2,008 research outputs found
Approche combinée de thérapie génique non-virale et d’ultrasons pour l’immunothérapie du cancer
No full textL'immunothérapie anticancéreuse est une stratégie thérapeutique prometteuse partie prenante de nombreux protocoles de traitement du cancer. L'IL-12 est une cytokine thérapeutique impliquée dans l'induction de réponses immunitaires à la fois innées et adaptatives. Cependant, l'application clinique de l'IL-12 a été entravée par une toxicité sévère. Cette toxicité pourrait être atténuée lors de l'expression d'IL-12 localement avec un vecteur de délivrance de gène tel que des liposomes cationiques. De plus, de nombreux essais précliniques ont montré les effets antitumoraux remarquables des techniques d'ablation tumorale associées à l'immunothérapie. Sur la base de ces connaissances, nous avons proposé un projet pour étudier l'effet d'immunomodulation, une combinaison entre la transfection du gène IL-12, un lipide cationique jouant le rôle d'adjuvant et l'ablation par ultrasons focalisés chez des souris porteuses de tumeurs. Par ailleurs, afin d'augmenter la quantité de plasmide intratumoral, un ciblage magnétique avec des liposomes cationiques magnétiques (MCL) a été envisagé. Dans la première partie, des MCLs de moins de 200 nm, positivement chargés, ont été préparés avec succès par 2 méthodes, la sonication cosolvant (cosol) et l'évaporation en phase inverse (REV). Ces deux formulations MCL ont montré des relaxivités IRM r2 élevées à 7T et une efficacité de lipoplexation élevée. En outre, les cosol_MCL se sont révélés supérieurs aux REV_MCL, en particulier en termes d'efficacité de transfection. De plus, en présence d'un champ magnétique externe, l'internalisation et la transfection avec des complexes cosol_MCLs / ADNp ont été améliorées. Les cosol_MCL et leurs lipoplexes pourraient être appropriés pour être appliqués dans la délivrance systémique de gènes car ils se sont avérés ne pas être cytotoxiques pour les hépatocytes même à haute concentration. Bien que l'efficacité de ciblage sur le site de la tumeur avec un aimant, n'ait pas été très important ciblés, ces MCLs sont des agents de contraste T1 permettant d'améliorer le contraste IRM in vivo et de suivre ces agents chez la souris. Dans la deuxième partie de mon projet, diverses conditions d'échographie focalisée à haute intensité (HIFU) ont été testées in vitro pour leurs effets sur les cellules cancéreuses CT26. Nous avons constaté que la valeur seuil de la dose thermique, CEM43 ° C, pour la mort cellulaire était d'environ 10^3 minutes. De plus, un CEM43 ° C de 10 à 10^5 minutes a provoqué la libération et l'expression maximales de hsp70 dans les cellules CT26 traitées par HIFU. L'étude in vivo réalisée a permis de montrer que l'application de HIFU 80T 60s permet non seulement d'induire l'ablation de la tumeur mais aussi d'activer les cellules T cytotoxiques pour la production de TNF-a. De plus, en raison de la transfection inefficace des lipoplexes même après injection i.v ou locale, l'injection d'ADNp nu dans la tumeur a été choisie. Le pFAR4.2-mIL12 nu a été transféré avec succès et a montré certains avantages dans l'activation des cellules T. De même, le lipide cationique YUK 1350 s'est avéré stimuler l'activation des cellules T. La combinaison de ces 3 traitements a également montré un effet d'immunomodulation amélioré. En conclusion, au cours de cette thèse, une formulation de MCL a été préparée et optimisée avec succès pour la transfection in vitro. En outre, l'effet de HIFU sur les cellules CT26 a également été évaluée in vitro. Les premiers résultats de la transfection pFAR4.2-mIL12, de l'ablation HIFU, de l'injection de lipides cationiques et de leur combinaison sur la réponse immunitaire ont pu être réalisés. D'autres études devraient être menées pour optimiser la transfection avec des liposomes cationiques, la technique d'ablation HIFU et leur association pour l'immunothérapie.Cancer immunotherapy is a promising modality of therapy that becomes an important component of many cancer treatment protocols. Among many immunotherapeutic agents, IL-12 is an important cytokine which is involved in the induction of both innate and adaptive immune responses. However, the clinical application of IL-12 has been hampered by severe toxicity. This