Variações temporais na tensão de cisalhamento do vento, na Plataforma Continental Sudeste do Brasil (PCSE), perturbam o equilíbrio geostrófico gerando movimentos com frequências próximas à inercial local. Estas perturbações se propagam horizontalmente e verticalmente, interagindo com o fluxo médio e alterando as características hidrográficas e hidrodinâmicas. Foram analisados dados observacionais de corrente, registrados por correntógrafos fundeados às isóbatas de 50 m e 100 m, ao largo de Arraial do Cabo (RJ) e Ubatuba (SP), de vento registrados por bóias meteorológicas e de salinidade e temperatura perfilados em função da profundidade em estações hidrográficas, obtidos no âmbito do Projeto DEPROAS (Dinâmica do Ecossistema de Plataforma da Região Oeste do Atlântico Sul), entre 2001 e 2002. Os resultados das análises indicaram que a média de duração dos eventos de oscilações inerciais é 7,5 dias com desvio padrão de 3,8 dias, sendo 6,8 o número médio de oscilações em cada evento (desvio padrão de 3,3 oscilações). O período inercial efetivo médio foi calculado em 26,5 h com deslocamento médio da frequência inercial em 12,2%, devido ao desvio Doppler causado pelas interações com a vorticidade relativa do fluxo básico. As correntes inerciais horizontais, filtradas a partir das séries correntográficas, apresentaram valores entre 3 e 10 cm/s. Foi observada propagação vertical das oscilações inerciais e calculado o valor da velocidade de grupo vertical em -2,59 .10-2 cm.s-1. A partir desse resultado, foi obtido o valor de 28,3 m de profundidade para o valor máximo de velocidade vertical das partículas de água na onda interna inercial forçada pela oscilação das isotermas, em acordo com resultados observados de máxima corrente inercial logo abaixo da camada de mistura. O valor calculado para a amplitude da oscilação vertical das isotermas foi 17,2 m, próximo aos 19 m registrado com os resultados observacionais em períodos de mudança do campo de ventos. O modelo numérico hidrodinâmico ROMS (Regional Ocean Modelling System) comprovou resultados observacionais em relação à capacidade de mudanças na tensão de cisalhamento do vento, em períodos menores que o inercial local, gerarem oscilações inerciais. Os resultados numéricos com o ROMS permitiram analisar a interação das oscilações inerciais com o fluxo médio em diferentes regiões da PCSE, através de diferentes condições de estratificação da coluna de água e, a partir da trajetória de pseudoderivadores, estimar os raios das trajetórias com ordem 10 km. / Temporal variations in the wind stress, on the South Brazil Bight, disturb the geostrophic equilibrium and generate motion with near inertial frequencies. The disturbances propagate horizontally and vertically, interacting with the basic motions and altering the hydrodynamics and hydrographic characteristics. Observational data of currents, collected by currentmeters deployed in the 50 m and 100 m isobaths, offshore Arraial do Cabo (RJ) and Ubatuba (SP), of winds collected in meteorological buoys and of salinity and temperature vertically profiled in hydrographic stations, during the project DEPROAS (Dinâmica do Ecossistema de Plataforma da Região Oeste do Atlântico Sul), in the years of 2001 and 2002, have been analyzed. Results showed that the mean duration of the inertial oscillations events is 7.5 days, with standard deviation of 3.8 days, being 6.8 the mean number of oscillations in each event (standard deviation of 3.3 oscillations). The calculated mean effective inertial period is 26.5 h, with a mean difference of the local inertial frequency of 12.2% due to the Doppler shift caused by interactions with the relative vorticity of the basic flow. The horizontal inertial currents, filtered from the current time series, presented values between 3 and 10 cm/s. Vertical propagation of the inertial oscillations were observed and the calculated value for the vertical group velocity was -2.59 . 10-2 cm/s. From these results, the calculated value for the depth of maximum water vertical velocity was 28.3 m for the internal inertial wave forced by the isotherms oscillations, in accordance with results observed of maximum vertical velocities occurring below the mixing layer. The calculated value for the amplitude of vertical oscillations of isotherms was 17.2 m, approximately equal to the 19 m observed in the data set during periods of wind shift. The numerical hydrodynamical model ROMS (Regional Ocean Modeling System) confirmed the observational results that changes in the wind field with periods smaller than the local inertial period generate inertial oscillations. The numerical results with ROMS allowed to analyze the interaction between the inertial oscillations and the basic flow in different regions of the South Brazil Bight, due to vertical different stratification characteristics of the sea water, and from the trajectories of pseudo-drifters it was possible to estimate the radius of the trajectories as having order of magnitude of 10 km.

Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2018-05-24T17:46:38Z No. of bitstreams: 2 Isabel Cristina Moresco.pdf: 778049 bytes, checksum: 0c5c3dc6a4ac6f42d2f9a40313cd38c6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-05-24T17:46:39Z (GMT). No. of bitstreams: 2 Isabel Cristina Moresco.pdf: 778049 bytes, checksum: 0c5c3dc6a4ac6f42d2f9a40313cd38c6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-08 / In the last 20 years, with the emergence of multiresistant gram-negative bacteria, polymyxins, which had fallen into disuse due to their high toxicity, were once again used as an alternative for the treatment of these infections. This antibiotic group is active against most enterobacteria and non-fermenting gram-negative bacteria, ocular, urinary tract, meninges, and bloodstream infections. The recommended dose of polymyxin B (PMB) in patients with normal renal function is 1.5 to 2.5 mg.kg-1.day-1 and the dose can be divided twice. For patients with impaired renal function, it is recommended to adjust the dose according to creatinine clearance. Because nephrotoxicity is the major limiting factor in the use of this class of antibiotics, a retrospective observational study was conducted to identify possible risk factors for the development of acute renal injury (ARF) in patients using the antibiotic PMB. The necessary information was collected to perform the study in medical records, medical prescriptions and results of laboratory tests from the patients who used PMB in a period of 5 years in a Brazilian hospital. Inclusion criteria for the study were: patients over 18 years of age who used intravenous PMB for more than 72 hours. To classify ARI levels, baseline creatinine was calculated by the average of the last five serum creatinine tests before the first dose of the antibiotic. This calculated value and the highest level of serum creatinine during treatment were used to identify and classify renal damage according to the criteria of the RIFLE (Risk, Injury and Failure and Loss and End-stage renal disease) filtration rate. The study included 120 patients, most of them male (89; 74.2%) with an average age of 50 years. The most frequent pre-existing comorbidities were systemic hypertension (50; 41.7%), diabetes mellitus (21; 17.5%), nephropathies (14; 11.7%) and obesity (13; 10.8%). The main infection was pneumonia (35.8%) and the most frequently identified infectious agent was Acinetobacter baumannii (67.9%). PMB treatments were performed for 13 days and the average daily dose was 191.5 mg. The high incidence of mortality in the studied population (46.7%) may be related to the critical clinical status of the patients, because at some point of hospitalization, 111 patients (92.5%) needed intensive care. In the population studied to evaluate risk factors, 12 patients (13.5%) presented risk, 22 (25.0%) injury, 30 (34.1%) renal failure, according to RIFLE criteria. In addition, in the group that patients developed ARF, 51.9% died, whereas in the group that did not present, only 12.5% died. There was a statistically significant difference between the groups that developed or not ARF, for the following variables: treatment time greater than 10 days, accumulated PMB dose, hypoalbuminemia and concomitant use of furosemide. However, the variables that remained in the final multivariate logistic regression model were treatment time greater than 10 days and hypoalbuminemia. Several factors inherent to the patient and the drug are related to ARF and strategies should be created in order to minimize these effects. The monitoring of renal function in all patients, especially those at risk, and the follow-up of the infection to reduce the time of treatment are highlighted. / Nos últimos 20 anos, com o surgimento de bactérias gram-negativas multirresistentes, as polimixinas, que tinham caído em desuso pela elevada toxicidade, voltaram a ser utilizadas como uma alternativa para tratamento dessas infecções. Esse grupo de antibiótico é ativo contra a maioria das enterobactérias e das bactérias gram-negativas não fermentadoras, em infecções oculares, do trato urinário, das meninges e da corrente sanguínea. A dose recomendada de polimixina B (PMB), em pacientes com função renal normal, é de 1,5 a 2,5 mg Kg-1 dia-1 e a dose pode ser dividida em duas vezes. Para os pacientes com alteração da função renal, recomenda-se ajustar a dose de acordo com a depuração de creatinina. Como a nefrotoxicidade é o maior limitante do uso dessa classe de antibióticos, um estudo observacional retrospectivo foi realizado com o objetivo de identificar os possíveis fatores de risco para o desenvolvimento de injúria renal aguda (IRA) em pacientes que utilizaram o antibiótico PMB. Foram coletadas as informações necessárias para realizar o estudo em prontuários, prescrições médicas e resultados de exames laboratoriais dos pacientes que utilizaram PMB em um período de 5 anos em um hospital brasileiro. Os critérios de inclusão para o estudo foram: pacientes maiores de 18 anos que utilizaram PMB por via endovenosa por mais de 72 horas. Para classificar os níveis de IRA, a