Exploiting Layered Multi-Path Routing Protocols to avoid void hole regions for reliable data delivery and efficient energy management for IoT-enabled underwater WSNs

The key concerns to enhance the lifetime of IoT-enabled Underwater Wireless Sensor Networks (IoT-UWSNs) are energy-efficiency and reliable data delivery under constrained resource. Traditional transmission approaches increase the communication overhead, which results in congestion and affect the reliable data delivery. Currently, many routing protocols have been proposed for UWSNs to ensure reliable data delivery and to conserve the node’s battery with minimum communication overhead (by avoiding void holes in the network). In this paper, adaptive energy-efficient routing protocols are proposed to tackle the aforementioned problems using the Shortest Path First (SPF) with least number of active nodes strategy. These novel protocols have been developed by integrating the prominent features of Forward Layered Multi-path Power Control One (FLMPC-One) routing protocol, which uses 2-hop neighbor information, Forward Layered Multi-path Power Control Two (FLMPC-Two) routing protocol, which uses 3-hop neighbor information and ’Dijkstra’ algorithm (for shortest path selection). Different Packet Sizes (PSs) with different Data Rates (DRs) are also taken into consideration to check the dynamicity of the proposed protocols. The achieved outcomes clearly validate the proposed protocols, namely: Shortest Path First using 3-hop neighbors information (SPF-Three) and Breadth First Search with Shortest Path First using 3-hop neighbors information (BFS-SPF-Three). Simulation results show the effectiveness of the proposed protocols in terms of minimum Energy Consumption (EC) and Required Packet Error Rate (RPER) with a minimum number of active nodes at the cost of affordable delay

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

Collaborative mobile sink sojourn time optimization scheme for cluster-based wireless sensor networks

Wireless sensor networks (WSNs) have grown excessively due to their various applications and low installation cost. One of the design challenges of the WSNs is to balance the energy consumption among sensor nodes, which results in enhanced network lifetime. In the past few years, several mobile sink (MS)-based schemes exclusively focus on determining the optimal sojourn time of MS to balance the energy consumption among cluster heads (CH). However, most of them are evaluated under unpredictable mobility pattern. Although they significantly improve the network lifetime, however, unpredictable mobility pattern imposes extra overheads on the network. Therefore, collaborative mobile sink sojourn time optimization (CMS2TO) scheme is proposed in this paper. The CMS2TO aims to optimize the sojourn time of MS in each cluster in order to achieve a balanced lifetime of CHs belonging to different layers of the network. The main contribution of the CMS2TO is to utilize a collaborative mechanism in order to determine the optimal sojourn time of MS in each cluster. In fact, in the proposed scheme, the CHs belonging to other layers cooperate in calculating the sojourn time of MS at the residence cluster. Based on experimental results, the proposed CMS2TO enhances the network performance in terms of different performance evaluation metrics

Energy-efficient mobile-sink Sojourn location optimization scheme for consumer home networks

With the fast development of wireless communication and semiconductor devices, home networking has gained considerable attention in the past few years. In Wireless Sensor Networks (WSNs), Sensing coverage is known as one of the most important standards in evaluating the performance of WSNs. The sensor nodes may have failures due to energy depletion during their service life which leads to incomplete coverage of the sensing area and coverage holes in the network which results in reducing the network performance. Therefore, designing an energy-efficient solution to prevent the coverage holes is vital. Employing Mobile Sink (MS) is a popular technique to enhance the energy efficiency of the network. Furthermore, sojourn location optimization is one of the main design issues of mobility based schemes. However, to the best of our knowledge, most of existing sojourn location optimization-based schemes are specially designed for homogeneous networks and much less attention has been devoted to optimizing this parameter in heterogeneous networks. Therefore, the aim behind this paper is to optimize the sojourn location of MS in a heterogeneous home network, which results in improving the coverage time and the performance of the network. Based on the experimental results, the scheme proposed in this paper remarkably improves the balanced energy consumption, which leads to enhanced network lifetime and performance