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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
491

Improving the discrimination of primary and secondary sources of organic aerosol : use of molecular markers and different approaches / Amélioration de la discrimination des sources primaires et secondaires de l'aérosol organique : utilisation de marqueurs moléculaires et de différentes approches

Srivastava, Deepchandra 26 April 2018 (has links)
Les aérosols organiques (AO), issus de nombreuses sources et de différents processus atmosphériques, ont un impact significatif sur la qualité de l’air et le changement climatique. L’objectif de ce travail de thèse était d’acquérir une meilleure connaissance de l’origine des AO par l’utilisation de marqueurs organiques moléculaires au sein de modèles source-récepteur de type positive matrix factorization (PMF). Ce travail expérimental était basé sur deux campagnes de prélèvements réalisées à Grenoble (site urbain) au cours de l’année 2013 et dans la région parisienne (site péri-urbain du SIRTA, 25 km au sud-ouest de Paris) lors d’un intense épisode de pollution aux particules (PM) en Mars 2015. Une caractérisation chimique étendue (de 139 à 216 espèces quantifiées) a été réalisée et l’utilisation de marqueurs moléculaires primaires et secondaires clés dans la PMF a permis de déconvoluer de 9 à 11 sources différentes de PM10 (Grenoble et SIRTA, de façon respective) incluant aussi bien des sources classiques (combustion de biomasse, trafic, poussières, sels de mer, nitrate et espèces inorganiques secondaires) que des sources non communément résolues telles que AO biogéniques primaires (spores fongiques et débris de plantes), AO secondaires (AOS) biogéniques (marin, oxydation de l’isoprène) et AOS anthropiques (oxydation des hydrocarbures aromatiques polycycliques (HAP) et/ou des composés phénoliques). En outre, le jeu de données obtenu pour la région parisienne à partir de prélèvements sur des pas de temps courts (4h) a permis d’obtenir une meilleure compréhension des profils diurnes et des processus chimiques impliquées. Ces résultats ont été comparés à ceux issus d’autres techniques de mesures (en temps réel, ACSM (aerosol chemical speciation monitor) et analyse AMS (aerosol mass spectrometer) en différée) et/ou d’autres méthodes de traitement de données (méthodes traceur EC (elemental carbon) et traceur AOS). Un bon accord a été obtenu entre toutes les méthodes en termes de séparation des fractions primaires et secondaires. Cependant, et quelle que soit l’approche utilisée, la moitié de la masse d’AOS n’était toujours pas complètement décrite. Ainsi, une nouvelle approche d’étude des sources de l’AO a été développée en combinant les mesures en temps réel (ACSM) et celles sur filtres (marqueurs moléculaires organiques) et en utilisant un script de synchronisation des données. L’analyse PMF combinée a été réalisée sur la matrice de données unifiée. 10 facteurs AO, incluant 4 profils chimiques différents en lien avec la combustion de biomasse, ont été mis en évidence. Par rapport aux approches conventionnelles, cette nouvelle méthodologie a permis d’obtenir une meilleure compréhension des processus atmosphériques liés aux différentes sources d’AO. / Organic aerosols (OAs), originating from a wide variety of sources and atmospheric processes, have strong impacts on air quality and climate change. The present PhD thesis aimed to get a better understanding of OA origins using specific organic molecular markers together with their input into source-receptor model such as positive matrix factorization (PMF). This experimental work was based on two field campaigns, conducted in Grenoble (urban site) over the 2013 year and in the Paris region (suburban site of SIRTA, 25 km southwest of Paris) during an intense PM pollution event in March 2015. Following an extended chemical characterization (from 139 to 216 species quantified), the use of key primary and secondary organic molecular markers within the standard filter-based PMF model allowed to deconvolve 9 and 11 PM10 sources (Grenoble and SIRTA, respectively). These included common ones (biomass burning, traffic, dust, sea salt, secondary inorganics and nitrate), as well as uncommon resolved sources such as primary biogenic OA (fungal spores and plant debris), biogenic secondary AO (SOA) (marine, isoprene oxidation) and anthropogenic SOA (polycyclic aromatic hydrocarbons (PAHs) and/or phenolic compounds oxidation). In addition, high time-resolution filter dataset (4h-timebase) available for the Paris region also illustrated a better understanding of the diurnal profiles and the involved chemical processes. These results could be compared to outputs from other measurement techniques (online ACSM (aerosol chemical speciation monitor), offline AMS (aerosol mass spectrometer) analyses), and/or to other data treatment methodologies (EC (elemental carbon) tracer method and SOA tracer method). A good agreement was obtained between all the methods in terms of separation between primary and secondary OA fractions. Nevertheless, and whatever the method used, still about half of the SOA mass was not fully described. Therefore, a novel OA source apportionment approach has finally been developed by combining online (ACSM) and offline (organic molecular markers) measurements and using a time synchronization script. This combined PMF analysis was performed on the unified matrix. It revealed 10 OA factors, including 4 different biomass burning-related chemical profiles. Compared to conventional approaches, this new methodology provided a more comprehensive description of the atmospheric processes related to the different OA sources.
492

Observação do transporte de sedimentos em suspensão ao longo do Canal Norte do rio Amazonas durante condições de baixa descarga (outubro 2008) / Observation of suspended sediment transport along North Channel of Amazon river during low discharge (October 2008)

Edgard Villarinho Garcia Neto 21 October 2011 (has links)
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / The Amazon river, located in northernBrazil, discharges between 80,000 and 250,000 m3s-1 of water onto the adjacent shelf, creating a plume of brackish water that extends hundreds of kilometers away from the river mouth. This river also carries a large amount of fine sediments to the ocean where fluid mud has been found in the topset and upper foreset layers of the subaqueous delta formed on the mid-shelf. One of the main goals of this dissertation is to describe how turbulence and suspended sediment concentration vary along the Northern Channel of the Amazon river. Water column measurements were carried out in October 2008 at six anchor stations (P1, P3, P5, P6, P8 e P9) located seaward of the river mouth; P1 and P9 were 125 km apart. Each station was occupied during 13 hours during which current speed and direction were continuously sampled with a 600 kHz Teledyne-RDI ADCP; hourly profiles of temperature, salinity, turbidity and depth were also obtained. Water samples were collected for determination of Suspended Particulate Matter (SPM) concentration and calibration of the turbidity sensor. Current speed reached values above 1.5 m s1 in the along-channel direction (NE-SW); a remarkable ebb-flood asymmetry was observed and flows were strongly ebb-dominated. Throughout the water column, SPM concentration at stations P1 and P3 varied between 100 and 300 mg L1 in association with the presence of freshwater. In contrast, a strong salinity gradient was observed between stations P6 and P9, coinciding with the occurrence of concentrations of SPM above 10 g L-1 (fluid mud). At stations P3, P5 and P6, interface between freshwater from the Amazon river and salt water from the continental shelf, shear stresses wereestimated through four diferents methods: Reynolds, Turbulent Kinetic Energy (TKE), modified TKE and Quadratic Law; in the nearbed region (3 mab) the computed values varied between 0 and 3 Pa. At the three stations (P3, P5 and P6) the lowest and the highest shear stress values were obtained through, respectively, the Reynolds and the TKE methods. Over the whole water column turbulence intensity was estimated through the standard deviation of the turbulent component of the along-channel current velocity (root-mean square of u); from these values, it was estimated the turbulent dissipation of energy (G), whose values at 3 mab varied between zero and 20 s1.
493

