michel leconte - Profile on Academia.edu (original) (raw)

Papers by michel leconte

Remote Sensing, Aug 8, 2017

Spatial resolution is the main instrumental requirement for the multi-spectral optical space miss... more Spatial resolution is the main instrumental requirement for the multi-spectral optical space missions that address the scientific issues of marine coastal systems. This spatial resolution should be at least decametric. Aquatic color data processing associated with these environments requires specific atmospheric corrections (AC) suitable for the spectral characteristics of high spatial resolution sensors (HRS) as well as the high range of atmospheric and marine optical properties. The objective of the present study is to develop and demonstrate the potential of a ground-based AC approach adaptable to any HRS for regional monitoring and security of littoral systems. The in Situ-based Atmospheric CORrection (SACOR) algorithm is based on simulations provided by a Successive Order of Scattering code (SOS), which is constrained by a simple regional aerosol particle model (RAM). This RAM is defined from the mixture of a standard tropospheric and maritime aerosol type. The RAM is derived from the following two processes. The first process involved the analysis of a 6-year data set composed of aerosol optical and microphysical properties acquired through the ground-based PHOTONS/AERONET network located at Arcachon (France). The second process was related to aerosol climatology using the NOAA hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) model. Results show that aerosols have a bimodal particle size distribution regardless of the season and are mainly represented by a mixed coastal continental type. Furthermore, the results indicate that aerosols originate from both the Atlantic Ocean (53.6%) and Continental Europe (46.4%). Based on these results, absorbing biomass burning, urban-industrial and desert dust particles have not been considered although they represent on average 19% of the occurrences. This represents the main current limitation of the RAM. An assessment of the performances of SACOR is then performed by inter-comparing the water-leaving reflectance (ρ w ) retrievals with three different AC methods (ACOLITE, MACCS and 6SV using three different standard aerosol types) using match-ups (N = 8) composed of Landsat-8/Operational Land Imager (OLI) scenes and field radiometric measurements. Results indicate consistency with the SWIR-based ACOLITE method, which shows the best performance, except in the green channel where SACOR matches well with the in-situ data (relative error of 7%). In conclusion, the study demonstrates the high potential of the SACOR approach for the retrieval of ρ w . In the future, the method could be improved by using an adaptive aerosol model, which may select the most relevant local aerosol model following the origin of the atmospheric air mass, and could be applied to the latest HRS (Sentinel-2/MSI, SPOT6-7, Pleiades 1A-1B).

Identification des sources de contamination fécales en milieu côtier (IDFEC)

