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No description available.

The shell composition of planktonic foraminifera used in many paleoreconstructions assumes they are accurately representing conditions at the surface/mixed layer. However, planktonic foraminifera are known to inhabit a depth range that extends below the mixed layer. In the present study, foraminifera were collected at discrete depth intervals using a Multiple Opening and Closing Net Environmental Sensing System (MOCNESS) in either cyclonic or anticyclonic eddies that had contrasting environmental conditions. The foraminifera abundances and distributions were compared to the water depth, temperature, density, and chlorophyll profiles. Nine species were found consistently among all the tows and composed at least 96% of the species found, though a shift in the species abundances and depths occurred between eddies. Species occurred where physical factors were compatible with conditions and feeding opportunities they were adapted to. Three species pink and white Globigerinoides ruber and Globigerinoides sacculifer thrived best when a steep density gradient resulted in a shallower mixed-layer that restricted them under more intense light and allowed them to better exploit their algae symbionts. Globigerina bulloides was found outside its sub-polar habitat because the waters of the cyclones were cool enough (less than 26??C) at the same depths that sufficient chlorophyll was available. Two species Orbulina universa, and Globorotalia menardii were consistently absent in the mixed layer, but tracked deeper chlorophyll concentrations. Three other species were found inconsistently among the tows: Hastigerina pelagica, Globigerinella siphonifera, and Globigerinella calida. H. pelagica probably follows chlorophyll concentrations. G. siphonifera, and G. calida have a preference for deeper waters within the photic zone. The drastic doubling to tripling of the foraminifera abundances in cyclones biases downcore reconstructions of sea surface temperature towards cooler conditions. Also, the shift in species composition between the two eddies indicates that in environments where eddies, upwellings, or rings exist may bias the downcore composition of each species towards cooler conditions. G. sacculifer was found to live primarily in the mixed layer and at least 75% of its downcore individuals are expected to represent conditions there. Researchers should consider the described species distributions to better understand the water column conditions they are reconstructing.

The shell composition of planktonic foraminifera used in many paleoreconstructions assumes they are accurately representing conditions at the surface/mixed layer. However, planktonic foraminifera are known to inhabit a depth range that extends below the mixed layer. In the present study, foraminifera were collected at discrete depth intervals using a Multiple Opening and Closing Net Environmental Sensing System (MOCNESS) in either cyclonic or anticyclonic eddies that had contrasting environmental conditions. The foraminifera abundances and distributions were compared to the water depth, temperature, density, and chlorophyll profiles. Nine species were found consistently among all the tows and composed at least 96% of the species found, though a shift in the species abundances and depths occurred between eddies. Species occurred where physical factors were compatible with conditions and feeding opportunities they were adapted to. Three species pink and white Globigerinoides ruber and Globigerinoides sacculifer thrived best when a steep density gradient resulted in a shallower mixed-layer that restricted them under more intense light and allowed them to better exploit their algae symbionts. Globigerina bulloides was found outside its sub-polar habitat because the waters of the cyclones were cool enough (less than 26??C) at the same depths that sufficient chlorophyll was available. Two species Orbulina universa, and Globorotalia menardii were consistently absent in the mixed layer, but tracked deeper chlorophyll concentrations. Three other species were found inconsistently among the tows: Hastigerina pelagica, Globigerinella siphonifera, and Globigerinella calida. H. pelagica probably follows chlorophyll concentrations. G. siphonifera, and G. calida have a preference for deeper waters within the photic zone. The drastic doubling to tripling of the foraminifera abundances in cyclones biases downcore reconstructions of sea surface temperature towards cooler conditions. Also, the shift in species composition between the two eddies indicates that in environments where eddies, upwellings, or rings exist may bias the downcore composition of each species towards cooler conditions. G. sacculifer was found to live primarily in the mixed layer and at least 75% of its downcore individuals are expected to represent conditions there. Researchers should consider the described species distributions to better understand the water column conditions they are reconstructing.

