2,532 research outputs found
A scalable parallel Monte Carlo algorithm for atomistic simulations of precipitation in alloys
We present an extension of the semi-grandcanonical (SGC) ensemble that we
refer to as the variance-constrained semi-grandcanonical (VC-SGC) ensemble. It
allows for transmutation Monte Carlo simulations of multicomponent systems in
multiphase regions of the phase diagram and lends itself to scalable
simulations on massively parallel platforms. By combining transmutation moves
with molecular dynamics steps structural relaxations and thermal vibrations in
realistic alloys can be taken into account. In this way, we construct a robust
and efficient simulation technique that is ideally suited for large-scale
simulations of precipitation in multicomponent systems in the presence of
structural disorder. To illustrate the algorithm introduced in this work, we
study the precipitation of Cu in nanocrystalline Fe.Comment: 12 pages; 10 figure
MĂ©todos de inoculaciĂłn de cepas nativas de Trichoderma sp. y su efecto sobre el crecimiento y rendimiento de la quinua
The use of endophytic fungi is an effective alternative to control pathogens, improve plant metabolism and yield in crops. The objective of this study was to assess the effect of five different strains of Trichoderma sp. on the growth and yield of quinoa plants (Chenopodium quinoa Willd) by using two methods of inoculation: a) pelleted seed, and b) drenching with the endophytic fungi. A completely randomized design with a 2 x 5 factorial arrangement, plus a control with five repetitions was used. The 11 treatments were evaluated with five repetitions. Yield, and aerial and root growth variables were determined. There were no interactions between strains and inoculation methods for aerial plant growth, but there were for root growth and yield. The seed pelleting method produced a higher aerial growth compared to the drench method. In root length, the greatest values were found with the TE-7 and TE-126 strains combined with the pelleted seed method. Likewise, the TE-126 strain induced the greatest dry biomass of roots using the same method. The yield varied between 4147.6 and 3222.7 kg.ha-1 in most of the strain-method combinations, without significant differences between them. Statistically, the control always ranked last, indicating the importance of the seed inoculation. Trichoderma sp. produced increases in vegetative growth and quinoa yield, with TE-7 and TE-126 being the best strains. Furthermore, seed pelleting promoted vegetative growth of the plants, while grain yield was not affected by the inoculation method
InMyFace: Inertial and Mechanomyography-Based Sensor Fusion for Wearable Facial Activity Recognition
Recognizing facial activity is a well-understood (but non-trivial) computer
vision problem. However, reliable solutions require a camera with a good view
of the face, which is often unavailable in wearable settings. Furthermore, in
wearable applications, where systems accompany users throughout their daily
activities, a permanently running camera can be problematic for privacy (and
legal) reasons. This work presents an alternative solution based on the fusion
of wearable inertial sensors, planar pressure sensors, and acoustic
mechanomyography (muscle sounds). The sensors were placed unobtrusively in a
sports cap to monitor facial muscle activities related to facial expressions.
We present our integrated wearable sensor system, describe data fusion and
analysis methods, and evaluate the system in an experiment with thirteen
subjects from different cultural backgrounds (eight countries) and both sexes
(six women and seven men). In a one-model-per-user scheme and using a late
fusion approach, the system yielded an average F1 score of 85.00% for the case
where all sensing modalities are combined. With a cross-user validation and a
one-model-for-all-user scheme, an F1 score of 79.00% was obtained for thirteen
participants (six females and seven males). Moreover, in a hybrid fusion
(cross-user) approach and six classes, an average F1 score of 82.00% was
obtained for eight users. The results are competitive with state-of-the-art
non-camera-based solutions for a cross-user study. In addition, our unique set
of participants demonstrates the inclusiveness and generalizability of the
approach.Comment: Submitted to Information Fusion, Elsevie
Exotic and not-so-exotic candidates for ultrahigh energy cosmic rays
Ultrahigh energy cosmic rays present a major unsolved puzzle. Not only do we not know their origin, but we also have no really solid evidence that they are protons or iron nuclei—the two most popular candidates. We examine briefly a couple of “nonstandard” possibilities: light magnetic monopoles, which are rather exotic, and nuclei heavier than iron, which are perhaps less exotic, but have many attractive features.Facultad de Ciencias Exacta
A pot of gold at the end of the cosmic “raynbow”?
We critically review the common belief that ultrahigh energy cosmic rays are protons or atomic nuclei with masses not exceeding that of iron. We find that heavier nuclei are indeed possible, and discuss possible sources and acceleration mechanisms for such primaries. We also show detailed simulations of extensive air showers produced by “superheavy” nuclei, and discuss prospects for their detection in future experiments.Facultad de Ciencias Exacta
A pot of gold at the end of the cosmic “raynbow”?
We critically review the common belief that ultrahigh energy cosmic rays are protons or atomic nuclei with masses not exceeding that of iron. We find that heavier nuclei are indeed possible, and discuss possible sources and acceleration mechanisms for such primaries. We also show detailed simulations of extensive air showers produced by “superheavy” nuclei, and discuss prospects for their detection in future experiments.Facultad de Ciencias Exacta
β(2 → 1)-β(2 → 6) and β(2 → 1) fructans protect from impairment of intestinal tight junction's gene expression and attenuate human dendritic cell responses in a fructan-dependent fashion
β(2 → 1)-β(2 → 6) branched graminan-type fructans (GTFs) and β(2 → 1) linear fructans (ITFs) possess immunomodulatory properties and protect human intestinal barrier function, however the mechanisms underlying these effects are not well studied. Herein, GTFs and ITFs effects with different degree of polymerization (DP) values on tight junctions (TJs) genes CLDN-1, -2 and -3, CDH1, OCLN and TJP1 were studied in Caco-2 gut epithelial cells, under homeostatic and inflammatory conditions. Also, cytokine production in dendritic cells (DCs) was studied. Higher DP fructans decreased the expression of the pore forming CLDN-2. Higher DP GTFs enhanced CLDN-3, OCLN, and TJP-1. Fructans prevented mRNA dysregulation of CLDN-1, -2 and -3 induced by the barrier disruptors A23187 and deoxynivalenol in a fructan-type dependent fashion. The production of pro-inflammatory cytokines MCP-1/CCL2, MIP-1α/CCL3 and TNFα by DCs was also attenuated in a fructan-type dependent manner and was strongly attenuated by DCs cultured with medium of Caco-2 cells which were pre-exposed to fructans. Our data show that specific fructans have TJs and DCs modulating effects and contribute to gut homeostasis. This might serve to design effective dietary means to prevent intestinal inflammation.</p
High energy physics in the atmosphere: phenomenology of cosmic ray air showers
The properties of cosmic rays with energies above 106 GeV have to be deduced from the spacetime structure and particle content of the air showers which they initiate. In this review we summarize the phenomenology of these giant air showers. We describe the hadronic interaction models used to extrapolate results from collider data to ultra high energies, and discuss the prospects for insights into forward physics at the LHC. We also describe the main electromagnetic processes that govern the longitudinal shower evolution, as well as the lateral spread of particles. Armed with these two principal shower ingredients and motivation from the underlying physics, we provide an overview of some of the different methods proposed to distinguish primary species. The properties of neutrino interactions and the potential of forthcoming experiments to isolate deeply penetrating showers from baryonic cascades are also discussed. We finally venture into a terra incognita endowed with TeV-scale gravity and explore anomalous neutrino-induced showers.Facultad de Ciencias Exacta
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