Détection des plantes envahissantes par télédétection : un cas d'étude,l'ambroisie en région Rhône‐Alpes,France

L'ambroisie, Ambrosia artemisiifolia, est une plante annuelle responsable d'allergies respiratoires dues à son pollen. Dans certains secteurs du département du Rhône, jusqu'à 20% de la population a été atteinte d'allergie respiratoire en 2005. Ce problème majeur de santé touche actuellement six des huit départements de la Région Rhône‐Alpes (Ain, Ardèche, Drôme, Isère, Loire et Rhône). L'un de nos objectifs est de mettre au point une méthode qui permette de cartographier, dans un premier temps à l'échelle d'une commune, puis à terme à l'échelle d'un département l'infestation par l'ambroisie. En se basant sur les méthodes développées par Auda et al. (2002a Auda, Y., Blasco, F., Gastellu, J.‐P., Marty, G. and Dechamp, C. 2002a. Essai préliminaire de détection des champs d'Ambroisie (Ambrosia artemisiifolia) par télédétection spatiale.. Revue française d'allergologie et d'immunologie clinique, 42: 533–538.  [Google Scholar]), nous avons inventorié, à la fin juillet, l'infestation par l'ambroisie dans la commune d'Estrablin (Isère). Pour chaque parcelle inventoriée, le type de culture et l'importance de l'infestation ont été enregistrés dans un Système d'Information Géographique. Les parcelles échantillonnées couvrent 3650 km², soit 30% de la surface de la commune. Ces données serviront à valider une image multispectrale Spot 5 du 16 août 2005. L'interprétation des données terrain souligne l'importance de l'infestation. En effet, 93% des surfaces échantillonnées sont infestées. L'analyse se poursuit par une classification par le maximum de vraisemblance de l'image Spot 5 qui repose sur une thématique croisant le type de culture et l'importance de l'infestation. Le pourcentage de pixels bien classés (45%), la logique des confusions observées et la cohérence visuelle des représentations cartographiques des résultats témoignent de l'efficacité de la méthode de détection des zones infestées. La performance de cette méthode apparaît largement tributaire de la disponibilité d'images de bonne qualité au moment adéquat. Son caractère opérationnel qui est donc étroitement lié à ces contraintes techniques, est discuté en fonction des programmes des Agences Spatiales.

Ragweed, Ambrosia artemisiifolia, is an annual plant, the pollen of which is responsible for respiratory allergies. In 2005, these allergies affected up to 20% of the population in parts of the department of Rhône. This is a major health problem for six of the eight departments of the Rhône‐Alpes region (Ain, Ardèche, Drôme, Isère, Loire and Rhône). Our objective was to validate a method to map ragweed infestation in a village and then to extend this experiment to a department. Using methods developed by Auda et al. (2002a Auda, Y., Blasco, F., Gastellu, J.‐P., Marty, G. and Dechamp, C. 2002a. Essai préliminaire de détection des champs d'Ambroisie (Ambrosia artemisiifolia) par télédétection spatiale.. Revue française d'allergologie et d'immunologie clinique, 42: 533–538.  [Google Scholar]), we undertook a survey of ragweed infestation at the end of July 2005 in the village of Estrablin (Isère). Plots of land were registered in a Geographical Information System, with indications of crop type and ragweed infestation included in each plot. The sample area covered 3650 km² and constituted 30% of the total area of the village. The data were used to validate a SPOT 5 multispectral satellite image captured on 16 August 2005. Analysis of the ground data confirmed the extent of the ragweed infestation. More than 90% of the sample area was found to be infested. The image processing was based on crossing the crop type with the degree of infestation, using maximum likelihood classification. The accuracy of the method of detection used was demonstrated by the percentage of correctly classified pixels (45%), the reasons for confusion and the clarity of the visual representations. The success of our approach is highly influenced by the availability of high‐quality images. Its feasibility, which is linked therefore to technical constraints, is examined in relation to space agency programmes.     

Novel chlorhexidine dermal patches,preparation characterization and antimicrobial evaluation

Polymer Bulletin - The purpose of this work is to develop chlorhexidine dermal patches using Eudragit® RL100 as the patch forming polymer. Solvent casting technique was employed in the...     

Validation of a Value Management Approach Developed for the Saudi Public Sector

A VM （value management） approach was developed that better suits the culture and the context of the SPS （Saudi Public Sector）. This approach provided a comprehensive assessment of VM at institutional, organizational and project levels. This paper illustrates the procedures that were used to validate the developed VM approach. For the institutional and organizational levels, the VM approach was validated by conducting telephone interviews with three experts from three organizations that use VM and with two senior managers from the MOF （Ministry of Finance）. Mainly, it was found that the MOF should be supported by experts to set up a centre of excellence that can set VM policy, guidelines and standards for the promotion of VM in the SPS, in order to ensure achieving value for money spent in SPS projects. The developed VM approach, as it would be applied at the project level, was presented to 11 experts, all of whom completed a validation questionnaire and presented their comments. Subsequently, the questionnaires were analyzed and the VM approach was amended to reflect the inputs provided by these experts. It was concluded that VM should be applied at least twice on SPS projects. Firstly, it is to review and structure strategic and project briefs to sort out soft issues, and secondly, it is to optimize project designs and sort out hard issues.     

