Dissertations / Theses on the topic 'Colonization'

The colonization of Space is the process of creating human settlements beyond the Earth. Theoretically, the colony can be placed: оn the planets, their moons, asteroids; оn the orbits of the celestial bodies; in the Lagrange‘s points. The most popular projects of colonization are the colonization of Moon and Mars, and the creation of orbital colonies.

This thesis aims to shed some lights on the actual conditions of Aboriginal Australians throughout history and today. Many stereotypes are commonly known about them and many of them are incorrect, starting from the notion that Captain Cook discovered Australia. Australia was not discovered by the British, it already hosted a multitude of cultures before the Europeans arrived.

This critical rhetorical critique interrogates rhetorics of memory in negotiations of national identity, especially as they address race and colonialism. We need to rethink race in more complex ways that disrupt homogenous conceptions of who belongs in the U.S., instead embracing the possibilities offered in those liminal spaces of racial national identities, such as (Native)American. Doing so requires acknowledging the reverberations of past rhetorics in contemporary sense-making and how those echoes vary across communities. In exploring how we (mis)remember race and colonization in relation to nation, my concern lies in exposing some of the persistent rhetorical strategies that impede social justice efforts by marginalized communities, as well as the resistive rhetorics these communities respond with.

Pursuing this project, I rely on investigating rhetorical mnemonic strategies of race, nation, and colonialism in everyday discourses about the relationship(s) between a Euro-American community in Lawrence, Kansas and a pan-Indian community associated with Haskell Indian Nations University (HINU) to reveal how we negotiate national identities in relation to the past and to one another. At its core, this ideological critique of rhetorics of race, nation, memory and colonialism is an investigation of identity negotiation among two representative communities in disparate positions of power, their places constituted across several centuries of racist discourses that we too-often continue to rely on. In examining historic Assimilation Era discourses from Haskell Indian Boarding School as well as recent discourses produced by the Lawrence, Kansas, and HINU communities about a local land controversy, I interrogate the role of memory in contemporary negotiations of identity and reveal ways the normative assumptions of U.S. citizenship are profoundly raced. I also propose the idea of “enabling uncertainty” as a perspective that explicitly troubles narrow and limiting conceptions of racial identities, highlighting the idea through discussion of the complex ways (Native)Americans navigate the interstices between Native and American identities.

This is a study of the pursuit of African American colonization as a state and latterly a federal policy during the period c. 1850-65. Historians generally come to the topic via an interest in the Civil War and especially in Lincoln, but in so doing, they saddle it with moral judgment and the burden of rather self-referential debates. The thesis argues that, whilst the era’s most noteworthy ventures into African American colonization did indeed emerge from the circumstances of the Civil War, and from the personal efforts of the president, one can actually offer the freshest insights on Lincoln by bearing in mind that colonization was, above all, a real policy. It enjoyed the support of other adherents too, and could be pursued by various means, which themselves might have undergone adjustment over time and by trial and error. Using an array of unpublished primary sources, the study finds that Lincoln and his allies actively pursued colonization for a longer time, and with more persistence in the face of setbacks, than scholars normally assume. The policy became entangled in considerations of whether it was primarily a domestic or an international matter, whilst other overlapping briefs also sabotaged its execution, even as the administration slowly learned various lessons about how not to go about its implementation.By early 1864, the resulting confusion, as well as the political fallout from the fiasco of the one expedition to go ahead, curtailed the president’s ability to continue with the policy. There are strong suggestions, however, that he had not repudiated colonization, and possibly looked to revive it, even as he showed a tentative interest in alternative futures for African Americans. This thesis makes a case against unrealistically binary thinking, anachronistic assumptions, abused hindsight, sweeping interpretive frameworks, and double standards of evidentiary assessment respecting a technically imperfect and ethically awkward policy.

Includes abstract.
Includes bibliographical references (leaves 95-102).
In this study, I explored factors that influence forest colonization in a South African savanna. I used a 50 year fire experiment in the Kruger National Park to explore patterns of forest colonization in a mesic Terminalia sericea savanna. I studied woody seedling and sapling distribution in relation to different burning treatments, including no burning, and microsite position - in the open or under the canopy of tall trees. The study showed that species richness and abundance was greatest under Sclerocarya birrea, low under Terminalia sericea and lowest in the open habitats. Low fire frequency increased species richness and abundance under S. biirea, but not under T. sericea or the open habitats. Fire sensitive or fire-intolerant species were highest under tree canopies on unburnt and triennial burn plots, whereas frequently burnt (annual or biennial) plots, had fire tolerant and typical savanna species. Frequent burning reduced woody plant biomass by killing seedlings, saplings and adult trees. Fire exclusion led to a higher seedling and sapling recruitment under S. birrea and T. sericea than open habitats.

This paper discusses a modular open source electronic soil analysis system embedded in a remote vehicle designed for use on a colonizationeffort Mars rover. The embedded system consists of a soil extraction drill sheath, a temperature and moisture array sensor sheath, a sample return bay specialized for RamanFluorescence spectrometry, and an Ethernet bridge radio for communication, all controlled through several microcontroller boards. A Windowsbased graphical engagement application provides real time control. A Linuxbased scripting application provides postprocessing, graphing, and statistical analysis. All software and electrical hardware has been made opensource for the public to build upon.

L'ile de Taiwan est apparue, il y a deux millions d'années. Nous avons étudié les figuiers de Taiwan afin de comprendre comment l'ile fut colonisée et comment l'insularité a pu affecter les espèces colonisatrices. Le genre Ficus est caractérisé par son association mutualiste avec des insectes pollinisateurs extrêmement dispersifs. De plus les figues, inflorescences fermées des Ficus, sont consommés par un grand nombre d'espèces qui elles aussi dispersent efficacement les graines. Nous avons développé une série de marqueurs génétiques afin de pouvoir étudier plusieurs espèces avec les mêmes outils. Ensuite nous avons analysé la structure génétique dans Taiwan d'un groupe de quatre espèces. Une espèce présenta une différenciation génétique claire dans le Sud de Taiwan au climat plus chaud, suggérant la possibilité un début de spéciation écologique chez une espèce hautement dispersive. Une seconde espèce a montré des indices de processus de sélection en cours dans le Sud de Taiwan. A une échelle plus étendue, nous avons montre que les données microsatellites et spécifiquement les R statistiques donnent un premier aperçu de la phylogéographie des figuiers. Pour plusieurs espèces, l'Asie continentale semble être la trame de fond génétique de ces espèces malgré une forte différenciation parmi les populations. Pour Ficus variegata, nous avons montré que la colonisation de Taiwan a pour origine les Philippines et nous n'avons pas détecté de trace de flux génétique venant du continent. L'étude de la phénologie reproductive des Ficus suggère que seulement des espèces produisant de fréquentes récoltes ont colonisé l'ile. Ces travaux ouvrent de nombreuses perspectives sur la réponse des figuiers à l'insularité
The Island of Taiwan appeared some two million years ago. We investigated the Ficus species of Taiwan in order to understand how the island was colonized and how insular conditions affected the colonizing species. Genus Ficus is characterized by its mutualistic association with highly dispersive pollinating wasps. Further figs, the closed inflorescences of Ficus, are consumed by a large number of highly efficient seed dispersers. We developed a set of portable genetic markers in order to analyze several species using a single set of markers. We then analyzed genetic structuring within Taiwan in a set of four species. One species presented clear genetic differentiation in the warm south Taiwan, suggesting the possibility of incipient ecological speciation in a highly dispersive species. Another species presented indications of ongoing selective processes also in south Taiwan. On a broader scale we show that microsatellite data and notably R statistics provide useful insights into Ficus phylogeography. In several species, continental Asia seems to correspond to a single genetic background despite strong genetic differentiation among populations. For Ficus variegata, we show that it colonized Taiwan from the Philippines and we detect no trace of gene flow from the continent. An investigation of Ficus reproductive phenology suggests that only species producing frequent fig crops have established on the island. This work opens up a series of perspectives on the response of Ficus to insular conditions

