Littérature scientifique sur le sujet « Communities structuration »

Whereas literature in the area of open innovation considerably advances the understanding of innovation community mechanics, little is known about how innovation communities need to be anchored within organizations to unleash the creative potential of employees. To contribute to this discussion, this article focuses on the still understudied link among organizational integration and its influence on innovation activities and outcomes of corporate innovation communities. Additionally, it identifies distinct types of transition strategies to anchor organizational integration of corporate innovation communities. To attain this aim structuration theory is applied. Multiple in-depth case studies allow insights into antecedents of and transition strategies for corporate innovation communities. Results demonstrate that 1) cultural and structural integration are major antecedents for innovation activities and outcomes of corporate innovation communities, and 2) transition strategies offer valuable patterns to alter organizational integration.

Kerinci Seblat National Park in Bengkulu, Indonesia, was gazetted by the Indonesian government, and its overlaps with forests occupied by most indigenous communities made their farming activities in the area illegal. People were prohibited from accessing and expanding their farming areas in the national park, threatening their livelihoods. The livelihood diversity index (LDI) and livelihood asset index (LAI) were used to explore the livelihood systems of these communities. This study also examines the effect of livelihood assets on livelihood diversity and analyzes livelihood strategy choices using Giddens’ structuration theory. A quantitative survey combined with in-depth interviews was conducted in two villages with different land types: wetlands (rice fields) and drylands (farmlands). This study found that the communities diversified their livelihoods into eight types of livelihood strategies. Almost all livelihood indicators were different, and the differences in livelihood asset indicators affected the LDI. As a process of structuration, communities have diversified their livelihoods into farm (e.g., annual and perennial crops), off-farm (e.g., farm wages), and non-farm (e.g., services and government transfer) activities. Rural households have modified their social and physical structures to secure their livelihoods by optimizing agricultural intensification technologies or by seeking non-agricultural income. Households decide whether to specialize or diversify their livelihoods based on factors such as the area of cultivated land, number of crops cultivated, distance of the farming location from the house, total household income, non-farm income, and reciprocal relationships.

This paper aims at responding to the need for specific management of virtual entities. It proposes a flexible process based on Functional Analysis and Adaptive Structuration Theory, called Virtual Entities Management Support (VEMS). Starting from environmental requirements analysis, the method helps to choose functions, attitudes, and tools based on a strategic vision in three dimensions: the virtual entity value addition, the members' satisfaction, and the entity flexible frontiers. It leverages the powerful concept of adjacent individuals and adjacent communities inside the 3-D model. The full process is detailed and applied to five virtual entities inside and outside the industry. It raised a common view of 21 best attitudes. The paper provides managerial guidelines to managers of virtual entities.

Plant parasitic nematodes are highly abundant in all agrosystems and some species can have a major impact on crop yields. To avoid the use of chemical agents and to find alternative methods to manage these pests, research studies have mainly focused on plant resistance genes and biocontrol methods involving host plants or natural enemies. A specific alternative method may consist in supporting non-damaging indigenous species that could compete with damaging introduced species to decrease and keep their abundance at low level. For this purpose, knowledge about the biodiversity, structure and functioning of these indigenous communities is needed in order to carry out better risk assessments and to develop possible future management strategies. Here, we investigated 35 root crop fields in eight regions over two consecutive years. The aims were to describe plant parasitic nematode diversity and to assess the potential effects of cultivation practices and environmental variables on communities. Community biodiversity included 10 taxa of plant parasitic nematodes. Despite no significant abundance variations between the two sampling years, structures of communities varied among the different regions. Metadata collected for the past six years, characterizing the cultural practices and soils properties, made it possible to evaluate the impact of these variables both on the whole community and on each taxon separately. Our results suggest that, at a large scale, many variables drive the structuration of the communities. Soil variables, but also rainfall, explain the population density variations among the geographical areas. The effect of the variables differed among the taxa, but fields with few herbicide applications and being pH neutral with low heavy metal and nitrogen concentrations had the highest plant parasitic nematode densities. We discuss how these variables can affect nematode communities either directly or indirectly. These types of studies can help to better understand the variables driving the nematode communities structuration in order to support the abundance of indigenous non-damaging communities that could compete with the invasive species.

Several parties continue to criticize the empowerment of remote tribal or indigenous communities. The empowerment program for remote indigenous communities has not yet been deemed effective for empowering indigenous communities. Using Anthony Giddens’ structuration theory, this study aims to examine how communication is structured in community empowerment activities for isolated tribes. Using a case study methodology, this study uses qualitative descriptive approach. Interviews were conducted with the Regional Leader of ‘Aisyiyah (PDA) Banggai, who empowered an isolated tribe in the interior of Tombiobong, Maleo Jaya village, South Batui sub-district, Banggai district, Central Sulawesi (Sulteng). The study indicates that social reproduction occurs through the duality of structures in Aisyiyah empowerment activities among the indigenous Loinang people. This fits with Giddens’s idea of duality, which says that structure and agent work together and affect each other.

