Vertical spinal electronic device with large room temperature magnetoresistance

We report experimental transport measurements of a vertical hybrid ferromagnetic (FM)/III-V semiconductor (SC)/ferromagnetic(FM) type structure, i.e., Cr(20ML)/Co(15ML)/GaAs(50 nm, n-type)/Al/sub 0.3/Ga/sub 0.7/As(200 nm, n-type)/FeNi(30 nm). The current-voltage (I-V) characteristics reveal Schottky/tunneling type behavior in the direction of FeNi/Semiconductor/Co and observed to be dependent on external magnetic field. The magnetoresistance (MR) behavior shows a strong dependence on the measured current and field. At low fields no significant change in MR has been observed with increasing current. However, at high fields the MR initially increases with increasing current and becomes stable beyond a critical current of 10 /spl mu/A. A maximum of 12% change in the MR has been observed at room temperature, which is far larger than that of the conventional AMR effect. This property of the device could be utilized as field sensors or magnetic logic devices

Strategy for Expanding Nutrition Professionals’ Competency: A Pilot Case Study in Dissemination and Implementation Science Training

Dissemination and Implementation (D&I) science trainings are essential to build knowledge among a variety of current and future health professionals. The objective of this study was to pilot-test and assess implementation of a nutrition-specific D&I science training. Participants (students enrolled in nutrition and public health programs) completed pre/post surveys and exit interviews. Descriptive statistics and a qualitative thematic analysis used deductive coding; in which coding and theme development are directed by existing concepts. Initial coding was completed by one researcher and validated by an additional researcher to describe and provide examples of the categories the Kirkpatrick Model and Implementation Outcomes Framework. The evaluation of the training was positively supported through the Kirkpatrick Scale results (mean scores between 6.94 ± 1.7 (Learning) and 7.35 ± 1.9 (Reaction)) and qualitative findings (increased confidence in D&I science and positive feedback on active learning strategies (application-based learning, mentorship, and discussions). Participants (n=8) described the learning activities (case studies, discussions, projects), the structure of the course (flipped classroom, content, learning strategies), the setting (hybrid, online), and mentorship (continuous feedback on assignments) as enabling effective implementation, which reflects with positive Implementation Outcome findings (3.59 ± 1.26, appropriateness score 3.94 ± 0.85, and feasibility score of 4.09 ± 0.67). These findings support positive implementation feasibility and program evaluation. Future studies need to compare changes in knowledge, attitudes, and beliefs among current or future nutrition professionals before and after completing this training

Mass modelling globular clusters in the Gaia era: a method comparison using mock data from an N-body simulation of M 4

As we enter a golden age for studies of internal kinematics and dynamics of Galactic globular clusters (GCs), it is timely to assess the performance of modelling techniques in recovering the mass, mass profile, and other dynamical properties of GCs. Here, we compare different mass-modelling techniques (distribution function (DF)-based models, Jeans models, and a grid of N-body models) by applying them to mock observations from a star-by-star N-body simulation of the GC M 4 by Heggie. The mocks mimic existing and anticipated data for GCs: surface brightness or number density profiles, local stellar mass functions, line-of-sight velocities, and Hubble Space Telescope-and Gaia-like proper motions. We discuss the successes and limitations of the methods. We find that multimass DF-based models, Jeans, and N-body models provide more accurate mass profiles compared to single-mass DF-based models. We highlight complications in fitting the kinematics in the outskirts due to energetically unbound stars associated with the cluster ('potential escapers', captured neither by truncated DF models nor by N-body models of clusters in isolation), which can be avoided with DF-based models including potential escapers, or with Jeans models. We discuss ways to account for mass segregation. For example, three-component DF-based models with freedom in their mass function are a simple alternative to avoid the biases of single-mass models (which systematically underestimate the total mass, half-mass radius, and central density), while more realistic multimass DF-based models with freedom in the remnant content represent a promising avenue to infer the total mass and the mass function of remnants

Globular cluster number density profiles using Gaia DR2

Using data from Gaia DR2, we study the radial number density profiles of the Galactic globular cluster sample. Proper motions are used for accurate membership selection, especially crucial in the cluster outskirts. Due to the severe crowding in the centres, the Gaia data are supplemented by literature data from HST and surface brightness measurements, where available. This results in 81 clusters with a complete density profile covering the full tidal radius (and beyond) for each cluster. We model the density profiles using a set of single-mass models ranging from King and Wilson models to generalized lowered isothermal LIMEPY models and the recently introduced SPES models, which allow for the inclusion of potential escapers. We find that both King and Wilson models are too simple to fully reproduce the density profiles, with King (Wilson) models on average underestimating (overestimating) the radial extent of the clusters. The truncation radii derived from the LIMEPY models are similar to estimates for the Jacobi radii based on the cluster masses and their orbits. We show clear correlations between structural and environmental parameters, as a function of Galactocentric radius and integrated luminosity. Notably, the recovered fraction of potential escapers correlates with cluster pericentre radius, luminosity, and cluster concentration. The ratio of half mass over Jacobi radius also correlates with both truncation parameter and PE fraction, showing the effect of Roche lobe filling

