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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Avaliação dos efeitos genotóxicos e citogenéticos na população de trabalhadores de mineração de carvão de Cerrejón (Guajira-Colômbia) utilizando diferentes biomarcadores

León Mejía, Grethel January 2011 (has links)
Durante as atividades de mineração de carvão são liberadas ao ambiente grandes quantidades de partículas de pó, cinzas, hidrocarbonetos aromáticos policíclicos (HAP) e metais pesados. Uma vez no ambiente, estas sustâncias constituem misturas complexas, um dos maiores riscos ocupacionais para a saúde e segurança dos trabalhadores, se levarmos em conta o efeito sinérgico, aditivo e potencializador da mistura resultante. Uma vez no organismo, este tipo de coquetel tem a capacidade de interagir com mecanismos celulares como ativação de macrófagos, células epiteliais e fibroblastos, e durante esta estimulação podem ser liberadas substâncias como espécies reativas de oxigênio (ERO), capazes de danificar importantes macromoléculas como o DNA. Compostos como os HAP, presentes nas misturas, apresentam uma atividade mutagênica e carcinogênica comprovada, pela capacidade que tem de formar adutos com as purinas depois da sua ativação metabólica. O objetivo do presente estudo foi avaliar os efeitos genotóxicos, citogenéticos e a presença de metais na população de trabalhadores exposta aos resíduos da mineração de carvão de Guajira-Colômbia. Foram incluídos no estudo 100 trabalhadores expostos e 100 indivíduos controle. O grupo exposto foi dividido de acordo com suas diferentes atividades na área de mineração: (i) transporte de carvão extraído (ii) manutenção de equipamento no campo, (iii) mineração de carvão e (iv) embarque de carvão. Para a aplicação do teste ensaio cometa versão alcalina, foram usados linfócitos de sangue periférico e foram avaliados os parâmetros índice de dano (ID), tamanho da cauda e % de DNA na cauda. Para avaliar o dano cromossomal, foi utilizado o teste de micronúcleos em linfócitos e amostras de mucosa oral para avaliar a frequência de micronúcleos em 2000 células. O conteúdo de metais nas amostras do sangue foi analisado mediante a técnica de emissão de raios-X induzidas por partículas (PIXE). Nos biomarcadores avaliados nos ensaios cometa, micronúcleos em linfócitos e micronúcleos em mucosa oral, foram observados valores significativamente maiores no grupo exposto comparado com o grupo controle. Nos resultados da análise dos níveis de elementos químicos pelo método PIXE, foram encontradas quantidades significativamente maiores de Si e Al no grupo exposto, metais que estão presentes nas cinzas voláteis de carvão. Na análise dos resultados obtidos nos diferentes testes, não foi observada correlação entre a idade, o consumo de álcool e o tempo de serviço. Também não foi encontrada diferença significativa entre as atividades de mineração (áreas de trabalho) avaliadas. As informações geradas por este estudo são os primeiros dados para a Colômbia sobre os efeitos genotóxicos em trabalhadores expostos aos resíduos de mineração de carvão e contribuem para o estabelecimento de políticas adequadas de controle e prevenção para estas populações. / During coal mining activities, large quantities of coal dust, ashes, Polycyclic Aromatic Hydrocarbons (PAH), and heavy metals are released at the environment. Once into the atmosphere, these substances constitute a complex mixture. This mixture became one of the most important occupational risks for workers health and safety due to synergistic, additive and enhancing effects. Once inside the organism this cocktail-like mixture can interact with cellular mechanisms related with reactive oxygen species (ROS) production, and being capable of cause damage in important macromolecules as DNA. Compounds such as PAH present in this mixture, has a proven mutagenic and carcinogenic activity for the capacity that they have to form adducts with the purines after its metabolic activation in the organism. The aim of the present study was to evaluate the genotoxic and cytogenetic effects together with the presence of metals, in an exposed workers population to coal mining residues of Guajira-Colombia. 100 exposed workers and 100 non-exposed control individuals were included in this study. The exposed group was divided according to different mining area activities: (i) Transport of extracted coal (ii) Equipment field maintenance (iii) Coal stripping and (iv) Coal embarking. For the Comet assay (alkaline version) peripheral blood lymphocytes were used. In this case, the evaluating the parameters were: damage index (DI), tail length and % of tail DNA. To determine chromosomal damage, the micronucleus frequency in lymphocytes and buccal mucose samples were used. 2000 cells per individual were evaluated. The metals content on blood samples were analyzed by emission of ray-X induced by particles technique (PIXE). The results evaluated with the comet assay and micronuclei in lymphocytes were found significantly higher in exposed group compared with the non exposed-control group. For these biomarkers no difference was observed between the exposed groups executing different mining activities. Analysis of metals by PIXE method, showed no significant differences between mining activities in the exposed group. Comparing element’s levels in exposed and control group, we found significant higher values for Si and Al within the exposed group. Both metals are common in the coal fly ash. At the same time, we didn´t find any correlation between age, alcohol consumption and time of service, and any values from the evaluated biomarkers. There also weren’t found any significant differences between evaluated mining activities (work areas). To our knowledge, the information from this study is the first data generated about genotoxic effects in workers exposed to coal mining residues in Colombia and contributes to establish appropriate control and prevention politics on these populations.
12

