Molecular approaches to the analysis of deformed wing virus replication and pathogenesis in the honey bee, Apis mellifera

<p>Abstract</p> <p>Background</p> <p>For years, the understanding of the pathogenetic mechanisms that underlie honey bee viral diseases has been severely hindered because of the lack of a cell culture system for virus propagation. As a result, it is very imperative to develop new methods that would permit the <it>in vitro </it>pathogenesis study of honey bee viruses. The identification of virus replication is an important step towards the understanding of the pathogenesis process of viruses in their respective hosts. In the present study, we developed a strand-specific RT-PCR-based method for analysis of Deformed Wing Virus (DWV) replication in honey bees and in honey bee parasitic mites, <it>Varroa Destructor</it>.</p> <p>Results</p> <p>The results shows that the method developed in our study allows reliable identification of the virus replication and solves the problem of falsely-primed cDNA amplifications that commonly exists in the current system. Using TaqMan real-time quantitative RT-PCR incorporated with biotinylated primers and magnetic beads purification step, we characterized the replication and tissue tropism of DWV infection in honey bees. We provide evidence for DWV replication in the tissues of wings, head, thorax, legs, hemolymph, and gut of honey bees and also in Varroa mites.</p> <p>Conclusion</p> <p>The strategy reported in the present study forms a model system for studying bee virus replication, pathogenesis and immunity. This study should be a significant contribution to the goal of achieving a better understanding of virus pathogenesis in honey bees and to the design of appropriate control measures for bee populations at risk to virus infections.</p

LHCb tracker upgrade technical design report

The upgrade of the LHCb detector will extend the physics reach of the experiment by allowing it to run at higher luminosity, Linst = 2 x 1033 cm\uf02d2 s\uf02d1, with increased trigger e_ciency for a wide range of decay channels. This is facilitated by the implementation of new front-end electronics, designed such that complete events can be read out and sent to the LHCb data acquisition farm for selection by a full software trigger, every 25 ns. The upgraded LHCb detector is conceived to take physics data for an integrated luminosity of at least 50 fb bc0 c001. This Technical Design Report describes in detail the upgrade of the two tracking subsystems, located just before and just after the LHCb dipole magnet. The tracking detector before the magnet (the Upstream Tracker) will be composed of new, high-granularity silicon micro-strip planes with an improved coverage of the LHCb acceptance. Behind the magnet, a Scintillating Fibre Tracker will be built, which is composed of 2.5m long _bres read out by silicon photomultipliers at the edge of the acceptance. The performance of the two tracking detectors and of the LHCb tracking software are presented, as well as the cost, schedule and task sharing

LHCb particle identification upgrade technical design report

The LHCb upgrade will take place in the second long shutdown of the LHC, currently scheduled to begin in 2018. The upgrade will enable the experiment to run at luminosities of 2 x 10^33cm^-2s^-1 and will read out data at a rate of 40MHz into a flexible software-based trigger. All sub-detectors of LHCb will be re-designed to comply with these new operating conditions. This Technical Design Report presents the upgrade plans of the Ring Imaging Cherenkov (RICH) system, the calorimeter system and the muon system, which together provide the particle identification capabilities of the experiment

LHCb VELO upgrade technical design report

The upgraded LHCb VELO silicon vertex detector is a lightweight hybrid pixel detector capable of 40 MHz readout at a luminosity of 2 x 10^33 cm^-2 s^-1. The track reconstruction speed and precision is enhanced relative to the current VELO detector even at the high occupancy conditions of the upgrade, due to the pixel geometry and a closest distance of approach to the LHC beams of just 5.1 mm for the first sensitive pixel. Cooling is provided by evaporative CO2 circulating in microchannel cooling substrates. The detector contains 41 million 55 um x 55 um pixels, read out by the custom developed VeloPix front end ASIC. The detector will start operation together with the rest of the upgraded LHCb experiment after the LHC LS2 shutdown, currently scheduled to end in 2019. This Technical Design Report describes the upgraded VELO system, planned construction and installation, and gives an overview of the expected detector performance