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En el presente estudio se analizan las prácticas de aula del especialista de atención a la diversidad en los centros de educación infantil y primaria (CEIP) de Andalucía. Mediante un diseño de naturaleza cualitativa de carácter transversal, se obtienen los datos con dos fuentes principales de información (entrevista semiestructurada diseñada ad hoc y observación directa y no participante) sobre una muestra de 142 especialistas. Los resultados revelan el desarrollo de prácticas inclusivas respecto al uso de estrategias didácticas y metodologías activas; la importancia de recursos plurales y funcionales; la puesta en práctica de un apoyo pedagógico coordinado o colaborativo, y la flexibilización en la dinámica y la organización de aula. También se identifican posibilidades, dificultades y limitaciones. Las conclusiones apuntan que las prácticas que están desarrollando los especialistas pretenden contribuir a la mejora de las escuelas en relación con la atención a la diversidad, siendo el apoyo colaborativo a la comunidad educativa la función principal para la promoción de una escuela inclusiva que atienda a todo el alumnado. En el present estudi s'hi analitzen les pràctiques d'aula de l'especialista d'atenció a la diversitat als centres d'educació infantil i primària (CEIP) d'Andalusia. Mitjançant un disseny de naturalesa qualitativa de caràcter transversal, s'obtenen les dades a partir de dues fonts principals d'informació (entrevista semiestructurada dissenyada ad hoc i observació directa i no participant) sobre una mostra de 142 especialistes. Els resultats revelen el desenvolupament de pràctiques inclusives respecte a l'ús d'estratègies didàctiques i metodologies actives; la importància de recursos plurals i funcionals; la posada en pràctica d'un suport pedagògic coordinat o col·laboratiu, i la flexibilització en la dinàmica i l'organització d'aula. També s'hi identifiquen possibilitats, dificultats i limitacions. Les conclusions apunten al fet que les pràctiques que estan desenvolupant els especialistes pretenen contribuir a millorar les escoles en relació amb l'atenció a la diversitat, de manera que el suport col·laboratiu a la comunitat educativa esdevé la funció principal per promoure una escola inclusiva que atengui tot l'alumnat. This research analyzes the classroom practices of diversity care specialists in early childhood and primary education schools of Andalusia. A cross-sectional qualitative design was used to obtain data from two main sources: a semi-structured interview designed ad hoc and direct and non-participant observation with a sample of 142 participants. The results reveal the development of inclusive practices regarding the use of didactic strategies and active methodologies, the importance of plural and functional resources, the implementation of coordinated or collaborative pedagogical support, and flexibility in the dynamics and organization of the classroom. Opportunities, difficulties, and limitations are also identified. The conclusions indicate that the practices being developed by these specialists aim to contribute to improving schools in relation to attention to diversity, with collaborative support for the educational community being the main function for the promotion of an inclusive school that attends to all students.

Con cierta frecuencia, la escuela rural suele ser la primera experiencia como maestro. No obstante, los planes de estudio de las titulaciones que dan acceso al ejercicio de la docencia no suelen reflejar formación específica sobre esta temática, exceptuando alguna asignatura puntual de carácter optativo. En este sentido, se planteó un análisis documental con el propósito de analizar la introducción de la escuela rural en las guías docentes de los Grados de Educación Infantil y de los Grados de Educación Primaria en el contexto español (2 224 guías analizadas). Los resultados mostraron que la formación adquirida en la universidad no garantiza la especificidad de competencias para este tipo de centros educativos a la hora de afrontar una organización y funcionamiento distintos al de la escuela mayoritaria (urbana). Las conclusiones recogen la escasa presencia de la escuela rural en los planes de formación del futuro profesorado, tanto en lo que respecta a la oferta de materias disciplinares concretas como en otras con un carácter más transversal., Rural schools are often the first experience of teaching. However, the curricula of the qualifications that give access to teaching do not usually reflect specific training around this topic, except in some specific optional subjects. In this sense, a documentary analysis was developed with the purpose of analyzing the introduction of rural schools in the teaching guides of Early Childhood Degrees and Primary Education Degrees in the Spanish context (2 224 documents analyzed). The results showed that the training acquired at university does not guarantee the specificity of skills for this type of school when facing an organization and operation different from that of the majority urban school. The conclusions indicate the scarce presence of rural schools in the training plans of future teachers, both with regard to the offer of specific disciplinary subjects and in others with a more transversal character.

La literatura científica sobre el profesorado de la etapa de educación infantil, evidencia que existen múltiples modelos para la gestión del aula que llevan asociadas diversas estrategias didáctico-pedagógicas: desde modelos próximos a estilos directivos (predominantes en el contexto español) a otros en los que prevalece el tiempo no planificado o libre. La investigación parte de la opinión de 1.350 docentes de Educación Infantil de la Comunidad Autónoma de Andalucía (España) sustentada en los principios del método positivista, con una intención exploratoria y de correlación. A partir de un cuestionario diseñado ad hoc, este estudio se propone identificar y explorar las posibles correlaciones existentes entre los aspectos metodológicos-organizativos y su influencia o grado de determinación en las interacciones que surgen en el aula. Los resultados obtenidos tras un análisis de ecuaciones estructurales, permiten confirmar, la influencia positiva de determinados aspectos metodológicos-organizativos desarrollados por el docente, sobre el tipo de interacciones que resultan durante el trabajo por rincones en el aula de educación infantil. Las conclusiones muestran que para dinamizar el ambiente del aula es preciso: diversificar los aspectos metodológico-organizativos que acompañan a la labor docente, superando así las reticencias detectadas en parte del profesorado, e invitar a reflexionar sobre la formación en actitudes positivas hacia el cambio y la mejora educativa. Research focused on ECE (Early Childhood Education) stage teachers brings to light multiple models for classroom management associated with different didactic-pedagogical strategies, ranging from models close to management styles (predominant in the Spanish context) to others in which unplanned or free time predominates. Our investigation is based on the opinion of 1.350 ECE teachers in Andalusia (Spain) on positivist method principles, with an exploratory and correlational intention and the support of an ad hoc designed questionnaire, we try to identify and explore the possible correlations between methodological-organisational aspects, as well as their influence or degree of determination on the interactions that take place in the ECE classroom. The results obtained after a structural equations analysis confirmed the positive influence of some methodological-organisational aspects implemented by the teacher on the type of interactions that arise when working with learning corners in the ECE. We conclude that in order to dynamise the classroom environment it is necessary to diversify the methodological-organisational aspects that accompany teaching work, overcoming the reluctance detected in part of the teaching staff and inviting them to reflect upon training in positive attitudes towards change.

