2,687 research outputs found
Improved conditioning of the Floater--Hormann interpolants
The Floater--Hormann family of rational interpolants do not have spurious
poles or unattainable points, are efficient to calculate, and have arbitrarily
high approximation orders. One concern when using them is that the
amplification of rounding errors increases with approximation order, and can
make balancing the interpolation error and rounding error difficult. This
article proposes to modify the Floater--Hormann interpolants by including
additional local polynomial interpolants at the ends of the interval. This
appears to improve the conditioning of the interpolants and allow higher
approximation orders to be used in practice.Comment: 13 pages, 4 figures, 1 tabl
The Rising Stellar Velocity Dispersion of M87 from Integrated Starlight
We have measured the line-of-sight velocity distribution from integrated
stellar light at two points in the outer halo of M87 (NGC 4486), the
second-rank galaxy in the Virgo Cluster. The data were taken at R = 480" ( kpc) and R = 526" ( kpc) along the SE major axis. The second
moment for a non-parametric estimate of the full velocity distribution is km/s and km/s respectively. There is intriguing evidence
in the velocity profiles for two kinematically distinct stellar components at
the position of our pointing. Under this assumption we employ a two-Gaussian
decomposition and find the primary Gaussian having rest velocities equal to M87
(consistent with zero rotation) and second moments of km/s and
km/s respectively. The asymmetry seen in the velocity profiles
suggests that the stellar halo of M87 is not in a relaxed state and confuses a
clean dynamical interpretation. That said, either measurement (full or two
component model) shows a rising velocity dispersion at large radii, consistent
with previous integrated light measurements, yet significantly higher than
globular cluster measurements at comparable radial positions. These integrated
light measurements at large radii, and the stark contrast they make to the
measurements of other kinematic tracers, highlight the rich kinematic
complexity of environments like the center of the Virgo Cluster and the need
for caution when interpreting kinematic measurements from various dynamical
tracers.Comment: 16 pages, 5 figures; accepted for publication in The Astrophysical
Journa
Healthcare Employees’ Perceptions on the Effects of Internal Audits
With limited research on the perceptions of internal audits, this study was
able to add more literature to the subject. The study’s aim was to survey
employee perceptions of the effects of internal audits. This study will provide organizations with results pertaining to how employees perceive the usefulness of internal audits. The study team conducted a single-site study and invited the healthcare organization\u27s employee population to participate in the study. The survey captured 40 responses from 361 invitees (11%). The survey explored the perceptions on six categories of internal audits: Efficiency, Ethical Behavior, Effectiveness, Auidotr-Auditee Relationship Exchange, Learning from Audit, and Top Management Support. Each category\u27s effect on internal audits was weighed by the “Strongly Agree” selection. 1.) 84 (29.9%) Top management, 2.) 55 (19.6%) Learning from Audit, 3.) 48 (17.1%) Auditor-Auditee Relationship Exchange, 4.) 42 (14.9%) Efficiency, 5.) 38 (13.5%) Ethical Behavior, and 6.) 14 (4.9%) Effectiveness. Furthermore, each category received its top response count for the selection of “Agree”. Therefore it was quite evident that each category is perceived to be an effect of internal audits. The survey results of this study can guide organizations on key areas of internal audits
Basis functions on the grain boundary space: Theory
With the increasing availability of experimental and computational data
concerning the properties and distribution of grain boundaries in
polycrystalline materials, there is a corresponding need to efficiently and
systematically express functions on the grain boundary space. A grain boundary
can be described by the rotations applied to two grains on either side of a
fixed boundary plane, suggesting that the grain boundary space is related to
the space of rotations. This observation is used to construct an orthornormal
function basis, allowing effectively arbitrary functions on the grain boundary
space to be written as linear combinations of the basis functions. Moreover, a
procedure is developed to construct a smaller set of basis functions consistent
with the crystallographic point group symmetries, grain exchange symmetry, and
the null boundary singularity. Functions with the corresponding symmetries can
be efficiently expressed as linear combinations of the symmetrized basis
functions. An example is provided that shows the efficacy of the symmetrization
procedure
Classification of atomic environments via the Gromov-Wasserstein distance
Interpreting molecular dynamics simulations usually involves automated
classification of local atomic environments to identify regions of interest.
Existing approaches are generally limited to a small number of reference
structures and only include limited information about the local chemical
composition. This work proposes to use a variant of the Gromov-Wasserstein (GW)
distance to quantify the difference between a local atomic environment and a
set of arbitrary reference environments in a way that is sensitive to atomic
displacements, missing atoms, and differences in chemical composition. This
involves describing a local atomic environment as a finite metric measure
space, which has the additional advantages of not requiring the local
environment to be centered on an atom and of not making any assumptions about
the material class. Numerical examples illustrate the efficacy and versatility
of the algorithm
Trends in Scottish newborn screening programme for congenital hypothyroidism 1980-2014: strategies for reducing age at notification after initial and repeat sampling
Objectives: To determine ages at first capillary sampling and notification and age at notification after second sampling in Scottish newborns referred with elevated thyroid-stimulating hormone (TSH).
Subjects and methods: Referrals between 1980 and 2014 inclusive were grouped into seven 5-year blocks and analysed according to agreed standards.
Results: Of 2 116 132 newborn infants screened, 919 were referred with capillary TSH elevation ≥8 mU/L of whom 624 had definite (606) or probable (18) congenital hypothyroidism. Median age at first sampling fell from 7 to 5 days between 1980 and 2014 (standard 4–7 days), with 22, 8 and 3 infants sampled >7 days during 2000–2004, 2005–2009 and 2010–2014. Median age at notification was consistently ≤14 days, range falling during 2000–2004, 2005–2009 and 2010–2014 from 6 to 78, 7–52 and 7–32 days with 12 (14.6%), 6 (5.6%) and 5 (4.3%) infants notified >14 days. However 18/123 (14.6%) of infants undergoing second sampling from 2000 onwards breached the ≤26-day standard for notification. By 2010–2014, the 91 infants with confirmed congenital hypothyroidism had shown favourable median age at first sample (5 days) with start of treatment (10.5 days) approaching age at notification.
Conclusion: Most standards for newborn thyroid screening are being met by the Scottish programme, but there is a need to reduce age range at notification, particularly following second sampling. Strategies to improve screening performance include carrying out initial capillary sampling as close to 96 hours as possible; introducing 6-day laboratory reporting and use of electronic transmission for communicating repeat requests
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