Transcriptional reprogramming in sound-treated Micro-Tom plants inoculated with Pseudomonas syringae pv. tomato DC3000.

Sound vibrations (SV) are known to influence molecular and physiological processes that can improve crop performance and yield. In this study, the effects of three audible frequencies (100, 500 and 1000 Hz) at constant amplitude (90 dB) on tomato Micro-Tom physiological responses were evaluated 1 and 3 days post-treatment. Moreover, the potential use of SV treatment as priming agent for improved Micro-Tom resistance to Pseudomonas syringae pv. tomato DC3000 was tested by microarray. Results showed that the SV-induced physiological changes were frequency- and time-dependent, with the largest changes registered at 1000 Hz at day 3. SV treatments tended to alter the foliar content of photosynthetic pigments, soluble proteins, sugars, phenolic composition, and the enzymatic activity of polyphenol oxidase, peroxidase, superoxide dismutase and catalase. Microarray data revealed that 1000 Hz treatment is effective in eliciting transcriptional reprogramming in tomato plants grown under normal conditions, but particularly after the infection with Pst DC3000. Broadly, in plants challenged with Pst DC3000, the 1000 Hz pretreatment provoked the up-regulation of unique differentially expressed genes (DEGs) involved in cell wall reinforcement, phenylpropanoid pathway and defensive proteins. In addition, in those plants, DEGs associated with enhancing plant basal immunity, such as proteinase inhibitors, pathogenesis-related proteins, and carbonic anhydrase 3, were notably up-regulated in comparison with non-SV pretreated, infected plants. These findings provide new insights into the modulation of Pst DC3000-tomato interaction by sound and open up prospects for further development of strategies for plant disease management through the reinforcement of defense mechanisms in Micro-Tom plants.

Design, Development and Testing of a Monitoring System for the Study of Proton Exchange Fuel Cells and Stacks.

This article is about the design, development and validation of a new monitoring architecture for individual cells and stacks to facilitate the study of proton exchange fuel cells. The system consists of four main elements: input signals, signal processing boards, analogue-to-digital converters (ADCs) and a master terminal unit (MTU). The latter integrates a high-level graphic user interface (GUI) software developed by National Instruments LABVIEW, while the ADCs are based on three digital acquisition units (DAQs). Graphs showing the temperature, currents and voltages in individual cells as well as stacks are integrated for ease of reference. The system validation was carried out both in static and dynamic modes of operation using a Ballard Nexa 1.2 kW fuel cell fed by a hydrogen cylinder, with a Prodigit 32612 electronic load at the output. The system was able to measure the voltage distributions of individual cells, and temperatures at different equidistant points of the stack both with and without an external load, validating its use as an indispensable tool for the study and characterization of these systems.

Microwave Radiation as an Inducer of Secondary Metabolite Production in Drosera rotundifolia In Vitro Plantlets.

In this study, low-intensity microwave irradiation (frequency of 2.45 GHz; 26.3 kW m-3 power density) for 0, 5, and 30 s was tested for the first time on Drosera rotundifolia in vitro plantlets to explore its effect on the production of highly valued phenolic compounds. Analysis of the extracts obtained from irradiated plantlets revealed time-dependent increases in the levels of photosynthetic pigments, particularly the carotenoids, whereas symptoms of growth decline were not observed. Similarly, the highest total antioxidant capacity and total phenolic and flavonoid contents were detected in 30-s-irradiated plantlets. High-performance liquid chromatography analysis revealed that the content of the bioactive phenolics 5-hydroxy-7-methylnaphthalene-1,4-dione (1), 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxychromen-4-one (2), and 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-3-[(3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxychromen-4-one (3), which are considered to be responsible for the pharmacological properties of this species, was around twofold higher in 30-s-irradiated plantlets than in controls. Nevertheless, the accumulation of 5-hydroxy-2-methylnaphthalene-1,4-dione (4), which was present only in trace amounts in the plant roots, decreased by 30% upon microwave irradiation. The results indicate that microwave treatment acts as an effective inducer of the production of phenylpropanoid compounds, which opens up new opportunities for its use in biotechnological applications.

