256 research outputs found

    A systematic review and meta-synthesis of effective nursing leadership

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    Introduction. There is a prevailing view that leadership and management development play a vital role in the creating of high performing organisations. Aim of the study. The aim of this research is to review relevant qualitative studies to identify the attributes of effective Nursing Leadership. Material and methods. Healthcare systems have experienced a substantial transformation during recent decades. This has resulted in Nurse Managers dealing with increased levels of systemic complexity and change. It’s been found,that leadership skills may help nurse managers to deal with these difficulties. Nine databases, Nursing Journals, reference lists from relevant publications and grey literature were searched. From over identified 2,000 articles, 394 were reviewed at abstract and 257 reviewed in full. Twelve articles were accepted for the systematic review. Systematic review and meta-synthesis methodologies were employed in the study. Data was collected between November 2006 and January 2007. Results. A variety of effective nursing leadership attributes were identified. Six themes were identified through metasynthesis: personal characteristics, interpersonal relationships, future vision, management of change, managerial competence and clinical experience. Conclusions. Whilst the findings of the research could not be explained by any single leadership theory, all the themes and attributes identified (except clinical experience) could be all identified in the generic leadership theory system, particularly in transformational and charismatic leadership theories. Two recommendations arise from the research. Firstly that further enquiries into Nursing Leadership should encompass the views of other relevant groups, such as patients,and other hospital staff groups. Secondly, these attributes should be empirically tested through quantitative methods

    Reconciling a significant hierarchical assembly of massive early-type galaxies at z<~1 with mass downsizing

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    Hierarchical models predict that massive early-type galaxies (mETGs) are the latest systems to be in place into the cosmic scenario (at z<~0.5), conflicting with the observational phenomenon of galaxy mass downsizing, which poses that the most massive galaxies have been in place earlier that their lower-mass counterparts (since z~0.7). We have developed a semi-analytical model to test the feasibility of the major-merger origin hypothesis for mETGs, just accounting for the effects on galaxy evolution of the major mergers strictly reported by observations. The most striking model prediction is that very few present-day mETGs have been really in place since z~1, because ~90% of the mETGs existing at z~1 are going to be involved in a major merger between z~1 and the present. Accounting for this, the model derives an assembly redshift for mETGs in good agreement with hierarchical expectations, reproducing observational mass downsizing trends at the same time.Comment: 2 pages, 1 figure, Proceedings of Symposium 2 of JENAM 2010, "Environment and the Formation of Galaxies: 30 years later", ed. I. Ferreras and A. Pasquali, Astrophysics & Space Science Proceedings, Springe

    Does the stellar disc flattening depend on the galaxy type?

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    We analyze the dependence of the stellar disc flatness on the galaxy morphological type using 2D decomposition of galaxies from the reliable subsample of the Edge-on Galaxies in SDSS (EGIS) catalogue. Combining these data with the retrieved models of the edge-on galaxies from the Two Micron All Sky Survey (2MASS) and the Spitzer Survey of Stellar Structure in Galaxies (S4^4G) catalogue, we make the following conclusions: (1) The disc relative thickness z0/hz_0/h in the near- and mid-infrared passbands correlates weakly with morphological type and does not correlate with the bulge-to-total luminosity ratio B/TB/T in all studied bands. (2) Applying an 1D photometric profile analysis overestimates the disc thickness in galaxies with large bulges making an illusion of the relationship between the disc flattening and the ratio B/TB/T. (3) In our sample the early-type disc galaxies (S0/a) have both flat and "puffed" discs. The early spirals and intermediate-type galaxies have a large scatter of the disc flatness, which can be caused by the presence of a bar: barred galaxies have thicker stellar discs, on average. On the other hand, the late-type spirals are mostly thin galaxies, whereas irregular galaxies have puffed stellar discs.Comment: 17 pages, 17 figures, accepted for publication in MNRA

    Forming Early-type Galaxies in Groups Prior to Cluster Assembly

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    We study a unique proto-cluster of galaxies, the supergroup SG1120-1202. We quantify the degree to which morphological transformation of cluster galaxies occurs prior to cluster assembly in order to explain the observed early-type fractions in galaxy clusters at z=0. SG1120-1202 at z~0.37 is comprised of four gravitationally bound groups that are expected to coalesce into a single cluster by z=0. Using HST ACS observations, we compare the morphological fractions of the supergroup galaxies to those found in a range of environments. We find that the morphological fractions of early-type galaxies (~60 %) and the ratio of S0 to elliptical galaxies (0.5) in SG1120-1202 are very similar to clusters at comparable redshift, consistent with pre-processing in the group environment playing the dominant role in establishing the observed early-type fraction in galaxy clusters.Comment: 5 pages, 2 figures, 2 tables. Accepted for publication in ApJ Letter

    The Catalog of Edge-on Disk Galaxies from SDSS. Part I: the catalog and the Structural Parameters of Stellar Disks

