BACKGROUND Biological variation data for free plasma amino acids are lacking from the more comprehensive databases. Therefore, we determined the intra- and inter-individual components of variation in healthy subjects. These data were used to define desirable goals for imprecision, bias and total error, indices of individuality and reference change values. METHODS Plasma samples were collected...

The nonsymmetric Lanczos tridiagonalization algorithm is essentially the Gram-Schmidt biorthogonalization method for generating biorthogonal bases of a pair of Krylov subspaces. It suffers from breakdown and instability when a pivot at some step is zero or nearly zero, which is often the result of mismatch of the two Krylov subspaces. In this paper, we propose to modify one of the two Krylov su...

Most watermark methods use pixel values or coefficients as the judgment condition to embed or extract a watermark image. The variation of these values may lead to the inaccurate condition such that an incorrect judgment has been laid out. To avoid this problem, we design a stable judgment mechanism, in which the outcome will not be seriously influenced by the variation. The principle of judgmen...

This paper presents the results of a corpus-based study of ten words exhibiting phonological free variation in their phonemic or accentual makeup. The study uses data from the News archives of the BBC Learning English website. The rates of use of the variants for each lexical item are given and discussed.

The two main plagues of image restoration are oscillations and smoothing. Traditional image restoration techniques prevent parasitic oscillations by resorting to smooth regularization. Hence, singular image features and oscillatory textures cannot be restored. The usefulness of images obtained by smooth regularization is very limited. Regularized faces and characters lose features and are unrec...

The abundance and heterotrophic activity of attached and free-living bacteria were examined seasonally in coastal water. Heterotrophic activity was determined by the uptake of [C]glucose. The density of attached bacteria was always minor, not showing a seasonal variation, whereas the free-living bacteria were more numerous and showed a marked seasonal variation, their density being higher under...

A differential cluster variation method (DCVM) is proposed for analysis of spinoidal decomposition in alloys. In this method, lattice symmetry operations in the presence of an infinitesimal composition gradient are utilized to deduce the connection equations for the correlation functions and to reduce the number of independent variables in the cluster variation analysis. Application of the meth...

the volumetric expansion coefficient has an importance in determination of the free convection heat transfer coefficient. the buoyant force in the fluid which is the result of the variation of fluid density with temperature, is proportional to this expansion coefficient, b. this coefficient of b varies with temperature and it is important to understand under what conditions it should be evaluat...

Genetic variation for fitness-relevant traits may be maintained in natural populations by fitness differences that depend on environmental conditions. For herbivores, plant quality and variation in chemical plant defences can maintain genetic variation in performance. Apart from plant secondary compounds, symbiosis between plants and endosymbiotic fungi (endophytes) can produce herbivore-toxic ...