62,734 research outputs found
Mutations in the Aeromonas salmonicida subsp. salmonicida type III secretion system affect Atlantic salmon leucocyte activation and downstream immune responses
No full textDeletion mutants of Aeromonas salmonicida subsp. salmonicida were used to determine the effect of the type three secretion system (TTSS) on Atlantic salmon anterior head kidney leucocytes (AHKL). One strain had a deletion in the outer membrane pore gene, ascC; and the other in three effector genes: aopO, aopH and aexT (we call this strain Δaop3). Host cell invasion success and 24h survival were depressed in ΔascC, as was 24h survival of Δaop3, when compared to the wild type strain. Challenge of AHKLs with A449 or TTSS mutants stimulated expression of the inflammatory mediators IL-8, IL-1 and TNFα at two bacterial concentrations (A600 0.1, 0.01). Expression of IL-12 was not stimulated in ΔascC challenged cells, whereas A449 and Δaop3 challenge resulted in an up-regulation of IL-12 in AHKLs, 2- and 4-fold higher than PBS, respectively. Only the wild type strain elicited a significant increase in IL-10 expression (5.5× at A600 0.1). Inducible nitric oxide synthetase (iNOS) and arginase (I+II) genes were also significantly up-regulated upon exposure to all strains. However, iNOS:arginase ratio was elevated in the effector mutant challenge. These results suggest that A. salmonicida subsp. salmonicida may enhance survival within the host cell through polarization of macrophages/leucocytes to an alternative, rather than classical, activation state. Furthermore, the short-term survival and lack of T-cell signalling cytokine stimulation in ΔascC, may help explain its inefficiency at providing protection to subsequent wild type challenge.ID: S1050464809002988; M3: Article; Accession Number: S1050464809002988; Author: Mark D. Fast (a, ∗); Author: Brenda Tse (b); Author: Jessica M. Boyd (c); Author: Stewart C. Johnson (d); Affiliation: School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York 11794-5000, USA; Affiliation: Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada; Affiliation: Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada; Affiliation: Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada; Keyword: Aeromonas salmonicida; Keyword: Type three secretion system; Keyword: Atlantic salmon; Keyword: SHK-1; Keyword: Gene expression; Keyword: Inflammation; Keyword: Activation; Keyword: Interleukin-1β; Keyword: (IL-1β); Keyword: Interleukin-10; Keyword: Interleukin-12; Number of Pages: 8; Language: English;Source type: Electronic(1
Effects of Moritella viscosa antigens on pro-inflammatory gene expression in an Atlantic salmon (Salmo salar Linnaeus) cell line (SHK-1)
No full textMoritella viscosa is the causative agent of winter ulcer disease in salmonids reared in North-Atlantic countries. In this study the effects of selected M. viscosa antigens on cytotoxicity and pro-inflammatory gene expression in an Atlantic salmon (Salmo salar Linnaeus) macrophage-like cell line (SHK-1) were examined. SHK-1 cells were stimulated with live and heat-killed bacterial cells, extracellular products (ECP) and an extracellular vibriolysin, termed MvP1. Following incubation, cytotoxicity and expression levels of interleukin-1β (IL-1β) and interleukin-8 (IL-8) were examined at different time points. Both live M. viscosa cells and ECP were cytotoxic, but neither heat-killed cells, nor the MvP1 peptidase caused cell death. Expression levels of both IL-1β and IL-8 increased significantly after stimulation with live cells, but heat-killed cells only caused increased IL-8 expression. ECP did not affect IL-1β