A highly resilient and zone-based key predistribution protocol for multiphase wireless sensor networks

Pairwise key distribution among the sensor nodes is an essential problem for providing security in Wireless Sensor Networks (WSNs). The common approach for this problem is random key predistribution, which suffers from resiliency issues in case of node captures by adversaries. In the literature, the resiliency problem is addressed by zone-based deployment models that use prior deployment knowledge. Another remedy in the literature, which is for multiphase WSNs, aims to provide self-healing property via periodic deployments of sensor nodes with fresh keys over the sensor field. However, to the best of our knowledge, these two approaches have never been combined before in the literature. In this paper, we propose a zone-based key predistribution approach for multiphase WSNs. Our approach combines the best parts of these approaches and provides self-healing property with up to 9-fold more resiliency as compared to an existing scheme. Moreover, our scheme ensures almost 100% secure connectivity, which means a sensor node shares at least one key with almost all of its neighbors

Probabilistic analysis of cost-effectiveness models: choosing between treatment strategies for gastroesophageal reflux disease

When choosing between mutually exclusive treatment options, it is common to construct a cost-effectiveness frontier on the cost-effectiveness plane that represents efficient points from among the treatment choices. Treatment options internal to the frontier are considered inefficient and are excluded either by strict dominance or by appealing to the principle of extended dominance. However, when uncertainty is considered, options excluded under the baseline analysis may form part of the cost-effectiveness frontier. By adopting a Bayesian approach, where distributions for model parameters are specified, uncertainty in the decision concerning which treatment option should be implemented is addressed directly. The approach is illustrated using an example from a recently published cost-effectiveness analysis of different possible treatment strategies for gastroesophageal reflux disease.It is argued that probabilistic analyses should be encouraged because they have potential to quantify the strength of evidence in favor of particular treatment choices

Justice in New Zealand's Treaty of Waitangi settlement process.

In this paper I examine how the New Zealand government, through the Treaty of Waitangi settlement process, is providing contemporary reparation for historical injustices against Maori tribes. Because historical injustices involve the interactions of cultures over time, justice in New Zealand’s Treaty settlement process is shaped, and constrained, by two key factors: ‘culture’ and ‘time’. First, I make the case that justice in the Treaty settlement process is only that part of justice that is shared by Maori and the New Zealand Crown and that this shared conception of justice is found in the Treaty of Waitangi (the influence of ‘culture’). Following on from this, I show how the Treaty as the shared standard of justice limits the justice in the Treaty settlement process in important ways. Second, I argue that because reparation for historical injustice is made in the present, and works into the future, justice in the Treaty settlement process is not full reparative justice (the influence of ‘time’). Rather, although the justice of the Treaty settlement process is by nature reparative, its scope is limited by contemporary, and prospective, justice concerns. I argue, finally, that the Treaty settlement process reflects a reconciliatory approach to reparative justice where the cultural survival of Maori through restoration of the promises of the Treaty is given greater weight than the provision of full reparation for past wrongs

Bursts of activity in collective cell migration

Dense monolayers of living cells display intriguing relaxation dynamics, reminiscent of soft and glassy materials close to the jamming transition, and migrate collectively when space is available, as in wound healing or in cancer invasion. Here we show that collective cell migration occurs in bursts that are similar to those recorded in the propagation of cracks, fluid fronts in porous media and ferromagnetic domain walls. In analogy with these systems, the distribution of activity bursts displays scaling laws that are universal in different cell types and for cells moving on different substrates. The main features of the invasion dynamics are quantitatively captured by a model of interacting active particles moving in a disordered landscape. Our results illustrate that collective motion of living cells is analogous to the corresponding dynamics in driven, but inanimate, systems

Developing a distributed electronic health-record store for India

The DIGHT project is addressing the problem of building a scalable and highly available information store for the Electronic Health Records (EHRs) of the over one billion citizens of India