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Pathogenesis, immunity, and prevention of human norovirus infection in gnotobiotic pigsLei, Shaohua 23 April 2018 (has links)
Human noroviruses (HuNoVs) are the leading cause of viral epidemic acute gastroenteritis and responsible for the deaths of over 200,000 children each year worldwide. HuNoV research has been hampered by the long absence of a readily reproducible cell culture system and a suitable small animal model, while gnotobiotic (Gn) pigs have been a unique animal model for understanding HuNoV pathogenesis and immunity, as well as evaluating vaccine and therapeutics. Recent reports of HuNoVs infection and replication in B cells supplemented with commensal bacteria Enterobacter cloacae and in Blab/c mice deficient in RAG/IL2RG have gained extensive attention, and my studies utilized the well-established Gn pig model to investigate the effects of these two interventions on HuNoV infection. Surprisingly, the colonization of E. cloacae inhibited HuNoV infectivity in Gn pigs, evidenced by the significantly reduced HuNoV shedding in feces and HuNoV titers in intestinal tissues and blood compared to control pigs. Moreover, HuNoV infection of enterocytes but not B cells was observed with or without E. cloacae colonization, indicating B cells were not a target cell type for HuNoV in Gn pigs. On the other hand, using RAG2/IL2RG deficient pigs generated by CRISPR/Cas9 system, with confirmed severe combined immunodeficiency, I evaluated the effects of host immune responses on HuNoV infection. Compared to wild-type Gn pigs, longer HuNoV shedding was observed in RAG2/IL2RG deficient pigs (16 versus 27 days), and higher HuNoV titers were detected in intestinal tissues and contents and in blood, indicating increased and prolonged HuNoV infection in RAG2/IL2RG deficient pigs. In addition, I evaluated dietary interventions including probiotics and rice bran using Gn pig model of HuNoV infection and diarrhea. While the colonization of probiotic bacteria Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle 1917 (EcN) in Gn pigs completely inhibited HuNoV fecal shedding, the two cocktail regimens, in which rice bran feeding started either 7 days prior to or 1 day after viral inoculation in the LGG+EcN colonized Gn pigs, exhibited dramatic anti-HuNoV effects, including reduced incidence and shorter duration of diarrhea, as well as shorter duration of virus fecal shedding. The anti-HuNoV effects of the cocktail regimens were associated with the enhanced IFN-𝛾⁺ T cell responses, increased production of intestinal IgA and IgG, and longer villus length. Taken together, my dissertation work improves our understanding of HuNoV infection and immunity, and further supports for Gn pigs as a valuable model for future studies of human enteric virus infection, host immunity, and interventions. / Ph. D. / Human noroviruses (HuNoVs) are the leading cause of viral epidemic acute gastroenteritis. Using the gnotobiotic pig model of HuNoV infection and diarrhea, we found that (1) the colonization of a commensal bacterium E. cloacae inhibited HuNoV infectivity, and B cells were not a target cell type for HuNoV in gnotobiotic pigs. (2) Increased and prolonged HuNoV infection in RAG2/IL2RG deficient pigs, which had severe combined immunodeficiency. (3) The dietary supplementation of rice bran and colonization of two probiotic bacteria significantly reduced HuNoV infectivity and diarrhea, and the beneficial effects were associated with enhanced intestinal immunity and health. Taken together, the dissertation work improves our understanding of HuNoV infection and immunity, and further supports for gnotobiotic pigs as a valuable model for future studies of human enteric virus infection, host immunity, and interventions.
