Ex vivo bioluminescent detection of alcelaphine herpesvirus 1 infection during malignant catarrhal fever induced in rabbits

Poster (2009, December 11)

Alcelaphine herpesvirus 1 (AlHV-1), carried by wildebeest asymptomatically, causes malignant catarrhal fever (WD-MCF) when cross-species transmitted to a variety of susceptible species of the Artiodactyla ... [more ▼]

Alcelaphine herpesvirus 1 (AlHV-1), carried by wildebeest asymptomatically, causes malignant catarrhal fever (WD-MCF) when cross-species transmitted to a variety of susceptible species of the Artiodactyla order. Experimentally, WD-MCF can be reproduced in rabbits. The lesions observed are very similar to those described in natural host species. Recently, we demonstrated that WD-MCF induced by AlHV-1 in rabbits is associated with the proliferation of CD8+ cells supporting a latent type of infection. In the present study, we investigated whether the virus could be detected ex vivo in the tissues of rabbits developing WD-MCF. Taking advantage of the recent cloning of the AlHV-1 genome as a bacterial artificial chromosome (BAC), we produced a recombinant plasmid encoding a firefly luciferase (LUC) expression cassette inserted in a non-coding region of the AlHV-1 genome. In vitro, the reconstituted AlHV-1 LUC strain replicated comparably to the parental strain in permissive cells and was able to induce a bioluminescent signal. In vivo, rabbits infected with the AlHV-1 LUC strain developed WD-MCF similarly to the parental wild-type strain with hyperthermia, increased CD8/CD4 ratio and viral genomic charge over time in PBMC and in lymph nodes at time of death. To identify the presence of AlHV-1 infection ex vivo, various organs of infected rabbits developing WD-MCF were analysed by bioluminescent imaging. Luciferase activity could be detected macroscopically at the time of death in most of analyzed organs including lung, popliteal and mesenteric lymph nodes, spleen, liver, kidney and appendix. Infectious virus could be isolated following co-cultures of lymph node and permissive cells, and the isolated virus retained the ability to induce a bioluminescent signal. In conclusion, we produced an AlHV-1 LUC recombinant and we were able to detect the AlHV-1 infection ex vivo in many organs at the time of death. [less ▲]

Evolution des pratiques d'évaluation : le cas des sciences astrophysiques

Conference (2009, December 10)

Main brain damages in the premature and at term newborns: pathophysiology an treatment

Learning material (2009)

Retroconversion of a Complex Etymological Dictionary

Scientific conference (2009, December 10)

Neural correlates of personal goal processing when envisioning future events

Conference (2009, December 10)

Multifunctional coatings

Patent (2009)

New polyelectrolyte copolymer, composite material, multilayer film and substrate carrying such polyelectrolyte copolymer, composite and multilayer film wherein the polyelectrolyte copolymer comprises a) a ... [more ▼]

New polyelectrolyte copolymer, composite material, multilayer film and substrate carrying such polyelectrolyte copolymer, composite and multilayer film wherein the polyelectrolyte copolymer comprises a) a first type of identical or different units (A) each comprising one or more dihydroxyphenyl groups such that sidechains are present along the backbone of the polyelectrolyte copolymer which contain at least one dihydroxyphenyl group each; and (b1) a second type of identical or different units (B1) each comprising a cationic moiety, or (b2) a second type of identical or different units (B2) each comprising an anionic moiety. [less ▲]

Biomarker for osteoarthritis and/or other ageing-related diseases, and use thereof

Patent (2009)

The invention relates to the identification of a biomarker whose abundance in bodily fluids is changed in subjects with osteoarthritis and/or other ageing-related diseases. The biomarker has applications ... [more ▼]

The invention relates to the identification of a biomarker whose abundance in bodily fluids is changed in subjects with osteoarthritis and/or other ageing-related diseases. The biomarker has applications in the diagnosis of osteoarthritis and/or other ageing-related diseases, in determining the prognosis for an individual diagnosed with osteoarthritis and/or other ageing-related diseases, and in monitoring the efficacy of treatment for osteoarthritis and/or other ageing-related diseases. [less ▲]

Cyanobacterial diversity and distribution in aquatic microbial mats in Antarctica assessed by DGGE

Scientific conference (2009, December 09)

Gravitationally lensed quasars: light curves, observational constraints, modeling and the Hubble constant.

