Showing papers by "University of the Free State published in 1987"
TL;DR: Equus Cave, in Quaternary tufa near Taung in the semiarid woodland of the southern Kalahari, yielded 2.5 m of sediment in which a rich assemblage of bones and coprolites was preserved.
125 citations
TL;DR: The elevation of the base of glacial deposits, areas where glaciated bedrock is overlapped by post-glacial sediments, palaeoice-flow directions, thickness of the glacial sequence and the lithology (lithofacies and clast composition) were used as integrated parameters to reconstruct the Permo-Carboniferous glaciated land surface over southern Africa as mentioned in this paper.
120 citations
TL;DR: The effect of different ethanol concentrations on the growth of Candida shehatae and Pichia stipitis with xylose as substrate was evaluated in a temperature gradient incubator.
Abstract: The effect of different ethanol concentrations on the growth of Candida shehatae and Pichia stipitis with xylose as substrate was evaluated in a temperature gradient incubator. The upper limit of the temperature profiles of ethanol tolerance of both yeast strains were similar, although P. stipitis appeared to have a slightly higher ethanol tolerance in the higher temperature range. An increase in the ethanol concentration severely depressed the maximum growth temperature, and also increased the minimum growth temperature slightly. The ethanol tolerance limit of 46–48 g·l-1 occurred within a narrow temperature plateau of 11 to 22° C. The low ethanol tolerance of these pentose fermenting yeasts is detrimental for commercial ethanol production from hemicellulose hydrolysates.
82 citations
TL;DR: In the heartwood of P soyauxii, a pterocarpan, 8-hydroxy-3,9-dimethoxy- and 3,8-dihydroxy-9-methoxypterocarminocarpans and a new santal analogue were isolated from the root of P marsupium by means of high resolution NMR techniques as discussed by the authors.
60 citations
TL;DR: Oral immunotherapy with grass‐maize pollen extract in grass pollen‐sensitive seasonal hay fever patients is safe and effective, and both groups had markedly milder symptoms compared with the placebo group.
Abstract: Summary
Forty patients with a well-documented history of seasonal hay fever and a positive skin-prick test specific to grass pollen, including Bermuda grass and maize pollen (Zea maize), were allocated randomly on a double-blind basis to receive either an oral mixed grass–maize pollen extract or a matched placebo during the 1981/1982 grass pollen season. After 12 months the code was broken and patients on placebo were transferred to active therapy while patients on active therapy continued with maintenance therapy for another 12 months during the 1982/1983 grass pollen season. The assessment of the effect of the orally administered grass–maize pollen extract was on the clinical symptoms. During the first year the patients on active therapy had significantly fewer hay fever symptoms during the summer months compared with the placebo group. During the second study year, with all patients on active therapy, both groups had markedly milder symptoms compared with the placebo group. Side–effects were negligible. This study concludes that oral immunotherapy with grass-maize pollen extract in grass pollen-sensitive seasonal hay fever patients is safe and effective.
53 citations
TL;DR: In this article, the reaction proceeds through two competing rate determining steps, one of which is first-order in [CH 3 I], and a reaction mechanism, which includes specific solvent effects, is given.
50 citations
TL;DR: Pollen spectra in a peat deposit from a mountainous area near Tate Vondo in Venda have been grouped into three zones. as mentioned in this paper showed that the vegetation on slopes was open, but that forests were well developed in mountain ravines.
50 citations
TL;DR: A new species of Fusarium is described based on single-conidial cultures grown on potato dextrose agar (PDA) (5), carnation leaf Agar (CLA) (2), and KCI medium (3), which has some characters similar to species in section Liseola.
Abstract: (1987). Fusarium Napiforme, A New Species from Millet and Sorghum in Southern Africa. Mycologia: Vol. 79, No. 6, pp. 910-914.
48 citations
TL;DR: The estimation of plasma PLP alone does not permit an accurate assessment or understanding of the nutritional status and the physiology of vitamin B-6 in conditions associated with altered vitamin B -6 homeostases, and it may serve as a readily available source of vitaminB-6 to meet possible increased metabolic demands.
