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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.
21

What Explains Patterns of Diversification and Richness among Animal Phyla?

Jezkova, Tereza, Wiens, John J. 03 1900 (has links)
Animal phyla vary dramatically in species richness (from one species to >1.2 million), but the causes of this variation remain largely unknown. Animals have also evolved striking variation in morphology and ecology, including sessile marine taxa lacking heads, eyes, limbs, and complex organs (e.g., sponges), parasitic worms (e.g., nematodes, platyhelminths), and taxa with eyes, skeletons, limbs, and complex organs that dominate terrestrial ecosystems (arthropods, chordates). Relating this remarkable variation in traits to the diversification and richness of animal phyla is a fundamental yet unresolved problem in biology. Here, we test the impacts of 18 traits (including morphology, ecology, reproduction, and development) on diversification and richness of extant animal phyla. Using phylogenetic multiple regression, the best-fitting model includes five traits that explain approximate to 74% of the variation in diversification rates (dioecy, parasitism, eyes/photoreceptors, a skeleton, nonmarine habitat). However, a model including just three (skeleton, parasitism, habitat) explains nearly as much variation (approximate to 67%). Diversification rates then largely explain richness patterns. Our results also identify many striking traits that have surprisingly little impact on diversification (e.g., head, limbs, and complex circulatory and digestive systems). Overall, our results reveal the key factors that shape large-scale patterns of diversification and richness across >80% of all extant, described species.
22

The role of polymorphonuclear cells in immunity to Nematospiroides dubius infections in mice /

Penttila, Irmeli. January 1984 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Microbiology and Immunology, 1984. / Includes bibliographical references (leaves 113-128).
23

Conspecific brood parasitism in ruddy ducks (Oxyura jamaicensis)

Reichart, Letitia Marie, January 2008 (has links) (PDF)
Thesis (Ph. D.)--Washington State University, August 2008. / Includes bibliographical references.
24

Causes and consequences of variation in immunity within insect populations /

Robb, Tonia, January 1900 (has links)
Thesis (Ph.D.) - Carleton University, 2006. / Includes bibliographical references (p. 165-178). Also available in electronic format on the Internet.
25

Models of parasitism and hyperparasitism on Paralomis spinosissima /

Watters, George Murray, January 1997 (has links)
Thesis (Ph. D.)--University of California, San Diego, 1997. / Vita. Includes bibliographical references.
26

Conspecific nest parasitism in the Northern Masked Weaver /

Jackson, Wendy M. January 1990 (has links)
Thesis (Ph. D.)--University of Washington, 1990. / Vita. Includes bibliographical references (leaves [119]-130).
27

Model of kleptoparasitism in the Onthophagus taurus when to enter and leave a dung pat /

Allmond, Heather Ann. January 1900 (has links)
Thesis (M.A.)--The University of North Carolina at Greensboro, 2010. / Directed by Jan Rychtar; submitted to the Dept. of Mathematics and Statistics. Title from PDF t.p. (viewed Jul. 5, 2010). Includes bibliographical references (p. 54-57).
28

Helmintofauna associativa à anfíbios da Ilha Anchieta, litoral norte do estado de São Paulo, Brasil

