Teachers frequently present with voice problems as result of functional voice hyperfunction and it seems that occupational duties often impede successful implementation of a conventional voice conservation strategies. The goal of this single-subject study was to investigate the practical value of personal voice amplification as an assistive option for teachers experiencing occupation-related voice problems The physical state of a teacher’s vocal chords and specific perceptual and acoustic attributes of her voice were evaluated before and after a period of conventional voice conservation, and also before and after a period during which personal voice amplification was used as an augmentative strategy. In the course of the study it was in the interest of the subject that a persistent vocal fold nodule be removed surgically. The research design was adapted accordingly and the study consequently included a pre- and post surgical phase. Physical examinations of the vocal cords reflected the positive effect of the surgical removal of a vocal fold nodule. An improvement in the general status of the vocal cords was also noted following periods during which personal voice amplification was used in combination with a conventional voice conservation strategy. Perceptual and acoustic analysis of voice quality confirmed the positive effect of the surgical intervention. Although a panel of judges did not detect an improvement in the subject’s voice quality following the assistive use of the personal amplifier, several acoustic voice parameters showed improvement or normalised after the use of personal voice amplification in combination with conventional voice conservation strategies. The subject’s repeated evaluation of her own voice experiences, as well as her view of the practicability of the two voice conservation strategies, revealed a remarkably positive attitude towards the augmentative use of personal voice amplification. The conclusion is that teachers who experience occupational voice problems could benefit from the use of personal voice amplification in combination with a conventional voice conservation strategy. / Dissertation (M (Communication Pathology))--University of Pretoria, 2006. / Speech-Language Pathology and Audiology / Unrestricted

Compromised calcium homeostasis in the central nervous system (CNS) is implicated as a major contributor in the pathology of neurodegeneration. Dysregulation of Ca2+ homeostasis initiates downstream Ca2+–dependent events that lead to apoptotic and/or necrotic cell death. Increases in the intracellular free calcium concentration ([Ca2+]i) may be the result of Ca2+ influx from the extracellular environment or Ca2+ release from intracellular Ca2+ stores such as the endoplasmic reticulum (ER). Influx from the extracellular environment is controlled predominantly by voltage gated calcium channels (VGCC), such as L–type calcium channels (LTCC) and ionotropic glutamate receptors, such as the N–methyl–D–aspartate (NMDA) receptors. Ca2+ release from the ER occurs through the inositol–1,4,5–triphosphate receptors (IP3Rs) or ryanodine receptors (RyRs) via IP3–induced or Ca2+–induced mechanisms. Mitigation of Ca2+ overload through these Ca2+ channels offers an opportunity for pharmacological interventions that may protect against neuronal death. In the present study the ability of a novel series of polycyclic compounds, both the pentacycloundecylamines and triquinylamines, to regulate calcium influx through LTCC was evaluated in PC12 cells using calcium imaging with Fura–2/AM in a fluorescence microplate reader. We were also able for the first time to determine IC50 values for these compounds as LTCC blockers. In addition, selected compounds were evaluated for their ability to offer protection in apoptosis–identifying assays such as the lactate dehydrogenase release assay (LDH–assay), trypan blue staining assay and immunohistochemistry utilizing the Annexin V–FITC stain for apoptosis. We were also able to obtain single crystal structures for the tricyclo[6.3.0.02,6]undecane–4,9–dien–3,11–dione (9) and tricyclo[6.3.0.02,6]undecane–3,11–dione (10) scaffolds as well as a derivative, N–(3–methoxybenzyl)–3,11–azatricyclo[6.3.0.02,6]undecane (14f). We also evaluated the possibility that the polycyclic compounds might be able to modulate Ca2+ flux through intracellular Ca2+ channels. Computational methods were utilized to accurately predicted IC50 values and develop a QSAR model with marginal error. The linear regression model