A prototipagem rápida na modelação de patologias

A utilização da prototipagem rápida tem, cada vez mais, vindo a revelar-se como uma ferramenta de extremo valor no apoio à actividade médica. Partindo de imagens médicas bidimensionais provenientes de Tomografia Computorizada (TC) ou Ressonância Magnética (MRI) é possível a obtenção de modelos tridimensionais. Os modelos produzidos por prototipagem rápida têm utilidade quer em ambiente educacional, quer em ambiente médico- cirúrgico. Podem facilitar o diagnóstico de determinadas patologias, a elaboração de procedimentos cirúrgicos complexos, o fabrico de próteses, o fabrico de instrumentos médicos bem como a visualização de estruturas anatómicas em ambiente educacional

Quantitation of nine organic acids in wild mushrooms

The organic acids composition of six wild edible mushroom species ( Amanita caesarea, Boletus edulis, Gyroporus castaneus, Lactarius deliciosus, Suillus collinitus, and Xerocomus chrysenteron) was determined by an HPLC-UV detector method. The results showed that all of the samples presented a profile composed of at least five organic acids: citric, ketoglutaric, malic, succinic, and fumaric acids. Several samples also contained oxalic, ascorbic, quinic, and shikimic acids. In a general way, the quantitation of the identified compounds indicated that malic acid, followed by the pair citric plus ketoglutaric acids, were the main compounds in the analyzed species, with the exception of A. caesarea, in which malic and ascorbic acids were the most abundant compounds. The relative amounts and the presence/absence of each identified compound may be useful for the differentiation of the species

Effects of match location, quality of opposition and match outcome on match running performance in a Portuguese professional football team

The aim of this study was to analyze the effects of match location, quality of opposition and match outcome on match running performance according to playing position in a Portuguese professional football team. Twenty-three male professional football players were monitored from eighteen Portuguese Football League matches during the 2019–2020 season. Global positioning system technology (GPS) was used to collect time-motion data. The match running performance was obtained from five playing positions: central defenders (CD), fullbacks (FB), central midfielders (CM), wide midfielders (WM) and forwards (FW). Match running performance was analyzed within specific position and contextual factors using one-way analysis of variance (ANOVA) for repeated measures, standardized (Cohen) differences and smallest worthwhile change. CM and WM players covered significantly greater total distance (F = 15.45, p = 0.000, η2 = 0.334) and average speed (F = 12.79, p < 0.001, η2 = 0.294). WM and FB players covered higher distances at high-speed running (F = 16.93, p = 0.000, η2 = 0.355) and sprinting (F = 13.49; p < 0.001, η2 = 0.305). WM players covered the highest number of accelerations (F = 4.69, p < 0.001, η2 = 0.132) and decelerations (F = 12.21, p < 0.001, η2 = 0.284). The match running performance was influenced by match location (d = 0.06–2.04; CI: −0.42–2.31; SWC = 0.01–1.10), quality of opposition (d = 0.13–2.14; CI: –0.02–2.60; SWC = 0.01–1.55) and match outcome (d = 0.01–2.49; CI: −0.01–2.31; SWC = 0.01–0.35). Contextual factors influenced the match running performance with differential effects between playing positions. This study provides the first report about the contextual influence on match running performance in a Portuguese professional football team. Future research should also integrate tactical and technical key indicators when analyzing the match-related contextual influence on match running performanceThis research was supported by the Douro Higher Institute of Educational Sciences and the Portuguese Foundation for Science and Technology, I.P. (project UIDB04045/2021)info:eu-repo/semantics/publishedVersio

Modeling the major influencing factor on match running performance during the in-season phase in a Portuguese professional football team

The aim of this study was two-fold: (1) to analyze the influence of season phase (i.e., the start of the in-season and mid-in-season) on match running performance in a Portuguese professional football team; (2) to determine and model the main factor influencing match running performance during the in-season in this specific football team. Eighteen matches were collected by an 18 Hz global positioning system (GPS) from a professional Portuguese football team during the start of the in-season and mid-in-season. The match running performance was analyzed according to season phases, presenting significant differences in total distance (TD) (tlower bound = 4.71, p < 0.001; tupper bound = −2.22, p = 0.002), average speed (AvS) (tlower bound = 359.45, p < 0.001; tupper bound = −359.87, p < 0.001), and relative high speed running (rHSR) (tlower bound = 13.10, p < 0.001; tupper bound = −10.21, p < 0.001). The logistic regression showed TD (β = −1.59, z = −2.84, p = 0.005) and AvS (β = 2.68, z = −2.84, p = 0.007) as the major factors influencing match running performance during seasonal variation. Sprints and accelerations showed no significance for predicting match running performance during the season phases (β = −0.05 to 1.07, z = −0.95 to 1.07, p = 0.29 to 0.72). Current research confirms that lower and upper bounds should be used to quantify seasonal differences on match running performance. TD and AvS were described as the main factors influencing match running performance during the in-season phase. Thus, it is important to highlight the pace and volume of the game to maximize match running performance.This project was supported by the National Funds through FCT—Portuguese Foundation for Science and Technology (UIDB/DTP/04045/2020).info:eu-repo/semantics/publishedVersio

