Hormonal induction of spermiation, courting behavior and spawning in the southern bell frog, Litoria raniformis

We trialled the efficacy of various exogenous hormones to induce spermiation, courtship behavior, and spawning in the "endangered" southern bell frog, Litoria raniformis. Intralymphatic administration of Lucrin®, a synthetic nonapeptide luteinizing hormone releasing hormone (LHRH), was used successfully to induce courting behaviors and ejaculation of spermatozoa in males. Various hormones, including Lucrin®, another synthetic LHRH analog ([des-Gly10, D-Ala6]-LHRH), human chorionic gonadotropin, progesterone, and a dopamine receptor antagonist failed to promote oviposition and spawning in females. This and earlier studies indicate that in the efficacy of hormonal induction in amphibians varies between taxa, hormones, and genders. The lack of response in females may limit the use of reproduction technology in the southern bell frog and closely related species of Australian bell frogs. © 2010 Wiley-Liss, Inc

Developmental toxicity of two common corn pesticides to the endangered southern bell frog (Litoria raniformis)

To examine the link between corn agriculture and the observed decline of the endangered southern bell frog (SBF), the effects of two corn crop pesticides on larval growth and development were investigated. Tadpoles were exposed to terbufos sulfone (10 μg/L), a major breakdown product of the insecticide terbufos, and the herbicide atrazine (25 μg/L) individually and as a mixture until the completion of metamorphosis. Atrazine did not interact synergistically with terbufos sulfone or result in significant effects on growth and development alone, although there was some indication of accelerated metamorphosis in the pilot study. Terbufos sulfone alone and as a mixture (terbufos/atrazine) significantly slowed larval development and ultimately delayed metamorphosis. The observed developmental effects from an environmentally relevant concentration of terbufos sulfone indicates a risk posed by this persistent degradation product to the endangered SBF, which breeds and develops in the rice bays adjacent to corn fields treated with pesticides. © 2010 Published by Elsevier Ltd

The alteration of the performance of field-aged Pd-based TWCs towards CO and C3H6 oxidation

The deactivation of a three-way catalyst (TWC) included in warm-up catalytic converters (WCC) employed in passenger vehicles has been examined with respect to the catalyst field mileage by drivers. By a sweep test (ST) under the A/F oscillation of 1 Hz simulating the actual operation of a gasoline engine, the gradual deactivation of CO oxidation activity under rich condition over the Pd TWCs customer-aged was clearly observed with respect to the catalyst mileage, while the oxidation activity of C3H6 had been hardly altered. No proportional dependence of the deactivation of the CO and C3H6 oxidation activity on the catalyst mileage, however, was determined by both a steady-state sweep test (st-ST) and a light-off test (LOT) without A/F perturbation, although the initial deactivation of both reactions by both test modes was apparent. The sintering of noble metal (NM) itself might not be the only cause for the deactivation of TWC with respect to the catalyst aging mileage. The gradual alteration of the oxygen storage capacity (OSC) of TWC. mainly due to the degradation of the oxygen storage components and the weakness of the Pd-Ce interaction, is also the cause for TWC deactivation, particularly for the CO oxidation reaction under rich condition. No deactivation of the oxidation reaction of C3H6 by ST, regardless of the catalyst mileages is likely due to the strong oxidative capability of I'd toward hydrocarbons. (C) 2009 Elsevier B.V. All rights reserved.X115051sciescopu