Seasonal and age-related changes in the micro-anatomy of the prostate gland of the Subantarctic fur seal, Arctocephalus tropicalis

The prostate glands of male Subantarctic fur seals Arctocephalus tropicalis, taken at Gough Island (40°20'S, 09°54'W) between November 1977 and October 1978, were examined. Significant changes in the mass of the prostate, the diameter of the alveoli and height of the secretory epithelium precede the breeding season and support the fact that A. tropicalis is a seasonal breeder. Peak activity of the prostate is reached during November-January. We propose that seasonal changes in the prostate gland, and in male reproductive activity in general, may be cued by changing photoperiod. Micro-anatomical features of the prostate of the male Subantarctic fur seal differ between different age groups. Peak prostate mass, alveoli diameter and secretory cell height indicate that Subantarctic fur seal males reach full adulthood at 10–11 years of age

Die antropometriese sprongitem-prestasiedeterminante van jong dogtergimnaste

The purposes of this study were firstly to determine the anthropometric variables that differ significantly (p ≤ 0.05) between successful and less successful young, South-African (SA), female gymnasts in the vault item and secondly, to determine the anthropometric variables that contribute to the performance of young SA female gymnasts in the vault item. Twelve young, female gymnasts (13.39 +- 2.14 years) from a gymnastics club in the North-West Province of South Africa participated in this study. Only gymnasts who participated at level 6-9 and junior as well as at the senior Olympic level were selected to participate in this study. Sixty-one anthropometric variables were measured on the dominant side of the body according to the methods of Norton et al. (1996). Independent t-tests and effect sizes revealed that the gymnasts who obtained the highest points (top 5) during the execution of the vault item during the South African Gymnastics Championships had statistical and practical significantly larger relaxed and flexed upper arm, wrist and ankle circumferences as well as higher mesomorphy values than the less successful gymnasts. The cluster analysis-reduced variables were used to perform a forward, stepwise multiple regression analysis, which showed that flexed upper arm circumference (53.93%), midstillion dactillion length (12.38%), foot length(11.50%), fat percentage (8.93%), trochanterion-tibial lateral length (5.77%), chest circumference (3.69%), ectomorphy (1.96%), bideltoied breadth (1.54%), triceps skinfold (0.23%) and iliospinal box height (0.07%) contributed 100% to the variance in gymnasts’ vault performances. Therefore the conclusion that can be drawn is that larger upper arm and upper body circumferences; hand, foot, upper leg and total leg lengths; triceps skinfold and fat percentage as well as a higher ectomorphy value are important anthropometric vaulting performance determinants for young, South African, female gymnasts and should be included in the sport-scientific testing protocols of gymnasts.Key words: Gymnastics; Vault; Anthropometry; Performance; Female; Girls

Die antropometriese vloeritem-prestasiedeterminante van jong dogtergimnaste

The purposes of this study were firstly, to determine the anthropometric variables that differ significantly (p 0.05) between successful and less successful young, South-African female gymnasts who participate in the floor item and secondly, to determine the anthropometric variables that contribute to the floor item performance of those gymnasts. Twelve young, female gymnasts (13.39 ± 2.14 years) from a gymnastics club in the North-West Province of South Africa participated in the study. Only gymnasts who participated at level 6-9 and junior as well as senior Olympic level were selected to participate in the study. Sixty-one anthropometric variables were measured on the dominant side of the body according to the methods of Norton et al. (1996). Independent t-tests revealed that the gymnast who obtained the highest marks (top 5) during the execution of the floor item during the South African Gymnastics Championships had statistical and practical significantly larger relaxed and flexed upper arm, wrist and ankle circumferences as well as mesomorphy values than the less successful gymnasts. The cluster analysis-reduced variables were used to perform a forward, stepwise multiple regression analysis which showed that bi-trochanterion (34.86%), femur (17.07%) and bi-deltoid breadth (4.93%); front thigh skinfold (19.71%); fat percentage (7.68%); acromialradial (4.09%) and foot length (0.05%) as well as waist (6.68%), chest (2.92%) and gluteal thigh circumference (2.02%) contributed 100% to the variance in gymnasts’ floor performances. The contributions of bi-trochanterion breadth, femur breadth, gluteal thigh circumference and foot length to floor-gymnastic performance were significant. Only gluteal thigh circumference showed a negative relationship with floor-gymnastic performance. The conclusion that can therefore be drawn is that larger limb and torso circumferences, waist breadths, fat percentages and front thigh skinfolds, as well as upper arm and foot lengths are important anthropometric floor performance determinants for young, South African female gymnasts and should be included in the sports-scientific testing protocols of gymnasts.Key words: Gymnastics; Floor; Anthropometry; Performance; Females; Girls