9 research outputs found
Hydrological conceptual model characterisation of an abandoned mine site in semiarid climate : the Sierra de Cartagena-La Unión (SE Spain)
No full textA comprehensive study at Sierra de Cartagena-La Unión (SE Spain) abandoned mine site was carried out to characterise the regime and water quality of the groundwater system after the mine closure. The system consists of five geologic fractured blocks belonging to the Alpujarride and Nevado-Filabride complexes. The aquifer units are composed of limestone and dolostone materials. Recharge is mainly controlled by the N-130 fault system, man-made induced fractures, open-pits and underground workings. Discharge is indicated from open pit lakes by the proximal dome-shaped groundwater level contours. Aquifer natural recharge, assessed by fracture density maps and chloride mass balance, provided consistent results. The water hydrochemical facies show a marked sulphate concentration and acidic pH (average pH of 2.53-6.30). A maximum concentration of 4,100 mg/L of Zn and 40,000 mg/L of sulphate was observed in open-pit lakes. Springs present the lowest residence time and are low mineralised with an average pH of 7.6. Geochemical modelling based on the PHREEQCI code indicates water undersaturation with respect to almost all related mineral species and anoxic conditions prevail in the system. Although an adequate understanding of the regional system is provided, a further detailed hydrochemical study is necessary to assess the undergoing geochemical changes
Colombia diversidad biótica XV : Los bosques de robles (Fagaceae) en Colombia : Composición florística, estructura, diversidad y conservación
No full textilustraciones, mapas, fotografíasLos bosques de roble dominados por Quercus humboldtii se clasifican en dos grandes formaciones o clases fitosociologicas. La vegetación de la clase Billio roseae-Quercetea humboldtii se establece en la región subandina en altitudes menores a 2400 m en sectores con montos de precipitación mayores a 2000 mm anuales, mientras que la vegetación de la clase Myrsino coriaceae-Quercetea humboldtii, se establece en la región andina (por encima de 2400 m de altitud) en localidades cuyos montos de precipitación anual son menores de 2000 mm. La altitud (asociada con la temperatura) y la precipitación ejercen una influencia marcada en la composición florística y en la estructura de los robledales en Colombia. (texto tomado de la fuente)RESUMEN AMPLIADO -- LOS BOSQUES DE ROBLE (Quercus humboldtii BONPL.) EN COLOMBIA: ASPECTOS FLORÍSTICOS, ESTRUCTURALES Y SINTAXONÓMICOS -- GRADIENTES AMBIENTALES EN LOS BOSQUES DE ROBLE (Quercus humboldtii BONPL.) DE COLOMBIA: INFLUENCIA DE LA ALTITUD Y LA PRECIPITACIÓN EN LA COMPOSICIÓN FLORÍSTICA Y LA ESTRUCTURA DE LOS ROBLEDALES -- BOSQUES DE ROBLE NEGRO colombobAlANus eXcelsA (LOZANO, HERN. CAM. & HENAO) NIXON & CREPET EN COLOMBIA: SINTAXONOMÍA, COMPOSICIÓN FLORÍSTICA Y ESTRUCTURA -- LA FLORA VASCULAR DE LOS BOSQUES DE ROBLE (FAGACEAE) EN COLOMBIA: APROXIMACIÓN INICIAL -- CONSERVACIÓN, MANEJO Y RESTAURACIÓN DE LOS BOSQUES DE ROBLES (Quercus humboldtii BONPL.) EN EL CORREDOR DE CONSERVACIÓN GUANTIVA - LA RUSIA - IGUAQUE GRI (SANTANDER - BOYACÁ, COLOMBIA) -- ANEXO FOTOGRÁFICOprimera edició
A framework to guide the sustainability of wildlife tourism operations: examples of marine wildlife tourism in Western Australia
No full textGrowth in the wildlife tourism industry has been significant in recent years with an increasing focus on tourism centered on free-ranging wildlife. In Australia tourism based in the marine environment, including observing and interacting with coastal and marine wildlife, is increasing in popularity. The future potential for increased growth in marine tourism is dependent upon the abundance and diversity of Australia’s marine wildlife.
