10,263 research outputs found
Matching pursuit-based compressive sensing in a wearable biomedical accelerometer fall diagnosis device
There is a significant high fall risk population, where individuals are susceptible to frequent falls and obtaining significant injury, where quick medical response and fall information are critical to providing efficient aid. This article presents an evaluation of compressive sensing techniques in an accelerometer-based intelligent fall detection system modelled on a wearable Shimmer biomedical embedded computing device with Matlab. The presented fall detection system utilises a database of fall and activities of daily living signals evaluated with discrete wavelet transforms and principal component analysis to obtain binary tree classifiers for fall evaluation. 14 test subjects undertook various fall and activities of daily living experiments with a Shimmer device to generate data for principal component analysis-based fall classifiers and evaluate the proposed fall analysis system. The presented system obtains highly accurate fall detection results, demonstrating significant advantages in comparison with the thresholding method presented. Additionally, the presented approach offers advantageous fall diagnostic information. Furthermore, transmitted data accounts for over 80% battery current usage of the Shimmer device, hence it is critical the acceleration data is reduced to increase transmission efficiency and in-turn improve battery usage performance. Various Matching pursuit-based compressive sensing techniques have been utilised to significantly reduce acceleration information required for transmission.Scopu
Chemoenzymatic Synthesis of Triazololactams Structurally Related to Pancratistatin
Four tricyclic lactams that structurally resemble alkaloids with the pancratistatin skeleton were synthetized from bromobenzene by a chemoenzymatic strategy. The sequence involved enzymatic dihydroxylation, efficient stereodirected oxidation of double bonds, inter- or intramolecular Huisgen cycloaddition, and a solvent-free cyclization. The complex structures were obtained in high chemical and optical purity and may be good candidates for biological testing.Fil: de la Sovera, Victoria. Universidad de la RepĂșblica. Facultad de QuĂmica. Departamento de QuĂmica OrgĂĄnica; UruguayFil: Suescun, Leopoldo. Universidad de la RepĂșblica. Laboratorio de CristalografĂa, Estado SĂłlido y Materiales; UruguayFil: Bellomo Peraza, Ana Ines. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias ; ArgentinaFil: GonzĂĄlez, David. Universidad de la RepĂșblica. Facultad de QuĂmica. Departamento de QuĂmica OrgĂĄnica; Urugua
An optically actuated surface scanning probe
We demonstrate the use of an extended, optically trapped probe that is capable of imaging surface topography with nanometre precision, whilst applying ultra-low, femto-Newton sized forces. This degree of precision and sensitivity is acquired through three distinct strategies. First, the probe itself is shaped in such a way as to soften the trap along the sensing axis and stiffen it in transverse directions. Next, these characteristics are enhanced by selectively position clamping independent motions of the probe. Finally, force clamping is used to refine the surface contact response. Detailed analyses are presented for each of these mechanisms. To test our sensor, we scan it laterally over a calibration sample consisting of a series of graduated steps, and demonstrate a height resolution of ⌠11 nm. Using equipartition theory, we estimate that an average force of only ⌠140 fN is exerted on the sample during the scan, making this technique ideal for the investigation of delicate biological samples
Multi-Professional Perspectives on Adolescent and Young Adult Oncology Across Europe: An e-Delphi Survey
The aims of this article are to describe the ongoing development of adolescent and young adult (AYA) cancer services within the European Union (EU), and to develop consensus on key areas within the field. This survey used an e-Delphi design. An initial survey was distributed via email to professionals working in Europe. A snowball sampling technique was used to promote distribution. Consensus was sought over three rounds from October 2012 to April 2015. Consensus was defined as >80% agreement (âagreeâ or âstrongly agreeâ). Sixty professionals participated in round 1, 106 in round 2, and 61 in round 3. Twenty-six countries were represented across all rounds. Consensus was achieved for: the need for national policy guidance, the importance of patient choice, the validity of the International Charter of Rights for Young People, and some aspects of multi-disciplinary working. There was 75% agreement on a single definition of the patient age range within AYA cancer care. European professionals with expertise in AYA cancer care reached consensus on key elements of care for this group. The optimal AYA age range remained an elusive topic on which to agree. The broad engagement and interest in AYA cancer across the EU through the European Network for Cancer in Children and Adolescents (ENCCA) network was also demonstrated
Data-driven approach to optimum wavelength selection for diffuse optical imaging
