Two tropical legumes and a temperate legume were studied during the course of this work. These were Leucaena leucocephala (cv. Peru), Canavalia ensiformis(cv. unknown) and Lupinus albus (cv. Vladimir [Kievskji mutant]) respectively. The dried ground leaf obtained from Leucaena leucocephala (LLM), the seeds of Canavalia ensiformis (jack bean; JB) and Lupinus albus (lupin) were the materials used in the study. Liquid chromatographic methods (HPLC) were developed for the analysis of mimosine and 3-hydroxy-4(lH )-pyridone (3,4-DHP) in LLM, Leucaena seed (LS) and chick excreta. Neither mimosine nor 3,4-DHP wftS detected in the serum of chicks fed LLM. Poor and variable recoveries of mimosine and 3,4-DHP were obtained when these were added to serum The analysis of canavanine in JB and the serum of chicks fed JB and canavanine, was also accomplished using HPLC. Canaline was not detected in any of the samples analysed by HPLC although recovery of added canaline to serum, JB and excreta was high. A small amount of what appeared to be canavanine was detected in lupin. Saponins and tannins were found in all the legumes under study. Trypsin inhibitors were detected in all but the lupins Inclusion of LLM in chick diets reduced their performance. Addition of Fe(III), polyethylene glycol (RAM = 4000) and cholesterol to LLM diets improved chick performance almost to that of chicks fed control diets. Cooking LLM alsoimproved chick performance. Addition of enzymes to LLM did not improvechick performance and did not improve the apparent metabolisable energy (AME) of LLM. Dietary inclusion of mimosine or LS, to supply the same amount of mimosine as that from LLM, did not restrict chick performance to the same extent as LLM Inclusion of autoclaved jack bean (JB) in chick diets caused a severe reduction in chick performance. The reduction in performance was not matched byinclusion of canavanine at the same level as that from JB. The inclusion ofextracted JB also reduced chick performance. Germination of the JB, prior to autoclaving and dietary inclusion, did not reduce canavanine levels nor was chick performance improved. Addition of arginine to JB diets improved performance of chicks but additional lysine had no beneficial effect. Lupin diets perm itted chicks to perform much better than LLM or JB diets. Autoclaving made little difference to the AME of lupins although the results were probably confounded by the presence of M aillard reaction products. Addition of enzymes to lupins increased the concentration of lower molecular weight carbohydrates but only had a small beneficial effect on AME of lupins for chicks.

The problem addressed in this thesis is the role of external development aid in the growth process with special reference to Sudan's experience of growth and development with foreign aid resources over the past two decades (1960-1980). The study is taken in the light of the basic ideas on which foreign aid theories have been conceived and in view of the critics of aid argument. Chapter 1 presents the aim of the study, the method of approach and the outline of the study. In Chapters 2 and 3 we present a review of the basic approa to the theory of foreign aid in economic growth, and examine the criticisms regarding the validity of their assumptions and operation-11. al usefulness as well as the modifications introduced to them. In Chapters 4 and 5 we highlight the salient features of the structure of the Sudanese economy and analyze the development performance and constraints over the past two decades in the light of the growth constraints identified by aid growth models. Chapter 6 consists of an account of the general characteristics of the flow of external development aid received by the Sudan during the period of study. Chapters 7and 8 deal explicitly with the impact of foreign resources on domestic savings, investment and growth with reference to Sudan's experience over the past two decades. Chapter 9 considers the problems that hindered the effective use of foreign aid resources in the Sudan during the period of study and highlights the main areas in which reform measures are needed. In Chapter 10 an estimate of the savings gap and the foreign exchange gap for the Sudan for the forthcoming Six Year Plan 1983/84-1988/89 is provided on the basis of the two gap approach.

Triasulfuron (3-(6-methoxy-4-methyl-1,3,5-triazin-2-yl)-1-[2-(2- chloroethoxy)-phenylsulfonyl)-urea} is a new pre- and post-emergence herbicide developed for the control of broad-leaved_'Teeds and some grasses in small grain cereals at rates of 10-20gha . Oilseed rape, pea, broad bean, Senecio vulgaris, Veronica persica, Lolium renne, Poa annua, Poa trivialis and prates were severely a ed 5y pre-emergence and post-emergence applications of triasulfuron but wheat and barley were much more resistant. The development of injury symptoms was generally slow and was characterized by an initial growth retardation followed by chlorosis and necrosis with death occuring 3-4 weeks after application. The herbicide had a flat dose-response curve throughout the investigations. Wheat and barley showed greater tolerance to post-emergence than to pre-emergence applications. Pre-emergence applications of triasulfuron reduced tiller numbers in barley and wheat but application of the herbicide at the 2-3 leaf stage stimulated the outgrowth of tiller buds but this effect was temporary and was not the result of visible physical damage to the shoot meristem. There was no intra-specific variability between cultivars of wheat and barley. Grain yield and other yield components of spring barley were not affected by post-emergence treatments of triasulfuron. Triasulfuron had high activity through the soil and both the roots and subterranean shoots of developing seedlings absorbed the herbicide from the soil. The bioactivity and mobility of the herbicide down the soil profile was inversely related to the organic matter content of the soil. The amount and frequency of rainfall directly influenced the rate of leaching of the herbicide down the soil profile. Comparisons of the rates of disappearance of triasulfuron in autoclaved and non-autoclaved soils suggested the involvement of a biglogical degragation pathway. Triasulfuron disappeared faster at 30 °C than at 10 °C and higher moisture levels enhanced the rate of breakdown. Studies on the mode of action of triasulfuron indicated that the herbicide acts by inhibiting cell division in susceptible plants. Evidence suggested that the inhibition occurred during interphase rather than during the mitotic sequence. The addition of a 1: 1 mixture of isoleucine and valine to the treatment solution prevented the inhibition of cell division at the root tips of broad bean.

