2,188 research outputs found
Finding pseudo families in women's prisons: fact and fantasy
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on October 26, 2007)Vita.Includes bibliographical references.Thesis (M.A.) University of Missouri-Columbia 2007.Dissertations, Academic -- University of Missouri--Columbia -- Sociology.This paper examines prison literature concerning women's facilities, focusing on the years 1960-1979. Sixteen specific pieces of literature are examined focusing on three claims in respect to sexuality among the incarcerated women: 1. If the sixteen works include an operationalized definition of homosexuality; 2. What terminology the authors use interchangeably with homosexuality; 3. What evidentiary support do the authors use to support their claims concerning the incidence of homosexuality. The goals of the paper are to collect women's prison literature from the aforementioned time span and cast a critical light on this existing literature. I suggest that this literature should be examined from a new lens; possibly a feminist or queer theory lens to fully address the previous assertions of homosexuality
Terahertz photoresponse of a quantum Hall edge-channel diode
The Teraherz (THz) photoresponse of a two-dimensional electron gas in the
quantum Hall regime is investigated. We use a sample structure which is
topologically equivalent to a Corbino geometry combined with a cross-gate
technique. This quasi-Corbino geometry allows us to directly investigate the
THz-induced transport between adjacent edge-states, thus avoiding bulk effects.
We find a pronounced photo voltage at zero applied bias, which rapidly
decreases when an external current bias is applied. The photo voltage and its
dependence on the bias current can be described using the model of an
illuminated photodiode, resulting from the reconstruction of the Landau bands
at the sample edge. Using the sample as a detector in a Fourier transform
spectrometer setup, we find a resonant response from which we extract a reduced
effective cyclotron mass. The findings support a non-bolometric mechanism of
the induced photo voltage and the proposed edge-channel diode model.Comment: 5 pages, 5 eps-figures, accepted for Phys. Rev.
Control of many electron states in semiconductor quantum dots by non-Abelian vector potentials
Adiabatic time evolution of degenerate eigenstates of a quantum system
provides a means for controlling electronic states since mixing between
degenerate levels generates a matrix Berry phase. In the presence of spin-orbit
coupling in n-type semiconductor quantum dots the electron Hamiltonian is
invariant under time reversal operation and the many body groundstate may be
doubly degenerate. This double degeneracy can generate non-Abelian vector
potentials when odd number of electrons are present. We find that the
antisymmetry of many electron wavefunction has no effect on the matrix Berry
phase. We have derived equations that allow one to investigate the effect of
electron correlations by expressing the non-Abelian vector potentials for many
electron system in terms of single electron non-Abelian vector potentials.Comment: minor changes included, accepted in Phys. Rev.
Nonparametric Dark Energy Reconstruction from Supernova Data
Understanding the origin of the accelerated expansion of the Universe poses
one of the greatest challenges in physics today. Lacking a compelling
fundamental theory to test, observational efforts are targeted at a better
characterization of the underlying cause. If a new form of mass-energy, dark
energy, is driving the acceleration, the redshift evolution of the equation of
state parameter w(z) will hold essential clues as to its origin. To best
exploit data from observations it is necessary to develop a robust and accurate
reconstruction approach, with controlled errors, for w(z). We introduce a new,
nonparametric method for solving the associated statistical inverse problem
based on Gaussian Process modeling and Markov chain Monte Carlo sampling.
Applying this method to recent supernova measurements, we reconstruct the
continuous history of w out to redshift z=1.5.Comment: 4 pages, 2 figures, accepted for publication in Physical Review
Letter
Quantized Dispersion of Two-Dimensional Magnetoplasmons Detected by Photoconductivity Spectroscopy
We find that the long-wavelength magnetoplasmon, resistively detected by
photoconductivity spectroscopy in high-mobility two-dimensional electron
systems, deviates from its well-known semiclassical nature as uncovered in
conventional absorption experiments. A clear filling-factor dependent
plateau-type dispersion is observed that reveals a so far unknown relation
between the magnetoplasmon and the quantum Hall effect.Comment: 5 pages, 3 figure
Physical activity, obesity and mortality: does pattern of physical activity have stronger epidemiological associations?
