1,743 research outputs found
Bank risk taking and liquidity creation following regulatory interventions and capital support
During times of bank distress, authorities often engage in regulatory interventions and provide capital support to reduce bank risk taking. An unintended effect of such actions may be a reduction in bank liquidity creation, with possible adverse consequences for the economy as a whole. This paper tests hypotheses regarding the effects of regulatory interventions and capital support on bank risk taking and liquidity creation using a unique dataset over the period 1999-2009. We find that both types of actions are generally associated with statistically significant reductions in risk taking and liquidity creation in the short run and long run. While the effects of regulatory interventions are also economically significant, the effects of capital support are only economically significant in the long run. Thus, both types of actions have important intended and unintended consequences with implications for policymakers.risk taking;liquidity creation;bank distress;regulatory interventions;capital support
ISO spectroscopy of circumstellar dust in 14 Herbig Ae/Be systems: towards an understanding of dust processing
We present Infrared Space Observatory (ISO) spectra of fourteen isolated
Herbig Ae/Be (HAEBE) stars, to study the characteristics of their circumstellar
dust. These spectra show large star-to-star differences, in the emission
features of both carbon-rich and oxygen-rich dust grains. The IR spectra were
combined with photometric data ranging from the UV through the optical into the
sub-mm region. We defined two key groups, based upon the spectral shape of the
infrared region. The derived results can be summarized as follows: (1) the
continuum of the IR to sub-mm region of all stars can be reconstructed by the
sum of a power-law and a cool component, which can be represented by a black
body. Possible locations for these components are an optically thick,
geometrically thin disc (power-law component) and an optically thin flared
region (black body); (2) all stars have a substantial amount of cold dust
around them, independent of the amount of mid-IR excess they show; (3) also the
near-IR excess is unrelated to the mid-IR excess, indicating different
composition/location of the emitting material; (4) remarkably, some sources
lack the silicate bands; (5) apart from amorphous silicates, we find evidence
for crystalline silicates in several stars, some of which are new detections;
(6) PAH bands are present in at least 50% of our sample, and their appearance
is slightly different from PAHs in the ISM; (7) PAH bands are, with one
exception, not present in sources which only show a power-law continuum in the
IR; their presence is unrelated to the presence of the silicate bands; (8) the
dust in HAEBE stars shows strong evidence for coagulation; this dust processing
is unrelated to any of the central star properties (such as age, spectral type
and activity).Comment: 15 pages, accepted by A&
The Massive Star-forming Regions Omnibus X-ray Catalog
We present the Massive Star-forming Regions (MSFRs) Omnibus X-ray Catalog
(MOXC), a compendium of X-ray point sources from {\em Chandra}/ACIS
observations of a selection of MSFRs across the Galaxy, plus 30 Doradus in the
Large Magellanic Cloud. MOXC consists of 20,623 X-ray point sources from 12
MSFRs with distances ranging from 1.7 kpc to 50 kpc. Additionally, we show the
morphology of the unresolved X-ray emission that remains after the catalogued
X-ray point sources are excised from the ACIS data, in the context of \Spitzer\
and {\em WISE} observations that trace the bubbles, ionization fronts, and
photon-dominated regions that characterize MSFRs. In previous work, we have
found that this unresolved X-ray emission is dominated by hot plasma from
massive star wind shocks. This diffuse X-ray emission is found in every MOXC
MSFR, clearly demonstrating that massive star feedback (and the
several-million-degree plasmas that it generates) is an integral component of
MSFR physics.Comment: Accepted to ApJS, March 3, 2014. 51 pages, 25 figure
Global Opportunities to Increase Agricultural Independence Through Phosphorus Recycling
Food production hinges largely upon access to phosphorus (P) fertilizer. Most fertilizer P used in the global agricultural system comes from mining of nonrenewable phosphate rock deposits located within few countries. However, P contained in livestock manure or urban wastes represents a recyclable source of P. To inform development of P recycling technologies and policies, we examined subnational, national, and global spatial patterns for two intersections of land use affording high P recycling potential: (a) manureârich cultivated areas and (b) populous cultivated areas. In turn, we examined overlap between P recycling potential and nationâlevel P fertilizer import dependency. Populous cultivated areas were less abundant globally than manureârich cultivated areas, reflecting greater segregation between crops and people compared to crops and livestock, especially in the Americas. Based on a global hexagonal grid (290âkm2 grid cell area), disproportionately large shares of subnational âhot spotsâ for P recycling potential occurred in India, China, Southeast Asia, Europe, and parts of Africa. Outside of China, most of the remaining manureârich or populous cultivated areas occurred within nations that had relatively high imports of P fertilizer (net P import:consumption ratios â„0.4) or substantial increases in fertilizer demand between the 2000s (2002â2006) and 2010s (2010â2014). Manureârich cultivated grid cells (those above the 75th percentiles for both manure and cropland extent) represented 12% of the global grid after excluding cropless cells. Annually, the global sum of animal manure P was at least 5 times that contained in human excreta, and among cultivated cells the ratio was frequently higher (median = 8.9). The abundance of potential P recycling hot spots within nations that have depended on fertilizer imports or experienced rising fertilizer demand could prove useful for developing local P sources and maintaining agricultural independence
Tracing the development of dust around evolved stars: The case of 47 Tuc
We observed mid-infrared (7.5-22 mum) spectra of AGB stars in the globular
cluster 47 Tuc with the Spitzer telescope and find significant dust features of
various types. Comparison of the characteristics of the dust spectra with the
location of the stars in a logP-K-diagram shows that dust mineralogy and
position on the AGB are related. A 13 mum feature is seen in spectra of low
luminosity AGB stars. More luminous AGB stars show a broad feature at 11.5 mum.
The spectra of the most luminous stars are dominated by the amorphous silicate
bending vibration centered at 9.7 mum. For 47 Tuc AGB stars, we conclude that
early on the AGB dust consisting primarily of Mg-, Al- and Fe oxides is formed.
With further AGB evolution amorphous silicates become the dominant species.Comment: 2 figures, accepted for publication in ApJ Letter
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