Various aspects of performance (e.g., sprint speed, grip strength) are thought to be important determinants of the success of animals in natural activities such as foraging, mating, and escaping from predators. However, it is generally known that morphological properties enhancing one type of performance (e.g., speed) can lead to a reduction in another (e.g., strength). Such performance trade-offs have been quantified at the inter-specific level, but evidence at the inter-individual level remains equivocal. To test for the presence of a performance trade-off, I initiated a study on wild white-footed mice (Peromyscus leucopus). In summer 2016, I captured a total of 186 individuals, 87 of which were repeatedly phenotyped for grip strength and sprint speed. A significant positive relationship was found between body mass and grip strength (but not for sprint speed). Individual differences in performance were repeatable through time for both grip strength and sprint speed. Using a bivariate mixed model, I detected a significant negative correlation between grip strength and sprint speed at the among-individual level. By contrast, the within-individual correlation between grip strength and sprint speed tended to be positive, suggesting that some unquantified aspects of the mouse phenotype (e.g., body condition, age) may have a positive effect on both performance traits. Given the relatively low repeatability of grip strength and sprint speed, a failure to properly partition the correlation at the among- and within-individual level generates a counter-intuitive, positive correlation. This study is one the first to detect a performance trade-off at the among-individual level in a wild animal population.

Hur ett företag väljer att finansiera sig och forma sin kapitalstruktur skiljer sig åt mellan företag och regioner. Med denna uppsats vill vi bidra till att fylla det tomrum som finns i forskningen kring kapitalstruktur för företag primärnoterade på Nasdaq Stockholm. Genom en kvantitativ ansats undersöker vi skillnader i kapitalstruktur utifrån ägarkoncentration, om största ägaren är en familj som kontrollerar bolaget samt om lönsamhet och mognadsgrad påverkar kapitalstrukturen. Vi använder multipel linjär regressionsanalys med ett urval om totalt 1012 observationer från räkenskapsåren 2009-2014, samt kontrollerar för fasta års- och branscheffekter. Vår studie finner att mogna företag i genomsnitt har en signifikant högre skuldsättning, däremot finner vi till skillnad från liknande studier att lönsamhet inte har en signifikant påverkan på ett företags skuldsättning. Vidare visar våra resultat att skuldsättningen sjunker med ökad ägarkoncentration samt att den är högre om företaget har en kontrollerande ägare som är en familj relativt icke-familj.

Denna studie undersöker hur kapitalstrukturen bland företag noterade på Stockholmsbörsenförändrades till följd av den globala finanskrisen 2008-2009. Studien utgår från femfinansiella mått som bidrar till att förklara företagens skuldsättning, hur måttens sambandmed skuldsättningen ser ut och hur dessa samband förändrats till följd av finanskrisen.Genom en multipel regressionsanalys finner studien signifikant förändrade samband medskuldsättning för måtten lönsamhet, företagsstorlek och market-to-book-kvot. Genomytterligare en multipel regression kan studien även dra slutsatsen att skuldsättningen minskatunder finanskrisen utan spår av återhämtning fram till 2012. Resultatet ger stöd för trade-offteorinoch enbart svagt stöd för pecking order-teorin och market timing-teorin. Studiensresultat skiljer sig på flera punkter från resultat i liknande studier gjorda på företag i andraländer.