Efeitos da exposição crônica à poluição atmosférica particulada sobre o desenvolvimento embrionário pré-implantacional in vitro em camundongos / Effects of chronic exposure to particulate air pollution on in vitro preimplantation embryo development in mice

Mariangela Maluf 25 July 2008 (has links)
Um Projeto Temático de Pesquisa foi desenvolvido no Laboratório de Poluição Ambiental do Departamento de Patologia da Faculdade de Medicina da Universidade de São Paulo com o objetivo de avaliar os efeitos da exposição aguda/crônica ao ar ambiente de um grande centro urbano sobre a saúde. Dentro deste projeto, uma linha de pesquisa foi dedicada ao estudo dos efeitos dessa exposição sobre a saúde reprodutiva feminina. Evidências de estudos epidemiológicos e experimentais implicam os fatores ambientais na infertilidade humana e resultado obstétrico adverso. Contudo, poucos estudos foram conduzidos até o presente para avaliar um possível efeito da exposição à poluição ambiental particulada sobre a saúde reprodutiva feminina. Portanto, o objetivo dos projetos da minha linha de pesquisa é fornecer dados que possam demonstrar os possíveis efeitos da exposição crônica à poluição ambiental particulada sobre a função ovariana e o desenvolvimento embrionário inicial. O objetivo do primeiro projeto desta tese foi avaliar diferentes metodologias utilizadas para a coloração diferencial das linhagens celulares do blastocisto, um método mais adequado para a avaliação de sua qualidade e normalidade. As células de blastocistos intactos de camundongo obtidos através de fertilização in vitro (FIV) foram permeabilizadas e coradas utilizando-se diferentes concentrações de um detergente (TX-100; 0,5% ou 1%) e de iodeto de propídeo (IP; 50 g/mL ou 100 g/mL) e depois disso, incubadas durante a noite em uma solução contendo diferentes fixadores (etanol, metanol, paraformaldeído PFA1% ou 4%) e bisbenzimida. Para a avaliação da qualidade de coloração e contagem diferencial dos núcleos, os blastocistos foram montados em lâminas de vidro e analisados em um microscópio de epifluorescência. O escore de qualidade de coloração foi significativamente diferente (p<0,05) entre todas as soluções fixadoras, sendo maior para o etanol, seguido pelo metanol, PFA1% e PFA4%. Mudanças da concentração do IP e o uso de diferentes soluções de fixação revelaram efeitos significativos na contagem de células da massa celular interna (MCI) e na razão MCI/trofectoderma (TE). Concentrações diferentes do detergente utilizado para a permeabilização celular apresentaram efeitos significativos sobre a contagem de células TE e razão MCI/TE. Concluímos que o protocolo que utiliza TX-100 1% para a permeabilização celular, 50 g/mL de IP para coloração das células TE e etanol como solução de fixação representa o método mais eficiente para a coloração diferencial e contagem das células das linhagens celulares do embrião no estágio de blastocisto. No segundo projeto que compõe esta, o objetivo foi avaliar os efeitos da exposição pré e/ou pós-natal ao ar ambiente sobre a fertilização, desenvolvimento embrionário e segregação das linhagens celulares em blastocistos pré-implantacionais, utilizando o modelo de FIV de camundongo. Fêmeas de camundongo com idade de seis semanas tiveram a ovulação estimulada e foram expostas no período pré- e/ou pós-natal ao ar filtrado (AF-AF), ar filtrado ar ambiente (AF-AA) ou ar ambiente ar ambiente (AA-AA) em câmaras de exposição 24 horas por dia, sete dias na semana, durante nove semanas. Os pontos de avaliação reprodutivos analisados incluíram a duração da gestação, tamanho e peso da prole, índice de nascidos vivos, razão sexual, resposta ovariana à estimulação, taxa de fertilização, desenvolvimento embrionário, taxas de formação e de eclosão dos blastocistos, contagem celular total e proporção da alocação celular à MCI e TE. A duração da gestação, tamanho e peso da prole, índice de nascidos vivos e razão sexual foram similares nos diferentes grupos de exposição. A resposta ovariana não foi afetada pelo protocolo de exposição. Um efeito multivariável para a exposição pré e/ou pós-natal ao material particulado fino ambiente sobre a FIV, o desenvolvimento embrionário e a coloração diferencial dos blastocistos foi observado. A contagem celular na MCI e a razão MCI/TE dos blastocistos produzidos no protocolo AF-AF foram significativamente maiores do que aquelas em blastocistos produzidos nos protocolos FA-AA e AA-AA. Nenhuma diferença na contagem celular total foi observada. Baseando-se nessas observações, nosso estudo sugere que a exposição ao material particulado fino presente no ar ambiente de um grande centro urbano pode afetar negativamente a saúde reprodutiva feminina através da alteração da especificação das linhagens celulares do embrião no estágio de blastocisto. Finalmente, o propósito do terceiro projeto que compõe esta tese foi de avaliar os efeitos da exposição pré e/ou pósnatal ao ar ambiente no final da vida reprodutiva sobre a fertilização, desenvolvimento embrionário e segregação das linhagens celulares em blastocistos pré-implantacionais, utilizando o modelo de FIV de camundongo. Fêmeas de camundongo com idade de cinco meses tiveram a ovulação estimulada e foram expostas no período pré e/ou pós-natal ao ar filtrado (AF-AF), ar filtrado ar ambiente (AF-AA) ou ar ambiente ar ambiente (AA-AA) em câmaras de exposição 24 horas por dia, sete dias na semana, durante seis meses. Os pontos de avaliação reprodutivos foram os mesmos que aqueles utilizados no segundo projeto. A duração da gestação, tamanho e peso da prole, índice de nascidos vivos e razão sexual foram similares nos diferentes grupos de exposição. A resposta ovariana não foi afetada pelo protocolo de exposição. Um efeito multivariável para a exposição pré e/ou pós-natal ao material particulado fino ambiente sobre coloração diferencial dos blastocistos, mas não sobre a FIV e o desenvolvimento embrionário, foi observado. A contagem celular na MCI e a razão MCI/TE dos blastocistos produzidos no protocolo AF-AF foram significativamente maiores do que aquelas em blastocistos produzidos nos protocolos FA-AA e AA-AA. A contagem celular do TE dos blastocistos produzidos no protocolo FA-FA foi significativamente menor do que aquela em blastocistos produzidos nos protocolos FA-AA e AA-AA. A contagem celular total foi similar entre os grupos. Nosso estudo sugere que a exposição à poluição ambiental particulada de um grande centro urbano não altera a função ovariana, mas pode afetar negativamente a saúde reprodutiva feminina no período final do menacme, através da alteração da especificação das linhagens celulares do embrião no estágio de blastocisto / A thematic research project to evaluate the health effects of acute/chronic exposure to ambient air in a large urban center was developed at the Air Pollution Laboratory in the Department of Pathology at the University of São Paulo School of Medicine. Within this project a specific research line was committed to the study of the effects of this exposure on female reproductive health. Evidence from epidemiological and experimental studies implied environmental factors as possible contributors to human infertility and poor obstetric outcome. However, very few studies evaluating a possible effect of exposure to particulate air pollution on female reproductive health have been conducted so far. Thus, the aim of the projects in my research line was to provide data that could show the possible effects of chronic exposure to particulate air pollution on ovarian function and early embryo development. The objective of the first project was to assess different methodologies used in cell lineage differential staining of the blastocyst, a method for more accurate evaluation of its quality and normality. Cells of zona-intact mouse blastocysts obtained from in vitro fertilization (IVF) were permeabilized and stained using different concentrations of a detergent (TX-100; 0.5% or 1%) and propidium iodide (PI; 50 g/mL or 100 g/mL) followed by overnight incubation in a solution containing different fixatives (ethanol, methanol, paraformaldehyde - PFA 1% or 4%) and bisbenzimide. To evaluate the staining quality and count the nuclei differentially, blastocysts were mounted and viewed using epifluorescence microscopy. Staining quality scores were significantly different (P < 0.05) among all fixative solutions with the highest for ethanol followed by methanol, PFA1%, and PFA4%. Changes in PI concentration and use of different fixative solutions revealed significant effects on inner cell mass (ICM) cell count and ICM/trophectoderm (TE) ratio. Different concentrations of the detergent used for cell permeabilization showed significant effects on TE cell counts and ICM/TE ratio. I concluded that the protocol using 1% TX-100 for cell permeabilization, 50 g/mL of PI for TE cell staining, and ethanol as a fixative solution is the most efficient method for cell lineage differential staining and counting at the blastocyst stage. In the second project the objective was to evaluate the effects of preand/ or postnatal exposure to ambient air on fertilization, embryo development, and cell lineage segregation in preimplantation blastocysts using the IVF mouse model. Six-week old superovulated mice were preand/ or postnatally exposed to filtered air (FA-FA), filtered-ambient air (FAAA), or ambient air (AA-AA) in exposure chambers 24/7 for nine weeks. Reproductive endpoints evaluated included gestation length, litter size, litter birth weight, live birth index, sex ratio, ovarian response to superovulation, fertilization rate, embryo development, blastocyst and hatching rates, total cell count, and proportion of cell allocation to ICM and TE. Gestation length, litter size, litter birth weight, live birth index, and sex ratio were similar among exposure groups. Ovarian response was not affected by the exposure protocol. A multivariate effect for pre- and/or postnatal exposure to ambient fine particulate matter on IVF, embryo development, and blastocyst differential staining was found. Cell counts in ICM and ICM/TE ratios in blastocysts produced in the FA-FA protocol were significantly higher than in blastocysts produced in FA-AA and AA-AA protocols. No difference in the total cell count was observed. Based on these observations the study suggests that exposure to ambient fine particulate matter in a large urban center may negatively affect female reproductive health by disrupting the lineage specification at the blastocyst stage. Finally, the purpose of the third project was to evaluate the effects of pre- and/or postnatal exposure to particulate air pollution on fertilization, embryo development, and cell lineage segregation in preimplantation blastocysts during the late-life reproductive period using the IVF mouse model. Five-month-old superovulated mice were pre- and/or postnatally exposed to filtered air (FA-FA), filtered-ambient air (FA-AA), or ambient air (AA-AA) in exposure chambers 24/7 during six months. Reproductive endpoints were the same as the ones selected for the second project. Gestation length, litter size, litter birth weight, live birth index, and sex ratio were similar among exposure groups. Ovarian response was not affected by the exposure protocol. A multivariate effect for pre- and/or postnatal exposure to ambient air on blastocyst differential staining but not on IVF and embryo development was found. Cell counts in ICM and ICM/TE ratios in blastocysts produced in the FA-FA protocol were significantly higher than in blastocysts produced in FA-AA and AA-AA protocols. Cell counts in TE cells in blastocysts produced in the FA-FA protocol were significantly lower than in blastocysts produced in FA-AA and AA-AA protocols. The total cell count was similar among groups. This study suggests that exposure to particulate air pollution in a large urban center has no effect on ovarian function but may negatively affect female reproductive health in the late-life period by disrupting the lineage specification at the blastocyst stage.
494

