Crater retention ages of the 20 largest impact basins previously recognized on Mars suggest most formed in a relatively short time, perhaps in less than 200 million years. New crustal thickness data suggests there are several additional very large basins, some lying outside the areas affected by those already known. Crater retention ages for these newly identified basins are not significantly o...

High-resolution gravity data from the Gravity Recovery and Interior Laboratory (GRAIL) mission provide the opportunity to analyze the detailed gravity and crustal structure of impact features in the morphological transition from complex craters to peak-ring basins on the Moon. We calculate average radial profiles of free-air anomalies and Bouguer anomalies for peak-ring basins, protobasins, and...

Cement grouting is an operation often carried out to consolidate and seal the rock mass in dam sites and tunnels. The quality and efficiency of a grouting operation depends on various factors such as water take, grout properties and grouting pressure. One of the parameters which have the highest effect is pressure since the application of excessive pressure causes the hydraulic fracture phenome...

In this paper, we analyse the distributional patterns of adult helminth parasites of freshwater fishes with respect to the main hydrological basins of Mexico. We use the taxonomic distinctness and the variation in taxonomic distinctness to explore patterns of parasite diversity and how these patterns change between zoogeographical regions. We address questions about the factors that determine t...

A taxonomic review of Copella is presented based on the analysis of the type material of all nominal species and extensive material from South American drainages. Six out of ten nominal species are recognized as valid: Copella arnoldi, C. callolepis, C. compta, C. eigenmanni, C. nattereri, and C. vilmae. Copella carsevennensis is a junior synonym of C. arnoldi, C. nigrofasciata and 'Nannostomus...

The Rokel River (RR) basin is one of the most neglected ichthyofaunal basins, despite potential for undetected diversity and high levels endemism. Data on molecular phylogeny freshwater fish from this river are rare. Morphological features alone inadequate precise species identification. Here, a phylogenetic analysis performed based mtDNA Cytb gene eleven cyprinid RR recovered distinct lineages...

[1] This paper employs a circularity function to quantify the internal morphology of Martian watershed basins in Margaritifer Sinus region and to infer the primary erosional processes that led to their current geomorphologic characteristics and possible climatic conditions under which these processes operated. The circularity function describes the elongation of a watershed basin at different e...