26,782 research outputs found
Hierarchic trees with branching number close to one: noiseless KPZ equation with additional linear term for imitation of 2-d and 3-d phase transitions.
An imitation of 2d field theory is formulated by means of a model on the
hierarhic tree (with branching number close to one) with the same potential and
the free correlators identical to 2d correlators ones.
Such a model carries on some features of the original model for certain scale
invariant theories. For the case of 2d conformal models it is possible to
derive exact results. The renormalization group equation for the free energy is
noiseless KPZ equation with additional linear term.Comment: latex, 5 page
Pathogenicity of the root-knot nematode Meloidogyne javanica on potato
Host–parasite relationships and pathogenicity of
Meloidogyne javanica
on potatoes (newly recorded from Malta) were
studied under glasshouse and natural conditions. Potato cvs Cara and Spunta showed a typical susceptible reaction to
M. javanica
under natural and artificial infections, respectively. In potato tubers,
M. javanica
induced feeding sites that
consisted of three to four hypertrophied giant cells per adult female. Infection of feeder roots by the nematode resulted
in mature large galls which usually contained at least one mature female and egg mass. In both tubers and roots, feeding
sites were characterized by giant cells containing granular cytoplasm and many hypertrophied nuclei. Cytoplasm in giant
cells was aggregated alongside the thickened cell walls. Stelar tissues within galls appeared disorganized. The relationship
between initial nematode population density (
P
) [0–64 eggs + second-stage juveniles (J2s) per cm
3
soil] and growth of
cv. Spunta potato seedlings was tested under glasshouse conditions. A Seinhorst model [
y = m
+ (1
−
m
)
z
(
P
−
T
)
] was fitted
to fresh shoot weight and shoot height data of nematode-inoculated and control plants. Tolerance limits (
T
) for fresh
shoot weight and shoot height of cv. Spunta plants infected with
M. javanica
were 0·50 and 0·64 eggs + J2s per cm
3
soil,
respectively. The
m
parameter in that model (i.e. the minimum possible
y
-values) for fresh shoot weight and shoot height
were 0·60 and 0·20, respectively, at
P
= 64 eggs + J2s per cm
3
soil. Root galling was proportional to the initial nematode
population density. Maximum nematode reproduction rate was 51·2 at a moderate initial population density (
P
= 4
eggs + J2s per cm
3
soil).peer-reviewe
El proceso de revisión del Concordato de 1953.
Material incluido en el volumen especial de la revista del Instituto Martín de Azpilcueta, Universidad de Navarra : Ius Canonicum (1999), en honor de Javier Hervada
Implications from GW170817 and I-Love-Q relations for relativistic hybrid stars
Gravitational wave observations of GW170817 placed bounds on the tidal
deformabilities of compact stars allowing one to probe equations of state for
matter at supranuclear densities. Here we design new parametrizations for
hybrid hadron-quark equations of state, that give rise to low-mass twin stars,
and test them against GW170817. We find that GW170817 is consistent with the
coalescence of a binary hybrid star--neutron star. We also test and find that
the I-Love-Q relations for hybrid stars in the third family agree with those
for purely hadronic and quark stars within for both slowly and
rapidly rotating configurations, implying that these relations can be used to
perform equation-of-state independent tests of general relativity and to break
degeneracies in gravitational waveforms for hybrid stars in the third family as
well.Comment: 8 pages, 4 figures, 2 tables; matches published version, updated fig.
Seedling Emergence from Seed Banks in Ludwigia hexapetala-Invaded Wetlands: Implications for Restoration
Soil seed banks play a critical role in the maintenance of wetland plant communities and contribute to revegetation following disturbances. Analysis of the seed bank can therefore inform restoration planning and management. Emergence from seed banks may vary in response to hydrologic conditions and sediment disturbances. To assess the community-level impact of exotic Ludwigia hexapetala on soil seed banks, we compared differences in species composition of standing vegetation among invaded and non-invaded wetlands and the degree of similarity between vegetation and soil seed banks in northern California. To determine potential seed bank recruitment of L. hexapetala and associated plant species, we conducted a seedling emergence assay in response to inundation regime (drawdown vs. flooded) and sediment depth (surface vs. buried). Plant species richness, evenness, and Shannon’s H’ diversity were substantially lower in standing vegetation at L. hexapetala invaded sites as compared to non-invaded sites. Over 12 months, 69 plant taxa germinated from the seed banks, including L. hexapetala and several other exotic taxa. Seedling density varied among sites, being the highest (10,500 seedlings m−2) in surface sediments from non-invaded sites subjected to drawdown treatments. These results signal the need for invasive plant management strategies to deplete undesirable seed banks for restoration success
Characterization and analysis of azimuthally sensitive correlations
A unified framework for describing the azimuthal dependence of two-particle
correlations in heavy-ion collisions is introduced, together with the methods
for measuring the corresponding observables. The generalization to azimuthal
correlations between more than two particles is presented.Comment: 7 pages; talk given at Hot Quarks 2004, Taos (NM), July 18-24,200
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