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This study was conducted to: (a) determine the optimum extender system for two extenders that will maintain the highest level of cellular integrity when stored at either 5C or 15C for a minimum of 72 hr; (b) evaluate the fertilizing capacity of stored spermatozoa using the optimum extender system; (c) critically analyze enzymatic and morphological changes associated with storage and aging of boar spermatozoa; and (d) characterize properties of boar spermatozoa important to fertilization. The least-squares means for the percentage of normal apical ridge acrosomes were significantly affected by ejaculate within boar (P< .001), boar x extender (P< .05), boar x storage temperature (P< .01), extender x storage temperature (P<.01), extender x cooling rate (P< .05) and antibiotic x storage temperature (P< .01). The regression equations of storage time x treatment effect were reported. The least-squares means for acrosin activity were significantly affected by ejaculate within boar (P<.001), ejaculate within boar x antibiotic (P< .05), ejaculate within boar x extender (P<. 001), ejaculate within boar x storage temperature and extender x storage temperature (P< .05). The regression of storage time x storage temperature was reported. The least-squares means for progressive forward motility were significantly affected by extender (P< .05), antibiotic (P< .05), ejaculate within boar (P< .001), antibiotic x extender (P< .05) and extender x storage temperature (P< .01). The regressions of storage time x treatment effects were reported. The least-squares means for vibrational and/or rotational motility were affected by ejaculate within boar (P< .001), ejaculate within boar x extender (P<.001), ejaculate within boar x cooling rate (P<.05), antibiotic x extender and extender x storage temperature (P< .01). The optimum extender system consisted of Purdue extender containing penicillin/streptomycin and cooled to a 15C storage temperature in 4 hours. This extender system maintained a 70% minimum fertilization rate for 84 hours. / Ph. D.

A comparison of the results of Experiments 1 and 2 vividly demonstrates the vulnerability of ram spermatozoa to the stress of freeze-thawing. When ram spermatozoa were subjected to freeze-thaw stress, there was more variation among treatments reflected in maintenance of both intact acrosomes and motile life (Experiment 2, Table 9) than when unfrozen sperm were studied (Experiment 1, Table 5). The influence of glycerol and Tris are particularly noteworthy. Though rate of thaw is not part of the surrounding media, it does control the amount of time the cells are subjected to an even more hostile environment (high salt concentrations) encountered near the melting point of ice. Therefore, the benefit of higher thaw temperatures and resulting faster thaw rates was undoubtedly due to minimizing exposure time of spermatozoa to this adverse condition. / Master of Science

The purpose of this study was to investigate the effects of freezing on apple slices in a sucrose media with two levels of replacement of regular and high conversion and commercial corn syrups. The dextrose equivalent of the syrup, drained weight, soluble solids of the syrup and fruit, the relationship of cellular structure and firmness and acceptability as judged by a taste panel were studied after 3 weeks and 3 months storage. Objective measures included drained weight, soluble solids, reducing sugar content of the syrup, Alla-Kramer shear press readings of firmness and microscopic examination of the apple tissue. Color, flavor, sweetness, firmness and overall acceptability of the apple slices were measured subjectively by a taste panel. The results obtained indicated that there was a movement of water out of the apple tissue, the amount of which was dependent on the dextrose equivalent of the syrup. There was also some slight migration of sugars into the apple slices, after cellular damage occurred. As the dextrose equivalent of the freezing media increased there was a decrease in drained weight and syrup soluble solids and an increase in fruit soluble solids, browning, cellular damage and firmness. The addition of" 25% commercial corn syrup to a 40% sucrose syrup would be highly recommended as a freezing media for York Imperial apples because of the increase in drained weight. slight increase in fruit soluble solids, less cellular damage and the retention of a more natural color. / Master of Science

In the experimental work conducted, two cases have been considered for the six- finned internal star cylinder: the semi-elliptic natural crack and a machined V-cut crack extending the length of the cylinder, both originating from the axis of symmetry of the fin tip. The V-cut crack constitutes a plane strain approximation and is used in current design rationale. Results show that the normalized stress intensity factor (SIF) for the V-cut case are at least equal to, but in most cases are greater than, the natural crack cases. These results were compared to experimental results from Smith and his associates for motor grains having similar shaped off-axis cracks, and similar trends were achieved. Comparisons were also made between the natural crack models and the modified boundary element method of Guozhong, Kangda, and Dongdi (GKD) for a semi-elliptic crack in a circular cylinder and the V-cut crack models to the modified mapping collocation technique of Bowie and Freese (BF), which constitutes the plane strain solution to a circular cylinder with a crack extending the length of the bore. For both cases general trends were similar. Using the numerical results, a relation for estimating the plane strain SIF for the finned cylinder models was developed. The situation of a finned cylinder containing a crack the length of the bore constitutes the worst case scenario. Testing has shown, however, that under normal loading conditions this case is conservative. Penetration tests have shown that a crack penetrating the outer boundary retains its semi-elliptic shape, thus the use of a semi-elliptic crack in design more accurately represents reality. / Master of Science

