When monitoring spatial phenomena with wireless sensor networks, selecting the best sensor placements is a fundamental task. Not only should the sensors be informative, but they should also be able to communicate efficiently. In this paper, we present a data-driven approach that addresses the three central aspects of this problem: measuring the predictive quality of a set of sensor locations (regardless of whether sensors were ever placed at these locations), predicting the communication cost involved with these placements, and designing an algorithm with provable quality guarantees that optimizes the NP-hard tradeoff. Specifically, we use data from a pilot deployment to build non-parametric probabilistic models called Gaussian Processes (GPs) both for the spatial phenomena of interest and for the spatial variability of link qualities, which allows us to estimate predictive power and communication cost of unsensed locations. Surprisingly, uncertainty in the representation of link qualities plays an important role in estimating communication costs. Using these models, we present a novel, polynomial-time, data-driven algorithm, pSPIEL, which selects Sensor Placements at Informative and cost-Effective Locations. Our approach exploits two important properties of this problem: submodularity, formalizing the intuition that adding a node to a small deployment can help more than adding a node to a large deployment; and locality, under which nodes that are far from each other provide almost independent information. Exploiting these properties, we prove strong approximation guarantees for our pSPIEL approach. We also provide extensive experimental validation of this practical approach on several real-world placement problems, and built a complete system implementation on 46 Tmote Sky motes, demonstrating significant advantages over existing methods.

Sexual segregation is widespread throughout the animal kingdom. Although a number of hypotheses have been proposed to account for observed patterns, the generality of the mechanisms remains debated. One possible reason for this is the focus on segregation patterns in large mammals such as ungulates, where the majority of studies are descriptions of a single population. Here, we present the results of a cross‐population comparison of patterns of sexual segregation in the Trinidadian guppy, Poecilia reticulata. We relate observed patterns to experimental quantification of predation risk and sexual harassment of females by males in eight populations. We find that the degree of segregation increases with predation risk, with deeper waters becoming increasingly female biased. Furthermore, we observed that levels of male harassment are lower in deeper water but only in those rivers that contain major guppy predators. We conclude that sexual segregation in guppies is consistent with the predation risk hypothesis: sexual segregation results from a combination of predation risk driving males (the more vulnerable sex) into less risky habitats and females gaining benefits of reduced sexual harassment by remaining in high‐predation environments.

The pathogenicity of 45 isolates of Ascochyta pinodes, Ascochyta pisi and Phoma medicaginis var. pinodella collected in South Australia has been examined on selected pea lines. Twenty-six isolates of A. pinodes were differentiated into 15 pathotypes, 15 isolates of A. pisi were differentiated into 13 pathotypes, and four isolates of P. medicaginis var. pinodella into one pathotype. Adequate sources of resistance were identified against all the pathotypes excepting pathotypes 1 of A. pinodes and A. pisi. The necessity to breed for broadly based resistance to Ascochyta species is discussed.

Nine Namurian clay bands retrieved from boreholes in the northern part of the Pennine Basin are, on the basis of their petrography, mineralogy and geochemistry, shown to be volcanic in origin and are therefore bentonites. The bentonites, which have a fragmental texture, are normally graded and show rare preservation of shard textures, representing vitric tuff deposits that have been altered subsequently to clay‐dominated horizons. Crystals are a minor component of the bentonites, but biotite, in particular, is concentrated at the base of the beds. A clay mineral assemblage of mixed‐layer illite–smectite with subordinate kaolinite identifies most of the samples as K‐bentonites, but kaolinite dominates two samples that can be classed as tonsteins. Temporal variation of salinity within the depositional basin is suggested to explain these different clay assemblages. The major element geochemistry of the bentonites reflects their clay mineralogy and the compositions of diagenetic minerals present, the latter including pyrite, carbonates and hydroxyapatite. Enrichment of the bentonites in some trace elements (including Ba, Sr, Pb, Cu and Ni) can be related to the presence of the diagenetic minerals, but the extent to which the elements are added from external sources as opposed to being redistributed within the ash is unclear. Immobile trace element systematics suggest a rhyodacite/dacite composition for the original ash and derivation from the collision of plates, this being supported by evidence provided by the rare earth elements (REE) in one group of samples. However, in another group of samples, variations in REE concentrations may be caused by mobility of these elements during alteration. The chemistry of the Namurian bentonites contrasts markedly with that of the local Carboniferous volcanics but is comparable, in some respects, with one group of Westphalian tonsteins, although the latter are more rhyolitic in character. It is suggested that the Namurian bentonites and the Westphalian tonsteins of acid affinities originated from volcanic activity associated with a destructive plate margin in the Variscan externides and that the observed compositional trend may reflect magma evolution possibly related to the progressive east–west closure.

AUTOSAR is a recent specification initiative which focuses on a model-driven architecture like methodology for automotive applications. However, needed engineering steps, or how-to-come from a logical to a technical architecture respectively implementation, are not well supported by tools, yet. In contrast, SystemC offers a comprehensive way to simulate, analyze, and verify software. Furthermore, it is even able to take the timing behavior of underlying hardware and communication paths into account. Already at a first glance, there are many similarities with respect to the modeling structure between the both concepts. Therefore, this paper discusses approaches on how to use SystemC during the design process of AUTOSAR-conform systems. PV untimed structural com. CDMA CP untimed P2P communication CC cycle accurate communication CAN COMMUNICATION REFINEMENT FLOW CPT timed P2P communication timing approx. communication CAN PVT CP untimed parallel processes COMPUTATION REFINEMENT FLOW CC cycle accurate computation CAN RTOS RTOS CPU CPU CPT timed parallel processes scheduled processes approximate timing RTOS CPU Model PVT PV untimed scheduled processes RTOS PV untimed structural com. CDMA CP untimed P2P communication CC cycle accurate communication CAN COMMUNICATION REFINEMENT FLOW CPT timed P2P communication timing approx. communication CAN PVT PV untimed structural com. CDMA PV untimed structural com. CDMA untimed structural com. CDMA CDMA CP untimed P2P communication CP untimed P2P communication CC cycle accurate communication CAN CC cycle accurate communication CAN CAN COMMUNICATION REFINEMENT FLOW CPT timed P2P communication CPT timed P2P communication timing approx. communication CAN PVT timing approx. communication CAN timing approx. communication CAN CAN PVT CP