Admission Conditions and Graduates' Employability

We evaluate the information content of admission conditions for study programs’ quality by investigating its relationship with graduates’ employability. We find that study programs with larger numeri clausi are associated with a higher probability of finding a job. Additionally, compulsory admission exams seem to be informative about study programs’ quality. Namely, study programs requiring the Math exam appear to be linked with lower unemployment propensity. Cardoso et al. (2008), however, found that those programs face lower demand when compared to other studies. These paradoxical results suggest that students’ choices may be based on insufficient information on returns to higher education investment. That information failure indicates that a Government intervention may be due.higher education, unemployment propensity, fractional models

Admission conditions and graduates' employability

We evaluate the information content of admission conditions for study programs’ quality by investigating its relationship with graduates’ employability. We find that study programs with larger numeri clausi are associated with a higher probability of finding a job. Additionally, compulsory admission exams seem to be informative about study programs’ quality. Namely, study programs requiring the Math exam appear to be linked with lower unemployment propensity. Cardoso et al. (2008), however, found that those programs face lower demand when compared to other studies. These paradoxical results suggest that students’ choices may be based on insufficient information on returns to higher education investment. That information failure indicates that a Government intervention may be due.Higher education; unemployment propensity; fractional models

Minimum Wage, Fringe Benefits, Overtime Payments and the Gender Wage Gap

Using linked employer-employee data for Portugal, we explore an amendment to the minimum wage law which increased from 75% to 100% of the full minimum wage applied to employees younger than 18. Our results show a widening of the gender wage gap following the amendment: the wage gap for minors increased 2.7 percentage points more than for other groups. This change was mainly determined by a redistribution of fringe benefits and overtime payments. We discuss three possible sources of redistribution: (i) a change in the skill composition of the working males and females after the increase in the minimum wage, (ii) industrial differences in response to the changes in the wage floor, and (iii) discrimination. Estimations support the second channel as the main contributing factor, while possible discrimination effects cannot be eliminated.minimum wage, overtime payments, fringe benefits, gender wage gap, minors

Demand for higher education programs: the impact of the Bologna process

The Bologna process aims at creating a European Higher Education Area where intercountry mobility of students and sta?, as well as workers holding a degree, is facilitated. While several aspects of the process deserve wide public support, the reduction of the length of the first cycle of studies to three years, in several continental European countries where it used to last for four or five years, is less consensual. The paper checks the extent of public confidence in the restructuring of higher education currently underway, by looking at its implications on the demand for academic programs. It exploits the fact that some programs have restructured under the Bologna process and others have not, in Portugal. Precise quantification of the demand for each academic program is facilitated by the rules of access to higher education, in a nation-wide competition, where candidates must list up to six preferences of institution and program. We use regression analysis applied to count data, estimating negative binomial models. Results indicate that the programs that restructured to follow the Bologna principles were subject to higher demand than comparable programs that did not restructure, as if Bologna were understood as a quality stamp. This positive impact was reinforced if the institution was a leader, i.e. the single one in the country that restructured the program. Still an additional increase in demand was experienced by large programs that restructured to offer an integrated master degree, thus conforming to Bologna principles while not reducing the program duration.education policy; European Higher Education Area; economic, social and cultural integration; count data.

Demand for Higher Education Programs: The Impact of the Bologna Process

The Bologna process aims at creating a European Higher Education Area where inter-country mobility of students and staff, as well as workers holding a degree, is facilitated. While several aspects of the process deserve wide public support, the reduction of the length of the first cycle of studies to three years, in several continental European countries where it used to last for four or five years, is less consensual. The paper checks the extent of public confidence in the restructuring of higher education currently underway, by looking at its implications on the demand for academic programs in Portugal. Precise quantification of the demand for each academic program is facilitated by the rules of access to higher education, in a nation-wide competition, where candidates must list up to six preferences of institution and program. We use regression analysis applied to count data, estimating negative binomial models. Results indicate that the programs that restructured to follow the Bologna principles were subject to higher demand than comparable programs that did not restructure, as if Bologna were understood as a quality stamp. This positive impact was reinforced if the institution was a leader, i.e. the single one in the country that restructured that program. Still an additional increase in demand was experienced by large programs that restructured to offer an integrated master degree, thus conforming to Bologna principles while not reducing the program duration.education policy, European Higher Education Area, economic, social and cultural integration, count data