Abstract: Plasma pyridoxal-5'-phosphate (PLP) concentration has been suggested as a valid indicator to assess vitamin B-6 nutritional status. Animal and human studies have shown that plasma PLP concentrations decrease progressively during pregnancy and large doses of vitamin B-6 supplementation are required to maintain plasma PLP at early or prepregnant levels. PLP is known to be hydrolyzed to pyridoxal (PL) by alkaline phosphatase (ALP), resulting in an inverse relationship between PLP and ALP. The object of this study was to compare the PLP-PL equilibrium in a group of healthy pregnant females with that of an age-matched nonpregnant control group from a similar socioeconomic background. The mean plasma PLP level was 37% lower, (P less than 0.0001), whereas the mean PL level was almost 90% higher (P less than 0.001) in the pregnant group than in the nonpregnant control group. The total amount of plasma PLP and PL levels, however, did not differ significantly (P greater than 0.24) between the two groups. Because the PL vitamer is regarded as the ultimate transport form of vitamin B-6, it may serve as a readily available source of vitamin B-6 to meet possible increased metabolic demands. Therefore, the estimation of plasma PLP alone does not permit an accurate assessment or understanding of the nutritional status and the physiology of vitamin B-6 in conditions associated with altered vitamin B-6 homeostases.
41 citations
TL;DR: In this paper, a novel bioside, β-(3′,4′-dihydroxyphenyl)ethyl-O -α-L -rhamnopyranosyl(1 → 3)-D-glucopyranoide, was obtained from the secondary roots of Harpagophytum procumbens.
41 citations
TL;DR: In this paper, the authors investigated the usefulness of the core-break technique for evaluating root density of four plant species in two soil types and encountered several problems, but recommend the core break method to researchers who wish to quantify root development rapidly under various soil tillage practices.
Abstract: Most of the methods available for plant rooting studies in field soil are very tedious and time-consuming. Several investigations have shown that the core-break technique, in which roots are counted that appear at the faces of a broken core of soil, provides acceptable estimates of root length density in some situations. We investigated the usefulness of the core-break technique for evaluating rooting density of four plant species in two soil types. We encountered several problems, but recommend the core-break method to researchers who wish to quantify root development rapidly under various soil tillage practices.
TL;DR: The rate of development, fecundity and lifespan of apterae of Diuraphis noxia (Mordvilko) were determined at five sets of temperature and daylength conditions.
Abstract: The rate of development, fecundity and lifespan of apterae of Diuraphis noxia (Mordvilko) were determined at five sets of temperature and daylength conditions. The time required to complete pre-imaginal growth at mean daily temperatures of 10, 13, 14, 17·25 and 20°C was 19·70, 12·09, 11·25, 9·88 and 8·17 days, respectively. The threshold for development was estimated to be 0·54°C and the number of day-degrees C required to complete development was 158·73.
TL;DR: The finding of low plasma pyridoxal-5'-phosphate levels in patients suffering from myocardial infarction does not support the contention that vitamin B6 deficiency may be a risk index for ischaemic heart disease.
TL;DR: In this article, a 4-methoxy-2′,4′-dimethoxymethyl-(E)-chalcone with H2O2 in the presence of poly-α-aminoacid catalysts afforded chiral aromatic oxygenated chalcone epoxides.
TL;DR: It is proposed that decreased lymphocyte beta-adrenoceptor Bmax values may be used as a biological marker for major depressive disorder.
Abstract: 3 H-Dyhydroalprenolol binding to lymphocyte membranes of patients with primary, unipolar major depressive disorder was compared to that of a normal, healthy control population. No significant difference could be demonstrated between the K d values of the two different groups, but the B max values of the depressed patients were significantly lower than those of the controls. Positive correlations were observed between the lymphocyte β-adrenoceptor B max values of the patients and their Beck self-evaluation and Hamilton depression ratings. We propose that decreased lymphocyte β-adrenoceptor B max values may be used as a biological marker for major depressive disorder.
TL;DR: Results indicate that the majority of L. oenos strains included in this study are closely related, but more research is needed to justify the separation of these strains into more than one species.
