142 research outputs found
Conspiratorial thinking and foreign policy views: evidence from Central Europe
This is the final version. Available on open access from Taylor & Francis via the DOI in this recordForeign policy analysts assume that conspiratorial thinking is linked to citizensâ foreign policy
views and in particular to a preference among citizens for an alignment with Russia rather than
the West. Empirical studies on the relationship between conspiratorial thinking and citizensâ
foreign policy views are, however, lacking, despite a growing general academic interest in its
origins and consequences . Our analysis breaks new ground by empirically evaluating the
relationship between conspiratorial thinking and foreign policy preferences based on ISSP
survey data for Slovakia. We find that conspiratorial thinking decreases the extent to which
citizens prefer their country to be aligned with the West. The effect of conspiratorial thinking is
substantively meaningful and on par with other predictors of foreign policy views
Observation of secondary instability of 2/1 magnetic island in compass high density limit plasmas
Density limit disruptions (DLDs) have been observed in tokamak plasmas when high density regimes are explored. The DLDs are harmless in small size tokamaks like COMPASS,larger tokamaks like JET try to avoid them and they are extremely undesirable in ITER sizetokamaks due to the severe structural damages they can cause. It is very important to understand the dynamics of the DLDs so that better strategies to ameliorate or avoid them can bedeveloped. In this work, following detection in JET [1] of a secondary instability (SI) to thewell-known m/n = 2/1 MHD mode (where m and n are the poloidal and toroidal mode numbers, respectively) in the precursor of DLD, we analyse the evolution of the 2/1 magnetic islandin COMPASS DLD to look for the presence of this SI just close to the onset of energy quenchphase of the disruption. The presence of this SI to the magnetic island was associated with theoccurrence of minor disruptions preceding the major disruption and with the major disruptionitself in [1]. The coherence observed between the perturbations caused by the SI in the magneticpoloidal flux and in the electron temperature was very high (above 0.9), allowing to determinethat the SI perturbations came from the same position as the magnetic island. In the work presented here, only the perturbations in the magnetic poloidal flux are analysed since at the time ofthe experiments in COMPASS, no diagnostics was operational for measuring the time evolutionof the electron temperature with high time rate.Nonlinear MHD numerical simulations have also shown that island deformation during itsrapid growth can lead to the secondary magnetic island formation [2]. A recent review [3] ofthe theory of current sheet formation that leads to magnetic reconnection discusses the role ofplasmoids during magnetic island evolution. Since the validity ranges of the mentioned theoretical works are not directly comparable to the experimental conditions, one cannot claimwith certainty that the SI observed in JET [1] and in COMPASS disruptions (reported here)are the same as observed in those numerical works [2, 3]. However, there are some qualitative43rd EPS Conference on Plasma Physics P5.003similarities between them.The main COMPASS [4] diagnostics used for the analysis in the present work, are the threetoroidally separated arrays (A at 32.5âŠ, B at 212.5âŠand C at 257.5âŠfrom the vessel axis) ofMirnov coils (MCs), each with 24 MCs located poloidally. The MC arrays A and C, toroidallyseparated by 135âŠ, measure the change in poloidal magnetic flux, dBp/dt. The MC array B,toroidally separated by 180âŠto the array A, measures the poloidal magnetic field, Bp. Thesemagnetic sensors have good responsivity to high frequency (up to 1 MHz)
Dark septate endophytes and arbuscular mycorrhizal fungi (Parisâmorphotype) affect the stable isotope composition of 'classically' non-mycorrhizal plants
The vast majority of terrestrial plants exchange nutrients with fungal partners forming different mycorrhizal types. The minority of plants considered as non-mycorrhizal, however, are not necessarily free of any fungi, but are frequently colonized by elusive fungal endophytes, such as dark septate endophytes (DSE) or fine root endophytes (FRE). While a functional role of FRE in improvement of nutrient gain was recently elucidated, the function of DSE is still in discussion and was here addressed for 36 plant species belonging to the families Equisetaceae, Cypereaceae and Caryophyllaceae.
Molecular and microscopic staining approaches were conducted to verify the presence of DSE in the investigated species. Stable isotope natural abundances of the elements carbon, nitrogen, hydrogen and oxygen and total nitrogen concentrations were analyzed for the respective species of the target plant families and accompanying mycorrhizal and non-mycorrhizal (Brassicaceae) plant species.
Staining approaches confirmed the presence of DSE in all investigated species within the families Equisetaceae, Cyperaceae and Caryophyllaceae. A co-colonization with Paris-type arbuscular mycorrhiza (AM) was occasionally found by staining and molecular approaches in species of the Equisetaceae. Species of the Equisetaceae, Cyperaceae and Caryophyllaceae were significantly 15N-enriched in comparison to accompanying plants. In addition, a significant 13C and 2H enrichment and increased total nitrogen concentrations were found for representatives of the Equisetaceae.
The 15N-enrichment found here for representatives of Equisetaceae, Cyperaceae and Caryophyllaceae provides evidence for a functional role of the ubiquitous DSE fungi. DSE fungi obviously provide access to 15N-enriched soil organic compounds probably in exchange for organic carbon compounds from plant photosynthesis. As indicated by additional 13C- and 2H-enrichments, representatives of the Equisetaceae apparently gain simultaneously organic carbon compounds from their AM fungi of the Paris-morphotype. Thus, species of the Equisetaceae have to be considered as partially, or in case of the achlorophyllous fertile Equisetum arvense, as fully mycoheterotrophic at least in some stages of their life cycle.
