The brown macroalgae Fucus radicans is endemic to the Baltic Sea, but little is known about this newly described species. This thesis investigates the ecology and role of F. radicans within the species poor Baltic Sea ecosystem. The thallus of F. radicans had a more complex structure but was smaller than F. vesiculosus, the other important foundation species with which it grows in sympatry at several sites. The variability of the associated flora and fauna communities of these two Fucus species, however, was explained by the thallus size, not the complexity. Comparisons between the populations of F. radicans in the Bothnian Sea with those in Väinameri Sea on the Estonian coast, showed that the Estonian thalli were smaller, less complex and lacking the numerous adventitious branches which occur extensively in the Bothnian Sea populations. The distribution of F. radicans in Sweden is limited to the Bothnian Sea coast. The low salinity at the northern limit prevented successful fertilization, while increased salinity did not restrict F. radicans but improved its reproductive success. The southern distribution limit was instead shown to be negatively impacted by a combination of grazing and competition. The asexual reproduction through settling of detached fragments was favoured by high light levels and high temperature in laboratory conditions. Re-attachment occurred by basally formed rhizoids but settling also occurred through a calcium-rich substance, seemingly secreted by the fragment. Genetic spatial distribution of F. radicans showed a dominance of a few widespread clones both within and between sites with an intermingled rather than clustered pattern. The extensive female clone, common in most sites, is most likely old and several clonal lineages have derived from her.  Although more clearly expressed in the clonal populations, the macroscopic sexual dimorphism discovered appears to be a species specific trait in F. radicans. This thesis presents further insight in F. radicans role within the Baltic Sea ecosystem and its value as a study species for adaptation, clonality and speciation. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript.</p>

I investigated the relative effects of grassland cover and fragmentation per se, and the relative influence of landscape and local habitat characteristics on grasslands songbirds in the moist mixed-grass prairies of Manitoba. In 2013, 361 avian point counts were conducted across 47, 2.4-km radii landscapes in the southwest part of the province. I used an information-theoretic approach to rank and select models describing effects of landscape and local-scale habitat variables on grassland songbird abundance and occurrence. Overall, my results indicate that grassland amount, fragmentation and quality, and matrix composition had relatively small and variable effects on grassland songbird abundance and occurrence, but that abundance of obligate species when pooled showed a strong negative response to grassland fragmentation. While fragmentation through edge effects may contribute to obligate species declines, my results suggest that these factors alone are unlikely to explain ongoing declines of grassland birds in southwestern Manitoba. / October 2016

This dissertation describes research into the synthesis of carbon nanotubes using traditional organic synthetic methods, as well as work on the fragmentation of β-hydroxy-α-diazoesters with a γ-hetero group and applications of their reactivity towards natural product synthesis. Carbon nanotubes are unique structures that can exhibit different electronic properties based on their chiral vector, and are a potential future source of semiconductors. Current methods of synthesis are unable to be adapted to commercial synthesis, providing the opportunity for the application of organic synthetic methods to generate them more uniformly and on a larger scale. The generation of tethered aldehyde ynoates and their utilization in 1,3-dipolar cycloadditions has been well developed by the Brewer group. Traditionally they have been generated from γ-siloxy-β-hydroxy-α-diazoesters, herein we explore utilizing an amino group as the fragmentation initializer. Additionally, application of the tethered aldehyde ynoate towards the synthesis of the natural products Demissidine and Aspidospermine are discussed.

