In a changing climate, it is increasingly important to be able to model environmental effects on food webs, and to do that, one must have appropriate dynamic models. I present a shallow lake ecosystem model where producers, grazers, carnivores, piscivores, and detritivores are coupled through resource (light, nutrients and detritus) fluxes between the benthic and pelagic habitats and through carnivore life history events (ontogenetic habitat and diet shifts). The two habitats each contain primary producers, grazers, carnivores and detritivores. Within the habitats, there is strong top-down regulation, but across habitat boundaries, bottom-up interactions drive production. In the absence of piscivores, stage-structured carnivores cause intriguing patters of alternative stable states. Notably, the model predicts a lesser dependence on benthic production with detritus presence. Model predictions are largely in agreement with empirical studies. The results have implications for management of freshwater, and for the interpretation of previous models.

Esta dissertação desenvolveu duas análises de natureza diferente, mas complementares, uma vez que são unidas por uma mesma questão. Esta questão diz respeito à utilização do gás natural veicular em substituição ao óleo diesel em ônibus urbanos. O autor argumenta que, devido a suas características técnicas, o gás natural pode contribuir para a promoção de um transporte mais sustentável, mesmo que o gás natural seja um combustível igualmente não renovável, como o óleo diesel. Na primeira análise desenvolvida, utiliza-se uma metodologia bottom-up para demonstrar os ganhos ambientais que podem ser alcançados ao se substituir o óleo diesel por gás natural em ônibus urbanos. Adota-se a cidade de São Paulo como estudo de caso. Esses ganhos ambientais manifestam-se tanto na redução das emissões de poluentes locais, como material particulado, monóxido de carbono e óxidos de enxofre, conduzindo a melhoras importantes na qualidade de vida das pessoas que sofrem os efeitos nocivos dessas emissões (usuários ou não do transporte público urbano), como, também, no declínio das emissões de gases de efeito estufa, especialmente o dióxido de carbono, levando a benefícios ambientais globais. Os resultados amparam o uso do gás natural em ônibus como uma estratégia de maior sustentabilidade no plano ambiental. Já, na segunda análise desenvolvida, a pesquisa levanta as questões seguintes: Quais outros parâmetros influenciam a decisão de se promover a substituição de combustíveis em ônibus urbanos? Quais critérios explicam as escolhas por distintos combustíveis substitutos? As respostas a essas questões são obtidas através de uma Análise Qualitativa Comparativa (AQC). A pesquisa comparou 39 cidades em todo o mundo, que adotaram combustíveis substitutos ao óleo diesel em ônibus urbanos, incluindo o gás natural, biocombustíveis, eletricidade e hidrogênio. Os resultados atestam que as cidades de fato utilizam-se da substituição de combustíveis para tornar o transporte mais sustentável. Observa-se que a opção pelo gás natural é acolhida na maioria dos casos analisados como uma opção com vantagens ambientais e economicamente mais atrativa. A principal razão para sua eventual não adoção identifica-se com a insegurança energética. Algumas cidades receiam depender de um combustível que, assim como o petróleo (do qual o óleo diesel é um derivado), também está afeito a importantes suscetibilidades geopolíticas. A conclusão do trabalho reforça a importância do gás natural como um combustível ambientalmente mais amigável, e que pode contribuir na busca das cidades por sistemas de transporte público mais sustentáveis, especialmente em grandes áreas metropolitanas. Olhando, especificamente, o caso da cidade de São Paulo, com desdobramentos para o Brasil como um todo, a pesquisa enfatiza a necessidade de se superar barreiras regulatórias, e de se comprovar vantagens econômicas e de segurança de suprimento energético, para que o gás natural possa confirmar-se atrativo e mais sustentável aos olhares dos gestores dos sistemas de transporte público urbanos. Esses temas não podem ser deslembrados ao se propor uma política mais racional de combustíveis para o transporte público das grandes cidades brasileiras. / This work has developed two analyzes of different kinds, but complementary, since they are united by the same issue. This issue relates to the use of compressed natural gas to replace diesel fuel in city buses. The author argues that, due to its technical characteristics, natural gas can contribute to the promotion of more sustainable transport, even though the gas is a non-renewable fuel, such as diesel oil. In the first in-depth analysis, a bottom-up methodology is used in order to demonstrate the environmental benefits that can be achieved by replacing the diesel oil with natural gas in urban buses. The city of São Paulo is adopted as a case study. These environmental gains are manifested both in reducing emissions of local pollutants such as particulate matter, carbon monoxide and sulfur oxides, leading to significant improvements in quality of life of people suffering the harmful effects of the emissions (both public urban transport users and non-users), and also in the decline of emissions of greenhouse gases, especially carbon dioxide, leading to global environmental benefits. The results bolster the use of natural gas buses as a more sustainable strategy in environmental terms. In the second developed analysis, the research raises the following questions: What other parameters influence the decision to encourage the substitution of urban buses in fuels? What criteria explain the choices for different substitute fuels? The answers to these questions are obtained from a Qualitative Comparative Analysis (QCA). The study compared 39 cities across the world that have adopted fuel substitutes to diesel fuel in urban buses, including natural gas, biofuels, electricity and hydrogen. The results show that in fact, cities are use fuel shifting as a way to turn its transport system more sustainable. It is observed that the option for natural gas is considered, in most analyzed cases, as an option with environmental advantages and economically more attractive. The main reason for natural gas non-adoption was identified as energy insecurity. Some cities fear depending on a fuel that, like petroleum (of which diesel oil is a derivative), is also sensitive to relevant geopolitical issues. The conclusion of the work reinforces the importance of natural gas as a more environmentally friendly fuel, and can contribute to the promotion more sustainable public transport systems in cities, especially in large metropolitan areas. Looking specifically at the case of the city of São Paulo, as well as considering Brazil as a whole, the research emphasizes the need to overcome regulatory barriers, and to prove economic benefits and energy supply security, so that the natural gas can confirm is attractive and more sustainable to the eyes of managers of urban public transport systems. These issues cannot be forgotten in order to propose a more rational policy of fuel for public transport in large Brazilian cities.

