Aspectos zoonóticos de la toxoplasmosis sobre la salud pública en Colombia

Actualmente se conocen diferentes factores que tienen relación con enfermedades zoonóticas, como lo es la enfermedad producida por el protozoo Toxoplasma gondii, en animales de producción destinados al consumo humano y que afecta la salud pública en Colombia. Este parásito se transmite al humano principalmente por vía oral, es decir por la ingesta de alimentos contaminados producto del incumplimiento de la normatividad y buenas prácticas pecuarias tanto en granjas como en las plantas de beneficio de abasto. Así mismo se evidencia una prevalencia del 50% a 60% de mujeres embarazadas que presentan anticuerpos anti toxoplasma en el país, es por eso que se presenta una revisión bibliográfica sobre la toxoplasmosis y los aspectos zoonóticos sobre la salud pública en Colombia. Objetivo: Analizar información científica disponible sobre los aspectos zoonóticos de la toxoplasmosis y la forma de prevención por medio del cumplimiento de la normatividad y buenas prácticas existentes. Metodología: Se realizó una revisión sistemática de bibliografía científica teniendo en cuenta diferentes criterios de inclusión y palabras clave como buenas prácticas pecuarias, contaminación alimenticia, manipulación de alimentos, Toxoplasma gondii, zoonosis. Resultados: Mediante la revisión del tema sobre la toxoplasmosis en Colombia, la forma como genera un problema de salud pública y la relación de transmisión entre animales y humanos específicamente en la forma alimentaria, se recopiló información científica que da claridad sobre la relación zoonótica, dando a conocer que el 47% de la población presenta títulos de anticuerpos positivos para Toxoplasma gondii y la prevalencia de mujeres embarazadas que presentan anticuerpos anti toxoplasma en el país, el cual es de 50% a 60%. Conclusiones: Se logró evidenciar las diferentes falencias que se presentan en algunas granjas y plantas de beneficio con respecto al cumplimiento de la normatividad vigente, para así proponer

A metaphysical approach to holobiont individuality : Holobionts as emergent individuals

Holobionts are symbiotic assemblages composed by a host plus its microbiome. The status of holobionts as individuals has recently been a subject of continuous controversy, which has given rise to two main positions: on the one hand, holobiont advocates argue that holobionts are biological individuals; on the other, holobiont detractors argue that they are just mere chimeras or ecological communities, but not individuals. Both parties in the dispute develop their argu-ments from the framework of the philosophy of biology, in terms of what it takes for a ?conglomerate? to be considered an interesting individual from a biological point of view. However, the debates about holobiont individuality have important ontological implications that have remained vaguely explored from a metaphysical framework. The purpose of this paper is to cover that gap by presenting a meta-physical approach to holobionts individuality. Drawing upon a conception of natu-ral selection that puts the focus on the transgenerational recurrence of the traits and that supports the thesis that holobionts are units of selection, we argue that holobionts bear emergent traits and exert downward powers over the entities that compose them. In this vein, we argue, a reasonable argument can be made for conceiving holobionts as emergent biological individuals. Keywords: emergence, holobiont, symbiosis, microbiome, biological individuality, trait-recurrence

Modelling Biofilm Systems for Wastewater Treatment: Impact of Microscale Features on Global Modelling Results

