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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.
1

Development of an intelligent recommendation system to garment designers for designing new personalized products / Développement d'un système de recommandation intelligent orienté vers les créateurs de vêtements en vue de conception de nouveaux produits personnalisés

Dong, Min 04 April 2017 (has links)
Durant mes travaux en thèse, nous avons imaginé et poser les briques d'un système de recommandation intelligent (DIRS) orienté vers les créateurs de vêtements afin de les aider à créer des nouveaux produits personnalisés. Pour développer ce système, nous avons dans un premier temps identifié les composants clés du processus de création, puis nous avons créé un ensemble de bases de données pour collecter les données pertinentes. Dans un deuxième temps, nous avons acquis des données anthropométriques, recueilli la perception du concepteur à partir de ces mêmes morphotypes en utilisant un body scanner 3D et une procédure d'évaluation sensorielle. A la suite, une expérience instrumentale est conduite pour capturer les paramètres techniques des matières, nécessaires à leur représentation virtuelle en lien avec les morphotypes. Enfin, cinq expériences sensorielles sont réalisées pour capitaliser les connaissances des créateurs. Les données acquises servent à classer les morphotypes, à modéliser les relations entre morphotypes et facteurs de la création. A partir de ces modèles, nous avons mis en place une base de connaissances de la création mettant en œuvre une ontologie. Cette base de connaissances est mise à jour par un apprentissage dynamique au travers de nouveaux cas présentés en création. Ce système est utilisé au sein d’un nouveau processus de création. Ce processus peut s’effectuer autant de fois que nécessaire jusqu'à la satisfaction du créateur. Le système de recommandation proposé a été validé à l'aide de plusieurs cas réels. / In my PhD research project, we originally propose a Designer-oriented Intelligent Recommendation System (DIRS) for supporting the design of new personalized garment products. For developing this system, we first identify the key components of a garment design process, and then set up a number of relevant databases, from which each design scheme can be formed. Second, we acquire the anthropometric data and designer’s perception on body shapes by using a 3D body scanning system and a sensory evaluation procedure. Third, an instrumental experiment is conducted for measuring the technical parameters of fabrics, and five sensory experiments are carried out in order to acquire designers’ knowledge. The acquired data are used to classify body shapes and model the relations between human bodies and the design factors. From these models, we set up an ontology-based design knowledge base. This knowledge base can be updated by dynamically learning from new design cases. On this basis, we put forward the knowledge-based recommendation system. This system is used with a newly developed design process. This process can be performed repeatedly until the designer’s satisfaction. The proposed recommendation system has been validated through a number of successful real design cases.
2

Classification non-supervisée de morphologies 3D de corps humain pour la mise en œuvre de mannequins morphotypes adaptatifs / Clustering of 3D human bodies morphologies for the implementation of adaptive morphotypes mannequins

