450 research outputs found
English Language Learning through Physical and Social Environment Interaction at Adolfo Kolping School
A través de una serie de clases piloto, este proyecto de investigación tuvo como objetivo introducir la enseñanza didáctica del idioma inglés en estudiantes de primaria a través del compromiso con el entorno físico y social proporcionado por la escuela. Tuvo como fin examinar hábitos, actitudes, experiencias y eventos, el enfoque de investigación se construyó mediante la aplicación de encuestas, cuestionarios, conocimientos y observaciones del proceso de enseñanza. Se recopiló alguna información. Se desarrollaron clases piloto con 22 alumnos de quinto grado de la Escuela Técnica Adolfo Kolping, con el objetivo de poner en práctica métodos de enseñanza que desarrollarán determinadas habilidades en los alumnos y promoverán la interacción con el entorno escolar a través de la experimentación con el mundo real, en el que para la realización del estudio se han utilizado todo tipo de elementos de la escuela.Through a series of pilot classes, this research project aimed to introduce didactic teaching of the English language in elementary school students through engagement with the physical and social environment provided by the school. In order to examine habits, attitudes, experiences and events, the research approach was built through the application of surveys, questionnaires, knowledge and observations of the teaching process. Some information was collected. Pilot classes were developed with 22 students from the fifth grade of Adolfo Kolping Technical School, with the aim of putting into practice teaching methods that will develop certain skills in students and promote interaction with the school environment through experimentation with the real world, in which all kinds of elements of the school have been used to carry out the study
Kinematic analysis of the stage 5 design of the Kevitsa open pit mine
Abstract. The development of a new pushback in the Kevitsa Open Pit Mine has raised concerns regarding the potential impact of minor and major geological discontinuities on the overall stability of the pit. Furthermore, the daily mining operations are continuously threatened by frequent rock falls that occasionally exceed the bench slope scale, posing hazards in terms of safety and economics. Despite these challenges, the structures or group of structures responsible for most of the rock falls have not been confidently identified. This study reviews the effect of the structural features within the Kevitsa area into the open pit excavation and the proposed slopes of the Stage 5 pit design. To achieve this, structural mapping of rock surfaces was performed using 3D photogrammetry. The collected data was integrated with geotechnical logging data and laser scan data to characterize the dominant joint orientations of the deposit. Kinematic analyses of rock blocks were carried out by stereographic projection techniques to identify potential instabilities in the bench, inter-ramp, and overall slopes of the Stage 5 pit design. Results establish that two areas in the current pit and Stage 5 have major slope instability, where bench and inter-ramp slope failures are attributed to specific joint sets. Moreover, potential planar and wedge failures of overall slope scale are identified. Based on the findings, recommendations for pit optimization and geotechnical investigations are made
On the properties of compacton-anticompacton collisions
We study the properties of compacton-anticompacton collision processes. We
compare and con- trast results for the case of compacton-anticompacton
solutions of the K(l, p) Rosenau-Hyman (RH) equation for l = p = 2, with
compacton-anticompacton solutions of the L(l,p) Cooper-Shepard- Sodano (CSS)
equation for p = 1 and l = 3. This study is performed using a Pad\'e
discretization of the RH and CSS equations. We find a significant difference in
the behavior of compacton- anticompacton scattering. For the CSS equation, the
scattering can be interpreted as "annihila- tion" as the wake left behind
dissolves over time. In the RH equation, the numerical evidence is that
multiple shocks form after the collision which eventually lead to "blowup" of
the resulting waveform.Comment: 8 pages, 7 figure
Stability and dynamical properties of Rosenau-Hyman compactons using Pade approximants
We present a systematic approach for calculating higher-order derivatives of
smooth functions on a uniform grid using Pad\'e approximants. We illustrate our
findings by deriving higher-order approximations using traditional second-order
finite-differences formulas as our starting point. We employ these schemes to
study the stability and dynamical properties of K(2,2) Rosenau-Hyman (RH)
compactons including the collision of two compactons and resultant shock
formation. Our approach uses a differencing scheme involving only nearest and
next-to-nearest neighbors on a uniform spatial grid. The partial differential
equation for the compactons involves first, second and third partial
derivatives in the spatial coordinate and we concentrate on four different
fourth-order methods which differ in the possibility of increasing the degree
of accuracy (or not) of one of the spatial derivatives to sixth order. A method
designed to reduce roundoff errors was found to be the most accurate
approximation in stability studies of single solitary waves, even though all
derivates are accurate only to fourth order. Simulating compacton scattering
requires the addition of fourth derivatives related to artificial viscosity.
