2,727 research outputs found
IT-Supported Management of Mass Casualty Incidents: The e-Triage Project
Emergencies arise out of disasters and are characterized by limited resources in terms of medical personnel and infrastructure, underlining the importance of mobilizing regional, supra-regional and/or international help to the affected regions. Effective deployment of this help is crucial, but only possible if a common operational picture among authorities, coordination centers, and staff working in the field is developed as quickly as possible. Since mass casualty incidents (MCIs) normally overwhelm the regularly available rescue resources (rescue personnel, transport vehicles, hospital capacity, etc.), a particularly effective crisis management has to be applied. In general, for co-ordination centers it is a challenge to get an immediate and accurate situation overview (i.e. number of victims, injury categories and their location). Indeed, triage and registration performed at different places by different teams maintaining different lists are indubitably an error-prone approach. Furthermore, it can happen that all later attempts to track the way of single patient, their attendants and transport vehicles are not very
successful, although this could be of key interest in scenarios with nuclear, biological or chemical hazards.
Within the e-Triage project, which is sponsored by the German Federal Ministry of Education and Research, an integrated concept for electronic registration of affected persons is under development
Comparison of Classifiers Applied to Confocal Scanning Laser Ophthalmoscopy Data
Objectives: Comparison of classification methods using data of one clinical study. The tuning of hyperparameters is assessed as part of the methods by nested-loop cross-validation. Methods: We assess the ability of 18 statistical and machine learning classifiers to detect glaucoma. The training data set is one case-control study consisting of confocal scanning laser ophthalmoscopy measurement values from 98 glaucoma patients and 98 healthy controls. We compare bootstrap estimates of the classification error by the Wilcoxon signed rank test and box-plots of a bootstrap distribution of the estimate. Results: The comparison of out-of-bag bootstrap estimators of classification errors is assessed by Spearman?s rank correlation, Wilcoxon signed rank tests and box-plots of a bootstrap distribution of the estimate. The classification methods random forests 15.4%, support vector machines 15.9%, bundling 16.3% to 17.8%, and penalized discriminant analysis 16.8% show the best results. Conclusions: Using nested-loop cross-validation we account for the tuning of hyperparameters and demonstrate the assessment of different classifiers. We recommend a block design of the bootstrap simulation to allow a statistical assessment of the bootstrap estimates of the misclassification error. The results depend on the data of the clinical study and the given size of the bootstrap sample
Phase transition and dynamical-parameter method in U(1) gauge theory
Monte Carlo simulations of the 4-dimensional compact U(1) lattice gauge
theory in the neighborhood of the transition point are made difficult by the
suppression of tunneling between the phases, which becomes very strong as soon
as the volume of the lattice grows to any appreciable size. This problem can be
avoided by making the monopole coupling a dynamical variable. In this manner
one can circumvent the tunneling barrier by effectively riding on top of the
peaks in the energy distribution which meet for sufficiently large monopole
coupling. Here we present an efficient method for determining the parameters
needed for this procedure, which can thus be implemented at low computational
cost also on large lattices. This is particularly important for a reliable
determination of the transition point. We demonstrate the working of our method
on a 16^4 lattice. We obtain an equidistribution of configurations across the
phase transition even for such a relatively large lattice size.Comment: 11 pages, latex, 2 figures included, uuencode
Quantum Effects in Black Hole Interiors
The Weyl curvature inside a black hole formed in a generic collapse grows,
classically without bound, near to the inner horizon, due to partial absorption
and blueshifting of the radiative tail of the collapse. Using a spherical
model, we examine how this growth is modified by quantum effects of conformally
coupled massless fields.Comment: 13 pages, 1 figure (not included), RevTe
Differential Regulation of Inducible Nitric Oxide Synthase Production in Bovine and Caprine Macrophages
Inducible nitric oxide synthase (iNOS) regulation in human and murine macrophages in vitro differs considerably. In this study, expression of macrophage iNOS in ruminants was addressed. Nitric oxide (NO) output by cattle and goat macrophages was as different as that by human and mouse macrophages. Bovine macrophages activated by heated Salmonella dublin or lipopolysaccharide (LPS) expressed high levels of iNOS mRNA, protein, and enzyme activity. Analogously cultured caprine macrophages did not respond to these and other activators by NO generation and iNOS expression. The lack of response was not due to general unresponsiveness to stimuli. Caprine iNOS mRNA was induced by stimulation of caprine macrophages with LPS, as shown by reverse transcription polymerase chain reaction. The level of mRNA expression in activated goat macrophages was lower than in resting bovine macrophages. A caprine 372-bp iNOS mRNA fragment that was sequenced closely resembled the bovine counterpart. This points to species-specific iNOS gene regulation
Differential Regulation of Inducible Nitric Oxide Synthase Production in Bovine and Caprine Macrophages
Inducible nitric oxide synthase (iNOS) regulation in human and murine macrophages in vitro differs considerably. In this study, expression of macrophage iNOS in ruminants was addressed. Nitric oxide (NO) output by cattle and goat macrophages was as different as that by human and mouse macrophages. Bovine macrophages activated by heated Salmonella dublin or lipopolysaccharide (LPS) expressed high levels of iNOS mRNA, protein, and enzyme activity. Analogously cultured caprine macrophages did not respond to these and other activators by NO generation and iNOS expression. The lack of response was not due to general unresponsiveness to stimuli. Caprine iNOS mRNA was induced by stimulation of caprine macrophages with LPS, as shown by reverse transcription polymerase chain reaction. The level of mRNA expression in activated goat macrophages was lower than in resting bovine macrophages. A caprine 372-bp iNOS mRNA fragment that was sequenced closely resembled the bovine counterpart. This points to species-specific iNOS gene regulatio
