77823 research outputs found
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Cálculo de una caja de cambio de una Ducati Panigale V4 R.
Full text linkCálculo y comprobación de una caja de cambios para una Ducati Panigale V4 R usada en el campeonato mundial de SuperBikes, se pretende comprobar que la caja es apta para un número determinado de fines de semana de carreras, esto incluye los entrenamientos libres, la sesión de clasificación y las carreras que puedan haber durante el mismo.<br /
Playgrounds de Aldo Van Eyck. Los espacios de juego, análisis e impacto actual
Full text linkA finales de la década de 1940, durante la reconstrucción de las ciudades después de la Segunda Guerra Mundial, el arquitecto Aldo van Eyck inició un proyecto urbano que se desarrolló durante treinta años en Ámsterdam. Este proyecto consistió en la creación de más de 700 parques infantiles que se integraban en los espacios urbanos, y ofrecían un entorno de juego libre con elementos simples que fomentaban el crecimiento imaginativo y físico de los niños. Este Trabajo Fin de Grado se centra en estos parques infantiles concebidos por Aldo van Eyck en Ámsterdam. La investigación aborda el diseño de los parques de juego desde una perspectiva global, estudiando sus inicios, hasta llegar al proceso de diseño y construcción de los playgrounds de Van Eyck. Se propone el estudio de la obra de Aldo Van Eyck acompañado de un análisis de los elementos empleados en cada uno de ellos. Para llegar a compararlos con los parques de juego de la actualidad, cómo han evolucionado y el legado que han dejado. Otro objetivo relevante es poner en valor esta figura tan importante en los centros urbanos, ya que forman una parte esencial del desarrollo infantil. En la actualidad, la utilización de áreas de juego infantiles ha experimentado cambios debido a la constante evolución en la forma de educación y entretenimiento de los niños, debido en parte, a la llegada de la tecnología. Como resultado, la práctica del juego libre, que históricamente ha sido un escenario fundamental para el desarrollo de los niños, está experimentando un declive progresivo.<br /
Cursus honorum: pathways to rank and power in the Roman Republic
Full text linkThis volume addresses a crucial issue for the political culture of the Roman Republic: competition among individuals and families of the social elite. This rivalry came to head at the annual elections of new magistrates: every year, a number of candidates ran for office and whereas some obtained sufficient votes from the people, others were defeated. The political career of a Roman citizen therefore took the shape of a hierarchical ladder (cursus honorum) whose rungs corresponded to the age at which one or other magistracy was attained. The book deals with the position of the cursus honorum in Republican history, reflects on the way scholarship has constructed its political and social significance for the political culture of the period, and discusses questions relating to how Roman citizens pursued different political careers. The outcome is a roundbreaking and essential contribution to a better understanding of the Roman Republic
Analysis of the Predictive Value of Motor Coordination, Anxiety and Self‐Esteem Levels on Self‐Perceived Motor Competence in Primary Students
No full textABSTRACT Motor, psycho‐emotional, cognitive and social variables, plus other factors like gender, influence how schoolchildren perceive their motor competence level. By means of a hierarchical linear regression analysis, this longitudinal study aimed to determine the predictive value that coordination, anxiety, and self‐esteem at the age of 9 years can have on the self‐perceived motor competence variable at the age between 11 and 12 years. Data collection was performed with 224 pupils at a first time point with grade‐4 Primary Education (PEd) pupils (mean age 9.11 ± 0.32 years) and a second time point with grade‐6 PEd pupils (11.49 ± 0.50 years). The results evidenced that coordination, anxiety, and self‐esteem at the age of 9 years predicted self‐perceived motor competence at ages between 11 and 12 years. Gender differences were also observed in these results. For the female gender, age, coordination, and anxiety variables explained the variance for self‐perceived motor competence. For the male gender, age, coordination, and self‐esteem explained the variance for self‐perception competence. This reveals the importance of more globally understanding self‐perceived motor competence in PEd pupils considering the predictive role of psycho‐emotional, motor, and socio‐demographic variables based on gender
Validation of the brief scale on ageism in university students (BSAUS)
Full text linkThis study validates the Brief Scale on Ageism in University Students (BSAUS) to support educational objectives for reducing negative biases towards older adults. Using a quantitative methodology with inferential analysis and second-generation techniques, the study verified the factorial structure and psychometric properties of the BSAUS. Cross-sectional surveys were conducted with 1,347 students from the Universities of Valladolid, Lleida, and Zaragoza between 2018/19 and 2022/23. Confirmatory factor analysis revealed Cronbach's alpha values of 0.76 and 0.74 for the Ageism construct, while Wellbeing, Behavioural, and Personality dimensions scored 0.70–0.66, 0.55, and 0.58–0.60, respectively. Composite reliability exceeded the 0.7 criterion across measures. The BSAUS, comprising three dimensions, is validated as a reliable tool for assessing discrimination, prejudices, and stereotypes towards older adults in university contexts. This scale has potential for ageism reduction initiatives and can inform strategies to prevent discriminatory behaviour towards older adults
Effects of Ultrasound-Guided Percutaneous Neuromodulation on Shoulder Muscle Strength in CrossFit Athletes: A Pilot Randomized Controlled Trial
No full textBackground
CrossFit integrates diverse functional movements to optimize overall fitness, with muscle strength training being a core component. Ultrasound-guided percutaneous neuromodulation (US-guided PNM) has emerged as a potential adjunct to enhance muscle strength gains; however, its efficacy in the upper limb in healthy individuals remains unexplored.
