Institution
National Technological University
Education•Buenos Aires, Argentina•
About: National Technological University is a education organization based out in Buenos Aires, Argentina. It is known for research contribution in the topics: Pierre Auger Observatory & Catalysis. The organization has 2267 authors who have published 2980 publications receiving 36920 citations. The organization is also known as: UTN.
Papers published on a yearly basis
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TL;DR: This study assesses the state-of-the-art machine learning methods used for brain tumor image analysis in mpMRI scans, during the last seven instances of the International Brain Tumor Segmentation (BraTS) challenge, i.e., 2012-2018, and investigates the challenge of identifying the best ML algorithms for each of these tasks.
Abstract: Gliomas are the most common primary brain malignancies, with different degrees of aggressiveness, variable prognosis and various heterogeneous histologic sub-regions, i.e., peritumoral edematous/invaded tissue, necrotic core, active and non-enhancing core. This intrinsic heterogeneity is also portrayed in their radio-phenotype, as their sub-regions are depicted by varying intensity profiles disseminated across multi-parametric magnetic resonance imaging (mpMRI) scans, reflecting varying biological properties. Their heterogeneous shape, extent, and location are some of the factors that make these tumors difficult to resect, and in some cases inoperable. The amount of resected tumoris a factor also considered in longitudinal scans, when evaluating the apparent tumor for potential diagnosis of progression. Furthermore, there is mounting evidence that accurate segmentation of the various tumor sub-regions can offer the basis for quantitative image analysis towards prediction of patient overall survival. This study assesses thestate-of-the-art machine learning (ML) methods used for brain tumor image analysis in mpMRI scans, during the last seven instances of the International Brain Tumor Segmentation (BraTS) challenge, i.e., 2012-2018. Specifically, we focus on i) evaluating segmentations of the various glioma sub-regions in pre-operative mpMRI scans, ii) assessing potential tumor progression by virtue of longitudinal growth of tumor sub-regions, beyond use of the RECIST/RANO criteria, and iii) predicting the overall survival from pre-operative mpMRI scans of patients that underwent gross tota lresection. Finally, we investigate the challenge of identifying the best ML algorithms for each of these tasks, considering that apart from being diverse on each instance of the challenge, the multi-institutional mpMRI BraTS dataset has also been a continuously evolving/growing dataset.
1,165 citations
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TL;DR: In this article, the authors demonstrate that there is a correlation between the arrival directions of cosmic rays with energy above 6 x 10{sup 19} eV and the positions of active galactic nuclei lying within 75 Mpc.
Abstract: Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrate that there is a correlation between the arrival directions of cosmic rays with energy above {approx} 6 x 10{sup 19} eV and the positions of active galactic nuclei (AGN) lying within {approx} 75 Mpc. We reject the hypothesis of an isotropic distribution of these cosmic rays at over 99% confidence level from a prescribed a priori test. The correlation we observe is compatible with the hypothesis that the highest energy particles originate from nearby extragalactic sources whose flux has not been significantly reduced by interaction with the cosmic background radiation. AGN or objects having a similar spatial distribution are possible sources.
798 citations
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01 May 2004
TL;DR: The first phase of the Pierre Auger Observatory has been completed and all of the sub-systems that will be used in the full instrument to be tested under field conditions as discussed by the authors.
Abstract: Construction of the first stage of the Pierre Auger Observatory has begun. The aim of the Observatory is to collect unprecedented information about cosmic rays above 1018 eV. The first phase of the project, the construction and operation of a prototype system, known as the engineering array, has now been completed. It has allowed all of the sub-systems that will be used in the full instrument to be tested under field conditions. In this paper, the properties and performance of these sub-systems are described and their success illustrated with descriptions of some of the events recorded thus far. © 2003 Elsevier B.V. All rights reserved.
775 citations
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TL;DR: The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described and the hypothesis of a single power law is rejected with a significance greater than 6 standard deviations.
Abstract: The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.
648 citations
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National Technological University1, Technical University of Lisbon2, University of Turin3, University of Paris4, National Scientific and Technical Research Council5, New York University6, University of Naples Federico II7, University of Wisconsin–Milwaukee8, INAF9, Complutense University of Madrid10, University of California, Los Angeles11, Pierre-and-Marie-Curie University12, Karlsruhe Institute of Technology13, University of Chicago14, National University of La Plata15, Ohio State University16, Colorado State University17, Joseph Fourier University18, University of Alcalá19, Istituto Nazionale di Fisica Nucleare20, University of Salento21, University of Rome Tor Vergata22, Polish Academy of Sciences23, University of Leeds24, University of Siegen25, University of Granada26, Max Planck Society27, University of Catania28, Fermilab29, Academy of Sciences of the Czech Republic30, Radboud University Nijmegen31, University of Paris-Sud32, Pennsylvania State University33
TL;DR: The measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays is described and the interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.
Abstract: We describe the measurement of the depth of maximum, Xmax, of the longitudinal development of air showers induced by cosmic rays. Almost four thousand events above 10^18 eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106 +35/-21) g/cm^2/decade below 10^(18.24 +/- 0.05) eV and (24 +/- 3) g/cm^2/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm^2. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.
558 citations
Authors
Showing all 2278 results
Name | H-index | Papers | Citations |
---|---|---|---|
Marcos Santander | 75 | 440 | 21302 |
Sergio Dasso | 63 | 309 | 13534 |
Alexander Kusenko | 55 | 246 | 13437 |
Graciela B. Gelmini | 52 | 239 | 13465 |
A. Etchegoyen | 51 | 214 | 11316 |
O. Wainberg | 50 | 99 | 9388 |
Gonzalo Alvarez | 44 | 186 | 7454 |
B. García | 40 | 85 | 8666 |
Federico Milano | 40 | 287 | 7151 |
Alejandro Almela | 39 | 94 | 6145 |
G. De La Vega | 37 | 66 | 8147 |
Jorge Eduardo Marcovecchio | 35 | 169 | 3564 |
M. Videla | 32 | 50 | 6734 |
Ricardo L. Armentano | 30 | 203 | 3620 |
Rodolfo Horacio Mascheroni | 30 | 118 | 2288 |