During amphibian development, non-canonical Wnt signals regulate the polarity of intercalating dorsal mesoderm cells during convergent extension. Cells of the overlying posterior neural ectoderm engage in similar morphogenetic cell movements. Important differences have been discerned in the cell behaviors associated with neural and mesodermal cell intercalation, raising the possibility that dif...

background and objective: mediastinal masses in children are a heterogenous group of asymptomatic potentially life-threatening congenital, infectious, or neoplastic lesions that present complex diagnostic and therapeutic dilemmas. materials and methods: the clinical and laboratory features of 65 patients who had open biopsies in ali-asghar hospital over 11 years were reviewed. results: seventy-...

osteosarcoma (osteogenic sarcoma: os) is the most common primary malignant bone tumor of long bones, whereas primary osteosarcoma of chest wall, especially in sternum, is extremely rare. we report a 57-year-old man with an immobile slow growing mass located in the middle of the sternum. the patient had no significant pain or tenderness and the past medical history was not remarkable. ct-scan sh...

in this paper we investigate a nonlinear evolution model described by the rosenau-kdv equation. we propose a three-level average implicit finite difference scheme for its numerical solutions and prove that this scheme is stable and convergent in the order of o(τ2 + h2). furthermore we show the existence and uniqueness of numerical solutions. comparing the numerical results with other methods in...

Epithelial cells and other groups of cells acquire a polarity orthogonal to their apical-basal axes, referred to as Planar Cell Polarity (PCP). The process by which these cells become polarized requires a signaling pathway using Frizzled as a receptor. Responding cells sense cues from their environment that provide directional information, and they translate this information into cellular asymm...

In vertebrates, paraxial mesoderm is partitioned into repeating units called somites. It is thought that the mechanical forces arising from compaction of the presumptive internal cells of prospective somites cause them to detach from the unsegmented presomitic mesoderm [1-3]. To determine how prospective somites physically segregate from each other, we used time-lapse microscopy to analyze the ...

We have applied the Ewald-Kornfeld formulation to a tetragonal lattice of point dipoles, in an attempt to examine the effects of geometric anisotropy on the local field distribution. The various problems encountered in the computation of the conditionally convergent summation of the near field are addressed and the methods of overcoming them are discussed. The results show that the geometric an...

background some sonographic positions for detection of abdominal wall hernias needed .in this paper we described the sonographic technique of abdominal wall hernia. methods from june 2013 to july 2016, three hundred seventy four patients referred in our department for evaluation of abdominal wall hernia (median age, 38 years; range 2 - 86 years). one hundred and ninety patients had abdominal he...

Parahupehsuchus longus is a new species of marine reptile from the Lower Triassic of Yuan'an County, Hubei Province, China. It is unique among vertebrates for having a body wall that is completely surrounded by a bony tube, about 50 cm long and 6.5 cm deep, comprising overlapping ribs and gastralia. This tube and bony ossicles on the back are best interpreted as anti-predatory features, suggest...