toxicity could be attenuated when expressing IL-12 locally with a gene delivery vector such as cationic liposomes. In addition, many pre-clinical trials have shown the outstanding antitumor effects of tumor ablation techniques combined with immunotherapy. Based on these knowledge, we proposed a project to study the immunomodulation effect a combination between IL-12 gene transfection, immune activating-cationic lipid and HIFU ablation in tumor bearing mice. Our plan was to use magnetic cationic liposomes (MCLs) for magnetic targeting delivery of a plasmid encoding IL-12. In the first part, small MCLs of less than 200 nm with highly positive charge were successfully prepared by 2 methods, cosolvent sonication (cosol) and reverse phase evaporation (REV). These two MCL formulations showed high r2 MRI relaxivities at 7T and high lipoplexation efficiency. Furthermore, the cosol_MCLs were shown to be superior to the REV_MCLs, especially in the transfection efficiency. Moreover, in the presence of an external magnetic field, the internalization and transfection with cosol_MCLs/pDNA complexes were enhanced. The cosol_MCLs and their lipoplexes could be suitable to be applied in systemic gene delivery as they were proved to be not cytotoxic to hepatocytes even at high concentration. Although the lipoplexes were not highly targeted at the tumor site with a magnet, they acted as a good MRI contrast enhancement agent in vivo. In the second part of my project, various High Intensity Focused Ultrasound (HIFU) conditions were tested in vitro for theirs effects on CT26 cancer cells. We found that the threshold value of the thermal dose, CEM43°C, for cell death was about 10^3 minutes. Moreover, CEM43°C of 10 to 10^5 minutes caused the maximal release and expression of hsp70 in HIFU treated CT26 cells. There were some enhancement, even not significantly, of HIFU treated CT26 compared to the non-treated ones in stimulation of DCs in vitro. From in vivo study, the HIFU 80T 60s was found to not only induce tumor ablation but also activate cytotoxic T cells for production of TNF-a. Besides, due to the inefficient transfection of the lipoplexes even after i.v or local injection, injection of naked pDNA in the tumor was chosen. The naked pFAR4.2-mIL12 was successfully transferred and showed some benefits in activating T cells. Similarly, cationic lipid YUK 1350 was shown to stimulate T cells activation. The combination of these three treatments also exhibited an enhanced immunomodulation effect. In conclusion, during this PhD, a MCL formulation was successfully prepared and optimized for in vitro transfection. Besides, effect of HIFU on CT26 cells also evaluated in vitro. The initial results of pFAR4.2-mIL12 transfection, HIFU ablation, cationic lipid injection and their combination on the immune response were shown with some positive results. More studies should be carried out to optimize the transfection with cationic liposomes, the HIFU ablation technique and their combination for immunotherapy
Building a Graph Database for Digital Humanities Scientists
No full textGraph database has developed rapidly and plays an important role in research nowadays. It helps scientists in various ways, e.g., finding related works, exploring works in a research area, or gaining knowledge from connections between different nodes. There are already some graph databases for research available on the Internet. However, they do not meet the needs of Digital Humanities (DH) scientists, who mainly work with historical data. Therefore, we create a graph database specifically for DH scientists. This database is part of MINE, a service that facilitates data acquisition and big data analysis
Laura Doan, Disturbing Practices History, Sexuality and Women’s Experience of Modern War
No full textLaura Doan is professor of cultural history and sexuality studies at the University of Manchester (UK). She is the author of Fashioning Sapphism : The Origins of a Modern English Lesbian Culture (2001). Her latest monograph, Disturbing Practices is a thought provoking innovative book that takes us well beyond the central focus presented in the subtitle: History, Sexuality, and Women’s Experience of Modern War. At the same time a history book and a book on the making of history Disturbing Prac..
