Browsing by Issue Date, starting with "2015-05-01"
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- Da distinção entre contitularidade de direitos e concorrência de direitosPublication . Sequeira, Elsa Vaz de
- Licitação internacional e empresa estrangeira: os cenários brasileiro e europeuPublication . Moreira, Egon Bockmann; Guimarães, Bernardo Strobel; Torgal, LinoO presente artigo pretende discutir o regime de participação de empresas estrangeiras nas licitações no Brasil e traçar um comparativo com o panorama equivalente na União Europeia.
- Relação entre pares e género: contributos da adaptação do Peer Relations Questionnaire junto de adolescentes portuguesesPublication . Dias, Paulo C.; Cadime, Irene; Castillo, José A. García delA compreensão das diferenças de género nos comportamentos ajustados ou pró-sociais e nas relações de violência entre os pares, seja na perspetiva do perpetrador ou da vítima, é essencial para a educação. Com o conhecimento destes fenómenos podemos reconhecer sinais e comportamentos, mas também ajustar a intervenção psicoeducativa, de forma a promover o desenvolvimento integral de todos os alunos. Por conseguinte, este trabalho centra-se em dois objectivos: avaliar as propriedades psicométricas do Peer Relations Questionnaire na população Portuguesa e, partindo dos resultados obtidos no mesmo, explorar as relações entre pares em função do género. Para isso, foram realizados dois estudos junto de duas amostras, com 304 e 712 adolescentes, com idades compreendidas entre os 11 e os 16 anos. Os resultados forneceram evidência de validade e fidelidade para o instrumento. Resultados de estudos diferenciais e de associação apontaram ainda diferenças significativas na relação entre pares em função do género, com os rapazes a apresentarem maior nível de violência em relação aos pares, mas também a relatarem ser mais vítimas dessa violência, comparativamente com as raparigas. Inversamente, as raparigas parecem exibir maiores níveis de comportamento pró-social. Encontrou-se ainda uma relação negativa entre violência e idade, assim como com a escolaridade do pai. Estes resultados são discutidos neste artigo à luz da literatura existente, apresentando-se também as suas implicações para a investigação e intervenção
- Natural extracts into chitosan nanocarriers for rosmarinic acid drug deliveryPublication . Silva, Sara Baptista da; Amorim, Manuela; Fonte, Pedro; Madureira, Raquel; Ferreira, Domingos; Pintado, Manuela; Sarmento, BrunoContext: Nanotechnology can be applied to deliver and protect antioxidants in order to control the oxidative stress phenomena in several chronic pathologies. Chitosan (CS) nanoparticles are biodegradable carriers that may protect antioxidants with potent biological activity such as rosmarinic acid (RA) in Salvia officinalis (sage) and Satureja montana (savory) extracts for safe and innovative therapies. Objective: Development and characterization of CS nanoparticles as a stable and protective vehicle to deliver RA for medical applications using natural extracts as sage and savory. Materials and methods: Antioxidant-CS based nanoparticles were prepared by ionic gelation with sodium tripolyphosphate (TPP), at pH 5.8 with a mass ratio of 7:1 (CS:TPP), with a theoretical antioxidant-CS loading of 40-50%. The nanoparticles were then characterized by different methods such as photon correlation spectroscopy, laser Doppler anemometry, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR), high-performance liquid chromatographic (HPLC), association efficiency, and antioxidant activity. Results and discussion: Individual and small sizing nanoparticles, around 300 nm, were obtained. SEM confirmed smooth and spherical nanoparticles after freeze-drying. No chemical interactions were found between antioxidants and CS, after encapsulation, by DSC and FTIR. The association efficiency was 51.2% for RA (with 40% loading) and 96.1 and 98.2% for sage and savory nanoparticles, respectively (both with 50% loading). Antioxidant activity values were higher than 0.0348 eq [Asc. Ac.] g/L/g extract and 0.4251 μmol/eq Trolox/g extract. Conclusion: The extracts under study are promising vehicles for RA drug delivery in CS nanocarriers.
