This collection of studies was designed to understand the mechanisms and consequences of competition among early life stages of red drum (Sciaenops ocellatus), with a special attention to asymmetric competition and multiple-breeding strategy of parents. The overall hypotheses were that (1) red drum larvae show behavioral interactions, and the magnitude of these interactions is explained by the sizes of the competing individuals, (2) red drum larvae compete for food and habitat use, and the competition is asymmetric as determined by size and behavioral interactions, and (3) the parents can reduce negative effects of competition among larvae and increase larval survival by altering their multiple-spawning traits. The laboratory experiments showed the existence of sociality in red drum larvae. The magnitudes of aggressive behavior, vigilant behavior and shoaling behavior were explained by a combination of absolute and relative phenotypes of competing individuals, such as body lengths and body condition. A new method of combining the laboratory experiments and the foraging theory disentangled interference competition for food from exploitative competition, revealing that both absolute and relative body lengths of competing individuals influence feeding efficiencies. In addition, vigilant behavior decreased feeding efficiency regardless of body sizes. The competitor size and behavioral interactions between individuals had different effects on competition for habitat use: the existence of larger individuals prevented the newly settled larvae from entering preferred habitats, whereas the aggressive behavior from the occupants of preferred habitats moved newly settled larvae to the unpreferred habitats. Finally, computer simulations using an individual-based model revealed that as interference competition among larvae increased, the number of spawning events and the spawning interval of the parents increased to lessen competition and maximize total survival of offspring. / text

Orientador: João Frederico da Costa Azevedo Meyer / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica / Made available in DSpace on 2018-08-23T13:46:24Z (GMT). No. of bitstreams: 1 Santos_CarlosFrankLimados_M.pdf: 3104358 bytes, checksum: a690d16041a50b1c06291d1d64615b29 (MD5) Previous issue date: 2013 / Resumo: O propósito deste trabalho é desenvolver uma modelagem matemática que descreverá computacionalmente o convívio entre duas espécies competidoras sem característica migratória diante da variação de densidade de vegetação. As equações utilizadas nesta modelagem incluíram os fenômenos de difusão de vegetação, processos de dispersão populacional, dinâmicas vitais e um decaimento proporcional a variação de densidade de mata, no sentido de que quanto maior a densidade de mata menor o decaimento populacional quanto menor a densidade de mata maior a mortalidade populacional. Para as espécies competidoras usaremos as clássicas modelagem do tipo Lotka-Volterra (não- linear) combinado a equação diferenciais parciais de difusão-advecção. Primeiramente faremos a descrição do modelo matemático e a descrição do domínio visando o uso do método de diferenças finitas para o espaço combinados a um modelo de Crank-Nicolson no tempo. Em seguida, desenvolveremos um algoritmo em ambiente MATLAB , que aproxima as soluções relativas a difusão de vegetação e a cada população em cada ponto e ao longo do tempo considerado nas simulações. Por fim, foram obtidos resultados gráficos que foram analisados o efeito da recuperação da mata no convívio das espécies competidoras consideradas. De modo que se disponha de ferramentas mais acessíveis a profissionais e pesquisadores ligados aos estudos de ecologia matemática e meio ambiente, bem como aos responsáveis pelas adoções de medidas de emergências e contingências de áreas destruídas pelas ações antrópicas / Abstract: The main objective of this work is that of obtaining an adequate mathematical model and, consequently, a computational algorithm to describe the interaction between two competing species in face of a density variation in vegetation. Population dispersal and dynamics and the presence of a term relating the loss of vegetation density to higher mortality for both competing species must be considered, as well as the inverse: a raise in vegetation density is bound to increase the survival of species. In order to describe the interaction between vegetation and animals, a classic Lotka-Volterra system is used, coupled with the use of the diffusion-reaction partial differential equation for all three participants considered in the model: vegetation density and both animal species. For the interacting animal species, no migration is considered, although the possibility of a preferential direction similar to an advective component is permitted in the dispersal of plants. Numerical discretization include centered finite differences in order to obtain second order approximations in space variables, as well as a Crank-Nicolson method, also second order, for approximations in time. In order to qualitatively analyze possible results, a MATLAB environment was used, with the possibility of exhibiting graphical results based on the numerical ones. This is done in order to create a numerical auxiliary tool which can be used by researchers and professional agents in the evaluation of ecological and environmental policies and decisions, as well as the description of some of the effects of anthropic a actions / Mestrado / Matematica Aplicada / Mestre em Matemática Aplicada

The objective of this thesis is mapping of the situation about customer competition. Attention is first employed on a marketing communication and then is entertained about sales promotion of a final consumer with specification - customer competition. Authoress devotes to legislative framework, organization, problematic areas of consumer competition. In the next part of this thesis is took over the interview, which has clear up the attitude of questionedes towards customer competition.

