Attenuation modified by DIG and dust as seen in M31

The spatial distribution of dust in galaxies affects the global attenuation, and hence inferred properties, of galaxies. We trace the spatial distribution of dust in five fields (at 0.6-0.9 kpc scale) of M31 by comparing optical attenuation with the total dust mass distribution. We measure the attenuation from the Balmer decrement using Integral Field Spectroscopy and the dust mass from Herschel far-IR observations. Our results show that M31's dust attenuation closely follows a foreground screen model, contrary to what was previously found in other nearby galaxies. By smoothing the M31 data we find that spatial resolution is not the cause for this difference. Based on the emission line ratios and two simple models, we conclude that previous models of dust/gas geometry need to include a weakly or non-attenuated diffuse ionized gas (DIG) component. Due to the variation of dust and DIG scale heights with galactic radius, we conclude that different locations in galaxies will have different vertical distributions of gas and dust and therefore different measured attenuation. The difference between our result in M31 with that found in other nearby galaxies can be explained by our fields in M31 lying at larger galactic radii than the previous studies that focused on the centres of galaxies.Comment: 20 pages, 13 figures, ApJ accepted and in pres

The EMPIRE Survey: Systematic Variations in the Dense Gas Fraction and Star Formation Efficiency from Full-Disk Mapping of M51

We present the first results from the EMPIRE survey, an IRAM large program that is mapping tracers of high density molecular gas across the disks of nine nearby star-forming galaxies. Here, we present new maps of the 3-mm transitions of HCN, HCO+, and HNC across the whole disk of our pilot target, M51. As expected, dense gas correlates with tracers of recent star formation, filling the "luminosity gap" between Galactic cores and whole galaxies. In detail, we show that both the fraction of gas that is dense, f_dense traced by HCN/CO, and the rate at which dense gas forms stars, SFE_dense traced by IR/HCN, depend on environment in the galaxy. The sense of the dependence is that high surface density, high molecular gas fraction regions of the galaxy show high dense gas fractions and low dense gas star formation efficiencies. This agrees with recent results for individual pointings by Usero et al. 2015 but using unbiased whole-galaxy maps. It also agrees qualitatively with the behavior observed contrasting our own Solar Neighborhood with the central regions of the Milky Way. The sense of the trends can be explained if the dense gas fraction tracks interstellar pressure but star formation occurs only in regions of high density contrast.Comment: 7 pages, 5 figures, ApJL accepte

Resisting “Dirty Business”: Report from the Field of Social Exclusion in the Czech Republic

Before 1989-90, all housing in the Czech Republic de facto owned by the state was social in some sense. After 1990, rather than promoting social housing, the state largely decentralized, deregulated and privatized it, creating fertile ground for “a market of the poor”, and opening it to the predatory practices of the real estate entrepreneurs

American dream, Humboldtian nightmare: Reflections on the remodelled values of a neoliberalized academia

While universities now lie between two philosophical poles – idealism and utilitarianism – the Humboldtian ideal primarily serves to give a humanist glaze to a technocratic discourse. Regardless of its autonomy on paper, the University does not control its finances. This guise of autonomy has set a double authoritarian heteronomy of the university: from increased administrative supervision and from market control. While the current debate is strongly permeated by the idea that we should simultaneously compete with and copy the model of elite US universities, this article presents reflections on how detached from Humboldtian ideals we now are, explores the consequences of that transformational logic and encourages debate through critical distance

Epigenetic changes in histone acetylation underpin resistance to the topoisomerase I inhibitor irinotecan.