Inom disciplinen kognitiv hörselvetenskap tillämpas en integrerad ansats där taluppfattning beskrivs ur både ett auditivt bottom-up-perspektiv och ett kognitivt top-down-perspektiv. Studien undersökte hur taluppfattning varierar med, respektive utan top-down-stöd och vad de kognitiva förmågorna uppmärksamhet, minne och inhiberingsförmåga hade för inverkan. Taluppfattningsförmåga utvärderades med hjälp av ett Speech-In-Noise-test (SIN-test) som bestod av tre deltest där enstaviga ord presenterades i en ofördelaktig miljö bestående av röster som talande i mun på varandra. I deltest 1 presenterades ord i uppåtgående förhållande till rösterna utan kognitivt stöd, i deltest 2 presenterades ord i nedåtgående förhållande till rösterna med kognitivt stöd och i deltest 3 presenterades ord i uppåtgående förhållande till rösterna med kognitivt stöd. Detta resulterade i identifiering av tre tröskelnivåer för taluppfattning. Kognitiva förmågor utvärderades med hjälp av Reading span test, Size Comparison span task (SIC-span) och Paced Auditory Serial-Addition Test (PASAT). Envägs variansanalys av taluppfattningstesten visade på signifikanta skillnader mellan alla tre testen. I test 2 identifierades lägst tröskelvärde, därefter test 3 och slutligen test 1. Korrelationsanalys visade på icke signifikanta samband mellan de tre SIN-testen. Av de kognitiva förmågorna och SIN- testen visade endast PASAT A på ett signifikant samband med SIN-test 2. Analys av de kognitiva förmågorna och differenserna mellan SIN-testen gav inga signifikanta samband. Slutligen vid analys av de kognitiva förmågorna hade PASAT A och PASAT B ett starkt positivt samband medan PASAT B och Reading span test hade ett starkt negativt samband. Resultaten i studien talade för att top-down-stöd ger bättre taluppfattningsförmåga och att uppmärksamhetskapacitet är en förmåga som har en signifikant inverkan på taluppfattning i nedåtgående förhållande till ett brus av röster.

<p>An influence at one trophic level can result in dynamic impacts also on other components of a food web. These dynamics are known as trophic cascades, and can be both top-down and bottom-up. After a near-collapse of the Baltic cod <i>Gadus morhua</i> stock in the 1980s, its main prey sprat <i>Sprattus sprattus</i> increased dramatically. The main food of sprat, marine copepods, decreased during the same time period, likely a combined effect of increased predation pressure from sprat and decreasing salinities. This shortage of food for sprat resulted in decreasing quality of sprat as a food source for common guillemots <i>Uria aalge</i>. However, a recent increase in fishing for sprat has again resulted in better feeding conditions for guillemots.</p><p>Human impacts on this simple food web can be complex. In the early 20th century, marine mammals were abundant and nutrient levels were low in the Baltic Sea. This thesis illustrate that this situation corresponded to lower fish biomass. A reduction of seals early in the century led to reduced top-down control, which resulted in increasing fish stocks. Later, in the 1950s, the largest inflow of salt water during the century mobilized accumulated phosphorus from the deep sediments, which stimulated nitrogen fixation. Combined with increasing anthropogenic nutrient loads, this led to increased primary production and a rapid change from an oligotrophic to a eutrophicated state. This change can be termed a regime shift, which also stimulated fish production. Subsequent over-fishing of cod likely caused a second regime shift, from a cod- to a clupeid- dominated state, which led to the described effects on the common guillemots.</p><p>Several factors affect the life-history of this long-lived seabird. Bycatches in gillnet fisheries is one factor directly affecting guillemot survival, and the proportion of bycatches increased during a period of increasing fishing effort. Surprisingly, avian cholera, a previously undocumented disease in common guillemots, was found at times to cause considerable adult mortality. Common guillemot life-history information can communicate the diversity of factors influencing marine ecosystems – hopefully this can increase our understanding of how complex even "simple" food webs are.</p>