Doctor of Philosophy / Department of Economics / Philip G. Gayle / This dissertation seeks to answer questions regarding changes in the competitive environment in international air travel markets which has undergone rapid changes since the early 1990s. Specifically, the research in this dissertation examines policies regarding cooperation among airlines in international air travel markets as well as how cooperation affects an airline's product quality. These issues are explored in two essays which comprise my dissertation. The first essay explores the efficacy of a policy known as a carve-out. Airlines wanting to cooperatively set prices for their international air travel service must apply to the relevant authorities for antitrust immunity (ATI). While cooperation may yield benefits, it can also have anti-competitive effects in markets where partners competed prior to receiving ATI. A carve-out policy forbids ATI partners from cooperating in markets policymakers believe will be most harmed by anti-competitive effects. We examine carve-out policy applications to three ATI partner pairings, and find evidence of tacit collusion in carve-out markets in spite of the policy, calling into question whether consumers benefited from application of the policy in the cases studied. The second essay examines the relationship between product quality and airline cooperation. Much of the literature on airline cooperation focuses on the price effects of cooperation. The key contribution of our paper is to empirically examine the product quality effects of airline cooperation. Two common types of cooperation among airlines involve international alliances and antitrust immunity (ATI), where ATI allows for more extensive cooperation. The results suggest that increases in the membership of a carrier's alliance or ATI partners are associated with the carrier's own products having more travel-convenient routing quality. Therefore, a complete welfare evaluation of airline cooperation must account for both price and product quality effects.

Call number: LD2668 .T4 1978 S87 / Master of Science

This paper examines the relation between competition in the banking sector and the financial stability on country level. Compared to previous research, it takes a different approach in that it uses realized systemic risk in the form of systemic banking crises instead of the total systemic risk. Theory provides us with two opposing theories regarding the role of competition on stability. Previous studies presented mixed results which leaves us with unresolved questions which this paper tries to answer. The results show that there is evidence for both views, but without giving an all comprehending answer.

INTRODUCTION:Honey bees, Apis mellifera, have a diverse community of pathogens. Previous research has mostly focused on bacterial brood diseases of high virulence, but milder diseases caused by fungal pathogens have recently attracted more attention. This interest has been triggered by partial evidence that co-infection with multiple pathogens has the potential to accelerate honey bee mortality. In the present study we tested whether co-infection with closely related fungal brood-pathogen species that are either specialists or non-specialist results in higher host mortality than infections with a single specialist. We used a specially designed laboratory assay to expose honey bee larvae to controlled infections with spores of three Ascosphaera species: A. apis, the specialist pathogen that causes chalkbrood disease in honey bees, A. proliperda, a specialist pathogen that causes chalkbrood disease in solitary bees, and A. atra, a saprophytic fungus growing typically on pollen brood-provision masses of solitary bees.RESULTS:We show for the first time that single infection with a pollen fungus A. atra may induce some mortality and that co-infection with A. atra and A. apis resulted in higher mortality of honey bees compared to single infections with A. apis. However, similar single and mixed infections with A. proliperda did not increase brood mortality.CONCLUSION:Our results show that co-infection with a closely related fungal species can either increase or have no effect on host mortality, depending on the identity of the second species. Together with other studies suggesting that multiple interacting pathogens may be contributing to worldwide honey bee health declines, our results highlight the importance of studying effects of multiple infections, even when all interacting species are not known to be specialist pathogens.

We propose a new measure, called the Container Port Connectivity Index (CPCI), to more accurately reflect the relative importance of container ports within the global network of container shipping. This index is based on both economics and network topology, where the strength of a port is based on its position within the global structure of shipping network and not just on local information, such as the number of TEUs handled or direct links to other ports. As the CPCI produces two separate scores for each inbound and outbound connectivity, we can use them to analyze the economic roles played by each port independently. We also propose a framework for evaluating market stability of a logistics hub in a competitive environment. In particular, we build a model, called the Liner Shipping Cooperative Model, to predict how the community of liners calling at a hub might develop as the result of actions by competitors. We use such a model to study the behavior of shipping lines, as well as the resulting trade-flow changes, as the system gradually moves toward new equilibrium defined by the grand coalition. With this piece of information, a port authority would be able to quantify threats posed by competitors and, consequently, devise counter strategies to safeguard its business against competing ports.

State Aid policy has been an integral part of competition policy and the European Commission is responsible for controlling aid, which distorts competition in the internal market to be granted by Member States. State Aid is usually defined as advantages given by the State to undertakings in the form of financial contributions, support, or other forms of special treatment. This thesis will examine state aid policy and regulation in the European Union. The research aims at critically analysing the implementation of the rules that compose the European state aid framework and conclude on whether the system for the control of state aid is set in an effective way to achieve the objectives of protecting competition and therefore the internal market by limiting aid levels and streaming aid towards more beneficial aid. This research is important because it can reveal the particular benefits and problems caused by state aid and help by making recommendations for the future application of the rules.

Master of Science / Department of Journalism and Mass Communications / Angela Powers / Technological revolutions of the past century have fueled dynamic paradigm shifts across a broad spectrum of mass media industries. This study examines an innovative new market segment in the music recording industry: digital music aggregation. Digital music aggregators are music distributors that directly connect artists, any creator of musical content, to digital music vendors, online music stores such as iTunes or digital music streaming services such as Spotify. Digital music aggregator companies offer services similar to major record labels, such as mass distribution, royalty collection, and intellectual property protection. Digital music aggregators provide services to artists at all levels of prestige and experience. Essentially any artist interested in publishing music can do so using digital music aggregators. Despite their growing influence in the music recording industry, digital music aggregators have been afforded little scholarly attention. This study responds to Galuszka's (2015) call for further research on aggregator market structure and competition, proposing the following research questions: 1) how is the digital music aggregator market structured? 2) What competitive strategies do digital music aggregators employ? This study is framed by the industrial organizational model of market structure (Bain, 1968) and Porter’s (1980) theories of competitive strategy. Six in-depth qualitative interviews were conducted for this study. Results illuminate market structure and competitive strategies in the digital music aggregation industry and lay foundation for future study and industrial application within this nascent branch of the music recording industry.