics model for Bayesian stock assessment

Por: Samu H. P.; Whitlock Mäntyniemi | Fecha: 2015

This study presents a state-space modelling framework for the purposes of stock assessment. The stochastic population dynamics build on the notion of correlated survival and capture events among individuals. The correlation is thought to arise as a combination of schooling behaviour, a spatially patchy environment, and common but unobserved environmental factors affecting all the individuals. The population dynamics model isolates the key biological processes, so that they are not condensed into one parameter but are kept separate. This approach is chosen to aid the inclusion of biological knowledge from sources other than the assessment data at hand. The model can be tailored to each case by choosing appropriate models for the biological processes. Uncertainty about the model parameters and about the appropriate model structures is then described using prior distributions. Different combinations of, for example, age, size, phenotype, life stage, species, and spatial location can be used to structure the population. To update the prior knowledge, the model can be fitted to data by defining appropriate observation models. Much like the biological parameters, the observation models must also be tailored to fit each individual case.

Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Artículos

Temas:
Otros

Imagen de apoyo de Improving Road Transport Operations using Lean Thinking

Por: José Arturo; Beltran Forero Garza Reyes | Fecha: 2017

This paper documents a case study where the transport operations of a word leading provider of paper-based packaging solutions operating in Bogota, Colombia, were measured and improved using lean concepts, methods and tools. The methodology consisted of: (1) direct observations of the transport operations; (2) collection and analysis of data; (3) creation of a Transportation Value Stream Map (TVSM); (4) measurement of the Transportation Overall Vehicle Effectiveness (TOVE); and (5) proposal of improvement recommendations. The TVSM identified six wastes: waiting, resource utilisation, excess movement, over-production, over-processing and behavioural. The TOVE measure resulted in an efficiency of 54%. The study proposed improvement recommendations based on the results of the TVSM and TOVE.

Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Artículos

Temas:
Otros

Imagen de apoyo de Recruiting at the edge: Kinetic energy inhibits anchovy populations in the western Mediterranean

Por: Javier; Macías Ruiz Segura | Fecha: 2013

The Strait of Gibraltar replenishes the Mediterranean with Atlantic waters through an intense eastward current known as the Atlantic Jet (AJ). The AJ fertilizes the southwestern Mediterranean and is considered to be the ultimate factor responsible for the comparatively high fish production of this region. Here, we perform an analysis of the available historical catches and catch per unit effort (CPUE), together with a long series of surface currents, kinetic energy and chlorophyll concentration. We show that the high kinetic energy of the AJ increases primary production but also negatively impacts the recruitment of anchovy. We contend that anchovy recruitment in the region is inhibited by the advection and dispersion of larvae and post-larvae during periods of strong advection by the AJ. The inhibitory impact of kinetic energy on anchovy landings is not a transient but rather a persistent state of the system. An exceptional combination of events creates an outbreak of this species in the Alboran Sea. These events depend on the Mediterranean-Atlantic exchange of water masses and, therefore, are highly sensitive to climate changes that are projected, though not always negatively, for fish landings.

Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Artículos

Temas:
Otros