Tata Institute of Fundamental Research

About: Tata Institute of Fundamental Research is a education organization based out in Mumbai, Maharashtra, India. It is known for research contribution in the topics: Magnetization & Large Hadron Collider. The organization has 7786 authors who have published 21742 publications receiving 622368 citations. The organization is also known as: TIFR.

Oral mucosal lesions associated with betel quid, areca nut and tobacco chewing habits: consensus from a workshop held in Kuala Lumpur, Malaysia, November 25-27, 1996.

Abstract: A variety of betel/areca nut/tobacco habits have been reviewed and categorized because of their possible causal association with oral cancer and various oral precancerous lesions and conditions, and on account of their widespread occurrence in different parts of the world. At a recent workshop in Kuala Lumpur it was recommended that "quid" be defined as "a substance, or mixture of substances, placed in the mouth or chewed and remaining in contact with the mucosa, usually containing one or both of the two basic ingredients, tobacco and/or areca nut, in raw or any manufactured or processed form." Clear delineations on contents of the quid (areca nut quid, tobacco quid, and tobacco and areca nut quid) are recommended as absolute criteria with finer subdivisions to be added if necessary. The betel quid refers to any quid wrapped in betel leaf and is therefore a specific variety of quid. The workshop proposed that quid-related lesions should be categorized conceptually into two categories: first, those that are diffusely outlined and second, those localized at the site where a quid is regularly placed. Additional or expanded criteria and guidelines were proposed to define, describe or identify lesions such as chewer's mucosa, areca nut chewer's lesion, oral submucous fibrosis and other quid-related lesions. A new clinical entity, betel-quid lichenoid lesion, was also proposed to describe an oral lichen planus-like lesion associated with the betel quid habit.

Unusual Dispersion and Line Shape of the Superconducting State Spectra of Bi2Sr2CaCu2O8+δ

Abstract: Photoemission spectra of ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+\ensuremath{\delta}}$ below ${T}_{c}$ show two features near the $(\ensuremath{\pi},0)$ point of the zone: a sharp peak at low energy and a higher binding energy hump. We find that the sharp peak persists at low energy even as one moves towards $(0,0)$, while the broad hump shows significant dispersion which correlates well with the normal state dispersion. We argue that these features are naturally explained by the interaction of electrons with a sharp mode which appears only below ${T}_{c}$, and speculate that the latter may be related to the resonance seen in recent neutron data.

Fast K-dimensional tree algorithms for nearest neighbor search with application to vector quantization encoding

Abstract: Fast search algorithms are proposed and studied for vector quantization encoding using the K-dimensional (K-d) tree structure. Here, the emphasis is on the optimal design of the K-d tree for efficient nearest neighbor search in multidimensional space under a bucket-Voronoi intersection search framework. Efficient optimization criteria and procedures are proposed for designing the K-d tree, for the case when the test data distribution is available (as in vector quantization application in the form of training data) as well as for the case when the test data distribution is not available and only the Voronoi intersection information is to be used. The criteria and bucket-Voronoi intersection search procedure are studied in the context of vector quantization encoding of speech waveform. They are empirically observed to achieve constant search complexity for O(log N) tree depths and are found to be more efficient in reducing the search complexity. A geometric interpretation is given for the maximum product criterion, explaining reasons for its inefficiency with respect to the optimization criteria. >

Sirt1 and mir-9 expression is regulated during glucose-stimulated insulin secretion in pancreatic β-islets

Abstract: MicroRNA mir-9 is speculated to be involved in insulin secretion because of its ability to regulate exocytosis. Sirt1 is an NAD-dependent protein deacetylase and a critical factor in the modulation of cellular responses to altered metabolic flux. It has also been shown recently to control insulin secretion from pancreatic β-islets. However, little is known about the regulation of Sirt1 and mir-9 levels in pancreatic β-cells, particularly during glucose-dependent insulin secretion. In this article, we report that mir-9 and Sirt1 protein levels are actively regulated in vivo in β-islets during glucose-dependent insulin secretion. Our data also demonstrates that mir-9 targets and regulates Sirt1 expression in insulin-secreting cells. This targeting is relevant in pancreatic β-islets, where we show a reduction in Sirt1 protein levels when mir-9 expression is high during glucose-dependent insulin secretion. This functional interplay between insulin secretion, mir-9 and Sirt1 expression could be relevant in diabetes. It also highlights the crosstalk between an NAD-dependent protein deacetylase and microRNA in pancreatic β-cells.