Thesis--University of the Witwatersrand. / Bibliography: p. [363]-384.

Thesis (PH.D.)--Michigan State University. Biochemistry and Molecular Biology, 2008. / Title from PDF t.p. (viewed on Aug. 11, 2009) Includes bibliographical references. Also issued in print.

Thesis (M.I.N.C.) -- Lincoln University, 2008. / Also available via the World Wide Web.

Thesis (D.Phil(Zoology))--University of Pretoria, 2005. / Includes bibliographical references Available on the Internet via the World Wide Web.

Made available in DSpace on 2014-06-11T19:35:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2001-02-21Bitstream added on 2014-06-13T21:07:59Z : No. of bitstreams: 1 lima_jfs_dr_rcla.pdf: 2743915 bytes, checksum: 1c051fa4de489a04cb215276b7d9ad67 (MD5) / Foram coletados exemplares roedores de pequenos porte em diversas localidades do estado do Tocantins, distribuídas em 3 tipos de região de acordo a vegetação predominante: Norte sob a influência da Floresta Amazônica, Centro-Sul e Leste sob influência do Cerrado e Médio Araguaia constituído pelo complexo da Ilha do Bananal. As preparações cromossômicas foram submetidas à coloração convencional, assim como às técnicas de bandas G, C e RON. Diferenciação cromossômica foi produzida nos cromossomos de alguns indivíduos, após tratamento das células com brometo de etídio. Foram cariotipados um total de 102 exemplares distribuídos em 9 gêneros e 12 espécies: Bolomys lasiurus (2n=34 e NA=34), Calomys tener (2n=66 e NA=66), Calomys sp.n. (2n=46 e NA=66), Nectomys rattus (2n=52, 53 e NA=52, 54), Oligoryzomys flavescens (2n=64 e NA=66), Oligoryzomys sp.n. (2n=70 e NA=76), Oryzomys megacephalus (Cariótipo A com 2n=54 e NA=62; Cariótipo B com 2n=52/53 e NA=58/60), Oryzomys gr. subflavus (2n=46 e NA=56), Rhipidomys macrurus (2n=44 e NA=48), pertencentes à família Cricetidae; Proechimys roberti (2n=30 e NA=54), Trichomys apereoides (2n=30 e NA=54), pertencentes à família Echimyidae; e Rattus rattus (2n=38 e NA=58), pertencente a família Muridae. Da espécie Oecomys gr. concolor, não obtivemos preparações cromossômicas. A grande maioria das espécies tem ocorrência relatada para as regiões Norte e Centro-Oeste do Brasil e a respectiva cariologia já é conhecida. Observa-se que os cariótipos encontrados são, de maneira geral, similares ou idênticos àqueles descritos na literatura, com raros casos de polimorfismos cromossômicos. Alguns exemplares da / Small rodents were collected at different sites in the state of Tocantins, distributed into three types of region according to the predominant vegetation: North, under the influence of the Amazon Forest, Mid-South and East under the influence of the Cerrado, and Middle Araguaia consisting of the complex of Bananal Island. The chromosomal preparations were submitted to conventional staining, as well as to G, C and NOR banding techniques. Chromosome differentiation was produced in the chromosomes of some individuals, after cell treatment with ethidium bromide. A total of 102 specimens were karyotyped, and they were distributed into 9 genera and 12 species: Bolomys lasiurus (2n=34 and NA=34), Calomys tener (2n=66 and NA=66), Calomys sp.n. (2n=46 and NA=66), Nectomys rattus (2n=52, 53 and NA=52, 54), Oligoryzomys flavescens (2n=64 and NA=66), Oligoryzomys sp.n. (2n=70 and NA=76), Oryzomys megacephalus (Karyotype A with 2n=54 and NA=62; Karyotype B with 2n=52/53 and NA=58/60), Oryzomys gr subflavus (2n=46 and NA=56), and Rhipidomys macrurus (2n=44 and NA=48), belonging to the family Cricetidae; Proechimys roberti (2n=30 and NA=54) and Trichomys apereoides (2n=30 and NA=54), belonging to the family Echimyidae, and Rattus rattus (2n=38 and NA=58), belonging to the family Muridae. Chromosome preparation from Oecomys gr. concolor were not obtained. The majority of the species have been reported to occur in the Northern and Mid-Western regions of Brazil and their karyology is already known. The...(Complete abstract click electronic access below)