expression, but did stimulate IL-8 expression. The isolated MvP1 peptidase stimulated both IL-1β and IL-8 expression at the highest concentration tested. This study reveals a difference in the induction of pro-inflammatory gene expression in salmon SHK-1 cells between live and heat-killed M. viscosa cells, and also that an unknown secreted factor is the main stimulant of IL-β and IL-8 expression.ID: S1050464809000990; M3: Article; Accession Number: S1050464809000990; Author: Bryndis Bjornsdottir (a, b); Author: Mark D. Fast (b, 1); Author: Sandra A. Sperker (b); Author: Laura L. Brown (b, 2); Author: Bjarnheidur K. Gudmundsdottir (a, ∗); Affiliation: Institute for Experimental Pathology, University of Iceland, Keldur v/Vesturlandsveg, 112 Reykjavík, Iceland; Affiliation: National Research Council Canada, Institute for Marine Biosciences, 1411 Oxford Street, Halifax, Nova Scotia B3H 2Z1, Canada; Keyword: Moritella viscosa; Keyword: Extracellular products; Keyword: MvP1 vibriolysin; Keyword: Atlantic salmon; Keyword: SHK-1; Keyword: Gene expression; Keyword: Immune response; Keyword: Pro-inflammatory cytokine; Keyword: Interleukin-1β (IL-1β); Keyword: Interleukin-8 (IL-8); Number of Pages: 6; Language: English;Source type: Electronic(1
1ST MEASUREMENT OF GAMMA(D(S)(+)-]MU+NU)/GAMMA(D(S)(+)-]PHI-PI+)
No full textComplete Author List:
ACOSTA D, ATHANAS M, MASEK G, PAAR H, BEAN A, GRONBERG J, KUTSCHKE R, MENARY S, MORRISON RJ, NAKANISHI S, NELSON HN, NELSON TK, RICHMAN JD, RYD A, TAJIMA H, SCHMIDT D, SPERKA D, WITHERELL MS, PROCARIO M, YANG S, BALEST R, CHO K, DAOUDI M, FORD WT, JOHNSON DR, LINGEL K, LOHNER M, RANKIN P, SMITH JG, ALEXANDER JP, BEBEK C, BERKELMAN K, BESSON D, BROWDER TE, CASSEL DG, CHO HA, COFFMAN DM, DRELL PS, EHRLICH R, GALIK RS, GARCIASCIVERES M, GEISER B, GITTELMAN B, GRAY SW, HARTILL DL, HELTSLEY BK, JONES CD, JONES SL, KANDASWAMY J, KATAYAMA N, KIM PC, KREINICK DL, LUDWIG GS, MASUI J, MEVISSEN J, MISTRY NB, NG CR, NORDBERG E, OGG M, PATTERSON JR, PETERSON D, RILEY D, SALMAN S, SAPPER M, WORDEN H, WURTHWEIN F, AVERY P, FREYBERGER A, RODRIGUEZ J, STEPHENS R, YELTON J, CINABRO D, HENDERSON S, KINOSHITA K, LIU T, SAULNIER M, SHEN F, WILSON R, YAMAMOTO H, ONG B, SELEN M, SADOFF AJ, AMMAR R, BALL S, BARINGER P, COPPAGE D, COPTY N, DAVIS R, HANCOCK N, KELLY M, KWAK N, LAM H, KUBOTA Y, LATTERY M, NELSON JK, PATTON S, PERTICONE D, POLING R, SAVINOV V, SCHRENK S, WANG R, ALAM MS, KIM IJ, NEMATI B, ONEILL JJ, SEVERINI H, SUN CR, ZOELLER MM, CRAWFORD G, DAUBENMIER CM, FULTON R, FUJINO D, GAN KK, HONSCHEID K, KAGAN H, KASS R, LEE J, MALCHOW R, MORROW F, SKOVPEN Y, SUNG M, WHITE C, WHITMORE J, WILSON P, BUTLER F, FU X, KALBFLEISCH G, LAMBRECHT M, ROSS WR, SKUBIC P, SNOW J, WANG PL, WOOD M, BORTOLETTO D, BROWN DN, FAST J, MCILWAIN RL, MIAO T, MILLER DH, MODESITT M, SCHAFFNER SF, SHIBATA EI, SHIPSEY IPJ, WANG PN, BATTLE M, ERNST J, KROHA H, ROBERTS S, SPARKS K, THORNDIKE EH, WANG CH, DOMINICK J, SANGHERA S, SHELKOV V, SKWARNICKI T, STROYNOWSKI R, VOLOBOUEV I, ZADOROZHNY P, ARTUSO M, HE D, GOLDBERG M, HORWITZ N, KENNETT R, MONETI GC, MUHEIM F, MUKHIN Y, PLAYFER S, ROZEN Y, STONE S, THULASIDAS M, VASSEUR G, ZHU G, BARTELT J, CSORNA SE, EGYED Z, JAIN V, SHELDON P, AKERIB DS, BARISH B, CHADHA M, CHAN S, COWEN DF, EIGEN G, MILLER JS, OGRADY C, URHEIM J, WEINSTEIN A
Automatic Parametric Hull Form Optimization of Fast Naval Vessels
No full textIn the present paper the final outcomes of a research project between the Department of Naval Architecture and Marine Engineering of the University of Genoa and Cetena S.p.A. for the Italian Navy in the frame of National Defence Research Plan are presented.
