14,649 research outputs found
Fundraising and vote distribution: a non-equilibrium statistical approach
The number of votes correlates strongly with the money spent in a campaign,
but the relation between the two is not straightforward. Among other factors,
the output of a ballot depends on the number of candidates, voters, and
available resources. Here, we develop a conceptual framework based on Shannon
entropy maximization and Superstatistics to establish a relation between the
distributions of money spent by candidates and their votes. By establishing
such a relation, we provide a tool to predict the outcome of a ballot and to
alert for possible misconduct either in the report of fundraising and spending
of campaigns or on vote counting. As an example, we consider real data from a
proportional election with candidates, where a detailed data
verification is virtually impossible, and show that the number of potential
misconducting candidates to audit can be reduced to only nine
Micropropagação de alpínia [Alpinia purpurata (Vieill.) Schum] e sorvete (Zingiber spectabile Griff.) - Zingiberaceae: duas espécies ornamentais tropicais.
On Dirac-like Monopoles in a Lorentz- and CPT-violating Electrodynamics
We study magnetic monopoles in a Lorentz- and CPT-odd electrodynamical
framework in (3+1) dimensions. This is the standard Maxwell model extended by
means of a Chern-Simons-like term, (
constant), which respects gauge invariance but violates both Lorentz and CPT
symmetries (as a consequence, duality is also lost). Our main interest concerns
the analysis of the model in the presence of Dirac monopoles, so that the
Bianchi identity no longer holds, which naively yields the non-conservation of
electric charge. Since gauge symmetry is respected, the issue of charge
conservation is more involved. Actually, the inconsistency may be circumvented,
if we assume that the appearance of a monopole induces an extra electric
current. The reduction of the model to (2+1) dimensions in the presence of both
the magnetic sources and Lorentz-violating terms is presented. There, a
quantization condition involving the scalar remnant of , say, the mass
parameter, is obtained. We also point out that the breaking of duality may be
associated with an asymmetry between electric and magnetic sources in this
background, so that the electromagnetic force experienced by a magnetic pole is
supplemented by an extra term proportional to , whenever compared to the
one acting on an electric charge.Comment: 10 pages, no figures, typed in te
Two-species fermion mixtures with population imbalance
We analyze the phase diagram of uniform superfluidity for two-species fermion
mixtures from the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensation
(BEC) limit as a function of the scattering parameter and population imbalance.
We find at zero temperature that the phase diagram of population imbalance
versus scattering parameter is asymmetric for unequal masses, having a larger
stability region for uniform superfluidity when the lighter fermions are in
excess. In addition, we find topological quantum phase transitions associated
with the disappearance or appearance of momentum space regions of zero
quasiparticle energies. Lastly, near the critical temperature, we derive the
Ginzburg-Landau equation, and show that it describes a dilute mixture of
composite bosons and unpaired fermions in the BEC limit.Comment: 4 pages with 3 figures, accepted version to PR
Aspectos da associação micorrízica em plantas forrageiras (Bauhinia cheilanta e Dolichos lablab - Fabacea): simbiose e eficiência no crescimento vegetal sob condições semi-áridas.
Os objetivos desse trabalho foram avaliar a condição micorrízica e identificar espécies de FMA presentes nas rizosfera das plantas forrageiras: mororó (Bauhinia cheilanta) e lablab (Dolichos lablab), em condições semi-áridas, e selecionar espécies de FMA eficientes em promover a sobrevivência, o crescimento e o teor nutricional de plantas forrageiras em dois tipos de solo representativos da região do vale do submédio São Francisco
Karyotypic stability in asparagus (Asparagus officinalis L.) cultivars revealed by rDNA in situ Hybridization.
Four asparagus cultivars were cytologically studied by conventional staining and in situ hybridization, in order to evaluate both the variability among cultivars and the distribution pattern of 18S-25S rRNA genes. lhe mitotic and meiotic analysis with conventional chromosome staining did not show heteromorphisms or differences between cultivars. In situ hybridization with 18S and 25S rONA probes showed 6 chromosomes with 18S-25S rONA sites in the 4 studied genotypes. lhe New Jersey, Waltam Washington and G4X 14 cultivars presented 4 chromosomes with larger subterminal sites and 2 with interstitial sites of smaller size. In the Oeco cultivar, heteromorphism was verified in the size of the rONA sites, which were larger and subterminal in 3 chromosomes, and small and interstitial in 3 other chromosomes. lhe results suggest that asparagus cultivars may present only small differences in the number and distribution of rONA loci
Fungos micorrízicos arbusculares na rizosfera de plantas de mata ciliar do rio São Francisco, na região do vale do São Francisco.
How hole defects modify vortex dynamics in ferromagnetic nanodisks
Defects introduced in ferromagnetic nanodisks may deeply affect the structure
and dynamics of stable vortex-like magnetization. Here, analytical techniques
are used for studying, among other dynamical aspects, how a small cylindrical
cavity modify the oscillatory modes of the vortex. For instance, we have
realized that if the vortex is nucleated out from the hole its gyrotropic
frequencies are shifted below. Modifications become even more pronounced when
the vortex core is partially or completely captured by the hole. In these
cases, the gyrovector can be partially or completely suppressed, so that the
associated frequencies increase considerably, say, from some times to several
powers. Possible relevance of our results for understanding other aspects of
vortex dynamics in the presence of cavities and/or structural defects are also
discussed.Comment: 9 pages, 4 page
Exactly Solvable Models of Interacting Spin-s Particles in one-dimension
We consider the exact solution of a many-body problem of spin- particles
interacting through an arbitrary U(1) invariant factorizable -matrix. The
solution is based on a unified formulation of the quantum inverse scattering
method for an arbitrary -dimensional monodromy matrix. The respective
eigenstates are shown to be given in terms of creation fields by a general
new recurrence relation. This allows us to derive the spectrum and the
respective Bethe ansatz equations.Comment: 10 pages, plain late
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