creatinina basal foi calculada pela média entre os cinco últimos exames de creatinina sérica antes da primeira dose do antibiótico. Esse valor calculado e o maior nível de creatinina sérica durante o tratamento foram usados para identificar e classificar o dano renal segundo os critérios da taxa de filtração glomerular de RIFLE (Risk, Injury and Failure and Loss, and End-stage renal disease). Foram inclusos no estudo 120 pacientes, a maioria do sexo masculino (89; 74,2%) com média de idade de 50 anos. As comorbidades pré-existentes presentes com maior frequência foram hipertensão arterial sistêmica (50; 41,7%), diabetes mellitus (21; 17,5%) nefropatias (14; 11,7%) e obesidade (13; 10,8%). A principal infecção tratada foi pneumonia (35,8%) e o agente infeccioso mais identificado foi o Acinetobacter baumannii (67,9%). Os tratamentos com a PMB foram realizados durante 13 dias e a dose média diária de 191,5 mg. A alta incidência de mortalidade da população estudada (46,7%) pode estar relacionada ao estado clínico crítico dos pacientes, pois, em algum momento do internamento, 111 pacientes (92,5%) precisaram de cuidados intensivos. Na população estudada para avaliar os fatores de risco, 12 pacientes (13,5%) apresentam risco, 22 (25,0%) injúria, 30 (34,1%) falência renal, segundo os critérios de RIFLE. Além disso, no grupo que os pacientes desenvolveram IRA, 51,9% foram a óbito, enquanto que no grupo que não apresentou foram apenas 12,5%. Houve diferença estatisticamente significativa entre os grupos que desenvolveram, ou não, IRA, para as seguintes variáveis: tempo de tratamento superior a 10 dias, dose acumulada de PMB, hipoalbuminemia e uso concomitante de furosemida. Porém, as variáveis que permaneceram no modelo final de regressão logística multivariável foram o tempo de tratamento superior a 10 dias e a hipoalbuminemia. Vários fatores inerentes ao paciente e à droga estão relacionados à IRA e estratégias devem ser criadas com o intuito de minimizar esses efeitos. Destacam-se a monitorização da função renal em todos os pacientes, principalmente os de risco, e o acompanhamento da infecção para diminuir o tempo de tratamento.

Introdução: A obesidade é uma doença crônica de incidência global e crescente que se tornou nas últimas décadas um dos maiores problemas de saúde pública nas sociedades urbanas. A intervenção cirúrgica, ou cirurgia bariátrica, tem sido apontada como eficaz no tratamento das formas graves de obesidade e a derivação gástrica em Y de Roux (DGYR) é o tipo mais realizado no mundo e no Brasil. O acompanhamento contínuo de todos os indivíduos submetidos à DGYR por equipe multidisciplinar é recomendado por se tratar de uma cirurgia de grande porte com riscos de complicações em longo prazo, entre elas as deficiências nutricionais. Por isso, as consultas nutricionais pós-operatórias são um componente importante desse seguimento. Objetivos: Estimar a prevalência de adesão ao seguimento nutricional ambulatorial pós-cirurgia bariátrica e avaliar a associação dessa adesão com fatores selecionados em um grupo de obesos moderados com comorbidades e obesos mórbidos submetidos à DGYR. Métodos: Estudo de coorte retrospectiva utilizando-se dados de prontuários hospitalares de 241 adultos de ambos os sexos submetidos à derivação gástrica pelo Sistema Único de Saúde entre 2006 e 2008 no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Considerou-se aderente o indivíduo que compareceu a quatro ou mais consultas nutricionais nos 12 primeiros meses após a cirurgia. Para estimar a associação da adesão ao seguimento nutricional pós-cirúrgico com os fatores idade, sexo, estado conjugal, escolaridade, situação empregatícia, distância entre a residência e o hospital, estratégias para perda de peso no período pré-operatório, índice de massa corpórea (IMC) no précirúrgico imediato, presença de comorbidades e duração da internação após a cirurgia, foram calculadas as Razões de Prevalência (RP) e os intervalos de 95% de confiança (IC 95%); para a análise ajustada utilizou-se regressão múltipla de Poisson. Resultados: A população de estudo foi caracterizada pelo predomínio de mulheres (80,9%), pela média de idade de 44,4 anos (±11,6), pela média de IMC pré-operatório de 47,2kg/m2 (±6,16) e 78,4% dos participantes apresentaram uma ou mais comorbidades. Convivência com companheiro foi relatada por 51,5% da população, 41,9% referiram ter ensino fundamental incompleto como nível de escolaridade, 50,9% não possuíam atividade remunerada, 44,7% residiam à distância de até 16 km do hospital e 11,6% ficaram internados por seis ou mais dias após a cirurgia. A prevalência de adesão nessa população foi de 56,0% (IC 95% 49,7-62,3). A análise multivariada revelou que somente duração da internação maior ou igual a seis dias foi associada à adesão ao seguimento nutricional pós-cirúrgico (RP=1,46 IC 95% 1,15-1,86). Conclusões: A prevalência de adesão encontrada nesta população foi semelhante às dos estudos internacionais, mas menor do que a prevalência mínima de 75% recomendada para que o centro seja reconhecido como de excelência em cirurgia bariátrica. Os indivíduos que