72 research outputs found
A Ferroelectric Tunnel Junction-based Integrate-and-Fire Neuron
Event-based neuromorphic systems provide a low-power solution by using
artificial neurons and synapses to process data asynchronously in the form of
spikes. Ferroelectric Tunnel Junctions (FTJs) are ultra low-power memory
devices and are well-suited to be integrated in these systems. Here, we present
a hybrid FTJ-CMOS Integrate-and-Fire neuron which constitutes a fundamental
building block for new-generation neuromorphic networks for edge computing. We
demonstrate electrically tunable neural dynamics achievable by tuning the
switching of the FTJ device
A 120dB Programmable-Range On-Chip Pulse Generator for Characterizing Ferroelectric Devices
Novel non-volatile memory devices based on ferroelectric thin films represent a promising emerging technology that is ideally suited for neuromorphic applications. The physical switching mechanism in such films is the nucleation and growth of ferroelectric domains. Since this has a strong dependence on both pulse width and voltage amplitude, it is important to use precise pulsing schemes for a thorough characterization of their behavior. In this work, we present an on-chip 120 dB programmable range pulse generator, that can generate pulse widths ranging from 10 ns to 10 ms ± 2.5% which eliminates the RLC bottleneck in the device characterisation setup. We describe the pulse generator design and show how the pulse width can be tuned with high accuracy, using Digital to Analog converters. Finally, we present experimental results measured from the circuit, fabricated using a standard 180 nm CMOS technology
Perceptions of extended-release buprenorphine injections for opioid use disorder among people who regularly use opioids in Australia
2019 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction Aims: To examine perceptions of extended-release (XR) buprenorphine injections among people who regularly use opioids in Australia. Design: Cross-sectional survey prior to implementation. XR-buprenorphine was registered in Australia in November 2018. Setting: Sydney, Melbourne and Hobart. Participants. A total of 402 people who regularly use opioids interviewed December 2017 to March 2018. Measurements: Primary outcome concerned the proportion of participants who believed XR-buprenorphine would be a good treatment option for them, preferred weekly versus monthly injections and perceived advantages/disadvantages of XR-buprenorphine. Independent variables concerned the demographic characteristics and features of current opioid agonist treatment (OAT; medication-type, dose, prescriber/dosing setting, unsupervised doses, out-of-pocket expenses and travel distance). Findings: Sixty-eight per cent [95% confidence interval (CI) = 63-73%] believed XR-buprenorphine was a good treatment option for them. They were more likely to report being younger [26-35 versus \u3e 55 years; odds ratio (OR) = 3.16, 95% CI = 1.12-8.89; P = 0.029], being female (OR = 1.67, 95% CI = 1.04-2.69; P = 0.034), \u3c 10 years school education (OR = 1.87, 95% CI = 1.12-3.12; P = 0.016) and past-month heroin (OR = 1.81, 95% CI = 1.15-2.85; P = 0.006) and methamphetamine use (OR = 1.90, 95% CI = 1.20-3.01; P = 0.006). Fifty-four per cent reported no preference for weekly versus monthly injections, 7% preferred weekly and 39% preferred monthly. Among OAT recipients (n = 255), believing XR-buprenorphine was a good treatment option was associated with shorter treatment episodes (1-2 versus ≥ 2 years; OR = 3.93, 95% CI = 1.26-12.22; P = 0.018), fewer unsupervised doses (≤ 8 doses past-month versus no take-aways; OR = 0.50; 95% CI = 0.27-0.93; P = 0.028) and longer travel distance (≥ 5 versus \u3c 5 km; OR = 2.10, 95% CI = 1.20-3.65; P = 0.009). Sixty-nine per cent reported \u27no problems or concerns\u27 with potential differences in availability, flexibility and location of XR-buprenorphine. Conclusions: Among regular opioid users in Australia, perceptions of extended-release buprenorphine as a good treatment option are associated with being female, recent illicit drug use and factors relating to the (in)convenience of current opioid agonist treatment
A cluster randomized-controlled trial of a community mobilization intervention to change gender norms and reduce HIV risk in rural South Africa: study design and intervention
Abstract Background Community mobilization (CM) interventions show promise in changing gender norms and preventing HIV, but few have been based on a defined mobilization model or rigorously evaluated. The purpose of this paper is to describe the intervention design and implementation and present baseline findings of a Cluster Randomized Controlled Trial (RCT) of a two-year, theory-based CM intervention that aimed to change gender norms and reduce HIV risk in rural Mpumalanga province, South Africa. Methods Community Mobilizers and volunteer Community Action Teams (CATs) implemented two-day workshops, a range of outreach activities, and leadership engagement meetings. All activities were mapped onto six theorized mobilization domains. The intervention is being evaluated by a randomized design in 22 communities (11 receive intervention). Cross-sectional, population-based surveys were conducted with approximately 1,200 adults ages 18–35 years at baseline and endline about two years later. Conclusions This is among the first community RCTs to evaluate a gender transformative intervention to change norms and HIV risk using a theory-based, defined mobilization model, which should increase the potential for impact on desired outcomes and be useful for future scale-up if proven effective. Trial registration ClinicalTrials.gov NCT0212953
Randomised controlled trial of welfare rights advice accessed via primary health care: pilot study [ISRCTN61522618]
