Michel Grimaldi

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The impact of soil cover organization on the forest community has been studied in a 19-ha tract at Piste de St Elie station in French Guiana. 195 species each represented by at least 10 individuals were chosen from records of the position, diameter at breast height (dbh) and precise identification by botanical sampling of 12104 ligneous plants (dbh ≥ 10(More)
The aim of the study is to improve our understanding of the vertical and lateral variations in the mercury content [Hg] of tropical soils. In addition to the distance to anthropogenic sources of Hg, the most frequently evoked determining factor is the abundance of Hg-bearing phases. Soil processes (weathering, mass or water transfer) determine the abundance(More)
This study compared soil physical, chemical, and biological characteristics between natural grassland and recently abandoned rice fields in order to identify those variables that might explain the observed increase of Camponotus punctulatus anthills in abandoned rice paddy fields from Northern Argentina. Mainly due to a reduction of macropores and(More)
Distribution and Dynamic of Gibbsite and Kaolinite in an Oxisol of Serra do Mar, southeastern Brazil Sônia Furian Depto de Geografia – USP-FFLCH Cidade universitaria C.P. 8105, Cep: 05508-900 Sao Paulo – SP, Brazil Laurent Barbiéro IRD, Laboratoire des Mécanismes de Transfert en Géologie, 39, Allées Jules Guesde, 31000 Toulouse, France René Boulet IRD,(More)
The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and(More)
Landscape dynamics result from forestry and farming practices, both of which are expected to have diverse impacts on ecosystem services (ES). In this study, we investigated this general statement for regulating and supporting services via an assessment of ecosystem functions: climate regulation via carbon sequestration in soil and plant biomass, water cycle(More)
Total mercury (HgT) and monomethylmercury (MMHg) were investigated in a tropical head watershed (1 km(2)) of French Guiana. The watershed includes a pristine area on the hill slopes and a former gold mined flat in the bottomland. Concentrations of dissolved and particulate HgT and MMHg were measured in rain, throughfall, soil water and at three points along(More)
In this paper, an efficient unsupervised approach for extracting objects from maritime background using solely still video images is proposed. Its main idea is that maritime background (sea) has the main particularity of absorbing only hot light frequencies (red and green), while an object has not this property. Therefore if a timely vector of class(More)
This paper describes a novel approach for rigid object segmentation from a dynamic background using a pre-recorded video with a moving camera, and we apply it to the problem of vessel segmentation in a maritime video scene. The difficulty of modeling background appearance or/and dynamic, modeling object appearance, and compensating camera motion renders(More)
This article addresses the problem of near real time video analysis of a maritime scene using a (moving) airborne RGB video camera in the goal of detecting and eventually recognizing a target maritime vessel. This is a very challenging problem mainly due to the high level of uncertainty of a maritime scene including a dynamic and noisy background, camera's(More)