ficaram internados por mais tempo no pós-cirúrgico mostraram-se significantemente mais aderentes ao seguimento nutricional, podendo sugerir que o maior contato desses com a equipe multiprofissional pode ter contribuído para aumentar a percepção da gravidade da doença e da necessidade de cuidados contínuos com a saúde, e consequentemente ter levado à maior assiduidade às consultas ambulatoriais / Introduction: Obesity is a global chronic disease with increasing incidence during the past decades and has become one of the major public health problems in the urban societies. The surgical intervention, or bariatric surgery, has been considered as an effective treatment of the severe forms of obesity and the Roux-en-Y gastric bypass (RYGB) has been the commonest surgical procedure worldwide, including in Brazil. The long term outpatient postoperative follow up after bariatric surgery by a multidisciplinary team has been recommended to all individuals submitted to RYGB because it is a major surgery which can cause complications such as nutritional deficiencies. Therefore, nutritional assessment in the postoperative period is an important component of the follow up. Objectives: To estimate the prevalence of adherence to outpatient postoperative nutritional follow up after bariatric surgery and to analyze the association between adherence and selected factors in a group of moderately obese with comorbidities and morbidly obese adults who underwent RYGB. Methods: Retrospective cohort study using data from hospital records of 241 adults of both sexes who were submitted to RYGB by the Unified Health System between 2006 and 2008 at the Hospital das Clínicas - Medical School, University of São Paulo. It was considered adherent the individuals who attended four or more nutritional appointments in the first 12 months after surgery. To estimate the association between adherence to postoperative nutritional follow up and factors such us age, sex, marital status, education, employment status, distance between home and hospital, strategies for weight loss in the preoperative period, body mass index (BMI) in the immediate pre-surgical, presence of comorbidities and duration of hospitalization after surgery, were calculated the Prevalence Ratios (PR) and the 95% confidence intervals (95% CI); for the adjusted analysis, Poisson multiple regression was used. Results: The study population was characterized by the predominance of women (80.9%), the mean age of 44.4 years (±11.6), the mean of preoperative BMI of 47.2kg/m2 (±6.16) and 78.4% of participants presented one or more comorbidities. Living with partner was reported by 51.5% of the population, 41.9% had incomplete primary education level, 50.9% had no paid work, 44.7% lived at a distance of up to 16km to the hospital and 11.6% were hospitalized for six or more days after surgery. The prevalence ratio of adherence in this population was 56.0% (95% CI 49.7- 62.3). Multivariate analysis revealed that only length of hospital stay greater than or equal to six days was associated with adherence to nutritional follow up in the postoperative period (PR=1.46 95% CI 1.15-1.86). Conclusions: The prevalence of adherence found in this population was similar to those of international studies, but less than the minimum prevalence of 75% recommended for services to be recognized as a bariatric surgery center of excellence. Individuals who were hospitalized for longer than six days after surgery were significantly more adherent to the nutritional follow-up. This may have happened because they had longer contact with the multidisciplinary team which may have contributed to increase their perception of disease severity and the need for long term health care, and consequently, it may have led to higher assiduity to the nutritional appointments

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-08-04T13:20:22Z No. of bitstreams: 1 nataliamariadasilvafernandessuassuna.pdf: 21230396 bytes, checksum: 11fc04717340958f54acd5fd7282c5b8 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-08T18:07:29Z (GMT) No. of bitstreams: 1 nataliamariadasilvafernandessuassuna.pdf: 21230396 bytes, checksum: 11fc04717340958f54acd5fd7282c5b8 (MD5) / Made available in DSpace on 2017-08-08T18:07:29Z (GMT). No. of bitstreams: 1 nataliamariadasilvafernandessuassuna.pdf: 21230396 bytes, checksum: 11fc04717340958f54acd5fd7282c5b8 (MD5) Previous issue date: 2009-03-20 / O presente estudo utilizou registros sistematizados de dados nacionais e locais sobre pacientes em terapia renal substitutiva (TRS) fundamentais para o conhecimento epidemiológico da realidade do tratamento dialítico. Estes dados podem permitir uso mais racional dos recursos econômicos, identificação das intervenções, visando à melhoria da terapêutica, diminuição da morbimortalidade desses pacientes. No Brasil, a Sociedade Brasileira de Nefrologia, mantém, desde 1999, registros parciais sobre pacientes em TRS. Os objetivos do estudo foram coletar dados demográficos, clínicos, laboratoriais e desfechos (óbito, recuperação da função renal, transferência para hemodiálise, falência da