« Vimers de mer » et sociétés littorales entre Loire et Gironde (XIVe-XVIe siècle)

En moyen français des provinces de l’Ouest, un « vimer de mer » désigne une forte tempête avec ou sans submersion marine. C’est à partir des xive-xvie siècles que les premières mentions de vimers ayant touché la côte atlantique entre Loire et Gironde peuvent être collectées dans divers fonds, des comptes seigneuriaux, des cartulaires, des mémoriaux, etc. Leur recension impose une approche critique rigoureuse. Plusieurs submersions, en 1351-1352 (?), 1509-1510, 1518, 1598 ont été de vraies catastrophes. Face à la menace d’inondation, les populations littorales dressent des chaussées, des levées en terre ou des « bots ». Elles épousent le danger et l’intègrent dans leur mode de vie.In the middle French language through the western provinces, a “vimer de mer” means a storm with or without coastal flooding. It’s from the fourteenth – sixteenth centuries that first mentions of “vimers” hit the Atlantic coast between the Loire and Gironde can be gleaned from various archives, such as seigneurial accounts, cartularies, daybooks etc. A critical approach is needed in collecting storms reported from such miscellaneous sources. Several real disasters occurred in1351-1352 (?), 1509-1510, 1518, 1598. In the face of flooding threat, costal communities draw up levees, sea walls, embankments or “bots”. They embrace the danger and include it in their way of life

Assessing development strategies and Africa's food and nutrition security

"On average, a typical developing country in Africa is assisted by about 30 aid institutions in the implementation of development strategies, yet Africa is still far from achieving food and nutrition security. Adequate access to food that is necessary for food security must be complemented with provision of health services, education, sanitary environments, and safe water sources, among other resources, to achieve nutrition security." from TextDevelopment assistance ,Food security Africa ,Nutrition Security ,Health services ,Water quality ,Sanitation ,Development strategies ,

Development strategies and food and nutrition security in Africa: an assessment

"Momentum is building in and around Africa today for policy action to decisively confront hunger and malnutrition. If we are to succeed, it is vital that food and nutrition security strategies be both sound and able to be implemented. Ultimately, strategies deficient in either of these two areas will be ineffectual. Lessons from past strategies provide a valuable resource in the design of future strategies, yet there is a dearth of programmatic information and rigorous evaluations of the approaches used in the past. With this in mind, the authors of this 2020 discussion paper review the multitude of approaches and strategies for achieving food and nutrition security in Africa within the context of development over the past four decades. They assess the extent to which these plans have been implemented and identify the key constraints and limitations, along with the priority investments needed for more effective design and implementation in the future." Foreword by Joachim von Braun, Director General, IFPRIFood policy, Hunger, Malnutrition Africa, Food security Africa, Development policies, Assessment, Investments,

Programme PROPPAC : hydrologie, nutrients, chlorophylle et zooplancton des campagnes SURTROPAC 07 à 13 (1987-1989)

Ce recueil présente les données de sels nutritifs, oxygène dissous, chlorophylle et zooplancton obtenues deux fois par an lors de la radiale SURTROPAC, de 20°S à 10°N le long 165°E. Les campagnes couvrent la période comprise entre janvier 1987 (SURTROPAC 07) et décembre 1989 (SURTROPAC 13). Les données sont présentées sous forme de coupes 20°S - 10°N et sous forme de tableaux. (Résumé d'auteur

Simulation and analysis of exotic non-specular phenomena

Le journal, Open Access, demande à ce qu'on ne dépose pas d'exemplaire du papier sur un autre serveur. https://www.jeos.org/index.php/jeos_rp/article/view/10025International audienceWhen coupled modes are excited in a multilayered structure, the profile of the reflected beam presents exotic characteristics like unexpectedly large lateral shifts or beam enlargment. These results are surprising because they are not accounted for by classical approaches (Artmann's formula or Tamir's description of the reflected beam's profile). Studying such situations requires reliable numerical tools - that is why our programmes are published with this paper. Such tools can be used to understand the behaviour of any multi-layered structure

