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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.
91

Mass Balance Tracer Techniques for Integrating in situ Soil Ingestion Rates into Human and Ecological Risk Assessments

Doyle, James 12 January 2012 (has links)
Quantitative soil ingestion studies employing a mass balance tracer approach have been used to determine soil ingestion rate for use in human health risk assessments (HHRAs). Past studies have focused on soil ingestion in populations living in urban/suburban environments and the results have been highly variable. Moreover, there is a paucity of reliable quantitative soil ingestion data to support human health risk assessments of other lifestyles that may be predisposed to ingesting soil, such as indigenous populations following traditional lifestyles. Thus, the primary objective of the research was to determine if populations following lifestyles typical of traditional land use practices in rural or wilderness areas ingest more soil than populations living in urban or suburban environments. Further, the research investigated the use of alternative mass balance tracers, specifically isotopes of the 238U and 232Th decay series, to reduce soil ingestion estimate variability. Mass balance tracer methods were developed and validated in a pilot canine study, and methods using isotope tracers were adapted to permit quantification of sediment ingestion in the benthic fish Moxostoma macrolepidotum (Shorthead Redhorse Sucker). A pilot human soil ingestion study of 7 subjects from an Aboriginal community in British Columbia was conducted over a 3-week period. The mean soil ingestion rate calculated using the daily means of the 4 elemental tracers with the lowest food-to-soil ratios (i.e., Al, Ce, La, Si) was observed to be approximately 74 mg d-1 (standard deviation 91 mg d-1), The median soil ingestion rate was 60 mg d-1, and the 90th percentile was 196 mg d-1. These soil ingestion rate estimates are higher than those currently recommended for HHRAs of adults, and higher than those obtained in most previous studies of adults. However, the estimates are much lower than the earlier qualitative assessments for subsistence lifestyles (i.e., 330-400 mg d-1). The study results also demonstrated that isotopes of the 238U and 232Th decay series radionuclide are not reliable mass balance tracers for estimating soil ingestion in humans; however, they may be useful for quantifying soil and sediment ingestion in wildlife.
92

Effect of carbohydrate ingestion during exercise on performance measures of wheelchair athletes

Hynes, Heather 23 September 2009
The primary purpose of this study was to determine the effect of ingesting an 8% carbohydrate (CHO) beverage during a moderate intensity exercise trial on performance outcomes, fuel utilization and blood glucose levels of wheelchair athletes (spinal cord injury (SC I) or cerebral palsy (CP)). The secondary purpose was to analyze the dietary intake of the eight participants and to determine if they were meeting current sport nutrition guidelines for macronutrients and fluids recommended in the joint position statement developed by the American Dietetic Association (ADA), the American College of Sports Medicine (ACSM) and Dietitians of Canada (DC).<p> Under random, double blind conditions eight athletes (6 males, 2 females); mean age 36 ± 8.5 y with a SCI (n = 7) or CP (n = 1) completed two exercise trials on an adapted stationary hand cycle; each trial was 60 minutes in duration at 65 % VO2peak followed immediately by a 30-minute performance trial. During the first 60-minutes the participants were given four 200 ml dosages (15, 30, 45, 60-min) of an 8% CHO beverage or a taste-matched placebo beverage. Blood lactate and glucose levels were sampled during the 60-minute exercise trial (pre, 20, 40, 60-min) and immediately after the 30-minute performance trial (post, 2, 5, 10-min). Heart rate was monitored continuously during the exercise and performance trial. Expired gas samples were also taken for 5-min periods during the exercise trial and then continuously during the performance trial. These values were used to calculate respiratory exchange ratio (RER) and carbohydrate oxidation. Dietary intake was assessed with a three day food record.<p> No significant differences were apparent between beverage trials for total distance (km), average speed (kmhr-1) or maximum speed achieved (kmhr-1). Significant differences were evident for blood glucose values, RER and CHO oxidation between the two beverage trials (p< .05). At the end of the 30-minute performance trial blood glucose values were significantly higher in the CHO trial (4.8 ± 1.3 mmol.l-1 vs. 4.0 ± 0.5 mmol.l-1 for placebo trial; p< .05). The CHO beverage resulted in higher CHO oxidation during the last 5 minutes of the performance trial, 2.1 ± 1.0 gmin-1 vs. the placebo beverage 1.9 ± 1.0 gmin-1 (p< .05). The CHO beverage trial resulted in significantly higher RER values during the final 5 minutes of the exercise trial and during the final 10 minutes of the performance trial. At the 20-25 minute mark RER values were significantly higher with the CHO beverage trial (1.04 ± 0.10) vs. the placebo trial (1.01 ± 0.11) (p< .05). During the final 5 minutes of the performance trial RER values were also significantly higher with the CHO beverage trial (1.06 ± 0.11) vs. the placebo trial (1.01 ± 0.10) (p< .05). The results indicated the participants were not meeting the current dietary guidelines for able-bodied athletes and active adults. Only 25% of the participants met the daily caloric requirements for active adults. Carbohydrate recommendations of 6 to 10 gkg-1 body weightd -1 were not met by any of the wheelchair athletes Seven participants were within the acceptable macronutrient range (AMDR) for CHO. For protein intake, 63% of the participants were meeting the protein recommendations active adults and all of them were within the AMDR. Average caloric intake from fat exceeded current recommendations of 20 to 25%; two participants were above the AMDR. The results demonstrate that the 8% CHO beverage consumed during exercise resulted in higher CHO oxidation rates and elevated blood glucose values, but it did not result in a performance gain.
93

