Light (about 3,000 foot-candles) neither increased nor decreased the sink strength of young, rapidly expanding leaves of Phaseolus vulgaris L. cv. Black Valentine, as measured by the comparative rates of import of (14)C-labeled photosynthates by sink leaves in the light versus dark in short term experiments. Although irradiated sink leaves accumulated more (14)C activity, the difference was ful...

This paper presents a novel MAC protocol for Wireless Sensor Networks (WSN)s designated Tone-Propagated MAC (TP-MAC). This protocol is specially suited for early warning and tracking applications, where sensor nodes generate sporadic asynchronous traffic (mainly consisting of uplink alert messages and downlink control messages) with stringent latency requirements. This protocol aims to maximize...

This paper presents Tone-Propagated MAC (TP-MAC), a novel MAC protocol for Wireless Sensor Networks (WSN)s, specially suited for early warning and tracking applications, where the traffic generated by sensor nodes (mainly alert messages) is sporadic but has stringent latency requirements. This protocol aims to maximize energy-efficiency while minimizing latency in source-to-sink and sink-to-sou...

We consider the problem of constructing a multicast tree that connects a group of source nodes to a group of sink nodes (receivers) and minimizes the maximum end-to-end delay between any pair of source/sink nodes. This is known as the minimum eccentricity multicast tree problem, and is directly related to the quality of service requirements of real multipoint applications. We deal directly with...

The problem of computing performability probabilities in stochastic PERT and ow networks is studied when the network is \minimally designed" to withstand any two component failures. Polynomial-time algorithms to compute performability when the network is planar| the nonplanar versions being NP-hard | solve related \two-path subset" problems. Given an acyclic graph with weights on the arcs, the ...

In the single-sink buy-at-bulk network design problem we are given a subset of source nodes in a weighted undirected graph: each source node wishes to send a given amount of flow to a sink node. Moreover, a set of cable types is given, each characterized by a cost per unit length and by a capacity: the ratio cost/capacity decreases from small to large cables by economies of scale. The problem i...

We discuss the problem of ranking objects sampled from in general r ordered categories. A ranking model for this kind of data can be visualized as a (layered) ranking graph having a single source and sink, and the number of paths connecting source and sink is seen as a ranking-based performance measure. In this article we consider learning such a graph as a structured output in a convex optimiz...

Given an edgeor vertex-weighted graph or digraph and a list of source-sink pairs, the minimum multicut problem consists in selecting a minimum weight set of edges or vertices whose removal leaves no path from each source to the corresponding sink. This is a classical NPhard problem, and we show that the edge version becomes tractable in bounded tree-width graphs if the number of source-sink pai...

Mathematical models of predator-prey interactions in a patchy landscape are used to explore the evolution of dispersal into sink habitats. When evolution proceeds at a single trophic level (i.e., either prey or predator disperses), three evolutionary outcomes are observed. If predator-prey dynamics are stable in source habitats, then there is an evolutionarily stable strategy (ESS) correspondin...

To clarify polarity, topography, and time course of recognition memory ERP old/new effects during matched visual and auditory continuous word recognition tasks, unrestricted temporal PCA jointly analyzed stimulus- and response-locked, reference-free current source densities (31-channel, N=40). Randomization tests provided unbiased statistics for complete factor topographies. Old/new left pariet...