A compreensão da dinâmica populacional é fundamental para a conservação da biodiversidade, uma vez que as espécies são perdidas através de processos que ameaçam suas populações. Portanto, compreender como as condições ambientais determinam a dinâmica populacional é essencial, especialmente tendo em conta o cenário de mudanças climáticas. Um parâmetro populacional importante é a reprodução, que não só contribui para o tamanho da população, mas também pode afetar a condição corporal e a probabilidade de sobrevivência. Devido aos altos custos energéticos, a reprodução é freqüentemente associada com a disponibilidade de alimentos em ambientes tropicais, que por sua vez é altamente correlacionada com as condições climáticas, especialmente a precipitação. Além disso, o estudo de processos de populações ou comunidades requer dados de boa qualidade, que para vários grupos de animais depende da compreensão das interações entre os métodos de captura, condições climáticas e as características morfológicas e comportamentais de indivíduos e espécies. Através de um conjunto de dados de captura e recaptura de pequenos mamíferos em uma reserva de Mata Atlântica, compreendendo três grades de 2ha amostrados por quase dois anos, esta tese tem como objetivos contribuir com o entendimento: (1) de como as condições ambientais afetam a dinâmica de populações, especialmente a sobrevivência e reprodução, mais especificamente, como as condições climáticas afetam a demanda conflitante (trade-off) entre a sobrevivência e reprodução e quais são as gatilhos ambientais do início da reprodução, (2) de como o tipo de armadilha, características individuais e as condições climáticas interagem para determinar o sucesso de captura, visando a definição de diretrizes de protocolos de captura eficientes para a amostragem de pequenos mamíferos. No primeiro capítulo, mostramos que a precipitação afetou negativamente as taxas de sobrevivência, positivamente a freqüência de fêmeas reprodutivas e não afetou a condição corporal, o que sugere a existência de uma demanda conflitante entre sobrevivência e reprodução em populações de roedores. No segundo capítulo, corroboramos que a reprodução de marsupiais da Mata Atlântica é sazonal e sincrônica, ocorrendo no período quente e úmido, e seu gatilho é o fotoperíodo. Também apresentamos evidências de semelparidade em marsupiais de pequeno porte. No terceiro capítulo, mostramos que a eficiência de diferentes métodos de captura foi influenciada pelas condições climáticas, dependeu da idade e do sexo dos indivíduos e foi condicionada às variáveis quantificadas (número de espécies, de indivíduos ou de recapturas). Os resultados destacam a importância de armadilhas de queda para os estudos de comunidades e a utilização conjunta de armadilhas de queda e Sherman para estudos populacionais. / The understanding of population dynamics is central for biodiversity conservation, since species are lost through processes that threat their populations. Understanding how environmental conditions determine population dynamics is thus essential, especially given the climate change scenario. One important population parameter is reproduction, which not only contributes to population size, but can also affect body condition and survival probability. Given its high energetic costs, reproduction is frequently associated with food availability in tropical environments, which in turn is highly correlated to weather conditions, especially rainfall. However, studying population or community processes requires good-quality data, which for several animal groups depends on understanding the interactions among trapping methods, weather conditions and morphological and behavioral characteristics of individuals and species. Through a capture-recapture dataset on small mammals in an Atlantic Forest reserve, comprising three 2ha grids sampled for almost two years, this thesis aim at understanding: (1) how environmental conditions affect population dynamics, especially survival and reproduction; more specifically, how weather conditions affect the trade-off between survival and reproduction, and which are the environmental triggers for reproduction; (2) how the type of trap, individual traits and weather conditions interacts to determine capture success, aiming at defining guidelines for efficient protocols for small mammal sampling. In the first chapter, we show that rainfall negatively affected survival rates, positively affected the frequency of reproductive females and did not affect body condition, suggesting the existence of a trade-off between survival and reproduction in rodent populations. In the second chapter, we corroborated that reproduction of Atlantic Forest marsupials is seasonal and synchronous, occurring in the warm-wet season, and triggered by photoperiod cues. We also bring evidence for semelparity in small-sized marsupials. In the third chapter, we show that the efficiency of different trap methods was influenced by weather condition, depended on the age and sex of individuals, and was contingent on the quantified variables (number of species, of individuals or of recaptures). Results highlight the importance of Pitfalls for community studies and the joint use of Pitfall and Sherman traps for population studies.