Health Risk Assessment For The Land Application Of Biosolids In Ankara, Turkey

Kendir, Ece 01 January 2013 (has links) (PDF)
Biosolids are valuable products which can be beneficially used in land application. However, the possibility of serious health effects on humans due to several pollutants in biosolids creates a big concern. To address this issue, risk-based methodologies are commonly used to evaluate health effects associated with the land application of biosolids. This study aims to investigate the health risks associated with ingestion of biosolids or soil mixed with biosolids by a child. This study is the first health risk assessment study in Turkey for land application of biosolids. Monthly sludge samples taken from Ankara Central Wastewater Treatment Plant (ACWWTP) in 2012 were analyzed for seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, and Zn), and two organic contaminants (PCB and NPE) concentrations. To calculate health risks, methodologies developed by U.S. Environmental Protection Agency (U.S. EPA) and French National Institute for Industrial Environment and Risks (INERIS) were used. With both methods, cancer and non-cancer risks for the ingestion by a child pathway were determined and found to be below the acceptable cancer and non-cancer risk levels suggested by U.S. EPA and INERIS. Additionally, same health risk calculations were conducted for sludge and soil limit values provided in Turkish Regulation for the Use of Sewage Sludge in Agriculture (2010) to determine what the maximum health risk would be for the worst case scenario in Turkey. According to the results, even if the concentrations are at the maximum possible regulatory levels, the health risks are still low.
94

Mass Balance Tracer Techniques for Integrating in situ Soil Ingestion Rates into Human and Ecological Risk Assessments

