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  • 2000-2004  (9)
  • 1
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A proof of principle magnetic feedback stabilization experiment has been carried out to suppress the resistive wall mode (RWM), a branch of the ideal magnetohydrodynamic (MHD) kink mode under the influence of a stabilizing resistive wall, on the DIII-D tokamak device [Plasma Phys. Controlled Fusion Research (International Atomic Energy Agency, Vienna, 1986), p. 159; Phys. Plasmas 1, 1415 (1994)]. The RWM was successfully suppressed and the high beta duration above the no-wall limit was extended to more than 50 times the resistive wall flux diffusion time. It was observed that the mode structure was well preserved during the time of the feedback application. Several lumped parameter formulations were used to study the feedback process. The observed feedback characteristics are in good qualitative agreement with the analysis. These results provide encouragement to future efforts towards optimizing the RWM feedback methodology in parallel to what has been successfully developed for the n=0 vertical positional control. Newly developed MHD codes have been extremely useful in guiding the experiments and in providing possible paths for the next step. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Sustained stabilization of the n=1 kink mode by plasma rotation at beta approaching twice the stability limit calculated without a wall has been achieved in DIII-D by a combination of error field reduction and sufficient rotation drive. Previous experiments have transiently exceeded the no-wall beta limit. However, demonstration of sustained rotational stabilization has remained elusive because the rotation has been found to decay whenever the plasma is wall stabilized. Recent theory [Boozer, Phys. Rev. Lett. 86, 5059 (2001)] predicts a resonant response to error fields in a plasma approaching marginal stability to a low-n kink mode. Enhancement of magnetic nonaxisymmetry in the plasma leads to strong damping of the toroidal rotation, precisely in the high-beta regime where it is needed for stabilization. This resonant response, or "error field amplification" is demonstrated in DIII-D experiments: applied n=1 radial fields cause enhanced plasma response and strong rotation damping at beta above the no wall limit but have little effect at lower beta. The discovery of an error field amplification has led to sustained operation above the no-wall limit through improved magnetic field symmetrization using an external coil set. The required symmetrization is determined both by optimizing the external currents with respect to the plasma rotation and by use of feedback to detect and minimize the plasma response to nonaxisymmetric fields as beta increases. Ideal stability analysis and rotation braking experiments at different beta values show that beta is maintained 50% higher than the no wall stability limit for durations greater than 1 s, and approaches beta twice the no-wall limit in several cases, with steady-state rotation levels. The results suggest that improved magnetic-field symmetry could allow plasmas to be maintained well above no-wall beta limit for as long as sufficient torque is provided. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 16 (2002), S. 0 
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Hepapoietin is a naturally occurring cytokine that promotes hepatocyte growth. Animal studies have suggested that hepapoietin and hepatocyte growth factor have a potential role in the prevention and management of liver diseases. However, human studies have been lacking.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To evaluate the safety and pharmacokinetics of single escalating doses of hepapoietin in patients with chronic liver disease.〈section xml:id="abs1-3"〉〈title type="main"〉Methods:An open-label, single escalating dose trial with five different doses of hepapoietin (1, 3, 10, 30 and 100 mg) was performed. Adults with chronic, compensated, non-viral liver disease were included. Liver function tests were obtained before dosing, 24 h after hepapoietin administration and on days 4, 7, 30 and 45. All patients were followed for 45 days.〈section xml:id="abs1-4"〉〈title type="main"〉Results:Twenty-five subjects received hepapoietin, with five subjects each at 1, 3, 10, 30 and 100 mg of hepapoietin. Significant decreases occurred in total bilirubin, ammonia, partial thromboplastin time and cholesterol levels overall, and both high-density and low-density lipoprotein cholesterol showed a downward trend. An increase in albumin was observed at the 30 mg dose level. Slight decreases in haemoglobin and red blood cell levels were observed at day 4, but returned to normal levels immediately thereafter. Child–Pugh scores from day 0 to day 7 were improved in 24%, stable in 64% and worse in 12% of patients. Hepatic encephalopathy displayed changes from day 0 to day 45 with improvement in 16%, no change in 80% and worsening in 4%.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions:Hepapoietin in doses up to 100 mg is safe for use in humans. Potential benefits are suggested by significant decreases in bilirubin, ammonia, partial thromboplastin time and cholesterol levels and an increase in albumin. Further studies with multiple dosing regimens are needed to identify the clinical utility of hepapoietin in the management of chronic liver disease.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Clinical and experimental dermatology 29 (2004), S. 0 