Submitted by Cristiane Oliveira (cristiane.oliveira@fgv.br) on 2012-10-03T21:27:57Z No. of bitstreams: 1 1199900142.pdf: 4611819 bytes, checksum: a6b01b61e64428c19a1b1deae1874bc8 (MD5) / Approved for entry into archive by Vera Lúcia Mourão (vera.mourao@fgv.br) on 2012-10-03T21:29:40Z (GMT) No. of bitstreams: 1 1199900142.pdf: 4611819 bytes, checksum: a6b01b61e64428c19a1b1deae1874bc8 (MD5) / Made available in DSpace on 2012-10-03T21:38:36Z (GMT). No. of bitstreams: 1 1199900142.pdf: 4611819 bytes, checksum: a6b01b61e64428c19a1b1deae1874bc8 (MD5) Previous issue date: 1997 / Examina as diversas abordagens teóricas em defesa da relevância da estrutura de capital para a determinação do valor da empresa. Preocupa-se especificamente em identificar quais são os fatores determinantes da escolha da estrutura de capital das empresas não-financeiras no Brasil, procurando, quando possível, encontrar evidências de que tal escolha possa ser explicada pelas hipóteses do 'static trade-off’ e/ou da 'pecking order' modificada.

Made available in DSpace on 2014-06-12T17:43:10Z (GMT). No. of bitstreams: 2 arquivo986_1.pdf: 958504 bytes, checksum: 99d996fb804796538d0c574efd58f381 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Os investimentos em ativos e nas atividades operacionais de uma empresa podem ser financiados por meio de capitais próprios ou capitais de terceiros, que juntos constituem a estrutura de capital da organização. Na teoria de finanças são identificadas duas grandes correntes de pensamento: a teoria tradicional e a teoria de Modigliani & Miller, as quais divergem por aceitar e rejeitar, respectivamente, a possibilidade de existência de uma estrutura ótima de capital, em que o custo de capital é minimizado e a riqueza dos acionistas maximizada. Com base no referencial teórico existente, este trabalho estudou a estrutura de capital e seus determinantes, considerando uma amostra de 1.771 empresas brasileiras de pequeno, médio e grande porte, dos setores de indústria, comércio e serviços. Os atributos testados nesta pesquisa como determinantes da estrutura de capital foram tangibilidade dos ativos, rentabilidade, tamanho e liquidez. Foi desenvolvido modelo estatístico de regressão linear múltipla, apresentando graus de explicação e significância compatíveis para a identificação de elementos determinantes da estrutura de capital das empresas brasileiras. Foi confirmada a existência de relação positiva entre o endividamento e os atributos tangibilidade dos ativos e tamanho das empresas, ratificando o previsto pela teoria do Trade-Off, principal representante da corrente tradicionalista. Também foi corroborada a relação negativa entre endividamento e os atributos rentabilidade e liquidez, ratificando o esperado pela teoria do Pecking Order. Os resultados desta pesquisa refutaram a existência de relação positiva entre endividamento e rentabilidade das empresas, conforme previsto pela teoria do Trade-Off

Performance is an organism’s ability to accomplish a particular task or behavior, and morphology can have a major impact on the performance of an organism. Salamanders are ecologically diverse and can feed using a variety of behaviors depending on the environment in which feeding occurs. Feeding is accomplished through the use of the hyobranchial apparatus, which lies along the oropharynx, and this structure can have competing roles; in aquatic environments the apparatus is used for suction feeding and works to depress the floor of the mouth, but during terrestrial feeding this structure projects the tongue forward out of the mouth. Diverse morphologies of the hyobranchial apparatus enable varying degrees of feeding performance, both in aquatic and terrestrial environments. For my dissertation I have investigated the interactions, and possible functional trade-offs, of feeding morphology and performance in salamanders of Family Salamandridae. These salamanders are an ideal system for studying the interactions of morphology and performance across different environments because they have diverse ecology, being either fully aquatic, semi-aquatic, or terrestrial as adults, as well as differences in hyobranchial apparatus morphology. In these studies I have quantified the morphology and performance of seven salamandrid species feeding in aquatic (Chapter 2) and terrestrial (Chapter 3) environments to assess the links between these two parameters, as well as investigated the evolutionary patterns of feeding morphology, performance, and