336 research outputs found
Artificial Intelligence Approach to the Determination of Physical Properties of Eclipsing Binaries. I. The EBAI Project
Achieving maximum scientific results from the overwhelming volume of
astronomical data to be acquired over the next few decades will demand novel,
fully automatic methods of data analysis. Artificial intelligence approaches
hold great promise in contributing to this goal. Here we apply neural network
learning technology to the specific domain of eclipsing binary (EB) stars, of
which only some hundreds have been rigorously analyzed, but whose numbers will
reach millions in a decade. Well-analyzed EBs are a prime source of
astrophysical information whose growth rate is at present limited by the need
for human interaction with each EB data-set, principally in determining a
starting solution for subsequent rigorous analysis. We describe the artificial
neural network (ANN) approach which is able to surmount this human bottleneck
and permit EB-based astrophysical information to keep pace with future data
rates. The ANN, following training on a sample of 33,235 model light curves,
outputs a set of approximate model parameters (T2/T1, (R1+R2)/a, e sin(omega),
e cos(omega), and sin i) for each input light curve data-set. The whole sample
is processed in just a few seconds on a single 2GHz CPU. The obtained
parameters can then be readily passed to sophisticated modeling engines. We
also describe a novel method polyfit for pre-processing observational light
curves before inputting their data to the ANN and present the results and
analysis of testing the approach on synthetic data and on real data including
fifty binaries from the Catalog and Atlas of Eclipsing Binaries (CALEB)
database and 2580 light curves from OGLE survey data. [abridged]Comment: 52 pages, accepted to Ap
What Matters to Americans: Social, Political and Economic Values
Societies are complex entities with competing and conflicting and supporting
and reinforcing characteristics. This study, part of a multiyear project
sponsored by the Australian Research Council (ARC) in conjunction with the
University of Technology, Sydney and Melbourne Business School, seeks to
chart the social, economic and political preferences of society, using a unique
methodology that provides us with a more accurate and robust picture of how
individuals, as citizens, make fundamental trade-offs about things of material
interest to their society.
The study was conducted in the United States of America with more than
2,800 participants, chosen to match the profile of the voting age population.
Similar studies were conducted in the UK, Australia and Germany, providing
data on more than 9,000 individuals.1 Examined were 16 categories of
general social, economic and political issues that ranged from the local (for
example, crime and public safety) to the global (for example, global security)
along with 113 sub-issues that also varied from the local (for example, public
transport and children’s schooling) to the global (for example, nuclear nonproliferation
and third world debt). This information was linked to data on the
population’s religious and political activities, its general demographics, and
donating and volunteering activities with civil society organizations
What Matters to Australians: Our Social, Political and Economic Values
Societies are complex entities with competing and conflicting and supporting
and reinforcing characteristics. This study, part of a multiyear project
sponsored by the Australian Research Council (ARC) in conjunction with the
University of Technology, Sydney and Melbourne Business School, seeks to
chart the social, economic and political preferences of our society using a
unique methodology that provides us with a more accurate and robust picture
of how we, as citizens, make fundamental trade-offs about things of material
interest to our society.
The study was conducted in Australia with more than 1,500 participants
chosen to match the profile of the voting age population. Similar studies were
conducted in the UK, USA and Germany. Examined were 16 categories of
general social, economic and political issues that ranged from the local (e.g.,
crime & public safety) to the global (e.g., global security) along with 113 subissues
that also varied from the local (e.g., public transport and children’s
schooling) to the global (e.g., nuclear non-proliferation and third world debt).
This information was linked to information on the population’s religious and
political activities, its general demographics, and donating and volunteering
activities with civil society organisations
What Matters to Citizens of the United Kingdom: Social, Political and Economic Values
Societies are complex entities with competing and conflicting and supporting
and reinforcing characteristics. This study, part of a multiyear project
sponsored by the Australian Research Council (ARC) in conjunction with the
University of Technology, Sydney and Melbourne Business School, seeks to
chart the social, economic and political preferences of society using a unique
methodology that provides us with a more accurate and robust picture of how
individuals, as citizens, make fundamental trade-offs about things of material
interest to their society.
