Nuevos materiales para la especiación de mercurio: biotransformación de metales en organismos modelo

La contaminación medioambiental representa un problema de gran importancia en la actualidad. Estamos acostumbrados a escuchar por los medios de comunicación los numerosos casos que suceden a nuestro alrededor: la contaminación de ríos, lagos o playas por vertidos residuales; la contaminación de los suelos por utilización indebida de ciertos fertilizantes o por las actividades mineras de la zona; o la contaminación del aire ocasionada por el masivo número de automóviles y zonas industriales en las ciudades provocando las famosas “boinas” de las grandes ciudades. En el caso de los metales pesados o metaloides, pueden acumularse y biomagnificarse a lo largo de la cadena trófica llegando a provocar efectos nocivos en los seres humanos. Los contaminantes clásicos estudiados en esta tesis engloban el mercurio, arsénico, cadmio y plata. Entre todos ellos el mercurio y el arsénico son los que mayor repercusión medioambiental representan. El mercurio es un metal cuya toxicidad es muy elevada pero su repercusión en los efectos provocados en los seres vivos depende de la forma química en la que se encuentre en el medio. Las dos especies predominantes son mercurio inorgánico (Hg2+) y metilmercurio (CH3Hg+). El arsénico es un metaloide donde sus compuestos inorgánicos presentan mayor toxicidad. La contaminación de arsénico en agua y suelos supone un problema que afecta a millones de personas en Asia y en la zona Andina. El cadmio al igual que ocurre con el mercurio, es un elemento con gran tendencia a bioacumularse en la cadena trófica, estando relacionado con el cáncer de pulmón, próstata o renal. La exposición puede ser a través de la dieta o por inhalación de vapores; los fumadores incrementan esta exposición en un 50%. La plata es un elemento que encontramos en multitud de aplicaciones, principalmente en la energía solar, en el campo de la fotografía y en algunos medicamentos. Una exposición elevada provoca argiria en la piel u ojos. Existen otros contaminantes, los denominados emergentes, que son aquellos que debido a un aumento de las aplicaciones nanotecnológicas y del uso de nanopartículas, los podemos encontrar en el medio ambiente y sus efectos aún no están definidos, siendo actualmente objeto de estudio, como las nanopartículas de quantum dots (QDs), constituidas por seleniuro de cadmio principalmente. La toxicidad de estos QDs depende del recubrimiento de la nanopartícula, del tamaño y de la carga..

Environmental education through musical education

La Educación Ambiental supone un reto importante para la actualidad. Atendiendo a la situación crítica de nuestro planeta y con la obligación moral de sensibilizar al alumno en sus primeros años se pretende, utilizando el carácter interdisciplinario de la Educación Musical, dar a conocer las diferentes posturas y elementos que ambas áreas tienen en común. Este supone un primer paso indispensable y necesario, antes de realizar una posible propuesta de intervención pedagógicaEnvironmental Education is a major challenge for today. Attending to the critical situation of our planet and with the moral obligation to sensitize the student in its early years it is intended, by means of the interdisciplinary nature of Music Education, to release the different positions and elements that both areas have in common. This is an essential and necessary first step, before making a possible proposal for pedagogical interventio

Classdojo: a gamification and communication tool for the improvement of the educational process

En este estudio se aborda la influencia que pueden tener herramientas de gamificación y comunicación en el proceso educativo, más concretamente en la etapa de la Educación Primaria. Se presenta la plataforma y aplicación ClassDojo como una de las más atractivas para ello y con una aportación motivacional bastante relevante en el alumnado. A través de este estudio realizaremos una visión pormenorizada de las diferentes funcionalidades que nos otorga la herramienta para ello.This study addresses the influence that gamification and communication tools may have on the educational process, more precisely in the stage of Primary Education. The ClassDojo platform and application is presented as one of the most attractive for this field and with a very relevant motivational contribution in the students. Through this study we will carry out a a detailed view of the different functionalities that the tool gives us

Cytokinin Determines Thiol-Mediated Arsenic Tolerance and Accumulation

The presence of arsenic in soil and water is a constant threat to plant growth in many regions of the world. Phytohormones act in the integration of growth control and stress response, but their role in plant responses to arsenic remains to be elucidated. Here, we show that arsenate [As(V)], the most prevalent arsenic chemical species in nature, causes severe depletion of endogenous cytokinins (CKs) in the model plant Arabidopsis (Arabidopsis thaliana). We found that CK signaling mutants and transgenic plants with reduced endogenous CK levels showed an As(V)-tolerant phenotype. Our data indicate that in CK-depleted plants exposed to As(V), transcript levels of As(V)/phosphate-transporters were similar or even higher than in wild-type plants. In contrast, CK depletion provoked the coordinated activation of As(V) tolerance mechanisms, leading to the accumulation of thiol compounds such as phytochelatins and glutathione, which are essential for arsenic sequestration. Transgenic CK-deficient Arabidopsis and tobacco lines show a marked increase in arsenic accumulation. Our findings indicate that CK is an important regulatory factor in plant adaptation to arsenic stress

