Ab initio calculation of spin fluctuation spectra using time dependent density functional perturbation theory, planewaves, and pseudopotentials

We present an implementation of time-dependent density functional perturbation theory for spin fluctuations, based on planewaves and pseudopotentials. We compute the dynamic spin susceptibility self-consistently by solving the time-dependent Sternheimer equation, within the adiabatic local density approximation to the exchange and correlation kernel. We demonstrate our implementation by calculating the spin susceptibility of representative elemental transition metals, namely bcc Fe, fcc Ni and bcc Cr. The calculated magnon dispersion relations of Fe and Ni are in agreement with previous work. The calculated spin susceptibility of Cr exhibits a soft-paramagnon instability, indicating the tendency of the Cr spins to condense in a incommensurate spin density wave phase, in agreement with experiment

Fear of the Unknown: Familiarity and Economic Decisions

Evidence indicates that people fear change and the unknown. We offer a model of familiarity bias in which individuals focus on adverse scenarios in evaluating defections from the status quo. The model explains the endowment effect, portfolio underdiversification, home and local biases. Equilibrium stock prices reflect an unfamiliarity premium. In an international setting, our model implies that the absolute pricing error of the standard CAPM is positively correlated with the amount of home bias. It also predicts that a modified CAPM holds wherein the market portfolio is replaced with a portfolio of the stock holdings of investors not subject to familiarity bias.

Inventory Information

In a market with symmetric information about fundamentals, can information-based trade still arise? Consider bond and FX markets, where private information about nominal cash flows is generally absent, but participants are convinced that superior information exists. We analyze a class of asymmetric information - inventory information - that is unrelated to fundamentals, but still forecasts future price (by forecasting future discount factors). Empirical work based on the analysis shows that inventory information in FX does indeed forecast discount factors, and does so over both short and long horizons. The immediate price impact of shocks to inventory information is large, roughly 50 percent of that from public information shocks (the latter being the whole story under symmetric information). Within about 30 minutes the transitory effect dies out, and prices reflect a permanent effect from inventory information that ranges between 15 and 30 percent of that from public information.

Utilisation of Health Services in Poor Rural China: An Analysis Using a Logistic Regression Model

The aim of this article is to explore the determinants of utilisation of health services in poor rural areas of China. Such a systematic identification of the factors which influence the demand for, and use of, health care services may provide information that policy makers can use to target services to those in greatest need and assist in the design of risk-sharing schemes to protect the poor from the adverse impact of health expenditures

H⁺ Permeation and pH Regulation at a Mammalian Serotonin Transporter

The rat serotonin transporter expressed in Xenopusoocytes displays an inward current in the absence of 5-HT when external pH is lowered to 6.5 or below. The new current differs from the leakage current described previously in two ways. (1) It is ∼10-fold larger at pH 5 than the leakage current at pH 7.5 and reaches 1000 H⁺/sec per transporter at extremes of voltage and pH with no signs of saturation. (2) It is selective for H⁺ by reversal potential measurements. Similar H⁺-induced currents are also observed in several other ion-coupled transporters, including the GABA transporter, the dopamine transporter, and the Na⁺/glucose transporter. The high conductance and high selectivity of the H⁺-induced current suggest that protons may be conducted via a hydrogen-bonded chain (a “proton-wire mechanism”) formed at least partially by side chains within the transporter. In addition, pH affects other conducting states of rat serotonin transporter. Acidic pH potentiates the 5-HT-induced, transport-associated current and inhibits the hyperpolarization-activated transient current. The dose–response relationships for these two effects suggest that two H⁺ binding sites, with pK_a values close to 5.1 and close to 6.3, govern the potentiation of the 5-HT-induced current and the inhibition of the transient current, respectively. These results are important for developing structure-function models that explain permeation properties of neurotransmitter transporters

Oleanane triterpenoid CDDO-Me induces apoptosis in multidrug resistant osteosarcoma cells through inhibition of Stat3 pathway.

