Thesis (M. Aud.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (leaves 132-149). Also available via the World Wide Web.

Iroquois genes encode a family of highly conserved TALE homeodomain transcription factors that are involved in multiple developmental processes. Physiological tests indicated that Irx3 and Irx5 mutant mice displayed hearing impairment. However, the functions of these two genes during inner ear development are not known. The aim of this study is to characterize the roles of Irx3 and Irx5 during mammalian inner ear development using mouse models, in order to reveal the underlying mechanism for the hearing abnormality in the mutants. Two mouse mutants, Irx3tauLacZ and Irx3flox5EGFP with β-gal and EGFP reporters, were analyzed to examine the expression of these two genes in the otic vesicle and cochlear epithelium. In the otocyst, both Irx3 and Irx5 were expressed in the ventral-medial region. Irx5 expression was restricted to the non-sensory domain of the cochlear epithelia, while Irx3 was widely expressed, including the auditory sensory organ, the organ of Corti. The overlapping expression patterns of Irx3 and Irx5 suggest that they may share redundant functions. To investigate the roles of Irx3 and Irx5 during inner ear development, phenotypic analysis was performed on Irx3-/-, Irx5-/- and Irx3/5-/- mutant embryos. As shown by paint-filling analysis, Irx3/5-/- displayed shortened cochlear duct, enlarged cochlear lumen with fused sensory organ. Whole-mount phalloidin staining of hair cell bundles showed that Irx3-/- displayed occasional ectopic inner hair cells. Moreover, only supernumerary vestibular hair cell-like cells were developed in Irx3/5-/- mutant. These results suggest that Irx3 and Irx5 are required for inner ear morphogenesis and the formation of organ of Corti. To understand the effect of Irx3 and Irx5 in the cellular patterning of the cochlea, mutant cochleae were analyzed with markers for different regions of the cochlear epithelia. Altered expression domain of MyoVIIa, Sox2 and Gata2 in Irx3/5-/- cochlea revealed that the boundary between the Kolliker’s organ and the organ of Corti was lost and the location of sensory and non-sensory region was shifted. These results imply that Irx3 and Irx5 function in the establishment of the sensory/non-sensory boundary. It is known that p27kip1 regulates the wave of cell cycle exit in the developing organ of Corti and Sox2 takes part in prosensory specification. To explore the underlying reason for the patterning defects in Irx3/5-/- mutant, cochlear duct from prosensory stages were analyzed. Irx3/5-/- showed altered Sox2 and p27kip1 expression, with expanded prosensory domain and disrupted cell cycle exit. Ectopic prosensory proliferation was detected in the middle turn of the cochlear duct at E13.5 by BrdU incorporation assay. Therefore, Irx3 and Irx5 may participate in the subdivision of sensory territory in developing cochlea by controlling prosensory proliferation. In summary, this study demonstrates that Irx3 and Irx5 cooperate in multiple aspects of inner ear development: an early role to regulate prosensory proliferation and cell cycle exit; a second role to regulate cellular patterning of the cochlear duct by controlling the setting of sensory/non-sensory boundaries in the cochlea; a later role to regulate inner ear morphogenesis. This study supports the idea that Irx3 and Irx5 act as patterning genes during vertebrate evolution. / published_or_final_version / Biochemistry / Master / Master of Philosophy

No description available.

This study investigates the effect of training in auditory discrimination on the learning of music concepts. The study draws on Klausmeier's theory concerning the role of discrimination in concept learning, and on Gibson's theory concerning the process of discrimination. Six hypotheses are tested: two stating that a particular program of auditory discrimination training positively affects the performance of pitch and rhythm conceptual tasks, two stating that age positively relates to such performance, and two stating that if the effect of initial auditory discrimination ability is eliminated, there will be no significant difference between the achievements of 7 - 8 year-old and 8 - 9 year-old students performing the said tasks. These hypotheses are tested in an experiment where 232 students participated. All were given a specially constructed Auditory Recognition Test to assess initial auditory discrimination ability before instruction, and all received the ordinary music instruction at school. Students in the experimental group received additionally a short, self-administered training module on discriminating auditory attributes of pitch, register, duration and tempo. These were high-low, long-short, and fast-slow. Following instruction, the experimental and control groups were given a specially constructed Music Concepts Achievement Test to assess their performance. A 2 x 2 factorial design is used to relate discrimination training and age to the performance of conceptual tasks. Variance and covariance analyses are performed to test the hypotheses. Results demonstrate a significant positive effect of the auditory discrimination training on the performance of pitch and rhythm tasks (p < .001), and a significant positive relationship between age and the performance of these tasks (p < .001). However, upon eliminating the effect of initial discrimination ability, age is no longer significant (p = .54 in pitch, and p = .181 in rhythm). The study concludes that training in auditory discrimination facilitates the learning of music concepts and that improvement in auditory discrimination which is gained with age facilitates such learning. These conclusions indicate that auditory discrimination training could improve the learning of many music concepts, and thus become a strategy for the achievement of important objectives in music education. / Theses (Ph.D.)-University of Natal, Durban, 1984.

Stress is associated with a vast array of negative outcomes for both physical and mental health. Based on evidence that stress influences temperature, and that psychology and physiology influence each other, we investigated the novel possibility that reducing brain temperature reduces stress in a sample of 91 university students. We used head fanning to reduce brain temperature and measured this change with an infrared ear thermometer. Participants were randomly assigned so that the fans faced toward half of the participants (cooling condition) and faced away from the other half (non-cooling control condition). Differences in stress between conditions during the Vandenberg and Kuse (1978) Mental Rotations Test were then examined to test the hypotheses that (a) cooling would buffer stress and (b) that this would be mediated by changes in brain temperature, as indicated by ear temperature. Participants in the cooling condition were less stressed (p = .02) and also performed better (p = .03) during the task but neither of these findings were mediated by ear temperature. Thus, some uncontrolled variable(s), and not changes in temperature, may have been responsible for the effect of cooling on stress. Alternatively, error in measuring brain temperature may have obscured the hypothesised causal relationship between temperature and stress. More research is needed to confirm whether cooling the head is a simple way to manage stress.

Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 6 uppsatser.

Thesis (M.Eng.). / Written for the Dept. of Biomedical Engineering. Title from title page of PDF (viewed 2008/05/13). Includes bibliographical references.

Thesis (M. Sc.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (leaves 109-118). Also available via the World Wide Web.

Thesis (M. Aud.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (p. 92-108). Also available via the World Wide Web.

Thesis (Ph. D.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains x, 117 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 109-117).