Local interneurons in the Drosophila antennal lobe are thought to play important roles in shaping odor responses. However, the physiological properties of excitatory local interneurons (eLNs) and their connectivity in the antennal lobe remain unclear. We first characterized the firing patterns of krasavietz-Gal4-labeled eLNs (krasavietz eLNs) in response to depolarizing currents. Paired recordings of krasavietz eLNs and PNs showed reciprocal excitatory connections mediated by dendrodendritic cholinergic synapses and gap junctions. Reciprocal connections were also found between two krasavietz eLNs but were rare between krasavietz eLNs and inhibitory LNs. Analysis of response onset latencies showed that krasavietz eLNs received monosynaptic inputs from ORNs. Furthermore, each eLN responded with distinct patterns to different odors, and each odor elicited distinct responses in different eLNs, with specific temporal patterns of spiking, indicating that eLNs serve specific coding functions in addition to global excitation in Drosophila olfactory processing.

No abstract

Feedback plays important roles in sensory processing. Mushroom bodies are believed to be involved in olfactory learning/memory and multisensory integration in insects. Previous cobalt-labeling studies have suggested the existence of feedback from the mushroom bodies to the antennal lobes in the honey bee. In this study, the existence of functional feedback from Drosophila mushroom bodies to the antennal lobes was investigated through ectopic expression of the ATP receptor P2X 2 in the Kenyon cells of mushroom bodies. Activation of Kenyon cells induced depolarization in projection neurons and local interneurons in the antennal lobes in a nicotinic receptor-dependent manner. Activation of Kenyon cell axons in the βγ-lobes in the mushroom body induced more potent responses in the antennal lobe neurons than activation of Kenyon cell somata. Our results indicate that functional feedback from Kenyon cells to projection neurons and local interneurons is present in Drosophila and is likely mediated by the βγ-lobes. The presence of this functional feedback from the mushroom bodies to the antennal lobes suggests top-down modulation of olfactory information processing in Drosophila.

A molecular phylogeny of Asiatic species of Goodyera (Orchidaceae, Cranichideae, Goodyerinae) based on the nuclear ribosomal internal transcribed spacer (ITS) region and two chloroplast loci (matK and trnL-F) was presented. Thirty-five species represented by 132 samples of Goodyera were analyzed, along with other 27 genera/48 species, using Pterostylis longifolia and Chloraea gaudichaudii as outgroups. Bayesian inference, maximum parsimony and maximum likelihood methods were used to reveal the intrageneric relationships of Goodyera and its intergeneric relationships to related genera. The results indicate that: 1) Goodyera is not monophyletic; 2) Goodyera could be divided into four sections, viz., Goodyera, Otosepalum, Reticulum and a new section; 3) sect. Reticulum can be further divided into two subsections, viz., Reticulum and Foliosum, whereas sect. Goodyera can in turn be divided into subsections Goodyera and a new subsection.

By using the recently developed Thomson scattering diagnostic, the pedestal structure of the H-mode with neutral beam injection (NBI) or/and lower hybrid wave (LHW) heating on EAST (Experimental Advanced Superconducting Tokamak) is analyzed in detail. We find that a higher ratio of the power of the NBI to the total power of the NBI and the lower hybrid wave (LHW) will produce a large and regular different edge-localized mode (ELM), and a lower ratio will produce a small and irregular ELM. The experiments show that the mean pedestal width has good correlation with β p , ped 0.5 , The pedestal width appears to be wider than that on other similar machines, which could be due to lithium coating. However, it is difficult to draw any conclusion of correlation between ρ * and the pedestal width for limited ρ * variation and scattered distribution. It is also found that T e/ ∇ T e is ~2 cm, which is the same as the AUG (ASDEX Upgrade), DIII-D and JET (Joint European Torus) results.

No abstract

Vegetative propagation (clonal growth) conveys several evolutionary advantages that positively affect life history fitness and is a widespread phenomenon among angiosperms that also reproduce sexually. However, a bias towards clonality can interfere with sexual reproduction and lead to sexual extinction, although a dearth of effective genetic tools and mathematical models for clonal plants has hampered assessment of these impacts. Using the endangered tropical epiphytic or lithophytic orchid Bulbophyllum bicolor as a model, we integrated an examination of breeding system with 12 microsatellite loci and models valid for clonal species to test for the "loss of sex" and infer likely consequences for long-term reproductive dynamics. Bagging experiments and field observations revealed B. bicolor to be self-incompatible and pollinator-dependent, with an absence of fruit-set over 4 years. Challenging the assumptions that clonal populations can be as genotypically diverse as sexually reproducing ones and that clonality does not greatly influence genetic structure, just 22 multilocus genotypes were confirmed among all 15 extant natural populations, 12 of the populations were found to be monoclonal, and all three multiclonal ones exhibited a distinct phalanx clonal architecture. Our results suggest that all B. bicolor populations depend overwhelmingly on clonal growth for persistence, with a concomitant loss of sex due to an absence of pollinators and a lack of mating opportunities at virtually all sites, both of which are further entrenched by habitat fragmentation. Such cryptic life history impacts, potentially contributing to extinction debt, could be widespread among similarly fragmented, outcrossing tropical epiphytes, demanding urgent conservation attention.

The synthesis and characterization of novel fluorine-containing PMR polyimides derived from the diethyl ester of 4,4′-(2,2,2-trifluoro-1-phenylethylidene)diphthalic acid, p-phenylenediamine, and the monoethyl ester of cis-5-norbornene-endo-2,3-dicarboxylic acid in low boiling solvents were described. The fluoropolyimide resin solutions are stable for several weeks at room temperatures and can easily impregnate carbon fibers to prepare prepregs. The molded resins exhibit outstanding thermal and thermooxidative stabilities at temperatures as high as 350 °C.