14 research outputs found

    The Dynamics of an Open-access Fishery: Baltic Sea Cod

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    This paper sets up a dynamic open-access model of a single industry exploiting a single resource stock. The model is applied empirically to describe the dynamics of the eastern Baltic Sea cod fishery. The theoretical model is based on the benchmark papers by Smith (1968, 1969). Types of steady state are discussed theoretically and the theory is applied to the eastern Baltic Sea cod fishery. The empirical path the fishery has been following since 1982 is determined and how it relates to the optimal path to steady state is discussed. Comparisons are made to other empirical studies, and the stability of the steady state is evaluated. The paper concludes that the Baltic Sea cod stock likely is on a path to a stable steady state, and it might not be a problem that the stock is below safe biological limits.Baltic sea cod, bio-economics, dynamic entry/exit, fisheries, open-access, stability of steady state, Resource /Energy Economics and Policy, Q21, Q22,

    Sharing Rules and Stability in Coalition Games with Externalities

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    This paper examines cooperative sharing rules in fisheries coalition games and develops a new sharing rule that takes into account the stability of cooperation when externalities are present. We contribute to existing knowledge by introducing a connection between cooperative games (sharing rules) and non-cooperative games (stability). As an illustrative example, we describe a discrete-time, deterministic, coalition game model of the major agents who exploit the cod stock in the Baltic Sea.Baltic Sea cod, characteristic function, coalition game, cooperation, fisheries, nucleolus, Shapley value, sharing rules, stability of cooperation, Environmental Economics and Policy, C62, C70, Q22, Q28,

    International fisheries agreements and non-consumptive values

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    The management of internationally shared fish stocks is a major economic, environmental and political issue. According to international law, these resources should be managed cooperatively under international fisheries agreements (IFAs). This paper studies the formation and stability of IFAs through a coalition game that accounts for both direct consumptive values (harvesting profits) and non-consumptive values of the fish stock per se. The results show that accounting for non-consumptive values helps conserve the fish stock in that equilibrium fishing efforts are smaller and fish stock larger than without non-consumptive values under all possible coalition scenarios (full, partial and no cooperation). However, considering non-consumptive values does not affect the outcome of the game in terms of the prospects for cooperation: even with substantial non-consumptive benefits, the outcome is full non-cooperation. Hence, the trap of non-cooperation in international fisheries management cannot be overcome simply by explicitly accounting for non-consumptive values within IFAs. It is suggested that strengthening the role of IFAs and limiting the ability of non-member countries to free-ride be further investigated as measures fostering cooperation.Peer reviewe

    Game theory and fisheries

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    Game theory studies the strategic interactions between and among decision makers, players, through mathematical models called games. This paper presents an overview on the evolution of the application of game theory to fisheries economics. The first applications emerged in the late 1970s, focussing upon internationally shared fish stocks. This occurred in the context of the UN Third Conference on the Law of the Sea, and the 1982 UN Convention on the Law of the Sea. During the 1980s and early 1990s the application of game theory to fisheries focused mainly on transboundary fish stocks. Thereafter, the applications to straddling fish stocks developed significantly, through the use of coalition games. This was a consequence of the mismanagement of these stocks, and the management regime brought forth in response by the 1995 UN Fish Stocks Agreement. The application of game theory to the management of national/regional fisheries is a new research frontier, as it is still much underexplored, when compared to international fisheries. This paper also summarizes the main research developments of a set of nine papers selected for this special issue on Game Theory and Fisheries.Peer reviewe

    International Fisheries Management and Recreational Benefits: The Case of Baltic Salmon

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    This article studies how accounting for the benefits of recreational fisheries affects the formation and stability of an international fisheries agreement (IFA) on the management of Baltic salmon stocks. The interaction between four countries is modelled through a partition function game, under two scenarios. In the first scenario, countries take their participation decision for the IFA based only on the net present value of profits from commercial fisheries. In the second scenario, the net present value of the recreational benefits from angling is also considered. The results show that accounting for recreational benefits leads to the formation of the grand coalition, whereas only partial cooperation occurs when payoffs are confined to profits from commercial fisheries

