680 research outputs found
Monitoring Depth of Hypnosis: Mid-Latency Auditory Evoked Potentials Derived aepEX in Children Receiving Desflurane-Remifentanil Anesthesia
Étude comparée de la valeur nutritive du maïs et des sorghos dans l'alimentation du poulet de chair en zone tropicale sèche
L'analyse de la valeur nutritive du maïs (Zea mays) comparée à celle du sorgho blanc et du sorgho rouge a été effectuée sur 150 poussins d'un jour de souche ROSS 208. Trois lots de cinquante oiseaux chacun, ont été élevés pendant sept semaines et soumis à trois types d'aliments contenant du maïs jaune (RM), du sorgho blanc (RSB) et du sorgho rouge (RSR). La consommation alimentaire a été de 87g/jour pour le lot RSB et de 84g/jour pour RM et RSR. La différence entre la quantité d'aliments ingérés par les poulets de deux autres lots RM et RSR. À la fin de la septième semaines, les poulets pesaient 2126g pour le lot RSM, 2107g pour le lot RSB et 2079g pour le lot RSR. Cette différence pondérale n'est pas significative entre les trois lots; il en est de même pour les gains moyens quotidiens qui sont identiques dans les 3 lots (46g). Le rendement carcasse a été plus élevé avec l'aliment à base de sorgho rouge (71,4%). Les poulets nourris du maïs (RM) présentaient des carcasses et des pattes jaunes.Comparative study of nutritive value of tropical corn (Zea mays) and sorghum (Sorghum vulgare) in broilerOne hundred and fifty one day-old chicks,ROSS 208 strain have been used to compare nutritive value of corn (Zea mays) and soghum (Sorghum vulgare) for broilers. Chicks were divided into three groups and fed three diets containing yellow corn (RM), white sorghum (RSB) and red Sorghum (RSR) during 7 weeks. Feed intake was higher in group RSB, 87g /day, RM 85g /day for RM and 84g /day for RSR respectively. The difference between intake in the three groups was significant (P< 0,05). But the weights at slaughter were not significantly different. The average daily gains (ADG) was 46g in aIl groups. Carcass yield was significantly influenced by the diets
Radiative Corrections to Fixed Target Moller Scattering Including Hard Bremsstrahlung Effects
We present a calculation of the complete electroweak radiative
corrections to the Moller scattering process e^-e^- -> e^-e^-, including hard
bremsstrahlung contributions. We study the effects of these corrections on both
the total cross section and polarization asymmetry measured in low energy fixed
target experiments. Numerical results are presented for the experimental cuts
relevant for E-158, a fixed target e^-e^- experiment being performed at SLAC;
the effect of hard bremsstrahlung is to shift the measured polarization
asymmetry by approximately +4%. We briefly discuss the remaining theoretical
uncertainty in the prediction for the low energy Moller scattering polarization
asymmetry.Comment: 22 pgs; minor clarifications added and typos fixe
A simple variational approach to the quantum Frenkel-Kontorova model
We present a simple and complete variational approach to the one-dimensional
quantum Frenkel-Kontorova model. Dirac's time-dependent variational principle
is adopted together with a Hatree-type many-body trial wavefunction for the
atoms. The single-particle state is assumed to have the Jackiw-Kerman form. We
obtain an effective classical Hamiltonian for the system which is simple enough
for a complete numerical solution for the static ground state of the model.
Numerical results show that our simple approach captures the essence of the
quantum effects first observed in quantum Monte Carlo studies.Comment: 12 pages, 2 figure
Water uptake by biomass burning aerosol at sub- and supersaturated conditions: closure studies and implications for the role of organics
We investigate the CCN activity of freshly emitted biomass burning particles and their hygroscopic growth at a relative humidity (RH) of 85%. The particles were produced in the Mainz combustion laboratory by controlled burning of various wood types. The water uptake at sub- and supersaturations is parameterized by the hygroscopicity parameter, κ (c.f. Petters and Kreidenweis, 2007). For the wood burns, κ is low, generally around 0.06. The main emphasis of this study is a comparison of κ derived from measurements at sub- and supersaturated conditions (κG and κCCN), in order to see whether the water uptake at 85% RH can predict the CCN properties of the biomass burning particles. Differences in κGand κCCN can arise through solution non-idealities, the presence of slightly soluble or surface active compounds, or non-spherical particle shape. We find that κG and κCCN agree within experimental uncertainties (of around 30%) for particle sizes of 100 and 150 nm; only for 50 nm particles is κCCN larger than κG by a factor of 2. The magnitude of this difference and its dependence on particle size is consistent with the presence of surface active organic compounds. These compounds mainly facilitate the CCN activation of small particles, which form the most concentrated solution droplets at the point of activation. The 50 nm particles, however, are only activated at supersaturations higher than 1% and are therefore of minor importance as CCN in ambient clouds. By comparison with the actual chemical composition of the biomass burning particles, we estimate that the hygroscopicity of the water-soluble organic carbon (WSOC) fraction can be represented by a κWSOC value of approximately 0.2. The effective hygroscopicity of a typical wood burning particle can therefore be represented by a linear mixture of an inorganic component with κ ≅ 0.6, a WSOC component with κ ≅ 0.2, and an insoluble component with κ = 0
A posteriori inclusion of parton density functions in NLO QCD final-state calculations at hadron colliders: The APPLGRID Project
A method to facilitate the consistent inclusion of cross-section measurements
based on complex final-states from HERA, TEVATRON and the LHC in proton parton
density function (PDF) fits has been developed. This can be used to increase
the sensitivity of LHC data to deviations from Standard Model predictions. The
method stores perturbative coefficients of NLO QCD calculations of final-state
observables measured in hadron colliders in look-up tables. This allows the
posteriori inclusion of parton density functions (PDFs), and of the strong
coupling, as well as the a posteriori variation of the renormalisation and
factorisation scales in cross-section calculations.
