Powdered laundry detergents are consumed in high volumes worldwide. Post use, they are directed toward water resources via wastewater treatment works or, as is the situation in many rural areas of South Africa, they enter the environment directly as a result of laundry washing activity undertaken alongside surface waters. Within wastewater treatment works, the main ingredient in powdered laundry detergents, the narcotic toxin linear alkylbenzene sulfonate (LAS), is mostly removed, rendering the waste stream a negligible risk to the aquatic biota of receiving waters. In contrast, the biological and ecological impacts of direct LAS input to the aquatic environment, as a consequence of near-stream laundry washing, are yet to be fully realised. Consequently, this thesis posed two research questions: 1) 'What are the LAS concentrations in a small rural South African river'? and 2) 'Is the in-stream biological community negatively affected at these concentrations?' The chosen study area, the community of Balfour in the Eastern Cape Province, is like many rural areas of South Africa where inadequate provision of piped water to homesteads necessitates laundry washing alongside the nearby Balfour River. The first research question was addressed in two ways: by predicting LAS concentrations in Balfour River water by assessing detergent consumption and laundry washing behaviour of residents living alongside the river; and measuring actual in- stream LAS concentrations on different days of the week and during different seasons. Results indicated that LAS concentrations were highly variable temporally and spatially. High peak concentrations of LAS occurred infrequently and were limited to the immediate vicinity of near-stream laundry washing activity with the highest measured concentration being 342 μg.L ⁻¹ and the average 21 μg.L ⁻¹ over the sampling period. The second research question was addressed by integrating the chemical evidence, determined from the first research question, with the biological evidence of stress responses measured in macroinvertebrates collected downstream of near-stream laundry washing activity on the Balfour River. Predicted and measured LAS exposure concentrations from the Balfour River were compared to a water quality guideline for LAS (304 μg.L ⁻¹), specifically derived in this thesis. Biological stress responses were measured at different levels of organisation: two sub-cellular responses (lipid peroxidation and cholinesterase activity); three measures of macroinvertebrate tolerance to water quality impairment; five measures of community composition; three measures of community richness; and a surrogate measure of ecosystem function (functional feeding groups). Weight-of-evidence methodology was utilised to assess, integrate and interpret the chemical and biological evidence, and at its conclusion, determined no effect on the in-stream biological community of the Balfour River downstream of laundry washing activity.

This master thesis studies environmental effects of a detergents' compactation project. The theoretical part describes negative environmental effects of detergents' use and foreign initiatives having successfully led to decrease of these effects. The analytical part evaluates the information campaign focused on customer behavior and detergent dosage through a market survey. Lower detergent consumption is a prerequisite of a decreased negative environmental impact. Market data showing real detergent consumption are compared to expected development. Results of the market survey and the market data analysis show that a change in consumer behavior was not sufficient; and therefore, the compactation project was not successful.

