Null vectors of the WBC2WBC_2 algebra

Using the fusion principle of Bauer et al. we give explicit expressions for some null vectors in the highest weight representations of the \bc algebra in two different forms. These null vectors are the generalization of the Virasoro ones described by Benoit and Saint-Aubin and analogues of the $W_3$ ones constructed by Bowcock and Watts. We find connection between quantum Toda models and the fusion method.Comment: 8 pages, LaTeX, ITP Budapest 50

Alien Registration- Dubois, Benoit Z. (Sanford, York County)

https://digitalmaine.com/alien_docs/2684/thumbnail.jp

Structural properties of a calcium aluminosilicate glass from molecular-dynamics simulations: A finite size effects study

We study a calcium aluminosilicate glass of composition (SiO$_2$)$_{0.67}$-(Al$_2$O$_3$)$_{0.12}$-(CaO)$_{0.21}$ by means of molecular-dynamics (MD) simulations, using a potential made of two-body and three-body interactions. In order to prepare small samples that can subsequently be studied by first-principles, the finite size effects on the liquid dynamics and on the glass structural properties are investigated. We find that finite size effects affect the Si-O-Si and Si-O-Al angular distributions, the first peaks of the Si-O, Al-O and Ca-O pair correlation functions, the Ca coordination and the oxygen atoms environment in the smallest system (100 atoms). We give evidence that these finite size effects can be directly attributed to the use of three-body interactions.Comment: 36 pages, 14 figures. Journal of Chem. Phys., in pres

Magnetic structure of the antiferromagnetic half-Heusler compound NdBiPt

We present results of single crystal neutron diffraction experiments on the rare-earth, half-Heusler antiferromagnet (AFM) NdBiPt. This compound exhibits an AFM phase transition at $T_{\mathrm N}=2.18$~K with an ordered moment of $1.78(9)$~$\mu_{\mathrm B}$ per Nd atom. The magnetic moments are aligned along the $[001]$-direction, arranged in a type-I AFM structure with ferromagnetic planes, alternating antiferromagnetically along a propagation vector $\tau$ of $(100)$. The $R$BiPt ($R$= Ce-Lu) family of materials has been proposed as candidates of a new family of antiferromagnetic topological insulators (AFTI) with magnetic space group that corresponds to a type-II AFM structure where ferromagnetic sheets are stacked along the space diagonal. The resolved structure makes it unlikely, that NdBiPt qualifies as an AFTI.Comment: As resubmitted to PRB, corrected typos and changed symbols in Fig.

Profil de sensibilisation aux allergènes des asthmatiques adultes à Kinshasa, RDC : Etude transversale par prick-tests: Allergen sensitization profile of adult asthmatics in Kinshasa, DRC: Cross-sectional study by prick-tests

Context. Atopy is a common feature of asthma, involving near 80% of patients. Allergen sensitization shows environmental and geographical variability worldwide. Objective. To determine the common allergen sensitization profile of adult asthmatics in Kinshasa. Methods. From June 2017 to February 2018, 216 asthmatics aged 18 and over, of both sexes, were consecutively recruited at the University Clinics of Kinshasa and in some parishes and churches around the same town. The socio-demographic variables were registered using a validated questionnaire. The prick-test was performed relaying on five standardized commercial extracts of dog and cat dander, house dust mite (Blomia tropicalis, Bt), molds (Alternaria alternata), and egg yolk. Results. The population, average age of 45.23 (SD=17.56) years, 74% female, was sensitized at least to one allergen (53%) and non -sensitized in 47%. Twenty-five percent were monosensitized and 27% plurisensitized. The sensitization profile was respectively to Blomia tropicalis (72%), cat dander (46%), dog dander (34%), Alternaria alternata (13%) and egg yolk (11%). Conclusion. The present study indicates a plurisentisization feature in many asthmatics in our milieu ; mainly to dust mites and cat dander. Futher investigations involving a larger number of subjects and using broader test batteries are needed to improve diagnostic and therapeutic approaches in our context. Contexte. Environ 80% des asthmatiques sont atopiques. La sensibilisation aux allergènes communs présente certaines variabilités environnementales et géographiques. Objectif. Déterminer le profil de sensibilisation aux allergènes communs des asthmatiques adultes de la ville de Kinshasa. Méthodes. De juin 2017 à février 2018, 216 asthmatiques de 18 ans et plus, des 2 sexes, ont été consécutivement recrutés aux Cliniques Universitaires de Kinshasa et dans certaines paroisses et églises de réveil de la ville de Kinshasa. A l’aide d’un questionnaire validé, les variables sociodémographiques ont été précisées. Le prick-test a été réalisé avec cinq extraits commerciaux standardisés de phanères de chien et chat, l’acarien de poussière de maison (Blomia tropicalis, Bt), les moisissures (Alternaria alternata), et le jaune d’oeuf. Résultats. L’âge moyen de la population était de 45,23 (ET=17,56) ans, 74% de sexe féminin, 47 % non sensibilisés et 53% sensibilisés à au moins un allergène. Vingt-cinq pourcent étaient monosensibilisées et 27% plurisensibilisées. Le profil de sensibilisation était Blomia tropicalis (72%), phanères de chat (46%), phanères de chien (34%), Alternaria alternata (13%) et jaune d’oeuf (11%). Conclusion. Une plurisensibilisation aux allergènes communs chez les asthmatiques dans notre milieu est présente dont le profil dominé par les acariens et les phanères de chats. Des enquêtes futures incluant un plus grand nombre de sujets et recourant à des batteries de tests plus élargies s’imposent en vue d’une définition d’options diagnostiques et thérapeutiques dans notre contexte

