Further ALMA observations and detailed modeling of the Red Rectangle

We present new high-quality ALMA observations of the Red Rectangle (a well known post-AGB object) in C17O J=6-5 and H13CN J=4-3 line emission and results from a new reduction of already published 13CO J=3-2 data. A detailed model fitting of all the molecular line data, including previous maps and single-dish spectra, was performed using a sophisticated code. These observations and the corresponding modeling allowed us to deepen the analysis of the nebular properties. We also stress the uncertainties in the model fitting. We confirm the presence of a rotating equatorial disk and an outflow, which is mainly formed of gas leaving the disk. The mass of the disk is ~ 0.01 Mo, and that of the CO-rich outflow is ~ 10 times smaller. High temperatures of ~ 100 K are derived for most components. From comparison of the mass values, we roughly estimate the lifetime of the rotating disk, which is found to be of about 10000 yr. Taking data of a few other post-AGB composite nebulae into account, we find that the lifetimes of disks around post-AGB stars typically range between 5000 and more than 20000 yr. The angular momentum of the disk is found to be high, ~ 9 Mo AU km/s, which is comparable to that of the stellar system at present. Our observations of H13CN show a particularly wide velocity dispersion and indicate that this molecule is only abundant in the inner Keplerian disk, at ~ 60 AU from the stellar system. We suggest that HCN is formed in a dense photodissociation region (PDR) due to the UV excess known to be produced by the stellar system, following chemical mechanisms that are well established for interstellar medium PDRs and disks orbiting young stars. We further suggest that this UV excess could lead to the efficient formation and excitation of PAHs and other C-bearing macromolecules, whose emission is very intense in the optical counterpart.Comment: Astronomy & Astrohysics, in press; 17 pages, 18 figures, 1 tabl

ALMA observations of the Red Rectangle, a preliminary analysis

We aim to study equatorial disks in rotation and axial outflows in post-AGB objects, as to disclose the formation and shaping mechanisms in planetary nebulae. So far, both disks and outflows had not been observed simultaneously. We have obtained high-quality ALMA observations of 12CO and 13CO J=3-2 and 12CO J=6-5 line emission in the Red Rectangle, the only post-AGB/protoplanetary object in which a disk in rotation has been mapped up to date. These observations provide an unprecedented description of the complex structure of this source. Together with an equatorial disk in rotation, we find a low-velocity outflow that occupies more or less the region placed between the disk and the optical X-shaped nebula. From our observations and preliminary modeling of the data, we confirm the previously known properties of the disk and obtain a first description of the structure, dynamics, and physical conditions of the outflow.Comment: 5 pages, 5 figure

Thermoelectric Figure of Merit of Strongly Correlated Superlattice Semiconductors

We solved the Anderson Lattice Hamiltonian to get the energy bands of a strongly correlated semiconductor by using slave boson mean field theory. The transport properties were calculated in the relaxation-time approximation,and the thermoelectric figure of merit was obtained for the strongly correlated semiconductor and its superlattice structures. We found that at room temperature $ZT$ can reach nearly 2 for the quantum wire lattice structure.We believe that it is possible to find high values of thermoelectric figure of merit from strongly correlated semiconductor superlattice systems.Comment: 4 pages, 3 figure

Warps and correlations with intrinsic parameters of galaxies in the visible and radio

From a comparison of the different parameters of warped galaxies in the radio, and especially in the visible, we find that: a) No large galaxy (large mass or radius) has been found to have high amplitude in the warp, and there is no correlation of size/mass with the degree of asymmetry of the warp. b) The disc density and the ratio of dark to luminous mass show an opposing trend: smaller values give more asymmetric warps in the inner radii (optical warps) but show no correlation with the amplitude of the warp; however, in the external radii neither is there any correlation with the asymmetry. c) A third anticorrelation arises from a comparison of the amplitude and degree of asymmetry in the warped galaxies. Hence, it seems that very massive dark matter haloes have nothing to do with the formation of warps but only with the degree of symmetry in the inner radii, and are unrelated to the warp shape for the outermost radii. Denser discs show up the same dependence.Comment: 13 pages, 2 figures, accepted to be published in A&

