313 research outputs found
Biologically active peptides of meat and meat product proteins: a review. Part 2. Functionality of meat bioactive peptides
Biologically active peptides (BAP) are regarded as the main products of protein hydrolysis. BAP activity depends on the amino acid sequence molecular weight and chain length, type and charge of an amino acid at the N-terminus and C-terminus, hydrophobic and hydrophilic properties, spatial structure. They positively influence many systems of the human body, including the blood circulatory, nervous, immune, gastrointestinal and other systems. The health-improving effect of bioactive peptides is formed due to their antioxidant, antihypertensive, antithrombotic, immunomodulatory, antimicrobial, anti-allergic, opioid, anti-inflammatory, hypocholesterolemic and anticancer properties. Angiotensin-I-converting enzyme (ACE) inhibitory peptides are most studied due to their effect on blood pressure regulation. Unlike synthetic preparations, biologically active peptides do not have side effects and, therefore, can be used as their alternative. There is a growing commercial interest in peptides generated from meat proteins is in the context of health saving functional foods. The paper describes prospects, pros and cons of using bioactive peptides as functional food ingredients and biologically active food additives
Soft Contributions to Hard Pion Photoproduction
Hard, or high transverse momentum, pion photoproduction can be a tool for
probing the parton structure of the beam and target. We estimate the soft
contributions to this process, with an eye toward delineating the region where
perturbatively calculable processes dominate. Our soft process estimate is
based on vector meson dominance and data based parameterizations of
semiexclusive hadronic cross sections. We find that soft processes dominate in
single pion photoproduction somewhat past 2 GeV transverse momentum at a few
times 10 GeV incoming energy. The recent polarization asymmetry data is
consistent with the perturbative asymmetry being diluted by polarization
insensitive soft processes. Determining the polarized gluon distribution using
hard pion photoproduction appears feasible with a few hundred GeV incoming
energy (in the target rest frame).Comment: 6 pages, 5 figure
New Experimental limit on Optical Photon Coupling to Neutral, Scalar Bosons
We report on the first results of a sensitive search for scalar coupling of
photons to a light neutral boson in the mass range of approximately 1.0
milli-electron volts and coupling strength greater than 10 GeV using
optical photons. This was a photon regeneration experiment using the "light
shining through a wall" technique in which laser light was passed through a
strong magnetic field upstream of an optical beam dump; regenerated laser light
was then searched for downstream of a second magnetic field region optically
shielded from the former. Our results show no evidence for scalar coupling in
this region of parameter space.Comment: pdf-file, 10 pages, 4 figures, submitted to Physical Review Letter
Radiative Correction to the Transferred Polarization in Elastic Electron-Proton Scattering
Model independent radiative correction to the recoil proton polarization for
the elastic electron-proton scattering is calculated within method of electron
structure functions. The explicit expressions for the recoil proton
polarization are represented as a contraction of the electron structure and the
hard part of the polarization dependent contribution into cross-section. The
calculation of the hard part with first order radiative correction is
performed. The obtained representation includes the leading radiative
corrections in all orders of perturbation theory and the main part of the
second order next-to-leading ones. Numerical calculations illustrate our
analytical results.Comment: 14 pages, 4 figure
Transversity and Transverse Spin in Nucleon Structure through SIDIS at Jefferson Lab
The JLab 12 GeV upgrade with a proposed solenoid detector and the CLAS12
detector can provide the granularity and three-dimensional kinematic coverage
in longitudinal and transverse momentum, , with to precisely measure the leading twist
chiral-odd and -odd quark distribution and fragmentation functions in SIDIS.
