Droits à produire transférables : Le marché des concessions conchylicoles et ses effets non désirés

Cet article propose une analyse de l'évolution du système d'accès au foncier conchylicole en France ainsi qu'une étude de son fonctionnement actuel. Il traite la question de la répartition des moyens de production dans un secteur dominé par le modèle de l'exploitation familiale et ayant vocation à maintenir une base sociale créatrice d'emplois dans certaines zones d'activité du littoral. Le régime d'accès au foncier conchylicole s'apparente à un système de droits à produire transférables. Cependant, le développement spontané du marché des concessions conchylicoles dans un contexte de faible intervention de l'administration provoque des effets non désirés dont la manifestation est ici vérifiée empiriquement, sur données quantitatives et qualitatives. La discussion finale porte sur la recherche d'outils de régulation et d'indicateurs économiques pour un meilleur fonctionnement du marché des concessions.Foncier, Conchyliculture, Droits à produire, Répartition, Encadrement du marché

Comparing Economic Dynamics of Oyster and Mussel Farming, with Particular Emphasis on their Profitability: An Application in the Mont-Saint-Michel Bay (France)

This paper sets out an evaluation of profitability differentials within shellfish farming activities of the Mont-Saint-Michel Bay. The objective is to examine whether profitability differentials have consequences in terms of economic dynamics and of management arrangements. The paper divides into four parts. The first part presents a retrospective analysis of shellfish farming activities in the Bay, which are nowadays dominated by Pacific oyster (Crassostrea gigas) and Blue mussel (Mytilus edulis). The second part consists in measuring the economic performances of enterprises. The indicators are based on the data provided by two surveys conducted in 2002 (mussel-farming) and 2004 (oyster-farming); methodological difficulties due in particular to the status of shellfish farming land are addressed here. The third part examines the determinants of the profitability for each sector, the profitability being the result of a combination of factors such as natural productivity, technical practices, production costs and products pricing. The last part discusses the implications of profitability differentials. Profitability differentials seem to be correctly reflected in land prices, but not necessarily in the annual ground fees perceived by the Administration. However, shellfish farming profitability should be included in redistributive mechanisms, as its relation to primary resources exploitation and management is not neutral. Thus, empirical evidence suggests that profitability differentials create bargaining powers which influence the results of negotiation between actors regarding the management of the Mont-Saint-Michel Bay

Evaluation, comparison and differentiation of geopolymers by studying microstructural

Geopolymers are materials derived from an activation process materials with high content in silicon and aluminum, that in contact with an alkaline solution can acquire cementitious properties, and whose added value is to be environmentally friendly. This research have like objective to determine the efficiency of geopolymers using two different types of fly ash (FA) as a possible replacement of an alternative material to cement Portland (CP). The manufacturing process consisted of the FA activation using NaOH, the tests conducted included the chemical characterization of the FA through X-ray fluorescence (XRF) and X-ray Diffraction (XRD); as well as the determination of the compressive strength at various ages curing according to ASTM C10 and development of crystalline phases by XRD. The results showed that with increased age curing is achieved the development of resistance and the generation of crystalline phases, also acquiring compression strength above of 20 MPa at the age of 14 days cure.Peer ReviewedPostprint (published version

Venographic comparison of subcutaneous low-molecular weight heparin with oral anticoagulant therapy in the long-term treatment of deep venous thrombosis

