Vulnerable newborn types: Analysis of population-based registries for 165 million births in 23 countries, 2000-2021.

OBJECTIVE: To examine the prevalence of novel newborn types among 165 million live births in 23 countries from 2000 to 2021. DESIGN: Population-based, multi-country analysis. SETTING: National data systems in 23 middle- and high-income countries. POPULATION: Liveborn infants. METHODS: Country teams with high-quality data were invited to be part of the Vulnerable Newborn Measurement Collaboration. We classified live births by six newborn types based on gestational age information (preterm 90th centile) for gestational age, according to INTERGROWTH-21st standards. We considered small newborn types of any combination of preterm or SGA, and term + LGA was considered large. Time trends were analysed using 3-year moving averages for small and large types. MAIN OUTCOME MEASURES: Prevalence of six newborn types. RESULTS: We analysed 165 017 419 live births and the median prevalence of small types was 11.7% - highest in Malaysia (26%) and Qatar (15.7%). Overall, 18.1% of newborns were large (term + LGA) and was highest in Estonia 28.8% and Denmark 25.9%. Time trends of small and large infants were relatively stable in most countries. CONCLUSIONS: The distribution of newborn types varies across the 23 middle- and high-income countries. Small newborn types were highest in west Asian countries and large types were highest in Europe. To better understand the global patterns of these novel newborn types, more information is needed, especially from low- and middle-income countries

Capacitance of the Abrupt Transition from Coaxial-to-Circular Waveguide

A least-squares boundary residual method is applied to calculate the discontinuity capacitance of an abrupt transition from coaxial-to-circular waveguide. Accurate values of the capacitance are presented here and compared with published results. Our results are believed to be accurate to about ± 0.1 fF and hence suitable for standards work

Analysis of rectangular waveguide partially loaded with lossy dielectrics

An analysis is presented for rectangular waveguides with partial dielectric loading in the H-plane. Accurate results are given for attenuation and phase constant for lossy dielectric, using both exact and perturbation approaches. Particular attention is paid to the abnormal situation where attenuation can be greater for partial loading than for complete loading by the same lossy material. This abnormality was reported by Bui and Gagne but discounted by them as being mathematically spurious. By contrast, in this paper an exact theory has been used and the abnormality is shown to be genuine, and due to the hybrid mode redistribution of fields

Scattering coefficients of a dielectric taper in a rectangular waveguide

An exact approach is presented for calculating the scattering coefficients of a dielectric taper in a rectangular waveguide. The approach is based on the combination of the least-squares-boundary residual method (l.s.b.r.m.) and the Weissfloch-Feenberg method of measurement for a low-loss waveguide junction. An algorithm, based on the approach, has been developed which computes the scattering matrix of a dielectric taper. Typical results are presented for the taper with electric field parallel to the dielectric/air interface

Automated spatial and temporal image analysis of bacterial cell growth

The state-of-the-art technology using ow-chamber microscopy imaging enables us to gain insight into the arcana of bacterial cell growth. However, a large number of high resolution develop- mental image data sets are produced that need to be properly processed and analyzed. The mathematical challenge lies in the automated image analysis, extraction of cell size profiles and determination of the time to cell division. Detailed noise analysis was carried out to correctly ?filter out the noise without losing important image information. A novel occluding convex image segmentation is developed which outperforms the existing algorithms in the literature. Next cell size parameters are identified via inertia equivalent ellipse ?fitting. Finally, individual cell division times are computed using k-means clustering. The information about individual cell division time distributions is of great value, as it has not been available before on such a large scale. Therefore this type of automation plays a key role in the new era of cell growth modelling

Modelling PSF of Scanning Electron Microscopes for Image Restoration

Publication in the conference proceedings of EUSIPCO, Rhodes, Greece, 199