Emergence and reemergence of tomato begomoviruses in the North-East of Morocco

In Morocco, Tomato yellow leaf curl disease (Tylc) has emerged in 1997 [1]. Two begomovirus species causing Tylc were identified, Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Sardinia virus (TYLCSV) [2]. Due to cold winters in North East of Morocco, tomato cannot be grown year round and the populations of the vector Bemisia tabaci are drastically reduced during this season. However, Tylc reemerges every year in the new tomato crops in July and incidences may reach up to 100% in September. The objective of the study was: (i) to assess the relative importance of TYLCV and TYLCSV, (ii) to understand how these viruses are overwintering, and (iii) to estimate the risk of recombinant emergence between TYLCV and TYLCSV. The relative incidence of TYLCV and TYLCSV was estimated with leaf samples collected from 2003 onwards. Among tomato plants exhibiting the typical Tylc symptoms, more than 99% were infected with TYLCV and less than 1% with TYLCSV. Among the weed plants which were detected positive for TYLCV or TYLCSV, 85% were infected with TYLCSV and 15% with TYLCV. The tests of some tomato samples collected in 2001 revealed that shortly after the emergence of Tylc, TYLCSV was detected more frequently, suggesting that TYLCV has partially displaced TYLCSV from tomato. Leaf samples were also collected in winter to detect potential reservoirs of Tylc. TYLCSV was detected on several weeds and on two winter crops, pea and faba bean. However, TYLCV was detected only on the two cultivated hosts and only in mixed infection with TYLCSV. The reemergence of TYLCV in tomato may be due to its overwintering in pea and faba bean. The risk of emergence of TYLCV/TYLCSV recombinants is high, because several plants species were found to be coinfected with these two viruses: tomato, winter crops, and weeds. The risk is increased by the fact that the winter survival of TYLCV, the most damaging virus of tomato, is apparently dependent of its switching to plant species which are the preferred hosts of TYLCSV. We are presently looking for recombinants in field samples of cultivated or weed plants which were detected positive for both TYLCV and TYLCSV. (Résumé d'auteur

Mise au point de deux tests PCR multiplexes pour détecter simultanément des formes recombinantes et non-recombinantes du Tomato yellow leaf curl virus au Maroc

Le Tomato yellow leaf curl virus (TYLCV, genre Begomvirus, famille Geminiviridae) a été isolé pour la première fois au Maroc en 1998 (Peterschmitt et al., 1999) et le Tomato yellow leaf curl Sardinia virus (TYLCSV) en 1999 (Monci et al., 2000). La gravité des attaques de la tomate par ces virus a obligé les agriculteurs à cultiver la tomate sous serre insectproof et à progressivement remplacer les variétés traditionnelles par des variétés tolérantes. Le TYLCV et le TYLCSV étant des virus hautement recombinogènes (Garcia Andres et al., 2007), le risque d'une émergence de recombinants TYLCV/TYLCSV dans une zone infestée par les deux virus était considéré comme très élevé. Pour confirmer ce risque, nous avons mis au point deux tests PCR multiplexes permettant l'identification de tels recombinants. De plus, pour obtenir une première estimation du potentiel d'émergence de ces recombinants ? les recombinants sont-il détectés seuls ou en co-infection avec les parents ? ? les tests ont été conçus pour cibler simultanément les recombinants potentiels et les virus parentaux. Outre la description de la technique, nous présenterons aussi quelques résultats préliminaires qui ont permis de valider la technique. (Texte intégral

Emerg. Infect. Dis

The multidrug-resistant (MDR) Salmonella enterica serotype Newport strain that produces CMY-2 β-lactamase(Newport MDR-AmpC) was the source of sporadic cases and outbreaks in humans in France during 2000–2005. Because this strain was not detected in food animals, it was most likely introduced into France through imported food products

Mitochondrial proteomics: analysis of a whole mitochondrial extract with two-dimensional electrophoresis

Mitochondria are complex organelles, and their proteomics analysis requires a combination of techniques. The emphasis in this chapter is made first on mitochondria preparation from cultured mammalian cells, then on the separation of the mitochondrial proteins with two-dimensional electrophoresis (2DE), showing some adjustment over the classical techniques to improve resolution of the mitochondrial proteins. This covers both the protein solubilization, the electrophoretic part per se, and the protein detection on the gels, which makes the interface with the protein identification part relying on mass spectrometry

Réutilisation maîtrisée des eaux usées : approfondir les connaissances pour lever les freins et relever les défis

Le recyclage des eaux usées représente une solution pour faire face à la demande croissante des ressources hydriques pour l’irrigation agricole. Mais leur réutilisation pose des problèmes de sécurité, de réglementation et bien sûr de techniques adaptées, que cet article nous propose de mieux comprendre

