Facial rejuvenation Facial rejuvenation Facial rejuvenation is a cosmetic treatment (or series of cosmetic treatments), which aims to restore a youthful appearance to the human face. Facial rejuvenation can be achieved through either surgical and/or non-surgical options. Procedures can vary in invasiveness and depth of treatment. Surgical procedures can restore facial symmetry through targeted procedures and facial restructuring and skin alterations. Non-surgical procedures can target specific depths of facial structures and treat localized facial concerns such as wrinkles, skin laxity, hyperpigmentation and scars. Surgical (invasive) facial rejuvenation procedures can include a brow lift (forehead lift), eye lift (blepharoplasty), facelift (rhytidectomy), chin lift
Birth–death process population size by 1. Birth–death process The birth–death process is a special case of continuous-time Markov process where the state transitions are of only two types: "births", which increase the state variable by one and "deaths", which decrease the state by one. The model's name comes from a common application, the use of such models to represent the current size of a population where the transitions are literal births and deaths. Birth–death processes have many applications in demography, queueing theory, performance engineering, epidemiology and biology. They may be used, for example to study the evolution of bacteria, the number of