Pouvoirs locaux, usages communautaires et zones humides dans les îles Shetland au XVIIIe siècle

Les îles Shetland connaissent de profonds changements sociaux au XVIIIe siècle. Pour les auteurs contemporains comme Adam Smith, le plus symptomatique d’entre eux est la mise en place des « tenures à poissons » sur lesquelles les tenanciers paient leur rente en poissons. Bien qu’influencés par l’idéologie dominante de la physiocratie agricole, les pouvoirs locaux shetlandais délaissent pour un temps leurs terres arables et concentrent leur attention sur la richesse des fonds marins. Pour pêcher, il leur faut des hommes et pour faire rester ces hommes dans les Shetland, il faut leur conserver un « espace de respiration » comme l’a si bien écrit Brian Smith. C’est ce rôle d’« espace de respiration » que tiendront les zones humides au cours du XVIIIe siècle.The Shetland Islands underwent important social changes in the 18th century. For contemporaries like Adam Smith, the most symptomatic of them was the establishment of “fishing tenures” for which the tenants paid their rent in fish. Although influenced by the dominant ideology of agricultural improvement, Shetland local powers abandoned their farmlands for a time and focused their attention on the wealth of the sea. But in order to fish, they needed men and they needed the men to stay in Shetland and in order to do that they had to offer them what Brian Smith described as a “breathing space”. It was this role of “breathing space” that the wetlands held during the 18th century

Suppression by thimerosal of ex-vivo CD4+ T cell response to influenza vaccine and induction of apoptosis in primary memory T cells.

International audienceThimerosal is a preservative used widely in vaccine formulations to prevent bacterial and fungal contamination in multidose vials of vaccine. Thimerosal was included in the multidose non-adjuvanted pandemic 2009 H1N1 vaccine Panenza. In the context of the analysis of the ex-vivo T cell responses directed against influenza vaccine, we discovered the in vitro toxicity Panenza, due to its content in thimerosal. Because thimerosal may skew the immune response to vaccines, we investigated in detail the ex-vivo effects of thimerosal on the fate and functions of T cells in response to TCR ligation. We report that ex-vivo exposure of quiescent or TCR-activated primary human T cells to thimerosal induced a dose-dependent apoptotic cell death associated with depolarization of mitochondrial membrane, generation of reactive oxygen species, cytochrome c release from the mitochondria and caspase-3 activation. Moreover, exposure to non-toxic concentrations of thimerosal induced cell cycle arrest in G0/G1 phase of TCR-activated T cells, and inhibition of the release of proinflammatory cytokines such as IFN gamma, IL-1 beta, TNF alpha, IL-2, as well as the chemokine MCP1. No shift towards Th2 or Th17 cells was detected. Overall these results underline the proapoptotic effect of thimerosal on primary human lymphocytes at concentrations 100 times less to those contained in the multidose vaccine, and they reveal the inhibitory effect of this preservative on T-cell proliferation and functions at nanomolar concentrations

The Scandinavian intangible heritage of the Shetland Islands in the 18th century

International audienc

Autour de la question des cultures temporaires : les îles Shetland et les systèmes agraires de Norvège et d’Écosse (xve-xixe siècle)

Dans un article paru en 1957 dans les Annales, Pierre Flatrès, géographe ruraliste rennais, compare les structures rurales en Norvège et dans les « contrées celtiques », à savoir la Bretagne, l’Irlande, le Pays de Galles et l’Écosse sur lesquelles il travaille depuis plusieurs années. Il souhaite les comparer avec la Norvège en s’appuyant sur un ouvrage publié en anglais sous la direction d’Andreas Holmsen, professeur d’histoire à l’université d’Oslo, The Old Norwegian Peasant Community. Aprè..

Les femmes, le travail et la mer au XVIIIe siècle dans les îles Shetland

En 1813, la poétesse shetlandaise, Margaret Chalmers, publie un recueil intitulé Poems. C’est dans le poème To the United Trades’ Society of Lerwick que figure cette strophe : Que les échanges utiles puissent étendre son sourireAutour de nos Îles mornes, détachées et encerclées par la mer.Un murmure de génie à l’esprit du patriote,Où trouver un marché profitable,Pour les produits de Thulé ; nous indique où chercherUne acceptation immédiate pour nos produits en laine,En matières « tissées, lus..