Efeitos da exposição pré-concepcional de curta duração ao material particulado ambiental sobre o mecanismo reprodutivo feminino / Effects of short-term preconceptional exposure to ambient particulate matter on female reproductive function

Paulo Marcelo Perin 25 July 2008 (has links)
Um Projeto Temático de Pesquisa foi desenvolvido no Laboratório de Poluição Ambiental do Departamento de Patologia da Faculdade de Medicina da Universidade de São Paulo com o objetivo de avaliar os efeitos da exposição aguda/crônica ao ar ambiente de um grande centro urbano sobre a saúde. Dentro deste projeto, uma linha de pesquisa foi dedicada ao estudo dos efeitos dessa exposição sobre a saúde reprodutiva feminina. Evidências de estudos epidemiológicos e experimentais implicam os fatores ambientais na infertilidade humana e resultado obstétrico adverso. Contudo, poucos estudos foram conduzidos até o presente para avaliar um possível efeito da exposição à poluição ambiental particulada sobre a saúde reprodutiva feminina. Portanto, o objetivo dos projetos da minha linha de pesquisa é fornecer dados que possam demonstrar os possíveis efeitos da exposição pré-concepcional de curta duração às partículas de exaustão do diesel (PED) e à poluição ambiental particulada sobre a função ovariana, o desenvolvimento embrionário inicial e resultado gestacional utilizando um modelo experimental e um epidemiológico. O objetivo do primeiro projeto desta tese foi avaliar os efeitos de dois meios de cultura comerciais no desenvolvimento de oócitos de camundongo fertilizados in vitro até o estágio de blastocisto. Zigotos obtidos de fêmeas de camundongo de 8 semanas de idade submetidas à indução da ovulação foram cultivados in vitro até o estágio de blastocisto em meio simples otimizado enriquecido com potássio (KSOM) ou meio G1/G2. A porcentagem de zigotos que se desenvolveu até o estágio de blastocisto 96 e 120 horas após a inseminação e que sofreu eclosão parcial ou completa no quinto dia de cultivo foi significativamente maior no grupo KSOM. O número médio de células da massa celular interna (MCI) foi 11,7 ± 4,0 e 9,2 ± 5,2 para os zigotos cultivados nos grupos KSOM e G1/G2, respectivamente, mostrando um número significativamente maior de células MCI em blastocistos derivados da cultura no meio KSOM. Concluímos que o meio KSOM comercialmente disponível é superior ao meio seqüencial G1/G2 para o cultivo de zigotos até o estágio de blastocisto no modelo de fertilização in vitro (FIV) em camundongos. No segundo projeto que compõe esta tese, o objetivo foi avaliar os efeitos da exposição de curta duração às PED sobre a fertilização, desenvolvimento embrionário e segregação das linhagens celulares em blastocistos pré-implantacionais utilizando o modelo de FIV em camundongo. A instilação intranasal de água destilada (grupo controle), de PED nativas (grupo PED-N) ou de PED ácidoextraídas (grupo PED-AE), realizada uma vez ao dia por três dias, iniciada no primeiro dia de administração de gonadotrofinas, foi realizada em fêmeas de camundongo com oito semanas de idade. Os pontos de avaliação reprodutivos analisados incluíram a resposta ovariana a estimulação, taxa de fertilização, desenvolvimento embrionário, taxas de formação e de eclosão dos blastocistos, contagem celular total e proporção da alocação celular à MCI e trofoectoderma (TE), e a morfologia da MCI. A resposta ovariana não foi afetada pelo protocolo de exposição. Um efeito multivariado para a exposição às PED-N e PED-AE na coloração diferencial de blastocistos e na morfologia da MCI, mas não para a FIV ou desenvolvimento embrionário, foi observado. A contagem celular da MCI e a razão MCI/TE em blastocistos produzidos no grupo controle foram significativamente maiores do que em blastocistos produzidos nos grupos PED-N e PED-AE. O número total de células dos blastocistos foi similar entre os grupos. O escore que representa a morfologia da massa celular interna foi significativamente maior no grupo controle quando comparado àquele encontrado nos grupos PED-N e PEDAE. Baseando-se nesses resultados, nosso estudo sugere que a exposição de curta duração às PED pode afetar negativamente o processo reprodutivo através do distúrbio da especificação das linhagens celulares do embrião em estágio de blastocisto. Finalmente, a exposição a toxinas ambientais pode ser inevitável durante o período pré-concepcional em grandes centros urbanos e seus efeitos são desconhecidos. Portanto, o propósito do terceiro projeto que compõe esta tese foi avaliar os potenciais efeitos da exposição de curta duração à poluição ambiental particulada durante a fase folicular sobre os resultados clínicos, laboratoriais e gestacionais de casais submetidos à fertilização in vitro e transferência de embriões (FIVETE). Trezentos e quarenta e oito mulheres submetidas ao seu primeiro ciclo de FIVETE foram avaliadas retrospectivamente neste estudo coorte, casocontrole casado. A exposição ao material particulado ambiental (MP) durante a fase folicular de cada paciente foi estimada baseando-se em dados da poluição ambiental (1997-2006) categorizados em período Q1-3 ( 56,72 g/m3) e Q4 (>56,72 g/m3). Desse grupo, 177 pacientes que engravidaram (casos) foram comparadas com 354 mulheres que conceberam espontaneamente (controles). Os principais pontos de avaliação incluíram a resposta ovariana às gonadotrofinas, o número de oócitos recuperados e as taxas de fertilização, de clivagem, de qualidade embrionária, de implantação, de gestação, de abortamento e de nascidos vivos. Nenhum efeito da exposição a níveis elevados de MP durante a fase folicular foi observado nos resultados clínico e laboratorial, na transferência embrionária ou no sucesso dos ciclos de tratamento das pacientes submetidas à FIVETE. Mulheres expostas ao período Q4 durante a fase folicular do ciclo de concepção apresentaram um risco significativamente maior de abortamento, independentemente do método de concepção (razão de chance: 2,58; intervalo de confiança de 95%: 1,63 4,07), quando comparado àquele de mulheres expostas ao período Q1-3. O risco de