Information-Based Trading and the Bid-Ask Spread

We analyze the equilibrium spread when the transaction size of informed traders is elastic in the value of private information (α). We show that the pooling equilibrium is likely to be inefficient when trade size is sensitive to α and the inefficient equilibrium can occur before the market breaks down. The pooling equilibrium spread does not monotonically increase with α, although it increases with the elasticity of informed trades to α. The upper bound of the elasticity of informed trades for the market to remain open for the active specialist is higher than the corresponding value for the passive specialist when the specialist has enough leverage over brokers

Signatures of Electronic Nematic Phase at Isotropic-Nematic Phase Transition

The electronic nematic phase occurs when the point-group symmetry of the lattice structure is broken, due to electron-electron interactions. We study a model for the nematic phase on a square lattice with emphasis on the phase transition between isotropic and nematic phases within mean field theory. We find the transition to be first order, with dramatic changes in the Fermi surface topology accompanying the transition. Furthermore, we study the conductivity tensor and Hall constant as probes of the nematic phase and its transition. The relevance of our findings to Hall resistivity experiments in the high-$T_c$ cuprates is discussed.Comment: 5 pages, 3 figure

The Dynamics of Quote Adjustments

Liquidity providers on the NYSE make faster quote adjustments towards equilibrium spreads and depths than they do on NASDAQ. Liquidity providers in both markets make faster spread and depth adjustments for stocks with more frequent trading, greater return volatility, higher prices, smaller market capitalizations, and smaller trade sizes. We find that stocks with greater information-based trading and in more competitive trading environments exhibit faster quote adjustments. The speed of quote adjustment is faster after decimalization in both markets. These results are robust and not driven by differences in stock attributes between the two markets or time periods. Overall, our results indicate that stock attributes, market structure, and tick size exert a significant impact on the speed of quote adjustment

Impact Of Changes In Strategic Investments On Shareholder Returns: The Role Of Growth Opportunities

We argue that a firm’s growth opportunity may provide us with guidelines on whether increases or decreases in capital investments may contribute to that firm’s returns to shareholders.  We find consistent empirical support for “good” managerial decisions.  That is, we find that increases in capital investments by firms with growth opportunities enhance their returns to shareholders.  The results indicate that decreases in strategic investments increase the returns to shareholders of those firms lacking in growth opportunities.  The findings, however, are not consonantally significant for “bad” managerial investment decisions - - decreases in investments by firms with growth opportunities or increases in investments by firms lacking in growth opportunities

Empirical Regularities in the Market for Real Estate Research Output

This study examines whether any regularity exists in the publication pattern among real estate researchers. Identifying an empirical regularity in research output is useful since it helps assess both the likelihood of multiple publications and the degree of author concentration among different journals. The empirical results reveal that a strong bibliometric regularity exists in the real estate literature: the number of authors publishing n papers is approximately 1/n^c of those publishing one paper. It is shown that the real estate literature conforms very well to the model with c=2.446 if data are taken from a large collection of journals. When applied to individual journals, the result shows that values of c range from 2.321 to 3.835.

Realization of giant magnetoelectricity in helimagnets

We show that low field magnetoelectric (ME) properties of helimagnets Ba0.5Sr1.5Zn2(Fe1-xAlx)12O22 can be efficiently tailored by Al-substitution level. As x increases, the critical magnetic field for switching electric polarization is systematically reduced from ~1 T down to ~1 mT, and the ME susceptibility is greatly enhanced to reach a giant value of 2.0 x 10^4 ps/m at an optimum x = 0.08. We find that control of nontrivial orbital moment in the octahedral Fe sites through the Al-substitution is crucial for fine tuning of magnetic anisotropy and obtaining the conspicuously improved ME characteristics

Raman Spectra of Triplet Superconductor in Sr2_2RuO4_4

We study the Raman spectra of spin-triplet superconductors in Sr$_2$RuO$_4$. The p-wave and f-wave symmetries are considered. We show that there is the clapping mode with frequency of $\sqrt{2} \Delta(T)$ and $1.02 \Delta(T)$ for p-wave and f-wave superconductors, respectively. This mode is visible as a huge resonance in the B1g and B2g modes of Raman spectra. We discuss the details of the Raman spectra in these superconducting states.Comment: 5 pages, 3 figure

Effect of Ring Exchange on Orbital Antiferromagnet

We study the effect of four-particle ring exchange process on orbital antiferromagnetic state that occurs in some correlated electron systems in two dimensions. The primary question is whether the ring exchange process enhances or suppresses the orbital antiferromagnetic ordering. Using the fact that the orbital antiferromagnetic state arises in the large-N limit of the SU(N) generalization of the t-J model, we consider the large-N limit of the t-J-$K$ model where $K$ represents the four-particle ring exchange term. The phase diagrams in the large-N mean field theory are obtained for the half-filling and finite hole concentrations at zero temperature. It is found that the ring exchange in general favors dimerized states or the inhomogeneous orbital antiferromagnetic state, and suppresses the homogeneous orbital antiferromagnetic state. We compare our results with other related models of strongly correlated systems with ring exchange processes.Comment: 14 pages, 17 figure

Prescribing patterns of low doses of antipsychotic medications in older Asian patients with schizophrenia, 2001-2009

Background: This study examined the use of low doses of antipsychotic medications (300mg/day CPZeq or less) in older Asian patients with schizophrenia and its demographic and clinical correlates. Methods: Information on hospitalized patients with schizophrenia, aged 55 years or older, was extracted from the database of the Research on Asian Psychotropic Prescription Patterns (REAP) study (2001-2009). Data on 1,452 patients in eight Asian countries and territories including China, Hong Kong, Japan, Korea, Singapore, Taiwan, India, and Malaysia were analyzed. Sociodemographic and clinical characteristics and antipsychotic prescriptions were recorded using a standardized protocol and data collection procedure. Results: The prescription frequency for low doses of antipsychotic medications was 40.9% in the pooled sample. Multiple logistic regression analysis of the whole sample showed that patients on low doses of antipsychotic medications were more likely to be female, have an older age, a shorter length of illness, and less positive symptoms. Of patients in the six countries and territories that participated in all the surveys between 2001 and 2009, those in Japan were less likely to receive low doses of antipsychotics. Conclusion: Low doses of antipsychotic medications were only applied in less than half of older Asian patients with schizophreni

Gremlin-1 Induces BMP-Independent Tumor Cell Proliferation, Migration, and Invasion

Gremlin-1, a bone morphogenetic protein (BMP) antagonist, is overexpressed in various cancerous tissues but its role in carcinogenesis has not been established. Here, we report that gremlin-1 binds various cancer cell lines and this interaction is inhibited by our newly developed gremlin-1 antibody, GRE1. Gremlin-1 binding to cancer cells was unaffected by the presence of BMP-2, BMP-4, and BMP-7. In addition, the binding was independent of vascular endothelial growth factor receptor-2 (VEGFR2) expression on the cell surface. Addition of gremlin-1 to A549 cells induced a fibroblast-like morphology and decreased E-cadherin expression. In a scratch wound healing assay, A549 cells incubated with gremlin-1 or transfected with gremlin-1 showed increased migration, which was inhibited in the presence of the GRE1 antibody. Gremlin-1 transfected A549 cells also exhibited increased invasiveness as well as an increased growth rate. These effects were also inhibited by the addition of the GRE1 antibody. In conclusion, this study demonstrates that gremlin-1 directly interacts with cancer cells in a BMP- and VEGFR2-independent manner and can induce cell migration, invasion, and proliferation