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Comparison of different dietary sources of n-3 polyunsaturated fatty acids on immune response in broiler chickens
The study aims to research the effects of varied dietary sources of n-3 polyunsaturated fatty acids (PUFA) on the immune response in broiler chickens with stress on natural killer (NK) cell activity. Diets supplemented with one of the four sources of n-3 PUFA: linseed oil-, echium oil-, fish oil (FO) or algal biomass-enriched diets at levels of 18, 18, 50 and 15 g/kg fresh weight, were provided for one-d-old male Ross 308 broilers, totaling 340 in number, until they were slaughtered. The analyses included total lipid profile using gas chromatography (GC) for plasma, spleen, thymus, and blood. Additionally, NK cell activity and cell proliferation were investigated for thymocytes and splenocytes. The results indicated that the source of n-3 PUFA had a strong influence on fatty acid composition across all tissues. NK activity was highest in splenocytes and PBMCs from broilers fed linseed oil, followed by those fed algal biomass or echium oil, and lowest for those from broilers fed FO. The proliferative response of lymphocytes from algal biomass-fed chickens tended to be the highest, followed by those fed linseed oil in most cases. Lymphocytes from chickens fed fish oil showed the lowest proliferative response. These results could mean that a docosahexaenoic acid (DHA)-rich algal product might enrich chicken meat with n-3 PUFA without significant damaging effects on chicken immunity
U-Pb geochronology of the El Jadida rhyolite and relation to possible Lower Cambrian recycling (Coastal block, Moroccan Meseta).
The El Jadida (Mazagan) dome, whose existence was reported as early as 1934 by
Yovanovitch and Freys, constitutes one of the first outcrops of the Moroccan Meseta where
the Precambrian (PIII?)-Paleozoic (Lower Cambrian?) boundary was established (Gigout,
1951; Cornée et al., 1984). Since then, it is listed as one of the few locations where the
basement of the Moroccan Variscan belt can be observed (Hoepffner et al.. 2005; Michard et
al., 2010).Despite, the absence of geochronological and biostratigraphic precise data to
constrain the time interval recorded here, there are stratigraphic similarities that allow a
correlation with the Ediacaran-Cambrian geological record of Anti-Atlas belt (Cornée et al.,
1984). In this study, we developed a petrographic, geochemical and U-Pb geochronological
study using zircon extracted from: (i) the El Jadida rhyolite with the aim of characterizing the magma source and estimate the age of crystallization; (ii) a microbreccia sampled at the base
of the El Jadida Dolomitic Formation for determining provenance
Spectral characteristics for a spherically confined -1/r + br^2 potential
We consider the analytical properties of the eigenspectrum generated by a
class of central potentials given by V(r) = -a/r + br^2, b>0. In particular,
scaling, monotonicity, and energy bounds are discussed. The potential is
considered both in all space, and under the condition of spherical confinement
inside an impenetrable spherical boundary of radius R. With the aid of the
asymptotic iteration method, several exact analytic results are obtained which
exhibit the parametric dependence of energy on a, b, and R, under certain
constraints. More general spectral characteristics are identified by use of a
combination of analytical properties and accurate numerical calculations of the
energies, obtained by both the generalized pseudo-spectral method, and the
asymptotic iteration method. The experimental significance of the results for
both the free and confined potential V(r) cases are discussed.Comment: 16 pages, 4 figure
Intensidade do mofo-branco do feijoeiro em plantio convencional e direto sob diferentes lâminas d'água.
Specific heat amplitude ratios for anisotropic Lifshitz critical behaviors
We determine the specific heat amplitude ratio near a -axial Lifshitz
point and show its universal character. Using a recent renormalization group
picture along with new field-theoretical -expansion techniques,
we established this amplitude ratio at one-loop order. We estimate the
numerical value of this amplitude ratio for and . The result is in
very good agreement with its experimental measurement on the magnetic material
. It is shown that in the limit it trivially reduces to the
Ising-like amplitude ratio.Comment: 8 pages, RevTex, accepted as a Brief Report in Physical Review
Solvable Systems of Linear Differential Equations
The asymptotic iteration method (AIM) is an iterative technique used to find
exact and approximate solutions to second-order linear differential equations.
In this work, we employed AIM to solve systems of two first-order linear
differential equations. The termination criteria of AIM will be re-examined and
the whole theory is re-worked in order to fit this new application. As a result
of our investigation, an interesting connection between the solution of linear
systems and the solution of Riccati equations is established. Further, new
classes of exactly solvable systems of linear differential equations with
variable coefficients are obtained. The method discussed allow to construct
many solvable classes through a simple procedure.Comment: 13 page
Bulk and Boundary Critical Behavior at Lifshitz Points
Lifshitz points are multicritical points at which a disordered phase, a
homogeneous ordered phase, and a modulated ordered phase meet. Their bulk
universality classes are described by natural generalizations of the standard
model. Analyzing these models systematically via modern
field-theoretic renormalization group methods has been a long-standing
challenge ever since their introduction in the middle of the 1970s. We survey
the recent progress made in this direction, discussing results obtained via
dimensionality expansions, how they compare with Monte Carlo results, and open
problems. These advances opened the way towards systematic studies of boundary
critical behavior at -axial Lifshitz points. The possible boundary critical
behavior depends on whether the surface plane is perpendicular to one of the
modulation axes or parallel to all of them. We show that the semi-infinite
field theories representing the corresponding surface universality classes in
these two cases of perpendicular and parallel surface orientation differ
crucially in their Hamiltonian's boundary terms and the implied boundary
conditions, and explain recent results along with our current understanding of
this matter.Comment: Invited contribution to STATPHYS 22, to be published in the
Proceedings of the 22nd International Conference on Statistical Physics
(STATPHYS 22) of the International Union of Pure and Applied Physics (IUPAP),
4--9 July 2004, Bangalore, Indi
Variational analysis for a generalized spiked harmonic oscillator
A variational analysis is presented for the generalized spiked harmonic
oscillator Hamiltonian operator H, where H = -(d/dx)^2 + Bx^2+ A/x^2 +
lambda/x^alpha, and alpha and lambda are real positive parameters. The
formalism makes use of a basis provided by exact solutions of Schroedinger's
equation for the Gol'dman and Krivchenkov Hamiltonian (alpha = 2), and the
corresponding matrix elements that were previously found. For all the discrete
eigenvalues the method provides bounds which improve as the dimension of the
basis set is increased. Extension to the N-dimensional case in arbitrary
angular-momentum subspaces is also presented. By minimizing over the free
parameter A, we are able to reduce substantially the number of basis functions
needed for a given accuracy.Comment: 15 pages, 1 figur
Anomalous dimensions and phase transitions in superconductors
The anomalous scaling in the Ginzburg-Landau model for the superconducting
phase transition is studied. It is argued that the negative sign of the
exponent is a consequence of a special singular behavior in momentum space. The
negative sign of comes from the divergence of the critical correlation
function at finite distances. This behavior implies the existence of a Lifshitz
point in the phase diagram. The anomalous scaling of the vector potential is
also discussed. It is shown that the anomalous dimension of the vector
potential has important consequences for the critical dynamics in
superconductors. The frequency-dependent conductivity is shown to obey the
scaling . The prediction is
obtained from existing Monte Carlo data.Comment: RevTex, 20 pages, no figures; small changes; version accepted in PR
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