53,885 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
Axion Electrodynamics from Infeld-van der Waerden formalisms
In this article we will explore the spacetime phase structure inside the
Infeld-van der Waerden formalisms, showing that Maxwell's theory in this
scenario leads to an axion-like phase electrodynamics, which suggests that this
phase may originate the axion field.Comment: 15 page
Transfer of optical spectral weight in magnetically ordered superconductors
We show that, in antiferromagnetic superconductors, the optical spectral
weight transferred to low frequencies below the superconducting transition
temperature originates from energies that can be much larger than twice the
superconducting gap . This contrasts to non-magnetic superconductors,
where the optical spectrum is suppressed only for frequencies below .
In particular, we demonstrate that the superfluid condensate of the
magnetically ordered superconductor is not only due to states of the
magnetically reconstructed Fermi surface, but is enhanced by transfer of
spectral weight from the mid infrared peak generated by the spin density wave
gap. We apply our results to the iron arsenide superconductors, addressing the
decrease of the zero-temperature superfluid density in the doping regime where
magnetism coexists with unconventional superconductivity.Comment: 5 figures, 10 pages; revised versio
Extended quantum portrait of MGD black holes and information entropy
The extended minimal geometric deformation (EMGD) is employed on the fluid
membrane paradigm, to describe compact stellar objects as Bose--Einstein
condensates (BEC) consisting of gravitons. The black hole quantum portrait,
besides deriving a preciser phenomenological bound for the fluid brane tension,
is then scrutinized from the point of view of the configurational entropy. It
yields a range for the critical density of the EMGD BEC, whose configurational
entropy has global minima suggesting the configurational stability of the EMGD
BEC.Comment: 9 pages, 7 figures, matches the published versio
Numerical solution of open string field theory in Schnabl gauge
Using traditional Virasoro level-truncation computations, we evaluate
the open bosonic string field theory action up to level . Extremizing
this level-truncated potential, we construct a numerical solution for tachyon
condensation in Schnabl gauge. We find that the energy associated to the
numerical solution overshoots the expected value at level .
Extrapolating the level-truncation data for to estimate the vacuum
energies for , we predict that the energy reaches a minimum value at , and then turns back to approach asymptotically as . Furthermore, we analyze the tachyon vacuum expectation value (vev),
for which by extrapolating its corresponding level-truncation data, we predict
that the tachyon vev reaches a minimum value at , and then turns
back to approach the expected analytical result as .Comment: 37 pages, 9 figures, some typos correcte
Gap nodes induced by coexistence with antiferromagnetism in iron-based superconductors
We investigate the pairing in iron pnictides in the coexistence phase, which
displays both superconducting and antiferromagnetic orders. By solving the
pairing problem on the Fermi surface reconstructed by long-range magnetic
order, we find that the pairing interaction necessarily becomes
angle-dependent, even if it was isotropic in the paramagnetic phase, which
results in an angular variation of the superconducting gap along the Fermi
surfaces. We find that the gap has no nodes for a small antiferromagnetic order
parameter M, but may develop accidental nodes for intermediate values of M,
when one pair of the reconstructed Fermi surface pockets disappear. For even
larger M, when the other pair of reconstructed Fermi pockets is gapped by
long-range magnetic order, superconductivity still exists, but the
quasiparticle spectrum becomes nodeless again. We also show that the
application of an external magnetic field facilitates the formation of nodes.
We argue that this mechanism for a nodeless-nodal-nodeless transition explains
recent thermal conductivity measurements of hole-doped Ba_{1-x}K_xFe_2As_2.
[J-Ph. Read et.al. arXiv:1105.2232].Comment: 13 pages, 10 figures, submitted to PR
Optical and Near Infrared Study of the Cepheus E outflow, a very low excitation object
We present images and spectra of the Cepheus E (Cep E) region at both optical
and infrared wavelengths. Only the brightest region of the southern lobe of the
Cep E outflow reveals optical emission, suggesting that the extinction close to
the outflow source plays an important r\^ole in the observed difference between
the optical and IR morphologies. Cep E is a unique object since it provides a
link between the spectroscopic properties of the optical Herbig-Haro (HH)
objects and those of deeply embedded outflows.Comment: Accepted Astron. J., 8 files: paper, tables plus 6 figure
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