So far mostly underappreciated fungi classified as DSE are suggested to occupy an ecologically relevant role similar to mycorrhizae and the occurrence of simultaneous functions of DSE and AM fungi in Equisetaceae is proposed
Progress of the Felsenkeller shallow-underground accelerator for nuclear astrophysics
Low-background experiments with stable ion beams are an important tool for
putting the model of stellar hydrogen, helium, and carbon burning on a solid
experimental foundation. The pioneering work in this regard has been done by
the LUNA collaboration at Gran Sasso, using a 0.4 MV accelerator. In the
present contribution, the status of the project for a higher-energy underground
accelerator is reviewed. Two tunnels of the Felsenkeller underground site in
Dresden, Germany, are currently being refurbished for the installation of a 5
MV high-current Pelletron accelerator. Construction work is on schedule and
expected to complete in August 2017. The accelerator will provide intense, 50
uA, beams of 1H+, 4He+, and 12C+ ions, enabling research on astrophysically
relevant nuclear reactions with unprecedented sensitivity.Comment: Submitted to the Proceedings of Nuclei in the Cosmos XIV, 19-24 June
2016, Niigata/Japa
Demonstrating Advantages of Neuromorphic Computation: A Pilot Study
Neuromorphic devices represent an attempt to mimic aspects of the brain's
architecture and dynamics with the aim of replicating its hallmark functional
capabilities in terms of computational power, robust learning and energy
efficiency. We employ a single-chip prototype of the BrainScaleS 2 neuromorphic
system to implement a proof-of-concept demonstration of reward-modulated
spike-timing-dependent plasticity in a spiking network that learns to play the
Pong video game by smooth pursuit. This system combines an electronic
mixed-signal substrate for emulating neuron and synapse dynamics with an
embedded digital processor for on-chip learning, which in this work also serves
to simulate the virtual environment and learning agent. The analog emulation of
neuronal membrane dynamics enables a 1000-fold acceleration with respect to
biological real-time, with the entire chip operating on a power budget of 57mW.
Compared to an equivalent simulation using state-of-the-art software, the
on-chip emulation is at least one order of magnitude faster and three orders of
magnitude more energy-efficient. We demonstrate how on-chip learning can
mitigate the effects of fixed-pattern noise, which is unavoidable in analog
substrates, while making use of temporal variability for action exploration.
Learning compensates imperfections of the physical substrate, as manifested in
neuronal parameter variability, by adapting synaptic weights to match
respective excitability of individual neurons.Comment: Added measurements with noise in NEST simulation, add notice about
journal publication. Frontiers in Neuromorphic Engineering (2019
How metaphysical commitments shape the study of psychological mechanisms
The study of psychological mechanisms is an interdisciplinary endeavour, requiring insights from many different domains (from electrophysiology, to psychology, to theoretical neuroscience, to computer science). In this article, I argue that philosophy plays an essential role in this interdisciplinary project, and that effective scientific study of psychological mechanisms requires that working scientists be responsible metaphysicians. This means adopting deliberate metaphysical positions when studying mechanisms that go beyond what is empirically justified regarding the nature of the phenomenon being studied, the conditions of its occurrence, and its boundaries. Such metaphysical commitments are necessary in order to set up experimental protocols, determine which variables to manipulate under experimental conditions, and which conclusions to draw from different scientific models and theories. It is important for scientists to be aware of the metaphysical commitments they adopt, since they can easily be led astray if invoked carelessly
Versatile emulation of spiking neural networks on an accelerated neuromorphic substrate
We present first experimental results on the novel BrainScaleS-2 neuromorphic
architecture based on an analog neuro-synaptic core and augmented by embedded
microprocessors for complex plasticity and experiment control. The high
acceleration factor of 1000 compared to biological dynamics enables the
execution of computationally expensive tasks, by allowing the fast emulation of
long-duration experiments or rapid iteration over many consecutive trials. The
flexibility of our architecture is demonstrated in a suite of five distinct
experiments, which emphasize different aspects of the BrainScaleS-2 system
In vivo biomolecular imaging of zebrafish embryos using confocal Raman spectroscopy
Zebrafish embryos provide a unique opportunity to visualize complex biological processes, yet conventional imaging modalities are unable to access intricate biomolecular information without compromising the integrity of the embryos. Here, we report the use of confocal Raman spectroscopic imaging for the visualization and multivariate analysis of biomolecular information extracted from unlabeled zebrafish embryos. We outline broad applications of this method in: (i) visualizing the biomolecular distribution of whole embryos in three dimensions, (ii) resolving anatomical features at subcellular spatial resolution, (iii) biomolecular profiling and discrimination of wild type and ÎRD1 mutant Mycobacterium marinum strains in a zebrafish embryo model of tuberculosis and (iv) in vivo temporal monitoring of the wound response in living zebrafish embryos. Overall, this study demonstrates the application of confocal Raman spectroscopic imaging for the comparative bimolecular analysis of fully intact and living zebrafish embryos
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