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214 results on '"Richardson, Martin P."'

2. Broadband space-time wave packets propagating 70 m

Author

Bhaduri, Basanta, Yessenov, Murat, Reyes, Danielle, Pena, Jessica, Meem, Monjurul, Fairchild, Shermineh Rostami, Menon, Rajesh, Richardson, Martin, and Abouraddy, Ayman F.

Subjects
Physics - Optics
Abstract

The propagation distance of a pulsed beam in free space is ultimately limited by diffraction and space-time coupling. "Space-time" (ST) wave packets are pulsed beams endowed with tight spatio-temporal spectral correlations that render them propagation-invariant. Here we explore the limits of the propagation distance for ST wave packets. Making use of a specially designed phase plate inscribed by gray-scale lithography, we synthesize an ST light sheet of width $\approx700$~$\mu$m and bandwidth $\sim20$~nm and confirm a propagation distance of $\approx70$~m.

Published
2019
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4. Thermodynamic basis for the demarcation of Arctic and alpine treelines

Author

Meredith Richardson Martin, Praveen Kumar, Oliver Sonnentag, and Philip Marsh

Subjects
Medicine, Science
Abstract

Abstract At the edge of alpine and Arctic ecosystems all over the world, a transition zone exists beyond which it is either infeasible or unfavorable for trees to exist, colloquially identified as the treeline. We explore the possibility of a thermodynamic basis behind this demarcation in vegetation by considering ecosystems as open systems driven by thermodynamic advantage—defined by vegetation’s ability to dissipate heat from the earth’s surface to the air above the canopy. To deduce whether forests would be more thermodynamically advantageous than existing ecosystems beyond treelines, we construct and examine counterfactual scenarios in which trees exist beyond a treeline instead of the existing alpine meadow or Arctic tundra. Meteorological data from the Italian Alps, United States Rocky Mountains, and Western Canadian Taiga-Tundra are used as forcing for model computation of ecosystem work and temperature gradients at sites on both sides of each treeline with and without trees. Model results indicate that the alpine sites do not support trees beyond the treeline, as their presence would result in excessive CO $$_2$$ 2 loss and extended periods of snowpack due to temperature inversions (i.e., positive temperature gradient from the earth surface to the atmosphere). Further, both Arctic and alpine sites exhibit negative work resulting in positive feedback between vegetation heat dissipation and temperature gradient, thereby extending the duration of temperature inversions. These conditions demonstrate thermodynamic infeasibility associated with the counterfactual scenario of trees existing beyond a treeline. Thus, we conclude that, in addition to resource constraints, a treeline is an outcome of an ecosystem’s ability to self-organize towards the most advantageous vegetation structure facilitated by thermodynamic feasibility.

Published
2022
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6. Free-Space Nonlinear Beam Combining Towards Filamentation

Author

Rostami, Shermineh, Walasik, Wiktor, Kepler, Daniel, Baudelet, Matthieu, Litchinitser, Natalia M., and Richardson, Martin

Subjects
Physics - Optics
Abstract

Multi-filamentation opens new degrees of freedom for manipulating electromagnetic waves in air. However, without control, multiple filament interactions, including attraction, repulsion or fusion often result in formation of complex disordered filament distributions. Moreover, high power beams conventionally used in multi-filament formation experiments often cause significant surface damage. The growing number of applications for laser filaments requires fine control of their formation and propagation. We demonstrate, experimentally and theoretically, that the attraction and fusion of ultrashort beams with initial powers below the critical value enable the eventual formation of a filament downstream. Filament formation is delayed to a predetermined distance in space, avoiding optical damage to external beam optics while still enabling robust filaments with controllable properties as if formed from a single high power beam. This paradigm introduces new opportunities for filament engineering eliminating the need to use high peak power lasers sources., Comment: 16 pages, 5 figures

Published
2016

7. Dramatic enhancement of supercontinuum generation in elliptically-polarized laser filaments

Author

Rostami, Shermineh, Chini, Michael, Lim, Khan, Palastro, John P., Durand, Magali, Diels, Jean-Claude, Arissian, Ladan, Baudelet, Matthieu, and Richardson, Martin

Subjects
Physics - Optics
Abstract

Broadband laser sources based on supercontinuum generation by femtosecond laser filamentation have enabled applications from stand-off sensing and spectroscopy to the generation and self-compression of high-energy few-cycle pulses. Filamentation relies on the dynamic balance between self-focusing and plasma defocusing, mediated by the Kerr nonlinearity and multiphoton ionization respectively. The filament properties, including the supercontinuum generation, are therefore highly sensitive to the properties of both the laser source and the propagation medium. Here, we report the anomalous spectral broadening of the supercontinuum for filamentation in molecular gases, which is observed for specific elliptical polarization states of the input laser pulse. The resulting spectrum is accompanied by a modification of the supercontinuum polarization state and a lengthening of the filament plasma column. Numerical simulations confirm that the anomalous behavior originates from the delayed rotational response of the medium, demonstrating a new parameter to control supercontinuum generation.

