A train of attosecond pulses, synchronized to an infrared (IR) laser field, is used to create a series of electron wave packets (EWPs) that are below the ionization threshold in .helium. The ionization probability is found to strongly oscillate with the delay between the IR and attosecond fields twice per IR laser cycle. Calculations that reproduce the experimental results demonstrate that this io

Since about 25 years ago work has been dedicated to the development of hydrodynamical model atmospheres for cool stars (of A to T spectral type). Despite their obviously sounder physical foundation in comparison with standard hydrostatic models, their general application has been rather limited. In order to understand why this is, and how to progress, we review the present status of hydrodynamical

OBJECTIVE: Although clinically approved for myelodysplastic syndromes (MDS), the mode of action of 5-azacytidine has not been well understood at the cellular level. The present study aimed at characterizing the mechanisms for 5-azacytidine-induced apoptosis, as well as the presence of a possible link between apoptosis and DNA hypomethylation. MATERIALS AND METHODS: We investigated the effects of 5

One of the most ubiquitous phenomena of all natural populations is their variability in numbers in space and time. However, there are notable differences among populations in the way the population size fluctuates. One of the major challenges in population and community ecology is to explain and understand this variety and to find possible underlying rules that might be modified from case-to-case.

Molecularly imprinted polymer microspheres were prepared by precipitation polymerization using a sacrificial covalent bond. In the present model, cholesteryl (4-vinyl)phenyl carbonate was used as a template monomer. The imprinted microspheres were prepared using ethylene glycol dimethacrylate (EDMA) and divinylbenzene (DVB) as crosslinker. The base-labile carbonate ester bond was easily hydrolyzed

Patients often worry considerably about biomedically mild and self-limiting conditions. A previous study on non-selected primary care patients showed that this could be partly explained by frequent associations with cases of serious illness in their family histories. This study further investigated these phenomena in middle aged men with a recent diagnosis of hypercholesterolaemia. Sixty-three out

Introduction Night nurses carry overall nursing responsibility for approximately half the time that patients spend in hospital. However, there is a paucity of literature that focuses on nursing care provided at night. Aim The aim of this study was to evaluate nursing care provided at night from the perspective of both nurses and patients. Methods The study, which had an evaluative and a comparativ

A photon echo experiment has been performed using accumulated highly attenuated laser pulses. We show experimentally that the photon echo process can be performed with, on the average, less than one photon in each pair of excitation pulses. The results support an interpretation where this nonlinear process can be performed with, on the average, less than one photon shared between two of the optica

A single detailed kinetic mechanism for the oxidation and combustion of n-decane and n-heptane has been written by means of an automatic mechanism generator ( REACTION) developed in our laboratory. It shows a good prediction of the ignition delay time versus temperature for the oxidation of n-decane at 13 and 50 bar and n-heptane at 13 and 40 bar for different equivalence ratios. The n-decane/n-he

A parasite's shift to a new host may have serious evolutionary consequences, since host switching usually is associated with a change in virulence and may lead to the evolution of emerging diseases. This phenomenon remains insufficiently studied in wildlife. Here, we combine microscopic examination of blood films and PCR-based methods to investigate the natural host specificity of Haemoproteus and

Second forerunner approximations to the transmission and reflection kernels for a temporally dispersive, nonmagnetic, isotropic slab are obtained. Numerical results are presented for two different dispersion models and are compared with the second forerunner approximations. Finally, transmission and reflection kernels are used to reconstruct the first susceptibility moments of the material of the

This paper presents theory related to stability analysis and stability criteria relevant for observer-based feedback control systems. To this purpose, a special formulation of the Yakubovich-Kalman-Popov (YKP) lemma is provided. We exploit that controllability is not necessary for existence of Lur'e-Lyaptinov functions as used in stability criteria. Constructive means for dynamic output feedback s

The Euro50 is a proposed 50 m optical and infrared telescope. It will have thousands of control loops to keep the optics aligned under influence of wind, gravity and thermal loads. Cross-disciplinary integrated modeling is used to study the overall performance of the Euro50. A sub-model of the mechanical structure originates from finite element modeling. The optical performance is determined using

A class of piecewise affine hyperbolic maps on a bounded subset of the plane is considered. It is shown that if a map from this class is sufficiently area-expanding then almost surely this map has an absolutely continuous invariant measure.

Hur ser smärtan ut? Smärtan känns. Det vet varje människa. Men hur förhåller det sig med dess synlighet? Går smärtan att avbilda? ”I wanted to paint the scream more than the horror”, förklarade Francis Bacon, smärtans och fasans okrönte mästare som på duk efter duk avbildade skrikande, ångestridna och vanställda kroppar. Och är det inte precis så det förhåller sig med våra försök att avbilda smärt