Negative impacts of tourism on marine wildlife are difficult to assess as in many cases little is known about the animals or their environment. With the rapid growth in marine tourism the potential for both biophysical and social impacts needs to be recognised. Given the potential impacts and the variable nature of wildlife tourism operations the need arises for a formal auditing and monitoring framework that can identify potential or actual problems and the need for management. This report will examine the opportunities and the barriers in producing a simple, yet reliable framework to assess knowledge available on visitor satisfaction and expectations, identify key areas of product/service improvement, gauge the quality of interpretation programmes, evaluate the effectiveness of impact mitigation strategies and also evaluate the application of key performance indicators for monitoring systems for marine wildlife tourism
Embryonic stem cells: modelling effects ofearly embryo environment
No full textThe Developmental Origins of Health and Disease (DOHaD) hypothesis proposes that embryonic environment can induce permanent changes in metabolism during development, increasing the risk of disease in adults. Adverse environments during critical stages of gestation are sufficient to induce adaptations in offspring and disease susceptibility in later life. Rodent models show that maternal diet exclusively during preimplantation development induces cardiovascular and metabolic disease in adult offspring. Changes must therefore occur within the distinct cell populations of the early embryo and be maintained throughout development. Determining adaptive mechanisms has been challenging due to the small size of the early embryo, and genetic variability in outbred strains previously used. We generated mouse embryonic stem (ES) cells from inbred C57BL/6 mice as a model to overcome these problems. These were used to characterise mechanisms associated with the embryo’s adaptive responses to maternal diet. ES cell lines were derived from blastocysts of C57BL/6 mice assigned to either an isocaloric low protein diet (LPD), or a control diet exclusively through preimplantation development. ES cell lines were characterised for karyotype, sex, gene expression, and functional characteristics including proliferation, death, and metabolism at standardised passages. LPD had no impact on blastocyst formation in vivo or blastocyst cell lineage allocation. Experimental conditions did affect blastocyst outgrowth development in vitro. LPDoutgrowths cultured with less feeder fibroblasts showed slower development than controls. Although LPD blastocyst outgrowth was comparable to controls under high feeder growth conditions, there was a significant reduction in the capacity for ES cell derivation. There was a prominent sex bias towards male ES cell lines. These ES cells retained similar levels of gene expression related to pluripotency, housekeeping and developmental functions irrespective of diet. LPD did not affect growth or metabolism. These cells however showed increased basal apoptosis, and reduced levels of phosphorylated Extracellular signal-regulated kinase (ERK). The reduced ES cell isolation efficiency may indicate a reduced number of pluripotent cells present within the early embryo or increased sensitivity of these cells in response to maternal LPD. Increased apoptosis in ES cells derived from LPD-blastocysts reveal that these cells are indeed more sensitive. Reduced activated ERK may suggest that dysregulated ERK-mediated survival signalling causes enhanced apoptosis. Such adaptations in the early embryo may impact on lineage allocation as differentiation occurs. These ES cell lines may provide a model to investigate such mechanistic adaptations in post-implantation tissues providing further insight into foetal responses to poor nutrition and the induction of adult onset disease
Governing mother-child communication about sex in HIV/AIDS epidemic : positioning Lovelines
No full textIncludes bibliographical references (p. 421-474).Lovelines was a didactic textual series that appeared in Fairlady, a South African women's magazine, instructing mothers on how sex should be talked about with young people to inoculate them against the risk of HIV/Aids. My reading of this media discourse, and mothers' appropriation of it, sought to examine how the primary target audience of middle classed mothers were persuaded to adopt particular communicative positions. Foucault's normative apparatus of family-sexuality-risk concerns the distribution of expertise - epidemiological science of risk in populations, developmental psychology-inscribed micro-practices of childrearing in families - and self-responsibilization of disciplinary power. This finds mothers governmentally positioned as relay points between 'public' (health, economy) and 'private' (family, childrearing, sex) apparatuses, tasked with appropriately socializing a new generation of sexually responsible citizens. This governmental rationality of neo-liberalism is read against South African conditions of mass media persuasion, HIV/Aids risk and talking about sex in families
