Poor employee performance is one of employer’s most common challenges. The study aims to explore the effectiveness of a Performance Enhancement Programme (PEP) used within an electricity supply company and identifying the contributing factors for managers and supervisors not utilizing the programme. The research method consists of two parts, a literary review and an empirical study. The empirical study was done by means of a survey conducted on a sample of 210 Eskom supervisors and managers of the North Western Region of Eskom. The measuring instrument consisted of a structured questionnaire, developed by the researcher. The results revealed that supervisors and managers are using PEP and that they see it as a good tool to manage poor performance. Respondents indicated very clearly that they need training to be able to address poor performance. The findings concerning the effectiveness of the PEP were inconclusive. The small sample size was a limitation to the study. The questionnaire proved to be lacking in determining the effectiveness of the Performance Enhancement Programme. The sample only included supervisors and managers in the North Western Region of Eskom. Further research needs to be conducted with a larger sample including employees on all levels. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2012.

Saudi Arabia is progressing with Vision 2030, an ambitious blueprint for economic variation, global connection, and improved quality of life. The Hajj pilgrimage is addressed by the Doyof Al Rahman Program (DARP), one of the vision's programs aiming to enhance the Hajj experience. The Hajj pilgrimage is one of the world's largest annual massive gatherings and it has already received increased attention from researchers combining elements of pilgrimage and tourism. This dissertation aims to explore Hajj service quality and pilgrims' satisfaction. To attain this objective, a narrative and systematic literature review was conducted to develop a framework with standardized dimensions for Hajj with the consideration of Vision's 2030 PEP program objectives. The conducted literature review considered 157 sources following the PRISMA review protocol in the analysis. A Delphi study distributed among fifteen experts processed the literature review findings to confirm the research instrument dimensions' priority, applicability, and clarity. The proposed dimensions were Hospitality, Guidance, Transportation, Hajj Facilities, Safety and security, and Healthcare. Those dimensions are dedicated to exploring Hajj Service Quality (HSQ) performance and its impact on the Hajj's overall satisfaction and willingness to extend visits to heritage sites. The dissertation connected a confirmatory mixed research method in the Delphi study and data collection phases. The research survey contained 83 items distributed through the Qualtrics platform and yielded 149 valid responses from 17 U.S. states. After the data preparation, a Partial Least Square Structural Equation Modeling (PLS-SEM) analytical approach was deployed. First, the measurement model inspected the reliability and validity of the model constructs. Second is the structural model that tested the study hypothesis with path analysis a regression-based technique. The findings showed a significant impact from all the applied HSQ dimensions on Hajj overall satisfaction and a significant impact from Hajj facilities on the willingness to extend the visit to heritage sites.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The first study characterized the expression of MAS receptor and key enzymes for Ang-(1-7) production, such as, ACE2, NEP and PEP during follicular development. Furthermore, the regulation of local Ang1-7 system was evaluated after the intrafollicular injection of fulvestrant (an estradiolreceptor inhibitor) in the dominant follicle. Cows were ovariectomized when the size between the largest (F1) and the second largest follicle (F2) was not statistically different (Day 2), slightly different (Day 3), or markedly different (Day 4). The mRNA abundance of genes encoding MAS receptor, ACE2, NEP and PEP was evaluated in the follicular cells from F1 and F2. The mRNA expression of MAS receptor was upregulated in the granulosa cells of F2 after the establishment of follicular deviation (Day 4), while PEP mRNA increased during (Day 3) and after (Day 4) the deviation process. However, the mRNA expression of ACE2 was upregulated in the granulosa cells of F1 during and after the deviation process. The mRNA expression of NEP was not regulated in F1 and F2. The MAS receptor was immunolocated in the granulosa and theca cells of F1 and F2 during follicular deviation. Moreover, MAS receptor gene expression increased when the F1 was treated with the estrogen receptor-antagonist in vivo. In conclusion, the expression