A study about the automatic optimization of the fore hull forms of a fast frigate has been carried out. On the basis of a technical specification provided by the Italian Navy, the initial shape of the hull has been defined by means of an accurate preliminary design leading to a set of geometrical constraints for the optimization process.
The fully automatic optimization chain has been implemented adopting the ModeFrontier optimization environment to interface the Friendship-Framework (parametric definition of the hull shape), the CFD codes developed by CETENA S.p.A. (to predict the steady -wave resistance- and unsteady –seakeeping- performances of each design candidate), and a MOGA genetic algorithm.
Numerical results have been validated by means of calm water model tests performed at the Towing Tank of the Department of Naval Architecture and Electrical Engineering (DINAEL) of the University of Genoa.
Notwithstanding the rather high number of constraints, which limit geometry variations, it was possible to obtain an optimal solution, and results have been confirmed by the experimental tests
Fusion product studies via fast ion D-D and D-3He fusion on JET
No full textDedicated fast ion D-D and D-3He fusion experiments were performed on JET with carbon wall (2008) and ITER-like wall (2014) for testing the upgraded neutron and energetic ion diagnostics of fusion products. Energy spectrum of D-D neutrons was the focus of the studies in pure deuterium plasmas. A significant broadening of the energy spectrum of neutrons born in D-D fast fusion was observed, and dependence of the maximum D and D-D neutron energies on plasma density was established. Diagnostics of charged products of aneutronic D-3He fusion reactions, 3.7 MeV alpha-particles similar to those in D-T fusion, and 14.6 MeV protons, were the focus of the studies in D-3He plasmas. Measurements of 16.4 MeV gamma-rays born in the weak secondary branch of D(3He, γ)5Li reaction were used for assessing D-3He fusion power. For achieving high yield of D-D and D-3He reactions at relatively low levels of input heating power, an acceleration of D beam up to the MeV energy range was used employing 3rd harmonic () ICRH technique. These results were compared to the techniques of D beam injection into D-3He mixture, and 3He-minority ICRH in D plasmas
Electrophysiological Heterogeneity of Fast-Spiking Interneurons: Chandelier versus Basket Cells
No full textIn the prefrontal cortex, parvalbumin-positive inhibitory neurons play a prominent role in the neural circuitry that subserves working memory, and alterations in these neurons contribute to the pathophysiology of schizophrenia. Two morphologically distinct classes of parvalbumin neurons that target the perisomatic region of pyramidal neurons, chandelier cells (ChCs) and basket cells (BCs), are generally thought to have the same "fast-spiking" phenotype, which is characterized by a short action potential and high frequency firing without adaptation. However, findings from studies in different species suggest that certain electrophysiological membrane properties might differ between these two cell classes. In this study, we assessed the physiological heterogeneity of fast-spiking interneurons as a function of two factors: species (macaque monkey vs. rat) and morphology (chandelier vs. basket). We showed previously that electrophysiological membrane properties of BCs differ between these two species. Here, for the first time, we report differences in ChCs membrane properties between monkey and rat. We also found that a number of membrane properties differentiate ChCs from BCs. Some of these differences were species-independent (e.g., fast and medium afterhyperpolarization, firing frequency, and depolarizing sag), whereas the differences in the first spike latency between ChCs and BCs were species-specific. Our findings indicate that different combinations of electrophysiological membrane properties distinguish ChCs from BCs in rodents and primates. Such electrophysiological differences between ChCs and BCs likely contribute to their distinctive roles in cortical circuitry in each species. © 2013 Povysheva et al
Fast-sampling fast-ion D-alpha measurement using multi-anode photomultiplier tube in large helical device