The study was conducted in the United Kingdom with nearly 1,700
participants, chosen to match the profile of the voting age population. Similar
studies were conducted in Australia, the USA and Germany. Examined were
16 categories of general social, economic and political issues that ranged
from the local (for example, crime and public safety) to the global (for
example, global security) along with 113 sub-issues that also varied from the
local (for example, public transport and children’s schooling) to the global (for
example, nuclear non-proliferation and third world debt). This information was
linked to data on the population’s religious and political activities, its general
demographics, and donating and volunteering activities with civil society
organisations
Global molecular epidemiology of IMP-producing Enterobacteriaceae
International data on the molecular epidemiology of Enterobacteriaceae with IMP
carbapenemases are lacking. We performed short read (Illumina) whole genomic sequencing
on a global collection of 38 IMP-producing clinical Enterobacteriaceae (2008-14).
IMP-producing Enterobacteriaceae (7 varieties within 11 class 1 integrons) were mainly
present in South Pacific and Asia. Specific blaIMP containing integrons (In809 with blaIMP-4,
In722 with blaIMP-6, In687 with blaIMP-14) were circulating among different bacteria in
countries such as Australia, Japan and Thailand. In1312 with blaIMP-1 was present in K.
pneumoniae from Japan and C. freundii from Brazil. Klebsiella pneumoniae (n=22) was the
most common species; clonal complex (CC) 14 from the Philippines and Japan was the most
common clone and contained In1310 with blaIMP-26 and In1321 with blaIMP-6. Enterobacter
cloacae complex (n=9) consisted of E. hormaechei and E. cloacae cluster III. CC78 (from
Taiwan) containing In73 with blaIMP-8, was the most common clone among E. cloacae
complex. This study highlights the importance of surveillance programs using the latest
molecular techniques in providing insight into the characteristics and global distribution of
Enterobacteriaceae with blaIMPs.This work was supported by the John Mung Program from Kyoto University, Japan (Y.M.),
a research grant from the Calgary Laboratory Services (#10015169; J.D.D.P) and federal
funds from the National Institute of Allergy and Infectious Diseases, National Institutes of
Health, Department of Health and Human Services under Award Number U19AI110819
(MDA).http://aac.asm.org2017-10-30hb2017Medical Microbiolog
Ecto-5′-nucleotidase and intestinal ion secretion by enteropathogenic Escherichia coli
Enteropathogenic Escherichia coli (EPEC) triggers a large release of adenosine triphosphate (ATP) from host intestinal cells and the extracellular ATP is broken down to adenosine diphosphate (ADP), AMP, and adenosine. Adenosine is a potent secretagogue in the small and large intestine. We suspected that ecto-5′-nucleotidase (CD73, an intestinal enzyme) was a critical enzyme involved in the conversion of AMP to adenosine and in the pathogenesis of EPEC diarrhea. We developed a nonradioactive method for measuring ecto-5′-nucleotidase in cultured T84 cell monolayers based on the detection of phosphate release from 5′-AMP. EPEC infection triggered a release of ecto-5′-nucleotidase from the cell surface into the supernatant medium. EPEC-induced 5′-nucleotidase release was not correlated with host cell death but instead with activation of phosphatidylinositol-specific phospholipase C (PI-PLC). Ecto-5′-nucleotidase was susceptible to inhibition by zinc acetate and by α,β-methylene-adenosine diphosphate (α,β-methylene-ADP). In the Ussing chamber, these inhibitors could reverse the chloride secretory responses triggered by 5′-AMP. In addition, α,β-methylene-ADP and zinc blocked the ability of 5′-AMP to stimulate EPEC growth under nutrient-limited conditions in vitro. Ecto-5′-nucleotidase appears to be the major enzyme responsible for generation of adenosine from adenine nucleotides in the T84 cell line, and inhibitors of ecto-5′-nucleotidase, such as α,β-methylene-ADP and zinc, might be useful for treatment of the watery diarrhea produced by EPEC infection
- …