Ices in the edge-on disk CRBR 2422.8-3423: Spitzer spectroscopy and Monte Carlo radiative transfer modeling

We present 5.2-37.2 micron spectroscopy of the edge-on circumstellar disk CRBR 2422.8-3423 obtained using the InfraRed Spectrograph (IRS) of the Spitzer Space Telescope. The IRS spectrum is combined with ground-based 3-5 micron spectroscopy to obtain a complete inventory of solid state material present along the line of sight toward the source. We model the object with a 2D axisymmetric (effectively 3D) Monte Carlo radiative transfer code. It is found that the model disk, assuming a standard flaring structure, is too warm to contain the very large observed column density of pure CO ice, but is possibly responsible for up to 50% of the water, CO2 and minor ice species. In particular the 6.85 micron band, tentatively due to NH4+, exhibits a prominent red wing, indicating a significant contribution from warm ice in the disk. It is argued that the pure CO ice is located in the dense core Oph-F in front of the source seen in the submillimeter imaging, with the CO gas in the core highly depleted. The model is used to predict which circumstances are most favourable for direct observations of ices in edge-on circumstellar disks. Ice bands will in general be deepest for inclinations similar to the disk opening angle, i.e. ~70 degrees. Due to the high optical depths of typical disk mid-planes, ice absorption bands will often probe warmer ice located in the upper layers of nearly edge-on disks. The ratios between different ice bands are found to vary by up to an order of magnitude depending on disk inclination due to radiative transfer effects caused by the 2D structure of the disk. Ratios between ice bands of the same species can therefore be used to constrain the location of the ices in a circumstellar disk. [Abstract abridged]Comment: 49 pages, accepted for publication in Ap

Anti‐cN‐1A autoantibodies are absent in juvenile dermatomyositis

Objectives: To assess anti‐cytosolic 5′‐nucleotidase 1A (cN‐1A/NTC51A) autoantibodies in children with juvenile dermatomyositis (JDM) and healthy controls, using three different methods of antibody detection, as well as verification of the results in an independent cohort. / Methods: Anti‐cN‐1A reactivity was assessed in 34 Dutch JDM patients and 20 healthy juvenile controls by a commercially available full‐length cN‐1A ELISA, a synthetic peptide ELISA and by immunoblotting using a lysate from cN‐1A expressing HEK‐293 cells. Sera from JDM patients with active disease and in remission were analysed. An independent British cohort of 110 JDM patients and 43 healthy juvenile controls was assessed by an in‐house full‐length cN‐1A ELISA. / Results: Anti‐cN‐1A reactivity was not present in JDM patients’ sera or in healthy controls when tested with the commercially available full‐length cN‐1A ELISA or by immunoblotting, both in active disease and in remission. Also, in the British JDM cohort anti‐cN‐1A reactivity was not detected. Three Dutch JDM patients tested weakly positive for one of the three synthetic cN‐1A peptides measured by ELISA. / Conclusion: JDM patients and young healthy individuals do not show anti‐cN‐1A reactivity as assessed by different antibody detection techniques

Quantifying Nonspecific TEM -Lactamase (blaTEM) Genes in a Wastewater Stream

To control the antibiotic resistance epidemic, it is necessary to understand the distribution of genetic material encoding antibiotic resistance in the environment and how anthropogenic inputs, such as wastewater, affect this distribution. Approximately two-thirds of antibiotics administered to humans are β-lactams, for which the predominant bacterial resistance mechanism is hydrolysis by β-lactamases. Of the β-lactamases, the TEM family is of overriding significance with regard to diversity, prevalence, and distribution. This paper describes the design of DNA probes universal for all known TEM β-lactamase genes and the application of a quantitative PCR assay (also known as Taqman) to quantify these genes in environmental samples. The primer set was used to study whether sewage, both treated and untreated, contributes to the spread of these genes in receiving waters. It was found that while modern sewage treatment technologies reduce the concentrations of these antibiotic resistance genes, the ratio of blaTEM genes to 16S rRNA genes increases with treatment, suggesting that bacteria harboring blaTEM are more likely to survive the treatment process. Thus, β-lactamase genes are being introduced into the environment in significantly higher concentrations than occur naturally, creating reservoirs of increased resistance potential.Organismic and Evolutionary Biolog

Asthma phenotyping in primary care : applying the International Severe Asthma Registry eosinophil phenotype algorithm across all asthma severities.

Funding: The OPCRD is established and maintained by Optimum Patient Care (OPC) Ltd. This study was funded by AstraZeneca and conducted collaboratively with the OPRI Pte Ltd and OPC Global Ltd. Acknowledgements We thank James Zangrilli, MD, and the entire ISAR Steering Committee for their valued contribution to the design of the study and interpretation of findingsPeer reviewedPublisher PD

DNA Nucleobase Synthesis at Titan Atmosphere Analog by Soft X-rays

Titan, the largest satellite of Saturn, has an atmosphere chiefly made up of N2 and CH4 and includes traces of many simple organic compounds. This atmosphere also partly consists of haze and aerosol particles which during the last 4.5 gigayears have been processed by electric discharges, ions, and ionizing photons, being slowly deposited over the Titan surface. In this work, we investigate the possible effects produced by soft X-rays (and secondary electrons) on Titan aerosol analogs in an attempt to simulate some prebiotic photochemistry. The experiments have been performed inside a high vacuum chamber coupled to the soft X-ray spectroscopy beamline at the Brazilian Synchrotron Light Source, Campinas, Brazil. In-situ sample analyses were performed by a Fourier transform infrared spectrometer. The infrared spectra have presented several organic molecules, including nitriles and aromatic CN compounds. After the irradiation, the brownish-orange organic residue (tholin) was analyzed ex-situ by gas chromatographic (GC/MS) and nuclear magnetic resonance (1H NMR) techniques, revealing the presence of adenine (C5H5N5), one of the constituents of the DNA molecule. This confirms previous results which showed that the organic chemistry on the Titan surface can be very complex and extremely rich in prebiotic compounds. Molecules like these on the early Earth have found a place to allow life (as we know) to flourish.Comment: To appear in Journal of Physical Chemistry A.; Number of pages: 6; Number of Figures: 5; Number of Tables: 1; Number of references:49; Full paper at http://pubs.acs.org/doi/abs/10.1021/jp902824