Méthode d'évaluation de l'action de conseil en irrigation IRRIPARC en régions Nord-Pas-de-Calais et Picardie

Parmi les nombreuses actions de conseil en irrigation développées en France, trop peu d'entre elles sont évaluées pour apprécier leur impact sur les pratiques d'irrigation et les bénéfices pour la ressource. Dans cet article, nous proposons une méthode d'évaluation de l'une d'entre elles, sur l'étude d'un cas concret : l'action IRRIPARC. Dans les régions Nord-Pas-de-Calais et Picardie, des fiches de réglages de canons enrouleurs ont été diffusées aux agriculteurs, pour limiter les effets du vent sur l'uniformité de la répartition de l'eau d'irrigation. La méthode d'évaluation proposée repose sur l'étude de trois critères : l'efficacité, la pertinence et la cohérence de l'action. La collecte des données se fait par enquêtes quantitatives et qualitatives auprès de différents acteurs : les agriculteurs, public cible de l'action, et les partenaires impliqués dans l'action IRRIPARC. L'analyse débouche sur des perspectives d'évolution et fournit des recommandations pour l'action. / Several technical support actions in irrigation have been carried out in France. However, very few have been evaluated to determine their actual impact on irrigation practices and their water saving benefits. In this paper, an assessment method of a technical support action is presented on a concrete case: the IRRIPARC action. The action was carried in the Nord Pas-de-Calais region of France. It aims at providing to farmers technical forms to help them to set their irrigation guns according to the wind speed in order to improve water distribution uniformity. The method depends on three criteria based on the effectiveness, the relevance and the consistency of the action. The data have been collected through quantitative and qualitative enquiries to different stakeholders: farmers to which the action was intended, and other partners which were involved in the action. The analysis results in evolution perspective of IRRIPARC action

Integrating Al with NiO nano honeycomb to realize an energetic material on silicon substrate

Nano energetic materials offer improved performance in energy release, ignition, and mechanical properties compared to their bulk or micro counterparts. In this study, the authors propose an approach to synthesize an Al/NiO based nano energetic material which is fully compatible with a microsystem. A two-dimensional NiO nano honeycomb is first realized by thermal oxidation of a Ni thin film deposited onto a silicon substrate by thermal evaporation. Then the NiO nano honeycomb is integrated with an Al that is deposited by thermal evaporation to realize an Al/NiO based nano energetic material. This approach has several advantages over previous investigations, such as lower ignition temperature, enhanced interfacial contact area, reduced impurities and Al oxidation, tailored dimensions, and easier integration into a microsystem to realize functional devices. The synthesized Al/NiO based nano energetic material is characterized by scanning electron microscopy, X-ray diffraction, differential thermal analysis, and differential scanning calorimetry

Status and overview of development of the Silicon Pixel Detector for the PHENIX experiment at the BNL RHIC

We have developed a silicon pixel detector to enhance the physics capabilities of the PHENIX experiment. This detector, consisting of two layers of sensors, will be installed around the beam pipe at the collision point and covers a pseudo-rapidity of | \eta | < 1.2 and an azimuth angle of | \phi | ~ 2{\pi}. The detector uses 200 um thick silicon sensors and readout chips developed for the ALICE experiment. In order to meet the PHENIX DAQ readout requirements, it is necessary to read out 4 readout chips in parallel. The physics goals of PHENIX require that radiation thickness of the detector be minimized. To meet these criteria, the detector has been designed and developed. In this paper, we report the current status of the development, especially the development of the low-mass readout bus and the front-end readout electronics.Comment: 9 pages, 8 figures and 1 table in DOCX (Word 2007); PIXEL 2008 workshop proceedings, will be published in the Proceedings Section of JINST(Journal of Instrumentation

PHENIX Highlights

Recent highlights of measurements by the PHENIX experiment at RHIC are presented.Comment: 8 pages, 9 figures. Talk at Quark Matter 200

J/psi suppression at forward rapidity in Au+Au collisions at sqrt(s_NN)=39 and 62.4 GeV

We present measurements of the J/psi invariant yields in sqrt(s_NN)=39 and 62.4 GeV Au+Au collisions at forward rapidity (1.2<|y|<2.2). Invariant yields are presented as a function of both collision centrality and transverse momentum. Nuclear modifications are obtained for central relative to peripheral Au+Au collisions (R_CP) and for various centrality selections in Au+Au relative to scaled p+p cross sections obtained from other measurements (R_AA). The observed suppression patterns at 39 and 62.4 GeV are quite similar to those previously measured at 200 GeV. This similar suppression presents a challenge to theoretical models that contain various competing mechanisms with different energy dependencies, some of which cause suppression and others enhancement.Comment: 365 authors, 10 pages, 11 figures, 4 tables. Submitted to Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm