Metabolic response in type I and type II muscle fibers during a 30-s cycle sprint in men and women.

The acute metabolic response to sprint exercise was studied in 20 male and 19 female students. We hypothesized that the reduction of muscle glycogen content during sprint exercise would be smaller in women than in men and that a possible gender difference in glycogen reduction would be higher in type II than in type I fibers. The exercise-induced increase in blood lactate concentration was 22% smaller in women than in men. A considerable reduction of ATP (50%), phosphocreatine (83%), and glycogen (35%) was found in type II muscle fibers, and it did not differ between the genders. A smaller reduction of ATP (17%) and phosphocreatine (78%) was found in type I fibers, and it did not differ between the genders. However, the exercise-induced reduction in glycogen content in type I fibers was 50% smaller in women than in men. The hypothesis was indeed partly confirmed: the exercise-induced glycogen reduction was attenuated in women compared with men, but the gender difference was in type I rather than in type II fibers. Fiber-type-specific and gender-related differences in the metabolic response to sprint exercise might have implications for the design of training programs for men and women.     

Genetic relationships between Nereimyra punctata and N. woodsholea (Hesionidae, Polychaeta)

We present a COI-based parsimony analysis of the relationships between the shallow water, pigmented hesionid polychaete Nereimyra punctata , and a deep-water, unpigmented form with sympatric distribution in Norway and Sweden. Apart from the pigmentation differences, the two forms exhibit no observed morphological differences. The terminals are represented by four specimens each of the two forms from the Trondheimsfjord in Norway, and four each of the two forms from northern Bohuslän in Sweden, plus members of the two hesionids Heteropodarke and Ophiodromus as outgroups. In addition, the analysis includes a topotype of the morphologically similar and unpigmented Nereimyra woodsholea from the Middle Atlantic Bight off the US east coast. The equally weighted matrix includes 132 informative characters. All most-parsimonious trees unequivocally indicate that specimens belonging to the same form (pigmented or unpigmented) from different areas are cladistically closer related to each other than different forms from the same areas. Nereimyra woodsholea is nested within the unpigmented deeper group of the Norwegian and Swedish specimens, thus indicating that this name should be applied to the deep-water form in Norway and Sweden.     

SURVIVAL OF AN UNIRRADIATED SALMONELLA TYPHIMURIUM MARKER STRAIN INOCULATED IN POULTRY FEEDS AFTER IRRADIATION

The present study was designed to compare unirradiated Salmonella typhimurium survival during storage after inoculation in either irradiated or unirradiated poultry feed. The effects of irradiation (5 kGy) on the indigenous feed microflora and on the survival of marker strain of S. typhimurium contaminated after irradiation treatment were determined during 56 days of storage of either soybean meal (SBM) or meat and bone meal (MBM) based feeds. The initial aerobic bacterial populations were reduced more than 90% in both SBM (4.96 to 4.08 ± 0.03 log₁₀ CPU/g feed) and MBM (5.12 to 3.90 ± 0.03) by irradiation. Irradiation treatment reduced the average fungal counts during 56 days of storage in both SBM (4.24 to 2.74 ± 0.03) and MBM (4.38 to 2.15 ± 0.03) containing feeds. However, unirradiated S. typhimurium populations inoculated after irradiation of the feed were not different in either irradiated or nonirradiated SBM and MBM based feeds. Therefore, the differences in fungal versus bacterial sensitivity among the feed types and storage times suggests that gamma irradiation can alter the makeup of indigenous microbial populations in feed but this does not appear to have a discernible influence on subsequent survival of unirradiated S. typhimurium added as a dry inoculum after irradiation.     

Reproductive patterns of selected understorey trees in the Malaysian rain forest: the sexual species

HA, C. O., SANDS, V. E., SOEPADMO, E. & JONG, K., 1988. Reproductive patterns of selected understorey trees in the Malaysian rain forest: the sexual species. Investigations were carried out on the floral, fruit and seed biology, and the embryology of representatives of the Sapindaceae and Bombacaceae which occur in the lower canopy of the lowland rain forest of Peninsular Malaysia. Pollination studies indicated cross-compatibility and outbreeding in all species examined, associated with self-compatibility in the polygamous monecious Pometia pinnata and Allophylus cobbe and, to a limited extent, in the effectively dioecious Xerospermum intermedium . In these sapindaceous species, together with the self-incompatible androdioecious Nephelium lappaceum , the structurally hermaphrodite flowers were determined embryologically to be functionally female with no anther dehiscence. The self-incompatible Durio griffithii of the Bombacaceae, and X. intermedium, N. lappaceum and P. pinnata were shown by embryological studies to form a sexual zygote. The observations on these outcrossing species are considered in relation to their potential for gene exchange and their contribution to the maintenance of species diversity in the lowland rain forest.