363 research outputs found
Features and Origin of Red Clays in Castafiar Cave: A Touch of Colour
In Castaiiar Cave (Caceres, Spain), coatings of red clays cover the walls
of the chambers, coexisting with diverse speleothems of aragonite, calcite, huntite
and dolomite. The mineralogy of the clays is mainly illite, chlorite, kaolinite, smectite,
quartz and Fe oxides and hydroxides such as goethite. They can be transported
into the cave by infiltration waters or form by in situ alteration of the host rock: layers
of dolomite rich in Fe and magnesite interbedded with greywackes and shales.
Present-day hydrological conditions in the cave and conditions during the formation
of speleothems have determined that the clays have not been transported by any
flooding or seepage, but mostly staying in situ, and not included into carbonate crystal
forms . Thus, most of the well-preserved speleothems are white and not stained,
conforming an interesting chromatic contrast with the red clays that represent an
additional attraction in this show cave
Validación de un cuestionario para evaluar el funcionamiento de las bibliotecas escolares
The school library has acquired a new prominence in recent years, becoming a fundamental learning space for the teaching of different areas and subjects and the promotion of skills in students.The objective of this work is to validate a questionnaire designed ad hoc to evaluate the functioning and the forms of use and incorporation of the school library to the daily pedagogical activity. To this purpose, the questionnaire was applied to a random sampling of 4,177 students from 358 centers of Primary, Secondary and Post-Compulsory Education, reliability was calculated using the Cronbach's Alpha test and an exploratory factor analysis was carried out. The results show that the Students Questionnaire to Evaluate the Operation of the School Library has acceptable levels of reliability and validity, so that it offers guarantees enough to evaluate the functioning of the school library
Improvement of the lubrication performance of an ester base oil with coated ferrite nanoadditives for different material pairs
In the present work, lubrication properties (friction and wear) of a synthetic ester oil, tris(2-ethylhexyl) trimellitate (TOTM) containing ferrite nanoparticles coated with oleic acid (F3O4-OA) were investigated for two different material pairs: steel ball-steel disc and silicon nitride ball-steel disc. Thus, four TOTM nanolubricants were formulated: TOTM + 0.010 wt% Fe3O4-OA, TOTM + 0.015 wt% Fe3O4-OA, TOTM + 0.020 wt% Fe3O4-OA and TOTM + 0.025 wt% Fe3O4-OA showing all of them a moderate time stability due to the oleic acid coating. Wettability behaviour of the ferrite-based nanolubricants on steel surface was analysed, revealing that the addition of Fe3O4-OA nanoparticles in TOTM decreases the contact angle between the steel surface and TOTM lubricant surface. Friction sliding tests were performed with the neat TOTM and with the formulated nanolubricants under a 20 N of load. All nanolubricants showed lower coefficients of friction than those reached with TOTM base oil for both material pairs. Worn area was significantly reduced for all Fe3O4-OA concentrations in the steel-steel contact and for the highest concentrations in the silicon nitride-steel contact. Specifically, the largest achieved reductions were for the TOTM + 0.010 wt% F3O4-OA nanolubricant: 43% reduction in friction (silicon nitride-steel) and reductions of 17% in wear track width, 42% in wear track deep and 36% in area (steel-steel). In addition, roughness analysis and Raman microscopy of the tested discs showed that tribofilm formation and surface repairing mechanisms occurThe following institutions and grants are acknowledged for funding this research: Government of Spain Ministry of Economy and Competitiveness (grant numbers: ENE2017-86425-C2-2-R and PID2020-112846RB-C22 projects) and Xunta de Galicia (Spain) (grant number: GRC ED431C 2020/10)S
Estudios de caso. El desarrollo de competencias en la formación inicial de docentes en Andalucía después de Bolonia (EEES). Facultad de Ciencias de la Educación (Universidad de Huelva)
Esta colección tiene una serie de informes generales y 8 estudios de casos. Este volumen es el informe del Estudio de casos desarrollado en la Facultad de Ciencias de la Educación de la Universidad de Sevilla.
