Volcanoestratigrafía y evolución geológica de La Gomera

La isla de la Gomera (379 km2) esta situada en la parte occidental del archipiélago canario. Sus características geológicas son muy diferentes a las de las otras islas menores (La Palma y Hierro), pues es mucho más antigua y es la única en la que no existe actividad volcánica cuaternaria. La hace también especial el que para los modelos de génesis del archipiélago que suponen la existencia de una migración de la actividad volcánica de este a oeste, representa la excepción, pues se sitúa al oeste a pesar de ser casi tan antigua como otras islas más orientales

Herramientas y estrategias para diseñar rutas enzimáticas libres de células

The text deals with the technology of enzymes and biocatalysis as green alternatives to the conventional chemical synthesis of chemicals, especially drugs. Enzymes are catalysts that have high specificity and can operate in moderate and environmentally friendly conditions. However, their industrial use has been limited by the problems of using living cells as hosts for the enzymes. For this reason, cell-free synthesis has been developed, which consists of assembling several enzymes from different metabolic pathways to produce molecules of interest without cellular interference. This method offers more flexibility and control to optimize the production system.El texto trata sobre la tecnología de enzimas y la biocatálisis como alternativas verdes a la síntesis química convencional de productos químicos, especialmente fármacos. Las enzimas son catalizadores que tienen una alta especificidad y pueden operar en condiciones moderadas y respetuosas con el medio ambiente. Sin embargo, su uso industrial se ha limitado por los problemas de usar células vivas como huéspedes de las enzimas. Por eso, se ha desarrollado la síntesis sin células, que consiste en ensamblar varias enzimas de diferentes rutas metabólicas para producir moléculas de interés sin interferencias celulares. Este método ofrece más flexibilidad y control para optimizar el sistema de producción

Changes in toxins, intracellular and dissolved free amino acids of the toxic dinoflagellate Gymnodinium catenatum in response to changes in inorganic nutrients and salinity

19 páginas, 7 figuras, 2 tablas.The paralytic shellfish poison prducing dinoflagellate Gymnodiniun catemrum was subjected to changes in salinity, phosphate, ammonium and nitrate using continuous culture and batch culture methods. In contrast with other algae, this species showed very slow changes in the concentration of intracellular amino acids, in the Gln:Glu ratio, and, in contrast with Alrsandnum spp., only slow changes in toxin content, during such events as N-feeding of Ndeprived cells or during nutrient deprivation. This organism was found to be very susceptible to disturbance; maximum growth rates around 0.25–0.3 day–1 with a minimum C:N mass ratio of 5.5, were attained when cultures were only disturbed by sampling once a day. P-deprived cells were larger (twice the usual C content of 4 ng C cell–1 and volume of 20 pl). The content of free amino acids was always low (5% of cell-N), with low contributions made by arginine (the precursor for paralytic shellfish toxins). Cells growing using ammonium had the lowest C:N ratios and the highest proportion of intracellular amino acids as arginine. The toxin profile (equal mole ratios of dcSTX, GTX5, dcGT2/3 C1 and C2, and half those values for C3 and C4) was stable and the toxin concentration varied between 0.2 and 1 mM STX equivalents (highest when ammonium was not limiting, lowest in P-deprived cells, though as the latter were larger toxin per cell was not so variable). Decreased salinity did not result in increases in toxin content. Significant amounts of amino acids (mainly serine and glycine, with a total often exceeding 4 µM) accumulated in the growth medium during batch growth even though the cultures were not bacteria free.This work was funded by the Natural Environment Research Council (UK) through grants to K.J.F. and a studentship to E.H J. We also acknowledge funding received from the Spanish CICYT: projects MAR95-1791 to B.R. and ALI95- 1012-C05-01 to J.M.F.; the IEO-ESF grant to M.I.R., and the scholarship from Xunta de Galicia which funded M.I.R.'s visit to Swansea.Peer reviewe

Changes in nutritional quality-related traits of quinoa seeds under different storage conditions

