R - Teses de Doutoramento / Doctoral Theses
URI permanente para esta coleção:
Navegar
Entradas recentes
- Towards European Budgetary Union : problems and challenges since the 2007/2008 financial crisis in comparative institutional perspectivePublication . Matos, Nuno Miguel Castelo Branco Albuquerque; Sousa, António Manuel Carneiro da Frada Marques de
- Development and characterization of a novel probiotic germinated quinoa ice cream : nutritional, functional and biological validationPublication . García-Torres, Silvia Melissa; Gomes, Ana Maria; Silva, Cristina Luísa Miranda; Teixeira, José António CoutoIn the field of food research, new ingredients, compounds, and properties in raw materials are constantly being identified, opening knowledge gaps and generating opportunities for the development of innovative products. At the same time, global dietary habits have evolved, driving a growing demand for healthier, more sustainable alternatives aligned with ethical, environmental, and functional principles. Among the main trends are the preference for plant-based foods, the valorization of traditional crops, and the increasing interest in functional foods—those that offer benefits beyond basic nutritional value. The formulation of plant-based foods can be adapted for consumers with lactose intolerance, individuals following vegan diets, or the general public seeking more sustainable and responsible options, which significantly broadens the scope of functional foods. This research aimed to develop a functional ice cream using optimized germinated quinoa flour, incorporating the emerging probiotic Akkermansia muciniphila. Quinoa was selected for its balanced nutritional profile, the presence of bioactive compounds, and its technological adaptability, following a comparative evaluation with other Andean grains (kiwicha and cañihua). Two Peruvian varieties of different colors were used: Rosa de Huancayo (RH, white grain) and Pasankalla (PK, dark grain). Before germination, disinfection treatments were evaluated on the grain, including combinations of chemical agents, heat, and ultrasound. The combination of hot water (50 °C), hydrogen peroxide (2%), and acetic acid (0.1%) proved to be the most effective, significantly reducing microbial load (in aerobic mesophilic bacteria: 1.29–4.08 Log CFU/g) without affecting germination capacity. Enterobacteria showed greater resistance, especially in PK, but the combined treatment achieved the intended objective. Germination was optimized using a factorial design (24, 48, 72 h × 15, 20, 25 °C), evaluating its effect on nutritional content, bioactive compounds, antinutrients, and techno-functional properties. Improvements were identified in calcium (from 97.1 to 140.1 mg/100 g DW in PK; from 87.5 to 135.2 mg/100 g DW in RH), vitamin C (up to 70.22 µg/g DW in PK; 59.23 µg/g DW in RH), and protein content (from 17.09 % to 18.04 % in PK), as well as a reduction of tannins by up to 63% in RH. Optimal conditions for maximizing polyphenols, vitamin C, and protein content, and reducing tannins, were 25 °C for 24 h in PK, and 22.7 °C for 47.3 h in RH, although in the latter only the first two compounds were optimized. With the optimized germinated quinoa flour, a plant-based ice cream formulation was developed using a D-optimal mixture design. The final formulations—RH (8.86% flour, 14.8% fat, 21.3% sugar) and PK (6.00% flour, 13.0% fat, 23.0% sugar)—achieved physical properties comparable to conventional ice cream in terms of viscosity, hardness, and freezing point. The overrun was lower, representing an area for improvement. Nonetheless, the bioactive compounds derived from germinated quinoa were preserved after processing, highlighting antioxidant activity (110.7 ± 8.39 g Trolox equivalents/g DW) in the quinoa RH ice cream. The product’s functionality was evaluated through in vitro simulated gastrointestinal digestion. The ice cream made with RH flour showed sustained release of phenolic compounds, with high antioxidant activity during the gastric phase (up to 1672.57 µg TE/g DW). Regarding A. muciniphila, high viability was maintained during frozen storage (~10⁸ CFU/g), although a progressive decrease was observed during simulated digestion, reaching 10⁵ CFU/g on day 1 and 10³ CFU/g on day 60. Additionally, the impact of the quinoa-based ice cream formulations on gut microbial activity was evaluated by measuring the production of short-chain fatty acids (SCFAs), ammoniacal nitrogen and lactate during in vitro fecal fermentation. Fecal fermentation revealed that quinoa-based ice cream (QIC), with or without A. muciniphila (Akk), stimulated SCFA production, with butyrate (46.95 mM) predominating in QIC and acetate (33.78 mM) in QIC-Akk, while maintaining safe levels of ammoniacal nitrogen. Lactate dynamics indicated balanced microbial fermentation processes. This study presents an innovative strategy for the development of functional ice cream based on germinated quinoa and emerging probiotics. Despite limitations such as reduced probiotic viability during digestion, the results demonstrate the technological feasibility and nutritional potential of Andean grains in plant-based formulations. These findings contribute to the dialogue on sustainable food innovation and the valorization of traditional crops in the design of functional foods.