Two successive ejaculates were collected from six mature Holstein bulls at 3 d intervals for 7 wks. Elevated testicular temperature was induced by complete coverage of the scrotum with insulated material for 48 h. Viability (motility and acrosome integrity) and morphological characteristics of sperm before and after thermal insult were examined. For assessment of results, collection days were grouped: days -6, -3, 0 = Period 1 (d 0 = day of testis coverage after semen collection on that day), days 3, 6, 9 = Period 2 , days 12, 15...39 = Period 3. Semen was cryopreserved on each day of collection until morphological abnormalities of sperm increased to >50%. Semen viability before and after freezing was lower in Period 3 than in Period 1 (P≤.01). These differences coincided with increased abnormal morphology. No differences in viability were observed between Period 1 and Period 2 for unfrozen semen. Once frozen, spermatozoa ejaculated during Period 2 were significantly different from Period 1 for both viability measurements, but only after 3 h incubation at 37°C (P≤.01). Mean percent pre-insult abnormal sperm level was 19.6 ± 5.7 and sperm morphology in Period 1 (pre-insult) did not differ from that in Period 2. Morphological change was first noted in Period 3 on d 12 and 15 (47.5 ± 27.4 and 65.0 ± 27.0 % abnormal sperm, respectively). Abnormal sperm peaked on d 21 (83.2 ± 22.8 %). Although bulls varied in degree and time of response post-insult, all bulls exhibited the same sequence of appearance for specific abnormalities. The sequence and peak means for these abnormalities observed over all bulls were as follows: decapitated sperm, d 15 (33.9 ± 28.8 %); diadem defect, d 18 (55.6 ± 25.8 %); pyriform heads and nuclear vacuoles (excluding diadems), d 21 (18.3 ± 17.6 and 20.8 ± 10.5 %, respectively); knobbed acrosomes, d 27 (11.6 ± 13.6 % ). Sperm morphology was followed through d 39, by which time all bulls were producing ≤50% abnormal cells (35.2 ± 8.0 %). We concluded that viability of epididymal/rete sperm was adversely affected by elevated testicular temperatures, as noted by lowered viability of cryopreserved semen, and that there is a sequence in appearance of abnormal cell types in repsponse to thermal insult of the testis. / Master of Science

Master of Science / Food Science Institute -- Animal Science & Industry / Daniel Y.C. Fung / In February 2008, the FDA released a draft Compliance Policy Guide (CPG) on Listeria monocytogenes and proposed that ready-to-eat (RTE) foods that do not support the growth of L. monocytogenes may contain up to 100 CFU/g of this pathogen. Frozen foods such as ice cream fall in that category since they are consumed in the frozen state. However, other frozen foods, such as vegetables and seafood that are thawed and served at salad and food bars, may support the growth of Listeria and would not be allowed to contain 100 CFU/g according to the draft CPG. In the current study, growth curves were generated for L. monocytogenes inoculated onto four thawed frozen foods - corn, green peas, crabmeat, and shrimp - stored at 4, 8, 12, and 20ºC. Growth parameters, lag phase duration (LPD), and exponential growth rate (EGR) were determined using a two-phase linear growth model and the Square Root Model. The results demonstrated that L. monocytogenes has a very short LPD on these thawed frozen foods during refrigerated storage and that there would be several orders of magnitude of growth (i.e., more than 1.7 log increase at 4 ºC) of the organism before the product is found to be organoleptically unacceptable. Although it would not be possible to take advantage of any extended lag phase duration caused by freeze injury to the organism, frozen foods containing less than 100 CFU/g of L. monocytogenes that are thawed, or thawed and cooked, and then consumed immediately, should not represent a public health hazard.