Within the context of climate change and its impact on global food security, seed storage has become key, as it ensures long-term food and next-season seed preservation. Aiming at evaluating quality-related changes in quinoa seeds over storage time, different storage temperatures (–20, 4, 12, 25, and 37°C) and humidity conditions (use of silica gel or not) were studied and different seed nutritional parameters were evaluated at different points during a year of storage. Also, to determine if these variations could be conditioned by the genotype used, two quinoa cultivars were compared. The results proved that quinoa seed quality is highly dependent on the storage temperature but is not consistently affected by the use of silica gel if the seed moisture content (SMC) is kept between 5 and 12%. Furthermore, quality can be maintained and even improved by keeping SMC lower than 12% and storage temperatures low (4°C). Under these conditions (at 4°C in hermetic packaging with or without silica gel), and after 12 months of storage, there was an increase in amino acids like isoleucine, serine, arginine, glycine, and glutamic acid and in seed viability and germination. On the contrary, quinoa seeds stored at 37°C showed an accumulation of reactive oxygen species (ROS) which was related to a lower antioxidant capacity and a reduction in the contents of essential amino acids like isoleucine, lysine, histidine, and threonine, resulting in a delayed and reduced germination capacity, and, therefore, lower seed quality. Besides, quality-related differences appeared between cultivars highlighting differences linked to the genotype. Overall, this work demonstrates that optimal storage temperatures and SMC can preserve or even improve quinoa seed nutritional quality, which in turn can impact food safety and agricultureThis work was supported by the Ministerio de Ciencia e Innovación (MICINN, Spain) (PID2019-105748RA-I00), the Comunidad de Madrid-Universidad Autónoma de Madrid (SI1/PJI/2019-00124), the CYTED (ValSe-Food 119RT0567), the FPI-UAM Fellowship Programme 2019 (to SG-R), the Ayundante de Investigación CM Programme (to IM-G), and the Ramón y Cajal Programme 2019 (to M

The interplay between mechanics and stability of viral cages

The stability and strength of viral nanoparticles are crucial to fulfill the functions required through the viral cycle as well as using capsids for biomedical and nanotechnological applications. The mechanical properties of viral shells obtained through Atomic Force Microscopy (AFM) and continuum elasticity theory, such as stiffness or Young's modulus, have been interpreted very often in terms of stability. However, viruses are normally subjected to chemical rather than to mechanical aggression. Thus, a correct interpretation of mechanics in terms of stability requires an adequate linkage between the ability of viral cages to support chemical and mechanical stresses. Here we study the mechanical fragility and chemical stability of bacteriophage T7 in two different maturation states: the early proheads and the final mature capsids. Using chemical stress experiments we show that proheads are less stable than final mature capsids. Still, both particles present similar anisotropic stiffness, indicating that a continuum elasticity description in terms of Young's modulus is not an adequate measure of viral stability. In combination with a computational coarse-grained model we demonstrate that mechanical anisotropy of T7 emerges out of the discrete nature of the proheads and empty capsids. Even though they present the same stiffness, proheads break earlier and have fractures ten times larger than mature capsids, in agreement with chemical stability, thus demonstrating that fragility rather than stiffness is a better indicator of viral cages' stabilityWe acknowledge funding by grants from the Ministry of Science and Innovation of Spain, PIB2010US-00233, FIS2011-29493 and Consolider CSD2010-00024 (to P.J.P.), FIS2011-22603 and FIS2011-16090-E (D.R.), BFU2011-29038 (to J.L.C.), BFU2011-25902 (to J.R.C.) and the Comunidad de Madrid no. S2009/MAT-1467 (to P.J.P.) and S2009/MAT-1507 (to J.L.C.) We are grateful to M. García-Mateu (UAM), Julio Gómez-Herrero (UAM) and Red Española Interdisciplinar de Biofísica de los Virus (BioFiViNet), FIS2011-16090-E for expert technical help

The statute of the teaching and research staff. Any new or the usual roles?

Como consecuencia de la evolución legislativa en relación a la actividad del profesor universitario se ha elaborado un borrador del Estatuto del Personal Docente e Investigador (PDI). Éste se plantea como plataforma necesaria para alcanzar la excelencia en la realización de la docencia y la investigación para poder competir a nivel europeo y mundial. No obstante, ha suscitado la aparición de opiniones contrapuestas en cuanto a su articulado. Este trabajo tiene como objetivo explorar, mediante entrevistas semiestructuradas, la opinión del profesorado sobre aspectos clave del borrador. Los resultados indican que, si bien el profesorado considera necesaria la existencia del estatuto, manifiesta ciertas prevenciones sobre los posibles efectos negativos de su implantación.As a result of legislative developments in relation to the activity of the university professor has been elaborated a draft of the Statute of the Teaching and Research Staff (TRS). This is presented as necessary platform to achieve the excellence conducting the teaching and the investigation in order to compete at European and globally level. However, it has led to the appearance of conflicting views as to its provisions. This study aims to explore, through semi-structured interviews, the teacher opinion on key aspects of the draft. The results indicate that although the teachers consider necessary the existence of the statute, manifest certain warnings about the possible negative effects of its implementation

Methodological innovation in the professional master of teacher training: proyect-based learning from interdisciplinarity

