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Dahl, Joakim Johnson Richard K. Sandin Leonard. "Detection of human-induced stress in streams : comparison of bioassessment approaches using macroinvertebrates /." Upsala : Swedish University of Agricultural Sciences, 2004. http://diss-epsilon.slu.se/archive/00000708/.
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Thesis (doctoral)--Swedish University of Agricultural Sciences, 2004.Thesis documentation sheet inserted. Appendix reproduces three papers and manuscripts co-authored with R.K. Johnson and two papers co-authored with R.K. Johnson and L. Sandin. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.
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Pryke, James Stephen. "Conservation of the invertebrate fauna on the Cape Peninsula." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1452.
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Askin, David. "Carotenoproteins in marine invertebrates." Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316509.
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Figueiredo, Lívia Mara Alves. "Efeitos da terapia fotodinâmica na candidose experimental e resposta imunológica no modelo hospedeiro de Galleria mellonella /." São José dos Campos, 2017. http://hdl.handle.net/11449/150842.
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Orientador: Juliana Campos JunqueiraBanca: Aguinaldo Silva Garcez Segundo
Banca: Antonio Olavo Cardoso Jorge
Resumo: 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 e... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: 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... (Complete abstract click electronic access below)
Mestre
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She, Shu-sheng. "Determinants of macroinvertebrate community structure on stone surfaces in Hong Kong streams /." [Hong Kong] : University of Hong Kong, 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1373149X.
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Sandler, Joel Stuart. "Anticancer compounds from marine invertebrates /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2005. http://wwwlib.umi.com/cr/ucsd/fullcit?p3247792.
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Sky, Alwin. "Saproxylic invertebrates in plantation forests." Thesis, University of Canterbury. Biological Sciences, 2011. http://hdl.handle.net/10092/9338.
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The conversion of natural forests to production land uses has led to huge losses of biodiversity and continues to threaten remaining terrestrial flora and fauna throughout the world. The global demand for wood products and energy, which was partly responsible for the loss of primary native habitat, is now one of the leading drivers of afforestation with significant new areas of plantation replacing former agricultural lands. While plantations do not support the same biodiversity values as natural forests they do provide significant habitat for a range of species. Saproxylic invertebrates (species that are dependent on deadwood) are strongly affected by the temporal and spatial availability of different deadwood resources. Previous research on saproxylic invertebrates has largely been restricted to natural or managed natural forests predominantly in the Northern Hemisphere, where forest management practices have been modified to conserve these species This thesis fills a distinct research gap in New Zealand and is the first large scale study to quantify the effects of deadwood age, wood species, and landscape composition on saproxylic invertebrates in our plantation forests by direct rearing. In this thesis I show that thinning residues, which are currently retained in many plantation forests, provide significant habitat for a range of native invertebrate taxonomic groups, including diverse assemblages of Coleoptera and Hymenoptera. Deadwood age is an important attribute determining taxonomic richness of saproxylic invertebrates. Richness of invertebrate orders/classes and Coleoptera species all increased in older deadwood material, and a stepwise multidimensional analysis procedure indicated that the age of deadwood was the most important factor structuring saproxylic invertebrate community composition in Pinus radiata thinning residues. Deadwood age was a stronger predictor of community composition in thinning residue than measures of landscape composition, such as the proportion of remnant native forest cover. The change in saproxylic invertebrate composition that occurs with deadwood age was related to changes in the feeding guilds, with a transition from primary wood feeding species to predators/parasitoids and fungal feeders with increasing dead wood age. Because thinning’s are carried out at prescribed times throughout the stand rotation, stand age could be adopted as a proxy for deadwood age in these systems allowing forest managers a simple method for monitoring saproxylic beetle habitat availability . My research provides strong empirical evidence that supports the existing conservation paradigm that forest managers should seek to create a mosaic of habitats at the landscape scale to enhance biodiversity opportunities in plantations.
In addition to the habitat opportunities provided by P. radiata deadwood that is derived from silvicultural practices there are several sources of native wood in plantations. Native woody resources are found in either the embedded remnant areas of native forest or in the understory of stands as many native woody species colonise this habitat. As yet the importance of native understory deadwood resources for saproxylic species is unknown. In addition it is unclear how the importance of such understory resources is influenced by proximity to remnant native forest patches. I used experimental wood billets of four tree species (3 native and the exotic P. radiata) placed along replicated transects spanning native habitat and adjacent early stage regenerating plantation stands to assess the saproxylic invertebrate assemblages associated with different deadwood species as a function of proximity to native forest. I found that an interaction between wood host specificity (local scale) and proximity to interior native forest (landscape scale) was the most important factor regulating saproxylic invertebrate community structure. Deadwood of the native subcanopy trees Schefflera digitata, Melicytus ramiflorus, Aristotelia serrata and the exotic conifer P. radiata provided habitat for different subsets of the saproxylic fauna. The most pronounced differences in saproxylic community structure were between the native sub-canopy broadleaf species and the exotic P. radiata. Surprisingly the P. radiata supported a greater species richness and abundance of saproxylic Coleoptera in native remnants than the native wood species in the same habitat. In general, species richness was higher in native forest habitats and declined with increasing distance from native habitat. These results suggest that both the diversity of deadwood resources that are available and their proximity to native remnants are important for maintaining saproxylic communities in plantations. However, two of the native wood species (M. ramiflorus and A. serrata) exhibited steep declines in species richness at the plantation native forest boundary, suggesting that the contrasting stand types (native remnant and young regenerating plantation stands) with their different microclimate may have had a significant influence. Future research needs to compare the saproxylic fauna of dead wood in mature plantation stands with adjacent native remnants to ascertain if the effect of native habitat proximity is due to landscape composition or a reflection of microclimatic differences.
The large diversity of saproxylic species observed during this study highlights the importance of plantations as habitat for saproxylic species, particularly in heavily fragmented landscapes that retain little original native forest. My research findings provide forest managers with options for improving forest management to enhance opportunities for the conservation of saproxylic invertebrates. In addition my thesis provides one of the most comprehensive multi-taxon data sets of saproxylic species associated with a variety of deadwood resources. This information will be invaluable to future researchers that continue to work on New Zealand’s saproxylic fauna.
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Reese, David Stephen. "Marine invertebrates and Mediterranean archaeology." Thesis, University of Cambridge, 1988. https://www.repository.cam.ac.uk/handle/1810/272352.
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Bat, Levent. "Pollution effects on marine invertebrates." Thesis, University of Aberdeen, 1996. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU083075.
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In this study, the amphipod Corophium volutator and the polychaete Arenicola marina were evaluated as test organisms for use in sediment toxicity tests by adapting standard protocols developed by the EPA/COE and Thain et al. (1994) respectively for conducting 10-day sediment toxicity tests. Although these species have been used to assess the toxicity of marine and estuarine sediments, the detailed ecotoxicologies of these animals are not well documented. In particular, the effects of specific contaminants of known concentrations on this bioassay are not known. Here, I report several experiments carried out using clean intertidal sediment contaminated with the heavy metals copper, zinc and cadmium, and employing the Corophium and the Arenicola bioassay protocol. Concentrations of copper, zinc and cadmium were determined in tissues of Corophium exposed for 4 and 10 days to contaminated sediment using four protocols to allow for any material present in the gut. Significant differences in metal concentrations occurred between the protocols where gut contents were removed and those where they were left intact. These findings have implications for the way in which analyses of metal burdens are carried out for invertebrates in ecotoxicological work. Corophium survival in seawater with dissolved copper, zinc and cadmium was higher in the presence of sediment than without sediment, although the concentrations of these metals in Corophium tissues were the same in both cases. Bioconcentration factors (BCF) were inversely related to seawater concentrations of copper, zinc and cadium, with the lowest exposure concentration, (0.1 mg l-1 for both copper and zinc, 0.01 mg l-1 cadmium) having the highest BCF. Both live amphipods and those that had died accumulated copper, zinc and cadmium in their bodies during the bioassay, and bioconcentration factors were always higher for dead than for living amphipods for each metal.
