9,750 research outputs found
Systemic infections after acute stroke
After an acute stroke, systemic infection can complicate the recovery process and lead to a worse clinical outcome, including a higher risk of mortality. Post-stroke infection (PSI) is responsible for the majority of the mortality occurring between 1 week and 1 month after stroke, peaking towards the end of the second week. The effects of PSI on longer-term outcome and other aspects of recovery, such as cognition, mood and quality of life, are largely unknown. The cerebrovascular event itself may result in a systemic immunosuppressed state, hence lowering the threshold for subsequent systemic bacterial infections. Although there have been advances in the basic understanding of the pathophysiological mechanisms of PSI, clinical studies have not provided any clear guidelines on the best methods of managing or preventing PSI. This article provides a review of the current knowledge of the phenomenon of PSI and the possible future developments in the understanding and treatment of PSI
Adapting the large neighborhood search to effectively solve pickup and delivery problems with time windows
Pickup and delivery problems with time windows (PDP-TW) are challenging combinatorial optimization problems widely occurring in modern distribution and transportation industry. A previous proposal successfully adapted and combined the well-known push forward insertion heuristic (PFIH) with a new repair-based swap operator as a computationally reduced version of the Large Neighborhood Search (LNS) to efficiently solve the PDP-TWs. In this paper, we focus on a more systematic scheme to adapt the LNS in order to effectively solve PDP-TWs. Up to our knowledge, this work represents the first attempt to systematically adapt LNS for solving PDP-TWs. Besides, the empirical results obtained by our search proposals affirmed the attractive capability of the LNS approach to effectively reduce the total distance traveled in solving PDP-TWs, with similar results also achieved by the original LNS method in tackling the conventional vehicle routing problems with time windows. Lastly, our proposal of adapting LNS to solve hard combinatorial problems opens up many possible directions for future investigations. Ā© 2004 IEEE.published_or_final_versio
Severity of cardiovascular disease and health-related quality of life in men with prostate cancer: a longitudinal analysis from CaPSURE.
ObjectiveTo evaluate the influence of comorbid cardiovascular disease severity on health-related quality of life (HRQL) in men treated with radical prostatectomy (RP) or radiotherapy (RT) for early stage prostate cancer.MethodsSubjects (n=830) with non-metastatic disease who had been diagnosed in 2000-2002 were drawn from Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE). We evaluated the influence of cardiovascular disease (CVD) severity on generic and disease-specific HRQL before and 6, 12, 18, and 24 months after treatment with RP or RT. HRQL was measured with the SF-36 and the UCLA Prostate Cancer Index.ResultsMen with moderate (n=193) or severe (n=51) cardiovascular disease had worse pre-treatment HRQL than did men without CVD (n=293) (P<0.01); HRQL scores were worse in men referred for RT. During 24 months of follow-up, men with moderate or severe CVD had worse SF-36 physical and mental component summaries and worse bowel function at all time points (P<0.05). Men with severe CVD also experienced a slower recovery in physical function (P=0.03) and sexual functioning (P=0.02) than did men without CVD.ConclusionsProstate cancer patients with moderate to severe CVD have worse HRQL during follow-up. Those with severe CVD recover their physical and sexual functioning more slowly after treatment
A proposal for a scalable universal bosonic simulator using individually trapped ions
We describe a possible architecture to implement a universal bosonic
simulator (UBS) using trapped ions. Single ions are confined in individual
traps, and their motional states represent the bosonic modes. Single-mode
linear operators, nonlinear phase-shifts, and linear beam splitters can be
realized by precisely controlling the trapping potentials. All the processes in
a bosonic simulation, except the initialization and the readout, can be
conducted beyond the Lamb-Dicke regime. Aspects of our proposal can also be
applied to split adiabatically a pair of ions in a single trap
Pre-corneal tear film thickness in humans measured with a novel technique.
