Nutrient pollution from industrial activity is an environmental problem that persists in water bodies near urban settings, and has been a primary contributor to eutrophication, bacterial contamination, and harmful algal blooms. Biogenic iron oxides offer a potential solution to the treatment of lakes and rivers containing high concentrations of phosphate, the limiting nutrient in aquatic systems. Soluble ferrous iron can act as an electron donor for iron-oxidizing bacteria, which thrive in low-oxygen environments. This results in the formation of insoluble ferric iron minerals, ideal adsorbents for negatively charged phosphate. Conversely, iron-reducing bacteria reduce ferric iron to form ferrous iron, resulting in the formation of secondary minerals depending on the chemistry of the particular environment. This project investigates the chemical conditions at which biogenic iron oxides have the maximum adsorptive capacity, especially with respect to organic carbon content. A simplified model of natural biogenic iron oxides was synthesized by co-precipitating the mineral ferrihydrite (a common iron oxide) with the polysaccharide alginate, an analogue to bacterial exopolysaccharides. At the levels of carbon investigated, organic matter was not found to affect the adsorptive capacity of iron oxides at the C/Fe ratios analyzed. Similarly, organic matter did not appear to significantly influence the rate of reduction of ferrihydrite by the iron-reducing bacterium Shewanella putrefaciens CN32. Presence of organics did however influence rates of reduction and the mineralogy of the post-reduction precipitates. Phosphate adsorbed to iron oxides prior to microbial reduction greatly increased both the rate and the extent of ferric iron reduced, and also had an impact on the secondary minerals that formed (vivianite, green rust). An improved understanding of these conditions could contribute to a more efficient process by which iron-oxidizing bacteria are used for large-scale industrial water treatment.

South Africans frequently consume red meat as part of their diet. However the nutrient content of South African sheep meat is derived from other countries. The Red Meat Industry considered it essential to have more reliable data and thus the nutrient content of A2 South African lamb was recently determined and published. This is the next phase of the study in which the right sides of C2 mutton carcasses were used to determine the nutrient and physical (carcass) composition of each raw cut as well as the whole carcass by calculation. Eighteen mutton carcasses of the most commonly consumed breeds, namely Dorper and Merino, in South Africa were selected. The carcasses were obtained from large abattoirs form three mutton producing regions in South Africa namely Ermelo, the Karoo and Kalahari. Chilled carcass sides were subdivided into ten primal cuts. Three cuts (shoulder, loin and leg) from the left side were cooked in order to determine the nutrient composition thereof. The cuts were dissected into meat which consists of muscle and intramuscular fat, intermuscular - plus subcutaneous fat and bone in order to determine the physical composition per cut and for the whole carcass. Meat compromise of 63.2% of the carcass, with bone contributing to 20.5% and fat to 16.9%. Results showed differences in the physical composition of South African C2 mutton as it contains on average 47% less fat and 19% more lean muscle, when compared to previous published composition data. Three cuts (shoulder, loin and leg) from the left side were cooked in order to determine the nutrient composition thereof. Cooking resulted in an increase in the protein and cholesterol concentrations of the cooked cuts. Iron content was higher in the cooked loin and leg but decreased in the cooked shoulder. According to nutrient density, a 100g edible portion of the leg, loin and shoulder have a nutrient density higher than one for protein, iron, zinc and vitamin B12 indicating that these cuts are a good source of these specific nutrients. A 100g edible portion of the loin cut contained higher fat quantities than the cooked shoulder and leg cuts. The loin cut also had a higher cholesterol content at 70.8mg compared the 58.5mg cholesterol content in the shoulder and 57.9mg in the leg cut. However, these values were calculated with all associated subcutaneous fat and it is known that many consumers trim on plate, especially the loin cut. Considering the fact that significant differences were apparent between the current study and previous data derived from other countries, it emphasizes the importance of determining the nutrient composition of South African food products in order to increase the validity of the SA food composition tables. Food-based approaches targeting the relief of micronutrient deficiency usually encourage the consumption of animal foods together with the consumption of green leafy vegetables (GLV). The inclusion of GLV and red meat, two micronutrient rich foods, can be a strategy based on mutual supplementation to combat nutritional deficiencies as it has the potential to alleviate numerous micronutrient deficiencies including iron and vitamin A deficiency. / Dissertation (MSc)--University of Pretoria, 2009. / Food Science / unrestricted

