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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The measurement of broadband ultrasonic attenuation in cancellous bone

Langton, C. M. January 1984 (has links)
No description available.
2

The effects of processing on sodium-potassium and calcium-phosphorus ratios in foods

Ronan, Kathleen M. 04 June 1981 (has links)
The objective of this study was to determine the effects of processing on sodium - potassium and calcium - phosphorus ratios in tuna canned in oil and in water, peanut butter, white and whole wheat flours. Mineral levels were determined by atomic absorption spectrophotometry in food samples at various stages in the production of these finished products. The average sodium - potassium ratios of the tuna samples were: 1.37 raw, 1.24 precooked, 1.87 canned in oil and 1.61 canned in water. Processing did not significantly effect sodium and potassium ratios in canned tuna. The average calcium - phosphorus ratios of the tuna samples were: 0.034 raw, 0.024 precooked, 0.034 canned in oil and 0.065 canned in water. The ratio of the canned in water meat was significantly effected by processing. The average sodium - potassium ratios of the peanut samples were: 0.034 raw, 0.043 roasted, 0.031 blanched and 0.781 peanut butter. The ratio of peanut butter was significantly greater than the ratios of the other peanut samples. The average calcium - phosphorus ratios of the peanut samples were: 0.148 raw, 0.121 roasted, 0.141 blanched and 0.128 peanut butter. These ratios were not significantly effected by processing. The average sodium - potassium ratio was 0.16 in white flours, 0.84 in whole wheat flour and 0.89 in the kernel. The average calcium - phosphorus ratio was 0.14 in white flours, 0.07 in whole wheat flour and 0.07 in the kernel. The ratios of the kernel and whole wheat flour were not significantly different. Processing significantly effected the ratios of the white flour. The preferred concentration of sodium chloride and a 1:1 sodium - potassium chloride mixture in white and whole wheat breads was also studied. Bread samples were made with 1.0%, 0.75% and 0.5% levels of both salt treatments. They were evaluated by an untrained flavor panel for overall desirability with a nine point hedonic scale. The judges preferred a sodium chloride white bread with a 7.0 sodium - potassium ratio, and a sodium chloride whole wheat bread with a 3.29 ratio. These ratios were both lower than those found in commercial products. White and whole wheat breads made with 0.75% sodium chloride were as acceptable as breads made with 1.0% 1:1 sodium - potassium chloride mixture. The sodium - potassium ratio of the salt mixture white bread was 1.20 and the ratio of the whole wheat bread was 0.91. The addition of salt to finished products for flavor had an effect on the sodium - potassium ratio of the foods studied. Also, reducing the amount of added salt to commercial breads and replacing some sodium chloride with potassium chloride were acceptable means of lowering the sodium - potassium ratios of white and whole wheat breads. / Graduation date: 1982
3

Coherent gamma-ray scattering and transmission measurements in bone densitometry

Mossop, J. R. January 1988 (has links)
No description available.
4

Mineral content of sweet corn and broccoli cooked in waters of varying hardness

Bohn, Lorraine Kay, 1959- January 2011 (has links)
Vita. / Digitized by Kansas Correctional Industries
5

The relationship between peak lean tissue velocity and peak bone mineral content velocity during the adolescent growth spurt

Helgason, Nial John 22 August 2005
It has been theorized that muscles generate more force on bone than body weight alone and therefore it is likely that muscle contraction drives and sustains bone adaptation (Frost 1999). Purpose: To investigate the relationship between the timing and tempo of peak growth velocities of lean tissue (LT) and bone mineral content (BMC) in boys and girls at three sites using data derived from individual growth curves. Methods: 72 boys and 70 girls were fitted with growth curves that had a distinguishable peak. Height and weight were measured for each participant and tissue assessment was performed annually using DXA. Factorial ANOVAs were completed to analyse data for differences in age, while forward regression analyses was used between LT and BMC. Results: The peak growth velocity for lean occurred significantly (P<0.05) earlier than the peak growth velocity for bone at all locations except the legs. There was a difference (P<0.001) between genders in the age of peak for both lean tissue and bone tissue at all locations with females peak growth occurring before that of males. When aligned by PHV a significant difference (P<0.05) in the timing of PBMCV was found between the arms and the legs with the peak in bone growth in the legs occurring significantly before peak bone growth in the arms. PLTV was independently associated with PBMCV at the arms (r2= .71, p<0.001), legs (r2= .53, p<0.001) and trunk (r2= .52, p<0.001). Conclusion: In conclusion, LT growth precedes BMC growth and after controlling for gender, size and maturity the magnitude of LT growth is associated with BMC growth. The findings of this study are in support the Muscle-bone Unit (Frost and Schoenau, 2000), which theorizes that localised muscle action is a driving force for bone growth. Future studies are needed to analyse bone strength as it relates to local muscle strength and usage while controlling for confounding variables.
6