Biofilm models are effective tools that allow the mathematical description of biofilm systems,the prediction of their removal performance as well as their conceptual exploration. Models have the advantage of being less resource and time consuming than laboratory experiments and being more flexible regarding the scenarios that can be analyzed. Due to the high complexity of biofilms, it is virtually impossible to develop a model that comprises all the phenomena occurring within the biofilm. Simplifications are considered a substantial part of the modelling process, and even the most comprehensive models developed until now make use of assumptions and simplifications. Nevertheless, the vast majority of models fulfill their purpose and are useful to both researches and practitioners (Wanner et al. 2006). The decision on which model is better for which modelling task relies on the data available, the level of understanding of the phenomena occurring in the system and the objective of the modelling task. In the specific case of biofilms, a trade-off between microscale features and global modelling results is often present. A more detailed description of the microscale features does not necessarily lead to more compelling modelling results, and occasionally it can compromise the identifiability and the determination of relevant parameters. However, neglecting microscale features can result in inaccurate representations of the system and thus the explanatory power of the model may be diminished. Depending on the system and its specific conditions, the modeler is presented with a dilemma: Which microscale features are worth including, which simplifications can be afforded and which simplifications are compulsory due to the lack of information. Two microscale features are of special interest in this work: microbial community composition and dimensionality. Three biofilm systems were used to explore the impact that these two microscale features have on the global modelling results and on the model’s explanatory power: A biologically active Granular Activated Carbon (bGAC) filter, a Moving Bed Bioreactor (MBBR) and a Membrane Aerated Biofilm Reactor (MABR). An individual publication is dedicated to each one of these systems. These systems were used to showcase alternative modelling approaches and to illustrate the effect of choosing simple or more complex descriptions of the microscale features of interest. The first and second publication, P1 and P2 respectively, focus on the microbial community composition. Publication P1 deals with DOC removal from WWTP effluents in a bGAC-filter. Within the filter, DOC is removed by simultaneous adsorption and biodegradation, therefore a suitable model should include both mechanisms. It proposes a model that integrates a traditional one-dimensional biofilm model with the ideal adsorbed solution theory that can be applied within the activated sludge model framework. A simplified microbial community composed solely composed of aerobic heterotrophic bacteria is selected. The developed model is able to describe the DOC breakthrough curves at different empty bed contact times and it also shows the relative contribution of biodegradation and adsorption to the total DOC removal. Publication P2 analyzes the behavior of heterotrophic bacteria in an MBBR reactor operating as a Partial Nitritation/ Anammox (PN/A) system. It discusses the growth strategies that hetrotrophic bacteria pursue when facing substrate scarcity. The effect of the yield-strategy is analyzed in two scenarios. In the first scenario a group of heterotrophic bacteria growing on endogenous COD is investigated, whereas in the second scenario, external COD is allowed into the system and a second group of heterotrophs (rate strategist) growing on the more available external COD is added. The competition between both groups over space, and electron acceptor is assessed. In both scenarios the pursuing of the yield strategy seems to be crucial for the diversity of the heterotrophic community. Effluent concentrations as well as heterotrophic produced dinitrogen gas is strongly affected by the growth-strategy that the heterotrophs selected, higher denitrification activities are observed when the yield strategy is selected. Finally dimensionality is the microscale feature of interest in the third publication P3. An MABR reactor used for PN/A is modelled. Publication P3 compares a traditional one-dimensional model and different pseudo two-dimension models that allow the implementation of concentration gradients in the bulk liquid and the gas phase, individually and simultaneously as well as in counter or parallel flow. The results show that the one-dimensional model underestimates the effluent’s total dissolved nitrogen concentration in comparison to the prediction delivered by the pseudo two-dimensional models. Differences in the axial gradients in the biofilm are also observed between the two evaluated modelling approaches. P3 also demonstrates that the concentration gradients in the gas phase have a more significant impact on the modelling results than the concentration gradients in the bulk liquid. The importance of the microscale features: microbial composition and dimensionality is explored. Alongside, the implications on the global modelling results, product of the simplifications of microscale features are investigated. In the case of microbial composition, although more information has been made available due to the new experimental techniques (molecularbiology, imagining etc.) there are still disparities between what can be determined experimentally and how this can be implemented into the existent modelling frameworks. In the case of dimensionality, longitudinal gradients seem to be more influential than it was previously assumed and need to be taken into account to better describe MABRs. The adequate level of complexity required for a microscale feature and in general for a model should be decided based on the modelling goals, the current understanding of the system and the available data

MUMFORD, Stephen & TUGBY, Matthew (eds.): Metaphysics and Science, Oxford, Oxford University Press, 2013.

