I studied nest characteristics, breeding dispersal, and nest defence behaviour of Northern Flickers (<i>Colaptes auratus</i>, hereafter flickers) in central interior British Columbia with respect to nest predation. My research focused on three questions: (1) Are there nest characteristics associated with the risk of nest predation and nest loss to European Starlings (<i>Sturnus vulgaris</i>)? (2) Does nest predation influence breeding dispersal? (3) Do parental attributes influence nest defence behaviour? <p> An examination of flicker nest-site characteristics at five spatial scales revealed that nests were safer from mammalian predators (N=81) when they were higher, concealed by vegetation, farther from continuous coniferous forest blocks, and contained fewer conifers within the nesting clump. Proximity to conifers increased predation risk, but nests safe from competitors (N=18) were closer to coniferous forest blocks and contained a higher percentage of conifers in the nesting clump. Flickers face a trade-off between being safe from predators and safe from competitors. <p> Nesting success did not influence between-year breeding dispersal by 159 male or 76 female flickers. Because nests and forest clumps were not predictably safe from predators, benefits of dispersing likely outweigh costs. Other factors such as mate-switching, nest ectoparasites, and a fluctuating food source may play larger roles in dispersal than nest predation. Within years, 73% of pairs switched nest sites after their first attempt failed due to predation (N=37); however, there was no reproductive advantage for these pairs compared to pairs that remained at their original nest. Stressful encounters with predators involving nest defence may trigger dispersal, although it seems to offer no greater nest success. Of 24 flicker pairs presented with a control model before egg-laying, 3 pairs abandoned their nest, whereas 4 out of 24 pairs presented with a squirrel model abandoned their nest. This suggests that a one-time encounter with a nest predator is not a sufficient deterrent against continued nesting. Rather, costs of finding and excavating or renovating a new cavity may cause individuals to tolerate some risk in nesting at a location with an active predator. <p> In experimental trials (N=94), intensity of nest defence behaviour against a model predator was not related to the sex, age, body size, and body condition of the defending adult(s). The sexes may have behaved similarly because they are similar in size and have similar survival patterns. Costs and benefits of nest defence for flickers of different ages may also be equal because flickers are relatively short-lived and their survival rate is not linked with age. Brood size of the defending adult was also unrelated to the intensity of nest defence. If flickers have adjusted their clutch size in relation to the number of young for which they can optimally provide care, then no effects of brood size on nest defence behaviour should be recorded, as was the case here.</p>

Abstract In order to explore the mechanisms causing trade-offs between sexual and asexual reproductions, the sea anemones Aiptasia pulchella were taken as objects since they can reproduce by both modes simultaneously. Specimens were reared under different temperatures, photoperiods, and densities. Total weights of lacerates were used as an index of investment in asexual reproduction, whereas gonad weights as an index of investment in sexual reproduction. Sea anemones reared under low temperature (22¢J) reached larger pedal disks and produced larger, heavier lacerates, they also produced heavier gonads than those under high temperature (29¢J). Those reared under long light hours (15¡G9) reached smaller sizes and produced heavier gonads than those under short light hours (9¡G15). But the effect of photoperiod on lacerate size, number and weight are not significant. Interaction effect was not significant between these two factors. Correlation between sexual and asexual investments was not significant, either. In addition, A. pulchella reared under low density (1 sea anemone/beaker) produced more, heavier lacerates and heavier gonads than those under crowding conditions (4 sea anemones/beaker). There was a significantly positive correlationship between sexual and asexual reproduction investments. It seems there was no trade-offs between sexual and asexual investiments of the sea anemone A. pulchella.