- Visualising gender through contemporary art : the cases of Portugal and SloveniaPublication . Kovič, Amadea; Silva, Ana Luísa dos Santos Diniz daDrawing on the theoretical and conceptual frameworks of cultural studies, visual culture and feminist art history, this research hypothesises that experiences related to the state of gender equality in two selected young European democracies (Portugal, a democracy since 1974, and Slovenia, a democratic country since 1991) have contributed to the formation of specific forms of feminisms with some observable patterns, which will be investigated through contemporary visual arts. With the aim of contributing to a better understanding of the current state of gender (dis)equality in Europe, particularly in the two selected countries, from the lens of contemporary visual arts, this research centres on a series of six case studies of artworks by Portuguese and Slovenian artists. Critical visual analysis will thus provide an insight into feminisms in the selected countries through the work of the artists.
- Fate of micropollutants and recovery of EPS in aerobic granular sludge technology in events of salt intrusionPublication . Miranda, Catarina da Costa; Amorim, Catarina Raquel Leite; Castro, Paula Maria Lima e; Tiritan, Maria ElizabethWastewater treatment plants (WWTPs) face growing operational challenges, driven by evolving environmental, social, and regulatory demands. There is increasing pressure to enhance the quality of treated effluents to comply with newly imposed directives, as WWTPs must now contend with a wider spectrum of challenges, including the presence of contaminants of emerging concern (e.g., pharmaceuticals), and the fluctuating wastewater composition driven by intensive urbanization and climate change. Currently, WWTPs are transitioning into resource recovery facilities, aligned with circular economy principles. The aerobic granular sludge (AGS) technology stands out for its resilience to diverse stressors and is well-recognized for its resource recovery potential. Despite these capabilities, the combined effects of multiple stressors on AGS remain underexplored. The objective of this thesis was to understand how oscillating wastewater salinity content and pharmaceuticals simultaneously affect AGS performance and microbial dynamics, while also exploring the potential of waste derived materials for a specific environmental application. A lab-scale AGS reactor was operated for over 9 months under variable salinity conditions to evaluate treatment performance and AGS microbiome evolution. The operational stages included a stepwise increase in salinity (from 1.5 to 15 g/L) followed by daily salinity oscillations (between 7.5 and 22.5 g/L). Chemical oxygen demand (COO) was effectively removed from the wastewater, while ammonium and nitrite levels in the effluent reduced progressively, with nitrate persistently detected in the effluent. Phosphate removal initially declined but completely recovered during the daily salinity oscillations. A versatile core microbiome in the AGS was found, mainly composed of nitrifiers, denitrifiers, and extracellular polymeric substances (EPS)-producing bacteria, which most likely contributed to preventing system collapse under salinity stress. Additionally, over 4 months, the effect of daily salinity oscillations and intermittent dosing of the chiral pharmaceuticals venlafaxine (VNF), tramadol (TRA), and their metabolites in wastewater on treatment performance and EPS production was evaluated and linked to shifts in the AGS bacteriome. The liquid chromatography-mass spectrometry technique was used to monitor the concentration of pharmaceuticals and metabolites. Although the removal of pharmaceuticals improved over time, complete removal was not achieved. Even during pharmaceuticals' dosing, COO and ammonium removal remained effective. Nevertheless, EPS content in AGS increased markedly (up to 196 mg/g TSS) with pharmaceuticals' dosing, compared to 132 mg/g TSS reported in their absence. The AGS bacteriome demonstrated high adaptability, characterized by diverse bacterial niches and a core microbiome composed of nutrient-removing and EPS-producing genera (e.g., Paracoccus). The wide microbial diversity, coupled with functional redundancy, may have contributed to stable nutrient removal and system resilience under stressful conditions, providing practical knowledge of the effects of multiple stressors' presence in wastewater, further demonstrating the robustness of AGS under different environmental challenges. Due to the incomplete pharmaceutical removal by the AGS system, a complementary study was conducted to assess the adsorption potential of tuna bone char (TBC), obtained through the pyrolysis of bone waste-derived material, for VNF and