The doctoral research revolves around a comparative study of timber modern methods of construction for low-rise, residential buildings in Scotland. The building techniques studied involve both timber-frame panel construction (open-panel and closed-panel systems and structural insulated panels) and massive-timber construction (cross-laminated and nail-laminated timber panels). A non-timber technique is also included in the study: more traditional, load-bearing masonry (blockwork). These different building techniques have been analysed from two complementary aspects: environmental impacts and thermal performance. The environmental study is based on the life-cycle assessment methodology and embraces various aspects: environmental impacts (e.g., climate change, acidification, eutrophication, ozone depletion, etc.), consumption of energy (renewable and non-renewable resources) and production of waste (from non-hazardous to radioactive). The assessment takes a cradle-to-gate approach and, in its structure and method, is informed by the current recommendations of the international standards in the field (i.e., ISO 14040 series). Various environmental trade-offs between construction methods have been identified. In terms of global-warming potential (excluding biogenic carbon sequestration), results suggest that timber-frame buildings show a better performance than masonry buildings; this is particularly true for the open-panel system, which emits about 10% less carbon than the masonry counterpart. Massive-timber buildings tend to cause more carbon emissions than masonry ones. In terms of consumption of non-renewable primary energy, timber buildings do not generally show significant advantages with respect to blockwork-based masonry. In particular, structural-insulated panel systems tend to show very high energy requirements. Timber-based buildings show a tendency to cause increased acidification, eutrophication and creation of low ozone than their masonry counterpart. The level of offsite fabrication that is employed for the erection of the buildings plays an important role in the magnitude of most environmental impacts, which show an average decrease between 5% and 10% when some of the operations are shifted from the construction site to the factory. v The thermal study investigates the performance of the building envelope, and, in particular, of external walls, by means of tests whereby the thermal behaviour of a sample of walls (of full-size section) has been observed and measured over time. On the outside, the walls were exposed to real, natural weather variations throughout the summer. The study especially focuses on the time-dependent response of three different walling systems (which results from their individual cross-sectional arrangements of building components and the associated combination of heat-storage capacity and thermal resistance): a timber-framed wall, a cross-laminated-timber wall and a masonry wall. Thus, the main goal of the study was to characterise the thermal-inertia parameters of these walls. This type of thermal behaviour is related to the repercussions of global climate change at UK level, especially in terms of increase in solar irradiance and temperature, which requires an adaptation of the building-envelope such that it can perform well both during wintertime and summertime, by providing maximum indoor comfort with minimum economic and environmental costs from the construction and operation of buildings. The timber-framed wall possesses the greatest capacity to slow down the propagation of temperature waves from the outer surface to the inner surface (time lag), whereas the masonry wall performs best with respect to reducing the amplitude of temperature oscillation on the inner surface (decrement factor). The cross-laminated-timber wall exhibits intermediate values of both time lag and decrement factor, relative to the other two walls. Both the thermal and life-cycle assessment of the construction alternatives aim at assisting the design and decision-making process in the residential field and at suggesting areas that need to be addressed and improved, towards a coherent evolution of the building techniques included in this study and a step forward in the realisation of sustainable, low-rise dwellings.

