Subarachnoid haemorrhage secondary to ruptured cerebral aneurysm and clipping are associated with substantial morbidity and mortality. Despite favourable neurological outcomes, many patients report persistent cognitive and emotional deficits post intervention. To compare cognitive and quality of life outcomes in patients with ruptured aneurysmal subarachnoid haemorrhage treated with surgical clipping or endovascular coiling. Twenty-four patients with aneurysmal subarachnoid haemorrhage treated by clipping or coiling were retrospectively assessed by use of a battery of cognitive tests and a quality of life questionnaire. All patients had favourable grades on admission, that is, WFNS <= 2 and favourable neurological grades on discharge, that is, GOS <=2. treated with surgical clipping or endovascular coiling. Patients in the two treatment groups were matched on age, years of education and on premorbid IQ. The two groups were further matched on time from intervention to assessment and number of treatments. The cognitive performance of the treatment groups was compared to hospitalised controls, matched for age, years of education and premorbid IQ. Comparison of cognitive outcome between the two groups indicated a trend towards poorer outcome in the surgical group which achieved significance on six test measures. There were no significant differences with respect to the quality of life measure. Patients surviving aneurysmal subarachnoid haemorrhage are likely to suffer from a 'subarachnoid-induced encephalopathy' which appears to be more aggravated by the invasive nature of surgery, compared to endovascular coiling, as demonstrated by the poorer cognitive performance ofthe clipping patients.

Gibberellins 3, 4 and 7 were isolated from "Shasta" Strawberry (Fragaria X ananassa Duch.) leaves and identified by gas and thin layer chromatography. In young expanding leaves GA3 occurred at 5 times the concentration of either GA4 or GA7. CCC (2-chloroethyl-trimethylammonium chloride), SADH (Succinamic acid-2,2-dimethyl hydrazide), ethephon (2-chloroethylphosphonic acid), and UBI-P293 (2,3-dihydro-5-6-diphenyl-1,4-oxathiin) were applied to established plantings of three June-bearing strawberry (Fragaria X ananassa Ouch.) cultivars: 11 Shasta, 11 "Fresno" and "Tioga." Treatments were applied on alternate days for three weeks following anthesis of the king blossom. Levels of GA3 and GA4 were reduced by all treatments, but GA7 occurred at such low concentrations that treatment effects could not be measured statistically. Three weeks' exposure to short-daylengths (8 hours of light and 16 hours of darkness) resulted in no change in GA3 or GA7, but GA4 concentrations were significantly reduced . Leaf tissue was analyzed t o e valuate treatment effects on chlorophyll content; no significant changes were observed. No secondary flowering as a result of photoperiod , post-harvest defoliation or growth retardant treatments was observed.

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Thesis (M.Sc. (Microbiology)) -- University of Limpopo, 2023 / Plants are not only an important source of medicines, but also play a significant role in drug development for the treatment of diseases such as Tuberculosis (TB). TB is a pulmonary disease that is caused by Mycobacterium tuberculosis complex. The aim of the study is to identify and characterise antimycobacterial compounds from Dombeya rotundifolia. The plant was collected from the University of Limpopo, dried and ground into fine powder. Extraction was done using different solvents that differ in polarity. The plant was screened and analysed for phytochemicals. Three major phytochemicals were quantified using reagent assays and analysed using standard curves. The antioxidant activity of the plant was determined using 2,2-Diphenyl-1- picrylhydrazyl (DPPH) and ferric reducing power assay. The antibacterial activity of the plant extracts was tested against Mycobacterium smegmatis using bioautography and serial microplate broth dilution assay. The antibiofilm activity of the plant extracts were evaluated using crystal violet assay. The anti-inflammatory activity of the plant was determined using egg albumin protein denaturation assay. The cytotoxic effects of the extracts were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on THP-1 cell line. The antimycobacterial compounds were isolated and purified using bioassay-guided assay incorporated with column chromatography and preparative TLC. The isolated compounds were analysed and identified using nuclear magnetic resonance spectroscopy (NMR). The results obtained in this study showed that water was the best extractant, extracting 57.6 mg of the plant material, followed by methanol with 38.1 mg and hexane as the least extractant with 12.4 mg. In the phytochemical analysis of TLC plates, there was a separation of compounds in all the mobile systems, and a clear separation of compounds was observed in the BEA mobile system, followed by the EMW system. The plant has all major phytochemicals that are needed for drug development. The plant extracts had antioxidant activity, which was confirmed by the quantitative assays. The high inhibitory activity of the extracts was indicated by low MIC values that inhibited the bacterial growth. The butanol extract had the lowest MIC value (0.13 mg/mL). The plant extracts were able to prevent the formation of biofilm at different concentrations. The plant was proven to have anti-inflammatory properties by having a high inhibition capacity to prevent protein denaturation. The cytotoxicity results showed that the plant was toxic to the cells. The isolated antimycobacterial compounds were identified as Eicosanoic acid and Docosanoic. They have moderate activity with the MIC value of 0.25 mg/mL. The study indicated that the isolated compounds have antimycobacterial activity, which showed that the plant has a potential to treat TB or symptoms related to TB. However, further studies are needed to evaluate their toxic effects before use. / The National Research Foundation (NRF)

