8 research outputs found

    Towards Quantum Belief Propagation for LDPC Decoding in Wireless Networks

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    We present Quantum Belief Propagation (QBP), a Quantum Annealing (QA) based decoder design for Low Density Parity Check (LDPC) error control codes, which have found many useful applications in Wi-Fi, satellite communications, mobile cellular systems, and data storage systems. QBP reduces the LDPC decoding to a discrete optimization problem, then embeds that reduced design onto quantum annealing hardware. QBP's embedding design can support LDPC codes of block length up to 420 bits on real state-of-the-art QA hardware with 2,048 qubits. We evaluate performance on real quantum annealer hardware, performing sensitivity analyses on a variety of parameter settings. Our design achieves a bit error rate of 10−810^{-8} in 20 μ\mus and a 1,500 byte frame error rate of 10−610^{-6} in 50 μ\mus at SNR 9 dB over a Gaussian noise wireless channel. Further experiments measure performance over real-world wireless channels, requiring 30 μ\mus to achieve a 1,500 byte 99.99%\% frame delivery rate at SNR 15-20 dB. QBP achieves a performance improvement over an FPGA based soft belief propagation LDPC decoder, by reaching a bit error rate of 10−810^{-8} and a frame error rate of 10−610^{-6} at an SNR 2.5--3.5 dB lower. In terms of limitations, QBP currently cannot realize practical protocol-sized (e.g.,\textit{e.g.,} Wi-Fi, WiMax) LDPC codes on current QA processors. Our further studies in this work present future cost, throughput, and QA hardware trend considerations

    Family-led rehabilitation after stroke in India (ATTEND): a randomised controlled trial

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    Background Most people with stroke in India have no access to organised rehabilitation services. The effectiveness of training family members to provide stroke rehabilitation is uncertain. Our primary objective was to determine whether family-led stroke rehabilitation, initiated in hospital and continued at home, would be superior to usual care in a low-resource setting. Methods The Family-led Rehabilitation after Stroke in India (ATTEND) trial was a prospectively randomised open trial with blinded endpoint done across 14 hospitals in India. Patients aged 18 years or older who had had a stroke within the past month, had residual disability and reasonable expectation of survival, and who had an informal family-nominated caregiver were randomly assigned to intervention or usual care by site coordinators using a secure web-based system with minimisation by site and stroke severity. The family members of participants in the intervention group received additional structured rehabilitation training—including information provision, joint goal setting, carer training, and task-specific training—that was started in hospital and continued at home for up to 2 months. The primary outcome was death or dependency at 6 months, defined by scores 3–6 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) as assessed by masked observers. Analyses were by intention to treat. This trial is registered with Clinical Trials Registry-India (CTRI/2013/04/003557), Australian New Zealand Clinical Trials Registry (ACTRN12613000078752), and Universal Trial Number (U1111-1138-6707). Findings Between Jan 13, 2014, and Feb 12, 2016, 1250 patients were randomly assigned to intervention (n=623) or control (n=627) groups. 33 patients were lost to follow-up (14 intervention, 19 control) and five patients withdrew (two intervention, three control). At 6 months, 285 (47%) of 607 patients in the intervention group and 287 (47%) of 605 controls were dead or dependent (odds ratio 0·98, 95% CI 0·78–1·23, p=0·87). 72 (12%) patients in the intervention group and 86 (14%) in the control group died (p=0·27), and we observed no difference in rehospitalisation (89 [14%]patients in the intervention group vs 82 [13%] in the control group; p=0·56). We also found no difference in total non-fatal events (112 events in 82 [13%] intervention patients vs 110 events in 79 [13%] control patients; p=0·80). Interpretation Although task shifting is an attractive solution for health-care sustainability, our results do not support investment in new stroke rehabilitation services that shift tasks to family caregivers, unless new evidence emerges. A future avenue of research should be to investigate the effects of task shifting to health-care assistants or team-based community care

