Limited studies focused on reactions occurring during disinfection and oxidation processes of seawater. The aim of this work was to investigate disinfection by-products (DBPs) formation from the chlorination and chloramination of seawater algal organic matter and related model compounds. Simulated algal blooms directly growing in Red Sea, red tide samples collected during an algal bloom event and Hymenomonas sp. monoculture were studied as algal organic matter sources. Experiments were conducted in synthetic seawater containing bromide ion. A variety of DBPs was formed from the chlorination and chloramination of algal organic matter. Brominated DBPs (bromoform, DBAA, DBAN and DBAcAm) were the dominant species. Iodinated DBPs (CIAcAm and iodinated THMs) were detected, which are known to be highly toxic compared to their chlorinated or brominated analogues. Algal organic matter was found to incorporate important precursors of nitrogenous DBPs (N-DBPs), which have been reported to be more toxic than regulated THMs and HAAs. Isotopically-labeled monochloramine (15N- NH2Cl) was used in order to investigate the nitrogen source in N-DBPs. High formation of N-DBPs was found from Hymenomonas sp. sample in exponential growth phase, which was enriched in nitrogen-containing organic compounds. High inorganic nitrogen incorporation was found from the algal samples enriched in humic-like compounds. HAcAms formation was studied from chlorination and chloramination of amino acids. Asparagine, aspartic acid and other amino acids with an aromatic structure were found to be important precursors of HAcAms and DCAN. Factors affecting HAcAms formation (Cl2/ amino acid molar ratio and pH) were evaluated. Studies on the formation kinetics of DCAcAm and DCAN from asparagine suggested a rapid formation of DCAcAm from organic nitrogen (amide group) and a slower incorporation of inorganic nitrogen coming from monochloramine to form DCAN. High amounts of DCAN and DCAcAm were detected from the chloramination of aromatic compounds (i.e., phenol and resorcinol) indicating that N-DBPs can also be formed from organic compounds without any organic nitrogen through the incorporation of inorganic nitrogen from monochloramine. Moreover, results from Hymenomonas sp., aromatic amino acids, and phenolic compounds suggested that aromatic compounds are highly reactive with monochloramine and a major fraction of DBP precursors.

Platinum complexes (cisplatin, carboplatin and oxaliplatin) are effective anticancer agents. However the major drawbacks of platinum chemotherapy are toxic side effects and resistance. The affinity of platinum complexes to sulfur donor ligands of side chains of methionine and cysteine amino acids was assumed to be responsible for toxicity and resistance. Recently, it was found that the reaction of platinum complex with proteins containing sulfur donor ligands could actually favor its anticancer activity. Copper transporter 1 (Ctr 1), a protein involved in the transport of copper into the cell, also helps in the influx of cisplatin by binding to N-terminal domain of Ctr 1 which is rich in methionine and histidine residues. A better understanding of how the size and shape of amine ligand, and leaving groups affect the reaction of platinum (II) complexes with methionine could give new ways to optimize its anticancer activity. This preliminary research focuses to answer this by HPLC-UV-VIS analysis of bulky platinum complexes including [Pt(dien)Cl]Cl, Pt(Me4en)(NO3)2 and Pt(en)(NO3)2 with two methionine containing small peptides that serve as models for protein interactions.

Introduction. Ecological farming occupies a special position among various technologies in agriculture. It is based on modern, environment friendly technologies which do not use synthetic chemical substances (fertilizers, pesticides, drugs, growth enhancers, etc.), but use their substitutes instead. Ecological rabbit breeding is a novelty in Lithuania; however, the observations prove that the number of those willing to run such farms is increasing. The conditions of rabbit keeping must be as close to natural as possible to assure that the wellbeing and health requirements for the animals are fulfilled. Rabbits must have a possibility to move freely, satisfy their instincts. Goal of research. The research aims to study the digestibility of nutrients in rations used for feeding rabbits with ecological feedstuffs. Method of research. The research has been carried out at the vivariums of Lithuanian Veterinary Academy using New Zealand rabbit breed. To study digestibility 3 groups were formed, 10 rabbits aged 60days were selected from each group. The rabbits were kept in individual cages and had sufficient of water. The same feedstuffs as on ecological farms were used. The research consisted of the following stages: 1. Adaptation (duration – 3 days); 2. Preparatory stage (duration – 5 days); 3. Collection of faeces and stale (duration – 5 days). Review of research data. The crude protein and raw fat in ration perform a specific function of life-support and production, in case of... [to full text]

Although some physiological effects of toxic metal poisoning have been known for centuries, the specific chemical interactions between biological molecules and mercury(I), mercury(II) or lead(II) are not well understood. To date, only thirteen crystal structures of inorganic mercury-amino acid complexes and six crystal structures of lead-amino acid complexes have been reported with varying degrees of characterization. In order to improve our understanding of the coordination chemistry of mercury and lead in biological environments, a systematic method for the isolation of inorganic metal-amino acid complexes from acidic aqueous solutions has been developed. With this method we have prepared five new lead-amino acid complexes (with L-valine, L-isoleucine, L-phenylalanine, and L-arginine) and four new mercury-amino acid complexes (with L-alanine, D-alanine, L-proline, and N-methyl-L-alanine). These metal-amino acid complexes have been comprehensively characterized in the solid state, solution state and gas phase. The development of this isolation technique in conjunction with the exploration of a number of characterization techniques for studying metal-amino acid interactions greatly enhances the known methods by which metal-biological molecule systems are studied.