Information on different rangeland plants’ nutritive values in different parts of plant species and habitats are important in Rangelands Management. Effects of different plant parts (stems and leaves) of the Jasminum fruticans L. plant species on forage quality indicators were investigated in two regions in 2015. Plant samples were collected from Sharlogh Rangelands and cultivated in Research and Education Center of Agricultural and Natural Resources (RECANR) in Iran with completely randomized design with three replications in each plant sample. The plant leaves and stems’ samples were oven-dried at 80°C for 24 hours, then analyzed for crude protein (CP), crude fiber (CF), dry matter (DM) Ether Extract (EE), Crude Ash (CA), Metabolizable Energy (ME), and mineral elements, including Calcium (Ca) and Phosphorus (P). Results showed that the forage quality indicators in different regions were statistically significant, except for the CA. Also, nutritive values differed significantly (P<0.01) between different plant parts, except ME parameter. Results also indicated that J. fruticans due to its high tissue CP content is a valuable source of forage for livestock.

This project investigates the potential of the 27 Everglades green algal strains for producing biodiesel. The five potential strains chosen by measuring the neutral lipid content using the Nile red method were Coelastrum 46-4, Coccoid green 64-12, Dactylococcus 64-10, Stigeoclonium 64-8 and Coelastrum 108-5. Coelastrum 108-5 and Stigeoclonium 64-8 yielded the same amount of lipids in both Gravimetric and Nile red method. A linear relationship between algal biomass and lipid accumulation was seen in Coelastrum 46-4, Coccoid green 64-12, Stigeoclonium 64-8 and Coelastrum 108-5 indicating that increase in algal biomass increased the lipid accumulation. Nitrogen and phosphorous stress conditions were also studied where higher lipid accumulation was observed significantly (p < 0.05) in 64-8 Stigeoclonium and 64-12 Coccoid green. Collectively, it could be summarized that Coelastrum 108-5, Coccoid green 64-12 and Stigeoclonium 64-8 were promising in some aspects and could be used for further studies.

Study Objective. To assess the dietary intakes of children with Attention Deficit Hyperactivity Disorder (ADHD); including macro- and micronutrient intake, the percentage of low nutrient density foods in the diet, as well as specific biochemical and anthropometric parameters. Design. Observational study. Setting. Provincial ADHD Program of BC, Children’s’ Hospital, Vancouver, BC. Sample. 44 children aged 6 - 12 years with ADHD, treatment-naïve or stable on medication for 6 months or longer. Main Results. ADHD Children were taller and heavier than population norms, and significantly taller than previously reported in ADHD. Of children aged 6-8 years, 28% were below the Estimate Average Requirement (EAR) for zinc and 61% of children aged 9-12 years were below the EAR for zinc. In addition, 28% of children aged 6-8 years and 39% of children aged 9-12 years were below the EAR for copper. Only 2% of children in the sample were below lab normal cutoffs for ferritin; however, 73% had serum zinc values below lab normal cut-offs and 23% had serum copper below lab normal cutoffs. Overall prevalence of serum zinc below the 2.5 percentile was 23% compared to 2% from National Health and Nutrition Examination Survey II (NHANES) data. Additionally, mean serum copper was significantly lower than NHANES II data. Mean energy intake was comparable to mean Estimated Energy Requirement (EER) based on the age, gender, height, weight and physical activity of subjects. In addition, mean dietary intake of Low Nutrient Density foods was not significantly different from NHANES II data and there was no significant difference in energy intake or the proportion of daily energy from protein, fat, and carbohydrate than what is observed from CCHS data. Medication treatment for ADHD was not associated with altered dietary intake or nutrient status. Conclusion. Results are suggestive of low zinc status in ADHD. / Land and Food Systems, Faculty of / Graduate

Soil microbial communities can be characterized by community structure and function (community composition) across a spectrum of spatial scales, and variation in soil microbial composition has been associated with a number of environmental gradients. This study investigates the structure and function of soil microbial communities under mature, undisturbed forested sites across a range of regional climates in British Columbia and Alberta, and also examines the variation in community composition within sites. Phospholipid fatty acid analysis was used to investigate the structure of soil microbial communities and total soil microbial biomass at each site. Extra-cellular enzyme assays established the functional potential of the soil microbial community at each site. Multivariate analysis of the data showed that the soil microbial communities under different forest types did significantly separate along the regional climate gradient by both community structure and function, despite high local variation in the communities. Soil moisture content and soil organic matter concentration consistently exhibited the strongest relationship with microbial community characteristics, although the functional and structural responses to the external drivers were different. Microbial community function and structure also changed with soil depth but not with time of sampling. Microbial community function was related to the regional annual average precipitation gradient. Most of the locations exhibited unique microbial community functional profiles in their soil layers; however the enzyme activities in the samples from the driest (Ponderosa Pine) and wettest (Mountain Hemlock) locations were notably different from each other and from those of the other locations, especially in the organic layers. The moist maritime-influenced Coastal Western Hemlock (CWH) forest exhibited microbial community structural characteristics which were unique from those of the other forest locations. The higher abundance of bacteria relative to fungi in the CWH forest soils may be related to the significantly higher available nitrogen concentrations at this site. / Forestry, Faculty of / Graduate

