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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.
101

Efeito de um fito composto no desempenho de leitões submetidos ao desafio experimental com Salmonella typhimurium / Effect of a phyto compound on the performance of piglets challeged with Salmonella typhimurium

Daniel Gonçalves Bruno 11 July 2008 (has links)
Apesar da eficácia dos antimicrobianos como melhoradores no desempenho animal, questões relativas à seleção de microorganismos resistentes e transferência desses para o consumo humano de carne vêem trazendo uma crescente preocupação que tem provocado diminuição do seu uso. Assim, há necessidade da busca de alternativas, destacando-se as ervas medicinais, as quais apresentam ações, antimicrobiana, antioxidante, imunomodulatória e ainda, estimulante da secreção de enzimas digestivas. O objetivo do estudo foi avaliar a ação de um fito composto, produzido pela adição de partes aéreas secas e trituradas de plantas medicinais (Rosmarinus officinalis, Mentha piperita, Lippia sidoides e Lychnophora pinaster), em leitões, desde a creche até o abate, sobre parâmetros de desempenho, freqüência de diarréia, eliminação fecal de salmonelas, lesões histopatológicas intestinais e oxidação lipídica da carcaça. Os animais foram submetidos a duas situações: uma de desafio experimental (D, com inoculação de Salmonella typhimurium aos 35 dias de idade) e outra sem desafio (SD), permanecendo ambos grupos em salas isoladas. O delineamento experimental foi inteiramente casualizado, com arranjo fatorial 3x2, sendo um fator o desafio, e outro, a suplementação de aditivos na ração (fito composto FITO; antibióticos ATB; e controle negativo, sem adição de promotores CTRL). Foram alojados 120 leitões recém-desmamados aos 21 dias de idade, na unidade de creche do Laboratório de Pesquisa em Suínos. Os animais foram pesados aos 21, 35, 49, 63 dias (creche) aos 96 e 106 dias (crescimento) e 131 dias de idade (terminação), e verificado o consumo de ração. Foi avaliada a freqüência de dias com diarréia (FDD) na creche, além da eliminação fecal de S. typhimurium, observando-se lesões histopatológicas causadas pela bactéria no trato entérico, e oxidação lipídica da carcaça aos 131 dias de idade. Não houve interação entre aditivos e desafio para nenhuma variável estudada. O peso médio (PM) do grupo ATB foi mais elevado durante todos os períodos em relação a FITO e CTRL, e estes não diferiram entre si; no entanto, aos 96 e 106 dias, o PM dos animais CTRL foi maior que FITO. De 21 a 35 dias de idade, a conversão alimentar (CA) do grupo ATB foi significativamente menor que CTRL; no entanto, FITO promoveu valor intermediário, não diferindo estatisticamente de ambos. O desafio experimental levou à queda no consumo diário de ração (CDR) de 35 a 48 dias. No entanto, no período final de crescimento, houve um efeito compensatório sobre as variáveis de desempenho, sendo PM, ganho diário de peso (GDP), CDR e CA significativamente melhores na sala D. Ainda, nesse período, na sala D, todas essas variáveis foram melhores para FITO, apesar da diferença ser meramente numérica, sugerindo efeito compensatório desse aditivo. O ATB promoveu menor FDD dos 21 aos 48 dias; no entanto, dos 35 aos 48 dias, FITO promoveu uma melhora mais rápida no quadro que CTRL. Não houve influência dos aditivos sobre a eliminação fecal de salmonelas, lesões histopatológicas no trato entérico ou sobre a oxidação lipídica na carcaça. Assim, a melhor CA na creche, e o efeito compensatório no final da fase de crescimento justificam futuras pesquisas sobre a ação do produto. / Despite the proven efficiency of antibiotics as growth promoters, issues associated to selection of microbial resistance and its impact over human health are rising concern between consumers and decreasing their use. Therefore, alternatives must be found, and medical herbs, with antimicrobial, antioxidant, immunomodulatory and stimulatory of digestives enzymes properties, seem promising. This study was carried out in order to evaluate the action of a phyogenic compound of medical herbs (Rosmarinus officinalis, Mentha piperita, Lippia sidoides and Lychnophora pinaster) towards piglets from weaning to slaughter, on performance parameters (body weight BW; average daily gain ADG; average daily feed intake ADFI; and feed conversion FC), frequency of diarrhea, fecal shedding of salmonellas, gut hystopatological lesions and lipid oxidation of meat, either under a challenged condition (C) or a non-challenged condition (NC). Experimental challenge consisted of oral administration of Salmonella typhimurium to piglets, at 35 days of age. Both groups were kept in isolated rooms. Experimental design was at random, and the treatments distributed in a 3x2 factorial arrangement. Factors were: challenge (C and NC) and additives (phytogenic compound PHYTO; antibiotic ATB; and control CTRL). 120 weaned piglets (21 days years old) were housed at nursery unit of Laboratory of Researche in Swine (LPS), and weighted at 21, 35, 49, 63 (nursery), 96, 105 (growing) and 131 (finishing) days of age. There was not interaction between factors. BW of ATB group was higher througout the experimental period. From 21 to 35 days of age, FC of ATB group was significantly lower than CTRL; however, PHYTO showed intermediary value, which did not statistically differ from both ATB and CTRL. Challenge caused lower ADFI from day 35 to 48. Nevertheless, at the final of growing period (96 to 105 days of age), there was a compensatory effect on performance, and animals out of C room had showed better values of BW, ADG, ADFI, FC than NC. At C room, such parameters were better for animals out of PHYTO group (although the differences were merely numerical), suggesting thus a compensatory effect of this compound. ATB has lead to lower FDD from day 21 to 48; however, from day 35 to 48, FDD of PHYTO group was lower than CTRL. There was not effect of additives on fecal shedding of salmonellas and on lipd oxidation of carcass. Further studies on the effect of the phyto compound must be carried out, especially during the growing and finishing periods.
102