Weekly training load across a standard microcycle in a sub-elite youth football academy: a comparison between starters and non-starters

Compensatory training sessions have been highlighted as useful strategies to solve the differential weekly training load between the players’ starting status. However, the influence of the players’ starting status is still understudied in sub-elite youth football. Thus, the aim of this study was to compare the weekly training load on a standard microcycle in starters and non-starters of a sub-elite youth football academy. The weekly training load of 60 young sub-elite football players was monitored during a 6-week period using an 18 Hz global positioning system (GPS), 1 Hz telemetry heart rate, rating of perceived exertion (RPE), and total quality recovery (TQR). The total distance (TD) covered presented a significant difference between starters and non-starters with a moderate effect (t = 2.38, D = 428.03 m, p = 0.018, d = 0.26). Training volume was higher in non-starters than in starter players (TDStarters = 5105.53   1684.22 vs. TDNon-starters = 5533.56   1549.26 m). Significant interactive effects were found between a player’s starting status, playing time, and session duration in overall training load variables for within (F = 140.46;  2 = 0.85; p < 0.001) and between-subjects (F = 11.63 to 160.70;  2 = 0.05 to 0.76; p < 0.001). The player’s starting status seems to only influence the training volume in sub-elite youth football, unless one considers the covariance of the playing time and session duration. Consequently, coaches should prioritize complementary training to equalize training volume and emphasize similar practice opportunities for non-starters. Future studies should evaluate the gap between training and match load, measuring the impact of recovery and compensatory sessions.This project was supported by the National Funds through the FCT—Portuguese Foundation for Science and Technology (project UIDB04045/2021).info:eu-repo/semantics/publishedVersio

Medição da potência, força, velocidade e eficácia mecânica no Futebol: considerações teóricas

Power-force-velocity profiles in football can be assessed by Samozino’s formulas to determine theoretical maximal velocity (V0), theoretical horizontal force (F0), horizontal power (Pmax) and force-velocity (F-V) profile (i.e., the slope of the F-V relationship; Sfv), ratio of force (RFmax) and index of force application technique (DRF). Current critical review aims to explain the theoretical and methodological procedures for measuring power, force, velocity, and mechanical effectiveness in Football. In conclusion, Samozino’s method is sensitive, straightforward, and cost-effective for measuring F-V relationship and mechanical effectiveness in Football. Therefore, this methodological approach should be considered in field-based assessment and monitoring strategy of the football players. Future research should also include different competitive level such as elite, sub-elite and recreational for measuring power, force, velocity, and mechanical effectiveness in male, female, and youth football environments.Os perfis potência-força-velocidade no futebol podem ser avaliados pelas fórmulas de Samozino, de modo a determinar a velocidade máxima teórica (V0), a força máxima teórica (F0), a potencia máxima teórica (Pmax), o perfil força velocidade (F-V) (inclinação da relação F- V, Sfv), a razão de força (RFmax) e o índice da técnica de aplicação de força (DRF). A presente revisão crítica pretende esmiuçar os procedimentos teóricos e metodológicos para mensurar a potência, a força, a velocidade e a eficácia mecânica no Futebol. Concluiu-se que o método de Samozino é sensível, prático e económico para medir a relação F-V e a eficácia mecânica no Futebol. Assim, esta abordagem metodológica deve ser considerada nas estratégias de campo para a avaliação e monitorização de jogadores de futebol. As futuras investigações devem considerar igualmente os diferentes níveis competitivos, concretamente os contextos elite, subelite e amadores, aportando novas evidências para a mensuração da potência, força, velocidade e eficácia mecânica em contextos de futebol masculino, feminino e juvenil.info:eu-repo/semantics/publishedVersio

A high performance cost-effective digital complex correlator for an X-band polarimetry survey

