Verification of Doppler coherence imaging for 2D ion velocity measurements on DIII-D.

Coherence Imaging Spectroscopy (CIS) has emerged as a powerful tool for investigating complex ion phenomena in the boundary of magnetically confined plasma devices. The combination of Fourier-transform interferometry and high-resolution fast-framing cameras has made it possible to make sensitive velocity measurements that are also spatially resolved. However, this sensitivity makes the diagnostic vulnerable to environmental effects including thermal drifts, vibration, and magnetic fields that can influence the velocity measurement. Additionally, the ability to provide an absolute calibration for these geometries can be impacted by differences in the light-collection geometry between the plasma and reference light source, spectral impurities, and the presence of thin-films on in-vessel optics. This paper discusses the mitigation of these effects and demonstration that environmental effects result in less than 0.5 km/s error on the DIII-D CIS systems. A diagnostic comparison is used to demonstrate agreement between CIS and traditional spectroscopy once tomographic artifacts are accounted for.

Applications of Doppler-free saturation spectroscopy for edge physics studies (invited).

Doppler-free saturation spectroscopy provides a very powerful method to obtain detailed information about the electronic structure of the atom through measurement of the spectral line profile. This is achieved through a significant decrease in the Doppler broadening and essentially an elimination of the instrument broadening inherent to passive spectroscopic techniques. In this paper we present the technique and associated physics of Doppler-free saturation spectroscopy in addition to how one selects the appropriate transition. Simulations of Hδ spectra are presented to illustrate the increased sensitivity to both electric field and electron density measurements.

A temporally and spatially resolved electron density diagnostic method for the edge plasma based on Stark broadening.

An electron density diagnostic (≥1010 cm-3) capable of high temporal (ms) and spatial (mm) resolution is currently under development at Oak Ridge National Laboratory. The diagnostic is based on measuring the Stark broadened, Doppler-free spectral line profile of the n = 6-2 hydrogen Balmer series transition. The profile is then fit to a fully quantum mechanical model including the appropriate electric and magnetic field operators. The quasi-static approach used to calculate the Doppler-free spectral line profile is outlined here and the results from the model are presented for H-δ spectra for electron densities of 1010-1013 cm-3. The profile shows complex behavior due to the interaction between the magnetic substates of the atom.

Spectral survey of helium lines in a linear plasma device for use in HELIOS imaging.

Fast visible cameras and a filterscope are used to examine the visible light emission from Oak Ridge National Laboratory's Proto-MPEX. The filterscope has been configured to perform helium line ratio measurements using emission lines at 667.9, 728.1, and 706.5 nm. The measured lines should be mathematically inverted and the ratios compared to a collisional radiative model (CRM) to determine Te and ne. Increasing the number of measurement chords through the plasma improves the inversion calculation and subsequent Te and ne localization. For the filterscope, one spatial chord measurement requires three photomultiplier tubes (PMTs) connected to pellicle beam splitters. Multiple, fast visible cameras with narrowband filters are an alternate technique for performing these measurements with superior spatial resolution. Each camera contains millions of pixels; each pixel is analogous to one filterscope PMT. The data can then be inverted and the ratios compared to the CRM to determine 2-dimensional "images" of Te and ne in the plasma. An assessment is made in this paper of the candidate He I emission lines for an imaging technique.

Probing the plasma near high power wave launchers in fusion devices for static and dynamic electric fields (invited).

An exploratory study was carried out in the long-pulse tokamak Tore Supra, to determine if electric fields in the plasma around high-power, RF wave launchers could be measured with non-intrusive, passive, optical emission spectroscopy. The focus was in particular on the use of the external electric field Stark effect. The feasibility was found to be strongly dependent on the spatial extent of the electric fields and overlap between regions of strong (>∼1 kV/cm) electric fields and regions of plasma particle recycling and plasma-induced, spectral line emission. Most amenable to the measurement was the RF electric field in edge plasma, in front of a lower hybrid heating and current drive launcher. Electric field strengths and direction, derived from fitting the acquired spectra to a model including time-dependent Stark effect and the tokamak-range magnetic field Zeeman-effect, were found to be in good agreement with full-wave modeling of the observed launcher.

