On Energy Efficiency and Delay Minimization in Reactive Protocols in Wireless Multi-hop Networks

In Wireless Multi-hop Networks (WMhNs), routing protocols with energy efficient and delay reduction techniques are needed to fulfill users demands. In this paper, we present Linear Programming models (LP_models) to assess and enhance reactive routing protocols. To practically examine constraints of respective LP_models over reactive protocols, we select AODV, DSR and DYMO. It is deduced from analytical simulations of LP_models in MATLAB that quick route repair reduces routing latency and optimizations of retransmission attempts results efficient energy utilization. To provide quick repair, we enhance AODV and DSR. To practically examine the efficiency of enhanced protocols in different scenarios of WMhNs, we conduct simulations using NS- 2. From simulation results, enhanced DSR and AODV achieve efficient output by optimizing routing latencies and routing load in terms of retransmission attempts

Performance Analysis of Hierarchical Routing Protocols in Wireless Sensor Networks

This work focusses on analyzing the optimization strategies of routing protocols with respect to energy utilization of sensor nodes in Wireless Sensor Network (WSNs). Different routing mechanisms have been proposed to address energy optimization problem in sensor nodes. Clustering mechanism is one of the popular WSNs routing mechanisms. In this paper, we first address energy limitation constraints with respect to maximizing network life time using linear programming formulation technique. To check the efficiency of different clustering scheme against modeled constraints, we select four cluster based routing protocols; Low Energy Adaptive Clustering Hierarchy (LEACH), Threshold Sensitive Energy Efficient sensor Network (TEEN), Stable Election Protocol (SEP), and Distributed Energy Efficient Clustering (DEEC). To validate our mathematical framework, we perform analytical simulations in MATLAB by choosing number of alive nodes, number of dead nodes, number of packets and number of CHs, as performance metrics.Comment: NGWMN with 7th IEEE International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA 2012), Victoria, Canada, 201

HEER: Hybrid Energy Efficient Reactive Protocol for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) consist of numerous sensors which send sensed data to base station. Energy conservation is an important issue for sensor nodes as they have limited power.Many routing protocols have been proposed earlier for energy efficiency of both homogeneous and heterogeneous environments. We can prolong our stability and network lifetime by reducing our energy consumption. In this research paper, we propose a protocol designed for the characteristics of a reactive homogeneous WSNs, HEER (Hybrid Energy Efficient Reactive) protocol. In HEER, Cluster Head(CH) selection is based on the ratio of residual energy of node and average energy of network. Moreover, to conserve more energy, we introduce Hard Threshold (HT) and Soft Threshold (ST). Finally, simulations show that our protocol has not only prolonged the network lifetime but also significantly increased stability period.Comment: 2nd IEEE Saudi International Electronics, Communications and Photonics Conference (SIECPC 13), 2013, Riyadh, Saudi Arabi

Evaluating Impact of Mobility on Wireless Routing Protocols

In this paper, we evaluate, analyze, and compare the impact of mobility on the behavior of three reactive protocols (AODV, DSR, DYMO) and three proactive protocols (DSDV, FSR, OLSR) in multi-hop wireless networks. We take into account throughput, end-to-end delay, and normalized routing load as performance parameters. Based upon the extensive simulation results in NS-2, we rank all of six protocols according to the performance parameters. Besides providing the interesting facts regarding the response of each protocol on varying mobilities and speeds, we also study the trade-offs, the routing protocols have to make. Such as, to achieve throughput, a protocol has to pay some cost in the form of increased end-to-end delay or routing overhead

Secondary prevention of fractures after hip fracture:a qualitative study of effective service delivery

There is variation in how services to prevent secondary fractures after hip fracture are delivered and no consensus on best models of care. This study identifies healthcare professionals' views on effective care for the prevention of these fractures. It is hoped this will provide information on how to develop services.Hip fracture patients are at high risk of subsequent osteoporotic fractures. Whilst fracture prevention services are recommended, there is variation in delivery and no consensus on best models of care. This study aims to identify healthcare professionals' views on effective care for prevention of secondary fracture after hip fracture.Forty-three semi-structured interviews were undertaken with healthcare professionals involved in delivering fracture prevention across 11 hospitals in one English region. Interviews explored views on four components of care: (1) case finding, (2) osteoporosis assessment, (3) treatment initiation, and (4) monitoring and coordination. Interviews were audio-recorded, transcribed, anonymised and coded using NVivo software.Case finding: a number of approaches were discussed. Multiple methods ensured there was a 'backstop' if patients were overlooked. Osteoporosis assessment: there was no consensus on who should conduct this. The location of the dual energy X-ray absorptiometry (DXA) scanner influenced the likelihood of patients receiving a scan. Treatment initiation: it was felt this was best done in inpatients rather request initiation in the post-discharge/outpatients period. Monitoring (adherence): adherence was a major concern, and participants felt more monitoring could be conducted by secondary care. Coordination of care: participants advocated using dedicated coordinators and formal and informal methods of communication. A gap between primary and secondary care was identified and strategies suggested for addressing this.A number of ways of organising effective fracture prevention services after hip fracture were identified. It is hoped that this will help professionals identify gaps in care and provide information on how to develop services