Differential Response of Phenol Metabolism Associated with Antioxidative Network in Elicited Grapevine Suspension Cultured Cells under Saline Conditions.

Highly productive trans-resveratrol (t-R) grapevine suspension cultured cells (SCC) and two effective elicitors, methyl jasmonate (MJ) and randomly methylated ß-cyclodextrins (CDs), were used to analyze the extent to which salt treatments alter the production of bioactive phenolic compounds. The expression/activity profile of the enzymes involved in phenol metabolism and antioxidant networks were also studied. A marked extracellular accumulation of phenolic compounds, especially t-R, was found in SCC elicited with CDs and/or MJ under saline conditions. However, the treatments with MJ alone and all those combined with salt favored the intracellular accumulation of catechin and ferulic acid. The salt-induced accumulation of phenolics was correlated with the higher total antioxidant capacity values found in cells, suggesting that cellular redox homeostasis under saline conditions was largely maintained by increasing phenolic compound production. These higher levels of phenolics found in elicited cells under saline conditions fit well with the highest activity of phenylalanine ammonia-lyase. Moreover, antioxidant enzyme activities were boosted in treatments with MJ and/or in those combined with salt and decreased in those treated with CDs. These results suggest a differential response of the antioxidative network to the presence of elicitors under saline conditions.

Configurable IoT Open-Source Hardware and Software I-V Curve Tracer for Photovoltaic Generators.

Photovoltaic (PV) energy is a renewable energy resource which is being widely integrated in intelligent power grids, smart grids, and microgrids. To characterize and monitor the behavior of PV modules, current-voltage (I-V) curves are essential. In this regard, Internet of Things (IoT) technologies provide versatile and powerful tools, constituting a modern trend in the design of sensing and data acquisition systems for I-V curve tracing. This paper presents a novel I-V curve tracer based on IoT open-source hardware and software. Namely, a Raspberry Pi microcomputer composes the hardware level, whilst the applied software comprises mariaDB, Python, and Grafana. All the tasks required for curve tracing are automated: load sweep, data acquisition, data storage, communications, and real-time visualization. Modern and legacy communication protocols are handled for seamless data exchange with a programmable logic controller and a programmable load. The development of the system is expounded, and experimental results are reported to prove the suitability and validity of the proposal. In particular, I-V curve tracing of a monocrystalline PV generator under real operating conditions is successfully conducted.

Grouping Students by Skill Level in Mini-Volleyball: Effect on Game Performance and Knowledge in Sport Education.

The purpose of this study was to explore any differences in game performance variables and knowledge among a cohort of high school students who participated in either homogeneous or heterogeneous skill level groups (N = 126) across a 12-lesson mini-volleyball sport education unit of study. This study followed a mixed-methods approach using a quasi-experimental pre-test/post-test design. The quantitative variables analyzed were decision making, skill execution, game performance, game involvement, and game knowledge. We also evaluated students' performance qualitatively, employing two methods: (a) experts' analysis of students' game performance, and (b) students' and teachers' perceptions of students' performance. We analyzed quantitative data through a series of paired samples t-tests comparing pre- and post-test scores according to the grouping strategy. Students became more competent in their game play and more knowledgeable in their technique, the sport's rules, tactical awareness, and general game knowledge. However, grouping students by skill level had no impact on gains in game performance variables and knowledge. Although sport education literature shows a preference for heterogeneity in ability-based grouping, within our data both heterogeneous and homogenous groups of higher and lower skilled students achieved improvements in game performance and knowledge, leading us to suggest that teachers who are interested in grouping students to create a meaningful learning experience should consider criteria other than student ability.

OPDA and ABA accumulation in Pb-stressed Zygophyllum fabago can be primed by salicylic acid and coincides with organ-specific differences in accumulation of phenolics.

