274 research outputs found

    Caracterização morfológica da plataforma da ilha do Faial

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    A plataforma insular do Faial foi cartografada com recurso a um vasto conjunto de dados geofísicos e geológicos. A análise da morfologia da plataforma permitiu perceber quais os factores que mais contribuiram para a sua evolução

    Taxonomic review of selected invertebrate groups collected during the Campaigns of the Prince Albert I of Monaco in the Azorean waters.

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    In the late 19th and early 20th centuries Prince Albert I of Monaco promoted 13 cruises that sampled the Azorean waters. During those cruises a total of 2624 nominal marine species were reported in the area. This work assembles the biological data provided by these expeditions to the Azores in a geo-referenced database. Faunal lists for seven invertebrate groups (Echiura, Sipuncula, Cephalopoda, Annelida, Brachiopoda, Chaetognatha and Echinodermata) are compiled. The checklist includes 331 nominal species, of which 310 are valid names: 1 echiurid; 11 sipunculids; 32 cephalopods; 130 annelids; 4 brachiopods; 14 chaetognaths; and 118 echinoderms. Eighteen percent are synonyms, 29% of the species were allocated to a different genus, 2.8% were misspellings and corrections due to gender or concordance rules, 0.8% were specific epithets allocated to sub-specific level or vice-versa, the rest were validated directly (without any modification in their nomenclature)

    Notes on fauna associated with an opportunistic artificial reef near cold-water corals

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    This short communication provides a sporadic insight on the importance of a hard three-dimensional structure for deepwater fish near CWC. Fish size and behaviour inside the structure and in the surrounding area are described. Additionally, a list of biofouling macroorganisms found on the structure after one year of deployment is presented

    Cytotoxicity of spermine oxidation products to multidrug resistant melanoma M14 ADR2 cells: Sensitization by the MDL 72527 lysosomotropic compound

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    It has been confirmed that multidrug resistant (MDR) human melanoma cells are more sensitive than their wild-type counterparts to H(2)O(2) and aldehydes, the products of bovine serum amine oxidase (BSAO)-catalyzed oxidation of spermine. The metabolites formed by BSAO and spermine are more toxic than exogenous H(2)O(2) and acrolein, even thou-h their concentration is lower during the initial phase of incubation due to their more gradual release than the exogenous products. Both wild-type and MDR cells, after pre-treatment with MDL 72527, an inactivator of polyamine oxidase and a lysosomotropic compound, show to be sensitized to subsequent exposure to BSAO/spermine. Evidence of ultrastructural aberrations and acridine orange release from lysosomes is presented in this work that is in favor of the permeabilization of the lysosomal membrane as the major cause of sensitization by MDL 72527. Owing to its lysosomotropic effect, pre-treatment with MDL 72527 amplifies the ability of the metabolites formed from spermine by oxidative deamination to induce cell death. Since it is conceivable that combined treatment with a lysosomotropic compound and BSAO/spermine would be effective against tumor cells, it is of interest to search for such novel compounds, which might be promising for application in a therapeutic setting

    New occurrences of Corallium spp. (Octocorallia, Coralliidae) in the Central Northeast Atlantic

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    Corallium niobe Bayer, 1964 and Corallium tricolor (Johnson, 1899) are reported as new records from the central Northeast Atlantic. C. niobe was caught in the Azores and C. tricolor on the slope of the Irving Seamount (South Azores Seamounts). The presence of Corallium johnsoni Gray, 1860 in Azorean waters is confirmed. The sub-tropical Macaronesian islands and seamounts appear to be an important hot-spot for Corallium spp. Most colonies have been collected on seamounts and island slopes around Madeira, Canaries, Azores and the Cape Verde archipelagos. In the Azores most of these corals live below the normal depth of commercial fishing operations and are unlikely to be severely impacted by this activity

    Anticancer drugs and hyperthermia enhance cytotoxicity induced by polyamine enzymatic oxidation products

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    A correlation between regulation of cell proliferation and polyamine metabolism is described. The latter can enter protein synthesis through the modification of eukaryotic initiation factor 5A (eIF5A) and the formation of the peculiar amino acid hypusine. Specific inhibitors of hypusine formation induce apoptosis that can be potentiated by the combination with cytokines such as interferon alpha (IFN alpha) that itself decreases hypusine synthesis. We have also demonstrated that the concomitant treatment of cancer cells with IFNa and the protein synthesis inhibitor fusion protein TGF alpha/Pseudomonas Aeruginosa toxin synergize in inducing cancer cell growth inhibition. Another way used by polyamines to induce apoptosis is the generation of intracellular oxidative stress through the interaction with bovine serum amine oxidase (BSAO). This enzyme used simultaneously to spermine induces apoptosis, necrosis, inhibition of cell proliferation and inhibition of DNA and protein synthesis in several cell types. The enzymatic oxidation products of polyamine, H2O2 and aldehyde(s) cause these effects. We have recently found that the cytotoxicity of anti-cancer agents, either etoposide or docetaxel, in cancer cells is potentiated in the presence of BSAO/Spermine. In conclusion, polyamine metabolites could be useful in the design of new therapeutic strategies

    2 years-long monitoring of <i>Codium elisabethae</i> population dynamics in the Azorian reef ecosystem (Faial Island) with seabed imagery

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    In the Site of Community Interest (Natura, 2000) of Monte-da-Guia (Faial, Azores), two sites were delimited in order to investigate particularly the links between habitat characteristics, population structure, distribution and dynamics of the green alga Codium elisabethae. The first site is a large protected rocky seafloor of an ancient volcano crater (20m deep) and classified as no-go reserve. It shows very high density stands of Codium elisabethae (up to 105 ind.m-2), representing the main vegetal biomass. At similar depth but distant of about two kilometers, the second site is in a more exposed area, where a sparse population (about 13 ind.m-2) occupies rocky tables and boulders emerging from shallow sandy deposits. These contrasting densities reflect different population dynamic equilibrium resulting from the particular environmental pressures of each site. A two year population survey started in August 2003, aiming principally at building submarine image mosaics of each site on a seasonal basis. Further, a computer assisted detection is run on the images to derive valuable information about the studied macroalgae. This technique allows to study a comparatively large zone regarding to the diving time invested so as to integrate spatial patchiness and to focus on the temporal evolution of well identified individuals. The imagery methodology was validated with in situ measurements, confirming the adequacy of the 1cm precision size histograms produced, when considering individuals larger than 5cm diameter. Seasonal fluctuations of growth rate (from 0.5 to 3cm.month-1) and primary production (from 1 to 15kg.m-².month-1) could be described. For both sites studied, density, biomass and cover rate seemed affected by a seasonal variation with reduction starting in end summer early autumn. In both sites, the reduction was sharp in the fall 2003 and population density didn’t recover completely in spring and summer 2004. During the following year, population of the protected site could maintain density and biomass, while population of the exposed site dropped continuously all year. Last processing step will search to relate statistically these different population evolutions to the benthic environmental constraints measured in both sites during the year 2004-2005 (temperature, currents, turbidity, photosynthetic active radiation, nutrients). Differences in hydrodynamic exposure of both sites could be part of the answer, but observed differences in the reproduction intensity of these two populations is an important factor, and remains unexplained
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