Resumen: La escuela rural es unarealidad en los cinco continentes, con rasgos característicos propios, aunque muy influenciables por las políticas educativas que se implementan en los diferentes países. En este estudio nos preguntamos cuál es el estado de la investigación sobre la política escolar rural a nivel internacional, para lo que realizamos un análisis bibliométrico de los artículos científicos publicados en los últimos veinte años. Los resultados revelan la existencia de 20 estudios, en los que examinamos las propensionesinvestigadoras y las políticas analizadas.Identificamosuna clara tendencia de investigación: predominio de estudios cualitativos dirigidos a examinar políticas que se están implementando con participación del profesorado. Asimismo, las políticas educativas examinadas se inician en el ámbito de la salud y el curriculum,y se han ido diversificando hacia la gestión escolar, las políticas nacionales y supranacionales y la equidad. Cabe concluir que estamos ante un campo incipiente como objeto de estudio en el que están apareciendo diferentes estudios disgregados que no revelan cuáles son las principalespolíticas a asumir en las escuelas rurales para que puedan desarrollaruna identidady autonomíapropia. Abstract: Rural schools are a reality on all five continents, with their own characteristic features, although they are highly influenced by the educational policies implemented in the different countries. In this study we examine the state of research on rural school policy at the international level through a bibliometric analysis of scientific articles published in the last 20 years. The results show the existence of 20 studies, from which we analyse research trends and policies. We identified a clear trend involving a predominance of qualitative studies aimed at examining policies implemented and carried out with teacher participation. Furthermore, the educational policies examined originate in the fields of health and curriculum and have diversified into the fields of school management, national and supranational policies, and equity. We conclude this incipient field is an object of study in which emerging disaggregated studies do not reveal the best policies to implement in rural schools in order to differentiate their identities from those of urban schools.

Monolayers of 1,2-dipalmitoyl-sn-glycero-3-cytidine were incubated with guanine in a 0.1 M NaF electrolyte at the surface of a Langmuir trough and transferred to gold (111) electrodes using the Lan...

El presente trabajo describe el proceso de diseño y validación de un cuestionario que mide y analiza el nivel de preferencia y utilidad que atribuyen los estudiantes universitarios que cursan asignaturas mediante el desarrollo de propuestas alternativas innovadoras a través de Trabajo por Proyectos e Investigación (PTI), basados en una dinámica de aula invertida, activa y cooperativa, una evaluación formativa que tiene en cuenta tanto el proceso como el resultado utilizando rúbricas que asignan valoración en distintos niveles de logro, materiales diversos y plurales o el seguimiento progresivo de las producciones mediante carpetas de aprendizaje, entre otros. A través de un diseño metodológico de tipo encuesta (descriptivo y transversal), el instrumento se articula en 46 ítems que se agrupan en cinco categorías de doble respuesta –preferencia estudiante y preferencia profesorado-, analizadas a partir de la aplicación a 640 estudiantes universitarios. Los resultados obtenidos ofrecen cualidades psicométricas satisfactorias del instrumento que permiten considerar su utilización para medir la preferencia y utilidad de los factores asociados a los procesos de cambio mediante innovaciones en la enseñanza universitaria, señalando la coherencia en los dos niveles de preferencia y se define la tendencia de la respuesta. Las conclusiones aportan referencias fiables sobre la propuesta de innovación docente, mostrando la eficacia y utilidad para el aprendizaje que el alumnado asigna a distintos aspectos desarrollados durante el proyecto respecto a estrategias utilizadas, material o recursos, tipo de apoyos, evaluación y rendimientos. En este sentido, sirven para corregir determinadas propuestas educativas y mejorar modelos para seguir avanzando en planteamientos alternativos. De ahí, que esta investigación ayude a entender y transformar las prácticas transformadoras en la universidad. This work describes the design and validation process of a questionnaire that gauges and analyses the degree of preference and usefulness of developing innovative alternative proposals expressed by university students taking courses through Project and Research Work (PTI); a dynamic based on the active and cooperative flipped classroom; a formative evaluation that takes into account both the process and the result using rubrics that assign valuation on different levels of achievement; diversity and plural materials or the progressive monitoring of the productions through learning folders, among others. Through a methodological design of the survey type (descriptive and transversal), the instrument is articulated around 46 items grouped into five dual response categories -student preference and teacher preference- analysed following application with 640 university students. The outcomes obtained offer satisfactory psychometric qualities of the instrument that allow us to consider its use to measure the preference and usefulness of factors associated with the processes of change through innovations in university education, also, the dates indicate consistency at the two preference levels and the response trend is defined. The conclusions provide reliable references on the proposal of teaching innovation and show the effectiveness and usefulness for learning that students assign to different aspects developed during the project regarding: strategies used, material or resources, type of support, evaluation and performance. The data serve to correct certain educational proposals and improve models to continue advancing in alternative approaches. This research helps to understand and transform transformative practices in the university.

En todos los países hay escuelas rurales, con peculiaridades que las hacen únicas, a la par que comparten aspectos sustantivos. Presentamos un estudio bibliométrico en el que se analizan 32 estudios sobre escuela rural en el periodo 2015-2019 tomados de la Web of Science y Scopus. Se han filtrado en base a unos parámetros y se han analizado conforme a estos indicadores: impacto, temática, territorio, objetivo, tipo de estudio, técnicas de investigación, sujetos, tipo de escuela, resultados, conclusiones y limitaciones. Los resultados muestran que predominan los estudios locales, cualitativos, centrados en asuntos curriculares y desarrollados con maestros. Es necesario contar con estudios publicados en primeros cuartiles, emplear más de una técnica de recogida de información, mencionar las características de las escuelas rurales, apostar por muestras amplias y evitar estudios accesorios, There are rural schools in all countries, with peculiarities that make them unique, while sharing substantive aspects. We present a bibliometric study in which 32 studies on rural school in the period 2015-2019 taken from the Web of Science and Scopus are analyzed. They have been filtered based on some parameters and analyzed according to these indicators: impact, subject matter, territory, objective, type of study, research techniques, subjects, type of school, results, conclusions and limitations. The results show that local, qualitative studies predominate, focused on curricular issues and developed with teachers. It is necessary to have studies published in the first quartiles, to use more than one data collection technique, to mention the characteristics of rural schools, to bet on large samples and to avoid accessory studies, Em todos os países existem escolas rurais, com peculiaridades que as tornam únicas, ao mesmo tempo em que compartilham aspectos substantivos. Apresentamos um estudo bibliométrico no qual são analisados 32 estudos sobre escolas rurais no período 2015-2019, extraídos da Web of Science e Scopus. Eles foram filtrados com base em alguns parâmetros e analisados de acordo com estes indicadores: impacto, assunto, território, objetivo, tipo de estudo, técnicas de pesquisa, assuntos, tipo de escola, resultados, conclusões e limitações. Os resultados mostram que predominam os estudos locais, qualitativos, focados em questões curriculares e desenvolvidos com professores. É necessário ter estudos publicados nos primeiros quartis, utilizar mais de uma técnica de coleta de dados, mencionar as características das escolas rurais, apostar em grandes amostras e evitar estudos acessórios

Las escuelas rurales adoptan formatos distintos en cada país y desarrollan prácticas docentes comunes y divergentes con las urbanas. En España tenemos centros de diferentes tipos, que constituyen una compleja realidad. Sin embargo, apenas contamos con estudios comparativos entre regiones que muestren las peculiaridades de los diferentes tipos de centros y sus prácticas en nuestro país. En este artículo analizamos las semejanzas y diferencias que existen entre las dinámicas de enseñanza de las escuelas rurales del norte (Cantabria) y del sur de España (Huelva) a partir de un estudio cuantitativo (cuestionario) y cualitativo (entrevistas en profundidad). Los resultados comparan cuatro variables (práctica docente, desarrollo del curriculum, material didáctico y atención a la diversidad) en tres tipos de centros (unitarias, multigrado y graduadas). Las conclusiones muestran contrastes respecto a la innovación, el tratamiento de la diversidad o las plantillas docentes, y similitudes, en aspectos curriculares como el uso mayoritario del libro de texto o las dinámicas de enseñanza entre los diferentes tipos de centros educativos rurales., Rural schools take different forms in each country and develop common and divergent teaching practices in comparison to urban schools. In Spain we have different types of schools and this constitutes a complex reality. However, we hardly have comparative studies between regions that show the peculiarities of the different types of schools available. In this article, which adopts a quantitative (questionnaire) and qualitative (in-depth interviews) design, we analyse the similarities and differences that exist between the dynamics of teaching in rural schools in the north (Cantabria) and in the south of Spain (Huel va). The results compare four variables (environment, schools, teachers, students and families) in three types of schools (teaching practice, curriculum development, teaching materials and attention to diversity). The conclusions show contrasts with regard to innovation, attention to diversity or teaching staff; and similarities in curricular aspects such as the tendency to use textbooks or the dynamics of teaching within the different types of rural schools.

