Do Low Cost Carriers Have Different Corporate Governance Models?

In this paper, we investigate whether different business models in the same industry (passenger air transportation) lead to different corporate governance models. We found that low cost carriers (LCCs) organise their boards differently from full service carriers (FSCs), in order to achieve lower costs and the faster decision-making process that is required by their business model. We also found that LCCs and FSCs solve their potential agency cost problems differently. FSCs have more board committees in order to monitor management, and LCSs have a closer coincidence of interests between shareholders and management.corporate governance, low cost carriers

Does market concentration of downstream buyers squeeze upstream suppliers’ market power?

Using a theoretical model, we examine both the relationship between a downstream dominant firm’s market share and an upstream monopoly’s Lerner index and the relationship between upstream and downstream price elasticities of demand, in a regulated industry context. We undertake an empirical study that confirms our theoretical predictions, namely that the market share of a leader downstream firm is significant in explaining the upstream producers’ Lerner indexes. Also in accordance with the results of the theoretical model, the Lerner index is negatively influenced by the competition that suppliers face and by the level of economies of density, amongst other variables.vertical relations, buyers’ market power

Angola e China: numa encruzilhada?

Na continuação da nossa série de analises sobre o futuro das relações Sino-Africanas, Ana Cristina Alves da LSE e SAIIA , relata-nos o ponto da vista de Angola

Africa and China: At a crossroads in Angola

As we continue our series looking at the future of Sino-Africa relations, LSE’s Ana Cristina Alves gives us the view from Angola

Existence and concentration of ground state solutions for a critical nonlocal Schr\"odinger equation in R2\R^2

We study the following singularly perturbed nonlocal Schr\"{o}dinger equation -\vr^2\Delta u +V(x)u =\vr^{\mu-2}\Big[\frac{1}{|x|^{\mu}}\ast F(u)\Big]f(u) \quad \mbox{in} \quad \R^2, where $V(x)$ is a continuous real function on $\R^2$, $F(s)$ is the primitive of $f(s)$, $0<\mu<2$ and \vr is a positive parameter. Assuming that the nonlinearity $f(s)$ has critical exponential growth in the sense of Trudinger-Moser, we establish the existence and concentration of solutions by variational methods.Comment: 3

IN-SITU XRD STUDIES OF THERMAL STABILITY OF PURE SILICA AND Ti-MCM-41 MATERIALS

In this work we present a study on the thermal stability of siliceous and titanium containing ordered mesoporous materials with MCM-41 structure, prepared by direct synthesis at ambient temperature and pressure, as previously described [1]. Grades with different pore diameter and Si/Ti molar ratios were analyzed, in the form of compacted powder, to assess its influence on the order-disorder transition temperature

China’s oil diplomacy: comparing Chinese economic statecraft in Angola and Brazil

This thesis aims to investigate the reasons for the variation in China’s oil diplomacy performance in Africa and South America in the period 2000-2010. Lacking sound experience in pursuing oil security overseas and enjoying strong financial muscle, China’s oil diplomacy is largely rooted in the extension of soft loans for infrastructure to oil-rich countries in exchange for steady oil supply and favoured access to oil acreage. Taking Angola and Brazil as case studies this thesis argues that differences in the institutional structure of the oil industry in each country, determined different outcomes regarding Beijing’s oil security goals. This thesis has found that although this template fitted well with the more centralised institutional environment in Angola, it was highly unsuitable for the more liberal and regulated Brazil setting. Furthermore, the advent of the recent global economic crisis (2008-2009) caused China to adjust its approach to the institutional particulars of Brazil becoming more efficient in that country regarding its oil security goals. Building on foreign policy analysis tools and concepts, an empirical analysis of the interplay between Chinese infrastructure-for-oil loans (hereby regarded as positive economic statecraft) and the institutional structure it met in each country, is presented. Through the case studies, this thesis aims to uncover to what extent the institutional context constrained Chinese oil diplomacy efficiency in Brazil for most of the past decade, and how innovation has surfaced in the context of the global financial crisis. This analysis thus gives interesting insights not only into the dynamics of China’s oil diplomacy in Africa and South America, but also into Chinese economic statecraft in general and how constraints that surface at the implementation level feedback into foreign policy formulation

Triggering secondary metabolite biosynthesis: exploring the effects of ionic liquids in fungal metabolism

Filamentous fungi are able to synthesise an array of small molecules (secondary metabolites), which are usually not essential for fungal growth but confer competitiveness. As a consequence, numerous secondary metabolites remain cryptic at the artificial conditions of cultivation in a research laboratory. Even in Aspergillus nidulans, one of the most well studied fungi, numerous metabolites remain unseen. Several strategies have been used to solve this knowledge gap, some of which require prior knowledge of genomic sequences, relying on manipulation of targeted genes encoding components of either secondary metabolism or regulatory pathways. Other approaches may be applied also in less well characterised strains, such as cultivation with other species/organisms or modification of the growth media composition. (...

