4,239 research outputs found
Wellness Project Implementation Within Houston\u27s Faith and Diabetes initiative: a Mixed Methods Study
BACKGROUND: Faith-based health promotion has shown promise for supporting healthy lifestyles, but has limited evidence of reaching scale or sustainability. In one recent such effort, volunteers from a diverse range of faith organizations were trained as peer educators to implement diabetes self-management education (DSME) classes within their communities. The purpose of this study was to identify factors associated with provision of these classes within six months of peer-educator training.
METHODS: This study used the Consolidated Framework for Implementation Research (CFIR) to identify patterns from interviews, observations, attendance records, and organizational background information. Two research team members thematically coded interview transcripts and observation memos to identify patterns distinguishing faith organizations that did, versus did not, conduct DSME classes within six months of peer-educator training. Bivariate statistics were also used to identify faith organizational characteristics associated with DSME class completion within this time frame.
RESULTS: Volunteers from 24 faith organizations received peer-educator training. Of these, 15 led a DSME class within six months, graduating a total of 132 participants. Thematic analyses yielded two challenges experienced disproportionately by organizations unable to complete DSME within six months: [1] Their peer educators experienced DSME as complex, despite substantial planning efforts at simplification, and [2] the process of engaging peer educators and leadership within their organizations was often more difficult than anticipated, despite initial communication by Faith and Diabetes organizers intended to secure informed commitments by both groups. Many peer educators were overwhelmed by training content, the responsibility required to start and sustain DSME classes, and other time commitments. Other priorities competed for time in participants\u27 lives and on organizational calendars, and scheduling processes could be slow. In an apparent dynamic of crowding out, coordination was particularly difficult in larger organizations, which were less likely than smaller organizations to complete DSME classes despite their more substantial resources.
CONCLUSIONS: Initial commitment from faith organizations\u27 leadership and volunteers may not suffice to implement even relatively short and low cost health promotion programs. Faith organizations might benefit from realistic previews about just how challenging it is to make these programs a sufficiently high organizational and individual priority
Estimating the age of fire in the Cape flora of South Africa from an orchid phylogeny
Fire may have been a crucial component in the evolution of the Cape flora of South Africa, a region characterized by outstanding levels of species richness and endemism. However, there is, to date, no critical assessment of the age of the modern fire regime in this biome. Here, we exploit the presence of two obligate post-fire flowering clades in the orchid genus Disa, in conjunction with a robust, well-sampled and dated molecular phylogeny, to estimate the age by which fire must have been present. Our results indicate that summer drought (winter rainfall), the fire regime and the fynbos vegetation are several million years older than currently suggested. Summer drought and the fynbos vegetation are estimated to date back to at least the Early Miocene (ca 19.5 Ma). The current fire regime may have been established during a period of global cooling that followed the mid-Miocene Climatic Optimum (ca 15 Ma), which led to the expansion of open habitats and increased aridification. The first appearance of Disa species in the grassland biome, as well as in the subalpine habitat, is in striking agreement with reliable geological and palaeontological evidence of the age of these ecosystems, thus corroborating the efficacy of our methods. These results change our understanding of the historical mechanisms underlying botanical evolution in southern Africa, and confirm the potential of using molecular phylogenies to date events for which other information is lacking or inconclusive
Reducing Zero-point Systematics in Dark Energy Supernova Experiments
We study the effect of filter zero-point uncertainties on future supernova
dark energy missions. Fitting for calibration parameters using simultaneous
analysis of all Type Ia supernova standard candles achieves a significant
improvement over more traditional fit methods. This conclusion is robust under
diverse experimental configurations (number of observed supernovae, maximum
survey redshift, inclusion of additional systematics). This approach to
supernova fitting considerably eases otherwise stringent mission calibration
requirements. As an example we simulate a space-based mission based on the
proposed JDEM satellite; however the method and conclusions are general and
valid for any future supernova dark energy mission, ground or space-based.Comment: 30 pages,8 figures, 5 table, one reference added, submitted to
Astroparticle Physic
Long-range epidemic spreading with immunization
We study the phase transition between survival and extinction in an epidemic
process with long-range interactions and immunization. This model can be viewed
as the well-known general epidemic process (GEP) in which nearest-neighbor
interactions are replaced by Levy flights over distances r which are
distributed as P(r) ~ r^(-d-sigma). By extensive numerical simulations we
confirm previous field-theoretical results obtained by Janssen et al. [Eur.
