Abstract: The obtaining of fatigue models of asphalt mixtures, are part of the procedures of advanced characterization of the material and are used for the design of pavements. However, there are several approaches to analysis and failure criteria that can be used. These approaches and criteria may not produce the same models of fatigue, resulting in different thicknesses of the asphalt surface in the pavement structure. This study presents the results of the influence of two approaches of analysis (phenomenological and accumulated dissipated energy) and two criteria of rupture (conventional and Pronk & Hopman) in obtaining fatigue models of the asphalt mixture, and its repercussion in the estimation of useful life of the asphalt surface in the pavement structure. The results show that the phenomenological approach is more conservative than the accumulated dissipated energy, as well as the Pronk & Hopman criterion in relation to the conventional criterion, that is, the type of approach and the criterion of rupture adopted will directly affect the final thickness of the projected asphalt surface.

Resumen: Obtener los modelos de fatiga de mezclas asfálticas es parte de los procedimientos de caracterización avanzada de este material y los mismos son utilizados para el diseño del pavimento. No obstante, existen diversos enfoques de análisis y criterios de rotura que pueden ser utilizados. Estos enfoques y criterios pueden producir modelos de fatiga diferentes y, en consecuencia, capas asfálticas con espesores diferentes en la estructura del pavimento. Este estudio presenta los resultados de la influencia de dos enfoques de análisis, fenomenológico y de energía disipada acumulada, y dos criterios de rotura, convencional y de Pronk & Hopman, en la obtención de los modelos de fatiga de la mezcla asfáltica, y su repercusión en la estimación de la vida útil de la capa en la estructura del pavimento. Los resultados muestran que el enfoque fenomenológico es más conservador que el de energía disipada acumulada, como también lo es el criterio de Pronk & Hopman en relación al criterio convencional, es decir, el tipo de enfoque y el criterio de rotura adoptado repercutirán directamente en el espesor final de la capa diseñada.

Health is currently recognized as lying in the individual process rooted in genes, personal habits, the social model and the understanding of the ideological standpoint from which it is viewed. The aim of this study was to validate the Early Childhood Oral Health Impact Scale (ECOHIS) for use in Latin American communities, in order to demonstrate its efficacy for determining the impact of dental condition on children under 5 years of age and their families. The ECOHIS explores two domains: impact on children (9 questions) and on families (4 questions). Validation in Spanish was done in four stages. Stage I included translation and back-translation of the questionnaire (English-Spanish-English). Stage II was a pilot test on families in Venezuela to test stability (test-retest) and make semantic adjustments. Stage III included validation of the questionnaire applied to a Venezuelan sample (n=50) and two Argentine samples (A and B, made up of families with and without social risk, respectively; n=95), and consisted of statistical analysis to check the questionnaire's internal consistency and discriminant capacity. In the final stage, parents were given feedback on the results and significance of each domain in the questionnaire. From the results of this study it may be concluded that the Spanish version of the ECOHIS was reliable and valid for administering to populations with homogeneous social risk, and that parents without social risk factors (AC/B) have significantly greater perception of the impact of oral health on the family's quality of life. The trends recorded suggest that (a) larger samples should be used, including variables for diagnosing social vulnerability or general risk, (b) the association with dental condition should be established by applying indicators to discriminate distinct cut-off points in the dental caries process and (c) it should be ascertained whether there are changes in perception of the impact on quality of life before and after dental treatments, including impact on general health condition.

En la actualidad se reconoce que la salud esta en el proceso individual enraizado en los genes, los habitos personalisimos, el modelo social y la comprension de la ideologia de la cual depende en realidad el angulo desde el cual se la examina. El objetivo de este estudio fue validar el Early Childhood Oral Health Impact Scale (ECOHIS) para su aplicacion en comunidades latinoamericanas, a fin de demostrar su eficacia para determinar el impacto que el estado dentario produce sobre los ninos menores de 5 anos y su familia. El ECOHIS explora dos dominios: el impacto sobre el nino (9 preguntas) y sobre la familia (4 preguntas). Para la validacion en el idioma espanol se desarrollaron cuatro etapas. La etapa I: incluyo la traduccion reversa del cuestionario (inglés-espanol.ingles). La etapa II consistio en la prueba piloto realizada en familias venezolanas para comprobar la estabilidad (test-retest) y realizar el ajuste semantico. La etapa III incluyo la validacion del cuestionario aplicado en una muestra venezolana (n=50) y en dos muestras argentinas (AC/A y AC/B, constituidas por familias con y sin riesgo social, respectivamente; n=95), realizándose el analisis estadistico para comprobar la consistencia interna y la capacidad de discriminacion del cuestionario. En la ultima etapa se realizo la devolucion de la informacion a los padres acerca de los resultados y del significado de cada uno de los dominios del cuestionario. Los resultados obtenidos en el presente estudio permiten concluir que la version en espanol del ECOHIS resulto confiable y valida para su aplicacion en poblaciones con riesgo social homogeneo y que los padres sin factores de riesgo social (AC/B) muestran una percepcion significativamente mayor del impacto que el estado bucodental determina sobre la calidad de vida de la familia. Las tendencias registradas permiten recomendar la conveniencia de (a) ampliar el tamano de las muestras aplicadas en este estudio, incorporando variables que instalen el diagnostico de factores de vulnerabilidad social o de riesgo generales (b) establecer la asociacion existente con el estado dentario empleando indicadores que permitan discriminar puntos de corte diferenciados en el proceso de caries dental y (c) estudiar la existencia de cambios en la percepcion del impacto sobre la calidad de vida antes y despues de los tratamientos odontologicos incluyendo el impacto sobre el estado de salud general.

Water is a vehicle for disseminating human and veterinary toxoplasmosis due to oocyst contamination. Several outbreaks of toxoplasmosis throughout the world have been related to contaminated drinking water. We have developed a method for the detection of Toxoplasma gondii oocysts in water and we propose a strategy for the detection of multiple waterborne parasites, including Cryptosporidium spp. and Giardia. Water samples were filtered to recover Toxoplasma oocysts and, after the detection of Cryptosporidium oocysts and Giardia cysts by immunofluorescence, as recommended by French norm procedure NF T 90-455, the samples were purified on a sucrose density gradient. Detection of Toxoplasma was based on PCR amplification and mouse inoculation to determine the presence and infectivity of recovered oocysts. After experimental seeding assays, we determined that the PCR assay was more sensitive than the bioassay. This strategy was then applied to 482 environmental water samples collected since 2001. We detected Toxoplasma DNA in 37 environmental samples (7.7%), including public drinking water; however, none of them were positive by bioassay. This strategy efficiently detects Toxoplasma oocysts in water and may be suitable as a public health sentinel method. Alternative methods can be used in conjunction with this one to determine the infectivity of parasites that were detected by molecular methods.