<p>The problem is two fold: how does natural selection operate on systems of interacting genes and how does natural selection operate in natural populations. To address the first problem, I have conducted a theoretical investigation into the evolution of control and the distribution of mutations in a simple system of interacting genes, a linear metabolic pathway. I found that control is distributed unevenly between enzymes, with upstream enzymes possessing the greatest control and accumulating the most beneficial mutations during adaptive evolution. To address the second problem, I investigated the evolution of copper tolerance in the common yellow monkeyflower, Mimulus guttatus. I genetically mapped a major locus controlling copper tolerance, Tol1. A Dobzhansky-Muller incompatibility was hypothesized to also be controlled by Tol1, however, we have demonstrated that it maps to another, tightly linked locus, Nec1. Finally, we investigated the parallel evolution of copper tolerance in multiple new discovered mine populations. We found that copper tolerance has evolved in parallel multiple times via at least two distinct physiological mechanisms. In four mine populations, there was a strong signal of selection at markers linked to Tol1, implying that copper tolerance has evolved via the same genetic mechanisms in these populations.</p> / Dissertation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Objetivo: Avaliar o efeito da intervenção dietética individualizada sobre o diagnóstico nutricional e controle metabólico em diabéticos tipo 2 sedentários Casuística e Métodos: Trata-se de um ensaio clínico controlado e prospectivo com 80 adultos, de ambos dos sexos, com Diabetes Mellitus tipo 2 divididos em GI (grupo intervenção: 40 indivíduos submetidos à intervenção dietética e a utilização de hipoglicemiante) e GC (grupo controle: 40 indivíduos submetidos à medicação hipoglicemiante). Foi realizada intervenção dietética individualizada por três meses baseando-se nas recomendações da American Diabetes Association (2002). Foram analisadas as variáveis antropométricas: massa corporal total (MCT), estatura com determinação do Índice de Massa Corporal (IMC) e perímetro da cintura (PC); as variáveis bioquímicas glicemia, colesterol total, LDL-colesterol, HDL-colesterol, triglicerídeos (TG) e hemoglobina glicada (HbA1c) e as variáveis dietéticas energia, proteínas, carboidratos, lipídeos, colesterol e fibras alimentares. Para estatística inferencial foi utilizado o Anova two-way com nível de significância de 95%. Resultados: Na análise intergrupos, o GC apresentou aumento nas variáveis: MCT (&#916;%=0,78; p=0,014), IMC (&#916;%=0,76; p=0,012), PC (&#916;%=0,75; p=0,019) enquanto que o GI apresentou redução nas variáveis: MCT (&#916;%=-3,71; p<0,001), IMC (&#916;%=-3,77; p<0,001), PC (&#916;%=-3,98; p<0,001). Na comparação da média do IR intergrupos, observou-se diferença nas variáveis: energia (p<0,001), lipídeos (p=0,012), gorduras saturadas (p<0,001); colesterol dietético (p=0,006); fibras alimentares (p=0,001); glicemia (p<0,001), colesterol total (p<0,001), LDL-colesterol (p<0,001) e HbA1c (p<0,001).Conclusão: A intervenção dietética foi eficiente em melhorar o perfil antropométrico e o controle metabólico dos diabéticos tipo 2 sedentários. / Objective: To evaluate the effect of individualized dietary intervention on nutritional diagnosis and metabolic control in sedentary subjects with type 2 diabetes. Materials and methods: This controlled clinical trial, investigated 80 adults, of both sexes, with type 2 diabetes. Patients were divided into intervention group (IG: 40 individuals subjected to intervention and hypoglycemic drug) and control group (CG: 40 individuals subjected only hypoglycemic drug). Individualized dietary intervention was conducted, for three months, based on the American Diabetes Association (2002). The anthropometric variables evaluated included: total body mass (TBM) and height to calculate body mass index (BMI), and waist circumference (WC): biochemical variables assessed were: blood glucose, total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides (TG), and glycated hemoglobin (HbA1c): In addition, the intake of energy, protein, carbohydrate, lipid, cholesterol, and dietary fibers. For inferential statistics two-way ANOVA was used with significant level of 95%.Results: