129 research outputs found
Modelling Users, Intentions, and Structure in Spoken Dialog
We outline how utterances in dialogs can be interpreted using a partial first
order logic. We exploit the capability of this logic to talk about the truth
status of formulae to define a notion of coherence between utterances and
explain how this coherence relation can serve for the construction of AND/OR
trees that represent the segmentation of the dialog. In a BDI model we
formalize basic assumptions about dialog and cooperative behaviour of
participants. These assumptions provide a basis for inferring speech acts from
coherence relations between utterances and attitudes of dialog participants.
Speech acts prove to be useful for determining dialog segments defined on the
notion of completing expectations of dialog participants. Finally, we sketch
how explicit segmentation signalled by cue phrases and performatives is covered
by our dialog model.Comment: 17 page
Combining Expression and Content in Domains for Dialog Managers
We present work in progress on abstracting dialog managers from their domain
in order to implement a dialog manager development tool which takes (among
other data) a domain description as input and delivers a new dialog manager for
the described domain as output. Thereby we will focus on two topics; firstly,
the construction of domain descriptions with description logics and secondly,
the interpretation of utterances in a given domain.Comment: 5 pages, uses conference.st
Dynamin 2 mutations in Charcot-Marie-Tooth neuropathy highlight the importance of clathrin-mediated endocytosis in myelination
Mutations in dynamin 2 (DNM2) lead to dominant intermediate Charcot-Marie-Tooth neuropathy type B, while a different set of DNM2 mutations cause autosomal dominant centronuclear myopathy. In this study, we aimed to elucidate the disease mechanisms in dominant intermediate Charcot-Marie-Tooth neuropathy type B and to find explanations for the tissue-specific defects that are associated with different DNM2 mutations in dominant intermediate Charcot-Marie-Tooth neuropathy type B versus autosomal dominant centronuclear myopathy. We used tissue derived from Dnm2-deficient mice to establish an appropriate peripheral nerve model and found that dominant intermediate Charcot-Marie-Tooth neuropathy type B-associated dynamin 2 mutants, but not autosomal dominant centronuclear myopathy mutants, impaired myelination. In contrast to autosomal dominant centronuclear myopathy mutants, Schwann cells and neurons from the peripheral nervous system expressing dominant intermediate Charcot-Marie-Tooth neuropathy mutants showed defects in clathrin-mediated endocytosis. We demonstrate that, as a consequence, protein surface levels are altered in Schwann cells. Furthermore, we discovered that myelination is strictly dependent on Dnm2 and clathrin-mediated endocytosis function. Thus, we propose that altered endocytosis is a major contributing factor to the disease mechanisms in dominant intermediate Charcot-Marie-Tooth neuropathy type
The Adaptive Gain Integrating Pixel Detector at the European XFEL
The Adaptive Gain Integrating Pixel Detector (AGIPD) is an x-ray imager,
custom designed for the European x-ray Free-Electron Laser (XFEL). It is a
fast, low noise integrating detector, with an adaptive gain amplifier per
pixel. This has an equivalent noise of less than 1 keV when detecting single
photons and, when switched into another gain state, a dynamic range of more
than 10 photons of 12 keV. In burst mode the system is able to store 352
images while running at up to 6.5 MHz, which is compatible with the 4.5 MHz
frame rate at the European XFEL. The AGIPD system was installed and
commissioned in August 2017, and successfully used for the first experiments at
the Single Particles, Clusters and Biomolecules (SPB) experimental station at
the European XFEL since September 2017. This paper describes the principal
components and performance parameters of the system.Comment: revised version after peer revie
Report and preliminary results of SONNE cruise SO175, Miami - Bremerhaven, 12.11 - 30.12.2003 : (GAP, Gibraltar Arc Processes)
Expedition SO175 using FS Sonne aimed for a multidisciplinerary geoscientific approach with an international group of researchers. Methods covered the entire span from geophysical data acquisition (seafloor mapping, echography, seismic reflection), sediment coring at sites of active fluid venting, in situ heat flow measurements across the entire length of the Gibraltar thrust wedge, the deformation front, landslide bodies, and mud volcanoes, and finally the deployment of a long-term pore pressure probe. Video-supported operations helped to identify fluid vent sites, regions with tectonic activity, and other attractive high priority targets. Qualitative and quantitative examinations took place on board and are continued on land with respect to pore pressure variation, geomicrobiology, sediment- and fluid mobilization, geochemical processes, faunal assemblages (e.g. cold water corals), and gas hydrates (flammable methane-ice-crystals). Main focus of the expedition has been a better understanding of interaction between dynamic processes in a seismically active region region with slow plate convergence.