Objective
This study evaluated the efficacy of two US-guided PNM protocols (three sessions and one session) targeting the axillary and suprascapular nerves in improving shoulder muscle strength in healthy CrossFit athletes.
Materials and Methods
A pilot, randomized, controlled, single-blind clinical trial was conducted with 39 healthy CrossFit athletes randomly allocated to one of three groups: control (G1, no intervention), one session of US-guided PNM (G2), or three sessions of US-guided PNM (G3). Shoulder muscle strength was assessed using a hand-held dynamometer to measure external and internal rotation muscle strength at various shoulder positions before each treatment session (days 1, 7, and 14) and one week after the last session (day 21). Moreover, the one-repetition maximum (1RM) shoulder press exercise was evaluated on day 1 and day 21.
Results
No statistically significant differences were observed among groups for any outcome. However, the within-group analysis indicated statistically significant improvements over time in the treated limbs of intervention groups (G2 and G3), whereas no statistically significant changes were observed in the control (G1) or the untreated limbs of G2 and G3. The improvements were more consistent for shoulder strength measured in the neutral position than at 90° abduction.
Conclusions
Although US-guided PNM did not yield significantly greater improvements than did the control group, both one and three sessions targeting the axillary and suprascapular nerves enhanced rotational shoulder muscle strength in treated limbs and 1RM shoulder press performance. These findings should be interpreted with caution, and further investigation is warranted, particularly in populations with lower baseline strength and in exploring varied application parameters to optimize efficacy
Performance and Emissions of Spark-Ignition Internal Combustion Engine Operating with Bioethanol–Gasoline Blends at High Altitudes Under Low- and High-Speed Conditions
Full text linkSeveral countries have cities located at elevations above 2000 m. Consequently, the internal combustion engines (ICEs) that operate there do not achieve the desired performance and emissions under these atmospheric conditions. One approach to mitigate these effects and, at the same time, address climate change is the use of biofuel–fossil fuel blends. However, ICEs must operate under a wide range of rpm to meet varying workload demands, raising concerns that these fuel blends may not be fully effective in achieving the desired performance and emission outcomes under such conditions. To address this issue, a series of experimental tests were conducted at low and high rpm of a spark-ignition (SI) ICE fuelled with bioethanol–gasoline blends in the ratios of E10, E15, E20, E40, E60, E85, and E100. The tests were conducted at 2600 m above sea level (masl) under various engine loads. The E20 and E40 blends showed outstanding performance at 2700 rpm, achieving high brake power and low emissions of CO2 and HCs. At 4300 rpm, the E40 blend exhibited great performance because the engine produced high brake power and low emissions of CO and NOx. Based on these results, it can be concluded that bioethanol concentrations of between 20 and 40% in the blend effectively compensate for the reduced atmospheric oxygen at high altitudes, enhancing the combustion process in SI-ICEs
External load of soccer players in the moments before and after a goal
Full text linkIntroduction: Research has explored factors linked to scoring goals in soccer, but little is known about teams' external load when a goal occurs.
Objective: This study aimed to analyze differences in external load before and after a goal, depending on whether it was scored or conceded.
Methodology: The research focused on a Spanish youth semi-professional soccer team. The study examined player movement dynamics before (Pre5 and Pre10) and after (Post5 and Post10) goals were scored, using the minute of the match as a reference point. Data were collected on various performance metrics including total distance (DC), DC at high-speeds, player load (PL), accelerations (Acc2-3 & Acc>3) and decelerations (Dec2-3 & Dec>3).
