Rooted quivers are quivers that do not contain A∞ ≡ ··· → • → • as a subquiver. The existence of flat covers and cotorsion envelopes for representations of these quivers have been studied by Enochs et al. The main goal of this paper is to prove that flat covers and cotorsion envelopes exist for representations of A∞. We first characterize finitely generated projective representations of A∞. We ...

7 An antimatroid is a family of sets such that it contains an empty set, and it is accessible and closed under union of sets. An antimatroid is an ‘antipodal’ concept of matroid. 9 We shall show that an antimatroid is derived from shelling of a poset if and only if it does not contain a minor isomorphic to S7 where S7 is the smallest semimodular lattice that is not 11 modular. It is also shown ...

Aim: To evaluate the effect of bi-jaw premolar extractions on Bolton tooth size discrepancy in patients of Indian origin, all of which exhibited a bilateral Angle’s class I molar relationship. Materials and methods: Ninety sets of pretreatment study casts, which constituted the sample for the study, were divided into three groups, namely, Bolton small (BS), Bolton normal (BN), and Bolton big (B...

Introduction: Historically, countless compounds in aqueous solution have been suggested as root canal irrigants. MTAD shows promise as an endodontic irrigant but there are very few studies comparing its antimicrobial effectiveness with NaOCl and Chlorhexidine. Objectives: To compare the antibacterial efficiency of MTAD, 2.5% Sodium Hypochlorite and 2% Chlorhexidine root canal irrigants against ...

PURPOSE Clinical, radiological and histological evaluation of root perforations treated with mineral trioxide aggregate (MTA) or Portland cements, and calcium sulfate barrier. METHODS One molar and 11 premolar teeth of a male mongrel dog received endodontic treatment and furcations were perforated with a high-speed round bur and treated with a calcium sulfate barrier. MTA, Portland cement typ...