Hamad, Moez 24 June 2015 (has links)
Dans cette thèse, nous nous intéressons aux problématiques liées à la classification des formes 3D de corps humains. L'objectif de ce travail de thèse est de définir une méthodologie exhaustive pour obtenir des classes morphologiques caractérisant des formes humaines représentatives d'une population donnée et d'en extraire les morphotypes les plus significatifs. Une analyse géométrique globale de la forme du torse humain par des techniques de classification non-supervisée est mise en œuvre sur une base de données de 478 scans de femmes issues de la campagne de mensuration française réalisée en 2006 par l'IFTH. La description des scans 3D est réalisée avec un calcul des distributions des distances géodésiques à partir d'un ensemble de points anthropométriques positionnés sur la surface du torse 3D. Ce descripteur permet une comparaison quantitative des morphologies dans un monde tridimensionnel. Ces distributions géodésiques sont ensuite utilisées comme entrées pour les deux méthodes de classification non-supervisée que nous avons expérimentées. A l'issue de la classification, trois classes morphologiques, représentées par trois morphotypes, sont extraites dans la base de données. A partir de ces morphotypes, nous avons mis en place une méthode de conception des mannequins adaptatifs. Deux types d'ajustement du mannequin, en fonction de son volume et de sa stature, ont été développés afin de le contrôler à l’aide des individus inclus dans les classes obtenues ou à partir d'un système de taille industriel.Compte tenu de la diversité des disciplines telles que la morphologie humaine, les descripteurs de forme 3D, la classification non-supervisée et les mannequins morphotypes adaptatifs, cette thèse peut contribuer à de nombreuses recherches et problématiques industrielles du secteur de l'habillement. / In this PhD we investigate the problem of 3D human morphologies classification. The aim of this research is to define an exhaustive methodology to obtain a clustering of human morphology shapes representative of a population and to extract the most significant morphotype of each class. An overall geometric shape analysis of body surfaces coupled with technique of unsupervised clustering is implemented on a database of 478 scans of woman bodies from the French Sizing Survey (2006) conducted by IFTH.The description of the 3D scans is performed with a computation of the geodesic distributions based on anthropometrics feature points placed on the surface of human torso. This descriptor enables a quantitative comparison of the morphologies in 3D space. These geodesic distributions are then used as inputs for the two clustering methods we have achieved. After the classification, three morphological classes represented by three morphotypes are extracted from the database. Based on these morphotypes, we developed a design method of adaptive models. Two types of the mannequin adjustment, depending on its volume and height, have been developed to control it via included individuals in the obtained classes or via an industrial size system.
3

Survival, persistence, regrowth and morphotype variation of Listeria monocytogenes strains after exposure to first generation and second generation quaternary ammonium compounds in water

Schade, Stephen 08 August 2023 (has links) (PDF)
Listeria monocytogenes is one of the toughest challenges the food industry is facing today. While quaternary ammonium compounds (QAC) are typically applied at very high concentrations to kill L. monocytogenes, there are some factors that can cause its reduced efficacy in the food processing environment. Sublethal concentrations of stagnated QAC have been found both in processing plants and in waste waters released to the environment. Therefore, the purpose of this study was to investigate the ability of two L. monocytogenes strains, Bug600 (serotype 1/2a) and ScottA (serotype 4b) to persist in lethal and sublethal concentrations of first generation QAC (benzalkonium chloride, BAC) and second generation QAC (Ster-BAC), and if these strains would regrow when conditions had improved. Using BAC or Ster-BAC concentrations that mimic those found occurring in some environments, we determined L. monocytogenes survival, persistence, and recovery in high/low nutrient conditions, and also isolated two distinct morphotypes.
4

Late Cretaceous Sponge Borings - Indicators of Salinity and Sedimentation Drumheller, Alberta

Birchard, Mark Christopher 04 1900 (has links)
<p> A detailed study of sponge boring morphotypes within the molluscan fauna of Upper Cretaceous estuarine sediments near Drumheller, Alberta provides information relevant to the depositional environment. Problems with regard to utilizing Entobia as a paleoenvironmental indicator and as an indicator of salinity do not appear to be insurmountable.</p> <p> Distributions and characteristics of associated marine organisms (phoronid worms, gastropods and encrusting bryozoa) suggest that sponge colonies were affected by salinity and sedimentation. Boring networks in Ostrea glabra suggest that more than one species of sponge were present. Sponge distribution patterns, changes in papilla and chamber sizes and preferential occurrence of sponge borings on certain shell thicknesses provide good evidence for responses to salinity and sedimentation.</p> / Thesis / Bachelor of Science (BSc)
5

Habitats urbanisés : des trappes écologiques potentielles pour les oiseaux sauvages ? / Urban habitats : potential ecological traps for wild birds ?

