11,986 research outputs found
Defining the Relevant Market: Impacts of the Abolition of the Presumption of Market Power in Patent Tying Cases
Teaching Casual Random Blood Glucose Screening to Second-Year Dental Students
In our project, archived casual random blood glucose levels of second-year dental students who were taught the mechanics of self-testing were retrieved. Material data were analyzed by calculating means, medians, standard deviations, and ranges for 161 dental students screened by this casual and random self-monitoring of blood glucose levels as described by the American Diabetes Association’s 2008 Standards of Medical Care in Diabetes. Three types of data were assessed in this study. The first was the casual blood glucose levels of second-year dental students. The second was the data retrieved from student questionnaires regarding the value of teaching casual random blood glucose screening. The third was the U.S. dental schools’ responses regarding inclusion of casual blood glucose screening in their current curricula. Second-year dental students self-reported hypoglycemia in three instances and hyperglycemia in eight, based on current American Diabetes Association standards. Students agreed or strongly agreed that the value of teaching was informative (92.3 percent), beneficial (95 percent), and something that might be included in their practices (78.2 percent), with 19.2 percent being neutral on the inclusion. Only six U.S. dental schools reported teaching casual random glucose screening
Toward a Theory of Business
What is the purpose of business? While most agree that business minimally involves the creation of value, a blurred double image of value haunts our discussion of purpose. The image of what counts as value for a single firm is laid atop an image of what counts as value for business in general. These two images cannot match. Indeed, the resulting conceptual blurriness is a classic example of a composition fallacy. We should never mistake the properties of a part for the properties of the whole. A theory of the firm is ill equipped to handle the many expectations we hold for business practice. As such, we seek to establish the beginnings of a theory of business, one that is both empirical and normative. Offering four central propositions about the purpose, accountability, control and success of business, we close with a consideration of several important theoretical issues and practical opportunities that await us in the years ahead
The MASSIVE Survey - VIII. Stellar Velocity Dispersion Profiles and Environmental Dependence of Early-Type Galaxies
We measure the radial profiles of the stellar velocity dispersions,
, for 90 early-type galaxies (ETGs) in the MASSIVE survey, a
volume-limited integral-field spectroscopic (IFS) galaxy survey targeting all
northern-sky ETGs with absolute -band magnitude mag, or
stellar mass , within 108 Mpc. Our wide-field
107" 107" IFS data cover radii as large as 40 kpc, for which we
quantify separately the inner (2 kpc) and outer (20 kpc) logarithmic slopes
and of . While
is mostly negative, of the 56 galaxies with sufficient
radial coverage to determine we find 36% to have rising
outer dispersion profiles, 30% to be flat within the uncertainties, and 34% to
be falling. The fraction of galaxies with rising outer profiles increases with
and in denser galaxy environment, with 10 of the 11 most massive galaxies
in our sample having flat or rising dispersion profiles. The strongest
environmental correlations are with local density and halo mass, but a weaker
correlation with large-scale density also exists. The average is similar for brightest group galaxies, satellites, and isolated
galaxies in our sample. We find a clear positive correlation between the
gradients of the outer dispersion profile and the gradients of the velocity
kurtosis . Altogether, our kinematic results suggest that the increasing
fraction of rising dispersion profiles in the most massive ETGs are caused (at
least in part) by variations in the total mass profiles rather than in the
velocity anisotropy alone.Comment: Accepted/in press, MNRA
A trade-off study of tilt rotor aircraft versus helicopters using VASCOMP II and HESCOMP.
http://archive.org/details/tradeoffstudyoft00walsN
The MASSIVE Survey - VII. The Relationship of Angular Momentum, Stellar Mass and Environment of Early-Type Galaxies
We analyse the environmental properties of 370 local early-type galaxies
(ETGs) in the MASSIVE and ATLAS3D surveys, two complementary volume-limited
integral-field spectroscopic (IFS) galaxy surveys spanning absolute -band
magnitude , or stellar mass . We find these galaxies to reside in a diverse range of
environments measured by four methods: group membership (whether a galaxy is a
brightest group/cluster galaxy, satellite, or isolated), halo mass, large-scale
mass density (measured over a few Mpc), and local mass density (measured within
the th neighbour). The spatially resolved IFS stellar kinematics provide
robust measurements of the spin parameter and enable us to examine
the relationship among , , and galaxy environment. We find a
strong correlation between and , where the average
decreases from to below 0.1 with increasing mass, and the fraction
of slow rotators increases from % to 90%. We show for
the first time that at fixed , there are almost no trends between galaxy
spin and environment; the apparent kinematic morphology-density relation for
ETGs is therefore primarily driven by and is accounted for by the joint
correlations between and spin, and between and environment. A
possible exception is that the increased at high local density
is slightly more than expected based only on these joint correlations. Our
results suggest that the physical processes responsible for building up the
