Propagation time through standard (solid core) optical fibers changes with temperature at a rate of 40 ps/km/K. The thermo-optic effect in silica glass accounts for about 95% of this change and thus hollow core fibers, in which the majority of optical power propagates through an air rather than glass core, can have this sensitivity greatly reduced. To date we have demonstrated a sensitivity as ...

The purposes of this study were to create a three-dimensional representation of strain during isometric contraction in vivo and to interpret it with respect to the muscle fiber direction. Diffusion tensor MRI was used to measure the muscle fiber direction of the tibialis anterior (TA) muscle of seven healthy volunteers. Spatial-tagging MRI was used to measure linear strains in six directions du...

We demonstrate two techniques to reduce the effects of fiber chromatic dispersion in fiber-wireless systems incorporating external modulators. We theoretically and experimentally show that the achievable link distance can be increased by varying the chirp parameter of the modulator to give large negative chirp using a dual-electrode Mach–Zehnder modulator (MZM) biased at quadrature. In addition...

We report on the observation of various bound states of dispersion-managed (DM) solitons in a passively mode-locked erbium-doped fiber ring laser at near zero net cavity group velocity dispersion (GVD). The generated DM solitons are characterized by their Gaussian-like spectral profile with no sidebands, which is distinct from those of the conventional solitons generated in fiber lasers with la...

The common and traditional method for dispersion compensation in optical domain is concatenating the transmit optical fiber by a compensating optical fiber having high-negative dispersion coefficient. In this paper, we take an opposite direction and show how an optical fiber with high-positive dispersion coefficient can also be used for dispersion compensation. Our optical dispersion compensati...

Corresponding Author: Valentin Kosev Institute of Forage Crops, 5800 Pleven, 89 Gen. Vl. Vazov Str., Bulgaria Tel: +359886021598 Email: [email protected] Abstract: In breeding process of forage pea (Pisum sativum L.) inter variety crosses between two Bulgarian: Pleven 4 (spring form) and Pleven 10 (winter form) and two Russian: Rosacrono (spring form) and Shtambovyi (winter form) varieties a...

OBJECTIVE Bacterial leakage and root fractures are the most important reasons of root canal treatment failure. Due to the lack of adhesion of gutta percha to the canal walls, Resilon has been introduced as a root-filling material able to bond to the root walls. Metal posts may predispose the tooth walls to oblique and vertical fracture which usually leads to tooth loss; whereas, fiber posts may...

Isolated single frog muscle fibers were locally activated by applying negative current pulses to a pipette whose tip was in contact with the fiber surface. In contrast to the graded inward spread of contraction initiated by a moderate depolarization, the contraction in response to a strong negative current was observed to spread transversely around the whole perimeter but not through the center...

The efficacy of adenovirus (Ad)-based gene therapy might be significantly improved if viral vectors capable of tissue-specific gene delivery could be developed. Previous attempts to genetically modify the tropism of Ad vectors have been only partially successful, largely due to the limited repertoire of ligands that can be incorporated into the Ad capsid. Early studies identified stringent size...

Cyclooxygenase-2 (COX-2) is a critically important mediator of inflammation that significantly influences tumor angiogenesis, invasion, and metastasis. We investigated the role of COX-2 expressed by triple negative breast cancer cells in altering the structure and function of the extracellular matrix (ECM). COX-2 downregulation effects on ECM structure and function were investigated using magne...