técnica, transplante renal, tranferência para outro centro ou perda de seguimento) de pacientes em diálise peritoneal (DP) tratados em centros de todas as regiões do Brasil para descrição das características epidemiológicas desta população e avaliação dos fatores relacionados à falência da técnica e mortalidade. Para tal foi desenhado um estudo multicêntrico, envolvendo centros de todas as regiões do país, iniciado em dezembro de 2004 e com seguimento até outubro de 2007. Foi desenhado um software com os dados preenchidos off fine e enviados on fine a um servidor. Neste ponto, os dados foram extrídos em MySQL, sendo montada uma base de dados, posteriormente, transportada para o software estatístico SPSS 13.0 e SAS. Ao final, foram analisados 6.198 pacientes de 102 centros. Os resultados mostram que o Brasil apresenta um baixo número de pacientes em diálise peritoneal, com um viés de seleção para esta modalidade, onde a maioria dos pacientes apresenta inúmeras comorbidades tendo como indicação clínica "única possibilidade terapêutica ou indicação médica". Apesar disto, há um baixo índice de complicações infecciosas (1 episódio de peritonite/30 meses) e a taxa de saída no período inicial de 34 meses foi de 37,7%, com um média anual de 13,3%. A meta mais difícil de ser alcançada é a hemoglobina, notadamente em diabéticos e pacientes egressos de outras TRSs. A principal causa de saída foi óbito (21%), sendo as causas cardiovasculares as mais prevalentes (40%). Entre os principais fatores relacionados à mortalidade e falência da técnica foram encontrados a idade, diabetes mellitus, doença cardiovascular. Houve relação direta da mortalidade da população geral com a mortalidade da população em diálise peritoneal. Foram observadas diferenças regionais importantes quanto às taxas e motivos de saídas nas diversas regiões do país, bem como, a ocorrência da "epidemiologia reversa" da obesidade nesses pacientes. O estudo permitiu traçar o perfil epidemiológico dos pacientes em diálise peritoneal no Brasil e concluir que, a despeito do importante viés de seleção, nosso país apresenta uma diálise peritoneal adequada, comparada a países desenvolvidos europeus. / Systematic registers of local and national data on patients in renal replacement therapy (TRS) are critical to the epidemiological knowledge of the reality of the dialysis treatment. These data may allow more rational use of economic resources, identify interventions to improve the treatment, and to decrease morbidity and mortality of these patients. In Brazil, the most recent dialysis register made available by the Brazilian Society of Nephrology is based on data obtained from 1999 patients on renal replacement therapy. This study aimed to collect demographic, clinical, laboratory and outcomes (death, recovery of renal function, transfer to hemodialysis, the technical failure, kidney transplantation, transfer to another center or loss of follow-up) of patients on peritoneal dialysis (PD) treated in dialysis clinics located in all regions of Brazil to describe the epidemiological characteristics of this population and assess the factors related to the risk of the technique failure and mortality of patients. A multicenter study was designed involving patients of 102 centers in all the regions of the Brazil, initiated in December of 2004, with the last set of date obtained in October 2007. A software was designed with the data registered offline and sent online to a central server. The data were extracted in MySQL and originating a database that was initially validated and then transfered to the statistical software SPSS 13.0 and SAS. This extraction was performed in two stages. At the end of the study, 6198 patients were analyzed. Brazil has a low number of patients on peritoneal dialysis, with a selection bias for this treatment modality, where the majority of patients presents numerous co-morbidities and and has peritoneal dialysis as the only therapeutic option. There is a low rate of infectious complications (1 episode of peritonite/30 months) and the rate of drop-out during the study was 37.7%, with an annual average of 13.3%. The more difficult goal to be achieved is the hemoglobin, especially in diabetic patients and arising from hemodialysis. The main cause of drop-out was death (21%), being the cardiovascular diseases the most prevalent (40%). Age, diabetes mellitus, cardiovascular disease were among the main factors related to mortality and failure of the technique. It was seen a positive direct relationship of mortality when the general population was compared with patients on peritoneal dialysis. Furthermore, we observed marked regional differences in the rates and reasons for dropouts of patients in the different regions of the country. It was also seen the existence of the "reverse epidemiology" of obesity in these patients. In conclusion, our study allowed us to outline an epidemiological profile of peritoneal dialysis in Brazil and confirm the good quality of PD that is offered to our patients when compared to developed European countries, despite of the selection bias at the choice of TRS.