The development of biofilms at solid-liquid interfaces has been investigated extensively, whereas the yield of planktonic cells from biofilms has received comparatively little attention. The detachment of single cells from biofilms has been attributed mainly to the erosive action of flowing liquid or the dispersal of cells from within biofilm microcolonies. The result has been an underestimation of the active role that biofilms can play in microbial proliferation through the production and release of planktonic cells to the environment. In this study, the cultivation of Pseudomonas sp. strain CT07 biofilms in conventional flowcells, glass tubes and a novel CO2 evolution measurement system was utilized to show that biofilm-derived planktonic cell yield was initiated within 6 hours of initial surface colonization and increased in conjunction with biofilm development. The magnitude of the yield was influenced by the metabolic activity of the biofilm, which was in turn dependent on environmental conditions, such as carbon availability. The physiologically active region of the biofilm was responsible for the yield of significant numbers of planktonic cells (~107 CFU.cm-2.h-1), whereas a less active biofilm zone was optimized for survival during unfavourable conditions and shown to be responsible for the subsequent re-establishment of biofilm structure, activity and cell yield. Despite the yield of numerically considerable numbers of planktonic cells (~1010 CFU), a carbon balance revealed that the carbon investment required to maintain this yield was insignificant (~1%) compared to the amount of carbon channelled into CO2 production (~54%). Together, these results indicate that biofilm-derived planktonic cell yield represents an efficient proliferation mechanism and support the view that the biofilm lifestyle affords microbes a dual survival-proliferation strategy, where the dominant strategy depends on the prevailing environmental conditions. An alternative model of biofilm development is presented to account for planktonic cell yield during all stages of biofilm development.

The development of biofilms at solid-liquid interfaces has been investigated extensively, whereas the yield of planktonic cells from biofilms has received comparatively little attention. The detachment of single cells from biofilms has been attributed mainly to the erosive action of flowing liquid or the dispersal of cells from within biofilm microcolonies. The result has been an underestimation of the active role that biofilms can play in microbial proliferation through the production and release of planktonic cells to the environment. In this study, the cultivation of Pseudomonas sp. strain CT07 biofilms in conventional flowcells, glass tubes and a novel CO2 evolution measurement system was utilized to show that biofilm-derived planktonic cell yield was initiated within 6 hours of initial surface colonization and increased in conjunction with biofilm development. The magnitude of the yield was influenced by the metabolic activity of the biofilm, which was in turn dependent on environmental conditions, such as carbon availability. The physiologically active region of the biofilm was responsible for the yield of significant numbers of planktonic cells (~107 CFU.cm-2.h-1), whereas a less active biofilm zone was optimized for survival during unfavourable conditions and shown to be responsible for the subsequent re-establishment of biofilm structure, activity and cell yield. Despite the yield of numerically considerable numbers of planktonic cells (~1010 CFU), a carbon balance revealed that the carbon investment required to maintain this yield was insignificant (~1%) compared to the amount of carbon channelled into CO2 production (~54%). Together, these results indicate that biofilm-derived planktonic cell yield represents an efficient proliferation mechanism and support the view that the biofilm lifestyle affords microbes a dual survival-proliferation strategy, where the dominant strategy depends on the prevailing environmental conditions. An alternative model of biofilm development is presented to account for planktonic cell yield during all stages of biofilm development.