Role of apoptotic regulators in the protective effect of acetic acid against ethanol - induced cell death in Saccharomyces cerevisiae

Dissertação de mestrado em Bioquímica AplicadaEthanol is a well-know end product of alcoholic fermentation carried by Saccharomyces cerevisiae. At relatively low concentrations it is an inhibitor of yeast growth, while, high ethanol concentrations reduces cell viability (Birch and Walker, 2000). During fermentation, acetic acid produced by yeast metabolism may accumulate in growth medium and enhance ethanol toxicity (Gibson et al., 2007). By contrast, studies conducted in our laboratory have shown that S. cerevisiae cells exposed simultaneously to toxic concentrations of ethanol and low concentrations of acetic acid displayed a higher survival than cells treated only with ethanol (Vieira et al., unpublished results). Later, Trindade showed that Hog1p and Fps1p, involved in acetic acid resistance, do not have a role in the protective effect of acetic acid seen by Vieira (Trindade, 2009). Subsequently, it was also shown that the osmolyte trehalose, the heat shock protein Hsp12p, the MAP kinase Slt2/MPK1 and functional mitochondria play a role in the protection by the undissociated form of acetic acid against ethanol induced cytotoxicity (Afonso, 2011). With the present master thesis we intended to further understand how acetic acid protects against ethanol-induced cytotoxicity, determining the role of known apoptotic regulators in this protection. We also intended to characterize the death of cells exposed to toxic concentrations of ethanol since this knowledge is important to dissect the role of acetic acid in its inhibition. This study showed that the deletion in CYC3 or ATP2, ATP10 and NUC1 abolish and decrease, respectively, the protection of acetic acid against loss of cell viability, loss of plasma membrane integrity and the accumulation of superoxide anion, induced by ethanol. Death induced by ethanol was associated with typical markers of apoptosis but also of necrosis. In particular caspase activation and exposure of phosphatidylserine was detected mainly in cells with compromised plasma membrane, but also HMGB1/Nhp6A translocates from the nucleus to the cytosol in response to ethanol. Moreover, the absence of known apoptotic regulatory proteins abrogate (atp2Δ, atp10Δ, cyc3Δ, por1Δ, cpr3Δ and yca1Δ mutants), exacerbate (aif1Δ, nuc1Δ, and cyc1Δcyc7Δ mutants) or have no effect (pep4Δ mutant) in ethanol induced cell death. Altogether the results obtained with the mutants phenotypes and the characterization of cell death markers indicate that ethanol triggers a regulated cell death process that shares features typical of both apoptosis and necrosis. Whether the necrotic features reflect a programmed necrosis or a secondary necrosis of apoptotic cells committed to death in response to ethanol, requires further studies.O etanol é um produto final bem conhecido da fermentação alcoólica conduzida por Saccharomyces cerevisiae . Em concentrações relativamente baixas é um inibidor do crescimento da levedura, enquanto em concentrações elevadas induz perda da viabilidade celular (Birch e Walker, 2000). Durante a fermentação, o ácido acético produzido pelo metabolismo da levedura pode acumular-se no meio extracelular e aumentar a toxicidade de etanol (Gibson et al., 2007). Por outro lado, estudos realizados no nosso laboratório mostraram que células de S. cerevisiae simultaneamente expostas a concentrações tóxicas de etanol e baixas concentrações de ácido acético exibiam uma maior sobrevivência do que aquelas tratadas apenas com etanol. (Vieira et. al., resultados não publicados). Mais tarde, Trindade mostrou que as proteínas Hog1p e Fps1p, envolvidas na resistência ao ácido acético, não apresentam um papel no efeito protetor do ácido acético observado por Vieira (Trindade, 2009). Posteriormente, mostrou-se que o osmólito trealose, a proteína de choque térmico Hsp12p, a MAP quinase Slt2/MPK1 e mitocôndrias funcionais têm um papel na proteção da forma não dissociada do ácido acético contra citotoxicidade induzida por etanol (Afonso, 2011). Com a presente dissertação de mestrado pretendeu-se compreender melhor como o ácido acético protege contra a citotoxicidade induzida por etanol, determinando o papel de reguladores conhecidos da apoptose nesta proteção. Também se pretendeu caracterizar a morte de células expostas a concentrações tóxicas de etanol uma vez que este conhecimento é importante para dissecar o papel do ácido acético, na sua inibição. Este estudo mostrou que a ausência dos genes CYC3 ou ATP2, ATP10 e NUC1 elimina e diminui, respetivamente, a proteção do ácido acético contra a perda induzida pelo etanol da viabilidade celular, da integridade da membrana plasmática e da acumulação de anião superóxido. A morte induzida pelo etanol foi acompanhada de marcadores celulares típicos de apoptose, mas também de necrose. Em particular foi detetada ativação de caspases e exposição de fosfatidilserina principalmente em células com a membrana plasmática comprometida, mas também a translocação do HMGB1/Nhp6A do núcleo para o citosol em resposta ao etanol. Adicionalmente, a ausência de reguladores apoptóticos reduziram (nos mutantes atp2Δ, atp10Δ, cyc3Δ, por1Δ, cpr3Δ e yca1Δ), potenciaram (nos mutantes aif1Δ, nuc1Δ, e cyc1Δcyc7Δ ) ou não afetaram a sobrevivência celular (no mutante pep4Δ) em resposta ao etanol. Os resultados respeitantes aos fenótipos dos mutantes estudados e à caracterização dos marcadores de morte celular indicam que o etanol induz uma morte regulada que partilha características típicas de apoptose e necrose. Se as características de necrose refletem uma necrose programada ou uma necrose secundária de células que desencadearam um processo de morte apoptótico, requer mais estudos no futuro.Fundação para a Ciência e a Tecnologia (FCT) - Projeto PEst- C/BIA/UI4050/2011, FCOMP-01-0124-FEDER-007047 e PTDC/AGR- ALI/102608/2008.FEDER através do POFC–COMPET

