Abstract Accurate determination of the prevalence of erosive tooth wear (ETW) and associated risk factors in adolescents can inform clinical management guidelines. The aim of this analytical cross-sectional study was to estimate the prevalence, severity, and risk factors of ETW in adolescents aged 12–15 years in the municipality of Usaquén in Bogotá, Colombia. Two calibrated examiners clinically assessed ETW using Basic Erosive Wear Examination (BEWE) Index (range: 0–3). All tooth surfaces (excluding proximal) were scored to allow estimation of the Highest (0–3) and Total BEWE (sum of Highest BEWE score per sextant: 0–18) scores per patient. Sociodemographic characteristics, ETW risk factors, and caries severity (ICDAS-epi-merged) were evaluated, and their association with the presence of ETW (indicated by a Highest BEWE score of 2–3) was examined using preliminary analyses and logistic regression models. The study sample included 454 adolescents (mean age: 13.5±1.1 years; female: 61.7%), and the prevalence of ETW was 71.6%. The majority of participants exhibited a Highest BEWE score of 3 (58.0%) and a Total BEWE score ≤8 (84.3%). The preliminary analysis showed an association between the presence of ETW and age, caries, and brushing teeth before eating (p-value < 0.05). Risk factors for ETW included always brushing teeth before eating [adjusted Prevalence Ratio (PRa) 1.31, p-value=0.014], presence of extensive carious lesions (PRa 1.23, p-value = 0.024), male gender (PRa 1.14, p-value = 0.028), and age > 14 years (PRa 1.17, p-value = 0.009). Although ETW was highly prevalent, most Colombian adolescents exhibited low Total BEWE scores. ETW was associated with frequent fruit intake, age, toothbrushing habits, caries lesions, and sex. (ETW guidelines crosssectional cross sectional 1215 12 15 12–1 Bogotá Colombia (BEWE range (range 0–3. 03 0–3 . 0 0–3) excluding proximal (0–3 sum sextant 0–18 018 18 patient characteristics ICDASepimerged ICDAS epi merged (ICDAS-epi-merged evaluated indicated 2–3 23 2 models 45 mean 13511 13 5 1 13.5±1. female 61.7%, 617 61.7% , 61 7 61.7%) 716 71 6 71.6% 58.0% 580 58 (58.0% 8 ≤ 84.3%. 843 84.3% 84 (84.3%) pvalue p value 0.05. 005 0.05 05 0.05) adjusted PRa 131 31 1.31 pvalue=0.014, pvalue0014 value=0.014 014 p-value=0.014] 123 1.23 0.024, 0024 0.024 024 0.024) 114 1.14 0.028, 0028 0.028 028 0.028) 117 17 1.17 0.009. 0009 0.009 009 0.009) prevalent intake habits sex 121 12– 0– (0– 0–1 01 2– 4 1351 13.5±1 61.7 71.6 58.0 (58.0 84.3 (84.3% 00 0.0 1.3 pvalue=0.014 pvalue001 value0014 value=0.01 p-value=0.014 1.2 002 0.02 02 11 1.1 000 0.00 (0 135 13.5± 61. 71. 58. (58. 84. (84.3 0. 1. pvalue=0.01 pvalue00 value001 value=0.0 p-value=0.01 ( 13.5 (58 (84. pvalue=0.0 pvalue0 value00 value=0. p-value=0.0 13. (5 (84 pvalue=0. value0 value=0 p-value=0. (8 pvalue=0 value= p-value=0 pvalue= p-value=

Abstract The inequality in Colombia has been widely documented from different perspectives, but little is known about inequalities in the urban-rural context. This paper studies urban-rural inequality in the labor market using a Blinder-Oaxaca decomposition for labor income and characterization of rural and urban labor markets. We find that about 60 % of the urban-rural earnings gap is explained by observed worker factors such as educational level and age; the remaining 40 % is due to unobserved characteristics such as employer preferences, worker’s ability, etc. We identify three rural labor market conditions that explain and promote the urban-rural labor income gap: i) low female labor participation and high unemployment rates compared to their urban counterparts; ii) significantly higher labor informality that in urban areas; and iii) high incidence of child labor.

