A reassessment of the genus Oligoneuriopsis Crass, 1947 (Ephemeroptera, Oligoneuriidae, Oligoneuriellini)

The distinction between the two closely related genera Oligoneuriella Ulmer, 1924 and Oligoneuriopsis Crass, 1947 has been much debated. First described from South Africa, Oligoneuriopsis seemed to be a clearly defined genus. However, as the known distribution of the genus widened and knowledge on it expanded, species delimitation based on morphology became less clear due to overlap in several apparently defining morphological characters, especially in the nymphs. This work attempts to reassess Oligoneuriopsis morphology in the context of all currently known species. The type species, Oligoneuriopsis lawrencei Crass, 1947 is redescribed at the imaginal and nymphal stages and a neotype is designated. The putative nymph of Oligoneuriopsis dobbsi (Eaton, 1912) is described based on material collected around Mt Elgon (Kenya). The adults of Oligoneuriella orontensis Koch, 1980 are described for the first time and the species is transferred to the genus Oligoneuriopsis (Oligoneuriopsis orontensiscomb. nov.). Egg structure is also described for the first time for the species Oligoneuriopsis skhounate and O. orontensis. Some biogeographical considerations are also given. It is likely that more species will still be discovered, especially in Africa

Cavity electromechanics with parametric mechanical driving

Microwave optomechanical circuits have been demonstrated to be powerful tools for both exploring fundamental physics of macroscopic mechanical oscillators, as well as being promising candidates for on-chip quantum-limited microwave devices. In most experiments so far, the mechanical oscillator is either used as a passive element and its displacement is detected using the superconducting cavity, or manipulated by intracavity fields. Here, we explore the possibility to directly and parametrically manipulate the mechanical nanobeam resonator of a cavity electromechanical system, which provides additional functionality to the toolbox of microwave optomechanics. In addition to using the cavity as an interferometer to detect parametrically modulated mechanical displacement and squeezed thermomechanical motion, we demonstrate that this approach can realize a phase-sensitive parametric amplifier for intracavity microwave photons. Future perspectives of optomechanical systems with a parametrically driven mechanical oscillator include exotic bath engineering with negative effective photon temperatures, or systems with enhanced optomechanical nonlinearities

A chick model for the mechanisms of mustard gas neurobehavioral teratogenicity

The chemical warfare blistering agent, sulfur mustard (SM), is a powerful mutagen and carcinogen. Due to its similarity to the related chemotherapy agents nitrogen mustard (mechlorethamine), it is expected to act as a developmental neurotoxicant. The present study was designed to establish a chick model for the mechanisms of SM on neurobehavioral teratogenicity, free of confounds related to mammalian maternal effects. Chicken eggs were injected with SM at a dose range of 0.0017-17.0 mug/kg of egg, which is below the threshold for clysmorpholog, on incubation days (ID) 2 and 7, and then tests were conducted posthatching. Exposure to SM elicited significant deficits in the intermedial part of the hyperstriatum ventrale (IMHV)-related imprinting behavior. Parallel decreases were found in the level of membrane PKCgamma in the IMHV, while eliciting no net change in cytosolic PKCgamma. The chick, thus, provides a suitable model for the rapid evaluation of SM behavioral teratogenicity and elucidation of the mechanisms underlying behavioral anomalies. The results obtained, using a model that controls for confounding maternal effects, may be replicated in the mammalian model and provide the groundwork for studies designed to offset or reverse the SM-induced neurobehavioral defects in both avian and mammals. (C) 2004 Elsevier Inc. All tights reserved.</p