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Studies of pathogenesis, innate immunity and therapeutics of human enteric viruses in gnotobiotic pigsCastellucci, Tam Bui 26 May 2017 (has links)
Norovirus and rotavirus are the most common viral causes of acute gastroenteritis among all age groups and in children under 5 years of age, respectively. Understanding the pathogenesis of the virus and correlates of protective immunity is fundamental to developing effective prevention and treatment strategies. Gnotobiotic (Gn) pigs are an attractive animal model for studying enteric viruses due to their similarities to humans, particularly in regards to the immune system and gastrointestinal anatomy and physiology. Here, to establish a reliable Gn pig model of human norovirus (HuNoV) infection and disease, we determined the median infectious dose (ID50) of a GII.4 2006b variant in pigs. We also evaluated the effects of age and administration of the cholesterol-lowering drug simvastatin on susceptibility to NoV infection. In neonatal pigs (4-5 days of age, the ID50 was determined to be 2.74 x 103 viral RNA copies. The ID50 was increased in 33-34 day old pigs (6.43 x 104), but decreased to <2.74 x 103 following simvastatin treatment in the same age group. Overall, the development of diarrhea, fecal virus shedding and small intestinal cytopathological changes confirmed the usefulness of the Gn pig as an appropriate animal model for studying HuNoVs. We also utilized the well-established Gn pig model of human rotavirus (HRV) infection and disease to evaluate adjunctive treatment options for HRV-induced diarrhea. We demonstrated that the anti-secretory drug racecadotril was capable of diminishing clinical signs of HRV infection and shortening duration of illness. Reduced dehydration in the racecadotril-treated pigs was evident by the significant gain in body weight compared to controls during the course of the study. We also determined that a high dose of the probiotic Lactobacillus acidophilus NCFM (LA) was able to reduce RV diarrhea severity and duration compared to a low dose. The difference in therapeutic potential was attributed to divergent effects in innate immunity pre- and post-challenge. High dose of LA (HiLA) induced an anti-inflammatory dendritic cell (DC) profile, characterized primarily by upregulation of TLR2 expression and production of cytokine IL-10. Conversely, low dose of LA (LoLA) upregulated TLR3 and TLR9 and increased secretion of cytokine IL-6. Additionally, HiLA induced both IFN-alpha and TNF-alpha responses in DCs, but LoLA was only able to increase the frequency of TNF-alpha-producing DCs. These results provide further support of Gn pigs as a highly applicable animal model for studying pathogenesis, innate immunity and therapeutics of human enteric viruses. / Ph. D. / Norovirus and rotavirus are the most common viral causes of acute gastroenteritis among all age groups and in children under 5 years of age, respectively. Understanding the pathogenesis of the virus and correlates of protective immunity is fundamental to developing effective prevention and treatment strategies. Gnotobiotic (Gn) pigs are an attractive animal model for studying enteric viruses due to their similarities to humans, particularly in regards to the immune system and gastrointestinal anatomy and physiology. Here, we established a reliable Gn pig model of human norovirus (HuNoV) infection and disease. Overall, the development of diarrhea, fecal virus shedding and small intestinal cytopathological changes confirmed the usefulness of the Gn pig as an appropriate animal model for studying HuNoVs. We also utilized the well-established Gn pig model of human rotavirus (HRV) infection and disease to evaluate adjunctive treatment options for HRV-induced diarrhea. We demonstrated that the anti-secretory drug racecadotril was capable of diminishing clinical signs of HRV infection and shortening duration of illness. We also determined that a high dose of the probiotic <i>Lactobacillus acidophilus</i> NCFM (LA) was able to reduce RV diarrhea severity and duration compared to a low dose. These results provide further support of Gn pigs as a highly applicable animal model for studying pathogenesis, innate immunity and therapeutics of human enteric viruses.
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Investigation of Novel Prophylactics Against Human Rotavirus Using Gnotobiotic Pig ModelsHensley, Casey 22 June 2023 (has links)
Human rotavirus (HRV) is a major causative agent of acute gastroenteritis (AGE), which causes severe dehydrating diarrhea in children under the age of five and results in up to 215,000 deaths worldwide each year. There are two live oral attenuated vaccines licensed for use in the United States that are highly effective in high-income countries but much less so in low-and middle-income countries (LMICs). Several factors contributing to decreased efficacy in these areas include chronic malnutrition, gut dysbiosis, and concurrent viral infection. Along with this, currently used vaccines require constant cold-chain storage to maintain vaccine stability, and those resources can be scarce in LMICs. These areas continue to maintain a high burden of HRV morbidity and mortality, and more efficacious vaccines are needed. The gnotobiotic (Gn) pig model of HRV infection and diarrhea has long been used in the evaluation of novel HRV vaccines due to Gn pigs' susceptibility to HRV infection, development of clinical signs, histopathological changes in the intestine, and the infection kinetics that mimic those seen in human infants. The first project in this dissertation used the Gn pig model to evaluate a thermostable live oral attenuated vaccine administered as a dissolvable film. Two doses of the tetravalent dissolvable film vaccine conferred significant protection from virus shedding by delaying its onset and reducing