Mechanically pressed Brassica napus L. meals’ digestibility nutritional compositions were evaluated with digestibility studies. Two growth trials were conducted identifying the meals’ maximum dietary inclusion level in broiler chicken diets. Heat reduced nutrient digestibility of mechanically pressed black canola meal (MPBCM). Meals with higher residual oil had higher AMEn. Enzyme addition did not affect MPBCM AMEn but increased standardized ileal amino acid digestibility (SIAAD) of meal with high residual oil. Carbohydrase increased AMEn of mechanically pressed yellow canola meal (MPYCM) while lipase generally improved SIAAD. MPBCM with 12 and 17% residual oil can be fed up 15% in the starter and grower diets but at 10% in finisher diet. Mechanically pressed black canola meal (MPYCM) with 12% residual oil should be fed in the starter and finisher diets at 10% and 15% in grower diet. Meal with 17% residual oil should be fed only at 10% in finisher diet. / Masters Thesis

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Postprandial urea production in subjects with insulin dependent diabetes mellitus (IDDM) on conventional insulin therapy is normal when the previous diet is high in protein, but there is an incomplete adaptive reduction in urea production following protein restriction. To evaluate the nutritional implications of restricted protein intake in human diabetes mellitus, it is first necessary to establish a reliable method to measure changes in urea production and amino acid catabolism in response to changes in dietary protein intake. We therefore tested (1) the accuracy of the urea production rate (Ra) to depict changes in urea production, (2) whether sulfate production can be accurately depicted using tracer or nontracer approaches, after establishing the use of electrospray tandem mass spectrometry to measure sulfate concentrations and 34SO4 enrichments following administration of the stable isotope tracer sodium [34S]sulfate, (3) the reproducibility of urea and sulfate measurements following a test meal low in protein (0.25 g/kg) in subjects previously adapted to high (1.5 g/kg.d) and low (0.3 g/kg.d) protein intakes, and compared the metabolic fate of [ 15N]alanine added to the test meal with that of [15N] Spirulina platensis, a 15N-labeled intact protein, and (4) whether we could identify the differences in postprandial urea and sulfate productions between normal subjects and persons with IDDM receiving conventional insulin therapy previously adapted to high protein intake, when the test meal was limiting in protein. Under basal conditions, steady state urea Ra is an accurate measure of urea production. Following changes in urea production, both the tracer and nontracer methods seriously underestimated total urea Ra. The tracer method overestimated sulfate production by 20%, but the nontracer method provided an accurate measure of sulfate production and, hence, sulfur amino acid catabolism. Postprandial changes in urea and sulfate productions following normal ada

