The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. http://run.unl.pt:80 2013-05-24T00:08:55Z 2013-05-24T00:08:55Z Sampaio, Mafalda http://hdl.handle.net/10362/9687 2013-05-23T15:31:45Z 2012-01-01T00:00:00Z

Title: Three essays in risky behaviors Authors: Sampaio, Mafalda Abstract: This dissertation consists of three essays on the relationship between risky behaviors and social environment, including the strategic construction of conversational networks to discuss HIV related issues, the impact of social stigma on risky behaviors, and how subjective expectations from parents can influence childhood obesity. Understanding where people seek information and how they react according to the social environment is shown to be important in designing effective prevention policies and programs. In the first chapter we investigate the formation of informal HIV conversational networks in rural Malawi. Using data from the Malawi Longitudional Study of Familes and Health (MLSFH), which contains detailed data on conversational networks, we compare the overlap of conversational partners between the network formed to discuss family planning and the one formed to discuss HIV-related issues. If networks were constructed randomly, there should be a high overlap in the composition of different networks for the same individual, as the establishment of a social link is costly. We find evidence that points toward a strategic behavior of individuals by concluding that people (1) vary the composition of their networks; (2) select partners to talk with about HIV who are able to provide them with new information, and (3) both men and women who perceive themselves to be less likely to be infected or to be less exposed to HIV risk consistently look for partners who can provide them with better information. The second paper is a joint work with Adeline Delavande and Neeraj Sood. We estimate the causal effect of social stigma against HIV+ persons on risky sexual behavior in rural Malawi by using plausibly exogenous variation in stigma arising from the introduction of a radio campaign seeking to reduce social stigma. The effect of stigma on risky behavior is a priori ambiguous. On the one hand, higher stigma can lead people to disassociate from the stigmatized group and hence promote risky behavior. On the other hand, stigma can be viewed as a social tax on being HIV+ and higher stigma may reduce risky behavior as a result. We find that an increase in social stigma is associated with an increase in risky behavior, including more partners and a higher likelihood of having extra-marital relations. This effect is mainly driven by the impact of stigma on men. The third chapter of this dissertation tackles the childhood obesity epidemic, by introducing two new approaches: the subjective expectations that parents have about the probability of future childhood obesity conditional on their choices of energy intake and expenditure, and the distribution of decision-power within the household. To identify these two new explanations for childhood obesity we designed and administered a survey in seven primary schools that resulted in an unique dataset covering three districts from Portugal and 220 respondents. Evidence points to the conclusion that parents have accurate expectations about the impact of consuming soft drinks and having an active life. Nevertheless, parents tend to believe that limiting soft drink consumption plays a more important role in fighting childhood obesity, and under-value the importance of physical exercise. This leaves room for policy making in promoting the right balance in the energy intake and expenditure. Moreover, we show that parents who have a higher decision-power within the household and those who perceive a higher increase in the probability of obesity when increasing soda consumption, are the ones whose children drink less of such beverages. All in all, this dissertation contributes to the literature of risky behaviors by shedding some light about how the social environment shapes individuals' attitudes and perceptions toward risky behaviors. Not only do people deliberately seek information, they also tend to opt for less risky behaviors when they have a clear image of the risk they face and they live in a tolerant society. This suggests that working on the quality of the society's values and information flow as a whole, could trigger a reduction in risk taking behaviors at the individual level. Description: A PhD Dissertation, presented as part of the requirements for the Degree of Doctor of Philosophy from the NOVA - School of Business and Economics

2012-01-01T00:00:00Z Santos, Fernando Gilberto Teigão dos http://hdl.handle.net/10362/9686 2013-05-23T11:00:12Z 2011-01-01T00:00:00Z

Title: A resiliência enquanto orientação de planeamento regional: uma abordagem integrada e aplicada à região do Alentejo Authors: Santos, Fernando Gilberto Teigão dos Description: Dissertação para obtenção do Grau de Doutor em Ciências do Ambiente pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

