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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.
211

The effects of sports drinks containing caffeine and carbohydrate on soccer-specific skill performance during match-induced fatigue

Jacobson, Marc A. 26 April 2011 (has links)
A ninety minute competitive soccer match consists of many intermittent sprints resulting in fatigue, and consequently, a reduction in skill performance. The combination of caffeine and carbohydrate (CHO) has been shown to have ergogenic effects which help maintain skill measures during fatiguing states, however, there has been little research investigating this combination on soccer performance. Therefore, the aim of this study was to examine the effects of three sports drinks, including a placebo (PLA), a 6% CHO drink, and CHO + caffeine (CCAF; 5 mg/Kg body mass (BM)) on soccer-specific skills, throughout a fatigue-inducing soccer match. Twelve male soccer players completed three ninety minute intersquad matches played outdoors on a grass field in a randomized crossover design. Players consumed 5 ml/kg BM 45 minutes prior to kickoff and 3 ml/kg BM every 15 minutes during match play. Soccer passing skill was measured using the Loughborough Soccer Passing Test (LSPT), shot speed, and 20m sprint performance were measured pre-match, immediately at halftime and immediately post-match. Countermovement jump (CMJ) was measured pre-match and post-match. Heart rate (HR) was measured continuously. Blood lactate, rating of perceived exertion (RPE), and perceived fatigue were assessed every fifteen minutes throughout the match. Urine was collected pre-match for analysis of urine specific gravity (USG). BM was measured pre-match and post-match. LSPT total performance time was significantly better in the CCAF trial compared to the PLA trial at halftime (55.3 ± 10.3 s vs 66.5 ±8.7 s, p = .027). There were also significant improvements in penalty time (CCAF 8.2 ± 7.6 s vs. PLA 16.6 ± 7.8 s, p = .042) and movement time (CCAF 8.2 ± 7.6 s vs. PLA 16.6 ± 7.8 s, p = .028) during the CCAF trial in comparison to the PLA at halftime. HR and blood lactate was elevated throughout the PLA trial in comparison to the CHO trial. There were no other significant findings. Most players (50% - 83%) started all three matches in a dehydrated state (USG > 1.020). The CHO trial had significantly lower sweat rates (0.83 ± 0.25 L/hr) than both the PLA trial (1.06 ± 0.26 L/hr, p = .038) and the CCAF trial (1.11 ± 0.19 L/hr, p = .009). The addition of caffeine to a CHO sports drink significantly improved passing performance (quicker completion time and fewer penalties accumulated) over a PLA. All three sports drinks appeared to be equally as effective in preventing deterioration of soccer skill performance during a game situation. This suggests that the total volume of fluid consumed is of greater importance than the type of fluid. Caffeine appeared to have limited ergogenic effects on skill performance without any negative consequences. / Graduate
212

Artificial Nutrition and Hydration for Infants with Life-Terminating Conditions: Rethinking the Catholic Position

Uhl, L William 01 December 2011 (has links)
Infants with life-terminating conditions (ILTCs) are those whose conditions prevent them from living more than two years. When these infants have difficulty assimilating food and fluids orally, doctors can provide nutrition and hydration through artificial means. While artificial nutrition and hydration (ANH) can provide benefits, it can also result in complications leading to pain and/or distress in addition to that which an ILTC may already be experiencing from one or more underlying conditions. Many medical experts maintain that withholding or withdrawing ANH can help a patient’s body produce its own analgesics. I consider four categories of ILTCs: 1) infants who receive prognoses of two weeks or less; 2) infants who will live longer than two weeks but no more than two years and who are not suffering or in distress; 3) infants who are not dying, but are in distress from the use of ANH; and 4) infants who are not dying, but are in distress from their conditions and/or ANH. I argue that in addition to providing natural analgesics, withholding or withdrawing ANH is a form of comfort care that prevents the occurrence of further complications requiring additional medical treatments and keeps ILTCs content. Under certain circumstances, the withholding or withdrawing of ANH should be obligatory. As it stands, the whole of Catholic teaching on ANH is inconsistent. Operating from the sanctity-of-life ethic, the Church teaches that ANH is an ordinary, therefore obligatory, form of care. But this position contradicts the view that any form of care presenting a grave burden to a patient and/or his family is extraordinary and therefore optional. In addition, by making ANH obligatory, the Catholic Church causes families to undergo heroic suffering (i.e., enduring more than what can be expected or asked of anyone), which the Church says is not required of everyone. I argue that rethinking the Catholic position on ANH will enable the Church to offer practical moral guidance for families to comfort ILTCs, help ILTCs and their families avoid heroic suffering, and provide spiritual care families of ILTCs need, all while still respecting the sanctity of life of every person.
213

