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

COVID-19 reveals unequal urban citizenship in Manila, Dhaka and Delhi

The urban poor in the Global South have suffered special hardship as a result of the pandemic. Redento B Recio, Ishita Chatterjee (University of Melbourne) and Lutfun Nahar Lata (University of Queensland) describe the situation in Manila, Delhi and Dhaka, where abrupt lockdowns, mass movements to the countryside and woefully inadequate support have widened existing inequalities

Sinteza i spektroskopska analiza 5beta-kolan derivata

The facile synthesis and spectroscopic data analyses of three 5beta-cholane derivatives, 3beta-tosyloxy-5beta-cholan-24-ol (3), 5beta-cholan-24-ol (4) and 5eta-cholan-24-yl tosylate (5), have been described.Opisana je jednostavna sinteza i spektroskopska analiza tri derivata 5beta-kolana, 3beta-tosiloksi-5beta-kolan-24-ol (3), 5beta-kolan-24-ol (4) i 5beta-kolan-24-il tosilat (5)

Sinteza i spektroskopska analiza 5beta-kolan derivata

The facile synthesis and spectroscopic data analyses of three 5beta-cholane derivatives, 3beta-tosyloxy-5beta-cholan-24-ol (3), 5beta-cholan-24-ol (4) and 5eta-cholan-24-yl tosylate (5), have been described.Opisana je jednostavna sinteza i spektroskopska analiza tri derivata 5beta-kolana, 3beta-tosiloksi-5beta-kolan-24-ol (3), 5beta-kolan-24-ol (4) i 5beta-kolan-24-il tosilat (5)

Factorial structure of the locomotor disability scale in a sample of adults with mobility impairments in Bangladesh.

BACKGROUND: Disability does not only depend on individuals' health conditions but also the contextual factors in which individuals live. Therefore, disability measurement scales need to be developed or adapted to the context. Bangladesh lacks any locally developed or validated scales to measure disabilities in adults with mobility impairment. We developed a new Locomotor Disability Scale (LDS) in a previous qualitative study. The present study developed a shorter version of the scale and explored its factorial structure. METHODS: We administered the LDS to 316 adults with mobility impairments, selected from outpatient and community-based settings of a rehabilitation centre in Bangladesh. We did exploratory factor analysis (EFA) to determine a shorter version of the LDS and explore its factorial structure. RESULTS: We retained 19 items from the original LDS following evaluation of response rate, floor/ceiling effects, inter-item correlations, and factor loadings in EFA. The Eigenvalues greater than one rule and the Scree test suggested a two-factor model of measuring locomotor disability (LD) in adults with mobility impairment. These two factors are 'mobility activity limitations' and 'functional activity limitations'. We named the higher order factor as 'locomotor disability'. This two-factor model explained over 68% of the total variance among the LD indicators. The reproduced correlation matrix indicated a good model fit with 14% non-redundant residuals with absolute values > 0.05. However, the Chi-square test indicated poor model fit (p  .91. Among the retained 19 items, there was no correlation coefficient > .9 or a large number of correlation coefficients .3) cross loadings and the correlation between the two factors was .657. The 'mobility activity limitations' and 'functional activity limitations' sub-scales demonstrated excellent internal consistency (Cronbach's alpha were .954 and .937, respectively). CONCLUSIONS: The 19-item LDS was found to be a reliable and valid scale to measure the latent constructs mobility activity limitations and functional activity limitations among adults with mobility impairments in outpatient and community-based settings in Bangladesh

An Empirical Ultraviolet Template for Iron Emission in Quasars as Derived from I Zw 1

We present an empirical template spectrum suitable for fitting/subtracting and studying the FeII and FeIII line emission in the restframe UV spectra of active galatic nuclei (AGNs), the first empirical UV iron template to cover the full 1250 - 3090 A range. Iron emission is often a severe contaminant in optical--UV spectra of AGNs. Its presence complicates and limits the accuracy of measurements of both strong and weak emission lines and the continuum emission, affecting studies of line and continuum interrelations, the ionization structure, and elemental abundances in AGNs. Despite the wealth of work on modeling the AGN FeII emission and the need to account for it in observed AGN spectra, there is no UV template electronically available to aid this process. The iron template we present is based on HST spectra of the Narrow Line Seyfert 1, IZw1. Its intrinsic narrow lines (~900 km/s) and rich iron spectrum make the template particularly suitable for use with most AGN spectra. The iron emission spectrum and the line identifications and measurements are presented and compared with the work of Laor et al. We illustrate the application of the derived FeII and FeIII templates by fitting and subtracting the iron emission from UV spectra of four high-z quasars and of the nearby quasar, 3C273. We briefly discuss the small discrepancies between this observed iron emission and the UV template, and compare the template with previously published ones. We discuss the advantages and limitations of the templates and of the template fitting method. We conclude that the templates work sufficiently well to be a valuable and important tool for eliminating and studying the iron emission in AGNs, at least until accurate theoretical iron emission models are developed. (Abridged)Comment: 73 pages including 7 figures, 6 tables. To appear in ApJS. Preprint is also available at http://www.astronomy.ohio-state.edu/~vester/IronEmission