Proteolytic processing of the amyloid precursor protein (APP) may lead to the formation of the Abeta peptide, the major constituent of amyloid plaques in Alzheimer`s disease. The full-length APP is a substrate for at least 2 different (alpha and beta) proteases ("secretases"). The beta-secretase, BACE, cleaves APP in the first step of processing leading to the formation of the neurotoxic Abeta. BACE competes for APP with alpha-secretase, which cleaves APP within its Abeta sequence, thus precluding Abeta formation. It is thus important to understand how is the access of the alpha- and beta-secretase to APP regulated and how are the individual activities of these secretases modulated. Both these regulatory mechanisms, access to substrate and direct activity modulation, can be determined by the lipid composition of the membrane. Integral membrane proteins (like APP and BACE), can be viewed as solutes in a two-dimensional liquid membrane, and as such their state, and biological activity, critically depend on the physico-chemical character (fluidity, curvature, surface charge distribution, lateral domain heterogeneity etc.) of the lipid bilayer. These collective membrane properties will influence the activity of embedded membrane proteins. In addition, activity regulation may involve a direct interaction with a specific lipid (cofactor or co-structure function). Interactions of membrane proteins are furthermore affected by lateral domain organization of the membrane. Previous results had suggested that the regulation of the activity of the alpha- and beta-secretases and of their access to APP is lipid dependent, and involves lipid rafts. Using the baculovirus expression system, we have purified recombinant human full-length APP and BACE to homogeneity, and reconstituted them in large (~100nm, LUVs) and giant (10-150microm, GUVs) unilamellar vesicles. Using a soluble peptide substrate mimicking the beta-cleavage site of APP, we have examined the involvement of individual lipid species in modulating BACE activity in LUVs of various lipid compositions. We have identified 3 groups of lipids that stimulate proteolytic activity of BACE: 1.cerebrosides, 2.anionic glycerophospholipids, 3. cholesterol. Furthermore, we have co-reconstituted APP and BACE together in LUVs and demonstrated that BACE cleaves APP at the correct site, generating the beta-cleaved ectodomain identical to that from cells. We have developed an assay to quantitatively follow the beta-cleavage in proteoliposomes, and we have shown that the rate of cleavage in total brain lipid proteoliposomes is higher than in phosphatidylcholine vesicles. We have also studied partitioning of APP and BACE in GUVs between liquid ordered (lo) and liquid disordered (ld) phases. In this system, significant part of the BACE pool (about 20%) partitions into the lo phase, and its partitioning into lo phase can be further enhanced by cross-linking of membrane components. Only negligible fraction of APP can be found in the lo phase. We continue to study the behavior of co-reconstituted APP and BACE in GUVs The work presented in this thesis has yielded some interesting results and raised further questions. One of the important assignments of this project will in the next stage be the characterization of the impact of membrane domain organization on the beta-cleavage. Different domain arrangements that can be hypothesized in cell membranes can be modeled by varying the degree of phase fragmentation in proteoliposomes comprising reconstituted APP and BACE.

The physical properties of glycerophospholipids (GPLs) are not only determined by the head group (HG), but also by their fatty acid (FA) chains, which affect their distribution and function within membranes in the cell. Understanding the microheterogenity of lipid membranes on a molecular level requires qualitative and quantitative characterization of individual lipids and identification of their FA moieties. The aim of my study was to introduce the new technology of multiple precursor ion scanning (MPIS) on a QSTAR Pulsar time-of-flight mass spectrometer (QqTOF) to analyze lipids. Detailed information on fatty acid composition of individual GPL molecules could be obtained in parallel with conventional profiling of lipid classes, and this could be done by direct analysis of total lipid extracts. This method was termed Fatty Acid Scanning (FAS) and Head Group Scanning HGS, respectively. In this way the molecular GPL composition of total lipid extracts could be charted in a single analysis accurately and rapidly at a low picomole concentration level. Furthermore, combining FAS and HGS together with ion trap MS3 analysis allowed complete charting of the molecular composition of PCs, including quantification of their positional isomers, thus providing a detailed and comprehensive characterization of molecular composition of the pool of PCs. Development of the Lipid Profiler software allowed full automation and rapid processing of complex data, including identification and quantification of molecular GPLs. This approach was evaluated by preliminary applications. First, the molecular composition of PCs of total lipid extracts of MDCK cells and of human red blood cells (RBC) could accurately be charted. Significant presence of positional isomers was observed increasing the total number of individual PC species close to one hundred. Secondly, the molecular PC and SM species distribution in detergent resistant membranes (DRMs) prepared by Triton X-100 DRMs were analyzed and were found to be enriched in distinct GPLs. The distribution in PCs and SMs of Triton X-100 DRMs of RBC were compared with those of the DRMs of MDCK cells. Finally, combining the use of a 96 well plate and a robotic system demonstrated that these analyses can be automated and analyzed with high throughput. This system we termed Shotgun Lipidomics. Taken together, this mass spectrometric methodology provides rapid and detailed insight into the distribution of the molecular GPLs of membranes and membrane sub-fractions.

No description available.

No description available.