peak titers in feces. It also significantly delayed the onset of diarrhea and reduced the duration and area under the curve (AUC) of diarrhea. The dissolvable film was highly immunogenic, inducing high titers of serum virus neutralizing (VN) antibodies specific to each of the four G-types included in the vaccine formulation, HRV-specific serum IgA and IgG, and intestinal IgA. These data confirm the thermostable platform as a useful alternative to liquid vaccines that require cold-chain. The second project evaluated three mRNA-based nonreplicating vaccine candidates in the Gn pig model. All three mRNA candidates encoded a universal CD4+ T cell epitope, P2, derived from tetanus toxoid, fused with the encoded VP8* from P[4], P[6], and P[8] HRVs. Two candidates also encoded for a lumazine synthase (LS) domain fused with the P2-VP8*. A dose response study of the LS-P2-VP8* candidates was conducted simultaneously. Significant protection against virus shedding was induced by all three candidates, with LS-P2-VP8* candidates inducing significantly higher VP8*-specific serum IgG. All three candidates induced significantly higher numbers of P[8]-VP8*-specific IgG antibody-secreting cells (ASCs) and IFN-γ-producing T cells in the ileum, spleen and blood. These data provide guidance for further development of the relatively new mRNA-based technology for use in HRV vaccine development. In the final study of this dissertation, we used the Gn pig model of both P[8] and P[6] HRV infection to evaluate a cocktail nanoparticle-based HRV vaccine. This vaccine was made up of an S60 nanoparticle, self-assembled from the S domain of the human norovirus capsid protein. The exposed C-termini on the S60 nanoparticle were utilized as an antigen display platform, where VP8* from P[4], P[6] and P[8] HRVs was fused. This vaccine was tested as both a two-dose intramuscular (IM) regimen, or as an IM booster preceded by an oral priming immunization with commercial monovalent Rotarix®. Pigs were challenged with either P[6] or P[8] HRV to evaluate cross-protection of the nanoparticle vaccine. Both regimens were highly immunogenic, inducing high titers of serum VN, IgG and IgA antibodies. Furthermore, the prime-boost regimen conferred significant protection against virus shedding in P[8] HRV-challenged pigs as evidenced by the shortened duration of fecal virus shedding. There was also significant protection in P[6] HRV-challenged pigs vaccinated with the prime-boost regimen, as evidenced by the shortened duration, reduced mean peak titer and AUC of virus shedding. Prime-boost-vaccinated pigs challenged with P[8] HRV had significantly higher P[8]-specific IgG ASCs in the spleen post-challenge. Prime-boost-vaccinated pigs challenged with P[6] HRV had significantly higher numbers of P[6] and P[8]-specific IgG ASCs in the ileum, as well as significantly higher numbers of P[8]-specific IgA ASCs in the spleen post-challenge. Oral priming followed by parenteral boosting appears to be a promising vaccination strategy for HRV and these data warrant further investigation into this regimen. Through these studies, we improved our understanding of the effect of different vaccination routes and formulations in the effectiveness of conferring protection against an enteric virus. The knowledge will facilitate the development of more effective vaccination strategies against HRV, the leading cause of infantile diarrhea in LMICs, as well as other enteric viruses. / Doctor of Philosophy / Human rotavirus (HRV) is a major causative agent of acute gastroenteritis (AGE) in children under the age of five. Acute gastroenteritis is characterized by nausea, vomiting, and potentially deadly dehydrating diarrhea. There are two highly effective vaccines licensed for use in the United States; however, these vaccines are much less effective in low- and middle-income countries (LMICs), where HRV disease burden is the highest. There are several reasons thought to be responsible for the decrease in effectiveness seen in these areas, including chronic malnutrition and gut dysbiosis. Non-biological reasons for decreased efficacy may include the breakdown of cold-chain storage for these vaccines, which require constant low temperature storage that is often unavailable in LMICs. Thermostable vaccines are necessary for increasing vaccine distribution and efficacy in these areas. Because many of the biologic factors thought to interfere with the effectiveness of these vaccines appear to be confined to the gastrointestinal tract, development of next generation HRV vaccines has focused on the parenteral route of administration. The gnotobiotic (Gn) pig model is a highly relevant animal model that has been used for decades to evaluate novel HRV vaccine efficacy. Our first study evaluated a thermostable, dissolvable live oral vaccine administered as a dissolvable film in our Gn pig model. Two doses of this vaccine significantly reduced the severity of diarrhea and virus shedding in the stool. Our second study evaluated three mRNA-based intramuscular (IM) vaccines in the Gn pig model. Three doses of all mRNA candidates provided significant protection from virus shedding in the stool, as well as inducing the production of strong HRV-specific antibodies in the serum and high numbers of virus-specific T cells in the tissues. In our final study, we evaluated a nanoparticle-based vaccine as a two-dose IM regimen or as an IM booster preceded by an oral immunization using the commercially available Rotarix® vaccine. The prime-boost regimen significantly shortened the duration and severity of virus shedding in the stool. We also detected more cross-strain HRV-specific antibody-secreting cells in the tissues. All three vaccines evaluated in this dissertation offer differing novelty in the field of HRV vaccine development, and the Gn pig model has been instrumental in the evaluation of these vaccines.
