This dissertation consists of six separate papers dealing with the valuation of financial guarantees and risky debt contract. Each of these papers is independent and distinct. The main theme is the valuation of securities by contingent claims analysis (CCA). Paper 1: Valuation of Financial Guarantees – A Presentation and a Critique.One purpose of this paper is to derive a pricing formula for a deposit guarantee, when the assets of the bank exhibit downward jumps due to extraordinary loan defaults. In this respect, we use the framework of Merton (1976), where a stock option is priced under the assumption of a jump-diffusion process for the underlying stock. Paper 2: Valuation of Deposit Insurance – An Alternative Approach.This paper extends paper 1 in the respect that the guarantor, in this case a deposit insurance agency, will nullify the guarantee contract and liquidate the bank when it gets insolvent. The liquidation is assumed to involve some costs like legal and realization costs. In fact, since the guarantee contract will never get in-the-money, the guarantee will receive value only from these liquidation costs. Paper 3: Financial Guarantees and Asymmetric Information.In this paper, we make the assumption that the guarantor cannot observe the solvency process, unless it carries out audits. This is different from the normal perfect information assumption for this kind of analysis. Since audits are often costly, and this burdens the guarantee value, the guarantor will search for an audit strategy, which minimizes the guarantee value. Paper 4: Valuation of Barrier Contracts – A Simplified Approach.Many types of financial contracts can be classified as "barrier contracts". This description comes from their feature of allowing either contractual part to take some kind of action during the lifetime of the contract contingent on some pre-specified event. In this sense, the deposit insurance contract in analysed in paper 2 can be regarded as a barrier contract. The previous valuation models of barrier contracts are often considerably advanced and have tended to obscure the underlying economics. It is the path-dependence and stopping-time features that primarily make the derivation of these pricing formulas complicated. Our model simplifies this procedure by deriving the important "first passage time" distribution from a binomial model instead of using the reflection principle. Paper 5: Valuation of Risky Debt in the Presence of Jumps, Safety Barriers and Collaterals.This paper deals with different aspects of risky debt valuation with the CCA approach. The term. "risky", refers to the probability of default on the promised payment by the borrower. Paper 6: Portfolio Selection and the Pricing of Personal Loan Contracts.The CCA literature that follows Black and Scholes (1973), has mainly taken the underlying asset dynamics for given. Although it may be appropriate for stock options, we consider this assumption too simplifying with regards to personal loan contracts. It is obvious that the borrower’s consumption-investment decision affects his wealth process, on which the loan contract is contingent. Moreover, we believe that individuals actually have preferences to repay loans for different reasons such as the existence of reputational costs or legal penalties that affect the borrower in case of loan default. / Diss. av båda förf.  Stockholm : Handelshögskolan

