110 research outputs found
Host plant identification in the generalist xylem feeder Philaenus spumarius through gut content analysis
Balancing locality and concurrency: solving sparse triangular systems on GPUs
Many numerical optimisation problems rely on fast algorithms for solving sparse triangular systems of linear equations (STLs). To accelerate the solution of such equations, two types of approaches have been used: on GPUs, concurrency has been prioritised to the disadvantage of data locality, while on multi-core CPUs, data locality has been prioritised to the disadvantage of concurrency. In this paper, we discuss the interaction between data locality and concurrency in the solution of STLs on GPUs, and we present a new algorithm that balances both. We demonstrate empirically that, subject to there being enough concurrency available in the input matrix, our algorithm outperforms Nvidia’s concurrencyprioritising CUSPARSE algorithm for GPUs. Experimental results show a maximum speedup of 5.8-fold. Our solution algorithm, which we have implemented in OpenCL, requires a pre-processing phase that partitions the graph associated with the input matrix into sub-graphs, whose data can be stored in low-latency local memories. This preliminary analysis phase is expensive, but because it depends only on the input matrix, its cost can be amortised when solving for many different right-hand sides
Ability of Euscelidius variegatus to Transmit Flavescence Dorée Phytoplasma with a Short Latency Period
The mosaic leafhopper Orientus ishidae: host plants, spatial distribution, infectivity, and transmission of 16SrV phytoplasmas to vines
Orientus ishidae (Matsumura) is an Asian species introduced into Europe and recently associated with 16SrV phytoplasmas, related to grapevine “flavescence dorée”. Its life cycle, host plants, spatial distribution, infection and vector capability have been investigated in vine-growing areas of Piedmont, NW Italy. The spatial distribution of adults in vineyards was studied by applying interpolation methods to trap capture data. Insects were subject to molecular analyses to verify phytoplasma presence and identity. DNA extraction and PCR were made to detect 16SrV phytoplasmas. Transmission experiments were set up, using different sources for phytoplasma acquisition, and two plant species and an artificial diet for inoculation. Whole mount in situ hybridization was made to detect phytoplasmas in the salivary glands of adults. In the vineyard agro-ecosystem, 19 plant species (11 families), mainly broadleaf trees and shrubs, were recognized as host plants of the insect. Adults were more abundant on putative host plants than on grapevines, with a clear clustering at the edges of vineyards, and without a massive intrusion into the vineyard from outside. 16SrV phytoplasmas were detected only in adults captured with yellow sticky traps (20 out of 188 tested). The transmission of 16SrV phytoplasmas was successful after phytoplasma acquisition from infected broad bean and inoculation on grapevine
New insights in phytoplasma-vector interaction: acquisition and inoculation of flavescence dorée phytoplasma by Scaphoideus titanus adults in a short window of time
Tyrosinase Inhibitor Activity of Coumarin-Resveratrol Hybrids
In the present work we report on the contribution of the coumarin moiety to
tyrosinase inhibition. Coumarin-resveratrol hybrids 1-8 have been resynthesized to
investigate the structure-activity relationships and the IC50 values of these compounds
were measured. The results showed that these compounds exhibited tyrosinase inhibitory
activity. Compound 3-(3’,4’,5’-trihydroxyphenyl)-6,8-dihydroxycoumarin (8) is the most
potent compound (0.27 mM), more so than umbelliferone (0.42 mM), used as reference
compound. The kinetic studies revealed that compound 8 caused non-competitive
tyrosinase inhibition
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