Background
Most studies of physical activity (PA) epidemiology use behaviour measured at a single time-point. We examined whether ‘PA patterns’ (consistently low, consistently high or inconsistent PA levels over time) showed different epidemiological relationships for anthropometric and mortality outcomes, compared to single time-point measure of PA.
Methods
Data were the Danish MONICA (MONItoring Trends and Determinants in CArdiovascular Disease) study over three waves 1982–3 (time 1), 1987–8 (time 2) and 1993–4 (time 3). Associations between leisure time single time-point PA levels at time 1 and time 3, and sport and active travel at times 1 and 2 with BMI, waist, hip circumference and mortality (death from coronary heart disease (CHD) and cardiovascular disease (CVD)) were compared to ‘PA patterns’ spanning multiple time points. PA pattern classified participants’ PA as either 1) inactive or low PA at both time points; 2) moderate level PA at time 1 and high activity at time 3; or 3) a ‘mixed PA pattern’ indicating a varying levels of activity over time. Similarly, sport and active travel were also classified as indicating stable low, stable high and mixed patterns.
Results
The moderately and highly active groups for PA at times 1 and 3 had up to 1.7 cm lower increase in waist circumference compared with the inactive/low active group. Across ‘PA patterns’, ‘active maintainers’ had a 2.0 cm lower waist circumference than ‘inactive/low maintainers’. Waist circumference was inversely related to sport but not active travel. CHD risk did not vary by activity levels at time 1, but was reduced significantly by 43% for high PA at time 3 (vs ‘inactive’ group) and among ‘active maintainers’ (vs ‘inactive/low maintainers’) by 62%. ‘Sport pattern’ showed stronger reductions in mortality for cardiovascular disease and CHD deaths among sport maintainers, than the single time point measures.
Conclusions
PA patterns demonstrated a stronger association with a number of anthropometric and mortality outcomes than the single time-point measures. Operationalising PA as a sustained behavioural pattern may address some of the known under-estimation of risk for poor health in PA self-report measurements and better reflect exposure for epidemiological analysis of risk of health outcomes
An inclusion result for dagger closure in certain section rings of abelian varieties
We prove an inclusion result for graded dagger closure for primary ideals in
symmetric section rings of abelian varieties over an algebraically closed field
of arbitrary characteristic.Comment: 11 pages, v2: updated one reference, fixed 2 typos; final versio
Nonparametric Reconstruction of the Dark Energy Equation of State from Diverse Data Sets
The cause of the accelerated expansion of the Universe poses one of the most
fundamental questions in physics today. In the absence of a compelling theory
to explain the observations, a first task is to develop a robust phenomenology.
If the acceleration is driven by some form of dark energy, then, the
phenomenology is determined by the dark energy equation of state w. A major aim
of ongoing and upcoming cosmological surveys is to measure w and its time
dependence at high accuracy. Since w(z) is not directly accessible to
measurement, powerful reconstruction methods are needed to extract it reliably
from observations. We have recently introduced a new reconstruction method for
w(z) based on Gaussian process modeling. This method can capture nontrivial
time-dependences in w(z) and, most importantly, it yields controlled and
unbaised error estimates. In this paper we extend the method to include a
diverse set of measurements: baryon acoustic oscillations, cosmic microwave
background measurements, and supernova data. We analyze currently available
data sets and present the resulting constraints on w(z), finding that current
observations are in very good agreement with a cosmological constant. In
addition we explore how well our method captures nontrivial behavior of w(z) by
analyzing simulated data assuming high-quality observations from future
surveys. We find that the baryon acoustic oscillation measurements by
themselves already lead to remarkably good reconstruction results and that the
combination of different high-quality probes allows us to reconstruct w(z) very
reliably with small error bounds.Comment: 14 pages, 9 figures, 3 table
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