Le changement global, à travers l'impact des activités humaines sur les processus qui régulent le fonctionnement du système terrestre, pose des défis pour la société. L'accélération de multiples types de pressions humaines a eu des répercussions sur les systèmes socio-écologiques méditerranéens, notamment la réduction des contributions de la nature au bien-être humain, appelées services écosystémiques (SE). Un enjeu d’avenir est de comprendre comment les pressions sur les systèmes socio-écologiques (l'urbanisation, les pratiques de gestion des terres et les politiques de conservation de la nature) affectent l’approvisionnement des SE dans le bassin méditerranéen. L'objectif principal de cette thèse est d'analyser comment les flux de SE du bassin méditerranéen et les compromis entre eux sont affectés par les facteurs de changement. Une évaluation multidisciplinaire, couvrant de multiples échelles spatiales allant du bassin local au bassin méditerranéen a été utilisée pour analyser les changements dans l’offre et la demande de SE. Les impacts de l'urbanisation et des systèmes de gestion agricole couramment appliqués ce sont révélés négatifs sur l'offre de SE, ce qui pourrait entraver les progrès dans le cadre des objectifs de développement durable (ODD). Une meilleure gestion des systèmes d’utilisation des terres le long du gradient rural-urbain et l’engagement des acteurs pourraient donc contribuer à assurer les progrès des ODD. Les méthodes et les données choisies affectent les tendances des SE, les synergies et les compromis identifiés. Je conclus sur la nécessité d'appliquer une évaluation intégrée des SE pour fournir une estimation des tendances / Global change, through the impact of human activities on the processes that regulate the functioning of the earth system, poses important challenges to society. The acceleration of human pressures during the last decades has had profound impacts on mediterranean socio-ecological systems including the reduction of important contributions from nature to human well-being, referred to as ecosystem services (ES). There is growing concern about how pressures of social-ecological systems, in particular urbanization, land management practices and nature conservation policies, will affect the supply of ES in the mediterranean basin.The main goal of this thesis is to analyze how ES flows in the mediterranean basin area, and the trade-offs between them, are affected by drivers of change. To this end, a multidisciplinary assessment perspective, covering multiple spatial scales from the local to the mediterranean basin has been used to analyze changes in ES supply and demand. The revealed impacts of urbanization and commonly applied agricultural management systems negatively impact the supply of ES which may hinder the progress mediterranean countries strive for within the frame of the SDGs. Better management of land use systems along the rural-urban gradient and the engagement of stakeholders could help to assure progress towards the SDGs. The chosen methods and data affect the results with regards to ES trends, synergies and trade-offs detected. In this thesis I recognize the need to apply integrated ES assessment to provide the estimation of trends, and the existence of shared knowledge within stakeholder groups that can provide the much needed link between theory and practice

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Trade-offs in resource allocation underlie key life history traits of organisms. My dissertation focuses on the size-number trade-off in clonal broods of offspring using the polyembryonic wasp, Copidosoma bakeri parasitizing immature stages of the moth Agrotis ipsilon. I aim to characterize responses of wasp brood size and individual body mass by manipulating the environments in order to understand the allocation pattern in the size number trade-off. In reviewing the functional forms of trade-off relationships in relation to resource constraints, I distinguish among three main trade-off types based on graphical representations of the relationship between the trade-off variables: linear, convex (inverse), and concave. The size-number trade-off in C. bakeri shows convex relationship. Characteristics of the trade-off are sex specific: female broods have larger body mass but smaller brood size than do male broods. When food intake of the host was increased, the trade-off between wasp body mass and brood size for both sexes shifts toward both higher wasp brood size and higher body mass. When the host has better access to food late in development, the size-number trade-off curve moves up and to the right on the graph. However, the trait combinations shift along the same trade-off curve toward greater wasp body mass but smaller brood size when the host development time is shorter due to more resources in early in development. I also investigate temperature effects on the size-number trade-off. C. bakeri brood size significantly increases with high temperature early in host development. There is no shift in the allocation pattern of the size-number trade-off with temperature. Finally, I test effects of body mass on longevity, fecundity, and mating competitiveness of C. bakeri. Larger body size increases female longevity, and mated females produce more eggs than unmated females. There are no significant relationships between male body mass and longevity or mating competitiveness. Mating reduces male longevity independent of body mass. The different impact of body mass on fitness between male and female wasps suggests the observed sex-specific allocation patterns of the size-number trade-off. Implications of the experiments and possible follow-up work are discussed.

Plant secondary metabolites (SM) are widely used by humans in many ways (pharmacy, biotechnology etc.). For making their use even more effective, it is important to know the seasonality of these chemicals in plants and what affect those changes. Three Artemisia species (Artemisia annua, A. absinthium, A. vulgaris) were cultivated during one vegetation season (from April to September 2016). Plant growth parameters and the beginning of their generative stages were observed, and leaf samples were collected regularly. Samples of some plants were collected repeatedly. A generalist herbivore (migratory locust), was used as a proxy for studying changes in plant secondary metabolism during the vegetation season. The results proved presence of defence secondary metabolites in plants except A. vulgaris species where the role of SM in defence was not shown. Levels of SM changed nonlinearly during the vegetational season and were time-dependent. Plant size did not influence the levels of SM in plants. Levels of SM were low at the beginning of the experiment followed by rapid increase and remaining on maximal levels. The plants which lost their biomass repetitively grew slowly and bloomed later than the plants which were clipped only once. A delay trend showing seasonality of the plant SM was not proved. In...

