Assemblies of granular particles mechanically stable under their own weight contain arches. These are structural units identified as sets of mutually stable grains. It is generally assumed that these arches shield the weight above them and should bear most of the stress in the system. We test such hypothesis by studying the stress born by in-arch and out-of-arch grains. We show that, indeed, pa...

Tbx2 is a member of the T-box family of transcription factors essential for embryo- and organogenesis. A deficiency in the zebrafish paralogue tbx2a causes abnormalities of the pharyngeal arches in a p53-independent manner. The pharyngeal arches are formed by derivatives of all three embryonic germ layers: endodermal pouches, mesenchymal condensations and neural crest cells. While tbx2a express...

Xenopus laevis type XVIII collagen occurs in three variants, 22 + 1285 amino acid residues (signal peptide + mature protein), 23 + 1581 residues and 23 + 1886 residues in length, differing in their N-terminal non-collagenous domains. The region showing highest homology to mammalian counterparts is the C-terminal endostatin domain. All three variants are expressed, at different levels, during ea...

Frontobasal injuries and some other diseases of frontal sinuses sometimes require radical surgery with the obliteration of the sinus. A cosmetic correction of the forehead and supraorbital arches has to be performed after such a procedure. Nowadays, there is a wide choice of alloplastic materials on the market. We tried polymethyl methacrylate implants in correction of the exterior appearance o...

bridges are planned for construction on the U.S. 59 in Houston, Texas. Each bridge will be of the tied-arch type and will be constructed on-grade over cut areas with clear spans of 228 f t (69.5m). To expedite construction, unique procedures are planned which use existing bridges as platforms for final fabrication of the tied arches. This procedure requires consideration of wind loadings on the...

The Weihe Basin is one of the regions with highest concentrations ground fissure development and most serious disasters in China. Hidden fissures are formed shallow soil layer due to preexisting generated by tectonism, hidden suddenly exposed surface after heavy rainfall. Because details water erosion process cannot be replicated geological survey methods, extension mechanism has not fully deve...

Expression of Fgf-8, Bmp-4, Bmp-7, and shh in the branchial arches of the chick embryo is examined by in situ hybridization. Fgf-8 expression is initially broad and diffuse, becoming more tightly restricted, particularly in the epithelium of the posterior ectodermal margin (PEM) of the 2nd branchial arch. Bmp-7 transcripts, first seen at stage 12 in discrete regions corresponding to the develop...