Salicylic acid (SA) is a well-known priming agent that is widely used to protect plants against stressing agents, including heavy metals as Pb. A better understanding of the mechanisms that enable plants to counteract Pb toxicity would help to select strategies for land reclamation programs. Here we used a metallicolous population of Zygophyllum fabago to assess the extent to which SA pretreatment modulates Pb-induced changes in phenol metabolism and stress-related phytohormone levels in roots and leaves. Our data revealed that accumulation of different phytohormones, lignin, soluble and wall-bound phenolics as well as peroxidase (PRX) activity in Pb-stressed plants differed after SA-pretreatment. Exposure to Pb led to the induction of soluble and cell wall-bound PRX activities, particularly those involved in the oxidation of coniferyl alcohol and ferulic acid, while pretreatment with SA reduced the Pb-induced stimulation of PRX activities in roots but increased them in leaves. SA-treatment by itself induced accumulation of ABA and the JA-precursor 12-oxo-phytodienoic acid (OPDA) in the roots. Pb in turn inhibited these SA-induced effects with the exception of OPDA accumulation that was primed by the pretreatment. The SA treatment also induced accumulation of OPDA in leaves but suppressed the accumulation of JA-Ile although with relatively small absolute changes. Notably, Pb-induced accumulation of ABA was primed in the leaves of SA-pretreated plants. Together our data suggest that priming of OPDA accumulation in the roots and of ABA in the leaves by SA-pretreatment may play important regulatory roles, possibly via regulating PRX activities, for Pb stress in plants.

Subtle changes in light intensity affect in vitro responses but not ex vitro performance of Limonium sinuatum.

Environmental conditions during the in vitro stages of a micropropagation process can further affect the ex vitro plant performance. In this work, the behaviour of four blue cultivars of statice (Limonium sinuatum) was studied with respect to four distances (18.0, 12.5, 8.0, or 2.0 cm) between culture tubes and the light source during their in vitro multiplication stage. In vitro shoots of statice were cultured on MS medium supplemented with 4% sucrose, 0.9% agar and 0.2 mg L-1 BA and incubated under four slightly different light intensity treatments (PPFD of 96.9, 99.6, 101.2, or 102.7 µmol m-2 s-1) for 35 days at 23 °C with a daily photoperiod of 16 h. The light treatments assayed resulted in no significant differences in in vitro propagation ratio and ex vitro survival and crop production and quality (as judged by the number of inflorescence stems per plant, length of inflorescence stems and number of both spikes and branches per stem produced). However, in vitro growth (estimated as the length of the longest leaf in a shoot at the end of the culture period) and levels of pigments (chlorophylls and carotenoids) and antioxidants (as estimated by the DPPH test) showed variations among cultivars. This indicates that statice cultivars were able to adjust their metabolism in response to the small differences in light intensity of the treatments applied. Results point to the importance of optimization of growth room use to increase profitability of micropropagation processes.

Seasonal ionomic and metabolic changes in Aleppo pines growing on mine tailings under Mediterranean semi-arid climate.

Aleppo pine is the most abundant conifer species in Mediterranean basin. Knowledge of adaptive mechanisms to cope with different environmental stresses simultaneously is necessary to improve its resilience to the predicted climatic changes and anthropogenic stressors, such as heavy metal/metal(loid)s (HMMs) pollution. Here, one year-old needles and rhizosphere soil samples from five mining and non-mining (NM) populations of Aleppo pines grown spontaneously in SE Spain were sampled in two consecutive years during spring and summer. Quantitative determination of a wide suite of edaphic, biochemical, and physiological parameters was performed, including soil physicochemical properties, ionome profile, foliar redox components, primary and secondary metabolites. Mining rhizosphere soils were characterized by elevated contents of HMMs, particularly lead and zinc, and low carbon, nitrogen and potassium levels. Multivariate data analysis based on needle ionome and antioxidative/oxidative parameters revealed a clear distinction between seasons irrespective of the population considered. Spring needles were characterized by higher levels of HMMs, sulfur, glutathione (GSH), proanthocyanidins (PAs), and soluble phenols (TPC), whereas reduced chlorophylls and increased levels of carotenoids, relative water content and K+, Na+ and Cl- typified summer needles. In general mining populations had higher levels of ascorbate, and TPC, and exhibited higher antioxidant activities than the NM population. This could contribute to prevent oxidative injury induced by HMMs. Taken together, results suggest that seasonal factors have a more marked effect on the metabolism of the Aleppo pine populations studied than that exerted by soil conditions. This effect could be mediated by water availability in surface soil layers. If this conclusion is right, predicted rainfall reduction and temperature increase in the Mediterranean basin associated to global climate change would lead to pine needle metabolism to express the summer pattern for more prolonged periods. This, in turn, could negatively affect the performance of Aleppo pine populations.

