16 results on '"Jim Parr"'
Search Results
2. Machine learning for detection of stenoses and aneurysms: application in a physiologically realistic virtual patient database.
- Author
-
Gareth Jones, Jim Parr, Perumal Nithiarasu, and Sanjay Pant
- Published
- 2021
3. Machine learning for detection of stenoses and aneurysms: application in a physiologically realistic virtual patient database
- Author
-
Perumal Nithiarasu, Gareth Jones, Sanjay Pant, and Jim Parr
- Subjects
FOS: Computer and information sciences ,Computer Science - Machine Learning ,Databases, Factual ,Arterial disease ,Subclavian Artery ,02 engineering and technology ,computer.software_genre ,Severity of Illness Index ,Machine Learning (cs.LG) ,030218 nuclear medicine & medical imaging ,Machine Learning ,User-Computer Interface ,0302 clinical medicine ,Virtual patient ,Subclavian artery stenosis ,Carotid Stenosis ,Stenosis ,Database ,Healthy subjects ,3. Good health ,Peripheral ,medicine.anatomical_structure ,Modeling and Simulation ,Screening ,Algorithms ,Biotechnology ,Artery ,0206 medical engineering ,Pulse wave haemodynamics ,FOS: Physical sciences ,Machine learning ,Models, Biological ,Sensitivity and Specificity ,Peripheral Arterial Disease ,03 medical and health sciences ,Aneurysm ,medicine ,Humans ,Original Paper ,business.industry ,Mechanical Engineering ,medicine.disease ,020601 biomedical engineering ,Physics - Medical Physics ,Virtual patients ,Regional Blood Flow ,Neural Networks, Computer ,Medical Physics (physics.med-ph) ,Artificial intelligence ,business ,computer ,Aortic Aneurysm, Abdominal - Abstract
This study presents an application of machine learning (ML) methods for detecting the presence of stenoses and aneurysms in the human arterial system. Four major forms of arterial disease -- carotid artery stenosis (CAS), subclavian artery stenosis (SAC), peripheral arterial disease (PAD), and abdominal aortic aneurysms (AAA) -- are considered. The ML methods are trained and tested on a physiologically realistic virtual patient database (VPD) containing 28,868 healthy subjects, which is adapted from the authors previous work and augmented to include the four disease forms. Six ML methods -- Naive Bayes, Logistic Regression, Support Vector Machine, Multi-layer Perceptron, Random Forests, and Gradient Boosting -- are compared with respect to classification accuracies and it is found that the tree-based methods of Random Forest and Gradient Boosting outperform other approaches. The performance of ML methods is quantified through the F1 score and computation of sensitivities and specificities. When using all the six measurements, it is found that maximum F1 scores larger than 0.9 are achieved for CAS and PAD, larger than 0.85 for SAS, and larger than 0.98 for both low- and high-severity AAAs. Corresponding sensitivities and specificities are larger than 90% for CAS and PAD, larger than 85% for SAS, and larger than 98% for both low- and high-severity AAAs. When reducing the number of measurements, it is found that the performance is degraded by less than 5% when three measurements are used, and less than 10% when only two measurements are used for classification. For AAA, it is shown that F1 scores larger than 0.85 and corresponding sensitivities and specificities larger than 85% are achievable when using only a single measurement. The results are encouraging to pursue AAA monitoring and screening through wearable devices which can reliably measure pressure or flow-rates, Changelog: Added a bullet point in the discussion (end of section 3.3)
- Published
- 2021
4. A proof of concept study for machine learning application to stenosis detection
- Author
-
Perumal Nithiarasu, Jim Parr, Sanjay Pant, and Gareth Jones
- Subjects
Diagnostic Imaging ,FOS: Computer and information sciences ,Computer Science - Machine Learning ,Virtual patient database ,Computer science ,0206 medical engineering ,Biomedical Engineering ,Binary number ,Pulse wave haemodynamics ,02 engineering and technology ,Constriction, Pathologic ,Machine learning ,computer.software_genre ,Proof of Concept Study ,Machine Learning (cs.LG) ,Machine Learning ,03 medical and health sciences ,0302 clinical medicine ,Virtual patient ,Pulse wave propagation ,Classifier (linguistics) ,medicine ,Humans ,business.industry ,Ranging ,Standard methods ,medicine.disease ,020601 biomedical engineering ,Computer Science Applications ,Stenosis ,Proof of concept ,Original Article ,Artificial intelligence ,business ,computer ,Arterial disease diagnosis ,030217 neurology & neurosurgery - Abstract
This proof of concept (PoC) assesses the ability of machine learning (ML) classifiers to predict the presence of a stenosis in a three vessel arterial system consisting of the abdominal aorta bifurcating into the two common iliacs. A virtual patient database (VPD) is created using one-dimensional pulse wave propagation model of haemodynamics. Four different machine learning (ML) methods are used to train and test a series of classifiers-both binary and multiclass-to distinguish between healthy and unhealthy virtual patients (VPs) using different combinations of pressure and flow-rate measurements. It is found that the ML classifiers achieve specificities larger than 80% and sensitivities ranging from 50 to 75%. The most balanced classifier also achieves an area under the receiver operative characteristic curve of 0.75, outperforming approximately 20 methods used in clinical practice, and thus placing the method as moderately accurate. Other important observations from this study are that (i) few measurements can provide similar classification accuracies compared to the case when more/all the measurements are used; (ii) some measurements are more informative than others for classification; and (iii) a modification of standard methods can result in detection of not only the presence of stenosis, but also the stenosed vessel. Graphical Abstract An overview of methodology fo the creation of virtual patients and their classification.