In the intergroup analysis, the CG showed increase in TBM (&#916;%=0.78; p=0.014), BMI (&#916;%=0.76; p=0.012), WC (&#916;%=0.75; p=0.019); whereas IG decreased TBM (&#916;%=-3.71; p<0.001), BMI (&#916;%=-3.77; p<0.001), WC (&#916;%=-3.98; p<0.001). In comparing the mean RI intergroups, there was difference in the variables: energy/day (p<0.001), lipids (p=0.012), saturated fats (p<0.001), cholesterol (p=0.006), dietary fibers (p=0.001); blood glucose (p<0.001), total cholesterol (p<0.001), LDL-cholesterol (p<0.001), and HbA1c (p<0.001). Conclusions: The dietary intervention was efficiently the improvement the anthropometric and metabolic control of type 2 sedentary diabetics.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Objetivo: Avaliar o efeito da intervenção dietética individualizada sobre o diagnóstico nutricional e controle metabólico em diabéticos tipo 2 sedentários Casuística e Métodos: Trata-se de um ensaio clínico controlado e prospectivo com 80 adultos, de ambos dos sexos, com Diabetes Mellitus tipo 2 divididos em GI (grupo intervenção: 40 indivíduos submetidos à intervenção dietética e a utilização de hipoglicemiante) e GC (grupo controle: 40 indivíduos submetidos à medicação hipoglicemiante). Foi realizada intervenção dietética individualizada por três meses baseando-se nas recomendações da American Diabetes Association (2002). Foram analisadas as variáveis antropométricas: massa corporal total (MCT), estatura com determinação do Índice de Massa Corporal (IMC) e perímetro da cintura (PC); as variáveis bioquímicas glicemia, colesterol total, LDL-colesterol, HDL-colesterol, triglicerídeos (TG) e hemoglobina glicada (HbA1c) e as variáveis dietéticas energia, proteínas, carboidratos, lipídeos, colesterol e fibras alimentares. Para estatística inferencial foi utilizado o Anova two-way com nível de significância de 95%. Resultados: Na análise intergrupos, o GC apresentou aumento nas variáveis: MCT (&#916;%=0,78; p=0,014), IMC (&#916;%=0,76; p=0,012), PC (&#916;%=0,75; p=0,019) enquanto que o GI apresentou redução nas variáveis: MCT (&#916;%=-3,71; p<0,001), IMC (&#916;%=-3,77; p<0,001), PC (&#916;%=-3,98; p<0,001). Na comparação da média do IR intergrupos, observou-se diferença nas variáveis: energia (p<0,001), lipídeos (p=0,012), gorduras saturadas (p<0,001); colesterol dietético (p=0,006); fibras alimentares (p=0,001); glicemia (p<0,001), colesterol total (p<0,001), LDL-colesterol (p<0,001) e HbA1c (p<0,001).Conclusão: A intervenção dietética foi eficiente em melhorar o perfil antropométrico e o controle metabólico dos diabéticos tipo 2 sedentários. / Objective: To evaluate the effect of individualized dietary intervention on nutritional diagnosis and metabolic control in sedentary subjects with type 2 diabetes. Materials and methods: This controlled clinical trial, investigated 80 adults, of both sexes, with type 2 diabetes. Patients were divided into intervention group (IG: 40 individuals subjected to intervention and hypoglycemic drug) and control group (CG: 40 individuals subjected only hypoglycemic drug). Individualized dietary intervention was conducted, for three months, based on the American Diabetes Association (2002). The anthropometric variables evaluated included: total body mass (TBM) and height to calculate body mass index (BMI), and waist circumference (WC): biochemical variables assessed were: blood glucose, total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides (TG), and glycated hemoglobin (HbA1c): In addition, the intake of energy, protein, carbohydrate, lipid, cholesterol, and dietary fibers. For inferential statistics two-way ANOVA was used with significant level of 95%.Results: In the intergroup analysis, the CG showed increase in TBM (&#916;%=0.78; p=0.014), BMI (&#916;%=0.76; p=0.012), WC (&#916;%=0.75; p=0.019); whereas IG decreased TBM (&#916;%=-3.71; p<0.001), BMI (&#916;%=-3.77; p<0.001), WC (&#916;%=-3.98; p<0.001). In comparing the mean RI intergroups, there was difference in the variables: energy/day (p<0.001), lipids (p=0.012), saturated fats (p<0.001), cholesterol (p=0.006), dietary fibers (p=0.001); blood glucose (p<0.001), total cholesterol (p<0.001), LDL-cholesterol (p<0.001), and HbA1c (p<0.001). Conclusions: The dietary intervention was efficiently the improvement the anthropometric and metabolic control of type 2 sedentary diabetics.