The topoisomerase I (TOP1) inhibitor irinotecan triggers cell death by trapping TOP1 on DNA, generating cytotoxic protein-linked DNA breaks (PDBs). Despite its wide application in a variety of solid tumors, the mechanisms of cancer cell resistance to irinotecan remains poorly understood. Here, we generated colorectal cancer (CRC) cell models for irinotecan resistance and report that resistance is neither due to downregulation of the main cellular target of irinotecan TOP1 nor upregulation of the key TOP1 PDB repair factor TDP1. Instead, the faster repair of PDBs underlies resistance, which is associated with perturbed histone H4K16 acetylation. Subsequent treatment of irinotecan-resistant, but not parental, CRC cells with histone deacetylase (HDAC) inhibitors can effectively overcome resistance. Immunohistochemical analyses of CRC tissues further corroborate the importance of histone H4K16 acetylation in CRC. Finally, the resistant clones exhibit cross-resistance with oxaliplatin but not with ionising radiation or 5-fluoruracil, suggesting that the latter two could be employed following loss of irinotecan response. These findings identify perturbed chromatin acetylation in irinotecan resistance and establish HDAC inhibitors as potential therapeutic means to overcome resistance

Taking the gilt off the gingerbread: Reverberations of the metrics cult (ure) on the theory of social representations

There is a prevailing view that the university is transforming into an economic agent, with broad and troubling implications for scholars’ future prospects. While some studies were devoted to the academic world considering its organizational approaches centered on the rationalization of universities, it is important to devote some focus to the ways these changes translate in specific cases of universities’ knowledge production. It is to the description of a particular case of theory diffusion necessarily embedded within the academic world it emerged out of, developed in and still matures in, that this work will be giving priority—the case of the Theory of Social Representations. Since Serge Moscovici’s 1961 seminal study of social representations (Moscovici, 1961), the theory was developed through different theoretical and methodological approaches, conceptualized through various models, and most importantly widely adopted all over the world by scholars of diverse disciplinary perspectives working in a variety of thematic fields. But the theoretical polarity between the transdisciplinary Theory of Social Representations and “mainstream Social Psychology” is reflected through an ongoing world debate, although largely held within the circles of European social psychologists. The stakes of these internal debates are high: an integral redefinition of the discipline, of social sciences, and of knowledge diffusion. Even though the theoretical core of Moscovici’s theory is an undoubtedly valuable contribution to the social sciences, its methodological incompatibilities with “what sells” leaves it structurally ostracized, and its potential unfulfilled. This article examines the interplay of European tradition, its disciplinary legacy, and market-oriented trends which have undoubtedly impacted the developmental paths the Theory has followed

Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

The macrozoobenthos of Mejillones Bay (23°S; Humboldt Current) was quantitatively investigated over a 7-year period from austral summer 1995/1996 to winter 2002. About 78 van Veen grab samples taken at six stations (5, 10, 20 m depth) provided the basis for the analysis of the distribution of 60 species and 28 families of benthic invertebrates, as well as of their abundance and biomass. Mean abundance (2,119 individuals m-2) was in the same order compared to a previous investigation; mean biomass (966 g formalin wet mass m-2), however, exceeded prior estimations mainly due to the dominance of the bivalve Aulacomya ater. About 43% of the taxa inhabited the complete depth range. Mean taxonomic Shannon diversity (H', Log e) was 1.54 ± 0.58 with a maximum at 20 m (1.95 ± 0.33); evenness increased with depth. The fauna was numerically dominated by carnivorous gastropods, polychaetes and crustaceans (48%). About 15% of the species were suspensivorous, 13% sedimentivorous, 11% detritivorous, 7% omnivorous and 6% herbivorous. Cluster analyses showed a significant difference between the shallow and the deeper stations. Gammarid amphipods and the polychaete family Nephtyidae characterized the 5-mzone, the molluscs Aulacomya ater, Mitrella unifasciata and gammarids the intermediate zone, while the gastropod Nassarius gayi and the polychaete family Nereidae were most prominent at the deeper stations. The communities of the three depth zones did not appear to be limited by hypoxia during non-El Niño conditions. Therefore, no typical change in community structure occurred during El Niño 1997–1998, in contrast to what was observed for deeper faunal assemblages and hypoxic bays elsewhere in the coastal Humboldt Current system