1,919 research outputs found
906-61 Acoustic Quantification in the Infarcted Ventricle: Comparison with Electron Beam Computed Tomography
Assessment of LV size and function by acoustic quantification (AQ) correlates well with other techniques in patients with normally contracting ventricles. This prospective study examined the correlation between AQ and electron beam computed tomography (EBCT) volume measurements in patients with first anterior Q-wave MI and abnormally contracting ventricles. End-diastolic (EDV) and end-systolic (ESV) volumes by AQ were determined from standard four-chamber (4ch) and two-chamber (2ch) apical windows. The AQ tracings were transformed to volumetric measurements using the area-length (AL) and the modified Simpson's (mod.S) methods. EDV and ESV by EBCT were obtained conventionally by summation of manually traced LV areas on each short axis tomograms using Simpson's rule. Thirteen patients were imaged by both EBCT and echocardiography within 24 hours. EBCT-EDV ranged from 129–234ml (mean 173±34 ml and ESV from 58–109ml (mean 82±19 ml). The EDV and ESV by AQ, their correlation to EBCT and the accompanying pvalues are shown below:EDV-2chEDV-4chESV-2chESV-4chVol (ml)88±3097±3043±2050±22ALr0.760.560.580.34p0.0060.0490.0610.258Vol (ml)80±3390±3140±2145±20mod.Sr0.760.700.720.58p0.0060.0080.0120.037Conclusions[1] AQ underestimates absolute EDV and ESV measured by EBCT. [2] AQ-EDV correlates well with EBCT, particularly using the mod.S method. [3] AQ-ESV correlation to EBCT drops due to the asymmetric contraction pattern of infarcted ventricles. [4] The AL method's accuracy is particularly susceptible to asymmetric contraction in distorted ventricles. [5] Correction factors can be applied to account for the offset of EDV and ESV measurements by AQ
As tests evolve and costs of cancer care rise: reappraising stool-based screening for colorectal neoplasia
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73533/1/j.1365-2036.2008.03632.x.pd
Relative mobility determines the efficacy of MPAs in a two species mixed fishery with conflicting management objectives
Marine Protected Areas (MPAs) have been used to protect species in need of conservation and as a fisheries management tool. It has been suggested MPAs can benefit mobile stocks by protecting spawning grounds whilst also allowing yields to be maintained as mature fish move out of the protected areas. However, the robustness of this claim in mixed species fisheries has yet to be established. We use a simulation model to explore the efficacy of spatial closures and effort regulation when other forms of fishery control (e.g., Total Allowable Catches) are absent or non-enforced as ways of addressing management objectives that are difficult to reconcile due to the contrasting life-histories of a target and a bycatch, conservation species in a two-species fishery. The mobility of each stock in such a fishery affects the benefits conferred by an MPA. The differing management objectives of the two species can be partially met by effort regulations or closures when the species exhibit similar mobility. However, a more mobile conservation species prevents both sets of aims being met by either management tool. We use simulations to explore how spatial closures and effort regulation can be used to seek compromise between stakeholders when the mobility of one stock prevents conflicting management objectives to be fully met. Our results demonstrate that stock mobility is a key factor in considering whether an MPA can meet conflicting aims in a multispecies fishery compromised of stocks with differing life histories and mobilities
Embracing the Market: Entry into Self-Employment in Transitional China, 1978-1996
This paper introduces labor market transition as an intervening process by which the macro institutional transition to a market economy alters social stratification outcome. Rather than directly addressing income distribution, it examines the pattern of workers’ entry into self-employment in reform-era China (1978-1996), focusing on rural-urban differences and the temporal trend. Analyses of data from a national representative survey in China show that education, party membership and cadre status all deter urban workers’ entry into self-employment, while education promotes rural workers’ entry into self-employment. As marketization proceeds, the rate of entry into self-employment increases in both rural and urban China, but urban workers are increasingly more likely to take advantages of the new market opportunities. In urban China, college graduates and cadres are still less likely to be involved in self-employment, but they are becoming more likely to do so in the later phase of reform. The diversity of transition scenarios is attributed to rural-urban differences in labor market structures.http://deepblue.lib.umich.edu/bitstream/2027.42/39897/3/wp512.pd
Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV
The t t-bar production cross section (sigma[t t-bar]) is measured in
proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS
experiment, corresponding to an integrated luminosity of 2.3 inverse
femtobarns. The measurement is performed in events with two leptons (electrons
or muons) in the final state, at least two jets identified as jets originating
from b quarks, and the presence of an imbalance in transverse momentum. The
measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/-
2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction
of the standard model.Comment: Replaced with published version. Included journal reference and DO
- …