Results: Regardless of the goal was conceded of scored, DC, PL, Acc2-3, and Dec>3 decreased at Post10 compared to Post10 (p3 at Post5 vs. Pre5 (p< 0.029). When scoring, DC and Dec2-3 decreased in Post5 vs. Pre5 (p< 0.049), while when conceding, DC was lower at Post10 vs. Pre10 (p= 0.017).
Discussion: The external load of soccer players decreases when goal happens during the game. The number of studies comparing players' running responses after goals is scarce, highlighting the need for more research to analyze players' running activity once the goal occurs.
Conclusions: Once a team scores, it can be inferred that they have achieved their aim and that they may adopt a more conservative strategy, reducing their efforts.
Introducción: La investigación ha explorado factores relacionados con la aparición del gol en fútbol. Sin embargo, se sabe poco sobre la carga externa de los equipos cuando ocurre un gol.
Objetivo: El objetivo del estudio fué analizar las diferencias en la actividad mecánica de jugadores de fútbol antes y después de un gol, dependiendo de si fue anotado o recibido.
Metodología: La investigación se centró en un equipo semiprofesional de futbol español. El estudio examinó las dinámicas de movimiento de los jugadores antes (Pre5 y Pre10) y después (Post5 y Post10) del gol, utilizando el minuto del partido como punto de referencia. Se recopilaron datos sobre diversas métricas de carga externa, como la distancia total (DC), DC a alta velocidad, Player load (PL), aceleraciones (Acc2-3 y Acc>3) y desaceleraciones (Dec2-3 y Dec>3).
Resultados: Independientemente de si el gol fue anotado o recibido, DC, PL, Acc2-3 y Dec>3 disminuyeron en Post10 en comparación con Pre10 (p3 en Post5 vs. Pre5 (p< 0.029). Al anotar un gol, DC y Dec2-3 disminuyeron en Post5 vs. Pre5 (p< 0.049), mientras que al recibir un gol, la DC fue menor en Post10 vs. Pre10 (p= 0.017).
Discusión: La carga externa de los futbolistas disminuye tras la ocurrencia de un gol. Existe una falta de investigación que compare las respuestas de carrera de los jugadores después de los goles, lo que destaca la necesidad de más investigación.
Conclusiones: Tras anotar un gol, los jugadores pueden entender que se ha alcanzado el objetivo, esto puede adoptar una estrategia más conservadora, reduciendo sus esfuerzos de desplazamiento
Quantitative characterization of the 3D self-organization of PDAC tumor spheroids reveals cell type and matrix dependence through advanced microscopy analysis
Full text linkPancreatic ductal adenocarcinoma (PDAC) is characterized by an abundant tumor-associated stroma composed from pancreatic stellate cells, which play a critical role in tumor progression. Developing accurate in vitro models requires understanding the complex interactions between tumor cells and their microenvironment. In this study, we present a quantitative imaging-based characterization of the three dimensional (3D) self-organization of PDAC tumour spheroids using a microfluidic platform that mimics key aspects of the tumor microenvironment. Our model incorporates collagen type I hydrogels to recreate the extracellular matrix, activated human pancreatic stellate cells (HPSCs), and various tumor cell types. Advanced imaging techniques, including Lattice Lightsheet Microscopy, allowed us to analyze the 3D growth and spatial organization of the spheroids, revealing intricate biomechanical interactions. Our results indicate that alterations in matrix properties—such as stiffness, pore size, and hydraulic permeability—due to variations in collagen concentration significantly influence the growth patterns and organization of PDAC spheroids, depending on tumor subtype and epithelial–mesenchymal phenotype. Higher collagen concentrations promoted larger spheroids in epithelial-like cell lines, while mesenchymal-type cells required increased collagen for self-organization into smaller spheroids. Furthermore, coculture with HPSCs affected spheroid formation distinctly based on each PDAC cell line's genetic and phenotypic traits. HPSCs had opposing effects on epithelial-like cell lines: one cell line exhibited enhanced spheroid growth, while another showed inhibited formation, whereas mesenchymal-like spheroids showed minimal impact. These results provide insights into tumor–stroma interactions, emphasizing the importance of the cell-specific and matrix-dependent factors for advancing our understanding of PDAC progression and informing future therapeutic strategies
Adopting the euro does not work without political integration
No full textA new empirical exercise for dealing the effects of monetary unions on welfare is developed. The estimates of the effects of adopting the euro using a sample of 216 countries for the 1960–2021 period apply a novel multiple-period differences-in-differences approach. They show a significant and robust negative effect on economic growth of adopting the euro, mainly for the countries with the highest income inequality