Thesis (MTech (Information Technology))--Cape Peninsula University of Technology, 2018. / With the constant evolution of information systems, companies have to acclimatise to the vast increase of data flowing through their networks. Business processes rely heavily on information technology and operate within a framework of little to no space for interruptions. Cyber attacks aimed at interrupting business operations, false intrusion detections and leaked information burden companies with large monetary and reputational costs. Intrusion detection systems analyse network traffic to identify suspicious patterns that intent to compromise the system. Classifiers (algorithms) are used to classify the data within different categories e.g. malicious or normal network traffic. Recent surveys within intrusion detection highlight the need for improved detection techniques and warrant further experimentation for improvement. This experimental research project focuses on implementing swarm intelligence techniques within the intrusion detection domain. The Ant Tree Miner algorithm induces decision trees by using ant colony optimisation techniques. The Ant Tree Miner poses high accuracy with efficient results. However, limited research has been performed on this classifier in other domains such as intrusion detection. The research provides the intrusion detection domain with a new algorithm that improves upon results of decision trees and ant colony optimisation techniques when applied to the domain. The research has led to valuable insights into the Ant Tree Miner classifier within a previously unknown domain and created an intrusion detection benchmark for future researchers.

Combinatorial optimisation problems (COPs) pervade human society: scheduling, design, layout, distribution, timetabling, resource allocation and project management all feature problems where the solution is some combination of elements, the overall value of which needs to be either maximised or minimised (i.e., optimised), typically subject to a number of constraints. Thus, techniques to efficiently solve such problems are an important area of research. A popular group of optimisation algorithms are the metaheuristics, approaches that specify how to search the space of solutions in a problem independent way so that high quality solutions are likely to result in a reasonable amount of computational time. Although metaheuristic algorithms are specified in a problem independent manner, they must be tailored to suit each particular problem to which they are applied. This thesis investigates a number of aspects of the application of the relatively new Ant Colony Optimisation (ACO) metaheuristic to different COPs.The standard ACO metaheuristic is a constructive algorithm loosely based on the foraging behaviour of ant colonies, which are able to find the shortest path to a food source by indirect communication through pheromones. ACO’s artificial pheromone represents a model of the solution components that its artificial ants use to construct solutions. Developing an appropriate pheromone representation is a key aspect of the application of ACO to a problem. An examination of existing ACO applications and the constructive approach more generally reveals how the metaheuristic can be applied more systematically across a range of COPs. The two main issues addressed in this thesis are biases inherent in the constructive process and the systematic selection of pheromone representations.The systematisation of ACO should lead to more consistently high performance of the algorithm across different problems. Additionally, it supports the creation of a generalised ACO system, capable of adapting itself to suit many different combinatorial problems without the need for manual intervention.

Consensus conferences evolved as a response to the public's increasing dissatisfaction with technocratic decision-making processes that are judged to have repeatedly failed to serve its interests. The staging of the first Australian consensus conference at Old Parliament House in Canberra in March 1999 therefore presented an ideal opportunity to analyse the evolution of this new kind of policy input from its conception through to its implementation and subsequent evaluation. This thesis set out to provide an analysis of that trajectory using elements of the theoretical approach known as actor-network theory (ANT). Previous analyses of consensus conferences have generally provided only limited evaluations of single aspects of the entire process of setting up, implementing and evaluating such a conference. Furthermore, many of the early evaluations were conducted by reviewers or units which were themselves internal to the consensus conference under scrutiny. My own analysis has tried to offer broader, although inevitably less detailed, coverage, using a perspective from contemporary social theory that offers particular advantages in analysing the creation of short-term networks designed for specific purposes. By describing and analysing the role of this relatively new policy-making instrument, I have explored the different sub-networks that operate within the consensus conference process by focussing on the ways in which the conference was organised and how the relationships between the organisers and the participants helped to shape the outcomes. Thus the entire consensus conference sequence from idea to outcome can be thought of as a construction of a network to achieve at least one immediate goal. That goal was a single potential policy input, a