Household income, fetal size and birth weight: an analysis of eight populations.

BACKGROUND: The age at onset of the association between poverty and poor health is not understood. Our hypothesis was that individuals from highest household income (HI), compared to those with lowest HI, will have increased fetal size in the second and third trimester and birth. METHODS: Second and third trimester fetal ultrasound measurements and birth measurements were obtained from eight cohorts. Results were analysed in cross-sectional two-stage individual patient data (IPD) analyses and also a longitudinal one-stage IPD analysis. RESULTS: The eight cohorts included 21 714 individuals. In the two-stage (cross-sectional) IPD analysis, individuals from the highest HI category compared with those from the lowest HI category had larger head size at birth (mean difference 0.22 z score (0.07, 0.36)), in the third trimester (0.25 (0.16, 0.33)) and second trimester (0.11 (0.02, 0.19)). Weight was higher at birth in the highest HI category. In the one-stage (longitudinal) IPD analysis which included data from six cohorts (n=11 062), head size was larger (mean difference 0.13 (0.03, 0.23)) for individuals in the highest HI compared with lowest category, and this difference became greater between the second trimester and birth. Similarly, in the one-stage IPD, weight was heavier in second highest HI category compared with the lowest (mean difference 0.10 (0 .00, 0.20)) and the difference widened as pregnancy progressed. Length was not linked to HI category in the longitudinal model. CONCLUSIONS: The association between HI, an index of poverty, and fetal size is already present in the second trimester.

Proactive Guidance for Accurate UAV Landing on a Dynamic Platform: A Visual-Inertial Approach.

This work aimed to develop an autonomous system for unmanned aerial vehicles (UAVs) to land on moving platforms such as an automobile or a marine vessel, providing a promising solution for a long-endurance flight operation, a large mission coverage range, and a convenient recharging ground station. Unlike most state-of-the-art UAV landing frameworks that rely on UAV onboard computers and sensors, the proposed system fully depends on the computation unit situated on the ground vehicle/marine vessel to serve as a landing guidance system. Such a novel configuration can therefore lighten the burden of the UAV, and the computation power of the ground vehicle/marine vessel can be enhanced. In particular, we exploit a sensor fusion-based algorithm for the guidance system to perform UAV localization, whilst a control method based upon trajectory optimization is integrated. Indoor and outdoor experiments are conducted, and the results show that precise autonomous landing on a 43 cm × 43 cm platform can be performed.

A comparison between electronic portal imaging device and cone beam CT in radiotherapy verification of nasopharyngeal carcinoma.

The demand of greater accuracy in intensity-modulated radiotherapy (IMRT) has driven the development of more advanced verification systems. The purpose of this study is to investigate the differences in verification accuracy in terms of the position error detected between cone-beam computed tomography (CBCT) and electronic portal imaging device (EPID) in the IMRT of nasopharyngeal carcinoma (NPC). Two groups of NPC patients (n = 22 and n = 28) verified by CBCT (G1-CB), EPID (G1-EP), and EPID (G2-EP) only, respectively, were recruited. The positional errors between the G1-CB group and the G2-EP group were compared. In addition, the magnitudes of the position errors of EPID taken in the same session of the CBCT, but after necessary corrections (G1-EP), were analyzed. In the CBCT group, 455 CBCT images (G1-CB) and 206 EPID images (G1-EP) were collected, whereas 319 EPID images (G2-EP) for the EPID group, were recorded. The median position errors detected in CBCT were between 0.80 and 0.90 mm in the antero-posterior (A-P), left-right (L-R), and supero-inferior (S-I) directions, whereas those of the EPID were all 0.50 mm. The magnitude of position deviation detected by the CBCT was higher than that of the EPID and their differences were extremely significant (p < 0.001). The frequencies in the G2-EP group with position errors greater than the tolerance (2 mm) were 32, 42, and 27 in the A-P, L-R, and S-I directions, respectively, which accounted for 16.5%, 21.6%, and 13.9% of the total number of EPID. There was difference in verification capability between the CBCT and EPID when applied to IMRT of NPC patients. Because an average of 1 of 6 verifications in EPID was inferior to that of the CBCT, verification by CBCT is recommended.