The aim of this study is to identify different learning styles in university students in the frame of university teaching carried out through innovative proposals for work and research projects, with inverted classroom dynamics (active and cooperative) and adopting a formative assessment that focuses on both the process and the students’ outcomes. This proposal is complemented by the objective of determining the influence of different learning styles on the preference for the type of performance in university teaching. A hypothetico-deductive methodological design for exploratory and correlational purposes was followed. The sample consisted of total of 640 participants in university degree courses. The data were gathered using a questionnaire that grouped 46 items into five double-response dimensions, determined by the preference or position held by the students regarding the learning strategies, methods and techniques applied; material or resources used to carry out the teaching, as well as the integration of information and communication technologies (ICT); type of supports that were received in the process; instruments to carry out the assessment; and lastly, individual or team academic performance. The outcomes show an x-ray of four models according to the student's learning styles: individual, cooperative, dependent and autonomous. These are identified with four clusters in the sample of students selected for the study, which are associated with practical, conventional, critical and efficient student models. The conclusions explain that there are no pure models, as there are nuances that connect them in real classroom practice, but the level of student preference helps to measure the impact and confirms the improvement in teaching through university work projects.

The cationic lipid didodecyldimethylammonium bromide (DDAB) is one of the agent that is included in formulations for liposomes with anchored gold nanoparticles as drugs carriers because its positive charge facilitates the anchoring of the negatively charged stabilized gold nanoparticles to the lipid components of the liposomes. In this paper a thermodynamic analysis of Langmuir isotherms was performed, as a first step in the preparation of liposomes including DDAB, the phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and cholesterol(Ch),to decide about the most stable combination. Monolayers of DMPC:Ch:DDAB with the most energetically favourable composition, were transferred to Au(111) electrodes by the Langmuir-Schaefer technique in the electrochemical cell and characterized by impedance spectroscopy. The results were compared with those obtained with electrodes coated with DMPC:Ch films that did not contain DDAB. In both cases the frequency dispersion of impedance data indicates high homogeneity of the films in a wide potential range around the capacitance minimum. The inclusion of the anticancer drug doxorubicin (DOX) into the mixed lipid monolayers and its electrochemical reduction at pH 4.5 were studied by voltammetry and by impedance spectroscopy. At potentials out of the faradaic region the inclusion of DOX does not affect significantly the frequency dispersion of the impedance but decreases the capacitance. However, at negative potentials the analysis of the high frequency dispersion of the impedance and the influence of the scan rate on the voltammograms indicate a reduction process with contribution of adsorption and diffusion of DOX. Diffusion was avoided by transferring the electrodes coated in the Langmuir trough to the electrochemical cells that do not contain the drug. Under these conditions the reduction of the adsorbed DOX was found to obey the model of a surface confined electrode and the charge transfer resistance, Ra, and adsorption capacitance, Ca, were obtained at potentials of the faradaic region. The combination of both parameters provides the rate constant for the reduction in a wide potential range that allows us to propose a sequential mechanism with two determining steps.

The adsorption of the three adenine forms involved in two acid-base equilibria on Au(111) electrodes is studied by Electrochemical Impedance Spectroscopy. The experiments are performed in solutions of pH values 1, 7.5 and 12, at which the cationic, the neutral and the anionic adenine forms are present, respectively. Two adsorption models are adopted, both based on the theory of Frumkin and Melik-Gaykazyan for the adsorption process, but one of them takes also into account a deprotonation step preceding the adsorption step. The same frequency dependence of the impedance data is observed in the three pH media. The Nyquist admittance plots suggest a mixed kinetic control, by adsorption and by diffusion. The analysis of the electrode impedance or admittance as a function of the frequency according to the adsorption models provides the values of adsorption resistance, Rad, adsorption Warburg coefficient, σad and adsorption capacitance, Cad as a function of potential. From the σadvs E plot obtained at pH 1 an equilibrium constant for adenine deprotonation at the vicinity of the electrode surface of c.a. 0.03 is calculated, which is three orders of magnitude higher than the equilibrium constant in the bulk solution. The different potential dependency of the adsorption rates at the three pH values is discussed on the basis of a Frumkin isotherm for the adsorption of adenine and a Butler-Volmer type potential dependence for the adsorption rate constant.

La incorporación a la educación superior de herramientas como plataformas virtuales o redes sociales supone una nueva reformulación del proceso de enseñanza-aprendizaje. Esta investigación analiza la utilidad didáctico-pedagógica de la plataforma educativa Moodle y de la red social Facebook para identificar sus potencialidades y controversias. Se presenta un estudio descriptivo e interpretativo que combina el diseño cualitativo y cuantitativo, para conocer la opinión del profesorado y alumnado de las titulaciones de grado de la Facultad de Ciencias de la Educación de la Universidad de Huelva (España). Los resultados profundizan en la importancia de la formación previa, la valoración positiva de su utilización como material didáctico, la potenciación de la colaboración o el debate en cuanto a su accesibilidad y uso. En conclusión, la información recabada apunta la pertinencia del uso de estas herramientas en el aprendizaje del alumnado y la necesidad de un cambio en las estructuras y la formación docente para mejorar la calidad de la enseñanza. Introduction of tools as virtual platforms or social network to the university means a new construction of learning-teaching process. This research analyzes the educational and didactic utility of Moodle platform and Facebook to identify its potentialities and controversies. It is presented a descriptive and interpretative study which combines qualitative and quantitative design, in order to know the opinion of the professors and students in degrees in the Faculty of Educational Sciences of the University of Huelva (Spain). The results stress the importance of the previous training, the positive assessment of its didactic use, the increase of the collaboration due to its accessibility. In conclusion, the information we collected shows the relevance of using these tools in student learning and as the need for a change in both as much educational structures and teaching training in order to improve the quality of the teaching.

