14,485 research outputs found
Prediction of Functional Sites in SCOP Domains using Dynamics Perturbation Analysis
Dynamics perturbation analysis (DPA) finds regions in a protein structure where proteins are "ticklish", i.e., where interactions cause a large change in protein dynamics. Previously, such regions were shown to predict the location of native binding sites in a docking test set, but the more general applicability of DPA to the prediction of functional sites in proteins was not shown. Here we describe the results of applying an accelerated algorithm, called Fast DPA, to predict functional sites in over 50,000 SCOP domains
Risk Taking by Mutual Funds as a Response to Incentives
This paper examines the agency conflict between mutual fund investors and mutual fund companies. Investors would like the fund company to use its judgement to maximize risk-adjusted fund returns. A fund company, however, in its desire to maximize its value as a concern has an incentive to take actions which increase the inflow of investment. We use a semiparametric model to estimate the shape of the flow-performance relationship for a sample of growth and growth and income funds observed over the 1982-1992 period. The shape of the flow-performance relationship creates incentives for fund managers to increase or decrease the riskiness of the fund which are dependent on the fund's year-to-date return. Using a new dataset of mutual fund portfolios which includes equity portfolio holdings for September and December of the same year, we show that mutual funds do alter their portfolio riskiness between September and December in a manner consistent with these risk incentives.
SOCIOLOGICAL NEEDS OF FARMERS FACING SEVERE ECONOMIC PROBLEMS
Community/Rural/Urban Development,
Spectroscopic Confirmation of the Dwarf Galaxies Hydra II and Pisces II and the Globular Cluster Laevens 1
We present Keck/DEIMOS spectroscopy of stars in the recently discovered Milky
Way satellites Hydra II, Pisces II, and Laevens 1. We measured a velocity
dispersion of 5.4 (+3.6 -2.4) km/s for Pisces II, but we did not resolve the
velocity dispersions of Hydra II or Laevens 1. We marginally resolved the
metallicity dispersions of Hydra II and Pisces II but not Laevens 1.
Furthermore, Hydra II and Pisces II obey the luminosity-metallicity relation
for Milky Way dwarf galaxies ( = -2.02 +/- 0.08 and -2.45 +/- 0.07,
respectively), whereas Laevens 1 does not ( = -1.68 +/- 0.05). The
kinematic and chemical properties suggest that Hydra II and Pisces II are dwarf
galaxies, and Laevens 1 is a globular cluster. We determined that two of the
previously observed blue stars near the center of Laevens 1 are not members of
the cluster. A third blue star has ambiguous membership. Hydra II has a radial
velocity = 303.1 +/- 1.4 km/s, similar to the leading arm of the
Magellanic stream. The mass-to-light ratio for Pisces II is 370 (+310 -240)
M_sun/L_sun. It is not among the most dark matter-dominated dwarf galaxies, but
it is still worthy of inclusion in the search for gamma rays from dark matter
self-annihilation.Comment: Accepted to ApJ. v2 has been revised in response to the referee's
repor
U(1) Axial Symmetry and Correlation Functions in the High Temperature Phase of QCD
Simple group-theoretical arguments are used to demonstrated that in the high
temperature (chirally restored) phase of QCD with N massless flavours, all
n-point correlation functions of quark bilinears are invariant under U(1) axial
transformations provided n < N. In particular this implies that the two-point
correlation function in the eta' channel is identical to that in the pion
channel for N > 2. Unlike previous work, this result does not depend on the
topological properties of QCD and can be formulated without explicit reference
to functional integrals.Comment: 3 pages, RevTe
Classification of Generalized Multiresolution Analyses
We discuss how generalized multiresolution analyses (GMRAs), both classical
and those defined on abstract Hilbert spaces, can be classified by their
multiplicity functions and matrix-valued filter functions . Given a
natural number valued function and a system of functions encoded in a
matrix satisfying certain conditions, a construction procedure is described
that produces an abstract GMRA with multiplicity function and filter
system . An equivalence relation on GMRAs is defined and described in terms
of their associated pairs . This classification system is applied to
classical examples in as well as to previously studied
abstract examples.Comment: 18 pages including bibliograp
Covering Kids & Families Evaluation: Strategies for Sustaining CKF: Interim Synthesis of Evaluation Findings
Explores state grantees' and coalitions' views on the sustainability of their efforts to help eligible families enroll in public health insurance after RWJF funding ends, the permanence of the changes effected, and their implications for CKF activities
Keck Spectroscopy of the Gravitational Lens System PG 1115+080: Redshifts of the Lensing Galaxies
The quadruple system PG 1115+080 is the second gravitational lens with a
reported measurement of the Hubble constant. In addition to the primary lens,
three nearby galaxies are believed to contribute significantly to the lensing
potential. In this paper we report accurate redshifts for all four galaxies and
show that they belong to a single group at z_d = 0.311. This group has very
similar properties to Hickson's compact groups of galaxies found at lower
redshifts. We briefly discuss implications for the existing lens models and
derive H_0 = 52 +/- 14 km/s/Mpc.Comment: revised to use the updated model of Keeton & Kochanek
(astro-ph/9611216) and to correct the velocity dispersion of the group; 10
pages including 2 eps figures and 2 tables. Submitted to the Astronomical
Journa
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