Nonlinear normal modes, modal interactions and isolated resonance curves

The objective of the present study is to explore the connection between the nonlinear normal modes of an undamped and unforced nonlinear system and the isolated resonance curves that may appear in the damped response of the forced system. To this end, an energy balancing technique is used to predict the amplitude of the harmonic forcing that is necessary to excite a specific nonlinear normal mode. A cantilever beam with a nonlinear spring at its tip serves to illustrate the developments. The practical implications of isolated resonance curves are also discussed by computing the beam response to sine sweep excitations of increasing amplitudes.Comment: Journal pape

Using fine-scale field data modelling for planning the management of invasions of Oenothera stucchii in coastal dune systems

Invasive alien species risk assessment and adaptive management are often hindered by a lack of information for most species. This work aims at predicting the probability of successful establishment and invasion of Oenothera stucchii Soldano, a neophyte invasive species belonging to the sect. Oenothera subsect. Oenothera, in xerophilous grasslands of grey dunes. Based on fine-scale field data, we modelled O. stucchii presence/absence and abundance as a function of environmental factors, human disturbance, and attributes of the recipient community through a zero-inflated Poisson model. The invasion success of O. stucchii depended on a combination of factors which differed when considering either the patterns of occurrence (species presence/absence) or those of species abundance. While human-driven disturbance strongly influenced the probability of presence/absence of O. stucchii, patterns of abundance were mostly driven by a combination of environmental and biotic features. Attributes of the recipient community remarkably influenced both O. stucchii presence and abundance. Based on fine-scale field data, we determined the mechanisms which drive the spatial patterns of presence and abundance of O. stucchii in xerophilous grasslands and provided quantitative thresholds to identify the most susceptible areas of grey dune habitats prone to invasion, which combine human disturbance (distance from the nearest beach access), attributes of the resident community (resident vegetation cover and structure), and environmental disturbance (foredune ridge height). These results provide useful insights to be used to plan cost-effective measures to prevent O. stucchii establishment and spread in sandy coastal systems. Our model may also be applied to closely related congener species included in the subsect. Oenothera, sharing similar biological and ecological traits

The Clermont radiometric reference rocks: a convenient tool for dosimetric purposes

soumis à Ancient TLBoreholes drilled in 8 different rocks situated in the vicinity of the Clermont TL laboratory have been used for testing and calibrating methods devoted to measure the natural radioactivity. The present paper gives updated data for the nuclide contents and internal dose-rates for those reference media. Two examples of application are presented. The first example shows dose-rate calibration of a scintillator gamma probe using a threshold method. The second example shows a routine technique for TL dosimetry, based on the rocks for dose-rate reference

Modeling Boundary Layer Ingestion Using a Coupled Aeropropulsive Analysis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143109/1/1.C034601.pd

High Rates of Potentially Infectious Tuberculosis and Multidrug-Resistant Tuberculosis (MDR-TB) among Hospital Inpatients in KwaZulu Natal, South Africa Indicate Risk of Nosocomial Transmission

Background: Nosocomial transmission has been implicated as a key factor in the outbreak of extensively drug resistant (XDR) and multidrug-resistant (MDR-TB) tuberculosis at Church of Scotland Hospital (CoSH), in KwaZulu-Natal (KZN), South Africa. The aim of this study was to quantify the burden of potentially infectious tuberculosis and the proportion of drug resistance among hospital inpatients throughout the province of KZN. Methods: Inpatients with current cough, capable of producing sputum were selected from 19 public hospitals in KZN. After informed consent, demographic and clinical data, and sputum samples were collected. Samples were processed for fluorescent microscopy, liquid culture and first and second-line anti-tuberculosis drug susceptibility testing. Results: There were a total of 2,964 inpatients where sampling was done. About 1,585 inpatients (53%) had a current cough and sufficient microbiological and clinical data for inclusion. Mycobacterium tuberculosis was isolated from 543 inpatients (34% of those tested and 18% of all inpatients). Eighty-four (15%) inpatients with TB were found to be MDR-TB infected and 16 (3%) had XDR-TB. There was no association between the prevalence of MDR-TB and proximity to CoSH. Among patients with microbiologically confirmed TB, MDR/XDR-TB was associated with male sex, a longer length of stay between hospital admission and date of sample collection, and current or previous TB treatment. Conclusions: One in five inpatients had potentially infectious TB. This is an underestimate since patients without current cough were not tested. MDR-TB was frequently observed and was found in nearly one in six active TB inpatients. While present at lower levels than the original outbreak report at CoSH, XDR-TB was detected in hospitals throughout KZN. The high burden of potentially infectious TB and confirmed MDR-TB, much of it undiagnosed, indicates a serious risk for nosocomial transmission and the need for intensified infection control within the inpatient setting

