Les propietats coordinants de les metal·lotioneïnes del C. elegans

Un equip d'investigadors, format per químics de la UAB i biòlegs de la UB, ha estudiat el sistema de metal·lotioneïnes del nematode Caenorhabditis elegans, un organisme model en estudis de biologia molecular. Malgrat que a les metal·lotioneïnes se'ls han atribuït diverses funcions biològiques com la detoxicació de metalls pesants, encara es treballa amb intensitat per determinar la seva funció específica. Aquest treball ha desvetllat les propietats coordinants dels dos tipus de metal·lotioneïnes presents en C. elegans.Un equipo de investigadores, formado por químicos de la UAB y biólogos de la UB, ha estudiado el sistema de metalotioneínas del nematodo Caenorhabditis elegans, un organismo modelo en estudios de biología molecular. Pese a que a las metalotioneínas se les han atribuido varias funciones biológicas, como la detoxificación de metales pesados, todavía se trabaja con intensidad para determinar su función específica. Este trabajo ha puesto a descubierto las propiedades coordinantes de los dos tipos de metalotioneínas presentes en C. elegans.A research team made up of chemists of the UAB and biologists of the UB has studied the metallothionein system of the nematode Caenorhabditis elegans, a model organism in molecular biology. Although metallothioneins have been related to different functions in the organism, such as heavy metal detoxification, intense work is still being caried out to determine their specific functionality. The research has discovered the binding properties of the two known metallothioneins in C. elegans

Morphological and chemical analysis of male scent organs in the butterfly genus Pyrgus (Lepidoptera: Hesperiidae)

Chemical communication in the family Hesperiidae (Lepidoptera) is practically unstudied, even though this group includes approximately 4,000 species and represents a fifth of the world's butterfly fauna. We present the first comparative morphological and chemical analysis of scent organs for nine species in the genus Pyrgus, the most species-rich hesperiid genus in the Palearctic region. Our results show that the morphology of the two main male scent organs - the costal fold and the tibial tufts - does not differ between species. The chemical analyses detected a total of 125 different compounds exclusively present in these organs. We document great interspecific differences and much narrower intraspecific variability in the chemical profiles. The dynamics of chemical versus genetic distances indicate two different phases: a faster (but more variable) initial chemical divergence at lower genetic divergences (probably related to speciation) and a slower but more constant differentiation (drift). As a result most species can be identified based on their chemical profiles, except for a closely related species pair (P. malvae/P. malvoides) for which hybridisation is common in the contact zone. Our results suggest that the Hesperiidae is a group with great potential for the study of chemical communication that deserves further attention. © 2014 Gesellschaft für Biologische Systematik.Funding for this research was provided by Universitat Autònoma de Barcelona (project EME2007-33 to J.L.H.-R., R.B. and R.V.) and by the Spanish Ministerio de Ciencia e Innovación (project CGL2010-21226/BOS to J.L.H.-R. and R.V. and project CGL2004-04680-c10-08/BOS to M.L.M.).Peer Reviewe

Chemical, electrochemical and photochemical molecular water oxidation catalysts

Hydrogen release from the splitting of water by simply using sunlight as the only energy source is an old human dream that could finally become a reality. This process involves both the reduction and oxidation of water into hydrogen and oxygen, respectively. While the first process has been fairly overcome, the conversion of water into oxygen has been traditionally the bottleneck process hampering the development of a sustainable hydrogen production based on water splitting. Fortunately, a revolution in this field has occurred during the past decade, since many research groups have been conducting an intense research in this area. Thus, while molecular, well-characterized catalysts able to oxidize water were scarce just five years ago, now a wide range of transition metal based compounds has been reported as active catalysts for this transformation. This review reports the most prominent key advances in the field, covering either examples where the catalysis is triggered chemically, electrochemically or photochemicall

Grup de Recerca Catàlisi d'Oxidació Selectiva (SelOxCat)