Le travail de thèse consiste à construire un modèle pour une prospective énergétique à long terme dans le but d'estimer l'effet des politiques énergétiques et environnementales sur les choix technologiques futures des secteurs industriels. L'accent a été mis sur les industries grandes consommatrices d'énergie (IGCE), pour 29 pays européen et pour un horizon de temps allant jusqu'à 2050. L'outil de modélisation appliqué dans cette étude est le modèle TIMES (famille du modèle MARKAL, il s'agit d'un générateur de modèle d'optimisation de type Bottom-up basé sur la programmation linéaire). L'étude est réalisée dans le cadre d'un partenariat entre EDF R&D et le Centre de Mathématiques appliquées (CMA) de l'Ecole des Mines de Paris. Dans notre analyse, nous avons identifié pour chaque secteur industriel, plusieurs technologies concurrentes. Elles sont choisies par le modèle sous la base de leur coût global actualisé en intégrant l'ensemble des contraintes (prix d'énergie, taxe sur le CO2, plafond sur les émissions...). La capacité à installer dépend étroitement de la demande finale qu'il faut satisfaire pour chaque période sur l'ensemble de l'horizon de temps considéré. Selon les contraintes imposées, les résultats obtenus permettent de : <br/>- tracer l'image de l'industrie (profil de production technologique), <br/>- calculer les consommations énergétiques et les potentiels d'économies d'énergies réalisables, <br/>- estimer les émissions de dioxyde de carbone résultantes. Ce travail indique qu'il existe encore un important potentiel d'économies d'énergie et de réductions des émissions de dioxyde de carbone dans l'ensemble des secteurs industriels.

<p><strong>Abstract</strong></p><p><em>Bachelor thesis in political science by Alexander Hassan, autumn 2008, “Effects of external factors on a nations democratisation process during the transition from authoritarian to electoral democratic rule – A categorical analysis”</em></p><p><em>Supervisor: Tomas Sedelius</em></p><p>In recent years globalization has become a hot topic in understanding the world we live in today. Globalization has indeed had a great impact on international relations and with it a great influence on the domestic conditions that determine a nation’s possibilities. It is therefore rational to hold true that this also would apply to a nation’s democratic process. This basic notion is what lies as a foundation for the thesis, where the purpose of the study is to examine the relatively new field of the international context and its significance on democratisation.</p><p>The aim of the study is to examine and determine, through a categorical analysis, the different forms and roles that the external factors can take during the process leading up to the transition and implementation of an electoral democracy, the most basic form of democracy.</p><p>The thesis thus has demanded the study and infusion of all discourses within the field of democratisation processes, as the only way to produce the roles and forms of the international contexts impact on the domestic process is through the study and determination of the different domestic spheres associated with the process.</p><p>The different forms of external influences have been studied within the confines of the third wave of democracy, and their roles in the democratic process determined depending on the respective domestic spheres they affect. The significant result of the studies where chiefly that all forms of external influence have the possibility to affect the democratisation process indirectly as well as directly. Where direct influence is exerted within the political sphere of the nation; where the actual transition takes place, and the indirect influence is exerted through the socio-economical and cultural sphere; which exerts its influence in the process through the political sphere. </p><p>The results thus show that it is hard to draw the conclusion that an indirect form of influence would be superior to the direct approach or vice versa, as both are prevalent in successful democratic transitions.</p>