    Ibrutinib, lenalidomide, and rituximab in relapsed or refractory mantle cell lymphoma (PHILEMON) : a multicentre, open-label, single-arm, phase 2 trial

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    Background Regimens based on ibrutinib alone and lenalidomide and rituximab in combination show high activity in patients with relapsed or refractory mantle cell lymphoma. We hypothesised that the combination of all three drugs would improve efficacy compared with previously published data on either regimen alone. Methods In this multicentre, open-label, single-arm, phase 2 trial, we enrolled patients aged 18 years or older with relapsed or refractory mantle cell lymphoma who had previously been treated with at least one rituximab-containing regimen, an Eastern Cooperative Oncology Group performance status score of 0-3, and at least one site of measurable disease, and who met criteria for several laboratory-assessed parameters. Treatment was divided into an induction phase of 12 cycles of 28 days with all three drugs and a maintenance phase with ibrutinib and rituximab only (cycle duration 56 days), given until disease progression or unacceptable toxicity. In the induction phase, patients received intravenous (375 mg/m(2)) or subcutaneous (1400 mg) rituximab once a week during cycle 1 and then once every 8 weeks. Oral ibrutinib (560 mg once a day) was given to patients every day in the cycle, whereas oral lenalidomide (15 mg once a day) was given on days 1-21. The primary endpoint was overall response assessed in the intention-totreat population according to Lugano criteria. Safety analysis included all patients who received the treatment, irrespective of eligibility or duration of treatment. The trial is ongoing, but is no longer accruing patients, and is registered with ClinicalTrials. gov, number NCT02460276. Findings Between April 30, 2015, and June 1, 2016, we enrolled 50 patients with relapsed or refractory mantle cell lymphoma at ten centres in Sweden, Finland, Norway, and Denmark. At a median follow-up of 17.8 months (IQR 14.7-20.9), 38 (76%, 95% CI 63-86) patients had an overall response, including 28 (56%, 42-69) patients who had a complete response and ten (20%, 11-33) who had a partial response. The most common grade 3-4 adverse events were neutropenia (in 19 [38%] of 50 patients), infections (in 11 [22%] patients), and cutaneous toxicity (in seven [14%] patients). There were three treatment-related deaths during the study, two due to sepsis and one due to embolic stroke. Interpretation Our results provide preliminary evidence that the triplet combination of ibrutinib, lenalidomide, and rituximab is an active regimen in patients with relapsed or refractory mantle cell lymphoma, and should be evaluated in a prospective randomised controlled trial.Peer reviewe

    Detailed Long-Term Follow-Up of Patients Who Relapsed After the Nordic Mantle Cell Lymphoma Trials : MCL2 and MCL3

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    Mantle cell lymphoma (MCL) is an incurable disease with a highly variable clinical course. The prognosis after relapse is generally poor, and no standard of care exists. We investigated the postrelapse outcomes of 149 patients who were initially treated in the Nordic Lymphoma Group trials, MCL2 or MCL3, both representing intensive cytarabine-containing frontline regimens including autologous stem cell transplant. Patients with progression of disease before 24 months (POD24, n = 51, 34%) displayed a median overall survival of 6.6 months compared with 46 months for patients with later POD (n = 98, 66%; P < 0.001). MCL international prognostic index, cell proliferation marker, blastoid morphology, and TP53 mutations showed independent prognostic value irrespective of POD24, and in a combined, exploratory risk score, patients with 0, 1, 2-3, or 4-5 high-risk markers, respectively, displayed a 5-year overall survival of 62%, 39%, 31%, and 0%. By a comparison of median progression-free survival of the different salvage therapies in the relapse setting, bendamustine-rituximab was superior to all other combination chemotherapy regimens; however, it was also associated with longer responses to last line of therapy. Collectively, we confirm the prognostic impact of POD24 and highlight the relevance of other biomarkers, and we emphasize the importance of novel therapies for patients with high-risk features at first POD.Peer reviewe