El presente artículo expone el currículum integrado como un referente bien asentado en la tradición innovadora desde los inicios del siglo XX, alternativa que -aunque minoritaria frente al modelo convencional disciplinar- se puede encontrar en múltiples tentativas de cambio, reforma e innovación de momentos muy diversos de nuestra reciente historia educativa. Su presencia en las denominadas “pedagogías emergentes” corrobora su dinamismo y actualidad. El nivel de relación que se establezca entre las materias, así como el amplio abanico de estrategias descrito en este trabajo, expresan como los distintos asuntos, conocimientos y propósitos pueden acomodarse en un modelo curricular que se define por su flexibilidad, intención funcional y participación. Con un sentido ilustrativo, se describen y explican diferentes modelos y secuencias prácticas pero que en esencia comparten un bagaje pedagógico que les caracteriza y diferencia de otras propuestas más preocupadas por la transmisión mecánica y academicista del conocimiento escolar. This article presents the integrated curriculum as a reference point implemented in the innovative tradition since the beginning of the 20th century, an alternative that -although a minority compared to the conventional disciplinary model- can be found in multiple attempts at educational change, reform and innovation at very different times in our recent educational history. Its presence in the so-called "emerging pedagogies" corroborates its dynamism and actuality. The level of relation established between subjects as well as the wide range of strategies described in this work express how different subjects, knowledge, and purposes can be accommodated in a curricular model that is defined by its flexibility, functional intention, and participation. In an illustrative sense, different models and practical sequences are described and explained, but which in essence share a pedagogical background that characterizes them and differentiates them from other proposals more concerned with the mechanical and academic transmission of school knowledge. Cet article présente le curriculum intégré comme une référence bien établie dans l'innovation depuis le début de la s. XX. Sa présence dans les «pédagogies émergentes» d'aujourd'hui corrobore son dynamisme et son actualité. Le niveau de relation établi entre les matières ainsi que les stratégies décrites tout au long de ce travail expriment comment les différentes connaissances et finalités peuvent être intégrées dans un modèle curriculaire qui se définit par sa flexibilité, son intention fonctionnelle et sa participation. À titre d'illustration, différents modèles et séquences pratiques sont décrits et expliqués, mais ils partagent une base pédagogique qui les différencie des autres tentatives plus concernées par la transmission académique des connaissances scolaires. FEDER Andalucía 2014-2020 UHU1256182

RESUMEN: Las escuelas rurales en España constituyen una realidad tan amplia y multiforme como invisible y compleja, sin embargo, no contamos con estudios comparativos entre regiones que muestren las diferentes realidades que existen bajo el término "escuela rural" en nuestro país. Por ello, en este artículo nos preguntamos por las semejanzas y diferencias que existen entre las escuelas rurales del norte y del sur de España. En este sentido, se desarrolla un estudio cuantitativo y cualitativo en el que se explora la situación de las escuelas rurales mediante un cuestionario y entrevistas en profundidad en tres tipos de centros (aulas unitarias, centros rurales agrupados y centros graduados ubicados en el medio rural) en dos provincias muy rurales tradicionalmente: Cantabria y Huelva. Se observan contrastes en el entorno y el profesorado, y similitudes en los centros, el alumnado y las familias. Las escuelas están menos aisladas y cuentan con un profesorado más estable en el norte. El profesorado se muestra optimista y cuenta con un alumnado bien dispuesto. La participación de las familias es mejorable, pero tienen altas expectativas en la escuela. El reto es y sigue siendo asegurar un sistema educativo equitativo que ayude a mantener vivo el mundo rural. ABSTRACT: Rural schools in Spain constitute a reality as wide and multiform as invisible and complex; however, we do not have comparative studies between regions that show the different realities that exist under the term "rural school" in our country. Therefore, in this paper we ask ourselves the similarities and differences that exist between the rural schools of the north and the south of Spain. In this sense, a quantitative and qualitative study is developed in which the situation of rural schools is explored by means of a questionnaire and in-depth interviews in three types of centres (unitary classrooms, grouped rural centres and graduate centres located in the rural environment) in two traditionally very rural provinces: Cantabria and Huelva. Contrasts are observed in the setting and the teaching staff and similarities in the centres, the students and the families. The schools are less isolated and have a more stable teaching staff in the north. The teachers are optimistic and have a well-disposed student body. The participation of families can be improved, but they have high expectations of the school. The challenge is and remains to ensure an equitable education system that helps keep the rural world alive.

La complejidad de los numerosos centros educativos situados en el medio rural exige estudios específicos. Dado que todas las investigaciones señalan el papel relevante de las direcciones escolares, en este artículo se pretende conocer la situación de las escuelas rurales españolas a partir de la realización de entrevistas a directores escolares de dos comunidades autónomas con el objetivo de conocer sus posibilidades, limitaciones y demandas en la actualidad. Los resultados muestran semejanzas y diferencias singulares entre las escuelas unitarias, los colegios rurales agrupados y los centros de educación infantil y primaria. Las conclusiones revelan una escuela rural que tiene posibilidades como la individualización de la enseñanza debido a las ratios bajas; limitaciones como la interinidad del profesorado, contextos aislados o desfavorecidos y bajo nivel cultural o expectativas educativas; y demandas de servicios e infraestructuras, de dotación en tecnologías de la información, y de oferta cultural en las proximidades del centro., The complexity of numerous education centers located in rural areas demands specific studies. Given that all investigations remark on the relevant role of school management, this article proposes to examine the situation of Spanish rural schools, by conducting interviews with school managers in two autonomous communities with the aim of identifying their possibilities, limitations, and demands in the present day. The results show singular similarities and differences between unitary schools, grouped rural schools, and pre-school and elementary education centers. The conclusions reveal a rural school which has possibilities like individualization of teaching due to low ratios; limitations like temporary status of teachers, isolated or underprivileged contexts, and low cultural level or educational expectations; and demand for services and infrastructure, access to information technology, and cultural offerings in proximity to schools.

The adsorption of thymine on gold electrodes has been studied by ATR-SEIRAS in situ spectroscopy at three pH values (1, 7 and 12), in order to analyse the tautomeric equilibrium of deprotonated thymine in the adsorbed state. The anionic form which is deprotonated in nitrogen N1 (N1 tautomer) and the one deprotonated in nitrogen N3 (N3 tautomer) are considered. The spectroscopic results have been interpreted in the light of DFT ab-initio calculations of both tautomeric forms adsorbed on gold surfaces. The basis sets 6-311 + +G(d,p) for C, H, O and N atoms and LANDL2DZ for Au atoms have been used. The electrode surface has been simulated as an unreconstructed Au(111) surface of 19 atoms. The preponderance of each tautomer of adsorbed thymine as a function of pH has been inferred from the analysis of the spectral signals in the 1500–1800 cm−1 wavenumber region related mostly to stretching modes of the carbonyl groups. It has been found that the adsorbed N3 tautomer predominates in the case of adsorption from acid media while the N1 tautomer predominates in the adsorption from basic media but the adsorption of both forms have been distinguished in the experiments from neutral media. Moreover, the plausible changes in the orientation of the two adsorbed tautomers with the electric field have been determined by analysing the relative intensities of the characteristic CH stretching signals in the 2800–3300 cm−1 spectral region. It is proposed that the N3 tautomer undergoes changes in the interaction sites with the metal and in the molecular plane orientation on the electrode as the electric potential is increased, but the N1 tautomer molecule keeps the interaction sites while the molecular plane slightly rotates to facilitate the electrostatic interaction with the field. Financial support from the Spanish Ministry of Economy and Competitiveness (CTQ2014-57515-C2-1-R and CTQ-2013-44083-P) and from the Junta de Andalucia (PAI FQM202) is gratefully acknowledged.