The study examined the properties of stalk and cob fibres from recombinant inbred corn lines and their parents, grown at two locations, in a polylactic acid (PLA) matrix. The objectives were to: determine fibre compositions; evaluate the effects of fibres on the functional properties of biocomposites and identify quantitative trait loci (QTLs) and gene markers for fibre performance in biocomposites. Significant Genotype*Location effects were observed. Composites had lower strength (impact, tensile, and flexural) but higher tensile/flexural modulus values than pure PLA. The latter were positively affected by cellulose and hemicellulose but negatively affected by free phenolic levels and 93 fibre QTLs and 62 composite markers were detected. This study identified fibre traits and markers for genes that may be important for the use of corn fibres in biocomposites. / Ontario BioCar Initiative Project funded by Ontario Ministry of Research and Innovation, Agriculture and Agri-Food Canada, The Natural Sciences and Engineering Research Council, The Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) and Ontario Public Sector

Grasses of the genera Brachiaria and Cynodon are some of the most important pasture introductions in Brazil. Convert HD 364 brachiariagrass, a new Brachiaria hybrid, was released as an option for a broad range of environmental conditions, high nutritive value and forage production. Forage-based livestock systems are complex and interactions among animals, plants, and the environment exist at several levels of complexity, which can be evaluated using computer modeling. Herbage accumulation, crude protein (CP), neutral detergent fiber (NDF), in vitro organic matter digestibility (IVOMD), plant-part composition, leaf photosynthesis, leaf area index (LAI), and light interception (LI) were evaluated as affected by two harvest frequency (28 and 42-days), irrigated and rainfed in a clipping study from April 2011 to April 2013, contrasting Convert HD 364® brachiariagrass (Brachiaria hybrid CIAT 36061), Marandu palisadegrass {Brachiaria brizantha (Hochst. ex A. Rich.) R. D. Webster [syn. Urochloa brizantha (A. Rich.) Stapf]; CIAT 6297}, and Tifton 85 bermudagrass (Cynodon spp.). The experimental design for both the irrigated and the rainfed trials was a randomized complete block with four replications. Convert HD 364 had similar or higher annual herbage accumulation, seasonal yield and herbage accumulation rate than Marandu and Tifton 85, (15% more herbage accumulation than Marandu and 12% more than Tifton 85 when irrigated and when harvested at shorter regrowth intervals). Convert HD 364 had good seasonal distribution of total annual herbage produced and accumulates about 30% of the total herbage mass during the cool season in Piracicaba, similar to Marandu. Tifton 85 produced around 20% of its average annual yield during dry season. Tifton 85 forage had higher CP concentration than the other two grasses when harvested at shorter intervals and when irrigated. The NDF concentration in Convert HD 364 was lower than in the other grasses regardless of irrigation treatment, harvest frequency, and season of the year, resulting in high IVOMD (more than 650 g kg-1), similar to that of Marandu. Regard to CROPGRO calibration, in general the model performance was good for the three grasses. Leaf and stem weight simulations were improved, due to increase partitioning to stem for low harvest frequencies. The LAI and LI were well performed by the model, showing increase for lower harvest frequency, with exception to Tifton 85. Under rainfed conditions, the simulations using the Penman-Monteith-FAO 56 method gave more realistic water stress responses than using the Priestley and Taylor method. Calibration results suggest that the CROPGRO - Perennial Forage Model can be used to adequately simulate growth of Marandu, Convert HD 364, and Tifton 85 under irrigated and rainfed conditions, being able to simulate different harvest frequency managements. / As gramíneas do gênero Brachiaria e Cynodon são algumas das pastagens cultivadas introduzidas no Brasil de maior importância. Convert HD 364, um novo híbrido de Brachiaria, foi lançado como uma opção para uso numa ampla gama de condições ambientais, com alto valor nutritivo