228 research outputs found

    The African hind's (Cephalopholis taeniops, serranidae) use of artificial reefs off Sal Island (Cape Verde): a preliminary study based on acoustic telemetry

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    The African hind Cephalopholis taeniops (Valenciennes, 1828) is one of the most important commercial demersal species caught in the Cape Verde archipelago. The species is closely associated with hard substrate and is one of the main attractions for SCUBA divers. In January 2006 a former Soviet fishing vessel - the Kwarcit - was sunk off Santa Maria Bay (Sal Island). Young C. taeniops are commonly observed in this artificial reef (AR). In order to investigate the species' use of the AR, 4 specimens were captured and surgically implanted underwater with Vemco brand acoustic transmitters. The fish were monitored daily with an active telemetry receiver for one week after release. Simultaneously, an array of 3 passive VR2 / VR2W receivers was set for 63 days, registering data that allowed an analysis of spatial, daily and short term temporal activity patterns. The results showed site fidelity to the AR, with no migrations to the nearby natural reef. The method used allowed to register a consistent higher activity during daytime and a preference for the area opposite the dominant current

    Ichthyological Bulletin J.L.B. Smith Institute of Ichthyology; No. 63

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    Recent collections of fishes from the South Atlantic islands of the Tristan da Cunha Group (Tristan, Inaccessible and Nightingale) and Gough Island have produced 25 new records. Fifty one species are known to occur in the near-shore waters of the islands (46 of these are documented by specimens and another 5 species are probable). A diagnosis, synonymy and in most cases, an illustration, are provided for each species. For certain species, brief notes on biology, relative abundance and seasonal distribution are included. The neritic ichthyofauna of the Subtropical Convergence (STC) region is characterized, and the importance of this frontal zone as a barrier to dispersal of species in the Southern Ocean is evaluated. Analysis of the zoogeographic affinities of the Tristan/Gough fish fauna resulted in a redefinition of the West Wind Drift Islands Province (WWDI), comprising the Tristan Group and Gough in the South Atlantic and St. Paul and Amsterdam Islands in the southern Indian Ocean. Verna Seamount (west of Cape Town) and Walters Shoal (south of Madagascar) are excluded from the WWDI Province, as the affinities of their poorly-known fish faunas appear to be more with South Africa and the tropical Indian Ocean respectively.Rhodes University Libraries (Digitisation

    Crystallographic Evidence of Drastic Conformational Changes in the Active Site of a Flavin-Dependent

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    The soil actinomycete Kutzneria sp. 744 produces a class of highly decorated hexadepsipeptides, which represent a new chemical scaffold that has both antimicrobial and antifungal properties. These natural products, known as kutznerides, are created via nonribosomal peptide synthesis using various derivatized amino acids. The piperazic acid moiety contained in the kutzneride scaffold, which is vital for its antibiotic activity, has been shown to derive from the hydroxylated product of l-ornithine, l-N5-hydroxyornithine. The production of this hydroxylated species is catalyzed by the action of an FAD- and NAD(P)H-dependent N-hydroxylase known as KtzI. We have been able to structurally characterize KtzI in several states along its catalytic trajectory, and by pairing these snapshots with the biochemical and structural data already available for this enzyme class, we propose a structurally based reaction mechanism that includes novel conformational changes of both the protein backbone and the flavin cofactor. Further, we were able to recapitulate these conformational changes in the protein crystal, displaying their chemical competence. Our series of structures, with corroborating biochemical and spectroscopic data collected by us and others, affords mechanistic insight into this relatively new class of flavin-dependent hydroxylases and adds another layer to the complexity of flavoenzymes.National Center for Research Resources (U.S.) (P41RR012408)National Institute of General Medical Sciences (U.S.) (P41GM103473

    Characteristics of clinical trials in rare vs. common diseases : A register-based Latvian study

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    Publisher Copyright: © 2018 Logviss et al. This is an open ccess article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and eproduction in any medium, provided the original author and source are credited.Background Conducting clinical studies in small populations may be very challenging; therefore quality of clinical evidence may differ between rare and non-rare disease therapies. Objective This register-based study aims to evaluate the characteristics of clinical trials in rare diseases conducted in Latvia and compare them with clinical trials in more common conditions. Methods The EU Clinical Trials Register (clinicaltrialsregister.eu) was used to identify interventional clinical trials related to rare diseases (n = 51) and to compose a control group of clinical trials in non-rare diseases (n = 102) for further comparison of the trial characteristics. Results We found no significant difference in the use of overall survival as a primary endpoint in clinical trials between rare and non-rare diseases (9.8% vs. 13.7%, respectively). However, clinical trials in rare diseases were less likely to be randomized controlled trials (62.7% vs. 83.3%). Rare and non-rare disease clinical trials varied in masking, with rare disease trials less likely to be double blind (45.1% vs. 63.7%). Active comparators were less frequently used in rare disease trials (36.4% vs. 58.8% of controlled trials). Clinical trials in rare diseases enrolled fewer participants than those in non-rare diseases: In Latvia (mean 18.3 vs. 40.2 subjects, respectively), in the European Economic Area (mean 181.0 vs. 626.9 subjects), and in the whole clinical trial (mean 335.8 vs. 1406.3 subjects). Although, we found no significant difference in trial duration between the groups (mean 38.3 vs. 36.4 months). Conclusions The current study confirms that clinical trials in rare diseases vary from those in non-rare conditions, with notable differences in enrollment, randomization, masking, and the use of active comparators. However, we found no significant difference in trial duration and the use of overall survival as a primary endpoint.publishersversionPeer reviewe
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