Doyle, James 12 January 2012 (has links)
Quantitative soil ingestion studies employing a mass balance tracer approach have been used to determine soil ingestion rate for use in human health risk assessments (HHRAs). Past studies have focused on soil ingestion in populations living in urban/suburban environments and the results have been highly variable. Moreover, there is a paucity of reliable quantitative soil ingestion data to support human health risk assessments of other lifestyles that may be predisposed to ingesting soil, such as indigenous populations following traditional lifestyles. Thus, the primary objective of the research was to determine if populations following lifestyles typical of traditional land use practices in rural or wilderness areas ingest more soil than populations living in urban or suburban environments. Further, the research investigated the use of alternative mass balance tracers, specifically isotopes of the 238U and 232Th decay series, to reduce soil ingestion estimate variability. Mass balance tracer methods were developed and validated in a pilot canine study, and methods using isotope tracers were adapted to permit quantification of sediment ingestion in the benthic fish Moxostoma macrolepidotum (Shorthead Redhorse Sucker). A pilot human soil ingestion study of 7 subjects from an Aboriginal community in British Columbia was conducted over a 3-week period. The mean soil ingestion rate calculated using the daily means of the 4 elemental tracers with the lowest food-to-soil ratios (i.e., Al, Ce, La, Si) was observed to be approximately 74 mg d-1 (standard deviation 91 mg d-1), The median soil ingestion rate was 60 mg d-1, and the 90th percentile was 196 mg d-1. These soil ingestion rate estimates are higher than those currently recommended for HHRAs of adults, and higher than those obtained in most previous studies of adults. However, the estimates are much lower than the earlier qualitative assessments for subsistence lifestyles (i.e., 330-400 mg d-1). The study results also demonstrated that isotopes of the 238U and 232Th decay series radionuclide are not reliable mass balance tracers for estimating soil ingestion in humans; however, they may be useful for quantifying soil and sediment ingestion in wildlife.
95

Effect of carbohydrate ingestion during exercise on performance measures of wheelchair athletes

Hynes, Heather 23 September 2009 (has links)
The primary purpose of this study was to determine the effect of ingesting an 8% carbohydrate (CHO) beverage during a moderate intensity exercise trial on performance outcomes, fuel utilization and blood glucose levels of wheelchair athletes (spinal cord injury (SC I) or cerebral palsy (CP)). The secondary purpose was to analyze the dietary intake of the eight participants and to determine if they were meeting current sport nutrition guidelines for macronutrients and fluids recommended in the joint position statement developed by the American Dietetic Association (ADA), the American College of Sports Medicine (ACSM) and Dietitians of Canada (DC).<p> Under random, double blind conditions eight athletes (6 males, 2 females); mean age 36 ± 8.5 y with a SCI (n = 7) or CP (n = 1) completed two exercise trials on an adapted stationary hand cycle; each trial was 60 minutes in duration at 65 % VO2peak followed immediately by a 30-minute performance trial. During the first 60-minutes the participants were given four 200 ml dosages (15, 30, 45, 60-min) of an 8% CHO beverage or a taste-matched placebo beverage. Blood lactate and glucose levels were sampled during the 60-minute exercise trial (pre, 20, 40, 60-min) and immediately after the 30-minute performance trial (post, 2, 5, 10-min). Heart rate was monitored continuously during the exercise and performance trial. Expired gas samples were also taken for 5-min periods during the exercise trial and then continuously during the performance trial. These values were used to calculate respiratory exchange ratio (RER) and carbohydrate oxidation. Dietary intake was assessed with a three day food record.<p> No significant differences were apparent between beverage trials for total distance (km), average speed (kmhr-1) or maximum speed achieved (kmhr-1). Significant differences were evident for blood glucose values, RER and CHO oxidation between the two beverage trials (p< .05). At the end of the 30-minute performance trial blood glucose values were significantly higher in the CHO trial (4.8 ± 1.3 mmol.l-1 vs. 4.0 ± 0.5 mmol.l-1 for placebo trial; p< .05). The CHO beverage resulted in higher CHO oxidation during the last 5 minutes of the performance trial, 2.1 ± 1.0 gmin-1 vs. the placebo beverage 1.9 ± 1.0 gmin-1 (p< .05). The CHO beverage trial resulted in significantly higher RER values during the final 5 minutes of the exercise trial and during the final 10 minutes of the performance trial. At the 20-25 minute mark RER values were significantly higher with the CHO beverage trial (1.04 ± 0.10) vs. the placebo trial (1.01 ± 0.11) (p< .05). During the final 5 minutes of the performance trial RER values were also significantly higher with the CHO beverage trial (1.06 ± 0.11) vs. the placebo trial (1.01 ± 0.10) (p< .05). The results indicated the participants were not meeting the current dietary guidelines for able-bodied athletes and active adults. Only 25% of the participants met the daily caloric requirements for active adults. Carbohydrate recommendations of 6 to 10 gkg-1 body weightd -1 were not met by any of the wheelchair athletes Seven participants were within the acceptable macronutrient range (AMDR) for CHO. For protein intake, 63% of the participants were meeting the protein recommendations active adults and all of them were within the AMDR. Average caloric intake from fat exceeded current recommendations of 20 to 25%; two participants were above the AMDR. The results demonstrate that the 8% CHO beverage consumed during exercise resulted in higher CHO oxidation rates and elevated blood glucose values, but it did not result in a performance gain.
96

