La modelación matemática y la construcción de la covariación lineal.

El presente trabajo de investigación describe los procesos de modelación matemática en situaciones de covariación lineal, que siguen los estudiantes de ciclo V de la Institución Educativa Distrital -Quiroga Alianza cuando se enfrentan a situaciones de covariación. Ante las dificultades identificadas en dicho en torno referente al desarrollo del pensamiento variacional, proponemos la implementación de una estrategia didáctica para un grupo de estudiantes pertenecientes al ámbito de la educación básica secundaria y la media vocacional colombiana. Este trabajo toma como referencia los trabajos de Duval (1999), Vasco (2002), Villa (2007) Biembengut y Hein (2004) sobre modelación matemática, modelos matemáticos y sistemas de representación entre otros. El trabajo se centró en la exploración de las características de los procesos de modelación de los estudiantes, a partir de la aplicación de una secuencia didáctica encaminada a generar una modelación matemática, que a su vez permiten, una aproximación hacia algunos atributos de la función lineal. A partir de los resultados vinculados a tres actividades específicas de modelación, se categorizan los procesos de tres estudiantes a partir de los registros de lenguaje: natural, tabular y gráfico, como también de los hallazgos provenientes del lenguaje simbólico. Finalmente, se analiza cómo se dan los procesos de modelación en situaciones de covariación lineal a partir de un sistema de categorías basado en los momentos y fases de la modelación de Vasco (2002) y, a la vez, se da cuenta sobre la manera en la que la modelación matemática se constituye como una estrategia didáctica para la enseñanza, que permite la construcción de un modelo, la construcción de una covariación lineal y una posible aproximación al concepto de función lineal.This research describes mathematical modeling processes in linear covariation situations, developed by the students of Cicle V of the Institución Educativa Distrital -Quiroga Alianza when they deal with covariation situations. Given the difficulties identified in the regarding development of variational thinking, we put forward the implementation of an educational strategy which is adressed to a group of secondary and high school students in Colombia. This research takes as reference previous papers from Duval (1999), Vasco (2002), Villa (2007) Biembengut and Hein (2004) concerning mathematical modeling, mathematical models and representation systems, among othes. This work is centered on the examination of the modeling processes features of students from the application of a didactic sequence, aimed to create a mathematic modeling that permits an approach towards linear function generalities. From the results binded to three specific modeling activities, the students processes are categorized from the language register: natural, tabular and graphic, as well as the discoveries coming from the symbolic language. Finally, it is analised how do modeling processes are given in lineal covariational situations from a system of categories based on moments and stages taken from the modeling of Vasco (2002) and at the same time, it accounts for the way in which mathematical modeling is constituted as a educational strategy for learning, that allows the construction of a model, a linear covariation, and a possible approach to the concept of linear function.Magíster en EducaciónMaestrí

Graphical Framework for Categorizing Data Capabilities and Properties of Objects in the Internet of Things

Things are the core of the Internet of Things (IoT) and must be properly characterized according to the different functions they accomplish. Identifying their capabilities and combining them as sets provides a view on the single or joint properties of existing things and guide in properly designing and building new things while maximizing their potential benefits within an IoT system or application. Building on five essential but independent capabilities of things (Identification, Localization, Sensing, Actuation, and Processing), four categories or groups of things are defined. These groups comprise a particular view of the diversity of objects found in the IoT, as trackable, data, interactive, or smart objects. In this paper, a description of the aforementioned capabilities is presented, stating how each of the groups of objects includes them. Then, given that data are the most important assets for both organizations and individuals a further description of the data objects group is made, proposing a graphical categorization framework that thoroughly describes and measures the level in which each of these capabilities is contained and how it contributes to the performance and data properties of any data object

