5,389 research outputs found
Assessing a Decade of Interstate Bank Branching
Since its inception, US. banking regulation has effectively prohibited a bank from opening or owning a branch located outside of its home state, commonly referred to as interstate branching. Only since the passage of the Riegle-Neal Interstate Banking and Branching Efficiency Act (IBBEA) of 1994 have banks been able to engage in interstate branching, albeit still subject to significant state restrictions. Despite IBBEA \u27s removal of those barriers, it still allowed the states to impose anticompetitive restrictions governing the entry of out-of-state banks through the establishment of branch offices. As a result, states that were opposed to entry used IBBEA to erect barriers to out-of-state branch entry. This Article describes the changes in federal and state interstate branching law since passage of IBBEA and reviews how initial (1994-1997) and evolving (1998-2005) interstate branching laws affect out-of-state branch growth in a state\u27s banking market. We provide a detailed fifty-state plus the District of Columbia survey of each state\u27s initial interstate branch banking restrictions and changes to those provisions between 1994 and 2005. Based on the results of this survey, we employ regression analysis to determine whether there was an empirical association between restrictive state regulation and out-of-state branch banking entry. We conclude that anticompetitive state provisions restricted out-of-state growth when those provisions were more restrictive than the provisions set by neighboring states
NGC 7789: An Open Cluster Case Study
We have obtained high-resolution spectra of 32 giants in the open cluster NGC
7789 using the Wisconsin-Indiana-Yale-NOAO Hydra spectrograph. We explore
differences in atmospheric parameters and elemental abundances caused by the
use of the linelist developed for the Gaia-ESO Survey (GES) compared to one
based on Arcturus used in our previous work. [Fe/H] values decrease when using
the GES linelist instead of the Arcturus-based linelist; these differences are
probably driven by systematically lower (~ -0.1 dex) GES surface gravities.
Using the GES linelist we determine abundances for 10 elements - Fe, Mg, Si,
Ca, Ti, Na, Ni, Zr, Ba, and La. We find the cluster's average metallicity
[Fe/H] = 0.03 +/- 0.07 dex, in good agreement with literature values, and a
lower [Mg/Fe] abundance than has been reported before for this cluster (0.11
+/- 0.05 dex). We also find the neutron-capture element barium to be highly
enhanced - [Ba/Fe] = +0.48 +/- 0.08 - and disparate from cluster measurements
of neutron-capture elements La and Zr (-0.08 +/- 0.05 and 0.08 +/- 0.08,
respectively). This is in accordance with recent discoveries of supersolar Ba
enhancement in young clusters along with more modest enhancement of other
neutron-capture elements formed in similar environments.Comment: 15 pages, 9 figures, Table 1 typo fixe
Closure statistics in interferometric data
Interferometric visibilities, reflecting the complex correlations between
signals recorded at antennas in an interferometric array, carry information
about the angular structure of a distant source. While unknown antenna gains in
both amplitude and phase can prevent direct interpretation of these
measurements, certain combinations of visibilities called closure phases and
closure amplitudes are independent of antenna gains and provide a convenient
set of robust observables. However, these closure quantities have subtle noise
properties and are generally both linearly and statistically dependent. These
complications have obstructed the proper use of closure quantities in
interferometric analysis, and they have obscured the relationship between
analysis with closure quantities and other analysis techniques such as self
calibration. We review the statistics of closure quantities, noting common
pitfalls that arise when approaching low signal-to-noise due to the nonlinear
propagation of statistical errors. We then develop a strategy for isolating and
fitting to the independent degrees of freedom captured by the closure
quantities through explicit construction of linearly independent sets of
quantities along with their noise covariance in the Gaussian limit, valid for
moderate signal-to-noise, and we demonstrate that model fits have biased
posteriors when this covariance is ignored. Finally, we introduce a unified
procedure for fitting to both closure information and partially calibrated
visibilities, and we demonstrate both analytically and numerically the direct
equivalence of inference based on closure quantities to that based on self
calibration of complex visibilities with unconstrained antenna gains.Comment: 31 pages, 17 figure
Direct numerical simulation of homogeneous nucleation and growth in a phase-field model using cell dynamics method
Homogeneous nucleation and growth in a simplest two-dimensional phase field
model is numerically studied using the cell dynamics method. Whole process from
nucleation to growth is simulated and is shown to follow closely the
Kolmogorov-Johnson-Mehl-Avrami (KJMA) scenario of phase transformation.