ABSTRACT Background. The intestinal microbiome is relatively dynamic during the first years of life, becoming relatively stable throughout a lifetime, thus dictating adult life's future health. There are many factors influencing gut microbiome composition, including maternal pre-pregnancy, body mass index (BMI), gestational weight gain (WG), type of feeding, weaning timing, and birth/family environment. Objectives. The study aims to investigate the intestinal microbiome development of infants (ages 0-12 months) and to analyze how prenatal and postnatal factors, including maternal BMI and weight gain during pregnancy, type of feeding, time and type of weaning, and the presence of siblings in the family, could influence the infant gut microbiome composition at one year of age. Methods. 63 dyads were enrolled at Neonatal Unit, IRCCS Policlinico San Matteo, Pavia. Anthropometric parameters were assessed before discharge (T0), at 30 days from birth (T1), at 6 months (T2) and 1 year (T3); validated questionnaires were used to evaluate mother’s dietary habits and physical activity at each time. Mothers were interviewed about family environment and infants feeding/supplementation at each time. For each child a stool sample was collected at each time and analyzed using metagenomics 16s ribosomal RNA gene sequence-based methods. Cluster and correlation analysis were used to assess changes in the microbial composition across different follow-up times. Results. At one years of age, pre- and perinatal variables were not significantly associated with any bacterial taxon, while postnatal variables showed the major contribution in shaping microbiota. Feeding and weaning were the main influencing factors. Conclusion. Our findings highlighted that microbial colonization during the first year of life is likely affected by various factors resembling a simultaneous effect of multiple variables. Mainly, different variables play a significant role at different time. Thus, these data contribute to add evidence concerning the complex multifactorial interaction of GI-microbiota depending on the various stimuli during the early stages of life. This study will provide the starting point for a future prospective and observational study assessing the potential association between maternal diet and life-style with newborns microbiome composition, their influence on childhood obesity development and the associated increased risk of NCDs in adulthood.
ABSTRACT Background. The intestinal microbiome is relatively dynamic during the first years of life, becoming relatively stable throughout a lifetime, thus dictating adult life's future health. There are many factors influencing gut microbiome composition, including maternal pre-pregnancy, body mass index (BMI), gestational weight gain (WG), type of feeding, weaning timing, and birth/family environment. Objectives. The study aims to investigate the intestinal microbiome development of infants (ages 0-12 months) and to analyze how prenatal and postnatal factors, including maternal BMI and weight gain during pregnancy, type of feeding, time and type of weaning, and the presence of siblings in the family, could influence the infant gut microbiome composition at one year of age. Methods. 63 dyads were enrolled at Neonatal Unit, IRCCS Policlinico San Matteo, Pavia. Anthropometric parameters were assessed before discharge (T0), at 30 days from birth (T1), at 6 months (T2) and 1 year (T3); validated questionnaires were used to evaluate mother’s dietary habits and physical activity at each time. Mothers were interviewed about family environment and infants feeding/supplementation at each time. For each child a stool sample was collected at each time and analyzed using metagenomics 16s ribosomal RNA gene sequence-based methods. Cluster and correlation analysis were used to assess changes in the microbial composition across different follow-up times. Results. At one years of age, pre- and perinatal variables were not significantly associated with any bacterial taxon, while postnatal variables showed the major contribution in shaping microbiota. Feeding and weaning were the main influencing factors. Conclusion. Our findings highlighted that microbial colonization during the first year of life is likely affected by various factors resembling a simultaneous effect of multiple variables. Mainly, different variables play a significant role at different time. Thus, these data contribute to add evidence concerning the complex multifactorial interaction of GI-microbiota depending on the various stimuli during the early stages of life. This study will provide the starting point for a future prospective and observational study assessing the potential association between maternal diet and life-style with newborns microbiome composition, their influence on childhood obesity development and the associated increased risk of NCDs in adulthood.

The ability of the biological control agents (BCAs) to colonize plant tissues is an important feature involved in microbe-assisted plant protection. Plant-microbe interaction research increased especially in the last decade thanks to technological revolution. Molecular methods and the development of advanced microscopic techniques allow researchers to explore gene expression and localization of beneficial microorganisms within plants. The green fluorescent protein (GFP) and its modified version, enhanced GFP (EGFP), more adapt for expression in mammalian cells and GC-rich actinomycetes like Streptomyces, have been widely used as markers to study gene expression, as well as plant-microbe interactions. Aside fluorescent protein approaches, fluorescence in situ hybridization (FISH) is another frequently used technique to visualize microbial colonization patterns and community composition by application of specific fluorescent probes. Firstly, we transformed five Streptomyces strains, which showed strong inhibition activity against Sclerotinia sclerotiorum, with the EGFP construct by the conjugation method. The conjugation efficiencies varied between the strains, but were comparable to the reference strain. The fitness of transformed strains was similar to wild-type; the transformants maintained similar sporulation, mycelium growth rate, and the ability to produce important secondary metabolites and lytic enzymes. Secondly, two transformed strains, Streptomyces cyaneus ZEA17I, and Streptomyces sp. SW06W, were used to study lettuce colonization dynamics by seed coating method. Their spatio-temporal dynamics were determined in sterile substrate. The strains were consistently recovered from lettuce rhizosphere and inner root tissues up to six weeks. Finally, the colonization pattern of lettuce by Streptomyces cyaneus ZEA17I was examined by both EGFP and FISH approaches combined with confocal laser scanning microscopy (CLSM). For FISH-CLSM analysis, universal bacteria and Streptomyces genus specific probes were used to label S. cyaneus ZEA17I. The consistent presence of the labeled strain at the lettuce root one week after sowing showed that Streptomyces spores could rapidly germinate and produce filamentous mycelium on lettuce. S. cyaneus ZEA17I was detected also on two-week-old roots, indicating the long-term survival ability of this strain in lettuce rhizosphere. Altogether, the antagonistic activity, rhizosphere and root competence showed by the Streptomyces conferred their potential to act as BCA. Further studies on the complex host-pathogen-antagonist interactions will provide additional knowledge to understand the modes and mechanisms of Streptomyces-mediated plant protection.