Producción CientíficaPurpose: The primary objective of this study was to evaluate with venography the rate of thrombus regression after a fixed dose of low–molecular weight heparin (LMWH) per day for 3 months compared with oral anticoagulant therapy for deep venous thrombosis (DVT). Secondary endpoints were the comparisons of the efficacy and safety of both treatments. Methods: This study was designed as an open randomized clinical study in a university hospital setting. Of the 165 patients finally enrolled in the study, 85 were assigned LMWH therapy and 80 were assigned oral anticoagulant therapy. In the group randomized to oral anticoagulant therapy, the patients first underwent treatment in the hospital with standard unfractionated heparin and then coumarin for 3 months. Doses were adjusted with laboratory monitoring to maintain the international normalized ratio between 2.0 and 3.0. Patients in the LMWH group were administered subcutaneous injections of fixed doses of 40 mg enoxaparin (4000 anti-Xa units) every 12 hours for 7 days, and after discharge from the hospital, they were administered 40 mg enoxaparin once daily at fixed doses for 3 months without a laboratory control assay. A quantitative venographic score (Marder score) was used to assess the extent of the venous thrombosis, with 0 points indicating no DVT and 40 points indicating total occlusion of all deep veins. The rate of thrombus reduction was defined as the difference in quantitative venographic scores after termination of LMWH or coumarin therapy as compared with the scores obtained on the initial venographic results. The efficacy was defined as the ability to prevent symptomatic extension or recurrence of venous thromboembolism (documented with venograms or serial lung scans). The safety was defined as the occurrence of hemorrhages. Results: After 3 months of treatment, the mean Marder score was significantly decreased in both groups in comparison with the baseline score, although the effect of therapy was significantly better after LMWH therapy (49.4% reduction) than after coumarin therapy (24.5% reduction; P < .001). LMWH therapy and male gender were independently associated with an enhanced resolution of the thrombus. A lower frequency of symptomatic recurrent venous thromboembolism was also shown in patients who underwent treatment with LMWH therapy (9.5%) than with oral anticoagulant therapy (23.7%; P < .05), although this difference was entirely a result of recurrence of DVT. Bleeding complications were significantly fewer in the LMWH group than in the coumarin group (1.1% vs 10%; P < .05). This difference was caused by minor hemorrhages. Coumarin therapy and cancer were independently associated with an enhanced risk of complications. Subcutaneous heparin therapy was well tolerated by all patients. Conclusion: The patients who were allocated to undergo enoxaparin therapy had a significantly greater improvement in their quantitative venographic score, a significantl

Impact of Cultural Practices on the individual and Collective Economic Performances in Shellfish Farming: the Case of Oyster Farming in Baie Des Veys

The access regulation within the shellfish farming sector in France is based on a co-management system relying on both a national legislation, defining the general access conditions to maritime public grounds, and regional regulation systems, called “Regional Structural Schemes”. The latter specify the farming rules in cooperation with the administration, scientific and professional representatives. This regulation system, which aims at managing the common primary resources at the scale of a shellfish farming basin, is under review in the baie des Veys, on the Normandy coastline. In this context, biological modelling is used to assess the carrying capacity of the bay and to provide tools for modifying the RSS in a more sustainable way. Another objective of the study is to shift to bio-economic modelling, implying for the model to take into account extra technical and economical parameters. A specific survey has therefore been carried out for collecting detailed information on the cultural practices of the oyster farming companies, and for analysing the links with their structural characteristics and performance indicators, in terms of productivity and output. This article reviews the context of oyster farming in the baie des Veys from the environmental, socio-economic and institutional point of view. After the presentation of the methodology used for the survey, its results are analysed and a synthesis is made, leading to the identification of the main farming technical profiles. At this stage of the study, only theoretical developments on modelling are considered and outlooks in terms of collective management measures are discussed.Keywords: Aquaculture, Fisheries Economics, Aquaculture Efficiency and Managemen

Why, how, and how far should microbiological contamination in a coastal zone be mitigated? An application of the systems approach to the Thau lagoon (France)

