Excerpt: Tinnitus: Clinical and Research Perspectives summarizes contemporary findings from basic and clinical research regarding tinnitus mechanisms, effects, and interventions. The text features a collection of international authors, active researchers, and clinicians who provide an expansive scope of material that ensures relevance for patients and professionals. Reviews and reports of contemporary research findings underscore the text s value for classroom use in audiology and otolaryngology programs. Patients and students of audiology will benefit from the text s coverage of tinnitus mechanisms, emerging practice considerations, and expectations for outcomes--for example, recent successes of cognitive behavioral therapy, neuromodulation, and hearing aid use. These and other topics, such as the effects of noise and drugs on tinnitus, are reported in a way that enhances clinicians ability to weave such strategies into their own work. The influence of tinnitus on all aspects of life is explored, from art to medicine and communication to isolation, thereby providing clinicians and patients a deeper understanding of and greater facility managing a tinnitus experience. Finally, this text includes case studies that provide a practical view of tinnitus effects and management approaches. The editors hope that the consideration of mechanisms, interventions, and outcomes resonates with patients, clinicians, and students of audiology.

[Truncated abstract] Traditional medicines are used by millions of people throughout the world as their primary source of medical care. A range of materials are in used traditional medicines including plant and animal parts. Even though the traditional medicine trade is estimated to be worth sixty billion dollars annually the trade remains largely unregulated. Unscrupulous practices by vendors to increase their profit margins such as substituting and adulterating expensive material with cheaper varieties go unchecked. This can be dangerous to consumers because some substitutions involve poisonous material. Also, animal parts from endangered species can find their way into traditional medicines, therefore there needs to be a way to identify them in traditional medicines to prosecute poachers. The traditional techniques used for the identification of material used in Traditional Chinese Medicine (TCM) include, morphological, histological, chemical and immunological analysis. However, these techniques have their limitations. This makes applying multiple techniques essential to provide thorough authentication of the material. DNA profiling provides a technique well suited to analysing material used in TCM. DNA profiling is advantageous over other techniques used to authenticate material used in TCM because it requires only a small sample amount, can determine the cultivator, be used on all forms of TCM and potentially distinguish the components of mixtures. ... Therefore, profiles of different species/individual are different and species? can be distinguished. Commercially sold traditional medicines are processed which is likely to degrade the DNA of the sample making extraction and amplification difficult. Here an organic Phenol:Chloroform extraction technique extracted DNA from commercial dried root samples. The extracted DNA was amplifiable using RAPD primers. The RAPD primers used here produced enough polymorphic bands to distinguish different plant species. They were used to distinguish commercial samples that were sold as three different species within the Panax genus, Panax ginseng, Panax quinquefolium and Panax notoginseng and genetically unrelated plant material; Potato and Eleutherococcus senticosus. Liquid samples and mixtures were also profiled with the RAPD primers to determine whether the RAPD primers provide enough distinguishing ability to analyse these forms of TCM. DNA was extracted from the liquid samples, one a ginseng drink and the other an ginseng extractum. However, there was no reliability in the production of PCR products. The analysis of the mixture samples found that not enough polymorphic bands were produced by the RAPD primers used here to identify Panax species within mixtures of two Panax species. While when P. ginseng was mixed with a genetically unrelated sample there was enough polymorphism to differentiate the two samples in the mixture. The results of this research show that RAPD analysis provides a simple and inexpensive technique to begin analysis of materials used in TCM. Using RAPD analysis it is possible to distinguish Panax plant species from each other. However, the RAPD primers used here did not provide enough reproducibility or polymorphism to analyse liquid and mixtures of Panax species plants.