Convolutional Autoencoder for the Spatiotemporal Latent Representation of Turbulence
No full textTurbulence is characterised by chaotic dynamics and a high-dimensional state space, which make this phenomenon challenging to predict. However, turbulent flows are often characterised by coherent spatiotemporal structures, such as vortices or large-scale modes, which can help obtain a latent description of turbulent flows. However, current approaches are often limited by either the need to use some form of thresholding on quantities defining the isosurfaces to which the flow structures are associated or the linearity of traditional modal flow decomposition approaches, such as those based on proper orthogonal decomposition. This problem is exacerbated in flows that exhibit extreme events, which are rare and sudden changes in a turbulent state. The goal of this paper is to obtain an efficient and accurate reduced-order latent representation of a turbulent flow that exhibits extreme events. Specifically, we employ a three-dimensional multiscale convolutional autoencoder (CAE) to obtain such latent representation. We apply it to a three-dimensional turbulent flow. We show that the Multiscale CAE is efficient, requiring less than 10% degrees of freedom than proper orthogonal decomposition for compressing the data and is able to accurately reconstruct flow states related to extreme events. The proposed deep learning architecture opens opportunities for nonlinear reduced-order modeling of turbulent flows from data.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Aerodynamic
Pham Doan Trang : Prix de l'Impact de Reporters sans Frontières 2019
No full text[ndlr] L'écrivaine et journaliste dissidente Pham Doan Trang a reçu le 12 septembre 2019 à Berlin le Prix de l'Impact de l'association Reporters Sans Frontières en récompense de son travail d'édition, de réflexion et de promotion du journalisme. Elle a prononcé un important discours vidéographique depuis le Viêt-Nam, suivi de celui de l'avocat Trinh Huu Long lors de la remise du prix (montage par RFA Vietnamese). Voir aussi : Nhà báo Phạm Đoan Trang được giải thưởng tự do báo chí 20..
FIGURE 4 in Binhthuanomon vinhtan, a new genus and new species of semi-terrestrial freshwater crab (Crustacea: Decapoda: Brachyura: Potamidae) from south central Vietnam
No full textFIGURE 4. Binhthuanomon vinhtan sp. nov., holotype, male (CW 53.9 mm), ITB-FC PNx01. A-H, right G1: A, ventral view; B, ventral view of terminal segment; C, mesial view; D, mesial view of terminal segment; E, dorsal view; F, dorsal view of terminal segment; G, lateral view; H, lateral view of terminal segment; I, right G2; J, right G2 of terminal segment.Published as part of Le, Van Tu Do Van Tho & Phan, Doan Dang, 2015, Binhthuanomon vinhtan, a new genus and new species of semi-terrestrial freshwater crab (Crustacea: Decapoda: Brachyura: Potamidae) from south central Vietnam, pp. 117-126 in Zootaxa 4052 (1) on page 123, DOI: 10.11646/zootaxa.4052.1.6, http://zenodo.org/record/23793
Review of two genera of freshwater crabs, Larnaudia Bott, 1966 and Neolarnaudia Türkay & Naiyanetr, 1987 (Crustacea: Decapoda: Potamidae) with redescription Neolarnaudiaphymatodes (Kemp, 1923) from Southern Vietnam
No full textABSTRACT: The occurrence of Larnaudia Bott, 1966 in southern Vietnam remains obscure. Although some previous studies described the presence of Larnaudialarnaudii A. Milne-Edwards, 1869 in Vietnam, our analysis of freshwater crab specimens collected at many locations in southern Vietnam revealed that Neolarnaudia Türkay Naiyanetr, 1987, but not Larnaudia Bott, 1966, is present in southern Vietnam. In this study, we recorded two species of Neolarnaudia, N. phymatodes (Kemp, 1923) and N. botti Türkay Naiyanetr, 1987 in southern Vietnam. Neolaurnaudia phymatodes was poorly knownsince the original description, and is, thus, re-described here. This species can be distinguished from all other Neolarnaudia species by a suite of characters; carapace broader, frontal area with many granules, supraorbital margingranulated, suborbital and pterygostomian regions and merus of third maxillipedcovered with many granules, terminal segment of Gonopod 1 strongly curved inwards and covered with many pubescences, lateral margin of telsonstrongly concaved. Citation: Do Van Tu, Dang Van Dong, Le Van Tho, Phan Doan Dang, 2017. Review of two genera of freshwater crabs, Larnaudia Bott, 1966 and Neolarnaudia Türkay Naiyanetr, 1987 (Crustacea: Decapoda: Potamidae) with redescription Neolarnaudiaphymatodes (Kemp, 1923) from Southern Vietnam. Tap chi Sinh hoc, 39(4): 398-405. DOI: 10.15625/0866-7160/v39n4.8464.*Corresponding author: [email protected], [email protected] 19 September 2017, accepted 12 December 201