Full text : http://archimer.ifremer.fr/doc/00136/24775/22959.pdf (Version "auteur", 0.77 Mo)International audienceThis paper describes the building of an integrated simulation tool based on a systems approach, and its contribution to local political discussion of the mitigation of microbiological contamination of the water in a coastal area. Local management schemes view water quality as a high-priority environmental objective. In practice, how far this objective is achieved depends on trade-offs between the costs of improved water treatment facilities and the acceptable impacts of water contamination. An in-the-field experiment in collaboration with local managers was carried out in the Thau lagoon on the French Mediterranean coast during the SPICOSA (Science and Policy Integration for Coastal System Assessment) project, from 2007 through 2011. It consisted of building a modeling platform and an integrated assessment framework for simulating exploratory scenarios. The modeling platform combines a dynamic contamination model, which represents the sources of microbiological contamination, wastewater treatment facilities, and physical mechanisms of lagoon contamination, with a prospective economic model, which estimates the patterns of development of economic activities in the area through a holistic approach. Exploratory scenarios are used to assess the risk of water contamination and the efficiency of management measures, under various assumptions about the evolution of the system. The contamination simulations suggest that the work currently planned by local authorities will be inadequate for preventing increased water pollution, and that additional but fairly inexpensive management measures for maintaining the current level of water quality should be considered. The integrated assessment framework estimates the ecological and socio-economic impacts of the various pollution mitigation policies in the broader context of possible local development patterns. The results illustrate how the systems approach may aid in the design of an applicable water policy based on operational objectives and feasible technical options. (C) 2013 Elsevier Ltd. All rights reserved

Evaluación y comparación de geopolimeros obtenidos de dos cenizas volantes mexicanas

Esta investigación se realizó con el fin de determinar las diferencias existentes en los geopolimeros obtenidos de dos tipos de cenizas volantes, las cuales fueron caracterizadas mediante FRX, DRX, FT-IT, del mismo modo se determinaron sus propiedades físicas por picnometría, adsorción de gases (método BET), DTP y MEB. El proceso de activación se llevó a cabo con NaOH 8M a 80°C por 3, 7, 14, 21, 28 y 90 días, realizando ensayos de compresión y módulo dinámico a los mismos, obteniendo una mejora en los resultados conforme aumenta el tiempo de curado, además se demostró que la variación de los contenidos óxidos y las propiedades físicas de las cenizas de partida, juegan uno de los factores más importantes en el desarrollo de los geles producto de reacción (determinado por TGA, FT-IR, DRX y MEB) y por ello la obtención de mejores propiedades mecánicas. (ANGLÈS) This research was conducted in order to determine the differences in the geopolymer obtained from two types of fly ash, which were characterized by XRF, XRD, FT-IR, just as its physical properties were determined by pycnometry, gas adsorption (BET method), PSD and SEM. The activation process was conducted with NaOH 8M at 80°C for 3, 7, 14, 21, 28 and 90 days, to performing compression tests and dynamic module, obtaining a improved results with increasing cure time, also it showed that the variation of oxide content and the physical properties of the starting ash, play one of the most important factors in the development of the reaction product gels (determined by TGA, FT-IR, XRD and SEM) and thus obtaining better mechanical properties.Postprint (published version

Genetic variability in CYP3A4 and CYP3A5 in primary liver, gastric and colorectal cancer patients

<p>Abstract</p> <p>Background</p> <p>Drug-metabolizing enzymes play a role in chemical carcinogenesis through enzymatic activation of procarcinogens to biologically reactive metabolites. The role of gene polymorphisms of several cytochrome P450 enzymes in digestive cancer risk has been extensively investigated. However, the drug-metabolizing enzymes with the broader substrate specificity, CYP3A4 and CYP3A5, have not been analyzed so far. This study aims to examine associations between common CYP3A4 and CYP3A5 polymorphisms and digestive cancer risk.</p> <p>Methods</p> <p>CYP3A4 and CYP3A5 genotypes were determined in 574 individuals including 178 patients with primary liver cancer, 82 patients with gastric cancer, 151 patients with colorectal cancer, and 163 healthy individuals.</p> <p>Results</p> <p>The variant allele frequencies for patients with liver cancer, gastric cancer, colorectal cancer and healthy controls, respectively, were: <it>CYP3A4*1B</it>, 4.8 % (95% C.I. 2.6–7.0), 3.7 % (0.8–6.6) 4.3% (2.0–6.6) and 4.3% (2.1–6.5); <it>CYP3A5*3</it>, 91.8 % (93.0–97.4), 95.7% (92.6–98.8), 91.7% (88.6–94.8) and 90.8% (87.7–93.9). The association between <it>CYP3A4*1B </it>and <it>CYP3A5*3 </it>variant alleles did not significantly differ among patients and controls. No differences in genotypes, allele frequencies, or association between variant alleles were observed with regard to gender, age at diagnosis, tumour site or stage.</p> <p>Conclusion</p> <p>Common polymorphisms on <it>CYP3A4 </it>and <it>CYP3A5 </it>genes do not modify the risk of developing digestive cancers in Western Europe.</p

