Do Colombian students underestimate higher education returns?

We analyze the determinants of subjective returns of higher education in Colombia. The information on expectations has been collected in categories, motivating the use of interval regression and an ordered probit approaches for modeling the relationship between beliefs and measures of ability, conditioning on individual, school and regional covariates. The results suggest that there are considerable differences in the size of the expected returns according to some population groups and a strong dominance of college against technical education. Gender gaps disappear in college education but it is found that girls tend to believe that professional wages are more concentrated into higher income categories than boys. Finally, it seems that Colombian students overestimate the pecuniary returns to education.

Caracterización epidemiológica de la artritis idiopática juvenil y refractariedad a dmard en una institución en Bogotá

La artritis idiopática juvenil (AIJ) es la enfermedad reumatológica crónica más común de la infancia con repercusiones importantes en la calidad de vida del paciente y su familia; las alteraciones físicas presentadas pueden ocasionar ausentismo escolar. Los tratamientos de uso crónico utilizados hacen que la adherencia al mismo en la población infantil y adolescente sea todo un reto. A esto se adiciona la refractariedad a DMARDs (Disease – Modifying – Antirheumatic – Drugs) que conlleva al inicio de terapia biológica y a cambios en el pronóstico de la enfermedad. Materiales y métodos: Estudio observacional retrospectivo mediante la revisión de las historias clínicas de pacientes con diagnóstico de artritis idiopática juvenil que consultaron a la Fundación Cardioinfantil desde enero del 2008 a septiembre de 2015. Se obtuvieron datos como edad, sexo, edad de diagnóstico, manejo actual, remisión, seguimiento, tratamiento, cambios realizados en el mismo y refractariedad a DMARD. Resultados: De 108 registros clínicos evaluados, 90 cumplieron los criterios de elegibilidad. Se diagnosticó con mayor frecuencia en el sexo femenino con un 57.8%, media de edad de 7.88 años. El subtipo poliarticular con Factor Reumatoideo negativo se presentó con una frecuencia con 31,1 %. El tiempo transcurrido entre el inicio de la sintomatología en meses, previo a realizar el diagnóstico, osciló entre 1 y 60 meses con una media de 10,6 meses. Se usaron con mayor frecuencia: AINES (61,1%), metotrexate (47,8%) y corticoides (42,2%). De los 90 pacientes, solo un 11.1% de la población presentó complicaciones, siendo la más frecuente la obesidad en un 3,3 % y la menos frecuente la uveítis con un 1,1%. Discusión: Es importante el entendimiento de la Artritis idiopática juvenil como una entidad de carácter sistémica, lo cual hace necesario el conocimiento de la epidemiología para establecer estrategias de manejo y seguimiento adecuadas. El género femenino continúa siendo afectado en mayor porcentaje. Se observaron leves cambios respecto al subtipo de mayor frecuencia comparado con estudios previos. Se necesitan más estudios de caracterización epidemiológica en la población Colombiana para realización de políticas de salud pública

La pelota no se mancha: Un estudio histórico sobre el desarrollo y la política en FIFA

Esta investigación se centra en la Fédération Internationale de Football Association (FIFA) como organización política. Intenta responder dos interrogantes primordiales: 1) ¿cómo la FIFA ha constituido el poder que tiene actualmente y, así, hacerse del monopolio indiscutido del fútbol? Y 2) ¿cómo ha cambiado en el tiempo la política interna de FIFA y su vínculo con la política internacional? Para lograr esto, se realiza un estudio histórico, basado principalmente en documentos, que intenta caracterizar y analizar los cambios de la organización en el tiempo. Se enfatizan las últimas dos presidencias de FIFA, de João Havelange y Joseph Blatter, como casos de estudio.