Airbnb stakeholders´ perceptions and behavioral intentions: the case of Airbnb in Vietnam
No full textResearch on Airbnb accommodation providers and consumers’ perception and behavioral intention has received much scholarly attention within the sharing economy literature in the recent decade. From the literature on consumer side, despite growing interest in studying the effect of electronic word-of-mouth (eWOM) on Airbnb customers’ perception and behavioral intentions through online review mining techniques, limited Airbnb related research was conducted as an empirical study to provide insight into how Airbnb customers with different personal characteristics adopt eWOM, and what are the drivers of their intention to spread positive WOM after the stay experience. In addition, it is worth noting that this study overlapped with the period of the global pandemic, COVID-19 - which has impacted this short-term rental platform seriously, however, less is known about Airbnb customers’ eWOM adoption process and Airbnb hosts’ decision making process in a health-related crisis. Moreover, the large proportion of the existing studies focus on the matured Airbnb markets, while cultural and situational factors were found to hold a great importance on influencing Airbnb stakeholders’ perception and their subsequent behaviours. Thus, this study aims to explore the perception and eWOM related behavioral intentions of Airbnb consumers; and to study the antecedents of Airbnb hosts’ continuance intention with the sharing platform in an emerging sharing economy market – Vietnam, especially in the setting of the global pandemic.
Guided by the positivism paradigm, this research is a combination of four scientific papers which tend to achieve the aforementioned general objectives. More specifically, the first paper of this study utilized the Cognitive appraisal – Emotional response – Coping Behaviour model to re-examine the most commonly confirmed antecedents of consumers’ perceived values towards Airbnb and broadening the comprehension of how these perceived value affect Vietnamese Airbnb consumers’ satisfactions, and electronic and traditional word-of-mouth ((e)WOM) intention. The findings confirmed the significant role of perceived functional benefits, monetary values, and hedonic benefits on encouraging Airbnb consumers’ positive (e)WOM intention directly or indirectly via satisfaction with their stay experience. Results also revealed that the relationships among social interaction, novelty, sustainability, and customer satisfaction were not significant in the Vietnamese Airbnb market. These contradictory findings provide stronger evidence on the critical influence of cultural values in Airbnb customers’ perception and behavioral intentions. Moreover, the novelty of this study lies in the confirmation of the impact of traditional WOM intention on eWOM intention from the message communicators’ perspective, in which this finding has not been discussed until now in any research context.
Second, through extending the Stimuli – Organism – Response model, the next paper of this research expands our understanding of the determinants of Airbnb customer loyalty beyond the well-established contribution of customer satisfaction, since it identified the influential role of perceived enjoyment on Airbnb customers’ intention to spread positive comments towards this accommodation sharing platform. Moreover, the theoretical contribution of this study is also related to the investigation of the moderating role of Airbnb customers’ sociodemographic and tripographic characteristics in the associations among perceived enjoyment, its antecedents (home benefits, social interaction, authenticity and monetary value) and consequences (eWOM intention). The results revealed that these relationships remain unchanged among the different groups of customers, except business travellers, which offer a foundation for the empirical comprehension of this emerging Airbnb target market segment. To achieve the research objectives of the first two studies, an online survey-based questionnaire using a non-probabilistic sampling method was applied to collect data on a sample of Vietnamese customers who had experienced Airbnb accommodation within a year before the period of data collection. A total of 352 questionnaires were collected, from which 163 and 162 eligible Airbnb users in Studies 1 and 2 respectively were retained for data analysis by the application of the Partial Least Square approach to SEM (PLS-SEM).