For those problems the different choices lead to different amounts of
"spurious" radiation and we compare the virtues of the different choices.Comment: 12 figure
Enfermedad Pulmonar Obstructiva Crónica de posible origen ocupacional y su relación con exposición laboral a aerosoles sólidos en trabajadores atendidos en una Institución prestadora de servicios de salud en Yumbo - Valle del Cauca (2011 – 2013)
RESUMEN. Introducción: La Organización Internacional del Trabajo (OIT), la Organización Mundial de la Salud (OMS), la National Heart, Lung and Blood institute (NHLBI) y diferentes estudios epidemiológicos como el Platino, el Prepocol, además de la normatividad nacional del Ministerio de Trabajo de Colombia plantean la existencia de la Enfermedad Pulmonar Obstructiva Crónica (EPOC) de origen ocupacional. El diagnóstico de la EPOC trae en sí el reto de la determinación de su origen, lo cual no es fácil, incluso cuando las condiciones para ello puedan ser claras. Objetivo: Determinar la prevalencia de EPOC ocupacional y su relación con exposición laboral a aerosoles sólidos en trabajadores atendidos en una Institución Prestadora de Salud (IPS) en Yumbo - Valle del Cauca, (2011 – 2013). Metodología: estudio descriptivo retrospectivo con datos secundarios de 117 registros tomados de la base de datos del proyecto macro intitulado “EPOC ocupacional, prevalencia en trabajadores atendidos en una IPS de Yumbo (2011-2013)” con información de la historia clínica y cuestionario de síntomas respiratorios. Se establecieron a priori dos definiciones operacionales: EPOC de posible origen ocupacional según criterios establecidos por la OIT y exposición laboral a agentes químicos que puedan generar EPOC. Se realizó análisis estadístico descriptivo, prevalencias e intervalos de confianza del 95%. Para examinar la relación entre exposición laboral y EPOC ocupacional se empleó Chi2, prueba exacta de Fisher y la prueba ANOVA para analizar el comportamiento de la edad dentro del grupo de expuestos y no expuestos, se estableció a priori un nivel de significación estadística α =0,05. Resultados: La prevalencia de EPOC ocupacional fue de 12%, IC (95%): 4% - 20%; en el grupo expuesto ocupacionalmente fue de 19,5% y en el no expuesto fue de 3,0% con diferencias estadísticamente significantes (valor_p = 0,037). Conclusiones: se encontró relación estadísticamente significante entre exposición laboral y EPOC de posible origen ocupacional.ABSTRACT. Introduction: The International Labor Organization (ILO), the World Health Organization (WHO), the National Heart, Lung and Blood institute (NHLBI) and different epidemiological studies such as Platinum, Prepocol, labor laws of Colombia raise the existence of the Chronic Obstructive Pulmonary Disease (COPD) of occupational origin. The diagnosis of COPD brings with it the challenge of determining its origin, which is not easy, even when the conditions for it can be clear. Objective: To determine the prevalence of occupational COPD and its relation with occupational exposure to solid aerosols in workers treated at a Health Provider Institution (IPS) in Yumbo - Valle del Cauca, (2011 - 2013). Methodology: retrospective descriptive study with secondary data from 117 records taken from the database of the macro project titled "occupational COPD, prevalence in workers treated at a Yumbo IPS (2011-2013)" with information from the medical history and symptom questionnaire Respiratory. Two operational definitions were established a priori: COPD of possible occupational origin according to criteria established by the ILO and occupational exposure to chemical agents that can generate COPD. Descriptive statistical analysis, prevalence and 95% confidence intervals were performed. To examine the relationship between occupational exposure and occupational COPD we used Chi2, Fisher's exact test and the ANOVA test to analyze the behavior of age within the group of exposed and non-exposed, we established a priori a level of statistical significance α = 0 , 05. Results: The prevalence of occupational COPD was 12%, CI (95%): 4% - 20%; In the occupationally exposed group it was 19.5% and in the non-exposed group it was 3.0% with statistically significant differences (p value = 0.037). Conclusions: a statistically significant relationship was found between occupational exposure and COPD of possible occupational origin.2019-08-01 06:01:01: Script de automatizacion de embargos. info:eu-repo/date/embargoEnd/2019-06-0
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In Utero Exposure to Arsenic and Mercury : Epigenome-Wide Associations and Newborn Health Outcomes
Mercury and arsenic are known developmental toxicants and environmental exposures are ubiquitous worldwide from natural and anthropogenic sources. Prenatal exposure to both contaminants are independently associated with adverse perinatal health outcomes and latent disease risk that could be in part mediated by epigenetic reprogramming events. Fetal programming events involving DNA methylation occur early during fetal development and are sensitive to environmental stimuli, potentially influencing disease risk throughout the life course. This research evaluated the epigenetic disruption of DNA methylation associated with exposure to mercury and arsenic in utero, and the potential impact on infant birth outcomes.