Le milieu circum-galactique (CGM pour "Circum-Galactic Medium" en anglais) constitue l'interface entre les galaxies et les grandes structures au sein desquelles elles évoluent. Le milieu inter-galactique est principalement composé de gaz d'hydrogène froid, dit primordial, qui en s'accretant sur les galaxies constitue le carburant de la formation stellaire. La formation stellaire apparait alors régulée par les échanges de matière entre la galaxie et l'extérieur. En ce sens, l'étude de l'environnement des galaxies se révèle cruciale pour comprendre les mécanismes qui régissent leur formation et leur évolution. L'observation directe du CGM est toutefois assez délicate en raison de la chute de brillance des galaxies dans leurs régions externes. Sa détection est d'autant plus difficile pour les galaxies de l'Univers lointain. Quelques techniques existent pour contrecarrer cette difficulté : l'observation du CGM en absorption dans le spectre d'un quasar brillant situe sur la ligne de visée de la galaxie, ou sa détection statistique en combinant de nombreuses images de galaxies. Ces techniques ont toutefois de sévères limitations car elles ne donnent que des informations parcellaires sur le CGM. Je rapporte dans cette thèse la détection de gaz d'hydrogène froid autour de 145 galaxies (soit 80% des galaxies testees) peu massives, peu lumineuses et très distantes, émettant de l'émission Lyα. Longtemps utilisée pour son pouvoir de détection des galaxies lointaines, l'émission Lyα est maintenant utilisée comme un traceur du gaz froid du CGM, alors observable sous forme de "halos" Lyα. Notre échantillon constitue le plus grand échantillon de halos Lyα détectés individuellement autour de galaxies de faible masse et ce, à une époque pendant laquelle l'Univers est en pleine construction. Ces avancées ont été rendues possible grâce à l'incomparable sensibilité de l'instrument MUSE installé sur le "Very Large Telescope" au Chili il y a bientôt 4 ans. Seule une centaine d'heures de télescope dans la région du champ ultra profond de Hubble ont été nécessaires pour permettre la détection de halos Lyα. Nos résultats confirment la présence de grande quantité de gaz froid dans l'environnement immédiat des galaxies distantes. Ces observations étaient en effet prédites par les modèles théoriques et les simulations numériques. En plus d'être quasi-omniprésents autour des galaxies, les halos Lyα observés montrent une diversité (taille, flux, forme, profil de la raie d'émission, etc) particulièrement remarquable dans une région du ciel si restreinte (9_×9_). De plus, la possibilité d'analyser le CGM galaxie par galaxie et en trois dimensions permet maintenant d'étudier de manière directe l'impact de l'environnement sur la galaxie mais aussi l'évolution des propriétés du CGM avec les époques cosmiques. Notre grand échantillon de galaxies nous a permis de réaliser un traitement statistique robuste et de mettre en évidence que les propriétés stellaires des galaxies étudiées ne sont pas systématiquement liées à celles de l'émission Lyα. Enfin, d'après les modèles théoriques, nos observations (spectroscopiques) indiquent la présence de matière en expansion dans et/ou autour des galaxies. La présence d'accrétion de matière est, quant à elle, moins bien contrainte par nos données. Finalement, l'analyse décrite dans ce manuscrit rapporte des informations importantes et inédites sur les propriétés du CGM d'une population de galaxies relativement peu lumineuses et très abondantes dans l'Univers lointain / The circum-galactic medium (CGM) serves as the interface between galaxies and the larger structures within which they evolve. Composed primarily of cold hydrogen gas (also called primordial gas), the CGM is a major fuel source for star formation as material falls onto a galaxy from its surrounding halo. This suggests that star formation is in fact regulated by gas exchange between a galaxy and its vicinity. Thus, studying the surrounding environment of galaxies represents a crucial step in understanding the mechanisms governing their formation and evolution. Unfortunately, direct observation of the CGM is often quite difficult, since these regions are very faint. This task becomes even more challenging for galaxies in the distant Universe, though some techniques have been developed for this purpose. The CGM can be detected through absorption features in the spectrum of a more-distant quasar located along a galaxy’s line of sight or statistically, by stacking many images of galaxies together, in order to increase the overall S/N ratio of the sample. However, these methods are not ideal : both have severe limitations and only provide partial information about the CGM. In this thesis, I report the detection of cold hydrogen gas surrounding 145 low-mass, faint and very distant galaxies emitting Lyα photons (forming 80% of the total galaxy sample used in this work). While historically, Lyα emission was seen simply as a powerful tool for detecting distant galaxies, it is now possible to use it as a tracer of cold CGM gas in the form of Lyα halos. The sample presented here represents the largest collection ever compiled of individually-detected Lyα halos