Detailed investigation of overwash on a gravel barrier

This paper uses results obtained from a prototype-scale experiment (Barrier Dynamics Experiment; BARDEX) undertaken in the Delta flume, the Netherlands, to investigate overwash hydraulics and morphodynamics of a prototype gravel barrier. Gravel barrier behaviour depends upon a number of factors, including sediment properties (porosity, permeability, grain-size) and wave climate. Since overwash processes are known to control short-term gravel barrier dynamics and long-term barrier migration, a detailed quantification of overwash flow properties and induced bed-changes is crucial. Overwash hydrodynamics of the prototype gravel barrier focused on the flow velocity, depth and discharge over the barrier crest, and the overwash flow progression across and the infiltration through the barrier. During the BARDEX experiment, overwash peak depth (0.77 m), velocity (5 m s−1 ) and discharge (max. 6 m3 m−1 ) were high, especially considering the relatively modest wave energy (significant wave height = 0.8 m). Conversely to schemes found in the literature, average flow depth did not linearly decrease across the barrier; rather, it was characterised by a sudden decrease at the crest, a milder decrease at the barrier top and then propagation as a shallow water lens over the backbarrier. The barrier morphological evolution was analysed over a series of 15-min experimental runs and at the timescale of individual overwash events. Overall, the morphological variation did not result from an accumulation of many small consistently erosive or accretionary events, but rather the mean bed elevation change per event was quite large (10 mm) and the overall morphology change occurred due to a small imbalance in the number of erosive and accretionary events at each location. Two relationships between overwash hydrodynamic variables were deduced from results: (1) between overwash flow depth and velocity a power-type relation was obtained; and (2) a linear relation was observed between overwash flow depth and maximum overwash intrusion distance across the barrier top (i.e. overwash intrusion). Findings from this study are useful to enhance the knowledge of overwash processes and also have practical applications. On the one hand, results shown here can be use for the validation of overwash predictive models, and additionally, the simple empirical relations deduced from the dataset can be used by coastal managers to estimate overwash intrusion distance, which in turn can assist in the location of areas under risk of overwash and breaching.N/

Wave runup and overwash on a prototype-scale sand barrier

Accurate methods to predict wave runup are of critical importance to coastal engineers. Extreme runup during storm conditions can present a danger to coastal infrastructure and lead to dune overtopping and erosion, overwash. of barrier beaches and is an essential design parameter for certain coastal protection works. This paper uses data obtained during the unique BARDEX II prototype-scale laboratory experiment on a reflective sand barrier to investigate wave runup and overwash. Runup measurements were acquired using ultrasonic altimeters, 2D scanning Lidar and camera systems under controlled wave and water level conditions. It was found that extreme runup (R-2%) scaled well with the deepwater Irribarren number where the beach slope was taken to be the beach face gradient. The lower limit of the swash zone, defined by the 2% wave rundown limit was also found to be a function of the Irribarren number and was consistently below the SWL in all tests. The high resolution free-surface measurements obtained using the ultrasonic altimeters and Lidar enabled an analysis of the dynamics of individual swash events. It was found that the vertical runup excursion of each swash correlated strongly with the height of the bore at collapse, and could be predicted based on the assumption of a conversion of potential to kinetic energy at bore collapse. (C) 2015 Elsevier B.V. All rights reserved

Enchantment - Disenchantment-Re-Enchantment: Postdigital Relationships between Science, Philosophy, and Religion

This collectively written article explores postdigital relationships between science, philosophy, and religion within the continuum of enchantment, disenchantment, and re-enchantment. Contributions are broadly classified within four sections related to academic fields of philosophy, theology, critical theory, and postdigital studies. The article reveals complex and nuanced relationships between various disciplinary perspectives, religions, and political positions, and points towards lot of commonalities between their views to the enchantment, disenchantment, re-enchantment continuum. Some commonly discussed questions include: Where do the mythical, mystical and spiritual end and the rational, objective and empirical begin? How do we find our bearings in the midst of this complexity and where do we search for resources that are trustworthy and reliable? While the article inevitably offers more questions than answers, a common thread between all contributions is the need for an open postdigital dialogue conducted in the spirit of mutual understanding and respect. It is with this conclusion that the article offers a possible route for further development of such dialogue in the future

The clinical and molecular spectrum of the KDM6B-related neurodevelopmental disorder

International audienceDe novo variants are a leading cause of neurodevelopmental disorders (NDDs), but because every monogenic NDD is different and usually extremely rare, it remains a major challenge to understand the complete phenotype and genotype spectrum of any morbid gene. According to OMIM, heterozygous variants in KDM6B cause "neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities." Here, by examining the molecular and clinical spectrum of 85 reported individuals with mostly de novo (likely) pathogenic KDM6B variants, we demonstrate that this description is inaccurate and potentially misleading. Cognitive deficits are seen consistently in all individuals, but the overall phenotype is highly variable. Notably, coarse facies and distal skeletal anomalies, as defined by OMIM, are rare in this expanded cohort while other features are unexpectedly common (e.g., hypotonia, psychosis, etc.). Using 3D protein structure analysis and an innovative dual Drosophila gain-of-function assay, we demonstrated a disruptive effect of 11 missense/in-frame indels located in or near the enzymatic JmJC or Zn-containing domain of KDM6B. Consistent with the role of KDM6B in human cognition, we demonstrated a role for the Drosophila KDM6B ortholog in memory and behavior. Taken together, we accurately define the broad clinical spectrum of the KDM6B-related NDD, introduce an innovative functional testing paradigm for the assessment of KDM6B variants, and demonstrate a conserved role for KDM6B in cognition and behavior. Our study demonstrates the critical importance of international collaboration, sharing of clinical data, and rigorous functional analysis of genetic variants to ensure correct disease diagnosis for rare disorders