EDGRAFO - um sistema computacional para usuários de grafos
A computational systm for visual graph simulations is presented. It is composed of three modules that can be used individually or not. The first module implements an Abstract Data Type Graph that supports an edge-oriented way of handling graphs. The second module is a graphic editor specific for graphs and third is a visualization-routine set. The main advantage of the system is the easy interface between the modules. Therefore, a graph previously, draw with the editor can be used as an inputfor a program. it also permits the visual follow-up of an implemented algorithm.Este trabalho apresenta um sistema computacional para visualização dinâmica de programas em grafos. O sistema se compõe basicamente de três módulos que podem ser usados interligados ou não. O primeiro módulo é a implementação do Tipo Abstrato de Dados Grafo, com uma abordagem voltada para manipulação de arestas. O segundo módulo é um editor de uso específico para a construção de grafos e o terceiro módulo é um conjunto de rotinas que visa a exibição de resultados. A vantagem do sistema é justamente a fácil comunicação entre os módulos existentes. Desta forma, um grafo desenhado via editor pode ser utilizado como entrada para um programa um programa que utiliza o tipo Abstrato de Dados Grafo, bem como ter sua imagem modificada pelas rotinas do terceiro módulo
Antiferromagnetic structure and electronic properties of BaCr2As2 and BaCrFeAs2
The chromium arsenides BaCr2As2 and BaCrFeAs2 with ThCr2Si2 type structure
(space group I4/mmm; also adopted by '122' iron arsenide superconductors) have
been suggested as mother compounds for possible new superconductors. DFT-based
calculations of the electronic structure evidence metallic antiferromagnetic
ground states for both compounds. By powder neutron diffraction we confirm for
BaCr2As2 a robust ordering in the antiferromagnetic G-type structure at T_N =
580 K with mu_Cr = 1.9 mu_B at T = 2K. Anomalies in the lattice parameters
point to magneto-structural coupling effects. In BaCrFeAs2 the Cr and Fe atoms
randomly occupy the transition-metal site and G-type order is found below 265 K
with mu_Cr/Fe = 1.1 mu_B. 57Fe Moessbauer spectroscopy demonstrates that only a
small ordered moment is associated with the Fe atoms, in agreement with
electronic structure calculations with mu_Fe ~ 0. The temperature dependence of
the hyperfine field does not follow that of the total moments. Both compounds
are metallic but show large enhancements of the linear specific heat
coefficient gamma with respect to the band structure values. The metallic state
and the electrical transport in BaCrFeAs2 is dominated by the atomic disorder
of Cr and Fe and partial magnetic disorder of Fe. Our results indicate that
Neel-type order is unfavorable for the Fe moments and thus it is destabilized
with increasing iron content.Comment: 14 pages, 14 figures, submitted to Physical Review
Ensemble Pruning for Glaucoma Detection in an Unbalanced Data Set
Background: Random forests are successful classifier ensemble methods consisting of typically 100 to 1000 classification trees. Ensemble pruning techniques reduce the computational cost, especially the memory demand, of random forests by reducing the number of trees without relevant loss of performance or even with increased performance of the sub-ensemble. The application to the problem of an early detection of glaucoma, a severe eye disease with low prevalence, based on topographical measurements of the eye background faces specific challenges. Objectives: We examine the performance of ensemble pruning strategies for glaucoma detection in an unbalanced data situation. Methods: The data set consists of 102 topographical features of the eye background of 254 healthy controls and 55 glaucoma patients. We compare the area under the receiver operating characteristic curve (AUC), and the Brier score on the total data set, in the majority class, and in the minority class of pruned random forest ensembles obtained with strategies based on the prediction accuracy of greedily grown sub-ensembles, the uncertainty weighted accuracy, and the similarity between single trees. To validate the findings and to examine the influence of the prevalence of glaucoma in the data set, we additionally perform a simulation study with lower prevalences of glaucoma. Results: In glaucoma classification all three pruning strategies lead to improved AUC and smaller Brier scores on the total data set with sub-ensembles as small as 30 to 80 trees compared to the classification results obtained with the full ensemble consisting of 1000 trees. In the simulation study, we were able to show that the prevalence of glaucoma is a critical factor and lower prevalence decreases the performance of our pruning strategies. Conclusions: The memory demand for glaucoma classification in an unbalanced data situation based on random forests could effectively be reduced by the application of pruning strategies without loss of performance in a population with increased risk of glaucoma
Experimental equation of state in proton-proton and proton-antiproton collisions and phase transition to quark gluon plasma
We deduce approximate equations of state from experimental measurements in
proton-proton and proton-antiproton collisions. Thermodynamic quantities are
estimated combining the measure of average transverse momentum vs
pseudorapidity density dN/deta with the estimation of the interaction region
size from measures of Bose Einstein correlation, or from a theoretical model
which relates dN/deta to the impact parameter. The results are very similar to
theory predictions in case of crossover from hadron gas to quark gluon plasma.
According to our analysis, the possible crossover should start at dN/deta about
6 and end at dN/deta about 24.Comment: 26 pages, 6 figure
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