Factors influencing paternity success in Antechinus agilis: last-male sperm precedence, timing of mating and genetic compatibility

We describe the patterns of paternity success from laboratory mating experiments conducted in Antechinus agilis, a small size dimorphic carnivorous marsupial (males are larger than females). A previous study found last-male sperm precedence in this species, but they were unable to sample complete Utters, and did not take male size and relatedness into account. We tested whether last-male sperm precedence regardless of male size still holds for complete litters. We explored the relationship between male mating order, male size, timing of mating and relatedness on paternity success. Females were mated with two males of different size with either the large or the small male first, with 1 day rest between the matings. Matings continued for 6 h. in these controlled conditions male size did not have a strong effect on paternity success, but mating order did. Males mating second sired 69.5% of the offspring. Within first mated males, males that mated closer to ovulation sired more offspring, To a lesser degree, variation appeared also to be caused by differences in genetic compatibility of the female and the male, where high levels of allele-sharing resulted in lower paternity success.

Mating aggregations and mating success in the flower thrips, Frankliniella schultzei (Thysanoptera: Thripidae), and a possible role for pheromones

Aggregations of Frankliniella schultzei males were observed on the corollas of Hibiscus rosasinensis and Gossypium hirsutum flowers in southeast Queensland. Aggregations were seen only on the upper surfaces of corollas but may have occurred on other flower parts, which were hidden from view. Conspecific females entered aggregations and a small proportion of them mated [18% (n = 163), H. rosasinensis; 30% (n = 181), G. hirsutum]. Most females (87 and 72%, respectively) that did not mate in aggregations walked to other flower parts. Behavior was difficult to observe on these parts, but mating was sometimes observed there. The number of females that landed within aggregations on the upper surfaces of both H. rosasinensis and G. hirsutum corollas was highly correlated with the number of males (r = 0.88, r = 0.93, respectively; P < 0.001). Significantly more mating pairs were observed in high-density aggregations (mean +/- SE, 1.10 +/- 0.22 and 4.44 +/- 0.48, respectively) than in low-density aggregations (0.37 +/- 0.11 and 1.67 +/- 0.29, respectively) (P < 0.05) on flowers of both species. More F. schultzei females were attracted to sticky traps baited with live conspecific males set among flowering Ipomoea indica (mean +/- SE, 8.83 +/- 0.32) and G. hirsutum (10.90 +/- 0.79) plants than to control traps (0.10 +/- 0.05 and 0.70 +/- 0.25, respectively)( P < 0.05), presumably in response to male-produced pheromones. Significantly more females were attracted to traps with high male densities than to traps with low densities. We found no statistical evidence that aggregation size influenced mating success (proportion males that mated). Mating success, however, should be evaluated with respect to mating on all flower parts and not just the upper surfaces of corollas. The results of this study constitute the first behavioral evidence for an attractant sex pheromone in thrips.

Hydrolytic kinetic resolution of terminal mono- and bis-epoxides in the synthesis of insect pheromones: routes to (-)-(R)- and (+)-(S)-10-methyldodecyl acetate, (-)-(R)-10-methyl-2-tridecanone, (-)-(R)-(Z)-undec-6-en-2-ol (Nostrenol), (-)-(1R,7R)-1,7-dime

Hydrolytic kinetic resolution (HKR) of functionalised epoxides using (salen)Co(OAc) complexes provides enantiomerically enriched epoxides and diols, which have been transformed into important insect sex pheromones. In this general approach, (-)-(R)- and (+)-(S)-10-methyldodecyl acetates from the smaller tea tortrix moth were obtained, as was (-)-(R)-10-methyltridecan-2-one from the southern corn rootworm. The (S)-epoxide obtained from undec-1-en-6-yne was transformed to (-)-(R)-(Z)-undec-6-en-2-ol (Nostrenol) from ant-lions. HKR of appropriate bisepoxides was also investigated, and transformations of the resulting bisepoxides and epoxydiols provided (-)-(1R,7R)-1,7-dimethylnonylpropanoate from corn rootworms, (-)-(6R,12R)-6,12-dimethylpentadecan-2-one from the female banded cucumber beetle, and (-)-(2S,11S)-2,11-diacetoxytridecane and (+)-(2S,12S)-2,12-diacetoxytridecane from female pea-midges. (C) 2002 Elsevier Science Ltd. All rights reserved.

Racialised schooling, 'ethnic success' and Asian-Australian students

Based on discussions with Asian-Australian young women at a mixed-sex, Australia State high school, this article argues that the pro-school conformity of Asian-Australian young women sets them in a problematic and precarious relationship to the material and symbolic and processes of racialisation. The first part of the article identifies the limitations of research into the pro-school/anti-school orientations of minority students, arguing that most accounts are based on theories of culture, acculturation, class and gender, and class and race that neglect an analysis of race and sex. I then argue that practices of racialisation and sexualisation actually sustain pro-school culture and Asian female group associations. While these formations are effective in securing Asian female educational success, they are also problematic because they limit the educational possibilities and employment opportunities of Asian young women in Australia.

Productivity growth in pre-1990 Mongolian agriculture: Spiralling disaster or emerging success?

The reasons for the spectacular collapse of so many centrally-planned economies are a source of ongoing debate. In this paper, we use detailed farm-level data to measure total factor productivity (TFP) changes in Mongolian grain and potato farming during the 14-year period immediately preceding the 1990 economic reforms. We measure TFP growth using stochastic frontier analysis (SFA) and data envelopment analysis (DEA) methods. Our results indicate quite poor overall performance, with an average annual TFP change of - 1.7% in grain and 0.8% in potatoes, over the 14-year period. However, the pattern of TFP growth changed substantially during this period, with TFP growth exceeding 7% per year in the latter half of this period. This suggests that the new policies of improved education, greater management autonomy, and improved incentives, which were introduced in final two planning periods in the 1980s, were beginning to have a significant influence upon the performance of Mongolian crop farming. Crown Copyright (C) 2002 Published by Elsevier Science B.V. All rights reserved.

Structure of CcmG/DsbE at 1.14 angstrom resolution: High-fidelity reducing activity in an indiscriminately oxidizing environment

CcmG is unlike other periplasmic thioredoxin (TRX)like proteins in that it has a specific reducing activity in an oxidizing environment and a high fidelity of interaction. These two unusual properties are required for its role in c-type cytochrome maturation. The crystal structure of CcmG reveals a modified TRX fold with an unusually acidic active site and a groove formed from two inserts in the fold. Deletion of one of the groove-forming inserts disrupts c-type cytochrome formation. Two unique structural features of CcmG-an acidic active site and an adjacent groove-appear to be necessary to convert an indiscriminately binding scaffold, the TRX fold, into a highly specific redox protein.