The detailed knowledge of the Milky Way radio emission is important to characterize galactic foregrounds masking extragalactic and cosmological signals. The update of the global sky models describing radio emissions over a very large spectral band requires high sensitivity experiments capable of observing large sky areas with long integration times. Here, we present the design of a new 10 GHz (X-band) polarimeter digital back-end to map the polarization components of the galactic synchrotron radiation field of the Northern Hemisphere sky. The design follows the digital processing trends in radio astronomy and implements a large bandwidth (1 GHz) digital complex cross-correlator to extract the Stokes parameters of the incoming synchrotron radiation field. The hardware constraints cover the implemented VLSI hardware description language code and the preliminary results. The implementation is based on the simultaneous digitized acquisition of the Cartesian components of the two linear receiver polarization channels. The design strategy involves a double data rate acquisition of the ADC interleaved parallel bus, and field programmable gate array device programming at the register transfer mode. The digital core of the back-end is capable of processing 32 Gbps and is built around an Altera field programmable gate array clocked at 250 MHz, 1 GSps analog to digital converters and a clock generator. The control of the field programmable gate array internal signal delays and a convenient use of its phase locked loops provide the timing requirements to achieve the target bandwidths and sensitivity. This solution is convenient for radio astronomy experiments requiring large bandwidth, high functionality, high volume availability and low cost. Of particular interest, this correlator was developed for the Galactic Emission Mapping project and is suitable for large sky area polarization continuum surveys. The solutions may also be adapted to be used at signal processing subsystem levels for large projects like the square kilometer array testbeds

The Association between external training load, perceived exertion and total quality recovery in Sub-Elite youth football

Moderate to very large correlation between internal training load, external training load, and recovery status have been reported in elite youth football. However, little is known about subelite youth football training environments. Objective: The purpose of this study was to assess the association between training load and recovery status in young subelite football players. Methods: Twenty under-15, twenty under-17, and twenty under-19 players were monitored over a 6-week period during the first month of the 2019-2020 competitive season. The global positioning system technology (GPS) was used to collect external training load variables. The internal training load variables were monitored using the rating of perceived exertion (RPE) scale and session RPE (sRPE). The recovery status was assessed by the total quality recovery (TQR). A total of 18 training sessions and 324 observation cases were collected. Results: Small to moderate correlation between internal and external load was observed r( = -0.316 to 0.136, p < 0.05). Correlations between recovery status and external load were moderate for U15 (r = -0.326 to -0.240, p < 0.05), U17 (r = -0.316 to 0.136, p < 0.05) and U19 (r = -0.301 to 0.282, p < 0.05). The association between perceived exertion and external training load is only significant for U19 subelite football players. Conclusion: Current research suggested that subelite youth football players were more likely to have lower capacity to judge training exertion. Additionally, recovery status was positively correlated with acceleration and deceleration movements. This study provides a new overview about training load and recovery in subelite youth training environment. Future researche should examine the between- and within-individual nonlinearity across training load and recovery variations.This project was supported by the National Funds through FCT-Portuguese Foundation for Science and Technology (UIDB/DTP/04045/2020).info:eu-repo/semantics/publishedVersio

Developing a data fusion concept for radar and optical ground based SST station

As part of the Portuguese Space Surveillance and Tracking (SST) program, a tracking radar and a double Wide Field of View Telescope system (4.3{\deg} x 2.3{\deg}) are being installed at the Pampilhosa da Serra Space Observatory (PASO) in the centre of continental Portugal, complementing an already installed deployable optical sensor for MEO and GEO surveillance. The tracking radar will track space debris in Low Earth Orbit (LEO) up to 1000 km and at the same time the telescope will also have LEO tracking capabilities. This article intends to discuss possible ways to take advantage of having these two sensors at the same location. Using both types of sensors takes advantage of the radar measurements which give precise radial velocity and distance to the objects, while the telescope gives better sky coordinates measurements. With the installation of radar and optical sensors, PASO can extend observation time of space debris and correlate information from optical and radar provenances in real time. During twilight periods both sensors can be used simultaneously to rapidly compute new TLEs for LEO objects, eliminating the time delays involved in data exchange between sites in a large SST network. This concept will not replace the need for a SST network with sensors in multiple locations around the globe, but will provide a more complete set of measurements from a given object passage, and therefore increase the added value for initial orbit determination, or monitoring of reentry campaigns of a given location. PASO will contribute to the development of new solutions to better characterize the objects improving the overall SST capabilities and constitute a perfect site for the development and testing of new radar and optical data fusion algorithms and techniques for space debris monitoring.Comment: 3 pages, 3 figures, Draft accepted for publication at 73rd International Astronautical Congress, Paris 202