Mature field-grown apple trees were used to gain a better understanding of the influences of light and fruit on leaf physiology. Light effects on net photosynthesis (Pn), specific leaf weight (SLW), leaf N content (Weight/area) (Nw), and leaf N concentration (% dry weight) (Np) of spur leaves from two canopy locations were evaluated on four dates in 1987. Interior leaves had lower Pn, SLW, Nw, and Np than exterior leaves. In 1988 the influence of %available photosynthetic photon flux (PPF) on the same parameters was examined throughout the season. On most measurement dates both Pn and SLW increased quadratically while Nw increased linearly with increasing PPF. In both years positive linear relationships existed between Pn and Nw, SLW and Nw, and Pn and SLW. / Ph. D.

Several experiments were conducted to determine: the influence of canopy position, girdling, and defoliation on nectar production; whether instantaneous light measurements yield reliable estimates of cumulative seasonal light levels within the canopy; and the effect of the canopy light environment on spur leaf physiology and fruit quality. Defoliation of nongirdled flowering spurs had no effect on nectar production or composition, while defoliation of girdled spurs induced nectar sugar concentration by 24%. Canopy position had no influence on nectar production or composition. At full bloom there were differences in photosynthetic potential of spur leaves from different canopy positions. Exterior leaves had a greater maximum photosynthetic rate and an unique photosynthetic light response curve compared to the intermediate and interior leaves. Differences among positions persisted throughout the season. Stomatal conductance, specific leaf weight, dark respiration, and light levels were greater for the exterior leaves throughout the season. Instantaneous light measurements made on a single uniformly overcast day after the canopy was fully-developed (average of four times during the day) provided reliable estimates (predictive R2 > 0.90, n = 30) of total cumulative seasonal photosynthetic photon density (PPD). There was a I-to-l relationship between instantaneous and cumulative PPD after canopy development was complete providing both measures were expressed as a percentage. The relationships were equal over multiple dates for two consecutive years. Cloudless conditions provided poor estimates (predictive R2 = 0.49 to 0.80, n = 30). Light environment and harvest date influenced fruit quality characteristics within the canopy. Fruit red color, intensity of red color, and soluble solids concentration were all positively related to light level, with the highest R 2 on the early harvest dates. Fruit weight, firmness, length/ diameter ratio, starch index, and seed number were not consistently influenced by the light environment. The number of hours above an average photosynthetic photon flux density threshold of 250 I-£mol. m-2• sec'! explained slightly more of the variation in fruit quality characteristics than any other expressions of light. / Ph. D.

Microbial respiration on sticks and leaves, measured as oxygen uptake rate, was compared among four (2nd-4th order) sites along an elevational gradient at Coweeta Hydrologic Laboratory, North Carolina. Rhododendron and birch leaves were placed in mesh bags in the stream at each site on 21 Oct 90. Oxygen uptake rates were measured for both leaf species beginning 15 Dec 90 and continuing monthly until leaves were no longer intact (birch-2 months, rhododendron-7 months). Microbial oxygen uptake rates were also measured monthly for one year on qualitative collections of sticks (1-3 cm diameter) found in the stream at each site. Oxygen uptake rates (mg O₂/hr) were calculated on both a surface area and AFDM basis. Overall mean respiration rate per unit surface area was highest for sticks, followed by rhododendron, and birch. When expressed on an AFDM basis, respiration rates were highest for birch, followed by rhododendron, and sticks. Based on continuous measurements, mean monthly stream temperatures were significantly different among sites, but mean incubation temperatures were not significantly different among sites, Respiration rates were significantly correlated with temperature for both rhododendron leaves and sticks on both an AFDM and surface area basis. Respiration rates on rhododendron also increased with exposure time. Results indicate that differences in respiration rates among sites, for both rhododendron leaves and sticks, can be explained primarily by changes in temperature. Additionally, the high respiration rates per unit surface area on sticks indicate that small woody debris may play a significant role as a substrate for microbial metabolism. / Master of Science