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I evaluated the effectiveness of plant roots to increase infiltration rates within stormwater bioretention facilities (SBFs), roadside planter compartments that filter stormwater. SBFs attenuate harmful effects of stormwater by reducing peak flow and retaining pollutants, with increased infiltration that improves both these functions. Researchers have shown that roots can increase infiltration within greenhouse, lab, field, and test SBF settings. However, no researchers have yet measured either the extent to which different root characteristics can increase infiltration or the variation in root characteristics and their effect on infiltration rates among plant assemblages within currently functioning SBFs. To determine if root-enhanced infiltration was occurring within SBFs, I hypothesized 1) there is a relationship between root characteristics and infiltration during late spring, and 2) seasonal root growth increases infiltration rates. Within Portland, OR, I measured infiltration rate from January 2014 to February 2015 and root characteristics from January-February (J-F) and May-June (M-J) 2014 in ten SBFs with "Elk Blue" rush (Juncus patens) and 1 or 2 trees of less than 8.4 cm stem diameter. During M-J, four root characteristics showed a positive relationship with infiltration rate, and two root characteristics showed a strong positive relationship with infiltration rate within the topsoil. Also, a relationship was shown between the increase (J-F to M-J 2014) in three root characteristics and the increase in infiltration rate. To determine if root morphology and infiltration rates differed among SBFs with two different dominant vegetation taxa (small and large root biomass), I hypothesized 3) Juncus patens and tree dominant assemblage (greater root biomass) exhibits greater infiltration compared to the Carex dominant assemblage, 4) the increase in infiltration rate and root characteristics from J-F to M-J is greater in the Juncus compared to the Carex assemblage, and 5) root surface area density (RSAD) within Juncus SBFs shows a positive relationship with infiltration rate in late spring. I measured infiltration rate from January 2014 to February 2015 and root characteristics from January-February (J-F) and May-June (M-J) 2014 among five large-root (Juncus and tree) and five small-root biomass (Carex sp) SBFs. Juncus SBFs showed greater values for three root characteristics during J-F and five root characteristics during M-J 2014 compared to Carex SBFs. Also, Juncus SBFs showed an increase from J-F to M-J 2014 for five root characteristics while Carex SBFs showed no root increase. Juncus SBFs showed a relationship with four root characteristics and Carex SBFs a showed relationship with one root characteristic and infiltration rate. This work strongly suggests plant roots increase infiltration, and thus the primary functions of SBFs. Different root characteristics appear to increase infiltration rate at different depths. Data also show larger-root biomass plants increase infiltration rate to a greater degree than smaller-root biomass plants. I recommend considering several site and facility characteristics when determining the potential for root-enhanced infiltration. When selecting plant species to enhance infiltration, I recommend using several criteria, determining root characteristic values at certain depths, considering installation approaches, and accounting for regional climate changes.

Forest soils store as much carbon (C) as the vegetation that grows on them, and the carbon in soil is more stable than the C in biomass. Quaking aspen (Populus tremuloides Michx.) is the most widespread tree species in North America, and aspen forests in the Western US have been found to store more soil organic carbon (SOC) in the mineral soil than nearby conifers. Fire exclusion and grazing often promote the succession of aspen to conifer dominated forests due to their effect on aspen regeneration. So far the factors driving the differential SOC accumulation, and the effects of the vegetation shift on SOC pools, are not well understood. In this dissertation I aimed to evaluate how various forest vegetation characteristics – tree type, detritus fluxes, detritus chemistry – affect SOC pools and stability from a global to a molecular level using two contrasting forest types – aspen and conifer. A meta-analysis showed that, while conifer forests worldwide had higher C pools in the forest floor, this difference did not translate into the mineral soil, suggesting that the mechanisms that control SOC storage differ between both soil compartments. Above- and belowground detritus input fluxes were similar between aspen and conifer forests, and did not explain the higher SOC pools under aspen. A sorption study revealed that the more labile aspen foliage dissolved organic carbon (DOC) was more effectively retained in soil than aspen root, and conifer substrate DOC. Furthermore, soils that contained aspen SOC retained new DOC better than soils with conifer SOC, irrespective of the source of the DOC. Finally, foliage and root specific compounds that were identified for aspen and subalpine fir provide a base for future studies aiming to identify the source of SOC under both overstory types. Overall, the results of the dissertation suggest that substrate chemistry more than detritus fluxes drive the differences between SOC pools under aspen and conifer forests in Utah. This finding indicates that the link between C input amounts and SOC pools is not as direct as currently assumed in most SOC models. Furthermore, a tree species effect on SOC as distinct as aspen vs conifer is not common between all hardwood and conifer comparisons worldwide, thus suggesting that the effect of vegetation can be overridden by other factors.

