Physical activity in the school setting: cognitive performance is not affected by three different types of acute exercise

Recent studies indicate that a single bout of physical exercise can have immediatepositive effects on cognitive performance of children and adolescents. However, thetype of exercise that affects cognitive performance the most in young adolescents isnot fully understood. Therefore, this controlled study examined the acute effects ofthree types of 12-min classroom-based exercise sessions on information processingspeed and selective attention. The three conditions consisted of aerobic, coordination,and strength exercises, respectively. In particular, this study focused on the feasibilityand efficiency of introducing short bouts of exercise in the classroom. One hundredand ninety five students (5th and 6th grade; 10–13 years old) participated in a doublebaseline within-subjects design, with students acting as their own control. Exercise typewas randomly assigned to each class and acted as between-subject factor. Before andimmediately after both the control and the exercise session, students performed twocognitive tests that measured information processing speed (Letter Digit SubstitutionTest) and selective attention (d2 Test of Attention). The results revealed that exercisingat low to moderate intensity does not have an effect on the cognitive parameters testedin young adolescents. Furthermore, there were no differential effects of exercise type.The results of this study are discussed in terms of the caution which should be takenwhen conducting exercise sessions in a classroom setting aimed at improving cognitive performance.

Development of functionalised multiwalled carbon nanotube/polyaniline composites for electrical applications

Combining intrinsically conducting polymers with carbon nanotubes (CNT) helps in creating composites with superior electrical and thermal characteristics. These composites are capable of replacing metals and semiconductors as they possess unique combination of electrical conductivity, flexibility, stretchability, softness and bio-compatibility. Their potential for use in various organic devices such as super capacitors, printable conductors, optoelectronic devices, sensors, actuators, electrochemical devices, electromagnetic interference shielding, field effect transistors, LEDs, thermoelectrics etc. makes them excellent substitutes for present day semiconductors.However, many of these potential applications have not been fully exploited because of various open–ended challenges. Composites meant for use in organic devices require highly stable conductivity for the longevity of the devices. CNT when incorporated at specific proportions, and with special methods contributes quite positively to this end.The increasing demand for energy and depleting fossil fuel reserves has broadened the scope for research into alternative energy sources. A unique and efficient method for harnessing energy is thermoelectric energy conversion method. Here, heat is converted directly into electricity using a class of materials known as thermoelectric materials. Though polymers have low electrical conductivity and thermo power, their low thermal conductivity favours use as a thermoelectric material. The thermally disconnected, but electrically connected carrier pathways in CNT/Polymer composites can satisfy the so-called “phonon-glass/electron-crystal” property required for thermoelectric materials. Strain sensing is commonly used for monitoring in engineering, medicine, space or ocean research. Polymeric composites are ideal candidates for the manufacture of strain sensors. Conducting elastomeric composites containing CNT are widely used for this application. These CNT/Polymer composites offer resistance change over a large strain range due to the low Young‟s modulus and higher elasticity. They are also capable of covering surfaces with arbitrary curvatures.Due to the high operating frequency and bandwidth of electronic equipments electromagnetic interference (EMI) has attained the tag of an „environmental pollutant‟, affecting other electronic devices as well as living organisms. Among the EMI shielding materials, polymer composites based on carbon nanotubes show great promise. High strength and stiffness, extremely high aspect ratio, and good electrical conductivity of CNT make it a filler of choice for shielding applications. A method for better dispersion, orientation and connectivity of the CNT in polymer matrix is required to enhance conductivity and EMI shielding. This thesis presents a detailed study on the synthesis of functionalised multiwalled carbon nanotube/polyaniline composites and their application in electronic devices. The major areas focused include DC conductivity retention at high temperature, thermoelectric, strain sensing and electromagnetic interference shielding properties, thermogravimetric, dynamic mechanical and tensile analysis in addition to structural and morphological studies.

The Greek monetary system and its derivations over other ancient Mediterranean systems.

One of the main features of the Greek currency are the big differences between emissions of the polis, which did not match either in their iconographic message types, not even in the met-rical pattern of their values. These differences were reflected in exchange systems ruled by the main sanctuaries that shrines stipu-lated thus giving official status to change.

