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Coming dissertations at Uppsala university

  • Lead-free Metal Halide based Solar Cells Author: Huimin Zhu Link: Publication date: 2019-09-12 11:11
  • Carbon Dioxide in Inland Waters : Drivers and Mechanisms Across Spatial and Temporal Scales Author: Anna Cecilia Nydahl Link: Publication date: 2019-09-12 11:09

    Inland waters are an essential component of the global carbon cycle as they are very active sites for carbon transformation processes. Much of this carbon is transformed into the greenhouse gas carbon dioxide (CO2) and emitted into the atmosphere. The biogeochemical and hydrological mechanisms driving CO2 concentrations in inland waters are manifold. Although some of them have been studied in detail, there are still knowledge gaps regarding the relative importance of the different CO2-driving mechanisms, both on a spatial and a temporal scale. The main aim of this thesis was to fill some of the knowledge gaps by studying long- and short-term effects of enhanced dissolved organic carbon (DOC) concentrations on surface water partial pressure of CO2 (pCO2) as well as to investigate both internal (i.e., within the water body) and external (i.e., catchment) drivers of pCO2 in inland waters. Based on analyses of long-term data from more than 300 boreal lakes and streams and on results from two mesocosm experiments as well as a detailed catchment study, one of the main results of the thesis was that DOC concentrations were, on a temporal scale, generally uncoupled to pCO2. Indeed, additions of allochthonous DOC to lake water could result in increased pCO2 in waters but not as originally expected by stimulation of bacterial activity but instead by light driven suppression of primary production, at least in mesotrophic waters. Changes in the carbonate system was also found to be a main driver for surface water pCO2. Finally, also external processes such as groundwater inputs contributed substantially to variations of surface water pCO2. In a detailed study on carbon in groundwater, pCO2 in groundwater was found to decrease with soil depth and correlated negatively with pH, which increased with soil depth. Conclusively, this thesis show that pCO2 does not follow the trends of increased DOC in boreal surface waters but instead correlates with changes in primary production and shifts in the carbonate system. Additionally, the dominating mechanisms driving pCO2 clearly differ between lakes and streams. Consequently, simulations of future CO2 dynamics and emissions from inland waters cannot rely on DOC concentrations as a pCO2 predictor, but rather need to incorporate several pCO2 driving mechanisms, and consider the difference between lakes and streams.

  • Therapy-resistant enuresis : In search of new therapies and prognostic markers Author: Elisabet Lundmark Link: Publication date: 2019-09-12 10:48

    A large minority of children with enuresis do not respond to treatment with either desmopressin or the enuresis alarm. Anticholinergics have not proven as successful as expected. The fourth evidence-based treatment of enuresis, the tricyclic antidepressant imipramine, is cardiotoxic when overdosed, which has led to diminished use. Since the long-term consequences of enuresis are potentially grave it is important that effective treatments of therapy-resistant enuresis are found.

    When investigating the enuretic child a full voiding-chart - in addition to the case history - is the method of choice. However, there is no robust evidence that daytime voiding chart data actually do predict nocturnal detrusor function.

    The aim of this thesis was to determine whether there is a role for the noradrenergic antidepressant reboxetine in the treatment of therapy-resistant enuresis, and whether anamnestic data and the voiding chart provides prognostic information regarding response to treatment with anticholinergics and antidepressants respectively in therapy-resistant patients.

    In a retrospective evaluation of 61 children who for humanitarian purposes had been treated with reboxetine 32(52%) responded to this treatment, 21 of them after desmopressin had been added. We then proceeded with a randomized placebo-controlled study with 18 patients, in which the reduction of wet nights was much better with either reboxetine in monotherapy or in combination with desmopressin than during the placebo period (p=0.002). However, no patient achieved complete dryness. No prognostic markers for therapy-response were found in either of these studies.

    In the randomized study we also sought to investigate whether reboxetine had any statistically significant effect on voiding-chart data. No such effect was found, but in respect to this secondary aim the sample size was too small. Nonetheless , this led to the speculation whether reboxetine exerts its antienuretic effect via modulation of arousal mechanisms.

    Prognostic markers were sought in a retrospective evaluation of 154 patients treated with anticholinergics or antidepressants, but few and inconsistent differences were found between the groups responding or not responding to the various treatment regimens, and this was true both for anamnestic and voiding chart data.

    In conclusion reboxetine seems to be an alternative in the treatment of enuretic children who have not responded to standard treatment, but further trials with higher doses and larger study populations are needed. The internationally recommended assessment of children with therapy-resistant enuresis does not seem to give the prognostic information intended.