Thesis (Ph. D.) in Oceanography--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 112-126).

Thesis--University of Michigan. / Includes bibliographical references.

Thesis (D.M.A.)--University of Missouri-Kansas City, 1975. / Publisher from label on t.p. "Complete works of Ray Green"-p. 123-169. Includes bibliographical references (p. 170-173).

Bakgrund: Dagens globalisering har möjliggjort en ökad handel mellan länder vilket har inneburit en ökad konsumtion och i sin tur en större negativ miljöpåverkan. Denna miljöpåverkan sker på grund av att produkterna som anskaffas leder till föroreningar genom avlägsna producenter och långa transportsträckor samt genom en icke-miljövänlig produktion. Att se över sina försörjningsstrategier blir alltså allt viktigare och Green sourcing bör övervägas framför traditionella sourcing strategier. Konceptet är relativt nytt och befinner sig fortfarande i utvecklingsfasen där fullständig forskning om Green sourcing saknas. Genom den begränsade forskning som finns inom området kan ett forskningsgap utskiljas då Green sourcing ännu inte utforskats inom offentligheten. Kommunerna har ett ansvar att tillfredsställa det samhälleliga behovet och upprätthålla ordningen. Detta ska de göra och samtidigt ta hänsyn till Lagen om offentlig upphandling och upphandlingsprocess. Dessa två faktorer påverkar kommunernas arbete med Green sourcing då regelverken sätter ramar och begränsningarna för hur arbetet ska gå till. Problemformulering: Hur omsätter offentlig verksamhet Green sourcing i praktiken med avseende på regelverken de måste förhålla sig till? Syfte: Syftet med detta ämnesfördjupande arbete är att identifiera goda exempel på hur kommunerna arbetar med att omsätta Green sourcing i praktiken samtidigt som de förhåller sig till Lagen om offentlig upphandlings regelverk och upphandlingsprocess. Metod: En kvalitativ undersökningsdesign har använts vid denna studie där semistrukturerade telefonintervjuer har genomförts med 5 kommuner. De deltagande kommunerna är Helsingborg, Malmö, Växjö, Älmhult och Örebro kommun. Slutsats: Resultatet visar att det finns en plattform för att arbeta med Green sourcing i offentlig verksamhet med avseende på regelverken de måste förhålla sig till. Samtliga kommuner arbetar med miljöfrågor men de har kommit olika långt för hur de går tillväga för att nå sina hållbarhetsmål. Studien visar att kommunerna genomför flera av aktiviteterna som Green sourcing bygger på, även om de inte arbetar utifrån konceptet som helhet. Goda exempel på hur de omsätter Green sourcing är genom att inkludera miljökrav i sina upphandlingar som ställer krav på leverantörens produktion, produkter och transportslag. De utför själva transportplaneringar i form av samordnade varudistributioner och ruttplaneringar för att minska miljöpåverkan. För att handskas med LOUs bestämmelser genomför kommunerna uppdelningar av upphandlingarna, ställer krav på att leverantören ska ha en verkstad i nära anslutning till kommunen och att produkterna uppfyller samma grunder som en önskad certifiering.

Astaxanthin (3,3'-dihydroxy-β-carotene-4,4'-dione) is a ketocarotenoid that is beneficial for human health due to its ability of boosting immune function and preventing tumor formation. The biosynthesis of astaxanthin is, however, limited only to a few organisms. The burgeoning demand for natural astaxanthin has attracted much recent interest in extending the carotenoid pathway of higher plants to astaxanthin by expressing a microbial β-carotene ketolase (BKT). One major challenge of engineering an astaxanthin pathway in plants is the low astaxanthin content achieved. Five green microalgae including Chlamydomonas reinhardtii, Chlorococcum sp., Neochloris wimmeri, Protosiphon botryoides and Scotiellopsis oocystiformis were selected with enhanced function for astaxanthin biosynthesis. The products of the BKT cDNAs from the algae are similar in sequence to the BKT from Haematococcus pluvialis (ca 70% amino acid identity). Based on an Escherichia coli system, the BKT enzymes were shown to exhibit various efficacies in converting zeaxanthin into astaxanthin with Chlamydomonas BKT exhibiting the highest conversion rate (ca 85%). To investigate if the function-enhanced Chlamdomonas BKT (CRBKT) has advantages over other algal BKTs in triggering astaxanthin biosynthesis in higher plants, the CrBKT, together with the BKTs from Chlorella zofingiensis (CzBKT) and H. pluvialis (HpBKT3) was expressed in Arabidopsis thaliana. Transgenic Arabidopsis expressing the CrBKT developed orange leaves which accumulated astaxanthin up to 2 mg g-1 dry weight. In contrast, the expression of CzBKT resulted in much lower content of astaxanthin (0.24 mg g-1 dry weight), whereas HpBKT3 was unable to mediate synthesis of astaxanthin in Arabidopsis. Similarly, overexpression of CrBKT in tobacco also resulted in the massive accumulation of astaxanthin in leaves (1.60 mg g-1 DW). Taken all together, it can be concluded that ketolating zeaxanthin efficiently is essential for high production of astaxanthin in transgenic plants. Tomato is an important food crop with high amounts of carotenoids in its fruit. To investigate if tomato fruit can serve as a bio-factory for astaxanthin production, the CrBKT was overexpressed in three genotypes of tomato. All transgenic tomato plants developed brown red leaves that accumulated canthaxanthin rather than astaxanthin as a major carotenoid, resulting from the poor catalytic activity of the endogenous BHY1 toward canthaxanthin. To overcome this problem, CrBKT and HpBHY, the best pair of genes catalyzing the formation of astaxanthin in β- carotene-producing E. coli, were coexpressed in tomato. Canthaxanthin was efficiently converted to astaxanthin, resulting in a massive accumulation of astaxanthin in leaf (3.12 mg g-1) and fruit (16.1 mg g-1) with enhanced total carotenoid capacities of 1.7-fold in leaf and 16.6-fold in fruit. Moreover, the over-production of astaxanthin in fruit enhanced its antioxidant capacity 3-5-fold and vitamin C 2-fold, although it did not affect growth and development. In summary, the Chlamydomonas BKT is proven to be superior to other sources of BKT/CrtW enzymes in triggering astaxanthin biosynthesis in plants. By coexpressing a pair of well-cooperating BKT and BHY genes, the transgenic B-type tomato could accumulate commercially attractive amounts of the high-value astaxanthin in its fruit. This study highlights the potential of higher plants to be engineered as cell factories for producing the high-value astaxanthin. / published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