perda da gestação aumentou 3% por unidade de aumento do valor médio do MP na fase folicular (p= 0,000). Os resultados apresentados aqui fornecem evidências para uma relação causal entre a breve exposição a níveis elevados de MP ambiente durante o período pré-concepcional e a perda gestacional inicial, independentemente do método de concepção e está associada a um aumento de 2,6 vezes no risco de abortamento. Apesar da ausência de efeitos dessa exposição sobre os resultados clínicos e laboratoriais e sobre o sucesso do tratamento, a FIVETE foi incapaz de reduzir esse risco / A thematic research project to evaluate the health effects of acute/chronic exposure to ambient air in a large urban center was developed at the Air Pollution Laboratory in the Department of Pathology at the University of São Paulo School of Medicine. Within this project a specific research line was committed to the study of the effects of this exposure on female reproductive health. Evidence from epidemiological and experimental studies implied environmental factors as possible contributors to human infertility and poor obstetric outcome. However, very few studies evaluating a possible effect of exposure to particulate air pollution on female reproductive health have been conducted so far. Thus, the aim of the projects in my research line was to provide data that could show the possible effects of short-term preconceptional exposure to diesel exhaust particles and particulate air pollution on ovarian function, early embryo development and pregnancy outcome using experimental and epidemiological models. The objective of the first project was to examine the effects of two commercial media on the development of mouse ova fertilized in vitro to the blastocyst stage. One-cell embryos obtained from eight-week old superovulated mice were cultured in vitro up to the blastocyst stage in potassium-enriched simplex optimized medium (KSOM) or G1/G2 media. The percentage of zygotes that developed to the blastocyst stage 96 and 120 hours after insemination and that partially or completely hatched by day five of culture was significantly higher in the KSOM group. The mean number of inner cell mass (ICM) cells was 11.7 ± 4.0 and 9.2 ± 5.2 for zygotes cultured in KSOM and G1/G2 groups respectively, revealing a significantly higher cell number in the ICM of blastocysts derived from culture in KSOM medium. I concluded that commercially available KSOM medium is superior to sequential G1/G2 media for culturing one-cell embryos up to the blastocyst stage in the mouse IVF model. In the second project the objective was to evaluate the effects of short-term exposure to diesel exhaust particles on fertilization, embryo development, and cell lineage segregation in preimplantation blastocysts using the mouse IVF model. Intranasal instillation of distilled water (control group), native diesel exhaust particles (N-DEP group) or acid-extracted diesel exhaust particles (AE-DEP) once a day, for three days starting on the first day of gonadotrophin administration was performed on eight-week old female mice. Reproductive endpoints evaluated included ovarian response to superovulation, fertilization rate, embryo development, blastocyst and hatching rates, total cell count, and proportion of cell allocation to ICM and trophectoderm (TE), and ICM morphology. Ovarian response was not affected by the exposure protocol. A multivariate effect for exposure to NDEP and AE-DEP on blastocyst differential staining and ICM morphology but not on IVF or embryo development was found. Cell counts in ICM and ICM/TE ratios in blastocysts produced in the control group were significantly higher than in blastocysts produced in N-DEP and AE-DEP groups. The total cell count was similar among groups. The score that represents ICM morphology was significantly higher in the control group when compared to that found in N-DEP and AE-DEP groups. Based on these results this study suggests that short-term exposure to DEP may negatively affect the reproductive process by disrupting the lineage specification at the blastocyst stage. Finally, exposure to environmental toxins may be unavoidable during the preconceptional period in large urban centers and its effects are unknown. Thus, the purpose of the third project was to assess the potential effects of short-term exposure to particulate air pollution during the follicular phase on clinical, laboratory, and pregnancy outcomes for couples undergoing IVF/ET. Three hundred forty-eight patients undergoing their first IVF/ET cycle were evaluated in this retrospective cohort-matched casecontrolled single-center study. Exposure to ambient particulate matter (PM) during the follicular phase for each patient was estimated based on air pollution data (1997-2006) categorized in Q1-3 ( 56.72 g/m3) and Q4 (>56.72 g/m3) periods. From this group 177 women who became pregnant (cases) were compared with 354 who had conceived spontaneously (controls). Main outcome measures included response to gonadotrophins, number of oocytes retrieved, fertilization, cleavage, embryo quality, implantation, pregnancy, miscarriage, and live birth rates. No effects of follicular phase exposure to high levels of PM on clinical, laboratory, embryo transfer or treatment outcome were found in women undergoing IVF/ET. Women exposed to Q4 level PM during the follicular phase of the conception cycle had significantly higher risk of miscarriage, regardless of the method of conception (odds ratio, 2.58; 95% confidence interval: 1.63-4.07) when compared to women exposed to Q1-3 level PM. The risk of miscarriage increased 3% per unit increase in follicular phase PM average level (p=0.000). The results presented here provide evidence of a causal role for brief exposure to high levels of ambient PM during the preconceptional period in early pregnancy loss, regardless of the method of conception, with a 2.6-fold increase in risk of miscarriage. Despite the absence of effects of this exposure on clinical, laboratory, and treatment outcome, IVF/ET was unable to reduce this risk
495