Planeamiento estratégico para el departamento de La Guajira

Bernal Fandiño, Oscar, Lozano Puyana, Margarita, Mejía Ferrero, Diego, Velandia Garzón, Alberto 30 July 2018 (has links)
El presente plan estratégico está enfocado en el Departamento colombiano de La Guajira, estableciendo como visión que para 2027, el departamento será un referente nacional de la competitividad, fundamentado en pilares de gran importancia como el desarrollo social, el mejoramiento de la educación, la ampliación de la cobertura de la salud, la reducción de la pobreza, el desarrollo portuario y minero-energético, y la innovación tecnológica, impulsado en gran medida por el desarrollo del turismo ecológico y su proyección al mercado internacional, fortaleciendo de la misma manera la infraestructura de éste sub-sector, para así asegurar una mejor cobertura, generando de esta manera mejores y mayores beneficios para todos sus pobladores. Para la realización de este profundo estudio, se utilizó el modelo de Planeamiento Estratégico elaborado por el profesor Fernando D’Alessio. Se analizaron aspectos económicos, sociales, tecnológicos, ambientales, políticos, de seguridad y algunos otros que permitieron llegar a conclusiones finales, que posibilitaron la propuesta de mejora de objetivos de largo y corto plazo, buscando el beneficio departamental. Los resultados obtenidos indican que a pesar de las fuertes adversidades por las que el departamento ha venido pasando durante los últimos años, la región guajira cuenta con la suficiente capacidad y un enorme potencial para convertirse en una de las regiones más prosperas de Colombia. Es importante resaltar que para lograr esta ambiciosa meta se requiere contar con el acompañamiento de este plan estratégico, que con certeza agregará valor a sus potencialidades ventajas comparativas locales, para así elevar la productividad y competitividad presentes, pero que al final las transformará en ventajas competitivas sólidas y contundentes para consolidar dichas metas, aumentar la calidad de vida y la sostenibilidad ambiental / The focus of this Strategic Plan is La Guajira Department in Colombia, envisioning that by the year 2027, it will be a national benchmark of competitiveness, based on important pillars, such as, social development, improvement of the education system, expansion of health-care coverage, poverty alleviation, development of the port and the energy-mining industry, and technological innovation, boosted by the growth of eco-tourism, its projection in the international market, and the strengthening of this sub-sector’s infrastructure, by seeking to ensure a better coverage, thus generating better and greater benefits for all its inhabitants. The Strategic Planning model, developed by professor Fernando D'Alessio, was applied when carrying out this detailed research. Economic, social, technological, environmental, political, security and other aspects were analyzed to reach the final conclusions, which enabled to create the proposal for the improvement of long and short-term objectives, striving to benefit the Department. Results show that, despite the strong adversities that La Guajira has been experiencing in recent years, this is a region with the adequate capacity and enormous potential to become one of the most prosperous regions in Colombia. It is important to emphasize that to achieve this ambitious goal, the follow up of this Strategic Plan is a must, it will certainly add value to its potential local comparative advantages, to increase its current productivity and competitiveness, which at the end, will transform them into solid, conclusive and competitive advantages to consolidate these goals, to increase the well-being of the people, and the environmental sustainability
13