- Published
- 2021
5. Objectively Monitoring Amyotrophic Lateral Sclerosis Patient Symptoms During Clinical Trials With Sensors: Observational Study (Preprint)
- Author
-
Luis Garcia-Gancedo, Madeline L Kelly, Arseniy Lavrov, Jim Parr, Rob Hart, Rachael Marsden, Martin R Turner, Kevin Talbot, Theresa Chiwera, Christopher E Shaw, and Ammar Al-Chalabi
- Abstract
BACKGROUND Objective symptom monitoring of patients with Amyotrophic Lateral Sclerosis (ALS) has the potential to provide an important source of information to evaluate the impact of the disease on aspects of real-world functional capacity and activities of daily living in the home setting, providing useful objective outcome measures for clinical trials. OBJECTIVE This study aimed to investigate the feasibility of a novel digital platform for remote data collection of multiple symptoms—physical activity, heart rate variability (HRV), and digital speech characteristics—in 25 patients with ALS in an observational clinical trial setting to explore the impact of the devices on patients’ everyday life and to record tolerability related to the devices and study procedures over 48 weeks. METHODS In this exploratory, noncontrolled, nondrug study, patients attended a clinical site visit every 3 months to perform activity reference tasks while wearing a sensor, to conduct digital speech tests and for conventional ALS monitoring. In addition, patients wore the sensor in their daily life for approximately 3 days every month for the duration of the study. RESULTS The amount and quality of digital speech data captured at the clinical sites were as intended, and there were no significant issues. All the home monitoring sensor data available were propagated through the system and were received as expected. However, the amount and quality of physical activity home monitoring data were lower than anticipated. A total of 3 or more days (or partial days) of data were recorded for 65% of protocol time points, with no data collected for 24% of time points. At baseline, 24 of 25 patients provided data, reduced to 13 of 18 patients at Week 48. Lower-than-expected quality HRV data were obtained, likely because of poor contact between the sensor and the skin. In total, 6 of 25 patients had mild or moderate adverse events (AEs) in the skin and subcutaneous tissue disorders category because of skin irritation caused by the electrode patch. There were no reports of serious AEs or deaths. Most patients found the sensor comfortable, with no or minimal impact on daily activities. CONCLUSIONS The platform can measure physical activity in patients with ALS in their home environment; patients used the equipment successfully, and it was generally well tolerated. The quantity of home monitoring physical activity data was lower than expected, although it was sufficient to allow investigation of novel physical activity end points. Good-quality in-clinic speech data were successfully captured for analysis. Future studies using objective patient monitoring approaches, combined with the most current technological advances, may be useful to elucidate novel digital biomarkers of disease progression.
- Published
- 2019
6. Dans les musées des sciences: des faits ou des idées?
- Author
-
Jim Parr
- Abstract
Les musees consacres aux sciences et aux techniques sont aujourd'hui tres apprecies du public et surtout, semble-t-il, des jeunes. Dans cet article, le Directeur general du Centre des sciences de l'Ontario (Canada) se livre a une analyse sans fard de quelques-uns des principaux problemes que rencontre ce type de musees.