No full textORCID 0000-0002-5222-6082A fast-sampling fast-ion D-alpha (F-FIDA) measurement has been developed in the large helical device in order to investigate fast ion dynamics associated with helically trapped fast-ion-driven Magnetohydrodynamic (MHD) bursts. F-FIDA consists of a multi-anode photomultiplier tube (PMT) and achieves a sampling rate of 10 kHz. During the deuterium experiment campaign in 2022, F-FIDA measured the spectrum of perpendicular fast ions, using perpendicular lines of sight. We compared F-FIDA with conventional FIDA, using an electron multiplying charge coupled device, and confirmed that the time-averaged images were generally consistent between the two. The statistical properties of the temporal evolution associated with MHD bursts were analyzed using a conditional sampling technique. The results showed that the PMT signal varied in different spatial and wavelength channels. Although the signal-to-noise ratio was poor and there was room for improvement, it could provide useful information for studies on the phase-space dynamics of fast ions.journal articl
Fast track children's hearing pilot : final report of the evaluation of the pilot
No full textThis report presents key findings of the evaluation of the Fast Track children’s hearings pilot in Scotland. The research was undertaken by staff at the Universities of Glasgow, Stirling and Strathclyde between February 2003 and January 2005
Conceptual Design of the FAST-D Formation Flying Spacecraft
No full textThe paper presents the latest results in the design of FAST-D, the Dutch micro-satellite for the Dutch–Chinese FAST (Formation for Atmospheric Science and Technology demonstration) formation flying mission. Over the course of the 2.5 year mission, the two satellites, FAST-D and FAST-T, will demonstrate various new technologies and perform observations of atmospheric aerosols and seasonal variations of height profiles in the cryosphere using spectropolarimeter and altimeter payloads on both spacecraft. A conceptual design for the Dutch spacecraft, FAST-D, is presented. Special focus is laid on the design of the attitude determination and control subsystem and on the space-based computing experiments to be performed on this spacecraft. Furthermore, new results in the development of the science payloads on FAST-D, the aerosol characterisation instrument SPEX (Spectropolarimeter for Planetary Exploration) and the altimeter SILAT (Stereo Imaging Laser Altimeter), are described. For SPEX, several design changes have been made to make the instrument more compatible with the FAST mission. For SILAT, an instrument re-design for Earth missions is presented, which results in considerable mass savings as compared to the earlier design.Space EngineeringAerospace Engineerin
Cortisol response and immune-related effects of Atlantic salmon (Salmo salar Linnaeus) subjected to short- and long-term stress
No full textIt is generally considered that stress causes decreased immune function in fish. In this study we examined in Atlantic salmon (Salmo salar Linnaeus) the effects of both short- (a single 15 s out of water) and long-term (4 weeks of daily handling 15 s out of water) stress on plasma cortisol (free and total) and glucose levels, expression of interleukin-1\u3b2 (IL-1\u3b2) and survival of head kidney (HK) macrophages under culture with Aeromonas salmonicida. In the short-term study, samples were collected prior to the application of the stressor, and at 1, 3, 6, 12 and 24 h post stress. Free and total plasma cortisol levels and the percentage of free cortisol increased significantly in the stressed group at 1 and 3 h post stress. Plasma glucose levels were significantly higher than those of control fish at 1, 3 and 6 h post stress. Constitutive expression of IL-1\u3b2 in macrophages isolated from head kidneys in stressed fish was significantly higher at 1 and 3 h post stress. However, lipopolysaccharide (LPS) stimulated expression of IL-1\u3b2 in HK macrophages, exhibited significantly higher fold increases in unstressed fish compared to stressed fish. In the long-term study, with the exception of an increase in plasma glucose levels at 1 week, there were no significant differences in stress parameters between groups. There was a significantly higher constitutive IL-1\u3b2 expression in macrophages isolated from stressed fish over the first 2 weeks. At weeks 1, 2 and 3 the magnitude of IL-1\u3b2 response of isolated HK macrophages to LPS stimulation was reduced in >90% of the stressed fish. At 4 weeks there was no significant difference in inducible IL-1\u3b2 expression between the groups. Macrophages isolated from stressed fish also showed significantly decreased survival when exposed to A. salmonicida. This study shows a clear pattern from repeated handling stress, whereby effects on immune cells begin with increased constitutive expression of IL-1\u3b2, followed by decreased stimulation of leucocytes by extracellular antigen, and finally decreased leukocyte survival when exposed to A. salmonicida. The implications of these changes in the immune system will be discussed with respect to the use of classical indicators of stress to predict possible effects on the immune system of fish.Peer reviewed: YesNRC publication: Ye
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