7,412 research outputs found
Non-adherence to eye care in people with diabetes
Objective Evaluate individual factors that impact adherence to eye care follow-up in patients with diabetes. Design and methods A 4-year retrospective chart review was conducted for 1968 patients with diabetes over age 40 from an urban academic center. Data collected included demographics, insurance, visual acuity, smoking status, medications, dates of dilated fundus examinations (DFE), and reported hemoglobin A1C and blood glucose levels. The primary outcome was timely DFE follow-up adherence following the initial eye exam visit. Results Overall, 41.6% of patients adhered to initial follow-up eye care recommendations. Multivariable analysis demonstrated that patients with severe diabetic retinopathy (DR) were more adherent than patients with mild DR (OR 1.86). Other variables associated with increased adherence were visual impairment and reported A1C or blood glucose. Smoking was associated with decreased adherence. Ethnicity and insurance were also significantly associated with adherence. Longitudinal follow-up rates were influenced by additional factors, including ethnicity and neighborhood deprivation index. Conclusions Patients with moderate to severe DR and/ or visual impairment were more likely to adhere to timely DFE follow-up. This could relate to the presence of visual symptoms and/or other systemic manifestations of diabetes. Smokers were less likely to adhere to timely DFE follow-up. One hypothesis is patients who smoke have other symptomatic health problems which patients prioritize over asymptomatic ocular disorders. In order to reduce vision loss from DR, practitioners should be aware that patients with mild and moderate DR, patients with normal vision, and smokers are at greater risk for poor follow-up eye care adherence. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved
Cellular Models of Aggregation-Dependent Template-Directed Proteolysis to Characterize Tau Aggregation Inhibitors for Treatment of Alzheimer's Disease
Copyright © 2015, The American Society for Biochemistry and Molecular Biology. Acknowledgements-We thank Drs Timo Rager and Rolf Hilfiker (Solvias, Switzerland) for polymorph analyses.Peer reviewedPublisher PD
A New Look At Carbon Abundances In Planetary Nebulae. III. DDDM1, IC 3568, IC4593, NGC 6210, NGC 6720, NGC 6826, & NGC 7009
This paper is the third in a series reporting on a study of carbon abundances
in a carefully chosen sample of planetary nebulae representing a large range in
progenitor mass and metallicity. We make use of the IUE Final Archive database
containing consistently-reduced spectra to measure line strengths of C III]
1909 along with numerous other UV lines for the planetary nebulae DDDM1, IC
3568, IC 4593, NGC 6210, NGC 6720, NGC 6826, & NGC 7009. We combine the IUE
data with line strengths from optical spectra obtained specifically to match
the IUE slit positions as closely as possible, to determine values for the
abundance ratios He/H, O/H, C/O, N/O, and Ne/O. The ratio of C III] 1909/C II
4267 is found to be effective for merging UV and optical spectra when He II
1640/4686 is unavailable. Our abundance determination method includes a 5-level
program whose results are fine-tuned by corrections derived from detailed
photoionization models constrained by the same set of emission lines. All
objects appear to have subsolar levels of O/H, and all but one show N/O levels
above solar. In addition, the seven planetary nebulae span a broad range in C/O
values. We infer that many of our objects are matter bounded, and thus the
standard ionization correction factor for N/O may be inappropriate for these
PNe. Finally, we estimate C/O using both collisionally-excited and
recombination lines associated with C+2 and find the well established result
that abundances from recombination lines usually exceed those from
collisionally-excited lines by several times.Comment: 36 pages, 7 tables, 2 figures, latex. Tables and figures supplied as
two separate postscript files. Accepted for publication in Ap
K-band Spectroscopy of Clusters in NGC 4038/4039
Integral field spectroscopy in the K-band (1.9-2.4um) was performed on four
IR-bright star clusters and the two nuclei in NGC 4038/4039 (``The Antennae'').
