103 resultados para metodi level set segmentazione immagini di nevi immagini mediche regolarizzazione


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A search for new exotic particles decaying to the VZ final state is performed, where V is either a W or a Z boson decaying into two overlapping jets and the Z decays into a pair of electrons, muons or neutrinos. The analysis uses a data sample of pp collisions corresponding to an integrated luminosity of 5 fb-1 collected by the CMS experiment at the LHC at √s=7 TeV in 2011. No significant excess is observed in the mass distribution of the VZ candidates compared with the background expectation from standard model processes. Model-dependent upper limits at the 95% confidence level are set on the product of the cross section times the branching fraction of hypothetical particles decaying to the VZ final state as a function of mass. Sequential standard model W′ bosons with masses between 700 and 940 GeV are excluded. In the Randall-Sundrum model for graviton resonances with a coupling parameter of 0.05, masses between 750 and 880 GeV are also excluded. © 2013 CERN for the benefit of the CMS collaboration.

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Results are reported of a search for a deviation in the jet production cross section from the prediction of perturbative quantum chromodynamics at next-to-leading order. The search is conducted using a 7 TeV proton-proton data sample corresponding to an integrated luminosity of 5.0 fb-1, collected with the Compact Muon Solenoid detector at the Large Hadron Collider. A deviation could arise from interactions characterized by a mass scale Λ too high to be probed directly at the LHC. Such phenomena can be modeled as contact interactions. No evidence of a deviation is found. Using the CL s criterion, lower limits are set on Λ of 9.9 TeV and 14.3 TeV at 95% confidence level for models with destructive and constructive interference, respectively. Limits obtained with a Bayesian method are also reported. © 2013 CERN.

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A search for physics beyond the standard model involving events with one or more photons, jets, and missing transverse energy has been performed by the CMS experiment. The data sample corresponds to an integrated luminosity of 4.93 fb-1 of proton-proton collisions at √s =7 TeV, produced at the Large Hadron Collider. No excess of events with large missing transverse energy is observed beyond expectations from standard model processes, and upper limits on the signal production cross sections for new physics processes are set at the 95% confidence level. The results of this search are interpreted in the context of three models of new physics: a general model of gauge-mediated supersymmetry breaking, Simplified Models, and a theory involving universal extra dimensions. In the absence of evidence for new physics, exclusion regions are derived in the parameter spaces of the respective models.[Figure not available: see fulltext.] © 2013 CERN for the benefit of the CMS collaboration.

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Low-level laser therapy (LLLT) has been used for the treatment of dentinal hypersensitivity. However, the specific LLL dose and the response mechanisms of these cells to transdentinal irradiation have not yet been demonstrated. Therefore, this study evaluated the transdentinal effects of different LLL doses on stressed odontoblast-like pulp cells MDPC-23 seeded onto the pulpal side of dentin discs obtained from human third molars. The discs were placed in devices simulating in vitro pulp chambers and the whole set was placed in 24-well plates containing plain culture medium (DMEM). After 24 h incubation, the culture medium was replaced by fresh DMEM supplemented with either 5% (simulating a nutritional stress condition) or 10% fetal bovine serum (FBS). The cells were irradiated with doses of 15 and 25 J cm-2 every 24 h, totaling three applications over three consecutive days. The cells in the control groups were removed from the incubator for the same times as used in their respective experimental groups for irradiation, though without activating the laser source (sham irradiation). After 72 h of the last active or sham irradiation, the cells were evaluated with respect to succinic dehydrogenase (SDH) enzyme production (MTT assay), total protein (TP) expression, alkaline phosphatase (ALP) synthesis, reverse transcriptase polymerase chain reaction (RT-PCR) for collagen type 1 (Col-I) and ALP, and morphology (SEM). For both tests, significantly higher values were obtained for the 25 J cm-2 dose. Regarding SDH production, supplementation of the culture medium with 5% FBS provided better results. For TP and ALP expression, the 25 J cm-2 presented higher values, especially for the 5% FBS concentration (Mann-Whitney p < 0.05). Under the tested conditions, near infrared laser irradiation at 25 J cm -2 caused transdentinal biostimulation of odontoblast-like MDPC-23 cells. © 2013 Astro Ltd.