A low content of organic matter, which is largely refractory in nature, is characteristic of most sediments, meaning that aquatic deposit-feeders live on a very poor food source. The food is derived mainly from sedimenting phytodetritus, and in temperate waters like the Baltic Sea, from seasonal phytoplankton blooms. Deposit-feeders are either bulk-feeders, or selective feeders, which preferentially ingest the more organic-rich particles in the sediment, including phytodetritus, microbes and meiofauna. The soft-bottom benthos of the Baltic Sea has low species biodiversity and is dominated by a few macrobenthic species, among which the most numerous are the two deposit-feeding amphipods Monoporeia affinis and Pontoporeia femorata, and the bivalve Macoma balthica. This thesis is based on laboratory experiments on the feeding of these three species, and on the priapulid Halicryptus spinulosus. Feeding by benthic animals is often difficult to observe, but can be effectively studied by the use of tracers. Here we used the radioactive isotope 14C to label food items and to trace the organic matter uptake in the animals, while the stable isotopes 13C and 15N were used to follow feeding on aged organic matter in the sediment. The abundance of M. balthica and the amphipods tends to be negatively correlated, i.e., fewer bivalves are found at sites with dense populations of amphipods, with the known explanation that newly settled M. balthica spat are killed by the amphipods. Whether the postlarvae are just accidentally killed, or also ingested after being killed was tested by labelling the postlarvae with 14C and Rhodamine B. Both tracer techniques gave similar evidence for predation on and ingestion of postlarval bivalves. We calculated that this predation was likely to supply less than one percent of the daily carbon requirement for M. affinis, but might nevertheless be an important factor limiting recruitment of M. balthica. The two amphipods M. affinis and P. femorata are partly vertically segregated in the sediment, but whether they also feed at different depths was unknown. By adding fresh 14C-labelled algae either on the sediment surface or mixed into the sediment, we were able to distinguish surface from subsurface feeding. We found M. affinis and P. femorata to be surface and subsurface deposit-feeders, respectively. Whether the amphipods also feed on old organic matter, was studied by adding fresh 14C-labelled algae on the sediment surface, and using aged, one-year-old 13C- and 15N-labelled sediment as deep sediment. Ingestion of old organic matter, traced by the stable isotopes, differed between the two species, with a higher uptake for P. femorata, suggesting that P. femorata utilises the older, deeper-buried organic matter to a greater extent. Feeding studies with juveniles of both M. affinis and P. femorata had not been done previously. In an experiment with the same procedure and treatments as for the adults, juveniles of both amphipod species were found to have similar feeding strategies. They fed on both fresh and old sediment, with no partitioning of food resources, making them likely to be competitors for the same food resource. Oxygen deficiency has become more wide-spread in the Baltic Sea proper in the last half-century, and upwards of 70 000km2 are now devoid of macrofauna, even though part of that area does not have oxygen concentrations low enough to directly kill the macrofauna. We made week-long experiments on the rate of feeding on 14C-labelled diatoms spread on the sediment surface in different oxygen concentrations for both the amphipod species, M. balthica and H. spinulosus. The amphipods were the most sensitive to oxygen deficiency and showed reduced feeding and lower survival at low oxygen concentrations. M. balthica showed reduced feeding at the lowest oxygen concentration, but no mortality increase. The survival of H. spinulosus was unaffected, but it did not feed, showing that it is not a surface deposit-feeder. We conclude that low oxygen concentrations that are not directly lethal, but reduce food intake, may lead to starvation and death in the longer term.

The Glacier Creek volcanogenic massive sulfide (VMS) deposit is hosted within Late Triassic, oceanic back-arc or intra-arc, rift-related, bimodal volcanic rocks (Hyd or Tats Group) of the allochthonous Alexander terrane known as the Alexander Triassic Metallogenic Belt (ATMB). The deposit presently consists of four tabular massive sulfide lenses with a resource of 4.75 Mt. at 1.84% Cu, 4.57% Zn, 0.15% Pb, 0.28 g/t Au and 29.07 g/t Ag. A deposit-scale thrust fault offsets stratigraphy along the axial surface of a deposit-scale anticline. The massive sulfide lenses are barite-rich and are divided into 6 main ore-types based on mineral assemblages. There is a large range of sphalerite compositions, with low-Fe sphalerite dominant throughout the lenses and high-Fe sphalerite at the top and bottom of the lenses in pyrrhotite-rich zones. Lenses contain anomalous Sb, Hg and Tl. Gangue minerals include barite, quartz, barian-muscovite, calcite, albite, highly subordinate chlorite and locally hyalophane and celsian. Overlying massive sulfide is a tuffaceous hydrothermal sediment with anomalous REE patterns and local hyalophane. The general footwall to all four lenses is a thick unit of coherent to volcaniclastic feldspar-phyric basalt containing extensive lateral alteration. Four alteration facies are recognized based on mineral assemblages. Mass balance calculations for the footwall indicate general gains of S, Fe, Si and K with coincident loss of Ca, Na and Mg, along with trace element gains of Tl, Sb, Hg, Ba, Zn, Cu, As and loss of Sr with increased alteration intensity. Short wavelength infrared (SWIR) spectroscopy shows a general decrease in Na, K and Al content of muscovite and increase of Fe+Mg and Ba content towards ore. Integrated petrographic, mineral, chemical and sulfur-isotope data suggest a transition during deposit formation, from high-temperature, acidic, reduced hydrothermal fluids mixing with oxidized, SO4-rich seawater, to later cooler, low fO2-fS2 conditions of formation and a lack of SO4 in seawater.

Two eruptions from Icelandic volcanoes have in the last years caused widespread dispersalof volcanic ash in the atmosphere. The transportation of tephra from Iceland to mainlandEurope is not an uncommon event and it can cause large disruptions to society. In thisthesis I present the ndings of a tephrochronological study of recent sediment from a bogcalled Trolls mosse in southern Sweden. The results show the presence of recent tephrafrom what is most likely the Grímsvötn eruption in May 2011, but geochemical analysisof the tephra could not conrm the exact origin of it, and a possibility that the Eyafjal-lajökull eruption also has contributed exists. By correlating atmospheric data about thelocation of the ash clouds produced during the eruptions and tephrochronological studiesof where tephra fallout has occurred could improve our understanding of tephra falloutdynamics and could help understand complex fallout patterns for past eruptions.

