Ultrasonic Sensitivity of Strain-Insensitive Fiber Bragg Grating Sensors and Evaluation of Ultrasound-Induced Strain

In conventional ultrasound detection in structures, a fiber Bragg grating (FBG) is glued on or embedded in the structure. However, application of strain to the structure can influence the sensitivity of the FBG toward ultrasound and can prevent its effective detection. An FBG can work as a strain-insensitive ultrasound sensor when it is not directly glued to the monitored structure, but is instead applied to a small thin plate to form a mobile sensor. Another possible configuration is to affix an FBG-inscribed optical fiber without the grating section attached to the monitored structure. In the present study, sensitivity to ultrasound propagated through an aluminum plate was compared for a strain-insensitive FBG sensor and an FBG sensor installed in a conventional manner. Strains induced by ultrasound from a piezoelectric transducer and by quasi-acoustic emission of a pencil lead break were also quantitatively evaluated from the response amplitude of the FBG sensor. Experimental results showed that the reduction in the signal-to-noise ratio for ultrasound detection with strain-insensitive FBG sensors, relative to traditionally-installed FBG sensors, was only 6 dB, and the ultrasound-induced strain varied within a range of sub-micron strains

Detection of Murine Post-Pneumonectomy Lung Regeneration by 18FDG PET Imaging

Background: An intriguing biologic process in most adult mammals is post-pneumonectomy lung regeneration, that is, the removal of one lung (pneumonectomy) results in the rapid compensatory growth of the remaining lung. The spatial dependence and metabolic activity of the rodent lung during compensatory lung regeneration is largely unknown. Methods: To determine if murine lung regeneration could be detected in vivo, we studied inbred mice 3, 7, 14, and 21 days after left pneumonectomy. The remaining lung was imaged using microCT as well as the glucose tracer 2-deoxy-2-[18 F]fluoro-d-glucose (18FDG) and positron-emission tomography (PET). Because of the compliance of the murine chest wall, reproducible imaging required orotracheal intubation and pressure-controlled ventilation during scanning. Results: After left pneumonectomy, the right lung progressively enlarged over the first 3 weeks. The cardiac lobe demonstrated the greatest percentage increase in size. Dry weights of the individual lobes largely mirrored the increase in lung volume. PET/CT imaging was used to identify enhanced metabolic activity within the individual lobes. In the cardiac lobe, 18FDG uptake was significantly increased in the day 14 cardiac lobe relative to preoperative values (p < .05). In contrast, the 18FDG uptake in the other three lobes was not statistically significant at any time point. Conclusions: We conclude that the cardiac lobe is the dominant contributor to compensatory growth after murine pneumonectomy. Further, PET/CT scanning can detect both the volumetric increase and the metabolic changes associated with the regenerative growth in the murine cardiac lobe

Developmental changes in facial expression recognition in Japanese school-age children

Purpose : Facial expressions hold abundant information and play a central part in communication. In daily life, we must construct amicable interpersonal relationships by communicating through verbal and nonverbal behaviors. While school-age is a period of rapid social growth, few studies exist that study developmental changes in facial expression recognition during this age. This study investigated developmental changes in facial expression recognition by examining observers’ gaze on others’ expressions. Subjects : 87 school-age children from first to sixth grade (41 boys, 46 girls). Method : The Tobii T60 Eye-tracker(Tobii Technologies, Sweden) was used to gauge eye movement during a task of matching pre-instructed emotion words and facial expressions images (neutral, angry, happy, surprised, sad, disgusted) presented on a monitor fixed at a distance of 50 cm. Results : In the task of matching the six facial expression images and emotion words, the mid- and higher-grade children answered more accurately than the lower-grade children in matching four expressions, excluding neutral and happy. For fixation time and fixation count, the lower-grade children scored lower than other grade children, gazing on all facial expressions significantly fewer times and for shorter periods. Conclusion : It is guessed that the stage from lower grades to middle grades is a turning point in facial recognition