Discussion of "Development and Verification of an Analytical Solution for Forecasting Nonlinear Kinematic Flood Waves" by Sergio E. Serrano

Discussion of "Development and Verification of an Analytical Solution for Forecasting Nonlinear Kinematic Flood Waves" by Sergio E. Serrano, Journal of Hydrologic Engineering, Vol. 11, No. 4, July/August 2006, pp. 347-353 , doi 10.1061/(ASCE)1084-0699(2006)11:4(347)

A PCA spatial pattern based artificial neural network downscaling model for urban flood hazard assessment

International audienceWe present two statistical models for downscaling flood hazard indicators derived from upscaledshallow water simulations. These downscaling models are based on the decomposition of hazardindicators into linear combinations of spatial patterns obtained from a Principal ComponentAnalysis (PCA). Artificial Neural Networks (ANNs) are used to model the relationship betweenlow resolution (LR) and high resolution (HR) information drawn from hazard indicators. Inboth statistical models, the PCA features, i.e. the linear weights of the spatial patterns, of theLR hazard indicator are taken as inputs to the ANNs. In the first model, there is one ANNper HR cell where the hazard indicator is to be estimated and the output of the ANN is thehazard indicator value at that cell. In the second model, there is a single ANN for the wholeHR mesh whose outputs are the PCA features of the HR hazard indicator. An estimate of thehazard indicator is obtained by combining the ANN’s outputs with the HR spatial patterns.The two statistical downscaling models are evaluated and compared at estimating the waterdepth and the norm of the unit discharge, two common hazard indicators, on simulations fromfive synthetic urban configurations and one field-test case. Analyses are carried out in termsof relative absolute errors of the statistical downscaling model with respect to the LR hazardindicator. They show that (i) both statistical downscaling models provide estimates that aremore accurate than the LR hazard indicator in most cases and (ii) the second downscalingmodel yields consistently lower errors for both hazard indicators for all flow scenarios on allconfigurations considered. The statistical models are three orders of magnitude faster than HRflow simulations. Used in conjunction with upscaled flood models such as porosity models, theyappear as a promising operational alternative to direct flood hazard assessment from HR flowsimulations

Hyperbolicity preserving HLL solver for two-layer shallow-water equations applied to dam-break flows

River morphodynamics and sediment transportDebris and hyperconcentrated flow

Long-term Outcome of Hirschsprung Disease: Impact on Quality of Life and Social Condition at Adult Age

BACKGROUND: Hirschsprung disease is a rare congenital disease typically requiring surgical treatment during childhood. Quality of life and social condition at adult age can be impaired by disease-specific sequelae. OBJECTIVE: This study aimed to assess the quality of life and social outcome of adult patients operated on for Hirschsprung disease during childhood. DESIGN: Patients operated on for Hirschsprung disease during childhood were identified and specific questionnaires were sent to them. SETTINGS: Data from 2 referral centers were used. PATIENTS: Patients who completed the questionnaires regarding quality of life and social condition were included. MAIN OUTCOME MEASURES: The Hirschsprung\u27s Disease and Anorectal Malformations Quality of Life disease-specific questionnaire (8 dimensions explored; each scored from 0 to 100 maximum score) and a sociodemographic questionnaire were sent to identified patients. Sociodemographic data were compared with those of the French general population. RESULTS: Thirty-four patients had Hirschsprung disease (men, 76%; mean age, 32 years) were included in the study. Mean total Hirschsprung\u27s Disease and Anorectal Malformations Quality of Life score was 611 of 800 (maximum score 800). The 2 most impaired dimensions were "physical symptoms" and "diarrhea" (62.9/100 and 73.6/100). Fecal continence was only marginally affected (mean score, 89/100). Patients with Hirschsprung disease achieved better educational levels than the French general population. Parental and marital status did not differ between the 2 groups. LIMITATIONS: This study had the limitations inherent to a retrospective study. CONCLUSION: The quality of life of adult patients with Hirschsprung disease sequelae is marginally impaired in this study. Despite the consequences of this congenital abnormality, the condition eventually achieved can be considered as satisfactory. See Video Abstract at http://links.lww.com/DCR/A917

Deterministic Hydrological Model For Flood Risk Assessment Of Mexico City

Mexico City is facing problems of flooding in some areas at certain times of the year, causing important losses and damages on properties and residents including some casualties. Therefore, it is important to carry out a flood risk assessment in the catchment of Mexico City and estimate damages of probable flood events. However, limited data of observed discharges and water depths in the main rivers of the city are available, and this represents an obstacle for the understanding of flooding in Mexico City. The objective of the developed tool is to provide an efficient support to management of the flood processes by predicting the behavior of the catchment for different rainfall events and flood scenarios. The capability of a model based on MIKE SHE modeling system for the Mexico City catchment was evaluated by comparing the observed data and the simulation results during a year after a careful development based on the most important parameters for characterizing the processes. Significant and operational results (\u3e0.75 for Nash Sutcliffe coefficient) have been obtained on one of the major sub-catchments of the Mexico basin. These results demonstrate the interest to implement a deterministic hydrological model for assessing flood risks in a dense urban environment where data availability is limited. In addition, three methods for flood map creation are proposed to assist flood risk management

