Lumbar puncture. Lumbar puncture (LP), also known as a spinal tap, is a medical procedure in which a needle is inserted into the spinal canal, most commonly to collect cerebrospinal fluid (CSF) for diagnostic testing. The main reason for a lumbar puncture is to help diagnose diseases of the central nervous system, including the brain and spine.
2. ratio-the relation between things (or parts of things) with respect to their comparative quantity, magnitude, or degree; an inordinate proportion of the book is given over to quotations; a dry martini has a large proportion of gin. proportion.
Information Ratio. A ratio of portfolio returns in excess of the returns of a benchmark (usually an index) to the volatility of those returns. Similar to Sharpe Ratio. The information ratio (IR) measures a portfolio manager's ability to generate excess returns relative to a benchmark, but also attempts to identify the consistency of the portfolio manager.