Linguistic Outcomes of the Wayuunaiki-Spanish Language Contact Situation

Méndez-Rivera, Nelson José 14 July 2020 (has links)
The study of Spanish in contact with Wayuunaiki has received limited attention in generative and variationist analyses. In particular, the possible influence of this indigenous language on some parts of the Spanish language has not been investigated or has been only briefly addressed. This dissertation aims to fill this existing gap by studying two morpho-syntactic variables: (i) the distribution of null and overt subjects (NOS) as portrayed by the Null Subject Parameter and overt subject personal pronoun (SPP) expression as traditionally researched in variationist studies, and (ii) the issue of subject-verb agreement within the theory of features. To carry out these studies, we collected spontaneous data from 27 Wayuunaiki-Spanish bilinguals and five Spanish monolingual speakers. This Spanish monolingual group served as the vernacular benchmark. The NOS and SPP expression are among the most studied topics in Hispanic linguistics, but they have never been systematically researched in Guajiro Spanish. By analyzing these issues in our dissertation, we want to contribute new data to their study and to the properties and factors affecting them, in order to widen the knowledge of how they function in this Spanish language contact situation. In the generative analysis of the null/overt subjects we investigate whether the distinction that occurs in Wayuunaiki between stative and active verbs and the participants’ proficiency in Spanish have an impact on the distribution of NOS in Guajiro Spanish. In the variationist study, a number of independent variables widely believed to constrain variable SPP expression are factored into the investigation to find out how they behave in this particular language contact situation. These variables include person/number, TAM, switch reference, priming effects, etc. The second research topic is subject-verb agreement. This is only investigated from the generative grammar perspective, specifically by employing the concept of features to explain the nature of the subject-verb mismatches produced by the Wayuunaiki dominant Wayuunaiki-Spanish bilinguals. We specifically investigate whether the Spanish conjugation system poses a problem to the bilingual speakers’ ability to produce the native Spanish verb forms vis-à-vis the monolingual cohort and whether this ability is shaped by the participants’ proficiency in Spanish. The results of the three studies contribute to the field of Hispanic linguistics from three different perspectives. The study of NOS adds a new dimension to the pro-drop parameter: the possible role that Wayuunaiki’s double conjugation may play in the distribution of null and overt subject pronouns in Guajiro Spanish. The variationist study provides new data on the topic of SPP expression in a variety of Spanish which, in this specific case, has as contact language an understudied indigenous language. The analysis of the subject-verb mismatches that occur in Guajiro Spanish allows us to differentiate between the status of null and overt subjects with respect to subject-verb agreement and to differentiate between this contact variety and the Colombian vernacular benchmark.
14

Improving the thermal climate of schools in semi-desert climate : A case study of solutions in La Guajira, Colombia / Förbättringar av det termiska klimatet på skolor i halvökenklimat : En fallstudie av lösningar i La Guajira, Colombia