Ce mémoire de thèse concerne l’analyse mathématique et numérique du comportement asymptotique de certains modèles de type coagulation-fragmentation intervenant en physique ou en biologie.Dans la première partie, on considère le système d’équations de Lifshitz-Slyozov qui modélise l’immersion d’une population de macro-particules en interaction avec un bain de monomères. Ce modèle développe en temps long un comportement dépendant d’une manière très particulière de l’état initial et ses spécificités techniques en font un véritable challenge pour la simulation numérique.On introduit un nouveau schéma numérique de type volumes finis basé sur une stratégie anti-dissipative ; ce schéma parvient à capturer les profils asymptotiques attendus par la théorie et dépasse en performances les méthodes utilisées jusqu’alors. L’investigation numérique est poursuivie en prenant en compte dans le modèle des phénomènes de coalescence entremacro-particules à travers l’opérateur de Smoluchowski. La question est de déterminer par l’expérimentation numérique comment ces phénomènes influencent le comportement asymptotique. On envisage aussi une extension du modèle classique de Lifshitz-Slyozov qui prend en compte des effets spatiaux via la diffusion des monomères. On établit l’existence et l’unicité des solutions du système couplé hyperbolique-parabolique correspondant. La seconde partie de ce mémoire aborde des modèles d’agrégation fragmentation issus de la biologie. On s’intéresse en effet à des équations décrivant les phénomènes de croissance et de division pour une population de cellules caractérisée par sa densité de répartition en taille. Le comportement asymptotique de cette densité de répartition est accessible à l’expérience et peut être établi théoriquement. L’enjeu biologique consiste, à partir de données mesurées de la densité cellulaire, à estimer le taux de division cellulaire qui, lui, n’est pas expérimentalement mesurable. Ainsi, retrouver ce taux de division cellulaire fait appel à l’étude d’un problème inverse que nous abordons théoriquement et numériquement par des techniques de régularisations par quasi-reversibilité et par filtrage.La troisième partie de ce travail de thèse est consacrée à des systèmes couplés décrivant des interactions fluide-particules, avec des termes de coagulation–fragmentation, de type Becker–Döring. On étudie les propriétés de stabilité du modèle et on présente des résultats d’asymptotiques correspondant à des régimes de forte friction. / This thesis concerns the mathematical and numerical analysis of the asymptotic behavior of some coagulation-fragmentation type models arising in physics or in biology.In the first part we consider the Lifshitz-Slyozov system that models the dumping of a population of macro-particles in interaction with a bath of monomers. This model develops in long time a behavior depending in a very particular way on the initial data abd its technical specificities make a real challenge for the numerical simulation. We introduce a new numerical finite volume type scheme based on an anti-dissipative strategy; this scheme succeeds in capturing the asymptotic profiles waited by the theory and exceeds in performances the methods used before. The numerical investigation ispursued by taking into account in the model the phenomena of coalescence between macro-particles through the Smoluchowski operator. The question is to find by numerical experiment how these phenomena influence the asymptotic behavior. We also consider an extension of the classical Lifshitz-Slyozov model which takes into account the spatial effects via the diffusion of monomers. We establish the existence and the uniqueness of the solutions of the corresponding hyperbolic-parabolic coupled system.The second part of this thesis deals with approaches coagulation-fragmentation models stemming from biology. Indeed, we are interest in equations describing the phenomena of growth and division for a celles population caracterised by its size density repartition. The asymptotic behavior of this size density repartition is accessible to the experiment and can be established in theory. The biological stake consists, from measured data of the cellular density, to estimate the cellular division rate which is not experimentally measurable. So, to find this cellular division rate requires the study of an inverse problem which we approach numerically and theoretically by techniques of regularizations by quasi-reversibility and by filtering.This third part of this thesis work is devoted to coupled systems describing fluid-particles interactions with coagulation-fragmentation terms of Becker-Döring type. We study the stability properties of the model and we present some asymptotic results corresponding to the regime with strong friction force.