Exercício físico e variabilidade da frequência cardíaca em diferentes locais e concentrações de poluição do ar em São Paulo, Brasil / Exercise and heart rate variability in different locations and concentrations of air pollution in São Paulo, Brazil

Renato Batista Paceli 08 December 2016 (has links)
Introdução: A Poluição do ar é um dos principais fatores de risco de morte no mundo. Estudos têm demonstrado que o exercício regular pode retardar o aparecimento de doenças. Por outro lado, o exercício físico aumenta o volume de ar inalado, resultando em uma maior deposição de poluentes nos pulmões. Objetivos: Avaliar a variabilidade da frequência cardíaca (VFC) durante a realização de exercícios físicos de moderado a intenso, em ambientes com diferentes concentrações de poluentes, em jovens saudáveis que praticam exercícios regularmente. Métodos: 58 indivíduos jovens e saudáveis foram submetidos a avaliação da VFC antes, durante e após a atividade física (7,5 km), em dias diferentes, em um circuito na via pública (CVP) e um circuito em um parque arborizado (CPq). O Polar RS800 foi o equipamento usado para registrar a frequência cardíaca (FC) e VFC, durante 15 minutos em repouso, durante os 45 minutos de corrida e durante os 15 minutos de recuperação. O MP2.5, temperatura (°C) e umidade relativa do ar, em porcentagem, foram monitorados durante as corridas. Resultados: Cinquenta e oito voluntários completaram o protocolo em ambos os circuitos. A idade média dos participantes foi de 19,2 (± 1,1) anos. A concentração média de MP2,5 foi 24,5 (± 12,9) ug/m3 no CPq e 74,8 (± 41,5) ug/m3 no CVP. A FC média observada durante o exercício foi menor no CVP (p = 0,0017). Correr no circuito CVP foi associado com uma maior redução no índice SDNN index em relação ao circuito CPq. Conclusão: A atividade física no CVP foi associada a um efeito adverso na FC e na VFC, acentuando o desequilíbrio autonômico / Introduction: Air pollution is one of major death risks factors on worldwide. Studies have shown that regular exercise can slow down the emergence of diseases. On the other hand, physical exercise increases the volume of air inhaled and, as a result, greater deposition of pollutants in the lungs. Aims: To evaluate the heart rate variability (HRV) during moderate to intense exercise, in environments with different concentrations of pollutants, in healthy young people who practice exercises regularly. Methods: 58 young, healthy individuals underwent HRV assessment before, during, and after physical activity (7.5 km), on different days, which consisted of running a circuit on a public street (PS) and running a circuit in a wooded park (PK). Polar RS800 equipment was used to record the heart rate (HR) and HRV, after 15 minutes at rest, after 45 minutes of running, and after 15 minutes of recovery. MP2.5, temperature (°C), and Percent relative air humidity were monitored during the races. Results: Fifty-eight volunteers completed the protocol in both circuits. Age of participants was 19.2 (± 1.1) years. The average concentration of MP2.5 was 24.5 (± 12.9) ug/m3 in the PK circuit and 74.8 (± 41.5) ug/m3 in the PS circuit. The HR average observed during the exercise was smallest in the PS circuit (p=0.0017). Running in the PS circuit was associated with a greater reduction in the SDNN index regarding PK circuit. Conclusion: Physical activity in PS was associated with an adverse effect in HR and HRV, accentuating the autonomic imbalance
496

