Design and Build of a Warped Tram Station Roof in Delft

In 1992 Walter Lockefeer and Mick Eekhout designed an office for the GlassAssociation in Gouda with a flamboyant glass envelope, which ended as runner-up inan architectural competition. The design was classical in architectural sense andfuturistic in technical sense: it contained a pre-stressed glass membrane. In 2002Octatube introduced the use of twisted tempered glass panels in the realization of theCity Hall of Alphen aan den Rijn NL. Since then further research of the structuralbehaviour of twisted glass panels has been carried out by Dries Staaks, leading to aprofound knowledge about its quantitative behaviour as well as quantitative approachon stresses and stability. The latter is referred to as the “Law of Staaks”. On the basisof the developed theory the application of twisted panels has been extended andproven to be a valuable contribution in order to realise free form twisted glassenvelopes. Although the theory was investigated and set up after the first applicationin Alphen, it was only after establishment of this very theory that several buildingscould be provided with accurately engineered twisted roofs and flat roofs with twistedparts, where the glass panels were even insulated / laminated glass panels. The 1992design, which was not chosen out of disbelief concerning the innovative state of itsglass façade, could be entirely built today from the trustworthy glass technology. Theintegral innovation approach as a bridge between fundamental research, technicaldevelopment and application design, each with its own habits and peculiarities, but inmutual understanding and support, shows that integral incremental developments onmany levels pay off and produce new technologies for use in architecture. Thiscontribution ends with the application of a glass roof for a warped glass roof surface,making use of the maximum cold warping possibilities of laminated glass panels

Why increased extreme precipitation under climate change negatively affects water security

An increase in extreme precipitation is projected for many areas worldwide in the coming decades. To assess the impact of increased precipitation intensity on water security, we applied a regional-scale hydrological and soil erosion model, forced with regional climate model projections. We specifically considered the impact of climate change on the distribution of water between soil (green water) and surface water (blue water) compartments. We show that an increase in precipitation intensity leads to a redistribution of water within the catchment, where water storage in soil decreases and reservoir inflow increases. This affects plant water stress and the potential of rainfed versus irrigated agriculture, and increases dependency on reservoir storage, which is potentially threatened by increased soil erosion. This study demonstrates the crucial importance of accounting for the fact that increased precipitation intensity leads to water redistribution between green and blue water, increased soil erosion, and reduced water security. Ultimately, this has implications for design of climate change adaptation measures, which should aim to increase the water holding capacity of the soil (green water) and to maintain the storage capacity of reservoirs (blue water), benefiting rainfed and irrigated agriculture.</p

Analysing outcome variables with floor effects due to censoring: a simulation study with longitudinal trial data

ackground: Randomised controlled trials (RCTs) are the gold standard to estimate treatment effects. When patients receive effective treatment over time they may reach the limit of a certain measurement scale. This phenomenon is known as censoring and lead to skewed distributions of the outcome variable with an excess of either low (floor effect) or high values (ceiling effect). Applying traditional methods such as linear mixed models to analyse this kind of longitudinal RCT data may result in bias of the regression parameters. To deal with floor effects due to censoring,&nbsp; a tobit mixed model can be used. The objective of this study was to compare the results of longitudinal linear mixed model analyses with longitudinal tobit mixed model analyses.Methods: First, a simulation study was performed in which several situations of RCTs with floor effects were simulated. Second, data from an empirical RCT was analysed with both methods.Results: Although all analyses underestimated the intervention effects, the tobit mixed model performed much better than the linear mixed model in handling floor effects. However, with an increasing number of follow-up measurements in combination with a strong floor effect estimates from the tobit mixed model were also not accurate.Conclusion: tobit mixed model analysis should be used to estimate treatments effects in longitudinal RCTs with floor effects due to censoring.&nbsp

Longitudinal analyses of the DNA methylome in deployed military servicemen identify susceptibility loci for post-traumatic stress disorder