<p>The work in this thesis deals with the ecology and evolution of adaptive individual variation. Ecologists have long used niche theory to describe the ecology of a species as a whole, treating conspecific individuals as ecological equivalent. During recent years, research about individual variation in diet and morphology has gained interest in adaptive radiations and ecological speciation. Such variation among individual niche use may have important conservation implications as well as ecological and evolutionary implications. However, up to date we know very little about the extension of this phenomenon in natural populations and the mechanisms behind it.</p><p>The results in this thesis show that the extension of individual diet specialization is widely spread throughout the animal kingdom. The variation in diet is mainly correlated to morphological variation but not always. Furthermore, this variation in diet and morphology among individuals could be both genetically determined and environmentally induced and it mainly comes from trade-offs in foraging efficiency between different prey types. </p><p>The results from a number of studies of perch also show that individual perch differ in morphology and diet depending on habitat, where littoral perch has a deeper body compared to pelagic perch. This difference in morphology corresponds to functional expectations and is related to foraging efficiency trade-offs between foraging in the littoral and pelagic zone of a lake. The variation in morphology in perch is mainly due to phenotypic plasticity but there are also small genetic differences between the littoral and pelagic perch. Two separate studies show that both predation and competition may be important mechanism for the variation in morphology and diet in perch.</p><p>In conclusion, the results in this thesis show that individual variation in diet and habitat choice is a common phenomenon with lots of ecological and evolutionary implications. However, there are many mechanisms involved in this phenomenon on which we are just about to start learning more about, and only further research in this area will give us the full insight.</p>

Age is often a neglected factor in ecological studies. However, age-related changes in reproduction and survival of organisms may strongly influence population dynamics. The Gotlandic population of collared flycatchers is a perfect system for studying age-related changes in the wild, as the exact age and reproductive history of most individuals is known. Collared flycatchers (Ficedula albicollis) on Gotland show the typical pattern of age-related changes in survival and reproductive success; both factors show an increase early in life and a decrease late in life. This thesis presents a broad study not only of age-related patterns of reproduction and immunity, but also proposes the mechanisms driving these patterns. My results show that in addition to survival probability and reproductive performance, reproductive costs and life-history trade-offs also change with progressing age. There is a significant increase in reproductive performance at the population level during first years of life which result from selection against low quality phenotypes. On the individual level this pattern is best explained by an optimization of reproductive effort. However, high quality individuals have higher reproductive success as early as their first breeding event and are long-lived. Thus, they seem to adopt a different strategy than lower quality, short-lived individuals. Differences in individual quality seem to be shaped by the developmental conditions experienced as nestlings. Fledglings with longer tarsi, but lower body mass become long-lived, high quality adults. Young individuals breeding for first time pay higher costs of reproduction. They also express a limited ability to reduce these costs by breeding in high quality territories when compared to middle-aged individuals. Young individuals seem to invest more into self-maintenance, whereas old individuals reduce the level of self-maintenance (measured as immune response) and redistribute their investment towards reproduction. Thus, old individuals are limited in their ability to reduce reproductive costs under favorable conditions, especially as they also senesce, which pattern is also shaped by individual quality. Variation in individual quality appears to have an strong effect on age-related survival probability, reproductive performance, reproductive costs, and even life-history decisions. Therefore, taking this factor into account in studies of life-history patterns is necessary to obtain reliable results.

This project predominantly investigated the implications of spatial heterogeneity in the ecological processes of competition and infection. Empirical analysis of spatial heterogeneity was carried out using the lepidopteran species Plodia interpunctella. Using differently viscous food media, it was possible to alter the movement rate of larvae. Soft Foods allow the movement rate of larvae to be high, so that individuals can disperse through the environment and avoid physical encounters with conspecifics. Harder foods lower the movement rate of larvae, restricting the ability of individuals to disperse away from birth sites and avoid conspecifics encounters. Increasing food viscosity and lowering movement rate therefore has the effect of making uniform distributed larval populations more aggregated and patchy. Different spatial structures changed the nature of intraspecific competition, with patchy populations characterised by individuals experiencing lower growth rates and greater mortality because of the reduced food and space available within densely packed aggregations. At the population scale, the increased competition for food individuals experience in aggregations emerges as longer generational cycles and reduced population densities. Aggregating individuals also altered the outcome of interspecific competition between Plodia and Ephestia cautella. In food media that allowed high movement rates, Plodia had a greater survival rate than Ephestia because the larger movement rate of Plodia allowed it to more effectively avoid intraspecific competition. Also the faster growth rate, and so larger size, of Plodia allowed it to dominate interspecific encounters by either predating or interfering with the feeding of Ephestia. In food that restricts movement, the resulting aggregations cause Plodia to experience more intraspecific encounters relative to interspecific, reducing its competitive advantage and levelling the survival of the two species. Spatial structure also affected the dynamics of a Plodia-granulosis virus interaction and the evolution of virus infectivity. Larval aggregation forced transmission to become limited to within host patches, making the overall prevalence of the virus low. However potentially high rates of cannibalism and multiple infections within overcrowded host aggregations caused virus-induced mortality to be high, as indicated by the low host population density when virus is presented. Also aggregated host populations cause the evolution of lower virus infectivity, where less infective virus strains maintain more susceptible hosts within the aggregation and so possess a greater transmission rate. The pattern of variation in resistance of Plodia interpunctella towards its granulosis virus was found using two forms of graphical analysis. There was a bimodal pattern of variation, with most individuals exhibiting either low or high levels of resistance. This pattern was related to a resistance mechanism that is decreasingly costly to host fitness.