The large experimental reach of these detectors with a 12 GeV CEBAF at JLab
makes it {\em ideal} to obtain precise data on the {\em valence-dominated}
transversity distribution function and to access the tensor charge.Comment: 7 Pages, 2 figures. Summary of the working group on Transversity and
Transverse Spin Physics, from the workshop, "Inclusive and Semi-Inclusive
Spin Physics with High Luminosity and LargeAcceptance at 11 GeV", Thomas
Jefferson National Accelerator Facility (JLAB), December 13-14, 2006,
Jefferson Lab, Newport News, VA USA. Serves as input for the Nuclear Physics
Long Range Plan on QCD and Hadron Physic
New empirical fits to the proton electromagnetic form factors
Recent measurements of the ratio of the elastic electromagnetic form factors
of the proton, G_Ep/G_Mp, using the polarization transfer technique at
Jefferson Lab show that this ratio decreases dramatically with increasing Q^2,
in contradiction to previous measurements using the Rosenbluth separation
technique. Using this new high quality data as a constraint, we have reanalyzed
most of the world e-p elastic cross section data. In this paper, we present a
new empirical fit to the reanalyzed data for the proton elastic magnetic form
factor in the region 0 < Q^2 < 30 GeV^2. As well, we present an empirical fit
to the proton electromagnetic form factor ratio, G_Ep/G_Mp, which is valid in
the region 0.1 < Q^2 < 6 GeV^2
OVI Asymmetry and an Accelerated Outflow in an Obscured Seyfert: FUSE and HST STIS Spectroscopy of Markarian533
We present far-ultraviolet spectra of the Seyfert2 galaxy Mrk533 obtained
with FUSE. These spectra show narrow asymmetrical OVI 1032,1038 emission lines
with stronger wings shortward of the peak wavelength, but the degree of
asymmetry of these wings in velocity is much lower than that of the wings of
the lines of lower ionization. In the combined OVI profile there are marginal
indications of local absorptions in the outflow. The CIII 977 line is seen
weakly with a similar profile, but with very low signal to noise. These FUV
spectra are among the first for a Seyfert of type2, i.e., a purportedly
obscured Seyfert. The HST STIS spectral image of Mrk533 allows delineation of
the various components of the outflow, and we infer that the outflow is
accelerated. We discuss the results in terms of nuclear geometry and
kinematics.Comment: 19 pages, 5 figures, including 1 colour figure. Accepted in Ap
A Complete Version of the Glauber Theory for Elementary Atom - Target Atom Scattering and Its Approximations
A general formalism of the Glauber theory for elementary atom (EA) - target
atom (TA) scattering is developed. A second-order approximation of its complete
version is considered in the framework of the optical-model perturbative
approach. A `potential' approximation of a second-order optical model is
formulated neglecting the excitation effects of the TA. Its accuracy is
evaluated within the second-order approximation for the complete version of the
Glauber EA-TA scattering theory.Comment: PDFLaTeX, 10 pages, no figures; an updated versio
From the Feynman-Schwinger representation to the non-perturbative relativistic bound state interaction
We write the 4-point Green function in QCD in the Feynman-Schwinger
representation and show that all the dynamical information are contained in the
Wilson loop average. We work out the QED case in order to obtain the usual
Bethe-Salpeter kernel. Finally we discuss the QCD case in the non-perturbative
regime giving some insight in the nature of the interaction kernel.Comment: 25 pages, RevTex, 3 figures included, typos corrected, to appear in
Phys. Rev. D 5
Radiative corrections to polarization observables in elastic electron-deuteron scattering in leptonic variables
The model--independent QED radiative corrections to polarization observables
in elastic scattering of unpolarized and longitudinally--polarized electron
beam by the deuteron target have been calculated in leptonic variables. The
experimental setup when the deuteron target is arbitrarily polarized is
considered and the procedure for applying derived results to the vector or
tensor polarization of the recoil deuteron is discussed. The basis of the
calculations consists of the account for all essential Feynman diagrams which
results in the form of the Drell-Yan representation for the cross-section and
use of the covariant parametrization of the deuteron polarization state. The
numerical estimates of the radiative corrections are given for the case when
event selection allows the undetected particles (photons and electron-positron
pairs) and the restriction on the lost invariant mass is used.Comment: 43 pages,3 figures. To be published in ZhTEF. revised 14.02.2012.
arXiv admin note: text overlap with arXiv:nucl-ex/0002003 by other author
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