Exposição à poluição de origem veicular, exercício físico e efeitos na proteína CC16 e na função renal em adultos jovens / Exposure to air pollution of vehicular origin, physical exercise and effects on CC16 protein and renal function in young adults

Aretusa Cardoso 19 December 2016 (has links)
Introdução: A Poluição do ar e a inatividade física são dois importantes fatores de risco para saúde. Ainda não são bem conhecidos o balanço sobre os efeitos na saúde da realização de exercícios em ambientes poluídos. Objetivos: Avaliar o impacto da realização de exercício físico em ambientes com diferentes concentrações de poluentes sobre a toxicidade pulmonar, em marcadores sanguíneos e na função renal. Métodos: 40 soldados do exército brasileiro, não fumantes, saudáveis, do sexo masculino e praticantes de corrida de rua regulares foram avaliados. Participaram de corridas de 7,5 km todas as manhãs, a uma velocidade de 10 km/h, por uma semana em um circuito dentro de um Parque Florestal (PQ) e uma semana em um circuito em Vias Públicas (VP). Foram coletadas amostras de sangue e urina antes e depois da corrida em dois dias de cada semana, sendo determinados marcadores sanguíneos, de toxicidade pulmonar e da função renal. Os níveis de MP2,5 foram registrados durante todos os dias das semanas no período em que foram feitas as avaliações. Resultados: A concentração de MP2,5 no circuito PQ foi de 24 ug/m3 (IQR: 8-39) e no circuito VP de 62 ug/m3 (IQR: 37-103), P < 0,001. Trinta e nove participantes concluíram. Idade: 19 ± 1 anos, Índice de Massa Corpórea: 23,5 ± 2,38 kg/m2, Frequência cardíaca repouso: 69,1 ± 10,4 bpm. A concentração de proteína CC16 urinária aumentou após as corridas em ambos circuitos, mas de forma mais acentuada no circuito PQ. Marcadores sanguíneos e de função renal se alteraram após a corrida, sem diferenças significativas entre os circuitos. Conclusão: A realização de atividade física esteve relacionada à inflamação sistêmica e alteração da função renal, sem diferença entre os circuitos em diferentes ambientes. A proteína CC16, marcador de toxicidade e alteração de permeabilidade pulmonar foi o único que se elevou, com maior magnitude, no circuito localizado no interior de um parque. / Introduction: The Air pollution and physical inactivity are two important risk factors for health. The assessment of the health effects of exercising in polluted environments are still not well known. To assess the impact of performing physical exercise in environments with different concentrations of pollutants on lung toxicity in blood markers and renal function. Methods: 40 soldiers from the Brazilian army, non-smoking, healthy male and regular street runners were evaluated. Participated in races of 7.5 km every morning at a speed of 10 km/h, for a week in a circuit within a Forest Park (PK) and a week in a circuit in Public Ways (PS). Blood and urine samples were collected before and after running over two days each week, with certain blood markers, pulmonary toxicity and renal function. The levels of PM2.5 were recorded during every day of the week in the period they were made evaluations. Results: The concentration of the PM2.5 circuit PK was 24 ug/m3 (IQR: 8-39) and PS circuit 62 ug/m3 (IQR: 37-103), P < 0.001. Thirty-nine participants completed. Age: 19 ± 1 years, body mass index: 23.5 ± 2.38 kg/m2, resting heart rate: 69.1 ± 10.4 bpm. The concentration of urinary protein CC16 increased after the races on both circuits, but more sharply in the PK circuit. Blood markers and markers of renal function are altered after the run, with no significant differences between the circuits. Conclusion: Physical activity was related to the variation of the markers indicating inflammation and changes in renal function, with no difference between the environments except for the marker of pulmonary toxicity that increased with greater magnitude in the PK circuit
497

A aplicabilidade de combinações seletivas de linhagens S. typhimurium na caracterização da mutagenicidade de amostras de ar / The applicability of selective combinations of strains S. typhimurium in the characterization of mutagenicity of airborne samples