This paper examines the rapid and ad hoc development and interactions of participative citizen communities during acute events, using the examples of the 2011 floods in Queensland, Australia, and the global controversy surrounding Wikileaks and its spokesman, Julian Assange. The self-organising community responses to such events which can be observed in these cases bypass or leapfrog, at least temporarily, most organisational or administrative hurdles which may otherwise frustrate the establishment of online communities; they fast-track the processes of community development and structuration. By understanding them as a form of rapid prototyping, e-democracy initiatives can draw important lessons from observing the community activities around such acute events.

Background Mobile health platforms can facilitate social support and address HIV (human immunodeficiency virus) stigma but pose challenges for intervention design and participant engagement. Giddens’s structuration theory, that individuals are shaped by—and shape—their communities through rules and resources that give them power to operate within these environments, provides a useful analytic framework for exploring these dynamic intervention spaces. Method Data were drawn from an online randomized controlled trial intervention (HealthMpowerment) for young Black men who have sex with men to reduce condomless anal intercourse. We applied a conversational analysis informed by structuration theory to 65 user-generated conversations that included stigma content. We aimed to understand how the interdependent relationship between the intervention space and participants’ contributions might contribute to behavior change. Results Thirty five intervention participants contributed to the analyzed conversations. Our analysis identified three types of conversational processes that may underlie behavior change: (1) Through intervention engagement, participants established norms and expectations that shaped their discussions; (2) participants used anecdotes and anonymity to reinforce norms; and (3) intervention staff members sought to improve engagement and build knowledge by initiating discussions and correcting misinformation, thus playing an integral role in the online community. Conclusions The lens of structuration theory usefully reveals potential behavior change mechanisms within the social interactions of an online intervention. Future design of these interventions to address HIV stigma should explicitly characterize the context in which individuals (study staff and participants) engage with one another in order to assess whether these processes are associated with improved intervention outcomes.

Communication of disseminating stakeholder messages through dramatization aims to improve the economy and people's welfare. This article aims to examine how symbolic convergence in the tourism sector can create social change in the Selo Tirto Giri Tourism Object, Gresik Regency. This study uses the theory of symbolic convergence from Bormann and the theory of structuration from Gidden. This research method uses a qualitative descriptive method with a single case study. The informants of this research were village stakeholders who were determined purposively. Data validity uses source triangulation. Data analysis uses fantasy theme analysis where fantasy messages become the unit of analysis Lindlof and Taylor. The results of the study show that the dramatization of messages is created through fantasy themes, namely awareness of developing regions, getting along in harmony, and prosperous and independent communities. Symbolic convergence is related to the structuration that occurs symbolically in Sekapuk Village. The existence of repeated messages creates a dimension of public awareness that shapes the structure and creates social change. The process of dramatizing messages and structuring forms the tourist attraction of Selo Tirto Giri so that Sekapuk Village, which is a poor village, becomes a Millionaire Village.

Abstract Motivation We present Link-HD, an approach to integrate multiple datasets. Link-HD is a generalization of ‘Structuration des Tableaux A Trois Indices de la Statistique–Analyse Conjointe de Tableaux’, a family of methods designed to integrate information from heterogeneous data. Here, we extend the classical approach to deal with broader datasets (e.g. compositional data), methods for variable selection and taxon-set enrichment analysis. Results The methodology is demonstrated by integrating rumen microbial communities from cows for which methane yield (CH4y) was individually measured. Our approach reproduces the significant link between rumen microbiota structure and CH4 emission. When analyzing the TARA’s ocean data, Link-HD replicates published results, highlighting the relevance of temperature with members of phyla Proteobacteria on the structure and functionality of this ecosystem. Availability and implementation The source code, examples and a complete manual are freely available in GitHub https://github.com/lauzingaretti/LinkHD and in Bioconductor https://bioconductor.org/packages/release/bioc/html/LinkHD.html.