Regulation and marketisation in the Portuguese higher education system

This paper builds on the ongoing discussion on regulation and marketisation of higher education. It aims at investigating the higher education market (des)equilibrium. Teixeira, Rosa and Amaral (2004) have analysed the presence/absence of market mechanisms in the Portuguese higher education sector. We go a step further in quantifying the (mis)mactching between demand and supply, by suggesting and computing a set of indicators, which provide the starting point for a ranking-based analysis. Institutional rankings are central to overcome the problem of absence of information on quality in higher education systems, which is a basic requirement for a real higher education market.higher education market, demand, supply

In vivo metabolic pathway analysis of Enterococcus faecalis for uncovering key pathogenicity factors

Tese doutoramento em "Chemical and Biological Engineering"In spite of the increasing progress in the fight against prokaryotic pathogens, numerous bacteria play a significant concern for human health. Most of the current knowledge has been on isolated biochemical reactions or pathways exposed to a potential stress likely to be encountered in the host. Enterococci are equipped with a variety of intrinsic (i.e., naturally occurring) antibiotic resistances, but are also capable of acquiring new resistance genes and / or mutations. The present thesis aimed to gather knowledge on the pathogenic bacterium Enterocccus faecalis using genomics and post-genomics technologies and continuous culture techniques to study the behaviour of the complete biological system (bacterial cell) in vivo under different environmental perturbations. The knowledge obtained, together with the annotated genome sequence of E. faecalis was used to develop the first genome-scale mathematical model that will hopefully serve as a valuable tool to explore the metabolism of the organism and help unravel hidden metabolic pathways essential for bacterial growth and survival. The experiments carried out allowed testing two Enterococcus faecalis strains against the oxidative stress imposed in the form of oxygen and hydrogen peroxide while varying the dilution rate. The first line defence was observed to be a shift in the glycolytic pathway, the pentose phosphate pathway and glutathione production while the downstream response was imposed on the fatty acid metabolism and demethylmenaquinone biosynthesis. The first genome-scale reconstruction of this organism involved a pipeline of extremely laborious tasks that comprised the assembly of all the metabolic reactions encoded on the annotated genome sequence, the manual curation of the information collected and the refinement of the network to allow the model to simulate and further test the capabilities of the network. This model aimed to predict in silico, the capabilities expressed by this organism in vivo. Indeed, the simulations carried out were able to accurately predict the qualitative behaviour of this organism evidenced by the metabolic distribution shift observed in the simulations of homolactic and heterolactic metabolism or under aerobic and anaerobic environment.Apesar do crescente progresso na luta contra agentes patogénicos, são inúmeras as bactérias que desempenham um papel significativo na saúde humana. O atual conhecimento tem sido obtido através da análise de reações bioquímicas isoladas ou das vias expostas a uma condição de estresse passível de ser encontrada no hospedeiro. O género enterococos está intrinsecamente equipado com uma grande variedade de resistências a antibióticos, mas é igualmente capaz de adquirir novos genes de resistência e / ou mutações A presente tese teve como objetivo explorar o metabolismo do patogénico Enterococcus faecalis, utilizando para o efeito tecnologias na área da genómica e pós-genómica acopladas a técnicas de cultura contínua para estudar o comportamento do sistema biológico completo (célula bacteriana) in vivo sujeito a diferentes perturbações. O conhecimento obtido, juntamente com o recurso à sequência anotada do genoma da E. faecalis permitiu desenvolver o primeiro modelo à escala genómica que pretende ser uma ferramenta valiosa para explorar o metabolismo do organismo e ajudar a revelar novas vias metabólicas essenciais para o crescimento bacteriano e a sua sobrevivência. As experiências levadas a cabo com duas estirpes de Enterococcus faecalis analisaram a resposta metabólica ao estresse oxidativo, aplicada sob a forma de oxigénio e de peróxido de hidrogénio conjuntamente com uma variação da taxa de diluição. Observou-se que a primeira linha de defesa em resposta ao estresse foi uma mudança na via glicolítica, a via das pentoses fosfato e da produção de glutationa, enquanto a resposta a jusante foi imposta sobre o metabolismo dos ácidos gordos e biossíntese de demetilmenaquinona. A reconstrução do primeiro modelo à escala genómica deste organismo envolveu tarefas laboriosas e complexas num processo iterativo. Todas as reações metabólicas codificadas na sequência genómica foram recolhidas, seguida da sua curação manual e posterior refinamento da rede para obter um modelo simulável capaz de testar as capacidades da rede. Este modelo pretende prever in silico as capacidades expressas in vivo por este organismo. As simulações realizadas foram capazes de prever com precisão o comportamento qualitativo deste organismo evidenciando uma distribuição metabólica característica de um metabolismo homolático e heterolático ou em ambiente aeróbio e anaeróbio

