Radiative transfer with scattering for domain-decomposed 3D MHD simulations of cool stellar atmospheres

We present the implementation of a radiative transfer solver with coherent scattering in the new BIFROST code for radiative magneto-hydrodynamical (MHD) simulations of stellar surface convection. The code is fully parallelized using MPI domain decomposition, which allows for large grid sizes and improved resolution of hydrodynamical structures. We apply the code to simulate the surface granulation in a solar-type star, ignoring magnetic fields, and investigate the importance of coherent scattering for the atmospheric structure. A scattering term is added to the radiative transfer equation, requiring an iterative computation of the radiation field. We use a short-characteristics-based Gauss-Seidel acceleration scheme to compute radiative flux divergences for the energy equation. The effects of coherent scattering are tested by comparing the temperature stratification of three 3D time-dependent hydrodynamical atmosphere models of a solar-type star: without scattering, with continuum scattering only, and with both continuum and line scattering. We show that continuum scattering does not have a significant impact on the photospheric temperature structure for a star like the Sun. Including scattering in line-blanketing, however, leads to a decrease of temperatures by about 350\,K below log tau < -4. The effect is opposite to that of 1D hydrostatic models in radiative equilibrium, where scattering reduces the cooling effect of strong LTE lines in the higher layers of the photosphere. Coherent line scattering also changes the temperature distribution in the high atmosphere, where we observe stronger fluctuations compared to a treatment of lines as true absorbers.Comment: A&A, in pres

Electron-Ion Recombination Rate Coefficients and Photoionization Cross Sections for Astrophysically Abundant Elements. V. Relativistic calculations for Fe XXIV and Fe XXV for X-ray modeling

Photoionization and recombination cross sections and rate coefficients are calculated for Li-like Fe XXIV and He-like Fe XXV using the Breit-Pauli R-matrix (BPRM) method. A complete set of total and level-specific parameters is obtained to enable X-ray photoionization and spectral modeling. The ab initio calculations for the unified (e + ion) recombination rate coefficients include both the non-resonant and the resonant recombination (radiative and di-electronic recombination, RR and DR, respectively) for (e + Fe XXV) -> Fe XXIV and (e + Fe XXVI) -> Fe XXV. The level specific rates are computed for all fine structure levels up to n = 10, enabling accurate computation of recombination-cascade matrices and effective rates for the X-ray lines. The total recombination rate coefficients for both Fe XXIV and Fe XXV differ considerably, by several factors, from the sum of RR and DR rates currently used to compute ionization fractions in astrophysical models. As the photoionization/recombination calculations are carried out using an identical eigenfunction expansion, the cross sections for both processes are theoretically self-consistent; the overall uncertainty is estimated to be about 10-20%. All data for Fe XXIV and Fe XXV (and also for H-like Fe XXVI, included for completeness) are available electronically.Comment: 31 pages, 10fug

On certain subclasses of p-valent functions defined in terms of certain fractional derivative operators

In the present paper we study certain subclasses Hλ,μ,η(a,b,pσ) and Kλ,μ,η(a,b,pσ) of analytic and p-valent functions. The results presented include coefficient estimates and distorsion properties for functions belonging to such classes. Further results giving closure theorems, various properties and modified Hadamard products of several functions belonging to above classes are also mentioned

Validated method for the quantification of buprenorphine in postmortem blood using solid-phase extraction and two-dimensional gas chromatography–mass spectrometry

A highly sensitive and fully validated method was developed for the quantification of buprenorphine in postmortem blood. After a two-step protein precipitation process using acetonitrile, buprenorphine was purified using mixed-mode (C8/cation exchange) solid-phase extraction cartridges. Endogenous water-soluble compounds and lipids were removed from the cartridges before the samples were eluted, concentrated and derivatized using N-methyl-N-trimethylsilyltrifluoroacetamide. The samples were analyzed using two-dimensional gas chromatography–mass spectrometry (2D GC–MS) in selective ion-monitoring mode. A low polarity Rxi®-5MS (30 m × 0.25 mm I.D. × 0.25 µm) was used as the primary column and the secondary column was a mid-polarity Rxi® -17Sil MS (15 m × 0.32 mm I.D. × 0.25 µm). The assay was linear from 1.0 to 50.0 ng/mL (r2 > 0.99; n = 6). Intraday (n = 6) and interday (n = 9) imprecisions (percentage relative standard deviation, % RSD) were <5% and the average recovery was 60%. The limit of detection (LOD) of the method was 0.5 ng/mL and limit of quantification was 1.0 ng/mL. 2D GC–MS improved the LOD of buprenorphine by 20-fold compared with analysis on a conventional GC–MS. The method was highly selective with no interference from endogenous compounds or from 62 commonly encountered drugs. To prove method applicability to forensic postmortem cases, 14 authentic postmortem blood samples were analyzed

GABA-B receptor function in healthy volunteers, a pharmacokinetic and pharmacodynamic study of two doses of baclofen compared to placebo