Genetic variability of histamine receptors in patients with Parkinson's disease

<p>Abstract</p> <p>Background</p> <p>Changes in the density and expression of histamine receptors (HRH) have been detected in Parkinson's disease (PD) patients, and HRH antagonists bring about improvements in motor and other symptoms, thus suggesting that HRH play a role in the clinical response of PD patients. This study is aimed to analyse polymorphic variations of HRH in patients with PD.</p> <p>Methods</p> <p>Leukocytary DNA from 195 PD patients and a control group of 231 unrelated healthy individuals was studied for the nonsynonymous HRH1Leu449Ser and the promoter HRH2G-1018A polymorphisms by using amplification-restriction analyses.</p> <p>Results</p> <p>The HRH1Leu449Ser amino acid substitution was identified in two women with late-onset PD whereas it was not observed among healthy subjects. The HRH2G-1018A polymorphism was observed with allele frequencies = 3.59 (95% CI = 1.74–5.44) and 5.0 (95% CI = 3.00–6.96) for patients with PD and healthy controls, respectively. These frequencies were independent of gender and age of onset of the disease. Multiple comparison analyses revealed that differences were not statistically significant.</p> <p>Conclusion</p> <p>These results indicate that the polymorphisms analyzed are not a major risk factor for PD, although the HRH1Leu449Ser amino acid substitution might be related to PD.</p

Two common nonsynonymous paraoxonase 1 (PON1) gene polymorphisms and brain astrocytoma and meningioma

<p>Abstract</p> <p>Background</p> <p>Human serum paraoxonase 1 (PON1) plays a major role in the metabolism of several organophosphorus compounds. The enzyme is encoded by the polymorphic gene <it>PON1</it>, located on chromosome 7q21.3. Aiming to identify genetic variations related to the risk of developing brain tumors, we investigated the putative association between common nonsynonymous <it>PON1 </it>polymorphisms and the risk of developing astrocytoma and meningioma.</p> <p>Methods</p> <p>Seventy one consecutive patients with brain tumors (43 with astrocytoma grade II/III and 28 with meningioma) with ages ranging 21 to 76 years, and 220 healthy controls subjects were analyzed for the frequency of the nonsynonymous <it>PON1 </it>genotypes L55M rs854560 and Q192R rs662. All participants were adult Caucasian individuals recruited in the central area of Spain.</p> <p>Results</p> <p>The frequencies of the <it>PON1 </it>genotypes and allelic variants of the polymorphisms <it>PON1 </it>L55M and <it>PON1 </it>Q192R did not differ significantly between patients with astrocytoma and meningioma and controls. The minor allele frequencies were as follows: <it>PON1 </it>55L, 0.398, 0.328 and 0.286 for patients with astrocytoma, meningioma and control individuals, respectively; <it>PON1 </it>192R, 0.341, 0.362 and 0.302 for patients with astrocytoma, meningioma and control individuals, respectively. Correction for age, gender, or education, made no difference in odds ratios and the <it>p </it>values remained non-significant. Haplotype association analyses did not identify any significant association with the risk of developing astrocytoma or meningioma.</p> <p>Conclusions</p> <p>Common nonsynonymous <it>PON1 </it>polymorphisms are not related with the risk of developing astrocytoma and meningioma.</p