731 research outputs found
Richard S. Vasey in a Senior Organ Recital of Original Compositions
This is the program for the senior organ recital of Richard S. Vasey, who performed original compositions. The performance was held on December 13, 1973, in Mitchell Hall. Sue Arnn assisted him, and he was accompanied by the Ouachita University Symphonic Band, which was directed by Marvin A. Lawson
Fermions, Gauge Theories, and the Sinc Function Representation for Feynman Diagrams
We extend our new approach for numeric evaluation of Feynman diagrams to
integrals that include fermionic and vector propagators. In this initial
discussion we begin by deriving the Sinc function representation for the
propagators of spin-1/2 and spin-1 fields and exploring their properties. We
show that the attributes of the spin-0 propagator which allowed us to derive
the Sinc function representation for scalar field Feynman integrals are shared
by fields with non-zero spin. We then investigate the application of the Sinc
function representation to simple QED diagrams, including first order
corrections to the propagators and the vertex.Comment: 10 pages, Latex, 9 figure
Multicentre analysis of incidental findings on low-resolution CT attenuation correction images : an extended study
Objective: To review new incidental findings detected
on low-resolution CT attenuation correction (CTAC)
images acquired during single-photon emission CT-CT
myocardial perfusion imaging as an extension to our
initial study.
Methods: CTAC images acquired as part of myocardial
perfusion imaging performed using single-photon emission
CT at four UK nuclear medicine centres were evaluated as
part of a multicentre study. New incidental findings that
were considered to be clinically significant were evaluated
further. Positive-predictive value (PPV) was determined at
the time of definitive diagnosis.
Results: Out of 3485 patients, 962 (28%) patients had
a positive finding on the CTAC image, of which 824 (24%)
were new findings. 84 (2.4%) patients had findings
that were considered clinically significant at the time of
the CTAC report and which had not been previously
diagnosed. However, only 10 (0.29%) of these had
findings that were confirmed as clinically significant, with
the potential to be detrimental to patient outcome, after
follow-up and definitive diagnosis.
Conclusion: The overall PPV from all centres over the
2-year period was 12%. Each centre achieved what we
considered to be low PPVs with no significant difference
between the present and initial studies. The additional
data from the combined studies show that, statistically,
there is no significant difference between the PPVs from
any of the centres. We conclude that routine reporting of
CTAC images is not beneficial.
Advances in knowledge: This study combined with the
previous study offers a unique evaluation of new clinically
significant incidental findings on low-resolution CT images
in an attempt to determine the benefit of reporting the
CTAC images
A Binary Millisecond Pulsar in Globular Cluster NGC6544
We report the detection of a new 3.06 ms binary pulsar in the globular
cluster NGC6544 using a Fourier-domain ``acceleration'' search. With an implied
companion mass of ~0.01 solar masses and an orbital period of only P_b~1.7
hours, it displays very similar orbital properties to many pulsars which are
eclipsed by their companion winds. The orbital period is the second shortest of
known binary pulsars after 47 Tuc R. The measured flux density of 1.3 +/- 0.4
mJy at 1332 MHz indicates that the pulsar is almost certainly the known
steep-spectrum point source near the core of NGC6544.Comment: Accepted by ApJ Letters on 11 October 2000, 5 page
Fast Evaluation of Feynman Diagrams
We develop a new representation for the integrals associated with Feynman
diagrams. This leads directly to a novel method for the numerical evaluation of
these integrals, which avoids the use of Monte Carlo techniques. Our approach
is based on based on the theory of generalized sinc () functions,
from which we derive an approximation to the propagator that is expressed as an
infinite sum. When the propagators in the Feynman integrals are replaced with
the approximate form all integrals over internal momenta and vertices are
converted into Gaussians, which can be evaluated analytically. Performing the
Gaussians yields a multi-dimensional infinite sum which approximates the
corresponding Feynman integral. The difference between the exact result and
this approximation is set by an adjustable parameter, and can be made
arbitrarily small. We discuss the extraction of regularization independent
quantities and demonstrate, both in theory and practice, that these sums can be
evaluated quickly, even for third or fourth order diagrams. Lastly, we survey
strategies for numerically evaluating the multi-dimensional sums. We illustrate
the method with specific examples, including the the second order sunset