profile of MAS receptor, ACE2, NEP and PEP in dominant and subordinate follicles indicated that Ang-(1-7) play a role in the regulation of the follicular dominance in cattle. A second study was performed to investigate the expression of genes that control homologous recombination (HR; 53BP1, ATM, RAD50, RAD51, RAD52, BRCA1, BRCA2 and NBS1), and non-homologous end-joining (NHEJ; KU70, KU80 and DNAPK), DNArepair pathways in bovine embryos with high, intermediate or low developmental competence. We also evaluated whether bovine embryos can respond to DNA double-stranded breaks (DSBs) induced by ultraviolet (UV) irradiation by regulating the expression of genes involved in the HR and NHEJ repair pathways. Embryos with high, intermediate or low developmental competence were selected based on the cleavage time after in vitro fertilization and were removed from in vitro culture before (36 h), during (72 h) and after (96 h) the expected period of embryonic genome activation (EGA). All studied genes were expressed before, during and after the EGA period regardless the developmental competence of the embryos. Higher mRNA expression of 53BP1 and RAD52 was found before EGA in embryos with low developmental competence. Expression of 53BP1, RAD51 and KU70 was downregulated at 72 h and upregulated at 168 h post-fertilization in bovine embryos with DSBs induced by UV irradiation. In conclusion, important genes controlling HR and NHEJ repair pathways are expressed in bovine embryos before, during or after EGA. Lower developmental competence seems to be associated with a higher mRNA expression of 53BP1 and RAD52. Bovine embryos can response to UV-induced DSBs after the EGA but HR and NHEJ repair pathways seem to be particularly regulated at the blastocyst stage. / O primeiro estudo caracterizou a expressão do receptor MAS e de enzimas responsáveis pela produção de Ang-(1-7), tais como, enzima conversora de angiotensina 2 (ACE2), endopeptidase neutra (NEP) e prolil endopeptidase (PEP) durante o desenvolvimento folicular. Além disso, a regulação local do sistema Ang-(1-7) foi avaliada após a injeção intrafolicular de fulvestrant (inibidor do receptor de estradiol) no folículo dominante. As vacas foram ovariectomizadas quando o tamanho entre o maior (F1) e o segundo maior folículo (F2) não era estatisticamente diferente (D2), ligeiramente (D3) ou marcadamente diferente (D4). A expressão de RNAm do receptor MAS, ACE2, NEP e PEP foi avaliada nas células foliculares do F1 e F2. O receptor MAS foi mais expresso nas células da granulosa do F2 após o estabelecimento da divergência folicular (D4), enquanto a expressão de PEP aumentou durante (D3) e após (D4) o processo de divergência. Entretanto, a expressão de ACE2 foi maior nas células da granulosa do F1 durante e após a divergência. A expressão de PEP não foi regulada no F1 e F2. O receptor MAS foi imunolocalizado nas células da teca e granulosa do F1 e F2 durante a divergência folicular. A expressão de RNAm do receptor MAS aumentou quando o F1 foi tratado com fulvestrant in vivo. Em conclusão, o perfil de expressão do receptor MAS, ACE2, NEP e PEP nos folículos dominante e subordinado indicam que a Ang-(1-7) apresenta uma função na regulação da dominância folicular em bovinos. Em um segundo estudo investigamos a expressão de genes que controlam o reparo do DNA através das vias de recombinação homóloga (HR; 53BP1, ATM, RAD50, RAD51, RAD52, BRCA1, BRCA2, NBS1) e união terminal não homóloga (NHEJ; KU70, KU80, DNAPK) em embriões bovinos com alta, média ou baixa competência de desenvolvimento. Foi também avaliado se embriões bovinos podem responder a quebra na fita dupla de DNA (DSBs), induzida por irradiação UV, através da regulação de genes envolvidos nas vias de reparo HR e NHEJ. Embriões com alta, média ou baixa competência de desenvolvimento foram selecionados pelo tempo de clivagem após a fertilização in vitro e foram removidos do cultivo antes (36 h), durante (72 h) ou após (96 h) o momento esperado para a ativação do genoma embrionário (AGE). Todos os genes foram expressos antes, durante e após a AGE independentemente da competência de desenvolvimento dos embriões. A expressão de 53BP1 e RAD52 foi maior antes da AGE em embriões com baixa competência de desenvolvimento. A expressão de 53BP1, RAD51 e KU70 foi mais baixa as 72 h e maior as 168 h pós fertilização em embriões com DSBs induzida por irradiação UV. Em conclusão, genes importantes para o controle das vias de reparo HR e NHEJ são expressos em embriões bovinos independentemente do tempo de cultivo ou da competência de desenvolvimento. A menor competência de desenvolvimento embrionário parece estar associada com maior expressão de 53BP1 e RAD52. Os embriões bovinos respondem a DSBs após a AGE mas as vias HR e NHEJ são reguladas principalmente no estágio de blastocisto.