Dynamic Stark spectroscopic measurements of microwave electric fields inside the plasma near a high-power antenna.

Fully dynamic Stark effect visible spectroscopy was used for the first time to directly measure the local rf electric field in the boundary plasma near a high-power antenna in high-performance, magnetically confined, fusion energy experiment. The measurement was performed in the superconducting tokamak Tore Supra, in the near field of a 1­3 MW, lower-hybrid, 3.7 GHz wave-launch antenna, and combined with modeling of neutral atom transport to estimate the local rf electric field amplitude (as low as 1­2 kV/cm) and direction in this region. The measurement was then shown to be consistent with the predicted values from a 2D full-wave propagation model. Notably the measurement confirmed that the electric field direction deviates substantially from the direction in which it is launched by the waveguides as it penetrates only a few cm radially inward into the plasma from the waveguides, consistent with the model.

Reduction of edge-localized mode intensity using high-repetition-rate pellet injection in tokamak H-mode plasmas.

High repetition rate injection of deuterium pellets from the low-field side (LFS) of the DIII-D tokamak is shown to trigger high-frequency edge-localized modes (ELMs) at up to 12× the low natural ELM frequency in H-mode deuterium plasmas designed to match the ITER baseline configuration in shape, normalized beta, and input power just above the H-mode threshold. The pellet size, velocity, and injection location were chosen to limit penetration to the outer 10% of the plasma. The resulting perturbations to the plasma density and energy confinement time are thus minimal (<10%). The triggered ELMs occur at much lower normalized pedestal pressure than the natural ELMs, suggesting that the pellet injection excites a localized high-n instability. Triggered ELMs produce up to 12× lower energy and particle fluxes to the divertor, and result in a strong decrease in plasma core impurity density. These results show for the first time that shallow, LFS pellet injection can dramatically accelerate the ELM cycle and reduce ELM energy fluxes on plasma facing components, and is a viable technique for real-time control of ELMs in ITER.

Charge exchange recombination detection of low-Z and medium-Z impurities in the extreme UV using a digital lock-in technique.

More sensitive detection of charge exchange recombination lines from low-Z elements, and first-time detection from the medium-Z elements nickel and copper, has been achieved in DIII-D plasmas with a digital lock-in technique. That portion of the extreme UV spectrum varying synchronously in time with the square-wave modulation of a high energy, neutral heating beam is extracted by forming a scalar product of a correlation function with the data record of each pixel in the linear array detector. The usual, dense array of collisionally excited, metallic lines from the tokamak plasma is strongly suppressed, leaving only a sparse spectrum of lines dominated by charge exchange recombination transitions from fully stripped, low-Z elements. In plasmas with high metal content, charge exchange recombination lines from the Li-like ions of nickel and copper have been positively identified.

Barriers to Swiss guideline-recommended cholesterol management in general practice.

BACKGROUND: Standard guidelines for the management of dyslipidaemia are often not followed in general practice. The reasons for guideline non-adherence are not known. METHODS: Charts of 1000 consecutive unselected patients of 20 general practitioners in northwestern Switzerland were reviewed. An independent committee of experienced study physicians checked the data and assessed the reasons for not measuring plasma cholesterol and for not treating dyslipidaemia as recommended by guidelines. RESULTS: Complete data of 866 patients were studied. 29% of all patients qualified for secondary prevention. 6% had no additional cardiovascular risk factors (apart from cholesterol values), 24% had one and 41% had 2 or more additional cardio- vascular risk factors. Guidelines were followed in 44% of all cases and were not followed in 56%. In 37.5% of all cases we found diagnostic guideline non-adherence, and in 10% only treatment guideline non-adherence. 8.5% of all patients had both diagnostic and treatment non-adherence. The main reasons for diagnostic non-adherence were relevant comorbidity (45%) and GPs' belief that the risk did not require screening (42%). The main reasons for treatment non-adherence were GPs' belief that the risk did not require treatment (42%) and relevant comorbidity (38%). CONCLUSION: More than half of all patients aged 35-80 years are not screened or treated according to current guidelines. The reasons are to an equal extent patient-related (relevant comorbidity) and physician-related (acceptance and knowledge of guidelines). These reasons should be considered when programmes to improve the quality of GPs' adherence to guidelines are implemented.