Introduction: En réponse aux exigences du gouvernement fédéral en ce qui concerne les temps d'attente pour les chirurgies électives d’hanche et du genou, les Organismes Canadiens de santé ont adopté des stratégies de gestion pour les listes d'attente. Cependant, il n'existe pas actuellement aucune information disponible concernant les effets imprévus, positive ou négative, de ces stratégies. Méthodologie: Un modèle qui a été construit est tombé en panne la gestion de la chirurgie d’hanche et du genou en différentes étapes, afin d'identifier les effets imprévus possibles pour chaque étape; le modèle a été validé auprès d'un panel d'experts. Cette étude a choisi quatre études de cas en fonction de leur durabilité: un cas qui a été durable, un cas qui a été modérément durable, et deux cas peu probable d'être durable. Dans cette étude qualitative, nous avons mené 31 entretiens semi-structurés entre Novembre 2010 et Juin 2011 avec les gestionnaires, les infirmières, les thérapeutes et les chirurgiens impliqués dans la gestion des stratégies du temps d’attente pour les chirurgies électives d’hanche et du genou. Les quatre cas ont été sélectionnés à partir de trois provinces / régions. Nous avons analysé les conséquences non intentionnelles aux niveaux systémique et organisationnelle en utilisant les stratégies dans chaque contexte. Enregistrements des entrevues ont été transcrits mot à mot et soumis à l'analyse du cadre. Résultats: Les effets négatifs sont la précarité des stratégies en raison du non-récurrente financement, l'anxiété chez les patients qui ne sont pas prêts pour la chirurgie, une redistribution du temps de chirurgie vers l’orthopédie au détriment des autres interventions chirurgicales, tensions entre les chirurgiens et entre les orthopédistes et anesthésistes, et la pression sur le personnel dans le bloc opératoire et postopératoire. Conclusion: La stratégie d’implémentation aux niveaux national et local devrait prendre en compte les conséquences potentielles, positives et négatives. Il y a des conséquences inattendues à chaque niveau de l'organisation des soins de santé. Individuellement et collectivement, ces conséquences peuvent positivement et négativement affecter les résultats. Par conséquent, la planification de la santé doit analyser et prendre en compte les conséquences inattendues en termes de bonnes résultats inattendues, compromis et les conséquences négatives afin d'améliorer les résultats. / Introduction: In response to federal government requirements regarding wait times for elective hip and knee surgeries, Canadian healthcare organizations have adopted wait list management strategies. However, there is currently no information available regarding the unanticipated effects, positive or negative, of these strategies. Methodology: A model was constructed that broke down the management of elective hip and knee surgery into different steps, in order to identify the unanticipated potential effects for each step; the model was validated with a panel of experts. This study chose four case studies based on their sustainability: one case that was sustainable, one case that was moderately sustainable, and two cases considered unlikely to be sustainable. In this qualitative study, we conducted 31 semi-structured interviews between November 2010 and June 2011 with managers, nurses, therapists and surgeons involved in wait time management strategies for hip and knee surgeries. The four cases were selected from three provinces/areas. We analyzed potential unintended consequences at the systemic and organizational levels of using these strategies in each setting. Interview recordings were transcribed verbatim and subjected to framework analysis. Results: Negative effects were the strategies’ precariousness due to non-recurrent funding, anxiety in patients not ready for surgery, a redistribution of surgical time toward orthopaedics at the expense of other surgeries, tensions between surgeons and between orthopaedic surgeons and anaesthesiologists, and significant pressure on personnel in the operating suite and in post-operative care. Conclusions: Strategy implementation at the national and local levels should take into consideration any potential consequences, positive and negative. There are unintended consequences at each level of healthcare organization. Individually and jointly, these consequences can positively and negatively affect outcomes. Therefore, health planning should analyze and take into account unintended consequences in terms of serendipities, trade-offs and negative consequences in order to improve results.

