An iterative method for reference pattern selection in high-resolution electron backscatter diffraction (HR-EBSD).

For high (angular) resolution electron backscatter diffraction (HR-EBSD), the selection of a reference diffraction pattern (EBSP0) significantly affects the precision of the calculated strain and rotation maps. This effect was demonstrated in plastically deformed body-centred cubic and face-centred cubic ductile metals (ferrite and austenite grains in duplex stainless steel) and brittle single-crystal silicon, which showed that the effect is not only limited to measurement magnitude but also spatial distribution. An empirical relationship was then identified between the cross-correlation parameter and angular error, which was used in an iterative algorithm to identify the optimal reference pattern that maximises the precision of HR-EBSD.

Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles.

We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles.

TrueEBSD: Correcting spatial distortions in electron backscatter diffraction maps.

Electron backscatter diffraction (EBSD) in the scanning electron microscope is routinely used for microstructural characterisation of polycrystalline materials. Maps of EBSD data are typically acquired at high stage tilt and slow scan speed, leading to tilt and drift distortions that obscure or distort features in the final microstructure map. In this paper, we describe TrueEBSD, an automatic postprocessing procedure for distortion correction with pixel-scale precision. Intermediate images are used to separate tilt and drift distortion components and fit each to a physically-informed distortion model. We demonstrate TrueEBSD on three case studies (titanium, zirconium and hydride containing Zr), where distortion removal has enabled characterisation of otherwise inaccessible microstructural features.

A Receptor Tyrosine Kinase Plays Separate Roles in Sensory Integration and Associative Learning in C. elegans.

Associative learning and sensory integration are two behavioral processes that involve the sensation and processing of stimuli followed by an altered behavioral response to these stimuli, with learning requiring memory formation and retrieval. We found that the cellular and molecular actions of scd-2 dissociate sensory integration and associative learning. This was discovered through investigation of a Caenorhabditis elegans mutation (lrn-2 (mm99)) affecting both processes. After mapping and sequencing, lrn-2 was found to be allelic to the gene, scd-2scd-2-mediated associative learning and sensory integration operate in separate neurons as separate processes. We also find that memories can form from associations that are processed and stored independently from the integration of stimuli preceding an immediate behavioral decision.

A Comparative Study of Newly Licensed Registered Nurses' Stressors: 2003 and 2015.

BACKGROUND: Newly licensed nurses are overwhelmed and feel stressed as they transition from student to professional nurse. Health educators are making strides in improving the work environment, yet these nurses continue to feel stressed. Little has been done to track stress-ors to see whether they have changed over time. METHOD: A descriptive qualitative research method was used to identify the stressors of newly licensed nurses. The first focus group interviews were conducted in 2003 with 21 nurses. In 2015, the study was replicated using another group of 22 recently graduated nurses. RESULTS: There were fewer stressors noted in the 2015 group compared with the 2003 group. Six major stress-ors were identified in the 2003 group, and only three of these were noted in the 2015 group. CONCLUSION: The decline in work-related stressors could be attributed to changes in health care organizations and in state policies. Nurse educators and leaders should refine orientation and educational programs based on ongoing changes in stressors expressed by newly licensed nurses. J Contin Educ Nurs. 2018;49(3):132-140.

Evaluation of a Clinical Policy Learning Activity.

BACKGROUND: Student groups compare evidence-based practice (EBP) to actual practice defined by hospital policies in their clinical rotation sites. This article describes a pilot study evaluating this clinical learning activity. METHOD: Student and faculty surveys were developed and piloted. Purposive sampling with the surveys produced qualitative data and basic statistics to evaluate the learning activity. RESULTS: This study suggests that students' satisfaction with the clinical learning activity was generally positive. Three themes emerged, including Relevance to Clinical Practice, Course Outcomes Met, and Reinforcement of Evidence-Based Practice. Faculty surveys showed this learning activity was a useful tool for students to learn and utilize EBP. CONCLUSION: The learning activity is an effective learning and teaching strategy. Collaboration among nursing students, faculty, librarian, and nurses enhanced students' understanding of evidence related to policies in nursing practice and create a meaningful experience. Further work will focus on validation of the surveys. [J Nurs Educ. 2018;57(1):44-48.].

The effect of pattern overlap on the accuracy of high resolution electron backscatter diffraction measurements.

High resolution, cross-correlation-based, electron backscatter diffraction (EBSD) measures the variation of elastic strains and lattice rotations from a reference state. Regions near grain boundaries are often of interest but overlap of patterns from the two grains could reduce accuracy of the cross-correlation analysis. To explore this concern, patterns from the interior of two grains have been mixed to simulate the interaction volume crossing a grain boundary so that the effect on the accuracy of the cross correlation results can be tested. It was found that the accuracy of HR-EBSD strain measurements performed in a FEG-SEM on zirconium remains good until the incident beam is less than 18 nm from a grain boundary. A simulated microstructure was used to measure how often pattern overlap occurs at any given EBSD step size, and a simple relation was found linking the probability of overlap with step size.