4,955 research outputs found
OBCS: The Ontology of Biological and Clinical Statistics
Statistics play a critical role in biological and clinical research. To promote logically consistent representation and classification of statistical entities, we have developed the Ontology of Biological and Clinical Statistics (OBCS). OBCS extends the Ontology of Biomedical Investigations (OBI), an OBO Foundry ontology supported by some 20 communities. Currently, OBCS contains 686 terms, including 381 classes imported from OBI and 147 classes specific to OBCS. The goal of this paper is to present OBCS for community critique and to describe a number of use cases designed to illustrate its potential applications. The OBCS project and source code are available at http://obcs.googlecode.com
Further Definition of the Mass-Metallicity Relation in Globular Cluster Systems Around Brightest Cluster Galaxies
We combine the globular cluster data for fifteen Brightest Cluster Galaxies
and use this material to trace the mass-metallicity relations (MMR) in their
globular cluster systems (GCSs). This work extends previous studies which
correlate the properties of the MMR with those of the host galaxy. Our combined
data sets show a mean trend for the metal-poor (MP) subpopulation which
corresponds to a scaling of heavy-element abundance with cluster mass Z ~
M^(0.30+/-0.05). No trend is seen for the metal-rich (MR) subpopulation which
has a scaling relation that is consistent with zero. We also find that the
scaling exponent is independent of the GCS specific frequency and host galaxy
luminosity, except perhaps for dwarf galaxies.
We present new photometry in (g',i') obtained with Gemini/GMOS for the
globular cluster populations around the southern giant ellipticals NGC 5193 and
IC 4329. Both galaxies have rich cluster populations which show up as normal,
bimodal sequences in the colour-magnitude diagram.
We test the observed MMRs and argue that they are statistically real, and not
an artifact caused by the method we used. We also argue against asymmetric
contamination causing the observed MMR as our mean results are no different
from other contamination-free studies. Finally, we compare our method to the
standard bimodal fitting method (KMM or RMIX) and find our results are
consistent.
Interpretation of these results is consistent with recent models for globular
cluster formation in which the MMR is determined by GC self-enrichment during
their brief formation period.Comment: 35 pages, 20 figures. Accepted by Astronomical Journal. Complete
preprint including high resolution figures available at
http://www.physics.mcmaster.ca/~cockcroft/MMRpape
Sociocultural Influences on Diabetes Self-Management Behaviors in Older African Americans
Objective. The purpose of this observational study was to describe the associations between cultural beliefs that are prevalent in older African Americans and adherence to diabetes self-management (DSM) behaviors.
Methods. In a community population of 110 older African Americans with type 2 diabetes, the investigators administered surveys that assess present time orientation (PTO), future time orientation (FTO), and religiosity, as well as exercising habits, reading food labels, and checking blood glucose.
Results. Participants who reported regularly exercising had significantly lower PTO scores and higher FTO and religiosity scores than participants who did not regularly exercise. Similarly, participants who reported reading food labels had lower PTO scores and higher FTO scores but did not differ in religiosity. Participants who reported checking blood glucose levels tended to have higher FTO scores but did not differ in PTO or religiosity. Participants who engaged in all three diabetes self-management behaviors had significantly lower PTO scores and higher FTO and religiosity scores.
Conclusion. These data indicate that cultural diversity within older African Americans may influence DSM behaviors and contribute to disparities in diabetes outcomes in this high-risk population. Efforts to prevent complications of diabetes might benefit from consideration of these cultural factors
Cultural diversity and views on Alzheimer disease in older African Americans.
Cultural constructs prevalent in older African Americans may influence their risk perceptions and knowledge of Alzheimer disease (AD). To examine this issue, we administered 3 sociocultural scales, the AD Knowledge Scale, and a Risk Perception questionnaire to 271 older African Americans who were recruited from a large community senior center and local churches. Higher Present Time Orientation was significantly related to perceptions of having little control over risks to health (P=0.004), God\u27s Will in determining AD (P=0.001), and lower AD knowledge (
Learning From Experience : An Impact Assessment Of Work By The Bernard van Leer foundation in Kenya, Colombia, Germany and Poland.
The Foundation funded an independent evaluation to examine the impact that it had made in young children's lives in four countries: Kenya, Colombia, Poland and Germany. A five-person evaluation team conducted an in-depth examination of work funded by 92 million in investments over the course of 40 years. This report shares the findings
The Globular Cluster Systems around NGC 3311 and NGC 3309
We present extensive new photometry in (g',i') of the large globular cluster
(GC) system around NGC 3311, the central cD galaxy in the Hydra cluster. Our
GMOS data cover a 5.5' field of view and reach a limiting magnitude i' = 26,
about 0.5 magnitude fainter than the turnover point of the GC luminosity
function. We find that NGC 3311 has a huge population of ~16, 000 GCs, closely
similar to the prototypical high specific frequency Virgo giant M87. The
color-magnitude distribution shows that the metal-poor blue GC sequence and the
metal-richer red sequence are both present, with nearly equal numbers of
clusters. Bimodal fits to the color distributions confirm that the blue
sequence shows the same trend of progressively increasing metallicity with GC
mass that has previously been found in many other large galaxies; the
correlation we find corresponds to a scaling of GC metallicity with mass of Z ~
M^0.6 . By contrast, the red sequence shows no change of mean metallicity with
mass, but it shows an upward extension to much higher than normal luminosity
into the UCD-like range, strengthening the potential connections between
massive GCs and UCDs. The GC luminosity function, which we measure down to the
turnover point at M_I = -8.4, also has a normal form like those in other giant
ellipticals. Within the Hydra field, another giant elliptical NGC 3309 is
sitting just 100" from the cD NGC 3311. We use our data to solve simultaneously
for the spatial structure and total GC populations of both galaxies at once.
Their specific frequencies are S_N (NGC 3311) = 12.5 +/- 1.5 and S_N (NGC 3309)
= 0.6 +/-0.4. NGC 3311 is completely dominant and entirely comparable with
other cD-type systems such as M87 in Virgo.Comment: 15 pages, 15 figures. Accepted to the Astrophysical Journal. Version
with higher resolution figures is available at
http://www.thewehners.net/astro/papers/wehner_n3311_highres.pd
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