Thank God That Regressing Y on X is Not the Same as Regressing X on Y: Direct and Indirect Residual Augmentations

What does regressing Y on X versus regressing X on Y have to do with MCMC? It turns out that many strategies for speeding up data-augmentation type algorithms can be understood as fostering independence or “de-correlation” between a regression function and the corresponding residual, thereby reducing or even eliminating dependence among MCMC iterates. There are two general classes of algorithms, those corresponding to regressing parameters on augmented data/auxiliary variables and those that operate the other way around. The interweaving strategy (Yu and Meng, 2011, JCGS) provides a general recipe to automatically take advantage of both, and it is the existence of two different types of residuals that makes the interweaving strategy seemingly magical in some cases and promising in general. The concept of residuals—which depends on actual data—also highlights the potential for substantial improvements when data augmentation schemes are allowed to depend on the observed data. At the same time, there is an intriguing phase transition type of phenomenon regarding choosing (partially) residual augmentation schemes, reminding us once more of the prevailing issue of trade-off between robustness and efficiency. This article reports on these latest theoretical investigations (using a class of normal/independence models) and empirical findings (using a posterior sampling for a Probit regression) in the search for effective residual augmentations—and ultimately more MCMC algorithms—that meet the 3-S criterion: simple, stable, and speedy.Statistic

Coronal lines and the importance of deep core-valence correlation in Ag-like ions

We report on large-scale and critically evaluated {\em ab initio} MCDHF calculations of the wavelength of the "coronal", M1 transition $4f\ ^2\mathrm{F}_{5/2}^o-^2\mathrm{F}_{7/2}^o$in Ag-like ions. The transition between these two fine structure levels, which makes up the ground term for$Z \ge 62$in the isoelectronic sequence, has recently been observed in Yb$^{23+}$and W$^{27+}$, where the latter could be of great importance for fusion plasma diagnostics. We present recommended values for all members of the sequence between$Z = 50$and$94$, which are supported by excellent agreement with values from recent experiments. The importance of including core-valence correlation with the$n=3$ shell in the theoretical model is emphasized. The results show close to spectroscopic accuracy for these forbidden lines.Comment: 10 pages, 5 figures, 3 table

La representación de la comunicación social a través de la noción de "armonía"

Desde las épocas más remotas, el concepto de "armonía" ocupa un lugar central y determinante en la cultura china. Pero no es un concepto extático sino todo lo contrario: un término siempre en construcción al que a lo largo de la historia de la civilización china se le han agregado numerosos elementos. En un momento determinado, por presiones políticas se "realza exclusivamente el Confucianismo suprimiendo otras corrientes ideológicas"1. Este cambio se realizó en la era del emperador Wu de la dinastía Han (147-87), en donde la noción de 'armonía', que representa la arteria la dicha ideología, alcanzó una prosperidad sin precedentes. Desde ese momento, y a lo largo de dos mil años, la "armonía" se convirtió en el eje en la vida cotidiana, la sociedad y la cultura de China hasta el momento actual. A continuación, vamos a aclarar este concepto del que tenemos en cuenta su extraordinaria complejidad y riqueza de significados, explicándolo en cinco partes: el estudio del propio término "armonía", su inclusión en la tradición religiosa china, las formas de representación que adopta en la cultura oriental, su inserción y su presencia en la vida cotidiana y una reflexión acerca de la actual "Sociedad Armoniosa"

The effect of an external magnetic field on the determination of E1M1 two-photon decay rates in Be-like ions

In this work we report on ab initio theoretical results for the magnetic field induced 2s2p ^3P_0 - 2s^2 ^1S_0 E1 transition for ions in the beryllium isoelectronic sequence between Z=5 and 92. It has been proposed that the rate of the E1M1 two-photon transition 2s2p ^3P_0 - 2s^2 ^1S_0 can be extracted from the lifetime of the ^3P_0 state in Be-like ions with zero nuclear spin by employing resonant recombination in a storage-ring. This experimental approach involves a perturbing external magnetic field. The effect of this field needs to be evaluated in order to properly extract the two-photon rate from the measured decay curves. The magnetic field induced transition rates are carefully evaluated and it is shown that, with a typical storage-ring field strength, it is dominant or of the same order as the E1M1 rate for low- and mid-Z ions. Results for several field strengths and ions are presented and we also give a simple Z-dependent formula for the rate. We estimate the uncertainties of our model to be within 5% for low- and mid-Z ions, and slightly larger for more highly charged ions. Furthermore we evaluate the importance of including both perturber states, ^3P_1 and ^1P_1, and it is shown that excluding the influence of the ^1P_1 perturber overestimates the rate by up to 26% for the mid-Z ions.Comment: 21 pages, 5 figure