Serious electronic games as behavioural change interventions in healthcare-associated infections and infection prevention and control: a scoping review of the literature and future directions

Background The uptake of improvement initiatives in infection prevention and control (IPC) has often proven challenging. Innovative interventions such as ‘serious games’ have been proposed in other areas to educate and help clinicians adopt optimal behaviours. There is limited evidence about the application and evaluation of serious games in IPC. The purposes of the study were: a) to synthesise research evidence on the use of serious games in IPC to support healthcare workers’ behaviour change and best practice learning; and b) to identify gaps across the formulation and evaluation of serious games in IPC. Methods A scoping study was conducted using the methodological framework developed by Arksey and O’Malley. We interrogated electronic databases (Ovid MEDLINE, Embase Classic + Embase, PsycINFO, Scopus, Cochrane, Google Scholar) in December 2015. Evidence from these studies was assessed against an analytic framework of intervention formulation and evaluation. Results Nine hundred sixty five unique papers were initially identified, 23 included for full-text review, and four finally selected. Studies focused on intervention inception and development rather than implementation. Expert involvement in game design was reported in 2/4 studies. Potential game users were not included in needs assessment and game development. Outcome variables such as fidelity or sustainability were scarcely reported. Conclusions The growing interest in serious games for health has not been coupled with adequate evaluation of processes, outcomes and contexts involved. Explanations about the mechanisms by which game components may facilitate behaviour change are lacking, further hindering adoption

Nurse roles in antimicrobial stewardship: lessons from public sectors models of acute care service delivery in the United Kingdom.

Background: Health care services must engage all relevant healthcare workers, including nurses, in optimal antimicrobial use to address the global threat of drug-resistant infections. Reflecting upon the variety of antimicrobial stewardship (AMS) nursing models already implemented in the UK could facilitate policymaking and decisions in other settings about context-sensitive, pragmatic nurse roles. Methods: We describe purposefully selected cases drawn from the UK network of public sector nurses in AMS exploring their characteristics, influence, relations with clinical and financial structures, and role content. Results: AMS nursing has been deployed in the UK within 'vertical', 'horizontal' or 'hybrid' models. The 'vertical' model refers to a novel, often unique consultant-type role ideally suited to transform organisational practice by legitimising nurse participation in antimicrobial decisions. Such organisational improvements may not be straightforward, though, due to scalability issues. The 'horizontal' model can foster coordinated efforts to increase optimal AMS behaviours in all nurses around a narrative of patient safety and quality. Such model may be unable to address tensions between the required institutional response to sepsis and the inappropriate use of antibiotics. Finally, the 'hybrid' model would increase AMS responsibilities for all nurses whilst allocating some expanded AMS skills to existing teams of specialists such as sepsis or vascular access nurses. This model can generate economies of scale, yet it may be threatened by a lack of clarity about a nurse-relevant vision. Conclusions: A variety of models articulating the participation of nurses in antimicrobial stewardship efforts have already been implemented in public sector organisations in the UK. The strengths and weaknesses of each model need considering before implementation in other settings and healthcare systems, including precise metrics of success and careful consideration of context-sensitive, resource dependent and pragmatic solutions

Evaluation of the different numerical formats for HIL models of power converters after the adoption of VHDL-2008 by xilinx

Hardware in the loop is a widely used technique in power electronics, allowing to test and debug in real time (RT) at a low cost. In this context, field-programmable gate arrays (FPGAs) play an important role due to the high-speed requirements of RT simulations, in which area optimization is also crucial. Both characteristics, area and speed, are affected by the numerical formats (NFs) and their rounding modes. Regarding FPGAs, Xilinx is one of the largest manufacturers in the world, offering Vivado as its main design suite, but it was not until the release of Vivado 2020.2 that support for the IEEE NF libraries of VHDL-2008 was included. This work presents an exhaustive evaluation of the performance of Vivado 2020.2 in terms of area and speed using the native IEEE libraries of VHDL-2008 regarding NF. Results show that even though fixed-point NFs optimize area and speed, if a user prefers the use of floating-point NFs, with this new release, it can be synthesized—which could not be done in previous versions of Vivado. Although support for the native IEEE libraries of VHDL-2008 was included in Vivado 2020.2, it still lacks some issues regarding NF conversion during synthesis while support for simulation is not yet includedThis research received no external fundin