Techniques Sciences Méthodes, 2013

Une approche de Microbial Source Tracking dite culture- et collection-dependante a ete developpee... more Une approche de Microbial Source Tracking dite culture- et collection-dependante a ete developpee pendant 1 an pour faciliter l’identification des sources de pollution en cas d’episode de contamination fecale dans le bassin d’Arcachon (Gironde, France). Cette approche repose sur la comparaison d’une collection dite « environnementale » de genotypes obtenus dans des echantillons d’eau ou de sediment avec une collection dite « de reference » de genotypes provenant de matieres fecales d’origine connue (par exemple homme, animaux domestiques ou faune sauvage). La methode d’analyse consiste en l’isolement par culture sur milieu selectif d’indicateurs bacteriens de contamination fecale ( Escherichia coli et enterocoques fecaux) suivi d’un genotypage par Enterobacterial Repetitive Intragenic PCR (ERIC-PCR). Les caracteristiques genotypiques de chaque souche sont repertories dans une base de donnees.Pour E. coli , la base de donnees est constituee de 6 263 isolats obtenus a partir d’echantillons d’eau de mer ( n = 159), de sediments ( n = 119) et de feces d’animaux ou d’echantillons provenant de station d’epuration ( n = 169). La collection environnementale (3 565 isolats) contient 625 genotypes distinct dont 184, seulement, sont communs avec la collection de reference (2 698 isolats). Pour les enterocoques fecaux, elle est constituee de 3 941 isolats obtenus a partir d’echantillons d’eaux de mer ( n = 83), sediments ( n = 59) et feces d’animaux ou station d’epuration ( n = 128). La collection environnementale (2 013 isolats) represente 505 genotypes distincts dont seulement 137 sont communs avec la collection de reference (1 928 isolats). Seuls 29 % des 625 genotypes d’ E. coli et 27 % des 505 genotypes d’enterocoques fecaux etaient communs aux deux collections.L’analyse comparee des deux collections montre qu’une forte proportion de genotypes de la collection environnementale, 71 % pour E. coli et 73 % pour les enterocoques fecaux, n’ont ete detectes que dans l’eau ou les sediments. Cela peut suggerer l’existence d’une forte proportion de souches naturalisees.Des taux de classification correcte (ARCC) tres satisfaisants ont ete obtenus pour E. coli (65,2 %) et pour les enterocoques fecaux (ARCC = 88,7 %). De plus, nous avons pu confirmer l’origine aviaire d’une forte proportion d’isolats recueillis dans l’eau et les sediments d’un etang regulierement frequente par des canards colverts et des foulques macroules. Les valeurs d’ARCC et les resultants obtenus sur un site test valident la base de donnees constituee.

Bird Study, 2016

Capsule: Stable isotope analyses reveal some degree of migratory connectivity of Bluethroat popul... more Capsule: Stable isotope analyses reveal some degree of migratory connectivity of Bluethroat populations wintering from Iberia to West Africa. Aims: To identify the probable breeding origins of Bluethroats wintering from Iberia to Senegal. Methods: Bluethroat feathers (P1) were sampled from individuals at their wintering areas. These feathers were then analysed for stable H isotopes (δ 2 H). We assigned individual Bluethroats to approximate geographic origin using likelihood-based assignment procedures. Results: We observed spatial segregation between different Bluethroat populations. At wintering sites north of the Sahara Desert, Bluethroats wintering to the west came from further west origins than those which overwintered to the east. Bluethroats from central-eastern Europe overwintered either within the circum-Mediterranean region or in Senegal. We found no clear evidence supporting a sub-Saharan wintering range for birds breeding in Iberia (Luscinia svecica azuricollis subspecies). Conclusion: North of the Sahara Desert, we found what might be a parallel migration pattern. The apparent lack of Luscinia svecica namnetum Bluethroats in Senegal suggests to some extent some kind of leapfrog migration between some Luscinia svecica cyanecula populations and the L. s. namnetum subspecies.

L'étude de surveillance n° 37 du site électronucléaire du BLAYAIS (département de la Gironde) con... more L'étude de surveillance n° 37 du site électronucléaire du BLAYAIS (département de la Gironde) concerne la période d'avril à novembre 2014. Les domaines pélagique et benthique sont étudiés (physico-chimie, bathymétrie, hydrobiologie, bactériologie, zooplancton, macrofaune benthique).

Monitoring n° 32 of the BLAYAIS nuclear power plant takes into account studies conducted between ... more Monitoring n° 32 of the BLAYAIS nuclear power plant takes into account studies conducted between April and November 2009. Physicochemistry, Bathymetry, Hydrobiology, Bacteriology, Zooplankton, Benthic macrofauna, are reported.L'étude de surveillance n° 32 du site électronucléaire du BLAYAIS (département de la Gironde) concerne la période de avril à novembre 2009. Les domaines pélagique et benthique sont étudiés (physico-chimie, bathymétrie, hydrobiologie, bactériologie, zooplancton, macrofaune benthique)