Bakgrund Patienter som genomgår thoraxkirurgi har postoperativt en försämrad lungfunktion och löper större risk för att utveckla lungkomplikationer. Positivt exspiratoriskt tryck (PEP) är en metod som används för att motverka postoperativa lungkomplikationer där PEP-flaska och PEP-mask är vanliga hjälpmedel. Forcerad oscillerande teknik (FOT) är en skonsam metod för utvärdering av lungornas resistans och reaktans. Resistansen beror på friktion i luftvägarna samt deras elastiska egenskap och reaktansen är luftvägarnas egenskap att lagra energi för passiv utandning. Kunskap om hur luftvägarnas resistans och reaktans påverkas av andningsgymnastik saknas.   Syfte Syftet med denna studie är att undersöka hur konventionell andningsgymnastik påverkar luftvägarnas resistans och reaktans postoperativt hos patienter som genomgått öppen hjärtkirurgi då dessa mäts med oscillerande luftvågor.   Metod Patienter (n=19) som genomgått öppen hjärtkirurgi inkluderades i studien. Luftvägarnas resistans och reaktans utvärderades med FOT vid tre mättillfällen, först preoperativt sedan två dagar efter operation både före och efter andningsgymnastik. Andningsgymnastik utfördes med både PEP-flaska och PEP-mask, randomisering avgjorde vilket hjälpmedel som användes först.    Resultat Luftvägarnas resistans och reaktans försämrades 2 dagar efter operation för samtliga patienter. Efter utförd andningsgymnastik med både PEP-flaska och PEP-mask sågs en höjning av luftvägsresistans.   Slutsats Resultaten i denna studie tyder på att PEP-andning med PEP-flaska och PEP-mask påverkar luftvägarnas resistans men inte reaktans. Mer forskning krävs för att bekräfta eller motbevisa detta resultat.

Die vorliegende Arbeit ist Teil eines Stoffwechselmodellierungsprojektes von Escherichia coli K-12. Grundlage dieses Projektes ist ein neuartiges Konzept, welches das zelluläre System in funktionelle Einheiten einteilt. Eine wichtige Einheit stellt die Nahrungssuche dar, die alle Gene und Genprodukte, die im Zusammenhang mit dem Kohlenstoff-Katabolismus, der Glykolyse/Glukoneogenese und der Energiegewinnung stehen, beinhaltet. Die Definition von funktionellen Einheiten erfolgt nach drei Kriterien: Gemeinsames physiologische Ziel Gemeinsame genetische Einheit Gemeinsames Signaltransduktionsnetzwerk. Eine besondere Stellung innerhalb der funktionellen Einheit Nahrungssuche nimmt das PEP zu Pyruvat Verhältnis ein. Es verbindet die Glykolyse/Glukoneogenese mit den PTSs und dem TCA-Zyklus. Die Zelle hat die Möglichkeit über dieses Verhältnis die katabolischen Aktivitäten zu messen und diese Informationen in einen intrazellulären Spiegel des Alarmons cAMP umzusetzen, durch den die Zelle der katabolischen Situation angemessen reagieren kann. Das Verhältnis von PEP zu Pyruvat wurde im Zuge dieser Arbeit weitergehend untersucht: 1) Das Verhältnis sollte von außen durch die Zugabe von Pyruvat verändert und die Reaktion auf die Phosphotransferasesysteme anhand des Phosphorylierungszustandes der PTS-Komponente EIIACrr verfolgt werden. 2) Das Verhältnis von PEP zu Pyruvat wird direkt durch die Enzyme EI, PEP-Synthase und Pyruvat-Kinase A und F eingestellt. Die Glykolyse/Glukoneogenese Enzyme wurden anhand ihrer Genexpression genauer Untersucht.

