1,735 research outputs found
Beyond the single-atom response in absorption lineshapes: Probing a dense, laser-dressed helium gas with attosecond pulse trains
We investigate the absorption line shapes of laser-dressed atoms beyond the
single-atom response, by using extreme ultraviolet (XUV) attosecond pulse
trains to probe an optically thick helium target under the influence of a
strong infrared (IR) field. We study the interplay between the IR-induced phase
shift of the microscopic time-dependent dipole moment and the
resonant-propagation-induced reshaping of the macroscopic XUV pulse. Our
experimental and theoretical results show that as the optical depth increases,
this interplay leads initially to a broadening of the IR-modified line shape,
and subsequently to the appearance of new, narrow features in the absorption
line.Comment: 5 pages, 5 figure
Genetic polymorphisms: Impact on the risk of fetal alcohol spectrum disorders
Clinical reports on monozygotic and dizygotic twins provided the initial evidence for the involvement of genetic factors in risk vulnerability for fetal alcohol spectrum disorders (FASD) including fetal alcohol syndrome (FAS). Research with selectively bred and inbred rodents, genetic crosses of these lines and strains, and embryo culture studies have further clarified the role of both maternal and fetal genetics in the development of FASD. Research to identify specific polymorphisms contributing to FASD is still at an early stage. To date, polymorphisms of only one of the genes for the alcohol dehydrogenase enzyme family, the ADH1B, have been demonstrated to contribute to FASD vulnerability. In comparison with ADH1B*1, both maternal and fetal ADH1B*2 have been shown to reduce risk for FAS in a mixed ancestry South African population. ADH1B*3 appears to afford protection for FASD outcomes in African-American populations. Other candidate genes should be examined with respect to FASD risk, including those for the enzymes of serotonin metabolism, in particular the serotonin transporter. By its very nature, alcohol teratogenesis is the expression of the interaction of genes with environment. The study of genetic factors in FASD falls within the new field of ecogenetics. Understanding of the array of genetic factors in FASD will be enhanced by future genetic investigations, including case-control, family association, and linkage studies. Birth Defects Research (Part A), 2005
Project RISE: Recognizing Industrial Smoke Emissions
Industrial smoke emissions pose a significant concern to human health. Prior
works have shown that using Computer Vision (CV) techniques to identify smoke
as visual evidence can influence the attitude of regulators and empower
citizens to pursue environmental justice. However, existing datasets are not of
sufficient quality nor quantity to train the robust CV models needed to support
air quality advocacy. We introduce RISE, the first large-scale video dataset
for Recognizing Industrial Smoke Emissions. We adopted a citizen science
approach to collaborate with local community members to annotate whether a
video clip has smoke emissions. Our dataset contains 12,567 clips from 19
distinct views from cameras that monitored three industrial facilities. These
daytime clips span 30 days over two years, including all four seasons. We ran
experiments using deep neural networks to establish a strong performance
baseline and reveal smoke recognition challenges. Our survey study discussed
community feedback, and our data analysis displayed opportunities for
integrating citizen scientists and crowd workers into the application of
Artificial Intelligence for social good.Comment: Technical repor
Evorus: A Crowd-powered Conversational Assistant Built to Automate Itself Over Time
Crowd-powered conversational assistants have been shown to be more robust
than automated systems, but do so at the cost of higher response latency and
monetary costs. A promising direction is to combine the two approaches for high
quality, low latency, and low cost solutions. In this paper, we introduce
Evorus, a crowd-powered conversational assistant built to automate itself over
time by (i) allowing new chatbots to be easily integrated to automate more
scenarios, (ii) reusing prior crowd answers, and (iii) learning to
automatically approve response candidates. Our 5-month-long deployment with 80
participants and 281 conversations shows that Evorus can automate itself
without compromising conversation quality. Crowd-AI architectures have long
been proposed as a way to reduce cost and latency for crowd-powered systems;
Evorus demonstrates how automation can be introduced successfully in a deployed
system. Its architecture allows future researchers to make further innovation
on the underlying automated components in the context of a deployed open domain
dialog system.Comment: 10 pages. To appear in the Proceedings of the Conference on Human
Factors in Computing Systems 2018 (CHI'18
Smart Conversational Agents for Reminiscence
In this paper we describe the requirements and early system design for a
smart conversational agent that can assist older adults in the reminiscence
process. The practice of reminiscence has well documented benefits for the
mental, social and emotional well-being of older adults. However, the
technology support, valuable in many different ways, is still limited in terms
of need of co-located human presence, data collection capabilities, and ability
to support sustained engagement, thus missing key opportunities to improve care
practices, facilitate social interactions, and bring the reminiscence practice
closer to those with less opportunities to engage in co-located sessions with a
(trained) companion. We discuss conversational agents and cognitive services as
the platform for building the next generation of reminiscence applications, and
introduce the concept application of a smart reminiscence agent
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