How influencers’ credibility on Instagram is perceived by consumers and its impact on purchase intention

The purpose of this thesis is to understand the perception Instagram users, in other words consumers, have of influencers they follow on Instagram. Consumer perceived credibility of influencers, and its impact on the purchase intention, is therefore studied. This dissertation aims to highlight which credibility dimensions better explain the purchase intention. Gender is also explored to verify behavior differences between female and male consumers. To better analyze the perceived credibility of influencers and purchase intention, scales previously developed were applied and adapted as proposed by Ohanian (1990) and Dodds, Monroe & Grewal (1991), respectively. The present study is exploratory and quantitative. It was implemented through an online survey, where only active Instagram users that follow one or more influencers on the platform were selected. Overall, 285 valid responses were collected. The results of the present study indicate that perceived “attractiveness” and “trustworthiness” of influencers are the dimensions of credibility that better explain consumers’ purchase intention. In what concerns gender differences, it is verified that more female than male consumers are influenced by perceived trustworthiness. The developed model aims to support brands and marketers in better understanding the effects perceived credibility of influencers has on consumption, and of its impact in purchase intention.O propósito desta tese é compreender as percepções que os utilizadores do Instagram, que neste caso são os consumidores, têm para interagir com influenciadores no Instagram. Desta forma, é estudado o impacto que a credibilidade percebida pelos consumidores nestes Influenciadores tem na intenção de compra. Esta dissertação visa destacar quais os tipos de credibilidade que melhor explicam a intenção de compra. Os dois géneros dos consumidores são também explorados, de modo a verificar se há diferenças no comportamento entre os homens e mulheres. Para compreender melhor o impacto que os influenciadores têm nas percepções de credibilidade dos consumidores e na intenção de compra, foram utilizadas e adaptadas escalas previamente propostas por Ohanian (1990) e Dodds, Monroe & Grewal (1991), respectivamente. O presente estudo é exploratório e quantitativo. Na fase de recolha de dados foi feito um questionário online, onde foram selecionados apenas os utilizadores do Instagram que se consideram activos e que seguem um ou mais influenciadores na plataforma. No total foram obtidas 285 respostas válidas. Os resultados obtidos neste estudo indicam que a “atractividade” e a “confiabilidade” percebida pelos consumidores nos influenciadores são as dimensões de credibilidade que melhor explicam a intenção de compra. Relativamente às diferenças entre homens e mulheres, constata-se que a percepção da confiabilidade de um influenciador tem mais influência nas mulheres do que nos homens. O modelo desenvolvido tem como objectivo auxiliar marcas e marketeers a compreender melhor o impacto que a credibilidade percebida pelos consumidores nos influenciadores tem na intenção de compra

The characteristics of social entrepreneurship business models in Portugal

This work project is based on the MIES (Map of Innovation and Social Entrepreneurship in Portugal) database and it aims to understand the characteristics of social business models in the context of the portuguese market, by determining whether they follow the proposed characteristics by John Elkington and Pamela Hartigan, and then adding to their matrix. Furthermore, it tries to determine success patterns by comparing a group of successful social ventures with a group of less successful ones, with the objective of increasing the knowledge of social entrepreneurship as it applies to Portugal and provide a framework for future study

