91 research outputs found
A sufficient criterion for integrability of stochastic many-body dynamics and quantum spin chains
We propose a dynamical matrix product ansatz describing the stochastic
dynamics of two species of particles with excluded-volume interaction and the
quantum mechanics of the associated quantum spin chains respectively. Analyzing
consistency of the time-dependent algebra which is obtained from the action of
the corresponding Markov generator, we obtain sufficient conditions on the
hopping rates for identifing the integrable models. From the dynamical algebra
we construct the quadratic algebra of Zamolodchikov type, associativity of
which is a Yang Baxter equation. The Bethe ansatz equations for the spectra are
obtained directly from the dynamical matrix product ansatz.Comment: 19 pages Late
Educational effects of early or later secondary school tracking in Germany
This paper examines educational outcomes of pupils selected to secondary school types by different tracking regimes in a German state: Pupils are alternatively streamed after fourth grade or after sixth grade. Regression results indicate that, estimated on the mean, there are no negative effects of later tracking on educational outcomes in the middle of secondary school. Positive effects are observed for pupils with a less favorable family background. Quantile regressions reveal that the estimated effects of later tracking are positive for the lower quantiles but decrease monotonically over the conditional distribution of test scores
Impact of clinical phenotypes on management and outcomes in European atrial fibrillation patients: a report from the ESC-EHRA EURObservational Research Programme in AF (EORP-AF) General Long-Term Registry
Background: Epidemiological studies in atrial fibrillation (AF) illustrate that clinical complexity increase the risk of major adverse outcomes. We aimed to describe European AF patients\u2019 clinical phenotypes and analyse the differential clinical course. Methods: We performed a hierarchical cluster analysis based on Ward\u2019s Method and Squared Euclidean Distance using 22 clinical binary variables, identifying the optimal number of clusters. We investigated differences in clinical management, use of healthcare resources and outcomes in a cohort of European AF patients from a Europe-wide observational registry. Results: A total of 9363 were available for this analysis. We identified three clusters: Cluster 1 (n = 3634; 38.8%) characterized by older patients and prevalent non-cardiac comorbidities; Cluster 2 (n = 2774; 29.6%) characterized by younger patients with low prevalence of comorbidities; Cluster 3 (n = 2955;31.6%) characterized by patients\u2019 prevalent cardiovascular risk factors/comorbidities. Over a mean follow-up of 22.5 months, Cluster 3 had the highest rate of cardiovascular events, all-cause death, and the composite outcome (combining the previous two) compared to Cluster 1 and Cluster 2 (all P <.001). An adjusted Cox regression showed that compared to Cluster 2, Cluster 3 (hazard ratio (HR) 2.87, 95% confidence interval (CI) 2.27\u20133.62; HR 3.42, 95%CI 2.72\u20134.31; HR 2.79, 95%CI 2.32\u20133.35), and Cluster 1 (HR 1.88, 95%CI 1.48\u20132.38; HR 2.50, 95%CI 1.98\u20133.15; HR 2.09, 95%CI 1.74\u20132.51) reported a higher risk for the three outcomes respectively. Conclusions: In European AF patients, three main clusters were identified, differentiated by differential presence of comorbidities. Both non-cardiac and cardiac comorbidities clusters were found to be associated with an increased risk of major adverse outcomes
Critical phenomena and universal dynamics in one-dimensional driven diffusive systems with two species of particles
Recent work on stochastic interacting particle systems with two particle
species (or single-species systems with kinematic constraints) has demonstrated
the existence of spontaneous symmetry breaking, long-range order and phase
coexistence in nonequilibrium steady states, even if translational invariance
is not broken by defects or open boundaries. If both particle species are
conserved, the temporal behaviour is largely unexplored, but first results of
current work on the transition from the microscopic to the macroscopic scale
yield exact coupled nonlinear hydrodynamic equations and indicate the emergence
of novel types of shock waves which are collective excitations stabilized by
the flow of microscopic fluctuations. We review the basic stationary and
dynamic properties of these systems, highlighting the role of conservation laws
and kinetic constraints for the hydrodynamic behaviour, the microscopic origin
of domain wall (shock) stability and the coarsening dynamics of domains during
phase separation.Comment: 72 pages, 6 figures, 201 references (topical review for J. Phys. A:
Math. Gen.
Institutions as Knowledge Capital: Ludwig M' Lachmann's Interpretative Institutionalism
Search for scalar diphoton resonances in the mass range 65-600 GeV with the ATLAS detector in pp collision data at √s = 8 TeV
A search for scalar particles decaying via narrow resonances into two photons in the mass range 65–600 GeV is performed using 20.3 fb−¹ of √s=8 TeV pp collision data collected with the ATLAS detector at the Large Hadron Collider. The recently discovered Higgs boson is treated as a background. No significant evidence for an additional signal is observed. The results are presented as limits at the 95% confidence level on the production cross section of a scalar boson times branching ratio into two photons, in a fiducial volume where the reconstruction efficiency is approximately independent of the event topology. The upper limits set extend over a considerably wider mass range than previous searches
Dem werthesten Andenken des weiland Hochgebohrnen Herrn Herrn Carl Ludewig Des H.R.R. Grafen von Giech Herrn zu Thurnau, Buchau [et]c. [et]c. welcher den 11. Jenner 1752. in der hofnungsreichen Blüthe seines Alters zu Braunschweig durch einen seligen Tod das Zeitliche mit dem Ewigen verwechselte wiedmeten diese wehmüthigen Klagen Drey Seiner aufrichtigsten Freunde St--tz. B--e. Sch--tz
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