BACKGROUND: Little research has directly evaluated the impact of increasing financial or material resources on health. One way of assessing this lies with assisting people to obtain full welfare benefit entitlements. In 2000–1, 2.3 million pensioners were living in poverty in the UK and estimates suggest that around one million do not claim the financial support to which they are entitled. The effectiveness of welfare rights advice services delivered via primary health care to promote health and reduce health inequalities is unknown. METHODS: The main objectives of this study were to assess the feasibility and acceptability of a randomised controlled trial of welfare rights advice in a community setting and identify appropriate health and social outcome measures in order to plan a definitive trial. This was a single blind, community-based, pilot randomised controlled trial. 126 men and women aged 60 years and over, recruited from 4 general practices in Newcastle upon Tyne, UK, participated. The intervention comprised a structured welfare rights assessment followed by active assistance with welfare benefit claims over the following 24 months. The control group received the intervention after a six month delay. A range of socio-economic, health, behavioural and psycho-social outcomes were measured. RESULTS: 126 out of 400 people invited agreed to participate and 109 were followed up at 24 months. Both the intervention and research procedures were feasible and acceptable to participants and professionals involved. 68 (58%) of all participants received a welfare benefit award (31 financial, 16 non-financial and 21 both). Median time to receipt of benefits from initial assessment was 14 (range 1 to 78) weeks and median financial award was £55 (€81, $98) per household per week. There was little evidence of health-related differences between groups or over time, which could be due to limitations of the study design. CONCLUSION: Modification of the study design, including selection of study participants, timing of interventions and length of follow up are recommended for a definitive trial. More appropriate health and psycho-social outcome measures relevant to the elderly population should be sought, particularly focussing on those issues highlighted in the accompanying qualitative study
Protocol for Birmingham Atrial Fibrillation Treatment of the Aged study (BAFTA): a randomised controlled trial of warfarin versus aspirin for stroke prevention in the management of atrial fibrillation in an elderly primary care population.
Background
Atrial fibrillation (AF) is an important independent risk factor for stroke. Randomised controlled trials have shown that this risk can be reduced substantially by treatment with warfarin or more modestly by treatment with aspirin. Existing trial data for the effectiveness of warfarin are drawn largely from studies in selected secondary care populations that under-represent the elderly.
The Birmingham Atrial Fibrillation Treatment of the Aged (BAFTA) study will provide evidence of the risks and benefits of warfarin versus aspirin for the prevention of stroke for older people with AF in a primary care setting.
Study design
A randomised controlled trial where older patients with AF are randomised to receive adjusted dose warfarin or aspirin. Patients will be followed up at three months post-randomisation, then at six monthly intervals there after for an average of three years by their general practitioner. Patients will also receive an annual health questionnaire.
1240 patients will be recruited from over 200 practices in England. Patients must be aged 75 years or over and have AF. Patients will be excluded if they have a history of any of the following conditions: rheumatic heart disease; major non-traumatic haemorrhage; intra-cranial haemorrhage; oesophageal varices; active endoscopically proven peptic ulcer disease; allergic hypersensitivity to warfarin or aspirin; or terminal illness. Patients will also be excluded if the GP considers that there are clinical reasons to treat a patient with warfarin in preference to aspirin (or vice versa).
The primary end-point is fatal or non-fatal disabling stroke (ischaemic or haemorrhagic) or significant arterial embolism. Secondary outcomes include major extra-cranial haemorrhage, death (all cause, vascular), hospital admissions (all cause, vascular), cognition, quality of life, disability and compliance with study medication
Assessing the effectiveness of Enhanced Psychological Care for patients with depressive symptoms attending cardiac rehabilitation compared with treatment as usual (CADENCE): A pilot cluster randomised controlled trial
© 2018 The Author(s). Background: Around 17% of people attending UK cardiac rehabilitation programmes have depression. Optimising psychological wellbeing is a rehabilitation goal, but provision of psychological care is limited. We developed and piloted an Enhanced Psychological Care (EPC) intervention embedded within cardiac rehabilitation, aiming to test key areas of uncertainty to inform the design of a definitive randomised controlled trial (RCT) and economic evaluation. Methods: An external pilot randomised controlled trial (RCT) randomised eight cardiac rehabilitation teams (clusters) to either usual care of cardiac rehabilitation provision (UC), or EPC in addition to UC. EPC comprised mental health care coordination and patient-led behavioural activation with nurse support. Adults eligible for cardiac rehabilitation following an acute coronary syndrome and identified with new-onset depressive symptoms during an initial nurse assessment were eligible. Measures were performed at baseline and 5- and 8-month follow-ups and compared between EPC and UC. Team and participant recruitment and retention rates, and participant outcomes (clinical events, depression, anxiety, health-related quality of life, patient experiences, and resource use) were assessed. Results: Eight out of twenty teams were recruited and randomised. Of 614 patients screened, 55 were eligible and 29 took part (5%, 95% CI 3 to 7% of those screened), with 15 patient participants cluster randomised to EPC and 14 to UC. Nurse records revealed that 8/15 participants received the maximum number of EPC sessions offered; and 4/15 received no sessions. Seven out of fifteen EPC participants were referred to another NHS psychological service compared to none in UC. We followed up 27/29 participants at 5 months and 17/21 at 8 months. The mean difference (EPC minus UC) in depressive symptoms (Beck Depression Inventory) at follow-up (adjusting for baseline score) was 1.7 (95% CI - 3.8 to 7.3; N = 26) at 5 months and 4.4 (95% CI - 1.4 to 10.2; N = 17) at 8 months. Discussion: While valued by patients and nurses, organisational and workload constraints are significant barriers to EPC implementation. There remains a need to develop and test new models of psychological care within cardiac rehabilitation. Our study offers important data to inform the design of future trials of similar interventions
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