2,756 research outputs found

    Click, play and save: The iGamelan as a tool for music-culture sustainability

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    This article explores the potential for web-based interactive music resources to represent and sustain music-culture heritage via digital means. Our focus is the University of Otago's virtual Indonesian gamelan (iGamelan): an immersive online resource featuring interactive musical instruments, an audio-video gallery, and information archive. Designed in 2010-2011 for use within the tertiary education context, the iGamelan stands alone as an innovative learning/teaching tool, and also enhances real-life instructional sessions with the University's pelog/slendro Central Javanese gamelan. This article illuminates the pitfalls and achievements of the iGamelan project and, at a broader level, demonstrates how contemporary technology can help sustain active music-making cultures

    The function of endocytosis in Wnt signaling

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    This is the final version of the article. Available from Springer Verlag via the DOI in this record.Wnt growth factors regulate one of the most important signaling networks during development, tissue homeostasis and disease. Despite the biological importance of Wnt signaling, the mechanism of endocytosis during this process is ill described. Wnt molecules can act as paracrine signals, which are secreted from the producing cells and transported through neighboring tissue to activate signaling in target cells. Endocytosis of the ligand is important at several stages of action: One central function of endocytic trafficking in the Wnt pathway occurs in the source cell. Furthermore, the β-catenin-dependent Wnt ligands require endocytosis for signal activation and to regulate gene transcription in the responding cells. Alternatively, Wnt/β-catenin-independent signaling regulates endocytosis of cell adherence plaques to control cell migration. In this comparative review, we elucidate these three fundamental interconnected functions, which together regulate cellular fate and cellular behavior. Based on established hypotheses and recent findings, we develop a revised picture for the complex function of endocytosis in the Wnt signaling network.Funding was provided by Deutsche Forschungsgemeinschaft (Grant no. SCHO847-5) and the University of Exeter (GB) (LSI Start-up Grant)

    Warm HCN, C2H2, and CO in the disk of GV Tau

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    We present the first high-resolution, ground-based observations of HCN and C2H2 toward the T Tauri binary star system GV Tau. We detected strong absorption due to HCN nu_3 and weak C2H2 (nu_3 and nu_2 + (nu_4 + nu_5)^0_+) absorption toward the primary (GV Tau S) but not the infrared companion. We also report CO column densities and rotational temperatures, and present abundances relative to CO of HCN/CO ~0.6% and C2H2/CO ~1.2% and an upper limit for CH4/CO < 0.37% toward GV Tau S. Neither HCN nor C2H2 were detected toward the infrared companion and results suggest that abundances may differ between the two sources.Comment: 23 pages, 6 figures, accepted by Ap

    Variations in the price and quality of English grain, 1750-1914:Quantitative evidence and empirical implications

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    Interpretation of historic grain price data may be hazardous owing to systematic grain quality variation – both cross sectionally and over varying time horizons (intra-year, inter-year, long run). We use the English wheat market, 1750-1914, as an example to quantify this issue. First, we show that bushel weight approximates grain quality. Then we show that cross sectional and intra-year variation are substantial and problematic, generating erroneous inference regarding market integration. Long run variation is significant, due to sharply declining international quality differentials, and this impacts estimated cost of living changes. By contrast, inter-year variation is smaller and controlled for more easily

    The structure of molecular gas associated with NGC2264: wide-field 12CO and H2 imaging

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    We present wide-field, high-resolution imaging observations in 12CO 3-2 and H2 1-0 S(1) towards a ~1 square degree region of NGC2264. We identify 46 H2 emission objects, of which 35 are new discoveries. We characterize several cores as protostellar, reducing the previously observed ratio of prestellar/protostellar cores in the NGC2264 clusters. The length of H2 jets increases the previously reported spatial extent of the clusters. In each cluster, <0.5% of cloud material has been perturbed by outflow activity. A principal component analysis of the 12CO data suggests that turbulence is driven on scales >2.6 pc, which is larger than the extent of the outflows. We obtain an exponent alpha=0.74 for the size-linewidth relation, possibly due to the high surface density of NGC2264. In this very active, mixed-mass star forming region, our observations suggest that protostellar outflow activity is not injecting energy and momentum on a large enough scale to be the dominant source of turbulence.Comment: MNRAS accepte

    From top to bottom: Cell polarity in Hedgehog and Wnt trafficking.

