586 research outputs found
Strong "quantum" chaos in the global ballooning mode spectrum of three-dimensional plasmas
The spectrum of ideal magnetohydrodynamic (MHD) pressure-driven (ballooning)
modes in strongly nonaxisymmetric toroidal systems is difficult to analyze
numerically owing to the singular nature of ideal MHD caused by lack of an
inherent scale length. In this paper, ideal MHD is regularized by using a
-space cutoff, making the ray tracing for the WKB ballooning formalism a
chaotic Hamiltonian billiard problem. The minimum width of the toroidal Fourier
spectrum needed for resolving toroidally localized ballooning modes with a
global eigenvalue code is estimated from the Weyl formula. This
phase-space-volume estimation method is applied to two stellarator cases.Comment: 4 pages typeset, including 2 figures. Paper accepted for publication
in Phys. Rev. Letter
Anderson localization of ballooning modes, quantum chaos and the stability of compact quasiaxially symmetric stellarators
The radially local magnetohydrodynamic(MHD) ballooning stability of a compact, quasiaxially symmetric stellarator (QAS), is examined just above the ballooning beta limit with a method that can lead to estimates of global stability. Here MHDstability is analyzed through the calculation and examination of the ballooning modeeigenvalue isosurfaces in the 3-space (s,α,θk); s is the edge normalized toroidal flux, α is the field linevariable, and θk is the perpendicular wave vector or ballooning parameter. Broken symmetry, i.e., deviations from axisymmetry, in the stellarator magnetic field geometry causes localization of the ballooning mode eigenfunction, and gives rise to new types of nonsymmetric eigenvalue isosurfaces in both the stable and unstable spectrum. For eigenvalues far above the marginal point, isosurfaces are topologically spherical, indicative of strong “quantum chaos.” The complexity of QAS marginal isosurfaces suggests that finite Larmor radius stabilization estimates will be difficult and that fully three-dimensional, high-nMHD computations are required to predict the beta limit.Research supported by U.S. DOE Contract No. DEAC02-76CH0373.
John Canik held a U.S. DOE National
Undergraduate Fellowship at Princeton Plasma Physics
Laboratory, during the summer of 2000
An examination of psychopathology among men who have suspended the use of violence in their intimate relationships
Heterologous expression of the isopimaric acid pathway in Nicotiana benthamiana and the effect of N-terminal modifications of the involved cytochrome P450 enzyme
Defining Major Surgery: A Delphi Consensus Among European Surgical Association (ESA) Members
Background: Major surgery is a term frequently used but poorly defined. The aim of the present study was to reach a consensus in the definition of major surgery within a panel of expert surgeons from the European Surgical Association (ESA). Methods: A 3-round Delphi process was performed. All ESA members were invited to participate in the expert panel. In round 1, experts were inquired by open- and closed-ended questions on potential criteria to define major surgery. Results were analyzed and presented back anonymously to the panel within next rounds. Closed-ended questions in round 2 and 3 were either binary or statements to be rated on a Likert scale ranging from 1 (strong disagreement) to 5 (strong agreement). Participants were sent 3 reminders at 2-week intervals for each round. 70% of agreement was considered to indicate consensus. Results: Out of 305 ESA members, 67 (22%) answered all the 3 rounds. Significant comorbidities were the only preoperative factor retained to define major surgery (78%). Vascular clampage or organ ischemia (92%), high intraoperative blood loss (90%), high noradrenalin requirements (77%), long operative time (73%) and perioperative blood transfusion (70%) were procedure-related factors that reached consensus. Regarding postoperative factors, systemic inflammatory response (76%) and the need for intensive or intermediate care (88%) reached consensus. Consequences of major surgery were high morbidity (>30% overall) and mortality (>2%). Conclusion: ESA experts defined major surgery according to extent and complexity of the procedure, its pathophysiological consequences and consecutive clinical outcomes
Age-related differences in automatic stimulus-response associations: Insights from young and older adults’ parity judgments
Anderson localization of ballooning modes, quantum chaos and the stability of compact quasiaxially symmetric stellarators
Screening for Domestic Violence Among Adult Women in the United States
BACKGROUND: Domestic violence is a problem frequently encountered in health care settings and a risk factor for physical and mental health problems. OBJECTIVE: To provide nationally representative estimates of rates of domestic violence screening among women, to identify predictors of screening, and to describe settings where women are screened. DESIGN AND PARTICIPANTS: We examined 4,821 women over the age of 18 from the second wave of Healthcare for Communities, a nationally representative household telephone survey conducted in 2000–2001. MEASUREMENTS: Self-reports concerning whether the respondent was ever asked about domestic or family violence by any health care provider. RESULTS: Only 7% (95% CI, 6%–8%) of women reported they were ever asked about domestic violence or family violence by a health care professional. Of women who were asked about abuse, nearly half (46%) were asked in a primary care setting, and 24% were asked in a specialty mental health setting. Women with risk factors for domestic violence were more likely to report being asked about it by a health care professional, but rates were still low. CONCLUSIONS: Self-reported rates of screening for domestic violence are low even among women at higher risk for abuse. These findings reinforce the importance of developing training and raising awareness of domestic violence and its health implications. This is especially true in primary care and mental health specialty settings
Are clinicians being prepared to care for abused women? A survey of health professional education in Ontario, Canada
Background: The current project undertook a province-wide survey and environmental scan of educational opportunities available to future health care providers on the topic of intimate partner violence (IPV) against women.
Methods: A team of experts identified university and college programs in Ontario, Canada as potential providers of IPV education to students in health care professions at the undergraduate and post-graduate levels. A telephone survey with contacts representing these programs was conducted between October 2005 and March 2006. The survey asked whether IPV-specific education was provided to learners, and if so, how and by whom.
Results: In total, 222 eligible programs in dentistry, medicine, nursing and other allied health professions were surveyed, and 95% (212/222) of programs responded. Of these, 57% reported offering some form of IPV-specific education, with undergraduate nursing (83%) and allied health (82%) programs having the highest rates. Fewer than half of undergraduate medical (43%) and dentistry (46%) programs offered IPV content. Postgraduate programs ranged from no IPV content provision (dentistry) to 41% offering content (nursing).
Conclusion: Significant variability exists across program areas regarding the methods for IPV education, its delivery and evaluation. The results of this project highlight that expectations for an active and consistent response by health care professionals to women experiencing the effects of violence may not match the realities of professional preparation
A COMPARATIVE MAPPING OF ENZYMES INVOLVED IN HEXOSEMONOPHOSPHATE SHUNT AND CITRIC ACID CYCLE IN THE BRAIN *
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66082/1/j.1471-4159.1963.tb05042.x.pd
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