In the context of earthquake nucleation and subduction zone processes, the SO175 research programme had a variety of goals, such as:
• To test the frictional behaviour of the abyssal plain sediments.
• To explore the temperature field of the 1755 thrust earthquake event via heat flow measurements.
• To assess the role of fluid venting and gas hydrate processes control slope stability and mud volcanic activity along the Iberian continental margin.
• To measure isotope geochemistry of pore waters and carbonates of deep fluids.
• To quantify microbial activity in Gibraltar wedge sediments.
• To test whether microseismicity in the area corresponds to in situ pore pressure changes.
• To find out if enhanced heat flow max be indicative of active subduction.
Initial tentative results during the cruise suggest that there is a component of active thrusting at the base of the wedge, as attested by heat flow data. Based on mostly geochemical evidence, mud volcanism was found less active than previously assumed. Highlights from post-cruise research include the successful deployment of the long-term station and high frictional resistance of all incoming sediment on the three abyssal plains
Omega-3 Fatty Acids and Vitamin D in Cardiology
Dietary modification and supplementation play an increasingly important role in the conservative treatment of cardiovascular disease. Current interest has focused on n-3 polyunsaturated fatty acids (PUFA) and vitamin D. Clinical trial results on this subject are contradictory in many aspects. Several studies indicate that n-3 PUFA consumption improves vascular and cardiac hemodynamics, triglycerides, and possibly endothelial function, autonomic control, inflammation, thrombosis, and arrhythmia. Experimental studies show effects on membrane structure and associated functions, ion channel properties, genetic regulation, and production of anti-inflammatory mediators. Clinical trials evaluating a possible reduction in cardiovascular disease by n-3 PUFA have shown different results. Supplementation of vitamin D is common regarding prevention and treatment of osteoporosis. But vitamin D also seems to have several effects on the cardiovascular system. Vitamin D deficiency appears to be related to an increase in parathyroid hormone levels and can predispose to essential hypertension and left ventricular hypertrophy, increased insulin resistance, and eventually to atherosclerosis and adverse cardiovascular events. Randomized prospective clinical trials are needed to determine whether vitamin D and omega-3 FA supplementation therapy should be recommended as a routine therapy for primary or secondary prevention of cardiovascular disease
Experimental signatures of the mixed axial-gravitational anomaly in the Weyl semimetal NbP
Weyl semimetals are materials where electrons behave effectively as a kind of
massless relativistic particles known asWeyl fermions. These particles occur in
two flavours, or chiralities, and are subject to quantum anomalies, the
breaking of a conservation law by quantum fluctuations. For instance, the
number of Weyl fermions of each chirality is not independently conserved in
parallel electric and magnetic field, a phenomenon known as the chiral anomaly.
In addition, an underlying curved spacetime provides a distinct contribution to
a chiral imbalance, an effect known as the mixed axial-gravitational anomaly,
which remains experimentally elusive. However, the presence of a mixed
gauge-gravitational anomaly has recently been tied to thermoelectrical
transport in a magnetic field, even in flat spacetime, opening the door to
experimentally probe such type of anomalies in Weyl semimetals. Using a
temperature gradient, we experimentally observe a positive longitudinal
magnetothermoelectric conductance (PMTC) in the Weyl semimetal NbP for
collinear temperature gradients and magnetic fields (DT || B) that vanishes in
the ultra quantum limit. This observation is consistent with the presence of a
mixed axial-gravitational anomaly. Our work provides clear experimental
evidence for the existence of a mixed axial-gravitational anomaly of Weyl
fermions, an outstanding theoretical concept that has so far eluded
experimental detection
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