448 research outputs found

    Calibrating accelerometer tags with oxygen consumption rate of rainbow trout (Oncorhynchus mykiss) and their use in aquaculture facility: A case study

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    SIMPLE SUMMARY: Measuring metabolic rates in free-swimming fish would provide valuable insights about the energetic costs of different life activities this is challenging to implement in the field due to the difficulty of performing such measurements. Thus, the calibration of acoustic transmitters with the oxygen consumption rate (MO(2)) could be promising to counter the limitations observed in the field. In this study, calibrations were performed in rainbow trout (Oncorhynchus mykiss), and a subsample of fish was implanted with such a transmitter and then followed under aquaculture conditions. The use of acoustic transmitters calibrated with MO(2) appeared to be a promising tool to estimate energetic costs in free-swimming rainbow trout, and for welfare assessment in the aquaculture industry. ABSTRACT: Metabolic rates are linked to the energetic costs of different activities of an animal’s life. However, measuring the metabolic rate in free-swimming fish remains challenging due to the lack of possibilities to perform these direct measurements in the field. Thus, the calibration of acoustic transmitters with the oxygen consumption rate (MO(2)) could be promising to counter these limitations. In this study, rainbow trout (Oncorhynchus mykiss Walbaum, 1792; n = 40) were challenged in a critical swimming test (U(crit)) to (1) obtain insights about the aerobic and anaerobic metabolism throughout electromyograms; and (2) calibrate acoustic transmitters’ signal with the MO(2) to be later used as a proxy of energetic costs. After this calibration, the fish (n = 12) were implanted with the transmitter and were followed during ~50 days in an aquaculture facility, as a case study, to evaluate the potential of such calibration. Accelerometer data gathered from tags over a long time period were converted to estimate the MO(2). The MO(2) values indicated that all fish were reared under conditions that did not impact their health and welfare. In addition, a diurnal pattern with higher MO(2) was observed for the majority of implanted trout. In conclusion, this study provides (1) biological information about the muscular activation pattern of both red and white muscle; and (2) useful tools to estimate the energetic costs in free-ranging rainbow trout. The use of acoustic transmitters calibrated with MO(2), as a proxy of energy expenditure, could be promising for welfare assessment in the aquaculture industry

    Technical measures without enforcement tools: is there any sense? A methodological approach for the estimation of passive net length in small scale fisheries

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    Passive nets are currently among the most important fishing gears largely used along the Mediterranean coasts by the small scale fisheries sector. The fishing effort exerted by this sector is strongly correlated with net dimensions. Therefore, the use of passive nets is worldwide managed by defining net length and net drop. The EC Reg. 1967/2006 reports that the length of bottom-set and drifting nets may be also defined considering their weight or volume; however, no practical suggestions for fisheries inspectors are yet available. Consequently,  even if such technical measures are reasonable from a theoretical viewpoint, they are hardly suitable as a management tool, due to the difficulties in harbour control. The overall objective of this paper is to provide a quick methodological approach for the gross estimation of passive net length (by net type) on the basis of net volume. The final goal is to support fisheries managers with suitable advice for enforcement and control purposes. The results obtained are important for the management of the fishing effort exerted by small scale fisheries. The methodology developed in this study should be considered as a first attempt to tackle the tangled problem of net length estimation that can be easily applied in other fisheries and areas in order to improve the precision of the models developed herein

    Assessing fish–fishery dynamics from a spatially explicit metapopulation perspective reveals winners and losers in fisheries management

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    Sustainable management of living resources must reconcile biodiversity conservation and socioeconomic viability of human activities. In the case of fisheries, sustainable management design is made challenging by the complex spatiotemporal interactions between fish and fisheries. We develop a comprehensive metapopulation framework integrating data on species life-history traits, connectivity and habitat distribution to identify priority areas for fishing regulation and assess how management impacts are spatially distributed. We trial this approach on European hake fisheries in the north-western Mediterranean, where we assess area-based management scenarios in terms of stock status and fishery productivity to prioritize areas for protection. Model simulations show that local fishery closures have the potential to enhance both spawning stock biomass and landings on a regional scale compared to a status quo scenario, but that improving protection is easier than increasing productivity. Moreover, the interaction between metapopulation dynamics and the redistribution of fishing effort following local closures implies that benefits and drawbacks are heterogeneously distributed in space, the former being concentrated in the proximity of the protected site. A network analysis shows that priority areas for protection are those with the highest connectivity (as expressed by network metrics) if the objective is to improve the spawning stock, while no significant relationship emerges between connectivity and potential for increased landings. Synthesis and applications. Our framework provides a tool for (1) assessing area-based management measures aimed at improving fisheries outcomes in terms of both conservation and socioeconomic viability and (2) describing the spatial distribution of costs and benefits, which can help guide effective management and gain stakeholder support. Adult dispersal remains the main source of uncertainty that needs to be investigated to effectively apply our model to fisheries regulation

