Estimation of main diversification time-points of hantaviruses using phylogenetic analyses of complete genomes

Because of the great variability of their reservoir hosts, hantaviruses are excellent models to evaluate the dynamics of virus-host co-evolution. Intriguing questions remain about the timescale of the diversification events that influenced this evolution. In this paper we attempted to estimate the first ever timing of hantavirus diversification based on thirty five available complete genomes representing five major groups of hantaviruses and the assumption of co-speciation of hantaviruses with their respective mammal hosts. Phylogenetic analyses were used to estimate the main diversification points during hantavirus evolution in mammals while host diversification was mostly estimated from independent calibrators taken from fossil records. Our results support an earlier developed hypothesis of co-speciation of known hantaviruses with their respective mammal hosts and hence a common ancestor for all hantaviruses carried by placental mammals. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

Vectors for therapeutic antisense sequences delivery and the modification of messenger RNA processing

Synthetic antisense oligoribonucleotides can be used to modulate gene splicing by masking key motifs on the pre-mRNA required for spliceosome assembly. Yet, intracellular expression of oligoribonucleotides generates only a transitory effect whereas stable delivery of antisense sequences can be achieved by linking them to chimeric small RNAs delivered and expressed by viral vectors. In the murine model of Duchenne Muscular Dystrophy a chimeric U7 snRNA (U7Dtex23) induces skipping of the mutated exon 23 and restores the Dystrophin mRNA reading frame. The main limitation of this approach remains the large amount of snRNA vector needed to be produced and administered to patients. To optimize this system we used self-complementary AAV vectors (scAAV) to express the U7snRNA shuttles. ScAAV vectors were tested in mouse myoblast cultures and we observed an increase in U7Dtex23 expression and in dystrophin exon 23 skipping compared to single-stranded AAV, highlighting the potential for this strategy to reduce the vector dose. Alternatively, we have used a muscle and heart-specific enhancer (MHCK) to drive the expression of U7Dtex23 cassettes delivered with AAV vectors and our results showed that MHCK improves chimeric U7snRNA expression and increases dystrophin exon 23 skipping in vitro and in vivo. However, additional U7snRNA species were produced following gene transfer, pointing at a possible limitation of the cellular processing machinery capability with saturating levels of U7 shuttles. We have also explored the possibility of using small nucleolar (sno) RNAs as novel molecular platforms for antisense delivery. We replaced the original antisense of MBII-52 snoRNA with the Dtex23 sequence and observed low levels of exon 23 skipping in AAV-transduced myotubes. While our observation validates the approach, the efficiency of skipping is still considerably lower than with the U7snRNA cassette. As a last approach, we engineered the human C/D box U24snoRNA to specifically target the methylation of an adenosine branch point in a luciferase reporter pre-mRNA in order to induce the skipping of the downstream exon. We were not able to observe any modulation of splicing using this strategy

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ESR study of the spin adducts of three analogues of DEPMPO substituted at C-4 or C-3

In the research program of some new derivatives of spin-trap DEPMPO (5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide) leading to various radical adducts with photogenic ESR signals, three phosphorylated pyrroline-N-oxides were studied in spin trapping. These nitrones were proved to trap a variety of free radicals to afford adducts presenting characteristic ESR signals enabling unambiguous identification of the radical species trapped. From the general patterns of the signals, the adduct geometries were determined. Two of the nitrones bore a hydroxylmethyl substituent (HM) on the pyrroline ring, either at C-3 or at C-4. The two diastereoisomers of nitrone 4-HMDEPMPO, whose synthesis has been already described, were separately studied. The isomer (4R*,5R*) of 4-HMDEPMPO afforded stereoselectively, with superoxide or peroxyl radicals, trans adducts versus the phosphoryl group, however, they formed two rotamer sets in chemical exchange. In comparison with DEPMPO adducts, the exchanges rates of the conformer sets of 4-HMcisDEPMPO-OOH and 4-HMcisDEPMPO-(OOBu)-Bu-t were 9-fold or 2-fold smaller respectively. The eight-line signals of theses adducts were easily recognisable. The trapping of the same radicals with the other diastereoisomer (4S*,5R*)-4-HMDEPMPO or with (3S*,5R*)-3-HMDEPMPO, obtained via oxidation of a phosphorylated pyrroline, led to more complicated spectra owing to the formation of diastereoisomer adducts. The signal of each diastereoisomer adduct was simulated with two species in conformational exchange. In comparison with DEPMPO, the cis-C-4-substitution was proved to slow by 26-fold the exchange rate between the two rotamer sets of the trans superoxide adduct versus the phosphoryl group. The trans-C-3-substitution was proved to slow by 18-fold, at 223 K, the exchange rate between the two rotamer sets of the trans terbutylperoxyl adduct. The last nitrone, a bicyclic one, named MEOOPPO (6a-methyl-(6-ethoxy-5-oxa-6-oxaphospholan-6-yl)-1-pyrroline-N-oxide) was obtained directly from (4R*,5R*)-4-HMDEPMPO in basic conditions. Superoxide with the rigid MEOOPPO reacts exclusively in trans addition versus the phosphoryl group, however, the adduct obtained in aqueous buffer was not very persistent and the nitrone was partially degraded during 30 min storage. For every nitrone, the hydroxyl radical was not added stereoselectively on one ring face and some diasteroisomer adducts were obtained