Die Transkription der Chloroplasten ist erstaunlich komplex. Ihr relativ kleines Genom kodiert für Komponenten der Photosynthese und der eigenen Genexpressionsmaschine. Es wird mindestens durch zwei RNA Polymerasen transkribiert. Neben der plastidär kodierten RNA Polymerase (PEP), existiert mindestens eine weitere kernkodierte RNA Polymerase (NEP). Die PEP spielt eine wichtige Rolle bei der Expression der Photosynthesegene und ist essentiell für die Biogenese der Chloroplasten und schließlich für das Überleben der Pflanzen. In der vorliegenden Arbeit wird erstmals die spezifische Interaktion der PEP mit ihren Transkriptionseinheiten unter verschiedenen Lichtbedingungen in vivo auf plastomweiter Ebene gezeigt. Darunter befinden sich hauptsächlich DNA Fragmente, die Photosynthesegene repräsentieren. Außerdem zeigt die PEP eine eindeutige Präferenz zu den rRNA Genen und einigen tRNA Genen. Eine Reduktion dieser Assoziation der PEP in Dunkelperioden lässt einen lichtabhängigen Prozess bei der PEP-DNA Assoziation vermuten. Außerdem wurde die PEP Aktivität an den bestimmten DNA Regionen in vivo ermittelt durch die Analyse naszierender Transkripte. Ein Großteil der plastidären RNA Spezies kopräzipitiert mit der PEP, aber sie scheint präferentiell mit tRNAs zu interagieren. Die Analyse der Verteilung der PEP bewies erstmals, dass sie hauptsächlich mit den Membranen assoziiert. Dort befindet sich auch das transkriptionsaktive Chromosom (TAC). Im TAC wurden vor kurzem neben der PEP auch Mitglieder von RNA Prozessierungsfaktoren identifiziert, was auf eine mögliche Kopplung von Transkription und posttranskriptionellen Prozessen hindeutet. Für einen Einblick in dieses Interaktionsnetzwerk wurden Transkriptanalysen des TACs ausgeführt. Mit wenigen Ausnahmen assoziieren alle plastidären RNA Spezies mit dem TAC. Einige RNAs liegen bereits prozessiert vor, was eine Verbindung zwischen Transkription und posttranskriptionellen Prozessen noch im TAC vermuten lässt. / Chloroplast transcription is astonishingly complex. The relative small genome of plastids, which codes for components of the photosynthetic machinery as well as for components of their own gene expression machinery, is transcribed by at least two different RNA polymerases. Beside the plastid-encoded plastid RNA polymerase (PEP) a nuclear-encoded plastid RNA polymerase (NEP) exists as well. PEP plays a major role in the expression of photosynthesis genes and is essential for chloroplast biogenesis and thus for plant survival. This work shows the specific in vivo interaction between PEP and its transcription units under different light conditions on a plastome-wide scale. Among them are DNA fragments that represent photosynthetic genes. In addition, PEP shows clear preferences to rRNA and tRNA genes. Furthermore, the association of PEP with photosynthesis-related genes was reduced during the dark period, indicating that PEP-DNA association is a light-dependent process. To survey PEP activity in vivo on plastid DNA regions, the association to nascent transcripts was analyzed. The majority of plastid RNA species could be found in PEP precipitates, but PEP seems to interact more strongly with tRNAs. Analysis of the suborganellar distribution of PEP shows that PEP is preferably associated with chloroplastmembranes. The transcriptionally active chromosome (TAC) was also found to be membrane-attached. Beside PEP different RNA processing factors were identified within the TAC and related purifications, indicating a possible coupling of transcription and posttranscriptional processes. To gain more insights into this interaction network, transcripts of TAC were analyzed. It is shown that nearly all plastid RNA species with only a few exceptions are associated to the TAC and that at least selected transcripts are already processed. This indicates that there is a link between transcription and posttranscriptional processes already within the TAC.

Ces travaux de thèse concernent le développement d'une biopuce à membranes permettant de réincorporer de manière fonctionnelle une protéine transmembranaire de la famille des récepteurs couplés aux protéines G (RCPG), CXCR4, dans une bicouche lipidique attachée et espacée sur un substrat d'or par pilotis peptidiques (pep-tBLM), sous un format miniaturisé et parallélisé. Le peptide pilotis utilisé, P19-4H, possède une cystéine en position N-terminale pour son greffage covalent sur la surface d'or et quatre résidus Histidine en position C-terminale pour l'attachement par chélation, en présence de Nickel, de protéoliposomes réintégrant CXCR4. La synthèse de cette protéine s'effectue par expression acellulaire sous forme de protéoliposomes, dans une composition lipidique adaptée et en présence d'un lipide chélatant, le DOGS-NTA, à 2% de la quantité molaire totale des lipides. Le peptide AH, un peptide fusogène, est utilisé dans une dernière étape pour fusionner les protéoliposomes attachés. La caractérisation approfondie des protéoliposomes et l'optimisation des conditions expérimentales ont permis d'aboutir à l'attachement robuste des protéoliposomes avec une densité lipidique suffisante pour leur fusion par le peptide AH et