Discrete-Time Fractional Variational Problems

We introduce a discrete-time fractional calculus of variations on the time scale $h\mathbb{Z}$, $h > 0$. First and second order necessary optimality conditions are established. Examples illustrating the use of the new Euler-Lagrange and Legendre type conditions are given. They show that solutions to the considered fractional problems become the classical discrete-time solutions when the fractional order of the discrete-derivatives are integer values, and that they converge to the fractional continuous-time solutions when $h$ tends to zero. Our Legendre type condition is useful to eliminate false candidates identified via the Euler-Lagrange fractional equation.Comment: Submitted 24/Nov/2009; Revised 16/Mar/2010; Accepted 3/May/2010; for publication in Signal Processing

Blink : observing thin slices of behavior to determine users' expectation towards task difficulty

This work aims to address the following question: is it possible to infer the users' expectations regarding task difficulty by watching them just before the actual start? We present a study where people acting as evaluators determined users’ expectations based on non-linguistic social signals in a 20 seconds video clip. The evaluations were performed using a five-point scale and the average error of the evaluations was of one point. Preliminary results suggest what type of signals was used by the evaluators to determine the users’ expected difficulty with the task.Este trabalho é financiado por Fundos FEDER através do Programa Operacional Factores de Competitividade – COMPETE e por Fundos Nacionais através da FCT – Fundação para a Ciência e a Tecnologia no âmbito do projecto PTDC/EIA-EIA/098634/200

Thin slices of interaction : predicting users’ task difficulty within 60 sec

We report on an exploratory study where the first 60 seconds of the video recording of a user interaction are used to predict the user’s experienced task difficulty. This approach builds on previous work on “thin slices” of human-human behavior, and applies it to humancomputer interaction. In the scenario of interacting with a photocopy machine, automated video coding showed that the Activity and Emphasis predicted 46.6% of the variance of task difficulty. This result closely follows reported results on predicting negotiation outcomes from conversational dynamics using similar variables on the speech signal.The project is funded by FEDER (Fundo Europeu de Desenvolvimento Regional) through COMPETE (Programa Operacional Factores de Competitividade) and by National funds through FCT (Fundação para a Ciência e a Tecnologia) in the context of the project PTDC/EIA-EIA/098634/2008

Marketing familiar: o marketing aplicado à gestão familiar

Este projeto descreve a discussão conceptual da filosofia de marketing aplicada à gestão familiar. Pretendeu-se com isto mostrar como o marketing pode ser aplicado como filosofia de gestão à família, conduzindo à concretização dos objetivos educacionais de uma forma mais pragmática e na linha da perspetiva mais atual de marketing que defende a definição de valores e ética como a condição para a sustentabilidade duma organização que na nossa perspetiva pode ser a familiar. Nesse sentido procedeu-se à aplicação do planeamento estratégico de marketing, ferramenta fundamental na operacionalização nesta filosofia de gestão, onde foram definidas as estratégias de marketing passíveis de serem seguidas pelas famílias, nomeadamente a religiosa, a tribal, a da natureza e a cívica, e à definição do marketing operacional assente nos “4 E”, que são “Experience” (Experiência), “Exchange” (Troca), “Everyplace” (Em todo lugar) e “Evangelism” (Evangelizar

A multivariate randomized controlled experiment about the effects of mindfulness priming on EEG neurofeedback self-regulation serious games

Neurofeedback training (NFT) is a technique often proposed to train brain activity SR with promising results. However, some criticism has been raised due to the lack of evaluation, reliability, and validation of its learning effects. The current work evaluates the hypothesis that SR learning may be improved by priming the subject before NFT with guided mindfulness meditation (MM). The proposed framework was tested in a two-way parallel-group randomized controlled intervention with a single session alpha NFT, in a simplistic serious game design. Sixty-two healthy naïve subjects, aged between 18 and 43 years, were divided into MM priming and no-priming groups. Although both the EG and CG successfully attained the up-regulation of alpha rhythms (F(1,59) = 20.67, p ηp2 = 0.26), the EG showed a significantly enhanced ability (t(29) = 4.38, p t(29) = 1.18, p > 0.1). Furthermore, EG superior performance on NFT seems to be explained by the subject’s lack of awareness at pre-intervention, less vigour at post-intervention, increased task engagement, and a relaxed non-judgemental attitude towards the NFT tasks. This study is a preliminary validation of the proposed assisted priming framework, advancing some implicit and explicit metrics about its efficacy on NFT performance, and a promising tool for improving naïve “users” self-regulation ability.This work is co-financed by the ERDF—European Regional Development Fund through the Operational Program for Competitiveness and Internationalisation—COMPETE 2020 (ref.: POCI01-0145-FEDER-007043; ref: POCI-01-0145-FEDER-007038), the North Portugal Regional Operational Program—NORTE 2020 (ref.: NORTE-01-0145-FEDER-000045) and by the Portuguese Foundation for Science and Technology – FCT under MIT Portugal (author Ph.D. grant ref.: PD/BD/114033/2015) and within the R&D Units Project Scope (ref.: UIDB/00319/2020)

