6,236 research outputs found
The Association of Lung Cancer Mortality with Income and Education in Kentucky Counties
Lung cancer, the primary cause of cancer death in the United States, is particularly problematic in Kentucky, which has the nation’s highest rate of adult smokers. In fact, each Kentucky county exceeds the national rate for per capita lung cancer deaths. This project analyzes the relationships between lung cancer deaths, high school graduation rates, per capita personal income and adult smoking – and whether statistically significant differences exist among the variables between Kentucky’s Appalachian and non-Appalachian counties
Policy Analysis: Is There a Relationship Between Required Physical Education in Lower Grades and Adolescent Obesity Rates? A Kentucky Case Study
Childhood obesity has emerged as a national epidemic − and one with serious short- and long-term personal health, medical system and economic consequences. The prevalence of obesity more than doubled among U.S. children ages 6 to 11 between 1980 and 2006, while the rate for those from ages 12 to 19 more than tripled. This study analyzes whether required physical education in elementary and/or middle school is associated with lower rates of obesity among U.S. high school students, with an emphasis on those living in Kentucky
Cooperative Binding of Heat Shock Factor to the Yeast \u3ci\u3eHSP82\u3c/i\u3e Promoter In Vivo and In Vitro
revious work has shown that heat shock factor (HSF) plays a central role in remodeling the chromatin structure of the yeastHSP82 promoter via constitutive interactions with its high-affinity binding site, heat shock element 1 (HSE1). The HSF-HSE1 interaction is also critical for stimulating both basal (noninduced) and induced transcription. By contrast, the function of the adjacent, inducibly occupied HSE2 and -3 is unknown. In this study, we examined the consequences of mutations in HSE1, HSE2, and HSE3 on HSF binding and transactivation. We provide evidence that in vivo, HSF binds to these three sites cooperatively. This cooperativity is seen both before and after heat shock, is required for full inducibility, and can be recapitulated in vitro on both linear and supercoiled templates. Quantitative in vitro footprinting reveals that occupancy of HSE2 and -3 by Saccharomyces cerevisiae HSF (ScHSF) is enhanced ∼100-fold through cooperative interactions with the HSF-HSE1 complex. HSE1 point mutants, whose basal transcription is virtually abolished, are functionally compensated by cooperative interactions with HSE2 and -3 following heat shock, resulting in robust inducibility. Using a competition binding assay, we show that the affinity of recombinant HSF for the full-length HSP82promoter is reduced nearly an order of magnitude by a single-point mutation within HSE1, paralleling the effect of these mutations on noninduced transcript levels. We propose that the remodeled chromatin phenotype previously shown for HSE1 point mutants (and lost in HSE1 deletion mutants) stems from the retention of productive, cooperative interactions between HSF and its target binding sites
Flows and Solitary Waves in Unitary Matrix Models with Logarithmic Potentials
We investigate unitary one-matrix models coupled to bosonic quarks. We derive
a flow equation for the square-root of the specific heat as a function of the
renormalized quark mass. We show numerically that the flows have a finite
number of solitary waves, and we postulate that their number equals the number
of quark flavors. We also study the nonperturbative behavior of this theory and
show that as the number of flavors diverges, the flow does not reach
two-dimensional gravity.Comment: 26 pages + 4 figure
Solitons in Noncommutative Gauge Theory
We present a unified treatment of classical solutions of noncommutative gauge
theories. We find all solutions of the noncommutative Yang-Mills equations in 2
dimensions; and show that they are labelled by two integers -- the rank of
gauge group and the magnetic charge. The magnetic vortex solutions are unstable
in 2+1 dimensions, but correspond to the full, stable BPS solutions of N=4 U(1)
noncommutative gauge theory in 4 dimensions, that describes N infinite D1
strings that pierce a D3 brane at various points, in the presence of a
background B field in the Seiberg-Witten limit. We discuss the behaviour of
gauge invariant observables in the background of the solitons. We use these
solutions to construct a panoply of BPS and non-BPS solutions of supersymmetric