la formation d'une pep-tBLM réintégrant CXCR4. Des études de recouvrement de fluorescence après photoblanchiment (FRAP) ont montré que la pep-tBLM réinsérant CXCR4 était fluide, homogène et continue, avec un coefficient de diffusion de 2.10-7 cm2/s. Des études d'interaction entre CXCR4 et un ligand antagoniste, le T22, ont révélé que la protéine s'insère dans la pep-tBLM de manière fonctionnelle et orientée. Le processus de formation de la pep-tBLM a été miniaturisé par microstructuration du support consistant à recouvrir la surface d'or de polystyrène puis à former des micropuits exposant la surface d'or en leur fond. Le peptide P19-4H a été déposé de manière contrôlée dans les micropuits à l'aide d'un robot de dépôt pour former des plots de pep-tBLM intégrant CXCR4. La fonctionnalité de CXCR4 réinsérée dans ces plots de membranes a été attestée par des études d'interaction avec son ligand T22. L'ensemble des étapes de formation, d'optimisation et de miniaturisation des pep-tBLM a été suivi, visualisé et caractérisé en temps réel et sans marquage par la technique d'imagerie par résonance plasmonique de surface (SPRi). La technologie « TransMembraChip » développée au cours de cette thèse représente une méthode de choix pour la réincorporation et l'étude fonctionnelle de protéines transmembranaires dans une composition lipidique adaptée. Les protéines transmembranaires, en particulier les RCPG, représentent des cibles thérapeutiques intéressantes. Ainsi, dans le cadre de la recherche de candidats médicaments pour le traitement de pathologies impliquant des protéines transmembranaires, cette nouvelle génération de biopuce à membranes constitue un outil prometteur adapté au criblage de ligands agonistes ou antagonistes de ces protéines / This thesis presents the development of a membrane biochip allowing to functionally reincorporate a transmembrane protein of the G-protein coupled receptor (GPCR) family, CXCR4, in a peptide-tethered bilayer lipid membrane (pep-tBLM), in a miniaturized and parallelized format. The peptide tether used, P19-4H, possesses a cysteine in its N-terminal extremity for covalent grafting onto the gold surface and four Histidine residues in its C-terminal extremity for attachment of proteoliposomes integrating CXCR4 by metal-chelate interaction in the presence of nickel. The synthesis of CXCR4 was carried out by cell-free expression in the form of proteoliposomes, in a suitable lipid composition and in the presence of a chelating lipid, DOGS-NTA, at 2% molar ratio. The AH peptide, a fusogenic peptide, was employed in a last step to fuse the attached proteoliposomes. The thorough characterization of proteoliposomes and the optimization of experimental conditions led to the robust attachment of proteoliposomes with sufficient lipid density to perform their fusion by the AH peptide and the formation of a pep-tBLM integrating CXCR4. Fluorescence recovery after photobleaching (FRAP) studies have shown that the pep-tBLM reinserting CXCR4 was fluid, homogeneous and continuous, with a diffusion coefficient of 2 x 10-7 cm2/s. Ligand binding studies between CXCR4 and T22, an antagonist, revealed that the protein was functional and well-oriented in the peptBLM. The formation process of the pep-tBLM was miniaturized by support microstructuration, consisting in covering the gold surface with polystyrene and then, forming microwells exposing the gold surface at their bottom. The P19-4H peptide was spotted in a controlled manner into the microwells to form microspots of pep-tBLM incorporating CXCR4. The functionality of CXCR4 reinserted into these membrane microspots was confirmed by T22 ligand binding studies. All the steps of formation, optimization and miniaturization of the pep-tBLM were monitored, visualized and characterized by surface plasmon resonance imaging (SPRi), a real time and label-free technique for the detection of interactions. The "TransMembraChip" technology developed in this work represents a method of choice for the reincorporation and functional study of transmembrane proteins in a suitable lipid composition. Transmembrane proteins, particularly GPCRs, form interesting therapeutic targets. Thus, in the context of pharmaceutical research of drug candidates for the treatment of pathologies involving transmembrane proteins, this new generation of membrane biochip is a promising tool for screening agonist or antagonist ligands of these proteins