In order to determine the impact of the epigenetic response to traumatic stress on post-traumatic stress disorder (PTSD), this study examined longitudinal changes of genome-wide blood DNA methylation profiles in relation to the development of PTSD symptoms in two prospective military cohorts (one discovery and one replication data set). In the first cohort consisting of male Dutch military servicemen (n=93), the emergence of PTSD symptoms over a deployment period to a combat zone was significantly associated with alterations in DNA methylation levels at 17 genomic positions and 12 genomic regions. Evidence for mediation of the relation between combat trauma and PTSD symptoms by longitudinal changes in DNA methylation was observed at several positions and regions. Bioinformatic analyses of the reported associations identified significant enrichment in several pathways relevant for symptoms of PTSD. Targeted analyses of the significant findings from the discovery sample in an independent prospective cohort of male US marines (n=98) replicated the observed relation between decreases in DNA methylation levels and PTSD symptoms at genomic regions in ZFP57, RNF39 and HIST1H2APS2. Together, our study pinpoints three novel genomic regions where longitudinal decreases in DNA methylation across the period of exposure to combat trauma marks susceptibility for PTSD

Gestational weight gain charts for different body mass index groups for women in Europe, North America, and Oceania

BackgroundGestational weight gain differs according to pre-pregnancy body mass index and is related to the risks of adverse maternal and child health outcomes. Gestational weight gain charts for women in different pre-pregnancy body mass index groups enable identification of women and offspring at risk for adverse health outcomes. We aimed to construct gestational weight gain reference charts for underweight, normal weight, overweight, and grades 1, 2 and 3 obese women and to compare these charts with those obtained in women with uncomplicated term pregnancies.MethodsWe used individual participant data from 218,216 pregnant women participating in 33 cohorts from Europe, North America, and Oceania. Of these women, 9065 (4.2%), 148,697 (68.1%), 42,678 (19.6%), 13,084 (6.0%), 3597 (1.6%), and 1095 (0.5%) were underweight, normal weight, overweight, and grades 1, 2, and 3 obese women, respectively. A total of 138, 517 women from 26 cohorts had pregnancies with no hypertensive or diabetic disorders and with term deliveries of appropriate for gestational age at birth infants. Gestational weight gain charts for underweight, normal weight, overweight, and grade 1, 2, and 3 obese women were derived by the Box-Cox t method using the generalized additive model for location, scale, and shape.ResultsWe observed that gestational weight gain strongly differed per maternal pre-pregnancy body mass index group. The median (interquartile range) gestational weight gain at 40weeks was 14.2kg (11.4-17.4) for underweight women, 14.5kg (11.5-17.7) for normal weight women, 13.9kg (10.1-17.9) for overweight women, and 11.2kg (7.0-15.7), 8.7kg (4.3-13.4) and 6.3kg (1.9-11.1) for grades 1, 2, and 3 obese women, respectively. The rate of weight gain was lower in the first half than in the second half of pregnancy. No differences in the patterns of weight gain were observed between cohorts or countries. Similar weight gain patterns were observed in mothers without pregnancy complications.ConclusionsGestational weight gain patterns are strongly related to pre-pregnancy body mass index. The derived charts can be used to assess gestational weight gain in etiological research and as a monitoring tool for weight gain during pregnancy in clinical practice

Gestational weight gain charts for different body mass index groups for women in Europe, North America and Oceania

Background: Gestational weight gain differs according to pre-pregnancy body mass index and is related to the risks of adverse maternal and child health outcomes. Gestational weight gain charts for women in different pre-pregnancy body mass index groups enable identification of women and offspring at risk for adverse health outcomes. We aimed to construct gestational weight gain reference charts for underweight, normal weight, overweight, and grade 1, 2 and 3 obese women and compare these charts with those obtained in women with uncomplicated term pregnancies.Methods: We used individual participant data from 218,216 pregnant women participating in 33 cohorts from Europe, North America and Oceania. Of these women, 9,065 (4.2%), 148,697 (68.1%), 42,678 (19.6%), 13,084 (6.0%), 3,597 (1.6%), and 1,095 (0.5%) were underweight, normal weight, overweight, and grade 1, 2 and 3 obese women, respectively. A total of 138, 517 women from 26 cohorts had pregnancies with no hypertensive or diabetic disorders and with term deliveries of appropriate for gestational age at birth infants. Gestational weight gain charts for underweight, normal weight, overweight, and grade 1, 2 and 3 obese women were derived by the Box-Cox t method using the generalized additive model for location, scale and shape. Results: We observed that gestational weight gain strongly differed per maternal pre-pregnancy body mass index group. The median (interquartile range) gestational weight gain at 40 weeks was 14.2 kg (11.4-17.4) for underweight women, 14.5 kg (11.5-17.7) for normal weight women, 13.9 kg (10.1-17.9) for overweight women, and 11.2 kg (7.0-15.7), 8.7 kg (4.3-13.4) and 6.3 kg (1.9-11.1) for grade 1, 2 and 3 obese women, respectively. The rate of weight gain was lower in the first half than in the second half of pregnancy. No differences in the patterns of weight gain were observed between cohorts or countries. Similar weight gain patterns were observed in mothers without pregnancy complications.Conclusions: Gestational weight gain patterns are strongly related to pre-pregnancy body mass index. The derived charts can be used to assess gestational weight gain in etiological research and as a monitoring tool for weight gain during pregnancy in clinical practice

