Searches for Extremely Metal Poor Galaxies using ALFALFA-selected Dwarf Galaxies

We present a study of nearby dwarf galaxies selected from the ALFALFA blind HI survey. A primary goal of the project was to utilize a non-standard selection method with the hope of detecting previously unrecognized extremely metal-poor (XMP) galaxies. The study was motivated by the recent discovery of two XMP galaxies $-$ Leo P and Leoncino $-$ which were both originally found via the ALFALFA survey. We have obtained narrowband H$\alpha$ images for 42 dwarf systems, many of which are located in the local void in front of the Pisces-Perseus Supercluster. Spectra for eleven of the best candidates resulted in the determination of metal abundances for ten of the systems. None were found to be extremely metal poor, although one system (AGC 123350) was found to have an oxygen abundance of log(O/H)+12 = 7.46, or $\sim$6\% solar. One of the galaxies in our sample exhibits a high oxygen abundance for its luminosity, suggesting the possibility that it may have a tidal origin.Comment: 21 pages, 11 figures, 4 table

The Directed Dominating Set Problem: Generalized Leaf Removal and Belief Propagation

A minimum dominating set for a digraph (directed graph) is a smallest set of vertices such that each vertex either belongs to this set or has at least one parent vertex in this set. We solve this hard combinatorial optimization problem approximately by a local algorithm of generalized leaf removal and by a message-passing algorithm of belief propagation. These algorithms can construct near-optimal dominating sets or even exact minimum dominating sets for random digraphs and also for real-world digraph instances. We further develop a core percolation theory and a replica-symmetric spin glass theory for this problem. Our algorithmic and theoretical results may facilitate applications of dominating sets to various network problems involving directed interactions.Comment: 11 pages, 3 figures in EPS forma

Gravitational Lensing by Nearby Clusters of Galaxies

We present an estimation of the expected number of arcs and arclets in a sample of nearby (z<0.1) clusters of galaxies, that takes into account the magnitude limit of the objects as well as seeing effects. We show that strong lensing effects are not common, but also they are not as rare as usually stated. Indeed, for a given cluster, they present a strong dependence with the magnitude limit adopted in the analysis and the seeing of the observations. We also describe the procedures and results of a search for lensing effects in a sample of 33 clusters spanning the redshift range of 0.014 to 0.076, representative of the local cluster distribution. This search produced two arc candidates. The first one is in A3408 (z=0.042), the same arc previously discovered by Campusano & Hardy (1996), with z=0.073 and associated to the brightest cluster galaxy. The second candidate is in the cluster A3266 (z=0.059) and is near a bright elliptical outside the cluster center, requiring the presence of a very massive sub-structure around this galaxy to be produced by gravitational lensing.Comment: 22 pages including 9 Figures and 2 Tables, submitted to A

Zum biochemischen Wirkungsmechanismus des adrenocorticotropen Hormons

Es wird eine Übersicht über zwei Hypothesen und die dazugehörigen Befunde zum Wirkungsmechanismus des adrenocorticotropen Hormons gegeben: 1. Der Gehalt der Nebenniere an cyclischem Adenosinmonophosphat wird durch ACTH erhöht, die stimulierende Wirkung des Hormons auf die Corticoidsynthese wird durch cyclisches Adenosinmonophosphat imitiert. Die Beschleunigung der Corticoidsynthese dürfte allerdings nicht durch eine Aktivierung der Phosphorylase in der Nebenniere erfolgen. 2. Befunde zum biochemischen Mechanismus der Stimulation der Proteinsynthese in der Nebenniere durch ACTH werden referiert. Die Intaktheit der Proteinsynthese der Nebenniere scheint für den steroidogenen Effekt des ACTH Voraussetzung zu sein.Two current hypotheses on the mechanism of action of ACTH are reviewed: 1. The content of cyclic 3,5-adenosine monophosphate of the adrenals is increased by ACTH, and cyclic AMP or ACTH enhance corticoid synthesis. However, stimulation of corticoid synthesis presumably is not mediated by activation of adrenal phosphorylase. 2. Experiments dealing with the biochemical mechanism of the stimulation of adrenal protein synthesis are reviewed. The integrity of the adrenal protein synthesis appears to be necessary for the enhancement of corticoid synthesis by ACTH

