68 research outputs found
Detecting the stages of hyperplasia formation in the breast ducts using ultrasound B-scan images
Presented at the 2006 3rd IEEE International Symposium on Biomedical Imaging: From Nano to Macro, Arlington, VA, DOI: http://dx.doi.org/10.1109/ISBI.2006.1625064A stochastic decomposition algorithm of the RF Echo into its
coherent and diffuse components is used towards estimating the
structural parameters of the hyperplastic stages of the breast tissue
leading to early breast cancer detection. The discrimination power
of the various parameters is studied under a host of conditions
such as varying resolution and SNR values using a point scatterer
model simulator that mimics epithelium hyperplastic growth in the
breast ducts. It is shown that three parameters, in particular, the
number of coherent scatterers, the Rayleigh scattering degree and
the energy of the diffuse scatterers, prove to show very high ability
to discriminate between various stages of hyperplasia even in
cases of low resolution and SNR values. Values of Az>0.942 were
obtained for resolution less than or equal to 0.4mm even in low
SNR values, then it drops below the 0.9 range as the resolution
exceeds the 0.4mm range
Tissue characterization and detection of dysplasia using scattered light
Paper presented at the 2006 3rd IEEE International Symposium on Biomedical Imaging: From Nano to Macro, Arlington, VA.In this paper, the structural parameters of dysplasia formation in
the epithelial tissue are estimated using a stochastic decomposition
algorithm (SDM) by means of scattered light. We extract texture
parameters obtained from the decomposition that capture the
signature of dysplasia formation. These parameters include the
number and mean energy of coherent scatterers; deviation from
Rayleigh scattering; average energy of diffuse scatterers; and
normalized correlation coefficient. The tests are performed on
simulations, and tissue-mimicking phantom data. The simulations
are based on the light scattered from the cells with varying
parameters such as, index of refraction, number of cells, and size
of cells. The obtained results demonstrate the proof-of-concept in
being able to differentiate between tissue structures that give rise
to changes in cell morphology as well as other physical properties
such as change in index of refraction. Fusing all the estimated
parameter set together results in the differentiation performance
(Az value) up to 1(perfect detection) for simulated data, and
Az>0.927 for the phantom data
Does chess need intelligence? â A study with young chess players
Although it is widely acknowledged that chess is the best example of an intellectual activity
among games, evidence showing the association between any kind of intellectual ability and
chess skill has been remarkably sparse. One of the reasons is that most of the studies
investigated only one factor (e.g., intelligence), neglecting other factors relevant for the acquisition of chess skill (e.g., amount of practice, years of experience). The present study investigated the chess skill of 57 young chess players using measures of intelligence (WISC
III), practice, and experience. Although practice had the most influence on chess skill, intelligence explained some variance even after the inclusion of practice. When an elite subsample of 23 children was tested, it turned out that intelligence was not a significant factor
in chess skill, and that, if anything, it tended to correlate negatively with chess skill. This
unexpected result is explained by a negative correlation between intelligence and practice in the elite subsample. The study demonstrates the dangers of focusing on a single factor in complex
real-world situations where a number of closely interconnected factors operate
The Neural Correlates of Theory of Mindand their Role during Empathy and theGame of Chess: A functional MagneticResonance Imaging Study
Chess involves the capacity to reason iteratively about potential intentional choices of an opponent and therefore involves high levels of explicit theory of mind [ToM] (i.e. ability to infer mental states of others) alongside clear, strategic rule-based decision-making. Functional magnetic resonance imaging was used on 12 healthy male novice chess players to identify cortical regions associated with chess, ToM and empathizing. The blood-oxygenation-level-dependent (BOLD) response for chess and empathizing tasks was extracted from each ToM region. Results showed neural overlap between ToM, chess and empathizing tasks in right-hemisphere temporo-parietal junction (TPJ) [BA40], left-hemisphere superior temporal gyrus [BA22] and posterior cingulate gyrus [BA23/31]. TPJ is suggested to underlie the capacity to reason iteratively about another's internal state in a range of tasks. Areas activated by ToM and empathy included right-hemisphere orbitofrontal cortex and bilateral middle temporal gyrus: areas that become active when there is need to inhibit one's own experience when considering the internal state of another and for visual evaluation of action rationality. Results support previous findings, that ToM recruits a neural network with each region sub-serving a supporting role depending on the nature of the task itself. In contrast, a network of cortical regions primarily located within right- and left-hemisphere medial-frontal and parietal cortex, outside the internal representational network, was selectively recruited during the chess task. We hypothesize that in our cohort of novice chess players the strategy was to employ an iterative thinking pattern which in part involved mentalizing processes and recruited core ToM-related regions