BackgroundThe activation of signal transducer and activator of transcription 3 (Stat3) pathway correlates with tumor growth, survival, drug resistance and poor prognosis in osteosarcoma. To explore the potential therapeutic values of this pathway, we assessed both the expression and the activation of Stat3 pathway in several pairs of multidrug resistant (MDR) osteosarcoma cell lines, and tissues. To explore the potential therapeutic values of this pathway, we analyzed the ability of the synthetic oleanane triterpenoid, C-28 methyl ester of 2-cyano-3,12-dioxoolen-1,9-dien-28-oic acid (CDDO-Me), to inhibit Stat3 expression and activation as well as its effects on doxorubicin sensitivity in osteosarcoma cells.MethodsExpression of Stat3, phosphorylated Stat3 (pStat3) and Stat3 targeted proteins, including Bcl-XL, Survivin and MCL-1 were determined in drug sensitive and MDR osteosarcoma cell lines and tissues by Western blot analysis. The effect of CDDO-Me on osteosarcoma cell growth was evaluated by MTT and apoptosis by PARP cleavage assay and caspase-3/7 activity.ResultsStat3 pathway was activated in osteosarcoma tissues and in MDR cell lines. CDDO-Me inhibited growth and induced apoptosis in osteosarcoma cell lines. Treatment with CDDO-Me significantly decreased the level of nuclear translocation and phosphorylation of Stat3. The inhibition of Stat3 pathway correlated with the suppression of the anti-apoptotic Stat3 targeted genes Bcl-XL, survivin, and MCL-1. Furthermore, CDDO-Me increased the cytotoxic effects of doxorubicin in the MDR osteosarcoma cell lines.ConclusionsStat3 pathway is overexpressed in MDR osteosarcoma cells. CDDO-Me significantly inhibited Stat3 phosphorylation, Stat3 nuclear translocation and induced apoptosis in osteosarcoma. This study provides the framework for the clinical evaluation of CDDO-Me, either as monotherapy or perhaps even more effectively in combination with doxorubicin to treat osteosarcoma and overcome drug resistance

H⁺ Permeation and pH Regulation at a Mammalian Serotonin Transporter

The rat serotonin transporter expressed in Xenopusoocytes displays an inward current in the absence of 5-HT when external pH is lowered to 6.5 or below. The new current differs from the leakage current described previously in two ways. (1) It is ∼10-fold larger at pH 5 than the leakage current at pH 7.5 and reaches 1000 H⁺/sec per transporter at extremes of voltage and pH with no signs of saturation. (2) It is selective for H⁺ by reversal potential measurements. Similar H⁺-induced currents are also observed in several other ion-coupled transporters, including the GABA transporter, the dopamine transporter, and the Na⁺/glucose transporter. The high conductance and high selectivity of the H⁺-induced current suggest that protons may be conducted via a hydrogen-bonded chain (a “proton-wire mechanism”) formed at least partially by side chains within the transporter. In addition, pH affects other conducting states of rat serotonin transporter. Acidic pH potentiates the 5-HT-induced, transport-associated current and inhibits the hyperpolarization-activated transient current. The dose–response relationships for these two effects suggest that two H⁺ binding sites, with pK_a values close to 5.1 and close to 6.3, govern the potentiation of the 5-HT-induced current and the inhibition of the transient current, respectively. These results are important for developing structure-function models that explain permeation properties of neurotransmitter transporters

Unified Field Theory and Topology of Nuclei

Abstract This paper proposes that a nucleus has a lattice configuration. A nucleus can not be seen visually. The configuration of a nucleus is studied in theoretical models, such as lattice, NCFC, and water drop. There are a few theories study many body interactions in a nucleus, such as Ab initio calculation, BCS formalism, and SEMF. However, the precise structure of an isotope is not known. According to Unified Field Theory (UFT), a proton has the shape of an octahedron. Since the strong forces are along the axes of the octahedron of protons and neutron, the structure of ground state isotopes of any given element can be logically induced. Furthermore, only two of three axes of the octahedron nucleus possess interactive forces. Therefore, any nuclear structure has one layer only. Our results demonstrate that there is a configuration for any isotope. Mass, stability and configuration of an isotope are related. We anticipate our essay to be a starting point of new method that provides precise configuration for each isotope, theoretical mass calculation for an unknown isotope, and nuclear characteristics/stability analysis for a given configuration. For example, the best symmetrical lattice of an isotope can be selected from all possible lattices. The selected lattice for the isotope can decide the stability of the isotope