The first study provides evidence that exposure to mercury during fetal development can contribute to epigenetic variability and immune cell proportion changes in infant cord-blood collected at birth. The data also suggests that exposure to mercury and arsenic, even at low levels, may interact to impact the epigenome in cord-blood. The second study evaluated the epigenome wide association of arsenic exposure in utero for placenta, umbilical artery and umbilical vein endothelial cells (HUVEC). Our results show that prenatal arsenic exposure alters DNA methylation of umbilical artery and placenta but there is limited evidence for an association in HUVEC. We also identified DNA methylation disruption of key biological pathways related to adverse health outcomes previously associated with arsenic exposure in epidemiological studies. Lastly, the third study evaluated the direct association between prenatal arsenic exposure, birth gestational age and birth weight, as well as the indirect effect of arsenic exposure mediated through DNA methylation in cord-blood. We observed that the inverse relationship between arsenic exposure in utero and birth gestational age was completely mediated through DNA methylation of selected CpG loci. No association or mediation was observed between prenatal arsenic exposure and infant birth weight.
These results provide evidence that exposure to arsenic and mercury in utero, two common environmental contaminants, can influence epigenetic programming of DNA methylation in different biological human tissues. Particularly, the effect of arsenic exposure on gestational age was mediated through CpG methylation of infant cord-blood, which is a critical parameter of infant health and associated with disease later in life. Future studies should evaluate if these epigenetic changes are persistent and associated with disease risk later in life. The design of public health interventions that target prevention of environmental exposures in utero that may increase disease risk later in life provide a unique opportunity for early disease prevention. Overall, these results will guide future research and inform regulatory guidelines to help reduce arsenic and mercury exposure, particularly during pregnancy
The BIophysical Basis for Adaptation: Predicting Evolutionary Outcomes from Physicochemical Properties
Experimental evolution can be used in conjunction with biophysical characterization of enzymes to determine the link between cellular fitness and physicochemical properties of enzymes. Sequencing of ancestral and evolved populations can be used to compare the outcomes of experimental evolution with measurements of fitness, using growth rate assays to correlate fitness outcomes to specific mutations. Combined with enzyme assays of kinetic properties that can provide a direct link between genotypic and phenotypic changes of adaptive mutants, we can model the complex relationship between genotypic changes and evolutionary outcomes.
Two experimental evolution systems were used to explore the link between enzyme properties and fitness outcomes. In the first series of studies, a “weak link” evolution experiment was used to explore the effect of reducing selection strength on altering accessible pathways for adaptation. In the weak link method the essential gene for adenylate kinase (AK) was replaced in the chromosome of the thermophile Geobacillus stearothermophilus with a homolog from Bacillus subtilis. Replacement with the maladapted gene confers a high fitness cost, and therefore mutations that restore function of AK are strongly favored. Two triple mutants of AK containing a new combination of single point mutants identified under strong selection, AKQ199R/A193V/Q16L and AKQ199R/T179I/Q16L were discovered through an adaptation experiment using a weak temperature ramp; suggesting that the adaptive landscape for AK thermostability is highly constrained. A thermostable coupled assay was developed for measuring adenylate kinase activity using LDHTTHERMOPHILUS and PKGSTEAROTHERMOPHILUS at high temperatures. The triple mutants had increased function compared with the double mutant ancestors, but the triple mutants displayed diminishing returns epistasis on fitness.
In the second experimental evolution system, a mathematical model was developed to investigate the role of adaptive mutations, in the tetracycline inactivation enzyme TetX2, on antibiotic resistance to minocycline (MCN). Growth rates measurements, enzyme kinetics, and flux balance equations were used to develop a model to predict the effect on growth rates of TetX2 and seven adaptive TetX2 variants at different MCN concentrations. Population histogram measurements for the experimental evolution study were measured using a high throughput Illumina sequencing method (FREQ-SEQ). We found that the model was able to accurately predict the fitness outcomes for the wild type and the seven single mutants of TetX2 that were originally isolated, as well as for a double mutant that was not used in the development of the original model. The mathematical model accurately predicts that the two mutants TetX2T280A and TetX2N371I provide the largest fitness benefits, in agreement with the results of in vitro experiments on adaptation to MCN. The model was also able to accurately predict enzyme parameters from growth rates values, with a specific emphasis on predicting the ratio of Vmax/KM(MCN). The model allows us to make predictions about the fitness benefits of physicochemical changes to enzymes, and can be used as a high throughput method for determining enzyme kinetic parameters without requiring protein purification.
Understanding how physicochemical changes of enzymes relate to phenotypic changes, and ultimately to fitness, requires knowledge of both the molecular basis for determining enzyme properties, and how selection acts on fitness differences to determine evolutionary outcomes.
This research provides direct links between physicochemical changes and adaptive phenotypes, as well providing observations of how adaptive landscapes and fitness changes affect evolutionary outcomes
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