Appraising the quality standard underpinning international clinical practice guidelines for the selection and care of vascular access devices: a systematic review of reviews

OBJECTIVE: Catheter-related bloodstream infections are one of the most important adverse events for patients. Evidence-based practice embraces interventions to prevent and reduce catheter-related bloodstream infections in patients. At present, a growing number of guidelines exist worldwide. The purpose of the study was to assess clinical practice guidelines for peripheral and central venous access device care and prevention of related complications. DESIGN: Systematic review of clinical practice guidelines: We conducted a search of the literature published from 2005 to 2018 using Medline/PubMed, Embase, CINAHL, Ovid, ScienceDirect, Scopus and Web of Science. We also evaluated grey literature sources and websites of organisations that compiled or produced guidelines. Guideline quality was assessed with the Appraisal of Guidelines for Research and Evaluation, Second Edition tool by three independent reviewers. Cohen's kappa coefficient was used to evaluate the concordance between reviewers. RESULTS: We included seven guidelines in the evaluation. The concordance between observers was substantial, K=0.6364 (95% CI 0.0247 to 1.2259). We identified seven international guidelines, which scored poorly on crucial domains such as applicability (medium 39%), stakeholder involvement (medium 65%) and methodological rigour (medium 67%). Guidelines by Spanish Health Ministry and UK National Institute for Health and Care Excellence presented the highest quality. CONCLUSIONS: It is crucial to critically evaluate the validity and reliability of clinical practice guidelines so the best, most context-specific document is selected. Such choice is a necessary prior step to encourage and support health organisations to transfer research results to clinical practice. The gaps identified in our study may explain the suboptimal clinical impact of guidelines. Such low adoption may be mitigated with the use of implementation guides accompanying clinical documents

Fossil group origins V. The dependence of the luminosity function on the magnitude gap

In nature we observe galaxy aggregations that span a wide range of magnitude gaps between the two first-ranked galaxies of a system ($\Delta m_{12}$). There are systems with gaps close to zero (e.g., the Coma cluster), and at the other extreme of the distribution, the largest gaps are found among the so-called fossil systems. Fossil and non-fossil systems could have different galaxy populations that should be reflected in their luminosity functions. In this work we study, for the first time, the dependence of the luminosity function parameters on $\Delta m_{12}$ using data obtained by the fossil group origins (FOGO) project. We constructed a hybrid luminosity function for 102 groups and clusters at $z \le 0.25$. We stacked all the individual luminosity functions, dividing them into bins of $\Delta m_{12}$, and studied their best-fit Schechter parameters. We additionally computed a relative luminosity function, expressed as a function of the central galaxy luminosity, which boosts our capacity to detect differences, especially at the bright end. We find trends as a function of $\Delta m_{12}$ at both the bright and faint ends of the luminosity function. In particular, at the bright end, the larger the magnitude gap, the fainter the characteristic magnitude $M^\ast$. We also find differences at the faint end. In this region, the larger the gap, the flatter the faint-end slope $\alpha$. The differences found at the bright end support a dissipationless, dynamical friction-driven merging model for the growth of the central galaxy in group- and cluster-sized halos. The differences in the faint end cannot be explained by this mechanism. Other processes, such as enhanced tidal disruption due to early infall and/or prevalence of eccentric orbits, may play a role. However, a larger sample of systems with $\Delta m_{12} > 1.5$ is needed to establish the differences at the faint end.Comment: 11 pages, 10 figures, accepted for publication in A&