Child pedestrians' crossing gap thresholds.

Three gender-balanced groups of 16 school children (5-6 years, 8-9 years, 11-12 years) participated in individual pretests of vision, hearing, and time to walk across a 12-m wide urban street and back. Each child then completed 10 roadside trials requiring judgement of the threshold point at which they would no longer cross in front of traffic approaching from their right. The judgements were made from a site immediately in front of a parked car at a point 2 m from the kerb and 4 m from the centre of the road. Traffic speeds and distances were measured using a laser speed and distance detector. The results indicated that, overall, distance gap thresholds remained constant regardless of vehicle approach speeds. Analysis of the thresholds for distance gap judgements for the 4-m half-street crossing showed that some of the older children could be expected to make safe decisions, but this was not so for the 5-6- and 8-9-year-olds at vehicle approach speeds above 60 kph. Almost two-thirds of the children reported using distance to judge gaps, which proved the least adequate strategy in terms of proportion of resultant safe decisions. The findings are discussed in relation to developing effective child pedestrian safety strategies.

Age related effects of restricted head movements on the useful field of view of drivers.

Eighty drivers in a sample of four groups of 20 (10 males, 10 females), aged under 30 years ('young'), 40-59 ('middle aged'), 60-69 ('older'), and 70 years and over ('oldest'), participated in tests of head rotation and of several visual functions relevant to safe driving. Head rotation data showed that the oldest drivers had lost about 1/3 of movement and that the loss tended to be more evident in males. Second attempts almost always produced slightly better results. All participants had at least 20/40 binocular vision, however, tests of monocular visual acuity, stereovision, and horizontal peripheral vision revealed that the poorest performers were aged 60 years and over and that the degree of decrement increased with age. Many of the older and oldest drivers in the sample were both severely restricted in their ability to turn their head and evidenced a loss of visual functioning. Analysis of the effect of reduced head movement on the useful field of view indicated that, for the drivers aged 60 years and over, there was an evident restriction on the distances at which approaching traffic could be brought into the central, stationary field, so that even at maximum head rotation plus one saccade (15 degrees), approaching vehicles would not be clearly perceived beyond a distance of 50 m. The findings are discussed in relation to older drivers' involvement in intersection accidents.

Testing the relative conspicuity of safety garments for New Zealand forestry workers.

The relative conspicuities of six test garments (fluorescent orange, green/red, high-contrast, fluorescent lime-yellow, white, black) were assessed to guide the selection process of a standard upper body safety garment to be used within the New Zealand logging industry. Six male and four female participants, aged between 18 and 26 years, volunteered to perform 10 trials each on a demanding, central (tracking) task, while peripherally searching colour slides for test garments displayed on each of eight positions, against a pine forest background typically found in the New Zealand forestry. During each trial, transparency luminance was first gradually increased from darkness to daylight and then decreased to darkness again within 180 s. A head mounted ASL eye tracking system (4000SU) recorded the eye line of gaze for each participant, enabling a rank order of detection to be obtained for the tested garments in each trial. The fluorescent lime-yellow, fluorescent orange and white test garments were detected earlier than any other test garments across all trials, and the fluorescent lime-yellow test garment was detected first with a higher frequency than the white test garment. It was concluded that while white may be the most visible colour in near darkness conditions, as it provides highest contrast, fluorescent lime-yellow stands out better in twilight and daylight conditions against the pine forest background. The results of this study led to the promotion of fluorescent lime-yellow as the standard safety colour used in upper body garments within the New Zealand forest industry.

