Ultrasonic Transmitter Implemented on Arduino with Direct Digital Synthesis

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NVUltrasonic frequency signals can be employed in a manner similar to radio frequency signals for target detection and ranging by utilizing concepts from radar systems. This project uses components operating in the ultrasonic frequency spectrum to transmit and receive signals for detection and ranging. The project concept contains a single channel ultrasonic transmitter and a single channel ultrasonic receiver. An Arduino Due microcontroller is used to coordinate the radar system. The radar transmitter is continuously transmitting chirp waveforms in a frequency sweep pattern from 30 kHz to 50 kHz. Chirp echoes are received by the ultrasonic microphone. The echoes are mixed with the originally transmitted chirp, which creates a beat frequency response. The beat frequency is used to calculate the range of the target.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

Arsenic exposure, telomere length, and expression of telomere-related genes among Bangladeshi individuals

BACKGROUND: Inorganic arsenic is a carcinogen whose mode of action may involve telomere dysfunction. Recent epidemiological studies suggest that chronic arsenic exposure is associated with longer telomeres and altered expression of telomere-related genes in peripheral blood. In this study, we evaluated the association of urinary arsenic concentration with expression of telomere-related genes and telomere length in Bangladeshi individuals with a wide range of arsenic exposure through naturally contaminated drinking water. METHODS: We used linear regression models to estimate associations between urinary arsenic and array-based expression measures for 69 telomere related genes using mononuclear cell RNA samples from 1,799 individuals. Association between arsenic exposure and a qPCR-based telomere length was assessed among 167 individuals. RESULTS: Urinary arsenic was possitively associated with expression of WRN, and negatively associated with TERF2, DKC1, TERF2IP and OBFC1 (all P < 0.00035, Bonferroni correction threshold). We detected interaction between urinary arsenic and arsenic metabolism efficiency in relation to expression of WRN (P for interaction = 0.00008). In addition, we observed that very high arsenic exposure was associated with longer telomeres compared to very low exposure (P=0.02). DISCUSSION: Our findings suggest that arsenic’s carcinogenic mode of action may involve alteration of telomere maintenance and/or telomere damage. This study extends our knowledge regarding the effect of arsenic on telomere length and expression of telomere-related genes