Anthropogenic intensification of short-duration rainfall extremes

Short- duration (1-3 h) rainfall extremes can cause serious damage to societies through rapidly developing (flash) flooding and are determined by complex, multifaceted processes that are altering as Earth's climate warms. In this Review, we examine evidence from observational, theoretical and modelling studies for the intensification of these rainfall extremes, the drivers and the impact on flash flooding. Both short- duration and long- duration (\textgreater1 day) rainfall extremes are intensifying with warming at a rate consistent with the increase in atmospheric moisture (~7% K-1), while in some regions, increases in short- duration extreme rainfall intensities are stronger than expected from moisture increases alone. These stronger local increases are related to feedbacks in convective clouds, but their exact role is uncertain because of the very small scales involved. Future extreme rainfall intensification is also modulated by changes to temperature stratification and large- scale atmospheric circulation. The latter remains a major source of uncertainty. Intensification of short- duration extremes has likely increased the incidence of flash flooding at local scales and this can further compound with an increase in storm spatial footprint to considerably increase total event rainfall. These findings call for urgent climate change adaptation measures to manage increasing flood risks

Methods for significance testing of categorical covariates in logistic regression models after multiple imputation:Power and applicability analysis

Background: Multiple imputation is a recommended method to handle missing data. For significance testing after multiple imputation, Rubin's Rules (RR) are easily applied to pool parameter estimates. In a logistic regression model, to consider whether a categorical covariate with more than two levels significantly contributes to the model, different methods are available. For example pooling chi-square tests with multiple degrees of freedom, pooling likelihood ratio test statistics, and pooling based on the covariance matrix of the regression model. These methods are more complex than RR and are not available in all mainstream statistical software packages. In addition, they do not always obtain optimal power levels. We argue that the median of the p-values from the overall significance tests from the analyses on the imputed datasets can be used as an alternative pooling rule for categorical variables. The aim of the current study is to compare different methods to test a categorical variable for significance after multiple imputation on applicability and power. Methods: In a large simulation study, we demonstrated the control of the type I error and power levels of different pooling methods for categorical variables. Results: This simulation study showed that for non-significant categorical covariates the type I error is controlled and the statistical power of the median pooling rule was at least equal to current multiple parameter tests. An empirical data example showed similar results. Conclusions: It can therefore be concluded that using the median of the p-values from the imputed data analyses is an attractive and easy to use alternative method for significance testing of categorical variables

Specific agreement on ordinal and multiple nominal outcomes can be calculated for more than two raters

OBJECTIVE: The concept of specific agreement has been proposed for dichotomous outcomes for two and more raters. We aim to extend this concept for variables with more than two ordinal or nominal categories and more than two raters. STUDY DESIGN AND SETTING: We used two data sets: 4 plastic surgeons classifying photographs after breast reconstruction on a 5 point ordinal scale; and 6 raters classifying psychiatric patients into 5 diagnostic categories. For m raters, all (i.e. m(m-1)/2) pairwise agreement tables were summed to calculate the observed agreement, specific agreement and conditional probabilities. The 95% confidence intervals were obtained by bootstrapping. RESULTS: Specific agreement was calculated for each ordinal or nominal category to examine when one of the raters scored in a specific category, what is the probability that the other raters scored in that same category. And suppose one of the raters scored X1, what is the probability that the other raters scored X1 or any of the other categories (conditional probability). It appeared for example that among the psychiatric disorders, depression and personality disorders were often mixed up, while neurosis was rarely mixed up with schizophrenia. CONCLUSION: The concept of specific agreement for variables with ordinal and multiple nominal categories provides relevant clinical information. The extension to conditional probabilities of alternative categories broadens the clinical application with examining which categories are most often mixed up