‘The commons’ is a concept originating from the traditional shared use of land, but which now often refers to any social asset, physical or abstract, that is shared. This research concerns one aspect of the commons, namely the knowledge commons. The thesis explores community roles in developing and sustaining cultural institutions as key components of the knowledge commons. It focuses particularly on processes of participatory design, and on the capacity of digital technologies to support community engagement. The study takes place across the cultural contexts of the State of Victoria (Australia) and Singapore. The three key aims of the thesis are to explore in what ways and to what extent: I. The emerging concept of the knowledge commons relates to the role of cultural institutions as systems for the creation and sharing of sustainable knowledge resources by their communities. II. The notion of participative design may be applicable to the ongoing development of such systems as multi-stakeholder partnerships to meet community needs. III. Differences in national culture may affect the generality of such an analysis. The research design employs literature analysis and multiple case studies as a basis for proposing new theorisations and an analytical tool to assist future action by cultural institutions and relevant communities. The main perspective used in framing the literature analysis and case studies is Giddens’ structuration theory. Structuration sees the continuing interplay between social action and social structure as the means by which the cultural patternings known as institutions are recursively produced. A complementary perspective used is Hofstede’s model of cultural dimensions. Other theorists from a range of disciplines provide perspectives on particular concepts or aspects, such as the commons and participatory design. Five chapters are headed ‘Foundations’. These seek to explicate key dimensions of the research, namely the knowledge commons, community knowledge, cultural institutions, participatory design, and the cultural contexts of Victoria and Singapore. Four chapters are headed ‘Case Study’ and deal with individual cultural institutions, or clusters of institutions, which were the sites of exploratory enquiry (generally consisting of interviews and observation, but in the case of Museum Victoria also elements of action research). The cultural institutions covered by these chapters are Museum Victoria/Women on Farms Gathering, the Asian Civilisations Museum, Public Libraries in Victoria and Public Libraries in Singapore. These insights are analysed to propose a series of related typologies. The coverage of these typologies includes resource characteristics, collective processes, and cultural dimensions. The typologies come together as components of an integrated, explanatory conceptual model concerning the relationships between the commons, cultural institutions, communities, collective processes (including the role of information and communication technologies) and participatory design within cultural institutions. In the final chapter answers are formulated for the initiating research questions. Also the integrated model developed by the thesis is used as the basis for a proposed analytical tool to assist action towards enhanced community engagement in the development of cultural institutions. Use of the tool is illustrated by application to several examples of collective action encountered during the research.

L’objectif général de cette thèse est de déterminer le rôle de l’exclusion compétitive, du filtrage environnemental et des limites de dispersion dans la distribution des espèces de fourmis de la litière en forêt guyanaise. Pour cela, nous avons évalué comment la diversité des assemblages de fourmis varie le long de gradients environnementaux et géographiques, en considérant les trois facettes de la diversité (i.e. taxonomique, phylogénétique et fonctionnelle) à différentes échelles spatiales. Des patrons observés de structure fonctionnelle et phylogénétique plus faibles qu’attendus au hasard suggèrent que le filtrage environnemental agit sur la distribution des espèces à l’échelle du site de récolte. En revanche, l’hypothèse d’une sur-dispersion fonctionnelle et/ou phylogénétique entre espèces qui co-occurrent localement résultant de l’exclusion d’espèces similaires n’est pas soutenue par nos résultats. A l’échelle régionale, nos résultats montrent que les communautés de fourmis sont fortement structurées par les variations environnementales. La distance spatiale influence également la distribution des espèces de fourmis à travers la région. D’après l’ensemble de nos résultats, le filtrage environnemental est la force majeure de structuration des assemblages d’espèces de fourmis en forêt guyanaise, tant à l’échelle locale qu’à l’échelle régionale. Les espèces sont réparties de manière fragmentaire sur le territoire, en réponse aux variations environnementales. Les patrons de diversité sont également influencés par la distance spatiale à l’échelle régionale, résultant en un turnover dans la composition spécifique des assemblages de fourmis entre localités éloignées
The overall aim of this thesis is to determine the role of competitive exclusion, environmental filtering and dispersal limitation on the distribution of leaf-litter ant species in French Guianese forest. To this end, we evaluated how the diversity of ant communities varies along environmental and geographic gradients, using the three facets of diversity (i.e. taxonomic, phylogenetic and functional dimensions) at different spatial scales. Observed patterns of functional and phylogenetic structure lower than expected by chance suggest that environmental filtering acts on the distribution of ant species at the scale of sampled site. In contrast, the hypothesis of functional and/or phylogenetic overdispersion between locally co-occurring species resulting from the exclusion of similar species is not supported by our results. At the regional scale, our results show that ant communities are strongly structured by environmental variations. Spatial distance also influences the distribution of ant species throughout the region. Taken together, our results suggest that environmental filtering is the main driver structuring communities of ant species in French Guianese rainforest, both at local and regional scales. Species are distributed in a patchy way throughout the region, in response to environmental variations. Patterns of diversity are also influenced by the spatial distance at the regional scale, leading to a turnover in species composition of ant communities between distant areas