Uso de hojarasca de roble y bagazo de caña en la producción de pleurotus ostreatus
No full textSe evaluó hojarasca de roble en un relicto de bosque en la Vereda La Capilla de Cajibío(Cauca) durante 6 meses, como sustrato para el crecimiento del hongo Pleurotusostreatus, eligiendo árboles maduros con DAP entre 35 y 37 cm, obteniéndose unpromedio de 7,41 kg de hojarasca por árbol. Se evaluó el crecimiento del hongo enhojarasca mezclada con bagazo de caña y 5 sustratos: T1: bagazo 100%, T2: roble100%, T3: roble 75% y 25% de bagazo, T4: roble 50% y 50% bagazo y T5: roble25% y 75% bagazo, logrando eficiencias biológicas de 221,1%, 44,35%, 52,78%,90,30% y 109,12% respectivamente. Se observó relación inversa entre el contenidode hoja de roble y las eficiencias debido a la naturaleza coriácea y cerosa de la hoja.La mayoría de los carpóforos presentaron 5 a 12 cm de diámetro y contaminacióncausada por hongos competidores del género Trichoderma sp. Se detectaron cambiosen la composición del sustrato agotado, principalmente incremento de minerales yproteínas y disminución de fibra en el bagazo de caña y en la hojarasca de roble,siendo apto para alimentación de animales poligástricos por el contenido de proteínamicelial, presencia de celulosa y menor contenido de lignina
A didactic strategy based on Universal Design for Learning for the resolution of algebraic problems in eighth grade students of the 'Diego de Torres' Educational Institution of Turmequé (Boyacá)
No full textEsta investigación plantea el diseño e implementación de una estrategia didáctica, basada en el Diseño Universal para el Aprendizaje (DUA), para mejorar las habilidades en resolución de problemas algebraicos verbales en estudiantes de grado octavo de la Institución Educativa ‘Diego de Torres’. El diseño metodológico se basa en el paradigma crítico y consiste en un estudio cuasi-experimental sin grupo de control. Para caracterizar las habilidades cognitivas, procedimentales y actitudinales de los estudiantes en torno a la resolución de problemas matemáticos, se aplicó un cuestionario de dominio afectivo y un pre-test. El cuestionario abordó las creencias, emociones y actitudes de los estudiantes hacia la resolución de problemas matemáticos. El pre-test evaluó los procesos realizados por los estudiantes al resolver problemas matemáticos verbales (PAV), con base en los pasos del método Pòlya: comprender, planear, resolver y verificar. También, el pre-test sirvió para establecer el nivel de algebrización de cada estudiante. De acuerdo con los resultados, se diseñó una secuencia didáctica, basada en los principios, pautas y puntos de verificación del DUA, que consistió en tres actividades realizadas en cuatro sesiones de clase. Finalmente, se aplicó un pos-test, con igual estructura y criterios de evaluación del pre-test.
El análisis del desempeño de los estudiantes y su nivel de algebrización en la resolución de PAV, antes y después de la implementación de la secuencia didáctica, permitió evidenciar los avances de los estudiantes en la comprensión, elaboración de un plan, ejecución y verificación de la solución de un PAV. Además, los resultados obtenidos mostraron mejoras en el nivel de algebrización de la mayor parte de los estudiantes. Esto permitió concluir que el DUA es una metodología de diseño adecuada para planear y poner en marcha estrategias didácticas que busquen mejorar el desempeño en resolución de PAV y los niveles de algebrización de los estudiantes. Así mismo, se evidenció que una estrategia basada en el DUA promueve la educación inclusiva que atiende la diversidad.Magíster en Educación Inclusiva e InterculturalMaestríaThis research proposes the design and implementation of a teaching strategy, based on the Universal Design for Learning (UDL), to improve the skills in solving verbal algebraic problems in eighth grade students of the Educational Institution 'Diego de Torres'. The methodological design is based on the critical paradigm and consists of a quasi-experimental study without a control group. To characterize the cognitive, procedural and attitudinal skills of the students around solving mathematical problems, an affective domain questionnaire and a pre-test were applied. The questionnaire addressed students' beliefs, emotions, and attitudes toward mathematical problem solving. The pre-test evaluated the processes carried out by students when solving verbal mathematical problems (VMP), based on the steps of the Pòlya method: understand, plan, solve and verify. Also, the pre-test served to establish the level of algebrization of each student. According to the results, a didactic sequence was designed, based on the principles, guidelines and verification points of the DUA, which consisted of three activities carried out in four class sessions. Finally, a post-test was applied, with the same structure and evaluation criteria as the pre-test.
