1,845 research outputs found
Machine learning approach for segmenting glands in colon histology images using local intensity and texture features
Colon Cancer is one of the most common types of cancer. The treatment is
planned to depend on the grade or stage of cancer. One of the preconditions for
grading of colon cancer is to segment the glandular structures of tissues.
Manual segmentation method is very time-consuming, and it leads to life risk
for the patients. The principal objective of this project is to assist the
pathologist to accurate detection of colon cancer. In this paper, the authors
have proposed an algorithm for an automatic segmentation of glands in colon
histology using local intensity and texture features. Here the dataset images
are cropped into patches with different window sizes and taken the intensity of
those patches, and also calculated texture-based features. Random forest
classifier has been used to classify this patch into different labels. A
multilevel random forest technique in a hierarchical way is proposed. This
solution is fast, accurate and it is very much applicable in a clinical setup
Similarities in Populations of Star Clusters
We compare the observed mass functions and age distributions of star clusters
in six well-studied galaxies: the Milky Way, Magellanic Clouds, M83, M51, and
Antennae. In combination, these distributions span wide ranges of mass and age:
10^2\lea M/M_{\odot}\lea10^6 and 10^6\lea\tau/yr \lea10^9. We confirm that
the distributions are well represented by power laws:
with and with . The mass and age distributions are approximately independent of each
other, ruling out simple models of mass-dependent disruption. As expected,
there are minor differences among the exponents, at a level close to the true
uncertainties, ~0.1--0.2. However,
the overwhelming impression is the similarity of the mass functions and age
distributions of clusters in these different galaxies, including giant and
dwarf, quiescent and interacting galaxies. This is an important empirical
result, justifying terms such as "universal" or "quasi-universal." We provide a
partial theoretical explanation for these observations in terms of physical
processes operating during the formation and disruption of the clusters,
including star formation and feedback, subsequent stellar mass loss, and tidal
interactions with passing molecular clouds. A full explanation will require
additional information about the molecular clumps and star clusters in galaxies
beyond the Milky Way.Comment: 20 pages, 4 figures, 2 tables; published in the Astrophysical
Journal, 752:96 (2012 June 20
The Age Distribution of Massive Star Clusters in the Antennae Galaxies
We determine the age distribution of star clusters in the Antennae galaxies
(NGC 4038/9) for two mass-limited samples (M > 3 x 10^4 M_{\odot} and M > 2 x
10^5 M_{\odot}). This is based on integrated broadband UBVI and narrowband
H-alpha photometry from deep images taken with the Hubble Space Telescope. We
find that the age distribution of the clusters declines steeply, approximately
as dN/d\tau \propto \tau^{-1}. The median age of the clusters is ~10^7 yr,
which we interpret as evidence for rapid disruption ("infant mortality"). It is
very likely that most of the young clusters are not gravitationally bound and
were disrupted near the times they formed by the energy and momentum input from
young stars to the interstellar matter of the protoclusters. At least 20% and
possibly all stars form in clusters and/or associations, including those that
are unbound and short-lived.Comment: 11 pages, 2 figures. To appear in the ApJ Letters; Submitted 2004
July 29; accepted 2005 August
Silencing Dissent: Law and English Language
The English language since its introduction to the Indian subcontinent has garnered a significant position wherein it got appropriated as the language of all official and momentous proceedings of the state and otherwise. However not unlike the functioning of the social institutions whose mode of dictate it has evolved into becoming, the English language has itself been reduced to becoming the handmaiden of those in power and dictating from a stance of privilege. The legal system that was envisioned to help liberate the masses from oppressive regimes and systems of manipulation, like other such institutions has succumbed to the linguistic paradigm of this language which itself finds genesis in a patriarchal system. Thus, this paper through the mode of Vijay Tendulkar’s path breaking play, Silence! The Court is in Session aims to highlight the persistent futility of the legal system through its use of the English language in meeting out justice to its female subjects. 
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