The present study aims to resolve previous disputes about whether or not non-palatalized consonants exhibit secondary velarization in Russian, and if so what this corresponds to articulatorily. Three questions are asked: 1) are Russian non-palatalized consonants velarized or not? If so, 2) what are the articulatory properties of velarization? and 3) how is the presence or absence of secondary velarization affected by adjacent vowels? To answer these questions, laryngeal and lingual ultrasound investigations were conducted on a range of non-palatalized consonants across different vowel contexts. The results of the study show that 1) Russian non-palatalized consonants are not pharyngealized in the sense of Esling (1996, 1999, 2005), 2) /l/ and /f/ are uvularized, 3) /s/ and /ʂ/ can feature either uvularization or velarization. The study also shows that secondary articulations of Russian non-palatalized consonants are inherent rather than dependent on vowel context. / Graduate / 0290 / natallia@uvic.ca

Therapeutic efficacy of drugs depends on their ability to reach the treatment target. Drugs that exert their effect within cells are constrained by an inability to cross the cell membrane. Methods are being developed to overcome this barrier including biochemical and biophysical strategies. The application of ultrasound with microbubbles increases the permeability of cell membranes allowing molecules, which otherwise would be excluded, to enter the intracellular space of cells; a phenomenon known as sonoporation. This thesis describes studies aimed at improving our understanding of the mechanism underpinning sonoporation and of the exposure parameters affecting sonoporation efficiency. Cancer cells (KHT-C) in suspension were exposed to ultrasound and microbubbles – total of 97 exposure conditions. The effects on cells were assessed through uptake of cell-impermeable molecules (10 kDa to 2 MDa FITC-dextran), cell viability and microscopic observations of the plasma membrane using flow cytometry, colony assay and electron microscopy techniques. Sonoporation was a result of the interaction of ultrasound and microbubbles with the cell membrane. Disruptions (30-100 nm) were generated on the cell membrane allowing cell impermeable molecules to cross the membrane. Molecules up to 2 MDa in size were delivered at high efficiency (~70% permeabilisation). Sonoporation was short lived; cells re-established their barrier function within one minute, which allowed compounds to remain inside the cell. Following uptake, cells remained viable; ~50% of sonoporated cells proliferated. Sonoporation efficiency depended on ultrasound and microbubble exposure conditions. Microbubble disruption was a necessary but insufficient indicator of ultrasound-induced permeabilisation. The exposure conditions can be tailored to achieve a desired effect; cell permeability of ~70% with ~25% cell death versus permeability of ~35% with ~2% cell death. In addition, sonoporation depended on position in the cell cycle. Cells in later stages were more prone to being permeabilised and killed by ultrasound and microbubbles. This study indicated that sonoporation can be controlled through exposure parameters and that molecular size may not be a limiting factor. However, the transient nature may necessitate that the drug be in close vicinity to target cells in sonoporation-mediated therapies. Future work will extend the investigation into in vivo models.

Ultrasound has been widely used in medical diagnostic imaging to image soft tissues. Compared with other methods, ultrasound is superior with no ionizing-radiation, easy portability, low cost, and the capability to provide elasticity information. Conventional ultrasound images provide distorted image information when the ultrasound beam is not normal to the bone structures. In this thesis, we present two imaging algorithms: reverse time migration (RTM) and split-step Fourier migration (SSFM), to image long bones using ultrasound. The methods are tested using simulated data sets. The reconstructed images show accurate cortical thickness measurement and provide the correct fracture dip. The images also clearly illustrate the healing process of a 1-mm wide crack with different in-filled tissue velocities simulating fracture healing. Two in-vitro examples using fractured bones are also presented. The study has showed that the migration methods have great potential to quantify bone fractures and monitor the fracture healing process.

Pathological phenomena often change the mechanical properties of the tissue. Therefore, estimation of tissue mechanical properties can be of clinical importance. Ultrasound elastography is a well-established strain estimation technique. Until recently, mainly 1D elastography algorithms have been developed. A few 2D algorithms have also been developed in the past. Both of these two types of technique ignore the tissue motion in the elevational direction, which could be a significant source of decorrelation in the RF data. In this thesis, a 3D elastography algorithm that estimates all the three components of tissue displacement is implemented and tested statistically. In this research, displacement fields of mechanical models are simulated. RF signals are then generated based on these displacement fields and used as the input of elastography algorithms. To evaluate the image quality of elastograms, absolute error, SNRe, CNRe and CNRasse are computed. The SNRe, CNRe and CNRasse values are investigated not only under different strain conditions, but also in different frame locations, which forms 3D strain filters. A statistical comparison between image qualities of the 3D technique and 2D technique is also provided. The results of this study show that the 3D elastography algorithm outperforms the 2D elastography algorithm in terms of image quality and robustness, especially under high strain conditions. This is because that the 3D algorithm estimates the elevational displacement, while the 2D technique only estimates the axial and lateral deformation. Since the elevational displacement could be an important source for the decorrelation in the RF data, the 3D technique is more effective and robust compared with the 2D technique.

