Intrinsic noise profoundly alters the dynamics and steady state of morphogen-controlled bistable genetic switches

During tissue development, patterns of gene expression determine the spatial arrangement of cell types. In many cases, gradients of secreted signaling molecules - morphogens - guide this process. The continuous positional information provided by the gradient is converted into discrete cell types by the downstream transcriptional network that responds to the morphogen. A mechanism commonly used to implement a sharp transition between two adjacent cell fates is the genetic toggle switch, composed of cross-repressing transcriptional determinants. Previous analyses emphasize the steady state output of these mechanisms. Here, we explore the dynamics of the toggle switch and use exact numerical simulations of the kinetic reactions, the Chemical Langevin Equation, and Minimum Action Path theory to establish a framework for studying the effect of gene expression noise on patterning time and boundary position. This provides insight into the time scale, gene expression trajectories and directionality of stochastic switching events between cell states. Taking gene expression noise into account predicts that the final boundary position of a morphogen-induced toggle switch, although robust to changes in the details of the noise, is distinct from that of the deterministic system. Moreover, stochastic switching introduces differences in patterning time along the morphogen gradient that result in a patterning wave propagating away from the morphogen source. The velocity of this wave is influenced by noise; the wave sharpens and slows as it advances and may never reach steady state in a biologically relevant time. This could explain experimentally observed dynamics of pattern formation. Together the analysis reveals the importance of dynamical transients for understanding morphogen-driven transcriptional networks and indicates that gene expression noise can qualitatively alter developmental patterning

Minimum Action Path theory reveals the details of stochastic biochemical transitions out of oscillatory cellular states

Cell state determination is the outcome of intrinsically stochastic biochemical reactions. Tran- sitions between such states are studied as noise-driven escape problems in the chemical species space. Escape can occur via multiple possible multidimensional paths, with probabilities depending non-locally on the noise. Here we characterize the escape from an oscillatory biochemical state by minimizing the Freidlin-Wentzell action, deriving from it the stochastic spiral exit path from the limit cycle. We also use the minimized action to infer the escape time probability density function

Alternativas a la aplicación del parágrafo del artículo 57° de la ley 1453/2011, en relación a la rebaja de pena aplicable a capturados en situación de flagrancia

Este trabajo busca establecer si la aplicación del parágrafo del artículo 57 de la Ley 1453 de 2011, vulnera derechos fundamentales de los capturados en situación de fragancia y si como consecuencia de ello, existe la necesidad de implementar alternativas tendientes a restablecer las garantías conculcadas

Regional, Economic, and Environmental Implications of Dual Ethanol Technologies in Brazil

Climate change, food security, and energy efficiency have become universal challenges for global economic development and environmental conservation that demand in-depth multidisciplinary research. Biofuels have emerged as a decisive factor in the fight against global warming and air pollution from fossil fuel use, and they can play an important role in the development of poor as well as rich regions. In this work, we investigate the implications of biofuels for regional development in Brazil given its historic experience as an ethanol producer. We compare the environmental and economic impacts of the two predominant ethanol production techniques, in order to understand their effects on output, employment and income and also their potential to reduce the intensity of fossil fuel use and emissions of greenhouse gases. As we focus on a developing country, we also examine the distributional impacts of ethanol technology deployment, in terms of its potential contributions to poverty alleviation and the reduction of regional income inequalities. The production technologies currently used to produce ethanol differ spatially in Brazil, with a capital-intensive technology being used in the Southern regions of the country, and a traditional labor-intensive technology in the Northern regions. We take advantage of this regional variation to conduct a comparative regional analysis of ethanol production technology choice. We evaluate and compare the direct and indirect relationship between output, employment, income, energy intensity, and pollution emissions at the subnational level for the two ethanol production technologies, showing quantitatively the interrelations between the ethyl alcohol industry and the rest of the economy. We hypothesize that the adoption of capital-intensive ethanol production technology provides greater output and employment and lower environmental and energy costs than more traditional technologies and, in contrast, that the implementation of the traditional technology alleviates income inequality by increasing the income received by households in economically deprived regions

Percepción de la violencia como factor influyente en el bullying. Estudio realizado en Escuela No. 110, Juana de Arco, Zona 18.

