362 research outputs found

    Monte Carlo Calculations of Electron Emission at Surface Edges

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    A Monte Carlo method using Mott cross-sections for elastic scattering and a modification of the Bethe continuous-slowing-down by inelastic scattering at inner- shell electrons has been used to calculate linescans across surface edges and steps using a two-detector system for SE and BSE with exit momenta to the right (detector A) and to the left (detector B). The step height h=10R, R, R/2, R/5 and R/10 (R = electron range) and the inclination angles =30°- 80° of edges and steps have been varied to get information about the influence of these quantities on the linescans. The signals contain contributions by surface tilt contrast, electron diffusion contrast, self-shadowing of the specimen and \u27mutual illumination\u27 caused by backscattered electrons re-entering the specimen. The latter results in a larger increase of the signal for an extended step relative to a surface edge with the same angle The difference signals A-B contain information about the surface profile. The SE A-B signal is in first order proportional to tan and the BSE A-B signal is proportional to sin where denotes the local surface tilt angle. Reconstructions of the surface profile using the calculated signals show the errors caused by signal contributions different to pure surface tilt contrast

    Transition of Experienced and New Graduate Nurses to a Pediatric Hospital

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    This study reports on the 3-, 6-, 12-, and 18-month outcomes of 118 newly hired registered nurses (RNs) who completed a 12-month transition-to-practice program at a pediatric hospital. Experienced RNs (n = 42) and new graduate RNs (n = 76) showed improved organization, prioritization, communication, and leadership skills over time. The experienced RNs reported better communication and leadership skills than the new graduate nurses. Results inform transition program development for both new and experienced nurses. The American Association of Colleges of Nursing (2012) predicts that, without a multifaceted approach, a national nursing shortage will occur by 2020. Many nurses leave their first position and sometimes the profession within the first year of employment (Baxter, 2010; Welding, 2011). Retaining nurses is a vital component of any approach to averting a nursing shortage. In an attempt to retain nurses, healthcare institutions often provide a transition-to-practice (TTP) or nurse residency program for new graduate nurses (NGN) entering the profession. The Institute of Medicine (2011) in its Future of Nursing report also recommends a transition program for nurses moving to a new specialty or to advanced practice roles. Completing a NGN transition program is associated with a decrease in nurse attrition by as much as 80% (Halfer, Graf, & Sullivan, 2008; Rush, Adamack, Gordon, Lilly, & Janke, 2013; Spector et al., 2015). This reported decrease has led to organizational interest in transition programs to improve retention. The goals of residency programs for the NGN have ranged from increasing new nurse confidence and competence, to increasing satisfaction and retention (Fink, Krugman, Casey, & Goode, 2008; Goode, Lynn, McElroy, Bednash, & Murray, 2013; Institute of Medicine, 2011; Spector et al., 2015). Although literature supports the effectiveness of transition programs for the NGN (Fink et al., 2008; Goode et al., 2013; Spector et al., 2015), there is little evidence on the experienced nurse’s transition to a new specialty practice. Furthermore, most transition programs do not report outcomes beyond the first 12 months of employment. Thus, the purpose of this study is to evaluate nurse stressors and supports during and after a 12-month transition-to-employment program for both new and experienced nurses transitioning to a pediatric practice

    Reorganize your blogs: Supporting blog re-visitation with natural language processing and visualization

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    Temporally-connected personal blogs contain voluminous textual content, presenting challenges in re-visiting and reflecting on experiences. Other data repositories have benefited from natural language processing (NLP) and interactive visualizations (VIS) to support exploration, but little is known about how these techniques could be used with blogs to present experiences and support multimodal interaction with blogs, particularly for authors. This paper presents the effect of reorganization—reorganizing the large blog set with NLP and presenting abstract topics with VIS—to support novel re-visitation experiences to blogs. The BlogCloud tool, a blog re-visitation tool that reorganizes blog paragraphs around user-searched keywords, implements reorganization and similarity-based content grouping. Through a public use session with bloggers who wrote about extended hikes, we observed the effect of NLP-based reorganization in delivering novel re-visitation experiences. Findings suggest that the re-presented topics provide new reflection materials and re-visitation paths, enabling interaction with symbolic items in memory