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Sumner-Rooney, Lauren Héloïse. "Sensory systems in marine invertebrates." Thesis, Queen's University Belfast, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709845.
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Sensory systems form the first point of contact between animals and their surroundings. The study of sensory systems is both a rich and diverse anatomical and behavioural field, and a potentially invaluable tool in evolutionary biology. This thesis examines four systems in three molluscan classes and ophiuroid echinoderms, addressing novel or poorly-understood systems and examining evolutionary trends by assessing the anatomy of more familiar structures in a phylogenetic context. The primary study system is a novel discovery reported herein throughout the chiton order Lepidopleurida, named the Schwabe organ. By combining detailed anatomical study, electrophysiology and behavioural experiments, 1 demonstrated that the Schwabe organ mediates light-avoidance behaviour and likely shares developmental origins with the chiton larval eye. A similar integrative approach was applied to a putative ‘visual* system in the ophiuroid Ophiocoma wendtii. Anatomical and behavioural results indicated that animals may use an extensive network of dermal photoreceptors for image formation, however this system differs substantially from the established model. The two final chapters focus on sensory and nervous systems in evolution. A re-description of scaphopod neuroanatomy in Rhabdus rectius demonstrates the potential power of a neurocladistic approach in solving deep phylogenetic questions, highlighting important similarities with cephalopod neural architecture and prompting the re-assignment of the major body axes in adult scaphopods. Finally, a study of eye reduction and eye loss in deep sea solariellid gastropods found surprising morphological diversity and differential progression between independent eye reductions, even within genera. This thesis makes several important contributions to our knowledge of four sensory systems and their evolution across two major invertebrate phyla: the Schwabe organ, extra-ocular photoreception in 0. wendtii, the Steiner organ and gastropod eyes. Overall, it also demonstrates the powerful nature of cross-disciplinary projects as well as the versatile role of sensory biology in broader evolutionary studies.
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Sohn, Dosung. "Invertebrates analysis by capillary electrophoresis." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0024340.
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Graiff, Kaitlin W. "The abundance and distribution of megafaunal marine invertebrates in relation to fishing intensity off central California." Pullman, Wash. : Washington State University, 2008. http://www.dissertations.wsu.edu/Thesis/Fall2008/K_Graiff_111808.pdf.
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Thesis (M.S. in environmental science)--Washington State University, December 2008.Title from PDF title page (viewed on Mar. 4, 2009). "School of Earth and Environmental Science." Includes bibliographical references (p. 24-27).
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Chan, King-tung. "Multivariate analysis of benthic macroinvertebrate communities of Hong Kong streams /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18037045.
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Morrison, Joan Olivia. "Cretaceous marine invertebrates: A geochemical perspective." Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7784.
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A diagenetic evaluation was performed on marine fossil shell material from Cretaceous sediments of North America, the Arctic, the Antarctic and several localities in Europe. Trace element chemistry, XRD, SEM and stable isotope geochemistry were consistent in their results. Preservation of the original shell material of the low-Mg calcite organisms, brachiopods and belemnites, and the numerous aragonitic organisms was slightly variable with the majority of samples well preserved. Those samples that were altered underwent diagenetic stabilization in both reducing and oxic environments. Using the chemical data from only well preserved fossil shell material, basin paleo-reconstructions showed that from Aptian to Maastrichtian time, the Cretaceous seas were generally aerobic with some dysaerobia evident at the sediment/water interface and in the shallow sediment column. Paleosalinities fluctuated from brackish to normal marine, especially in the Western Interior Seaway of North America and the Paris Basin. The Lower Saxony basin, the Arctic and Antarctic were mainly normal marine with brackish conditions developing on occasion. Paleotemperatures determined from $\partial\sp $O data of preserved aragonite and low-Mg calcite shell material, also showed some variance. The Arctic and Antarctic were coolest, with Campanian/Maastrichtian temperatures about 12 or 13$\sp\circ$C, whereas the Lower Saxony basin and the Western Interior Seaway were slightly warmer, ranging from 11 to 20$\sp\circ$C. The Barremian/Aptian appeared to be the warmest time and a cooling trend was fairly consistent from then on.
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Voparil, Ian M. "Lipid Solubilization by Marine Benthic Invertebrates." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/VoparilIM2003.pdf.
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Hayward, Eva. "Envisioning invertebrates and other aquatic encounters /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2007. http://uclibs.org/PID/11984.
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Nisbet, Katherine. "Exploring connectivity of marine benthic invertebrates." Thesis, University of Liverpool, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.569247.
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With the marine environment subjected to ever increasing anthropogenic pressures resulting in biodiversity and habitat losses, there is an urgent need to implement effective management and conservation strategies to limit these losses. One such strategy is the designation of Marine Protected Area (MPA) networks, with the central concept that individual MPAs are connected to its neighbours within the network However, determining scales of connectivity in an environment that varies considerably both spatially and temporally is inherently difficult. Larval dispersal is a main driver of population connectivity, and planktonic larval duration (PLD) is frequently used to infer dispersal distance. Thus far studies have predominantly focused on fish and tropical species, using approaches such as larval dispersal modelling, otolith microchemistry or genetic estimates of connectivity. This thesis aimed to assess the levels of connectivity in a range of benthic invertebrates characteristic of offshore shelf seas of the Northeast Atlantic, at a range of spatial and temporal scales. This was achieved by: (1) examining the variation in PLDs of a typical benthic assemblage, then using this information to examine the variation in realised dispersal at multiple locations using particle tracking software; (2) assessing habitat preferences for the same species, and exploring how the distribution of broad habitats would affect connectivity of species; and (3) using microsatellite markers to determine the genetic structure of the exploited scallop Pecten maximus at both a localised scale (Isle of Man) and a regional scale covering over half its range. While biological variation, in the form of PLD, did affect dispersal potential of common benthic invertebrates, it was the physical factors of hydrographic regime and substrate type within a species given dispersal range that played the most important role in determining ultimate dispersal distance and location. Additionally, the scale of genetic structure of the scallop Pecten maximus, with Norway genetically distinct from Scotland, Ireland and Isle of Man but weaker or no structure within those regions, highlighted the interaction of biological and physical factors. Ultimately, this thesis has provided valuable insight into the drivers of connectivity in the marine benthos, but further work, particularly more collaborative studies across multiple fields, is required if MPAs are to achieve their aims in the face of a changing environment.
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Cahir, Marie. "Neurotensin and related peptides in invertebrates." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241330.
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Grange, Laura Joanne. "Reproductive success in Antarctic marine invertebrates." Thesis, University of Southampton, 2005. https://eprints.soton.ac.uk/41355/.
