Mapping the secondary star in QQ Vulpeculae

We present high- and medium-resolution phase-resolved far-red spectra of the magnetic cataclysmic variable QQ Vul. The spectra show the Na i doublet absorption features near λ 8190 Å from the cool secondary star, and the lines of He ii, O i, Mg ii, C i, N i, Ca ii and Paschen in emission. Using a Doppler imaging technique, we find that the H i, He ii, C i and O i lines have a narrow component originating near the L1 point and a strong component from the stream, while the Mg ii and Ca ii emission arises solely from the illuminated hemisphere of the red dwarf. We carry out an exhaustive analysis of the emission- and absorption-line velocities and fluxes seen in the QQ Vul spectrum. By simultaneously fitting the radial velocity and flux information we are able to produce surface maps of each line on the secondary star using a technique analogous to the one employed by Davey. The Na i and Mg ii maps show an asymmetric distribution akin to that seen in AM Her. Although the observed velocity semi-amplitudes (K2) of the lines can potentially be corrected for the effects of irradiation, we find that time-dependent changes in the degree of heating on the secondary can lead to large discrepancies in the results, significant enough to give inconsistent values from data taken at different epochs. We discuss the limitations of the surface mapping method as a means of correcting the observed K2. Our results also suggest that the emission features from the red dwarf are likely to be formed at quite high levels of the stellar chromosphere, in some cases probably even beyond the L1 point and inside the Roche lobe of the white dwarf, with the different lines possibly forming at different depths. Using the Na i absorption doublet, we find a velocity semi-amplitude for the secondary star of K2=219±6 km s−1 and a projected rotational velocity of vrot sin i=110±15 km s−1. Thus we estimate the mass ratio to be q=0.54±0.14. Based on the results of the best-fitting surface maps on all the lines, and the nature of the phase-dependent variations of the continuum and lines, we infer a binary inclination of i=65°±7°, and obtain a complete set of binary parameters for QQ Vul. We classify the secondary star as M4V from the TiO band ratios

ELECTROCHEMICAL CHARACTERIZATION OF NEW 1,5-BENZODIAZEPINE DERIVATIVES

Indexación: Web of Science; Scielo.Cyclic voltammetry was used to study the electrochemical behavior of new 1,5-benzodiazepine derivatives on a glassy carbon electrode. Well-defined oxidation peaks were observed in DMSO. The Electrochemical response of the glassy carbon electrode was evaluated as function of the scan rate, showing that the electron transfer process for compound (5) and (6) resulted to be controlled by diffusion.http://ref.scielo.org/3nfd9

La macroflora oligocena de la cuenca de Cervera, Lérida, España (Colección del Museu Comarcal de Cervera)

This paper is the follow-up of another study of the Oligocene macroflora from Cervera (Ebro Basin, Spain), started with the 'Madern Collection' from the Museu de Geologia de Barcelona (Sanz de Siria, 1992). The present paper analyses 226 specimen from the Museu Comarcal de Cervera. 29 species, not mentioned before, are included and 3 new species of the tertiary flora are established. A likely model of the vegetation existing in the area in the low Oligocene is established by comparision with the models existing today of similar content and structure. Similar models are presently located in tropical regions between 15o and 25o latitude north. The main vegetal community that has been found correspond to the tropical deciduous forest. In upper, wetter levels, evergreen forest with laurisilva communities appear. The climate in the low Oligocene in the region was probably of the tropicalk kind, with a long dry period followed by a rain period. The average temperature would be around 22o-26o. Key words: Paleobotany, Macroflora, Oligocene, Paleoecology, Ebro Basin, Cervera, Spain, Museu Comarcal de Cervera.En el presente trabajo se prosigue el estudio de la flora oligocena de Cervera (Lérida, España) iniciado con la 'Colección Madern' del Museu de Geologia de Barcelona (Sanz de Siria, 1992). Se estudian ahora 226 ejemplares depositados en el Museu Comarcal de Cervera. Se menciona la presencia de 29 especies no citadas anteriormente y se crean 3 especies nuevas para la flora terciaria. Asimismo, se determina el posible modelo de vegetación existente en la zona durante el Oligoceno, por comparación con los modelos actuales de parecida composición y estructura. Modelos similares se localizan actualmente en regiones tropicales, entre los 15o y los 25o de latitud Norte. La principal comunidad vegetal encontrada corresponde a bosques tropicales deciduos. En niveles superiores más húmedos aparecen bosques perennifolios de tipo laurisilva. El clima de la región, durante el Oligoceno inferior, parece que fue de tipo tropical, con una estación seca prolongada seguida de un período de lluvias. Las temperaturas medias anuales podrían situarse entre los 22o-26o. Palabras clave: Paleobotánica, Macroflora, Oligoceno, Paleoecología, Cuenca del Ebro, España, Museu Comarcal de Cervera

Estudio paleoecológico y paleoclimático de la macroflora oligocena de Cervera (Lleida, España)

