Spectroscopic parameters for silacyclopropynylidene, SiC2_2, from extensive astronomical observations toward CW Leo (IRC +10216) with the Herschel satellite

A molecular line survey has been carried out toward the carbon-rich asymptotic giant branch star CW Leo employing the HIFI instrument on board of the Herschel satellite. Numerous features from 480 GHz to beyond 1100 GHz could be assigned unambiguously to the fairly floppy SiC$_2$ molecule. However, predictions from laboratory data exhibited large deviations from the observed frequencies even after some lower frequency data from this survey were incorporated into a fit. Therefore, we present a combined fit of all available laboratory data together with data from radio-astronomical observations.Comment: 7 pages, 1 figure, J. Mol. Spectrosc., appeared; CDMS links corrected (version 2; current version: 3; may be updated later this year

Astronomical identification of CN-, the smallest observed molecular anion

We present the first astronomical detection of a diatomic negative ion, the cyanide anion CN-, as well as quantum mechanical calculations of the excitation of this anion through collisions with para-H2. CN- is identified through the observation of the J = 2-1 and J = 3-2 rotational transitions in the C-star envelope IRC +10216 with the IRAM 30-m telescope. The U-shaped line profiles indicate that CN-, like the large anion C6H-, is formed in the outer regions of the envelope. Chemical and excitation model calculations suggest that this species forms from the reaction of large carbon anions with N atoms, rather than from the radiative attachment of an electron to CN, as is the case for large molecular anions. The unexpectedly large abundance derived for CN-, 0.25 % relative to CN, makes likely its detection in other astronomical sources. A parallel search for the small anion C2H- remains so far unconclusive, despite the previous tentative identification of the J = 1-0 rotational transition. The abundance of C2H- in IRC +10216 is found to be vanishingly small, < 0.0014 % relative to C2H.Comment: 5 pages, 4 figures; accepted for publication in A&A Letter

Type I Interferons Link Viral Infection to Enhanced Epithelial Turnover and Repair

The host immune system functions constantly to maintain chronic commensal and pathogenic organisms in check. The consequences of these immune responses on host physiology are as yet unexplored, and may have long-term implications in health and disease. We show that chronic viral infection increases epithelial turnover in multiple tissues, and the antiviral cytokines type I interferons (IFNs) mediate this response. Using a murine model with persistently elevated type I IFNs in the absence of exogenous viral infection, the Irgm1−/− mouse, we demonstrate that type I IFNs act through nonepithelial cells, including macrophages, to promote increased epithelial turnover and wound repair. Downstream of type I IFN signaling, the highly related IFN-stimulated genes Apolipoprotein L9a and b activate epithelial proliferation through ERK activation. Our findings demonstrate that the host immune response to chronic viral infection has systemic effects on epithelial turnover through a myeloid-epithelial circuit

A lambda = 1.3 mm and 2 mm molecular line survey towards M82

We study the chemical complexity towards the central parts of the starburst galaxy M82, and investigate the role of certain molecules as tracers of the physical processes in the galaxy circumnuclear region. We carried out a spectral line survey with the IRAM-30m telescope towards the northeastern molecular lobe of M82. It covers the frequency range between 129.8 GHz and 175.0 GHz in the 2 mm atmospheric window, and between 241.0 GHz and 260.0 GHz in the 1.3 mm atmospheric window. Sixty-nine spectral features corresponding to 18 different molecular species are identified. In addition, three hydrogen recombination lines are detected. The species NO, H2S, H2CS, NH2CN, and CH3CN are detected for the first time in this galaxy. Assuming local thermodynamic equilibrium, we determine the column densities of all the detected molecules. We also calculated upper limits to the column densities of fourteen other important, but undetected, molecules, such as SiO, HNCO, or OCS. We compare the chemical composition of the two starburst galaxies M82 and NGC253. This comparison enables us to establish the chemical differences between the products of the strong photon-dominated regions (PDRs) driving the heating in M82, and the large-scale shocks that influence the properties of the molecular clouds in the nucleus of NGC253. Overall, both sources have different chemical compositions. Some key molecules highlight the different physical processes dominating both central regions. Examples include CH3CCH, c-C3H2, or CO+, the abundances of which are clearly higher in M82 than in NGC253, pointing at photodissociating regions. On the other hand, species such as CH2NH, NS, SiO, and HOCO+ have abundances of up to one order of magnitude higher in NGC253 than in M82.Comment: Accepted for publication in A&A. 19 pages, 8 figures, 3 table