TRA. Pharmaceuticals were supplied individually or in combination, in synthetic wastewater matrices with varying salinity content. F0< pharmaceuticals supplied individually, TBC preferentially adsorbed TRA, with experimental q, values varying from 0.77-1.70 for VNF and 0.72-2.14 mg/g for TRA. The adsorption capacity was affected by the salinity content and the co-existence of pharmaceuticals in wastewater, but TBC remained effective in adsorbing both pharmaceuticals from distinct wastewaters. TBC is, indeed, a promising candidate for the removal of pharmaceuticals from wastewater, addressing key targets outlined in updated discharge regulations while aligning with circular economy strategies for water. In line with the growing emphasis on resource recovery in WWTPs, the final study explores the reuse potential of EPS extracted from AGS as soil amendments for agricultural applications. EPS were recovered from different AGS sources, namely from the lab-scale reactor and biomass sourced from two full-scale urban WWTPs. In a 49-day greenhouse experiment, the effect of incorporating 0.5 and 1% EPS doses on maize growth, nutrient uptake, and soil enzymatic activity was investigated against vermicompost and a non amended control. The EPS source and applied dose greatly influenced the amendment performance, with lower doses showing a marginal influence on plant growth and nutritional parameters. Nevertheless, incorporating 1% of EPS offers agronomic benefits, such as increased chlorophyll content, enhanced magnesium and potassium uptake in maize shoots, and stimulated soil enzymatic activities, often outperforming vermicompost. These findings support the use of EPS in agriculture and underscore the value of recycling materials from WWTPs for sustainable agriculture practices.
- As promessas de Deus e as nossas promessas : um lugar de comunhão e de identidadePublication . Gonçalves, Artur Jorge Ramalho Rocha; Rodrigues, Luís Miguel FigueiredoPopular religiosity is a very deeply present reality in many people’s lives and the Christian community. Throughout history, that wasn’t always positively valued and recognized as a means of achieving experience and relation to transcendence. In the context of popular religiosity, vows take a prominent place and demand acknowledgement and reflection. No one can feel indifferent to the thousands of persons who flock every day to sanctuaries to fulfill their vows, and all the underlying suffering related to them. Facing this reality, we intend to understand people’s reaction when facing limit situations, when confronted with their suffering, or when someone close to them; we also seek to understand how to overcome that fragility and what paths are taken to find the solution of the problem, salvation itself. All these questions helped formulate the starting problematic, to understand the concept of vows, from the originating causes to their final fulfillment, and the consequences generated in the personal life and ecclesiastical commitment of the person who made that vow. To achieve this goal, we elaborated the theoretical matrix to the investigation based on the vow’s phenomenon, having chosen some magisterial interventions that could shed some light on the matter in question. We took care to clarify the concepts of ‘popular religiosity’ and ‘popular piety’, and their connection to the concept of vows. In order to frame the problematic, we reflected on God’s promise in the Bible and its implications in the history of salvation. We conducted some in-depth interviews, with individuals who had recently fulfilled some kind of religious vows, and complemented the investigation by interviewing the rectors of the sanctuaries (Sameiro and São Bento da Porta Aberta), which were the main pool of the investigation. For data analysis, we used the software NVivo, which, by previous categorization, allowed reflection and presentation of the obtained results. For a comprehensive analysis of the vow’s phenomenon, we exposed its connection with votive offerings, as the material expression of the vow’s fulfillment. Finally, we sought to understand vows as a theological place, and also in what ways they help the faithful in their faith experience, from the meeting and the communion with the transcendence perspectives. We concluded by launching some challenging suggestions to positively value vows, with initiatives in the context of evangelization, monitoring and pastoral proposals' elaboration. All of them as ways to strengthen the faithful relation of transcendence and their lay co-responsibility in the context of their community. This investigation is the first in-depth study on the problematic nature of the vow’s phenomenon, from a qualitative perspective and is enriched with a theological reading of the subject in question.
