This thesis is done in the framework of the ILC. The determination of the electroweak couplings of the top quark, is one of the tasks at the ILC. The thesis is dedicated to the measurement of the Forward-backward asymmetry in top quark pairs, at 500 GeV, using two beam polarization configurations, in the fully hadronic decay channel. The top quark almost exclusively decays to a b quark and a W boson. The 6 jet final state is analyzed using full detector simulation. Two jets with highest b-tag are taken as b jets and the remaining four jets are used to reconstruct the W s. The identification of the top and anti-top quarks is done by using the vertex charge of the b quark. Precisions on the production cross sections are also calculated. This thesis also includes a chapter on the optimization of the Si-W Electromagnetic calorimeter of the International Large Detector (ILD), one of the two detectors at the ILC. The ECAL of ILD, will consist of alternate layers of Silicon and Tungsten, where Silicon layers are active layers, while Tungsten is passive material. The Silicon layers are divided into wafers, surrounded by guard rings, to avoid the leakage currents. The analysis is focused to optimize the guard ring size. The thesis is divided into 6 chapters. The first chapter gives a brief over view of the Standard Model. The second chapter is dedicated to the theoretical aspects of the top quark physics at the ILC. A detailed description of the ILD and its sub-detectors is given in the 3rd chapter. The 4th chapter presents the studies of the optimization of Si-W ECAL guard ring size. The 5th chapter contains the details of analysis of tt production at ILC, and measurement of the AFBt . The last chapter contains the summary of the results.

Temporal pulse shaping based on integrated Bragg gratings is investigated in this work to achieve arbitrary output waveforms. The grating structure is simulated based on the sidewall-etching geometry in an AlGaAs platform. The inverse scattering employin the Gel'fan-Levithan-Marchenko theorem and the layer peeling method provides a tool to determine grating structures from a desired spectral reflection response. Simulations of pulse shaping considered flat-top and triangular pulses as well as one-to-one and one-to-many pulse shaping. The suggested grating profiles revealed a compromise between performance and grating length. The integrated grating, a few hundred microns in length, could generate flat-top pulses with pulse durations as short as 500 fs with rise/fall times of 200 fs; the results are comparable to previous work in free-space optics and fiber optics. The theories and the devised algorithms could serve as a design station for advanced grating devices for, but not restricted to, optical pulse shaping.

Temporal pulse shaping based on integrated Bragg gratings is investigated in this work to achieve arbitrary output waveforms. The grating structure is simulated based on the sidewall-etching geometry in an AlGaAs platform. The inverse scattering employin the Gel'fan-Levithan-Marchenko theorem and the layer peeling method provides a tool to determine grating structures from a desired spectral reflection response. Simulations of pulse shaping considered flat-top and triangular pulses as well as one-to-one and one-to-many pulse shaping. The suggested grating profiles revealed a compromise between performance and grating length. The integrated grating, a few hundred microns in length, could generate flat-top pulses with pulse durations as short as 500 fs with rise/fall times of 200 fs; the results are comparable to previous work in free-space optics and fiber optics. The theories and the devised algorithms could serve as a design station for advanced grating devices for, but not restricted to, optical pulse shaping.

This dissertation investigates how executives engage in information technology projects and how organizational control of IT projects forms and evolves over time. It contains an in-depth account of a large, multi-year IT project in a financial company. The story of the “New Deposit System” project provides insights into the dynamics of IT projects in organizations and the challenges facing executives engaging in the governance of these complex undertakings. Several characteristics of IT projects, such as their abstract nature, technological complexity and non-repetitiveness, render several of the manager’s trusted forms of control impracticable. Even the ideal of “strong top management support” is found to be problematic: it is an extraordinary measure unlikely to translate well into regular organizational practice. What we find instead are actors in search of means and ways to exercise influence. We find control to be reciprocal and dynamic, influenced by the organization and its history, by the principles and practices of corporate IT management and by the values and norms of the IT profession. In this environment, selection of key people, evolving trust, other people’s assessments and the construction and reshaping of a project image become important parts of the managerial repertoire for IT project governance. / Diss. Stockholm : Handelshögskolan, 2002

