Globular Clusters in the dE,N galaxy NGC 3115 DW1: New Insights from Spectroscopy and HST Photometry

The properties of globular clusters in dwarf galaxies are key to understanding the formation of globular cluster systems, and in particular in verifying scenarios in which globular cluster systems of larger galaxies formed (at least partly) from the accretion of dwarf galaxies. Here, we revisit the globular cluster system of the dE,N galaxy NGC 3115 DW1 - a companion of the nearby S0 galaxy NGC 3115 - adding Keck/LRIS spectroscopy and HST/WFPC2 imaging to previous ground-based photometry. Spectra for seven globular clusters reveal normal abundance ratios with respect to the Milky Way and M31 clusters, as well as a relatively high mean metallicity ([Fe/H] = -1.0+/-0.1 dex). Crude kinematics indicate a high velocity dispersion within 10 kpc which could either be caused by dark matter dominated outer regions, or by the stripping of outer globular clusters by the nearby giant galaxy NGC 3115. The total galaxy mass out to 3 and 10 kpc lies between 10^10 and 10^11 solar masses and 2*10^10 and 4*10^11 solar masses, respectively, depending on the mass estimator used and the assumptions on cluster orbits and systemic velocity. The HST imaging allows measurement of sizes for two clusters, returning core radii around 2.0 pc, similar to the sizes observed in other galaxies. Spectroscopy allows an estimate of the degree of contamination by foreground stars or background galaxies for the previous ground-based photometry, but does not require a revision of previous results: NGC 3115 DW1 hosts around 60+/-20 clusters which corresponds to a specific frequency of 4.9+/-1.9, on the high end for massive dEs. Given its absolute magnitude (M_V=-17.7 mag) and the properties of its cluster system, NGC 3115 DW1 appears to be a transition between a luminous dE and low-luminosity E galaxy.Comment: 25 pages, 8 figures, accepted for publication in The Astronomical Journal, August 2000 issu

An updated survey of globular clusters in M 31. III. A spectroscopic metallicity scale for the Revised Bologna Catalog

We present a new homogeneous set of metallicity estimates based on Lick indices for 245 old globular clusters of the M31 galaxy comprised in the Revised Bologna Catalog. The metallicity distribution of the M31 globular clusters is briefly discussed and compared with that of the Milky Way. Simple parametric statistics suggests that the [Fe/H] distribution is likely not unimodal. The strong correlation between metallicity and kinematics found in previous studies is confirmed. The most metal-rich GCs tend to be packed at the center of the system and share the galactic rotation as traced by the HI disk. Although the velocity dispersion around the curve increases with decreasing metallicity, also clusters with [Fe/H]<-1.0 display a clear rotational pattern, at odds with their Milky Way counterparts.Comment: 25 pages with 17 figures and 2 Appendices - To appear on Astronomy & Astrophysic

Evolutionary biology for the 21st century

New theoretical and conceptual frameworks are required for evolutionary biology to capitalize on the wealth of data now becoming available from the study of genomes, phenotypes, and organisms - including humans - in their natural environments.Molecular and Cellular BiologyOrganismic and Evolutionary Biolog

An updated survey of globular clusters in M31. II Newly discovered bright and remote clusters

We present the first results of a large spectroscopic survey of candidate globular clusters located in the extreme outskirts of the nearby M31 galaxy. We obtained low resolution spectra of 48 targets selected from the XSC of 2MASS, as in Galleti et al. (2005). The observed candidates have been robustly classified according to their radial velocity and by verifying their extended/point-source nature from ground-based optical images. Among the 48 observed candidates clusters we found 5 genuine remote globular clusters. One of them has been already identified independently by Mackey et al. (2007), their GC1; the other four are completely new discoveries: B516, B517, B518, B519. The newly discovered clusters lie at projected distance 40 kpc<~R_p<~100 kpc from the center of M31, and have absolute integrated magnitude -9.5<M_V<-7.5. For all the observed clusters we have measured the strongest Lick indices and we have obtained spectroscopic metallicity estimates. Mackey-GC1, Martin-GC1, B517 and B518 have spectra typical of old and metal poor globular clusters ([Fe/H]<~ -1.3); B519 appears old but quite metal-rich ([Fe/H]~-0.5); B516 presents very strong Balmer absorption lines: if this is indeed a cluster it should have a relatively young age (likely <2 Gyr). The present analysis nearly doubles the number of M31 globulars at R_p> 40 kpc. At odds with the Milky Way, M31 appears to have a significant population of very bright globular clusters in its extreme outskirts.Comment: 16 pages including 6 pages published only in the electronic edition of the Journal. Accepted for publication in A&

715-2 A Prospective, Randomized Trial Evaluating the Prophylactic Use of Balloon Pumping in High Risk Myocardial Infarction Patients: PAMI-2