Terre, mer et communautés dans les iles Shetland au XVIIIe siècle

In a rental of the arable land of Shetland, written in the early 1770s, the following expression appeared: “The inhabitants of the Towns within the same Scattald are called scatt brethren.” These few words triggered a series of questions. What is a scattald? What is the scatt? Who are these ‘scatt brothers’? Research at the National Records of Scotland and at the Shetland Archives as well as the reading of academic literature on the questions of communities, commons, custom, local judicial systems and rural life in the early modern period led to the writing of a thesis on communities in the 18th century. These communities lived in a peculiar geographical context: the Shetland Islands. Without underestimating the role of the local environment in the life of the Shetlanders, this thesis shows that the surroundings of the Shetlanders were more a place of possibilities than a place of restrictions; it brought constraints, but any other surroundings in early modern Europe had its limitations. The life on the islands of Shetland was as anywhere else on mainland Scotland at the same period a life based on local resources and which saw the development of a market economy with its advantages and disadvantages for the inhabitants. In Shetland the market economy took the form of the fishing tenures with their specific share-cropping contracts.In order to understand these communities the thesis starts with how they were regulated. The regulations, the courts and their personnel all had a role to play in the social control of the members of the communities. This thesis also explores the activities of the communities’ members in their environment. Shetland as well as several regions in Northwest Europe at the same time was a place of pluriactivité, multi-tasking. Through multi-tasking and access to the commons, the scattald communities of Shetland kept a certain level of independence even in time of debt-bondage. This paradoxical relationship was rendered possible by an almost unlimited access to the commons throughout the 18th century, a time during which the movement on the commons were possible and the transmission of the memory of their boundaries stayed alive. Changes, however, happened on the islands during these times. The fishing tenures were only one element of these changes: women started to outnumber men, the size of the arable land cultivated by one household diminished, the protected commons were slowly nibbled, and a regional court offered more possibilities for justice to the higher ranks than to the tenants... Eventually, this thesis argues that local communities in 18th-century Shetland offered protection to women and men who through them had an organised support systemDans un rentier des terres arables des îles Shetland, écrit au début des années 1770, l’expression suivante apparut : « Les habitants des villages d’un même scattald sont appelés frères de scatt ». Ces quelques mots déclenchèrent une série de questions : qu’est-ce qu’un scattald ? Qu’est-ce que le scatt ? Qui sont ces frères de scatt ? Des recherches aux Archives Nationales d’Écosse et aux archives des îles Shetland ainsi que la lecture de travaux universitaires sur les questions des communautés, des communs, des coutumes, des systèmes de justice locale et sur la vie rurale à l’époque moderne conduisirent à l’écriture de cette thèse sur les communautés des îles Shetland au XVIIIe siècle. Ces communautés vivaient dans un contexte géographique particulier. Sans sous estimer le rôle de l’environnement local dans la vie des Shetlandais, cette thèse montre que celui-ci était plus un espace de possibilités que de restrictions ; il apportait des contraintes, mais tout autre environnement dans l’Europe moderne avait aussi ses limites. La vie dans les îles Shetland était, comme n’importe où en Écosse à la même époque, fondée sur les ressources locales et le développement de l’économie de marché apporta ses avantages et ses inconvénients aux habitants. Dans les îles Shetland, l’économie de marché entraîna le développement des tenures à poissons avec leurs contrats particuliers de métayage.Pour comprendre ces communautés, la thèse s’ouvre sur la manière dont elles étaient régulées. Les lois, les cours et le personnel judiciaire avaient tous un rôle à jouer dans le contrôle social des membres des communautés. Cette thèse explore aussi les activités des membres des communautés dans leur environnement. Les îles Shetland comme de nombreuses régions du nord-ouest de l’Europe à la même époque, étaient un espace de pluriactivité. À travers la pluriactivité et l’accès aux communs, les communautés shetlandaises des scattalds gardèrent un certain niveau d’indépendance même à une époque où existait la servitude pour dettes. Cette relation particulière fut rendue possible par un accès presque illimité aux communs pendant tout le XVIIIe siècle, époque pendant laquelle les déplacements sur les communs étaient possibles et où la transmission de la mémoire de ses frontières restait vivante. Des changements eurent cependant lieu sur les îles Shetland à cette époque. Les tenures à poissons ne furent qu’un élément de ces changements : les femmes commencèrent à être plus nombreuses que les hommes, la taille des terres arables cultivées par foyer diminua, les communs protégés furent lentement grignotés, et la cour de justice régionale offrit plus de possibilités de justice aux plus hauts rangs qu’aux tenanciers… Finalement, cette thèse soutient qu’au XVIIIe siècle, les communautés locales shetlandaises offraient une protection aux femmes et aux hommes qui à travers elles avaient un système de soutien organisé

Stickleback mathematical models to improve ecotoxicological risk assessments : from toxicokinetic to population dynamics

