The bending of a flagellum, such as the flagellum which forms the tail of a seaurchin spermatozoon, is the result of active mechanochemical processes occurring within the flagellum itself, which cause it to bend actively throughout its length (Gray, 1955; Machin, 1958). To understand how flagella operate, we must understand not only the mechanisms which generate bending, but also the control me...

The Fis protein of Escherichia coli and Salmonella typhimurium stimulates several site-specific DNA recombination reactions, as well as transcription of a number of genes. Fis binds to a 15-bp core recognition sequence and induces DNA bending. Mutations in Fis which alter its ability to bend DNA have been shown to reduce the stimulatory activity of Fis in both site-specific recombination and tr...

We have used circular permutation assays to determine the extent and location of the DNA bend induced by the DNA binding domain of human wild type p53 (p53DBD) upon binding to several naturally occurring DNA response elements. We have found that p53DBD binding induces axial bending in all of the response elements investigated. In particular, response elements having a d(CATG) sequence at the ju...

We have used a circular permutation gel shift assay to show that the 5S gene transcription factor, TFIIIA, induces a bend at the internal promoter of the Xenopus oocyte-type 5S gene. The degree of bending is comparable to what we have previously observed for TFIIIA induced bending of the Xenopus somatic-type gene [Schroth, G.P. et al. (1989) Nature 340, 487-488]. In addition, we show that TFIII...

Abstract The fracturing process in geomaterials is studied to characterize a potential host rock for radioactive waste, such as the kaolinite-rich Opalinus Clay formation. Because of its sedimentary genesis, this can be considered transversely isotropic geomaterial. A semi-circular bending test here modeled based on eXtended Finite Element Method (XFEM), check formation and propagation cracks r...

We investigate energetics and structure of circular and polygonal single wall carbon nanotubes (SWNTs) using large scale molecular simulations on NAS SP2, motivated by their unusual electronic and magnetic properties. The circular tori are formed by bending tube (n, n) whereas the polygonal tori are constructed by turning the joint of two tubes of (n, n), (n+1, n-1) and (n+2, n-2) with topologi...

Using a novel in-situ scanning tunneling microscope integrated into a 200kV transmission electron microscope (TEM), we have shown that boron nitride nanotubes (BNNTs) possess remarkable flexibility and convert from insulator to semi-conductor upon bending. To measure the electrical properties, the BNNT was bent between two gold contacts constructing a metal-semiconductor-metal circuit. The resi...

in fact the most suitable method for finding the load bearing capacity of a member under the axial load or axial load and bending is make use of the interaction diagrams. to analysis and design the hollow circular, square and rectangular high strength concrete (hsc) column shapes, a linear strain variation was assumed in the cross-section height of the members and then the static equilibrium eq...