Surface plasmon-polaritons are optical surface waves formed through the interaction of photons with free electrons at the surface of metals. They offer interesting applications in a broad range of scientific fields such as physics, chemistry, biology, and material science. However, many of such applications face limitations imposed by the high propagation losses of these waves at visible and near-infrared wavelengths, which result mainly from power dissipation in the metal. In principle, the propagation losses of surface plasmon-polaritons can be compensated through optical amplification. The objective of this thesis is to provide deeper insights on the physics of surface plasmon-polariton amplification and spontaneous emission in surface plasmon-polariton amplifiers through theoretical and experimental vehicles applied (but not necessarily restricted) to a particular plasmonic mode termed long-range surface plasmon-polariton. On the theoretical side, the objective is approached by developing a realistic theoretical model to describe the small-signal amplification of surface plasmon-polaritons in planar structures incorporating dipolar gain media such as organic dye molecules, rare-earth ions, and quantum dots. This model takes into account the inhomogeneous gain distribution formed near the metal surface due to a non-uniform excitation of dipoles and due to a position-dependent excited-state dipole lifetime that results from near-field interactions between the excited dipoles and the metal. Also, a theoretical model to describe the amplified spontaneous emission of surface plasmon-polaritons supported by planar metallic structures is developed. This model takes into account the different energy decay channels into which an exited dipole located in the vicinity of the metal can relax. The validity of this model is confirmed through experimentation. On the experimental side, the objective is approached by providing a direct experimental demonstration of complete loss compensation in a plasmonic waveguide. The experiments are conducted using the long-range surface plasmon-polariton supported by a symmetric thin gold waveguide incorporating optically pumped organic dye molecules in solution as the gain medium. Also, an experimental study of spontaneous emission in a long-range surface plasmon-polariton amplifier is presented. It is shown that this amplifier benefits from a low spontaneous emission into the amplified mode, which leads to an optical amplifier with low noise characteristics. The experimental setup and techniques are explained in detail.

Surface plasmon-polaritons are optical surface waves formed through the interaction of photons with free electrons at the surface of metals. They offer interesting applications in a broad range of scientific fields such as physics, chemistry, biology, and material science. However, many of such applications face limitations imposed by the high propagation losses of these waves at visible and near-infrared wavelengths, which result mainly from power dissipation in the metal. In principle, the propagation losses of surface plasmon-polaritons can be compensated through optical amplification. The objective of this thesis is to provide deeper insights on the physics of surface plasmon-polariton amplification and spontaneous emission in surface plasmon-polariton amplifiers through theoretical and experimental vehicles applied (but not necessarily restricted) to a particular plasmonic mode termed long-range surface plasmon-polariton. On the theoretical side, the objective is approached by developing a realistic theoretical model to describe the small-signal amplification of surface plasmon-polaritons in planar structures incorporating dipolar gain media such as organic dye molecules, rare-earth ions, and quantum dots. This model takes into account the inhomogeneous gain distribution formed near the metal surface due to a non-uniform excitation of dipoles and due to a position-dependent excited-state dipole lifetime that results from near-field interactions between the excited dipoles and the metal. Also, a theoretical model to describe the amplified spontaneous emission of surface plasmon-polaritons supported by planar metallic structures is developed. This model takes into account the different energy decay channels into which an exited dipole located in the vicinity of the metal can relax. The validity of this model is confirmed through experimentation. On the experimental side, the objective is approached by providing a direct experimental demonstration of complete loss compensation in a plasmonic waveguide. The experiments are conducted using the long-range surface plasmon-polariton supported by a symmetric thin gold waveguide incorporating optically pumped organic dye molecules in solution as the gain medium. Also, an experimental study of spontaneous emission in a long-range surface plasmon-polariton amplifier is presented. It is shown that this amplifier benefits from a low spontaneous emission into the amplified mode, which leads to an optical amplifier with low noise characteristics. The experimental setup and techniques are explained in detail.