diagram from quartic scalar field theory, and several higher-order diagrams. In
this initial paper we focus upon scalar field theories in Euclidean spacetime,
but expect that this approach can be generalized to fields with spin.Comment: uses feynmp macros; v2 contains improved description of
renormalization, plus other minor change
Law professors want hearing, vote on Garland
Dear Senator Fischer and Senator Sasse,
We write this as citizens, but we all teach at the University of Nebraska College of Law. We hold different political viewpoints and disagree frequentIy with each other on political and legal issues. As law professors, however, we share a deep commitment to the rule of law and an impartial judiciary. We therefore urge you to hold confirmation hearings and a vote on President Obama\u27s Supreme Court nominee, Chief Judge Merrick B. Garland
The nutritional ecology of larvae of Alsophila pometaria and Anisota senatoria feeding on early- and late-season oak foliage
The larvae of Alsophila pometaria (Harr.), feeding on the young foliage of oak, has a higher relative growth rate (RGR) and relative nitrogen accumulation rate (RNAR) than the larvae of Anisota senatoria (J. E. Smith), feeding on the mature foliage of oak. Although the young oak foliage is more efficiently digested by A. pometaria (higher AD's), it is not more efficiently assimilated and used for growth (no difference in ECI's). Thus, the higher growth rate of A. pometaria is due entirely to a higher consumption rate (RCR and RNCR). Young foliage is significantly higher in nitrogen and water than mature foliage, but phenol and tannin levels are comparable in young and old foliage. A. pometaria consumes the foliage of different oak species at the same rate, independent of nitrogen content, while A. senatoria increases its consumption rate in response to decreased nitrogen levels. As a result, the growth rate of A. pometaria is directly related to leaf nitrogen content, while the growth rate of A. senatoria is independent of leaf nitrogen. The two species of insects have digestive systems that are very similar biochemically, and that are well-designed for effective protein digestion. Tannins and phenols do not influence the nutrional indices of either species. We suggest that the major benefit of spring feeding is the availability of succulent, high-nitrogen foliage, and not the avoidance of high-tannin foliage. The spring feeder appears to have a feeding strategy that favors rapid growth at the expense of efficiency, while the late summer feeder has a strategy that favors efficiency over rate. Alimentées sur feuillage jeune de chêne, les chenilles d' Alsophila pometaria avaient un taux relatif de croissance (RGR) et un taux relatif d'accumulation d'azote (RNAR) plus élevés que les chenilles d' Anisota senatoria alimentées sur feuillage mûr de chêne. Bien que le jeune feuillage soit plus efficacement digéré par A. pometaria (AD plus élevé), il n'est pas assimilé et utilisé pour la croissance avec de meilleurs rendements (les ECI ne sont pas différents). Ainsi le taux de croissance plus élevé d' A. pometaria est dû entièrement à un taux de consommation plus important (RCR et RNCR). Le feuillage jeune est significativement plus riche en azote et en eau que le feuillage mûr, mais les niveaux de phénol et de tanins sont les mêmes. A pometaria consomme les feuilles de différentes espèces de chênes au même taux, indépendamment de la teneur en azote, tandis que A. senatoria accroît sa consommation en réponse à une diminution de la teneur en azote. Il en résulte que le taux de croissance d' A. pometaria dépend directement de la teneur en azote des feuilles, tandis que celui d' A. senatoria en est indépendant. Les systèmes digestifs des deux insectes sont biochimiquement semblables et sont efficaces pour la digestion des protéines. Les tanins et les phénols n'influent pas sur les indices nutritionnels de ces deux espèces. Nous estimons que le principal intérêt de l'alimentation printanière est la disponibilité en feuillage succulent, riche en azote, et non l'absence de feuilles à haute teneur en tanin. L'alimentation printanière semble correspondre à une strategie alimentaire qui favorise la croissance aux dépens de l'efficacité tandis que l'alimentation en fin d'été est une stratégie qui favorise l'efficacité sur la rapidité.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42708/1/10667_2004_Article_BF00217527.pd
Influence of real-world characteristics on outcomes for patients with methicillin-resistant Staphylococcal skin and soft tissue infections:a multi-country medical chart review in Europe