Reseña de este libro

Antibacterial Properties of Nanoparticles in Dental Restorative Materials. A Systematic Review and Meta-Analysis

Background and Objectives: Nanotechnology has become a significant area of research focused mainly on increasing the antibacterial and mechanical properties of dental materials. The aim of the present systematic review and meta-analysis was to examine and quantitatively analyze the current evidence for the addition of different nanoparticles into dental restorative materials, to determine whether their incorporation increases the antibacterial/antimicrobial properties of the materials. Materials and Methods: A literature search was performed in the Pubmed, Scopus, and Embase databases, up to December 2018, following PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines for systematic reviews and meta-analyses. Results: A total of 624 papers were identified in the initial search. After screening the texts and applying inclusion criteria, only 11 of these were selected for quantitative analysis. The incorporation of nanoparticles led to a significant increase (p-value < 0.01) in the antibacterial capacity of all the dental materials synthesized in comparison with control materials. Conclusions: The incorporation of nanoparticles into dental restorative materials was a favorable option; the antibacterial activity of nanoparticle-modified dental materials was significantly higher compared with the original unmodified materials, TiO2 nanoparticles providing the greatest benefits. However, the high heterogeneity among the articles reviewed points to the need for further research and the application of standardized research protocols

Someone left this here : memória fotográfica de objetos esquecidos

O presente trabalho “Someone left this here” refere-se aos objetos de estudo e remete para a série fotográfica que engloba o projeto final de mestrado em fotografia. É explorada conceituadamente a problemática do consumismo, desde o processo de marketing de imagem pelo qual passam os objetos novos para apelar o desejo de posse do consumidor, aos despojos dos objetos que já não possuem utilidade prática. Vivemos no tempo dos objetos. Numa sociedade consumista fabricamos, usamos e posteriormente descartamos tudo aquilo que perde a sua funcionalidade, aumentando assim a produção de resíduos. Adquirimos novos objetos e acumulamos outros, tonamo-nos maximalistas no consumo, vivendo numa selva em que o novo homem selvagem condensa as suas poses numa vegetação de vestígios. Estes objetos encontrados nestas “selvas” não fazem parte da sua flora ou fauna no entanto constituem o seu próprio habitat, são objetos mutáveis que podem ganhar diferentes utilidades e significados, podem ser modificados subjetiva e objetivamente, ganham ou perdem valor dependendo do seu contexto de utilidade, possuem sinais de desgaste e cicatrizes dos lugares onde foram encontrados e que fazem parte das marcas de memória inalteráveis de estes objetos, tornando-os únicos e contam a sua história. Os objetos que foram encontrados em lugares abandonados, esquecidos ao acaso pelos seus antigos donos, fazem parte do objeto de estudo de este projeto. Este projeto está dividido em duas vertentes: a memória do habitat onde o objeto foi abandonado e, por outro lado, o registo fotográfico em estúdio, fazendo uma análise do recurso aos despojos para a exploração e criação de uma imagem de produto final como peça de arte.The present work “Someone left this here” refers to the objects of study and refers to the photographic series that includes the final master's project in photography. The problem of consumerism is explored conceptually, from the image marketing process through which new objects go to appeal to the consumer's desire for possession, to the spoils of objects that no longer have practical use. We live in the time of objects. In a consumer society we manufacture, use and subsequently dispose of everything that loses its functionality, thereby increasing the production of waste. We acquire new objects and accumulate others, we become maximal in consumption, living in a jungle in which the new wild man condenses his poses in a vegetation of vestiges. These objects found in these “jungles” are not part of their flora or fauna, however they constitute their own habitat, they are mutable objects that can gain different uses and meanings, can be modified subjectively and objectively, gain or lose value depending on their context of usefulness, they have signs of wear and scars from the places where they were found and which are part of the unalterable memory marks of these objects, making them unique and telling their story. The objects that were found in abandoned places, forgotten at random by their former owners, are part of the object of study of this project. This project is divided into two aspects: the memory of the habitat where the object was abandoned and, on the other hand, the photographic record in the studio, making an analysis of the use of the spoils for the exploration and creation of an image of the final product as a piece of art