    ISSN: 1365-2230
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: A standardized questionnaire was used to assess mobility, activity and pain in 140 randomly chosen children, who were representative of all major types and subtypes of inherited epidermolysis bullosa (EB). Pain status in these children was compared with 374 randomly selected adults with EB. The level of independence for each of six activities of daily living (ADL) (toileting; feeding; bathing; dressing; grooming; walking) was assessed in these EB children using conventional criteria for scoring. Whereas more than 90% of all EB simplex (EBS) and dominant dystrophic EB (DDEB) children were totally independent for each function (excluding walking), the frequency of similarly totally independent patients with junctional EB (JEB) and recessive dystrophic EB (RDEB) ranged from only 39% to 73%. No DDEB children and only 2% of EBS patients were totally dependent in their individual ADL, in comparison to 8–27% of JEB and 2–27% of RDEB children. Totally independent walking was reported in only 31%, 31%, 67%, and 24% of EBS, JEB, DDEB, and RDEB children, respectively. A daily level of EB-related pain was assessed in children by their parents using a linear scale of 0 (no pain) to 10 (unbearable pain). Whereas 14–19% of all children with EBS, JEB, and DDEB were graded with pain levels of more than 5, 32% of all RDEB children reportedly suffered this much pain. Increased frequencies of pain with scores more than 5 were most often noted in those patients having more clinically extensive or severe EB subtypes. These included JEB-Herlitz (20% vs. 14% in JEB-non-Herlitz) and RDEB-Hallopeau-Siemens (47% vs. 20% in all other RDEB subtypes). Only 5% of all RDEB children reportedly were pain-free, compared to 12–14% of those with EBS, JEB, and DDEB. Collectively, these data provide the first report of the specific impact different forms of EB have on daily living and coping with this genodermatosis.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Alimentary pharmacology & therapeutics 20 (2004), S. 0 
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Gastro-oesophageal reflux disease (GERD) is among the most common gastrointestinal conditions in the USA. For most symptomatic patients, reflux events occur during both daytime and night-time hours. Whereas daytime reflux events tend to be frequent but brief, reflux events that occur during sleep are comparatively less frequent but significantly longer. Longer oesophageal acid-clearance and acid-mucosal contact times during sleep are at least partly due to several physiological changes associated with sleep, including dramatic declines in saliva production and frequency of swallowing, decreased conscious perception of heartburn and consequent arousal and clearance behaviours, and slower gastric emptying. Obstructive sleep apnea syndrome and obesity seem to predispose some patients to nocturnal GERD, and the presence of either of these conditions may help to identify patients with symptoms consistent with GERD. Recognition and treatment of night-time GERD are important because it can be associated with decreased quality of life (including sleep disruption) and increased risk of serious oesophageal and respiratory complications.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 69 (2004), S. 0 
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: : Glycinin and β-conglycinin have unique functionality characteristics that contribute important properties in soy foods and soy ingredients. Limited functionality data have been published for glycinin and β-conglycinin fractions produced in pilot-scale quantities. Protein extraction conditions were previously optimized for our pilotscale fractionation process to maximize protein solubilization and subsequent product recovery. Glycinin, β-conglycinin, and intermediate (mixture of glycinin and β-conglycinin) fractions were prepared using optimized-process (OP) extraction conditions (10:1 water-to-flake ratio, 45°C) and previous conditions termed Wu process (WP) (15:1, 20°C). Viscosity, solubility, gelling, foaming, emulsification capacity, and emulsification activity and stability of the fractionated proteins, and soy protein isolate (SPI) produced from the same defatted soy white flakes were compared to evaluate functional properties of these different protein fractions. Differential scanning calorimetry, sodium dodecylsulfate-polyacrylamide gel electrophoresis, and