1,625 research outputs found
Antimicrobial susceptibility assessment of Campylobacter on outdoor iberian pig sows
Both Campylobacter and Salmonella are considered the most frequent bacterial causes of human enteritis in
industrialized countries. The consumption of raw or undercooked poultry and pork contaminated meat products
are the main sources of human infection. The prevalence of Campylobacter and Salmonella was determined in
the present work for extensive production Iberian pig sows, Sus mediterraneus. Samples were collected at the
maternity area of a creator from, water drinkers, feed and feed containers as well as from sows faecal matter. Of
42 samples, 31 and 23 carried Campylobacter spp. and Salmonella spp. respectively. Only Salmonella spp. was
found in all 3 tested water and feed containers. Of the 58 isolated Campylobacter strains only one was identified,
by multiplex-PCR, as Campylobacter jejuni, all other were C. coli. Antibiotic susceptibility was performed by
disc diffusion method with Nalidixic acid, Ciprofloxacin, Erythromycin, Tetracycline, Chloramphenicol and
Ampicilin. While 95% of the tested strains were susceptible to chloramphenicol, 66% and 53% were resistant to
the tested fluoroquinolones, Ciprofloxacin and Nalidixic acid respectively. Erythromycin resistance was fairly
low in comparison to previous publications with 14% of resistant strains. 38% were resistant to Tetracycline and
57% to Ampicilin. Seven of the 58 Campylobacter strains were entirely susceptible and none were resistant to all
the antimicrobials tested. Multiple drug resistance was found in 88% of strains. Cross contamination may occur
between sows inside maternity facilities and piglets may become infected in an early age by their mothers. New
and better control measures are therefore necessary to minimize transmission between animals reducing the
number of contaminated individuals and the potential transmission to human handlers and consumers
On the integrability of the SU(N) Hubbard model
We exhibit explicitly the intertwiner operator for the monodromy matrices of
the recent proposed SU(N) Hubbard model [5]. This produces a new family of
non-additive R-matrices and generalizes an earlier result by Shastry [2].Comment: 4 page
Bethe ansatz solution of the invariant spin chain
We have applied the analytical Bethe ansatz approach in order to solve the
invariant magnet. By using the Bethe ansatz equations we have
calculated the ground state energy and the low-lying dispersion relation. The
finite size properties indicate that the model has a central charge .Comment: 9 page
The algebraic Bethe ansatz for rational braid-monoid lattice models
In this paper we study isotropic integrable systems based on the braid-monoid
algebra. These systems constitute a large family of rational multistate vertex
models and are realized in terms of the B_n, C_n and D_n Lie algebra and by the
superalgebra Osp(n|2m). We present a unified formulation of the quantum inverse
scattering method for many of these lattice models. The appropriate fundamental
commutation rules are found, allowing us to construct the eigenvectors and the
eigenvalues of the transfer matrix associated to the B_n, C_n, D_n,
Osp(2n-1|2), Osp(2|2n-2), Osp(2n-2|2) and Osp(1|2n) models. The corresponding
Bethe Ansatz equations can be formulated in terms of the root structure of the
underlying algebra.Comment: plain latex, 48 pages, 1 figure (under request
Feeding behaviour of Barbus Bocagei assessed under a spatio-temporal approach
The feeding behaviour of Barbus bocagei was assessed in a lowland system by a two years survey
Of two contrasting sites also talking into account, for the first time diurnal changes of fish diet and benthos availability
Cosmic Numbers: A Physical Classification for Cosmological Models
We introduce the notion of the cosmic numbers of a cosmological model, and
discuss how they can be used to naturally classify models according to their
ability to solve some of the problems of the standard cosmological model.Comment: 3 pages, no figures. v2: Two references added, cosmetic changes.
Version to appear in Phys. Rev. D (Brief reports
Biogas production by anaerobic codigestion using kiwi waste and wine sludge
Considering a large generation of wastes, the anaerobic codigestion (AcoD) is an alternative to transform two or more types of organic waste in energy and biofertilizer. To test the biogas production potential using kiwi waste and wine sludge, two AD assays with each substrate isolated and AcoD with four different substrate proportion was realized, using as inoculum sludge from a septic tank. The experimental was realized during 19 days in batch reactor (250 mL). Among digestion results, kiwi waste had de best result, being 27.0 mLN gVS-1 of biogas. The most satisfactory value in AcoD was 40.5 mLN g VS-1 of biogas, from treatment with 0.5 g kiwi and 3.3 g wine sludge. The AcoD test produced 16 mLN gVS-1 of biogas more than ADinfo:eu-repo/semantics/publishedVersio
Genetic and virulence characterization of Toxoplasma gondii strains isolated from pigeons in Lisbon region
habitat with cats and humans, bands are observed in recreational areas such as urban parks, playgrounds and parks. The interaction between cats, birds and human population is quite evident favoring the fecal-oral transmission of T. gondii between the definitive host and intermediate hosts, in the urban cycle of the parasite. The results of the inoculation in vivo of the brain homogenates showed pigeon isolation rates (58.5%) significantly higher when compared with previous studies, including the preliminary study in 2006 that the isolation rate in mice was 39,1% (9/23) (Waap 2008) and another that was not achieved any isolation in mouse (Godoi 2010). The genotypic analysis revealed a majority of strains of type II, which is consistent with what has been described in Portugal, the rest of Europe and the USA (Ajzenberg 2005, Fazaeli 2000, Honoré 2000, Howe 1997, Waap 2008) . We also isolated strains of type III and type I. The identification of type III strains in animals have been reported by other authors, but the type I have been rarely found in animals has not been previously described in Portugal except in a preliminary study of our team at the 2008 (Waap 2008). The type I strains are usually associated with high virulence in laboratory mice, leading to death within days. This strain was identified by molecular biology and has not been isolated in vivo. The difficulty in isolation of strain may be related to the small number of cysts of the type I strains can develop, these type strains are considered low cystogenic. Genetic characterization of strains of T. gondii is far from its terminus, more sequences of different genes should be studied to help the understanding of the molecular epidemiology and genetic characterization of T. gondii, a relevant parasite for which these data are lacking. The combination of data from humans and animals, through the use of high resolution genetic characterization should improve our perceptive of T. gondii, which will be ultimately beneficial for the control of T. gondii transmission
Exact solution and finite size properties of the vertex model
We have diagonalized the transfer matrix of the vertex
model by means of the algebraic Bethe ansatz method for a variety of grading
possibilities. This allowed us to investigate the thermodynamic limit as well
as the finite size properties of the corresponding spin chain in the massless
regime. The leading behaviour of the finite size corrections to the spectrum is
conjectured for arbitrary . For we find a critical line with central
charge whose exponents vary continuously with the -deformation
parameter. For the finite size term related to the conformal anomaly
depends on the anisotropy which indicates a multicritical behaviour typical of
loop models.Comment: 40 pages, 8 figures, late
New R-matrices from Representations of Braid-Monoid Algebras based on Superalgebras
In this paper we discuss representations of the Birman-Wenzl-Murakami algebra
as well as of its dilute extension containing several free parameters. These
representations are based on superalgebras and their baxterizations permit us
to derive novel trigonometric solutions of the graded Yang-Baxter equation. In
this way we obtain the multiparametric -matrices associated to the
, and
quantum symmetries. Two other families of multiparametric -matrices not
predicted before within the context of quantum superalgebras are also
presented. The latter systems are indeed non-trivial generalizations of the
vertex model when both distinct edge variables statistics
and extra free-parameters are admissible.Comment: 26 page
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