Comment aborder la musique de Maurice Ohana et quel sens donner à l’usage qu’il fait de la guitare dans son œuvre ? Dans cette recherche, nous tenterons de cerner en quoi la guitare tient une place si particulière et si essentielle au regard de l’ensemble de son œuvre. Elle est, en effet, porteuse de tout un univers culturel et symbolique et contribue à nourrir l’imaginaire poétique du créateur intemporel qu’est Maurice Ohana. Cet univers poétique et atavique irisé d’une arborescence d’influences est, chez le compositeur, tout à la fois une source d’inspiration et d’innovation. La guitare à dix cordes qu’il a introduite dans ses deux cycles : Si le jour paraît… et Cadran lunaire, lui permet d’opérer sur la matière sonore, un travail de création qui donne lieu à une œuvre originale dont la compréhension nécessite l’exploration d’un héritage culturel fortement imprégné du cante jondo et de la culture andalouse. Entre tradition et innovation, oralité et écriture, l’œuvre pour guitare entretient avec la matière sonore, une relation qui donne sens au processus de compréhension de l’œuvre de Maurice Ohana. / How to approach the music of Maurice Ohana and what sense should we give to the use he makes of the guitar in his work? In this research, I will try to understand how the guitar holds such a special and essential place in his work as a whole. In fact, it carries a whole cultural and symbolic universe and contributes to nourishing the poetic imagination of the timeless creator Maurice Ohana. This poetic and atavistic world of a tree of influences is, in the composer's mind, both a source of inspiration and innovation. The ten-string guitar that he introduced in his two cycles — Si le jour paraît… and Cadran lunaire — allows him to operate on the sound material (“matière sonore”), a creative work that gives rise to an original work whose understanding requires the exploration of a cultural heritage strongly imbued with cante jondo and Andalusian culture. Between tradition and innovation, orality and writing, the work for guitar has a relationship with the sound material (“matière sonore”) that gives meaning to the process of understanding of Maurice Ohana’s work.

Bibliography: leaves 172-197.

Bibliography: leaves 172-197. / xvii, 197 leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil and Water, 2002?

