Integrated spectra extraction based on signal-to-noise optimization using Integral Field Spectroscopy

We propose and explore the potential of a method to extract high signal-to-noise (S/N) integrated spectra related to physical and/or morphological regions on a 2-dimensional field using Integral Field Spectroscopy (IFS) observations by employing an optimization procedure based on either continuum (stellar) or line (nebular) emission features. The optimization method is applied to a set of IFS VLT-VIMOS observations of (U)LIRG galaxies, describing the advantages of the optimization by comparing the results with a fixed-aperture, single spectrum case, and by implementing some statistical tests. We demonstrate that the S/N of the IFS optimized integrated spectra is significantly enhanced when compared with the single aperture unprocessed case. We provide an iterative user-friendly and versatile IDL algorithm that allows the user to spatially integrate spectra following more standard procedures. This is made available to the community as part of the PINGSoft IFS software package.Comment: Accepted for publication in Astronomy & Astrophysics, 12 pages, 7 figure

Census of HII regions in NGC 6754 derived with MUSE: Constraints on the metal mixing scale

We present a study of the HII regions in the galaxy NGC 6754 from a two pointing mosaic comprising 197,637 individual spectra, using Integral Field Spectrocopy (IFS) recently acquired with the MUSE instrument during its Science Verification program. The data cover the entire galaxy out to ~2 effective radii (re ), sampling its morphological structures with unprecedented spatial resolution for a wide-field IFU. A complete census of the H ii regions limited by the atmospheric seeing conditions was derived, comprising 396 individual ionized sources. This is one of the largest and most complete catalogue of H ii regions with spectroscopic information in a single galaxy. We use this catalogue to derive the radial abundance gradient in this SBb galaxy, finding a negative gradient with a slope consistent with the characteristic value for disk galaxies recently reported. The large number of H ii regions allow us to estimate the typical mixing scale-length (rmix ~0.4 re ), which sets strong constraints on the proposed mechanisms for metal mixing in disk galaxies, like radial movements associated with bars and spiral arms, when comparing with simulations. We found evidence for an azimuthal variation of the oxygen abundance, that may be related with the radial migration. These results illustrate the unique capabilities of MUSE for the study of the enrichment mechanisms in Local Universe galaxies.Comment: 13 pages, 7 Figurs, accepted for publishing in A&

Ga-induced atom wire formation and passivation of stepped Si(112)

We present an in-depth analysis of the atomic and electronic structure of the quasi one-dimensional (1D) surface reconstruction of Ga on Si(112) based on Scanning Tunneling Microscopy and Spectroscopy (STM and STS), Rutherford Backscattering Spectrometry (RBS) and Density Functional Theory (DFT) calculations. A new structural model of the Si(112)6 x 1-Ga surface is inferred. It consists of Ga zig-zag chains that are intersected by quasi-periodic vacancy lines or misfit dislocations. The experimentally observed meandering of the vacancy lines is caused by the co-existence of competing 6 x 1 and 5 x 1 unit cells and by the orientational disorder of symmetry breaking Si-Ga dimers inside the vacancy lines. The Ga atoms are fully coordinated, and the surface is chemically passivated. STS data reveal a semiconducting surface and show excellent agreement with calculated Local Density of States (LDOS) and STS curves. The energy gain obtained by fully passivating the surface calls the idea of step-edge decoration as a viable growth method toward 1D metallic structures into question.Comment: Submitted, 13 pages, accepted in Phys. Rev. B, notational change in Fig.

Immersion and invariance stabilization of nonlinear systems: A horizontal contraction approach

The main objective of this paper is to propose an alternative procedure to carry out one of the key steps of immersion and invariance stabilising controller design. Namely, the one that ensures attractivity of the manifold whose internal dynamics contains a copy of the desired system behaviour. Towards this end we invoke contraction theory principles and ensure the attractivity of the manifold rendering it horizontally contractive. The main advantage of adopting this alternative approach is to make more systematic the last step of the design with more explicit degrees of freedom to accomplish the task. The classical case of systems in feedback form is used to illustrate the proposed controller design.This work is partially supported by National Basic Research Program of China (973 Program 2013CB035406) ; National Natural Science Foundation of China (NSFC: 61134007 and 61320106009).This is the author accepted manuscript. The final version is available from IEEE via http://dx.doi.org/10.1109/CDC.2015.740268

