2,483 research outputs found
Using hospital readmission rates to track the quality of care in public hospitals in Singapore
Two-Component Fokker-Planck Models for the Evolution of Isolated Globular Clusters
Two-component (normal and degenerate stars) models are the simplest
realization of clusters with a mass spectrum because high mass stars evolve
quickly into degenerates, while low mass stars remain on the main-sequence for
the age of the universe. Here we examine the evolution of isolated globular
clusters using two-component Fokker-Planck (FP) models that include heating by
binaries formed in tidal capture and in three-body encounters. Three-body
binary heating dominates and the postcollapse expansion is self-similar, at
least in models with total mass M <= 3 x 10^5 M_\odot, initial half-mass radius
r_{h,i} >= 5 pc, component mass ratio m_2/m_1 <= 2, and number ratio N_1/N_2 <=
300 when m_2=1.4 M_\odot. We derive scaling laws for \rho_c, v_c, r_c, and r_h
as functions of m_1/m_2, N, M, and time t from simple energy-balance arguments,
and these agree well with the FP simulations. We have studied the conditions
under which gravothermal oscillations (GTOs) occur. If E_{tot} and E_c are the
energies of the cluster and of the core, respectively, and t_{rh} and t_c are
their relaxation times, then \epsilon \equiv (E_{tot}/t_{rh})/(E_c/t_{rc}) is a
good predictor of GTOs: all models with \epsilon>0.01 are stable, and all but
one with \epsilon < 0.01 oscillate. We derive a scaling law for \epsilon
against N and m_1/m_2 and compared with our numerical results. Clusters with
larger m_2/m_1 or smaller N are stabler.Comment: 15 pages (LaTeX) with 8 figures. To appear in ApJ March 10, 1998
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Lyman alpha line formation in starbursting galaxies II. Extremely Thick, Dustless, and Static HI Media
The Lya line transfer in an extremely thick medium of neutral hydrogen is
investigated by adopting an accelerating scheme in our Monte Carlo code to skip
a large number of core or resonant scatterings. This scheme reduces computing
time significantly with no sacrifice in the accuracy of the results. We applied
this numerical method to the Lya transfer in a static, uniform, dustless, and
plane-parallel medium. Two types of photon sources have been considered, the
midplane source and the uniformly distributed sources. The emergent profiles
show double peaks and absorption trough at the line-center. We compared our
results with the analytic solutions derived by previous researchers, and
confirmed that both solutions are in good agreement with each other. We
investigated the directionality of the emergent Lya photons and found that limb
brightening is observed in slightly thick media while limb darkening appears in
extremely thick media. The behavior of the directionality is noted to follow
that of the Thomson scattered radiation in electron clouds, because both Lya
wing scattering and Thomson scattering share the same Rayleigh scattering phase
function. The mean number of wing scatterings just before escape is in exact
agreement with the prediction of the diffusion approximation. The Lya photons
constituting the inner part of the emergent profiles follow the relationship
derived from the diffusion approximation. We present a brief discussion on the
application of our results to the formation of Lya broad absorption troughs and
P-Cygni type Lya profiles seen in the UV spectra of starburst galaxies.Comment: 24 papges, 12 figures, The revised version submitted to Ap
Non-ancient solution of the Ricci flow
For any complete noncompact Khler manifold with nonnegative and
bounded holomorphic bisectional curvature,we provide the necessary and
sufficient condition for non-ancient solution to the Ricci flow in this paper.Comment: seven pages, latex fil
Preliminary Observations on the Effects In Vivo and In Vitro of Low Dose Laser on the Epithelia of the Bladder, Trachea and Tongue of the Mouse
The effects of low dose CW laser were studied by in vivo and in vitro systems. The experimental tissues that were used included bladders, tracheas and tongues as experimental tissues. Buddings (round surface projections) from the transitional epithelium of bladder were frequently observed 3 days after laser treatment in both in vivo and in vitro systems. The trachea and tongue were less affected. In both the in vivo and in vitro systems, some epithelial cells of the trachea showed decreased microvilli and cilia 3 days after treatment whereas the epithelial cells of the tongue revealed no response to laser treatment in both systems. Low dose laser, however, appeared to promote the rate of healing of experimental tongue ulcer: healing was about 1 day earlier in the laser treated than non-treated animals and vessel infiltration and epithelialization were detected earlier in the treated
