114 research outputs found

    Assessment of N mineralization and leaching in soil using a new in-situ incubation method

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    RAMIRAN International ConferenceTowards sustainable soil management, the application of organic residues to the soil has to be based on criteria sustained by experimental studies. Several methods for estimating the amount of N that mineralizes from landapplied organic residues can be used but laboratory incubations has been the main methodology used due to several advantages related to practical and economical aspects (Qafoku et al., 2001). However, this type of methodology is performed under controlled temperature and moisture content, at optimal conditions for the mineralization process, limiting the extrapolation of laboratory derived values to the field conditions (Hanselman et al., 2004). Since N mineralization process can be affected by the dynamic of these factors, several authors consider field incubations as a more realistic method to assess N mineralization (Subler et al., 1995; Halselman et al., 2004). Nevertheless, the quality of the results obtained depends on the type of reactor devices used for measuring N mineralization under these conditions. In fact, various reactors devices described in the specific literature, like buried bags (Eno, 1960) or covered cylinders (Raison et al., 1987), reveal some disadvantages or limitations in monitoring N mineralization in field conditions. More recently, refining reactor devices, by introducing exchange resins, promoted a more sensible indicator comparatively to other methods since temperature, moisture content and aeration inside the containerized soil are close to undisturbed soil (Halselman et al., 2004). Considering that resin-trap incubation is the most promising in-situ technology in measuring nitrogen net mineralization rates from organic soil amendments, the aim of the present study is to evaluate the quality of the results obtained by using a new in-situ incubation device for the determination of N mineralization kinetics in the soil as well as the potential of nitrogen leaching as a potential alternative use in field studies of N mineralization kinetics from organic residues applied to soils

    Prospective evaluation of glutamine and phospholipids levels in first degree relatives of patients with Type 1 Diabetes from a multiethnic population

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    A dysregulation in the metabolism of lipids may be an early marker of autoimmunity in Type 1 Diabetes (T1D). It would be of general importance to identify metabolic patterns that would predict the risk for T1D later in life. The aim of this study was to perform a prospective evaluation of glutamine and phospholipids levels in Brazilian first degree relatives (FDR) of patients with T1D in a mean interval of 5 years

    SEDIGISM-ATLASGAL: Dense Gas Fraction and Star Formation Efficiency Across the Galactic Disk

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    By combining two surveys covering a large fraction of the molecular material in the Galactic disk we investigate the role the spiral arms play in the star formation process. We have matched clumps identified by ATLASGAL with their parental GMCs as identified by SEDIGISM, and use these giant molecular cloud (GMC) masses, the bolometric luminosities, and integrated clump masses obtained in a concurrent paper to estimate the dense gas fractions (DGFgmc=∑Mclump/MgmcDGF_{gmc} = ∑M_{clump}/M_{gmc}) and the instantaneous star forming efficiencies (i.e., SFEgmc=∑Lclump/MgmcSFE_{gmc} = ∑L_{clump}/M_{gmc}). We find that the molecular material associated with ATLASGAL clumps is concentrated in the spiral arms (∼60 per cent found within ±10 km s−1^{−1} of an arm). We have searched for variations in the values of these physical parameters with respect to their proximity to the spiral arms, but find no evidence for any enhancement that might be attributable to the spiral arms. The combined results from a number of similar studies based on different surveys indicate that, while spiral-arm location plays a role in cloud formation and HI to H2_2 conversion, the subsequent star formation processes appear to depend more on local environment effects. This leads us to conclude that the enhanced star formation activity seen towards the spiral arms is the result of source crowding rather than the consequence of a any physical process

    The Drivers of Income Inequality in Rich Countries

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    Rising income inequality has recently come centre-stage as a core societal concern for rich countries. The diagnosis of the forces driving inequality upwards and their relative importance remains hotly contested, notably with respect to the roles of globalization versus technology and of market forces versus institutions and policy choices. This survey provides a critical review and synthesis of recent research. The focus is on income inequality across the entire distribution, rather than only on what has been happening at the very top. We pay particular attention to including what has been learned from the analysis of micro-data, to ensuring that the coverage is not unduly US-centric, and to analyses of the interrelations between the different drivers of inequality. The marked differences in inequality trends across countries and time-periods reflect how global economic forces such as globalisation and technological change have interacted with differing national contexts and institutions. Major analytical challenges stand in the way of a consensus emerging on the relative importance of different drivers in how income inequality has evolved in recent decades
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