Browsing by Issue Date, starting with "2012-07"
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- The Satisfaction of the Nordic tourist with the Azores as a destinationPublication . Vieira, José Cabral; Couto, Gualter; Pimentel, Pedro; Menezes, António Gomes de; Moniz, Ana Isabel Arruda; Sousa, FábioTourism is considered a strategic economic sector for the outermost regions of Europe. In the Azores, Tourism is a dynamic and growing activity. New segments have emerged, such as ecological and sustainable tourism, nautical tourism and wildlife tourism. Currently, new niches are being developed around sports (surf, paragliding and diving are recent examples), religion, nature, healthcare and wellbeing. The latest products and services serve as alternatives or complements to the more traditional venues of hotels and restaurants. The latter have managed to continuously upgrade their standing in global markets via large investments in modernization, innovation and employee training. Progressively, the Azores are becoming a desirable destination to inhabitants of modern and stressful urban areas of Europe and North-America. Specifically, Northern European markets are considered strategic for the region. The typical Nordic Tourist seeks products and services easily found in the Azorean touristic market. Also, visitor inflows from Northern Europe can mitigate the effects of seasonality, a phenomenon still very visible in the region’s sector. Because tourism is a very competitive business worldwide, it is crucial to employ policies that enhance competitiveness. It is reasonable to argue that these policies should be guided by accurate knowledge of the strong and weak characteristics of the Azores, as a destination competing in a global market. Under this context, this paper seeks to comprehend how the typical Nordic visitor feels pleased with his stay in the Azores. Using a large database of responses from tourists, we employ econometric methods to assess the degree of satisfaction of the average Nordic visitor with the Azores as a destination.
- New xanthenodione: synthesis and antioxidant activity evaluationPublication . Leal, Stephanie B.; Pinto, Diana C. G. A.; Seca, Ana M. L.; Silva, Artur M. S.; Cavaleiro, José A. S.Due to the continuing interest of the research group in the synthesis of novel oxygen heterocycles we have recently developed a unique synthetic route towards new xanthenodiones 5 (scheme 1).[6] The application of this methodology in the cyclization of chromone derivatives 4b,c bearing methoxyl groups not only promote the cyclization to xanthenedione derivatives but also promote the demethylation leading to the 4-(benzylidene)-8-hydroxy-3-phenyl-3,4-dihydro-1H-xanthene-1,9(2H)-diones 5b,c . This interesting result prompted us to investigate the antioxidant potential of 4-(benzylidene)-8-hydroxy-3-phenyl-3,4-dihydro-1H-xanthene-1,9(2H)-diones 5a-c .
- Clustering of Symbolic Data based on Affinity Coefficient: Application to real data setsPublication . Sousa, Áurea; Bacelar-Nicolau, Helena; Nicolau, Fernando C.; Silva, OsvaldoThe increasing use of databases, often large ones, in diverse areas of study makes it pertinent to summarise data in terms of their most relevant concepts. These concepts may be described by types of complex data, also known as symbolic data […]. We present some results from the Ascendant Hierarchical Cluster Analysis (AHCA) of symbolic objects described by interval data, in order to illustrate the effectiveness of the Ascendent Hierarchical Cluster Analysis based on the weighted generalized affinity coefficient, for symbolic data. The measure of comparison between the elements was combined with classical aggregation criteria and probabilistic ones. The probabilistic aggregation criteria used in this study belong to a parametric family of methods in the scope of the probabilistic approach of AHCA, named VL methodology and the validation of the clustering results is based on some validation measures. Finally, we compare the results achieved by our approach with the ones obtained by other authors.
- Análise Classificatória de Dados de Natureza Complexa: Uma aplicação do Coeficiente de AfinidadePublication . Sousa, Áurea; Bacelar-Nicolau, Helena; Nicolau, Fernando C.; Silva, OsvaldoA Análise de Dados Simbólicos (ADS) é um domínio recente na área da descoberta do conhecimento e da gestão de dados. O seu primeiro passo consiste na extracção de informações úteis a partir de bases de dados de elevada dimensão, como em Data Mining, de modo a sumariar esses dados em termos dos seus conceitos mais relevantes. O segundo passo em ADS é aplicar novas ferramentas às informações extraídas, visando estender o Data Mining ao Knowledge Mining.O coeficiente de afinidade generalizado ponderado é uma medida de semelhança apropriada à Análise Classificatória (Cluster Analysis) de dados de natureza complexa (dados simbólicos), mesmo no caso de dados heterogéneos e de elevada dimensão. Neste trabalho, é dada uma atenção especial às medidas de proximidade entre objectos simbólicos, entre as quais o coeficiente de afinidade generalizado ponderado. É ilustrada a aplicação da Análise Classificatória Hierárquica Ascendente (ACHA) a dados de natureza complexa, retirados da literatura, com base no coeficiente de afinidade generalizado ponderado e em critérios de agregação clássicos e probabilísticos, estes últimos no âmbito da metodologia VL. Os resultados obtidos são comparados com os de outros autores.
