Sökresultat

Filtyp

Din sökning på "*" gav 529814 sökträffar

Development of a system for determination of the C-13/C-12 isotopic ratio with high spatial resolution

Stable carbon isotopes play an important role in the interpretation of biological activity, particularly when the fossil record is studied. In combination with morphological and chemical data, isotopic information can be useful in paleontology and astrobiology. In this paper the development of a microanalytical ion beam system for the measurement of the carbon isotope ratio with high spatial resol

Analysis-by-synthesis speech coding with quantization noise modeling

Iii analysis-by-synthesis linear predictive coding (AbS-LPC) an LPC synthesis filter is combined with an analysis-by-synthesis search of the excitation signal. The synthesis filter is an estimator for the speech signal given the excitation. However in most AbS-LPC algorithms this estimator has no explicit model of the quantization noise, which is present in the excitation signal. This paper descri

Chips on wafers, or packing rectangles into grids

A set of rectangles S is said to be gridpacked if there exists a rectangular grid (not necessarily regular) such that every rectangle lies in the grid and there is at most one rectangle of S in each cell. The area of a grid packing is the area of a minimal bounding box that contains all the rectangles in the grid packing. We present an approximation algorithm that given a set S of rectangles and a

Lipid-Block Copolymer-Immiscibility

We have investigated the binary system of a triblock copolymer of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), EO5PO68EO5, in water. The ternary system with the same polymer, water and soybean phosphatidylcholine (lecithin) has also been studied. Small-angle X-ray scattering (SAXS), 2H NMR and differential scanning calorimetry (DSC) were used to characterize these systems. The phase

Mechanisms for Targeting of Proteins to Secretory Lysosomes of Haematopoietic Cells

Popular Abstract in Swedish Kroppens immunförsvar, vars uppgift är att skydda oss mot infektioner, består av ett antal olika celltyper som till stor del finns i blodet. Immunförsvaret kan indelas i två delar; ett medfött försvar som är likadant hos alla individer och ett försvar som byggs upp under individens livstid. Det senare utformas olika beroende på vilka bakterier och virus som individen utThe cells of the innate immune system are essential for the host's first line defence against infection. Among these cells the neutrophil granulocyte has a central role by the production of antibiotic proteins and peptides. These are targeted for storage in secretory lysosomes and other neutrophil granules for subsequent release by regulated secretion in an inflammatory process. However, the granu

Induction of myocarditis in rabbits injected with group A streptococci

Background & objectives: We have earlier proposed that group A streptococcal (GAS) immunoglobulin binding surface proteins (IgGBPs) might trigger anti-IgG production and immune complex formation leading to glomerulonephritis. In the present study, cardiac tissue material from rabbits injected with heat-killed GAS was investigated. Methods: Rabbits were injected intravenously with 10(9) colony

Invading herbivory: The golden apple snail alters ecosystem functioning in Asian wetlands

We investigated the effects of an exotic snail, the golden apple snail (Pomacea canaliculata) on biodiversity and ecosystem functioning in tropical wetland ecosystems. This large snail (up to 80-mm shell height) has invaded large parts of Southeast Asia during recent decades. A survey of natural wetlands in Thailand showed that high densities of the snail were associated with almost complete absen

Uniform semiclassical trace formula for U(3) -> SO(3) symmetry breaking

We develop a uniform semiclassical trace formula for the density of states of a three-dimensional isotropic harmonic oscillator (HO), perturbed by a term 1/4 epsilon r(4). This term breaks the U(3) symmetry of the HO, resulting in a spherical system with SO(3) symmetry. We first treat the anharmonic term for small e in semiclassical perturbation theory by integration of the action of the perturbed

Effect of inhaled fluticasone with and without salmeterol on airway inflammation in asthma

Background: The clinical benefit of combining long-acting beta(2)-agonists with inhaled corticosteroids rather than doubling the dose of corticosteroid has been well-documented. However, there are concerns that this might result in a masking of underlying airway inflammation. Objective: The aim of this study was to test the hypothesis that the addition of the long-acting beta(2)-agonist salmeterol

Optimized density gradient separation of leukocyte fractions from whole blood by adjustment of osmolarity

Some of the compounds used for density gradient separation of blood cells have high osmolarities at the concentrations needed to create the required specific densities. Several mixed media use a combination of hyperosmolar shrinkage and red cell aggregation to improve cell separation. Due to the characteristics of Percoll density gradient medium the density and osmolarity of the gradient can be co

Characterization of isoniazid-resistant strains of Mycobacterium tuberculosis on the basis of phenotypic properties and mutations in katG

Forty isoniazid-resistant Mycobacterium tuberculosis isolates were characterized on the basis of phenotypic properties (i.e., catalase activity, MIC of isoniazid, and growth pattern in the presence of 7 different concentrations of isoniazid) and alterations in the katG gene (codons 315 and 463). Three different growth patterns could be distinguished: concentration-dependent inhibition of growth wa

Three-dimensional outgrowth of a wood-rotting fungus added to a contaminated soil from a former gasworks site

The capability of wood-rotting fungi (WRF) to colonise contaminated soil is an important fungal characteristic in the development of WRF-based soil bioremediation, it is also important to have methods that monitor the presence of the WRF in the soil. In this lab-scale study, it was shown that it was possible to re-capture, localise and identify a brown-rot fungus, Antrodia vaillantii, after it has

Hyperplastic conotruncal endocardial cushions and transposition of great arteries in perlecan-null mice

Perlecan is a heparan-sulfate proteoglycan abundantly expressed in pericellular matrices and basement membranes during development. Inactivation of the perlecan gene in mice is lethal at two developmental stages: around E10 and around birth. We report a high incidence of malformations of the cardiac outflow tract in perlecan-deficient embryos. Complete transposition of great arteries was diagnosed