Resumen La desigualdad en Colombia ha sido ampliamente documentada desde distintas ópticas, pero poco se sabe sobre las desigualdades en el contexto urbano-rural. Este trabajo estudia la desigualdad urbano-rural en el mercado laboral mediante el uso de una descomposición Blinder-Oaxaca para los ingresos laborales y una caracterización de los mercados laborales rurales y urbanos. Encontramos que cerca del 60 % de la brecha en ingresos laborales se explica por factores observados de los trabajadores como el nivel educativo y edad; el restante 40 % se debe a características no observadas, como preferencias de los empleadores, habilidad de los trabajadores, etc. Identificamos tres condiciones del mercado laboral rural que explican y promueven la brecha en ingresos laborales urbano-rural: i) baja participación laboral femenina y altas tasas de desempleo en comparación con sus contrapartes urbanas; ii) informalidad laboral significativamente más alta que en las zonas urbanas; y iii) mayor incidencia del trabajo infantil.

Resumen Introducción y objetivo: la severidad de la fluorosis dental refleja exposición a fluoruros durante el desarrollo del esmalte. Recientemente se han reportado asociaciones entre la exposición prenatal y postnatal a fluoruros y efectos negativos en el neurodesarrollo. El objetivo de este estudio fue describir y comparar la severidad y el patrón de distribución de la fluorosis en las denticiones primaria y permanente, como base para discutir la temporalidad de la exposición en niños viviendo en áreas endémicas en el departamento del Huila. Materiales y métodos: odontólogos entrenados diagnosticaron fluorosis en 840 niños (preescolares y escolares) de cuatro municipios usando el índice de Thylstrup & Fejerskov. Para estimar la prevalencia de las diferentes severidades, cada niño se clasifico de acuerdo con la severidad más alta en boca. La distribución de la prevalencia de severidades por grupo etario y tipo de dentición se reportan como tasas de prevalencia (%). Resultados: la prevalencia en preescolares y escolares fue de 97.2% y 99.9%, respectivamente y la fluorosis moderada la más prevalente (75.6% y 63.5%, respectivamente). En ambas denticiones, la fluorosis leve fue más prevalente en los dientes anteriores que en posteriores. Las severidades moderada y severa tuvieron mayor prevalencia en dientes posteriores que en anteriores. Conclusiones: el patrón de distribución de la severidad de la fluorosis sugiere exposición prenatal y postnatal a fluoruros, por encima de los niveles recomendados. Este estudio resalta la importancia de la alidación de la fluorosis del dental como un potencial biomarcador histórico de exposición a luoruros en momentos críticos para el neurodesarrollo.

Abstract Introduction and objective: dental fluorosis severity reflects fluoride exposure during dental enamel development. Recently, prenatal and postnatal exposure to fluoride has been associated with negative neurodevelopmental outcomes. The aim of this study was to describe and compare the severity and distribution pattern of dental fluorosis in the primary and permanent dentition, as a basis to discuss the timing and extent of fluoride exposure of children living in endemic areas of fluorosis in the department of Huila. Materials and methods: 840 children (preschoolers and schoolchildren) from four municipalities of the Huila Department were examined by trained dentists for dental fluorosis using the Thylstrup & Fejerskov Index. To estimate the prevalence of severities of fluorosis, each child was classified according to the most severe score. The distribution of the prevalence of enamel fluorosis severity by age-group and type of dentition were reported as prevalence rates (%). Results: Prevalence of dental fluorosis in preschoolers was of 97.2% and in schoolers of 99.9%. For both preschoolers and schoolers moderate fluorosis was the most prevalent (75.6% and 63.5%, respectively). For both primary and permanent teeth, mild fluorosis was more prevalent in anterior teeth than in posterior teeth. Moderate and severe fluorosis were more prevalent in posterior teeth than in anterior teeth. Conclusions: the distribution pattern of the severity of dental fluorosis suggests both prenatal and postnatal exposure to fluoride above recommended levels. This study raises the importance of the validation of dental fluorosis as a potential historical biomarker of fluoride exposure at moments that are critical for neurodevelopment.

Resumo Introdução e objetivo: a severidade da fluorose dentária reflete a exposição a fluoretos durante o desenvolvimento do esmalte. Recentemente, associações entre a exposição pré-natal e pós-natal ao fluoretos e efeitos negativos no desenvolvimento neurológico foram relatadas. O objetivo deste estudo é descrever e comparar o padrão de severidade e distribuição da fluorose na dentição decídua e permanente, como intuito para a discussão sobre a temporalidade da exposição em crianças moradoras em áreas endêmicas de fluorose no departamento de Huila, Colômbia. Materiais e métodos: Cirurgiões-dentistas treinados diagnosticaram fluorose em 840 crianças (pré-escolares e escolares) de quatro municípios, utilizando o índice de Thylstrup & Fejerskov. Para estimar a prevalência dos diferentes estágios de severidade, cada criança foi classificada de acordo com o escore mais severo da boca. A distribuição da prevalência de fluorose nos diferentes estágios de severidade por faixa etária e tipo de dentição é apresentada como taxa de prevalência (%). Resultados: a prevalência de fluorose em pré-escolares foi de 97,2% e em escolares de 99,9%. Fluorose moderada foi a mais prevalente (75,6% e 63,5%, respectivamente). Em ambas as dentições, a fluorose leve foi mais prevalente nos dentes anteriores do que nos posteriores. Porém, tanto fluorose moderada como severa foram mais prevalentes nos dentes posteriores do que nos anteriores. Conclusões: o padrão de distribuição da severidade da fluorose sugere uma exposição pré- e pós-natal a fluoretos acima de níveis recomendados. Este estudo salienta a importância da validação da fluorose dentária como um potencial biomarcador histórico da exposição ao fluoretos durante momentos críticos para o neurodesenvolvimento.

