Computational Modeling of Geometry Dependent Phonon Transport in Silicon Nanostructures

Recent experiments have demonstrated that thermal properties of semiconductor nanostructures depend on nanostructure boundary geometry. Phonons are quantized mechanical vibrations that are the dominant carrier of heat in semiconductor materials and their aggregate behavior determine a nanostructure\u27s thermal performance. Phonon-geometry scattering processes as well as waveguiding effects which result from coherent phonon interference are responsible for the shape dependence of thermal transport in these systems. Nanoscale phonon-geometry interactions provide a mechanism by which nanostructure geometry may be used to create materials with targeted thermal properties. However, the ability to manipulate material thermal properties via controlling nanostructure geometry is contingent upon first obtaining increased theoretical understanding of fundamental geometry induced phonon scattering processes and having robust analytical and computational models capable of exploring the nanostructure design space, simulating the phonon scattering events, and linking the behavior of individual phonon modes to overall thermal behavior. The overall goal of this research is to predict and analyze the effect of nanostructure geometry on thermal transport. To this end, a harmonic lattice-dynamics based atomistic computational modeling tool was created to calculate phonon spectra and modal phonon transmission coefficients in geometrically irregular nanostructures. The computational tool is used to evaluate the accuracy and regimes of applicability of alternative computational techniques based upon continuum elastic wave theory. The model is also used to investigate phonon transmission and thermal conductance in diameter modulated silicon nanowires. Motivated by the complexity of the transmission results, a simplified model based upon long wavelength beam theory was derived and helps explain geometry induced phonon scattering of low frequency nanowire phonon modes

Pregnancy and weight monitoring : a feasibility study of weightcharts and midwife support

Funding Information The Burdett Trust for Nursing.Peer reviewedPublisher PD

J16 Exploring the acceptability and key components for success of a 12 month physical activity intervention in early to mid-stage Huntington's disease

Background The PACE-HD trial investigated the feasibility of conducting a randomised controlled trial of a 12-month physical activity intervention delivered by physiotherapists. Aim To conduct a process evaluation of the PACE-HD intervention to specifically assess intervention components affecting acceptability and fidelity of intervention delivery. Method Intervention delivery and acceptability was assessed via an end of study questionnaire completed by participants randomised to receive the intervention as part of an evaluation framework. Questionnaires required respondents to rate items relating to various intervention components on a scale from 1 [strongly disagree] to 5 [strongly agree] and additional open text questions. Scores of 4 and above were rated as positive. Results Twenty participants completed the questionnaire. Responses regarding the support of therapists were largely positive (99%) with full enjoyment of and satisfaction with coach-led sessions (100%), plus high enjoyment of self-supported sessions (85%). Only some (65%) participants reported that the provided workbook aided goal setting and its use was not frequent. Most (80%) participants used the Fitbit to monitor their physical activity despite only 55% agreeing that it was easy to use and 65% that its use was motivational. Participants indicated increased confidence for physical activity after 12 months; 90% of whom stated that they felt confident continuing with physical activity after the trial. Outcome The PACE-HD intervention was acceptable to HD participants and they felt supported by the intervention therapists. Knowledge gathered in this process evaluation can inform successful implementation, potential causal mechanisms and contextual factors that may affect intervention outcome

Exploring computerised cognitive training as a therapeutic intervention for people with Huntington's disease (CogTrainHD): protocol for a randomised feasibility study

Background Cognitive impairments, especially deficits of executive function, have been well documented as a core and early feature in Huntington’s disease (HD). Cognitive impairments represent considerable burden and can be devastating for people and families affected by HD. Computerised cognitive training interventions that focus on improving executive function present a possible non-pharmacological treatment option. We propose to determine the feasibility, acceptability, and appropriate outcome measures for use in a randomised controlled feasibility study. Methods/design Participants will be randomised into either a computerised cognitive training group or a control group. Those randomised to the training group will be asked to complete a cognitive training intervention based on the HappyNeuron Pro software tasks of executive function, for a minimum of 30 min, three times a week for the 12-week study duration. Participants in the control group will not receive computerised cognitive training but will receive a similar degree of social interaction via equivalent study and home visits. We will explore quantitative outcome measures, including measures of cognitive performance, motor function, questionnaires and semi-structured interviews, as well as magnetic resonance imaging (MRI) measures in a subset of participants. Feasibility will be determined through assessment of recruitment, retention, adherence and acceptability of the intervention. Discussion The results of this study will provide crucial guidance and information regarding the feasibility of conducting a randomised controlled study into computerised cognitive training in HD. This study is crucial for the development of larger definitive randomised controlled trials which are powered to determine efficacy and for the development of future cognitive training programmes for people affected by HD

A randomised feasibility study of computerised cognitive training as a therapeutic intervention for people with Huntington's disease (CogTrainHD)

