Pharmacometrics is widely used in drug development. Models are developed to describe pharmacological measurements with data gathered from a clinical trial. The information can then be applied to, for instance, safely establish dose-response relationships of a substance. Glycated hemoglobin (HbA1c) is a common biomarker used by models within antihyperglycemic drug development, as it reflects the average plasma glucose level over the previous 8-12 weeks. There are five different nonlinear mixed-effects models that describes HbA1c-formation. They use different biomarkers such as mean plasma glucose (MPG), fasting plasma glucose (FPG), fasting plasma insulin (FPI) or a combination of those. The aim of this study was to compare their performances on a population and an individual level using model averaging (MA) and to explore if reduced trial durations and different treatment could affect the outcome. Multiple weighting methods were applied to the MA workflow, such as the Akaike information criterion (AIC), cross-validation (CV) and a bootstrap model averaging method. Results show that in general, models that use MPG to describe HbA1c-formation on a population level could potentially outperform models using other biomarkers, however, models have shown similar performance on individual level. Further studies on the relationship between biomarkers and model performances must be conducted, since it could potentially lay the ground for better individual HbA1c-predictions. It can then be applied in antihyperglycemic drug development and to possibly reduce sample sizes in a clinical trial. With this project, we have illustrated how to perform MA on the aforementioned models, using different biomarkers as well as the difference between model weights on a population and individual level.

This dissertation explores the structural modification of indigo into its rare cis form by substitution of a short organic bridge between the two indole nitrogen atoms. The synthesized N,N′-tethered cis-indigoids are assessed for their physicochemical properties in order to understand the effect of the organic tether on cis-indigoid systems. Three literature compounds containing “simple” tether structures are synthesized and subjected to complete characterization. Among them, alkyl group based cis-indigos, 2.5 and 2.6 exhibit similar absorption wavelengths as the parent indigo while oxalyl-tethered indigo 2.7 shows a large hypsochromic shift due to the strong electron-withdrawing nature of the oxalyl group. The electronics of the tether also affected the HOMO and LUMO energy levels; the oxalyl tether lowered both energy levels in comparison to the alkyl tethers. However, the indigoid co-planarity was strongly affected by the ring size from the tether rather than electronics. A new tethered cis-indigo structure type was discovered in reactions involving quinones. This new tether type consists of a 2,2′-dihydroindigo unit connected to the cis-indigo backbone through a central C–C bond of the former. Incorporation of the quinone moiety was observed in 3.2 where the final structure is comprised of two molecules of indigo and one naphthoquinone, while structures of 3.3 and 3.4 contained two indigoid units only. Investigation by CV revealed the strength of the quinone altered the early reaction intermediates. These dimeric cis-indigos show a small hypsochromic shift in the absorption compared to the parent indigo and relatively planar cis-indigoid backbone. 3.2 demonstrates rich redox behaviours. 3.3 and 3.4 display dynamic behaviours observed by solution VT 1H NMR spectroscopy. Oxalyl-tethered cis-Nindigo 4.6a and cis-indigo monoimine 4.7a were synthesized and compared with the indigoid counterpart 2.7 to examine the influence of the arylimine groups. Absorption wavelengths of the imine group containing species depended strongly on the electronics of the tether, yet the number of imine groups affected redox potentials. Protonation of 4.6a (to give H+oxalyl Nindigo 4.6aH+) causes a bathochromic shift in the absorption and allows for much easier reduction. The acidity (pKa) of 4.6aH+ is estimated between 3.6 – 4.46 in DMSO. A protonated cis-Nindigo derivative 4.9aH+ was obtained via reduction of the oxalyl group and is compared with 4.6aH+. / Graduate / 2022-08-13

