Search Results - (Author, Cooperation:R. J. Watts)

2012-07-18

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Aging/*genetics ; Alleles ; Alzheimer Disease/*genetics/pathology/physiopathology/prevention & control ; Amyloid Precursor Protein Secretases/metabolism ; Amyloid beta-Protein Precursor/chemistry/*genetics/*metabolism ; Aspartic Acid Endopeptidases/metabolism ; Cognition/physiology ; Cognition Disorders/*genetics/*physiopathology/prevention & control ; Genetic Predisposition to Disease ; HEK293 Cells ; Humans ; Mutation/*genetics ; Plaque, Amyloid/genetics/metabolism

1432-0703

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Medicine

Abstract. Acute and chronic toxicity tests were conducted on the herbicide benzofenap (Taipan® 300) using two Australian freshwater invertebrates. The commercial formulation of benzofenap and a blank formulation containing only the adjuvants of Taipan® 300 were tested against final instar larvae of the midge Chironomus tepperi and adults of the aquatic snail Isidorella newcombi. In 24-h acute bioassays the midge larvae did not show significant mortality at a nominal concentration of 1.2 mg/L active ingredient (AI), double the maximum notional concentration expected in rice fields after application of Taipan® 300 at the permit rate of 2 L/ha. No significant snail mortality was recorded in acute bioassays (24-h exposure, 48-h recovery) at nominal concentrations up to 76 mg/L AI, which is over 120 times the maximum notional field concentration. In chronic assays, the pupation and emergence of C. tepperi was monitored after a 4-h pulse exposure of final instar larvae to Taipan® 300 (nominal concentrations 0.001 to 0.1 mg/L AI) and adjuvant-only (0.1 mg/L equivalent) treatments. No statistically significant effects were observed, although emergence appeared to be delayed by higher benzofenap concentrations and by the adjuvant-only treatment. During snail bioassays, egg and feces production were monitored for 21 days after 24-h exposure to Taipan® 300 (nominal concentrations 1.2 mg/L to 60 mg/L AI) and adjuvant-only treatments (60 mg/L equivalent). No significant chronic effects were proven against I. newcombi, despite a decline in egg mass production following exposure to all treatments and a reduction in the total numbers of eggs produced at the highest nominal concentrations tested (60 mg/L AI and adjuvant-only treatments). Similarly, feces production by snail pairs exposed to the majority of treatments declined, but these differences were not statistically significant. It is concluded that Taipan® 300 does not represent a significant risk to mature C. tepperi larvae or adult I. newcombi in downstream environments when applied to rice fields at the permit rate of 2 L/ha.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract The atherinid fish Craterocephalus capreoli Rendahl is abundant in the Houtman Abrolhos Islands, 70 km off the Western Australia coast and ≃250 km south of the southern limit of the range of the species along the mainland. Electrophoretic examination of 7 allozyme loci at 17 sites in the Houtman Abrolhos revealed a substantially lower level of polymorphism than found in an earlier study of the species in its mainland distribution, with many of the uncommon alleles and some common ones missing. There is a very high degree of genetic subdivision among the populations in the Houtman Abrolhos, measured by a mean F ST of 0.437 over a distance of 35 km. This F ST (standardized variance in allelic frequencies) is six times that found previously among populations along the mainland coast over distances up to 850 km. The subdivision of populations in the Houtman Abrolhos is similar within one island group on a scale up to 12 km, and between two groups that are separated by 15 km of deep water. Significant differences in allelic frequencies were found between populations from the open shore and enclosed lagoons less than 800 m apart, but the overall levels of subdivision were similar for the two types of environment. Previous work had shown high levels of genetic subdivision in the Houtman Abrolhos for a gastropod with direct development. The results for C. capreoli demonstrate that the archipelago favours subdivision even for a species with potentially much greater mobility and different life history.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract Enzyme polymorphisms in the sea urchinEchinometra mathaei were examined to test the relative influences of population turnover and patchiness in recruitment on genetic heterogeneity. We found that the total variance in allelic frequency among three populations separated by approximately 4 km at Rottnest Island, Western Australia (collected in February 1985) is as large as that among five additional samples collected over a distance of 1 300 km along the Western Australian coast in August 1987. This suggests that the forces causing genetic differentiation act on a local scale and occur in a single generation. A comparison of sites with different histories of recruitment indicates that the observed genetic differences among age groups are the result of prerecruitment effects, and that differences among sites reflect their individual histories of recruitment.

Electronic Resource