Cosmic histories of star formation and reionization: An analysis with a power-law approximation

With a simple power-law approximation of high-redshift ($\gtrsim3.5$) star formation history, i.e., $\dot{\rho}_*(z)\propto [(1+z)/4.5]^{-\alpha}$, we investigate the reionization of intergalactic medium (IGM) and the consequent Thomson scattering optical depth for cosmic microwave background (CMB) photons. A constraint on the evolution index $\alpha$ is derived from the CMB optical depth measured by the {\it Wilkinson Microwave Anisotropy Probe} (WMAP) experiment, which reads $\alpha\approx2.18\lg{\mathscr{N}_{\gamma}}-3.89$, where the free parameter $\mathscr{N}_\gamma$ is the number of the escaped ionizing ultraviolet photons per baryon. Moreover, the redshift for full reionization, $z_f$, can also be expressed as a function of $\alpha$ as well as $\mathscr{N}_{\gamma}$. By further taking into account the implication of the Gunn-Peterson trough observations to quasars for the full reionization redshift, i.e., $6\lesssim z_f \lesssim7$, we obtain $0.3\lesssim\alpha\lesssim1.3$ and $80\lesssim\mathscr{N}_{\gamma}\lesssim230$. For a typical number of $\sim4000$ of ionizing photons released per baryon of normal stars, the fraction of these photons escaping from the stars, $f_{\rm esc}$, can be constrained to within the range of $(2.0-5.8)$.Comment: 10 pages, 4 figures, accepted for publication in JCA

Production of Υ(nS) mesons in Pb+Pb and pp collisions at 5.02 TeV

A measurement of the production of vector bottomonium states, Υ ( 1S ) , Υ ( 2S ) , and Υ ( 3S ) , in Pb + Pb and p p collisions at a center-of-mass energy per nucleon pair of 5.02 TeV is presented. The data correspond to integrated luminosities of 1.38 nb − 1 of Pb + Pb data collected in 2018, 0.44 nb − 1 of Pb + Pb data collected in 2015, and 0.26 fb − 1 of p p data collected in 2017 by the ATLAS detector at the Large Hadron Collider. The measurements are performed in the dimuon decay channel for transverse momentum p μ μ T < 30 GeV , absolute rapidity | y μ μ | < 1.5 , and Pb + Pb event centrality 0–80%. The production rates of the three bottomonium states in Pb + Pb collisions are compared with those in p p collisions to extract the nuclear modification factors as functions of event centrality, p μ μ T , and | y μ μ | . In addition, the suppression of the excited states relative to the ground state is studied. The results are compared with theoretical model calculations

Fractal dimensions of time sequences

We present a simple and efficient way for calculating the fractal dimension D of any time sequence sampled at a constant time interval. We calculated the error of a piecewise interpolation to N + 1 points of the time sequence with respect to the next level of (2N + 1)-point interpolation. This error was found to be proportional to the scale (i.e., 1/N) to the power of 1 - D. A simple analysis showed that our method is equivalent to the inverse process of the method of random midpoint displacement widely used in generating fractal Brownian motion for a given D. The efficiency of our method makes the fractal dimension a practical tool in analyzing the abundant data in natural, economic, and social sciences. (C) 2009 Elsevier B.V. All rights reserved

Effects of protective colloids upon properties of ethylcellulose microcapsules prepared from various non-solvent addition methods

Preparation of ethylcellulose microcapsules containing theophylline was performed by simple non-solvent addition and emulsion non-solvent addition methods in the presence of polybutadiene or polyisobutylene as a protective colloid. The effects of the protective colloids upon the properties of microcapsules with respect to the size distribution, drug content, ethylcellulose loss and porosity were characterized. The results indicate that, in the presence of an appropriate amount of the protective colloid, the extent of aggregation was reduced and the surface became smoother and less porous. Mononucleated microcapsules were obtained by the emulsion non-solvent addition method in the presence of polyisobutylene. Owing to the occurrence of aggregation, the theophylline release from microcapsules appeared to follow the diffusion-controlled matrix model, the release rate being dependent upon the extent of aggregation and the porosity of microcapsules