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The nearshore Antarctic marine environment is unique, characterised by low but constant temperatures that contrast with an intense peak in productivity. As a result of this stenothermal environment, energy input has a profound ecological effect. These conditions have developed over several millions of years and have resulted in an animal physiology that is highly stenothermal and sometimes closely coupled with the seasonal food supply, e.g. reproductive periodicity and food storage. Therefore, Antarctic marine animals are likely to be amongst the most vulnerable species worldwide to environmental modifications and can be regarded as highly sensitive barometers for change. Reproductive success is a vital characteristic in species survival and evaluation of change in reproductive condition with time key to identifying vulnerable taxa. Characterising reproductive success with time is a major requirement in predicting species response to change and the early stages of species loss. Some invertebrates are highly abundant in shallow water sites around the Antarctic and form conspicuous members of the Antarctic benthos. Three common echinoderms and one nemertean were sampled from sites adjacent to the British Antarctic Survey’s Rothera Research Station, Adelaide Island, on the West Antarctic Peninsula between 1997-2001. Reproductive patterns were determined by histological analyses of gonad tissue. This study provided further evidence for inter-annual variation in Antarctic gametogenic development, which appeared to be driven to some extent by trophic position and reliance on the seasonal phytoplankton bloom. The largest variation in reproductive condition was demonstrated for the detritivorous brittle star, Ophionotus victoriae. The seasonal tempos of this echinoderm have been attributed in part, to the seasonal sedimentation events common in the high Antarctic. The reproductive patterns in the scavenging starfish, Odontaster validus and the predatory nemertean, Parborlasia corrugatus showed less inter-annual variation. The de-coupling of these invertebrates from the intensely seasonal phytoplankton bloom appeared to partially account for the reproductive trends observed. The lack of inter-annual variation in the reproduction of the filter-feeding sea-cucumber, Heterocucumis steineni, was somewhat counterintuitive, although problems with sample processing probably accounted for the majority of this anomaly. Echinoderms were also collected during the Antarctic summer field seasons in 2003 and 2004. A series of fertilisation success studies were undertaken comparing the adaptations in an Antarctic and an equivalent temperate starfish to achieve optimal numbers of fertilised eggs, and elemental analyses were used to estimate the nutritional and energetic condition of the bodily and reproductive tissues in two Antarctic echinoderms. Fertilisation studies indicated that Antarctic invertebrates require 1-2 orders of magnitude more sperm to ensure optimal fertilisation success. These sperm tended to be long-lived and capable of fertilising eggs 24+ hours after release. The study suggested that synchronous spawning, aggregations and specific pre-spawning behaviour are employed to help counter the deleterious effects of sperm limitation. The Antarctic eggs and sperm were also highly sensitive to even small modifications in temperature and salinity, affecting the number of eggs fertilised. Such stenothermy is of particular relevance if the 1-2ºC rise in global temperature, predicted over the next century, is realised. Biochemical composition of body components of two species of Antarctic echinoderm indicated a significant difference in the composition between the male and female gonad, particularly in the Antarctic brittle star Ophionotus victoriae. The ovaries contained a much larger proportion of lipid compared to the testes, and demonstrated a distinct seasonality in composition. Higher levels of lipid were observed in the ovary during the austral winter coincident with a period of reproductive investment and maturing oocytes in the gonad. O. victoriae exhibited lower amounts of lipid in the late austral spring suggesting the removal of mature oocytes from the ovary through spawning. The seasonality in composition and the high levels of lipid and protein measured in the ophiuroid gut tissue, suggested the gut might play a role in providing material and energy for metabolic function and possibly gametogenesis; higher lipid levels were apparent during the period of seasonal phytodetrital flux. The role of the pyloric ceaca in asteroids as a nutrient storage organ was also evident in the high levels of both protein and lipid observed in this bodily component in the star fish, Odontaster validus.
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Andrade, Maria Helena da Silva. "O fenômeno da \"decoada\" no Pantanal do rio Paraguai, Corumbá/MS: alterações dos parâmetros limnológicos e efeitos sobre os macroinvertebrados bentônicos." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-19092011-142519/.
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Este trabalho teve como objetivo investigar a hipótese de que a decoada (alteração dos parâmetros físicos e químicos da água) é um fenômeno natural importante na estruturação da comunidade de invertebrados bentônicos do Pantanal do rio Paraguai, bem como a caracterizar a comunidade de macroinvertebrados bentônicos quanto à composição, abundância de organismos e riqueza em função das alterações ambientais provocadas pela decoada. Além disso, pretendeu-se contribuir para o conhecimento da biota do pantanal de Mato Grosso do Sul com o intuito de subsidiar ações de prevenção e/ou mitigação de possíveis impactos ambientais. Os ambientes escolhidos foram dois corpos de água adjacentes ao rio Paraguai, sendo um com características lênticas (Baía Tuiuiú) e outro, semi-lóticas (Bracinho), Corumbá/MS, ambos sob o efeito do pulso de inundação. O capítulo um realizou uma caracterização limnológica dos dois corpos de água ao longo de um ciclo hidrológico, enfatizando as alterações provocadas pela decoada, por ocasião da subida das águas. O capítulo 2 objetivou estudar a composição e a distribuição da fauna de Chironomidae relacionando-as com as alterações limnológicas ao longo de um ciclo hidrológico (abril/2008 a fevereiro/2009), enfatizando a influência da decoada. O capítulo 3 pretendeu conhecer a composição de Oligochaeta, considerando as relações com fatores abióticos, no intuito de contribuir para o entendimento do fenômeno da decoada bem como subsidiar posteriores trabalhos e ações relacionados à gestão da planície pantaneira, objetivando sua manutenção e conservação. A decoada é um evento que potencializa a desestruturação do ambiente, agindo significativamente sobre as populações de invertebrados bentônicos. O fato de não ter sido encontrado nenhum organismo vivo durante a ocorrência do fenômeno destaca a sua importância enquanto fator ecológico essencial na dinâmica das populações biológicas dos ecossistemas pantaneiros.This study aimed to investigate the hypothesis that the decoada(change in physical and chemical parameters of water) is an important natural phenomenon in the community structure of benthic invertebrates in the Pantanal of the Paraguay River, and to characterize the benthic macroinvertebrate community regarding the composition, richness and abundance of organisms as a function of environmental changes caused by the \'decoada\'. In addition, soughted to contribute to the knowledge of the biota of wetland of Mato Grosso do Sul in order to support programs to prevent and / or mitigate potential environmental impacts. The areas chosen were two bodies of water adjacent to the Paraguay River, one with lentic feature (Tuiuiú Bay) and another, semi-lotic (\'Bracinho\'), Corumbá / MS, both of them suffering the effect of pulse flood. The chapter 1 conducted a limnological characterization of the two water bodies along a hydrological cycle, emphasizing the changes caused by the \'decoada\', when the water level rises. Chapter 2 aimed to study the composition and distribution of Chironomidae fauna relating them to limnologicals changes over a hydrological cycle (the april/2008 to february/2009), emphasizing the influence of the decoada. Chapter 3 intended know the composition of Oligochaeta, considering the relationships with environmental factors in order to contribute to the understanding of the phenomenon of \'decoada\' and support further work and actions related to the management of the Pantanal, aiming to maintain the ecosystem and related services. The decoada is an event that enhances the disintegration of the environment, acting significantly on populations of benthic invertebrates. The fact that no organism had been found alive during the occurrence of the phenomenon underscores its importance as an essential ecological factor in the dynamics of biological populations of wetland ecosystems.
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Miao, Shichang. "Novel secondary metabolites from selected marine invertebrates." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/31133.
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Chemical studies of a Northeastern Pacific tunicate and three Papua New Guinea sponges have led to the isolation of sixteen new secondary metabolites. The structures of the new compounds were determined by spectroscopic analysis and chemical interconversions. The absolute stereochemistry of imbricatine, a previously reported starfish metabolite, has also been determined.