    Effect of workplace- versus home-based physical exercise on pain in healthcare workers:study protocol for a single blinded cluster randomized controlled trial

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    BACKGROUND: The prevalence and consequences of musculoskeletal pain is considerable among healthcare workers, allegedly due to high physical work demands of healthcare work. Previous investigations have shown promising results of physical exercise for relieving pain among different occupational groups, but the question remains whether such physical exercise should be performed at the workplace or conducted as home-based exercise. Performing physical exercise at the workplace together with colleagues may be more motivating for some employees and thus increase adherence. On the other hand, physical exercise performed during working hours at the workplace may be costly for the employers in terms of time spend. Thus, it seems relevant to compare the efficacy of workplace- versus home-based training on musculoskeletal pain. This study is intended to investigate the effect of workplace-based versus home-based physical exercise on musculoskeletal pain among healthcare workers. METHODS/DESIGN: This study was designed as a cluster randomized controlled trial performed at 3 hospitals in Copenhagen, Denmark. Clusters are hospital departments and hospital units. Cluster randomization was chosen to increase adherence and avoid contamination between interventions. Two hundred healthcare workers from 18 departments located at three different hospitals is allocated to 10 weeks of 1) workplace based physical exercise performed during working hours (using kettlebells, elastic bands and exercise balls) for 5 × 10 minutes per week and up to 5 group-based coaching sessions, or 2) home based physical exercise performed during leisure time (using elastic bands and body weight exercises) for 5 × 10 minutes per week. Both intervention groups will also receive ergonomic instructions on patient handling and use of lifting aides etc. Inclusion criteria are female healthcare workers working at a hospital. Average pain intensity (VAS scale 0-10) of the back, neck and shoulder (primary outcome) and physical exertion during work, social capital and work ability (secondary outcomes) is assessed at baseline and 10-week follow-up. Further, postural balance and mechanical muscle function is assessed during clinical examination at baseline and follow-up. DISCUSSION: This cluster randomized trial will investigate the change in self-rated average pain intensity in the back, neck and shoulder after either 10 weeks of physical exercise at the workplace or at home. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01921764)

    The role of Schizosaccharomyces pombe SUMO ligases in genome stability

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    SUMOylation is a post-translational modification that affects a large number of proteins, many of which are nuclear. While the role of SUMOylation is beginning to be elucidated, it is clear that understanding the mechanisms that regulate the process is likely to be important. Control of the levels of SUMOylation is brought about through a balance of conjugating and deconjugating activities, i.e. of SUMO (small ubiquitin-related modifier) conjugators and ligases versus SUMO proteases. Although conjugation of SUMO to proteins can occur in the absence of a SUMO ligase, it is apparent that SUMO ligases facilitate the SUMOylation of specific subsets of proteins. Two SUMO ligases in Schizosaccharomyces pombe, Pli1 and Nse2, have been identified, both of which have roles in genome stability. We report here on a comparison between the properties of the two proteins and discuss potential roles for the proteins

    The Versatile Molecular Complex Component LC8 Promotes Several Distinct Steps of Flagellar Assembly

