117,026 research outputs found

    Amplitudes and Resonances from an Energy-Dependent Analysis of pbar+p -> pi+pi

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    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

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    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 XHX^H of the building X=X(G)X = X(G) of a connected reductive algebraic group GG, where HH is a subgroup of GG.Comment: 4 pages; minor changes, to appear in C. R. Acad. Sci. Paris Ser. I Mat

    Criteria for beach nourishment: biological guidelines for sabellariid worm reef

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    It has been the purpose of this project to provide the basic biological and geological data together with summary guidelines which will allow the Florida Dept. of Environmental Regulation and project engineers to make the necessary permitting and design decisions for beach nourishment project in worm reef areas. The present work seeks to determine the tolerance of P. lapidosa to sediment burial, the tolerance of these organisms to exposure to hydrogen sulfide, the tolerances of these organisms to heavy silt loads in the water, etc. (37pp.

    Two kinds of procedural semantics for privative modification

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    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

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    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-204, AST-205, and AST-206 blended wing-fuse large supersonic transport configuration concepts

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    The aerodynamic design and analysis of three blended wing-fuselage supersonic cruise configurations providing four, five, and six abreast seating was conducted using a previously designed supersonic cruise configuration as the baseline. The five abreast configuration was optimized for wave drag at a Mach number of 2.7. The four and six abreast configurations were also optimized at Mach 2.7, but with the added constraint that the majority of their structure be common with the five abreast configuration. Analysis of the three configurations indicated an improvement of 6.0, 7.5, and 7.7 percent in cruise lift-to-drag ratio over the baseline configuration for the four, five, and six abreast configurations, respectively

    Aerodynamic design and analysis of the AST-200 supersonic transport configuration concept

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    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

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    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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