Integral Field Spectroscopy based H\alpha\ sizes of local Luminous and Ultraluminous Infrared Galaxies. A Direct Comparison with high-z Massive Star Forming Galaxies

Aims. We study the analogy between local U/LIRGs and high-z massive SFGs by comparing basic H{\alpha} structural characteristics, such as size, and luminosity (and SFR) surface density, in an homogeneous way (i.e. same tracer and size definition, similar physical scales). Methods. We use Integral Field Spectroscopy based H{\alpha} emission maps for a representative sample of 54 local U/LIRGs (66 galaxies). From this initial sample we select 26 objects with H{\alpha} luminosities (L(H{\alpha})) similar to those of massive (i.e. M\ast \sim 10^10 M\odot or larger) SFGs at z \sim 2, and observed on similar physical scales. Results. The sizes of the H{\alpha} emitting region in the sample of local U/LIRGs span a large range, with r1/2(H{\alpha}) from 0.2 to 7 kpc. However, about 2/3 of local U/LIRGs with Lir > 10^11.4 L\odot have compact H{\alpha} emission (i.e. r1/2 < 2 kpc). The comparison sample of local U/LIRGs also shows a higher fraction (59%) of objects with compact H{\alpha} emission than the high-z sample (25%). This gives further support to the idea that for this luminosity range the size of the star forming region is a distinctive factor between local and distant galaxies of similar SF rates. However, when using H{\alpha} as a tracer for both local and high-z samples, the differences are smaller than the ones recently reported using a variety of other tracers. Despite of the higher fraction of galaxies with compact H{\alpha} emission, a sizable group (\sim 1/3) of local U/LIRGs are large (i.e. r1/2 > 2 kpc). These are systems showing pre-coalescence merger activity and they are indistinguishable from the massive high-z SFGs galaxies in terms of their H{\alpha} sizes, and luminosity and SFR surface densities.Comment: Accepted for publication in A&A. (!5 pages, 7 figures, 2 tables

Proteolytic Cleavage of a Spectrin-Related Protein by Calcium-Dependent Protease in Neurospora crassa

To investigate the functional significance of a cytoskeletal spectrin-like protein, we studied its localization pattern in Neurospora crassa and sought the answer to whether it is a substrate for another apically localized protein, the calcium-dependent protease (CDP II). Immunoblots of crude extracts from exponentially growing mycelia, separated by one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis using antichicken α/β-spectrin antibodies, revealed a single band of approximately relative mass (Mr) 100 kDa with an isoeletric point (pI) in the range of 6.5 to 7.0. Despite rigorous efforts, we could not confirm the presence of an Mr 240- to 220-kDa spectrin-like protein in N. crassa. The immunofluorescence- and immunogold-labeling Mr 100-kDa protein showed its predominance along the plasma membrane of the conidia during the swelling phase of germination. In contrast, in the germ tubes and the growing hyphae, the localization was polarized and concentrated mainly in the apical region. The in vitro proteolysis experiments showed that indeed this protein is a preferred substrate of CDP II which is, as mentioned previously, also localized in the apical regions of the hyphae. These results indicate a putative functional relationship between these two proteins (spectrin-like protein and CDP II) in the dynamics of tip growt

Análise emergética dos sistemas de pesca no pantanal

Os sistemas de pesca (profissional-artesanal, subsistência e amadora) constituem atividades econômicas muito importantes no Pantanal. Por meio da análise emergética será avaliado seu desempenho. As primeiras análises revelam que a pesca profissional artesanal utiliza amplamente os recursos naturais, com pouca entrada de recursos econômicos externos, e o peixe é vendido para turistas e comunidade local; os fluxos são internos ao ecossistema e as externalidades são mínimas. A pesca de subsistência mostra ser auto-suficiente. A pesca amadora, por outro lado, requer maior infra-estrutura, as articulações com a economia local são limitadas e gera vários tipos de externalidades negativas. In the “Pantanal”, a very big Brazilian wetland, fishery is an important economic activity that is carried out under three modalities: professional-artisanal, subsistence and touristic. Their ecological and thermodynamic performance will be studied using the emergy methodology. As first stage of this analysis, it was realized an information recovery in order to prepare the systems diagrams. The diagrams revealed the dependence of each one of fishery systems with local and external resources. Subsistence fishery is sustainable but doesn’t have product for sale. Professional-artisanal fishery interacts with different markets and uses a small quantity of external inputs. Touristic fishery depends on infra-structure investments and do not interact in adequate form with local economy

