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We model collisions between pre-main-sequence stars using a smoothed particle hydrodynamics method. Assuming that all collisions lead to simple mergers, we use derived merger cross-sections to calculate the time-scale to make a 50-M-circle dot star by collisions within the core of a stellar cluster as a function of stellar number density. We show that a 50-M-circle dot star may be produced in this
The combination of high strain modulus from conventional light weight deflectometer (LWD) analysis and low strain modulus front LWD-induced seismic analysis would move the pavement community towards field characterization of non-linear soil stiffness for use in mechanistic-empirical pavement design. This paper explores the experimental and numerical analysis of surface seismic waves during convent
There has been recent speculation that the cores of intermediate-mass stars stripped of their envelopes by tidal interaction with the supermassive black hole in the Galactic Centre could form a population observationally similar to the so-called Sgr A* cluster or 'S' stars, which have close eccentric orbits around the hole. We model the evolution of such stars, and show that the more luminous end
We summarize here the results of a major eight-year investigation of the extraordinarily detailed UV spectrum of the sharp-lined, nonmagnetic, main-sequence, chemically peculiar star chi Lupi (B9.5p HgMn + A2 Vm). The UV observations are composed of 345 Angstrom of the spectrum acquired with the Goddard High Resolution Spectrograph (GHRS) on board the Hubble Space Telescope at an average resolutio
An extensive set of water-H magnetic relaxation dispersion (MRD) data are presented for aqueous agarose and gelatin gels. It is demonstrated that the EMOR model, which was developed in a companion paper to this study (see Halle, this issue), accounts for the dependence of the water-H spin-lattice relaxation rate on resonance frequency over more than four decades and on pH. The parameter values ded
In spinal neurons, plateau potentials serve to amplify neuronal input signals. To a large extent, the underlying persistent inward current is mediated by a subtype of the L-type calcium channel (Ca(v)1.3). In the present investigation, we have studied its distribution and cellular localization in the cat spinal cord by light and electron microscopic immunohistochemistry. The results show that Ca(v
For women and children, especially those who are poor and disadvantaged, to benefit from primary health care, they need to access and use cost-effective interventions for maternal, newborn, and child health. The challenge facing weak health systems is how to deliver such packages. Experiences from countries such as Iran, Malaysia, Sri Lanka, and China, and from projects in countries like Tanzania
Study Design. A retrospective study. Objective. To evaluate the reliability of computed tomography (CT) with low radiation dose in the assessment of implant status in patients with adolescent idiopathic scoliosis (AIS). Summary of Background Data. The use of all-pedicle screw construct in scoliosis corrective surgery continues to gain increasing popularity since their introduction 1994 although th
In recent years there have been some rather successful applications of a new variational technique for calculating the total energies of electronic systems. The new method is based on many-body perturbation theory and uses the one-electron Green function as the basic "variable" rather than the wave function of traditional variational calculations. It is the purpose of the present work to promote t
Obiectives: Ventricular septal rupture is a rare but feared complication after acute myocardial infarction. Most reports about outcome after surgical treatment are single center experiences. We investigated the results after surgical repair in all patients in Sweden during a 7-year period. Methods: All patients undergoing surgical repair 1992-1998 were identified with the aid of the Swedish Heart
Background and Aims: The hydrolysis of sphingomyelin (SM) generates key molecules regulating cell growth. Animal cancer studies support an inhibitory role for this pathway in the malignant transformation of the colonic mucosa. The activity of a specific intestinal alkaline sphingomyelinase (SMase), which hydrolyzes SM, is reduced in colorectal tumors. In this study we measured alkaline SMase activ
For recombinant xylose-utilizing Saccharomyces cerevisiae, ethanol yield and productivity is substantially lower on xylose than on glucose. In contrast to glucose, xylose is a novel substrate for S. cerevisiae and it is not known how this substrate is recognized on a molecular level. Failure to activate appropriate genes during xylose-utilization has the potential to result in sub-optimal metaboli
The phase behavior of water/n-octane/n-octyl-beta-D-glucopyranoside (C(8)G(1))/1-octanol (C8E0) permits formulating temperature-insensitive microemulsions spanning the whole water-oil composition range. The types of microstructures formed along the trajectory of the middle-phase microemulsion are examined by NMR diffusometry, yielding the respective diffusion coefficients of all the components. Th
Abstract in UndeterminedThree different inverse problems for the Schrodinger operator on a metric tree are considered, so far with standard boundary conditions at the vertices. These inverse problems are connected with the matrix Titchmarsh-Weyl function, response operator ( dynamic Dirichlet-to-Neumann map) and scattering matrix. Our approach is based on the boundary control ( BC) method and in p
Cosmological long-duration gamma-ray bursts (LGRBs) are thought to originate from the core collapse to black holes (BHs) of stripped massive stars. Those with sufficient rotation form a centrifugally supported torus whose collapse powers the GRB. We investigate the role of tidal locking within a tight binary as a source of the necessary angular momentum. We find that the binary orbit must be no wi
The seasonal decline in reproductive success observed in many animal species may be caused by timing per se (timing hypothesis) or by variation in phenotypic quality between early and late breeding females (quality hypothesis). To distinguish between these two hypotheses, several studies of birds have used clutch removal experiments to manipulate breeding date. However; removal experiments also in
The static (parallel-plate thermal-gradient) diffusion chamber (SDC) was one of the first instruments designed to measure cloud condensation nuclei (CCN) concentrations as a function of supersaturation. It has probably also been the most widely used type of CCN counter. This paper describes the detailed experimental characterization of a SDC CCN counter, including calibration with respect to super