Oxidative status in feline pyometra

The oxidative status of the organism is dependent of the balance between oxidant reactants and antioxidant defenses. Oxidative stress develops when the oxidant reactants exceed the antioxidant defenses of the organism. The oxidative stress causes alterations in cellular metabolism and cellular damage. The antioxidant response of the organism can be assessed by determination of individual parameters such as total serum thiols (Thiol) and/or by determination of the total antioxidant capacity (TAC) of the organism. Parameters of oxidative status have proved to be useful biomarkers in several canine and feline diseases. Pyometra is considered one of the most important uterine diseases in cats. However, information about the oxidative status in queens with pyometra is lacking. Therefore, the main objectives of this study were to evaluate the oxidative status of feline pyometra through the determination of serum concentration of Thiol and TAC, and to evaluate the clinical evolution of these antioxidants in the post-ovariohysterectomy period. Serum concentrations of Thiol and TAC (determined by four different methodologies) were assessed in 17 queens with pyometra and in 13 healthy queens submitted to elective ovariohysterectomy (control group). Serum Thiol and TAC were also evaluated in six queens with pyometra at days two and 10 after surgery. Routine histopathology of the reproductive organs was performed in all animals, to confirm pyometra in the diseased queens, and to exclude uterine pathology in the control cats. At presentation, diseased queens presented significantly lower serum concentrations of Thiol and TAC than controls (P<0.001 in both cases). In the queens in which serial determinations of antioxidants were performed, serum Thiol and TAC were significantly higher at day 10 post-surgery than at presentation (P<0.05 in both cases). The results of the present study indicate that pyometra in queens is associated with presence of oxidative stress. Moreover, serum Thiol and TAC tended to evolve to physiologic values after surgery. Therefore, oxidative stress parameters could be useful in assessing the post-operative period in feline pyometra.O estado oxidativo do organismo depende do equilibrio entre os agentes oxidantes e os antioxidantes. O stresse oxidativo de senvolve-se quando os agentes oxidantes excedem a capacidade antioxidante do organismo. O stress oxidativo causa danos celulares, bem como alterações no seu metabolismo. A resposta antioxidante pode ser avaliada através da determinação de parâmetros individuais, tais como os tióis séricos, ou através da determinação da capacidade antioxidante total (TAC, do Inglês Total Antioxidant Capacity) do organismo. Diferentes parâmetros de avaliação do estado oxidativo do organismo provaram ser biomarcadores clinicamente úteis em diferentes doenças em cães e gatos. Contudo, existe falta de informação sobre o estado oxidativo em gatas com piómetra. Desta forma, os objetivos principais deste estudo foram avaliar o estado oxidativo em gatas diagnosticadas com piómetra, através da determinação dos níveis séricos de tióis e TAC (determinados através de quatro métodos diferentes: TEAC1, TEAC2, FRAP E CUPRAC), e avaliar a evolução clínica destes antioxidantes no período pós-ovariohisterectomia. As concentrações séricas de tióis e TAC foram determinadas em 17 gatas com piómetra (grupo em teste) e em 13 gatas saudáveis submetidas a ovariohisterectomia eletiva (grupo de controlo). Em seis gatas com piómetra foi possível efetuar o doseamento de tióis e TAC nos dias dois e 10 após a cirurgia. Foi realizada histopatologia dos órgãos reprodutores de todas as gatas incluídas no estudo, para comprovar a presença de piómetra nas gatas doentes, e para excluir doenças uterinas no grupo de controlo. No momento do diagnóstico, as gatas com piómetra apresentaram concentrações séricas de tióis e TAC significativamente inferiores às gatas do grupo de controlo (P<0,001 em ambos os casos). Nas gatas em que foi realizado um seguimento no período pós-cirurgia através de medições seriadas de antioxidantes, as concentrações de tióis e TAC apresentaram-se significativamente superiores no décimo dia pós-ovariohisterectomia que no dia do diagnóstico (P<0,05 em ambos os casos). Segundo os resultados obtidos neste estudo, em gatas a piómetra está associada ao desenvolvimento de stresse oxidativo. Para além disso, as concentrações séricas dos antioxidantes analisados tenderam a retomar os valores fisiológicos no período pós-ovariohisterectomia. Assim, estes parâmetros indicam utilidade clínica na monitorização do período pós cirúrgico em gatas com piómetra

«I’m a storyteller» Interview with Jean-Louis Cohen

Jean-Louis Cohen was brought up during the Cold War in Paris, between the portraits of Einstein and Stalin, in a family of left-wing scientists. Regardless of having become an architect, a different professional career of his parents, they had inevitably marked his future. The rigorous way in which he later worked as an architectural historian is symptomatic of this, as is the way in which he maintained a heterodox left-wing ideology that accompanied him throughout his life. He studied in Paris at a time when it was possible to attend a lecture by the psychoanalyst Jacques Lacan, the philosopher Michel Foucault or the writer Roland Barthes within a 500-metre radius. But it was Jean Prouvé's classes — who was, after all, a metalworker and self-taught architect — that made him realise that architecture is, above all, an activity of action and of construction. He started travelling at that time. Firstly, to visit works of architecture, and later to reveal them to the world (a task he never abandoned). With a unique critical sense, Cohen has spent his life dismantling some of the false and clear ideas on which Western historiography has been based. He has organised some of the most extraordinary architectural exhibitions of the 21st century, such as Architecture in Uniform: Designing and Building for the Second World War (2011), Le Corbusier: An Atlas of Modern Landscapes (2013), Modernity: Promise or Menace? (2014) or the most recent Building a new New World: Amerikanizm in Russian Architecture (2020). Jean-Louis Cohen was not just one of the most important contemporary architectural historians. He was much more than that. Given his eclectic nature he impersonated the architectural historian of contemporaneity himself. He left us unexpectedly on 7 August 2023. When we conducted this interview, we were far from knowing that it would be one of his last, nor that it would take place just before he gave one of his last lectures, as part of the PhD in Contemporary Architecture at the Autonomous University of Lisbon. In this interview, he portrayed himself as a storyteller, underscoring that his research evolves through the narrative act — whether in a classroom, an exhibition, or a book. The various mediums that characterised his prolific output were essentially tools for testing his thoughts and advancing toward his overarching goal: the pursuit of knowledge