The Anatomy of Mastication in Extant Strepsirrhines and Eocene Adapines

Perry, Jonathan Marcus Glen 25 April 2008 (has links)
The jaw adductor muscles in strepsirrhines were dissected and their fiber architecture was quantified. Bite force and leverage were estimated using values for physiological cross-sectional area (PCSA) of the jaw adductors and lateral photographs of skulls. Jaw adductor mass, PCSA, fiber length, and bite force scale isometrically to body size. An experiment carried out at the Duke Lemur Center demonstrated that ingested food size also scales isometrically to body size. Folivorous strepsirrhines are characterized by short jaw adductor fibers, uniformly small ingested food size, large masseter and medial pterygoid muscles (in PCSA and mass), and large estimated bite force for their jaw length. Large-bodied folivores have especially large jaw adductors. Small-bodied folivores have especially short jaws, but do not have especially large jaw adductors. Folivores probably can generate large bite forces; they possess short jaws (short bite load arms) and/or large jaw adductor cross-sectional areas. Frugivorous strepsirrhines are characterized by long jaws, large (but variable) ingested food size, large temporalis muscles, and small estimated bite force for their jaw length. Frugivores have long jaw adductor fibers that likely maintain tension during the ingestion of large objects (e.g., fruits). The temporalis is large in frugivores, not because it has superior leverage during incision, but because its fibers likely do not stretch as much at wide gapes as those of the other adductors. Correlations between osteological landmarks and jaw adductor dimensions in strepsirrhines were used to infer jaw adductor dimensions in <em>Adapis parisiensis</em> and <em>Leptadapis magnus</em> (Adapinae) from the Eocene of Europe. Inferred PCSA and lateral photographs were used to estimate bite force and leverage in these adapines. An analysis of shearing quotients was also performed. Inferred jaw adductor mass, PCSA, bite force, and shearing quotients are great in adapines relative to extant strepsirrhines. All anatomical signals suggest a diet rich in tough leaves and other structural plant parts, perhaps with some small fruits. <em>Adapis</em> was likely more folivorous than <em>Leptadapis</em>. / Dissertation
97

Food intake behaviour in advanced cancer implications of taste and smell alterations, orosensory reward, and cannabinoid therapy /

Clarkson, Tristin Dawne Brisbois. January 2009 (has links)
Thesis (Ph.D.)--University of Alberta, 2009. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Food Science and Technology, Department of Agricultural, Food, and Nutritional Science. Title from pdf file main screen (viewed on January 10, 2010). Includes bibliographical references.
98

