10 results
P.054 Clinical characteristics and outcomes of patients treated for acromegaly at The Ottawa Hospital
- F Alkherayf, T Li, J Malcolm, A Arnaout, H Lochnan, E Keely, C Agbi, M Doyle
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- Journal:
- Canadian Journal of Neurological Sciences / Volume 45 / Issue s2 / June 2018
- Published online by Cambridge University Press:
- 27 June 2018, p. S30
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Background: Acromegaly is associated with significant morbidity. The purpose of this study was to establish characteristics and outcomes of patients treated for acromegaly at The Ottawa Hospital, to compare our results with published reports from other centers and to identify opportunities to improve patient care. Methods: A retrospective chart review of patients surgically and medically treated for acromegaly between January 1, 2007 and December 31, 2016 was completed. Demographic information, biochemical data, presenting features, disease comorbidities, treatment interventions, and were collected. Results: Fifty-one patients were identified using CCI/ICD-10 codes and IGF-1 levels. Similar to other centers, the majority of patients had a macroadenoma (78.4% vs 11.8%) with a high percentage invading the cavernous sinus (57.5%). While surgical intervention was performed in 90% of patients, only 23.3% of patient achieved surgical cure (IGF-1 normalization within reference range). Approximately 30% of patients were controlled with adjuvant medical therapy while more than 40 % had elevated IGF-1 levels at last follow-up. Radiotherapy was less commonly used. Conclusions: Despite a multi-modal treatment approach for acromegaly, outcomes are variable. This study highlights the need for further research to better understand factors associated with surgical cure, response to medical therapy and the role of radiotherapy.
Testing the Wind-shock Paradigm for B-Type Star X-Ray Production with θ Car
- T. F. Doyle, V. Petit, D. Cohen, M. Leutenegger
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- Journal:
- Proceedings of the International Astronomical Union / Volume 12 / Issue S329 / November 2016
- Published online by Cambridge University Press:
- 28 July 2017, p. 395
- Print publication:
- November 2016
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We present Chandra X-ray grating spectroscopy of the B0.2V star, θ Carina. θ Car is in a critical transition region between the latest O-type and earliest B-type stars, where some stars are observed to have UV-determined wind densities much lower than theoretically expected (e.g., Marcolino et al. 2009). In general, X-ray emission in this low-density wind regime should be less prominent than for O-stars (e.g., Martins et al. 2005), but observations suggest a higher than expected X-ray emission filling factor (Lucy 2012; Huenemoerder et al. 2012); if a larger fraction of the wind is shock-heated, it could explain the weak UV wind signature seen in weak wind stars, but this might severely challenge predictions of radiatively-driven wind theory.
We measured the line widths of several He-, H-like and Fe ions and the f/i ratio of He-like ions in the X-ray spectrum, which improves upon the results from Nazé et al. (2008) (XMM-Newton RGS) with additional measurements (Chandra HETG) of Mgxi and Sixiii by further constraining the X-ray emission location. The f/i ratio is modified by the proximity to the UV-emitting stellar photosphere, and is therefore a diagnostic of the radial location of the X-ray emitting plasma. The measured widths of X-ray lines are narrow, <300 km s−1 and the f/i ratios place the X-rays relatively close to the surface, both implying θ Car is a weak wind star. The measured widths are also consistent with other later-type stars in the weak wind regime, β Cru (Cohen et al. 2008), for example, and are smaller on average than earlier weak wind stars such as μ Col (Huenemoerder et al. 2012). This could point to a spectral type divide, where one hypothesis, low density, works for early-B type stars and the other hypothesis, a larger fraction of shock-heated gas, explains weak winds in late-O type stars. Archival IUE data still needs to be analyzed to determine the mass loss rate and hydrodynamical simulations will be compared with observations to determine which hypothesis works for θ Car.
