Currently normalcy indices have not been used to evaluate the gait of normal healthy adults. The purpose of this study was to assess the appropriateness of using a normalcy index in assessing gait patterns by investigating normalcy indices of different compositions created from an adult population. Thirty-seven normal and healthy subjects between the ages of nineteen and sixty-six underwent a clinical gait analysis. Ten trials from the left and right sides of the body were averaged. From the averaged data, sixteen kinematic variables were chosen for further analysis. Principal component analysis was applied to the variables and four separate normalcy indices were formed. They consisted of a right side, left side, left and right combined, and average of both sides indices. For the left side index, 23.41% of the variance was accounted for in the principle component. In the right side index, 25.35% of the variance was accounted for. 25.45% and 23.95% of the variance was accounted by the PC in the average of both sides and the left and right combined indices. The mean index scores of the left and right indices are 6.48 and 8.38. Index score for the average of both sides and left-right combined indices is 6.80. A paired samples t-test showed that the left and right indices were significantly different at the .01 level. The mean of the index from both sides and the left-right combined were not significantly different with an alpha of 0.969. The significant difference between the left and right side indices suggests that with further refinement, normalcy indices may possibly be used to assess the symmetry of gait. / School of Physical Education, Sport, and Exercise Science

Indian Childhood Cirrhosis (ICC) is associated with excessive copper ingestion and hepatic deposition, is preventable by preventing copper ingestion and is partially treatable by copper chelation. However, copper administration causes only minimal hepatic damage in the rat and an acute rather than chronic liver injury in sheep. The hypothesis is explored that a second hepatic insult is synergistic with copper in causing cirrhosis. D-galactosamine was administered, to control rats and to rats orally dosed with copper acetate, to induce an acute hepatic injury documented by serum transaminases and liver histology. Surprisingly, copper-dosed rats (liver copper 607+129 ug/g, controls 48+7) were resistant to galactosamine-induced injury. Oral copper reduced the quantitative faecal anaerobical1y cultured bacterial count, suggesting that reduction in gut-derived portal vein endotoxin may explain the protective effect. Using the carbon tetrachloride model, copper again ameliorated, rather than aggravated, the hepatic injury. Impaired prostaglandin or leukotriene synthesis are discussed as possible mechanisms. To evaluate a possible disorder of copper transport in ICC, copper distribution amongst human serum proteins was investigated. In normal adults, copper was associated with caeruloplasmin (71+4%), "transcuprein" (7+2%), albumin (19+4%) and with amino acids (2+3%). Caeruloplasmin and caeruloplasmin-copper concentrations were low in neonates and symptomatic Wilson's disease. In contrast to the neonate, Wilson's disease exhibited raised total serum copper and non-caeruloplasmin-copper. In ICC, serum levels of caeruloplasmin and caeruloplasmin-copper were normal, but transcuprein- and albumin-bound copper were elevated. Raised concentrations of non-caeruloplasmin-copper in ICC and Wilson's disease perhaps represent overspill into the serum from a copper-laden liver. In serum from children with malignancy, copper and caeruloplasmin concentrations were high as previously reported. Unexpectedly transcuprein- and albumin-bound copper were also markedly elevated. It is to be determined whether this results from tissue catabolism of caeruloplasmin or from increased hepatic caeruloplasmin synthesis and copper turnover. Caeruloplasmin gene expression was investigated in adult and neonatal rat liver, to determine whether the copper profile seen in neonates results from a pre-translational defect in caeruloplasmin synthesis. Detection of mRNA in samples of Northern blotted polyadenylated RNA, using a 32P-labelled caeruloplasmin cDNA probe, demonstrated that the mRNA species isolated from the neonates was not different from that in the adults, with an apparent size of 4400 nucleotides. A reduced mRNA detection in neonatal rats was also shown. Whether this was sufficient to account for the diminished total serum copper and caeruloplasmin oxidase activity is not understood.

The aim of this study is to investigate the processes that underlie image motion detection in human vision. To do this I have investigated motion perception for a wide range of stimulus velocities across the visual field, and have made use of different stimuli. Two mechanisms were revealed at different positions across the visual field as a result of the examination of the temporal properties of the Lower Threshold of Motion (LTM), that is, the lowest velocity that is reliably detected. The results for central vision showed that the LTM is mediated by a code that utilizes the spatial displacement transversed by the stimulus. For peripheral vision, the LTM is mediated by a code that utilizes the velocity or temporal frequency of the stimulus. This raised the question, do these two processes underlie image motion processing at all eccentricities with different sensitivities at threshold? To investigate this question, a wide velocity range was used to assess the ability of the visual system to discriminate different speeds. The temporal and spatial properties of the stimulus were individually disrupted to reveal the critical cues for velocity discrimination. The results show the presence of two processes at all eccentricities. The two processes can be characterised as a displacement code, and a velocity code. Evidence is shown that the velocity code uses 'velocity' information and not solely temporal frequency information. For central vision, the displacement code is most sensitive for short stimulus durations. The duration at which it is most sensitive is inversly proportional to the velocity of the stimulus. The velocity code is most sensitive at long term regions of the visual field. However, the range of velocities to which each mechanism is sensitive changes at different rates across the visual field. This leaves a range of low velocities which are detected only by the velocity mechanism at large eccentricities. Further investigation into the displacement code has revealed that this code can be characterised by an optimal displacement. This is less than the 1/4 of a spatial cycle of the stimulus which is proposed value for quadrature phase. Also luminance contrast was found to be an important parameter of the motion process. The two codes described above could be mediated by two motion areas of the primate visual cortex: the striate and prestriate cortex. From recent single cell studies, the emerging properties of neurons in these two parts of the visual cortex suggest that the displacement code may be mediated by the striate cortex, and the velocity code by the middle temporal area of the pre striate cortex.

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