Differentiated Perceived Exertion and Self-Regulated Wheelchair Exercise

OBJECTIVE. To investigate the utility of the differentiated rating of perceived exertion (RPE) for the self-regulation of submaximal wheelchair propulsion in novice users. DESIGN. Each participant completed a submaximal incremental test and a graded test to exhaustion to determine peak oxygen consumption (Vo2peak) on a wheelchair ergometer. On a separate day, two 12-minute intermittent bouts consisting of three 4-minute stages were completed at individualized imposed power outputs equating to light (40% Vo 2peak) and moderate (60% Vo2peak) intensity exercise. On a third occasion, participants were assigned to either the overall group or the peripheral group and were required to self-regulate 12-minute intermittent exercise according to either overall RPE or peripheral RPE reported during the corresponding imposed intensity trial. SETTING. Laboratory facilities at a university. PARTICIPANTS. Preliminary population of able-bodied participants with no prior experience of wheelchair propulsion (N=18). INTERVENTIONS. Not applicable. MAIN OUTCOME MEASURES. Differences in oxygen consumption (V̇o2), heart rate, blood lactate concentration, and power output between the imposed and self-regulated exercise trials. RESULTS. No difference was found in physiological responses between the moderate-intensity imposed and RPE-regulated trials in the peripheral group, whereas a significant (P<.05) underproduction in V̇o2 (1.76±.31 vs 1.59±.25L/min) and blood lactate concentration (2.8±0.90 vs 2.21±.83mmol/L) was seen in the overall group. In contrast, a significant (P<.05) overproduction was seen in the peripheral group at a light exercise intensity, whereas no difference was found between all variables during the light-intensity imposed and RPE-regulated trials in the overall group. CONCLUSIONS. Peripheral RPE enabled a more precise self-regulation during moderate-intensity wheelchair exercise in novice users. In contrast, overall RPE provided a more accurate stimulus when performing light-intensity propulsion

Ducks, Dolphins, and Portrait Medallions: Framing the Achilles Mosaic at Pedrosa de la Vega (Palencia)

The frame is often perceived as parergonal or secondary compared with the image it enframes. However, in the large fourth century Achilles on Skyros mosaic at Pedrosa de la Vega, in Northern Spain, the border framing the emblema has a unique design: portrait medallions are suspended from the spread wings of antithetical duck-dolphins, which flank a golden amphora, hanging from a ribbon held in their beaks. The article discusses the meaning of the frame with particular attention to the portrait medallions and traces the decorative scheme back to early imperial Rome

Likeness and Icon: The Imperial Couples in Hagia Sophia

The two imperial panels in the south gallery of Hagia Sophia in Constantinople are exceptional as they are the only large-scale 11th- and 12th-century images of rulers preserved in the capital city. One depicts Zoe and Constantine Monomachos, the other John Komneos and Irene. The present article reviews the mosaics mainly from the point of view of portraiture: how does the visual portrayal of imperial figures comply with the contemporary verbal description, foremost Michael Psellos’ descriptions of Zoe and her three husbands, and Anna Komnene’s portrayals in the Alexias. How did artists distinguish between imperial likeness and holy icon when portraying both within the same space? Another problem addressed is the refashioning of the Zoe panel