145 research outputs found
The role of a holding company and management structure in it
This article is about the role played by holding companies in the activities of their subsidiaries. It considers in detail the question of the choice of the organizational structure for a particular type of holding. The types of integrated holdings and their features. Are described we also consider the situation of the development of holdings and identify key areas for its development.Данная статья о том, какую роль играю холдинговые компании в деятельности своих дочерних предприятий. В ней детально рассматривается вопрос о выборе организационной структуры для определенного типа холдинга. Рассмотрены типы интегрированных холдингов и их особенности. А так же рассмотрена ситуация о развитии холдингов и выявлены основные направления для его развития
Перспективи розвитку медичної освіти студентів-іноземців під час вивчення загальної хірургії та підвищення ефективності засвоєння базових теоретичних знань і практичних навичок
Перспективи розвитку медичної освіти студентів-іноземців під час вивчення загальної хірургії та підвищення ефективності засвоєння базових теоретичних знань і практичних навичо
Magnetic-inclination effects in the spectral resonance structure of the ionospheric Alfvén resonator
The -dependence of the generalised Gerasimov-Drell-Hearn integral for the deuteron, proton and neutron
The Gerasimov-Drell-Hearn (GDH) sum rule connects the anomalous contribution
to the magnetic moment of the target nucleus with an energy-weighted integral
of the difference of the helicity-dependent photoabsorption cross sections. The
data collected by HERMES with a deuterium target are presented together with a
re-analysis of previous measurements on the proton. This provides a measurement
of the generalised GDH integral covering simultaneously the nucleon-resonance
and the deep inelastic scattering regions. The contribution of the
nucleon-resonance region is seen to decrease rapidly with increasing . The
DIS contribution is sizeable over the full measured range, even down to the
lowest measured . As expected, at higher the data are found to be in
agreement with previous measurements of the first moment of . From data on
the deuteron and proton, the GDH integral for the neutron has been derived and
the proton--neutron difference evaluated. This difference is found to satisfy
the fundamental Bjorken sum rule at GeV.Comment: 12 pages, 10 figure
Evidence for Quark-Hadron Duality in the Proton Spin Asymmetry
Spin-dependent lepton-nucleon scattering data have been used to investigate
the validity of the concept of quark-hadron duality for the spin asymmetry
. Longitudinally polarised positrons were scattered off a longitudinally
polarised hydrogen target for values of between 1.2 and 12 GeV and
values of between 1 and 4 GeV. The average double-spin asymmetry in
the nucleon resonance region is found to agree with that measured in
deep-inelastic scattering at the same values of the Bjorken scaling variable
. This finding implies that the description of in terms of quark
degrees of freedom is valid also in the nucleon resonance region for values of
above 1.6 GeV.Comment: 5 pages, 1 eps figure, table added, new references added, in print in
Phys. Rev. Let
Exclusive Leptoproduction of rho^0 Mesons from Hydrogen at Intermediate Virtual Photon Energies
Measurements of the cross section for exclusive virtual-photoproduction of
rho^0 mesons from hydrogen are reported. The data were collected by the HERMES
experiment using 27.5 GeV positrons incident on a hydrogen gas target in the
HERA storage ring. The invariant mass W of the photon-nucleon system ranges
from 4.0 to 6.0 GeV, while the negative squared four-momentum Q^2 of the
virtual photon varies from 0.7 to 5.0 GeV^2. The present data together with
most of the previous data at W > 4 GeV are well described by a model that
infers the W-dependence of the cross section from the dependence on the Bjorken
scaling variable x of the unpolarized structure function for deep-inelastic
scattering. In addition, a model calculation based on Off-Forward Parton
Distributions gives a fairly good account of the longitudinal component of the
rho^0 production cross section for Q^2 > 2 GeV^2.Comment: 10 pages, 6 embedded figures, LaTeX for SVJour(epj) document class.
Revisions: curves added to Fig. 1, several clarifications added to tex
Double-Spin Asymmetry in the Cross Section for Exclusive rho^0 Production in Lepton-Proton Scattering
Evidence for a positive longitudinal double-spin asymmetry = 0.24
+-0.11 (stat) +-0.02 (syst) in the cross section for exclusive diffractive
rho^0(770) vector meson production in polarised lepton-proton scattering was
observed by the HERMES experiment. The longitudinally polarised 27.56 GeV HERA
positron beam was scattered off a longitudinally polarised pure hydrogen gas
target. The average invariant mass of the photon-proton system has a value of
= 4.9 GeV, while the average negative squared four-momentum of the virtual
photon is = 1.7 GeV^2. The ratio of the present result to the
corresponding spin asymmetry in inclusive deep-inelastic scattering is in
agreement with an early theoretical prediction based on the generalised vector
meson dominance model.Comment: 10 pages, 4 embedded figures, LaTe
Single-spin Azimuthal Asymmetries in Electroproduction of Neutral Pions in Semi-inclusive Deep-inelastic Scattering
A single-spin asymmetry in the azimuthal distribution of neutral pions
relative to the lepton scattering plane has been measured for the first time in
deep-inelastic scattering of positrons off longitudinally polarized protons.
The analysing power in the sin(phi) moment of the cross section is 0.019 +/-
0.007(stat.) +/- 0.003(syst.). This result is compared to single-spin
asymmetries for charged pion production measured in the same kinematic range.
The pi^0 asymmetry is of the same size as the pi^+ asymmetry and shows a
similar dependence on the relevant kinematic variables. The asymmetry is
described by a phenomenological calculation based on a fragmentation function
that represents sensitivity to the transverse polarization of the struck quark.Comment: 4 pages, 1 figure, replaced to correct eprint author field, 2nd
replacement to correct figure; upper limit of model predictions are
corrected. No correction to data or conclusion
Common Peptides Study of Aminoacyl-tRNA Synthetases
Aminoacyl tRNA synthetases (aaRSs) constitute an essential enzyme super-family, providing fidelity of the translation process of mRNA to proteins in living cells. They are common to all kingdoms and are of utmost importance to all organisms. It is thus of great interest to understand the evolutionary relationships among them and underline signature motifs defining their common domains.We utilized the Common Peptides (CPs) framework, based on extracted deterministic motifs from all aaRSs, to study family-specific properties. We identified novel aaRS–class related signatures that may supplement the current classification methods and provide a basis for identifying functional regions specific to each aaRS class. We exploited the space spanned by the CPs in order to identify similarities between aaRS families that are not observed using sequence alignment methods, identifying different inter-aaRS associations across different kingdom of life. We explored the evolutionary history of the aaRS families and evolutionary origins of the mitochondrial aaRSs. Lastly, we showed that prevalent CPs significantly overlap known catalytic and binding sites, suggesting that they have meaningful functional roles, as well as identifying a motif shared between aaRSs and a the Biotin-[acetyl-CoA carboxylase] synthetase (birA) enzyme overlapping binding sites in both families.The study presents the multitude of ways to exploit the CP framework in order to extract meaningful patterns from the aaRS super-family. Specific CPs, discovered in this study, may play important roles in the functionality of these enzymes. We explored the evolutionary patterns in each aaRS family and tracked remote evolutionary links between these families
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