Pulsioximetría de pacientes en hemodiálisis, de la unidad de terapia renal – fundación cardioinfantil, análisis para establecer recomendaciones

Introducción. En Colombia, el 80% de los pacientes con enfermedad renal crónica en hemodiálisis tienen fístula arteriovenosa periférica (FAV) que asegura el flujo de sangre durante la hemodiálisis (1), la variabilidad en el flujo de sangre en el brazo de la FAV hacia la parte distal, puede afectar la lectura de la oximetría de pulso (SpO2) (2), llevando a la toma de decisiones equivocadas por el personal de salud. El objetivo de este estudio es aclarar si existe diferencia entre la SpO2 del brazo de la FAV y el brazo contralateral. Materiales y métodos. Se realizó un estudio de correlación entre los valores de SpO2 del brazo con FAV contra el brazo sin FAV, de 40 pacientes que asistieron a hemodiálisis. La recolección de los datos se llevó a cabo, con un formato que incluyó el resultado de la pulsioximetria y variables asociadas, antes, durante y después de la hemodiálisis. Se comparó la mediana de los deltas de las diferencias con pruebas estadísticas T Student – Mann Whitney, aceptando un valor significativo de p < 0,05. Resultados. No se encontraron diferencias estadísticamente significativas de la SpO2 entre el brazo con FAV y el brazo sin FAV, antes, durante y después de la diálisis, sin embargo si se apreció una correlación positiva estadísticamente significativa. Conclusiones. Se encontró correlación positiva estadísticamente significativa, donde no hubo diferencias en el resultado la pulsioximetría entre el brazo con FAV y brazo sin FAV, por lo tanto es válido tomar la pulsioximetría en cualquiera de los brazos.

Fronts from complex two-dimensional dispersal kernels: theory and application to Reid's paradox

Bimodal dispersal probability distributions with characteristic distances differing by several orders of magnitude have been derived and favorably compared to observations by Nathan [Nature (London) 418, 409 (2002)]. For such bimodal kernels, we show that two-dimensional molecular dynamics computer simulations are unable to yield accurate front speeds. Analytically, the usual continuous-space random walks (CSRWs) are applied to two dimensions. We also introduce discrete-space random walks and use them to check the CSRW results (because of the inefficiency of the numerical simulations). The physical results reported are shown to predict front speeds high enough to possibly explain Reid's paradox of rapid tree migration. We also show that, for a time-ordered evolution equation, fronts are always slower in two dimensions than in one dimension and that this difference is important both for unimodal and for bimodal kernels

Unitats litològiques d'interès per a la producció d'àrids a l'àrea del curs mitjà del riu Fluvià (la Garrotxa)

Pleistocene and Quaternary sediments adjacent to the medium course of the Fluvià river are a source of aggregate in the Garrotxa. Four lithological units can be used directly, or with a minimal processing as coarse aggregate. They have been mapped in detail at the 1:5.000 escale. The stratigraphic analysis have made possible the four units to be ordered in relation to their suitibility for usage as aggregate. From high to low relative quality they are: the basaltic flow, fluviatile deposits, plio-quaternary conglomerates, and glacis deposits

Educação ambiental na perspectiva da sustentabilidade no ambiente do projovem urbano

A preocupação central dessa pesquisa foi compreender se dá o ensino da Educação Ambiental na perspectiva da sustentabilidade, no cotidiano da sala de aula no Projovem Urbano na região metropolitana do Recife, Pernambuco, Brasil. A pesquisa foi desenvolvida com 110 alunos de ambos os sexos, de escolas públicas da RMR e matriculados no curso do Projovem e 10 professores que lecionam nesse projeto. Para isso aplicamos o questionário adaptado com os alunos e com os professores utilizamos uma entrevista semi-estruturada. Na realização da Análise dos dados quantitativos utilizamos o Software Package for Social Sciences – SPSS versão 18.0 e na elaboração dos gráficos o Software Microsoft Excel 2007; enquanto a análise dos dados qualitativos foi orientada pela Análise do Discurso – AD. Os resultados demonstram que apesar de A Educação Ambiental e a Sustentabilidade serem um tema recente, já está fazendo parte das salas de aulas objetivando a formação de cidadãos conscientes das suas atitudes para com o meio ambiente. Podemos verificar que ainda faz necessário o investimento cada vez mais na educação para que possamos formar cada vez mais cidadãos a fim de mantermos uma relação harmoniosa entre o homem e a natureza, possibilitando com isso um ambiente sustentável para a presente e futuras gerações. Com base na pesquisa, podemos verificar que ainda é pouco o investimento em palestras, reuniões e eventos voltados para os professores, para que os mesmo possuam mais conhecimento para aplicar de melhor forma de acordo com a necessidade da comunidade em que a escola está inserida com o intuito de promover sempre a EA e a sustentabilidade, além de proporcionar um melhor ambiente para a comunidade, com a minimização dos problemas enfrentados pelos mesmos, como é a questão do lixo, que não é apenas uma questão ambiental, mas também de saúde, já que o mesmo pode transmitir várias doenças através dos insetos, roedores e outros.