The integration of stickleback mechanistic models in environmental risk assessment can describe the complex processes linking exposure or environmental concentrations (external dose) to internal dose, up to toxicity in a given population, community or the whole ecosystem. Two phases can be distinguished in the dose-response relationship of a chemical in an organism, or at higher level of organisation: the toxicokinetics (TK), that is the fate of the compound in the organism including absorption, distribution, metabolism and excretion (ADME), and the toxicodynamics (TD), that is the expression of the toxicity/effect of the substance. The stickleback offers the opportunity in a same biological model to integrate all these processes, and then, to describe for a given substance the TK, TD at the organism and population levels. A Physiological-based TK model (PBTK) has been developed for sticklebacks. This model integrates the main physiological characteristics to model ADME processes, including the stickleback growth and the impacts of the water temperature on these processes. This model was evaluated using data obtained on chlorpyrifos (water exposure), and provided accurate predictions. To extrapolate toxic effects from the individuals to the population level, a convenient approach is to use Individual-Based Models (IBMs) coupled to a bioenergetic dynamic model describing the physiological processes of the individuals (Dynamic Energy Budget theory). Accordingly, a DEB-IBM model was developed for describing the population dynamics of sticklebacks in artificial streams (mesocosms). The model predictions were compared to the data observed in a mesocosm experiment to assess the impacts of an endrocrine disruptor, the bisphenol A. The DEB-IBM provided great insight of the effects of Bisphenol A on the population dynamics. The mathematical models developed for sticklebacks coupled to the use of this fish in active biomonitoring strategy which integrate a multiFbiomarker approach highlight the strengths of the stickleback in environmental risk assessments

Stickleback mathematical models to improve ecotoxicological risk assessments : from toxicokinetic to population dynamics

The integration of stickleback mechanistic models in environmental risk assessment can describe the complex processes linking exposure or environmental concentrations (external dose) to internal dose, up to toxicity in a given population, community or the whole ecosystem. Two phases can be distinguished in the dose-response relationship of a chemical in an organism, or at higher level of organisation: the toxicokinetics (TK), that is the fate of the compound in the organism including absorption, distribution, metabolism and excretion (ADME), and the toxicodynamics (TD), that is the expression of the toxicity/effect of the substance. The stickleback offers the opportunity in a same biological model to integrate all these processes, and then, to describe for a given substance the TK, TD at the organism and population levels. A Physiological-based TK model (PBTK) has been developed for sticklebacks. This model integrates the main physiological characteristics to model ADME processes, including the stickleback growth and the impacts of the water temperature on these processes. This model was evaluated using data obtained on chlorpyrifos (water exposure), and provided accurate predictions. To extrapolate toxic effects from the individuals to the population level, a convenient approach is to use Individual-Based Models (IBMs) coupled to a bioenergetic dynamic model describing the physiological processes of the individuals (Dynamic Energy Budget theory). Accordingly, a DEB-IBM model was developed for describing the population dynamics of sticklebacks in artificial streams (mesocosms). The model predictions were compared to the data observed in a mesocosm experiment to assess the impacts of an endrocrine disruptor, the bisphenol A. The DEB-IBM provided great insight of the effects of Bisphenol A on the population dynamics. The mathematical models developed for sticklebacks coupled to the use of this fish in active biomonitoring strategy which integrate a multiFbiomarker approach highlight the strengths of the stickleback in environmental risk assessments

Application of a generic fish PBTK model for binary mixtures of chemicals

The integration of mechanistic approaches in Environmental risk assessment requires the integration of processes to move towards estimating internal dose from exposure or environmental concentrations (external dose) to predict toxicity in each taxa or the whole ecosystem. In this context, the overall objective of this work is to develop models to integrate TK data for environmental risk assessment of single and multiple chemicals. Three steps were defined to fulfil this objective: (i) Data collection of biological, physiological, and toxicological variables to calibrate and develop PBTK models, (ii) Development of PBTK models for environmental risk assessment of single chemicals, (iii) Development of PBTK models for environmental risk assessment of multiple chemicals. Generic PBTK models for single compounds in rainbow trout (Oncorrynchus mykiss), fathead minnow (Pimephales promelas), stickleback (Gastrosteus aculeatus) and zebrafish (Danio rerio) have been developed. Physiological description and parameters proposed by Nichols et al. [1] were updated by an extensive litterature search. New mathematical functions were proposed to integrate the main factors influencing the toxicokinetics (water temperature, growth dilution, reproduction cycle,…). Default values for compound-specific parameters were estimated by QSAR models based on hydrobycity [2, 3]. An optional interaction terms was added to the mixture PBTK models for metabolic interactions such as competitive inhibition. Two case studies were selected based on availability of toxicokinetic (TK) and toxicdynamic (TD) data for single compounds and for mixtures. In the first case study, the interaction between melamine and cyanuric acid was studied and in a second case study, the interaction between chlorpyrifos and permethrin was modelled. The models developped enable to model interactions that are observed between exposure concentrations and final effects. The QSAR estimations of certain compound-specific parameters can compensate for the lack of data in fish. Extrapolation from one species to another with the various models developed can also help bridge gaps. [1] Nichols et al. 1990. Toxicol Appl Pharmacol 106:433-447. [2] Bertelsen et al. 1998.. Environ Toxicol Chem 17:1447-1455. [3] Nichols et al. 2006. Aquat Toxicol 78:74-90