The preservative challenge test is a regulatory requirement specified in various pharmacopoeias to determine the efficacy of preservatives. However, such testing is a labour-intensive repetitive task and often requires days before results can be generated. Microbial biosensors have the potential to provide a rapid and automated alternative to the traditional viable counting currently in use. However, the selection of appropriate promoters is essential. The bioluminescent reporter strains used in the current study comprise the Photorhabdus luminescence lux CDABE reporter genes under the control of five individual constitutive Escherichia coli promoters: outer lipoprotein (lpp); twin arginine translocase (tatA); lysine decarboxylase (ldc); lysyl t-RNA (lysS); and ribosomal protein (spc). The promoter plus lux CDABE constructs were cloned, ligated into the plasmid vector pBR322 and transformed into E. coli ATCC 8739. The bioluminescence intensity in the decreasing order of constitutive promoter was lpp > spc> tatA> ldc > lysS. The five biosensor strains tested successfully in PET assays and demonstrated accuracy with a minimum detection limit of 103 CFU/ml, a detection range of 6 orders magnitude, and yielded equivalent results to methods currently recommended by the pharmacopoeias. The bioluminescent biosensors were used to monitor the efficacy of preservatives; sorbic acid at concentrations of 0.031% to 0.2% at pH 5.0, and benzalkonium chloride at concentrations of 0.0062% to 0.00039% alone and in combination with 0.03% EDTA. The 99.9% percentage of bioluminescence reduction of tatA-lux, ldc-lux, lysS-lux, and spc-lux was statistically equivalent to the 3 log10 CFU/ml reduction as required by the Pharmacopeias’. Strong significant correlations between bioluminescence and the methods recommended by the pharmacopoeias were obtained when the biosensor strains were challenged with preservatives, for all except lpp-lux E. coli. The bioluminescence expressed by the lpp-lux biosensor was significantly lower during long-term stationary phase than it was for any of the other biosensors and was also significantly lower than for any of the other biosensors in the presence of preservatives. Since the plasmid copy number and viable counts for lpp-lux did not change under these conditions, it suggests that perhaps lpp-lux was down regulated under stress conditions. There were no statistically significant differences between the results of the bioluminescence assays and the results of the viable count and ATP chemiluminescence assay. Virtual foot printing (using Regulon DB database) demonstrated that two crp binding sites overlapping the -10 regions are located on the negative strand of the lysS promoter sequences and that one crp binding site is located in lpp. The biosensor strains ldc-lux exhibited levels of bioluminescence per cell significantly lower than spc in the presence of preservatives whilst there was a significant increase in bioluminescence per cell by tatA-lux under alkaline conditions (pH 8.9) during long-term stationary phase. Amongst the five biosensor strains tested in the current work, it was determined that the spc-lux strain would be the most attractive candidate for further work, since the bioluminescence expressed per cell was significantly greater, by 10-1000 times, than that expressed by the other four promoters when challenged with the preservatives tested with excellent significant correlations between bioluminescence expression and viable counts in the PET assays with the various preservatives in this study (R2: 8.79-1.00). The bioluminescent biosensor strains showed no statistical differences from the control strains (wildtype E.coli ATCC 8739 and E.coli carrying a promoterless [pBR322.lux] for adneylate energy charge (AEC), plasmid copy number (PCN) bioluminescence or viable counts over 28 days. The emission of bioluminescence by the four bioreporter strains across 28 days is reflected by the stability of PCN with correlations of 0.78-0.90, except for lpp-lux with R2: 0.59. The following promoter elements were found likely to assist greater expression of bioluminescence: an A+T level of approximately 50% between the -40 and -60 regions (the UP element); a G+C level of approximately 50% within the -10 and +1 regions; the extended -10 region and -10 region of consensus sequence RpoD (σ70/D).

Thesis (Ph.D.)--Mississippi State University. Department of Counseling and Educational Psychology. / Title from title screen. Includes bibliographical references.

The purpose of the study was to examine the role of test anxiety, academic self-efficacy, and cognitive appraisal processes in predicting eighth grade students&rsquo / emotion regulation strategies during test taking. In addition, gender was included as a predictor in the study. The sample of the study consisted of 778 eighth grade students (398 females and 380 males) in 17 schools of &Ccedil / ankaya and Yenimahalle districts in Ankara. Emotion Regulation during Test Taking Scale (ERT) (Schutz, Distefano, Benson, &amp / Davis, 2004), Anxiety subscale of Academic Emotions Questionnaire (AEQ) (Pekrun, Goetz, Titz, &amp / Perry, 2002), and Academic Self-Efficacy Scale (ASE) (Jerusalem &amp / Schwarzer, 1981) were used to collect the data. Confirmatory factor analyses (CFA) were performed for the ERT, anxiety subscale of AEQ, and ASE scale. All of the scales were working as intended. Cronbach alpha coefficients were .85 for test anxiety, .76 for ASE, and ranged from .58 to .75 for ERT scale. Four separate hierarchical regression analyses were conducted to examine the role of gender, cognitive appraisal processes (goal congruence, agency, and testing problem efficacy), academic self-efficacy, and test anxiety in predicting four emotion regulation strategies: task focusing, tension reduction, wishful thinking, and self blame strategies. For all strategies, almost all of the predictors were found statistically significant. Test anxiety was found to be the most powerful predictor for all the dependent variables. Girls tend to use more emotional regulation strategies than boys.

