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Wilson R, King M, Butler NMH, Carroll DC, Frazer TP, Duff MJ, Higginson A, Dance RJ, Jarrett J, Davidson ZE, Armstrong CD, Liu H, Hawkes SJ, Clarke RJ, Neely D, Gray RJ, McKenna P. Influence of spatial-intensity contrast in ultraintense laser-plasma interactions. Sci Rep 2022; 12:1910. [PMID: 35115579 PMCID: PMC8814164 DOI: 10.1038/s41598-022-05655-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 01/05/2022] [Indexed: 11/09/2022] Open
Abstract
Increasing the intensity to which high power laser pulses are focused has opened up new research possibilities, including promising new approaches to particle acceleration and phenomena such as high field quantum electrodynamics. Whilst the intensity achievable with a laser pulse of a given power can be increased via tighter focusing, the focal spot profile also plays an important role in the interaction physics. Here we show that the spatial-intensity distribution, and specifically the ratio of the intensity in the peak of the laser focal spot to the halo surrounding it, is important in the interaction of ultraintense laser pulses with solid targets. By comparing proton acceleration measurements from foil targets irradiated with by a near-diffraction-limited wavelength scale focal spot and larger F-number focusing, we find that this spatial-intensity contrast parameter strongly influences laser energy coupling to fast electrons. We find that for multi-petawatt pulses, spatial-intensity contrast is potentially as important as temporal-intensity contrast.
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Affiliation(s)
- R Wilson
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - M King
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK.,The Cockcroft Institute, Sci-Tech Daresbury, Warrington, WA4 4AD, UK
| | - N M H Butler
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - D C Carroll
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - T P Frazer
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - M J Duff
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - A Higginson
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - R J Dance
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - J Jarrett
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - Z E Davidson
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - C D Armstrong
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK.,Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - H Liu
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK.,Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - S J Hawkes
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - R J Clarke
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - D Neely
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK.,Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - R J Gray
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - P McKenna
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK. .,The Cockcroft Institute, Sci-Tech Daresbury, Warrington, WA4 4AD, UK.
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Davidson ZE, Bray P, Rose K, Rodrigues MJ, Corben L, North KN, Ryan MM, Burns J. Development of clinical practice guidelines for allied health and nursing assessment and management of Duchenne muscular dystrophy. Disabil Rehabil 2021; 44:5450-5467. [PMID: 34165385 DOI: 10.1080/09638288.2021.1936221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE To provide evidence-based guidance specific to allied health and nursing practice for the assessment and management of individuals with Duchenne muscular dystrophy (DMD). MATERIALS AND METHODS Thirteen key focus areas were identified in consultation with health professionals and consumer advocacy groups. A series of systematic literature reviews were conducted to identify assessment and management strategies for each key focus area. A consensus process using modified Delphi methodology, including an Australia-New Zealand expert consensus meeting, was conducted. Recommendations underwent consultative review with key groups before being finalised and prepared for dissemination. RESULTS This clinical practice guideline (CPG) generated 19 evidence-based recommendations, 117 consensus-based recommendations and five research recommendations across the 13 focus areas to inform allied health assessment and management of individuals with DMD. CONCLUSIONS The resulting recommendations can be used in conjunction with existing medical CPGs to improve, standardise and advocate for allied health and rehabilitation care in DMD. The process used here may be useful for the development of CPGs in other rare diseases.Implications for rehabilitationImplementation-ready evidence-based statements to guide clinical care of individuals with DMD are provided with the potential to improve participation, function in the community and quality of life.A model for developing best practice statements for other rare neurological diseases is described.Allied health and nursing health professionals should focus research efforts to generate quality evidence to support rehabilitation practice.