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    LC8 is present in various molecular complexes. However, its role in these complexes remains unclear. We discovered that although LC8 is a subunit of the radial spoke (RS) complex in Chlamydomonas flagella, it was undetectable in the RS precursor that is converted into the mature RS at the tip of elongating axonemes. Interestingly, LC8 dimers bound in tandem to the N-terminal region of a spoke phosphoprotein, RS protein 3 (RSP3), that docks RSs to axonemes. LC8 enhanced the binding of RSP3 N-terminal fragments to purified axonemes. Likewise, the N-terminal fragments extracted from axonemes contained LC8 and putative spoke-docking proteins. Lastly, perturbations of RSP3’s LC8-binding sites resulted in asynchronous flagella with hypophosphorylated RSP3 and defective associations between LC8, RSs, and axonemes. We propose that at the tip of flagella, an array of LC8 dimers binds to RSP3 in RS precursors, triggering phosphorylation, stalk base formation, and axoneme targeting. These multiple effects shed new light on fundamental questions about LC8-containing complexes and axoneme assembly

    Directly Imaging Rocky Planets from the Ground

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    Over the past three decades instruments on the ground and in space have discovered thousands of planets outside the solar system. These observations have given rise to an astonishingly detailed picture of the demographics of short-period planets, but are incomplete at longer periods where both the sensitivity of transit surveys and radial velocity signals plummet. Even more glaring is that the spectra of planets discovered with these indirect methods are either inaccessible (radial velocity detections) or only available for a small subclass of transiting planets with thick, clear atmospheres. Direct detection can be used to discover and characterize the atmospheres of planets at intermediate and wide separations, including non-transiting exoplanets. Today, a small number of exoplanets have been directly imaged, but they represent only a rare class of young, self-luminous super-Jovian-mass objects orbiting tens to hundreds of AU from their host stars. Atmospheric characterization of planets in the <5 AU regime, where radial velocity (RV) surveys have revealed an abundance of other worlds, is technically feasible with 30-m class apertures in combination with an advanced AO system, coronagraph, and suite of spectrometers and imagers. There is a vast range of unexplored science accessible through astrometry, photometry, and spectroscopy of rocky planets, ice giants, and gas giants. In this whitepaper we will focus on one of the most ambitious science goals --- detecting for the first time habitable-zone rocky (<1.6 R_Earth) exoplanets in reflected light around nearby M-dwarfsComment: 8 pages, 1 figure, Astro2020 Science White Pape

    The N-terminus of CD14 acts to bind apoptotic cells and confers rapid-tethering capabilities on non-myeloid cells:CD14 and rapid tethering of apoptotic cells

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    Cell death and removal of cell corpses in a timely manner is a key event in both physiological and pathological situations including tissue homeostasis and the resolution of inflammation. Phagocytic clearance of cells dying by apoptosis is a complex sequential process comprising attraction, recognition, tethering, signalling and ultimately phagocytosis and degradation of cell corpses. A wide range of molecules acting as apoptotic cell-associated ligands, phagocyte-associated receptors or soluble bridging molecules have been implicated within this process. The role of myeloid cell CD14 in mediating apoptotic cell interactions with macrophages has long been known though key molecules and residues involved have not been defined. Here we sought to further dissect the function of CD14 in apoptotic cell clearance. A novel panel of THP-1 cell-derived phagocytes was employed to demonstrate that CD14 mediates effective apoptotic cell interactions with macrophages in the absence of detectable TLR4 whilst binding and responsiveness to LPS requires TLR4. Using a targeted series of CD14 point mutants expressed in non-myeloid cells we reveal CD14 residue 11 as key in the binding of apoptotic cells whilst other residues are reported as key for LPS binding. Importantly we note that expression of CD14 in non-myeloid cells confers the ability to bind rapidly to apoptotic cells. Analysis of a panel of epithelial cells reveals that a number naturally express CD14 and that this is competent to mediate apoptotic cell clearance. Taken together these data suggest that CD14 relies on residue 11 for apoptotic cell tethering and it may be an important tethering molecule on so called 'non-professional' phagocytes thus contributing to apoptotic cell clearance in a non-myeloid setting. Furthermore these data establish CD14 as a rapid-acting tethering molecule, expressed in monocytes, which may thus confer responsiveness of circulating monocytes to apoptotic cell derived material. © 2013 Thomas et al
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