37 research outputs found
Ultrasound Guidance for Central Venous Access by Emergency Physicians in Colorado
No full textIntroduction: To survey emergency physicians (EP) regarding the frequency of use of ultrasound guidance for placement of central venous catheters (UGCVC) and to assess their perceptions regarding the technique and barriers to its implementation.Methods: A 25-question Web-based survey was e-mailed to all members of the Colorado chapter of the American College of Emergency Physicians with a listed e-mail address. A total of 3 reminderswere sent to nonresponders.Results: Responses were received from 116 out of 330 invitations. Ninety-seven percent (n¼112) of respondents indicated they have an ultrasound machine available in their emergency department, and 78% indicated they use UGCVC. Seventy-seven percent (n ¼ 90) agreed with the statement, ‘‘Ultrasound guidance is the preferred method for central venous catheter placement in the emergencydepartment.’��� However, 23% of respondents stated they have received no specific training in UGCVC. Twenty-six percent (n ¼28) of respondents stated they felt ‘‘uncomfortable’’ or ‘‘very uncomfortable’’with UGCVC, and 47% cite lack of training in UGCVC as a barrier to performing the technique.Conclusion: Although the majority of surveyed EPs feel UGCVC is a valuable technique and do perform it, a significant percentage reported receiving no training in the procedure and also reported being uncomfortable performing it. Nearly half of those surveyed cited lack of training as a barrier to more widespread implementation of UGCVC. This suggests that there continues to be a need for education and training of EPs in UGCVC
Thirring model with jump defect
No full textThe purpose of our work is to extend the formulation of classical affine Toda Models in the presence of jump defects to pure fermionic Thirring model. As a first attempt we construct the Lagrangian of the Grassmanian Thirring model with jump defect (of Backlund type) and present its conserved modified momentum and energy expressions giving a first indication of its integra-bility. Copyright © owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence
Thirring model with jump defect
No full textThe purpose of our work is to extend the formulation of classical affine Toda Models in the presence of jump defects to pure fermionic Thirring model. As a first attempt we construct the Lagrangian of the Grassmanian Thirring model with jump defect (of Backlund type) and present its conserved modified momentum and energy expressions giving a first indication of its integra-bility. Copyright © owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence
A new conservation theorem
No full textA general theorem on conservation laws for arbitrary differential equations is proved. The theorem is valid also for any system of differential equations where the number of equations is equal to the number of dependent variables. The new theorem does not require existence of a Lagrangian and is based on a concept of an adjoint equation for non-linear equations suggested recently by the author. It is proved that the adjoint equation inherits all symmetries of the original equation. Accordingly, one can associate a conservation law with any group of Lie, Lie-Backlund or non-local symmetries and find conservation laws for differential equations without classical Lagrangians.</p
Thirring model with jump defect
No full textThe purpose of our work is to extend the formulation of classical affine Toda Models in the presence of jump defects to pure fermionic Thirring model. As a first attempt we construct the Lagrangian of the Grassmanian Thirring model with jump defect (of Backlund type) and present its conserved modified momentum and energy expressions giving a first indication of its integra-bility. Copyright © owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.Instituto de Física Teórica UNESP, São PauloInstituto de Física Teórica UNESP, São Paul
Construction of Conservation Laws Using Symmetries
No full textThe concept of nonlinear self-adjointness of differential equations, introduced by the author in 2010, is discussed in detail. All linear equations and systems are nonlinearly self-adjoint. Moreover, the class of nonlinearly self-adjoint equations includes all nonlinear equations and systems having at least one local conservation law. It follows, in particular, that the integrable systems possessing infinite set of Lie-Backlund symmetries (higher-order tangent transformations) are nonlinearly self-adjoint. An explicit formula for conserved vectors associated with symmetries is provided for all nonlinearly self-adjoint differential equations and systems. The number of equations contained in the systems under consideration can be different from the number of dependent variables. A utilization of conservation laws for constructing exact solutions is discussed and illustrated by computing non-invariant solutions of the Chaplygin equations in gas dynamics.</p
BE-SAFE: Bedside Sonography for Assessment of the Fetus in Emergencies: Educational Intervention for Late-pregnancy Obstetric Ultrasound
No full textIntroduction: Late obstetric emergencies are time critical presentations in the emergency department.
Evaluation to ensure the safety of mother and child includes rapid assessment of fetal viability,
fetal heart rate (FHR), fetal lie, and estimated gestational age (EGA). Point-of-care (POC) obstetric
ultrasound (OBUS) offers the advantage of being able to provide all these measurements. We studied
the impact of POC OBUS training on emergency physician (EP) confidence, knowledge, and OBUS
skill performance on a live model.
Methods: This is a prospective observational study evaluating an educational intervention we
designed, called the BE-SAFE curriculum (BEdside Sonography for the Assessment of the Fetus in
Emergencies). Subjects were a convenience sample of EP attendings (N=17) and residents (N=14).
Prior to the educational intervention, participants completed a self-assessment survey on their
confidence regarding OBUS, and took a pre-test to assess their baseline knowledge of OBUS. They
then completed a 3-hour training session consisting of didactic and hands-on education in OBUS.
After training, each subject’s time and accuracy of performance of FHR, EGA, and fetal lie was
recorded. Post-intervention knowledge tests and confidence surveys were administered. Results were
compared with non-parametric t-tests.
Results: Pre- and post-test knowledge assessment scores for previously untrained EPs improved from
65.7% [SD=20.8] to 90% [SD=8.2] (p<0.0007). Self-confidence on a scale of 1-6 improved significantly
for identification of FHR, fetal lie, and EGA. After training, the average times for completion of OBUS
critical skills were as follows: cardiac activity (9s), FHR (68.6s), fetal lie (28.1s), and EGA (158.1 sec).
EGA estimates averaged 28w0d (25w0d-30w6d) for the model’s true gestational age of 27w0d.
Conclusion: After a focused POC OBUS training intervention, the BE-SAFE educational intervention,
EPs can accurately and rapidly use ultrasound to determine FHR, fetal lie, and estimate gestational
age in mid-late pregnancy. [West J Emerg Med. 2014;15(6):636–640
Towards a Sustainable Future: The Dynamic Adjustment Path of Irrigation Technology and Water Management in Western U.S. Agriculture
No full textTechnology adoption, Water conservation, Irrigation, Dynamic groundwater models, Sustainable agriculture, Environmental Economics and Policy, Resource /Energy Economics and Policy,
