903 research outputs found
Appeal No. 0330: Bob Lane dba Bethel Oil & Gas v. J. Michael Biddison, Chief, Division of Oil and Gas
Chief\u27s Order 88-156
Chicken Embryonic-Stem Cells Are Permissive to Poxvirus Recombinant Vaccine Vectors.
The discovery of mammalian pluripotent embryonic stem cells (ESC) has revolutionised cell research and regenerative medicine. More recently discovered chicken ESC (cESC), though less intensively studied, are increasingly popular as vaccine substrates due to a dearth of avian cell lines. Information on the comparative performance of cESC with common vaccine viruses is limited. Using RNA-sequencing, we compared cESC transcriptional programmes elicited by stimulation with chicken type I interferon or infection with vaccine viruses routinely propagated in primary chicken embryo fibroblasts (CEF). We used poxviruses (fowlpox virus (FWPV) FP9, canarypox virus (CNPV), and modified vaccinia virus Ankara (MVA)) and a birnavirus (infectious bursal disease virus (IBDV) PBG98). Interferon-stimulated genes (ISGs) were induced in cESC to levels comparable to those in CEF and immortalised chicken fibroblast DF-1 cells. cESC are permissive (with distinct host transcriptional responses) to MVA, FP9, and CNPV but, surprisingly, not to PBG98. MVA, CNPV, and FP9 suppressed innate immune responses, while PBG98 induced a subset of ISGs. Dysregulation of signalling pathways (i.e., NFÎșB, TRAF) was observed, which might affect immune responses and viral replication. In conclusion, we show that cESC are an attractive alternative substrate to study and propagate poxvirus recombinant vaccine vectors
Organoïdes hypophysaires : des outils pour caractériser le développement, la plasticité et les pathologies hypophysaires ?
Lâhypophyse, glande maitresse de lâorganisme, occupe une place centrale dans le systĂšme endocrinien. ComposĂ©e dâun lobe antĂ©rieur (adĂ©nohypophyse) responsable de la synthĂšse dâhormones et dâun lobe postĂ©rieur (neurohypophyse) de structure nerveuse, elle reçoit des informations hormonales en provenance de lâhypothalamus, des organes pĂ©riphĂ©riques et de ses propres cellules lui permettant de rĂ©guler les grandes fonctions physiologiques telles que la croissance, le mĂ©tabolisme, la reproduction ou le stress. ConstituĂ©e de plusieurs types cellulaires, chacun dĂ©diĂ© Ă une fonction, lâadĂ©nohypophyse doit adapter ses sĂ©crĂ©tions hormonales en fonction de la demande physiologique ou des modifications de son microenvironnement liĂ©es Ă des causes physiologiques, contextuelles ou pathologiques. Pour cela, elle fait preuve dâune grande plasticitĂ© qui met en jeu des changements dans le nombre, voire lâidentitĂ©, des cellules sĂ©crĂ©trices. Des cellules souches/progĂ©nitrices prĂ©sentes dans lâhypophyse chez lâadulte pourraient ĂȘtre impliquĂ©es. Les mĂ©canismes sous-jacents Ă cette plasticitĂ© sont mal Ă©lucidĂ©s. Afin de mieux les comprendre, des systĂšmes dâĂ©tude in vitro, tels que les organoĂŻdes capables de mimer la structure architecturale et la fonction tissulaires, offrent une opportunitĂ© intĂ©ressante. Ils permettent Ă©galement dâapprĂ©hender les dysfonctionnements hypophysaires et dâenvisager des approches thĂ©rapeutiques chez lâHomme et lâanimal dâĂ©levage. En outre, leur utilisation permet de contribuer au principe des 3R pour les approches expĂ©rimentales : remplacer, rĂ©duire et raffiner. Si les modĂšles hypophysaires actuels sont en cours dâĂ©mergence chez lâhumain et les rongeurs, leur mise en place chez les espĂšces Ă intĂ©rĂȘt agronomique reprĂ©sente un enjeu important. Le but de cette revue est de faire un Ă©tat des lieux sur lâavancĂ©e des travaux visant Ă dĂ©velopper les modĂšles dâorganoĂŻdes hypophysaires en Ă©valuant leurs avantages et leurs inconvĂ©nients. Auparavant, des Ă©lĂ©ments concernant lâhistologie de lâhypophyse, son dĂ©veloppement lors de lâembryogĂ©nĂšse et ses capacitĂ©s dâadaptation Ă des variations de son environnement seront dĂ©crits
Potentiel des organoĂŻdes cĂ©rĂ©braux comme modĂšles dâĂ©tude des neuropathologies chez les animaux domestiques
Le cerveau est un organe complexe et tout modĂšle pour l'Ă©tudier dans ses aspects normaux et pathologiques devient un outil de choix en neurobiologie. La maĂźtrise et la diffusion de protocoles permettant le dĂ©veloppement d'organoĂŻdes cĂ©rĂ©braux ont ouvert la voie Ă de nouvelles Ă©tudes dans le domaine du dĂ©veloppement du cerveau, de la modĂ©lisation des maladies neurodĂ©gĂ©nĂ©ratives ou neurodĂ©veloppementales, de la comprĂ©hension des tumeurs ainsi que des maladies infectieuses qui affectent le cerveau. Alors que les Ă©tudes se sont focalisĂ©es principalement sur l'utilisation d'organoĂŻdes cĂ©rĂ©braux humains, il existe un intĂ©rĂȘt croissant pour des modĂšles similaires chez d'autres espĂšces. Cette revue prĂ©sente ce qui est actuellement dĂ©veloppĂ© dans ce domaine avec un accent particulier sur le potentiel des organoĂŻdes cĂ©rĂ©braux pour l'Ă©tude des maladies neuro-infectieuses des animaux domestiques, notamment du cheval. Pour cette espĂšce, les atteintes neurologiques liĂ©es aux encĂ©phalites virales sont parmi les plus dommageables pour la filiĂšre. La mise au point de modĂšles dâorganoĂŻdes animaux et Ă©quins en particulier, les plus prĂ©dictifs possibles permettra Ă la fois de diminuer les coĂ»ts de recherche particuliĂšrement Ă©levĂ©s pour les Ă©tudes sur les maladies du cerveau et surtout de contribuer efficacement aux 3R, enjeu agronomique et sociĂ©tal