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Affiliation(s)
- Z E Davidson
- Murdoch Children's Research Institute, Parkville, Australia.,Neurology Department, Royal Children's Hospital, Parkville, Australia.,Department of Nutrition, Dietetics and Food, School of Clinical Sciences, Monash University, Clayton, Australia
| | - P Bray
- The Children's Hospital at Westmead, Westmead, Australia.,School of Health Sciences, University of Sydney, Sydney, Australia
| | - K Rose
- School of Health Sciences, University of Sydney, Sydney, Australia.,Department of Physiotherapy, Sydney Children's Hospital, Randwick, Australia.,ATOM International Pty Ltd, Newcastle upon Tyne, UK
| | - M J Rodrigues
- Muscular Dystrophy Association of New Zealand, Auckland, New Zealand.,Department of Neurology, Auckland City Hospital, Auckland, New Zealand
| | - L Corben
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Children's Research Institute, Parkville, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, Australia.,School of Psychological Sciences, Monash University, Clayton, Australia
| | - K N North
- Murdoch Children's Research Institute, Parkville, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, Australia
| | - M M Ryan
- Murdoch Children's Research Institute, Parkville, Australia.,Neurology Department, Royal Children's Hospital, Parkville, Australia.,Department of Nutrition, Dietetics and Food, School of Clinical Sciences, Monash University, Clayton, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, Australia
| | - J Burns
- The Children's Hospital at Westmead, Westmead, Australia.,School of Health Sciences, University of Sydney, Sydney, Australia
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Duff MJ, Wilson R, King M, Gonzalez-Izquierdo B, Higginson A, Williamson SDR, Davidson ZE, Capdessus R, Booth N, Hawkes S, Neely D, Gray RJ, McKenna P. High order mode structure of intense light fields generated via a laser-driven relativistic plasma aperture. Sci Rep 2020; 10:105. [PMID: 31919383 PMCID: PMC6952361 DOI: 10.1038/s41598-019-57119-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/03/2019] [Indexed: 11/10/2022] Open
Abstract
The spatio-temporal and polarisation properties of intense light is important in wide-ranging topics at the forefront of extreme light-matter interactions, including ultrafast laser-driven particle acceleration, attosecond pulse generation, plasma photonics, high-field physics and laboratory astrophysics. Here, we experimentally demonstrate modifications to the polarisation and temporal properties of intense light measured at the rear of an ultrathin target foil irradiated by a relativistically intense laser pulse. The changes are shown to result from a superposition of coherent radiation, generated by a directly accelerated bipolar electron distribution, and the light transmitted due to the onset of relativistic self-induced transparency. Simulations show that the generated light has a high-order transverse electromagnetic mode structure in both the first and second laser harmonics that can evolve on intra-pulse time-scales. The mode structure and polarisation state vary with the interaction parameters, opening up the possibility of developing this approach to achieve dynamic control of structured light fields at ultrahigh intensities.
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Affiliation(s)
- M J Duff
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - R Wilson
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - M King
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | | | - A Higginson
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - S D R Williamson
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - Z E Davidson
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - R Capdessus
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - N Booth
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - S Hawkes
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - D Neely
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK.,Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | - R J Gray
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK
| | - P McKenna
- SUPA Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK.
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Davidson ZE, Gonzalez-Izquierdo B, Higginson A, Lancaster KL, Williamson SDR, King M, Farley D, Neely D, McKenna P, Gray RJ. An optically multiplexed single-shot time-resolved probe of laser-plasma dynamics. Opt Express 2019; 27:4416-4423. [PMID: 30876060 DOI: 10.1364/oe.27.004416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/01/2019] [Indexed: 06/09/2023]
Abstract
We introduce a new approach to temporally resolve ultrafast micron-scale processes via the use of a multi-channel optical probe. We demonstrate that this technique enables highly precise time-resolved, two-dimensional spatial imaging of intense laser pulse propagation dynamics, plasma formation and laser beam filamentation within a single pulse over four distinct time frames. The design, development and optimization of the optical probe system is presented, as are representative experimental results from the first implementation of the multi-channel probe with a high-power laser pulse interaction with a helium gas jet target.
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Barbour LR, Ho MYL, Davidson ZE, Palermo CE. Challenges and opportunities for measuring the impact of a nutrition programme amongst young people at risk of food insecurity: A pilot study. NUTR BULL 2016. [DOI: 10.1111/nbu.12200] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- L. R. Barbour
- Department of Nutrition and Dietetics; Monash University; Clayton Vic. Australia
| | | | - Z. E. Davidson
- Department of Nutrition and Dietetics; Monash University; Clayton Vic. Australia
| | - C. E. Palermo
- Department of Nutrition and Dietetics; Monash University; Clayton Vic. Australia
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Porter J, Adderley M, Bonham M, Costa RJS, Dart J, McCaffrey T, Ryan L, Davidson ZE. The effect of dietary interventions and nutritional supplementation on bone mineral density in otherwise healthy adults with osteopenia: A systematic review. NUTR BULL 2016. [DOI: 10.1111/nbu.12199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- J. Porter
- Department of Food, Nutrition and Dietetics; Monash University; Notting Hill Australia
- Dietetics Department; Eastern Health; Box Hill Australia
| | - M. Adderley
- Department of Food, Nutrition and Dietetics; Monash University; Notting Hill Australia
| | - M. Bonham
- Department of Food, Nutrition and Dietetics; Monash University; Notting Hill Australia
| | - R. J. S. Costa
- Department of Food, Nutrition and Dietetics; Monash University; Notting Hill Australia
| | - J. Dart
- Department of Food, Nutrition and Dietetics; Monash University; Notting Hill Australia
| | - T. McCaffrey
- Department of Food, Nutrition and Dietetics; Monash University; Notting Hill Australia
| | - L. Ryan
- Department of Food, Nutrition and Dietetics; Monash University; Notting Hill Australia
- Head of Department Natural Sciences; Galway-Mayo Institute of Technology; Galway Ireland
| | - Z. E. Davidson
- Department of Food, Nutrition and Dietetics; Monash University; Notting Hill Australia
- Clinical Sciences Theme; Murdoch Children's Research Institute; Melbourne Australia
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Palermo C, Davidson ZE, Hay M. A cross-sectional study exploring the different roles of individual and group assessment methods in assessing public health nutrition competence. J Hum Nutr Diet 2016; 29:523-8. [PMID: 26781685 DOI: 10.1111/jhn.12351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Competency in the practice of public health is essential for dietitians, yet little is known about credible and dependable assessment in this field. The present study aimed to investigate the role of individual and group assessment tasks as elements of a public health nutrition competency-based assessment system. METHODS Assessment performance data from 158 dietetics students (three group tasks and one individual task) who had completed a practical placement learning experience in a public health nutrition setting were examined using nonparametric techniques. All 158 students were deemed individually 'competent' on completion of the placement. RESULTS The median mark was significantly lower for the individual compared to the group task, with a greater range of marks achieved in the individual assessment. There was a weak relationship between individual and group marks for the whole cohort (n = 158) (Spearman's rho correlation coefficient = 0.193, P = 0.015). Bland-Altman analysis showed that the mean (SD) agreement between the two assessment tasks was -5.9 (17.7) marks. Systematic bias between the two tasks was also demonstrated, indicating that students with the lowest average mark of the two assessments scored lower on the individual assessment task compared to their group task and those who had a higher average mark scored higher on the individual group assessment compared to their group task. CONCLUSIONS Student performance in public health differs between individual and group assessment. Individual assessment appears to differentiate between students, yet group work is essential for the development of teamwork skills. Both should be considered in the judgement of public health nutrition competency.