Rare Sarcomatoid Carcinoma of the Liver in a patient with no history of Hepatocellular Carcinoma: A Case Report

Sarcomatoid carcinoma is a rare malignant tumor of unknown pathogenesis characterized by poorly differentiated carcinoma tissue containing sarcoma-like differentiation of either spindle or giant cell and rarely occurs in the gastrointestinal tract and hepatobiliary-pancreatic system.1 Primary hepatic sarcomatoid carcinoma accounts for only 0.2 % of primary malignant liver tumors, and 1.8% of all surgically resected hepatocellular carcinomas.2 The majority of hepatic sarcomatoid carcinoma cases appear to occur simultaneously with hepatocellular or cholangiocellular carcinoma.3 The preferred treatment for hepatic sarcomatoid carcinoma is surgical resection and the overall prognosis is poor.4 This case depicts a 62-year-old female whom underwent initial resection in 2010 of a cavernous hemangioma. Seven years after her initial diagnosis she developed what was initially felt to be local recurrence of the hemangioma but additional diagnostic workup with a liver biopsy confirmed primary hepatic sarcomatoid carcinoma

Determining the status of chlorinated pesticide residue in some leafy vegetables

A study was carried out to identify the bioaccumulation and the ascertain level of chlorinated pesticide residues in three leafy vegetables viz. red amaranth, spinach and Indian spinach collected from city market. The samples were randomly collected from different shops and analyzed by capillary column of Gas Chromatograph Mass Spectrometry (GCMS) with Electron Impact Ionization (EI) method for the detection of chlorinated pesticide. The results of the study revealed that collected samples of red amaranth and spinach were contaminated with some chlorinated substances. But Indian spinach was free of contamination with organochlorine pesticide

OLAX SUBSCORPIOIDEA OLIV. (OLACACEAE): AN ETHNOMEDICINAL AND PHARMACOLOGICAL REVIEW

Background Olax subscorpioidea Oliv. (Olacaceae) is a woody shrub that is widely distributed in Africa. It has trado-medicinal importance and is used in the treatment of asthma, cancer, convulsion, diabetes, intestinal worm infections, jaundice, mental illnesses, neurodegenerative disorders, sexually transmitted infections, swellings and rheumatism, and yellow fever. Aims To review available literature on the phytochemistry, ethnobotany, pharmacology and toxicity of Olax subscorpioidea Oliv. Methods Published findings were searched in online databases such as Web of Science, Scopus, Pubmed, Google Scholar and other relevant sources, and the data were sorted by relevance.&nbsp; Combinations of keywords used in the search include Olax subscorpioidea, Olacaceae, Olax, Ewe Ifon, and African medicinal plants. Results The presence of alkaloids, anthraquinones, cardiac glycosides, flavonoids, phenolic compounds, proanthocyanidins, saponins, tannins and triterpenes has been reported from O. subscorpioidea. Cytotoxic santalbic acid was isolated from the methanol extract of the seed of this plant, while GC-MS and HPLC analyses of the n-butanol and n-hexane extracts of the leaf revealed the presence of caffeic acid, quercetin, morin, rutin, n-hexadecanoic acid (palmitic acid), 7,10,13-hexadecatrienoic acid and methyl ester, hentriacontane, 9,17-octadecadienal (Z)-, 9,12-octadecadienoic acid (Z,Z)-, squalene, nonacosane, octadecanoic acid. Bioactivity studies on this plant demonstrated its medicinal potential mainly as an analgesic, anthelmintic, anti-arthritic, antidepressant, antihyperglycaemic, anti-inflammatory, antioxidant, antimalarial and antimicrobial agent. Oral acute toxicity of the leaf extracts in rats appeared to be greater than 5,000 mg/kg body weight. Conclusion Published literature available to date on O. subscorpioidea provides some preliminary scientific basis for the ethnomedicinal uses of this plant. However, some ethnomedicinal uses have not been scientifically validated yet, and similarly, only a limited amount of information is available on properly isolated and identified phytochemicals from this plant that link to its bioactivitie