Atividade física em idosos: o que os mantém motivados?

Hoje em dia são muitos os idosos que participam em programas de atividade física. No entanto é frequente que as pessoas abandonem os programas e regressem a um estilo de vida sedentário. Um fator chave para evitar este abandono é manter os idosos motivados. Foi objetivo deste estudo compreender os fatores motivacionais que levam as pessoas a participar nestes programas de modo a poder melhorá-los. METODOLOGIA A amostra foi constituída por 21 idosos (63±5.34 years) participantes num programa de atividade física três vezes por semana. Foi utilizado o questionário EMI-2 para avaliar os fatores motivacionais. Foi efetuada a estatística descritiva para calcular as médias e desvios padrão dos resultados para cada questão e grupo de questões. RESULTADOS Os principais fatores motivacionais têm que ver com o bem-estar (4.50±0.02), prevenção de doenças (4.35±0.31) e a agilidade (4.3±0.20). Os fatores menos importantes são o reconhecimento social (0.88±0.09), competição (1.46±0.33) e problemas de saúde (1.62±0.36). CONCLUSÃO O bem-estar parece ser o fator principal e a competição o menos importante para a participação dos idosos nos programas de atividade física. Assim, devem ser promovidas metodologias de treino que promova melhorias cardiovasculares, de forma não competitiva, indo de encontro aos principais fatores motivacionais encontrados.

Motivação para a prática da modalidade de atletismo por parte dos atletas de diferentes regiões de Portugal

Dissertação apresentado à Escola Superior de Educação do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Atividade Física.

Tecido hepático e corpo adiposo de rã-touro (Lithobates catesbeianus) submetido a diferentes fotoperíodos

The study was conducted to evaluate the liver tissue weight, body fat weight, the fatty somatic index and the liver somatic index of bullfrogs subjected to three photoperiod during the growing phase (initial 30 days) and finishing (60 days). The treatments were 16 h light and 8 h dark, 12 h of light and dark and 8 h light and 16 h dark. The experimental design was completely randomized design with three replications. We used 36 bullfrogs/m2 weighing from 22 to 28 g. The results were submitted to ANOVA and Tukey Test at 5% probability. Differences were found for the weight of body fat, liver tissue weight, liver somatic index and fatty somatic index the bullfrog to the treatments and the study periods and there is greater accumulation of energy to ninety days. The photoperiod did not influence body weight and fat weight of the liver tissue of bullfrog at the end of the fattening period and the difference fatty somatic index and liver somatic index were influenced by body weight of animals.

Species composition and hybridisation of mussel species (Bivalvia: Mytilidae) in Australia

Mussels belonging to the Mytilus edulis species complex have been the focus of numerous studies exploring the systematics and origin of this commercially and ecologically important genus. Species have wide geographical ranges and hybridise where their distributions overlap, making identification difficult. Several molecular markers have been used to distinguish between the species within the M. edulis species complex; however, no single marker system has been found to be completely diagnostic, and a combination of markers are used. Here, we used a combination of three nuclear genes and a mitochondrial gene region to assess the species composition of Mytilus mussels collected across its geographical range in Australia. Our results show that the majority (98.5%) of individuals sampled from Australian populations are Mytilus galloprovincialis, with 56.2% of them displaying a southern hemisphere haplotype, 10.3% displaying a putatively northern hemisphere haplotype, and 32% having M. galloprovincialis genotypes consistent with either northern or southern hemisphere M. galloprovincialis lineages. The taxonomic origin of the remaining 1.5% of samples (n ¼ 3) could not be conclusively determined. Our results suggest that there have been significant introductions of non-native M. galloprovincialis lineages into both southern and northern hemisphere populations.