Made available in DSpace on 2014-08-13T14:50:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-04-26Bitstream added on 2014-08-13T18:00:49Z : No. of bitstreams: 1 000753173.pdf: 1982685 bytes, checksum: 3e3cf8bcc5e8c696d40a552890c6657d (MD5) / A leptospirose é uma enfermidade infecto-contagiosa causada por diversas cepas da bactéria Leptospira interrogans, as quais infectam animais domésticos, silvestres e o homem. Os animais silvestres podem exercer papel fundamental na epidemiologia da doença, devido a grande disseminação de leptospiras para o meio ambiente e a possibilidade de infecção entre os animais e o homem, constituindo-se, portanto, em uma importante zoonose. Quando esses animais vivem em cativeiro, como em zoológicos, a infecção e a disseminação de patógenos podem ocorrer entre os animais silvestres do próprio zoológico, animais sinantrópicos, funcionários e o público visitante. Com o intuito de conhecer melhor a ocorrência e epidemiologia da leptospirose em animais silvestres e também em roedores sinantrópicos comensais, que co-habitam o local, foi realizado um estudo com animais em cativeiro e de vida livre, procedentes do Centro de Conservação da Fauna Silvestre de Ilha Solteira- SP (CCFS). Foram colhidas amostras sanguíneas de 41 animais em cativeiro e de 59 animais de vida livre, assim como 13 amostras de rim e fígado de ratos. As técnicas diagnósticas utilizadas foram a Soroaglutinação Microscópica (SAM), Reação em Cadeia pela Polimerase (PCR) para Leptospira spp. e cultivo de rim e fígado de ratos em meio de Fletcher. Pela SAM obteve-se 89 (89%) amostras positivas para um ou mais sorovares de Leptospira spp.; com prevalência do sorovar Andamana. Para a pesquisa do agente em fragmentos de fígado e rim dos ratos, 13 amostras de cada tecido foram cultivadas em meio de Fletcher, apresentando sete (53,8%) amostras positivas, sendo três amostras de rim e quatro de fígado e todos os animais com sorologia positiva. Pela técnica de PCR a partir do sangue dos animais de vida livre e em cativeiro 38 animais (38%) foram positivos para Leptospira spp., a partir de órgãos (rim e fígado) dos roedores sinantrópicos ... / Leptospirosis is a disease caused by various strains of the spirochete bacterium Leptospira interrogans, which can infect domestic and wildlife animals, as well humans. Wild animals may play a key role in the epidemiology of the disease, due to the large spread of leptospires into the environment and the possibility of infection between animals and man, becoming therefore an important zoonosis. When these animals live in captivity in zoos, the infection and spread of pathogens can occur between the wild animals of the zoo itself, synanthropic animals, employees and visitors. In order to better understand the occurrence and epidemiology of leptospirosis in wild animals and in synanthropic rodents, which co-inhabit the place, a study was conducted with free-living animals and in captivity, found in Wild Fauna Conservation Center from Ilha Solteira-SP. Blood samples were collected from 41 animals in captivity and 59 free-living animals, as well as 13 samples of kidney and liver of rats. The diagnostic techniques used were the Microscopic Agglutination Test (MAT), the Polymerase Chain Reaction (PCR) and cultivation in Fletcher medium. MAT was positive in 89 (89%) samples for one or more serovars of Leptospira spp., with prevalence of serovar Andamana. For the research of agent into fragments of liver and kidney of rodents, 13 samples of each fragment were grown in Fletcher medium, with seven (53,8%) positive samples (three kidney samples and four liver samples). All rats were reactive by MAT. Related to PCR from the blood of free-living animals and in captivity, 38 animals (38%) were positive for Leptospira spp.; nine rodents (69,2%) presented positive fragments at PCR and four animals (30,8%) presented positive samples of the culture of the fragments at PCR for Leptospira spp. According to the results, we observed the occurrence of infection among the animals, needing the adoption of prophylactic measures to control this zoonosis in this place

