UCD Candidates in the Hydra Cluster

NGC 3311, the giant cD galaxy in the Hydra cluster (A1060), has one of the largest globular cluster systems known. We describe new Gemini GMOS (g',i') photometry of the NGC 3311 field which reveals that the red, metal-rich side of its globular cluster population extends smoothly upward into the mass range associated with the new class of Ultra-Compact Dwarfs (UCDs). We identify 29 UCD candidates with estimated masses > 6x10^6 solar masses and discuss their characteristics. This UCD-like sequence is the most well defined one yet seen, and reinforces current ideas that the high-mass end of the globular cluster sequence merges continuously into the UCD sequence, which connects in turn to the E galaxy structural sequence.Comment: 5 pages, 3 figures. Accepted for publication in ApJ Letter

From Supermassive Black Holes to Dwarf Elliptical Nuclei: a Mass Continuum

Considerable evidence suggests that supermassive black holes reside at the centers of massive galactic bulges. At a lower galactic mass range, many dwarf galaxies contain extremely compact nuclei that structurally resemble massive globular clusters. We show that both these types of central massive objects (CMO's) define a single unbroken relation between CMO mass and the luminosity of their host galaxy spheroid. Equivalently, M_CMO is directly proportional to the host spheroid mass over 4 orders of magnitude. We note that this result has been simultaneously and independently identified by Cote et al. (2006), see also Ferrarese et al. (2006). We therefore suggest that the dE,N nuclei may be the low-mass analogs of supermassive black holes, and that these two types of CMO's may have both developed starting from similar initial formation processes. The overlap mass interval between the two types of CMO's is small, and suggests that for M_CMO > 10^7 M_sun, the formation of a black hole was strongly favored, perhaps because the initial gas infall to the center was too rapid and violent for star formation to occur efficiently.Comment: 4 pages, 2 figures, submitted to ApJ

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

Zooplankton and Micronekton in Cyclones and Anticyclones in the Northeast Gulf of Mexico

Two cruises were made to the northeast Gulf of Mexico in October 1996 and August 1997. The main objectives of the cruises were to survey cetacean and seabird populations and describe their hydrographic and biological environments. An additional objective was to characterize cetacean and seabird habitats in terms of food resources. During both cruises a cyclone and an anticyclone were sampled as well as the confluence region between them. Zooplankton and micronekton were sampled both directly with nets and indirectly with a 153-kHz acoustic Doppler current profiler. Within cruises, zooplankton and micronekton biomass was higher in cyclones than in anticyclones. Biomass within the confluence was either highest or intermediate for both cruises. Between cruises, within features, August 1997 biomass was significantly higher than October 1996 biomass

The experience of accommodating privacy restrictions during implementation of a large-scale surveillance study of an osteoporosis medication.

PurposeTo explore whether privacy restrictions developed to protect patients have complicated research within a 15-year surveillance study conducted with US cancer registries.MethodsData from enrolling 27 cancer registries over a 10-year period were examined to describe the amount of time needed to obtain study approval. We also analyzed the proportion of patients that completed a research interview out of the total reported by the registries and examined factors thought to influence this measure.ResultsThe average length of the research review process from submission to approval of the research was 7 months (range, <1 to 24 months), and it took 6 months or more to obtain approval of the research at 41% of the cancer registries. Most registries (78%) required additional permission steps to gain access to patients for research. After adjustment for covariates, the interview response proportion was 110% greater (ratio of response proportion = 2.1; 95% confidence interval: 1.3, 3.3) when the least restrictive versus the most restrictive permission steps were required. An interview was more often completed for patients (or proxies) if patients were alive, within a year of being diagnosed, or identified earlier in the study.ConclusionsLengthy research review processes increased the time between diagnosis and provision of patient information to the researcher. Requiring physician permission for access to patients was associated with lower subject participation. A single national point of entry for use of cancer registry data in health research is worthy of consideration to make the research approval process efficient. © 2016 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd

Prion protein repeat expansion results in increased aggregation and reveals phenotypic variability

Mammalian prion diseases are fatal neurodegenerative disorders dependent on the prion protein PrP. Expansion of the oligopeptide repeats (ORE) found in PrP is associated with inherited prion diseases. Patients with ORE frequently harbor PrP aggregates, but other factors may contribute to pathology, as they often present with unexplained phenotypic variability. We created chimeric yeast-mammalian prion proteins to examine the influence of the PrP ORE on prion properties in yeast. Remarkably, all chimeric proteins maintained prion characteristics. The largest repeat expansion chimera displayed a higher propensity to maintain a self-propagating aggregated state. Strikingly, the repeat expansion conferred increased conformational flexibility, as observed by enhanced phenotypic variation. Furthermore, the repeat expansion chimera displayed an increased rate of prion conversion, but only in the presence of another aggregate, the [RNQ(+)] prion. We suggest that the PrP ORE increases the conformational flexibility of the prion protein, thereby enhancing the formation of multiple distinct aggregate structures and allowing more frequent prion conversion. Both of these characteristics may contribute to the phenotypic variability associated with PrP repeat expansion diseases

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

Enhancing evidence-based diabetes and chronic disease control among local health departments: A multi-phase dissemination study with a stepped-wedge cluster randomized trial component

Examples of Intervention Dissemination Strategies and Description. (DOCX 22 kb

Technical Reviewing for the Family First Prevention Services Act: Strategies and Recommendations

The Family First Prevention Services Act (FFPSA) has compelled states to expand their priorities to implement evidence-based practices (EBPs) as a means to prevent foster care placement. While the states may opt to include EBPs already approved by the Administration for Children and Families (ACF), some state leaders are opting to commission an independent technical review for the EBP they would prefer to implement as part of their FFPSA plan. While the goal is for ACF to approve their plan and issue a temporary license, little guidance is provided on how to conduct technical reviews. Relying upon the expectations that ACF has outlined for each state, we illustrate the process for conducting reviews of SafeCare in Iowa and Utah and of Family-Centered Treatment in Arkansas. Despite FFPSA and ACF guidance, rendering an evidence rating was difficult given the variability in how some studies measured baseline equivalence, lack of robust testing methods, and conflicting findings across studies. We conclude with recommendations on addressing these challenges and strategies for conducting high-quality technical reviews. The review process offers an opportunity to synthesize a large body of research to inform child welfare practice