In this study, we study the polarization dependence, gain property, and amplified spontaneous emission in Cr4+: YAG crystal fibers. Cr4+: YAG crystal has an ultra-wide bandwidth of 300 nm. Cr4+: YAG crystal fibers fabricated through laser heated pedestal growth technique are suitable for the applications of fiber amplifiers, fiber lasers, and broadband light sources. The experiment results showed that the polarization-dependent loss has a severe variation as the optical wavelength change. The maximum polarization-dependent loss was up to 18 dB. The main reason of such a large polarization-dependent loss is the combination of multimode interference and the birefringence induced by the non-uniformity of optical waveguide structure and residue strain in Cr4+: YAG crystal fibers. Thus, the results of polarization-dependent loss can be used as a feedback parameter to improve the fabrication process. In the experiment of gain property, bi-directional pump and double-pass transmission scheme was adopted and a 0.2 dB net gain was obtained for the first time at signal wavelength of 1400 nm, pumping wavelength of 1060 nm, and total pumping power of 2.8 W. It shows that Cr4+: YAG crystal fiber has potential to be developed as a broadband fiber amplifier. In the measurement of amplified spontaneous emission spectrum, a wide bandwidth of amplified spontaneous emission of 300 nm with total power of 50 £gWwas obtained at 0.2W pumping power condition. The coupling efficiencies from amplified spontaneous emission to single mode fibers and multimode fibers were 1.5 % and 9.9 %, respectively. This result reveals that it has potential to be developed as a broadband light source. To improve the optical properties of Cr4+: YAG crystal fiber in the future, improving the uniformity of optical fiber waveguide and reducing the residue strain in Cr4+: YAG crystal fiber may suppress the polarization-dependent loss; increasing the fiber length, decreasing the mode number, and employing a cladding pump technique with a well-distributed pump power in the crystal fiber to alleviate the excited state absorption may raise the gain performance and the amplified spontaneous emission power.

Recently, with the escalating demands for optical communications, the need for bandwidth in optical communication network has increased. The technology breakthrough in dry fiber fabrication opens the possibility for fiber bandwidth from 1.3 to 1.6 £gm. Cr4+:YAG double-clad crystal fiber (DCF) grown by the co-drawing laser-heated pedestal growth method has a strong spontaneous emission spectrum from 1.3 to 1.6 £gm. Such fiber is, therefore, eminently suitable for broadband optical amplifier, amplifier spontaneous emission (ASE) light source, tunable solid-state laser, and optical coherence tomography (OCT) applications. In this thesis, multilayer dielectric thin films were directly deposited by E-gun coating onto the end faces of the heterostructure Cr4+:YAG DCF. In this way we have successfully improved the extracted ASE power by the high reflection (HR) coatings. The backward ASE in the fiber reflected and propagates with gain through the fiber in the forward direction. In dual-pump scheme, as much as 1.7 mW power (DCF length is 9.5 cm) of collimated output ASE was achieved. The dual-pump scheme and HR thin films provided 1.6 time improvements of the ASE output power. For broadband optical amplifier in dual-pump and double-pass scheme, a 3.7-dB gross gain and a 0.7-dB net loss (DCF length is 8.7 cm) at 1.4-£gm signal wavelength have been successfully developed with HR coatings onto one of the Cr4+:YAG DCF end faces. In addition, we have successfully developed the Cr4+:YAG DCF fiber laser by direct HR coatings onto fiber end faces. A record-low threshold of 96 mW (DCF length is 1.6 cm) with a slope efficiency of 6.9% was achieved at room temperature. It is more than four times lower than any previously reported Cr4+:YAG lasers.

