The AGN Population in Nearby Galaxies

In order to determine the incidence of black hole accretion-driven nuclear activity in nearby galaxies, we have compiled radio data for the LINERs, composite LINER,/Hn and Seyfert galaxies from a complete magnitude-limited sample of bright nearby galaxies (Palomar sample). Our results show an overall radio detection rate of 54% (22% of all bright nearby galaxies) and we estimate that at least ~50% (~20% of all bright nearby galaxies) are true AGN. By comparing the radio luminosity function of the LINERs, composite LINER/Hll and Seyferts galaxies in the Palomar sample with those of selected moderate-redshift AGN, we fhd that our sources naturally extend the radio luminosity function of powerful AGN down to powers of about 10 times that of Sgr A*

Anti-atherogenic properties associated with the antioxidant activity from the hydrophilic extracts of Halimeda incrassata (Chlorophyta, Bryopsidales)

Seaweeds are a source of natural antioxidants having potential application in oxidative stress and associated diseases. In this work, anti-atherogenic properties associated with the antioxidant activity from the hydrophilic extracts of Halimeda incrassata were studied. The phenolic content assessed inthe aqueous extract and fraction phenolic acids (FPA) was 0.13 ± 0.05 and 0.47 ± 0.09 mg of gallic acid equivalents (GAE)/g dry seaweed, respectively. In DPPH?, radical scavenging assay fractions exhibited a dependent concentration. The seaweeds extract inhibited the desoxirribose oxidation in the presenceor absence of EDTA (IC50 = 1.91± 0.09 mg/mL) (IC50 = 2.95 ± 0.01 mg/mL). In vivo antioxidant properties of FPA-H.incrassata were investigated in rats with a CCl4-induced liver injury. Pre-treatment with H.incrassata led to approximately 50% reductions in liver TBARS levels. The treatment with H. incrassataFPA also increased the activity of the CAT enzyme, which in turn resulted in an enhanced antioxidantdefense. The expression of Catalase by PCR-RT technique demonstrated a higher gene expression when compared with that which was observed in the CCl 4-treated group. Antiatherogenic properties were studied in the inhibition of lipoprotein oxidation mediated by Cu2+ or HRP/H2O2, free radicalscavenging, and metal ion chelation, and it was dose dependent with a higher concentration needed for the aqueous extract than for the FPA fraction. Antioxidant activity was also improved in macrophages as evaluated in the cell supernatant (by TBARS formation); and by luminol enhanced chemiluminescence after cell activation with zymosan; and a degree of cell lipoperoxidation wasdecreased by the Halimeda incrassata extract. The results of this work add to the antioxidant potential of the seaweed for its application in oxidative stress associated conditions.Fil: Vidal-Novoa, Alexis. Universidad de la Habana. Facultad de Biología; CubaFil: Costa-Mugica, Ariadna. Universidad de la Habana. Facultad de Biología; CubaFil: Zulueta Díaz, Yenisleidy de Las Mercedes. Universidad de la Habana. Facultad de Biología; Cuba. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Diaz-Gutierrez, Daylín. Universidad de la Habana. Facultad de Biología; CubaFil: de Oliveira e Silva, Ana, Mara. Universidade de Sao Paulo; BrasilFil: Vazquez, Ana María. Center For Molecular Inmunology; CubaFil: Claudina, Zaldívar-Munoz. Universidad de la Habana. Facultad de Biología; CubaFil: Dalva, Assuncao Portari de Mancini. Institute Butantan Sao Paulo; BrasilFil: Mancini-Filho, Jorge. Universidade de Sao Paulo; Brasi

Distribuição longitudinal de Chironomidae (Diptera) abaixo de uma barragem em um rio neotropical

The damming of a river causes dangerous consequences on structure of the environment downstream of the dam, modifying the sediment composition, which impose major adjustments in longitudinal distribution of benthic community. The construction of Engenheiro Sérgio Motta Dam in the Upper Paraná River has caused impacts on the aquatic communities, which are not yet fully known. This work aimed to provide more information about the effects of this impoundment on the structure of Chironomidae larvae assemblage. The analysis of data of physical and chemical variables in relation to biological data of 8 longitudinal sections in the Upper Paraná River showed that composition of Chironomidae larvae of stations near Engenheiro Sérgio Motta Dam differed of the other stations (farther of the Dam) The predominance of coarse sediments at stations upstream and finer sediments further downstream affected the choice of habitat by different morphotypes of Chironomidae and it caused a change in the structure of this assemblage in the longitudinal stretch.O barramento de um rio pode causar graves consequências sobre a natureza do ambiente, abaixo da barragem, modificando a composição do sedimento, as quais impõem importantes ajustes da distribuição longitudinal das comunidades bentônicas. A construção da Usina Hidrelétrica Engenheiro Sérgio Motta no alto rio Paraná, tem causado impactos em várias comunidades aquáticas, que ainda não são totalmente conhecidos. Este trabalho objetivou fornecer mais informações sobre os efeitos desse represamento na assembleia de Chironomidae. A análise das variáveis físicas e químicas em relação aos dados biológicos de oito transectos longitudinais no alto rio Paraná revelou que a composição das larvas de Chironomidae das estações mais próximas à barragem da Usina Engenheiro Sérgio Motta diferiu das demais (estações mais distantes). A predominância de sedimentos mais grosseiros nas estações a montante e sedimentos mais finos mais a jusante afetou a escolha de habitat pelos diferentes morfotipos de Chironomidae, que levou a alteração na estrutura desta assembleia ao longo do trecho amostrado.Fil: Pinha, G. D.. Universidade Estadual de Maringá. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais; Brasil.;Fil: Aviz, D.. Universidade Federal Do Pará; Brasil.;Fil: Lopes Filho, D. R.. Universidade Estadual de Maringá. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais; Brasil.;Fil: Petsch, D. K.. Universidade Estadual de Maringá. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais; Brasil.;Fil: Marchese Garello, Mercedes Rosa. Consejo Nacional de Investigaciones científicas y Técnicas. Centro Científico Tecnológico CONICET- Santa Fe. Instituto Nacional de Limnologia (i); Argentina;Fil: Takeda, A. M.. Universidade Estadual de Maringá; Brasil.

