Knowledge about the structure, conformation and dynamics of carbohydrates is important in our understanding of the way carbohydrates function in biological systems, for example in intermolecular signaling and recognition. This thesis is a summary of five papers studying these properties in carbohydrate-containing molecules with NMR spectroscopy and molecular dynamics simulations. In paper I, the ring-conformations of the six-membered rings of two carbaiduronic analogs were investigated. These carbasugars could potentially be used as hydrolytically stable mimics of iduronic acid in drugs. The study showed that the equilibrium is entirely shifted towards the 4C1 conformation. Paper II is an investigation of the conformational flexibility and dynamics of two (1→6)-linked disaccharides related to an oligosaccharide epitope expressed on malignant tumor cells. In paper III, the conformational space of the glycosidic linkage of an alfa-(1→2) linked mannose disaccharide present in N- and O-linked glycoproteins, was studied. A maximum entropy analysis using different priors as background information was used and four new Karplus equations for 3JC,C and 3JC,H coupling constants, related to the glycosidic linkage, were presented. Paper IV describes a structural elucidation of the exopolysaccharide (EPS) produced by Streptococcus thermophilus ST1, a major dairy starter used in yoghurt and cheese production. The EPS contains a hexasaccharide repeating unit of d-galactose and d-glucose residues, which is a new EPS structure of the S. thermophilus species. In paper V, the dynamics of three generations of glycodendrimers were investigated by NMR diffusion and 13C NMR relaxation studies. Three different correlations times were identified, one global correlation time describing the rotation of the dendrimer as a whole, one local correlation time describing the reorientation of the C-H vectors, and one correlation time describing the pulsation of a dendrimer branch.

Upland peatlands provide vital ecosystem services, especially carbon storage and biodiversity. However, large areas of peatland are heavily degraded in the UK. When peat becomes exposed the potential for it to actively sequester carbon is greatly reduced and carbon stores are rapidly lost through erosion. Peatland restoration is a tool that addresses the government public service agreement targets for biodiversity, and soil and water protection in uplands. Blanket bogs are a UK Biodiversity Action Plan priority habitat. Many areas fall under designations for sites of protection under the EU habitats directive which is aimed at bringing the areas into ‘favourable condition’.The Moors for the Future Partnership is restoring large areas of badly eroded peat in the Peak District National Park to stabilise the surface and re-establish ecosystem functions. Monitoring is of pivotal importance to judge the success of the restoration work. This project assesses the suitability of high resolution remote sensing as an alternative monitoring tool to traditional field based plot surveys which are both time consuming and expensive. Remote sensing has been seen as a potential tool for mapping and monitoring peatlands, but to date the application of high spatial and spectral resolution remote sensing to monitoring peatland restoration has not been fully investigated. A floristic restoration trajectory has been established using a statistical classification (TWINSPAN) of vegetation cover data combined with expert knowledge of previous restoration, and autecology of the moorland species. Hyperspectral classification techniques were applied, including: Spectral Angle Mapping (SAM); Support Vector Machines (SVM); and maximum likelihood classification using both Minimum Noise Fraction (MNF), and narrow band vegetation indices. A successful classification of the restoration succession has been achieved. A predictive model for vegetation cover of plant functional types has been produced using a Partial Least Squares Regression and applied to the whole restoration site at the landscape-scale. RMSEs of between 10 and 16% indicate that the models can be used as a useful operational tool. A spectral library of key moorland species and their phenological response has been established using field spectroscopy in parallel to the image analysis. This has enabled the suggestion that the species are most separable from one another in July and it is recommended that this is the optimal month for remote sensing monitoring. This has facilitated the development of a set of recommendations for the most appropriate vegetation indices to use throughout the year depending species to be differentiated. High spatial and spectral resolution remote sensing data is needed to successfully characterise the vegetation response to restoration management in the upland peatland environment.

Master of Science / Department of Physics / Kristan L. Corwin / We investigate the nonlinear spectroscopy of acetylene in the near infrared region inside a photonic band gap fiber. The near infrared region of the optical spectrum is an area of intensive research due to its relevance to telecommunication and optical metrology. Acetylene provides a large number of reference transitions coincident with the international telecommunication band. Acetylene contains about 50 strong lines between 1510 nm and 1540 nm in the ν1+ν3 ro-vibrational combination band. We have observed the Doppler-free saturated spectrum of several of these lines. The light from a tunable diode laser at ~1531 nm, resonant with the P(11) transition, is amplified by an erbium doped fiber amplifier and split into a strong pump beam and weak probe beam which counter-propagate inside the gas-filled fiber. The measured Doppler linewidth of the P(11) line at room temperature is about 467 MHz wide. The sub-Doppler profile over a pressure range of 200-1600 mT appears as a narrow absorption feature about 20-40 MHz wide, even at the low pump power of ~10 mW. It is found that for a fiber with an 80 cm length, 20 core size, pumped with 29 mw, the optimum pressure is ~530mT. But the optimum pressure condition will further decrease when the fiber length increases.

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