Published
2015

8. The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

Author

LBNE Collaboration, Adams, Corey, Adams, David, Akiri, Tarek, Alion, Tyler, Anderson, Kris, Andreopoulos, Costas, Andrews, Mike, Anghel, Ioana, Anjos, João Carlos Costa dos, Antonello, Maddalena, Arrieta-Diaz, Enrique, Artuso, Marina, Asaadi, Jonathan, Bai, Xinhua, Baibussinov, Bagdat, Baird, Michael, Balantekin, Baha, Baller, Bruce, Baptista, Brian, Barker, D'Ann, Barker, Gary, Barletta, William A., Barr, Giles, Bartoszek, Larry, Bashyal, Amit, Bass, Matt, Bellini, Vincenzo, Benetti, Pietro Angelo, Berger, Bruce E., Bergevin, Marc, Berman, Eileen, Berns, Hans-Gerd, Bernstein, Adam, Bernstein, Robert, Bhandari, Babu, Bhatnagar, Vipin, Bhuyan, Bipul, Bian, Jianming, Bishai, Mary, Blake, Andrew, Blaszczyk, Flor, Blaufuss, Erik, Bleakley, Bruce, Blucher, Edward, Blusk, Steve, Bocean, Virgil, Boffelli, F., Boissevain, Jan, Bolton, Timothy, Bonesini, Maurizio, Boyd, Steve, Brandt, Andrew, Breedon, Richard, Bromberg, Carl, Brown, Ralph, Brunetti, Giullia, Buchanan, Norman, Bugg, Bill, Busenitz, Jerome, Calligarich, E., Camilleri, Leslie, Carminati, Giada, Carr, Rachel, Castromonte, Cesar, Cavanna, Flavio, Centro, Sandro, Chen, Alex, Chen, Hucheng, Chen, Kai, Cherdack, Daniel, Chi, Cheng-Yi, Childress, Sam, Choudhary, Brajesh Chandra, Christodoulou, Georgios, Christofferson, Cabot-Ann, Church, Eric, Cline, David, Coan, Thomas, Cocco, Alfredo, Coelho, Joao, Coleman, Stephen, Conrad, Janet M., Convery, Mark, Corey, Robert, Corwin, Luke, Cranshaw, Jack, Cronin-Hennessy, Daniel, Curioni, A., da Motta, Helio, Davenne, Tristan, Davies, Gavin S., Dazeley, Steven, De, Kaushik, de Gouvea, Andre, de Jong, Jeffrey K., Demuth, David, Densham, Chris, Diwan, Milind, Djurcic, Zelimir, Dolfini, R., Dolph, Jeffrey, Drake, Gary, Dye, Stephen, Dyuang, Hongue, Edmunds, Daniel, Elliott, Steven, Elnimr, Muhammad, Eno, Sarah, Enomoto, Sanshiro, Escobar, Carlos O., Evans, Justin, Falcone, A., Falk, Lisa, Farbin, Amir, Farnese, Christian, Fava, Angela, Felde, John, Fernandes, S., Ferroni, Fernando, Feyzi, Farshid, Fields, Laura, Finch, Alex, Fitton, Mike, Fleming, Bonnie, Fowler, Jack, Fox, Walt, Friedland, Alex, Fuess, Stu, Fujikawa, Brian, Gallagher, Hugh, Gandhi, Raj, Garvey, Gerald, Gehman, Victor M., de Geronimo, Gianluigi, Gibin, Daniele, Gill, Ronald, Gomes, Ricardo A., Goodman, Maury C., Goon, Jason, Graf, Nicholas, Graham, Mathew, Gran, Rik, Grant, Christopher, Grant, Nick, Greenlee, Herbert, Greenler, Leland, Grullon, Sean, Guardincerri, Elena, Guarino, Victor, Guarnaccia, Evan, Guedes, Germano, Guenette, Roxanne, Guglielmi, Alberto, Guzzo, Marcelo M., Habig, Alec T., Hackenburg, Robert W., Hadavand, Haleh, Hahn, Alan, Haigh, Martin, Haines, Todd, Handler, Thomas, Hans, Sunej, Hartnell, Jeff, Harton, John, Hatcher, Robert, Hatzikoutelis, Athans, Hays, Steven, Hazen, Eric, Headley, Mike, Heavey, Anne, Heeger, Karsten, Heise, Jaret, Hellauer, Robert, Hewes, V, Himmel, Alexander, Hogan, Matthew, Holanda, Pedro, Holin, Anna, Horton-Smith, Glenn, Howell, Joe, Hurh, Patrick, Huston, Joey, Hylen, James, Imlay, Richard, Insler, Jonathan, Introzzi, G., Isvan, Zeynep, Jackson, Chris, Jacobsen, John, Jaffe, David E., James, Cat, Jen, Chun-Min, Johnson, Marvin, Johnson, Randy, Johnson, Robert, Johnson, Scott, Johnston, William, Johnstone, John, Jones, Ben J. P., Jostlein, H., Junk, Thomas, Kadel, Richard, Kaess, Karl, Karagiorgi, Georgia, Kaspar, Jarek, Katori, Teppei, Kayser, Boris, Kearns, Edward, Keener, Paul, Kemp, Ernesto, Kettell, Steve H., Kirby, Mike, Klein, Joshua, Koizumi, Gordon, Kopp, Sacha, Kormos, Laura, Kropp, William, Kudryavtsev, Vitaly A., Kumar, Ashok, Kumar, Jason, Kutter, Thomas, La Zia, Franco, Lande, Kenneth, Lane, Charles, Lang, Karol, Lanni, Francesco, Lanza, Richard, Latorre, Tony, Learned, John, Lee, David, Lee, Kevin, Li, Qizhong, Li, Shaorui, Li, Yichen, Li, Zepeng, Libo, Jiang, Linden, Steve, Ling, Jiajie, Link, Jonathan, Littenberg, Laurence, Liu, Hu, Liu, Qiuguang, Liu, Tiankuan, Losecco, John, Louis, William, Lundberg, Byron, Lundin, Tracy, Lundy, Jay, Machado, Ana