- Formação contínua de professores : contributo para compreender as lógicas de ação dos centros de formação das associações de escolasPublication . Vicente, Lília Maria Lopes dos Santos; Alexandre, Fernando Manuel da Silva; Alves, José MatiasIn Portugal, attending CPD activities is a mandatory requirement for teachers to progress in their careers. But the need to obtain the necessary credits conferred by training activities seems to emerge as a factor that limits the purpose of CPD and can often override the real need for professional development. It is therefore unclear whether the objectives of CPD are limited by the career, or whether it is the teachers who, as a result of a context and/or career management practice, have given CPD a more reductive role. In this context, there seems to be a problem in the fact that the government's emphasis on CPD doesn't seem to be reflected in the effects it produces, either in terms of the needs defined by the teachers themselves or in terms of the more immediate objectives of education policy. This perception seems to stem from the choices made in the training plans drawn up by their promoters, which justifies, on the one hand, the need to know their role as inducers of training content and logic and, on the other hand, to know to whom and for what these organisations are accountable. Assuming that the CPD Plans designed by each School Training Centre (CFAE) are capable of merging the needs expressed by teachers, the school clusters, as well as those that emerge from educational policy frameworks (both nationally and internationally), this research aims to study (i) the process through which CPD needs are identified; (ii) how CFAE decode and merge the CPD needs identified by the different actors and stakeholders; (iii) how the CPD plans designed by CFAE operationalise the needs that emerge from the different levels of political decision making (e. g. national policies and international recommendations), and those identified by schools and teachers; and (iv) how effectively the CPD plans fulfil the needs identified at the various levels. This study was carried out within the framework of an interpretative paradigm, with a qualitative approach that sought to apprehend and explore the meanings attributed to the object of study by the different actors. The data collection process was based mainly on documentary analysis and a questionnaire survey. Document analysis was carried out using content analysis according to pre-defined categories. In order to increase the reliability of the analysis of the findings, the data was subjected to triangulation processes. Ethical considerations included informed consent and confidentiality. This study led to the conclusion that the CPD plans drawn up by the CFAE show a disconnect between discourse and practice. The factors that justify this incongruity are diverse in nature and deeply interconnected, highlighting political and bureaucratic regulatory logics that conflict with the real needs of teachers and schools. It was concluded that the CPD should not only be analysed as a set of administrative and political processes, but as an arena of interaction between various agents where tensions between normative prescriptions and institutional practices are manifested. Analysing the interrelations between the macro, meso and micro levels reveals that the coherence of the CPD system cannot be taken for granted, but rather requires an understanding of the dynamics that regulate its configuration and implementation. These dynamics allow us to foresee how the different players manage the tension between the ideal, the necessary and the possible.