consensus position embodied in the report of the lay panel. To realise that goal, the network needed to be recruited and stabilised and its members made to converge on that collective statement. But how is it that a range of disparate actors, including lay and expert, are mobilised to achieve that particular goal and what are the stabilisation devices which enable, or fail to enable this goal to be reached? In the context of the first Australian consensus conference, three key alignment devices emerged: texts, money and people. Yet it is clear from the evidence that some of these network stabilisation devices functioned poorly or not at all. This thesis has drawn attention to the areas in which they were weak and what importance that weakness had for the kind of policy outcome the consensus conference achieved. The role and extent of these powerful stabilisation devices in networks was therefore a vital issue for analysis. If one of the criteria to evaluate the success of a consensus conference is that it provides the stimulus to hold another, then the Australian conference must be deemed so far a failure. No further Australian consensus conference is planned. However, Australia stands to forfeit a number of advantages if no further consensus conferences or similar occasions are organised. Policy formation in contemporary democracies has had to accommodate an increasing array of new participants in order to track more effectively the diversity of potentially significant opinions on complex policy issues. This process requires new and transparent ways to educate and inform the public on policy issues and to ensure that policy makers are better informed about the needs and concerns of their community. As the evidence presented in thesis for the Australian example and its predecessors overseas suggests, consensus conferences have the potential to play a role in the contemporary policy-making context. But the realisation of that potential will vary according to their institutional contexts and the capacity of the actors to create the temporarily most stable and productive network out of the heterogeneous human and material resources to hand.

Background: Myrmecia pilosula (the jack jumper ant, JJA) is the principal cause of ant venom anaphylaxis in Australia. Whereas honeybee and wasp venom allergy can be treated by venom immunotherapy (VIT), no such treatment is available for ant sting allergy. In addition, information on the natural history of JJA sting allergy is required to identify those most likely to benefit from immunotherapy. The main objectives of this research were to establish: (i) the prevalence, natural history and determinants of reaction severity for JJA allergy, and; (ii) the efficacy and tolerability of JJA VIT. Methods: A search of the Royal Hobart Hospital (RHH) forensic register, a random telephone survey, and a review of emergency department (ED) presentations were performed. Three hundred eighty-eight JJA allergic volunteers were assessed, including serum venom-specific IgE RAST, and then followed up for accidental stings over a 4-year period. Finally, a randomised double-blind, placebo-controlled, crossover trial of JJA VIT was performed. Laboratory parameters measured during the trial were; leukocyte stimulation index (SI), IL-4 production, IgE RAST, histamine release test (HRT), leukotriene release test (LRT) and basophil activation test (BAT). Intradermal venom skin testing (VST) was also performed at trial entry. Findings: The prevalence of JJA sting allergy was 2.7% in the Tasmanian population, compared to 1.4% for honeybee. People aged 35 or older had a greater risk of both sting allergy and hypotensive reactions. Four deaths were identified, all in adults with significant comorbidities. During follow-up, 79 (70%) of 113 accidental jack jumper stings caused systemic reactions. Only prior worst reaction severity predicted the severity of follow-up reactions, with the majority of people experiencing similar or less severe reactions when stung again. Sixty-eight otherwise healthy JJA allergic adult volunteers were enrolled in the clinical trial. Systemic reactions to therapy were recorded in 34% during VIT. Objectively defined systemic reactions to sting challenges arose in 1/35 after VIT (mild self-limiting urticaria only) versus 21/29 in the placebo group. Treatment with oxygen, intravenous adrenaline infusion and volume resuscitation was effective and well tolerated. Hypotension was always accompanied by a relative bradycardia, which was severe and treated with atropine in two patients. In the placebo group, only VST and HRT were predictive of sting challenge results. Although IgE RAST, leukocyte SI and IL-4 production, LRT and BAT all correlated well with VST, they did not predict sting challenge outcome. After successful VIT, venom-induced leukocyte IL-4 production tended to fall, whereas IgE RAST increased and a natural decline in HRT reactivity was reversed. Interpretation: VIT is highly effective in prevention of JJA sting anaphylaxis and is likely to be of most benefit to people with a history of severe systemic reactions, which usually occur in people aged over 35. Neurocardiogenic mechanisms &/or direct cardiac effects may be important factors in some anaphylaxis deaths. Systemic reactions to immunotherapy are common and require immediate access to resuscitation facilities. The HRT warrants further investigation as a test for selecting those most likely to benefit from VIT. None of the tests evaluated appear to be reliable markers of successful VIT.