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Decision Making During National Security Crisis: The Case of the JFK AdministrationBeckner, Lauren Renee 15 October 2012 (has links)
Decision-making during crises is an important task that many elected officials face during their time in office. This thesis seeks to identify principles that make up a sound policy decision-making process and may lead to more positive outcomes. The analysis here is a comparative case study of three national security crises that faced the John F. Kennedy administration: the Bay of Pigs, the Cuban Missile Crisis, and the Vietnam conflict. Each case is examined for the presence of indicators of groupthink. I hypothesize that the relative absence of groupthink is related to a positive outcome. That hypothesis is examined by reviewing each case; the cases that contained higher levels of the indicators of groupthink tended to have a poorer quality process than those with less evidence of groupthink. / Master of Arts
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Effects of Naloxone on Kidney Weight, Macromolecular Constituents of Kidney and Cortisol Secretion in Fetal and Neonatal Pigs / Auswirkungen von Naloxon auf Nierengewicht, makromolekulare Bestandteile der Niere und Cortisolsekretion bei fötalen und neugeborenen SchweinenLi, Dingjian 19 July 2007 (has links)
No description available.
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Genetic Heteroscedasticity for Domestic Animal TraitsFelleki, Majbritt January 2014 (has links)
Animal traits differ not only in mean, but also in variation around the mean. For instance, one sire’s daughter group may be very homogeneous, while another sire’s daughters are much more heterogeneous in performance. The difference in residual variance can partially be explained by genetic differences. Models for such genetic heterogeneity of environmental variance include genetic effects for the mean and residual variance, and a correlation between the genetic effects for the mean and residual variance to measure how the residual variance might vary with the mean. The aim of this thesis was to develop a method based on double hierarchical generalized linear models for estimating genetic heteroscedasticity, and to apply it on four traits in two domestic animal species; teat count and litter size in pigs, and milk production and somatic cell count in dairy cows. The method developed is fast and has been implemented in software that is widely used in animal breeding, which makes it convenient to use. It is based on an approximation of double hierarchical generalized linear models by normal distributions. When having repeated observations on individuals or genetic groups, the estimates were found to be unbiased. For the traits studied, the estimated heritability values for the mean and the residual variance, and the genetic coefficients of variation, were found in the usual ranges reported. The genetic correlation between mean and residual variance was estimated for the pig traits only, and was found to be favorable for litter size, but unfavorable for teat count.
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Disruptive game design : a commercial design and development methodology for supporting player cognitive engagement in digital gamesHowell, Peter Mark January 2015 (has links)
First-person games often support the player’s gradual accretion of knowledge of the game’s rules during gameplay. They thus focus on challenging and developing performative skills, which in turn supports the player in attaining feelings of achievement and skills mastery. However, an alternative disruptive game design approach is proposed as an approach that encourages players to engage in higher-order thinking, in addition to performative challenges. This requires players to cognitively engage with the game at a deeper level. This stems from the player’s expectations of game rules and behaviours being disrupted, rather than supported, requiring players to learn and re-learn the game rules as they play. This disruptive approach to design aims to support players in satiating their needs for not only achievement and mastery at a performative level but also, their needs for problem-solving and creativity. Utilising a Research through Design methodology, a model of game space proposes different stages of a game’s creation, from conceptualisation through to the final player experience. The Ludic Action Model (LAM), developed from existing game studies and cognitive psychological theory, affords an understanding of how the player forms expectations in the game as played. A conceptual framework of game components is then constructed and mapped to the Ludic Action Model, providing a basis for understanding how different components of a game interact with and influence the player’s cognitive and motor processes. The Ludic Action Model and the conceptual framework of game components are used to construct the Disruptive Game Feature Design and Development (DisDev) model, created as a design tool for ‘disruptive’ games. The disruptive game design approach is then applied to the design, development, and publication of a commercial game, Amnesia: A Machine for Pigs (The Chinese Room, 2013). This application demonstrated the suitability of the design approach, and the proposed models, for establishing disruptive game features in the game as designed, developing those features in the game as created, to the final resolution in the game as published, which the player will then experience in the game as played. A phenomenological template analysis of online player discussions of the game shows that players tend to evaluate their personal game as played (i.e. their personal play experience) in relation to their a priori game as expected (i.e. the experience that they expected the game to provide). Players reported their play experiences in ways that suggested they had experienced cognitive engagement and higher-order thinking. However, player attitudes towards this type of play experience were highly polarised and seemingly dependent on the correspondence between actual and expected play experiences. The discussion also showed that different methods of disruption have a variable effect on the player experience depending on the primacy of the game feature being disrupted. Primary features are more effectively disrupted when the game’s responses to established player actions are subsequently altered. Secondary game features, only present in some sections, are most effectively disrupted when their initially contextualised behaviour is subsequently altered, or recontextualised. In addition, story-based feature disruption is most effected when the initial encoding stage is ambiguous, thus disrupting players’ attempts to form an initial understanding of them. However, these different methods of disruption may be most effective when used in conjunction with each other.
