Experimental and Numerical Study of the Dispersion and Transport of Automobile Exhaust Gases from Highways

This paper describes examples of modelling and of measurements of the dispersion and transport of exhaust gases from automobiles on a highway. Model runs were performed by a large-eddy-simulation model. The measurements were carried through by the DLR environmental research aircraft lee-side of the highway between München and Augsburg

Infection kinetics and host specificity of Methicillin-resistant Staphylococcus aureus (MRSA) in pigs

In this study, we investigated the colonisation kinetics and host specificity of three different clonal lines of MRSA (ST8, ST9 and ST398). MRSA prevalence on skin, nasal mucosa, conjunctiva, feacal shedding and distribution patterns of MRSA in internal organs in weaning piglets are studied

Comprehensive miRNome-wide profiling in a neuronal cell model of synucleinopathy implies involvement of cell cycle genes

Growing evidence suggests that epigenetic mechanisms like microRNA-mediated transcriptional regulation contribute to the pathogenesis of parkinsonism. In order to study the influence of microRNAs (miRNAs), we analyzed the miRNome 2 days prior to major cell death in α-synuclein-overexpressing Lund human mesencephalic neurons, a well-established cell model of Parkinson\u27s disease (PD), by next-generation sequencing. The expression levels of 23 miRNAs were significantly altered in α-synuclein-overexpressing cells, 11 were down- and 12 upregulated

Kinetic models with randomly perturbed binary collisions

We introduce a class of Kac-like kinetic equations on the real line, with general random collisional rules, which include as particular cases models for wealth redistribution in an agent-based market or models for granular gases with a background heat bath. Conditions on these collisional rules which guarantee both the existence and uniqueness of equilibrium profiles and their main properties are found. We show that the characterization of these stationary solutions is of independent interest, since the same profiles are shown to be solutions of different evolution problems, both in the econophysics context and in the kinetic theory of rarefied gases

c.207C>G mutation in sepiapterin reductase causes autosomal dominant dopa-responsive dystonia

Objective: To elucidate the genetic cause of an Egyptian family with dopa-responsive dystonia (DRD), a childhood-onset dystonia, responding therapeutically to levodopa, which is caused by mutations in various genes. Methods: Rare variants in all coding exons of GCH1 were excluded by Sanger sequencing. Exome sequencing was applied for 1 unaffected and 2 affected family members. To investigate the functional consequences of detected genetic variants, urinary sepiapterin concentrations were determined by high-performance liquid chromatography. Results: A heterozygous rare nonsynonymous variant in exon 1 of sepiapterin reductase (SPR, c.207C>G, p.Asp69Glu) was found in all affected family members. Urinary concentrations of sepiapterin were above the standard of normal controls in most SPR mutation carriers, suggesting functional biochemical consequences of the mutation. Variant filtering of all genes involved in the tetrahydrobiopterin pathway, required for levodopa synthesis, revealed an additional common variant in dihydrofolate reductase (DHFR, rs70991108). The presence of both variants was significantly stronger associated with the biochemical abnormality and the clinical disease state as opposed to 1 variant only. Conclusions: The rare SPR mutation can cause autosomal dominant DRD with incomplete penetrance. The common DHFR variant might have synergistic effects on production of tetrahydrobiopterin and levodopa, thereby increasing penetrance

Random walk on sparse random digraphs

International audienceA finite ergodic Markov chain exhibits cutoff if its distance to equilibrium remains close to its initial value over a certain number of iterations and then abruptly drops to near 0 on a much shorter time scale. Originally discovered in the context of card shuffling (Aldous-Diaconis, 1986), this remarkable phenomenon is now rigorously established for many reversible chains. Here we consider the non-reversible case of random walks on sparse directed graphs, for which even the equilibrium measure is far from being understood. We work under the configuration model, allowing both the in-degrees and the out-degrees to be freely specified. We establish the cutoff phenomenon, determine its precise window and prove that the cutoff profile approaches a universal shape. We also provide a detailed description of the equilibrium measure

Exciton states and optical properties of CdSe nanocrystals

The optical spectra of CdSe nanocrystals up to 55 A in diameter are analyzed in a wide range of energies from the fine structure of the low-energy excitations to the so-called high-energy transitions. We apply a symmetry-based method in two steps. First we take the tight-binding (TB) parameters from the bulk sp^{3}s^{*} TB model, extended to include the spin-orbit interaction. The full single-particle spectra are obtained from an exact diagonalization by using a group-theoretical treatment. The electron-hole interaction is next introduced: Both the Coulomb (direct) and exchange terms are considered. The high-energy excitonic transitions are studied by computing the electric dipole transition probabilities between single-particle states, while the transition energies are obtained by taking into account the Coulomb interaction. The fine structure of the lowest excitonic states is analyzed by including the electron-hole exchange interaction and the wurtzite crystal-field terms in the exciton Hamiltonian. The latter is diagonalized in the single electron-hole pair excitation subspace of progressively increasing size until convergence. The peaks in the theoretical transition spectra are then used to deduce the resonant and nonresonant Stokes shifts, which are compared with their measured values in photoluminescence experiments. We find that the final results depend on the crystal-field term, the relative size of the surface and the degree of saturation of the dangling bonds. The results show a satisfactory agreement with the available experimental data.Comment: Revtex, 24 pages, 7 Postscript figure