Made available in DSpace on 2016-12-06T17:07:11Z (GMT). No. of bitstreams: 1 Dissertacao Lucieli Cambri.pdf: 576726 bytes, checksum: 2f4d7c6056c88929e5f180b6d53cc248 (MD5) Previous issue date: 2007-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose of the study was to analyze the cardiac autonomic modulation and the metabolic central during the rest and the physical exercise (PE) in subjects with type 2 diabetes. The group of study was composed by 22 volunteers of both sexes, sedentary, with ages between 40 and 65 years. The PE program was constituted of 3 weekly sessions, during 12 weeks, composed by walking or weight resisted exercise. They had data collected given reference to antropometric variables, biochemical variables, blood presssure and heart rate variability (HRV) in rest, capillary glycemia before and after one of the weekly sessions of PE. The referring collections of anthropometric and biochemical variables were remade after 6 and 12 weeks of PE. A walked gradual test was submitted for identification of the of HRV threshold (HRVT). The results shows that 63.6% and 89% of the evaluated ones were classified as obese as the matter of body mass index and corporal %fat (%FC) respectively. Analyzing the biochemical results, it was verified that 87.5% of the individuals had presented an increase in total cholesterol (TC) and 72.7% in triglycerides (TG). Moreover, 68.2% of the evaluated ones had presented reduced levels of HDL and glycated hemoglebin (Alc) above 7%. As well as, 87.5% had presented high LDL. During correlation analysis it was observed that TC, TG, HDL and Alc were the biochemical variables most influenced by the morphologic variables. The physiological and biochemical variables which had presented significant correlations with the HRV of rest were systolic blood pressure, heart rate (HR) of rest and fasting glycemia. The waist-to-hip ratio and the HDL had presented significant associations with the HR of rest. The average of the capillary glycemia reduced significantly. None of the morphologic variables had reduced significantly, as a chronic effect of the training, although the abdominal circunference, the sum of skinfolds and %FC had reduced. Only the HDL had presented an effect of the training. However, despite the other biochemical variables didn t present significant reductions, some subjects have passed from the inadequate condition to an adequate adjusted condition. The HRVT, based on the criteria of Lima & Kiss (1999) and Tulppo et al. (1998), was identified in all the subjects. However, based on the linear regression criteria, it was not possible to be identified in 4 subjects. There was no difference between the different criteria used to determine the HRTV. It was verified significant associations between the HRV of rest and intensity in the HRVT, using the criteria of Lima & Kiss (1999) and the HR of rest with the decreased percentage of the HR in the 5º minute of recovery. From the results obtained it is suggested that some morphological variables can influence biochemical parameters. As well as morfo-physiological and biochemical variables in the cardiac autonomic modulation. And still, the PE presents a favorable acute effect under capillary glycemia and a favorable chronic effect under morphological and biochemical variables. In addition to that, there were evidences that the HRVT might have applicability in the adequacy of training loads. / Este trabalho teve por objetivo analisar a modulação autonômica cardíaca e o controle metabólico durante o repouso e o exercício físico ÇEP) em diabéticos tipo 2. O grupo de estudo foi composto por 22 voluntários de ambos os sexOs, sedentários, com idades entre 40 e 65 anos. O programa de HP foi constituído de 3 sessões semanais, durante 12 semanas, compostas por caminhada ou exercícios resistidos com pesos. Foram coletados dados referentes as variáveis antropométricas e bioquímicas, pressão arterial e variabilidade da freqüência cardíaca (VFC) em repouso, e glicemia capilar antes e após uma das sessões semanais de EF. As coletas referentes as variáveis antropométricas e bioquímicas foram refeitas após 6 e 12 semanas de EF. Foi realizado um teste progressivo de caminhada para identificação do limiar de variabilidade da freqüência cardíaca (LiVFC). A partir dos resultados observou-se que 63,6% e 89% dos avaliados classificam-se como obesos no que se refere ao índice de massa corporal e ao %gordura corporal (%GC) respectivamente. Quanto aos resultados bioquímicos, verificou.e que 87,5% dos indivíduos apresentaram colesterol total (CT) e 72,7% triglicerídeos (TG) elevados, Além disso, 68,2% dos avaliados apresentaram níveis de HDL reduzidos e hemoglobina glicada (Alc) acima de 7%. Assim como, 87,5% apresentaram LDL elevados. Pela análise de correlação, o