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Pig tail biting in different farrowing and rearing systems with a focus on tail lesions, tail losses and activity monitoringGentz, Maria 09 July 2020 (has links)
No description available.
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Människan som skapare, eller Den moderne Gud : Skapelseberättelsen som den skildras i Clay och Amnesia: A Machine for Pigs genom Milton och Shelley / Man as creator, or The modern God : The creation myth as it is portrayed in Clay and Amnesia: A Machine for Pigs through Milton and ShelleyNordmark, Ida January 2018 (has links)
This thesis concerns the themes of godhood and creation in modern, secular works. Using literary analysis, the thesis examines how the creation myth and the relationship between creator and creation is written in David Almond’s novel Clay and the video game Amnesia: A Machine for Pigs, in comparison with how the same relationship is presented in Frankenstein and Paradise Lost. The thesis focuses on how the different works portray the themes of god, creation, original sin, and atonement, where the portrayals differ and where are the same. It ends with a discussion on how modern, secular stories using these themes manage to separate themselves from their religious origins while still remaining true to their inspirations. / Denna uppsats behandlar ämnena gudomlighet och skapelse i moderna, sekulära verk. Genom att använda litterär analys undersöker uppsatsen hur skapelseberättelsen och förhållandet mellan skapare och skapelse skildras i David Almonds roman Clay och datorspelet Amnesia: A Machine for Pigs i jämförelse med hur samma förhållande presenteras i Frankenstein och Paradise Lost. Uppsatsen fokuserar på hur de olika verken skildrar temana gud, skapelsen, syndafallet och försoningen, samt skillnader och likheter i skildringarna. Den avslutas med en diskussion om hur moderna, sekulära berättelsen som använder dessa teman separerar sig från sitt religiösa ursprung men ändå förblir trogna sina inspirationer.
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Utilization of distiller’s dried grains with solubles in swine dietsWilliams, Scott Matthew January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / Joe D. Hancock / Six experiments were completed to determine factors influencing the use of distillers dried grains with solubles (DDGS) in diets for nursery and finishing pigs. In Exp. 1, 105 nursery pigs were fed corn-soybean meal (SBM) based diets with CP concentrations of 22.5, 25, and 27.5%. Overall ADG, ADFI, and G:F were not affected by increasing CP (P > 0.19). In Exp. 2, 105 nursery pigs were fed excess CP from SBM and DDGS. Overall ADG, ADFI, and G:F for pigs fed the control diet were not different from those fed the high CP treatments (P > 0.12). However, pigs fed the DDGS treatment had lower G:F than pigs fed the corn-soy diet with similar CP content (P < 0.04). For Exp. 3, 176 finishing pigs were fed diets with CP concentrations increasing from 12 to 18%. Increasing CP had no effect (P > 0.20) on ADG, ADFI, G:F, and hot carcass weight (HCW). For Exp. 4, 180 finishing pigs were fed excess dietary CP from SBM and DDGS. Pigs fed diets with high CP had lower ADG, ADFI, and HCW, but these results were caused by the diet with 40% DDGS (SBM vs DDGS, P < 0.001). For Exp. 5, 224 nursery pigs were used to determine the effects of extrusion processing on the nutritional value of DDGS. Overall ADG and ADFI were greater for pigs fed the corn-soy control compared to the DDGS treatments (P < 0.02). Extruding the DDGS did not improve ADG or G:F (P > 0.11), but DM and GE digestibility were greater for diets with extruded DDGS vs. unprocessed DDGS (P < 0.04). In Exp. 6, 200 finishing pigs were fed DDGS-based diets formulated for ME, NE, and digestible amino acids. Feeding DDGS lowered ADG (P < 0.09) and ADFI (P < 0.05). Formulating for ME, NE, and digestible amino acids needs improved ADG and G:F (P < 0.002) to that of the corn-soy control diet. In conclusion, moderate excesses of dietary CP does not impact growth performance. Also, extruding DDGS can improve the
nutritional value of diets for nursery pig and formulating for ME, NE and digestible amino acid needs can improve growth performance of finishing pigs fed diets with high levels of DDGS.
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