Demeyrier, Virginie 14 December 2016 (has links)
L’urbanisation des milieux est un phénomène croissant induisant des changements importants des habitats naturels auxquels doit faire face la biodiversité. Ces modifications rapides et profondes de l’environnement vont créer de nouvelles conditions potentiellement contraignantes pour les individus. En effet, le cocktail de paramètres artificiels (par exemple : lumière, bruit, pollution chimique) couplé à une présence humaine ainsi qu’une ressource alimentaire souvent modifiée et/ou peu disponible peuvent contraindre la survie et la reproduction des espèces ayant colonisées les milieux urbains. Par ailleurs, les modifications profondes des habitats urbains sont susceptibles d’amener les individus à mal décrypter les indices communément utilisés dans les milieux non perturbés conduisant ces derniers à des réponses maladaptatives, et les populations associées jusqu’à des situations de trappe écologique. C’est dans ce contexte que s’inscrivent ces travaux de thèse chez la Mésange charbonnière, Parus major. Ces oiseaux ont été suivis en reproduction dans des nichoirs placés sur des sites présentant des niveaux d’artificialisation variables, que nous avons quantifiés, au sein de la ville de Montpellier. La taille de la cavité de reproduction a été également manipulée expérimentalement (manipulation de l’indice). Nous avons pu observer une préférence pour les cavités les plus grandes ainsi qu’un investissement dans la ponte plus important mais un nombre de jeunes envolés plus faible relativement aux cavités de taille plus petite. Cette réponse maladaptative associée à la taille de la cavité nous a amené à nous questionner plus précisément sur le rôle des ressources alimentaires associées au milieu urbain et sur le potentiel adaptatif de nos oiseaux urbains. Les expériences menées, en lien avec les ressources alimentaires, ont mis en évidence qu’effectivement la ressource est un facteur clé contraignant la reproduction des mésanges urbaines. Par ailleurs, grâce à un dispositif forestier historique situé à une vingtaine de kilomètres de notre site d’étude urbain, nous avons testé la présence de deux écotypes urbains et ruraux. Nous avons pu mettre en évidence des différences de morphologies entre habitats, sans détecter pour autant de différence de condition physique. Pourtant, à l’échelle plus fine du gradient d’urbanisation, ces différences apparaissent. De plus, l’étude des personnalités des oiseaux a mis également en évidence un différentiel de personnalités inter-habitat mais aussi intra-habitat, qui soulève encore à l’heure actuelle des questions d’adaptation autour de ces phénotypes particuliers. Ces travaux soulignent la complexité des questions écologiques et évolutives dans les environnements fortement perturbés que sont les milieux urbains et nécessitent de continuer à approfondir nos connaissances afin d’apporter au mieux des solutions pour la gestion de la biodiversité urbaine. / Urbanization is an increasing phenomenon inducing dramatic modifications of natural habitats facing biodiversity. These rapid and drastic environmental changes create new conditions, potentially constraining individuals. Indeed, artificial parameters, such as light, noise and chemical pollution, coupled with human presence and food resources which are often modified and less available, should constrain survival and reproduction of urban species. Moreover, urban habitat changes could lead individuals to misinterpret natural environmental cues, inducing maladaptive responses and populations into an ecological trap. In this context, we developed this research project on great tits, Parus major to improve our understanding of avian adaptation in cities. We monitored great tit reproduction breeding in nest-boxes within an urbanization gradient, which has been quantified, in the city of Montpellier. We experimentally manipulated nesting-cavity size using different types of nest-boxes. We found that the birds preferred the largest artificial cavities for breeding when they could choose between small, medium-sized and large cavities. Individuals from the largest cavities also invested more in egg production, yet had a lower fledging success than those from medium-sized cavities. These results are an experimental demonstration of a trap mechanism in free-living animals. To test our hypothesis that food resources are an environmental key factor limiting reproductive performance in our urban great tit population, we conducted experiments modulating constraints on food resources. The conclusion of these experiments is that food is a limiting factor for reproduction. In addition, in a local adaptation framework, we examined if urban great tits possess particular phenotypic traits that differ from great tits that live in more natural conditions. We found that urban and rural great tits expressed differences in morphology and personality profiles both at the inter-habitat and intra-habitat level. Additional studies will be required to better understand the underlying mechanisms that link phenotypic and reproductive performance in individuals that face rapid environmental change and increased urbanization, also to improve biodiversity conservation programs in these environments.
6