Psychological therapy for mood instability within bipolar spectrum disorder: a single-arm feasibility study of a dialectical behaviour therapy-informed approach

This is the final version. Available on open access from BMC via the DOI in this recordAvailability of data and materials: The datasets generated and analysed during the current study are not publicly available to protect participant confidentiality, but are available from the corresponding author on reasonable request, subject to any applicable regulatory approvals for secondary use of the data.Background: We sought to evaluate the acceptability of a psychological therapy programme (Therapy for Inter-episode Mood Variability in Bipolar Disorder (ThrIVe-B)) for individuals with ongoing bipolar mood instability and the feasibility and acceptability of potential trial procedures. We also evaluated the performance of clinical and process outcome measures and the extent to which the programme potentially represents a safe and effective intervention. Method: We conducted an open (uncontrolled) trial in which 12 individuals with a bipolar spectrum diagnosis commenced the ThrIVe-B programme after completing baseline assessments. The programme comprised 16 group skills training sessions plus individual sessions and a supporting smartphone application. Follow-up assessments were at therapy end-point and 6 months post-treatment. Results: Nine participants completed treatment. Ten provided end-of-treatment data; of these, nine were satisfied with treatment. Interviews with participants and clinicians indicated that the treatment was broadly feasible and acceptable, with suggestions for improvements to content, delivery and study procedures. Exploration of change in symptoms was consistent with the potential for the intervention to represent a safe and effective intervention. Conclusions: Conducting further evaluation of this approach in similar settings is likely to be feasible, whilst patient reports and the pattern of clinical change observed suggest this approach holds promise for this patient group. Future research should include more than one study site and a comparison arm to address additional uncertainties prior to a definitive trial. Trial registration: Trial Registration: ClinicalTrials.gov NCT02637401; registered 22.12.15 (retrospectively registered)

Secular trends in the initiation of therapy in secondary fracture prevention in Europe : a multi-national cohort study including data from Denmark, Catalonia, and the United Kingdom

Altres ajuts: UCB funded this study. All analyses were conducted independently by the academic researchers involved. MKJ is supported by the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC).This paper demonstrates a large post-fracture anti-osteoporosis treatment gap in the period 2005 to 2015. The gap was stable in Denmark at around 88-90%, increased in Catalonia from 80 to 88%, and started to increase in the UK towards the end of our study. Improved post-fracture care is needed. Patients experiencing a fragility fracture are at high risk of subsequent fractures, particularly within the first 2 years after the fracture. Previous studies have demonstrated that only a small proportion of fracture patients initiate therapy with an anti-osteoporotic medication (AOM), despite the proven fracture risk reduction of such therapies. The aim of this paper is to evaluate the changes in this post-fracture treatment gap across three different countries from 2005 to 2015. This analysis, which is part of a multinational cohort study, included men and women, aged 50 years or older, sustaining a first incident fragility fracture. Using routinely collected patient data from three administrative health databases covering Catalonia, Denmark, and the United Kingdom, we estimated the treatment gap as the proportion of patients not treated with AOM within 1 year of their first incident fracture. A total of 648,369 fracture patients were included. Mean age 70.2-78.9 years; 22.2-31.7% were men. In Denmark, the treatment gap was stable at approximately 88-90% throughout the 2005 to 2015 time period. In Catalonia, the treatment gap increased from 80 to 88%. In the UK, an initially decreasing treatment gap-though never smaller than 63%-was replaced by an increasing gap towards the end of our study. The gap was more pronounced in men than in women. Despite repeated calls for improved secondary fracture prevention, an unacceptably large treatment gap remains, with time trends indicating that the problem may be getting worse in recent years. The online version of this article (10.1007/s00198-020-05358-4) contains supplementary material, which is available to authorized users