Source of Hyalesthes obsoletus Signoret planthopper (Hemiptera: Cixiidae) in southern France and potential effects of landscape.

Cixiid planthoppers are considered of major economic importance, as they can transmit phytoplasmas responsible for many plant diseases. While thorougly studied in vineyards, the epidemiology of stolbur phytoplasma, transmitted by Hyalesthes obsoletus Signoret, was rarely investigated on minor crops as lavender, where it leads to 'yellow decline' disease and large economic losses. The objective of this paper is to understand the effect of the local landscape characteristics on the presence and density of H. obsoletus in the 'Plateau de Valensole', southern France. Potential host plants of H. obsoletus were surveyed in three contrasted zones (in terms of crops and disease intensity), by uprooting plants and capturing adults in emergence traps. The localization and potential movements of H. obsoletus from the host plants towards lavandin (infertile hybrid of lavender) were determined using yellow sticky traps. Clary sage plants were found as major hosts of H. obsoletus. Flying insects were also caught in fields of lavandin, although emergence traps and plant uprooting did not confirm this crop as a winter host, i.e., as a reservoir for the insect. Based on one zone, we showed that attractiveness may depend on crop (clary sage or lavandin) and on its age, as well as on the distance to the supposed source field. These results suggest that clary sage could be an important host of H. obsoletus, whose density largely varies between zones. Genetic studies would be required to confirm the role of clary sage in the dissemination of yellow decline of lavandin.

ViralORFeome: an integrated database to generate a versatile collection of viral ORFs.

Large collections of protein-encoding open reading frames (ORFs) established in a versatile recombination-based cloning system have been instrumental to study protein functions in high-throughput assays. Such 'ORFeome' resources have been developed for several organisms but in virology, plasmid collections covering a significant fraction of the virosphere are still needed. In this perspective, we present ViralORFeome 1.0 (http://www.viralorfeome.com), an open-access database and management system that provides an integrated set of bioinformatic tools to clone viral ORFs in the Gateway(R) system. ViralORFeome provides a convenient interface to navigate through virus genome sequences, to design ORF-specific cloning primers, to validate the sequence of generated constructs and to browse established collections of virus ORFs. Most importantly, ViralORFeome has been designed to manage all possible variants or mutants of a given ORF so that the cloning procedure can be applied to any emerging virus strain. A subset of plasmid constructs generated with ViralORFeome platform has been tested with success for heterologous protein expression in different expression systems at proteome scale. ViralORFeome should provide our community with a framework to establish a large collection of virus ORF clones, an instrumental resource to determine functions, activities and binding partners of viral proteins.

An alternative method of particulate fluorescent tracer analysis in sediments using a microplate fluorimeter.

Conservative particulate fluorescent tracers (e.g. luminophores and microspheres) are commonly used in a wide range of sediment transport studies. Traditionally, their spatial redistribution is estimated by counting them in sediments under ultraviolet light (e.g. by epifluorescence microscopy), a time-consuming but effective method. While alternative methods have recently been developed (e.g. photodetection, digital image analyses), this 'classical' counting method remains the most commonly used. This article describes an alternative procedure for measuring the concentration of fluorescent tracers (here, microspheres) using a microplate fluorimeter. This technique enables simultaneous analysis of numerous samples while reducing the sediment preparation and quantification time. After a calibration step from sediment samples with known microsphere content, the method was validated by comparing results from the epifluorescence microscopy method. Different adjustments were also reported, as well as application examples. The different calibration tests showed high linear relationships between the microsphere concentration of sediment samples and the measured fluorimetric intensities (R2-0.99) with a detection limit of 6%. In comparison with the previously used method, very similar results were obtained, as illustrated in recent studies using both luminophores and microspheres. The rapid and reliable method proposed here will enable increasingly complex experiments to be performed with less time-consuming qualitative analyses.

[Endoscopy of the small intestine in 1991: is it the end of the tunnel?]. / L'endoscopie de l'intestin grêle en 1991: est-ce la fin du tunnel?

Small bowel enteroscopy in 1991 is now feasible in two clinical situations: in the case of malabsorption or diffuse intestinal disease, it is easier to visualise the small bowel with the "push enteroscopy methods". The most proximal and distal ends of the small intestine can be viewed through standard instruments or better with videocoloscope beyond the ligament of Treitz. The ileocecal valve can be intubated after total colonoscopy for the evaluation of Crohn's disease, tuberculosis and small bowel lymphoma. In the case of occult gastrointestinal hemorrhage small bowel enteroscopy now permits visualization of large amounts of small intestinal. When the gastrointestinal bleeding is severe, we recommend intraoperative enteroscopy. When the bleeding is not severe and chronic, it is possible to perform a non surgical total small bowel enteroscopy with an enteroscope or videoenteroscopoe. Prototypes are under development. The procedure is safe an can be performed on an outpatient basis. The limitations of the procedure are the impossibility of intervention and inability to inspect the total mucosal surface. It is not a "first line" or "second line" investigation in these situations. It should be considered after previous investigations have been negative. Push enteroscopy should be performed by general endoscopists, non surgical and total enteroscopy should be reserved, for instance for skills and motivated team endoscopists.