delivered r2 = 0.83, which indicated a favorable correlation between the predicted and experimental IC50 values. This model could thus serve as valuable predictor for future structural design and optimization efforts. Data obtained from the crystallographic analysis confirmed the NMR–data based structural assignments done for these compounds in previous studies. Obtaining structural information gave valuable insight into the differences in size and geometric constrains, which are key features for the LTCC activity of these compounds. vii In conclusion, we found that all of the compounds evaluated were able to attenuate Ca2+ influx through the LTCC, with some compounds having IC50 values comparable with known LTCC blockers such as nimodipine. Representative compounds were evaluated for their ability to afford protection against apoptosis induced by 200 ?M H2O2. With the exception of compound 14c (the most potent LTCC blocker in the series, IC50 = 0.398 ?M), most compounds were able to afford protection at two or more concentrations evaluated. Compound 14c displayed inherent toxicity at the highest concentrations evaluated (100 ?M). We concluded that compounds representing both types of structures (pentacycloudecylamines and triquinylamines) have the ability to attenuate excessive Ca2+ influx through the LTCC. In general the aza–pentacycloundecylamines (8a–c) were the most potent LTCC blocker which also had the ability to offer protection in the cell viability assays. However, NGP1–01 (7a) had the most favorable pharmacological profile overall with good activity as an LTCC blocker (IC50 = 86 ?M) and the ability to significantly attenuate cell death in the cell viability assays, exhibiting no toxicity. In addition to their ability to modulate Ca2+ influx from the extracellular environment, these compounds also displayed the ability to modulate Ca2+ flux through intracellular Ca2+ channels. The mechanisms by which they act on intracellular Ca2+ channels still remains unclear, but from this preliminary study it would appear that these compounds are able to partially inhibiting Ca2+–ATPase activity whilst possibly simultaneously inhibiting the IP3R. In the absence of extracellular Ca2+ these compounds showed the ability in inhibit voltage–induced Ca2+ release (VICaR), possibly by modulating the gating charge of the voltage sensor being the dihydropyridine receptors. In future studies it might be worthwhile to do an expanded QSAR study and evaluate the aza–pentacycloundecylamines. To clarify the mechanisms by which the polycyclic compounds interact with intracellular Ca2+ channels we should examine the direct interaction with the individual Ca2+ channels independently. The polycyclic compounds evaluated in this study demonstrate potential as multifunctional drugs due to their ability to broadly regulate calcium homeostasis through multiple pathways of Ca2+ entry. This may prove to be more effective in diseases where perturbed Ca2+ homeostasis have devastating effects eventually leading to excitotoxicity and cell death. / Thesis (Ph.D. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2012.

Compromised calcium homeostasis in the central nervous system (CNS) is implicated as a major contributor in the pathology of neurodegeneration. Dysregulation of Ca2+ homeostasis initiates downstream Ca2+–dependent events that lead to apoptotic and/or necrotic cell death. Increases in the intracellular free calcium concentration ([Ca2+]i) may be the result of Ca2+ influx from the extracellular environment or Ca2+ release from intracellular Ca2+ stores such as the endoplasmic reticulum (ER). Influx from the extracellular environment is controlled predominantly by voltage gated calcium channels (VGCC), such as L–type calcium channels (LTCC) and ionotropic glutamate receptors, such as the N–methyl–D–aspartate (NMDA) receptors. Ca2+ release from the ER occurs through the inositol–1,4,5–triphosphate receptors (IP3Rs) or ryanodine receptors (RyRs) via IP3–induced or Ca2+–induced mechanisms. Mitigation of Ca2+ overload through these Ca2+ channels offers an opportunity for pharmacological interventions that may protect against neuronal death. In the present study the ability of a novel series of polycyclic compounds, both the pentacycloundecylamines and triquinylamines, to regulate calcium influx through LTCC was evaluated in PC12 cells using calcium imaging with Fura–2/AM in a fluorescence microplate reader. We were also able for the first time to determine IC50 values