Multiple-sprint sport exercise and carbohydrate-protein ingestion in humans

Highton, Jamie M. January 2012 (has links)
The aim of the present thesis was to examine the potential for acute carbohydrate-protein (CHO-P) ingestion to enhance performance and recovery from exercise designed to simulate the demands of multiple-sprint sports (MSSs). Chapter 3 of the thesis explored the inter- and intra-day reliability and concurrent validity of non-motorised treadmill ergometry (NMT) for the assessment of short-distance sprint performance [i.e. 10-30 m). There were no significant mean differences between NMT variables recorded on the same day or between days. Ratio limits of agreement indicated that the best agreement was in 20 [1.02 */-=- 1.09) and 30 m [1.02 */* 1.07) sprint times, peak [1.00 */T 1.06) and mean (0.99 */+ 1.07) running speed and step length (0.99 */-=- 1.09) and frequency (1.01 */+ 1.06). The poorest agreement was observed for time to peak running speed (1.10 */* 1.47). Significant differences were observed between NMT and over-ground sprint times across all distances, with times being lower (faster) by approximately 25-30% over-ground. The correlations between NMT and over-ground variables were generally modest (r5 = 0.44 - 0.67), and optimal for time to cover 30 m on Day 2 (rs = 0.8). Chapter 4 sought to examine the efficacy of CHO-P ingestion during 4 h of recovery from the Loughborough Intermittent Shuttle Test (LIST) when compared to CHO matched for energy (ISOEN) or CHO (ISOCHO) in a typical CHO beverage. There were significant increases over time in muscle soreness, and reductions in extensor and flexor peak torque (by approximately 9%, 9% and 8%, and 13 %, 13% and 11% at 60 deg-s-1) and jump performance (10%, 7% and 5%) with the ingestion of CHO-P, ISOEN and ISOCHO, respectively. Beverage type x time interactions were not significant for any of these variables, indicating that changes in each variable were similar for all groups. Decrements in sprint performance assessed on the NMT were typically small and not different between beverage types (<4%), although sprint times over 20 and 30 m remained elevated for 48 h post-exercise. Accordingly, Chapter 4 provided no clear evidence for a benefit of ingesting CHO-P in the hours after exercise to enhance recovery of muscle function and selected performance variables following MSS activity. Chapters 5 and 6 of the thesis aimed to examine the effect of CHO-P ingestion during simulated MSS exercise. In Chapter 5, it was observed that sprint times, HR and gut fullness increased over the course of the LIST, with no influence of consuming each of the different beverages. In contrast, there was a main effect of time (P < 0.001), and drink (P = 0.042) observed for RPE, which was lower (P < 0.001) during the LIST in the CHO-P condition (16.9 ± 1.4) than in either the ISOCHO (17.8 ± 1.1) or ISOEN (17.7 ± 1.3). However, time to exhaustion was not different (P = 0.29) between CHO-P (468.3 ± 268.5 s), ISOCHO (443.4 ± 286.3 s) and ISOEN (446.2 ± 282.08 s), although these times did equate to a non-significant mean improvement of 4% in the CHO-P trial. Chapter 6 demonstrated that during a modified version of the LIST with two self-regulated blocks of exercise intensity, participants had a higher average speed (8.1 ± 0.3 cf. 7.9 ± 0.5 knvlr1) during the final (self-regulated) 15 min block of the LIST in the CHO-P condition compared to CHO. Whilst the mechanisms for such an improvement are not certain, the attenuated rise in RPE observed in Chapter 5, and increased blood urea concentration observed in Chapter 6, with CHO-P ingestion may suggest altered central fatigue and/or increased protein oxidation enhances performance during MSSs.
99

An investigation into the benefits of distributed propulsion on advanced aircraft configurations