2011-01-01T00:00:00Z Aurélio, Diogo http://hdl.handle.net/10362/9685 2013-05-23T10:46:24Z 2010-01-01T00:00:00Z

Title: Lean management implementation: a decision making framework Authors: Aurélio, Diogo Abstract: In this thesis the author proposes a thinking framework for decision makers considering the implementation of Lean Management methodologies in their industrial contex. The framework takes both internal and external context of each case into consderation. A logical order when considering Lean’s implementation is proposed, where strategic considerations should be taken first into consideration, and operational considerations after. Moreover, the framework proposes the power and leverage perspective on transactional exchange as the central factor to determine the strategic success of any implementation. Finally when it comes to operational considerations, a key thinking factor is taken into consideration, which is the potential penetration ability of Lean techniques according to the internal and external context. The framework is applied to a portuguese leading company in the molding industry that has already applied some Lean Management methodologies, which is Logoplaste. Results lead to conclusions that, not only Lean’s suitability varies according to context, but also that the potential penetration ability of Lean techniques decreases as the compliance level to Lean’s core principles increases, and that companies where Lean techniques with low penetration ability are suitable to be used, have a higher propensity to evolve into higher Lean maturity stages. Description: Submitted to the graduate faculty Universidade Nova de Lisboa – Faculdade de Ciências e Tecnologia in partial fulfillment of the requirements for the degree of Master in Industrial Engineering

2010-01-01T00:00:00Z Pedras, Bruno André Cunha de Vallêra Jacques http://hdl.handle.net/10362/9684 2013-05-23T10:29:30Z 2011-01-01T00:00:00Z

Title: Synthesis, characterization and applications of new schiff base fluorescent chemosensors for metal and DNA interactions: conventional and "green" approaches Authors: Pedras, Bruno André Cunha de Vallêra Jacques Abstract: The work presented in this thesis, which has as its central subject the synthesis and applications of new fluorescent chemosensors and probes, can be divided in two major groups. The first one deals with Schiff base-derived fluorescent chemosensors, with application in the detection of metal cations, and the second group concerns the development of new Ru(II) polypyridyl luminescent molecular probes for DNA. Before the description and discussion of the performed work, a general introduction is presented in Chapter I, where emphasis is put on the applications of molecular fluorescence to chemical sensing, in order to obtain a better understanding of the photophysical processes that underlie molecular recognition. This connection is made by defining concepts and giving examples when necessary. A brief mention to the studied analytes and the instrumental methods used both in developing the chemosensors and in their applications is also made. In Chapter II, two new chemosensors possessing crown ether moieties linked through a Schiff base to a bithiophene group are presented. These systems were synthesized and fully characterized, and their application in the sensing of Ni(II), Pd(II), Hg(II) and Na(I) was tested by absorption and emission spectroscopies, and MALDI-TOF MS. Chapter III describes two new pincer-type ligands, in which a thiophene unit is linked through a Schiff base either to pyrene or naphthalene chromophores. Sensing applications for Ni(II) and Pd(II) were investigated by different techniques, and solid complexes with the aforementioned metals were also synthesized. A new tripodal ligand derived from indole and containing three Schiff base groups is introduced in Chapter IV, and its complexes with Zn(II), Cu(II), Ni(II), Hg(II) and Pd(II) are also described. Metal ion titrations of the free ligand with the respective metal salts have been performed, helped by DFT calculations, in order to investigate the role of the central tertiary amine in metal coordination. The search for new luminescent molecular probes to be used in DNA binding is the subject of Chapter V, in which a new family of six Ru(II) polypyridyl complexes is synthesized. The relation between their structure and the binding mode to DNA is studied by absorption and steady-state emission spectroscopies, as well as by timeresolved experiments. Description: Dissertação apresentada para a obtenção do Grau de Doutor em Química Sustentável, especialidade de Química-Física Inorgânica, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

2011-01-01T00:00:00Z