5 pp. / Winter cereals such as barley, oats, triticale, and wheat are commonly grown as forage for the dairy industry. The purpose of this study is to generate information on yield potential of various winter cereal forage varieties. A trial testing the yield potential of eleven winter cereal forage entries including barley, oat, triticale, and wheat varieties was established at the Maricopa Ag Center on October 16, 2015. Forage yields were obtained at cuttings on December 10, February 29, and April 18. The highest yielding entry at the first cutting was Stockford barley. At the second and third cuttings, the highest yielding entry was Summit 515 wheat. Summit 515 wheat was also the highest yielding entry averaged over all cuttings. As a group, the wheat entries were higher yielding that the other winter cereals except at the first cutting where the barleys were higher yielding.

[pt] Efetuou-se um estudo numérico do escoamento entre cilindros concêntricos e excêntricos girantes com efeitos de dissipação viscosa presente. Assumiu-se que o cilindro interno estava girando com uma velocidade angular constante e que o externo estava fixo. Assumimos a condição de contorno de não deslizamento para velocidade em ambas as paredes. A temperatura do fluido nas paredes dos cilindros foi assumida constante e seu campo assumimos ser governado por efeitos de convecção e condução, com uma fonte de energia proveniente da dissipação viscosa do escoamento. A viscosidade do fluido foi assumida variável com a temperatura. A discretização espacial foi feita por elementos finitos através de funções de base lineares, mais uma função estabilizadora para velocidade no caso dos cilindros excêntricos. O método das características foi usado no problema excêntrico. Resultados computacionais ilustram a eficiência da técnica adotada. / [en] A computational study of viscous flow between concentric and eccentrically rotating cylinders in presented in which the effect of viscous dissipation is taken into account. The inner cylinder is assumed to be rotating at constant speed with respect to the outer one. We assume a no-alip boundary condition for the velocity on both walls. The temperature of the fluid is assumed to be constant on the cylinders and its distribution is assumed to be governed by both conduction and convection, with a supplementary soure of energy du to the effects of viscous dissipation. The viscosity is assumed to be varies with temperature. The space discretization is based on piecewise linear finite elements, with velocity stabilization in case of the eccentrically cylinders. The method of characteristics is used for time integration in the eccentrically problem. Numerical results illustrate the efficienty of the adopted approach.

[pt] Neste trabalho foi utilizado o método dos volumes de controle para solução das equações de balanço de massa, momentum e energia, relativas ao escoamento de ar através de um canal. Este é formado por duas paredes verticais, planas, paralelas e adiabáticas. A dissipação de calor, através de um elemento retangular isotérmico adjacente a uma das paredes, provoca a convecção natural. O pioneirismo está na utilização da condição de contorno de pressão para a solução de uma equação, que corrige s velocidades neste mesmo contorno, permitindo utilizar as equações de momentum em forma elíptica. É investigado o comportamento do número de Nusselt médio do canal para Rayleigh variando do Ra igual 153 a Ra igual 1223, com o elemento posicionado no início, no meio e no fim do canal, variando-se as aberturas do mesmo. Verifica-se também o comportamento do Nusselt local ao redor do elemento, assim como o campo de velocidade. Foi verificada a existência de uma distancia ótima entre as paredes do canal, para cada valor do número de Rayleigh. Conclui-se, portanto, que a geometria do elemento tem um efeito importante no processo de transferência de calor, não devendo ser desprezada. / [en] The control volume method was used to solve numerically the equations related to mass, momentum and energy balance. Air flows trough a channel formed by two vertical, flat, parallel and adiabatic walls. The natural convection was caused by a retangular Isothermal element attached to one of the walls. The innovation of this work lies in the utilization of the momentum equations in its elliptical form. It was achieved using the pressure boundary condition to solve an equation that corrects the boundary velocity. The variation of the medium Nusselt number was insvestigated from Ra equal 153 to Ra equal 1223, attaching the element in three diferent positions: at the beginning, in the middle, at the end of the channel and varyin the distance between the walls. The local Nusselt number and the velocity Field around the element were also studied. An optimum distance between the walls for each Rayleign number was that the geometry, of the element has a decisive effect on the heat transfer process, and so it must not be neglected.

