Using Feature Modelling and Automations to Select among Cloud Solutions

International audienceCloud computing is a major trend in distributed computing environments. Resources are accessed on demand by customers and are delivered as services by cloud providers in a pay-per-use model. Companies provide their applications as services and rely on cloud providers to provision, host and manage such applications on top of their infrastructure. However, the wide range of cloud solutions and the lack of knowledge in this domain is a real problem for companies when facing the cloud solution choice. In this paper, we propose to use Software Product Line Engineering (SPLE) and Feature Model (FM) configuration to develop a decision-supporting tool. Using such modelling techniques and automations, this tool takes into consideration the application technical requirements as well as the user quality requirements to provide an accurate result among cloud solutions that best fits both requirements

Influence of Microbial Symbionts on Plant–Insect Interactions

International audienceThere is growing evidence that microorganisms are important ‘hidden players’ in insect–plant interactions. Insect symbionts can directly affect these interactions by providing insects with key nutrients or by interfering with the plant to modulate food provisioning to insects and plant defences. Insect symbionts can also have indirect cascading ecological consequences at the community level through insect- and plant-mediated effects that include their impact on insect reproduction, on natural enemies of herbivores or on plant-associated microorganisms. Identification of symbiotic communities associated with insects, characterization of transmission and acquisition patterns as well as understanding of molecular mechanisms underlying these plant–insect–microbe interactions have important ecological and evolutionary consequences. This review highlights the excitement that surrounds these investigations and the promise they hold for a better understanding of the functional, ecological and evolutionary impacts of symbionts on plant–insect interactions, with implications and relevance for both applied and fundamental researches

Le travail collectif dans les établissements scolaires : quête ou déni ?

Ce texte présente la première étape d’une recherche de terrain sur les « réseaux ambition réussite » en France, dont la prescription reconfigure à la fois l’organisation et le contenu du travail des protagonistes : chef d’établissement, inspecteur territorial et « professeurs référents ». Pour rendre compte des rapports entre l’organisation, l’encadrement et les activités des professeurs, cet article utilise une démarche ergonomique qui confronte, à travers des entretiens et des observations, les professionnalités supposées acquises et mobilisées par ces personnels dans des collectifs de travail. Il montre dans une première partie les limites des connaissances scientifiques disponibles (sur l’établissement, les chefs d’établissement, le corps d’inspection, le travail des enseignants en classe) pour rendre compte des « nouveaux » rapports professionnels. Il montre, dans une seconde partie, comment cette nouvelle reconfiguration, n'appelle pas une réorganisation du travail collectif et empêche le développement d’une activité organisationnelle (collective et individuelle), quotidiennement déployée de façon invisible dans le cadre du fonctionnement ordinaire de l’établissement. Les conséquences, en termes de santé au travail, sont discutées dans une dernière partie.This paper presents the first part of on the field research into "successful ambition networks" in France, whose prescription reconfigures both the organisation and content of the work of those involved: head teachers, inspectors and tutors. To show the relationships between the organisation, supervision and activities of teachers, this paper presents an ergonomic approach which confronts, through interviews and observations, the supposedly acquired professional conduct of this personnel in work collectives. In the first part it shows the limits of scientific knowledge available (in the school, head teachers, inspectors, the work of teachers in the classroom) to highlight "new" work relationships. In the second part it shows how this new reconfiguration, which does not require collective work to be reorganised, prevents the development of an organisational activity (collective and individual), deployed in the everyday running of schools. The consequences, in terms of occupational health, are discussed in the final part.Este texto presenta la primera etapa de una investigación sobre el terreno, referente a las “redes ambición y éxito” en Francia, cuya prescripción reconfigura tanto la organización como el contenido del trabajo de los protagonistas : jefe de establecimiento, inspección territorial y “profesores referentes”. Para tener en cuenta las relaciones entre la organización, los mandos y las actividades de los profesores, este artículo presenta un procedimiento ergonómico que compara, a través de entrevistas y de observaciones, las profesionalidades que se suponen adquiridas y movilizadas por estas personas en los colectivos de trabajo. Muestra en una primera parte los limites de los conocimientos científicos disponibles (sobre el establecimiento, los jefes de establecimiento, los cuerpos de inspección, el trabajo de los profesores en la clase) para rendir cuentas de las “nuevas” relaciones profesionales. En una segunda parte muestra cómo esta nueva reconfiguración, que no exige una reorganización del trabajo colectivo, impide el desarrollo de una actividad organizativa (colectiva e individual), diariamente desplegada de manera invisible en el marco del funcionamiento corriente del establecimiento. Las consecuencias, en términos de salud laboral, se debaten en una última parte