Aguiar, Aline [UNESP] 28 February 2013 (has links) (PDF)
Made available in DSpace on 2014-08-13T14:50:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-28Bitstream added on 2014-08-13T18:00:34Z : No. of bitstreams: 1 000758239.pdf: 1005727 bytes, checksum: b67d66057a2c388cb3d5c5d8bbe8de7a (MD5) / Os anfíbios ocupam grande variedade de microhabitats refletindo os diversos modos reprodutivos, estilos de vida e parasitas que estes animais apresentam. Os parasitas são indicativos de muitos aspectos biológicos de seus hospedeiros, incluindo a dieta, ocupação do habitat e a filogenia, podendo também ser bons indicadores diretos do estado de qualidade ambiental. A Ilha Anchieta, parque estadual em área de Mata Atlântica, torna-se interessante para estudos biológicos devido a sua dinâmica insular e isolamento geográfico. O objetivo deste estudo foi avaliar a fauna de helmintos de 195 anfíbios da Ilha Anchieta representados por 14 espécies, Flectonotus fissilis (n = 18), Haddadus binotatus (n = 9), Ischnocnema bolbodactyla (n = 4), Ischnocnema parva (n = 20), Rhinella ornata (n = 20), Dendrophryniscus brevipollicatus (n = 3), Hypsiboas albomarginatus (n = 18), Scinax hayii (n = 23), Hylodes asper (n = 2), Hylodes phyllodes (n = 3), Leptodactylus cf. marmoratus (n = 42), Leptodactylus latrans (n = 4), Chiasmocleis carvalhoi (n = 26) e Myersiella microps (n = 3). Foram identificadas pelo menos 14 espécies de helmintos entre as comunidades componentes dos anfíbios: 12 espécies de nematóides (Falcaustra mascula, Oxyascaris oxyascaris, Oswaldocruzia sp., Rhabdias sp., Physaloptera sp., Aplectana crucifer, Aplectana pintoi, Aplectana sp., Cosmocerca brasiliense, Cosmocerca parva, Cosmocerca travassosi e Cosmocerca sp.), uma espécie de cestóide (Cylindrotaenia cf. americana) e uma espécie de Acanthocephala (cistacantos). Este estudo apresenta uma revisão dessas espécies de helmintos com seus anfíbios hospedeiros até hoje relatados; a helmintofauna associada a estas espécies hospedeiras; e uma análise de similaridade das infracomunidades de algumas espécies de anfíbios, mostrando que o habitat pode influenciar na composição e abundância da comunidade parasita / The amphibians use a variety of microhabitats, relationship with the various reproductive modes, life style and parasites that these animals presented. The parasites are indicatives about a lot of biological aspects of yours hosts, including feeding, use of habitat and phylogeny. They also may be good indicators about status of environmental quality. The Anchieta Island, state park in Atlantic Rain Forest area, is very interesting for biological studies because insular dynamics and geographical isolation. The aim of this study was to evaluate the helminth fauna of 195 amphibians from Anchieta Island representing 14 species, Flectonotus fissilis (n = 18), Haddadus binotatus (n = 9), Ischnocnema bolbodactyla (n = 4), Ischnocnema parva (n = 20), Rhinella ornata (n = 20), Dendrophryniscus brevipollicatus (n = 3), Hypsiboas albomarginatus (n = 18), Scinax hayii (n = 23), Hylodes asper (n = 2), Hylodes phyllodes (n = 3), Leptodactylus cf. marmoratus (n = 42), Leptodactylus latrans (n = 4), Chiasmocleis carvalhoi (n = 26), and Myersiella microps (n = 3). They were necropsied to examine for helminth parasites. We identified at least 14 helminths species in the component communities of anurans: 12 nematodes species (Falcaustra mascula, Oxyascaris oxyascaris, Oswaldocruzia sp., Rhabdias sp., Physaloptera sp., Aplectana crucifer, Aplectana pintoi, Aplectana sp., Cosmocerca brasiliense, Cosmocerca parva, Cosmocerca travassosi, and Cosmocerca sp.), one cestode species (Cylindrotaenia cf. americana), and one species of Acanthocephala (cystacanths). This study presents a revision about these helminth species with the related hosts to date; the helminth fauna associated to these host species; and the similarity about infracommunities of some amphibian species, showing habitat can influence on composition and abundance of parasite community
29

Avaliação biológica e biotecnológica de uma serpina (CfSerpina) do endoparasitoide Cotesia flavipes Cameron, 1891 (Hymenoptera: Braconidae) sobre o seu hospedeiro Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) /

Silva, Juliana Barroso January 2018 (has links)
Orientador: Guilherme Duarte Rossi / Banca: Ana Maria Guidelli Thuler / Banca: Fernando Luis Cônsoli / Banca: Manoel Victor Franco Lemos / Banca: Odair Aparecido Fernandes / Resumo: Os parasitoides são insetos que utilizam outros insetos para se desenvolverem e completarem seu ciclo imaturo de desenvolvimento. Os parasitoides podem manipular a fisiologia e afetar o crescimento e desenvolvimento de seus hospedeiros, o que frequentemente resulta na morte de suas vítimas. Durante o parasitismo de Cotesia flavipes Cameron, 1891 (Hymenoptera: Braconidae) sobre Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae), teratócitos são liberados após eclosão da larva do parasitoide no interior do hospedeiro e esses teratócitos produzem um transcrito que codifica uma serpina (CfSerpina). As serpinas são inibidores de serino proteases muitas vezes associadas à regulação da cascata de ativação de profenoloxidases em fenoloxidases, enzimas relacionadas com a melanização de corpos estranhos no hospedeiro. O presente estudo foi conduzido para investigar a função biológica da CfSerpina e avaliar seu potencial biotecnológico como agente de controle de D. saccharalis após ingestão. A CfSerpina foi produzida em sistema heterólogo em células de E. coli BL 21, purificada em coluna de níquel-sepharose e quantificada pelo método de Bradford para posterior detecção por Western blot. A proteína foi produzida em quantidades suficientes para a realização da avaliação biológica e biotecnológica. Após os ensaios, verificou-se que a CfSerpina não pode ser associada à inibição da ativação da cascata de profenoloxidases na hemolinfa de D. saccharalis. Além disso, a exploração b... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Parasitoids are insects which use other insects to develop and complete their immature cycle. Parasitoids can manipulate the physiology and affect the growth and development of their hosts, which often results in the death of their victims. During parasitism of Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) by the parasitoid Cotesia flavipes Cameron, 1891 (Hymenoptera: Braconidae) teratocytes are released after the eclosion of parasitoid larvae inside the host and these teratocytes produce a transcript that encodes a putative serpin (CfSerpin). Serpins are serine proteases inhibitors often associated with the regulation of the activation of prophenoloxidases into phenoloxidases, enzymes responsible for melanization of foreign bodies in the host. The study was conducted to investigate the biological function of CfSerpin, as well to evaluate its biotechnological potential to disrupt the development of D. saccharalis larvae after ingestion. CfSerpin was produced in a heterologous system using E. coli BL 21 cells, purified on a nickel-sepharose column, quantified by the Bradford method, and detected by Western blot. Purified CfSerpin was produced in sufficient amount for biological and biotechnological evaluation. CfSerpin could not be associated with the inhibition of activation of prophenoloxidases cascade in the host insect hemolymph. In addition, biotechnological exploitation of CfSerpin as a toxic protein after ingestion did not resulted in the disruption of... (Complete abstract click electronic access below) / Doutor
30

