2,062 research outputs found
Pseudo-Jahn-Teller distortion of pyridine in its lowest triplet state
Biological and Soft Matter Physic
What and how advanced medical students learn from reasoning through multiple cases
The study reported in this article concerns the questions what and how fourth-year medical students can learn from a series of cases that have a similar underlying problem. This question is crucial in the theoretical sense as it looks at mechanisms of updating and improving knowledge structures, which are conjectured to consist of âillness scriptsâ, which integrate knowledge about enabling conditions for a disease, the underlying fault, and the consequences or signs and symptoms of the disease. It was found that much learning was implicit, whilst students explicitly paid attention to variations in enabling conditions and consequences, which led to improvement of these knowledge components. Integration of biomedical knowledge into the fault component was, however, hampered by lack of knowledge and by misconceptions that students were unable to debug in the absence of learning resources or detailed feedback. The practical importance of this study stems from its close parallels to the learning situation in clinical practice, where patients (or cases) are the most important learning resources, whilst feedback on results is often minimal. Implications and possible solutions for clinical teaching are discussed
BFKL Physics in Dijet Production at the LHC
The production in hadron-hadron collisions of jet pairs with large rapidity
separation and comparable modest transverse momentum is, in principle,
described by the perturbative QCD BFKL equation. The measurement of such jet
pairs appears well suited to the LHC detectors, with their ability to detect
forward jets. We present predictions for dijet cross sections and correlations
obtained using a BFKL Monte Carlo which allows kinematic and other subleading
effects to be incorporated. The enhanced phase space for gluon emission at the
LHC makes the BFKL behavior somewhat easier to observe than at the Tevatron,
although kinematic effects are still important. The production of forward jets
in association with heavy Higgs bosons via the gauge boson fusion mechanism is
also studied and compared with QCD dijet production.Comment: 13 pages including 5 figures, LaTeX, uses eps
Nuclear Resonance Vibrational Spectroscopy of Iron Sulfur Proteins
Nuclear inelastic scattering in conjunction with density functional theory
(DFT) calculations has been applied for the identification of vibrational modes
of the high-spin ferric and the high-spin ferrous iron-sulfur center of a
rubredoxin-type protein from the thermophylic bacterium Pyrococcus abysii
Spectral properties of the dimerized and frustrated chain
Spectral densities are calculated for the dimerized and frustrated S=1/2
chain using the method of continuous unitary transformations (CUTs). The
transformation to an effective triplon model is realized in a perturbative
fashion up to high orders about the limit of isolated dimers. An efficient
description in terms of triplons (elementary triplets) is possible: a detailed
analysis of the spectral densities is provided for strong and intermediate
dimerization including the influence of frustration. Precise predictions are
made for inelastic neutron scattering experiments probing the S=1 sector and
for optical experiments (Raman scattering, infrared absorption) probing the S=0
sector. Bound states and resonances influence the important continua strongly.
The comparison with the field theoretic results reveals that the sine-Gordon
model describes the low-energy features for strong to intermediate dimerization
only at critical frustration.Comment: 21 page
Evidence for a three-nucleon-force effect in proton-deuteron elastic scattering
Developments in spin-polarized internal targets for storage rings have
permitted measurements of 197 MeV polarized protons scattering from vector
polarized deuterons. This work presents measurements of the polarization
observables A_y, iT_11, and C_y,y in proton-deuteron elastic scattering. When
compared to calculations with and without three-nucleon forces, the
measurements indicate that three-nucleon forces make a significant contribution
to the observables. This work indicates that three-body forces derived from
static nuclear properties appear to be crucial to the description of dynamical
properties.Comment: 8 pages 2 figures Latex, submitted to Phys. Rev. Letter
Task-Oriented Conversational Behavior of Agents for Collaboration in Human-Agent Teamwork
International audienceCoordination is an essential ingredient for human-agent teamwork. It requires team members to share knowledge to establish common grounding and mutual awareness among them. This paper proposes a be-havioral architecture C 2 BDI that enhances the knowledge sharing using natural language communication between team members. Collaborative conversation protocols and resource allocation mechanism have been defined that provide proactive behavior to agents for coordination. This architecture has been applied to a real scenario in a collaborative virtual environment for learning. The solution enables users to coordinate with other team members
Oscillating magnetoresistance in diluted magnetic semiconductor barrier structures
Ballistic spin polarized transport through diluted magnetic semiconductor
(DMS) single and double barrier structures is investigated theoretically using
a two-component model. The tunneling magnetoresistance (TMR) of the system
exhibits oscillating behavior when the magnetic field are varied. An
interesting beat pattern in the TMR and spin polarization is found for
different NMS/DMS double barrier structures which arises from an interplay
between the spin-up and spin-down electron channels which are splitted by the
s-d exchange interaction.Comment: 4 pages, 6 figures, submitted to Phys. Rev.
- âŠ