Population genetics of C. Maenas : oceanography and larval dispersal

Doutoramento em BiologiaDecifrar a complexa interacção entre os ciclos de vida de espécies marinhas e a oceanografia revela-se fundamental para a compreensão do fluxo genético e da conectividade no meio marinho. Nas espécies marinhas com desenvolvimento indirecto o fluxo de genes entre populações depende da distância que separa as populações, bem como da interacção entre a duração do desenvolvimento larvar, do comportamento das larvas e dos padrões de circulação oceânica. A conectividade larvar influencia uma variedade de processos como a dinâmica de stocks e de populações, a distribuição e limites geográficos das espécies, a estrutura genética das populações e a dispersão de espécies invasivas e reveste-se consequentemente de uma importância fundamental na identificação das unidades populacionais evolucionariamente relevantes e para a gestão e conservação marinhas. Os marcadores genéticos e os Modelos Individuais Acoplados a Modelos Físico-Biológicos (“ICPBMs”) são actualmente ferramentas fundamentais para o estudo dos padrões de dispersão larvar e para avaliar o nível de conectividade populacional. A presente tese respeita à avaliação das escalas espaciais de conectividade de populações de uma espécie costeira, o caranguejo Carcinus maenas, e utiliza conjuntamente informação de marcadores genéticos, análise de séries temporais de fornecimento de larvas e um modelo numérico de circulação oceânica. O primeiro capítulo introduz a temática da conectividade em espécies marinhas e inclui algumas referências aos métodos moleculares, analíticos e de modelação seguidos ao longo da tese. Através da utilização de múltiplas ferramentas – avaliação da estrutura genética geográfica de C. maenas na sua distribuição nativa com recurso a marcadores de DNA (microssatélites) (Capítulo 2), avaliação da estrutura genética temporal das larvas que formam os eventos de fornecimento larvar à Ria de Aveiro, NW Portugal (Capítulo 3), descrição da variabilidade inter-anual do fornecimento larvar à Ria de Aveiro, NW Portugal (Capítulo 4) e validação de um modelo ICPBM que descreve os padrões observados de fornecimento (Capítulo 5) – esta tese espera poder contribuir para uma melhor compreensão dos mecanismos que regulam o fluxo de genes e a conectividade entre populações de organismos marinhos. No Capítulo 6 são apresentadas as principais conclusões da investigação. A análise genética com recurso a microssatélites indicou que as populações de C. maenas são geneticamente homogéneas ao longo de várias centenas de km, dentro da distribuição nativa da espécie. Paralelamente, não foram encontrados indícios da existência de reprodução por “sweepstakes” em C. maenas de populações da costa oeste da Península Ibérica, visto que não se obtiveram diferenças genéticas significativas entre os eventos larvares. Também não se encontrou qualquer estrutura familiar entre as larvas que formam cada episódio de fornecimento, e não houve nenhuma redução significativa da variabilidade genética das larvas quando comparada com a de caranguejos adultos. A análise de séries temporais de suprimento de larvas na Ria de Aveiro em cinco anos estudados indica que este é um fenómeno episódico e variável, sendo os maiores episódios de fornecimento coincidentes com as marés vivas e acentuados por fortes ventos de sul. O modelo ICPBM foi validado com sucesso e parece fornecer uma estimativa realística das escalas espaciais e temporais de dispersão larvar, de acordo com as observações da estrutura genética e da ausência de reprodução por “sweepstake” em C. maenas da costa oeste da Península IbéricaUnravelling the interactions between life-history strategies and oceanographic processes is central to the understanding of gene flow and connectivity in the marine environment. In particular, for marine species with indirect development gene flow between populations depends on the distance separating the populations and on the interaction between duration of the larval phase, larval behaviour and current patterns. Larval connectivity affects many processes, including stock and population dynamics, species ranges, population genetic structure, and the spread of invasive species and is therefore an important consideration to identify evolutionary relevant population unit and for marine management and conservation efforts. Genetic markers and Individual-based Coupled Physical-Biological Models (ICPBMs) are two of the tools currently available for tracking dispersal pathways of larvae and to assess the degree of population connectivity. The present thesis concerns the spatial and temporal scale assessment of population connectivity of a coastal marine species, the shore crab Carcinus maenas, making use of genetic markers, time series larval supply analysis and an oceanographic numerical model. Chapter 1 introduces the thematic of marine species connectivity, including a brief reference to the molecular, analytical and modelling methods followed during the study. Making use of an interdisciplinary approach – assessment of genetic geographical structure with microsatellite markers within C. maenas native range (Chapter 2), assessment of temporal genetic structure of larvae forming each supply event to the Ria de Aveiro, NW Portugal (Chapter 3), description of interannual variability of larval supply to the Ria de Aveiro, NW Portugal (Chapter 4) and validation of an ICPBM to describe the observed time series of supply (Chapter 5) – the aims of this thesis is to contribute to our understanding of the mechanisms regulating gene flow and connectivity among marine populations. Finally, in Chapter 6 the main results and conclusions achieved are presented. Microsatellites analysis indicated that C. maenas populations were genetically similar across hundreds of km, within the species native range. Additionally, there was no evidence of sweepstakes reproduction in C. maenas from western Iberian coast populations since there were no significant differences amongst larval events. Among larvae in each episode, no genetic relatedness was found, and larvae did not present reduced genetic variability when compared to adult crabs. On a long time scale, larval supply to the Ria de Aveiro was episodic and variable throughout five different studied years, with highest supply numbers generally occurring around spring tides and enhanced by strong southerly winds. The ICPBM was successfully validated and appears to provide a realistic estimate of the observed spatial and temporal scales of the larval dispersal, consistent with the observations on genetic structure and lack of sweepstake reproduction in C. maenas from western Iberian coast

