Solutions to Monge-Kantorovich equations, expressing optimality condition in mass transportation problem with cost equal to distance, are stationary points of a critical-slope model for sand surface evolution. Using a dual variational formulation of sand model, we compute both the optimal transport density and Kantorovich potential as t → ∞ limit of evolving sand flux and sand surface, respecti...

Most of the Tylenchulus semipenetrans larvae applied on the surface of four soils in pots 14.5-cm deep moved no further downward than 6.5 crn, and remained in the upper half of the pot. The percentage of second-stage larvae that developed into adult females on 'Homosassa' sweet orange in the soils were: sandy loam, 6.8% in the same soil with inoculation holes, 8.6%; loamy sand, 5.4%; coarse san...

BACKGROUND Leishmaniasis remains a global health problem because of the substantial holes that remain in our understanding of sand fly ecology and the failure of traditional vector control methods. The specific larval food source is unknown for all but a few sand fly species, and this is particularly true for the vectors of Leishmania parasites. We provide methods and materials that could be us...

Tadpoles of the monotypic Indian dancing frog family Micrixalidae have remained obscure for over 125 years. Here we report the discovery of the elusive tadpoles of Micrixalus herrei from the sand beds of a forested stream in southern Western Ghats, and confirm their identity through DNA barcoding. These actively burrowing tadpoles lead an entirely fossorial life from eggs to late metamorphic st...

Sand fields develop different patterns, such as sandbars, sand ridges, sand ripples, sand dunes, and river dunes. These vary in shape from crescent to ridge-like patterns. They are formed in areas such as deserts, lakes and seashores, where winds or fluid flows are strong and tend to blow from one direction or oscillate. There is a great deal of order in these patterns: perhaps a simple model c...

The western sand darter Ammocrypta clara, and eastern sand darter Ammocrypta pellucida, are sand-dwelling fishes of conservation concern. Past research has emphasized the importance of studying individual populations of conservation concern, while recent research has revealed the importance of incorporating landscape scale processes that structure habitat mosaics and local populations. We exami...

Ecological niche models are useful tools to infer potential spatial and temporal distributions in vector species and to measure epidemiological risk for infectious diseases such as the Leishmaniases. The ecological niche of 28 North and Central American sand fly species, including those with epidemiological relevance, can be used to analyze the vector's ecology and its association with transmis...