A flight test to demonstrate flutter and evaluate the flutterometer
- R. Lind, D. F. Voracek, R. Truax, T. Doyle, S. Potter, M. Brenner
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- Journal:
- The Aeronautical Journal / Volume 107 / Issue 1076 / October 2003
- Published online by Cambridge University Press:
- 04 July 2016, pp. 577-588
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A project was recently completed that investigated the ability to predict the onset of flutter using tools like the flutterometer. This project used an experiment called the aerostructures test wing that was flown while mounted to the flight test fixture on an F-15. Several flight tests were conducted to expand the envelope and determine the aeroelastic dynamics of the experiment. The final flight ended with destruction of the experiment due to the onset of flutter. The flutterometer attempted to predict this onset by analysing the flight data. The results indicate the flutterometer is able to generate a conservative estimate of the flight conditions associated with flutter. This paper details the flight tests of the experiment and the resulting predictions from the flutterometer.
Galaxy and Mass Assembly (GAMA): Optimal Tiling of Dense Surveys with a Multi-Object Spectrograph
- A. Robotham, S. P. Driver, P. Norberg, I. K. Baldry, S. P. Bamford, A. M. Hopkins, J. Liske, J. Loveday, J. A. Peacock, E. Cameron, S. M. Croom, I. F. Doyle, C. S. Frenk, D. T. Hill, D. H. Jones, E. van Kampen, L. S. Kelvin, K. Kuijken, R. C. Nichol, H. R. Parkinson, C. C. Popescu, M. Prescott, R. G. Sharp, W. J. Sutherland, D. Thomas, R. J. Tuffs
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- Journal:
- Publications of the Astronomical Society of Australia / Volume 27 / Issue 1 / 2010
- Published online by Cambridge University Press:
- 02 January 2013, pp. 76-90
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A heuristic greedy algorithm is developed for efficiently tiling spatially dense redshift surveys. In its first application to the Galaxy and MassAssembly (GAMA) redshift survey we find it rapidly improves the spatial uniformity of our data, and naturally corrects for any spatial bias introduced by the 2dF multi-object spectrograph. We make conservative predictions for the final state of the GAMA redshift survey after our final allocation of time, and can be confident that even if worse than typical weather affects our observations, all of our main survey requirements will be met.
Contributors
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- By Aakash Agarwala, Linda S. Aglio, Rae M. Allain, Paul D. Allen, Houman Amirfarzan, Yasodananda Kumar Areti, Amit Asopa, Edwin G. Avery, Patricia R. Bachiller, Angela M. Bader, Rana Badr, Sibinka Bajic, David J. Baker, Sheila R. Barnett, Rena Beckerly, Lorenzo Berra, Walter Bethune, Sascha S. Beutler, Tarun Bhalla, Edward A. Bittner, Jonathan D. Bloom, Alina V. Bodas, Lina M. Bolanos-Diaz, Ruma R. Bose, Jan Boublik, John P. Broadnax, Jason C. Brookman, Meredith R. Brooks, Roland Brusseau, Ethan O. Bryson, Linda A. Bulich, Kenji Butterfield, William R. Camann, Denise M. Chan, Theresa S. Chang, Jonathan E. Charnin, Mark Chrostowski, Fred Cobey, Adam B. Collins, Mercedes A. Concepcion, Christopher W. Connor, Bronwyn Cooper, Jeffrey B. Cooper, Martha Cordoba-Amorocho, Stephen B. Corn, Darin J. Correll, Gregory J. Crosby, Lisa