Mathematical modelling problems are embedded in written, representational, and graphic text. For students to actively engage in the mathematical-modelling process, they require literacy. Of critical importance is the comprehension of the problems' text information, data, and goals. This design-research study investigated the application of top-level structuring; a literary, organisational, structuring strategy, to mathematical-modelling problems. The research documents how students' mathematical modelling was changed when two classes of Year 4 students were shown, through a series of lessons, how to apply top-level structure to two scientifically-based, mathematical-modelling problems. The methodology used a design-based research approach, which included five phases. During Phase One, consultations took place with the principal and participant teachers. As well, information on student numeracy and literacy skills was gathered from the Queensland Year 3 'Aspects of Numeracy' and 'Aspects of Literacy' tests. Phase Two was the initial implementation of top-level structure with one class of students. In Phase Three, the first mathematical-modelling problem was implemented with the two Year 4 classes. Data was collected through video and audio taping, student work samples, teacher and researcher observations, and student presentations. During Phase Four, the top-level structure strategy was implemented with the second Year 4 class. In Phase Five, the second mathematical-modelling problem was investigated by both classes, and data was again collected through video and audio taping, student work samples, teacher and researcher observations, and student presentations. The key finding was that top-level structure had a positive impact on students' mathematical modelling. Students were more focussed on mathematising, acquired key mathematical knowledge, and used high-level, mathematically-based peer questioning and responses after top-level structure instruction. This research is timely and pertinent to the needs of mathematics education today because of its recognition of the need for mathematical literacy. It reflects international concerns on the need for more research in problem solving. It is applicable to real-world problem solving because mathematical-modelling problems are focussed in real-world situations. Finally, it investigates the role literacy plays in the problem-solving process.