behavior across the Salamandridae (Chapter 4) to better understand the co-evolution of these traits across water-land transitions. During aquatic feeding salamanders use rapid mouth opening and hyobranchial depression to expand the oropharynx and generate negative pressure, and fluid flow, into the mouth. I hypothesized that more robust hyobranchial apparatus would yield increased aquatic feeding performance in salamandrids. When compared to semi-aquatic newts, the fully aquatic species, Paramesotriton labiatus, had greater mineralization of the hyobranchial apparatus, as well as relatively narrower basibranchial and wider ceratobranchial I + II complexes. These morphological differences coincide with greater aquatic feeding performance. Kinematics from high-speed videography revealed that maximum mouth opening velocities and accelerations were approximately two and five times greater, respectively, in Paramesotriton, and hyobranchial depression acceleration was found to be approximately three times greater than in the semi-aquatic species Pleurodeles, Notophthalmus, Triturus, and Cynops. Using digital particle image velocimetry, peak and average fluid velocities generated in Paramesotriton during suction feeding events were found to be 0.5 m s-1 and 0.2 m s-1, respectively, doubling that of all semi-aquatic species. These findings reveal that specialized morphology increases aquatic feeding performance in a fully aquatic newt. Salamanders use the hyobranchial apparatus and its associated musculature for tongue projection during terrestrial feeding. Hyobranchial apparatus composition and morphology vary across species and different morphologies are better suited for feeding in aquatic versus terrestrial environments. I hypothesized that differences in hyobranchial apparatus morphology and function result in functional trade-offs in feeding performance. Specifically I predicted that semi-aquatic and aquatic salamandrids with hyobranchial morphology suited for aquatic feeding would have lower performance, in terms of tongue-projection distance, velocity, acceleration and power, compared to terrestrial salamandrids when feeding in a terrestrial environment. I found that semi-aquatic and aquatic newts had lower tongue projection performance when compared to the terrestrial salamanders Chioglossa lusitanica and Salamandra salamandra. The fully aquatic newt, Paramesotriton labiatus, has a robust, heavily mineralized hyobranchial apparatus and was unable to project its tongue during terrestrial feeding, and instead exhibited suction-feeding movements better suited for aquatic feeding. Conversely, terrestrial species have gracile, cartilaginous hyobranchial apparatus and enlarged tongue pads that coincided with greater tongue-projection distance, velocity, acceleration, and power. Chioglossa exhibited extreme tongue-projection performance, similar to that seen in elastically projecting plethodontid salamanders; muscle-mass-specific power of tongue projection exceeded 2200 W kg-1, more than 350 times that of the next highest performer, Salamandra, which reached 6.3 W kg-1. These findings reveal that two fully terrestrial salamandrids have morphological specializations that yield greater tongue-projection performance compared to species that naturally feed in both aquatic and terrestrial environments. Salamanders of the Salamandridae that feed in both aquatic and terrestrial environments employ different behaviors depending on the environment. Using phylogenetic comparative methods, I assessed the relationships between feeding morphology, kinematics, and performance, and the ecology and feeding behavior of salamandrids. I also examined the co-evolution of feeding morphology and performance within Family Salamandridae. Behavior appears to co-evolve with feeding musculature, velocity of feeding movements, and fluid velocity produced during aquatic feeding. Flow velocity produced during aquatic feeding was related to the cross-sectional area of the rectus cervicis muscles, which rapidly depress the hyobranchial apparatus during suction feeding. Salamandrids with greater cross-sectional area of these depressor muscles generate faster flow velocity in aquatic feeding. Conversely, the evolution of hyobranchial apparatus morphology is more closely linked to ecology than to behavior. These findings indicate that both behavior and ecology are important for understanding the evolution of morphology and feeding performance across Family Salamandridae.