Development of Physics-based Models and Design Optimization of Power Electronic Conversion Systems

The main objective for physics based modeling of the power converter components is to design the whole converter with respect to physical and operational constraints. Therefore, all the elements and components of the energy conversion system are modeled numerically and combined together to achieve the whole system behavioral model. Previously proposed high frequency (HF) models of power converters are based on circuit models that are only related to the parasitic inner parameters of the power devices and the connections between the components. This dissertation aims to obtain appropriate physics-based models for power conversion systems, which not only can represent the steady state behavior of the components, but also can predict their high frequency characteristics. The developed physics-based model would represent the physical device with a high level of accuracy in predicting its operating condition. The proposed physics-based model enables us to accurately develop components such as; effective EMI filters, switching algorithms and circuit topologies [7]. One of the applications of the developed modeling technique is design of new sets of topologies for high-frequency, high efficiency converters for variable speed drives. The main advantage of the modeling method, presented in this dissertation, is the practical design of an inverter for high power applications with the ability to overcome the blocking voltage limitations of available power semiconductor devices. Another advantage is selection of the best matching topology with inherent reduction of switching losses which can be utilized to improve the overall efficiency. The physics-based modeling approach, in this dissertation, makes it possible to design any power electronic conversion system to meet electromagnetic standards and design constraints. This includes physical characteristics such as; decreasing the size and weight of the package, optimized interactions with the neighboring components and higher power density. In addition, the electromagnetic behaviors and signatures can be evaluated including the study of conducted and radiated EMI interactions in addition to the design of attenuation measures and enclosures.

Physics-Based Modeling of Power System Components for the Evaluation of Low-Frequency Radiated Electromagnetic Fields

The low-frequency electromagnetic compatibility (EMC) is an increasingly important aspect in the design of practical systems to ensure the functional safety and reliability of complex products. The opportunities for using numerical techniques to predict and analyze system’s EMC are therefore of considerable interest in many industries. As the first phase of study, a proper model, including all the details of the component, was required. Therefore, the advances in EMC modeling were studied with classifying analytical and numerical models. The selected model was finite element (FE) modeling, coupled with the distributed network method, to generate the model of the converter’s components and obtain the frequency behavioral model of the converter. The method has the ability to reveal the behavior of parasitic elements and higher resonances, which have critical impacts in studying EMI problems. For the EMC and signature studies of the machine drives, the equivalent source modeling was studied. Considering the details of the multi-machine environment, including actual models, some innovation in equivalent source modeling was performed to decrease the simulation time dramatically. Several models were designed in this study and the voltage current cube model and wire model have the best result. The GA-based PSO method is used as the optimization process. Superposition and suppression of the fields in coupling the components were also studied and verified. The simulation time of the equivalent model is 80-100 times lower than the detailed model. All tests were verified experimentally. As the application of EMC and signature study, the fault diagnosis and condition monitoring of an induction motor drive was developed using radiated fields. In addition to experimental tests, the 3DFE analysis was coupled with circuit-based software to implement the incipient fault cases. The identification was implemented using ANN for seventy various faulty cases. The simulation results were verified experimentally. Finally, the identification of the types of power components were implemented. The results show that it is possible to identify the type of components, as well as the faulty components, by comparing the amplitudes of their stray field harmonics. The identification using the stray fields is nondestructive and can be used for the setups that cannot go offline and be dismantled

Student’s Perceptions of the Community Impact of Social Education Degree Internship

Evaluating the impact of an intervention is a very important stage in social educators’ practice, since it allows them to improve the quality of socio-educational projects. The aim of this study is to rethink the internship of the social education degree through students’ perceptions about the impact of their projects in the community. This is a qualitative and exploratory study using documental analysis of 50 internship final reports of a social education degree from a Portuguese polytechnic higher education institution and whose emerging categorical content analysis was performed with NVivo software. The analysis revealed four distinct indicators linked to the project (accomplished objectives, evaluation of activities, sustainability and innovation), the target group (participation, motivation and benefits), the institution (satisfaction of collaborators, improved dynamic, routines and space enhancements), and the students (relational, reflexive and planning skills; satisfaction). It also revealed instruments, feedback, observation, document analysis and case reports as means of verification. The use of indicators related to the project’s objectives, the changes perceived from the benefits in the target-group and in the institution, and the interveners’ level of satisfaction should be noted as positive. Given the inconsistency in the use of formal assessment instruments, the results show the need to strengthen students’ mobilisation of project assessment skills in order to improve the quality of undergraduate education.

