2,896 research outputs found
Dynamical Processing of Geophysical Signatures based on SPOT-5 Remote Sensing Imagery
An intelligent post-processing computational paradigm based on the use of dynamical filtering techniques modified to enhance the quality of reconstruction of geophysical signatures based on Spot-5 imagery is proposed. As a matter of particular study, a robust algorithm is reported for the analysis of the dynamic behavior of geophysical indexes extracted from the real-world remotely sensed scenes. The simulation results verify the efficiency of the approach as required for decision support in resources management
Chemostat culture systems support diverse bacteriophage communities from human feces
BACKGROUND: Most human microbiota studies focus on bacteria inhabiting body surfaces, but these surfaces also are home to large populations of viruses. Many are bacteriophages, and their role in driving bacterial diversity is difficult to decipher without the use of in vitro ecosystems that can reproduce human microbial communities. RESULTS: We used chemostat culture systems known to harbor diverse fecal bacteria to decipher whether these cultures also are home to phage communities. We found that there are vast viral communities inhabiting these ecosystems, with estimated concentrations similar to those found in human feces. The viral communities are composed entirely of bacteriophages and likely contain both temperate and lytic phages based on their similarities to other known phages. We examined the cultured phage communities at five separate time points over 24 days and found that they were highly individual-specific, suggesting that much of the subject-specificity found in human viromes also is captured by this culture-based system. A high proportion of the community membership is conserved over time, but the cultured communities maintain more similarity with other intra-subject cultures than they do to human feces. In four of the five subjects, estimated viral diversity between fecal and cultured communities was highly similar. CONCLUSIONS: Because the diversity of phages in these cultured fecal communities have similarities to those found in humans, we believe these communities can serve as valuable ecosystems to help uncover the role of phages in human microbial communities
High-accuracy numerical models of Brownian thermal noise in thin mirror coatings
Brownian coating thermal noise in detector test masses is limiting the sensitivity of current gravitational-wave detectors on Earth. Therefore, accurate numerical models can inform the ongoing effort to minimize Brownian coating thermal noise in current and future gravitational-wave detectors. Such numerical models typically require significant computational resources and time, and often involve closed-source commercial codes. In contrast, open-source codes give complete visibility and control of the simulated physics and enable direct assessment of the numerical accuracy. In this article, we use the open-source SpECTRE numerical-relativity code and adopt a novel discontinuous Galerkin numerical method to model Brownian coating thermal noise. We demonstrate that SpECTRE achieves significantly higher accuracy than a previous approach at a fraction of the computational cost. Furthermore, we numerically model Brownian coating thermal noise in multiple sub-wavelength crystalline coating layers for the first time. Our new numerical method has the potential to enable fast exploration of realistic mirror configurations, and hence to guide the search for optimal mirror geometries, beam shapes and coating materials for gravitational-wave detectors
High-accuracy numerical models of Brownian thermal noise in thin mirror coatings
Brownian coating thermal noise in detector test masses is limiting the
sensitivity of current gravitational-wave detectors on Earth. Therefore,
accurate numerical models can inform the ongoing effort to minimize Brownian
coating thermal noise in current and future gravitational-wave detectors. Such
numerical models typically require significant computational resources and
time, and often involve closed-source commercial codes. In contrast,
open-source codes give complete visibility and control of the simulated physics
and enable direct assessment of the numerical accuracy. In this article, we use
the open-source SpECTRE numerical-relativity code and adopt a novel
discontinuous Galerkin numerical method to model Brownian coating thermal
noise. We demonstrate that SpECTRE achieves significantly higher accuracy than
a previous approach at a fraction of the computational cost. Furthermore, we
numerically model Brownian coating thermal noise in multiple sub-wavelength
crystalline coating layers for the first time. Our new numerical method has the
potential to enable fast exploration of realistic mirror configurations, and
hence to guide the search for optimal mirror geometries, beam shapes and
coating materials for gravitational-wave detectors.Comment: 9 pages, 5 figures. Results are reproducible with the ancillary input
file
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
- …