The effectiveness of land sharing and land sparing (LS/LS) approaches to conservation in the face of rising agricultural demands has been widely debated. While numerous studies have investigated the LS/LS framework from an ecological lens (yield-biodiversity relationship) the relevance of the framework to real life depends on broader considerations. Some of the key caveats include: i) limited knowledge regarding the feasibility of interventions given diverse stakeholders’ interests, ii) the social acceptability (uptake) of these contrasting strategies to direct land users, and iii) limited knowledge regarding their impacts on individuals’ livelihoods and food security. Without considering these social science dimensions proponents of the framework risk an incomplete picture that is not grounded in local realities and can paradoxically force into opposition the very conservation and development interests they seek to reconcile. Using a Companion Modelling approach, which comprises the development of a role-playing game (RPG) and an agent-based model (ABM), this thesis addressed these caveats. The research was based in the Nilgiris of Western Ghats India, a tropical agricultural system at the forest frontier. The main findings show that through engaging local stakeholders in a participatory process, plausible land use strategies that align with their objectives could be identified. Stakeholders proposed three land use interventions. Two of them resemble a form of land sparing (‘monofunctional’ landscapes) on the farms: sparing land for Wildflower Meadows or Tree Plantations while increasing yield on the remaining land. The third intervention asks farmers to accept yield penalties for Intercropping more trees on their farms, a form of land sharing (‘integrated’ landscapes). In terms of decision-making regarding the adoption of these three interventions by direct land users, the study reveals several findings. Firstly there are three main types of motivations that influence farmers’ decision to adopt interventions, in order of importance: monetary benefits, pro-environmental motivations and social norms. Secondly, land use, the type of management preferred on the farm and whether land users accept trees on the farm or not are factors that influence what type of interventions is socially acceptable on individual farms. These factors have been detected in the in-depth household survey and also validated by the RPG. When assessing the adoption of the three interventions, ex ante their implementation, using an ABM, there are some important differences observed between the interventions. Wildflower Meadows is the intervention adopted by the largest number of households, whereas Intercropping is adopted across the largest area of land. Forest Plantations is significantly more unpopular than the other two interventions. The third line of investigation, about the outcomes of adoption, has important policy implications. Adding a socioeconomic dimension to the ecological one adds a level of complexity and creates a less straightforward choice between the LS/LS strategies. None of the three interventions can provide optimal outcomes for production, aspects of biodiversity conservation, livelihoods and food security. Each intervention has indicators that score better compared to the other two interventions. The findings demonstrate that the ecological focus of the LS/LS framework is insufficient to deal with real-world complexities and lends itself to overly simplistic policy prescriptions. More meaningful policies could be achieved when bridging natural and social sciences to better understand the merits and limitations of the LS/LS approaches.

L’attention scientifique s’est récemment portée sur l’identification des mécanismes proximaux sous-tendant les compromis évolutifs;tels que les compromis existant entre croissance/reproduction et longévité. La production d’espèces réactives de l’oxygène (ROS )a été suggérée comme un candidat potentiel ,de par sa liaison étroite au métabolisme énergétique (sous-­produits du fonctionnement mitochondrial) et son caractère inévitable. Si la production de ROS excède le niveau des défenses antioxydantes, une situation de stress oxydant va en résulter et a été associé au vieillissement . Puisque la mitochondrie n’est pas uniquement la centrale énergétique de la cellule mais aussi le principal producteur de ROS, cette thèse s’est attachée à clarifier les relations entre métabolisme énergétique , fonctionnement mitochondrial et stress oxydant ; avec des études concernant l’impact d’activités coûteuses en énergie (croissance, reproduction, thermogénèse) sur l’équilibre de la balance oxydative. / In recent years, scientific attention has turned towards the identification of the mechanisms underlying the trade-­‐offs occurring between growth rate/reproductive investment and longevity. Amongst these mechanisms, the production of reactive oxygen species (ROS) appears to be a key factor due both to its universal and inevitable nature. ROS are by-­‐products of energy processing by the mitochondria. If ROS production exceeds the capacity of the various antioxidant systems, oxidative stress will occur, and the accumulation of oxidative damage over time is thought to be a potential cause of ageing. Since mitochondria are not only the powerhouse of animal cells but also the main producer of ROS, this PhD thesis aimed to clarify the relationships between mitochondrial uncoupling state (i.e. efficiency to produce ATP), energy metabolism and oxidative stress. I investigated the impact of energy-­‐demanding activities such as thermogenesis, reproduction and growth on oxidative homeostasis.