The Grassland biome of South Africa has been identified as critically endangered and the biome in South Africa most requiring conservation attention through the implementation of efficient, sustainable systematic conservation plans. The ability to predict where land-cover transformation as well as information on the occurrence and severity of current land cover transformation activities, as threats to biodiversity, is required as part of the systematic conservation planning process. Neke & du Plessis (2004) predicted land cover transformation and the severity of the impact on biodiversity in the Grassland biome. This model was based on potential land use suitability models and land cover information for the 1994/5 season extracted from the National Land Cover database (NLC1994). These predictions were tested by assessing actual land cover change in the Grassland biome using observed differences in grassland land cover between the NLC1994 and NLC2000 databases. Methodology Because of differences in format and land-cover classification between the original datasets, both NLC1994 and NLC2000 had to be modified before any analyses could be carried out. These differences exist because different techniques were used to collate the respective datasets, thus introducing the potential for significant mapping error in the original datasets and more significantly erroneous results with respect to landcover change detection. The implications of this were presented in the discussion. Both datasets were spatially resampled and class-standardised and it was felt that this would significantly reduce any the impact of any such existing errords in the original datasets. Thereafter landcover information for the Grassland biome was be extracted and the comparative landcover analyses executed. The analyses carried out included: • Landcover change per landcover class within the Grassland biome with emphasis on the Grassland landclass losses and gains • An assessment and comparison of the relative fragmentation of the remaining grassland patches in both datasets • An assessment of current grassland habitat degradation • The comparison of the predicted land cover change as given by Neke & du Plessis (2004) against the observed grassland changes • The creation of a new Grassland Transformation threat map reflecting current land cover change threats, and including information pertaining to the threats to Grassland biodiversity posed by invasive alien plants, road effects, urban areas and soil erosion hazards. Results and Discussion 25% of the remaining grassland patches underwent transformation to other land classes. Grassland clearing for cultivation, bush encroachment and bushland vegetation regeneration were the main causal factors behind the observed grassland losses. However, grassland vegetation regeneration on formerly cultivated land, bush clearing and reclassification of degraded lands as grasslands in the NLC2000 dataset contributed to a net 2% gain in area of the grassland land class. The remaining grassland patches are more fragmented than they were in NLC1994, the average patch size (NLC2000) is three times smaller and the total number of grassland patches has increased (also by a factor of 3) and the remaining grassland patches are more isolated. The largest, least fragmented grassland patches occur along and to the west of the Great Escarpment as it traverses the Grassland biome. Most of the predictions of grassland transformation were realised, however the model used by Neke & du Plessis (2004) consistently underestimated and in some cases failed to predict the occurrence of grassland transformation in the central interior of the Grassland biome. Current, measurable human activities that act as grassland transformation agents were incorporated to create a threat map showing the extent and severity of land-cover transformation activities within the biome; grassland bird species richness information was then incorporated into this map to create biodiversity transformation threat map. This map was used to show the location and severity of the impacts of human transformation activities on grassland biodiversity. Both transformation threat map reflect the current situation across the biome today and were compared against the Potential transformation threat map produced by Neke & du Plessis (2004). The human transformation threat map confirmed the inability of the Neke & du Plessis model to make correct predictions of land cover change away from the eastern, 7 high altitude boundary of the biome. Given that the biome is defined by its climatic characteristics, the incorporation of global climate change effects would further refine the results gained, and perhaps provide more accurate predictions. As aforementioned, there are however factors existing within the original datasets used in this analysis that may have affected the accuracy of the landcover change analyses. These factors are centred on the potential effects of mapping errors within either of the NLC datasets. The delineation of landclass boundaries in the NLC1994 dataset is one such factor- placing a line over what is in reality a gradient of changing vegetation, is a subjective exercise and depends entirely on the technician involved this in itself may have introduced a fair amount of error in the mapping process. When coupled with the automated classification techniques used, for the most part, for the NLC2000 dataset, it becomes apparent that it is highly unlikely that even in the absence of actual landcover change the same boundaries would be drawn between two landclasses in the same area. This would provide false positive results for landcover change where in fact this is as a result of mapping errors. This is acknowledged and included in the interpretation of the results and it is felt that in spite of this, all possible steps were taken to minimize the impact of these effects on the reslults. The analysis allowed the identification of the current land cover transformations leading to grassland loss. However, land-cover change is only the physical expression of the complex interactions between socio-economic factors. To create effective and sustainable conservation plan for the Grassland biome, with an aim to reducing habitat loss requires an action plan to address these factors as the ultimate drivers of land cover change.

This study examines solidarity and fragmentations between trade unions and civil society organisations under the Labour and Civil Society Coalition LASCO, during the fuel subsidy mass-protest in Nigeria. To understand the basis of LASCO’s mobilisation during the strike/ mass-protest and the tension that follows the suspension of the strike within the alliance, the study utilises the literature on Social Movement Unionism especially in South Africa, with emphasise on trade unions community and political alliances. The classical SMU literature especially applied in South Africa and Brazil revealed that authoritarian industrialisation and repressive Apartheid work-place regime prompted unions to use innovative strategies of using their bargaining power to challenge the state, by rendering themselves ungovernable both in the work-place and in the society through linkages with communities. This study, relying on a case study method and participant observation of the strike and mass-protest in Kano, revealed that SMU mobilisation in Nigeria was triggered by predatory and weak state, whose rent seeking permeates the administration of subsidy in the oil industry. Secondly, the study argued that the tensions and divisions within LASCO alliance following the suspension of the perceived unilateral suspension of the strike by the Trade Unions explains the political and class orientation of both trade unions and civil society organisations. The study argues that Trade Unions behaviour in the context of the strike lean towards Hyman pessimist view of trade unions or what Beiler et’al called accommodatory strategy, a view that see unions as negotiators of order both in the work-place and in the larger society. On the other hand the civil society organisations typified multi-level organisations with different orientations that always seek for transformation of the social order or what Beiler et’al called transformatory strategy.

