No abstract

This study, with a top T-52 class athlete, determines the relationship between stroke frequency (SF) and push time (PT) and wheelchair velocity (Wv) using different handrim diameters (HD) and the effect of different HDs on the athlete's heart rate (HR) and blood lactate (LACT) at competition speeds. Wv shows a linear-direct relationship with SF but a linear-inverse relationship with PT (p < .001 in both cases). Using bigger handrims (0.37 m instead of 0.36 m), SF increases 6%, while PT decreases 27% (at 24 Km·h −1 ). HR (p < .0001) increases with Wv and is also affected by HD with differences between the 0.34 m-0.36 m handrim group (lower values) and the 0.37 m handrim (higher values). Significant interaction (p < .0001) is identified between HD and Wv. LACT results seem to follow the same direction as HR. This methodology helped the athlete to choose the optimum HD, and his achievements (some world records) indicate that HD optimization could be highly profitable in sport terms.Attaining peak performance in sports generally requires not only great care of many aspects in everyday life and an adequate planning of training but also constant work in optimizing small details that can often make the difference between real success and a good result. In wheelchair athletics, paying attention to the equipment, especially the wheelchair and its components, seems to be relevant, but research is actually more focused on mechanical efficiency in relation with the mechanical power that the athlete can produce, a great deal of which is lost (frequently more than 90%;

Low cost remote sensing imagery has the potential to make precision farming feasible in developing countries. In this article, the authors describe image acquisition from eucalyptus, bean, and sugarcane crops acquired by low-cost and low-altitude systems. They use different approaches to handle low-altitude images in both the RGB and NIR (near-infrared) bands to estimate and quantify plantation areas.