A Psychometric Evaluation of the Compensatory Eating and Behaviors in Response to Alcohol Consumption Scale (CEBRACS)

Choquette, Emily M. 16 October 2017 (has links)
Drunkorexia refers to a set of disordered eating behaviors that occur in the context of a drinking episode for the purpose of 1) off setting caloric intake of the alcohol or 2) increasing the effects of alcohol. The Compensatory Eating and Behaviors in Response to Alcohol Consumption Scale (CEBRACS) was developed with the purpose of measuring drunkorexia behaviors at three time points: before, during, and after a drinking episode. The purpose of this study was to further validate the measure for use in men and women by examining measurement invariance, reliability, and validity. First, single group confirmatory factor analyses (CFA) were conducted separately by gender to examine the underlying factor structure of the measure. The two groups independently showed similar factor structure. The factor structure for both men and women indicated the removal of the original CEBRACS Restriction subscale. A multi-group CFA was conducted on the modified factor structure using gender as the grouping variable. This revised measure was found to have scalar invariance suggesting that means and variances of this measure can be compared. The current study addressed several limitations of previous measurement validation studies including a large diverse sample and thorough examination of the psychometric properties of the CEBRACS. This work provides additional evidence supporting the validity of the CEBRACS and suggests measurement invariance between genders.
103

Mecillinam Resistance in E. coli : fitness, compensation, and resistance in different environments

Ekstrand, Emelie January 2017 (has links)
The global increase of antibiotic resistant bacteria threatens the modern health care and challenges the therapeutic effects of available antibiotics. The b-lactam mecillinam (Mec) is an exception to this due to a stable clinical resistance prevalence resistance of approximately 3%. It is only used to treat uncomplicated urinary tract infections (UTIs), mainly caused by E. coli. Mecillinam resistance (MecR) is easily selected for in laboratory settings and linked to >40 genes, including the mrdA gene encoding the Mec target penicillin-binding protein 2. A majority of the known MecR mutations confer a severe fitness cost. Fitness is important for bacteria to survive in the bladder and clinical isolates have been shown to have high fitness. These isolates contain loss-of-function mutations in the cysB gene, which encode a positive regulator of cysteine biosynthesis. In a previous evolution experiment, fitness cost of cysB and mrdA MecR mutations was compensated and the compensatory mutations were identified. Here the compensatory mutations were reconstructed into wildtype (WT) E. coli strain MG1655, and cysB and mrdA backgrounds to study the impact of the mutations on resistance and fitness, using MIC tests and Bioscreen C assays. Our results show that the mrdA mutants only had partial fitness compensation (significantly lower fitness than WT) for all strains and all strains also increased their MecR. The low fitness is possibly an explanation for the lack of mrdA mutants outside laboratories. Of the clinically relevant cysB mutants the majority lost their resistance when increasing growth rate, some even to levels significantly higher than WT, indicating that DcysB mutations are easier to compensate for. One strain (ydjNmx2) however, had a significantly higher growth rate while remaining clinically MecR.
104