Coordinated role of soluble and cell wall bound phenols is a key feature of the metabolic adjustment in a mining woody fleabane (Dittrichia viscosa L.) population under semi-arid conditions.

Environmental contamination by hazardous heavy metals/metalloids (metal(loid)s) is growing worldwide. To restrict the migration of toxic contaminants, the establishment of a self-sustainable plant cover is required. Plant growth in multi-polluted soils is a challenging issue not only by metal(loid) toxicities, but also by the co-occurrence of other stressors. Dittrichia viscosa is a pioneer Mediterranean species able to thrive in metal(loid)-enriched tailings in semi-arid areas. The aim of the present work was to examine the metabolic adjustments involved in the acclimation responses of this plant to conditions prevailing in mine-tailings during Mediterranean spring and summer. For this purpose, fully-expanded leaves, and rhizosphere soil of both mining and non-mining populations of D. viscosa grown spontaneously in south-eastern Spain were sampled in two consecutive years. Quantitative analysis of >50 biochemical, physiological and edaphic parameters were performed, including nutrient status, metal(loid) contents, leaf redox components, primary and secondary metabolites, salicylic acid levels, and soil physicochemical properties. Results showed that mining plants exhibited high foliar Zn/Pb co-accumulation capacity, without substantially affecting their photosynthetic metabolism or nutritional status even in the driest summer period. The comparison of the antioxidative/oxidative profile between mining and non-mining D. viscosa populations revealed no major seasonal changes in the content of primary antioxidants (ascorbate and GSH), or in the levels of ROS. Multivariate analysis showed that phenylalanine ammonia-lyase (PAL) and peroxidase (PRX) activities and soluble and cell wall-bound phenols were potential biomarkers for discriminating between both populations. During the dry season, a marked enhancement in the activity of both PAL and soluble PRX resulted in both a drop in the accumulation of soluble phenols and an increase of the strong metal chelator caffeic acid in the cell-wall fraction, supporting the view that the plasticity of phenylpropanoid metabolism provide an effective way to counteract the effects of stress combinations.

Different mechanisms of the metalliferous Zygophyllum fabago shoots and roots to cope with Pb toxicity.

Lead (Pb) remains classified as a priority pollutant. Zygophyllum fabago is considered an early colonizer of heavy metal-polluted soils under semiarid conditions, but physiological mechanisms underlying this colonizing capacity remain unclear. In order to characterize Z. fabago plants' performance on Pb-contaminated soils, we evaluated how Pb influenced root and shoot growth, carbon metabolism, and oxidative status. For that, 30-day-old seedlings from one population colonizing a mine tailing ("Mercader") at Murcia (southeast Spain) were exposed to 500-µM Pb(NO3)2 for 1 week. Results showed that this high dose of Pb induced no plant mortality nor senescence, though promoting plant nanism. Besides the efficiency of roots to accumulate Pb, shoots also demonstrate a high efficiency to translocate and accumulate this metal. Pb exposure decreased Zn uptake to the aerial part and reduced net photosynthetic rate (A), RuBisCO activity, chlorophyll, and soluble sugar contents in shoots. Moreover, in shoots, Pb exposure increased the levels of O2- and decreased antioxidant capacity, culminating with a loss of cell membrane integrity (electrolyte leakage) and increased protein oxidation. Compared to controls, exposed roots had less Mn and Zn levels, and despite the rise in H2O2 levels, they were able to modulate non-protein thiols presenting a robust defense capacity. This capacity may support the roots' ability to maintain cell membrane integrity (electrolyte leakage) with regard to control. Principal component analysis (PCA) contributed to elucidate how this species adjusts physiological mechanisms to cope with Pb toxicity, showing that roots and shoots evolved different antioxidant defenses, which demonstrates the importance of organ specificity in the response of Z. fabago to heavy metals.