Systematic review of safety checklists for use by medical care teams in acute hospital settings - limited evidence of effectiveness

<p>Abstract</p> <p>Background</p> <p>Patient safety is a fundamental component of good quality health care. Checklists have been proposed as a method of improving patient safety. This systematic review, asked "In acute hospital settings, would the use of safety checklists applied by medical care teams, compared to not using checklists, improve patient safety?"</p> <p>Methods</p> <p>We searched the Cochrane Library, MEDLINE, CINAHL, and EMBASE for randomised controlled trials published in English before September 2009. Studies were selected and appraised by two reviewers independently in consultation with colleagues, using inclusion, exclusion and appraisal criteria established a priori.</p> <p>Results</p> <p>Nine cohort studies with historical controls studies from four hospital care settings were included-intensive care unit, emergency department, surgery, and acute care. The studies used a variety of designs of safety checklists, and implemented them in different ways, however most incorporated an educational component to teach the staff how to use the checklist. The studies assessed outcomes occurring a few weeks to a maximum of 12 months post-implementation, and these outcomes were diverse.</p> <p>The studies were generally of low to moderate quality and of low levels of evidence, with all but one of the studies containing a high risk of bias.</p> <p>The results of these studies suggest some improvements in patient safety arising from use of safety checklists, but these were not consistent across all studies or for all outcomes. Some studies showed no difference in outcomes between checklist use and standard care without a checklist. Due to the variations in setting, checklist design, educational training given, and outcomes measured, it was unfeasible to accurately summarise any trends across all studies.</p> <p>Conclusions</p> <p>The included studies suggest some benefits of using safety checklists to improve protocol adherence and patient safety, but due to the risk of bias in these studies, their results should be interpreted with caution. More high quality and studies, are needed to enable confident conclusions about the effectiveness of safety checklists in acute hospital settings.</p

Nitrogen and sulphur management: challenges for organic sources in temperate agricultural systems

A current global trend towards intensification or specialization of agricultural enterprises has been accompanied by increasing public awareness of associated environmental consequences. Air and water pollution from losses of nutrients, such as nitrogen (N) and sulphur (S), are a major concern. Governments have initiated extensive regulatory frameworks, including various land use policies, in an attempt to control or reduce the losses. This paper presents an overview of critical input and loss processes affecting N and S for temperate climates, and provides some background to the discussion in subsequent papers evaluating specific farming systems. Management effects on potential gaseous and leaching losses, the lack of synchrony between supply of nutrients and plant demand, and options for optimizing the efficiency of N and S use are reviewed. Integration of inorganic and organic fertilizer inputs and the equitable re-distribution of nutrients from manure are discussed. The paper concludes by highlighting a need for innovative research that is also targeted to practical approaches for reducing N and S losses, and improving the overall synchrony between supply and demand

High-dose chemotherapy and peripheral blood stem cell support in refractory gestational trophoblastic neoplasia

We present retrospectively our experience in the use of high-dose chemotherapy and haematopoietic stem cell support (HSCS) for refractory gestational trophoblastic neoplasia (GTN) in the largest series so far reported. In all, 11 patients have been treated at three Trophoblast Centres between 1993 and 2004. The conditioning regimens comprised either Carbop-EC-T (carboplatin, etoposide, cyclophosphamide, paclitaxel and prednisolone) or CEM (carboplatin, etoposide and melphalan) or ICE (ifosfamide, carboplatin, etoposide). Two patients had complete human chorionic gonadotrophin responses, one for 4 and the other for 12 months. Three patients had partial tumour marker responses for 1–2 months. High-dose chemotherapy and HSCS for GTN is still unproven. Further studies are needed, perhaps in high-risk patients who fail their first salvage treatment

A Systematic Review of Mosquito Coils and Passive Emanators: Defining Recommendations for Spatial Repellency Testing Methodologies.

Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS), long lasting insecticide treated nets (LLINs) and insecticide treated materials (ITMs). PubMed, (National Centre for Biotechnology Information (NCBI), U.S. National Library of Medicine, NIH), MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words "Mosquito coils" "Mosquito emanators" and "Spatial repellents". It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose-response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP), which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control