Lignin is a key component of plant secondary cell walls, providing strength to the plant and allowing water transport. Lignin is a polymer of monolignols that are synthesized in the cell and transported into the cellulose rich cell wall. The primary goal of this thesis is to understand the mechanism(s) of monolignol deposition during xylogenesis. The currently accepted theory is that monolignols are exported by Golgi-mediated vesicle delivery to the secondary cell wall. When this theory was re-examined using cryofixed developing pine, quantitative autoradiography showed that monolignols did not accumulate in Golgi but were rapidly translocated from cytosol to cell wall. This suggests alternative mechanisms, such as membrane transporters, work in monolignol export. ATP binding cassette (ABC) transporters were chosen because they transport other secondary metabolites and some ABC transporter encoding genes are highly expressed in lignifying cells. Four candidate ABC transporters were selected in Arabidopsis (ABCB11, ABCB14, ABCB15 from the ABCB/MDR subfamily and ABCG33 from the ABCG/PDR subfamily) and shown to have overlapping, high vasculature expression patterns. Mutants with T-DNA insertions in single ABC transporter genes had no change in lignification of inflorescence stems. However, a reduced polar auxin transport phenotype was detected in mutants of ABCB11, ABCB14 and ABCB15. An additional approach was the use of inhibitors of ABC transporters. A new assay, which was developed to quantify lignification in primary xylem of Arabidopsis roots, demonstrated that ABC inhibitors did not change lignin deposition. Monolignols are exported and polymerized in the polysaccharide matrix of the cell wall, which includes hemicelluloses that may organize monolignols during polymerization. Since diverse lignified cell types are enriched in either G- or S-lignin, I hypothesized that this pattern could reflect different hemicellulose distributions, which was examined using antibody labeling of xylans or mannans in hybrid poplar xylem. While xylans were generally distributed in all secondary cell walls, mannans were enriched in fibers but not in the ray and vessel walls. In summary, during secondary cell wall deposition, monolignols are exported by unknown transporter(s) rather than Golgi vesicles. In developing poplar wood, the monolignols are deposited into diverse hemicellulose domains in different cell types.

No description available.

No description available.

<p>The aim of this research paper is to examine the legal framework for the recovery of corruptly-acquired assets, with particular emphasis on the Nigerian situation. Its primary focus is a detailed examination of the legal mechanisms for the recovery of such assets in the context of international asset recovery. Despite the success of the Nigerian government in recovering the Abacha loot,8 siphoning off of public funds by public office holders continues, and charges of fraud persist against top bank executives alleged to have converted depositors&rsquo / funds fraudulently. The prevailing criminal or conviction-based forfeiture mechanism in Nigeria appears inadequate to deal effectively with these situations. The need to enhance capacity through the adoption of civil or non-conviction based forfeiture laws therefore becomes imperative.</p>

Tests were conducted for 71 pesticides in weekly bulk (wet + dry) deposition samples collected from May 25 to September 21 over two years at two sites in the City of Winnipeg, Canada. Twenty-one pesticides and their metabolites were detected in this study and 99% of samples collected contained mixtures of two or more pesticides. Malathion and glyphosate were the largest contributors to bulk deposition in 2010 and 2011, respectively. A second study examined the mineralization of 2,4-D and 17β-estradiol using a novel in-field soil microcosm study and a series of laboratory experiments under different temperature incubations. Results indicated that temperature fluctuations do not greatly affect the amount or rate of mineralization relative to the traditionally constant laboratory incubations of 20°C; however long-term freezing of soil reduced potential mineralization over time. This research advances scientific knowledge of agri-chemical fate and provides data for strengthening current environmental policy analysis in Canada.

Tests were conducted for 71 pesticides in weekly bulk (wet + dry) deposition samples collected from May 25 to September 21 over two years at two sites in the City of Winnipeg, Canada. Twenty-one pesticides and their metabolites were detected in this study and 99% of samples collected contained mixtures of two or more pesticides. Malathion and glyphosate were the largest contributors to bulk deposition in 2010 and 2011, respectively. A second study examined the mineralization of 2,4-D and 17β-estradiol using a novel in-field soil microcosm study and a series of laboratory experiments under different temperature incubations. Results indicated that temperature fluctuations do not greatly affect the amount or rate of mineralization relative to the traditionally constant laboratory incubations of 20°C; however long-term freezing of soil reduced potential mineralization over time. This research advances scientific knowledge of agri-chemical fate and provides data for strengthening current environmental policy analysis in Canada.