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    This is the final version of the article. Available from the publisher via the DOI in this record.Spatial organization of membrane domains within cells and cells within tissues is key to the development of organisms and the maintenance of adult tissue. Cell polarization is crucial for correct cell-cell signalling, which, in turn, promotes cell differentiation and tissue patterning. However, the mechanisms linking internal cell polarity to intercellular signalling are just beginning to be unravelled. The Hedgehog (Hh) and Wnt pathways are major directors of development and their malfunction can cause severe disorders like cancer. Here we discuss parallel advances into understanding the mechanism of Hedgehog and Wnt signal dissemination and reception. We hypothesize that cell polarization of the signal-sending and signal-receiving cells is crucial for proper signal spreading and activation of the pathway and, thus, fundamental for development of multicellular organisms.SS and LB funding was provided by the University of Exeter, UK (LSI Start-up Grant awarded to SS). ACG and DSH are funded on a Young Investigator Grant (BFU2015-73609-JIN) to ACG from MINECO (Spain). DSH was also funded by a collaboration short-term EMBO fellowship. The authors would like to thank Isabel Guerrero (University of Madrid) for her respective valuable comments that helped improve the quality of the manuscript

    Characterizing precursors to stellar clusters with Herschel

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    Context. Despite their profound effect on the universe, the formation of massive stars and stellar clusters remains elusive. Recent advances in observing facilities and computing power have brought us closer to understanding this formation process. In the past decade, compelling evidence has emerged that suggests infrared dark clouds (IRDCs) may be precursors to stellar clusters. However, the usual method for identifying IRDCs is biased by the requirement that they are seen in absorption against background mid-IR emission, whereas dust continuum observations allow cold, dense pre-stellar-clusters to be identified anywhere. Aims: We aim to understand what dust temperatures and column densities characterize and distinguish IRDCs, to explore the population of dust continuum sources that are not IRDCs, and to roughly characterize the level of star formation activity in these dust continuum sources. Methods: We use Hi-GAL 70 to 500 mdatatoidentifydustcontinuumsourcesintheell=30degandell=59degHiGALsciencedemonstrationphase(SDP)fields,tocharacterizeandsubtracttheGalacticcirrusemission,andperformpixelbypixelmodifiedblackbodyfitsoncirrussubtractedHiGALsources.WeutilizearchivalSpitzerdatatoindicatethelevelofstarformingactivityineachpixel,frommidIRdarktomidIRbright.Results:WepresenttemperatureandcolumndensitymapsintheHiGALell=30degandell=59degSDPfields,aswellasarobustalgorithmforcirrussubtractionandsourceidentificationusingHiGALdata.WereportonthefractionofHiGALsourcepixelswhicharemidIRdark,midIRneutral,ormidIRbrightinbothfields.WefindsignificanttrendsincolumndensityandtemperaturebetweenmidIRdarkandmidIRbrightpixels;midIRdarkpixelsareabout10Kcolderandhaveafactorof2highercolumndensityonaveragethanmidIRbrightpixels.WefindthatHiGALdustcontinuumsourcesspanarangeofevolutionarystatesfrompretostarforming,andthatwarmersourcesareassociatedwithmorestarformationtracers.Additionally,thereisatrendofincreasingtemperaturewithtracertypefrommidIRdarkatthecoldest,tooutflow/masersourcesinthemiddle,andfinallyto8and24m data to identify dust continuum sources in the ell = 30deg and ell = 59deg Hi-GAL science demonstration phase (SDP) fields, to characterize and subtract the Galactic cirrus emission, and perform pixel-by-pixel modified blackbody fits on cirrus-subtracted Hi-GAL sources. We utilize archival Spitzer data to indicate the level of star-forming activity in each pixel, from mid-IR-dark to mid-IR-bright. Results: We present temperature and column density maps in the Hi-GAL ell = 30deg and ell = 59deg SDP fields, as well as a robust algorithm for cirrus subtraction and source identification using Hi-GAL data. We report on the fraction of Hi-GAL source pixels which are mid-IR-dark, mid-IR-neutral, or mid-IR-bright in both fields. We find significant trends in column density and temperature between mid-IR-dark and mid-IR-bright pixels; mid-IR-dark pixels are about 10 K colder and have a factor of 2 higher column density on average than mid-IR-bright pixels. We find that Hi-GAL dust continuum sources span a range of evolutionary states from pre- to star-forming, and that warmer sources are associated with more star formation tracers. Additionally, there is a trend of increasing temperature with tracer type from mid-IR-dark at the coldest, to outflow/maser sources in the middle, and finally to 8 and 24 m bright sources at the warmest. Finally, we identify five candidate IRDC-like sources on the far-side of the Galaxy. These are cold (20 K), high column density (N(H2_2) gt 1022^22 cm2^-2) clouds identified with Hi-GAL which, despite bright surrounding mid-IR emission, show little to no absorption at 8 $m. These are the first inner Galaxy far-side candidate IRDCs of which the authors are aware. Herschel in an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation by NASA.The FITS files discussed in the paper would be released publicly WITH the Hi-GAL data (on the Hi-GAL website) when the Hi-GAL data is released publicly.Peer reviewe