The analysis of the students' performance and their level of algebraization in solving PAV, before and after the implementation of the didactic sequence, allowed us to demonstrate the students' progress in understanding, developing a plan, executing and verifying the solution of a PAV. Furthermore, the results obtained showed improvements in the level of algebraization of most of the students. This allowed us to conclude that the DUA is an appropriate design methodology to plan and implement didactic strategies that seek to improve performance in VMP resolution and the algebraization levels of students. Likewise, it was evident that a strategy based on UDL promotes inclusive education that addresses diversity
Impact of the diversification of SARS-CoV-2 variants during the COVID-19 pandemic in Colombia against the escape of neutralizing antibodies generated by natural and vaccine immunity
No full textilustraciones, diagramasLa vigilancia genómica del SARS-CoV-2 en Colombia permitió identificar la importación y emergencia autóctona de variantes de preocupación (VOC) o de interés (VOI) del SARS-CoV-2 con mutaciones asociadas al escape inmunológico o resistencia a la acción de los anticuerpos neutralizantes (nAbs) generados por infección natural o vacunación. Las vacunas contra el COVID-19 autorizadas en Colombia fueron diseñadas antes de la emergencia de las VOC/VOI, por lo que este estudio se enfocó en evaluar la capacidad de las variantes locales para escapar a los nAbs inducidos por la vacunación. Se realizaron aislamientos de linajes del SARS-CoV-2 que circularon durante los años 2020-2022 en Colombia. Se evaluaron las respuestas de los nAbs en individuos convalecientes, individuos no expuestos al SARS-CoV-2 (naïve) con esquemas primarios de CoronaVac, BNT162b2, ChAdOx1 o Ad26.COV2.S, en individuos con refuerzo homólogo, heterólogo e individuos con inmunidad híbrida-heteróloga. Las respuestas de los nAbs se evaluaron mediante ensayos de neutralización y el título medio de neutralización (MN50) se calculó por el método de Reed-Muench. Finalmente, se evaluaron anticuerpos totales IgM/IgG contra los antígenos S1, S2, RBD y contra la proteína N del SARS-CoV-2, en individuos con inmunidad heteróloga e híbrida-heteróloga mediante paneles Luminex. El linaje B.1 con la mutación E484K demostró capacidad moderada de escape a nAbs de sueros convalecientes, mientras que los niveles de nAbs fueron entre 3,3 a 55 veces menores contra Mu, Delta y Ómicron, comparado con B.1.111 y Gamma en individuos naïve con vacunación primaria. Además, las respuestas de los nAbs contra Mu y Ómicron fueron significativamente mayores tras el refuerzo heterólogo comparado con el esquema primario u homólogo. Finalmente, no se observaron diferencias en los niveles de nAbs contra Ómicron y anticuerpos IgG contra la subunidad S1 y el RBD entre individuos con inmunidad heteróloga e híbrida-heteróloga. Los resultados sugieren que el refuerzo heterólogo rescata las respuestas neutralizantes contra VOI/VOCs a niveles comparables con individuos que presentan inmunidad híbrida. (Texto tomado de la fuente)Genomic surveillance of SARS-CoV-2 in Colombia allowed us to identify the importation and autochthonous emergence of variants of concern (VOC) or of interest" (VOI) of SARS-CoV-2 with mutations associated with the escape of neutralizing antibodies (nAbs) generated by natural infection or vaccination Vaccines against COVID-19 authorized in Colombia were designed before the emergence of VOCs/VOIs, so this study sought to assess the ability of local variants to escape vaccination-induced nAbs. Isolations of SARS-CoV-2 lineages circulating in Colombia were performed between 2020 and 2022. The nAbs responses were evaluated in convalescent individuals, individuals with no history of previous SARS-CoV-2 infection (naïve), individuals with primary schemes of CoronaVac, BNT162b2, ChAdOx1, or Ad26.COV2.S, individuals with homologous, heterologous boost, and individuals with hybrid-heterologous immunity. nAbs responses were assessed by neutralization assays and the mean neutralization titer (MN50) was calculated by the Reed-Muench method. Finally, total IgM/IgG antibodies against the S1, S2, RBD, and N antigens of SARS-CoV-2 were evaluated in individuals with heterologous and hybrid-heterologous immunity using Luminex panels. The B.1 lineage with the E484K mutation demonstrated moderate escape capacity to nAbs from convalescent sera, while nAbs levels were 3.3 to 55-fold lower against Mu, Delta, and Omicron, compared to B.1.111 and Gamma in naïve individuals with primary vaccination. In addition, nAb responses against Mu and Omicron were significantly higher after heterologous boost compared to the primary or homologous regimen. Finally, no differences were observed in the levels of nAbs against Omicron and IgG antibodies against the S1 and the RBD antigens between individuals with heterologous and hybrid-heterologous immunity. The results suggest that heterologous boosting rescues neutralizing responses against VOI/VOCs at levels comparable to individuals with hybrid immunity.DoctoradoDoctor en Ciencias - Biologí
Digestibilidad aparente de ingredientes vegetales en la cachama blanca (Piaractus orinoquensis)
No full textEl presente trabajo evaluó la digestibilidad aparente de diferentes ingredientes vegetales empleados en la alimentación de la cachama blanca (Piaractus orinoquensis), con el propósito de identificar fuentes proteicas y energéticas alternativas al uso de harinas de origen animal. Se utilizaron seis ingredientes vegetales: frijol caupí (Vigna unguiculata), torta de soya (Glycine max), maíz amarillo (Zea mays), plátano (Musa paradisíaca), yuca (Manihot esculenta) y hoja de matarratón (Gliricidia sepium). Cada harina se incorporó al 30% en una dieta experimental, complementada con una dieta de referencia comercial (69%) y un marcador inerte (Cr₂O₃, 1%) para determinar los coeficientes de digestibilidad aparente (CDA) de materia seca, proteína bruta y energía bruta.