Among the main diseases that affect ruminants around the world, infections by gastrointestinal nematodes display an important role. These infections, negatively impact the performance of the animals, compromising the economic viability of the systems, if the correct control of these parasites is not made. In this sense, were performed the evaluation of different compounds with anthelminthic action in sheep and cattle in the state of Rio Grande do Sul. The first chapter presents the study whose objective was to evaluate the anthelminthic resistance of gastrointestinal nematodes from naturally infected cattle with different anti-helminthic therapy commercially available in the state of Rio Grande do Sul; and test the effectiveness of combinations of these principles on multiresistant populations. For both, were selected 70-100 animals, with ages between 7 to 9 months, naturally infected and with egg counts per gram of feces (EPG) ≥200. These individuals were from ten different property located in Rio Grande do Sul, which had received no anthelmintic treatment in the 60 days preceding the beginning of the study. The animals were randomly divided in ten groups (7- 10 animals each) and treated with ivermectin, doramectin, eprinomectin, fenbendazole, closantel, disophenol, nitroxynil, albendazole, levamisole or moxidectin. Additional groups of 7 to 10 calves were used to test six combinations of two drugs each in four of studied properties. In general, the fenbendazole was the most effective drug, followed by levamisole, disofenol and moxidectin. However parasites of genera Cooperia, Trichostrongylus and Haemonchus were the most resistant to different treatments employed. The combinations of moxidectin+levamisole, doramectin+fenbendazole and levamisole+closantel were the most effective. The results of this study demonstrated the existence of multidrug-resistant populations to most of the anthelmintic substances commercially available, while combinations of these may represent an alternative for improvement of the efficacy of treatments. The second chapter had as objective to verify the efficacy of monepantel (Zolvix ®) on gastrointestinal nematodes of naturally infected lambs from two properties in the central region of the state of Rio Grande do Sul, Brazil. For it, 64 animals being, 17 animals treated with Zolvix and 17 control animals not treated in property 1, and 20 animals treated with the same principle and 10 control on the property 2, were used. In both properties, the animals did not receive any anthelmintic treatment in the 30 days prior to the study and had EPG ≥200. The efficacy of monepantel was 25.8% and 78.4%, respectively, in the properties 1 and 2, being Haemonchus spp., Trichostrongylus spp. and Cooperia spp. the genera that presented greater resistance to it. It was demonstrated that the status of anthelminthic resistance in sheep is getting worse once the last drug launched in the Brazilian market for the treatment of gastrointestinal infections of the animals proved ineffective, and further studies are needed to delay the appearance of new cases of resistance to this drug and the other compounds commercially available. / Entre as principais enfermidades que afetam ruminantes ao redor do mundo, as infecções por nematódeos do trato gastrointestinal ocupam papel de destaque. Estas infecções impactam negativamente o desempenho dos animais, comprometendo a viabilidade econômica dos mesmos, uma vez que não se faça o controle adequado destes parasitas. Neste sentido, foi realizada a avaliação de diferentes compostos com ação anti-helmíntica em bovinos e ovinos no estado do Rio Grande do Sul. O primeiro capítulo, apresenta o estudo cujo objetivo foi avaliar a resistência anti-helmíntica de nematódeos gastrointestinais de bovinos naturalmente infectados à diferentes anti-helmínticos comercialmente disponíveis no estado do Rio Grande do Sul; e testar a eficácia de combinações destes princípios sobre populações multirresistentes. Para tanto, foram selecionados 70 a 100 bovinos, com idades entre sete a nove meses, naturalmente infectados e com contagens de ovos por grama de fezes (OPG) ≥200. Estes indivíduos eram oriundos de 10 propriedades diferentes localizadas no Rio Grande do Sul, as quais não haviam realizado tratamento anti-helmíntico nos 60 dias precedentes ao início do estudo. Os animais foram aleatoriamente alocados em dez grupos (7- 10 animais cada) e tratados com ivermectina, doramectina, eprinomectina, fenbendazole, closantel, nitroxinil, disofenol, levamisole, albendazole ou moxidectina. Grupos adicionais de 7 a 10 bezerros foram utilizados para testar seis combinações, de duas drogas cada, em quatro das propriedades estudadas. De maneira geral o fenbendazole foi a droga mais eficaz, seguido pelo levamisole, disofenol e moxidectina. Parasitas dos gêneros Cooperia, Trichostrongylus e Haemonchus foram os mais resistentes aos diferentes tratamentos empregados. As combinações de moxidectina+levamisole, doramectina+fenbendazole e levamisole+closantel foram as mais eficazes. Os resultados deste estudo demonstraram a existência de populações multirresistentes a maioria dos anti-helmínticos comercialmente disponíveis, enquanto combinações destes podem representar uma alternativa para melhora de eficácia dos tratamentos. O segundo capítulo teve por objetivo verificar a eficácia do monepantel (Zolvix ®) sobre nematódeos gastrointestinais de cordeiros naturalmente infectados oriundos de duas propriedades da região central do estado do Rio Grande do Sul, Brasil. Para tanto, 64 animais sendo, 17 animais tratados com zolvix e 17 animais controle não tratados na propriedade 1, e 20 animais tratados com o mesmo princípio e 10 controle na propriedade 2, foram utilizados. Em ambas as propriedades, os animais não receberam tratamento anti-helmíntico nos 30 dias anteriores ao estudo e possuíam OPG ≥200. A eficácia do monepantel foi de 25,8% e 78,4%, respectivamente, nas propriedades 1 e 2, sendo que os gêneros que apresentaram resistência foram Haemonchus, Trichostrongylus e Cooperia. Demonstrou-se que a resistência anti-helmíntica em ovinos vem se agravando dada a ineficácia da última droga lançada no mercado brasileiro em combater a infecção dos animais, sendo necessários mais estudos para retardar o aparecimento de novos casos de resistência a este e aos demais compostos disponíveis comercialmente.