Using Feature Modelling and Automations to Select among Cloud Solutions

International audienceCloud computing is a major trend in distributed computing environments. Resources are accessed on demand by customers and are delivered as services by cloud providers in a pay-per-use model. Companies provide their applications as services and rely on cloud providers to provision, host and manage such applications on top of their infrastructure. However, the wide range of cloud solutions and the lack of knowledge in this domain is a real problem for companies when facing the cloud solution choice. In this paper, we propose to use Software Product Line Engineering (SPLE) and Feature Model (FM) configuration to develop a decision-supporting tool. Using such modelling techniques and automations, this tool takes into consideration the application technical requirements as well as the user quality requirements to provide an accurate result among cloud solutions that best fits both requirements

Molecular characterization of genetic diversity within the Africa/Middle East/Asia Minor and Sub-Saharan African groups of the Bemisia tabaci species complex

International audienceBemisia tabaci Gennadius is a major plant pest in many agricultural systems worldwide. It is a complex of cryptic species that differ in many ecological respects, including damage-causing potential. Monitoring the genetic composition of B. tabaci populations in the field is, therefore, essential for achieving effective control. Sequencing is costly and time consuming; thus, efficient diagnostic tools must be developed to perform epidemiological studies involving hundreds of individuals. Here, we describe a polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method for identifying all the putative species comprising the Africa/Middle East/Asia Minor group, including those that are the most devastating crop pests. Moreover, intra-specific diversity associated with specific symbiotic bacteria known to manipulate insect host phenotypes can also be detected. In addition, this method discriminates between the Africa/Middle East/Asia Minor and the Sub-Saharan African groups, which are sympatric in some areas. This simple, reliable and cost-effective diagnostic tool is ideal for the rapid analysis of a high number of individuals and, thus, has potential applications in field contexts, where it could provide valuable baseline information for pest management programs

Susceptibility of MED-Q1 and MED-Q3 Biotypes of Bemisia tabaci (Hemiptera: Aleyrodidae) Populations to Essential and Seed Oils

International audienceBemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of many agricultural and ornamental crops in tropical and subtropical regions causing damages that result in important economic losses. Insecticides are commonly used in greenhouses or fields to control B. tabaci populations leading to rapid evolution of resistance that render treatments inefficient. Therefore, and for environmental and human health concerns, other approaches must be developed for this pest management. In the present study, we compare, using the leaf dip method, the toxicity of three essential oils (Cymbopogon citratus, Ocimum americanum, and Hyptis spicigera) and three seed oils (Lannea microcarpa, Lannea acida, and Carapa procera) with three chemical insecticides (acetamiprid, deltamethrin, and chlorpyrifos-ethyl) on adults. Two B. tabaci biotypes (MED-Q1 and MED-Q3) belonging to the Mediterranean species and collected in Burkina Faso were used. Essential oils were analyzed by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. We showed that these two biotypes have different levels of resistance to the three insecticides, MED-Q3 being more sensitive than MED-Q1. Moreover, they differ in the frequency of resistance alleles to insecticides, especially for organo-phosphates, as these alleles are almost fixed in MED-Q1. On the other hand, the two biotypes prove to be more susceptible to the plant extracts than to insecticides except for chlorpyrifos-ethyl, with essential oils that showed the highest insecticidal activities. Monoterpenes content were the most abundant and showed the highest insecticidal activities. Our results indicated that essential oils, but also seed oils, have the potential to constitute an alternative strategy of pest management

