Langerhans' cell histiocytosis can manifest as three distinct clinicopathologic entities: acute disseminated Langerhans' histiocytosis (previously known as Letterer-Siwe disease), unifocal Langerhans' cell histiocytosis (previously known as eosinophilic granuloma).
average handle time (AHT) Average handle time (AHT) is a call center metric for the average duration of one transaction, typically measured from the customer's initiation of the call and including any hold time, talk time and related tasks that follow the transaction. AHT is a prime factor when deciding call center staffing levels.
A time-weighted average is used to calculate a workers daily exposure to a hazardous substance (such as chemicals, dusts, fumes, mists, gases, or vapors) or agent (such as occupational noise), averaged to an 8-hour workday, taking into account the average levels of the substance or agent and the time spent in the area.