429 research outputs found
Traducción al castellano comentada del libro de poemas Eu, de Augusto dos Anjos
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Estudos de Tradução, Florianópolis, 2015.Este trabalho discute elementos poéticos, rítmicos e estéticos em geral de minha tradução para o espanhol dos poemas do livro Eu, do poeta paraibano Augusto dos Anjos. Destaca-se a poética como um aspecto fundamental para traduzir literatura e se discute o uso do grotesco e da dissonância na realização do ato poético. Junto a isso, ganha relevância o papel das metáforas em combinação com outros componentes sonoros da poesia. O debate se focaliza na prosódia e estética da tradução, abrindo passagem entre os tropos. Para dar sustentação teórica ao exercício da tradução, abordo diversas teorias aplicadas à tradução de poesia, mas dando maior ênfase à teoria constituída por Henri Meschonnic.Abstract : This work discusses some poetic, rhythmic and aesthetic elements in general of my Spanish translation of the book of poems Eu, by the Brazilian poet Augusto dos Anjos. Poetics is highlighted as a fundamental aspect to translate literature, and I discuss the use of grotesque and dissonance on the poetic fact. Along with that, the role of metaphors becomes relevant in combination with others poem's sound components. I examine prosody and aesthetics of translation, opening passage between tropes. To give a theoretical basis to the translation exercise, I review various theories applied to poetry translation, but specially the Henri Meschonnic theory
Mapping complex cell morphology in the grey matter with double diffusion encoding MR: a simulation study
This paper investigates the impact of cell body (soma) size and branching of
cellular projections on diffusion MR imaging (dMRI) and spectroscopy (dMRS)
signals for both standard single diffusion encoding (SDE) and more advanced
double diffusion encoding (DDE) measurements using numerical simulations. The
aim is to study the ability of dMRI/dMRS to characterize the complex morphology
of brain grey matter, focusing on these two distinctive features. To this end,
we employ a recently developed framework to create realistic meshes for Monte
Carlo simulations, covering a wide range of soma sizes and branching orders of
cellular projections, for diffusivities reflecting both water and metabolites.
For SDE sequences, we assess the impact of soma size and branching order on the
signal b-value dependence as well as the time dependence of the apparent
diffusion coefficient (ADC). For DDE sequences, we assess their impact on the
mixing time dependence of the signal angular modulation and of the estimated
microscopic anisotropy, a promising contrast derived from DDE measurements. The
SDE results show that soma size has a measurable impact on both the b-value and
diffusion time dependence, for both water and metabolites. On the other hand,
branching order has little impact on either, especially for water. In contrast,
the DDE results show that soma size has a measurable impact on the signal
angular modulation at short mixing times and the branching order significantly
impacts the mixing time dependence of the signal angular modulation as well as
of the derived microscopic anisotropy, for both water and metabolites. Our
results confirm that soma size can be estimated from SDE based techniques, and
most importantly, show for the first time that DDE measurements show
sensitivity to the branching of cellular projections, paving the way for
non-invasive characterization of grey matter morphology
Spin relaxation and anticrossing in quantum dots: Rashba versus Dresselhaus spin-orbit coupling
The spin-orbit splitting of the electron levels in a two-dimensional quantum
dot in a perpendicular magnetic field is studied. It is shown that at the point
of an accidental degeneracy of the two lowest levels above the ground state the
Rashba spin-orbit coupling leads to a level anticrossing and to mixing of
spin-up and spin-down states, whereas there is no mixing of these levels due to
the Dresselhaus term. We calculate the relaxation and decoherence times of the
three lowest levels due to phonons. We find that the spin relaxation rate as a
function of a magnetic field exhibits a cusp-like structure for Rashba but not
for Dresselhaus spin-orbit interaction.Comment: 6 pages, 1 figur
SANDI: a compartment-based model for non-invasive apparent soma and neurite imaging by diffusion MRI
This work introduces a compartment-based model for apparent soma and neurite
density imaging (SANDI) using non-invasive diffusion-weighted MRI (DW-MRI). The
existing conjecture in brain microstructure imaging trough DW-MRI presents
water diffusion in white (WM) and grey (GM) matter as restricted diffusion in
neurites, modelled by infinite cylinders of null radius embedded in the
hindered extra-neurite water. The extra-neurite pool in WM corresponds to water
in the extra-axonal space, but in GM it combines water in the extra-cellular
space with water in soma. While several studies showed that this microstructure
model successfully describe DW-MRI data in WM and GM at b<3 ms/{\mum^2}, it has
been also shown to fail in GM at high b values (b>>3 ms/{\mum^2}). Here we
hypothesize that the unmodelled soma compartment may be responsible for this
failure and propose SANDI as a new model of brain microstructure where soma
(i.e. cell body of any brain cell type: from neuroglia to neurons) is
explicitly included. We assess the effects of size and density of soma on the
direction-averaged DW-MRI signal at high b values and the regime of validity of
the model using numerical simulations and comparison with experimental data
from mouse (bmax = 40 ms/{/mum^2}) and human (bmax = 10 ms/{\mum^2}) brain. We
show that SANDI defines new contrasts representing new complementary
information on the brain cyto- and myelo-architecture. Indeed, we show for the
first-time maps from 25 healthy human subjects of MR soma and neurite signal
fractions, that remarkably mirror contrasts of histological images of brain
cyto- and myelo-architecture. Although still under validation, SANDI might
provide new insight into tissue architecture by introducing a new set of
biomarkers of potential great value for biomedical applications and pure
neuroscience
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