Abstract: Phenotypic data of 108 tests conducted on 70 malolactic bacteria, including 54 presumptive Leuconostoc oenos strains, five presumptive pediococci isolated from wine and 11 reference strains, were analysed by numerical taxonomic techniques. Using the simple matching coefficient, 58 strains were grouped in six clusters at the 87% S level. Cell wall analysis of the interpeptide bridges and morphology was also used to differentiate between the strains. No L. oenos reference strains were found to group in any cluster. The hypothetical median organism (HMO) of cluster A was related at only the 63% S level to the L. oenos type strain and it is proposed that these strains be regarded as ‘L. gracile’. The majority of the L. oenos strains (35) grouped together at above the 91% S level in cluster B, with the HMO of this cluster related at the 75% S level to the L. oenos type strain. Results indicate that the majority of L. oenos strains included in this study are closely related, but more research is needed to justify the separation of these strains into more than one species.
TL;DR: Levels of fructose 2,6-P(2) and PPi in the seeds are sufficient to activate PFP and thereby enable a glycolytic role for PFP during germination, however, the fructose 6-P content appears to be well below the K(m) of PFP for this compound and would therefore preferentially bind to the catalytic site of PFK, which has a lower K( m) for fructose 7-P.
Abstract: THE DISTRIBUTION OF PYROPHOSPHATE: fructose 6-phosphate phosphotransferase (PFP) and ATP: fructose-6-phosphate 1-phosphotransferase (PFK) was studied in germinating bean (Phaseolus vulgaris cv Top Crop) seeds. In the cotyledons the PFP activity was comparable with that of PFK. However, in the plumule and radicle plus hypocotyl, PFP activity exceeds that of PFK. Approximately 70 to 90%, depending on the stage of germination, of the total PFP and PFK activities were present in the cotyledons. Highest specific activity of both enzymes, however, occurred in the radicle plus hypocotyl (64-90 nanomoles.min.milligram protein). Fractionation studies indicate that 40% of the total PFK activity was associated with the plastids while PFP is apparently confined to the cytoplasm. The cytosolic isozyme of PFK exhibits hyperbolic kinetics with respect to fructose 6-P and ATP with K(m) values of 320 and 46 micromolar, respectively. PFP also exhibits hyperbolic kinetics both in the presence and absence of the activator fructose-2,6-P(2). The activation is caused by lowering the K(m) for fructose 6-P from 18 to 1.1 millimolar and that for pyrophosphate (PPi) from 40 to 25 micromolar, respectively. Levels of fructose 2,6-P(2) and PPi in the seeds are sufficient to activate PFP and thereby enable a glycolytic role for PFP during germination. However, the fructose 6-P content appears to be well below the K(m) of PFP for this compound and would therefore preferentially bind to the catalytic site of PFK, which has a lower K(m) for fructose 6-P. The ATP content appears to be at saturating levels for PFK.
TL;DR: Digitaria eriantha and Digitaria argyrograpta were the most sensitive to moisture stress, whereas Sporobolus fimbriatus and Panicum stapfianum were last to show signs of wilting.
Abstract: A number of grasses were ranked according to the order in which they wilted with diminishing moisture availability, and according to their ability to recover after water replenishment. Digitaria eriantha and Digitaria argyrograpta were the most sensitive to moisture stress, whereas Sporobolus fimbriatus and Panicum stapfianum were last to show signs of wilting. The latter two grass species were the first to recover from wilting during optimum soil water conditions. The leaf water potential and soil water content at which each grass species wilted were recorded.
TL;DR: Seasonal changes in nutrient standing stocks in the vegetation of the mire-grasslands are in the upper part of the range reported for sub-Arctic and Arctic graminoid communities, and low Ca concentrations occur in the plants so that Ca standing stocks are lower than in most comparable northern hemisphere communities.
