38,093 research outputs found
Growth index with the exact analytic solution of sub-horizon scale linear perturbation for dark energy models with constant equation of state
Three decades ago Heath found the integral form of the exact analytic growing
mode solution of the linear density perturbation on sub-horizon scales
including the cosmological constant or the curvature term. Recently, we
obtained the exact analytic form of this solution in our previous work
\cite{SK}. Interestingly, we are able to extend this solution for general dark
energy models with the constant equation of state in a flat
universe. This analytic solution provides the accurate and efficient tools for
probing the properties of dark energy models such as the behavior of the growth
factor and the growth index. We investigate the growth index and its parameter
at any epoch with this exact solution for different dark energy models and find
that the growth index is quite model dependent in the redshift space, , so observations of the structure growth around this epoch
would be very interesting. Also one may be able to rule out some dark energy
models by using the analysis from this exact solution. Thus, the analytic
solution for the growth factor provides the very useful tools for future
observations to constrain the exact values of observational quantities at any
epoch related to the growth factor in the dark energy models.Comment: 8pages, 3figures, 1Table, minor revisions to match version accepted
by PLB (add Fig1
Corruption and International Valuation: Does Virtue Pay?
Using firm-level data from 44 countries, we investigate the relation between corruption and international corporate values. Our analysis shows that firms from more corrupt countries trade at significantly lower market multiples. The effect is both economically and statistically significant. Furthermore, using a two-stage estimation procedure, we show that corruption impacts firm value primarily through lower expected future cash flows, most directly captured by firms’ profitability forecasts. Collectively, our evidence shows corruption has significant economic consequences for shareholder value.corruption; international valuation; market multiple
Hamiltonian approach to slip-stacking dynamics
Hamiltonian dynamics has been applied to study the slip-stacking dynamics.
The canonical-perturbation method is employed to obtain the second-harmonic
correction term in the slip-stacking Hamiltonian. The Hamiltonian approach
provides a clear optimal method for choosing the slip-stacking parameter and
improving stacking efficiency. The dynamics are applied specifically to the
Fermilab Booster-Recycler complex. The dynamics can also be applied to other
accelerator complexes.Comment: 10 p
Medication use by early-stage breast cancer survivors: a 1-year longitudinal study.
PurposeThe aim of this study is to characterize the patterns of medication use by early-stage breast cancer (ESBC) survivors from diagnosis to 1 year post-chemotherapy.MethodsA single-center longitudinal study was conducted with ESBC patients diagnosed between December 2011 and June 2014. Data on the medication use of individual patients were retrieved from prescription databases, supplemented by records from the National Electronic Health Records. The data covered the period from ESBC diagnosis to 1 year post-chemotherapy. Medication types were classified according to the World Health Organization's Anatomical Therapeutic Chemical classification system, and medication for chronic diseases was created by adapting a list of 20 chronic diseases provided by the U.S. Department of Human and Health Services.ResultsOf the 107 patients involved in the study (mean age 51.1 ± 8.4 years; 78.5 % Chinese), 46.7 % manifested non-cancer comorbidities, of which hypertension (24.3 %) was the most prevalent, followed by hyperlipidemia (13.1 %) and diabetes (5.6 %). Calcium channel blockers (12.1 %) and lipid-modifying agents (11.2 %) were the most common chronic medication types used before chemotherapy, and their use persisted during chemotherapy (10.3 and 11.2 %, respectively) and after chemotherapy (11.2 and 13.1 %, respectively). Hormonal therapy was the predominant post-chemotherapy medication (77.6 %). A statistically significant increase (p < 0.0001) was observed in the mean number of chronic disease medication classes prescribed to patients between the pre-chemotherapy (0.53 ± 1.04) and chemotherapy (0.62 ± 1.08) periods and between the chemotherapy and post-chemotherapy (1.63 ± 1.35) periods.ConclusionsThere is an increase in trend of chronic medication usage in breast cancer survivors after cancer treatment. This study provides important insights into the design of medication management programs tailored to this population. Future studies should incorporate a control population to improve the interpretation of study results
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