4,698 research outputs found

    Pax3 synergizes with Gli2 and Zic1 in transactivating the Myf5 epaxial somite enhancer

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    AbstractBoth Glis, the downstream effectors of hedgehog signaling, and Zic transcription factors are required for Myf5 expression in the epaxial somite. Here we demonstrate a novel synergistic interaction between members of both families and Pax3, a paired-domain transcription factor that is essential for both myogenesis and neural crest development. We show that Pax3 synergizes with both Gli2 and Zic1 in transactivating the Myf5 epaxial somite (ES) enhancer in concert with the Myf5 promoter. This synergy is dependent on conserved functional domains of the proteins, as well as on a novel homeodomain motif in the Myf5 promoter and the essential Gli motif in the ES enhancer. Importantly, overexpression of Zic1 and Pax3 in the 10T1/2 mesodermal cell model results in enrichment of these factors at the endogenous Myf5 locus and induction of Myf5 expression. In our previous work, we showed that by enhancing nuclear translocation of Gli factors, Zics provide spatiotemporal patterning for Gli family members in the epaxial induction of Myf5 expression. Our current study indicates a complementary mechanism in which association with DNA-bound Pax3 strengthens the ability of both Zic1 and Gli2 to transactivate Myf5 in the epaxial somite

    The role of corporate social responsibility in the wine industry: The case study of veneto and friuli venezia giulia

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    This study aimed to investigate the awareness of Corporate Social Responsibility (CSR) among wineries located in the Italian regions of Veneto and Friuli Venezia Giulia (FVG) (1), (2) the obstacles (3) and market drivers of its implementation (4), the practices and range of actions that are concretely implemented in the field of CSR (5), the implications that this management approach can have on company performance (6), and the communication tools used. The methodology adopted is based on a qualitative approach integrated with quantitative measures. In total, 28 wineries participated in the study. The results show that all of the wineries were aware of the importance of implementing CSR, although they mainly refer to environmental issues. Sponsorship in fair trade activities is considered the most relevant market driver, while Italian consumers are generally perceived as not particularly interested in sustainable wine production. The practices implemented are mainly focused on reducing environmental impact. Interesting insights have emerged from this study, such as an unusual disparity between theoretical knowledge and practical implementation of socially responsible activities, a tendency to adapt the entrepreneurial style towards CSR, as well as a fundamental willingness to implement good practices that go beyond the legal requirements currently in force

    Predicting the economic impact of an Invasive species on an Ecosystem service

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    Quantifying the impact of alien invasive species on ecosystem services is an essential step in developing effective practices and policy for invasive species management. Here we develop a stochastic bioeconomic model that enables the economic impact of an invasive pest to be estimated before its arrival, based on relatively poorly specified ecological and economic parameters. We developed the model by using a hypothetical invasion of the varroa bee mite (Varroa destructor) into Australia and the negative flow-on effects that it would have on pollination by reducing honey bee populations, giving rise to a loss of pollination services, reduced crop yields, and additional production costs. If the mite were to continue to be prevented from entering the country over the next 30 years, we estimate that the economic costs avoided would be US16.438.8million(Aus16.4-38.8 million (Aus21.3-50.5 million) per year. We suggest that current invasion response funding arrangements in Australia, which do not acknowledge these avoided damages, require amendment

    The evolution of the X-ray luminosity functions of unabsorbed and absorbed AGNs out to z~5

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    We present new measurements of the evolution of the X-ray luminosity functions (XLFs) of unabsorbed and absorbed Active Galactic Nuclei (AGNs) out to z~5. We construct samples containing 2957 sources detected at hard (2-7 keV) X-ray energies and 4351 sources detected at soft (0.5-2 keV) energies from a compilation of Chandra surveys supplemented by wide-area surveys from ASCA} and ROSAT. We consider the hard and soft X-ray samples separately and find that the XLF based on either (initially neglecting absorption effects) is best described by a new flexible model parametrization where the break luminosity, normalization and faint-end slope all evolve with redshift. We then incorporate absorption effects, separately modelling the evolution of the XLFs of unabsorbed (20<logNH<2220<\log N_\mathrm{H}<22) and absorbed (22<logNH<2422<\log N_\mathrm{H}<24) AGNs, seeking a model that can reconcile both the hard- and soft-band samples. We find that the absorbed AGN XLF has a lower break luminosity, a higher normalization, and a steeper faint-end slope than the unabsorbed AGN XLF out to z~2. Hence, absorbed AGNs dominate at low luminosities, with the absorbed fraction falling rapidly as luminosity increases. Both XLFs undergo strong luminosity evolution which shifts the transition in the absorbed fraction to higher luminosities at higher redshifts. The evolution in the shape of the total XLF is primarily driven by the changing mix of unabsorbed and absorbed populations.Comment: 36 pages, 20 figures, 11 tables. A casual reader is directed to figures 7, 8, 9 and 20. Updated to version accepted for publication in MNRA

    The MOSDEF survey: a stellar mass-SFR-metallicity relation exists at z2.3z\sim2.3