- Impacts of hedonic and utilitarian user motives on the innovativeness of user-developed solutionsPublication . Stock, Ruth Maria; Oliveira, Pedro; Hippe, Eric vonWhen individual consumers develop products for their own use, they in part expect to be rewarded by the use value of what they are creating (utilitarian user motives), and in part expect to be rewarded intrinsically by such things as the fun and learning experience derived from creating it (hedonic user motives). This paper shows a first-of-type study to understand the relationship between individual consumers' motives to innovate and the novelty and utility of the solutions they develop. The theoretical framework integrates self-determination theory and goal-setting theory. The major findings of this study are that utilitarian user motives positively affect the utility of user-developed innovations. In contrast, hedonic user motives drive solution novelty; the more an innovator is "in it for fun," the more novel the solution developed. However, hedonic user motives also have an inverted U-shaped relationship with solution utility. When the dominant motive for developing an innovation is the joy of the creative process rather than use value, the utility of what is developed is negatively affected. These findings are of research interest, and can be of significant practical interest to producers hoping to benefit from user-developed innovations. For the first time, it has been possible to show that the adjustment of hedonic rewards, for example by means such as gamification, can affect the nature and utility of solutions individuals create.
- Oral and gastric helicobacter pylori: effects and associationsPublication . Veiga, Nélio; Pereira, Carlos; Resende, Carlos; Amaral, Odete; Ferreira, Manuela; Nelas, Paula; Chaves, Claudia; Duarte, João; Cirnes, Luis; Machado, José Carlos; Ferreira, Paula; Correia, Ilídio J.Introduction This study consisted in the comparison of the prevalence of Helicobacter pylori (H. pylori) present in the stomach and in saliva of a sample of Portuguese adolescents and the assessment of the association between H. pylori infection with socio-demographic variables and prevalence of dental caries. Materials and Methods A cross-sectional study was designed including a sample of 447 adolescents aged 12 to 19 years old, attending a public school in Sátão, Portugal. A questionnaire about socio-demographic variables and oral health behaviors was applied. Gastric H. pylori infection was determined using the urease breath test (UBT). Saliva collection was obtained and DNA was extracted by Polymerase Chain Reaction (PCR) in order to detect the presence of oral H. pylori. Results The prevalence of gastric H. pylori detected by UBT was 35.9%. Within the adolescents with a gastric UBT positive, only 1.9% were positive for oral H. pylori. The presence of gastric H. pylori was found to be associated with age (>15years, Odds ratio(OR)=1.64,95% CI=1.08-2.52), residence area (urban,OR=1.48,95%CI=1.03-2.29) and parents' professional situation (unemployed,OR=1.22,95%CI=1.02-1.23). Among those with detected dental caries during the intra-oral observation, 37.4% were positive for gastric H. pylori and 40.2% negative for the same bacterial strain (p=0.3). Conclusions The oral cavity cannot be considered a reservoir for infection of H. pylori. Gastric H. pylori infection was found to be associated with socio-demographic variables such as age, residence area and socioeconomic status.
- Intra and inter-individual differences in social intelligence of portuguese studentsPublication . Pinto, Joana Carneiro; Faria, Liliana; Gaspar, Neide; Taveira, Maria do CéuA inteligência social constitui uma condição favorável à tomada de decisão e ao desenvolvimento vocacional. Este trabalho visa caracterizar os níveis de inteligência social, e analisar as diferenças intra e interindividuais, em alunos portugueses em anos de pré-transição vocacional. Participaram 1095 alunos (552, 50% mulheres), com uma média de idades de 14,78 anos (DP = 1,86), do 8º, 10º, e 11º níveis escolares. Administrou-se a Prova Cognitiva de Inteligência Social (PCIS), em dois momentos (T1 e T2), com seis meses de intervalo. Os resultados indicam que o 8º ano obteve resultados médios superiores, nos índices de Resolução de Problemas, Motivação e Autoconfiança (T1), enquanto o 10º ano obteve resultados superiores, em Resolução de Problemas, Motivação e Familiaridade (T2). Entre momentos de avaliação, registra-se, para todos os níveis escolares, um aumento em Resolução de Problemas e Autoconfiança em situações sociais. Estes resultados constituem condições psicológicas favoráveis à promoção do questionamento ético nas intervenções de orientação vocacional.