Assessment of vanadium distribution in shallow groundwaters

International audienceShallow groundwater samples (filtered at 0.2 μm) collected from a catchment in Western France (Petit Hermitage catchment) were analyzed for their major- and trace-element concentrations (Fe, Mn, V, Th and U) as well as their dissolved organic carbon (DOC) concentrations, with the aim to investigate the controlling factors of vanadium (V) distribution. Two spatially distinct water types were previously recognized in this catchment based on variations of the rare earth element (REE) concentrations. These include: (i) DOC-poor groundwater flowing below the hillslope domains; this type has low V contents; and (ii) DOC-rich groundwater originating from wetlands, close to the river network; the latter water type displays much higher V concentrations. The temporal variation of the V concentration was also assessed in the wetland waters; the results show a marked increase in the V content at the winter-spring transition, along with variations in the redox potential, and DOC, Fe and Mn contents. In order to allow the study of organo-colloidal control on V partitioning in water samples, ultrafiltration experiments were performed at different pore size cut-offs (30 kDa, 10 kDa and 5 kDa). Two shallow, circumneutral waters were sampled: one was both DOC- and Fe-rich and the other was DOC-rich and Fe-poor. In terms of major- and trace-cations and DOC concentrations, the data were processed using an ascendant hierarchical classification method. This revealed the presence of two main groups: (i) a "truly" dissolved group (Na, K, Rb, Ca, Mg, Ba, Sr, Si, Mn, Co, Ni, Cr, Zn and Ni), and (ii) a colloidal group carrying DOC, Fe, Al, Pb, Cu, REE, U, Th and V. Vanadium has an unpredictable behavior; it can be either in the organic pool or in the inorganic pool, depending on the sample. Moreover, V speciation calculations--using Model VI and SCAMP--were performed on both samples. Speciation modeling showed approximately the same partitioning feature of these elements as compared to ultrafiltration data, namely: a slight change of the V speciation in groundwaters along the studied topographic sequence. This implies that vanadium in hillslope groundwater wells occurs as a mixing of organic and inorganic complexes, whereas V in wetland groundwater wells comprises mainly organic species. Using the dataset described above, factors such as aquifer-rock composition or anthropogenic input were demonstrated to probably play a minor role in determining the V distribution in shallow groundwaters. Although an anthropogenic impact can be ruled out at this local scale, we cannot preclude a perturbation in the global V cycle. Most likely, the two dominant factors involved are the organic matter content and the redox state either promoting competition with Fe-, Mn-oxides as V carriers in groundwater or not. In this context, it appears challenging to determine whether organic matter or redox-sensitive phases are the major V carriers involved, and a further study should be dedicated to clarify this partition, notably to address the processes affecting large-scale V transport

Does As(III) interact with Fe(II), Fe(III) and organic matter through ternary complexes?

International audienceUp until now, only a small number of studies have been dedicated to the binding processes of As(III) with organic matter (OM) via ionic Fe(III) bridges; none was interested in Fe (II). Complexation isotherms were carried out with As(III), Fe(II) or Fe(III) and Leonardite humic acid (HA). Although PHREEQC/Model VI, implemented with OM thiol groups, reproduced the experimental datasets with Fe(III), the poor fit between the experimental and modeled Fe(II) data suggested another binding mechanism for As(III) to OM. PHREEQC/Model VI was modified to take various possible As(III)-Fe(II)-OM ternary complex conformations into account. The complexation of As(III) as a mononuclear bidentate complex to a bidentate Fe(II)-HA complex was evidenced. However, the model needed to be improved since the distribution of the bidentate sites appeared to be unrealistic with regards to the published XAS data. In the presence of Fe(III), As(III) was bound to thiol groups which are more competitive with regards to the low density of formed Fe(III)-HA complexes. Based on the new data and previously published results, we propose a general scheme describing the various As(III)-Fe-MO complexes that are able to form in Fe and OM-rich waters