98,743 research outputs found
Amplitudes and Resonances from an Energy-Dependent Analysis of pbar+p -> pi+pi
The amplitudes at a series of discrete energies obtained from a previuos
analysis of pbar+p -> pi+pi have been used as input to a global energy-
dependent analysis of data in the momentum range 360 - 1550 MeV/c. The results
confirm the previous analysis and yield refined values for meson resonance
parameters in this energy region.Comment: 8 pages, LaTex, 2 postscript figures, a reference is correcte
On Tits' Centre Conjecture for Fixed Point Subcomplexes
We give a short and uniform proof of a special case of Tits' Centre
Conjecture using a theorem of J-P. Serre and a result from our earlier work. We
consider fixed point subcomplexes of the building of a
connected reductive algebraic group , where is a subgroup of .Comment: 4 pages; minor changes, to appear in C. R. Acad. Sci. Paris Ser. I
Mat
Two kinds of procedural semantics for privative modification
In this paper we present two kinds of procedural semantics for privative modification. We do this for three reasons. The first reason is to launch a tough test case to gauge the degree of substantial agreement between a constructivist and a realist interpretation of procedural semantics; the second is to extend Martin-L ̈f’s Constructive Type Theory to privative modification, which is characteristic of natural language; the third reason is to sketch a positive characterization of privation
The hypothalamic-pituitary-adrenal axis in critical illness
Plasma ACTH and cortisol concentrations are frequently elevated in patients in intensive care units (ICU). To examine the functional integrity of the hypothalamic-pituitary-adrenal axis during critical illness, we evaluated prospectively 53 ICU patients in a general medical ICU. Thirty-one patients and 7 normal controls underwent an overnight dexamethasone suppression test (3 mg dexamethasone, orally, at 2300 h). Plasma ACTH and serum cortisol were measured at 0900 h. In a separate experiment, 22 patients and 7 control subjects underwent a CRH stimulation test [100 micrograms human (h) CRH, iv]. ACTH and cortisol concentrations were determined from -15 to 120 min. Compared to normal controls, plasma ACTH and serum cortisol concentrations were not fully suppressible by dexamethasone [mean +/- SEM: plasma ACTH, 21 +/- 4 vs. 3 +/- 0.5 pg/mL (4.7 +/- 0.9 vs. 0.7 +/- 0.1 pmol/L); serum cortisol, 13.9 +/- 1.9 vs. 1.5 +/- 0.3 micrograms/dL (390 +/- 50 vs. 40 +/- 10 nmol/L); P = 0.0001], demonstrating an altered glucocorticoid feedback in the ICU patients. Patients undergoing hCRH stimulation had clearly elevated mean baseline plasma ACTH and serum cortisol concentrations [ACTH, 78 +/- 20 pg/mL vs. 15 +/- 3 in controls (17.2 +/- 4.4 vs. 3.4 +/- 0.7 pmol/L; P = 0.007); cortisol, 36.8 +/- 3.4 micrograms/dL vs. 9.6 +/- 1.2 (1020 +/- 80 vs. 260 +/- 30 nmol/L; P = 0.0001)]. Despite elevated baseline glucocorticoid concentrations, stimulation with hCRH resulted in significantly higher peak plasma ACTH concentrations 15 min after hCRH than in controls [134 +/- 31 vs. 48 +/- 9 pg/mL (29.5 +/- 6.8 vs. 10.6 +/- 2.0 pmol/L); P < 0.05]. Serum cortisol concentrations in ICU patients were significantly elevated throughout the test period (P = 0.0001) and rose to a peak of 43.9 +/- 3.5 micrograms/dL compared to 18.2 +/- 2.0 micrograms/dL in controls (1210 +/- 70 vs. 500 +/- 60 nmol/L). We conclude that ICU patients have a markedly altered responsiveness of their pituitary corticotroph to suppression with dexamethasone and stimulation with hCRH. These findings may be explained by altered pituitary glucocorticoid feedback and/or hypersecretion of peptides with CRH-like activity (vasopressin and cytokines) during critical illness
Aerodynamic design and analysis of the AST-200 supersonic transport configuration concept
The design and analysis of a supersonic transport configuration was conducted using linear theory methods in conjunction with appropriate constraints. Wing optimization centered on the determination of the required twist and camber and proper integration of the wing and fuselage. Also included in the design are aerodynamic refinements to the baseline wing thickness distribution and nacelle shape. Analysis to the baseline and revised configurations indicated an improvement in lift-to-drag ratio of 0.36 at the Mach 2.7 cruise condition. Validation of the design is planned through supersonic wing tunnel tests
Anti-Unruh Phenomena
We find that a uniformly accelerated particle detector coupled to the vacuum
can cool down as its acceleration increases, due to relativistic effects. We
show that in (1+1)-dimensions, a detector coupled to the scalar field vacuum
for finite timescales (but long enough to satisfy the KMS condition) has a KMS
temperature that decreases with acceleration, in certain regimes. This
contrasts with the heating that one would expect from the Unruh effect.Comment: 6 pages, 5 figures. RevTex 4.1. V2. Typos in the plots labeling
corrected and plot rescaled. New discussion section added. Title change
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