Validação da versão portuguesa da Escala de Motivação Situacional (SIMS) em contextos académicos

The Situational Motivation Scale (SIMS), seeks to evaluate the motivation experienced when carrying out a specific task. The purpose of this research was to validate a Portuguese-language version of the scale, using a sample of 409 students, by attempting to reproduce its factor structure. The reliability analysis revealed acceptable internal consistency indexes in all subscales. Construct validity was assessed through Confirmatory Factor Analysis. The contributions of the factors and index of goodness-of-fit demonstrated the need to eliminate two items, which seems to agree with the results in other validation studies. Overall, results revealed that the SIMS is composed of four consistent factors and attested its psychometric quality. The scale does seem to represent a self-report measure of situational intrinsic motivation, identified regulation, external regulation, and amotivation, and can be widely used for the assessment of this construct in Portuguese academic contexts.A Escala de Motivação Situacional (sims) procura avaliar a motivação experimentada no desempenho de uma tarefa específica. O objetivo deste estudo foi validar a versão portuguesa, com uma amostra de 409 estudantes, ao tentar reproduzir a sua estrutura fatorial. Os resultados demostram uma consistência interna adequada relativamente às subescalas. A validade de constructo foi avaliada com a Análise Fatorial Confirmatória. Os valores de contribuição de cada fator e os índices de ajustamento assinalam a necessidade de eliminação de dois itens, que, por seu turno, vai de encontro a resultados de outros estudos de validação. Em geral, os resultados indicam que a sims é composta por quatro fatores consistentes e demostram a qualidade psicométrica. A escala parece ser uma boa medida de auto-relato para avaliar a motivação intrínseca, regulação identificada, regulação externa, e amotivação situacional, podendo ser utilizada na avaliação do constructo no contexto acadêmico português. Palavras-chave: autodeterminação, motivação situacional, medidas de motivação, alunos de ensino secundário, alunos universitários.Foundation for Science and Technology (FCT), Portuga

An alternative well-posedness property and static spacetimes with naked singularities

In the first part of this paper, we show that the Cauchy problem for wave propagation in some static spacetimes presenting a singular time-like boundary is well posed, if we only demand the waves to have finite energy, although no boundary condition is required. This feature does not come from essential self-adjointness, which is false in these cases, but from a different phenomenon that we call the alternative well-posedness property, whose origin is due to the degeneracy of the metric components near the boundary. Beyond these examples, in the second part, we characterize the type of degeneracy which leads to this phenomenon.Comment: 34 pages, 3 figures. Accepted for publication in Class. Quantum Gra

Exposição de pequenos animais à hiperoxia - um modelo para estudo do papel do músculo liso na hiperreactividade brônquica

ABSTRACTExposure of small animals to high oxygen concentrations can induce morphological and functional changes usually found in the airways of patients with bronchopulmonary dysplasia and asthma. This led to the use of animal models based on exposure to high concentrations of oxygen in order to study the relation between these airway changes and the development of hyperresponsiveness. During the last ten years several studies, using in vivo and in vitro techniques, have shown a close association between cholinergic responsiveness and airway wall remodeling in rats exposed to high levels of oxygen in the inspired air. However, the comparison and interpretation of the results obtained by the various groups is often a difficult task due to the methodological differences found between the protocols. The objective of this paper is to synthesize the information concerning the hyperoxia exposure techniques, the airway challenging agents used and their methods of administration and also the parameters used to measure the responses. It is also included a review of the criteria that determined the choice of particular animal species, the stage of development more often chosen to begin the hyperoxic exposure and also its biological effects on the structure and function of the airways. It is concluded conclude that the hyperoxic rat is a suitable model to evaluate the mechanisms involved in bronchial responsiveness, in particular the contribution of the qualitative and quantitative changes occurring in the airway smooth muscle.REV PORT PNEUMOL 2002; VIII (3): 223-23

Hábitos de Lectura y Consumo de libros en Colombia.

"El propósito de este capítulo es evaluar la situación de la lectura y la compra de libros en Colombia en 2005, de acuerdo con los resultados del módulo especial sobre hábitos de lectura de la Encuesta Continua de Hogares (ECH) del Departamento Administrativo Nacional de Estadística (DANE) aplicado en ese año".Hábitos de lectura, Libros, Consumo de libros, Economía de la Cultura, Compra de libros, Lectura en Internet, Colombia

Validação da versão portuguesa da Situational Motivation Scale (SIMS) em contextos académicos

A Escala da Motivação Situacional – SIMS (Guay, Vallerand & Blanchard, 2000), procura avaliar, de acordo com o modelo hierárquico da motivação intrínseca / extrínseca de Vallerand (1997), a motivação experimentada no decurso da realização de uma tarefa específica. Na presente comunicação pretendemos dar conta dos principais resultados do estudo de tradução e adaptação à população portuguesa da SIMS, junto de uma amostra de 312 estudantes do ensino superior. Globalmente, os resultados das análises psicométricas dos itens e das diferentes subescalas (amotivação, regulação externa, regulação identificada e motivação intrínseca) atestam a qualidade psicométrica da SIMS. No que se refere à validade de constructo (CFA), os contributos dos fatores e os índices de qualidade do ajustamento demostraram a necessidade de eliminação de dois itens, o que parece estar de acordo com os resultados encontrados em outros estudos de validação (e.g., Martín-Albo, Núñez & Navarro, 2009). Em síntese, os resultados obtidos parecem suportar a utilização da versão portuguesa da escala SIMS para avaliar a motivação situacional em contexto académico

