Segmentation of optical remote sensing images for detecting homogeneous regions in space and time.

With the amount of multitemporal and multiresolution images growing exponentially, the number of image segmentation applications is recently increasing and, simultaneously, new challenges arise. Hence, there is a need to explore new segmentation concepts and techniques that make use of the temporal dimension. This paper describes a spatio-temporal segmentation that adapts the traditional region growing technique to detect homogeneous regions in space and time in optical remote sensing images. Tests were conducted by considering the Dynamic Time Warping measure as the homogeneity criterion. Study cases on high temporal resolution for sequences of MODIS and Landsat-8 OLI vegetation indices products provided satisfactory outputs and demonstrated the potential of the spatio-temporal segmentation method.Também publicado na Revista Brasileira de Cartografia, v. 70, n. 5, p. 1779-1801, 2018. Special Issue XIX Brazilian Syposium on GeoInformatics, 2018. DOI: 10.14393/rbcv70n5-45227

The blp locus of Streptococcus pneumoniae plays a limited role in the selection of which strains can co-colonize the human nasopharynx.

Nasopharyngeal colonization is important for Streptococcus pneumoniae evolution, providing the opportunity for horizontal gene transfer when multiple strains co-occur. Although colonization with more than one strain of pneumococcus is common, the factors that influence the ability of strains to co-exist are not known. A highly variable blp (bacteriocin-like peptide) locus has been identified in all sequenced strains of S. pneumoniae This locus controls the regulation and secretion of bacteriocins, small peptides that target other bacteria. In this study, we analyzed a series of co-colonizing isolates to evaluate the impact of the blp locus on human colonization to determine whether competitive phenotypes of bacteriocin secretion restrict co-colonization.We identified a collection of 135 nasopharyngeal samples with two or more strains totaling 285 isolates. The blp locus of all strains was characterized genetically with regards to pheromone type, bacteriocin/immunity content and potential for locus functionality. Inhibitory phenotypes of bacteriocin secretion and locus activity were assessed through overlay assays. Isolates from single colonization (n=298) were characterized for comparison.Co-colonizing strains had a high diversity of blp cassettes; approximately one third displayed an inhibitory phenotype in vitro Despite in vitro evidence of competition, pneumococci co-colonized individuals independently of their blp pheromone type (p=0.577), bacteriocin/immunity content, blp locus activity (p=0.798) and inhibitory phenotype (p=0.716). In addition, no significant differences were observed when single and co-colonizing strains were compared.Despite clear evidence of blp-mediated competition in experimental models, our study suggests that the blp locus plays a limited role in restricting pneumococcal co-colonization in humans. IMPORTANCE: Nasopharyngeal colonization with Streptococcus pneumoniae (pneumococcus) is important for pneumococcal evolution as it represents the major site for horizontal gene transfer when multiple strains co-occur, a phenomenon known as co-colonization. Understanding how pneumococcal strains interact within the competitive environment of the nasopharynx is of chief importance in the context of pneumococcal ecology. In this study we used an unbiased collection of naturally co-occurring pneumococcal strains and showed that a biological process frequently used by bacteria for competition - bacteriocin production - is not decisive in the co-existence of pneumococci in the host, contrary to what has been shown in experimental models

The Geometry of Mass Outflows and Fueling Flows in the Seyfert 2 Galaxy Mrk 3

We present a study of the resolved emission-line regions and an inner dust/gas disk in the Seyfert 2 galaxy Mrk 3, based on Hubble Space Telescope observations. We show that the extended narrow-line region (ENLR), spanning ~4 kpc, is defined by the intersection of the ionizing bicone of radiation from the AGN and the inner disk, which is not coplanar with the large-scale stellar disk. This intersection leads to different position and opening angles of the ENLR compared to the narrow-line region (NLR). A number of emission-line arcs in the ENLR appear to be continuations of dust lanes in the disk, supporting this geometry. The NLR, which consists of outflowing emission-line knots spanning the central ~650 pc, is in the shape of a backwards S. This shape may arise from rotation of the gas, or it may trace the original fueling flow close to the nucleus that was ionized after the AGN turned on.Comment: 22 page, 7 figures, accepted for publication in the Astronomical Journa

Organização da informação de solos do Brasil: banco de dados de solos e Geoportal com acesso a mapas digitais via internet.

