60,610 research outputs found
Acoustic Kappa-Density Fluctuation Waves in Suprathermal Kappa Function Fluids
We describe a new wave mode similar to the acoustic wave in which both
density and velocity fluctuate. Unlike the acoustic wave in which the
underlying distribution is Maxwellian, this new wave mode occurs when the
underlying distribution is a suprathermal kappa function and involves
fluctuations in the power law index, kappa. This wave mode always propagates
faster than the acoustic wave with an equivalent effective temperature and
becomes the acoustic wave in the Maxwellian limit as kappa goes to infinity.Comment: 11 pages, 2 figures, in press AS
What's unusual in online disease outbreak news?
Background: Accurate and timely detection of public health events of
international concern is necessary to help support risk assessment and response
and save lives. Novel event-based methods that use the World Wide Web as a
signal source offer potential to extend health surveillance into areas where
traditional indicator networks are lacking. In this paper we address the issue
of systematically evaluating online health news to support automatic alerting
using daily disease-country counts text mined from real world data using
BioCaster. For 18 data sets produced by BioCaster, we compare 5 aberration
detection algorithms (EARS C2, C3, W2, F-statistic and EWMA) for performance
against expert moderated ProMED-mail postings. Results: We report sensitivity,
specificity, positive predictive value (PPV), negative predictive value (NPV),
mean alerts/100 days and F1, at 95% confidence interval (CI) for 287
ProMED-mail postings on 18 outbreaks across 14 countries over a 366 day period.
Results indicate that W2 had the best F1 with a slight benefit for day of week
effect over C2. In drill down analysis we indicate issues arising from the
granular choice of country-level modeling, sudden drops in reporting due to day
of week effects and reporting bias. Automatic alerting has been implemented in
BioCaster available from http://born.nii.ac.jp. Conclusions: Online health news
alerts have the potential to enhance manual analytical methods by increasing
throughput, timeliness and detection rates. Systematic evaluation of health
news aberrations is necessary to push forward our understanding of the complex
relationship between news report volumes and case numbers and to select the
best performing features and algorithms
Schizophrenia in older adults
Although the number of persons over the age of 55 with schizophrenia is expected to double over the next 20 years, the research data on older people with schizophrenia is limited. This appears to be because until the middle of the 20th century, it was assumed that mental illness in older people was a part of the aging process and older people are often excluded from research investigations. There is a need for nursing research to explore how people with schizophrenia, as they age, learn to manage their problems, as well as how those who are first diagnosed with schizophrenia in later life adapt to their illness. Mental health nurses need to be cautious in assigning premature labels to older adults with mental illness that may lead to unsubstantiated assumptions about levels of disability. Instead, they should realize individual potential regarding undiscovered strengths and should attempt to create interventions that recognize and foster personal development for older adults with schizophrenia
Towards cross-lingual alerting for bursty epidemic events
Background: Online news reports are increasingly becoming a source for event
based early warning systems that detect natural disasters. Harnessing the
massive volume of information available from multilingual newswire presents as
many challenges as opportunities due to the patterns of reporting complex
spatiotemporal events. Results: In this article we study the problem of
utilising correlated event reports across languages. We track the evolution of
16 disease outbreaks using 5 temporal aberration detection algorithms on
text-mined events classified according to disease and outbreak country. Using
ProMED reports as a silver standard, comparative analysis of news data for 13
languages over a 129 day trial period showed improved sensitivity, F1 and
timeliness across most models using cross-lingual events. We report a detailed
case study analysis for Cholera in Angola 2010 which highlights the challenges
faced in correlating news events with the silver standard. Conclusions: The
results show that automated health surveillance using multilingual text mining
has the potential to turn low value news into high value alerts if informed
choices are used to govern the selection of models and data sources. An
implementation of the C2 alerting algorithm using multilingual news is
available at the BioCaster portal http://born.nii.ac.jp/?page=globalroundup
Storage of Natural Language Sentences in a Hopfield Network
This paper look at how the Hopfield neural network can be used to store and
recall patterns constructed from natural language sentences. As a pattern
recognition and storage tool, the Hopfield neural network has received much
attention. This attention however has been mainly in the field of statistical
physics due to the model's simple abstraction of spin glass systems. A
discussion is made of the differences, shown as bias and correlation, between
natural language sentence patterns and the randomly generated ones used in
previous experiments. Results are given for numerical simulations which show
the auto-associative competence of the network when trained with natural
language patterns.Comment: latex, 10 pages with 2 tex figures and a .bib file, uses nemlap.sty,
to appear in Proceedings of NeMLaP-
A New California Oil Boom? Drilling the Monterey Shale
The Monterey Shale is a vast oil-bearing geologic formation stretching from Southern California almost as far north as San Francisco. The formation has largely been untapped due to its complexity and the challenges presented by the shale's unusual geology
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