Some Hardware and Instrumentation Aspects of the Development of an Automation System for Jar Tests in Drinking Water Treatment.

The so-called Jar Test (JT) plays a vital role in the drinking water and wastewater treatments for establishing the dosage of flocculants and coagulant. This test is a well-proved laboratory instrumental procedure performed by trained personnel. In this work, a completely novel system for the automation and monitoring of a JT devoted to drinking water treatment is presented. It has been implemented using an industrial programmable controller and sensors and instruments specifically selected for this purpose. Once the parameters of the test have been entered, the stages that compose the JT (stirring, coagulant addition, etc.) are sequentially performed without human intervention. Moreover, all the involved measurements from sensors are collected and made accessible for continuous monitoring of the process. By means of the proposed system, the JT procedure is conducted fully automatically and can be locally and remotely monitored in real-time. Furthermore, the developed system constitutes a portable laboratory that offers advantageous features like scalability and transportability. The proposed system is described focusing on hardware and instrumentation aspects, and successful results are reported.

Integration of Sensors, Controllers and Instruments Using a Novel OPC Architecture.

The interconnection between sensors, controllers and instruments through a communication network plays a vital role in the performance and effectiveness of a control system. Since its inception in the 90s, the Object Linking and Embedding for Process Control (OPC) protocol has provided open connectivity for monitoring and automation systems. It has been widely used in several environments such as industrial facilities, building and energy automation, engineering education and many others. This paper presents a novel OPC-based architecture to implement automation systems devoted to R&D and educational activities. The proposal is a novel conceptual framework, structured into four functional layers where the diverse components are categorized aiming to foster the systematic design and implementation of automation systems involving OPC communication. Due to the benefits of OPC, the proposed architecture provides features like open connectivity, reliability, scalability, and flexibility. Furthermore, four successful experimental applications of such an architecture, developed at the University of Extremadura (UEX), are reported. These cases are a proof of concept of the ability of this architecture to support interoperability for different domains. Namely, the automation of energy systems like a smart microgrid and photobioreactor facilities, the implementation of a network-accessible industrial laboratory and the development of an educational hardware-in-the-loop platform are described. All cases include a Programmable Logic Controller (PLC) to automate and control the plant behavior, which exchanges operative data (measurements and signals) with a multiplicity of sensors, instruments and supervisory systems under the structure of the novel OPC architecture. Finally, the main conclusions and open research directions are highlighted.

Easy Handling of Sensors and Actuators over TCP/IP Networks by Open Source Hardware/Software.

There are several specific solutions for accessing sensors and actuators present in any process or system through a TCP/IP network, either local or a wide area type like the Internet. The usage of sensors and actuators of different nature and diverse interfaces (SPI, I2C, analogue, etc.) makes access to them from a network in a homogeneous and secure way more complex. A framework, including both software and hardware resources, is necessary to simplify and unify networked access to these devices. In this paper, a set of open-source software tools, specifically designed to cover the different issues concerning the access to sensors and actuators, and two proposed low-cost hardware architectures to operate with the abovementioned software tools are presented. They allow integrated and easy access to local or remote sensors and actuators. The software tools, integrated in the free authoring tool Easy Java and Javascript Simulations (EJS) solve the interaction issues between the subsystem that integrates sensors and actuators into the network, called convergence subsystem in this paper, and the Human Machine Interface (HMI)-this one designed using the intuitive graphical system of EJS-located on the user's computer. The proposed hardware architectures and software tools are described and experimental implementations with the proposed tools are presented.

Seasonal changes in antioxidative/oxidative profile of mining and non-mining populations of Syrian beancaper as determined by soil conditions.