The production of accurate and independent images of the changes in concentration of oxyhemoglobin and deoxyhemoglobin by diffuse optical imaging is heavily dependent on which wavelengths of near-infrared light are chosen to interrogate the target tissue. Although wavelengths can be selected by theoretical methods, in practice the accuracy of reconstructed images will be affected by wavelength-specific and system-specific factors such as laser source power and detector sensitivity. We describe the application of a data-driven approach to optimum wavelength selection for the second generation of University College London's multichannel, time-domain optical tomography system (MONSTIR II). By performing a functional activation experiment using 12 different wavelengths between 690 and 870 nm, we were able to identify the combinations of 2, 3, and 4 wavelengths which most accurately reproduced the results obtained using all 12 wavelengths via an imaging approach. Our results show that the set of 2, 3, and 4 wavelengths which produce the most accurate images of functional activation are [770, 810], [770, 790, 850], and [730, 770, 810, 850] respectively, but also that the system is relatively robust to wavelength selection within certain limits. Although these results are specific to MONSTIR II, the approach we developed can be applied to other multispectral near-infrared spectroscopy and optical imaging systems
Qualitative study to understand the barriers to recruiting young people with cancer to BRIGHTLIGHT: a national cohort study in England
Objectives: BRIGHTLIGHT is a national evaluation of cancer services for teenagers and young adults in England. Following challenges with recruitment, our aim was to understand more fully healthcare professionalsâ perspectives of the challenges of recruiting young people to a low-risk observational study, and to provide guidance for future recruitment processes. /
Design: Qualitative. /
Setting: National Health Service (NHS) hospitals in England. /
Methods: Semistructured telephone interviews with a convenience sample of 23 healthcare professionals. Participants included principal investigators/other staff recruiting into the BRIGHTLIGHT study. Data were analysed using framework analysis. /
Results: The emergent themes were linked to levels of research organisational management, described using the levels of social network analysis: micro-level (the individual; in this case the target population to be recruitedâyoung people with cancer); meso-level (the organisation; refers to place of recruitment and people responsible for recruitment); and macro-level (the large-scale or global structure; refers to the wider research function of the NHS and associated policies). Study-related issues occurred across all three levels, which were influenced by the context of the study. At the meso-level, professionalsâ perceptions of young people and communication between professionals generated age/cancer type silos, resulting in recruitment of either children or adults, but not both by the same team, and only in the cancer type the recruiting professional was aligned to. At the macro-level the main barrier was discordant configuration of a research service with a clinical service. /
Conclusions: This study has identified significant barriers to recruitment mainly at the meso-level and macro-level, which are more challenging for research teams to influence. We suggest that interconnected whole-system changes are required to facilitate the success of interventions designed to improve recruitment. Interventions targeted at study design/management and the micro-level only may be less successful. We offer solutions to be considered by those involved at all levels of research for this population
Photodisintegration of three- and four- nucleon systems
Three- and four-nucleon photodisintegration processes are quite efficiently
treated by means of effective two-body integral equations in momentum space. We
recall some aspects of their derivation, present previous and most recent
results obtained within this framework, and discuss general features, trends
and effects observed in these investigations: At low energies final-state
interaction plays an important role. Even more pronounced is the effect of
meson exchange currents. A considerable potential dependence shows up in the
low-energy peak region. The different peak heights are found to be closely
correlated with the corresponding binding energies. Above the peak region only
the difference between potentials with or without p-wave contributions remains
relevant. In the differential cross sections the electric quadrupole
contributions have to be taken into account. The remarkable agreement between
theory and experiment in - radiative capture is achieved only when
incorporating this contribution, together with most of the above-mentioned
effects. In the final part of this report we briefly review also methods
developed, and results achieved in three- and four- nucleon
electrodisintegration. We, in particular, compare them with a recent access to
this problem, based on the construction of nucleon-nucleus potentials via
Marchenko inversion theory.Comment: 20 pages LaTeX and 22 postscript figures included, uses epsfig.sty
and espcrc1.sty. Invited talk at the XVth International Conference on
Few-Body Problems in Physics (22-26 July, 1997, Groningen, The Netherlands).