Piecewise Parabolic Method on a Local Stencil for Magnetized Supersonic Turbulence Simulation

Stable, accurate, divergence-free simulation of magnetized supersonic turbulence is a severe test of numerical MHD schemes and has been surprisingly difficult to achieve due to the range of flow conditions present. Here we present a new, higher order-accurate, low dissipation numerical method which requires no additional dissipation or local "fixes" for stable execution. We describe PPML, a local stencil variant of the popular PPM algorithm for solving the equations of compressible ideal magnetohydrodynamics. The principal difference between PPML and PPM is that cell interface states are evolved rather that reconstructed at every timestep, resulting in a compact stencil. Interface states are evolved using Riemann invariants containing all transverse derivative information. The conservation laws are updated in an unsplit fashion, making the scheme fully multidimensional. Divergence-free evolution of the magnetic field is maintained using the higher order-accurate constrained transport technique of Gardiner and Stone. The accuracy and stability of the scheme is documented against a bank of standard test problems drawn from the literature. The method is applied to numerical simulation of supersonic MHD turbulence, which is important for many problems in astrophysics, including star formation in dark molecular clouds. PPML accurately reproduces in three-dimensions a transition to turbulence in highly compressible isothermal gas in a molecular cloud model. The low dissipation and wide spectral bandwidth of this method make it an ideal candidate for direct turbulence simulations.Comment: 28 pages, 18 figure

Molecular Systematics of the Deep-Sea Hydrothermal Vent Endemic Brachyuran Family Bythograeidae: A Comparison of Three Bayesian Species Tree Methods

Brachyuran crabs of the family Bythograeidae are endemic to deep-sea hydrothermal vents and represent one of the most successful groups of macroinvertebrates that have colonized this extreme environment. Occurring worldwide, the family includes six genera (Allograea, Austinograea, Bythograea, Cyanagraea, Gandalfus, and Segonzacia) and fourteen formally described species. To investigate their evolutionary relationships, we conducted Maximum Likelihood and Bayesian molecular phylogenetic analyses, based on DNA sequences from fragments of three mitochondrial genes (16S rDNA, Cytochrome oxidase I, and Cytochrome b) and three nuclear genes (28S rDNA, the sodium–potassium ATPase a-subunit ‘NaK’, and Histone H3A). We employed traditional concatenated (i.e., supermatrix) phylogenetic methods, as well as three recently developed Bayesian multilocus methods aimed at inferring species trees from potentially discordant gene trees. We found strong support for two main clades within Bythograeidae: one comprising the members of the genus Bythograea; and the other comprising the remaining genera. Relationships within each of these two clades were partially resolved. We compare our results with an earlier hypothesis on the phylogenetic relationships among bythograeid genera based on morphology. We also discuss the biogeography of the family in the light of our results. Our species tree analyses reveal differences in how each of the three methods weighs conflicting phylogenetic signal from different gene partitions and how limits on the number of outgroup taxa may affect the results

GEC-ESTRO ACROP recommendations in skin brachytherapy

Purpose: The aim of this publication is to compile available literature data and expert experience regarding skin brachytherapy (BT) in order to produce general recommendations on behalf of the GEC-ESTRO Group. Methods: We have done an exhaustive review of published articles to look for general recommendations. Results: Randomized controlled trials, systemic reviews and meta-analysis are lacking in literature and there is wide variety of prescription techniques successfully used across the radiotherapy centers. BT can be delivered as superficial application (also called contact BT or plesiotherapy) or as interstitial for tumours thicker than 5 mm within any surface, including very irregular. In selected cases, particularly in tumours located within curved surfaces, BT can be advantageous modality from dosimetric and planning point of view when compared to external beam radiotherapy. The general rule in skin BT is that the smaller the target volume, the highest dose per fraction and the shortest overall length of treatment can be used. Conclusion: Skin cancer incidence is rising worldwide. BT offers an effective non-invasive or minimally invasive and relative short treatment that particularly appeals to elder and frail population

Shapiro Effect as a Possible Cause of the Low-Frequency Pulsar Timing Noise in Globular Clusters

A prolonged timing of millisecond pulsars has revealed low-frequency uncorrelated noise, presumably of astrophysical origin, in the pulse arrival time (PAT) residuals for some of them. In most cases, pulsars in globular clusters show a low-frequency modulation of their rotational phase and spin rate. The relativistic time delay of the pulsar signal in the curved space time of randomly distributed and moving globular cluster stars (the Shapiro effect) is suggested as a possible cause of this modulation. Given the smallness of the aberration corrections that arise from the nonstationarity of the gravitational field of the randomly distributed ensemble of stars under consideration, a formula is derived for the Shapiro effect for a pulsar in a globular cluster. The derived formula is used to calculate the autocorrelation function of the low-frequency pulsar noise, the slope of its power spectrum, and the behavior of the $\sigma_z$ statistic that characterizes the spectral properties of this noise in the form of a time function. The Shapiro effect under discussion is shown to manifest itself for large impact parameters as a low-frequency noise of the pulsar spin rate with a spectral index of n=-1.8 that depends weakly on the specific model distribution of stars in the globular cluster. For small impact parameters, the spectral index of the noise is n=-1.5.Comment: 23 pages, 6 figure