Soil pollution by heavy metals/metalloids (HMMs) is a problem worldwide. To prevent dispersion of contaminated particles by erosion, the maintenance of a vegetative cover is needed. Successful plant establishment in multi-polluted soils can be hampered not only by HMM toxicities, but also by soil nutrient deficiencies and the co-occurrence of abiotic stresses. Some plant species are able to thrive under these multi-stress scenarios often linked to marked fluctuations in environmental factors. This study aimed to investigate the metabolic adjustments involved in Zygophyllum fabago acclimative responses to conditions prevailing in HMM-enriched mine-tailings piles, during Mediterranean spring and summer. To this end, fully expanded leaves, and rhizosphere soil, of three contrasting mining and non-mining populations of Z. fabago grown spontaneously in south-eastern Spain were sampled in two consecutive years. Approximately 50 biochemical, physiological and edaphic parameters were examined, including leaf redox components, primary and secondary metabolites, endogenous levels of salicylic acid, and physicochemical properties of soil (fertility parameters and total concentration of HMMs). Multivariate data analysis showed a clear distinction in antioxidative/oxidative profiles between and within the populations studied. Levels of chlorophylls, proteins and proline characterized control plants whereas antioxidant capacity and C- and S-based antioxidant compounds were biomarkers of mining plants. Seasonal variations were characterized by higher levels of alkaloids and PAL and soluble peroxidase activities in summer, and by soluble sugars and hydroxycinnamic acids in spring irrespective of the population considered. Although the antioxidant systems are subjected to seasonal variations, the way and the intensity with which every population changes its antioxidative/oxidative profile seem to be determined by soil conditions. In short, Z. fabago displays a high physiological plasticity that allow it to successfully shift its metabolism to withstand the multiple stresses that plants must cope with in mine tailings piles under Mediterranean climatic conditions.

Novel Networked Remote Laboratory Architecture for Open Connectivity Based on PLC-OPC-LabVIEW-EJS Integration. Application in Remote Fuzzy Control and Sensors Data Acquisition.

In this paper the design and implementation of a network for integrating Programmable Logic Controllers (PLC), the Object-Linking and Embedding for Process Control protocol (OPC) and the open-source Easy Java Simulations (EJS) package is presented. A LabVIEW interface and the Java-Internet-LabVIEW (JIL) server complete the scheme for data exchange. This configuration allows the user to remotely interact with the PLC. Such integration can be considered a novelty in scientific literature for remote control and sensor data acquisition of industrial plants. An experimental application devoted to remote laboratories is developed to demonstrate the feasibility and benefits of the proposed approach. The experiment to be conducted is the parameterization and supervision of a fuzzy controller of a DC servomotor. The graphical user interface has been developed with EJS and the fuzzy control is carried out by our own PLC. In fact, the distinctive features of the proposed novel network application are the integration of the OPC protocol to share information with the PLC and the application under control. The user can perform the tuning of the controller parameters online and observe in real time the effect on the servomotor behavior. The target group is engineering remote users, specifically in control- and automation-related tasks. The proposed architecture system is described and experimental results are presented.

A New, Scalable and Low Cost Multi-Channel Monitoring System for Polymer Electrolyte Fuel Cells.

In this work a new, scalable and low cost multi-channel monitoring system for Polymer Electrolyte Fuel Cells (PEFCs) has been designed, constructed and experimentally validated. This developed monitoring system performs non-intrusive voltage measurement of each individual cell of a PEFC stack and it is scalable, in the sense that it is capable to carry out measurements in stacks from 1 to 120 cells (from watts to kilowatts). The developed system comprises two main subsystems: hardware devoted to data acquisition (DAQ) and software devoted to real-time monitoring. The DAQ subsystem is based on the low-cost open-source platform Arduino and the real-time monitoring subsystem has been developed using the high-level graphical language NI LabVIEW. Such integration can be considered a novelty in scientific literature for PEFC monitoring systems. An original amplifying and multiplexing board has been designed to increase the Arduino input port availability. Data storage and real-time monitoring have been performed with an easy-to-use interface. Graphical and numerical visualization allows a continuous tracking of cell voltage. Scalability, flexibility, easy-to-use, versatility and low cost are the main features of the proposed approach. The system is described and experimental results are presented. These results demonstrate its suitability to monitor the voltage in a PEFC at cell level.

Encapsulation efficiency of CdSe/ZnS quantum dots by liposomes determined by thermal lens microscopy.