Optimization of screening methods for the evaluation of the antileishmanial potential of halophytes and macroalgae from the Iberian coast

Leishmaniases are parasitic diseases caused by Leishmania parasites, which are transmitted to mammals by the bite of sand flies. In the Mediterranean basin, L. infantum is the etiological agent of human visceral leishmaniasis, the most severe form of the disease. The obvious limitations of current available drugs still provide an undoubtedly motivation for research of novel compounds with antileishmanial potential. In the last decades, marine organisms or species living in a terrestrial habitat strongly influenced by the sea have been shown to be potential sources of rich bioactive compounds. Thus, the search for marine natural products with antileishmanial activity has gathered interest and, as a result, some promising extracts and compounds have been described. For assessment of the in vitro activity of natural extracts mainly axenic promastigotes and amastigotes have been used. Although the amastigote-macrophage system remains the ideal model, its use has been neglected mainly due to the lack of sensitive and rapid in vitro screening methods, which rely on the inherent difficulties of the intracellular stage. In this context, the main objective of this work is to contribute for the study of the antileishmanial potential of macroalgae and halophytes, through the optimization of screening methods focusing on the intracellular amastigote form. The direct counting method was optimized and used for the assessment of extracts activity against intracellular amastigotes. Concerning the parasite rescue assay, lysis conditions were established. However, aberrant results were obtained when the effect of amphotericin B and that of different infection ratios was assessed, in comparison to the direct counting method results. As the complete optimization of the parasite rescue assay was not possible and reminding the shortcomings of the direct counting method, halophyte and macroalgae extracts were tested against L. infantum promastigotes. Halophytic extracts were in general inactive against L. infantum promastigotes. Spergularia rubra and Inula crithmoides dichloromethane extracts were the most active, but were also extremely cytotoxic towards THP-1 macrophages. Concerning macroalgae, the hexane and dichloromethane extracts of Cystoseira tamariscifolia and the hexane extract of C. usneoides were highly active towards the promastigotes with IC50 values below 35 μg mL-1, yet they had also poor selectivity. C. baccata hexane extract was the most selective algal extract (SI > 1.32). Additionally, C. baccata and C. barbata hexane:dichloromethane extracts, obtained by hot soxhlet extraction, displayed interesting antileishmanial activities (IC50, 50.2 ± 2.6 and 15.1 ± 2.9, respectively) towards the intracellular stage of L. infantum combined with promising SI values (>2.5 and >8.3, respectively), reinforcing the main argument of this work that intracellular amastigotes are the ideal in vitro model to be used in drug screening purposes, which may yield a larger number of positive hits if implemented in future screening efforts

Summarization of Films and Documentaries Based on Subtitles and Scripts

We assess the performance of generic text summarization algorithms applied to films and documentaries, using the well-known behavior of summarization of news articles as reference. We use three datasets: (i) news articles, (ii) film scripts and subtitles, and (iii) documentary subtitles. Standard ROUGE metrics are used for comparing generated summaries against news abstracts, plot summaries, and synopses. We show that the best performing algorithms are LSA, for news articles and documentaries, and LexRank and Support Sets, for films. Despite the different nature of films and documentaries, their relative behavior is in accordance with that obtained for news articles.Comment: 7 pages, 9 tables, 4 figures, submitted to Pattern Recognition Letters (Elsevier

