1,740 research outputs found
An Analysis of Office Market Rents: Parameter Constancy and Unobservable Variables
This paper reexamines variations in office building rents using data for a six-year period in a medium-sized city. Previous literature has relied on estimates using OLS estimation of standard fixed-effects models. We test for structural shifts and parameter constancy using random effects on heteroscedastic-autoregressive models and we find that structural shifts occur. Overall, the rent adjustment process does not remain unchanged across different time periods or submarkets.
Precision spectroscopy with two correlated atoms
We discuss techniques that allow for long coherence times in laser
spectroscopy experiments with two trapped ions. We show that for this purpose
not only entangled ions prepared in decoherence-free subspaces can be used but
also a pair of ions that are not entangled but subject to the same kind of
phase noise. We apply this technique to a measurement of the electric
quadrupole moment of the 3d D5/2 state of 40Ca+ and to a measurement of the
linewidth of an ultrastable laser exciting a pair of 40Ca+ ions
Study of Doubly Heavy Baryon Spectrum via QCD Sum Rules
In this work, we calculate the mass spectrum of doubly heavy baryons with the
diquark model in terms of the QCD sum rules. The interpolating currents are
composed of a heavy diquark field and a light quark field. Contributions of the
operators up to dimension six are taken into account in the operator product
expansion. Within a reasonable error tolerance, our numerical results are
compatible with other theoretical predictions. This indicates that the diquark
picture reflects the reality and is applicable to the study of doubly heavy
baryons.Comment: 23 pages, 9 figures, minor corrections in expression
Solar Mikheyev-Smirnov-Wolfenstein Effect with Three Generations of Neutrinos
Under the assumption that the density variation of the electrons can be
approximated by an exponential function, the solar Mikheyev-Smirnov-Wolfenstein
effect is treated for three generations of neutrinos. The generalized
hypergeometric functions that result from the exact solution of this problem
are studied in detail, and a method for their numerical evaluation is
presented. This analysis plays a central role in the determination of neutrino
masses, not only the differences of their squares, under the assumption of
universal quark-lepton mixing.Comment: 22 pages, LaTeX, including 2 figure
Separate and combined effects of oligofructose and inulin on post-weaning coli bacillosis and weight gain: a preliminary study
Trends for a reduction in the use of dietary antibiotic growth promoters have caused increased interest in the use of alternative feed additives to maintain 'gut health' after weaning. Oligofructose and inulin are 'prebiotic' fructan-containing carbohydrates purported to enhance 'gut health' in newly-weaned pigs by altering microbial diversity (Konstantinov, et al., 2003). However, their effects using a challenge model of post-weaning colibacillosis (PWC) have never been examined. The aim of the present study was to compare the separate and combined effects of oligofructose and inulin supplementation on the occurrence of diarrhoea and the weight performance in piglets experimentally challenged with enterotoxigenic E. coli (ETEC)
From semiclassical transport to quantum Hall effect under low-field Landau quantization
The crossover from the semiclassical transport to quantum Hall effect is
studied by examining a two-dimensional electron system in an AlGaAs/GaAs
heterostructure. By probing the magneto-oscillations, it is shown that the
semiclassical Shubnikov-de Haas (SdH) formulation can be valid even when the
minima of the longitudinal resistivity approach zero. The extension of the
applicable range of the SdH theory could be due to the damping effects
resulting from disorder and temperature. Moreover, we observed plateau-plateau
transition like behavior with such an extension. From our study, it is
important to include the positive magnetoresistance to refine the SdH theory.Comment: 11 pages, 5 figure
Pressure and linear heat capacity in the superconducting state of thoriated UBe13
Even well below Tc, the heavy-fermion superconductor (U,Th)Be13 has a large
linear term in its specific heat. We show that under uniaxial pressure, the
linear heat capacity increases in magnitude by more than a factor of two. The
change is reversible and suggests that the linear term is an intrinsic property
of the material. In addition, we find no evidence of hysteresis or of latent
heat in the low-temperature and low-pressure portion of the phase diagram,
showing that all transitions in this region are second order.Comment: 5 pages, 4 figure
Quintessence from Shape Moduli
We show that shape moduli in sub-millimeter extra dimensional scenarios,
addressing the gauge hierarchy problem, can dominate the energy density of the
universe today. In our scenario, the volume of the extra dimensions is
stabilized at a sufficiently high scale to avoid conflicts with nucleosynthesis
and solar-system precision gravity experiments, while the shape moduli remain
light but couple extremely weakly to brane-localized matter and easily avoid
these bounds. Nonlocal effects in the bulk of the extra dimension generate a
potential for the shape moduli. The potential has the right form and order of
magnitude to account for the present day cosmic acceleration, in a way
analogous to models of quintessence as a pseudo Nambu-Goldstone boson.Comment: 8 pages, 1 figur
Anisotropy of the Upper Critical Field and Critical Current in Single Crystal MgB
We report on specific heat, high magnetic field transport and
susceptibility measurements on magnesium diboride single crystals. The
upper critical field for magnetic fields perpendicular and parallel to
the Mg and B planes is presented for the first time in the entire temperature
range. A very different temperature dependence has been observed in the two
directions which yields to a temperature dependent anisotropy with 5 at low temperatures and about 2 near . A peak effect is observed
in susceptibility measurements for 2 T parallel to the axis and
the critical current density presnts a sharp maximum for parallel to the
ab-plane.Comment: 6 pages, 5 figure
Measuring the Cultural Competence of Latinx Domestic Violence Service Organizations
Domestic violence (DV) represents a significant public health concern in the United States, including among Latinx populations. Despite the negative consequences associated with experiencing DV, research has shown that Latinx DV survivors may be less likely than others to utilize important services. One potential barrier is cultural competence (CC) in the provision of services specific to Latinx survivors among DV organizations. Thus, a beneficial addition to the field of DV service provision for such survivors is a better understanding and measurement of CC for this unique population. The exploratory, cross-sectional study herein presents the development and evaluation of a novel instrument for measuring the CC of DV organizations. Exploratory factor analysis was used on a purposive sample of 76 organizations in North Carolina who completed a comprehensive survey on their characteristics, practices, norms, and values. Psychometric results found best support for a 29-item, 4-factor bifactor model with both a general CC factor as well as three sub-factors. The general scale was named âGeneral Cultural Competence,â while the three sub-scales were named âOrganizational Values and Procedures,â âLatinx Knowledge and Inclusion,â and âLatinx DV Knowledge.â The final measure also demonstrated convergent validity with key organizational characteristics. Overall, higher CC scores were associated with organizations having more DV services in Spanish, a higher percentage of staff attending CC training, a higher percentage of staff attending Latinx service provision training, and a medium or greater presence in the Latinx community, and a moderate or stronger relationship with the Latinx community. The development of this measure is particularly useful in addressing knowledge gaps regarding the measurement of CC for Latinx DV services. Implications have importance for both the measurement of organizational CC and the scope of the measureâs associations with organizational, provider, and client outcomes
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