Analizó la percepción de violencia que tienen los niños víctimas de bullying. El trabajo de investigación se realizó en la Escuela Juana de Arco, jornada matutina, zona 18, durante dos meses. La muestra estuvo conformada por 60 niños comprendidos entre 7 a 13 años de edad, sin distinción de género. Para recopilar información se utilizó una encuesta no estandarizada, que permitió recabar la opinión de los involucrados en el proceso educativo, los diferentes aspectos relacionados con la percepción de violencia en nuestro país y su relación con el bullying. Se realizó un análisis cuantitativo en base a los resultados obtenidos en la encuesta. Concluyó que, la percepción de violencia no es factor influyente para el desarrollo de conductas violentas. Asimismo que, la percepción no es un factor que influya directamente en el fenómeno del bullying. Determinó que la percepción de un fenómeno mayor, como la violencia, puede suscitarse a través de distintos procesos de socialización, así como, otros factores más sutiles, tales como la personalidad y patrones de crianza que influyan en la manifestación de las conductas violentas en los niños

Diseño de un producto turístico de juegos de azar, enfocado en la actividad de los casinos de la Zona Rosa de Bogotá.

128 páginasLos juegos de azar en el país siguen siendo relacionados con palabras como estafa, ilegalidad e inmoral, sin embargo, en los últimos 10 años se ha visto un incremento en el número de apostadores y establecimientos dedicados a esta actividad. Además, debido a regulaciones del gobierno, el sector de los juegos de azar genera y mueve una oportunidad económica para el país. En concordancia con lo anterior, el presente trabajo de investigación plantea el diseño de un producto turístico de casinos en una de las zonas más transitadas por turistas en Bogotá, la Zona Rosa de Bogotá. El objetivo de dicho producto consiste en atraer turistas nacionales internacionales que, motivados por el juego y su gusto por los casinos, acceden a participar en actividades que integran los casinos en la Zona Rosa de Bogotá.Gambling in the country continues to be related to words such as scam, illegality and immoral, however, in the last 10 years has seen an increase in the number of bettors and establishments dedicated to this activity. In addition, dueto government regulations, the gambling sector generales and moves an economic opportunity fer the country. In accordance with the above, the present investigation proposes the design of a tourist product of casinos in one of the zones most traveled by tourists in Bogota, the Zona Rosa of Bogota. The objective of this product is to attract international national tourists who, motivated by the game and their taste for casinos, agree to participate in activities that integrate the casinos in the Zona Rosa in Bogota.Magíster en Planificación y Gestión del TurismoMaestrí

Teaching STEMSS to Diverse Learners Through Changing Modalities: An eLearning Professional Development

The number of English language learners (ELs) in schools has significantly increased over the last decade and teachers are not fully prepared to teach this growing population because of limited training and a lack of skills necessary to address academic needs in both language and content. This mixed-methods study explored the effectiveness of an online professional development (PD) for increasing the teachers’ knowledge, skills, use, and self-efficacy in teaching science, technology, engineering, math, and social studies (STEMSS) content and the English language in tandem through changing modalities with teachers’ perceptions of the approach used within the PD. Vygotsky's socio-cultural theory and Lave and Wenger's community of practice theory guided the development, documentation and analysis of the impact of the PD. Twenty-four Arizona K-12 teachers of language learners (TLLs) were recruited. The teacher participants completed a pre-survey, then the online PD, and, finally, a post-survey and interview.Dependent t-test resultsprovided evidence that the PD significantly increased participants’ self-reported knowledge, use, and self-efficacy to support Els’ academic vocabulary in teaching whether face-to-face or online. The impact of the PD on these three constructs was further supported with data-driven themes generated from the interview data which increased the trustworthiness of the findings. Participants overwhelmingly valued the peer interaction for increasing their knowledge and understanding of effective pedagogical practices and their self-efficacy in supporting ELs in their classrooms whether teaching in-person or virtually through new methodological approaches that changed pedagogical practice

LA IMPORTANCIA DE LA DEPRECIACIÓN PARA LA TOMA DE DECISIONES ECONÓMICAS Y SU FINANCIAMIENTO EN DECISIONES DE REEMPLAZO Y CONSERVACIÓN DE MAQUINARIA

La depreciación es la reducción en el valor de un activo por lo que en el análisis de reemplazo, debe incluir el valor monetario al cual se vende el activo que se desea remplazar; este valor puede ser igual o mayor al valor en libros, que es en realidad el control contable de la depreciación, que tiene el activo al momento del reemplazo, lo cual tiene repercusiones directas en el ahorro o pago de impuestos, esto impacta directamente la decisión que se toma utilizando técnicas de ingeniería. El método de depreciación en línea recta es un método de libro mediante el cual se recupera la inversión de capital en propiedad tangible, cuya cuantía anual es deducible de impuestos, lo cual puede generar cambios reales de flujo de efectiv