Surface-mode microcavity

Optical microcavities based on zero-group-velocity surface modes in photonic crystal slabs are studied. It is shown that high quality factors can be easily obtained for such microcavities in photonic crystal slabs. With increasing of the cavity length, the quality factor is gradually enhanced and the resonant frequency converges to that of the zero-group-velocity surface mode in the photonic crystal. The number of the resonant modes with high quality factors is mainly determined by the number of surface modes with zero-group velocity.Comment: 11 pages, 4 figure

Three-dimensional structure of human serum albumin

The binding locations to human serum albumin (HSA) of several drug molecules were determined at low resolution using crystallographic methods. The principal binding sites are located within subdomains IIA and IIIA. Preliminary studies suggest that an approach to increasing the in vivo efficacy of drugs which are rendered less effective or ineffective by virtue of their interaction with HSA, would be the use of competitive displacement in drug therapies and/or the development of a general inhibitor to the site within subdomain IIIA. These findings also suggest that the facilitated transfer of various ligands across organ/circulatory interfaces such as liver, kidney, and brain may be associated with binding to the IIIA subdomain

Exploring the Relationship between Student Involvement and First-to-second Year Retention at Four-year Postsecondary Institutions

Increasing students’ involvement on campus is one of the best practices to increase college student retention. Using data from the Education Longitudinal Study of 2002, this study investigated the relationships between first-to-second fall retention and student involvement indicators. Logistic regression analysis was employed to explore the relationships. The sample included 6,283 first-time, first-year undergraduate students who were enrolled in public or not-for-profit private four-year postsecondary institutions across the country in the fall of 2004. Results show that student-advisor interaction, student-faculty interaction, extracurricular activities participation, and library utilization were positively associated with first-to-second fall retention. Recommendations for future research and implications for practitioners are discussed

Comparing the World Health Organization-versus China-recommended protocol for first-trimester medical abortion: a retrospective analysis

OBJECTIVE: To compare the effectiveness, in terms of complete abortion, of the World Health Organization (WHO)- and the China-recommended protocol for first-trimester medical abortion. METHODS: A retrospective analysis of clinical data from women presenting for first trimester medical abortion between January 2009 and August 2010 at reproductive health clinics in Qingdao, Xi'an, Nanjing, Nanning, and Zhengzhou was conducted. One clinic in Qingdao administered the WHO-recommended protocol (200 mg mifepristone orally followed by 0.8 mg misoprostol buccally 36-48 hours later). Four clinics in the other locations provided the China-recommended procedure (Day 1: 50 mg of mifepristone in the morning, 25 mg in the afternoon; Day 2: 50 mg of mifepristone in the morning, 25 mg in the afternoon; Day 3: 0.6 mg oral misoprostol). Data on reproductive and demographic characteristics were extracted from clinic records, and complete termination was determined on day 14 (post-mifepristone administration). RESULTS: A total of 337 women underwent early medical abortion (167 WHO- and 170 China-recommended procedures). Complete abortion was significantly higher among women who had the WHO protocol than those who received the China protocol (91.0% vs 77.7%, respectively; P < 0.001). Women using the China-recommended protocol were three times more likely to require an additional dose of misoprostol than women using the WHO protocol (21.8% vs 7.8%, respectively; P < 0.001), and had significantly more bleeding on the day of misoprostol administration (12.5 mL vs 18.5 mL; P < 0.001). CONCLUSION: This clinical audit provides preliminary evidence suggesting the WHO-recommended protocol may be more effective than the China-recommended protocol for early medical abortion. A larger scale study is necessary to compare the methods' effectiveness and acceptability

Exact Numerical Solution of the BCS Pairing Problem

We propose a new simulation computational method to solve the reduced BCS Hamiltonian based on spin analogy and submatrix diagonalization. Then we further apply this method to solve superconducting energy gap and the results are well consistent with those obtained by Bogoliubov transformation method. The exponential problem of 2^{N}-dimension matrix is reduced to the polynomial problem of N-dimension matrix. It is essential to validate this method on a real quantumComment: 7 pages, 3 figure