This thesis consists of four papers and the main theme present is dependence, through time as in serial correlation, and across individuals, as in random effects. The individual papers may be grouped in many different ways. As is, the first two are concerned with autoregressive dynamics in a single time series and then a panel context, while the subject of the final two papers is parametric covariance modeling. Though set in a panel context the results in the latter are generally applicable. The approach taken is Bayesian. This choice is prompted by the coherent framework that the Bayesian principle offers for quantifying uncertainty and subsequently making inference in the presence of it. Recent advances in numerical methods have also made the Bayesian choice simpler. In the first paper an existing model to conduct inference directly on the roots of the autoregressive polynomial is extended to include seasonal components and to allow for a polynomial trend of arbitrary degree. The resulting highly flexible model robustifies against misspecification by implicitly averaging over different lag lengths, number of unit roots and specifications for the deterministic trend. An application to the Swedish real GDP illustrates the rich set of information about the dynamics of a time series that can be extracted using this modeling framework. The second paper offers an extension to a panel of time series. Limiting the scope, but at the same time simplifying matters considerably, the mean model is dropped restricting the applicability to non-trending panels. The main motivation of the extension is the construction of a flexible panel unit root test. The proposed approach circumvents the classical confusing problem of stating a relevant null hypothesis. It offers the possibility of more distinct inference with respect to unit root composition in the collection of time series. It also addresses the two important issues of model uncertainty and cross-section correlation. The model is illustrated using a panel of real exchange rates to investigate the purchasing power parity hypothesis. Many interesting panel models imply a structure on the covariance matrix in terms of a small number of parameters. In the third paper, exploiting this structure it is demonstrated how common panel data models lend themselves to direct sampling of the variance parameters. Not necessarily always practical, the implementation can be described by a simple and generally applicable template. For the method to be practical, simple to program and quick to execute, it is essential that the inverse of the covariance matrix can be written as a reasonably simple function of the parameters of interest. Also preferable but in no way necessary is the availability of a computationally convenient expression for the determinant of the covariance matrix as well as a bounded support for the parameters. Using the template, the computations involved in direct sampling and effect selection are illustrated in the context of a one- and two-way random effects model respectively. Having established direct sampling as a viable alternative in the previous paper, the generic template is applied to panel models with serial correlation in the fourth paper. In the case of pure serial correlation, with no random effects present, applying the template and using a Jeffreys type prior leads to very simple computations. In the very general setting of a mixed effects model with autocorrelated errors direct sampling of all variance parameters does not appear to be possible or at least not obviously practical. One important special case is identified in the model with the random individual effects model with autocorrelation. / <p>Diss. Stockholm : Handelshögskolan i Stockholm, 2004 viii s., s. 1-9: sammanfattning, s. 10-116: 4 uppsatser</p>

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In this work we present two algebraic certificates for Budan's theorem. Budan's theorem claims the following. Let R be an ordered field, f in R[X] of degree n and a,b in R with a

Shallow foundations rested on Leda clay that are widely distributed in Eastern Canada exhibit shrinkage characteristics and are prone to differential settlements. Due to this reason, significant repairs are necessary to the foundations and basements of residential structures constructed in Leda clay deposits. Differential settlements are commonly attributed to the changes in the natural water content of soils associated with water infiltration, evaporation or plant transpiration (i.e., tree-roots-suction). Various research studies have been undertaken to estimate the possible settlements of shallow foundations associated with the water infiltration or evaporation. Several thumb rules have been proposed through research studies, providing recommendations with respect to the distance at which trees must be planted as a function of their heights at maturity such that differential settlements can be avoided. However, limited studies have been carried out to estimate or model the settlements of shallow foundations taking into account the influence of tree-roots-suction. In the present research program, a comprehensive experimental study regarding the deformation characteristics of a sandy loam soil from Ottawa due to tree-root-suction is undertaken, using specially designed equipment. The study has been undertaken using a sandy loam soil so that the testing program can be conducted in a shorter period of time. An artificial rooting system (ARS) was designed and placed in a specially designed tank at the University of Ottawa to simulate tree-roots-suction and measure soil surface settlements associated with a decrease in natural water content (or increase in soil suction) using particle image velocimetry (PIV) technique. The ARS consists of an artificial root, suction generator, matric suction and volumetric water content monitoring devices. The variation of matric suction and volumetric water content are monitored at various depths using the instrumentation of the ARS. Based on the results of the experimental studies, a methodology is proposed to model the settlement behaviour of sandy loam soils due to suction from ARS, using commercial finite element software, SEEP/W and SIGMA/W (i.e. software package of GeoStudio 2007). The study offers a reasonably good comparison between the measured surface settlements and those estimated using the finite element modelling analysis. The modelling methodology presented in this thesis is promising and may be extended for estimating the settlement behaviour associated with the tree roots suction of Leda clay deposits and to other soils.