Populations of species occupying large geographic ranges are often phenotypically diverse as a consequence of variation in selective pressures and drift. This applies to attributes involved in mate choice, particularly when both geographic range and breeding biology overlap between related species. This condition may lead to interference of mating signals, which would in turn promote reproducti...

Experimental analyses of river networks(1) have shown clear examples of behavior analogous to critical phenomena characterized by the absence of a single well-defined length scale reflected in a power-law behavior of various quantities. A fundamental question that arises from these observations is whether, in analogy with conventional critical phenomena, one may fruitfully classify this behavio...

River networks evolve as migrating drainage divides reshape river basins and change network topology by capture of river channels. We demonstrate that a characteristic metric of river network geometry gauges the horizontal motion of drainage divides. Assessing this metric throughout a landscape maps the dynamic states of entire river networks, revealing diverse conditions: Drainage divides in t...

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. [1] The morphologic transition from complex impact craters, to peak-ring basins, and to multi-ring basins has been ...

Valley networks are mapped from mosaics composed of 100 m/pixel THEMIS images for 8 sites in Martian highlands. The sites are subdivided into individual drainage basins using 500 m/pixel DEMs co-registered with image mosaics. Terrain parameters are calculated for each basin with area > 10 km. Drainage densities of individual basins are 0 0.29 km−1. There is a moderate (r=0.5) correlation betwee...

formation of hydraulic jump is necessary for dissipation of the excess kinetic energy downstream of spillways and gates. hydraulic jump stilling basins of sudden expansion are one of the energy dissipater structures which are used where the available tail water depth is less than the required sequent depths. in the present study to further reduce the hydraulic jump sequent depths ratio, a rough...

The hospital environment is increasingly recognized as a reservoir for hospital-acquired pathogens. During a 44-month study period, a total of 1,103 basins from 88 hospitals in the United States and Canada were sampled. Overall, 62.2% of the basins (at least 1 basin at each hospital) were contaminated with commonly encountered hospital-acquired pathogens.

Abstract Strike-slip faults are classically associated with pull-apart basins where continental crust is thinned between two laterally offset fault segments. We propose a subsidence mechanism to explain the formation of new type basin no substantial segment or syn-strike-slip thinning observed. Such “flexural strike-slip basins” form due sediment load creating accommodation space by bending lit...