Combining Physical galaxy models with radio observations to constrain the SFRs of high-z dusty star forming galaxies

We complement our previous analysis of a sample of z~1-2 luminous and ultra-luminous infrared galaxies ((U)LIRGs), by adding deep VLA radio observations at 1.4 GHz to a large data-set from the far-UV to the sub-mm, including Spitzer and Herschel data. Given the relatively small number of (U)LIRGs in our sample with high S/N radio data, and to extend our study to a different family of galaxies, we also include 6 well sampled near IR-selected BzK galaxies at z~1.5. From our analysis based on the radiative transfer spectral synthesis code GRASIL, we find that, while the IR luminosity may be a biased tracer of the star formation rate (SFR) depending on the age of stars dominating the dust heating, the inclusion of the radio flux offers significantly tighter constraints on SFR. Our predicted SFRs are in good agreement with the estimates based on rest-frame radio luminosity and the Bell (2003) calibration. The extensive spectro-photometric coverage of our sample allows us to set important constraints on the SF history of individual objects. For essentially all galaxies we find evidence for a rather continuous SFR and a peak epoch of SF preceding that of the observation by a few Gyrs. This seems to correspond to a formation redshift of z~5-6. We finally show that our physical analysis may affect the interpretation of the SFR-M* diagram, by possibly shifting, with respect to previous works, the position of the most dust obscured objects to higher M* and lower SFRs.Comment: 26 pages, 15 figures, 3 tables, accepted for publication in MNRAS on Dec. 4th, 201

AVALIAÇÃO DA MICROBIOTA DE ALFACE (Lactuca sativa)COMERCIALIZADA NO MUNICÍPIO DE ALEGRE-ES

As hortaliças são uma fonte importante de vitaminas, minerais e fibras, que são essenciais para o bom funcionamento do organismo, por isso cada vez mais cresce o seu consumo. A alface é uma das hortaliças mais consumidas no Brasil, principalmente na sua forma crua, entretanto nos últimos anos tem sido associada a surtos alimentares. Várias metodologias podem ser utilizadas para determinação de micro-organismos em alimentos. No entanto, é crescente a necessidade da utilização de métodos que proporcionem resultados mais rápidos. Dessa forma a técnica de reação em cadeia da polimerase (PCR) tem se mostrado uma ferramenta eficaz para tal finalidade. Este trabalho objetivou em avaliar a ocorrência de Salmonella spp. em alface (Lactuca sativa) do tipo crespa, comercializada no município de Alegre-ES. Para realização do estudo foram utilizadas 60 amostras de alface do tipo crespa e cultivo convencional comercializadas na feira livre e outros estabelecimentos da cidade. Foi realizada a determinação dos seguintes grupos microbianos nas amostras avaliadas: mesófilos aeróbios, fungos filamentos e leveduras, coliformes totais e termotolerantes. A determinação da ocorrência de Salmonella spp. ocorreu por meio das seguintes etapas: pré-enriquecimento, enriquecimento seletivo, plaqueamento seletivo-diferencial e para confirmação foi utilizada a técnica de PCR. Foram avaliados 11 estabelecimentos, incluindo a feira livre. As amostras analisadas apresentaram contagens médias de mesófilos aeróbios de 6,80 log UFC.g-1 e fungos filamentosos e leveduras de 4,07 log UFC.g-1. Foi constatado que 100 % das amostras apresentaram coliformes totais e, com relação à presença de coliformes termotolerantes, 58 % das amostras apresentaram valores < 3 NMP g-1, 30 % entre 4 e 21 NMP g-1, e 12 % entre 43 e 93 NMP g-1. Pela técnica de PCR, 21,66 % (n = 13) das 60 amostras de alface avaliadas foram consideradas positivas para Salmonella spp. As amostras positivas para Salmonella spp. foram provenientes de oito dos 11 estabelecimentos avaliados. A partir dos resultados obtidos ressalta-se a importância da adoção de medidas preventivas para reduzir a contaminação da alface in natura e demais hortaliças ao longo de toda cadeia produtiva, como uma forma de reduzir os riscos à saúde associados ao consumo deste alimento

Analyzing library collections with starfield visualizations

This paper presents a qualitative and formative study of the uses of a starfield-based visualization interface for analysis of library collections. The evaluation process has produced feedback that suggests ways to significantly improve starfield interfaces and the interaction process to improve their learnability and usability. The study also gave us clear indication of additional potential uses of starfield visualizations that can be exploited by further functionality and interface development. We report on resulting implications for the design and use of starfield visualizations that will impact their graphical interface features, their use for managing data quality and their potential for various forms of visual data mining. Although the current implementation and analysis focuses on the collection of a physical library, the most important contributions of our work will be in digital libraries, in which volume, complexity and dynamism of collections are increasing dramatically and tools are needed for visualization and analysis

Experiences with starfield visualizations for analysis of library collections

This paper presents a qualitative and formative study of the uses of a starfield-based visualization interface for analysis of library collections. The evaluation process has produced feedback that suggests ways to significantly improve starfield interfaces and the interaction process to improve their learnability and usability. The study also gave us clear indication of additional potential uses of starfield visualizations that can be exploited by further functionality and interface development. We report on resulting implications for the design and use of starfield visualizations that will impact their graphical interface features, their use for managing data quality and their potential for various forms of visual data mining. Although the current implementation and analysis focuses on the collection of a physical library, the most important contributions of our work will be in digital libraries, in which volume, complexity and dynamism of collections are increasing dramatically and tools are needed for visualization and analysis

Populações de plantas e adubação orgânica em solo degradado na cultura do amendoim

bitstream/CNPA/19705/1/BOLETIM51.pd

Solos da área do Programa Grande Carajás.

bitstream/item/55009/1/CPATU-DOC-110001.pdfAnexo mapa: Mapa esquemático de solos

Surface superconductivity in multilayered rhombohedral graphene: Supercurrent

The supercurrent for the surface superconductivity of a flat-band multilayered rhombohedral graphene is calculated. Despite the absence of dispersion of the excitation spectrum, the supercurrent is finite. The critical current is proportional to the zero-temperature superconducting gap, i.e., to the superconducting critical temperature and to the size of the flat band in the momentum space