Isotropic magnetometry with simultaneous excitation of orientation and alignment CPT resonances

Atomic magnetometers have very high absolute precision and sensitivity to magnetic fields but suffer from a fundamental problem: the vectorial or tensorial interaction of light with atoms leads to "dead zones", certain orientations of magnetic field where the magnetometer loses its sensitivity. We demonstrate a simple polarization modulation scheme that simultaneously creates coherent population trapping (CPT) in orientation and alignment, thereby eliminating dead zones. Using $^{87}$Rb in a 10 Torr buffer gas cell we measure narrow, high-contrast CPT transparency peaks in all orientations and also show absence of systematic effects associated with non-linear Zeeman splitting.Comment: 4 pages, 4 figure

Grade 1 spondylolisthesis and interspinous device placement: removal in six patients and analysis of current data

This is the published version. Information that is created by or for the US government on this site is within the public domain. Public domain information on the National Library of Medicine (NLM) Web pages may be freely distributed and copied. However, it is requested that in any subsequent use of this work, NLM be given appropriate acknowledgment.In the treatment of patients with Grade 1 spondylolisthesis, the use of interspinous devices has been controversial for nearly a decade. Several authors have suggested that Grade 1 spondylolisthesis be considered a contraindication for interspinous device placement. Methods: We removed interspinous devices in six symptomatic Grade 1 spondylolisthesis patients and analyzed pertinent literature. Results: All six patients reported an improvement in symptoms following device removal and subsequent instrumented fusion. One patient who had not been able to walk due to pain regained the ability to walk. Several articles were identified related to spondylolisthesis and interspinous devices. Conclusions: Regarding patients receiving interspinous devices for symptomatic lumbar spinal stenosis, several high-quality studies have failed to demonstrate a statistical difference in outcomes between patients with or without Grade 1 spondylolisthesis. Nevertheless, surgeons should have a high degree of suspicion when considering use of interspinous devices in this patient population

Fruit anatomy of the genus Bupleurum (Apiaceae) in northeastern China and notes on systematic implications

The fruit anatomy of all eight species of the genus Bupleurum L. mentioned in the most recent literature from northeastern China was studied for the first time. The eight species were divided into two groups based on the shape of the mericarps in transverse section. The first group (round mericarps without prominent ribs) includes B. longiradiatum and B. komarovianum, and the second group (angular mericarps with prominent ribs) includes B. angustissimum, B. bicaule, B. chinense, B. euphorbioides, B. scorzonerifolium and B. sibiricum. The second group can be further subdivided into group 2a (large vittae, very small vascular bundles) — B. euphorbioides and B. sibiricum, and group 2b (small vittae, large vascular bundles) — B. angustissimum, B. bicaule, B. chinense and B. scorzonerifolium. This result closely supports the traditional classification system which was based on gross morphology (plant height; leaf shape and size; involucre number, size and shape). The only exception is that B. komarovianum should not be close to the second group, but close to B. longiradiatum. Group 1 corresponds with Bupleurum sect. Longifolia and group 2 with sect. Eubupleura; group 2a with ser. Ranunculoides and group 2b with ser. Falcata. Fruit anatomical characters seem to have potential for evaluating infrageneric relationships in the genus Bupleurum

Structure of HLA-A*0301 in complex with a peptide of proteolipid protein: insights into the role of HLA-A alleles in susceptibility to multiple sclerosis

The structure of the human major histocompatability (MHC) class I molecule HLA-A*0301 (HLA-A3) in complex with a nonameric peptide (KLIETYFSK) has been determined by X-ray crystallography to 2.7 Å resolution. HLA-A3 is a predisposing allele for multiple sclerosis (MS), an autoimmune disease of the central nervous system. The KLIETYFSK peptide is a naturally processed epitope of proteolipid protein, a myelin protein and candidate target for immune-mediated myelin destruction in MS. Comparison of the structure of HLA-A3 with that of HLA-A2, an MHC class I molecule which is protective against MS, indicates that both MHC class I molecules present very similar faces for T-cell receptor recognition whilst differing in the specificity of their peptide-binding grooves. These characteristics may underlie the opposing (predisposing versus protective) associations that they exhibit both in humans and in mouse models of MS-like disease. Furthermore, subtle alterations within the peptide-binding groove of HLA-A3 and other A3-like MHC class I molecules, members of the so-called A3 superfamily, may be sufficient to alter their presentation of autoantigen peptides such as KLIETYFSK. This in turn may modulate their contribution to the associated risk of autoimmune disease

Towards universal quantum computation through relativistic motion

We show how to use relativistic motion to generate continuous variable Gaussian cluster states within cavity modes. Our results can be demonstrated experimentally using superconducting circuits where tuneable boundary conditions correspond to mirrors moving with velocities close to the speed of light. In particular, we propose the generation of a quadripartite square cluster state as a first example that can be readily implemented in the laboratory. Since cluster states are universal resources for universal one-way quantum computation, our results pave the way for relativistic quantum computation schemes

Are some fund managers better than others? Manager characteristics and fund performance

CITATION: Friis, L. B. & Smit, E. v d M. 2004. Are some fund managers better than others? Manager characteristics and fund performance. South African Journal of Business Management, 35(3):a660, doi:10.4102/sajbm.v35i3.660.The original publication is available at https://sajbm.orgThe research objective has been to find out whether fund manager characteristics help explain fund performance and propensity to risk taking. Eight independent variables; manager age, tenure of the manager with the fund, years of education, whether the manager holds a MBA or CA/CFA qualification, management team size, fund age and fund objective are regressed on measures of fund performance and riskiness. The findings of the study are highly significant and show that fund performance and riskiness are impacted upon by managers’ qualifications. One can expect better risk-adjusted performance from a fund manager who holds a CA/CFA qualification. Results show that these managers outperform managers without these qualifications, while taking on less risk than managers with MBA qualifications.https://sajbm.org/index.php/sajbm/article/view/660Publisher's versio

Simulation-based assessment of upper abdominal ultrasound skills

Background: Ultrasound is a safe and effective diagnostic tool used within several specialties. However, the quality of ultrasound scans relies on sufficiently skilled clinician operators. The aim of this study was to explore the validity of automated assessments of upper abdominal ultrasound skills using an ultrasound simulator. Methods: Twenty five novices and five experts were recruited, all of whom completed an assessment program for the evaluation of upper abdominal ultrasound skills on a virtual reality simulator. The program included five modules that assessed different organ systems using automated simulator metrics. We used Messick’s framework to explore the validity evidence of these simulator metrics to determine the contents of a final simulator test. We used the contrasting groups method to establish a pass/fail level for the final simulator test. Results: Thirty seven out of 60 metrics were able to discriminate between novices and experts (p &lt; 0.05). The median simulator score of the final simulator test including the metrics with validity evidence was 26.68% (range: 8.1–40.5%) for novices and 85.1% (range: 56.8–91.9%) for experts. The internal structure was assessed by Cronbach alpha (0.93) and intraclass correlation coefficient (0.89). The pass/fail level was determined to be 50.9%. This pass/fail criterion found no passing novices or failing experts. Conclusions: This study collected validity evidence for simulation-based assessment of upper abdominal ultrasound examinations, which is the first step toward competency-based training. Future studies may examine how competency-based training in the simulated setting translates into improvements in clinical performances.</p