Characteristic modes for a slot in a conducting plane, TM case

Consider an infinitely long slot in a conducting plane in an unbounded medium illuminated by a uniform transverse magnetic (TM) (to the slot axis) plane wave. The theory of characteristic modes for apertures is applied to solve the problem. For a narrow slot, analytic expressions for the first two characteristic currents and the equivalent magnetic current are given. As computed by the method of moments, numerical results for the characteristic currents and fields, the equivalent magnetic current, and the transmitted field pattern are presented for the slot whose width is one wavelength.     

Selective tumor heating by shortwave radiofrequency (RF)

Experimental solid tumors were treated in vivo with external high frequency dielectric heating to observe any heat selectivity between the tumor mass on one hand, and the subcutaneous tissue, muscle, and systemic temperatures on the other. Methylcholantrene-induced sarcoma cells were inoculated into the subcutaneous tissue or muscles of the posterior thigh of isologous Fischer rats. When the tumor mass reached the desired size, dielectric heating with a fixed frequency of 13.56 megahertz (MHz) was applied locally to the tumor-bearing area. All the periods of treatment were kept constant at 1 hour. Temperature was measured with thermocouple probes inserted directly into the tumor mass and the tissues lying within the electromagnetic field. Systemic temperature was monitored via a clinical mercury thermometer inserted into the rectum. Temperature recordings were taken at 5-minute intervals during which time the power was turned off in order to avoid the RF interference and to allow thermal equilibrium between the probes and the tissue. The results showed a high selective temperature gradient for the tumor mass as compared to the subcutaneous and muscle tissues when tumor masses were greater than 1.0 cu cm. No selectivity was detected in small tumors or in nontumor-bearing controls. Systemic temperature did not rise by these treatments. No tumor regression was observed at this dosage. Burns were noted in those animals in which normal tissue temperature rose above 43 C.     

Electromagnetic field of a rectangular patch of uniform and lineardistributions of current

Closed-form expressions for a class of indefinite double integrals are presented. Using these formulas, exact analytical expressions for the magnetic vector potential and the electric and magnetic fields of a rectangular patch of uniform and linear distributions of electric current in an unbounded homogeneous medium are derived. The field expressions obtained are valid everywhere, in particular in the source region. Computed results verifying the correctness and accuracy of these expressions are presented     

Anti‐biofilm and anti‐virulence effects of silica oxide nanoparticle–conjugation of lectin purified from Pseudomonas aeruginosa

Pseudomonas aeruginosa lectin is purified and nanoparticle‐conjugated in an attempt to inhibit biofilm formation. Thirteen (23.6%) P. aeruginosa isolates are obtained from chicken meat samples, of which 30.8% are biofilm producers and 69.2% are lectin producers. Lectin is purified 36.8‐fold to final specific activity of 506.9 U/mg. Four nanoparticle types are prepared via laser ablation: platinum (Pt), gold (Au), silica oxide (SiO₂), and tin oxide (SnO₂). The four types are characterised, and pulse feeding is used to conjugate the lectin and nanoparticles. Pt, Au, SiO_2, and SnO₂ nanoparticles inhibit biofilm formation, especially SiO₂ nanoparticles, which have higher effectiveness when conjugated with purified lectin. SiO₂‐conjugated lectin significantly (p < 0.05) inhibits biofilm formation more effectively than control and other nanoparticle‐conjugated lectins. Au‐, Pt nanoparticle‐, and SnO₂‐conjugated lectins inhibit biofilm significantly compared with control (p < 0.05), and rhlR gene expression is decreased in the presence of SiO₂‐conjugated lectin. Furthermore, lectin and Pt, Au, SiO₂ and SnO₂ nanoparticles separately, and their conjugated lectins, are effective biofilm inhibitors. Of these, SiO₂‐conjugated lectin was most significant as an anti‐biofilm. Moreover, virulence factors regulon and RhlR were reduced by SiO₂‐conjugated lectin, indicating that this conjugation may also decrease the virulence of P. aeruginosa.     

CMNN: Cooperative Modular Neural Networks

A new cooperative modular neural network (CMNN) architecture for classification is introduced. The main idea is to decrease partial over- and under-learning by dealing with different levels of overlap in separate modules. Motivated by some basic biological modular-networks’ concepts, CMNN proposes a new cooperation scheme to integrate the information available at its modules. Cooperative modules utilize some voting techniques to come up with a collective decision. Moreover, the specialization concept is proposed as a solution for high overlap regions in the input space. A number of experiments which assess CMNN’s capabilities are outlined. The experiments compare it to several non-modular and modular state-of-the-art alternatives using several benchmark problems. The proposed modularization scheme proves to be an effective way to deal with the complexities of real classification problems.     

Characteristic modes for slots in a conducting plane, TE case

Consider an infinitely long slot in a perfectly conducting plane in an unbounded medium illuminated by a uniform transverse electric (TE) (to the slot axis) plane wave. The theory of characteristic modes for apertures is applied to solve the problem. For a narrow slot, analytic expressions for the first two characteristic currents and the equivalent magnetic current are given. As computed by the method of moments, numerical results for the characteristic currents and fields, the equivalent magnetic current, and the transmitted field pattern are presented for the slot whose width is one wavelength.