Les microglies, les macrophages résidents du cerveau, jouent un rôle essentiel dans le développement, le fonctionnement et l'homéostasie cérébrale. Issues de progéniteurs érythromyéloïdes du sac vitellin, elles colonisent le système nerveux central au début de l'embryogenèse, où elles prolifèrent ensuite, se répartissent et puis s'autorenouvellent tout au long de la vie. La voie de signalisation du récepteur CSF-1 (CSF-1R) est essentielle pour la survie et la prolifération des microglies, et ses deux ligands, les cytokines CSF-1 et IL-34, sont produites par l’environnement neural. Au cours du développement, outre une remarquable hétérogénéité cellulaire et transcriptionnelle des microglies, leur distribution dans le cerveau suit un schéma spatio-temporel stéréotypé. Par exemple, des microglies d’un sous-type particulier, appelées microglies associées à des faisceaux d’axones (ATM), forment des hotspots transitoires - une caractéristique conservée à travers espèces. Ces spécificités de colonisation et l’hétérogénéité microgliale ont été associées à des fonctions développementales des microglies. Néanmoins, leur régulation ainsi que la contribution des neurones et d’autres sources de CSF-1, restent encore largement inexplorées. Nous avons effectué une analyse détaillée de la prolifération et distribution des microglies dans le cerveau antérieur murin, et étudié comment cela pouvait être régulée par l'environnement neural, soit par l'activité neuronale ou l’expression de CSF-1. Nous avons mis en évidence deux vagues de prolifération microgliale : une première phase globale et intense pendant l’embryogenèse, et une seconde phase postnatale plus hétérogène. De plus, nous avons montré que les microglies des points d’accumulation sont particulièrement prolifératives. En utilisant l'imagerie à deux photons sur des tranches aiguës de cerveau, nous avons confirmé une prolifération et redistribution locale, mais n'avons trouvé aucune preuve de migration à longue distance. Dans l'ensemble, nos résultats indiquent que la prolifération est un moteur important de la colonisation microgliale et contribue à son schéma hétérogène. En nous concentrant sur le cortex cérébral, nous avons d'abord testé le rôle de l'activité neuronale, connue pour être surveillée par les microglies, lorsqu’elle émerge, pendant la seconde vague de prolifération. Nous avons constaté que différentes perturbations de l'activité neuronale n'avaient pas d’effet fort sur le nombre et la distribution des microglies. Ensuite, nous avons examiné les rôles de CSF-1 grâce à des inactivation conditionnelles dans des populations neurales spécifiques. Nous avons montré que CSF-1 issu des progéniteurs et neurones était essentiel pour la colonisation microgliale embryonnaire : son inactivation dans le cortex entraine une déplétion drastique des microglies dans l’embryogenèse, sans affecter les macrophages des méninges. Plus précisément, CSF-1 a une action dose-dépendante, extrêmement locale et transitoire. En parallèle, nous avons montré que les ATM des hotspots exprimaient Csf-1. Grâce à des mutants conditionnels, nous avons révélé que la production autocrine de CSF-1 contribuait à la prolifération soutenue des ATM, mettant en évidence une contribution duale du CSF-1 neural et CSF-1 microglial dans la régulation de leur distribution au cours du développement. De plus, j’ai participé à la description d’une nouvelle fonction microgliale, associée aux ATM, assurant le maintien de l’intégrité tissulaire au hotspots embryonnaire. De façon plus large, notre étude met en lumière la façon dont les microglies prolifèrent et se distribuent dans le cerveau, ainsi que leur dépendance focale au CSF-1. De plus, notre mutant conditionnel dans le cortex fournit un modèle novateur pour étudier les rôles locaux et spécifiques des microglies pendant le développement prénatal et ouvre la voie à une analyse plus approfondie des contributions relatives des ligands de CSF-1R
Microglia are the central nervous system resident macrophages and the main immune sentinels of the brain. Beyond their immune functions, they play key roles in cerebral development and functioning. These immigrants derive from erythromyeloid progenitors generated in the yolk sac and colonize the brain during early embryogenesis. They further proliferate in situ, distribute within the brain parenchyma and self-renew throughout life. The CSF-1 receptor (CSF-1R) pathway regulates microglial survival and proliferation from embryogenesis up to adulthood, with its two ligands, the cytokines CSF-1 and IL-34, produced by the neural environment. During development, along with a remarkable cellular and transcriptional heterogeneity, microglial distribution follows a stereotypical spatiotemporal pattern. For instance, microglia of a specific subset, called axon-tract associated microglia (ATM), form transient and specific accumulations, or hotspots - a feature conserved across mammalian species. Such pattern of colonization and associated microglial heterogeneity have been linked to specific developmental functions. Yet, how early microglial distribution and heterogeneity are regulated, the potential contributions of neurons and of distinct cellular sources of CSF-1, remain largely to be investigated. Here, we tackled these issues by performing a detailed analysis of microglial proliferation and distribution during mouse forebrain development, and examining how the neural environment may regulate this pattern, either through neuronal activity or CSF-1 expression. We first highlighted the existence of two waves of microglial proliferation: a first global and intense phase during mid-embryogenesis, and a second postnatal phase which intensity and timing vary across forebrain regions. In addition, we found that some transient developmental hotspots of microglia were particularly proliferative. Using two-photon live-imaging on acute brain slices, we confirmed local proliferation and redistribution, but found no evidence of long-range migration. Collectively, our findings indicate that proliferation is an important driver of microglial colonization and contributes to its heterogeneous pattern. Focusing on the cerebral cortex, we first tested during this second wave of proliferation the role of neuronal activity, which emerges at these developmental stages and is known to be monitored by microglia. We found that different perturbations of neuronal activity had no broad effect on microglial numbers and distribution. Next, we examined the roles of CSF-1, using conditional mutants in specific neural populations. Through distinct cre drivers, we showed that CSF-1 from both cortical progenitors and neurons is required for microglial embryonic colonization. More specifically, CSF-1 acts in a dose-dependent manner and has a remarkably local effect, without severely affecting macrophages in the meninges. Consistently, Csf-1 cortical inactivation leads to a drastic absence of microglia only during embryogenesis, supporting a later role of IL-34 as previously reported. In parallel, we examined ATM in the hotspots and observed that they express Csf-1. Using conditional mutants, we revealed that autocrine CSF-1 production by ATM contributes to their proliferation in hotspots. Our findings thus highlight a dual contribution of local neural CSF-1 and microglial CSF-1 in regulating their early developmental distribution. In parallel, I participated in describing a novel function of microglia in the maintenance of tissue integrity at the embryonic ATM hotspot. Altogether, our study sheds light on how microglia proliferate and distribute to colonize the brain as well as on their focal and cell-type dependency on CSF-1. In addition, our conditional cortical mutants provide a groundbreaking tool to study the local and specific roles of microglia during prenatal development and opens the path to further dissect the relative contributions of CSF-1R ligands

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine.
Objective and Hypothesis Methicillin resistant Staphylococcus aureus (MRSA) is currently a major cause of skin and soft tissue infections (SSTI) in the United States. In order to characterize the spread of MRSA in the pediatric population we built a probabilistic, discrete-event, individual-based simulation. Specifically, our model looked at the spread of MRSA in households and at schools to determine if there was a difference in communicability between the two settings. Methods We developed a probabilistic, discrete-event, individual-based model. This model was validated using insurance billing data for skin and soft tissue infections. The first validation trained the model for two years of data, and validated it with the next two years of data. The second method trained the model in one region and validated it in another. Following the validation, the Poisson-bootstrap resampling method was used to find specific values for a contagiousness factor(CF) in households and schools. Results Both methods of validation supported the model with no statistically significant difference. The bootstrap resulted in a CFhousehold of 30.69 (95% CI [29.09, 32.29]) and a CFschool of 0.55 (95% CI [0.46 to 0.64]). Effective reproduction number for the school setting was found to be 0.0015 and 0.06 to 3.04 for households of different size. Conclusion In this study we characterize a marked difference in communicability in the household and at school, which has not previously been shown. The identification of colonization clusters in households can be used to design strategies reduce the disease burden. The model can be used to simulate and predict responses to different interventions.

