Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Surgical Management and Scheimpflug Analysis of an Atypical Lens Coloboma

A lens coloboma is not a true coloboma; it is just a zonular absence that causes a defect in the lens equator and hence a more spherical lens. It can be isolated or in association with iris, choroid or retinal colobomas. Typically the defect is present at the site of the embryonic fissure, but it can be present elsewhere. This congenital defect can cause amblyopia, especially when it is associated with cataract. We describe a case of a 39-year-old male with an atypical coloboma that was managed successfully with phacoemulsification, capsular tension ring and intraocular lens implantation. Scheimpflug image analysis and full ophthalmological assessment were performed. Scheimpflug images demonstrated a notching of the lens equator and an absence of zonulae. During the surgical procedure an ophthalmic viscosurgical device was used to tamponade the vitreous, and after continuous curvilinear capsulorhexis the capsular tension ring was inserted to allow the surgeon to perform a safe phacoemulsification