96 research outputs found

    Evidence of package trading in a mature multi-species ITQ market

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    In multi-species fisheries managed under ITQs, the existence of joint production may lead to complex catch-quota balancing issues. Previous modelling and experimental research suggest that, in such fisheries, some fishers may benefit from the ability to trade packages of fishing quotas, rather than fulfil their quota needs by simultaneously bidding on separate single-species quota markets. This note presents evidence of naturally occurring package trades in a real fishery. Based on this evidence, we suggest that further empirical and modelling research is required on the potential and limitations of package quota trading in mixed fisheries managed with ITQs. © 2014

    The influence of fiscal regulations on investment in marine fisheries: A French case study

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    Analysing investment drivers in fisheries is essential in understanding the long-term development of fishing capacity. This paper addresses the drivers of investment in the French commercial fishing fleets operating along the Atlantic coast, and the role of public policies have had on investment. First, we examine the changes in the capital value of the fleet, which was strongly impacted by decommissioning schemes during the nineties. We then examine drivers of investment using an unbalanced panel data set describing the investment decisions of a sample of firms over the period 1994–2004. In addition to economic variables, the estimated models account for other factors that may have an impact on investment behaviour, including the different career phases of the skipper-owners. The study concludes with a discussion of the results, and in particular of the role of fiscal policy on observed investment strategies

    Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach

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    Cooperation is of utmost importance to society as a whole, but is often challenged by individual self-interests. While game theory has studied this problem extensively, there is little work on interactions within and across groups with different preferences or beliefs. Yet, people from different social or cultural backgrounds often meet and interact. This can yield conflict, since behavior that is considered cooperative by one population might be perceived as non-cooperative from the viewpoint of another. To understand the dynamics and outcome of the competitive interactions within and between groups, we study game-dynamical replicator equations for multiple populations with incompatible interests and different power (be this due to different population sizes, material resources, social capital, or other factors). These equations allow us to address various important questions: For example, can cooperation in the prisoner's dilemma be promoted, when two interacting groups have different preferences? Under what conditions can costly punishment, or other mechanisms, foster the evolution of norms? When does cooperation fail, leading to antagonistic behavior, conflict, or even revolutions? And what incentives are needed to reach peaceful agreements between groups with conflicting interests? Our detailed quantitative analysis reveals a large variety of interesting results, which are relevant for society, law and economics, and have implications for the evolution of language and culture as well

    A simple dynamic model explains the diversity of island birds worldwide

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    Streptococcus pneumoniae-associated pneumonia complicated by purulent pericarditis: case series

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    AbstractObjective: In the antibiotic era, purulent pericarditis is a rare entity. However, there are still reports of cases of the disease, which is associated with high mortality, and most such cases are attributed to delayed diagnosis. Approximately 40-50% of all cases of purulent pericarditis are caused by Gram-positive bacteria, Streptococcus pneumoniae in particular.Methods: We report four cases of pneumococcal pneumonia complicated by pericarditis, with different clinical features and levels of severity.Results: In three of the four cases, the main complication was cardiac tamponade. Microbiological screening (urinary antigen testing and pleural fluid culture) confirmed the diagnosis of severe pneumococcal pneumonia complicated by purulent pericarditis.Conclusions: In cases of pneumococcal pneumonia complicated by pericarditis, early diagnosis is of paramount importance to avoid severe hemodynamic compromise. The complications of acute pericarditis appear early in the clinical course of the infection. The most serious complications are cardiac tamponade and its consequences. Antibiotic therapy combined with pericardiocentesis drastically reduces the mortality associated with purulent pericarditis

    The nature and extent of evidence on methodologies for monitoring and evaluating marine spatial management measures in the UK and similar coastal waters : a systematic map

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    Background: Anthropogenic degradation of marine ecosystems is widely accepted as a major social-ecological problem. The growing urgency to manage marine ecosystems more effectively has led to increasing application of spatial management measures (marine protected areas [MPAs], sectoral [e.g. fishery] closures and marine spatial planning [marine plans]). Understanding the methodologies used to evaluate the effectiveness of these measures against social, economic, and ecological outcomes is key for designing effective monitoring and evaluation programmes. Methods: We used a pre-defined and tested search string focusing on intervention and outcome terms to search for relevant studies across four bibliographic databases, Google Scholar, 39 organisational websites, and one specialist data repository. Searches were conducted in English and restricted to the period 2009 to 2019 to align with current UK marine policy contexts. Relevant studies were restricted to UK-relevant coastal countries, as identified by key stakeholders. Search results were screened for relevance against pre-defined eligibility criteria first at title and abstract level, and then at full text. Articles assessed as not relevant at full text were recorded with reasons for exclusion. Two systematic map databases of meta-data and coded data from relevant primary and secondary studies, respectively, were produced. Review findings: Over 19,500 search results were identified, resulting in 391 relevant primary articles, 33 secondary articles and 49 tertiary reviews. Relevant primary articles evaluated spatial management measures across a total of 22 social, economic and ecological outcomes; only 2.8% considered all three disciplines, with most focused exclusively on ecological (67.8%) or social (13.3%) evaluations. Secondary articles predominately focused on ecological evaluations (75.8%). The majority of the primary and secondary evidence base aimed to evaluate the effectiveness of MPAs (85.7% and 90.9% respectively), followed by fisheries closures (12.5%; 3.0%) with only 1.8% of primary, and 6.1% of secondary, articles focused on marine plans or on MPAs and fisheries closures combined. Most evaluations reported within primary articles were conducted for a single site (60.4%) or multiple individual sites (32.5%), with few evaluating networks of sites (6.9%). Secondary articles mostly evaluated multiple individual sites (93.9%). Most (70.3%) primary articles conducted principal evaluations, i.e. basic description of effects; 29.4% explored causation; and 0.3% undertook benefit evaluations. Secondary articles predominately explored causation (66.7%) with the remainder conducting principal evaluations. Australia (27.4%), the USA (18.4%) and the UK (11.3%) were most frequently studied by primary articles, with secondary articles reporting mostly global (66.7%) or European (18.2%) syntheses. Conclusions: The systematic map reveals substantial bodies of evidence relating to methods of evaluating MPAs against ecological outcomes. However, key knowledge gaps include evaluation across social and economic outcomes and of overall merit and/or worth (benefit evaluation), as well as of: marine plans; networks of sites; real-time, temporary or seasonal closures; spatial management within offshore waters, and lagoon or estuary environments. Although the evidence base has grown over the past two decades, information to develop comprehensive evaluation frameworks remains insufficient. Greater understanding on how to evaluate the effectiveness of spatial management measures is required to support improved management of global ocean resources and spaces
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