Characterization of air voids in fresh cement paste through ultrasonic nondestructive testing

Kmack, Richard Matthew 10 July 2008 (has links)
The objective of this research is the pursuit of a better characterization method for the air voids - particularly air-entrained voids - in fresh cement-based materials through the use of ultrasonics. The use of air-entraining agents (AEA's) to incorporate a stable network of air voids into fresh cement paste is common practice in the concrete industry. These particular air voids significantly improve durability of hardened cement paste through mitigation of stresses associated with freezing and thawing cycles. It is understood that the performance of entrained air voids in cement paste is dependent on their size and distribution, or spacing factor. However, conventional methods for qualifying air content, such as the Pressure, Volume, and Gravimetric Methods, only measure total air volume and cannot assess size or spacing. In this investigation, using matched pairs of transducers, ultrasonic pulses were transmitted through fresh cement paste specimens (0.0\% up to 0.6\% AEA by weight of cement). The received signals were recorded every five minutes during the first six hours and then every fifteen minutes thereafter. Analysis shows strong distinctions between specimens with and those without the AEA. Further research is needed into the distinctions among specimens with the AEA. However, the data suggest correlations between Vicat setting times, heat of hydration, and autogenous strain and ultrasonic metrics such as pulse velocity and peak frequency of the signal. The findings of this research should be most appropriate as a foundation for an inversion process and improved air-entrainment detection methods.
214

A Computational Study of the Role of Hydration in the Assembly of Collagen and Other Bio laments

Mayuram Ravikumar, Krishnakumar 2011 August 1900 (has links)
Hydration is known to be crucial in biomolecular interactions including ligand binding and self-assembly. In our earlier studies we have shown the key role of water in stabilizing the specific parts of the collagen triple helix depending on the imino acid content. We further showed that the primary hydration shell around collagen could act as a lubricating layer aiding in collagen assembly. But key details on the structure and dynamics of water near protein surfaces and its role in protein-protein interactions remain unclear. In the current study we have developed a novel method to analyze hydration maps around peptides at 1-A resolution around three self-assembling lament systems with known structures, that respectively have hydrated (collagen), dry non-polar and dry polar (amyloid) interfaces. Using computer simulations, we calculate local hydration maps and hydration forces. We find that the primary hydration shells are formed all over the surface, regardless of the types of the underlying amino acids. The weakly oscillating hydration force arises from coalescence and depletion of hydration shells as two laments approach, whereas local water diffusion, orientation, or hydrogen bonding events have no direct effect. Hydration forces between hydrated, polar, and non-polar interfaces differ in the amplitude and phase of the oscillation relative to the equilibrium surface separation. Therefore, water-mediated interactions between these protein surfaces ranging in character from ‘hydrophobic’ to ‘hydrophilic,’ have a common molecular origin based on the robustly formed hydration shells, which is likely applicable to a broad range of biomolecular assemblies whose interfacial geometry is similar in length scale to those of the present study. In a related study through simulations we show that the rate of tissue optical clearing by chemical agents correlated with the preferential formation of hydrogen bond bridges between agent and collagen. Hydrogen bond bridge formation disrupts the collagen hydration layer and facilitates replacement by a chemical agent to destabilize the tertiary structure of collagens thereby reducing light scattering. This study suggests that the clearing ability of an alcohol not only depends on its molecular size, but also on the position of hydroxyl groups on its backbone.
215