Amelia, Maesano, Cara, Magill, Steve, Mahler, George, Malon, David, Malys, Stephen, Mammoliti, Francesco, Mandal, Samit Kumar, Mann, Anthony, Mantsch, Paul, Marchionni, Alberto, Marciano, William, Mariani, Camillo, Maricic, Jelena, Marino, Alysia, Marshak, Marvin, Marshall, John, Matsuno, Shiegenobu, Mauger, Christopher, Mavrokoridis, Konstantinos, Mayer, Nate, McCauley, Neil, McCluskey, Elaine, McDonald, Kirk, McFarland, Kevin, McKee, David, McKeown, Robert, McTaggart, Robert, Mehdiyev, Rashid, Mei, Dongming, Menegolli, A., Meng, Guang, Meng, Yixiong, Mertins, David, Messier, Mark, Metcalf, William, Milincic, Radovan, Miller, William, Mills, Geoff, Mishra, Sanjib R., Mokhov, Nikolai, Montanari, Claudio, Montanari, David, Moore, Craig, Morfin, Jorge, Morgan, Ben, Morse, William, Moss, Zander, Moura, Célio A., Mufson, Stuart, Muller, David, Musser, Jim, Naples, Donna, Napolitano, Jim, Newcomer, Mitch, Nichol, Ryan, Nicholls, Tim, Niner, Evan, Norris, Barry, Nowak, Jaroslaw, O'Keeffe, Helen, Oliveira, Roberto, Olson, Travis, Page, Brian, Pakvasa, Sandip, Palamara, Ornella, Paley, Jon, Paolone, Vittorio, Papadimitriou, Vaia, Park, Seongtae, Parsa, Zohreh, Partyka, Kinga, Paulos, Bob, Pavlovic, Zarko, Peeters, Simon, Perch, Andy, Perkin, Jon D., Petti, Roberto, Petukhov, Andre, Pietropaolo, Francesco, Plunkett, Robert, Polly, Chris, Pordes, Stephen, Potekhin, Maxim, Potenza, Renato, Prakash, Arati, Prokofiev, Oleg, Qian, Xin, Raaf, Jennifer L., Radeka, Veljko, Rakhno, Igor, Ramachers, Yorck, Rameika, Regina, Ramsey, John, Rappoldi, A., Raselli, G. L., Ratoff, Peter, Ravindra, Shreyas, Rebel, Brian, Reichenbacher, Juergen, Reitzner, Dianne, Rescia, Sergio, Richardson, Martin, Rielage, Kieth, Riesselmann, Kurt, Robinson, Matt, Rochester, Leon, Ronquest, Michael, Rosen, Marc, Rossella, M., Rubbia, Carlo, Rucinski, Russ, Sahijpal, Sandeep, Sahoo, Himansu, Sala, Paola, Salmiera, Delia, Samios, Nicholas, Sanchez, Mayly, Scaramelli, Alberto, Schellman, Heidi, Schmitt, Richard, Schmitz, David, Schneps, Jack, Scholberg, Kate, Segreto, Ettore, Seibert, Stanley, Sexton-Kennedy, Liz, Shaevitz, Mike, Shanahan, Peter, Sharma, Rahul, Shaw, Terri, Simos, Nikolaos, Singh, Venktesh, Sinnis, Gus, Sippach, William, Skwarnicki, Tomasz, Smy, Michael, Sobel, Henry, Soderberg, Mitch, Sondericker, John, Sondheim, Walter, Sousa, Alexandre, Spooner, Neil J. C., Stancari, Michelle, Stancu, Ion, Stefan, Dorota, Stefanik, Andy, Stewart, James, Stone, Sheldon, Strait, James, Strait, Matthew, Striganov, Sergei, Sullivan, Gregory, Sun, Yujing, Suter, Louise, Svenson, Andrew, Svoboda, Robert, Szczerbinska, Barbara, Szelc, Andrzej, Szydagis, Matthew, Söldner-Rembold, Stefan, Talaga, Richard, Tamsett, Matthew, Tariq, Salman, Tayloe, Rex, Taylor, Charles, Taylor, David, Teymourian, Artin, Themann, Harry, Thiesse, Matthew, Thomas, Jenny, Thompson, Lee F., Thomson, Mark, Thorn, Craig, Thorpe, Matt, Tian, Xinchun, Tiedt, Doug, Toki, Walter, Tolich, Nikolai, Torti, M., Toups, Matt, Touramanis, Christos, Tripathi, Mani, Tropin, Igor, Tsai, Yun-Tse, Tull, Craig, Tzanov, Martin, Urheim, Jon, Usman, Shawn, Vagins, Mark, Valdiviesso, Gustavo, Van Berg, Rick, Van de Water, Richard, Van Gemmeren, Peter, Varanini, Filippo, Varner, Gary, Vaziri, Kamran, Velev, Gueorgui, Ventura, Sandro, Vignoli, Chiara, Viren, Brett, Wahl, Dan, Waldron, Abby, Walter, Christopher W., Wang, Hanguo, Wang, Wei, Warburton, Karl, Warner, David, Wasserman, Ryan, Watson, Blake, Weber, Alfons, Wei, Wenzhao, Wells, Douglas, Wetstein, Matthew, White, Andy, White, Hywel, Whitehead, Lisa, Whittington, Denver, Willhite, Joshua, Wilson, Robert J., Winslow, Lindley, Wood, Kevin, Worcester, Elizabeth, Worcester, Matthew, Xin, Tian, Yarritu, Kevin, Ye, Jingbo, Yeh, Minfang, Yu, Bo, Yu, Jae, Yuan, Tianlu, Zani, A., Zeller, Geralyn P., Zhang, Chao, Zimmerman, Eric D., and Zwaska, Robert