The effect of the electrode potential on the orientation and conformation of the 1,2-dipalmitoyl- sn-glycero-3-cytidine monolayer deposited on a gold (111) electrode surface was described. The potential of zero free charge ( Epzc) for the monolayer-covered electrode was determined to be -0.2 V vs SCE. The differential capacitance and charge density data indicated that the monolayer is stable at the electrode surface when ( E - Epzc) > 0.0 V. At negative rational potentials, a progressive detachment (electrodewetting) of the monolayer occurs. The monolayer is fully detached from the electrode surface at ( E - Epzc) 0.0 V, the plane of the cytosine moiety assumes a small angle of ∼20° with respect to the surface. At negative potentials, the tilt angle of the cytosine fragment increases and rotates. With the help of DFT calculations, these changes were explained by the repulsion of the positive pole of the cytosine permanent dipole moment by the positively charged gold surface and its attraction to the metal surface at negative electrode potentials. This work provides unique information for the future development of sensors based on the molecular recognition of nucleoside targets.

A hybrid bilayer lipid membrane (hBLM), constructed with a 1-hexadecanethiol self-assembled interior leaflet and a 1,2-dipalmitoyl-sn-glycero-3-cytidine nucleolipid exterior leaflet, was deposited at the surface of a gold (111) electrode. This system was used to investigate the molecular recognition reaction between the cytosine moieties of the lipid head group with guanine molecules in the bulk electrolyte solution. Electrochemical measurements and photon polarization modulation infrared reflection absorption spectroscopy (PMIRRAS) were employed to characterize the system and determine the extent of the molecular recognition reaction. The capacitance of the hBLM-covered gold electrode was very low (~1 μF cm−2), therefore the charge density at the gold surface was small. Changing the electrode potential had a minimal effect on the complexation between the cytosine moieties and guanine molecules due to small changes in the static electric field across the membrane. This behavior favored the formation of the guanine–cytosine complex.

En los últimos tiempos se ha experimentado un mayor uso de redes sociales en asignaturas del contexto universitario. Se presenta un estudio que sistematiza las concepciones del alumnado y profesorado sobre Facebook, en lo referente a su utilidad en la práctica y en el desarrollo de las asignaturas que posibilitan y fomentan su manejo dentro y fuera del aula, como algo más que una vía de contacto directo con el docente. Se llevará a cabo un diseño metodológico que combina instrumentos cuantitativos y cualitativos, utilizando de esta forma una metodología mixta. Se pretende analizar la pertenencia pedagógica del manejo de Facebook, cuestionando sí es una herramienta de soporte o, por el contrario, conlleva a la interacción didáctica potenciando los aprendizajes. Los resultados y conclusiones apuntan el uso de las redes sociales como recurso didáctico que promueve y facilita el intercambio colaborativo entre estudiantes y docentes. In recent times, there has been increased use of social networks in the university context. In this sense, we present a study that systematizes the conceptions that students and teachers have regarding the use of Facebook in practice and the development of courses that enable and encourage its handling inside and outside the classroom, as more than just a way of direct contact with the teacher. The methodological design combines qualitative and quantitative instruments, using a mixed methodology. We analyzed the pedagogical relevance of the use of Facebook, questioning if this social network is used as a supportive or conversely didactic interaction leads to enhancing learning. The findings and conclusions point to a conception of social networks as a teaching resource that promotes collaborative exchange between students and teachers.

PURPOSE Interventions tailored to sociopsychological factors associated with health behaviors have promise for reducing colorectal cancer screening dispari- ties, but limited research has assessed their impact in multiethnic populations. We examined whether an interactive multimedia computer program (IMCP) tai- lored to expanded health belief model sociopsychological factors could promote colorectal cancer screening in a multiethnic sample. METHODS We undertook a randomized controlled trial, comparing an IMCP tailored to colorectal cancer screening self-efficacy, knowledge, barriers, readi - ness, test preference, and experiences with a nontailored informational program, both delivered before office visits. The primary outcome was record-documented colorectal cancer screening during a 12-month follow-up period. Secondary outcomes included postvisit sociopsychological factor status and discussion, as well as clinician recommendation of screening during office visits. We enrolled 1,164 patients stratified by ethnicity and language (49.3% non-Hispanic, 27.2% Hispanic/English, 23.4% Hispanic/Spanish) from 26 offices around 5 centers (Sac - ramento, California; Rochester and the Bronx, New York; Denver, Colorado; and San Antonio, Texas). RESULTS Adjusting for ethnicity/language, study center, and the previsit value of the dependent variable, compared with control patients, the IMCP led to sig- nificantly greater colorectal cancer screening knowledge, self-efficacy, readiness, test preference specificity, discussion, and recommendation. During the follow- up period, 132 (23%) IMCP and 123 (22%) control patients received screening (adjusted difference = 0.5 percentage points, 95% CI -4.3 to 5.3). IMCP effects did not differ significantly by ethnicity/language. CONCLUSIONS Sociopsychological factor tailoring was no more effective than nontailored information in encouraging colorectal cancer screening in a multi- ethnic sample, despite enhancing sociopsychological factors and visit behaviors associated with screening. The utility of sociopsychological tailoring in address- ing screening disparities remains uncertain.

The structural facilities provided by the ‘in situ’ Surface-Enhanced Infrared Absorption Spectroscopy in the Attenuated Total Reflection mode (ATR-SEIRAS) are exploited for the characterization of cytosine adsorption on gold thin-film electrodes from acid, neutral and basic solutions, using H2O and D2O as solvents. The experimental conditions are selected in order to consider the two forms involved in the first acid-base equilibrium and in the tautomeric keto-enol and amino-imino equilibria of the molecule. The results are compared with the corresponding absorption FT-IR spectra of cytosine in solution. DFT calculations are used to optimize the molecular geometries and to estimate the vibrational properties of the different acid-base and tautomeric forms, either in solution or in the adsorbed state on gold surfaces. The comparison between the spectra in solution and in the adsorbed state indicates the adsorption of the deprotonated form even at pH bellow the first pKa of cytosine. Therefore, only the tautomeric forms of the deprotonated cytosine are considered: the keto-amino (C1 and C4), the enol-amino (C2) and the keto-imino (C3) tautomers of cytosine and of deuterated cytosine molecules. Interpretations of the absorption FT-IR spectra of the molecules in solution based on DFT calculations suggest the preponderance of the C1 tautomer in solution but with contributions of the C3 tautomer, in neutral and basic media. However, the interpretations of the ATR-SEIRAS experiments show the preponderance of tautomer C3 in the adsorbed state with contributions of tautomer C1 depending not only on the pH of the solution, but also on the potential applied to the electrode.

The co-adsorption of complementary DNA bases adenine and thymine on gold thin-film electrodes from 0.1 M HClO4 solutions in H2O and D2O is studied by surface-enhanced infrared absorption spectroscopy in the attenuated total reflection mode (ATR-SEIRAS). The comparison of the spectra in the range 1750–1550 cm− 1 for co-adsorbed adenine and thymine at controlled potentials to those of the individual adsorbed bases shows the enhancement of the signals associated to the vibration modes of adenine and the inhibition of those of thymine. The results can be explained by invoking the rearrangement of both molecules on the electrode surface in order to facilitate the Watson–Crick (W–C) and/or Hoogsteen (HG) interactions between the bases. The co-adsorption seems to be a cooperative process in which a low surface concentration of each base can induce the rearrangement of the complementary base molecules on the surface. Financial support from Ministerio de Educación y Ciencia (Spain) (Projects CTQ2010-19823 and CTQ2009-13142 and a FPU-grant to JA), Junta de Andalucía (Grupo FQM202) and Generalitat Valenciana (ACOMP/2011/200) are greatly acknowledged.