Reporte Estabilidad Financiera - Primer Semestre de 2020

In the face of the multiple shocks currently experienced by the domestic economy (resulting from the drop in oil prices and the appearance of a global pandemic), the Colombian financial system is in a position of sound solvency and adequate liquidity. At the same time, credit quality has been recovering and the exposure of credit institutions to firms with currency mismatches has declined relative to previous episodes of sudden drops in oil prices. These trends are reflected in the recent fading of red and blue tonalities in the performance and credit risk segments of the risk heatmaps in Graphs A and B.1 Naturally, the sudden, unanticipated change in macroeconomic conditions has caused the appearance of vulnerabilities for short-term financial stability. These vulnerabilities require close and continuous monitoring on the part of economic authorities. The main vulnerability is the response of credit and credit risk to a potential, temporarily extreme macroeconomic situation in the context of: (i) recently increased exposure of some banks to household sector, and (ii) reductions in net interest income that have led to a decline in the profitability of the banking business in the recent past. Furthermore, as a consequence of greater uncertainty and risk aversion, occasional problems may arise in the distribution of liquidity between agents and financial markets. With regards to local markets, spikes have been registered in the volatility of public and private fixed income securities in recent weeks that are consistent with the behavior of the international markets and have had a significant impact on the liquidity of those instruments (red portions in the most recent past of some market risk items on the map in Graph A). In order to adopt a forward-looking approach to those vulnerabilities, this Report presents a stress test that evaluates the resilience of credit institutions in the event of a hypothetical scenario thatseeks to simulate an extreme version of current macroeconomic conditions. The scenario assumes a hypothetical negative growth that is temporarily strong but recovers going into the middle of the coming year and has extreme effects on credit quality. The results suggest that credit institutions have the ability to withstand a significant deterioration in economic conditions in the short term. Even though there could be a strong impact on credit, liquidity, and profitability under the scenario being considered, aggregate capital ratios would probably remain at above their regulatory limits over the horizon of a year. In this context, the recent measures taken by both Banco de la República and the Office of the Financial Superintendent of Colombia that are intended to help preserve the financial stability of the Colombian economy become highly relevant. In compliance with its constitutional objectives and in coordination with the financial system’s security network, Banco de la República will continue to closely monitor the outlook for financial stability at this juncture and will make the decisions that are necessary to ensure the proper functioning of the economy, facilitate the flow of sufficient credit and liquidity resources, and further the smooth functioning of the payment system. Juan José Echavarría Governo

Financial Stability Report - Second Semester of 2020

The Colombian financial system has not suffered major structural disruptions during these months of deep economic contraction and has continued to carry out its basic functions as usual, thus facilitating the economy's response to extreme conditions. This is the result of the soundness of financial institutions at the beginning of the crisis, which was reflected in high liquidity and capital adequacy indicators as well as in the timely response of various authorities. Banco de la República lowered its policy interest rates 250 points to 1.75%, the lowest level since the creation of the new independent bank in 1991, and provided ample temporary and permanent liquidity in both pesos and foreign currency. The Office of the Financial Superintendent of Colombia, in turn, adopted prudential measures to facilitate changes in the conditions for loans in effect and temporary rules for rating and loan-loss provisions. Finally, the national government expanded the transfers as well as the guaranteed credit programs for the economy. The supply of real credit (i.e. discounting inflation) in the economy is 4% higher today than it was 12 months ago with especially marked growth in the housing (5.6%) and commercial (4.7%) loan portfolios (2.3% in consumer and -0.1% in microloans), but there have been significant changes over time. During the first few months of the quarantine, firms increased their demands for liquidity sharply while consumers reduced theirs. Since then, the growth of credit to firms has tended to slow down, while consumer and housing credit has grown. The financial system has responded satisfactorily to the changes in the respective demands of each group or sector and loans may grow at high rates in 2021 if GDP grows at rates close to 4.6% as the technical staff at the Bank expects; but the forecasts are highly uncertain. After the strict quarantine implemented by authorities in Colombia, the turmoil seen in March and early April, which was evident in the sudden reddening of macroeconomic variables on the risk heatmap in Graph A,[1] and the drop in crude oil and coal prices (note the high volatility registered in market risk for the region on Graph A) the local financial markets stabilized relatively quickly. Banco de la República’s credible and sustained policy response played a decisive role in this stabilization in terms of liquidity provision through a sharp expansion of repo operations (and changes in amounts, terms, counterparties, and eligible instruments), the purchases of public and private debt, and the reduction in bank reserve requirements. In this respect, there is now abundant aggregate liquidity and significant improvements in the liquidity position of investment funds. In this context, the main vulnerability factor for financial stability in the short term is still the high degree of uncertainty surrounding loan quality. First, the future trajectory of the number of people infected and deceased by the virus and the possible need for additional health measures is uncertain. For that reason, there is also uncertainty about the path for economic recovery in the short and medium term. Second, the degree to which the current shock will be reflected in loan quality once the risk materializes in banks’ financial statements is uncertain. For the time being, the credit risk heatmap (Graph B) indicates that non-performing and risky loans have not shown major deterioration, but past experience indicates that periods of sharp economic slowdown eventually tend to coincide with rises in non-performing loans: the calculations included in this report suggest that the impact of the recession on credit quality could be significant in the short term. This is particularly worrying since the profitability of credit establishments has been declining in recent months, and this could affect their ability to provide credit to the real sector of the economy. In order to adopt a forward-looking approach to this vulnerability, this Report presents several stress tests that evaluate the resilience of the liquidity and capital adequacy of credit institutions and investment funds in the event of a hypothetical scenario that seeks to simulate an extreme version of current macroeconomic conditions. The results suggest that even though there could be strong impacts on the credit institutions’ volume of credit and profitability under such scenarios, aggregate indicators of total and core capital adequacy will probably remain at levels that are above the regulatory limits over the horizon of a year. At the same time, the exercises highlight the high capacity of the system's liquidity to face adverse scenarios. In compliance with its constitutional objectives and in coordination with the financial system's security network, Banco de la República will continue to closely monitor the outlook for financial stability at this juncture and will make the decisions that are necessary to ensure the proper functioning of the economy, facilitate the flow of sufficient credit and liquidity resources, and further the smooth operation of the payment systems. Juan José Echavarría Governo

