2,943 research outputs found
The Probability of Relatively Prime Polynomials
No abstract provided in this article
A deterministic cavity-QED source of polarization entangled photon pairs
We present two cavity quantum electrodynamics proposals that, sharing the
same basic elements, allow for the deterministic generation of entangled
photons pairs by means of a three-level atom successively coupled to two single
longitudinal mode high-Q optical resonators presenting polarization degeneracy.
In the faster proposal, the three-level atom yields a polarization entangled
photon pair via two truncated Rabi oscillations, whereas in the adiabatic
proposal a counterintuitive Stimulated Raman Adiabatic Passage process is
considered. Although slower than the former process, this second method is very
efficient and robust under fluctuations of the experimental parameters and,
particularly interesting, almost completely insensitive to atomic decay.Comment: 5 pages, 5 figure
Recounting the Odds of an Even Derangement
No abstract provided in this article
Tagged tiger shark (Galeocerda cuvieri) landed atTuticorin
The shark was caught by a mechanised Tuticorin type boat using hooks and line . The fish was caught at a distance of 40 km from shore southeast of Tuticorin in the 26 fathom depth area The fish weighed 130 kg and was sold by auction for Rupees 916. Morphometric measurements (in mm) of tagged tiger shark Galeocerda cuvieri caught off Tuticorin are Total length 2,050, Fork length 1,680, and detailed morphometry were recorded
Extraordinary transition in the two-dimensional O(n) model
The extraordinary transition which occurs in the two-dimensional O(n) model
for at sufficiently enhanced surface couplings is studied by conformal
perturbation theory about infinite coupling and by finite-size scaling of the
spectrum of the transfer matrix of a simple lattice model. Unlike the case of
in higher dimensions, the surface critical behaviour differs from that
occurring when fixed boundary conditions are imposed. In fact, all the surface
scaling dimensions are equal to those already found for the ordinary
transition, with, however, an interesting reshuffling of the corresponding
eigenvalues between different sectors of the transfer matrix.Comment: 18 pages, Latex, 12 eps figures; submitted to Nucl. Phys.
Quasiparticle Resonances in the BCS Approach
We present a simple method for calculating the energies and the widths of
quasiparticle resonant states. The method is based on BCS equations solved in
the Berggren representation. In this representation the quasiparticle
resonances are associated to the Gamow states of the mean field. The method is
illustrated for the case of neutron-rich nuclei O and Ni. It
is shown that the contribution of the continuum coupling to the pairing
correlations is small and largely dominated by a few resonant states close to
the continuum threshold.Comment: 14 pages, 2 figure
Evolving rules for document classification
We describe a novel method for using Genetic Programming to create compact classification rules based on combinations of N-Grams (character strings). Genetic programs acquire fitness by producing rules that are effective classifiers in terms of precision and recall when evaluated against a set of training documents. We describe a set of functions and terminals and provide results from a classification task using the Reuters 21578 dataset. We also suggest that because the induced rules are meaningful to a human analyst they may have a number of other uses beyond classification and provide a basis for text mining applications
Endo- and epiphytic fungal communities of olive twigs is influenced by cultivar and olive knot infection
Olive tree phyllosphere is colonized by a diverse microbial assemblage that may interact with pathogenic fungi, making them potential candidates for disease supression. Olive knot (OK) is a disease caused by the bacterium Pseudomonas savastanoi pv. savastanoi (Psv.) with significant economic losses in olive tree (Olea europaea L.). With this work we want to evaluate the effect of cultivar and OK infection on both endo- and epiphytic fungal community inhabiting olive twig tissues. For this, fungal composition and diversity was assessed in both asymptomatic and OK-symptomatic twigs of tree co-occurring olive cultivars with different susceptibilities to OK disease. The identification of isolated species was performed by ITS rDNA sequencing.
The cultivar and OK infection were important in shaping both endophytic and epiphytic fungal communities. Fungal community composition was found to differ significantly (p=0.005) between olive tree cultivars, being Nectriaceae the dominant family in cvs. Cobrançosa and Verdeal Transmontana, whereas Pleosporaceae was dominant in the cv. Madural. Epiphytic and endophytic fungal communities also differed in size and in composition in asymptomatic and OK-symptomatic twigs, for the three cultivars. In general, asymptomatic twigs were more diverse and rich (up to 1.4-fold) when compared to OK-symptomatic twigs. Among the species identified in the asymptomatic tissues, Cladosporium cladosporioides and Chromelosporium carneum were the most frequently isolated within epiphytic and endophytic community, respectively; whereas in the OK-symptomatic tissues Cladosporium sp. and Fusarium lateritium were the most frequently isolated within epiphytic and endophytic community, respectively. According to indicator species analysis C. carneum, Pyronema dosmesticum and Phoma aloes (IndVal up to 0.56) may be promising species in the OK suppression. Better acknowledgement should be developed in order to uncover their role on plant health.FEDER funds through COMPETE (Programa Operacional Factores de Competitividade}
and by national funds by FCT [Fundação para a Ciência e a Tecnologia) in the framework
of the project EXCL/AGR-PRO/0591/2012. T. Gomes thanks FCT, POPH-QREN and FSE
for PhD SFRH/BD/98127/2013 Grantinfo:eu-repo/semantics/publishedVersio
Observation of nonlinear self-trapping of broad beams in defocusing waveguide arrays
We demonstrate experimentally the localization of broad optical beams in periodic arrays of optical waveguides with defocusing nonlinearity. This observation in optics is linked to nonlinear self-trapping of Bose-Einstein-condensed atoms in stationary periodic potentials being associated with the generation of truncated nonlinear Bloch states, existing in the gaps of the linear transmission spectrum. We reveal that unlike gap solitons, these novel localized states can have an arbitrary width defined solely by the size of the input beam while independent of nonlinearity
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