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Energy efficiency is of the utmost importance in wireless sensor networks. The family of Low-Power-Listening MAC protocols was proposed to reduce one form of energy dissipation-idle listening, a radio state for which the energy consumption cannot be neglected. Low-Power-Listening MAC protocols are characterized by a duty cycle: a node probes the channel(More)
Many recent advances in MAC protocols for wireless sensor networks have been proposed to reduce idle listening, an energy wasteful state of the radio. Low-Power-Listening (LPL) protocols transmit packets for U s (the "interlistening interval"), thereby, allowing nodes to sleep for long periods of time between channel probes. The interlistening interval as(More)
We report that the genes abc, yaeC, and yaeE comprise metD, an Escherichia coli locus encoding a DL-methionine uptake system. MetD is an ABC transporter with Abc the ATPase, YaeE the permease, and YaeC the likely substrate binding protein. Expression of these genes is regulated by L-methionine and MetJ, a common repressor of the methionine regulon. We(More)
Despite the power of sequencing and of emerging high-throughput technologies to collect data rapidly, the definitive functional characterization of unknown genes still requires biochemical and genetic analysis in case-by-case studies. This often involves the deletion of target genes and phenotypic characterization of the deletants. We describe here(More)
Many recent advances in MAC protocols for wireless sensor networks propose to reduce idle listening. Sending nodes transmit long preambles or repeated advertisements for upcoming packets, thereby allowing their neighbors to have low duty cycles. As these " channel probing MAC protocols " impose a significant drain on the transmitting node, the schedule used(More)
Protocols for wireless sensor networks (WSNs) are very diverse. Reflecting this diversity, no single protocol architecture for WSNs dominates: programmers often modify the legacy-architecture to fit their set of protocols in the stack. However, there exists desirable goals for a sensor network architecture: modularity, flexibility and universality. At the(More)
Low-power-listening MAC protocols were designed to reduce idle listening, a major source of energy consumption in energy starved wireless sensor networks. Low-power-listening is a MAC strategy that allows nodes to sleep for t i s (the " inter-listening " time) when there is no activity concerning them. It follows that a node has to occupy the medium for at(More)
Cross-layer designs have received much attention recently. While not as general as layered architectures, they prove to be more tunable and energy-efficient in many scenarios. This flexibility can be exploited by a middleware whose principal task is to adapt quality of service provided by the network to the application's needs using the pre-defined(More)
— Recent work on cross-layer schemes have demonstrated the need for a unifying wireless sensor networks architecture that provides more integration than the standard layered OSI protocol stack yet is flexible enough to support different applications. In this paper, we propose a new information-sharing architecture for sensor networks that can support(More)