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Abstract Twenty-seven phosphine and six bipyridine ligands were synthesised and characterized. Additionally, a new route to the family of phosphine ligands via o-thioanisyldichlorophosphine was found. The phosphine ligands contain thiomethylphenyl, methoxyphenyl, dimethylaminophenyl, pyridyl, naphthyl and anthracenyl groups, and the bipyridine ligands thiomorpholine and piperidine groups. Metal complexes of 3-pyridyldiphenylphosphine, 6,6'-bis(methylthiomorpholine)-2,2'-bipyridine and 4,4'-dimethyl-6,6'-bis(methylthiomorpholine)-2,2'-bipyridine were prepared. Ligands and complexes were characterized by 1H-, 13C-, 31P- and two-dimensional HSQC-NMR spectroscopy, and crystal structures were determined for the ligands and two of the metal complexes. Tertiary phosphine ligands were prepared for catalytic purposes and tested in hydroformylation reaction at the Helsinki University of Technology and the University of Joensuu. Bipyridine ligands were designed for bimetallic coordination. The phosphine ligands cover a wide range of electronic and steric properties. The spectroscopic parameters and crystal structures were studied with the purpose of charting trends in the basicities and steric effects of the ligands.

No description available.

Gamma-thujaplicin (GT) and beta-hydroxy thujaplicin (BHT) are two of the isopropyl derivatives of tropolone found in the heartwood of western red cedar (Thuja plicata D. Don). Several of the tropolones are effective inhibitors of the enzyme catechol-O-methyltransferase (COMT). In this work, the isolated, spirally-cut rabbit thoracic aorta preparation has been used to study possible COMT inhibition as well as other pharmacological properties of the sodium salts of GT and BHT. It was found that GT, BHT and pyrogallol, a known COMT inhibitor, all potentiated the response of the aortic strip to norepinephrine (NE). However, since it was shown that the chelating agent EDTA also potentiated the NE response, the potentiation by GT and BHT could not be attributed to COMT inhibition without further evidence. GT and BHT were found to have a stimulatory effect of their own on aortic smooth muscle tissue. BHT was a more potent agonist than GT. Phenoxybenzamine blocked the stimulatory effects of BHT and GT. This suggested alpha-adrenergic receptor involvement although the halogenoalkylamine blocking agents are not absolutely specific in their action. Cocaine produces a small potentiation of the contraction produced by GT and BHT. This potentiation suggests the involvement of endogenous NE. Cocaine does not cause relaxation of the GT and BHT responses which indicates that GT and BHT differ in mode and perhaps site of action from tyramine. BHT potentiates the tyramine response on the rabbit aortic strip. This may be due to COMT inhibition, increased NE release or merely additive effects. GT was found to produce relaxation of a histamine-induced contraction. This relaxant effect was not prevented by beta-adrenergic blockade and is likely due to a nonspecific depressant effect by GT. Both GT and BHT have produced non-specific blocking effects against NE and histamine as well as acetylcholine throughout this work. In reserpinized preparations, GT no longer produced a contraction of the aortic strip. Instead, a relaxation below normal tone was produced. It would seem that the presence of endogenous NE is required in the tissue stores before GT can cause the strips to contract. GT causes relaxation of tyramine-induced contractions in reserpinized strips. The isolated rabbit thoracic aorta was found not to be a suitable preparation for the pharmacological investigation of COMT inhibition by GT and BHT due to their own agonistic effects on this tissue as well as their nonspecific chelating properties. However, this tissue was useful in providing information on other pharmacological actions of these compounds. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate

The suspected teratogenicity of Diphenylhydantoin (DPH) in man is important, especially to the 0.3 to 0.5% of pregnant women who are epileptic and, therefore, candidates for anticonvulsant drug therapy. To separate the teratogenic effect of epilepsy from DPH treatment, an animal model closely approximating the human condition was developed to meet the following criteria: (i) the test animal must have spontaneous seizures (ii) the seizures must be controlled or eliminated by DPH treatment (iii) the drug must be administered orally (iv) serum DPH levels must fall within the optimal human therapeutic range between 5 and 20 micrograms per ml serum (v) treatment must begin prior to mating and continue throughout gestation (vi) the offspring of treated animals must exhibit the spectrum of malformations observed in the offspring of epileptic women The first criterion was met by mutant quaking (qk) mice. The seizure activity of these animals was reduced (from 2.1 to .34 seizures per mouse day) by DPH treatment. To separate the effect of this gene from that of the DPH in the etiology of the malformations, heterozygous (+/qk) and homozygous non- quaking (+/+) mice were also studied. Monitoring of DPH levels with the SYVA Emit spectrophotometry assay technique indicated serum concentrations within the human therapeutic range at 40 and 60 mg/kg body weight dosages. The incidence of fetuses born with skeletal or soft-tissue abnormalities increased with increasing DPH dosages. This was observed in all three genotypes. The ability of the untreated quaking (qk/qk) dams to -produce normal offspring implicates the drug rather than the mutant gene as the cause of malformations. A preliminary application of this animal model produced what can be considered the mouse equivalent of the fetal hydantion syndrome. The similarities between the human and mouse syndromes include prenatal growth deficiency, neural, cardiac, orofacial, ocular and genitourinary anomalies. Further large-scale application of the model should provide insight into the role of DPH in the etiology of the malformations observed amongst the offspring of epileptic women on hydantoin anticonvulsant drug therapy. / Medicine, Faculty of / Medical Genetics, Department of / Graduate