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2018-12-20T12:44:41Z No. of bitstreams: 1 Evelin de Oliveira Haslinger_.pdf: 5046631 bytes, checksum: 8e3756ab9ff98b285790f47a98bc7469 (MD5) / Made available in DSpace on 2018-12-20T12:44:41Z (GMT). No. of bitstreams: 1 Evelin de Oliveira Haslinger_.pdf: 5046631 bytes, checksum: 8e3756ab9ff98b285790f47a98bc7469 (MD5) Previous issue date: 2018-09-10 / CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico / Esta pesquisa é um estudo sobre as transformações dos contos de fadas na sociedade em vias de midiatização. Nosso objetivo central é investigar estas transformações a partir do processo de circulação dos contos de fadas, tomando como referência seu percurso histórico. Trata-se da circulação dos contos de fadas, suas atualizações e permanências inscritas em circuitos, isto é, no fluxo adiante (BRAGA, 2012) por meio de multidispositivos que reiteram a valorização e agenciam novas formas de contato, modificando o próprio público e seu papel. Para tal, selecionamos um conto de fadas para a constituição do nosso caso de pesquisa, sendo ele: a animação “Frozen: uma aventura congelante” (Disney, 2013). Esta obra se destaca como um dos contos de fadas mais populares na atualidade e está entre os que mais geram produtos midiáticos e não midiáticos. O problema de pesquisa que guia nosso estudo é: Como os sentidos sobre Frozen são construídos a partir da tensão entre gramáticas de produção e reconhecimento? Tendo este problema como eixo, voltamo-nos para a análise da animação Frozen a partir de três instâncias: do livro para a animação; da animação e sua circulação e, por fim, a inscrição do conto em uma lógica de consumo. Como aportes teóricos, mobilizamos em especial os conceitos de sociedade dos meios, midiatização e circulação, com atenção aos autores latino-americanos. O trabalho dá pistas não apenas de transformações de meio (do livro para o digital), mas do próprio sentido do conto, cada vez mais cogerido pelos atores sociais. / This research is a study about the transformations of fairy tales in the society in process of mediatization. Our central objective is to investigate these changes from the movement of fairy tales, referring to their historical course. It means the flow of fairy tales, their updates and stays inscribed in circuits, namely in the flow forward (BRAGA, 2012) through multi-devices that reiterate the valorization and organize new forms of contact, modifying the public itself and its role. To that end, we selected a fairy tale for the formation of our survey, being: the animation "Frozen: a freezing adventure" (Disney, 2013). This piece of work stands out as one of the most popular fairy tales nowadays and is among the ones that generate the most media and non-media products. The research problem guiding our study is: How the meanings about Frozen built from the tension among grammars of production and recognition? Highlithing this problem, we return to the analysis of Frozen animation based on three instances: from book to animation; on animation and its circulation and, finally, the inscription of the fairy tale in a logic of consumption. As theoretical contributions we mobilize in particular the concepts of media society, mediatization and circulation with attention to Latin American authors. The work gives clues not only of changes in the media (from the printed to the digital book), but also in the very meaning of the story, which is increasingly co-managed by the social actors.

Author also know as S M Loveday / Fresh bakery products have a very short shelf life, which limits the extent to which manufacturing can be centralised. Frozen doughs are relatively stable and can be manufactured in large volumes, distributed and baked on-demand at the point of sale or consumption. With appropriate formulation and processing a shelf life of several months can be achieved.Shelf life is limited by a decline in proofing rate after thawing, which is attributed to a) the dough losing its ability to retain gas and b) insufficient gas production, i.e. yeast activity. The loss of shelf life is accelerated by delays between mixing and freezing, which allow yeast cells the chance to ferment carbohydrates.This work examined the reasons for insufficient gas production after thawing frozen dough and the effect of pre-freezing fermentation on shelf life. Literature data on yeast metabolite dynamics in fermenting dough were incomplete. In particular there were few data on the accumulation of ethanol, a major fermentation end product which can be injurious to yeast.Doughs were prepared in a domestic breadmaker using compressed yeast from a local manufacturer and analysed for glucose, fructose, sucrose, maltose and ethanol. Gas production after thawing declined within 48 hours of frozen storage. This was accelerated by 30 or 90 minutes of fermentation at 30;C prior to freezing.Sucrose was rapidly hydrolysed and yeast consumed glucose in preference to fructose. Maltose was not consumed while other sugars remained. Ethanol, accumulated from consumption of glucose and fructose, was produced in approximately equal amounts to CO2, indicating that yeast cells metabolised reductively.Glucose uptake in fermenting dough followed simple hyperbolic kinetics and fructose uptake was competitively inhibited by glucose. Mathematical modelling indicated that diffusion of sugars and ethanol in dough occurred quickly enough to eliminate solute gradients brought about by yeast metabolism.

M. Tech. Food Technology / The injection of frozen chicken meat with high levels (m/m) of various brine solutions has been noticed in the South African market. These products are sold with a typical shelf life of one year and the brine solutions used in the commercial factories are being recirculated during normal production. This research project determined the levels (m/m) of brine solutions that contribute to value adding (improved texture and sensory properties) opposed to the levels (m/m) that could result in adulteration (unjustified weight gain/economic adulteration) of frozen chicken meat. The oxidative stability during the one year shelf life as well as the microbiological quality of brine injected frozen chicken meat was also investigated.