Enterococcus faecalis V583 prophages: Dynamic interactions and contribution to bacterial pathogenic traits

Dissertation presented to obtain the Ph.D degree in Biology.

Estudo da expressão génica da Legionella pneumophila estirpe paris após co-cultura em Acanthamoeba castellanii

RESUMO: A Legionella é um bacilo Gram-negativo que replica dentro de protozoários como Acanthamoeba castellanii (A. castellanii) e no interior de macrófagos alveolares humanos, podendo resultar numa pneumonia grave. A Legionella em meio líquido tem um ciclo de vida bifásico, apresentando traços replicativos na fase exponencial e expressando factores transmissíveis na fase estacionária. Estudos recentes demonstraram que a Legionella precisa de assegurar um tempo preciso no seu ciclo de vida para efectuar com êxito a infecção das células hospedeiras. Muitos modelos de estudo foram desenvolvidos a fim de aumentar o conhecimento sobre o ciclo de vida intracelular e identificar os genes necessários para a modulação da célula hospedeira. Embora o conhecimento sobre a interacção bactéria-hospedeiro ainda seja limitado, parece que esta interacção gera um conjunto de características de virulência permitindo que a bactéria infecte células fagocíticas humanas e cause doença. O objectivo do presente projecto de investigação foi investigar e seleccionar genes críticos para a infecciosidade da Legionella pneumophila estirpe Paris (Lp Paris), desenhar e optimizar uma técnica de PCR em tempo real para o estudo da expressão génica e comparar o perfil de expressão da Lp Paris antes e depois da co-cultura em A. castellanii. Os resultados mostraram que oito dos 12 genes em estudo alteraram a sua expressão relativa após co-cultura em A. castellanii quando os ensaios foram realizados com culturas de Lp Paris na fase estacionária precoce (cinco foram induzidos e três reprimidos) Quando os ensaios foram realizados com culturas de Lp Paris na fase estacionária tardia 11 genes apresentaram repressão na sua expressão relativa. Analisando os resultados, concluímos que o perfil de expressão de Lp Paris foi modificado pela interacção com A. castellanii, no entanto essa mudança foi dependente da fase do seu ciclo de vida.-------ABSTRACT: Legionella is a pathogenic Gram-negative bacterium that replicates not only within aquatic protozoa like Acanthamoeba castellanii (A. castellanii), but also within human alveolar macrophages, which can result in a severe pneumonia. Legionella has a biphasic life cycle in broth, where exponential phase cultures display replicative traits and stationary bacteria express transmissive factors. Recent studies demonstrated that for successful infection of host cells, Legionella needs to ensure a precise timing of its life cycle. Many models of study were developed in order to learn about the intracellular life cycle and to identify the genes necessary for the host cell modulation. Although knowledge about the bacteria-host interaction is still limited, it appears that this interaction generate a pool of virulence traits, allowing the bacterium to infect human phagocytic cells and cause disease. The purpose of the present study was to investigate and select de critical genes for the infectivity of Legionella pneumophila strain Paris (Lp Paris), design and optimize a real time PCR technique for gene expression study and compare the expression profile of Lp Paris before and after co- culture of A. castellanii. The results show that eight of 12 genes in study changed its relative expression after coculture in A. castellanii when we performed the intracellular assays with early stationary phase Lp Paris cultures (five were induced and tree were repressed). When we performed the intracellular assays with late stationary phase Lp Paris cultures 11 genes showed a repressed relative expression. Analysing the results, we conclude that the expression profile of Lp Paris was modified by interaction with A. castellanii but this change was dependent of the timing of its life cycle.

Attitude change in arbitrarily large organizations

The alignment of collective goals and individual behavior has been extensively studied by economists under a principal-agent framework. Two main solutions have been presented: explicit incentive contracts and monitoring. These solutions correspond to changes in the objective situation faced by individuals. However, an extensive literature in social psychology provides evidence that behavior is influenced, not only by situational constraints, but also by attitudes. Therefore, an important aspect of organization is to choose the structures and procedures that best contribute to the dissemination of the desired attitudes throughout the organization. This paper studies how the initial configuration of attitudes and the size of the organization affect the optimal organizational structure and the timing of information flows when the objective is to align the members' attitudes. We identify and characterize three factors that affect the optimal organizational structures and procedures and the degree of alignment of attitudes: (1) clustering effects; (2) member cross-influence effects; and (3) leader cross-influence effects.