Kompenzační cvičení jako doplněk tréninkového plánu dětí mladšího školního věku v krasobruslení / Compensation exercise like a supplement of young school age children in figure skating

Nowická, Eva January 2017 (has links)
Title: Compensatory exercise as a complement to the training schedule for children of younger school age in figure skating Objectives: The main aim of this work is to highlight muscle dysbalance and their subsequent weakening and hypermobility in younger school age children in figure skating. Based on these weaknesses, create a stack of release, stretching and exercise exercises that can be used under any circumstances. Methods: In my work, I used a Janda muscle test, an analytical method that was focused on determining the strength of each muscle group. In individual tests, we are not only measuring the muscular strength of the main muscle, but we also investigate and analyze the performance of the whole movement. I was based on qualitative and quantitative values. Results: The measured data were compared and evaluated according to the literature. The impact of one-sided load in the long-term sports practice of figure skating was confirmed. It has also been shown that these exercises can be used for this particular set of probands to compensate for unilateral loading and adjust the training so that compensatory exercises are part of the training. Furthermore, I managed to design a program that would reduce these weaknesses for this selected group of probands. Keywords: Figure skating, training,...
105

Persistence of the Larval Environment on Post-Metamorphic Performance and Population Dynamics in Amphibians

Charbonnier, Julie 01 January 2017 (has links)
Organisms with complex life cycles may experience diverse stressors during their development. Stressors experienced in early life stages may influence the quantity and quality of individuals in later life stages. However, it is unclear if these effects persist later in life and how they may influence population dynamics. This dissertation uses two amphibian species, the Western spadefoot toad (Pelobates cultripes) and the spotted salamander (Ambystoma maculatum) to explore how biotic and abiotic factors experienced in aquatic and terrestrial environments influence phenotype and survival. We use a combination of field mesoscosm studies, laboratory studies and modeling to explore how early life history stressors persist in diverse environmental contexts. In Chapter 1, pond drying and larval density negatively influence multiple aspects of phenotype in the Western spadefoot toad. In Chapter 2, reduced body size due to larval stressors persisted in the first year of life in spotted salamanders in both high and low terrestrial resource environments. Additionally, there was no relationship between size at metamorphosis and post-metamorphic terrestrial survival. In Chapter 3, low terrestrial moisture levels reduced post-metamorphic growth rates by reducing food intake in juvenile spotted salamanders from both high and low larval density treatments. In Chapter 4, we scale up the effects of reduced body size in the Western spadefoot toad to explore how reduced body size due to pond drying may influence population densities using a stage specific matrix model. Reduced body size, by delaying maturity, may reduce adult densities in the Western spadefoot toad. This dissertation suggests that life stages are highly interconnected, as stressors experienced early in life stage may persist through their effects on phenotype in the absence of compensatory mechanisms. Variation in later life stages may also influence phenotype, but may not completely erase effects of early environments. Stressors experienced early in life may also translate to population level consequences, especially when organisms experience multiple stressors across life stages.
106

An investigation into the perceptions of the first year mathematics students towards the alternative mode intervention : UNAM case study / Investigation into the perceptions of the first year mathematics students towards the alternative mode intervention : University of Namibia case study

Iipinge, Reginald Kaleke January 2013 (has links)
A number of tertiary institutions offer bridging courses and intervention programmes in order to increase the number of students performing well in first year mathematics. At the university of Namibia, the science faculty provides educational opportunities to students who have not met the requirements to proceed with MAT 3511 (Basic Math). Unfortunately, the majority of students are not able to cope with the first year modules in Mathematics and the pass rates are unacceptably low. In the interest of supporting students, the University was prompted to introduce a two mode intervention programme in first year mathematics, namely: the normal mode and the alternative mode intervention. The alternative mode intervention was designed to improve the mathematics achievement of first year students who are considered low achieving or at risk of failure. This programme involves the identification of the lowest attainers in first year mathematics, and the provision of professional and faculty trained tutors and individualized teaching to these students in order to advance them to a level at which they are likely to learn successfully in a normal mode system. This research explores the experience and perceptions of first year students on the alternative mode, in particular as it relates to mathematical strands of proficiency. A second step was to explore how teaching contributes to the learning of mathematics on the intervention programme. The empirical investigation was done in 4 phases. A questionnaire on mathematics teaching and learning was given to the students during the first phase. During the second phase, two focus group discussions were conducted. Thereafter four interviews were carried out with lecturers, and finally tutorial and lecture observation were conducted. An analysis of these findings led to the identification of the students’ experiences on the alternative mode. Analysis of the results indicate that the students identified mathematical proficiency as the central element to their learning, and pedagogical knowledge and exploratory talk were critical aspects of good teaching in the mathematical intervention programme.
107

