Melhorias habitacionais com participação comunitária no controle da re-infestação por Triatoma dimidiata em Jutiapa, Guatemala

The study assessed risk factors for indoor Triatoma dimidiata infestation in Guatemala and implemented interventions in household hygiene and housing construction. Four villages with persistent (post-spraying) T. dimidiata infestation were studied. An ecosystem approach was implemented with the support of the interdisciplinary team; homeowners conducted wall improvements along with improvement of household sanitation. A new plaster mix for walls was developed and used in a separate intervention. Both interventions were associated with a reduction in infestation, but only the ecosystem approach produced important housing improvements capable of preventing re-infestation in the long term

Factores de riesgo para la infestación intradomiciliaria por el vector de la enfermedad de Chagas, Triatoma dimidiata, en Jutiapa, Guatemala

The study evaluates variables such as hygienic and construction conditions of households, cultural practices, and socioeconomic status, as possible risk factors for intradomiciliary infestation by Triatoma dimidiata. Similar to other triatomines that form domestic colonies, T. dimidiata hides in cracks in earthen/adobe walls, under loose plaster, behind furniture, behind pictures or other wall ornaments, and under bed mattresses. The hygiene and construction practices of rural houses make them suitable for infestation and are directly linked to socioeconomic status and cultural practices. Approaches to control must include better wall plastering and sanitation.Seiscientas cuarenta y cuatro casas en Jutiapa, Guatemala fueron encuestadas en el año 2004 para buscar el vector de la enfermedad de Chagas Triatoma dimidiata. Diecisiete variables relacionadas con las condiciones estructurales y de higiene de las casas fueron registradas y evaluadas como factores de riesgo para la infestación intradomiciliar con T. dimidiata. Análisis chi-cuadrado detectaron asociaciones significativas entre la presencia del vector y 8 de estas variables. En modelos log-lineares se detectó, que sin importar la antigüedad de la casa, las posibilidades de presencia del vector fueron 4,3 y 10 veces más bajas en casas con un buen estado socioeconómico que en casas pobres o muy pobres, respectivamente. Además, las posibilidades de infestación fueron mayores en casas con paredes sin repello (3,85 veces) o con repellado incompleto o de mala calidad (4,56 veces), que con repellado completo. Las estrategias para el control de T. dimidiata deberían incluir la introducción de repellos baratos y de buena calidad y la promoción de mejores prácticas sanitarias. Estas estrategias no solo reducirían o eliminaría la infestación, sino también ayudaría a prevenir la reinfestación

Tropical freshwater ostracodes as environmental indicators across an altitude gradient in Guatemala and Mexico

Ostracodes are bivalve microcrustaceans with calcium carbonate shells that preserve well in lake sediment. They are very sensitive to environmental variables and are therefore powerful tools in paleoclimate and paleoenvironmental studies that cover time periods from decades to millions of years. Detailed knowledge of species ecological preferences and robust taxonomy are prerequisites for such studies. Such information, however, is still lacking for many areas of the world, including the Neotropics. Previous studies in the northern Neotropics were conducted mainly in the karst lowlands of the Yucatán Peninsula, but higher-altitude areas remained relatively poorly investigated. This study was designed to expand our knowledge of the modern, Neotropical freshwater ostracode fauna, across an altitudinal gradient from the karst lakes in the lowlands of El Petén, Guatemala (~100 - 500 m asl), to the mid-elevation water bodies of the Lacandón forest (~500 - 1000 m asl), to the higher-altitude lakes of Montebello, Chiapas, México (~1000 - 1500 m asl). Eighteen ostracode species were identified in 24 lakes. Ostracodes were absent in Lakes Amarillo and Lacandón (mid-altitude), and San Diego (lowlands). Statistical analysis indicated that the most abundant species, Cypridopsis vidua, Cytheridella ilosvayi, Pseudocandona antillana, and Darwinula stevensoni have a continuous distribution along the entire altitudinal gradient. Other species display more restricted distributions, determined by temperature, precipitation and conductivity. For example, Eucypris sp. is restricted to the lowlands, Vestalenula sp. and Cypria sp. were found only at middle elevations, and a Cyprididae species was restricted to the highlands. Species diversity is slightly greater in warm lakes at middle altitudes (Haverage = 1.09) than in water bodies in the lowlands (Haverage = 0.94) and in cooler lakes in the highlands (Haverage = 0.94). LOESS regressions provided ecological preference information for the four most frequent and widely distributed species, with respect to temperature, conductivity, bicarbonate (HCO3-) concentration, precipitation, and pH. Cypria petenensis, Heterocypris punctata, and Paracythereis opesta display higher abundances in lowland lakes, whereas, Cytheridella ilosvayi, and Pseudocandona antillana prefer lowland and mid-elevation lakes. Environmental conditions in the higher-elevation lakes of Montebello favor the presence of Darwinula stevensoni. Such quantitative ecological information will improve ostracode-based paleoenvironmental reconstructions in southern México and northern Guatemala, and our approach serves as a model for future paleoecological studies that employ other aquatic bioindicators, such as testate amoebae, cladocerans, and chironomids

Estrategias didácticas para favorecer la socialización en el nivel preescolar

Licenciatura en Educació

Lake sedimentary DNA research: Extending the sedaDNA network across Latin America

Collaboration between Dr. Echeverría and Dr. Moguel was carried out with the support of the PAGES-IAI International Mobility Research Fellowship Program during August and September 2022. This project allowed Dr. Echeverría to explore new insights into ancient DNA (aDNA) and sedimentary DNA (sedaDNA) analysis, supervised by Dr. Moguel, who has extensive experience in exploring sedaDNA and working in metagenomic studies at UNAM-Juriquilla, México.Fil: Echeverria, Marcos Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Moguel, Bárbara. Universidad Autónoma de México; Méxic

Transfection of Platyhelminthes

Flatworms are one of the most diverse groups within Lophotrochozoa with more than 20,000 known species, distributed worldwide in different ecosystems, from the free-living organisms in the seas and lakes to highly specialized parasites living in a variety of hosts, including humans. Several infections caused by flatworms are considered major neglected diseases affecting countries in the Americas, Asia, and Africa. For several decades, a particular interest on free-living flatworms was due to their ability to regenerate considerable portions of the body, implying the presence of germ cells that could be important for medicine. The relevance of reverse genetics for this group is clear; understanding the phenotypic characteristics of specific genes will shed light on developmental traits of free-living and parasite worms. The genetic manipulation of flatworms will allow learning more about the mechanisms for tissue regeneration, designing new and more effective anthelmintic drugs, and explaining the host-parasite molecular crosstalk so far partially inaccessible for experimentation. In this review, availability of transfection techniques is analyzed across flatworms, from the initial transient achievements to the stable manipulations now developed for free-living and parasite species