Kirner, Rudi 12 1900 (has links)
Radical aircraft and propulsion system architecture changes may be required to continue historic performance improvement rates as current civil aircraft and engine technologies mature. Significant fuel-burn savings are predicted to be achieved through the Distributed Propulsion concept, where an array of propulsors is distributed along the span of an aircraft to ingest boundary layer air and increase propulsive efficiency. Studies such as those by NASA predict large performance benefits when integrating Distributed Propulsion with the Blended Wing Body aircraft configuration, as this planform geometry is particularly suited to the ingestion of boundary layer air and the fans can be redesigned to reduce the detrimental distortion effects on performance. Additionally, a conventional aircraft with Distributed Propulsion has not been assessed in public domain literature and may also provide substantial benefits. A conceptual aircraft design code has been developed to enable the modelling of conventional and novel aircraft. A distributed fan tool has been developed to model fan performance, and a mathematical derivation was created and integrated with the fan tool to enable the boundary layer ingestion modelling. A tube & wing Distributed Propulsion aircraft with boundary layer ingestion has been compared with a current technology reference aircraft and an advanced turbofan aircraft of 2035 technology. The advanced tube & wing aircraft achieved a 27.5% fuel-burn reduction relative to the baseline aircraft and the Distributed Propulsion variant showed fuel efficiency gains of 4.1% relative to the advanced turbofan variant due to a reduced specific fuel consumption, produced through a reduction in distributed fan power requirement. The Blended Wing Body with Distributed Propulsion was compared with a turbofan variant reference aircraft and a 5.3% fuel-burn reduction was shown to be achievable through reduced core engine size and weight. The Distributed Propulsion system was shown to be particularly sensitive to inlet duct losses. Further investigation into the parametric sensitivity of the system revealed that duct loss could be mitigated by altering the mass flow and the percentage thrust produced by the distributed fans. Fuel-burn could be further reduced bydecreasing component weight and drag, through decreasing the fan and electrical system size to below that necessary for optimum power or specific fuel consumption.
100

Effects of water temperature, diet, and bivalve size on the ingestion of sea lice (Lepeophtheirus salmonis) larvae by various filter-feeding shellfish

Webb, Janis Louise 21 December 2011 (has links)
The sea louse (Lepeophtheirus salmonis), whose larvae are planktonic and disseminated in the water column, is an economically important parasite of Atlantic salmon (Salmo Salar). The effect of temperature (5, 10, 15°C), diet (larvae alone, larvae plus phytoplankton), and bivalve size (small, medium, large) on the amount of L. salmonis larvae ingested by various species of filter-feeding bivalves (Pacific oysters, Pacific scallops, blue/Gallo’s mussel hybrids, basket cockles) was examined in a series of laboratory experiments. Four separate temperature/diet experiments were conducted (one for each species) in which large bivalves were individually placed in 2-L containers holding 750 ml of aerated, filtered seawater and fed one of three treatment diets: (1) phytoplankton: ~7.1 x 104 cells ml-1 of Isochrysis sp. (Tahitian strain, TISO); (2) sea lice larvae: ~431 larvae (mostly nauplii); and (3) phytoplankton and larvae (at the levels mentioned above). There was also a control treatment of phytoplankton and larvae, but no bivalve. After feeding for 1 h, the bivalve soft tissues were excised and preserved, the digestive system was dissected, and sea lice larvae were removed and counted to provide direct evidence of ingestion. The larvae remaining free swimming in the container were iv preserved and counted. The proportion missing from the container was used to estimate ingested larvae in statistical analyses. Two additional experiments investigating the effect of bivalve size (small, medium, large) on the ingestion of sea lice larvae were conducted with Pacific oysters and Pacific scallops. The heights for oysters (anterior-posterior axes) were 19.2, 44.2, and 84.0 mm, and scallops (dorsal hinges to ventral margins) were 40.3, 64.1, 102.7 mm. The methodology for the size experiments was as previously described for the temperature/diet experiments with the following changes: (1) the diet of larvae alone was not used; (2) the mean number of larvae in each container was ~498; (3) the mean concentration of TISO added to each container was ~7.8 x104 cells ml-1, and (4) the mean water temperature was 10.4°C. The data for the four temperature/diet experiments indicate that all four bivalve species ingested sea lice larvae, whether their diet included phytoplankton or not, and that temperature had no significant effect. The data for the two size experiments indicated that all three sizes of oysters and scallops ingested sea lice larvae and that there was a significant size effect. Large shellfish consumed a significantly greater proportion of the sea lice larvae than the small shellfish. Bivalves grown at salmon net pens as part of an IMTA (Integrated Multi-Trophic Aquaculture) system may be able to reduce the number of sea lice larvae as well as being an additional crop of market value. Future research, conducted at a commercial scale at a salmon farm, is warranted in order to determine if bivalves can serve in this role. / Graduate

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