Caracterización en la dinámica espacial de los macrohábitats acuáticos en la región de La Mojana

Con el fin de consolidar el levantamiento y análisis de la información sobre ecología en los humedales de La Mojana, este documento describe la biodiversidad asociada a las zonas de transición entre los principales macrohábitats acuáticos naturales identificados en esta región. Caracterizando por sectores desde la transición más húmeda hasta la más seca, identificando y caracterizando los micro-hábitats presentes dentro de cada uno de ellos e identificando la ocupación en el territorio por los distintos grupos biológicos.Bogotá, ColombiaPrograma Gestión Territorial de la Biodiversida

Financial Stability Report - Second Semester of 2021

Banco de la República’s main objective is to preserve the purchasing power of the currency in coordination with the general economic policy that is intended to stabilize output and employment at long-term sustainable levels. Properly meeting the goal assigned to the Bank by the 1991 Constitution critically depends on preserving financial stability. This is understood to be a general condition in which the financial system assesses and manages the financial risks in a way that facilitates the economy’s performance and efficient allocation of resources while, at the same time, it is able to, on its own, absorb, dissipate, and mitigate the shocks that may arise as a result of adverse events. This Financial Stability Report meets the goal of giving Banco de la República’s diagnosis of the financial system’s and its debtors’ recent performance as well as of the main risks and vulnerabilities that could affect the stability of the Colombian economy. In this way, participants in financial markets and the public are being informed, and public debate on trends and risks affecting the system is being encouraged. The results presented here also serve the monetary authority as a basis for making decisions that will enhance financial stability in the general context of its objectives. In recent months, several positive aspects of the financial system have preserved a remarkable degree of continuity and stability: the liquidity and capital adequacy of financial institutions have remained well above the regulatory minimums at both the individual and consolidated levels, the coverage of past-due loans by loan-loss provisions remains high, and the financial markets for public and private debt and stocks have continued to function normally. At the same time, a surge in all the types of loan portfolios, a sharp downturn in the non-performing loan portfolio, and a rise in the profitability of credit institutions can be seen for the first time since the beginning of the pandemic. In line with the general recovery of the economy, the main vulnerability to the stability of the Colombian financial system identified in the previous edition—uncertainty about changes in the non-performing loans portfolio—has receded and remains on a downward trend. In this edition, the main source of vulnerability identified for financial stability in the short term is the system’s exposure to sudden changes in international financial conditions; the results presented in this Report indicate that the system is sufficiently resilient to such scenarios. In compliance with its constitutional objectives and in coordination with the financial system’s security network, Banco de la República will continue to closely monitor the outlook for financial stability at this juncture and will make the decisions necessary to ensure the proper functioning of the economy, facilitate the flow of sufficient credit and liquidity resources, and further the smooth functioning of the payment system. Leonardo Villar Gomez Governor Box 1 -Decomposition of the Net Interest Margin in Colombia and Chile Wilmar Cabrera Daniela Rodríguez-Novoa Box 2 - Spatial Analysis of New Home Prices in Bogota, Medellín, and Cali Using a Geostatistical Approach María Fernanda Meneses Camilo Eduardo Sánchez Box 3 - Interest Rate Model for the SYSMO Stress Test Exercise Wilmar Cabrera Diego Cuesta Santiago Gamba Camilo Gómez Box 4 - The Transition from LIBOR and other International Benchmark Rates Daniela X. Gualtero Briceño Javier E. Pirateque Niñ

Standardized incidence ratios and risk factors for cancer in patients with systemic sclerosis: Data from the Spanish Scleroderma Registry (RESCLE)

Aim: Patients with systemic sclerosis (SSc) are at increased risk of cancer, a growing cause of non-SSc-related death among these patients. We analyzed the increased cancer risk among Spanish patients with SSc using standardized incidence ratios (SIRs) and identified independent cancer risk factors in this population. Material and methods: Spanish Scleroderma Registry data were analyzed to determine the demographic characteristics of patients with SSc, and logistic regression was used to identify cancer risk factors. SIRs with 95% confidence intervals (CIs) relative to the general Spanish population were calculated. Results: Of 1930 patients with SSc, 206 had cancer, most commonly breast, lung, hematological, and colorectal cancers. Patients with SSc had increased risks of overall cancer (SIR 1.48, 95% CI 1.36-1.60; P < 0.001), and of lung (SIR 2.22, 95% CI 1.77-2.73; P < 0.001), breast (SIR 1.31, 95% CI 1.10-1.54; P = 0.003), and hematological (SIR 2.03, 95% CI 1.52-2.62; P < 0.001) cancers. Cancer was associated with older age at SSc onset (odds ratio [OR] 1.22, 95% CI 1.01-1.03; P < 0.001), the presence of primary biliary cholangitis (OR 2.35, 95% CI 1.18-4.68; P = 0.015) and forced vital capacity <70% (OR 1.8, 95% CI 1.24-2.70; P = 0.002). The presence of anticentromere antibodies lowered the risk of cancer (OR 0.66, 95% CI 0.45-0.97; P = 0.036). Conclusions: Spanish patients with SSc had an increased cancer risk compared with the general population. Some characteristics, including specific autoantibodies, may be related to this increased risk

