3,266 research outputs found
Application of large area SiPMs for the readout of a plastic scintillator based timing detector
In this study an array of eight 6 mm x 6 mm area SiPMs was coupled to the end
of a long plastic scintillator counter which was exposed to a 2.5 GeV/c muon
beam at the CERN PS. Timing characteristics of bars with dimensions 150 cm x 6
cm x 1 cm and 120 cm x 11 cm x 2.5 cm have been studied. An 8-channel SiPM
anode readout ASIC (MUSIC R1) based on a novel low input impedance current
conveyor has been used to read out and amplify SiPMs independently and sum the
signals at the end. Prospects for applications in large-scale particle physics
detectors with timing resolution below 100 ps are provided in light of the
results
Application of large area SiPMs for the readout of a plastic scintillator based timing detector
In this study an array of eight 6 mm x 6 mm area SiPMs was coupled to the end
of a long plastic scintillator counter which was exposed to a 2.5 GeV/c muon
beam at the CERN PS. Timing characteristics of bars with dimensions 150 cm x 6
cm x 1 cm and 120 cm x 11 cm x 2.5 cm have been studied. An 8-channel SiPM
anode readout ASIC (MUSIC R1) based on a novel low input impedance current
conveyor has been used to read out and amplify SiPMs independently and sum the
signals at the end. Prospects for applications in large-scale particle physics
detectors with timing resolution below 100 ps are provided in light of the
results
Sensitivity of Cirrus and Mixed-phase Clouds to the Ice Nuclei Spectra in McRAS-AC: Single Column Model Simulations
The salient features of mixed-phase and ice clouds in a GCM cloud scheme are examined using the ice formation parameterizations of Liu and Penner (LP) and Barahona and Nenes (BN). The performance of LP and BN ice nucleation parameterizations were assessed in the GEOS-5 AGCM using the McRAS-AC cloud microphysics framework in single column mode. Four dimensional assimilated data from the intensive observation period of ARM TWP-ICE campaign was used to drive the fluxes and lateral forcing. Simulation experiments where established to test the impact of each parameterization in the resulting cloud fields. Three commonly used IN spectra were utilized in the BN parameterization to described the availability of IN for heterogeneous ice nucleation. The results show large similarities in the cirrus cloud regime between all the schemes tested, in which ice crystal concentrations were within a factor of 10 regardless of the parameterization used. In mixed-phase clouds there are some persistent differences in cloud particle number concentration and size, as well as in cloud fraction, ice water mixing ratio, and ice water path. Contact freezing in the simulated mixed-phase clouds contributed to transfer liquid to ice efficiently, so that on average, the clouds were fully glaciated at T approximately 260K, irrespective of the ice nucleation parameterization used. Comparison of simulated ice water path to available satellite derived observations were also performed, finding that all the schemes tested with the BN parameterization predicted 20 average values of IWP within plus or minus 15% of the observations
A Process for Co-Designing Educational Technology Systems for Refugee Children
There is a growing interest in the potential for technology to facilitate emergency education of refugee children. However, designing in this space requires knowledge of the displaced population and the contextual dynamics surrounding it. Design should therefore be informed by both existing research across relevant disciplines, and from the practical experience of those who are on the ground facing the problem in real life. This paper describes a process for designing appropriate technology for these settings. The process draws on literature from emergency education, student engagement and motivation, educational technology, and participatory design. We emphasise a thorough understanding of the problem definition, the nature of the emergency, and of socio-cultural aspects that can inform the design process. We describe how this process was implemented leading to the design of a digital learning space for children living in a refugee camp in Greece. This drew on involving different groups of participants such as social-workers, parents, and children
Capacidad antioxidante total de la dieta vs. balance redox
La asociación inversa que existe entre las dietas ricas en frutas y hortalizas y la aparición de enfermedades crónicas no transmisibles sigue acaparando importancia a nivel mundial en las líneas de investigación de la nutrición y la dietética. Es por eso que incluir en las estimaciones dietéticas, los aspectos relacionados con la capacidad antioxidante que aportan los alimentos y evaluar la alimentación ya no solo desde la óptica de los indicadores clásicos de calidad, constituye un enfoque novedoso y que resulta importante por su implicación en el estrés oxidativo en la etiología de disímiles enfermedades. Este trabajo presenta los principales aspectos sobre la relación entre la dieta y el balance de las reacciones redox en el organismo, sin pretender abordarlos de forma absoluta e integral.
Palabras clave: Capacidad antioxidante, dieta, balance redox, estrés oxidativo.
Abstract
The inverse association that exists between diets rich in fruits and vegetables and the appearance of chronic non-communicable diseases continues to gain importance worldwide in the research lines of nutrition and dietetics. That is why including in the dietary estimates, the aspects related to the antioxidant capacity provided by foods and evaluating the diet not only from the point of view of the classic quality indicators, constitutes a novel approach that is important due to its involvement in oxidative stress in the etiology of dissimilar diseases. This work presents the main aspects of the relationship between diet and the balance of redox reactions in the body, without attempting to address them in an absolute and comprehensive way.