CT, TG, HDL e Alc foram as variáveis bioquímicas mais influenciadas pelas variáveis morfológicas. As variáveis fisiológicas e bioquímicas que apresentaram correlações significativas com a VFC de repouso foram pressão arterial sistólica, freqüência cardíaca (FC) de repouso e glicemia de jejum. A relação cintura quadril e a HDL apresentaram associações significativas com a FC de repouso. A média da glicemia capilar reduziu significativamente. Nenhuma das variáveis morfológicas reduziram significativamente, como efeito crônico do treinamento, com tendência de redução da circunferência abdominal, o somatório das dobras cutâneas e o %GC. Somente a HDL sofreu efeito do treinamento. Contudo, apesar das demais variáveis bioquímicas não terem apresentado reduções significativas, vários sujeitos passaram das condições de controle inadequado para adequado. O LiVFC, pelo critério de Lima & Kiss (1999) e de Tulppo et al. (1998), foi identificado em todos os sujeitos. Contudo, pelo critério de regressão linear não foi possível identificar em 4 sujeitos. Não houve diferença entre os critérios para determinação do LiVFC. Verificou-se associações significativas entre a VFC de repouso e intensidade no LiVFC, pelo critério de Lima & Kiss (1999) e a FC de repouso com o percentual de queda da FC no 5º minuto de recuperação. Assim, sugere-se que determinadas variáveis morfológicas estão associadas parâmetros bioquímicos e que variáveis morfo-fisiológicas e bioquímicas podem ser determinantes na modulação autonômica cardíaca. E ainda, o EF apresenta efeito agudo favorável na glicemia capilar e crônico nas variáveis morfológicas e bioquímicas. Além da obtenção de evidências de que o LiVFC pode ter aplicabilidade na adequação das cargas de treinamento.

Using data from a purposive sample of 78 parents of children with type 1 diabetes, relationships were examined between the level of metabolic control of the child with diabetes (as measured by the HbA1c percentage), parents' marital conflict, caregiver burden, and use of psychological control. Also explored were family income and the education levels of mothers and fathers. Differences between mothers and fathers were also considered. Better metabolic control (lower HbA1c) was related to lower levels of fathers' caregiver burden. Marital conflict was also associated with mothers' and fathers' caregiver burden. Finally, mothers' caregiver burden predicted mothers' use of psychological control, and fathers' caregiver burden predicted fathers' use of psychological control. Fathers' paths were stronger from marital conflict to caregiver burden and from caregiver burden to psychological control than the mothers' paths. Only fathers had a significant path from HbA1c to caregiver burden.

Thesis (PhD (Biochemistry))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: The multiplication of cells proceeds through consecutive phases of growth and division (G1, S, G2 and M phases), in a process known as the cell cycle. The transition between these phases is regulated by so-called checkpoints, which are important to ensure proper functioning of the cell cycle. For instance, mutations leading to faulty regulation of the G1/S transition point are seen as one of the main causes of cancer. Traditionally, models for biological systems that show rich dynamic behavior, such as the cell cycle, are studied using dynamical systems analysis. However, using this analysis method one cannot quantify the extent of control of an individual process in the system. To understand system properties at the process level, one needs to employ methods such as metabolic control analysis (MCA). MCA was, however, developed for steady-state systems, and is thus limited to the analysis of such systems, unless the necessary extensions would be made to the framework. The central question of this thesis focuses on quantifying the control in mathematical models of the G1/S transition by the individual cell cycle processes. Since MCA was never applied to the cell cycle, several new methods needed to be added to the framework. The most important extension made it possible to follow and quantify, during a single cell cycle, the control properties of the individual system processes. Subsequently, these newly developed methods were used to determine the control by the individual processes of an important checkpoint in mammalian cells, the restriction point. The positioning of the restriction point in the cell cycle was distributed over numerous system processes, but the following processes carried most of the control: reactions involved in the interplay between retinoblastoma protein (Rb) and E2F transcription factor, reactions responsible for the synthesis of Delayed Response Genes and Cyclin D/Cdk4 in response to growth signals, the E2F dependent Cyclin E/Cdk2 