Comparative aspects of phytase and xylanase effects on performance, mineral digestibility, and ileal phytate degradation in broilers and turkeys

Two experiments were performed, using broilers or turkeys, each utilizing a 3 × 2 factorial arrangement, to compare their response to phytase and xylanase supplementation with growth performance, nutrient digestibility, and ileal phytate degradation as response criteria. For both experiments, 960 Ross 308 or 960 BUT 10 (0-day-old) birds were allocated to 6 treatments: (1) control diet, containing phytase at 500 FTU/kg; (2) the control diet with xylanase (16,000 BXU/kg); (3) the control diet supplemented on top with phytase (1,500 FTU/kg); (4) diet supplemented with 1,500 FTU/kg phytase and xylanase (16,000 BXU/kg); (5) the control diet supplemented with phytase (3,000 FTU/kg); and (6) diet supplemented with 3,000 FTU/kg phytase and xylanase (16,000 BXU/kg). Each treatment had 8 replicates of 20 birds each. Water and diets based on wheat, soybean meal, oilseed rape meal, and barley were available ad libitum. Body weight gain and feed intake were measured from 0 to 28 D, and feed conversion ratio (FCR) corrected for mortality was calculated. Ileal digestibility for dry matter and minerals on day 7 and 28 were analyzed in addition to levels of inositol phosphate esters (InsP6-3) and myo-inositol. Statistical comparisons were performed using ANOVA. Xylanase supplementation improved 28D FCR in broilers and turkeys. Increasing doses of phytase reduced FI and improved FCR only in broilers. In broilers, the age × phytase interaction for phosphorous digestibility showed that increasing phytase dose was more visible on day 7, than on day 28. Mineral digestibility was lower in 28-day-old turkey compared with 7-day-old turkey. InsP6 disappearance increased with increasing phytase levels in both species, with lower levels analyzed in turkeys. InsP6 disappearance was greater in younger turkeys (day 7 compared with day 28). In conclusion, although broilers and turkeys shared several similarities in their growth and nutrient utilization responses, the outcomes of the 2 trials also differed in many aspects. Whether this is because of difference in diets (InsP or Ca level) or differences between species needs further investigation

Beyond conventional factorization: Non-Hermitian Hamiltonians with radial oscillator spectrum

The eigenvalue problem of the spherically symmetric oscillator Hamiltonian is revisited in the context of canonical raising and lowering operators. The Hamiltonian is then factorized in terms of two not mutually adjoint factorizing operators which, in turn, give rise to a non-Hermitian radial Hamiltonian. The set of eigenvalues of this new Hamiltonian is exactly the same as the energy spectrum of the radial oscillator and the new square-integrable eigenfunctions are complex Darboux-deformations of the associated Laguerre polynomials.Comment: 13 pages, 7 figure

Energy efficient engine: Flight propulsion system preliminary analysis and design

The characteristics of an advanced flight propulsion system (FPS), suitable for introduction in the late 1980's to early 1990's, was more fully defined. It was determined that all goals for efficiency, environmental considerations, and economics could be met or exceeded with the possible exception of NOx emission. In evaluating the FPS, all aspects were considered including component design, performance, weight, initial cost, maintenance cost, engine system integration (including nacelle), and aircraft integration considerations. The current FPS installed specific fuel consumption was reduced 14.2% from that of the CF6-50C reference engine. When integrated into an advanced, subsonic, study transport, the FPS produced a fuel burn savings of 15 to 23% and a direct operating cost reduction of 5 to 12% depending on the mission and study aircraft characteristics relative to the reference engine

The dimerized phase of ionic Hubbard models

We derive an effective Hamiltonian for the ionic Hubbard model at half filling, extended to include nearest-neighbor repulsion. Using a spin-particle transformation, the effective model is mapped onto simple spin-1 models in two particular cases. Using another spin-particle transformation, a slightly modified model is mapped into an SU(3) antiferromagnetic Heisenberg model whose exact ground state is known to be spontaneously dimerized. From the effective models several properties of the dimerized phase are discussed, like ferroelectricity and fractional charge excitations. Using bosonization and recent developments in the theory of macroscopic polarization, we show that the polarization is proportional to the charge of the elementary excitations

Avaliação de fontes e doses de fósforo no crescimento inicial do milho.

