3,207 research outputs found
Analytical theory for proton correlations in common water ice
We provide a fully analytical microscopic theory for the proton correlations
in water ice . We compute the full diffuse elastic neutron scattering
structure factor, which we find to be in excellent quantitative agreement with
Monte Carlo simulations. It is also in remarkable qualitative agreement with
experiment, in the absence of any fitting parameters. Our theory thus provides
a tractable analytical starting point to account for more delicate features of
the proton correlations in water ice. In addition, it directly determines an
effective field theory of water ice as a topological phase.Comment: 5 pages, 3 figure
A Novel Longitudinal Mode in the Coupled Quantum Chain Compound KCuF3
Inelastic neutron scattering measurements are reported that show a new
longitudinal mode in the antiferromagnetically ordered phase of the spin-1/2
quasi-one-dimensional antiferromagnet KCuF3. This mode signals the cross-over
from one-dimensional to three-dimensional behavior and indicates a reduction in
the ordered spin moment of a spin-1/2 antiferromagnet. The measurements are
compared with recent quantum field theory results and are found to be in
excellent agreement. A feature of the data not predicted by theory is a damping
of the mode by decay processes to the transverse spin-wave branches.Comment: 9 pages of text plus 4 postscript figures (1 color
ALIENS-NATURALIZATION-THE PROMISE TO BEAR ARMS
In two recent cases, the Supreme Court has held that citizenship must be denied an applicant who is unwilling to promise unreservedly to bear arms in defense of the United States. One applicant, Douglas Clyde Macintosh, a Professor of Divinity in Yale University, who served for four years in France during the World War, stated that due to religious convictions he was unable to promise beforehand to fight unless, in his own opinion, the war was morally justifiable and in the best interests of humanity. The other, Marie Averil Bland, a minister\u27s daughter who served as a nurse in the war, stated that her religious beliefs forbade her personally bearing arms, and refused to take the oath of allegiance as interpreted without the qualifying words, as far as my conscience as a Christian will allow. Both applications were denied in the district courts, and both these decisions were reversed by the circuit court of appeals for the second circuit. A majority of the Supreme Court, speaking through Justice Sutherland, restored the holdings of the district courts. Justices Holmes, Brandeis, and Stone concurred in a dissenting opinion read by Chief Justice Hughes
Behavioral and Physiological Assessment of Zoo-Housed Heterosexual Gorilla (Gorilla gorilla gorilla) Troops with Multiple Silverbacks
Based on recognized life history traits and ecology, zoos strive to house their gorillas (Gorilla gorilla gorilla) in mixed-sex groups with one mature male or silverback, multiple females, and their offspring. However, successful captive breeding programs and a nearly 50:50 birth sex ratio has created the need to house surplus males in solitary conditions or all-male groups. It is commonly believed that male western gorillas will not tolerate one another in the presence of females; however, multi-male, mixed-sex groups have been observed in the wild. For this reason, some zoos have begun experimenting with this scenario. At the time of data collection, only four of the 51 institutions housing gorillas in the North American Species Survival Plan® population housed multi-male, mixed sex groups. Chapter one documents the activity budgets of two of these multi-male groups and compares them to those of two traditional family troops. Overall behavior repertoire was similar between group type, though more locomoting and aberrant behaviors were exhibited by individuals in the multi-silverback groups. Interaction between the silverbacks varied greatly between the multi-male groups which suggests there could be multiple models of success for these groups. However, further insight is needed to determine why some multi-male groups are successful while others are not. Therefore, the second chapter outlines the results of a multi-institutional survey which covered the recent history of multi-male, mixed-sex groups in North American zoos. The goal of the survey was to determine potential factors associated with silverback compatibility. Results indicate that there is an association between successful multi-male, mixed-sex groups and some life history factors including the relatedness of the males, their rearing histories, and the time at which they were introduced. This research offers insight into a potential gorilla social assemblage that has been underutilized in zoo settings
RECOGNITION CASES IN AMERICAN COURTS, 1923-1930