Made available in DSpace on 2014-06-11T19:35:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-02Bitstream added on 2014-06-13T19:05:53Z : No. of bitstreams: 1 neves_gp_dr_botib.pdf: 4613254 bytes, checksum: c98056f453471613dcd37c08240edc51 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Foram estudados copépodes planctônicos das ordens Cyclopoida e Calanoida na bacia do rio da Prata, a segunda maior da América do Sul. Amostraram-se no verão e no inverno, 43 locais, incluindo trechos lóticos e reservatórios, esses últimos amostrados nas zonas de montante e próximo as barragens. As coletas foram feitas através de arrastos verticais na coluna de água com rede cônica de plâncton de malha de 68μm. Na análise dos organismos, foram elaborados inicialmente cinco capítulos, porém um deles já foi submetido e está apresentado em forma de anexo. Nos quatro capítulos gerados e incluídos no formato final da tese, constam: 1. Guia de identificação de copépodes planctônicos das ordens Cyclopoida e Calanoida; 2. Redescrição de uma espécie rara de Diaptomidae – Odontodiaptomus thomseni; 3. Atributos ecológicos básicos de copépodes planctônicos Cyclopoida e Calanoida na bacia do rio da Prata; e 4. Limites de distribuição geográfica de Diaptomidae na bacia do Prata, com síntese de processos históricos e atuais. No guia de identificação são apresentadas chaves de identificação, diagnoses taxonômicas, comentários gerais, ilustrações, imagens de microscopia eletrônica de varredura para 37 espécies, sendo consideradas as fêmeas de Cyclopoida e os machos de Calanoida. Nesse capítulo 1, espécies com status taxonômico incerto não foram incluídas. Para os atributos ecológicos no capítulo 3, o número de espécies utilizado nos cálculos de riqueza e diversidade foi maior, e os resultados apontaram maiores riquezas nos trechos médio e baixo do rio Paraná, no verão e inverno, respectivamente. Por fim, no capítulo 4, as tendências de evolução dos Diaptominae são apresentadas, para os quais são verificados padrões de endemismo para elevado número de espécie, sugerindo processos evolutivos... / The planktonic copepods of Cyclopoida and Calanoida orders of the ―La Plata‖ River Basin, the second largest in South America, were studied. Samples were obtained during summer and winter at 43 stations distributed in river stretches and reservoirs (considering upstream and dam zones). Samplings were performed through vertical hauls of plankton net of 68μm of mesh size in the water column. The results of the study are presented in 4 chapters, besides an annex (submitted as a paper): 1. Guide of identification of planktonic copepods of Cyclopoida and Calanoida orders; 2. Redescription of one rare species of Diaptomidae – Odontodiaptomus thomseni; 3. Basic ecological attributes of planktonic cyclopoid and calanoid copepods of ―La Plata‖ River Basin; and 4. Boundaries of geographic distribution of Diaptomidae in ―La Plata‖ Basin, with synthesis of historic and current processes. In the guide of identification are presented keys of identification, taxonomic diagnosis, general commentaries, illustrations, scan electron microscopy images of 37 species, for cyclopoids females and calanoids males. In chapter one, species with incertae status were not included. For ecological attributes in chapter three, the number of species included in richness and diversity calculations was higher, and the results points to major richness in the middle and low stretches of Parana River, in summer and winter, respectively. Finally, in chapter four, the evolution tendencies of Diaptominae are discussed, which point to high endemism patterns for many species, suggesting an ancient evolution processes after Cretaceous separation of the continents, when the Brazilian shield was used as refuge along the time until the current fauna status

The limnological investigation of any body of water is undertaken in order to secure more accurate information concerning the factors which play an important role in fish production or sanitation. This study shows the qualitative and quantitative planktonic algae in Lake Dallas, for the year 1937-38.