e produção de forragem. Sistemas pecuários em pastagens são complexos e as interações entre os animais, as plantas e o meio ambiente existem em vários níveis de complexidade, que podem ser avaliados utilizando modelagem computacional. Acúmulo de forragem, proteína bruta (PB), fibra em detergente neutro (FDN), digestibilidade in vitro da matéria orgânica (DIVMO), a composição morfológica da planta, fotossíntese foliar, índice de área foliar (IAF) e interceptação luminosa (IL) foram avaliados em resposta à duas frequências de colheita (28 e 42 dias), irrigada e não irrigada, em um estudo com parcelas colhidas mecanicamente a partir de abril de 2011 até abril de 2013, contrastando os capins Convert HD 364® (Brachiaria híbrida CIAT 36061), Marandu {Brachiaria brizantha (Hochst. ex A. Rich.) RD Webster [syn. Urochloa brizantha (A. Rich.) Stapf]; CIAT 6297} e Tifton 85 (Cynodon spp.). O delineamento experimental utilizado tanto para o irrigado quanto para o não irrigado foi de blocos casualizados, com quatro repetições. Convert HD 364 teve acúmulo de forragem anual, produção sazonal de forragem e taxa de acúmulo de forragem semelhante ou superior ao Marandu e Tifton 85, (acúmulo de forragem 15% maior do que Marandu e 12% maior do que o Tifton 85, quando irrigado e colhido em intervalos de rebrotação mais curtos). Convert HD 364 teve boa distribuição sazonal de forragem total do ano, produzindo cerca de 30% da massa total de forragem durante a estação fria, em Piracicaba, semelhante ao Marandu. Tifton 85 produziu cerca de 20% do seu rendimento médio anual durante a estação fria. Tifton 85 teve PB maior do que as outras duas gramíneas, quando colhidas em intervalos mais curtos e quando irrigadas. A concentração de FDN em Convert HD 364 foi menor do que nas outras gramíneas, independentemente da irrigação, da frequência de colheita e das estações do ano, resultando em alta DIVMO (mais de 650 g kg-1), semelhante à do capim Marandu. Em relação à calibração do CROPGRO, em geral, o desempenho do modelo foi bom para as três gramíneas. Simulações de massa de folha e colmo foram melhoradas para os capins, devido ao aumento na partição de assimilados direcionados para colmo em condição de baixa freqüência de colheita. O IAF e IL foram bem simulados pelo modelo, mostrando aumento com a diminuição da freqüência de colheita, com exceção do Tifton 85. Em condição não irrigada, as simulações utilizando o método de Penman -Monteith - FAO 56 deram respostas mais realistas de estresse hídrico do que usando o método de Priestley e Taylor. Os resultados da calibração sugerem que o modelo CROPGRO - forragem perene pode ser usado para simular adequadamente o crescimento de Marandu, Convert HD 364 e Tifton 85 sob condições irrigadas e não irrigada, sendo capaz de simular diferentes manejos de frequência de desfolhação.

Grasses of the genera Brachiaria and Cynodon are some of the most important pasture introductions in Brazil. Convert HD 364 brachiariagrass, a new Brachiaria hybrid, was released as an option for a broad range of environmental conditions, high nutritive value and forage production. Forage-based livestock systems are complex and interactions among animals, plants, and the environment exist at several levels of complexity, which can be evaluated using computer modeling. Herbage accumulation, crude protein (CP), neutral detergent fiber (NDF), in vitro organic matter digestibility (IVOMD), plant-part composition, leaf photosynthesis, leaf area index (LAI), and light interception (LI) were evaluated as affected by two harvest frequency (28 and 42-days), irrigated and rainfed in a clipping study from April 2011 to April 2013, contrasting Convert HD 364® brachiariagrass (Brachiaria hybrid CIAT 36061), Marandu palisadegrass {Brachiaria brizantha (Hochst. ex A. Rich.) R. D. Webster [syn. Urochloa brizantha (A. Rich.) Stapf]; CIAT 6297}, and Tifton 85 bermudagrass (Cynodon spp.). The experimental design for both the irrigated and the rainfed trials was a randomized complete block with four replications. Convert HD 364 had similar or higher annual herbage accumulation, seasonal yield and herbage accumulation rate than Marandu and Tifton 85, (15% more herbage accumulation than Marandu and 12% more than Tifton 85 when irrigated and when