Fractal Analysis of Stock Index and Electrocardiograph

We use the modified inverse random midpoint displacement (mIRMD) method to calculate the fractal dimensions of time sequences of arbitrary length. We show that monofractals, crossover-fractals, and the superposition of a fractal, with either a differentiable or periodic function, can be easily identified from the results calculated by the mIRMD. We compare our method with the method of detrended fluctuation analysis (DFA) and point out their differences. We apply our method to real financial and physiological data by considering the movement of the S&P 500 stock index and the electrocardiograph of a patient with ventricular fibrillation

An approach to fabricating microstructures that incorporate circuits using a post-CMOS process

This study proposes a method of fabricating microstructures that incorporate circuits using a standard CMOS (complementary metal oxide semiconductor) process and a post-process. The post-process has two main steps. One uses a photoresist (PR) mask to protect the bonding pads, the circuits and the unneeded etched regions in the chip. The other step employs CF4/O-2 RIE (reactive ion etching) and SF6/O-2 RIE to etch the sacrificial layers to release the suspended microstructures. A 5.8 GHz low-noise amplifier (LNA) was employed to verify whether the post-process affects the performance of the circuits or not. The test results indicated that the performance of the LNA was the same before and after the post-process, proving that the post-process did not change the functionality of the circuits. Hence, the advantage of the post-process is that it does not damage the bonding pads, the passivation layers and the circuits, which are protected by the PR mask

Prenatal smoking exposure and neonatal DNA damage in relation to birth outcomes

This study investigated whether mothers with prenatal environmental tobacco smoke (ETS) exposure increased the newborn genetic damage and adverse birth outcomes. Study participants were women receiving prenatal care at three hospitals in Central Taiwan and their newborns. Participants were divided into two groups (nonsmokers and ETS-exposed non-smokers) based on maternal ETS-exposed status. Comet assay were performed for cord blood samples. Infants born to mothers with prenatal ETS exposure had the highest mean cord blood DNA damage score (69.7 +/- 42.3) and poorer birth outcomes. No negative fetal growth effects appeared among new-borns with low DNA damage levels. Among newborns with high DNA damage levels (comet scores > 50), those born to prenatal ETS exposure had an average reduction of 252.7 g in birth weight, 1.10 cm shorter in length and a 0.92-cm decrease in head circumference, compared to newborns with no smoking exposure. This study shows that the DNA damage scores can be used as an effect-modifier on the relationships between ETS exposure and adverse birth outcome. The association appears more apparent for the ETS exposure in relation with more severe DNA damage

Development of an enzyme-linked immunosorbent assay for detecting infectious bursal disease virus (IBDV) infection based on the VP3 structural protein

Infectious bursal disease virus (IBDV) causes a contagious immunosuppressive disease in chickens. The aim of the present study is to develop an enzyme-linked immunosorbent assay (ELISA) using the expressed VP2 or VP3 protein of IBDV as the coating antigen for detecting antibodies to IBDV. Experimental results were compared with virus neutralization assay and a commercial-available ELISA. These assays were used to examine the sera from farm chickens and chickens vaccinated experimentally. The VP3-based ELISA had a higher correlation coefficient (R-2) of 0.812 with a commercial ELISA kit at a serum dilution of 1:500 than that of VP2-based ELISA (R-2) of 0.671. The relative sensitivity between virus neutralization and VP2-ELISA and VP3-ELISA was 96% (251/262) and 100% (262/262), respectively, and that between virus neutralization and a commercial ELISA was 99% (257/261). Additionally, compared with virus neutralization assay, the reference technique for diagnosing IBDV, VP3-based ELISA had an agreement value of 99%, superior to that of VP2-based ELISA (95%) or the commercial kit (89%). These results revealed that the capability of either VP2-ELISA or VP3-ELISA in detecting the field chicken sera was comparable to the commercial one, which is generally used to replace the virus neutralization assay. However, the preparation of VP3 is derived from an Escherichia coli expression system with a high yield and purification efficiency by Ni2+-NTA gels, which is more favorable to the insect cell-derived particles formed by VP2. Therefore, VP3-ELISA could be developed as an efficient and low cost diagnostic method for IBDV infection in field chickens. (C) 2008 Elsevier B.V. All rights reserved