Katalizatory złotowo-miedziowe na nośnikach cerowych, cyrkonowych i cerowo-cyrkonowych – preparatyka, charakterystyka i zastosowanie w procesach utleniania

Wydział Chemii

En busca del mural de Camilo Egas en la Feria Mundial de 1939 (Debates)

El artículo aborda el mural que el artista plástico ecuatoriano Camilo Egas preparó para el pabellón del Ecuador en la Feria Mundial de Nueva York, de 1939. Se revisan los detalles relacionados con la confección de la obra encargada por el Gobierno ecuatoriano y las reacciones que suscitó entre los asistentes a la exposición, funcionarios diplomáticos ecuatorianos y otras personalidades gubernamentales. Además, se describen algunos aspectos relacionados con su abandono, una vez concluida la exhibición y con la tarea de identificación de la documentación que testimonia el caso.

Adsorption, orientation and thermal decomposition of copper(II) hexafluoroacetylacetonate on rutile TiO2(110)

We have investigated the adsorption and thermal decomposition of copper hexafluoroacetylacetonate (Cu-11(hfaC)(2)) on single crystal rutile TiO2(110). Low energy electron diffraction shows that room temperature saturation coverage of the Cu-II(hfac)(2) adsorbate forms an ordered (2 x 1) over-layer. X-ray and ultra-violet photoemission spectroscopy of the saturated surface were recorded as the sample was annealed in a sequential manner to reveal decomposition pathways. The results show that the molecule dissociatively adsorbs by detachment of one of the two ligands to form hfac and Cu-1(hfac) which chemisorb to the substrate at 298 K. These ligands only begin to decompose once the surface temperature exceeds 473 K where Cu core level shifts indicate metallisation. This reduction from Cu(I) to Cu(0) takes place in the absence of an external reducing agent and without disproportionation and is accompanied by the onset of decomposition of the hfac ligands. Finally, C K-edge near edge X-ray absorption fine structure experiments indicate that both the ligands adsorb aligned in the < 001 > direction and we propose a model in which the hfac ligands adsorb on the 5-fold coordinated Ti atoms and the Cu-1(hfac) moiety attaches to the bridging O atoms in a square planar geometry. The calculated tilt angle for these combined geometries is approximately 10 degrees to the surface normal.

Periodic Reordering

For many networks in nature, science and technology, it is possible to order the nodes so that most links are short-range, connecting near-neighbours, and relatively few long-range links, or shortcuts, are present. Given a network as a set of observed links (interactions), the task of finding an ordering of the nodes that reveals such a range-dependent structure is closely related to some sparse matrix reordering problems arising in scientific computation. The spectral, or Fiedler vector, approach for sparse matrix reordering has successfully been applied to biological data sets, revealing useful structures and subpatterns. In this work we argue that a periodic analogue of the standard reordering task is also highly relevant. Here, rather than encouraging nonzeros only to lie close to the diagonal of a suitably ordered adjacency matrix, we also allow them to inhabit the off-diagonal corners. Indeed, for the classic small-world model of Watts & Strogatz (1998, Collective dynamics of ‘small-world’ networks. Nature, 393, 440–442) this type of periodic structure is inherent. We therefore devise and test a new spectral algorithm for periodic reordering. By generalizing the range-dependent random graph class of Grindrod (2002, Range-dependent random graphs and their application to modeling large small-world proteome datasets. Phys. Rev. E, 66, 066702-1–066702-7) to the periodic case, we can also construct a computable likelihood ratio that suggests whether a given network is inherently linear or periodic. Tests on synthetic data show that the new algorithm can detect periodic structure, even in the presence of noise. Further experiments on real biological data sets then show that some networks are better regarded as periodic than linear. Hence, we find both qualitative (reordered networks plots) and quantitative (likelihood ratios) evidence of periodicity in biological networks.