present-day stellar masses of massive galaxies are also very efficient at
reducing their spin, in any environment.Comment: Accepted to MNRA
Batch-iFDD for representation expansion in large MDPs
Matching pursuit (MP) methods are a promising class of feature construction algorithms for value function approximation. Yet existing MP methods require creating a pool of potential features, mandating expert knowledge or enumeration of a large feature pool, both of which hinder scalability. This paper introduces batch incremental feature dependency discovery (Batch-iFDD) as an MP method that inherits a provable convergence property. Additionally, Batch-iFDD does not require a large pool of features, leading to lower computational complexity. Empirical policy evaluation results across three domains with up to one million states highlight the scalability of Batch-iFDD over the previous state of the art MP algorithm.United States. Office of Naval Research (Grant N00014-07-1-0749)United States. Office of Naval Research (Grant N00014-11-1-0688
The MASSIVE Survey XIII -- Spatially Resolved Stellar Kinematics in the Central 1 kpc of 20 Massive Elliptical Galaxies with the GMOS-North Integral-Field Spectrograph
We use observations from the GEMINI-N/GMOS integral-field spectrograph (IFS)
to obtain spatially resolved stellar kinematics of the central kpc of
20 early-type galaxies (ETGs) with stellar masses greater than in the MASSIVE survey. Together with observations from the wide-field
Mitchell IFS at McDonald Observatory in our earlier work, we obtain
unprecedentedly detailed kinematic maps of local massive ETGs, covering a scale
of kpc. The high () signal-to-noise of the GMOS spectra
enable us to obtain two-dimensional maps of the line-of-sight velocity,
velocity dispersion , as well as the skewness and kurtosis
of the stellar velocity distributions. All but one galaxy in the sample have
profiles that increase towards the center, whereas the slope of
at one effective radius () can be of either sign. The is
generally positive, with 14 of the 20 galaxies having positive within the
GMOS aperture and 18 having positive within . The positive
and rising towards small radii are indicative of a central black
hole and velocity anisotropy. We demonstrate the constraining power of the data
on the mass distributions in ETGs by applying Jeans anisotropic modeling (JAM)
to NGC~1453, the most regular fast rotator in the sample. Despite the
limitations of JAM, we obtain a clear minimum in black hole mass,
stellar mass-to-light ratio, velocity anisotropy parameters, and the circular
velocity of the dark matter halo.Comment: Accepted to Ap
3D Spectrophotometry of Planetary Nebulae in the Bulge of M31
We introduce crowded field integral field (3D) spectrophotometry as a useful
technique for the study of resolved stellar populations in nearby galaxies. As
a methodological test, we present a pilot study with selected extragalactic
planetary nebulae (XPN) in the bulge of M31, demonstrating how 3D spectroscopy
is able to improve the limited accuracy of background subtraction which one
would normally obtain with classical slit spectroscopy. It is shown that due to
the absence of slit effects, 3D is a most suitable technique for
spectrophometry. We present spectra and line intensities for 5 XPN in M31,
obtained with the MPFS instrument at the Russian 6m BTA, INTEGRAL at the WHT,
and with PMAS at the Calar Alto 3.5m Telescope. Using 3D spectra of bright
standard stars, we demonstrate that the PSF is sampled with high accuracy,
providing a centroiding precision at the milli-arcsec level. Crowded field 3D
spectrophotometry and the use of PSF fitting techniques is suggested as the
method of choice for a number of similar observational problems, including
luminous stars in nearby galaxies, supernovae, QSO host galaxies,
gravitationally lensed QSOs, and others.Comment: (1) Astrophysikalisches Institut Potsdam, (2) University of Durham.
18 pages, 11 figures, accepted for publication in Ap
The MASSIVE Survey - X. Misalignment between Kinematic and Photometric Axes and Intrinsic Shapes of Massive Early-Type Galaxies
We use spatially resolved two-dimensional stellar velocity maps over a
field of view to investigate the kinematic features of 90
early-type galaxies above stellar mass in the MASSIVE
survey. We measure the misalignment angle between the kinematic and
photometric axes and identify local features such as velocity twists and
kinematically distinct components. We find 46% of the sample to be well aligned
(), 33% misaligned, and 21% without detectable rotation
(non-rotators). Only 24% of the sample are fast rotators, the majority of which
(91%) are aligned, whereas 57% of the slow rotators are misaligned with a
nearly flat distribution of from to . 11
galaxies have and thus exhibit minor-axis ("prolate")
rotation in which the rotation is preferentially around the photometric major
axis. Kinematic misalignments occur more frequently for lower galaxy spin or
denser galaxy environments. Using the observed misalignment and ellipticity
distributions, we infer the intrinsic shape distribution of our sample and find
that MASSIVE slow rotators are consistent with being mildly triaxial, with mean
axis ratios of and . In terms of local kinematic features,
51% of the sample exhibit kinematic twists of larger than , and 2
galaxies have kinematically distinct components. The frequency of misalignment
and the broad distribution of reported here suggest that the most
massive early-type galaxies are mildly triaxial, and that formation processes
resulting in kinematically misaligned slow rotators such as gas-poor mergers
occur frequently in this mass range.Comment: Accepted to MNRA
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