985 resultados para pre-filtration vertical columns


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Screening new and existing breeding germplasm and cultivars for grain defect tolerance for breeding programs, evaluate new methods and technologies to screen more effectively for the barley grains defects - pre-harvest sprouting, blackpoint, kernel discolouration, and investigate genetic mechanisms involved in controlling barley grain defect tolerance.

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The aims of the project are to 1) identify closely linked molecular markers to resistance genes and validate them in Australian wheat and barley backgrounds, and 2) introgress RWA resistance into Australian wheat and barley backgrounds.

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The kidney filtration barrier consists of fenestrated endothelial cell layer, glomerular basement membrane and slit diaphragm (SD), the specialized junction between glomerular viscelar epithelial cells (podocytes). Podocyte injury is associated with the development of proteinuria, and if not reversed the injury will lead to permanent deterioration of the glomerular filter. The early events are characterized by disruption of the integrity of the SD, but the molecular pathways involved are not fully understood. Congenital nephrotic syndrome of the Finnish type (CNF) is caused by mutations in NPHS1, the gene encoding the SD protein nephrin. Lack of nephrin results in loss of the SD and massive proteinuria beginning before birth. Furthermore, nephrin expression is decreased in acquired human kidney diseases including diabetic nephropathy. This highlights the importance of nephrin and consequently SD in regulating the kidney filtration function. However, the precise molecular mechanism of how nephrin is involved in the formation of the SD is unknown. This thesis work aimed at clarifying the role of nephrin and its interaction partners in the formation of the SD. The purpose was to identify novel proteins that associate with nephrin in order to define the essential molecular complex required for the establishment of the SD. The aim was also to decipher the role of novel nephrin interacting proteins in podocytes. Nephrin binds to nephrin-like proteins Neph1 and Neph2, and to adherens junction protein P-cadherin. These interactions have been suggested to play a role in the formation of the SD. In this thesis work, we identified densin as a novel interaction partner for nephrin. Densin was localized to the SD and it was shown to bind to adherens junction protein beta-catenin. Furthermore, densin was shown to behave in a similar fashion as adherens junction proteins in cell-cell contacts. These results indicate that densin may play a role in cell adhesion and, therefore, may contribute to the formation of the SD together with nephrin and adherens junction proteins. Nephrin was also shown to bind to Neph3, which has been previously localized to the SD. Neph3 and Neph1 were shown to induce cell adhesion alone, whereas nephrin needed to trans-interact with Neph1 or Neph3 from the opposite cell surface in order to make cell-cell contacts. This was associated with the decreased tyrosine phosphorylation of nephrin. These data extend the current knowledge of the molecular composition of the nephrin protein complex at the SD and also provide novel insights of how the SD may be formed. This thesis work also showed that densin was up-regulated in the podocytes of CNF patients. Neph3 was up-regulated in nephrin deficient mouse kidneys, which share similar podocyte alterations and lack of the SD as observed in CNF patients podocytes. These data suggest that densin and Neph3 may have a role in the formation of morphological alterations in podocytes detected in CNF patients. Furthermore, this thesis work showed that deletion of beta-catenin specifically from adult mouse podocytes protected the mice from the development of adriamycin-induced podocyte injury and proteinuria compared to wild-type mice. These results show that beta-catenin play a role in the adriamycin induced podocyte injury. Podocyte injury is a hallmark in many kidney diseases and the changes observed in the podocytes of CNF patient share characteristics with injured podocytes observed in chronic kidney diseases. Therefore, the results obtained in this thesis work suggest that densin, Neph3 and beta-catenin participate in the molecular pathways which result in morphological alterations commonly detected in injured podocytes in kidney diseases.