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This thesis presents three essays on global yield curve factors and international linkages across yield curves. The essays represent a contribution to our understanding of the effect of globalization on yields, addressing three topics: modeling global and local yield curve factors, modeling global and local yield curve factors in excess bond returns and a joint model of global macroeconomic and yield curve factors. The first essay proposes and develops an empirical model of global and local yield curve factors based on three factors proposed by Nelson and Siegel (1987) dynamized and reinterpreted by Diebold and Li (2006) as level, slope and curvature. The results support the existence of a global yield curve composed of global factors which together with local factors describe the yield curve of the USA, Germany and the UK. Specifically, the global factors explain on average 55% of the variance of yields, and impulse response functions indicate that shocks to global factors are larger and last longer than shocks to local factors. In the second essay, we examine the predictability content of the global and local yield curve factor model to predict excess bond returns one year ahead. We use a rolling window of fifteen years to compare in-sample predictability of our model and two benchmark models: the model proposed by Cochrane and Piazzesi (2005) and the global and local factor model proposed by Dahlquist and Hasseltoft (2011). The results indicate that the global and local yield curve factors from our model predict excess bond returns with an adjusted R² up to 59%. We also find that global factors explain up to 58% of the forecast error variance when predicting excess bond returns. Moreover, our model outperforms both competing models considering the USA, Germany and the UK.The third essay proposes and estimates a joint model of global macroeconomic and yield curve factors, which shows the interaction between global yield curve factors and global macroeconomic factors. Our findings show that the influence of macroeconomic factors on yield curve factors is stronger than the influence of yield curve factors on macroeconomic factors.

The pattern of post-partum and ovarian activity was monitored in two herds through the use of radioimmunoassay of progesterone in post-milking strippings. The University of British Columbia, South Campus (UBC) herd was sampled on a twice weekly basis, while the Agriculture Canada Research Station, Agassiz herd was sampled every second day. Sampling began approximately six days post-partum and continued up to 60 days post-conception. The estrous cycle was classified into phases based on the concentration of progesterone in the milk samples. Progesterone concentration immediately post-partum and for a varying length of time thereafter remained at basal levels. This was classified as Phase 0 and represented the stage of quiescence in the ovaries post-partum. Phase 1 of the estrous cycle represented the follicular stage when the concentration of progesterone was low. Phase 2 represented the stage when the corpus luteum was developing and the concentration of progesterone was rising. Phase 3, the fully active corpus luteum stage, was when the concentration was highest, while Phase 4 represented the regressing corpus luteum stage when the concentration was falling. The stage of quiescence, from parturition to the initiation of luteal activity was found to be 21.43 ± 11.84 days for 54 animals in the UBC herd and 19.81 ± 8.85 days for 127 animals in the Agassiz herd. Retained placenta increased the duration of quiescence to 25.62 ± 12.41 days for the 12.6% or 16 animals having the condition in the Agassizherd. The 9.3% or five animals having retained placenta in the UBC herd had a much shorter stage of quiescence of 10.80 ± 6.42 days. Two distinct types of first cycles were found, based on the mean concentration of progesterone and the number of days in the period. A normal first cycle exhibited more luteal activity during Phase 3, and remained in this Phase longer than did the shortened first cycle. This may be associated with follicle luteinization in the shortened first cycle rather than true ovulation as in the normal first cycle. The increased frequency of sampling of the Agassiz herd tended to give a more accurate classification of the phases of the cycle as defined, with more Phase 4 samples being identified. Also days in Phase 1 and Phase 2 for both Type 1 (shortened first cycle), and Type 2 (normal first cycle), were approximately half of those observed from the UBC herd. Standard curves of progesterone concentration vs. time for "normal" cycles of various lengths with standard deviations were derived from the pooling of all cycles classed as normal first cycles and normal cycles without a breeding. These "normal" cycles showed that as the cycle length increased, so did time spent during Phase 1 when the concentration of progesterone remained below 4 ng/ml milk. Progesterone profiles of various animals are included, illustrating the wide variety of profiles found. These include profiles of short stages of quiescence, long stages of quiescence, short cycles, long cycles as well as some abnormalities observed. When used as a test for early detection of pregnancy, a single sample from days 21 to 24 for the UBC herd showed accuracies of 100% in determining non-pregnancy and 86% in determining pregnancy. Test results for days 21 and 22 for the Agassiz herd were again 100% accurate for determining non-pregnancy and 90.5% accurate in determining pregnancy. The accuracy of the non-pregnant determination can be increased by including a sample on day of insemination and eliminating those animals inseminated at an obviously incorrect time. With the two sample test on the combined UBC data the accuracy of the pregnant diagnosis increased to 91.5%. On the combined Agassiz data the two sample test increased the accuracy of the pregnant diagnosis to 93.1%. The use of progesterone pregnancy testing offers a considerable saving in time in identifying those animals not conceiving to insemination and a reasonably accurate means of early detection of pregnancy. The average number of days from conception to positive palpation was 51.02 ± 13.19 days for 97 animals in the Agassiz herd and 60.43 ± 23.59 days for the 42 animals in the UBC herd. / Land and Food Systems, Faculty of / Graduate