synthesis reaction, as well as the reactions involved in p27 formation. In addition it was shown that these reactions exhibited their control on the restriction point via the Cyclin E/Cdk2/p27 complex. Any perturbation of the system leading to a change in the restriction point could be explained via its e ect on the Cyclin E/Cdk2/p27 complex, showing a causal relation between restriction point positioning and the concentration of the Cyclin E/Cdk2/p27 complex. Finally, we applied the new methods, with a modular approach, to compare a number of cell cycle models for Saccharomyces cerevisiae (budding yeast) and mammalian cells with respect to the existence of a mass checkpoint. Such a checkpoint ensures that cells would have a critical mass at the G1/S transition point. Indeed, in budding yeast, a correction mechanism was observed in the G1 phase, which stabilizes the size of cells at the G1/S transition point, irrespective of changes in the specific growth rate. This in contrast to the mammalian cell cycle models in which no such mass checkpoint could be observed in the G1 phase. In this thesis it is shown that by casting specific questions on the regulation and control of cell cycle transition points in the here extended framework of MCA, it is possible to derive consensus answers for subsets of mathematical models. / AFRIKAANSE OPSOMMING: Die selsiklus bestaan uit agtereenvolgende groei- en delingsiklusse wat tot selvermeerdering lei. Die siklus word gekenmerk deur onderskeie fases (G1, S, G2 en M) wat deur sogenaamde beheerpunte gereguleer word. Hierdie beheerpunte verseker dat selvermeerdering nie ongekontroleerd kan plaasvind nie en mutasies wat lei tot foutiewe regulering van die G1/S transisiepunt word as een van die hoofoorsake van kanker beskou. Die hoofdoel van hierdie studie was om die beheer wat selsiklusprosesse op die G1/S transisie uitoefen met behulp van wiskundige modelle te kwantifiseer. Omdat biologiese sisteme soos die selsiklus ryk dinamiese gedrag vertoon, word hulle tradisioneeldeur middel van dinamiese sisteemanalise bestudeer. Die analisemetode beskik egter nie oor die vermoë om die hoeveelheid beheer wat afsonderlike sisteemprosesse op 0n sisteemeienskap uitoefen te kwantifiseer nie. Om sisteemeienskappe op prosesvlak te verstaan moet metodes soos metaboliese kontrole analise (MKA) ingespan word. MKA was egter ontwikkel om sisteme in 0n bestendige toestand te analiseer en aangesien MKA nog nooit vantevore vir selsiklus analises gebruik was nie, moes nuwe MKA tegnieke gedurende die studie ontwikkel word. Die belangrikste van die metodes maak dit moontlik om beheer (soos uitgeoefen deur die onderskeie sisteemprosesse) oor 0n enkele selsiklus na te volg en te kwantifiseer. Die nuut-ontwikkelde metodes was vervolgens gebruik om te bepaal hoe een so 0n beheerpunt in soogdierselle - die restriksiepunt - deur die onderskeie sisteemprosesse beheer word. Die studie het aangedui dat die posisie van die restriksiepunt tydens die selsiklus deur ’n verskeidenheid sisteemprosesse beheer word. Die bevinding was dat vier prosesse beduidend meer beheer op die posisie van die restriksiepunt uitoefen: Reaksies wat betrekking het op die wisselwerking tussen retinoblastoma proteïen (Rb) en E2F transkripsiefaktor; reaksies verantwoordelik vir die sintese van vertraagde responsgene en Siklien D/Cdk4 in respons tot groeiseine; die E2F afhanklike Siklien E/Cdk2 sintesereaksie; sowel as die reaksies betrokke in p27 vorming. Daar was ook aangetoon dat hierdie reaksies hul beheer op die posisie van die restriksiepunt deur die Siklien E/Cdk2/p27 kompleks uitoefen, siende enige sisteemversteuringe (wat tot veranderinge in die restriksiepuntposisie aanleiding gee) deur veranderinge in die kompleks verklaar kon word - 0n observasie wat aandui dat daar 0n kousale verhouding is tussen die posisie van die restriksiepunt en die Siklien E/Cdk2/p27 kompleks. Die nuut-ontwikkelde metodes was verder gebruik om 0n verskeidenheid selsiklusmodelle van Saccharomyces cerevisiae (bakkersgis) en soogdierselle met 0n modulêre aanpak te vergelyk om te bepaal of daar 0n massa beheerpunt in beide soogdier- en bakkersgisselle bestaan. Daar word gepostuleer dat hierdie beheerpunt verseker dat selle 0n kritiese massa by die G1/S transisiepunt bereik. Die resultate van die studie dui daarop dat bakkersgis, anders as soogdierselle, oor so 0n korreksiemeganisme beskik. Die meganisme stabiliseer die grootte van selle in die G1 fase ondanks veranderinge in die groeitempo van die selle, sodat massa homeostaties by die G1/S transisiepunt gehandhaaf word. Die studie het getoon dat moeilike vrae met betrekking tot die selsiklus beantwoord kan word deur van wiskundige modelle gebruik te maak en die probleme in die nuut-ontwikkelde metaboliese kontrole analise raamwerk te giet.