Para o Brasil foram reportadas 53 espécies de ácaros trombiculídeos. Destas, 5 espécies parasitam anfíbios, 6 espécies parasitam aves, 4 espécies parasitam répteis, 25 espécies parasitam roedores, 8 espécies parasitam marsupiais e 12 espécies parasitam outros mamíferos (incluindo humanos). Assim que os primeiros casos de Febre Maculosa Brasileira (FMB) foram diagnosticados em São Paulo nos anos 30, os ácaros hematófagos, como os trombiculídeos, foram sugeridos como potenciais vetores. No entanto, o papel desses ácaros na epidemiologia da riquetsiose não foi confirmado. Dessa forma, a situação fragmentária dos registros de ocorrência dos trombiculídeos, sua complexidade taxonômica e a escassez de informações sobre sua participação na epidemiologia de riquétsias, foram os principais motivos que levaram à proposição do presente estudo. Com isso, os ácaros que estão depositados nas coleções acarológicas do Instituto Butantan (IBSP), do Museu de Zoologia da USP (MZUSP) e da FIOCRUZ (CAVAIS-IOC), foram examinados e identificados. Igualmente, aqueles obtidos de roedores e marsupiais coletados em algumas localidades do estado de São Paulo e Paraná foram também identificados, bem como, investigados para a presença de Rickettsia spp. No total, foram identificadas as espécies Arisocerus hertigi, Eutrombicula sp. n., Kymocta brasiliensis, Quadraseta azulae, Q. brasiliensis, Q. mackenziei, Q. mirandae e Trombewingia bakeri. Além do encontro da nova espécie de Eutrombicula sp. n., foi ainda constatado que E. butantanensis e E. alfreddugesi são espécies distintas. As espécies Q. azulae, Q mackenziei e Q. mirandae, são assinaladas pela primeira vez no país. Com excessão de Q. brasiliensis em M. americana, todos os hospedeiros são novos registros para as espécies de ácaros examinados, bem como todas as localidades são novos registros de ocorrência. Assim, o número de espécies de trombiculídeos no Brasil aumentou para 59. Os ácaros investigados para Rickettia foram também preservados em lâminas, como testemunhos. Entretanto, nos espécimes analisados, a presença da bactéria não foi detectada. / For Brazil were reported 53 species of chigger mites. Of these, 5 species parasitize amphibians, 6 species parasitize birds, 4 species parasitize reptiles, 25 species parasitize rodents, 8 species occur on marsupials, and 12 species parasitize other wild mammals (including humans). In the 30s, as soon as the first cases of Brazilian Spotted Fever (BSF) in São Paulo were diagnosed, the haematophagous mites, such as chiggers, were suggested as potential vectors. However, the role of these mites in the epidemiology of the rickettsiosis was not confirmed. Thus, the fragmentary situation of the records of the chigger mites' occurrence, their taxonomic complexity, and the lack of information about their participation in the BSF epidemiology, were the main reasons that led to the present study proposition. So, the mites deposited in the collections of the Instituto Butantan (IBSP), Museu de Zoologia of USP (MZUSP) and FIOCRUZ (CAVAIS-IOC), were identified. Also, those obtained from rodents and marsupials collected in some localities of the state of São Paulo and Paraná were identified and investigated for the presence of Rickettsia spp. In total, the species Arisocerus hertigi, Eutrombicula n. sp., Kymocta brasiliensis, Quadraseta azulae, Quadraseta brasiliensis, Quadraseta mackenziei, Quadraseta mirandae, and Trombewingia bakeri, were identified. Besides of the new specie of Eutrombicula sp. n., the mites E. alfreddugesi and E. butantanensis were found to be distinct species. The species Q. azulae, Q. mackenziei, and Q. mirandae, are highlighted for the first time in the country. Except for Q. brasiliensis in M. americana, all other hosts are new records for the species of examined mites, as well as all locaties are also new occurences. Thus, the number of chigger mite species in Brazil increased to 59. The mites investigated to Rickettsia were also preserved in slides, as voucher. However, in the analyzed specimens, the bacteria could not be detected.