The northeastern Pacific tunicate Ritterella rubra has been found to contain a novel series of aromatic butenolides, rubrolides A-H (149-156). The structures of the rubrolides were solved by the analysis of NMR (¹H, ¹³C, COSY, nOe, HETCOR, FLOCK, HMQC and HMBC), MS and IR data combined with chemical interconversions. FLOCK, a new ¹H/¹³C long-range correlation experiment, played a key role in establishing the rubrolide carbon skeleton. The rubrolides represent the largest family of non-nitrogenous tunicate metabolites. The protein phosphatase inhibitory activity and the potent antibiotic activities of the rubrolides warrant further investigation.
The absolute stereochemistry of imbricatine (179), a compound reported from the starfish Dermasterias imbricata, has been determined by comparing the optical properties of its chemical degradation products with those of model compounds. Raney nickel reduction of 179 yielded benzyltetrahydroisoquinoline 188a which was methylated to give 188b. Comparison between the CD spectrum of 188b and those of model compounds 189 and 190 solved the absolute stereochemistry of the tetrahydroisoquinoline fragment of 179. Reductive hydrolysis of 179 followed by oxidation yielded histidine disulphide 182. Comparison of the optical rotation of 182 with the reported value solved the absolute stereochemistry of the histidine fragment of 179. Attempts to study the biogenesis of 179 were unsuccessful.
Examination of three Papua New Guinea sponges resulted in the isolation of eight new compounds. Six new bastadins (211-216) were isolated from Ianthella basta. The structures were elucidated by spectroscopic analysis as well as comparison with the previously reported bastadins. A Xestospongia species was found to contain xestospongin E (238), a new metabolite, and a number of known xestospongins. Both the bastadins and the xestospongins possess antibiotic and cytotoxic activities. A symmetrical enyne, callydiyne (247), was isolated from Callyspongia flammea. The structure of 247 was determined by spectroscopic studies.Science, Faculty of
Chemistry, Department of
Graduate
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Chouinard, Julie. "Metal concentrations in benthic invertebrates in peatlands." Thesis, University of Ottawa (Canada), 1993. http://hdl.handle.net/10393/6549.
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In order to assess the influence of various abiotic and biotic factors on metal accumulation in peatlands, insects were collected from bogs, mineral poor fens and circumneutral fens located in Central Ontario. The peatlands represented a gradient in alkalinity from 0 (acid bogs) to 200 $\mu$eq$\cdot$L$\sp{-1}$ (circumneutral fens). Further, the peatlands had important hydrological differences with no obvious inflows in the bogs and inflow/outflow streams in the fens. Given these contrasting environments, it was hypothesized that there would also be differences in metal accumulation in the associated biota. The results of this study indicate that the acidification of peatlands, whether natural or anthropogenic, will not lead to greater availability of metals such as Zn, Cu, Al, and Mn. High organic matter levels may serve to mitigate the effects of acidification on metal availability in such peatlands. (Abstract shortened by UMI.)
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Haas, Elske Maria de. "Persistence of benthic invertebrates in polluted sediments." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2004. http://dare.uva.nl/document/75485.
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Bender, Cheryl E. "The mitochondrial pathway of apoptosis in invertebrates." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC IP addresses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3288845.
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Thesis (Ph. D.)--University of California, San Diego, 2007.Title from first page of PDF file (viewed June 2, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 190-218).
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Özden, Özge. "The biodiversity of invertebrates in Cyprus ecosystems." Thesis, University of Exeter, 2009. http://hdl.handle.net/10036/67893.
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There has been great concern within the scientific community about biodiversity loss and the extinction crisis worldwide. In order to set priority targets for biodiversity conservation in any region of the world, it is necessary to have good, long term, scientific, biological data. Without detailed information on local floras and faunas, it is impossible to prepare detailed management plans for biodiversity conservation within the area. The conservation importance of an area, which can be determined by assessing its biodiversity, by considering its species richness and abundance of key species (indicator groups). Therefore, during this thesis we attempted to clarify processes that influence the invertebrate fauna of Cyprus in different ecosystems. We also sought to investigate the population dynamics, abundance, species richness and the diversity of different invertebrate groups. We not only described the local invertebrate fauna, but also analysed impacts of different management regimes on them. In addition to this, we used different group of invertebrates as indicators in order to identify the biologically valuable habitats for biodiversity conservation in Cyprus. Firstly, field surveys were carried out over a two year period for the determination of thrips fauna (Thysanoptera) in the northern part of Cyprus. During the surveys 2029 specimens were collected. We recorded 43 thrips species belonging to 23 genera. Five genera and 14 species were new records for the island of Cyprus. Also we studied the population of the thrips pests and resulting damage to fruits on different nectarine varieties in north Cyprus during 2004 and 2005. We found 21 different thrips species, most of them encountered during the petal-fall period of nectarine trees. The “Maravilla” variety (early nectarine variety) had the highest rate of non-marketable fruit during 2004-2005. Secondly, we determined the impacts of different management regimes on invertebrate fauna and diversity in Cypriot olive groves. We selected high and low altitude olive groves with no management, tillage only, or tillage – pesticide – fertilizer application. During this study, 12,387 arthropods were recorded and identified from 18 different orders or higher taxa. Our results showed that pesticide application on olive tree canopies significantly reduces the abundance and diversity of arthropods. We also determined the impacts of management regimes on woodlouse fauna. We found significant reductions in woodlouse abundance with tillage combined with pesticide and fertilizer application. Thirdly, we used butterflies as an indicator group to identify the importance of forest and garrigue habitats for biodiversity conservation in Cyprus. Transect counts were used to assess the abundance and diversity of butterflies in old and young forests. We observed a significant effect of forest type on the abundance of butterflies. The number of butterflies and the number of endemic species was also higher in old forests than young forests. Also we used butterflies to evaluate the conservation value of grassland and shrubland mosaics within garrigue ecosystems in Cyprus. Habitat type showed a highly significant effect on butterfly abundance, this was particularly the case with endemics. Greater abundance was observed during early and the late season in grassland habitats. The results underline the potential conservation significance of agricultural ecosystems and should serve to promote ecologically sustainable agricultural production systems in Cyprus. Also as a result of this thesis, identification and protection of grassland-shrubland mosaics in garrigue ecosystems and old mature forests along Kyrenia Range Mountains should be considered priorities in future conservation programmes.
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Hayward, Scott Alexander Lee. "The functional ecology of polar terrestrial invertebrates." Thesis, University of Birmingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396115.
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Morrisey, D. J. "Competitive avoidance in marine deposit feeding invertebrates." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332468.
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Williams, Mark Elliott. "Fertilization ecology of broadcast spawning marine invertebrates." Thesis, University of St Andrews, 1999. http://hdl.handle.net/10023/14544.
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In situ measurements of the fertilization success of broadcast spawning marine invertebrates have been conducted mainly on shallow subtidal echinoderm and coral species. In this study, field fertilization success was measured for two infaunal, intertidal polychaetes Arenicola marina and Nereis virens. Both species are epidemic spawners, with populations of A. marina spawning over a few days in autumn while N. virens spawns in early spring. The fertilization success of female Arenicola marina is highly variable, ranging from 0 to 100%, and is determined by male spawning density. It is hypothesised that fertilization success over the entire spawning period is the result of an accumulation of fertilizations each day in the spawning period. Fertilization success was measured indirectly in Nereis virens by transplanting oocytes into the field. At least two spawning periods occurred for the population studied here. Fertilization success was uniformly high during the first period, and in the second fertilization success was highest among those eggs located high in the water column as opposed to those at substratum level. The fertilization strategies of these polychaetes are discussed in the light of these results. Comparative laboratory experiments were performed on factors that affect fertilization success in Arenicola marina. Nereis virens, Asterias rubens and Echinus esculentus, including sperm:egg ratio, sperm-egg contact time and sperm concentration. The extent to which each of these factors affects fertilization success varies with species, and this is explained by gamete attributes and mathematical models. Gamete longevity significantly affects fertilization success, and eggs and sperm of Arenicola marina are extraordinarily long lived compared to those of the other species studied here and elsewhere. Eggs are viable for 5 days after spawning, while dilute sperm remains capable of fertilizing eggs for more than 48 hours. The laboratory data are discussed in terms of the fertilization strategies of each of the species.
