Complex processes related to biotic and abiotic forces can impose limitations to assembly and composition of plant communities. Quantifying the effects of these constraints on plant functional traits across environmental gradients, and among communities, remains challenging. We define ecological constraint (Ci ) as the combined, limiting effect of biotic interactions and environmental filtering...

Natural populations consist of phenotypically diverse individuals that exhibit variation in their demographic parameters and intra- and inter-specific interactions. Recent experimental work indicates that such variation can have significant ecological effects. However, ecological models typically disregard this variation and focus instead on trait means and total population density. Under what ...

In this paper we will continue the study of p-closed spaces. This class of spaces is strictly placed between the class of strongly compact spaces and the class of quasi-Hclosed spaces. We will provide new characterizations of p-closed spaces and investigate their relationships with some other classes of topological spaces.

What should and should not be considered an affordance is still an open issue. At the 2002 North American meeting of the International Society for Ecological Psychology, a symposium was held concerning this topic. The articles in this special issue are expanded versions of the papers presented at that symposium. To set the stage for those discussions, this article presents an analysis of the ev...

Abstract Story segmentation is an important problem in multimedia indexing and retrieval and includes detection of commercials as one of its component problems. Commercials appear regularly in television data and are usually treated as noise. Hence, filtering of commercials is an important task. This paper presents a system that detects and filters commercials from broadcast news data. While pr...

In this paper, we illustrate that combining ecological data with subsample data in situations in which a generalized linear model (GLM) is appropriate provides two main benefits. First, by including the individual level subsample data, the biases associated with ecological inference in GLMs can be eliminated. Second, available ecological data can be used to design optimal subsampling schemes, s...

Convincing arguments for using critical realism as an underpinning for theories of IT-associated organizational change have appeared in the IS literature. A central task in developing such theories is to uncover the generative mechanisms by which IT is implicated in organizational change processes, but to do so, we must explain how critical realism’s concept of generative mechanisms applies in ...