1,038 research outputs found
Protracted fluid-induced melting during Barrovian metamorphism in the Central Alps
The timing and dynamics of fluid-induced melting in the typical Barrovian sequence of the Central Alps has been investigated using zircon chronology and trace element composition. Multiple zircon domains in leucosomes and country rocks yield U-Pb ages spanning from ∼32 to 22 Ma. The zircon formed during Alpine melting can be distinguished from the inherited and detrital cores on the basis of their age, Th/U (<0.1) and trace element composition. Ti-in-zircon thermometry indicates crystallization temperatures around 620-700°C. Their composition allows discriminating between (1) zircon formation in the presence of early garnet, (2) zircon in equilibrium with abundant L-MREE-rich accessory phases (allanite, titanite and apatite) typical of metatonalites, and (3) zircon formed during melting of metasediments in feldspar-dominated assemblages. The distribution of zircon overgrowths and ages indicate that repeated melting events occurred within a single Barrovian metamorphic cycle at roughly constant temperature; that in the country rocks zircon formation was limited to the initial stages of melting, whereas further melting concentrated in the segregated leucosomes; that melting occurred at different times in samples a few meters apart because of the local rock composition and localized influx of the fluids; and that leucosomes were repeatedly melted when fluids became available. The geochronological data force a revision of the temperature-time path of the migmatite belt in the Central Alps. Protracted melting over 10 My followed the fast exhumation of Alpine eclogites contained within the same region and preceded fast cooling in the order of 100°C/Ma to upper crustal levels
RASR2: The RWTH ASR Toolkit for Generic Sequence-to-sequence Speech Recognition
Modern public ASR tools usually provide rich support for training various
sequence-to-sequence (S2S) models, but rather simple support for decoding
open-vocabulary scenarios only. For closed-vocabulary scenarios, public tools
supporting lexical-constrained decoding are usually only for classical ASR, or
do not support all S2S models. To eliminate this restriction on research
possibilities such as modeling unit choice, we present RASR2 in this work, a
research-oriented generic S2S decoder implemented in C++. It offers a strong
flexibility/compatibility for various S2S models, language models, label
units/topologies and neural network architectures. It provides efficient
decoding for both open- and closed-vocabulary scenarios based on a generalized
search framework with rich support for different search modes and settings. We
evaluate RASR2 with a wide range of experiments on both switchboard and
Librispeech corpora. Our source code is public online.Comment: accepted at Interspeech 202
Variations in arterial blood pressure are associated with parallel changes in FlowTrac/Vigileo®-derived cardiac output measurements: a prospective comparison study
Hyperbolic Kac-Moody Algebras and Chaos in Kaluza-Klein Models
Some time ago, it was found that the never-ending oscillatory chaotic
behaviour discovered by Belinsky, Khalatnikov and Lifshitz (BKL) for the
generic solution of the vacuum Einstein equations in the vicinity of a
spacelike ("cosmological") singularity disappears in spacetime dimensions . Recently, a study of the generalization of the BKL chaotic behaviour
to the superstring effective Lagrangians has revealed that this chaos is rooted
in the structure of the fundamental Weyl chamber of some underlying hyperbolic
Kac-Moody algebra. In this letter, we show that the same connection applies to
pure gravity in any spacetime dimension , where the relevant algebras
are . In this way the disappearance of chaos in pure gravity models in dimensions becomes linked to the fact that the Kac-Moody algebras
are no longer hyperbolic for .Comment: 13 pages, 1 figur
Renormalon Model Predictions for Power-Corrections to Flavour Singlet Deep Inelastic Structure Functions
We analyze power corrections to flavour singlet deep inelastic scattering
structure functions in the framework of the infrared renormalon model. Our
calculations, together with previous results for the non-singlet contribution,
allow to model the x-dependence of higher twist corrections to F_2, F_L and g_1
in the whole x domain.Comment: LaTeX, 25 pages, 8 eps figures included, one figure was added. Final
version for publication in Nucl.Phys.
A high throughput molecular force assay for protein-DNA interactions.
An accurate and genome-wide characterization of protein–DNA interactions such as transcription factor binding is of utmost importance for modern biology. Powerful screening methods emerged. But the vast majority of these techniques depend on special labels or markers against the ligand of interest and moreover most of them are not suitable for detecting low-affinity binders. In this article a molecular force assay is described based on measuring comparative unbinding forces of biomolecules for the detection of protein–DNA interactions. The measurement of binding or unbinding forces has several unique advantages in biological applications since the interaction between certain molecules and not the mere presence of one of them is detected. No label or marker against the protein is needed and only specifically bound ligands are detected. In addition the force-based assay permits the detection of ligands over a broad range of affinities in a crowded and opaque ambient environment. We demonstrate that the molecular force assay allows highly sensitive and fast detection of protein–DNA interactions. As a proof of principle, binding of the protein EcoRI to its DNA recognition sequence is measured and the corresponding dissociation constant in the sub-nanomolar range is determined. Furthermore, we introduce a new, simplified setup employing FRET pairs on the molecular level and standard epi-fluorescence for readout. Due to these advancements we can now demonstrate that a feature size of a few microns is sufficient for the measurement process. This will open a new paradigm in high-throughput screening with all the advantages of force-based ligand detection.
Graphical abstract: A high throughput molecular force assay for protein–DNA interaction
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