Although the Soviets have maintained complete, uninterrupted, and practically undisputed control over most of the territory of the former Russian Empire for more than ten years, the United States still refuses to recognize the Soviet government as the international representative of Russia. The first general consideration of the legal situation engendered by the policy of our government was contained in an article by Professor Edwin D. Dickinson, The Unrecognized Government or State in English and American Law,\u27\u27 which appeared in the Michigan Law Review in 1923. In view of the importance of this matter, and the number of cases involving it decided since that time? further consideration of some of the problems may be worth while. The present writer has undertaken, therefore, to review the intervening cases
Measurement of pilot describing functions in single-controller multiloop tasks
Measurement of pilot describing functions in single controller multiloop task
Agreeing to supervise
An analysis of the literature identifying the factors related to satisfactory completion of a doctoral degree and the implications for matching supervisors with students
Statistical Uncertainties in Temperature Diagnostics for Hot Coronal Plasma Using the ASCA SIS
Statistical uncertainties in determining the temperatures of hot (0.5 keV to
10 keV) coronal plasmas are investigated. The statistical precision of various
spectral temperature diagnostics is established by analyzing synthetic ASCA
Solid-state Imaging Spectrometer (SIS) CCD spectra. The diagnostics considered
are the ratio of hydrogen-like to helium-like line complexes of
elements, line-free portions of the continuum, and the entire spectrum. While
fits to the entire spectrum yield the highest statistical precision, it is
argued that fits to the line-free continuum are less susceptible to atomic data
uncertainties but lead to a modest increase in statistical uncertainty over
full spectral fits. Temperatures deduced from line ratios can have similar
accuracy but only over a narrow range of temperatures. Convenient estimates of
statistical accuracies for the various temperature diagnostics are provided
which may be used in planning ASCA SIS observations.Comment: postscript file of 8 pages+3 figures; 4 files tarred, compressed and
uuencoded. To appear in the Astrophysical Journal Letters; contents copyright
1994 American Astronomical Societ
Internal construct validity of the Warwick-Edinburgh Mental Well-being Scale (WEMWBS): a Rasch analysis using data from the Scottish Health Education Population Survey
Background: The Warwick-Edinburgh Mental Well-Being Scale (WEMWBS) was developed to meet demand for instruments
to measure mental well-being. It comprises 14 positively phrased Likert-style items and fulfils classic criteria for scale development. We report here the internal construct validity of WEMWBS from the perspective of the Rasch measurement model.
Methods: The model was applied to data collected from 779 respondents in Wave 12 (Autumn 2006) of the Scottish Health
Education Population Survey. Respondents were aged 16–74 (average 41.9) yrs.
Results: Initial fit to model expectations was poor. The items 'I've been feeling good about myself', 'I've been interested in new things' and 'I've been feeling cheerful' all showed significant misfit to model expectations, and were deleted. This led to a marginal improvement in fit to the model. After further analysis, more items were deleted and a strict unidimensional seven item scale (the Short Warwick Edinburgh Mental Well-Being Scale (SWEMWBS)) was resolved. Many items deleted because of misfit with
model expectations showed considerable bias for gender. Two retained items also demonstrated bias for gender but, at the
scale level, cancelled out. One further retained item 'I've been feeling optimistic about the future' showed bias for age. The correlation between the 14 item and 7 item versions was 0.954. Given fit to the Rasch model, and strict unidimensionality, SWEMWBS provides an interval scale estimate of mental well-being.
Conclusion: A short 7 item version of WEMWBS was found to satisfy the strict unidimensionality expectations of the Rasch model, and be largely free of bias. This scale, SWEMWBS, provides a raw score-interval scale transformation for use in parametric procedures. In terms of face validity, SWEMWBS presents a more restricted view of mental well-being than the 14 item WEMWBS, with most items representing aspects of psychological and eudemonic well-being, and few covering hedonic well-being or affect. However, robust measurement properties combined with brevity make SWEMWBS preferable to WEMWBS at present for monitoring mental well-being in populations. Where face validity is an issue there remain arguments for continuing to collect data on the full 14 item WEMWBS
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