Haemophilus influenzae is an opportunistic pathogen that forms part of the human nasopharyngeal microbiota. This microorganism is classified into encapsulated and nonencapsulated or nontypeable (NTHi) isolates, depending on the presence of a polysaccharide capsule. Although H. influenzae is a common respiratory commensal, it is also able to cause several infections, especially in patients with comorbidities. The most common respiratory infections in which H. influenzae can be identified as the main etiological agent are exacerbations in patients with Chronic Obstructive Pulmonary Disease (COPD), community-acquired pneumonia (CAP), cystic fibrosis, and otitis media. In addition, this pathogen is also a common cause of invasive infections such as bacteraemia and meningitis. Before the introduction of the conjugate vaccine, H. influenzae serotype b (Hib) was the main cause of meningitis in children under five years. However, effective childhood vaccination has caused a dramatic reduction in Hib and allowed the expansion of NTHi, which is becoming more relevant in both respiratory and invasive infections. In this thesis, we studied three different aspects of the epidemiology of NTHi since the introduction of the vaccine. Our study focused on molecular genotyping, antimicrobial resistance and adhesion and biofilm formation of NTHi isolates from healthy children and from adult patients with CAP, COPD and invasive diseases. In the first part of this thesis, we set out to characterize the NTHi populations that are involved in adult infections in Bellvitge hospital. Furthermore, as humans are the only reservoir of NTHi, we aimed to identify the oropharyngeal carriage rate in healthy children attending day care centres in Oviedo. The aim of the second part of this thesis was to determine the antimicrobial susceptibility profile of clinical NTHi isolates, placing emphasis on the molecular characterization of B-lactam and fluoroquinolone resistance, the main antimicrobials used in the treatment of NTHi infections. The last part of this thesis focused on adhesion and biofilm formation. Biofilm is one of the mechanisms that microorganisms have developed in order to protect themselves and survive in hostile environments. Once the biofilm structure is formed, it is difficult to eliminate and, as a consequence, biofilm-associated infections commonly show recurrent symptoms. Although biofilm formation by NTHi remains controversial, biofilm-like structures have been observed in middle-ear mucosa in experimental chinchilla models of otitis media. Taken together, all the studies discussed in this thesis can improve our understanding of the clinical epidemiology of NTHi populations since the introduction of vaccination and of the mechanism of biofilm formation in clinical isolates of this microorganism.
Haemophilus influenzae és un patogen oportunista que forma part de la microbiota nasofaríngia humana. Aquest microorganisme es classifica en soques capsulades i no capsulades o no tipables (HiNT) depenent de la presència d’una càpsula polisacarídica. Tot i que H. influenzae és un comensal respiratori comú, posseeix la capacitat de causar diferents infeccions, especialment en pacients amb malalties de base. Les infeccions respiratòries més freqüents causades per H. influenzae són les exacerbacions agudes en pacients amb Malaltia Pulmonar Obstructiva Crònica (MPOC), pneumònia adquirida en la comunitat (PAC), exacerbacions en pacients amb fibrosis quística i otitis mitjana. A més, aquest patogen és també una causa freqüent de malalties invasives com bacterièmia i meningitis. Abans de la introducció de la vacuna conjugada, H. influenzae serotipus b (Hib) fou la causa principal de meningitis en nens/es menors de cinc anys d’edat. No obstant, l'efectiva vacunació ha causat un dramàtic descens del Hib permetent l’expansió dels HiNT, que s’estan convertint en un patogen més rellevant tant en infeccions respiratòries com en infeccions invasives. Els objectius plantejats en aquesta tesis, foren l’estudi de tres aspectes de la epidemiologia dels HiNT en l'etapa posterior a la introducció de la vacuna en Barcelona: la genotipificació molecular, la resistència antibiòtica i la formació de biofilm en soques d’HiNT aïllades de nens/es sans i de pacients adults amb PAC, MPOC i malalties invasives. L’objectiu de la primera part d’aquesta tesis fou caracteritzar les poblacions d’HiNT involucrades en les infeccions en pacients adults de l’hospital de Bellvitge així com la determinació de la freqüència de colonització orofaríngia d’HiNT en nens/es sans que van a llars d’infants en Oviedo. L’objectiu de la segona part de la tesis fou determinar els perfils de susceptibilitat antibiòtica dels aïllats clínics d’HiNT, emfatitzant en la caracterització molecular de la resistencia a B-lactàmics i fluoroquinolones, ja que són els antibiòtics més utilitzats en el tractament de les infeccions per HiNT. L’última part de la tesis està enfocada a l’estudi de l’adhesió i la formació de biofilm. El biofilm és un dels mecanismes que els microorganismes han desenvolupat per a la protecció i supervivència en ambients hostils. Una vegada l’estructura del biofilm està formada és molt difícil d’eliminar i, com a conseqüència, les infeccions associades a biofilm presenten símptomes recurrents. Tot i que la formació de biofilm per HiNT roman controvertida, estructures tipus biofilm s’han observat en la mucosa de l’oïda mitjana en models experimentals d’otitis mitjana en xinxilla. En conjunt, tots els estudis discutits en aquesta tesis contribueixen a ampliar el coneixement de la epidemiologia clínica, la resistència antibiòtica i la formació de biofilm de les poblacions d’HiNT en un període posterior a la introducció de la vacuna.

Diabetes is used as a lens through which to examine colonial processes of dispossession, assimilation, and economic change in the coastal First Nations community of Gitxaala, in BC, Canada. Diabetes is a worldwide epidemic disproportionately affecting indigenous peoples. Social determinants of diabetes in Gitxaala are explored ethnographically, focusing on diet change and food security. Diet is framed as a 'choice' by government agencies, but economic factors, food availability, and food preferences all delimit the foods consumed in Gitxaala. The importance of traditional foods for subsistence and cultural identity is explored. A history of integrating and then relying upon colonial foods is traced through a history of economic change. Current economic hardship limits both access to nutritious store-bought foods and the harvesting of traditional foods; although many community members prefer traditional foods, starchy processed foods are the most readily available and affordable. Colonial attempts to assimilate taste preferences, including relief rations and residential schools, have had lasting effects. Childhood exposure to traditional foods, or to sugary foods, impacts adult diet and health. Intergenerational attitudes to foods are changing, and Gitxaala youth are consuming an increasing amount of sugary foods. Access to traditional food resources is impacted by colonial policy, community avenues of food distribution, and traditional ecological knowedge. Expropriation and commercialization of resources, particularly the fishery, have severely impacted access to important resources, contributing to community-level food insecurity. While the practice of selling harvested foods for cash within the community is growing, food distribution along family lines remains critical for house-hold level food security and community health. The transmission of traditional ecological knowledge about food ensures healthy eating in the future. Although this process was interrupted by the residential school experience, the community is initiating new ways to maintain this aspect of Gitxaala identity. In Gitxaala, health is understood as holistic. Biomedical understandings of and treatments of diabetes are insufficient for true healing, which must also occur on the community and ecological levels. While colonial practices have been detrimental to food security and risk for diabetes in Gitxaala, certain traditional practices maintain healthy eating and contribute to community health.
Arts, Faculty of
Anthropology, Department of
Graduate

Demographic expansion and colonization of new territories by agriculturalists is characteristic of Neolithic transitions around the world. The central San Juan region of the northern Southwest was first colonized by ancestral Pueblo farming populations during the Basketmaker III period (A.D. 500-725) after nearly 1000 years of avoidance by early farmers during the previous Basketmaker II period (500 B.C.-500 A.D.). This thesis examines the social processes that contributed to this demographic shift through historical reconstruction and an assessment of architecture and ritual features during colonization. These analyses demonstrate that what began as a socio-political boundary between culturally distinct populations was transformed by historical events and social adaptation into a multi-cultural colonization frontier organized around burgeoning social institutions.