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The effectiveness of pre-plant dips of crowns in potassium phosphonate and phosphorous acid was investigated in a systematic manner to develop an effective strategy for the control of root and heart rot diseases caused by Phytophthora cinnamomi in the pineapple hybrids 'MD2' and '73-50' and cultivar Smooth Cayenne. Our results clearly indicate that a high volume spray at planting was much less effective when compared to a pre-plant dip. 'Smooth Cayenne' was found to be more resistant to heart rot than 'MD2' and '73-50', and 'Smooth Cayenne' to be more responsive to treatment with potassium phosphonate. Based on cumulative heart rot incidence over time 'MD2' was more susceptible to heart rot than '73-50' and was more responsive to an application of phosphorous acid. The highest levels of phosphonate in roots were reached one month after planting and levels declined during the next two months. Pre-plant dipping of crowns prior to planting is highly effective to control root and heart rot in the first few months but is not sufficient to maintain health of the mother plant root system up until plant crop harvest when weather conditions continue to favour infection.

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Data on free convection heat transfer to water and mercury are collected using a test rig in vertical annuli of three radii ratios, the walls of which are maintained at uniform temperatures. A theoretical analysis of the boundary layer equations has been attempted using local similarity transformation and double boundary layer approach. Correlations derived from the present theoretical analysis are compared with the analysis and the experimental data available in literature for non-metallic fluids and also with the present experimental data on water and mercury. Generalised correlations are set up for expressing the ratio of heat transferred by convection to the heat transferred by pure conduction and Nusselt's number, in terms of Grashof, Rayleigh and Prandtl numbers, based on the theoretical analysis and the present data on mercury and water. The present generalised correlations agree with the reported and present data for non-metallic fluids and liquid metals with an average deviation of 9% and maximum deviation of ± 13.7%.

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The classical problem of surface water-wave scattering by two identical thin vertical barriers submerged in deep water and extending infinitely downwards from the same depth below the mean free surface, is reinvestigated here by an approach leading to the problem of solving a system of Abel integral equations. The reflection and transmission coefficients are obtained in terms of computable integrals. Known results for a single barrier are recovered as a limiting case as the separation distance between the two barriers tends to zero. The coefficients are depicted graphically in a number of figures which are identical with the corresponding figures given by Jarvis (J Inst Math Appl 7:207-215, 1971) who employed a completely different approach involving a Schwarz-Christoffel transformation of complex-variable theory to solve the problem.

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Coal seam gas (CSG) is a growing industry in Queensland and represents a potential major employer and deliverer of financial prosperity for years to come. CSG is a natural gas composed primarily of methane and is found trapped underground in coal beds. During the gas extraction process, significant volumes of associated water are also produced. This associated water could be a valuable resource, however, the associated water comprises of various salt constituents that make it problematic for beneficial use. Consequently, there is a need to implement various water treatment strategies to purify the associated water to comply with Queensland’s strict guidelines and to mitigate environmental risks. The resultant brine is also of importance as ultimately it also has to be dealt with in an economical manner. In some ways it can be considered that the CSG industry does not face a water problem, as this has inherent value to society, but rather has a “salt issue” to solve. This study analyzes the options involved in both the water treatment and salt recovery processes. A brief overview of the constituents present in Queensland CS water is made to illustrate the challenges involved and a range of treatment technologies discussed. Water treatment technologies examined include clarification (ballasted flocculation, dissolved air flotation, electrocoagulation), membrane filtration (ultrafiltration), ion exchange softening and desalination (ion exchange, reverse osmosis desalination and capacitance deionization). In terms of brine management we highlighted reinjection, brine concentration ponds, membrane techniques (membrane distillation, forward osmosis), thermal methods, electrodialysis, electrodialysis reversal, bipolar membrane electrodialysis, wind assisted intensive evaporation, membrane crystallization, eutectic freeze crystallization and vapor compression. As an entirety this investigation is designed to be an important tool in developing CS water treatment management strategies for effective management in Queensland and worldwide.

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In this study, a bench scale forward osmosis (FO) process was operated using two commonly available FO membranes in different orientations in order to examine the removal of foulants in the coal seam gas (CSG) associated water, the water flux and fouling behaviours of the process were also investigated. After 48 h of fouling simulation experiment, the water flux declined by approximately 55 and 35% of its initial level in the TFC-PRO and CTA-PRO modes (support layer facing the feed), respectively, while the flux decline in the TFC-FO and CTA-FO modes (active layer facing the feed) was insignificant. The flux decline in PRO modes was caused by the compounding effects of internal concentration polarisation and membrane fouling. However, the declined flux was completely recovered to its initial level following the hydraulic cleaning using deionised water. Dissolved organic carbon (DOC), adenosine tri-phosphate (ATP) and major inorganic scalants (Ca, Mg and silica) in the CSG feed were effectively removed by using the FO process. The results of this study suggest that the FO process shows promising potential to be employed as an effective pre-treatment for membrane purification of CSG associated water.