Les événements de diversification adaptative sont des éléments primordiaux de l'évolution. En effet, ils engendrent des innovations phénotypiques telles que la colonisation de nouvelles niches écologiques et au final, la spéciation. Afin d'étudier les ressorts écologiques et moléculaires de la diversification adaptative, nous utilisons la plus longue des expériences d'évolution en cours. Depuis 1988, soit plus de 60 000 générations, douze populations indépendantes issues d'un ancêtre commun d'Escherichia coli sont propagées quotidiennement dans un milieu minimum comportant une faible quantité de glucose.Un événement unique de diversification s'est produit dans une des 12 populations (Ara–2). Deux lignées de phénotypes différents sont apparues après environ 6500 générations, les S pour «Small» et les L pour «Large», chacune présentant des tailles cellulaires différentes. Les deux lignées coexistent grâce à une sélection négative dépendant de la fréquence qui favorise la lignée la plus rare et permet de supplanter sa concurrente; ainsi, aucune des deux lignées ne s'éteint. Avant l’événement de diversification, la population Ara–2 a développé un phénotype hypermutateur suite à la mutation d'un gène de réparation de l'ADN. L'objectif de cette thèse est de caractériser les mécanismes écologiques, physiologiques et moléculaires sous-tendant l'émergence et la coexistence des lignées S et L.En premier lieu, nous avons utilisé un ensemble d'expériences d'évolution in vivo et in silico afin de déterminer les moteurs écologiques et physiologiques de l'émergence de ce polymorphisme. Plusieurs mécanismes écologiques, incluant les compromis (trade-off évolutifs), la saisonnabilité et les déplacements de caractères interviennent dans l'émergence et la persistance de la diversité au long terme. Nous avons montré que la lignée L, en produisant de l'acétate, créait une nouvelle opportunité écologique exploitée par les S. De plus, au cours du temps, les S et les L s'adaptent à leur niche écologique, respectivement l'acétate et le glucose.En second lieu, nous avons cultivé les S et les L séparément pour éliminer la compétition entre les deux lignées. Dans ces conditions, il y a perte des interactions dépendantes de la fréquence entre les S et les L. Ceci démontre l'importance de la compétition dans le maintien du polymorphisme.En troisième lieu, nous avons combiné des approches génétiques, physiologiques et biochimiques pour déterminer le rôle, dans l'émergence du polymorphisme, d'une mutation spécifique aux S survenant dans le gène arcA, codant un régulateur global. Nous avons montré que l'allèle évolué de arcA augmentait la transcription de gènes du métabolisme de l'acétate dans la lignée S. Au cours de cette étude, nous avons identifié une mutation supplémentaire dans le gène acs, impliqué dans le métabolisme de l'acétate, intervenant dans l'émergence de la lignée S. Nous avons aussi démontré que ces deux mutations étaient favorables à la lignée S au début de son émergence, puis que des mutations plus tardives agissaient de façon épistatiques avec les allèles évolués de acs et de arcA. Ainsi, ces résultats démontrent que l'établissement et le maintien du polymorphisme des S et des L est un processus en plusieurs étapes nécessitant des interactions épistatiques entre plusieurs mutations.En quatrième lieu, nous avons identifié la dynamique au long terme des taux de mutations dans cette population. L'apparition et l'invasion rapide du phénotype hypermutateur est suivie d'une réversion complète mais indépendante dans chacune des lignées S et L.L'émergence d'un polymorphisme bactérien durable reflète une restructuration complexe des réseaux métaboliques et de régulation dans ces lignées qui co-existent, ce qui aboutit à l'apparition et à l'exploitation de nouvelles opportunités écologiques. La compétition et l'évolution de l'utilisation de ressources différentes sont des forces sélectives permettant le maintien du polymorphisme. / Diversification events are central issues in evolution since they generate phenotypic innovation such as colonization of novel ecological niches and, ultimately, speciation. To study the ecological and molecular drivers of adaptive diversification, we used the longest still-running evolution experiment. Twelve independent populations are propagated in a glucose limited minimal medium from a common ancestor of Escherichia coli by serial daily transfers since 1988 for more than 60,000 generations. In one of the twelve populations, called Ara–2, a unique diversification event occurred: two phenotypically-differentiated lineages, named S (Small) and L (Large) according to their cell size, emerged from a common ancestor at ~ 6500 generations. The two lineages co-exist ever since, owing to negative frequency-dependent selection whereby each lineage is favored and invades the other when rare, such that no lineage gets extinct. Moreover, and before the split between the two S and L lineages, the population Ara–2 evolved a hypermutator phenotype, owing to a defect in a DNA repair gene. The