Doctor of Philosophy
Department of Plant Pathology
James Stack
The trade of food, plant, and animal products has increased the worldwide movement and establishment of exotic pathogens with dramatic negative impacts on plant systems. Fusarium proliferatum is a broad host-range pathogen and among the most common maize pathogens globally. It is often seed-borne and symptomless in maize, making it a high risk for introduction in maize and other grains. Considering the global distribution of maize and the wide host range and production of mycotoxins by F. proliferatum, a better understanding of its life history is needed. To provide markers for tracking F. proliferatum in laboratory experiments, strains of F. proliferatum were transformed to express a green fluorescent protein (GFP). Active dispersal (at least 1.5cm at 25°C and -50mb soil matric potential) and colonization of organic matter in nonsterile field soil was demonstrated in soil microcosms. Fusarium verticillioides is commonly isolated from maize seed also colonized by F. proliferatum. A red fluorescent (mRFP) F. verticillioides transformant was developed to study competition with F. proliferatum. For quantification in host tissues, a TaqMan multiplex qPCR protocol was developed using primer and probe sets targeting fragments of the green and red fluorescence genes to detect F. proliferatum and F. verticillioides, respectively. Prior colonization of maize tissues by F. verticillioides (p=0.6749) and other seed-borne microorganisms (p=0.1910) did not affect subsequent colonization by F. proliferatum. Genotyping-by-sequencing (GBS) was used to identify genetic markers in F. proliferatum. Primer sets based GBS markers were designed to allow detection of specific isolates in field experiments. F. proliferatum populations were characterized from maize seed prior to planting and again after harvest. End-point PCR identified F. proliferatum isolates containing the GBS marker. AFLP-fingerprinting indicated that 23 of the 817 F. proliferatum isolates contained the molecular marker and were genetically related to the original isolate. Based on the subclade and percentage similarity in UPGMA phylogenetic trees, and the population grouping observed in STRUCTURE and Principal Coordinate Analysis, these isolates could have a single origin and be clonal. Understanding the life cycle of F. proliferatum is critical for learning more about the risk of introducing seed-borne exotic isolates into new environments.

Doutoramento em Biologia
Na colonização de um novo substrato por macroinvertebrados bentónicos, os colonizadores iniciais, maioritariamente provenientes de habitats adjacentes, podem estabelecer-se quer por meio de assentamento e recrutamento larvar, quer por dispersão de organismos adultos. Estes colonizadores respondem não só a propriedades físicas do substrato, reflectindo a sua capacidade e/ou necessidade de explorar novos recursos, mas também à presença de outros indivíduos, iniciando a cadeia de interacções bióticas que caracterizam a sucessão ecológica. O padrão temporal dos colonizadores iniciais pode determinar o decorrer da sucessão da comunidade não só pela ocorrência de fenómenos de inibição e facilitação, mas também pelo efeito da contínua chegada de novos colonizadores. Por conseguinte, a dinâmica inicial de sucessão é fortemente condicionada por flutuações das variáveis ambientais. No entanto, à medida que a sucessão avança, a instabilidade inicial vai paulatinamente dando lugar a uma situação de quasi-equilíbrio, na qual a dinâmica da comunidade passa a ser determinada por características dos ciclos de vida e por mecanismos de dominância das espécies que a compõem. A natureza dinâmica dos ecossistemas costeiros, como a Ria de Aveiro, dita a necessidade de estudar os processos de colonização e sucessão em condições ambientais muito específicas, de modo a poder determinar as tendências gerais de recuperação do ecossistema depois de uma perturbação, tanto ao nível das populações como ao nível das comunidades. Neste sentido, e com o objectivo de aprofundar o conhecimento dos mecanismos que regem ditos processos em comunidades macrobentónicas de substratos duro, o presente trabalho baseou-se numa série de experiências de campo com substratos artificiais (AS), levadas a cabo em dois pontos da Ria de Aveiro com condições hidrodinâmicas contrastantes. Num estudo preliminar de curta duração, réplicas de quatro tipos distintos de AS foram submergidas nos pontos experimentais e posteriormente recolhidos em três ocasiões durante um período de 6 semanas. Num estudo posterior de longa duração (14 meses), levou-se a cabo uma experiência de colonização em relva artificial, nos mesmo pontos experimentais. Obtiveram-se duas séries de amostras: 1) ‘Monthly’ em que réplicas submergidas num determinado mês, foram colhidas no mês seguinte, durante 14 meses; 2) ‘Start’ em que réplicas submergidas no início do período experimental, foram colhidas cada mês ao longo de 13 meses. Durante todo o período experimental, as principais variáveis ambientais foram monitorizadas mensalmente, através de medições efectuadas nos mesmos dias das amostragens, e sazonalmente através de medições efectuadas durante ciclos de 24 horas. A amostragem com substratos artificiais, revelou ser um método bastante efectivo na avaliação da diversidade de macrofauna bentónica infralitoral na Ria de Aveiro. Ao longo deste trabalho, foram colhidos um total de 440710 indivíduos pertencentes a 143 taxa. Observou-se uma grande assimetria na composição faunística dos dois pontos experimentais: a densidade máxima registada no ponto confinado foi de quase dois milhões de ind.m-2 , para um número máximo de taxa identificados de 31; no ponto exposto a densidade máxima não chegou a meio milhão de ind.m-2, mas foram identificados 110 taxa. De um modo geral, a estrutura das comunidades colonizadoras foi determinada pela acção negativa da complexidade dos AS, pelo efeito conjunto e a pequena-escala da heterogeneidade e variáveis ambientais, e pelo grau de confinamento dos pontos de amostragem. No ponto experimental mais exposto, os diferentes tipos de AS usados desenvolveram comunidades bentónicas muito diferentes e com dinâmicas de sucessão distintas, mas em todo o caso pouco abundantes, com elevada diversidade e altas taxas de renovação. No ponto mais confinado, todos os tipos de AS desenvolveram comunidades dominadas por populações extremamente densas de Corophium acherusicum, apresentando tendências semelhantes de sucessão e baixas taxas de renovação. Os mecanismos iniciais de sucessão mais relevantes, parecem ter sido conduzidos por fenómenos de inibição no ponto mais confinado e de tolerância no ponto mais exposto. O substrato que melhor desempenho mostrou durante o estudo preliminar foi a relva artificial. No estudo de longa-duração, as comunidades com um mês de idade mostraram uma componente sazonal muito marcada em ambos pontos experimentais, em resposta a flutuações sazonais da temperatura e salinidade da água, reflectindo por um lado a flutuação temporal da disponibilidade de indivíduos colonizadores e por outro, a ocorrência de relações interespecíficas pós-colonização. No entanto, as principais diferenças espaciais detectadas no estudo preliminar mantiveram-se nesta segunda fase. No ponto mais exposto as comunidades desenvolveram-se em dois passos: um period inicial de colonização nos primeiros 2-3 meses, seguido do período de sucessão conducente a uma estabilização da estrutura da comunidade. A dinâmica de colonização inicial foi determinada pela flutuação sazonal e competição interespecífica de cinco espécies de mobilidade reduzida e perfil essencialmente oportunista: C. acherusicum, C. acutum, Aora gracilis, Pomatoceros triqueter and Mytilus galloprovincialis. A actividade destes recrutas iniciais promoveu o posterior estabelecimento de espécies com preferências tróficas mais amplas. Este aumento da complexidade trófica foi acompanhado por uma estabilização do quociente colonização/emigração entre os três e os seis meses de colonização. As comunidades no equilíbrio foram condicionadas fundamentalmente por processos autogénicos, como a competição não-exclusiva. No ponto mais confinado, o padrão temporal das comunidades foi sobretudo determinado por alternâncias na dominância de três espécie altamente abundantes (C. acherusicum, Leptocheirus pilosus e Polydora sp.) provocadas por mecanismos de exclusão competitiva, despoletados por variações sazonais na disponibilidade de colonizadores e de fontes de alimento e protecção.
In the colonization of an open space by benthic invertebrates, early colonists, which are likely to be produced from the adjacent established community, may come either from larval settlement and recruitment or from adult dispersal. During settlement they respond not only to physical properties of the substrate, reflecting their ability and/or need to explore newly available resources, but also to the presence of concurrent establishers, triggering the complex net of biotic interactions of ecological succession. The temporal pattern of early colonization may dictate the progress of assemblage succession not only through intraassemblage post-colonization processes such as inhibition and facilitation, but also through the effect of the continuous arrival of colonists. Hence, in subtidal benthic assemblages, early successional dynamics is strongly dependent on patterns of environmental variability. Initial highly variable assemblages may though be gradually replaced by more stable ones, where life-history traits and dominance will be the major determinants of assemblage dynamics. The dynamic nature of coastal ecosystems, such as Ria de Aveiro, dictates the need to develop studies of colonization and succession under specific habitat conditions, in order to determine the general patterns of recovery following disturbance at community and population levels. As so, in order to understand the mechanisms behind those processes in hard-bottom macrofaunal communities of Ria de Aveiro, a set of experiments using artificial substrates (AS) were carried out at two sites with contrasting hydrodynamics. A short-term pilot experiment was conducted, where replicates of four types of AS were deployed at the experimental sites and sampled in three occasions over a period of six weeks. Afterwards, a long-term colonization experiment using artificial grass as AS was carried out at the experimental sites. Two series of samples were obtained: 1)’Monthly’ series –replicates deployed each month were collected in the following month, over a period of 14 months; 2)’Start’ series –replicates deployed at the beginning of the experiment were sampled each month over a period of 13 months. During the experimental period, the main environmental parameters were monitored through monthly records and seasonal 24 hour-cycles. The use of artificial substrates proved to be a very effective way to evaluate the diversity of hard-bottom assemblages in Ria de Aveiro. A total of 440710 individuals ascribed to 143 taxa were collected. There was an important site asymmetry in assemblage composition: the maximum density recorded in the confined site was about two million ind.m-2, while in the exposed site it did not reach the half-million ind.m-2; moreover, a maximum of 31 taxa were recorded in the confined site while 110 were recorded in the exposed site. Overall, the structure of the colonist assemblages was determined by the negative effect of AS complexity, the environment-dependent effect of smallscale substrate heterogeneity and by the general degree of confinement. of the sampling sites. In the exposed site, each AS type yielded distinct high diversity and low abundance assemblages, each of them with its particular successional dynamics, but always with high turnover rates. In the confined site, all AS yielded assemblages dominated by extremely dense populations of Corophium acherusicum and showed similar trends of successional dynamics marked by low turnover rates. The relevant early successional mechanisms identified seemed to be majorly driven by inhibition and tolerance in the confined and exposed site, respectively. During the pilot experiments, artificial grass showed the best performance as experimental AS. The long term-study allowed to develop a first approach in the explanation of the mechanisms behind colonization and succession of subtidal hardsubstrates, in Ria de Aveiro. At both sites the development of 1-month assemblages showed a strong seasonal component, associated with seasonal fluctuations in water temperature and salinity, which reflected the temporal fluctuation of colonist availability and short-term post-colonization interactions. However, the main site differences identified in the pilot experiments were confirmed to occur in the long-term experiment. In the exposed site the development of macrofaunal assemblages, occurred in two steps: an initial colonization and early succession period during the first 2-3 colonization months followed by the successional period of assemblage structure stabilization. Early colonists were majorly mobile amphipods, although shortterm post-colonization dynamics was determined by seasonal fluctuations and inter-specific competition of five low mobility species with an opportunistic profile: C. acherusicum, C. acutum, Aora gracilis, Pomatoceros triqueter and Mytilus galloprovincialis. The activity of these early settlers facilitated the further recruitment of species with a wider trophic preferences. The increase in the trophic complexity of the assemblages was accompanied by a stabilization of the ratio colonization/emigration, somewhere between the three to six months of colonization. The quasi-equilibrium assemblages were mainly ruled by autogenic processes, such as non-exclusive competition. In the confined site, the temporal pattern of the assemblages was primarily dictated by shifts in the dominance of three highly abundant taxa: C. acherusicum, Polydora spp. and Leptocheirus pilosus. These shifts were mostly the result of competitive exclusion, triggered by seasonal variations in the availability of both colonists and food/shelter resources. Hence, assemblages at this confined site seem to maintain a permanent “late colonization” or “early succession” stage, characterized by low trophic complexity.