Débora Kristina Magalhães Alves 03 October 2011 (has links)
O material particulado atmosferico é reconhecido como mutagênico. Embora vários compostos já tenham sido identificados nessa matriz, os mesmos não explicam o efeito observado na maioria dos bioensaios realizados. O ensaio de mutagenicidade Salmonella/microssoma tem sido amplamente utilizado para a avaliação de amostras atmosféricas o qual é muito sensível na detecção de vários tipos de mutágenos, pois é realizado com diferentes linhagens de Salmonella typhimurium na presença e ausência de ativação metabólica exógena. O principal objetivo deste trabalho foi verificar a aplicabilidade da utilização de combinações seletivas de linhagens S. typhimurium na caracterização da mutagenicidade de amostras de material particulado total de ar coletado em Limeira, uma cidade do interior do estado de São Paulo sob influência de intenso tráfego, emissões industriais e da agricultura, incluindo o plantio de cana de açúcar. Foram avaliados seis extratos orgânicos obtidos com diclorometano por ultrasonicação, utilizando o método Salmonella/microssoma em microssuspensão na presença e ausência de ativação metabólica (mistura S9) em experimentos de dose-resposta, com quantidade máxima de 50 &#181;g de material orgânico extraído (MOE) por placa. Os pares de linhagens utilizados foram: YG1041/TA98, para verificar a presença de nitrocompostos, como 1- nitropireno e/ou aminas aromáticas; YG5161/TA1538, altamente sensivel aos hidrocarbonetos policíclicos aromáticos (HPA) não substituídos como o benzo[a]pireno (BaP); e YG7108/TA1535, para a indicação de agentes alquilantes. Os resultados indicaram que os compostos que podem melhor explicar os efeitos observados são os nitro e/ou aminas aromáticas e não os HPA não substituídos como o BaP. O par YG7108/TA1535 forneceu respostas negativas para todas as amostras. As combinações seletivas de linhagens S. typhimurium (YG1041/TA98 e YG5161/TA1538) mostraram-se eficientes na caracterização da mutagenicidade de amostras de ar coletadas na cidade de Limeira, podendo ser utilizadas como uma importante ferramenta de auxílio do ensaio Salmonella/microssoma em microssuspensão em estudos de análises quimicas direcionadas pelo efeito biológico (ADEB). As potências mutagênicas observadas com a linhagem TA98 para a cidade de Limeira foram similares aquelas verificadas na Região Metropolitana de São Paulo. A comparação das respostas de mutagenicidade observadas para as amostras analisadas com o perfil de compostos puros, encontrados na literatura, não forneceu candidatos que podem representar a mistura. Mais estudos de mutagenicidade com compostos puros utilizando os pares de linhagens propostos (TA98/YG1041 e TA1538/YG5161) e análises quimicas de extratos fracionados são necessários para verificar se esta abordagem pode ser útil em estudos de ADEB, e consequentemente na descoberta de novos poluentes atmosféricos. / The atmospheric particulate matter is recognized as mutagenic. Although several compounds have been identified in this matrix, they do not explain the observed effect in most bioassays that have been performed. The Salmonella/microsome assay has been widely used for the evaluation of atmospheric samples, The assay is very sensitive in the detection of various types of mutagens, because it is performed with different strains of Salmonella typhimurium in the presence and absence of exogenous metabolic activation. The main objective of this work was to verify the applicability of selective combination of strains in the characterization of mutagenicity of total airborne particulate matter collected in Limeira, a São Paulo State city in a site influenced by heavy traffic, industrial and agricultural emissions, including sugar cane plantations. We tested six extracts obtained with methylene chloride by ultrasonication using the Salmonella/microsome microsuspension protocol in the presence and absence of rat liver S9 in dose response experiments, using 50 &#181;g of extractable organic matter (EOM) as a maximum dose per plate. The following pairs of strains were used: YG1041/TA98, to verify the presence of nitro-compounds, as 1-nitropyrene and/or aromatic amines; YG5161/TA1538, highly sensitive to non-substituted polycyclic aromatic hydrocarbons (PAHs) as benzo[a]pyrene (BaP); and YG7108/TA1535, for the indication of alkylating agents. The results indicated that the compounds that can better explain the observed effect are the nitro and/or aromatic amines and not nonsubstituted PAHs such as BaP. The pair YG7108/TA1535 provided negative responses for all the samples. Selective combinations of S. typhimurium strains (YG1041/TA98 and YG5161/TA1538) proved efficient in the characterization of mutagenicity of airborne samples collected in the city of Limeira and can be used as an important tool for the Salmonella/microsome microsuspension assay in effect directed chemical analysis (EDA) studies. The mutagenic potencies observed with TA98 strain for the city of Limeira were similar to those verified in the Metropolitan Region of São Paulo. The comparison of the observed mutagenicity responses for the samples analyzed with the profiles of pure compounds found in the literature did not provide any candidates that could alone represent the mixture. More mutagenicity studies with pure compounds using the proposed pair of strains (TA98/YG1041 and TA1538/YG5161) along with chemical analysis of fractioned extracts are needed to verify if this approach can be useful in EDA studies, and consequently in the discovery of new air priority pollutants.
498

Apport de la télédétection spatiale à haute résolution pour l’étude des cycles des eaux de surface et des matières particulaires en suspension le long du continuum bassin versant – océan côtier / Contribution of high resolution spatial remote sensing for the study of surface water cycles and suspended particulate matter along the watershed-coastal ocean continuum

Normandin, Cassandra 17 September 2019 (has links)
L’anticipation et l’adaptation de nos sociétés aux bouleversements résultants du changement climatique sont aujourd’hui des questions majeures guidant les activités humaines et l’action publique. Néanmoins, la prévision reste un défi essentiel en raison des fortes incertitudes existantes et il est primordial de continuer à progresser dans la compréhension des mécanismes à l’origine de ces bouleversements. Au sein du cycle hydrologique, le réservoir de surface (incluant les lacs, les rivières et les plaines d’inondation) occupe une place importante car il est l’une des principales ressources en eau des écosystèmes et des populations. Or, la dynamique des stocks d’eau de surface est toujours mal connue aux échelles régionale et globale, du fait de l’absence de mesures pluriannuelles d’extension et de hauteur d’eau des zones inondées, et de la prise en compte limitée de ces variables dans les modèles hydrologiques et hydrodynamiques. La télédétection spatiale offre désormais la possibilité d’effectuer un suivi des stocks d’eau de surface en utilisant la complémentarité entre l’imagerie multi-spectrale, permettant de cartographier les étendues inondées, et l’altimétrie radar fournissant des séries temporelles de hauteur d’eau des hydro-systèmes continentaux. L’objectif de ma thèse est de tirer le meilleur parti de la complémentarité entre les différents types d’observations spatiales pour évaluer les ressources en eau du réservoir de surface et mesurer la dynamique des transferts d’eau des continents aux océans, et son impact sur la zone côtière en utilisant les concentrations de matières en suspension comme traceur des masses d’eau. Depuis le milieu des années 1990, la multiplication des missions multi-spectrales à moyenne résolution (< 1 km de résolution spatiale) et des altimètres radars à haute précision (comprise entre 10 et 30 cm) permet de réaliser un suivi hebdomadaire à mensuel des volumes d’eau de surface dans les grands bassins fluviaux. / The anticipation and adaptation of our societies to the upheavals resulting from climate change are today major issues guiding human activities and public action. Nevertheless, the forecast remains a key challenge because of the strong uncertainties that exist and it is essential to continue to progress in understanding the mechanisms behind these upheavals. Within the hydrological cycle, the surface reservoir (including lakes, rivers and floodplains) occupies an important place as it is one of the main water resources of ecosystems and populations. However, the dynamics of surface water stocks are still poorly known at the regional and global scales, due to the absence of multi-year measures of extension and water depth of the flooded areas, and the limited consideration of these variables in hydrological and hydrodynamic models. Satellite remote sensing now offers the possibility of monitoring surface water stocks by using the complementarity between multispectral imagery, allowing to map flooded areas, and the radar altimetry providing time series of water depths of continental hydro systems. The aim of my thesis is to make the most of the complementarity between the different types of spatial observations to evaluate the water resources of the surface reservoir and to measure the dynamics of water transfers between land and ocean, and its impact on the coastal zone using suspended particulate matter as tracer of water bodies. Since the mid-1990s, the multiplication of multispectral missions with medium resolution (<1 km of spatial resolution) and high-precision radar altimeters (between 10 and 30 cm) makes it possible to carry out weekly-to-monthly monitoring of volumes surface water in large river basins.
499

Dynamique des matières en suspension en mer côtière : caractérisation, quantification et interactions sédiments/matière organique / Dynamics of suspended particulate matter in coastal waters : characterization, quantification and interactions sediments / organic matter