Tyrimų tikslas. Identifikuoti naujus žieminių kviečių genus, aktyvuojamus žemose temperatūrose bei atlikti šių genų sekų ir genetinės raiškos analizę. Tyrimų uždaviniai: 1. Ištirti žieminių kviečių genotipų tolerantiškumą žemoms neigiamoms temperatūroms natūraliomis ir dirbtinėmis sąlygomis. 2. Nustatyti skirtingose grūdinimosi stadijose diferenciškai ekspresuojamus genus (kDNR-AFLP analizė) ir atlikti DNR sekų analizę. 3. Optimizuoti mutagenezės metodą ir sukurti dviejų perspektyvių žieminių kviečių linijų mutagenines populiacijas. 4. Nustatyti skirtingu intensyvumu ekspresuojamų genų mutacijas HRM metodu, įvertinti nustatytų mutacijų įtaką genų ekspresijai grūdinimosi metu ir žemų neigiamų temperatūrų tolerancijai. / Research objective: To identify new genes of winter wheat induced at low temperatures, to perform sequence analysis of these genes and to quantify their expression. Experimental tasks: 1. To evaluate freezing tolerance of various winter wheat genotypes under field and controlled conditions. 2. To identify differentially expressed genes at subsequent time points of cold acclimation and to perform analysis of their DNA sequences. 3. To optimize mutagenesis method and to create Targeting Induced Local Lesions in Genomes (TILLING) population of two winter wheat lines. 4. To identify mutations in differentially expressed genes by High Resolution melting (HRM) method, to estimate the impact of mutations on the gene expression during cold acclimation and tolerance to freezing.

Research objective: To identify new genes of winter wheat induced at low temperatures, to perform sequence analysis of these genes and to quantify their expression. Experimental tasks: 1. To evaluate freezing tolerance of various winter wheat genotypes under field and controlled conditions. 2. To identify differentially expressed genes at subsequent time points of cold acclimation and to perform analysis of their DNA sequences. 3. To optimize mutagenesis method and to create Targeting Induced Local Lesions in Genomes (TILLING) population of two winter wheat lines. 4. To identify mutations in differentially expressed genes by High Resolution melting (HRM) method, to estimate the impact of mutations on the gene expression during cold acclimation and tolerance to freezing. / Tyrimų tikslas. Identifikuoti naujus žieminių kviečių genus, aktyvuojamus žemose temperatūrose bei atlikti šių genų sekų ir genetinės raiškos analizę. Tyrimų uždaviniai: 1. Ištirti žieminių kviečių genotipų tolerantiškumą žemoms neigiamoms temperatūroms natūraliomis ir dirbtinėmis sąlygomis. 2. Nustatyti skirtingose grūdinimosi stadijose diferenciškai ekspresuojamus genus (kDNR-AFLP analizė) ir atlikti DNR sekų analizę. 3. Optimizuoti mutagenezės metodą ir sukurti dviejų perspektyvių žieminių kviečių linijų mutagenines populiacijas. 4. Nustatyti skirtingu intensyvumu ekspresuojamų genų mutacijas HRM metodu, įvertinti nustatytų mutacijų įtaką genų ekspresijai grūdinimosi metu ir žemų neigiamų temperatūrų tolerancijai.

Turkey with pale, soft, exudative (PSE)-like condition is one of the growing concerns in the poultry industry as it affects meat quality due to low ultimate pH at 24 h post mortem (pH24). Hence, there is a need for better utilization of PSE-like meat for the preparation of further processed products. In the first two studies, the biochemical, functional, rheological, and textural properties of proteins in turkey breast meat with different pH24 in fresh and frozen conditions were investigated. These studies revealed that low and normal pH meat had similar properties indicating similar extent of protein denaturation, except for lower water holding capacity (WHC) in low pH meat. High pH meat had similar or better functional properties than normal pH meat. In the third study, improvements in WHC, protein solubility, and gel forming ability of low pH meat was achieved by the application of high pressure processing (HPP). / Food Science and Technology

This thesis reports on a comprehensive experimental study of the collective dynamics of colloidal hard sphere suspensions. The main quantity measured is the coherent Intermediate Scattering Function (ISF) using a range of techniques based on Dynamic Light Scattering (DLS). The collective dynamics are measured as a function of scattering vector for volume fractions spanning from dilute samples, through the fluid phase and the metastable region, up until deep in the glass region. This work describes two major explorations: (i) the effect of volume of fraction on the q-dependency of the collective dynamics; and (ii) a study of the ageing processes in colloidal glasses. The present work is unique in the application of several advanced experimental techniques, and in the level of averaging that has been carried out, enabling a more sophisticated analysis than has previously been possible. This includes the characterization of non-Fickian processes and the determinatio n of the current-current correlation function (CCCF) in the metastable fluid, and the quantitative characterization of the ageing process in the hard sphere glass. In addition, by combining aspects of the coherent and incoherent ISFs, this work also allows the expression of the collective dynamics in terms of the single particle displacement. The results show a dynamical change at the freezing point (f), which exposes the incapacity of the system to dissipate thermal energy via diffusing momentum currents, i.e. viscous flow. The structural impediments responsible for this, associated with dynamical heterogeneities, begin at the structure factor peak, and spread to other spatial modes as the volume fraction increases. Above the glass transition (g), structural relaxation becomes arrested at all spatial modes probed, i.e. flow is arrested. It is found that, following the quench, samples above the glass volume fraction approach some final