Globular cluster number density profiles using Gaia DR2

Using data from Gaia DR2, we study the radial number density profiles of the Galactic globular cluster sample. Proper motions are used for accurate membership selection, especially crucial in the cluster outskirts. Due to the severe crowding in the centres, the Gaia data is supplemented by literature data from HST and surface brightness measurements, where available. This results in 81 clusters with a complete density profile covering the full tidal radius (and beyond) for each cluster. We model the density profiles using a set of single-mass models ranging from King and Wilson models to generalised lowered isothermal limepy models and the recently introduced spes models, which allow for the inclusion of potential escapers. We find that both King and Wilson models are too simple to fully reproduce the density profiles, with King (Wilson) models on average underestimating(overestimating) the radial extent of the clusters. The truncation radii derived from the limepy models are similar to estimates for the Jacobi radii based on the cluster masses and their orbits. We show clear correlations between structural and environmental parameters, as a function of Galactocentric radius and integrated luminosity. Notably, the recovered fraction of potential escapers correlates with cluster pericentre radius, luminosity and cluster concentration. The ratio of half mass over Jacobi radius also correlates with both truncation parameter and PE fraction, showing the effect of Roche lobe filling.Comment: 23 pages, 23 figures. Accepted in MNRA

Specificity of the osmotic stress response in Candida albicans highlighted by quantitative proteomics

We are grateful to the BBSRC for funding the CRISP Consortium (Combinatorial Responses in Stress Pathways) under the SABR Initiative (Systems Approaches to Biological Research) (BB/F00513X/1; BB/F005210/1). AJPB was also funded by the BBSRC (BB/K017365/1), the ERC (C-2009-AdG-249793), the Wellcome Trust (097377), the MRC (MR/M026663/1), and the MRC Centre for Medical Mycology and the University of Aberdeen (MR/M026663/1).Peer reviewedPublisher PD

The Life of John Wishart (1850–1926): Study of an Academic Surgical Career Prior to the Flexner Report

BACKGROUND: The 1910 Flexner Report on Medical Education in the United States and Canada is often taken as the point when medical schools in North America took on their modern form. However, many fundamental advances in surgery, such as anesthesia and asepsis, predated the report by decades. To understand the contribution of educators in this earlier period, we investigated the forgotten career of John Wishart, founding Professor of Surgery at Western University, London Ontario. METHODS: Archives at the University of Western Ontario, University of Toronto, London City Library, and Wellington County Museum were searched for material about Wishart and his times. RESULTS: A fragmented biography can be assembled from family notes and obituaries with the help of contemporary documents compiled by early 20th century medical school historians. Wishart assisted Abraham Groves in the first reported operation for which aseptic technique was used (1874). He was considered locally to perform pioneering surgery, including an appendectomy in 1886. Wishart was a founding member of the medical faculty at Western University in 1881, initially as Demonstrator of Anatomy and subsequently as its first Professor of Clinical Surgery, which post he held until 1910. Comprehensive notes from his undergraduate lectures demonstrate his teaching style, which mixed organized didacticism with practical advice. The role of the Flexner review in the termination of his professorship is hinted at in minutes of Faculty of Medicine meetings. Wishart was a foundation fellow of the American College of Surgeons and a founding physician of London\u27s Catholic hospital, St. Joseph\u27s, despite his own Protestant background. CONCLUSIONS: Wishart\u27s career comprised all the elements of modern academic surgery, including pioneering service, research, and teaching. Surgery at Western owes as much to Wishart as it does to university reorganization in response to the Flexner report. PMID: 2227097

Fluorescence-Tracking of Activation Gating in Human ERG Channels Reveals Rapid S4 Movement and Slow Pore Opening

Background: hERG channels are physiologically important ion channels which mediate cardiac repolarization as a result of their unusual gating properties. These are very slow activation compared with other mammalian voltage-gated potassium channels, and extremely rapid inactivation. The mechanism of slow activation is not well understood and is investigated here using fluorescence as a direct measure of S4 movement and pore opening. Methods and Findings: Tetramethylrhodamine-5-maleimide (TMRM) fluorescence at E519 has been used to track S4 voltage sensor movement, and channel opening and closing in hERG channels. Endogenous cysteines (C445 and C449) in the S1–S2 linker bound TMRM, which caused a 10 mV hyperpolarization of the VK of activation to 227.562.0 mV, and showed voltage-dependent fluorescence signals. Substitution of S1–S2 linker cysteines with valines allowed unobstructed recording of S3–S4 linker E519C and L520C emission signals. Depolarization of E519C channels caused rapid initial fluorescence quenching, fit with a double Boltzmann relationship, F-VON, with VK,1 = 237.861.7 mV, and VK,2 = 43.567.9 mV. The first phase, VK,1, was,20 mV negative to the conductance-voltage relationship measured from ionic tail currents (G-VK = 218.361.2 mV), and relatively unchanged in a non-inactivating E519C:S620T mutant (V K = 234.461.5 mV), suggesting the fast initial fluorescence quenching tracked S4 voltage sensor movement. The second phase of rapid quenching was absent in the S620T mutant. The E519C fluorescence upon repolarizatio

Determination of the single-ion anisotropy energy in a S = 5/2 kagome antiferromagnet using x-ray absorption spectroscopy

We report x-ray absorption and x-ray linear dichroism measurements at the Fe L-2,L-3 edges of the geometrically frustrated systems of potassium and hydronium iron jarosite. Comparison with simulated spectra, involving ligand-field multiplet calculations modeling the 3d-2p hybridization between the iron ion and the oxygen ligands, has yielded accurate estimates for the ligand metal-ion hybridization and the resulting single-ion crystal-field anisotropy energy. Using this method we provide an experimentally verified scenario for the appearance of a single-ion anisotropy in this nominally high-spin 3d(5) orbital singlet S-6 system, which accounts for features of the spin-wave dispersion in the long-range-ordered ground state of potassium iron jarosite