1,841 research outputs found
The SBF Survey of Galaxy Distances. II. Local and Large-Scale Flows
We present analysis of local large scale flows using the Surface Brightness
Fluctuation (SBF) Survey for the distances to 300 early-type galaxies. Our
models of the distribution function of mean velocity and velocity dispersion at
each point in space include a uniform thermal velocity dispersion and spherical
attractors whose position, amplitude, and radial shape are free to vary. Our
fitting procedure performs a maximum likelihood fit of the model to the
observations. We obtain a Hubble constant of Ho = 77 +/- 4 +/- 7 km/s/Mpc, but
a uniform Hubble flow is not acceptable fit to the data. Inclusion of two
attractors, one of whose fit location coincides with the Virgo cluster and the
other whose fit location is slightly beyond the Centaurus clusters nearly
explain the peculiar velocities, but the quality of the fit can be further
improved by the addition of a quadrupole correction to the Hubble flow.
Although the dipole and quadrupole may be genuine manifestations of more
distant density fluctuations, we find evidence that they are more likely due to
non-spherical attractors. We find no evidence for bulk flows which include our
entire survey volume (R < 3000 km/s); our volume is at rest with respect to the
CMB. The fits to the attractors both have isothermal radial profiles (v ~ 1/r)
over a range of overdensity between about 10 and 1, but fall off more steeply
at larger radius. The best fit value for the small scale, cosmic thermal
velocity is 180 +/- 14 km/s.Comment: 37 pages, AASTeX Latex, including 30 Postscript figures, submitted to
Astrophysical Journal, July 2, 199
The Cognitive Daisy – a novel method for recognising the cognitive status of older adults in residential care: Innovative practice
The Cognitive Daisy (COG-D) is an innovative assessment system created to provide
healthcare staff with an instant snapshot of the cognitive status of older adults in
residential care. The COG-D comprises a flower head consisting of 15 colour coded
petals depicting information about: visual-spatial perception, comprehension,
communication, memory and attention. This study confirmed the practicality of the
COG-D protocol for assessing cognition in a sample of 33 older adults living in
residential care and endorsed the use of the COG-D as a tool for recognising the
cognitive status of care home residents
Performance Assessment of ESL and EFL Students
Thirteen prototypical performance tasks were selected from over 100 based on their generic appropriateness for the target population and on posited difficulty levels (associated with plus or niinus values for linguistic code command, cognitive operations, and communicative adaptation, as discussed in Norris, Brown, Hudson, & Yoshioka, 1998, after Skehan, 1996, 1998). These l3 tasks were used to create three test forms (with one anchor task common to all forms), two for use in an ESL setting at the University of Hawai'i, and one for use in an EFL setting at Kanda University of International Studies in Japan. In addition, two sets ofrating scales were created based on task-dependent and task-independent categories. For each individual task, the criteria for the task-dependent categories were created in consultation with an advanced language learner, a language teacher, and a non-ESL teacher, all ofwhom were well-acquainted with the target population and the prototype tasks. These criteria for success were allowed to differ from task to task depending on the input ofour consultants. The task-independent categories were created for each of three theoretically motivated components of task difficulty in terms of the adequacy of: (linguistic) code command, cognitive operations, and communicative adaptation. A third rating scale was developed for examinees to rate their own performance in terms of their familiarity with the task, their performance on the task, and the difficulty of the task. Pilot data were gathered from ESL and EFL students at a wide range of proficiency levels. Their performances were scored by raters using the task dependent and task-independent criteria. Analyses included descriptive statistics, reliability estimates (interrater, Cronbach alpha, etc.), correlational analysis, and implicational scale analysis. The results are interpreted and discussed in terms of: (a) the distributions ofscores for the task-dependent and task-independent ratings, (b) test reliability and ways to improve the consistency of measurement, and (c) test validify and the relationship of our task-based test to theory
Assessing cementation in the El Capitan Reef Complex and Lincolnshire Limestone using ^(13)C-^(18)O bond abundances in carbonates
The Permian El Capitan and Jurassic Lincolnshire limestones have been intensely studied for their stratigraphy,
depositional setting and paleoecology. Nevertheless, the diagenetic development of these two units remains
controversial, particularly with regard to diagenetic carbonate formation. Calcite cement phases have previously been
characterized via δ^(18)O and δ^(13)C in order to determine precipitation temperatures and carbon sources, however, these
results have lead to conflicting hypotheses
libEnsemble: A Library to Coordinate the Concurrent Evaluation of Dynamic Ensembles of Calculations
Almost all applications stop scaling at some point; those that don't are
seldom performant when considering time to solution on anything but
aspirational/unicorn resources. Recognizing these tradeoffs as well as greater
user functionality in a near-term exascale computing era, we present
libEnsemble, a library aimed at particular scalability- and
capability-stretching uses. libEnsemble enables running concurrent instances of
an application in dynamically allocated ensembles through an extensible Python
library. We highlight the structure, execution, and capabilities of the library
on leading pre-exascale environments as well as advanced capabilities for
exascale environments and beyond
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Effective separation of Am(III) and Eu(III) from HNO3 solutions using CyMe4-BTPhen-functionalized silica-coated magnetic nanoparticles
It has been shown that CyMe4-BTPhen-functionalized silica-coated maghemite (c-Fe2O3) magnetic nanoparticles (MNPs) are capable of quantitative separation of Am(III) from Eu(III) from HNO3 solutions. These MNPs also show a small but significant selectivity for Am(III) over Cm(III) with a separation factor of around 2 in 4 M HNO3. The water molecule in the cavity of the BTPhen may also play an
important part in the selectivity
Relative Energy Requirements for an Erythemal Response of Skin to Monochromatic Wave Lengths of Ultraviolet Present in the Solar Spectrum**From the Departments of Dermatology and Pathology, Baylor University College of Medicine, Houston, Texas.
Evolution of Terrestrial Habitat in Manophylax Species (Trichoptera:Apataniidae), with a New Species from Alaska
The genus Manophylax (Trichoptera:Apataniidae) contains 3 species from the Nearctic Region and 3 species from Japan. A 7th species of Manophylax new for science is described and illustrated from Alaska. Habitats of larvae and pupae of the different Manophylax species are either mostly hygropetric or mostly terrestrial. Phylogenetic analysis infers 3 principal species groups occurring in the eastern and western Nearctic and eastern Palearctic Biogeographic Regions. The habitat of the western Nearctic M. annulatus Species Group is mostly hygropetric and that of the eastern Nearctic M. altus and eastern Palearctic M. futabae Species Groups are mostly terrestrial. The phylogeny suggests that the mostly terrestrial habitat evolved through a mostly hygropetric habitat. The phylogeny also implies that the eastern Nearctic and eastern Palearctic species share a more recent common ancestor than they share with the western Nearctic species, a result further supporting a commonly observed historical biogeographic pattern for these regions. Madeophylax Huryn and Wallace is redefined as a subgenus of Manophylax Wiggins, including the species of the M. altus and M. futabae Species Groups. Keys to adult males, females, larvae, and pupae of the 4 North American species of Manophylax are included
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