Doctoral thesis (2009)

The central topic of this thesis is gravitational lensing, a phenomenon that occurs when light rays from a background source pass near a massive object located on the line of sight and are deflected. It ... [more ▼]

The central topic of this thesis is gravitational lensing, a phenomenon that occurs when light rays from a background source pass near a massive object located on the line of sight and are deflected. It is one of the most wonderful observational fact in favour of the General Theory of Relativity (Einstein, 1916). This phenomenon constitutes a powerful tool to probe different areas in astrophysics, including cosmology, which is our main interest. In particular we study gravitationally lensed quasars. Refsdal (1964) was the first to state that time delays between different lensed images of the same object, if this one is intrisically variable, can lead to the measurement of the Hubble constant H0, which is related the actual expansion rate of the Universe. Up to now, only a few lensed quasars have led to H0 and the precision on it has never reached the one obtained with other methods as the ones based on the Cosmic Distance Ladder. That is why some scientists from around the globe decided to unite their force to measure H0 from about thirty lensed quasars. To reach that goal, these objects are being monitored with some mid-sized ground-based telescopes located in both hemispheres. This thesis is realised in the framework of this collaboration called COSMOGRAIL for COSmological MOnitoring of GRAvItational Lenses. This work focuses on image processing and on several steps mandatory to obtain a measurement of H0 from lensed quasars: the acquisiton of the light curves from which it is possible to extract the time delays and the acquisition of the observational constraints necessary to model the gravitational potential responsible for the observed configura- tion. The central technique of this work is the image deconvolution with the MCS algorithm (Magain, Courbin & Sohy, 1998). The main principle of this algorithm is the non-violation of the sampling theorem in trying to obtain a better resolution in the deconvolved frame instead of an infinite one. The final resolution in the deconvolved frame is chosen by the user and as it is known, every image is decomposed in a contri- bution from the point sources and another one from all the extended structures such as arcs, rings and galaxies. To obtain good light curves from data coming from several telescopes, good reduction procedures are needed. That is why Vuissoz (2008) developed a semi-automated reduc- tion pipeline including deconvolution with the MCS algorithm. In the framework of the i ii Abstract present thesis, we adapt it to one of the telescopes used by the collaboration whose data were never used before, i.e. the Mercator telescope. We also bring some modifications to this pipeline, e.g. concerning the estimation of the error on the magnitudes of the light curves. We apply this revised version of the reduction pipeline to HE 0435-1223, a quadruply imaged quasar with already measured time delays (Kochanek et al., 2006). Another object, the quad WFI J2026-4536, is then investigated: we obtain light curves for each of the four lensed images. Thanks to the CASTLES project (Cfa-Arizona Space Telescope LEns Survey1), many lensed quasars have been observed with the camera 2 of NICMOS (Near Infrared Camera and Multi-Object Spectrometer ) on board the Hubble Space Telescope. With these high resolution images, we can obtain very accurate constraints on the geometry of the lensed systems. But most of the time no star is available in the field of view to obtain a good Point Spread Function (PSF). That is why we develop an iterative strategy combined with the MCS algorithm: we call it ISMCS. This technique allows to use the lensed images themselves to improve the PSFs step by step while simultaneously deconvolving the frame to obtain better estimations of the extended structures in the image. We first test this strategy on a quadruply imaged quasar, the Cloverleaf gravitational lens (H1413+117), and obtain relative positions precise to 1 milliarcsecond (mas). We then apply ISMCS to the quadruply imaged quasar WFI J2033-4723 in order to con- tribute to the estimate of the Hubble constant, as this object was monitored by our team. We then study a sample of seven lensed systems currently monitored by COSMOGRAIL and for which time delays have never been obtained. Here again, we obtain positional constraints with an accuracy of around 1 to 2 mas thanks to the application of ISMCS. We then model these systems with simple mass profiles for the main lens galaxy and obtain an estimation of the values of the time delays. Finally we apply ISMCS to a sample of eleven lensed quasars which already have measured time delays. When the delays have been remeasured by our team, in four cases until now, we also model the potential of the lens with simple mass profiles to estimate H0. 1http://www.cfa.harvard.edu/castles [less ▲]

Retroconversion of a Complex Etymological Dictionary

Scientific conference (2009, December 08)