A quasi-time-dependent radiative transfer model of OH104.9+2.4

We investigate the pulsation-phase dependent properties of the circumstellar dust shell (CDS) of the OH/IR star OH104.9+2.4 based on radiative transfer modeling (RTM) using the code DUSTY. Our previous study concerning simultaneous modeling of the spectral energy distribution (SED) and near-infrared (NIR) visibilities (Riechers et al. 2004) has now been extended by means of a more detailed analysis of the pulsation-phase dependence of the model parameters of OH104.9+2.4. In order to investigate the temporal variation in the spatial structure of the CDS, additional NIR speckle interferometric observations in the K' band were carried out with the 6 m telescope of the Special Astrophysical Observatory (SAO). At a wavelength of 2.12 micron the diffraction-limited resolution of 74 mas was attained. Several key parameters of our previous best-fitting model had to be adjusted in order to be consistent with the newly extended amount of observational data. It was found that a simple rescaling of the bolometric flux F_bol is not sufficient to take the variability of the source into account, as the change in optical depth over a full pulsation cycle is rather high. On the other hand, the impact of a change in effective temperature T_eff on SED and visibility is rather small. However, observations, as well as models for other AGB stars, show the necessity of including a variation of T_eff with pulsation phase in the radiative transfer models. Therefore, our new best-fitting model accounts for these changes.Comment: 7 pages, including 5 postscript figures and 3 tables. Published in Astronomy and Astrophysics. (v1: accepted version; v2: published version, minor grammatical changes

Interplay between carrier and impurity concentrations in annealed Ga1−x_{1-x}Mnx_{x}As intrinsic anomalous Hall Effect

Investigating the scaling behavior of annealed Ga$_{1-x}$Mn$_{x}$As anomalous Hall coefficients, we note a universal crossover regime where the scaling behavior changes from quadratic to linear, attributed to the anomalous Hall Effect intrinsic and extrinsic origins, respectively. Furthermore, measured anomalous Hall conductivities when properly scaled by carrier concentration remain constant, equal to theoretically predicated values, spanning nearly a decade in conductivity as well as over 100 K in T$_{C}$. Both the qualitative and quantitative agreement confirms the validity of new equations of motion including the Berry phase contributions as well as tunablility of the intrinsic anomalous Hall Effect.Comment: 4 pages, 5 figure

An On-chip Optical Brillouin Gyroscope with Earth-Rotation-Rate Sensitivity

A chip-based gyroscope is demonstrated that uses counter-propagating Brillouin lasers to measure rotation as a Sagnac-induced frequency shift. Demonstration of rotation measurement below the Earth rotation rate is presented. Prospects for improved performance are discussed

On the thickness uniformity of micropatterns of hyaluronic acid in a soft lithographic molding method

A soft lithographic molding is a simple and yet robust method for fabricating well-defined microstructures of a hydrophilic biopolymer such as polyethylene glycol and polysaccharide over a large area. The method consists of three steps: placing a polydimethylsiloxane mold with a bas-relief pattern onto a drop-dispensed polymer solution typically dissolved in water, letting the mold and the solution undisturbed in contact until solvent evaporates completely, and leaving behind a polymer replica after mold removal. In such a molding process, water can only evaporate from the edges of the mold due to impermeable nature of polydimethylsiloxane to water, resulting in a nonuniform distribution of film thickness or pattern height. Here we examine systematically how the evaporation rate affects the thickness distribution of the resulting microstructures by evaporating the solution of hyaluronic acid in various conditions. To compare with a theory, we also present a simple theoretical model based on one-dimensional conservation equation for a liquid film, which is in good agreement with the experimental data. (C) 2005 American Institute of Physicsclose4

Differential expression of circulating microRNAs according to severity of colorectal neoplasia

There is a need to develop a colorectal cancer (CRC) screening test that is noninvasive, cost effective, and sensitive enough to detect preneoplastic lesions. This case-control study examined the feasibility of using circulating extracellular microRNAs (miRNAs) to differentiate a spectrum of colorectal neoplasia of various severity and hence for early detection of colorectal neoplasia. Archived serum samples of 10 normal controls and 31 cases, including 10 with nonadvanced adenoma, 10 with advanced adenoma, and 11 with CRC, were profiled for circulating miRNAs using next-generation sequencing. Multiple linear regression, adjusting for age, gender, and smoking status, compared controls and the 3 case groups for levels of 175 miRNAs that met stringent criteria for miRNA sequencing analysis. Of the 175 miRNAs, 106 miRNAs were downregulated according to severity of neoplasia and showed a relative decrease in the expression from controls to nonadvanced adenoma to advanced adenoma to CRC (Ptrend \u3c 0.05). Pairwise group comparisons showed that 39 and 80 miRNAs were differentially expressed in the advanced adenoma and CRC groups compared with the controls, respectively. Differences in miRNA levels between the nonadvanced adenoma group and controls were modest. Our study found that expression of many miRNAs in serum was inversely correlated with the severity of colorectal neoplasia, and differential miRNA profiles were apparent in preneoplastic cases with advanced lesions, suggesting circulating miRNAs could serve as potential biomarkers for CRC screening