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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.
1

Controle seletivo do Rhipicephalus (Boophilus) microplus (Canestrini, 1887), em bovinos criados em campo nativo, com uso de fipronil e avaliação de sua eficácia em Lages SC / Selective control of Rhipicephalus (Boophilus) microplus (Canestrini, 1887), in cattle raised on natural pastures, with the use of fipronil and evaluation of their effectiveness in Lages-SC

Paim, Fernanda 25 March 2010 (has links)
Made available in DSpace on 2016-12-08T16:24:05Z (GMT). No. of bitstreams: 1 PGCA10MA032.pdf: 934515 bytes, checksum: aaff1e02f75a4eaee8f281f36d4eccb2 (MD5) Previous issue date: 2010-03-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present work consists of an analysis of the selective control of Rhipicephalus (Boophilus) microplus by fipronil, the cost reduction for such control and the measurement of the efficiency of that acaricide after three years of administration. The experiment was taken from May 2007 to april 2009 in a cattle farm 25 kilometers away from Lages, Santa Catarina state , in two areas of native pasture naturally infested by R. (B) microplus. Forty cattle were divided in two groups of 20 animals each. At each 14 days the female ticks, bigger than 4,5 mm located in the right side of the cattle bodies were counted. The result of that counting was multiplied by two. Fipronil 1% pour on was then administered. In the so-called Conventional Group all the cattle were treated when the average reached more than 40 female ticks per animal. In the so-called Selective Group, on the other hand, only the animals molested by more than 40 ticks received the dose. For both groups the prescription was albendozale sulfoxide )5 mg/kg), under skin administration (when the parasitic infection reached more than 250 eggs per gram EPG). At each 28 days the cattle s weight was checked for the cost/benefit analysis. It was verified a difference of doses of the acaricide on the Conventional group comparing the Selective one six doses of antihelmintics were administered for both groups. It was also verified that the cattle of the Selective Group gained 13.39 kg, on the average, more than the animals of the Conventional Group a significant difference (more than 5%) between the average weight of the two lots was not evidenced. In the experiment selective to verify the efficiency of the Fipronil 1%, 20 cattle, European-bred, were divided: ten animals infested by engorged female larva with selective (SG) and the other ten were infested by engorged female larva with selective (SG) and the other ten were infested by engorged female larva conventional (CG). Later, randomly, five animals were chosen for SG and CG control and five for SG and CG administration, infested according to the Agriculture, Cattle Breeding and Supplying Brazilian Ministry standards. The animals were infested by a minimum of 2.500 larva of an identified cepa of R. (B.) microplus, aged 10 to 21 days old. All ticks emerged from the bodies of the animals were collected from day minus-3 to day plus-23 of the experiment. These ticks were later counted and incubated so the viability of their eggs could be examined. The efficiency of the acaricide on the Fipronil 1% - basis calculated for the group infested by the SG cepa was 77.74%; for the group infested by the CG cepa, that as administered 14 treatments in three years of use, was 79,32%. The repressed-reproduction average was 22.57% for the SG group amd 22.47% for the CG group. On a Student s t test basis, significance 5%, the groups didn t show a statistic difference / A realização deste trabalho teve como objetivos avaliar o método de controle Seletivo do Rhipicephalus (Boophilus) microplus com fipronil, reduzir os custos com o seu controle e avaliar a eficácia deste carrapaticida após três anos de uso. O experimento foi realizado em uma propriedade rural a 25 km de Lages/SC, de maio de 2007 a abril de 2009, em duas invernadas de campo nativo, naturalmente infestadas com R. (B.) microplus. Utilizaram-se 40 bovinos que foram divididos em dois grupos de 20 animais. A cada 14 dias foi realizada a contagem das fêmeas maiores ou igual a 4,5mm, no lado direito do corpo dos animais, e o valor obtido, multiplicado por dois. O medicamento utilizado foi o fipronil 1% via pour on. Um grupo, denominado Convencional foi tratado todos os bovinos quando a média do grupo foi igual ou superior a 40 fêmeas, e o outro grupo, denominado Seletivo foi tratado apenas os animais que apresentaram uma infestação igual ou superior a 40. Ambos os grupos foram tratados com sulfóxido de albendazole (5mg/kg), por via subcutânea, (quando a infecção parasitária foi superior a 250 OPG. A cada 28 dias foi realizada a pesagem dos animais para análise da relação custo/benefício. Foram realizadas 20 aplicações a mais do carrapaticida no grupo Convencional em relação ao Seletivo. Ambos os grupos receberam seis tratamentos com anti-helmíntico. Foi calculado um ganho de peso médio de 13,39kg aos animais pertencentes ao Seletivo superior aos bovinos do grupo Convencional não ocorrendo diferença estatística significante entre as médias de peso dos dois lotes (significância de 5%). Um experimento para análise da eficácia do fipronil 1% foram utilizados 20 bovinos de raça européia que foram divididos: dez animais infestados com larvas provenientes das teleóginas do esquema de tratamento Seletivo (GS) e dez animais que foram infestados com larvas provenientes das teleóginas do esquema Convencional (GC), que posteriormente foram randomizados, estabelecendo 5 animais para controles (GCS) e (GCC) e 5 animais para tratados GTS e GTC. Infestados de acordo com a metodologia estabelecida pelo Ministério da Agricultura, Pecuária e Abastecimento MAPA. Os animais foram infestados com, no mínimo, 2.500 larvas com idade entre 10 a 21 dias de uma cepa de R. (B.) microplus. As coletas totais de carrapatos desprendidos do corpo dos animais a partir do dia 3 até o dia +23 do ensaio, que foram contadas e incubadas para análise da viabilidade dos ovos. A eficácia do tratamento carrapaticida utilizando fipronil 1% calculada para o grupo infestado com a cepa GS foi 77,74% e para o grupo infestado com a cepa GC que recebeu o total de 14 tratamentos durante os três anos de uso, foi de 79,32%. A porcentagem média de inibição de reprodução calculada foi 22,57% para o GS e 22,47% para o GC, aplicando-se o teste t de Student, nível de significância de 5%, não houve diferença estatística entre os grupos
2

