7,161 research outputs found
Rastreamento de Jogadores de Futebol em Seqüência de Imagens
Este trabalho propõe um sistema de rastreamento visual de jogadores de futebol, o qual estima as trajetórias 2D em seqüências de imagens capturadas por câmeras fixas, instaladas ao redor de um campo de futebol. O rastreamento permite determinar diversos parâmetros como, por exemplo, a velocidade e a distância percorrida pelos jogadores durante uma partida, a região de maior movimentação da equipe no campo, etc. O sistema proposto segue uma abordagem probabilística, alcançando bons resultados iniciais. Os experimentos mostraram que uma implementação inicial do sistema, utilizando somente informação de variação da intensidade luminosa das imagens, já apresenta resultados eficazes e eficientes e permite vislumbrar melhorias significativas a serem desenvolvidas
An orally active formulation of angiotensin-(1-7) produces an antithrombotic effect
INTRODUCTION AND OBJECTIVE: The heptapeptide angiotensin-(1-7) is a component of the renin-angiotensin system, which promotes many beneficial cardiovascular effects, including antithrombotic activity. We have recently shown that the antithrombotic effect of angiotensin-(1-7) involves receptor Mas-mediated NO-release from platelets. Here, we describe an orally active formulation based on angiotensin-(1-7) inclusion in cyclodextrin [Ang-(1-7)- CyD] as an antithrombotic agent. Cyclodextrins are pharmaceutical tools that are used to enhance drug stability, absorption across biological barriers and gastric protection. METHOD: To test the antithrombotic effect of Ang-(1-7)-CyD, thrombus formation was induced in the abdominal vena cava of spontaneously hypertensive rats that were pretreated either acutely or chronically with Ang-(1-7)-CyD. Male Mas-knockout and wild-type mice were used to verify the role of the Mas receptor on the effect of Ang-(1-7)-CyD. RESULTS: Acute or chronic oral treatment with Ang-(1-7)-CyD promoted an antithrombotic effect (measured by thrombus weight; all values are, respectively, untreated vs. treated animals) in spontaneously hypertensive rats (acute: 2.86 + 0.43 mg vs. 1.14 + 0.40 mg; chronic: 4.27 + 1.03 mg vs. 1.39 + 0.68 mg). This effect was abolished in Mas-knockout mice (thrombus weight in Mas wild-type: 0.76 + 0.10 mg vs. 0.37 + 0.02 mg; thrombus weight in Mas-knockout: 0.96 + 0.11 mg vs. 0.87 + 0.14 mg). Furthermore, the antithrombotic effect of Ang-(1-7)-CyD was associated with an increase in the plasma level of Angiotensin-(1-7). CONCLUSION: These results show for the first time that the oral formulation Ang-(1-7)-CyD has biological activity and produces a Mas-dependent antithrombotic effect
Nearest-Neighbour Interaction from an Abelian Symmetry and Deviations from Hermiticity
We show that Nearest-Neighbour Interaction (NNI) textures for the quark mass
matrices can be obtained through the introduction of an Abelian flavour
symmetry. The minimal realisation requires a Z_4 symmetry in the context of a
two Higgs doublet model. It is further shown that the NNI textures can be in
agreement with all present experimental data on quark masses and mixings,
provided one allows for deviations of Hermiticity in the quark mass matrices at
the 20% level.Comment: 11 pages, 1 figure; references and minor corrections adde
Spectro-ViT: A Vision Transformer Model for GABA-edited MRS Reconstruction Using Spectrograms
Purpose: To investigate the use of a Vision Transformer (ViT) to
reconstruct/denoise GABA-edited magnetic resonance spectroscopy (MRS) from a
quarter of the typically acquired number of transients using spectrograms.
Theory and Methods: A quarter of the typically acquired number of transients
collected in GABA-edited MRS scans are pre-processed and converted to a
spectrogram image representation using the Short-Time Fourier Transform (STFT).
The image representation of the data allows the adaptation of a pre-trained ViT
for reconstructing GABA-edited MRS spectra (Spectro-ViT). The Spectro-ViT is
fine-tuned and then tested using \textit{in vivo} GABA-edited MRS data. The
Spectro-ViT performance is compared against other models in the literature
using spectral quality metrics and estimated metabolite concentration values.
Results: The Spectro-ViT model significantly outperformed all other models in
four out of five quantitative metrics (mean squared error, shape score,
GABA+/water fit error, and full width at half maximum). The metabolite
concentrations estimated (GABA+/water, GABA+/Cr, and Glx/water) were consistent
with the metabolite concentrations estimated using typical GABA-edited MRS
scans reconstructed with the full amount of typically collected transients.