Abstract: Investigations of the seasonal changes in vegetation standing crop have enabled an assessment of annual net primary production (ANP) at a fjaeldmark, open fernbrake and closed fernbrake at Marion Island (46°54′S, 37°45′E). These communities represent a successional sequence on relatively dry ridges and slopes on the island. Together, they are representative of a large proportion of the island's lowland (c. 300 m above sea level) vegetation. Aboveground ANP's were 728 g m-2 y-1 at closed fernbrake, 502 g m-2 y-1 at open fernbrake and 226 g m-2 y-1 at fjaeldmark. Total (above-plus below) ANP's were 1958 g m-2 y-1, 1578 g m-2 y-1 and 685 g m-2 y-1, respectively. These values are greater than those found for most tundra and tundra-like shrub and dwarf shrub-dominated communities of the northern hemisphere. The island's oceanic climate ensures a long growing season (c. 300 days for vascular plants, 365 days for bryophytes) and aboveground productivities for the island communities (including two mire-grasslands reported on previously), based on the length of the growing season, were 0.9 to 2.9 g m-2 d-1, lower than for most comparable shrub and dwarf shrub sub-Arctic or alpine communities and more similar to low Artic and low alpine sedge-moss and grass-herb communities. Production efficiencies (0.7% to 2.1% of photosynthetically active radiation) were in the range reported for northern hemisphere subpolar vegetations.
TL;DR: The cellular long-chain fatty acid compositions of 104 yeast strains representing 39 species associated with the wine industry were determined by gas-liquid chromatography resulting in identification within three days which compares favourably with the seven to ten days and longer required for conventional methods.
TL;DR: Nouvelles courbes de lumiere UBV et spectroscopie a dispersion moyenne de cette binaire. Les masses, rayons, et temperatures des 2 composantes sont presque identiques as discussed by the authors.
Abstract: Nouvelles courbes de lumiere UBV et spectroscopie a dispersion moyenne de cette binaire. Les masses, rayons, et temperatures des 2 composantes sont presque identiques
TL;DR: The mean peak concentration and half-life of Hoe 498 in serum are slightly higher in the elderly than in younger volunteers, and the mean recovery of HOE 498 and metabolites in urine, up to 26 hours after administration, was 35 +/- 14% of the dose.
Abstract: Ramipril (HOE 498) is a pro-drug of which the main metabolite (HOE 498 diacid or ramiprilat) is a potent angiotensin converting enzyme inhibitor. Thirteen healthy white volunteers (5 females and 8 males, ages 65 to 76 years) participated in a study to investigate the pharmacokinetics of HOE 498 in the elderly. After administration of 10 mg of HOE 498, sequential urine and serum specimens were obtained for assay of HOE 498 and metabolites (HOE 498-glucuronide, diacid, diacid-glucuronide, diketopiperazine and diketopiperazine acid). Side effects, clinical chemistry and hematology were monitored. HOE 498 reached peak concentrations of 62.4 +/- 23.3 ng/ml in serum after 0.7 +/- 0.3 hours. Serum levels decreased with an apparent half-life of 0.9 +/- 0.4 hours. The diacid was rapidly formed in serum, reaching peak concentrations of 40.6 +/- 14.0 ng/ml after 2.0 +/- 0.6 hours and declining with a half-life of 2.2 +/- 0.5 hours. A prolonged terminal phase of serum concentration versus time curve was observed at concentrations less than 1 ng/ml. The mean recovery of HOE 498 and metabolites in urine, up to 26 hours after administration, was 35 +/- 14% of the dose. The apparent half-lives, calculated from urine parameters, for HOE 498 and the diacid were 2.6 +/- 0.9 and 4.0 +/- 1.1 hours, respectively. The mean peak concentration and half-life of HOE 498 in serum are slightly higher in the elderly than in younger volunteers. Complete urinary collection was not possible, but urinary recovery did not seem different from younger volunteers.
Journal Article•
TL;DR: It is concluded that forskolin reduces intra-ocular pressure in healthy volunteers, and that oxybuprocaine reduces IOP in its own right.
Abstract: Two studies were performed to investigate the effects of forskolin (Hoechst Research) on intra-ocular pressure (IOP). In the first study two 1.0% formulations of forskolin eye drops were compared with placebo in 10 healthy volunteers. Oxybuprocaine eye drops were used for local anaesthesia before measurement of IOP by applanation tonometry. This was followed by instillation of either medication or placebo on a randomised cross-over basis and hourly measurement of IOP. No significant differences were present between the forskolin treatments and placebo. For 6 hours after drug application a definite decrease in IOP relative to base-line values was observed after each of the forskolin treatments as well as after placebo. In a subsequent study only one formulation of 1% forskolin was compared with placebo. Proxymetacaine eye drops were used for local anaesthesia. Forskolin resulted in a significant reduction in IOP relative to placebo. It is concluded that forskolin reduces IOP in healthy volunteers, and that oxybuprocaine reduces IOP in its own right.