Evaluación del proceso de Monitoreo Financiero ejecutado por Casa Del Tercer Mundo (C3M) de proyectos sociales cofinanciados por la Unión Europea (UE) del departamento de Estelí en el periodo 2011-2014

La Investigación que se presenta a continuación evalúa la experiencia adquirida de Casa del Tercer Mundo (C3M) o Ciudades Hermanas en ejecutar el Monitoreo Financiero a proyectos sociales cofinanciados por la Unión Europea (UE) durante el periodo comprendido del 2011 al 2014. Comenzando con una breve descripción de la Normativa financiera establecida por la Unión Europea, las responsabilidades y obligaciones de las partes en el convenio de colaboración, el límite establecido para la ejecución presupuestaria y definiendo además el criterio de los costos elegibles para la acción y los costos variables resultantes de esta

Metastability effects on the photoluminescence of ZnO nano-micro structures grown at low temperature and influence of the precursors on their morphology and structure

Nanocrystalline ZnO films were grown on silicon substrate by hydrothermal synthesis at 125 °C, using diethanolamine as stabilizer. A powder containing ZnO spheres, with diameters between 100 to 200 nm and formed by aggregation of ZnO nanoparticles, was also obtained as a secondary reaction product. The samples were studied by scanning electron microscopy, X-ray diffraction and photoluminescence (PL) spectroscopy. The effects of the [diethanolamine]/[Zn+2] molar ratio on morphological, structural and optical properties were studied, as well as the effect of laser illumination (=325 nm) and annealing treatment on photoluminescence properties. The film samples exhibited a compact columnar structure, with thickness between 180 to 210 nm, which were not strongly affected by the diethanolamine concentration. The X-ray diffraction patterns from the films evidenced preferred orientation along the c-axis of the ZnO wurzite structure; while the nanospheres did not show any preferential crystalline direction. The PL spectra from the films showed large initial UV emission and a weak defect band centered in the yellow. A PL evolution while the samples were UV illuminated, attributed to oxygen vacancy generation following the photoinduced equilibration of metastable structures, was observed.Fil: Gonzalez, Vanessa. Instituto de Física del Noroeste Argentino, INFINOA (CONICET-UNT); Argentina. NanoProject - LNPD, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán; ArgentinaFil: Marín Ramírez, Oscar Alonso. Instituto de Física del Noroeste Argentino, INFINOA (CONICET-UNT); Argentina. NanoProject - LAFISO, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán; ArgentinaFil: Tirado, Monica Cecilia. Instituto de Física del Noroeste Argentino, INFINOA (CONICET-UNT); Argentina. NanoProject - LNPD, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán; ArgentinaFil: Comedi, David Mario. NanoProject - LAFISO, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán; Argentina. Instituto de Física del Noroeste Argentino, INFINOA (CONICET-UNT); Argentin

Effects of methanol on morphology and photoluminescence in solvothermal grown ZnO powders and ZnO on Si

ZnO nano and microstructures were obtained by solvothermal synthesis using hexamethylenetetramine (HMTA) as alkaline agent, and water, water/methanol and methanol as solvents. Two types of samples were obtained: a ZnO powder that grew at the bulk solution and ZnO on silicon substrates. The effect of the solvent on the morphology and optical emission was studied, as well as the influence of the growth zone. With increasing methanol content, the morphology changed from nanorods to nanoparticles powders, and from oriented arrangement of nanorods to thin film on silicon substrates. Important changes in photoluminescence induced by the methanol content and depending on the growth zone were also observed.Fil: Marín Ramírez, Oscar Alonso. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: González, Vanessa. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Tirado, Monica Cecilia. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Comedi, David Mario. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán; Argentin