This study uses the double-bounded bid elicitation format to estimate how much households in the Khalong-la-Lithunya wetland area (KWA) would be WTP (on top of monthly water bills) for wetland resource conservation, and test whether WTP significantly varies with the institution responsible for its conservation management. KWA was purposely selected on account of the critically important role it plays in securing water provisioning ecosystem services; a role that is currently threatened by proximate and ultimate factors hypothesised to be driven by its unrecognised economic value. WTP was thus elicited and compared when the governance institution was (i) the Ministry of Natural Resources, and (ii) a private environmental conservation agency that is currently active in Lesotho i.e. the Transformation Resource Centre (TRC). Purposive and simple random sampling methods were used to collect survey data from 204 households. Results show that respondents have high levels of factual knowledge about the threats to the sustainability of KWA. They also have attitudes, opinions, and perceptions that are receptive to a policy that improves the status quo. Mean WTP was M78.80 per household per month (UB M92.89 and LB M38.21) when the Ministry of Natural Resources was responsible for conservation management in KWA (equivalent to M 0.011 per litre or M0.21 per 20 litre jerry can), and M83.09 per household per month (UB M98.00 and LB M32.94) when TRC was responsible for conservation management in KWA (equivalent to M0.011 per litre or M0.22 per 20 litre jerry can). The null hypothesis of equality of the two mean WTP values was rejected at the 1 % level (t= 4.34 and p = 0.000), suggesting that institution responsible for conservation management in KWA significantly influences households' WTP. Double bounded models differentiated by institution responsible for conservation management in KWA were used to econometrically determine factors that influence households' WTP. Results show that WTP was positively related to the following variables: income, age, education, whether households had experienced seasonal water shortages, knowledge of health risks associated with water shortages, and gender (males had higher WTP). WTP was found to be negatively related to household size (the more the household members, the lower the WTP). These results were consistent with prior expectation and literature. Considering, also, that this study further used secondary sources to estimate that households, on average, spend about M300 per month on water (equivalent to M0.04 per litre or 0.80 per 20 litre jerry can), three key recommendations follow. First, subject to extensive stakeholder consultations, the Water and Sewerage Authority (WASA) of Lesotho should consider adding to the regular charge a resource conservation tax amounting to at least M0.011 per litre of water delivered to customers, i.e. instead of charging M0.04 per litre of water delivered, WASA should charge customers at least M0.051 per litre of water delivered. Second, WASA should consider instituting a policy that isolates the conservation charge from the M0.51 per litre, and explicitly invest it in mitigating the resource conservation challenges in KWA (i.e. the charge should be used to support activities that secure the sustainable water provisioning ecosystem services from KWA). Finally, WASA should consider engaging TRC directly in converting the proceeds from the conservation charge to tangible resource conservation outcomes in KWA, given that households expressed higher WTP when TRC was responsible for its conservation management. / Dissertation (MSc (Agric))--University of Pretoria, 2017. / Agricultural Economics, Extension and Rural Development / MSc (Agric) / Unrestricted

In dieser Arbeit wird die Herstellung und spektroelektrochemische Charakterisierung von Polymeren aus alkylsubstituierten Anilinderivaten beschrieben. Hierzu wird die zyklische Voltammetrie sowie als in situ-spektroskopische Methoden UV-vis-, FTIR- und Raman-Spektroskopie eingesetzt. Aus allen eingesetzten Monomeren lassen sich elektroaktive und elektrochrome Polymere herstellen. Bei der Mehrzahl der Polymere konnten in situ-Leitfähigkeitsmessungen durchgeführt werden, die eine intrinsische, vom Elektrodenpotential abhängige elektrische Leitfähigkeit zeigen. Der molekulare Aufbau innerhalb der Polymerketten wird durch FTIR- und Raman-Spektroskopie in Analogie zum Polyanilin identifiziert. Er ist wie beim Polyanilin vom Oxidationsgrad abhängig.

Investigation and testing of hydropneumatic suspension systems has previously been done at Scania between the year 1992 and 2000. Interest has aroused at Scania CV AB to further test a hydropneumatic suspension. The reason being the new ventures of decarbonised, clean, electrified, automatized and digitalised vehicles. If electrified trucks are to be adopted in the market as an alternative to trucks with combustion engines, solutions for this type of vehicle’s capacity need to be presented. The vehicle’s weight needs to be reduced; the effectiveness of the components needs to be increased and alternatives to increase battery storage needs to arise if it’s going match the traveling distance of a combustion engine. The mission of the project is to present an installation solution of a hydropneumatic suspension that retains the performance of the current air suspension. The presented material will contain CAD-models of all the brackets that will be designed to fit the suspension, as well as the placement in the vehicle assembly for said brackets. The results show that as for the front suspension the best solution is a placement of the hydraulic cylinders in front of the vehicles front axle. Furthermore the rear suspension is best suited for a placement of the hydraulic cylinders behind the vehicles rear axle. However it was concluded that the rear suspension will not be able to retain the current stroke of the vehicle without sacrificing its ground clearance. Parts of the suspension could however be terminated when the air suspension system was replaced by the hydropneumatic system namely: The front suspension anti-roll bar, shock absorbers, air springs and their coexisting brackets.