- Published
- 2009
7. Potential for dietary phytase to improve the nutritive value of canola protein concentrate and decrease phosphorus output in rainbow trout (Oncorhynchus mykiss) held in 11°C fresh water
- Author
-
Ian Forster, Dave A. Higgs, Jim Parr, Mahmoud Rowshandeli, and B.S. Dosanjh
- Subjects
Phytic acid ,Meal ,food.ingredient ,biology ,Phosphorus ,chemistry.chemical_element ,Aquatic Science ,biology.organism_classification ,chemistry.chemical_compound ,Trout ,food ,Animal science ,chemistry ,Botany ,Phytase ,Rainbow trout ,Canola ,Salmonidae - Abstract
This study assessed the potential for using dietary phytase to improve the nutritive value of canola protein concentrate (CPC) for rainbow trout, and to concomitantly minimize phosphorus discharge into the environment. Eight diets were prepared. LT-anchovy meal (AM) provided 89% of the protein in the basal diet, whereas in the remaining diets, 59% of the protein originated from CPC by replacement of AM protein. Four CPC diets were supplemented with phytase (Natuphos®) at levels of either 0, 500, 1500 or 4500 phytase units (FTU)/kg diet together with 4505 mg/kg phosphorus. Two CPC diets contained 1500 FTU/kg and either 0 or 2253 mg/kg of supplemental phosphorus. The seventh CPC diet contained no phytase or supplemental phosphorus. A commercial trout feed served as an industry control. All diets were fed to triplicate groups of rainbow trout (initial weight, 17.9 g) to satiation daily for 84 days. Mean water temperature was 11.0°C. The level of phytic acid degradation and the apparent availability of dietary phosphorus were ascertained for all groups. Fish fed the CPC diets, regardless of their phytase and phosphorus levels, exhibited growth rates, feed efficiencies and protein utilization comparable to those of control fish. There was, however, a clear positive dose-response of phytase on dietary phytate digestibility and phosphorus availability was improved significantly by the highest level of phytase. We conclude that dietary phytase has potential to improve the nutritive quality of CPC for rainbow trout and the availability of phytate phosphorus.
- Published
- 1999
8. 'The Culture of Contentment,' by John Kenneth Galbraith; with allusions to 'The Party System,' by Hilaire Belloc and Cecil Chesterton
- Author
-
Jim Parr
- Subjects
media_common.quotation_subject ,Philosophy ,Political economy ,Contentment ,Religious studies ,media_common - Published
- 1993
9. Science museums: facts or ideas?
- Author
-
Jim Parr
- Subjects
Museology ,Conservation - Published
- 1992
10. The Chesterton Tradition in Modern Journalism
- Author
-
Philip Marchand, Brad Miner, Robert Fulford, Michael Dirda, Jim Parr, and Gerald Owen
- Subjects
Media studies ,Journalism ,Sociology ,Social science ,Panel discussion - Published
- 1992
11. The Kladruby Games, the Paralympics, and the pre-history of disability sport
- Author
-
Roman Reismüller and Jim Parry
- Subjects
Kladruby Games ,Paralympics ,disability sport ,Vojmír Srdečný ,Sports ,GV557-1198.995 ,Sports medicine ,RC1200-1245 - Abstract
The place of Dr Ludwig Guttmann in the founding history of the Paralympic Games is universally acknowledged. Briefly stated, Guttmann is credited with the aspiration to improve the dismal prospects of postwar spinal injury patients, and the inspiration of using sports as rehabilitative practices. Given his initiation of the Stoke Mandeville Games in 1948 with a small-scale archery contest between two local teams, he was able to draw a ready parallel between his beginnings and the model of the London Olympic Games, and in a few short years the multi-disability Paralympic Games had been established. However, there was both an historical context and a co-history to these brief details – there are lessons from both time and place. We must not forget (or fail to acknowledge) some of the pre-history and parallel histories, which we should attempt to recover. This article presents an account of the development of the Kladruby Games in Czechoslovakia from 1948, which in 2017 celebrate their 100th edition, in order to bring to light some of the hidden history of disability sport. We might be led to speculate on how the Kladruby Games might have developed from these very promising beginnings, had Srdečný received earlier support from the authorities, and the impetus to consider Olympic connections. Such speculations we consider to be fruitless, given the very different conceptions of disability sport at work here. Srdečný’s continuing commitment was to seeing the Kladruby Games as an impetus to the rehabilitative and recreational benefits of sport, rather than the contradictions experienced by the Paralympics in balancing elite performance values with its other aims.