Accurate and reliable measurement of meat quality is essential for the Australian beef industry to remain competitive in both the domestic and export markets. Recent developments of the resonator technique have lead to the commercial availability of the High Resolution Ultrasound Spectroscope (HR-US). This research project was designed to assess the potential of HR-US for the analysis of post-mortem bovine muscle. This was accomplished by; 1) establishing a suitable measurement protocol that considered sources of variability, 2) the effects of post-mortem aging on HR-US parameters, 3) analysis of thermal related changes that occur in muscle, and extracted connective tissue during heating, and 4) the use of HR-US for the measurement of the intramuscular fat. A procedure for the measurement of bovine muscle with HR-US was established. Briefly, an external semisolid cell was used as the measurement cell. The frequency range of 2000 KHz to 3000 KHz was selected as the most suitable for whole muscle analysis and all five resonance peaks within this range were analysed and used to obtain velocity and attenuation values of the meat sample. Water was used as the reference media, and measurements were conducted at 250C. Changes were made to this method during experimental work depending on the sample being run and the objectives of the study. The measurement protocol was shown to be repeatable. Factors likely to cause variation in measurements of the samples, such as water loss and freeze-thaw, were also considered when developing the operational parameters of the study. High resolution ultrasound spectroscopy was applied to measure the post-mortem changes that occur in bovine muscle. Using two muscle types, Semitendinosus and Psoas major, significant changes were observed in HR-US parameters with ageing. Significant increases in the acoustic impedance of bovine muscle with increased ageing time were attributed to degradation of the muscle structure. This was confirmed in transmission electron microscopy images where clear disruption the myofibillar structure was apparent in the muscle at 21 days post-mortem.In localised regions the Z bands and the adjoining actin fibres were totally degraded. Water loss from the muscle system had a significant influence on HR-US measurements. Thermal related changes that occur in whole bovine muscle and in isolated intramuscular connective tissue were observed with HR-US. Heat induced changes were identified in whole muscles and included the melting of the fat within samples at 48oC, coagulation of sarcoplasmic proteins between 450C and 55oC, and the shrinkage of collagen fibres at 630C. An 80% reduction in the attenuating properties of extracted connective ageing in buffer solution was observed within the first 5 days. This is attributed to the degradation of proteoglycans and the resulting disassociation of collagen fibrils. Structural changes occurring in extracted connective tissue were observed with TEM. HR-US measurements proved to be highly sensitive to identifying temperatures at which transitions occurred. Unfolding of the triple helix structure of collagen was identified in velocity transitions between 59°C and 63oC. HR-US results suggested a greater sensitivity to thermal related changes in extracted intramuscular connective tissue when compared with differential scanning calorimeter results. An increase in temperature was observed for thermal denaturation of collagen with ageing, however a reduction was also observed in the temperature range at which the denaturation process occurred. Temperature ramps conducted on extracted intramuscular bovine showed a reduction in velocity from 1613.1m/s at 250C to 1343.1 m/s at 900C equalling an overall reduction in velocity of 270m/s. A transition in the velocity trend seen at 46°C indicates the majority of the triglycerides are melted (or in liquid state) above this temperature. Results are confirmed with differential scanning calorimeter thermogram. HR-US measurements showed high sensitivity to increasing concentration of bovine fat in prepared emulsions with an adjusted R2 99.46% for velocity measurements taken at 5100 kHz. Attenuation values at 8100 kHz also showed a strong linear response to increasing fat concentration in the emulsion (R2 98.77). The use of HR-US for the measurement of intramuscular bovine fat demonstrated a high sensitivity to extracted bovine fat in prepared emulsions. An increase in the intramuscular fat content of whole bovine muscles resulted in a reduction in the velocity measurements and an increase in the attenuation of the ultrasonic signal. This provides the basis for potential method for the prediction intramuscular fat in bovine muscle. The present studies have highlighted the complexities of investigations relating to meat quality and have demonstrated the diversity of data required to assess quality. Only when comprehensive data are available, can we hope to accurately determine meat quality and predict how it will vary with changes in animal production and meat processing.