La couche limite planétaire est la couche atmosphérique la plus basse qui est en interaction directe et constante avec les surfaces terrestres et marines sur lesquelles se concentrent les activités humaines, les cultures et divers écosystèmes. Comprendre l’origine de sa composition à la fois chimique et microbiologique est fondamental dans notre étude approfondie de la biosphère. Alors que les microorganismes de la couche limite planétaire – retrouvés jusqu’à 106 cellules par mètre cube d’air – semblent varier significativement à l’échelle spatiale et temporelle en termes de concentration et de diversité, ils restent largement méconnus. L’objectif principal de cette thèse est de comprendre comment se structurent les communautés microbiennes dans la troposphère, et en particulier dans la couche limite planétaire, ainsi que d’identifier les facteurs de contrôle majeurs. En travaillant sur des échantillons collectés pendant plusieurs semaines sur neuf sites répartis sur la planète, et en utilisant les technologies de séquençage ADN haut-débit, nous avons étudié la composition taxonomique et fonctionnelle des communautés microbiennes de la phase gazeuse et solide de l’atmosphère (c’est-à-dire non associés aux nuages).Nos premiers résultats sur la taxonomie des communautés microbiennes révèlent que les surfaces proches des sites sont les contributeurs principaux de distribution des communautés microbiennes atmosphériques, malgré l’occurrence potentielle du transport longue-distance des microorganismes atmosphériques. Egalement, les conditions météorologiques combinées à la diversité des surfaces locales terrestres ou océaniques jouent un rôle important dans la variation temporelle de la structure des communautés microbiennes de la couche limite planétaire. Une deuxième étude nous a permis d’étudier davantage la variation temporelle des communautés microbiennes atmosphériques sur un site continental montagneux en France (1465 m d’altitude) sur une année complète. Cette étude révèle l’importance des conditions de surface des paysages aux alentours dans la composition taxonomique des communautés atmosphériques. L’évolution au cours de l’année des terres agricoles et de la végétation, qui composaient en majeure partie le paysage du site, était responsable du changement temporel observé dans la composition taxonomique des communautés microbiennes atmosphériques. Finalement, nous avons étudié la composition fonctionnelle des communautés microbiennes de la couche limite planétaire afin d’identifier si les conditions physiques et chimiques de l’atmosphère jouaient un rôle dans la sélection ou adaptation microbienne des microorganismes atmosphériques. L’analyse comparative de données métagénomiques ne révèle pas de signature atmosphérique spécifique du potentiel fonctionnel des communautés microbiennes atmosphériques. La composition fonctionnelle semble avant tout liée aux écosystèmes locaux. Toutefois, nous avons observé que les champignons étaient plus dominants relativement aux bactéries dans l’air comparativement aux autres écosystèmes. Ce résultat suggère un processus de sélection des champignons durant l’aérosolisation et/ou le transport aérien. Les champignons pourraient survivre davantage l’aérosolisation et le transport aérien comparativement aux bactéries du fait de leur résistance naturelle aux conditions physiques stressantes de l’atmosphère. Nos résultats ont apporté une meilleure compréhension des facteurs déterminants (c’est-à-dire les surfaces locales, les sources distantes, les conditions météorologiques locales, les conditions physiques stressantes de l’atmosphère) et de leur contribution dans la structuration des communautés microbiennes de la couche limite atmosphérique. Nos investigations constituent une base importante pour de nouvelles études sur la prévision et le contrôle des communautés microbiennes atmosphériques, afin de répondre à des questions majeures dans les domaines de la santé publique et de l’agronomie
Up to 106 microbial cells per cubic meter are found in suspension in the planetary boundary layer, the lowest part of the atmosphere. Direct influences of the planetary boundary layer on humans, crops and diverse ecosystems like soils and oceans make the full understanding of its composition, both chemical and microbiological, of utmost importance. While microbial communities of the planetary boundary layer vary significantly at different temporal and spatial scales, they remain largely unexplored. The main goal of this thesis was to understand how airborne microbial communities are structured in the troposphere with special emphasis on the planetary boundary layer and to identify their main controlling factors. We investigated both the taxonomic and functional composition of airborne microbial communities in the dry phase (i.e. not cloud-associated) over time at nine different geographical sites around the world using high throughput sequencing technologies.Our investigation that focused on microbial taxonomy showed that local landscapes were the main contributors to the global distribution of airborne microbial communities despite the potential occurrence of long-range transport of airborne microorganisms. We also observed that meteorology and the diversity of the surrounding landscapes played major roles in the temporal variation of the microbial community structure in the planetary boundary layer. We further explored the temporal variation of airborne microbial communities at a continental and mountainous site in France (1465 m above sea level) over a full-year. This study demonstrated the importance of the surface conditions (i.e. vegetation, snow cover etc.) of the surrounding landscapes on the taxonomic composition of airborne microorganisms. The seasonal changes in agricultural and vegetated areas, which represented a significant part of the site’s surrounding landscape, were correlated to the shifts in the taxonomic composition of airborne microbial communities during the year. Finally, we investigated the functional composition of microbial communities of the planetary boundary layer to identify whether the physical and chemical conditions of the atmosphere played a role in selection or microbial adaptation of airborne microorganisms. The comparative metagenomic analysis did not show a specific atmospheric signature in the functional potential of airborne microbial communities. To the contrary, their functional composition was mainly correlated to the underlying ecosystems. However, we also showed that fungi were more dominant relatively to bacteria in air as compared to other (planetary bound) ecosystems. This result suggested a selective process for fungi during aerosolization and/or aerial transport and that fungi might likely survive aerosolization and/or aerial transport better than bacteria due to their innate resistance to stressful physical conditions (i.e. UV radiation, desiccation etc.). Our results provide a clearer understanding of the factors (i.e. surrounding landscapes, distant sources, local meteorology, and stressful physical atmospheric conditions) that control the distribution of microbial communities in the atmospheric boundary layer. Our investigations provide a basis for further studies on the prediction and even control of airborne microbial communities that would be of interest for public health and agriculture