To characterize the size distributions, concentrations and sources of heavy metal associated with suspended particles, a total of 12 months of sampling periods were taken by Micro-Orifice Uniform Deposit Impactor (MOUDI) in the Nantzu Export Processing Zone from January to December 2011, The concentrations of suspended particles ranged from 54.7 to 203 £gg/m3. Both autumn and winter had significantly higher levels of suspended particles than in spring and summer. The mass concentrations of fine particles accounted for ~50% of the mass concentrations of suspended particles. The mass concentrations of PM2.5 accounted for 50.2-70% of the mass concentrations of PM10. The mass concentrations of PM1 accounted for 24-38.3% of the mass concentrations of PM10. These results indicated that fine particles dominated in atmospheric particulates in Nanzih Export Processing Zone. In addition, among the PM10, PM2.5 and PM1, significant correlations were found. The crustal elements (Al, Fe, Ca, Mg, K and Na) and sulfate are dominant during the sampling periods, which accounting for ~95% of the total concentrations. The crustal elements were observed mainly in coarse particles, while sulfate was found mainly in fine particles. The concentrations of all crustal elements decreased in summer could be attributed to the meteorological conditions and chemical mechanism. By using the enrichment factor (EF) to distinguish the sources of heavy metals in PM10, PM2.5 and the results showed that EF values of crustal elements in PM10 ranged from 1 to 10, suggesting PM10 might come from the resuspension of soil and road dust. In addition, Pb, Zn, As, Se, Mo, Sb and sulfate were observed at higher EF values in both PM2.5 and PM1, indicating the influence of anthropogenic emissions in fine particles. The results from Pearson¡¦s correlations indicated that PM10 in the Nantzu Processing Zone were mainly from the resuspension of soil and road dust, while fine particles (PM2.5 and PM1) may be from the traffic emissions and petrochemical industry in Nanzih and Renwu.

タンデトロン加速器質量分析計業績報告 Summaries of Researches Using AMS 2002 (平成14)年度

Atherosclerosis and specifically rupture of vulnerable plaques account for 23% of all deaths worldwide, far surpassing both infectious diseases and cancer. Plaque-based macrophages, often associated with lipid deposits, contribute to atherogenesis from initiation through progression, plaque rupture and ultimately, thrombosis. Therefore, the macrophage is an important early cellular marker related to vulnerability of atherosclerotic plaques. The objective of my research is to assess the ability of multiple optical imaging modalities to detect, and further characterize the distribution of macrophages (having taken up plasmonic gold nanoparticles as a contrast agent) and lipid deposits in atherosclerotic plaques. Tissue phantoms and macrophage cell cultures were used to investigate the capability of nanorose as an imaging contrast agent to target macrophages. Ex vivo aorta segments from a rabbit model of atherosclerosis after intravenous nanorose injection were imaged by optical coherence tomography (OCT), photothermal imaging (PTW) and two-photon luminescence microscopy (TPLM), respectively. OCT images depicted detailed surface structure of atherosclerotic plaques. PTW images identified nanorose-loaded macrophages (confirmed by co-registration of a TPLM image and corresponding RAM-11 stain on a histological section) associated with lipid deposits at multiple depths. TPLM images showed three-dimensional distribution of nanorose-loaded macrophages with a high spatial resolution. Imaging results suggest that superficial nanorose-loaded macrophages are distributed at shoulders on the upstream side of atherosclerotic plaques at the edges of lipid deposits. Combination of OCT with PTW or TPLM can simultaneously reveal plaque structure and composition, permitting assessment of plaque vulnerability during cardiovascular interventions. / text

