43,671 research outputs found

    The broad-band X-ray spectrum of a QSO sample

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    A sample of 25 QSOs was used to investigate the average spectrum between the soft X-ray energy band of the Einstein Observatory image proportional counter, and the higher energy band of the HEAO 1 A2 experiment. The spectrum is similar to thoe exhibited by Seyfert galaxies and narrow emission line galaxies above 2 keV. The spectrum is soft enough that if these objects are typical of the higher redshift, more radio-quiet QSOs, then it is possible to exclude QSOs as being the dominant origin of the diffuse X-ray background

    Can an ethical revival of prudence within prudential regulation tackle corporate psychopathy?

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    The view that corporate psychopathy played a significant role in causing the global financial crisis, although insightful, paints a reductionist picture of what we present as the broader issue. Our broader issue is the tendency for psychopathy, narcissism and Machiavellianism to cluster psychologically and culturally as ‘dark leadership’ within global financial institutions. Strong evidence for their co-intensification across society and in corporations ought to alarm financial regulators. We argue that an ‘ethical revival’ of prudence within prudential regulation ought to be included in any package of solutions. Referencing research on moral muteness and the role of language in framing thoughts and behaviours, we recommend that regulators define prudence in an explicitly normative sense, an approach that may be further strengthened by drawing upon a widely appealing ethic of intergenerational care. An ethical revival of prudence, we argue, would allow the core problems of greed and myopia highlighted by corporate psychopathy theory to be addressed in a politically sensitive manner which recognises the pitfalls of regulating directly against corporate psychopathy. Furthermore, it would provide a viable conceptual framework to guide regulators along the treacherous path to more intrusive cultural regulation

    Autonomous spacecraft maintenance study group

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    A plan to incorporate autonomous spacecraft maintenance (ASM) capabilities into Air Force spacecraft by 1989 is outlined. It includes the successful operation of the spacecraft without ground operator intervention for extended periods of time. Mechanisms, along with a fault tolerant data processing system (including a nonvolatile backup memory) and an autonomous navigation capability, are needed to replace the routine servicing that is presently performed by the ground system. The state of the art fault handling capabilities of various spacecraft and computers are described, and a set conceptual design requirements needed to achieve ASM is established. Implementations for near term technology development needed for an ASM proof of concept demonstration by 1985, and a research agenda addressing long range academic research for an advanced ASM system for 1990s are established

    Polarization switching and induced birefringence in InGaAsP multiple quantum wells at 1.5 mu m

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    We analyze the 1.5mum wavelength operation of a room temperature polarization switch based on electron spin dynamics in InGaAsP multiple quantum wells. An unexpected difference in response for left and right circularly polarized pump light in pump-probe measurements was discovered and determined to be caused by an excess carrier induced birefringence. Transient polarization rotation and ellipticity were measured as a function of time delay. (C) 2002 American Institute of Physics.</p

    A limit to the X-ray luminosity of nearby normal galaxies

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    Emission is studied at luminosities lower than those for which individual discrete sources can be studied. It is shown that normal galaxies do not appear to provide the numerous low luminosity X-ray sources which could make up the 2-60 keV diffuse background. Indeed, upper limits suggest luminosities comparable with, or a little less than, that of the galaxy. This is consistent with the fact that the average optical luminosity of the sample galaxies within approximately 20 Mpc is slightly lower than that of the galaxy. An upper limit of approximately 1% of the diffuse background from such sources is derived

    The Galactic bulge as seen in optical surveys

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    The bulge is a region of the Galaxy of tremendous interest for understanding galaxy formation. However measuring photometry and kinematics in it raises several inherent issues, such as severe crowding and high extinction in the visible. Using the Besancon Galaxy model and a 3D extinction map, we estimate the stellar density as a function of longitude, latitude and apparent magnitude and we deduce the possibility of reaching and measuring bulge stars with Gaia. We also present an ongoing analysis of the bulge using the Canada-France-Hawaii Telescope.Comment: In SF2A-2008: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysic

    Breeding System Effects on Production Efficiency Through Weaning-Preliminary Results

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    Preliminary results are presented on production efficiency for a comparison of two-breed rotational crossbreeding to the terminal phase of a rotational-terminal combination system with Charolais as the terminal sire breed. The breeding system comparisons were made within each of three types of dam: Simmental x Hereford, Angus x Hereford, and Tarentaise x Hereford. The two breeding systems had similar average values for dam size, condition score, and feed ME through weaning. Results indicate an increase for terminal matings compared to rotational matings in terms of weaning weight and efficiency ratio (calf weaning weight/dam and calf feed ME) within the Angus x Hereford group, while the effect of breeding system was nonsignificant within the other two dam types
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