Pairing Correlations Near a Kondo-Destruction Quantum Critical Point

Motivated by the unconventional superconductivity observed in heavy-fermion metals, we investigate pairing susceptibilities near a continuous quantum phase transition of the Kondo-destruction type. We solve two-impurity Bose-Fermi Anderson models with Ising and Heisenberg forms of the interimpurity exchange interaction using continuous-time quantum Monte-Carlo and numerical renormalization-group methods. Each model exhibits a Kondo-destruction quantum critical point separating Kondo-screened and local-moment phases. For antiferromagnetic interimpurity exchange interactions, singlet pairing is found to be enhanced in the vicinity of the transition. Implications of this result for heavy-fermion superconductivity are discussed.Comment: 5 pages, 5 figures + supplementary material 2 page, 2 figures: Replaced with published versio

Handling Attrition in Longitudinal Studies: The Case for Refreshment Samples

Panel studies typically suffer from attrition, which reduces sample size and can result in biased inferences. It is impossible to know whether or not the attrition causes bias from the observed panel data alone. Refreshment samples - new, randomly sampled respondents given the questionnaire at the same time as a subsequent wave of the panel - offer information that can be used to diagnose and adjust for bias due to attrition. We review and bolster the case for the use of refreshment samples in panel studies. We include examples of both a fully Bayesian approach for analyzing the concatenated panel and refreshment data, and a multiple imputation approach for analyzing only the original panel. For the latter, we document a positive bias in the usual multiple imputation variance estimator. We present models appropriate for three waves and two refreshment samples, including nonterminal attrition. We illustrate the three-wave analysis using the 2007-2008 Associated Press-Yahoo! News Election Poll.Comment: Published in at http://dx.doi.org/10.1214/13-STS414 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Temporal trends in inequalities of the burden of HIV/AIDS across 186 countries and territories

Background The Global Burden of Disease, Injuries, and Risk Factors Study (GBD) has reported that HIV/AIDS continues to take a disproportionate toll on global health. However, the trends in global inequality of HIV/AIDS burden have remained ambiguous over the past two decades. The objectives of our study were to assess the socioeconomic inequalities, and temporal trends of HIV/AIDS across 186 countries and territories from 2000 to 2019. Methods We extracted data from the GBD 2019, and conducted a cross-national time-series analysis. Agestandardized disability-adjusted life-year (DALY) rates were used to measure the global burden of HIV/AIDS. Gross national income (GNI) per capita was used to approximate the national socioeconomic status. Linear regression analysis was conducted to investigate the relationship between age-standardized DALY rates due to HIV/AIDS and GNI per capita. The concentration curve and concentration index (CI) were generated to evaluate the cross-national socioeconomic inequality of HIV/AIDS burden. A joinpoint regression analysis was used to quantify the changes in trends in socioeconomic inequality of HIV/AIDS burden from 2000 to 2019. Results A decrease in age-standardized DALY rates for HIV/AIDS occurred in 132 (71%) of 186 countries/territories from 2000 to 2019, of which 52 (39%) countries/territories achieved a decrease in DALYs of more than 50%, and 27 (52%) of the 52 were from sub-Saharan Africa. The concentration curves of the age-standardized DALY rates of HIV/ AIDS were above the equality line from 2000 to 2019. The CI rose from −0.4625 (95% confidence interval −0.6220 to -0.2629) in 2000 to -0.4122 (95% confidence interval −0.6008 to -0.2235) in 2019. A four-phase trend of changes in the CIs of age-standardized DALY rates for HIV/AIDS was observed across 2000 to 2019, with an average increase of 0.6% (95% confidence interval 0.4 to 0.8, P<0.001). Conclusions Globally, the burden of HIV/AIDS has decreased over the past two decades, accompanied by a trend of narrowing cross-country inequalities of HIV/AIDS burden. Moreover, the burden of HIV/AIDS continues to fall primarily in low-income countries

Study the Heavy Molecular States in Quark Model with Meson Exchange Interaction

Some charmonium-like resonances such as X(3872) can be interpreted as possible $D^{(*)}D^{(*)}$ molecular states. Within the quark model, we study the structure of such molecular states and the similar $B^{(*)}B^{(*)}$ molecular states by taking into account of the light meson exchange ($\pi$, $\eta$, $\rho$, $\omega$ and $\sigma$) between two light quarks from different mesons

Factors associated with health care utilization and catastrophic health expenditure among cancer patients in China : evidence from the China health and retirement longitudinal study

Background: Cancer, the leading cause of mortality in China, is a significant burden on patients, their families, the medical system, and society at large. However, there is minimal data on health service utilization and catastrophic health expenditure (CHE) among cancer patients in China. The objective of this study was to identify factors associated with health care utilization and CHE in Chinese cancer patients. Methods: The 2018 wave of a nationally representative dataset, the China Health and Retirement Longitudinal Study, was used in our study. Of 18,968 respondents recruited for the analysis, 388 were clinically diagnosed with cancer. CHE was defined as household health expenditure that exceeded 40% of non-food household expenses. A binary logistic regression model was used to identify the risks of cancer exposure among all participants, along with the likelihood of CHE in households with cancer patients at the 40% threshold. A negative binomial regression model was used to identify determinants of health service utilization among cancer patients. Results: Contracting a family physician (incidence rate ratio IRR: 2.38, 1.18–4.77), Urban Employee Basic Medical Insurance (IRR: 4.02, 1.91–8.46, compared to the uninsured), Urban and Rural Resident Basic Medical Insurance (IRR: 3.08, 1.46–6.49, compared to the uninsured), and higher per-capita household consumption were positively associated with inpatient service utilization. Patients with a college education and above reported a greater number of outpatient visits (IRR: 5.78, 2.56–13.02) but fewer inpatient hospital days (IRR: 0.37, 0.20–0.67). Being diagnosed with a non-cancer chronic non-communicable disease was associated with an increased number of outpatient visits (IRR: 1.20, 1.10–1.31). Of the 388 participants, 50.1% of households had CHE, which was negatively correlated with a larger household size (odds ratio OR: 0.52, 0.32–0.86) and lower socioeconomic status [for quintile 5 (lowest group) OR: 0.32, 0.14–0.72]