Conclusion: The proposed Spectro-ViT model achieved state-of-the-art results
in reconstructing GABA-edited MRS, and the results indicate these scans could
be up to four times faster
Quantum Conductance in Semimetallic Bismuth Nanocontacts
Electronic transport properties of bismuth nanocontacts are analyzed by means
of a low temperature scanning tunneling microscope. The subquantum steps
observed in the conductance versus elongation curves give evidence of atomic
rearrangements in the contact. The underlying quantum nature of the conductance
reveals itself through peaks in the conductance histograms. The shape of the
conductance curves at 77 K is well described by a simple gliding mechanism for
the contact evolution during elongation. The strikingly different behaviour at
4 K suggests a charge carrier transition from light to heavy ones as the
contact cross section becomes sufficiently small.Comment: 5 pages including 4 figures. Accepted for publication in Phys. Rev.
Let
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IDENTIFICAÇÃO DA DUPLA EXCEPCIONALIDADE EM ADULTO: UM CASO DE ALTAS HABILIDADES/SUPERDOTAÇÃO E TDAH
O objetivo do presente artigo foi relatar um caso de avaliação neuropsicológica conduzida junto a um adulto que resultou no diagnóstico de dupla excepcionalidade relacionada à presença de Altas Habilidades/Superdotação (AH/SD) e Transtorno de Déficit de Atenção/Hiperatividade (TDAH). A avaliação contou com sete sessões compostas de administração de instrumentos psicológicos e neuropsicológicos, juntamente de observações clínico-qualitativas. Teve-se como aporte teórico para o atendimento o modelo de “Competências funcionais em neuropsicologia clínica”. Os dados foram agrupados em habilidades neurocognitivas avaliadas, a saber: inteligência, funções executivas chamadas “frias”/cognitivas, habilidades escolares e habilidades socioemocionais. De modo geral, os resultados demonstraram altos valores de Quociente Intelectual, mas déficits em funções executivas e em habilidades socioemocionais. O perfil apresentado pelo paciente foi discutido de acordo com a literatura na área, e, consequentemente, de modo que o identificou com dupla excepcionalidade entre AH/SD e TDAH. Discussões sobre a identificação tardia do quadro também são apresentadas, bem como sugestões para o suporte adequado às suas necessidades específicas
COVID-19 mental health care toolkit: an international collaborative effort by Early Career Psychiatrists section
The collaborative effort of an international research team from the Early Career Psychiatrists section of the World Psychiatry Association has brought about an easy-to-use, quick and stepwise mental health care toolkit for the identification and appropriate referral of those in need of mental health care during the pandemic. This simple guide can be applied in the general outpatient setting and is catered for all healthcare professionals, regardless of their expertise within the mental health field with minimal training. It is our hope that by incorporating this toolkit into our daily clinical care during the pandemic for high-risk patients and patients with non-specific complaints, we will be able to bridge the mental health gap present in our society
Measurement of the Strong Coupling Constant from Inclusive Jet Production at the Tevatron Collider
We report a measurement of the strong coupling constant, ,
extracted from inclusive jet production in collisions at
1800 GeV. The QCD prediction for the evolution of with
jet transverse energy is tested over the range 40<<450 GeV using
for the renormalization scale. The data show good agreement with QCD in
the region below 250 GeV. In the text we discuss the data-theory comparison in
the region from 250 to 450 GeV. The value of at the mass of the
boson averaged over the range 40<<250 GeV is found to be
. The associated theoretical uncertainties are mainly due to the choice
of renormalization scale (^{+6%}_{-4%}) and input parton distribution
functions (5%).Comment: 7 pages, 3 figures, using RevTeX. Submitted to Physical Review
Letter
Measurement of the lepton charge asymmetry in W-boson decays produced in p-pbar collisions
We describe a measurement of the charge asymmetry of leptons from W boson
decays in the rapidity range 0 enu, munu events from
110+/-7 pb^{-1}of data collected by the CDF detector during 1992-95. The
asymmetry data constrain the ratio of d and u quark momentum distributions in
the proton over the x range of 0.006 to 0.34 at Q2 \approx M_W^2. The asymmetry
predictions that use parton distribution functions obtained from previously
published CDF data in the central rapidity region (0.0<|y_l|<1.1) do not agree
with the new data in the large rapidity region (|y_l|>1.1).Comment: 13 pages, 3 tables, 1 figur
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