PurposeThe purpose of this work was to gather preliminary data in normals and dry eye subjects, using a new, non-invasive imaging platform to measure the thickness of pre-corneal tear film.MethodsHuman subjects were screened for dry eye and classified as dry or normal. Tear film thickness over the inferior paracentral cornea was measured using laser illumination and a complementary metal-oxide-semiconductor (CMOS) camera. A previously developed mathematical model was used to calculate the thickness of the tear film by applying the principle of spatial auto-correlation function (ACF).ResultsMean tear film thickness values (Ā±SD) were 3.05 Ī¼m (0.20) and 2.48 Ī¼m (0.32) on the initial visit for normals (n=18) and dry eye subjects (n=22), respectively, and were significantly different (p<0.001, 2-sample t-test). Repeatability was good between visit 1 and 2 for normals (intraclass correlation coefficient [ICC]=0.935) and dry eye subjects (ICC=0.950). Tear film thickness increased above baseline for the dry eye subjects following viscous drop instillation and remained significantly elevated for up to approximately 32 min (n=20; p<0.05 until 32 min; general linear mixed model and Dunnett's tests).ConclusionsThis technique for imaging the ocular surface appears to provide tear thickness values in agreement with other non-invasive methods. Moreover, the technique can differentiate between normal and dry eye patient types
Phase transition in a spring-block model of surface fracture
A simple and robust spring-block model obeying threshold dynamics is
introduced to study surface fracture of an overlayer subject to stress induced
by adhesion to a substrate. We find a novel phase transition in the crack
morphology and fragment-size statistics when the strain and the substrate
coupling are varied. Across the transition, the cracks display in succession
short-range, power-law and long-range correlations. The study of stress release
prior to cracking yields useful information on the cracking process.Comment: RevTeX, 4 pages, 4 Postscript figures included using epsfi
Disc wind in the HH 30 binary models
Recent interferometric observations of the young stellar object(YSO) HH 30
have revealed a low velocity outflow in the CO J=1-2 molecule line (Pety
et al. 2006). We present here two models of the low velocity disc winds with
the aim of investigating an origin of this molecular outflow. Following Andlada
et al. (2006) we treated HH 30 as a binary system. Two cases have been
considered: i) the orbital period = 53 yrs and ii) 1 yr.
Calculations showed that in the first case the outflow cone had a spiral-like
structure due to summing the velocities of the orbital motion and the disc
wind. Such a structure contradicts the observations. In the second case, the
outflow cone demonstrates a symmetry relatively to the system axis and agrees
well with the observations.Comment: 5 pages, 4 figures. accepted by Mon. Not. R. Astron. So
Large-Scale Structure in Brane-Induced Gravity II. Numerical Simulations
We use N-body simulations to study the nonlinear structure formation in
brane-induced gravity, developing a new method that requires alternate use of
Fast Fourier Transforms and relaxation. This enables us to compute the
nonlinear matter power spectrum and bispectrum, the halo mass function, and the
halo bias. From the simulation results, we confirm the expectations based on
analytic arguments that the Vainshtein mechanism does operate as anticipated,
with the density power spectrum approaching that of standard gravity within a
modified background evolution in the nonlinear regime. The transition is very
broad and there is no well defined Vainshtein scale, but roughly this
corresponds to k_*~ 2 at redshift z=1 and k_*~ 1 at z=0. We checked that while
extrinsic curvature fluctuations go nonlinear, and the dynamics of the
brane-bending mode C receives important nonlinear corrections, this mode does
get suppressed compared to density perturbations, effectively decoupling from
the standard gravity sector. At the same time, there is no violation of the
weak field limit for metric perturbations associated with C. We find good
agreement between our measurements and the predictions for the nonlinear power
spectrum presented in paper I, that rely on a renormalization of the linear
spectrum due to nonlinearities in the modified gravity sector. A similar
prediction for the mass function shows the right trends. Our simulations also
confirm the induced change in the bispectrum configuration dependence predicted
in paper I.Comment: 19 pages, 13 figures. v2: corrected typos, added more simulations,
better test of predictions in large mass regime. v3: minor changes, published
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