Todos los autores y autoras de este documento autorizan a Encarnación Soto Gómez a depositarlo en RIUMA.Los hallazgos de esta investigación se recogen en diferentes informes que componen una mirada compleja y contrastada a la
formación inicial de Andalucía en el Grado de Educación Infantil y Educación Primaria 10 años después de la puesta en marcha
del Espacio Europeo de Educación Superior y 30 años después de la investigación desarrollada por el mismo Grupo de investigación: (1991-1993) del Plan Nacional de Investigación “Las prácticas de enseñanza en la formación inicial en las escuelas
universitarias de formación de profesorado de Andalucía” (PB90-0813). La colección se compone de:
• Un informe documental de las estructuras, condiciones y planes de estudio de las 8 Facultades implicadas.
• Un informe de grandes muestras recogiendo la opinión de estudiantes y profesorado implicado en cada uno de los Títulos
• 8 estudios de caso, uno por cada una de las Facultades implicadas.
Investigadores principales:
Ángel I. Pérez y Encarna Soto
Investigadores:
Noelia Alcaraz; Javier Barquin; Nieves Blanco; Ester Caparrós; Soledad de la Blanca; Manuel Fernandez; Isabel Fernández; Monsalud Gallardo; Elena García; Rosario Gutíerrez; Gonzalo Maldonado; Diego Martín; Ana Márquez; Mª Jose Mayorga; Laura; Muñoz; Laura Pañagua; Noemí Peña; Laura Pérez; Cristina Rodríguez; Mª del Pilar Sepúlveda; Mª José Serván; Eduardo SierraProyecto de investigación financiado: UMA18-FEDERJA-127. El desarrollo de competencias en la formación inicial de docentes en
Andalucía después de Bolonia (EEES). Un estudio comparativo 25 años después. Grupo de Investigación HUM 311. Web. http://repensarlaeducacion.e
Anlysis using geographical information system in the city of Cartagena
[SPA] A partir de un listado de edificaciones modernistas de la ciudad de Cartagena, y mediante el empleo de Sistemas de Información Geográfica,
se realizan los mapas temáticos en función de diferentes variables mostrando cartográficamente los arquitectos que los realizaron,los usos
para los que se proyectaron o el grado de catalogación actual de los mismos, que pueden relacionarse con las principales rutas modernistas
de la ciudad.
A partir del estudio espacial de la ubicación de los edificios seleccionados aparecen dos ejes de concentración de los mismos, muy bien
diferenciados, que coinciden con los principales ejes de la ciudad amurallada: el eje Norte-Sur entre la puerta de Madrid y la del Muelle, que
continua extramuros en la misma dirección en las casas baratas y el otro eje fundamental Oeste-Este, que coincide con el eje de la puerta de
San José, que también continúa extramuros con la estación de ferrocarril.
Este estudio es susceptible de incorporarse a un geoportal siendo este la herramienta óptima para la difusión y conocimiento de la información
obtenida sobre el modernismo en la ciudad.
[ENG] Based on a list of art nouveau buildings on Cartagena, and using Geographic Information Systems, we have made thematic maps rooted in different
variables, cartographically showing the architects who created them, current uses and the degree of cataloging, which may relate with the modernist
routes of the city.
From the study of the location of selected buildings we can observe two axes of concentration of buildings, which coincide with the principal axes of the
walled city: the North-South axis from the Puerta de Madrid toPuerta del Muelle, which continues outside the walls in the same direction at Casas Baratas
and other main West-East, which coincides with the axis of the Puerta de San Jose, which also continues outside the walls until the railway station.