The focus of this dissertation is on improving decision-maker trade-offs and the development of a new constrained methodology for multiple response surface optimization. There are three key components of the research: development of the necessary conditions and assumptions associated with constrained multiple response surface optimization methodologies; development of a new constrained multiple response surface methodology; and demonstration of the new method. The necessary conditions for and assumptions associated with constrained multiple response surface optimization methods were identified and found to be less restrictive than requirements previously described in the literature. The conditions and assumptions required for a constrained method to find the most preferred non-dominated solution are to generate non-dominated solutions and to generate solutions consistent with decision-maker preferences among the response objectives. Additionally, if a Lagrangian constrained method is used, the preservation of convexity is required in order to be able to generate all non-dominated solutions. The conditions required for constrained methods are significantly fewer than those required for combined methods. Most of the existing constrained methodologies do not incorporate any provision for a decision-maker to explicitly determine the relative importance of the multiple objectives. Research into the larger area of multi-criteria decision-making identified the interactive surrogate worth trade-off algorithm as a potential methodology that would provide that capability in multiple response surface optimization problems. The ISWT algorithm uses an ε-constraint formulation to guarantee a non-dominated solution, and then interacts with the decision-maker after each iteration to determine the preference of the decision-maker in trading-off the value of the primary response for an increase in value of a secondary response. The current research modified the ISWT algorithm to develop a new constrained multiple response surface methodology that explicitly accounts for decision-maker preferences. The new Modified ISWT (MISWT) method maintains the essence of the original method while taking advantage of the specific properties of multiple response surface problems to simplify the application of the method. The MISWT is an accessible computer-based implementation of the ISWT. Five test problems from the multiple response surface optimization literature were used to demonstrate the new methodology. It was shown that this methodology can handle a variety of types and numbers of responses and independent variables. Furthermore, it was demonstrated that the methodology can be successful using a priori information from the decision-maker about bounds or targets or can use the extreme values obtained from the region of operability. In all cases, the methodology explicitly considered decision-maker preferences and provided non-dominated solutions. The contribution of this method is the removal of implicit assumptions and includes the decision-maker in explicit trade-offs among multiple objectives or responses.

Ett företags kapitalstruktur är förhållandet mellan företagets eget kapital och skulder. Det finns huvudsakligen två teorier som förklarar företagens val av kapitalstruktur, trade off-teorin som utgår från en optimal skuldsättningsgrad och pecking order-teorin som utgår från företagets lönsamhet. Tidigare forskning ger ingen entydig bild av vilken teori som bäst förklarar kapitalstrukturen hos företag, dessutom saknas forskning på svenska företag. Syftet med denna studie är att undersöka vilken av teorierna som bäst förklarar större svenska företags kapitalstruktur. Vidare är syftet att undersöka om teorierna förklarar kapitalstrukturen olika bra beroende på vilken bransch som studeras. En multipel regressionsmodell med fem oberoende variabler som förklarar skuldsättningsgraden används. Resultatet visar på att det inte går att säkerställa vilken av teorierna som bäst förklarar kapitalstrukturen hos svenska större företag då vi finner stöd för båda teorierna. Vidare ger resultatet stöd för att de två teoriernas tillämpbarhet varierar beroende på vilken bransch som undersöks.

Invasive plants may leave enemies behind when they colonize a new habitat, allowing selection to favor increased investment in growth and/or reproduction over defensive traits. Previous studies have identified reduced diversity of potential bacterial pathogens and evolutionary increases in growth and reproduction in invading populations of yellow starthistle (Centaurea solstitialis). This study leverages a recently developed high-throughput assay of immune function to test for evidence of a trade-off between increased growth and defense against bacterial pathogens in yellow starthistle's invasion of California (USA). Seven bacterial strains were cultured from infected leaf tissue in the native range. Healthy leaf tissue from five native European collections and six invading collections were exposed to these native bacterial strains. A standardized assay of peroxidase activity was used measure the oxidative burst immune response to pathogen recognition by the leaf. Immune responses were compared to plant growth within and between ranges to assess evidence for a trade-off. Plant genotypes from the native range demonstrated a higher immune response to bacterial strains than did invading genotypes, consistent with a trade-off with plant growth across regions. The same trade-off was also apparent across genotypes from the native range, but not across genotypes from the invaded range. Our results provide evidence that increased growth in a highly invasive plant species may come at a cost to immune function, consistent with the hypothesis that escape from enemies can provide opportunities for shifts in resource allocation that favor the proliferation of non-native species.

The implementation of the mandatory alternative payment model (APM) guarantees savings for Medicare regardless of participant hospitals ability for reducing spending that shifts the cost minimization burden from insurers onto the hospital administrators. Surgical interventions account for more than 30% and 40% of hospitals total cost and total revenue, respectively, with a cost structure consisting of nearly 56% direct cost, thus, large cost reduction is possible through efficient operation management. However, optimizing operating rooms (ORs) schedules is extraordinarily challenging due to the complexities involved in the process. We present new algorithms and managerial guidelines to address the problem of OR planning and scheduling with disturbances in demand and case times, and inconsistencies among the performance measures. We also present an extension of these algorithms that addresses production scheduling for sustainability. We demonstrate the effectiveness and efficiency of these algorithms via simulation and statistical analyses.