The first INTEGRAL-OMC catalogue of optically variable sources

The Optical Monitoring Camera (OMC) onboard INTEGRAL provides photometry in the Johnson V-band. With an aperture of 50 mm and a field of view of 5deg x 5deg, OMC is able to detect optical sources brighter than V~18, from a previously selected list of potential targets of interest. After more than nine years of observations, the OMC database contains light curves for more than 70000 sources (with more than 50 photometric points each). The objectives of this work have been to characterize the potential variability of the objects monitored by OMC, to identify periodic sources and to compute their periods, taking advantage of the stability and long monitoring time of the OMC. To detect potential variability, we have performed a chi-squared test, finding 5263 variable sources out of an initial sample of 6071 objects with good photometric quality and more than 300 data points each. We have studied the periodicity of these sources using a method based on the phase dispersion minimization technique, optimized to handle light curves with very different shapes.In this first catalogue of variable sources observed by OMC, we provide for each object the median of the visual magnitude, the magnitude at maximum and minimum brightness in the light curve during the window of observations, the period, when found, as well as the complete intrinsic and period-folded light curves, together with some additional ancillary data.Comment: Accepted by Astronomy & Astrophysics; 13 pages, 16 figures. Figures' resolution has been degraded to fit astro-ph constraint

Chirality in Bare and Passivated Gold Nanoclusters

Chiral structures have been found as the lowest-energy isomers of bare (Au$_{28}$ and Au$_{55}) and thiol-passivated (Au$_{28}(SCH$_{3})$_{16}$and Au$_{38}(SCH_{3})_{24}) gold nanoclusters. The degree of chirality existing in the chiral clusters was calculated using the Hausdorff chirality measure. We found that the index of chirality is higher in the passivated clusters and decreases with the cluster size. These results are consistent with the observed chiroptical activity recently reported for glutahione-passivated gold nanoclusters, and provide theoretical support for the existence of chirality in these novel compounds.Comment: 5 pages, 1 figure. Submitted to PR

Método de Prospección y Caracterización de materias primas

Número de publicación: ES2341697 A1 (24.06.2010)También publicado como: ES2341697 B2 (26.04.2011)Número de Solicitud: Consulta de Expedientes OEPM (C.E.O.) P200803674(23.12.2008)Método de prospección y caracterización geológica de materias primas. El método objeto de la invención consiste en el uso de un sistema SIG para la gestión y utilización de datos obtenidos previamente almacenados en medios de almacenamiento de datos conformando bases de datos independientes que son fusionadas y cuyo resultado es trasferido al sistema SIG para representar las localizaciones y materias primas que se encuentran en dicha ubicación elegida o viceversa.Universidad de Almerí

Optical counterpart to Swift J0243.6+6124

Swift J0243.6+6124 was discovered during a giant X-ray outburst in October 2017. While there are numerous studies in the X-ray band, very little is known about the optical counterpart. We have performed an spectral and photometric analysis of the optical counterpart of this intriguing source. We find that the optical counterpart to Swift J0243.6+6124 is a V = 12.9, O9.5Ve star, located at a distance of $\sim5$ kpc. The optical extinction in the direction of the source is $A_V=3.6$ mag. The rotational velocity of the O-type star is 210 km s$^{-1}$. The long-term optical variability agrees with the growth and subsequent dissipation of the Be circumstellar disk after the giant X-ray outburst. The optical and X-ray luminosity are strongly correlated during the outburst, suggesting a common origin. We did not detect short-term periodic variability that could be associated with nonradial pulsations from the Be star photosphere.Comment: Wrong label in Fig 4 correcte

Stark Control of Electrons Across the Molecule-Semiconductor Interface

Controlling matter at the level of electrons using ultrafast laser sources represents an important challenge for science and technology. Recently we introduced a general laser control scheme (the Stark Control of Electrons at Interfaces or SCELI) based on the Stark effect that uses the subcycle structure of light to manipulate electron dynamics at semiconductor interfaces [{Phys. Rev. B \textbf{98}, 121305 (2018)}]. Here, we demonstrate that SCELI is also of general applicability in molecule-semiconductor interfaces. We do so by following the quantum dynamics induced by non-resonant few-cycle laser pulses of intermediate intensity (non-perturbative but non-ionizing) across model molecule-semiconductor interfaces of varying level alignments. We show that SCELI induces interfacial charge transfer regardless of the energy level alignment of the interface and even in situations where charge exchange is forbidden via resonant photoexcitation. We further show that the SCELI rate of charge transfer is faster than those offered by resonant photoexcitation routes as it is controlled by the subcycle structure of light. The results underscore the general applicability of SCELI to manipulate electron dynamics at interfaces on ultrafast timescales.Comment: 10 pages, 7 figure

Predictive modelling of magnesium concentration in grapevine petioles as a basis for liming recommendations in vineyard acid soils