abstract / Geography / Doctoral / Doctor of Philosophy

Urbanization replaces once permeable surfaces with relatively impervious ones, thereby degrading the natural hydrologic cycle. Impervious surfaces intensify stormwater runoff in terms of overall mass and temporal response, especially under torrential rainfalls. Since such runoff could become massive in volume and concentrated in time, they place significant stress on the urban drainage system and increase the risks of combined sewage overflow and flooding, which could introduce a range of deleterious consequences to cities and surrounding natural habitats. In sustainable urban stormwater management like the Low Impact Development, green roof presents an on-site source-reduction measure that mimics the pre-development hydrologic functions of storing and gradually releasing precipitation. Green roof can retain and detain stormwater as well as delay and suppress peak discharge. However, green roof stormwater studies have largely been conducted in non-tropical regions of the world. Since green roof’s quantitative hydrologic performance can be much influenced by local meteorological conditions, the degree to which such findings can be generalized to other climates, such as Hong Kong’s humid subtropical regime, calls for investigation. Moreover, substrate depth has long been regarded as an influential factor in green roof stormwater retention, but two recent studies have provided contradictory results. The objectives of this study are: 1) To evaluate green roof stormwater mitigation performance and potentials in Hong Kong for the first time; 2) To investigate systematically the effect of substrate depth on quantitative hydrologic performance; 3) To identify factors that affect green roof performance; 4) To develop a holistic conceptualization of the various system water storage spaces within a green roof system, for a better understanding of their role in stormwater mitigation. Using small-scale (1.1 m2) raised green roof plots placed on an actual urban rooftop, the effect of 40 mm soil, 40 mm soil + 40 mm rockwool, 80 mm soil, and 80 mm soil + 40 mm rockwool on stormwater mitigation performance relative to control were analyzed. Three core performance indicators (percent retention, peak delay, and peak reduction) were employed to evaluate green roof performance. The results suggest that, while the retention performance of the studied green roofs under Hong Kong’s heavy rainfall regime seems to be less effective, remarkable peak reduction and peak delay were observed even when the green roof system has reached full moisture-storage capacity. Such findings are in line with the proposed Green-roof System Capacity model that green roof serves as an effective buffer that regulates water flow through the system. No statistical significance was found between substrate-depth treatments, despite the higher performance across all three indicators for treatment 80. However, satisfactory peak performance of the 40-mm thin substrate suggests that green roof can be applied even on existing buildings that have limited loading capacity. Pertinent meteorological factors were identified. All in all, extensive green roof remains as an effective and promising alternative mitigation strategy to urban stormwater management in Hong Kong with potential application to other tropical areas. / Li Ka Shing Prize, The Best MPhil Thesis in the Faculties of Architecture, Arts, Business & Economics, Education, Law and Social Sciences (University of Hong Kong), 2012-2013. / published_or_final_version / Geography / Master / Master of Philosophy

This paper investigates the use of conservatories within South African climatic landscape. It discusses several conservatories built in South Africa, their design and function. Conservatories are an enclosed ‘intermediate area’ used as a design measure to create a passive solar environment for a climate responsive measure. The design and use of climate responsive technology and materials in buildings reduces the need for space air-conditioning. Thus, then enhances efforts towards designing and operating energy efficient buildings. An attempt should be made to take advantage of the natural phenomena surrounding the building, instead of fighting the influence of nature with expensive and often environmentally destructive heating, cooling, and lighting equipment and the energy they consumes. The importance of this paper is to give to a literature review on conservatories built in South Africa. It highlights the potential of using conservatories within South African climatic conditions, and provides a structural observation on the integrity of such a system. The paper looks at three conservatories constructed in the country, their application and the principal of the greenhouse effects within conservatories.

published_or_final_version / Botany / Master / Master of Philosophy

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