Parece oportuno –una vez han pasado más de cinco años desde que las universidades españolas graduaron su primera promoción de alumnado, dentro de los nuevos parámetros europeos para la Educación Superior- resaltar los principales cambios que ello ha supuesto en la metodología docente universitaria. Por ese motivo presentamos, en este artículo, el diseño y análisis parcial de los resultados de un proyecto de innovación y buenas prácticas docentes (PIBD) –auspiciado por la UGR, y desarrollado en su Máster profesionalizante en formación de Profesorado de Enseñanza Secundaria (MAES)- considerando que estas iniciativas evidencian aquellos cambios metodológicos que se están llevando a cabo en la universidad pública española. El proyecto, que se ha desarrollado en el curso académico 2018-19, con n=107 (alumnos de la especialidad de Educación Física), tiene como principal objetivo la puesta en práctica de la metodología del aprendizaje basado en proyectos (ABPr) para que el alumnado del máster analice, diseñe y elabore materiales adhoc de la profesión docente. Para ello se han analizado los resultados –reportados por diferentes instrumentos fiables- en torno a la satisfacción del alumnado con la metodología docente empleada. Estos evidencian la elevada motivación de los estudiantes con la propuesta realizada, el desarrollo de un aprendizaje significativo (englobando los conocimientos adquiridos en las tres materias del módulo genérico) pero también señalan alguna limitación como, por ejemplo, la falta de tiempo para alcanzar productos de mayor calidad.It seems appropriate -once more than five years passed since Spanish universities graduated their first student promotion, within the new European parameters for Higher Education- to highlight the main changes that this has supposed in the university teaching methodology. For this purpose, we present, in this article, the design and analysis of an innovation project of good teaching practices (PIBD) -sponsored by the UGR, and developed in its professional Master in Secondary Educationconsidering that these initiatives are a reliable indicator of those effective changes that are happening in the Spanish public university. The study, which has been carried out in the academic year 2018-19, with n = 107 (students of the Physical Education specialty), has as its main objective the implementation of the methodology of project-based learning so that the students of the master analyze, design and elaborate adhoc materials of the teaching profession. For this purpose, the results –reported by different reliable instruments- have been analyzed around student satisfaction with the teaching methodology used. These show the high motivation of the students with the project carried out, the development of significant learning (encompassing the knowledge acquired in the three subjects of the generic module) but also point out some limitations such as, for example, the lack of time to achieve higher quality products

Antileishmanial activity of terpenylquinones on Leishmania infantum and their effects on Leishmania topoisomerase IB

[EN] Leishmania is the aethiological agent responsible for the visceral leishmaniasis, a serious parasite-borne disease widely spread all over the World. The emergence of resistant strains makes classical treatments less effective; therefore, new and better drugs are necessary. Naphthoquinones are interesting compounds for which many pharmacological properties have been described, including leishmanicidal activity. This work shows the antileishmanial effect of two series of terpenyl-1,4-naphthoquinones (NQ) and 1,4-anthraquinones (AQ) obtained from natural terpenoids, such as myrcene and myrceocommunic acid. They were evaluated both in vitro and ex vivo against the transgenic iRFP-Leishmania infantum strain and also tested on liver HepG2 cells to determine their selectivity indexes. The results indicated that NQ derivatives showed better antileishmanial activity than AQ analogues, and among them, compounds with a diacetylated hydroquinone moiety provided better results than their corresponding quinones. Regarding the terpenic precursor, compounds obtained from the monoterpenoid myrcene displayed good antiparasitic efficiency and low cytotoxicity for mammalian cells, whereas those derived from the diterpenoid showed better antileishmanial activity without selectivity. In order to explore their mechanism of action, all the compounds have been tested as potential inhibitors of Leishmania type IB DNA topoisomerases, but only some compounds that displayed the quinone ring were able to inhibit the recombinant enzyme in vitro. This fact together with the docking studies performed on LTopIB suggested the existence of another mechanism of action, alternative or complementary to LTopIB inhibition. In silico druglikeness and ADME evaluation of the best leishmanicidal compounds has shown good predictable druggabilitySIFinancial support came from Spanish MINECO (CTQ2015-68175-R, AGL2016-79813-C2-1-R, AGL2016-79813-C2-2-R and SAF2017-83575-R), ISCIII-RICET Network (RD12/0018/0002) and Consejería de Educación de la Junta de Castilla y León (LE020P17) co-financed by the Fondo Social Europeo of the European Union (FEDER-EU). P. G. J. acknowledges funding by Fundación Salamanca Ciudad de Cultura y Saberes (’‘Programme for attracting scientific talent to Salamanca’‘