Characteristics of silica-rich pedofeatures in a buried paleosol

Whitish and whitish-light brown milky-like textural pedofeatures and impregnations were found in the voids and the matrix of buried paleosols older than 2.7 million years in a site in Sardinia, Italy. The pedofeatures were described and analysed using micromorphology, X-ray diffraction and microprobe techniques, and their spatial distribution correlated with field evidence. The suite of analyses showed that the main components of the pedofeatures were more or less ordered silica phases. As well as forming a matrix cement, these pedofeatures also occurred as coatings and infillings in pores. Significant amounts of alumina and, less, Mg, Ca and Fe were also present in the pedofeatures, possibly in the form of silicate coatings and inclusions/impurities, or alumino-silicates of the adjacent soil matrix. A number of hypotheses are drawn on the possible mechanisms of formation of these silica-rich pedofeatures, including the possibility of prolonged weathering of volcanic materials and the resulting formation of colloids and more or less ordered silica phases, with successive dehydration and progressive ordering of phases during the at least 2.5 million years. (C) 2003 Elsevier B.V. All rights reserved.

Characteristics of silica-rich pedofeatures in a buried paleosol

Whitish and whitish-light brown milky-like textural pedofeatures and impregnations were found in the voids and the matrix of buried paleosols older than 2.7 million years in a site in Sardinia, Italy. The pedofeatures were described and analysed using micromorphology, X-ray diffraction and microprobe techniques, and their spatial distribution correlated with field evidence. The suite of analyses showed that the main components of the pedofeatures were more or less ordered silica phases. As well as forming a matrix cement, these pedofeatures also occurred as coatings and infillings in pores. Significant amounts of alumina and, less, Mg, Ca and Fe were also present in the pedofeatures, possibly in the form of silicate coatings and inclusions/impurities, or alumino-silicates of the adjacent soil matrix. A number of hypotheses are drawn on the possible mechanisms of formation of these silica-rich pedofeatures, including the possibility of prolonged weathering of volcanic materials and the resulting formation of colloids and more or less ordered silica phases, with successive dehydration and progressive ordering of phases during the at least 2.5 million years. (C) 2003 Elsevier B.V. All rights reserved.

Chess endgame news

News that Bourzutschky confirms there is no sub-7-man pawnless zugzwang, and that Bourzutschky and Konoval are generating DTC EGTs with a new program. News also of Kristensen's work on EGTs using OBDDs, Ordered Binary Decision Diagrams.

Monte Carlo phase diagram for diblock copolymer melts

A partial phase diagram is constructed for diblock copolymer melts using lattice-based Monte Carlo simulations. This is done by locating the order-disorder transition (ODT) with the aid of a recently proposed order parameter and identifying the ordered phase over a wide range of copolymer compositions (0.2 <= f <= 0.8). Consistent with experiments, the disordered phase is found to exhibit direct first-order transitions to each of the ordered morphologies. This includes the spontaneous formation of a perforated-lamellar phase, which presumably forms in place of the gyroid morphology due to finite-size and/or nonequilibrium effects. Also included in our study is a detailed examination of disordered cylinder-forming (f=0.3) diblock copolymers, revealing a substantial degree of pretransitional chain stretching and short-range order that set in well before the ODT, as observed previously in analogous studies on lamellar-forming (f=0.5) molecules. (c) 2006 American Institute of Physics.