Multiwavelength fluorescence studies of Bacillus bacterial spores

Sarasanandarajah, Sivananthan January 2007 (has links)
Fluorescence techniques are being considered for the detection and identification of bacterial spores. This thesis sets out to empirically characterize the detailed autofluorescence spectroscopic properties of spores and their target molecules. The multiwavelength fluorescence studies from a unique endogenous biomarker, dipicolinic acid (DPA) and its calcium salt (CaDPA) in bacterial spores are found to be useful for fluorescence characterization of spores. A systematic determination of the fluorescence profile of the major chemical components of Bacillus spores and the effect of UV irradiation on them has been performed in dry samples, wet paste and in aqueous solution. The thesis applies reliable tools for accurately describing complex nature of spectral profile from bacterial spores, and for interpreting and identifying their spectral properties. We show that multiwavelength fluorescence technique combined with Principal Component Analysis (PCA) clearly indicates identifiable grouping among dry and wet Bacillus spore species. Differences are also observed between dried, wet and redried spores, indicating the stark effect of hydration on fluorescence fingerprints. The study revealed that changes in fluorescence of spores due to hydration/drying were reversible and supports a recent model of a dynamic and dormant spore structure. The spectra were analysed with PCA, revealing several spectroscopically characteristic features enabling spore species separation. The identified spectral features could be attributed to specific spore chemical components by comparing the spore sample signals with spectra obtained from the target molecules. PCA indicated underlying spectral patterns strongly related to species and the derived components were correlated with the chemical composition of the spore samples. More importantly, we examined and compared the fluorescence of normal spores with a mutant of the same strain whose spores lack DPA. We discovered that the dramatic fluorescence enhancement of Bacillus spores can be caused by UV irradiation in the spectral region of this unique biomarker without any pre treatment. Differences between spectra of spores, spore strains and other biological samples are very marked and are due to the dominance of the dipicolinate features in the spore spectra. This could lead to a cheap, more sensitive, faster and reagentless bacterial spore detector.
216

Carcass and eating quality of sheep grazing saltbush based saline pasture systems

k.pearce@murdoch.edu.au, Kelly L Pearce January 2006 (has links)
Forage halophytes such as saltbush (Atriplex spp) are being widely used to revegetate Australian saline land and can also provide a medium quality fodder source. There is widespread anecdotal evidence that sheep grazing on saltbush are leaner, tastier and juicer. This thesis investigated the potential to produce a high quality carcass with improved eating quality from grazing sheep on saltbush on saline land. The first experimental chapter in this thesis details an animal house experiment investigating the carcass, eating and wool quality and physiological responses of sheep ingesting a 60:40 dried saltbush (Atriplex nummularia):barley grain (S+B), ration verses a 33:25:42 lupin grain:barley grain:oaten hay ration (Control, C) for 10 weeks prior to commercial slaughter (Chapter 4). Subsequently, two field experiments were conducted to examine the effects of grazing saltbush on saline land compared to dry senesced pasture on carcass and eating quality of lambs (Goomalling 2003) and hoggets (Wickepin 2004) (both chapter 6) for 14 weeks. Both chapters demonstrated that the ingestion of saltbush resulted in significantly less fat and in the 2 field experiments the ingestion of saltbush resulted in more lean on the carcass compared to sheep grazing a stubble/pasture (control) ration. These are positive findings for processors as costs of fat denudation are high so the lower the fat content and for farmers because less fat is deposited on the carcass per unit of liveweight gain. The decreased deposition of fat was attributed to the higher protein:energy ratio available for production, secondary compounds in saltbush and lower circulating insulin and higher growth hormone of the S+B fed sheep compared to the control fed sheep. Further work is needed to determine if these beneficial improvements in carcass composition can be achieved without compromising animal production. The long term grazing of saltbush did not result in commercially desirable hot carcass weights unless the sheep were supplemented with a high energy source such as barley. The low growth rates are attributed to a decreased availability of energy substrates, low feed intake and increased energy output of sheep fed high salt diets. The low energy intake of the S+B fed sheep also resulted in an a significantly lower percentage of unsaturated fat and unchanged levels of saturated fat in the fat depots compared to the C treatment. Consumer taste tests conducted on meat from experiments in both chapter 4 and 6 indicated no difference between the treatments for any of the eating quality traits assessed. This can be considered a positive result as sheep can be finished on saltbush without any detriment to eating quality. High vitamin E levels in the meat may have also prevented the development of rancid flavours and aroma. It can be speculated that saltbush does not impart beneficial flavour and aroma volatiles as previously thought; instead the high vitamin E levels inhibit off-flavour and aroma development compared to meat from sheep grazed on dry pasture. The long term ingestion of saltbush also resulted in significantly lower urine specific gravity (USG), muscle dry matter and higher urine weights suggesting that the saltbush fed sheep had a better hydration status compared to control fed sheep. However, this finding did not correspond with higher hot carcass weight or dressing percentages. The increases in muscle fluid content of the saltbush fed sheep were attributed to changes in body composition. The saltbush fed sheep had a higher lean and lower fat content which corresponded with a greater body fluid content as found in the animal house study. Under conditions where the body composition of sheep remains the same, the use of short term strategic feeding of components of saltbush was investigated (mimicked in the form of salt and betaine) to reduce dehydration and subsequent reductions in carcass weight and dressing percentages (Chapter 7). Salt and or betaine were fed for 1 week either prior to a 48 h period of water deprivation or prior to 48 h commercial slaughter process where water was available in lairage from 24-48 h. Under both scenarios the diets did not result in improved dressing percentages, hot carcass weights, muscle dry matter or muscle weights. The ingestion of high salt diet prior to slaughter, did increase fluid retention in the extracellular spaces prior to slaughter however by 48 h both groups were at a similar physiological and therefore similar hydration status. Therefore similar levels of fluid were present in the muscles and no difference in carcass weight or dressing percentage could be expected. An important observation from the second experiment was that the high salt group drunk more water than the low salt fed sheep but the low salt group consumed fluid in lairage also. The low salt fed sheep may have been encouraged to drink water after observing the frequent drinking patterns of the high salt group. This thesis has also shown that saltbush contains high levels of vitamin E (á-tocopherol) (193 mg/kg dry matter). As a result the concentration of á-tocopherol in plasma, liver and muscle of the saltbush fed sheep was elevated compared to those grazing dry pasture. The high muscle concentrations of vitamin E in the saltbush-grazed sheep resulted in improved meat colour stability. The high vitamin E levels did not influence the drip and cooking loss of the meat despite a decrease in the muscle dry matter of the meat. The browning of meat and increased drip loss results in large losses to the meat industry due to value deterioration at the supermarket. There is also great potential for the high vitamin E content in saltbush to be used for the prevention of nutritional myopathy instead of using expensive and labour intensive synthetic supplements. In conclusion, this thesis has provided an insight into the carcass and eating quality of sheep grazed on saltbush based saline pasture systems. The most significant findings were that
217