Keywords: Antioxidant capacity, diet, redox balance, oxidative stress
Review of Reactor Antineutrino Experiments
As discussed elsewhere, the measurement of a non-zero value for
would open up a wide range of possibilities to explore CP-violation and the
mass hierarchy. Experimental methods to measure currently the unknown mixing
angle include accelerator searches for the appearance
and precise measurements of reactor antineutrino disappearance. The reactor
antineutrino experiments are designed to search for a non-vanishing mixing
angle with unprecedented sensitivity. This document describes
current reactor antineutrino experiments and synergy between accelerator
searches for the appearance and precise measurements of reactor
antineutrino disappearance.Comment: 8 pages, 2 figures, Review talk given at NuFact 2011, XIIIth
InternationalWorkshop on Neutrino Factories, Super beams and Beta beams,
CERN/UNIGE, Geneva, Switzerland, August 1-6, 201
Reducing model bias in a deep learning classifier using domain adversarial neural networks in the MINERvA experiment
We present a simulation-based study using deep convolutional neural networks
(DCNNs) to identify neutrino interaction vertices in the MINERvA passive
targets region, and illustrate the application of domain adversarial neural
networks (DANNs) in this context. DANNs are designed to be trained in one
domain (simulated data) but tested in a second domain (physics data) and
utilize unlabeled data from the second domain so that during training only
features which are unable to discriminate between the domains are promoted.
MINERvA is a neutrino-nucleus scattering experiment using the NuMI beamline at
Fermilab. -dependent cross sections are an important part of the physics
program, and these measurements require vertex finding in complicated events.
To illustrate the impact of the DANN we used a modified set of simulation in
place of physics data during the training of the DANN and then used the label
of the modified simulation during the evaluation of the DANN. We find that deep
learning based methods offer significant advantages over our prior track-based
reconstruction for the task of vertex finding, and that DANNs are able to
improve the performance of deep networks by leveraging available unlabeled data
and by mitigating network performance degradation rooted in biases in the
physics models used for training.Comment: 41 page
I-TASSER server for protein 3D structure prediction
<p>Abstract</p> <p>Background</p> <p>Prediction of 3-dimensional protein structures from amino acid sequences represents one of the most important problems in computational structural biology. The community-wide Critical Assessment of Structure Prediction (CASP) experiments have been designed to obtain an objective assessment of the state-of-the-art of the field, where I-TASSER was ranked as the best method in the server section of the recent 7th CASP experiment. Our laboratory has since then received numerous requests about the public availability of the I-TASSER algorithm and the usage of the I-TASSER predictions.</p> <p>Results</p> <p>An on-line version of I-TASSER is developed at the KU Center for Bioinformatics which has generated protein structure predictions for thousands of modeling requests from more than 35 countries. A scoring function (C-score) based on the relative clustering structural density and the consensus significance score of multiple threading templates is introduced to estimate the accuracy of the I-TASSER predictions. A large-scale benchmark test demonstrates a strong correlation between the C-score and the TM-score (a structural similarity measurement with values in [0, 1]) of the first models with a correlation coefficient of 0.91. Using a C-score cutoff > -1.5 for the models of correct topology, both false positive and false negative rates are below 0.1. Combining C-score and protein length, the accuracy of the I-TASSER models can be predicted with an average error of 0.08 for TM-score and 2 Å for RMSD.</p> <p>Conclusion</p> <p>The I-TASSER server has been developed to generate automated full-length 3D protein structural predictions where the benchmarked scoring system helps users to obtain quantitative assessments of the I-TASSER models. The output of the I-TASSER server for each query includes up to five full-length models, the confidence score, the estimated TM-score and RMSD, and the standard deviation of the estimations. The I-TASSER server is freely available to the academic community at <url>http://zhang.bioinformatics.ku.edu/I-TASSER</url>.</p
Measurement of the muon anti-neutrino double-differential cross section for quasi-elastic scattering on hydrocarbon at~ GeV
We present double-differential measurements of anti-neutrino quasi-elastic
scattering in the MINERvA detector. This study improves on a previous single
differential measurement by using updated reconstruction algorithms and
interaction models, and provides a complete description of observed muon
kinematics in the form of a double-differential cross section with respect to
muon transverse and longitudinal momentum. We include in our signal definition
zero-meson final states arising from multi-nucleon interactions and from
resonant pion production followed by pion absorption in the primary nucleus. We
find that model agreement is considerably improved by a model tuned to MINERvA
inclusive neutrino scattering data that incorporates nuclear effects such as
weak nuclear screening and two-particle, two-hole enhancements.Comment: 47 pages, 31 figure
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