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Safronova, D. "Sewage water biomonitoring using invertebrates as bioindicators." Thesis, Видавництво СумДУ, 2004. http://essuir.sumdu.edu.ua/handle/123456789/23265.
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Scott, Robyn. "Biogeographical patterns of southern African marine invertebrates." Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/6187.
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Includes abstract.Includes bibliographical references (p. 156-171).
Biogeography is defined as the study of life, in a spatial and temporal context, with respect to the analysis and explanation of patterns for a given area. The tendency for species richness and diversity to increases towards the equator, where both peak, is a much debated and tested pattern. Underlying mechanisms thought to cause this pattern are: gradients in temperature, stress, productivity, competition, predation, stability, effective evolutionary time, niche breadth, range size and area of occupancy. Evidence exists that both supports and negates most of these mechanisms. In addition to the richness gradient, a latitudinal gradient in geographical range size exists, whereby species range sizes decrease with latitude, referred to as Rapoport's Rule. This has been linked to species ability to tolerate changes in climate. The latitudinal gradient in species richness is thought to be a by-product of Rapoport's Rule and the "Rescue Effect".
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Flowers, Andrew E. "Metal-binding proteins in tropical marine invertebrates." Thesis, Queensland University of Technology, 1995.
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Uys, Charmaine Janet. "The impact of pine plantations and alien invertebrates on native forest and fynbos invertebrate communities in Table Mountain National Park." Doctoral thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/6888.
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While the Cape Peninsula (South Africa) is renowned for its exceptional plant and invertebrate diversity and endemism, extensive alien plant invasions and exotic pine plantations threaten and reduce native species richness. This study frames invasion ecology theory in a conservation context, and examines the impact of planting and felling pine on litter invertebrate communities, by comparing invertebrate diversity between pine plantations and native vegetation. Impacts of the worst invasive alien invertebrate (Argentine ant, Linepithema humile) and other alien invertebrate species are investigated. This is one of the first attempts to inventory and quantify impacts of non-ant alien invertebrates in Table Mountain National Park. The entire ground-dwelling invertebrate community was sampled at 31 sites in summer 2008/2009, using soil cores, leaf litter samples, pitfall traps, sugar-baited ant traps and decayed logs. A total of 112 404 individuals, representing 728 species (10 classes and 38 orders), including nine Cape Peninsula endemic and 19 alien species, was collected. Pine plantations supported lower species richness and abundance, and different community assemblages, compared to Afrotemperate forest, but similar species richness to fynbos. This supports previous local studies and global trends. Pine plantations shared fewer species with fynbos than forest, and negatively affect fynbos-specialist invertebrates, because afforestation reduced available fynbos habitat. Alien species richness was similar across habitats. Argentine ants, like most other alien species identified, were present in all habitats. The impact of Argentine ant invasion on native ant communities was evaluated using species richness and community composition analyses, species co-occurrence patterns (C-score), and the functional group approach. The comparative approach adopted provided no evidence for displacement, impoverishment, or community disassembly. No clear impacts of the 18 non-ant alien species on the abundance, species richness, or community composition of corresponding native taxa were detected. Disturbance history offers a more parsimonious explanation for the trends observed, particularly in fynbos. However, carnivorous molluscs require careful monitoring, given their abundance and known impacts elsewhere. Using a reiterative process and IndVal, two ant species (Pheidole capensis and Camponotus bertolinii) were selected as ecological indicators of restoration progress in fynbos following clear-felling of pine. Ants similarly have application for monitoring in other Mediterranean-type ecosystems impacted by invasive pines.
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Orav-Kotta, Helen. "Habitat choice and feeding activity of benthic suspension feeders and mesograzers in the northern Baltic Sea /." Tartu, Estonia : Tartu University Press, 2004. http://dspace.utlib.ee/dspace/bitstream/10062/489/5/Kotta.pdf.
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Peterson, Eric W. "Fate and transport of 17 [beta]-Estradiol in karst aquifers /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3060131.
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Morris, Sandra Anne. "Novel secondary metabolites isolated from selected marine invertebrates." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/31073.
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A study of the secondary metabolism of two northeastern Pacific sponges and two Sri Lankan nudibranchs has led to the isolation of thirteen new and one previously known natural products. The structures of all of the compounds were determined by a combination of spectroscopic data analysis and chemical interconversions.
A study of the chemistry of the northeastern Pacific sponge Hexadella sp. has resulted in the isolation of six new brominated alkaloids. Two of these, hexadellins A (77) and B (78), are derived from dibromotyrosine. The structures of compounds 77 and 78 were determined via their acetylated derivatives 79 and 80. Four compounds possessing novel bis(indole) structures have also been isolated. Topsentin B2 (74) was isolated as a mixture of two slowly interconverting tautomers, 74a and 74b. Methylation of 74 resulted in the production of trimethyltopsentin B2 (75); the structure of 75 was determined spectroscopically. The structures of dragmacidons A (81), B (82), and C (83) were determined by a combination of spectral data interpretation and chemical interconversions. Dragmacidon C (83) was originally incorrectly assigned as 88; the correct structure was determined based upon synthesis of the model compound 94. Compounds 77 and 78 possess antimicrobial activities. Compounds 74 and 81 show considerable cytotoxic and antineoplastic activities.
Five new triterpene glycosides have been isolated from the northeastern Pacific sponge Xestospongia vanilla. The structures of isoxestovanin A (125), xestovanin C (127), dehydroxestovanin A (129), epi-dehydroxestovanin A (131), and dehydroxestovanin C (132) were all determined by a combination of spectral data interpretation and chemical interconversions. These compounds all contain the deoxy sugars L-rhamnose and D-fucose. Isoxestovanin A (125) possesses a new carbon skeleton and xestovanin C (127) and dehydroxestovanin C (132) possess linear
trisaccharide fragments which have not been previously encountered in triterpene
glycosides isolated from X. vanilla.
The Sri Lankan nudibranch Chromodoris glenei has yielded the known compound 12-desacetoxyshahamin C (153) and the new metabolite shahamin K (155). Both compounds possess dendrillane diterpene skeletons. The compound chromodorolide B (156) was isolated from specimens of Chromodoris cavae. It is only the second known diterpene natural product possessing the chromodorane skeleton.Science, Faculty of
Chemistry, Department of
Graduate
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Guest, Michaela A., and n/a. "Movement and Assimilation of Carbon by Estuarine Invertebrates." Griffith University. School of Environmental and Applied Science, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20061024.110617.
