Quantum corrections to the mass of self-dual vortices

The mass shift induced by one-loop quantum fluctuations on self-dual ANO vortices is computed using heat kernel/generalized zeta function regularization methods.Comment: 4 pages RevTex, version to appear in Physical Review

One-loop mass shift formula for kinks and self-dual vortices

A formula is derived that allows us to compute one-loop mass shifts for kinks and self-dual Abrikosov-Nielsen-Olesen vortices. The procedure is based in canonical quantization and heat kernel/zeta function regularization methods.Comment: LaTex file, 8 pages, 1 figure . Based on a talk given by J. M. G. at the 7th Workshop on Quantum Field Theory under the Influence of External Conditions (QFEXT05), Barcelona, Spain. Minor corrections. Version to appear in Journal of Physics

Quantum fluctuations around low-dimensional topological defects

In these Lectures a method is described to analyze the effect of quantum fluctuations on topological defect backgrounds up to the one-loop level. The method is based on the spectral heat kernel/zeta function regularization procedure, and it is first applied to various types of kinks arising in several deformed linear and non-linear sigma models with different numbers of scalar fields. In the second part, the same conceptual framework is constructed for the topological solitons of the planar semilocal Abelian Higgs model, built from a doublet of complex scalar fields and one U(1) gauge field.Comment: 63 pages, 14 figures, expanded version of two lectures given by J.M.G. in 5th International School on Field Theory and Gravitation, Cuiaba, Brazi

Quantum oscillations of self-dual Abrikosov-Nielsen-Olesen vortices

The mass shift induced by one-loop quantum fluctuations on self-dual ANO vortices is computed using heat kernel/generalized zeta function regularization methods. The quantum masses of super-imposed multi-vortices with vorticity lower than five are given. The case of two separate vortices with a quantum of magnetic flux is also discussed.Comment: RevTex, 13 pages, 4 figures, 7 tables. Minor corrections. Version to appear in Physical Review

Changing shapes: adiabatic dynamics of composite solitary waves

We discuss the solitary wave solutions of a particular two-component scalar field model in two-dimensional Minkowski space. These solitary waves involve one, two or four lumps of energy. The adiabatic motion of these composite non-linear non-dispersive waves points to variations in shape.Comment: 21 pages, 15 figures. To appear in Physica D: Nonlinear Phenomen

Type of grinding of the main cereal of the diet affects production of brown egg-laying hens

The influence of method of grinding of the cereal of the diet on production and egg quality was studied in 420 Hy-line brown egg-laying hens. The design was completely randomized with six treatments arranged as a 3 × 2 factorial with three cereals (barley, dented maize and soft wheat) and two grinding procedures (hammer mill vs. roller mill). Each treatment was replicated seven times and the experimental unit was an enriched cage with ten hens. Production was recorded every four weeks from 24 to 59 weeks of age and egg quality was measured at 40 and 56 weeks of age. For the entire experiment, feed intake was higher in hens fed wheat or maize than in hens fed barley (110.8 and 110.7 vs. 109.7 g/d; P = 0.014) but most of the differences were observed when the cereal was roller milled (P = 0.009 for the interaction). Also, egg production was similar for the three diets when the cereal was hammer milled but tended to be lower for the barley than for the wheat or maize diets when the cereal was roller milled (P = 0.09 for the interaction). None of the other productive or egg quality traits was affected by dietary treatment. We conclude that roller mills are useful to grind low fiber cereals, such as maize or wheat. However, the use of the roller mill might not be adequate when barley is the main cereal in diets for egg-laying hens

Spectral Flow of Vortex Shape Modes over the BPS 2-Vortex Moduli Space

The flow of shape eigenmodes of the small fluctuation operator around BPS 2-vortex solutions is calculated, as a function of the intervortex separation $2d$. For the rotationally-invariant 2-vortex, with $d = 0$, there are three discrete modes; the lowest is non-degenerate and the upper two are degenerate. As $d$ increases, the degeneracy splits, with one eigenvalue increasing and entering the continuous spectrum, and the other decreasing and asymptotically coalescing with the lowest eigenvalue, where they jointly become the eigenvalue of the 1-vortex radial shape mode. The behaviour of the eigenvalues near $d=0$ is clarified using a perturbative analysis, and also in light of the 2-vortex moduli space geometry.Comment: 12 pages, 8 figure

On the semiclassical mass of S2{\mathbb S}^2-kinks

One-loop mass shifts to the classical masses of stable kinks arising in a massive non-linear ${\mathbb S}^2$-sigma model are computed. Ultraviolet divergences are controlled using the heat kernel/zeta function regularization method. A comparison between the results achieved from exact and high-temperature asymptotic heat traces is analyzed in depth.Comment: RevTex file, 15 pages, 2 figures. Version to appear in Journal of Physics

Efecto del cereal base y del programa de alimetnación sobre los parámetros productivos en pollitas de 1 a 17 semanas de edad.

Maíz y trigo son los cereales más utilizados en piensos para aves. El maíz tiene menos proteína (7,7 vs. 11,2%) pero más energía (3.260 vs. 3.150 Kcal EMAn/kg) que el trigo (FEDNA, 2010). Además, el valor nutricional es más variable para el trigo que para el maíz Kim et al., 1976; Mollah et al., 1983). En pollos y en ponedoras, numerosos trabajos indican que el trigo puede ser utilizado en sustitución del maíz como ingrediente principal del pienso Mathlouthi et al., 2002; Carré et al., 2002; Lázaro et al., 2003; Pérez-Bonilla et al., 2011). Frikha et al. (2009), observaron que las pollitas alimentadas con maíz tenían mayores GMD pero IC similares que las pollitas alimentadas con trigo. La presentación del pienso afecta los rendimientos productivos en avicultura. Amerah et al. (2007) mostraron un aumento de la GMD y una mejora del IC en pollos alimentados con gránulos en comparación con los alimentados con harina. Gous y Morris (2001) observaron que pollitas alimentadas con migas de 1 a 4 sem y con gránulo de 5 a 20 sem de edad, consumieron 2% menos pienso pero pesaron un 6% más que las alimentadas con harina durante toda la recría. Frikha et al. (2009) observaron un incremento en la GMD en las pollitas alimentadas con gránulo respecto a las pollitas alimentadas con harina. Los autores no han encontrado información alguna sobre el efecto de alternar la presentación del pienso (bien en harina, bien en miga) durante las distintas etapas del periodo de recría (0-5, 5-10 y 10-17 sem de vida) sobre la productividad de las aves. El presente trabajo estudió la influencia del cereal base del pienso y de cambios en la presentación del mismo durante las 3 fases del programa de alimentación en recría sobre los parámetros productivos en pollitas de 1 a 17 semanas de edad