PAMPA in the wild:a real-life evaluation of a lightweight ad-hoc broadcasting family

Broadcast is one of the core building blocks of many services deployed on ad-hoc wireless networks, such as Mobile Ad-Hoc Networks (MANETs) or Wireless Sensor Networks (WSNs). Most broadcast protocols are however only ever evaluated using simulations, which have repeatedly been shown to be unreliable, and potentially misleading. In this paper, we seek to go beyond simulations, and consider the particular case of PAMPA, a promising family of wireless broadcast algorithms for ad-hoc and wireless networks. We report on our efforts to further our experimental understanding of PAMPA, and present the first ever characterisation of the PAMPA family on a real deployment. Here it has to deal with real network problems such as node, message and sending failure. Our experiments show that the standard PAMPA algorithm out-performs all other protocols in the family, with a delivery ratio consistently around 75%, and a retransmission ratio as low as 44%, for a failure-free run. We use this opportunity to reflect on our findings and lessons learnt when moving from simulations to actual experimentsab

Repurposing web analytics to support the IoT

Internet of Things analytics engines are complex to use and often optimized for a single domain or limited to proprietary data. A prototype system shows that existing Web analytics technologies can successfully be repurposed for IoT applications including sensor monitoring and user engagement tracking

Brane decay of a (4+n)-dimensional rotating black hole: spin-0 particles

In this work, we study the `scalar channel' of the emission of Hawking radiation from a (4+n)-dimensional, rotating black hole on the brane. We numerically solve both the radial and angular part of the equation of motion for the scalar field, and determine the exact values of the absorption probability and of the spheroidal harmonics, respectively. With these, we calculate the particle, energy and angular momentum emission rates, as well as the angular variation in the flux and power spectra -- a distinctive feature of emission during the spin-down phase of the life of the produced black hole. Our analysis is free from any approximations, with our results being valid for arbitrarily large values of the energy of the emitted particle, angular momentum of the black hole and dimensionality of spacetime. We finally compute the total emissivities for the number of particles, energy and angular momentum and compare their relative behaviour for different values of the parameters of the theory.Comment: 24 pages, 13 figure

Presumptive treatment of fever cases as malaria: help or hindrance for malaria control?

BACKGROUND: Malaria incidence has been reported to be falling in several countries in sub-Saharan Africa in recent years. This fall appears to have started before the widespread introduction of insecticide-treated nets. In the new era of calls to eliminate and eradicate malaria in sub-Saharan Africa, exploring possible causes for this fall seem pertinent. PRESENTATION OF THE HYPOTHESIS: The authors explore an argument that presumptive treatment of fever cases as malaria may have played a role in reducing transmission of malaria by the prophylactic effect of antimalarials and their widespread use. This strategy, which is already in practise is termed Opportunistic Presumptive Treatment (OPT). TESTING THE HYPOTHESIS: Further comparison of epidemiological indicators between areas with OPT and more targeted treatment is required. If data suggest a benefit of OPT, combining long acting antimalarials that have an anti-gametocyticidal activity component plus using high levels of vector control measures may reduce transmission, prevent resistant strains spreading and be easily implemented. IMPLICATIONS OF THE HYPOTHESIS: OPT is practised widely by presumptive treatment of fever in health facilities and home management of fever. Improving diagnosis using rapid diagnostic tests and thus reducing the number of doses of antimalarials given may have counter intuitive effects on transmission in the context of elimination of malaria in high to moderate transmission settings

Rehabilitation following rotator cuff repair: A multi-centre pilot & feasibility randomised controlled trial (RaCeR)

Objective: To evaluate the feasibility of a multi-centre randomised controlled trial to compare the clinical and cost-effectiveness of early patient-directed rehabilitation versus standard rehabilitation following surgical repair of the rotator cuff of the shoulder. Design: Two-arm, multi-centre pilot and feasibility randomised controlled trial. Setting: Five National Health Service hospitals in England. Participants: Adults (n = 73) with non-traumatic rotator cuff tears scheduled for repair were recruited and randomly allocated remotely prior to surgery. Interventions: Early patient-directed rehabilitation (n = 37); advised to remove their sling as soon as able and move as symptoms allow. Standard rehabilitation (n = 36); sling immobilisation for four weeks. Measures: (1) Randomisation of 20% or more eligible patients. (2) Difference in time out of sling of 40% or more between groups. (3) Follow-up greater than 70%. Results: 73/185 (39%) potentially eligible patients were randomised. Twenty participants were withdrawn, 11 due to not receiving rotator cuff repair. The between-group difference in proportions of participants who exceeded the cut-off of 222.6 hours out of the sling was 50% (80% CI = 29%, 72%), with the early patient-directed rehabilitation group reporting greater time out of sling. 52/73 (71%) and 52/53 (98%) participants were followed-up at 12 weeks when withdrawals were included and excluded respectively. Eighteen full-thickness re-tears were reported (early patient-directed rehabilitation = 7, standard rehabilitation = 11). Five serious adverse events were reported. Conclusion: A main randomised controlled trial is feasible but would require allocation of participants following surgery to counter the issue of withdrawal due to not receiving surgery

