163 resultados para RESONANCE PRODUCTION


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Streptococcus pyogenes isolates from a tropical region and a subtropical region of Australia with high and low incidences of severe streptococcal diseases, respectively, were analyzed for speA, speB, and speC gene distributions and NAD-glycohydrolase expression. No direct correlation of these characteristics with a propensity to cause invasive diseases was observed.

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Effects of soil water availability on seedling growth, dry matter production and allocation were determined for Gympie ( humid coastal) and Hungry Hills ( dry inland) provenances of Eucalyptus cloeziana F. Muell. and for E. argophloia Blakely ( dry inland) species. Seven-month-old seedlings were subjected to well-watered (100% field capacity, FC), moderate (70% FC) and severe (50% FC) soil water regimes in a glasshouse environment for 14 wk. There were significant differences in seedling growth, biomass production and allocation patterns between species. E. argophloia produced twice as much biomass at 100% FC, and more than three times as much at 70% and 50% FC than did either E. cloeziana provenance. Although the humid provenance of E. cloeziana had a greater leaf area at 100% FC conditions than did the dry provenance, total biomass production did not differ significantly. Both E. cloeziana provenances were highly sensitive to water deficits. E. argophloia allocated 10% more biomass to roots than did E. cloeziana. Allometric analyses indicated that relative biomass allocation patterns were significantly affected by genotype but not by soil water availability. These results have implications for taxon selection for cultivation in humid and subhumid regions.

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The present case report describes the presence of a persistent dysarthria and dysphagia as a consequence of surgical intervention for a choroid plexus papilloma (CPP). WM was a nine year ten month old male who at the time of the present study was seven years post-surgery. A comprehensive perceptual and instrumental test battery was used to document the nature of the dysarthria incorporating all components of speech production including respiration, phonation, resonance, articulation, and prosody. The nature of the dysphagia was evaluated through the use of videofluoroscopic evaluation of swallowing (VFS). Assessments confirmed the presence of a LMN dysarthria, marked by deficits in phonation, respiration, and prosody. Dysphagia assessment revealed deficits in oral preparatory, oral and pharyngeal stages of the swallow. The presence of persistent dysarthria and dysphagia in this case has a number of important implications for the management of children undergoing surgery for fourth ventricle CPPs, in particular the need for appropriate treatment, as well as counselling prior to surgery of the possible negative outcomes related to speech and swallowing. (C) 2003 Elsevier Science Ltd. All rights reserved.

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Bound and resonance states of HO2 have been calculated quantum mechanically by the Lanczos homogeneous filter diagonalization method [Zhang and Smith, Phys. Chem. Chem. Phys. 3, 2282 (2001); J. Chem. Phys. 115, 5751 (2001)] for nonzero total angular momentum J = 1,2,3. For lower bound states, agreement between the results in this paper and previous work is quite satisfactory; while for high lying bound states and resonances these are the first reported results. A helicity quantum number V assignment (within the helicity conserving approximation) is performed and the results indicate that for lower bound states it is possible to assign the V quantum numbers unambiguously, but for resonances it is impossible to assign the V helicity quantum numbers due to strong mixing. In fact, for the high-lying bound states, the mixing has already appeared. These results indicate that the helicity conserving approximation is not good for the resonance state calculations and exact quantum calculations are needed to accurately describe the reaction dynamics for HO2 system. Analysis of the resonance widths shows that most of the resonances are overlapping and the interferences between them lead to large fluctuations from one resonance to another. In accord with the conclusions from earlier J = 0 calculations, this indicates that the dissociation of HO2 is essentially irregular. (C) 2003 American Institute of Physics.

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This article focuses on how US professional sports utilize the New International Division of Cultural Labor to supplement an overly costly local labor pool and over-supplied local market. We argue that while the classic problem of over-production is slowly eroding the sealed-off nature of US culture, the forces of its hyper-protectionist capitalism continue to characterize sports, precluding equal exchange.

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This paper continues the development of a new approach for the design of shim and gradient coils, used in magnetic resonance imaging (MRI) applications. A cylindrical primary coil of radius a and length 2L is placed inside a co-axial shield cylinder of radius b. An active shielding strategy is used to create a desired target field at an arbitrarily specified (cylindrical) location within the primary coil, and to annul the field at a certain radius outside the shield. The form of the interior target field may be chosen arbitrarily by the designer, although zonal and tesseral harmonics are typically used in MRI applications. The method presented here designs coil windings on both the primary and shielding cylinders, to produce fields that conform to the specified interior target field and the annulled field exterior to the shield. An additional feature of the method presented here is that the target field inside the primary coil is matched at two different radii, to improve overall accuracy. The method is illustrated by designing several shielded shim coils, for creating higher order tesseral fields located asymmetrically within the coil. The simpler case of pure zonal fields is discussed separately and applied to the design of some higher order shielded coils.

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Raw milk samples from two different sources were stored at 2degreesC, 4degreesC and 7degreesC for 10 days and the growth of psychrotrophic bacteria, production of proteinase and proteolysis in the milks were measured during storage. Peptide analyses by the fluorescamine method and RP-HPLC were used in determination of proteolysis and proteinase activity. The average times taken for the psychrotroph counts to reach 10(7) cfu/mL at 2degreesC, 4degreesC and 7degreesC were approximately 9, 7 and 4 days, although there was considerable variation in growth rates in the different milks. There was little correlation between psychrotroph counts and either proteolysis or proteinase activity levels. At 2degreesC, no milk stored showed significant proteolysis by the fluorescamine method after 10 days' storage, but significant proteinase activity could be measured in some of these milks at 8 and 10 days. RP-HPLC analysis was a more sensitive means of detecting peptides than the fluorescamine method.

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We present the quantum theory of the far-off-resonance continuous-wave Raman laser using the Heisenberg-Langevin approach. We show that the simplified quantum Langevin equations for this system are mathematically identical to those of the nondegenerate optical parametric oscillator in the time domain with the following associations: pump pump, Stokes signal, and Raman coherence idler. We derive analytical results for both the steady-state behavior and the time-dependent noise spectra, using standard linearization procedures. In the semiclassical limit, these results match with previous purely semiclassical treatments, which yield excellent agreement with experimental observations. The analytical time-dependent results predict perfect photon statistics conversion from the pump to the Stokes and nonclassical behavior under certain operational conditions.