Made available in DSpace on 2015-03-26T13:28:36Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1715165 bytes, checksum: ba96ef5c3249cefde8551b95cd57d667 (MD5) Previous issue date: 2014-11-25 / With developments in recent years, methods for bathymetric surveys using acoustic sensors (echo sounders) and signals transmitted by satellite navigation receivers, it becomes possible to describe the submerged same level of detail which is embossed with the surface relief describes terrestrial. A graphical representation of the underwater relief occurs from Digital Elevation Models (DEMs) generated by interpolating seeking, from measurements, predict the depth at unsampled locations. The geometrical information taken from bathymetric surveys, the volume of liquid water or mud present, for example in a reservoir, is the most relevant. This study sought to determine the products generated by single beam bathymetric survey, as well as the methods of kriging interpolation and Topo to Raster. The study areas were a box of decanting of the water treatment plant and a dam lake of Furnas, where surveys were conducted, with total station and bathymetric surveys, with a single beam echo sounder which operates at frequencies 33 kHz and 210 kHz . In the settling box, first bathymetric survey was conducted (Lbat 1). Then be emptied and cleaned the box and before filling it again, surveying, (Ltop) was performed with total station. Immediately after filling, without water and mud decanted, another bathymetric survey (Lbat 2) was performed. To survey the dam lake of Furnas, held automated bathymetric survey, ie, using the GNSS technology for positioning. First, the data from the survey, we evaluated the methods of kriging interpolation and Topo to Raster in the DEM generation of the settling box. The conclusion was that the interpolator Top to Raster conditioning showed remarkable deformations at the edges and in the center of the study area and should be discarded. The next stage of this work was to evaluate the accuracy of DEMs generated by applying kriging on data from single beam bathymetric survey, Lbat 2, using the frequencies of 33 kHz and 210 kHz. Possession of DEMs were calculated discrepancies between information from them and points of surveying. The results showed an accuracy of about 5 cm in mean depths of 3.21 m, and that as the surveys were conducted after cleaning the box, with clean water, there was no significant difference in the accuracy of DEMs generated with depths raised to the frequencies 33 kHz and 210 kHz. Then the DEMs were generated by kriging for the first bathymetric survey, Lbat 1, when solid waste resulting from the settling process still existed. Volumes were calculated and compared to evaluate the frequency of 33 kHz echo sounder to determine the volume of mud in the box. After analyzing the results, it was found that using only the first bathymetric survey, with the frequencies 33 kHz and 210 kHz, there was detected 186 m3 of sludge, in a total volume of 799 m3 of water and mud which, with the clean water the volume is determined by accurate bathymetry, showing discrepancy of 0.63% for the frequency of 210 kHz and 0.12% for the frequency of 33 kHz. To survey the lake of Furnas DEMs were generated by kriging interpolation method and the Top to Raster, varying the spacing between the regular survey lines using horizontal scan lines to the regular survey lines. Through statistical analysis of the discrepancies between estimated by interpolating depths and depths observed in the scan lines of the bathymetric survey, the kriging showed better results for spacings of 40 and 80 meters. Considering the isobatimétricas between different DEMs created, it is observed that for larger spacings the interpolator to Top Raster presented smoother features when compared to the DEMs generated by kriging. / Com a evolução, nos últimos anos, dos métodos de levantamentos batimétricos utilizando sensores acústicos (ecobatímetros) e receptores de sinais transmitidos por satélites de navegação, torna-se possível descrever o relevo submerso com mesmo nível de detalhe com que se descreve o relevo da superfície terrestre. A representação gráfica do relevo submerso se dá a partir de Modelos Digitais de Elevação (MDEs) gerados por interpoladores que buscam, a partir das medidas realizadas, predizer a profundidade em locais não amostrados. Das informações geométricas extraídas de levantamentos batimétricos, o volume de água ou lama líquida presente, por exemplo em um reservatório, é a mais relevante. Este trabalho busca avaliar produtos gerados pelo levantamento batimétrico monofeixe, assim como os métodos de interpolação krigagem e Topo to Raster. As áreas de estudo foram uma caixa de decantação de estação de tratamento de água e um lago da represa de furnas, onde foram realizados levantamentos topográficos, com estação total e levantamentos batimétricos, com ecobatímetro monofeixe que opera nas frequências 33 kHz e 210 kHz. Na caixa de decantação, primeiramente foi realizado levantamento batimétrico (Lbat 1). Em seguida, esvaziou-se e limpou-se a caixa e, antes de enchê-la novamente, foi realizado um levantamento topográfico, (Ltop), com estação total. Logo após o enchimento, com água e sem lama decantada, foi realizado outro levantamento batimétrico (Lbat 2). Para o levantamento no lago da represa de furnas, realizou-se levantamento batimétrico automatizado, ou seja, empregando a tecnologia GNSS para o posicionamento. Primeiramente, com os dados do levantamento topográfico, se avaliou os métodos de interpolação krigagem e Topo to Raster na geração do MDE da caixa de decantação. A conclusão foi que o interpolador Topo to Raster condicionado apresentou notáveis deformações nas bordas e no centro da área de estudo, devendo ser descartado. A próxima etapa do trabalho foi avaliar a acurácia dos MDEs gerados aplicando krigagem nos dados do levantamento batimétrico monofeixe, Lbat 2, utilizando as frequências de 33 kHz e 210 kHz. De posse dos MDEs foram calculadas as discrepâncias entre informações extraídas deles e os pontos do levantamento topográfico. Os resultados apresentaram uma acurácia em torno de 5 cm, em profundidades médias de 3,21 m, e que, como os levantamentos foram realizados após a limpeza da caixa, com água limpa, não se verificou diferença significativa na acurácia dos MDEs gerados com as profundidades levantadas com as frequências 33 kHz e 210 kHz. Em seguida foram gerados os MDEs pela krigagem para o primeiro levantamento batimétrico, Lbat 1, quando ainda existiam resíduos sólidos resultantes do processo de decantação. Os volumes foram calculados e comparados a fim de avaliar a frequência de 33 kHz do ecobatímetro para determinar o volume de lama na caixa. Após analisar os resultados verificou-se que usando somente o primeiro levantamento batimétrico, com as frequências 33 kHz e 210 kHz, não se detectou 186 m3 de lama, num volume total de 799 m3 de água e lama, e que, com a água limpa, o volume determinado pela batimetria é acurado, apresentando discrepância de 0,63% para a frequência de 210 khz e 0,12% para a frequência de 33 khz. Para o levantamento do lago de furnas foram gerados MDEs pelo método de krigagem e pelo Topo to Raster, variando o espaçamento entre as linhas regulares de sondagem, utilizando linhas de verificação transversais às linhas regulares de sondagem. Através da análise estatística das discrepâncias entre as profundidades estimadas pelos interpoladores e as profundidades observadas nas linhas de verificação do levantamento batimétrico, a krigagem apresentou melhores resultados para espaçamentos de 20 a 80 metros. A diferença entre os volumes determinados para os espaçamentos de 20 a 40 metros foi menor que 2%,. Considerando as isobatimétricas entre os diversos MDEs criados, observa-se que para espaçamentos maiores o interpolador Topo to Raster apresentou feições mais suavizadas quando comparado com os MDEs gerados pela krigagem.

