During the last ice age, much of North America far south as 40°N was covered by glaciers (Hewitt 2000). About 20,000 years ago, as the glaciers retreated, the hydrologic landscape changed dramatically creating waterways for fish dispersal. The number of populations responsible for recolonization and the regions from which they recolonized are unknown for many freshwater fishes living in New Eng...

Through the new method for automatic extraction of a tidal network from topographic or bathymetric fields described in a companion paper [Fagherazzi et al., this issue], we analyze the morphology of aggregated patterns that we observe in nature in different tidal environments. Specifically, we define, on the basis of a hydrodynamic analysis, a procedure for watershed delineation and for the ide...

This paper describes long-term hydrologic response within a rapidly developing watershed in the western suburbs of Washington, DC, within the Chesapeake Bay drainage basin. Data consist of up to 24 years of observed rainfall, basin discharge, and land use/land cover (LULC) from four headwater basins of the Occoquan River in northern Virginia. Basin outlets are monitored for storm and nonstorm f...

The hypotheses that beta diversity should increase with decreasing latitude and increase with spatial extent of a region have rarely been tested based on a comparative analysis of multiple datasets, and no such study has focused on stream insects. We first assessed how well variability in beta diversity of stream insect metacommunities is predicted by insect group, latitude, spatial extent, alt...

BACKGROUND The prognostic significance of multiple draining basins is controversial in melanoma because analyses have not adequately controlled for standard prognostic variables. We hypothesized that an analysis based on prognostically matched pairs of patients with multiple versus single drainage basins would clarify any independent role of basin number. STUDY DESIGN We identified patients i...

The effects of erosion, avalanching and random precipitation are captured in a simple stochastic partial differential equation for modelling the evolution of river networks. Our model leads to a self-organized structured landscape and to abstraction and piracy of the smaller tributaries as the evolution proceeds. An algebraic distribution of the average basin areas and a power law relationship ...

BACKGROUND Aberrant lymphatic drainage is believed to contribute to the high recurrence rate of head and neck melanomas. The purpose of this study was to identify the clinical significance of unexpected lymphatic drainage patterns. METHODS A single institution retrospective analysis was performed of middle-aged and older men (mean age, 66.2 years; range, 41-87 years) who underwent successful ...

â â â  in the last years, have been accelerated increased the damages of landslides by natural and anthropogenic factors. one of the main solutions to decrease landslide hazards is avoid from prone areas. for this purpose, it is necessary to prepare the landslide susceptibility map. in this research, after field studies in the ilam dam basin, nine factors including slope gradient, aspect, eleva...