Discrete element models of soil-geogrid interaction

Geogrids are the geosynthetics of choice for soil reinforcement applications. To evaluate the efficiency of geogrid reinforcement, several methods are used including field tests, laboratory tests and numerical modeling. Field studies consume long period of time and conducting these investigations may become highly expensive because of the need for real-size structures. Laboratory studies present also significant difficulties: large-size testing machines are required to accommodate realistic geogrid designs. The discrete element method (DEM) may be used as a complementary tool to extend physical testing databases at lower cost. Discrete element models do not require complex constitutive formulations and may be fed with particle scale data (size, strength, shape) thus reducing the number offree calibration parameters. Discrete element models also are well suited to problems in which large displacements are present, such as geogrid pullout. This paper reviews the different approaches followed to model soil-geogrid interaction in DEM and presents preliminary results from pull-out conditions.Peer ReviewedPostprint (author's final draft

Data in the garden: a framework for exploring provocative prototypes as part of research in the wild

Research in the Wild (RITW) typically involves the deployment of technology in a setting, using the methodology of ‘probing’ contexts, to change behaviour or enhance community practice. This way of conducting HCI research is becoming an increasingly popular approach. To help in this endeavour, Rogers and Marshall [28] present an overarching framework that considers the different aspects involved. As part of the framework, they stress the importance of the design of the technology to be deployed. However, they do not detail how researchers should go about this. Here, we propose how to fill this gap: by providing a more explicit and principled rationale as part of RITW, presenting a method for accomplishing this, and reporting a case study about community gardening that uses a provocative prototype

Active Learning Techniques to Build Problem Solving Skills in Chemistry Students

Through the introduction of Team-Based Learning problem classes and a ‘Purple Pens’ feedback intervention in which students write their own feedback on a mixed formative and summative class test we have been able to observe a significant increase in exam performance in Foundation Year students. Both Science and Health students improved their exam performance by 13% and 11% respectively and both interventions were positively received by students

Undergraduate Nurses’ and Midwives’ Participation and Satisfaction with Live Interactive Webcasts

INTRODUCTION: E-Learning methods such as webcasting are being used increasingly in healthcare education, including that of nurses and midwives. Webcasting means live synchronous broadcasting over the internet, where students participate simultaneously in text ‘chat room’ interactive discussions when logged on to a webpage where they can see and hear a presentation such as a PowerPoint lecture, a list of other participants, and access ‘chat rooms’. AIMS: This paper reports student participation and satisfaction with the use of webcasting in a third year undergraduate nursing and midwifery research methods module in one higher education institution faculty of health and social work in the southwest of England, with students from distributed geographical locations. MATERIALS AND METHODS: Students chose either webcasts or face-to-face lectures. Following each of the four webcasts, a web-based evaluation questionnaire was administered in a cross-sectional survey design. RESULTS: Two thirds of students took part in webcasts and found them to be an acceptable teaching and learning strategy. Travel and cost savings were noted through not travelling to the main university campus, and these were statistically significantly correlated with students’ perception of gaining from the module and their overall satisfaction with webcasting. Across the four webcasts 5446 purposeful messages were posted indicating engagement with the material under study. CONCLUSIONS AND RECOMMENDATIONS: Webcasting is an effective teaching and learning strategy which is popular with students, allows remote access to teaching and learning, and offers time and cost savings to students. Further research is required to investigate the educational potential of this new technology

Phase 1 pilot study of e-mail support for people with long term conditions using the Internet.

BACKGROUND: Use of the Internet for people with Long Term Conditions (LTCs) can have a positive effect on knowledge, social support, behavioural and clinical outcomes, yet there is concern that a 'digital divide' prevents some patients from benefitting. While some patients do not have access to the Internet, others that do may still lack expertise or the confidence to make full use of it. The aim of this pilot study was to develop an intervention and test methods for a definitive randomised controlled trial (RCT) of anonymous personal online email support for patients in this latter group. METHODS: Recruitment success was evaluated by the number and appropriateness of participants recruited. A personalised e-health support intervention was developed. The provisional primary outcome was the extent to which the Internet affected the participants' confidence in dealing with their LTC. Primary outcome, seven process measures and two secondary outcomes measures were evaluated for completeness of data and sensitivity to detect changes. RESULTS: Thirty nine participants were recruited, 29 after personally receiving a leaflet, seven via email advertising, and three via leaflets left in waiting areas. Most participants (61%) were aged over 60. The majority (21/38) rated themselves as experienced Internet users although only 5/38 had used discussion forums for their LTC. Piloting the intervention identified support needed as: (i) technical help with some websites, (ii) advice about issues such as anonymity, (iii) help in judging information quality, (iv) identification of relevant information (via 'Information Prescriptions'), (v) motivational support to try new sites. Attrition was fairly high: 20/39 completed follow up questionnaires. Three process measures showed ceiling effects and two had too many missing values to be useable. CONCLUSION: E-health support is a promising way of addressing the problems faced by older generation e-health seekers. Face-to-face leaflet distribution recruited sufficient numbers but additional locations other than hospital should be tried to recruit Internet novices with LTCs. An RCT is feasible and necessary to evaluate the potential benefits of anonymous email support. Our methods could be used by other researchers studying Internet use by people with LTCs