J. Crossley, Deborah J. Culley, Tomas Cvrk, Michael N. D'Ambra, Michael Decker, Daniel F. Dedrick, Mark Dershwitz, Francis X. Dillon, Pradeep Dinakar, Alimorad G. Djalali, D. John Doyle, Lambertus Drop, Ian F. Dunn, Theodore E. Dushane, Sunil Eappen, Thomas Edrich, Jesse M. Ehrenfeld, Jason M. Erlich, Lucinda L. Everett, Elliott S. Farber, Khaldoun Faris, Eddy M. Feliz, Massimo Ferrigno, Richard S. Field, Michael G. Fitzsimons, Hugh L. Flanagan Jr., Vladimir Formanek, Amanda A. Fox, John A. Fox, Gyorgy Frendl, Tanja S. Frey, Samuel M. Galvagno Jr., Edward R. Garcia, Jonathan D. Gates, Cosmin Gauran, Brian J. Gelfand, Simon Gelman, Alexander C. Gerhart, Peter Gerner, Omid Ghalambor, Christopher J. Gilligan, Christian D. Gonzalez, Noah E. Gordon, William B. Gormley, Thomas J. Graetz, Wendy L. Gross, Amit Gupta, James P. Hardy, Seetharaman Hariharan, Miriam Harnett, Philip M. Hartigan, Joaquim M. Havens, Bishr Haydar, Stephen O. Heard, James L. Helstrom, David L. Hepner, McCallum R. Hoyt, Robert N. Jamison, Karinne Jervis, Stephanie B. Jones, Swaminathan Karthik, Richard M. Kaufman, Shubjeet Kaur, Lee A. Kearse Jr., John C. Keel, Scott D. Kelley, Albert H. Kim, Amy L. Kim, Grace Y. Kim, Robert J. Klickovich, Robert M. Knapp, Bhavani S. Kodali, Rahul Koka, Alina Lazar, Laura H. Leduc, Stanley Leeson, Lisa R. Leffert, Scott A. LeGrand, Patricio Leyton, J. Lance Lichtor, John Lin, Alvaro A. Macias, Karan Madan, Sohail K. Mahboobi, Devi Mahendran, Christine Mai, Sayeed Malek, S. Rao Mallampati, Thomas J. Mancuso, Ramon Martin, Matthew C. Martinez, J. A. Jeevendra Martyn, Kai Matthes, Tommaso Mauri, Mary Ellen McCann, Shannon S. McKenna, Dennis J. McNicholl, Abdel-Kader Mehio, Thor C. Milland, Tonya L. K. Miller, John D. Mitchell, K. Annette Mizuguchi, Naila Moghul, David R. Moss, Ross J. Musumeci, Naveen Nathan, Ju-Mei Ng, Liem C. Nguyen, Ervant Nishanian, Martina Nowak, Ala Nozari, Michael Nurok, Arti Ori, Rafael A. Ortega, Amy J. Ortman, David Oxman, Arvind Palanisamy, Carlo Pancaro, Lisbeth Lopez Pappas, Benjamin Parish, Samuel Park, Deborah S. Pederson, Beverly K. Philip, James H. Philip, Silvia Pivi, Stephen D. Pratt, Douglas E. Raines, Stephen L. Ratcliff, James P. Rathmell, J. Taylor Reed, Elizabeth M. Rickerson, Selwyn O. Rogers Jr., Thomas M. Romanelli, William H. Rosenblatt, Carl E. Rosow, Edgar L. Ross, J. Victor Ryckman, Mônica M. Sá Rêgo, Nicholas Sadovnikoff, Warren S. Sandberg, Annette Y. Schure, B. Scott Segal, Navil F. Sethna, Swapneel K. Shah, Shaheen F. Shaikh, Fred E. Shapiro, Torin D. Shear, Prem S. Shekar, Stanton K. Shernan, Naomi Shimizu, Douglas C. Shook, Kamal K. Sikka, Pankaj K. Sikka, David A. Silver, Jeffrey H. Silverstein, Emily A. Singer, Ken Solt, Spiro G. Spanakis, Wolfgang Steudel, Matthias Stopfkuchen-Evans, Michael P. Storey, Gary R. Strichartz, Balachundhar Subramaniam, Wariya Sukhupragarn, John Summers, Shine Sun, Eswar Sundar, Sugantha Sundar, Neelakantan Sunder, Faraz Syed, Usha B. Tedrow, Nelson L. Thaemert, George P. Topulos, Lawrence C. Tsen, Richard D. Urman, Charles A. Vacanti, Francis X. Vacanti, Joshua C. Vacanti, Assia Valovska, Ivan T. Valovski, Mary Ann Vann, Susan Vassallo, Anasuya Vasudevan, Kamen V. Vlassakov, Gian Paolo Volpato, Essi M. Vulli, J. Matthias Walz, Jingping Wang, James F. Watkins, Maxwell Weinmann, Sharon L. Wetherall, Mallory Williams, Sarah H. Wiser, Zhiling Xiong, Warren M. Zapol, Jie Zhou