Neste trabalho será apresentado o sistema de gestão da informação científica sobre os solos brasileiros desenvolvido pela Embrapa Solos. Esta iniciativa visou minimizar as dificuldades de acesso ao acervo de mapas digitais produzidos pela Embrapa Solos e às informações advindas dos levantamentos de solos (dados morfológicos e analíticos). Neste sentido, foi proposto como solução, respectivamente: (i) o desenvolvimento de um GEOPORTAL com acesso a uma Mapoteca Digital; (ii) o desenvolvimento de um Sistema de Informação de Solos com acesso a um Banco de Dados de Solos, desenvolvido em parceria com a Embrapa Informática Agropecuária. Com quarenta anos dedicados a estudar os solos do Brasil, a Embrapa Solos é reconhecida como o centro de referência da temática solos em nosso país. Durante este tempo tem gerado, juntamente com outras instituições de pesquisa, uma grande quantidade de dados oriundos, sobretudo, dos levantamentos pedológicos. É, portanto, de grande importância que estas informações sejam organizadas em um sistema de gestão de mapas, dados e informação de solos de maneira a permitir a toda à sociedade brasileira o acesso a este acervo

The periodic Anderson model from the atomic limit and FeSi

The exact Green's functions of the periodic Anderson model for $U\to \infty$ are formally expressed within the cumulant expansion in terms of an effective cumulant. Here we resort to a calculation in which this quantity is approximated by the value it takes for the exactly soluble atomic limit of the same model. In the Kondo region a spectral density is obtained that shows near the Fermi surface a structure with the properties of the Kondo peak. Approximate expressions are obtained for the static conductivity $$ and magnetic susceptibility $\chi (T)$ of the PAM, and they are employed to fit the experimental values of FeSi, a compound that behaves like a Kondo insulator with both quantities vanishing rapidly for $T\to 0$. Assuming that the system is in the intermediate valence region, it was possible to find good agreement between theory and experiment for these two properties by employing the same set of parameters. It is shown that in the present model the hybridization is responsible for the relaxation mechanism of the conduction electrons.Comment: 26 pages and 8 figure

Contribuição da adubação verde na produção orgânica de olerícolas.

Existe demanda crescente da sociedade por sistemas de produção eficientes e competitivos, capazes de garantir a auto-sustentabilidade destes em consonância com o meio ambiente. Neste contexto está inserido o sistema orgânico de produção. Qualquer fito massa pode ser utilizada como adubo verde, inclusive a vegetação espontânea. Como há escassez de informações sobre a adubação verde com leguminosas na região Central de Minas Gerais, este trabalho foi proposto para avaliar as produções de matéria seca e de minerais de leguminosas cultivadas como adubos verdes em pré-plantio de olerícolas. O experimento foi instalado em dezembro de 2004, na EPAMIG, Prudente de Morais, MG. O delineamento experimental adotado foi o de blocos ao acaso com quatro repetições. As parcelas foram formadas pelos adubos verdes: Stizolobium aterrinus, Crotalaria juncea, Cajanus cajan e vegetação espontânea. Os resultados mostraram que na região Central de Minas Gerais, a quantidade de fitomassa produzida pela vegetação espontânea foi inferior à quantidade mínima sugerida para adubação verde e que a fitomassa da adubação verde com leguminosas é mais rica em nitrogênio, cálcio e magnésio quando comparada com a da vegetação espontânea

Comparative antibacterial potential of selected aldehyde-based biocides and surfactants against planktonic Pseudomonas fluorescens

The antimicrobial efficacy of two aldehydebased biocides (glutaraldehyde, GTA, and orthophthalaldehyde, OPA) and two surfactants (cetyltrimethyl ammonium bromide, CTAB, and sodium dodecyl sulphate, SDS) was tested against planktonic Pseudomonas fluorescens. The antimicrobial effects were evaluated by respiratory activity as a measure of the oxygen uptake rate, adenosine triphosphate (ATP) release, outer membrane proteins (OMP) expression and cellular colour changes. The results were compared with the bacterial characteristics without chemical treatment. Tests in the presence of bovine serum albumin (BSA), in order to mimic a disinfection process in the real situation under dirty conditions, were performed according to the European Standard EN-1276. P. fluorescens was completely inactivated with OPA (minimum bactericidal concentration, MBC = 0.5 mM) and CTAB (MBC = 5 mM) and was resistant to GTA and SDS. Only CTAB promoted cellular disruption and consequent ATP release. The antimicrobial action of the chemicals tested was significantly reduced when BSA was introduced into the bacterial cultures, increasing markedly the MBC values. Additionally, the presence of BSA acted as a disruption protective agent when CTAB was applied and stimulated the bacterial respiratory activity when lower concentrations of SDS were tested. The OMP of the bacterial cells was affected by the application of both surfactants. OMP expression remained unaltered after biocide treatment. Bacterial colour change was noticed after treatment with biocides and surfactants. In summary, P. fluorescens was extremely resistant to GTA and SDS, with antimicrobial action being quenched markedly by the reaction with BSA.Instituto de Biotecnologia e Química Fina (IBQF).Fundação para a Ciência e a Tecnologia (FCT) - (Project CHEMBIO - POCI/BIO/61872/2004

Zoneamento de risco climático para a cultura do milho no sertão do Estado de Pernambuco.

Trabalho publicado também em Resumos do CONGRESSO BRASILEIRO DE AGROMETEOROLOGIA, 14., 2005, Campinas. p. 92