Laminar dynamics of high amplitude beta bursts in human motor cortex

Motor cortical activity in the beta frequency range is one of the strongest and most studied movement-related neural signals. At the single trial level, beta band activity is often characterized by transient, high amplitude, bursting events rather than slowly modulating oscillations. The timing of these bursting events is tightly linked to behavior, suggesting a more dynamic functional role for beta activity than previously believed. However, the neural mechanisms underlying beta bursts in sensorimotor circuits are poorly understood. To address this, we here leverage and extend recent developments in high precision MEG for temporally resolved laminar analysis of burst activity, combined with a neocortical circuit model that simulates the biophysical generators of the electrical currents which drive beta bursts. This approach pinpoints the generation of beta bursts in human motor cortex to distinct excitatory synaptic inputs to deep and superficial cortical layers, which drive current flow in opposite directions. These laminar dynamics of beta bursts in motor cortex align with prior invasive animal recordings within the somatosensory cortex, and suggest a conserved mechanism for somatosensory and motor cortical beta bursts. More generally, we demonstrate the ability for uncovering the laminar dynamics of event-related neural signals in human non-invasive recordings. This provides important constraints to theories about the functional role of burst activity for movement control in health and disease, and crucial links between macro-scale phenomena measured in humans and micro-circuit activity recorded from animal models

Identification of a neuropeptide precursor protein that gives rise to a "cocktail" of peptides that bind Cu(II) and generate metal-linked dimers

The Transparency document associated with this article can be found,in online version.This work was supported by a Leverhulme Trust grant (RPG-2013-351) awarded to MRE and National Science Foundation (USA) grant awards DEB 1036416, 1036358, 1036366, and 1036368

Validity and reliability of an iPhone App to assess time, velocity and leg power during a sit-to-stand functional performance test.

No procede.The purposes of this study were: (i) Analyze the concurrent validity and reliability of an iPhone App for measuring time, velocity and power during a single sit-to-stand (STS) test compared with measurements recorded from a force plate; and (ii) Evaluate the relationship between the iPhone App measures with age and functional performance. Forty-eight healthy individuals (age range: 26-81 years) were recruited. All participants completed a STS test on a force plate with the movement recorded on an iPhone 6 at 240 frames-per-second. Functional ability was also measured using isometric handgrip strength and self-paced walking time tests. Intraclass correlation coefficients (ICC), Pearson's correlation coefficient, Cronbach's alpha (α) and Bland-Altman plots with 95% confidence intervals (CI) were used to test validity and reliability between instruments. The results showed a good agreement between all STS measurement variables; time (ICC=0.864, 95%CI=0.77-0.92; α=0.926), velocity (ICC=0.912, 95%CI=0.85-0.95; α=0.953) and power (ICC=0.846, 95%CI=0.74-0.91; α=0.917) with no systematic bias between instruments for any variable analyzed. STS time, velocity and power derived from the iPhone App show moderate to strong associations with age (|r|=0.63-0.83) and handgrip strength (|r|=0.4-0.64) but not the walking test. The results of this study identify that this iPhone App is reliable for measuring STS and the derived values of time, velocity and power shows strong associations with age and handgrip strength.No.Actividad Física y DeporteTerapia y Rehabilitació

Narrowing the Range of Future Climate Projections Using Historical Observations of Atmospheric CO2

This is the final version. Available from American Meteorological Society via the DOI in this recordUncertainty in the behavior of the carbon cycle is important in driving the range in future projected climate change. Previous comparisons of model responses with historical CO2 observations have suggested a strong constraint on simulated projections that could narrow the range considered plausible. This study uses a new 57-member perturbed parameter ensemble of variants of an Earth system model for three future scenarios, which 1) explores a wider range of potential climate responses than before and 2) includes the impact of past uncertainty in carbon emissions on simulated trends. These two factors represent a more complete exploration of uncertainty, although they lead to a weaker constraint on the range of future CO2 concentrations as compared to earlier studies. Nevertheless, CO2 observations are shown to be effective at narrowing the distribution, excluding 30 of 57 simulations as inconsistent with historical CO2 changes. The perturbed model variants excluded are mainly at the high end of the future projected CO2 changes, with only 8 of the 26 variants projecting RCP8.5 2100 concentrations in excess of 1100 ppm retained. Interestingly, a minority of the high-end variants were able to capture historical CO2 trends, with the large-magnitude response emerging later in the century (owing to high climate sensitivities, strong carbon feedbacks, or both). Comparison with observed CO2 is effective at narrowing both the range and distribution of projections out to the mid-twenty-first century for all scenarios and to 2100 for a scenario with low emissions.This work was supported by the Joint U.K. DECC/DEFRA Met Office Hadley Centre Climate Programme (GA01101). Chris Jones’s contribution was supported by the CRESCENDO project under the European Union's Horizon 2020 research and innovation programme, Grant Agreement 641816. Jo House was supported by a Leverhulme Early Career Fellowship and EU FP7 Project LUC4C (603542). Stephen Sitch was supported by the EU FP7 through Project LUC4C (GA603542)