Assentamento, mortalidade e crescimento de larvas e juvenis de Chthamalus montagui na costa noroeste de Portugal

Mestrado em Ciências das Zonas CosteirasA maioria dos invertebrados marinhos bentónicos possui um ciclo de vida complexo que inclui uma fase larvar planctónica separada da fase juvenil e adulta, geralmente sedentárias, que ocupam habitats diferentes. Em muitos casos, as larvas passam entre vários dias a várias semanas na coluna de água, onde enfrentam o problema de regressar para junto de habitats apropriados para assentar e aí completar a metamorfose com sucesso. É actualmente bem reconhecida a importância que a variação espacial e temporal dos processos de assentamento e recrutamento dos organismos pode ter na estrutura e dinâmica das populações e comunidades bentónicas. Esta variação é o resultado da variação observada nos processos oceanográficos costeiros responsáveis pelo transporte das larvas, e das interacções entre o comportamento larvar, a hidrodinâmica local e as características do habitat bentónico. Também os processos de pósassentamento como a predação, competição e stress físico ditam muitas vezes os padrões observados na distribuição e abundância dos organismos adultos. As cracas, como espécie chave na zona entre marés, representam um excelente invertebrado marinho onde testar taxas de mortalidade e crescimento. A abundância e distribuição de cypris e juvenis da craca Chthamalus montagui foi monitorizada em duas praias da costa noroeste de Portugal, durante o verão de 2003. Amostragens diárias a vários níveis verticais da praia permitiram a determinação da mortalidade pós-assentamento após períodos de 7, 15 e 28 dias. A medição do diâmetro opercular dos indivíduos permitiu o cálculo das taxas de crescimento. A distribuição vertical do assentamento não reflectiu a distribuição dos organismos adultos. Elevadas taxas de assentamento foram encontradas no nível mais inferior da praia, uma zona claramente dominada por mexilhão, onde poucos C. montagui sobrevivem até ao estado adulto. O nível médio é dominado por C. montagui, apesar do assentamento ter sido menos intenso. Este estudo também reporta taxas de mortalidade cujos valores se situam entre os 0.045 ind d-1 e os 0.691 ind d-1; a taxa de mortalidade aumenta do nível inferior para o nível superior da praia e estas diferenças são significativas. A dissecação é provavelmente a principal causa de mortalidade e influencia a densidade da população ao aumentar a mortalidade nos níveis da praia superiores. Mais tarde, o crescimento dos mexilhões sobre as cracas parece ser a maior fonte de mortalidade pósassentamento no nível inferior da zona entre marés. Um efeito significativo da idade no tamanho dos juvenis foi detectado. Adicionalmente, apesar de não terem sido encontradas diferenças significativas, em termos estatísticos, nas taxas de crescimento dos juvenis entre os níveis da praia, as taxas de crescimento na zona inferior, que corresponde à cintura de mexilhão, foram duas vezes superiores às medidas no nível imediatamente acima. Uma combinação de factores é responsável pelos padrões de recrutamento observados nas praias rochosas. No entanto, os processos de pósassentamento incluindo a competição e o stress físico, mais do que simplesmente o assentamento larvar, são sugeridos como os factores mais importantes na determinação dos padrões verticais de abundância característicos de C. montagui nestas praias.The majority of marine benthic invertebrates exhibit a complex life cycle that includes separate planktonic larval, and a benthic juvenile and adult phases, which occupy different habitats. In many cases larvae last for several days to several weeks in the water column, facing the problem of returning to appropriate habitats for settlement and successful metamorphosis. It is presently well recognized the importance of the spatial and temporal variation in settlement and recruitment on the structure and dynamics of benthic populations and communities. This variation is a result of the variation observed in the coastal oceanographic processes responsible for larval