Point-Source Helicity Injection Current Drive System for the Pegasus Toroidal Experiment

Recent Pegasus experiments are developing solenoid-free startup techniques using point-source magnetic helicity injection. These plasma sources, called “plasma guns”, ionize a stream of gas in a discharge channel, and bias this channel with respect to an external electrode, driving current along the plasma stream, which relaxes into a tokamak-like equilibrium. The relaxed discharges formed by these injectors exhibit high current amplification, which is the ratio of total toroidal current to the gun-driven current. The development and present design of these injectors are described, and time traces from a typical discharge are presented.     

A Hall sensor array for internal current profile constraint

Measurements of the internal distribution of B in magnetically confined plasmas are required to obtain current profiles via equilibrium reconstruction with sufficient accuracy to challenge stability theory. A 16-channel linear array of InSb Hall effect sensors with 7.5 mm spatial resolution has been constructed to directly measure internal B(z)(R,t) for determination of J(ψ,t) associated with edge-localized peeling mode instabilities in the Pegasus Toroidal Experiment. The diagnostic is mounted in an electrically isolated vacuum assembly which presents a slim, cylindrical profile (～1?cm outside diameter) to the plasma using graphite as a low-Z plasma facing component. Absolute calibration of the sensors is determined via in situ cross-calibration against existing magnetic pickup coils. Present channel sensitivities are of order of 0.25 mT. Internal measurements with bandwidth of ≤25?kHz have been obtained without measurable plasma perturbation. They resolve n=1 internal magnetohydrodynamics and indicate systematic variation in J(ψ) under different stability conditions.     

The Formation of a Tokamak-like Plasma in Initial Experiments Using an Outboard Plasma Gun Current Source

Solenoid-free tokamak startup via point-source DC helicity injection is demonstrated on the Pegasus Toroidal Experiment using a high current density, low impurity plasma gun mounted near the outboard midplane. A threshold in the vacuum vertical magnetic field strength that allows the injected current filament to relax into a tokamak-like topology is observed. A simple 2-D model of the vacuum magnetic field suggests this threshold is the maximum field strength that allows a toroidally connected field null to form. Discharges with I _p ≈ 17 kA are produced using less than 2 kA of injected current and no inductive drive. The tokamak-like discharges exhibit current decay times about five times longer than the injected current decay, expansion of the plasma into the vacuum region and a significant increase in the line-integrated density.     

Effects of 28 days of resistance exercise and consuming a commercially available pre-workout supplement, NO-Shotgun?, on body composition, muscle strength and mass, markers of satellite cell activation, and clinical safety markers in males

Purpose  

This study determined the effects of 28 days of heavy resistance exercise combined with the nutritional supplement, NO-Shotgun^?, on body composition, muscle strength and mass, markers of satellite cell activation, and clinical safety markers.     

Frequency and correlates of posttraumatic-stress-disorder-like symptoms after treatment for breast cancer.

Diagnosis of life-threatening illness now meets Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994) criteria for traumatic stressor exposure for posttraumatic stress disorder (PTSD). Quality of life (QOL) and PTSD-like symptoms were assessed in 55 women posttreatment for breast cancer. PTSD symptom measures included the PTSD Checklist—Civilian Version (PCL-C) and the Impact of Events Scale. QOL was assessed using the 20-item Medical Outcomes Study Questionnaire. PTSD symptomatology was negatively related to QOL, income, and age. Time since treatment, type of cytotoxic treatment, and stage of disease were unrelated to PTSD symptoms. With suggested criteria for the PCL-C, 5% to 10% of the sample would likely meet DSM-IV PTSD criteria. Findings suggest that in survivors of breast cancer, these symptoms might be fairly common, may exceed the base rate of these symptoms in the general population, are associated with reports of poorer QOL, and, therefore, warrant further research and clinical attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changing epidemiology of congenital rubella syndrome in the United States

To describe clinical presentation and epidemiology of US infants with congenital rubella syndrome (CRS) and to identify missed opportunities for maternal vaccination, data from CRS cases reported to the National Congenital Rubella Syndrome Registry (NCRSR) from 1985 through 1996 were analyzed. Missed opportunities for maternal vaccination were defined as missed postpartum, premarital, and occupational opportunities, that is, times when rubella vaccination is recommended but was not given. From 1985 through 1996, 122 CRS cases were reported to the NCRSR. The most frequent CRS-related defect was congenital heart disease. Of the reported infants with CRS, 44% were Hispanic. Of 121 known missed opportunities for rubella vaccination among 94 mothers of infants with indigenous CRS, 98 (81%) were missed postpartum opportunities. CRS continues to occur in the United States. Hispanic infants have an increased risk of CRS. Missed opportunities for postpartum rubella vaccination were identified for 52% of indigenous CRS cases.     

Evaluation of a pregnancy-testing protocol in adolescents undergoing surgery

A 14-year-old boy presented acutely with occipital headache, nausea and vomiting. MRI showed obstructive hydrocephalus and marked bilateral cerebellar swelling with increased signal on T2-weighted imaging. Following treatment with oral corticosteroids, the clinical and radiological signs resolved. The clinical course and radiological appearances were consistent with cerebellitis associated with a significant mass effect and hydrocephalus.     

Anticipatory anxiety in women receiving chemotherapy for breast cancer.

Examined (1) the prevalence and course of anxiety before the 1st 6 infusions of cancer chemotherapy and (2) the contribution of trait anxiety, side effect expectations, and prior occurrence of posttreatment side effects to anxiety before infusions. 53 women receiving adjuvant chemotherapy for breast cancer participated. Anxiety was most prevalent and intense before the 1st infusion. Trait anxiety predicted anxiety before the 1st and subsequent infusions. Prior occurrence of posttreatment nervousness also predicted anxiety before subsequent infusions, even after accounting for trait anxiety and other posttreatment side effects. Results are discussed in terms of the role that anxiety proneness, response expectancy, and classical conditioning may play in the development of anxiety before repeated chemotherapy infusions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality factors associated with anticipatory nausea/vomiting in patients receiving cancer chemotherapy.

100 cancer chemotherapy patients were interviewed, rated the severity of pre- and posttreatment nausea and emesis, and completed the State-Trait Anxiety Inventory. In addition, scores on the Millon Behavioral Health Inventory were obtained for 59 Ss. 33% of the Ss reported having experienced anticipatory nausea, and 11% reported having experienced anticipatory vomiting. Ss who experienced anticipatory nausea had more posttreatment nausea and vomiting, were more depressed, and were characteristically more anxious than other Ss. Future despair, social alienation, inhibited personality style, gastrointestinal susceptibility, chronic tension, and confident personality style were variables that best distinguished Ss who experienced anticipatory nausea. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)