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Accelerator Physics, Physics - Instrumentation and Detectors
Abstract

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess., Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figures

Published
2013

29. Otoacoustic emissions as a screening test for hearing impairment in children recovering from acute bacterial meningitis

Author

Richardson, Martin P., Williamson, Timothy J., Reid, Andrew, Tarlow, Michael J., and Rudd, Peter T.

Subjects
Audiometry -- Methods, Hearing disorders in children -- Diagnosis, Bacterial meningitis -- Complications and side effects, Bacterial meningitis -- Patient outcomes
Abstract

ABSTRACT. Objectives. To study the efficacy of otoacoustic emissions (OAEs) as a screening test for hearing impairment in children with acute bacterial meningitis. Hearing tests were performed before discharge from [...]

Published
1998

31. Femtosecond Generation of Nano-Fibers

Author

Richardson Martin, Ramme Mark, Royon Arnaud, Cardinal Thierry, and Canioni Lionel

Subjects
Engineering (General). Civil engineering (General), TA1-2040
Abstract

A new approach to making extremely large aspect ratio glass nano-fibers with diameters typically 20 – 40 nm is described. The fabrication process utilizes a novel phenomenon occurring with the interaction of focused high power femtosecond laser radiation with transparent media.

Published
2013
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33. Femtosecond Laser Post-Processing of Metal Parts Produced by Laser Additive Manufacturing

Author

Mingareev Ilya, Bonhoff Tobias, El-Sherif Ashraf F., and Richardson Martin

Subjects
Engineering (General). Civil engineering (General), TA1-2040
Abstract

High-repetition rate femtosecond laser radiation was utilized to improve surface quality of metal parts manufactured by laser additive techniques. This novel approach can be used to postprocess parts made of heat-sensitive materials, and to attain the designed net shape with micrometer precision.

Published
2013
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35. Sonic anemometer data processing for comparison to optical turbulence theory and simulation

Author

Coffaro, Joseph, Richardson, Martin, Bernath, Robert, and Crabbs, Robert

Abstract

With appropriate processing techniques, sonic anemometry can provide useful insights into the strength and spectral shape of optical turbulence. Closed form propagation models and simulations require stationary optical turbulence statistics to make a meaningful comparison with experimental results. This work presents a new approach for examining the stationarity of data provided by sonic anemometry and by fitting optical turbulence parameters. Von Kármán, Greenwood–Tarazano, and one minus exponential spectral models are fitted to experimental data. Each model fit is evaluated using information criteria. The Greenwood–Tarazano model is shown to provide the best fit to experimental data. Optical turbulence parameters from the Greenwood–Tarazano model are compared with results from instruments at varying heights above the ground.

Published
2022

37. Shockwave enhancement from temporally separated filaments interacting with a water droplet

Author

Peña, Jessica, Kerrigan, Haley, and Richardson, Martin

Abstract

Many applications of filamentation require propagation through aerosol-dense environments. The shockwave produced from a filament–droplet interaction is one mechanism of clearing a path through a dense cloud of aerosols. Here, we show an enhanced shockwave resulting from the interaction of two temporally separated filaments with a single water droplet. The expanding shockwave is imaged with an ultrafast shadowgraphy technique, and Sedov–Taylor analysis determines the energy coupled into the shockwave. For an optimal temporal spacing between the filaments of 400 ps, the shockwave energy increased by 3 times and its radius increased by 1.23 times compared to the shockwave generated by the interaction of a droplet with a single filament.

Published
2021

38. The SANAD II study of the effectiveness and cost-effectiveness of levetiracetam, zonisamide, or lamotrigine for newly diagnosed focal epilepsy: an open-label, non-inferiority, multicentre, phase 4, randomised controlled trial