Factors influencing voluntary premarital medical examination in Zhejiang province, China: a culturally-tailored health behavioral model analysis

BACKGROUND: Premarital medical examination (PME) compliance rate has dropped drastically since it became voluntary in China in 2003. This study aimed to establish a prediction model to be a theoretic framework for analyzing factors affecting PME compliance in Zhejiang province, China. METHODS: A culturally-tailored health behavioral model combining the Health Behavioral Model (HBM) and the Theory of Reasoned Action (TRA) was established to analyze the data from a cross-sectional questionnaire survey (n = 2,572) using the intercept method at the county marriage registration office in 12 counties from Zhejiang in 2010. Participants were grouped by high (n = 1,795) and low (n = 777) social desirability responding tendency (SDRT) by Marlowe-Crowne Social Desirability Scale (MCSDS). A structural equation modeling (SEM) was conducted to evaluate behavioral determinants for their influences on PME compliance in both high and low SDRT groups. RESULTS: 69.8% of the participants had high SDRT and tended to overly report benefits and underreport barriers, which may affect prediction accuracy on PME participation. In the low SDRT group, the prediction model showed the most influencing factor on PME compliance was behavioral intention, with standardized structural coefficients (SSCs) being 0.75 (P < 0.01), and the intention was positively determined by individual’s attitude toward PME (SSCs = 0.48, P < 0.01) and subjective norms (SSCs = 0.22, P < 0.01) and negatively determined by perceived threat (SSCs = -0.08, P = 0.028). Attitudes and subjective norms were more crucial predictors for PME compliance than perceived threat (SSCs = 0.36, 0.269, and -0.06, respectively). County environmental factors played a role in PME compliance while less influential than behavioral determinates (16% vs. 84% in across factor variance partition coefficient). CONCLUSIONS: PME compliance might be influenced by demographic, behavioral, and social environmental factors. The verified prediction model was tested to be an effective theoretic framework for the prediction of factors affecting voluntary PME compliance. It also should be noted that internationally available behavioral theories and models need to be culturally tailored to adapt to particular populations. This study has provided new insights for establishing a theoretical model to understand health behaviors in China

Evaluating the effect of kidney volume on decline in renal function using the generalized propensity score

Autosomal-dominant polycystic kidney disease (ADPKD) is characterized by gradual renal enlargement and cyst growth prior to the loss of renal function. The Consortium for Radiologic Imaging Studies in Polycystic Kidney Disease (CRISP) is a longitudinal observational study ADPKD individuals using high-resolution magnetic resonance (MR) imaging to determine if a change in renal and cyst volumes can be detected over a short period of time, and if they correlate with a decline in renal function early in the disease. The aim of this study was to determine if height-adjusted total kidney volume (htTKV) had a causal effect on renal decline in the CRISP cohort by using a method for causal inference, namely the generalized propensity score (GPS) method, which is a generalization of the more common propensity score methods (applicable to binary treatments or exposures) for continuous data. Results provide further evidence that baseline htTKV may have a causal effect on subsequent renal function (measured at least a decade later). The study did however have limitations, as we could only consider limited factors available at birth to construct the GPS (and thus preserve temporal associations). This study has a high degree of public health significance given the high incidence and cost of chronic kidney disease (CKD) and end stage renal disease (ESRD). CKD is identified as a major public health concern requiring intervention, as nearly 20 million people are estimated to have CKD. ESRD also introduces a significant burden on patient, health care, and societal costs. Finding biomarkers that identify cases earlier are critical to reducing the disease burden