around normal star forming galaxies, observed in an epoch when the Universe was still forming. This achievement is possible thanks to the unrivaled sensitivity of the Multi-Unit Spectroscopic Explorer (MUSE), a next-generation instrument installed on the Very Large Telescope (VLT). In particular, we need only 100 hours of telescope time to detect the presence of Lyα halos, a significant improvement over previous efforts. My results confirm the presence of large amounts of cold gas in the immediate vicinity of distant galaxies. While such results have been predicted by theoretical models and numerical simulations, this work provides some of the first direct observational evidence of this fact. Besides being quasi-ubiquitous around galaxies, the observed Lyα halos show a large diversity in physical properties which is particularly remarkable for such a small region of the sky (9_×9_). Moreover, the 3D galaxy-by-galaxy nature of my analysis allows me to study the direct impact of environment on galaxies, as well as the evolution of the CGM with cosmic time. With such a large sample, I am also able to perform a robust statistical analysis, highlighting the fact that the stellar properties of galaxies are not systematically linked to the Lyα ones. Finally, based on theoretical models, my (spectroscopic) observations indicate the presence of expanding materials inside and/or around the galaxies. However, the presence of galactic inflows are less constrained by the data. Taken as a whole, the analysis described in this thesis represents important, new information about the CGM properties of the relatively faint galaxies which make up the bulk of the galaxy population in the distant Universe. Therefore, this work should serve as a useful reference point as research into the CGM continues to advance

Le lambda-calcul est un formalisation de la notion de calcul. Dans cette thèse nous nous intéresserons à certaines variantes non déterministes, et nous nous pencherons plus particulièrement sur le cas probabiliste.L'étude du lambda-calcul probabiliste n'est pas nouvelle, mais les travaux précédents considéraient le comportement probabiliste comme un effet de bord. Notre objectif est de présenter ce calcul d'une manière plus équationnelle, en intégrant le comportement probabiliste à la réduction.Tout d'abord nous définissons une sémantique opérationnelle déterministe et contextuelle pour le lambda-calcul probabiliste en appel par nom. Afin de traduire la signification de la somme nous définissons une équivalence syntaxique dans notre calcul, dont nous démontrons qu'il ne déforme pas la réduction: considérer une réduction modulo équivalence revient à considérer simplement le résultat du calcul modulo équivalence. Nous prouvons également un résultat de standardisation.Dans ce cadre nous définissons une notion de théorie équationnelle pour le lambda-calcul probabiliste. Nous étendons certaines notions usuelles, et en particulier celle de bon sens. Cette dernière se formalise facilement dans un cadre déterministe mais est bien plus complexe dans le cas probabiliste.Pour finir nous prouvons une correspondance entre l'équivalence observationnelle, l'égalité des arbres de Böhm et la théorie cohérente sensée maximale. Nous définissons une notion d'arbres de Böhm probabilistes dont nous prouvons qu'elle forme un modèle. Nous démontrons ensuite un résultat de séparabilité disant que deux termes avec des arbres de Böhm distincts ne sont pas observationnellement équivalents. / The lambda-calculus is a way to formalize the notion of computation. In this thesis we will be interested in some of these variants introducing non deterministim, and we will focus mostly on a probabilistic calculus.The probabilistic lambda-calculus has been studied for some time, but the probabilistic behaviour has always been treated as a side effect. Our purpose is to give a more equational representation of this calculus, by handling the probabilities inside the reduction rather than as a side effect.To begin with we give a deterministic and contextual operational semantics for the call-by-name probabilistic lambda-calculus. To express the probabilistic behaviour of the sum we introduce a syntactic equivalence in our calculus, and we show it has little consequence on the calculus: reducing modulo equivalence amount to reducing and then looking at the result modulo equivalence. We also prove a standardization theorem.Then using this operational semantics we define a notion of equational theories for the probabilistic lambda-calculus. We extend some usual notions to this setting, and in particular the sensibility of a theory. This notion is quite simple in a deterministic setting but becomes more complicated when we have a probabilistic computation.Finally we prove a generalization of the equality between the observational equivalence, the Böhm tree equality and the maximal coherent sensible lambda-theory. We give a notion of probabilistic Böhm trees, and prove that this forms a model of the probabilistic lambda-calculus. Then we prove a separability result stating that two terms with different Böhm trees are separable, i.e. are not observationally equivalent.