RESUMEN Antecedentes: en Colombia el consumo de mango verde fresco (también conocido como mango “biche”) es popular, y se consume con zumo de limón, sal y miel. Sin embargo, su alto contenido de humedad y alta actividad de agua hace que el mango sea un fruto altamente perecedero, por lo que requiere alternativas de procesamiento. La deshidratación osmótica (OD) es una interesante alternative para la conservación de mango. En OD se utilizan tradicionalmente soluciones binarias (solute + agua) y soluciones ternarias (2 solutos + agua), sin embargo, puede removerse mayor cantidad de agua utilizando soluciones ternarias, las cuales permiten mejorar las propiedades organolépticas de productos deshidratados. Objetivos: evaluar las cinéticas de pérdida de agua (WL), ganancia de solutos (SG), reducción de peso (WR), actividad de agua (a w ) y volumen (coeficiente de encogimiento, SC) en muestras de mango verde (Mangifera indica L. Filipino variety) deshidratadas osmóticamente (OD). Adicionalmente, calcular la difusividad (D ef ) del agua y de solutos, en los distintos tratamientos. Métodos: se usaron mangos verdes con escala de madurez cero. En la OD se usaron soluciones ternarias compuestas por sacarosa (40%) y NaCl al 3, 6 y 9%. Como tratamiento control se usó una solución binaria de sacarosa más agua. En el proceso osmótico las muestras fueron tomadas a diferentes tiempos de OD (15, 30, 60, 90, 180, 240, and 300 min). Resultados: Los resultados mostraron que al incrementar la concentración de NaCl, las WL fueron más rápidas, la a w y el SC fueron menores y las D ef de agua y solutos mayores. Las muestras deshidratadas con la máxima concentración de solutos (40-9%), alcanzaron las mayores WL, SG y WR con valores de 59.82, 13.10 y 46.68%, respectivamente. Los coeficientes D efw and D efs mostraron orden de magnitude de 10-10 m2/s, valor que se encuentra en el intervalo para alimentos deshidratados. Conclusiones: esta investigación mostró que soluciones binarias (sacarosa + agua) y ternarias (NaCl + sacarosa + agua) son adecuadas para deshidratar mango verde, sin embargo, las soluciones ternarias fueron más efectivas.

ABSTRACT Background: in Colombian the consumption of fresh green mango (also known as mango “biche”) is quite popular, and is consumed with lemon juice, salt, and honey. However, its high humidity content and high water activity makes of mango a highly perishable fruit, thus requiring processing alternatives. Osmotic dehydration (OD) is an interesting alternative for the conservation of mango. In OD, binary solutions (Solute + water) and ternary solutions (2 Solutes + water), have been traditionally used, however, more water removal can be achieved using ternary solutions, which leads to the improved organoleptic properties of dehydrated products Objetives: to evaluate the kinetic water loss (WL), solutes gain (SG), weight reduction (WR), water activity (a w ), and volume (Shrinking Coefficient, SC)) in green mango (Mangifera indica L. Filipino variety) osmotically dehydrated (OD). Additionally, to calculate water and solutes diffusivity (D ef ) for each treatment. Methods: green mango samples, with maturity scale zero, were used. Ternary solutions of sucrose at 40% and NaCl at 3, 6 and 9% were used for OD. The binary solution of sucrose with water as control treatment, was used. In the osmotic process samples were taken out at different times of OD (15, 30, 60, 90, 180, 240, and 300 min). Results: the findings show that at a higher concentration of NaCl, the dehydration kinetics was more rapid, a w and SC were smaller and, water and solutes D ef were higher. The samples dehydrated with the greatest solutes concentration (40 - 9%) reached the highest WL, SG, and WR with 89.52, 13.10, and 46.68%, respectively. Coefficients D efw and D efs showed a magnitude order of 10-10 m2/s, which is within the interval of dehydrated foods. Conclusions: this research showed that binary (sucrose + water) and ternary (NaCl + sucrose + water) solutions, are suitable for dehydrating green mango, however, the ternary solutions were more effective.