RESUMO: O fósforo é componente vital para todos os seres vivos e é essencial para a produção agrícola. No Brasil, a maior parte dos solos agricultáveis tem baixos teores de fósforo disponível. Para atender as exigências das plantas e suprimento adequado de fósforo há a necessidade da aplicação de adubos fosfatados. Dentre as opções de fontes no mercado, os fosfatos totalmente acidulados são os usualmente comercializados. Com o aumento do uso dos fosfatos naturais reativos, a avaliação da eficiência da aplicação do fertilizante é importante no manejo da adubação fosfatada. O experimento foi realizado em casa de vegetação, utilizando um Nitossolo. O delineamento experimental empregado foi o inteiramente casualizado com os tratamentos arranjados em um fatorial 4 x 2 com quatro repetições. O objetivo do trabalho foi avaliar os efeitos de fontes e doses de fósforo no crescimento inicial do milho. A produção de matéria seca e os teores de P da parte aérea das plantas de milho aumentaram com o incremento das doses de fósforo, dependentemente da fonte de P considerada. Contudo, o Superfosfato Triplo foi mais eficiente que o fosfato de Arad, garantindo melhor nutrição e crescimento inicial das plantas de milho. ABSTRACT: Phosphorus is an essential element for all living organisms and important also for agricultural production. The content of P in most agricultural soils in Brazil is low. In order to supply the plant needs and the soil fixation, application of P fertilizer is required. Among the various options of P fertilizers in the market, the totally acidified phosphates are usually commercialized. The evaluation of the efficiency of the reactive natural phosphates as P fertilizers is important due to the increase of the utilization of cheaper sources of natural P. The experiment was carried out in green house, using a Nitossolo. The experimental design used was complete randomized design, with the treatments in a 4x2 factorial arrangement, and four replications. The objective of the experiment was to evaluate the effects of sources and rates of P on the growth of corn. The production of dry matter and the content of P on the corn leave and stalks (above ground corn parts) increased as rates of P increased, regardless the P sources tested. However, the Triple Super Phosphate was more efficient compared with Arad phosphate, providing better nutrition and initial growth of corn plants

Exactly Solvable Hydrogen-like Potentials and Factorization Method

A set of factorization energies is introduced, giving rise to a generalization of the Schr\"{o}dinger (or Infeld and Hull) factorization for the radial hydrogen-like Hamiltonian. An algebraic intertwining technique involving such factorization energies leads to derive $n$-parametric families of potentials in general almost-isospectral to the hydrogen-like radial Hamiltonians. The construction of SUSY partner Hamiltonians with ground state energies greater than the corresponding ground state energy of the initial Hamiltonian is also explicitly performed.Comment: LaTex file, 21 pages, 2 PostScript figures and some references added. To be published in J. Phys. A: Math. Gen. (1998

N, N-Dimethyl Amine Linked To Triphenylamine (TPA): A Promising Co-Donor Moiety In Organic Dyes And Their Push-Pull Behavior

The push-pull behavior of novel codonor-donor dyes bearing a N,N-dimethyl amine linked covalently to a triphenylamine group through a vinyl bridge was studied by experimental (electrochemical and spectroscopic) analysis. These dyes were obtained by conventional reactions using a convergent synthesis method. An intra-molecular charge transfer process was observed in the electronic structure of these compounds

Generalized Coherent States as Preferred States of Open Quantum Systems

We investigate the connection between quasi-classical (pointer) states and generalized coherent states (GCSs) within an algebraic approach to Markovian quantum systems (including bosons, spins, and fermions). We establish conditions for the GCS set to become most robust by relating the rate of purity loss to an invariant measure of uncertainty derived from quantum Fisher information. We find that, for damped bosonic modes, the stability of canonical coherent states is confirmed in a variety of scenarios, while for systems described by (compact) Lie algebras stringent symmetry constraints must be obeyed for the GCS set to be preferred. The relationship between GCSs, minimum-uncertainty states, and decoherence-free subspaces is also elucidated.Comment: 5 pages, no figures; Significantly improved presentation, new derivation of invariant uncertainty measure via quantum Fisher information added

The supersymmetric modified Poschl-Teller and delta-well potentials

New supersymmetric partners of the modified Poschl-Teller and the Dirac's delta well potentials are constructed in closed form. The resulting one-parametric potentials are shown to be interrelated by a limiting process. The range of values of the parameters for which these potentials are free of singularities is exactly determined. The construction of higher order supersymmetric partner potentials is also investigated.Comment: 20 pages, LaTeX file, 4 eps figure