for these compounds as LTCC blockers. In addition, selected compounds were evaluated for their ability to offer protection in apoptosis–identifying assays such as the lactate dehydrogenase release assay (LDH–assay), trypan blue staining assay and immunohistochemistry utilizing the Annexin V–FITC stain for apoptosis. We were also able to obtain single crystal structures for the tricyclo[6.3.0.02,6]undecane–4,9–dien–3,11–dione (9) and tricyclo[6.3.0.02,6]undecane–3,11–dione (10) scaffolds as well as a derivative, N–(3–methoxybenzyl)–3,11–azatricyclo[6.3.0.02,6]undecane (14f). We also evaluated the possibility that the polycyclic compounds might be able to modulate Ca2+ flux through intracellular Ca2+ channels. Computational methods were utilized to accurately predicted IC50 values and develop a QSAR model with marginal error. The linear regression model delivered r2 = 0.83, which indicated a favorable correlation between the predicted and experimental IC50 values. This model could thus serve as valuable predictor for future structural design and optimization efforts. Data obtained from the crystallographic analysis confirmed the NMR–data based structural assignments done for these compounds in previous studies. Obtaining structural information gave valuable insight into the differences in size and geometric constrains, which are key features for the LTCC activity of these compounds. vii In conclusion, we found that all of the compounds evaluated were able to attenuate Ca2+ influx through the LTCC, with some compounds having IC50 values comparable with known LTCC blockers such as nimodipine. Representative compounds were evaluated for their ability to afford protection against apoptosis induced by 200 ?M H2O2. With the exception of compound 14c (the most potent LTCC blocker in the series, IC50 = 0.398 ?M), most compounds were able to afford protection at two or more concentrations evaluated. Compound 14c displayed inherent toxicity at the highest concentrations evaluated (100 ?M). We concluded that compounds representing both types of structures (pentacycloudecylamines and triquinylamines) have the ability to attenuate excessive Ca2+ influx through the LTCC. In general the aza–pentacycloundecylamines (8a–c) were the most potent LTCC blocker which also had the ability to offer protection in the cell viability assays. However, NGP1–01 (7a) had the most favorable pharmacological profile overall with good activity as an LTCC blocker (IC50 = 86 ?M) and the ability to significantly attenuate cell death in the cell viability assays, exhibiting no toxicity. In addition to their ability to modulate Ca2+ influx from the extracellular environment, these compounds also displayed the ability to modulate Ca2+ flux through intracellular Ca2+ channels. The mechanisms by which they act on intracellular Ca2+ channels still remains unclear, but from this preliminary study it would appear that these compounds are able to partially inhibiting Ca2+–ATPase activity whilst possibly simultaneously inhibiting the IP3R. In the absence of extracellular Ca2+ these compounds showed the ability in inhibit voltage–induced Ca2+ release (VICaR), possibly by modulating the gating charge of the voltage sensor being the dihydropyridine receptors. In future studies it might be worthwhile to do an expanded QSAR study and evaluate the aza–pentacycloundecylamines. To clarify the mechanisms by which the polycyclic compounds interact with intracellular Ca2+ channels we should examine the direct interaction with the individual Ca2+ channels independently. The polycyclic compounds evaluated in this study demonstrate potential as multifunctional drugs due to their ability to broadly regulate calcium homeostasis through multiple pathways of Ca2+ entry. This may prove to be more effective in diseases where perturbed Ca2+ homeostasis have devastating effects eventually leading to excitotoxicity and cell death. / Thesis (Ph.D. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2012.