Trade-offs prevent selection from driving all fitness-enhancing traits towards values that would maximize fitness. Life-history trade-offs, such as the one between survival and reproduction are well-studied, yet trade-offs can also involve behavioural or cognitive traits. Because males and females have different routes to successful reproduction, the optimal resolution of life-history trade-offs can differ between the sexes. However, shared genome can constrain the evolution of sex-specific adaptations. In this thesis, I explore the links between sex-specific life histories, cognition and behaviour. I start by linking sex differences in life histories to sex differences in learning performance in the outcrossing nematode Caenorhabditis remanei (Paper I). I report that age-related learning differs between the sexes and that it corresponds to sexual dimorphism in life history. Then, I use experimental evolution to select for learning performance to study the patterns of genetic correlations between learning and life-history traits in both sexes (Paper II). The results demonstrate the correlated evolution of sexual dimorphism in life history indicating sex-specific fitness costs and benefits of learning. In Paper III I use the fruit fly Drosophila melanogaster to ask about the extent to which cognitive and demographic aging are independent. The results reveal that selection for late-life reproduction alone bears no effect on late-life learning and that joint selection on late-life learning and reproduction does not yield lifespan benefits. The selection might have affected, however, female age-specific reproductive effort. Motivated by the questions on aging I proceed to ask why a potent lifespan extending drug – rapamycin affects sexes differently (Paper IV). I take a closer look at the trade-off between growth, lifespan and reproduction and propose that the sex experiencing a stronger relationship between size and fitness pays a higher cost of lifespan extension. Finally, I focus on another sex-specific trait – dispersal (Paper V). I conduct experimental evolution to uncover a negative genetic correlation between dispersal and reproduction and show sex-specific genetic variation for dispersal. In summary, my thesis unravels the complex pattern of interdependence between life-history, behavioural and cognitive traits, where sex emerges as an important factor that can maintain genetic variation for trade-offs.

This thesis examines the determinants of capital structure in the MENA coun- tries. The main interest is to investigate both financial firms specially banks and non-financial firms. This study test the main theories of capital structure, namely: trade off theory and pecking order theory. The countries included in this thesis are Saudi Arabia, United Arab Emirates (Include both Abo-Dhabi and Dubai stock indexes), Bahrain, Qatar, Kuwait, Oman, Egypt, Morocco, Tunisia, Palestine and Jor- dan. The characteristics it covers as suggested by previous literature are tangibility, profitability, risk, debt tax shield, growth, dividends,size, cash flow and liquidity. It will also investigate the effect of the industry, credit rating and ownership structure on the capital structure This study also investigates the determinants of capital structure in Islamic and conventional banks. This is one of the first attempts to empirically examine the determinants of capital structure in Islamic and conventional banks in general and in MENA countries in particular. This study fills the gap in this important area of research and can provide a base for future research on capital structure in Islamic banks. This thesis use different models to test the capital structure and these are Panel data models (OLS, Fixed, and Random); Tobit and Dynamical model (Arellano-Bover Blundell-Bond), Structural Equation Modeling (SEM) and Generalised Regression Neural Networks (GRNN). The results suggest that the three methods used in this study lead to similar re- sults with a few exceptions in some countries. This thesis finds that the relation between leverage and the determinants of capital structure is different when using the market or the book leverage. It also finds that the determinants of capital struc- ture between the MENA countries are different. For example, profitability attribute relation with leverage follow the trade-off theory in some countries and follow the picking order theory in other countries. Also, liquidity is significant in all the countries in the sample and have a negative relation to leverage. In addition, tangibility is found to have a mixed results with some countries following the trade-off theory and other countries which follow the trade-off theory but overall it is a key determinant of capital structure. Additionally, the findings show that although that the majority of firms in the MENA countries don’t pay dividends the relation between the long term debt and leverage is negative in all the countries in the sample. The growth opportunities have a negative relation in Bahrain, Egypt, Jordan, Kuwait, Morocco, Palestine, Qatar and Tunisia but positive in rest of the countries. The cash flow attribute have a negative relation with leverage in all the countries in the sample except Saudi Arabia and Qatar when using the short and long term debt. Furthermore, the ownership variable is expected to have a negative relation when the ultimate owner is an institution. The results show that overall when there is an ultimate owner the leverage will have a negative relation. Suggesting that ultimate owners will force managers to keep a low debt in firms capital structure. This PhD also attempt to investigate the capital structure in banks within the MENA countries. A special focus is on the differences between the Islamic banks and conventional banks capital structure. First, the findings show that the banks follow the same determinants of capital structure as non-financial firms and that regulations are not the main determinant of capital structure in banks. Then, This study show that there is a difference in capital structure of Islamic banks in com- parison with conventional banks. The findings for the dividends variable show that Islamic banks do not follow the pecking order theory but conventional banks don’t. The results of the size variable show that when Islamic banks are large they use less debt in their capital structure. Growth variable show mixed results depending on the use of book or market leverage. Ownership structure show that when there is an ultimate owner leverage increase which is the reverse of the relation in the non-financial firms. The age variable is negative in relation to the book leverage and positive with the market leverage. Also, credit rating relation is different between the two banks, as it is positive with the conventional banks and negative with Islamic banks. Therefore, this study conclude that the main capital structure theories are applicable to MENA countries. Also indicate that Islamic banks have a different capital structure to conventional banks.