Johansson, Michael January 2023 (has links)
As the climate changes, hot regions like La Guajira's semi-desert will become even hotter. It is projected that the average temperature in this region will increase by 2.4 ℃ over the course of this century, with a 20 % reduction in precipitation. To ensure that these areas remain habitable in the future, implementing technical solutions will be necessary to mitigate the impacts on the people living there. A field study assessed the thermal comfort at a school in Manaure, which experiences excessively high temperatures that exceed international standards for good thermal comfort. Through subjective and objective data collection, the field study concluded that the school's thermal climate would negatively impact at least 83 % of the students. The study also found that the surface temperature of desks not exposed to sunlight reached a temperature of 43 ℃. To improve thermal comfort, three potential solutions were explored. Isolating the roof reduces incoming radiation and prevents excess heat from warming the structure. Increasing the ventilation rate helps dissipate hot air, and planting trees creates a cooler supply air temperature. Two of the three measures were implemented, and the tree-planting project is ongoing. Temperatures were measured on the roof, walls, desk and floor during a hot day. Together with a survey to students and teachers to evaluate the absolute temperature and the experienced thermal comfort. The results demonstrated that isolating the roof and installing a solar chimney on the classroom's roof can significantly lower the operative temperature to 36 ℃ and 35 ℃, respectively. These improvements can improve learning by 25 % due to better thermal comfort compared to a classroom that has not been modified. As a bonus, the acoustics were also improved in classrooms, resulting in a lower echo level. Overall, the study demonstrated that it is possible to significantly improve the thermal comfort of classrooms in semi-desert regions, even those without access to electricity. An added benefit is that these solutions have a low installation cost and no operational costs. However, further research is needed to determine the impact of heat on children and whether these measures will improve their learning outcomes. / A medida que cambie el clima, las regiones cálidas como el subdesierto de La Guajira se volverán aún más calientes. Se proyecta que la temperatura promedio en esta región aumente 2,4 ℃ en el transcurso de este siglo, con una reducción del 20 % en las precipitaciones. Para garantizar que estas áreas sigan siendo habitables en el futuro, será necesario implementar soluciones técnicas para mitigar los impactos en las personas que viven allí. Un estudio de campo evaluó el confort térmico en una escuela de Manaure, que experimenta temperaturas excesivamente altas que superan los estándares internacionales de buen confort térmico. A través de la recolección de datos subjetivos y objetivos, el estudio de campo concluyó que el clima térmico de la escuela impactaría negativamente al menos al 83 % de los estudiantes. El estudio también encontró que la temperatura de la superficie de los escritorios no expuestos a la luz solar alcanzó una temperatura de 43 ℃. Para mejorar el confort térmico, se exploraron tres posibles soluciones. Aislar el techo reduce la radiación entrante y evita que el exceso de calor caliente la estructura. El aumento de la tasa de ventilación ayuda a disipar el aire caliente y la plantación de árboles crea una temperatura del aire de suministro más fría. Se implementaron dos de las tres medidas y el proyecto de plantación de árboles está en curso. Se midieron las temperaturas en el techo, las paredes, el escritorio y el piso durante un día caluroso. Junto con una encuesta a estudiantes y docentes para evaluar la temperatura absoluta y el confort térmico experimentado. Los resultados demostraron que aislar el techo e instalar una chimenea solar en el techo del aula puede reducir significativamente la temperatura operativa a 36 ℃ y 35 ℃, respectivamente. Estas mejoras pueden mejorar el aprendizaje en un 25 % debido a un mejor confort térmico en comparación con un aula que no ha sido modificada. Como beneficio adicional, también se mejoró la acústica en las aulas, lo que resultó en un nivel de eco más bajo. En general, el estudio demostró que es posible mejorar significativamente el confort térmico de las aulas en las regiones semidesérticas, incluso aquellas sin acceso a la electricidad. Un beneficio adicional es que estas soluciones tienen un bajo costo de instalación y no tienen costos operativos. Sin embargo, se necesita más investigación para determinar el impacto del calor en los niños y si estas medidas mejorarán sus resultados de aprendizaje. / När klimatet förändras kommer redan varma regioner som halvöken i La Guajira, Colombia att bli ännu varmare. Den genomsnittliga temperaturen i regionen förväntas att öka med 2,4 ℃ under det här århundradet, samtidigt som nederbörden minskar med     20 %. För att dessa områden ska vara beboeliga i framtiden kommer det vara nödvändigt att implementera tekniska lösningar för att mildra konsekvenserna för de människor som bor där. En fältstudie genomfördes för att undersöka termisk komfort på en skola i Manaure, som upplever extremt höga temperaturer vilket överskrider internationella standarder inom termisk komfort. Genom subjektiv och objektiv datainsamling konstaterade fältstudien att skolans termiska klimat kommer påverka minst 83% av eleverna negativt. Studien visade också att temperaturen på skrivborden som inte utsatts för solljus nådde 43 ℃. Temperaturer mättes på tak, väggar, skrivbord och golv under en varm dag. Tillsammans med en undersökning till elever och lärare för att utvärdera den absoluta temperaturen och den upplevda termiska komforten. För att förbättra den termiska komforten undersöktes tre olika möjligheter. Att isolera taket minskar den inkommande strålningen och förhindrar att överflödig värme värmer upp konstruktionen. Ökningen av ventilationen hjälper till att avlägsna het luft och sist även plantera träd för att skapa en svalare utomhustemperatur. Av de tre åtgärderna genomfördes två, och projektet med att plantera träd pågår. Resultaten visade att den operativa temperaturen kan sänkas till 36 ℃ om taket isoleras och ytterligare till 35 ℃ om en solskorsten installeras på taket i klassrummen. Sammantaget kan inlärningen förbättras med åtminstone 25 % jämfört med ett klassrum som inte förbättrades. En positiv bieffekt var att akustiken i klassrummen förbättrades genom mindre eko. Sammanfattningsvis visade studien att det är möjligt att betydligt förbättra den termiska komforten i klassrum i halvökenklimat, även i klassrum utan tillgång till el. En annan fördel är att dessa lösningar har en låg installationskostnad och inga driftskostnader. Dock krävs ytterligare undersökningar för att fastställa vilken påverkan värme har på barn och om dessa åtgärder kommer att förbättra deras lärande.
15

Addressing Water Scarcity in La Guajira: A Comparative Analysis of Four Water Systems

Hedstrand Welander, Johan January 2023 (has links)
During the recent prolonged drought in La Guajira, Colombia, the child mortality rate surged to 23.4 per 1000. With the focal point in rural Alta Guajira, a lack of rainfall and wind resulted in an acute potable water scarcity. This paper presents data gathered from interviews conducted with members of the Wayúu indigenous group residing in Alta Guajira and the results surveying in field the solutions already present to the water scarcity. Four potential technological solutions were then devised and evaluated in this context: wind-driven wells, solar-driven wells, solar stills, and reverse osmosis desalination systems. This study shows that reverse osmosis desalination systems are economically unfeasible due to their high initial investment. Solar stills are concluded to be potentially viable for drought emergencies but prohibitively expensive due to their low productivity and area requirements. Solar-driven wells frequently break in the region, likely due to inadequate insulation in underground electrical components, but they represent a crucial yet non-existent complement for water production. Wind-driven wells are the most prominent water source, although relying solely on these creates significant risks. Hence a suggestion for mainly wind-driven production, complemented with solar-driven production, and backed by emergency systems of manual wells and solar stills is suggested.

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