The Behavioral Regulation in Exercise Questionnaire (BREQ-3) Portuguese-Version: Evidence of Reliability, Validity and Invariance Across Gender

This study has as prime objective to analyze the psychometric properties of the Behavioral Regulation Exercise Questionnaire (BREQ-3) in a sample of Portuguese exercisers and invariance across gender. Two independent samples (448 calibration; 374 validation), aged between 16 and 78 years (M = 40.29; SD = 16.24), of both gender, (495 female; 327 male) were enrolled in this study. The results show that the original model (six factors; 24 items) did not fit to the data in a satisfactory way (χ 2 = 977.49; df = 237; B-S p < 0.001; SRMR = 0.07; NNFI = 0.80; CFI = 0.83; RMSEA = 0.08; 90% CI = 0.08–0.09). After removing six items (one for each factor), the model (six factors; 18 items) adjustment improved in a satisfactory way in both samples: calibration (χ 2 = 331.86; df = 120; B-S p < 0.001; SRMR = 0.06; NNFI = 0.91; CFI = 0.93; RMSEA = 0.06; 90% CI 0.06–0.07) and validation (χ 2 = 254.08; df = 120; B-S p < 0.001; SRMR = 0.04; NNFI = 0.93; CFI = 0.95; RMSEA = 0.06; 90% CI = 0.05–0.06). Results also showed model invariance across gender (1CFI ≤ 0.01). The Portuguese version of BREQ-3 (six factors; 18 items) is a valid and reliable measurement instrument to measure behavior regulation underlying self-determination theory in the exercise domain. However, the evidence also indicated that additional studies are needed to address the fragilities of the original model (six factors; 24 items).info:eu-repo/semantics/publishedVersio

Microgravity’s effect on the skeletal muscle: muscular adaptations and therapeutic intervention

Introdução – O incremento do tempo de exposição à microgravidade origina um descondicionamento músculo-esquelético que precisa de ser prevenido através do treino. Objetivos – Identificar os padrões destas alterações e descrever os programas de treino em microgravidade e estratégias pós-exposição. Método – A pesquisa da revisão da literatura foi conduzida através da MEDLINE/PubMed e PEDro com as seguintes palavras--chave: “spaceflight rehabilitation”, “spaceflight muscle”, “microgravity muscle” e “bed rest muscle”, seguida de uma seleção dos artigos. Resultados – Os estudos encontrados apresentam uma resposta músculo-tendinosa diferencial sendo que o treino protege total ou parcialmente estas estruturas. Conclusão – O treino de resistance de intensidade elevada e baixas repetições associado a exercícios específicos é o mais adequado para responder ao descondicionamento. - ABSTRACT - Introduction – The increased microgravity exposition time raised the need for training programs to avoid muscle and tendinous deconditioning. Objectives – To identify the deconditioning patterns and to identify and describe the training programs used for its prevention during and after microgravity exposure. Methods – This literature review is based on a search conducted via MEDLINE/PubMed and PEDro using the following search words: “spaceflight rehabilitation”, “spaceflight muscle”, “microgravity muscle” and “bed rest muscle”. The search was followed by an article selection. Results – The studies reveal a differential exposure phenomenon for which the training programs reviewed are partly effective. Conclusion – According to the literature the high intensity low volume resistance programs with specific exercises are more appropriate to address the deconditioning problem

Motivational determinants of physical education grades and the intention to practice sport in the future

Self-Determination Theory (SDT) is amongst motivational frameworks the most popular and contemporary approach to human motivation, being applied in the last decades in several domains, including sport, exercise and physical education (PE). Additionally, Achievement Goal Theory (AGT) has presented evidence of how contextual factors may influence student's behavior in this particular context. The main purpose of this study was to analyze the motivational climate created by the teacher in the classroom, students' satisfaction of Basic Psychological Needs (BPN), and how their behavioral regulation could explain PE grades and intention to practice sports in the future.Funding: This project was supported by the National Funds through FCT – Portuguese Foundation for Science and Technology (UID/ DTP/04045/2013) – and the European Fund for Regional Development (FEDER) allocated by European Union through the COMPETE 2020 Programme (POCI-01-0145FEDER-006969) – Competitiveness and Internationalization (POCI).info:eu-repo/semantics/publishedVersio

The Impact of E-trading and retail investor behaviour

Dissertation presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Information Systems and Technologies ManagementHuman behaviour is always a complicated subject of study but is one of the most wanted in many related areas, such as finance. Behavioural finance studies have been booming over the last years once scientists and organizations try to understand the causes and effects that lead to a particular action. This is in line with the general information on areas related to finance (e.g. Investments, personal finance, decision and control, among others. With this rapid spread of information, social interaction is more than ever an exciting topic to consider once the financial decision can help us predict behaviour. During the pandemic, many people worldwide were in lockdown, which drew their attention to finance investments. Cases like the Game stock and Reddit users show that retail investors can move prices up and down the market enough to create a loss for great corporations and financial institutions. This type of social behaviour shows how important it is to understand what drives human behaviour in finance to avoid a crash in the market system. This study uses the validation and expansion of the technology acceptance model (TAM) on social interaction in trading and investment applications and tries to predict if people are being influenced when or to use this kind of application. To achieve this mark, we collected 233 responses using Qualtrics and then indicated that social interaction significantly affects user behavioural finance

Feedback enhanced Dyakonov-Shur instability in Graphene-FET

Graphene devices are known to have the potential to operate THz signals. In particular, graphene field-effect transistors have been proposed as devices to host plasmonic instabilities in the THz realm; for instance, Dyakonov-Shur instability which relies upon dc excitation. In this work, starting from a hydrodynamical description of the charge carriers, we extend the transmission line description of graphene field-effect transistors to a scheme with a positive feedback loop, also considering the effects of delay, which leads to the transcendental transfer function with terms of the form $e^{as}{\rm sech}^k(s)/s$. Applying the conditions for the excitation of Dyakonov-Shur instability, we report an enhanced voltage gain in the linear regime that is corroborated by our simulations of the nonlinear hydrodynamic model for the charge carriers. This translates to both greater saturation amplitude -- often up to 50% increase -- and fastest growth rate of the self-oscillations. Thus, we bring forth a prospective concept for the realization of a THz oscillator suitable for future plasmonic circuitry

Distribution patterns of deep-sea benthopelagic fish off Algarve coast, Portugal

The present study characterises and compares the structure and diversity of the deep-sea benthopelagic ichthyofauna off the southern Portuguese coast, according to the biomass values –in kg/(nautical mile)2– of ten teleost and seven chondrichthyan species. The differences between the biomass of benthopelagic species were assessed by depth interval and sampling season. It seems clear that even at 100 m depth intervals there are differences within the fish assemblages, and that a few species make most of the contribution to such differences. No traces of seasonality or even differences between the sampling years have been found. There is a separation between slope habitat