Some determinants of organizational success

Organizational efficiency and productivity determined by variables associated with economics, psychology, and sociolog

Rapid X-ray variability from the Seyfert 1 Galaxy NGC 4051

Strong variable X-ray emission from the nearby low luminosity Seyfert 1 galaxy NGC 4051 was discovered during observations with the imaging proportional counter of the Einstein Observatory. During one 2304 second observation, the X-ray flux more than doubled in an approximately linear fashion, and a 70% increase for 150 seconds was seen during another 968 second observation. Evidence is presented which demonstrates that the X-ray spectrum of NGC 4051 is unusually soft compared to Seyfert 1 galaxies or QSOs. The emission mechanism is probably not synchrotron or synchrotron self-Compton, but the emission can be plausibly explained by various black hole accretion models

Human Capital, Fertility, and Economic Growth

Our model of growth departs from both the Malthusian and neoclassical approaches by including investments in human capital. We assume, crucially, that rates of return on human capital investments rise, rather than, decline, as the stock of human capital increases, until the stock becomes large. This arises because the education sector uses human capital note intensively than either the capital producing sector of the goods producing sector. This produces multiple steady scares: an undeveloped steady stare with little human capital, low rates of return on human capital investments and high fertility, and a developed steady stats with higher rates of return a large, and, perhaps, growing stock of human capital and low fertility. Multiple steady states mean that history and luck are critical determinants of a country's growth experience.

The X-ray nebula of the filled center supernova remnant 3C58 and its interaction with the environment

An \xmm observation of the plerionic supernova remnant 3C58 has allowed us to study the X-ray nebula with unprecedented detail. A spatially resolved spectral analysis with a resolution of 8\arcsec has yielded a precise determination of the relation between the spectral index and the distance from the center. We do not see any evidence for bright thermal emission from the central core. In contrast with previous ASCA and {\em Einstein} results, we derive an upper limit to the black-body 0.5-10 keV luminosity and emitting area of $1.8\times 10^{32}$ \ergsec and $1.3\times 10^{10}$ cm$^2$, respectively, ruling out emission from the hot surface of the putative neutron star and also excluding the "outer-gap" model for hot polar caps. We have performed for the first time a spectral analysis of the outer regions of the X-ray nebula, where most of the emission is still non-thermal, but where the addition of a soft (kT=0.2-0.3 keV) optically thin plasma component is required to fit the spectrum at $E<1$ keV. This component provides 6% of the whole remnant observed flux in the 0.5-10.0 keV band. We show that a Sedov interpretation is incompatible with the SN1181-3C58 association, unless there is a strong deviation from electron-ion energy equipartition, and that an origin of this thermal emission in terms of the expansion of the nebula into the ejecta core nicely fits all the radio and X-ray observations.Comment: 10 pages, 7 figures, accepted for publication in A&

A technique for automatic real time scoring of several simultaneous sleep electroencephalograms

Automatic real-time scoring of simultaneous sleep electroencephalogram

Quantum Gravity Corrections for Schwarzschild Black Holes

We consider the Matrix theory proposal describing eleven-dimensional Schwarzschild black holes. We argue that the Newtonian potential between two black holes receives a genuine long range quantum gravity correction, which is finite and can be computed from the supergravity point of view. The result agrees with Matrix theory up to a numerical factor which we have not computed.Comment: 14 pages, Tex, no figure

The X-ray emitting galaxy Cen-A

OSO-8 X-ray observations of Cen-A in 1975 and 1976 are reported. The source spectrum is well fit in both years by a power law of number index 1.62 and absorption due to 1.3 x 10 to the 23rd power at/sq cm. The total flux varied by a factor 2 between 1975 and 1976. In 1976 there were approximately 40% flux variations on a time scale of days. The 6.4 keV Fe fluorescent line and the 7.1 keV absorption edge were measured implying Fe/H approximately equals .000016. Simultaneous radio measurements show variation in phase with X-ray variability. Models considering radio, milimeter, IR and X-ray data show that all the data can be accounted for by a model in which the X-rays are due to a synchrotron self-Compton source embedded in a cold H(2) cloud