122 research outputs found
Mapping natural habitats using remote sensing and Sparse partial least square discriminant analysis
This work presents a novel approach for mapping the spatial distribution of natural habitats in the "Foothills of Larzac" Natura 2000 listed site located in a French Mediterranean Biogeographical Region. Sparse Partial Least Square Discriminant Analysis was used to analyze two RapidEye datasets (June 2009 and July 2010) with the purpose of choosing the most informative spectral, textural and thematic variables that allow discriminating the classes of habitats. The Sparse Partial Least Square Discriminant Analysis selected relevant and stable variables for the discrimination of habitat classes that could be linked to ecological or biophysical characteristics. It also gave insight into the similarities and the differences between habitats classes with comparable physiognomic characteristics. The highest user accuracy was obtained for dry improved grasslands (u=91.97%) followed by riparian ash woods (u= 88.38%). These results are very encouraging given that these two classes were identified in Annex 1 of the EC Habitats Directive as of community interest. Due to limited data input requirements and to its computational efficiency, the approach developed in this paper is a good alternative to other types of variable selection approaches in a supervised classification framework and can be easily transferred to other Natura 2000 sites
Exploring high repetitivity remote sensing time series for mapping and monitoring natural habitats ; A new approach combining OBIA and k-partite graphs
International audienc
Engineered arrays of NV color centers in diamond based on implantation of CN- molecules through nanoapertures
We report a versatile method to engineer arrays of nitrogen-vacancy (NV)
color centers in dia- mond at the nanoscale. The defects were produced in
parallel by ion implantation through 80 nm diameter apertures patterned using
electron beam lithography in a PMMA layer deposited on a diamond surface. The
implantation was performed with CN- molecules which increased the NV defect
formation yield. This method could enable the realization of a solid-state
coupled-spin array and could be used for positioning an optically active NV
center on a photonic microstructure.Comment: 12 pages, 3 figure
Theory of channel simulation and bounds for private communication
We review recent results on the simulation of quantum channels, the reduction of adaptive protocols (teleportation stretching), and the derivation of converse bounds for quantum and private communication, as established in PLOB [Pirandola, Laurenza, Ottaviani, Banchi, arXiv:1510.08863]. We start by introducing a general weak converse bound for private communication based on the relative entropy of entanglement. We discuss how combining this bound with channel simulation and teleportation stretching, PLOB established the two-way quantum and private capacities of several fundamental channels, including the bosonic lossy channel. We then provide a rigorous proof of the strong converse property of these bounds by adopting a correct use of the Braunstein-Kimble teleportation protocol for the simulation of bosonic Gaussian channels. This analysis provides a full justification of claims presented in the follow-up paper WTB [Wilde, Tomamichel, Berta, arXiv:1602.08898] whose upper bounds for Gaussian channels would be otherwise infinitely large. Besides clarifying contributions in the area of channel simulation and protocol reduction, we also present some generalizations of the tools to other entanglement measures and novel results on the maximum excess noise which is tolerable in quantum key distribution
Varying Herbivore Population Structure Correlates with Lack of Local Adaptation in a Geographic Variable Plant-Herbivore Interaction
Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid moth Utetheisa ornatrix to its host plant, the pyrrolizidine alkaloid-bearing legume Crotalaria pallida, at the continental scale, but found no differentiation at the regional scale. In the present study, we sampled the same sites to investigate factors that may contribute to the lack of differentiation at the regional scale. We performed field observations that show that specialist and non-specialist polyphagous herbivore incidence varies among populations at both scales. With a series of common-garden experiments we show that some plant traits that may affect herbivory (pyrrolizidine alkaloids and extrafloral nectaries) vary at the regional scale, while other traits (trichomes and nitrogen content) just vary at the continental scale. These results, combined with our previous evidence for plant population differentiation based on larval performance on fresh fruits, suggest that U. ornatrix is subjected to divergent selection even at the regional scale. Finally, with a microsatellite study we investigated population structure of U. ornatrix. We found that population structure is not stable over time: we found population differentiation at the regional scale in the first year of sampling, but not in the second year. Unstable population structure of the herbivore is the most likely cause of the lack of regional adaptation
