5,598 research outputs found
Introduced Purple Loosestrife as Host of Native Saturniidae (Lepidoptera)
Purple loosestrife (Lythrum salicaria,Lythraceae) arrived in North America nearly 200 years ago. In 1969 we first found larvae of the native Cecropia (Hyalophora cecropia) and Polyphemus (Antheraea polyphemus) moths (Lepidoptera: Saturniidae) on loosestrife in the Hudson River Valley, New York, and we have since found Io (Automeris io) on this plant. A census of 4th and 5th instar saturniids in four 0.25 ha plots in purple loosestrife-gray dogwood (Cornus racemosa) wet meadows near Saugerties in 1984 indicated that Polyphemus and Cecropia larvae occurred much more frequently on loosestrife than on dogwood, a native host. The switch from native woody hosts to an introduced herb may have been facilitated by the dense shrub- like habit, high productivity, and high tannin content of loosestrife
Asymptotic behaviour of gossip processes and small world networks
Both small world models of random networks with occasional long range
connections and gossip processes with occasional long range transmission of
information have similar characteristic behaviour. The long range elements
appreciably reduce the effective distances, measured in space or in time,
between pairs of typical points. In this paper, we show that their common
behaviour can be interpreted as a product of the locally branching nature of
the models. In particular, it is shown that both typical distances between
points and the proportion of space that can be reached within a given distance
or time can be approximated by formulae involving the limit random variable of
the branching process.Comment: 30 page
The shortest distance in random multi-type intersection graphs
Using an associated branching process as the basis of our approximation, we
show that typical inter-point distances in a multitype random intersection
graph have a defective distribution, which is well described by a mixture of
translated and scaled Gumbel distributions, the missing mass corresponding to
the event that the vertices are not in the same component of the graph.Comment: 32 page
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Genome Sequences of Three Lactobacillus Species Strains of the Stomach of the White-Footed Deermouse (Peromyscus leucopus).
Three colony types of Lactobacillus were isolated from the stomach of LL colony stock Peromyscus leucopus deermice, a reservoir for several human zoonoses. Genome sequences revealed two isolates to be new strains of Lactobacillus animalis and Lactobacillus reuteri The third was distinct from known species and was provisionally designated Lactobacillus sp. strain LL6
Finite density QCD with heavy quarks
In the large fermion mass limit of QCD at finite density the structure of the
partition function greatly simplifies and can be studied analytically. We show
that, contrary to general wisdom, the phase of the Dirac determinant is
relevant only at finite temperature and can be neglected for zero temperature
fields.Comment: LATTICE98(hightemp), 3 pages, 3 figure
Frustration in Finite Density QCD
We present a detailed analysis of the QCD partition function in the Grand
Canonical formalism. Using the fugacity expansion we find evidence for
numerical instabilities in the standard evaluation of its coefficients. We
discuss the origin of this problem and propose an issue to it. The correct
analysis shows no evidence for a discontinuity in the baryonic density in the
strong coupling limit. The moderate optimism that was inspired by the Grand
Canonical Partition Function calculations in the last years has to be
considered ill-founded.Comment: 9 pages, 6 Postscript figures; some comments adde
Phase transition(s) in finite density QCD
The Grand Canonical formalism is generally used in numerical simulations of
finite density QCD since it allows free mobility in the chemical potential
. We show that special care has to be used in extracting numerical results
to avoid dramatic rounding effects and spurious transition signals. If we
analyze data correctly, with reasonable statistics, no signal of first order
phase transition is present and results using the Glasgow prescription are
practically coincident with the ones obtained using the modulus of the
fermionic determinant.Comment: 6 pages, 5 ps figs. To appear in Proceedings of "QCD at Finite Baryon
Density" workshop, Bielefeld, 27-30 April 199
Isolation and cultivation of Lyme disease spirochetes.
The successful isolation and cultivation of Lyme disease spirochetes traces its lineage to early attempts at cultivating relapsing fever borreliae. Observations on the growth of Lyme disease spirochetes under different in vitro conditions may yield important clues to both the metabolic characteristics of these newly discovered organisms and the pathogenesis of Lyme disease
Three and Two Colours Finite Density QCD at Strong Coupling: A New Look
Simulations in finite density, beta=0 lattice QCD by means of the
Monomer-Dimer-Polymer algorithm show a signal of first order transition at
finite temporal size. This behaviour agrees with predictions of the mean field
approximation, but is difficult to reconcile with infinite mass analytical
solution. The MDP simulations are considered in detail and severe convergence
problems are found for the SU(3) gauge group, in a wide region of chemical
potential. Simulations of SU(2) model show discrepancies with MDP results as
well.Comment: 18 pages, 9 figures, to appear in Nucl. Phys.
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