surface hydrophobicity data were used to interpret functionality differences. OP β-conglycinin had more glycinin contamination than did the WP β-conglycinin. OP and WP solubility profiles were each similar for respective glycinin and β-conglycinin fractions. Emulsification activities and stabilities were higher for OP β-conglycinin and OP intermediate fractions compared with respective WP fractions. β-Conglycinin and SPI emulsification capacities (ECs) mirrored solubility profile, whereas glycinin ECs did not. OP glycinin had a higher foaming capacity than WP glycinin. OP and WP intermediate fraction apparent viscosities trended higher than those of other protein fractions. β-Conglycinin dispersions at pH 3 and 7 produced firm gels at 80°C, whereas glycinin dispersions formed weaker gels at 99°C and did not gel at 80°C.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric radiology 30 (2000), S. 229-235 
    ISSN: 1432-1998
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background. A new children's hospital provided the impetus to investigate radiation dose and image quality in a fluoroscope that was specially engineered for pediatric fluoroscopy. Radiation protection management recommends radiation exposures that are as low as reasonably achievable, while still maintaining diagnostic image quality.¶Objectives. To obtain comparative phantom imaging data on radiation exposure and image quality from a newly installed fluoroscope before and after optimization for pediatric imaging.¶Materials and methods. Images were acquired from various thickness phantoms, simulating differing patient sizes. The images were evaluated for visualization of high- and low-contrast objects and for radiation exposure. Effects due to use of the image intensifier anti-scatter grid were also investigated.¶Results. The optimization of the new fluoroscope for pediatric operation reduced radiation exposure by about 50 % (compared to the originally installed fluoroscope), with very little loss of image quality. Pulsed fluoroscopy was able to lower radiation dose to less than 10 % of continuous fluoroscopy, while still maintaining acceptable phantom image quality.¶Conclusion. Radiation exposure in pediatric fluoroscopy can be reduced to values well below the exposure settings that are typically found on unoptimized fluoroscopes. Pulsed fluoroscopy is considered a requisite for optimal pediatric fluoroscopy.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    International journal of stress management 7 (2000), S. 247-267 
    ISSN: 1573-3424
    Keywords: bias ; sample selection ; reactivity ; attrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Psychology
    Notes: Abstract Data from a longitudinal occupational health survey of professional fire fighters were used to explore the potential impact of two types of methodological bias: sample selection and reactivity. No significant differences on demographic variables were observed between the group who first responded after a within-study change in survey administration format (Delayed) and respondents who had completed surveys since the study's inception (Initial). However, statistically significant differences in the study's 26 outcome measures provided some evidence that between-group differences did exist and that an “administration format” type of response bias was also potentially present. The effect sizes associated with the 37 observed significant differences ranged from small to medium. These results provide a context for a reexamination of standard techniques for the identification and interpretation of survey research biases. Methods are suggested to strengthen tests for selection bias and to minimize the impact of response biases.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    International advances in economic research 6 (2000), S. 84-94 
    ISSN: 1573-966X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract Evaluating Keynes' belief that the "general theory" would create a revolution in economics, depends, in part, on what defines the key elements of the general theory. This paper presents the analytical preconditions for one of these key elements, his liquidity preference theory of money. It is argued here that Keynes's liquidity preference theory of money was both a result of his own intellectual development and a theoretical necessity, given the rest of the theoretical structure of the general theory. Specifically, this paper argues that there were two analytical preconditions for the theory of money contained in the general theory. The first was Keynes' rejection of the quantity theory of money as the basis for conducting monetary policy, a theory he inherited from his English predecessors and he himself had embraced and to which he contributed earlier in his professional career. The second was his rejection of the neoclassical loanable funds theory of interest rate determination.
    Type of Medium: Electronic Resource
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