Chapalain, Marion 28 January 2019 (has links)
La connaissance de la dynamique des matières en suspension (MES) et des turbidités en milieu côtier est un élément clé pour comprendre les écosystèmes marins. Les processus de floculation/défloculation représentent des mécanismes essentiels contrôlant la dynamique des caractéristiques physiques des MES et, par conséquent, leur devenir dans l’environnement. Cette thèse a pour objectif de mieux comprendre la caractérisation des MES et leur variabilité de l’échelle tidale à l’échelle annuelle en mer côtière, en réponse aux différents forçages hydrodynamiques, hydrologiques et biologiques ayant lieu à l’interface entre estuaire et baie. À cette fin, des capteurs optiques et acoustiques ont été déployés in situ, lors de 6 campagnes en mer réalisées en 2016, en vue de caractériser et de quantifier les MES dans la colonne d’eau, à la sortie de l’embouchure de l’estuaire de Seine (France). Une analyse critique des mesures granulométriques issues du LISST-100X est proposée. Un travail de quantification des incertitudes de mesure associées à l’estimation de la concentration en MES a mis en avant le risqué lié à un rinçage insuffisant des filtres et a conduit à définir une masse minimum à filtrer, de l'ordre de 10 mg, quelle que soit la concentration. Ce travail a notamment permis de proposer une méthode d’estimation d’un volume optimal de filtration basée sur une mesure préalable de turbidité de référence. Les mesures à haute fréquence ont montré que la dynamique des caractéristiques physiques des MES en termes de concentration et de taille médiane sont contrôlées par le cycle advection-floculation-sédimentation-remise en suspension. Ces résultats ont permis de hiérarchiser les paramètres de contrôle des processus de floculation. La turbulence a été identifiée comme le principal paramètre de contrôle à l’échelle tidale et semi-lunaire, la taille médiane maximale des flocs étant inversement corrélée à l’intensité des courants. À l’échelle saisonnière, la variation des caractéristiques des MES (taille, densité, vitesse de chute) est liée à la variabilité du contenu en matière organique (MO), avec une floculation favorisée quand le taux de MO particulaire augmente. Ces flocs plus grands et moins denses sont également plus résistants à la fragmentation induite par cisaillement turbulent. Ces travaux ont également permis de discuter le concept de structuration fractale des flocs.La dynamique de la dimension fractale, déterminée en combinant des données in situ de concentration en MES et de distribution en classe de taille, peut traduire des variations de composition des MES, mais peut aussi résulter d'incertitudes de mesure associées aux instruments. Ces dernières sont discutées dans cette thèse. La variabilité saisonnière des caractéristiques des MES est plus prononcée au large que dans la zone sous influence de l’estuaire de Seine. À partir des observations ponctuelles en Baie de Seine et d’une série de mesure long terme dans la zone côtière belge acquise par le laboratoire RBINS, les méthodes acoustiques et optiques sont combinées. Ces dernières ont mis en avant une augmentation de la rétrodiffusion acoustique lorsque la densité moyenne des flocs diminue. / The knowledge of suspended particulate matter (SPM) and turbidity dynamics in coastal waters is essential for studying marine ecosystems. Flocculation/deflocculation processes are crucial mechanisms controlling the dynamics of SPM physical characteristics and thus, the fate of these SPM in the environment. This PhD thesis focuses on the SPM characteristics and their dynamics in coastal waters, from tidal to annual scales, in response to hydrodynamic, hydrological and biological forcing that take place at the interface between estuaries and coastal seas. To this end, optical and acoustic sensors were deployed in situ through 6 field campaigns in 2016, in order to characterize and quantify SPM in the water column, near the mouth of the Seine estuary (France). A critical analysis of LISST-100X measurements in coastal waters is presented. The quantification of uncertainties on SPM concentration measurements is investigated: it highlights the crucial effect of salt retention, and the need for a minimum mass to filter, around 10 mg. A method for estimating an optimal filtration volume based on a reference turbidity measurement is proposed. High frequency measurements show that the dynamics of SPM and median diameter are controlled by the advection-flocculationsedimentation-resuspension cycle.These results allow to classify the factors controlling flocculation processes. Turbulence is identified as the main factor at the semi-diurnal and semi-lunar tidal scales, as the maximum median size of flocs decreases when the tidal currents intensify.At the seasonal scale, the variation of SPM characteristics (size, density, settling velocity) is correlated to the variability of the organic matter (OM) content: in particular, flocculation is enhanced by an increase of the particular OM fraction. The resulting larger and lesser dense flocs are also more resistant to the fragmentation induced by shear. This work also investigates the fractal approach applied to flocs. The fractal dimension variability, calculated by combining in situ data of SPM concentration and particle size distribution, can be associated to variations of the SPM composition, but can also result from uncertainties linked to instrument limitations. The latter are discussed in this PhD thesis. The seasonal variability of SPM characteristics is more pronounced offshore than at the mouth of the Seine estuary. From short-term observations in the Seine Bay and from long-term series in the Belgian coastal zone provided by the RBINS, optical turbidity and acoustic backscatter measurements are combined. They highlight an increase of the acoustic backscatter intensity when mean floc density.
500

Predictive Modelling of Aquatic Ecosystems at Different Scales using Mass Balances and GIS

Gyllenhammar, Andreas January 2004 (has links)
<p>This thesis presents models applicable for aquatic ecosystems. Geographical Information Systems (GIS) form an important part of the thesis. The dynamic mass balance models focus on nutrient fluxes, biotic/abiotic interactions and operate on different temporal and spatial scales (site, local, regional and international). The relevance and role of scale in mass balance modelling is a focal point of the thesis.</p><p>A mesocosm experiment was used to construct a model to estimate the nutrient load of phosphorus and nitrogen from net cage fish farming (i.e., the site scale). The model was used to estimate what feeding conditions that are required for a sustainable aquaculture scenario, i.e., a zero nutrient load situation (a linkage between the site scale and the regional scale). </p><p>A dynamic model was constructed for suspended particulate matter (SPM) and sedimentation in coastal areas (i.e., the local scale) with different morphometric characteristics and distances to the Sea. The results demonstrate that the conditions in the Sea (the regional and international scale) are of fundamental importance, also for the most enclosed coastal areas.</p><p>A foodweb model for lakes was transformed and recalibrated for Baltic Sea conditions (i.e., the international scale). The model also includes a mass balance model for phosphorus and accounts for key environmental factors that regulate the presuppositions for production and biomasses of key functional groups of organisms. The potential use of the new model for setting fish quotas of cod was examined.</p><p>For the intermittent (i.e., regional) scale, topographically complex areas can be difficult to define and model. Therefore, an attempt was made to construct a waterscape subbasin identification program (WASUBI). The method was tested for the Finnish Archipelago Sea and the Okavango Delta in Botswana. A comparison to results from a semi-random delineation method showed that more enclosed basins was created with the WASUBI method.</p>

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