Third, guided by the conclusion of customers’ distinct eWOM adoption in the literature, this part of the research aims to provide an empirical evidence on explaining the contradictory findings regarding the effect of eWOM on Airbnb consumers’ behavioral intentions through considering the moderating role of consumers’ sense of power and perceived psychological risk towards COVID-19. Furthermore, this work also takes into account the importance of cultural differences in Airbnb customers’ behavioral intentions by carrying out a cross-national study among Italy, Portugal and Vietnam. More particularly, this study expanded the Model of Goal directed Behavior (MGB) to investigate how eWOM influences Airbnb existing and prospective customers’ desire to book Airbnb accommodation indirectly through attitude, subjective norms, perceived behavioral control, anticipated emotions, and trust in hosts which consequently lead to their purchase intention. In order to test the proposed hypotheses, an electronic survey was conducted in these three countries which resulted in a total sample of 1,849 respondents (including 1,146 Italian, 262 Portuguese and 441 Vietnamese Airbnb users and non-users). Airbnb non-users are defined as those who are aware of the Airbnb platform but have never experienced it before. The collected data were later analysed by also using PLS-SEM. The findings found the different moderating role of sense of power and psychological risk in Airbnb customers’ eWOM adoption process across these three research contexts, which confirmed the significance of cultural and situation factors in studying eWOM and Airbnb customers’ behavioral intentions. Furthermore, desire to book the shared accommodation was found as the most influential factor in customers’ purchase intention, which confirmed the suitability of the MGB in studying Airbnb customers’ behavioral intentions in the uncertain situation brought by a global pandemic.
Fourth, the final part of this research shifts the focus to Airbnb accommodation service provider – Airbnb hosts in order to examine the antecedents of their continuance intention with the platform during the COVID-19 pandemic. Airbnb hosts are usually considered as micro-entrepreneurs that are not professionally trained in hotel management. Grounded on the Theory of Planned Behavior (TPB), this study proposes a conceptual framework integrating TPB constructs including Airbnb hosts’ attitude, subjective norms and perceived behavioral control, and a dedication-based factor, so called trust towards Airbnb to study their loyalty intention along with the moderating effect of Superhost badge on the modeled relationships. A sample of 160 Vietnamese Airbnb hosts was observed through an electronic survey and data were later analyzed with PLS-SEM. Findings showed that Airbnb hosts’ attitude, perceived behavioral control and trust towards Airbnb significantly impact their intent to continue listing the assets on the platform. Last but not least, findings confirmed the existence of the moderating role of Airbnb hosts’ status in their decision-making process during an unprecedented pandemic. Thus, this study subsequently enriches the literature on the accommodation sharing industry from the lens of different types of accommodation service providers and contributes to advancing the theory in the field of micro-entrepreneurs’ response towards crises.
This research provides practical implications in two specific ways. First, the findings of this study shed light on Airbnb platform management and Airbnb hosts’s understanding of Vietnamese Airbnb customers’ perceived values, their perception towards the shared accommodation and subsequent eWOM related behavioral intentions. Second, these results also support the platform management company and local authorities in setting up effective management strategies to reduce Airbnb guests and hosts’ perceived risks of the crisis, enhance their mutual trusts and trust towards the platform which finally increase their satisfaction and loyalty in the setting of COVID-19 or similar crises in future.A investigação sobre a perceção e a intenção comportamental dos consumidores e dos fornecedores de alojamento através do Airbnb tem vindo a receber uma acrescida atenção dos académicos na literatura da economia colaborativa, na última década. Apesar do crescente interesse no estudo do efeito do “boca a boca” online (eWOM) na perceção dos clientes do Airbnb e nas suas intenções comportamentais através de técnicas de mineração de avaliações online, a literatura com enfoque nos consumidores revela que ainda são limitados os estudos relacionados com o Airbnb, sobretudo estudos empíricos que forneçam informação sobre como os clientes do Airbnb com diferentes características pessoais adotam o eWOM e quais são as motivações para a sua intenção de divulgarem um “boca a boca” (WOM) positivo após a experiência de estadia. Além disso, é importante notar que este estudo coincidiu com o período da pandemia global de COVID-19 – a qual impactou seriamente esta plataforma de aluguer de alojamento de curta duração, pelo que pouco se sabe sobre o processo de adoção do eWOM dos clientes do Airbnb e acerca do processo de tomada de decisão dos anfitriões do Airbnb no contexto de uma crise de saúde pública. Há ainda a salientar que a grande parte dos estudos existentes se concentra nos mercados do Airbnb maduros, nos quais fatores culturais e de contexto têm uma grande importância na influência da perceção das partes interessadas do Airbnb e dos seus comportamentos subsequentes. Assim, este estudo tem como objetivo explorar a perceção e as intenções comportamentais relacionadas com o eWOM dos consumidores do Airbnb; e estudar os antecedentes da intenção dos anfitriões do Airbnb continuarem na plataforma de partilha num mercado emergente de economia colaborativa – o Vietname, nomeadamente no cenário da pandemia global.