Angle-resolved photoemission study of the rare-earth intermetallic compounds: RNi2Ge2(R=Eu,Gd)
Experimental energy bands mapped from normal-emission photoelectron spectra of EuNi2Ge2 and GdNi2Ge2(001)surfaces show four photoemission features that disperse in both materials in good agreement with band calculations. Segments of the Fermi surfaces mapped by angle-resolved photoemission spectroscopy in the ÎXPZ plane of the Brillouin zones for both EuNi2Ge2 and GdNi2Ge2 are in good agreement with band calculations. This Fermi surface segment changes when one electron is added to EuNi2Ge2, corresponding to GdNi2Ge2, based on the rigid-band approximation
NT1-Tau Is Increased in CSF and Plasma of CJD Patients, and Correlates with Disease Progression
This study investigates the diagnostic and prognostic potential of different forms of tau in biofluids from patients with Creutzfeldt-Jakob disease (CJD). Extracellular tau, which is molecularly heterogeneous, was measured using ultra-sensitive custom-made Simoa assays for N-terminal (NT1), mid-region, and full-length tau. We assessed cross-sectional CSF and plasma from healthy controls, patients with Alzheimerâs disease (AD) and CJD patients. Then, we evaluated the correlation of the best-performing tau assay (NT1-tau) with clinical severity and functional decline (using the MRC Prion Disease Rating Scale) in a longitudinal CJD cohort (n = 145). In a cross-sectional study, tau measured in CSF with the NT1 and mid-region Simoa assays, separated CJD (n = 15) from AD (n = 18) and controls (n = 21) with a diagnostic accuracy (AUCs: 0.98â1.00) comparable to or better than neurofilament light chain (NfL; AUCs: 0.96â0.99). In plasma, NT1-measured tau was elevated in CJD (n = 5) versus AD (n = 15) and controls (n = 15). Moreover, in CJD plasma (n = 145) NT1-tau levels correlated with stage and rate of disease progression, and the effect on clinical progression was modified by the PRNP codon 129. Our findings suggest that plasma NT1-tau shows promise as a minimally invasive diagnostic and prognostic biomarker of CJD, and should be further investigated for its potential to monitor disease progression and response to therapies
The triggering of MHD instabilities through photospheric footpoint motions
The results of 3D numerical simulations modelling the twisting of a coronal loop due to photospheric vortex motions are presented. The simulations are carried out using an initial purely axial field and an initial equilibrium configuration with twist, . The non-linear and resistive evolutions of the instability are followed. The magnetic field is twisted by the boundary motions into a loop which initially has boundary layers near the photospheric boundaries as has been suggested by previous work. The boundary motions increase the twist in the loop until it becomes unstable. For both cases the boundary twisting triggers the kink instability. In both cases a helical current structure wraps itself around the kinked central current. This current scales linearly with grid resolution indicating current sheet formation. For the cases studied 35-40% of the free magnetic energy is released. This is sufficient to explain the energy released in a compact loop flare
141PD: Whole body and intracranial efficacy of ceritinib in patients (pts) with crizotinib (CRZ) pretreated, ALK-rearranged (ALK+) non-small cell lung cancer (NSCLC) and baseline brain metastases (BM): Results from ASCEND-1 and ASCEND-2 trials
Lyman alpha line formation in starbursting galaxies I. Moderately thick, dustless, and static HI media
We investigate the Lyman alpha line transfer in nearby and high redshift
starbursting galaxies, where the effect of high optical depths and the role of
dust in the scattering medium are expected to be conspicuous and should be
treated in a very careful manner. We present our first results in dustless,
static, and uniform HI media with moderate Lyman alpha line center optical
depths \tau_0=10^{3-6}. We assume that the temperatures of media to be
T=10^{1-4}K, and use a Monte Carlo technique. We investigate the basic
processes of the line transfer and confirm the criterion of a\tau_0>10^3 for
the validity of diffusion approximation suggested by Neufeld in 1990, where
is the Voigt parameter. Adopting the model suggested by Tenorio-Tagle et al.,
we performed calculations on the Lyman alpha line formation for each
evolutionary stage of an expanding supershell. The emergent Lyman alpha
profiles are characterized by the double peaks and the absorption trough at the
line center. We found that the absorption troughs expected in most of the
evolutionary stages are not wide enough to be observed with current
instruments. However, the absorption trough in the Lyman alpha emission profile
from an expanding recombining supershell can be marginally detected.Comment: 38 pages, 12 figures, Accepted for publication in the Ap
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