Soil acidification is a natural process which can either be accelerated by the activity of plants, animals and humans, but can be controlled through appropriate soil management. The main aim of this work was to develop a predictive modelling of magnesium concentration in grapevine petioles for liming amendment recommendation in vineyard acid soils. One liming material, dolomite, has been added to the soil at three doses: 0.9, 1.8 and 2.7 t CaCO3 ha-1. Magnesium exchangeable content in soil surface and concentrations of this nutrient in petioles of leaf samples were investigated during three years. Exchangeable magnesium in soil tended to increase with increasing dolomite application rate. These increases were significant among all the doses and the control, except for the dose of 0.9. However, only between the highest dose and the control significant differences in magnesium concentration in petioles could be detected. In addition, one linear model has been proposed to make liming recommendations in vineyard acid soils based on petiole magnesium concentrations.

Frizzled-8 integrates Wnt-11 and transforming growth factor-β signaling in prostate cancer

Wnt-11 promotes cancer cell migration and invasion independently of β-catenin but the receptors involved remain unknown. Here, we provide evidence that FZD8 is a major Wnt-11 receptor in prostate cancer that integrates Wnt-11 and TGF-β signals to promote EMT. FZD8 mRNA is upregulated in multiple prostate cancer datasets and in metastatic cancer cell lines in vitro and in vivo. Analysis of patient samples reveals increased levels of FZD8 in cancer, correlating with Wnt-11. FZD8 co-localizes and co-immunoprecipitates with Wnt-11 and potentiates Wnt-11 activation of ATF2-dependent transcription. FZD8 silencing reduces prostate cancer cell migration, invasion, three-dimensional (3D) organotypic cell growth, expression of EMT-related genes, and TGF-β/Smad-dependent signaling. Mechanistically, FZD8 forms a TGF-β-regulated complex with TGF-β receptors that is mediated by the extracellular domains of FZD8 and TGFBR1. Targeting FZD8 may therefore inhibit aberrant activation of both Wnt and TGF-β signals in prostate cancer

Identification of novel bioactive peptides

Motivation: Targeting agents are the most commonly used strategies in therapeutics and diagnostic treatment.They can be classified in two main classes: chemicals and biologicals. Chemicals (farmaceutics and related) have been used for years, but nowadays biologicals experience an increasing demand because of their potentially higher specificity and affinity. Bioactive peptides from rational design can act as targeting agents that specifically interact with, and mostly inhibit, a biomolecule of interest (Seignauric et al., 2011).Methods: We have built a large library of peptides, and are screening for those that have biological activity, specially related to cell proliferation inhibition. The initial inconvenience is that small peptides cannot be expressed from single transcription unit as larger proteins, as they will be destroyed by cell proteases system. It is necessary to include the peptide library into a protein scaffold. We have designed a novel structure that includes the variable peptide sequence from the library between two mini-domains "EFLIVIKS" (one letter aminoacid code) able to form a noncovalent loop (Gururaja et al., 2010). In one of our constructs we have included a T7 promoter to allow conditional expression in bacteria. For its expression, we have designed two large nucleotide sequences (79 and 124 nucleotides, the large one includes the variable peptide sequence) that assemble by 20 complementary nucleotides in their 3' ends. By polymerization, both oligos strings are filled and form a two-chain structure, that will be inserted in a expression vector to obtain our peptide library. We transform bacteria (E. coli) and yeast (Schizosaccharomyces pombe) in order to identify those colonies excpressing the bioactive peptides that kill the cells or interrupt cell cycle

Cloning and expression of a Saccharomyces cerevisiae RNA-dependent RNA polymerase

RNA-dependent RNA polymerases (RdRp) are ubiquous enzimes  first described in RNA viruses and virus-like elements. In Saccharomyces cerevisiae this enzyme can be found, fused with capsid proteins, encoded by the L-A helper virus-like particle. Replication cycle of L-A is coupled to that of M satellite particle, which confers a killer phenotype to the yeast (Schmitt & Breinig, 2002). RdRp recognizes and replicates ssRNA from both L-A and M virus. RdRp recognizes a 3'-Terminal Recognition Element (3'TRE), a small stem-loop 5 bases from the 3' end (Ribas, Fujimuras, & Wickner, 1994), which can be used as an effective tool for primerless replication of RNA molecules. To gain further insight on the virus-like particle replication mechanism and to evaluate its possible biotechnological application, the present project is focused on cloning the RdRp coding sequence in several different expression vectors and expressing the protein using different Escherichia coli strains as hosts. Once RdRp is efficiently expressed, we will proceed to purify it by affinity chromatography and test the protein activity by replicating full length viral RNA´s and other RNA sequences with or without the 3'TRE sequence. In our communication we will present our advances in cloning, expression, purification and activity of the yeast polymeras