Guiada pelo paradigma positivista, esta investigação resulta de uma combinação de quatro artigos científicos que procuram alcançar os objetivos gerais acima mencionados. Mais especificamente, o primeiro artigo deste estudo utiliza o modelo Cognitive Appraisal – Emotional Response – Coping Behavior para reexaminar os antecedentes mais comumente confirmados como valores percecionados dos consumidores em relação ao Airbnb e ampliar a compreensão de como esses valores influenciam a satisfação e a intenção “boca a boca” online e tradicional ((e)WOM) dos consumidores vietnamitas do Airbnb. Os resultados confirmaram o papel significativo dos benefícios funcionais, dos valores monetários e dos benefícios hedónicos percecionados em encorajarem diretamente a intenção de um (e)WOM positivo dos consumidores do Airbnb, ou indiretamente através da satisfação com a sua experiência de estadia. Os resultados também mostraram que as relações entre interação social, novidade, sustentabilidade e a satisfação do cliente não são significativas no mercado vietnamita do Airbnb. Esses resultados contraditórios fornecem evidências mais fortes sobre a influência crítica dos valores culturais na perceção e nas intenções comportamentais dos clientes do Airbnb. Além disso, a novidade deste estudo reside na confirmação do impacto da intenção do WOM na intenção do eWOM na perspetiva dos comunicadores de mensagens, o qual é um resultado que ainda não foi discutido até agora em nenhum contexto de pesquisa.
Em segundo lugar, através da extensão do modelo Stimuli – Organism – Response, o próximo artigo desta investigação expande a nossa compreensão acerca dos determinantes da lealdade dos clientes do Airbnb, para além da bem conhecida contribuição da satisfação do cliente, uma vez que identificou o papel determinante do prazer percecionado dos clientes do Airbnb na sua intenção de espalharem comentários positivos sobre esta plataforma de partilha de alojamento. Além disso, a contribuição teórica deste estudo está também relacionada com a investigação do papel moderador das características sociodemográficas e tripografias dos clientes do Airbnb na associação entre o prazer percecionado, os seus antecedentes (benefícios da casa, interação social, autenticidade e valor monetário) e as suas consequências (intenção do eWOM). Os resultados revelaram que essas relações permanecem inalteradas entre os diferentes grupos de clientes, exceto nos turistas de negócios, os quais oferecem uma base para a compreensão empírica deste segmento de mercado emergente do Airbnb. Para atingir os objetivos da investigação nos dois primeiros estudos, foi aplicado um inquérito eletrónico por questionário, usando um método de amostragem não probabilístico, para recolher dados de uma amostra de clientes vietnamitas que haviam experimentado um alojamento reservado através do Airbnb no período de até um ano antes do momento de recolha de dados. Foi observada uma amostra de 352 indivíduos, dos quais 163 eram utilizadores elegíveis para o estudo, os quais foram retidos para a análise de dados. A análise de dados foi realizada através da aplicação do Modelo de Equações Estruturais de Mínimos Quadrados Parciais (PLS-SEM).
A terceira parte desta investigação, guiada pela evidência da literatura que os clientes adotam o eWOM de forma distinta, pretende fornecer uma evidência empírica para explicar as descobertas contraditórias sobre o efeito do eWOM nas intenções comportamentais dos consumidores do Airbnb, considerando o papel moderador da sensação de poder e risco psicológico percecionado pelos consumidores em relação ao COVID-19. Além disso, este trabalho também tem em consideração a importância das diferenças culturais nas intenções comportamentais dos clientes do Airbnb, através da realização de um estudo transnacional em Itália, Portugal e Vietname. Mais especificamente, este estudo expandiu o Model of Goal directed Behavior (MGB) para investigar como o eWOM influencia o desejo dos clientes, atuais e potenciais do Airbnb, em reservarem alojamentos através do Airbnb, de forma indireta através da atitude, das normas subjetivas, do controlo comportamental percecionado, das emoções antecipadas e da confiança nos anfitriões que, consequentemente, levam à sua intenção de compra. Para testar as hipóteses propostas, foi realizado um inquérito eletrónico por questionário nesses três países, no qual foi observada uma amostra total de 1.849 respondentes (incluindo 1.146 italianos, 262 portugueses e 441 vietnamitas utilizadores e não utilizadores do Airbnb). Os não utilizadores do Airbnb são definidos como os indivíduos que conhecem a plataforma do Airbnb, mas nunca a experimentaram. Os dados recolhidos foram posteriormente analisados também pelo PLS-SEM. Os resultados revelaram a existência de um papel moderador diferente segundo a sensação de poder e de risco psicológico no processo de adoção do eWOM dos clientes do Airbnb nesses três contextos de pesquisa, o que confirmou a importância dos fatores culturais e de contexto no estudo do eWOM e das intenções comportamentais dos clientes do Airbnb. Além disso, o desejo de reservar alojamento partilhado foi identificado como sendo o fator mais influente na intenção de compra dos clientes, o que confirmou a adequação do MGB em estudar as intenções comportamentais dos clientes do Airbnb.