    Evaluation of an anti-stigma campaign related to common mental disorders in rural India:a mixed methods approach

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    Background Stigma related to mental health is a major barrier to help-seeking resulting in a large treatment gap in low- and middle-income countries (LMIC). This study assessed changes in knowledge, attitude and behaviour, and stigma related to help-seeking among participants exposed to an anti-stigma campaign. Method The campaign, using multi-media interventions, was part of the SMART Mental Health Project, conducted for 3 months, across 42 villages in rural Andhra Pradesh, in South India. Mixed-methods evaluation was conducted in two villages using a pre-post design. Results A total of 1576 and 2100 participants were interviewed, at pre- and post-intervention phases of the campaign. Knowledge was not increased. Attitudes and behaviours improved significantly (p < 0.01). Stigma related to help-seeking reduced significantly (p < 0.05). Social contact and drama were the most beneficial interventions identified during qualitative interviews. Conclusion The results showed that the campaign was beneficial and led to improvement of attitude and behaviours related to mental health and reduction in stigma related to help-seeking. Social contact was the most effective intervention. The study had implications for future research in LMIC

    Low-density parity-check codes for 40-gb/s optical transmission systems

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    Evaluation of an anti-stigma campaign related to common mental disorders in rural India: a mixed methods approach

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    Background Stigma related to mental health is a major barrier to help-seeking resulting in a large treatment gap in low- and middle-income countries (LMIC). This study assessed changes in knowledge, attitude and behaviour, and stigma related to help-seeking among participants exposed to an anti-stigma campaign. Method The campaign, using multi-media interventions, was part of the SMART Mental Health Project, conducted for 3 months, across 42 villages in rural Andhra Pradesh, in South India. Mixed-methods evaluation was conducted in two villages using a pre-post design. Results A total of 1576 and 2100 participants were interviewed, at pre- and post-intervention phases of the campaign. Knowledge was not increased. Attitudes and behaviours improved significantly (p &lt; 0.01). Stigma related to help-seeking reduced significantly (p &lt; 0.05). Social contact and drama were the most beneficial interventions identified during qualitative interviews. Conclusion The results showed that the campaign was beneficial and led to improvement of attitude and behaviours related to mental health and reduction in stigma related to help-seeking. Social contact was the most effective intervention. The study had implications for future research in LMIC

    Cardiovascular disease risk and comparison of different strategies for blood pressure management in rural India

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    Background: Non-optimal blood pressure (BP) levels are a major cause of disease burden globally. We describe current BP and treatment patterns in rural India and compare different approaches to BP lowering in this setting.Methods: All individuals aged ≥40 years from 54 villages in a South Indian district were invited and 62,194 individuals (84%) participated in a cross-sectional study. Individual 10-year absolute cardiovascular disease (CVD) risk was estimated using WHO/ISH charts. Using known effects of treatment, proportions of events that would be averted under different paradigms of BP lowering therapy were estimated.Results: After imputation of pre-treatment BP levels for participants on existing treatment, 76·9% (95% confidence interval, 75.7–78.0%), 5·3% (4.9–5.6%), and 17·8% (16.9–18.8%) of individuals had a 10-year CVD risk defined as low (&lt; 20%), intermediate (20–29%), and high (≥30%, established CVD, or BP &gt; 160/100 mmHg), respectively. Compared to the 19.6% (18.4–20.9%) of adults treated with current practice, a slightly higher or similar proportion would be treated using an intermediate (23·2% (22.0–24.3%)) or high (17·9% (16.9–18.8%) risk threshold for instituting BP lowering therapy and this would avert 87·2% (85.8–88.5%) and 62·7% (60.7–64.6%) more CVD events over ten years, respectively. These strategies were highly cost-effective relative to the current practice.Conclusion: In a rural Indian community, a substantial proportion of the population has elevated CVD risk. The more efficient and cost-effective clinical approach to BP lowering is to base treatment decisions on an estimate of an individual’s short-term absolute CVD risk rather than with BP based strategy
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