Resumen: La educación rural se define por su diversidad e invisibilidad. Todo intento de homogeneizar la escuela rural está dirigido a responder con estereotipos que en poco se corresponden con el análisis concreto de cada situación, siempre distante de la etiqueta general pretendida. En este artículo situamos la relevancia socioeducativa que está adquiriendo la educación rural y exponemos las diferentes formas que adopta; nos preguntamos por el papel que tienen en la actualidad los libros de texto en este tipo de escuelas, dado que es un recurso ampliamente empleado y característico de un modelo escolar urbano. Diseñamos un estudio cuantitativo que hemos aplicado en escuelas del sur de España, donde indagamos sobre la utilización de este recurso curricular. Los resultados permiten conocer el manejo que se hace de los libros de texto en la actualidad: grado de uso, editoriales habituales, visión de estos, entre otros aspectos. Concluimos que las escuelas rurales emplean este recurso debilitando su esencia; por ello, finalizamos con una propuesta de mejora que supone un reto para la escuela rural actual: reducir el uso del libro de texto y desarrollar cada vez más proyectos de trabajo. Abstract: Rural education is defined by its diversity and invisibility. Any attempt to homogenize the rural school is bound to respond on the basis of stereotypes, which in short correspond with the concrete analysis of each situation, always distant from the intended general etiquette. In this article we situate the relevance that rural education is acquiring and we expose the different forms that it adopts, asking for the role of textbooks in these types of schools today, given that it is a resource widely used and characteristic of an urban school model. To answer this question we have designed a quantitative study investigating the use of this resource that we have applied in schools in southern Spain. The results allow us to know the use that is made of textbooks today: degree of use, regular editorials, vision of the same, etc. It is possible to conclude that rural schools use this resource weakening its essence, so we end up with a proposal for improvement that poses a challenge for the current rural school: reduce the use of textbooks and develop more and more work projects.

Esta investigación tiene como objetivo profundizar en la realidad del planteamiento de la atención a la diversidad en la etapa de educación primaria. A través de un enfoque cualitativo, se analizan las concepciones y prácticas que desarrolla el profesorado de pedagogía terapéutica (PT) en sus aulas; los avances y limitaciones que experimenta; el tipo de formación continua de la que disponen, entre otras. Los resultados muestran el grado de inclusión de sus acciones a la vez que indican la necesidad de fomentar la implicación entre docentes y mejorar la formación de los especialistas. Las conclusiones indican la satisfacción del PT con su práctica educativa y la necesidad de una formación continua que ayude a buscar el desarrollo normalizado del estudiante y la superación de las barreras existentes. The objective of this research is to deepen in the reality of the diversity attention in primary education stage. From a qualitative approach, the conceptions and practices developed by therapeutic pedagogy (PT) teachers in their classrooms are analyzed. Besides, the advances and limitations that they experience and the type of their continuous training, among others, are also considered. The results show the degree of inclusion of their actions, while indicating the need to foster involvement among teachers and improve the training of specialists. The conclusions indicate the PT's satisfaction with its educational practice and the need for continuous training that helps to seek the student's standard development and overcoming existing barriers.

La incorporación a la educación superior de herramientas como plataformas virtuales o redes sociales supone una nueva reformulación del proceso de enseñanza-aprendizaje. Esta investigación analiza la utilidad didáctico-pedagógica de la plataforma educativa Moodle y de la red social Facebook para identificar sus potencialidades y controversias. Se presenta un estudio descriptivo e interpretativo que combina el diseño cualitativo y cuantitativo, para conocer la opinión del profesorado y alumnado de las titulaciones de grado de la Facultad de Ciencias de la Educación de la Universidad de Huelva (España). Los resultados profundizan en la importancia de la formación previa, la valoración positiva de su utilización como material didáctico, la potenciación de la colaboración o el debate en cuanto a su accesibilidad y uso. En conclusión, la información recabada apunta la pertinencia del uso de estas herramientas en el aprendizaje del alumnado y la necesidad de un cambio en las estructuras y la formación docente para mejorar la calidad de la enseñanza., Introduction of tools as virtual platforms or social network to the university means a new construction of learning-teaching process. This research analyzes the educational and didactic utility of Moodle platform and Facebook to identify its potentialities and controversies. It is presented a descriptive and interpretative study which combines qualitative and quantitative design, in order to know the opinion of the professors and students in degrees in the Faculty of Educational Sciences of the University of Huelva (Spain). The results stress the importance of the previous training, the positive assessment of its didactic use, the increase of the collaboration due to its accessibility. In conclusion, the information we collected shows the relevance of using these tools in student learning and as the need for a change in both as much educational structures and teaching training in order to improve the quality of the teaching.

“Two-dimensional voltammetry” using arrays of variable-sized gold channel microband electrodes in combination with variable flow rate measurements together with independent gold rotating disk electrode (RDE) data is applied to characterize the oxidation mechanism of l-ascorbic acid (AH2) to dehydro-l-ascorbic acid in aqueous solutions. At pH 2.1 and very low mass transport conditions the reaction is consistent with a CECE mechanism, while at higher mass transport conditions an ECfastCE mechanism is followed. At pH 6.7, the results are again consistent with an ECE mechanism. The following mechanism is proposed: AH2 ⇌ AH- + H+ (kCEE), AH- → AH• + e, AH• → A• - + H+ (kECE), A• - → A + e (CECE); AH2 ⇌ AH2+ + e, AH2+ → AH• + H+(fast), AH• → A• - + H+ (kECE), A• - → A + e (ECfastCE); where, only the first pathway applies at pH 6.7, AH- being the starting species. Values of 3.4 × 103 s-1 and 500 s-1 are found for the rate constants kCEE and kECE, respectively.

The reduction of nitromethane in aqueous solution (pH 8.3) at Au/Hg channel electrodes is suggested, by means of joint electrochemical ESR and voltammetric measurements, to follow an ECEEE mechanism in which the rate determining chemical step is a surface catalysed reaction. Theory characterising heterogeneous ECE (and ECEEE) processes at channel electrodes, studied voltammetrically and with in situ ESR detection, is reported. © 1997 Elsevier Science S.A.

Theory is developed for heterogeneous ECE reactions occurring at channel electrode that predicts the voltammetric waveshape, as characterized by the half-wave potential and the Tafel slope as a function of the rate of mass transport and the cell geometry. Working surfaces are reported that allow the ready mechanistic interpretation of experimental data and the deduction of corresponding rate constants. Experiments are reported on the reduction of nitromethane in aqueous buffered solution (7 < PH < 9) at platinum electrodes that is thought to proceed via a heterogeneous ECEEE mechanism. Analysis of both waveshape and limiting current data confirm this mechanistic assignment, allowing the following appropriate kinetic parameters to be reported: heterogeneous rate constant. 0.26 ± 0.07 cm s-1; and standard electrochemical rate constant, 0.13 ± 0.01 cm s-1.

