1,845 research outputs found

    Machine learning approach for segmenting glands in colon histology images using local intensity and texture features

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    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

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    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: dN/dMMβdN/dM\propto M^{\beta} with β1.9\beta \approx-1.9 and dN/dττγdN/d\tau\propto\tau^{\gamma} with γ0.8\gamma\approx -0.8. 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, ϵβϵγ\epsilon_{\beta}\sim\epsilon_{\gamma}\sim~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

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    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

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    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.&nbsp
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