661 research outputs found
A non local unitary vector model in 3-D
We present a unified analysis of single excitation vector models in 3D. We
show that there is a family of first order master actions related by duality
transformations which interpolate between the different models. We use a
Hamiltonian (2+1) analysis to show the equivalence of the self-dual and
topologically massive models with a covariant non local model which propagates
also a single massive excitation. It is shown how the non local terms appears
naturally in the path integral framework.Comment: 13 pages, 1 figur
Two glycosylation sites on the N-terminal segment of porcine pars distalis pro-opiomelanocortin
Purification of three rat atrial natriuretic factors and their amino acid composition
AbstractA natriuretic factor has been described in the specific granules of rat atria. We have purified three factors which seem to be low-Mr peptides. They have been purified by means of acid extraction, octadecyl Sep-Pak cartridges, and chromatography on Bio-Gel P-10, CM Bio-Gel A, Mono S and reverse-phase high-performance liquid chromatography columns. The factors contain 26, 31 and 33 amino acids and may have been partially degraded during isolation. They are all 3 biologically active and the shorter one is the most active with a specific activity of 450000 units/mg
Primary structure of a high Mr form of rat atrial natriuretic factor
AbstractDuring the purification of rat atrial natriuretic factor (ANF), low, intermediate and high Mr forms were observed. In this report we describe the purification and amino acid sequence of a 73 residue peptide containing at its C-terminus the previously sequenced 33 amino acid ANF peptide. The cleabage necessary to produce the 33 amino acid ANF from the 73 amino acid precursor occurs at a Leuî—¸Leu bond. We also report the amino acid composition of an even longer form of ANF containing about 103 residues, in which the extension is amino terminal to the 73 peptide. A computer data bank search showed that the determined sequence is a novel one and is not homologous to any known proteins or segment thereof. The natriuretic activity of the 73 amino acid form when compared to that of a synthetic ANF peptide, comprising the sequence of the last 26 amino acids of ANF, was found to be slightly lower
Impact of electrolyzed water applied as an alternative treatment in vineyard on grape and wine quality.
CAT: Robust attitude control of a telescope with flexible modes
The requirements concerning satellite optical instruments pointing stability are getting more and more stringent. To put up with a disturbed dynamic environment, the Line-of-Sight (LOS) control laws have to be efficient over a large bandwidth. One of the main performance limitation comes from the flexible modes of these optical payloads and their variations w.r.t host satellite configuration. To solve this problem, both classical frequency domain and modern H2/H1 syntheses have been performed and validated on the CAT experimental test facility (CAT: Contrôle d’Attitude
de TĂ©lescope)
Two-mirror Schwarzschild aplanats. Basic relations
It is shown that the theory of aplanatic two-mirror telescopes developed by
Karl Schwarzschild in 1905 leads to the unified description both the prefocal
and the postfocal systems. The class of surfaces in the ZEMAX optical program
has been properly extended to ascertain the image quality in exact
Schwarzschild aplanats. A comparison of Schwarzschild aplanats with approximate
Ritchey-Chretien and Gregory-Maksutov aplanatic telescopes reveals a noticeable
advantage of the former at fast focal ratio of the system.Comment: 19 page
Continuous non-perturbative regularization of QED
We regularize in a continuous manner the path integral of QED by construction
of a non-local version of its action by means of a regularized form of Dirac's
functions. Since the action and the measure are both invariant under
the gauge group, this regularization scheme is intrinsically non-perturbative.
Despite the fact that the non-local action converges formally to the local one
as the cutoff goes to infinity, the regularized theory keeps trace of the
non-locality through the appearance of a quadratic divergence in the transverse
part of the polarization operator. This term which is uniquely defined by the
choice of the cutoff functions can be removed by a redefinition of the
regularized action. We notice that as for chiral fermions on the lattice, there
is an obstruction to construct a continuous and non ambiguous regularization in
four dimensions. With the help of the regularized equations of motion, we
calculate the one particle irreducible functions which are known to be
divergent by naive power counting at the one loop order.Comment: 23 pages, LaTeX, 5 Encapsulated Postscript figures. Improved and
revised version, to appear in Phys. Rev.
Time-resolved diffuse optical tomography for non-invasive flap viability assessment: Pre-clinical tests on rats
We present a new setup for time-resolved diffuse optical tomography based on multiple source-detector acquisitions analysed by means of the Mellin-Laplace transform. The proposed setup has been used to perform pre-clinical measurements on rats in order to show its suitability for non-invasive assessment of flap viability
Pooled analysis of higher versus lower blood pressure targets for vasopressor therapy septic and vasodilatory shock
PURPOSE: Guidelines for shock recommend mean arterial pressure (MAP) targets for vasopressor therapy of at least 65Â mmHg and, until recently, suggested that patients with underlying chronic hypertension and atherosclerosis may benefit from higher targets. We conducted an individual patient-data meta-analysis of recent trials to determine if patient variables modify the effect of different MAP targets.
METHODS: We searched the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials for randomized controlled trials of higher versus lower blood pressure targets for vasopressor therapy in adult patients in shock (until November 2017). After obtaining individual patient data from both eligible trials, we used a modified version of the Cochrane Collaboration\u27s instrument to assess the risk of bias of included trials. The primary outcome was 28-day mortality.
RESULTS: Included trials enrolled 894 patients. Controlling for trial and site, the OR for 28-day mortality for the higher versus lower MAP targets was 1.15 (95% CI 0.87-1.52). Treatment effect varied by duration of vasopressors before randomization (interaction p = 0.017), but not by chronic hypertension, congestive heart failure or age. Risk of death increased in higher MAP groups among patients on vasopressors > 6 h before randomization (OR 3.00, 95% CI 1.33-6.74).
CONCLUSIONS: Targeting higher blood pressure targets may increase mortality in patients who have been treated with vasopressors for more than 6Â h. Lower blood pressure targets were not associated with patient-important adverse events in any subgroup, including chronically hypertensive patients
- …