TL;DR: In this article, the authors considered six island or island groups (Marion and Prince Edwards Islands, Iles Crozet and Iles Kerguelen, Heard and McDonald Islands, Macquarie Island, South Georgia) to belong to the sub-Antarctic region and described the environments and biota of these islands.
TL;DR: In this article, a triclinic space group P 1 with a = 8.820(3), b = 10.812(2), c = 13.569(3) A, α = 67.41(2)°, β = 72.90-2 )°, and γ = 85.48° was determined from 2811 observed reflections.
Journal Article•
TL;DR: In the early 1940's, the Nationalist Party as discussed by the authors proposed a draft constitution for a future republic with Afrikaans as the first official language and English as a supplementary official language.
Abstract: Afrikaner nationalism and English: a brief policy deviation and its background. Afrikaner nationalism -of which the Nationalist Party was the most important exponent -has an impeccable record in one respect. During the reign of that party the language rights of the English-speaking population were never curtailed; neither was it the policy of the party as opposition party to do so. An exception occurred in the early 1940's. A few organisations such as the Ossewa-Brandwag were in favour of Afrikaans as first official language (and English as second language). In 1942 the Nationalist Party announced a draft constitution for a future republic. The language provision in the draft read that as Afrikaans was the language of the original white inhabitants of the country, it would be the first official language. English was regarded as a second or supplementary official language which would be treated on a basis of equality and would enjoy equal freedom, rights and privileges with the official language in all situations where such treatment was deemed by the state authority to be in the best interests of the state and its citizens. This article was criticized by the most important N.P. mouthpiece, Die Burger, as well as Die Volksblad and Die Oosterlig, because it would be tantamount to injustice to the English-speaking sector. Within a few months the proposed language provision was repudiated by the party leader, Dr. D.F. Malan, and Transvaal leader, Mr. J.G. Strijdom. The article sketches the pro-Republican activities of the period, the pronouncements about official languages and the political and language background against which these pronouncements should be evaluated.
TL;DR: Methods for evaluating irrigation efficiency recognize the importance of managers' goals such as profit maximization and risk minimization as well as the impact of limited information on the attainment of these goals.
TL;DR: A statistically significant rising trend in the prevalence of renal stones in blacks, accompanied by changes in the ratios of the major stone forming constituents, have been a prominent feature of this survey, but the aforementioned remained unchanged in white patients.
Abstract: Summary— One thousand and two calculi, which occurred in both black and white patients during a 15-year period, have been analysed by the X-ray diffraction technique. Calcium oxalate calculi were the most common irrespective of race. Whewellite calculi were equally distributed in both race groups, while weddelite stones appeared to be much less common amongst blacks; the opposite applied for struvite and the rare ammonium acid urate stones. The other calculi were approximately equally distributed between the two race groups. A statistically significant rising trend in the prevalence of renal stones in blacks, accompanied by changes in the ratios of the major stone forming constituents, have been a prominent feature of this survey. However, the aforementioned remained unchanged in white patients. Contrary to previous impressions, total urates exceed phosphates in whites as a major stone forming constituent. The composition of upper urinary tract stones in blacks, during the 3-year period 1981 to 1983, was very similar to the composition previously reported for the Sudanese.
The profile of renal stones in blacks over the last 3 years, however, is now becoming substantially different from that of the other previously reported surveys and may be approaching that of their white compatriots. A change in the dietary patterns in blacks is occurring which is also reflected in an increasing incidence of ischaemic heart disease and which may also be responsible for the observed changes in renal stones.
TL;DR: The chromosomal DNA band patterns for nine strains representing four species of the genus Saccharomyces were determined by an optimized orthogonal-field-alteration gel electrophoresis (OFAGE) method and each of the four species proved to be unique.