Acetonemia is a metabolic disorder common among dairy cattle in the period from 10 days to six weeks post partum. It is during this time that milk production is at its maximum and in addition, the cow is beginning to exhibit regular estrous cycles. Thus, the profound demands for the precursors of milk production are superimposed upon a relatively unstable endocrine environment. The initial objective of this study was a clarification of the interactions between estrogens and endogenous substrates of glucose metabolism in the lactating cow. Since estrogen levels during the bovine estrous cycle had not been convincingly reported at the outset of this work, their measurement was the subject of the first experiment. Both estradiol and estrone exhibited peaks on the two days prior to the day of standing heat. These findings were later substantiated with the appearance of reports where plasma estrogen levels were measured by competitive protein binding and radioimmunoassay. A significant decline in plasma amino nitrogen concentration occurred after the estrogen peak, the decrease being reflected in marked reductions in the concentrations of threonine, methionine, proline and the branched chain amino acids. A notable hypoglycemia occurred somewhat later than the decline in amino acids. These findings were rationalized in terms of increased uterine and mammary uptake and/or decreased tissue mobilization of amino acids which may have given rise to the hypoglycemia as a result of decreased availability of glucogenic substrate. A possible mechanism of decreased tissue mobilization of amino acids was considered to be the inhibition by estrogens of adrenal glucocorticoid output, since glucocorticoids play a major role in regulating amino acid balance in peripheral tissues. In addition, the efficacy of glucocorticoid therapy in the treatment of bovine acetonemia is well recognized. With these considerations in mind, the role of estrogens in the modification of ACTH-stimulated glucocorticoid secretion was assessed in two further experiments. Following suppression of endogenous ACTH secretion by dexametha-sone, both estrogen treated and non-estrogen treated cows were subjected to stimulation with incremental doses of exogenous ACTH. At all levels of ACTH stimulation, estrogen treatment resulted in reduced response when measured in terms of plasma glucocorticoid concentrations. However, estrogen treatment had no effect on plasma binding of glucocorticoids. The concentrations measured were, therefore, a direct reflection of glucocorticoid activity. In the second experiment to test adrenal inhibition by estrogens, plasma ACTH and glucocorticoid levels were measured during the estrous cycles of lactating cows. For this purpose, a radioimmunoassay for ACTH was developed, providing a sensitive, reproducible method for the measurement of this hormone in bovine plasma. A significant increase in circulating ACTH concentration was seen during the estrogenic phase of the estrous cycle. No such increase was noted in the concentration of glucocorticoids, levels fluctuating within the normal, low range. This result implied that during the estrogenic phase of the estrous cycle, inhibition of glucocorticoid secretion by estrogens resulted in a compensatory rise in circulating ACTH concentration, bringing the glucocorticoid level back to normal. The results of these experiments are discussed with reference to the possible role of alterations in endocrine balance in the etiology of bovine acetonemia. / Land and Food Systems, Faculty of / Graduate