Surveillance Ecologique du site du Blayais - année 2008

Ardeola, 2015

Understanding the migratory connectivity of migrant species is fundamental to their effective con... more Understanding the migratory connectivity of migrant species is fundamental to their effective conservation. Analysis of individual traits that can vary geographically, such as biometrics and stable isotopic values of tissues, can help establish migratory connections. The bluethroat Luscinia svecica is a species of conservation concern in Europe (Annex I Birds Directive). Our aim was to identify the possible migratory connectivity of bluethroats Luscinia svecica breeding in central and western Europe (subspecies L. s. namnetum, L. s. azuricollis and L. s. cyanecula in part) with their wintering areas

Surveillance écologique du site du Blayais. Année 1999

L'etude de surveillance n°22 du site electronucleaire du BLAYAIS (departement de la Gironde) ... more L'etude de surveillance n°22 du site electronucleaire du BLAYAIS (departement de la Gironde) conceme la periode d' avril a novembre 1996. le domaine pelagique est etudie (physico chimie, hydrobiologie, bacteriologie, zooplancton, bathymetrie). [Voir fiche resume p. 251-252]

Observatoire Aquitain des Sciences de l'Univers UMR 5805 EPOC Université Bordeaux 1 - CNRS

Estuarine, Coastal and Shelf Science, 2016

Thank you to the multiple faces of God revealed to me through the black women who have raised and... more Thank you to the multiple faces of God revealed to me through the black women who have raised and continuously supported me. To my late grandmother, uNomthandazo (a woman of prayer), ngiyabonga Gogo for your warrior spirit as it has inspired the woman I am still becoming. Thank you to my mother Sizakele Dube for gracefully answering the call to not only mother me but so many others. You are indeed "a mother of nations". Words truly fall short in the attempt to capture all that you have been to me. Thank you to my supervisors, Professor Pumla Gqola and Litheko Modisane for your untiring advice and support. Thank you for reminding me of my brilliance and endless potential, even when I least believed it. To Professor Bhekizizwe Peterson, thank you for giving "creative intellectual" a face to which I could look up to. Your passion for the arts and academia showed me that I didn't have to choose between the two. Instead, you challenged me to question those very spaces that my work in media collided with. To every young black person, you were the muse that helped me give birth to this research. To every hip-hop beat that comes into contact with mainstream media, you hold the potential to challenge hegemony. Thank you for refusing to be silenced. 5 Chapter One: An Introduction This research project investigates the representations of black 1 youth males in the reality television series, Running with the Reps, in order to understand ideas of black masculinity within hip-hop culture in South Africa. It does this by analyzing hip-hop culture elements such as language, music, style, and bodily disposition, as portrayed in the show. Running with the Reps is a reality television series based on the lives and personalities of a Johannesburg based dance crew of twelve black males between the ages of 17 and 25, known as The Repertoires/The Reps 2. The series originally aired on Vuzu TV from 4 March 2011 to 27 May 2011. Although The Reps consists of twelve members, only nine are cast as protagonists in the series. These are Nthato Malete, Larry "Larryngitis" Mncube-Nhlane, Michael "Mike" Makwala, Senhle "T-Chama" Mazibuko, TJ, Makhosini "The Thundacats" (this duo is made up of Thato and Kea, the youngest members in the group) as well as Tejee "DJ Ellipsis" Mbuyamba. Larry and Nthato are the leaders of the group who co-founded it in 2006 as an initiative to pioneer and promote hip-hop dancing as a career in South Africa. The show is centered on the lives of the dancers, as they share their careers, their personal lives, their business and their singular style, all in the pursuit of becoming a central entity within the South African commercial entertainment industry. Each episode follows the lives of The Reps as they task themselves with different entertainment projects, to get a step closer towards expanding their popularity as hiphop dancers and personalities. Each member speaks through the form of "diary entries" in front of the camera. This style of filming in reality television is often referred to as "fly on the wall" or "factual television" (Hill 2005: 2-7). This enables each of the individual members to become an active agent in documenting and telling 1 In order to distinguish between the various meanings of B/blackness in South Africa, I use 'black' (in lower caps) to refer to the demographic group sometimes referred to as racially African, as opposed to using 'Black' (upper caps) to refer to Black as defined under Black Consciousness-an antithesis to white racism that is a solid black unity that includes 'African', 'Indian' and 'coloured'. This distinction is made in order to make clear reference to the subjects of the chosen case study and the demographic in hip-hop, which they represent.