5-Iodotubercidin and proglycosyn: a comparison of two glycogenic compounds in hepatocytes from fasted rats.

5-Iodotubercidin (Itu) and proglycosyn (Pro) have similar glycogenic properties. To compare their mechanisms of action, we tested them in hepatocytes from fasted rats. We show that both compounds are similar in that they stimulated glycogen synthesis, increased the concentration of synthase a, decreased that of phosphorylase a and lowered the concentration of F-2,6-P2 in the presence of glucose, lactate-pyruvate and amino acids. However, when amino acids were absent, Pro was the better stimulator of glycogenesis than Itu and in combination they elevated glycogen and synthase a concentrations synergistically. Further they differ in that (1) Itu enhanced the levels of cyclic AMP whereas Pro did not; (2) Pro depressed glucose production from gluconeogenic substrates, whereas Itu stimulated this process; (3) the inhibition of F-2,6-P2 formation and glycolysis by Pro became much weaker than that by Itu when glucose concentrations were raised from 10 to 20 mM. Inhibition of glycolysis but not that of glycogen synthesis was partly due to a phosphorylated metabolite of Itu. The present study indicates that despite their similar glycogenic effects, Itu and Pro do not share a common mechanism of action. Further, the inhibition of glycolysis and F-2,6-P2 formation by Itu cannot be explained if it acts solely as a general inhibitor of protein kinases.

Dietary components of malt extract such as maltodextrins, proteins and inorganic salts have distinct effects on glucose uptake and glycogen concentrations in rats.

As shown previously, glycogen deposition in liver and muscle is significantly greater in rats fed a diet containing barley malt extract than in those fed diets containing glucose or starch. We investigated whether particular components of malt extract (glucose oligomers, inorganic salts, protein) were responsible for this effect. Food-deprived rats were fed diets containing carbohydrates of different chain lengths [glucose, maltose, maltodextrins or malt carbohydrates (84-86 g/100 g)] in the presence and absence of inorganic salts (2 g/100 g) and maltodextrin diets (78 g/100 g) containing either no protein or 20 g casein/100 g. Dietary glucose oligomers caused higher blood glucose concentrations than consumption of glucose or maltose but had no significant influence on liver or muscle glycogen. Salt addition resulted in higher muscle glycogen concentrations but had no effect on blood glucose or liver glycogen. Hepatic glycogen concentrations were significantly greater in rats fed casein compared with those fed no protein. We propose that consumption of malt extract has the following advantages over consumption of diets containing glucose or maltose: 1) better glucose absorption related to the presence of glucose oligomers, 2) greater hepatic glycogen concentrations associated with the protein in malt extract, and 3) greater glycogen concentrations in muscle due to the presence of inorganic salts.

Is computed tomographic grading of splenic injury useful in the nonsurgical management of blunt trauma?

Seventy adult and pediatric patients with blunt splenic injury were managed nonsurgically using previously published clinical criteria without regard to the appearance of the spleen on computed tomographic (CT) scans. Seven patients (10%) who underwent delayed surgery were considered failures of nonsurgical therapy; all recovered after total splenectomy. Two radiologists, blinded to patient outcome, retrospectively reviewed the admission CT scans of all 70 patients and graded them according to three published scoring systems. Higher grades of splenic injury on CT were not associated with an increased risk of failure (Fisher's exact test, p > 0.05). Nine of ten patients with very high scores on each of the scales were successfully managed without surgery; conversely, three patients with very low scores required urgent surgery. An elevated Injury Severity Score significantly increased the risk of failure of nonsurgical management (Chi-square test of trend, p = 0.001). No failures occurred in patients under age 17 years. Our data support the hypothesis that properly selected patients can be safely observed regardless of the magnitude of splenic injury on CT scans. A decision to undergo early exploration should be based on clinical criteria, including the patient's age and associated injuries.