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    We present a catalog of true edge-on disk galaxies automatically selected from the Seventh Data Release (DR7) of the Sloan Digital Sky Survey. A visual inspection of the gg, rr and ii images of about 15000 galaxies allowed us to split the initial sample of edge-on galaxy candidates into 4768 (31.8% of the initial sample) genuine edge-on galaxies, 8350 (55.7%) non-edge-ons, and 1865 (12.5%) edge-on galaxies not suitable for simple automatic analysis because these objects show signs of interaction, warps, or nearby bright stars project on it. We added more candidate galaxies from RFGC, EFIGI, RC3, and Galaxy Zoo catalogs found in the SDSS footprints. Our final sample consists of 5747 genuine edge-on galaxies. We estimate the structural parameters of the stellar disks (the stellar disk thickness, radial scale length, and central surface brightness) in the galaxies by analyzing photometric profiles in each of the g, r, and i images. We also perform simplified 3-D modeling of the light distribution in the stellar disks of edge-on galaxies from our sample. Our large sample is intended to be used for studying scaling relations in the stellar disks and bulges and for estimating parameters of the thick disks in different types of galaxies via the image stacking. In this paper we present the sample selection procedure and general description of the sample.Comment: Accepted for publication in Ap

    Initial Mass Function Effects on the Colour Evolution of Disk Galaxies

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    Aims. In this work, we want to find out if the IMF can be determined from colour images, integrated colours, or mass-to-light ratios, especially at high redshift, where galaxies cannot be resolved into individual stars, which would enable us to investigate dependencies of the IMF on cosmological epoch. Methods. We use chemo-dynamical models to investigate the influence of the Initial Mass Function (IMF) on the evolution of a Milky Way-type disk galaxy, in particular of its colours. Results. We find that the effect of the IMF on the internal gas absorption is larger than its effect on the light from the stellar content. However, the two effects work in the opposite sense: An IMF with more high mass stars leads to brighter and bluer star-light, but also to more interstellar dust and thus to more absorption, causing a kind of “IMF degeneracy”. The most likely wavelength region in which to detect IMF effects is the infrared (i.e., JHK). We also provide photometric absorption and inclination corrections in the SDSS ugriz and the HST WFPC2 and NICMOS systems

    Polish and UK doctors' engagement with hospital management

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    Purpose – The purpose of this paper is to present the findings of a short research project, conducted in 2010 as part of a larger EU funded action investigating the participation and impact of doctors in management. The authors sought to compare the ways in which hospital doctors in the UK and Poland – countries with distinct histories – participate in management; whether they are converging and whether the type of participation found results from changes in the governance and management of these systems. Design/methodology/approach – First, a review of existing evidence and an analysis of policy documents and healthcare statistics were conducted. Identifying a lack of empirical data in the Polish context, and a potentially changing situation in the UK, the authors proceeded to collect some exploratory data in Poland, via interviews with expert informants, and to draw on data collected alongside this study in the UK from qualified doctors participating in research on management and leadership development. Findings – Hospital doctors currently hold similar types of management role in both systems, but there are signs that change is underway. In Poland, different types of medical manager and role are now emerging, whereas in the UK younger doctors appear to be expecting greater management responsibility in the future, and are starting to take up the management training now on offer. Research limitations/implications – The potential implications of these changes for the profession and policymakers in both Poland and the UK are discussed, with opportunities for further research highlighted. Originality/value – The paper provides a comparison of how medical engagement within two systems with different histories is occurring, and also of the changes underway. It provides some much needed initial insight via interviews with expert informants within the polish system, which has been under-researched in relation to the involvement of medicine in management

    The Environmental Dependence of the Evolving S0 Fraction

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    We reinvestigate the dramatic rise in the S0 fraction, f_S0, within clusters since z ~ 0.5. In particular, we focus on the role of the global galaxy environment on f_S0 by compiling, either from our own observations or the literature, robust line-of-sight velocity dispersions, sigma's, for a sample of galaxy groups and clusters at 0.1 < z < 0.8 that have uniformly determined, published morphological fractions. We find that the trend of f_S0 with redshift is twice as strong for sigma < 750 km/s groups/poor clusters than for higher-sigma, rich clusters. From this result, we infer that over this redshift range galaxy-galaxy interactions, which are more effective in lower-sigma environments, are more responsible for transforming spiral galaxies into S0's than galaxy-environment processes, which are more effective in higher-sigma environments. The rapid, recent growth of the S0 population in groups and poor clusters implies that large numbers of progenitors exist in low-sigma systems at modest redshifts (~ 0.5), where morphologies and internal kinematics are within the measurement range of current technology.Comment: Accepted for publication in The Astrophysical Journal. 13 pages, 6 figure

    Observational Comparison of Star Formation in Different Galaxy Types

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    Galaxies cover a wide range of masses and star formation histories. In this review, I summarize some of the evolutionary key features of common galaxy types. At the high-mass end, very rapid, efficient early star formation is observed, accompanied by strong enrichment and later quiescence, well-described by downsizing scenarios. In the intermediate-mass regime, early-type galaxies may still show activity in low-mass environments or when being rejuvenated by wet mergers. In late-type galaxies, we find continuous, though variable star formation over a Hubble time. In the dwarf regime, a wide range of properties from bursty activity to quiescence is observed. Generally, stochasticity dominates here, and star formation rates and efficiencies tend to be low. Morphological types and their star formation properties correlate with environment.Comment: Invited review to appear in IAU Symposium 270 on "Computational Star Formation". Editors: J. Alves, B.G. Elmegreen, J.M. Girart, and V. Trimble (Cambridge University Press). 12 pages, no figure
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