    Modification of Projected Velocity Power Spectra by Density Inhomogeneities in Compressible Supersonic Turbulence

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    (Modified) The scaling of velocity fluctuation, dv, as a function of spatial scale L in molecular clouds can be measured from size-linewidth relations, principal component analysis, or line centroid variation. Differing values of the power law index of the scaling relation dv = L^(g3D) in 3D are given by these different methods: the first two give g3D=0.5, while line centroid analysis gives g3D=0. This discrepancy has previously not been fully appreciated, as the variation of projected velocity line centroid fluctuations (dv_{lc} = L^(g2D)) is indeed described, in 2D, by g2D=0.5. However, if projection smoothing is accounted for, this implies that g3D=0. We suggest that a resolution of this discrepancy can be achieved by accounting for the effect of density inhomogeneity on the observed g2D obtained from velocity line centroid analysis. Numerical simulations of compressible turbulence are used to show that the effect of density inhomogeneity statistically reverses the effect of projection smoothing in the case of driven turbulence so that velocity line centroid analysis does indeed predict that g2D=g3D=0.5. Using our numerical results we can restore consistency between line centroid analysis, principal component analysis and size-linewidth relations, and we derive g3D=0.5, corresponding to shock-dominated (Burgers) turbulence. We find that this consistency requires that molecular clouds are continually driven on large scales or are only recently formed.Comment: 28 pages total, 20 figures, accepted for publication in Ap

    Air pollution, deprivation and health: Understanding relationships to add value to local air quality management policy and practice in Wales, UK

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    © The Author 2016. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. Background Air pollution exposure reduces life expectancy. Air pollution, deprivation and poor-health status combinations can create increased and disproportionate disease burdens. Problems and solutions are rarely considered in a broad public health context, but doing so can add value to air quality management efforts by reducing air pollution risks, impacts and inequalities. Methods An ecological study assessed small-area associations between air pollution (nitrogen dioxide and particulate matter), deprivation status and health outcomes in Wales, UK. Results Air pollution concentrations were highest in 'most' deprived areas. When considered separately, deprivation-health associations were stronger than air pollution-health associations. Considered simultaneously, air pollution added to deprivation-health associations; interactions between air pollution and deprivation modified and strengthened associations with all-cause and respiratory disease mortality, especially in 'most' deprived areas where most-vulnerable people lived and where health needs were greatest. Conclusion There is a need to reduce air pollution-related risks for all. However, it is also the case that greater health gains can result from considering local air pollution problems and solutions in the context of wider health-determinants and acting on a better understanding of relationships. Informed and co-ordinated air pollution mitigation and public health action in high deprivation and pollution areas can reduce risks and inequalities. To achieve this, greater public health integration and collaboration in local air quality management policy and practice is needed

    Photodetachment study of He^- quartet resonances below the He(n=3) thresholds

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    The photodetachment cross section of He^- has been measured in the photon energy range 2.9 eV to 3.3 eV in order to investigate doubly excited states. Measurements were made channel specific by selectively detecting the residual He atoms left in a particular excited state following detachment. Three Feshbach resonances were found in the He(1s2p ^3P)+e^-(epsilon p) partial cross section: a ^4S resonance below the He(1s3s ^3S) threshold and two ^4P resonances below the He(1s3p ^3P) threshold. The measured energies of these doubly excited states are 2.959260(6) eV, 3.072(7) eV and 3.26487(4) eV. The corresponding widths are found to be 0.20(2) meV, 50(5) meV and 0.61(5) meV. The measured energies agree well with recent theoretical predictions for the 1s3s4s ^4S, 1s3p^2 ^4P and 1s3p4p ^4P states, respectively, but the widths deviate noticeably from calculations for 1s3p^2 ^4P and 1s3p4p ^4P states.Comment: 10 pages, 3 figures, LaTeX2e scrartcl, amsmath. Accepted by Journal of Physics B; minor changes after referee repor
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