This study examined the ant communities of several grasslands of the Australian Capital Territory (ACT) and their relevance to the pink-tailed legless lizard, Aprasia parapulchella (Pygopodidae). A. parapulchella is a fossorial species that shares burrows with, and eats the brood of, several grassland ant species. Foraging ants were collected from sites by pitfall trapping throughout one calendar year and comparisons of ant communities made between seasons and sites of differing vegetation structure. Competition between ant species for artificial nest sites and the effects of temperature on selection of nest site selection were also studied. The role that ants play in the distribution of A. parapulchella was investigated by (i) comparing ant faunas from several sites throughout the geographic range of the lizard, including sites in New South Wales and Victoria, (ii) performing feeding preference experiments with A. parapulchella, and (iii) investigating the seasonal nature of brood production and nest establishment by ants in ACT grasslands. Major findings were used to make recommendations to assist in the management, including rehabilitation, of A. parapulchella grassland sites. Low insolation appears to significantly affect the ant species composition of grassland sites in the ACT relative to other Australian vegetation types. In the ACT grassland sites, large species of the Dominant Dolichoderinae functional group were absent, or present only in very low numbers. The communities were species-poor relative to other Australian studies with only 60 species being recorded across all sites studied, with no more than 21 species recorded at any site on any sampling occasion. Whilst ant species community structure was highly variable between seasons and sites, more than 95% of ants were from the three functional groups, Dominant Dolichoderinae, Generalized Myrmicinae and Opportunists. The communities were numerically dominated throughout the year by the ubiquitous species groups Iridomyrmex 'rufoniger' and Rhytidoponera 'metallica'. Almost all taxa increased in foraging abundance during summer months and Pheidole spp., Monomorium spp., Crematogaster sp. Paratrechina sp. and Notoncus ectalomoides were occasionally locally abundant. There were no significant relationships between ant and vegetation community structures, but Solenopsis sp. showed an alliance with sites that had a high abundance of Themeda australis (kangaroo grass), whilst Crematogaster sp. and Paratrechina sp. are potential bioindicators of disturbance from grazing or pasture improvement. Iridomyrmex 'rufoniger' were the numerically dominant foraging ants, making up 50% of all captures, but they held only 80% of their nest sites when faced with competition from other species. R. 'metallica' and Pheidole spp. on the other hand, gained 80% more nests than they lost to other taxa. I. 'rufoniger' and R. 'metallica' both preferred nest sites with warmer temperature regimes when given the choice, and this assisted them to tend brood throughout the year. All ant species in ACT grasslands had summer peaks in brood production. Most nests were inactive throughout the cooler months and nest founding was predominantly between September and November. The common species, Iridomyrmex spp., Paratrechina sp. and R. 'metallica' held winged reproductives in their nests from April and all ant taxa had released all alates by mid- November. Although there were differences in ant community structure throughout the range of A. parapulchella, the ubiquitous R. 'metallica' and I. 'rufoniger' were always abundant, whilst again, Dominant Dolichoderinae and associated subordinate taxa were absent or present only in relatively low numbers. The lizards consumed brood from all the common ant species in ACT grasslands and showed preference for consuming brood of, and living with, small Iridomyrmex spp. The range of the small Iridomyrmex spp. preferred by A. parapulchella extends far beyond that of the lizard. Its distribution is apparently not restricted by the range of its ant prey species. For rehabilitation of A. parapulchella sites in the ACT, it is recommended that a significant ground cover of native grasses is established to ensure the low abundance of large and territorial ants from the Dominant Dolichoderinae functional group. Along with a high abundance of shallow surface rocks, this will ensure the establishment of ant communities that are numerically dominated by small Iridomyrmex spp., which are preferred by A. parapulchella for homesite sharing and as a food source.

