The short form of TSLP is constitutively translated in human keratinocytes and has characteristics of an antimicrobial peptide.

Thymic stromal lymphopoietin (TSLP) has multifaceted immunological functions ranging from maintenance of tolerance to induction of disease. Two human transcript variants of TSLP are described: a long form (variant 1; lfTSLP) consisting of four exons and an alternative, short form (variant 2; sfTSLP) that lacks two exons compared with variant 1. SfTSLP has not been described at the protein level or functionally studied. Here, we demonstrate that the human sfTSLP is the predominant form of TSLP, constitutively expressed at the mRNA and protein level in keratinocytes of oral mucosa and skin and in salivary glands, is released in saliva, and is not regulated in the same manner as the long form. Compared with lfTSLP, sfTSLP exhibits a markedly stronger antibacterial activity. Synthetic sfTSLP did not activate signal transducer and activator of transcription 5 (STAT5) signaling in CD1c(+) dendritic cells nor interfered with STAT5 activation by lfTSLP. SfTSLP may, therefore, act as an antimicrobial peptide in the oral cavity and on the skin to create a defense barrier that aids in the control of both commensal and pathogenic microbes. The results show that the two translational products of the TSLP gene have a different expression and different biological properties, and emphasize the importance of analyzing the two TSLP isoforms separately.

Application of fiber-optic bragg grating sensors in monitoring environmental loads of overhead power transmission lines.

We demonstrate the capability of using fiber-optic sensors for measurements on environmental loads on a high-power, overhead transmission line. A trial system with three Bragg gratings, including a temperature reference, was installed on a 160-m span of a 60-kV line. An interrogation system with a tunable distributed Bragg reflector laser source was used. Several measurements of the induced loads on a conductor were recorded in various wind conditions. In particular, aeolian vibrations were frequently observed, and several measurements of this phenomenon were made. The results correlate well with simple theoretical predictions and visual observations.

Pulse distortion in optical fibers with transverse offset splices.

A method for calculating the pulse distortion in a spliced multimode optical fiber vs transverse misalignment is presented. Measurements on two graded-index and one step-index fibers are shown. In graded-index fibers both theory and experiment show a rapid decrease of the rms pulse width for large offsets. For smaller offsets some discrepancies are observed. These are remedied to some extent by considering unequal mode excitation conditions. Different lengths of the two spliced sections are investigated as well. In the step-index case the experiments show no variation in the rms pulse width as predicted by the theory.

Application of Bragg grating sensors in the characterization of scaled marine vehicle models.

Experiments using two different fiber-optic Bragg grating strain sensor systems to measure dynamic loads, slamming forces, and bending moments on a scaled catamaran model are reported. The system designed to measure slamming forces is based on dynamic locking of the laser diode wavelength to the peak wavelength of a Bragg grating mounted in a force cell. The sensor system has a dynamic range of 27 dB (1-550 N) and a bandwidth in excess of 1 kHz. For the measurement of bending moments, a time-domain multiplexing system, which used a unique pulsed rf modulation technique, of two Bragg grating sensors mounted on a steel beam was designed. The dynamic range of this system was also 27 dB [17 Nm (Newton meter) with a 0.03-Nm resolution]. The bandwidth was limited to approximately 50 Hz.