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Affiliation(s)
- C Palermo
- Department of Nutrition and Dietetics, Faculty of Medicine, Nursing and Health Sciences, Monash University, Notting Hill, VIC, Australia
| | - Z E Davidson
- Department of Nutrition and Dietetics, Faculty of Medicine, Nursing and Health Sciences, Monash University, Notting Hill, VIC, Australia
| | - M Hay
- Office of the Deputy Dean (Education), Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
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Gibson SJ, Davidson ZE. An observational study investigating the impact of simulated patients in teaching communication skills in preclinical dietetic students. J Hum Nutr Diet 2015; 29:529-36. [DOI: 10.1111/jhn.12352] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- S. J. Gibson
- Department Nutrition and Dietetics; Monash University; Notting Hill VIC Australia
| | - Z. E. Davidson
- Department Nutrition and Dietetics; Monash University; Notting Hill VIC Australia
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Davidson ZE, Ryan MM, Kornberg AJ, Sinclair K, Cairns A, Walker KZ, Truby H. Observations of body mass index in Duchenne muscular dystrophy: a longitudinal study. Eur J Clin Nutr 2014; 68:892-7. [PMID: 24824013 DOI: 10.1038/ejcn.2014.93] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 03/06/2014] [Accepted: 04/06/2014] [Indexed: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES Nutritional issues that are associated with Duchenne muscular dystrophy (DMD) remain poorly understood. The aim of this analysis was to describe and explore longitudinal observations of body mass index (BMI) in a cohort of children with DMD. SUBJECTS/METHODS Anthropometric and clinical characteristics were collected retrospectively and longitudinally for boys with DMD seen in two large neuromuscular clinics. BMI Z-scores were determined using the Centers for Disease Control and Prevention reference values for children (2000). RESULTS Medical records (n=193) were examined from which 75% were included for analysis. The mean age of the cohort at the time of data collection was 11.9 years, with 72% of patients currently or previously using steroids. The highest prevalence of obesity based on the BMI Z-score was 50% at the age of 10 years. Longitudinally, BMI Z-scores from the age of 2 to 12 years plot approximately one s.d. above the mean, after which there is a marked and progressive decline. BMI gainers were identified for whom BMI Z-score increased by 1.65 units compared with the 0.09 units in non-gainers. BMI gainers were younger when they had their first BMI measurement (5.9 vs 7.2 years), and this measure was significantly lower compared with the non-gainers (BMI Z-score: 0.04 vs 1.17). In this cohort, BMI was associated with age, ambulatory status and lung function. CONCLUSIONS This study demonstrates that boys with DMD using steroid therapy experience shifts in BMI. A declining BMI appears to be associated with increasing age. Interpretation of growth patterns is limited here by a lack of normative growth references in DMD.
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Affiliation(s)
- Z E Davidson
- 1] Department Nutrition and Dietetics, Monash University, Melbourne, Victoria, Australia [2] Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - M M Ryan
- 1] Murdoch Childrens Research Institute, Melbourne, Victoria, Australia [2] Department of Neurology, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - A J Kornberg
- 1] Murdoch Childrens Research Institute, Melbourne, Victoria, Australia [2] Department of Neurology, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - K Sinclair
- Neurosciences Department, Royal Children's Hospital, Brisbane, Queensland, Australia
| | - A Cairns
- Neurosciences Department, Royal Children's Hospital, Brisbane, Queensland, Australia
| | - K Z Walker
- Department Nutrition and Dietetics, Monash University, Melbourne, Victoria, Australia
| | - H Truby
- Department Nutrition and Dietetics, Monash University, Melbourne, Victoria, Australia
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