gauge theories that describe various configurations of D-branes. We analyze the
instabilities of the non-BPS solutions. We also present an exact analytic
solution of noncommutative gauge theory that describes a U(2) monopole.Comment: 37pp. harvmac big mod
Dynamics of Strings in Noncommutative Gauge Theory
We continue our study of solitons in noncommutative gauge theories and
present an extremely simple BPS solution of N=4 U(1) noncommutative gauge
theory in 4 dimensions, which describes N infinite D1 strings that pierce a D3
brane at various points, in the presence of a background B-field in the
Seiberg-Witten limit. We call this solution the N-fluxon. For N=1 we calculate
the complete spectrum of small fluctuations about the fluxon and find three
kinds of modes: the fluctuations of the superstring in 10 dimensions arising
from fundamental strings attached to the D1strings, the ordinary particles of
the gauge theory in 4 dimensions and a set of states with discrete spectrum,
localized at the intersection point--- corresponding to fundamental strings
stretched between the D1string and the D3 brane. We discuss the fluctuations
about theN-fluxon as well and derive explicit expressions for the amplitudes of
interactions between these various modes. We show that translations in
noncommutative gauge theories are equivalent to gauge transformations (plus a
constant shift of the gauge field) and discuss the implications for the
translational zeromodes of our solitons. We also find the dyonic versions of
N-fluxon, as well as of our previous string-monopole solution.Comment: 30pp. ; v2. references added, a few typos correcte
Monopoles and Strings in Noncommutative Gauge Theory
We study some non-perturbative aspects of noncommutative gauge theories. We
find analytic solutions of the equations of motion, for noncommutative U(1)
gauge theory, that describe magnetic monopoles with a finite tension string
attached. These solutions are non-singular, finite and sourceless. We identify
the string with the projection of a D-string ending on a D3-brane in the
presence of a constant B-field.Comment: harvmac, 37 pp; v2. tension matched, typos corrected, refs adde
Gravitational effects in ultrahigh-energy string scattering
Ultrahigh-energy string scattering is investigated to clarify the relative
role of string and gravitational effects, and their possible contributions to
nonlocal behavior. Different regimes can be characterized by varying the impact
parameter at fixed energy. In the regime where momentum transfers reach the
string scale, string effects appear subdominant to higher-loop gravitational
processes, approximated via the eikonal. At smaller impact parameters,
"diffractive" or "tidal" string excitation leads to processes dominated by
highly excited strings. However, new evidence is presented that these
excitation effects do not play a direct role in black hole formation, which
corresponds to breakdown of gravitational perturbation theory and appears to
dominate at sufficiently small impact parameters. The estimated amplitudes
violate expected bounds on high-energy behavior for local theories.Comment: 19 pages, harvmac. v2: fixed typos, added refs and discussion of
longitudinal spread. v3: minor changes to agree with published versio
Two-Matrix model with ABAB interaction
Using recently developed methods of character expansions we solve exactly in
the large N limit a new two-matrix model of hermitean matrices A and B with the
action S={1\over 2}(\tr A^2+\tr B^2)-{\alpha\over 4}(\tr A^4+\tr B^4)
-{\beta\over 2} \tr(AB)^2. This model can be mapped onto a special case of the
8-vertex model on dynamical planar graphs. The solution is parametrized in
terms of elliptic functions. A phase transition is found: the critical point is
a conformal field theory with central charge c=1 coupled to 2D quantum gravity.Comment: harvmac, 24 pages, 5 figures (1 color figure
Nurse Anesthetists in Southeastern Kentucky: A Survey of Supply Versus Demand
Examines the geographic maldistribution of nurse anesthetists in Kentucky and the status of their positions and vacancies at all 19 hospitals in the southeastern part of the state. UK Center for Excellence in Rural Health-Hazard researchers found that southeastern Kentucky has 12.5 percent of Kentucky’s total population and performs 11.5 percent of the state’s total surgeries - but has only 6.5 percent of the state’s total resident nurse anesthetists
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