Author

Marson, Anthony, Burnside, Girvan, Appleton, Richard, Smith, Dave, Leach, John Paul, Sills, Graeme, Tudur-Smith, Catrin, Plumpton, Catrin, Hughes, Dyfrig A, Williamson, Paula, Baker, Gus A, Balabanova, Silviya, Taylor, Claire, Brown, Richard, Hindley, Dan, Howell, Stephen, Maguire, Melissa, Mohanraj, Rajiv, Smith, Philip E, Lanyon, Karen, Manford, Mark, Chitre, Manali, Parker, Alasdair, Swiderska, Nina, Appleton, Richard, Pauling, James, Hughes, Adrian, Gupta, Rajat, Hanif, Sadia, Awadh, Mostafa, Ragunathan, Sharmini, Cable, Nicola, Cooper, Paul, Hindley, Daniel, Rakshi, Karl, Molloy, Sophie, Reuber, Markus, Ayonrinde, Kunle, Wilson, Martin, Saladi, Satyanarayana, Gibb, John, Funston, Lesley-Ann, Cassidy, Damhait, Boyd, Jonathan, Ratnayaka, Mal, Faza, Hani, Sadler, Martin, Al-Moasseb, Hassan, Galtrey, Clare, Wren, Damien, Olabi, Anas, Fuller, Geraint, Khan, Muhammed, Kallappa, Chetana, Chinthapalli, Ravi, Aji, Baba, Davies, Rhys, Foster, Kathryn, Hitiris, Nikolas, Maguire, Melissa, Hussain, Nahin, Dowson, Simon, Ellison, Julie, Sharrack, Basil, Gandhi, Vandna, Powell, Rob, Tittensor, Phil, Summers, Beatrice, Shashikiran, Sastry, Dison, Penelope J, Samarasekera, Shanika, McCorry, Doug, White, Kathleen, Nithi, Kannan, Richardson, Martin, Brown, Richard, Page, Rupert, Deekollu, David, Slaght, Sean, Warriner, Stephen, Ahmed, Mansoor, Chaudhuri, Abhijit, Chow, Gabriel, Artal, Javier, Kucinskiene, Danute, Sreenivasa, Harish, Velmurugan, Singara, Zipitis, Christos S, McLean, Brendan, Lal, Vaithianathar, Gregoriou, Angelous, Maddison, Paul, Pickersgill, Trevor, Anderson, Joseph, Lawthom, Charlotte, Howell, Stephen, Whitlingum, Gabriel, Rakowicz, Wojtek, Kinton, Lucy, McLellan, Alisa, Vora, Nitish, Zuberi, Sameer, Kelso, Andrew, Hughes, Imelda, Martland, John, Emsley, Hedley, de Goede, Christian, Singh, RP, Moor, Carl-Christian, Aram, Julia, Mohanraj, Rajiv, Sakthivel, Kumar, Nelapatla, Suresh, Rittey, Chris, Pinto, Ashwin, Leach, John Paul, Cock, Hannah, Richardson, Anna, Houston, Erika, Cooper, Christopher, Lawson, Geoff, Massarano, Albert, Burness, Christine, Marson, Anthony, Smith, Dave, Wieshmann, Udo, Dey, Indranil, Sivakumar, Puthuval, Yeung, Lap-Kong, Smith, Philip, Bentur, Hemalata, Heafield, Tom, Mathew, Anna, Smith, David, and Jauhari, Praveen

Abstract

Levetiracetam and zonisamide are licensed as monotherapy for patients with focal epilepsy, but there is uncertainty as to whether they should be recommended as first-line treatments because of insufficient evidence of clinical effectiveness and cost-effectiveness. We aimed to assess the long-term clinical effectiveness and cost-effectiveness of levetiracetam and zonisamide compared with lamotrigine in people with newly diagnosed focal epilepsy.

