198 research outputs found
Selectivity and discards in the <i>Nephrops</i> fishery - Belgium. EEC Study Contract 1992/003: Final report
Introduction on the finfish by-catches and discards in the Belgian Norway lobster (<i>Nephrops norvegicus</i>) fishery
Effect of population structure, sampling strategy and sample size on the estimates of selection parameters for shrimp (<i>Crangon crangon</i>) trawls
In selectivity experiments with shrimp trawls, very high numbers of animals in the catches of single hauls are a common feature and therefore sub-sampling is inevitable. In order to find an acceptable balance between work-load and accuracy in the estimation of the selection parameters, it is important to have a sensible idea on the minimum numbers of shrimps to be measured in each catch fraction (cover, discards and landings). The present theoretical study tries to answer this question by means of computer simulations of different sampling strategies and sample sizes applied to catches with known size compositions. The results of the simulations are discussed in relation to population structure, shape of the cod-end selection curve, sampling strategy (as the relative amounts measured from the different catch fractions) and sample size, and the method used to calculate the selection parameters. Samples of 750 animals provide an acceptable compromize between work-load and reliability of the estimated selection parameters, provided that sufficient numbers of length classes are available. Population structure, selection curve and sample size (in that order) largely determine the reliability of the estimates, whereas sampling strategy, on the other hand, only has a minor effect
Ontwikkeling van een milieuvriendelijke visserijmethode voor de garnalenvisserij, gebaseerd op stimulering door elektrische pulsen. Nr. EOGFL 30-A41
Recreational sea fishing in Belgium: Monitoring the capacity, intensity and density at sea (first results)
Can dissonance engineering improve risk analysis of human–machine systems?
The paper discusses dissonance engineering and its application to risk analysis of human–machine systems. Dissonance engineering relates to sciences and technologies relevant to dissonances, defined as conflicts between knowledge. The richness of the concept of dissonance is illustrated by a taxonomy that covers a variety of cognitive and organisational dissonances based on different conflict modes and baselines of their analysis. Knowledge control is discussed and related to strategies for accepting or rejecting dissonances. This acceptability process can be justified by a risk analysis of dissonances which takes into account their positive and negative impacts and several assessment criteria. A risk analysis method is presented and discussed along with practical examples of application. The paper then provides key points to motivate the development of risk analysis methods dedicated to dissonances in order to identify the balance between the positive and negative impacts and to improve the design and use of future human–machine system by reinforcing knowledge
Mitigating seafloor disturbance of bottom trawl fisheries for North Sea sole Solea solea by replacing mechanical with electrical stimulation
Funding: ADR, NTH, PM, HP, JJP, TvK: European Maritime and Fisheries Fund (EMFF) through the Netherlands Ministry of Agriculture Nature and Food Quality (LNV) (Grand/Award Number: 1300021172); NO ADR, JD, ORE, NTH, AI, FO, HP, JJP, TvK: FP 7 project BENTHIS (grant no. 312088); NO.Peer reviewedPublisher PD
CLIMAR - Evaluatie van de impacts van klimaatverandering en aanpassingsmaatregelen voor mariene activiteiten
The protective effects of a phosphodiesterase 5 inhibitor, sildenafil, on postresuscitation cardiac dysfunction of cardiac arrest: metabolic evidence from microdialysis
Phylogenomics Reshuffles the Eukaryotic Supergroups
Background. Resolving the phylogenetic relationships between eukaryotes is an ongoing challenge of evolutionary biology. In recent years, the accumulation of molecular data led to a new evolutionary understanding, in which all eukaryotic diversity has been classified into five or six supergroups. Yet, the composition of these large assemblages and their relationships remain controversial. Methodology/Principle Findings. Here, we report the sequencing of expressed sequence tags (ESTs) for two species belonging to the supergroup Rhizaria and present the analysis of a unique dataset combining 29908 amino acid positions and an extensive taxa sampling made of 49 mainly unicellular species representative of all supergroups. Our results show a very robust relationship between Rhizaria and two main clades of the supergroup chromalveolates: stramenopiles and alveolates. We confirm the existence of consistent affinities between assemblages that were thought to belong to different supergroups of eukaryotes, thus not sharing a close evolutionary history. Conclusions. This well supported phylogeny has important consequences for our understanding of the evolutionary history of eukaryotes. In particular, it questions a single red algal origin of the chlorophyll-c containing plastids among the chromalveolates. We propose the abbreviated name ‘SAR’ (Stramenopiles+Alveolates+Rhizaria) to accommodate this new super assemblage of eukaryotes, which comprises the largest diversity of unicellular eukaryotes
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