A fluid dynamic investigation of the Big Blade and Macon oar blade designs in rowing propulsion

The purpose of this investigation was to examine the fluid dynamic characteristics of the two most commonly used oar blades: the Big Blade and the Macon. Scaled models of each blade, as well as a flat Big Blade, were tested in a water flume using a quasi-static method similar to that used in swimming and kayaking research. Measurement of the normal and tangential blade forces enabled lift and drag forces generated by the oar blades to be calculated over the full range of sweep angles observed during a rowing stroke. Lift and drag force coefficients were then calculated and compared between blades. The results showed that the Big Blade and Macon oar blades exhibited very similar characteristics. Hydraulic blade efficiency was not therefore found to be the reason for claims that the Big Blade could elicit a 2% improvement in performance over the Macon. The Big Blade was also shown to have similar characteristics to the flat plate when the angle of attack was below 90 degrees , despite significant increases in the lift coefficient when the angle of attack increased above 90 degrees . This result suggests that the Big Blade design may not be completely optimized over the whole stroke.     

The human genome and sport, including epigenetics and athleticogenomics: a brief look at a rapidly changing field

Since Hugh Montgomery discovered the first of what are now nearly 200 "fitness genes", together with rapid advances in human gene therapy, there is now a real prospect of the use of genes, genetic elements, and/or cells that have the capacity to enhance athletic performance (to paraphrase the World Anti-Doping Agency's definition of gene doping). This overview covers the main areas of interface between genetics and sport, attempts to provide a context against which gene doping may be viewed, and suggests a futuristic legitimate use of genomic (and possibly epigenetic) information in sport.     

Guidelines for early admission to elementary school

An early admission procedure is the first step in adjusting formal educational programming to meet the educational, social, and emotional needs of intellectually advanced children. In view of the benefits to the child and potential benefits to society of meeting the intellectually advanced child's needs, it is important that school systems establish early admission policies. This article presents 12 guidelines for processing an early admission applicant.     

Assessment of mentally retarded children with the Matrix Analogies Test-Short Form,Draw A Person: A quantitative scoring system,and the Kaufman Test of Educational Achievement

This study examined the utility of the MAT-SF and the DAP: A Quantitative Scoring System as screening instruments for mental retardation. In this study, 46 normals and 39 developmentally handicapped (DH) 4th- and 5th-grade students were group administered both screening tests and individually administered an achievement test, the KTEA. The results found the MAT-SF to correlate significantly with all areas of achievement for both groups, whereas the DAP did not correlate significantly with any areas of achievement for the normal group but correlated significantly with math, but not reading, for the developmentally handicapped students. The results support the use of the MAT-SF as a screening instrument for mental retardation, whereas the usefulness of the DAP is not as clear.     

Coordination of perspective by sixth graders and teacher trainees

Sixth grade students were compared by sex for their performance on two perspective coordination tasks. Responses were compared with understanding of the principle that still water remains invariantly horizontal. Forty-eight randomly selected sixth grade students (24 girls and 24 boys) and 12 college women were individually shown a standardized three-dimensional scene. While seated in a single position, subjects completed two tasks: (1) selecting from a set of 12 pictures (displayed together) the one which could be seen from each of eight positions marked on the displayed scene and (2) choosing the positions from which could be seen eight of the 12 pictures (shown one at a time). Four of the 12 pictures were mirror images which were impossible views. Males outperformed females on both of the coordination-of-perspective tasks. For both males and females, choosing the place was more difficult than choosing the picture. Strong relationships were found between understanding of horizontality and performance on the perspective tasks. Selection of mirror images (impossible views) indicated more understanding of perspective than other, less systematic errors. Finally, female teacher trainees performed only marginally better than sixth grade students, suggesting possible remediation needs.     

Estimating fat-free mass in elite-level male rowers: a four-compartment model validation of laboratory and field methods

The purpose of this study was to investigate the accuracy of fat-free mass (FFM) estimates from two-compartment (2C) models including air displacement plethysmography (ADP), ultrasound (US), near-infrared interactance (NIR), and the Jackson and Pollock skinfold equation (SKF) against a criterion four-compartment (4C) model in elite male rowers. METHODS: Twenty-three elite-level male rowers (mean± SD; age 24.6 ± 2.2 years; stature: 191.4 ± 7.2 cm; mass: 87.2 ± 11.2 kg) participated in this investigation. All body composition assessments were performed on the same day in random order, except for hydrostatic weighing (HW), which was measured last. FFM was evaluated using a 4C model, which included total body water from bioimpedance spectroscopy, body volume from HW, and total body bone mineral via dual-energy X-ray absorptiometry. The major findings of the study were that the 2C models evaluated overestimated FFM and should be considered with caution for the assessment of FFM in elite male rowers. Future studies should use multiple-compartment models, with measurement of TBW and bone mineral content, for the estimation of FFM.