Stimulation of rat liver glycogen synthesis by the adenosine kinase inhibitor 5-iodotubercidin.

The adenosine kinase inhibitor 5-iodotubercidin (Itu) was found to have the following effects on glycogen metabolism in hepatocytes of fasted rats. (1) Itu strongly stimulated glycogen synthesis from different substrates (glucose, lactate plus pyruvate, dihydroxyacetone, glycerol and fructose). In cells incubated with these substrates, the well-known stimulating effect of amino acids and that of Itu was more than additive. (2) In parallel with the increase in glycogen deposition, there was an increase in synthase a and a decrease in phosphorylase a concentrations after administration of Itu. Synthase a was increased by Itu and amino acids in an additive manner, whereas the observed activation of phosphorylase after addition of amino acids was antagonized by Itu. (3) In contrast with amino acids, Itu increased neither the cell volume nor the aspartate and glutamate concentrations. (4) Itu enhanced the levels of cyclic AMP. The stimulation of glycogen deposition in the presence of Itu persisted when the cyclic AMP concentration was further increased by adenosine or 2-chloroadenosine. (5) Itu decreased the concentration of ATP, but its effects on glycogen synthesis, synthase a and phosphorylase a concentrations persisted when the ATP catabolism was prevented by adenosine. (6) The effect of Itu on glycogen synthesis was not the result of inhibition of adenosine kinase, since 5'-amino-5'-deoxyadenosine, another inhibitor of this enzyme, had no effect on glycogen deposition.

MR imaging of Asherman syndrome: total endometrial obliteration.

We present a case of Asherman syndrome involving severe intrauterine adhesions in a 31-year-old woman. Findings at hysterosalpingography and hysteroscopy are correlated with MR findings.

Refeeding of rats fasted 36 hours with five different carbohydrates and with malt extract: differential effects on glycogen deposition in liver and muscle, on plasma insulin and on plasma triglyceride levels.

Rats fasted for 36 h were refed for 1, 2, 4 or 6 h with a diet containing 12 g/100 g casein, 2 g/100 g NaCl and 86 g/100 g glucose, fructose, maltose, sucrose, starch or malt extract. Blood glucose reached constant levels after 1 to 2 h of refeeding. The increase in plasma insulin paralleled food intake rather than the increase in blood glucose. Plasma triglycerides decreased upon refeeding starch, maltose and malt extract and increased with sucrose and fructose. Recovery of absorbed carbohydrates was highest in rats refed malt extract. Glycogen deposition in muscle was highest in rats fed malt extract and lowest in those fed fructose; sucrose yielded intermediate values. Glucose, maltose and starch resulted in muscle glycogen depositions slightly lower than those obtained with malt extract. In liver, sucrose and fructose were better precursors for glycogen than glucose and starch. With carbohydrates containing only glucose units, much more glycogen was found to be deposited in total muscle than in liver. This asymmetry was less notable or even was reversed with sucrose and fructose. Glycogen deposition in muscle and in liver is influenced by the carbohydrate used for refeeding, and muscle, rather than liver, is the main glycogen storing tissue.

Blunt hepatic trauma. Nonoperative management in adults.

Fifty-six adults were identified with blunt hepatic trauma. Sixteen patients (29%) were treated successfully with nonoperative management. There were no delayed laparotomies or deaths in the nonoperative group. All patients required close observation. Eight (50%) of 16 patients required transfusion of no more than 3 U of packed red blood cells. There were two significant late complications requiring readmission. Four (25%) of 16 patients had complex fractures, yet were treated successfully without laparotomy. The quantity of fluid in the abdomen, as estimated by computed tomography, did not predict failure of treatment. Nonoperative management of blunt hepatic injuries is a useful alternative in selected patients when the course of therapy is based on the hemodynamic stability of the patient and supported by computed tomographic findings.