Dynamical Self-assembly during Colloidal Droplet Evaporation Studied by in situ Small Angle X-ray Scattering

The nucleation and growth kinetics of highly ordered nanocrystal superlattices during the evaporation of nanocrystal colloidal droplets was elucidated by in situ time resolved small-angle x-ray scattering. We demonstrated for the first time that evaporation kinetics can affect the dimensionality of the superlattices. The formation of two-dimensional nanocrystal superlattices at the liquid-air interface of the droplet has an exponential growth kinetics that originates from interface "crushing".Comment: 4 pages, 4 figure

Phase-sensitive Manipulations of Squeezed Vacuum Field in an Optical Parametric Amplifier inside an Optical Cavity

Squeezed vacuum field can be amplified or deamplified when it is injected, as the signal beam, into a phase-sensitive optical parametric amplifier (OPA) inside an optical cavity. The spectral features of the reflected quantized signal field are controlled by the relative phase between the injected squeezed vacuum field and the pump field for the OPA. The experimental results demonstrate coherent phenomena of OPA in the quantum regime, and show phase-sensitive manipulations of quantum fluctuations for quantum information processing.Comment: 4 pages, 3 figures, appear in Phys. Rev. Let

Evidence of Two-Center Interference in High-Order Harmonic Generation from CO₂

Two recent pump-probe experiments on the high-order harmonic generation (HHG) from partially aligned CO₂ molecules have shown that the HHG yields versus the ionization rates as functions of the pump-probe delay time exhibit inverted modulation. The inversion has been attributed to the quantum interference in the recombination process from the two oxygen centers. Using the Lewenstein model to calculate HHG from fixed CO₂ molecules and taking into account the partial alignment of the molecules versus the time delay, we interpret that the inversion is due to the degree of overlap between the partially aligned molecules and the angular dependence of the HHG yield. We also note that the harmonic order where inversion occurs may change with probe laser intensity due to the depletion of the ground state

Comparing Statistical Methods for Constructing Large Scale Gene Networks

The gene regulatory network (GRN) reveals the regulatory relationships among genes and can provide a systematic understanding of molecular mechanisms underlying biological processes. The importance of computer simulations in understanding cellular processes is now widely accepted; a variety of algorithms have been developed to study these biological networks. The goal of this study is to provide a comprehensive evaluation and a practical guide to aid in choosing statistical methods for constructing large scale GRNs. Using both simulation studies and a real application in E. coli data, we compare different methods in terms of sensitivity and specificity in identifying the true connections and the hub genes, the ease of use, and computational speed. Our results show that these algorithms performed reasonably well, and each method has its own advantages: (1) GeneNet, WGCNA (Weighted Correlation Network Analysis), and ARACNE (Algorithm for the Reconstruction of Accurate Cellular Networks) performed well in constructing the global network structure; (2) GeneNet and SPACE (Sparse PArtial Correlation Estimation) performed well in identifying a few connections with high specificity

Effects of animal’s rumen juice on seed germination of Vicia angustifolia with different seed size

To help understand the effects of grazing on seed germination characteristics of Vicia angustifolia L., we conducted a laboratory germination experiment of V. angustifolia L., which is a main companion species of Leguminosae family in alpine grassland of the Qinghai-Tibetan Plateau, using Yak and Tibetan sheep rumen juices along three seed size categories. Results show that Yak and Tibetan sheep rumen juices significantly restrained germination of seeds for three size categories, decreased seed germination percentage, germination index and prolonged first and mean germination times. Meanwhile, the medium-size seeds presented the maximum geminated percentage, and the larger seeds germinated better than the smaller seeds. Additionally, there were significant interaction effects between rumen juice and seed size on seed germination of V. angustifolia. Our results suggest that grazing pressure of animal feed present have significant negatively effects on seed germination for V. angustifolia with different seed size in alpine area of the Qinghai-Tibetan Plateau.Key words: Vicia angustifolia, rumen juice, seed mass, germination, herbivory