Les Coccinellidae, dont le régime alimentaire polyphage inclut la prédation d'insectes Hémiptères phytophages ont suscité de multiples tentatives d'acclimatation pour réguler divers ravageurs. Les psylles, bien qu'étant des proies alternatives ou essentielles, est un régime alimentaire beaucoup plus rare et donc bien moins étudié, Obrycki & Kring (1998) ont rapporté que seulement 10% des introductions intentionnelles ont conduit à un succès d’invasion. Ce faible taux d'acclimatation, conjugué aux risques écologiques associés à l'introduction d'espèces exotiques souligne la nécessité d'une évaluation rigoureuse avant toute introduction planifiée pour le contrôle biologique.L’objectif de cette thèse est d'examiner le processus d'acclimatation des coccinelles sur des îles tropicales, en se concentrant spécifiquement sur les espèces psylliphages.Le premier axe est consacré à une méta-analyse des données historiques relatives aux espèces de coccinelles dans des environnements insulaires tropicaux. Cette étude a pour but de délimiter les traits spécifiques des espèces et les caractéristiques des îles qui influencent la présence et l’établissement des espèces de coccinelles, indigènes ou introduites, dans le contexte de la lutte biologique. Une analyse des données de présence sur 86 îles tropicales réparties dans 11 archipels, ainsi que des données morphologiques et écologiques de 250 espèces de coccinelles, a révélé que les espèces indigènes des îles sont principalement aphidiphages et coccidiphages, mais de petite taille. Cela implique souvent l’introduction délibérée d’espèces plus grandes et donc plus voraces pour la lutte biologique. Toutefois, les espèces de plus petite taille présentent un taux de succès d’établissement significativement supérieur. Le deuxième axe se focalise sur la composition et la structuration des communautés de coccinelles psylliphages en milieu insulaire tropical, La Réunion. Il cherche à identifier les espèces qui se regroupent autour des psylles et celles qui utilisent ces insectes comme ressource alimentaire primaire. Cet axe permet de déterminer les facteurs paysagers, climatiques et de disponibilité des proies qui influencent ces assemblages. Un échantillonnage de 11 sites, deux plantes hôte, Leucaena leucocephala et Acacia heterophylla, de deux espèces de psylles, respectivement Heteropsylla cubana et Acizzia uncatoides a été mené sur deux saisons estivales. A La Réunion, 14 des 28 espèces de coccinelles présentes exploitent la ressource en psylles mais seulement trois l’utilise comme ressource essentielle ou alternative : une polyphage indigène : Exochomus laeviusculus ; une aphidiphage exotique : Coccinella septempunctata et une psylliphage exotique : Olla v-nigrum. Le troisième axe analyse les interactions de prédation intraguildes au sein des communautés de coccinelles psylliphages, avec une attention portée à Harmonia conformis et aux trois autres espèces utilisant les psylles comme ressource essentielle ou alternative déterminées dans le deuxième axe. Cette étude vise à caractériser la symétrie, la direction et l'intensité des interactions de prédation intraguildes parmi ces taxons. Des adultes de Harmonia conformis ont été confrontés à des œufs des trois espèces psylliphages présentes à La Réunion et des adultes de ces trois espèces ont été confrontés à des œufs de Harmonia conformis. Les 4 espèces sont des prédateurs intraguildes seules les espèces de taille équivalente ont une relation symétrique d’intensité modérée. Harmonia conformis montre une relation de prédation intraguilde asymétrique envers la Exochomus laeviusculus. Les conclusions tirées de ces trois axes de recherche sur l'évaluation du potentiel invasif et les interactions intraguildes au sein des communautés psylliphages fourniront des indicateurs clés pour évaluer la faisabilité de la lutte biologique par coccinelles en milieu insulaire tropical
The Coccinellidae, whose polyphagous diet includes preying on phytophagous Hemiptera insects, have prompted numerous attempts at acclimatization to regulate various pests. Psyllids, though serving as alternative or essential prey, represent a much rarer diet and thus are less studied; Obrycki & Kring (1998) reported that only 10% of intentional introductions led to successful invasions. This low acclimatization rate, coupled with the ecological risks associated with the introduction of exotic species, underscores the necessity for a rigorous evaluation before any planned introduction for biological control.The objective of this thesis is to examine the acclimatization process of ladybugs on tropical islands, focusing specifically on psyllid-eating species.The first part is dedicated to a meta-analysis of historical data related to ladybug species in tropical island environments. This study aims to delineate the specific traits of the species and the characteristics of the islands that influence the presence and establishment of both indigenous and introduced ladybug species in the context of biological control. An analysis of presence data from 86 tropical islands across 11 archipelagos, as well as morphological and ecological data from 250 ladybug species, revealed that native island species are mainly aphidophagous and coccidophagous but small in size. This often necessitates the deliberate introduction of larger, more voracious species for biological control. However, smaller species show a significantly higher establishment success rate.The second part focuses on the composition and structure of psyllid-eating ladybug communities in a tropical island environment, Réunion Island. It seeks to identify the species that cluster around psyllids and those that use these insects as a primary food resource. This section helps determine the landscape, climatic, and prey availability factors influencing these assemblies. Sampling at 11 sites, involving two host plants, Leucaena leucocephala and Acacia heterophylla, and two psyllid species, respectively Heteropsylla cubana and Acizzia uncatoides, was conducted over two summer seasons. On Réunion Island, 14 out of 28 ladybug species exploit the psyllid resource, but only three use it as an essential or alternative resource: a native polyphage, Exochomus laeviusculus; an exotic aphidophagous, Coccinella septempunctata; and an exotic psyllidophagous, Olla v-nigrum.The third part analyzes the intraguild predation interactions within the psyllid-eating ladybug communities, with a focus on Harmonia conformis and the three other species determined in the second part that use psyllids as an essential or alternative resource. This study aims to characterize the symmetry, direction, and intensity of intraguild predation interactions among these taxa. Adults of Harmonia conformis were confronted with eggs from the three present psyllid-eating species on Réunion Island, and adults from these three species were confronted with eggs of Harmonia conformis. The four species are intraguild predators; only species of equivalent size have a symmetric relationship of moderate intensity. Harmonia conformis shows an asymmetric intraguild predation relationship towards Exochomus laeviusculus.The conclusions drawn from these three research areas on evaluating invasive potential and intraguild interactions within psyllidophagous communities will provide key indicators for assessing the feasibility of biological control by ladybugs in a tropical island environment

