Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2004. / Vita. Bibliography: 154-160.

Thesis (M.S.)--Western Washington University, 2009. / Includes bibliographical references (leaves 46-52). Also issued online.

Thesis (M.Sc.)--York University, 2008. Graduate Programme in Higher Education. / Typescript. Includes bibliographical references. Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR51568

Thesis (Ph. D.)--Illinois State University, 2006. / Title from title page screen, viewed on May 14, 2007. Dissertation Committee: Steven A. Juliano (chair), Roger C. Anderson, L. Philip Lounibos, Wade A. Nichols, William L. Perry. Includes bibliographical references (leaves 145-162) and abstract. Also available in print.

Biological disturbance was found to be one of the most important mechanisms control1ing community organisation in the temperate sub-tidal region. The different types of biological disturbance structuring three encrusting communities were investigated on the east coast of Northland, New Zealand. The operation of each type was determined and the rate of disturbance measured. Experimental exclusion treatments were set up to demonstrate the effects of the major disturbance agents on community structure. The urchin Evechinus chloroticus was the most abundant agent of biological disturbance and affected the widest spectrum of encrusting organisms. The abundant balistid fish Navodon scaber was another major agent of biological disturbance in this region. Disturbance of algal populations also resulted from a guild of abundant herbivorous gastropods. Two episodes of fungal/bacterial infection degraded numbers of the large sponges Ancorina alata and Polymastia fusca. The operation of the different disturbance agents was found to be generally unpredictable in both time and space. There was no escape from biological disturbance for encrusting organisms in either small or large size. Re-occupation processes on patches of free primary space were investigated both experimentally and by using settlement plates (artificial free space patches). Recruitment was found to be irregular in space and time, especially for long-lived sessile organisms. Settlement processes as well as growth and mortality of newly settled organisms were investigated with a view to understanding community development. Only one verifiable example of substrate preparation or biological succession was found to operate in the communities studied. It is postulated that community organisation is flexible and not rigidly directed along a single successional pathway. Multiple developmental pathways and multiple stable configurations are possible in the same locality, resulting from the operation of different disturbance regimes.

Made available in DSpace on 2015-03-03T11:52:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-27Bitstream added on 2015-03-03T12:06:49Z : No. of bitstreams: 1 000807424_20161216.pdf: 2750566 bytes, checksum: 7abf8b6951850fddd07d259698cbd65f (MD5) Bitstreams deleted on 2016-12-16T09:54:40Z: 000807424_20161216.pdf,. Added 1 bitstream(s) on 2016-12-16T09:55:20Z : No. of bitstreams: 1 000807424.pdf: 4968033 bytes, checksum: e92dcddf8858995cc173cd998f274813 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Em ambientes aquáticos controlados por barragens, a elevada estabilidade hídrica favorece a proliferação de macrófitas, sendo para seu controle utilizado um manejo por alterações no nível da água. Porém não existem estudos que avaliem o efeito dessa técnica, que gera condições extremas de seca e inundação sobre a fauna de invertebrados fitófilos. O presente trabalho foi realizado durante alterações operacionais do nível da água para controle de macrófitas submersas no reservatório de Salto Grande (SP/PR). O objetivo foi avaliar o efeito dessas alterações sobre a diversidade de invertebrados associados à macrófita Egeria na lagoa Pedra Branca, conectada ao Rio Paranapanema e sob a influência do reservatório. As coletas foram realizadas ao longo de um transecto longitudinal da lagoa, antes do manejo ser iniciado (controle), no 1º, 7º e 11º dias após o rebaixamento (PR), quando a lagoa se desconecta do rio, e 49 dias após o enchimento do reservatório (PE). A hipótese do trabalho de menor diversidade após as alterações do nível da água do reservatório (seca e cheia induzidas) foi avaliada ao nível de toda a fauna e para os táxons de Chironomidae. As alterações do nível da água foram acompanhadas por alterações na estrutura da fauna fitófila, com variação temporal na densidade dos grupos, especialmente de Hexapoda, Mollusca e Protozoa. As mudanças ambientais relacionadas à contração (seca), e conseqüente concentração das macrófitas na área central da lagoa, e ampliação (cheia) das regiões limnética e litorânea geraram uma substituição de grupos dominantes (reduzindo a densidade de Chironomidae e aumentando a de Physa marmorata durante o PR), aumento na riqueza e maior diversidade e equitabilidade no PE. Os distúrbios causaram redução na densidade das três subfamílias de Chironomidae, principalmente de Chironominae, com maior riqueza e dominância em todas as datas ...