Colombian vanilla and its microbiota. III. Diversity and structure of the endophytic community

Endophytic fungal communities are well-recognised entities within plants worldwide. They hold species with potential in medicinal affairs, biological control of pests, industry, and more. Nevertheless, ecological data about structure and dynamics of endophytic communities are scarce. In this study we sampled root, stem and leaf tissues of Colombian vanilla species in order of both, identifying endosymbionts and characterising the community they belong to. An interesting array of endophytic species was found, including taxa that function as pathogens, saprotrophs, and dermatophytes in other plants/scenarios. Ecological parameters show a moderate diversity with a lognormal arrangement of species quite similar to communities of macroorganisms. Many species here reported belong to taxa broadly reported as sources of biologically active compounds, so they are good candidates for bioprospecting research

Mitochondrial dysfunction and oxidative stress in patients with chronic kidney disease.

Mitochondria abnormalities in skeletal muscle may contribute to frailty and sarcopenia, commonly present in patients with chronic kidney disease (CKD). Dysfunctional mitochondria are also a major source of oxidative stress and may contribute to cardiovascular disease in CKD We tested the hypothesis that mitochondrial structure and function worsens with the severity of CKD Mitochondrial volume density, mitochondrial DNA (mtDNA) copy number, BNIP3, and PGC1α protein expression were evaluated in skeletal muscle biopsies obtained from 27 subjects (17 controls and 10 with CKD stage 5 on hemodialysis). We also measured mtDNA copy number in peripheral blood mononuclear cells (PBMCs), plasma isofurans, and plasma F2-isoprostanes in 208 subjects divided into three groups: non-CKD (eGFR>60 mL/min), CKD stage 3-4 (eGFR 60-15 mL/min), and CKD stage 5 (on hemodialysis). Muscle biopsies from patients with CKD stage 5 revealed lower mitochondrial volume density, lower mtDNA copy number, and higher BNIP3 content than controls. mtDNA copy number in PBMCs was decreased with increasing severity of CKD: non-CKD (6.48, 95% CI 4.49-8.46), CKD stage 3-4 (3.30, 95% CI 0.85-5.75, P = 0.048 vs. non-CKD), and CKD stage 5 (1.93, 95% CI 0.27-3.59, P = 0.001 vs. non-CKD). Isofurans were higher in patients with CKD stage 5 (median 59.21 pg/mL, IQR 41.76-95.36) compared to patients with non-CKD (median 49.95 pg/mL, IQR 27.88-83.46, P = 0.001), whereas F2-isoprostanes did not differ among groups. Severity of CKD is associated with mitochondrial dysfunction and markers of oxidative stress. Mitochondrial abnormalities, which are common in skeletal muscle from patients with CKD stage 5, may explain the muscle dysfunction associated with frailty and sarcopenia in CKD Further studies are required to evaluate mitochondrial function in vivo in patients with different CKD stages

Noncommutative Quantum Mechanics: The Two-Dimensional Central Field

Quantum mechanics in a noncommutative plane is considered. For a general two dimensional central field, we find that the theory can be perturbatively solved for large values of the noncommutative parameter ($\theta$) and explicit expressions for the eigenstates and eigenvalues are given. The Green function is explicitly obtained and we show that it can be expressed as an infinite series. For polynomial type potentials, we found a smooth limit for small values of $\theta$ and for non-polynomial ones this limit is necessarily abrupt. The Landau problem, as a limit case of a noncommutative system, is also considered.Comment: new references adde

Gaussian stationary processes over graphs, general frame and maximum likelihood identification

In this paper, using spectral theory of Hilbertian operators, we study ARMA Gaussian processes indexed by graphs. We extend Whittle maximum likelihood estimation of the parameters for the corresponding spectral density and show their asymptotic optimality

Suppress to forget: The effect of a mindfulness-based strategy during an emotional item-directed forgetting paradigm

Forgetting is a common phenomenon in everyday life. Although it often has negative connotations, forgetting is an important adaptive mechanism to avoid loading the memory storage with irrelevant information. A very important aspect of forgetting is its interaction with emotion. Affective events are often granted special and priority treatment over neutral ones with regards to memory storage. As a consequence, emotional information is more resistant to extinction than neutral information. It has been suggested that intentional forgetting serves as a mechanism to cope with unwanted or disruptive emotional memories and the main goal of this study was to assess forgetting of emotional auditory material using the item-method directed forgetting (DF) paradigm using a forgetting strategy based on mindfulness as a means to enhance DF. Contrary to our prediction, the mindfulness-based strategy not only did not improve DF but reduced it for neutral material. These results suggest that an interaction between processes such as response inhibition and attention is required for intentional forgetting to succeed