- Published
- 2017
- Full Text
- View/download PDF
12. The Chesterton Paradox Factory
- Author
-
Jim Parr
- Subjects
Engineering ,business.industry ,Factory (object-oriented programming) ,business ,Management - Published
- 1977
13. 'The Second Industrial Divide,' by Michael J. Piore and Charles F. Sabel; and 'The Turning Point,' by Fritjof Capra
- Author
-
Jim Parr
- Subjects
biology ,Philosophy ,Turning point ,Capra ,biology.organism_classification ,Humanities - Published
- 1985
14. The Schumacher Lectures, Volumes 1 and 2
- Author
-
Jim Parr
- Published
- 1987
15. Výzvy pro letní i zimní Olympijské hry mládeže
- Author
-
Jim Parry and Steffie Lucidarme
- Subjects
Science ,Social Sciences - Abstract
Tento článek se věnuje Olympijským hrám mládeže, které se poprvé konaly v Singapuru v srpnu 2010 a které se vyvinuly z Evropského olympijského festivalu mládeže (EYOF), jenž se poprvé konal v Bruselu v roce 1991. Vzhledem k účasti 3500 sportovců ve věku 14 až 18 let z 205 Národních olympijských výborů a programem zahrnujícím kompletní Olympijský program a kulturní a výchovný program (CEP) jsou Olympijské hry mládeže významnou událostí vyžadující zamyšlení. V textu se podíváme na sportovní program, některé nové sportovní formy, disciplíny a soutěže (např. FIBA33, skoky do vody za měsíčního svitu), mixové soutěže pro hochy a dívky a mixové soutěže pro zástupce různých NOV, technické inovace (např. laserové pistole), problémy s účastí vzhledem k věku a rovné příležitosti, nezralost a poškozování, identifikaci talentů a možné zneužívání. Budeme se také stručně zabývat novým kulturním a výchovným programem, zdůrazníme důležitost jeho existence a zmíníme jeho problémy. Nakonec stručně představíme nadcházející Zimní olympijské hry mládeže v Innsbrucku, dále pak naděje a aspirace pro budoucí Olympijské hry mládeže.
- Published
- 2011
16. Two ways of conceiving time in sports [Dva způsoby pojímání času ve sportu]
- Author
-
Jim Parry and Irena Martínková
- Subjects
Time ,sport ,regulation ,experiencing ,Heidegger ,original temporality ,Sports medicine ,RC1200-1245 - Abstract
BACKGROUND: This paper explores a foundational concept for our understanding of sport - the concept of time. OBJECTIVE: The objective of this paper is to explain two different concepts of time in sport. METHODS: Our methodology is philosophical, involving both conceptual and phenomenological analysis and the application of the outcomes to sports practice. RESULTS: First, two concepts of time and their role in sport are discussed - time as linear, measurable, homogeneous and objective; and time as discussed in the philosophy of existence, namely in the work of Martin Heidegger, in which he introduces the concept of "original temporality". Second, sports are classified into four different groups depending on the role of time in them, and basic characterisations of each are worked out. While within the first three groups the concept of objective time is salient, a suggestion is made regarding the potential of the fourth group, which includes high risk sports, for the realisation of original temporality. CONCLUSIONS: The two concepts of time presented in this paper explain the basis of sport and show its relationship to the human experiencing of sport activities. The text shows that the concept of objective time is necessary for the practice of some sports, whilst other sports use it rather in a secondary way, e. g. for the comparison of winners. Original temporality as a basis of human experiencing is present in all sports. While in most of them it is limited by objective time, in some sports (especially in high risk sports) the possibility of the realization of original temporality is opened.[VÝCHODISKA: Text se zabývá jedním ze základních pojmů ve sportu - pojmem času. CÍLE: Cílem textu je vysvětlit dvě různá pojetí času ve sportu. METODIKA: Naše metoda je filosofická a zahrnuje pojmovou a fenomenologickou analýzu a aplikaci výsledků do sportovní praxe. VÝSLEDKY: Nejprve jsou diskutovány dva pojmy času a jejich role ve sportu - pojetí času jakožto lineárního, měřitelného, homogenního a objektivního a čas v podání filosofie existence, zvláště v pojetí Martina Heideggera, který představuje pojem "původní časovost". Poté jsou sporty rozděleny do čtyř různých skupin v závislosti na roli, kterou v nich hraje čas, a jsou rozpracovány jejich základní charakteristiky. Zatímco v rámci prvních tří skupin se ukazuje důležitost objektivního času, čtvrtá skupina sportů, která zahrnuje vysoce rizikové sporty, poukazuje k možnosti realizace původní časovosti. ZÁVĚRY: V textu jsou představena dvě pojetí času, která vysvětlují základ sportu a která jsou vztažena k lidskému prožívání v rámci sportovních aktivit. V textu je ukázáno, že pojem objektivního času je nutný pro praktikování některých sportů, jiné sporty jej využívají spíše sekundárně, např. pro možnost porovnávání vítězů. Původní časovost se jakožto základ lidského prožívání ukazuje ve všech sportech. Zatímco v některých sportech je původní časovost omezována objektivním časem, v jiných (zvláště ve vysoce rizikových sportech) se naopak ukazuje možnost realizace původní časovosti.]
- Published
- 2011
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.