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Yousef Dashti Tanja Grkovic Usama Ramadan Abdelmohsen Ute Hentschel Ronald J. Quinn 《Marine drugs》2014,12(5):3046-3059
Two sponge-derived actinomycetes, Actinokineospora sp. EG49 and Nocardiopsis sp. RV163, were grown in co-culture and the presence of induced metabolites monitored by 1H NMR. Ten known compounds, including angucycline, diketopiperazine and β-carboline derivatives 1–10, were isolated from the EtOAc extracts of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163. Co-cultivation of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163 induced the biosynthesis of three natural products that were not detected in the single culture of either microorganism, namely N-(2-hydroxyphenyl)-acetamide (11), 1,6-dihydroxyphenazine (12) and 5a,6,11a,12-tetrahydro-5a,11a-dimethyl[1,4]benzoxazino[3,2-b][1,4]benzoxazine (13a). When tested for biological activity against a range of bacteria and parasites, only the phenazine 12 was active against Bacillus sp. P25, Trypanosoma brucei and interestingly, against Actinokineospora sp. EG49. These findings highlight the co-cultivation approach as an effective strategy to access the bioactive secondary metabolites hidden in the genomes of marine actinomycetes. 相似文献
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Tanja Grkovic Johanna S. Blees Magdalena M. Bayer Nancy H. Colburn Cheryl L. Thomas Curtis J. Henrich Megan L. Peach James B. McMahon Tobias Schmid Kirk R. Gustafson 《Marine drugs》2014,12(8):4593-4601
A cell-based high-throughput screen that assessed the cellular stability of a tumor suppressor protein PDCD4 (Programmed cell death 4) was used to identify a new guanidine-containing marine alkaloid mirabilin K (3), as well as the known compounds mirabilin G (1) and netamine M (2). The structures of these tricyclic guanidine alkaloids were established from extensive spectroscopic analyses. Compounds 1 and 2 inhibited cellular degradation of PDCD4 with EC50 values of 1.8 μg/mL and 2.8 μg/mL, respectively. Mirabilin G (1) and netamine M (2) are the first marine natural products reported to stabilize PDCD4 under tumor promoting conditions. 相似文献
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Tanja Myllyviita Teppo Hujala Annika Kangas Kyle Eyvindson Susanna Sironen Pekka Leskinen 《Scandinavian Journal of Forest Research》2014,29(7):20-29
Multi-objective forest planning is a multi-methodological endeavor whose success largely depends on how well the combined use of different methods contributes to the goals of the planning. This review assessed the benefits of mixing methods in natural resources planning. A sample of 30 peer-reviewed research articles was analyzed using an evaluation framework, designed based on democracy and planning theories, and participatory planning literature, including four dimensions: transparency, flexibility, consensus building, and operability. According to analyses, mixing different types (i.e. qualitative and quantitative) of methods generally yields greater benefits than the combination of similar methods. The subsample of 12 planning cases that utilized simulation-optimization software (SOS) appeared operable and moderately transparent, whereas flexibility and consensus building were often lacking. In comparison to the wide scholarly discussion on multi-methodology and mixing methods, it was observed that successful mixing examples in natural resource planning are still scarce and there are weaknesses in bridging the methods together. There is an evident need to pursue and to better communicate the benefits of mixing. Some good mixing examples utilizing SOS provided evidence that forest planning processes would make an excellent venue for studying the benefits and caveats of using mixed methods. 相似文献
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Growth hormone (GH) and reproduction: a review 总被引:5,自引:0,他引:5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations. 相似文献
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Jackson JB Cubit JD Keller BD Batista V Burns K Caffey HM Caldwell RL Garrity SD Getter CD Gonzalez C Guzman HM Kaufmann KW Knap AH Levings SC Marshall MJ Steger R Thompson RC Weil E 《Science (New York, N.Y.)》1989,243(4887):37-44
In 1986 more than 8 million liters of crude oil spilled into a complex region of mangroves, seagrasses, and coral reefs just east of the Caribbean entrance to the Panama Canal. This was the largest recorded spill into coastal habitats in the tropical Americas. Many population of plants and animals in both oiled and unoiled sites had been studied previously, thereby providing an unprecedented measure of ecological variation before the spill. Documenation of the spread of oil and its biological begun immediately. Intertidal mangroves, algae, and associated invertebrates were covered by oil and died soon after. More surprisingly, there was also extensive mortality of shallow subtidal reef corals and infauna of seagrass beds. After 1.5 years only some organisms in areas exposed to the open sea have recovered. 相似文献
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Dorn RI Bamforth DB Cahill TA Dohrenwend JC Turrin BD Donahue DJ Jull AJ Long A Macko ME Weil EB Whitley DS Zabel TH 《Science (New York, N.Y.)》1986,231(4740):830-833
The first accelerator radiocarbon dates of rock varnishes are reported along with potassium/argon ages of lava flows and conventional radiocarbon dates of pluvial lake shorelines, in an empirical calibration of rock varnish K(+) + Ca(2+)/Ti(4+) ratios with age in the Mojave Desert, eastern California. This calibration was used to determine the cation-ratio dates of 167 artifacts. Although cation-ratio dating is an experimental method, some dates suggest human occupation of the Mojave Desert in the late Pleistocene. 相似文献
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We investigated the structure of invertebrate food webs at three glacier foreland sites of an age of 2-34, ca. 60 and ca. 120 years in the European Alps at 2250-2450 m asl. The trophic structure was investigated by analyzing stable isotope ratios of 15N/14N and 13C/12C. The results suggest that the formation of terrestrial food webs during early primary succession heavily relies on prey out of the decomposer system with Collembola being most important. The diet of decomposers likely is based predominantly on allochthonous humus material blown in by wind and deposited by the retreating glacier. Irrespective of the successional stage the animal community consisted mainly of generalist predators with a number of species occurring at each of the successional stages. The results suggest that terrestrial food web formation is associated with a prolongation of food chains caused mainly by predator species switching their diet to include other predators, i.e. by intraguild predation. This suggests that generalist predators, such as cursorial spiders, carabid beetles, harvestman and centipedes, switch prey and include other predators if these are becoming more abundant, i.e. if ecosystems become more productive. Intraguild predation results in complex food webs with high linkage density which likely affects food web functioning and stability. 相似文献