The relationship between peak lean tissue velocity and peak bone mineral content velocity during the adolescent growth spurt

Helgason, Nial John 22 August 2005 (has links)
It has been theorized that muscles generate more force on bone than body weight alone and therefore it is likely that muscle contraction drives and sustains bone adaptation (Frost 1999). Purpose: To investigate the relationship between the timing and tempo of peak growth velocities of lean tissue (LT) and bone mineral content (BMC) in boys and girls at three sites using data derived from individual growth curves. Methods: 72 boys and 70 girls were fitted with growth curves that had a distinguishable peak. Height and weight were measured for each participant and tissue assessment was performed annually using DXA. Factorial ANOVAs were completed to analyse data for differences in age, while forward regression analyses was used between LT and BMC. Results: The peak growth velocity for lean occurred significantly (P<0.05) earlier than the peak growth velocity for bone at all locations except the legs. There was a difference (P<0.001) between genders in the age of peak for both lean tissue and bone tissue at all locations with females peak growth occurring before that of males. When aligned by PHV a significant difference (P<0.05) in the timing of PBMCV was found between the arms and the legs with the peak in bone growth in the legs occurring significantly before peak bone growth in the arms. PLTV was independently associated with PBMCV at the arms (r2= .71, p<0.001), legs (r2= .53, p<0.001) and trunk (r2= .52, p<0.001). Conclusion: In conclusion, LT growth precedes BMC growth and after controlling for gender, size and maturity the magnitude of LT growth is associated with BMC growth. The findings of this study are in support the Muscle-bone Unit (Frost and Schoenau, 2000), which theorizes that localised muscle action is a driving force for bone growth. Future studies are needed to analyse bone strength as it relates to local muscle strength and usage while controlling for confounding variables.
7

BINDING OF COPPER, ZINC AND IRON BY SIX DIETARY FIBER SOURCES

Thompson, Sue Angele January 1980 (has links)
Six dietary fiber sources, wheat bran, corn bran, soy bran, oat hulls, rice bran, and cellulose were examined with regard to their abilities to bind copper, zinc, and iron. Their chemical composition, some of their physical properties, and their in vivo action on mineral status in tissues of chicks were investigated. Also, a comparison of the physicochemical properties of neutral detergent treated (NDF) and pepsin-pancreatin treated (EIR) residues was made. The release of endogenous copper, zinc, and iron from the fiber sources was pH dependent. Greater amounts of minerals were released into solution at pH 0.65 than into solution at pH 6.8. After a sequential treatment of pH 0.65 solution, neutralization, then pH 6.8 buffer, the mineral levels in the residues were similar to those remaining in the residues after the near neutral treatment. This indicated that the minerals were rebound after the pH of the solution was raised from acidic to near neutral. The amount of zinc in the residues from the sequential treatment correlated positively to protein and phytic acid contents and negatively to NDF and EIR contents. Neither copper nor iron showed any significant correlations. Hydrogen ion buffering capacities were determined for three preparations of the six fiber sources: (1) untreated, original material; (2) NDF-treated; and (3) EIR-treated materials. The buffering capacities were expressed as functions of the slopes of titration curves, where the smaller the slope, the greater the buffering capacity. The treated preparations had lower buffering capacities than did the untreated preparation. The treatments reduced the amounts of digestible/soluble components, especially protein in the fiber sources. Protein content was strongly correlated to buffering capacity for the untreated and the EIR-treated preparations but not for the NDF-treated preparation. Wheat bran, soy bran, oat hulls, and cellulose were subjected to NDF and EIR treatments, and the residues were used as column material for cation exchange experiments. A factorial experiment was performed using fibers by treatments by three solutions. The solutions were copper alone, zinc alone, and copper-zinc in combination. Cation exchange capacities (CEC) and protein contents were also determined. The CEC values for the residues from the two treatments for wheat bran and cellulose were similar but were very different for the soy bran (EIR-treated CEC was higher than NDF-treated) and oat hulls (NDF much greater than EIR). More mmoles of copper were bound than zinc whether presented alone or in equimolar combination. Protein content correlated to mmoles mineral bound for only the NDF-treated residues and only when the minerals were presented singly. These in vitro experiments demonstrated the intrinsic differences of the fiber sources. One fiber source may be beneficial to nutritional status while another may be detrimental. The fiber isolation technique produced residues with different compositions and different physical properties. Future biochemical investigations of dietary fiber must acknowledge the possible divergence from physiological reality which results from the isolation methodology. The chick feeding study used diets which had the fiber sources added to be equivalent to the addition of 6% dietary fiber (as NDF). At this level, all the fiber sources, except rice bran, resulted in adequate growth and adequate deposition of tissue minerals. The chicks on the rice bran diet had lowered feed intakes, significantly reduced growth and significantly lower tibia zinc, iron, and manganese levels. One factor in the rice bran diet, which may have influenced the status of the chicks, was its phytic acid content which was the highest of the fiber sources. This in vivo experiment again indicates the dissimilarity in effects of the dietary fiber sources.
8