AIMS AND HYPOTHESIS To assess the subjective and objective effects of baclofen on brain function in healthy volunteers. BACKGROUND Recent evidence suggests baclofen, a γ-aminobutyric acid type B (GABA-B) receptor agonist, reduces alcohol consumption and craving and promotes abstinence in alcoholics. However, characterisation of the GABA-B receptor system in clinical addiction is limited, and it is unclear why some patients require, or tolerate, higher doses to treat alcoholism. This study assesses the effects of baclofen on brain function in healthy volunteers to inform future studies investigating the sensitivity of GABA-B receptors in alcohol addiction. METHODS Eight healthy male volunteers completed a double blind randomised 3-way cross over study, receiving oral placebo (vitamin C 100mg), 10mg and 60mg baclofen. Subjective and objective measurements were taken at baseline (before medication) and at +30mins, 1, 2, 3, 4 and 6 hours after dosing. Objective measures included blood plasma samples, heart rate and blood pressure. Subjective measures included; the Subjective High Assessment Questionnaire (SHAS), visual analogue scales for sleepy, relaxed, tense and alert and a motor coordination task (zig-zag task). Pharmacokinetic data was obtained using liquid chromatography mass-spectrometry (LC-MS) to measure plasma baclofen concentrations. RESULTS 60mg Baclofen showed changes in subjective measures peaking at 2 hours post dosing compared with placebo, including a significant increase (p<0.05) in total SHAS scores with individual items, including feeling ‘drunk or intoxicated’, effects of alcohol and ‘muddled or confused’ particular affected.. Systolic blood pressure was significantly increased (p<0.05) at the 2 hours post 60mg dose. For both 10mg and 60mg baclofen, peak plasma concentration was achieved 60 minutes post dose. Pharmacokinetic data will be presented. There were no significant changes in these measures between 10mg Baclofen and placebo. CONCLUSIONS The objective and subjective measures used in this study are able to differentiate between placebo and 60mg baclofen. These findings will inform further research investigating the sensitivity of GABA-B receptors in alcohol addiction

Efficient Cell Phone Keypad Designing for Bangla SMS Using English Alphabets

Mobile phone networks are increasingly supporting the transmission of textual message between individuals. In this paper we have introduced a new approach that will enhance the speed of typing process in Bangla by using English mobile keypad. An example of making Bangla sentences using English keypad could be “Ami valo achiâ€. Traditional cell phone keypad is not suitable for Bangla typing using English alphabets and number of key pressing is high to make such Bangla SMS (Short Message Service). The proposed approach has been explored to speed up the typing process in Bangla using English alphabets. The alphabets are rearranged according to the priority of frequencies. The frequency of alphabet is appeared by most used letter in SMS. The letters which are mostly used are recognized as higher frequency. The proposed design consumes less time for typing Bangla SMS using English letter format. Keywords: Mobile keypad, unitap, multitap, Bangla SMS, frequency

Microbial and heavy metal contaminant of antidiabetic herbal preparations formulated in Bangladesh

The aim of the current study was to evaluate microbial contamination in terms of microbial load (total aerobic count and total coliform count) and specific pathogenic bacteria (Salmonella spp., Escherichia coli, particularly Escherichia coli 0157) in thirteen antidiabetic herbal preparations (ADHPs) from Dhaka City. All the thirteen ADHPs had been found contaminated with fungi and different pathogenic bacteria. From the data, it is found that only two of these preparations (ADHP-1 and ADHP-12) complied with the safety limit (as stated in different Pharmacopoeias and WHO guidelines) evaluated by all different microbial counts. None of these herbal preparations could assure the safety as all of them were contaminated by fungi. The overall safety regarding heavy metal content (Zn, Cu, Mn, Cr, Cd, and Pb) was assured as none of them exceeded the safety limit of the daily intake. Microbial contaminants in these herbal preparations pose a potential risk for human health and care should be taken in every step involved in the preparation of these herbal preparations to assure safety.Rausan Zamir, Anowar Hosen, M. Obayed Ullah, and Nilufar Naha

The FERRUM project: Transition probabilities for forbidden lines in [FeII] and experimental metastable lifetimes

Accurate transition probabilities for forbidden lines are important diagnostic parameters for low-density astrophysical plasmas. In this paper we present experimental atomic data for forbidden [FeII] transitions that are observed as strong features in astrophysical spectra. Aims: To measure lifetimes for the 3d^6(^3G)4s a ^4G_{11/2} and 3d^6(^3D)4s b ^4D_{1/2} metastable levels in FeII and experimental transition probabilities for the forbidden transitions 3d^7 a ^4F_{7/2,9/2}- 3d^6(^3G)4s a ^4G_{11/2}. Methods: The lifetimes were measured at the ion storage ring facility CRYRING using a laser probing technique. Astrophysical branching fractions were obtained from spectra of Eta Carinae, obtained with the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope. The lifetimes and branching fractions were combined to yield absolute transition probabilities. Results: The lifetimes of the a ^4G_{11/2} and the b ^4D_{1/2} levels have been measured and have the following values, 0.75(10) s and 0.54(3) s respectively. Furthermore, we have determined the transition probabilities for two forbidden transitions of a ^4F_{7/2,9/2}- a ^4G_{11/2} at 4243.97 and 4346.85 A. Both the lifetimes and the transition probabilities are compared to calculated values in the literature.Comment: 5 pages, accepted for publication in A&

