9,793 research outputs found
Four-loop results on anomalous dimensions and splitting functions in QCD
We report on recent progress on the flavour non-singlet splitting functions
in perturbative QCD. The~exact four-loop (N^3LO) contribution to these
functions has been obtained in the planar limit of a large number of colours.
Phenomenologically sufficient approximate expressions have been obtained for
the parts not exactly known so far. Both cases include results for the
four-loop cusp and virtual anomalous dimensions which are relevant well beyond
the evolution of non-singlet quark distributions, for which an accuracy of
(well) below 1% has now been been reached.Comment: 11 pages, LaTeX (PoS style), 4 eps-figures. Contribution to the
proceedings of `RADCOR 2017', St. Gilgen (Austria), September 201
First Forcer results on deep-inelastic scattering and related quantities
We present results on the fourth-order splitting functions and coefficient
functions obtained using Forcer, a four-loop generalization of the Mincer
program for the parametric reduction of self-energy integrals. We have computed
the respective lowest three even-N and odd-N moments for the non-singlet
splitting functions and the non-singlet coefficient functions in
electromagnetic and nu+nu(bar) charged-current deep-inelastic scattering, and
the N=2 and N=4 results for the corresponding flavour-singlet quantities.
Enough moments have been obtained for an LLL-based determination of the
analytic N-dependence of the nf^3 and nf^2 parts, respectively, of the singlet
and non-singlet splitting functions. The large-N limit of the latter provides
the complete nf^2 contributions to the four-loop cusp anomalous dimension. Our
results also provide additional evidence of a non-vanishing contribution of
quartic group invariants to the cusp anomalous dimension.Comment: 11 pages, LaTeX (PoS style), 4 eps-figures. To appear in the
proceedings of `Loops & Legs 2016', Leipzig (Germany), April 201
Pathophysiologie des Kapnoperitoneums: Implikationen für Beatmung und Hämodynamik
Zusammenfassung: Die laparoskopische Chirurgie wurde Anfang der 50er Jahre für gynäkologische Eingriffe eingeführt. Mit verbesserter Technik erweiterte sich das Spektrum in den letzten Jahrzehnten beträchtlich. Es wurden zunehmend komplexere und länger dauernde Operationen durchgeführt. Als Vorteile gegenüber offener Chirurgie wurden eine Reduktion der postoperativen Schmerzen, bessere kosmetische Ergebnisse, raschere Erholung und die Verkürzung der Krankenhausverweildauer angeführt. Infolgedessen wird die Laparoskopie mittlerweile auch bei immer älteren Patienten mit entsprechenden pulmonalen sowie kardiovaskulären Komorbiditäten und in der Chirurgie für adipöse Patienten eingesetzt. Eine sichere Anästhesieführung setzt detaillierte Kenntnisse der Pathophysiologie des Kapnoperitoneums voraus, insbesondere im Hinblick auf dessen respiratorische und hämodynamische Konsequenzen. Der Übersichtsartikel diskutiert die wichtigsten Effekte des Kapnoperitoneums und stellt aktuelle Forschungsergebnisse sowie deren Umsetzungsmöglichkeiten in der klinischen Praxis da
Anomalous dimensions and splitting functions beyond the next-to-next-to-leading order
We report on recent progress on the splitting functions for the evolution of
parton distributions and related quantities, the (lightlike) cusp anomalous
dimensions, in perturbative QCD. New results are presented for the four-loop
(next-to-next-to-next-to-leading order, N^3LO) contributions to the
flavour-singlet splitting functions and the gluon cusp anomalous dimension. We
present first results, the moments N=2 and N=3, for the five-loop (N^4LO)
non-singlet splitting functions.Comment: 10 pages, LaTeX (PoS style), 3 eps-figures. Contribution to the
proceedings of `Loops & Legs 2018', St. Goar (Germany), April/May 201
The effect of bedrest on various parameters of physiological function. part viii- the . . . effect on the cardiovascular tolerance to passive tilt
Effect of short and long term bed rest on cardiovascular tolerance to passive til
The effect of bedrest on various parameters of physiological function. part xi- the effect of bedrest on blood volume, urinary volume, and urinary electrolyte excretion
Effect of bed rest on blood volume, urinary volume, and urinary electrolyte excretio
The effect of bedrest on various parameters of physiological function. Part XIII - A review of possible mechanisms of orthostatic intolerance to passive tilt
Possible mechanisms of orthostatic intolerance to passive tilt - bed rest and water immersion effects on various parameters of physiological functio
The effect of bedrest on various parameters of physiological function. Part X - The effect of bedrest on the circulatory response to a valsalva maneuver
Quantitative arterial blood pressure change during Valsalva maneuver after bed res
The effect of bedrest on various parameters of physiological function. part vii- cardiac and ventilatory response to the bicycle ergometer test
Cardiac and ventilatory response to bicycle ergometer tes
The effect of bedrest on various parameters of physiological function. part vi- the effect of the performance of periodic flack maneuvers on preventing cardiovascular deconditioning of bedrest
Preventing cardiovascular deconditioning of bedrest by periodic Flack maneuvers - physiological performance and efficienc
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