No description available.

The importance of resource supply and herbivory in driving competitive interactions among species has been an important but contentious issue within ecology. These variables exhibit different effects on species competition when manipulated in isolation but interact when manipulated together. I tested the direct and interactive effects of nutrient addition and simulated grazing (clipping) on the competitive performance of primary producers and community structure of a seagrass bed in South Florida. One square meter experimental plots were established in a mixed seagrass meadow from August 2007 to July 2009. The experiment was a 3 x 3 factorial experiment: 3 fertility treatments: control, medium (2.4 mg N d-1 and 80 µg P day-1) and high (4.8 mg N d-1 and 160 µg P day-1) x 3 clipping intensities (0, 25% and 50 % biomass removal (G)) x 5 replicates for each treatment = 45 plots). Nutrient additions and simulated grazing were done every two months. Fertilization and simulated grazing decreased sexual reproduction in S. filiforme. Fertilization increased competitive dominance within the primary producers while simulated grazing counteracted this effect by removal of the dominant species. Fertilization ameliorated the negative impacts of simulated grazing while simulated grazing prevented competitive exclusion in the fertilized plots. Nutrient addition and simulated grazing both exerted strong control on plant performance and community structure. Neither bottom up nor top down influences was eliminated in treatments where both factors where present. The effects of fertilization on plant performance were marked under all clipping intensities indicating that the system is regulated by nutrient availability both in the presence or absence of grazers. Clipping effects were strong under both fertilized and unfertilized conditions indicating that the seagrass bed can be simultaneously under top-down control by grazers.

京都大学 / 0048 / 新制・論文博士 / 博士(医科学) / 乙第13373号 / 論医科博第6号 / 新制||医科||8(附属図書館) / (主査)教授 長船 健二, 教授 稲垣 暢也, 教授 渡邊 直樹 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

The research objectives were to examine the effect of soil nutrient status on the growth rate, reproductive development, yield components and yield of maize in a long-term trial. On the Experimental Farm of the University of Pretoria, treatments selected for this investigation were O (control), PK (nitrogen deficient), NK (phosphorus deficient), NP (potassium deficient), NPK (balanced nutrient), and WNPKM (mixture of balanced nutrient and manure). Growth analyses were performed, embryonic tassel and ear development recorded, developmental stages and rate of tasseling and silking were monitored while yield components were determined at maturity. The balanced nutrient treatment (WNPKM) plants showed the highest growth rate and produced the highest biomass while the P and K deficient treatments resulted in low growth rates and low biomass. The PK and NPK treatments were intermediate in terms of growth rate and biomass production. The WNPKM, NPK and PK treatments exhibited a high net assimilation rate (NAR) and crop growth rate (CGR), illustrating that an adequate supply of N, P and K is required for high growth rate and biomass production. Plants in the WNPKM plots exhibited early tassel initiation and ear differentiation and larger reproductive organs. Reproductive development in the PK treatment was ahead of those of the NP and NPK treatments. Nutrient stress delayed initiation and differentiation resulting in smaller reproductive organs. A linear relationship was found between leaf area indices (LAI) and the sizes of the reproductive structures. The higher the LAI the larger the size of the reproductive structures. Emergence of inflorescences was timely in plants exposed to the balanced nutrient but delayed in nutrient deficient treatments. Grain yield and the yield components were positively affected by the balanced nutrient treatment while the nutrient stress treatments reduced the yield. Copyright 2008, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Bello, ZA 2008, Effect of soil nutrient status on growth, reproductive development and yield components of maize in a long term field trial, MSc(Agric) dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-02122009-105701 / > E1251/gm / Dissertation (MSc(Agric))--University of Pretoria, 2008. / Plant Production and Soil Science / unrestricted