Thermodynamics of aqueous electrolytes and hydrogen-bonded non-electrolytes over a wide range of temperature and pressure : the aqueous trivalent lanthanide cations and the methanol-water system /

Xiao, Caibin, January 1997 (has links)
Thesis (Ph. D.) --Memorial University of Newfoundland, 1997. / Restricted until November 1998. Bibliography: leaves 264-281.
218

Modelle zur Kinetik der Hydratation von Calciumaluminatzement mit Calciumsulfat aus kristallchemischer und mineralogischer sicht

Götz-Neunhoeffer, Friedlinde. January 2006 (has links)
Thesis (Habilitationsschrift)--Friedrich-Alexander-Universität Erlangen-Nürnberg. / Includes bibliographical references (p. 225-232).
219

Predicting temperature rise and thermal cracking in concrete

Robbins, Michael Edward. January 1900 (has links)
Thesis (M.A.)--University of Toronto, 2007. / "PCA R&D Serial No. 3030." (cover)
220

CARACTERIZAÇÃO DA FIBRA DE CO-PRODUTOS AGROINDUSTRIAIS E SUA AVALIAÇÃO NUTRICIONAL PARA COELHOS EM CRESCIMENTO / FIBER CARACTERIZATION OF AGRICULTURAL BY-PRODUCTS AND ITS NUTRITIONAL EVALUATION FOR GROWING RABBITS

