486 research outputs found
The projection of a nonlocal mechanical system onto the irreversible generalized Langevin equation, II: Numerical simulations
The irreversible generalized Langevin equation (iGLE) contains a
nonstationary friction kernel that in certain limits reduces to the GLE with
space-dependent friction. For more general forms of the friction kernel, the
iGLE was previously shown to be the projection of a mechanical system with a
time-dependent Hamiltonian. [R. Hernandez, J. Chem. Phys. 110, 7701 (1999)] In
the present work, the corresponding open Hamiltonian system is further
explored. Numerical simulations of this mechanical system illustrate that the
time dependence of the observed total energy and the correlations of the
solvent force are in precise agreement with the projected iGLE.Comment: 8 pages, 9 figures, submitted to J. Chem. Phy
Chemical composition of aquatic dissolved organic matter in five boreal forest catchments sampled in spring and fall seasons
The chemical composition and carbon isotope signature of aquatic dissolved organic matter (DOM) in five boreal forest catchments in Scandinavia were investigated. The DOM was isolated during spring and fall seasons using a reverse osmosis technique. The DOM samples were analyzed by elemental analysis, FT-IR, solid-state CP-MAS 13C-NMR, and C-1s NEXAFS spectroscopy. In addition, the relative abundance of carbon isotopes (12C, 13C, 14C) in the samples was measured. There were no significant differences in the chemical composition or carbon isotope signature of the DOM sampled in spring and fall seasons. Also, differences in DOM composition between the five catchments were minor. Compared to reference peat fulvic and humic acids, all DOM samples were richer in O-alkyl carbon and contained less aromatic and phenolic carbon, as shown by FT-IR, 13C-NMR, and C-1s NEXAFS spectroscopy. The DOM was clearly enriched in 14C relative to the NBS oxalic acid standard of 1950, indicating that the aquatic DOM contained considerable amounts of organic carbon younger than about 50years. The weight-based C:N ratios of 31 ± 6 and the values of -29\pm2\permille indicate that the isolated DOM is of terrestrial rather than aquatic origin. We conclude that young, hydrophilic carbon compounds of terrestrial origin are predominant in the samples investigated, and that the composition of the aquatic DOM in the studied boreal forest catchments is rather stable during low to intermediate flow condition
Real-time vocal emotion recognition in artistic installations and interactive storytelling: Experiences and lessons learnt from CALLAS and IRIS
Most emotion recognition systems still rely exclusively on prototypical emotional vocal expressions that may be uniquely assigned to a particular class. In realistic applications, there is, however, no guarantee that emotions are expressed in a prototypical manner. In this paper, we report on challenges that arise when coping with non-prototypical emotions in the context of the CALLAS project and the IRIS network. CALLAS aims to develop interactive art installations that respond to the multimodal emotional input of performers and spectators in real-time. IRIS is concerned with the development of novel technologies for interactive storytelling. Both research initiatives represent an extreme case of non-prototypicality since neither the stimuli nor the emotional responses to stimuli may be considered as prototypical. 1
Nonsense-Mediated Decay Restricts LncRNA Levels in Yeast Unless Blocked by Double-Stranded RNA Structure
International audienceAntisense long non-coding (aslnc)RNAs represent a substantial part of eukaryotic transcriptomes that are, in yeast, controlled by the Xrn1 exonuclease. Nonsense-Mediated Decay (NMD) destabilizes the Xrn1-sensitive aslncRNAs (XUT), but what determines their sensitivity remains unclear. We report that 3′ single-stranded (3′-ss) extension mediates XUTs degradation by NMD, assisted by the Mtr4 and Dbp2 helicases. Single-gene investigation, genome-wide RNA analyses, and double-stranded (ds)RNA mapping revealed that 3′-ss extensions discriminate the NMD-targeted XUTs from stable lncRNAs. Ribosome profiling showed that XUT are translated, locking them for NMD activity. Interestingly, mutants of the Mtr4 and Dbp2 helicases accumulated XUTs, suggesting that dsRNA unwinding is a critical step for degradation. Indeed, expression of anticomplementary transcripts protects cryptic intergenic lncRNAs from NMD. Our results indicate that aslncRNAs form dsRNA that are only translated and targeted to NMD if dissociated by Mtr4 and Dbp2. We propose that NMD buffers genome expression by discarding pervasive regulatory transcripts
Affective interactive narrative in the CALLAS Project
This full text version, available on TeesRep, is the post-print (final version prior to publication) of
Dimensionnement parasismique
Cours d'introduction Ă la norme SIA 26
Application of a new ray tracing framework to the analysis of extended regions in Si solar cell modules
While ray tracing of solar cells was established decades ago, ray tracing of entire modules has met obstacles, mainly because module optics are affected by geometric structures varying over a large scale of dimensions. In this paper, we introduce a ray tracing framework that is based on a modular structure made up of separate plugins. While existing plugins can be used for common effects such as light sources, absorption in materials, etc., specialized plug-ins can be written by users to handle problem-specific properties. We demonstrate the functionality of our approach by ray tracing a test module containing 9 crystalline Si solar cells. Good agreement between light-beam induced current (LBIC) measurements and ray tracing is achieved
A Paramagnetic NMR Spectroscopy Toolbox for the Characterisation of Paramagnetic/Spin-Crossover Coordination Complexes and Metal-Organic Cages
The large paramagnetic shifts and short relaxation times resulting from the presence of a paramagnetic centre complicate NMR data acquisition and interpretation in solution. As a result, NMR analysis of paramagnetic complexes is limited in comparison to diamagnetic compounds and often relies on theoretical models. We report a toolbox of 1D (1H, proton-coupled 13C, selective 1H-decoupling 13C, steady-state NOE) and 2D (COSY, NOESY, HMQC) paramagnetic NMR methods that enables unprecedented structural characterisation and in some cases, provides more structural information than would be observable for a diamagnetic analogue. We demonstrate the toolbox's broad versatility for fields from coordination chemistry and spin-crossover complexes to supramolecular chemistry through the characterisation of CoII and high-spin FeII mononuclear complexes as well as a Co4L6 cage
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