Thesis (PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Plants exhibit a flexible array of morphological, physiological and biochemical adaptations during phosphorous limitation. Legumes are vulnerable to P deficiency, because it affects their ability to fix atmospheric nitrogen (N2). In particular, legumes from nutrient-poor ecosystems, such as the Fynbos in the Cape Floristic Region (CFR) evolved on P deficient soils and may therefore display unique adaptations to soil P stress. In general, very few studies on legumes have focussed on the belowground structures of nodules as a plant organ. Moreover, even less is known about the P stressed responses in nodules from legumes in nutrient-poor ecosystems. The aim of this research was to investigate the metabolic flexibility of organic acid and amino acid metabolism in the nodulated root system of the Fynbos legume Virgilia divaricata, during low P stress. Virgilia divaricata, which grows in the Cape Floristic Region, was used in this study to enhance our knowledge regarding the vital role that the cytosolic enzyme, phosphoenol pyruvate carboxylase (PEPC) plays in phosphoenol pyruvate (PEP) metabolism, in roots and nodules of this legume during phosphate stress. V. divaricata was grown under glasshouse conditions (20 - 25°C) in sterilized quartz sand for 2-3 months whilst being inoculated with the nitrogen fixation bacteria, Burkholderia phytofirmans, which was isolated from V. divaricata nodules grown in fynbos soil. Two phosphate treatments, 5 μM and 500 μM, were applied simulating low-phosphate and high phosphate conditions respectively using a modified Long Ashton Nutrient Solution to simulate a low nutrient ecosystem such as the Cape Floristic Region. Roots and nodules were then analysed for growth kinetics, nutrient acquisition and distribution, enzyme activity and genetic responses. It was shown that during phosphate deficiency, V. divaricata nodules experienced less Pi stress than roots, due to increased metabolic phosphate conservation reactions during organic acid synthesis via an increased PEPC activity. The increased PEPC activity resulted in an increase in downstream metabolic products such as organic acids, (malic acid and citric acid), and amino acids (glutamate, aspartate and asparagine). Although the biological nitrogen fixation (BNF) declined, the high efficiency of BNF may be underpinned by these altered phosphate conservation pathways and enhanced resource allocation during growth particularly under low phosphate (LP) conditions. Therefore, it can be concluded that the efficiency of the nodules via an increased allocation of resources and P acquiring mechanisms in V. divaricata may be the key to the plant’s ability to adapt to poor P environments and thus sustaining its reliance on BNF. From the data obtained as well as previous findings, it has been established that the phosphate conservation mechanisms in roots and nodules, involve the non-adenylate requiring PEPC-bypass route. 13C Nuclear magnetic resonance (NMR) gave us a better understanding regarding the incorporation rates of the PEPCderived C into malate, α-ketoglutarate and asparagine. It therefore is suggested that V. divaricata nodules may use their large PEPC-derived malate pool to prevent large declines in BNF under low phosphate conditions. The nodules of V. divaricata were able to offset an excessive drop in BNF, despite a decline in inorganic phophosphate (Pi) levels. It therefore appears that nodules have evolved to acquire different mechanisms than roots to adapt to phosphate deficiency in order to maintain their function. This was achieved via increased regulation of nodule PEPC and its downstream products. This implies that compared to roots under low P, nodules alter the metabolism of PEPC derived C, in order to maintain nodule respiration and amino acid synthesis. This trait could be observed in the synthesis of larger 13C malate pools of nodules compared to roots, from PEPC, which was underpinned by their different regulation mechanisms of enzyme activity, of the same protein isoform. Since malate is a potent inhibitor of PEPC activity, roots appear to have invested in more PEPC protein compared to nodules. In contrast, nodules with lower PEPC protein, achieved greater enzyme activity than roots, possibly due to higher phosphorylation in order to reduce the malate effect. The subsequent metabolism of this PEPCderived malate, caused roots and nodules to synthesise asparagine via different pathways. These findings imply that roots and nodules under P stress, synthesise their major export amino acid, asparagine, via different routes. This research has generated new knowledge regarding the physiological impact of the organic and amino acid metabolism, derived from PEPC-C in the roots and nodules of legumes growing in nutrient poor ecosystems. It has demonstrated for the first time that the nodules of legume from a nutrient-poor ecosystem rely on improved resource allocation, Pi distribution, and PEPC-derived organic acids to maintain the efficient functioning of N assimilation under P stress. This may be a consequence of having evolved in a nutrient-poor ecosystem, so that nodule-bacteroid respiration and N metabolism can be maintained in P-poor soils such as the Fynbos. / AFRIKAANSE OPSOMMING: Tydens fosfaat stremming maak plante gebruik van buigsame kombinasies van morfologiese, fisiologiese en biochemiese aanpassings. Peulplante is sensitief vir fosfaat tekorte omdat dit die vermoë om atmosferiese stikstof te kan fikseer, grootliks beïnvloed. Peulplante vanuit ekosisteme met mineraal-arme gronde, soos Fynbos binne die Kaapse Blommeryk, het ontwikkel in grond met lae fosfaatvlakke en mag dus unieke aanpassings tot fosfaat tekorte toon. Oor die algemeen is daar baie min peulplant studies wat fokus op die ondergrondse strukture van wortelknoppies as ‘n plant orgaan. Nog minder