Ocean acidification (OA) together with other anthropogenic perturbations is projected to dramatically alter marine environments over the coming centuries. The vast majority of marine species reproduce by freely spawning sperm directly into the water column, where fertilisation can then either be external or a female can draw sperm into a burrow, brooding chamber or onto her external surface. Hence, sperm are now being released into rapidly changing seawater conditions. In this thesis, I firstly assess what is currently known on the potential for OA and other anthropogenic stressors to influence freely spawned sperm in marine invertebrate taxa. I then present a series of experimental chapters investigating the influence of OA, as a single stressor or in conjunction with a second stressor, copper, on sperm function, physiology and competitive fertilisation performance in a range of invertebrate taxa. My research demonstrates that sperm are vulnerable to the projected changes in seawater carbonate chemistry under OA, with responses observed at all biological levels from sperm physiology, swimming performance, fertilisation ecology and sperm competitiveness. In a multi-stressor experiment on polychaete gametes and larvae, I provide empirical evidence that changes to seawater pH under OA can alter the susceptibility of early life stages including sperm, to the common coastal pollutant copper. Sperm DNA damage increased by 150 % and larval survivorship was reduced by 44 % in combined exposures, than when exposed to copper alone. As a single stressor OA also acted to significantly reduce Arenicola marina sperm swimming speeds and fertilisation success. This work was followed up with a mechanistic investigation of A. marina sperm swimming performance under OA conditions. I found that the length of time between spawning and fertilisation can strongly influence the impact of OA on sperm performance. Key fitness-related aspects of sperm functioning declined after several hours under OA conditions, and these declines could not be explained by changes in sperm ATP content, oxygen consumption or viability. In a final set of experiments, I ran a set of paired competitive fertilisation trials in the sea urchin, Paracentrotus lividus. In addition to reducing fundamental sperm performance parameters, OA conditions affected competitive interactions between males during fertilisation, with potential implications for the proportion of offspring contributed by each male under the new conditions. This work suggests that the ‘best’ males currently may not be the most competitive under OA. Overall this body of work reveals a series of significant changes to sperm performance under OA that might act to perturb sperm functioning in future oceans.