The Cape parrot (Poicephalus robustus) is South Africa's only endemic parrot. It has become increasingly rare in recent years, with fewer than 500 birds left in the wild, and is now regarded as endangered. Possible factors contributing to this rapid decline in numbers include habitat loss, food shortage, disease and illegal trafficking and trading in the species. Habitat loss and food shortage have been brought about by the rapid destruction of the yellowwood trees in the afromontane forests in South Africa and have played a role in reducing the population numbers. The Psittacine beak and feather disease virus (PBFDV) has also contributed to the loss of some individuals, however it is the illegal trafficking of this rare and valuable species that has become of great concern. As the Cape parrot is becoming increasingly rare and therefore highly sought after, its commercial value has multiplied to the extent that illegal black market trapping is on the rise. The industry involved in breeding and conservation of endangered bird species, has a need for the proper establishment of studbooks, containing all available information on captive as well as tagged birds. Most of the information found in studbooks is based on morphological attributes of individual birds. Although this is useful, there is a need to add molecular information in order for complete identification of individuals, particularly in a species threatened by illegal trading and theft. A preliminary analysis of the amount of variation present in the population of interest is therefore required so that appropriate methods and techniques can be developed to identify individual birds. A RAPD analysis was conducted to assess the amount of variation in the Cape parrot and lay the foundations for the establishment of individual identification in the species. Blood samples from 30 parrots, consisting of both related and unrelated individuals, were obtained from three separate locations: Amazona in Assagay, Rehoboth Farm in Dargle, as well as from the Eastern Cape. 15 random primers were selected and used to conduct a randomly amplified polymorphic DNA (RAPD) analysis. RAPDs are extremely useful in situations where relatively inexpensive first approximations of the genetic variation are needed, such as in rare and endangered species. After successful optimisation of the technique in the species, the 15 primers were screened for all 30 individuals and the individual DNA fingerprints, analysed. Clear, distinctive and reliable DNA fingerprints were obtained for all individuals however, it was interesting to note despite the analysis of 85 loci using the 15 primers almost identical DNA fingerprints were produced between the individual birds. A population analysis into the amount of variation present between and within the three populations, as well as for the representative population as a whole, was conducted. Using various statistical programmes such as POPGENE and ARLEQUIN, heterozygosities, genetic distance measures, diversity indices, Wright's fixation index and AMOVAs were estimated. The amount of polymorphism detected in this investigation was 33 % and the heterozygosity, 0.37, which is a relatively high value for the uniformity displayed in the DNA profiles. The high GC content of the primers however, could be a possible explanation thereof. Relationship and kinship determination, sex determination as well as population assignment was possible despite not being able to identify each individual based on unique DNA fingerprints. The AMOVA analysis indicated significant variation on both the between (5.59 %) and within (94.41 %) levels of analysis. Little variation or differentiation was observed between the three subpopulations, which was confirmed with an FST value of 0.056. The variation experienced within each subpopulation was analysed using Shannon's index of phenotypic diversity. The Amazona population displayed the most variation with a value of 0.286 and the Rehoboth population, the least with 0.195. This was expected, with the individuals from the latter population comprising one extended family. Nei's measures of genetic identity revealed that the individuals from Amazona were more similar to the Eastern Cape population, which was again expected with regular exchanging of chicks between the two breeders. RAPD technology was successful in laying the foundations for individual identification in the Cape parrot. It was also successful in producing reproducible DNA fingerprints in the species that were able to determine relatedness to some extent, determine the sex of individuals and identify individuals from a particular subpopulation. Furthermore RAPD analysis gave a good indication of the variation found in the Cape parrot population, which is important for conservation purposes. In order to maximize conservation efforts and strategies in an endangered species, determining the level of genetic diversity and variation found in the remaining individuals of the population is of great importance. This information could provide powerful insight for conservation purposes and depending on the level of diversity detected, appropriate breeding programmes could be set up in order to increase the genetic variation and thereby reduce the chance of extinction of the species. The following important findings emerged from this investigation: • RAPD technology, once optimised for the species of interest, is successful in producing clear and reliable DNA fingerprints, provided the same protocol is followed carefully throughout the investigation. • An optimised protocol for fingerprinting the Cape parrot using RAPDs was established. • Possible sex identification, population assignment and a degree of kinship determination was determined using RAPDs. • Little variation was found within the representative Cape parrot population as a whole due to small population size and possible inbreeding. • As expected for an avian species, little genetic sub-division or differentiation was observed between the three populations analysed. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