Published
2021
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39. The SANAD II study of the effectiveness and cost-effectiveness of valproate versus levetiracetam for newly diagnosed generalised and unclassifiable epilepsy: an open-label, non-inferiority, multicentre, phase 4, randomised controlled trial

Author

Marson, Anthony, Burnside, Girvan, Appleton, Richard, Smith, Dave, Leach, John Paul, Sills, Graeme, Tudur-Smith, Catrin, Plumpton, Catrin, Hughes, Dyfrig A, Williamson, Paula, Baker, Gus A, Balabanova, Silviya, Taylor, Claire, Brown, Richard, Hindley, Dan, Howell, Stephen, Maguire, Melissa, Mohanraj, Rajiv, Smith, Philip E, Lanyon, Karen, Manford, Mark, Chitre, Manali, Parker, Alasdair, Swiderska, Nina, Appleton, Richard, Pauling, James, Hughes, Adrian, Gupta, Rajat, Hanif, Sadia, Awadh, Mostafa, Ragunathan, Sharmini, Cable, Nicola, Cooper, Paul, Hindley, Daniel, Rakshi, Karl, Molloy, Sophie, Reuber, Markus, Ayonrinde, Kunle, Wilson, Martin, Saladi, Satyanarayana, Gibb, John, Funston, Lesley-Ann, Cassidy, Damhait, Boyd, Jonathan, Ratnayaka, Mal, Faza, Hani, Sadler, Martin, Al-Moasseb, Hassan, Galtrey, Clare, Wren, Damien, Olabi, Anas, Fuller, Geraint, Khan, Muhammed, Kallappa, Chetana, Chinthapalli, Ravi, Aji, Baba, Davies, Rhys, Foster, Kathryn, Hitiris, Nikolas, Maguire, Melissa, Hussain, Nahin, Dowson, Simon, Ellison, Julie, Sharrack, Basil, Gandhi, Vandna, Powell, Rob, Tittensor, Phil, Summers, Beatrice, Shashikiran, Sastry, Dison, Penelope J, Samarasekera, Shanika, McCorry, Doug, White, Kathleen, Nithi, Kannan, Richardson, Martin, Brown, Richard, Page, Rupert, Deekollu, David, Slaght, Sean, Warriner, Stephen, Ahmed, Mansoor, Chaudhuri, Abhijit, Chow, Gabriel, Artal, Javier, Kucinskiene, Danute, Sreenivasa, Harish, Velmurugan, Singara, Zipitis, Christos S, McLean, Brendan, Lal, Vaithianathar, Gregoriou, Angelous, Maddison, Paul, Pickersgill, Trevor, Anderson, Joseph, Lawthom, Charlotte, Howell, Stephen, Whitlingum, Gabriel, Rakowicz, Wojtek, Kinton, Lucy, McLellan, Alisa, Vora, Nitish, Zuberi, Sameer, Kelso, Andrew, Hughes, Imelda, Martland, John, Emsley, Hedley, de Goede, Christian, Singh, RP, Moor, Carl-Christian, Aram, Julia, Mohanraj, Rajiv, Sakthivel, Kumar, Nelapatla, Suresh, Rittey, Chris, Pinto, Ashwin, Leach, John Paul, Cock, Hannah, Richardson, Anna, Houston, Erika, Cooper, Christopher, Lawson, Geoff, Massarano, Albert, Burness, Christine, Marson, Anthony, Smith, Dave, Wieshmann, Udo, Dey, Indranil, Sivakumar, Puthuval, Yeung, Lap-Kong, Smith, Philip, Bentur, Hemalata, Heafield, Tom, Mathew, Anna, Smith, David, and Jauhari, Praveen

