Study of the (d,2-He) Reaction at E_d = 99 MeV

This work was supported by the National Science Foundation Grants NSF PHY 78-22774 A03, NSF PHY 81-14339, and by Indiana Universit

Fluctuating Elastic Rings: Statics and Dynamics

We study the effects of thermal fluctuations on elastic rings. Analytical expressions are derived for correlation functions of Euler angles, mean square distance between points on the ring contour, radius of gyration, and probability distribution of writhe fluctuations. Since fluctuation amplitudes diverge in the limit of vanishing twist rigidity, twist elasticity is essential for the description of fluctuating rings. We find a crossover from a small scale regime in which the filament behaves as a straight rod, to a large scale regime in which spontaneous curvature is important and twist rigidity affects the spatial configurations of the ring. The fluctuation-dissipation relation between correlation functions of Euler angles and response functions, is used to study the deformation of the ring by external forces. The effects of inertia and dissipation on the relaxation of temporal correlations of writhe fluctuations, are analyzed using Langevin dynamics.Comment: 43 pages, 9 Figure

Diagnosis and Management of Iliac Artery Endofibrosis: Results of a Delphi Consensus Study

Objective Iliac endofibrosis is a rare condition that may result in a reduction of blood flow to the lower extremity in young, otherwise healthy individuals. The data to inform everyday clinical management are weak and therefore a Delphi consensus methodology was used to explore areas of consensus and disagreement concerning the diagnosis and management of patients with suspected iliac endofibrosis. Methods A three-round Delphi questionnaire approach was used among vascular surgeons, sports physicians, sports scientists, radiologists, and clinical vascular scientists with experience of treating this condition to explore diagnosis and clinical management issues for patients with suspected iliac artery endofibrosis. Analysis is based on 18 responses to round 2 and 14 responses to round 3, with agreement reported when 70% of respondents were in agreement. Results Initially there was agreement on the typical symptoms at presentation and the need for an exercise test in the diagnosis. Round 3 clarified that duplex ultrasound was a useful tool in the diagnosis of endofibrosis. There was consensus on the most appropriate type of surgery (endarterectomy and vein patch) and that endovascular interventions were inadvisable. The final round helped to inform aspects of the natural history and post-operative surveillance. Progression of the disease was likely with continued exercise but cessation may prevent progression. Surveillance after surgery is generally recommended yearly with at least a clinical assessment. Conclusions There is broad agreement about the presenting symptoms and the investigations required to confirm (or exclude) the diagnosis of iliac endofibrosis. There was consensus on the surgical approach to repair. Disagreement existed about the specific diagnostic criteria that should be applied during non-invasive testing and about post-operative care and resumption of exercise

Separated spectral functions for the quasifree 12C(e,e′p) reaction

A separation of the longitudinal and transverse 12C(e,e′p) cross sections in the quasifree region has been performed in parallel kinematics at Q2 of 0.64 and 1.8 GeV2 for initial proton momentum <80 MeV. The separated transverse and longitudinal spectral functions at Q2=0.64GeV2 show significant differences for missing energy between 25 and 60 MeV indicating a breakdown in the single nucleon knockout picture. The transverse spectral functions exhibit definite momentum transfer dependence

Quasielastic (e,e′p) reaction on 12C,56Fe, and 197Au

We report the results from a systematic study of the quasielastic (e,e′p) reaction on 12C, 56Fe, and 197Au performed at Jefferson Lab. We have measured nuclear transparency and extracted spectral functions (corrected for radiation) over a Q2 range of 0.64–3.25 (GeV∕c)2 for all three nuclei. In addition, we have extracted separated longitudinal and transverse spectral functions at Q2 of 0.64 and 1.8 (GeV∕c)2 for these three nuclei (except for 197Au at the higher Q2). The spectral functions are compared to a number of theoretical calculations. The measured spectral functions differ in detail but not in overall shape from most of the theoretical models. In all three targets the measured spectral functions show considerable excess transverse strength at Q2=0.64 (GeV∕c)2, which is much reduced at 1.8 (GeV∕c)2

Age of Initiation and Internet Gaming Disorder: The Role of Self-Esteem

The link between early initiation and problematic use has been observed for substance use disorders; however, this link has not been as clearly established for Internet gaming disorder (IGD). Available studies indicate that individuals who initiate Internet use at younger ages exhibit an increased risk for general Internet addiction. Prior research also suggests unique cognitive processes in online gaming, such that an individual&apos;s overall sense of self-worth can become contingent upon self-esteem derived from the gaming environment. The current research examines the mediational role of self-esteem variables in the relationship between age of initiation and IGD symptomatology. Data were analyzed from 1,044 adult participants (mean age = 30.90; standard deviation: 9.28; 35.0% female) recruited from Amazon Mechanical Turk who reported playing massively multiplayer online role-playing games. Age of gaming initiation is directly linked to IGD, as earlier age predicted overall IGD symptom severity (b = -0.10, 95% confidence interval [CI: -0.17, -0.03]), controlling for self-esteem factors. In addition, self-esteem factors emerged as mediators of the effect, where global self-esteem served as a protective factor (b = -0.05, 95% CI: [-0.07, -0.02]) and high gaming-contingent self-worth (GCSW; b = -0.10, 95% CI: [-0.15, -0.04]) was associated with more negative outcomes. Earlier age of gaming initiation is associated with IGD symptomatology. Although risks of screen time are often referred to in terms of physical consequences, the present study provides support regarding the inclusion of self-esteem factors in the link between early use and IGD. © Copyright 2017, Mary Ann Liebert, Inc. 2017