Phys. J. B7, 137 (1999)].Comment: LaTeX, 14 pages, 4 eps figure
Reticulation, Data Combination, and Inferring Evolutionary History: An Example from Danthonioideae (Poaceae)
We explore the potential impact of conflicting gene trees on inferences of evolutionary history above the species level. When conflict between gene trees is discovered, it is common practice either to analyze the data separately or to combine the data having excluded the conflicting taxa or data partitions for those taxa (which are then recoded as missing). We demonstrate an alternative approach, which involves duplicating conflicting taxa in the matrix, such that each duplicate is represented by one partition only. This allows the combination of all available data in standard phylogenetic analyses, despite reticulations. We show how interpretation of contradictory gene trees can lead to conflicting inferences of both morphological evolution and biogeographic history, using the example of the pampas grasses, Cortaderia. The characteristic morphological syndrome of Cortaderia can be inferred as having arisen multiple times (chloroplast DNA [cpDNA]) or just once (nuclear ribosomal DNA [nrDNA]). The distributions of species of Cortaderia and related genera in Australia/New Guinea, New Zealand, and South America can be explained by few (nrDNA) or several (cpDNA) dispersals between the southern continents. These contradictions can be explained by past hybridization events, which have linked gains of complex morphologies with unrelated chloroplast lineages and have erased evidence of dispersals from the nuclear genome. Given the discrepancies between inferences based on the gene trees individually, we urge the use of approaches such as ours that take multiple gene trees into accoun
Influence of synthesis conditions and processing on the cathode performance of 5V-spinel materials. Titanium doping of LiNi₀̣₅Mn₁̣₅O₄ spinel
Galaxy Selection and Clustering and Lyman alpha Absorber Identification
The effects of galaxy selection on our ability to constrain the nature of
weak Ly\alpha absorbers at low redshift are explored. Current observations
indicate the existence of a population of gas-rich, low surface brightness
(LSB) galaxies, and these galaxies may have large cross sections for Ly\alpha
absorption. Absorption arising in LSB galaxies may be attributed to HSB
galaxies at larger impact parameters from quasar lines of sight, so that the
observed absorption cross sections of galaxies may seem unreasonably large.
Thus it is not possible to rule out scenarios where LSB galaxies make
substantial contributions to Ly\alpha absorption using direct observations.
Less direct tests, where observational selection effects are taken into account
using simulations, should make it possible to determine the nature of Ly\alpha
absorbers by observing a sample of ~100 galaxies around quasar lines of sight
with well-defined selection criteria. Such tests, which involve comparing
simulated and observed plots of the unidentified absorber fractions and
absorbing galaxy fractions versus impact parameter, can distinguish between
scenarios where absorbers arise in particular galaxies and those where
absorbers arise in gas tracing the large scale galaxy distribution. Care must
be taken to minimize selection effects even when using these tests. Results
from such tests are likely to depend upon the limiting neutral hydrogen column
density. While not enough data are currently available to make a strong
conclusion about the nature of moderately weak absorbers, evidence is seen that
such absorbers arise in gas that is around or between galaxies that are often
not detected in surveys.Comment: 15 pages, 10 figures, accepted to the Astrophysical Journa
Quasar Proper Motions and Low-Frequency Gravitational Waves
We report observational upper limits on the mass-energy of the cosmological
gravitational-wave background, from limits on proper motions of quasars.
Gravitational waves with periods longer than the time span of observations
produce a simple pattern of apparent proper motions over the sky, composed
primarily of second-order transverse vector spherical harmonics. A fit of such
harmonics to measured motions yields a 95%-confidence limit on the mass-energy
of gravitational waves with frequencies <2e-9 Hz, of <0.11/h*h times the
closure density of the universe.Comment: 15 pages, 1 figure. Also available at
http://charm.physics.ucsb.edu:80/people/cgwinn/cgwinn_group/index.htm
Effect of in-plane magnetic field on the photoluminescence spectrum of modulation-doped quantum wells and heterojunctions
The photoluminescence (PL) spectrum of modulation-doped GaAs/AlGaAs quantum
wells (MDQW) and heterojunctions (HJ) is studied under a magnetic field
() applied parallel to the two-dimensional electron gas (2DEG) layer.
The effect of strongly depends on the electron-hole separation
(), and we revealed remarkable -induced modifications of the PL
spectra in both types of heterostructures. A model considering the direct
optical transitions between the conduction and valence subband that are shifted
in k-space under , accounts qualitatively for the observed spectral
modifications. In the HJs, the PL intensity of the bulk excitons is strongly
reduced relatively to that of the 2DEG with increasing . This means
that the distance between the photoholes and the 2DEG decreases with increased
, and that free holes are responsible for the hole-2DEG PL.Comment: 6pages, 5figure
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