Pentoxifylline as an adjunct therapy in children with cerebral malaria

<p>Abstract</p> <p>Background</p> <p>Pentoxifylline (PTX) affects many processes that may contribute to the pathogenesis of severe malaria and it has been shown to reduce the duration of coma in children with cerebral malaria. This pilot study was performed to assess pharmacokinetics, safety and efficacy of PTX in African children with cerebral malaria.</p> <p>Methods</p> <p>Ten children admitted to the high dependency unit of the Kilifi District Hospital in Kenya with cerebral malaria (Blantyre coma score of 2 or less) received quinine plus a continuous infusion of 10 mg/kg/24 hours PTX for 72 hours. Five children were recruited as controls and received normal saline instead of PTX. Plasma samples were taken for PTX and tumour necrosis factor (TNF) levels. Blantyre Coma Score, parasitemia, hematology and vital signs were assessed 4 hourly.</p> <p>Results</p> <p>One child (20%) in the control group died, compared to four children (40%) in the PTX group. This difference was not significant (p = 0.60). Laboratory parameters and clinical data were comparable between groups. TNF levels were lower in children receiving PTX.</p> <p>Conclusions</p> <p>The small sample size does not permit definitive conclusions, but the mortality rate was unexpectedly high in the PTX group.</p

Garotas de loja, história social e teoria social [Shop Girls, Social History and Social Theory]

Shop workers, most of them women, have made up a significant proportion of Britain’s labour force since the 1850s but we still know relatively little about their history. This article argues that there has been a systematic neglect of one of the largest sectors of female employment by historians and investigates why this might be. It suggests that this neglect is connected to framings of work that have overlooked the service sector as a whole as well as to a continuing unease with the consumer society’s transformation of social life. One element of that transformation was the rise of new forms of aesthetic, emotional and sexualised labour. Certain kinds of ‘shop girls’ embodied these in spectacular fashion. As a result, they became enduring icons of mass consumption, simultaneously dismissed as passive cultural dupes or punished as powerful agents of cultural destruction. This article interweaves the social history of everyday shop workers with shifting representations of the ‘shop girl’, from Victorian music hall parodies, through modernist social theory, to the bizarre bombing of the Biba boutique in London by the Angry Brigade on May Day 1971. It concludes that progressive historians have much to gain by reclaiming these workers and the service economy that they helped create

A Real Deployment to Investigate PAMPA and Smart Gossip

A broadcasting protocol for a wireless sensor network needs to be simple, lightweight and robust. The main goal of a broadcasting protocol is to gain the best propagation of a message for the low- est energy consumption. This is hard to achieve as typically sensor networks have low energy reserves and turbulent wireless transmis- sion, making them extremely prone to failure. PAMPA and Smart Gossip are the two broadcast protocols compared in this paper, their performances in previous simulations are amongst the best in the current research area. This is determined by how successfully they deliver packets to each node on the network and more importantly how little energy they consume while doing this. It is also important to evaluate how they perform when they are subject to real network problems such as node, message and sending failure. Before ei- ther protocol can be recommended for deployment, it is important to find how well they perform when deployed on a real network. By comparing the two protocols on a real network we can find the most lightweight, efficient and robust protocol when used in real life. This paper discusses the benefits and drawbacks of the two protocols, presents an in-depth evaluation and establishes which is the most capable. The results of this paper conclude that PAMPA was by far the most effective broadcast protocol; it managed to de- liver a high percentage of messages to each node on the network and managed to keep its message retransmissions and therefore its energy consumption very low

Stakeholding: Confusion or Utopia? Mapping the conceptual terrain

The paper has three main objectives. The first aim is to examine and clarify the burgeoning stakeholder literature that currently seeks to inform management practice, corporate governance and public policy with particular emphasis on the UK. We do this by continuing the process of clarification started by Donaldson and Preston (1995), focusing mainly on the political and practitioner literature generated within the UK. We begin this task by setting out a critique of stakeholding and develop this by using four key themes of enquiry. First, we examine stakeholding's conceptual confusion; second, we outline and develop criticsm of its underlying pluralist assumptions; third, we consider the problems of implementation; and finally, we assess some of the key arguments concerning its potential impact on business performance and competitiveness. The second aim is to develop and examine the central criticisms of stakeholding from both the neo-liberal and Marxist/radical perspectives. By so doing we identify the key theoretical and practical issues which stakeholder proponents must address if they are to convince sceptics of the model's validity. The third aim is to develop a conceptual framework capable of illustrating the different stakeholder perspectives and assumptions on which they are based. This consists of five continuums: the first locates authors on a left-right political continuum; the second distinguishes between those authors who use stakeholding primarily for analysis and those who use it to formulate and prescribe specific courses of action; the third differentiates between intrinsic (good in itself) and instrumental (means to an end) motives; the fourth identifies the various levels of proposed intervention; and the fifth illustrates the different degrees of enforcement advocated. We believe that this framework provides a clear illustration of our arguments and serves as a useful instrument for clarifying the stakeholder concept. In addition, it is used to position or map the work of key authors within the stakeholder debate and we believe it may provide a more coherent basis for future research and debate