Variable selection in robust joint mean and covariance model for longitudinal data analysis

In longitudinal data analysis, a correct specification of the within-subject covariance matrix cultivates an efficient estimation for mean regression coefficients. In this article, we consider robust variable selection method in a joint mean and covariance model. We propose a set of penalized robust generalized estimating equations to simultaneously estimate the mean regression coefficients, the generalized autoregressive coefficients, and innovation variances introduced by the modified Cholesky decomposition. The set of estimating equations select important covariate variables in both mean and covariance models together with the estimating procedure. Under some regularity conditions, we develop the oracle property of the proposed robust variable selection method. Finally, a simulation study and a detailed data analysis are carried out to assess and illustrate the small sample performance; they show that the proposed method performs favorably by combining the robustifying and penalized estimating techniques together in the joint mean and covariance model.published_or_final_versio

Interactions of a hairy vetch-corn rotation and P fertilizer on the NPK balance in an upland red soil of the Yunnan plateau

A field experiment was conducted on an infertile red soil under a hairy vetch (Vicia villosa Roth) and corn (Zea mays L.) rotation system in a highland area of Yunnan Province, China. Effects of phosphate (P) fertilization, combined with hairy vetch returned to the soil, on crop yield and soil fertility were studied, and the balances of nitrogen (N), phosphorus (P) and potassium (K) in the rotation system were estimated. As P application increased from 135 to 315 kg ha-1, the dry matter yield of hairy vetch increased by 900.6 to 1283.86 kg DM ha-1, and also promoted P absorption by hairy vetch. When compared with CK, the corn and corn straw yield increased by 16.64 and 33.48%, respectively, from the crop rotation system, while it increased by 18.36 and 34.96% and 32.58 and 66.5%, from the integrated use of green manure and P fertilizer, respectively. Simple crop rotation proceeding could improve soil N content in the 0 to 20 cm soil layer, while the combined P application improved soil P content. After corn harvest, soil Olsen-P content under the different treatments increased by 35.31 and 122.15% and 19.70 and 63.63% in the 0 to 10 and 10 to 20 cm soil layers, respectively. The optimum P fertilizer rate for the hairy vetch-corn rotation system in Yunnan Province was 135 kg P2O5 ha,sup>-1. At this P rate, the nutrient balance surpluses for N, P and K were 84.9, 18.9 and 26.4%, respectively.Keywords: Rotation system, crop yield, green manure, NPK balance, P fertilizer, soil physical and chemical properties

Role of Dielectric Drag in Polaron Mobility in Lead Halide Perovskites

This is the author accepted manuscript. The final version is available from American Chemical Society via the DOI in this record.Hybrid organic-inorganic lead halide perovskites (HOIPs) have attracted much attention because of their remarkable carrier lifetimes and diffusion lengths. These properties have been attributed to the efficient screening of charge carriers via polaron formation in the highly polar and dynamic environment. Polaron formation explains, at least in part, the moderate charge carrier mobility, but the calculated mobilities are somewhat higher than experimental values. Here we discuss a factor that has been previously overlooked and can potentially account for the discrapency: the effect of dielectric drag. While optical phonon modes of the lead halide sublattice are mainly responsible for polaron formation, slower orientational relaxation of surrounding dipoles adds a dielectric drag to the moving charge. We discuss the role of this dielectric drag based on the measured dielectric function in the gigahertz to terahertz frequency range and how we can understand the unique carrier physics in HOIPs in view of its crystal-liquid duality.We thank Prof. X. Roy, Dr. Johannes Hunger, Dr. Jarvist Frost, Prof. Shaul Mukamel, Prof. Casey Hynes, and Prof. Louis Brus for insightful discussions. X.Y.Z. thanks Profs. Song Jin, Vitaly Podzorov, and Filippo De Angelis for fruitful collaborations and his group, particularly Dr. Daniel Niesner, Dr. Xiaoxi Wu, Dr. Haiming Zhu, Dr. M. Tuan Trinh, Mr. Jue Wang, and Ms. Prakriti Joshi, for the experimental work which precipitated the ideas presented here. X.Y.Z. acknowledges U.S. Department of Energy, Office of Science - Basic Energy Sciences, Grant ER46980 for support during the writing of this Perspective. K.M. acknowledges JSPS for financial support

Highly reproducible SERS substrate based on polarization-free Ag nanoparticles decorated SiO2/Si core-shell nanowires array

SiO2/Si core-shell nanowires array coated with gap-rich silver nanoparticles were demonstrated as a highly reproducible surface-enhanced Raman scattering (SERS) substrate. SERS detection of a relative standard deviation of 8% for 10−4 M R6G with a spot size of ∼2 μm and 900 spots over an area of 150 × 150 μm2 was reported. The high reproducibility is ascribed to the polarization-independent electrical field distribution among three-dimensional nanowire structure with an optimized thickness of SiO2 shell layer.published_or_final_versio

Histamine increases neuronal excitability and sensitivity of the lateral vestibular nucleus and promotes motor behaviors via HCN channel coupled to H2 receptor

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Effect of Lactobacillus acidophilus, Oenococcus oeni, and Lactobacillus brevis on Composition of Bog Bilberry Juice

This study investigated the impact of Lactobacillus acidophilus NCFM, Oenococcus oeni Viniflora((R)) Oenos and Lactobacillus brevis CICC 6239 on bog bilberry juice with a considerably low pH and rich in anthocyanins content. Moreover, the effects of the strains on the composition of phenolic compounds, amino acids, ammonium ion, biogenic amines, reduced sugars, organic acids, and color parameters of the juice were studied. All three bacteria consumed sugars and amino acids but exhibited different growth patterns. Lactic acid was detected only in L. acidophilus inoculated juice. The content of the phenolic compounds, especially anthocyanins, decreased in juice after inoculation. The CIELa*b* analysis indicated that the juice inoculated with L. acidophilus and O. oeni showed a decrease on a* and b* (less red and yellow) but an increase on L (more lightness), whereas the color attributes of L. brevis inoculated juice did not significantly change. Based on this study, L. brevis showed the most optimal performance in the juice due to its better adaptability and fewer effects on the appearance of juice. This study provided a useful reference on the metabolism of lactic acid bacteria in low pH juice and the evolution of primary and secondary nutrients in juice after inoculated with lactic acid bacteria

Lumbar spinal stenosis: an update on the epidemiology, diagnosis and treatment

Lumbar spinal stenosis (LSS) is a common spinal disorder in the older population, and the clinical syndrome consisting of pain in the buttock or lower extremity, with or without low back pain and corresponding imaging findings of narrowing of spaces around neural and vascular elements in the lumbar spine. The diagnosis depends on history, symptoms, physical examination, radiographies. Varieties of non-operative and operative options are available for LSS patients. In this article, an update on the epidemiology, diagnosis and treatment of LSS was reviewed.published_or_final_versio