harvested at shorter regrowth intervals). Convert HD 364 had good seasonal distribution of total annual herbage produced and accumulates about 30% of the total herbage mass during the cool season in Piracicaba, similar to Marandu. Tifton 85 produced around 20% of its average annual yield during dry season. Tifton 85 forage had higher CP concentration than the other two grasses when harvested at shorter intervals and when irrigated. The NDF concentration in Convert HD 364 was lower than in the other grasses regardless of irrigation treatment, harvest frequency, and season of the year, resulting in high IVOMD (more than 650 g kg-1), similar to that of Marandu. Regard to CROPGRO calibration, in general the model performance was good for the three grasses. Leaf and stem weight simulations were improved, due to increase partitioning to stem for low harvest frequencies. The LAI and LI were well performed by the model, showing increase for lower harvest frequency, with exception to Tifton 85. Under rainfed conditions, the simulations using the Penman-Monteith-FAO 56 method gave more realistic water stress responses than using the Priestley and Taylor method. Calibration results suggest that the CROPGRO - Perennial Forage Model can be used to adequately simulate growth of Marandu, Convert HD 364, and Tifton 85 under irrigated and rainfed conditions, being able to simulate different harvest frequency managements. / As gramíneas do gênero Brachiaria e Cynodon são algumas das pastagens cultivadas introduzidas no Brasil de maior importância. Convert HD 364, um novo híbrido de Brachiaria, foi lançado como uma opção para uso numa ampla gama de condições ambientais, com alto valor nutritivo e produção de forragem. Sistemas pecuários em pastagens são complexos e as interações entre os animais, as plantas e o meio ambiente existem em vários níveis de complexidade, que podem ser avaliados utilizando modelagem computacional. Acúmulo de forragem, proteína bruta (PB), fibra em detergente neutro (FDN), digestibilidade in vitro da matéria orgânica (DIVMO), a composição morfológica da planta, fotossíntese foliar, índice de área foliar (IAF) e interceptação luminosa (IL) foram avaliados em resposta à duas frequências de colheita (28 e 42 dias), irrigada e não irrigada, em um estudo com parcelas colhidas mecanicamente a partir de abril de 2011 até abril de 2013, contrastando os capins Convert HD 364® (Brachiaria híbrida CIAT 36061), Marandu {Brachiaria brizantha (Hochst. ex A. Rich.) RD Webster [syn. Urochloa brizantha (A. Rich.) Stapf]; CIAT 6297} e Tifton 85 (Cynodon spp.). O delineamento experimental utilizado tanto para o irrigado quanto para o não irrigado foi de blocos casualizados, com quatro repetições. Convert HD 364 teve acúmulo de forragem anual, produção sazonal de forragem e taxa de acúmulo de forragem semelhante ou superior ao Marandu e Tifton 85, (acúmulo de forragem 15% maior do que Marandu e 12% maior do que o Tifton 85, quando irrigado e colhido em intervalos de rebrotação mais curtos). Convert HD 364 teve boa distribuição sazonal de forragem total do ano, produzindo cerca de 30% da massa total de forragem durante a estação fria, em Piracicaba, semelhante ao Marandu. Tifton 85 produziu cerca de 20% do seu rendimento médio anual durante a estação fria. Tifton 85 teve PB maior do que as outras duas gramíneas, quando colhidas em intervalos mais curtos e quando irrigadas. A concentração de FDN em Convert HD 364 foi menor do que nas outras gramíneas, independentemente da irrigação, da frequência de colheita e das estações do ano, resultando em alta DIVMO (mais de 650 g kg-1), semelhante à do capim Marandu. Em relação à calibração do CROPGRO, em geral, o desempenho do modelo foi bom para as três gramíneas. Simulações de massa de folha e colmo foram melhoradas para os capins, devido ao aumento na partição de assimilados direcionados para colmo em condição de baixa freqüência de colheita. O IAF e IL foram bem simulados pelo modelo, mostrando aumento com a diminuição da freqüência de colheita, com exceção do Tifton 85. Em condição não irrigada, as simulações utilizando o método de Penman -Monteith - FAO 56 deram respostas mais realistas de estresse hídrico do que usando o método de Priestley e Taylor. Os resultados da calibração sugerem que o modelo CROPGRO - forragem perene pode ser usado para simular adequadamente o crescimento de Marandu, Convert HD 364 e Tifton 85 sob condições irrigadas e não irrigada, sendo capaz de simular diferentes manejos de frequência de desfolhação.