« Enfoncé, Lanson ! », ou comment le surréalisme a changé l’histoire littéraire

Au début des années 1920, Louis Aragon, André Breton, Paul Eluard, Philippe Soupault et quelques autres fondent, sur les ruines d’un ordre mondial ébranlé par le conflit qui vient de s’achever, un mouvement appelé à dominer le xxe siècle. Dans la vaste entreprise de remise en cause culturelle et politique à laquelle ils s’attellent, l’histoire littéraire n’est pas épargnée – elle est même l’un des premiers terrains d’expérimentation de ceux qui ne se nomment pas encore surréalistes et qui ten..

Parcours 5. Une décennie de mise en ligne des collections numérisées vue à travers l’œil de S.I.Lex

Quand il crée S.I.Lex en 2009, Lionel Maurel est depuis quelques années en poste à la BnF – que je viens alors de rejoindre. Nous travaillerons ensemble peu après, en imaginant à quatre mains la stratégie de présence de Gallica sur les réseaux sociaux – l’occasion pour moi d’apprécier sa fine connaissance du monde des bibliothèques comme du web social et de ses enjeux, mais aussi son humour, son intransigeance, son goût du débat et du jeu. Le regard acéré porté par S.I.Lex sur les choix strat..

Phylogeography, Risk Factors and Genetic History of Hepatitis C Virus in Gabon, Central Africa

BACKGROUND: The epidemiological and molecular characteristics of hepatitis C virus (HCV) infection in the general population have been poorly investigated in Africa. The aim of this study was to determine the prevalence, genotype distribution and epidemic history of HCV in the Gabonese general population. METHODS/PRINCIPAL FINDINGS: A total of 4042 sera collected from adults in 220 villages in all nine administrative areas of the country were screened for antibodies to HCV. HCV NS5B region sequencing was performed for molecular characterization and population genetic analyses. Of 4042 tested sera, 455 (11.2%) were positive. The seroprevalence of HCV varied significantly by administrative area, with the highest rate in Ogooue-Lolo province (20.4%) and the lowest in Ogooue-Maritine province (3.7%). History of parenteral injections, past hospital admission and age over 55 years were independent risk factors for HCV infection (p<0.0001). Phylogenetic analyses showed that 91.9% of the strains were genotype 4 (HCV-4), 5.7% genotype 1 and 2.2% genotype 2. HCV-4 strains were highly heterogeneous, with more than eight subtypes; subtype 4e predominated (57.3%). Coalescence analyses indicated that subtype 4e was the oldest, with an estimated most recent common ancestor of 1702 [95% CI, 1418-1884]. The epidemic profile indicated that it spread exponentially during the first part of the 20th century, probably by iatrogenic transmission. CONCLUSIONS/SIGNIFICANCE: These results confirm the endemicity of HCV subtype 4e in Gabon and show that its spread is due to a cohort effect, with previous, possibly iatrogenic events. More extensive epidemiological studies are needed to better characterize the route of transmission and the dissemination of HCV in Gabon

A 50 pc Scale View of Star Formation Efficiency across NGC 628

Star formation is a multi-scale process that requires tracing cloud formation and stellar feedback within the local (≲kpc) and global galaxy environment. We present first results from two large observing programs on the Atacama Large Millimeter/submillimeter Array (ALMA)and the Very Large Telescope/Multi Unit Spectroscopic Explorer(VLT/MUSE), mapping cloud scales (1″ = 47 pc) in both molecular gas and star-forming tracers across 90 kpc2 of the central disk of NGC 628 to probe the physics of star formation. Systematic spatial offsets between molecular clouds and H ii regions illustrate the time evolution of star-forming regions. Using uniform sampling of both maps on 50-500 pc scales, we infer molecular gas depletion times of 1-3 Gyr, but also find that the increase of scatter in the star formation relation on small scales is consistent with gas and H ii regions being only weakly correlated at the cloud (50 pc) scale. This implies a short overlap phase for molecular clouds and H ii regions, which we test by directly matching our catalog of 1502 H ii regions and 738 GMCs. We uncover only 74 objects in the overlap phase, and we find depletion times >1 Gyr, significantly longer than previously reported for individual star-forming clouds in the Milky Way. Finally, we find no clear trends that relate variations in the depletion time observed on 500 pc scales to physical drivers (metallicity, molecular and stellar-mass surface density, molecular gas boundedness) on 50 pc scales.We thank the referee for helpful comments that improved this work. K.K. gratefully acknowledges support from grant KR 4598/1-2 from the German Research Foundation (DFG) Priority Program 1573. J.M.D.K. and M.C. gratefully acknowledge funding from the DFG in the form of an Emmy Noether Research Group (grant No. KR4801/1-1). J.M.D.K. gratefully acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme via the ERC Starting Grant MUSTANG (grant agreement No. 714907). B.G. gratefully acknowledges the support of the Australian Research Council as the recipient of a Future Fellowship (FT140101202). F.B. acknowledges funding from the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement No. 726384—EMPIRE). G.B. is supported by CONICYT/ FONDECYT, Programa de Iniciación, Folio 11150220. A.H. acknowledges support from the Centre National d’Etudes Spatiales (CNES). E.R. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada (NSERC), funding reference No. RGPIN-2017-03987. R.M. and E.S. acknowledge funding from the ERC under the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement No. 694343). J.P. acknowledges support by the Programme National “Physique et Chimie du Milieu Interstellaire”(PCMI) of CNRS/INSU with INC/INP co-funded by CEA and CNES

