Theoretical Sensitivity Analysis for Quantitative Operational Risk Management

We study the asymptotic behavior of the difference between the values at risk VaR(L) and VaR(L+S) for heavy tailed random variables L and S for application in sensitivity analysis of quantitative operational risk management within the framework of the advanced measurement approach of Basel II (and III). Here L describes the loss amount of the present risk profile and S describes the loss amount caused by an additional loss factor. We obtain different types of results according to the relative magnitudes of the thicknesses of the tails of L and S. In particular, if the tail of S is sufficiently thinner than the tail of L, then the difference between prior and posterior risk amounts VaR(L+S) - VaR(L) is asymptotically equivalent to the expectation (expected loss) of S.Comment: 21 pages, 1 figure, 4 tables, forthcoming in International Journal of Theoretical and Applied Finance (IJTAF

The effect of irradiation-induced disorder on the conductivity and critical temperature of the organic superconductor κ\kappa-(BEDT-TTF)2_2Cu(SCN)2_2

We have introduced defects into clean samples of the organic superconductor $\kappa$-(BEDT-TTF)$_2$Cu(SCN)$_2$ in order to determine their effect on the temperature dependence of the conductivity and the critical temperature $T_{\rm c}$. We find a violation of Matthiessen's rule that can be explained by a model of the conductivity involving a defect-assisted interlayer channel which acts in parallel with the band-like conductivity. We observe an unusual dependence of $T_{\rm c}$ on residual resistivity which is not consistent with the generalised Abrikosov-Gor'kov theory for an order parameter with a single component, providing an important constraint on models of the superconductivity in this material

Fall 1969

Massachusetts Lawn and Turf Grass CouncilBetter Turf Through Research and Education Artificial Turf Faces Credibility Gab by Dr. Gene C. Nutter (page 1) Nitrogen Facts and Fallacies by W.H. Garman (2) DDT Opponents by Charles Wurster, Jr. (10) DDT Defenders by Charles Wurster, Jr. (11) What Type 2,4-D to Use? by J.S. Coartney and A.H. Kates (21) Irrigation Circuit Break Pinpointed in One Hour (24

Stellar Dynamics and the implications on the merger evolution in NGC6240

We report near-infrared integral field spectroscopy of the luminous merging galaxy NGC 6240. Stellar velocities show that the two K-band peaks separated by 1.6arcsec are the central parts of inclined, rotating disk galaxies with equal mass bulges. The dynamical masses of the nuclei are much larger than the stellar mass derived from the K-band light, implying that the progenitor galaxies were galaxies with massive bulges. The K-band light is dominated by red supergiants formed in the two nuclei in starbursts, triggered ~2x10^7 years ago, possibly by the most recent perigalactic approach. Strong feedback effects of a superwind and supernovae are responsible for a short duration burst (~5x10^6 years) which is already decaying. The two galaxies form a prograde-retrograde rotating system and from the stellar velocity field it seems that one of the two interacting galaxies is subject to a prograde encounter. Between the stellar nuclei is a prominent peak of molecular gas (H_2, CO). The stellar velocity dispersion peaks there indicating that the gas has formed a local, self-gravitating concentration decoupled from the stellar gravitational potential. NGC 6240 has previously been reported to fit the paradigm of an elliptical galaxy formed through the merger of two galaxies. This was based on the near-infrared light distribution which follows a r^1/4-law. Our data cast strong doubt on this conclusion: the system is by far not relaxed, rotation plays an important role, as does self-gravitating gas, and the near-infrared light is dominated by young stars.Comment: 34 pages, 11 figures, using AASTEX 5.0rc3.1, paper submitted to the Astrophysical Journal, revised versio

Burnout in the ICU : potential consequences for staff and patient well-being

Peer reviewedAuthor versio

Discovery of a nuclear gas bar feeding the active nucleus in Circinus

We report the discovery of gas inflow motions towards the active nucleus of the Circinus galaxy caused by the non-axisymmetric potential of a nuclear gas bar. Evidence for dust associated with the bar comes from the HST/NICMOS H-K color map, whereas the streaming motions along the gas bar are seen in the velocity field of the H2 S(1)(1-0) emission line. The gas bar is about 100 pc long with a visual extinction in excess of 10 mag. Indication for the gaseous nature of this bar comes from the lack of a stellar counterpart even in the K band where the extinction is greatly reduced. We also use the NICMOS emission line images (Pa-alpha, [SiVI], and [FeII]) to study the innermost region of the ionization cones and the nuclear star forming activity. We discuss the possible relationship of these components with the gaseous bar.Comment: 14 pages, 7 figures (3 color plates), accepted for publication in Ap

NICMOS Imaging of Infrared-Luminous Galaxies

We present near-infrared images obtained with the HST NICMOS camera for a sample of 9 luminous (LIGs: L_IR (8-1000 microns) >~ 10^11 L_sun) and 15 ultra-luminous (ULIGS: L_IR >~ 10^12 L_sun) infrared galaxies. The sample includes representative systems classified as warm (f_25/f_60 > 0.2) and cold (f_25/f_60 <~ 0.2) based on the mid-infrared colors and systems with nuclear emission lines classified as HII (i.e. starburst), QSO, Seyfert and LINER. The morphologies of the sample galaxies are diverse and provide further support for the idea that they are created by the collision or interactions of spiral galaxies. Although no new nuclei are seen in the NICMOS images, the NICMOS images do reveal new spiral structures, bridges, and circumnuclear star clusters...Comment: LaTex, 27 pages with 14 gif and 4 jpg figures, AJ, in press, contour figures of the NICMOS images can be viewed at http://nedwww.ipac.caltech.edu/level5/Scoville/frames.htm

Extreme values and fat tails of multifractal fluctuations

In this paper we discuss the problem of the estimation of extreme event occurrence probability for data drawn from some multifractal process. We also study the heavy (power-law) tail behavior of probability density function associated with such data. We show that because of strong correlations, standard extreme value approach is not valid and classical tail exponent estimators should be interpreted cautiously. Extreme statistics associated with multifractal random processes turn out to be characterized by non self-averaging properties. Our considerations rely upon some analogy between random multiplicative cascades and the physics of disordered systems and also on recent mathematical results about the so-called multifractal formalism. Applied to financial time series, our findings allow us to propose an unified framemork that accounts for the observed multiscaling properties of return fluctuations, the volatility clustering phenomenon and the observed ``inverse cubic law'' of the return pdf tails