The Connection Between Pulsation, Mass Loss and Circumstellar Shells in Classical Cepheids

Recent observations of Cepheids using infrared interferometry and Spitzer photometry have detected the presence of circumstellar envelopes (CSE) of dust and it has been hypothesized that the CSE's are due to dust forming in a Cepheid wind. Here we use a modified Castor, Abbott & Klein formalism to produce a Cepheid wind, and this is used to estimate the contribution of mass loss to the Cepheid mass discrepancy Furthermore, we test the OGLE-III Classical Cepheids using the IR fluxes from the SAGE survey to determine if Large Magellanic Cloud Cepheids have CSE's. It is found that IR excess is a common phenomenon for LMC Cepheids and that the resulting mass-loss rates can explain at least a fraction of the Cepheid mass discrepancy, depending on the assumed dust-to-gas ratio in the wind.Comment: 5 pages, 3 figures, proceeding for "Stellar Pulsation: Challenges for Theory and Observation", Santa Fe 200

Some Aspects of Non-Darcy Behavior of Gas Flow In Wood

A study was undertaken to determine if the Klinkenberg equation for gas flow through porous media could be applied to a wide variety of wood species. When the results proved negative, a second study was initiated to determine if the cause of the nonconformities could be traced to turbulence. The combined experiments indicated that neither molecular slippage, as described by the Klinkenberg equation, nor turbulence can adequately explain the reduction in apparent permeability with increasing mean pressure

Microscopic Theory of Rashba Interaction in Magnetic Metal

Theory of Rashba spin-orbit coupling in magnetic metals is worked out from microscopic Hamiltonian describing d-orbitals. When structural inversion symmetry is broken, electron hopping between $d$-orbitals generates chiral ordering of orbital angular momentum, which combines with atomic spin-orbit coupling to result in the Rashba interaction. Rashba parameter characterizing the interaction is band-specific, even reversing its sign from band to band. Large enhancement of the Rashba parameter found in recent experiments is attributed to the orbital mixing of 3d magnetic atoms with non-magnetic heavy elements as we demonstrate by first-principles and tight-binding calculations.Comment: 5 pages, 2 figure

Surface Modification Effects on CNTs Adsorption of Methylene Blue and Phenol

This study compares the adsorption capacity of modified CNTs using acid and heat treatment. The CNTs were synthesized from acetone and ethanol as carbon sources, using floating catalyst chemical vapor deposition (FC-CVD) method. energy-dispersive X-ray spectroscopy (EDX) and Boehm method revealed the existence of oxygen functional group on the surface of CNTs. Heat modification increases the adsorption capacity of as-synthesized CNTs for methylene blue (MB) and phenol by approximately 76% and 50%, respectively. However, acid modification decreases the adsorption capacity. The equilibrium adsorption data fitted the Redlich-Peterson isotherm. For the adsorption kinetic study, the experimental data obeyed the pseudo-second-order model. Both modifications methods reduced the surface area and pore volume. The studies show that the adsorption of MB and phenol onto modified CNTs is much more influenced by their surface functional group than their surface area and pore volume

The Full Range of Predictions for B Physics From Iso-singlet Down Quark Mixing

We extend the range of predictions of the isosinglet (or vector) down quark model to the fully allowed physical ranges, and also update this with the effect of new physics constraints. We constrain the present allowed ranges of sin(2*beta) and sin(2*alpha), gamma, x_s, and A_{B_s}. In models allowing mixing to a new isosinglet down quark (as in E_6) flavor changing neutral currents are induced that allow a Z^0 mediated contribution to B-Bbar mixing and which bring in new phases. In (rho, eta), (x_s, sin(gamma)), and (x_s, A_{B_s}) plots for the extra isosinglet down quark model which are herein extended to the full physical range, we find new allowed regions that will require experiments on sin(gamma) and/or x_s to verify or to rule out an extra down quark contribution.Comment: 13 pages in RevTeX, 7 postscript figure

Complete Nondiagonal Reflection Matrices of RSOS/SOS and Hard Hexagon Models

In this paper we compute the most general nondiagonal reflection matrices of the RSOS/SOS models and hard hexagon model using the boundary Yang-Baxter equations. We find new one-parameter family of reflection matrices for the RSOS model in addition to the previous result without any parameter. We also find three classes of reflection matrices for the SOS model, which has one or two parameters. For the hard hexagon model which can be mapped to RSOS(5) model by folding four RSOS heights into two, the solutions can be obtained similarly with a main difference in the boundary unitarity conditions. Due to this, the reflection matrices can have two free parameters. We show that these extra terms can be identified with the `decorated' solutions. We also generalize the hard hexagon model by `folding' the RSOS heights of the general RSOS(p) model and show that they satisfy the integrability conditions such as the Yang- Baxter and boundary Yang-Baxter equations. These models can be solved using the results for the RSOS models.Comment: 18pages,Late

Genetics-Based Population Pharmacokinetics and Pharmacodynamics of Risperidone in a Psychiatric Cohort.

BACKGROUND: High interindividual variability in plasma concentrations of risperidone and its active metabolite, 9-hydroxyrisperidone, may lead to suboptimal drug concentration. OBJECTIVE: Using a population pharmacokinetic approach, we aimed to characterize the genetic and non-genetic sources of variability affecting risperidone and 9-hydroxyrisperidone pharmacokinetics, and relate them to common side effects. METHODS: Overall, 150 psychiatric patients (178 observations) treated with risperidone were genotyped for common polymorphisms in NR1/2, POR, PPARα, ABCB1, CYP2D6 and CYP3A genes. Plasma risperidone and 9-hydroxyrisperidone were measured, and clinical data and common clinical chemistry parameters were collected. Drug and metabolite concentrations were analyzed using non-linear mixed effect modeling (NONMEM(®)). Correlations between trough concentrations of the active moiety (risperidone plus 9-hydroxyrisperidone) and common side effects were assessed using logistic regression and linear mixed modeling. RESULTS: The cytochrome P450 (CYP) 2D6 phenotype explained 52% of interindividual variability in risperidone pharmacokinetics. The area under the concentration-time curve (AUC) of the active moiety was found to be 28% higher in CYP2D6 poor metabolizers compared with intermediate, extensive and ultrarapid metabolizers. No other genetic markers were found to significantly affect risperidone concentrations. 9-hydroxyrisperidone elimination was decreased by 26% with doubling of age. A correlation between trough predicted concentration of the active moiety and neurologic symptoms was found (p = 0.03), suggesting that a concentration >40 ng/mL should be targeted only in cases of insufficient, or absence of, response. CONCLUSIONS: Genetic polymorphisms of CYP2D6 play an important role in risperidone, 9-hydroxyrisperidone and active moiety plasma concentration variability, which were associated with common side effects. These results highlight the importance of a personalized dosage adjustment during risperidone treatment

Period-Luminosity Relations Derived from the OGLE-III Fundamental Mode Cepheids

In this Paper, we have derived Cepheid period-luminosity (P-L) relations for the Large Magellanic Cloud (LMC) fundamental mode Cepheids, based on the data released from OGLE-III. We have applied an extinction map to correct for the extinction of these Cepheids. In addition to the VIW band P-L relations, we also include JHK and four Spitzer IRAC band P-L relations, derived by matching the OGLE-III Cepheids to the 2MASS and SAGE datasets, respectively. We also test the non-linearity of the Cepheid P-L relations based on extinction-corrected data. Our results (again) show that the LMC P-L relations are non-linear in VIJH bands and linear in KW and the four IRAC bands, respectively.Comment: 6 pages, 3 figures and 3 tables, ApJ accepte