ABSTRACT
The exploitation of forage fish species can modify the functioning of marine ecosystems potentially impacting the population status of predators. This may be the case for the western Mediterranean Sea, where a reduction in the biomass of two key pelagic forage fish (European anchovy Engraulis encrasicolus and European sardine Sardina pilchardus) could produce a change in the diet composition of their main predators, which would consume alternative preys or change the size of the prey consumed. Here, we aimed to investigate the potential effect of biomass reduction of sardine and anchovy in the western Mediterranean Sea on the trophic preferences of the little tunny (Euthynnus alletteratus), a medium-sized predator that present a high consumption of these forage fish. We compared its interannual trophic ecology by combining the analysis of stomach contents and stable isotopes. Specifically, we examined if the diet of little tunny changed in its main trophic habits (diet composition, prey size, and trophic niche) during a 6-year period. We found that small pelagic fish, especially clupeiformes, were the most important prey group for the little tunny during the study period. However, we found changes in the body size of anchovy and the relative importance of sardine in recent years, probably reflecting the reported reduction in the biomass and body size of these two forage fish in the study area. In addition to these changes, we found an increase in some demersal and benthopelagic species in the diet of little tunny, which could act as an alternative diet resource.
Subject(s)
Ecosystem , Fishes , Animals , Ecology , Food Chain , Mediterranean Sea , SeafoodABSTRACT
Laterality is a key aspect of the analysis of basic and specific motor skills. It is relevant to sports because it involves motor laterality profiles beyond left-right preference and spatial orientation of the body. The aim of this study was to obtain the laterality profiles of young athletes, taking into account the synergies between the support and precision functions of limbs and body parts in the performance of complex motor skills. We applied two instruments: (a) MOTORLAT, a motor laterality inventory comprising 30 items of basic, specific, and combined motor skills, and (b) the Precision and Agility Tapping over Hoops (PATHoops) task, in which participants had to perform a path by stepping in each of 14 hoops arranged on the floor, allowing the observation of their feet, left-right preference and spatial orientation. A total of 96 young athletes performed the PATHoops task and the 30 MOTORLAT items, allowing us to obtain data about limb dominance and spatial orientation of the body in the performance of complex motor skills. Laterality profiles were obtained by means of a cluster analysis and a correlational analysis and a contingency analysis were applied between the motor skills and spatial orientation actions performed. The results obtained using MOTORLAT show that the combined motor skills criterion (for example, turning while jumping) differentiates athletes' uses of laterality, showing a clear tendency toward mixed laterality profiles in the performance of complex movements. In the PATHoops task, the best spatial orientation strategy was "same way" (same foot and spatial wing) followed by "opposite way" (opposite foot and spatial wing), in keeping with the research assumption that actions unfolding in a horizontal direction in front of an observer's eyes are common in a variety of sports.
ABSTRACT
The present study analyzes individual and group heart rate responses in exercising adult women. The specific aim was to compare responses during routine workout sessions within a community exercise program with responses during a purpose-designed workout session targeting diverse motor skills. Sixty-seven adult women with a mean ± SD age of 65.1 ± 11.7 years participated in the study. Two representative sessions were analyzed: a standard workout session the women took at the local community center and an ad hoc session designed to build on a variety of motor skills and capabilities. Observational methodology was used to collect categorical data on motor skill performance during each session using the OSMOS-in context observation instrument. Continuous heart rate data were recorded for all participants during each session. A combined analysis of categorical and continuous data was undertaken using Hidden Markov Models. The results show that the session targeting a greater diversity of motor skills not only met the cardiovascular fitness recommendations of the American College of Sports Medicine, but resulted in greater individual variability and greater synchrony between participants than the routine session (AU)
El presente estudio analiza las respuestas individuales y de grupo de la frecuencia cardiaca de mujeres adultas mientras realizan actividad física. El interés de este estudio recae en comparar como estas respuestas varían entre sesiones de ejercicio rutinario y sesiones que incluyen variedad de habilidades motrices. Participaron 67 mujeres adultas (edad 65.1 ± 11.7) usuarias de programas de actividad física municipales. Analizamos dos sesiones representativas: una estándar de los propios programas de actividad física que realizan y otra diseñada ad hoc con variedad de diversos tipos de habilidades y capacidades motrices. Utilizamos la metodología observacional para obtener datos categóricos de las habilidades motrices realizadas en cada sesión a partir del instrumento de observación OSMOS-in context. Los datos continuos obtenidos de la frecuencia cardíaca individual de cada participante se midieron mediante monitorización en cada sesión. El análisis conjunto de ambos tipos de datos, categóricos y continuos, se realizó mediante la aplicación de Cadenas Ocultas de Markov (HMM). Los resultados obtenidos consideramos que son bastante relevantes puesto que indican que la sesión que aporta mayor riqueza motriz no solo muestra una mayor adecuación cardíaca a la intensidad del ejercicio (según las recomendaciones del American College of Sports Medicine) sino una mayor variabilidad individual, incluso una mayor sincronización entre todas las participantes con respecto a la sesión estándar propia de los programas de actividad física que realizan asiduamente (AU)
