This study determined the key characteristics of temporal patterns of root growth during the crop development period, as well as the vertical patterns of root distribution in the soil profile for important oilseed and pulse crops grown on the semiarid Canadian Prairie. Rooting characteristics greatly influence the nutrient acquisition and water-use patterns for any plants. However, crop root systems have not been studied intensively due to time, labor and costs constraints. In the literature, root studies mostly focus on cereal crops and very limited information is available for oilseeds and pulses even though these broadleaf crops are critical in the diversification of cropping systems. Thus the objectives of this study were to 1) examine the root morphological characteristics, root distribution patterns in the soil profile, and the fine root distributions of oilseeds and pulses in comparison with wheat; 2) to determine the rhizospheric properties of pulse crops. In 2006 and 2007, canola (<i>Brassica napus</i> L.), flax (<i>Linum usitatissimum</i> L.), mustard (<i>Brassica juncea</i> L.), chickpea (<i>Cicer arietinum </i> L.), field pea (<i>Pisum sativum</i>L., lentil (<i>Lens culinaris</i>), and spring wheat (<i>Triticum aestivum</i> L.) were grown under low- (natural rainfall) and high-water (rainfall+irrigation) conditions in southwest Saskatchewan. Roots were sampled at the seedling, early-flower, late-flower, late-pod, and physiological maturity growth stages, and root parameters determined using image analysis. The growth of roots progressed markedly from seedling to late-flowering and then declined to maturity. Root growth of pulse crops was not significantly affected by water conditions, but canola had 70% greater root length, 67% more root surface area, and 79% more root tips under high-water than under low-water conditions. At the late-flower stage, over 70% of the roots in oilseeds and pulses were distributed within the 0-60 cm soil profile and the largest proportion (around 50%) were found in the top 20-cm of the soil depth. About 85% of the roots in oilseeds and pulses were classified as extra fine (diameter <0.4mm). The rhizosphere fungi were significantly different among tested pulses and also pulse rhizosphere fungi were significantly affected by soil depth but not by water conditions. Inoculation of <i>Penicillium bilaiae</i> (product -JumpStart®) to the pulse crops increased the amount of the fungi in their rhizospheres by as much as 42% compared to the pulses not inoculated. Results from this study are novel and provide the baseline for model-related studies on water use and nutrient uptake by root systems of oilseed and pulse crops in semiarid environments.

We use computational homology to characterize the geometry of complicated time-dependent patterns. Homology provides very basic topological (geometrical) information about the patterns, such as the number of components (pieces) and the number of holes. For 3-dimensional patterns it also provides the number of voids. We apply these techniques to patterns generated by experiments on spiral defect chaos, as well as to numerically simulated patterns in the Cahn-Hilliard theory of phase separation and on spiral wave patterns in excitable media. These techniques allow us to distinguish patterns at different parameter values, to detect complicated dynamics through the computation of positive Lyapunov exponents and entropies, to compare experimental data with numerical simulations, to quantify boundary effects on finite size domains, among other things.

The objective of this thesis is to explore the relationship between street patterns and floodplains. Although some researchers have written about the relationship between land use and floodplains in The Woodlands, few have discussed how the city form was designed around the hydrological system. This thesis will focus on one aspect of the city form, the street pattern, to determine the effectiveness of street designs' response to floodplains. Unlike the grid-like pattern advocated by the New Urbanists, street patterns in The Woodlands are loops and cul-de-sacs -- a typical suburban pattern at the time it was developed; however, street patterns adapt to the boundaries of floodplains and protect them very well. Using a GIS tool to overlay 100-year floodplains on the street layer, it is clear to see that there are low percentages of streets in the 100-year floodplains. Thus, The Woodlands employed nonstructural techniques to mitigate flood hazard, which minimize the development in floodplains. Flood control in The Woodlands is much better than other places in the Houston area. From flood control and the protection of the natural environment standpoints, the nonstructural techniques are advocated more than structural techniques for floodplains in the development management. Therefore, the design of street patterns in an area is determined by both the aim of convenient transportation and the aim of hazard mitigation.

Thèse doctorat : Informatique : Rennes 1 : 2006. / Bibliogr. p. 201-210.

Abstract When avibratingstructureisrotatedwithrespecttoinertialspace,thevibratingpatternrotatesatarateproportionalto the inertialrateofrotation.Bryanfirstobservedthiseffectin1890.Theeffect,calledBryan’seffectinthesequel,has numerous navigationalapplicationsandcouldbeusefulinunderstandingthedynamicsofpulsatingstarsandearthquake series inastrophysicsandseismology.Bryan’sfactor(thecoefficientofproportionalitybetweentheinertialandvibrating pattern rotationrates)dependsonthegeometryofthestructureandthevibrationmodenumber.The‘‘gyroscopiceffects’’ of ahollowisotropicsolidspherefilledwithaninviscidacousticmediumareconsideredhere,butthetheoryisreadily adapted toahollowisotropicsolidcylinderfilledwithaninviscidacousticmedium.Alineartheoryisdevelopedassuming, among othermildconditions,thattherotationrateisconstantandmuchsmallerthanthelowesteigenfrequencyofthe vibrating system.Thuscentrifugalforcesareconsideredtobenegligible.Beforecalculatingsolutionsforthedisplacement of aparticleintheisotropic,spherical,distributedbody,Bryan’sfactorisinterpretedusingacomplexfunction.Hereitis demonstrated thatneitherBryan’seffectnorBryan’sfactorisinfluencedbyincludinglight,isotropic,viscousdampingin the mathematicalmodel.Hencedampingisneglectedinthesequel.Twoscenariosarethenidentified.Firstly,wemay assume thattheacousticmediumiscompletelyinvolvedintherotation(thespheroidalmode).Secondly,wemayassume that theacousticmediumremainsstaticwithrespecttotheinertialreferenceframe(thetorsionalmode).Weinvestigatethe spheroidal modeusinganumericalexperimentthatcomparestherotationalangularrateofasphere(filledwithaninviscid acoustic medium)withthoseofitsvibratingpatternsatbothhighandlowvibrationfrequency.

The purpose of this article is twofold, first to promote the use of patterns in the analysis phase of the software life-cycle by proposing an outline template for analysis patterns that strongly supports the whole analysis process from the requirements analysis to the analysis model and further on to its transformation into a flexible design. Second we present, as an example, a family of analysis patterns that deal with a series of pressing problems in cooperative work, collaborative information filtering and sharing, and knowledge management. We present the step-by-step evolution of the analysis pattern virtual library with active agents starting with a simple pinboard. In this paper we propose that using patterns in the analysis phase has the potential to reducing development time by introducing reuse already at the analysis stage and by improving the interface between analysis and design phase. To quantify our proposal we present results from the Virtual University project of the Vienna University of Economics and Business Administration, where the analysis patterns developed in this paper were used to implement several information systems. (author's abstract) / Series: Working Papers on Information Systems, Information Business and Operations

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