2,003 research outputs found
Quiet as a Church Rat
Quiet as a Church Rat is about a naïve teenager who attempts to steal money from his grandma’s purse to buy a video game. This teenager wants to live dangerously like a “rat” but in the process of stealing money from his grandma, he finds out that the “rat” life isn’t for him
Evaluating Competing Agent Strategies for a Voice Email Agent
This paper reports experimental results comparing a mixed-initiative to a
system-initiative dialog strategy in the context of a personal voice email
agent. To independently test the effects of dialog strategy and user expertise,
users interact with either the system-initiative or the mixed-initiative agent
to perform three successive tasks which are identical for both agents. We
report performance comparisons across agent strategies as well as over tasks.
This evaluation utilizes and tests the PARADISE evaluation framework, and
discusses the performance function derivable from the experimental data.Comment: 6 pages latex, uses icassp91.sty, psfi
Epidemiology and burden of nasal congestion
Nasal congestion, which may be described as fullness, obstruction, reduced airflow, or being "stuffed up," is a commonly encountered symptom in clinical practice. Systematic study of congestion has largely considered it as a component of a disease state. Conditions associated with congestion include nasal polyposis, obstructive sleep apnea, and anatomic variation; however, most information on the burden of congestion comes from studies of allergic rhinitis and rhinosinusitis, diseases of which congestion is the major symptom. Congestion can be caused by other rhinologic conditions, such as non-allergic rhinitis, viral or bacterial rhinitis, and vasomotor rhinitis. Allergic rhinitis affects as much as one quarter of the population worldwide and imposes a significant economic burden. Additionally, allergic rhinitis significantly impairs quality of life; congestion causes allergic rhinitis sufferers decreased daytime productivity at work or school and reduces night-time sleep time and quality. Annually, rhinosinusitis affects tens of millions of Americans and leads to approximately $6 billion in overall health care expenditures; it has been found to be one of the most costly physical conditions for US employers. Given the high prevalence and significant social and economic burden of nasal congestion, this symptom should be a key consideration in treating patients with rhinologic disease, and there continues to be a significant unmet medical need for effective treatment options for this condition. © 2010 Stewart et al
Nonlinear Optical studies of the Transient Coherence in the Quantum Hall System
We review recent investigations of the femtosecond non-linear optical
response of the two-dimensional electron gas (2DEG) in a strong magnetic field.
We probe the Quantum Hall (QH) regime for filling factors . Our
focus is on the transient coherence induced via optical excitation and on its
time evolution during early femtosecond timescales. We simultaneously study the
interband and intraband coherence in this system by using a nonlinear
spectroscopic technique, transient three-pulse four wave mixing optical
spectroscopy, and a many-body theory. We observe striking differences in the
temporal and spectral profile of the nonlinear optical signal between a
modulation doped quantum well system (with the 2DEG) and a similar undoped
quantum well (without a 2DEG). We attribute these qualitative differences to
Coulomb correlations between the photoexcited electron-hole pairs and the 2DEG.
We show, in particular, that intraband many-particle coherences assisted by the
inter-Landau-level magnetoplasmon excitations of the 2DEG dominate the
femtosecond nonlinear optical responce. The most striking effect of these
exciton-magnetoplasmon coherences is a large off-resonant four-wave-mixing
signal in the case of very low photoexcited carrier densities, not observed in
the undoped system, with strong temporal oscillations and unusually symmetric
temporal profile.Comment: 22 pages, 9 figures; review article to be published in Solid State
Communication
Is there a rationale and role for long-acting anticholinergic bronchodilators in asthma?
The authors acknowledge the medical writing assistance received from Sam Yarwood, PhD, of Complete HealthVizion, in the form of literature searches and preparation and revision of the draft manuscript.Peer reviewedPublisher PD
Défibrillateur automatique implantable (DAI): principes de base et indications cliniques actuelles [Implantable cardiac defibrillator (ICD): basics and present clinical guidelines].
An implantable cardiac defibrillator (ICD) is a cardiac implantable electronic device that is capable of identifying and treating ventricular arrhythmias. Consideration about the type of ICD to select for a given patient include whether the patient has bradycardia requiring pacing support, has associated atrial tachyarrhythmias, or would benefit from cardiac resynchronization therapy. The ICD functions by continuously monitoring the patient's cardiac rate and delivering therapies (anti-tachycardia pacing, shocks) when the rate exceeds the programmed rate "cutoff". Secondary prevention trials have demonstrated that ICDs reduce the incidence of arrhythmic death and total mortality in patients presenting with a cardiac arrest. ICDs are also indicated for primary prevention of sudden cardiac death in specific high-risk subgroups of patients
Strong Electronic Correlation Effects in Coherent Multidimensional Nonlinear Optical Spectroscopy
We discuss a many−body theory of the coherent ultrafast nonlinear optical response of systems with a strongly correlated electronic ground state that responds unadiabatically to photoexcitation. We introduce a truncation of quantum kinetic density matrix equations of motion that does not rely on an expansion in terms of the interactions and thus applies to strongly correlated systems. For this we expand in terms of the optical field, separate out contributions to the time−evolved many−body state due to correlated and uncorrelated multiple optical transitions, and use “Hubbard operator” density matrices to describe the exact dynamics of the individual contributions within a subspace of strongly coupled states, including “pure dephasing”. Our purpose is to develop a quantum mechanical tool capable of exploring how, by coherently photoexciting selected modes, one can trigger nonlinear dynamics of strongly coupled degrees of freedom. Such dynamics could lead to photoinduced phase transitions. We apply our theory to the nonlinear response of a two−dimensional electron gas (2DEG) in a magnetic field. We coherently photoexcite the two lowest Landau level (LL) excitations using three time−delayed optical pulses. We identify some striking temporal and spectral features due to dynamical coupling of the two LLs facilitated by inter−Landau−level magnetoplasmon and magnetoroton excitations and compare to three−pulse four−wave−mixing (FWM) experiments. We show that these features depend sensitively on the dynamics of four−particle correlations between an electron−hole pair and a magnetoplasmon/magnetoroton, reminiscent of exciton−exciton correlations in undoped semiconductors. Our results shed light into unexplored coherent dynamics and relaxation of the quantum Hall system (QHS) and can provide new insight into non−equilibrium co−operative phenomena in strongly correlated systems
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