770 research outputs found
Effects of dietary probiotic and prebiotic supplementation on growth performance and serum IgG concentration of broilers
This study was conducted to investigate the effects of probiotic and/or prebiotic supplementation on growth performance and serum IgG concentrations in broilers. One thousand two hundred one-day old Ross-308 broiler chicks of mixed sex were randomly divided into four treatment groups of 300 birds each. The treatments were: Starter diets: 1) Unsupplemented control diet; 2) Probiotic (Bio-Plus 2B® 0.05%); 3) Prebiotic (Bio-Mos® 0.2%); 4) Probiotic and Prebiotic mixture (Bio-Plus 2B® 0.05% and Bio-Mos® 0.2%). The grower diets were: 1) Control with no supplements; 2) Probiotic (Bio-Plus 2B® 0.05%); 3) Prebiotic (Bio-Mos® 0.1%); 4) Probiotic and Prebiotic mixture (Bio-Plus 2B® 0.05% and Bio-Mos® 0.1%). Each treatment group was further sub-divided into five replicates of 60 birds per replicate. The chicks were fed the broiler starter diet for the first 21 d and the broiler grower diet between days 22 and 42. Dietary probiotic and/or prebiotic supplementation did not significantly affect body weight, body weight gain, feed intake, carcass weight, carcass yield or concentration of immunoglobulin (IgG) in the serum. However, feed conversion ratio was improved significantly in the supplemented treatments compared to the unsupplemented control. Probiotic and/or prebiotic supplementation did not significantly affect any of the examined parameters except for an improved feed conversion ratio. Keywords: Probiotic, prebiotic, broilers, performanceSouth African Journal of Animal Science Vol. 38 (1) 2008: pp. 21-2
A general moment NRIXS approach to the determination of equilibrium Fe isotopic fractionation factors: application to goethite and jarosite
We measured the reduced partition function ratios for iron isotopes in
goethite FeO(OH), potassium-jarosite KFe3(SO4)2(OH)6, and hydronium-jarosite
(H3O)Fe3(SO4)2(OH)6, by Nuclear Resonant Inelastic X-Ray Scattering (NRIXS,
also known as Nuclear Resonance Vibrational Spectroscopy -NRVS- or Nuclear
Inelastic Scattering -NIS) at the Advanced Photon Source. These measurements
were made on synthetic minerals enriched in 57Fe. A new method (i.e., the
general moment approach) is presented to calculate {\beta}-factors from the
moments of the NRIXS spectrum S(E). The first term in the moment expansion
controls iron isotopic fractionation at high temperature and corresponds to the
mean force constant of the iron bonds, a quantity that is readily measured and
often reported in NRIXS studies.Comment: 38 pages, 2 tables, 8 figures. In press at Geochimica et Cosmochimica
Acta. Appendix C contains new derivations relating the moments of the iron
PDOS to the moments of the excitation probability function measured in
Nuclear Resonant Inelastic X-ray Scatterin
Reentrant valence transition in EuO at high pressures: beyond the bond-valence model
The pressure-dependent relation between Eu valence and lattice structure in
model compound EuO is studied with synchrotron-based x-ray spectroscopic and
diffraction techniques. Contrary to expectation, a 7% volume collapse at
45 GPa is accompanied by a reentrant Eu valence transition into a
\emph{lower} valence state. In addition to highlighting the need for probing
both structure and electronic states directly when valence information is
sought in mixed-valent systems, the results also show that widely used
bond-valence methods fail to quantitatively describe the complex electronic
valence behavior of EuO under pressure.Comment: 5 pages, 4 figure
Influence of Magnetism on Phonons in CaFe2As2 Via Inelastic X-ray Scattering
In the iron pnictides, the strong sensitivity of the iron magnetic moment to
the arsenic position suggests a significant relationship between phonons and
magnetism. We measured the phonon dispersion of several branches in the high
temperature tetragonal phase of CaFe2As2 using inelastic x-ray scattering on
single-crystal samples. These measurements were compared to ab initio
calculations of the phonons. Spin polarized calculations imposing the
antiferromagnetic order present in the low temperature orthorhombic phase
dramatically improve agreement between theory and experiment. This is discussed
in terms of the strong antiferromagnetic correlations that are known to persist
in the tetragonal phase.Comment: 4 pages, 3 figures; added additional information and references about
spin fluctuation
Improved Bounds on Quantum Learning Algorithms
In this article we give several new results on the complexity of algorithms
that learn Boolean functions from quantum queries and quantum examples.
Hunziker et al. conjectured that for any class C of Boolean functions, the
number of quantum black-box queries which are required to exactly identify an
unknown function from C is ,
where is a combinatorial parameter of the class C. We
essentially resolve this conjecture in the affirmative by giving a quantum
algorithm that, for any class C, identifies any unknown function from C using
quantum black-box
queries.
We consider a range of natural problems intermediate between the exact
learning problem (in which the learner must obtain all bits of information
about the black-box function) and the usual problem of computing a predicate
(in which the learner must obtain only one bit of information about the
black-box function). We give positive and negative results on when the quantum
and classical query complexities of these intermediate problems are
polynomially related to each other.
