In this mini-dissertation the writer analyzed Hubert du Plessis’ Drie Stukke vir Fluit en Klavier, opus 25. He researched why Du Plessis uses three shorter series of different lengths. The ...relationship between the series in this work was researched, as well as the characteristic applications of the series. It was found that Du Plessis uses shorter series of different lengths as his compositional tool, because they are manageable and can be manipulated for any specific requirement or need. With fewer notes in a series, if chromatic notes are avoided, the music will lean itself to an impression of tonality. It is interesting for the researcher how the feeling of tonality was portrayed through the use of different series and hence the given dissertation was researched. In true atonal music, composers usually disregard third and halftone intervals. Yet, tritones are often used in atonal music. In retrospect, Du Plessis uses more third and halftone intervals than tritones. There is only one tritone in this work (found in the second series), as opposed to the use of third and halftone intervals throughout all three series. The feeling of tonality is further enhanced through fragments of the series that one can place in a specific key. With this in mind, it is evident to get the impression of tonality as a result of fragmentation from the series. Another aspect of tonality that cannot be ignored was the composer’s use of bitonality. The serial techniques that Du Plessis used, was also researched. It was found that Du Plessis did not make use of any new innovations. All these techniques were already used by composers like Schoenberg, Berg, Webern and Dallapiccola. The most important techniques that Du Plessis used, were:
The use of all the forms of the series and their transpositions
Overlapping series (that is when the last note of the series, becomes the first note of the next series)
Combination of series (superimposition)
The dividing of series between the instruments
The repetition of notes in a series before all the notes have been used
Sometimes notes are put in a different order, thereby losing the correct order of the series.
Dissertation (MMus)--University of Pretoria, 2008.
Music
unrestricted
Patients from developing countries who require heart valve surgery are younger and have less access to open heart surgery than those from developed countries. Transcatheter heart valves (THVs) may be ...an alternative but are currently unsuitable for young patients because of their inadequate durability. We developed and tested a THV utilizing two new types of decellularized bovine pericardial leaflets in an ovine model.
The two decellularized tissues one with a very low dose (0.05%) of monomeric glutaraldehyde (GA) fixation and detoxification (DF) and the other without glutaraldehyde (DE) were compared to an industry standard Glycar-fixed with the standard dose (0.625%) of glutaraldehyde. THVs were manufactured with the three tissue types and implanted in the pulmonary position of nine juvenile sheep for 180 days. Baseline and post-explantation evaluations were performed to determine the hemodynamic performance of the valves and their dynamic strength, structure, biological interaction, and calcification.
Heart failure occurred in one animal due to incompetence of its Glycar valve, and the animal was euthanized at 158 days. The gradients over the Glycar valves were higher at the explant than at the implant, but the DE and DF valves maintained normal hemodynamic performance throughout the study. The DF and DE tissues performed well during the mechanical testing of explanted leaflets. Glycar tissue developed thick pannus and calcification. Compared to Glycar, the DF tissue exhibited reduced pannus overgrowth and calcification and the DE tissue exhibited no pannus formation and calcification. All tissues were endothelialized adequately. There was a striking absence of host ingrowth in the DE tissue leaflets, yet these leaflets maintained integrity and mechanical function.
In the juvenile sheep THV model, Glycar tissue developed significant pannus, calcification, and hemodynamic deterioration. Using a very low dose of monomeric GA to fix the decellularized bovine pericardium yielded less pannus formation, less calcification, and better hemodynamic function. We postulate that the limited pannus formation in the DF group results from GA. Bovine pericardium decellularized with our proprietary method resulted in inert tissue, which is a unique finding. These results justify further development and evaluation of the two decellularized tissue types in THVs for use in younger patients.
Objectives During Candida albicans infection, arachidonic acid (AA) is released from phospholipids of infected host cell membranes and used by C. albicans as the sole carbon source and for production ...of eicosanoids. AA can be incorporated into the phospholipids of yeasts, influencing the saturation level and fluidity of yeast cell membranes. It is suggested that the effectiveness of polyene (e.g. amphotericin B) and imidazole (e.g. clotrimazole) antifungals may depend upon the level of unsaturation and ergosterol in the membrane. Therefore, the aim of this study was to evaluate the effect of AA on the cell membrane and susceptibility of C. albicans and Candida dubliniensis biofilms towards amphotericin B and clotrimazole. Methods Both yeasts were grown in the presence and absence of AA and the effect of amphotericin B and clotrimazole was examined by confocal laser scanning microscopy, determination of mitochondrial metabolism, unsaturation index of the phospholipid fractions and ergosterol content of the membranes. Results AA had no effect on the viability of the cells in the biofilm; however, there was an increase in ergosterol levels as well as antifungal susceptibility of biofilms grown in the presence of AA. Conclusions AA influences phospholipid unsaturation and ergosterol content of both yeasts C. albicans and C. dublininensis, increasing susceptibility towards the antifungals. Pretreatment of biofilms with polyunsaturated fatty acids may result in the reduction in antifungal dose needed to inhibit biofilms.