<p><p>Den här uppsatsens syfte är att belysa och analysera ungdomars uppfattningar om och eventuella erfarenheter av den allt vanligare digitala mobbningen, det vill säga mobbning som sker via olika arenor på Internet eller via mobiltelefoni. Frågor som rört hur användningen av digitala arenor ser ut bland ungdomarna, vad de uppfattar att digital mobbning är, om det finns någon skillnad mellan flickors och pojkars sätt att mobba, samt vilka konsekvenser de anser att mobbningen får, har analyserats med hjälp av Bruno Latours aktör-nätverksteori och ur ett genusperspektiv. För att uppfylla studiens syfte har jag använt mig av kvalitativa fokusgruppsintervjuer med ungdomar från årskurs åtta från två skolor. Intervjuerna var uppdelade i flick- respektive pojkgrupper.</p><p>Genom ungdomarnas framställning av vad mobbning är framgår det att det i huvudsak handlar om att det är <em>den utsatte</em> som avgör och definierar om det är <em>mobbning eller bråk</em> som äger rum. De säger att det är svårt att fastställa gränsen mellan mobbning och bråk då det ofta beror mycket på vem det är som säger det, vilken situation det är samt hur personen som får kommentaren reagerar, om den tar åt sig eller inte. Det handlar med andra ord om den utsattes tolkning av situationen, det är han eller hon som till syvende och sist definierar mobbningen. Mot bakgrund av informanternas berättelser om hur den digitala tekniken användas för att mobba blir det tydligt att mobbningens utseende förändras på många olika sätt i förhållande till den analoga: fler kan se mobbningen, fler kan involveras genom möjligheten att vara anonym och ungdomarna vågar mer vid digital mobbning. Två områden är här särskilt framträdande. För det första framställs den digitala mobbningen som att den <em>pågår överallt och hela tiden</em>, den försvinner aldrig, den pågår dygnet runt. Samtidigt framgår det att mobbningen ofta har ett samband med analog mobbning. För det andra skapar den digitala mobbningen helt andra förutsättningar för <em>mobbare och mobbade</em>. Mobbarna vågar mer genom möjligheten till att vara anonym, vilket resulterar i att också den "svaga" kan mobba. Undersökningen visar även att den som blir mobbad digitalt lättare kan få hjälp av andra vid offentliga inlägg eller kommentarer.</p></p>

Solenopsis invicta, the red imported fire ant, has recently become associated with Antonina graminis, an invasive pest, and Neodusmetia sangwani, biological control agent, and maybe negatively affecting established biological control. A preliminary survey outlined the range of A. graminis and its parasitoids, and found N. sangwani was present at a reduced rate in South Texas and in the southeastern United States. A greenhouse experiment demonstrated that S. invicta decreased the rate of parasitism of A. graminis by N. sangwani, with S. invicta directly interfering with oviposition. Interactions between S. invicta and A. gaminis may be facilitating the spread and establishment of two invasive pests which has a negative impact on established classical biological control of A. graminis by N. sangwani.