Surveillance Ecologique du site du Blayais, année 2010

Long-term changes of the zooplankton variability in a turbid environment: The Gironde estuary (France)

Estuarine, Coastal and Shelf Science, 2005

Zooplanktonic variability at the maximum turbidity zone was investigated for the Gironde estuary ... more Zooplanktonic variability at the maximum turbidity zone was investigated for the Gironde estuary for 18 years. This ecosystem is characterized by a high concentration of suspended matter and five dominant zooplankton species: the copepods Eurytemora affinis, Acartia bifilosa, A. tonsa and the mysids Neomysis integer and Mesopodopsis slabberi. Four major sources of variation in density were analyzed: (a) spatial variation

Ecological Indicators, 2008

This study deals with the application of macrozoobenthos-based biotic indices (BI) within the fra... more This study deals with the application of macrozoobenthos-based biotic indices (BI) within the frame of the implementation of the European Water Framework Directive. More precisely, this study aimed at assessing the performance of five recently developed methodologies (BI) for the assessment of ecological quality status (EcoQ) in two semi-enclosed, sheltered coastal ecosystems and in one transitional water body situated along the Western French coast, namely Marennes-Oléron Bay, Arcachon Bay, and the Seine Estuary. This study showed that these five indices rarely agreed with each other, describing very different pictures of the overall EcoQ of the three study sites. This work also clearly underlined the limitations of these approaches, notably the dependency of most of these BI and the resulting EcoQ classifications on habitat characteristics, more particularly to natural levels of sediment silt-clay content and the location of stations in the subtidal or the intertidal. The implication of our observations concerning the use of these BI for implementation of the WFD is discussed in terms of definition of habitat-specific reference conditions and necessity to adjust thresholds to the particular habitat occurring in semi-enclosed ecosystems. Meanwhile, the unmodified use of these BI severely impaired accurate assessment of EcoQ and decision-making on the managers' point of view.

Journal of Animal Ecology

1. Currently, the deployment of tracking devices is one of the most frequently used approaches to... more 1. Currently, the deployment of tracking devices is one of the most frequently used approaches to study movement ecology of birds. Recent miniaturisation of light-level geolocators enabled studying small bird species whose migratory patterns were widely unknown. However, geolocators may reduce vital rates in tagged birds and may bias obtained movement data. 2. There is a need for a thorough assessment of the potential tag effects on small birds, as previous meta-analyses did not evaluate unpublished data and impact of multiple life-history traits, focused mainly on large species and the number of published studies tagging small birds has increased substantially. 3. We quantitatively reviewed 549 records extracted from 74 published and 48 unpublished studies on over 7,800 tagged and 17,800 control individuals to examine the effects of geolocator tagging on small bird species (body mass <100 g). We calculated the effect of tagging on apparent survival, condition, phenology and breeding performance and identified the most important predictors of the magnitude of effect sizes. 4. Even though the effects were not statistically significant in phylogenetically controlled models, we found a weak negative impact of geolocators on apparent survival. The negative effect on apparent survival was stronger with increasing relative load of the device and with geolocators attached using elastic harnesses. Moreover, tagging effects were stronger in smaller species. 5. In conclusion, we found a weak effect on apparent survival of tagged birds and managed to pinpoint key aspects and drivers of tagging effects. We provide recommendations for Accepted Article This article is protected by copyright. All rights reserved. establishing matched control group for proper effect size assessment in future studies and outline various aspects of tagging that need further investigation. Finally, our results encourage further use of geolocators on small bird species but the ethical aspects and scientific benefits should always be considered.