- Edited by Charles Vacanti, Scott Segal, Pankaj Sikka, Richard Urman
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- Book:
- Essential Clinical Anesthesia
- Published online:
- 05 January 2012
- Print publication:
- 11 July 2011, pp xv-xxviii
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Contributors
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- By Basem Abdelmalak, Joseph Abdelmalak, Alaa A. Abd-Elsayed, David L. Adams, Eric E. Adelman, Maged Argalious, Endrit Bala, Gene H. Barnett, Sheron Beltran, Andrew Bielaczyc, William Bingaman, James M. Blum, Alina Bodas, Vera Borzova, Richard Bowers, Adam Brown, Chad M. Brummett, Alexandra S. Bullough, James F. Burke, Juan P. Cata, Neeraj Chaudhary, Michael J. Claybon, Miguel Cruz, Milind Deogaonkar, Vikram Dhawan, Thomas Didier, D. John Doyle, Zeyd Ebrahim, Hesham Elsharkawy, Wael Ali Sakr Esa, Ehab Farag, Ryen D. Fons, Joseph J. Gemmete, Matt Giles, Phil Gillen, Goodarz Golmirzaie, Marcos Gomes, Lisa Grilly, Maged Guirguis, David W. Healy, Heather Hervey-Jumper, Shawn L. Hervey-Jumper, Paul E. Hilliard, Samuel A. Irefin, George K. Istaphanous, Teresa L. Jacobs, Ellen Janke, Greta Jo, James W. Jones, Rami Karroum, Allen Keebler, Stephen J. Kimatian, Colleen G. Koch, Robert Scott Kriss, Andrea Kurz, Jia Lin, Michael D. Maile, Negmeldeen F. Mamoun, Mariel Manlapaz, Edward Manno, Donn Marciniak, Piyush Mathur, Nicholas F. Marko, Matthew Martin, George A. Mashour, Marco Maurtua, Scott T. McCardle, Julie McClelland, Uma Menon, Paul S. Moor, Laurel E. Moore, Ruairi Moulding, Dileep R. Nair, Todd Nelson, Julie Niezgoda, Edward Noguera, Jerome O’Hara, Aditya S. Pandey, Mauricio Perilla, Paul Picton, Marc J. Popovich, J. Javier Provencio, Venkatakrishna Rajajee, Mohit Rastogi, Stacy Ritzman, Lauryn R. Rochlen, Leif Saager, Vivek Sabharwal, Oren Sagher, Kenneth Saliba, Milad Sharifpour, Lesli E. Skolarus, Paul Smythe, Wolf H. Stapelfeldt, William R. Stetler, Peter Stiles, Vijay Tarnal, Khoi D. Than, B. Gregory Thompson, Alparslan Turan, Christopher R. Turner, Justin Upp, Sumeet Vadera, Jennifer Vance, Anthony C. Wang, Robert J. Weil, Marnie B. Welch, Karen K. Wilkins, Erin S. Williams, George N. Youssef, Asma Zakaria, Sherif S. Zaky, Andrew Zura
- Edited by George A. Mashour, Ehab Farag
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- Book:
- Case Studies in Neuroanesthesia and Neurocritical Care
- Published online:
- 03 May 2011
- Print publication:
- 03 February 2011, pp x-xvi
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Effects of a concentrate supplement on the intake and digestion of a low-quality forage by lambs
- P. T. Doyle, H. Dove, M. Freer, F. J. Hart, R. M. Dixon, A. R. Egan
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- Journal:
- The Journal of Agricultural Science / Volume 111 / Issue 3 / December 1988
- Published online by Cambridge University Press:
- 27 March 2009, pp. 503-511
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Weaned lambs of mean weight 25 kg were offered a diet of mature oaten hay or hay supplemented with a pelleted mixture of oat grain and sunflower meal (2:1), at one of three rates, for 86 days. The effect of the supplement on the voluntary intake of hay was measured during the first 20 days when feed was offered twice daily (Expt 1), after which the effects on ruminal and post-ruminal digestion were investigated under continuous feeding conditions (Expt 2).