Optimizing fracture management: Correlating the physical and mechanical properties of bone to computed tomography to generate an estimate of bone quality

Crookshank, Meghan Cathleen Maria 05 February 2008 (has links)
Non-invasive estimates of bone quality are of great interest as they could potentially improve the diagnosis and treatments for bone disorders, such as osteoporosis, and could aid in preoperative planning of surgical interventions, improving patient outcomes in orthopaedic trauma. Quantitative computed tomography (QCT) is currently being investigated as a method of estimating structural bone mineral content (sBMC) and, thus, bone quality. However, the reported correlations between QCT and sBMC have been variable and the relationships reported between sBMC and the apparent elastic modulus (E*) of bone have been even more variable. A series of investigations are presented, relating QCT, sBMC, apparent density and the E* of bone. These studies were performed with the ultimate objective of determining the appropriateness of QCT as a predictor of the E* of bone and whether the E* of bone could be predicted from information regarding the sBMC and apparent density. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2008-01-31 22:00:08.77 / This work was funded by the Canadian Institutes of Health Research.
9

Changes in Bone Mineral Content and Density After Stroke

Hamdy, R. C., Krishnaswamy, G., Cancellaro, V., Whalen, K., Harvill, L. 01 January 1993 (has links)
The purpose of this study was to determine whether there are differences in bone mineral content and density between paralyzed and nonparalyzed sides of patients who had sustained strokes associated with unilateral muscle weakness, to determine the relationship between duration of stroke and degree of demineralization and to compare the degree of demineralization in upper and lower limbs. The bone mineral content and density were measured by dual photon absorptiometry (high resolution scanning mode, Lunar DP4) in ambulant patients with a history of single completed strokes associated with unilateral weakness. The bone mineral content and density of each limb was determined by the region of interest analysis program. In the 30 patients included in this study, the bone mineral content and density were significantly less on the paralyzed than on the nonparalyzed side. The degree of demineralization was more pronounced in the upper than in the lower limbs. The mean percentage differences in bone mineral content and density between paralyzed and nonparalyzed arms were 13.8% (P < 0.00001) and 7.95% (P = 0.0003), respectively, and between paralyzed and nonparalyzed legs the differences were 4.5% (P = 0.0012) and 3.42% (P = 0.0028), respectively. A better correlation was noted between the time elapsed since the stroke and the degree of demineralization in the upper limbs (r = 0.75, P < 0.0001), than in the lower limbs (r = 0.60, P = 0.0004). In conclusion, patients who have strokes associated with muscle weakness are at an increased risk of developing osteoporosis on the paralyzed side and particularly in the upper limbs.
10

Identifying a non-invasive measure of bone status in dairy cattle

Keene, Beth E. 09 October 2003 (has links)
The objectives of this research were to evaluate non-invasive measures of bone mineral content (BMC) and bone mineral density (BMD) as rapid, on-farm tools to assess phosphorus (P) status in dairy cows. In addition, the effects of parity and stage of lactation on measures of BMC of the fused 3rd and 4th metacarpal bone and of caudal vertebrae 14 and 15 were assessed. The caudal vertebrae and right front metacarpal (sample pairs) were excised from 107 Holstein cull cows following slaughter. Parity, age, and days in milk (DIM) of the donor animal were obtained for 43 pairs of samples. Samples were grouped by parity (1, 2, 3, and >4) and stage of lactation (Stage 1 = < 90 DIM, Stage 2 = > 90 and < 150 DIM, Stage 3 = >150 and < 250 DIM and Stage 4 = > 250 DIM). Samples were analyzed for BMC and BMD with dual energy X-ray absorptiometry (DXA), BMC with radiographic photometry (RP), breaking strength with mechanical methods, and mineral content with chemical procedures. Estimates of BMC obtained with RP and DXA were poorly related to chemical measures of actual BMC and to measures of breaking strength. In caudal vertebrae 14 and 15, increasing stage of lactation decreased energy to peak load with the lowest values observed in late lactation. Stage of lactation had no effect on BMC measured chemically in the caudal vertebrae or metacarpal. Parity did not affect breaking strength of the metacarpal or caudal vertebrae or total ash or P content of any bone. Results indicated that imaging techniques are not useful measures of BMC in mature dairy cattle. / Master of Science

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