Background Huntington’s disease (HD) is associated with a range of cognitive deficits including problems with executive function. In the absence of a disease modifying treatment, cognitive training has been proposed as a means of slowing cognitive decline; however, the impact of cognitive training in HD patient populations remains unclear. The CogTrainHD study assessed the feasibility and acceptability of home-based computerised executive function training, for people impacted by HD. Methods Thirty HD gene carriers were recruited and randomised to either executive function training or non-intervention control groups. Participants allocated to the intervention group were asked to complete executive function training three times a week for 30 min for 12 weeks in their own homes. Semi-structured interviews were conducted with participants and friends, family or carers, to determine their views on the study. Results 26 out of 30 participants completed the baseline assessments and were subsequently randomised: 13 to the control group and 13 to the intervention group. 23 of the 30 participants were retained until study completion: 10/13 in the intervention group and 13/13 in the control group. 4/10 participants fully adhered to the executive function training. All participants in the control group 13/13 completed the study as intended. Interview data suggested several key facilitators including participant determination, motivation, incorporation of the intervention into routine and support from friends and family members. Practical limitations, including lack of time, difficulty and frustration in completing the intervention, were identified as barriers to study completion. Conclusions The CogTrainHD feasibility study provides important evidence regarding the feasibility and acceptability of a home-based cognitive training intervention for people with HD. Variable adherence to the cognitive training implies that the intervention is not feasible to all participants in its current form. The study has highlighted important aspects in relation to both the study and intervention design that require consideration, and these include the design of games in the executive function training software, logistical considerations such as lack of time, the limited time participants had to complete the intervention and the number of study visits required. Further studies are necessary before computerised executive function training can be recommended routinely for people with HD

Physical activity self-management and coaching compared to social interaction in huntington disease: results from the ENGAGE-HD randomized, controlled, pilot feasibility trial.

Abstract Background: Self-management and self-efficacy for physical activity is not routinely considered in neurologic rehabilitation. Objective: We assessed feasibility and outcomes of a 14 week physical activity self-management and coaching intervention compared with social contact in Huntington's disease (HD) to inform the design of a future full-scale trial. Design: Assessor blind, multi-site, randomized pilot feasibility trial. Setting: Participants were recruited and assessed at baseline, 16 weeks following randomisation, and then again at 26 weeks in HD specialist clinics with intervention delivery by trained coaches in the participants’ homes. Patients and Intervention: People with HD were allocated to the ENGAGE-HD physical activity coaching intervention or a social interaction intervention. Measurements: Eligibility, recruitment, retention and intervention adherence were determined at 16 weeks. Other outcomes of interest included measures of functional, home and community mobility, self-efficacy, physical activity and disease-specific measures of motor and cognition. Fidelity and costs for both the physical activity and social comparator interventions were established. Results: Forty % (n=46) of eligible patients were enrolled and 22 randomised to the physical intervention and 24 to social intervention. Retention rates in the physical intervention and social intervention were 77% and 92% respectively. Minimum adherence criteria were achieved by 82% of participants in the physical intervention and 100% in the social intervention. There was no indication of between group treatment effects on function, however increases in self-efficacy for exercise and self-reported levels of physical activity in the physical intervention lends support to our pre-defined intervention logic model. Limitations: The use of self-report measures may have introduced bias. Conclusions: An HD physical activity self-management and coaching intervention is feasible and worthy of further investigation.Health and Care Research Wale

Development and Delivery of a Physical Activity Intervention for People With Huntington Disease:Facilitating Translation to Clinical Practice

Background and Purpose: We studied the development and delivery of a 14-week complex physical activity intervention for people with Huntington disease, where detailed information about the intervention was fully embedded in the trial design process. Methods: Intervention Development: The intervention was developed through a series of focus groups. The findings from the focus groups informed the development of a logic model for the physical activity intervention that was broadly consistent with the framework of self-determination theory. Intervention Delivery: Key components underpinning the delivery of the intervention were implemented including a defined coach training program and intervention fidelity assessment methods. Training of coaches (physical therapists, occupational therapists, research nurses, and exercise trainers) was delivered via group and 1:1 training sessions using a detailed coach's manual, and with ongoing support via video calls, and e-mail communication as needed. Detailed documentation was provided to determine costs of intervention development and coach training. Results: Intervention delivery coaches at 8 sites across the United Kingdom participated in the face-to-face training. Self-report checklists completed by each of the coaches indicated that all components of the intervention were delivered in accordance with the protocol. Mean (standard deviation) intervention fidelity scores (n = 15), as measured using a purpose-developed rating scale, was 11 (2.4) (out of 16 possible points). Coaches' perceptions of intervention fidelity were similarly high. The total cost of developing the intervention and providing training was [pounds]30,773 ($47,042 USD). Discussion and Conclusions: An important consideration in promoting translation of clinical research into practice is the ability to convey the detailed components of how the intervention was delivered to facilitate replication if the results are favorable. This report presents an illustrative example of a physical activity intervention, including the development and the training required to deliver it. This approach has the potential to facilitate reproducibility, evidence synthesis, and implementation in clinical practice

