4,303 research outputs found
From Task Classification Towards Similarity Measures for Recommendation in Crowdsourcing Systems
Task selection in micro-task markets can be supported by recommender systems
to help individuals to find appropriate tasks. Previous work showed that for
the selection process of a micro-task the semantic aspects, such as the
required action and the comprehensibility, are rated more important than
factual aspects, such as the payment or the required completion time. This work
gives a foundation to create such similarity measures. Therefore, we show that
an automatic classification based on task descriptions is possible.
Additionally, we propose similarity measures to cluster micro-tasks according
to semantic aspects.Comment: Work in Progress Paper at HCOMP 201
Jets plus Missing Energy with an Autofocus
Jets plus missing transverse energy is one of the main search channels for
new physics at the LHC. A major limitation lies in our understanding of QCD
backgrounds. Using jet merging we can describe the number of jets in typical
background channels in terms of a staircase scaling, including theory
uncertainties. The scaling parameter depends on the particles in the final
state and on cuts applied. Measuring the staircase scaling will allow us to
also predict the effective mass for Standard Model backgrounds. Based on both
observables we propose an analysis strategy avoiding model specific cuts which
returns information about the color charge and the mass scale of the underlying
new physics.Comment: 15 pages, 9 figures, 3 table
Establishing jet scaling patterns with a photon
Staircase and Poisson scaling are two typical patterns we observe for the exclusive number of jets at high energy hadron colliders. We examine these scaling properties for photon plus jets production at the LHC and find that this channel is well suited to study these features. We illustrate and discuss when to expect each of the two patterns, how to induce a transition through kinematic cuts, and how photons are related to heavy gauge bosons. Measurements of photon+jets production is therefore providing valuable information on exclusive jet scaling, which is going to help to eventually understand the theoretical origin of exclusive jet scaling properties in more detail
Minocycline is cytoprotective in human corneal endothelial cells and induces anti-apoptotic B-cell CLL/lymphoma 2 (Bcl-2) and X-linked inhibitor of apoptosis (XIAP)
Introduction Loss of corneal endothelial cells (CECs) is one major factor limiting transplant clarity and survival after keratoplasty. Amongst other factors, apoptosis due to cellular stress is responsible for these problems. This study investigates the possible anti-apoptotic and cytoprotective effects of minocycline on a human corneal endothelial cell line (HCEC-SV40) cultured under oxidative stress and with transforming growth factor beta (TGF-beta). Methods CECs were treated with 1-150 mM minocycline. Cell viability and the median inhibitory concentration (IC(50)) were evaluated after 48 h and after H(2)O(2) treatment (tetrazolium dye reduction assay and liveedead assay). Expression of B-cell CLL/lymphoma 2 (Bcl-2) and X-linked inhibitor of apoptosis (XIAP) and their mRNA were assessed by reverse transcriptase (RT)-PCR and western blot analysis after treatment with minocycline alone and consecutive incubation with 200 mM H(2)O(2) and TGF-beta 2. A quantitative detection of histone-associated DNA fragmentation by ELISA was performed. Results Minocycline concentrations from 1-50 mM showed no toxic effects on CECs. Pre-treatment with 10-40 mM minocycline led to an increase in viability after H(2)O(2) treatment. In addition, minocycline pretreatment attenuated the increase of histone-associated DNA fragmentation after treatment with H(2)O(2) and TGF-beta 2 significantly. When CECs were treated with minocycline and then consecutively with H(2)O(2) or TGF-beta 2, RT-PCR and western blot analysis yielded an overexpression of Bcl-2 and XIAP. Conclusion In this study minocycline prevented apoptotic cell death in cultured CECs in vitro. Our results suggest that minocycline might offer cytoprotective properties that might help to prevent loss of corneal endothelial cells in vivo
Protective capping of topological surface states of intrinsically insulating BiTe
We have identified epitaxially grown elemental Te as a capping material that
is suited to protect the topological surface states of intrinsically insulating
BiTe. By using angle-resolved photoemission, we were able to show that
the Te overlayer leaves the dispersive bands of the surface states intact and
that it does not alter the chemical potential of the BiTe thin film.
From in-situ four-point contact measurements, we observed that the conductivity
of the capped film is still mainly determined by the metallic surface states
and that the contribution of the capping layer is minor. Moreover, the Te
overlayer can be annealed away in vacuum to produce a clean BiTe
surface in its pristine state even after the exposure of the capped film to
air. Our findings will facilitate well-defined and reliable ex-situ experiments
on the properties of BiTe surface states with nontrivial topology.Comment: 5 pages, 5 figures, 2 pages supplemental material accepted for
publication in AIP Advance
Azimuthal correlations of pions in relativistic heavy ion collisions at 1 GeV/nucl.
Triple differential cross sections of pions in heavy ion collisions at 1 GeV/nucl. are studied with the IQMD model. After discussing general properties of resonance and pion production we focus on azimuthal correlations: At projectile- and target-rapidities we observe an anticorrelation in the in-plane transverse momentum between pions and protons. At c.m.-rapidity, however, we find that high pt pions are being preferentially emitted perpendicular to the event-plane. We investigate the causes of those correlations and their sensitivity on the density and momentum dependence of the real and imaginary part of the nucleon and pion optical potential
Out-of-plane pion emission in relativistic heavy ion collisions: Spectroscopy of Delta resonance matter
Azimuthal correlations of pions are studied with the quantum molecular dynamics model. Pions are preferentially emitted perpendicular to the reaction plane. Our analysis shows that this anisotropy is dominated by pion absorption on the spectator matter in the reaction plane. Pions emitted perpendicular to the reaction plane undergo less rescattering than those emitted in the reaction plane and might therefore be more sensitive to the early hot and dense reaction phase
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