Myocardial infarction (MI) patients with advanced age, multivessel disease or ventricular dysfunction continue to have a poor prognosis despite reperfusion therapy. Furthermore, the majority of deaths from MI occur within the first 48 hours, thus risk stratification and therapeutic interventions ideally should occur acutely. The PAMI-2 study has prospectively evaluated the hypotheses that 1) emergency catheterization with primary PTCA may allow acute risk stratification and 2) clinical outcome, ventricular function and infarct vessel patency will be improved by balloon pumping in patients identified to be high risk. MI patients who presented 0–12 hrs underwent emergency catheterization and PTCA and were stratified as high risk if one of the following was present: age&gt;70 yrs, vein graft occlusion, 3 vessel disease, ejection fraction &lt;45%, suboptimal PTCA result or if malignant arrhythmias persisted post PTCA. High risk patients were randomized to receive or not receive an intra aortic balloon pump (IABP) for 48 hrs. Catheterization was repeated at day 7 to determine infarct vessel patency and improvement in ventricular function. At 6 weeks a rest and exercise radionuclide ventriculogram was performed. To date, 320 patients have been enrolled, 175 of which have complete data available for analysis. The reasons for high risk status include: advanced age 38%, poor LV function 55%, 3 vessel disease 37%, vein graft occlusion 6%, suboptimal PTCA 9%, and arrhythmias 5%. Despite the high risk status, in-hospital outcomes have been favorable: death 2.9%, recurrent MI 5.8%, stroke 1.2%, angiographic reocclusion 5.8%, heart failure 19.1% and combined events 26.6%. Thus “high risk” patients treated with primary PTCA±balloon pumping appear to have a good prognosis. Whether the improved outcome is due to balloon pump support or simply due to aggressive mechanical revascularization will be determined in the entire cohort by March 1995

Lactobacillus casei Abundance Is Associated with Profound Shifts in the Infant Gut Microbiome

Colonization of the infant gut by microorganisms over the first year of life is crucial for development of a balanced immune response. Early alterations in the gastrointestinal microbiota of neonates has been linked with subsequent development of asthma and atopy in older children. Here we describe high-resolution culture-independent analysis of stool samples from 6-month old infants fed daily supplements of Lactobacillus casei subsp. Rhamnosus (LGG) or placebo in a double-blind, randomized Trial of Infant Probiotic Supplementation (TIPS). Bacterial community composition was examined using a high-density microarray, the 16S rRNA PhyloChip, and the microbial assemblages of infants with either high or low LGG abundance were compared. Communities with high abundance of LGG exhibited promotion of phylogenetically clustered taxa including a number of other known probiotic species, and were significantly more even in their distribution of community members. Ecologically, these aspects are characteristic of communities that are more resistant to perturbation and outgrowth of pathogens. PhyloChip analysis also permitted identification of taxa negatively correlated with LGG abundance that have previously been associated with atopy, as well as those positively correlated that may prove useful alternative targets for investigation as alternative probiotic species. From these findings we hypothesize that a key mechanism for the protective effect of LGG supplementation on subsequent development of allergic disease is through promotion of a stable, even, and functionally redundant infant gastrointestinal community

Noncommutative geometry, Quantum effects and DBI-scaling in the collapse of D0-D2 bound states

We study fluctuations of time-dependent fuzzy two-sphere solutions of the non-abelian DBI action of D0-branes, describing a bound state of a spherical D2-brane with N D0-branes. The quadratic action for small fluctuations is shown to be identical to that obtained from the dual abelian D2-brane DBI action, using the non-commutative geometry of the fuzzy two-sphere. For some of the fields, the linearized equations take the form of solvable Lam\'e equations. We define a large-N DBI-scaling limit, with vanishing string coupling and string length, and where the gauge theory coupling remains finite. In this limit, the non-linearities of the DBI action survive in both the classical and the quantum context, while massive open string modes and closed strings decouple. We describe a critical radius where strong gauge coupling effects become important. The size of the bound quantum ground state of multiple D0-branes makes an intriguing appearance as the radius of the fuzzy sphere, where the maximal angular momentum quanta become strongly coupled.Comment: 34 pages, Latex; v2: Minor correction in conformal transformation of couplings, references adde

Treating nontuberculous mycobacteria in children with cystic fibrosis: a multicentre retrospective study

BackgroundRespiratory infection with nontuberculous mycobacteria (NTM) in children with cystic fibrosis (CF) has increased in prevalence. The condition is difficult to diagnose and treatments are complex with limited evidence to guide practice. This study describes the approaches to diagnosis, management and consequences of treatment in a multicentre cohort of children with CF in the UK.MethodsRetrospective data were collected from 11 CF specialist centres from patients less than 17 years old, treated for NTM infection between 2006 and 2017. Descriptive statistics were used to describe the clinical characteristics of children treated. Treatment regimens, adverse events and success of treatment, with respect to lung function and culture conversion, were evaluated.ResultsData from 70 patients treated for NTM pulmonary disease were collated (60 Mycobacterium abscessus complex (MABSC); 10 M. avium complex (MAC)). Older age and previous diagnosis of allergic bronchopulmonary aspergillosis were all significantly associated with NTM. There was a wide variance in drug choice and side effects were reported with all agents. NTM eradication occurred in 80% of patients with MAC and 48% with MABSC, with variable outcomes on lung function.ConclusionsDiagnosis and treatment of NTM infection in children with CF is challenging. Treatment success is not guaranteed, particularly for MABSC. Large clinical trials are urgently required to evaluate treatment regimes and their suitability and efficacy in children.</jats:sec