Most Aphidinae species produce and use (E)-ß-farnesene (Eßf) as an alarm pheromone. This sesquiterpene is released by individuals under attack by a predator, and nearby aphids exhibit a variety of alarm behaviours. This PhD thesis aims to better understand how aphids manage their production and emission of alarm pheromone (Chapter IV). We also wanted, in a second step, to improve our knowledge on the roles that Eßf could play in the relationships that aphids have with their predators (Chapter V) and tending ants (Chapter VI), in order to better pinpoint the problem in this very tough context. The aphid predators have indeed a real advantage to be able to use the odorant cues emitted by their prey, to locate them and to select an adequate oviposition site. Ants establish with certain aphid species mutualistic relationships, which occurrence could be facilitated by the use of aphids odours. In Chapter IV, we have highlighted that aphid colonies non subjected to attack by predators release constantly small quantities of Eßf in their headspace, which means that this molecule could have additional roles than just acting as an alarm pheromone. In a second study, we demonstrated that the release of Eßf was not contagious, and therefore that a non stressed aphid receiving the alarm signal does not release additional Eßf. Since the production of alarm pheromone is likely to entail physiological cost, we tested and validated the hypothesis that aphids regulate their Eßf production according to their social environment. In Chapter V, we studied the ability of the hoverfly predator Episyrphus balteatus (Diptera, Syrphidae) to be used as biological control agent against aphids infesting tomato plants (Lycopersicon esculentum). After identifying the odours emitted by aphid infested plants, we have demonstrated that although this Diptera is able to perceive all the odours released by the system, it mainly uses Eßf to select its oviposition site. However, the E. balteatus larvae are not adapted to the architecture of tomato plants. We also showed that the Asian ladybeetle Harmonia axyridis (Coleoptera, Coccinellidae) olfaction was adapted to the perception of Eßf and that this beetle is also attracted by this sesquiterpene. Finally, in Chapter VI, we characterized the benefits accruing to aphid populations that have established mutualistic relationships with Lasius niger (Hymenoptera, Formicidae), and have demonstrated the role of Eßf and honeydew, respectively in locating aphid colonies and in the persistence of the mutualism. La plupart des espèces de pucerons appartenant à la sous-famille des Aphidinae produisent et utilisent le (E)-ß-farnésène (Eßf) comme phéromone dalarme. Ce sesquiterpène est relargué par les individus stressés par lattaque dun prédateur et cause chez les individus qui le perçoivent un comportement dalerte. La présente thèse de doctorat a pour objectif de comprendre comment les pucerons gèrent la production et émission de phéromones dalarme (Chapitre IV). Nous voulions aussi, dans une seconde étape, améliorer les connaissances sur les rôles potentiels que cet Eßf peut jouer au sein des relations que les pucerons entretiennent avec leurs prédateurs (Chapitre V) et avec les fourmis (Chapitre VI) Les prédateurs de pucerons retirent en effet un réel avantage à pouvoir saider des odeurs émises par leurs proies pour les localiser et pour sélectionner un site doviposition adéquat. Les fourmis, quant à elles, établissent des relations de mutualisme avec certaines espèces de pucerons. Les rencontres entre fourmis et pucerons pourraient être facilitées par lutilisation des odeurs de pucerons. Les résultats obtenus peuvent être résumés de la manière suivante: Dans le chapitre IV, nous avons mis en évidence que les colonies de pucerons non soumises à lattaque de prédateurs relarguent constamment de faibles quantités dEßf, ce qui permet dassumer que cette molécule puisse avoir dautres fonctions que celle de phéromone dalarme. Dans une deuxième étude, nous avons démontré que lémission du Eßf nétait pas contagieuse, et donc quun puceron non stressé percevant le signal dalarme német pas à son tour de le Eßf. Puisque la production de phéromone dalarme a inévitablement un coût physiologique, nous avons testé et validé lhypothèse selon laquelle les pucerons régulent leur production de Eßf en fonction de leur environnement social. Dans le chapitre V, nous avons étudié la possibilité dutiliser le syrphe prédateur Episyrphus balteatus (Diptera, Syrphidae) en lutte biologique contre les pucerons infestant les plants de tomate (Lycopersicon esculentum). Après avoir identifié les odeurs émises par les plants infestés, nous avons démontré que, si ce Diptère est capable de percevoir lensemble des odeurs émises par ce système tritrophique, il utilise principalement lEßf pour sélectionner son site doviposition. Cependant, les larves dE. balteatus ne sont pas adaptées à larchitecture des plants de tomate. Nous avons également montré que la coccinelle asiatique Harmonia axyridis (Coleoptera, Coccinellidae) possède le matériel olfactif nécessaire à la perception du Eßf et quelle est aussi attirée par ce sesquiterpène. Enfin, dans le chapitre VI, nous avons caractérisé les bénéfices retirés par les populations de pucerons ayant établi des relations de mutualisme avec Lasius niger (Hymenoptera, Formicidae), et avons démontré le rôle du Eßf et du miellat, respectivement dans la localisation des colonies de pucerons et dans la persistance du mutualisme.