Le système « plante-ravageur-ennemi naturel » fournit un modèle de base idéal pour comprendre comment les communautés d'arthropodes sont structurées et comment les interactions (directes et indirectes) entre les différents acteurs contribuent à façonner la structure des communautés. Dans les agroécosystèmes, les forces "top-down" correspondent aux effets de contrôle que les organismes arthropodes des niveaux trophiques supérieurs (par exemple, les prédateurs) ont sur les espèces des niveaux inférieurs (par exemple, leurs proies). Les communautés d'arthropodes peuvent également être influencées par des forces "bottom-up" induites par des variations dans les régimes de fertilisation ou d'irrigation ou par des variations de certains traits des plantes (résistance aux herbivores ou adaptations aux stress environnementaux). De plus, les forces "bottom-up" peuvent affecter l'impact "top-down" des ennemis naturels sur les herbivores soit directement (par exemple, les effets sur prédateur omnivore) ou médiées par les insectes herbivores intermédiaires. Dans ce contexte, les objectifs de cette thèse ont été de comprendre comment les variations de l'apport des ressources dans les agroecoécosytsèmes (disponibilité en azote et en eau) peuvent influencer les interactions entre les plantes, les herbivores et les ennemis naturels. Cette question a été étudiée aussi bien à l'échelle individuelle (traits d'histoire de vie des insectes) que populationnelle (dynamique des populations). Les études ont été réalisées sur deux agroécosystèmes basés sur les cultures de la tomate et du coton. / The “Plant-herbivorous insect-natural enemy” system provides an ideal basic model to understand how the plant-inhabiting arthropod communities are structured and how various mechanisms (i.e. direct and indirect interactions) contribute to shape the community structure. In agro-ecosystems, top-down forces encompass the controlling effects that arthropod organisms of the higher trophic level (e.g., predators) have on species at the next lower level (e.g., prey). Arthropod communities may also be influenced by bottom-up forces induced by environmental variations (e.g. fertilization or irrigation regimes) or plant traits (plant insect-resistance or plant-adaptive traits). Furthermore, bottom-up forces may affect top-down forces on herbivores either directly (e.g., effects on omnivorous predator) or mediated by the intermediate herbivorous insects. In this context, the aims of the PhD study were to disentangle how variations in resource inputs (i.e. nitrogen and water availability) affect interactions among plant, herbivores and their natural enemies at both the individual (life-history traits) and population (population dynamic) levels. The studies were carried out on two agrosystems based on tomato and cotton. On tomato, the system 'Solanum lycopersicum L - leafminer Tuta absoluta - omnivorous predator Macrolphis pygmaeus' was used under laboratory and greenhouse conditions in France. We found strong evidence of bottom-up effects of nitrogen and/or water inputs on the herbivore and the omnivorous predator. Feeding ecology of the predator was also strongly influenced by water availability.