inligting is beskikbaar oor wortelknoppies, van peulplante, vanuit mineraalarme ekosisteme, se reaksie teenoor ‘n fosfaat tekort. Die doel van hierdie navorsing was om die metaboliese buigsaamheid van organiese- en aminosuur metabolisme in die (nodulated) wortelknoppie-wortelstelsel van die Fynbos peulplant Virgilia divaricata, tydens fosfaat tekort te ondersoek. Virgilia divaricata wat voorkom in die Kaapse Blommeryk, was gebruik in hierdie studie om die huidige kennis te verbeter van die essensiële rol wat die sitisoliese ensiem, fosfo-enol piruvaat karboksilase (PEPC) in fosfo-enol piruvaat metabolisme tydens ‘n fosfaat tekort speel binne die wortels en wortelknoppies van hierdie peulplant. V. divaricata was gegroei onder glashuis toestande (20 - 25°C) in gesteriliseerde kwartssand vir 2-3 maande. Die plante was geïnokuleer met die stikstoffikserende bakterie, Burkholderia phytofirmans, wat geïsoleer is vanaf V. divaricata wortelknoppies wat in Fynbos grond gegroei is. Twee fosfaatbehandelings, 5μM and 500μM, was toegedien om lae en hoë fosfaat toestande, onderskeidelik, na te boots deur gebruik te maak van ‘n aangepasde Long Ashton voedingstofmengsel om ‘n ekosisteem, soos die Kaapse Blommeryk, met lae voedingstofvlakke na te boots. Die wortels en knoppies was geanaliseer ten opsigte van die groeikinetika, opname en verspreiding van voedingstowwe, ensiemaktiwiteit en genetiese aanpassings. Dis is bewys dat tydens fosfaat tekort V. divaricata wortelknoppies minder fosfaat stres ervaar as die wortels, as gevolg van die verhoogde metaboliese fosfaat bewaringsreaksies tydens organise suur sintese via die styging in PEPC aktiwiteit. Die styging in PEPC aktiwiteit lei tot ‘n verhoging in stroomaf metaboliese produkte soos organiese- (appel- en sitroënsuur) en aminosure (glutamaat, aspartaat en asparagien). Alhoewel biologiese stikstoffiksering verlaag het, kan die hoë doeltreffendheid daarvan ondersteun word deur díe aangepasde fosfaat bewarings weë asook verhoogde hulpbron toekenning tydens groei onder lae fosfaat omstandighede. Dit kan dus afgelei word dat die doeltreffendheid van die wortelknoppies via die verhoging in belegging van hulpbronne en fosfaat opname meganismes in V. divaricata moontlik die sleutel is tot die plant se vermoë om aan te pas tot omgewings met lae fosfaatvlakke en sodoende die afhanklikheid van biologiese stikstofbinding te kan onderhou. Data in hierdie as ook vorige studies, wys dat die fosfaat bewaringsmeganismes in wortels en wortelknoppies die PEPC-ompad roete, wat nie adenilaat benodig nie, gebruik. 13C NMR het meer lig gewerp aangaande die vaslegging van koolstof vanaf PEPC na malaat, α-ketoglutaraat en asparagien. Dit word voorgestel dat V. divaricata knoppies ‘n groot hoeveelheid malaat, afkomstig van PEPC-werking, gebruik om groot dalings in biologiese stikstofbinding tydens fosfaat tekort, te verhoed. Die wortelknoppies van V. divaricata kon ‘n oormatige verlaging in biologiese stikstofbinding voorkom ten spyte van die verlaging in fosfaatvlakke. Dit wil voorkom dat wortelknoppies ander meganismes as die wortels ontwikkel het om aan te pas tot fosfaat tekort en sodoende dus hul funksie behou. Dit word bereik deur ‘n verhoging in die regulering van PEPC en die stroomaf produkte in die wortelknoppies. Dit blyk dat wortelknoppies tydens fosfaat te kort, in vergelyking met wortels, die metabolisme van die koolstof vanaf PEPC verander om sodoende respirasie en aminosuursintese te onderhou. Dit wil voorkom dat hierdie meganismes verskil van die van wortel meganismes. Hierdie eienskap kan toegeskryf word aan die produksie van ‘n groter hoeveelheid van 13C malaat vanaf PEPC in die wortelknoppies teenoor die wortels, wat ondersteun word die verskillende reguleringsmeganismes van ensiemaktiwiteit van dieselfde proteïen isoform. Malaat is ‘n kragtige inhibeerder van PEPC-aktiwiteit, dus blyk dit dat die wortels belê in meer PEPC proteïene as die wortelknoppies. In teenstelling, toon die wortelknoppies met laer PEPC proteïene, ‘n hoër ensiem aktiwiteit as die wortels. Dit kan wees as gevolg van hoër fosforilasie om die effek van malaat te verlaag. Die metabolisme van die malaat vanaf PEPC het die sintese van asparagien in die wortels en wortelknoppies via verskillende roetes tot gevolg gehad. Dit impliseer dat tydens ‘n tekort aan fosfaat, wortels en wortelknoppies hul hoof uitvoer aminosuur, asparagien, deur verskillende roetes sintetiseer. Hierdie studie het nuwe kennis aangaande die fisiologiese impak van organiese- en aminosuur metabolisme met koolstof vanaf PEPC in die wortels en wortelknoppies van peulplante wat voorkom in ekosisteme met lae voedingstofvlakke, voortgebring. Vir die eerste keer is dit bewys dat die wortelknoppies vanaf peulplante wat voorkom in mineraal-arme ekosisteme, staatmaak op verbeterde hulpbron beleggings, fosfaat verspreiding en organiese sure vanaf PEPC om die doeltreffendheid van funksionele stikstofassimilasie tydens fosfaat tekort, te onderhou. Dit mag die gevolg wees van, om in ‘n voedingstof arme ekosisteem te ontwikkel sodat die wortelknoppiebakteroïed respirasie en stikstofmetabolisme onderhou kan word in fosfaat arme grond soos die Fynbos.