Cyperus rotundus L. CYPRO (purple nutsedge) and Cyperus esculentus L. CYPES (yellow nutsedge) are problematic weeds on every continent. At present there is no comprehensive means of controling these weeds.. The primary means of control is herbicides, although the weeds are becoming more resistant. Bioherbicide control of purple and yellow nutsedge is an important avenue of research, with much of the focus being to increase the virulence of current fungal pathogens of C. rotundus and C. esculentus. The primary aim of this study was to increase the virulence of a fungal pathogen of C. rotundus and C. esculentus, with the objective of creating a viable bioherbicide. A possible means of increasing the virulence of a pathogen would be to increase the amount of amino acid produced by the fungus. This was proposed as a means of increasing the virulence of Dactylaria higginsii (Luttrell) M. B. Ellis. Overproduction of amino acids such as valine and leucine result in the feedback-inhibition of acetolactate synthase (ALS), an enzyme which is a target for many herbicides currently on the market. By applying various amino acids to tubers of purple nutsedge and comparing the results with a reputable herbicide, glyphosate, it was possible to determine the success of the amino acid applications. Only glutamine treatment at 600 mg.r1 resulted in significantly less (P<O.OOI) germination compared with the water control, while the glyphosate application resulted in no germination. Four treatments were significantly different (P<O.OOI) from the water control in terms of shoot length, but no pattern or conclusion could be drawn from the results. Injecting amino acids and glyphosate into the leaves of the plants gave similar results to those obtained with the tubers, with no visible damage on those plants injected with the amino acids and complete plant death of those injected with glyphosate. Amino acids had little effect on the growth of the C. rotundus plant or tuber. It was later determined by a colleague (Mchunu1 , unpublished) working on the same project, that D. higginsii does not infect the local ecotypes of C. rotundus in Pietermaritzburg, South Africa. A second fungus, Cercospora caricis Oud., was isolated from C. rotundus growing in the region, and confirmed as a Cercospora species by conidial identification. Like many Cercospora species, C. caricis produces a phytotoxin, cercosporin. An increase in production of cercosporin would theoretically lead to an increase in virulence of C. caricis. Mutation of hyphae by i J Makhosi Mchunu: Address: National department ofAgriculture; Private Bag 3917; Port Elizabeth; 6056 Email: Makhosimc@NDA.agric.za ultraviolet-C light was perfected on C. penzigii Sacc., where 5 min exposure to DV-C light resulted in approximately 99% cell death. Surviving colonies were analysed by spectrophoresis, and the surviving mutant gave an absorbance value of approximately 5% more than the median. Samples were analysed by high-performance liquid chromatography (HPLC) to determine the presence of cercosporin. No definitive result was obtained. Exposure of C. caricis to DV-C for 5 min. resulted in approximately 65% hyphal cell death, with 20 min. resulting in approximately 95% death. A spontaneous mutant was observed in a colony that had been exposed to DV-C. This mutant showed sectored growth with red and grey growth patterns. The red section of the mutant was subcultured and analysed by spectrophoresis and HPLC. The red C. caricis gave an absorbance reading of approximately 140 on HPLC compared with about 22 from the grey colony. HPLC analysis of the wild-type C. caricis did not produce a peak corresponding to that of the cercosporin standard, although no conclusion could be obtained on the presence or absence ofthe toxin. The virulence of the mutant C. caricis could not be determined as inoculation experiments were unsuccessful, and had to be discontinued due to time constraints. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

Au nanoparticles are increasingly being used in biological applications. Their use is of interest based upon their unique properties that are achieved at the nanoscale, which includes strong optical absorbances that are size and aggregation state dependent. Such absorbances can be used in sensitive chemical/biological detection schemes where bioligands can be directly attached to the nanoparticle surface using facile methods. Unfortunately, a number of complications persist that prevent their wide-scale use. These limitations include minimal nanoparticle stability in biological-based media of high ionic strength, unknown surface functionalization effects using simple biomolecules, and determining the binding motifs of the ligands to the nanoparticle surface. This situation can be further complicated when employing shaped materials where crystallographic facets can alter the binding potential of the bioligands. We have attempted to address these issues using traditional nanoparticle functionalization techniques that are able to be characterized using readily available analytical methods. By exploiting the optical properties of Au nanomaterials, we have been able to determine the solution stability of Au nanorods in a buffered medium and site-specifically functionalized Au nanomaterials of two different shapes: spheres and rods. Such abilities are hypothesized to be intrinsic to the bioligand once bound to the surface of the materials. Our studies have focused mainly on simple amino acids that have demonstrated unique assembly abilities for the materials in solution, resulting in the formation of specific patterns. The applications for such capabilities can range from the use of the materials as sensitive biochemical sensors to their directed assembly for use as device components.

Obesity is an ever-growing concern in the developed world that carries with it a plethora of health issues. For example, obesity increases an individual’s risk for Type 2 Diabetes and cardiovascular disease. Pregnancy is a vital time for a woman to maintain optimal health, both for her own benefit as well as that of her offspring, and yet almost half of women in the United States who are of age to bear children are overweight or obese. In mice, we found that offspring born to dams fed a high fat diet did not have impaired glucose tolerance, contrary to our hypothesis. In addition, we challenged the offspring with a high fat diet, and found no difference in glucose tolerance as a result of maternal diet. Exercise is at the opposite end of the wellness spectrum – individuals who exercise experience many health benefits. Even overweight or obese individuals who exercise without losing weight have improved insulin sensitivity, for example. Studies have previously used voluntary running and found that offspring born to exercised dams have improved glucose tolerance. With the goal of controlling variable running times and distances, we developed a novel model of controlled exercise and have shown that it is a safe intervention that warrants further study. In addition, many individuals choose to take dietary supplements for various reasons. Branched chain amino acids (BCAAs) are a common dietary supplement that have been shown to increase lean mass, and may be implicated in glucose metabolism. We supplemented female mice with BCAAs for 16 weeks and found that exercise plus BCAAs improved body composition compared to sedentary control-diet fed animals, when exercise alone did not. In summary, we herein explore a number of health behaviors in female mice, both negative treatments such as consumption of a high fat diet and positive interventions such as exercise and BCAA supplementation, and the impact that they may have on the female animal and/or her offspring.