605 research outputs found
The effect of aging and cardiorespiratory fitness on the lung diffusing capacity response to exercise in healthy humans
Aging is associated with deterioration in the structure and function of the pulmonary circulation. We characterized the lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (Dm(CO)), and pulmonary-capillary blood volume (V(C)) response to discontinuous incremental exercise at 25, 50, 75, and 90% of peak work (Wpeak) in four groups: 1) Young [27 ± 3 y, maximal oxygen consumption (VÌOâmax) 110 ± 18% age-predicted]; 2) Young Highly-Fit (27 ± 3 y, VÌOâmax 147 ± 8% age-predicted); 3) Old (69 ± 5 y, VÌOâmax 116 ± 13% age-predicted); and 4) Old Highly-Fit (65 ± 5 y, VÌOâmax 162 ± 18% age-predicted). At rest and at 90% Wpeak, DLCO, Dm(CO), and VC were decreased with age. At 90% Wpeak, DLCO, Dm(CO) and VC were greater in Old Highly-Fit vs. Old adults. The slope of the DLCO-cardiac output (QÌ) relationship from rest to end-exercise at 90% Wpeak was not different between Young, Young Highly-Fit, Old and Old Highly-Fit (1.35 vs. 1.44 vs. 1.10 vs. 1.35 mlCO·mmHgâ»Âč·Lbloodâ»Âč, P = 0.388), with no evidence of a plateau in this relationship during exercise; this was also true for Dm(CO)-QÌ and V(C)-QÌ. VÌO2max was positively correlated with: 1) DLCO, Dm(CO), and V(C) at rest; 2) the rest to end-exercise change in DLCO, Dm(CO), and V(C). In conclusion, these data suggest that despite the age-associated deterioration in the structure and function of the pulmonary circulation, expansion of the pulmonary capillary network does not become limited during exercise in healthy individuals regardless of age or cardiorespiratory fitness level
Many-body perturbation calculation of spherical nuclei with a separable monopole interaction: I. Finite nuclei
We present calculations of ground state properties of spherical, doubly
closed-shell nuclei from O to Pb employing the techniques of
many-body perturbation theory using a separable density dependent monopole
interaction. The model gives results in Hartree-Fock order which are of similar
quality to other effective density-dependent interactions. In addition, second
and third order perturbation corrections to the binding energy are calculated
and are found to contribute small, but non-negligible corrections beyond the
mean-field result. The perturbation series converges quickly, suggesting that
this method may be used to calculate fully correlated wavefunctions with only
second or third order perturbation theory. We discuss the quality of the
results and suggest possible methods of improvement.Comment: 20 Pages, 11 figure
Torsion pairs and simple-minded systems in triangulated categories
Let T be a Hom-finite triangulated Krull-Schmidt category over a field k.
Inspired by a definition of Koenig and Liu, we say that a family S of pairwise
orthogonal objects in T with trivial endomorphism rings is a simple-minded
system if its closure under extensions is all of T. We construct torsion pairs
in T associated to any subset X of a simple-minded system S, and use these to
define left and right mutations of S relative to X. When T has a Serre functor
\nu, and S and X are invariant under \nu[1], we show that these mutations are
again simple-minded systems. We are particularly interested in the case where T
is the stable module category of a self-injective algebra \Lambda. In this
case, our mutation procedure parallels that introduced by Koenig and Yang for
simple-minded collections in the derived category of \Lambda. It follows that
the mutation of the set of simple \Lambda-modules relative to X yields the
images of the simple \Gamma-modules under a stable equivalence between \Gamma\
and \Lambda, where \Gamma\ is the tilting mutation of \Lambda\ relative to X.Comment: Minor corrections. To appear in Applied Categorical Structures. The
final publication is available at springerlink.com:
http://link.springer.com/article/10.1007%2Fs10485-014-9365-
Optimal Renormalization Scale and Scheme for Exclusive Processes
We use the BLM method to fix the renormalization scale of the QCD coupling in
exclusive hadronic amplitudes such as the pion form factor and the
photon-to-pion transition form factor at large momentum transfer.
Renormalization-scheme-independent commensurate scale relations are established
which connect the hard scattering subprocess amplitudes that control exclusive
processes to other QCD observables such as the heavy quark potential and the
electron-positron annihilation cross section. The commensurate scale relation
connecting the heavy quark potential, as determined from lattice gauge theory,
to the photon-to-pion transition form factor is in excellent agreement with
data assuming that the pion distribution amplitude is
close to its asymptotic form . We also reproduce the
scaling and normalization of the data at large
momentum transfer. Because the renormalization scale is small, we argue that
the effective coupling is nearly constant, thus accounting for the nominal
scaling behavior of the data. However, the normalization of the space-like pion
form factor obtained from electroproduction experiments is
somewhat higher than that predicted by the corresponding commensurate scale
relation. This discrepancy may be due to systematic errors introduced by the
extrapolation of the electroproduction data to the
pion pole.Comment: 22 pages, Latex, 7 Latex figures. Several references added,
discussion of scale fixing revised for clarity. Final version to appear in
Phys. Rev.
EC85-219 1985 Nebraska Swine Report
This 1985 Nebraska Swine Report was prepared by the staff in Animal Science and cooperating departments for use in the Extension and Teaching programs at the University of Nebraska-Lincoln. Authors from the following areas contributed to this publication: Swine Nutrition, swine diseases, pathology, economics, engineering, swine breeding, meats, agronomy, and diagnostic laboratory. It covers the following areas: breeding, disease control, feeding, nutrition, economics, housing and meats
Polymorphisms in the ICAM1 gene predict circulating soluble intercellular adhesion molecule-1(sICAM-1)
Polymorphisms within the ICAM1 structural gene have been shown to influence circulating levels of soluble intercellular adhesion molecule -1 (sICAM-1) but their relation to atherosclerosis has not been clearly established. We sought to determine whether ICAM1 SNPs are associated with circulating sICAM-1 concentration, coronary artery calcium (CAC), and common and internal carotid intima medial thickness (IMT)
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