Os ecossistemas de rios apresentam uma estrutura distinta, onde riachos menores deságuam em rios maiores formando uma rede fluvial dendrítica. Porém, poucos trabalhos realizados em ecossistemas lóticos consideram a estrutura dendrítica das bacias hidrográficas. A natureza dessas redes de riachos, com tributários e confluências, influencia a ocupação e a dispersão dos organismos aquáticos. Neste trabalho, estudei os efeitos da posição do tributário dentro da bacia hidrográfica e de confluências sobre a assembleia de insetos aquáticos. Quanto ao efeito da posição do tributário, testei a hipótese de que: i) a assembleia de insetos aquáticos em pequenos tributários que fluem para outro pequeno tributário (P –> P) diferem dos pequenos tributários que deságuam em grandes rios (P–>G) e ii) que a fauna de P–>P é um subconjunto aninhado da fauna do P–>G da mesma bacia hidrográfica. Em relação às confluências, independentemente da sua posição na bacia, hipotetizei que trechos antes da confluência terão fauna iii) distinta e iv) aninhada em relação aos trechos após a confluência. O trabalho foi realizado em nove microbacias em São José dos Ausentes (RS). Em cada uma foram obtidas amostras em dois tipos de riachos pequenos: aqueles que deságuam em rio de porte semelhante e aqueles que deságuam em rio maior e nas confluências em trechos antes e após. Indivíduos de Ephemeroptera, Plecoptera, Trichoptera e Elmidae (Coleoptera) foram coletados com amostrador Surber e identificados até o menor nível taxonômico possível. A riqueza de espécies rarefeita foi calculada e comparada a partir de teste t pareado unicaudal, onde cada microbacia constituiu um par. Análise de Variância Multivariada baseada em distância foi feita para avaliar se a composição e estrutura da fauna de insetos aquáticos diferem entre os tipos de riachos. Foram realizadas Análises de Coordenadas Principais para avaliar a distribuição das assembleias nos trechos coletados e Análise de Aninhamento usando a métrica NODF(Nestedness metric based on Overlapping and Decreasing Fill). Foram identificados 13.441 organismos, distribuídos em 65 gêneros e 121 morfoespécies. Os tributários que deságuam no rio maior apresentaram maior riqueza e composição distinta dos riachos que deságuam em rios de ordem menor. Além disto, riachos tributários nas regiões altas apresentaram uma fauna aninhada dentro dos tributários das regiões baixas. Quanto às confluências, apenas aquelas localizadas nas áreas altas das bacias hidrográficas tiveram efeito sobre a composição e estrutura da assembleia. Concluímos que a localização de tributários de pequena ordem na bacia hidrográfica é de fundamental importância para a determinação da riqueza e estrutura da fauna de insetos aquáticos. As assembleias de organismos aquáticos são moldadas pelas características dendríticas da rede de drenagem das bacias hidrográficas, onde a posição dos tributários e as confluências são elementos fundamentais para o entendimento de como funciona a organização e a distribuição das assembleias na paisagem. / Riverine ecosystems exhibit a distinct structure, where small streams flowing in to larger mainstem channel create a dendritic fluvial network. However, few studies have considered the dendritic structure of river basins. Regarding the nature of these streams networks, the spatial position of tributaries within catchments and the presence of confluences may influence occupation and dispersal of aquatic organisms. I studied the effect of tributary position at stream confluences on aquatic insect assemblage. Regarding the effect of tributary position in the catchment, we tested the hypotheses that i) aquatic insect assemblage at small tributaries that flow into another small tributary (hereafter S–>S) differ from small tributaries flowing into large mainstem river (hereafter S–>L) and ii) that fauna at S–>S is a nested subset of the fauna in S–>L of the same catchment. Regarding confluences, irrespective of its position in the catchment, we hypothesize that reaches upstream of confluences have a iii) distinct and iv) nested fauna in relation to downstream reaches. The study was conducted in nine watersheds in São José dos Ausentes e Bom Jesus (RS). In each watershed, samples were obtained in small streams that flow into a river of similar size and those that flow into mainstem river. Also I sampled reaches upstream and downstream confluences at lowlands and highlands. Individuals of Ephemeroptera, Plecoptera, Trichoptera and Elmidae (Coleoptera) were obtained with Surber sampler and identified to lowest possible taxonomic level. Rarefied species richness was calculated and compared using one-tailed paired t test, where each pair was a watershed. Multivariate Analysis of Variance based on distance was performed to assess if the composition and structure of the aquatic insect fauna differed between the streams types. I performed a Principal Coordinate Analysis to assess the distribution of the assemblages in the reaches. Finally, I evaluated nestedness of assemblages using the metric NODF (Nestedness metric based on Overlapping and Decreasing Fill). I identified 13,441 organisms distributed in 65 genera and 121 morphospecies. Tributaries that flow into the mainstem river supported greater richness and abundance than streams that flow into small streams. In addition, taxa from highland tributaries were a nested subset of the assemblage belonging to mainstem tributaries. About the confluences, only those located in highland areas affected reaches downstream in terms of assemblage composition and structure. I conclude that the location of small-order tributaries in the watershed is crucial for determining the structure and richness of the aquatic insect fauna. The assemblages of aquatic organisms are shaped by the characteristics of stream dendritic network, where the tributaries position and confluences are key to understanding how the assemblages organized and distributed in the landscape.

The thesis deals with scavenging on invertebrate cadavers. The goal was to estimate the dynamics of revelation and consumption of the cadavers by scavengers and to evaluate different effects influencing the dynamics in two agricultural habitats meadow and arable field.