objective of this thesis is to characterize the ecological, physiological and molecular mechanisms that allowed the emergence and stable co-existence of the S and L lineages.First, we used a combination of in vivo and in silico experimental evolution to determine the ecological and physiological drivers of the emergence of the polymorphism. Several ecological mechanisms including tradeoff, seasonality and character displacement are involved in the emergence and long-term persistence of diversity. In particular, we showed that the L lineage secretes acetate which generates a new ecological opportunity that the S lineage exploited. In addition, the S and L lineages became fitter and fitter over time in their respective ecological niches, respectively acetate and glucose. Second, we propagated S and L clones separately to remove competition between the two lineages. In these conditions, frequency-dependent interactions between the S and L clones evolved separately were completely abolished, revealing the importance of competition in the maintenance of the polymorphism. Third, we combined genetic, physiological and biochemical approaches to determine the role of an S-specific mutation that was previously found in arcA, encoding a global regulator, in the emergence of the S and L polymorphism. We showed that the evolved arcA allele conferred to the S lineage the capacity to growth on acetate by increasing the transcription of target genes involved in acetate consumption. During this study, we found an additional mutation, in the acs gene involved in acetate metabolism, that was also involved in the emergence of the S lineage. We further showed that these two mutations were favorable to the S lineage early during its emergence, and that other mutations occurred later that interacted epistatically with the acs and arcA evolved alleles. Therefore, these data showed that the establishment and further maintenance of the S and L polymorphism was a multi-step process involving epistatic interactions between several mutations. Fourth, we identified the long-term dynamics of mutation rates in this divergent population. A first early rise of a hypermutator was followed by a full reversion of this mutator state twice independently in each of the two S and L lineages.The emergence of a long-term bacterial polymorphism reflects a complex restructuration of the metabolic and regulatory networks in the co-existing lineages, resulting in the generation and exploitation of a new ecological opportunity. Competition and evolution of divergent resource consumption were the selective forces driving the maintenance of the polymorphism.

Background: Specialized adult care of phenylketonuria (PKU) patients is of increasing importance. Adult outpatient clinics for inherited errors of metabolism can help to achieve this task, but experience is limited. Ten years after establishment of a coordinated transition process and specialised adult care for inherited metabolic diseases, adult PKU care was evaluated with respect to metabolic control, therapy satisfaction, life satisfaction, sociodemographic data, economical welfare as well as pregnancy outcome. Methods: All PKU patients transferred from paediatric to adult care between 2005 and 2015 were identified. A retrospective data analysis and a cross-sectional survey in a sub-cohort of 30 patients including a questionnaire for assessing quality of life (FLZm) were performed as a single-centre investigation at the metabolic department of the University Hospital Leipzig, Germany. For statistical analysis, Mann-Whitney-U-test, t-test for independent samples, ANOVA and chi square test were used as appropriate. Results: 96 PKU patients (56 females/40 males; median age 32 years, range 18–62) were included. In the last 3-year period, 81 % of the transferred patients still kept contact to the adult care centre. Metabolic control was stable over the evaluation period and dried blood phenylalanine concentrations mostly remained within the therapeutic range (median 673.0 μmol/l, range 213.0–1381.1). Sociodemographic data, economical welfare and life satisfaction data were comparable to data from the general population. However, differences could be revealed when splitting the cohort according to time of diagnosis and to management during childhood. 83 % of the PKU adults were satisfied with the transition process and current adult care. 25 completed pregnancies were supervised; three newborns, born after unplanned pregnancy, showed characteristic symptoms of maternal PKU syndrome. Conclusions: Continuous care for adult PKU patients in a specialized outpatient clinic is successful, leading to good to satisfactory metabolic control and social outcomes. Uninterrupted good metabolic treatment throughout childhood and adolescence positively influences educational, professional and economic success in later life. Further effort in specialized paediatric and adult metabolic care is needed to prevent loss of follow-up and to support the recommended life-long treatment and/or care.