Guías colombianas de electrofisiología no invasiva

Los métodos diagnósticos no invasivos son el pilar inicial del estudio de cualquier paciente con una patología en particular, de ahí que sean los exámenes más solicitados y constituyan una importante carga en costos para un sistema de salud.Q4Guías1-12

Tejiendo diálogos. Reflexiones contemporáneas sobre la expresión y el sentido

El presente libro se divide en tres grandes bloques temáticos que contienen a los conceptos guía del título: Complejidad, expresión y sentido y, se organizan de acuerdo con lo que podría considerarse manifestaciones contextuales de las relaciones complejas y manifestaciones de sentido, que emergen como organizadoras a partir de diferentes formas en las que se manifiesta el diseño, las artes y la comunicación, El primer bloque obedece al principio dialógico de la no exclusión en donde que reza: “A no puede ser A y no A” y se titula: Complejidad y expresiones de la cultura contemporánea componiéndose por cinco textos que tocan dimensiones problemáticas en contextos contemporáneos como la intervención urbana y el feminismo como diálogo a través de la imagen y la educación; los discursos de odio como emergencia y la aparición de nuevas necesidades de formación universitaria ante ámbitos de competencia complejos. La primera sección titulada Condiciones emergentes de organización y sentido se presentan los textos en los que la expresión y el sentido aparecen como formas específicas a través de los cuáles es posible no solo asegurar las fronteras de operaciones sociales sino proyectarlas hacia nuevas condiciones de organización y sentido como sería el mundo de la virtualidad. En la segunda sección compuesta por cinco ensayos que de algún modo coinciden en la importancia de los puntos de conexión e interacciones en los fenómenos complejos como inductores de orden-desorden-complejidad, ponen de manifiesto su papel como productores de relaciones que permiten dar cuenta de la incertidumbre, comprender y exponer acontecimientos a nivel educativo, social y artístico. Finalmente en la tercera sección, el bloque que cierra el contenido del libro, se compone por cinco textos que dentro de su argumentación podrían verse alineados con el postulado de Nicolescu del Tercero incluido en donde A no puede ser A y a la vez existe no A, aludiendo a dimensiones problemáticas en contextos contemporáneos como: la intervención urbana y el feminismo como diálogo a través de la imagen y la educación; los discursos de odio como emergencia y la aparición de nuevas necesidades de formación universitaria ante ámbitos de competencia complejos.Olivia Fragoso Susunaga, María Teresa Olalde Ramos y Gustavo Garduño Oropeza, coordinadores

Doñana. Acta vertebrata. vol 17 (2)

Tres ejemplos de aplicación de métodos indirectos para la estimación de parametros poblacionales en cérvidoAlimentación de la garza real (Ardea cinerea) en la cuenca del Duero (España) durante el periodo reproductoDistribución y tamaño de colonias de buitre leonado (Gyps fulvus) en el alto Ebro y zona Cantábrica próximaDistribución y hábitat del visón americano (Mustela vison Schreber) en el sistema CentraRégimen alimentario del erizo (Erinaceus europaeus L.) durante verano y otoño en setos de la provincia de León (NO de España)Señales sociales de la espátula (Platalea leucorodia) durante el periodo reproductivoVariación del peso corporal en Arvicola terrestris (Rodentia, Arvicolidae) del nordeste ibéricoSobre el dimorfismo sexual en el cráneo del gato montés Felix silvestris Schreber, 1777 del sudoeste ibéricoUn nuevo núcleo poblacional de Apodemus flavicollis (Melchior, 1834) en la Península Ibérica.Selección de la lechuza común (Tyto alba) sobre el topillo común (Microtus duodecimcostatus)Importancia de la vegetación emergente en el comportamiento alimenticio de la fochaObservaciones sobre el papel del lagarto ocelado (Lacerta lepida Daudin), el erizo (Erinaceus europaeus L.) y el tejón (Meles meles L.) en la dispersión de semillasComentarios sobre los estimadores empleados en el método de la batida.El uso de la batida como método de censo: una replicaPeer reviewe