957 research outputs found
Coadjoint Orbits and Conformal Field Theory
This thesis describes a new approach to conformal field theory. This approach
combines the method of coadjoint orbits with resolutions and chiral vertex
operators to give a construction of the correlation functions of conformal
field theories in terms of geometrically defined objects. Explicit formulae are
given for representations of Virasoro and affine algebras in terms of a local
gauge choice on the line bundle associated with geometric quantization of a
given coadjoint orbit; these formulae define a new set of explicit bosonic
realizations of these algebras. The coadjoint orbit realizations take the form
of dual Verma modules, making it possible to avoid the technical difficulties
associated with the two-sided resolutions which arise from Feigin-Fuchs and
Wakimoto realizations. Formulae are given for screening and intertwining
operators on the coadjoint orbit representations. Chiral vertex operators
between Virasoro modules are constructed, and related directly to Virasoro
algebra generators in certain cases. From the point of view taken in this
thesis, vertex operators have a geometric interpretation as differential
operators taking sections of one line bundle to sections of another. A
suggestion is made that by connecting this description with recent work
deriving field theory actions from coadjoint orbits, a deeper understanding of
the geometry of conformal field theory might be achieved.Comment: 121 pages (Ph.D. thesis) LBL-34507. Run LaTeX *3* times for t.o.c.
(no changes in content -- AMS fonts are replaced by more universal bold fonts
and some lines causing problems with non-standard tex versions are fixed.
Farmville\u27s WFLO (95.7 FM) interviews President Reveley
In June, Longwood President W. Taylor Reveley IV was interviewed by Francis Wood on Farmville\u27s WFLO (95.7 FM and 870 AM) as part of their Call Flo morning radio show.
In the interview, President Reveley talks about his family background, his new role as the president of Longwood University, various challenges in higher education and much more
Dielectric Fundamental Strings in Matrix String Theory
Matrix string theory is equivalent to type IIA superstring theory in the
light-cone gauge, together with extra degrees of freedom representing D-brane
states. It is therefore the appropriate framework in which to study systems of
multiple fundamental strings expanding into higher-dimensional D-branes.
Starting from Matrix theory in a weakly curved background, we construct the
linear couplings of closed string fields to type IIA Matrix strings. As a
check, we show that at weak coupling the resulting action reproduces light-cone
gauge string theory in a weakly curved background. Further dualities give a
type IIB Matrix string theory and a type IIA theory of Matrix strings with
winding. We comment on the dielectric effect in each of these theories, giving
some explicit solutions describing fundamental strings expanding into various
Dp-branes.Comment: Plain LaTeX, 25 pages. Reference added. Version to appear to NP
Three-graviton scattering in Matrix theory revisited
We consider a subset of the terms in the effective potential describing
three-graviton interactions in Matrix theory and in classical
eleven-dimensional supergravity. In agreement with the results of Dine and
Rajaraman, we find that these terms vanish in Matrix theory. We show that the
absence of these terms is compatible with the classical supergravity theory
when the theory is compactified in a lightlike direction, resolving an apparent
discrepancy between the two theories. A brief discussion is given of how this
calculation might be generalized to compare the Matrix theory and supergravity
descriptions of an arbitrary 3-body system.Comment: 9 pages, LaTeX; v2: reference added, v3: text unchanged, Note added
clarifying connection with other recent result
Conformal Invariance of the D-Particle Effective Action
It is shown that the effective theory of D-particles has conformal symmetry
with field-dependent parameters. This is a consequence of the supersymmetry.