The Relative Roles of Herbivore- and Pollinator-mediated Selection on the Evolution of Floral Display in the Invasive Plant, Lythrum salicaria

Thomsen, Christina January 2015 (has links)
Studies assessing the evolution of plant traits frequently focus on pollinators as the primary drivers of floral trait evolution. However, herbivores can also play a role, and, under some circumstances, may even impose stronger selection on floral display than pollinators. This is especially true when the traits under selection are linked to anti-herbivore defense. Here I describe a study in which I quantified the relative role of herbivores and pollinators in selection for floral traits in the North American invasive plant, purple loosestrife (Lythrum salicaria). Because L. salicaria responds to leaf-chewing herbivores by producing compensatory tissue growth, and this in turn alters the architecture of the floral display, I further tested whether herbivores can indirectly modify pollinator-mediated selection through this pathway. Using a split-plot design, I measured pollen limitation and reproductive output in experimentally manipulated plants in the presence and absence of simulated herbivore damage in order to quantify the effects of damage and pollination on natural selection for floral display. My results showed that damage significantly increased direct selection (beta-i) for earlier flowering time and decreased selection on the number of inflorescences, even more than pollinators did. Because damage did not modify pollinator-mediated selection for floral display traits, the selection imposed by herbivores is likely only having direct effects. My findings demonstrate the importance of considering multiple agents of selection and their potential interactions when quantifying natural selection in a study system. In particular, it is important to consider that the agent most frequently studied may not be imposing the brunt of selection.
108

Vývoj kurzové politiky ČR a vlivy na obchodní bilanci / Development of the Czech exchange rate policy and its effects on the balance of trade

Gajdušková, Kateřina January 2008 (has links)
This thesis focuses on the development of exchange rate policy in the Czech Republic and its effect on the balance of trade. The first part considers the exchange rate and its regimes, balance of trade and factors that determine them. The most of the exchange rate theories is not valid in the Czech Republic, it is caused by the fact that the development of the exchange rate is influenced by all the factors together. In my thesis there I concerned with the exchange rate compensatory mechanism in more detail. The relation between the exchange rate and the balance of trade is in the case of small open economy like the Czech Republic evident, but the exchange rate is not always the determined factor that affects the final height of Czech exports or imports. These facts are confirmed in the second part of this thesis that analyses the development of exchange rate policy in the Czech Republic during the period 1993-2008.
109

Essays in materialism and compensatory consumption / Essais sur le matérialisme et la consommation compensatoire