Caracterização estrutural do sistema reprodutor masculino e do hepatotâncreas dos diferentes morfotipos de Macrobrachium amazonicum /

Papa, Luciene Patrici. January 2007 (has links)
Orientador: Irene Bastos Franceschini Vicentini / Banca: Elizabeth Romagosa / Banca: Maíra Aparecida Stefanini / Banca: Bruno Cezar Stefanini / Banca: Silvana Martinez Baraldi Artoni / Resumo: A carcinicultura de água doce tem sido reconhecida como uma forma para a produção de crustáceos com baixo impacto ambiental. O camarão Macrobrachium amazonicum apresenta grande potencial para a aqüicultura. Nos últimos anos, vários trabalhos sobre a biologia dessa espécie têm sido realizados com o intuito de desenvolver um pacote tecnológico sustentável para o cultivo de Macrobrachium amazonicum. Esse trabalho teve como objetivo descrever a estrutura microscópica do sistema reprodutor masculino (testículos, ductos deferentes e glândulas androgênicas) e do hepatopâncreas dos diferentes morfotipos de Macrobrachium amazonicum. Para tanto 40 machos adultos foram divididos em quatro grupos morfotípicos, sendo denominados de TC (Translucent Claw), CC (Cinnamon Claw), GC1 (Green Claw 1) e GC2 (Green Claw 2). Os animais foram pesados e foram realizadas medições do comprimento corpóreo total e do comprimento do segundo quelípodo direito. Após, os animais foram mortos e tiveram seus testículos, ductos deferentes, glândulas androgênicas e hepatopâncreas retirados e submetidos à rotina histológica de historesina. Foi observada a diferenciação de três morfotipos, segundo as análises realizadas, sendo eles, TC (Translucent Claw), CC (Cinnamon Claw) e GC(Green Claw). Entretanto estudos enfatizando o comportamento reprodutivo, assim como, a histoquímica e a ultraestrutura do sistema reprodutivo e do hepatopâncreas, durante a diferenciação morfotípica devem ser realizados para que se possa conhecer a dinâmica morfotípica dos machos adultos de Macrobrachium amazonicum. / Abstract: The culture of the freshwater prawns has been recognized as a way to produce crustaceans with a low enviromental impact. Macrobrachium amazonicum is the South American prawn with the greatest potencial for aquaculture. Since 2001 a multidisciplinary and multi-institutional research program has been developed technology for Macrobrachium amazonicum culture in Brazil. Thus, this study attemped to characterize the light microscope structures of the reproductive system (testes, vas deferens and androgenic gland) and the hepatopancreas of the differents morphotypes of the Macrobrachium amazonium. Specimens were collected and classified in four morphotypical groups: TC, CC, GC1 and GC2. The specimens were weight, and the total length and the cheliped length were measured. Then the testes, vas deferens, androgenic gland and hepatopancreas were fixed for histological routine of historesin. Three distinct morphological morphotypes were identified, TC (Translucent Claw), CC (Cinnamon Claw) and GC (Green Claw) morphotypes. Therefore more studies concerning to the reproductive behavior and the histochemical and ultrastrucutral studies need to be accomplished to elucitade the morphotypic differentiation of the male adults of Macrobrachium amazonicum. / Doutor
7

Caracterização estrutural do sistema reprodutor masculino e do hepatotâncreas dos diferentes morfotipos de Macrobrachium amazonicum

