Local auxin concentration maxima promote organ initiation in the plant shoot meristem, but how auxin peaks are formed has remained unclear. A new study proposes a cellular Matthew effect, where auxin is pumped into those cells that have higher concentrations.

Previous studies investigated fMRI-guided repetitive Transcranial Magnetic Stimulation (rTMS) as an alternative treatment for auditory verbal hallucinations (AVH). This tailor-made treatment focuses at directing the rTMS coil to the location where hallucinatory activation is maximal, as identified with fMRI scans of individual patients. For the effective use of such treatment it is important to...

The determination of distillation boundaries for four-component mixtures that exhibit azeotropy is studied. It is shown that these distillation boundaries correspond to local maxima in surface areas under conditions of Levi-Civita parallelism. An extension of the optimization methodology given in Lucia and Taylor is used to determine local maxima in surface areas by repeatedly computing maximum...

In this work, we derive a general class of multistep composite elementary landscapes and present the first non-trivial lower (upper) bounds on local minima (maxima) associated with elementary landscapes. © 2008 Elsevier Ltd. All rights reserved.

We use a geometric description for deadlocks occuring in scheduling problems for concurrent systems to construct a partial order and hence a directed graph, in which the local maxima correspond to deadlocks. Algorithms finding deadlocks are described and assessed.

In [40], it was shown that the following singularly perturbed Dirichlet problem 2∆u− u+ |u|p−1u = 0, in Ω, u = 0 on ∂Ω has a nodal solution u which has the least energy among all nodal solutions. Moreover, it is shown that u has exactly one local maximum point P 1 with a positive value and one local minimum point P 2 with a negative value and, as → 0, φ(P 1 , P 2 ) → max (P1,P2)∈Ω×Ω φ(P1, P2), ...

Proof of Proposition 1: The off-equilibrium path beliefs imply that any price offer below M(w) is definitely rejected, and any price offer above M(w̄) is definitely accepted. Any price offer v between M(w) and M(w̄) leads F to believe that w = M−1(v), and he is indifferent between accepting and rejecting it, making it optimal for him to randomize his acceptance decision. Finally, when the randomi...

Abstract In this paper we describe I-Subdue, an extension to the Subdue graph-based data mining system. I-Subdue operates over sequentially received relational data to incrementally discover the most representative substructures. The ability to incrementally refine discoveries from serially acquired data is important for many applications, particularly as computer systems become more integrated...

A general formulation of discrete optimization is to maximize a given function f : D → R over a discrete (finite) domain D. In general, of course, this problem may require |D| probes to f . One approach to making optimization more tractable is to be satisfied with finding a local maximum, i.e., a point at which f attains a value larger than all “neighboring” points, for some definition of neigh...

We show that two popular discounted reward natural actor-critics, NAC-LSTD and eNAC, follow biased estimates of the natural policy gradient. We derive the first unbiased discounted reward natural actor-critics using batch and iterative approaches to gradient estimation and prove their convergence to globally optimal policies for discrete problems and locally optimal policies for continuous prob...