In this study the encapsulation of core shell carboxyl CdSe/ZnS quantum dots (QDs) by phospholipids liposome complexes is presented. It makes the quantum dots water soluble and photo-stable. Fluorescence self-quenching of the QDs inside the liposomes was observed. Therefore, the thermal lens microscopy (TLM) was found to be an useful tool for measuring the encapsulation efficiency of the QDs by the liposomes, for which an optimum value of 36% was determined. The obtained limit of detection (LOD) for determining QDs concentration by TLM was 0.13 nM. Moreover, the encapsulated QDs showed no prominent cytotoxicity toward Breast cancer cells line MDA-MB-231. This study was supported by UV-visible spectroscopy, high resolution transmission electron microscopy (HRTEM) and dynamic light scattering measurements (DLS).

Relación del conocimiento táctico de jóvenes futbolistas con la edad, la experiencia y el nivel de pericia / Relação entre o conhecimento tático de jovens jogadores sobre a idade, a experiência eo nível de especialização / Relationship between young soccer players’ tactical knowledge and age, experience and level of expertise

Dada la importancia del conocimiento previo para decidir de forma adaptable en el deporte, se estudió el conocimiento táctico de 109 jóvenes futbolistas de ocho a doce años y su relación con la edad, la experiencia y el nivel de pericia, mediante el Test de Conocimiento Táctico Ofensivo en Fútbol. Se observaron diferencias significativas de magnitud moderada en función de la edad y la experiencia en competición federada de los jugadores (p < ,05; r < ,40), aunque los resultados fueron dispares. El nivel de pericia correlacionó significativamente con los conocimientos declarativo (rho = ,350; p < ,01), procedimental (rho = ,446; p < ,01) y táctico de los jugadores (rho = ,446; p < ,01). Los hallazgos sugieren que la edad y experiencia no tienen un papel tan determinante sobre el conocimiento táctico como otras variables: metodologías de enseñanza recibidas o la formación del entrenador. Se necesitan estudios en los que se analice si la formación específica en el conocimiento de los problemas tácticos mejora la habilidad de toma de decisiones en el deporte en general y en el fútbol base en particular (AU)

Dada a importância de uma boa base de conhecimento antes de decidir de forma adaptativa no desporto, reações de 109 jovens futebolistas oito e doze anos e sua relação com o conhecimento, idade, experiência em competição e nível de especialização por meio do Teste ofensivo Futebol Tactical Conhecimento é estudado. Foram observadas diferenças significativas de magnitude moderada versus idade e experiência em competição jogadores federados (r < ,40; p < ,05), embora os resultados foram mistos. O nível de especialização significativamente correlacionada com o conhecimento declarativo (rho = 350, p < ,01), e os jogadores táticos (rho = ,446; p < ,01), processual (rho = ,446; p < ,01) . Os resultados sugerem que a idade ea experiência não são decisivo de conhecimento tático como no papel e outras variáveis: metodologias de ensino e formação recebidos do treinador. São necessários mais studos que testam se o treinamento específico no conhecimento dos problemas táticos aumenta a capacidade de tomada de decisão no desporto em geral eo futebol em particular (AU)

Given the importance of prior knowledge on adaptable decision making in sport, tactical knowledge of 109 youth soccer players (8-12 years) and its relationship with age, experience and expertise was studied using The Soccer Tactical Knowledge Test. Moderate magnitude significant differences were observed depending on the age and experience in federated competitions of the players (p < ,05; r < ,40), although results were mixed. The expertise correlated significantly with declarative (rho = ,350; p < ,01), procedural (rho = ,446; p < ,01) and tactical knowledge of the players (rho = ,446; p < ,01). Findings suggest that age and experience would not be as decisive over tactical knowledge as other variables not studied: teaching methods, formal instruction, or coach formation. It is necessary more research to examine whether specific formation on tactical problems concepts could improve decision-making in sport and in youth soccer (AU)

Efecto de una intervención basada en el modelo de Educación Deportiva sobre variables psicológicas en nadadores federados / / O efeito modelo Educação Desportiva em variáveis psicológicas em nadadores federados / Effect of a Sport Education season on psychological variables in youth swimmers

