In this research, a method for producing gum tragacanth (GT) fibers is presented. Ribbon type GT of Astragalus Gummifer species were obtained from local production lands. The gum was treated with alkali to increase its process ability, and allowed to stand for a period of time to reach the proper viscosity and/or to "ripen". Samples with different ripening times were prepared and their viscosit...

the electronic and structural properties of pristine and carbon doped (c-doped) boron nitride nano-ribbons(bnnrs) have been studied employing density functional theory (dft) calculations. total energies, gapenergies, dipole moments, and quadrupole coupling constants (qcc) have been calculated in the optimizedstructures of the investigated bnnrs. the results indicated that the stability and gap ...

Ribbon tiles are polyominoes consisting of n squares laid out in a path, each step of which goes north or east. Tile invariants were rst introduced in P1], where a full basis of invariants of ribbon tiles was conjectured. Here we present a complete proof of the conjecture, which works by associating ribbon tiles with certain polygons in the complex plane, and deriving invariants from the signed...

Recent works in algebraic combinatorics have brought up to date the importance of certain planar structures, called ribbon tableaux, which are generalizations of Young tableaux. This paper gives an algorithm to eeciently distribute, using PVM, the computation of the set of all ribbon tableaux of given shape and weight. It also provides a way to compute the spin polynomials associated to those s...

Information flow through neural circuits is determined by the nature of the synapses linking the subtypes of neurons. How neurons acquire features distinct to each synapse remains unknown. We show that the transcription factor Mafb drives the formation of auditory ribbon synapses, which are specialized for rapid transmission from hair cells to spiral ganglion neurons (SGNs). Mafb acts in SGNs t...

Ribbon synapses mediate continuous release in neurons that have graded voltage responses. While mammalian retinas can signal visual flicker at 80-100 Hz, the time constant, τ, for the refilling of a depleted vesicle release pool at cone photoreceptor ribbons is 0.7-1.1 s. Due to this prolonged depression, the mechanism for encoding high temporal frequencies is unclear. To determine the mechanis...

INTRODUCTION Four species of seals live in association with sea ice in Alaska; these are the ringed seal (Phoca hispida), spotted seal (P. largha), bearded seal (Erignathus barbatus), and ribbon seal (Histriophoca fasciata or Phoca fasciata). Ribbon seals, the focus of this paper, range from the Sea of Japan and the Sea of Okhotsk eastward into the Bering Sea and northward into the Chukchi Sea....