- Purification and structural characterization of compounds isolated from Cystoseira abies-marinaPublication . Gouveia, Vera L. M.; Seca, Ana M. L.; Barreto, Maria do Carmo; Silva, Artur M. S.; Kijjoa, AnakeAlthough the Azores archipelago is rich in algal communities, only two papers have been published concerning the nutritional and pharmacological potential of this resource in the Azorean sea.[4,5,6] As a brown alga Cystoseira abies-marina grows abundantly in the coast of these islands and has a great resistance to predation, which indicates the presence of potential active compounds[7], we have investigated its secondary metabolites. We report herein isolation and structure elucidation of several compounds from Cystoseira abies-marina, collected at Mosteiros S. Miguel. The structures of the compounds were established by 1D (1H, 13C, DEPTs) and 2D (COSY, HSQC HMBC, NOESY) NMR techniques as well as HRMS.
- Global approach for the comparison of Clustering ResultsPublication . Silva, Osvaldo; Bacelar-Nicolau, Helena; Nicolau, Fernando C.The extraction of useful knowledge from a Hierarchical Cluster Analysis (HCA) is a complex process which depends on many factors, such as the applied clustering algorithms and the strategies developed in the initial stage of the HCA. We present a global approach for evaluating the quality of clustering results based on the comparison of partitions from the different clustering algorithms using the most relevant information available (e.g. stability, isolation and homogeneity of the clusters). In addition, we suggest a visual method to facilitate the evaluation of the quality of the partitions that allows us a quick perception of the similarities and the differences between the partitions, including the behaviour of the elements in the partitions. We illustrate our approach using a real data set (horse data). We applied HCA based on the weighted generalized affinity coefficient (similarity coefficient) to the case of complex data (symbolic data), combined with 26 clustering (classic and probabilistic) algorithms. Finally, we discuss the obtained results and the contribution of this approach to a better knowledge on the cluster structure of a data set.
- Comparação de pares de partições em Análise ClassificatóriaPublication . Silva, Osvaldo; Bacelar-Nicolau, Helena; Nicolau, Fernando C.; Sousa, ÁureaExistem diversos índices para a comparação de partições, o que dificulta a tomada de decisão, dado que cada um desses índices põe em evidência uma determinada peculiaridade das partições a comparar. Com o intuito de auxiliar nessa avaliação, é apresentada e exemplificada uma abordagem para a comparação de partições, com base na semelhança VL (Validade da Ligação), a qual tem, entre outras, a vantagem de uniformizar a escala de medida. Por último, serão tecidas algumas considerações sobre os resultados obtidos usando as abordagens clássicas e a abordagem VL.
- Diversidade do complexo Laurencia (Ceramiales. Rhodophyta) no Atlântico Tropical e Subtropical baseado em "DNA barcoding" e inferências filogenéticas.Publication . Garcia, Ana Carolina; Oliveira, Mariana C.; Fujii, Mutue T.; Machín-Sánchez, María; Neto, Ana I.; Gil-Rodríguez, María C.; Sentíes, Abel; Díaz-Larrea, Jhoana; Cassano, Valéria
- (Re)viver as brincadeiras e jogos de infância: o contributo para uma aprendizagem ao longo da vidaPublication . Condessa, IsabelPretende-se perceber a relevância dada pelo idoso açoriano às brincadeiras da sua infância, partindo-se do pressuposto de que estas atividades lúdicas além de proporcionarem a preservação da cultura de uma região, acabam por ser um recurso essencial na educação de qualquer indivíduo em sociedade. A partir das recordações de infância, evocadas num vasto grupo de idosos (mais de meio milhar) pertencentes a todo o arquipélago dos Açores, traçaremos algumas das vivências e crenças relacionadas com as suas brincadeiras de infância. Esta análise será realizada partindo da suposição de que nas brincadeiras de infância, que incidem em atividades e saberes populares, se reúne todo um universo de “saber-fazer” que envolve o desenvolvimento das capacidades individuais (físicas, motoras, cognitivas e socio afetivas de qualquer indivíduo.Realçamos ainda neste trabalho a interação possível de se estabelecer entre idosos e crianças – avós e netos – em experiência gratificantes que podem interceder para a melhoria da aprendizagem ao longo da vida.
- Some aromatic compounds from dichloromethane extract of Salicornia ramosissima.Publication . Isca, Vera M. S.; Seca, Ana M. L.; Pinto, Diana C. G. A.; Silva, Artur M. S.; Silva, HelenaSalicornia ramosissima J. Woods, is an annual halophyte, confined to saline habitats, widely distributed in the salt marsh of Ria de Aveiro (Portugal) and also present in many salt marshes of the Iberian Peninsula. Our interest in the phytochemical study of this specie, which belongs to the genus Salicornia and family Chenopodiaceae, is based on previous knowledge that plants of this genus presented compounds such as flavonoids, chromones and alkaloids which are well-recognized for their biological activities. Salicornia ramosissima was subject to some studies of growth conditions and salinity, but its phytochemical composition remains unknown. The analysis of the dichloromethane extract from S. ramosissima aerial parts allowed the isolation of some aromatic compounds, from which we present here their unequivocal structure elucidation.