Response to Arsenate treatment in Schizosaccharomyces pombe and the role of its Arsenate reductase activity

Arsenic toxicity has been studied for a long time due to its effects in humans. Although epidemiological studies have demonstrated multiple effects in human physiology, there are many open questions about the cellular targets and the mechanisms of response to arsenic. Using the fission yeast Schizosaccharomyces pombe as model system, we have been able to demonstrate a strong activation of the MAPK Spc1/Sty1 in response to arsenate. This activation is dependent on Wis1 activation and Pyp2 phosphatase inactivation. Using arsenic speciation analysis we have also demonstrated the previously unknown capacity of S. pombe cells to reduce As (V) to As (III). Genetic analysis of several fission yeast mutants point towards the cell cycle phosphatase Cdc25 as a possible candidate to carry out this arsenate reductase activity. We propose that arsenate reduction and intracellular accumulation of arsenite are the key mechanisms of arsenate tolerance in fission yeast.Spanish Science and Innovation Ministry (CTQ2008-01031/BQU, BFU2006/01767, BFU2009/09116)Peer Reviewe

Response to arsenate treatment in Schizosaccharomyces pombe and the role of its arsenate reductase activity.

Arsenic toxicity has been studied for a long time due to its effects in humans. Although epidemiological studies have demonstrated multiple effects in human physiology, there are many open questions about the cellular targets and the mechanisms of response to arsenic. Using the fission yeast Schizosaccharomyces pombe as model system, we have been able to demonstrate a strong activation of the MAPK Spc1/Sty1 in response to arsenate. This activation is dependent on Wis1 activation and Pyp2 phosphatase inactivation. Using arsenic speciation analysis we have also demonstrated the previously unknown capacity of S. pombe cells to reduce As (V) to As (III). Genetic analysis of several fission yeast mutants point towards the cell cycle phosphatase Cdc25 as a possible candidate to carry out this arsenate reductase activity. We propose that arsenate reduction and intracellular accumulation of arsenite are the key mechanisms of arsenate tolerance in fission yeast

Genotypes of <i>Schizosaccharomyces pombe</i> strains used in this work.

<p>Genotypes of <i>Schizosaccharomyces pombe</i> strains used in this work.</p

Instrumental parameters for As determination by LC/ICP/MS.

<p>Instrumental parameters for As determination by LC/ICP/MS.</p

Spc1 MAPK pathway and the response to arsenate.

<p>A. Serial dilutions of wild type, <i>wis1</i>Δ, <i>mcs4</i>Δ, <i>wis4</i>Δ, <i>win1-1</i> and <i>wis4</i>Δ <i>win1-1</i> strains were plated in rich media (YES) or rich media containing 50 µM sodium arsenate. Pictures were taken after incubation at 30°C for 48 hours. B. Western blotting of purified Spc1 extracts from wild type, <i>wis1</i>Δ, <i>wis1-AA</i>, <i>win1-1, wis4</i>Δ, and <i>win1-1 wis4</i>Δ treated with 100 µM sodium arsenate for 0 to 30 minutes. Antibodies against phosphorylated p38 were used. As a control, antibodies against HA epitope were used. C. Western blotting of purified Spc1 extracts from wild type, <i>wis1</i>Δ, <i>win1-1 wis4</i>Δ, <i>win1-1 wis4</i>Δ <i>pyp1</i>Δ and <i>win1-1 wis4</i>Δ <i>pyp2</i>Δ treated with 100 µM sodium arsenate for 0 to 30 minutes. Antibodies against phosphorylated p38 were used. As a control, antibodies against HA epitope were used.</p

Arsenic speciation in different fission yeast mutants.

<p>Total cell extracts from 5×10⁷ cells and growth media from wild type, <i>spc1</i>Δ, <i>cdc2-3w</i> and <i>cdc25</i>Δ <i>cdc2-3w</i> strains were obtained after treatment for 3 or 9 hours with 100 µM sodium arsenate. Graph shows the amount of As (V) (A) or As (III) (B) present in the extracts or growth media.</p