This thesis describes an investigation of space use in least chipmunks at Kluane Lake, in the southwest Yukon. I examined demography, home range and habitat use patterns in the population. Based on live-trapping data from two grids over two summers, mean number of animals on the study area was 22.6/grid, similar to chipmunk numbers measured there over the previous four years. The population was lower than is generally found in the same species further south, although year-to-year stability was typical. Chipmunks preferred open forest and shrub-land to closed-canopy forest, which is also typical of the genus. Home range sizes measured using telemetry averaged 4.86 ha, higher than in any previously published study of the genus. I examined the relationship between social spacing and space use. Home range overlap averaged 93.4%; chipmunks do not appear to defend exclusive core areas. Provoked interactions among neighbours suggested that social dominance was based on age, weight, and breeding condition, rather than ownership of space. Although provoked interactions were generally aggressive, the telemetry data suggest that such behaviour was artifactual. Comparing the encounter frequency of radio-collared animals to that generated by a random model showed that chipmunks avoided encounters, except when harvesting seasonally abundant food. Grid-trapping did not increase food or cover availability enough to affect home range size. There was evidence that the presence of traps affected use distribution but not enough to invalidate trap-based home range estimates. Comparison of trap and telemetry based estimates of home range size yielded no significant differences. / Science, Faculty of / Zoology, Department of / Graduate

PhD (Zoology) / Department of Zoology / The order Rodentia is the most speciose group of mammals with muroids being the most diverse superfamily. Since they are represented in arboreal, semiaquatic, subterranean and terrestrial niches, rodents may exhibit morphological traits reflecting their adaptations to such diverse environments. This thesis focuses on the morphology of the endocranium, auditory bulla and cochlea in three tribes (Otomyini, Taterillini and Gerbillini) representing 10 species of African rodents, concentrating on their variability, function and adaptability, using micro-CT imaging and 3D shape comparative methods. Additionally, variations in cranial size were also studied in respective of global warming and climatic variables. Morphological changes/variations are a result of environmental change, therefore each chapter in this study details the effect of environmental change (in space and time) on different morphological traits i.e. general cranial size (chapter 2), cochlea and auditory bulla (chapter 3) and endocranial size and shape (chapter 4). With chapter 2 dealing specifically with climate change in its strict sense and the remaining two chapters looking at different environmental gradients. Chapter 2 tests the applicability of the “third universal response to warming” (i.e. declining body size) and the Resource Rule in two murid subfamilies, Murinae and Gerbillinae. The study shows that the third response is not as universal as only one species conformed to this response. Further, food availability (Resource Rule) was shown to be the more important factor correlated with body size variations in rodent species than Bergmann’s Rule. Chapter 3 looks at the auditory bulla and cochlea, the morphological traits that play a role in hearing capabilities of rodents. I found, with some exceptions, that bulla and cochlea modifications between species could be explained by environment, phylogeny and/or allometry. In addition, I concluded that true desert adapted laminate-toothed rats and gerbils use both bulla and associated cochlea hypertrophy. Chapter 4 shows larger brain size in Taterillini and two species of Otomyini, with life histories and environment being the most probably factors responsible for xiv this. Using a novel method of diffeomorphism (deformation models), there was more variation in endocranial morphology between the gerbils and laminate-toothed rats than within them with olfactory bulb, paraflocculi, and posterior ventral cortex showing the most variability. Overall, this thesis shows that variations in the morphological traits studied are strongly influenced by the environment and function. / NRF

Rats given L-Ascorbic Acid in their drinking water prior to and during starvation did not develop severe ulceration in the glandular portion of their stomachs. Control rats which were either nontreated or given deactivated L-Ascorbic Acid developed severe stomach pathology on the starvation regimen. The present study was based on the finding that food deprivation results in severe rumenal ulceration in rats. Given that L-AA is essential in maintaining tissue integrity and that ulcers are examples of tissue degeneration, the L-AA in large amounts could retard, or prevent, the formation of starvation induced stomach ulcers in rats. The results show that large amounts of active L-AA were beneficial in maintaining the integrity of rat gastrointestinal tissue exposed to starvation conditions which, in the vitaimin's absence, induces deterioration.