45 research outputs found
The role of language skills in interactive social book search sessions
When searching for books, people frequently have to deal with content that is in a language different from their own. However, research on multilingual systems has generally focused on the user interface's language rather than the content language. In this paper, we describe and compare early results from the multilingual aspects in the Interactive Social Book Search (iSBS) task at CLEF 2014 and 2015. A preliminary analysis of usage patterns for native English and non-native English speakers indicates an influence of language skills on search behaviour during goal-oriented and casual leisure tasks. Based on previous experiences and results, strengths and challenges of IIR studies are discussed
Strength of the Spin-Fluctuation-Mediated Pairing Interaction in a High-Temperature Superconductor
Theories based on the coupling between spin fluctuations and fermionic
quasiparticles are among the leading contenders to explain the origin of
high-temperature superconductivity, but estimates of the strength of this
interaction differ widely. Here we analyze the charge- and spin-excitation
spectra determined by angle-resolved photoemission and inelastic neutron
scattering, respectively, on the same crystals of the high-temperature
superconductor YBa2Cu3O6.6. We show that a self-consistent description of both
spectra can be obtained by adjusting a single parameter, the spin-fermion
coupling constant. In particular, we find a quantitative link between two
spectral features that have been established as universal for the cuprates,
namely high-energy spin excitations and "kinks" in the fermionic band
dispersions along the nodal direction. The superconducting transition
temperature computed with this coupling constant exceeds 150 K, demonstrating
that spin fluctuations have sufficient strength to mediate high-temperature
superconductivity.Comment: 25 pages, 7 figures, including supplementary information, accepted
for publication in Nature Physic
Energy gaps in the failed high-Tc superconductor La1.875Ba0.125CuO4
A central issue on high-Tc superconductivity is the nature of the
normal-state gap (pseudogap) in the underdoped regime and its relationship with
superconductivity. Despite persistent efforts, theoretical ideas for the
pseudogap evolve around fluctuating superconductivity, competing order and
spectral weight suppression due to many-body effects. Recently, while some
experiments in the superconducting state indicate a distinction between the
superconducting gap and pseudogap, others in the normal state, either by
extrapolation from high-temperature data or directly from La1.875Ba0.125CuO4
(LBCO-1/8) at low temperature, suggest the ground-state pseudogap is a single
gap of d-wave form. Here we report angle-resolved photoemission (ARPES) data
from LBCO-1/8, collected with improved experimental conditions, that reveal the
ground-state pseudogap has a pronounced deviation from the simple d-wave form.
It contains two distinct components: a d-wave component within an extended
region around the node and the other abruptly enhanced close to the antinode,
pointing to a dual nature of the pseudogap in this failed high-Tc
superconductor which involves a possible precursor pairing energy scale around
the node and another of different but unknown origin near the antinode.Comment: Nature Physics advance online publication, Dec. 21st 2008; Author's
original version of the main text; for a better resolution of figures &
Supplementary Information, visit Nature Physics' websit
Predictors of death after Clostridium difficile infection: a report on 128 strain-typed cases from a teaching hospital in the United Kingdom
We assessed the relationship between strain type, clinical factors, and outcome in 128 patients with Clostridium difficile infection. Strain type was not associated with any outcome measure. On multivariate analysis, ischemic heart disease and hypoalbuminemia predicted death. Metronidazole treatment in severe disease was associated with a higher rate of treatment failure and death