Two of the clusters are located in the overlap region of the two galaxies, and
together comprise ~25% of the total 15um and ~10% of the total 4.8 GHz emission
from this pair of merging galaxies. The other two clusters, each of them
spatially resolved into two components, are located in the northern galaxy, one
in the western and one in the eastern loop of blue clusters. Comparing our
analysis of Brgamma, CO band-heads, He I (2.058um), Halpha (from archival HST
data), and V-K colors with stellar population synthesis models indicates that
the clusters are extincted (A_V ~ 0.7 - 4.3 mags) and young, displaying a
significant age spread (4-13 Myrs). The starbursts in the nuclei are much older
(65 Myrs), with the nucleus of NGC 4038 displaying a region of recent star
formation northward of its K-band peak. Using our derived age estimates and
assuming the parameters of the IMF (Salpeter slope, upper mass cut-off of 100
M_sun, Miller-Scalo between 1 M_sun and 0.1 M_sun), we find that the clusters
have masses between 0.5 and 5 * 10^6M_sun.Comment: 10 pages, 3 figures, ApJ accepte
Global metabolite analysis of the land snail Theba pisana hemolymph during active and aestivated states
The state of metabolic dormancy has fascinated people for hundreds of years, leading to research exploring the identity of natural molecular components that may induce and maintain this state. Many animals lower their metabolism in response to high temperatures and/or arid conditions, a phenomenon called aestivation. The biological significance for this is clear; by strongly suppressing metabolic rate to low levels, animals minimize their exposure to stressful conditions. Understanding blood or hemolymph metabolite changes that occur between active and aestivated animals can provide valuable insights relating to those molecular components that regulate hypometabolism in animals, and how they afford adaptation to their different environmental conditions. In this study, we have investigated the hemolymph metabolite composition from the land snail Theba pisana, a remarkably resilient mollusc that displays an annual aestivation period. Using LC-MS-based metabolomics analysis, we have identified those hemolymph metabolites that show significant changes in relative abundance between active and aestivated states. We show that certain metabolites, including some phospholipids [e.g. LysoPC(14:0)], and amino acids such as l-arginine and l-tyrosine, are present at high levels within aestivated snails. Further investigation of our T. pisana RNA-sequencing data elucidated the entire repertoire of phospholipid-synthesis genes in the snail digestive gland, as a precursor towards future comparative investigation between the genetic components of aestivating and non-aestivating species. In summary, we have identified a large number of metabolites that are elevated in the hemolymph of aestivating snails, supporting their role in protecting against heat or desiccation
Wolf-Rayet Galaxies in the Sloan Digital Sky Survey: the metallicity dependence of the initial mass function
We use a large sample of 174 Wolf-Rayet (WR) galaxies drawn from the Sloan
Digital Sky Survey to study whether and how the slope of the stellar initial
mass function depends on metallicity. We calculate for each object its oxygen
abundance according to which we divide our sample into four metallicity
subsamples. For each subsample, we then measure three quantities: the
equivalent width of \hb emission line, the equivalent width of WR bump around
4650\AA, and the WR bump-to-\hb intensity ratio, and compare to the predictions
of the same quantities by evolutionary synthesis models of Schaerer & Vacca.
Such comparisons lead to a clear dependence of the slope of initial mass
function () on metallicity in that galaxies at higher metallicities
tend to have steeper initial mass functions, with the slope index ranging from
1.00 for the lowest metallicity of to 3.30
for the highest metallicity . We have carefully examined the possible
sources of systematic error either in models or in our observational
measurements and shown that these sources do not change this result.Comment: 12 pages, 6 figures, ApJ accepte
Thinking about growth : a cognitive mapping approach to understanding small business development
School of Managemen
Spitzer IRS Observations of the Galactic Center: Shocked Gas in the Radio Arc Bubble
We present Spitzer IRS spectra (R ~600, 10 - 38 micron) of 38 positions in
the Galactic Center (GC), all at the same Galactic longitude and spanning
plus/minus 0.3 degrees in latitude. Our positions include the Arches Cluster,
the Arched Filaments, regions near the Quintuplet Cluster, the ``Bubble'' lying
along the same line-of-sight as the molecular cloud G0.11-0.11, and the diffuse
interstellar gas along the line-of-sight at higher Galactic latitudes. From
measurements of the [O IV], [Ne II], [Ne III], [Si II], [S III], [S IV], [Fe
II], [Fe III], and H_2 S(0), S(1), and S(2) lines we determine the gas
excitation and ionic abundance ratios. The Ne/H and S/H abundance ratios are ~
1.6 times that of the Orion Nebula. The main source of excitation is
photoionization, with the Arches Cluster ionizing the Arched Filaments and the
Quintuplet Cluster ionizing the gas nearby and at lower Galactic latitudes
including the far side of the Bubble. In addition, strong shocks ionize gas to
O^{+3} and destroy dust grains, releasing iron into the gas phase (Fe/H ~ 1.3
times 10^{-6} in the Arched Filaments and Fe/H ~ 8.8 times 10^{-6} in the
Bubble). The shock effects are particularly noticeable in the center of the
Bubble, but O is present in all positions. We suggest that the shocks
are due to the winds from the Quintuplet Cluster Wolf-Rayet stars. On the other
hand, the H_2 line ratios can be explained with multi-component models of warm
molecular gas in photodissociation regions without the need for H_2 production
in shocks.Comment: 51 pages, 17 figures To be published in the Astrophysical Journa
Meteorologic parameters analysis above Dome C made with ECMWF data
In this paper we present the characterization of all the principal
meteorological parameters (wind speed and direction, pressure, absolute and
potential temperature) extended over 25 km from the ground and over two years
(2003 and 2004) above the Antarctic site of Dome C. The data set is composed by
'analyses' provided by the General Circulation Model (GCM) of the European
Center for Medium Weather Forecasts (ECMWF) and they are part of the catalog
MARS. A monthly and seasonal (summer and winter time) statistical analysis of
the results is presented. The Richardson number is calculated for each month of
the year over 25 km to study the stability/instability of the atmosphere. This
permits us to trace a map indicating where and when the optical turbulence has
the highest probability to be triggered on the whole troposphere, tropopause
and stratosphere. We finally try to predict the best expected isoplanatic angle
and wavefront coherence time employing the Richardson number maps, the wind
speed profiles and simple analytical models of CN2 vertical profiles.Comment: 28 pages, 14 figures, pdf file, to be published on July 2006 - PASP,
see also http://www.arcetri.astro.it/~masciad
- âŠ