Contexte: La fragmentation des habitats induisant une diminution de leur surface, de leur connectivité et une augmentation de la zone de contact avec d’autres milieux constitue l’une des menaces majeures pour le maintien de la biodiversité. Les effets de la fragmentation ne doivent pas être confondus avec les perturbations transitoires liées à un morcellement de l’habitat par une déforestation récente. Les îlots forestiers du Chaco humide, situés sur des monticules légèrement surélevés par rapport à la savane environnante qui est régulièrement inondée et brûlée, constituent un système naturellement fragmenté propice à l’étude des effets de la fragmentation sensu stricto. Dans ces forêts subtropicales sèches, comme dans la plupart des écosystèmes terrestres, les fourmis constituent l’un des organismes les plus abondants. Objectif: Le but principal de la thèse a été de déterminer, à trois échelles spatiales, les facteurs influençant la structure des assemblages de fourmis terricoles : (1) à l’échelle du microhabitat constitué par la litière de feuilles et la couverture végétale dominée par des broméliacées terrestres ; (2) à l’échelle du fragment forestier dont la surface, la forme et l’isolement est variable ; (3) à l’échelle du paysage, constitué de forêt et de savane, soumis à des feux périodiques, et au niveau duquel nous nous sommes intéressés aux effets de bord se produisant à l’interface entre les deux milieux. Méthode: Le site d’étude est la forêt naturellement fragmentée du Parc national Rio Pilcomayo localisé dans le Chaco humide argentin. Onze fragments forestiers de taille (± 2.5ha, 25ha et 250ha), de forme et de degré d’isolation divers ont été échantillonnés ainsi que la savane environnante, récemment brûlée ou non. La diversité et la densité des fourmis a été quantifiée au moyen d’un protocole standardisé (« protocole A.L.L. ») qui a été préalablement calibré pour en définir la représentativité. Ce protocole consiste en un transect de 200m le long duquel sont placés, à intervalles de 10m, des pièges à fosse et des quadrats délimitant 1m² de litière de feuilles. La faune vivant dans la litière est ensuite extraite au moyen d’un dispositif appelé Winkler. Le calibrage du protocole a été réalisé en suréchantillonnant 8 fois le transect (160 points d’échantillonnage au lieu de 20). Cet échantillonnage quasi exhaustif de 200m² a permis de comparer l’estimation du nombre d’espèces obtenue par le transect standardisé ALL avec sa valeur réelle et d’étudier la distribution des espèces à l’échelle du mètre. Les facteurs du microhabitat les plus susceptibles d’influencer la distribution des fourmis (quantité de litière et densité de broméliacées) ont été mesurés systématiquement le long des transects. Pour l’étude de la distribution des fourmis depuis le coeur d’un grand fragment jusque dans la savane, des transects de 500m ont été utilisés et ont permis de mesurer des effets de bords éventuels. Un total de 800 Winkler et 560 pièges à fosses ont été analysés lors de cette étude. Résultats: Un transect standardisé A.L.L. permet d’obtenir, à partir de 20 échantillons et de méthodes analytiques adéquate, une estimation fiable de la richesse locale au sein de 200m² mais n’est pas toujours représentatif de la fréquence relative des espèces. Au total, 150 espèces de fourmis ont été récoltées dont 130 en forêt et 79 en savane (dont 59 espèces communes aux deux milieux). Au niveau du micro-habitat, on observe pour certaines espèces des pics périodiques d’abondance (maximum tous les 10m) correspondant vraisemblablement à l’emplacement des colonies qui s’espacent pour diminuer la compétition intraspécifique. Associé aux micrconvexités topographiques l’on observe également des pics de densité de broméliacées et de quantité de litière qui favorisent une grande densité d’espèces différentes de fourmis. À l’échelle de l’habitat, les îlots forestiers petits et isolés sont les moins riches, principalement en espèces typiquement forestières. Dans les larges fragments, les espèces typiquement forestières se distribuent indépendamment de la distance les séparant du bord. Quelques espèces typiques de savane pénètrent en bordure de forêt et provoquent une plus grande variabilité de la faune récoltée au