248 research outputs found
Global genetic homogeneity in the deep-sea foraminiferan Epistominella exigua (Rotaliida: Pseudoparrellidae)
Epistominella exigua is one of the most common deep-sea foraminiferal morphospecies and has a world-wide
distribution. A recent molecular study revealed high genetic similarity between Arctic, Atlantic and Antarctic
populations of this species. Here, we show that the small-subunit (SSU) and internal transcribed spacer (ITS) rDNA
sequences of an E. exigua population from Pacific are almost identical to those reported previously from the other three
oceans. This result confirms the genetic homogeneity of E. exigua, which contrasts with the prevalence of highly
differentiated populations in planktonic and shallow-water benthic foraminiferans. We discuss special features of
diversifications mechanisms in the deep sea that may be responsible for the lack of genetic differentiation and global
distribution of some meiofauna species
Mapping Perceptions of Burnout in the Information Technology Profession: A Study Using Social Representations Theory
Job-related burnout in information technology professionals is seen as a serious issue for organizations and individuals. While the substantial body of research on job stress and burnout can provide valuable insights into the prevention of burnout in IT as well as interventions, we argue that drawing upon this work should be done with caution. In particular, generalizability of the learnings beyond the occupations studied (predominantly people-oriented and/or caregiving roles) cannot be assumed. As a first step toward assessing the applicability of existing burnout research to IT, the purpose of the study described in this paper is to understand how IT professionals make sense of and assign meaning to burnout in the profession. The study uses an approach based on social representations theory, which was first formulated by French social psychologist Serge Moscovici. Social representations are defined as the shared images and concepts through which we organize our world. Transcripts from in-depth interviews of 20 IT professionals were content- analyzed and 22 key topics (concepts) identified. Quantitative methods (including analysis of similarity and analyses to determine the relational structure of the concepts) were used to create a social representations map of these professionals’ understandings of burnout. The map provides preliminary evidence of elements that are central/peripheral to those understandings, pointing to implications for the applicability of existing theory on burnout as well as priorities for future research
Quantitative evaluation of performance of three-dimensional printed lenses
We present an analysis of the shape, surface quality, and imaging capabilities of custom three-dimensional (3-D) printed lenses. 3-D printing technology enables lens prototypes to be fabricated without restrictions on surface geometry. Thus, spherical, aspherical, and rotationally nonsymmetric lenses can be manufactured in an integrated production process. This technique serves as a noteworthy alternative to multistage, labor-intensive, abrasive processes, such as grinding, polishing, and diamond turning. Here, we evaluate the quality of lenses fabricated by Luxexcel using patented Printoptical© technology that is based on an inkjet printing technique by comparing them to lenses made with traditional glass processing technologies (grinding, polishing, etc.). The surface geometry and roughness of the lenses were evaluated using white-light and Fizeau interferometers. We have compared peak-to-valley wavefront deviation, root mean square (RMS) wavefront error, radii of curvature, and the arithmetic roughness average (Ra) profile of plastic and glass lenses. In addition, the imaging performance of selected pairs of lenses was tested using 1951 USAF resolution target. The results indicate performance of 3-D printed optics that could be manufactured with surface roughness comparable to that of injection molded lense
Modernizing Biomedical Training: Replacing Live Animal Laboratories with Human Simulation
This chapter reviews the global trend towards a modernization of biomedical education in favor of simulation-based training methods, which studies confirm improve student learning and transference of applied skills to clinical practice, reduce laboratory costs, and spare animals from harmful procedures
Inexact Newton Dogleg Methods
The dogleg method is a classical trust-region technique for globalizing Newton\u27s method. While it is widely used in optimization, including large-scale optimization via truncated-Newton approaches, its implementation in general inexact Newton methods for systems of nonlinear equations can be problematic. In this paper, we first outline a very general dogleg method suitable for the general inexact Newton context and provide a global convergence analysis for it. We then discuss certain issues that may arise with the standard dogleg implementational strategy and propose modified strategies that address them. Newton-Krylov methods have provided important motivation for this work, and we conclude with a report on numerical experiments involving a Newton-GMRES dogleg method applied to benchmark CFD problems
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The Use of In-Situ Simulation to Improve Safety in the Plastic Surgery Office: A Feasibility Study
Objective: Simulation-based interventions and education can potentially contribute to safer and more effective systems of care. We utilized in-situ simulation to highlight safety issues, regulatory requirements, and assess perceptions of safety processes by the plastic surgery office staff. Methods: A high-fidelity human patient simulator was brought to an office-based plastic surgery setting to enact a half-day full-scale, multidisciplinary medical emergency. Facilitated group debriefings were conducted after each scenario with special consideration of the principles of team training, communication, crisis management, and adherence to evidence-based protocols and regulatory standards. Abbreviated AHRQ Medical Office Safety Culture Survey was completed by the participants before and after the session. Results: The in-situ simulations had a high degree of acceptance and face validity according to the participants. Areas highlighted by the simulation sessions included rapid communication, delegation of tasks, location of emergency materials, scope of practice, and logistics of transport. The participant survey indicated greater awareness of patient safety issues following participation in simulation and debriefing exercises in 3 areas (P < 0.05): the need to change processes if there is a recognized patient safety issue (100% vs 75%), openness to ideas about improving office processes (100% vs 88%), and the need to discuss ways to prevent errors from recurring (88% vs 62%). Conclusions: Issues of safety and regulatory compliance can be assessed in an office-based setting through the short-term (half-day) use of in-situ simulation with facilitated debriefing and the review of audiovisual recordings by trained facilities inspectors
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