Evidence of diversity and recombination in Arsenophonus symbionts of the Bemisia tabaci species complex

<p>Abstract</p> <p>Background</p> <p>Maternally inherited bacterial symbionts infecting arthropods have major implications on host ecology and evolution. Among them, the genus <it>Arsenophonus</it> is particularly characterized by a large host spectrum and a wide range of symbiotic relationships (from mutualism to parasitism), making it a good model to study the evolution of host-symbiont associations. However, few data are available on the diversity and distribution of <it>Arsenophonus</it> within host lineages. Here, we propose a survey on <it>Arsenophonus</it> diversity in whitefly species (Hemiptera), in particular the <it>Bemisia tabaci</it> species complex. This polyphagous insect pest is composed of genetic groups that differ in many ecological aspects. They harbor specific bacterial communities, among them several lineages of <it>Arsenophonus</it>, enabling a study of the evolutionary history of these bacteria at a fine host taxonomic level, in association to host geographical range and ecology.</p> <p>Results</p> <p>Among 152 individuals, our analysis identified 19 allelic profiles and 6 phylogenetic groups, demonstrating this bacterium's high diversity. These groups, based on <it>Arsenophonus</it> phylogeny, correlated with <it>B. tabaci</it> genetic groups with two exceptions reflecting horizontal transfers<it>.</it> None of three genes analyzed provided evidence of intragenic recombination, but intergenic recombination events were detected. A mutation inducing a STOP codon on one gene in a strain infecting one <it>B. tabaci</it> genetic group was also found. Phylogenetic analyses of the three concatenated loci revealed the existence of two clades of <it>Arsenophonus.</it> One, composed of strains found in other Hemiptera, could be the ancestral clade in whiteflies. The other, which regroups strains found in Hymenoptera and Diptera, may have been acquired more recently by whiteflies through lateral transfers.</p> <p>Conclusions</p> <p>This analysis of the genus <it>Arsenophonus</it> revealed a diversity within the <it>B. tabaci</it> species complex which resembles that reported on the larger scale of insect taxonomy. We also provide evidence for recombination events within the <it>Arsenophonus</it> genome and horizontal transmission of strains among insect taxa. This work provides further insight into the evolution of the <it>Arsenophonus</it> genome, the infection dynamics of this bacterium and its influence on its insect host's ecology.</p

Abundance of Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) and its parasitoids on vegetables and cassava plants in Burkina Faso (West Africa)

International audienceThe whitefly Bemisia tabaci is a pest of many agricultural and ornamental crops worldwide and particularly in Africa. It is a complex of cryptic species, which is extremely polyphagous with hundreds of host plants identified around the world. Previous surveys in western Africa indicated the presence of two biotypes of the invasive MED species (MED-Q1 and MED-Q3) living in sympatry with the African species SSA and ASL. This situation constitutes one of the rare cases of local coexistence of various genetic entities within the B. tabaci complex. In order to study the dynamics of the distribution and abundance of genetic entities within this community and to identify potential factors that could contribute to coexistence, we sampled B. tabaci populations in Burkina Faso in 2015 and 2016 on various plants, and also their parasitoids. All four genetic entities were still recorded, indicating no exclusion of local species by the MED species. While B. tabaci individuals were found on 55 plant species belonging to eighteen (18) families showing the high polyphagy of this pest, some species/ biotypes exhibited higher specificity. Two parasitoid species (Eretmocerus mundus and Encarsia vandrieschei) were also recorded with E. mundus being predominant in most localities and on most plants. Our data indicated that whitefly abundance, diversity , and rate of parasitism varied according to areas, plants, and years, but that parasitism rate was globally highly correlated with whitefly abundance suggesting density dependence. Our results also suggest dynamic variation in the local diversity of B. tabaci species/biotypes from 1 year to the other, specifically with MED-Q1 and ASL species. This work provides relevant information on the nature of plant-B. tabaci-parasitoid interactions in West Africa and identifies that coexistence might be stabilized by niche differentiation for some genetic entities. However, MED-Q1 and ASL show extensive niche overlap, which could ultimately lead to competitive exclusion