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A search is presented for free heavy long-lived fractionally charged particles produced in pp collisions at √s=7 TeV. The data sample was recorded by the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb-1. Candidate fractionally charged particles are identified by selecting tracks with associated low charge measurements in the silicon tracking detector. Observations are found to be consistent with expectations for background processes. The results of the search are used to set upper limits on the cross section for pair production of fractionally charged, massive spin-1/2 particles that are neutral under SU(3)C and SU(2)L. We exclude at 95% confidence level such particles with electric charge ±2e/3 with masses below 310 GeV, and those with charge ±e/3 with masses below 140 GeV. © 2013 CERN. Published by the American Physical Society under the terms of the http://creativecommons.org/ licenses/by/3.0/Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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Results are presented of a search for the production of new particles decaying to pairs of partons (quarks, antiquarks, or gluons), in the dijet mass spectrum in proton-proton collisions at √s=8 TeV. The data sample corresponds to an integrated luminosity of 4.0 fb-1, collected with the CMS detector at the LHC in 2012. No significant evidence for narrow resonance production is observed. Upper limits are set at the 95% confidence level on the production cross section of hypothetical new particles decaying to quark-quark, quark-gluon, or gluon-gluon final states. These limits are then translated into lower limits on the masses of new resonances in specific scenarios of physics beyond the standard model. The limits reach up to 4.8 TeV, depending on the model, and extend previous exclusions from similar searches performed at lower collision energies. For the first time mass limits are set for the Randall-Sundrum graviton model in the dijet channel. © 2013 CERN. Published by the American Physical Society under the terms of the http://creativecommons.org/licenses/by/3.0/ Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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A search for microscopic black holes and string balls is presented, based on a data sample of pp collisions at √s=8 TeV recorded by the CMS experiment at the Large Hadron Collider and corresponding to an integrated luminosity of 12 fb-1. No excess of events with energetic multiparticle final states, typical of black hole production or of similar new physics processes, is observed. Given the agreement of the observations with the expected standard model background, which is dominated by QCD multijet production, 95% confidence level limits are set on the production of semiclassical or quantum black holes, or of string balls, corresponding to the exclusions of masses below 4.3 to 6.2 TeV, depending on model assumptions. In addition, model-independent limits are set on new physics processes resulting in energetic multiparticle final states. [Figure not available: see fulltext.] © 2013 CERN for the benefit of the CMS collaboration.

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A search is performed for heavy resonances decaying to two long-lived massive neutral particles, each decaying to leptons. The experimental signature is a distinctive topology consisting of a pair of oppositely charged leptons originating at a separated secondary vertex. Events were collected by the CMS detector at the LHC during pp collisions at √s = 7 TeV, and selected from data samples corresponding to 4.1 (5.1) fb-1 of integrated luminosity in the electron (muon) channel. No significant excess is observed above standard model expectations, and an upper limit is set with 95% confidence level on the production cross section times the branching fraction to leptons, as a function of the long-lived massive neutral particle lifetime. Copyright CERN.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The largest losses in mechanical harvesting of peanuts occur during the stage of digging, and its assessment is still incipient in Brazil. Therefore, the aim of this study was to evaluate the quantitative losses and the performance of the tractor-digger-inverter, according to soil water content and plant populations. The experiment was conducted in a completely randomized block design with a factorial scheme 2 x 3, in which the treatments consisted of two soil, water content (19.3 and 24.8%) and three populations of plants (86,111, 127,603 and 141,144 plants ha-1), with four replications. The quantitative digging losses and the set mechanized performance were evaluated. The largest amount of visible and total losses was found in the population of 141.144 plants ha-1 for the 19.3% soil water content. The harvested material flow and the tractor-digger-inverter performance were not influenced by soil water content and plant population. The water content in the pods was higher in 24.8% soil water content only for the population of 86,111 plants ha-1; the yield was higher in the populations of 141.144 and 127.603 plants ha-1, in the 19.3 e 24.8% soil water content, respectively.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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A measurement is presented of the ZZ production cross section in the ZZ -> 2l2l' decay mode with l = e, mu and l' = e, mu, tau in proton-proton collisions at root s = 7 TeV with the CMS experiment at the LHC. Results are based on data corresponding to an integrated luminosity of 5.0 fb(-1). The measured cross section sigma(pp -> ZZ) = 6.24(-080)(+0.86) (stat.)(-0.32)(+0.41) (syst.) +/- 0.14 (lumi.) pb is consistent with the standard model predictions. The following limits on ZZZ and ZZ-gamma anomalous trilinear gauge couplings are set at 95% confidence level: -0.011 < f(4)(Z) < 0.012, -0.012 < f(5)(Z) < 0.012, -0.013 < f(4)(gamma) < 0.015, and -0.014 < f(5)(gamma) < 0.014.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)