Undergraduate Social Education Student’s Perspectives about the Profession

Higher education institutions, responsible for training social educators, should ensure the construction of a profile marked by their technical versatility and whose socio-educational intervention is directed at all people, regardless of their situations in life. Reflection on the construction of this profile is fundamental given the difficulties of identity that the profession faces. In this context, we sought to develop a study which would allow us to identify how the students of a degree course in Social Education characterise this professional, in order to reflect on the contribution of training provided by the institution concerned and, if necessary, make the adjustments arising from the results. This is a qualitative, exploratory study, using an unstructured questionnaire applied to a convenience sample of 140 Portuguese students of the three years of a degree course in Social Education. Its emerging categorical content analysis was performed using the NVivo software, version 11. The main results point to a broad vision of the profession and are not limited to the work geared to specific populations or issues, valuing the relevance of the professional in the field of non-assistance socio-educational intervention. The main area of overlap between training objectives and students’ perceptions about practice allows the impact of training to be positively assessed, despite possible curricular adjustments resulting from further analysis, including the need to reinforce community intervention, undervalued by students, even though it plays a key role for social educators.

Student’s Perception on the Personal Impact of a Social Education Degree Internship

The functional profile of the social educator is based on the development of theoretical, technical and personal/relational skills, which should guide training courses organization. Assuming the shortcomings of a merely theoretical approach, besides a consistent preparation in theoretical and essential technical contents for socio-educational intervention, practice in context should be favoured as an opportunity to develop professional skills, together with a critical reflection on the functional profile. This study emerges from the need to reflect and rethink the internship, as well as how the respective supervision is developed, of the degree in social education at the School of Education of the Polytechnic Institute of Viseu, and it is based on the students’ perceptions about the impact of the internship on personal development. This is a qualitative and exploratory study, using the documentary analysis of 50 final internship reports. From the content analysis, four categories emerged referring to gains in terms of acquiring and managing knowledge, development of technical skills, personal and relational development and reinforcement of professional identity. The importance given to personal and relational development should be noted (41.4% of mentions) taking into account its relevance in constructing a professional identity. Findings on the technical skills and on the increase of profession knowledge, also by mobilising theoretical training, positively reinforce the internship model that is based on a proximity supervision approach and on a dialogical perspective of the professional learning.

Comparación entre los efectos de un programa de entrenamiento de fuerza explosiva mediante bandas elásticas y un programa de entrenamiento con electro-estimulación de cuerpo completo

El objetivo del presente estudio fue analizar los cambios en el rendimiento en función de dos métodos de entrenamiento, el desarrollado mediante electro-estimulación muscular integral (EMI) frente a otro en el que se utilizaron bandas elásticas y que denominamos entrenamiento funcional con elásticos (EFE). La muestra estuvo compuesta por un grupo de diez (N=10) personas físicamente activas (23,04 ± 2,5 años). Se utilizó un diseño cuasi-experimental con medidas pre-post. Y fueron analizados los resultados de las pruebas: salto vertical con ayuda de brazos; y velocidad de desplazamiento en una carrera de ida y vuelta de 12 metros de distancia (6+6). Se realizó un análisis descriptivo de casos y medias. Y dado el tamaño de la muestra se calculó el tamaño del efecto, el cual fue bajo o moderado (d<0,5). Por último se compararon las diferencias de las medias de los grupos mediante la U de Mann Whitney, y las diferencias de las medias en función del tiempo (pre-post) mediante Friedman; en ambos casos los resultados no fueron significativos (p<0,5). En cuanto a los valores descriptivos del pre-post en ambos grupos: el grupo que entrenó con bandas elásticas obtuvo mejores resultados en ambas pruebas que el grupo que entrenó con EMI. En conclusión, el entrenamiento con bandas elásticas, a pesar de no ser significativo, parece mostrarse más efectivo que el entrenamiento con electro-estimulación muscular integral. Si bien, dadas las limitaciones del estudio estos datos hay que tomarlos con la pertinente cautela.