The Oct4 homologue PouV and Nanog regulate pluripotency in chicken embryonic stem cells
International audienceEmbryonic stem cells ( ESC) have been isolated from pregastrulation mammalian embryos. The maintenance of their pluripotency and ability to self- renew has been shown to be governed by the transcription factors Oct4 ( Pou5f1) and Nanog. Oct4 appears to control cell- fate decisions of ESC in vitro and the choice between embryonic and trophectoderm cell fates in vivo. In nonmammalian vertebrates, the existence and functions of these factors are still under debate, although the identification of the zebrafish pou2 ( spg; pou5f1) and Xenopus Pou91 ( XlPou91) genes, which have important roles in maintaining uncommitted putative stem cell populations during early development, has suggested that these factors have common functions in all vertebrates. Using chicken ESC ( cESC), which display similar properties of pluripotency and long- term self- renewal to mammalian ESC, we demonstrated the existence of an avian homologue of Oct4 that we call chicken PouV ( cPouV). We established that cPouV and the chicken Nanog gene are required for the maintenance of pluripotency and self- renewal of cESC. These findings show that the mechanisms by which Oct4 and Nanog regulate pluripotency and self- renewal are not exclusive to mammal
Geology and rural landscapes in central Spain (Guadalajara, CastillaâLa Mancha)
Methods commonly used in regional geological analysis were employed to study the visual landscapes of the SigĂŒenzaâMolina de AragĂłn area (Spain). Landscape data were compiled to produce a landscape map and a photograph
catalogue. Lithological composition, tectonic structure and recent erosive processes are the main factors controlling the visual landscapes. Territorial properties, such as colours and agricultural capacities, are controlled by these geological characteristics. The landscape map and the photographic catalogue is the main
contribution of this paper. The first level of landscape classification distinguishes zones with dominance of either flat, concave or convex areas. Other parts of the territory are, however, composed of concave and convex combinations that originate hybrid orographic structures. In a second level of classification, several subdivisions for each of these types are established
Search for composite and exotic fermions at LEP 2
A search for unstable heavy fermions with the DELPHI detector at LEP is
reported. Sequential and non-canonical leptons, as well as excited leptons and
quarks, are considered. The data analysed correspond to an integrated
luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV
and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172
GeV and 161 GeV. The search for pair-produced new leptons establishes 95%
confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2,
depending on the channel. The search for singly produced excited leptons and
quarks establishes upper limits on the ratio of the coupling of the excited
fermio
Search for charginos in e+e- interactions at sqrt(s) = 189 GeV
An update of the searches for charginos and gravitinos is presented, based on
a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector
in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was
found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a
centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by
combining the chargino searches with neutralino searches at the Z resonance
implies a limit on the mass of the lightest neutralino which, for a heavy
sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure
Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP
Promptly decaying lightest neutralinos and long-lived staus are searched for
in the context of light gravitino scenarios. It is assumed that the stau is the
next to lightest supersymmetric particle (NLSP) and that the lightest
neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector
at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of
the production of these particles is found. Hence, lower mass limits for both
kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is
found to be greater than 71.5 GeV/c^2. In the search for long-lived stau,
masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10
to 150 \eVcc . Combining this search with the searches for stable heavy leptons
and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc
may be set for the stau mas
Hadronization properties of b quarks compared to light quarks in e+e- -> q qbar from 183 to 200 GeV
The DELPHI detector at LEP has collected 54 pb^{-1} of data at a
centre-of-mass energy around 183 GeV during 1997, 158 pb^{-1} around 189 GeV
during 1998, and 187 pb^{-1} between 192 and 200 GeV during 1999. These data
were used to measure the average charged particle multiplicity in e+e- -> b
bbar events, _{bb}, and the difference delta_{bl} between _{bb} and the
multiplicity, _{ll}, in generic light quark (u,d,s) events: delta_{bl}(183
GeV) = 4.55 +/- 1.31 (stat) +/- 0.73 (syst) delta_{bl}(189 GeV) = 4.43 +/- 0.85
(stat) +/- 0.61 (syst) delta_{bl}(200 GeV) = 3.39 +/- 0.89 (stat) +/- 1.01
(syst). This result is consistent with QCD predictions, while it is
inconsistent with calculations assuming that the multiplicity accompanying the
decay of a heavy quark is independent of the mass of the quark itself.Comment: 13 pages, 2 figure
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