Las aplicaciones prácticas del modelo de Educación Deportiva son del todo conocidas en el contexto escolar y están presentes en numerosas investigaciones. Sin embargo, no se ha reportado información sobre su efecto en el contexto extraescolar o deportivo, ni en deportes con predominio técnico como es la natación. Por ello, se realizó un estudio piloto con diseño cuasi-experimental en nadadores federados (n=24) de diferentes categorías (benjamín, alevín e infantil). El programa de intervención, basado en la Educación Deportiva, se compuso de 16 sesiones de entrenamiento. Al analizar pre y post las variables objeto de estudio (Percepción de soporte de autonomía; Grado de disfrute y competencia percibida; y Grado de compromiso deportivo) se observaron mejoras estadísticamente significativas. Tal comportamiento fue posteriormente reforzado al diseñar un modelo de ecuaciones estructurales en el que se hipotetizó que la percepción de soporte de autonomía predice positivamente el grado de disfrute y competencia percibida, y con ello, el grado de compromiso deportivo de los jóvenes nadadores. Además, se analizaron las entrevistas realizadas a los nadadores y el diario del entrenador mediante el software NVivo10, para conocer los principales indicadores sobre la percepción de los nadadores (responsabilidad, aprendizaje técnico e implicación) y del entrenador (trabajo en equipo, comunicación y predisposición). Los resultados, que corroboran los reportados en el contexto escolar, mostraron un comportamiento favorable de las variables psicológicas objeto de estudio tras la intervención basada en la Educación Deportiva con nadadores, lo que da indicios sobre su idoneidad también en el contexto federativo (AU)

The practical applications of Sport Education in the school context are fully known in the research of the last twenty years. However, it is not reported its effects on extracurricular or sporting context but also in sports with technical dominance as swimming. A pilot study with quasiexperimental design was performed in youth swimmers (n=24) of different categories (junior and youth). The intervention program based on the Sport Education, consisted of 16 training sessions. By analyzing the variables under study (Perceived Autonomy Support, Enjoyment and Perceived Competence, and Sport Commitment) statistically significant improvements were observed. Such behavior was further reinforced when designing a structural equation model in which it was hypothesized that perceived autonomy support positively predicts the enjoyment and perceived competence, and the sport commitment of the swimmers. Interviews and diary coaches’ logs were analyzed by NVivo10 software to know the perception of swimmers (responsibility, technical learning and involvement) and coaches (teamwork, communication and willingness). The main results (consistent with the school context ones) showed an optimal behavior of the psychological variables of this study after the Sport Education intervention. This reinforces the benefits of Sport Education also in the youth sport context (AU)

As aplicações práticas da Educação Desportiva no contexto escolar são totalmente conhecidos e estão presentes em inúmeras investigações. No entanto, não se sabe qual o efeito do contexto esportivo em desportes ou domínio técnico, é a natação. Portanto, um estudo piloto com desenho quase-experimental foi realizada em nadadores federados (n=24) de diferentes categorias (bebê, juvenil e infantil). O programa de intervenção com base na Educação Desportiva, consistiu em 16 sessões de treinamento. Ao analisar as variáveis em estudo (apoio autonomia percebido; Grau de satisfação e percepção de competência, e grau de compromisso esporte) estatisticamente foram observadas melhorias significativas. Tal comportamento foi reforçado quando a concepção de um modelo de equações estruturais em que foi levantada a hipótese de que o apoio autonomia percebida prediz positivamente o grau de satisfação e percepção de competência e, portanto, o grau de comprometimento do esporte de jovens nadadores. Além disso, foram analisadas entrevistas com nadadores e treinador diária por software NVivo10. Assim, os principais indicadores sobre a percepção dos nadadores (responsabilidade, de aprendizagem técnica e envolvimento) e treinador (trabalho em equipe, comunicação e vontade) se encontraram. Os resultados mostraram o bom desempenho das variáveis psicológicas do estudo, após a aplicação da Educação Desportiva, no âmbito federal (natação); sendo consistente com os resultados anteriormente encontrados no contexto escolar (AU)