Bioecologia comparada de duas linhagens de Telenomus remus Nixon (Hymenoptera: Platygastridae) parasitando ovos de Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

Naranjo Guevara, Natalia [UNESP] 14 February 2013 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:25:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-14Bitstream added on 2014-06-13T20:32:40Z : No. of bitstreams: 1 naranjoguevara_n_me_jabo.pdf: 1094961 bytes, checksum: abebabbc7d6d55795ac30c24a5d2bb13 (MD5) / A criação massal em condições de laboratório afeta a atividade e vigor dos parasitoides e,consequentemente, opotential como agentes de controle biológico. No Brasil, Telenomus remus foi introduzido em1986 e obtiveram-se altos níveis de parasitismo sobre Spodoptera frugiperda em testes de laboratório. Entretanto, estes níveis não foram obtidos em condições de campo.Assim, para ampliar abasegenéticadas linhagens e determinar possíveisdiferenças naatividade e vigor, opresente estudo objetivou: (1) realizara introdução deuma nova linhagem de T. remus no Brasil, a partir da Venezuela; (2) comparar a biologia das duas linhagens (uma coletada em culturas de milho e introduzida e outra,criadapor cerca de 600 gerações em laboratório) por meio da avaliaçãode parâmetros reprodutivos etabela de vida de fecundidade; (3) comparar as respostas funcionais; (4) avaliar a qualidade das linhagens utilizando-se a atividadede voo e a emergência como critérios. A espécie foi confirmada por taxonomista e foi confirmadaa sua especificidade porS. frugiperda. As duas linhagens demostraram similaridade genética em padrõesde restrição para asregiões 16S e ITS1, embora a linhagem importada apresentasse qualidadesuperior. Osparâmetros de fecundidadedemostraram que alinhagem introduzida temum potencial de aumento populacional maior e éintrinsecamente mais agressiva. As duas linhagens apresentaram resposta funcional tipo III, comestabilizaçãodo parasitismo apartirde 200 ovosdohospedeiro. Infere-se que a criaçãoem laboratório de T. remus requer cuidados que limitem a perda do potencial para controle biológico. Avaliaçõessubsequentes de qualidade bem como ametodologia atual de criação precisam ser revistas.O presente estudo resultou numimportante aporte para auxiliar na implementação de programas de controle biológico para a lagarta-do-cartucho. / Mass rearing in laboratory conditions affects the activity and vigor of parasitoids and consequentlytheir potentialas biological agents. In Brazil, Telenomus remus was introduced in 1986 and high levels of parasitism on Spodoptera frugiperda were obtained in laboratory tests. However, theselevels were notobtained infield conditions. Thus, tobroaden thegeneticbases of laboratorymaintained strains and to determine possible differencesin activity and vigor, this study aimed to:(1) introduce a new strain ofT. remus from Venezuela in Brazil;(2) compare the biology of two strains of T.remus (one collected in maizefields and introduced, and the other, maintained by over 600generations in laboratory conditions) by evaluatingreproductive parameters and fertilitylife tables, (3)compare the functional responses; (4) evaluate thequality ofthestrains using flightacitivity and emergence as criteria. The introduced species was confirmed by a taxonomist and their specificity for S. frugiperda was confirmed.Both strains demonstrated genetic similarity in restriction patterns for the 16S and ITS1 regions, although the imported strain showed superior quality as biological control agent. The fertility parameters showed thattheintroduced strain has a greater potentialfor population increaseand is inherently more aggressive. The two strains exhibited type IIIfunctional response, with stabilization of parasitism at 200 hosteggs. It is inferred that the laboratory rearingof T. remus requires efforts toprevent lossof biological control potential. Further evaluations of quality must be made and the currentmass rearing methodology should bere-designed. This study resulted in an important contribution that could aid the implementation of biological control programs for fall armyworm.

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