After the taxonomic revision of the macroflora from Cervera (Lleida, Spain) of the 'Martí Madern' (Museu de Geologia de Barcelona and Museu Comarcal de Cervera collections). We present here their palaeoecological and palaeoclimatic study. A likely model of the vegetation existing in the area in the low Oligocene is established by comparison with the models existing today of similar content and structure. Similar models are presently located in tropical regions about 20o latitude North. The main vegetal community that has been found corresponds to the tropical deciduous forest. In superior wetter levels, evergreen forest with laurisilva communities appears. The climate in the early Oligocene in the region was probably of the tropical kind, with a long dry period followed by a rain period. The average temperature would be around 22o - 26o. Key words: Palaeobotany, Macroflora, Oligocene, Palaeoecology, Palaeoclimatology, Ebro Basin, Cervera, Spain.Este trabajo es continuación de las revisiones taxonómicas realizadas de las colecciones de macroflora fósil 'Martí Madern', del Museu se Geologia de Barcelona y del Museu Comarcal de Cervera. Partiendo del estudio del conjunto de taxones fósiles hallado, se obtienen datos paleoecológicos y paleoclimáticos acerca de la cuenca y se intenta establecer el modelo de vegetación que debió existir durante el Oligoceno en esa zona. La principal comunidad vegetal presente correspondió a bosques deciduos de tipo tropical. En niveles superiores se ubicaron bosques perennifolios semejantes a las actuales laurisilvas. El clima en la región en el Oligoceno inferior fue de tipo tropical, con una estación seca prolongada a la que seguía un período de lluvias. Las temperaturas medias podían situarse en torno a los 22o-26o. Palabras clave: Paleobótanica, Macroflora, Oligoceno, Paleoecología, Paleoclimatología, Cuenca del Ebro, Cervera, España

Effects of Liposomes Contained in Thermosensitive Hydrogels as Biomaterials Useful in Neural Tissue Engineering

Indexación: Scopus.Advances in the generation of suitable thermosensitive hydrogels for the delivery of cells in neural tissue engineering demonstrate a delicate relationship between physical properties and capabilities to promote cell proliferation and differentiation. To improve the properties of these materials, it is possible to add liposomes for the controlled release of bioactive elements, which in turn can affect the physical and biological properties of the hydrogels. In the present investigation, different hydrogels based on Pluronic F127 have been formulated with the incorporation of chitosan and two types of liposomes of two different sizes. The rheological and thermal properties and their relation with the neurite proliferation and growth of the PC12 cell line were evaluated. Our results show that the incorporation of liposomes modifies the properties of the hydrogels dependent on the concentration of chitosan and the lipid type in the liposomes, which directly affect the capabilities of the hydrogels to promote the viability and differentiation of PC12 cells. © 2017 by the authors.http://www.mdpi.com/1996-1944/10/10/112

Representaciones en torno a las competencias de los formadores de profesores de biología de la provincia de Buenos Aires (Argentina)

Las exigencias actuales para integrarse en la sociedad del conocimiento ponen en crisis los contenidos formativos del profesorado. Esto nos llevó a estudiar el campo de las competencias situándolas en el contexto de la renovación de los enfoques formativos. Nos interesó conocer las representaciones que poseen los formadores sobre las competencias propias de su función, confrontándolas con las propuestas sobre el tema. Tomamos como referente la categorización de las competencias de referencia (CR) de Perrenoud (2004). Hallamos una marcada coincidencia con las CR en el papel a desarrollar por un profesor de biología en la escuela secundaria en los siguientes aspectos: su formación continua, los estudiantes, los contenidos y las estrategias didácticas

Relaciones entre concepciones y conocimiento especializado (MTSK) acerca de clasificación de figuras planas

Este póster muestra algunos resultados de un trabajo doctoral que aborda cómo el conocimiento especializado de una maestra de Educación Primaria sobre la clasificación de las figuras planas se relaciona con las concepciones de ésta sobre la Enseñanza y Aprendizaje de la matemática (Aguilar, 2016)

Influence of hydrogen peroxide in the tribocorrosion behaviour of a CoCrMo biomedical alloy

This paper studies the influence of hydrogen peroxide (H2O2) in simulated body fluids on the wear and corrosion behaviour of a CoCrMo biomedical alloy. CoCrMo are passive materials commonly used in prosthesis and implants because of its high corrosion resistance and mechanical properties. Hydrogen peroxide is produced by bacteria and leukocytes as a consequence of an inflammatory reaction which may modify the tribo-electrochemical response of metals implanted in the human body. Indeed, the oxidizing environment generated by the presence of the peroxide increases the metal dissolution rate. Electrochemical and tribocorrosion tests were carried out in a PBS solution with different addition of H2O2 (0.5, 2, 4 and 12%).The authors acknowledge Generalitat Valencia for the Gerónimo Forteza financial support and to the Electron Microscopy Service of the UPV for the SEM images

Adapting the revised prenatal coping inventory (NuPCI) for use in a Spanish population

Objective: To adapt the Revised Prenatal Coping Inventory (NuPCI) for the evaluation of prenatal stress coping strategies utilised by Spanish women. Methods: A cross-sectional study was performed to evaluate the psychometric properties of NuPCI adapted for a Spanish population. Two hundred and sixty one puerperium women completed the NuPCI at the time of discharge after childbirth. Instrument construct validity was evaluated using subscale item correlations. Internal consistency was assessed using Cronbach’s a test. Results: Items from each subscale (Preparation, Avoidance and Spiritual – Positive Coping) were significantly correlated with the global result (p¿¿0.7). The most frequently used coping strategy was Preparation and the least used was Avoidance. Utilisation of the coping strategies with Preparation decreased with increasing parity (p¿=¿.002) and greater prenatal stress was associated with increased use of the Avoidance coping strategy (p¿<¿.001). Conclusions: The NuPCI adapted for Spanish women demonstrates good psychometric properties for evaluating the three types of prenatal stress coping strategies: Preparation, Avoidance and Spiritual – Positive Coping. Results were similar to those presented by the instrument in its English language version