HD-DRUM, a tablet-based drumming training application intervention for people with Huntington's Disease: Application development using an integrated knowledge translation framework approach

BackgroundHuntington disease (HD) is a neurodegenerative condition that leads to progressive loss of cognitive-executive and motor functions, largely due to basal ganglia (BG) atrophy. Currently, there are no therapeutic interventions tailored to address executive and motor dysfunction in people with HD. Music-based interventions may aid executive abilities by compensating for impaired BG-reliant timing and rhythm generation using external rhythmic beats. Here, we applied an integrated knowledge translation (IKT) framework to co-design a tablet-based rhythmic drumming training app (HD-DRUM) to stimulate executive and motor abilities in people with HD. ObjectiveThe primary aim was to develop the HD-DRUM app for at-home use that addressed the accessibility needs of people with HD and allowed for the quantification of performance improvements and adherence for controlled clinical evaluation. MethodsThe IKT framework was applied to iteratively refine the design of HD-DRUM. This process involved 3 phases of knowledge user engagement and co-design: a web-based survey of people with HD (n=29) to inform about their accessibility needs, usability testing of tablet-based touch screens as hardware solutions, and usability testing of the design and build of HD-DRUM to meet the identified accessibility needs of people affected by HD and their clinicians (n=12). ResultsThe survey identified accessibility problems due to cognitive and motor control impairments such as difficulties in finding and navigating through information and using PC keyboards and mouses to interact with apps. Tablet-based touch screens were identified as feasible and accessible solutions for app delivery. Key elements to ensure that the app design and build met the needs of people with HD were identified and implemented. These included the facilitation of intuitive navigation through the app using large and visually distinctive buttons; the use of audio and visual cues as training guides; and gamification, positive feedback, and drumming to background music as a means to increase motivation and engagement. The co-design development process resulted in the proof-of-concept HD-DRUM app that is described here according to the Template for Intervention Description and Replication checklist. HD-DRUM can be used at home, allowing the quantification of performance improvements and adherence for clinical evaluation, matching of training difficulty to users’ performance levels using gamification, and future scale-up to reach a wide range of interested users. ConclusionsApplying an IKT-based co-design framework involving knowledge user engagement allowed for the iterative refinement of the design and build of the tablet-based HD-DRUM app intervention, with the aim of stimulating BG-reliant cognitive and motor functions. Mapping the intervention against the Template for Intervention Description and Replication framework to describe complex interventions allowed for the detailed description of the HD-DRUM intervention and identification of areas that required refinement before finalizing the intervention protocol

Applying an integrated knowledge translation framework approach to develop a tablet-based rhythmic movement training intervention for people with Huntington’s disease

Background: Huntington’s Disease (HD) is an incurable neurodegenerative disease that leads to the progressive loss of cognitive and motor functions and mood disturbances, largely due to basal ganglia atrophy. Currently, there are no therapeutic interventions tailored to address cognitive and motor impairment in people with HD. Using an integrated knowledge translation (IKT) framework we developed the HD-DRUM intervention, a tablet-based rhythmic movement training application, with the aim to stimulate basal ganglia reliant cognitive and motor abilities in people with HD. Objective: The primary aim was to develop the HD-DRUM intervention for people with HD. Here we describe the IKT-based process, involving knowledge user engagement, co-design, and iterative usability testing for design refinement. Methods: The IKT framework was applied to iteratively refine the design of the HD-DRUM application. This process involved three phases of knowledge user engagement and co-design including an online survey into the use of digital technologies and usability testing for design refinement in people with HD. The developed HD-DRUM intervention was described according to the template for intervention description and replication (TIDieR) checklist. Results: Barriers and facilitators of using digital technologies were identified. Tablets with touch screens were identified as a feasible and accessible platform to deliver the application. Key elements to ensure that the application design and build met the needs of people with HD were identified. The developed tablet-based HD-DRUM intervention can be used at home and allows the quantification of performance changes, remote monitoring of adherence, matching of training difficulty to users’ performance levels using gamification, and future scaling-up for reaching a wide range of interested users. Conclusions: Applying iterative usability testing within the IKT framework allowed the refinement of the design and build of a novel tablet-based intervention to target cognitive and motor functions in people with HD. Mapping the intervention against the TIDieR framework for describing complex interventions, allowed the detailed description of the HD-DRUM intervention and identification of areas that required refinement prior to finalising the intervention protocol