MSCPNT / Department of Food Science and Technology / The study aimed to determine the physicochemical properties, extract and characterise pectin from three varieties (green, purple and orange) of prickly pear (Opuntia spp) fruit peel. Research samples were collected from Bothlokwa Mphakane village in Limpopo province of South Africa. The experimental design for this study was randomized complete block design and each treatment was conducted in triplicate. Pectin was extracted using sulphuric acid at four different pH levels (1, 2, 3 & 4) and microwave power levels (low, medium & high). The characterisation of extracted pectin was done by calculating the ash, moisture, equivalent weight, anhydrouronic acid, methoxyl content, and degree of esterification. Functional groups present in extracted and commercial pectin were investigated for similarities using Fourier Transform Infrared Spectroscopy. The yield of pectin for purple ranged from 2.9% to 13.8%, orange from 1.4% to 9.8% and from 2.3% to 10.0% for green prickly pear peel. A decrease in pH resulted in an increased pectin yield and an increase in microwave power level increased the pectin yield. Maximum yields of 13.8% on purple, 10.0% on green and 9.8% on orange were obtained at pH 1.0 and medium power level. The best condition for extraction using sulphuric acid was at a medium power level and pH 1.0. The pectins obtained were compared against each other in terms of yield, physicochemical characteristics and chemical structure. The ash content of the extracted pectin was significantly higher at 25.16 ± 0.69, 34.26 ± 1.92 and 36.30 ± 1.07, however the pectin showed lower moisture content and equivalent weight. The methoxyl contents were 2.28 ± 0.26, 2.38 ± 0.21 and 3.86 ±0.31, anhydrouronic acid contents were 25.58 ± 2.03, 25.93 ± 2.35 and 38.84 ± 2.29, and degree of esterification were 49.87 ± 0.17, 50.63 ± 4.76 and 56.39 ± 1.60 across the orange, purple and green varieties, respectively. The prickly pear peel pectin spectra exhibited similarities in its absorption pattern to that of commercial citrus pectin. Therefore, the extraction of pectin from prickly pear peels is feasible in viewpoint of yield and quality, and that the pectin has potential for substitution of citrus pectin in the food processing industry. / NRF

Rapidly expanding research in nanotechnology has led to exciting progress in a versatile array of applications from medical diagnostics to catalysis. This success resulted from the manipulation of the desired properties of nanomaterials by controlling their size, shape, and composition. Among the most thriving areas of research about nanoparticle is the synthesis and doping of the ligand-protected atomically-precise metal nanoclusters. In this thesis, we developed three different novel metal nanoclusters, such as doped Ag29 with five gold (Au) atoms leading to enhance its quantum yield with remarkable stability. We also developed half-doped (alloyed) cluster of Ni6 nanocluster with molybdenum (Mo). This enabled enhanced stability and better catalytic activity. The third metal nanocluster that we synthesized was Au28 nanocluster by using di-thiolate as the ligand stabilizer instead of mono-thiolate. The new metal clusters obtained have been characterized by spectroscopic, electrochemical and crystallographic methods.

Over one billion people, more than 1/9th of the global population, are undernourished. Feeding the ever increasing population has to be the most important goal of plant sciences. Since cultivated areas are not likely to increase, I will need to produce more with what is available. This can be summarized in one word: yield. Unfortunately, wheat’s yield is expected to increase only 1.13% by 2019, a prediction that if converted into reality will likely indicate that I failed to cope with the world demographic increase. A new strategy to revolutionize wheat production is required, and some believe that this change might be represented by wheat hybrids. Achieving adequate commercial production of wheat hybrids has the potential to nearly double the yield of one of the world’s most important staple food. The first fundamental step toward this goal is to develop feasible methodologies to sterilize the male part of the complete wheat flowers. Two fertility-related genes are the primary target of this study, namely the species cytoplasm specific on chromosome 1D, and the desynaptic locus on chromosome 3B. This dissertation summarizes the important achievements obtained toward the cloning of the two loci by means of radiation hybrid functional analysis. Radiation hybrid is a technique that employs radiation to create genetic diversity along the targeted chromosome. Chapter 1 explains in details how this methodology can be applied to plants. The use of radiation hybrid mapping permitted creating a comprehensive map of wheat chromosome 3B, as discussed in Chapter 2, and then expanded the mapping information to identify the 2 Mb location of the desynaptic locus desw2, as discussed in Chapter 3. A similar approach on chromosome 1D allowed first to pinpoint the location of the species cytoplasm specific gene to a region of 2 Mb, as discussed in Chapter 4, and then ultimately to find a strong candidate for this locus, as discussed in Chapter 5. Now that the molecular locations of these genes have been unraveled by this study, their sequence can be streamlined into transformation to ultimately produce female wheat plants, and consequently hybrids.