Chlormequat selective electrodes: construction, evaluation and application at FIA systems

A flow injection analysis (FIA) system having a chlormequat selective electrode is proposed. Several electrodes with poly(vinyl chloride) based membranes were constructed for this purpose. Comparative characterization suggestedthe use of membrane with chlormequat tetraphenylborate and dibutylphthalate. On a single-line FIA set-up, operating with 1x10-2 mol L-1 ionic strength and 6.3 pH, calibration curves presented slopes of 53.6±0.4mV decade-1 within 5.0x10-6 and1.0x10-3 mol L-1, andsquaredcorrelation coefficients >0.9953. The detection limit was 2.2x10-6 mol L-1 and the repeatability equal to ±0.68mV (0.7%). A dual-channel FIA manifold was therefore constructed, enabling automatic attainment of previous ionic strength andpH conditions and thus eliminating sample preparation steps. Slopes of 45.5±0.2mV decade -1 along a concentration range of 8.0x10-6 to 1.0x10-3 mol L-1 with a repeatability ±0.4mV (0.69%) were obtained. Analyses of real samples were performed, and recovery gave results ranging from 96.6 to 101.1%

The use of biomarkers to evaluate the toxicity of metaldehyde and methiocarb baits to the terrestrial isopod porcellionides pruinosus Brandt, 1833

Biochemical indicators (biomarkers) are known to provide early warning signs of environmental pollution or stress conditions to the organisms, by measuring cellular or molecular responses of the target organism to xenobiotic agents. In this study, the terrestrial isopod Porcellionides pruinosus was exposed to these two molluscicides and three different enzymes, glutathione Stransferase (GST), acetylcholinesterase (AChE) and catalase (CAT) were analyzed to evaluate the effects of the application of the two molluscicides in single exposures and binary mixtures tests. Results indicate that the carbamate methiocarb inhibited significantly AChE activity, but no effects were observed in CAT and GST levels. The exposure to the metaldehyde had no effects on AChE, but a decrease in the higher exposure period was observed in GST levels as well as a general increase in CAT activity. The combined exposure of the two molluscicides resulted in a general decrease in AChE and CAT activity, but no visible effects were observed in terms of GST. The use of several biomarkers was a suitable tool to understand the mode of action of these two molluscicides in this isopod species

Measuring evidence-based practice in physical therapy: a mix-methods study

Evidence-based practice (EBP) is considered the “holy grail” to manage patients by health practitioners (such as physical therapists). However, sometimes, patients are not treated with the best interventions for their condition. Although studies already explored the facilitators and barriers for this issue, they increase in the level of importance if the information gathered are context appropriated. As the profession is relatively new in Portugal, currently little is known about the implementation of EBP in Portuguese physical therapists context. So, the aim of this study is to know if the Portuguese physical therapists use an EBP, and collect and deeper understand the factors, barriers and facilitators associated with EBP. Methods: This study incorporated a mixed-methods design (quantitative and qualitative). In an attempt to ensure the correct population sample, a national professional association e-mail database and the e-mails of past students from national schools were requested. For the quantitative data it was choose an e-survey, adapted from the EBP: Beliefs, Attitudes, Knowledge, and Behaviors of Physical Therapists Portuguese version questionnaire, consisted of 55 close-ended questions. It was analyzed response frequencies and associations between variables with logistic regression analyses. For the qualitative data, it was choose to perform semi-structured interviews in purposefully selected physical therapists to include different sociodemographic factors (especially those found to be statistically significant in the logistic regression) and survey responses regarding the physical therapists’ beliefs, attitudes, knowledge, and behaviors. The interviews were performed in an online software, where only audio contact was performed. The audios were anonymized and verbatim transcribed, and the texts explored by the thematic approach. Results: From the 277 physical therapists that shown interest in participating in the study, 193 fully completed the questionnaire and, from those, 10 participated in the interviews. The Portuguese physical therapists reported positive beliefs, attitudes, knowledge, and behaviors regarding EBP. Among the physical therapists characteristics it seems that age (younger therapists), education (participating in continuing education courses; belonging to practice-orientated organizations; having a doctorate degree; pursuing a higher academic degree; and being a clinical instructor), and workplace (working for someone else account; and academic sector) are the main factors in the Portuguese EBP implementation. The Portuguese physical therapists, beyond the physical therapists individual characteristics and workplace, also stated that evidence, patients, clinical experience, schools, country and physical therapy characteristics, may behave as facilitators or barriers when performing an EBP.info:eu-repo/semantics/publishedVersio