Modern life, which is characterised by automation and mechanisation, causes laziness and inactivity in people all over the world. It in essence deprives one of movement, which negatively affects man and his body. Chronic illnesses caused by an inactive lifestyle lead to unnecessary deaths, which again impacts negatively on the community as a whole. The South African Police Service (SAPS) has far from escaped this worldwide phenomenon. It is, in fact, experiencing an abnormally high death rate, which can be linked directly to police officers’ lifestyle. This study has proven that the average police officer is in extremely poor physical condition, and that this is in all probability the cause of the unusually high natural death rate as well as the high incidence of suicide among SAPS members. The primary objective of this study is the justification of a physical maintenance programme for law enforcement officers. For this programme to be successful, it has to: (i) be relatively inexpensive and provide easily accessible facilities; (ii) be in line with critical physical job requirements; (iii) contribute directly to the maintenance of job-oriented fitness; (iv) include a section that is solely tasked with the physical maintenance of the officers; and (v) form part of the SAPS’s policy on sport. The results of this study show the dire necessity of the immediate implementation by SAPS management of the suggested physical maintenance programme. / Thesis (DPhil (Human Movement Science))--University of Pretoria, 2003. / Biokinetics, Sport and Leisure Sciences / unrestricted

Abstracts in English, Afrikaans and Xhosa / English proficiency is regarded important for economic empowerment in South Africa, since English is the official business language of the country. South Africa is, however, a multilingual country, with 11 official languages. The majority of South African learners do not speak English as first language, but study English as an additional language in school. This leads to English Second Language (ESL) classroom complexities such as multilingualism, negative attitudes to ESL, and various levels of linguistic proficiency, which affect the teaching of the prescribed curriculum. Many learners arrive in secondary school (Grade 8) with underdeveloped English proficiency, which means that a lot of time in ESL classrooms is spent on re-teaching English language concepts, especially grammar concepts. This causes stress for both ESL teachers and learners. This study tested the effectiveness of a self-help ESL grammar intervention programme in order to establish whether existing gaps in grammar knowledge could be closed via self-study outside of the classroom. More specifically, the study asked the question whether learners’ knowledge of Parts of Speech could be enhanced via a self-help intervention programme, which was based on the principles of Systemic Functional Grammar (SFG). SFG is not traditionally used as an instructional framework in ESL classrooms in the South African context. The rationale for assessing the efficiency of an SFG self-help intervention programme was that there is currently a dire need for alternative approaches to teaching ESL grammar, which would assist struggling learners to raise their proficiency levels quickly, and which would allow teachers to continue with the prescribed curriculum. The intervention programme was tested in a controlled quasi-experimental study, which included an experimental group and a control group, and which compared performance in the mid-year examination and year-end examination to performance in a baseline assessment. The results of the study showed that the self-intervention programme was effective in enhancing ESL learners’ knowledge of Parts of Speech, and also had a positive effect on other aspects of grammar knowledge and on writing. Based on these findings, it is recommended that self-regulation and self-instruction be considered for inclusion in ESL syllabi in the South African context, as it can play a positive role in enhancing ESL learners’ linguistic proficiency. / Engelse taalvaardigheid word as belangrik beskou vir ekonomiese bemagtiging in Suid–Afrika, aangesien Engels die offisiële besigheidstaal van die land is. Suid-Afrika het egter elf erkende offisiële landstale en is dus ‘n meertalige land. Die oorgrote meerderheid Suid-Afrikaanse leerders se eerste taal is nie Engels nie, en hierdie leerders neem Engels as tweede taal (ook genoem eerste addisionnele taal) in ‘n formele omgewing op skool. Dit veroorsaak verskeie uitdagings in Engelse tweedetaalklasse, onder andere meertalige leerders, ‘n negatiewe houding teenoor Engels, en oneweredige ontwikkelingsvlakke in Engels. ‘n Groot aantal leerders begin hul sekondêre skoolloopbaan met onderontwikkelde vaardighede in Engels, met name in grammatika. Dit beïnvloed die onderrig van die voorgeskrewe Engelse tweedetaal kurrikulum, veral in Graad 8. Onderwysers is dikwels genoodsaak om baie tyd aan die heronderrig van grammatikale konsepte te