In recent years, streams draining agricultural land has been suggested to exhibit high carbon dioxide (CO2) concentrations when compared to streams draining other land-types. The transport of carbon from land to ocean is mainly occurring through the chain of inland waters, and with agricultural land today representing 40% of all continental area many of these inland waters are influenced by agricultural land. The aim of this study was to improve the understanding of CO2 dynamics and its control in agricultural streams. Continuous data was collected from two catchments of different scales, near the city of Uppsala, Sweden. Both catchments are typical low-land catchments largely dominated by agricultural land. The measured CO2 concentrations were analyzed to find temporal variations and differences in dynamics between the catchments. The interplay between CO2 and parameters such as dissolved oxygen, discharge and conductivity were analyzed to determine the main drivers for CO2 dynamics. The findings show supersaturation of CO2 concentration during the full length of the measurement periods, with mean CO2 concentrations higher than what have been observed in streams draining other land-type catchments. Diel CO2 cycles were found throughout most of the measurement periods, where manual measurements were conducted to confirm these findings. The diel CO2 patterns were suggested to be heavily dependent on in-situ metabolic control while hydrological factors, such as sufficient discharge, seemed to be needed to produce a good diel CO2 signal. CO2 build-up is suggested to occur in the catchment soil and, when flushed out after rain events, result in an increasing CO2 concentration. This might be one important driver for the high levels in CO2 concentration found in the streams during summer and autumn. Analysis of the catchment areas suggest the percentage of agricultural land and the size of the catchment areas had an impact on hydrology, both for sufficient water flow to exist but also for the CO2 response after rain events. More research is encouraged, where more parameters should be investigated, such as groundwater inputs and carbonate precipitation. / Bäckar som dränerar åkermark har under de senaste åren blivit mer uppmärksammade på grund av nya studier som visat att dessa bäckar tenderar att ha högre CO2-koncentration än bäckar som dränerar andra marktyper. Idag utgör cirka 40% av all kontinentalyta åkermark, då den huvudsakliga transporten av kol från land till hav sker genom sammankopplade vattendrag är därav en förståelse av åkermarkers dränering till bäckar av stor betydelse. Syftet med studien var att förbättra förståelsen av CO2-dynamiken och dess påverkan på bäckar i jordbruksdominerade avrinningsområden. Kontinuerlig data samlades in, samt erhölls från tidigare mätningar, från två avrinningsområden med olika storlekar och markfördelningar nära Uppsala. Båda avrinningsområdena var typiska låglands- avrinningsområden som dominerades av åkermark. Data för CO2-koncentration analyserades för att hitta kort- och långsiktiga variationer i CO2-dynamiken samt undersöka hur denna dynamik skiljer sig mellan avrinningsområden med olika storlek och markfördelning. Samspelet mellan CO2 och parametrar såsom vattenlösligt syre, vattenföring och konduktivitet analyserades för att hitta drivkrafter bakom CO2-dynamiken. Resultatet visar att de undersökta bäckarna var övermättade med CO2 under hela mätperioden, samt att medelkoncentrationerna som uppmättes var högre än vad som observerats i bäckar som dränerar andra landtyper. En dygnsvariation av CO2 observerades under större delar av mätperioderna, manuella prover utfördes för att stärka denna data. Den observerade dygnscykeln av CO2-koncentrationen konstaterades korrelera med den in-situ metaboliska kontrollen medan hydrologiska faktorer, såsom ett tillräckligt högt vattenflöde, visade sig var viktigt för att en CO2-dygnscykel ska existera. De mycket höga toppar av CO2-koncentration som observerats under mätningarna tros bero på ackumulering av CO2 i avrinningsområdenas marker, vilket under nederbörd utarmas och transporteras till bäcken. Vid jämförelse av de två avrinningsområdena föreslogs den procentuella andelen åkermark och storleken av avrinningsområdet ha en stor påverkan på hydrologin, både för att ett tillräckligt vattenflöde ska existera men också för CO2-responsen vid större nederbördsmängder. Mer forskning behövs där fler parametrar börs ta i beaktning, till exempel in-situ karbonutfällning och inflöde av CO2 via grundvatten, för att få en bättre bild över åkermarkens påverkan på CO2-dynamik i bäckar.

The purpose of this integrated review of the literature was to explore the effects of social support on diabetes-related stress, conflict, and metabolic control in adolescents with type 1 diabetes mellitus (T1DM). Social support was examined in four subgroups: adolescents with T1DM, family caregivers, peers, and teachers. Relevant findings in the literature revealed a significant deficiency of research devoted to adolescent males with diabetes as well as fathers as primary and secondary caregivers. Studies highlighted the importance of fostering autonomy and positive self-image in adolescents with T1DM and described effective interventions to improve diabetes-related stress, reduce disease-related conflict, and improve metabolic control. Findings suggested that nurses caring for adolescents with T1DM and their families should foster positive, open communication, while identifying barriers to problem solving, coping, stress, and optimal glycemic control. Interventions that educate caregivers and peers on how to better communicate and provide support are critical in fostering positive psychological and physiological outcomes in the adolescent with T1DM. The findings of this study may provide guidance in the way that nurses assess, identify, and counsel adolescents with TIDM regarding their disease management and access to support systems.