15,643 research outputs found

    Some Relationships between Discrete and Continuous Models of an Urban Economy

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    Influence of pore-scale disorder on viscous fingering during drainage

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    We study viscous fingering during drainage experiments in linear Hele-Shaw cells filled with a random porous medium. The central zone of the cell is found to be statistically more occupied than the average, and to have a lateral width of 40% of the system width, irrespectively of the capillary number CaCa. A crossover length wfCa1w_f \propto Ca^{-1} separates lower scales where the invader's fractal dimension D1.83D\simeq1.83 is identical to capillary fingering, and larger scales where the dimension is found to be D1.53D\simeq1.53. The lateral width and the large scale dimension are lower than the results for Diffusion Limited Aggregation, but can be explained in terms of Dielectric Breakdown Model. Indeed, we show that when averaging over the quenched disorder in capillary thresholds, an effective law v(P)2v\propto (\nabla P)^2 relates the average interface growth rate and the local pressure gradient.Comment: 4 pages, 4 figures, submitted to Phys Rev Letter

    Large-scale and significant expression from pseudogenes in Sodalis glossinidius – a facultative bacterial endosymbiont

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    The majority of bacterial genomes have high coding efficiencies, but there are some genomes of intracellular bacteria that have low gene density. The genome of the endosymbiont Sodalis glossinidius contains almost 50 % pseudogenes containing mutations that putatively silence them at the genomic level. We have applied multiple ‘omic’ strategies, combining Illumina and Pacific Biosciences Single-Molecule Real-Time DNA sequencing and annotation, stranded RNA sequencing and proteome analysis to better understand the transcriptional and translational landscape of Sodalis pseudogenes, and potential mechanisms for their control. Between 53 and 74 % of the Sodalis transcriptome remains active in cell-free culture. The mean sense transcription from coding domain sequences (CDSs) is four times greater than that from pseudogenes. Comparative genomic analysis of six Illumina-sequenced Sodalis isolates from different host Glossina species shows pseudogenes make up ~40 % of the 2729 genes in the core genome, suggesting that they are stable and/or that Sodalis is a recent introduction across the genus Glossina as a facultative symbiont. These data shed further light on the importance of transcriptional and translational control in deciphering host–microbe interactions. The combination of genomics, transcriptomics and proteomics gives a multidimensional perspective for studying prokaryotic genomes with a view to elucidating evolutionary adaptation to novel environmental niches

    Windtunnel and field observations of western spruce budworm responses to pheromone-baited traps

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    Five trap designs, the Pherocon 1CP, a triangular trap, dome trap, double cone trap and Kendall trap were evaluated for capturing the western spruce budworm, <i>Choristoneura occidentalis</i> Freeman, both in a laboratory-based windtunnel and in an infested stand. Neutral density smoke tests showed the effects of orientation to wind on plume formation as well as highlighting plume structure around larger traps. Moth capture rates in the windtunnel did not always correlate with capture rates under field conditions

    Analysis of direct segregated boundary-domain integral equations for variable-coefficient mixed bvps in exterior domains

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    This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2013 World Scientific Publishing.Direct segregated systems of boundary-domain integral equations are formulated for the mixed (Dirichlet–Neumann) boundary value problems for a scalar second-order divergent elliptic partial differential equation with a variable coefficient in an exterior three-dimensional domain. The boundary-domain integral equation system equivalence to the original boundary value problems and the Fredholm properties and invertibility of the corresponding boundary-domain integral operators are analyzed in weighted Sobolev spaces suitable for infinite domains. This analysis is based on the corresponding properties of the BVPs in weighted Sobolev spaces that are proved as well.The work was supported by the grant EP/H020497/1 \Mathematical analysis of localised boundary-domain integral equations for BVPs with variable coefficients" of the EPSRC, UK

    Plant viruses.

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    Clover viruses, 82ES38, 82AL47, 82MA19, 82BR19, 82BY29; 82BU5, 82HA9. Lupin virus, diseases. Barley yellow dwarf virus, 82AL46, 82AL51, 82B10, 82BA33, 82BR16, 82BR18, 82C29, 82E27, 82ES37, 82ES40, 82JE19, 82JE20, 82KA33, 82KA34, 82ABI3, 82MA18, 82MN22, 82MT34, 82NA32, 82WH28,82B8, 82MN17, 82E24, 82MT30, 82E25, 82MN18, 82MT31, 82B9, 82ABI2, 82BA31, 82C26, 82JE17, 82WH27, 82AL45, 82BR17, 82ES39, 82MA1, 82MA117, 82MT33

    An Application of the KhachianShor Algorithm to a Class of Linear Complementary Problems

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    The recent ellipsoidal method for solving linear programs due to Khachian and Shor is shown to process linear complementarity problems with positive semidefinite matrix. Suitable modifications of all lemmas are presented and it is shown that the algorithm operates in polynomial time of the same order as that required for linear programming. Thus quadratic programming problems are solvable in polynomial time

    1981 Plant viruses

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    1, Clover viruses - 81HA6, 81MA9, 81BR14, 81BY12, 81BH5, 81AL38, 81ES39 OBJECTIVES: To determine the extent of the \u27Dinninup virus\u27 problem (sub. clover mottle). To further assess the incidence of red leaf virus to determine the incidence of bean yellow mosaic virus. To note the incidence of sub. clover stunt virus. A. BYDV: Survey of incidence - 81BU1, 81BU2, 81BR11, 81BR12, 81MA6, 81MA7, 81AL31, 81AL32, 81JE14, 81JE15, 81KA21, 81KA22, 81NA28, 81N031, 81ES38, 81E26. 2. Barley yellow dwarf virus. BYDV: Genotype x insecticide studies - 81MN14, 81MT29, 81E28, 81MN14. BYDV: differences amongst barley genotypes - 81C19, 81WH31, 81BA30. BYDV: Resistance and yield in CV.Shannon and CV. Proctor - 871BR13, 81MA8, 81AL36, 81JE17 Yield per plot and 100 seed weight - Albany 81AL36 Infection of BYDV in cereal genotypes at Manjimup ( 81MN13)
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