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this research was to evaluate the productivity and nutritive value of elephant grass pastures, subjected to conventional and organic production system. In the conventional system elephant grass was planted in rows 1.2 m apart from each other. In the organic system elephant grass was planted in rows 3 m apart from each other. In the space between rows, in cool season, annual ryegrass was sown; allowing the development of spontaneous growing species in the warm season. It was applied 100 kg of N/ha from chemical and organic fertilizers (manure of cattle and pig slurry) in the respective pastures. The grazing method was rotated with time to occupy the two days. Holstein cows receiving 0.9% of body weight complementary concentrate feed were used. Pre and post grazing forage mass, botanical and structural composition, forage production and stocking rate were evaluated. Hand-plucked samples were collected to analyze chemical composition and digestibility. Experimental design was completely randomized with two treatments (forage systems), three replicates (paddocks) and repeated measures (mean values of grazing cycles or season). Eight and seven grazing cycles were performed during the experimental period for respective systems. Organic system present best forage distribution thought the year and highest participation of elephant grass leaf blades on herbage mass. The pasture under conventional system presented higher forage mass and stocking rate. Similar value was found in the chemical composition and digestibility of elephant grass pastures in both pasture systems. The organic as much as conventional system showed high qualitative values considering the fertilization, manage and utilization time, in proposed strategy. The results show that the elephant grass can be used under the organic system proposed. / Objetivou-se com esta pesquisa avaliar a produtividade e o valor nutritivo de pastagens de capim elefante submetidas aos sistemas de produção orgânico e convencional. No sistema convencional, o capim elefante foi plantado em linhas afastadas a cada 1,2 m. No sistema orgânico, o capim elefante foi plantado em linhas afastadas a cada 3 m; no espaço entre as linhas, no período hibernal, foi semeado o azevém anual e, no período estival, permitiu-se o desenvolvimento de espécies de crescimento espontâneo. Foram utilizados 100 kg de N/ha com fertilizantes químico e orgânico (esterco de bovino e chorume de suínos) para os respectivos sistemas de produção. O método de pastejo adotado foi o rotacionado, com tempo de ocupação de um ou dois dias, utilizando vacas em lactação que receberam complementação alimentar com concentrado à razão de 0,9% do peso vivo. Foram avaliados a massa de forragem de pré-pastejo e pós-pastejo, composições botânica e estrutural, taxa de desaparecimento, e de acúmulo, produção de forragem e carga animal. Para a determinação da composição química e digestibilidade da forragem, foram retiradas amostras simulando o pastejo. O delineamento experimental foi o inteiramente casualizado com dois tratamentos (sistemas forrageiros), com três repetições (piquetes) e com medidas repetidas (valores médios dos pastejos em cada ciclo ou estação do ano). Durante o período experimental, foram conduzidos oito e sete pastejos para os respectivos sistemas. Na pastagem sob o sistema orgânico, houve melhor distribuição de forragem e maior participação de lâminas foliares do capim elefante na massa de forragem. Na pastagem sob o sistema convencional, verificaram-se maiores valores de produção de forragem e carga animal. Valores similares foram observados quanto à composição química e digestibilidade do capim elefante em ambos os sistemas. Na estratégia proposta, tanto no sistema orgânico quanto no convencional apresentaram teores qualitativos elevados, considerando-se a adubação, manejo e tempo de utilização. Os resultados demonstram que o capim elefante pode ser utilizado segundo o sistema de produção orgânico proposto.