Papa, Luciene Patrici [UNESP] 20 August 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-20Bitstream added on 2014-06-13T20:00:47Z : No. of bitstreams: 1 papa_lp_dr_jabo.pdf: 7799287 bytes, checksum: 948c753d894690d4395d036a7f4ea60f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A carcinicultura de água doce tem sido reconhecida como uma forma para a produção de crustáceos com baixo impacto ambiental. O camarão Macrobrachium amazonicum apresenta grande potencial para a aqüicultura. Nos últimos anos, vários trabalhos sobre a biologia dessa espécie têm sido realizados com o intuito de desenvolver um pacote tecnológico sustentável para o cultivo de Macrobrachium amazonicum. Esse trabalho teve como objetivo descrever a estrutura microscópica do sistema reprodutor masculino (testículos, ductos deferentes e glândulas androgênicas) e do hepatopâncreas dos diferentes morfotipos de Macrobrachium amazonicum. Para tanto 40 machos adultos foram divididos em quatro grupos morfotípicos, sendo denominados de TC (Translucent Claw), CC (Cinnamon Claw), GC1 (Green Claw 1) e GC2 (Green Claw 2). Os animais foram pesados e foram realizadas medições do comprimento corpóreo total e do comprimento do segundo quelípodo direito. Após, os animais foram mortos e tiveram seus testículos, ductos deferentes, glândulas androgênicas e hepatopâncreas retirados e submetidos à rotina histológica de historesina. Foi observada a diferenciação de três morfotipos, segundo as análises realizadas, sendo eles, TC (Translucent Claw), CC (Cinnamon Claw) e GC(Green Claw). Entretanto estudos enfatizando o comportamento reprodutivo, assim como, a histoquímica e a ultraestrutura do sistema reprodutivo e do hepatopâncreas, durante a diferenciação morfotípica devem ser realizados para que se possa conhecer a dinâmica morfotípica dos machos adultos de Macrobrachium amazonicum. / The culture of the freshwater prawns has been recognized as a way to produce crustaceans with a low enviromental impact. Macrobrachium amazonicum is the South American prawn with the greatest potencial for aquaculture. Since 2001 a multidisciplinary and multi-institutional research program has been developed technology for Macrobrachium amazonicum culture in Brazil. Thus, this study attemped to characterize the light microscope structures of the reproductive system (testes, vas deferens and androgenic gland) and the hepatopancreas of the differents morphotypes of the Macrobrachium amazonium. Specimens were collected and classified in four morphotypical groups: TC, CC, GC1 and GC2. The specimens were weight, and the total length and the cheliped length were measured. Then the testes, vas deferens, androgenic gland and hepatopancreas were fixed for histological routine of historesin. Three distinct morphological morphotypes were identified, TC (Translucent Claw), CC (Cinnamon Claw) and GC (Green Claw) morphotypes. Therefore more studies concerning to the reproductive behavior and the histochemical and ultrastrucutral studies need to be accomplished to elucitade the morphotypic differentiation of the male adults of Macrobrachium amazonicum.