In a world that only spins faster and where information is available in abundance, the need to multi task has grown bigger than ever before. The need to eat or work from the sofa is growing, while the trends say that the coffee table should be low. This conflict of interest forces people to make a choice, following the trends or being able to easily multi task from the sofa. Or do they have to? The thesis work described in this report may provide a solution to the problem. The work consists of 10 credits and is carried out by two students as a final stage of the bachelor’s degree in Industrial Design Engineering at Luleå University of Technology. The work is carried out in collaboration with the furniture manufacturer Tenzo AB. Tenzo is a, privately owned, Swedish furniture manufacturer with a business idea aimed at trendy furniture in the international market, according to Tenzo (2018), 95% is exported to Europe and major retailers in France, Germany and Switzerland. The goal has been to develop a conceptual lift top coffee table. With a user-centered design process, the user was involved continuously throughout the work, during a workshop and in interviews with the goal of exploring the question ”What is important in a coffee table?”, in evaluative interviews and in Virtual Reality (VR) to test the concepts and ideas. The final concept embraces a more classical table shape than the lift top tables available on the market today, but is also developed with future trends in mind. The trends identified are colors with more hue than the bright pastels we see today, rounder and softer shapes than the boxynes observed among today’s lift top coffee tables, and that the light wood is replaced by darker woods. The color options presented give the table both the ability to melt into an environment or stick out and demand presence in the room.

Problematisering: Företag står inför utmaningar som handlar om att inkludera hållbarhetsbegreppets tre dimensioner: det ekonomiska, sociala och miljömässiga ansvaret. Påtryckningar ökar från samhällets olika intressenter, som sätter press på att företag och företagsledare agerar ansvarsfullt. Hållbarhet är idag en aktuell och relevant fråga som företag, styrelser och ledare på något sätt får ta i beaktning på grund av dessa påtryckningar från samhället. Relationen mellan ledarskap och hållbarhet är, enligt oss, en samhällsaktuell fråga för företag. Det finns idag omfattande forskning kring ledarskap och en hel del forskning om hållbarhet. Forskningen däremellan är däremot relativt outforskad. Det behövs därför en förståelse för hur denna relation ser ut. Syfte: Syftet med denna studie är att bidra till förståelse av hur relationen mellan ledarskap och hållbarhet ser ut i ett svenskt företag, samt identifiera de aspekter i ledarskapet som kan vara av betydelse för hållbarhet. Metod: För att besvara syftet är denna studie uppbyggd av en pilotstudie och en enfallsstudie av kvalitativ karaktär, där vi har genomfört semistrukturerade intervjuer med fem ledare i ledningsgruppen på Transdev Sverige AB. Studien har en induktiv ansats. Slutsats: Resultatet från denna studie har visat att relationen mellan ledarskap och hållbarhet ser olika ut. Ledningsgruppens kontext och ledarnas ansvarsområden har varit avgörande i beskrivningen av hur relationen ser ut. Kontexten och ansvarsområdena har dessutom varit avgörande för var i hållbarhetsbegreppet ledarna lägger sin tyngdpunkt. Relationen beskrivs vidare utifrån tre identifierade “relationsbyggare”: mål, moral och kunskap. Dessa tre är aspekter som vi anser vara av betydelse för hur relationen ser ut i denna studies specifika kontext. / Background: Due to increasing expectations and demands from different stakeholders, companies are being called upon to take actions to integrate the three dimensions of sustainability; economic, social and environmental. Corporate sustainability is therefore an inevitable topic of discussion among business organisations and top executives. Separately, there is extensive research on the two topics leadership and sustainability. However, the amount of research of the intersection of these two research fields is scarce and fairly unexplored, which makes this an interesting field of study. As a result of the actuality evolving around leadership and sustainability for corporations and the above stated lack of research, there is a need of a deeper understanding of the relationship between leadership and sustainability. Aim: The aim of this study is to understand the relationship between leadership and sustainability, as well as identifying aspects in the leadership that could be of importance regarding sustainability leadership. Methodology: This is a qualitative case study using a hermeneutics perspective of interpretation. The empirical data consist of a pilot study and five semi-structured interviews with top executives at Transdev Sverige AB. The study revolves around the empirical data and is therefore to be considered to have an inductive approach. Conclusion: The findings of the study has shown that the relationship between leadership and sustainability differ. The context of the top management team and the responsibility of the leaders have been vital in the explanation of their relationship. The context and the area of responsibility have additionally been vital in order to identify where in the sustainability spectrum the leader position himself. The relationship is further explained by three identified “relationship builders”; goal, morale and knowledge. We consider that these three aspects are of relevance to understand the relationship between leadership and sustainability within the specific context of this study.

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.