Orientador: Marcos Gomes Nogueira / Coorientador: Carlos Eduardo Falavigna da Rocha / Coorientador: Geoff Boxshall / Banca: Janet W. Reid / Banca: Edinaldo Nelson dos Santos Silva / Banca: Fábio A. Lansac Tôha / Banca: Odete Rocha / Resumo: Foram estudados copépodes planctônicos das ordens Cyclopoida e Calanoida na bacia do rio da Prata, a segunda maior da América do Sul. Amostraram-se no verão e no inverno, 43 locais, incluindo trechos lóticos e reservatórios, esses últimos amostrados nas zonas de montante e próximo as barragens. As coletas foram feitas através de arrastos verticais na coluna de água com rede cônica de plâncton de malha de 68μm. Na análise dos organismos, foram elaborados inicialmente cinco capítulos, porém um deles já foi submetido e está apresentado em forma de anexo. Nos quatro capítulos gerados e incluídos no formato final da tese, constam: 1. Guia de identificação de copépodes planctônicos das ordens Cyclopoida e Calanoida; 2. Redescrição de uma espécie rara de Diaptomidae - Odontodiaptomus thomseni; 3. Atributos ecológicos básicos de copépodes planctônicos Cyclopoida e Calanoida na bacia do rio da Prata; e 4. Limites de distribuição geográfica de Diaptomidae na bacia do Prata, com síntese de processos históricos e atuais. No guia de identificação são apresentadas chaves de identificação, diagnoses taxonômicas, comentários gerais, ilustrações, imagens de microscopia eletrônica de varredura para 37 espécies, sendo consideradas as fêmeas de Cyclopoida e os machos de Calanoida. Nesse capítulo 1, espécies com status taxonômico incerto não foram incluídas. Para os atributos ecológicos no capítulo 3, o número de espécies utilizado nos cálculos de riqueza e diversidade foi maior, e os resultados apontaram maiores riquezas nos trechos médio e baixo do rio Paraná, no verão e inverno, respectivamente. Por fim, no capítulo 4, as tendências de evolução dos Diaptominae são apresentadas, para os quais são verificados padrões de endemismo para elevado número de espécie, sugerindo processos evolutivos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The planktonic copepods of Cyclopoida and Calanoida orders of the ―La Plata‖ River Basin, the second largest in South America, were studied. Samples were obtained during summer and winter at 43 stations distributed in river stretches and reservoirs (considering upstream and dam zones). Samplings were performed through vertical hauls of plankton net of 68μm of mesh size in the water column. The results of the study are presented in 4 chapters, besides an annex (submitted as a paper): 1. Guide of identification of planktonic copepods of Cyclopoida and Calanoida orders; 2. Redescription of one rare species of Diaptomidae - Odontodiaptomus thomseni; 3. Basic ecological attributes of planktonic cyclopoid and calanoid copepods of ―La Plata‖ River Basin; and 4. Boundaries of geographic distribution of Diaptomidae in ―La Plata‖ Basin, with synthesis of historic and current processes. In the guide of identification are presented keys of identification, taxonomic diagnosis, general commentaries, illustrations, scan electron microscopy images of 37 species, for cyclopoids females and calanoids males. In chapter one, species with incertae status were not included. For ecological attributes in chapter three, the number of species included in richness and diversity calculations was higher, and the results points to major richness in the middle and low stretches of Parana River, in summer and winter, respectively. Finally, in chapter four, the evolution tendencies of Diaptominae are discussed, which point to high endemism patterns for many species, suggesting an ancient evolution processes after Cretaceous separation of the continents, when the Brazilian shield was used as refuge along the time until the current fauna status / Doutor

The Region of Western Pacific Warm Pool (WPWP) is closely related to Global climate system. Previous studies indicate that the region of WPWP is affected by Walker circulation (WC) and Hadley cell (HC). WPWP expands when WC becomes stronger or when HC becomes weaker, and contracts when WC becomes weaker or when HC becomes stronger. In this study, records derived from core ODP1115B, including stable oxygen and carbon isotopes are used to reconstruct the long-term hydrological variations of WPWP over the past 2.2 Ma. We compared two species of foraminifera: Neogloboquadrina dutertrei and Globigerinoides sacculifer, for the reconstruction of differences between surface water and oceanic subsurface water. We try to find out the relationships between the thermocline depth in southern WPWP, the region of WPWP, HC and WC. However, our records indicate that the depth of thermocline in southern WPWP may be effected by the region of WPWP and the hydrology of southern WPWP. According to the Paleothermometry records of ODP806, ODP847, ODP1115 and MD063018, we can explain the relationship between WC, HC and the region of WPWP. Before 1.8 Ma, southern WPWP may not be affected by weak WC. During 1.8~1.2 Ma, WC becomes stronger and effect the region of WPWP. At the period of 1.2~0.9 Ma, southward migration of WPWP enhanced the influence of WC on the region of south WPWP and the depth of thermocline, then weakened HC in the southern hemisphere. After 0.9 Ma, the variation of hydrology in southern WPWP may be affected by stronge WC, not HC. We suggest that the influence of HC in southern WPWP is resulted in the southern region of WPWP.