Metabolic stability of superoxide adducts derived from newly developed cyclic nitrone spin traps

Reactive oxygen species are by-products of aerobic metabolism involved in the onset and evolution of various pathological conditions. Among them, the superoxide radical is of special interest as the origin of several damaging species such as H2O2, hydroxyl radical, or peroxynitrite (ONOO-). Spin trapping coupled with ESR is a method of choice to characterize these species in chemical and biological systems and the metabolic stability of the spin adducts derived from reaction of superoxide and hydroxyl radicals with nitrones is the main limit to the in vivo application of the method. Recently, new cyclic nitrones bearing a triphenylphosphonium or permethylated β-cyclodextrin moiety have been synthesized and their spin adducts demonstrated increased stability in buffer. In this article, we studied the stability of the superoxide adducts of four new cyclic nitrones in the presence of liver subcellular fractions and biologically relevant reductants using an original setup combining a stopped-flow device and an ESR spectrometer. The kinetics of disappearance of the spin adducts were analyzed using an appropriate simulation program. Our results highlight the interest of the new spin trapping agents CD-DEPMPO and CD-DIPPMPO for specific detection of superoxide with high stability of the superoxide adducts in the presence of liver microsomes. © 2013 Elsevier Inc. All rights reserved

Subjectivation, intersubjectivité et travail du lien dans le jeu vidéo de rôle en ligne massivement multijoueur

Le jeu vidéo proposerait une nouvelle forme de subjectivation autour de l action en mouvement, dont le moteur apparait dans l organisation fantasmatique. L auto-empathie va s y déployer : processus par lequel un sujet se met à la place de l autrui-en-soi, produisant un regard intériorisé sur soi pour représenter son monde subjectif. La médiatisation de ce processus d auto-empathie dans les mondes virtuels va permettre au sujet de se mettre à la place d une figure qui le représente, de telle façon que son attention et son empathie pour cette figure sont tournées indirectement vers lui-même. Ce second temps d'empathie virtuelle pour une figure de soi, que nous appelons auto-empathie médiatisée par un avatar ou auto-empathie virtuelle, favoriserait dans un troisième temps le développement d une empathie pour soi. Enfin dans un quatrième temps, dans les jeux de rôle en ligne multi-joueurs, serait favorisé le développement d une nouvelle forme de travail du lien intersubjectif : différenciateur plutôt que sexuel, engageant l action dans des proto-conversations plutôt que les émotions entre joueurs, et ressortant du domaine fantasmatique, l autre joueur étant toujours représenté par le sujet avant d être perçu, sollicitant entre les joueurs un désir d intersubjectivité par lequel il faut entendre le désir d une rencontre dans le monde réel d un autre joueur par la mise en jeu d un fantasme dans lequel les représentations imaginaires sont tournées vers la figuration, imaginaire également, d un sujet réel derrière un autre avatarVideo games propose a new form of subjectivity concerning action in motion, which motor appears in fantasy organization. Auto-empathy will deploy: process by which a subject puts himself instead of the other-in-self, producing an internalized view of self in order to represent his subjective world. The mediation of self-empathy process in virtual worlds will allow the subject to identify with the figure that represents him in the virtual worlds, so that his attention and empathy for this figure are turned indirectly towards himself. This second stage of virtual empathy for a self-figure, which we call self-empathy mediated by an avatar or virtual self-empathy, favors in a third time the development of empathy for oneself. Finally, in a fourth step in the multi-player online role-playing games, the development of a new form of intersubjective relationship work is favored: differentiating rather than sexual, engaging the action in proto-conversations rather than emotions between players and emerging from fantasy domain, the other player being always represented by the subject before being seen creates between players a desire for intersubjectivity through which the desire for a meeting in the real world of another player by putting in a fantasy in which imaginary representations are turned into figuration, also imaginary, of a real subject behind another avatar.NANTERRE-PARIS10-Bib. élec. (920509901) / SudocSudocFranceF