spandeer, alvorens die voorgeskrewe Graad 8 kurrikulum hervat kan word. Dit plaas spanning op sowel onderwysers as leerders. Die doel van hierdie studie was om die effektiwiteit van ‘n self-onderrig intervensieprogram te toets – meer spesifiek om te toets of kennisgapings in “Parts of Speech (POS)” oorbrug kan word met ‘n self-onderrig program wat gebaseer is op Sistemiese Funksionele Linguistiek (SFL). SFL word nie tradisioneel in die Suid-Afrikaanse leerprogram gebruik nie, en die rasionaal vir die toetsing van ‘n SFL program was dat daar tans ‘n geweldige vraag is na alternatiewe benaderings tot die onderrig van Engels, wat leerders sal ondersteun om hulle vaardigheidsvlakke snel te verbeter, sodat onderwysers kan voorgaan met die voorgeskrewe kurrikulum. Die SFL intervensieprogram in hierdie studie is deur middel van ‘n gekontroleerde kwasi-eksperimentele metode getoets, wat ‘n eksperimentele groep en ‘n kontrolegroep ingesluit het. Die twee groepe se kennis van woordsoorte is in die middeljaar, asook die eindjaareksamen gemeet, en vergelyk met die resultate van ‘n basislyntoets wat aan die begin van die jaar afgeneem is. Die resultate het bevestig dat die SFL intervensieprogram ‘n positiewe effek gehad het op kennis van woordsoorte. Verdere positiewe effekte was merkbaar in ander aspekte van Engelse grammatika en in skryfvaardigheid. Na aanleiding van hierdie bevindinge is die aanbeveling van hierdie studie dat selfonderrig and self-regulasie oorweeg moet word as belangrike komponente van die Engels tweedetaal sillabus in die Suid-Afrikaanse konteks, aangesien dit ‘n positiewe rol kan speel in die verbetering van Engels tweedetaal leerders se taalvaardigheid. / Ubugcisa kulwimi lwesiNgesi bubaluleke kakhulu ekuxhobiseni ezoqoqosho eMzantsi Afrika kuba silulwimi lwezoshishino olusemthethweni kweli lizwe. Naxa kunjalo uMzantsi Afrika lilizwe elineelwimi ezininzi, apho ezili-11 zamiliselwa njengeelwimi ezisemthethweni. Uninzi lwabafundi baseMzantsi Afrika alusithethi njengolwimi lokuqala isiNgesi, koko lusifunda njengolwimi olongeziweyo esikolweni. Oku kukhokelela kwiingxaki ezininzi kwiklasi efundisa isiNgesi njengoLwimi lwesiBini, ezifana nokusetyenziswa kweelwimi ezininzi kwakunye namanqanaba awohlukileyo olwazi nobugcisa bokusebenzisa ulwimi, nto ezo zichaphazela ukufundiswa kwekharityhulam esekiweyo. Abafundi abaninzi bafika kwisikolo sasesekondari (iBanga lesi-8) bengenalwazi nabugcisa baneleyo besiNgesi, ngenxa yoko, kwiklasi yesiNgesi uLwimi lwesiBini kuchithwa ixesha elininzi kuphindaphindwa ukufundiswa kwesigama sesiNgesi, ngakumbi isigama segrama. Esi sifundo sophando siye sahlola ukusebenza kwenkqubo yongenelelo kufundiso lwegrama yesiNgesi uLwimi lwesiBini apho umfundi azinceda ngokwakhe, ukuze kufunyaniswe ukuba zingavaleka na ezi zikhewu zikhoyo zokuswela ulwazi lwegrama ngokuzifundela ngaphandle kweklasi. Olu phando lujolise ngakumbi kumbuzo wokuba, ingaba ulwazi lwabafundi ngeziGaba zeNtetho lungaphuculwa na ngokusebenzisa le nkqubo yongenelelo yokuzinceda esekelwe kwimithetho-siseko yeSystemic Functional Grammar (iSFG). ISFG ayisetyenziswa ngokwesithethe njengesakhelo sokufundisa kwiklasi yesiNgesi uLwimi lwesiBini eMzantsi Afrika. Esona sizathu sokuvavanya ukusebenza kwale nkqubo yongenelelo yokuzinceda yeSFG, kukuba kukho intswelo enkulu yeendlela ezizezinye zokufundisa igrama yesiNgesi uLwimi lwesiBini, nto leyo inokunceda abafundi abatsala nzima baphucule amaqondo abo obugcisa, kananjalo incede ootitshala bakwazi ukuqhubela phambili nekharityhulam emiselweyo. Le nkqubo yongenelelo yavavanywa kuphando oluphantsi kolawulo olwaziwa ngokuba sisifundo sophando olungagqibelelanga (quasi experimental study), olwaquka iqela lolingelo kunye neqela elisetyenziswa njengomgangatho wentelekiso (control group). Olu phando lwathelekisa indlela abaqhuba ngayo abafundi kwiimviwo zombindi wonyaka nezokuphela konyaka, ithelekiswa kunye nenkqubo yabafundi kuvavanyo olusisiseko. Iziphumo zophando zabonisa ukuba inkqubo yongenelelo yokuzinceda ibe nempumelelo ekuphuliseni ulwazi lwabafundi lweziGaba zeNtetho kwaye ibe nefuthe elakhayo nakweminye imiba yolwazi lwegrama nesakhono sokubhala. Ngokwezi ziphumo kucetyiswa ukuba kuqwalaselwe ukuzilawula nokuzifundisa kwabafundi njengenxalenye yesilabhasi yesiNgesi uLwimi lwesiBini ngokwemeko yaseMzantsi Afrika njengoko oku kuya kuba nefuthe elakhayo ekuphuhliseni ubugcisa babafundi bolwimi lwesiNgesi uLwimi lwesiBini. / Linguistics and Modern Languages / D. Phil. (Languages, Linguistics and Literature)