- O estigma na pessoa com tuberculose : desafios para o enfermeiro de cuidados de saúde primáriosPublication . Silva, Maria Isabel Pereira; Araújo, Beatriz Rodrigues deStudies suggest that the stigma towards patients with pulmonary tuberculosis is still currently a reality. The stigma related to this disease interferes with the patients’ self-esteem, their quality of life, family and social relationships and, also, with their medical treatment. In Portugal, this stigma matter towards patients with pulmonary tuberculosis has not been deeply investigated, despite some studies occasionally suggesting its relevance. This investigation analyses the stigma related to pulmonary tuberculosis patients, in Pulmonary Diagnostic Centres of the northern regions of Portugal and is carried out in two stages. The first stage comprehends a preliminary study, of qualitative nature, on nurses from Pulmonary Diagnostic Centres of continental Portugal. This preliminary study aims to identify whether stigma is present in nurses’ speeches. The results from this study and the theoretical background available show that the stigma towards tuberculosis in Portugal is a reality, which intensifies the importance of exploring this matter. The second stage presents the study of the stigma of tuberculosis from the perspective of the patients and of the nurses of Primary Healthcare. For this purpose, three studies were carried out: “Study I” comprises three methodological studies to evaluate the metrical characteristics of Tuberculosis Related Stigma Scale and of Social Support Satisfaction Scale, and to build and validate the content of the survey “A minha Opinião” (My opinion); “Study II”, of quantitative paradigm, aims to evaluate the stigma and the satisfaction towards the social support, from the perspective of pulmonary tuberculosis patients enduring current medical treatments in Pulmonary Diagnostic Centres or in the follow-up stages; and “Study III”, of qualitative paradigm, explores the matter of stigma in tuberculosis, from the Primary Healthcare nurses’ perspectives, in order to identify stigma manifestations to the person suffering from pulmonary tuberculosis throughout their clinical experience. The results of these studies have confirmed the presence of a high stigma towards patients with pulmonary tuberculosis. Similar results were obtained when analysing nurses’ speeches. The stigma is also present, and nurses appear as victims and, simultaneously, as stigma boosters. The National Healthcare System and their orientations are, cumulatively, a source for stigma towards the patients. Lastly, through data triangulation, we were able to understand and consolidate the answer to the research question that triggered this investigation. We have also described the broadness of the stigma in our sample panel, and we have also verified that not only the stigma remains a reality in society, but it also causes economic impact and physical, moral, and social suffering, therefore motivating discouragement, or even depression, and favouring social and family isolation of the diseased. We have concluded this investigation by showing an explicative model of the stigma felt by the pulmonary tuberculosis patient, where it is possible to see its origin and consequences to the diseased and family members, and healthcare professionals. Globally, these results suggest the need to reflect on the healthcare policies for this disease and its treatment and, simultaneously, the need to empower healthcare professionals in this matter. Considering that, for public health reasons and for a Greater Good, the benefit of permanent monitoring persists, with emphasis on the medication intake directly observed by health professionals, there are currently tools and resources that may aid the nurse and the patient to fulfil desired goals regarding the treatment journey and efficiency. These tools may add value to the binomial diseased patient-healthcare system, protecting both the patient and the nurse; and to the healthcare system, by helping achieve the desired targets. This should constitute the main focus of clinical practice and research, since this is a particularly relevant aspect to the pulmonary tuberculosis patient’s care, in Portugal.
- Creativity as performance : on the cultural conditionsof western art music interpretationPublication . Hilsdorf, Leonardo Marranghello; Hanenberg, Peter HeinrichThis thesis aims to contribute to the understanding of creativity in Western music performance. Building upon Glaveanu (2020) and Csikszentmihalyi (1988) cultural theories of creativity, this study focuses on the understanding of music performance creativity as a dynamic and transdisciplinary process. It similarly aims to address the commonly held notion that modern pianists exhibit lower levels of originality compared to previous generations. In order to do this, it will analyse creativity in musical performance from three interrelated and interdependent perspectives: individual, societal, and cultural. From the perspective of the individual creator, I will examine the role of the performer as a co-creator, as well as the notions of interpretation as the catalyst for newness in Western music performance. A comparative case study between eight distinct renditions of the Mazurka op. 59 n.1 by Chopin is developed. The performances were selected from live recordings of the semi-finals of two distinct editions (1980 and 2015) of the International Chopin Competition in Warsaw. The objective of the suggested case study is to demonstrate that a single noted musical composition has multiple interpretative truths, so establishing the initial stage for a performance to be deemed innovative. Nevertheless, creativity mostly refers to a cultural designation given to novel artefacts following societal approval. Hence, to examine under which cultural conditions an innovative performance is regarded as creative, the thesis will situate the analysed performances within a performative tradition in Western art music that is passed down orally through generations. Additionally, it will explore the impact of digitalization of recordings archive on the performers in modern society. Finally, to address the social role in selecting the appropriate variants worth being preserved, Ivo Pogoreli 's elimination in the 1980 Chopin Competition will be discussed, analysing the social reactions of specialised critics and audience members. This case will address the concept of transgression as a generative will that fosters the new, and also explore the distinction between an innovative performance deemed creative by field members versus those perceived as bizarre or idiosyncratic. To address the hypothesis of the current homogenization of modern pianists, this study examines musical creativity as a procedural occurrence that is influenced by socio-cultural forces, and unique to different cultures and performing styles throughout history. The conclusion evidences the limiting role that society and cultural traditions have in promoting and embracing innovative interpretations, revealing a paradox between the praise of novelty within Western art music performance and its constricted limits of its acceptance.