8

Mikorizės morfotipai paprastosios pušies želdiniuose / The mycorrhizal morphotypes of Scots pine seedlings in response to different site

Kulešo, Anton 14 January 2009 (has links)
Mokslinį tiriamąjį darbą “Mikorizės morfotipai paprastosios pušies želdiniuose” sudaro 52 puslapiai, iš jų 10 lentelių, 26 paveikslų, literatūros sąraše 72 šaltiniai. Išanalizuotas paprastosios pušies Labanoro provenencijos sodmenų vystymosi ir adaptyvumo ypatumai lauko daigyne ir želdiniuose. Įvertinta atskirų daigyno substratų (pušyno, ąžuolyno pakločių) įtaka sėjinukų (2+0) vystymuisi, adaptyvumui ir mikorizės išplitimui. Nustatyti minėtos provenencijos sodinukų (2+1) reakcijos į naujas augimo sąlygas atskirose želdavietėse (poligone, miško kirtavietėje, žemės ūkio naudmenose) ypatumai. Pateikti mikorizės kiekybinės ir kokybinės sudėties skirtumai atskiruose daigyno substratuose ir tirtose želdavietėse. Palygintos tradiciniu (morfotipavimo) ir molekuliniais (PCR-RFLP, sekvenavimas) metodais nustatytos mikorizės grybų rūšys. / The study from the research “The mycorrhizal morphotypes of Scots pine seedlings in response to different site” amounts to 52 pages, 10 tables, 26 figures and 72 refrences. The peculiarities of development and adaptivity of Scots pine seedlings from Labanoras provenance in bare-roots nursery and different site were analyzed. We hypothesized that soil with forest litter amendment would affect ectomycorrhizal community structure and growth and productivity characteristics of Scots pine seedlings in bare-roots nursery and in response to different site. In our experimental system, a layer of pine or oak litter was placed on the surface of the nursery bed soil in order to mimic natural litter cover. The influence of different nursery substrata (oak and pine litter) on development, adaptivity and mycorrhizal spread of seedlings (2+0) has been assessed. The peculiarities of seedlings (2+1) of mentioned provenance in response to new growth conditions in different site were found. The differences of qualitative and quantitative composition in nursery substrata and different site were investigated. Mycorrhizal fungi species were assessed by morphotyping and molecular methods (PCR-RFLP, sequence) identification. We have preliminary evidenced that changes to the supply of organic matter through litter manipulation may have wide-reaching effects on soil physical properties and soil chemistry and thus influence growth and survival Scots pine seedlings and their mycorrhizal communities... [to full text]
9