Vertebrate fauna at the Allosaurus fossil-site of Andrés (Upper Jurassic), Pombal, Portugal

An overview of the faunistic diversity of the Andres fossil-site from the Portuguese Upper Jurassic is presented. This work provides a preliminary approach on the vertebrate fauna known at present. Although this quarry is known since the 1990’s, due to the description on the first robust evidence of a member of the neotetanuran genus Allosaurus outside North America, the results presented here are mainly derived from the analysis of the elements found during the second and third field seasons in 2005. At the moment, among the material collected from Andrés it was identified remains that represent a diverse vertebrate fauna, including fishes, sphenodonts, crocodrylomorphs, pterosaurs, and at least, seven distinct dinosaur forms. The recovery of this diverse and abundant osteological collection from one unique fossil-site is noteworthy for the Upper Jurassic Portuguese record, and only comparable with those from the Guimarota coalmine. Due to these two features plus the good preservation of the fossils, the Andres quarry may be a site of reference for the analysis of vertebrate ecosystems from the Portuguese Upper Jurassic. Dinosaur elements are the most abundant fossils, and among them it is particulary common the presence of remains identified as Allosaurus. These new evidences allow testing the previus phylogenetical hypothesys ascribing the firsts theropod remains from Andrés to A. fragilis, a species described in synchronic levels of the North American Morrison Formation. The similarity between the Allosaurus remains collected in Andres and some specimens from the Morrison Formation seems to point the existence of a genetic flow between some continental vertebrates on both sides of the proto-north Atlantic during the Upper Jurassic. Favourable tectonic conditions for the occurrence of punctual contacts between the two continents is, at present, the best scenario for explain this situation.Se presenta un analisis de la diversidad faunistica del yacimiento de Andrés en el Jurasico Superior de la Cuenca Lusitanica. El presente trabajo pretende establecer un análisis preliminar de la fauna de vertebrados identificada en el yacimiento hasta la fecha. Aunque conocido desde la decada de 1990, debido a la descripcion de la primera evidencia robusta de un neotetanuro del genero Allosaurus fuera de Norteamerica, los resultados presentados derivan principalmente del analisis de elementos encontrados durante la segunda y tercera campanas de excavacion en 2005. Hasta el momento han sido identificados entre el material recogido en Andrés, representantes de diversos taxones de vertebrados que incluyen que incluyen peces, esfenodontos, crocodilomorfos, pterosaurios y, al menos, siete formas distintas de dinosaurios. La presencia de esta diversidad y abundancia de restos osteologicos en el mismo yacimiento representa una situacion unica en el registro del Jurasico Superior portugues, tan solo comparable a la del yacimiento clasico de la mina de carbon de Guimarota. Atendiendo a estas dos caracteristicas y a la buena preservacion de los fosiles, el yacimiento de Andres puede ser considerado como una localidad de referencia para el estudio de los ecosistemas con vertebrados del Jurasico Superior portugues. Los restos de dinosaurios son los fosiles mas abundantes y, entre ellos, son particularmente comunes los asignables a Allosaurus. Estas nuevas evidencias proporcionan a A. fragilis, una especie descrita en niveles sincronicos de la Formacion Morrison en Norteamerica. La similitud entre los restos de Allosaurus recogidos en Andres y algunos de los ejemplares de la Formacion Morrison, sugiere la existencia de un flujo genético entre algunos vertebrados continentales de ambos lados del proto-Atlántico norte durante el Jurásico Superior. La existencia de condiciones tectonicas favorables para la existencia de contactos puntuales entre los dos continentes es actualmente el mejor escenario para explicar esta situacion