    Report of the 12th Liaison Meeting

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    The 12th Liaison meeting was held in Brussels on 8th and 9th October 2015 to address the following Terms of Reference: TOR 1. Discussion on possible follow-­‐‑up to the main outputs/recommendations of: ‱ The 2015 RCMs -­‐‑ specific recommendations addressed to the Liaison Meeting ‱ PGECON, PGDATA, PGMed – outcomes and recommendations from their 2015 meeting ‱ STECF EWG and STECF Plenary -­‐‑ outcomes and recommendations from their 2015 meetings ‱ Data end users (ICES, STECF, RFMOs – GFCM, IATTC, ICCAT, IOTC, WCPFC, NAFO, SPRFMO, CECAF, WECAFC) TOR2. End user feedback on data transmission and related issues ‱ Discuss feedback received from data end-­‐‑users on data transmission: main issues and possible harmonization of end user feedback to the Commission ‱ JRC data transmission IT platform: experience gained and future steps ‱ Discuss best practices on automatization of data upload by MS: data validation tools used by end users ‱ Discussion on new set-­‐‑up for STECF evaluation of AR2014 & data transmission 2014 used in 2015 – continue like this next year? ‱ Harmonisation and dissemination of DCF metadata: codelists, metiers, nomenclatures, best practices, standards ‱ RCM data calls – overview of how MS responded TOR 3. Regional cooperation ‱ Call for proposals MARE/2014/19 'ÊčStrengthening Regional Cooperation in the area of fisheries data collection– state of play'Êč. Presentation by a representative of the two RCG grants and discussions by LM thereafter. What should be the way forward? ‱ Regional databases ‱ Overview of use of the Regional Databases for RCMs in 2015 and problems identified ‱ Other developments (RDB trainings in 2015, RDB Med&BS development) ‱ Changes for the future – any recommendations from the LM? ‱ Future role of RCMs and DCF-­‐‑related meetings: best practices, coordination, cohesion and common structure in line with emerging needs of DCF TOR 4. EU MAP ‱ Discuss recommendations/ output of RCMs: List of proposed stocks, landing obligation, metiers ‱ Discuss design-­‐‑based sampling in relation to DCF: does it fulfil DCF requirements? TOR 5. Availability of data ‱ Overview of latest developments (DCF Database Feasibility Study and plans for a follow-­‐‑up study to this) TOR 6. AOB ‱ Agree on a list of recommendations relating to DCF (that MS will need to report on in their AR2015) – COM will provide a compilation of proposed recommendations from LM & STECF Plenaries in 2014 as input ‱ Prepare a list of recommended meetings for 2016 as guidance for MS ‱ Review and prioritize DCF-­‐‑related study proposals from RCMs, PGECON, EGs etc ‱ ICES update on workshop on concurrent sampling and plans to re-­‐‑evaluate survey

    Mu2e Technical Design Report

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    The Mu2e experiment at Fermilab will search for charged lepton flavor violation via the coherent conversion process mu- N --> e- N with a sensitivity approximately four orders of magnitude better than the current world's best limits for this process. The experiment's sensitivity offers discovery potential over a wide array of new physics models and probes mass scales well beyond the reach of the LHC. We describe herein the preliminary design of the proposed Mu2e experiment. This document was created in partial fulfillment of the requirements necessary to obtain DOE CD-2 approval.Comment: compressed file, 888 pages, 621 figures, 126 tables; full resolution available at http://mu2e.fnal.gov; corrected typo in background summary, Table 3.