Reguladores da variação temporal e espacial da comunidade bacteriana em lagoa rasa subtropical

Kist, Danieli Ledur January 2012 (has links)
O bacterioplâncton é um dos grupos de organismos responsáveis pela remineralização de nutrientes em ecossistemas aquáticos, bem como produtor de biomassa através da alça microbiana. Compreender a dinâmica dessa comunidade em função da variação térmica, disponibilidade de recursos e pressão de predação pode fornecer elementos que auxiliem no gerenciamento dos recursos hídricos, através da aplicação direta desse conhecimento ou como subsídios na interpretação do resultado de simulações através de modelos ecológicos. Este trabalho teve como objetivo verificar a existência de heterogeneidade espacial e temporal na estrutura da comunidade bacteriana, densidade, biomassa e riqueza de morfotipos, na Lagoa Mangueira, bem como identificar as variáveis limnológicas que direcionam esses padrões. Foi evidenciada presença de heterogeneidade temporal, sazonal, e espacial do bacterioplâncton associada a dinâmica das variáveis limnológicas. A temperatura e a disponibilidade de nutrientes foram as principais variáveis que regularam as comunidades planctônicas, biomassa algal, bacterioplâncton e zooplâncton. Observou-se controle lateral, competição por nutrientes, entre as comunidades produtoras. O controle descendente, predação, mostrou ter importante efeito sobre o bacterioplâncton, mais especificamente sobre o morfotipo coccus, durante o verão e o inverno, sendo essa comunidade controlada de forma ascendente durante o outono e a primavera, principalmente por nitrogênio. Durante o inverno, a comunidade bacteriana apresentou significativa redução de densidade e biomassa, sendo que essa resposta pode estar relacionada às baixas temperaturas da água. A forma coccus foi o principal morfotipo produtor de biomassa e de maior densidade na lagoa. Importante heterogeneidade espacial foi observada na Lagoa Mangueira para as variáveis abióticas, visto que as regiões norte e sul apresentaram a maior diferenciação espacial, influenciada pela dimensão da lagoa. Fósforo total e carbono orgânico total regularam a comunidade bacteriana no norte da lagoa, especialmente os morfotipos coccus, curved e outros. Entre as zonas da lagoa, a margem oeste e leste foram as mais distintas em função da disponibilidade de nutrientes, destacando-se o carbono inorgânico total. A densidade bacteriana foi maior durante o verão, outono e inverno na região pelágica e durante a primavera na margem oeste da lagoa. A comunidade fitoplanctônica apresentou uma distribuição espacial caracterizada por maiores densidades nas regiões norte e centro da lagoa e na zona pelágica. O fósforo foi a principal variável limitante para as comunidades produtoras, fitoplâncton e bacterioplâncton, sendo o controle ascendente o principal regulador dessas comunidades, visto que o controle descendente não foi observado. Quanto à dinâmica dos organismos planctônicos e das variáveis limnológicas associados ao perfil de profundidade, a Lagoa Mangueira não apresentou estratificação das variáveis e consequentemente das comunidades planctônicas, resultado relacionado a uma possível característica de mistura completa da massa d’água, mesmo com ventos de baixa intensidade. As comunidades planctônicas apresentaram maior densidade durante o inverno, direcionadas pela maior disponibilidade de nitrogênio e fósforo. / Bacterioplankton is one of the groups of organisms responsible for the remineralization of nutrients in aquatic ecosystems, as well as a producer of biomass through the microbial loop. Understanding the dynamics of this community due to the thermal variation, resource availability and predation pressure may provide data to assist in the management of water resources through the application of that knowledge or direct subsidies in the interpretation of the results of simulations using ecological models. This work aimed to verify the existence of spatial and temporal heterogeneity in bacterial community structure, density, biomass and richness of morphotypes in Mangueira Lake, as well as identify the limnological variables that drive these patterns. We evidenced the presence of temporal heterogeneity, seasonal and spatial dynamics of bacterioplankton associated with limnological characteristics. The temperature and nutrient availability were the main variables that regulated the planktonic communities, algal biomass, bacterioplankton and zooplankton. There was lateral control, competition for nutrients, between the producing communities. The top down control, predation, was shown to have important effects on the bacterioplankton, more specifically on the coccus morphotype during the summer and winter, and this controlled community in bottom up controled during the fall and spring, mainly nitrogen. During the winter, the community had a significant reduction in bacterial density and biomass, and this response may be related to low water temperatures. Morphotype coccus was the main producing biomass and higher density in the lake. Important spatial heterogeneity was observed at Mangueira Lake for the abiotic variables, whereas the northern and southern regions had the highest spatial differentiation, influenced by the size of the lake. Total phosphorus and total organic carbon regulated bacterial community in the north of the lagoon, especially coccus morphotypes, curved and ‘others’. Among the areas of the lake, the west border and east were the most different depending on the availability of nutrients, especially if the total inorganic carbon. The bacterial density was higher during the summer, autumn and winter in the pelagic region and during the spring on the west border of the lake. The phytoplankton community showed a spatial distribution characterized by higher densities in the north and center of the lake and the pelagic zone. Phosphorus was the main variable limiting communities producing, phytoplankton and bacterioplankton, and bottom up control of these communities, since the top down control was not observed. Considering the dynamics of planktonic organisms and limnological variables associated with the depth profile, the Mangueira Lake did not show stratification of variables and consequently the planktonic communities, the result can be related to a characteristic of complete mixing of water mass, even with low wind intensity. The planktonic communities showed higher densities during the winter, driven by increased availability of nitrogen and phosphorus.
10