Aeropropulsive Design Optimization of a Turboelectric Boundary Layer Ingestion Propulsion System

Boundary Layer Ingestion (BLI) for aircraft applications was first proposed by Apollo Smith and Howard Roberts in a 1947 paper that studied the use of jet intakes embedded in the boundary layer as a means to maintain laminar flow and reduce aircraft drag. While the use of BLI in aviation didn't catch on it was heavily studied and utilized for marine applications. In 1993 interest in BLI applications to aircraft design was renewed when Leyroy Smith published novel work using a boundary layer analysis combined with basic propulsion modeling to show the potential for significant fuel burn reduction. Smith identified the tightly coupled aero-propulsive nature of BLI as a key challenge in the analysis and design of the concept

RENEB Inter-Laboratory comparison 2017: limits and pitfalls of ILCs

Abstract Purpose In case of a mass-casualty radiological event, there would be a need for networking to overcome surge limitations and to quickly obtain homogeneous results (reported aberration frequencies or estimated doses) among biodosimetry laboratories. These results must be consistent within such network. Inter-laboratory comparisons (ILCs) are widely accepted to achieve this homogeneity. At the European level, a great effort has been made to harmonize biological dosimetry laboratories, notably during the MULTIBIODOSE and RENEB projects. In order to continue the harmonization efforts, the RENEB consortium launched this intercomparison which is larger than the RENEB network, as it involves 38 laboratories from 21 countries. In this ILC all steps of the process were monitored, from blood shipment to dose estimation. This exercise also aimed to evaluate the statistical tools used to compare laboratory performance. Materials and methods Blood samples were irradiated at three different doses, 1.8, 0.4 and 0 Gy (samples A, C and B) with 4-MV X-rays at 0.5 Gy min−1, and sent to the participant laboratories. Each laboratory was requested to blindly analyze 500 cells per sample and to report the observed frequency of dicentric chromosomes per metaphase and the corresponding estimated dose. Results This ILC demonstrates that blood samples can be successfully distributed among laboratories worldwide to perform biological dosimetry in case of a mass casualty event. Having achieved a substantial harmonization in multiple areas among the RENEB laboratories issues were identified with the available statistical tools, which are not capable to advantageously exploit the richness of results of a large ILCs. Even though Z- and U-tests are accepted methods for biodosimetry ILCs, setting the number of analyzed metaphases to 500 and establishing a tests’ common threshold for all studied doses is inappropriate for evaluating laboratory performance. Another problem highlighted by this ILC is the issue of the dose-effect curve diversity. It clearly appears that, despite the initial advantage of including the scoring specificities of each laboratory, the lack of defined criteria for assessing the robustness of each laboratory’s curve is a disadvantage for the ‘one curve per laboratory’ model. Conclusions Based on our study, it seems relevant to develop tools better adapted to the collection and processing of results produced by the participant laboratories. We are confident that, after an initial harmonization phase reached by the RENEB laboratories, a new step toward a better optimization of the laboratory networks in biological dosimetry and associated ILC is on the way.AFRRI’s-RBB44313 y AFR-B4-431

Suppression Aeroelastic Instability Using Broadband Passive Targeted Energy Transfers, Part 1: Theory

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76103/1/AIAA-24062-636.pd

SLC35A2-related congenital disorder of glycosylation : Defining the phenotype

We aim to further delineate the phenotype associated with pathogenic variants in the SLC35A2 gene, and review all published literature to-date. This gene is located on the X chromosome and encodes a UDP-galactose transporter. Pathogenic variants in SLC35A2 cause a congenital disorder of glycosylation. The condition is rare, and less than twenty patients have been reported to-date. The phenotype is complex and has not been fully defined. Here, we present a series of five patients with de novo pathogenic variants in SLC35A2. The patients' phenotype includes developmental and epileptic encephalopathy with hypsarrhythmia, facial dysmorphism, severe intellectual disability, skeletal abnormalities, congenital cardiac disease and cortical visual impairment. Developmental and epileptic encephalopathy with hypsarrhythmia is present in most patients with SLC35A2 variants, and is drug-resistant in the majority of cases. Adrenocorticotropic hormone therapy may achieve partial or complete remission of seizures, but the effect is usually temporary. Isoelectric focusing of transferrins may be normal after infancy, therefore a congenital disorder of glycosylation should still be considered as a diagnosis in the presence of a suggestive phenotype. We also provide evidence that cortical visual impairment is part of the phenotypic spectrum. (C) 2018 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.Peer reviewe