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In estuarine and other aquatic systems, it is possible for water to transport locally produced carbon (food) across habitat boundaries, and provide nutrition for animals remote from the carbon source. In estuarine and marine systems, early work examining the movement of carbon from saltmarsh habitats in the USA suggested that carbon may move large distances from inshore to offshore environments. Upon closer examination, however, evidence did not support this paradigm of large-scale carbon movement, referred to as the outwelling hypothesis, in some estuaries. Physical characteristics of estuaries in which large-scale carbon movement did not occur, such as restricted access to the sea, were proposed as a possible explanation, and for these estuaries, movement of carbon among estuarine habitats was considered more likely. A mosaic of saltmarsh and mangrove habitats dominate the subtropical barrier estuary of southern Moreton Bay, Queensland, but there have been no studies that examine the movement of carbon among habitats within this system. Previous studies that examine the movement of carbon have mostly been done in saltmarshes in the northern hemisphere or in tropical mangrove systems. Different vegetation and tidal regimes in temperate marshes of the northern hemisphere preclude generalisations of carbon movement to tropical and subtropical systems. Our understanding of carbon movement in tropical systems may extend to subtropical waters, but the saltmarsh-mangrove mosaic in the subtropics distinguishes them from their tropical counterparts. The mosaic of saltmarsh and mangrove habitats among the barrier islands of southern Moreton Bay thus provide a unique opportunity to examine the small-scale movement of carbon among adjacent habitats in a subtropical system. Stable isotopes of carbon have been used successfully to trace the transfer of carbon from autotrophs to consumers at a range of spatial scales. This method is able to distinguish among carbon sources where autotrophs have different ratios of 13C/12C, and consumers take on the ratio of their food source. The success of stable isotopes in clarifying food web processes, however, depends on isotope ratios changing in predictable ways as elements are processed. As isotope ratios may be influenced by changes in productivity, and differences in nutrient source, they may vary across small and large spatial scales that may confound interpretation of food web processes. In this study I measured small and large-scale spatial variability of three estuarine autotrophs (the saltmarsh grass, Sporobolus virginicus, the seagrass Zostera capricorni and the algal community epiphytic on Z. capricorni) and showed the small-scale spatial variability to be negligible and insufficient to preclude the use of carbon and nitrogen isotopes in food web studies. Large-scale variability was more pronounced and may be useful for spatial correlation of food webs for more mobile species. The small-scale homogeneity and clearly distinguished isotope ratios of the dominant autotrophs in adjacent saltmarsh and mangrove habitats in southeast Queensland are therefore ideally suited to the study of small-scale carbon movement between adjacent habitats. Carbon isotopes of estuarine invertebrates were used to estimate the movement of particulate carbon between adjacent saltmarsh and mangroves at the tens-of-metre scale. Carbon isotope values of two crab species (Parasesarma erythrodactyla and Australoplax tridentata) and two snail species (Salinator solida and Ophicardelus quoyi) in saltmarsh closely match those of the saltmarsh grass, and suggest that the movement and assimilation of carbon occurs at a scale much smaller than has previously been examined. In mangroves, the results of this study indicate that microphytobenthos with some contribution of mangrove carbon is the most likely food source for P. erythrodactyla and A. tridentata, although contribution of carbon from saltmarsh is also possible. Under this latter scenario, carbon movement in mangroves would be considered to occur at a scale larger than that in saltmarsh habitat. A study that examined the movement and assimilation of carbon by crabs and an estuarine slug (Onchidina australis) at a finer resolution (i.e. metres) supported the original findings and indicated that the movement and assimilation of carbon occurs 5 - 8 m either side of the saltmarsh-mangrove interface. At this small-scale, the movement and subsequent foraging of crabs among habitats, the movement of particulate carbon among habitats, or a combination of crab and particulate carbon movement are three alternative models that provide plausible explanations for the pattern in carbon isotope values of crabs. Crab movement among these habitats was measured using an array of pitfall traps perpendicular to the saltmarsh-mangrove interface. To test for carbon movement, samples of detritus were collected at 2 m intervals across this same interface and the carbon isotopes analysed. For the majority of crabs (up to 90% for both species), movement up or down the shore was less than 1 m from the place of initial capture. Thus, crab movement cannot explain the trend in carbon isotope values of crabs. The pattern in detrital isotope values was similar to that of crabs and indicates that the movement of particulate carbon across the saltmarsh-mangrove interface is the most likely explanation for crab isotope ratios. Sources of carbon for estuarine invertebrates can also depend on the size of the saltmarsh patches. Examination of the movement and assimilation of carbon by crabs in saltmarsh patches of different sizes adjacent to mangroves indicates that saltmarshes less than 0.3 ha in area are subsidised by the import of allochthonous carbon, most likely from mangroves. These findings contribute substantially to our understanding of the food web value of estuarine habitats and provide an important link between landscape and food web ecology. They also have important implications for determining the conservation value of estuarine habitats with respect to their functional (food web) value. The scale-dependent sampling used in this thesis also provides important evidence for the fine-scale movement of estuarine carbon that has not previously been examined.
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Cárcamo, Héctor A. "Effects of sulphur pollution on forest floor invertebrates." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24529.pdf.
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Dewi, Ariyanti Suhita. "Biologically active secondary metabolites from tropical marine invertebrates." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/15299.
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In our effort to discover promising anticancer agents, we have screened a series of
compounds for their activities as indoleamine-2,3-dioxygenase (IDO) inhibitor and SHcontaining
inositol 5-phosphatase (SHIP1) activator. In comparison to aaptamine (2.1) and
demethylaaptamine (2.2), isoaaptamine (2.4) from Aaptos cf. suberitoides appears to be the most
promising IDO inhibitor with an IC₅₀ of 0.00215 mg/mL, owing to the presence of hydroxyl
group at C9 position and the methylation at N1 position. A study on the sponge extract of RJA
55275 for its SHIP activator yielded theonellapeptolide Id (3.4), the first peptide that enhanced
the SHIP with 25% activity at concentration 124 μM, thus makes it the most potent SHIP
activator known to date. The third project studied the crystals of a novel eunicellin-based
diterpenoid (4.39) with a modest SHIP activity from an unidentified Micronesian soft coral RJA
47686. The X-ray analysis illustrated that the crystals are monoclinic, space group P21/b, with a
= 9.3711(14) A; α = 90⁰; b = 13.5349(17) A; β = 99.142(7)⁰; c = 10.9891(17) A; γ = 90⁰; V =
1376.1 (3) ų; Z value = 2; Dcalc 1.189. 10-³ g/cm³; F₀₀₀ 536.00; Cu (MoKα) 0.84 cm-¹.
Based on the NMR and x–ray data 4.39 was shown to possess (1R*, 2R*, 3R*, 6R*, 7S*, 10R*,
14R*, 18R*)-configuration with an ether linkage connecting C2 and C6.
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Scott, P. J. B. "Infaunal invertebrates associated with live coral in Jamaica." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74004.
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Larsen, Stefano. "Effects of deposited sediments on temperate stream invertebrates." Thesis, Cardiff University, 2009. http://orca.cf.ac.uk/54935/.
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Nanty, Lisa. "Functional methylomics of apis mellifera and other invertebrates." Thesis, Queen Mary, University of London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.535742.
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Hagger, Josephine Anne. "Evaluation of radionuclide induced damage in marine invertebrates." Thesis, University of Plymouth, 2002. http://hdl.handle.net/10026.1/2483.