No abstract available. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

A collection of 29 clinical streptococcal isolates obtained from the University of KwaZulu-Natal, Medical School, Durban Metro area (South Africa) were studied to establish their penicillin G susceptibility patterns often refered to as minimal inhibitory concentration (MIC) and to determine the genetic diversity among them using two genotyping methods, randomly amplified polymorphic DNA (RAPD) analysis and pulsed-field gel electrophoresis (PFGE) analysis. All isolates with MIC less than or equal to 0.12 µg/ml were considered susceptible, intermediate resistant if MIC was between 0.25 µg/ml and 4 µg/ml and resistant if greater than 4 µg/ml, The percentage of isolates with resistance was relatively high (75.9%), only 10.3% of isolates showed intermediate resistance and 13.8% of the isolates were completely susceptible to penicillin G. Some of the resistant isolates were highly resistant reaching penicillin G MIC levels of 5000 µ/ml. They were speculated to contain Path altered penicillin binding proteins and high level of crosslinking cell wall induced by the gene products of the MurMN operon. RAPD analysis was performed using three primers, MBPZ-1, MBPZ-2, and MBPZ-3, respectively. RAPD analysis allowed for the identification of 27 RAPD types with MBPZ-1 and MBPZ-3 and 26 RAPD types with MBPZ-2. Ninety-eight percent of these isolates were clustered into two groups, group I and group II, with 90% to 100% dissimilarity among them. Fifty two percent of the isolates of MBPZ-1 group I were in MBPZ-2 group I, 72% isolates of MBPZ-1 group I were in MBPZ-3 group I, and 72% of the isolates of MBPZ-2 group I were in MBPZ-3 group 1. This shows the discriminatory ability of the primers used in this study. Despite clustering of isolates, relatively high diversity was seen. PFGE analysis of macrorestriction fragments obtained after digestion of chromosomal DNA by restriction enzyme, SmaI showed 24 PFGE patterns. The 24 PFGE patterns were divided into three groups (I, II and III) of isolates, with an average of 85% dissimilarity (15% homology) among them. At 25% homology, four clusters, A (13 isolates), B (9 isolates), C (4 isolates), and D (4 isolates) were observed. Two pairs of isolates in group I, cluster A, showed 100% homology. This suggested that each represent the same strain. Four isolates of group I, cluster B, also exhibited 100% homology. This study showed that most of streptococcal isolates with the same penicillin G susceptibility patterns grouped together in a phylogenetic tree by both RAPD and PFGE analysis. There was also some similarity between the results obtained by RAPD analysis and PFGE analysis. Seventeen and nine of the 29 isolates grouped into group I and group II, respectively, two pairs of isolates were indistinguishable, and two pairs of islates were closely related by both RAPD (using MBPZ-3) and PFGE analysis. Although, RAPD analysis is sensitive, specific, faster and cost effective, the ease with which PFGE analysis can be performed, high discriminatory power, reproducibility of the results, and the polymorphism seen in the patterns, suggests that PFGE method has the potential to be very useful for epidemiological evaluations of nosocomial streptococcal infections in KwaZulu-Natal. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

Surface plasmon-polaritons are optical surface waves formed through the interaction of photons with free electrons at the surface of metals. They offer interesting applications in a broad range of scientific fields such as physics, chemistry, biology, and material science. However, many of such applications face limitations imposed by the high propagation losses of these waves at visible and near-infrared wavelengths, which result mainly from power dissipation in the metal. In principle, the propagation losses of surface plasmon-polaritons can be compensated through optical amplification. The objective of this thesis is to provide deeper insights on the physics of surface plasmon-polariton amplification and spontaneous emission in surface plasmon-polariton amplifiers through theoretical and experimental vehicles applied (but not necessarily restricted) to a particular plasmonic mode termed long-range surface plasmon-polariton. On the theoretical side, the objective is approached by developing a realistic theoretical model to describe the small-signal amplification of surface plasmon-polaritons in planar structures incorporating dipolar gain media such as organic dye molecules, rare-earth ions, and quantum dots. This model takes into account the inhomogeneous gain distribution formed near the metal surface due to a non-uniform excitation of dipoles and due to a position-dependent excited-state dipole lifetime that results from near-field interactions between the excited dipoles and the metal. Also, a theoretical model to describe the amplified spontaneous emission of surface plasmon-polaritons supported by planar metallic structures is developed. This model takes into account the different energy decay channels into which an exited dipole located in the vicinity of the metal can relax. The validity of this model is confirmed through experimentation. On the experimental side, the objective is approached by providing a direct experimental demonstration of complete loss compensation in a plasmonic waveguide. The experiments are conducted using the long-range surface plasmon-polariton supported by a symmetric thin gold waveguide incorporating optically pumped organic dye molecules in solution as the gain medium. Also, an experimental study of spontaneous emission in a long-range surface plasmon-polariton amplifier is presented. It is shown that this amplifier benefits from a low spontaneous emission into the amplified mode, which leads to an optical amplifier with low noise characteristics. The experimental setup and techniques are explained in detail.