Mercury (Hg) is a toxic heavy metal that poses significant human and environmental health risks. Mineral-associated Hg is the largest reservoir of Hg in the environment where it can account for nearly 60% of the global Hg mass inventory. A large fraction of this pool is comprised of mercury sulfide (HgS) minerals, including metacinnabar (beta-HgS). HgS minerals have long been considered insignificant sources of Hg to aqueous or atmospheric pools in all but severely acidic environments due to their low solubility and slow abiotic dissolution kinetics. Little previous work has been conducted investigating the bacterial colonization of HgS minerals and the potential role of these mineral-associated communities in impacting the mobility of mineral-hosted Hg. To address this gap in knowledge, the studies within this dissertation employed a combination of field- and laboratory-based methods. Using culture-independent techniques, this work revealed that sulfur-oxidizing bacteria can extensively colonize metacinnabar within aerobic, near neutral pH, creek sediments, suggesting a potential role for chemolithotrophic bacteria in metacinnabar weathering. Within laboratory incubations, the dominant bacterial colonizer (Thiobacillus thioparus), induced extensive release and volatilization of metacinnabar-hosted Hg. These findings expose a new pathway for metacinnabar dissolution and point to mineral-hosted Hg as an underappreciated source of elemental Hg that may contribute to global atmospheric Hg budgets. In addition, this work elucidates the importance of thiosulfate, a major intermediate sulfur species in the environment, in stimulating metacinnabar dissolution. Therefore, the work within this dissertation shows that authigenic HgS minerals are not merely a sink for Hg within non-acidic natural environments and instead are a source of dissolved and gaseous Hg. This work provides critical information for predicting the transport of Hg in the environment and for developing appropriate management and remediation strategies for Hg-contaminated systems.
Engineering and Applied Sciences

The present study introduces the phenomenon of triple colonization of women in the fiction of the ex-colonies of Britain, the African continent, and the Indian Subcontinent. The women of these postcolonial countries have been suffering from multiple layers of oppression since the beginning of the colonial phase. They faced the wrath of colonisers on their bodies and mind, and then, after the departure of the master, they had to endure the suffocating ferocity of their own patriarchy. But the various aspects of female agony did not stop at this point, as in the phase of Triple Colonization they are now receiving disgrace by their feminist cronies. My term Triple Colonization suggests the existence of the facet of a complex state of affairs for postcolonial women: the undercover and covert exploitation of women at the hands of their own overtly self-styled sympathisers, the feminist authors. This research, while opposing the popular view about the selected postcolonial feminist fiction writers and their so-called realistic cum reformist fiction, surveys how the female body becomes a victim of humiliation and visual feast due to the voyeuristic textual discourse of the very texts. While utilising Wolfgang Iser’s concepts on imagery analysis and current European theories on anti-pornography, the study sets its boundaries at the intersections between postcolonialism and feminism in the fiction of postcolonial countries. I scrutinize the feminist fiction of these regions to investigate the disparity between the rhetoric and representation of feminist stance in the postcolonial context. Also, the research argues that the selected African authors do not show such voyeuristic, anti-feminist trends in their fiction and no disparity between their rhetoric and representation can be seen. Hence, they can serve as models for postcolonial feminist activism in fiction writing.