In dieser Arbeit wird die Herstellung und spektroelektrochemische Charakterisierung von Polymeren aus alkylsubstituierten Anilinderivaten beschrieben. Hierzu wird die zyklische Voltammetrie sowie als in situ-spektroskopische Methoden UV-vis-, FTIR- und Raman-Spektroskopie eingesetzt. Aus allen eingesetzten Monomeren lassen sich elektroaktive und elektrochrome Polymere herstellen. Bei der Mehrzahl der Polymere konnten in situ-Leitfähigkeitsmessungen durchgeführt werden, die eine intrinsische, vom Elektrodenpotential abhängige elektrische Leitfähigkeit zeigen. Der molekulare Aufbau innerhalb der Polymerketten wird durch FTIR- und Raman-Spektroskopie in Analogie zum Polyanilin identifiziert. Er ist wie beim Polyanilin vom Oxidationsgrad abhängig.

Purpose: The purpose of the study is to chart practitioners' views of an anonymous recruitment.    Method: To study our chosen phenomenon of anonymous recruitment, a case study has been employed to focus on a specific phenomenon, which we have approached through unstructured interviews. As the nature of our study is empirical, an inductive research approach with a qualitative research method has been used.  Conclusion: The study shows that practitioners who applied an anonymous recruitment method perceive that it provides several benefits. It has been demonstrated that the process contributes to a more objective, fair, and time-efficient talent acquisition by forcing a larger focus on a profile of demands. It also indicates an increase in diversity within the organization when implemented alongside a diversity mindset. Simultaneously, anonymous recruitment enhances the company's reputation and improves the inevitable gut-feeling in decision-making.

Shewanella spp. are model electroactive bacteria (EAB) and well-known for their broad metabolic capabilities and extracellular electron transfer (EET) properties, which allow them to utilize a diverse range of carbon substrates, such as formate, lactate, pyruvate, and amino acids. However, the majority of Shewanella spp. cannot metabolize glucose, a naturally occuring carbon and energy source. Here, we examine the electrode respiring potential of Shewanella chilikensis JC5T- and its coexistence with acetoclastic EAB, Geobacter sulfurreducens in glucose-fed microbial electrolysis cells (MECs) operated at a set anode potential condition of 0 V vs. Ag/AgCl. Chronoamperometry analysis revealed that the maximum current density was 0.04523 mA/cm2 (CE: 14.55%) in S-MEC (only S. chilikensis JC5T) and 0.299 mA/cm2 (CE: 53.85%) in CC-MEC (S. chilikensis JC5T and G. sulfurreducens) which is 6.6-folds higher in current density and 3.7-folds higher in coulombic efficiency than S-MEC. Cyclic voltammetry analysis demonstrates presence of biofilm and redox mediator for EET mechanisms. Metabolic analysis showed that S. chilikensis as a monoculture and co-culture with G. sulfurreducens can metabolize glucose and produce intermediates such as acetate, formate, and lactate. These intermediates are likely used to generate electrical current. Collectively, these results provide novel insights on electrode respiring properties of S. chilikensis and its coexistence with acetoclastic EAB, G. sulfurreducens to enhance the current density and coulombic efficiency from glucose-fed MEC.

With solar power and other renewables set to take over the market in the coming decades, maximum power point tracking will be essential to optimizing power output. One underserved topic of research is the effect of inductor current ripple on performance of Maximum Power Point Tracking (MPPT) algorithms. Many new topologies are focused on decreasing the ripple from PV source to increase efficiency and power output. However, not much has been done to show ripple degrading performance of MPPT algorithms. This study uses a boost converter topology to test the performance of constant duty cycle step Perturb and Observe (PO), Incremental Conductance IC, and Constant Voltage (CV) PID over a range of inductor current ripple factor. Inductor current ripple is controlled solely by changing inductance. This study concluded that all three algorithms were quite robust and affected very little over an inductor current ripple factor range of 20% to 40%. One novel finding was increased duty cycle oscillation when the MPPT update and sample speed was faster than the boost converter response.

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