La demanda energètica de les societats actuals és cada vegada més elevada, mentre que les reserves de combustibles d'origen no renovable, les més utilitzades, van minvant. En aquesta situació, la recerca de fonts d'energia renovables adquireix una importància rellevant. El grup de recerca SelOxCat (Catàlisid'Oxidació Selectiva) utilitza una àmplia gamma de tècniques per tal d'estudiar, comprendre i desenvolupar les reaccions principals per a la producció de combustibles renovables a partir d'aigua i llum solar.La demanda energética de las sociedades actuales es cada vez más elevada, mientras que las reservas de combustibles de origen no renovable, las más utilizadas, van disminuyendo. En esta situación, la búsqueda de fuentes de energía renovables adquiere una importancia relevante. El grupo de investigación SelOxCat (Catálisis de Oxidación Selectiva) utiliza una amplia gama de técnicas para estudiar, comprender y desarrollar las reacciones principales para la producción de combustibles renovables a partir de agua y luz solar.The energy demand of modern societies is increasingly high, while the reserves of non-renewable fuel sources, the most common, are diminishing. In this situation, the search for renewable energy sources acquires considerable importance. The SelOxCat research group uses a range of techniques to study, understand and develop the reactions leading to the production of renewable fuels from water and sunlight

Barcelona OpenMP tasks suite: a set of benchmarks targeting the exploitation of task parallelism in OpenMP

Traditional parallel applications have exploited regular parallelism, based on parallel loops. Only a few applications exploit sections parallelism. With the release of the new OpenMP specification (3.0), this programming model supports tasking. Parallel tasks allow the exploitation of irregular parallelism, but there is a lack of benchmarks exploiting tasks in OpenMP. With the current (and projected) multicore architectures that offer many more alternatives to execute parallel applications than traditional SMP machines, this kind of parallelism is increasingly important. And so, the need to have some set of benchmarks to evaluate it. In this paper, we motivate the need of having such a benchmarks suite, for irregular and/or recursive task parallelism. We present our proposal, the Barcelona OpenMP Tasks Suite (BOTS), with a set of applications exploiting regular and irregular parallelism, based on tasks. We present an overall evaluation of the BOTS benchmarks in an Altix system and we discuss some of the different experiments that can be done with the different compilation and runtime alternatives of the benchmarks.Peer ReviewedPostprint (published version

The sea urchin metallothionein system: Comparative evaluation of the SpMTA and SpMTB metal-binding preferences.

Metallothioneins (MTs) constitute a superfamily of ubiquitous metal-binding proteins of low molecular weight and high Cys content. They are involved in metal homeostasis and detoxification, amongst other proposed biological functions. Two MT isoforms (SpMTA and SpMTB) have been reported in the echinoderm Strongylocentrotus purpuratus (sea urchin), both containing 20 Cys residues and presenting extremely similar sequences, although showing distinct tissular and ontogenic expression patterns. Although exhaustive information is available for the Cd(II)-SpMTA complex, this including the full resolution of its 3D structure, no data has been reported concerning either SpMTA Zn(II) and Cu(I) binding properties, or the characterization of SpMTB at protein level. In this work, both the SpMTA and SpMTB isoforms, as well as their separate α and β domains, have been recombinantly synthesized in the presence of Zn(II), Cd(II) or Cu(II), and the corresponding metal complexes have been analyzed using electrospray mass spectrometry, and CD, ICP-AES and UV-vis spectroscopies. The results clearly show a better performance of isoform A when binding Zn(II) and Cd(II), and of isoform B when coordinating Cu(I). Thus, our results confirm the differential metal binding preference of SpMTA and SpMTB, which, together with the reported induction pattern of the respective genes, highlights how also in Echinodermata the MT polymorphism may be linked to the evolution of different physiological roles

Light-driven hydrogen evolution assisted by covalent organic frameworks

Altres ajuts: RSCCovalent organic frameworks (COFs) are crystalline porous organic polymers built from covalent organic blocks that can be photochemically active when incorporating organic semiconducting units, such as triazine rings or diacetylene bridges. The bandgap, charge separation capacity, porosity, wettability, and chemical stability of COFs can be tuned by properly choosing their constitutive building blocks, by extension of conjugation, by adjustment of the size and crystallinity of the pores, and by synthetic post-functionalization. This review focuses on the recent uses of COFs as photoactive platforms for the hydrogen evolution reaction (HER), in which usually metal nanoparticles (NPs) or metallic compounds (generally Pt-based) act as co-catalysts. The most promising COF-based photocatalytic HER systems will be discussed, and special emphasis will be placed on rationalizing their structure and light-harvesting properties in relation to their catalytic activity and stability under turnover conditions. Finally, the aspects that need to be improved in the coming years will be discussed, such as the degree of dispersibility in water, the global photocatalytic efficiency, and the robustness and stability of the hybrid systems, putting emphasis on both the COF and the metal co-catalyst