The interplay of structures in the finger that facilitate movement is complex and not yet fully understood. Subtle finger injuries are often missed during the initial assessment in the Emergency Department, because clinical examination of the acutely injured hand can be difficult. The consequences of unrecognized finger injuries can be devastating for the patient. Ultrasound imaging of tendons is a useful investigative tool although little has been published regarding the reliability of finger tendon measurements. The overall objective of this project was to establish if bedside ultrasound imaging of tendons was possible and useful in the setting of acute injury. The project was divided into two studies.In the first study, 65 apparently normal volunteers were scanned to allow the principal investigator to practise and refine the ultrasound technique. The dimensions of the Extensor Digitorum Longus and two flexor tendons combined (Flexor Digitorum Profundus and Flexor Digitorum Superficialis) were measured in both transverse and longitudinal sections. Fifteen of the volunteers had their left middle fingers scanned twice within 48 hours to establish the test to retest reliability of tendon measurement. The established scanning technique was simple to perform and the scans, including both static and real time images, were completed within five minutes. All volunteers were able to tolerate a full scan. Measurement of tendon width showed fair to good reliability (Intra class correlation [ICC] of flexor tendons = 0.66, ICC of extensor tendon = 0.54). However measurement of the depth of all the tendons was unreliable test to retest (ICC < 0.37).In the second study, 30 patients who presented to the Emergency Department at Lismore Base Hospital with hand injuries were scanned for evidence of tendon injury and tendon gliding restriction. The patient’s ability to tolerate ultrasound examination was investigated. The scan findings were compared with the clinical findings and then to the operation report or to the patient’s self reported outcome, one month after injury.Patients were willing to undergo ultrasound examination regardless of the extent of their injury. There was a significant difference (p = 0.04) in scan tolerance related to the site of injury with 50% of those with extensor surface injuries having completed scans in comparison to 36% with flexor surface injuries and 9.1% of finger tip injuries. Injury mechanism was not related to scan tolerance.Excluding a partial tendon laceration was technically difficult due to the presence of anisotropy artefact. However, all complete tendon lacerations were successfully identified prior to surgery. The gliding of the tendons was easy to visualize and abnormal gliding was found to be a marker of tendon injury.The overall results show that ultrasound imaging of finger tendons at the bedside in the Emergency Department is a feasible examination to perform. The addition of ultrasound examination, however, did not identify any cases of tendon injury not already suspected on routine clinical examination.Therefore, this pilot study suggests that routine use of ultrasound examination to detect finger tendon injury in the Emergency Department setting will not prove to be a useful investigation. There may be a role for ultrasound as a screening tool as the gliding of normal tendons differed noticeably from the gliding of injured tendons. The presence of normal tendon gliding may be helpful in identifying those patients that are safe to be discharged from the Emergency Department without further evaluation.

The interplay of structures in the finger that facilitate movement is complex and not yet fully understood. Subtle finger injuries are often missed during the initial assessment in the Emergency Department, because clinical examination of the acutely injured hand can be difficult. The consequences of unrecognized finger injuries can be devastating for the patient. Ultrasound imaging of tendons is a useful investigative tool although little has been published regarding the reliability of finger tendon measurements. The overall objective of this project was to establish if bedside ultrasound imaging of tendons was possible and useful in the setting of acute injury. The project was divided into two studies.In the first study, 65 apparently normal volunteers were scanned to allow the principal investigator to practise and refine the ultrasound technique. The dimensions of the Extensor Digitorum Longus and two flexor tendons combined (Flexor Digitorum Profundus and Flexor Digitorum Superficialis) were measured in both transverse and longitudinal sections. Fifteen of the volunteers had their left middle fingers scanned twice within 48 hours to establish the test to retest reliability of tendon measurement. The established scanning technique was simple to perform and the scans, including both static and real time images, were completed within five minutes. All volunteers were able to tolerate a full scan. Measurement of tendon width showed fair to good reliability (Intra class correlation [ICC] of flexor tendons = 0.66, ICC of extensor tendon = 0.54). However measurement of the depth of all the tendons was unreliable test to retest (ICC < 0.37).In the second study, 30 patients who presented to the Emergency Department at Lismore Base Hospital with hand injuries were scanned for evidence of tendon injury and tendon gliding restriction. The patient’s ability to tolerate ultrasound examination was investigated. The scan findings were compared with the clinical findings and then to the operation report or to the patient’s self reported outcome, one month after injury.Patients were willing to undergo ultrasound examination regardless of the extent of their injury. There was a significant difference (p = 0.04) in scan tolerance related to the site of injury with 50% of those with extensor surface injuries having completed scans in comparison to 36% with flexor surface injuries and 9.1% of finger tip injuries. Injury mechanism was not related to scan tolerance.Excluding a partial tendon laceration was technically difficult due to the presence of anisotropy artefact. However, all complete tendon lacerations were successfully identified prior to surgery. The gliding of the tendons was easy to visualize and abnormal gliding was found to be a marker of tendon injury.The overall results show that ultrasound imaging of finger tendons at the bedside in the Emergency Department is a feasible examination to perform. The addition of ultrasound examination, however, did not identify any cases of tendon injury not already suspected on routine clinical examination.Therefore, this pilot study suggests that routine use of ultrasound examination to detect finger tendon injury in the Emergency Department setting will not prove to be a useful investigation. There may be a role for ultrasound as a screening tool as the gliding of normal tendons differed noticeably from the gliding of injured tendons. The presence of normal tendon gliding may be helpful in identifying those patients that are safe to be discharged from the Emergency Department without further evaluation.

Thesis (Ph.D.)--Drexel University, 2008. / Includes abstract and vita. Includes bibliographical references (leaves 143-151).

Thesis (M.S.)--Montana State University--Bozeman, 2004. / Typescript. Chairperson, Graduate Committee: Aleksandra Vinogradov. Includes bibliographical references (leaves 83-90).

Thesis (Ph. D.)--Colorado State University, 2004. / Includes bibliographical references.