A review of the quantification and classification of pigmented skin lesions: from dedicated to hand-held devices

In recent years, the incidence of skin cancer caseshas risen, worldwide, mainly due to the prolonged exposure toharmful ultraviolet radiation. Concurrently, the computerassistedmedical diagnosis of skin cancer has undergone majoradvances, through an improvement in the instrument and detectiontechnology, and the development of algorithms to processthe information. Moreover, because there has been anincreased need to store medical data, for monitoring, comparativeand assisted-learning purposes, algorithms for data processingand storage have also become more efficient in handlingthe increase of data. In addition, the potential use ofcommon mobile devices to register high-resolution imagesof skin lesions has also fueled the need to create real-timeprocessing algorithms that may provide a likelihood for thedevelopment of malignancy. This last possibility allows evennon-specialists to monitor and follow-up suspected skin cancercases. In this review, we present the major steps in the preprocessing,processing and post-processing of skin lesion images,with a particular emphasis on the quantification andclassification of pigmented skin lesions. We further reviewand outline the future challenges for the creation of minimum-feature,automated and real-time algorithms for the detectionof skin cancer from images acquired via common mobiledevices

Phase Referencing in Optical Interferometry

One of the aims of next generation optical interferometric instrumentation is to be able to make use of information contained in the visibility phase to construct high dynamic range images. Radio and optical interferometry are at the two extremes of phase corruption by the atmosphere. While in radio it is possible to obtain calibrated phases for the science objects, in the optical this is currently not possible. Instead, optical interferometry has relied on closure phase techniques to produce images. Such techniques allow only to achieve modest dynamic ranges. However, with high contrast objects, for faint targets or when structure detail is needed, phase referencing techniques as used in radio interferometry, should theoretically achieve higher dynamic ranges for the same number of telescopes. Our approach is not to provide evidence either for or against the hypothesis that phase referenced imaging gives better dynamic range than closure phase imaging. Instead we wish to explore the potential of this technique for future optical interferometry and also because image reconstruction in the optical using phase referencing techniques has only been performed with limited success. We have generated simulated, noisy, complex visibility data, analogous to the signal produced in radio interferometers, using the VLTI as a template. We proceeded with image reconstruction using the radio image reconstruction algorithms contained in AIPS IMAGR (CLEAN algorithm). Our results show that image reconstruction is successful in most of our science cases, yielding images with a 4 milliarcsecond resolution in K band. (abridged)Comment: 11 pages, 36 figure

Ecological research in the Large Scale Biosphere Atmosphere Experiment in Amazonia: A discussion of early results

The Large-scale Biosphere–Atmosphere Experiment in Amazonia (LBA) is a multinational, interdisciplinary research program led by Brazil. Ecological studies in LBA focus on how tropical forest conversion, regrowth, and selective logging influence carbon storage, nutrient dynamics, trace gas fluxes, and the prospect for sustainable land use in the Amazon region. Early results from ecological studies within LBA emphasize the variability within the vast Amazon region and the profound effects that land-use and land-cover changes are having on that landscape. The predominant land cover of the Amazon region is evergreen forest; nonetheless, LBA studies have observed strong seasonal patterns in gross primary production, ecosystem respiration, and net ecosystem exchange, as well as phenology and tree growth. The seasonal patterns vary spatially and interannually and evidence suggests that these patterns are driven not only by variations in weather but also by innate biological rhythms of the forest species. Rapid rates of deforestation have marked the forests of the Amazon region over the past three decades. Evidence from ground-based surveys and remote sensing show that substantial areas of forest are being degraded by logging activities and through the collapse of forest edges. Because forest edges and logged forests are susceptible to fire, positive feedback cycles of forest degradation may be initiated by land-use-change events. LBA studies indicate that cleared lands in the Amazon, once released from cultivation or pasture usage, regenerate biomass rapidly. However, the pace of biomass accumulation is dependent upon past land use and the depletion of nutrients by unsustainable land-management practices. The challenge for ongoing research within LBA is to integrate the recognition of diverse patterns and processes into general models for prediction of regional ecosystem function