Construction d'un indicateur d'altération des berges lacustres. Protocole d'échantillonnage. Rapport d'étape
[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASARECe document propose une méthode de caractérisation dans le but de construire un indicateur d'altération des berges lacustres. Cette méthode se base sur une photo-interprétation associée à des relevés de terrain. Elle consiste à réaliser une cartographie fine des altérations de berges sur le pourtour du plan d'eau. Ce protocole est issu d'études menées sur le bassin test d'Adour-Garonne suite à la signature d'une convention de partenariat avec l'Agence de l'ea
Capacités et limites de la télédétection pour cartographier les habitats naturels
Ce document constitue une synthĂšse bibliographique portant sur l'utilisation de la tĂ©lĂ©dĂ©tection afin de cartographier la diversitĂ© de la vĂ©gĂ©tation et distribution spatiale des habitats naturels et semi-naturels. L'hĂ©tĂ©rogĂ©nĂ©itĂ© des capteurs de tĂ©lĂ©dĂ©tection utilisĂ©s dans ces Ă©tudes et la panoplie des mĂ©thodes dĂ©veloppĂ©es pour l'analyse des donnĂ©es font parfois obstacle Ă la comprĂ©hension de ce qui peut ĂȘtre rĂ©alisable avec les outils actuels de tĂ©lĂ©dĂ©tection. Le but de ce document est de fournir une synthĂšse technique sur ce qui est actuellement envisageable en termes de dĂ©tection dâhabitats et dâĂ©valuation de leur Ă©tat de conservation
Capacités et limites de la télédétection pour la cartographie des habitats naturels : revue de littérature
Remote sensing tools can contribute to a better understanding of the diversity of natural and semi-naturals habitats, their spatial distribution and their conservation status. These elements are part of the European obligations imposed by the habitats directive (Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora). Several European projects (MS. MONINA, SPIN, Habistat, etc.) and a large number of scientific studies have addressed the issue of mapping European natural habitats via remote sensing and then deriving indicators on their conservation status (a total of 337 references). The plenty of varying remote sensing sensors used in these studies and the panoply of methods developed for data analysis impede the understanding of what is possibly achievable with the current remote sensing technologies. The aim of this document is to provide a technical synthesis on what is currently feasible in terms of detection of natural and semi-natural habitats and the assessment of their conservation status. The purpose is to uncover the potential of remote sensing coupled with Geographic Information Systems (GIS) for understanding the distribution of habitats in Europe. The term âremote sensingâ is used here to indicate the more advanced, computer-assisted analytical tools for information extraction from satellite or airborne imagery. Thus, we speciïŹcally exclude the purely visual interpretation of aerial photographs or other (analogue or digital) images. Given the large number of habitats of community interest listed in Annex 1 of the habitats directive, only broad habitat categories are addressed in this synthesis, namely forests, grasslands, heathland and wetlands. The document is structured into 5 chapters: âąChapter 1 gives a synopsis of European broad habitat categories with some supporting numbers and facts on their total coverage and their conservation status. âąChapter 2 provides basic concepts on remote sensing sensors and the main types of image processing methods used for the extraction of information from remote sensing data. This chapter also defines the main characteristics of remote sensing that are relevant for studying natural and semi-natural habitats and that must be selected at an early stage before conducting an analysis based on remote sensing data. âąChapter 3 includes an overview of the main methodological frameworks for information extraction from remote sensing data. âąChapter 4 is the core chapter of this document where each category of broad habitat is analyzed in terms of parameters that can be derived as a function of the remote sensing sensor and the classification method. âąChapter 5 concludes this document with a list of recommendations derived from the previous chapters on the exploitation of remote sensing data for the analysis of natural and semi-natural habitats. The recommendations are made for input data requirements (remote sensing and in-situ data) and on the best practices for a more effective use of remote sensing in the monitoring of habitats and protected areas
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