Les micro-organismes jouent un rôle essentiel dans le fonctionnement des écosystèmes forestiers. L’ensemble de ces micro-organismes associés aux racines est appelé « microbiote racinaire » et est connu pour promouvoir la croissance de l’arbre, améliorer sa résistance face aux stress biotiques et abiotiques et participer au cycle des nutriments. Étudier les facteurs de structuration et de régulation du microbiote racinaire est essentiel pour mieux comprendre les mécanismes impliqués dans les interactions arbres/micro-organismes et le rôle du microbiote racinaire de l’arbre en réaction aux contraintes environnementales actuelles et futures. Au cours de ma thèse, j’ai étudié la dynamique de colonisation des racines du peuplier gris par les communautés bactériennes et fongiques du sol en combinant approches métagénomique et microscopique. Parallèlement, une étude réalisée en mésocosme a été menée afin de connaître l’impact du génotype de l’hôte et des facteurs environnementaux tels que le climat et le type de sol sur le microbiote racinaire du peuplier noir, espèce colonisant les écosystèmes ripisylves et particulièrement touchée par le changement climatique. Enfin, par des approches de métagénomique et de métabolomique, j’ai étudié, d’une part, l’impact des variations du microbiote du sol et, d’autre part, celui de la voie de signalisation de l’acide jasmonique, sur le métabolome et les communautés du microbiote racinaire du peuplier gris. L’ensemble de mes résultats met en lumière l’impact significatif de l’arbre et des facteurs environnementaux sur la composition et la structure taxonomique et fonctionnelle du microbiote racinaire ainsi que la nécessité de considérer l’arbre et son microbiote comme un « méta-organisme » à part entière
Microorganisms play an essential role in the functioning of forest ecosystems. The pool of the root- associated microorganisms is called “root microbiome” and is known to promote tree growth, improve tree resistance to biotic and abiotic stresses and participate in nutrient cycling. Studying the factors that structure and regulate the root microbiome is essential to better understand the mechanisms involved in tree-microorganism interactions and the role of the tree root microbiome in response to current and future environmental constraints. During my thesis, I studied the colonization dynamic of grey poplar roots by bacterial and fungal communities in the soil by combining metagenomic and microscopic approaches. In parallel, a mesocosm study was carried out to determine the impact of the host genotype and environmental factors such as climate and soil type on the root microbiome of black poplar, a species that colonizes riparian ecosystems and is particularly affected by climate change. Finally, through metagenomic and metabolomic approaches, I studied, on the one hand, the impact of soil microbiome variations and, on the other hand, the signalling pathway of jasmonic acid, a phytohormone involved in defence, on the metabolome and communities of the root microbiome of grey poplar. The results of my thesis highlight the significant impact of the tree and environmental factors on the composition and taxonomic and functional structure of the root microbiome as well as the need to consider the tree and its microbiota as a "meta-organism" in its own right

