Poissonian and non Poissonian Voronoi Diagrams with application to the aggregation of molecules

The distributions that regulate the spatial domains of the Poissonian Voronoi Diagrams are discussed adopting the sum of gamma variate of argument two. The distributions that arise from the product and quotient of two gamma variates of argument two are also derived. Three examples of non Poissonian seeds for the Voronoi Diagrams are discussed. The developed algorithm allows the simulation of an aggregation of methanol and water.Comment: 18 pages 10 Figure

On the statistics of area size in two-dimensional thick Voronoi Diagrams

Cells of Voronoi diagrams in two dimensions are usually considered as having edges of zero width. However, this is not the case in several experimental situations in which the thickness of the edges of the cells is relatively large. In this paper, the concept of a thick Voronoi tessellation, that is with edges of non-zero width, is introduced and the the statistics of cell areas, as thickness changes, are analyzed.Comment: 14 pages, 9 figure

Measurements of Non-Wetting Phase Trapping Applied to Carbon Dioxide Storage

We measure the trapped non-wetting phase saturation as a function of the initial saturation in sand packs. The application of the work is for carbon dioxide (CO2) storage in aquifers where capillary trapping is a rapid and effective mechanism to render injected CO2 immobile. We used analogue fluids at ambient conditions. The trapped saturation initially rises linearly with initial saturation to a value of 0.11 for oil/water systems and 0.14 for gas/water systems. There then follows a region where the residual saturation is constant with further increases in initial saturation

Infection and genotype remodel the entire soybean transcriptome

<p>Abstract</p> <p>Background</p> <p>High throughput methods, such as high density oligonucleotide microarray measurements of mRNA levels, are popular and critical to genome scale analysis and systems biology. However understanding the results of these analyses and in particular understanding the very wide range of levels of transcriptional changes observed is still a significant challenge. Many researchers still use an arbitrary cut off such as two-fold in order to identify changes that may be biologically significant. We have used a very large-scale microarray experiment involving 72 biological replicates to analyze the response of soybean plants to infection by the pathogen <it>Phytophthora sojae </it>and to analyze transcriptional modulation as a result of genotypic variation.</p> <p>Results</p> <p>With the unprecedented level of statistical sensitivity provided by the high degree of replication, we show unambiguously that almost the entire plant genome (97 to 99% of all detectable genes) undergoes transcriptional modulation in response to infection and genetic variation. The majority of the transcriptional differences are less than two-fold in magnitude. We show that low amplitude modulation of gene expression (less than two-fold changes) is highly statistically significant and consistent across biological replicates, even for modulations of less than 20%. Our results are consistent through two different normalization methods and two different statistical analysis procedures.</p> <p>Conclusion</p> <p>Our findings demonstrate that the entire plant genome undergoes transcriptional modulation in response to infection and genetic variation. The pervasive low-magnitude remodeling of the transcriptome may be an integral component of physiological adaptation in soybean, and in all eukaryotes.</p

Enhanced permeability due to apparent oil/brine slippage in limestone and its dependence on wettability

Acknowledgments This material includes work supported by a Society of Petrophysicists and Well Log Analysts Foundation grant and an Aberdeen Formation Evaluation Society scholarship. M.C. was supported by a University of Aberdeen College of Physical Sciences studentship. The authors gratefully acknowledge Amer Syed for his assistance with the assembly and maintenance of the coreflood rigs, Jim Anderson for helpful discussions, and the two anonymous reviewers for their comments and suggestions. All data used in this study will be made available from the corresponding author upon request.Peer reviewedPublisher PD