BACKGROUND: Patient-related (demographic/disease) and treatment-related (drug/clinician/hospital) characteristics were evaluated as potential predictors of healthcare resource use and opportunities for early switch (ES) from intravenous (IV)-to-oral methicillin-resistant Staphylococcus aureus (MRSA)-active antibiotic therapy and early hospital discharge (ED). METHODS: This retrospective observational medical chart study analyzed patients (across 12 European countries) with microbiologically confirmed MRSA complicated skin and soft tissue infections (cSSTI), ≥3 days of IV anti-MRSA antibiotics during hospitalization (July 1, 2010-June 30, 2011), and discharged alive by July 31, 2011. Logistic/linear regression models evaluated characteristics potentially associated with actual resource use (length of IV therapy, length of hospital stay [LOS], IV-to-oral antibiotic switch), and ES and ED (using literature-based and expert-verified criteria) outcomes. RESULTS: 1542 patients (mean ± SD age 60.8 ± 16.5 years; 61.5% males) were assessed with 81.0% hospitalized for MRSA cSSTI as the primary reason. Several patient demographic, infection, complication, treatment, and hospital characteristics were predictive of length of IV therapy, LOS, IV-to-oral antibiotic switch, or ES and ED opportunities. Outcomes and ES and ED opportunities varied across countries. Length of IV therapy and LOS (r = 0.66, p < 0.0001) and eligibilities for ES and ED (r = 0.44, p < 0.0001) showed relatively strong correlations. IV-to-oral antibiotic switch patients had significantly shorter length of IV therapy (−5.19 days, p < 0.001) and non-significantly shorter LOS (−1.86 days, p > 0.05). Certain patient and treatment characteristics were associated with increased odds of ES (healthcare-associated/ hospital-acquired infection) and ED (patient living arrangements, healthcare-associated/ hospital-acquired infection, initiating MRSA-active treatment 1–2 days post cSSTI index date, existing ED protocol), while other factors decreased the odds of ES (no documented MRSA culture, ≥4 days from admission to cSSTI index date, IV-to-oral switch, IV line infection) and ED (dementia, no documented MRSA culture, initiating MRSA-active treatment ≥3 days post cSSTI index date, existing ES protocol). CONCLUSIONS: Practice patterns and opportunity for further ES and ED were affected by several infection, treatment, hospital, and geographical characteristics, which should be considered in identifying ES and ED opportunities and designing interventions for MRSA cSSTI to reduce IV days and LOS while maintaining the quality of care. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2334-14-476) contains supplementary material, which is available to authorized users
KO-Homology and Type I String Theory
We study the classification of D-branes and Ramond-Ramond fields in Type I
string theory by developing a geometric description of KO-homology. We define
an analytic version of KO-homology using KK-theory of real C*-algebras, and
construct explicitly the isomorphism between geometric and analytic
KO-homology. The construction involves recasting the Cl(n)-index theorem and a
certain geometric invariant into a homological framework which is used, along
with a definition of the real Chern character in KO-homology, to derive
cohomological index formulas. We show that this invariant also naturally
assigns torsion charges to non-BPS states in Type I string theory, in the
construction of classes of D-branes in terms of topological KO-cycles. The
formalism naturally captures the coupling of Ramond-Ramond fields to background
D-branes which cancel global anomalies in the string theory path integral. We
show that this is related to a physical interpretation of bivariant KK-theory
in terms of decay processes on spacetime-filling branes. We also provide a
construction of the holonomies of Ramond-Ramond fields in Type II string theory
in terms of topological K-chains.Comment: 40 pages; v4: Clarifying comments added, more detailed proof of main
isomorphism theorem given; Final version to be published in Reviews in
Mathematical Physic
Studies of Vibrational Properties in Ga Stabilized d-Pu by Extended X-ray Absorption Fine Structure
Temperature dependent extended x-ray absorption fine structure (EXAFS)
spectra were measured for a 3.3 at% Ga stabilized Pu alloy over the range T= 20
- 300 K at both the Ga K-edge and the Pu L_III-edge. The temperature dependence
of the pair-distance distribution widths, \sigma(T) was accurately modeled
using a correlated-Debye model for the lattice vibrational properties,
suggesting Debye-like behavior in this material. We obtain pair- specific
correlated-Debye temperatures, \Theta_cD, of 110.7 +/- 1.7 K and 202.6 +/- 3.7
K, for the Pu-Pu and Ga-Pu pairs, respectively. These results represent the
first unambiguous determination of Ga-specific vibrational properties in PuGa
alloys, and indicate the Ga-Pu bonds are significantly stronger than the Pu-Pu
bonds. This effect has important implications for lattice stabilization
mechanisms in these alloys.Comment: 7 pages, 4 figures, Phys. Rev. B in pres
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