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    We investigate the nature of the relation among stellar mass, star-formation rate, and gas-phase metallicity (the M_*-SFR-Z relation) at high redshifts using a sample of 260 star-forming galaxies at z2.3z\sim2.3 from the MOSDEF survey. We present an analysis of the high-redshift M_*-SFR-Z relation based on several emission-line ratios for the first time. We show that a M_*-SFR-Z relation clearly exists at z2.3z\sim2.3. The strength of this relation is similar to predictions from cosmological hydrodynamical simulations. By performing a direct comparison of stacks of z0z\sim0 and z2.3z\sim2.3 galaxies, we find that z2.3z\sim2.3 galaxies have 0.1\sim0.1 dex lower metallicity at fixed M_* and SFR. In the context of chemical evolution models, this evolution of the M_*-SFR-Z relation suggests an increase with redshift of the mass-loading factor at fixed M_*, as well as a decrease in the metallicity of infalling gas that is likely due to a lower importance of gas recycling relative to accretion from the intergalactic medium at high redshifts. Performing this analysis simultaneously with multiple metallicity-sensitive line ratios allows us to rule out the evolution in physical conditions (e.g., N/O ratio, ionization parameter, and hardness of the ionizing spectrum) at fixed metallicity as the source of the observed trends with redshift and with SFR at fixed M_* at z2.3z\sim2.3. While this study highlights the promise of performing high-order tests of chemical evolution models at high redshifts, detailed quantitative comparisons ultimately await a full understanding of the evolution of metallicity calibrations with redshift.Comment: 19 pages, 8 figures, accepted to Ap

    The MOSDEF Survey: Kinematic and Structural Evolution of Star-Forming Galaxies at 1.4z3.81.4\leq z\leq 3.8

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    We present ionized gas kinematics for 681 galaxies at z1.43.8z\sim 1.4-3.8 from the MOSFIRE Deep Evolution Field survey, measured using models which account for random galaxy-slit misalignments together with structural parameters derived from CANDELS Hubble Space Telescope (HST) imaging. Kinematics and sizes are used to derive dynamical masses. Baryonic masses are estimated from stellar masses and inferred gas masses from dust-corrected star formation rates (SFRs) and the Kennicutt-Schmidt relation. We measure resolved rotation for 105 galaxies. For the remaining 576 galaxies we use models based on HST imaging structural parameters together with integrated velocity dispersions and baryonic masses to statistically constrain the median ratio of intrinsic ordered to disordered motion, V/σV,0V/\sigma_{V,0}. We find that V/σV,0V/\sigma_{V,0} increases with increasing stellar mass and decreasing specific SFR (sSFR). These trends may reflect marginal disk stability, where systems with higher gas fractions have thicker disks. For galaxies with detected rotation we assess trends between their kinematics and mass, sSFR, and baryon surface density (Σbar,e\Sigma_{\mathrm{bar},e}). Intrinsic dispersion correlates most with Σbar,e\Sigma_{\mathrm{bar},e} and velocity correlates most with mass. By comparing dynamical and baryonic masses, we find that galaxies at z1.43.8z\sim 1.4-3.8 are baryon dominated within their effective radii (RER_E), with Mdyn/Mbaryon increasing over time. The inferred baryon fractions within RER_E, fbarf_{\mathrm{bar}}, decrease over time, even at fixed mass, size, or surface density. At fixed redshift, fbarf_{\mathrm{bar}} does not appear to vary with stellar mass but increases with decreasing RER_E and increasing Σbar,e\Sigma_{\mathrm{bar},e}. For galaxies at z2z\geq2, the median inferred baryon fractions generally exceed 100%. We discuss possible explanations and future avenues to resolve this tension.Comment: Accepted to ApJ. Added Figure 9, corrected sample size (main results unchanged). 28 pages, 13 figure

    SHARDS: Constraints on the dust attenuation law of star-forming galaxies at z~2

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    We make use of SHARDS, an ultra-deep (<26.5AB) galaxy survey that provides optical photo-spectra at resolution R~50, via medium band filters (FWHM~150A). This dataset is combined with ancillary optical and NIR fluxes to constrain the dust attenuation law in the rest-frame NUV region of star-forming galaxies within the redshift window 1.5<z<3. We focus on the NUV bump strength (B) and the total-to-selective extinction ratio (Rv), targeting a sample of 1,753 galaxies. By comparing the data with a set of population synthesis models coupled to a parametric dust attenuation law, we constrain Rv and B, as well as the colour excess, E(B-V). We find a correlation between Rv and B, that can be interpreted either as a result of the grain size distribution, or a variation of the dust geometry among galaxies. According to the former, small dust grains are associated with a stronger NUV bump. The latter would lead to a range of clumpiness in the distribution of dust within the interstellar medium of star-forming galaxies. The observed wide range of NUV bump strengths can lead to a systematic in the interpretation of the UV slope (β\beta) typically used to characterize the dust content. In this study we quantify these variations, concluding that the effects are Δβ\Delta\beta~0.4.Comment: 13 pages, 11+2 figures, 3 tables. MNRAS, in pres
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