Les rivières en tresses sont des grandes rivières alluviales de piémont montagneux à forte dynamique spatio-temporelle et à géomorphologie particulière. Leur cours traverse alternativement de vastes plaines et des rétrécissements de vallées ou canyons. Cette géomorphologie influence fortement les échanges d’eau entre la rivière avec sa nappe souterraine et sur l’épaisseur sédimentaire. Les échanges d’eau entre la rivière et sa nappe se produisent à différentes échelles allant de la vallée jusqu’à des bancs de graviers et peuvent créer des filtres biotiques et abiotiques qui influencent les communautés d’invertébrés. Les canyons créent des zones de moindre épaisseur sédimentaire voire d’absence de sédiments et peuvent représenter de fortes barrières à la dispersion pour des organismes inféodés au milieu sédimentaire souterrain. Ce travail de thèse a cherché à évaluer dans quelle mesure la géomorphologie pouvait donc structurer les communautés d’invertébrés de surface et souterraines et pouvait jouer sur la dispersion d’un organisme souterrain Proasellus walteri. Les différents résultats obtenus ont permis de montrer que la géomorphologie structurait les communautés d’invertébrés en mettant en évidence une forte réponse des communautés souterraines mais pas de surface et créait des zones de forte biodiversité à l’aval des plaines. Les résultats de cette étude ont également permis de conclure sur un effet positif de la géomorphologie des rivières en tresses sur la structuration génétique de P. walteri et de mettre en évidence de grandes tailles de populations ainsi que de fortes capacités de dispersion, permettant d’écarter certaines idées reçues sur le milieu souterrain
Braided rivers are large alluvial rivers found in piedmont mountainous areas. These rivers are very dynamic systems in space and time and exhibit particular geomorphology. The river flows alternatively into large alluvial plains or narrowing parts (also defined as canyons). This geomorphology impacts groundwater-surface water exchanges and sedimentary thickness. Groundwater-surface water exchanges occur at different scales, then interacting to shape biotic and abiotic filters for invertebrate communities. Canyons can reduce sedimentary continuity or interrupt it and may represent strong barriers to dispersal for sedimentary-dwelling organisms. This present work aimed at evaluating the effects of geomorphology in invertebrate community structure and as a potential barrier to dispersal in the subterranean organism Proasellus walteri. The different results obtained have shown that geomorphology structured invertebrate communities, highlighting a strong response in groundwater communities but not in surface communities and have shown that downstream parts of alluvial plains were hotspots of biodiversity. The results of this study also concluded on a positive effect of geomorphology in braided rivers on the genetic structure of P. walteri and underlined large effective population size and high dispersal ability, then removing some misconceptions about subterranean environment

La graine constitue le point de départ du cycle d’une plante et abrite une diversité de micro-organismes qui peuvent impacter négativement ou positivement la fitness de la plante. De plus, la graine permet la dispersion et la survie des agents phytopathogènes entre deux cycles de culture de la plante hôte. Dans ce contexte, l’objectif de ce travail était de : (i) décrypter les processus écologiques impliqués dans l’acquisition du microbiote des graines, (ii) analyser sa réponse à l’invasion par des agents phytopathogènes et(iii) suivre sa dynamique durant la germination de la graine et l’émergence de la plantule. Premièrement, nous avons analysé la structure du microbiote de graines de radis(Raphanus sativus) produites dans un même site sur trois générations successives. Ces analyses ont révélé une faible héritabilité du microbiote des graines avec peu de taxons dominants transmis d’une génération à l’autre. Ceci pourrait être expliqué par l’importance des processus neutres dans l’assemblage du microbiote des graines.Ensuite, nous avons étudié la réponse de ce microbiote à une invasion par Xanthomonas campestris pv. campestris(Xcc) et Alternaria brassicicola (Ab), deux agents phytopathogènes transmis par les graines. La transmission de Xcc aux graines n’impacte pas la composition globale du microbiote. En revanche, la transmission d’Ab modifie la structure des communautés fongiques. Ces différences de réponse sont probablement dues aux compétitions pour l’espace et les nutriments entre l’agent phytopathogène et les autres membres du microbiote. Finalement, la composition et la structure du microbiote des graines germées et des plantules ont révélé une transmission de la majorité des taxons associés à la graine y compris Xcc etAb. Globalement, les résultats de ce travail de thèse permettront à terme d’élaborer des stratégies de biocontrôle basées sur la modulation du microbiote des graines
Seed represents the initial step of the plant life cycle and harbors diverse microorganisms that can have detrimental or beneficial impacts on plant fitness. Moreover, seed represents an important means of pathogen dispersion and survival during intercrop periods. For those reasons, the aims of this work were to (i) unveil the ecological processes involved in the acquisition of the seedmicrobiota, (ii) to analyze its response against plant pathogens invasion and (iii) to monitor its dynamics during the first plant developmental stages, namely germination and emergence. First, we assessed the structure of the radish seed microbiota (Raphanus sativus) in the same experimental site across three successive plant generations. These analyses revealed a low heritability of the seed microbiota with few dominant taxa transmitted across generations. Neutral-based processes seem to be important in assembly of the seed microbiota. Second, we monitored the response of the seed microbiota to invasions by Xanthomonas campestris pv. campestris (Xcc) and Alternaria brassicicola (Ab), two seed-transmitted pathogens. While Xcc seed transmission do not change the composition of microbial communities, Ab transmission modified the structure of seed-associated fungal communities. This differences in response could be partly explained by competition for space and nutrients between the pathogenic agents and the members of the seed microbiota. Finally, composition and structure of microbial communities associated to germinating seed and seedling revealed transmission of most seed-borne microorganisms including Xcc and Ab from seed to seedling. Altogether, the results of this thesis could be helpful for designing future biocontrol strategies based on seed microbiota modulation