A channel electrode array, with electrodes ranging in size from the millimeter to the submicrometer scale, is used for the amperometric interrogation of mechanistically complex electrode processes. In this way, the transport-limited current, measured as a function of both electrode size and electrolyte flow rate (convection), is shown to provide a highly sensitive probe of mechanism and kinetics. The application of "two-dimensional voltammetry" to diverse electrode processes, including E, ECE, ECEE, EC', and DISP2 reactions, is reported.

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.langmuir.6b00635 Quantitative subtractively normalized interfacial Fourier transform infrared reflection spectroscopy (SNIFTIRS) was used to determine the molecular orientation and identify the metal–molecular interactions responsible for the adsorption of adenine from the bulk electrolyte solution onto the surface of the Au(111) electrode. The recorded p-polarized IR spectra of the adsorbed species were subtracted from the collected s-polarized IR spectra to remove the IR contributions of the vibrational bands of the desorbed molecules that are located within the thin layer cavity of the spectroelectrochemical cell. The intense IR band around 1640 cm–1, which is assigned to the pyrimidine ring stretching vibrations of the C5–C6 and C6–N10 bonds, and the IR band at 1380 cm–1, which results from a combination of the ring stretching vibration of the C5–C7 bond and the in-plane CH bending vibration, were selected for the quantitative analysis measurements. The transition dipoles of these bands were evaluated by DFT calculations. Their orientations differed by 85 ± 5°. The tilt angles of adsorbed adenine molecules were calculated from the intensity of these two vibrations at different potentials. The results indicate that the molecular plane is tilted at an angle of 40° with respect to the surface normal of the electrode and rotates by 16° around its normal axis with increasing electrode potential. This orientation results from the chemical interaction between the N10 and gold atoms coupled with the π–π parallel stacking interactions between the adjacent adsorbed molecules. Furthermore, the changes in the molecular plane rotation with the electric field suggests that the N1 atom of adenine must also participate in the interaction between the molecule and metal. Spanish Ministry of Science and Technology (CTQ2010- 19823), Spanish Ministry of Economy and Competitiveness (CTQ2014-57515-C2-1-R), Junta de Andalucia (PAI FQM202) and Discovery Grant from Natural Sciences and Engineering Council of Canada

In situ external reflection infrared reflection spectroscopy (IRRAS) and surface-enhanced infrared reflection absorption spectroscopy under attenuated total reflection conditions (ATR-SEIRAS) have been used to study the adsorption of adenine at Au(1 1 1) and gold thin-film electrodes in 0.1 M HClO 4 solutions in deuterium oxide and in water. The existence of protonated and deprotonated adenine molecules at the electrode surface has been proved from the comparison of the spectra for adsorbed adenine with those obtained for dissolved adenine. In all cases, characteristic band frequencies are observed for the enhanced ring stretching band in D 2 O and also the bending band of the amino group in H 2 O. Both signals appear at higher wavenumbers for the protonated species. In acid media, deprotonation of adsorbed adenine is induced by increasing positive potentials and/or adenine coverage leading to the same adsorbed species as previously reported in basic media, namely chemically adsorbed adenine with a tilted orientation of the molecular plane on the electrode. Co-adsorption of water and perchlorate anions is detected in the case of the acid media, indicating the involvement of these species in the stabilization of the organic film. Time-resolved experiments at negative potentials and low adenine concentrations have shown also the physical adsorption of protonated adenine and have allowed the monitoring of the adsorption of the protonated and unprotonated forms as a function of time. Adsorption of unprotonated adenine is slower but is favored at the equilibrium at the electrode surface even if the pH of the media is three units lower than the p K a of adenine in solution.

The kinetics of azobenzene reduction on mercury electrodes in the absence of diffussional mass transport is studied by electrochemical impedance spectroscopy (EIS) in acetic acid/acetate buffered solutions at different pH values. Cyclic voltammetry experiments confirm the absence of diffusion effects and provide the values of the surface equilibrium potential. The analysis of the impedance frequency spectrums at every potential within the faradaic region conforms well the model and provides the global rate constant of the process, kf. The potential dependence of kf suggests the existence of an EE mechanism, with two electron transfers controlling the overall rate. The kinetic parameters of every step are obtained and their pH dependences clarify the role played by the protonation steps.

The adsorption/desorption kinetics of adenine on Au(1 1 1) electrodes is studied by Electrochemical Impedance Spectroscopy (EIS) in 0.5 M NaF solutions at four adenine concentrations. The experimental procedure is designed in order to obtain impedance data unaffected by surface reconstruction on the entire potential region of adsorption. The frequency dispersion of the impedance at potentials of the adsorption region has been analysed according to the Frumkin–Melik–Gaykazyan adsorption theory without any “a priori” assumption about the potential dependence of the adsorption rate constant. The analysis provides the values of the adsorption capacitance, C ad , adsorption resistance, R ad and the Warburg coefficient, σ ad , at every potential, and from them the relaxations times τ H and τ D. A mixed adsorption–diffusion control has been detected and the specific rate constant of adsorption has been obtained in a wide potential region.

Adenine adsorption at gold electrodes is studied in neutral sodium fluoride solutions by cyclic voltammetry and in situ infrared spectroscopy. External reflection measurements were performed with Au(111) and Au(100) single crystal electrodes in D 2 O solutions, whereas surface enhanced infrared reflection absorption spectroscopy experiments under attenuated total reflection conditions were carried out with sputtered gold thin-film electrodes, both in D 2 O and H 2 O solutions. The results clearly show the specific adsorption of the molecule providing significant surface enhancement of the strong ring stretching band and the scissoring mode of the amino group. On the basis of the results, an adsorption model is proposed in which the molecular plane and the C-N(H 2 ) bond are tilted on the electrode surface. Coordination is proposed to take place via the N(amino) atom upon sp' hybridization and the N 7 atom of the ring. The model applies irrespective of the surface crystallographic orientation of the electrode or the applied potential. The influence of the reconstructed or the unreconstructed state of the surface is inferred from the analyses of the spectra recorded while scanning the potential in opposite directions.

El objetivo de este trabajo es conocer y contrastar la valoración del profesorado sobre los libros de texto como desarrolladores del currículum oficial y garantes de ciertas recomendaciones de la didáctica general y específica. El uso de una metodología integrada ha permitido conjugar dos líneas de investigación en un sólo estudio en busca de interpretaciones más elaboradas de una misma realidad. Mediante el análisis de contenido hemos obtenido una visión muy aproximada del tratamiento didáctico que los manuales imprimen a estas enseñanzas, al tiempo que la administración de un cuestionario a una muestra de 863 docentes nos ha permitido conocer sus concepciones respecto a nuestros temas de estudio. Las principales conclusiones giran en torno a la debilidad del material para dar respuesta a las demandas normativas y bibliográficas, la presencia de un amplio sector del profesorado que conoce las limitaciones de los textos escolares, el descontento expreso de una pequeña minoría y, sin embargo, el uso mayoritario, y en muchos casos exclusivo, de este material en las aulas. Esta paradoja nos obliga a seguir explorando las representaciones didácticas propias de los docentes, así como los caminos para alcanzar una mayor sintonía entre concepciones y prácticas., The objective of this paper is to know and contrast the assessment of teachers on textbooks as the official curriculum developers and guarantors of certain recommendations of general and specific didactics. The use of an integrated methodology has allowed combining two lines of research in a single study in pursuit of some more elaborated interpretations of the same reality. Through content analysis we have obtained a very approximate view of the didactic treatment that manuals print into these teachings, at the same time we administered a questionnaire to a sample of 863 teachers which has allowed us to know their views about our subjects of study. The main conclusions builds on the weakness of the material to respond to regulatory and bibliographical demands, the presence of a large sector of teachers who know the limitations of textbooks, the express discontent of a small minority and, however, the majority use, and in many cases exclusive, of this material in the classroom. This paradox requires further exploration on didactics representations specific to teachers as well as the ways to achieve greater harmony between conceptions and practices.