The string coupling constant is not transformed in contrast with the recent
proposal of generalized conformal symmtery by Jevicki et al. This conformal
symmetry can also be generalized to other Dp-brane systems.Comment: 12 pages, LaTeX, typos corrected, one footnote and one note adde
Recipes for Determining Doneness in Poultry Do Not Provide Appropriate Information Based on US Government Guidelines
Research has shown that consumers use unsafe food handling practices when preparing poultry, which can increase the risk of foodborne illness such as salmonellosis or campylobacteriosis. Recipes from cookbooks, magazines, and the internet commonly are used as sources for consumers to prepare food in homes and the expectation is that food will be safe when prepared. According to the United States Department of Agriculture (USDA), using a thermometer properly is the only way to accurately check for doneness of poultry. The objective of this study was to assess poultry recipes, including recipes for whole birds and poultry parts, to determine if food safety information concerning thermometer use was included within the recipe. Poultry recipes (n = 474) were collected from 217 cookbooks, 28 magazines, 59 websites, and seven blogs. Approximately 33.5% of the recipes contained a specific temperature for doneness, with 73% of those cooked to ≥165 °F/74 °C, as recommended by USDA. Ninety-four percent of recipes used cooking time and about half of the recipes used visual measurements, such as color or juices running clear, to determine doneness. This study showed that most recipes do not contain appropriate information to assure safe cooking of poultry by consumers. Modifying recipes by adding food safety information, such as thermometer use and proper temperatures, could increase the use of proper food preparation behaviors by consumers
A Comparison of Adaptations via Either a Linear Periodization or an Undulating Periodization Model of Weight Training
BACKGROUND: Resistance training has been proven to have a positive impact on parameters such as muscular strength, hypertrophy and endurance. Periodization is a progressive mode of training that has been shown to illicit greater results than programs that stay consistent throughout. The two prime modes of periodization are linear (LP), which progresses from high volume/low intensity to low volume/high intensity, and undulating (UP) which follows an oscillating volume/intensity design. The purpose of this study was to compare the effects of a 12 week linear program to those from an undulating program on strength and body composition when both programs reflect the entire NSCA repetition continuum. METHODS: 10 resistance trained men were matched according to weight-relative strength and randomly assigned to either a linear (N=4, 21 ± 2.5 yrs, 69.08 ± 0.69in, 1178.13 ± 19.5 lbs, 16.9 ± 5.2 %BF) or undulating (N=6, 20 ± 1.7 yrs, 70.27 ± 2.13 in, 180.17 ± 23.98 lbs, 13.67 ± 2.94 %BF) periodization program. Subjects participated in 3 days per week of supervised total body resistance training with repetitions and intensities reflecting the entire NSCA repetition continuum. At 0, 4, 8 and 12-weeks, subjects were tested on body composition via dual energy x-ray absorptiometry, 1RM strength, muscular endurance, vertical jump and anaerobic capacity. Statistical analyses utilized a two-way ANOVA with repeated measures for all criterion variables (p ≤ 0.05). Data are presented as mean ± SD changes from baseline values. RESULTS: Significant main effects for time (p \u3c 0.05) were observed on bench press (LP: 15.03 ± 8.02 lb; UP: 26.10 ± 5.05 lb), leg press (LP:161.07 ± 14.10 lb ; UP: 164.03 ± 55.20 lb), and Wingate peak power (LP: 148.21 ± 78.05 W; UP: 143.22 ± 137.04 W). However, no significant interactions were observed between groups on any of these parameters. Also, no significant group or time effects for time or differences between groups were observed in the measures of percent body fat, lean muscle mass, or vertical jump. CONCLUSION: Both undulating and linear periodization models of resistance training that reflect the entire repetition continuum can bring forth highly significant changes in strength and peak anaerobic power. However, despite the fact that the undulating method resulted in a 43% greater increase in upper body strength, there is no significant difference in the magnitude of the training adaptations that stem from the two methods over 12 weeks
Why is the Matrix Model Correct?
We consider the compactification of M theory on a light-like circle as a
limit of a compactification on a small spatial circle boosted by a large
amount. Assuming that the compactification on a small spatial circle is weakly
coupled type IIA theory, we derive Susskind's conjecture that M theory
compactified on a light-like circle is given by the finite version of the
Matrix model of Banks, Fischler, Shenker and Susskind. This point of view
provides a uniform derivation of the Matrix model for M theory compactified on
a transverse torus for and clarifies the difficulties for
larger values of .Comment: 9 page
Investigation of accessibility of electronic music resources for the visually impaired
The number of students at Western Michigan University (WMU) who require accommodation for disabilities has been increasing in recent years, and is expected to continue to increase in the future. While the University Libraries tries to be responsive to all types of accommodations, students with visual impairments present a particular challenge for libraries to ensure their electronic resources are accessible. Most visually impaired students utilize “screen readers,” software programs that use a speech synthesizer to “read” the text that is displayed on the screen, to navigate web based resources. In an effort to try to better understand how specific screen readers work with our library electronic resources we employed a visually impaired student who is a sophisticated user of screen readers to test our electronic resources.Using a combination of browsers and operating systems, we used Job Access With Speech (JAWS), the most widely used screen reader, and NonVisual Desktop Access (NVDA), an open source screen reader, to test our website, our discovery layer and selected music databases. Databases tested include Music Periodicals Database (ProQuest), RILM Abstracts of Music Literature (EBSCO), and Grove Music Online. As WMU Libraries uses the ExLibris Primo discovery product, our instance of Primo was also tested for accessibility. The presenters will share the findings of the screen reader testing, including a pre-recorded demonstration of a visually impaired student conducting searches with screen readers, and describe our experiences in investigating accessibility of our electronic resources for visually impaired students. Presenters will also make recommendations for improving electronic resources and library services, in general, to better meet the needs of visually impaired patrons
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