Análisis de estabilidad y simulaciones de desprendimientos en canteras a partir de modelos 3D obtenidos con vuelos de dron

Se presentan dos casos en canteras donde se trabaja a partir de un modelo 3D del terreno obtenido mediante la reconstrucción fotogramétrica con dron. El primer caso se centra en la delimitación detallada de una masa rocosa inestable y se comparan los resultados de análisis de estabilidad realizados con cuatro metodologías: test cinemático, equilibrio límite mediante el programa RocPlane y equilibrio límite con métodos numéricos en 2D y 3D mediante los programas Slide2D y Slide3D, todos ellos de Rocscience. Se comparan los resultados obtenidos considerando distintos valores de cohesión y ángulo de fricción obtenidos de ensayos de laboratorio sobre el plano de deslizamiento y se debate sobre las incertidumbres que controlan la estabilidad como la presencia de agua y la cohesión. El segundo caso muestra el estudio de una propuesta de geometría futura de taludes muy verticales en una cantera. Se analiza, por un lado, la estabilidad de la geometría futura propuesta y se contrasta con las roturas existentes y, por otro lado, se comparan simulaciones de desprendimientos con la geometría actual y con la propuesta. Se utiliza el programa RockGIS desarrollado en la UPC que permite realizar simulaciones de desprendimientos en 3D y considerando el fenómeno de la fragmentación. Se debate sobre las ventajas e inconvenientes de la geometría propuesta en relación a la estabilidad de los taludes y del riesgo asociado a los desprendimientos. Los dos casos muestran el potencial de realizar un vuelo dron y trabajar a partir de un modelo 3D detallado de la cantera: la caracterización del patrón de discontinuidades de forma masiva, la caracterización de los mecanismos de rotura, la delimitación de volúmenes potencialmente inestable, la definición de la geometría necesaria para realizar análisis de estabilidad en 2D y 3D, así como el escenario donde realizar simulaciones de desprendimientos 3D.Postprint (published version

How can we improve energy efficiency through user-directed vectorization and task-based parallelization?

Heterogeneity, parallelization and vectorization are key techniques to improve the performance and energy efficiency of modern computing systems. However, programming and maintaining code for these architectures poses a huge challenge due to the ever-increasing architecture complexity. Task-based environments hide most of this complexity, improving scalability and usage of the available resources. In these environments, while there has been a lot of effort to ease parallelization and improve the usage of heterogeneous resources, vectorization has been considered a secondary objective. Furthermore, there has been a swift and unstoppable burst of vector architectures at all market segments, from embedded to HPC. Vectorization can no longer be ignored, but manual vectorization is tedious, error-prone, and not practical for the average programmer. This work evaluates the feasibility of user-directed vectorization in task-based applications. Our evaluation is based on the OmpSs programming model, extended to support user-directed vectorization for different SIMD architectures (i.e. SSE, AVX2, AVX512, etc). Results show that user-directed codes achieve manually-optimized code performance and energy efficiency with minimal code modifications, favoring portability across different SIMD architectures

Surface-Functionalized Nanoparticles as Catalysts for Artificial Photosynthesis

Altres ajuts: acords transformatius de la UABAnalogously to enzymatic catalysis, where the active metal sites and their environment are controlled by protein residues, the catalytic properties of metal nanoparticles (NPs) can be tuned by carefully selecting their surface-coordinated species. In artificial photosynthesis, surface-functionalization emerged in the last decade, grounded on the development of reliable methods for tailored synthesis, advanced characterization and theoretical modeling of metal NPs, altogether with the aim of transferring to the nanoscale the mechanistic knowledge acquired from molecular complexes. Metal NPs surface-functionalization modulates the energetics of key catalytic intermediates, introduces second coordination sphere effects, influences the catalyst-electrolyte interface, and determines the metal NPs surface coverage and, accordingly, the number of accessible active sites. In photoactivated systems, metal NPs surface-functionalization may play a key role in modulating the charge transfers and recombination processes between the light absorber and the active sites and in the light absorber itself. Thus, after a presentation of the most relevant synthetic methods to produce well-defined surface-functionalized metal NPs, a critical analysis of why the above effects are the cornerstone in enhancing their catalytic performance in the key processes of artificial photosynthesis, namely the oxygen evolution reaction, the hydrogen evolution reaction, and the CO2 reduction reaction, is given