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Limited studies have been carried out to assess the potential effects of ionising radiation on marine organisms. Therefore the general aims ofthis thesis were, (a) to assess the cytotoxic, genotoxic and developmental effects of ionising radiation on the embryolarvae of two ecologically relevant marine invertebrates Mytilus edulis and Platynereis dumerilii, (2) to assess the effects of an environmentally relevant cocktail of radionuclides (3) to monitor the potential impact of radiation in the natural environment and finally (4) attempt to predict the potential effects of radiation at a population level. Following validation of developmental stages and mammalian based cytotoxic and genotoxic assays, chromosomal aberrations (Cabs), sister chromatid exchanges (SCEs) and proliferation rate index (PRJ), on the embryo-larvae ofMedulis and P.dumerilii, the embryo-larvae stages were exposed to a reference radionuclide, tritium, (0.37, 3.7, 37 & 370 kBq/ml). Low doses of radiation delivered by tritium were shown to be detrimental to the development of embryo-larvae with an increase in abnormality for P.dumerilii and an increase in mortality for Medulis. Tritium increased the induction of chromosomal aberrations and sister chromatid exchanges, in exposed embryo-larvae, indicating that tritium is potentially genotoxic. Cytotoxic effects (reduction in the cell proliferation rate) were also observed following exposure of embryo-larvae to tritium. In collaboration with the Royal Devonport Dockyard (DML) investigations on the cytotoxic, genotoxic and developmental effects of a cocktail of radionuclides (radioactive liquid waste diluted to 1.8, 3.2, 5.6, 18%) were carried out. All embryo-larvae exposed to 18% radioactive waste were dead within 24h. Both species exhibited increased abnormality, SCEs and Cabs and a reduction in PRJ in dilutions 1.8-5.6%. In general M edulis appeared to be more sensitive to ionising radiation than P.dumerilii embryolarvae. Following experiments on the embryo-larvae stages of the two marine invertebrates studies were carried out to assess the effects of ionising radiation on adult life stages. Following validation of mammalian based genotoxic assays (comet and micronucleus assays) on adult M edulis, the mussels were exposed to a reference radionuclide, tritium, (0.37,3.7,37 & 370 kBq/ml) in an attempt to assess the genotoxic effects of ionising radiation on the adult life stage. An increase in the levels of single strand breaks (comet assay) and in the induction ofmicronuclei (micronucleus assay) in haemocyte cells was observed in adults exposed to tritium. In collaboration with the Royal Devonport Dockyard (DML) a field study was carried out to assess the use ofthe genotoxic assays (comet and micronucleus assays) as biomarkers of exposure to radiation in adult mussels transplanted to an area of radionuclide discharge. Statistical analysis detected no correlation between the health of the deployed mussels and the levels of environmentally realistic radioactivity. After development ofP.dumerilii embryo-larvae to sexual maturity there appeared to be no affect on the number or sex ofthe worms that reached adulthood in comparison to control worms. Although at the highest concentration oftritium (370 kBq/ml) there was a reduction in the number ofeggs produced from sexually matured females. In conclusion, from the current studies it can be stated that ionising radiation is cytotoxic and genotoxic to sensitive embryo-larvae stages ofmarine invertebrates. However further studies need to be carried out to correlate the effects seen at molecular levels with the potential long-term effects observed at population and community levels of these species. 111
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Smith, Karen Lesley. "Immunotoxic biomarkers of anthropogenic impact in marine invertebrates." Thesis, University of Plymouth, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394702.
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Many chemicals enter the marine environment as a result of human activities where they are available to exert a range of effects upon biota. Research has previously focused on the effects of chemicals upon various biological functions of biota in situ. However the impact of chemicals with immunotoxic functions has received little attention. The current research focused on the immunotoxicity of environmental pollutants on marine invertebrates, primarily Mytilus edulis. The aim of the research was to determine to what extent immune function altered in M edulis following exposure to environmental contaminants and how these alterations could be measured and incorporated into environmental monitoring programmes. Exposure of M edulis to the immunotoxicants copper and tributyltin in the laboratory indicated that biochemical measures of immune function were too sensitive for experimental manipulations to be used as biomarkers of pollution-induced stress. However, cellular analysis of immune function, as measured by an adapted immunotoxicity assay in combination with a measure of cell viability, was responsive to pollution-induced stress in a concentration-dependant manner. Cellular immune activity appeared to be regulated by the cytokine IL-1 and involved the release of lytic factors from haemocyte populations. Field evaluation of the immunotoxicity assay in New Bedford Harbour, USA, indicated that environmental contaminants within the estuary had an immuntoxic effect upon in situ mussel populations. The measure of immunotoxicity in mussel populations in New Bedford Harbour was a more sensitive measure of environmental impact than routinely used biomarkers such as lysosomal neutral red, cardiac monitoring and condition index. The immunotoxicity assay is therefore proposed as a sensitive, low cost and reliable biomarker of effect in mussel populations both in the laboratory and the field.
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Khan, Farhan. "Metal speciation in invertebrates from a metallogenic region." Thesis, King's College London (University of London), 2008. http://kclpure.kcl.ac.uk/portal/en/theses/metal-speciation-in-invertebrates-from-a-metallogenic-region(f40bab2d-c04b-4c84-80f8-440fa94673f5).html.
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Bergmann, Melanie. "Fate of discarded invertebrates from Clyde Nephrops fishery." Thesis, University of London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394374.
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Ghanbour, H. A. "Isolation of novel antibiotic producing microorganisms from invertebrates." Thesis, University of Salford, 2018. http://usir.salford.ac.uk/47844/.
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Because of the increased incidence of antibiotic resistance there is an increasing need to isolate new microorganisms producing new antibiotics. Because conventional sources such as soil have been exhausted, attention has been turned to unexplored sources. The aims of this research were to investigate terrestrial and aquatic invertebrates as a source of antibiotic producing microorganisms, to isolate the organisms and screen them for activity against Gram-positive and Gram-negative bacteria. Those with activity would be further characterised. Forty-seven antibiotic producers were isolated from 35 samples of different terrestrial and aquatic invertebrates using media designed to isolate streptomycetes. Identification by PCR and sequencing of 16S and 18S rRNA showed that the majority were in fact fungi, mainly Penicillium spp. and only 5 were Streptomyces spp. Three strains isolated from Helix aspersa (ES1), Lumbriculus variegate (La1a) and Baetis larvae (M1 11) that had strong activity against Gram-positive and Gram-negative bacteria including Methicillin-resistant Staphylococcus aureus (MRSA) were chosen for further study. PCR and sequencing of rRNA and Internal Transcribed Spacer (ITS) regions confirmed that the strains were closely related and were probably strains of P. chrysogenum. The organisms were grown in liquid media and on agar and the active components were extracted with ethyl acetate and fractionated by HPLC. As facilities for large scale liquid cultures were not available large scale preparation was performed from agar medium and the active fractions. HPLC showed that the extracts were complex and contained more than one active component. The purified fractions were chemically characterised by NMR, FTIR and MS. The results showed that the active components were novel flavones and isoflavones. Such compounds have extracted from plants and only previously been shown to be produced by endophytic fungi. The minimal inhibitory concentrations (MIC) against test bacteria and inhibitory concentration IC50 (IC50 is the concentration of a compound at which 50 % of human cancer cell tissue cultures are killed) showed potential for use in chemotherapy as all purified fractions except Es1 F3/3 and Es1 F6 were found to have IC50 values>100 μg/ml, High IC50 and low MIC (0.39 to 50 μg/ml) may indicate fractions suitable for testing for treatment of human infections. The results showed that the invertebrates were indeed a source of antibiotic producing organisms. Whether the organisms were acquired by the invertebrates from the environment or whether they were in a symbiotic association needs further study.
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Suckling, Coleen Claire. "Calcified marine invertebrates : the effects of ocean acidification." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608228.
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Netherton, Melanie Jane. "Uptake and metabolism of pharmaceuticals in aquatic invertebrates." Thesis, University of York, 2011. http://etheses.whiterose.ac.uk/2349/.