Indonesia, a vast archipelago nation and home to a wide range of cultural, linguistic and genetic diversity, has been a navel of intercultural and interregional interaction between the Asian and the Pacific worlds since prehistoric times. By analyzing the genetic profile of Indonesian people across the archipelago, this dissertation aims to elucidate the colonization history of Indonesia and to assess the effect of social practices on the Indonesian gene pool. Genetic diversity has revealed the complex settlement history of the Indonesian archipelago, starting from the initial colonization of Indonesia ~50 kya, multiple migrations by hunter-gatherers from mainland Asia during the Paleolithic era, followed by a major Neolithic expansion of Austronesian-speaking farmers from a putative homeland of Taiwan, and historic era migrations that involved several foreign invasions via trading and the spread of major religions. The survival of older lineages in western and eastern Indonesia showed that these later expansions into the archipelago did not replace the gene pool of the previous inhabitants. Although most Indonesian communities today practice patrilocality, which is supported by genetic diversity and population structure analyses, matrilineal descent systems are thought to have dominated ancestral Austronesian societies. Preserving a rich Austronesian cultural heritage, such as matrilocal marriage practices, has particularly affected the genetic diversity and population structure of Timor. The dominance of Asian female lineages is apparent on the X chromosome compared to the autosomes, suggesting that female migrants played a leading role during the period of Asian immigration into Timor. Matrilocality may have been a driving force behind this admixture bias during the Austronesian expansion. This finding provides support for an Austronesian `house society' model in which the Austronesian expansion led to the dispersal of matrilocal societies with small numbers of neighboring non-Austronesian males marrying into Austronesian matrilocal, matrilineal houses. This study has revealed that the colonization history of Indonesia does not seem to comprise merely a Melanesian substratum with a single expansion of Austronesian speakers, yet rather involves multiple waves of human migration, coupled with an extensive admixture process.

Forest management practices have changed the over-all structure of the Fennoscandian forest landscape resulting in a lack of suitable substrates for many wood-inhabiting species. The objectives of this thesis was to describe the colonization patterns of wood-inhabiting fungi, including the potential role of beetles as dispersal vectors, on different types of dead wood substrate and assess the importance of active measures in the forest landscape in order to restore biodiversity i.e. to increase the amount of dead wood and the use of restoration fire. The results clearly demonstrate the importance of restoration fire for wood-inhabiting fungi in a dry Pinus sylvestris forest. The general pattern for the majority of the species was a drastic decline the first two years after fire. However, after four years most of the species had recovered and were frequently found on logs strongly affected by the fire. The early fungal colonization patterns on fresh experimental Picea abies logs revealed no differences between managed forest stands and stands associated with nature reserves. After five years the species assemblage on the experimental logs was affected by stand age, forest site type, and distance to forest reserves. However, very few red-listed species colonized the logs in spite of being fairly common in the reserve stands. We conclude that the experimental period of only five years was too short to fully evaluate the possibilities to use experimental logs for threatened and red-listed species. We assessed the colonization patterns of different fungal functional groups based upon their different nutritional strategies namely mycorrhizal, saprotrophic on litter and humus, saprotrophic on wood causing white rot, and saprotrophic on wood causing brown rot. The results show that the fungal community undergoes a marked change in dominant nutritional strategies during the initial stage of the colonization process both after fire disturbance and on fresh un-colonized experimental logs. To which extent, saproxylic beetles are involved as passive or active vectors in the dispersal and colonization of wood-inhabiting fungi occurring on dead wood is poorly understood. The results clearly showed that some beetle species do discriminate between different fungal substrates and in particular, the bark beetle Dryocoetes autographus showed significant preference for wood with Fomitopsis rosea mycelium.

Abstract Mycorrhizal symbiosis is generally advantageous for plants in nutrient-poor soils. Arcto-alpine areas are relatively nutrient-poor, but abundantly inhabited by non-mycorrhizal species. Possibly, mycorrhizal symbiosis is not favoured due to the harsh climatic conditions and the short growing season, which constrain the photosynthetic gain and growth of the arcto-alpine plants. This hypothesis was theoretically evaluated by assuming that optimal mycorrhizal colonization maximizes the net carbon gain of the host plant. In addition, the prevalence of arbuscular mycorrhizal (AM) and dark-septate endophytic (DSE) fungi along an altitudinal gradient was studied in the field, and their effects on the plant performance were tested in the laboratory. In the model, the photosynthetic nutrient use efficiency (PNUE) had a key role in determining whether mycorrhizal strategy would be optimal for the plant net carbon gain. The model generated several colonization patterns depending on possible changes in PNUE and soil nutrient concentrations along altitudinal gradients. Field studies indicated that species-level colonizations do not yield a consistent pattern along the altitude except for fine endophyte, which increased along an altitudinal gradient. In a high-alpine field site root fungal colonizations were rare. Seasonal shifts in colonizations in low-alpine conditions were not found. DSE fungi were common root-associates in the field. In the laboratory, AM had a positive impact on the performance of Gnaphalium norvegicum at 15°C, but not at 8°C. DSE-inoculation did not colonize the roots, but it had a positive impact on seedling performance, which may be due to the saprophytic activity of the fungus in the substrate. Additionally, mycorrhizal inoculum was found to decrease the performance of a non-mycorrhizal plant in a competition experiment. Species-level mycorrhizal colonization patterns may differ from community-level pattern along altitudinal gradients and the relative abundance of different fungal symbionts may change along with the altitude. The performance of mycorrhizal plants in high-alpine conditions may be decreased due to several factors e.g. low temperature constraints on plant and fungal physiology and allocation, soil disturbances and low availability of inoculum. Climatic constraints for plant photosynthesis may thus affect the mycorrhizal colonization patterns in arcto-alpine conditions, but are not necessarily the primary cause for lower performance of mycorrhizal plants at higher altitudes.

The thesis is an in-depth exploration of the role privilege plays in subverting social justice, despite 'best intentions', within day-to-day life and within conflict studies discourse and practice. The thesis explores the constituting dynamics within privilege, how these dynamics become 'socially acceptable notions of common sense in everyday life', and how such common sense undermines social justice at every turn, despite best intention. A central component explored is the exploitation of the desire 'to be'. The exploitation of the desire to be, combined with enticement toward anticipated or real privilege, is central in driving consent to even the most subtle forms of everyday coercion from 'ordinary' hierarchy to acceptance of and participation in the violence of totalitarian regimes. The author traces this dynamic across a wide range of conflicts and contexts. The thesis challenges those in conflict studies and peace practice to rigorous self-critical reflection in action in context.