Rustagi, Nimish 15 September 2017 (has links)
Cette thèse, constituée de trois essais, porte sur les concepts interdépendants de matérialisme et de consommation compensatoire. Le premier essai passe en revue les différentes conceptualisations du matérialisme, ainsi que ses causes et ses conséquences. J’analyse comment les différentes conceptualisations peuvent expliquer les variations des travaux de recherche et je propose un cadre conceptuel général pour analyser la recherche sur le matérialisme. Je présente également les travaux sur la notion de consommation compensatoire qui renvoie à l'utilisation et à la possession de biens matériels pour faire face aux menaces portant sur l’identité personnelle. Pour conclure ce premier essai, j’ouvre le débat sur l’opportunité de plusieurs travaux de recherche portant sur la consommation compensatoire. Dans les deux essais suivants, j’approfondis plus particulièrement les questions liées à la consommation compensatoire.Dans le deuxième essai, je reviens sur les recherches montrant que dédommager des aspects menacés de l'identité personnelle avec des produits symboliques (c'est-à-dire la consommation compensatoire intra-domaine) provoque des personnes pour ruminer les menaces sur leur identité personnelle et diminue leur ressources de maîtrise de soi.Je constate qu'une telle diminution arrive uniquement lorsque les produits sont explicitement liés avec les aspects menacés de leur identité personnelle et non quand ils sont implicitement liés avec les aspects menacés.Le troisième essai se focalise sur l'efficacité de la consommation compensatoire intra-domaine et plus précisément sur la possibilité de restaurer les éléments endommagés de l'identité personnelle. Mes résultats montrent que la restauration de l'identité personnelle est contrariée lorsque les individus sont rétribués avec des produits ayant des liens explicites avec les aspects menacés de leur identité personnelle et non lorsque ces liens sont implicites. Les liens explicites rappellent aux consommateurs les menaces et empêchent le processus de réparation de l'identité personnelle. Je teste également une condition limite de ces résultats et montre que lorsque la menace sur l’identité personnelle est implicite (par exemple, subtile ou non évidente), même les produits ayant des liens explicites peuvent permettre la réparation de l'identité personnelle. / This dissertation comprises three essays that pertain to the interelated constructs of materialism and compensatory consumption. In Essay 1, I review research on the conceptualizations, causes, and consequences of materialism, analyze how adopting different conceptualizations may account for variations in research outcomes, and suggest a broad framework for analyzing materialism research. I also introduce research on compensatory consumption, which refers to the use and possession of material goods to address self-identity threats. In the end, I discuss some ideas for future research, particularly those related to compensatory consumption. In the next two essays, I investigate specific questions on compensatory consumption. In Essay 2, I revisit extant research that shows that compensating with products symbolic of threatened aspects of self-identity (i.e., within-domain compensatory consumption) causes threat-related rumination and depletes self-control resources of individuals. I find that such depletion occurs only when products are explicitly connected to the threatened aspects of self, and not when they are implicitly connected to the threatened aspects. In Essay 3, I examine the efficacy of within-domain compensatory consumption, that is, whether it restores self-identity on aspects damaged by a self-threat. I find that self-identity repair is thwarted when threatened individuals compensate with products having explicit connections to the threatened identity domain, but not when these connections are kept implicit. Explicit, but not implicit, connections remind consumers of the threat, thereby impeding self-repair. I also test a boundary condition to these finding, and show that when the self-threat itself is implicit (e.g., subtle, non-obvious), even products with explicit connections can provide self-repair.
110

The Langa enrichment programme : a study of students' perceptions of the performance of the programme, undertaken to improve its functioning

Ismail, Salma January 1993 (has links)
Bibliography: p. 104-111. / This study focuses on the Langa Enrichment Programme an educational support programme for black students studying under the Department of Education and Training in the Cape Peninsula. The study aimed to determine students' reasons for attending the programme, their perceptions of its strengths and weaknesses and their recommendations for improvements. Student expectations of the programme and reasons for the high dropout rate especially amongst Standard Nine and female students were explored. To contextualise the study and to give further insights into student views a brief summary of the apartheid education crisis is given. Educational support programmes are reviewed as is liberalism's response to the crisis in education and the history and culture of the South African Institute of Race Relations. The methodology used was two-fold: self-administered questionnaires to 126 Standard 10 Mathematics students and a series of focus group interviews with small groups of students. The findings may be summed up as follows. Students were generally positive towards the teachers, teaching methods and administration of the programme. They requested that teachers should teach and complete the syllabus, emphasizing exam questions, revision and scientific experiments, and explore alternative small group teaching with critical discussions. Students also requested a comprehensive career guidance programme, bursary information and increased financial assistance. Students expressed a reluctance to pay fees and this, coupled with increasing requests for financial and educational supp01t, raises the issue of welfarism on the programme. Reasons for the high dropout rate amongst Standard Nines included that they write an internal examination. Social pressures from boyfriends and peer groups and regarding clothes were given as reasons for female students dropping out of the programme. The students appear to determine the direction of the school in that as a result of their demands the programme has changed from an enrichment programme to a compensatory one. Recommendations in the concluding chapter of this study are that the Enrichment Programme should draw up clearer policy guidelines in conjunction with staff and students; liaison with DET secondary schools, tertiary institutions and other enrichment programmes should be improved; career guidance programmes linked to bursary information should be implemented; bursaries and other incentives should be linked to attendance and academic performance on the programme; a full time co-ordinator should be employed.

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