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This thesis explored the uptake into the freshwater shrimp (Gammarus pulex) and the water boatman (Notonecta glauca) of key pharmaceuticals drawn from different therapeutic classes and covering a range of physico-chemical properties. For one compound, uptake was also assessed using the freshwater snail Planobarius corneus. In G. pulex, bioconcentration factors (BCFs) ranged from 4.6 – 185900 and increased in the order moclobemide < 5-fluoruracil < carbamazepine < diazepam < carvedilol < fluoxetine. In N. glauca BCFs ranged from 0.1 – 1.6 and increased in the order 5-fluorouracil < carbamazepine < moclobemide < diazepam < fluoxetine < carvedilol. For P. corneus, the BCF for carvedilol was 57.3. The metabolism of the study pharmaceuticals in the shrimp was investigated. Diazepam was found to be metabolized by G. pulex and a metabolite was detected and tentatively identified as nordiazepam. For the other five study compounds no metabolites were observed and it was inferred that metabolism in G. pulex may not influence the BCF. The influence of dietary uptake was explored in the test organisms with carvedilol and fluoxetine. It was found that uptake from water was the predominant route of exposure for G. pulex but the data for N. glauca was contrasting and the exposure from the food was predominant. In both organisms a combination of food and water exposure resulted in a higher uptake of the compounds. The differences in degree of uptake from water across the organisms may be due to differences in mode of respiration, behaviour and the pH of the test system. The differences in degree of uptake from food across the organisms may be due to differences in feeding strategies. The degree of uptake of pharmaceuticals within an organism was related to the hydrophobicity of the pharmaceuticals.
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Hessling, Elin. "Comparing the serotonergic system in vertebrates and invertebrates." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-141218.
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The serotonergic system is involved in a broad range of functions in both vertebrates and invertebrates and is highly conserved across taxa. Serotonin is an important monoamine acting in the brains of humans and animals, and has large and varying influences on many aspects of an individual’s life. For example, in humans, serotonin modulates feelings of happiness and in fruit flies, higher levels of serotonin increase aggression. In humans, an abnormal serotonergic system can result in health issues, such as depression and obsessive compulsive disorders, for which medications have been developed, including selective serotonin reuptake inhibitors (SSRI). Because the serotonin system has a large influence on human health, understanding how it functions is of great interest to researchers. Using comparative studies to explore differences in the serotonin system across taxa can provide insight into the mechanistic details of the system. To investigate if the serotonin system is comparable between vertebrates and invertebrates, a literature study with particular focus on receptors and proteins involved was performed. In addition, this report takes part in an experimental study investigating the effect of the SSRI fluoxetine in Mediterranean field crickets. Fluoxetine reduced exploration propensity of crickets, which was reversed, compared to what was anticipated and compared to effects seen in vertebrates. The literature review suggests that serotonin receptors are quite similar, but that proteins differ more when comparing vertebrates and invertebrates. This offers a likely explanation as to why results of studies on these different groups of animals may differ.
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Guest, Michaela A. "Movement and Assimilation of Carbon by Estuarine Invertebrates." Thesis, Griffith University, 2004. http://hdl.handle.net/10072/367539.
Full textAbstract:
In estuarine and other aquatic systems, it is possible for water to transport locally produced carbon (food) across habitat boundaries, and provide nutrition for animals remote from the carbon source. In estuarine and marine systems, early work examining the movement of carbon from saltmarsh habitats in the USA suggested that carbon may move large distances from inshore to offshore environments. Upon closer examination, however, evidence did not support this paradigm of large-scale carbon movement, referred to as the outwelling hypothesis, in some estuaries. Physical characteristics of estuaries in which large-scale carbon movement did not occur, such as restricted access to the sea, were proposed as a possible explanation, and for these estuaries, movement of carbon among estuarine habitats was considered more likely. A mosaic of saltmarsh and mangrove habitats dominate the subtropical barrier estuary of southern Moreton Bay, Queensland, but there have been no studies that examine the movement of carbon among habitats within this system. Previous studies that examine the movement of carbon have mostly been done in saltmarshes in the northern hemisphere or in tropical mangrove systems. Different vegetation and tidal regimes in temperate marshes of the northern hemisphere preclude generalisations of carbon movement to tropical and subtropical systems. Our understanding of carbon movement in tropical systems may extend to subtropical waters, but the saltmarsh-mangrove mosaic in the subtropics distinguishes them from their tropical counterparts. The mosaic of saltmarsh and mangrove habitats among the barrier islands of southern Moreton Bay thus provide a unique opportunity to examine the small-scale movement of carbon among adjacent habitats in a subtropical system. Stable isotopes of carbon have been used successfully to trace the transfer of carbon from autotrophs to consumers at a range of spatial scales. This method is able to distinguish among carbon sources where autotrophs have different ratios of 13C/12C, and consumers take on the ratio of their food source. The success of stable isotopes in clarifying food web processes, however, depends on isotope ratios changing in predictable ways as elements are processed. As isotope ratios may be influenced by changes in productivity, and differences in nutrient source, they may vary across small and large spatial scales that may confound interpretation of food web processes. In this study I measured small and large-scale spatial variability of three estuarine autotrophs (the saltmarsh grass, Sporobolus virginicus, the seagrass Zostera capricorni and the algal community epiphytic on Z. capricorni) and showed the small-scale spatial variability to be negligible and insufficient to preclude the use of carbon and nitrogen isotopes in food web studies. Large-scale variability was more pronounced and may be useful for spatial correlation of food webs for more mobile species. The small-scale homogeneity and clearly distinguished isotope ratios of the dominant autotrophs in adjacent saltmarsh and mangrove habitats in southeast Queensland are therefore ideally suited to the study of small-scale carbon movement between adjacent habitats. Carbon isotopes of estuarine invertebrates were used to estimate the movement of particulate carbon between adjacent saltmarsh and mangroves at the tens-of-metre scale. Carbon isotope values of two crab species (Parasesarma erythrodactyla and Australoplax tridentata) and two snail species (Salinator solida and Ophicardelus quoyi) in saltmarsh closely match those of the saltmarsh grass, and suggest that the movement and assimilation of carbon occurs at a scale much smaller than has previously been examined. In mangroves, the results of this study indicate that microphytobenthos with some contribution of mangrove carbon is the most likely food source for P. erythrodactyla and A. tridentata, although contribution of carbon from saltmarsh is also possible. Under this latter scenario, carbon movement in mangroves would be considered to occur at a scale larger than that in saltmarsh habitat. A study that examined the movement and assimilation of carbon by crabs and an estuarine slug (Onchidina australis) at a finer resolution (i.e. metres) supported the original findings and indicated that the movement and assimilation of carbon occurs 5 - 8 m either side of the saltmarsh-mangrove interface. At this small-scale, the movement and subsequent foraging of crabs among habitats, the movement of particulate carbon among habitats, or a combination of crab and particulate carbon movement are three alternative models that provide plausible explanations for the pattern in carbon isotope values of crabs. Crab movement among these habitats was measured using an array of pitfall traps perpendicular to the saltmarsh-mangrove interface. To test for carbon movement, samples of detritus were collected at 2 m intervals across this same interface and the carbon isotopes analysed. For the majority of crabs (up to 90% for both species), movement up or down the shore was less than 1 m from the place of initial capture. Thus, crab movement cannot explain the trend in carbon isotope values of crabs. The pattern in detrital isotope values was similar to that of crabs and indicates that the movement of particulate carbon across the saltmarsh-mangrove interface is the most likely explanation for crab isotope ratios. Sources of carbon for estuarine invertebrates can also depend on the size of the saltmarsh patches. Examination of the movement and assimilation of carbon by crabs in saltmarsh patches of different sizes adjacent to mangroves indicates that saltmarshes less than 0.3 ha in area are subsidised by the import of allochthonous carbon, most likely from mangroves. These findings contribute substantially to our understanding of the food web value of estuarine habitats and provide an important link between landscape and food web ecology. They also have important implications for determining the conservation value of estuarine habitats with respect to their functional (food web) value. The scale-dependent sampling used in this thesis also provides important evidence for the fine-scale movement of estuarine carbon that has not previously been examined.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environmental and Applied Science
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