This study is sensitive to join a geoportal as an optimal tool for dissemination and knowledge of information obtained on modernism in the Cartagena
Defective Adaption of Erythrocytes During Acute Hypoxia Injury in an Elderly Population
The present study investigated the changes in several erythrocyte oxidative stress biomarkers in hypoxic elderly individuals to analyze the deleterious effects of low oxyhemoglobin saturation in an elderly population. We collected blood samples from one normoxic middle-aged group and two groups composed of individuals older than 75 years of age: one normoxic group and one hypoxic group. Aging appeared to provoke a defective erythrocyte antioxidant defense associated with increased oxidative damage in the elderly population. Acute hypoxia activated an insufficient antioxidant defense response as suggested by the oxidative damage observed. The oxidative imbalance presented in older participants and increased in hypoxia participants had a direct effect on glyceraldehyde-3-phosphate dehydrogenase cell distribution. Oxidative stress levels altered Band 3 protein and mediated caspase-3 activation in erythrocyte from the aged group although it was not extended to hypoxic individuals. Therefore, aged participants appeared to activate an insufficient antioxidant response against hypoxia-related oxidative stress.Instituto Carlos III (FISS-06-RD06/0013/0011); Ministerio de Agricultura and FEDER (INIA RTA2007-00087-C02-02); FICYT (Gobierno del Principado de Asturias) (IB09-134)
Aproximación al cálculo de los constantes de disociación de ácidos aminotricarboxílicos: determinación de los valores de pKa del ácido nitrilotripropiónico
Se propone una aproximación para el cálculo de los valores de pKa de ácidos aminotricarboxílicos, por la que pKo, pK1 y pK2 se determinan por tratamiento de mínimos cuadrados y, después, pK3 se obtiene algebráicamente. Se ilustra la utilidad de esta aproximación por su aplicación al cálculo de los pKa del ácido nitrilotripropiónico.An approximation to evaluate the pK. values of aminotricarboxylic acids
is proposed. By least square treatements, the values of pKo, pKI and pK2 are
obtained; then, pK3 is found by algebraic calculations. The evaluations of pKo
of nitrilotripropionic acid is used to ilustrate the utility of the aboye approximation
Aproximación al cálculo de las constantes de disociación de ácidos aminotricarboxílicos: determinación de los valores de pKa del ácido nitrilotripropiónico
Se propone una aproximación para el cálculo de los valores de pK de ácidos aminotricarboxílicos, por la que pK0 pK1 y pK2 se determinan por tratamiento de mínimos cuadrados y, después, pK3 se obtiene algebraicamente. Se ilustra la utilidad de esta aproximación por su aplicación al cálculo de los pKa del ácido nitrilotripropiónico.An approximation to evaluate the pK. values of aminotricarboxylic
acids is proposed. By least square treatements, the values of pK o' pK \ and pK 2
are obtained; then, pK 3 is found by algebraic ca\culations. The evaluation of
pK. of nitrilotripropionic acid used to ilustrate the utility of the above approximation
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An upgrade on the rabbit model of anthracycline-induced cardiomyopathy: shorter protocol, reduced mortality, and higher incidence of overt dilated cardiomyopathy
Current protocols of anthracycline-induced cardiomyopathy in rabbits present with high premature mortality and nephrotoxicity, thus rendering them unsuitable for studies requiring long-term functional evaluation of myocardial function (e.g., stem cell therapy). We compared two previously described protocols to an in-house developed protocol in three groups: Group DOX2 received doxorubicin 2 mg/kg/week (8 weeks); Group DAU3 received daunorubicin 3 mg/kg/week (10 weeks); and Group DAU4 received daunorubicin 4 mg/kg/week (6 weeks). A cohort of rabbits received saline (control). Results of blood tests, cardiac troponin I, echocardiography, and histopathology were analysed. Whilst DOX2 and DAU3 rabbits showed high premature mortality (50% and 33%, resp.), DAU4 rabbits showed 7.6% premature mortality. None of DOX2 rabbits developed overt dilated cardiomyopathy; 66% of DAU3 rabbits developed overt dilated cardiomyopathy and quickly progressed to severe congestive heart failure. Interestingly, 92% of DAU4 rabbits showed overt dilated cardiomyopathy and 67% developed congestive heart failure exhibiting stable disease. DOX2 and DAU3 rabbits showed alterations of renal function, with DAU3 also exhibiting hepatic function compromise. Thus, a shortened protocol of anthracycline-induced cardiomyopathy as in DAU4 group results in high incidence of overt dilated cardiomyopathy, which insidiously progressed to congestive heart failure, associated to reduced systemic compromise and very low premature mortality
Clasificación preliminar de especies de jardín según sus requerimientos hídricos en la región de Murcia
El desarrollo económico y social de la Región de Murcia ha conllevado desde la
década de los 80 un considerable aumento de la superficie ajardinada, tanto de carácter
público como privado. Esta circunstancia, unida a los graves problemas de escasez de
agua, pone de manifiesto la importancia del establecimiento de jardines de bajo consumo
hídrico.Este trabajo forma parte del proyecto de investigación regional PR02-03-2 financiado
por la Dirección General de Investigación y Transferencia Tecnológica
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