334 research outputs found

    Competition between static gear of the small-scale fisheries in Algarve waters (southern Portugal)

    Get PDF
    Parallel fishing trials with 0.30 mm diameter monofilament gill nets and longlines using small hooks were carried out in the Algarve (southern Portugal) over a one-year period, 1997-1998, with the objective of comparing species composition, catch rates, discards and size ranges. Four hook sizes of 'Mustad' brand, round bent, flatted sea hooks (numbers 15, 13, 12 and 11) and four mesh sizes of 25, 30, 35 and 40 mm (nominal bar length) of gill nets were used in the trials. Overall, 84 species were caught, with gill nets taking 71 species and longlines 54 species and with 41 species caught by both gears. The amount of discarding was higher for gill nets than for longlines. The catch species composition differed between the two gears, with the commercially valuable sea breams dominating the longline catches whereas small pelagics were relatively more important in the gill nets. Multivariate analysis showed a clear separation between the different sizes of the two gears both in terms of numbers and weights per species. Algarve gill netters and longliners fish the same species assemblage on the same fishing grounds, but have clearly different impacts in terms of catch species composition, catch rates and sizes. This information will be useful for the improved management of these small-scale, multi-species, multi-gear fisheries, where different gears compete for scarce resources. In particular this study provides a basis for a more rational allocation of licenses and control of fishing effort

    A comparison of monofilament gillnet and small hook longline selectivity in a multispecies artisanal fishery in the Algarve, southern Portugal

    Get PDF
    As part of the ongoing studies concerned with the small-scale fisheries of the South of Portugal, experimental fishing was carried out with monofilament gillnets and small hook longlines within the same area. Sixty-two species were caught, of which 20 were common to both gears. Pronounced differences in terms of the relative importance of different species in the catches were observed. Size selection patterns also differed, with highly overlapped hook catch distributions and few species showing evidence for size selectivity. In contrast, strong selectivity was characteristic of species which tend to be wedged in gillnets. Whereas smaller stretched mesh sizes (particularly 40 and 50 mm) caught significant numbers of illegal sized fish, this was mininmal in the longlines. Some implications for management are discussed

    The LisbOn KInetics Boltzmann solver

    Get PDF
    LisbOn KInetics Boltzmann (LoKI-B) is an open-source simulation tool available at: https://github.com/IST-Lisbon/LoKIThe LisbOn KInetics Boltzmann (LoKI-B) is an open-source simulation tool (https://github.com/IST-Lisbon/LoKI) that solves a time and space independent form of the two-term electron Boltzmann equation, for non-magnetised non-equilibrium low-temperature plasmas excited by DC/HF electric fields from different gases or gas mixtures. LoKI-B was developed as a response to the need of having an electron Boltzmann solver easily addressing the simulation of the electron kinetics in any complex gas mixture (of atomic/molecular species), describing first and second-kind electron collisions with any target state (electronic, vibrational and rotational), characterized by any user-prescribed population. LoKI-B includes electron-electron collisions, it handles rotational collisions adopting either a discrete formulation or a more convenient continuous approximation, and it accounts for variations in the number of electrons due to non-conservative events by assuming growth models for the electron density. On input, LoKI-B defines the operating work conditions, the distribution of populations for the electronic, vibrational and rotational levels of the atomic/molecular gases considered, and the relevant sets of electron-scattering cross sections obtained from the open-access website LXCat (http://lxcat.net/). On output, it yields the isotropic and the anisotropic parts of the electron distribution function (the former usually termed the electron energy distribution function), the electron swarm parameters, and the electron power absorbed from the electric field and transferred to the different collisional channels. LoKI-B is developed with flexible and upgradable object-oriented programming under MATLAB (R), to benefit from its matrix-based architecture, adopting an ontology that privileges the separation between tool and data. This topical review presents LoKI-B and gives examples of results obtained for different model and real gases, verifying the tool against analytical solutions, benchmarking it against numerical calculationThis work was funded by Portuguese FCT-Fundacao para a Ciencia e a Tecnologia, under projects UID/FIS/50010/2013 and PTDC/FISPLA/1243/2014 (KIT-PLASMEBA)

    Reduction of elasmobranch by-catch in the hake semipelagic near-bottom longline fishery in the Algarve (Southern Portugal)

    Get PDF
    Elasmobranch fish, particularly deep-sea sharks, are the most important component of the by-catch of the hake semipelagic near-bottom 'pedra-e-bola' longline fishery in the Algarve (South Portugal) and most of these fish are discarded. The effects of the removal of the lower hooks were evaluated, in terms of target and by-catch reductions, by quantifying the catches of each hook relative to the distance from the bottom. The analysis showed that most European hake (Merluccius merluccius), the target species of this fishery, were caught in the middle range of the hooks, with very few individuals caught near the bottom, whereas for sharks the situation was the opposite, with most hooked near the bottom. The removal of the lower three pairs of hooks would result in a small reduction in the catch of the target species, but a much more significant reduction in elasmobranch by-catch. In the specific case of the blackmouth catshark (Galeus melastomus), discard mortality would be further minimized due to the fact that the lower hooks capture significantly smaller animals that are always discarded compared with hooks that are more distant from the bottom

    Data sharing: A new editorial initiative of the international committee of medical journal editors. Implications for the editors´ network

    Get PDF
    The International Committee of Medical Journal Editors (ICMJE) provides recommendations to improve the editorial standards and scientific quality of biomedical journals. These recommendations range from uniform technical requirements to more complex and elusive editorial issues including ethical aspects of the scientific process. Recently, registration of clinical trials, conflicts of interest disclosure, and new criteria for authorship -emphasizing the importance of responsibility and accountability-, have been proposed. Last year, a new editorial initiative to foster sharing of clinical trial data was launched. This review discusses this novel initiative with the aim of increasing awareness among readers, investigators, authors and editors belonging to the Editors´ Network of the European Society of Cardiolog

    Data sharing: A new editorial initiative of the international committee of medical journal editors. Implications for the editors´ network

    Get PDF
    The International Committee of Medical Journal Editors (ICMJE) provides recommendations to improve the editorial standards and scientific quality of biomedical journals. These recommendations range from uniform technical requirements to more complex and elusive editorial issues including ethical aspects of the scientific process. Recently, registration of clinical trials, conflicts of interest disclosure, and new criteria for authorship -emphasizing the importance of responsibility and accountability-, have been proposed. Last year, a new editorial initiative to foster sharing of clinical trial data was launched. This review discusses this novel initiative with the aim of increasing awareness among readers, investigators, authors and editors belonging to the Editors´ Network of the European Society of Cardiolog

    Authorship: From credit to accountability. Reflections from the Editors´ Network

    Get PDF
    The Editors´ Network of the European Society of Cardiology (ESC) provides a dynamic forum for editorial discussions and endorses the recommendations of the International Committee of Medical Journal Editors (ICMJE) to improve the scientific quality of biomedical journals. Authorship confers credit and important academic rewards. Recently, however, the ICMJE emphasised that authorship also requires responsibility and accountability. These issues are now covered by the new (fourth) criterion for authorship. Authors should agree to be accountable and ensure that questions regarding the accuracy and integrity of the entire work will be appropriately addressed. This review discusses the implications of this paradigm shift on authorship requirements with the aim of increasing awareness on good scientific and editorial practices

    Consistent improvement with eculizumab across muscle groups in myasthenia gravis

    Get PDF

    The Forward Physics Facility at the High-Luminosity LHC

    Get PDF
    • …
    corecore