; 10.1152/ajpendo.00416.2001.-The purpose of this study was to test the hypothesis that muscle fiber type is related to obesity. Fiber type was compared 1) in lean and obese women, 2) in Caucasian (C) and African-American (AA) women, and 3) in obese individuals who lost weight after gastric bypass surgery. When lean (body mass index 24.0 Ϯ 0.9 kg/m 2 , n ϭ 28) and obese (34.8 Ϯ 0.9 kg/m 2 , n ϭ 25) women were compared, there were significant (P Ͻ 0.05) differences in muscle fiber type. The obese women possessed fewer type I (41.5 Ϯ 1.8 vs. 54.6 Ϯ 1.8%) and more type IIb (25.1 Ϯ 1.5 vs. 14.4 Ϯ 1.5%) fibers than the lean women. When ethnicity was accounted for, the percentage of type IIb fibers in obese AA was significantly higher than in obese C (31.0 Ϯ 2.4% vs. 19.2 Ϯ 1.9%); fewer type I fibers were also found in obese AA (34.5 Ϯ 2.8% vs. 48.6 Ϯ 2.2%). These data are consistent with the higher incidence of obesity and greater weight gain reported in AA women. With weight loss intervention, there was a positive relationship (r ϭ 0.72, P Ͻ 0.005) between the percentage of excess weight loss and the percentage of type I fibers in morbidly obese patients. These findings indicate that there is a relationship between muscle fiber type and obesity. adiposity; African-American; insulin resistance; morbid obesity; skeletal muscle SKELETAL MUSCLE IS A HETEROGENEOUS organ consisting of different muscle fiber phenotypes. In human skeletal muscle, histochemical staining for pH-sensitive myosin ATPase activity has revealed two major classifications of fiber type, the type I and type II fibers (3,28,31). The fast-twitch, type II fibers can be broadly categorized into type IIa and type IIb fibers, although other subclasses exist (3,29,31). The type I, or slow-twitch, muscle fibers tend to be oxidative and vascularized, whereas the type IIb fibers (fast twitch) are glycolytic in nature (28, 31). The type I fibers are also insulin sensitive compared with type II muscle (8,13,17).In humans, there can be substantial heterogeneity of muscle fiber types within a given mixed muscle group. Simoneau and Bouchard (32) concluded that, in the vastus lateralis, Ն25% of the North American Caucasian population possessed either less than 35% or more than 65% type I fibers; a range of 13-98% type I fibers has been reported (31). Several factors may be linked with such variance. We have observed that obese individuals exhibit fewer type I and more type IIb muscle fibers than lean subjects (9). Other research has reported a negative relationship between adiposity and the relative percentage of type I muscle fibers (9, 21, 36) and an increased percentage of type IIb muscle fibers in patients with type 2 diabetes (9, 23), in their insulin-resistant offspring (27), and in obese subjects (18,19,21,23). Such findings make it tempting to speculate that there is a relationship between muscle fiber composition and obesity.The purpose of the current study was to test the hypothesis that muscle fiber type is related to obesity. We tested this hypothesis in...

Please cite this article as: Dai, S., Cunningham, P.R., Marshall, S., Silva, C., Influence of fibre architecture on the tensile, compressive and flexural behaviour of 3D woven composites, Composites: Part A (2014), doi: http:// dx. AbstractThis paper presents a comprehensive study on the tensile, compressive, and flexural performance of six types of 3D woven carbon-fibre/epoxy composites which were manufactured using a traditional narrow fabric weaving loom and resin transfer moulding. Four orthogonal and two angle-interlock weaves were tested with the primary loading direction parallel to the warp direction. The mechanical performance was found to be affected by the distribution of resin rich regions and the waviness of the load-carrying fibres, which were determined by the fibre architectures. The binding points within the resin rich regions were found to be the damage initiation sites in all weave types under all loading conditions, which were confirmed with both visual observation and digital image correlation strain maps. Among all weave types, the angle interlock weave W-3 exhibited the highest properties under all loading conditions.

The large majority of trauma patients transported by both helicopter and ground ambulance have low injury severity measures. Outcomes were not uniformly better among patients transported by helicopter. Only a very small subset of patients transported by helicopter appear to have any chance of improved survival based on their helicopter transport. This study suggests that further effort should be expended to try to better identify patients who may benefit from this expensive and risky mode of transport.