Finally, we improve the known lower bounds on the number of quantum examples
(as opposed to quantum black-box queries) required for -PAC
learning any concept class of Vapnik-Chervonenkis dimension d over the domain
from to . This new lower bound comes
closer to matching known upper bounds for classical PAC learning.Comment: Minor corrections. 18 pages. To appear in Quantum Information
Processing. Requires: algorithm.sty, algorithmic.sty to buil
Magnetism dependent phonon anomaly in LaFeAsO observed via inelastic x-ray scattering
The phonon dispersion was measured at room temperature along (0,0,L) in the
tetragonal phase of LaFeAsO using inelastic x-ray scattering. Spin-polarized
first-principles calculations imposing various types of antiferromagnetic order
are in better agreement with the experimental results than nonmagnetic
calculations, although the measurements were made well above the magnetic
ordering temperature, T_N. Splitting observed between two A_{1g} phonon modes
at 22 and 26 meV is only observed in spin-polarized calculations.
Magneto-structural effects similar to those observed in the AFe_2As_2 materials
are confirmed present in LaFeAsO. The presence of Fe-spin is necessary to find
reasonable agreement of the calculations with the measured spectrum well above
T_N. On-site Fe and As force constants show significant softening compared to
nonmagnetic calculations, however an investigation of the real-space force
constants associates the magnetoelastic coupling with a complex renormalization
instead of softening of a specific pairwise force.Comment: 7 pages, 4 figure
Kritik (Kriz) Dönem Enflasyon Hesaplamalarında Bulanık Regresyon Tahminlemesi
Inflation targeting is defined as the determination of an acceptable inflation rate for a specific period of time by considering the general variables and data of inflation and also as the implementation of monetary policies in such a way that they can reach predetermined rates. Accurate inflation estimates are needed to reach the targets. Acquiring the estimations accurately leads to correct decisions. Fuzzy regression method is a method that gives successful results when classical regression estimates cannot be obtained. During the periods when Turkey undergoes economical crisis, it is difficult to make accurate inflation estimates. More reliable estimates can be made with the help of fuzzy regression models. In this study, inflation estimates were obtained through fuzzy regression model estimation and the results were interpreted.Enflasyon hedeflemesi, ekonominin genel değişkenlerinin ve verilerinin dikkate alınarak belirli bir dönem için kabul edilebilir bir enflasyon oranının belirlenmesi ve para politikalarının belirlenen orana ulaşacak şekilde yürütülmesi olarak tanımlanmaktadır. Hedeflere ulaşabilmek için güçlü enflasyon tahminlerine gereksinim duyulmaktadır. Öngörülerin doğru bir şekilde elde edilmesi daha doğru kararlara neden olmaktadır. Bulanık regresyon yöntemi, klasik regresyon varsayımlarının sağlanmadığı durumlarda başarılı sonuçlar veren bir yöntemdir. Türkiye’nin ekonomik kriz yaşadığı dönemlerde güçlü enflasyon tahminleri yapmak oldukça zor olmaktadır. Bulanık regresyon modelleri yardımıyla daha güvenilir tahminler elde edilebilmektedir. Bu çalışmada, bulanık regresyon model tahminlemesi ile kritik dönemler için enflasyon tahminleri elde edilmiş ve sonuçlar yorumlanmıştır
Kritik (Kriz) Dönem Enflasyon Hesaplamalarında Bulanık Regresyon Tahminlemesi
Inflation targeting is defined as the determination of an acceptable inflation rate for a specific period of time by considering the general variables and data of inflation and also as the implementation of monetary policies in such a way that they can reach predetermined rates. Accurate inflation estimates are needed to reach the targets. Acquiring the estimations accurately leads to correct decisions. Fuzzy regression method is a method that gives successful results when classical regression estimates cannot be obtained. During the periods when Turkey undergoes economical crisis, it is difficult to make accurate inflation estimates. More reliable estimates can be made with the help of fuzzy regression models. In this study, inflation estimates were obtained through fuzzy regression model estimation and the results were interpreted.Enflasyon hedeflemesi, ekonominin genel değişkenlerinin ve verilerinin dikkate alınarak belirli bir dönem için kabul edilebilir bir enflasyon oranının belirlenmesi ve para politikalarının belirlenen orana ulaşacak şekilde yürütülmesi olarak tanımlanmaktadır. Hedeflere ulaşabilmek için güçlü enflasyon tahminlerine gereksinim duyulmaktadır. Öngörülerin doğru bir şekilde elde edilmesi daha doğru kararlara neden olmaktadır. Bulanık regresyon yöntemi, klasik regresyon varsayımlarının sağlanmadığı durumlarda başarılı sonuçlar veren bir yöntemdir. Türkiye’nin ekonomik kriz yaşadığı dönemlerde güçlü enflasyon tahminleri yapmak oldukça zor olmaktadır. Bulanık regresyon modelleri yardımıyla daha güvenilir tahminler elde edilebilmektedir. Bu çalışmada, bulanık regresyon model tahminlemesi ile kritik dönemler için enflasyon tahminleri elde edilmiş ve sonuçlar yorumlanmıştır
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