Submitted by LÍVIA MARA ALVES FIGUEIREDO (livia.figueiredo@fosjc.unesp.br) on 2017-06-06T17:36:01Z No. of bitstreams: 1 Dissertacao mestrado final Livia.pdf: 1565199 bytes, checksum: f314f31c7fc2eba675f89a17f244abd2 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-06-06T17:49:25Z (GMT) No. of bitstreams: 1 figueiredo_lma_me_sjc.pdf: 1565199 bytes, checksum: f314f31c7fc2eba675f89a17f244abd2 (MD5) / Made available in DSpace on 2017-06-06T17:49:25Z (GMT). No. of bitstreams: 1 figueiredo_lma_me_sjc.pdf: 1565199 bytes, checksum: f314f31c7fc2eba675f89a17f244abd2 (MD5) Previous issue date: 2017-05-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A terapia fotodinâmica (TFD) tem demonstrado ação antimicrobiana sobre as leveduras do gênero Candida, sendo considerada uma técnica promissora para o tratamento de candidose. Recentemente foi relatado que a aplicação de TFD também pode resultar em ativação do sistema imunológico, contribuindo para a melhora da infecção. Assim, o objetivo desse estudo foi avaliar a ação da TFD e da terapia laser sobre a resposta imunológica à candidose experimental utilizando Galleria mellonella como modelo hospedeiro de infecção. Larvas de G. mellonella foram infectadas com diferentes cepas de Candida albicans e, após 30 min, foram tratadas com TFD mediada por azul de metileno e laser diodo emitido em 660 nm. A seguir, as larvas foram incubadas a 37°C por sete dias e analisadas diariamente para determinação da curva de sobrevivência. Para o estudo da resposta imunológica, após os tempos de 3, 6, 18 h da TFD foram realizados testes de determinação da densidade de hemócitos na hemolinfa de G. mellonella. Os dados obtidos na curva de sobrevivência foram avaliados pelo teste de Log-rank (Mantel Cox) e os resultados da análise imunológica por análise de variância ANOVA e teste de Tukey, com significância de 5%. Os resultados obtidos demonstraram que tanto para a cepa ATCC 18804 como para a cepa clínica 17 de C. albicans, a TFD prolongou a sobrevivência das larvas de G. mellonella infectadas por uma dose fúngica letal. Entretanto, houve diferença estatisticamente significante entre os grupos PDT e controle somente com cepa ATCC (p=0,0056). Foi verificado também que a infecção pela cepa ATCC 18804 de C. albicans em G. mellonella levou a uma redução no número de hemócitos na hemolinfa, e o tratamento com TFD e terapia laser conseguiram aumentar o número de hemócitos, mas sem apresentar diferença estatística significante. Foi possível concluir com esse estudo que a TFD bem como a terapia laser influenciaram de maneira positiva na melhora da infecção por C. albicans no modelo de G. mellonella. / Photodynamic therapy (PDT) has demonstrated antimicrobial activity on the yeast of the genus Candida and is considered a promising technique for the treatment of candidiasis. Recently it was reported that the application of PDT may also result in activation of the immune system, contributing to the improvement of the infection. The objective of this study is to evaluate the action of PDT and laser therapy on the immune response to experimental candidiasis using Galleria mellonella as host of the infection. G. mellonella larvae were infected with different Candida albicans strains and, after 30 min were treated with methylene blue-mediated PDT and laser diode emitted at 660 nm. Then, the larvae were incubated at 37° C for seven days and analyzed daily in order to determine the survival curve. For the study of the immunological response, after intervals of 3, 6, 18 h of the PDT, tests were performed to determine the density of hemocytes in the hemolymph of G. mellonella. The data obtained in the survival curve were evaluated by the Log-rank test (Mantel Cox) and the results of the immunological analysis by analysis of variance ANOVA and Tukey test, with significance of 5%. The results demonstrated that for both the ATCC 18804 strain and the C. albicans clinical strain 17, PDT prolonged the survival of the infected G. mellonella larvae by a lethal fungal dose. However, there was a statistically significant difference between the PDT and the control groups only with ATCC strain (p = 0.0056). It was also found that infection by the C. albicans ATCC 18804 strain in G. mellonella led to a reduction in the number of hemocytes in the hemolymph, and the treatment with PDT and laser therapy succeeded in increasing the number of hemocytes but without significant statistical difference . It was possible to conclude from this study that PDT as well as laser therapy positively influenced the improvement of C. albicans infection in the G. mellonella model.