Abstract

Valproate is a first-line treatment for patients with newly diagnosed idiopathic generalised or difficult to classify epilepsy, but not for women of child-bearing potential because of teratogenicity. Levetiracetam is increasingly prescribed for these patient populations despite scarcity of evidence of clinical effectiveness or cost-effectiveness. We aimed to compare the long-term clinical effectiveness and cost-effectiveness of levetiracetam compared with valproate in participants with newly diagnosed generalised or unclassifiable epilepsy.

Published
2021
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41. Effects of dynamic loading on fracture healing under different locking compression plate configurations: A finite element study.

Author

Ghimire, Smriti, Miramini, Saeed, Richardson, Martin, Mendis, Priyan, and Zhang, Lihai

Subjects
DYNAMIC loads, FRACTURE healing, GROWTH factors, BONE cells, MESENCHYMAL stem cells, BONE fractures
Abstract

The design of patient specific weight-bearing exercises after the surgical implementation of internal fixations is of critical importance for bone fracture healing. The purpose of this study is to theoretically investigate the effects of physiologically relevant dynamic loading on early stage of fracture healing under different locking compression plate (LCP) configurations. The finite element results show that dynamic loading enhanced transport of bone cells and growth factors in the fracture callus is much dependent on the flexibility of LCP. In comparison to free diffusion, a relatively flexible LCP together with dynamic loading could significantly enhance solute transport in callus. For example, a flexible LCP achieved by increasing WL (Working Length) and BPD (Bone Plate Distance) (e.g. WL=100 mm and BPD=2 mm) together with a 5-h 150 N@1 Hz dynamic loading could increase the uptake of chondrocytes by around 280% compared to free diffusion, osteoblasts by around 180%, osteogenic growth factors by around 120% and chondrogenic growth factors by around 220%. In addition, dynamic loading enhanced transport of cells and growth factors under LCP is spatially dependent with a relatively higher enhancement in far cortex zone than that in near cortex zone. The outcomes from present study could potentially assist orthopaedic surgeons to determine optimal loading regimes with consideration of patient specific LCP configurations. • Enhanced cell transport under dynamic loading depends on fixation flexibility. • Far cortical zone exhibit higher enhancement of cell uptake than near cortical zone. • Chondrocyte enhancement is higher in relatively smaller gap size of 1 mm. • Higher loading magnitude produce better mesenchymal stem cells enhancement. [ABSTRACT FROM AUTHOR]

Published
2019
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42. Rotator cuff contact pressures at the tendon-implant interface after anatomic total shoulder arthroplasty using a metal-backed glenoid component.

Author

Thomas, Richard, Richardson, Martin, Patel, Minoo, Page, Richard, Sangeux, Morgan, and Ackland, David C.