sein des quadrats de litière situés à cet endroit. Cependant, aucun pic de diversité correspondant à une zone de superposition d’espèces de bord et de centre n’a été observé au sein des fragments forestiers. Les feux de savane modifient la fréquence relative des espèces les plus communes mais n’affectent pas la richesse globale du milieu et ne pénètrent pas dans la forêt. Conclusions: Le protocole standardisé ALL, utilisé couramment par de nombreuses équipes de chercheurs à travers le monde, mais qui n’avait encore jamais été réellement calibré avant notre étude, apparaît comme une méthode minimale mais suffisante pour déterminer la richesse locale en fourmis d’une forêt du Chaco humide. Ce calibrage a permis, en outre, de mettre en évidence un taux important de renouvellement des espèces à l’échelle du mètre carré. Nos résultats soutiennent l’idée que la disponibilité en ressources favorables, plus que la compétition interspécifique, est un mécanisme majeur structurant les assemblages de fourmis des litières. À l’échelle du micro-habitat, un grand nombre d’espèces de fourmis forestières coexistent dans les zones riches en matière organique associée à la présence de broméliacées qui apparaissent comme un facteur structurant majeur de la distribution des fourmis. Au niveau de la litière, les colonies de différentes espèces ont des aires de fourragement qui se superposent tandis que les colonies de même espèce ont tendance à s’espacer limitant la compétition pour les mêmes ressources. Un effet de bord, lié à des modifications locales des conditions climatiques et de la structure de la végétation, ne se marque pas au niveau de la myrmécofaune dans ce type de milieu, ce qui explique que l’on n’observe pas le traditionnel pic de diversité au niveau de la zone de transition entre deux milieux. Du point de vue de la conservation des espèces, des fragments forestiers de 15ha, bien connectés, apparaissent comme des conditions minimum pour conserver l’ensemble des espèces de fourmis de l’assemblage.

Den här uppsatsens syfte är att belysa och analysera ungdomars uppfattningar om och eventuella erfarenheter av den allt vanligare digitala mobbningen, det vill säga mobbning som sker via olika arenor på Internet eller via mobiltelefoni. Frågor som rört hur användningen av digitala arenor ser ut bland ungdomarna, vad de uppfattar att digital mobbning är, om det finns någon skillnad mellan flickors och pojkars sätt att mobba, samt vilka konsekvenser de anser att mobbningen får, har analyserats med hjälp av Bruno Latours aktör-nätverksteori och ur ett genusperspektiv. För att uppfylla studiens syfte har jag använt mig av kvalitativa fokusgruppsintervjuer med ungdomar från årskurs åtta från två skolor. Intervjuerna var uppdelade i flick- respektive pojkgrupper. Genom ungdomarnas framställning av vad mobbning är framgår det att det i huvudsak handlar om att det är den utsatte som avgör och definierar om det är mobbning eller bråk som äger rum. De säger att det är svårt att fastställa gränsen mellan mobbning och bråk då det ofta beror mycket på vem det är som säger det, vilken situation det är samt hur personen som får kommentaren reagerar, om den tar åt sig eller inte. Det handlar med andra ord om den utsattes tolkning av situationen, det är han eller hon som till syvende och sist definierar mobbningen. Mot bakgrund av informanternas berättelser om hur den digitala tekniken användas för att mobba blir det tydligt att mobbningens utseende förändras på många olika sätt i förhållande till den analoga: fler kan se mobbningen, fler kan involveras genom möjligheten att vara anonym och ungdomarna vågar mer vid digital mobbning. Två områden är här särskilt framträdande. För det första framställs den digitala mobbningen som att den pågår överallt och hela tiden, den försvinner aldrig, den pågår dygnet runt. Samtidigt framgår det att mobbningen ofta har ett samband med analog mobbning. För det andra skapar den digitala mobbningen helt andra förutsättningar för mobbare och mobbade. Mobbarna vågar mer genom möjligheten till att vara anonym, vilket resulterar i att också den "svaga" kan mobba. Undersökningen visar även att den som blir mobbad digitalt lättare kan få hjälp av andra vid offentliga inlägg eller kommentarer.