A História da Alimentação: balizas historiogråficas
Os M. pretenderam traçar um quadro da HistĂłria da Alimentação, nĂŁo como um novo ramo epistemolĂłgico da disciplina, mas como um campo em desenvolvimento de prĂĄticas e atividades especializadas, incluindo pesquisa, formação, publicaçÔes, associaçÔes, encontros acadĂȘmicos, etc. Um breve relato das condiçÔes em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biolĂłgica, a econĂŽmica, a social, a cultural e a filosĂłfica!, assim como da identificação das contribuiçÔes mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histĂłrica, foi ela organizada segundo critĂ©rios morfolĂłgicos. A seguir, alguns tĂłpicos importantes mereceram tratamento Ă parte: a fome, o alimento e o domĂnio religioso, as descobertas europĂ©ias e a difusĂŁo mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rĂĄpido balanço crĂtico da historiografia brasileira sobre o tema
Les défis du pluralisme en éducation : essais sur la formation interculturelle /
Bibliogr.: p. 163-17
Stochastic decomposition method for detection of epithelium dysplasia and inflammation using white light spectroscopy imaging
Proceedings of the 28th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS'06, pp. 1956-1959.In this paper, we present a stochastic
decomposition method (SDM) that allows the detection of
dysplasia in epithelial tissue using white-light spectroscopy
imaging. The main goal is to extract the data from the
decomposition which will lead to the construction of a feature
parameter space corresponding to changes in the tissue
morphology related to formation of dysplasia and
inflammation. These parameters include the number and mean
energy of coherent scatterers; deviation from Rayleigh
scattering; residual error variance of the diffuse component;
and normalized correlation coefficient. The tests are performed
on tissue-mimicking phantom data and tissue data collected
from mouse colon in vitro. The obtained results demonstrate
effectiveness of the method in differentiating between tissue
structures with different cell morphologies. The results are
shown by fusing all the estimated parameter set together and
also using each parameter separately. Combination of all the
features results in an Az value higher than 0.927 for the
phantom data. For the tissue data, the best performances for
differentiation between pairs of various levels of inflammation
are 0.859, 0.983, and 0.999
Fingerprint Alignment Based on Local Feature Combined with Affine Geometric Invariant
In this paper we introduce a novel method of fingerprint alignment that uses the intrinsic geometric properties of
minutiae-based triangles combined with the geometric invariant. The minutiae points are extracted from the
fingerprint image and a Delaunay (DL) triangulation is constructed from these minutiae points resulting in a
series of triangles. Corresponding minutiae points are established using local affine invariants constructed from
the local minutia-based triangles. Triangles that are distorted by noise or have no counter part on the query are
discarded. We rely only on âstrongâ matches that are reliable and present, for example, where the error metric
between the local absolute invariants is below a set threshold. The correspondences of such matches are then
used to estimate transformation parameters. The performance of our method is represented by computing the
distance map error between a template and a query fingerprint after undoing the transformation, computed from
the ridge structures of the two fingerprints. In conclusion, the proposed method can be used to find the
corresponding minutiae and align any fingerprints considered into affine transformation, in the presence of noise
including the partial occlusion
Classification of the stages of hyperplasia in breast ducts by analyzing different depths and segmentation of ultrasound breast scans into ductal areas
Proceedings of the 28th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS'06, pp. 2396-2399.In this paper, we study in depth the potential of
detection of epithelium hyperplastic growth in the breast ducts
leading to early breast cancer detection. Towards that end, we
use a stochastic decomposition algorithm of the RF echo into its
coherent and diffuse components that yields image parameters
related to the structural parameters of the hyperplastic stages
of the breast tissue. Previously, we proved that the two
parameters, in particular the number of coherent scatterers
and the Rayleigh scattering degree show very high ability to
discriminate between various stages of hyperplasia even in
cases of low resolution and low SNR values. In this paper, the
discrimination power of the other parameters is studied further
considering different depths using a point scatterer model
simulator that mimics epithelium hyperplastic growth in the
breast ducts. Significant improvement is obtained in the
performance with the newly adopted method considering
depth. Values of Az up to 0.974 are obtained when
discriminating between pairs of stages using the parameter
residual error variance. In addition, this paper presents a fast
nonparametric segmentation procedure to locate the ducts
illustrated using phantom data. The performance of the
segmentation procedure is obtained as Az>0.948 for various
regions of breast scans
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