Research Doctorate - Doctor of Philosophy (PhD)
In the post-Apology era, Aboriginal communities and governments struggle to mitigate Aboriginal child removals. Despite concerted efforts, Aboriginal children are, at escalating rates, overrepresented at all stages of the child removal continuum. Government documents suggest implementing an integrated governance model as a solution, but no alternative to integrating Aboriginal families into the child protection system currently exists. To fill this gap, this thesis examines Aboriginal child removals from Aboriginal family perspectives, that is, the views of those with experience of the system, in order to understand the potential role of an alternative to removals. To do so, this thesis explores Australian child removals and sociologically analyses the actions and agency of Aboriginal groups interacting with statutory child protection systems. This topic is sensitive, complex, and longstanding, and thus required an Indigenist theoretical framework in order to articulate a perspective inclusive of the experiences of those most affected by child removal practices. Thus, undertaking an ethnography was critical to gaining an understanding of the perspectives of Aboriginal families on child removals, their relationships with child safety departments and how Aboriginal people raise children and support families, particularly those dealing with child protection matters. Examining different cases of child removals, this thesis analyses policy and literature sources and in-depth interviews with participants. The major finding is that the dominant and historical structures underpinning the child protection system produce and reproduce the system’s structural features and problems across time and space, limiting the part that models of Aboriginal family support could play in mitigating removals.

This chapter discloses the social aspects of a virtual organization and identifies the role of human actors in a virtual organization (consciousness). This consciousness exists in the perceptual world that we create beyond the limits of time and space. However, its counterparts exist in various forms (entities) in the real world. To bridge the gaps between the consciousnesses and the entities, there exist dual identities of human interveners in both virtual and real worlds. This research provides the meaning of virtual organization, and proceeds to explain the relationship between the consciousnesses (virtual organizations) and entities (real organizations) with human intervention (human players) using structuration theory. This study uses a theory-building process to understand human activities in virtual organizations. The theory proposed in this study reflects the epistemological positions of virtual organization research.

The deployment of telecommunication infrastructures is a challenge in many parts of South Africa particularly in the rural areas. The challenge has impact of communities' members as they do not have network coverage for Internet in some areas. The challenge gets worse with individual telecommunication service provider. Hence there is technological proposal for sharing of infrastructure by the service providers. However, the sharing of infrastructure is not as easy as notion by many individuals and groups institutions included. The article presents findings from a study on how a South African telecommunication network service provider could deploy shared infrastructures in the country's rural communities. The sharing of infrastructure is described by the structure and actions of agents within the infrastructure sharing process. Structuration theory was employed as a lens in the data analysis. The key findings include insufficient distribution of infrastructure, ownership responsibility, competitiveness, infrastructure deployment cost, and signification of regulation.

Disaster crisis communication is essential for providing adequate and successful disaster management process during disaster events. This article analyses the disaster communication in Thailand during the 2011 floods. The newspapers and government agencies found it difficult to provide timely and accessible flood information to the public. The methodology involves qualitative analysis of the data collected by questionnaire survey, key informant interviews and print news headlines from three leading newspapers in Thailand. The article involves adoption of structuration theory for analyzing the severe implication and inadequate crisis communication in Thailand during 2011 floods. The findings include the gaps in the disaster communication systems at the government level towards the local community. There is a need to provide user friendly disaster communication system to assist in resilient communities. All channels of communication including television and media, smartphones, open source data and social media must be incorporated in a comprehensive disaster communication system.

The chapter starts by elucidating the concept of the contemporary media environment as a complex interaction of two computing variables: the growth of personal computers, and the popularity of the Internet and World Wide Web. This environment is then analysed for its impacts on collective processes in both virtual and physical communities. It is argued that these collective processes contain multiplier effects; and one of these effects lies in the subtractability of resources; an important concept in the knowledge commons. Examples are used to illustrate these perspectives. The author maintains, throughout the chapter, that it is essential to see all of these interactions as two-way, dialogical relationships and structuration theory is used in support of this argument. As a concluding note, the chapter makes a number of forecasts on the benefits and potential pitfalls for the society as a result of these relationships.

Inter-Organizational Information Systems (IOIS) are computer-based systems shared by, or connecting, several organizations. The on-going use and evolution on long timescales of these large-scale socio-technical systems so far cannot be satisfactorily explained on the basis of existing theories of IS adoption, implementation, and use. In this chapter, we present a theory of IOIS in which the on-going use and evolution of IOIS is treated as a practical and socio-material accomplishment of communities through boundary practices and structures. We draw on the structure/action reproduction paradigm of Structuration Theory to account for the persistence of these systems, and thus explain their structure, while using the embodiment of action from Practice Theory to treat the material nature of these systems. We distinguish three dimensions of structure—material, normative, and ideational—and we also distinguish patterns of actions (along these three dimensions) from constraining and enabling structures. However, we attempt to treat these three structural dimensions and their reproduction processes symmetrically throughout. This symmetrical treatment leads us to propose that these action/structure dimensions are not reproduced in isolation but rather undergo an intimate mixing, or mangling, in the process, which in turn suggests a new kind of two-way causal accommodation between the various aspects of structure that we term “resonance.”