Slow wave ion heating and parametric instabilities in the HELIX helicon source

The primary focus of the experiments described here is to determine the mechanism responsible for intrinsic ion heating in helicon sources. Two possible mechanisms have been identified: ion Landau damping of the slow wave and parametrically driven instabilities. Consistent with ion Landau damping of the slow wave, the perpendicular ion temperatures 35 cm downstream of the RF antenna are largest when the RF frequency matches the local lower hybrid frequency; the condition at which the slow wave has a maximum in perpendicular wave number (perpendicular with respect to the applied magnetic field) due to a lower hybrid resonance. The ion temperatures also peak at the edge of the plasma where theory predicts the slow wave should have the largest amplitude and perpendicular wave number. Consistent with ion heating due to parametrically driven instabilities, parametrically driven low frequency waves are observed for the same conditions at which the ion temperatures 5 cm downstream of the RF antenna are largest. The measured characteristics of the low frequency wave suggest that the wave is an electrostatic ion acoustic wave. The electrostatic and electromagnetic features of the parametrically driven waves as a function of magnetic field and RF frequency are also presented and discussed

Resonant ion heating in a helicon plasma

A resonant ion heating system has been developed for heating ions and controlling the ion temperature anisotropy in a helicon plasma source. The system uses two rectangular coils placed on either side of the cylindrical pyrex vacuum chamber to create a time dependent magnetic field transverse to the steady state axial field. A 1 kW, 25--125 kHz RF generator powers the coils. The parallel and perpendicular ion temperatures in argon plasmas are measured with a laser induced fluorescence diagnostic tuned to a metastable argon ion transition. Ion heating of over 800% has been measured for the perpendicular ion temperatures with an increase of 70% in the parallel direction. This temperature increase occurs for a specific ratio of heating frequency to ion cyclotron frequency. Evidence suggesting that ion Bernstein waves are responsible for the ion heating is presented

Methods and materials for detection of multiple sclerosis

Methods and materials for diagnosis of a multiple sclerosis disease state. Antigenic blood fractions from patients clinically diagnosed for multiple sclerosis are employed to generate heterologous species antibodies. Novel antibody preparations are employed to detect the presence or absence, in a blood sample of a patient to be tested, of immunologically significant components specifically associated with a multiple sclerosis disease state

Leukocyte Expression of Heme Oxygenase-1 [hmox1] Varies Inversely with Severity of Tricuspid Regurgitation in Acute Pulmonary Embolism.

Objective: Pulmonary embolism (PE) can cause intracardiac hemolysis and increased plasma hemoglobin and arginase-1, which can worsen pulmonary vasoconstriction. We test the hypothesis that patients with PE that causes tricuspid regurgitation (TR), indicative of higher pulmonary arterial pressures, have decreased leukocyte expression of hmox-1 compared with patients with PE and no TR and patients without PE. Design: Prospective, noninterventional study. Patients: Normotensive patients with suspected PE (n=87) who underwent CT pulmonary angiography and transthoracic Doppler-echocardiography. Measurements: Significant TR was defined as a jet velocity > 2.7m/s. Leukocyte expression of hmox-1, haptoglobin, haptoglobin related gene, the haptoglobin receptor, CD163 and cox-2 genes were assessed by quantitative rtPCR, and the hmox-1 promoter was examined for the −413 A→T SNP and GT repeat polymorphisms. Results: Of the 44 (50%) with PE+, 22 had TR+, and their mean pulmonary vascular occlusion (39±32%) did not differ significantly from patients who were TR− (28±26%, P=0.15). Patients with PE+ and TR+ had significantly lower expression of hmox-1 and haptoglobin genes than patients without PE+ and no TR. Expression of hmox-1 varied inversely with TR velocity (r2=0.45, P<0.001) for PE+ (n=22) but not patients without PE. Hmox-1 expression did not vary significantly with genotype. Cox-2 did not differ between groups and had no correlation with TR. Conclusions: Severity of TR varied inversely with hmox-1 expression, suggesting that hmox-1 expression affects pulmonary vascular reactivity after PE

Leptin is a four-helix bundle: secondary structure by NMR

AbstractLeptin is a signaling protein that in its mutant forms has been associated with obesity and Type II diabetes. The lack of sequence similarity has precluded analogies based on structural resemblance to known systems. Backbone NMR signals for mouse leptin (13C/15N -labeled) have been assigned and its secondary structure reveals it to be a four-helix bundle cytokine. Helix lengths and disulfide pattern are in agreement with leptin as a member of the short-helix cytokine family. A three-dimensional model was built verifying the mechanical consistency of the identified elements with a short-helix cytokine core

Structural, item, and test generalizability of the psychopathology checklist - revised to offenders with intellectual disabilities

The Psychopathy Checklist–Revised (PCL-R) is the most widely used measure of psychopathy in forensic clinical practice, but the generalizability of the measure to offenders with intellectual disabilities (ID) has not been clearly established. This study examined the structural equivalence and scalar equivalence of the PCL-R in a sample of 185 male offenders with ID in forensic mental health settings, as compared with a sample of 1,212 male prisoners without ID. Three models of the PCL-R’s factor structure were evaluated with confirmatory factor analysis. The 3-factor hierarchical model of psychopathy was found to be a good fit to the ID PCL-R data, whereas neither the 4-factor model nor the traditional 2-factor model fitted. There were no cross-group differences in the factor structure, providing evidence of structural equivalence. However, item response theory analyses indicated metric differences in the ratings of psychopathy symptoms between the ID group and the comparison prisoner group. This finding has potential implications for the interpretation of PCL-R scores obtained with people with ID in forensic psychiatric settings

The Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) Collaborative Quality Improvement Initiative in Percutaneous Coronary Interventions

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72388/1/j.1540-8183.2002.tb01071.x.pd