Actividad antibacteriana y antioxidante de los extractos de Piper cubeba (Piperaceae)

Piper cubeba L. (Piperaceae), commonly known as ‘cubeb’, is native to Indonesia, and also found in many other countriesof the South-East Asia, and in some African countries. This plant has been used as a popular food additive, andin folklore medicine to treat various ailments, particularly bacterial infections. The n-hexane, dichloromethane (DCM)and methanol (MeOH) extracts of the dried berries (fruit) of this plant were assessed for their antioxidant (free radicalscavenging) and antibacterial activities using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and the micro titre basedantimicrobial assay incorporating resazurin as an indicator of cell growth, respectively. While all extracts showed antioxidantactivity in the qualitative assay, the most prominent antioxidant activity was observed with the MeOH extract inthe quantitative assay with a RC50 value of 2.71 x 10-1 mg/mL. The antioxidant potency of the DCM extract was about3 fold less (RC50 = 6.50 x 10-1 mg/mL) than that of the MeOH extract. None of the extracts showed any antibacterialproperty against Bacillus subtilis, Escherichia coli, and ampicillin resistant Escherichia coli. While both the n-hexaneand the DCM extracts inhibited the growth of Bacillus cereus, Pseudomonas aeruginosa and Staphylococcus aureus, theMeOH extract was active only against B. cereus and P. aeruginosa. The most potent antibacterial activity was displayedby the n-hexane extract against B. cereus with an MIC value of 1.56 mg/mL. All antibacterial activities of the extractswere found to be bacteriostatic rather than bactericidal.Piper cubeba L. (Piperaceae), conocida comúnmente como ‘cubeb’, es autóctona de Indonesia y también se encuentraen muchos otros países del sureste de Asia, así como en algunos países africanos.Esta planta se ha utilizado como un popular aditivo alimentario y, en la medicina tradicional, para tratar diversasdolencias, especialmente infecciones bacterianas. Para evaluar la actividad antioxidante (barrido de radicales libres)y la actividad antibacteriana de los extractos de n-hexano, diclorometano (DCM) y metanol (MeOH) de las bayassecas (fruto) de esta planta, se llevó a cabo un ensayo 2,2-difenil-1-picrilhidracil (DPPH) y un ensayo antimicrobianobasado en microtitulación que incorporaba resazurina como indicador del crecimiento celular, respectivamente. Aunquetodos los extractos mostraron actividad antioxidante en el ensayo cualitativo, la actividad antioxidante más destacadase observó con el extracto de MeOH en el ensayo cuantitativo con un valor de RC50 de 2,71 x 10-1 mg/mL.La potencia antioxidante del extracto de DCM fue aproximadamente 3 veces menor (RC50 = 6,50 x 10-1 mg/mL)que la del extracto de MeOH.Ninguno de los extractos mostró propiedades antibacterianas frente a Bacillus subtilis, Escherichia coli y Escherichiacoli resistente a la ampicilina. Aunque ambos extractos, el n-hexano y el DCM, inhibieron el crecimiento de Bacilluscereus, Pseudomonas aeruginosa y Staphylococcus aureus, el extracto de MeOH sólo mostró actividad frente a B.cereus y P. aeruginosa. El extracto de n-hexano fue el que mostró mayor potencia antibacteriana frente a B. cereus,con un valor de concentración inhibitoria mínima (CIM) de 1,56 mg/mL. Se observó que todas las actividades antibacterianasde los extractos resultaron más bacteriostáticas que bactericidas

Derivati feniloctene kiseline s antioksidativnim učinkom iz sjemenki biljke Ilex aquifolium

Reversed-phase preparative HPLC analysis of the methanol extract of the seeds of Ilex aquifolium afforded two antioxidant phenylacetic acid derivatives, 2,4-dihydroxyphenylacetic acid (1) and 2,4-dihydroxyphenylacetic acid methyl ester (2). The structures were determined by spectroscopic methods. In the DPPH assay for antioxidant activity, the IC50 values of 1 and 2 were 1.50 x 10-3 and 2.55 x 10-3 mg mL-1, respectively, compared to 2.88 x 10-5 mg mL-1 of quercetin, a natural antioxidant.Reverzno-faznom preparativnom HPLC analizom metanolnog ekstrakta sjemenki biljke Ilex aquifolium izolirana su dva derivata feniloctene kiseline s antioksidativnim učinkom, 2,4-dihidroksifeniloctena kisleina (1) i metilni ester 2,4-dihidroksifeniloctene kiseline (2). Njihove strukture određene su spektroskopskim metodama. U DPPH testu na antioksidativno djelovanje, IC50 vrijednosti spojeva 1 i 2 bile su 1.50 x 10-3 i 2.55 x 10-3 mg mL-1, dok je IC50 prirodnog antioksidansa kvercitina bila 2.88 x 10-5 mg mL-1