Estratégias de aprendizagem da produção oral em língua estrangeira : um estudo de caso no 2.º ciclo do ensino básico

Dissertação de Mestrado em Educação - Área de Especialização em Supervisão Pedagógica em Ensino das Línguas EstrangeirasO estudo aqui apresentado tem por tema as estratégias de aprendizagem que os alunos mobilizam em actividades didácticas de produção oral em LE (Inglês). Trata-se de um estudo de caso de natureza interpretativa, realizado numa turma do 2º Ciclo do Ensino Básico (5º ano de escolaridade), no qual a professora assume o estatuto de investigadora participante. A competência da oralidade desempenha um papel importante na formação integral do aluno a par de outras competências de comunicação (ouvir, ler e escrever), importância essa que nem sempre lhe é atribuída nas aulas e manuais do 2.º Ciclo de Ensino Básico, sendo ainda escasso o conhecimento dos professores acerca dos processos de produção oral dos seus alunos. Através do desenho e implementação de actividades didácticas com enfoque na produção oral em interacção, procurou-se identificar as estratégias de aprendizagem que os alunos mobilizam nessas actividades, no sentido de melhorar a prática e alargar a compreensão sobre processos de aprendizagem. Foi também nossa intenção contribuir para o desenvolvimento de uma estratégia de auto-supervisão em contexto pedagógico, dando a conhecer uma hipótese de trabalho sobre a promoção e regulação da competência da oralidade. A recolha de informação teve como suporte o preenchimento de questionários sobre percepções, atitudes e expectativas dos alunos face à aprendizagem da LE, com enfoque na produção oral em interacção, um questionário de regulação de estratégias de aprendizagem da produção oral em interacção e entrevistas de reflexão sobre o uso dessas estratégias. A análise da informação recolhida permite constatar que os alunos manifestam atitudes bastante favoráveis à aprendizagem da LE. As estratégias de produção oral a que dizem recorrer nas actividades de produção oral são sobretudo de tipo indirecto, o que sugere a necessidade de trabalhar mais as estratégias directas em contexto pedagógico. O estudo parece validar uma abordagem de auto-supervisão que pode apoiar os professores na compreensão dos processos de aprendizagem dos seus alunos e promover o desenvolvimento de capacidades de auto-regulação desses processos.The present study is focused on the learning strategies of oral production that students use in FL (English) speaking activities in the classroom. It is an interpretative case study conducted in a class of 5th grade students, where the teacher was a participant researcher. Although oral production plays an important role in the integral development of students along with other language skills (listening, reading and writing), that is not always evident in foreign language lessons and course books for beginners, and teachers’ knowledge of students’ learning processes within oral production is often scarce. Through the design and implementation of activities focused on oral production, we tried to identify the learning strategies that students use in speaking activities in order to improve practice and expand our understanding of their learning processes. At the same time, it was our intention to develop a self-supervision strategy that represents a working hypothesis to promote and regulate oral production processes in pedagogical settings. Data collection was based on student questionnaires about perceptions, attitudes and expectations towards foreign language learning, with a particular focus on oral production within interactive activities, a student self-regulation questionnaire on learning strategies of oral production, and student oral reflections in interviews on the use of those strategies. Data analysis shows that the students hold positive attitudes towards foreign language learning. As regards oral production, they refer mostly to the use of indirect strategies, which suggests the need to explore further the use of direct strategies in pedagogical contexts. The study seems to validate a self-supervision approach that may both enhance teachers’ understanding of students’ learning processes and promote the development students’ self-regulation abilities