Phlebotomine sand flies are vectors of Leishmania that are acquired by the female sand fly during blood feeding on an infected mammal. Leishmania parasites develop exclusively in the gut lumen during their residence in the insect before transmission to a suitable host during the next blood feed. Female phlebotomine sand flies are blood feeding insects but their life style of visiting plants as ...

The vertical migration of M. incognita juveniles introduced at 20 cm from the roots was studied in five natural soils, 100% silica sand, 95% silica sand with 5% clay, 90% silica sand with 10% clay, and 95% silica sand with 5% clay as a concentrated layer. In natural soils the percentage of juveniles capable of migrating 20 cm and penetrating the roots decreased when the percentage of clay and s...

Sand banks have a wavelength between 1 and 10 km, and they are up to several tens of meters high. Also, sand banks may have an impact on large-scale human activities that take place in the North Sea like sand mining, shipping, offshore wind farms, etc. Therefore, it is important to know where sand banks occur and what their natural behavior is. Here, we use an idealized model to predict the occ...

Tillage practices significantly influences soil physical characteristics and crop productivity. The infiltration characteristics, bulk density, porosity, penetration resistance, grain yield of rice and wheat were measured under no-till without residue (NT), roto-tillage (RT), and no-till with residue i.e. happy seeder (HS) in rice-wheat cropping system in sandy loam (SL) and loamy sand (LS) soi...

The Sand Pile Model (SPM) and its generalization, the Ice Pile Model (IPM), originate from physics and have various applications in the description of the evolution of granular systems. In this article, we deal with the enumeration and the exhaustive generation of the accessible configuration of the system. Our work is based on a new recursive decomposition theorem for SPM configurations using ...

Planktotrophic invertebrate larvae have two dissociable stages during development, a facultative feeding period, whose length is determined by the amount of maternal provisioning in the egg, and an obligate feeding period, whose length is determined by the quantity of exogenous energy needed to reach metamorphic competence. Here we set out to experimentally test the impact of feeding during the...

We calculated the frequency distributions of cluster sizes in the sand pile models. Two cellular automata models differing in the rules of adding sand particles are used. For the model with local perturbation only, the distribution shows a power law behavior regardless of the spatial dimension that the sand pile is situated at. For the other model where the perturbation generated by the additio...

Following fertilization of the egg of the sand dollar Echinarachnius parma, tritiated thymidine (H(3)TDR) was taken up independently by the male and female pronuclei beginning within about 15 to 20 minutes, and the labeled pronuclei fused at about 30 to 40 minutes. At cleavage 90 minutes later the labeled nuclear material was distributed to both daughter cells. Unfertilized eggs and sperm expos...

Avalanches of various sizes occur due to instability during sand dune dynamics. A physically viable equation to model sand dune dynamics is a first order nonlinear difference equation. To visualize the size distribution of avalanches, sand dune dynamics has been numerically simulated by changing the strength of nonlinearity parameter (λ) that shows different impacts on dune dynamics. An equatio...