O mercado de capitais, e especialmente o mercado secundário, está entre os setores da economia que reagem mais prontamente às inovações tecnológicas. Nos últimos anos, o desenvolvimento tecnológico e das telecomunicações alterou dramaticamente a configuração do mercado secundário: os pregões viva-voz desapareceram, dando lugar aos sistemas eletrônicos de negociação que executam negócios a velocidades imperceptíveis ao ser humano. Concomitantemente, alterações regulatórias visando ao aumento da concorrência nos mercados secundários proporcionaram a criação de ambientes de negociação com e sem transparência, gerando a fragmentação da liquidez. No Brasil, embora o mercado seja altamente eletronificado e o processo de alteração regulatória também tenha ocorrido, não se verificou o aumento da concorrência no mercado secundário de ações. A partir de uma análise comparativa com mercados fragmentados, este trabalho propõe algumas reformas na regulação brasileira com vistas a melhoraria da qualidade do mercado por meio da introdução de concorrência. / Capital markets, and especially the secondary market, are among the sectors that react more quickly to technological innovations. In recent years, technological and telecommunication developments dramatically changed the structure of the secondary market: the open outcry sessions disappeared, giving way to electronic trading systems with execution speeds imperceptible to humans. At the same time, regulatory changes aimed at increasing competition in the secondary markets led to the creation of lit and dark trading venues, generating the fragmentation of liquidity. In Brazil, although the market is highly electronic and the regulatory change process has also occurred, there was no increased competition in the secondary stock market. From a comparative analysis with fragmented markets, this paper proposes some reforms in the Brazilian regulation in order to improve the quality of the market through the introduction of competition.

Thesis advisor: Marc L. Snapper / Intramolecular [2+2] photocycloadditions have been studied: (i) Previous studies in our group have demonstrated that there is a regiochemical dependence of intramolecular [2+2] photocycloadditions on the solvent employed. In order to understand the generality of hydrogen bonding effects of photochemical reactions of β-hydroxyl enones, we examined the photochemical outcome of enones with both acyclic and cyclic olefin tethers. (ii) An application of an intramolecular [2+2] photocycloaddition/ fragmentation strategy to form 5-8-5 ring systems has been demonstrated toward the synthesis of the natural product cycloaraneosene. / Thesis (PhD) — Boston College, 2008. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

This thesis is a collection of three essays, each of which analyses an economic institution in one or more developing countries. A careful analysis of institutions is crucial for the understanding of economic performance and for the design of effective policy measures. In the first essay, "On the Structure of Tenancy Contracts" I analyse the effect of crop and tenant characteristics on the form and on the length of tenancy contracts. Using a principal-agent model I show that highpowered incentives are used when, due to the characteristics of the crop, their benefit is high and/or when, due to the characteristics of the tenant, their cost is low. The theoretical predictions are consistent with the empirical evidence from a unique data set of 705 contracts. The purpose of the second essay, "Competing for Protection: Land Fragmentation and the Rise of Mafia in 19th Century Sicily", is to identify the conditions that fostered the development of the mafia. I argue that in the context of 19th century Sicily, land fragmentation was crucial for the rise of mafia. Using a menu-auction model I show that, by inducing landlords' competition for protection, land fragmentation increases the profits of mafia groups even if the assets in need of protection are unchanged. I show that the predictions of the theory are consistent with the available empirical evidence from a sample of 70 Sicilian villages. In the third essay, "Does Financial Reform Raise or Reduce Savings?", we analyse the effect of financial liberalisation on private savings in eight developing countries. To this purpose we construct an index which summarises the reform process and estimate an error correction model for savings. We find that the effect of financial reform on savings is ambiguous. / Thesis (PhD) — Boston College, 1999. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

