https://repositorio.uoh.cl/handle/611/6 2026-04-08T08:38:24Z https://repositorio.uoh.cl/handle/611/1100 Respuesta metabolómica en raíces de portainjertos contrastantes de Lagenaria siceraria y hojas del injerto Citrullus lanatus bajo condiciones de estrés por sequía Flores Chacón, Raúl La sandía (Citrullus lanatus) requiere altos volúmenes de agua para alcanzar un adecuado llenado de frutos, lo que hace crítico el estudio del déficit hídrico en su cultivo. Una estrategia efectiva para enfrentar este problema es el uso de portainjertos tolerantes como Lagenaria siceraria, conocidos por sus características morfofisiologícas que favorecen la resistencia al estrés por sequía, además del uso de riego deficitario, para así aplicar la cantidad mínima de riego que necesita el cultivo sin dañar su producción. Este estudio analizó el perfil metabolómico de raíces e injertos en plantas injertadas sobre dos accesiones de L. siceraria (Illapel y Philippines) y un homoinjerto de C. lanatus, bajo condiciones de riego completo y estrés hídrico. Los resultados revelaron una acumulación diferencial de metabolitos en hojas de C. lanatus injertadas sobre Illapel, identificando 16 metabolitos compartidos entre ambos tejidos, asociados principalmente a mecanismos de defensa frente al estrés abiótico. Además, el análisis de enriquecimiento funcional evidenció la activación de rutas metabólicas relacionadas con la osmorregulación, el balance redox y el metabolismo energético, destacando el papel del injerto en la adaptación de la planta al déficit hídrico. Citrullus lanatus, sequía, riego deficitario, Lagenaria siceraria, metabolitos, producción. 2025-01-01T00:00:00Z https://repositorio.uoh.cl/handle/611/985 Winogradsky Bioelectrochemical System as a Novel Strategy to Enrich Electrochemically Active Microorganisms from Arsenic-Rich Sediments Cantillo-González, A; Anguita, J; Rojas, C; Vargas, IT Bioelectrochemical systems (BESs) have been extensively studied for treatment and remediation. However, BESs have the potential to be used for the enrichment of microorganisms that could replace their natural electron donor or acceptor for an electrode. In this study, Winogradsky BES columns with As-rich sediments extracted from an Andean watershed were used as a strategy to enrich lithotrophic electrochemically active microorganisms (EAMs) on electrodes (i.e., cathodes). After 15 months, Winogradsky BESs registered power densities up to 650 mu Wcm(-2). Scanning electron microscopy and linear sweep voltammetry confirmed microbial growth and electrochemical activity on cathodes. Pyrosequencing evidenced differences in bacterial composition between sediments from the field and cathodic biofilms. Six EAMs from genera Herbaspirillum, Ancylobacter, Rhodococcus, Methylobacterium, Sphingomonas, and Pseudomonas were isolated from cathodes using a lithoautotrophic As oxidizers culture medium. These results suggest that the tested Winogradsky BES columns result in an enrichment of electrochemically active As-oxidizing microorganisms. A bioelectrochemical boost of centenarian enrichment approaches, such as the Winogradsky column, represents a promising strategy for prospecting new EAMs linked with the biogeochemical cycles of different metals and metalloids. 2022-01-01T00:00:00Z https://repositorio.uoh.cl/handle/611/986 Writing encounters at Higher Education entry: Students' social representations in six areas of knowledge Navarro, F.; Gajardo, F.; Falcón, P.; Insúa, E. The expansion of Higher Education shows rising drop-out rates during the first university year, which has fostered the adoption of learning support initiatives. However, little is known about the experiences and expectations of new students. The aim of this article is to account for the social representations of academic writing teaching expressed by first-year university students. To that end, it conducts a contrastive analysis of 360 open answers given by 180 informants from six knowledge areas (Arts, Humanities, Engineering, Health Sciences, Science Pedagogy, and Social Sciences) in a metropolitan state university in Chile. The corpus was qualitatively coded using emergent categories followed by a quantification of occurrences, an inter-rater reliability calculation and a classification of disciplines. Results show that for students the discursive and procedural features of indistinctive genres, such as the essay, are the most challenging writing aspects, especially the management of sources and perspectives, the fulfilment of expectations from teachers and disciplinary communities, and the development of ideas throughout texts. Students consider that writing is learnt through exercising and practice together with the guidance and feedback from teachers and tutors and other complementary strategies such as text deconstruction, modeling, scaffolding and peer work, although they are not able to identify the institutional and curricular environments that offer literacy teaching. These findings may help institutions make the most of young students' experiences and expectations to facilitate their access to the writing practices of their future disciplinary communities. 2019-01-01T00:00:00Z https://repositorio.uoh.cl/handle/611/984 Wild, Indigenous, Lame, Invalid: Anti-ableist Epistemologies of the South Pino-Morán, JA; Rodriguez-Garridoa, P; Lapierre, M The aim of the article was to present a first approach to an epistemological proposal that reflects on and deals with the construction and legitimation of knowledge generated from abject, abnormal, or crippled corporealities geopolitically located in the South. It pays special attention to the sex-gender-ability system in the social and epistemological organization of knowledge. In this development, we identify a positionality and wasted wealth for regional social analysis and transformation as a result of a modern colonial order. Hence, this proposal is inscribed within the Latin American critical thought to reflect on those other of enunciation. 2023-01-01T00:00:00Z