This dissertation advances our understanding of how turbidity currents interact with three-dimensional (3-D) minibasin topography and the resulting deposits that form. Conceptual Gulf of Mexico-centric models of minibasin fill development have become the foundation for exploring and identifying strategic deep-water hydrocarbon reserves on continental slopes around the world. Despite the abundance of subsurface data, significant questions remain about the 3-D physical processes through which minibasins fill and the relationship between these processes and the topography of the basin. To overcome this problem, I utilize techniques in physical laboratory modeling to query established models of the role that turbidity currents play in minibasin fill development, and observe the relationships between fill from the Lobster minibasin located in a proximal continental slope position in the Gulf of Mexico and from the Safi Haute Mer (SHM) minibasin located in the distal continental slope of offshore western Morocco. First, existing published literature are reviewed and assessed for the known state of minibasin development and fill processes, and the strengths and weaknesses of our current knowledge base. Second, results are presented from two series of experiments that document the interaction between steady, depletive turbidity currents and 3-D minibasin topography. Experimental results suggest that turbidity currents produce deposits that are more likely to drape pre-flow topography than pond within it. Turbidity current velocity data show a strong 3-D physical component in minibasin fill sedimentation that also influences extra-basinal sedimentation patterns. Details of these results provide insight into processes that have not been previously considered in published conceptual models of minibasin fill. Third, a comparison of the two subsurface datasets show that the types and abundance of architectural elements vary depending on the location of the minibasin on the continental slope (i.e. proximal vs. distal), and suggests key differences in the processes responsible for their infilling. Finally, a comparison of experimental results to preserved deposit architectures in the Lobster and SHM datasets suggest a more complex relationship of process-driven sedimentation than that derived primarily from suspension fallout. This improved understanding of minibasin fill is applicable to industry for increasing confidence in subsurface interpretations and reducing risk while exploring for quality reservoirs in deepwater regions. / text

Slope-channels act as conduits that transport sediments from the shelf staging area to the basin floor. The Pliocene-Pleistocene section of the Columbus Basin in the deep-water slope offshore eastern Trinidad provides an opportunity to study slope-channel morphology and evolution, as well as any association between deep-water deposits, palaeo-seafloor bathymetry, shelf sediment feeder mechanism and changes in sediment supply types and volumes. Approximately 3250 km2 of 3D seismic data allow imaging and interpretation of channels within an interval between two regional surfaces termed P30 and P40. Observations of seismic cross-sections and stratal slices reveal a number of features including channels, mud diapirs, mass transport deposits (MTDs), and faulted anticlinal ridges. Channels appear leveed and unleveed, and alternate with MTDs in a cyclic vertical succession. Nineteen channels were mapped and divided into two groups based on their degree of levee development and stratigraphic position relative to MTDs. Group 1 channels, positioned below MTDs near the base of the interval, are shallowly incised, and show limited levee development. Group 2 channels, situated above MTDs, are relatively deeply incised, and have comparatively larger, well-developed levees throughout their lengths. Morphometric data from these channel groups reveal significant variability in channel width, channel depth, meander belt width, and sinuosity downslope. This variability is associated with influences of temporally equivalent local features and regional sea-floor slope changes. Increased slope gradient causes a marked increase in sinuosity. Diapirs and anticlinal ridges confine channel paths, divert their flow, and cause post-depositional deformation of both levees and channels. Levee height decreases downslope while levee width shows considerable asymmetry, which is related to occurrences of mud diapirism and MTDs. Irregularities on the upper surface of MTDs create accommodation space that confines turbidity flows, enabling ponding of sediments and volumetrically large levee construction. This accounts for dispersion of turbidity flows below the MTD which creates a series of small channels spread over a wide area, and comparatively fewer, confined channels above the MTDs with large levees. / text

The study investigated preservation of, and access to, legal deposit materials at the Msunduzi Municipal Library. Constant access to legal deposit materials will depend on proper preservation methods from the time they are first produced. The focus was to identify how the different materials are preserved and stored, especially because every institution has unique needs, especially with regard to the climatic conditions of the area. The study also examined challenges faced by the depository, skills and knowledge of the depository staff about preventative preservation methods, resources for conservation and collection management strategies. The methods to help make materials accessible were established by examining the means and processes used. Methodological triangulation was used to look at the study in different ways and this included a questionnaire, interviews, observation and collection of graphic data. The units of analysis were the staff of the legal deposit department and the whole population was surveyed. In this study, quantitative and qualitative techniques were employed. The results of the self-administered question and observation schedule were analysed using SPSS. Data collected using the interview schedule was analysed qualitatively. The results of the study show that there are inadequate preservation activities and strategies for legal deposit materials at the Msunduzi Municipal Library. The legal deposit collection was at risk of being lost and inaccessible to present and future generations. This was mostly due to lack of preservation activities and strategies as a result of lack of knowledge in preservation, adequate funding, staff training, preservation policies, environmental control of stack rooms and the proper handling and storage of materials. / Thesis (M.I.S.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.