Le compromis d’allocation de l’énergie entre les fonctions concurrentielles de la reproduction et de la maintenance (et à long terme la survie) est largement tributaire de la capacité de l’organisme à acquérir des ressources dans son milieu. Les mécanismes physiologiques sousjacents aux décisions d’acquisition et d’allocation de l’énergie sont actuellement peu connus. Le but de cette thèse est d’étudier le rôle de deux hormones, la corticostérone et la prolactine, dans ces prises de décisions chez un oiseau marin longévif, le manchot Adélie (Pygoscelis adeliae), et ce, pendant une phase couteuse en énergie : la période d’élevage des poussins. Pour ce faire, nous avons conduit des approches expérimentales couplant d’une part la manipulation hormonale (augmentation des niveaux de corticostérone ou diminution des niveaux de prolactine) et la mesure du comportement en mer grâce à l’utilisation d’enregistreurs miniaturisés de l’effort de plongée. Par ailleurs, le budget temps, la condition corporelle, le régime alimentaire (analyses des isotopes stables du carbone et de l’azote) ainsi que le succès de reproduction des individus ont été considérés. A l’échelle de la plongée, nous avons observé des rôles positifs et négatifs de la corticostérone et de la prolactine, respectivement, sur le comportement de recherche alimentaire. De façon contradictoire, il semble que la corticostérone ait eu un effet négatif à plus large échelle (e.g. diminution de la durée des voyages alimentaires). La complexité de l’implication de ces deux hormones dans le compromis entre survie et reproduction est finalement discutée à la lumière de ces résultats. / The trade-off in the allocation of energy between the competitive functions of reproduction and maintenance (and survival in the long term basis) is largely dependent on the capacity of organisms to acquire resources in its environment. However, physiological mechanisms underlying decisions of energy acquisition and allocation are currently poorly known. Theaim of this PhD is to examine the role of two hormones, corticosterone and prolactin, in these decision processes in a long-lived seabird, the Adélie penguin (Pygoseclis adeliae) during an energetically costly period: the chick-rearing stage. To achieve this, we conducted experimental approaches coupling hormonal manipulation (increasing corticosterone levels ordecreasing prolactin levels) and the monitoring of at-sea behaviour by using miniaturised time-depth recorders. Moreover, time budget, body condition, diet (via stable isotopes analyses) and reproductive success of individuals were considered. At the dive scale, we observed positive and negative roles of corticosterone and prolactin on the foraging behaviour, respectively. However on the contrary, it seems that corticosterone had a negative effect at a larger scale (e.g. a decrease in at-sea trip duration). The complexity of the involvement of these hormones in the trade-off between survival and reproduction is discussed in the light of these results.

