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The value of a position in a risky asset when optimally sold in an illiquid market is considered. The optimization problem is described as a stochastic impulse control problem, and it is shown that it is related to solving a system of quasi-variational inequalities. Existence of a solution to these inequalities are proved. A numerical implementation of the valuation algorithm is discussed and two

To improve image quality in a vertical field MR imaging unit, operating at low field strength (0.3 T), we have designed a half-elliptical coil for use in the upper thoracic region of small children. Our intention was also to shorten the examination time, which until now has been long, because several scans with different coils have been necessary to cover the thoracic region. The experimental coil

Sixty-two patients with newly diagnosed sarcoidosis were examined with fibreoptic bronchoscopy, endobronchial biopsies and bronchoalveolar lavage (BAL) were analysed. Epithelioid granulomatosis in endobronchial biopsies were found in 28 (45%) of the patients (BPOS). The patients in this BPOS group showed higher inflammatory activity in BAL fluid compared to those with negative biopsies (BNEG), wit

Splitting failure in beam splice joints with glued-in rods parallel to grain in endwood subjected to pure shear is considered. A simple theoretical expression based on beam-on-elastic-foundation theory and quasi-non-linear fracture mechanics is presented for calculation of the joint strength. Tests were conducted on jointed beams in a four-point bending test setup in which the joints were located

Background: The hazards of elective splenectomy in the elderly have not been thoroughly investigated. The aim was to assess such a well-defined cohort with respect to perioperative and long-term outcome. Methods: Fifty-two consecutively splenectomised patients during the period 1971-1995, aged 65 years or older, were followed until death (44 cases) or the end of 1999 (8 cases). Results: No intraop

We present a new method, using Bayesian estimation, to determine stellar ages and their uncertainties from observational data and theoretical isochrones. The result for an individual star is obtained as the relative posterior probability density as function of the age ("G function"). From this can be derived the most probable age and confidence intervals. The convoluted morphology of isochrones an

The cat has served as an important nonrodent research model for neurophysiology and retinal degenerative disease processes, yet very little is known about feline neural precursor cells. To culture these cells and evaluate marker expression, brains were dissected from 45-day-old fetuses, enzymatically dissociated, and grown in the presence of EGF, bFGF and PDGF. Expanded cells widely expressed nest

Results from therapeutic trials with radiolabelled monoclonal antibodies are difficult to compare, because of lack of accurate macroscopic and microscopic dosimetry for both tumours and normal tissues. Requirements for such a dosimetry are covered in the paper. Accurate in vivo dosimetric measurement techniques for verification of calculated absorbed doses are also needed to verify treatment plann

1. Responses of zooplankton to nutrient enrichment and fish predation were studied in 1998 and 1999 by carrying out parallel mesocosm experiments in six lakes across Europe. 2. Zooplankton community structure, biomass and responses to nutrient and fish manipulation showed geographical and year-to-year differences. Fish had a greater influence than nutrients in regulating zooplankton biomass and es

Bird migration was recorded by tracking radar and visual observation at 23 sites in the region of the Northwest Passage, between Baffin Island and Herschel Island in the Beaufort Sea. The studies took place during a ship-based expedition from 29 June to 3 September 1999. A total of 692 tracks (average duration 160 s) of bird flocks on postbreeding migration were recorded. Eastward migration was wi

The present study concerns heat and mass transfer in porous media dried by superheated steam. Specifically, the steam drying process of a packed bed of porous particles was studied in order to obtain design data for a band drier. The small scale averaged governing equations describing the heat and mass transfer within the porous particles were derived. The inherent transport coefficients were eit

This thesis is a collection of six papers in computational algebra. In particular, we study noncommutative Gröb- ner bases, SAGBI bases and similar algebraic objects which can be represented as a graph or an automaton. In Paper I we introduce the concept of bi-automaton algebras, generalizing the automaton algebras previously defined by Ufnarovski. A bi-automaton algebra is a quotient of the free