Fatores biogeográficos, em particular a posição da população em relação à sua área de distribuição geográfica, podem mediar variações interpopulacionais da resposta das espécies à fragmentação do habitat. O presente estudo teve como objetivo verificar se a posição biogeográfica das populações pode predizer a sensibilidade das espécies de aves à distribuição espacial do seu habitat, medida pela cobertura e configuração dos remanescentes florestais em paisagens fragmentadas. Considerando 21 espécies presentes em pelo menos 30 fragmentos, estabelecemos modelos de regressão relacionando a abundância destas espécies com a cobertura e configuração dos remanescentes, e ainda com a posição biogeográfica das populações. A variável de posição biogeográfica foi obtida através de modelos de distribuição das espécies, utilizando o algoritmo de máxima entropia (Maxent). Utilizamos o Critério de Informação de Akaike (AIC) para comparar os modelos e verificar a importância relativa de cada variável. Grande parte das espécies (n = 10) apresentou um padrão de resposta semelhante, que é o de serem influenciadas tanto por variáveis de configuração da paisagem, quanto pela posição biogeográfica em que se encontram as populações. Outras seis espécies foram influenciadas somente por características da paisagem, enquanto duas foram influenciadas somente pela posição biogeográfica das populações. Houve ainda três espécies que não mostraram sofrer influência de nenhuma das variáveis utilizadas. Não foram verificadas características biológicas das espécies que estivessem relacionadas com esses grupos de respostas das espécies. De maneira geral, o presente estudo mostrou que a posição biogeográfica das populações, assim como os parâmetros de estrutura da paisagem, são fatores importantes na determinação da abundância das populações da maioria das espécies de aves em paisagens fragmentadas. Tais resultados têm implicações para o próprio entendimento da persistência de populações de aves em paisagens fragmentadas, assim como para o direcionamento de esforços voltados para planos de conservação em escalas regionais. / Species distribution models (SDM) is a quite new technique that has been used in many fields of natural sciences. Nevertheless, as problem inherent of a new technique, there is still a lot of questions about the most appropriated manner of its use and application. As the SDM consists a powerful tool with high potential to be used use in many fields of research, it is extremely useful that tests are carried out, to improve and refine this technique. To help in the development of the SDM, this study consist a methodological test that aims to compare the performance of different algorithms used in SDM. We used points of occurrence of 21 bird species along an area of nearly 1,200,000 km2 in southeastern Brazil. The data were obtained through a rough bibliographic revision. Environmental layers used in the modeling procedure consisted of 19 bioclimatic variables, besides altitude and slope of the terrain. The algorithms used were Maxent, GARP and SVM. As a performance parameter of the algorithms we used the area under de ROC curve (AUC), generated with points of occurrence independent of the ones used for the modeling procedure. Based on the AUC values, we observed a higher prevision capacity of the models generated with Maxent, followed by the ones generated with SVM, and at least, the ones generated with GARP. The pattern of the probability distributions of the models generated with Maxent and SVM had a higher biological meaning, besides agreeing more with the species real area of occurrence. As conclusion of this study we consider that Maxent is the most appropriate algorithm to be used in species distribution models, that are made under the same conditions of the ones used in the present study. Biogeographical factors, specially the location of populations in relation to the occurrence area of the species, could mediate interpopulational variations in species response to habitat fragmentation. The present study aimed to verify if the biogeographical position of populations can predict bird species sensitivity to habitat spatial distribution, measured as the forest cover and configuration in fragmented landscapes. Considering 21 species present in at least 30 fragments, we established regression models relating the abundance of the species with patch cover and configuration of the patches, and with the population biogeographical position. This position was obtained through species distribution models, with the maximum entropy algorithm (Maxent). We used the Akaike Information Criteria (AIC) to compare the models and verify the relative importance of each variable. Most of the species (n= 10) presented a similar response pattern, being influenced by landscape configuration and also by biogeographical position parameter. Six other species were influenced only by landscape structure, while two species were influenced only by biogeographical position. There were also three other species that were not influenced by any of the used variables. The response pattern to the independent variables seems to be independent of the biological characteristic of the species. The present study showed that the biogeographical position of the populations could be, with the landscape structure, an important factor to determine the abundance of major part of bird species in a fragmented landscape. Such results have implications on the comprehension of bird species persistence in fragmented landscapes, as well to driven effort for conservation plans in regional scales.