The research conducted in this dissertation studies the issues regarding the improvement of phase noise performance in a BiCMOS Silicon Germanium (SiGe) cross-coupled differential-pair voltage controlled oscillator (VCO) in a narrowband application as a result of a tail-current shaping technique. With this technique, low-frequency noise components are reduced by increasing the signal amplitude without consuming additional power, and its effect on overall phase noise performance is evaluated. The research investigates effects of the tail-current as a main contributor to phase noise, and also other effects that may influence the phase noise performance like inductor geometry and placement, transistor sizing, and the gain of the oscillator. The hypothesis is verified through design in a standard 0.35 μm BiCMOS process supplied by Austriamicrosystems (AMS). Several VCOs are fabricated on-chip to serve for a comparison and verify that the employment of tail-current shaping does improve phase noise performance. The results are then compared with mathematical models and simulated results, to confirm the hypothesis. Simulation results provided a 3.3 dBc/Hz improvement from -105.3 dBc/Hz to -108.6 dBc/Hz at a 1 MHz offset frequency from the 5 GHz carrier when employing tail-current shaping. The relatively small increase in VCO phase noise performance translates in higher modulation accuracy when used in a transceiver, therefore this increase can be regarded as significant. Parametric analysis provided an additional 1.8 dBc/Hz performance enhancement in phase noise that can be investigated in future works. The power consumption of the simulated VCO is around 6 mW and 4.1 mW for the measured prototype. The circuitry occupies 2.1 mm2 of die area. Copyright / Dissertation (MEng)--University of Pretoria, 2010. / Electrical, Electronic and Computer Engineering / unrestricted

Les comportements de dispersion, c'est-À-Dire les mouvements conduisant à des flux de gènes dans l'espace, jouent un rôle majeur dans de nombreux processus écologiques et évolutifs. Les Gastéropodes terrestres sont des hermaphrodites simultanés dont le mouvement est extrêmement coûteux, une combinaison de traits très intéressante pour étudier les liens entre dispersion et autres traits d'histoire de vie. Dans le cadre de cette thèse, nous avons étudié (i) les relations complexes entre dispersion, croissance, reproduction mâle et femelle chez le petit-Gris Cornu aspersum, un escargot anthropophile, (ii) comment la dispersion et le comportement exploratoire de cette espèce varient en fonction de la compétition ressentie et de l'hétérogénéité environnementale, (iii) comment la propension à disperser coévolue avec d'autres traits à l'échelle interspécifique. Cornu aspersum passe par une phase subadulte mâle de durée variable avant de devenir adulte et hermaphrodite. Le comportement de dispersion s'exprime principalement pendant cette phase subadulte, et sa diminution chez les adultes est liée à l'accroissement de l'investissement dans la fonction femelle. Cette espèce disperse de façon très densité-Dépendante : les individus quittent les sites à haute densité et s'installent dans ceux peu peuplés, une stratégie qui facilite la colonisation et la persistance en environnements instables. La propension à explorer augmente en environnements urbains fragmentés, malgré les coûts plus élevés du mouvement. Au niveau interspécifique, dispersion et généralisme sont liés, ce qui rend les espèces spécialistes doublement vulnérables, mais facilite le succès des généralistes en milieux hétérogènes. Cette combinaison de traits a probablement joué un rôle majeur dans la colonisation de nombreux milieux anthropisés par cette espèce à travers le monde. / Dispersal behaviours, i.e. movements leading to gene flow in space, play a key role in many ecological and evolutionary processes. Terrestrial gastropods are simultaneous hermaphrodites and have an extremely high cost of locomotion, a seldom studied combination of traits which makes them very valuable to investigate the links between dispersal and other life-History traits. During this project, we investigated (i) the complex relationships and trade-Offs between dispersal behaviour, growth, male and female reproduction in the anthropophilous brown garden snail Cornu aspersum, (ii) how its dispersal and exploration vary as a function of competition and environmental heterogeneity, (iii) how dispersal ability coevolved with other traits at the interspecific level. This snail presents a male-Biased subadult phase of varying duration before reaching adulthood and hermaphroditism. Dispersal behavior was mostly expressed during this subadult stage, and its decrease in adults was linked to investment in the female function. Brown garden snail dispersal is highly density-Dependant: snails leave crowded sites and settle readily in low-Density patches, a strategy that facilitates colonization and persistence in spatio-Temporally variable environments. Their movement propensity increases in urban, fragmented habitats, despite the higher costs of movement. At the interspecific level, dispersal and ecological generalism are linked in a dispersal syndrome, which makes specialist species doubly vulnerable, but increases success odds of generalists in heterogeneous landscapes . This combination of traits is likely to have played a major role in the successful worldwide colonization of many anthropogenic landscapes by this species.