Em quarto lugar, a parte final desta investigação muda o foco para o fornecedor de serviços de alojamento através do Airbnb – anfitriões do Airbnb, com o objetivo de investigar os antecedentes da sua intenção de continuarem na plataforma durante a pandemia de COVID-19. Os anfitriões do Airbnb são geralmente considerados como microempreendedores que não são formados profissionalmente em gestão de alojamentos. Com base na Theory of Planned Behavior (TPB), este estudo propõe uma estrutura concetual que integra os construtos da TPB, incluindo a atitude dos anfitriões do Airbnb, as normas subjetivas e o controlo comportamental percecionado, e um fator baseado em dedicação, denominado confiança em relação ao Airbnb, para estudar a sua intenção de lealdade com o efeito moderador do selo Superhost nos relacionamentos modelados. Uma amostra de 160 anfitriões vietnamitas do Airbnb foi observada através de um inquérito eletrónico por questionário e os dados foram posteriormente analisados através do PLS-SEM. Os resultados mostraram que a atitude dos anfitriões do Airbnb, o controlo comportamental percecionado e a confiança em relação ao Airbnb influenciam significativamente a sua intenção de continuarem a alugar os seus alojamentos na plataforma. Por último, mas não menos importante, os resultados confirmaram a existência do papel moderador do estatuto dos anfitriões do Airbnb no seu processo de tomada de decisão durante uma pandemia sem precedentes. Assim, este estudo também enriquece a literatura acerca da indústria de partilha de alojamento sob a ótica de diferentes tipos de prestadores de serviços de alojamento e contribui para o avanço da teoria no campo da resposta dos microempresários a crises.
Este estudo também fornece implicações práticas em duas vertentes específicas. Em primeiro lugar, os resultados deste estudo abrem novos caminhos na gestão da plataforma Airbnb, tendo em consideração a compreensão dos fornecedores de serviços de alojamento sobre os valores percecionados dos clientes vietnamitas do Airbnb, a sua percepção em relação ao alojamento partilhado e subsequentes intenções comportamentais relacionadas com o eWOM. Em segundo lugar, esses resultados contribuem também para apoiarem a empresa de gestão da plataforma e as autoridades locais na definição de estratégias de gestão eficazes para reduzir os riscos de crise percecionados pelos hóspedes e anfitriões do Airbnb, aumentando a sua confiança mútua e a confiança em relação à plataforma, o que, por sua vez, aumentará a sua satisfação e lealdade no cenário de COVID-19 ou em crises semelhantes no futuro
Argyreia gyrobracteata Traiperm & Chitchak (Convolvulaceae): a new record to the flora of Vietnam
No full textArgyreia gyrobracteata Traiperm & Chitchak (Convolvulaceae) is newly recorded in Vietnam. It is similar to A. mekongensis Gagnep & Courch in having a white campanulate corolla but differs from that species by having whitish surface of the abaxial leaf, narrowly lanceolate or linear-oblong, curly, rolled up the bract with a longer length of the petiole and a shorter pedicel. It was previously known only in Thailand, but was recently found in Lam Dong Province, Vietnam, for the first time. The present study provides a detailed description, colorful photos and the distribution of the species. Furthermore, a comparison of the diagnostic characters between this species and a related species in Vietnam, A. mekongensis Gagnep & Courch, is provided.
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