Boza is a low-alcohol beverage produced from the fermentation of barley, oats, millet, maize, wheat or rice. The number of lactic acid bacteria isolated from three boza samples ranged from 9
×
10
6 ...to 5
×
10
7
CFU/mL. Carbohydrate fermentation reactions and PCR with species-specific primers classified the isolates as
Lactobacillus paracasei subsp.
paracasei,
Lactobacillus pentosus,
Lactobacillus plantarum,
Lactobacillus brevis,
Lactobacillus rhamnosus and
Lactobacillus fermentum. No filamentous fungi were isolated. Yeasts were isolated from two of the three boza samples, with cell numbers ranging from 1.3
×
10
2 to 1.8
×
10
3
CFU/mL. Results obtained from sequencing of the D1/D2 rDNA region identified the yeasts as
Candida diversa,
Candida inconspicua,
Candida pararugosa,
Issatchenkia orientalis,
Pichia fermentans,
Pichia guillliermondii,
Pichia norvegensis,
Rhodotorula mucilaginosa and
Torulaspora delbrueckii.
C. inconspicua has been isolated from human sputum and tongue and is an opportunistic pathogen.
R. mucilaginosa is also an opportunistic pathogen implicated in fungaemia, endocarditis and meningitis.
P. norvegensis has been associated with septicaemia in humans.
Saccharomyces cerevisiae, commonly associated with fermented beverages, has not been detected in any of the boza samples, despite enrichment.
Using immunofluorescence confocal laser scanning microscopy, immunogold transmission electron microscopy and gas chromatography - mass spectrometry, we demonstrated the presence of 3-hydroxy fatty ...acids in
Cryptococcus neoformans
. Our results suggest that these oxylipins accumulate in capsules where they are released as hydrophobic droplets through tubular protuberances into the surrounding medium.
In this paper we report the influence of acetylsalicylic acid on oxylipin migration in
Cryptococcus
neoformans
var. neoformans UOFS Y-1378, previously isolated from human bone lesion. Transmission ...electron microscopy suggests that osmiophilic material originates in mitochondria and is deposited inside the yeast cell wall, from which it is excreted into the environment, along capsule protuberances, or through capsule detachments. Previous studies using immunogold labeling indicate that these osmiophilic layers contain 3-hydroxy oxylipins. In this study, the addition of acetylsalicylic acid (an inhibitor of mitochondrial function) in increasing amounts to the cells abrogated the migration of osmiophilic material, as well as capsule detachment from cell walls, and hence, oxylipin excretion. Consequently, we hypothesize that 3-hydroxy oxylipins are produced in mitochondria, probably via incomplete β-oxidation or fatty acid synthesis, from which they are deposited inside the cell wall and excreted through tubular protuberances attached to the surrounding capsules and (or) through detachment of these oxylipin-containing capsules.
When oxylipin and mitochondrion probes, i.e., fluorescing antibodies specific for 3-hydroxy fatty acids (3-OH oxylipins) and rhodamine 123 (Rh123), were added to yeast cells, these probes accumulated ...mainly in the sexual cells (i.e., both associated with ascospores) and not in the vegetative cells. This suggests increased mitochondrial activity in asci, since 3-OH oxylipins are mitochondrially produced and it is known that Rh123 accumulates selectively in functional mitochondria that maintain a high transmembrane potential ( Δ Ψm). This increased activity may be necessary for the production and effective release of the many spores found in single-celled asci. These results may be useful in the rapid identification of asci and in yeast sexual spore mechanics, which may find application in yeast systematics as well as hydro-, aero-, and nano-technologies.
Using a well tested antibody specific for 3-hydroxy oxylipins, we mapped the presence of these oxylipins in selected
Cryptococcus
(
Filobasidiella
) species. Immunofluorescence microscopy studies ...revealed that these compounds are deposited on cell wall surfaces, appendages, and collarettes. In vitro studies revealed that growth of Cryptococcus species was inhibited by acetylsalicylic acid (which is known to inhibit mitochondrial function, including the production of 3-hydroxy oxylipins) at concentrations as low as 1 mmol/L. The results suggest that acetylsalicylic acid is effective in controlling the growth of tested pathogens, probably by targeting their mitochondria. This study further expands the known function of this anti-inflammatory drug as anti-fungal agent.
Immunofluorescence microscopy exposed the presence of novel 3-hydroxy oxylipins on the surfaces of aggregated hat-shaped ascospores of Ascoidea africana. These compounds were confirmed by gas ...chromatography - mass spectrometry analysis. Only the complete structure of a novel 3-hydroxy 10:1 could be determined.Key words: Ascoidea africana, ascospore, 3-hydroxy oxylipins, immunofluorescence microscopy, yeast.
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