Search results

Filter

Filetype

Your search for "*" yielded 532721 hits

Measurement of helicity-dependent photoabsorption cross sections on the neutron from 815 to 1825 MeV

Helicity-dependent total photoabsorption cross sections on the deuteron have been measured for the first time at ELSA (Bonn) in the photon energy range from 815 to 1825 MeV. Circularly polarized tagged photons impinging on a longitudinally polarized LiD target have been used together with a highly efficient 4 pi detector system. The data around 1 GeV are not compatible with predictions from existi

FLT3 mutations confer enhanced proliferation and survival properties to multipotent progenitors in a murine model of chronic myelomonocytic leukemia

Despite their known transforming properties, the effects of leukemogenic FLT3-ITD mutations on hematopoietic stem and multipotent progenitor cells and on hematopoietic differentiation are not well understood. We report a mouse model harboring an ITD in the murine Flt3 locus that develops myeloproliferative disease resembling CMML and further identified FLT3-ITD mutations in a subset of human CMML.

Home Bias in European Countries within a Bayesian Framework

This paper determines to what extent the estimated expect returns on European equity indices will be affected by different degrees of prior confidence in the ICAPM. We also measure how fragile the investors’ prior confidence in ICAPM should be in order to explain the home bias of European pension funds. A Bayesian approach is used to estimate the expected asset returns under different prior scenar

Distinct roles of integrins {alpha}6 and {alpha}4 in homing of fetal liver hematopoietic stem and progenitor cells.

Homing of hematopoietic stem cells (HSCs) into the bone marrow (BM) is a prerequisite for establishment of hematopoiesis during development and following transplantation. However, the molecular interactions that control homing of HSCs, in particular, of fetal HSCs, are not well understood. Herein, we studied the role of the alpha 6 and alpha A integrin receptors for homing and engraftment of fetal

Boronate-containing polymer brushes: Characterization, interaction with saccharides and mammalian cancer cells.

Boronate-containing polymer brushes were synthesized by free radical copolymerization of N,N-dimethylacrylamide (DMAA) and N-acryloyl-m-phenylboronic acid (NAAPBA) (9:1) on the surface of 3-mercaptopropyl-silylated glass plates and capillaries. The brushes were characterized with time-of-flight secondary ion mass-spectrometry (ToF SIMS), atomic force microscopy and contact angle measurements. Fruc

ARAGORN, a program to detect tRNA genes and tmRNA genes in nucleotide sequences

A computer program, ARAGORN, identifies tRNA and tmRNA genes. The program employs heuristic algorithms to predict tRNA secondary structure, based on homology with recognized tRNA consensus sequences and ability to form a base-paired cloverleaf. tmRNA genes are identified using a modified version of the BRUCE program. ARAGORN achieves a detection sensitivity of 99% from a set of 1290 eubacterial, e

Assessing the extraction and quantification of amorphous silica in soils of forest and grassland ecosystems

The objective of this study was to evaluate different methodologies with regard to their ability to extract the amorphous silica (ASi) content of soils from diverse geochemical settings. The methods used in this work included three acid extraction techniques (oxalate, citrate and acetate) and two alkaline extraction techniques (sodium carbonate and sodium hydroxide) which are more commonly used fo

Leukocyte adhesion in aorta and femoral artery in vivo is mediated by LFA-1

Objective: Cytokine-induced recruitment of leukocytes is an early feature during arterial injury and atherosclerotic plaque formation. The aim of this study was to analyze the role of the beta(2)-integrin lymphocyte function-associated antigen-1 (LFA- 1; CD11a/CD18) in cytokine-triggered firm leukocyte adhesion to arterial endothelium in vivo. Material and Methods: Intravital fluorescence microsco

Short-range structure of proton-conducting perovskite BaInxZr1-xO3-x/2 (x=0-0.75)

In a systematic study, we investigate the effect of dopant level and hydration on the short-range structure of the proton-conducting perovskite-type oxide BaInxZr1-xO3-x/2 (x = 0 - 0.75), using infrared and Raman spectroscopy. The results show that the doping leads to significant local distortions of the average cubic structure of these materials. By increasing the In concentration from x = 0 to x

Outline of a convergence proof for compact difference methods applied to nonlinear initial-boundary value problems.

An initial-boundary value problem to a system of nonlinear partial differential equations, which consists of a hyperbolic and a parabolic part, is taken into consideration. The problem is discretised by a compact finite difference method. An approximation of the numerical solution is constructed, at which the difference scheme is linearised. Nonlinear convergence is proved using the stability of t

Long- and short-term state-dependent foraging under predation risk: an indication of habitat quality

Animals living in environments of different quality will have different expectations of their future reproductive success and survival. This may affect the individual's risk-taking behaviour as manifest in the cost of predation. We investigated the foraging behaviour of starlings, Sturnus vulgaris, when perceived predation risk varied between patches. Short-term food availability varied between tr

Contemporary evolution of secondary sexual traits in the wild

1. Sexual selection has been studied intensively, and is often strong in natural populations. Theoretical models, comparative studies and laboratory selection experiments all suggest that evolution driven by sexual selection should be rapid and common. 2. However, there are relatively few documented cases of the contemporary evolution of secondary sexual traits in natural populations. Moreover, th