Specifically the time evolution of the volume fraction of new stable phase is
found to follow closely the KJMA formula. By fitting the KJMA formula directly
to the simulation data, not only the Avrami exponent but the magnitude of
nucleation rate and, in particular, of incubation time are quantitatively
studied. The modified Avrami plot is also used to verify the derived KJMA
parameters. It is found that the Avrami exponent is close to the ideal
theoretical value m=3. The temperature dependence of nucleation rate follows
the activation-type behavior expected from the classical nucleation theory. On
the other hand, the temperature dependence of incubation time does not follow
the exponential activation-type behavior. Rather the incubation time is
inversely proportional to the temperature predicted from the theory of
Shneidman and Weinberg [J. Non-Cryst. Solids {\bf 160}, 89 (1993)]. A need to
restrict thermal noise in simulation to deduce correct Avrami exponent is also
discussed.Comment: 9 pages, 8 figures, Journal of Chemical Physics to be publishe
Factorial cumulants reveal interactions in counting statistics
Full counting statistics concerns the stochastic transport of electrons in
mesoscopic structures. Recently it has been shown that the charge transport
statistics for non-interacting electrons in a two-terminal system is always
generalized binomial: it can be decomposed into independent single-particle
events and the zeros of the generating function are real and negative. Here we
investigate how the zeros of the generating function move into the complex
plane due to interactions and demonstrate that the positions of the zeros can
be detected using high-order factorial cumulants. As an illustrative example we
consider electron transport through a Coulomb blockade quantum dot for which we
show that the interactions on the quantum dot are clearly visible in the
high-order factorial cumulants. Our findings are important for understanding
the influence of interactions on counting statistics and the characterization
in terms of zeros of the generating function provides us with a simple
interpretation of recent experiments, where high-order statistics have been
measured.Comment: 12 pages, 7 figures, Editors' Suggestion in Phys. Rev.
Abelian Yang-Mills theory on Real tori and Theta divisors of Klein surfaces
The purpose of this paper is to compute determinant index bundles of certain
families of Real Dirac type operators on Klein surfaces as elements in the
corresponding Grothendieck group of Real line bundles in the sense of Atiyah.
On a Klein surface these determinant index bundles have a natural holomorphic
description as theta line bundles. In particular we compute the first
Stiefel-Whitney classes of the corresponding fixed point bundles on the real
part of the Picard torus. The computation of these classes is important,
because they control to a large extent the orientability of certain moduli
spaces in Real gauge theory and Real algebraic geometry.Comment: LaTeX, 44 pages, to appear in Comm. Math. Phy
Black and Latino Fathers of Students With Autism: Culturally Responsive Support
Perspectives from five Black and Latino fathers of students with autism are shared from this qualitative pilot study. The fathers were asked to describe the most helpful forms of support from school counselors. One-time, semi-structured interviews were conducted and interpreted with the thematic analysis method. Results suggest support from other parents, and specifically from other fathers, with shared experiences is most helpful. Recommendations for school counseling practice and research are shared
The complex geometry of holographic flows of quiver gauge theories
We argue that the complete Klebanov-Witten flow solution must be described by
a Calabi-Yau metric on the conifold, interpolating between the orbifold at
infinity and the cone over T^(1,1) in the interior. We show that the complete
flow solution is characterized completely by a single, simple, quasi-linear,
second order PDE, or "master equation," in two variables. We show that the
Pilch-Warner flow solution is almost Calabi-Yau: It has a complex structure, a
hermitian metric, and a holomorphic (3,0)-form that is a square root of the
volume form. It is, however, not Kahler. We discuss the relationship between
the master equation derived here for Calabi-Yau geometries and such equations
encountered elsewhere and that govern supersymmetric backgrounds with multiple,
independent fluxes.Comment: 26 pages, harvmac + amssy
AGB Sodium Abundances in the Globular Cluster 47 Tucanae (NGC 104)
A recent analysis comparing the [Na/Fe] distributions of red giant branch
(RGB) and asymptotic giant branch (AGB) stars in the Galactic globular cluster
NGC 6752 found that the ratio of Na-poor to Na-rich stars changes from 30:70 on
the RGB to 100:0 on the AGB. The surprising paucity of Na-rich stars on the AGB
in NGC 6752 warrants additional investigations to determine if the failure of a
significant fraction of stars to ascend the AGB is an attribute common to all
globular clusters. Therefore, we present radial velocities, [Fe/H], and [Na/Fe]
abundances for 35 AGB stars in the Galactic globular cluster 47 Tucanae (47
Tuc; NGC 104), and compare the AGB [Na/Fe] distribution with a similar RGB
sample published previously. The abundances and velocities were derived from
high resolution spectra obtained with the Michigan/Magellan Fiber System (M2FS)
and MSpec spectrograph on the Magellan-Clay 6.5m telescope. We find the average
heliocentric radial velocity and [Fe/H] values to be =-18.56 km s^-1
(sigma=10.21 km s^-1) and =-0.68 (sigma=0.08), respectively, in
agreement with previous literature estimates. The average [Na/Fe] abundance is
0.12 dex lower in the 47 Tuc AGB sample compared to the RGB sample, and the
ratio of Na-poor to Na-rich stars is 63:37 on the AGB and 45:55 on the RGB.
However, in contrast to NGC 6752, the two 47 Tuc populations have nearly
identical [Na/Fe] dispersion and interquartile range values. The data presented
here suggest that only a small fraction <20% of Na-rich stars in 47 Tuc may
fail to ascend the AGB. Regardless of the cause for the lower average [Na/Fe]
abundance in AGB stars, we find that Na-poor stars and at least some Na-rich
stars in 47 Tuc evolve through the early AGB phase. [abridged]Comment: Accepted for publication in the Astronomical Journal; 15 pages; 8
figures; 4 table
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