BACKGROUND AND AIMS Solving relationships of recently diverged taxa, poses a challenge due to shared polymorphism and weak reproductive barriers. Multiple lines of evidence are needed to identify independently evolving lineages. This is especially true of long-lived species with large effective population sizes, and slow rates of lineage sorting. North American pines are an interesting group to...

Variations in the frequency and extent of hybridization among mixed populations located in the same contact zone provide natural laboratories for the study of extrinsic reproductive isolation maintaining species integrity. In this study, we examined the pattern of hybridization between L. japonicum and L. stellipilum among mixed populations in different localities of a contact zone. The genetic...

Eco-environmental stress refers to the pressure borne by the environment in sustaining the pre-existing non-industrialized state and/or in counteracting adverse impacts caused by natural and human factors. The present article introduces the concept, research progress, and method for assessing eco-environmental stress. An eco-environmental stress index (ESI) is established to assess the eco-envi...

Hybrid zones have yielded considerable insight into many evolutionary processes, including speciation and the maintenance of species boundaries. Presented here are analyses from a hybrid zone that occurs among three salamanders -Plethodon jordani, Plethodon metcalfi and Plethodon teyahalee- from the southern Appalachian Mountains. Using a novel statistical approach for analysis of non-clinal, m...

We examined the distribution of uncultured Planctomycetes phylotypes along depth profiles spanning the redox gradient of the Black Sea suboxic zone to gain insight into their respective ecological niches. Planctomycetes phylogeny correlated with depth and chemical profiles, implying similar metabolisms within phylogenetic groups. A suboxic zone sample was split into > 30 and < 30 μm fractions t...

agro-ecological zoning is one of the effective tools for assining land to suitable land use.the study areawith16618ha islocatedin abyek area inqazvin province. in totally 43 agro- ecoloical zones were distinguished by combining maps of isohyet, isotherm, length of growing periodand agro-edaphic zones. based on above information a land suitability was produced for the study area and prediction o...

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...