Abstract

Background Rotator cuff tears following anatomic total shoulder arthroplasty increase with duration of follow-up. This study aimed to evaluate contact pressure between the rotator cuff tendons and prosthesis after anatomic total shoulder arthroplasty and compare these with the tendon-contact pressures in the native shoulder. Methods Eight entire upper extremities were mounted onto a testing apparatus, and simulated muscle loading was applied to each rotator cuff tendon with the shoulder positioned in abduction, internal rotation, and external rotation. Pressure-sensitive film placed between each tendon and bone was used to measure the resultant tendon contact pressures. Experiments were repeated after anatomic total shoulder arthroplasty using standardized implant sizes, and pressure-sensitive film was used to evaluate tendon-prosthesis contact pressure. Results Both joint angle and shoulder joint replacement surgery had significant effects on the maximum contact pressure measured between the humeral head and all rotator cuff tendons (P <.05) except the teres minor. The supraspinatus demonstrated a significantly larger peak tendon contact pressure after surgery at 45° of abduction relative to that in the native shoulder (mean difference, 0.2 MPa; P =.031), while the subscapularis had a significantly larger maximum contact pressure at 10° of abduction (mean difference, 0.45 MPa; P =.032) and 90° of abduction (mean difference, 0.80 MPa; P =.008) postoperatively. Conclusion Anatomic total shoulder arthroplasty results in significantly larger tendon contact pressures relative to those in the native shoulder. High tendon contact pressures may ultimately predispose rotator cuff tendons to postoperative wear-induced damage and tearing. [ABSTRACT FROM AUTHOR]

Published
2018
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43. Building a model for day case hiatal surgery - Lessons learnt over a 10 year period in a high volume unit: A case series.

Author

Mistry, Pritesh, Zaman, Shafquat, Shapey, Iestyn, Daskalakis, Markos, Nijjar, Rajwinder, Richardson, Martin, Super, Paul, and Singhal, Rishi

Abstract

Background: Laparoscopic anti-reflux surgery has become the standard treatment for symptomatic gastro-oesophageal reflux disease refractory to medical therapy. Successful anti-reflux surgery involves safe, minimally invasive surgery, resulting in symptom resolution with minimal side effects. This study aims to assess the feasibility and safety of day case anti-reflux surgery focussing on peri- and post-operative outcomes as a measure of success.Methods: Data was collected from the hospital database from 2003 to 2012. Data collection included demographics, surgeon, mode of admission, length of stay and complications. Electronic records were independently scrutinised for all patients with a length of stay of more than two nights.Results: 723 patients underwent laparoscopic fundoplication ± small hiatus hernia repair (<5 cm) with a day case rate of 67.1%. The 30 day readmission rate in these patients was 2.9% (21/723 patients). Nine patients had a failure of their initial laparoscopic fundoplication (defined as recurrence of symptoms). Three patients required a re-operation within 12 months of their initial procedure (re-operation rate = 0.41% (3/723 patients)).Conclusion: Laparoscopic hiatal surgery can be performed safely as a day case in high volume specialist centres with good outcomes. Raising the national standard for day case fundoplication promotes good practice and should be the model for future commissioning. [ABSTRACT FROM AUTHOR]

Published
2018
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44. Temporal stitching in burst-mode filamentation

Author

Reyes, Danielle, Kerrigan, Haley, Peña, Jessica, Bodnar, Nathan, Bernath, Robert, Richardson, Martin, and Fairchild, Shermineh Rostami

Abstract

The creation of single optical filaments in air is bound by constraints on laser power, divergence, wavelength, pulse duration, and atmospheric parameters. The consequential characteristics of the filaments produced limit some potential applications, particularly those related to a filament’s spatial and temporal extent. Here, we demonstrate, for the first time, the temporal concatenation or stitching of up to 32 filaments, each separated by times typically ${\sim}0.5\,\,{\rm{ns}}$, forming a single stream of coaxial filamenting laser pulses.

Published
2019

46. Nanosecond laser coupling for increased filament ablation

Author

Kerrigan, Haley, Fairchild, Shermineh Rostami, and Richardson, Martin

Abstract

Laser filaments can project intensities sufficient to ablate materials at long ranges, but the clamping of a filament’s intensity to ∼10^14  W/cm^2 limits the effective ablation of targets with which the laser pulses interact. We seek to identify regimes in which auxiliary radiation can be used to augment the ablation created by single filaments. In this work, the combination of an 800 nm, 50 fs beam at single filament intensity and a 1064 nm, 8 ns laser pulse is studied. The ablation of GaAs is quantitatively evaluated for varying interpulse delays. Under optimum conditions, an ∼threefold increase in the ablation is observed. The metrology and surface features of the resultant ablation craters are examined to gain insight on the mechanisms of ablation in the dual-pulse cases.

Published
2019

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