Correlation of students’ previous ideas in Earth Sciences at european and international level

El objeto de este trabajo es comparar las ideas previas sobre algunos aspectos de las Ciencias de la Tierra de los estudiantes de la Facultad de Ciencias de la Educación de la Universidad de Sevilla con las de niños y futuros maestros de otros países europeos, con la finalidad de encontrar los principales obstáculos de aprendizaje y proponer alternativas didácticas para superarlos

International collaboration projects among teachers in the field of Earth Sciences

Las Ciencias de la Tierra tienen una escasa representación en la enseñanza obligatoria. Los profesores, en su mayoría faltos de formación, se sienten inseguros en su actividad diaria. El objeto de este trabajo es presentar una serie de programas internacionales surgidos con el deseo de apoyar al profesorado de Ciencias de la Tierra para dinamizar y mejorar la práctica docente, así como aumentar el interés de los alumnos por el conocimiento del planeta. Se analizan, en particular, el portal XPLORA, de ámbito europeo, el proyecto GLOBE, de ámbito internacional, y el ESSEA de ámbito estadounidense

Nota sobre la presencia de mineralizaciones de barita al sur de Llerena (Badajoz, España)

Barite mineralizations occur within Lower Cambrian detrital-carbonatic materials in the Zafra-Monesterio sector (Ossa-Morena zone, Iberian Massif), mainly associated to shales containing siliceous limestones layers. Four types of mineralization can be differentiated: 1) disseminate barite in carbonatic rocks, 2) centimetric concretions, 3) stratiform bodies of up 50 m long and <2 m thick, and 4) veins which are filling post-Hercynian fractures. According to the geological setting, and morphological, mineralogical and chemical characteristics a sedimentary and/or diagenetic origin may be supposed for stratiform barite deposits. Barite recrystallization took place during Hercynian deformation. Later barite was remobilized and concentrated in post-Hercynian fractures. Stratiform mineralizations described above can be considered of a commercial interest because occurrences are very abundant in this area, and grades are many times richer than 90% of BaS04with only silica as the major impurity.Las mineralizaciones estratiformes de barita aparecen asociadas a un conjunto de materiales detrítico-carbonatados de edad Cámbrico inferior en el denominado Dominio de Zafra-Monesterio (Zona de Ossa- Morena), encajando en pizarras con niveles de calizas con sílex, que presentan frecuentes cambios laterales de facies. Se pueden distinguir varios tipos de mineralizaciones: 1) barita diseminada en las rocas carbonatadas, 2) barita en concrecciones centimétricas, 3) barita en niveles estratiformes de hasta 50 m de longitud y espesores inferiores a 2 m, y 4) baritas con morfología filoniana que rellenan fracturas posthercínicas. Atendiendo a las características del entorno geológico y a las consideraciones morfológicas, mineralógicas y químicas, es posible asignar a estas mineralizaciones un origen sedimentario y/o diagenètico, con recristalizaciones durante las etapas de deformación hercínica (tipos 1, 2 y 3). Posteriormente la barita ha sido removilizada y depositada en fracturas posthercínicas (tipo 4). Las mineralizaciones estratiformes descritas pueden ser de interés económico, ya que en la zona aparecen frecuentes indicios de este tipo que alcanzan leyes superiores al 90%, con sílice como impurezas más significativa

Research on abiotic resources in the recent prehistory in Tierra de Barros and Western Sierra Morena

En este trabajo se presentan las investigaciones de base arqueométrica que se están llevando a cabo con objeto de conocer los sistemas de abastecimiento de recursos abióticos de las comunidades del III y II milenio ANE en los territorios de Tierra de Barros (Badajoz) y Sierra Morena occidental (Huelva y Sevilla), a partir del análisis de artefactos elaborados con arcilla, rocas y rocas metalíferas, procedentes de contextos habitacionales y funerarios de excavaciones y prospecciones arqueológicas. Otros análisis, entre los que se incluyen los de Isótopos de Plomo, se realizan sobre muestras de materias primas obtenidas en las prospecciones geológicas del entorno, con la finalidad de establecer la relación de procedencia de los objetos manufacturados y los depósitos de los que se obtuvo el mineralIn this work the archaeometric-based research being carried out on abiotic procurement systems of the communities of the 3rd and 2nd millennia BC in the regions of Tierra de Barros (Badajoz) and West Sierra Morena (Huelva and Sevilla), gained from analyses of artefacts made of ceramic, rocks and metals, recovered from funerary and habitational contexts through archaeological surveys and excavations, is presented. Other analyses, among them Lead Isotopes, have been done on raw material samples obtained by geological surveys in the surrounding areas, with the aim of establishing the relationship of provenance between the manufactured objects and the deposits where the raw materials were obtained fromMinisterio de Educación y Ciencia MAT2005-0079