- Eficácia e impacto do ensino : perspectivas de professores e alunosPublication . César, Bruno Miguel Santos; Soares, DianaTeaching effectiveness is widely recognized as an essential factor for educational success, with a direct impact on students' academic performance and the quality of the teaching-learning process. Teachers' ability to motivate, guide, and implement effective pedagogical strategies plays a crucial role in the learning process and the development of students' competencies. Thus, understanding the different elements that constitute teaching effectiveness is fundamental to improving educational practices and maximizing the positive effects of teaching. Based on this framework, this study aims to explore: "What are the main characteristics of teaching effectiveness, and how is it perceived by teachers and students?", more specifically, it addresses the following subquestions: What are the main characteristics of effective teachers?, What are the key dimensions associated with teacher self-efficacy, from the perspective of Portuguese teachers and in an international context?, What are students' perceptions of teaching effectiveness?, What are the divergences and convergences between teachers' and students' perceptions of teaching effectiveness? and How does students' academic performance influence their perception of teaching effectiveness?. The results highlight the multidimensional nature of teaching effectiveness, integrating three key aspects: student engagement, classroom management, and instructional practices. This concept is also perceived differently by teachers and students. While teachers assess their effectiveness based on the application of pedagogical strategies, students place greater value on the clarity of explanations, individualized support, and interpersonal relationships. Additionally, students' academic performance appears to influence their perception of teachers. High-achieving students tend to evaluate teachers more positively, whereas those facing academic difficulties present more critical perceptions. These findings reinforce the need for differentiated and inclusive pedagogical strategies that address students' individual needs and promote equitable teaching. Moreover, the results emphasize the importance of continuous teacher training to ensure the ongoing improvement of pedagogical practices, the implementation of innovative student-centered methodologies, and the strengthening of the teacher-student relationship.
- Photographic poiesis : transformative knowledge of African photographic practicesPublication . Brant, Alfredo; Silva, Ana Luísa dos Santos Diniz daThis doctoral dissertation explores the production of transformative knowledge through creative practices in the realm of contemporary African photography. It draws on visual culture and postcolonial studies as its primary theoretical framework, and decolonial praxis as a guide for concrete interventions in the social sphere. The principal question posed by this investigation is: How can the strategies available in photographic practices afford transformative knowledge? In addition to shaping society through engaged modes of image production, photography enables practitioners to visually decode the world in a unique way. To that extent, it provides access to the subjective sphere, assisting individuals to cope with personal experiences, emotions, and desires. Moreover, photographic practice produces transformative knowledge when it operates as a mechanism for self-learning. Therefore, it is argued that ‘photographic thinking’ is an empowering tool that promotes a decolonial aesthesis (Mignolo and Vazquez 2013) by challenging restrictive Western notions – such as aesthetics and poetics – and allowing a space for micro-narratives to emerge. In approaching the Catchupa Factory residency as a space for learning based on an emancipatory conception of education, we propose the notion of photographic poiesis. It seeks to establish a more dynamic connection between the discipline of visual literacy and photographic production. Such a linkage leads us to a reflection on the pedagogical aspects within the institutional framework of an artistic residency devoted to emerging African photographers, and how it can effectively generate non-hegemonic visual knowledge, social change, and self-actualization. The results are expected to contribute to visual literacy by providing new tools for artists, educators, curators, and practitioners working with photographic images.