Where does infiltration collide?

In soil hydrology, infiltration is the entry of water from the surface into the soil, and the infiltration capacity is the maximum rate at which a given soil can take that water in, declining as the soil wets up until any rainfall beyond it becomes surface runoff. Horton's 1933 The role of infiltration in the hydrologic cycle made this rate the pivot of the water balance, separating what soaks in from what runs off. The referent is a flux of water across the soil surface, measured in the field with ring infiltrometers, and it has nothing to do with immune cells entering a tumour or an informant slipping into a movement, beyond the shared image of something passing into a body.[1]

Unit

The rate at which water enters the soil surface, in depth per time

Recovery means

Infiltration capacity recovers as the soil drains and dries between storms

Measured by

Measured with ring infiltrometers and rainfall-runoff records, and modelled by curves of rate against time

In political sociology, infiltration is the covert entry of an outsider, an informant or agent provocateur, into a social movement or organisation in order to watch, report on, or disrupt it from within, so that a participant is secretly working for an opposing party. Gary Marx's 1974 Thoughts on a neglected category of social movement participant: The agent provocateur and the informant analysed how such planted participants operate and how they distort the movements they penetrate. The referent is the clandestine penetration of a group by a hidden adversary, studied through cases and records of surveillance, and it is a wholly different thing from water soaking into soil or lymphocytes invading a tumour.[2]

Unit

The covert presence of an outside agent inside a target group

Recovery means

Not applicable

Measured by

Documented from exposed cases, court and agency records, and accounts of surveillance operations

In immunology and oncology, infiltration is the movement and accumulation of immune cells into a tissue, and the density, type, and location of lymphocytes infiltrating a tumour turn out to predict how a patient will fare. Galon and colleagues' 2006 Type, density, and location of immune cells within human colorectal tumors predict clinical outcome showed that this immune infiltrate forecasts survival better than the standard staging of the cancer itself. The referent is the invasion of a tissue by populations of immune cells, quantified by staining and counting cells in sections, and it shares only the word with water entering soil or an agent entering a movement.[3]

Unit

The type, density, and location of immune cells within a tissue

Recovery means

Not applicable

Measured by

Quantified by immunohistochemistry and cell counting in tissue sections, summarised in scores such as the immune context