In Expt 1 the first increment of supplement increased the total intake of organic matter (OM) but increasing the supplement further, up to 510 g D.M., had no additional effect. The voluntary intake of oaten hay was not significantly reduced by the lowest rate of supplementation but at higher rates was depressed at a mean rate of 92 g/100 g supplement. Rates of change in fasted weight on the four treatments were —63, —5, 21 and 45 g/day, respectively.
In Expt 2, where the rates of hay intake were held at 85% of those achieved in Expt 1, the first increment of supplement increased the pool size of OM and cell wall components in the reticulorumen by about 50%. It also increased their outflow rates at the abomasum by 24% and 33%, respectively, but significantly decreased the fractional outflow rate and fractional digestion rate of cell wall components. Supplementation decreased the proportion of apparent OM digestion that occurred in the reticulo-rumen from 76% to 65%. The presence of supplement doubled the ammonia pool in the rumen and increased the abomasal flow on non-ammonia nitrogen (NAN) and microbial NAN by 70%. Estimates of the amounts of crude protein apparently digested in the intestines (DCPi) increased linearly with proportion of supplement in the diet. However, the apparent digestibility of the hay was decreased, rather than increased, by the supplement. Although higher rates of supplement did not significantly change the elevated rumen pools of OM and cell wall components, there was a consistent tendency for these to decrease.
The results are consistent with the view that the intake of unsupplemented hay was limited by its low nitrogen content and the intake of supplemented hay may have been limited primarily by the capacity of the reticulo-rumen, although other factors were increasingly involved at higher rates of supplementation.
Nonlinear Hall MHD and electrostatic ion–cyclotron stationary waves: a Hamiltonian-geometric viewpoint
- J. F. McKENZIE, R. L. MACE, T. B. DOYLE
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- Journal:
- Journal of Plasma Physics / Volume 73 / Issue 5 / October 2007
- Published online by Cambridge University Press:
- 01 October 2007, pp. 687-700
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Some supplementary results and interpretations on the theory of Hall MHD solitons (McKenzie and Doyle 2002 Phys. Plasmas9, 55) are presented. It is shown that the Hall MHD soliton reduces, in the appropriate limit, to an electrostatic ion–cyclotron soliton. It is also shown how the dynamical equations governing the Hall MHD soliton can be obtained from a Hamiltonian H. Soliton solutions correspond to H = 0, periodic solutions to H < 0 and rotation-type solutions to H >0. Possible applications are discussed. A non-canonical Hamiltonian picture is developed and compared to the well-known example of a free rigid body.
Compressive and rarefactive ion-acoustic solitons in a two component electron plasma
- J. F. McKENZIE, T. B. DOYLE, M. A. HELLBERG, F. VERHEEST
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- Journal:
- Journal of Plasma Physics / Volume 71 / Issue 2 / April 2005
- Published online by Cambridge University Press:
- 07 February 2005, pp. 163-176
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In this paper an analysis is given for the conditions under which compressive and rarefactive ion-acoustic solitons may exist in a plasma containing two electron populations, one hot and the other cool. Compressive solitons exist in the collective Mach number range $1\,{<}\,M\,{<}\,M_{\rm c}$, which, for a given abundance ratio of the cool population, translates into an annular region in the ion-acoustic Mach numbers space. The upper limit $M_{\rm c}$ corresponds to a degenerate sonic point for the protons in which they tend to an infinite compression and are brought to rest at the wave centre. To form a charge neutral point in the rarefactive regime (a prerequisite to the existence of rarefactive solitons) it is necessary that the ‘scale height’ of the hot electrons be sufficiently large that their number density, which is nearly constant, approximately balances that of the protons, before the cool electrons experience their ‘atmospheric lid’. Furthermore, a sufficient condition for the existence of rarefactive solitons is found by requiring a solution to the wave structure equation at the ‘lid’. The case of very hot electrons (highly sub-ion-acoustic) is considered, and various parameter regimes in which compressive and rarefactive solitons exist are evaluated in this super-hot electron approximation, both for the polytropic case, $\gamma \neq 1$, and the isothermal case, $\gamma = 1$. This approximation is formally equivalent to the problem of a bi-ion plasma, including a super-massive negative species.