This thesis examines three aspects of capital structure of manufacturing, mining and retail firms listed on Johannesburg Securities Exchange (JSE). Firstly, it tests for the validity of the pecking order, the static trade-off and the dynamic trade-off theories in the context of South African manufacturing, mining and retail firms. The study used data from 42 manufacturing, 24 mining and 21 retail firms with complete data for four or more consecutive years during 2000-2010 (panel 1) to test the validity of these theories. The research hypotheses were formulated and tested using generalised least squares (GLS) random effects, maximum likelihood (ML) random effects, fixed effects, Prais-Winsten regression, Arellano and Bond, Blundell and Bond and the random effects Tobit models. Secondly, the thesis examines the impact of the firm’s key financial performance variables on firm leverage and speed of target adjustment. A panel of 49 manufacturing, 24 mining and 23 retail firms with complete data for two or more consecutive years during the period 2005-2010 (panel 2) was constructed and used in this test. The research hypotheses were formulated and tested using the same regression models used in panel 1. Lastly, the thesis examines the existence of the discounted value premium in manufacturing, mining and retail firms listed on the JSE. This study was done using panel of 47 manufacturing, 31 mining and 20 retail firms with complete data for four or more consecutive years during the period 2006-2010. A simple t-test was used to evaluate the significance of the sample’s discounted value premium. The study documents that firm growth rate, non-debt tax shields, financial distress, profitability, capital expenditure, asset tangibility, price earnings, ordinary share prices and changes in working capital were significant predictors of firm leverage. Dividend paid, capital expenditure, firm growth rate, profitability, cash flow from operations and economic value added were positively correlated to leverage. Asset tangibility, firm profitability, non-debt tax shields, financial distress, liquidity, price earnings, share price and retention rate were negatively correlated to leverage. Asset tangibility, financial distress, firm growth, non-debt tax shields, and long-term debt repaid were negatively correlated to changes in debt issued, whilst profitability, actual dividend paid, capital expenditure and changes in working capital were positively correlated. These results confirm the complementary nature of the trade-off and pecking order theories. Furthermore, the firms had positive and significant speeds of adjustment. In panel 1, the true speed of adjustment for the sample was 57.64% (0.81 years) for book-to-debt ratio (BDR) and 42.44% (1.25 years) for market-to-debt (MDR). The speed for manufacturing firms was 45.08% (1.16 years) for BDR and 44.59% (1.17 years) for MDR; for mining firms, 72.07% (0.54 years) for BDR and 56.45% (0.83 years) for MDR; and for retail firms, 28.42% (2.07 years) for BDR and 42.48% (1.25 years) for MDR. In panel 2, the true speed of adjustment for the sample was 64.20% for book-to-debt ratio (BDR) and 28.11% for market-to-debt ratio (MDR). The true speed for manufacturing firms was 34.42% for BDR and 30.56% for MDR; for mining firms, 69.59% for BDR and 45.77% for MDR; and for retail firms, 9.34% for BDR. These results confirm the validity of the dynamic trade-off theory. Finally, manufacturing, mining and retail firms had a positive discounted value premium. This ranged from 5.16% to 9.48% (on perpetual growth), with mining firms having the largest (9.48%), followed by manufacturing (8.54%) and retail firms (5.16%). Of the observations for the full sample, 92.23% showed a positive discounted value premium. This evidence on the speed of adjustment and discounted value premium suggests the existence of a target capital structure different from the theoretical optimal capital structure hypothesised by the static trade-off theory. / Thesis (PhD)--University of Pretoria, 2013. / Financial Management / unrestricted