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Numerical solution of fractional advection-dispersion equation

Numerical schemes and stability criteria are developed for solution of the one-dimensional fractional advection-dispersion equation (FRADE) derived by revising Fick's first law. Employing 74 sets of dye test data measured on natural streams, it is found that the fractional order F of the partial differential operator acting on the dispersion term varies around the most frequently occurring value o

Enhancement of poorly edible phytoplankton by allochthonous dissolved organic material: a modelling study

The effect of different input rates of dissolved inorganic (DIN) and organic (DON) nitrogen on a microbial food web was studied with the help of a mathematical model. Three species of phytoplankton were modelled, with trade-off characteristics for maximum per capita growth rate, half-saturation constant and edibility. Bacteria used only DON, while 2 different types of microzooplankton grazed on th

The meaning of quality work from the general practitioner's perspective: an interview study

BACKGROUND: The quality of health care and its costs have been a subject of considerable attention and lively discussion. Various methods have been introduced to measure, assess, and improve the quality of health care. Many professionals in health care have criticized quality work and its methods as being unsuitable for health care. The aim of the study was to obtain a deeper understanding of the

Methods in cell separations

Research in the field of cell biology and biomedicine relies on technologies that fractionate cell populations and isolate rare cell types to high purity. A brief overview of methods and commercially available products currently used in cell separations is presented. Cell fractionation by size and density and highly selective affinity-based technologies such as affinity chromatography, fluorescenc

Power mapping and noise reduction for financial correlations

The spectral properties of financial correlation matrices can show features known from completely random matrices. A major reason is noise originating from the finite lengths of the financial time series used to compute the correlation matrix elements. In recent years, various methods have been proposed to reduce this noise, i.e. to clean the correlation matrices. This is of direct practical relev

Job strain in men, but not in women, predicts a significant rise in blood pressure after 6.5 years of follow-up.

Background: Job strain (high demands and low decision latitude) has been associated with hypertension and cardiovascular disease, especially in men. Most studies on job strain and hypertension have been cross-sectional, and prospective data are inconsistent. Objective: To prospectively describe the effects of different psychosocial work characteristics on office blood pressure changes. Methods: In

A genetic basis of susceptibility to acute pyelonephritis.

Background For unknown reasons, urinary tract infections (UTIs) are clustered in certain individuals. Here we propose a novel, genetically determined cause of susceptibility to acute pyelonephritis, which is the most severe form of UTI. The IL-8 receptor, CXCR1, was identified as a candidate gene when mIL-8Rh mutant mice developed acute pyelonephritis (APN) with severe tissue damage. Methods and

Efficacy of human leucocyte alpha-interferon treatment for chronic hepatitis C virus infection

A total of 42 Swedish patients with biopsy-proven chronic hepatitis C virus (HCV) infection were treated with a natural human leucocyte alpha-interferon (HuIFN-alpha-Le), Alfanative (BioNative AB, Umeå, Sweden) in an open uncontrolled study. Two patients were withdrawn from treatment within 2 weeks due to non-compliance and were omitted from further analysis, and 40 patients (17 females), mean age

Direct evidence for the cytomembrane derivation of Birbeck granules: the membrane-sandwich effect

Digitonin, which is known to cause extensive damage to cytomembranes in general, was found to have a most remarkable effect on epidermal Langerhans' cells. Thus, it generates a membrane-sandwiching process resulting in the formation of large discs which except for the differences in size have the same morphology as ordinary Birbeck granules. This demonstrates that the cytomembrane of the Langerhan

Partitioning and characterization of tyrosine-tagged green fluorescent proteins in aqueous two-phase systems

The green fluorescent protein GFPuv has been genetically engineered to investigate the influence of N-terminal tyrosine extensions in aqueous two-phase systems. Fusions in the N-terminus affected the protein expression, and tags containing three tyrosines and prolines influenced the expression favorably. This effect is probably due to changes in mRNA stability, because the amounts of corresponding