The application of the constants of motion to nonlinear stationary waves in complex plasmas: a unified fluid dynamic viewpoint
- J. F. McKENZIE, E. DUBININ, K. SAUER, T. B. DOYLE
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- Journal:
- Journal of Plasma Physics / Volume 70 / Issue 4 / August 2004
- Published online by Cambridge University Press:
- 27 July 2004, pp. 431-462
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Perturbation reductive procedures, as used to analyse various weakly nonlinear plasma waves (solitons and periodic waves), normally lead to the dynamical system being described by KdV, Burgers' or a nonlinear Schrödinger-type equation, with properties that can be deduced from an array of mathematical techniques. Here we develop a fully nonlinear theory of one-dimensional stationary plasma waves, which elucidates the common nature of various diverse wave phenomena. This is accomplished by adopting an essentially fluid dynamic viewpoint. In this unified treatment the constants of the motion (for mass, momentum and energy) lead naturally to the construction of the wave structure equations. It is shown, for example, that electrostatic, Hall–magnetohydrodynamic and ion–cyclotron–acoustic nonlinear waves all obey first-order differential equations of the same generic type for the longitudinal flow field of the wave. The equilibrium points, which define the soliton amplitude, are given by the compressive and/or rarefactive roots of a total plasma ‘energy’ or ‘momentum’ function characterizing the wave type. This energy function, which is an algebraic combination of the Bernoulli momentum and energy functions for the longitudinal flow field, is the fluid dynamic counterpart of the pseudo-potentials, which are characteristic of system structure equations formulated in other than fluid variables. Another general feature of the structure equation is the phenomenon of choked flow, which occurs when the flow speed becomes sonic. It is this trans-sonic property that limits the soliton amplitudes and defines the critical collective Mach numbers of the waves. These features are also obtained in multi-component plasmas where, for example, in a bi-ion plasma, momentum exchanges between protons and heavier ions are mediated by the Maxwell magnetic stresses. With a suitable generalization of the concept of a sonic point in a bi-ion system and the corresponding choked flow feature, the wave structures, although now more complicated, can also be understood within this overall fluid framework. Particularly useful tools in this context are the momentum hodograph (an algebraic relation between the bi-ion speeds and the electron speed, or magnetic field, which follows from the conservation of mass, momentum and charge-neutrality) and a generalized Bernoulli energy density for each species. Analysis shows that the bi-ion solitons are essentially compressive, but contain the remarkable feature of the presence of a proton rarefactive core. A new type of soliton, called an ‘oscilliton’ because embedded spatial oscillations are superimposed on the classical soliton, is also described and discussed. A necessary condition for the existence of this type of wave is that the linear phase velocity must exhibit an extremum where the phase speed matches the group speed. The remarkable properties of this wave are illustrated for the case of both whistler waves and bi-ion waves where, for the latter, the requisite condition is met near the cross-over frequencies. In the case of the whistler oscilliton, which propagates at speeds in excess of one half of the Alfvén speed (based on the electrons), an analytic solution has been constructed through a phase-portrait integral of the system in which the proton and electron dynamics must be placed on the same footing. The relevance of the different wave structures to diverse space environments is briefly discussed in relation to recently available high-time and spatial resolution data from satellite observations.
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