801 research outputs found

    Ecdysteroids and oocyte development in the black fly Simulium vittatum

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    BACKGROUND: Oocyte development was studied in the autogenous black fly, Simulium vittatum (Diptera, Nematocera), a vector of Onchocerca volvulus, the causative agent of onchocerciasis. RESULTS: Oocyte growth was nearly linear between adult eclosion and was complete by 72 hours at 21°C. The oocyte became opaque at 14 hours after eclosion indicating the initiation of protein yolk deposition. The accumulation of vitellogenin was measured using SDS-PAGE. The density of the yolk protein bands at about 200 and 65 kDa increased during the first and second days after eclosion. The amount of protein in the 200 kDa band of vitellogenin, determined using densitometry, rapidly increased between 12 and 25 hours after eclosion. Ecdysteroid levels were measured using a competitive ELISA. Ecdysteroid levels increased rapidly and subsequently declined during the first day after eclosion. CONCLUSION: These data show a correlation between the appearance of vitellogenin in the oocyte, and the rise in ecdysteroids. A possible relationship to molting of the nematode, Onchocerca volvulus, is discussed

    Neurologic effects of exogenous saccharides: A review of controlled human, animal, and in vitro studies

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    Objectives: Current research efforts are centered on delineating the novel health benefits of naturally derived saccharides, including growing interest in their abilities to influence neurologic health. We performed a comprehensive review of the literature to consolidate all controlled studies assessing various roles of exogenous saccharide compounds and polysaccharide-rich extracts from plants, fungi, and other natural sources on brain function, with a significant focus on benefits derived from oral intake. Methods: Studies were identified by conducting electronic searches on PubMed and Google Scholar. Reference lists of articles were also reviewed for additional relevant studies. Only articles published in English were included in this review. Results: Six randomized, double-blind, placebo-controlled clinical studies were identified in which consumption of a blend of plant-derived polysaccharides showed positive effects on cognitive function and mood in healthy adults. A separate controlled clinical study observed improvements in well-being with ingestion of a yeast beta-glucan. Numerous animal and in vitro studies have demonstrated the ability of individual saccharide compounds and polysaccharide-rich extracts to modify behavior, enhance synaptic plasticity, and provide neuroprotective effects. Discussion: Although the mechanisms by which exogenous saccharides can influence brain function are not well understood at this time, the literature suggests that certain naturally occurring compounds and polysaccharide-rich extracts show promise, when taken orally, in supporting neurologic health and function. Additional well-controlled clinical studies on larger populations are necessary, however, before specific recommendations can be made

    Kaon decay interferometry as meson dynamics probes

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    We discuss the time dependent interferences between KLK_L and KSK_S in the decays in 3π3\pi and ππγ\pi\pi\gamma, to be studied at interferometry machines such as the ϕ\phi-factory and LEAR. We emphasize the possibilities and the advantages of using interferences, in comparison with width measurements, to obtain information both on CPCP conserving and CPCP violating amplitudes. Comparison with present data and suggestions for future experiments are made.Comment: 15 pages, in RevTex, Report INFNNA-IV-93-31, UTS-DFT-93-2

    Final State Interactions and CP Violation in KLπ+πe+eK_L \to \pi^+ \pi^- e^+ e^-

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    Using chiral perturbation theory we calculate the imaginary parts of the KLπ+πe+eK_L \rightarrow \pi^+ \pi^- e^+ e^- form factors that arise from πππ+π\pi \pi \rightarrow \pi^+ \pi^- and πππ+πγ\pi \pi \rightarrow \pi^+ \pi^- \gamma^* rescattering. We discuss their influence on CP violating variables in KLπ+πe+eK_L \rightarrow \pi^+ \pi^- e^+ e^-.Comment: ; 12 pages, 2 figures, TeX format; uses epsf.tex, tables.tex, and phyzzx.te
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