Campylobacter jejuni is a major cause of bacterial gastroenteritis in the developed world; however, many aspects of its biology remain poorly understood, including its colonization of the mucus layer lining the gastrointestinal tract. In this study, we utilized microarray transposon tracking to compile a list of 195 genes essential for the growth of C. jejuni in vitro under microaerophilic conditions. Then we characterized C. jejuni growing in an extracted intestinal mucus medium. We found that C. jejuni will grow efficiently in a medium comprised of either chick and piglet intestinal mucus, and that these media have a dramatic impact on its transcriptome. Within the genes identified as differentially expressed during growth in a mucus medium, we identified a single operon, (cj0481-cj0490), which we have subsequently characterized as being responsible for both the uptake and metabolism of L-fucose. This represents the first observation of carbohydrate metabolism by the otherwise asaccharolytic C. jejuni. We further found that the inability to utilize L-fucose puts C. jejuni at a competitive disadvantage when colonizing the piglet intestine, but not the chick cecum. Finally, we examined C. jejuni’s ability to utilize mucins as a carbon source while growing within the mucus layer. We found that despite mucins being a major source of L-fucose and amino acids within the intestine, C. jejuni has a minimal ability to degrade and utilize mucins on its own. However, close proximity to mucolytic bacteria within the microbiota of the intestine, allows for increased C. jejuni growth. Together, this paints the picture of an organism that is well adapted to survival within the mucus lining of the intestine and establishing itself as part of the intestinal microbiota.

This dissertation reconstructs the gender and sexuality structures of Indigenous Illinois society in order to explain how these structures, including the Illinois recognition of four genders, guided French colonization in the seventeenth and eighteenth centuries. I argue that while the Illinois has considerable military, economic, and diplomatic power throughout their relationship with the French, French colonists established a stable foothold in Illinois by mobilizing their knowledge of Illinois gender and sexuality. At the same time, the Illinois drew on French and Native gender practices to contain French expansion and behavior. From this understanding of Illinois gender structures, it becomes clear that the Illinois-French relationship was not that of a parent to a child, as the French then cast it, but rather a marriage. As such, this dissertation plots French colonization in terms of Native marriage, which recognizes both that the French were a colonizing force and that the Illinois had considerable power throughout the encounters.

This dissertation introduces assembly of spherical particles as a novel topography-based anti-biofouling coating. It also provides new insights on the effects of surface topography, especially local curvature, on cell–surface and cell–cell interactions during the evolution of biofilms. I investigated the adhesion, colonization, and biofilm formation of the opportunistic human pathogen Pseudomonas aeruginosa on a solid coated in close-packed spheres of polystyrene, using flat polystyrene sheets as a control. The results show that, whereas flat sheets are covered in large clusters after one day, a close-packed layer of 630–1550 nm monodisperse spheres prevents cluster formation. Moreover, the film of spheres reduces the density of P. aeruginosa adhered to the solid by 80%. Our data show that when P. aeruginosa adheres to the spheres, the distribution is not random. For 630 nm and larger particles, P. aeruginosa tends to position its body in the confined spaces between particles. After two days, 3D biofilm structures cover much of the flat polystyrene, whereas 3D biofilms rarely occur on a solid with a colloidal crystal coating of 1550 nm spheres. On 450 nm colloidal crystals, the bacterial growth was intermediate between the flat and 1550 nm spheres. The initial preference for P. aeruginosa to adhere to confined spaces is maintained on the second day, even when the cells form clusters: the cells remain in the confined spaces to form non-touching clusters. When the cells do touch, the contact is usually the pole, not the sides of the bacteria. The observations are rationalized based on the potential gains and costs associated with cell-sphere and cell-cell contacts. I concluded that the anti-biofilm property of the colloidal crystals is correlated with the ability to arrange the individual cells. I showed that a colloidal crystal coating delays P. aeruginosa cluster formation on a medical-grade stainless-steel needle. This suggests that a colloidal crystal approach to biofilm inhibition might be applicable to other materials and geometries. The results presented in appendix 1 suggest that colloidal crystals can also delay adhesion of Methicillin resistant staphylococcus aureus (MRSA) while it supports selective adhesion of this bacterium to the confined spaces.
Ph. D.

This study analyses the wolf (canis lupus) and human relations in Swedish landscapes. By addressing the change of ideas influencing land use and nature management during the time when the wolf was considered functionally extinct, two parallel realities appear that is shown to be something that the participants in this study relates and recognizes as their reality. These realities in turn can be understood against the background of environmental philosophy and the anthropocentric and eco-centric view of nature and the instrumental and intrinsic value that the nature may carry. Life story interview is used as a method to grasp these details in an individual’s perception of the wolf and nature. Since the wolf is considered to be as a division between rural and urban people, the study also analyses how people sharing the space with the wolf is referring to these dichotomies and how they identify with their surroundings. With contradictory, data a new way of conceptualize this is suggested: that urbanity and rurality is something that could be seen as performativity, something that you do rather than something that you are (Butler 2007). One might express identification with rural space but have an urban performativity i.e. working, living part-time, influenced by ideas represented in urban lifestyles. While the rural performativity is mirrored by living, working and sharing the ideas of how that landscape is used.

Thesis (Ph. D.)--University of Oregon, 2001.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 213-217). Also available for download via the World Wide Web; free to University of Oregon users.

Species invasion and range shifts are widely reported and facilitate novel interactions among potential competitors in plant and animal communities worldwide. However, predicting which novel interactions will result in the extirpation of subordinate competitors is challenging. Coexistence versus extinction as alternative outcomes of competition between resident and colonizing species may arise due to (1) variation in interaction strength, (2) change in other demographic drivers more influential than those linked to competition, or (3) differences in the extent to which resources are equitably partitioned between competitors, which may in turn depend on the spatial scale examined. To date, however, empirical studies suggest these factors rarely align to cause the competitive exclusion of native species. I used a combination of field experiments and demographic analyses to test the hypothesis that colonizing fox sparrows (Passerella iliaca) have caused the 0.6% per year decline of a song sparrow (Melospiza melodia) population resident on Mandarte Island, BC, Canada. Several lines of evidence indicate that interspecific competition for winter food has: a) reduced survival in juvenile song sparrows after colonization by fox sparrows in 1975, b) led to an inverse relationship between juvenile song sparrow survival and fox sparrow population size, c) excluded song sparrows from high-quality foraging sites in winter via consistent behavioural dominance by fox sparrows and complete overlap of fox and song sparrow preference for local seeds, despite d) no evidence of competition for breeding territories or nesting habitat. My results suggest that in the absence of rapid ecological or evolutionary shifts in niche dimension, song sparrows will likely be extirpated from Mandarte Is., thus demonstrating that competitive exclusion of native species can occur when interactions are strong and resources are not easily partitioned.
Forestry, Faculty of
Graduate

The modeling of trees is challenging due to their complex branching structures. Three different ways to generate trees are using real world data for reconstruction, interactive modeling methods and modeling with procedural or rule-based systems. Procedural content generation is the idea of using algorithms to automate content creation processes, and it is useful in plant modeling since it can generate a wide variety of plants that can adapt and react to the environment and changing conditions. This thesis focuses on and extends a procedural tree generation technique that uses a space colonization algorithm to model the tree branches' competition for space, and shifts the previous works' focus from realism to fantasy. The technique satisfied the idea of using interaction between the tree's internal and external factors to determine its final shape, by letting the designer control the where and the how of the tree's growth process. The implementation resulted in a tree generation application where the user's imagination decides the limit of what can be produced, and if that limit is reached can the application be used to randomly generate a wide variety of trees and tree-like structures. A motivation for many researchers in the procedural content generation area is how it can be used to augment human imagination. The result of this thesis can be used for that, by stepping away from the restrictions of realism, and with ease let the user generate widely diverse trees, that are not necessarily realistic but, in most cases, adapts to the idea of a tree.