Incommensurate magnetic structure of CeRhIn5

The magnetic structure of the heavy fermion antiferromagnet CeRhIn5 is determined using neutron diffraction. We find a magnetic wave vector q_M=(1/2,1/2,0.297), which is temperature independent up to T_N=3.8K. A staggered moment of 0.374(5) Bohr magneton at 1.4K, residing on the Ce ion, spirals transversely along the c axis. The nearest neighbor moments on the tetragonal basal plane are aligned antiferromagnetically.Comment: 4 pages, 4 figures There was an extra factor of 2 in Eq (2). This affects the value of staggered moment. The correct staggered moment is 0.374(5) Bohr magneton at 1.4

Relaxation processes in harmonic glasses?

A relaxation process, with the associated phenomenology of sound attenuation and sound velocity dispersion, is found in a simulated harmonic Lennard-Jones glass. We propose to identify this process with the so called microscopic (or instantaneous) relaxation process observed in real glasses and supercooled liquids. A model based on the memory function approach accounts for the observation, and allows to relate to each others: 1) the characteristic time and strength of this process, 2) the low frequency limit of the dynamic structure factor of the glass, and 3) the high frequency sound attenuation coefficient, with its observed quadratic dependence on the momentum transfer.Comment: 11 pages, 3 figure

Expression of FGF-2 in neural progenitor cells enhances their potential for cellular brain repair in the rodent cortex

Strategies to enhance the capacity of grafted stem/progenitors cells to generate multipotential, proliferative and migrating pools of cells in the postnatal brain could be crucial for structural repair after brain damage. We investigated whether the over-expression of basic fibroblast growth factor 2 (FGF-2) in neural progenitor cells (NPCs) could provide a robust source of migrating NPCs for tissue repair in the rat cerebral cortex. Using live imaging we provide direct evidence that FGF-2 over-expression significantly enhances the migratory capacity of grafted NPCs in complex 3D structures, such as cortical slices. Furthermore, we show that the migratory as well as proliferative properties of FGF-2 over-expressing NPCs are maintained after in vivo transplantation. Importantly, after transplantation into a neonatal ischaemic cortex, FGF-2 over-expressing NPCs efficiently invade the injured cortex and generate an increased pool of immature neurons available for brain repair. Differentiation of progenitor cells into immature neurons was correlated with a gradual down-regulation of the FGF-2 transgene. These results reveal an important role for FGF-2 in regulating NPCs functions when interacting with the host tissue and offer a potential strategy to generate a robust source of migrating and immature progenitors for repairing a neonatal ischaemic corte

Rubber Impact on 3D Textile Composites

A low velocity impact study of aircraft tire rubber on 3D textile-reinforced composite plates was performed experimentally and numerically. In contrast to regular unidirectional composite laminates, no delaminations occur in such a 3D textile composite. Yarn decohesions, matrix cracks and yarn ruptures have been identified as the major damage mechanisms under impact load. An increase in the number of 3D warp yarns is proposed to improve the impact damage resistance. The characteristic of a rubber impact is the high amount of elastic energy stored in the impactor during impact, which was more than 90% of the initial kinetic energy. This large geometrical deformation of the rubber during impact leads to a less localised loading of the target structure and poses great challenges for the numerical modelling. A hyperelastic Mooney-Rivlin constitutive law was used in Abaqus/Explicit based on a step-by-step validation with static rubber compression tests and low velocity impact tests on aluminium plates. Simulation models of the textile weave were developed on the meso- and macro-scale. The final correlation between impact simulation results on 3D textile-reinforced composite plates and impact test data was promising, highlighting the potential of such numerical simulation tools