The main novelties in comparison to original work on the subject are the use
of higher-order interpolation, which substantially improves the trade-off
between accuracy and memory use, and a CPU and computer memory optimised way to
construct and store the look-up table using modern software tools.
It is demonstrated that a sufficient accuracy on the cross-section
calculation can be achieved with reasonably small look-up table size by using
the examples of jet production and electro-weak boson (Z, W) production in
proton-proton collisions at a center-of-mass energy of 14 TeV at the LHC.
The use of this technique in PDF fitting is demonstrated in a PDF-fit to HERA
data and simulated LHC jet cross-sections as well as in a study of the jet
cross-section uncertainties at various centre-of-mass energies
Differential hormone-dependent transcriptional activation and -repression by naturally occurring human glucocorticoid receptor variants
The molecular mechanisms underlying primary glucocorticoid resistance or
hypersensitivity are not well understood. Using transfected COS-1 cells as
a model system, we studied gene regulation by naturally occurring mutants
of the glucocorticoid receptor (GR) with single-point mutations in the
regions encoding the ligand-binding domain or the N-terminal domain
reflecting different phenotypic expression. We analyzed the capacity of
these GR variants to regulate transcription from different promoters,
either by binding directly to positive or negative glucocorticoid-response
elements on the DNA or by interfering with protein-protein interactions.
Decreased dexamethasone (DEX) binding to GR variants carrying mutations in
the ligand-binding domain correlated well with decreased capacity to
activate transcription from the mouse mammary tumor virus (MMTV) promoter.
One variant, D641V, which suboptimally activated MMTV promoter-mediated
transcription, repressed a PRL promoter element containing a negative
glucocorticoid-response element with wild type activity. DEX-induced
repression of transcription from elements of the intercellular adhesion
molecule-1 promoter via nuclear factor-kappaB by the D641V variant was
even more efficient compared with the wild type GR. We observed a general
DEX-responsive AP-1-mediated transcriptional repression of the
collagenase-1 promoter, even when receptor variants did not activate
transcription from the MMTV promoter. Our findings indicate that different
point mutations in the GR can affect separate pathways of gene regulation
in a differential fashion, which can explain the various phenotypes
observed
An epitaxial model for heterogeneous nucleation on potent substrates
© The Minerals, Metals & Materials Society and ASM International 2012In this article, we present an epitaxial model for heterogeneous nucleation on potent substrates. It is proposed that heterogeneous nucleation of the solid phase (S) on a potent substrate (N) occurs by epitaxial growth of a pseudomorphic solid (PS) layer on the substrate surface under a critical undercooling (ΔT ). The PS layer with a coherent PS/N interface mimics the atomic arrangement of the substrate, giving rise to a linear increase of misfit strain energy with layer thickness. At a critical thickness (h ), elastic strain energy reaches a critical level, at which point, misfit dislocations are created to release the elastic strain energy in the PS layer. This converts the strained PS layer to a strainless solid (S), and changes the initial coherent PS/N interface into a semicoherent S/N interface. Beyond this critical thickness, further growth will be strainless, and solidification enters the growth stage. It is shown analytically that the lattice misfit (f) between the solid and the substrate has a strong influence on both h and ΔT ; h decreases; and ΔT increases with increasing lattice misfit. This epitaxial nucleation model will be used to explain qualitatively the generally accepted experimental findings on grain refinement in the literature and to analyze the general approaches to effective grain refinement.EPSRC Centre for Innovative Manufacturing in Liquid Metal Engineerin
The , , and electromagnetic form factors
The rainbow truncation of the quark Dyson-Schwinger equation is combined with
the ladder Bethe-Salpeter equation for the meson amplitudes and the dressed
quark-photon vertex in a self-consistent Poincar\'e-invariant study of the pion
and kaon electromagnetic form factors in impulse approximation. We demonstrate
explicitly that the current is conserved in this approach and that the obtained
results are independent of the momentum partitioning in the Bethe-Salpeter
amplitudes. With model gluon parameters previously fixed by the condensate, the
pion mass and decay constant, and the kaon mass, the charge radii and spacelike
form factors are found to be in good agreement with the experimental data.Comment: 8 pages, 6 figures, Revte
QCD Form Factors and Hadron Helicity Non-Conservation
Recent data for the ratio shocked the
community by disobeying expectations held for 50 years. We examine the status
of perturbative QCD predictions for helicity-flip form factors. Contrary to
common belief, we find there is no rule of hadron helicity conservation for
form factors. Instead the analysis yields an inequality that the leading power
of helicity-flip processes may equal or exceed the power of helicity conserving
processes. Numerical calculations support the rule, and extend the result to
the regime of laboratory momentum transfer . Quark orbital angular
momentum, an important feature of the helicity flip processes, may play a role
in all form factors at large , depending on the quark wave functions.Comment: 25 pages, 5 figure
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