Controle seletivo do estímulo em uma tarefa de emparelhamento com o modelo com palavras como estímulos compostos: análise de um procedimento de Resposta Diferencial de Observação (DOR) e estímulos com diferenças críticas e múltiplas

Wegbecher, Samira de Toledo 25 May 2012 (has links)
Made available in DSpace on 2016-04-29T13:17:46Z (GMT). No. of bitstreams: 1 Samira de Toledo Wegbecher.pdf: 1304034 bytes, checksum: 035df32061a11b66b4adccdc31c06aba (MD5) Previous issue date: 2012-05-25 / The aim of the present study was to evaluate the efficacy of a procedure that used Differential Observing Response (DOR) and stimuli with critical differences to eliminate the selective control in a simultaneously matching to sample task, applied in a participant diagnosed with autism spectrum disorders. Three words sets were used as stimuli, each set consisting of three words with three letters each and the last letter was the critical element. The experimental procedure was composed of baseline sessions, Training sessions with DOR condition and reversal test. Generalization tests were conducted with ME word set to investigate whether the control of all elements (letters) remained in spite of its position. The results of the baseline indicated that the participant was under control of the two initial words letters in critical differences trials. After the training procedure (DOR) selective control by the two initial letters was eliminated. The test results also indicated the reduction of the selective control in attempts when there was a variation of the position of the critical element. The using of a multiple baseline design could ensure greater methodological control for further research / O objetivo do presente estudo foi avaliar a eficácia de um procedimento que utilizou Resposta Diferencial De Observação (DOR) e estímulos com diferenças críticas para eliminar o controle seletivo em tarefas de emparelhamento simultâneo com o modelo, realizadas por um participante diagnosticado com transtorno do espectro do autismo. Foram utilizados como estímulos três conjuntos, cada um composto por três palavras formadas por três letras e a última era o elemento crítico ou diferente. O procedimento experimental foi composto por sessões de linha de base, treino na condição DOR e reversão. Para um dos conjuntos de palavras foram realizados testes de generalização a fim de investigar se o controle por todos os elementos (letras) se mantinha a despeito de sua posição. A análise dos resultados da linha de base demonstrou que o participante estava sob controle das duas letras iniciais nas tentativas com diferenças críticas. Após o procedimento de treino (DOR), o controle seletivo pelas duas letras iniciais foi eliminado. Os resultados nos testes também demonstraram a redução do controle seletivo nas tentativas em que houve a variação da posição do elemento crítico. A condução de delineamento com linha de base múltipla em novas pesquisas poderia assegurar maior controle metodológico
3

Procedimentos de intervenção para corrigir um déficit no controle de estímulos: uma revisão de estudos empíricos / Intervention procedures for correcting a deficit in stimulus control: a review of empiric studies