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Alambique : didáctica de las ciencias experimentales

resumen extractado del artículoEn este trabajo se realiza una breve revisión sobre los distintos tipos y posibilidades de trabajos prácticas en relacion con los contenidos geológicos de los currículos de primaria y secundaria. El diseño, la selección y la secuenciación de los mismos, su relevancia como actividades de motivación, aplicación, síntesis, es decir su finalidad didáctica que dependerá de la decisión del profesorado en su contexto de enseñanza y aprendizaje.CataluñaUniversidad de Valladolid. Facultad de Educación. Biblioteca; Calle Geólogo Francisco Hernández Pacheco, s-n; 47014 Valladolid; Tel. +34983423435; Fax +34983423436; [email protected]

Quartz as votive and building material within the megalithic funerary complex

Este trabajo examina un conjunto de objetos de cuarzo, tales como monocristales (variedades cristal de roca y prasio) y cantos rodados, encontrados en dos contextos arqueológicos espacial y cronológicamente distintos del complejo megalítico de Palacio III (Almadén de la Plata, Sevilla), excavado por las universidades de Sevilla y Southampton entre 2001 y 2002. Estos objetos se describen, en primer lugar, desde un punto de vista macroscópico atendiendo a sus características mineralógicas y cristalográficas. Se han utilizado técnicas difractométricas y de microscopía electrónica de barrido sobre las muestras inalteradas para determinar su composición mineralógica y química. A continuación se listan y describen casos de ítems semejantes registrados en contextos funerarios de la Prehistoria Reciente del Sur de la Península Ibérica. Finalmente se valoran distintas interpretaciones para los mismos, desde un punto de vista tanto funcional como simbólico, discutiéndose el significado de su presencia dentro de contextos espacialmente distintos y crono-culturalmente distantes.This paper examines an assemblage of quartz objects, such as crystals (rock crystal and prase) and pebbles, that were found in two spatially and chronologically different contexts of the Palacio III megalithic complex (Almadén de la Plata, Seville, Spain) excavated by the universities of Seville and Southampton between 2001 and 2002. Firstly, these objects are described macroscopically from a mineralogical and crystallographic point of view. When possible, samples are studied by X-ray diffraction and SEM in order to determine their mineralogical and chemical composition. Secondly, other similar instances, in which quartz and rock crystal objects have been found among the grave goods of funerary contexts of southern Iberian, are described. Finally, we propose a series of interpretations for these objects, both from a functional as well as a symbolical perspective, assessing the significance of their presence in spatially discrete and chrono-culturally distant contexts

Las estelas de guerrero de Almadén de la Plata (Sevilla). Morfología, tecnología y contexto

This paper presents a study of two prehistoric ‘warrior’ stelae found in the north of the province of Sevilla (Andalusia, Spain) in November 2004. The circumstances of both discoveries – within a clearance cairn – are described, and both are categorised and analysed from various perspectives: their morphology, the symbolism of the figures and weapons represented and their petrology are each discussed. Although they are almost certainly a late Bronze Age phenomenon, little is known of the original context of warrior stelae, which are almost always found in secondary contexts. In this case, the spatial and territorial context of the find was investigated through both a magnetometer survey and a novel form of surface collection employing RTK GPS rovers for geolocation. Although the magnetometer survey revealed no features of interest, the use of GPS for the surface survey permitted the accurate registration of a scatter of quartzite pebbles around the clearance cairn, and clearly focussed on it. Quartzite is known to have been employed in megalithic constructions in other parts of the same region, and in the absence of another obvious explanation for this scatter, the authors suggest the possibility that the original context for these stelae may now be beneath the cairn, which possibly began life as a focus of prehistoric activity that included the use of the stelae during the late Bronze Age, and ended with the formation of the clearance cairn itself. The survey was undertaken by a joint team from the Universities of Southampton and the University of Sevilla, which has been carrying out in western Sierra Morena since the late 1980s, and builds on a previous collaboration between these authors, the Melonares Survey which was undertaken between 1999 and 2001