Reguladores da variação temporal e espacial da comunidade bacteriana em lagoa rasa subtropical

Kist, Danieli Ledur January 2012 (has links)
O bacterioplâncton é um dos grupos de organismos responsáveis pela remineralização de nutrientes em ecossistemas aquáticos, bem como produtor de biomassa através da alça microbiana. Compreender a dinâmica dessa comunidade em função da variação térmica, disponibilidade de recursos e pressão de predação pode fornecer elementos que auxiliem no gerenciamento dos recursos hídricos, através da aplicação direta desse conhecimento ou como subsídios na interpretação do resultado de simulações através de modelos ecológicos. Este trabalho teve como objetivo verificar a existência de heterogeneidade espacial e temporal na estrutura da comunidade bacteriana, densidade, biomassa e riqueza de morfotipos, na Lagoa Mangueira, bem como identificar as variáveis limnológicas que direcionam esses padrões. Foi evidenciada presença de heterogeneidade temporal, sazonal, e espacial do bacterioplâncton associada a dinâmica das variáveis limnológicas. A temperatura e a disponibilidade de nutrientes foram as principais variáveis que regularam as comunidades planctônicas, biomassa algal, bacterioplâncton e zooplâncton. Observou-se controle lateral, competição por nutrientes, entre as comunidades produtoras. O controle descendente, predação, mostrou ter importante efeito sobre o bacterioplâncton, mais especificamente sobre o morfotipo coccus, durante o verão e o inverno, sendo essa comunidade controlada de forma ascendente durante o outono e a primavera, principalmente por nitrogênio. Durante o inverno, a comunidade bacteriana apresentou significativa redução de densidade e biomassa, sendo que essa resposta pode estar relacionada às baixas temperaturas da água. A forma coccus foi o principal morfotipo produtor de biomassa e de maior densidade na lagoa. Importante heterogeneidade espacial foi observada na Lagoa Mangueira para as variáveis abióticas, visto que as regiões norte e sul apresentaram a maior diferenciação espacial, influenciada pela dimensão da lagoa. Fósforo total e carbono orgânico total regularam a comunidade bacteriana no norte da lagoa, especialmente os morfotipos coccus, curved e outros. Entre as zonas da lagoa, a margem oeste e leste foram as mais distintas em função da disponibilidade de nutrientes, destacando-se o carbono inorgânico total. A densidade bacteriana foi maior durante o verão, outono e inverno na região pelágica e durante a primavera na margem oeste da lagoa. A comunidade fitoplanctônica apresentou uma distribuição espacial caracterizada por maiores densidades nas regiões norte e centro da lagoa e na zona pelágica. O fósforo foi a principal variável limitante para as comunidades produtoras, fitoplâncton e bacterioplâncton, sendo o controle ascendente o principal regulador dessas comunidades, visto que o controle descendente não foi observado. Quanto à dinâmica dos organismos planctônicos e das variáveis limnológicas associados ao perfil de profundidade, a Lagoa Mangueira não apresentou estratificação das variáveis e consequentemente das comunidades planctônicas, resultado relacionado a uma possível característica de mistura completa da massa d’água, mesmo com ventos de baixa intensidade. As comunidades planctônicas apresentaram maior densidade durante o inverno, direcionadas pela maior disponibilidade de nitrogênio e fósforo. / Bacterioplankton is one of the groups of organisms responsible for the remineralization of nutrients in aquatic ecosystems, as well as a producer of biomass through the microbial loop. Understanding the dynamics of this community due to the thermal variation, resource availability and predation pressure may provide data to assist in the management of water resources through the application of that knowledge or direct subsidies in the interpretation of the results of simulations using ecological models. This work aimed to verify the existence of spatial and temporal heterogeneity in bacterial community structure, density, biomass and richness of morphotypes in Mangueira Lake, as well as identify the limnological variables that drive these patterns. We evidenced the presence of temporal heterogeneity, seasonal and spatial dynamics of bacterioplankton associated with limnological characteristics. The temperature and nutrient availability were the main variables that regulated the planktonic communities, algal biomass, bacterioplankton and zooplankton. There was lateral control, competition for nutrients, between the producing communities. The top down control, predation, was shown to have important effects on the bacterioplankton, more specifically on the coccus morphotype during the summer and winter, and this controlled community in bottom up controled during the fall and spring, mainly nitrogen. During the winter, the community had a significant reduction in bacterial density and biomass, and this response may be related to low water temperatures. Morphotype coccus was the main producing biomass and higher density in the lake. Important spatial heterogeneity was observed at Mangueira Lake for the abiotic variables, whereas the northern and southern regions had the highest spatial differentiation, influenced by the size of the lake. Total phosphorus and total organic carbon regulated bacterial community in the north of the lagoon, especially coccus morphotypes, curved and ‘others’. Among the areas of the lake, the west border and east were the most different depending on the availability of nutrients, especially if the total inorganic carbon. The bacterial density was higher during the summer, autumn and winter in the pelagic region and during the spring on the west border of the lake. The phytoplankton community showed a spatial distribution characterized by higher densities in the north and center of the lake and the pelagic zone. Phosphorus was the main variable limiting communities producing, phytoplankton and bacterioplankton, and bottom up control of these communities, since the top down control was not observed. Considering the dynamics of planktonic organisms and limnological variables associated with the depth profile, the Mangueira Lake did not show stratification of variables and consequently the planktonic communities, the result can be related to a characteristic of complete mixing of water mass, even with low wind intensity. The planktonic communities showed higher densities during the winter, driven by increased availability of nitrogen and phosphorus.

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