Corato, Luciana Lorenzi 17 October 2013 (has links)
Made available in DSpace on 2016-04-29T13:17:50Z (GMT). No. of bitstreams: 1 Luciana Lorenzi Corato.pdf: 1151009 bytes, checksum: 04d57b56af357d95340f01f89bb6dfab (MD5) Previous issue date: 2013-10-17 / A deficit in stimulus control that has been called overselectivity / restricted control / selective control occurs when only a limited number of environmental stimuli comes to control behavior at the expense of other aspects of the environment. This deficit has a high level of occurrence in people with atypical development, particularly in those with autism spectrum disorders, but it is not restricted to this population. The objective of this study was to review the experiments developed to evaluate procedures aimed to correct this deficit. A search was conducted on four databases, both in English and Portuguese, with the following keywords: restricted control, selective control and overselectivity. Eleven papers encompassing 16 experiments were found; the majority (13) conducted with people with atypical development, and the remaining with participants with typical development at different ages. Nine procedures have been identified employing tasks such as SMTS, DMTS, discrimination between two stimuli simultaneously presented, observing response procedures, differential observation response (DOR), compound DOR, overtraining, manipulation of the stimuli s characteristics, functional object-use and their graphic representations or photographs and fading. The stimuli presented during the discrimination tasks could be symbols, graphic representations, abstract figures, geometric shapes, words, photographs, drawings and concrete objects. Several experimental designs were employed to evaluate the effect of the intervention on the deficit in stimulus control, the majority (13 experiments) with repeated measures and the remaining comparing independent groups plus intra-subject designs. Various measures to evaluate stimulus control were employed and variable results were obtained. In almost all studies the procedures were able to reduce the deficit in stimulus control, although not totally. In some studies discriminative performance improved only when the procedure was in effect, but returned to baseline levels after its withdrawal / Um déficit no controle de estímulos que tem sido chamado de superseletividade/ controle restrito/ controle seletivo ocorre quando apenas um limitado número de estímulos ambientais adquire controle sobre as respostas do indivíduo em detrimento de outros aspectos do ambiente. Ocorre comumente em pessoas com desenvolvimento atípico, particularmente naquelas que apresentam o transtorno do espectro autista, mas não é exclusivo dessa população. O objetivo do presente trabalho foi fazer uma revisão de experimentos que visavam avaliar procedimentos para corrigir tal déficit. Foi realizada uma busca em quatro bases de dados a partir dos termos controle restrito, controle seletivo e superseletividade, em português e em inglês. Foram encontradas 11 publicações englobando 16 experimentos dos quais a maioria (13) foi realizada com pessoas com desenvolvimento atípico e os demais com pessoas com desenvolvimento típico com diferentes faixas etárias. O déficit no controle de estímulos foi avaliado através de diferentes procedimentos envolvendo diferentes tipos de tarefas. Foram identificados nove procedimentos que empregavam tarefas como SMTS, DMTS, discriminação com apresentação simultânea de dois estímulos, exigência de uma resposta de observação, resposta de observação diferencial (DOR), DOR composto, super-treino, manipulação das características dos estímulos a serem discriminados, emprego de objetos concretos e suas representações gráficas ou fotográficas e esvanecimento dos estímulos. Nas tarefas de discriminação os estímulos empregados podiam ser símbolos, representações gráficas, figuras abstratas, formas geométricas, palavras, fotografias e objetos concretos. Foram empregados diversos delineamentos experimentais para avaliar o efeito da intervenção sobre o déficit no controle de estímulos, sendo que a maioria (13 experimentos) realizou medidas repetidas dos mesmos participantes, e os demais empregaram delineamentos que compararam grupos independentes, além de utilizarem delineamentos intra-sujeitos. Foram utilizadas diversas medidas para avaliar o controle de estímulos e os resultados foram bastante diversos. Na quase totalidade dos estudos os procedimentos foram capazes de reduzir o déficit no controle de estímulos, embora não completamente. Em alguns estudos o desempenho discriminativo melhorou apenas quando o procedimento estava em vigor, mas voltou aos níveis basais após a sua retirada
4

Biophysics of helices : devices, bacteria and viruses

Katsamba, Panayiota January 2018 (has links)
A prevalent morphology in the microscopic world of artificial microswimmers, bacteria and viruses is that of a helix. The intriguingly different physics at play at the small scale level make it necessary for bacteria to employ swimming strategies different from our everyday experience, such as the rotation of a helical filament. Bio-inspired microswimmers that mimic bacterial locomotion achieve propulsion at the microscale level using magnetically actuated, rotating helical filaments. A promising application of these artificial microswimmers is in non-invasive medicine, for drug delivery to tumours or microsurgery. Two crucial features need to be addressed in the design of microswimmers. First, the ability to selectively control large ensembles and second, the adaptivity to move through complex conduit geometries, such as the constrictions and curves of the tortuous tumour microvasculature. In this dissertation, a mechanics-based selective control mechanism for magnetic microswimmers is proposed, and a model and simulation of an elastic helix passing through a constricted microchannel are developed. Thereafter, a theoretical framework is developed for the propulsion by stiff elastic filaments in viscous fluids. In order to address this fluid-structure problem, a pertubative, asymptotic, elastohydrodynamic approach is used to characterise the deformation that arises from and in turn affects the motion. This framework is applied to the helical filaments of bacteria and magnetically actuated microswimmers. The dissertation then turns to the sub-bacterial scale of bacteriophage viruses, 'phages' for short, that infect bacteria by ejecting their genetic material and replicating inside their host. The valuable insight that phages can offer in our fight against pathogenic bacteria and the possibility of phage therapy as an alternative to antibiotics, are of paramount importance to tackle antibiotics resistance. In contrast to typical phages, flagellotropic phages first attach to bacterial flagella, and have the striking ability to reach the cell body for infection, despite their lack of independent motion. The last part of the dissertation develops the first theoretical model for the nut-and-bolt mechanism (proposed by Berg and Anderson in 1973). A nut being rotated will move along a bolt. Similarly, a phage wraps itself around a flagellum possessing helical grooves, and exploits the rotation of the flagellum in order to passively travel along and towards the cell body, according to this mechanism. The predictions from the model agree with experimental observations with respect to directionality, speed and the requirements for succesful translocation.

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