Retore, Marciana 26 February 2009 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Two experiments were carried out in Rabbit Laboratory of Animal Science Department at Federal University of Santa Maria, RS, where were studied the influence of different fractions of fiber from agricultural by-products (citrus pulp, soybean hulls, linseed bran and corn gluten meal) on performance, digestibility coefficients, blood parameters and meat quality of rabbits submitted to diets. The diets were isoproteic and isoenergetic, 18% of crude protein and 3,000 kcal/kg of digestible energy, respectively. Eight New Zealand White rabbits were utilized to each treatment, from 40 to 89 days of age. At the first experiment, the treatments were: AHcontrol diet, with alfalfa hay; CP- total substitution of alfalfa hay by citrus pulp and SH- total substitution of alfalfa hay by soybean hulls. The animals of the treatments CP and SH showed similar performance, carcass weight and carcass dressing percentage to the animals of the treatment AH. The DM, OM, CP and NDF apparent digestibility coefficients were superior for the diet SH, due to fiber quality. Reductions on triglycerides, cholesterol, hemoglobin and glucose levels were observed in the blood of the animals fed with citrus pulp, because of the high cation-exchange capacity of this by-product. Meat tenderness was higher for those animals that consumed the diet with soybean hulls, due to better nutrients digestibility. The different fiber fractions from citrus pulp and soybean hulls do not affect animals performance and weight and dressing carcass, showing that these ingredients can substitute the alfalfa hay on rabbits diet. Fiber quality of citrus pulp decrease animals blood triglycerides and cholesterol levels. The lower amount of lignin in relation to cellulose and hemicellulose of the soybean hulls provides better nutrients digestibility coefficients. At the second experiment the treatments were: AH- control diet, with alfalfa hay; LB- total substitution of alfalfa hay by linseed bran and GM- total substitution of alfalfa hay by corn gluten meal (20% of crude protein). The animals from GM treatment showed similar performance in relation to the ones from AH treatment, although the carcass dressing percentage did not differ among the byproducts. Linseed bran proportioned lower performance, due to higher fiber hydration capacity and gel formation. The DM, OM, CP and NDF apparent digestibility coefficients were superior for GM treatment, due to fiber quality. Meat tenderness was higher for those animals that consumed the diet of the treatment GM because of the better digestibility coefficients. Corn gluten meal can substitute alfalfa hay on rabbits diet. Linseed bran, due to high amount of soluble fiber and high hydration capacity, affects animal performance and meat tenderness. / Dois experimentos foram realizados no Laboratório de Cunicultura do Departamento de Zootecnia, da Universidade Federal de Santa Maria, RS, onde se estudou a influência das diferentes frações de fibra advindas de co-produtos agroindustriais (polpa de citros, casca de soja, farelo de linhaça e farelo proteinoso de milho) sobre o desempenho, coeficientes de digestibilidade, parâmetros sanguíneos e características da carne de coelhos submetidos às dietas. As dietas foram isoprotéicas (18% PB) e isoenergéticas (3000 kcal/kg ED). Foram utilizados oito coelhos da raça Nova Zelândia Branca por tratamento, testados dos 40 aos 89 dias de idade. No primeiro experimento, os tratamentos foram: FA- ração controle, com feno de alfafa; PC- substituição total do feno de alfafa por polpa de citros e CS- substituição total do feno de alfafa por casca de soja. Os animais dos tratamentos PC e CS apresentaram desempenho, peso e rendimento de carcaça semelhantes aos animais do tratamento FA. Os coeficientes de digestibilidade aparente da MS, MO, PB e FDN foram superiores para a dieta com casca de soja, em função da qualidade de fibra deste ingrediente. Foi observado redução nos níveis séricos de triglicerídeo, colesterol, hemoglobina e glicose dos animais alimentados com polpa de citros, devido à alta capacidade de ligação catiônica deste co-produto. A maciez da carne foi superior para os animais que consumiram a dieta com casca de soja, em virtude da melhor digestibilidade dos nutrientes. As diferentes frações da fibra advindas da polpa de citros e casca de soja não afetam o desempenho dos animais e o peso e rendimento de carcaça, mostrando que estes ingredientes podem substituir o feno de alfafa na dieta de coelhos. A qualidade de fibra da polpa de citros reduz os níveis séricos de triglicerídeo e colesterol dos animais. A baixa quantidade de lignina em relação à celulose e hemicelulose da casca de soja propicia melhores coeficientes de digestibilidade dos nutrientes. No segundo experimento, os tratamentos foram: FA- ração controle, com feno de alfafa; FL- substituição total do feno de alfafa por farelo de linhaça e FP- substituição total do feno de alfafa por farelo proteinoso de milho (20% PB). Os animais do tratamento FP apresentaram desempenho semelhante aos animais do tratamento FA. Porém, o rendimento de carcaça não diferiu entre os co-produtos testados. O farelo de linhaça proporcionou desempenho inferior aos demais ingredientes, devido à alta capacidade de hidratação da fibra e formação de gel. Os coeficientes de digestibilidade aparente da MS, MO, PB e FDN foram superiores para o tratamento FP, em função da qualidade de fibra. A maciez da carne foi superior para os animais que consumiram a dieta do tratamento FP, em virtude da melhor digestibilidade dos nutrientes. O farelo proteinoso de milho pode substituir o feno de alfafa na dieta de coelhos. O farelo de linhaça, pela grande quantidade de fibra solúvel e alta capacidade higroscópica, prejudica o desempenho dos animais e maciez da carne.

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