    Molecular Monitoring after Autologous Stem Cell Transplantation and Preemptive Rituximab Treatment of Molecular Relapse; Results from the Nordic Mantle Cell Lymphoma Studies (MCL2 and MCL3) with Median Follow-Up of 8.5 Years

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    The main objectives of the present study were to monitor minimal residual disease (MRD) in the bone marrow of patients with mantle cell lymphoma (MCL) to predict clinical relapse and guide preemptive treatment with rituximab. Among the patients enrolled in 2 prospective trials by the Nordic Lymphoma Group, 183 who had completed autologous stem cell transplantation (ASCT) and in whom an MRD marker had been obtained were included in our analysis. Fresh samples of bone marrow were analyzed for MRD by a combined standard nested and quantitative real-time PCR assay for Bcl-1/immunoglobulin heavy chain gene (IgH) and clonal IgH rear-rangements. Significantly shorter progression-free survival (PFS) and overall survival (OS) was demonstrated for patients who were MRD positive pre-ASCT (54 patients) or in the first analysis post-ASCT (23 patients). The median PFS was only 20 months in those who were MRD-positive in the first sample post-ASCT, compared with 142 months in the MRD-negative group (PPeer reviewe

    Portal vein thrombosis; risk factors, clinical presentation and treatment

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    <p>Abstract</p> <p>Background</p> <p>Portal vein thrombosis (PVT) is increasingly frequently being diagnosed, but systematic descriptions of the natural history and clinical handling of the condition are sparse. The aim of this retrospective study was to describe risk factors, clinical presentation, complications and treatment of portal vein thrombosis in a single-centre.</p> <p>Methods</p> <p>Sixty-seven patients were identified in the electronic records from 1992 to 2005. All data were obtained from the patient records.</p> <p>Results</p> <p>One or more risk factors (e.g. prothrombotic disorder or abdominal inflammation) were present in 87%. Symptoms were abdominalia, splenomegaly, fever, ascites, haematemesis, and weight loss. Abdominalia and fever occurred more frequently in patients with acute PVT. Frequent complications were splenomegaly, oesophageal- and gastric varices with or without bleeding, portal hypertensive gastropathy and ascites. Varices and bleeding were more frequent in patients with chronic PVT. Patients who received anticoagulant therapy more frequently achieved partial/complete recanalization. Patients with varices who were treated endoscopically in combination with β-blockade had regression of the varices. The overall mortality was 13% in one year, and was dependent on underlying causes.</p> <p>Conclusion</p> <p>Most patients had a combination of local and systemic risk factors for PVT. We observed that partial/complete recanalization was more frequent in patients treated with anticoagulation therapy, and that regression of varices was more pronounced in patients who where treated with active endoscopy combined with pharmacological treatment.</p

    15-year follow-up of the Second Nordic Mantle Cell Lymphoma trial (MCL2) : prolonged remissions without survival plateau

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    In recent decades, the prognosis of Mantle Cell Lymphoma (MCL) has been significantly improved by intensified first-line regimens containing cytarabine, rituximab and consolidation with high-dose-therapy and autologous stem cell transplantation. One such strategy is the Nordic MCL2 regimen, developed by the Nordic Lymphoma Group. We here present the 15-year updated results of the Nordic MCL2 study after a median follow-up of 114years: For all patients on an intent-to-treat basis, the median overall and progression-free survival was 127 and 85years, respectively. The MCL International Prognostic Index (MIPI), biological MIPI, including Ki67 expression (MIPI-B) and the MIPI-B including mIR-18b expression (MIPI-B-miR), in particular, significantly divided patients into distinct risk groups. Despite very long response durations of the low and intermediate risk groups, we observed a continuous pattern of relapse and the survival curves never reached a plateau. In conclusion, despite half of the patients being still alive and 40% in first remission after more than 12years, we still see an excess disease-related mortality, even among patients experiencing long remissions. Even though we consider the Nordic regimen as a very good choice of regimen, we recommend inclusion in prospective studies to explore the benefit of novel agents in the frontline treatment of MCL.Peer reviewe
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