Los resultados mostraron diferencias significativas entre los ingredientes evaluados. La harina de maíz amarillo (DHMA) y la de frijol caupí (DHFC-50) registraron los mayores valores de energía y proteína digestible, evidenciando una mejor eficiencia en el aprovechamiento de nutrientes. En contraste, las harinas de plátano (DHP) y yuca (DHY) presentaron los valores más bajos de proteína y energía digestible, lo que limita su uso como ingredientes principales en las dietas. La harina de torta de soya (DHTS) se destacó por combinar buena digestibilidad y adecuado contenido proteico, constituyendo una opción estable como fuente de proteína vegetal.
Se concluye que la incorporación de ingredientes vegetales locales como el maíz y el frijol caupí puede contribuir al desarrollo de dietas más sostenibles y económicas para la cachama blanca, sin comprometer su valor nutricional. Los resultados obtenidos constituyen una base técnica para la formulación de alimentos balanceados que favorezcan la sustitución parcial de la harina de pescado, promoviendo una acuicultura más sustentable en la región Caribe colombiana.The present study evaluated the apparent digestibility of different plant-based ingredients used in the feeding of the white cachama (Piaractus orinoquensis), with the purpose of identifying alternative protein and energy sources to replace animal-derived meals. Six plant ingredients were used: cowpea (Vigna unguiculata), soybean meal (Glycine max), yellow corn (Zea mays), plantain (Musa paradisiaca), cassava (Manihot esculenta), and madre de cacao leaves (Gliricidia sepium). Each ingredient was incorporated at 30% into an experimental diet, complemented with a commercial reference diet (69%) and an inert marker (Cr₂O₃, 1%) to determine the apparent digestibility coefficients (ADC) of dry matter, crude protein, and gross energy.
The results showed significant differences among the evaluated ingredients. Yellow corn meal (DHMA) and cowpea meal (DHFC-50) recorded the highest values of digestible energy and protein, demonstrating better nutrient utilization efficiency. In contrast, plantain (DHP) and cassava (DHY) meals presented the lowest digestible protein and energy values, which limits their use as main ingredients in the diets. Soybean meal (DHTS) stood out for combining good digestibility and adequate protein content, representing a stable option as a plant protein source.
It is concluded that the inclusion of local plant ingredients such as corn and cowpea can contribute to the development of more sustainable and economical diets for white cachama, without compromising its nutritional value. The results obtained provide a technical basis for the formulation of balanced feeds that promote the partial replacement of fishmeal, supporting a more sustainable aquaculture in the Colombian Caribbean region.Lista de figuraLista de tablasRESUMENINTRODUCCIÓNOBJETIVOSObjetivo generalObjetivos especificosMarco teoricoGeneralidades y habitos alimenticiosIngredientes vegetalesFrijol caupí (Vigna unguiculata L. Walp)Matarratón (Gliricidia sepium)Maíz (Zea mays)Plátano (Mussa paradisíaca)Torta de soya (Glycine max)Yuca (Manihot esculenta)Digestibilidad de materias primas usadas en acuiculturaDeterminación del coeficiente de digestibilidadMATERIALES Y MÉTODOSLocalizaciónDietas con ingredientes vegetalesMaterial biológico y manejoDeterminación de la composición proximal de los ingredientesDiseño experimental y análisis estadísticoRESULTADOS Y DISCUSIÓNParámetros de calidad de aguaComposición proximal de los ingredientes vegetalesCoeficiente de digestibilidad aparente de ingredientes y dietas experimentalesRelación entre PB y EDCONCLUSIONESRECOMENDACIONESREFERENCIAS BIBLIOGRAFÍAABSTRACTPregradoProfesional en AcuiculturaTrabajos de Investigación y/o Extensió
