9,933 research outputs found
Are there socioeconomic gradients in stage and grade of breast cancer at diagnosis? Cross sectional analysis of UK cancer registry data
Socioeconomic gradients in uptake of breast cancer screening in the United Kingdom should, intuitively, lead to socioeconomic gradients in disease progression at diagnosis. However, studies have found little evidence of such an effect. Although this could be interpreted as evidence that socioeconomic gradients in uptake of screening do not have clinically important consequences, all of the published studies have used data from before (pre-1988) or during the early stages (1988-95) of implementation of the national breast cancer screening programme. We investigated the relation between socioeconomic position and progression of breast cancer at diagnosis by using recent data from the Northern and Yorkshire Cancer Registry and Information Service (NYCRIS), which is estimated to achieve around 93% ascertainment
Survivor Funds
This Article explains how to create “survivor funds”—short-term investment funds that would pay more to those investors who live until the end of the fund’s term than to those who die before then. For example, instead of just investing in a ten-year bond and dividing the proceeds among the investors at the end of the bond term, a survivor fund would invest in that ten-year bond but divide the proceeds only among those who survived the full ten years. These survivor funds would be attractive investments because the survivors would get a greater return on their investments, while the decedents, for obvious reasons, would not care. Survivor funds would work like short-term tontines.
Basically, a tontine is a financial product that combines features of an annuity and a lottery. In a simple tontine, a group of investors pools their money together to buy a portfolio of investments, and, as investors die, their shares are forfeited, often with the entire fund going to the last survivor. For example, imagine that ten 65-year-old men each contribute 10,000 and that the men agree that the last “survivor will get the diamond. Accordingly, after the ninth man dies, the tenth man gets the diamond, and he can keep it or sell it. Of course, the survivor principle—that the share of each, at death, is enjoyed by the survivors—can be used to design financial products that would benefit multiple survivors, not just the last survivor. For example, elsewhere, we showed how tontines could be used to create so-called “tontine annuities” and “tontine pensions” that would benefit lots of retirees. In this Article, we show how the survivor principle can be used to create survivor funds that would only make payments to those who survive for a specified number of years
Substructure: Clues to the Formation of Clusters of Galaxies
We have examined the spatial distribution of substructure in clusters of
galaxies using Einstein X-ray observations. Subclusters are found to have a
markedly anisotropic distribution that reflects the surrounding matter
distribution on supercluster scales. Our results suggest a picture in which
cluster formation proceeds by mergers of subclusters along large-scale
filaments. The implications of such an anisotropic formation process for the
shapes, orientations and kinematics of clusters are discussed briefly.Comment: 7 pages, uuencoded compressed postscript. To appear in ApJ Letters
(September 20, 1995 issue
Ion sputter textured graphite electrode plates
A specially textured surface of pyrolytic graphite exhibits extremely low yields of secondary electrons and reduced numbers of reflected primary electrons after impingement of high energy primary electrons. Electrode plates of this material are used in multistage depressed collectors. An ion flux having an energy between 500 iV and 1000 iV and a current density between 1.0 mA/sq cm and 6.0 mA/sq cm produces surface roughening or texturing which is in the form of needles or spires. Such textured surfaces are especially useful as anode collector plates in high tube devices
Ion sputter textured graphite
A specially textured surface of pyrolytic graphite exhibits extremely low yields of secondary electrons and reduced numbers of reflected primary electrons after impingement of high energy primary electrons. An ion flux having an energy between 500 eV and 1000 eV and a current density between 1.0 mA/sq cm and 6.0 mA/sq cm produces surface roughening or texturing which is in the form of needles or spines. Such textured surfaces are especially useful as anode collector plates in high efficiency electron tube devices
Propagation of the phase of solar modulation
The phase of the 11 year galactic cosmic ray variation, due to a varying rate of emission of long lived propagating regions of enhanced scattering, travels faster than the scattering regions themselves. The radial speed of the 11 year phase in the quasi-steady, force field approximation is exactly twice the speed of the individual, episodic decreases. A time dependent, numerical solution for 1 GeV protons at 1 and 30 Au gives a phase speed which is 1.85 times the propagation speed of the individual decreases
Intracluster Globular Clusters
Globular cluster populations of supergiant elliptical galaxies are known to
vary widely, from extremely populous systems like that of UGC 9799, the
centrally dominant galaxy in Abell 2052, to globular-cluster-poor galaxies such
as NGC 5629 in Abell 2666. Here we propose that these variations point strongly
to the existence of a population of globular clusters that are not bound to
individual galaxies, but rather move freely throughout the cores of clusters of
galaxies. Such intracluster globular clusters may have originated as tidally
stripped debris from galaxy interactions and mergers, or alternatively they may
have formed in situ in some scenarios of globular cluster formation.Comment: 9 pages, uuencoded compressed postscript. Accepted for publication in
the Astrophysical Journal Letter
The Disturbed 17 keV Cluster Associated with the Radio Galaxy 3C 438
We present results from a {\em Chandra} observation of the cluster gas
associated with the FR II radio galaxy 3C 438. This radio galaxy is embedded
within a massive cluster with gas temperature 17 keV and bolometric
luminosity of 6 ergs s. It is unclear if this high
temperature represents the gravitational mass of the cluster, or if this is an
already high ( 11 keV) temperature cluster that has been heated
transiently. We detect a surface brightness discontinuity in the gas that
extends 600 kpc through the cluster. The radio galaxy 3C 438 is too small
(110 kpc across) and too weak to have created this large disturbance in
the gas. The discontinuity must be the result of either an extremely powerful
nuclear outburst or the major merger of two massive clusters. If the observed
features are the result of a nuclear outburst, it must be from an earlier epoch
of unusually energetic nuclear activity. However, the energy required
( ergs) to move the gas on the observed spatial scales strongly
supports the merger hypothesis. In either scenario, this is one of the most
extreme events in the local Universe.Comment: 13 pages, 4 figures, 1 table - accepted for publication in the
Astrophysical Journal Letter
Flaw growth behavior in thick welded plates of 2219-T87 aluminum at room and cryogenic temperatures
Axial load fatigue and fracture tests were conducted on thick welded plates of 2219-T87 aluminum alloy to determine the tensile strength properties and the flaw growth behavior in electron beam, gas metal arc, and pulse current gas tungsten arc welds for plates 6.35 centimeters (2.5 in.) thick. The tests were conducted in room temperature air and in liquid nitrogen environments. Specimens were tested in both the as-welded and the aged after welding conditions. The experimental crack growth rate were correlated with theoretical crack growth rate predictions for semielliptical surface flaws
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