An influence at one trophic level can result in dynamic impacts also on other components of a food web. These dynamics are known as trophic cascades, and can be both top-down and bottom-up. After a near-collapse of the Baltic cod Gadus morhua stock in the 1980s, its main prey sprat Sprattus sprattus increased dramatically. The main food of sprat, marine copepods, decreased during the same time period, likely a combined effect of increased predation pressure from sprat and decreasing salinities. This shortage of food for sprat resulted in decreasing quality of sprat as a food source for common guillemots Uria aalge. However, a recent increase in fishing for sprat has again resulted in better feeding conditions for guillemots. Human impacts on this simple food web can be complex. In the early 20th century, marine mammals were abundant and nutrient levels were low in the Baltic Sea. This thesis illustrate that this situation corresponded to lower fish biomass. A reduction of seals early in the century led to reduced top-down control, which resulted in increasing fish stocks. Later, in the 1950s, the largest inflow of salt water during the century mobilized accumulated phosphorus from the deep sediments, which stimulated nitrogen fixation. Combined with increasing anthropogenic nutrient loads, this led to increased primary production and a rapid change from an oligotrophic to a eutrophicated state. This change can be termed a regime shift, which also stimulated fish production. Subsequent over-fishing of cod likely caused a second regime shift, from a cod- to a clupeid- dominated state, which led to the described effects on the common guillemots. Several factors affect the life-history of this long-lived seabird. Bycatches in gillnet fisheries is one factor directly affecting guillemot survival, and the proportion of bycatches increased during a period of increasing fishing effort. Surprisingly, avian cholera, a previously undocumented disease in common guillemots, was found at times to cause considerable adult mortality. Common guillemot life-history information can communicate the diversity of factors influencing marine ecosystems – hopefully this can increase our understanding of how complex even "simple" food webs are.

The aim of this thesis is to study the risk for two Swedish companies, Axfood and Volvo. To test the required return on equity, a bottom-up beta approach and a CAPM regression beta are used. This thesis concludes that the bottom-up beta gives a truer reflection and a more updated beta value than a CAPM regression beta on the firm’s current business mix, the CAPM beta takes only the past stock prices into consideration. The empirical results for Volvo conclude that the levered bottom-up beta is 1.09 and the CAPM β is 0.52 for Volvo. The empirical results for Axfood which is categorized as consumer goods sector implies that the levered bottom-up beta is 0.87 while the CAPM regression beta is 0.29.

L’esperienza estetica è un fenomeno complesso e articolato, caratterizzato da un particolare intreccio di processi percettivi, emotivi, cognitivi. Il dibattito sulla definizione del ruolo dei fattori che intervengono nell’esperienza estetica è molto controverso: diverse cornici teoriche enfatizzano o il ruolo dei fattori "bottom-up", riguardanti le caratteristiche visive e strutturali dell'opera d'arte come il colore e simmetria, o il ruolo dei fattori "top-down", relativi al bagaglio di conoscenze ed esperienze personali. Questa tesi presenta due studi volti ad approfondire, attraverso l'analisi dei movimenti oculari, l'influenza dei processi "bottom-up" e "top-down" sul comportamento visivo di adolescenti o adulti non esperti d’arte durante l'osservazione di opere d’arte pittorica. I dati ottenuti suggeriscono che processi intersoggettivi e relazionali giocano un ruolo essenziale nel guidare l’apprezzamento estetico di un quadro. Questi risultati innovativi supportano alcune recenti ipotesi teoriche relative alla natura intrinsecamente intersoggettiva dell’esperienza estetica. / Experiencing art is a complex and articulated phenomenon characterized by a peculiar weaving of perceptive, emotional, and cognitive processes. The debate on the definition of factors that contribute to the surfacing of an aesthetic experience is very controversial, partly because of the different weights assigned to the elements in the competition between “bottom-up” and “top-down” processes. Different theoretical frames emphasize the role of bottom-up factors - concerning the visual and structural characteristics of the artwork such as colour and symmetry - or top-down cognitive processes - concerning the cognitive feedback deriving from everyone’s cultural background and knowledge - in the building up of an aesthetic experience. In this work, two studies aiming at shedding some light on art appreciation are presented. These studies were designed to investigate, by means of the analysis of eye-movements, the influence of bottom-up and top-down processes on visual behavior while adolescents or adults naïve to art criticism were presented with representational paintings. Data suggest that intersubjective and relational processes intervene in first stages of aesthetic experience. These important and novel results support new theoretical proposals, which consider embodied intersubjective processes underpinning aesthetic experience.

The aim of this Bachelor thesis is to find keys to successful advocacy in a rural, Indian setting. The study is based on inductive, explorative research at a grassroots level, from a bottom-up perspective. Geographically, it takes place in the East Godavari District, in the state of Andhra Pradesh. At the centre of this study is the NGO:s Sujana and the Kadali Network, who are both advocating the rights of poor, marginalised and deprived people, as well as training people to carry out advocacy themselves. The theoretical framework for this thesis originates from theories within development communication, advocacy and Participatory Rural Appraisal. The research was carried out by making 16 individual interviews and 3 focus group interviews.  Findings from the interviews have been categorised into themes and analysed through meaning condensation. The result of this study shows that there are multiple ways in which grassroots movements in East Godavari conduct advocacy. The analysis states that advocacy can be successful in a short to medium time span; the most prominent keys to success being: having a driving spirit, being creative, developing networks and being knowledgeable about laws and rights. In a longer time span though, the advocacy and struggle for change is hampered by lack of, or conflicting, political interest from the local government and by conflicting economical interests from companies.