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.
A loss ratio is a ratio of losses to gains, used normally in a financial context. It is the opposite of the gross profit ratio (commonly known as the gross profit margin). For insurance, the loss ratio is the ratio of total losses incurred (paid and reserved) in claims plus adjustment expenses divided by the total premiums earned.