The Master's thesis analyses the macroeconomic aspects of the exchange rate policy of the administration of president Hugo Chávez Frías in Venezuela in 2003 - 2010. The author focuses first on the comparison of different exchange rate regimes and their compatibility with the commodity depended economies. A special attention is paid to the concept of Peg to Export Price regime (PEP), also called oil standard, of Jeffrey Frankel and its suitability for contemporary Venezuela. The goal of the thesis is to stress that even though the election of a correct exchange rate regime is of great importance for an exporting economy, the success can be achieved only when combining it with an appropriate monetary and fiscal policy. Without an adequate economic policy the regime alone can not provide stability and moderate high inflation.

<p>This master thesis is a result of the work carried out for Research Electronics at Siljansnäs. The company develops customized electronical systems. Because of the rapidly increasing interest in colour displays there has been a desire within the company to represent information from sensors and electrical systems in a more advanced way.</p><p>Due to the mentioned reason above we were given the assignment to solve how a colour display using the STN technique works. The technique is used by small displays, the size of QVGA. Our ambition of this diploma work is to develop a fully functionally test prototype to evaluate the LCD (Liquid Crystal Display) and the LCD controller. The most important results from this study is the documentation of how a LCD controller works and how the pixels are addressed. We succeded in showing all the pixels we were able to address at the right place on the LCD wich indicates that there is a compatibility between the LCD and the LCD controller . A replacement of the LCD is recommended because of the difficulties working with it. Precisely wich LCD it should be replaced with is not mentioned in this report because of the extent of the work. One of the aims was to evaluate the function of the LCD, not to find an alternative LCD.When studiyng the LPC2129 and MC68K it emerged that both suits well as controlling units for this application, but an implemention with LPC2129 involves greater diffculties because of the absence of external system bus. Our aim is that this work will function as a starting point to further development leading to a controlling unit in working order, and that it will be implemented in other products the company develops.</p> / <p>Föreliggande rapport behandlar vårt magisterarbete på 20 poäng. Arbetet är gjort åt Research</p><p>Electronics i Siljansnäs som utvecklar skräddarsydda elektroniksystem. På grund av den ökade efterfrågan av färgdisplayer från marknaden har det länge funnits ett behov av att presentera information från givare och mätinstrument på ett mer avancerat sätt.</p><p>Av ovan nämnda skäl fick vi i uppdrag att undersöka hur en färgdisplay av typen STN (Super Twist Nematic) fungerar. Det är oftast små displayer som använder den här tekniken. Målet från början var att utveckla en fungerande testprototyp för att testa grafikcontrollern och displayen. De viktigaste resultat som framkommit efter arbetet är en dokumentation på hur en grafikcontroller fungerar och hur adressering av pixlar sker. Vi har visat att det är möjligt att använda den givna grafikcontrollern tillsammans med den display som köpts in då alla pixlar som gick att adressera visats på önskad plats på skärmen. Det finns också en rekommendation av byte till en annan display som är enklare att arbeta med. Exakt vilken anges inte i rapporten eftersom det inte har ingått i arbetet att ta hitta en alternativ display utan att undersöka den befintliga. Studien av mikrocontrollern LPC2129 från Philips och processorn MC68K från Freescale visar att båda är bra för applikationen. LPC2129 blir svårare att arbeta med till följd av att det saknas extern systembuss. Våra förhoppningar är att examensarbetet ska bli en god grund för fortsatt arbete som leder till en färdig produkt, och att den används i övriga tillämpningar i företaget.</p>