    Observation of Cabibbo-suppressed two-body hadronic decays and precision mass measurement of the Ωc0\Omega_{c}^{0} baryon

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    The first observation of the singly Cabibbo-suppressed Ωc0→Ω−K+\Omega_{c}^{0}\to\Omega^{-}K^{+} and Ωc0→Ξ−π+\Omega_{c}^{0}\to\Xi^{-}\pi^{+} decays is reported, using proton-proton collision data at a centre-of-mass energy of 13 TeV13\,{\rm TeV}, corresponding to an integrated luminosity of 5.4 fb−15.4\,{\rm fb}^{-1}, collected with the LHCb detector between 2016 and 2018. The branching fraction ratios are measured to be B(Ωc0→Ω−K+)B(Ωc0→Ω−π+)=0.0608±0.0051(stat)±0.0040(syst)\frac{\mathcal{B}(\Omega_{c}^{0}\to\Omega^{-}K^{+})}{\mathcal{B}(\Omega_{c}^{0}\to\Omega^{-}\pi^{+})}=0.0608\pm0.0051({\rm stat})\pm 0.0040({\rm syst}), B(Ωc0→Ξ−π+)B(Ωc0→Ω−π+)=0.1581±0.0087(stat)±0.0043(syst)±0.0016(ext)\frac{\mathcal{B}(\Omega_{c}^{0}\to\Xi^{-}\pi^{+})}{\mathcal{B}(\Omega_{c}^{0}\to\Omega^{-}\pi^{+})}=0.1581\pm0.0087({\rm stat})\pm0.0043({\rm syst})\pm0.0016({\rm ext}). In addition, using the Ωc0→Ω−π+\Omega_{c}^{0}\to\Omega^{-}\pi^{+} decay channel, the Ωc0\Omega_{c}^{0} baryon mass is measured to be M(Ωc0)=2695.28±0.07(stat)±0.27(syst)±0.30(ext) MeV/c2M(\Omega_{c}^{0})=2695.28\pm0.07({\rm stat})\pm0.27({\rm syst})\pm0.30({\rm ext})\,{\rm MeV}/c^{2}, improving the precision of the previous world average by a factor of four.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-011.html (LHCb public pages

    Amplitude analysis of the Λb0→pK−γ decay

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    The resonant structure of the radiative decay Λb0→pK−γ in the region of proton-kaon invariant-mass up to 2.5 GeV/c2 is studied using proton-proton collision data recorded at centre-of-mass energies of 7, 8, and 13 TeV collected with the LHCb detector, corresponding to a total integrated luminosity of 9 fb−1. Results are given in terms of fit and interference fractions between the different components contributing to this final state. Only Λ resonances decaying to pK− are found to be relevant, where the largest contributions stem from the Λ(1520), Λ(1600), Λ(1800), and Λ(1890) states

    A study of CP violation in the decays B±→[K+K-π+π-]Dh± (h= K, π) and B±→[π+π-π+π-]Dh±

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    The first study of CP violation in the decay mode B±→[K+K-π+π-]Dh± , with h= K, π , is presented, exploiting a data sample of proton–proton collisions collected by the LHCb experiment that corresponds to an integrated luminosity of 9 \,fb - 1 . The analysis is performed in bins of phase space, which are optimised for sensitivity to local CP asymmetries. CP -violating observables that are sensitive to the angle Îł of the Unitarity Triangle are determined. The analysis requires external information on charm-decay parameters, which are currently taken from an amplitude analysis of LHCb data, but can be updated in the future when direct measurements become available. Measurements are also performed of phase-space integrated observables for B±→[K+K-π+π-]Dh± and B±→[π+π-π+π-]Dh± decays

    Measurement of lepton universality parameters in B+→K+ℓ+ℓ−B^+\to K^+\ell^+\ell^- and B0→K∗0ℓ+ℓ−B^0\to K^{*0}\ell^+\ell^- decays

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    A simultaneous analysis of the B+→K+ℓ+ℓ−B^+\to K^+\ell^+\ell^- and B0→K∗0ℓ+ℓ−B^0\to K^{*0}\ell^+\ell^- decays is performed to test muon-electron universality in two ranges of the square of the dilepton invariant mass, q2q^2. The measurement uses a sample of beauty meson decays produced in proton-proton collisions collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 99 fb−1\text{fb}^{-1}. A sequence of multivariate selections and strict particle identification requirements produce a higher signal purity and a better statistical sensitivity per unit luminosity than previous LHCb lepton universality tests using the same decay modes. Residual backgrounds due to misidentified hadronic decays are studied using data and included in the fit model. Each of the four lepton universality measurements reported is either the first in the given q2q^2 interval or supersedes previous LHCb measurements. The results are compatible with the predictions of the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-045.html (LHCb public pages
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