Background Variations in childbirth interventions may indicate inappropriate use. Most variation studies are limited by the lack of adjustments for maternal characteristics and do not investigate variations in adverse outcomes. This study aims to explore regional variations in the Netherlands and their correlations with referral rates, birthplace, interventions, and adverse outcomes, adjusted for maternal characteristics. Methods In this nationwide retrospective cohort study, using a national data register, intervention rates were analysed between twelve regions among single childbirths after 37 weeks’ gestation in 2010–2013 (n = 614,730). These were adjusted for maternal characteristics using multivariable logistic regression. Primary outcomes were intrapartum referral, birthplace, and interventions used in midwife- and obstetrician-led care. Correlations both between primary outcomes and between adverse outcomes were calculated with Spearman’s rank correlations. Findings Intrapartum referral rates varied between 55–68% (nulliparous) and 20–32% (multiparous women), with a negative correlation with receiving midwife-led care at the onset of labour in two-thirds of the regions. Regions with higher referral rates had higher rates of severe postpartum haemorrhages. Rates of home birth varied between 6–16% (nulliparous) and 16–31% (multiparous), and was negatively correlated with episiotomy and postpartum oxytocin rates. Among midwife-led births, episiotomy rates varied between 14–42% (nulliparous) and 3–13% (multiparous) and in obstetrician-led births from 46–67% and 14–28% respectively. Rates of postpartum oxytocin varied between 59–88% (nulliparous) and 50–85% (multiparous) and artificial rupture of membranes between 43–52% and 54–61% respectively. A north-south gradient was visible with regard to birthplace, episiotomy, and oxytocin. Conclusions Our study suggests that attitudes towards interventions vary, independent of maternal characteristics. Care providers and policy makers need to be aware of reducing unwarranted variation in birthplace, episiotomy and the postpartum use of oxytocin. Further research is needed to identify explanations and explore ways to reduce unwarranted intervention rates.
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In one-dimensional disordered wires electronic states are localized at any energy. Correlations of the states at close positive energies and the AC conductivity \sigma(\omega) in the limit of small frequency are described by the Mott-Berezinskii theory. We revisit the instanton approach to the statistics of wave functions and AC transport valid in the tails of the spectrum (large negative energies). Applying our recent results on functional determinants, we calculate exactly the integral over Gaussian fluctuations around the exact two-instanton saddle point. We derive correlators of wave functions at different energies beyond the leading order in the energy difference. This allows us to calculate corrections to the Mott-Berezinskii law (the leading small-frequency asymptotic behavior of \sigma(\omega)) which approximate the exact result in a broad range of \omega. We compare our results with the ones obtained for positive energies.
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Dit project richt zich op de ontwikkeling van de biotechnologische en chemische procesvoering om op basis van mycelium een alternatief voor leer te produceren. In vergelijking met leer is het voordeel van mycelium dat geen runderen nodig zijn, de productie kan plaatsvinden onder industriële condities en met gebruik van reststromen, de CO2 uitstoot alsook hoeveelheid afval verlaagd wordt, en het gebruik van toxische stoffen zoals chroom wordt vervangen door biobased alternatieven. In het project zullen de procescondities worden bepaald die leiden tot de vorming van optimaal mycelium. Daartoe zullen twee verschillende schimmels worden gekweekt in bioreactoren bij de Hogeschool Arnhem Nijmegen (HAN), waarbij specifiek de effecten van de procescondities (temperatuur, pH, shear, beluchting) en de samenstelling van het kweekmedium op groei van het mycelium en materiaal eigenschappen zullen worden onderzocht. De meest optimale condities zullen vervolgens worden opgeschaald. Op het op deze wijze verkregen materiaal zal Mylium BV een aantal nabehandelingsstappen uitvoeren om de sterkte, elasticiteit, en duurzaamheid van het product te vergroten. Daartoe worden biobased plasticizers, cross-linkers en/of flexibility agents gebruikt. Het resulterende eindproduct zal middels specifiek fysieke testen vergeleken worden met leer alsook worden voorgelegd aan mogelijke klanten. Indien beide resultaten positief zijn kan het betreffende proces na het project verder worden opgeschaald voor toepassing naar de markt.
Resistance to damage, fracture and failure is critical for high performance polymers, especially so in safety applications where they protect equipment or human life. In this project we investigate the use of molecular mechanochemistry tools for the measurement and analysis of mechanical impact in high performance polymers and their composites. While typically performed in a laboratory setting, these measurements hold promise for studying damage in large scale realistic samples. For this we will to develop fluorescent imaging techniques and chemistry, necessary to produce mechanoresponsive samples. This proposal will also draw correlations between imaging and mechanical testing, which can ultimately allow us to study realistic samples and recover the history of the impact they have sustained during operation.
