Orientador: Julio Cesar Hadler Neto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-14T00:38:48Z (GMT). No. of bitstreams: 1 Paulo_SergioRobertode_D.pdf: 11219910 bytes, checksum: 29879b3a905822ab635c07217eb478f0 (MD5) Previous issue date: 1991 / Resumo: Não informado / Abstract: The subject of this work concerns with the measurement of absolute calibration factors for the use of CR-39 as an absolute detector in indoor radon and daughters monitoring. The word 'absolute' here means independence on environmental conditions like ventilation, electrostatic fields, size distribution of aerosols, etc. Up to now the usefulness of calibration factors was restricted to environmental conditions equal (or very close) to those worthing during their determinations. This fact is consequence of the difficulties related to the understanding of the plate-out properties of radon daughters activity in the air. So we devoted some time studying the plate-out effects on radon daughters monitoring performed by SSNTDs [Bi(88); Bi(89) -see chapter 5]. Our experimental results are in agreement with those of other authors about the great sensitivity of CR-39 to the plate-out effects, fact that recommended its use in this work. Being succeeded in the employment of CR-39 as an a-spectrometer we concluded that some important information¿s (like the radon daughters deposition sates on the walls of an environment) can be achieved [Had(91)]. The knowledge about the behavior of plate-out (which is precisely what obstructs the accomplishment of absolute calibration factors) made possible the determination of the ranges in zenital angle and energy where CR-39 can detect a-particle with efficiency of ~ 100%, at out conditions of track observation. In this way, we obtained calibration factors for CR-39 that are weakly dependent on environmental conditions (see chapters 9 and 10). We thin that these results can contribute to the improvement of RD detection techniques / Doutorado / Física / Doutor em Ciências

Orientador : Shirlei Maria Recco-Pimentel / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-14T01:25:03Z (GMT). No. of bitstreams: 1 Feitosa_VeraLuciaCorrea_M.pdf: 4439738 bytes, checksum: 32a3cf6b2be3ee5c4afc06269ab45a1a (MD5) Previous issue date: 1989 / Resumo: O Morro do Ferro, situado no Planalto de Poços de Caldas (MG) é uma região que apresenta umá elevada radioatividade natural (131,4. mSv /ano), uma das mais intensas do mundo. Foi estudada neste trabalho a possível influência da radioatividade desta regiào sobre a estrutura cromossômica de duas espécies de anfíbios anuros, Aplastodiscus perviri­dis e Hyla albopunctata. Como controles foram estudados A. perviridis das regiões de Botucatu (SP) e Serra da Bocaina (SP) e H. albopunctata provenientes de Botucatu e "Campus" da UNICAMP (Campinas, SP). Diante da hipótese de que a população de A. perviridis do Morro do Ferro pudesse não se tratar da mesma espécie daquela da Serra da Bocaina, o cariótipo foi determinado também para a população desta localidade. Os órgàos usados para análise citológica foram os testículos, intestino, baço, esôfago e medula óssea. As lâminas foram preparadas por métodos convencionais de esmagamento e suspensão de células. Verificou-se que A. pcrviridis do Morro do Ferro, Botucatu Serra da Bocaina apresenta um nÚmero diplóide de 2n = 24 Cfomossomos, semelhança cariotípica entre as três populações. Tanto A. perviridis como H. albopunctata apresentaram alteraçôes classificadas como: compactação, descompactação, quebras, falhas, deleção, fragmentos acêntricos e cromossomo dicêntrico. Parte destas alteraçôes provavelmente são decorrentes da alta radioatividade natural existente no Morro do Ferro. Alguns animais de H. albopundala do "Campus" da UNICAMP (Campinas) apresentaram uma freqüência de alterações relativamente superior à dos demais controles, o que foi atribuído à possível presença de algum mutagênico químico na lagoa onde os mesmos se desenvolveram e foram coletados. Foram encontradas diferenças individuais entre os indivíduos das amostras de todos os locais estudados, possivelmente devido a diferenças genotípicas inerentes a cada animal, idade e/ou dose de radiaçâo recebida. Nos intestinos e nos testículos ocorreram maior número de alterações do que nos outros órgâos e tecidos analisados. Na linhagem germinativa apenas as espermatogônias apresentaram metáfases alteradas. As alterações que apareceram com maior frequencia foram as deleções e quebras. Dessas um número relativamente grande ocorreu na vizinhança da heterocromatina centromérica. As alterações encontradas representam um grande potencial de rearranjos cromossômicos, com consequências não só para a sobrevivência dos individuos mas, principalmente, para a diversificação nas populações naturais / Abstract: Morro do Ferro, located in the Poços de Caldas Plateau in the State of Minas Gerais, has a radiation level as high as 131.4 mSv/year, suggesting on of the highest mean levels reported anywhere in the world. In this research the possible effect of the natural radiation in the Morro do Ferro on chromosomal structures was studied in two species of Anura Amphibia, Aplastodiscus perviridis and Hyla albopunctata. For A: perviridis the controls were collected in the Botucatu (SP) and Serra da Bocaina (SP) regions and for H. albopunctata in Botucatu (SP) and Campinas (SP). Considering the hypothesis that the Morro do Ferro population of A. perviridis might not be the same species as that of Serra da Bocaina. the karyotypes of both were determined. The chromosomes were obtained from the testicles, intestine, spleen, oesophagus and bone marrow. The slides were prepared by conventional squashing techniques and hy cell suspensions. The results showed that A. perviridis from Morro do Ferro, Serra da Bocaina and Botucatu presented the same diploid number 2n = 24 chromosomes and karyotipic similarity amongst the three populations. The chromosomic alterations appearing in both species were characterized as: condensation, decondensation, breaks, faults, deletions, acentric fragments and dicentric chromosomes. The majority of these alterations could probably be attributed to the high level of natural radiation in Morro do Ferro. The frequency of altered metaphases for some animais collected at UNICAMP (Campinas) was relatively higher than in the other controls. This was attributed to the presence of some mutagenic chemicals in the lagoon where the animais developed and were collected. Differences in the frequency of altered metaphases amongst the vanous individuals from all the localities studied were found. This was probably related to genotipic differences inherent to each animal and /or its age and radiation exposure. As expected, in the intestine and testicles the number of altered metaphases was greater than in the other organs analysed. In the germinative cell lineage only the spermatogonia presented altered metaphases. The compacted and decompacted chromosomic portions were those which showed the least drastic alterations, due to the possibility of reversion. Deletions and breaks were the more frequent alterations in both species, and a great number of these occurred in the centromeric hetero­chromatin neighborhood. The types of alteration encountered represent all enormous potential for chromosomic arrangements. These could bring about consequences not only for the individual itself, but principally in the diversification of the natural populations / Mestrado / Biologia Celular / Mestre em Ciências Biológicas