Innovation and environmental policy: Clean vs. dirty technical change

We study a two sector endogenous growth model with environmental quality with two goods and two factors of production, one clean and one dirty. Technological change creates clean or dirty innovations. We compare the laissez-faire equilibrium and the social optimum and study first- and second-best policies. Optimal policy encourages research toward clean technologies. In a second-best world, we claim that a portfolio that includes a tax on the polluting good combined with optimal innovation subsidy policies is less costly than increasing the price of the polluting good alone. Moreover, a discriminating innovation subsidy policy is preferable to a non-discriminating one.

Internal consultants as positive change agents

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Genetic parameters and mapping quantitative trait loci associated with tibia traits in broilers.

Abstract: Selection among broilers for performance traits is resulting in locomotion problems and bone disorders, once skeletal structure is not strong enough to support body weight in broilers with high growth rates. In this study, genetic parameters were estimated for body weight at 42 days of age (BW42), and tibia traits (length, width, and weight) in a population of broiler chickens. Quantitative trait loci (QTL) were identified for tibia traits to expand our knowledge of the genetic architecture of the broiler population. Genetic correlations ranged from 0.56 +/- 0.18 (between tibia length and BW42) to 0.89 +/- 0.06 (between tibia width and weight), suggesting that these traits are either controlled by pleiotropic genes or by genes that are in linkage disequilibrium. For QTL mapping, the genome was scanned with 127 microsatellites, representing a coverage of 2630 cM. Eight QTL were mapped on Gallus gallus chromosomes (GGA): GGA1, GGA4, GGA6, GGA13, and GGA24. The QTL regions for tibia length and weight were mapped on GGA1, between LEI0079 and MCW145 markers. The gene DACH1 is located in this region; this gene acts to form the apical ectodermal ridge, responsible for limb development. Body weight at 42 days of age was included in the model as a covariate for selection effect of bone traits. Two QTL were found for tibia weight on GGA2 and GGA4, and one for tibia width on GGA3. Information originating from these QTL will assist in the search for candidate genes for these bone traits in future studies.

Integrated approach to assess vulnerability of the Coastal Region of Bangladesh due to climate change

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

The impact of high involvement human resources practices on resistance to change: The mediator effect of commitment to change and the influence of ethical leadership

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Structural change in the ruhr region: problems, potentials and developments

Due to the decline of the heavy industries in the Ruhr region, the area has to reinvent itself. The orientation towards service industries proves to be a difficult task for the district and its population. This paper examines the challenges, problems and potentials of the Ruhr region against the backdrop of its economical history out of a sociological perspective. Thereby the economical situation and its outcome towards the population stand in the foreground of the paper.

Clearing the cloudy crystal balls: Hybrid modelling for energy and climate change mitigation scenarios – A case study for Portugal

Dissertação para obtenção do Grau de Doutor em Ambiente

Support in decision-making under uncertainty: a project risk assessment tool development and supplementary advances

A foremost dispute that persists on the contemporary world’s agenda is change. The on-going social/technological/economic changes create a competitive and challenging environment for companies to endure. To benefit from these changes, world economies partially depend on emerging Small and Medium Enterprises (SMEs) and their adaptability skills, and subsequently the development of an integrated capability to innovate has become the prime strategy for most of SMEs to subsist and grow. However, innovation and change are always somewhat bonded to an inherent risk development, which subsequently brings on the necessity of a revision of risk management approaches in innovative processes, whose importance SMEs tend to disregard. Additionally, little efforts have been made to improve and create empirical models, metrics and tools to assist SMEs managing latent risks in their innovative projects. This work seeks to present and discuss a solution to support SMEs in engaging on systematic risk management practices, which consists on an integrated risk assessment and response support web-based tool - Spotrisk® - designed for SMEs. On the other hand, an inherent subjectivity is linked with risk management and identification processes, due to uncertainty trait of its nature, for each individual perceives situations according to his own idiosyncrasy, which brings complications in normalizing risk profiles and procedures. This essay aims to bring insights concerning the support in decision-making processes under uncertainty, by addressing issues related with the risk behavior character among individuals. To address such issues, subjects of neuroscience or psychology are explored and models to identify such character are proposed, as well as models to improve presented tool. This work attempts to go beyond the restrictive aim of endeavoring on technical improvement dissertation, and in embraces an exploratory conceptualization concerning micro, small and medium businesses’ traits regarding risk characters and project risk assessment tools.

How can packaging change children's eating habits from un-healthy food towards healthier options?

Field Lab: Children consumer behaviour

Avaliação de mudanças na personalidade no processo psicoterapêutico : Estudo de caso

Dissertação de Mestrado apresentada ao ISPA - Instituto Universitário

Generalized Dasymetric Mapping Algorithm for Accessing Land-Use Change

Contém resumo