As três últimas sonatas de Franz Schubert D.958-959-960: interligações

O presente trabalho apresenta uma investigação realizada sobre as três últimas Sonatas de Franz Schubert para piano. É assumido que as mesmas devem ser consideradas como um todo, formando uma trilogia, e não como três obras distintas. Para isso são demonstradas Interligações de carácter Harmónico, Melódico e Rítmico bem como Interligações com outras obras de Schubert e Beethoven. São dadas também sugestões fundamentadas sobre a realização de uma performance da trilogia.This study presents an investigation into Schubert’s last three piano Sonatas. It is assumed that they should be considered as a whole, constituting a trilogy, and not as three distinctive works. For that, Harmonic, Melodic and Rhythmic Interconnections are shown as well as Interconnections with other works by Schubert and Beethoven. Also, well-grounded suggestions are made about performing the whole trilogy

The jet of the BL Lac object PKS 0521 -365 in the near-IR : MAD adaptive optics observations

BL Lac objects are low--power active nuclei exhibiting a variety of peculiar properties that are caused by the presence of a relativistic jet and orientation effects. We present here adaptive optics near-IR images at high spatial resolution of the nearby BL Lac object PKS 0521-365, which is known to display a prominent jet both at radio and optical frequencies. The observations were obtained in Ks--band using the ESO multi-conjugated adaptive optics demonstrator at the Very Large Telescope. This allowed us to obtain images with 0.1 arcsec effective resolution. We performed a detailed analysis of the jet and its related features from the near-IR images, and combined them with images previously obtained with HST in the R band and by a re-analysis of VLA radio maps. We find a remarkable similarity in the structure of the jet at radio, near-IR, and optical wavelengths. The broad--band emission of the jet knots is dominated by synchrotron radiation, while the nucleus also exhibits a significant inverse Compton component. We discovered the near-IR counterpart of the radio hotspot and found that the near-IR flux is consistent with being a synchrotron emission from radio to X-ray. The bright red object (red-tip), detached but well aligned with the jet, is well resolved in the near-IR and has a linear light profile. Since it has no radio counterpart, we propose that it is a background galaxy not associated with the jet. The new adaptive optics near-IR images and previous observations at other frequencies allow us to study the complex environment around the remarkable BL Lac object PKS 0521-365. These data exemplify the capabilities of multi conjugate adaptive optics observations of extragalactic extended sources.Comment: accepted for publication in Astronomy and Astrophysics 9 pages. A & A 2009, in pres

International Network for Capacity Building for the Control of Emerging Viral Vector-Borne Zoonotic Diseases: Arbo-Zoonet

Arboviruses are arthropod-borne viruses, which include West Nile fever virus (WNFV), a mosquito-borne virus, Rift Valley fever virus (RVFV), a mosquito-borne virus, and Crimean-Congo haemorrhagic fever virus (CCHFV), a tick-borne virus. These arthropod-borne viruses can cause disease in different domestic and wild animals and in humans, posing a threat to public health because of their epidemic and zoonotic potential. In recent decades, the geographical distribution of these diseases has expanded. Outbreaks of WNF have already occurred in Europe, especially in the Mediterranean basin. Moreover, CCHF is endemic in many European countries and serious outbreaks have occurred, particularly in the Balkans, Turkey and Southern Federal Districts of Russia. In 2000, RVF was reported for the first time outside the African continent, with cases being confirmed in Saudi Arabia and Yemen. This spread was probably caused by ruminant trade and highlights that there is a threat of expansion of the virus into other parts of Asia and Europe. In the light of global warming and globalisation of trade and travel, public interest in emerging zoonotic diseases has increased. This is especially evident regarding the geographical spread of vector-borne diseases. A multi-disciplinary approach is now imperative, and groups need to collaborate in an integrated manner that includes vector control, vaccination programmes, improved therapy strategies, diagnostic tools and surveillance, public awareness, capacity building and improvement of infrastructure in endemic regions