Morphologies of highly complex star dunes are the result aeolian dynamics in past and present times. These reflect climatic conditions associated forces like sediment availability vegetation cover, as well feedbacks with adjacent environments. However, an understanding on dune morphometries is still lacking sufficient detail, their influence formation evolution remains unclear. We therefore inv...

Neural crest-like cells (NCLC) that express the HNK-1 antigen and form body pigment cells were previously identified in diverse ascidian species. Here we investigate the embryonic origin, migratory activity, and neural crest related gene expression patterns of NCLC in the ascidian Ciona intestinalis. HNK-1 expression first appeared at about the time of larval hatching in dorsal cells of the pos...

The soil resources of Sierra Leone remain an integral part sustainable agricultural development but knowledge the suitability soils and their management requirements for a variety land uses is still lacking to greater extent. In this view, detailed survey three chiefdoms in Northern was undertaken evaluate genesis interpret soil-landscape properties relationships using toposequence free style a...

The best means to utilize X-ray computed tomography (CT) and ultrasound to predict carcass lean, fat and bone weights in vivo in terminal sire sheep were tested. Data on 160 lambs from three breeds were considered: 50 Suffolk males, 50 Suffolk females, 40 Texel males and 20 Charollais males. One-fifth of the lambs within each breed and sex group were slaughtered at each of 14, 18 and 22 weeks o...

Direct development is a common reproductive mode in living amphibians characterized by absence of the free-living, aquatic larval stage. In Eleutherodactylus, a species-rich genus of New World frogs, evolution of direct development from the ancestral biphasic ontogeny is correlated with a comprehensive modification in embryonic cranial patterning, including the loss of many larval-specific comp...

Avian neural crest cells migrate on precise pathways to their target areas where they form a wide variety of cellular derivatives, including neurons, glia, pigment cells and skeletal components. In one portion of their pathway, trunk neural crest cells navigate in the somitic mesoderm in a segmental fashion, invading the rostral, while avoiding the caudal, half-sclerotome. This pattern of cell ...

The developing chick hindbrain is transiently divided into a series of repeating units or rhombomeres. Recent work has shown that an alternating periodicity exists both in the cell surface properties of rhombomeres and in the segmental origin of hindbrain neural crest cells. Experiments in which rhombomeres from different axial levels were confronted in the absence of an interrhombomere boundar...

Trunk neural crest cells and motor axons move in a segmental fashion through the rostral (anterior) half of each somitic sclerotome, avoiding the caudal (posterior) half. This metameric migration pattern is thought to be caused by molecular differences between the rostral and caudal portions of the somite. Here, we describe the distribution of T-cadherin (truncated-cadherin) during trunk neural...

Digital in-line holography (DIH) measurements are performed in a wave flume tank to study the three dimensional distribution of spherical Polyvincyl Chloride (PVC) particles over fixed rippled beds under regular water waves. Homogeneous and heterogeneous sizes considered. The positions PVC reconstructed from holograms assess their volume concentration during decay surface Particles estimated cl...