To be published in the conference proceedings in Nucl. Phys.
A re-appraisal of the reliability of the 20 m multi-stage shuttle run test
This is the author's PDF version of an article published in European journal of applied physiology in 2007. The original publication is available at www.springerlink.co
Comparing Diet and Exercise Monitoring Using Smartphone App and Paper Diary: A Two-Phase Intervention Study
Background: There is increasing recognition that personalized approaches may be more effective in helping people establish healthier eating patterns and exercise more, and that this approach may be particularly effective in adolescents. Objective: The objective of this study was to investigate the use of a smartphone app (FoodWiz2) in supporting healthy lifestyle choices in adolescence. Methods: Participants (N=34: 11 male, 23 female) aged 16-19 years in full- or part-time education were recruited from sixth form colleges, schools, and other further education establishments in Norfolk and Suffolk, United Kingdom, between February and May 2015. Participants recorded food intake and exercise using a paper diary for 4-5 weeks and then used the app for the same duration. Initial nutrition education and general support were provided during the paper diary use, but the app included personalized messages sent in response to app activity. At the end of each study phase, participants completed an online questionnaire to describe their experience of using the paper diary and app. Results: Record completion declined throughout the study, possibly affected by examination pressure. Food intake data showed increased fruit consumption and significantly reduced consumption of chocolate snacks (P=.01) and fizzy drinks (P=.002) among participants using the app. Questionnaire responses indicated that the app was generally preferred to the paper diary, in particular, the app was seen as less boring to use (P=.03) and more acceptable in social settings (P<.001). Conclusions: This app-based approach has shown the potential for a more effective approach to improving adolescent diet and exercise levels
Involving young people in BRIGHTLIGHT from study inception to secondary data analysis: Insights from 10 years of user involvement
© The Author(s). Background Young people with cancer, broadly those aged 13â24 years at diagnosis, warrant special attention; physiological and psychological growth creates complex psychosocial needs which neither adult nor child systems are suitably designed to deal with. Resulting from these needs, they are often described as âvulnerableâ, âhard to reachâ and âdifficult to engageâ, and consequently are often over looked for patient and public involvement/ engagement (PPIE) roles. In our study âBRIGHTLIGHTâ, we set out to evaluate whether specialist care for young people adds value, ensuring young people were central to our PPIE activities. We believe that BRIGHTLIGHT is unique as a very large study of young people with cancer which has successfully overcome the challenges of including young people in the research process so we are confident that they have influenced every aspect of study design, conduct and dissemination. Methods We chronicle a period of 10 years, over which we describe our approach and our methods to involving young people in PPIE activities in BRIGHTLIGHT. We describe the feasibility work, study set up, conduct and dissemination of our findings, and weave through our story of PPIE to illustrate its benefits. Through the narration of our experience we highlight significant points that both influenced and changed our direction of travel. We reflect on our experiences and offer some practical advice for those looking to do the same. Results In the 10 years since the BRIGHTLIGHT feasibility work began we have involved more than 1200 young people. Their contributions have been isolated and mapped over a 10-year period. We begin at an early step of identifying what research questions to prioritize, we then plot PPIE activities for one of these research priorities, place of care, which evolved into BRIGHTLIGHT. We document steps along the way to evidence the impact of this involvement. Conclusions Young people can make a valuable contribution to healthcare research given adequate support from the research team. Although some challenges exist, we propose that the benefits to young people, researchers and the study considerably outweigh these challenges and PPIE with young people should be integrated in all similar research studies
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