21 research outputs found

    Structures associated with feeding in three broad-mouthed, benthic fish groups

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    The flatheads, toadfishes, and goosefishes discussed here hold certain features in common. All are bottom-living forms with depressed head areas and broad gapes, and all eat large food items: fishes and/or crabs. All have developed structural specializations in association with this diet. The three groups are at most distantly related, and their feeding specializations are different and have evolved from different bases. In flatheads the combination of large food items and depressed head regions seems to have led to the separation of the two halves of the pelvic girdle, a feature in which they differ from their scorpaenoid relatives. Toadfish peculiarities associated with feeding are various but most notable in those that pass crabs they eat through the gape and into the mouth. Goosefish feeding is centered around the use of a lure to attract prey to within striking distance. The three fish groups are discussed separately, but their feeding structures are compared to one another in the final section of the paper.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42639/1/10641_2004_Article_BF00005053.pd

    Adaptability of Older Workers to Technological Change: Performance in Retraining

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86678/1/j.1464-0597.1962.tb00453.x.pd

    Lower Limb Kinematic and Kinetic Differences between Transtibial Amputee Fallers and Non-Fallers

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    Stair walking relies on concentric contraction of the ankle plantarflexor and knee extensor muscles, which are either absent or weakened in transtibial amputees. As a result the risk of falling is increased in this population. The aim of this study was to compare the gait patterns of transtibial amputee fallers and non-fallers during stair ascent. Eleven participants (fallers = 6; non-fallers = 5) walked along a 3-m walkway and ascended a three-step staircase with handrails, at their self-selected pace, while three-dimensional kinematic data were collected from the lower limbs. A force plate was embedded into the first step and kinetic data were measured for the intact lead limb only. The fallers walked significantly faster (p = 0.00) and exhibited less hip flexion (p = 0.05) and less anterior pelvic tilt (p = 0.04) compared to the non-fallers. The fallers had significantly greater first and second peak vertical ground reaction force (GRF) on the intact limb than the non-fallers (p = 0.05 and p = 0.01, respectively) contributing to the significantly larger ankle (p = 0.02) and hip moments (p = 0.04). These findings suggested the amputee non-fallers performed mechanically demanding tasks more cautiously. Two of the participants self-selected a ‘step to’ gait pattem, ascending one step at a time. This may be considered a compensatory mechanism for the lack of ankle mobility and functional muscle performance in these two transtibial amputees
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