Integrin Alpha 8 Recessive Mutations Are Responsible for Bilateral Renal Agenesis in Humans

Renal hypodysplasia (RHD) is a heterogeneous condition encompassing a spectrum of kidney development defects including renal agenesis, hypoplasia, and (cystic) dysplasia. Heterozygous mutations of several genes have been identified as genetic causes of RHD with various severity. However, these genes and mutations are not associated with bilateral renal agenesis, except for RET mutations, which could be involved in a few cases. The pathophysiological mechanisms leading to total absence of kidney development thus remain largely elusive. By using a whole-exome sequencing approach in families with several fetuses with bilateral renal agenesis, we identified recessive mutations in the integrin α8-encoding gene ITGA8 in two families. Itga8 homozygous knockout in mice is known to result in absence of kidney development. We provide evidence of a damaging effect of the human ITGA8 mutations. These results demonstrate that mutations of ITGA8 are a genetic cause of bilateral renal agenesis and that, at least in some cases, bilateral renal agenesis is an autosomal-recessive disease

Cloud-Scale Molecular Gas Properties in 15 Nearby Galaxies

We measure the velocity dispersion, $\sigma$, and surface density, $\Sigma$, of the molecular gas in nearby galaxies from CO spectral line cubes with spatial resolution $45$-$120$ pc, matched to the size of individual giant molecular clouds. Combining $11$ galaxies from the PHANGS-ALMA survey with $4$ targets from the literature, we characterize ${\sim}30,000$ independent sightlines where CO is detected at good significance. $\Sigma$ and $\sigma$ show a strong positive correlation, with the best-fit power law slope close to the expected value for resolved, self-gravitating clouds. This indicates only weak variation in the virial parameter $\alpha_\mathrm{vir}\propto\sigma^2/\Sigma$, which is ${\sim}1.5$-$3.0$ for most galaxies. We do, however, observe enormous variation in the internal turbulent pressure $P_\mathrm{turb}\propto\Sigma\,\sigma^2$, which spans ${\sim}5\rm\;dex$ across our sample. We find $\Sigma$, $\sigma$, and $P_\mathrm{turb}$ to be systematically larger in more massive galaxies. The same quantities appear enhanced in the central kpc of strongly barred galaxies relative to their disks. Based on sensitive maps of M31 and M33, the slope of the $\sigma$-$\Sigma$ relation flattens at $\Sigma\lesssim10\rm\;M_\odot\,pc^{-2}$, leading to high $\sigma$ for a given $\Sigma$ and high apparent $\alpha_\mathrm{vir}$. This echoes results found in the Milky Way, and likely originates from a combination of lower beam filling factors and a stronger influence of local environment on the dynamical state of molecular gas in the low density regime.Comment: Accepted for publication in ApJ. 45 pages, 11 figures, 8 tables, 4 Appendices; key results summarized in Figure 10. Machine-readable table can be downloaded at http://www.astronomy.ohio-state.edu/~sun.1608/datafile3.txt prior to publication. For a brief video describing the main results of this paper, please see https://www.youtube.com/watch?v=-_eL7t1PVq8&

Surveying the Whirlpool at Arcseconds with NOEMA (SWAN)- I. Mapping the HCN and N2_2H+^+ 3mm lines

We present the first results from "Surveying the Whirlpool at Arcseconds with NOEMA" (SWAN), an IRAM Northern Extended Millimetre Array (NOEMA)+30m large program that maps emission from several molecular lines at 90 and 110 GHz in the iconic nearby grand-design spiral galaxy M~51 at cloud-scale resolution ($\sim$3\arcsec=125\,pc). As part of this work, we have obtained the first sensitive cloud-scale map of N$_2$H$^+$(1-0) of the inner $\sim5\,\times 7\,$kpc of a normal star-forming galaxy, which we compare to HCN(1-0) and CO(1-0) emission to test their ability in tracing dense, star-forming gas. The average N$_2$H$^+$-to-HCN line ratio of our total FoV is $0.20\pm0.09$, with strong regional variations of a factor of $\gtrsim 2$ throughout the disk, including the south-western spiral arm and the center. The central $\sim1\,$kpc exhibits elevated HCN emission compared to N$_2$H$^+$, probably caused by AGN-driven excitation effects. We find that HCN and N$_2$H$^+$ are strongly super-linearily correlated in intensity ($\rho_\mathrm{Sp}\sim 0.8$), with an average scatter of $\sim0.14\,$dex over a span of $\gtrsim 1.5\,$dex in intensity. When excluding the central region, the data is best described by a power-law of exponent $1.2$, indicating that there is more N$_2$H$^+$ per unit HCN in brighter regions. Our observations demonstrate that the HCN-to-CO line ratio is a sensitive tracer of gas density in agreement with findings of recent Galactic studies which utilize N$_2$H$^+$. The peculiar line ratios present near the AGN and the scatter of the power-law fit in the disk suggest that in addition to a first-order correlation with gas density, second-order physics (such as optical depth, gas temperature) or chemistry (abundance variations) are encoded in the N$_2$H$^+$/CO, HCN/CO and N$_2$H$^+$/HCN ratios.Comment: Accepted for publication in A&A. 6 pages, 3 figures (+ Appendix 4 pages, 2 figures