Adsorption of adenine on Au(1 1 1) and Au(1 0 0) electrodes is studied by cyclic voltammetry, impedance and chronoamperometric measurements in 0.1 M and 0.01 M KClO4 and in 0.5 M NaF solutions. The experiments performed with flame-annealed electrodes at different contact potentials, scan potential limits and scan rates, suggest different adsorption behaviour on the unreconstructed and reconstructed surface domains. This is confirmed by comparing the results obtained with electrochemically annealed unreconstructed and with flame-annealed reconstructed surfaces. In both cases the initial electrode surface state is characterised by the Epzc values. The adsorption on reconstructed surfaces takes place at more positive potentials than on the unreconstructed surfaces and induces the lifting of the reconstruction. The thermodynamic analysis is performed on the chronoamperometric data for adenine desorption on well characterised unreconstructed Au(1 1 1) surfaces. To this end a new methodology of the chronoamperometric experiments is introduced. Quantitative thermodynamic adsorption parameters such as surface tension, Gibbs surface excess, Gibbs energy of adsorption, potential versus Gibbs excess slope and electrosorption valency are determined. Weak chemisorption of adenine is inferred with a molecular orientation independent on the coverage and on the electrode potential. It is proposed that adsorbed adenine molecules adopt a tilted orientation at the surface to facilitate the coordination to the gold atoms.

A new mechanism (the C–(C)–CE mechanism) is proposed for Tl + reduction and Tl–amalgam oxidation on gramicidin-modified dioleoylphosphatidylcholine (DOPC) mercury and Tl–amalgam electrodes. The faradaic impedance equations are derived, and applied to the experimental results obtained in 0.1 M KCl solutions at a high gramicidin concentration. The mechanism includes two consecutive heterogeneous chemical steps with an intermediate, which decomposes in a parallel homogeneous chemical step. The two heterogeneous chemical steps are assumed to mimic the interaction of the ion with the channel mouth and the further translocation across the channel, respectively. The results fit the mechanism well, and the analysis provides the equilibrium constant for the first chemical step and the forward rate constant for the translocation step. The latter was found to depend on the drop in potential across the interface, with a transfer coefficient α =0.2, in both the reduction and the oxidation experiments. However, the translocation step standard rate constant provided by the oxidation experiment is lower than that by the reduction experiment, indicating some asymmetry in the half-channel behaviour.

We report the use of scanning electrochemical microscopy (SECM) to control the generation of Tl(I) at a mercury substrate and detect this species at a mercury-coated tip to study the transport of these ions through ion channels. The transport of Tl(I) across gramicidin D half-channels imbedded in a dioleoylphosphatidylcholine (DOPC) monolayer supported on a Tl amalgam hanging mercury drop electrode (HMDE) was studied using the substrate generation−tip collection mode of SECM. A Hg/Pt “submarine” electrode, used as the SECM tip, was made through simple contact of the Pt ultramicroelectrode with the HMDE. The tip transient response for the collection of generated Tl(I) at the amalgam HMDE was recorded for several tip to substrate distances. This collection−generation experiment was repeated with a DOPC-modified Tl/HMDE and a gramicidin−DOPC-modified Tl/HMDE. An apparent heterogeneous rate constant (khet = 2.8 (±0.1) × 10-4 cm/s) for the transport of Tl(I) through the gramicidin to the tip was extracted.

In situ Fourier transform infrared reflection absortion spectroscopy (FT-IRRAS) has been used in the external (SNIFTIRS method) and the internal (ATR-SEIRAS) reflection configurations to determine the pH influence, in the neutral and basic range, on the adsorption of adenine on Au(111) and gold nanofilm electrodes from D2O and H2O solutions. In D2O solutions, the main adsorbate band around 1640 cm−1,due to a ring stretching mode, shows different characteristics in the spectra collected at pH values at which the neutral and the basic adenine forms predominate in solution. The analysis of these differences, in comparison with the respective spectra of adenine in solution, permits us to conclude that both forms of adenine can adsorb chemically. The high sensitivity of the ATR-SEIRAS method has been used to analyze the contribution to the spectra of each form of adsorbed adenine as a function of the pH of the solution. The pKa2 obtained for the adsorbed species from this analysis is almost coincident with the pKa2 reported for adenine in solution, indicating that the coordination to the electrode and the second acid-base equilibrium involves different atoms of the adenine molecule. This result confirms the previously proposed adsorption model for adenine, implying the bonding of adenine to the electrode by the amine nitrogen (N10) and either the ring nitrogens N1 or N7, while the second acid-base equilibrium of adenine involves the ring nitrogen N9. Comparison of the 3400-3600 cm−1 region of the ATR-SEIRAS spectra of adenine obtained in H2O solutions at different pH values, which corresponds to the characteristic–OH stretching mode of the interfacial water molecules, permits us to discard the co-adsorption of water molecules in neutral and basic media, contrary to the case of adenine adsorption from acid media. Financial support from the Spanish Ministry of Science and Technology (CTQ2010-19823 and a FPU-grant to JAM), from the Junta de Andalucia (PAI FQM202) and University of Alicante.

The theory of "two-dimensional voltammetry" using arrays of gold channel microband electrodes ranging in size from the millimeter to the micrometer scale is extended to permit the deduction of electrochemical rate constants through the analysis of hydrodynamic voltammograms as a function of both electrode size and electrolyte flow rate (convection). The technique is applied to the reduction of p-chloranil and the oxidation of 2,3,7,8-tetramethoxythianthrene both in acetonitrile solution and electrochemical rate constants are reported.

Electrochemical measurements of impedance at dioleoylphosphatidylcholine (DOPC) coated mercury electrodes have been applied to several experimental situations and carried out using different procedures. Firstly the DOPC and gramicidin-modified DOPC coated electrodes were studied in the absence of electroactive species in solution. Secondly the gramicidin-modified DOPC coated mercury electrode was studied in the presence of Tl + ions in solution. The procedures consisted of: (i) potential and frequency sweeps on a single adsorbed DOPC monolayer, (ii) potential and frequency sweeps on a single adsorbed DOPC layer including an electrochemical pre-treatment before every perturbation step and (iii) experiments each carried out at successive frequencies or potentials on successively formed adsorbed DOPC monolayers respectively. The guidelines to be followed in order to check the consistency of the results and to establish the most suitable experimental conditions are outlined in the paper. The results are compared to similar experiments on uncoated hanging mercury electrodes in order to explain the observed behaviour.