4,435 research outputs found
Interacting epidemics and coinfection on contact networks
The spread of certain diseases can be promoted, in some cases substantially,
by prior infection with another disease. One example is that of HIV, whose
immunosuppressant effects significantly increase the chances of infection with
other pathogens. Such coinfection processes, when combined with nontrivial
structure in the contact networks over which diseases spread, can lead to
complex patterns of epidemiological behavior. Here we consider a mathematical
model of two diseases spreading through a single population, where infection
with one disease is dependent on prior infection with the other. We solve
exactly for the sizes of the outbreaks of both diseases in the limit of large
population size, along with the complete phase diagram of the system. Among
other things, we use our model to demonstrate how diseases can be controlled
not only by reducing the rate of their spread, but also by reducing the spread
of other infections upon which they depend.Comment: 9 pages, 3 figure
Beam loading compensation schemes for the muon recirculating Linacs of the CERN neutrino factory
Polars Changing State: Multiwavelength Long Term Photometry and Spectroscopy of QS Tel, V834 Cen, and BL Hyi
Long term optical and near-infrared photometric and blue spectroscopic
observations were obtained for QS Tel, V834 Cen, and BL Hyi. The optical light
curves of all three polars displayed large magnitude changes during our
observations. These same high/low state transitions were also apparent in
near-infrared JHK photometry, though with decreased amplitude. The color of the
polar with respect to its state was examined and found not to be a good
indicator of the instantaneous state. During low to high state transitions, a
nearly constant magnitude difference was observed in all three polars. This
m value was found to be consistent with the level expected to occur if
accretion onto the white dwarf reached the Eddington luminosity during the high
state. The high state Balmer decrement was measured for each star and used to
estimate that the temperature of the emission line forming region was ~12,000K
with N near 12.8 dex. No relationship between the Balmer emission line
strength and the white dwarf magnetic field strength was seen, in contrast to a
good correlation between these two parameters observed for UV emission lines.Comment: 9 figures, 4 tables; accepted for publication in PAS
Superconducting Superstructure for the TESLA Collider
We discuss the new layout of a cavity chain (superstructure) allowing, we
hope, significant cost reduction of the RF system of both linacs of the TESLA
linear collider. The proposed scheme increases the fill factor and thus makes
an effective gradient of an accelerator higher. We present mainly computations
we have performed up to now and which encouraged us to order the copper model
of the scheme, still keeping in mind that experiments with a beam will be
necessary to prove if the proposed solution can be used for the acceleration.Comment: 11 page
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