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Corymbia species from different sections hybridize readily, with some of increasing economic importance to plantation forestry. This study explores the locations of reproductive barriers between interspecific Corymbia hybrids and investigates the reproductive success of a wide taxonomic range of C. torelliana hybrid crosses. Pollen, pistil and embryo development were investigated for four C. torelliana crosses (C. torelliana, C. citriodora subsp. citriodora, C. tessellaris and C. intermedia) using fluorescent and standard microscopy to identify the locations of interspecific reproductive isolating barriers. Corymbia torelliana was also crossed with 16 taxa, representing six of the seven Corymbia sections, both Corymbia subgenera and one species each from the related genera, Angophora and Eucalyptus. All crosses were assessed for capsule and seed yields. Interspecific C. torelliana hybridization was controlled by pre-zygotic reproductive isolating barriers inhibiting pollen adhesion to the stigma, pollen germination, pollen tube growth in the style and pollen tube penetration of the micropyle. Corymbia torelliana (subgenus Blakella, sect. Torellianae) was successfully hybridized with Corymbia species from subgenus Blakella, particularly C. citriodora subsp. citriodora, C. citriodora subsp. variegata, C. henryi (sect. Maculatae) and C. tessellaris (sect. Abbreviatae), and subgenus Corymbia, particularly C. clarksoniana and C. erythrophloia (sect. Septentrionales). Attempted intergeneric hybrids between C. torelliana and either Angophora floribunda or Eucalyptus pellita were unsuccessful. Corymbia hybrids were formed between species from different sections and subgenera, but not with species from the related genera Angophora or Eucalyptus. Reproductive isolation between the interspecific Corymbia hybrid crosses was controlled by early- and late-acting pre-zygotic isolating barriers, with reproductive success generally decreasing with increasing taxonomic distance between parent species. These findings support the monophyly of Corymbia and the close relationships of infrageneric clades. The hybridizing propensity of Corymbia species provides opportunities for breeding but suggests risks of environmental gene flow. © The Author 2012. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

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This study explored pre-service secondary science teachers’ perceptions of classroom emotional climate in the context of the Bhutanese macro-social policy of Gross National Happiness. Drawing upon sociological perspectives of human emotions and using Interaction Ritual Theory this study investigated how pre-service science teachers may be supported in their professional development. It was a multi-method study involving video and audio recordings of teaching episodes supported by interviews and the researcher’s diary. Students also registered their perceptions of the emotional climate of their classroom at 3-minute intervals using audience response technology. In this way, emotional events were identified for video analysis. The findings of this study highlighted that the activities pre-service teachers engaged in matter to them. Positive emotional climate was identified in activities involving students’ presentations using video clips and models, coteaching, and interactive whole class discussions. Decreases in emotional climate were identified during formal lectures and when unprepared presenters led presentations. Emotions such as frustration and disappointment characterized classes with negative emotional climate. The enabling conditions to sustain a positive emotional climate are identified. Implications for sustaining macro-social policy about Gross National Happiness are considered in light of the climate that develops in science teacher education classes.

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The sorghum core breeding program has had a long history of contributing to the productivity of the industry particularly through its contributions to traits such as midge resistance and stay-green and also through its contribution to grain yield per se. 100% of the commercial hybrids on the market have some genetics from the program. In this presentation we will provide an overview of what the program does, how the benefits of its research get to industry and the future directions of the program. With respect to the latter we will focus on opportunities to increase grain yield.

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Effects of large deformation and inelasticity are considered in formulating the behavior of columns of variable cross section subjected to an axial compressive load. Simple, approximate methods are used to obtain numerical results. The combined effect of the nonlinearities is shown to be of a hardening type for small column deflections