The world today faces many challenges in terms of sustainability and how the world will be able to continue to meet demands of future generations. Sustainability aspects are considered by customers and organizations to a greater extent today than ever before. Businesses need to find new ways forward to encourage sustainable consumption to be able to exist in the future. The increasing amount of food waste represents one of many sustainability challenges and is a stated problem in developed countries. In Sweden, the households stand for the biggest amount of food waste along the entire supply chain. Producing something that is later wasted is an inefficient use of resources. This study aims to identify barriers for consumers to act pro-environmentally when consuming products of low involvement and find ways for the industry to overcome them. The thesis is commissioned for a large bread company in Sweden, who is in the starting blocks of start selling frozen bread, something that is not done to a great extent today. Frozen bread is a more environmentally sustainable alternative than substitute products and it will serve as the low-involvement product in focus of this study. The theoretical framework is built on theories regarding consumer decision-making, consumer behavior, sustainability and sustainable consumption. Through in-store observations of customers accompanied by follow-up interviews, a solid amount of data was gathered which allowed the authors to address the gap between intentions and behavior. Semi-structured interviews with the manager of the grocery store and the commissioned company give insights to the industry perspective of sustainability and consumer behavior. The empirical findings are presented from each data collection instance and are later analyzed and discussed with regard to four sub-purposes and the theoretical framework. The results have shown that existing barriers relate to customers’ habits, inertia, attitudes and lack of knowledge. The industry has the opportunity to bring forward sustainable products without tradeoffs, to create a win-win situation. By appealing to the customers’ hedonic needs and informing them about environmental benefits it is possible to influence customer norms to achieve a pro-environmental behavioral change.

>Magister Scientiae - MSc / There have been a number of attempts to measure the expansion rate of the Universe using age-dating of Luminous Red Galaxies (LRGs).Assuming stars in LRGs form at the same time, age-dating of two populations of LRGs at different redshifts can provide an estimate of the time difference associated with the corresponding redshift interval (dt/dz). This gives a direct estimate of the Hubble parameter at the average redshift of the two populations. In this thesis, we explore the validity of the assumptions in this method using LRGs identified in the Millenium Simulation.We study the properties of LRGs simulated using two semi-analytical models for galaxy evolution and discuss LRG selection criteria. We use stellar population modelling and spectral synthesis to estimate the errors on ages that can be expected and discuss optimization of an age-dating experiment.We find that H(z) using simulated galaxies from MS can be recovered with high accuracy. Using Single Stellar Populations (SSPs) to age -date LRGs is not sufficient for this experiment but if the star formation histories of galaxies are used, accurate ages are obtainable. We discuss an observing program to carry out this experiment using SALT (Southern African Large Telescope).

Cette recherche s’intéresse aux mouvements de contestation à l’égard du système marchand et de ses dispositifs, ayant pour mobile les préoccupations sociales et environnementales. Ce travail vise à rendre compte de l’existence du phénomène de la résistance socialement responsable (RSR) à la consommation et de son intérêt, compte tenu de sa singularité et des enjeux managériaux qu’il implique. A travers une approche netnographique non participante mobilisant une méthode interprétativiste d’analyse des données, la recherche repose sur l’étude de trois communautés distinctes et représentatives du phénomène étudié, débouchant sur deux résultats majeurs. D’une part, la recherche aboutit à l’élaboration d’une conceptualisation compréhensive du phénomène, explicitant les facteurs déclencheurs, les caractéristiques, ainsi que le répertoire des manifestations de la RSR. D’une autre part, le travail de recherche met en exergue les perspectives d’évolution et de réforme des pratiques, méthodes et stratégies du marketing. / This research focuses on protest movements towards market system and its devices, having for main motive the social and environmental concerns. This work aims at underlining the existence of the socially responsible resistance (SRR) and therefore its interest, considering its uniqueness and the managerial challenges that it implies. Through an observational netnography approach using an interpretativist method for data analysis, the research is based on a study of three virtual different communities’representative of the investigated phenomenon and leads to two major results. On the first hand, the research end in an understanding conceptualization of the phenomenon, stressing its initiator factors, caracteristics, but also the SRR wide range of expression forms. On the other hand, this work emphasizes evolution and reform perspectives of marketing practices, methods and strategies.

The long-term global mean temperature depends on the total amount of anthropogenic CO2 emitted. This direct link between temperature and cumulative CO2 emissions has implications for policymakers, as the cumulative emissions framework identifies the total amount of carbon that can be emitted, referred to as a cumulative carbon budget, that is consistent with reaching stabilization of the global mean temperature at desired levels, such as 1.5 °C or 2.0 °C warming above the pre-industrial level. This dissertation is a compilation of three studies that explore the relationship between warming and cumulative carbon emissions at high amounts of total carbon emitted (Project I; Chapter 2), its sensitivity to non-CO2 forcing (Project II; Chapter 3), and constraining the climate model responses with observations, in order to provide more accurate estimates of the carbon budget consistent with 1.5 °C warming above the pre-industrial level (Project III; Chapter 4). A joint summary of the key findings from each project, and their significance, is presented in Chapter 5. / Graduate / 2018-05-29