Few-layer graphene was grown by Chemical Vapor Deposition on a CuO thin film pre-deposited by sputtering on SiO2/Si substrates using acetylene as the carbon source. After evaporation of metal, graphene lies directly in contact with the SiO2 dielectric layer. Raman spectroscopy was used to confirm the presence of a single and/or few-layers of graphene. This procedure does not requiring any post processing to transfer the thin film onto a dielectric substrate or the use of ultra-high vacuum during synthesis.

Introducción. El glifosato es un herbicida de amplio espectro, no selectivo, utilizado para eliminar malezas indeseables en ambientes agrícolas y forestales. La acción herbicida corresponde a la inhibición de la biosíntesis de aminoácidos aromáticos en las plantas. Al no ser este mecanismo compartido por los seres humanos es considerado como de bajo riesgo para la salud de los mismos. Sin embargo, investigaciones recientes indican que puede alterar otros procesos celulares en animales lo que puede presentar un factor de riesgo a nivel ambiental y de salud en las zonas donde se emplea este herbicida. Objetivo. El objetivo del presente estudio fue evaluar la citotoxicidad y la genotoxicidad del glifosato en células humanas normales (GM38) y en células humanas de fibrosarcoma (HT1080). Materiales y métodos. La citotoxicidad aguda y crónica se determinó al exponer las células en cultivo a diferentes concentraciones de glifosato, y se analizó la viabilidad celular con cristal violeta y colorante de exclusión azul de tripano, respectivamente. La genotoxicidad se determinó por medio del ensayo del cometa y los datos se analizaron usando la prueba de Dunnet. Resultados. En la citotoxicidad crónica las células GM38 y las HT1080 presentaron un efecto dependiente de la dosis después del tratamiento con glifosato en concentraciones de 5,2 a 8,5 mM y 0,9 a 3,0 mM, respectivamente. En la citotoxicidad aguda, las células GM38 y las HT1080 expuestas a un rango de concentraciones de 4,0 a 7,0 mM, 4,5 a 5,75 mM y 4,0 a 7,0 mM, respectivamente, presentaron una viabilidad mayor al 80%. Se evidenció daño en el AND después del tratamiento con glifosato en concentraciones de 4,0 a 6,5 mM para las células GM38 y de 4,75 a 5,75 mM para las células HT1080. Conclusiones. Se sugiere que el mecanismo de acción del glifosato no se limita únicamente a las plantas sino que puede alterar la estructura del ADN en otros tipos de células como son las de los mamíferos.

Introduction. Glyphosate is a broad-spectrum non-selective herbicide, used to eliminate unwanted weeds in agricultural and forest settings. Herbicide action is achieved through inhibition of aromatic amino acid biosynthesis in plant cells. Since this is not a conserved mechanism between human and plant cells, glyphosate is considered to be a low health risk substance for humans. However, the occurrence of possible harmful side effects of glyphosate use is not well documented and controversial. Toxicity and genotoxicity studies indicate that glyphosate is not harmful, although several investigations suggest that it can alter various cellular processes in animals. Therfore this has potential as a health and environmental risk factor in areas where glyphosate is widely used. Objectives. The present study evaluated glyphosate cytotoxic and genotoxic effects in normal human cells (GM38) and human fibrosarcoma (HT1080) cells. Materials and methods. Acute and chronic cytotoxicity were determined through the exposure of cultured cells to graded concentrations of glyphosate, and cell viability analysis was performed with crystal violet and Trypan blue staining. Genotoxicity was determined using the comet assay and data significance was evaluated with Dunnet’s test. Results. For chronic cytotoxicity a dose-dependent effect was observed in both GM38 and HT1080 cells after treatment with 5.2-8.5 mM and 0.9-3.0 mM glyphosate, respectively. In the acute cytotoxicity study, GM38 cells exposed to 4.0-7.0 mM glyphosate and HT1080 cells exposed to 4.5-5.8 mM glyphosate, had cell viability counts higher than 80%. Genotoxic effects were evidenced in GM38 cells at glyphosate concentrations of 4.0-6.5 mM and in HT1080 cells at glyphosate concentrations of 4.75 -5.75 mM. Conclusions. The levels of cytotoxicity and genotoxicity of glyphosate occurring in mammalian cells suggested that its mechanism of action is not limited to plant cells.