Molecular dynamics simulations of the Cx26 hemichannel: Evaluation of structural models with Brownian dynamics

The recently published crystal structure of the Cx26 gap junction channel provides a unique opportunity for elucidation of the structure of the conductive connexin pore and the molecular determinants of its ion permeation properties (conductance, current–voltage [I-V] relations, and charge selectivity). However, the crystal structure was incomplete, most notably lacking the coordinates of the N-terminal methionine residue, which resides within the pore, and also lacking two cytosolic domains. To allow computational studies for comparison with the known channel properties, we completed the structure. Grand canonical Monte Carlo Brownian dynamics (GCMC/BD) simulations of the completed and the published Cx26 hemichannel crystal structure indicate that the pore is too narrow to permit significant ion flux. The GCMC/BD simulations predict marked inward current rectification and almost perfect anion selectivity, both inconsistent with known channel properties. The completed structure was refined by all-atom molecular dynamics (MD) simulations (220 ns total) in an explicit solvent and POPC membrane system. These MD simulations produced an equilibrated structure with a larger minimal pore diameter, which decreased the height of the permeation barrier formed by the N terminus. GCMC/BD simulations of the MD-equilibrated structure yielded more appropriate single-channel conductance and less anion/cation selectivity. However, the simulations much more closely matched experimentally determined I-V relations when the charge effects of specific co- and posttranslational modifications of Cx26 previously identified by mass spectrometry were incorporated. We conclude that the average equilibrated structure obtained after MD simulations more closely represents the open Cx26 hemichannel structure than does the crystal structure, and that co- and posttranslational modifications of Cx26 hemichannels are likely to play an important physiological role by defining the conductance and ion selectivity of Cx26 channels. Furthermore, the simulations and data suggest that experimentally observed heterogeneity in Cx26 I-V relations can be accounted for by variation in co- and posttranslational modifications

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Cannabis, Moral Entrepreneurship, and Stigma: Conflicting Narratives on the 26 May 2016 Toronto Police Raid on Cannabis Shops

On May 26, 2016, the police raided 43 cannabis dispensaries in Toronto, Canada, making 90 arrests. This article aims to describe the narrative of the responsible state agencies concerning the police raid and compare it to the narrative of those who opposed it, such as activists, as well as consumers and sellers of cannabis. While such concepts as moral entrepreneur, moral panic, and moral crusade have traditionally been used to study those in power, I will employ them to explore both the state narrative and ways in which counterclaims-makers resisted it. In order to do so, I will further develop the concept of moral entrepreneurship and its characteristics by relating it to studies of moral panics and social problems. This article will be guided by the following question: How did each party socially construct its cannabis narrative, and in what way can we use the concept of moral entrepreneurship to describe and analyze these narratives as social constructions? I have investigated the media coverage of the raid and ethnographically studied shops in Toronto in order to study the narratives. My findings show that both parties used a factual neutral style, as well as a dramatizing style. The later includes such typical crusading strategies as constructing victims and villains and presenting the image of a dystopian social world. In order to explain the use of these strategies, we will relate them to the shifting wider social and historical context and to the symbolic connotation of cannabis shops in Toronto in particular and in Canada as a whole

Doing/Undoing Stigma : The Moral Enterprise of Territorial Stigma

In this article I focus on stigma, and more specifically on territorial stigma in a Dutch suburb built in the 1970s. This publication is based on ethnographic fieldwork that lasted two and half years and which took place at the end of the 1980s. The data is reanalyzed in the light of recent developments in studies on stigma and territorial stigma, specifically how this is countered. I will use the conceptual pair—doing stigma and undoing stigma—to unpack stigma as a complex and dynamic process in which a diverse range of actors, such as inhabitants, civil servants and youth, are involved. The aim of this article is twofold: to describe and analyze the social construction of territorial stigma (doing stigma) of the neighborhood over a period of ten years and whether and how this stigma is countered (undoing stigma). This article highlights the agency of those targeted by stigma by paying attention to local narratives and using a multi-perspective ethnographic lens. The narratives show that stigma did not gain a master status because (1) the stigma producers were marginal in the social world of the targeted inhabitants and (2) it did not align with structural stigma (as in e.g., housing, health care, income, and education)