Lifestyle impact on serum level of vitamin D and PTH, in elderly

Introduction: The aging process is responsible for health decline and may lead to the dependence and consequent institutionalization. Bone metabolism involves serum calcium regulators, such as vitamin D and PTH. Objetives: The following study evaluated and compared serum concentrations of 25(OH)D and iPTH in elderly people living in institutions and living in their homes (free-living), with active and independent life. Methods: We evaluated 50 elderly (25 institutionalized and 25 not institutionalized). We made an individual questionnaire and we collected blood to measured the serum concentrations of iPTH and 25(OH)D. Results: Not institutionalized elderly showed higher 25(OH)D serum levels, comparing with institutionalized elderly (pvalue<0,05). The serum concentration of 25(OH)D was inversely correlated with iPTH. Furthermore calcium supplementation correlated with higher serum levels of 25(OH)D (p-value<0.05) and lower concentrations of iPTH (p-value<0,05). The free-living elderly who practice three or more activities per day, had higher concentrations of 25(OH)D (p-value<0.05) and lower concentrations of iPTH (p-value<0.05), compared to the institutionalized elderly. Outdoor activities showed also correlation with serum concentrations of both hormones (p-value<0.05). Conclusion: The adoption of an active lifestyle and the contact with nature, carry profit to a better aging process.info:eu-repo/semantics/publishedVersio

The role of Notch-signalling in avian thymus and parathyroid glands development

The thymus generates central immune tolerance by producing self-restricted and self-tolerant T-cells, while the parathyroid glands regulate extracellular calcium homeostasis through the production of the parathyroid hormone (Pth). Despite their functional differences, they share a common endodermal origin in the pharyngeal region, which in avian corresponds to the endoderm of the 3rd and 4th pharyngeal pouches (3/4 PP). The involvement of several transcription factors and signalling pathways (including the Hedgehog pathway) during the early stages of thymus and parathyroid glands (T/PT) development has been reported over the years. However, the molecular mechanisms and interactions between major signalling pathways regulating their early development are still poorly understood. Namely, the potential contribution of Notch signalling – one of the major pathways involved in cell-fate determination and boundary formation – at these early stages remains unknown. Recently, and using the avian model, we observed the expression of Notch-related molecules in the presumptive territories of T/PT. In addition, during my master’s thesis I showed that the pharmacological inhibition of Notch signalling at these stages of T/PT development blocked Gcm2 (parathyroid marker) and altered Foxn1 (thymic marker) expressions, detected through in situ hybridization. These data suggest a potential role of Notch signalling during thymus and parathyroid glands early development. In addition, Notch and Hedgehog pathways have been shown to interact in several biological contexts. In this thesis, we investigated the role of Notch signalling at the early stages of T/PT development, and its possible interaction with Hedgehog in this context. Using the quail-chick developmental model and pharmacological inhibitors in vitro and in vivo, we show, for the first time, that Notch is crucial for T/PT common primordium development and for parathyroid formation. Notch signalling was found to be required (within a 48h time-window) for the normal expression of Foxn1 and Gcm2 at early stages of development. Moreover, Notch signals within this time-window were found to be crucial for parathyroid glands formation. We also show that Hedgehog acts upstream of Notch during T/PT early development. Hedgehog positively regulates the median domains of the pouch endoderm – the Gata3+/Gcm2+ anterior domain and the Lfng+ posterior domain – which seem to be more Hedgehog-responsive than the pouch tips, namely the dorsal tip where the thymus is formed. In addition, we provide evidence that the Lfng-expression domain is involved in the definition of the dorsal/posterior boundary of Foxn1/thymic rudiment. To clarify the tissue-specific role of Notch signalling at the early stages of T/PT development, isolated quail 3/4PP endoderm was electroporated with a Tol2-mediated gene transfer and tetracycline-dependent conditional expression system of vectors generated during my master thesis to induce loss- and gain-of-function of Notch signalling. A new loss-of-function construct (pT2K-NLS-Cherry-DNMAML1-eGFP) was also developed. However, the results obtained using the tested conditions were inconclusive, limiting the analysis of tissue-specific roles of Notch signalling in T/PT development during this thesis. This work provides new insights into the role of Notch signalling in T/PT early development, and into the interactions between major signalling pathways that regulate this development. However, which tissue – the endoderm or the surrounding mesenchyme – is the main driver of these Notch effects remains unanswered