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Data broadcast is a fundamental operation in wireless sensor networks (WSNs). The existence of wireless interference makes it nontrivial to design a minimum-latency broadcast scheme, which is known to be NP-hard. Existing works all assume strict time synchronization and provide centralized TDMA scheduling algorithms. However, WSNs in practice are more likely to be distributed asynchronous systems. In this paper, we investigate the problem of data broadcast with minimum latency for distributed asynchronous WSNs. To this end, we propose a Distributed Asynchronous Broadcast (DAB) algorithm which crucially leverages an elaborately optimized carrier-sensing range together with collision-backoff schemes to coordinate the transmissions among the nodes on a predetermined broadcast backbone. Theoretical analysis shows that DAB is order-optimal and achieves constant factor approximation to the optimal delay. We then conduct extensive simulations to evaluate the practical capability of DAB in asynchronous WSNs and the results corroborate our theoretical analysis. [ABSTRACT FROM AUTHOR]

Summary: In recent years, the process of the programmed cell death has gained much interest because it has important pathophysiological consequences contributing to the deletion of unwanted cells in the vessel wall, loss of pulmonary smooth muscle cells and therefore in reversing the pulmonary pressure. For the reason that most patients with pulmonary hypertension present with limited reversibility with vasodilators, antiremodeling approach for treatment appears to be feasible. Induction or enhancement of vascular smooth muscle cells apoptosis may be targeted to develop novel therapeutic approaches for pulmonary vascular remodeling in patients with pulmonary hypertension. This review summarizes the current mechanisms, investigate the roles and provide novel insights into the potential therapeutic value of apoptosis in the pulmonary artery remodeling of pulmonary hypertension. [Copyright &y& Elsevier]