transport, and of interactions among larval behaviour, local hydrodynamic conditions and the characteristics of the benthic habitat. Post-settlement processes such as predation, competition and physical stress are often critical in determining the patterns of adult abundance and distribution. Barnacles as key-species in the intertidal environment are an especially interesting marine invertebrate on which to test mortality and growth rates. The abundance and distribution of cyprid larvae and juveniles of the barnacle Chthamalus montagui were monitored on two shores on the northwest coast of Portugal, during the summer of 2003. Daily samplings over various vertical shore levels allowed the determination of post-settlement mortalities after 7, 15 and 28-days periods. Measuring opercular diameters of individuals allowed the calculation of juvenile growth rates. Vertical distribution of settlement did not reflect distribution of adults. High settlement rates were measured lower in the shore, a zone clearly dominated by mussels, where few C. montagui survive to adult stage. Mid-shore was dominated by C. montagui, although settlement was less intense. This study also report mortality rates ranging from 0.045 ind d-1 to 0.691 ind d-1 and patterns of mortality significantly different between shore levels, with mortality rate increasing from low to high intertidal. Desiccation is probably the main cause of mortality and influences population densities by increasing mortality on the upper shore. Later, overgrowth of barnacles by mussels appears to be a major source of post-settlement mortality in the low intertidal zone. A significant effect of age on size of juveniles was also detected. In addition, although differences in juvenile growth rates among shore levels were not significant in the strict statistical sense, growth rates in the low intertidal mussel zone were twice as high as those measured on the mid-shore. A combination of factors is responsible for the pattern of recruitment observed on rocky shores. However, post-settlement processes including competition and physical stress, rather than merely larval settlement, are suggested to be more significant factors in determining the characteristic vertical patterns of C. montagui abundance in these shores

Metabolic network reconstruction of the central carbon metabolism of Enterococcus faecalis

The profound advance in experimental high throughput techniques (generally referred to as “omics techniques”) has enabled the analysis of a large number of components within a living cell. The vast amount of data obtained from the different “omics” (genomics, proteomics, fluxomics, metabolomics, transcriptomics) demands the use of bioinformatics tools. These methods comprise the development of comparative tools and maintenance of databases for the analysis of genomics data, in addition to the construction of models for the analysis and integration of data in a system-wide approach. Enterococcus faecalis is a Gram-positive bacterium that is getting more attention due to its “two-face” behavior. This natural inhabitant of the mammalian gastrointestinal tract is also an opportunist pathogen responsible for urinary tract infections, nosocomial infections, bacteremia and infective endocarditis. Besides, its intrinsic physiological properties such as inherent antibiotic resistance and exceptional ability to adapt to harsh conditions provide this organism with an enormous advantage in the infection processes. Here, we propose to reconstruct the genome scale metabolic network of the central carbon metabolism of Enterococcus faecalis using genome sequencing information available on different databases as well as proteomics and metabolomics data. The first metabolic model generated for this bacterium will allow correlating metabolite levels and fluxes which enables identification of key control points in its metabolism. As it has been previously shown for other organisms, the metabolic network reconstruction may serve as a valuable tool to predict the phenotypic behaviour under various genetic and environmental conditions