41,301 research outputs found
Effects of Probiotics on Zebrafish Reproduction
No full textRecent studies have demonstrated that probiotics can infuence reproductive performance, however, the mechanisms infuencing oogenesis remain poorly explored. In this study, the effects of dietary probiotic Lactobacillus rhamnosus IMC 501® administration was investigated on female zebrafish (D. rerio) reproductive performance and ovarian development (both growth and maturation phases). After feeding the zebrafish experimental diets for 10 days, real-time PCR and culture based methods revealed alterations on gut microbiota, characterised by high levels of L. rhamnosus IMC 501® in the gut of probiotic treated zebrafish, which were absent in the control. The microbial modulation in the gut was related with a signifcant increase of the gonadosomatic-index (GSI) associated, at the molecular level, to a signifcant increase of ovarian expression of cytochrome p 19 (cyp19a), hepatic vitellogenin (vtg) and the α isoform of the estradiol receptor (erα) genes evidencing a positive role of probiotic administration on the ovarian growth phase. Concomitantly, a signifcant increase of signals which positively control the maturation phase such as, cyclin B, activinβA1 and small mother against decapentaplegic 2 (smad2) genes in the ovary led us to confirm the beneficial role of the probiotic on maturation processes. Next to the enhancement of oocyte development processes by probiotic administration, an improvement of fecundity was evidenced which was associated with the increase of cyclooxygenase 2a (co×2a) gene expression in the ovary. The significance of the results obtained herein underlines the importance of diet and gut microbes in the reproductive processes, supporting the hypothesis that feed additives could improve fecundit
An alternative mechanism of clathrin-coated pit closure revealed by ion conductance microscopy
No full textCurrent knowledge of the structural changes taking place during clathrin-mediated endocytosis is largely based on electron microscopy images of fixed preparations and x-ray crystallography data of purified proteins. In this paper, we describe a study of clathrin-coated pit dynamics in living cells using ion conductance microscopy to directly image the changes in pit shape, combined with simultaneous confocal microscopy to follow molecule-specific fluorescence. We find that 70% of pits closed with the formation of a protrusion that grew on one side of the pit, covered the entire pit, and then disappeared together with pit-associated clathrin-enhanced green fluorescent protein (EGFP) and actin-binding protein-EGFP (Abp1-EGFP) fluorescence. This was in contrast to conventionally closing pits that closed and cleaved from flat membrane sheets and lacked accompanying Abp1-EGFP fluorescence. Scission of both types of pits was found to be dynamin-2 dependent. This technique now enables direct spatial and temporal correlation between functional molecule-specific fluorescence and structural information to follow key biological processes at cell surfaces
Effect of dietary alginic acid on juvenile tilapia (Oreochromis niloticus) intestinal microbial balance, intestinal histology and growth performance.
No full text1,3 proton transfer catalysts supported by Merrifield resin or Jeffamine gel
No full text6-Chloronicotinic acid was coupled by an amide linkage to Merrifield resin or Jeffamine gel. Nucleophilic displacement of the 6-chloride group by hydroxide gave novel Merrifield resin catalyst 6 or Jeffamine gel catalyst 9 that were successfully used for Henry condensations. The condensation of 4,6-O-benzylidene-β-D-glucopyranose 11 with nitromethane gave 4,6-O-benzylidene-D-glucopyranosyl-l-nitromethane 12; the condensation of 11 with nitroethane gave α-R-(4,6-O-benzylidene-β-D-glucopyranosyl)-1-nitroethane 13 and its diastereomer 15; the condensation of 11 with nitropropane, followed by acetylation, gave α-R-(2,3-di-O-acetyl-4,6-O-benzylidene-β- D-glucopyranosyl)-1 -nitropropane 16 and its diastereomer 17; the condensation of 4,6- O-isopropylidene-β-D-glucopyranose 19 with nitromethane gave 4,6-O-isopropylidene- β-D-glucopyranosyl-1-nitromethane 20; the condensation of 4,6-O-isopropylidene-α- D-mannopyranose 21 with nitromethane gave 4,6-O-isopropylidene-β-D-mannopyranosyl- 1-nitromethane 23. These known compounds were obtained with improved yields compared to protocols with 1,3 proton transfer catalysts that were not bound to polymers. A new monomeric 1,3 proton transfer catalyst, 2,4 (1,3)-quinazolinedione 10, was also introduced
Measurement of the branching fractions for B--> D(*)+pi(-)l(-)(nu)over-bar(l) and (B)over-bar(0)-> D-(*)0 pi(+)l(-)(nu)over-bar(l)
No full textWe report on a measurement of the branching fractions for B- --> D(*)+ pi(-)l(-)(nu) over bar (l) and (B) over bar (0) --> D-(*)0 pi(+)l(-)(nu) over bar (l) with 275 x 10(6) B (B) over bar events collected at the Y(4S) resonance with the Belle detector at KEKB. Events are tagged by fully reconstructing one of the B mesons in hadronic modes. We obtain B(B- --> D(+)pi(-)l(-)(nu) over bar (l)) = (0.54 +/- 0.07 (stat) +/- 0.07(syst) +/- 0.06(BR)) x 10(-2), B(B- --> D*+pi(-) l(-) (nu) over bar (l)) (0.67 +/- 0.11 (stat) +/- 0.09(syst) +/- 0.03(BR)) x 10(-2), B((B) over bar (0) --> D(0)pi(+)l(-) (nu) over bar (l)) = (0.33 +/- 0.06(stat) +/- 0.06(syst) +/- 0.03(BR)) x 10(-2), B((B) over bar (0) -->D(*0)pi(+)l(-)(nu) over bar (l)) = (0.65 +/- 0.12(stat) +/- 0.08(syst) +/- 0.05(BR)) x 10(-2), where the third error comes from the error on (B) over bar --> D((*))l(-)(nu) over bar (l) decays. Contributions from B-0 --> D(*+)l(-)(nu) over bar (l) decays are excluded in the measurement of (B) over bar (0) --> D(0)pi(+)l-(nu) over bar (l).Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)0ARTICLE5null7
Dietary modulation of immune response and related gene expression profiles in mirror carp (Cyprinus carpio) using selected exotic feed ingredients
No full textMicrobial manipulations to improve fish health and production--a Mediterranean perspective.
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
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